JP3817065B2 - Valve timing control device for internal combustion engine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a so-called vane type valve timing control device that makes opening / closing timings of engine valves, which are intake valves and exhaust valves of an internal combustion engine, variable according to operating conditions.
[0002]
[Prior art]
As a conventional vane type valve timing control device, for example, a device described in JP-A-8-121124 is known.
[0003]
Briefly, in this valve timing control device, the vane fixed to the end of the camshaft is rotatably housed in the cylindrical housing of the timing pulley whose opening end is closed by the front cover and the rear cover. And an advance side hydraulic chamber and a retard side hydraulic pressure between two substantially trapezoidal partition walls projecting inward from the diameter direction on the inner peripheral surface of the housing and the two vane parts of the vane. A room is defined. Then, hydraulic pressure is supplied to and discharged from each of the advance side and retard side hydraulic chambers according to the engine operating state, and the vane is rotated forward and backward by the driving hydraulic pressure to thereby rotate the relative rotation phase between the timing pulley and the camshaft. Is changed so that the opening / closing timing of the intake valve is variable.
[0004]
As is well known, positive and negative (forward rotation, reverse rotation) rotational fluctuation torque (alternating torque) is generated on the camshaft due to the spring force of the valve spring during engine operation. When a large rotational fluctuation torque is applied during rotational driving of the vane to the retard side or the advance side, the vane drive hydraulic pressure is defeated by the reaction force of the rotational fluctuation torque, and the vane is pushed back. Rotational behavior becomes unstable. That is, when the vane rotates, for example, toward the advance side, the drive hydraulic pressure supplied to the retard side hydraulic chamber loses the reaction force of the positive fluctuation torque, and as shown by the solid line in FIG. Rotate forward while repeating forward and reverse rotation (advance and retreat) to the angle side. Accordingly, since the camshaft also rotates relative to the timing pulley while repeating forward and reverse rotation, the control response of the valve spring, which is the opening / closing timing control of the engine valve, is lowered.
[0005]
Therefore, as in the technique described in Japanese Patent Application Laid-Open No. 8-121123, a pilot type check valve including a check valve and a pilot valve is provided inside the vane, and the advance side or the retard angle is determined by the operation of both valves. There is also provided one that restricts the reverse flow of the drive hydraulic pressure supplied to the hydraulic chamber on the side into the oil passage to prevent the vane from reversing due to the fluctuating torque.
[0006]
[Problems to be solved by the invention]
However, in this latter conventional example, the pilot check valve is used to prevent the backflow of the drive hydraulic pressure from, for example, the advance side hydraulic chamber, but this pilot type check valve is connected to the advance side hydraulic chamber. Since the operation is performed by directly using the supplied hydraulic pressure, the operation accuracy may be reduced due to a decrease in the hydraulic pressure holding capacity in the hydraulic chamber. That is, a minute gap is formed between the front and rear end surfaces of the vane that slides and rotates in the housing, and the front cover and the rear cover, in order to ensure good sliding rotation of the vane, but adjacent to each other. A large differential pressure is generated between the hydraulic chambers. For this reason, the hydraulic pressure supplied to the advance side hydraulic chamber may leak into the retarded side hydraulic chamber through a minute gap. As a result, there is a possibility that the check function of the pilot check valve is lowered and the backflow cannot be effectively prevented.
[0007]
The check function of the pilot check valve is also used when the seal member between the housing, front cover, and rear cover also leaks from the advance side hydraulic chamber to the outside due to deterioration after a long period of time. May be reduced.
[0008]
As a result, the same technical problem as that of the former conventional example is caused such that the control response of the valve timing is lowered.
[0009]
[Means for Solving the Problems]
The present invention has been devised in view of the actual situation of the conventional example, and the invention according to claim 1 has a rotating body that is driven to rotate by a crankshaft of an engine and a drive cam that operates an engine valve on the outer periphery. And a camshaft that is rotatable relative to the rotating body, a vane that is fixed to an end of the camshaft and has a plurality of blade portions that slide and rotate within the housing of the rotating body, and an inner peripheral surface of the housing A plurality of partition walls projecting inwardly, a retarded-side hydraulic chamber and an advanced-side hydraulic chamber defined between the respective partition sections and both side surfaces of each of the blade sections, and both the hydraulic pressures A hydraulic circuit that rotates the vane forward and backward by supplying and discharging hydraulic pressure relative to the chamber; and a regulation mechanism that regulates the oscillation vibration of the vane due to the rotational fluctuation torque acting on the camshaft when the engine is operated. A valve timing control device, wherein the regulating mechanism is: A cylindrical sheet member fixed in an operating hole formed in at least one blade portion of the vane, and provided on the outer periphery of the sheet member so as to be movable forward and backward. A plunger directed toward the inner peripheral surface of the housing, a high-pressure chamber in the plunger head and a reservoir chamber in the seat member separated by a partition wall included in the seat member, and a through-hole formed in the partition wall A check valve that opens and closes the communication passage to allow the hydraulic fluid to flow only from the reservoir chamber to the high-pressure chamber, a first passage that supplies and discharges hydraulic pressure to the reservoir chamber, and a high-pressure hydraulic fluid supplied to and discharged from the reservoir chamber A second passage for supplying and discharging into the room and a control valve that is slidably provided in the seat member and opens and closes the second passage according to the hydraulic pressure in the reservoir chamber. Have
[0010]
According to a second aspect of the present invention, the first passage is formed between the operation hole and the seat member, and communicates with the retard side or advance side hydraulic chamber, and a seat portion. The second passage is formed in the peripheral wall of the sheet member on the partition wall side with respect to the first through hole, while the second passage is formed in the peripheral wall of the sheet member. And a second passage hole facing the reservoir chamber, and a second passage groove formed between the outer peripheral surface of the sheet member and the inner peripheral surface of the plunger and communicating the second through hole and the high-pressure chamber. It is characterized by having.
[0011]
According to a third aspect of the present invention, the control valve is formed in a spool shape, and is provided on a side opposite to the valve body that slides in the seat member to open and close the second through hole. A pressure receiving portion that receives the hydraulic pressure of the reservoir chamber and moves the valve body in the closing direction of the second through hole, and a spring member that is elastically mounted on the rear end side of the pressure receiving portion and biases the valve body in the opening direction. It is characterized by that.
[0012]
According to a fourth aspect of the present invention, the rear end surface of the pressure receiving portion is provided adjacent to a hydraulic chamber on the other side opposite to the hydraulic chamber in which the plunger moves forward and backward, and the hydraulic pressure in the hydraulic chamber on the other side and the spring member The valve element is moved in the opening direction by a pressure cooperating with the spring force.
[0013]
Therefore, according to the present invention, when the vane is to be rotated from the retard side position to the advance side, for example, with the change of the engine operating state, the hydraulic pressure is supplied from the hydraulic circuit to the advance side hydraulic chamber. At the same time, hydraulic pressure is supplied from the first passage into the reservoir chamber. Accordingly, the vane starts to rotate toward the advance side due to the increase in the hydraulic pressure in the advance side hydraulic chamber, while the valve body slides to one side against the spring force of the spring member as the hydraulic pressure in the reservoir chamber increases. To close the second passage. For this reason, the hydraulic pressure in the reservoir chamber pushes the check valve from the communication passage and flows into the high-pressure chamber, and pushes the plunger, for example, in the direction of one side surface of the partition wall to come into contact therewith.
[0014]
Here, the rotational fluctuation torque transmitted from the camshaft acts, and for example, a reaction force that tries to push back the vane to the retard side against the hydraulic pressure supplied to the advance side hydraulic chamber by the positive fluctuation torque. When acted, the plunger overcomes the positive fluctuation torque by the pressure reaction force against the one side surface of the partition wall, that is, the thrust, by the hydraulic pressure of the sealed high pressure chamber. For this reason, the vane rotates rapidly toward the advance side while the reverse rotation is reliably restricted as the plunger advances during rotation. Here, the negative rotational fluctuation torque acts as an assist force for rotating the vane toward the advance side.
[0015]
In addition, when the engine operating state changes and the vane is to be rotated from the maximum advance position to the retard side, when the hydraulic pressure is supplied from the hydraulic circuit to the retard side hydraulic chamber, the oil pressure is reduced. The second passage is opened to act on the rear end surface of the pressure receiving portion and push out the valve body by the combined force of the hydraulic pressure and the spring force of the spring member. For this reason, the hydraulic pressure in the high pressure chamber once flows into the reservoir chamber once through the second passage, and then flows back through the first passage and is discharged to the outside through the advance side hydraulic chamber. Accordingly, the plunger is immediately released from the protruding tension on the one side surface of the partition wall, and freely moves backward. Thus, the vane can be quickly rotated to the retard side by the hydraulic pressure in the retard side hydraulic chamber.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
1 to 4 show an embodiment of a valve timing control device for an internal combustion engine according to the present invention, which is applied to an intake valve side.
[0017]
That is, a timing sprocket 1 that is a rotating body that is rotationally driven via a timing chain by a crankshaft (not shown) of the engine, a camshaft 2 that is provided to be rotatable relative to the timing sprocket 1, and the camshaft 2, a vane 3 fixed to the end of 2 and rotatably accommodated in the timing sprocket 1, a hydraulic circuit 4 that rotates the vane 3 forward and backward by hydraulic pressure, and a relative rotation between the timing sprocket 1 and the vane 3. A lock mechanism 10 that locks at the rotation position on the maximum retard angle side, and a restriction mechanism 20 that restricts the oscillation vibration of the vane accompanying the positive rotational fluctuation torque acting on the camshaft 2 are provided.
[0018]
As shown in FIG. 4, the timing sprocket 1 includes a rotating member 5 having a tooth portion 5 a that engages with a timing chain on the outer periphery, and a cylinder that is disposed in front of the rotating member 5 and rotatably accommodates the vane 3. A housing 6, a disc-shaped front cover 7 serving as a lid that closes the front end opening of the housing 6, and the housing 6 and the rotating member 5. The rotating member 5, the housing 6, the front cover 7, and the rear cover 8 are integrally coupled from the axial direction by four small-diameter bolts 9.
[0019]
The rotating member 5 has a substantially annular shape, and has four female screw holes 5b through which the small-diameter bolts 9 are screwed in the circumferentially equidistant positions of about 90 ° in the front-rear direction. A fitting hole 11 having a stepped diameter, through which a sleeve 25 described later is fitted, is formed through. Further, a disc-like fitting groove 12 into which the rear cover 8 is fitted is formed on the front end surface.
[0020]
The housing 6 has a cylindrical shape with openings at the front and rear ends, and four partition wall portions 13 project from the circumferential position of the inner peripheral surface at 90 °. The partition wall 13 has a trapezoidal shape in cross section, is provided along the axial direction of the housing 6, and both front and rear end edges are flush with the both end edges of the housing 6. On the side, four bolt insertion holes 14 through which the small-diameter bolts 9 are inserted are formed in the axial direction. Further, a U-shaped seal member 15 and a leaf spring 16 that presses the seal member 15 inward are fitted and held in a holding groove 13a that is cut out along the axial direction at the center position of the inner end face of each partition wall portion 13. Has been.
[0021]
Further, the front cover 7 has a relatively large-diameter bolt insertion hole 17 formed in the center, and four bolt holes 18 formed at positions corresponding to the bolt insertion holes 14 of the housing 6. ing.
[0022]
The rear cover 8 has a disc portion 8a fitted and held in the fitting groove 12 of the rotating member 5 on the rear end surface, and a small-diameter annular portion 25a of the sleeve 25 is fitted in the center. A fitting hole 8c is formed, and four bolt holes 19 are similarly formed at positions corresponding to the bolt insertion holes 14.
[0023]
The camshaft 2 is rotatably supported at the upper end of the cylinder head 22 via a cam bearing 23, and an unillustrated cam for opening the intake valve via a valve lifter is integrally provided at a predetermined position on the outer peripheral surface. In addition, a flange portion 24 is integrally provided at the front end portion.
[0024]
The vane 3 is integrally formed of a sintered alloy material and is cammed by a fixing bolt 26 inserted from the axial direction through the sleeve 25 in which the front and rear portions are fitted in the flange portion 24 and the fitting hole 11, respectively. An annular rotor portion 27 that is fixed to the front end portion of the shaft 2 and has a bolt insertion hole 27a through which the fixing bolt 26 is inserted at the center, and a 90 ° position in the circumferential direction of the outer peripheral surface of the rotor portion 27 are integrated. And four blade portions 28 provided on the surface.
[0025]
As for the said 1st-4th blade | wing part 28, three exhibit a cross-sectional rectangular shape, another one exhibits a cross-sectional substantially inverted trapezoid shape, and each is arrange | positioned between each partition part 13, and each outer peripheral surface A U-shaped seal member 30 slidably contacting the inner peripheral surface 6a of the housing 6 and a leaf spring 31 that presses the seal member 30 outward are fitted and held in a holding groove 29 cut in the center in the axial direction. . Further, four advance-side hydraulic chambers 32 and retard-side hydraulic chambers 33 are formed between both sides of each blade 28 and both sides of each partition 13.
[0026]
As shown in FIGS. 1 and 3, the hydraulic circuit 4 supplies and discharges hydraulic pressure to and from the first hydraulic passage 41 that supplies and discharges hydraulic pressure to the advance side hydraulic chamber 32 and the retard side hydraulic chamber 33. There are two systems of hydraulic passages, the second hydraulic passage 42, and a supply passage 43 and a drain passage 44 are connected to both the hydraulic passages 41, 42 via a passage switching electromagnetic switching valve 45. Yes. The supply passage 43 is provided with an oil pump 47 that pumps the oil in the oil pan 46, while the downstream end of the drain passage 44 communicates with the oil pan 46.
[0027]
The first hydraulic passage 41 is branched from the cylinder head 22 in the head portion 26a through the first passage portion 41a formed in the shaft center of the camshaft 2 and the internal axial direction of the fixing bolt 26. The first oil passage 41b that communicates with the first passage portion 41a, and the first oil formed between the small-diameter outer peripheral surface of the head portion 26a and the inner peripheral surface of the bolt insertion hole 27a in the base portion 27 of the vane 3. The oil chamber 41c communicates with the passage 41b, and four branch passages 41d that are formed substantially radially in the base portion 27 of the vane 3 and communicate with the oil chamber 41c and each advance-side hydraulic chamber 32.
[0028]
On the other hand, the second hydraulic passage 42 is formed into a second passage portion 42a formed inside the cylinder head 22 and one side of the camshaft 2 and the inside of the sleeve 25 so as to be bent in a substantially L shape. A second oil passage 42b communicating with the passage portion 42a, four oil passage grooves 42c formed at the outer peripheral side edge of the fitting hole 11 of the rotating member 5 and communicating with the second oil passage 42b, and the periphery of the rear cover 8. The four oil holes 42 d are formed at positions of about 90 ° in the direction and communicate with each oil passage groove 42 c and the retard side hydraulic chamber 33.
[0029]
The electromagnetic switching valve 45 is a 4-port 2-position type, and an internal valve body is configured to relatively switch and control the hydraulic passages 41, 42, the supply passage 43, and the drain passage 44, and Switching is performed by a control signal from the controller 48. The electromagnetic switching valve 45 switches between the supply passage 43 and the drain passage 44 relatively, but the switching operation is performed intermittently in a short time. The controller 48 detects the current operating state based on signals from a crank angle sensor that detects the engine speed and an air flow meter that detects the amount of intake air, and the timing sprocket 1 and the cam based on signals from the crank angle and cam angle sensors. The relative rotation position with respect to the shaft 2 is detected.
[0030]
As shown in FIGS. 4 and 5, the lock mechanism 10 includes an engagement groove 5c formed at a predetermined position on the outer peripheral side of the fitting groove 12 of the rotating member 5, and the rear cover 8 corresponding to the engagement groove 5c. The inner peripheral surface is formed in a substantially central position of the one blade portion 28 corresponding to the engagement hole 21 along the inner axial direction. A sliding hole 35, a lock pin 34 slidably provided in the sliding hole 35 of the one blade portion 28, and a coil which is a spring member elastically mounted on the rear end side of the lock pin 34 The spring 39 includes an annular pressure receiving chamber 40 formed between the lock pin 34 and the sliding hole 35.
[0031]
When the vane 3 rotates to the maximum retard angle side, the lock pin 34 advances by the spring force of the coil spring 39 and the tip engaging portion 34a engages with the engaging hole 21 so that the vane 3 is moved to the rear cover 8. Is supposed to be locked. On the other hand, at the time of rotation to the advance side, the same hydraulic pressure is supplied to the annular pressure receiving chamber 40 through the oil hole 36 simultaneously with the supply of the hydraulic pressure to the advance side hydraulic chamber 32, and the lock pin 34 is moved to the spring of the coil spring 39. The engagement portion 34a and the engagement hole 21 are unlocked by moving backward against the force.
[0032]
As shown in FIGS. 1 and 2, the regulating mechanism 20 is provided in one blade portion 28 having a large thickness in the circumferential direction, and has an internal circle from a side surface facing the retarded-side hydraulic chamber 33 of the blade portion 28. A bottomed cylindrical operating hole 50 formed along the circumferential direction, a cylindrical sheet member 51 fixed inside the operating hole 50, and a retarded side hydraulic pressure on the outer peripheral surface of the sheet member 51 Plunger 52 slidably provided so as to be able to advance and retreat in the direction of chamber 33, formed in front of and behind partition wall 51 a on the inner front end side of sheet member 51, that is, inside seat member 51 and inside distal end head 52 a of plunger 52. The reservoir chamber 53 and the high-pressure chamber 54, and the check valve 56 that opens and closes the communication passage 55 formed in the center of the partition wall 51a to allow the hydraulic pressure of the reservoir chamber 53 to flow only into the high-pressure chamber 54; Communicating with the first hydraulic passage 41, front A first passage 57 that supplies and discharges hydraulic pressure to and from the reservoir chamber 53, a second passage 58 that supplies and discharges hydraulic oil supplied to and discharged from the reservoir chamber 53 into the high-pressure chamber 54, and slides into the seat member 51. A spool-shaped control valve 59 that is freely provided and opens and closes the second passage 58 is mainly configured.
[0033]
The operating hole 50 is composed of a sliding hole portion of the plunger 52 facing the advance side hydraulic chamber 32 and a small-diameter groove portion 50a on the rear end side, and the inner peripheral surface of the sliding hole portion is the plunger 52. The outer peripheral surface of the plunger 52 is slidably disposed so as to have an inner diameter slightly larger than the outer diameter.
[0034]
The sheet member 51 is press-fitted and fixed in the small-diameter groove portion 50a formed with a rear end portion 51b on the bottom side of the sliding hole portion.
[0035]
The plunger 52 has a cylindrical shape with a lid, the front end surface of the head portion 52a at the tip is formed in a spherical shape, and the one side surface in which the head portion 52a is cut out in a curved cross section of one partition wall portion 13. 13a is arranged in contact with.
[0036]
The check valve 56 is provided inside the high-pressure chamber 54, and a ball valve body 62 that opens and closes the communication passage 55, and a valve spring 64 that urges the ball valve body 62 in a closing direction via a cup-shaped retainer 63. And a compression spring 65 which is elastically mounted between the bottom wall of the plunger tip 52a and the outer peripheral flange portion of the retainer 63 and holds the retainer 63, the ball valve body 62 and the like in the direction of the partition wall 51a. Yes.
[0037]
Further, a side hole 63 a for introducing hydraulic pressure into the high pressure chamber 54 when the ball valve body 62 is opened is provided on the cup surface of the retainer 63.
[0038]
The first passage 57 is formed between the sliding hole portion of the operation hole 50 and the outer peripheral surface of the seat member 51, and communicates with the first passage groove 57 a communicating with the branch passage 41 d of the first hydraulic passage 41. The first end hole 51b is formed in the peripheral wall of the rear end portion 51b of the seat portion 51 along the diameter direction and communicates the first passage groove 57a and the reservoir chamber 53.
[0039]
The second passage 58 is formed in the vicinity of the partition wall 51a of the sheet member 51 along the diametrical direction, the second through hole 58a facing the reservoir chamber 53, the outer peripheral surface of the sheet member 51 on the partition wall 51a side, and the plunger. The cylindrical second passage groove 58 b is formed between the second through hole 58 a and the high pressure chamber 54.
[0040]
The control valve 59 is provided through a valve shaft on the opposite side of the valve body 59a and a valve body 59a that opens and closes the second through hole 58a by sliding inside the partition wall 51a side of the reservoir chamber 53. A spring member that is formed between the pressure receiving portion 59b that slides in the rear end portion 51b of the seat member 51, and the bottom surface of the pressure receiving portion 59b and the small-diameter groove portion 50a, and biases the valve body 59a in the opening direction. And return spring 59c.
[0041]
The valve body 59a has a substantially U-shaped cross section, and its length is set to be substantially the same as the length of the partition wall 51a and the vicinity of the hole edge of the second through hole 58a, and the front edge is the partition wall 51a. The second through hole 58a is fully opened at the stage of contact with the end face, while the second through hole 58a is fully closed with the pressure receiving part 58b in contact with the bottom surface of the small diameter groove part 50a. ing. The valve body 59a has a plurality of through holes 60 that allow the reservoir chamber 53 and the communication passage 55 to communicate with each other.
[0042]
The pressure receiving portion 58b has a substantially U-shaped cross section like the valve body 59a, the front end surface on the reservoir chamber 53 side is formed as a first pressure receiving surface, the rear end surface is formed as a second pressure receiving surface, The pressure receiving chamber 61 formed between the pressure receiving surface and the inner surface of the rear end portion 51b of the sheet member 51 has a hydraulic pressure in the retard side hydraulic chamber 33 through a through hole 28a formed in the base end portion of the blade portion 28. Is to be supplied. Therefore, a combined force of the spring force of the return spring 59c and the hydraulic pressure in the pressure receiving chamber 61 acts on the second pressure receiving surface.
[0043]
The return spring 59c is set to a small set load that urges the valve body 59a in the opening direction when no hydraulic pressure acts on the reservoir chamber 53 or the pressure receiving chamber 61.
[0044]
Hereinafter, the operation of the present embodiment will be described. First, at the time of engine start and idling operation, the electromagnetic switching valve 48 to which a control signal is output from the controller 48 causes the supply passage 43 and the second hydraulic passage 42 to communicate with each other, and the drain passage 44 and the first hydraulic passage 41 communicate with each other. Let For this reason, the hydraulic pressure pumped from the oil pump 47 is supplied to the retard-side hydraulic chamber 33 through the second hydraulic passage 42 (oil passage groove 42c → oil hole 42d), while the advanced-side hydraulic chamber 32 has In the same way as when the engine is stopped, the hydraulic pressure is not supplied and the low pressure state is maintained. For this reason, as shown in FIG. 1, the vane 3 is in a state in which each blade portion 28 is in contact with one side surface of each partition wall portion 13 on the advance side hydraulic chamber 32 side.
[0045]
Accordingly, the relative rotational position of the timing sprocket 1 and the camshaft 2 is held on one side (retarded side), and the opening / closing timing of the intake valve is controlled to the retarded side. As a result, the combustion efficiency by using the inertial intake air is improved, and the engine rotation can be stabilized and the fuel consumption can be improved.
[0046]
Here, as shown in FIGS. 1 and 2, the regulating mechanism 20 presses the second pressure receiving surface of the pressure receiving portion 59 b by the spring force of the return spring 59 c and the hydraulic pressure supplied to the retard side hydraulic chamber 33. Then, the valve body 59a is pressed against the partition wall 51a, and the second through hole 58a is fully opened. For this reason, since the plunger 52 is in a low pressure state in the high pressure chamber 54, it does not move forward (elongation stroke), and the partition portions of the other three vanes 28 by the hydraulic pressure of the retard side hydraulic chamber 33 are used. Similarly to the abutment on one side surface 13, the front end head 52a abuts on the opposite side surface 13a.
[0047]
Thereafter, when the vehicle starts and the engine shifts from the low rotation / low load range to the normal rotation / medium rotation / medium load range, the electromagnetic switching valve 45 is actuated by the control signal from the controller 48, thereby supplying the supply passage 43 and the first hydraulic pressure. While the passage 41 is in communication, the drain passage 44 and the second hydraulic passage 42 are in communication. Accordingly, the hydraulic oil in the retarded hydraulic chamber 33 is now returned to the oil pan 46 from the drain passage 44 through the second hydraulic passage 42, and the retarded hydraulic chamber 33 is reduced in pressure while being advanced. The hydraulic pressure is supplied into the side hydraulic chamber 32 via the first oil passage 41a → 41b → branch passage 41d and becomes high pressure. For this reason, the vane 3 rotates clockwise from the position shown in FIG. 1 so that each vane portion 28 passes through the intermediate position shown in FIG. 7 and is on the opposite side (retarding side hydraulic chamber side) as shown in FIG. It rotates to the maximum advance angle position in contact with the other side surface of each partition wall 13.
[0048]
Therefore, the timing sprocket 1 and the camshaft 2 are relatively rotated to the other side to control the opening / closing timing of the intake valve to the advance side. As a result, the pump loss of the engine is reduced and the output can be improved.
[0049]
When the restriction mechanism 20 is switched from the retarded angle side to the advanced angle side, the hydraulic pressure in the retarded angle side hydraulic chamber 33 is drained as described above to become a low pressure state. The hydraulic pressure is also returned to the retarded-side hydraulic chamber 33 through the through hole 28a and becomes low pressure. On the other hand, the hydraulic pressure supplied to the advance side hydraulic chamber 32 flows into the reservoir chamber 53 through the first passage groove 57a and the first through hole 57b of the first passage 57 as shown by the arrows in FIGS. Then, the first pressure receiving surface of the pressure receiving portion 59b is pressed against the spring force of the return spring 59c to press the pressure receiving portion 59b against the bottom surface of the small diameter groove portion 50a. Accordingly, the valve body 59a slides in the direction of the pressure receiving chamber 61 via the valve shaft as shown in FIGS. 6 to 8, and the second through hole 58a is fully closed. For this reason, the communication between the high pressure chamber 54 and the reservoir chamber 53 via the second passage 58 is blocked, while the hydraulic pressure in the reservoir chamber 53 passes through each through hole 60 of the valve body 59a from the communication passage 55 to the valve spring 64. The ball valve body 62 flows into the high-pressure chamber 54 while pushing the ball valve body 62 against the spring force.
[0050]
For this reason, the plunger 52 advances (extends) as shown in FIGS. 6 to 8 according to the rotation stroke amount from the position shown in FIG. The state of constantly contacting the side surface 13a is maintained.
[0051]
Here, when a positive fluctuation torque among the fluctuation torques transmitted from the camshaft 2 to the vane 3 acts and the blade portion 28 is temporarily rotated counterclockwise, the plunger 52 is moved by the ball valve body 62. Since the backward movement is restricted by the hydraulic pressure of the closed high pressure chamber 54, so-called impulsive tension acts on the counterclockwise rotation of the vane 3 with respect to the positive fluctuation torque to overcome the positive fluctuation torque. Therefore, the vane 3 is reliably restricted from rotating counterclockwise (retarded side) as the plunger 52 advances during rotation from the most retarded angle side to the most advanced angle side as indicated by the broken line in FIG. While rotating, it rotates quickly in the clockwise direction (advance side).
[0052]
Therefore, the relative rotational speed of the timing sprocket 1 and the camshaft 2 toward the advance side is increased, and the control response of the valve timing is improved.
[0053]
Here, since the negative rotational fluctuation torque acts as an assisting force that rotates the vane 3 toward the advance side, the control response of the valve timing is further improved.
[0054]
On the other hand, when the engine intermediate rotation load range shifts to the high rotation high load range, the hydraulic oil is discharged from the advance side hydraulic chamber 32 as shown in FIG. This hydraulic pressure is supplied to the reservoir chamber 53 via the first passage 57. Therefore, as shown in FIG. 9, the valve body 59a of the control valve 59 has a combined force of the rising hydraulic pressure in the pressure receiving chamber 61 and the spring force of the return spring 59c, and further the rotational centrifugal force of the device, in the direction of the partition wall 51a. The second through hole 58a is opened. Therefore, the hydraulic oil in the high pressure chamber 54 once flows into the reservoir chamber 53 through the second passage 58, and is discharged from here through the first passage 57 and the advance side hydraulic chamber 32 to the drain passage 44. Therefore, the plunger 64 is released from the protruding tension immediately on the one side surface 13a of the partition wall portion and freely moves backward.
[0055]
Accordingly, the vane 3 can be quickly rotated counterclockwise (retarded side) by the hydraulic pressure in the retarded hydraulic chamber 33, and the timing sprocket 1 and the camshaft 2 are relatively rotated to one side. In addition, the opening / closing timing of the intake valve can be controlled to the retard side with good responsiveness. As a result, the output can be improved by improving the intake charge efficiency.
[0056]
At this time, since the discharge pressure of the oil pump 47 is also increased as the engine speed increases, the vane 3 rotated and held at the maximum retard position is advanced by the high hydraulic pressure in the retard side hydraulic chamber 33. It is strongly pressed toward the partition wall 13 on the corner side hydraulic chamber 32 side. Therefore, the oscillation vibration (flapping) of the vane 3 due to the positive / negative fluctuation torque is suppressed.
[0057]
Further, when shifting to a predetermined engine operating state and holding the vane 3 at the intermediate rotational position, the electromagnetic switching valve 45 is intermittently switched from the controller 48 to cause the advance side hydraulic chamber 32 and the retard angle. The hydraulic pressure is relatively supplied to and discharged from the side hydraulic chamber 33, and a substantially uniform hydraulic pressure is supplied to the hydraulic chambers 32 and 33. Therefore, each vane portion 28 of the vane 3 is held at a substantially intermediate position between the advance side and the retard side as shown in FIG. 10, and the relative position between the timing sprocket 1 and the camshaft 2 is held at the intermediate rotation position. To do. At this time, the reservoir chamber 53 and the pressure receiving chamber 61 are supplied with substantially uniform pressure as in the hydraulic chambers 32 and 33, so that the valve element 59a is attached to the partition wall 51a side by the spring force of the return spring 59c. Thus, the second through hole 58a is opened. Therefore, the plunger 52 is released from the projecting tension, but at this time, the vane 3 is only held at the intermediate position. There is no problem.
[0058]
Further, in the operating range where the engine is rotating at a high speed or when the vane 3 is held at the intermediate position, the plunger 52 is not in strong pressure contact with the partition wall portion 13 but only in elastic contact with the small spring force of the coil spring 65. Generation | occurrence | production of abrasion of the partition part 13 and the plunger head 52a is suppressed.
[0059]
Further, when the engine is stopped, the supply of hydraulic pressure to the hydraulic chambers 32 and 33 is stopped, so that the valve body 59a is pressed toward the partition wall 51a by the spring force of the return spring 59c to open the second through hole 58a. Therefore, the high pressure chamber 54 is in a low pressure state, and the thrust of the plunger 52 is released. In this state, the spring force of the valve spring (not shown) of the intake valve acts on the vane 3 via the camshaft 2 to rotate the vane 3 to the retard side. Therefore, at the time of restart, the valve timing is controlled in advance to the retard side, so that the startability as described above is improved. Further, since the vane 3 is locked by the lock pin 34 of the lock mechanism 10 at the maximum retarded angle position at the time of starting, the oscillation vibration of the vane 3 due to positive and negative rotational fluctuation torque is suppressed.
[0060]
Further, by restricting the counterclockwise rotation of the vane 3 by the regulating mechanism 20, an external leakage of hydraulic pressure from the advance side hydraulic chamber 32 due to temporary high pressure of the advance side hydraulic chamber 32 due to fluctuating torque. Therefore, the consumption of hydraulic oil can be reduced.
[0061]
The present invention is not limited to the configuration of the above-described embodiment, and for example, two or more regulating mechanisms 20 can be provided in each blade portion 28. Furthermore, the plunger 52 can be arranged in the opposite direction to restrict the return of rotation with respect to the negative fluctuation torque during the rotation of the vane 3 from the advance side to the retard side. It is also possible to configure.
[0062]
It is also possible to form a hydraulic circuit for the hydraulic pressure supplied to the high pressure chamber 54 independently of the hydraulic circuit 4 of each hydraulic chamber 32, 33.
[0063]
【The invention's effect】
As is apparent from the above description, according to the present invention, when the vane rotates from the retard side to the advance side or from the advance side to the retard side, the vane reverses due to positive and negative rotational fluctuation torque by the regulation mechanism. Therefore, the rotational speed of the vane in one direction is increased, and the responsiveness of the valve timing control is improved.
[0064]
In addition, according to the present invention, the control mechanism opens and closes the control valve mainly by the hydraulic pressure in the reservoir chamber and the spring force of the spring member, instead of directly closing the oil passage by directly using the hydraulic pressure of each hydraulic chamber as in the conventional example. At the same time, since the hydraulic pressure is supplied to the high-pressure chamber by operating the control valve and the plunger is advanced and pressed against the opposing wall to counter the fluctuating torque, the hydraulic pressure in each hydraulic chamber leaks to the outside. Even if the pressure becomes low, the movement of the plunger is not affected at all, and a stable and reliable regulation action is always obtained.
[0065]
Therefore, especially when the pump rotational speed is low and the pump discharge pressure is small as in the case of low engine speed, the plunger can be moved forward to effectively suppress the oscillation vibration caused by the rotational fluctuation torque.
[Brief description of the drawings]
FIG. 1 is a view taken along the line AA in FIG. 3 showing a first embodiment of the present invention.
FIG. 2 is a partially enlarged view of the present embodiment.
3 is a cross-sectional view taken along line BB in FIG.
FIG. 4 is an exploded perspective view of the present embodiment.
FIG. 5 is a cross-sectional view of a lock mechanism provided in the present embodiment.
FIG. 6 is an operation explanatory view showing a rotation intermediate position toward the vane advance angle side of the embodiment.
FIG. 7 is an operation explanatory view showing a rotation intermediate position toward the vane advance angle side of the embodiment.
FIG. 8 is an explanatory diagram of the operation at the time of the vane maximum advance angle according to the present embodiment.
FIG. 9 is an explanatory diagram of the action at the time of rotation conversion from the maximum advance angle to the retard angle side of the vane.
FIG. 10 is an operation explanatory view showing intermediate rotation position control of a vane.
FIG. 11 is a rotational characteristic diagram of the vane of this embodiment and the conventional example.
[Explanation of symbols]
1. Timing sprocket (rotating body)
2 ... Camshaft
3 ... Vane
4 ... Hydraulic circuit
6 ... Housing
6a ... Inner surface
7 ... Front cover
13 ... partition wall
13a ... One side
20 ... Regulatory mechanism
28 ... feather part
32 ... Advance side hydraulic chamber
33 ... retarded-side hydraulic chamber
50. Operation hole
51. Sheet member
51a ... partition wall
52 ... Plunger
53 ... Reservoir chamber
54 ... High pressure chamber
55 ... Communication passage
56 ... Check valve
57 ... 1st passage
58 ... Second passage
59 ... Control valve
61 ... Pressure receiving chamber

Claims (4)

A rotating body that is rotationally driven by the crankshaft of the engine, a camshaft having a drive cam that operates an engine valve on the outer periphery and that can rotate relative to the rotating body, and a rotating body that is fixed to the end of the camshaft A vane having a plurality of blade portions that slide and rotate in the housing, a plurality of partition walls projecting inwardly on the inner peripheral surface of the housing, each partition wall portion, and both side surfaces of each blade portion A retarding-side hydraulic chamber and an advancing-side hydraulic chamber, a hydraulic circuit for supplying and discharging hydraulic pressure relatively to both the hydraulic chambers to rotate the vane forward and reverse, and the cam during engine operation A valve timing control device comprising a regulation mechanism for regulating the oscillation vibration of the vane accompanying the rotational fluctuation torque acting on the shaft,
The regulating mechanism is provided with a cylindrical sheet member fixed in an operating hole formed in at least one blade portion of the vane, and is provided on the outer periphery of the sheet member so as to be movable forward and backward. The partition wall or the plunger directed toward the inner peripheral surface of the housing, the high pressure chamber in the plunger head and the reservoir chamber in the seat member separated by the partition wall provided in the seat member, and the partition wall A check valve that allows the hydraulic fluid to flow only from the reservoir chamber to the high-pressure chamber side by opening and closing the communication passage formed through the pressure chamber, and the hydraulic pressure supplied to and discharged from the advance-side hydraulic chamber or the retard-side hydraulic chamber A first passage for supplying and discharging the reservoir chamber; a second passage for supplying and discharging the hydraulic fluid supplied and discharged into the reservoir chamber; and a slidable member provided in the seat member, and at least in the reservoir chamber. oil Closing the second passage by but supplied, is composed of a control valve for opening said second passage by being pressed against the advance side hydraulic chamber or supplied to the retard side hydraulic chamber pressure A valve timing control device for an internal combustion engine, wherein the plunger is moved in the advancing direction by hydraulic pressure supplied from one of the hydraulic chambers to the reservoir chamber via the first passage .   The first passage is formed between the actuation hole and the seat member, and is formed in the reservoir through a first passage groove communicating with the retard side or advance side hydraulic chamber, and a peripheral wall of the seat portion. The second passage is formed in the peripheral wall of the sheet member closer to the partition wall than the first passage, and faces the reservoir chamber. And a second passage groove formed between the outer peripheral surface of the seat member and the inner peripheral surface of the plunger and communicating the second through hole and the high pressure chamber. Item 2. A valve timing control device for an internal combustion engine according to Item 1.   The control valve is formed in a spool shape, and is provided on a side opposite to the valve body that opens and closes the second through hole by sliding in the seat member, and receives the hydraulic pressure in the reservoir chamber. A pressure receiving portion that moves the body in the closing direction of the second through hole, and a spring member that is elastically mounted on the rear end side of the pressure receiving portion and biases the valve body in the opening direction. Item 3. A valve timing control device for an internal combustion engine according to Item 1 or 2.   The rear end surface of the pressure receiving portion is provided adjacent to the hydraulic chamber on the other side opposite to the hydraulic chamber where the plunger moves forward and backward, and the pressure of the cooperation between the hydraulic pressure in the hydraulic chamber on the other side and the spring force of the spring member 4. The valve timing control apparatus for an internal combustion engine according to claim 3, wherein the valve body is moved in the opening direction.

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