JP5771502B2 - Valve timing change device - Google Patents

Description

  The present invention relates to a valve timing changing device that changes an opening / closing timing (valve timing) of an intake valve or an exhaust valve of an internal combustion engine in accordance with an operation state.

As a conventional valve timing changing device, a housing rotor (housing) that rotates in synchronization with a crankshaft, a rotation rotor that synchronizes with a camshaft, and that is housed in a housing rotor, the housing chamber is made into a retard chamber and an advance angle. The vane rotor which can be divided into two chambers and can rotate relative to the housing rotor at a predetermined operating angle (angle range between the most advanced angle position and the most retarded angle position), and the vane rotor is housed when the engine is stopped and started Lock mechanism (lock pin, spring, etc.) that locks the rotor at an intermediate position between the most retarded angle position and the most advanced angle position and that is unlocked by hydraulic pressure, operation for the advance angle chamber and the retard angle chamber Provided with a hydraulic control valve that controls the supply and discharge of oil or a hydraulic control valve that controls the supply and discharge of hydraulic oil to the lock mechanism, etc. And turning control, that locks the intermediate position so as to ensure the startability is known at the time of engine start (for example, see Patent Document 1).
In this device, since the lock pin of the lock mechanism reciprocates in a direction parallel to the rotation axis of the camshaft, centrifugal force that affects the lock operation or the unlocking operation acts on the lock pin. However, since the lock mechanism (lock pin) is accommodated in the vane portion of the vane rotor, the vane portion must be formed large, and there is a problem that the operating angle can be set only within a limited range.

In addition, as another valve timing changing device, similarly to the above, a housing rotor (housing member), a vane rotor (rotor member), a lock mechanism that locks the vane rotor with respect to the housing rotor, and hydraulic oil to and from the lock mechanism are supplied and discharged. Locking member that has a hydraulic circuit, etc., and locks as a locking mechanism that can be fitted in the receiving portion of the vane rotor by projecting in the radial direction in a plane perpendicular to the rotation axis of the camshaft. In order to cancel the centrifugal force by generating a counter force in a direction opposite to the centrifugal force generated in the lock member of the lock mechanism, the spring is energized in the direction and moved in the radial direction. A counter member, which is housed in a housing rotor and supported so as to be swingable. Which was adopted abutting shaft member are known printer member (e.g., see Patent Document 2).
In this device, although the centrifugal force generated in the lock member can be canceled, a dedicated cancel mechanism is required, so the structure is complicated, and a space for disposing the cancel mechanism is required. There is a problem that the size of the apparatus is increased.

JP 2009-257261 A Japanese Patent No. 4062224

  The present invention has been made in view of the above circumstances, and its object is to achieve the most retarded position and the most advanced angle while simplifying the structure, reducing the size of the apparatus, and reducing the cost. The operating angle between the position and the position can be set larger than before, the effect of centrifugal force in the locking mechanism is prevented, and the locking and unlocking operations by the locking mechanism are ensured. It is an object of the present invention to provide a valve timing changing device that can prevent a hitting sound, wear, and the like and can ensure a stable startability of an engine.

The valve timing changing device of the present invention includes a housing rotor that rotates on the rotation axis of the camshaft in conjunction with the rotation of the crankshaft, and a housing that accommodates the housing rotor so as to be relatively rotatable in a predetermined angle range. The chamber is divided into an advance chamber and a retard chamber, and a vane rotor that rotates integrally with the camshaft, an advance passage that communicates with the advance chamber and allows hydraulic oil to pass therethrough, and communicates hydraulic fluid with the retard chamber. An intake valve or exhaust that is opened and closed by a camshaft, and includes a retarding passage through which the vane rotor is locked at a predetermined position within a predetermined angle range with respect to the housing rotor and unlocked by hydraulic oil pressure. A bubble timing changing device for changing the opening / closing timing of a valve, wherein the lock mechanism swings in a predetermined plane in a vertical plane perpendicular to a rotation axis. A lock bar supported by the housing rotor to swing around the center, and a biasing spring that biases the lock bar toward the lock position of the vane rotor. The lock bar has a center of gravity in the entire swing range. The configuration is such that the centrifugal force is generated in the direction in which the locked state is maintained.
According to this configuration, the lock mechanism that locks the vane rotor (camshaft) at a predetermined position within a predetermined angle range with respect to the housing rotor includes the lock bar that swings in a vertical plane perpendicular to the rotation axis of the camshaft and the lock bar. Because it includes an urging spring, if a thick vane containing a lock pin is held in an intermediate position at the time of start in the storage chamber as in the prior art, phase adjustment from the start position to the advance angle direction is possible. Although the control angle cannot be secured, the present invention does not require an extra thickness for the vane, so the phase adjustment angle between the most advanced angle position and the most retarded angle position can be set widely, and is therefore necessary. A wide range of phase control can be performed according to the above.
In particular, the lock bar is positioned so that the center of gravity of the lock bar generates a centrifugal force in the direction in which the lock state is maintained in the entire swing range, so that the centrifugal force generated by the rotation acts to maintain the lock state. On the other hand, by applying the hydraulic pressure of the hydraulic oil, the locked state by the lock bar is released, and the expected function can be surely performed by the lock mechanism.

In the above-described configuration, the lock bar has a center region whose center of gravity is displaced from the center of the swing in the radial direction passing through the rotation axis and is deviated by a predetermined amount from the straight line connecting the rotation axis and the swing center. The structure currently formed so that it may be located in can be employ | adopted.
According to this configuration, the center of gravity of the lock bar is positioned in the above-described range, so that the rotation torque due to the centrifugal force does not act on the lock bar or the torque that rotates in the locking direction even if it acts. Therefore, the lock bar can be reliably maintained at the locked position.

In the above configuration, the housing rotor is separated from the receiving chamber and has a separating wall that defines a separating chamber in which the locking mechanism is disposed, and the housing rotor cooperates with the separating wall to define the separating chamber. The lock mechanism includes a lock cam coupled to rotate integrally with the vane rotor through a through hole provided in the isolation wall, and the lock bar is engaged with the lock cam. A configuration in which the vane rotor is locked and is released from the lock cam to unlock the vane rotor can be adopted.
According to this configuration, since the isolation chamber in which the lock mechanism is disposed is defined by the isolation wall of the housing member and the cover member that is detachable with respect to the housing member, the vane rotor is incorporated in the housing chamber of the housing member, The lock mechanism can be easily assembled or removed, and when the engine is started (cranking), the lock bar locks the lock cam so that the vane rotor is positioned at a predetermined position relative to the housing rotor (intermediate). After the engine is started, the lock by the lock bar can be released by the hydraulic pressure.
That is, by reliably maintaining the vane rotor at a predetermined position (intermediate position) by the lock mechanism, the engine can be started more reliably, and since the lock mechanism does not directly lock the vane rotor, the vane portion of the vane rotor is thinned. This increases the degree of freedom in design and layout.

In the above-described configuration, the lock bar is formed in a substantially L-shaped flat plate shape, and a supported portion that passes the support shaft provided in the housing rotor in the bent region, and extends in one direction from the supported portion, and the lock cam An engagement-side arm that can be engaged with the support, and a pressure-receiving-side arm that extends in the other direction from the supported part and receives the pressure of the hydraulic oil, and the center of gravity of the lock bar is positioned in the vicinity of the supported part. The configuration can be adopted.
According to this configuration, the supported portion of the lock bar is swingably supported by the support shaft, and the engagement side arm portion engages with the lock cam to lock the vane rotor, while the pressure receiving side arm portion The lock of the vane rotor is released when the hydraulic pressure of the hydraulic oil acts and the engagement side arm portion is detached from the lock cam.
Here, since the center of gravity of the lock bar is positioned near the supported part, that is, near the support shaft, the distance from the swing center (center of the support shaft) to the center of gravity can be set small, and the rotational torque can be increased by centrifugal force. Therefore, the influence of centrifugal force on the operation of the lock bar can be minimized.

In the above configuration, the lock bar includes an advance lock bar that restricts the vane rotor from rotating to the advance side, and a retard lock bar that restricts the vane rotor from rotating to the retard side. A configuration including an advance angle regulating spring that urges the advance angle lock bar to engage and lock the lock cam, and a retard angle restriction spring that urges the angle lock bar to engage and lock the lock cam. Can be adopted.
According to this configuration, the advance angle lock bar is urged by the advance angle regulating spring and the lock cam (that is, the vane rotor) is shifted from the predetermined position (intermediate position) to the advance angle side in a state where the hydraulic oil pressure does not act. The retarding lock bar is urged by a retarding regulation spring to restrict the lock cam (that is, the vane rotor) from shifting from the predetermined position (intermediate position) to the retarding side, so that the vane rotor is moved to the predetermined position (intermediate position). The vane rotor can be positioned reliably, and even if it deviates from the predetermined position (intermediate position) when the engine is stopped, the vane rotor is moved to the predetermined position by the fluctuation torque during cranking and the biasing force of the advance angle regulating spring and the retard angle regulating spring. It can be returned to (intermediate position).

In the above configuration, the advance passage is formed so as to guide the hydraulic pressure of the hydraulic oil so as to release the lock of the advance lock bar and the retard lock bar, and the retard passage is formed of the hydraulic oil guided through the advance passage. It is possible to adopt a configuration in which the hydraulic pressure of the hydraulic oil is guided so as to maintain the unlocking of only the retard lock bar after the lock is released by the hydraulic pressure.
According to this configuration, even if the hydraulic oil pressure is led through the retard passage, the retard lock bar is not unlocked unless the hydraulic oil pressure is led through the advance passage. The phase of the vane rotor with respect to the housing rotor can be held at a predetermined position (intermediate position) until this device is in a controllable state, and thus stable startability of the engine can be ensured.

In the above configuration, the retard passage defines an opening that opens in the direction of the rotation axis, and the pressure-receiving side arm of the retard lock bar has an opening portion of the retard passage by a main surface that faces in the direction of the rotation axis. The structure which is formed so as to open and close can be adopted.
According to this configuration, the retard passage can be opened and closed only by the rocking motion of the lock bar, so that the number of parts can be reduced and the structure can be simplified.

  According to the valve timing changing device configured as described above, the operating angle between the most retarded angle position and the most advanced angle position is compared with the conventional one while achieving simplification of the structure, downsizing of the device, cost reduction, and the like. The locking mechanism can prevent the influence of centrifugal force and guarantee the locking and unlocking operations of the locking mechanism. Stable startability can be ensured.

It is a disassembled perspective view which shows the valve timing change apparatus which concerns on this invention. It is sectional drawing which shows the valve timing change apparatus which concerns on this invention. It is sectional drawing which shows the valve timing change apparatus which concerns on this invention. It is sectional drawing which shows the advance passage (advance chamber passage) which the vane rotor which makes a part of valve timing change apparatus communicates with an advance chamber in the state in a predetermined position (intermediate position). It is sectional drawing which shows the retard angle channel | path (retard angle chamber channel | path) which the vane rotor which makes a part of valve timing change apparatus communicates with a retard angle chamber in the state which exists in a predetermined position (intermediate position). It is sectional drawing which shows the state which the lock mechanism (lock cam, lock lever) which makes a part of bubble timing change apparatus locked the vane rotor to the predetermined position (intermediate position). It is sectional drawing which shows the state which the lock mechanism (lock cam, lock lever) which makes a part of bubble timing change apparatus was cancelled | released, and the vane rotor moved to the advance side. It is sectional drawing which shows the state which the lock mechanism (lock cam, lock lever) which comprises a part of bubble timing change apparatus was cancelled | released, and the vane rotor moved to the retard side. FIG. 2 shows a part of the lock mechanism (advance angle lock bar and advance angle regulating spring), (a) is a partial view showing the locked state, and (b) is a partial view showing the unlocked state. FIG. 2 shows a part of the lock mechanism (retard angle lock bar and retard angle regulating spring), (a) is a partial view showing the locked state, and (b) is a partial view showing the unlocked state. FIG. 2 shows a part of the lock mechanism (advance angle lock bar and advance angle regulating spring), (a) is a partial view showing the state of hydraulic oil at the lock position, and (b) is an operation at the lock release position. It is a fragmentary figure which shows the state of oil. FIG. 2 shows a part of the lock mechanism (retarding lock bar and retarding regulating spring), (a) is a partial view showing the state of hydraulic oil at the locked position, and (b) is operated at the unlocked position. It is a fragmentary figure which shows the state of oil. It is sectional drawing which shows the state in which the vane rotor which makes a part of valve timing change apparatus exists in a predetermined position (intermediate position). It is sectional drawing which shows the state which has the vane rotor which makes a part of valve timing change apparatus in a most advanced position. It is sectional drawing which shows the state which has the vane rotor which makes a part of valve timing change apparatus in the most retarded position.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
As shown in FIGS. 1 to 3, the valve timing changing device rotates on the rotation axis S1 of the camshaft 10 and the vane rotor 20 that can be detachably fixed to the camshaft 10, and can relatively rotate the vane rotor 20. Housing rotor 30 which is accommodated in the vane rotor 20 and defines the advance angle chamber 30a and the retard angle chamber 30b, and the vane rotor 20 is locked to a predetermined position (intermediate position) with respect to the housing rotor 30. Lock mechanism 40 (lock cam 41, advance lock bar 42, advance angle restricting spring 43, retard angle lock bar 44, retard angle restricting spring 45) disposed in the isolation chamber, and center bolt 50 for fastening the vane rotor 20 to the camshaft 10. The lock cam 41 included in the lock mechanism 40 is returned to a predetermined position (intermediate position). Assist mechanism 60 to strike, and a hydraulic control system OCS for controlling the flow of hydraulic oil (lubricating oil).
The camshaft 10 opens and closes an intake valve or an exhaust valve of the engine by a cam action, and the housing rotor 30 is interlocked with the rotation of the crankshaft via a chain or the like, and the rotation driving force of the crankshaft is increased. The power is transmitted to the camshaft 10 via the vane rotor 20.

  As shown in FIGS. 1 to 3, the camshaft 10 can be rotated around the rotation axis S1 by a bearing B (see FIG. 2) formed on a cylinder head (not shown) of the engine (in the direction of arrow CR in FIG. 1). The hydraulic oil is supplied to and discharged from the journal portion 11 supported by the bearing B, the cylindrical portion 12 that rotatably supports the housing rotor 30, the advance chamber 30a, and the advance lock bar 42. Are provided with the advance passage 13, the retard chamber 30b, the retard passage 14 for supplying and discharging the hydraulic oil to and from the retard lock bar 44, the female screw portion 15 for fastening the center bolt 50, and the like.

  As shown in FIGS. 1 to 5, the vane rotor 20 is formed in a hub portion 22 that integrally holds four vane portions 21 and four vane portions 21 at equal intervals, and a center bolt 50 is passed through the vane rotor 20. For supplying and discharging hydraulic oil to and from the advance chamber passage 24 and the retard chamber 30b formed by branching from the advance passage 13 for supplying and discharging hydraulic oil to and from the through hole 23 and the advance chamber 30a. A retard chamber passage 25 formed by branching from the retard passage 14, a seal member 26 fitted in a groove formed at the tip of the vane portion 21, and the like, and a cam using a center bolt 50 together with the lock cam 41 It is fastened to the shaft 10 and rotates integrally with the camshaft 10.

  The housing rotor 30 is rotatably supported on the rotation axis S1 of the camshaft 10 in conjunction with the rotation of the crankshaft, and is coupled to the housing member 31 and the back side of the housing member 31 as shown in FIGS. And a cover member 33 coupled to the front side of the housing member 31, and the vane rotor 20 is relatively moved within a predetermined angle range (angle range between the most advanced angle position and the most retarded angle position). The lock mechanism 40 is accommodated (defining an isolation chamber) and the vane rotor 20 (the vane portion 21) is accommodated in the advance chamber 30a and the retard chamber 30b. It is formed to be bisected.

  As shown in FIG. 1 to FIG. 5 and FIG. 13, the housing member 31 has a cylindrical wall 31a, an isolation wall 31b, a through hole 31c provided in the center of the isolation wall 31b, and toward the center on the back side of the isolation wall 31b. Four projecting bearing portions 31d, a recess 31e that is defined between and at the center of each bearing portion 31d and accommodates the vane rotor 20, a recess 31f that is formed on the front side of the isolation wall 31b and accommodates the lock mechanism, and an advance angle Both of the lock bar passages 31g formed by branching from the advance passage 13 to supply and discharge hydraulic oil to and from the lock bar 42 and the retard lock bar 44, and supply and discharge of hydraulic oil to the retard lock bar 44. Therefore, a retarding lock bar passage 31h formed by branching from the retarding passage 14, an opening 31h ', support shafts 31i, 31j, receiving portions 31k, 31k', stopper wall 31o, 31p, and a recess 31q for accommodating the assist mechanism 60 are provided.

As shown in FIGS. 6 to 8, both the lock bar passages 31g open to the recess 31f and guide the hydraulic pressure to the side surfaces of the advance angle lock bar 42 and the retard angle lock bar 44 (the pressure receiving side arm portion). The hydraulic pressure acts in a direction to release the locked state.
As shown in FIGS. 6 to 8, the retard lock bar passage 31h opens into the recess 31f and guides hydraulic pressure to the main surface of the retard lock bar 44 (a plane toward the rotation axis S1). When the retard lock bar 44 rotates (moves) in a direction to release the locked state by a predetermined angle by the hydraulic pressure guided from the bar passage 31g, the hydraulic pressure is released from the closed state by the main surface of the retard lock bar 44. To the side surface of the retard lock bar 44 (the pressure receiving side arm portion), and so that the hydraulic pressure acts in a direction to release the locked state (that is, a concave long groove shape formed by cutting the surface of the concave portion 31f). It is formed so as to be connected to the opening 31h ′.

  As shown in FIGS. 1 to 3, the sprocket member 32 is rotatably fitted to a sprocket 32 a around which a chain for transmitting the rotational driving force of the crankshaft is wound and the cylindrical portion 12 of the camshaft 10. The peripheral surface 32b, the front surface 32c in which the back surface of the vane rotor 20 is slidably contacted, and formed to branch from the advance passage 13 for supplying and discharging hydraulic oil to and from the advance lock bar 42 and the retard lock bar 44. Both the lock bar passages 32d, the retard lock bar passage 32e formed by branching from the retard passage 14 for supplying and discharging the hydraulic oil to and from the retard lock bar 44 are provided.

As shown in FIGS. 13 to 15, both the lock bar passages 32 d are defined by an arcuate passage extending in the circumferential direction and a passage extending in the radial direction, and the vane rotor 20 has the most advanced angle position and the slowest position. The advance passage 13 and both lock bar passages 31g are formed to communicate with each other during the relative rotation between the corner positions.
As shown in FIGS. 13 to 15, the retard lock bar passage 32e is defined by an arcuate passage extending in the circumferential direction and a passage extending in the radial direction. During the relative rotation between the retard position and the retard position, the retard passage 14 and the retard lock bar passage 31h are communicated with each other.

  As described above, the advance passage 13 is formed by branching into both the lock bar passages 31g and 32d and the advance chamber passage 24, and the retard passage 14 is retarded with the retard lock bar passages 31h and 32e. Since it is branched to the corner chamber passage 25, the responsiveness at the time of unlocking is good, and the lock mechanism 40 operates smoothly without being affected by the hydraulic oil in the advance chamber 30a and the retard chamber 30b. Can be made. Further, since both the lock bar passages 31g and 32d and the retarded angle lock bar passages 31h and 32e are defined by the housing member 31 and the sprocket member 32, the camshaft 10, the sprocket member 32, and the housing member 31 are separated from each other. Thus, both the lock bar passages 31g and 32e and the retard lock bar passages 31h and 32e can be easily formed by performing simple drilling and groove processing, respectively.

As shown in FIGS. 1 to 3, the cover member 33 has a circular hole 33 a through which the center bolt 50 passes, and is formed to be detachable from the housing member 31.
The housing member 31, the sprocket member 32, and the cover member 33 are fastened using bolts or the like.
Further, the cover member 33 is coupled to the housing member 31 so that an isolation chamber in which the lock mechanism 40 is disposed is defined.

  As shown in FIGS. 1 and 6 to 8, the lock mechanism 40 includes a lock cam 41, an advance lock bar 42, an advance restriction spring 43, a retard lock bar 44, and a retard restriction spring 45. The vane rotor 20 is formed so as to be locked at a predetermined position (intermediate position) within a predetermined angle range (between the most advanced angle position and the most retarded angle position) that can rotate relative to the housing rotor 30. Yes.

  The lock cam 41 is fastened to the camshaft 10 together with the vane rotor 20 by the center bolt 50 so that the predetermined angle range is rotated, and the advance lock bar 42 and the retard lock bar 44 can be detachably engaged. Is formed.

As shown in FIGS. 9 (a) and 9 (b), the advance lock bar 42 is formed in a substantially L-shaped flat plate shape, and is provided on the housing member 31 in the bent region so as to swing as a swing center. The supported portion 42a through which the support shaft 31i that defines the movement axis S2 passes, the engagement side arm portion 42b that extends from the supported portion 42a in one direction and engages with the lock cam 41, and extends from the supported portion 42a in the other direction. The pressure receiving side arm portion 42c that receives the pressure of the hydraulic oil is provided.
The advance angle lock bar 42 is swingably supported by the support shaft 31i in a vertical plane perpendicular to the rotation axis S1, and one end portion of the advance angle regulating spring 43 is brought into contact with the engagement side arm portion 42b. In this state, the counterclockwise rotation is urged so as to contact the stopper wall 31o, and the counterclockwise rotation is controlled by contacting the stopper wall 31o, thereby contacting the lock cam 41 (that is, the vane rotor 20). 11 is restricted from rotating from the rest position to the advance side, while the hydraulic pressure of the hydraulic oil supplied through both lock bar passages 31g (32d) is received as shown in FIGS. 11 (a) and 11 (b). By acting on the side surface 42c ′ of the compression side arm portion 42c, it is rotated clockwise to release the lock.

Here, as shown in FIGS. 9A and 9B, the advance angle lock bar 42 has its center of gravity G1 positioned in the vicinity of the supported portion 42a, that is, in the radial direction passing through the rotation axis S1. Within the range of a region deviated by a predetermined amount in the rotational direction (counterclockwise in FIGS. 9A and 9B) that is locked from the inner side of the moving axis S2 and on the straight line L1 connecting the rotating axis S1 and the swinging axis S2. It is formed so that it may be located in.
That is, the center of gravity G1 is positioned so as to generate a centrifugal force in a direction in which the locked state is maintained over the entire swing range.
Here, assuming that the clockwise rotational torque due to the hydraulic pressure of the hydraulic oil is T1, the counterclockwise rotational torque due to the biasing force of the advance angle regulating spring 43 is T2, and the counterclockwise rotational torque due to the centrifugal force is T3, then T1> It is set to be T2 + T3.
In particular, since the center of gravity G1 of the advance lock bar 42 is positioned in the vicinity of the supported portion 42a, that is, in the vicinity of the support shaft 31i (swing axis S2), the center of gravity G1 from the swing axis S2 (center of the support shaft 31i). Can be set small, and the rotational torque T3 due to the centrifugal force can be reduced. Therefore, the influence of the centrifugal force on the operation of the advance lock bar 42 can be minimized.
Therefore, the centrifugal force generated by the rotation of the housing rotor 30 acts to maintain the locked state by the advance lock bar 42 and can be prevented from being released arbitrarily. By applying the hydraulic pressure of the hydraulic oil supplied through 31g (32d), the lock state by the advance lock bar 42 is released, and the lock mechanism can reliably perform the intended function.

As shown in FIGS. 6 to 8, the advance angle regulating spring 43 has one end abutting on the receiving portion 31 k of the housing member 31 and the other end on a part of the engagement side arm portion 42 b of the advance lock bar 42. The advancing lock bar 42 is held in a compressed state by contact and is urged to rotate counterclockwise so that the advance lock bar 42 is engaged with the lock cam 41 and locked.
Here, the biasing force of the advance angle regulating spring 43 is set so that a smooth releasing operation is performed when the hydraulic pressure of the hydraulic oil acts to release the locked state of the advance angle lock bar 42.

As shown in FIGS. 10 (a) and 10 (b), the retard lock bar 44 is formed in a substantially L-shaped flat plate shape, and is provided on the housing member 31 in the bent region so as to swing as a swing center. The supported portion 44a through which the support shaft 31j that defines the movement axis S3 is passed, the engagement side arm portion 44b that extends in one direction from the supported portion 44a and can be engaged with the lock cam 41, and extends in the other direction from the supported portion 44a. Thus, a pressure receiving side arm portion 44c for receiving the pressure of the hydraulic oil is provided.
The retard lock bar 44 is swingably supported by the support shaft 31j in a vertical plane perpendicular to the rotation axis S1, and one end of the retard regulating spring 45 is brought into contact with the engagement side arm 44b. In this state, the lock cam 41 (that is, the vane rotor 20) is stopped while being in contact with the lock cam 41 in a state in which the rotation is urged clockwise so as to contact the stopper wall 31p. On the other hand, the hydraulic oil pressure of the hydraulic oil supplied through the lock bar passages 31g (32d) is controlled by the side surface of the pressure receiving side arm portion 44c as shown in FIG. By acting on 44c ', it is rotated counterclockwise to release the lock, and when it is rotated by a predetermined angle as shown in FIG. 10 (b), the retard lock bar passage 31h (opening 31h') is opened. Even if the hydraulic pressure of the hydraulic oil supplied from both the lock bar passages 31g (32d) does not act by being opened, the operation supplied through the retard lock bar passages 31h (opening 31h ') and 32e. As shown in FIGS. 8 and 12 (b), the hydraulic pressure of the oil only acts on the side surface 44c ″ of the pressure receiving side arm portion 44c, so that the unlocked state is maintained.

Here, as shown in FIGS. 10A and 10B, the retard lock bar 44 has its center of gravity G2 positioned in the vicinity of the supported portion 44a, that is, in the radial direction passing through the rotation axis S1. Within a range of a region deviated by a predetermined amount in the rotational direction (clockwise in FIGS. 10A and 10B) that locks from the inner side of the moving axis S3 and on the straight line L2 connecting the rotating axis S1 and the swinging axis S3. It is formed to be located.
That is, the center of gravity G2 is positioned so as to generate a centrifugal force in a direction in which the locked state is maintained in the entire swing range.
Here, assuming that the counterclockwise rotational torque due to the hydraulic pressure of the hydraulic oil is T1 ′, the clockwise rotational torque due to the urging force of the retard restriction spring 45 is T2 ′, and the clockwise rotational torque due to the centrifugal force is T3 ′, T1 ′> T2 ′ + T3 ′ is set.
In particular, since the center of gravity G2 of the retard lock bar 44 is positioned in the vicinity of the supported portion 44a, that is, in the vicinity of the support shaft 31j (swing axis S3), the center of gravity G2 from the swing axis S3 (center of the support shaft 31j). Can be set small, the rotational torque T3 ′ due to the centrifugal force can be reduced, and therefore the influence of the centrifugal force on the operation of the retard lock bar 44 can be minimized.
Therefore, the centrifugal force generated by the rotation of the housing rotor 30 acts to maintain the locked state by the retarded angle lock bar 44 and can be prevented from being released arbitrarily. The locking state by the retard lock bar 44 is released by applying the hydraulic pressure of the hydraulic oil supplied through 31g (32d) and the hydraulic pressure of the hydraulic oil supplied through the retard lock bar passage 31h (opening 31h '). Thus, the lock mechanism can reliably perform its intended function.
Further, the pressure receiving side arm portion 44b of the retard lock bar 44 is formed so as to open and close the opening 31h ′ of the retard lock bar passage 31h by the main surface facing in the direction of the rotation axis S1. Since the retard lock bar passage 31h (retard passage) can be opened and closed only by the swinging operation of the retard lock bar 44, the number of parts can be reduced and the structure can be simplified. it can.

As shown in FIGS. 6 to 8, the retard angle regulating spring 45 has one end abutting against the receiving portion 31 k ′ of the housing member 31, and the other end being a part of the engagement side arm portion 44 b of the retard lock bar 44. The retard lock bar 44 is rotated and biased clockwise to engage and lock the lock cam 41.
Here, the urging force of the retard restriction spring 45 is set so that a smooth release operation is performed when the hydraulic pressure of the hydraulic oil acts to release the locked state of the retard lock bar 44.

  According to the lock mechanism 40 having the above-described configuration, the lock cam 41 and the vane rotor 20 are locked at the predetermined position (intermediate position) by being locked by the advance lock bar 42 and the retard lock bar 44 in the state shown in FIGS. In the state shown in FIGS. 7 and 14, the locks by the advance lock bar 42 and the retard lock bar 44 are both released and rotate clockwise so that one vane portion 21 contacts one bearing portion 31d. In this state, only the lock by the retard lock bar 44 is released and the vane portion 21 rotates counterclockwise in the state shown in FIGS. 8 and 15 and one bearing portion 31d. Is positioned at the most retarded angle position.

As shown in FIGS. 1 to 3, the center bolt 50 has a solid cylindrical shape, and includes a male screw portion 51 on the tip side.
The center bolt 50 is passed through the through hole 23 of the vane rotor 20 so as to define a predetermined annular gap, and the male screw portion 51 is screwed into the female screw portion 15 of the camshaft 10. Thus, the lock cam 41 and the vane rotor 20 are integrally fastened to the camshaft 10.

  As shown in FIGS. 6 to 8, the assist mechanism 60 includes a push member 61 and an urging spring 62 arranged in the recess 31q of the housing member 31, and the lock cam 41 (vane rotor 20 and camshaft 10) is the latest. It is formed so as to exert an assisting force to move from the corner position side to the intermediate position.

  2 and 3, the hydraulic control system OCS includes a hydraulic control valve 100 that is fitted and fixed to a cylinder head CH and the like, a pump 70 that supplies hydraulic oil to the hydraulic control valve 100, and a pump. A supply passage 71 for passing the discharged hydraulic oil, a drain passage 72 for passing the hydraulic oil discharged from the hydraulic control valve 100, an advance passage 73 for connecting the hydraulic control valve 100 and the advance passage 13 to pass the hydraulic oil, The hydraulic control valve 100 and the retarding passage 14 are connected to each other, and a retarding passage 74 through which hydraulic oil passes, control means (not shown) for controlling the driving of the hydraulic control valve 100, and the like.

Next, the operation of the valve timing changing device will be described with reference to FIGS. 2 and 3, FIGS. 6 to 8, and FIGS. 13 to 15.
When the engine is stopped by the driver's intention, the hydraulic control valve 100 performs drive control so as to discharge the hydraulic oil in the advance chamber 30a and the retard chamber 30b for a predetermined time after the ignition switch is turned off. The drain mode is selected, the hydraulic fluid in the advance chamber 30a is discharged through the advance passage 73 → the drain passage 72, and the hydraulic oil in the retard chamber 30b is discharged through the retard passage 74 → the drain passage 72. Is done.

As shown in FIG. 6, since the hydraulic oil is discharged from both the lock bar passages 31g, 32d and the retard lock bar passages 31h, 32e, the hydraulic pressure does not act. ) And the urging force of the advance angle restricting spring 43 and the retard angle restricting spring 45, the lock cam 41 is positioned at an intermediate position as a predetermined position and is locked by the advance angle lock bar 42 and the retard angle lock bar 44. The vane rotor 20 is positioned at an intermediate position between the most advanced angle position and the most retarded angle position, as shown in FIG. This intermediate position is set to a valve timing at which a smooth start can be performed when the engine starts (cranking). When the engine is stopped due to engine stall or the like against the driver's intention, the control means determines that, and the same drain mode as described above is applied for a predetermined time in the same manner as when the ignition switch is turned off. Selected.
When the energization for a predetermined time is finished, the hydraulic control valve 100 is maintained in a state in which the hydraulic oil in the advance chamber 30a is discharged and the operation is shifted to the retard mode in which the hydraulic oil can be supplied to the retard chamber 30b. The

  Thus, the vane rotor with respect to the housing rotor 30 is driven by driving the hydraulic control valve 100 so as to be in the drain mode for a predetermined time after the ignition switch is turned off to stop the engine or after the engine is stopped by the engine stall. The position of 20 can be reliably positioned at a predetermined intermediate position that is optimal for engine start, and the next engine start can be smoothly performed.

  At the time of starting the engine, the vane rotor 20 (lock cam 41) is already locked at the intermediate position, and the hydraulic control valve 100 is in the retard mode. When the vane rotor 20 (the lock cam 41) is not shifted and locked from the intermediate position, the retard lock bar 44 and the advance lock bar 42 are moved toward the lock side by the retard control spring 45 and the advance control spring 43, respectively. And is always urged to rotate, and is automatically moved to an intermediate position and locked by a fluctuating torque generated by cranking.

Therefore, when the engine is cranked for starting, the hydraulic oil in the advance chamber 30a is discharged through the advance passage 73 → the drain passage 72, and the pump 70 → the supply passage 71 → the retard passage. After 74, the hydraulic oil is supplied to the retarding chamber 30b.
The hydraulic oil in both lock bar passages 31g is discharged through the advance passage 73 → the drain passage 72, and the retard lock bar passage 31h (opening 31h ') is as shown in FIG. In addition, since the main surface of the retard lock bar 44 is closed, the hydraulic pressure of the hydraulic oil does not act in the direction of releasing the lock of the retard lock bar 44, and the advance lock bar 42 and the retard lock bar 44 are In both cases, the lock cam 41 (vane rotor 20) is locked at the intermediate position.

  In other words, since the hydraulic control valve 100 is in the state in which the lock mechanism 40 is locked, the retard angle mode is selected. Therefore, even when the drive source does not operate due to disconnection or the like, Can prevent abnormal wear, damage to parts, etc. of the sliding portion in the mechanism including the housing rotor 30, the vane rotor 20, etc., the lock mechanism 40, and other mechanisms, and the vane rotor 20 can be at an intermediate position. Since the rotation is urged to the retard side by the hydraulic pressure of the hydraulic oil, the fluttering can be prevented. Further, since the vane rotor 20 (camshaft 10) is positioned at the intermediate position, the engine can be started smoothly.

When the engine starts, the hydraulic control valve 100 is switched as appropriate, and the vane rotor 20 (camshaft 10) moves from the intermediate position to the advance side (advance angle mode) or the retard angle side (retard angle mode), and further to a predetermined level. Phase control is performed so as to be held at the angular position (holding mode).
For example, when the phase is changed to the advance side, the hydraulic control valve 100 is switched to select the advance mode in which the hydraulic oil in the retard chamber 30b is discharged and the hydraulic oil is supplied to the advance chamber 30a. .
In this advance angle mode, hydraulic oil is supplied to the advance angle chamber 30a through the pump 70 → the supply passage 71 → the advance angle passage 73, and as shown in FIG. 7, the advance is made through both lock bar passages 31g and 32d. The hydraulic oil pressure is supplied to the angle lock bar 42 and the delay angle lock bar 44 to release the lock, and when the angle delay lock bar 44 rotates by a predetermined angle, the delay angle lock bar passage 31h is opened. The hydraulic pressure maintains the retard lock bar 44 in the unlocked state. On the other hand, hydraulic oil is discharged from the retard chamber 30b through the retard passage 74 → the drain passage 72. Thereby, as shown in FIG. 14, the phase can be changed by moving the vane rotor 20 to the advance side.

Further, when the vane rotor 20 is held at a predetermined phase angle between a predetermined most advanced angle position and a most retarded angle position, the hydraulic control valve 100 is switched to the advanced angle chamber 30a and the retarded angle chamber 30b. A holding mode (pump mode) for supplying hydraulic oil is selected.
In this holding mode, the hydraulic oil is supplied to the advance chamber 30a via the pump 70 → the supply passage 71 → the advance passage 73, and the hydraulic oil is supplied to the retard chamber 30b via the pump 70 → the supply passage 71 → the retard passage 74. The hydraulic oil pressure is supplied to the advance lock bar 42 and the retard lock bar 44 through both the lock bar passages 31g and 32d, and the lock is released. At the time of rotation, the retard lock bar passage 31h is opened and the hydraulic pressure maintains the retard lock bar 44 in the unlocked state. That is, the vane rotor 20 can be held at a predetermined intermediate phase by the hydraulic pressure acting on the advance chamber 30a and the retard chamber 30b.

On the other hand, when the phase is changed to the retarded angle side, the hydraulic control valve 100 is once switched from the intermediate position at the start to the advance angle mode or the holding mode (pump mode), and then the hydraulic oil is supplied to the retard chamber 30b. In addition, the retard angle mode for discharging the hydraulic oil in the advance chamber 30a is selected.
In this retard angle mode, as shown in FIG. 8, the lock by the retard lock bar 44 is released and maintained by the hydraulic pressure that has been actuated once in the advanced angle mode or the holding mode (pump mode). In this state, the hydraulic oil in the advance chamber 30a is discharged through the advance passage 73 → the drain passage 72, and is supplied to the retard chamber 30b through the pump 70 → the supply passage 71 → the retard passage 74. Is done. Thereby, as shown in FIG. 15, the phase can be changed by moving the vane rotor 20 to the retard side.

As described above, since the lock of the retard lock bar 44 is not released unless the hydraulic oil pressure is guided through the advance passage 13 (both lock bar passages 31g and 32d), until the complete explosion occurs at the start of the engine. The phase of the vane rotor 20 with respect to the housing rotor 30 can be maintained at an intermediate position, and thus stable startability of the engine can be ensured.
Further, since the retard mode is selected while the lock mechanism 40 is kept locked when the engine is started, the hydraulic fluid is supplied by cranking at the time of starting the engine, so that the housing rotor 30, the vane rotor 20, etc. Can prevent abnormal wear of the sliding portion, locking mechanism 40, other mechanisms, etc., breakage of parts, and the like, and the vane rotor 20 can be urged to rotate toward the retarded side. Occurrence can be prevented.
Further, since the advance lock bar 42 and the retard lock bar 44 are positioned so as to generate centrifugal force in the direction in which the center of gravity G1, G2 maintains the locked state in the entire swing range, the advance lock bar 42 and the retard lock bar 44 are generated by rotation. The centrifugal force acts to maintain the locked state and can prevent the locked state from being released arbitrarily by the centrifugal force. On the other hand, the hydraulic oil pressure is applied to release the locked state by the lock bar. Thus, the lock mechanism can reliably perform its intended function.

In the above embodiment, the housing rotor 30 including the sprocket 32a for transmitting the rotational force of the crankshaft has been shown. However, the present invention is not limited to this, and means for transmitting the rotational driving force of the crankshaft has other structures. (For example, a toothed timing belt), a housing rotor having a structure (toothed pulley, etc.) suitable for the structure can be employed.
In the above embodiment, the case where the lock cam 41, the advance lock bar 42, the advance restriction spring 43, the retard lock bar 44, and the retard restriction spring 45 are employed as the lock mechanism is shown, but the present invention is not limited to this. Other lock mechanisms may be employed as long as they have a lock bar that can be rocked in a vertical plane perpendicular to the rotation axis S1 and locked at a predetermined position (intermediate position).
In the above embodiment, the support shafts 31i and 31j protruding from the housing member 31 are used to support the advance angle lock bar 42 and the retard angle lock bar 44 so as to be swingable. However, the present invention is not limited to this. A configuration may be adopted in which a bearing hole is provided in the housing member, and a support shaft that is fitted into the bearing hole with respect to the advance lock bar and the retard lock bar is provided.
In the above embodiment, the case where the pump mode in which hydraulic oil is supplied to the advance chamber 30a and the retard chamber 30b is employed in the holding mode is shown, but the present invention is not limited to this. A closed mode in which the flow of hydraulic oil to the 30a and the retard chamber 30b is blocked may be employed.

  As described above, the valve timing changing device of the present invention achieves the operating angle between the most retarded angle position and the most advanced angle position while achieving simplification of the structure, miniaturization of the apparatus, cost reduction, and the like. It can be set larger than the conventional one, prevents the influence of centrifugal force in the lock mechanism, guarantees locking and unlocking operation by the lock mechanism, and prevents fluttering of the vane rotor, hammering sound and wear in the lock mechanism, etc. Since stable startability of the engine can be ensured, it can be applied to an internal combustion engine mounted on an automobile or the like, and is also useful for a small engine mounted on a motorcycle or the like.

S1 Rotating axis 10 Camshaft 11 Journal portion 12 Cylindrical portion 13 Advance passage 14 Delay passage 15 Female thread portion 20 Vane rotor 21 Vane portion 22 Hub portion 23 Through hole 24 Advance chamber passage (advance passage)
25 Retarded room passage (retarded passage)
26 Seal member 30 Housing rotor 30a Advance angle chamber 30b Delay angle chamber 31 Housing member (housing rotor)
31a Cylindrical wall 31b Separating wall 31c Through hole 31d Bearing portions 31e, 31f, 31q Recessed portion 31g Passage for both lock bars (advanced passage)
31h Retarded lock bar passage (retarded passage)
31h 'opening 31i, 31j support shaft 31k, 31k' receiving part 31o, 31p stopper wall 32 sprocket member (housing rotor)
32a Sprocket 32b Inner peripheral surface 32c Front surface 32d Passage for both lock bars
32e Passage for retarding lock bar (retarding passage)
33 Cover member (housing rotor)
40 Lock mechanism 41 Lock cam 42 Advance angle lock bar S2 Oscillation axis (Oscillation center)
L1 straight line G1 center of gravity 42a supported portion 42b engagement side arm portion 42c pressure receiving side arm portion 42c 'side surface 43 advance angle regulating spring 44 retard angle lock bar S3 swing axis (swing center)
L2 straight line G2 center of gravity 44a supported part 44b engagement side arm part 44c pressure receiving side arm part 44c ', 44c''side face 45 retard angle regulating spring 50 center bolt 51 male thread part 60 assist mechanism 61 push member 62 biasing spring 70 pump 71 Supply passage 72 Drain passage 73 Advance passage 74 Delay passage 100 Hydraulic control valve

Claims (7)

A housing rotor that rotates on the rotation axis of the camshaft in conjunction with the rotation of the crankshaft, and a housing chamber that accommodates the housing rotor so as to be relatively rotatable in a predetermined angular range, and the housing chamber is made to advance and retard. A vane rotor that bisects into a corner chamber and rotates integrally with the camshaft; an advance passage that communicates with the advance chamber and passes hydraulic fluid; and a retard passage that communicates with the retard chamber and passes hydraulic fluid A lock mechanism that locks the vane rotor at a predetermined position within the predetermined angle range with respect to the housing rotor and that is unlocked by hydraulic pressure of hydraulic oil, and is configured to be an intake valve or an exhaust valve that is opened and closed by a camshaft. A bubble timing changing device for changing the opening and closing timing,
The lock mechanism includes a lock bar supported by the housing rotor so as to swing around a predetermined swing center in a vertical plane perpendicular to the rotation axis, and the lock bar facing the lock position of the vane rotor. Including a biasing spring
The lock bar is positioned so that its center of gravity generates a centrifugal force in a direction in which the lock state is maintained in the entire swing range.
A valve timing changing device characterized by that. The lock bar has an area whose center of gravity is deviated by a predetermined amount in a rotation direction that locks from a straight line that connects the rotation axis and the rocking center inside the rocking center in a radial direction passing through the rotation axis. Formed to be within range,
The valve timing changing device according to claim 1. The housing rotor includes a housing member having an isolation wall that is separated from the receiving chamber and defines an isolation chamber in which the locking mechanism is disposed, and the housing member cooperates with the isolation wall to define the isolation chamber. Including a cover member detachably formed with respect to the
The lock mechanism includes a lock cam coupled to rotate integrally with the vane rotor through a through hole provided in the isolation wall;
The lock bar is formed to engage the lock cam to lock the vane rotor, and to disengage from the lock cam to unlock the vane rotor.
The valve timing changing device according to claim 1 or 2, wherein The lock bar is formed in a substantially L-shaped flat plate shape, a supported portion that passes a support shaft provided in the housing rotor in a bent region thereof, and extends in one direction from the supported portion, and the lock cam An engagement side arm that can be engaged with, and a pressure receiving side arm that extends in the other direction from the supported portion and receives the pressure of hydraulic oil,
The center of gravity of the lock bar is positioned in the vicinity of the supported portion,
The valve timing changing device according to claim 3, wherein: The lock bar includes an advance angle lock bar that restricts the vane rotor from rotating toward the advance angle side, and a retard angle lock bar that restricts the vane rotor from rotating toward the retard angle side,
The urging spring includes an advance angle regulating spring that urges the advance angle lock bar to engage and lock the lock cam, and an engagement angle spring that engages and locks the retard angle lock bar to the lock cam. Including a retarding angle regulating spring
The valve timing changing device according to claim 3 or 4, wherein The advance passage is formed to guide hydraulic pressure of hydraulic oil to unlock the advance lock bar and the retard lock bar;
The retard passage is configured to guide the hydraulic pressure of the hydraulic oil so that the lock of only the retard lock bar is maintained after the lock is released by the hydraulic pressure of the hydraulic oil guided through the advance passage. Yes,
The valve timing changing device according to claim 5, wherein The retard passage defines an opening that opens in the direction of the axis of rotation;
The pressure receiving side arm portion of the retard lock bar is formed to open and close the opening portion of the retard passage by a main surface facing in the direction of the rotation axis.
The valve timing changing device according to claim 6.

Images