JP4386823B2 - Phase variable device for automobile engine - Google Patents

Description

  According to the present invention, helical spline engagement is performed on the annular outer cylinder portion to which the driving force of the crankshaft is transmitted and the driven annular inner cylinder portion extending to the camshaft, respectively, and the axial movement is applied to the outer cylinder portion. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a phase varying device in an automobile engine having an intermediate member that changes the phase of an inner cylinder (changes the opening / closing timing of a valve by changing the rotational phase of a camshaft), particularly between the outer cylinder and the inner cylinder. The present invention relates to a phase varying device in an automobile engine configured to reduce a hitting sound in a helical spline engaging portion by interposing a friction torque adding member for increasing a sliding friction torque in the relative sliding portion.

  For example, Patent Document 1 is known as this type of phase variable device. As shown in FIG. 13, a coaxial camshaft 2 is disposed on the inner peripheral side of the sprocket 1 to which the driving force of the crankshaft of the engine is transmitted, and between the sprocket 1 and the camshaft 2, both An intermediate member 3 that engages helical splines with 1 and 2 and moves in the axial direction to change the phase between the two 1 and 2 is interposed. The rotating drum 5 is arranged so that the braking force is applied by the electromagnetic brake 4 fixed to the engine case 9 and the spring 6 wound up between the rotating drum 5 and the sprocket 1 is disposed. The structure is arranged in the radial direction. Reference numerals 3 a and 3 b denote inner and outer helical spline engaging portions, and reference numeral 5 a denotes a square screw portion of the rotary drum 5.

  Then, by the ON / OFF control of the electromagnetic brake 4, the braking force of the electromagnetic brake 4 is transmitted to the rotary drum 5, and the intermediate member 3 moves forward while being rotated by the square screw portions 3c and 5a (moves in the right direction in FIG. 12). The phase between the sprocket 1 and the camshaft 2 is changed by the helical spline engaging portions 3a and 3b. In particular, since the reverse helical spline engaging portions 3a and 3b are provided on the inner and outer peripheral surfaces of the intermediate member 3 interposed between the sprocket 1 and the camshaft 2, the sprocket 1 and the movement amount in the axial direction of the intermediate member 3 The phase between the camshafts 2 can be changed greatly.

  In addition, a spring member 7 and a friction plate 8 are interposed between the sprocket 1 side and the camshaft 2 side to increase the relative sliding torque between the sprocket 1 side and the camshaft 2, and the helical spline engaging portions 3 a and 3 b. The reduction of the rattling noise is achieved.

That is, torque fluctuation occurs in the camshaft 2 every time the valve is opened and closed, and rotation irregularity occurs in the camshaft 2. Since the helical spline engaging portions 3a and 3b are provided with a gap corresponding to backlash, teeth in the helical spline engaging portions 3a and 3b are caused by a sudden change in the rotational speed between the sprocket 1 and the crankshaft 2. There is a risk that a metal sound such as cuts, cuts, cuts, etc. may be generated when the blades collide at a rapid speed, but a spring member 7 and a friction plate 8 are interposed between the sprocket 1 side and the camshaft 2 side as a friction torque adding member. Thus, by increasing the relative sliding torque between the sprocket 1 and the camshaft 2, the collision speed between the teeth at the helical spline engaging portions 3a and 3b is reduced, and the collision noise is reduced.
JP 2001-168288 A

  However, in the above-described prior art (Patent Document 1), the sliding contact surface of the friction plate 8 made of paper impregnated with resin is worn away, and the following problems have been raised.

  First, due to wear of the sliding contact surface of the friction plate 8, the interposed space of the spring member 7 is expanded, and the spring biasing force of the spring member 7 acting on the sliding contact surface of the friction plate 8 is reduced. For this reason, the relative sliding torque between the sprocket 1 side and the camshaft 2 decreases, and it cannot be said that the effect of reducing the rattling noise in the helical spline engaging portions 3a and 3b is sufficient.

  Secondly, as a member for increasing the relative sliding torque between the sprocket 1 side and the camshaft 2, two members of the spring member 7 and the friction plate 8 are necessary, and the number of parts is large accordingly. Further, in order to maintain the effect of reducing the rattling noise in the helical spline engaging portions 3a and 3b, the friction plate 8 may be periodically replaced before being worn, but it is very troublesome.

  The present invention has been made in view of the above-described problems of the prior art. The first object of the present invention is to form a sprocket-side annular outer cylindrical portion to which a crankshaft driving force is transmitted and a camshaft-side annular shape. An object of the present invention is to provide a phase varying device in an automobile engine that can be used continuously for a long time without generating a hitting sound in a helical spline engaging portion of an intermediate member interposed between inner cylinder portions. A second object of the present invention is to provide a phase variable device in an automobile engine having a simple structure.

In order to achieve the first and second objects, in the phase varying device for an automobile engine according to claim 1, an annular outer cylinder portion to which a driving force of a crankshaft is transmitted, and the outer cylinder portion Is arranged between the outer cylinder part and the inner cylinder part by being engaged with helical splines in the outer cylindrical part and the inner cylinder part, respectively. And an intermediate member that changes the phase of the inner cylinder part relative to the outer cylinder part,
A flange is provided on the outer peripheral surface of the inner cylindrical portion, a flange engaging groove for engaging the flange is provided on the inner peripheral surface of the outer cylindrical portion, and an axial direction is provided on one side of the flange. is interposed a spring member extending is the other side of the flange perpendicular to the axis of the inner cylinder part, the flange engaging the groove orthogonal to the axis of the inner cylinder part opposite thereto In the phase varying device in an automobile engine in which the side surface is in sliding contact, the sliding friction torque in the sliding contact portion is increased, and the occurrence of hitting sound in the helical spline engaging portion is reduced.
At least one of the opposite side surfaces constituting the sliding contact portion is configured to have a convex shape on the inner diameter side that is inclined with respect to a plane orthogonal to the axis of the inner cylinder portion .

In order to achieve the first object, in the phase varying device for an automobile engine according to claim 2, an annular outer cylindrical portion to which a driving force of a crankshaft is transmitted is disposed coaxially with the outer cylindrical portion. And a driven annular inner tube portion extending to the camshaft, helical spline engagement with the outer tube portion and the inner tube portion, respectively, disposed between the outer tube portion and the inner tube portion, and moving in the axial direction. An intermediate member that changes the phase of the inner cylinder part with respect to the outer cylinder part,
A flange is provided on the outer peripheral surface of the inner cylindrical portion, a flange engaging groove for engaging the flange is provided on the inner peripheral surface of the outer cylindrical portion, and an axial direction is provided on one side of the flange. The extending spring member has a metal annular friction plate interposed on the other side surface thereof , and the other side surface of the flange perpendicular to the axis of the inner cylinder portion and the inner cylinder facing the other side surface sliding contact with the side surface of the flange engaging grooves orthogonal to the axis of the section is through the metal annular friction plates having a side orthogonal to the axis of the inner cylinder part, the sliding friction at the sliding contact portion In the phase varying device in an automobile engine in which the torque is increased to reduce the occurrence of hitting sound in the helical spline engaging portion,
At least one of the opposing side surfaces constituting the sliding contact portion is formed in a tapered shape having a convex on the inner diameter side that is inclined with respect to a plane perpendicular to the axis of the inner cylinder portion .

  (Operation) In the phase varying device, the outer cylinder portion, the intermediate member, and the inner cylinder portion are configured to rotate integrally, and the outer cylinder portion and the camshaft to which the driving force of the crankshaft of the engine is transmitted. The inner cylinder portion on the side rotates in synchronization, but when the intermediate member is moved in the axial direction by the electromagnetic brake means or the hydraulic drive means, the phase between the sprocket and the camshaft is changed by the helical spline engaging portion.

  Then, torque fluctuation occurs in the camshaft every time the valve is opened and closed, and rotation irregularity occurs in the camshaft. That is, immediately after the cam in the valve mechanism moves over the valve stem, the relative rotational speed between the outer cylinder part and the inner cylinder part changes suddenly, for example, the rotational speed of the camshaft varies by the amount corresponding to the return spring force of the valve. At this time, the tooth portions collide with each other in the helical spline engaging portion between the intermediate member and the outer cylindrical portion and the inner cylindrical portion, but the intermediate member is interposed between the side surface of the flange and the side surface of the flange engaging groove facing this. The sliding friction at the sliding contact portion between the other side surface of the flange and the side surface of the flange engaging groove opposed to the other side, which is resistance to relative rotation between the outer cylindrical portion and the inner cylindrical portion, by the spring biasing force of the spring member Since the torque (sliding friction torque in the sliding contact portion between the side surface of the flange and the friction plate and the side surface of the flange engaging groove) is increased, the helical member between the intermediate member and the outer cylinder portion and the inner cylinder portion is increased. The collision speed between the tooth portions in the spline engaging portion is reduced, and the occurrence of rattling noise is suppressed.

  If the amount of increase in the sliding friction torque at the sliding contact portion is too large, the time until the phase changes between the outer tube portion and the inner tube portion (response time) increases, and the phase variable response of the phase variable device. Therefore, it is not desirable to increase the sliding friction torque so much in terms of response time. Therefore, the sliding friction torque of the relative sliding part between the outer cylinder part and the inner cylinder part is, for example, -20% or more of the average cam torque from the viewpoint of reducing the hitting sound, and from the viewpoint of a good response time, For example, it is desirable to be + 10% or less of the average cam torque. And the sliding friction torque of the relative sliding part between an outer cylinder part and an inner cylinder part is set to the above-mentioned range by adjusting the spring force of a spring member.

  Further, since both the flange (inner cylinder part in which the flange is formed) and the flange engagement groove (outer cylinder part in which the flange is formed) are made of metal (in claim 2, the friction plate is also made of metal). The amount of wear in the sliding contact portion between the side surface of the flange and the side surface of the flange engaging groove (in claim 2, the amount of wear in the sliding contact portion between the side surface of the flange and the side surface of the friction plate and the flange engaging groove) The amount of wear of a conventional friction plate made of paper impregnated with is significantly less. That is, since the sliding contact portion (metal) is hard to be worn out, the distance between the flange side surface and the groove side surface where the spring member is interposed hardly changes (expands), and the spring biasing force acting on the sliding contact portion Will not change. For this reason, there is no change in the sliding friction torque in the sliding contact portion, and the occurrence of rattling noise due to the reduction in the collision speed between the tooth portions in the helical spline engaging portion between the intermediate member and the outer cylindrical portion and the inner cylindrical portion is suppressed. There is no change in action.

  Further, since the sliding contact portion is hard to be worn away, the metal powder generated by the wear is reduced, the contamination of the engine oil is reduced accordingly, and the frequency of oil replacement may be reduced.

  In addition, if the device is used for a long period of time, the sliding contact parts, which are difficult to wear away from each other, will be worn away. The dynamic friction coefficient μ decreases, and the sliding friction torque decreases. Further, the wear of the sliding contact portion increases the distance between the flange side surface where the spring member is interposed and the groove side surface, the spring biasing force acting on the sliding contact portion is reduced, and the sliding friction torque is reduced.

  However, when the sliding contact portion wears out, the area of the sliding contact portion is expanded radially outward along the tapered sliding contact surface, and the sliding friction torque at the sliding contact portion increases.

  In this way, even if the sliding contact portion is worn out due to long-term use of the apparatus, the increase in the sliding friction torque at the sliding contact portion due to the area of the sliding contact portion being expanded radially outward is reduced to the sliding contact portion ( The decrease in the sliding friction torque in the sliding contact portion due to the smoothing of the sliding contact surface and the decrease in the spring biasing force acting on the sliding contact portion is compensated for, and a significant decrease in the sliding friction torque in the sliding contact portion is suppressed.

  Further, according to the first aspect, the number of parts can be reduced because the friction plate as in the prior art is unnecessary.

  According to a third aspect of the present invention, in the phase varying device for an automobile engine according to the first or second aspect, the spring member is constituted by a disc spring laminated body in which a plurality of disc springs are laminated.

  (Action) There are disc springs, coil springs, leaf springs, etc. as spring members. Since the coil springs have a linear load-elongation characteristic, friction torque (outer cylinder part and inner cylinder) applied to the sliding contact part. The adjustment of the sliding friction torque of the relative sliding part between the parts is difficult, and further, when the sliding contact part wears out and the space between the spring members increases, the spring biasing force of the coil spring is also greatly reduced. The friction torque acting on the sliding contact portion (sliding friction torque at the relative sliding portion between the outer tube portion and the inner tube portion) is also significantly reduced. On the other hand, when a disc spring laminated body in which a plurality of disc springs are laminated as a spring member, the load-elongation characteristic has a substantially constant region (shows a characteristic that becomes an almost constant load with respect to elongation). Thus, it is easy to adjust the friction torque applied to the sliding contact portion (sliding friction torque at the relative sliding portion between the outer tube portion and the inner tube portion). Furthermore, even if the sliding contact portion wears out and the space between the spring members increases, the spring biasing force of the disc spring laminate does not significantly decrease, and the friction torque acting on the sliding contact portion (the outer tube portion and the inner tube) The decrease in the friction torque at the relative sliding part of the part is slight.

  That is, even if the sliding contact portion wears out, the decrease in the spring urging force acting on the sliding contact portion is small, and the sliding friction torque at the sliding contact portion is also small.

According to a fourth aspect of the present invention, in the phase varying device for an automobile engine according to any one of the first to third aspects, a flat spacer is provided between the spring member, the side surface of the flange, and the side surface of the flange engaging groove. I tried to intervene.
(Operation) In order to prevent wear of only a part of the flange member and the flange engaging groove on which the spring member is interposed, which is directly contacted by the spring member, the interposed surface of the spring member is generally polished. However, the surface smoothing process can be omitted by interposing a spring member via a spacer.

According to a fifth aspect of the present invention, in the phase varying device for an automobile engine according to any one of the first to fourth aspects, the inner cylinder portion communicates with an oil passage of a camshaft and opens to a flange engaging groove. An introduction hole is provided, and the outer cylinder portion is provided with an oil discharge hole that communicates with the flange engaging groove and opens to the outside, and at least one of the opposing side surfaces constituting the sliding contact portion is radially provided. An extending oil groove was provided.
(Operation) New engine oil in the oil passage of the camshaft is introduced into the flange engagement groove through the oil introduction hole, and the engine oil in the flange engagement groove is outside the outer cylinder portion through the oil discharge hole. However, the oil is evenly guided to the sliding contact surface via the oil groove provided on the sliding contact surface that constitutes the sliding contact portion, so that the sliding friction torque on the sliding contact surface changes suddenly and heat is generated. Is suppressed. Moreover, the metal powder generated by the abrasion of the sliding contact portion (sliding contact surface) is discharged to the outside through radially extending oil grooves and oil discharge holes.

  In particular, when the oil groove is provided radially on the side surface of the flange engagement groove in claim 1, an annular second groove connected to the oil discharge hole is provided outside the side surface of the flange engagement groove, and the flange engagement is performed. Increase the circulation of engine oil between the inside and outside of the groove, maintain proper friction torque at the sliding contact part and suppress heat generation, and enhance the function of discharging metal powder generated at the sliding contact part outside the outer cylinder part desirable.

  As is clear from the above description, according to the phase varying device for an automobile engine according to claim 1, even if the sliding contact portion between the flange and the flange engaging groove is worn out by long-term use, the sliding contact portion can be provided. Since the sliding friction torque is kept substantially constant without significantly decreasing, the apparatus can be used for a long time without replacing parts. Further, since the friction plate is unnecessary, the number of parts is small, and the apparatus structure is simplified accordingly.

  According to the phase varying device for an automobile engine according to claim 2, even if the sliding contact portion between the flange, the friction material, and the flange engaging groove is worn out by long-term use, the sliding friction torque at the sliding contact portion is greatly increased. Since it is held substantially constant without deteriorating, the apparatus can be used for a long time without replacing parts.

  According to the third aspect, even if the sliding contact portion between the flange and the flange engaging groove is worn out due to long-term use, the sliding friction torque at the sliding contact portion is held constant with almost no decrease. The device can be used for a longer period of time without doing so.

  According to the fourth aspect, since the surface smoothing process on the spring member interposed surface in the outer cylinder part or the inner cylinder part can be omitted, the apparatus can be provided at a lower cost.

  According to the fifth aspect, the oil circulation between the inside and outside of the flange engaging groove becomes active, and the metal powder generated by the abrasion of the sliding contact portion is surely discharged out of the outer cylinder portion. There is no sudden change in sliding friction torque or excessive heat generation, and the occurrence of impact hitting between teeth in the helical spline engaging part between the intermediate member and the outer cylinder part and the inner cylinder part is reliably suppressed over a long period of time, and the response A phase variable device with good performance is provided.

  Next, embodiments of the present invention will be described based on examples.

  1 to 5 show a first embodiment of a phase varying device according to the present invention. FIG. 1 is a longitudinal sectional view of a phase varying device in an automobile engine according to the first embodiment of the present invention. Is a perspective view showing the internal structure of the device, FIG. 3 is a characteristic diagram showing the relationship between the friction torque between the outer tube portion (sprocket) and the inner tube portion (camshaft) of the device, the hitting sound, and the response time. 4 is an enlarged cross-sectional view of the periphery of the sliding contact surface between the side surface of the flange and the flange engaging groove, and FIG. 5 is a perspective view showing an oil groove provided on the sliding contact surface on the side surface side of the flange engaging groove.

  In these figures, the phase variable device shown in this embodiment is used in a form assembled and integrated with an engine, and the rotation of the crankshaft is controlled so that the intake and exhaust valves open and close in synchronization with the rotation of the crankshaft. And an opening / closing timing of the intake / exhaust valve of the engine depending on the operating state such as the engine load and the rotational speed. An outer cylindrical portion 10, an annular inner cylindrical portion 20 on the driven side, which is arranged coaxially with the outer cylindrical portion 10 and is rotatable relative to the outer cylindrical portion 10, and which is integrally connected with the camshaft 2; 10 and the inner cylinder part 20 are respectively engaged by helical splines, interposed between the outer cylinder part 10 and the inner cylinder part 20, and moved in the axial direction to change the phase of the inner cylinder part 20 with respect to the outer cylinder part 10. 30 and the inner cylinder 0 provided on the cam shaft 2 non-disposed side of, and is configured to include an electromagnetic brake means 40 for moving the intermediate member 30 in the axial direction.

The outer cylinder portion 10 is fixed to the sprocket 12 provided with a ring-shaped convex portion 12a (see FIG. 4) on the inner peripheral edge, and screwed so as to be in close contact with the side surface of the sprocket 12, and cooperates with the convex portion 12a to form a flange While defining the engaging groove 13, the inner peripheral side is comprised from the intermediate member 30 and the spline case 16 which carries out a spline engagement. The rotation of the crankshaft of the engine is transmitted to the sprocket 12 via the chain C. Reference numeral 11 denotes a fastening screw that fixes and integrates the sprocket 12 and the spline case 16. The outer cylinder portion 10 is configured by the sprocket 12 and the spline case 16, so that the flange engagement groove 13 can be easily formed. 10 (spline case 16) The female helical spline 17 can be easily formed on the inner peripheral surface.

  Reference numeral 12b is a hole through which the fastening screws 11 provided at equal intervals in the circumferential direction are inserted. The holes 12b are long holes in the circumferential direction and will be described in detail later. It functions as an oil discharge hole H that discharges the engine oil introduced into the flange engagement groove 13 by the introduction hole 73b to the outside of the outer cylinder portion 10 (see FIG. 5).

  Reference numerals 32 and 33 are male and female helical splines provided on the inner and outer peripheral surfaces of the intermediate member 30, and reference numeral 23 is a male helical spline provided on the outer peripheral surface of the inner cylinder portion 20. The inner and outer splines 32 and 33 of the intermediate member 30 are reverse helical splines, and the phase of the inner cylinder portion 20 can be greatly changed with respect to the outer cylinder portion 10 by a slight movement of the intermediate member 30 in the axial direction. it can. Reference numeral 31 denotes a male thread portion formed on the outer peripheral surface of the intermediate member 30.

  The electromagnetic brake means 40 is rotatably supported on the inner cylinder portion 20 by the electromagnetic clutch 42 supported by the engine case 9 and the bearing 22, and the male screw portion 31 of the intermediate member 30 is screwed into the electromagnetic clutch. The rotating drum 44 to which the braking force of 42 is transmitted, and the torsion coil spring 46 interposed between the rotating drum 44 and the outer cylinder portion 10 in the axial direction are configured. Reference numeral 45 denotes a female square screw portion provided on the inner peripheral surface of the rotary drum 44, and the rotary drum 44 and the intermediate member 30 can be relatively rotated along the square screw portions 45 and 31 in the circumferential direction. That is, the intermediate member 30 moves in the axial direction while rotating along the square screw portions 45 and 31. Further, since the torsion coil spring 46 interposed between the rotating drum 44 and the outer cylinder portion 10 (spline case 16) is interposed in the axial direction, the entire phase variable device extends in the axial direction, but the radial direction. It is compact.

  Then, by controlling the ON / OFF of the electromagnetic clutch 42 and the energization amount to the electromagnetic clutch 42, the intermediate member 30 moves in the axial direction while rotating along the square screw portions 45, 31, thereby the outer cylinder. The phase of the part 10 and the inner cylinder part 20 changes, and the timing of opening and closing of the valve by the cam 2a of the camshaft 2 is adjusted. That is, before the electromagnetic clutch 42 is turned on, the electromagnetic clutch 42 is in the position indicated by the phantom line in FIG. 1, and a gap S is formed between the rotating drum 44 and the electromagnetic clutch 42. The cylinder part 20 rotates integrally with no phase difference. When the electromagnetic clutch 42 is turned on, the electromagnetic clutch 42 slides in the right direction in FIG. 1 and is attracted to the rotating drum 44, whereby a braking force transmitted from the electromagnetic clutch 42 acts on the rotating drum 44. Therefore, the intermediate member 30 moves forward (moves in the right direction in FIG. 1) by the square screw portions 31 and 45, and the inner cylinder portion 20 (camshaft 2) is moved by the inner and outer helical splines 32 and 33 of the intermediate member 30. The phase is changed by rotating with respect to (sprocket 12). The rotating drum 44 is held at a position where the transmitted braking force and the spring force of the torsion coil spring 46 are balanced (position where the inner cylinder portion 20 has a predetermined phase difference with respect to the outer cylinder portion 10).

  On the other hand, when the electromagnetic clutch 42 is turned OFF, the braking force is not transmitted to the rotating drum 44, so the intermediate member 30 on which only the spring force of the coil spring 46 acts is moved backward by the square screw portions 31 and 45 (in the left direction in FIG. 1). The inner cylinder part 20 (camshaft 2) rotates in the opposite direction to the electromagnetic clutch ON with respect to the outer cylinder part 10 (sprocket 12) during this time, and the phase difference is Disappear.

  Further, a flange 24 is provided around the outer peripheral surface of the inner cylinder portion 20 (sliding surface with the sprocket 12), while the inner peripheral surface of the outer cylinder portion 10 (a connected body of the sprocket 12 and the spline case 16) is provided. The flange engaging groove 13 with which the flange 24 engages is provided around, and as shown in an enlarged view in FIG. 4, the disc spring laminated body 51 is interposed between the side surface 24 a of the flange 24 and the side surface 13 a of the flange engaging groove 13. The frictional torque of the relative sliding part between the outer cylinder part 10 and the inner cylinder part 20 is increased, and the helical spline engaging parts 23 and 32 between the intermediate member 30 and the outer cylinder part 10 and the inner cylinder part 20 are increased. , 33 and 17, the occurrence of hitting sounds that the tooth portions collide with each other is suppressed.

  In other words, immediately after the valve stem in the valve operating mechanism gets over the cam 2a, the rotational speed of the camshaft 2 fluctuates by the amount corresponding to the return spring force of the valve shaft. The tooth portions collide with each other in the helical spline engaging portions 23, 32, 33, 17 between the intermediate member 30 and the outer cylindrical portion 10 and the inner cylindrical portion 20, but the relative relationship between the outer cylindrical portion 10 and the inner cylindrical portion 20 The relative rotation between the outer cylinder part 10 and the inner cylinder part 20 by the spring biasing force of the disc spring laminate 51 interposed between the sliding parts (between the side face 24a of the flange 24 and the side face 13a of the flange engaging groove 13). Since the sliding friction torque at the sliding contact portion (sliding contact surface A1, A2) between the side surface 24b of the flange 24 and the side surface 13b of the flange engaging groove 13 that acts as a resistance against movement increases, It takes the emission engaging portion 23,32,33,17 to reduce the collision speed of the tooth portions, occurrence of teeth hitting sound is suppressed.

  Further, the frictional force applied to the sliding contact portions (sliding contact surfaces A1, A2) between the side surface 24b of the flange 24 and the side surface 13b of the flange engaging groove 13 by the spring biasing force of the disc spring laminate 51 is a helical spline. Of course, the camshaft 2 can follow the rotation of the crankshaft without delay, and is variable in phase, as well as effective in reducing the generation of rattling noise caused by the collision between the teeth at the engaging portions 23, 32, 33, and 17. The response has been adjusted to a suitable value.

  That is, the disc spring laminated body 51 interposed on the side surface 24a side of the flange 24 is mainly for generating a compression force (elastic force), and is a disc spring laminated body 51 in which a plurality of disc springs are laminated. The load-elongation characteristic has a substantially constant region (indicating the characteristic that the load becomes substantially constant with respect to the elongation), but several types of disc spring laminates with slightly different load-elongation characteristics are prepared in advance. The slidable contact portion (sliding contact surface A1) between the side surface 24b of the flange 24 and the side surface 13b of the flange engaging groove 13 is replaced by replacing the disc spring laminate accommodated in a predetermined gap between the flange 24 and the flange engaging groove 13A. , A2) is adjusted. Then, by specifying (determining) the disc spring laminated body 51 accommodated in the flange engaging groove 13, it is possible to reduce generation of rattling noise due to collision between the tooth portions in the helical spline engaging portions 23, 32, 33, and 17. In addition, the camshaft 2 is added to the relative sliding portion between the outer tube portion 10 and the inner tube portion 20 so that the camshaft 2 can follow the rotation of the crankshaft without delay (to improve the response). The friction torque is adjusted.

  FIG. 3 shows the friction torque between the outer cylinder part 10 and the inner cylinder part 20 on the horizontal axis, which is necessary for the valve opening / closing control with respect to the vibration indicating the sound level of the spline engaging part and the change of the load acting on the engine. Response time (response time until the inner cylinder 20 rotates relative to the outer cylinder 10 when a braking force is applied to the outer cylinder 10 by the electromagnetic brake means 40 and a phase difference occurs) FIG. 5 is a diagram showing a friction torque / vibration characteristic A and a friction torque / response time characteristic B in an engine of a certain automobile.

  As can be seen from the friction torque / vibration characteristic A in this figure, when the friction torque at the sliding portion between the outer cylinder portion 10 and the inner cylinder portion 20 increases, the collision speed of the tooth portion at the spline engagement portion becomes slower. Since the magnitude (vibration) of the hitting sound naturally decreases, it is better that the friction torque is large. However, as can be seen from the friction torque / response time characteristic B, when the friction torque increases, the response time increases (response time becomes slow), so the friction torque cannot be increased so much. Therefore, specifically, for example, the relative magnitude between the outer cylinder portion 10 and the inner cylinder portion 20 is set so that the magnitude (vibration) of the hitting sound is 16 G or less and the response time is 0.3 seconds or less. The number of disc springs of the disc spring laminate 51 is adjusted so that the friction torque in the sliding portion is in the range of -20% to + 10% of the average cam torque (average value of torque acting on the camshaft by opening and closing the valve). To do.

  Further, as a spring member interposed between the side surface 24a of the flange 24 and the side surface 13a of the flange engaging groove 13, there are a coil spring, a leaf spring and the like in addition to the disc spring laminated body 51. Since the characteristic is linear, the friction torque applied to the press contact portion between the flange 24 and the flange engagement groove 13 cannot be adjusted, but is troublesome. Furthermore, the press contact between the flange 24 and the flange engagement groove 13 is also troublesome. When the distance between the side surface 24a of the flange 24 and the side surface 13a of the flange engaging groove 13 is increased, the spring biasing force of the coil spring is also greatly reduced, and the relative sliding portion between the outer cylinder portion and the inner cylinder portion is reduced. The friction torque is also significantly reduced. On the other hand, in the disc spring laminated body 51 in which a plurality of disc springs are laminated, the press contact portion between the flange 24 and the flange engaging groove 13 is worn away, and between the side surface 24a and the side surface 13a where the disc spring laminated body 51 is interposed. Even if the distance increases, the spring biasing force does not decrease greatly, so that the pressure contact force at the sliding contact portions (sliding contact surfaces A1 and A2) hardly decreases. Therefore, the relative sliding force between the outer cylindrical portion 10 and the inner cylindrical portion 20 is reduced. A decrease in friction torque in the moving portion is slight, and reduction of tooth hitting sound between the tooth portions in the spline engaging portions 23, 32, 33, and 17 functions effectively over a long period of time.

  Further, since both the flange 24 (inner cylinder portion 20 formed with) and the flange engagement groove (outer cylinder portion 10 formed with) are made of metal, the side surface 24b of the flange 24 and the flange engagement groove are formed. The amount of wear at the sliding contact portions (sliding contact surfaces A1, A2) between the 13 side surfaces 13b is significantly smaller than that of the conventional friction plate 8 made of paper impregnated with resin. That is, since the sliding contact portions (sliding contact surfaces A1, A2) are difficult to wear, the distance between the flange side surface 24a on which the disc spring laminated body 51 is interposed and the groove side surface 13a hardly changes (does not expand). The spring biasing force acting on the sliding contact portions (sliding contact surfaces A1, A2) does not change. For this reason, unless it is used for a long time, there is no change in the sliding friction torque at the sliding contact portions (sliding contact surfaces A1, A2), and the teeth are reduced by the collision speed between the tooth portions at the helical spline engaging portions 23, 32, 33, 17 There is no change in the effect of suppressing the occurrence of the hitting sound.

  Further, the side surface 13b (sliding contact surface A2) of the flange engaging groove 13 is orthogonal to the axis of the inner cylinder portion 10, whereas the side surface 24b (sliding contact surface A1) of the flange 24 is a tapered shape having a convex inner diameter side. So that only the base end portion of the side surface 24b of the flange 24 is in sliding contact with the side surface 13b of the flange engaging groove 13, so that even if the sliding contact portion wears down due to long-term use, etc. A reduction in sliding friction torque at the contact portions (sliding contact surfaces A1, A2) is suppressed, and the effect of reducing the rattling noise between the tooth portions functions effectively.

  That is, if the apparatus is used for a long period of time, the sliding contact portions (sliding contact surfaces A1, A2), which are difficult to wear away, will also wear out, but the sliding contact portions (sliding contact surfaces A1, A2) will become familiar. As a result, the sliding friction coefficient μ at the sliding contact portions (sliding contact surfaces A1, A2) is reduced, and the sliding friction torque is reduced. Further, due to wear of the sliding contact portions (sliding contact surfaces A1, A2), the distance between the flange side surface 13a on which the disc spring laminated body 51 is interposed and the groove side surface 24a is increased, and the sliding contact portion (sliding contact surface A1) is increased. , A2), the spring biasing force is reduced, and the sliding friction torque is reduced.

  However, when the sliding contact portions (sliding contact surfaces A1, A2) wear out, as shown in the phantom line in FIG. 4, the annular region where the area of the sliding contact portions (sliding contact surfaces A1, A2) is indicated by the initial width d To an annular region enlarged outward in the radial direction indicated by D along the tapered sliding contact surface A1 of the flange 24, and the sliding friction torque at the sliding contact portions (sliding contact surfaces A1, A2) increases.

  As described above, even if the sliding contact portions (sliding contact surfaces A1, A2) are worn out by long-term use of the apparatus, the area of the sliding contact portions (sliding contact surfaces A1, A2) is increased radially outward. The increased amount of sliding friction torque at the sliding contact portion (sliding contact surface A1, A2) smoothes the sliding contact portion (sliding contact surface A1, A2) and the spring acts on the sliding contact portion (sliding contact surface A1, A2). Compensating for the decrease in sliding friction torque at the sliding contact portion (sliding contact surfaces A1, A2) due to the decrease in urging force, a significant decrease in sliding friction torque at the sliding contact portion (sliding contact surfaces A1, A2) is suppressed. Yes. That is, since the sliding friction torque at the sliding contact portions (sliding contact surfaces A1, A2) is kept substantially constant, the effect of reducing the rattling noise between the tooth portions of the helical spline engaging portions 23, 32, 33, 17 over a long period of time. Works effectively.

  Reference numeral 2b denotes a fastening screw that integrates the inner cylindrical portion 20 constituting a part of the camshaft 2 into the camshaft body. An oil passage 70 is provided around the fastening screw 2b in the camshaft 2. ing. Engine oil is pumped to the oil passage 70 by a pump P through an oil port of a journal bearing 73 of the camshaft 2 and a side hole 73a of the camshaft 2. Reference numeral 73 b is an oil introduction hole that is provided in the inner cylinder portion 20 and guides oil in the oil passage 70 into the flange engagement groove 13.

  On the other hand, the sprocket 12 provided with a circular hole for engaging the inner cylinder portion 20 at the center has a screw insertion hole 12b formed of a long hole through which the fastening screw 11 is inserted as shown in FIGS. An annular groove 64 is provided around the outer side of the side surface 13b of the flange engaging groove 13 (side surface on the inner diameter side of the sprocket 12). And a screw insertion hole (long hole) 12 b are connected via an annular groove 64. The engine oil guided to the flange engagement groove 13 through the oil introduction hole 73b is supplied to the sliding contact surfaces A1 and A2, and then externally through the annular groove 64 and the screw insertion hole (long hole) 12b. It is configured to be discharged. That is, the screw insertion hole (long hole) 12b functions as an oil discharge hole for discharging the oil in the flange engagement groove 13 to the outside.

  Further, as shown in enlarged views in FIGS. 4 and 5, the side surface 13b of the flange engaging groove 13 extends radially corresponding to the positions of the screw insertion holes (long holes) 12b arranged at equal intervals in the circumferential direction. The oil grooves 60 are provided at equal intervals in the circumferential direction, and the oil guided to the flange engagement grooves 13 from the oil introduction holes 73b is supplied to the entire sliding contact surfaces A1 and A2 through the oil grooves 60. ing.

  Further, a notch 62 having a width substantially matching the width of the screw insertion hole (long hole) 12 b is provided in a communication region of the annular groove 64 with the oil groove 60, and oil is supplied from the oil groove 60 and the annular groove 64. It can smoothly flow into the screw insertion hole (long hole) 12b. That is, most of the metal powder generated by rubbing the sliding contact portions (sliding contact surfaces A1, A2) is discharged together with the oil, but there is a possibility that the oil flow is stagnated and the metal powder accumulates at the bent portion of the oil flow path. However, by providing the notch 62 at the bent portion of the oil flow path, the flow from the oil groove 60 and the annular groove 64 to the screw insertion hole (long hole) 12b becomes smooth, and the oil flow path is made of metal powder. There is no clogging.

  Further, the flange engaging groove 13 is formed with a stepped portion 13c that can engage the tip of the flange 24 so that an excessive load is not applied to the disc spring laminated body 51 accommodated in the flange engaging groove 13. It has become. That is, since a minute gap is normally provided between the flange 24 and the stepped portion 13c and is held so as not to contact with each other, the electromagnetic brake means is caused by the sprocket 12 to which the driving force of the crankshaft is transmitted, for example. When pushed to the 40 side, an excessive load frequently acts on the disc spring laminated body 51 accommodated in the flange engaging groove 13, and the disc spring laminated body 51 is not preferable because it leads to fatigue failure. When 12 is greatly pressed to the electromagnetic brake side, the stepped portion 13c in the flange engaging groove 13 comes into contact with the flange 24, and an excessive compressive force does not act on the disc spring laminate 51, and the disc spring laminate 51 The durability is guaranteed.

  The disc spring laminated body 51 is interposed between the side surface 24a of the flange 24 and the side surface 13a of the flange engaging groove 13 via flat spacers 52 and 53, and is applied to the outer cylinder portion 10 and the inner cylinder portion 20. The surface hardening process is omitted. That is, in order to prevent wear of only a part of the side surface 24a of the flange 24 and the flange engaging groove 13 that interposes the disc spring laminate 51 and the disc spring laminate 51 directly hit, generally disc disc laminates. It is necessary to subject the surface of the body 51 to surface smoothing by polishing or the like, but by interposing the disc spring laminated body 51 via the spacers 52 and 53, it is possible to omit the surface smoothing processing. it can.

  In the first embodiment described above, the side surface 24b of the flange 24, which is the sliding contact portion (sliding contact surfaces A1, A2), is configured in a tapered shape. However, as a modification, FIG. Such a stepped tapered surface 24b1 or a convex curved tapered surface 24b2 as shown in FIG. 6B may be used.

  FIG. 7 is an enlarged cross-sectional view of the periphery of the sliding contact portion between the side surface of the flange and the side surface of the flange engaging groove, which is the main part of the phase varying device in the automobile engine according to the second embodiment of the present invention (first embodiment). 5 is a diagram corresponding to FIG. 4 in the example).

  In the first embodiment described above, the side surface 24b (sliding surface) of the flange 24 out of the side surface 24b of the flange 24 and the side surface 13b of the flange engaging groove 13 corresponding to the sliding contact portion (sliding contact surfaces A1, A2). Although the contact surface A1) is configured to have a tapered shape that is convex on the inner diameter side, in this second embodiment, the slidable contact surface A2 (side surface 13b of the flange engaging groove 13) is configured to have a tapered shape that is convex on the inner diameter side. ing.

  Further, a radially extending oil groove 60 is provided on the side surface 13b of the flange engaging groove 13, and an annular oil connected to the fastening screw insertion hole 12b (long hole H) that is an oil discharge hole is provided around the side surface 13b. A groove 64 is provided.

  Others are the same as in the first embodiment described above, and a duplicate description thereof is omitted.

  FIG. 8 is a longitudinal sectional view of a phase varying device in an automobile engine according to a fourth embodiment of the present invention, and FIG. 9 is a slidable contact portion between a side surface of a flange and a side surface of a flange engaging groove, which is a main part of the device. It is an expanded sectional view of the periphery.

  In the first and second embodiments described above, the flange engaging groove 13 is defined by the sprocket 12 and the spline case 16 constituting the outer tube portion 10, but in this third embodiment, the outer tube portion is formed. A flange engaging groove 13 is defined by the first sprocket 12, the inner flange plate 14, and the spline case 16 that constitute 10. That is, the side-by-side sprockets 12 and 12, the inner flange plate 14, and the spline case 16 are fastened together by the fastening screw 11 and integrated as the outer cylinder portion 10, but the concave portion 12 c on the inner peripheral side of the first sprocket 12 And the inner peripheral edge of the inner flange plate 14 define a flange engaging groove 13 that engages with the flange 24 on the inner cylindrical portion 20 side.

And the disc spring laminated body 51 is interposed between the side surface 24b of the flange 24 and the side surface 13b of the flange engaging groove 13, and the metal friction plate is interposed between the side surface 24a of the flange 24 and the side surface 13a of the flange engaging groove 13. 56 is interposed, and sliding friction torque at the sliding contact portion between the side surface 24a of the flange 24, the friction plate 56, and the side surface 13a of the flange engaging groove 13, that is, relative sliding between the outer tube portion 10 and the inner tube portion 20 is achieved. The frictional torque of the moving part is increased, and the occurrence of hitting sound that the tooth parts of the helical spline engaging parts 23, 32, 33, 17 between the intermediate member 30, the outer cylinder part 10 and the inner cylinder part 20 collide with each other is suppressed. ing.

Further, the side surface 13a of the flange engaging groove 13 which is the sliding contact surface B1 (the side surface 14a of the inner peripheral edge of the inner flange plate 14) and the both side surfaces 56a and 56b of the metal friction plate 56 which are the sliding contact surfaces B2 and B3 are Each of them is composed of a surface orthogonal to the axial center of the inner cylindrical portion 20, whereas the side surface 24a of the flange 24, which is the sliding contact surface B4, is formed in a tapered shape that is convex inward, and the sliding contact surface B1. , B2 is slidably contacted as a whole, but in the slidable contact surfaces B3, B4, only the base end portion of the slidable contact surface B4 is slidably contacted with the slidable contact surface B3. Even if the slidable contact surfaces B3, B4) wear, the sliding friction torque at the slidable contact portions (slidable contact surfaces B3, B4) is maintained substantially constant by the same operation as that in the structure of the first embodiment described above. Spline engaging portions 23, 32, 33, 17 The effect of reducing the rattling noise between the tooth portions functions effectively.

  Further, oil grooves 60 extending radially are provided on both side surfaces 56a and 56b (sliding contact surfaces B2 and B3) of the metal friction plate 56, and flange engagement grooves are formed on the sprocket 12 which is the outer cylinder portion 10. An oil discharge hole H <b> 2 extending obliquely outward from 13 is provided, and the engine oil in the flange engagement groove 13 is discharged out of the outer cylinder portion 10.

  Others are the same as those in the first embodiment described above, and the same reference numerals are given to omit redundant description.

Further, as the structure of the sliding contact portion between the side surface 24a of the flange 24 and the side surface 13a of the flange engaging groove 13 of the phase varying device in the third embodiment, the structure shown in FIGS.

That is, FIG. 10 shows four sliding contact surfaces B1, B2, B3 which are sliding contact portions between the side surface 24a of the flange 24 and the side surface 13a of the flange engaging groove 13 (the side surface 14a of the inner peripheral edge of the inner flange plate 14). Of B4, the slidable contact surface B1 is configured to have a convex shape on the inner diameter side, and FIG. FIG. 12 shows a configuration in which the sliding contact surface B3 of the four sliding contact surfaces B1, B2, B3, and B4 is formed in a tapered shape that is convex on the inner diameter side.

In the first and second embodiments, any one of the sliding contact surfaces A1, A2 is used. In the third to sixth embodiments, any one of the sliding contact surfaces B1, B2, B3, B4 is used. One of them is configured to have a tapered shape that is convex on the inner diameter side. In the first embodiment described above, both of the sliding contact surfaces A1 and A2 may be configured to have a tapered shape that is convex on the inner diameter side. In the third to sixth embodiments, two or more of the sliding contact surfaces B1, B2, B3, and B4 may be configured to have a convex shape on the inner diameter side. Also, the first to sixth embodiments described above. In the examples, the electromagnetic brake means 40 is used as means for moving the intermediate member 30 in the axial direction. However, the electromagnetic brake means 40 is not limited to the electromagnetic brake means 40, and the intermediate member 30 is moved in the axial direction by hydraulic drive means. It may be.

It is a longitudinal cross-sectional view of the phase variable apparatus in the engine for motor vehicles which is the 1st Example of this invention. It is a perspective view which shows the internal structure of the apparatus. It is a characteristic view which shows the relationship between the friction torque between the outer cylinder part (sprocket) of the same apparatus, and an inner cylinder part (camshaft), a hitting sound, and a response time. It is an expanded sectional view of the sliding contact part periphery between the side surface of a flange and the side surface of a flange engaging groove. It is a perspective view which shows the oil groove provided in the slidable contact surface of the side surface side of a flange engaging groove. (A) It is a modification of the 1st Example of this invention, and is an expanded sectional view of the sliding contact part periphery between the side surface of a flange and the side surface of a flange engaging groove. (B) It is another modification of the 1st Example of this invention, and is an expanded sectional view of the sliding contact part periphery between the side surface of a flange and the side surface of a flange engaging groove. It is an expanded sectional view of the sliding contact part periphery between the side surface of the flange which is the principal part of the phase variable apparatus in the engine for motor vehicles which is the 2nd Example of this invention, and the side surface of a flange engaging groove. It is a longitudinal cross-sectional view of the phase variable apparatus in the engine for motor vehicles which is the 3rd Example of this invention. It is an expanded sectional view of the sliding contact part periphery between the side surface of a flange and the side surface of a flange engaging groove. It is an expanded sectional view of the sliding contact part periphery between the side surface of the flange which is the principal part of the 4th Example of this invention, and the side surface of a flange engaging groove. It is an expanded sectional view of the sliding contact part periphery between the side surface of the flange which is the principal part of the 5th Example of this invention, and the side surface of a flange engaging groove. It is an expanded sectional view of the slide contact part periphery between the side surface of the flange which is the principal part of the 6th Example of this invention, and the side surface of a flange engaging groove. It is a longitudinal cross-sectional view of the phase variable apparatus in the conventional automobile engine.

Explanation of symbols

2 Camshaft 2b Cam 10 Annular outer cylinder part 11 Fastening screw 12 Sprocket 12b Screw insertion hole (long hole)
13 Flange engaging groove 13a, 13b Side surface 13c of flange engaging groove Stepped portion 14 Inner flange plate 16 Spline cases 17, 33, 23, 32 Helical spline engaging portion 18 Recessed groove 20 Annular inner cylindrical portion 24 Flange 24a, 24b Flange side surface 30 Intermediate member 31, 45 Square thread portion 40 Electromagnetic brake means 42 Electromagnetic clutch 44 Rotating drum 46 Torsion coil spring 51 Belleville spring laminate 52, 53 Spacer 56 Metal friction plate 60 Oil groove 62 Notch 64 Annular groove 73b Oil introduction hole A1, A2, B1, B2, B3, B4 Sliding surface H, H2 Oil discharge hole

Claims (5)

An annular outer cylindrical portion to which the driving force of the crankshaft is transmitted, an annular inner cylindrical portion on the driven side that is arranged coaxially with the outer cylindrical portion and extends to the camshaft, and the outer cylindrical portion and the inner cylindrical portion, respectively. An intermediate member arranged between the outer cylinder part and the inner cylinder part by engaging with the helical spline, moving in the axial direction and changing the phase of the inner cylinder part with respect to the outer cylinder part,
A flange is provided on the outer peripheral surface of the inner cylindrical portion, a flange engaging groove for engaging the flange is provided on the inner peripheral surface of the outer cylindrical portion, and an axial direction is provided on one side of the flange. is interposed a spring member extending is the other side of the flange perpendicular to the axis of the inner cylinder part, the flange engaging the groove orthogonal to the axis of the inner cylinder part opposite thereto In the phase varying device in an automobile engine in which the side surface is in sliding contact, the sliding friction torque in the sliding contact portion is increased, and the occurrence of hitting sound in the helical spline engaging portion is reduced.
Phase variable in an automobile engine characterized in that at least one of the opposing side surfaces constituting the sliding contact portion is formed in a tapered shape having a convex on the inner diameter side inclined with respect to a plane orthogonal to the axis of the inner cylinder portion. apparatus. An annular outer cylindrical portion to which the driving force of the crankshaft is transmitted, an annular inner cylindrical portion on the driven side that is arranged coaxially with the outer cylindrical portion and extends to the camshaft, and the outer cylindrical portion and the inner cylindrical portion, respectively. An intermediate member arranged between the outer cylinder part and the inner cylinder part by engaging with the helical spline, moving in the axial direction and changing the phase of the inner cylinder part with respect to the outer cylinder part,
A flange is provided on the outer peripheral surface of the inner cylindrical portion, a flange engaging groove for engaging the flange is provided on the inner peripheral surface of the outer cylindrical portion, and an axial direction is provided on one side of the flange. The extending spring member has a metal annular friction plate interposed on the other side surface thereof , and the other side surface of the flange perpendicular to the axis of the inner cylinder portion and the inner cylinder facing the other side surface sliding contact with the side surface of the flange engaging grooves orthogonal to the axis of the section is through the metal annular friction plates having a side orthogonal to the axis of the inner cylinder part, the sliding friction at the sliding contact portion In the phase varying device in an automobile engine in which the torque is increased to reduce the occurrence of hitting sound in the helical spline engaging portion,
Phase variable in an automobile engine characterized in that at least one of the opposing side surfaces constituting the sliding contact portion is formed in a tapered shape with a convex on the inner diameter side inclined with respect to a plane orthogonal to the axis of the inner cylinder portion. apparatus.   3. The phase varying device for an automobile engine according to claim 1, wherein the spring member is configured by a disc spring laminated body in which a plurality of disc springs are laminated.   The phase in the motor vehicle engine according to any one of claims 1 to 3, wherein flat spacers are interposed between the spring member, the side surface of the flange, and the side surface of the flange engaging groove. Variable device. The inner cylinder portion is provided with an oil introduction hole that communicates with the oil passage of the camshaft and opens into the flange engagement groove, and the outer cylinder portion communicates with the flange engagement groove and opens to the outside. The automobile according to any one of claims 1 to 4, wherein an oil discharge hole is provided, and at least one of the opposing side surfaces constituting the sliding contact portion is provided with a radially extending oil groove. Phase variable device for engine.

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