JP4950949B2 - Valve timing control device for internal combustion engine - Google Patents

Description

  The present invention relates to a valve timing control device for an internal combustion engine that variably controls the opening / closing timing of an engine valve that is an intake valve or an exhaust valve of the internal combustion engine in accordance with an operating state.

  As a conventional valve timing control device for an internal combustion engine, for example, the one described in Patent Document 1 below is known.

  This valve timing control device is a housing that rotates integrally with one side of the crankshaft or camshaft of the engine, and is rotatably accommodated within the housing, and rotates integrally with the crankshaft and the other side of the camshaft. The hydraulic pressure is selected for the vane member to be moved, the retarded hydraulic chamber and the advanced hydraulic chamber separated in the housing via the vane extending in the radial direction of the vane member, and the retarded hydraulic chamber and the advanced hydraulic chamber. The hydraulic circuit that changes the relative rotation phase of the housing and the vane member to the retard side or the advance side by supplying and discharging the air and the vane member on the retard side and the advance side of the relative rotation phase. And a lock / release mechanism for locking at an intermediate position.

  A part of the hydraulic circuit is formed along the internal axis direction from the journal portion of the camshaft, and communicates with each of the retard angle and advance angle hydraulic chambers. The lock / release mechanism is supplied and discharged.

  The lock / release mechanism is formed on a lock pin slidably provided inside the vane member and an end wall of the housing, and a bottomed cylindrical tip of the lock pin is engaged or disengaged. The lock pin is biased in the direction of the lock hole by a coil spring, and is released from the lock hole and released from the lock by the hydraulic pressure from the hydraulic circuit.

  When the engine is stopped, no hydraulic pressure is supplied to the hydraulic chambers or the pressure receiving chambers of the lock / release mechanism, and the lock pin is engaged in the lock hole by the spring force of the coil spring, so that the vane member is intermediate to the housing. The phase position is locked and this state is maintained even when the engine is started.

After that, when the engine is shifted to a steady operation, the lock pin is released from the lock hole by releasing and supplying the hydraulic pressure from the hydraulic circuit to each hydraulic chamber and supplying the hydraulic pressure to the pressure receiving chamber, and the locked state is released. The member rotates forward and backward with respect to the housing to convert the relative rotational phase to the advance side or the retard side.
JP 2003-262108 A

  In the conventional valve timing control device, since the lock hole for engaging and disengaging the tip end portion of the lock pin is formed in a circular shape, the position of the lock pin is locked due to a manufacturing error or an assembly error. If the lock pin is displaced in the radial direction, the relative rotation phase between the vane member and the housing may be displaced from a desired intermediate position when the lock pin is engaged with the lock hole.

The present invention has been devised in view of the technical problem of the conventional apparatus, and the invention according to claim 1 is directed to a drive rotator to which a rotational force is transmitted from a crankshaft of an engine, and the drive rotator. A driven rotator that transmits a rotational force from the camshaft, a phase changing mechanism that rotates the driven rotator relative to the drive rotator within a predetermined rotation angle range, and the drive rotator and the driven rotator. A first lock pin and a second lock pin which are provided on either side and are urged so as to protrude from the rotation axis direction toward the other rotation body; and provided on the other of the drive rotation body and the driven rotation body, by the distal end portion of the first locking pin and second locking pin is engaged entrance, first holding the relative rotational position of the drive rotor and the driven rotor between the most retarded position and the most advanced position 1 and the lock hole and a second locking hole, the first Tip of the lock pin, with which is formed into a bottomed cylindrical shape, smaller is than the area of the outer diameter of the bottom portion of the first lock hole, wherein when holding the relative rotational phase of the phase changing mechanism The first inner wall surface of the first lock hole capable of contacting the first lock pin is formed in a planar shape extending in the radial direction.

  According to the present invention, since the inner wall surface of the lock hole is formed in a flat shape along the radial direction, for example, when the engine is stopped, the lock pin is moved into the lock hole by the biasing force of the biasing member. When trying to engage, it always contacts the outer peripheral edge of the lock pin by line contact. Therefore, even if the lock pin is displaced in the radial direction due to a manufacturing error or an assembly error, it is possible to suppress the relative rotational phase shift between the vane member and the housing.

  Hereinafter, an embodiment in which a valve timing control device for an internal combustion engine according to the present invention is applied to an intake side will be described with reference to the drawings.

  1 to 3 show an embodiment of the present invention, and a sprocket 1 that is a driving rotating body that is rotationally driven by a crankshaft of an engine via a timing chain, and the sprocket arranged along the longitudinal direction of the engine. A camshaft 2 on the intake side provided so as to be relatively rotatable with respect to 1 and a phase conversion mechanism 3 disposed between the sprocket 1 and the camshaft 2 to convert the relative rotation phase between the two. And a first hydraulic circuit 4 that operates the phase conversion mechanism 3.

  The sprocket 1 has a substantially thick disk-shaped main body 5 and a gear portion 6 that is integrally provided at one end of the outer periphery of the main body 5 and around which the timing chain is wound. The main body 5 is configured as a rear cover that closes a rear end opening of the housing, which will be described later, and has a through hole 5a formed at a predetermined position in the circumferential direction of the outer peripheral portion, and rotates to the outer periphery of the end portion of the camshaft 2 A support hole 5b that is freely supported is formed through.

  The camshaft 2 is rotatably supported by a cylinder head (not shown) via a cam bearing, and a plurality of cams for opening an intake valve, which is an engine valve, are integrally fixed to an axial position on the outer peripheral surface. In addition, a female screw hole 2a is formed in the inner axial direction of one end.

  As shown in FIGS. 1 and 3, the phase conversion mechanism 3 includes a housing 7 provided integrally with the sprocket 1 and a cam bolt 8 that is screwed into a female screw hole 2 a at one end of the camshaft 2. A vane member 9 which is a driven rotating body fixed and rotatably accommodated in the housing 7, and three partition walls 10 formed on the inner peripheral surface of the housing 7 and vanes formed in the housing 7. Three retarded hydraulic chambers 11 and advanced hydraulic chambers 12 separated by the member 9 are provided.

  The housing 7 includes a cylindrical housing body, a front cover 13 that closes a front end opening of the housing body, and the sprocket body 5 as a rear cover that closes a rear end opening. The sprocket body 5 is fixed together by three bolts 14 penetrating the partition wall 10. The front cover 13 is integrally provided with a cylindrical portion 13a on a central outer surface.

  The vane member 9 is integrally formed of a metal material as shown in FIGS. 1 and 3, and the vane rotor 15 is fixed to one end portion of the camshaft 2 by a cam bolt 8. The vane member 9 is circumferentially disposed on the outer peripheral surface of the vane rotor 15. And three vanes 16 projecting radially at approximately 120 ° equidistant positions.

  The vane rotor 15 is formed in a substantially cylindrical shape, and a thin cylindrical step portion 15a having a small step is provided at a substantially central position of the front end surface 15b. The outer surface of the support portion 15a and the front end surface 15b Thus, the front cover 13 is rotatably supported. On the other hand, each of the vanes 16 is disposed between the partition walls 10, and a seal member 17 is provided on the outer peripheral surface for sealing between the inner surface of the housing body.

  Further, the retard hydraulic chambers 11 and the advance hydraulic chambers 12 described above are defined between both side surfaces of the vanes 16 in the forward / reverse rotation direction and both side surfaces of the partition walls 13, respectively. The retarded hydraulic chamber 11 and each advanced hydraulic chamber 12 are in communication with each other through the first communicating hole 11a and the second communicating hole 12a formed substantially radially inside the vane rotor 15, respectively.

  The first hydraulic circuit 4 selectively supplies or discharges hydraulic pressure to or from each of the retard angle and advance angle hydraulic chambers 11 and 12, and as shown in FIG. A retard oil passage 18 that is a second passage for supplying and discharging hydraulic pressure via the first communication passage 11a, and a first oil supply and discharge for each advance angle hydraulic chamber 12 via the second communication passage 12a. An advance oil passage 19 that is a passage, an oil pump 20 that is a fluid pressure supply source that selectively supplies hydraulic oil (hydraulic pressure) to the passages 18 and 19, and the retard oil passage according to the engine operating state. 18 and a first electromagnetic switching valve 21 that is a first control valve for switching the flow path of the advance oil passage 19. The oil pump 20 is a general one such as a trochoid pump that is rotationally driven by an engine crankshaft.

  Each of the retard oil passage 18 and the advance oil passage 19 has one end connected to the first electromagnetic switching valve 21 and the other end inside the vane rotor 15 of the vane member 9 and a support portion 15a. Each of the slow passages is formed through passage portions 18a and 19a formed in parallel in the axial direction in a substantially cylindrical passage constitution portion 37 inserted and held therein and the first and second communication passages 11a and 12a. The angular hydraulic chamber 11 and each advance hydraulic chamber 12 communicate with each other.

  The passage constituting portion 37 is configured as a non-rotating portion with an outer end fixed to a chain cover (not shown), and in addition to the passage portions 18a and 19a, the inner axial direction will be described later. A first supply / discharge passage portion 34a constituting a part of the first supply / discharge passage 34, which is the third passage, is formed.

  As shown in FIG. 1, the first electromagnetic switching valve 21 is a 4-port 3-position proportional valve, and is a spool that is slidable in the axial direction in the valve body by an electronic controller (not shown). The valve body is moved in the front-rear direction so that the discharge passage 20a of the oil pump 20 communicates with one of the oil passages 18 and 19, and at the same time the other oil passage 18 and 19 and the drain passage 22 communicate with each other. It has become. The suction passage and the drain passage 22 of the oil pump 20 communicate with the oil pan 23.

  The controller includes a crank angle sensor (engine speed detection), an air flow meter, a water temperature sensor, a throttle valve opening sensor, and a cam angle sensor that detects the current rotation phase of the camshaft 2. Information signals from various sensors are input to detect the current engine operating state, and a control pulse current is output to each electromagnetic coil of the first electromagnetic switching valve 21 and a second electromagnetic switching valve 36 described later. ing.

  In this embodiment, as shown in FIGS. 1 and 3, a holding mechanism that holds the vane member 9 at the intermediate rotational phase position between the most retarded angle side and the most advanced angle side with respect to the housing 7 is provided. . As shown in FIGS. 6, 14, and 15, the holding mechanism includes first and second lock holes 24 and 25 formed at predetermined positions in the circumferential direction on the inner surface of the sprocket body 5. The first and second lock pins 26 and 27 provided inside the two vanes 16 and 16 of the vane member 9 to be engaged with and disengaged from the lock holes 24 and 25, and the lock pins 26 and 27, respectively. And a second hydraulic circuit 28 that engages or disengages the lock holes 24 and 25.

  As shown in FIGS. 14 and 15, the first lock hole 24 is formed in a rectangular long hole shape with a bottom extending in the circumferential direction of the sprocket body 5, and the vane member on the inner surface of the sprocket body 5. 9 is formed at a position corresponding to a position closer to the advance side than the rotation position on the most retarded angle side, and the circumferential length L is larger than the outer diameter of the distal end portion 26b of the first lock pin 26. The first lock pin 26 formed and engaged with the first lock pin 26 is slightly movable in the circumferential direction of the sprocket body 5.

  Further, as shown in FIG. 14, the first lock hole 24 has inner side surfaces 24 a and 24 b that are inner wall surfaces facing each other in the circumferential direction, and is flat along a straight line extending in the radial direction from the center P of the sprocket body 5. The inner end surfaces facing each other in the radial direction are also formed in a substantially linear plane, and the connecting portions 24c at the four corners between the inner end surfaces and the inner side surfaces 24a and 24b are formed in an arc surface. ing. The bottom surface 24d of the first lock hole 24 is formed in a flat surface shape.

  The second lock hole 25 is formed at a position where the formation position of the second lock hole 25 is closer to the advance side than the most retarded rotation position of the vane member 9, that is, the first lock pin 26 is engaged with the first lock hole 24. The second lock pin 27 is formed at a position where the second lock pin 27 is engaged, and the inner peripheral surface 25a is formed in a tapered surface having a substantially trapezoidal cross section. The second lock hole 25 communicates with the advance oil passage 19 via an oil hole 25b formed in the bottom wall of the groove forming portion and a branch passage 19b.

  The first lock pin 26 is slidably disposed in a first pin hole 16a formed through in the inner axial direction of one vane 16, and has a first large diameter serving as a pressure receiving portion on the outer peripheral surface of the base end portion. The portion 26a is integrally formed, and the outer peripheral surface of the substantially bottomed cylindrical tip portion 26b is formed in a parallel surface parallel to the sliding direction of the first lock pin 26, and the tip surface thereof is the first surface. It is formed in a flat surface shape that can come into close contact with the bottom surface 24 d of the lock hole 24. Further, the first lock pin 26 is provided with a first lock hole 24 by a spring force of a first spring 29 that is an urging means that is elastically mounted between the bottom surface of the groove on the base end side and the inner surface of the front cover 13. It is urged | biased in the direction engaged with.

  The second lock pin 27 is slidably disposed in a second pin hole 16b formed penetrating in the direction of the internal axis of the other vane 16, and has a second large diameter serving as a pressure receiving portion on the outer peripheral surface of the base end portion. The portion 27a is integrally formed, the outer peripheral surface of the tip portion 27b is formed as a conical tapered surface substantially the same shape as the second lock hole 25, and the tip surface is formed flat. . Further, the outer diameter of the distal end portion 27b is formed smaller than the inner diameter of the second lock hole 25 and is engaged in a loosely fitted state, so that the vane member 9 can be rotated slightly. In addition, the second lock pin 27 is provided in the second lock hole 25 by the spring force of the second spring 30 that is an urging means that is elastically mounted between the bottom surface of the groove on the base end side and the inner surface of the front cover 13. It is urged | biased in the direction engaged with.

  As shown in FIGS. 1 and 6, the second hydraulic circuit 28 is formed in a space portion in which the first and second springs 29 and 30 of the first and second pin holes 16 a and 16 b are accommodated. The first pressing pressure receiving chamber 31a and the second pressing pressure receiving chamber 31b that are formed, and the first formed between the step portion of the first pin hole 16a and the first large diameter portion 26a of the first lock pin 26. The pressure receiving chamber 32 for release, the second pressure receiving chamber 33 for release formed between the step portion of the second pin hole 16b and the second large diameter portion 27a of the second lock pin 27, and the first and second push-in The hydraulic pressure is selectively supplied from the oil pump 20 to the pressure receiving chambers 31 a and 31 b and the second release pressure receiving chamber 33 from the branch passage 20 b of the discharge passage 20 a or discharged through the drain passage 22. 2 The first and second passages 34 and 35 and the first and second in accordance with the state of the engine And a second electromagnetic switching valve 36 is a second control valve for switching the exhaust passage 34, 35.

  The first pushing pressure receiving chamber 31 a is formed by the hydraulic pressure supplied from the discharge passage 20 a through the second electromagnetic switching valve 36 through the first oil passage hole 38 a described later and the spring force of the first spring 29. The first lock pin 26 is pushed toward the first lock hole 24 by the combined force. The second pressure receiving chamber 31b for the second push-in is provided with the second lock pin 27 by the combined force of the hydraulic pressure supplied from the discharge passage 20a through the second oil passage hole 38b described later and the spring force of the second spring 30. Is pushed in the direction of the second lock hole 25.

  On the other hand, the first release pressure receiving chamber 32 and the second release pressure receiving chamber 33 are provided with the first and second release pressure receiving chambers 33 by the hydraulic pressure supplied to the retard hydraulic chamber 11 and the advanced hydraulic chamber 12 respectively. The second lock pins 26 and 27 are retracted from the first and second lock holes 24 and 25 against the spring force of the springs 29 and 30 to release the respective engagements.

  Each of the first and second supply / discharge passages 34 and 35 is connected at one end side to a corresponding passage hole of the second electromagnetic switching valve 36, while the first supply / discharge passage portion 34 a on the other end side is connected to the passage. It is formed so as to be substantially parallel to each of the passage portions 18a and 19a in the direction of the internal axis of the component portion 37, and is disposed adjacent to the advance-side passage portion 19a, and the second supply / discharge passage portion 35a. Is formed in parallel with the internal axial direction of one end of the camshaft 2.

  The vane rotor 15 has a first oil passage hole 38a communicating with the first supply / discharge passage portion 34a and the first pressure receiving chamber 31a, and the first supply / discharge passage portion 34a. The second oil passage hole 38b is formed to communicate with the second pushing pressure receiving chamber 31b.

  On the other hand, a third oil passage hole 39 that connects the second supply / discharge passage portion 35a and the second release pressure receiving chamber 33 is formed. The first release pressure receiving chamber 32 is configured to supply and discharge hydraulic pressure supplied to and discharged from the retard hydraulic chamber 11 through an oil hole 40 formed in the vane member 9. .

  Further, a low pressure passage 45 that is a low pressure portion disposed between the advance side passage portion 19a and the first supply / discharge passage portion 34a is formed in the internal axial direction of the passage constituting portion 37. The low-pressure passage 45 has one end opening 45a between the outer peripheral surface of the passage constituting portion 37 and the inner peripheral surface of the support hole 15c of the support portion 15a, that is, on the support hole 15c side of the first supply / discharge passage portion 34a. It is disposed between the opened groove groove 34c and the groove groove 18c opened to the support hole 15c side of the retarded passage portion 18a, and the other end opening is opened to the atmosphere from the outer end portion of the passage constituting portion 37. Has been. The low pressure passage 45 is configured as a flow blocking means.

  Further, a plurality of annular fitting grooves are formed in the axial front and rear positions of the outer peripheral surface of the passage constituting portion 37, and the passage portions 18a and 19a and the first fitting grooves are formed in the fitting grooves. A plurality of seal members 41 for sealing between the open ends of the one supply / discharge passage portion 34a on the support hole 15c side are fitted and fixed.

  The second electromagnetic switching valve 36 is a four-port, three-position proportional valve, and is controlled by a spool valve body by a control current (on-off) output from the electronic controller or a spring force of an internal valve spring. The first and second supply / discharge passages 34 and 35 are connected to the discharge passage 20a and the drain passage 22 selectively as appropriate.

  Further, as shown in FIG. 6, the first lock hole 24 communicates with the advance hydraulic chamber 12 via an introduction hole 42 formed in the vane member 9, and the introduction hole 42 The outer surface of the distal end portion 26b of the first lock pin which is formed in the radial direction with respect to the one lock hole 24 and is engaged by the hydraulic pressure supplied thereto is formed on the inner surface of the first lock hole 24 from the radial direction. It functions as a pressing mechanism for pressing.

  Further, on the outer peripheral side of the support portion 15a of the vane member 9, as shown in FIG. 1, a torsion spring 43 that urges the vane member 9 to rotate in the intermediate phase direction from the retard side is mounted. One end 43 a of the spring 43 is locked in a locking hole formed in the cylindrical portion 13 a of the front cover 13, and the other end 43 b is locked in a circumferential long hole 15 c formed in the vane rotor 15. (See FIG. 3).

  A ring member 44 that holds one end of the torsion spring 43 is fitted and fixed to the inner periphery of the cylindrical portion 13a of the front cover 13 on the opening end side.

  Hereinafter, the operation of the present embodiment will be described with reference to FIGS. 3 to 5 and FIGS.

  First, since the oil pump 20 is not driven when the engine is stopped, the oil pressure chambers 11 and 12, the first lock holes 24, and the pressure receiving chambers 31 to 33 are disposed in the oil pressure chambers 31 to 33, as shown in FIG. Accordingly, the first and second lock pins 26 and 27 have their tip portions 26b and 27b placed in the first and second lock holes 24 and 25 by the spring force of the springs 29 and 30, respectively. Is engaged.

  Further, in this state, the first electromagnetic switching valve 21 is such that the spool valve body is held at the sliding position in the maximum one direction by the spring force of the spring, and the discharge passage 20a and the advance oil passage 19 are communicated with each other. The passage 18 and the drain passage 22 communicate with each other. On the other hand, in the second electromagnetic switching valve 36, the spool valve body is held in the sliding position in the maximum one direction by the spring force of the spring, and the discharge passage 20a and the first supply / discharge passage 34 are communicated with each other. And the drain passage 2 communicate with each other.

  Therefore, when the ignition switch is turned on when the engine is started, as shown in FIG. 7, the oil pump 20 is driven by the first explosion (start of cranking) immediately after that, and the discharge hydraulic pressure is changed to the first supply pressure. The first and second pressure receiving chambers 31a and 31b, the advance hydraulic chamber 12 and the introduction hole 42 are supplied into the first lock hole 24 through the discharge passage 34 and the like. For this reason, the first lock pin 26 and the second lock pin 27 are driven by the combined force of the hydraulic pressure in the first and second push-in pressure receiving chambers 31 a and 31 b and the spring force of the first and second springs 29 and 30. The engagement state is maintained in the first and second lock holes 24 and 25.

  Subsequently, immediately before the cranking is completed and the idling operation is started, as shown in FIG. 8, the control current is output from the electronic controller to the second electromagnetic switching valve 36, and the spool valve body is moved in the other direction. The first supply / discharge passage 34 communicates with the drain passage 22 and the second supply / discharge passage 35 communicates with the discharge passage 20a. For this reason, while the pressure in the first and second pressure receiving chambers 31a and 31b becomes low, the pressure in the second release pressure receiving chamber 33 becomes high, and the hydraulic pressure in the advance hydraulic chamber 19 passes through the branch path 19b. 2 is supplied into the lock hole 25 and becomes a high pressure, whereby the second lock pin 27 is smoothly withdrawn from the second lock hole 25 and the engagement is released.

  On the other hand, the first lock pin 26 has a part of the outer surface of the distal end portion 26b by the hydraulic pressure from the introduction hole 42 in the radial direction (the sprocket body 5) toward one inner side surface 24a of the first lock hole 24 as indicated by an arrow. The first lock hole 24 is firmly engaged and held by the frictional resistance.

  At this time, since the flat end surface of the first lock pin 26 is in close contact with the bottom surface 24d of the first lock hole 24, the hydraulic pressure introduced from the introduction hole 42 causes the first lock pin 26 to Power does not work in the direction to release.

  Further, at the time of starting the engine, as described above, both or one of the lock pins 26, 27 are engaged with the lock holes 24, 25, so that the vane member 9 is as shown in FIG. It is securely held at the intermediate phase position between the most retarded phase and the most advanced angle phase. Therefore, the startability of such an engine is improved.

  Next, in the case of shifting to idling operation, as shown in FIG. 9, the second electromagnetic switching valve 36 remains as it is, but this time, a control current is output from the electronic controller to the first electromagnetic switching valve 21, and the spool valve The body is moved slightly to the other side, the advance oil passage 19 is closed to hold the oil pressure in the advance oil pressure chamber 12, and the discharge passage 20a and the retard oil passage 18 are communicated.

  Therefore, the hydraulic pressure is supplied to the retarded hydraulic chamber 11 and becomes high pressure, and the vane member 9 is slightly rotated to the retarded phase side, whereby the first lock pin 26 is moved in the same direction in the first lock hole 24. And the pressure contact between the outer surface of the tip end portion 26b and the inner surface of the first lock hole 24 is released.

  At the same time, the hydraulic pressure is supplied to the first release pressure receiving chamber 32 through the oil hole 40, and the pressure receiving chamber 32 becomes high pressure, whereby the first lock pin 26 smoothly exits from the first lock hole 24. The engagement is released. For this reason, the vane member 9 can freely rotate in the forward and reverse directions.

  Thereafter, for example, when the engine shifts to a low engine speed and low load range, as shown in FIG. 10, a larger control current is output to the first electromagnetic switching valve 21, and the spool valve body is moved to the advance oil passage 19 and the drain passage. 22, the retarded oil passage 18 and the discharge passage 20a maintain the communication state. As a result, as shown in FIG. 4, the hydraulic pressure in the advance hydraulic chamber 12 is discharged and becomes low pressure, while the retard hydraulic chamber 11 becomes high pressure, and the vane member 9 is moved to the most retarded angle with respect to the housing 7. Rotate to the side. Therefore, the camshaft 2 is converted into the most retarded rotational phase with respect to the sprocket 1.

  As a result, the valve overlap of the intake and exhaust valves is reduced, the residual gas in the cylinder is reduced, the combustion efficiency is improved, the engine rotation is stabilized, and the fuel efficiency is improved.

  Further, for example, when the engine shifts to a high engine speed and high load range, as shown in FIG. 11, the retarded oil passage 18 and the drain passage 22 are communicated with each other by the first electromagnetic switching valve 21, and the retarded hydraulic chamber 11 becomes low pressure. The discharge passage 20a, the advance oil passage 19 and the second lock hole 25 communicate with each other, and the advance hydraulic chamber 12 and the second lock hole 25 become high pressure. For this reason, the second lock pin 27 maintains the retracted position against the spring force of the second spring 30, and the vane member 9 has the most advanced angle with respect to the housing 7, as shown in FIG. Rotate to the side. Thereby, the camshaft 2 is converted into the rotational phase on the most advanced angle side.

  Therefore, the valve overlap is increased, the intake charging efficiency is increased, and the output torque of the engine can be improved.

  As described above, the conversion of the camshaft 2 into the retard angle and advance angle phase can be arbitrarily set according to the engine operating state.

  Further, when the engine is stopped, the vane member 9 is returned to the substantially intermediate rotational position shown in FIG. When the ignition switch is turned off in this state, as shown in FIG. 12, the spool valve body of the first electromagnetic switching valve 21 is moved to the intermediate position at a stage where the rotation of the engine is still slightly before completely stopping. The retard oil passage 18 and the advance oil passage 19 are closed while the second electromagnetic switching valve 36 connects the second supply / discharge passage 35 and the discharge passage 20a.

  Accordingly, the first and second lock pins 26 and 27 are biased in the engagement direction by the combined force of the hydraulic pressure in the first and second pressing pressure receiving chambers 31a and 31b and the first and second springs 29 and 30. Thus, the first lock pin 26 side is engaged with the first lock hole 24, but the second lock pin 27 side is not yet engaged with the second lock hole 25. That is, at this time, the vane member 9 is positioned in a state where it is slightly rotated to the retard side by the alternating torque generated in the camshaft 2 (see FIG. 6). Accordingly, the first lock pin 26 is also engaged with the first lock hole 24 positioned on the retard side, and the second lock pin 27 is not engaged with the second lock hole 25. It has become.

  Thereafter, immediately before the engine is completely stopped, as shown in FIG. 13, the hydraulic pressure is supplied to the advance hydraulic chamber 12 by the first electromagnetic switching valve 21 to increase the pressure, whereby the vane member 9 is The lock pin 26 rotates toward the advance side within the movement range of the first lock hole 24. Therefore, the second lock pin 27 is engaged with the second lock hole 25 by the spring force of the second spring 30 when the tip end portion 27b matches the second lock hole 25, so that the initial movement position (FIG. 6 in the middle position).

  As described above, in the present embodiment, when both the lock pins 26 and 27 are released at the start of the engine, not both at the same time but between the start of cranking and immediately before the idling operation, as described above. Even if the second lock pin 27 is released from the second lock hole 25, the outer surface of the tip 26b of the first lock pin 26 is pressed against the inner surface of the first lock hole 24 from the radial direction (circumferential direction of the sprocket body 5). Then, the engagement state is maintained by the frictional resistance, and then the first lock pin 26 is released when the hydraulic pressure is supplied to the hydraulic chambers 11, 2. It is possible to sufficiently suppress the occurrence of fluttering due to the hydraulic pressure and alternating torque supplied to the hydraulic chambers 11 and 12 at the time of starting. As a result, the generation of abnormal noise can be prevented.

  Further, after the second lock pin 27 is released from the second lock hole 25 by the hydraulic pressure in the second release pressure receiving chamber 33, the first lock pin 26 is released, and until the release, the first lock pin 26 is released. Since the pin 26 is reliably pressed against the first lock hole 24 from the radial direction, the first lock pin 26 is not accidentally released.

  On the other hand, until the engine is completely stopped after the ignition switch is turned off, the first lock pin 26 is first engaged in the first lock hole 24 and then the second lock pin 27 is engaged. Thus, the occurrence of flapping of the vane member 9 due to the alternating torque of the cam can be sufficiently prevented.

  Further, when the engine is restarted, the vane member 9 is held at the intermediate rotational phase position when both the lock pins 26 and 27 are engaged with both the lock holes 24 and 25, so that the startability is improved. .

  Furthermore, in this embodiment, since the outer peripheral surface of the distal end portion 27b of the second lock pin 27 and the inner peripheral surface of the second lock hole 25 are formed as tapered surfaces, the engagement / disengagement with respect to the second lock hole 25 is improved. Become good.

  Further, since the inner side surface 24a of the first lock hole 24 is formed in a flat shape along the radial direction, the first lock pin 26 is biased by the first spring 29 when the engine is stopped. Therefore, when trying to engage with the first lock hole 24, the outer peripheral edge of the front end portion of the first lock pin 26 always comes into contact with one of the lines on the inner side surface 24a by line contact. Therefore, even if the first lock pin 26 is slightly displaced in the radial direction of the vane member 9 due to a manufacturing error or an assembly error, the radial displacement is caused when the first lock pin 26 is engaged with the first lock hole 24. Can be taken in while absorbing.

  In other words, even when the first lock pin 26 is displaced in the radial direction, the outer peripheral edge of the tip portion always abuts along the flat inner side surface 24a in the radial direction. The vane member 9 and the housing 7 do not rotate relative to each other due to the positional shift, and it is possible to suppress the occurrence of a relative rotational phase shift.

  Further, since the connecting portions 24c at the four corners of the first lock hole 24 are formed in an arc shape, even if a relatively large displacement in the radial direction of the first lock pin 26 occurs, the inner side surface 24a side The connecting portions 24c and 24c can absorb the shift.

  Further, in this embodiment, the low pressure released to the atmosphere between each of the retard-side and advance-angle-side passage portions 18a, 19a formed in the passage constituting portion 37 and the first supply / discharge passage portion 34a. Since the passage 45 is formed, if the hydraulic pressure leaks from the groove groove 18c on the support hole 15c side of the retard-side passage portion 18a, the leaked hydraulic pressure is reduced from the one end opening 45a on the support hole 15c side of the low pressure passage 45. It can flow into the passage 45 and be prevented from flowing into the first supply / discharge passage portion 34a.

  Therefore, the supply of hydraulic pressure against the pushing pressure receiving chambers 31a and 31b from the passage portion 18a is suppressed, and the influence of the hydraulic pressure on the lock pins 26 and 27 can be avoided. As a result, it is possible to prevent a locking action due to inadvertent insertion of the lock pins 26 and 27 into the lock holes 24 and 25.

  In addition, the seal member 41 can also block the flow of hydraulic pressure from the groove groove 18c of the passage portion 18a to the groove groove 34c of the first supply / discharge passage portion 34a, so that the hydraulic pressure on the passage portion 18a side with respect to the lock pins 26 and 27 is further increased. It becomes possible to avoid the influence of.

  Moreover, since the leakage of the hydraulic pressure from the passage component 37 to the outside can be sufficiently prevented by the plurality of seal members 41, it is possible to suppress a decrease in the response of the hydraulic pressure to the hydraulic chambers 11 and 12, As a result, the responsiveness of the relative rotational phase conversion of the vane member 9 is improved, and it is possible to immediately respond to changes in the engine operating state.

  Further, in this embodiment, as described above, when the ignition switch is turned on, the oil pump 20 is driven by the first explosion (start of cranking) immediately after that and the discharge hydraulic pressure is changed to the first supply / discharge passage 34. The first lock pin 26 and the second lock pin 27 are supplied to both the first and second pressure-receiving chambers 31a and 31b via the first and second pressure-receiving chambers 31a and 31b. It is possible to reliably maintain the engaged state in the first and second lock holes 24 and 25 by the combined force of the internal hydraulic pressure and the spring force of the first and second springs 29 and 30.

  Further, for example, immediately before the cranking is completed and the idling operation is started, as shown in FIG. 8, the second release pressure receiving chamber 33 becomes high pressure, and the second lock hole 25 is also connected via the branch path 19b. Accordingly, the hydraulic pressure of the advance oil passage 19 is supplied to a high pressure, so that the retraction operation of the second lock pin 27 from the second lock hole 25 is further improved, and the engagement by the second lock pin 27 is quickly performed. It can be canceled.

[Second Embodiment]
FIGS. 16 and 17 show the second embodiment, and the basic structure of the apparatus is the same as that of the first embodiment. However, the planar inner side surfaces 24a and 24b of the first lock hole 24 which are opposed to each other are connected to the sprocket body. 5 and the straight line Q passing through the center in the circumferential direction of the first lock hole 24 and the parallel line Q1.

  Therefore, also in this embodiment, the outer peripheral edge of the distal end portion of the first lock pin 26 always abuts on the line of the inner side surface 24a, so that even if a positional deviation in the radial direction occurs, the vane member 9 and the housing 7 It is possible to sufficiently suppress the shift of the relative rotational phase with respect to. Other functions and effects are the same as those of the first embodiment.

  The present invention is not limited to the configuration of the above embodiment, and the valve timing control device can be applied not only to the intake side but also to the exhaust side.

  Further, the inner side surface 24b on the other side of the first lock hole 24 is also formed along a radial line or a parallel line Q1 like the inner side surface 24a on the one side. .

It is a principal part longitudinal cross-sectional view which shows one Embodiment of the valve timing control apparatus of this invention. It is a perspective view of the valve timing control device. It is an effect explanatory view showing the state where valve timing by this embodiment was held in the middle control position. It is an operation explanatory view showing the state where valve timing by this embodiment was controlled to the retard side. It is effect | action explanatory drawing which shows the state which controlled the valve timing by this embodiment to the advance side. It is sectional drawing which shows typically the engagement / disengagement state of both the lock pins of the valve timing control apparatus at the time of an engine stop. It is sectional drawing which shows typically the engagement / disengagement state of both lock pins immediately after engine starting. It is sectional drawing which shows typically the engagement / disengagement state of both lock pins at the time of engine starting. It is sectional drawing which shows typically the engagement / disengagement state of both lock pins at the time of engine idling operation. It is sectional drawing which shows typically the engagement / disengagement state of both lock pins at the time of retardation control. It is sectional drawing which shows typically the engagement / disengagement state of both lock pins at the time of advance angle control. It is sectional drawing which shows typically the engagement / disengagement state of both lock pins in preparation for an engine stop. It is sectional drawing which shows typically the engagement / disengagement state of both lock pins at the time of an engine stop. It is a front view of the sprocket body which shows the 1st lock hole of a present Example. It is a principal part perspective view of the sprocket main body which shows the 1st lock hole of a present Example. It is a front view of the sprocket main body which shows the 1st lock hole of 2nd Example. It is a principal part perspective view of the sprocket main body which shows the 1st lock hole of a present Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Sprocket 2 ... Camshaft 3 ... Phase conversion mechanism 4 ... 1st hydraulic circuit 5 ... Sprocket main body 7 ... Housing 9 ... Vane member 10 ... Partition part 11 ... Retarded hydraulic chamber 12 ... Advance hydraulic chamber 16 ... Vane 18 ... Delay oil passage 19 ... Advance oil passage 20 ... Oil pump 20a ... Discharge passage 21 ... First electromagnetic switching valve 22 ... Drain passage 24 ... First lock hole 24a, 24b ... Inner side (inner wall surface)
25 ... 2nd lock hole 26 ... 1st lock pin 27 ... 2nd lock pin 28 ... 2nd hydraulic circuit 31a, 31b ... 1st, 2nd pressure receiving chamber 32.33 ... 1st, 2nd pressure receiving chamber 34, 35 ... first and second supply / discharge passages 36 ... second electromagnetic switching valve 37 ... passage component

Claims (1)

A drive rotator to which torque is transmitted from the crankshaft of the engine;
A driven rotator for transmitting the rotational force from the drive rotator to the camshaft;
A phase changing mechanism for rotating the driven rotor relative to the drive rotor within a predetermined rotation angle range;
A first lock pin and a second lock pin that are provided on one of the drive rotator and the driven rotator and are biased so as to protrude from the rotation axis direction toward the other rotator;
Provided on the other of the drive rotator and the driven rotator, and by engaging the respective leading end portions of the first lock pin and the second lock pin , the relative rotation position between the drive rotator and the driven rotator is maximized. A first lock hole and a second lock hole that are held between the advanced position and the most retarded position;
The tip of the first lock pin is formed in a bottomed cylindrical shape, and the outer diameter is formed smaller than the area of the bottom of the first lock hole ,
The first inner wall surface of the first lock hole that can be brought into contact with the first lock pin when the relative rotation phase of the phase changing mechanism is maintained is formed in a planar shape extending in the radial direction. A valve timing control device for an internal combustion engine.

Images