JP2004092577A - Valve timing control device for internal combustion engine - Google Patents

Abstract

An object of the present invention is to eliminate noise and wear caused by line contact of a rotation urging spring, thereby improving quietness and durability.
An assembly angle between a drive ring (3) and a driven shaft member (7) is operated by a spring (47) for urging the retard side and a hysteresis brake (20) for urging the advance side. In such a valve timing control device, the mainspring spring 47, which is a rotation urging spring, is immersed in the lubricating liquid, so that the sliding contact between adjacent parts of the spring is sufficiently lubricated with the lubricating liquid.
[Selection diagram] Fig. 1

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a valve timing control device for an internal combustion engine that variably controls the opening / closing timing of an intake-side or exhaust-side engine valve of the internal combustion engine in accordance with an operating state.
[0002]
[Prior art]
The following has been devised as this type of valve timing control device.
[0003]
In this valve timing control device, a housing (driving rotating body) linked to a crankshaft via a timing chain or the like is rotatably assembled to an end of a camshaft, and a radial guide formed on an inner end surface of the housing. A movable guide portion is slidably engaged in the radial direction and supported, and a lever shaft (a driven rotating body) having a lever protruding outward in the radial direction is bolted to an end of the camshaft. The part and the lever of the lever shaft are pivotally connected by a link. An intermediate rotating body having a spiral guide is provided at a position facing the radial guide so as to be rotatable relative to the housing and the lever shaft, and is provided at one end of the movable guide portion in the axial direction. A plurality of projecting substantially arc-shaped projections are guided and engaged with the spiral guide. The intermediate rotator is biased by a mainspring toward the side that advances the rotation with respect to the housing, and receives an appropriate force on the side that delays the rotation by an electromagnetic brake that is an operation actuator.
[0004]
In the case of this device, when the electromagnetic brake is in the OFF state, the intermediate rotating body is located at the initial position with respect to the housing under the urging force of the mainspring spring, and the movable guide portion that meshes with the spiral guide with a ridge is provided. It is maximally displaced radially outward, causing a link to maintain the assembly angle between the housing and the camshaft at the most retarded position or the most advanced position. Then, when the electromagnetic brake is turned ON from this state, the intermediate rotating body is decelerated and relatively rotates with respect to the delay side with respect to the housing. As a result, the movable guide portion meshing with the spiral guide is displaced radially inward, The assembling angle between the housing and the camshaft is changed to the most advanced position or the most retarded position by gradually tilting the link that has been caused so far.
[0005]
[Patent Document 1]
JP 2001-41013 A
[Problems to be solved by the invention]
However, in the case of this conventional valve timing control device, since a spring is used as an urging means for urging the assembly angle to one of the retard side and the advance side, the load on the spring is limited. At the time of input, adjacent portions of the spring come into line-to-line contact due to deformation of the spring, which causes a problem that noise and wear of the spring are caused. Then, when the spring is worn, it is feared that the spring characteristics are deteriorated and the durability is lowered.
[0007]
The problem of such line-to-line contact of the spring is not limited to the case of using the above-mentioned spring, but it is a spiral or coil-shaped spring, and the rotation between adjacent parts slides due to deformation at the time of load input. The same occurs when an urging spring is used.
[0008]
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a valve timing control device for an internal combustion engine which is excellent in quietness and durability by eliminating abnormal noise and wear due to line contact of the rotation biasing spring. .
[0009]
[Means for Solving the Problems]
As a means for solving the above-mentioned problem, the invention of this application is such that a sliding contact portion between adjacent portions of a spring can be sufficiently lubricated with a lubricating liquid by immersing a rotary biasing spring in a lubricating liquid. . Therefore, according to the invention of this application, generation of abnormal noise and wear at the contact portion of the rotation urging spring can be reliably prevented.
[0010]
It is preferable that the rotation urging spring is accommodated in a lubricating liquid chamber, and that the inner wall of the liquid chamber regulates excessive displacement of the rotation urging spring. In this case, the volume of the lubricating liquid chamber can be reduced, and a change in spring characteristics due to excessive deformation of the rotation urging spring can be prevented.
[0011]
Further, the rotation urging spring may be formed of a mainspring, and a side end of the mainspring may be formed in an arc-shaped cross section. In this case, the installation space can be reduced by using the mainspring, and since the side end of the mainspring has an arc-shaped cross-section, the edge of the side end of the mainspring is connected to another part of the same spring. Wear and damage of the spring due to contact with the surrounding members.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, an embodiment of the invention of this application will be described based on the drawings.
[0013]
In this embodiment, the valve timing control device according to the invention of this application is applied to a power transmission system on the intake side of an internal combustion engine. However, the valve timing control device can be similarly applied to a power transmission system on the exhaust side.
[0014]
As shown in FIG. 1, the valve timing control device is rotatable relative to a camshaft 1 rotatably supported by a cylinder head (not shown) of an internal combustion engine, and can rotate relative to the front end of the camshaft 1 as necessary. Ring (drive rotary member) having a timing sprocket 2 on its outer periphery, which is linked to a crankshaft (not shown) via a chain (not shown), and the drive ring 3 and the camshaft 1 1 is arranged on the front side (the left side in FIG. 1) of the assembling angle operating mechanism 4 for operating the assembling angle of the both 3 and 1; FIG. 2 is a diagram showing an operating force applying means 5 for driving the mechanism 4, and a cylinder head (not shown) of the internal combustion engine, which is attached across a front surface of a head cover and covers the front surface and the peripheral area of the assembly angle operating mechanism 4 and the operating force applying means 5. VT outside And it includes a cover, a.
[0015]
The drive ring 3 is formed in a substantially disk shape having a stepped insertion hole 6, and the insertion hole 6 is rotated by a driven shaft member 7 (driven rotation body) coupled to the front end of the camshaft 1. Assembled as possible. As shown in FIG. 2, three radial grooves 8 (radial guides) having parallel side walls facing each other are formed on the front surface of the drive ring 3 (the surface opposite to the camshaft 1). It is formed substantially along the radial direction.
[0016]
As shown in FIG. 1, the driven shaft member 7 has an enlarged-diameter portion formed on an outer periphery of a base portion that abuts on a front end portion of the camshaft 1, and has an outer peripheral surface on a front side of the enlarged diameter portion. Three levers 9 projecting radially are integrally formed and connected to the camshaft 1 by bolts 10 penetrating the shaft core. A base end of a link 11 is pivotally connected to each lever 9 by a pin 12, and a column-shaped projection 13 slidably engaged with each of the radial grooves 8 is integrally formed at a distal end of each link 11. Is formed.
[0017]
Each link 11 is connected to the driven shaft member 7 via the pin 12 in a state where the protrusion 13 is engaged with the corresponding radial groove 8. When displaced along 8, the drive ring 3 and the driven shaft member 7 rotate relative to each other by the action of the link 11 in a direction and an angle corresponding to the displacement of the projection 13.
[0018]
A receiving hole 14 is formed at the distal end of each link 11 and opens forward in the axial direction. The receiving hole 14 has an engaging pin 16 that engages with a spiral groove 15 (a spiral guide) described later. And a coil spring 17 for urging the engagement pin 16 forward (toward the spiral groove 15). In the case of this embodiment, a movable guide portion that can be displaced in the radial direction is configured by the protrusion 13 at the tip of the link 11, the engagement pin 16, the coil spring 17, and the like.
[0019]
On the other hand, an intermediate rotating body 18 having a disc-shaped flange wall 18 a is rotatably supported via a bearing 19 on the front side of the driven shaft member 7 from the position where the lever 9 protrudes. The above-mentioned spiral groove 15 having a semicircular cross section is formed on the rear surface side of the flange wall 18a of the intermediate rotating body 18, and the engaging pin 16 at the tip of each of the links 11 is rotatable in the spiral groove 15. Guide engagement. The spiral of the spiral groove 15 is formed so that its diameter gradually decreases along the engine rotation direction R. Therefore, when the intermediate rotating body 18 relatively rotates in the delay direction with respect to the drive ring 3 in a state where the engaging pin 16 at the tip of each link 11 is engaged with the spiral groove 15, the tip of the link 11 is While being guided by the spiral shape of the spiral groove 15 and moving inward in the radial direction, conversely, when the intermediate rotating body 18 is relatively displaced in the advancing direction, it moves outward in the radial direction.
[0020]
Reference numerals 48 and 49 in the figure denote projections and stoppers that come into contact with each other when the drive ring 3 and the intermediate rotating body 18 rotate relative to each other by more than a set angle, thereby restricting the rotation of the two.
[0021]
The assembling angle operating mechanism 4 includes the radial groove 8, the link 11, the protrusion 13, the engaging pin 16, the lever 9, the intermediate rotating body 18, the spiral groove 15, and the like of the drive ring 3 described above. When the relative rotation operation force with respect to the camshaft 1 is input from the operation force applying means 5 to the intermediate rotating body 18, the operation angle operation mechanism 4 applies the operation force to the spiral groove 15 and the engagement pin 16. The distal end of the link 11 is displaced in the radial direction through the engaging portion, and at this time, relative rotational power is transmitted to the drive ring 3 and the driven shaft member 7 by the action of the link 11 and the lever 9.
[0022]
On the other hand, the operating force applying means 5 includes a mainspring spring 47 serving as a rotation urging spring for urging the intermediate rotating body 18 in the engine rotation direction R with respect to the driving ring 3 and an intermediate rotating body 18 with respect to the driving ring 3. A hysteresis brake 20 as an operating actuator for biasing the engine in a direction opposite to the engine rotation direction R, and by appropriately controlling the braking force of the hysteresis brake 20 in accordance with the operating state of the internal combustion engine, The rotation of the drive ring 18 relative to the drive ring 3 or the rotation of the drive ring 3 is maintained.
[0023]
The mainspring spring 47 has an outer peripheral end coupled to the cylindrical wall 21 extending from the drive ring 3, and an inner peripheral end coupled to the cylindrical base 18 b of the intermediate rotating body 18. As shown in FIGS. 4 and 5, the radially inner end 47a of the mainspring 47 is expanded in the initial state, and the radially inner end 47a is rotated in the radially reduced direction as shown by a broken line in FIG. As a result, a rotational urging force is generated. The spring 47 is formed by winding a long spring steel in a spiral shape. Both ends of the spring 47 are formed in an arc-shaped cross section as shown in FIG. Have been.
[0024]
A sealing wall 50 is integrally connected to the end face of the intermediate rotating body 18 opposite to the camshaft 1, and the outer peripheral surface of the sealing wall 50 is slidably in close contact with the inner surface of the cylindrical wall 21. ing. Although a sealing member 51 is interposed between the sealing wall 50 and the cylindrical wall 21, the sealing of the sealing member 51 is not perfect and allows a small amount of liquid to leak. ing. A space between the flange wall 18a of the intermediate rotating body 18 and the sealing wall 50 on the inner peripheral side of the cylindrical wall 21 is a lubricating liquid chamber 52, and the mainspring 47 is provided in the lubricating liquid chamber 52. It is housed and arranged inside. The lubricating fluid supplied to the lubricating fluid chamber 52 from the bearing (not shown) of the engine block into the housing space 53 of the mounting angle operating mechanism 4 through the camshaft 1 and the driven shaft member 7. Is introduced through the outer peripheral side of the intermediate rotating body 18. However, the supplied lubricating liquid does not always stay in the lubricating liquid chamber 52, and is returned from the lubricating liquid chamber 52 to an oil pan (not shown) through the gap of the seal member 51.
[0025]
The hysteresis brake 20 is attached to a VTC cover which is a non-rotating member, and is provided on a magnetic induction member 22 having a pair of circumferentially opposed surfaces facing each other with a substantially cylindrical gap therebetween, and provided on each of the opposed surfaces. An inner coil 23, an outer pole 24, an electromagnetic coil 25 attached to the magnetic induction member 22 and generating a magnetic field between the inner pole 23 and the outer pole 24; And a cylindrical hysteresis ring 26 inserted and arranged in a non-contact state with the intermediate rotating body 18 via a connecting pin 54 and a rubber bush 38 with the outer peripheral end integrally connected to the hysteresis ring 26. And an annular plate 33, and the electromagnetic coil 25 is controlled to be energized by a controller (not shown).
[0026]
The inner pole teeth 23 and the outer pole teeth 24 of the magnetic guide member 22 each have a plurality of pole tooth elements extending along the axial direction. The pole teeth elements of the both pole teeth 23 and 24 are respectively arranged along the circumferential direction, and the pole tooth elements of the pole teeth 23 and 24 are mutually offset in the circumferential direction. Therefore, when the electromagnetic coil 25 is energized, a magnetic field is generated between the two pole teeth 23 and 24 toward the partner pole tooth element having an offset positional relationship.
[0027]
The hysteresis ring 20 is made of a hysteresis material having a magnetic hysteresis characteristic. When a magnetic field is generated between the inner pole teeth 23 and the outer pole teeth 24 during rotation of the ring 20, the direction of the magnetic field and the inside of the hysteresis ring 20 are changed. A deviation is caused in the direction of the magnetic flux. The hysteresis brake 20 generates a braking force due to this shift. The annular plate 33 is integrally connected to a shaft member 36 supported on the inner peripheral surface of the magnetic guide member 22 via bearings 34 and 35. Therefore, the hysteresis ring 20 is rotatably supported by the magnetic guide member 22 via the annular plate 33 and the shaft member 36.
[0028]
Since the valve timing control device is configured as described above, the excitation of the electromagnetic coil 25 of the hysteresis brake 20 is turned off at the time of starting the internal combustion engine or at the time of idling, whereby the intermediate rotation is performed by the force of the mainspring spring 47. The body 18 is rotated to the maximum in the engine rotation direction R with respect to the drive ring 3 (see FIG. 2). As a result, the rotational phase of the crankshaft and the camshaft 1 (opening / closing timing of the engine valve) is maintained at the most retarded side, so that engine rotation is stabilized and fuel efficiency is improved.
[0029]
Then, from this state, the operation of the engine shifts to the normal operation, and when a command to change the rotation phase to the most advanced side is issued from a controller (not shown), the excitation of the electromagnetic coil 25 of the hysteresis brake 20 is turned on. The braking force against the mainspring spring 47 is transmitted from the annular plate 33 to the intermediate rotating body 18 via the connecting pin 54 and the rubber bush 38. As a result, the intermediate rotating body 18 rotates in the opposite direction with respect to the drive ring 3, whereby the engaging pin 16 at the tip of the link 11 is guided to the spiral groove 15, and the tip of the link 11 is inserted into the radial groove 8. 3, the assembling angle between the drive ring 3 and the driven shaft member 7 is changed to the most advanced angle side by the action of the link 11, as shown in FIG. As a result, the rotation phases of the crankshaft and the camshaft 1 are changed to the most advanced angle side, thereby increasing the output of the engine.
[0030]
When a command is issued from the controller to change the rotation phase to the most retarded side from this state, the excitation of the electromagnetic coil 25 of the hysteresis brake 20 is turned off, and the force of the mainspring spring 47 is again applied to the intermediate rotating body. 18 is rotated in the engine rotation direction R. Then, the guide pin 16 guided by the spiral groove 15 causes the link 11 to swing in the opposite direction to the above, and as a result of the action of the link 11, the assembling angle between the drive ring 3 and the driven shaft member 7 is reduced, as shown in FIG. It is changed to the retard side again.
[0031]
The rotation phase of the crankshaft and the camshaft 1 by this valve timing control device is not limited to the two phases of the most retarded angle and the most advanced angle described above, but may be any value determined by controlling the braking force of the hysteresis brake 20. The phase can be changed and the phase can be maintained by the balance between the force of the mainspring 47 and the braking force of the hysteresis brake 20.
[0032]
In this valve timing control device, the mainspring 47 that urges the intermediate rotating body 18 in the retarding direction comes into line contact between adjacent surfaces when deformed by receiving a load. Since the spring 47 is immersed in the lubricating liquid in the chamber 52, the adjacent surface of the spring 47 is constantly lubricated with the lubricating liquid. Therefore, in the case of this device, there is no problem such as generation of abnormal noise due to line contact of the mainspring spring 47 and wear or deterioration of the adjacent surface. In addition, since the lubricating fluid in the lubricating fluid chamber 52 also exerts a damper function when the mainspring spring 47 is operated, the damper function causes the alternating torque of the camshaft 1 (variable torque due to the spring force of the valve spring and the profile of the drive cam). Can be reduced.
[0033]
In the case of this device, the mainspring spring 47 is accommodated in a lubricating liquid chamber 52 separated by the cylindrical wall 21 of the drive ring 3, the flange wall 18 a of the intermediate rotating body 18, and the sealing wall 50. Therefore, the axial displacement of the mainspring 47 can be reliably restricted by the flange wall 18a and the sealing wall 50, and the cylindrical wall 21 can restrict excessive expansion deformation of the mainspring 47. Therefore, the spring characteristics of the mainspring 47 can be stably maintained. Further, since the inner wall of the lubricating liquid chamber 52 restricts the spring spring 47 from being deformed more than necessary, it is not necessary to secure the lubricating liquid chamber 52 larger than necessary, and the liquid chamber 52 can be downsized. is there.
[0034]
Further, in the case of this embodiment, since the side end of the mainspring 47 is formed in an arc-shaped cross section to eliminate the edge portion, the edge portion comes into contact with other portions of the mainspring 47 and surrounding members. Wear and damage of the mainspring 47 can be prevented. Therefore, in a device employing such a mainspring 47, the durability of the mainspring 47 can be improved, and the expected performance of the device can be maintained for a long period of time.
[0035]
Further, in this embodiment, as the assembling angle operating mechanism 4, the base end of the link 11 whose leading end is guided and engaged with the radial groove 8 of the drive ring 3 is pivotally connected to the lever 9 of the driven shaft member 7. Although the structure in which the engagement pin 16 held at the distal end of the link 11 is guided and engaged with the spiral groove 15 of the intermediate rotating body 18 has been adopted, the assembly angle operating mechanism 4 is provided with a driving rotating body (drive ring 3). Other structures can also be adopted as long as the driven rotating body (the driven shaft member 7) can be relatively rotated. However, when the rotation of the intermediate rotor 18 is amplified and converted into relative rotation between the drive ring 3 and the driven shaft member 7 as in this embodiment, the rotation amount (rotation angle) of the intermediate rotor 18 during operation ) Is large, the amount of deformation of the mainspring 47 is large, and the line contact of the mainspring 47 is also large. Therefore, the structure according to the present invention in which the mainspring 47 is immersed in the lubricating liquid is particularly effective.
[0036]
Further, in this embodiment, the hysteresis brake 20 is employed as an operation actuator for applying a force against the force of the mainspring 47, but another electromagnetic brake or a hydraulic actuator may be employed as the operation actuator. . However, when an electromagnetic actuator such as the hysteresis brake 20 of this embodiment is employed, a hydraulic damper effect as in the case of employing a hydraulic actuator cannot be obtained, and the influence of the inertial force of each part at the time of operation cannot be obtained. As a result, line contact due to deformation of the mainspring 47 is more likely to occur. Therefore, when such an electromagnetic actuator is employed, the structure according to this application is more effective.
[0037]
Further, it is possible to seal the lubricating liquid in the lubricating liquid chamber 52 in a hermetically sealed state and immerse the mainspring 47 in the lubricating liquid. However, as in this embodiment, the lubricating liquid is circulated in the lubricating liquid chamber 52. In the case of supplying, there is an advantage that deterioration of the lubricating liquid is prevented and stable lubricating performance can be maintained for a long period of time.
[0038]
The embodiments of the invention of this application are not limited to those described above. For example, in the above embodiments, the mainspring spring was used as the rotation urging spring. Spiral springs, torsion springs, and the like can also be used as long as they come into sliding contact.
[0039]
Next, inventions other than those described in the claims that can be grasped from the above-described embodiments will be described below together with their operational effects.
[0040]
4. The valve timing control device for an internal combustion engine according to claim 1, wherein an electromagnetic actuator is used as the operation actuator.
[0041]
Since the electromagnetic actuator does not use a hydraulic pressure, each part operates without receiving a damper effect due to the hydraulic pressure. At this time, the rotational biasing spring is largely deformed by the influence of the inertial force and line contact easily occurs. Therefore, in such a device, by immersing the rotation urging spring in the lubricating liquid, it is possible to effectively reduce the adverse effect due to the line contact.
[0042]
(B) The assembly angle operation mechanism for operating the assembly angle between the driving rotating body and the driven rotating body includes:
A radial guide provided so as to be rotatable relative to the driving rotary body and the driven rotary body, an intermediate rotary body having a spiral guide on a surface facing the radial guide, and the radial guide and the spiral guide A movable guide portion displaceably engaged with the guide;
A link that swingably connects a portion separated from the rotation center of the other of the driving rotator and the driven rotator and the movable guide portion,
The rotational operating force of the intermediate rotating body is amplified by an engaging portion between the spiral guide and the movable guide, and is converted into an assembling angle operating force of the driving rotating body and the driven rotating body. 3. A valve timing control device for an internal combustion engine according to any one of (a) and (b).
[0043]
In such a device, since the rotation angle of the intermediate rotating body at the time of the assembling angle operation is increased, the rotation urging spring is easily deformed by that amount, and the line contact between adjacent portions of the spring is easily generated. . Therefore, in such an apparatus, the adverse effects caused by line contact can be effectively eliminated.
[0044]
(C) The rotation biasing spring is constituted by a mainspring spring, and the mainspring spring is disposed between the intermediate rotator and a sealing plate disposed on the axial side of the intermediate rotator. The valve timing control device for an internal combustion engine according to (b).
[0045]
In this case, axial displacement of the mainspring can be reliably prevented by the intermediate rotating body and the sealing plate. Therefore, the spring characteristics of the mainspring are always stable.
[0046]
(D) The internal combustion engine according to (c), wherein the mainspring is restricted in displacement on the outer peripheral side by a cylindrical wall provided integrally with one of the driving rotary member and the driven rotary member. Valve timing control device.
[0047]
In this case, an excessive displacement of the mainspring in the radially expanding direction can be reliably restricted by the cylindrical wall, and a decrease in the spring characteristics of the mainspring can be prevented.
[0048]
(E) The valve timing control device for an internal combustion engine according to any one of (1) to (3), wherein a lubricating liquid for immersing the rotation urging spring is circulated.
[0049]
In this case, deterioration of the lubricating liquid does not occur, and stable lubricating performance can be obtained for a long period of time.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing an embodiment of the present invention.
FIG. 2 is an exemplary sectional view of the same embodiment taken along line AA of FIG. 1;
FIG. 3 is an exemplary sectional view corresponding to FIG. 2 showing an operation state of the embodiment;
FIG. 4 is an exemplary perspective view of a mainspring showing the embodiment;
FIG. 5 is a front view of the mainspring showing the embodiment.
FIG. 6 is an enlarged perspective view of the mainspring showing the embodiment.
[Explanation of symbols]
1 camshaft 3 drive ring (drive rotary body)
7: driven shaft member (driven rotating body)
20: Hysteresis brake (operation actuator)
47 ... Spring spring 52 ... Lubricant chamber

Claims (3)

A driving rotor that is driven to rotate by a crankshaft of an internal combustion engine, a driven rotor that is a camshaft or a separate member coupled to the shaft, and an assembling angle of the driving rotor and the driven rotor in a retard direction Or a spiral or coil-shaped rotation urging spring that urges in the advance direction, and an operation of applying a rotational operation force to the driving rotator and the driven rotator that opposes the rotation urging spring. An actuator, and a valve timing control device for an internal combustion engine comprising:
A valve timing control device for an internal combustion engine, wherein the rotation urging spring is immersed in a lubricating liquid. The valve timing control device for an internal combustion engine according to claim 1, wherein the rotation urging spring is housed in a lubricating liquid chamber, and an excessive displacement of the rotation urging spring is regulated by an inner wall of the liquid chamber. 3. The valve timing control device for an internal combustion engine according to claim 1, wherein the rotation urging spring is formed of a mainspring, and a side end of the mainspring is formed in an arc-shaped cross section.

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