Valve opening / closing timing control device

Abstract

To provide a valve opening / closing timing control device capable of suppressing fluctuation of a spring load even when the position of a spring member inside a concave part changes.SOLUTION: A valve opening / closing timing control device comprises a drive-side rotor, a driven-side rotor, and a phase adjustment mechanism. The phase adjustment mechanism has an internally toothed output gear that is coaxial with a rotation axis core X and rotates integrally with the driven-side rotor, an externally toothed input gear that is positioned inside the output gear and rotates around an eccentric axis core Y, and an eccentric member 26. On a spring support surface 70a, which receives biasing force of a spring member 71 in a concave part 70 into which the spring member causing the output gear to mesh with the input gear is fitted, a top surface 70af is formed that protrudes less at a center position F in a circumferential direction of the spring support surface 70a when viewed in a direction along the eccentric axis core Y than an eccentric arc surface Sy centered on the eccentric axis core Y.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present invention relates to a valve timing control device. [Background technology]

[0002] The valve timing device described in Patent Document 1 as a valve timing control device has a configuration in which a concave accommodating portion (64) is formed on the eccentric outer peripheral surface (40) of a planetary carrier (32 in the document), a spring member (70) is fitted into this accommodating portion (64), and the elastic force of this spring member (70) acts on the planetary gear (33).

[0003] In addition, in the configuration of Patent Document 1, the elastic force of the spring member (70) acts on the external gear portion (39) of the planetary gear (33) to the internal gear portion (31) along the line of action (L), and this line of action (L) is inclined with respect to the eccentric direction line (E). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-38886 Summary of the Invention [Problem to be solved by the invention]

[0005] As described in Patent Document 1, the central portion of the support surface (the surface on the side of the rotation center line (O)) of the concave accommodating portion against which the spring member abuts projects gently outward, and the support surface of the spring member is molded into a gently curved shape to fit this projecting shape. In addition, the concave accommodating portion has wall-like portions formed on both ends in the circumferential direction in order to restrict the movement of the spring member in the circumferential direction of the planetary carrier.

[0006] The valve timing control device rotates at high speed, and because of the relationship between spring load and vibration, it is desirable that the load fluctuation be small even if the position of the spring member fluctuates in the recessed accommodating portion.

[0007] In contrast, even if a wall-shaped portion is formed at the circumferential end of the planet carrier in the housing portion, as in the housing portion of Patent Document 1, it is not possible to sufficiently regulate the fluctuation of the position of the spring member, and it was also expected that the spring member would be displaced.

[0008] If the spring member is displaced in this manner, the relationship between the protruding portion of the support surface of the accommodating section and the position of the spring member that abuts against it will change, causing the load on the spring member to fluctuate, which may result in increased vibration.

[0009] For these reasons, there is a demand for a valve timing control device that suppresses fluctuations in spring load even if the position of the spring member fluctuates within the recess. [Means for solving the problem]

[0010] A characteristic configuration of a valve opening / closing timing control device according to the present invention includes a drive-side rotor that rotates synchronously with a crankshaft of an internal combustion engine about a rotational axis, a driven-side rotor that is arranged coaxially with the rotational axis and inside the drive-side rotor and rotates integrally with a camshaft for opening and closing valves of the internal combustion engine, and a phase adjustment mechanism that adjusts the relative rotational phase of the drive-side rotor and the driven-side rotor, the phase adjustment mechanism including an internally toothed output gear that rotates integrally with the driven-side rotor about the same axis, an externally toothed input gear that has fewer teeth than the output gear, is arranged inside the output gear, and rotates about an eccentric axis that is parallel to the rotational axis, and The gear train comprises a coupling member that links the rotation, an eccentric member that meshes the external teeth of the input gear with the internal teeth of the output gear, and an electric actuator that drives and rotates the eccentric member around the rotation axis, wherein the output gear has a recessed portion that is recessed radially inward from the outer surface of the eccentric member so that a spring member that applies a biasing force to mesh the external teeth of the input gear with the internal teeth is positioned therein, and the spring support surface in the recessed portion that receives the biasing force of the spring member has a top surface that, when viewed in a direction along the eccentric axis, protrudes less at the central position in the circumferential direction of the spring support surface compared to an eccentric arc surface centered on the eccentric axis.

[0011] According to this characteristic configuration, the spring member fitted in the recessed portion exerts a biasing force from the spring support surface of the recessed portion toward the inner periphery of the input gear, maintaining the external teeth of the input gear in mesh with the internal teeth of the output gear. Furthermore, the spring support surface in the recessed portion that receives the biasing force of the spring member has an arc-shaped top surface with a large radius of curvature that reduces the amount of protrusion of the circumferential center of the spring support surface compared to an eccentric arc surface centered on the eccentric shaft when viewed in the direction along the eccentric shaft. This suppresses fluctuations in the biasing force even when the spring member is displaced circumferentially within the recessed portion. This provides a valve timing control device that suppresses fluctuations in the spring load even when the position of the spring member fluctuates within the recessed portion. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 2 is a cross-sectional view of the valve timing control device. [Figure 2] FIG. 2 is a cross-sectional view taken along line II-II in FIG. [Figure 3] FIG. 3 is a cross-sectional view taken along line III-III in FIG. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. [Figure 5] FIG. 2 is an exploded perspective view of the valve timing control device. [Figure 6] FIG. 10 is an enlarged view showing the positional relationship between the recessed portion, the spring material, the output gear, and the input gear. [Figure 7] FIG. 2 is a perspective view of a pair of spring members. [Figure 8] FIG. 4 is a cross-sectional view showing the shape of a spring support surface. [Figure 9] FIG. 10 is a perspective view of an eccentric member showing the position of a rough surface. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, an embodiment of a valve timing control device according to the present invention will be described with reference to the drawings. However, the present invention is not limited to the following embodiment, and various modifications are possible without departing from the spirit and scope of the present invention.

[0014] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. [Basic configuration] As shown in FIG. 1, the valve opening / closing timing control device 100 according to this embodiment includes a driving rotor A that rotates synchronously with a crankshaft 1 of an engine E as an internal combustion engine, a driven rotor B that rotates integrally with an intake camshaft 2 that opens and closes an intake valve 2B (an example of a valve), and a phase adjustment mechanism C that sets the relative rotational phase between the driving rotor A and the driven rotor B using the driving force of a phase control motor M.

[0015] The valve timing control device 100 includes a driving rotor A and a driven rotor B that are rotatable relative to each other within a set range around a rotation axis X.

[0016] The engine E is a four-stroke engine in which pistons 4 are housed in multiple cylinders 3 formed in a cylinder block, and these pistons 4 are connected to a crankshaft 1 by connecting rods 5. A timing chain 6 (which may be a timing belt or the like) is wound around an output sprocket 1S of the crankshaft 1 of the engine E and a drive sprocket 11S of the drive-side rotor A.

[0017] As a result, when the engine E is running, the entire valve timing control device 100 rotates around the rotation axis X. The phase adjustment mechanism C sets the relative rotation phase between the driving-side rotor A and the driven-side rotor B using the driving force of the phase control motor M, and realizes control of the opening and closing timing of the intake valve 2B by the cam portion 2A of the intake camshaft 2.

[0018] [Valve timing control device] As shown in Fig. 1, the drive-side rotor A has an outer case 11, on the outer periphery of which a drive sprocket 11S is formed, and a front plate 12, which are fastened together by a plurality of fastening bolts 13. The outer case 11 is a cylindrical type with a bottom and an opening at the bottom.

[0019] 1 to 5, an intermediate member 20 as a driven rotor B and a phase adjustment mechanism C (see FIG. 3, etc.) having a gear reduction mechanism are housed in the internal space of the outer case 11. The phase adjustment mechanism C is equipped with an Oldham coupling Cx (see FIGS. 4 and 5) that reflects a phase change in the driving rotor A and the driven rotor B.

[0020] The intermediate member 20 is integrally formed with a support wall portion 21 that is connected to the intake camshaft 2 in an orientation perpendicular to the rotation axis X, and a cylindrical wall portion 22 that is cylindrical and centered on the rotation axis X and protrudes in a direction away from the intake camshaft 2.

[0021] This intermediate member 20 is fitted into the outer case 11 so as to be freely rotatable relative to the outer case 11, with the outer surface of the cylindrical wall portion 22 in contact with the inner surface of the outer case 11, and is fixed to the end of the intake camshaft 2 by a connecting bolt 23 inserted into the central through hole of the support wall portion 21.

[0022] As shown in FIGS. 1 and 5, a groove 22a for retaining lubricating oil is formed around the entire outer periphery of the cylindrical wall 22.

[0023] As shown in Fig. 1, the phase control motor M is supported on the engine E by a support frame 7 so that its output shaft Ma is arranged coaxially with the rotation axis X. A pair of engagement pins 8 are formed on the output shaft Ma of the phase control motor M and oriented perpendicular to the rotation axis X (see also Fig. 4).

[0024] [Phase adjustment mechanism] 1 and 5, the phase adjustment mechanism C includes an intermediate member 20, an output gear 25 formed on the inner circumferential surface of the cylindrical wall portion 22 of the intermediate member 20, an eccentric member 26, a biasing mechanism S, a first bearing 28, a second bearing 29, an input gear 30, a fixed ring 31, a ring-shaped spacer 32, and an Oldham coupling Cx. Note that rolling bearings are used for the first bearing 28 and the second bearing 29, but plain bearings can also be used.

[0025] As shown in FIG. 1, a support surface 22S centered on the rotation axis X is formed on the inner periphery of the cylindrical wall portion 22 of the intermediate member 20 on the inside (at a position adjacent to the support wall portion 21) in a direction along the rotation axis X (hereinafter referred to as the axial direction), and an output gear 25 centered on the rotation axis X is integrally formed outside the support surface 22S (on the side farther from the intake camshaft 2).

[0026] As shown in Figures 1, 2, and 5, the eccentric member 26 is cylindrical. The eccentric member 26 has a circumferential support surface 26S on the outer circumferential surface, which is centered on the rotational axis X, on the inner side in the axial direction (the side closer to the intake camshaft 2). As shown in Figures 1, 3, and 5, the eccentric member 26 has an eccentric support surface 26E on the outer circumferential surface, which is centered on an eccentric axis Y that is eccentric and parallel to the rotational axis X, on the outer side (the side farther from the intake camshaft 2). The direction along the eccentric axis Y is the same as the axial direction, and therefore, hereinafter, the direction along the eccentric axis Y will also be simply referred to as the axial direction.

[0027] 5 and 6, a recessed portion 70 is formed on the eccentric support surface 26E. The recessed portion 70 is recessed radially inward of the eccentric member 26 and opens toward the end in the axial direction (toward the outer end: the direction toward the front plate 12). The recessed portion 70 has a spring support surface 70a and end wall surfaces 70b at both ends in the circumferential direction.

[0028] 6 and 8, the spring support surface 70a is formed in a shape in which the central portion in the circumferential direction is displaced radially inward compared to an arc surface centered on the eccentric axis Y (the details of this configuration will be described later). Also, as shown in Figs. 6, 8 and 9, the pair of end wall surfaces 70b are flat when viewed in the direction along the eccentric axis Y, and are formed symmetrically in the circumferential direction.

[0029] A pair of spring members 71 that constitute a biasing mechanism S, as will be described later, are fitted into the recessed portion 70.

[0030] As shown in Figures 1 and 5, a pair of engagement grooves 26T, which can engage with a pair of engagement pins 8 of a phase control motor M (see Figure 1), are formed on the inner periphery of the eccentric member 26 in a position parallel to the rotation axis X.

[0031] 1, 2, 3, and 6, a first bearing 28 is fitted onto the circumferential support surface 26S, and this first bearing 28 is fitted into the support surface 22S of the cylindrical wall portion 22, whereby the eccentric member 26 is supported rotatably about the rotation axis X with respect to the intermediate member 20. Also, as shown in FIGS. 1 and 3, the input gear 30 is supported rotatably about the eccentric axis Y with respect to the eccentric support surface 26E of the eccentric member 26 via a second bearing 29.

[0032] In this phase adjustment mechanism C, the number of teeth on the external teeth portion 30A of the input gear 30 is one tooth less than the number of teeth on the internal teeth portion 25A of the output gear 25, and a portion of the external teeth portion 30A of the input gear 30 meshes with a portion of the internal teeth portion 25A of the output gear 25.

[0033] The biasing mechanism S having a pair of spring members 71 applies a biasing force to the input gear 30 via the second bearing 29 so as to mesh a portion of the external teeth portion 30A of the input gear 30 with a portion of the internal teeth portion 25A of the output gear 25. The inner race 29a of the second bearing 29 is fitted onto the eccentric support surface 26E of the eccentric member 26, and the outer race 29b of the second bearing 29 is fitted onto the inner periphery of the input gear 30, so that the biasing force of the biasing mechanism S is applied to the input gear 30 in the radial direction.

[0034] The biasing mechanism S is configured by combining a pair of spring members 71 of the same shape and size as shown in FIG.

[0035] As shown in Figures 6 and 7, the spring member 71 comprises a curved portion 72 formed by bending a spring plate material, a support portion 73 formed by extending one side of the spring plate material of the curved portion 72 and facing the spring support surface 70a of the concave portion 70, and a biasing portion 74 formed by extending the other side of the spring plate material of the curved portion 72 and applying a biasing force to the inner peripheral side of the input gear 30, and a bent portion 75 formed by bending the tip side of the support portion 73 into a position away from the spring support surface 70a of the concave portion 70.

[0036] In other words, the curved portion 72 is formed into a shape in which the support portion 73 and the biasing portion 74 are arranged in a position that is approximately parallel to each other by bending the spring plate material so that the curved portion 72 has a U-shape when viewed in a direction along the eccentric axis Y when fitted into the concave portion 70.

[0037] As a result, as shown in Figure 7, a support side notch 73a oriented along the width direction is formed at the boundary between the curved portion 72 and the support portion 73, and a biasing side notch 74a oriented along the width direction is formed at the boundary between the curved portion 72 and the biasing portion 74.

[0038] 6 and 7, the two spring members 71 are configured as a biasing mechanism S arranged in mutually opposite orientations so that the respective curved portions 72 are located at the circumferential ends of the recessed portion 70, and are fitted into one recessed portion 70. By fitting in this manner, the two spring members 71 have their respective curved portions 72 spaced apart, and their two biasing portions 74 are arranged in parallel along the axial direction.

[0039] The spring member 71 is curved in the region extending from the curved portion 72 to the support portion 73 so as to conform to the spring support surface 70a of the concave portion 70, and forms a base end abutment portion Q at a position of the curved portion 72 facing the spring support surface 70a, and forms a tip end abutment portion R at the boundary between the support portion 73 and the bent portion 75.

[0040] Furthermore, as shown in Figure 6, the biasing portion 74 has a biasing apex 74b that protrudes radially outward from the eccentric member 26 so as to apply a concentrated biasing force to the inner surface of the inner race 29a of the second bearing 29 in the direction in which the external tooth portion 30A of the input gear 30 meshes most deeply with the internal tooth portion 25A of the output gear 25.

[0041] The curved portion 72 is a main portion that generates the biasing force of the spring member 71 by elastically deforming. By combining two spring members 71 and fitting them into the recessed portion 70, as shown in Figures 6 and 7, the biasing apexes 74b of the biasing portions 74 of the two spring members 71 are positioned to overlap when viewed in the direction along the eccentric axis Y. In this way, even with a structure in which two spring members 71 are fitted into one recessed portion 70, it is possible to maintain balance in the biasing forces acting on the input gear 30.

[0042] This allows the biasing force from the biasing apexes 74b of the two biasing portions 74 to act on the inner race 29a of the second bearing 29, with the base-end contact portion Q at the boundary between the support portion 73 and the curved portion 72 of the two spring members 71 acting as a fulcrum and abutting against the spring support surface 70a of the recessed portion 70. Furthermore, when the biasing force is applied in this manner, the tip-end contact portion R, which is the boundary between the curved portion 75 and the support portion 73, is maintained in a state of abutting against the spring support surface 70a of the recessed portion 70.

[0043] [Fixing ring / spring component] 1, 5, and 9, the fixing ring 31 is fitted into an annular groove 26d formed in an annular shape on the outer periphery of the eccentric support surface 26E of the eccentric member 26. The valve timing control device 100 includes a spacer 32 at a position where it contacts the fixing ring 31, thereby preventing the second bearing 29 from coming off.

[0044] [Phase adjustment mechanism: Oldham coupling] 1, 4, and 5, the Oldham coupling Cx is composed of a plate-shaped coupling member 40 that is integrally formed with a central annular portion 41, a pair of external engagement arms 42 that protrude radially outward from the annular portion 41 in a first direction (the left-right direction in FIG. 4), and an internal engagement arm 43 that protrudes radially outward from the annular portion 41 in a direction perpendicular to the first direction (the up-down direction in FIG. 4). Each of the pair of internal engagement arms 43 is formed with an engagement recess 43a that communicates with the opening of the annular portion 41.

[0045] A pair of guide grooves 11a are formed in the outer case 11 at the opening edge against which the front plate 12 abuts, as through-grooves, extending from the interior space of the outer case 11 to the exterior space, radially from the rotation axis X. The groove width of the guide grooves 11a is set slightly wider than the width of the external engagement arm 42, and a pair of discharge flow paths 11b are cut out and formed in each guide groove 11a. Note that the discharge flow paths 11b may be formed to allow lubricating oil to flow radially relative to the front plate 12.

[0046] A pocket 11c is formed by cutting out the inner periphery along the circumferential direction at the opening edge of the outer case 11 in a region other than the guide groove 11a. The pocket 11c collects foreign matter that moves to the outer periphery due to the centrifugal force caused by the rotation of the drive-side rotor A.

[0047] The input gear 30 is integrally formed with a pair of engagement protrusions 30T on an end surface facing the front plate 12. The engagement width of these engagement protrusions 30T is set slightly narrower than the engagement width of the engagement recess 43a of the internal engagement arm 43.

[0048] As a result, the pair of outer engaging arms 42 of the coupling member 40 are engaged with the pair of guide groove portions 11a of the outer case 11, and the pair of engaging projections 30T of the input gear 30 are engaged with the engaging recesses 43a of the pair of inner engaging arms 43 of the coupling member 40, thereby causing the Oldham coupling Cx to function.

[0049] The coupling member 40 is displaceable relative to the outer case 11 in a first direction (left-right direction in FIG. 4) in which the external engagement arm 42 extends, and the input gear 30 is displaceable relative to this coupling member 40 in a second direction (up-down direction in FIG. 4) along the formation direction of the engagement recess 43a of the internal engagement arm 43.

[0050] [Lubrication of Phase Adjustment Mechanism] 1, the intake camshaft 2 is formed with a lubricating oil passage 15 to which lubricating oil is supplied from an external oil pump P via an oil passage forming member 9. The support wall portion 21 of the intermediate member 20 has an opening 21a formed in a part of the surface that abuts against the intake camshaft 2, for guiding oil into the inside of the eccentric member 26.

[0051] Lubricating oil is supplied to the eccentric member 26 from the opening 21a. Furthermore, a lubrication recess 12a is formed on the surface of the front plate 12 facing the coupling member 40, providing a small radial gap between the surface of the coupling member 40, and lubricating oil is also supplied to this lubrication recess 12a. Although this lubrication recess 12a is formed on the inner periphery of the front plate 12, it may also be formed in an area that reaches the outer periphery of the front plate 12, or a configuration may be adopted in which lubricating oil is supplied to the gap between the front plate 12 and the coupling member 40 without the lubrication recess 12a.

[0052] As described above, a pair of discharge flow paths 11b are formed in the guide groove portion 11a (see FIGS. 4 and 5). Furthermore, by making the diameter of the opening 12b of the front plate 12 sufficiently larger than the inner diameter of the eccentric member 26, a difference in opening diameter is set between the opening edge of the front plate 12 and the inner periphery of the eccentric member 26.

[0053] With this configuration, the lubricating oil supplied from the oil pump P is supplied from the lubricating oil passage 15 of the intake camshaft 2 through the opening 21a of the support wall portion 21 of the intermediate member 20 to the internal space of the eccentric member 26. The lubricating oil supplied in this manner is supplied from the eccentric member 26 to the first bearing 28 by centrifugal force, thereby allowing the first bearing 28 to operate smoothly.

[0054] At the same time, the lubricating oil in the internal space of the eccentric member 26 is supplied to the coupling member 40 by centrifugal force, and is also supplied to the second bearing 29, and is supplied between the internal tooth portion 25A of the output gear 25 and the external tooth portion 30A of the input gear 30.

[0055] 1, the lubricating oil from the second bearing 29 is supplied between the front plate 12 and the coupling member 40 by the lubrication recess 12a, and is also supplied to the gap between the external engagement arm 42 of the coupling member 40 and the guide groove 11a of the outer case 11 (see also FIG. 5). The lubricating oil supplied to the coupling member 40 is discharged to the outside from the gap between the external engagement arm 42 of the coupling member 40 and the guide groove 11a of the outer case 11.

[0056] As shown in Figure 5, the front plate 12 has a protrusion 12c that protrudes inward on its inner surface (the side closer to the intake camshaft 2). The protrusion 12c lightly abuts the intermediate member 20 to the extent that it can slide against the intermediate member 20. The abutment of the intermediate member 20 with the protrusion 12c restricts movement of the intermediate member 20 toward the front plate 12. This allows the Oldham coupling Cx (coupling member 40) to operate smoothly, with a predetermined gap maintained between the front plate 12 and the intermediate member 20.

[0057] [Operational form of phase adjustment mechanism] Although not shown in the drawings, the phase control motor M is controlled by a control device configured as an ECU. The control device is provided with sensors in the engine E that can detect the rotational speeds (number of rotations per unit time) of the crankshaft 1 and the intake camshaft 2 and their respective rotational phases, and the detection signals of these sensors are input to the control device.

[0058] When the engine E is running, the control device maintains the relative rotational phase by driving the phase control motor M at a speed equal to the rotational speed of the intake camshaft 2. On the other hand, by reducing the rotational speed of the phase control motor M below the rotational speed of the intake camshaft 2, an advance operation is performed, and conversely, by increasing the rotational speed, a retard operation is performed.

[0059] When the phase control motor M rotates at the same speed as the outer case 11 (same speed as the intake camshaft 2), the meshing position of the external teeth portion 30A of the input gear 30 with the internal teeth portion 25A of the output gear 25 does not change, so the relative rotational phase of the driven side rotating body B with respect to the driving side rotating body A is maintained.

[0060] On the other hand, by driving and rotating the output shaft Ma of the phase control motor M at a speed higher or lower than the rotational speed of the outer case 11, the eccentric shaft Y in the phase adjustment mechanism C revolves around the rotational shaft X. This revolution displaces the meshing position of the internal teeth portion 25A of the output gear 25 with the external teeth portion 30A of the input gear 30 along the inner circumference of the output gear 25, and a rotational force acts between the input gear 30 and the output gear 25. In other words, a rotational force acts on the output gear 25 around the rotational shaft X, and a rotational force acts on the input gear 30 to rotate it about the eccentric shaft Y.

[0061] As described above, the input gear 30 does not rotate relative to the outer case 11 because its engagement projection 30T engages with the engagement recess 43a of the internal engagement arm 43 of the coupling member 40, and a rotational force acts on the output gear 25. The action of this rotational force causes the intermediate member 20, together with the output gear 25, to rotate about the rotation axis X relative to the outer case 11. As a result, the relative rotational phase between the drive-side rotor A and the driven-side rotor B is set, and the opening and closing timing of the intake camshaft 2 is set.

[0062] Furthermore, when the eccentric axis Y of the input gear 30 revolves around the rotation axis X, the input gear 30 is displaced, and therefore the coupling member 40 of the Oldham coupling Cx is displaced in the direction in which the external engagement arm 42 extends relative to the outer case 11 (first direction), and the input gear 30 is displaced in the direction in which the internal engagement arm 43 extends (second direction).

[0063] As described above, the number of teeth on the external toothed portion 30A of the input gear 30 is set to be one tooth less than the number of teeth on the internal toothed portion 25A of the output gear 25. Therefore, when the eccentric axis Y of the input gear 30 revolves around the rotation axis X by one revolution, the output gear 25 rotates by one tooth, thereby achieving a large reduction in speed.

[0064] [Concave portion] 6 and 8, the recessed portion 70 has a shape recessed radially inward from the eccentric support surface 26E (an example of an eccentric outer surface) when viewed in the direction along the eccentric axis Y. Also, when viewed in the direction along the eccentric axis Y, the end of the spring support surface 70a in the circumferential direction of the eccentric member 26 and the end wall surfaces 70b on both ends are formed to be smoothly connected by curved surfaces 70c.

[0065] When the two spring members 71 are fitted into the recessed portion 70, their respective base end abutment portions Q abut against the end wall surface 70b and the spring support surface 70a, and their respective tip end abutment portions R abut against the spring support surface 70a.

[0066] The spring support surface 70a of this recessed portion 70 is formed as a bulging surface St with a larger radius of curvature so as to reduce the amount of protrusion of a central position F (shown as a central line F in FIG. 8) in the circumferential direction of the spring support surface 70a compared to an eccentric arc surface Sy with an eccentric side radius Ry centered on the eccentric axis Y. The area of ​​this bulging surface St near the central position F is referred to as a top surface 70af.

[0067] The bulging surface St is formed as an arc with a central radius Rx centered on the rotation axis X. Note that the bulging surface St is not limited to an arc surface, and may be, for example, a part of an elliptical curve or a part of a quadratic function curve.

[0068] In this configuration, the positional relationship between the central position F of the eccentric arc surface Sy in the circumferential direction of the recessed portion 70 and the central position F of the top surface 70af in the circumferential direction of the recessed portion 70 is such that they are separated radially by a gap G.

[0069] The eccentric member 26 is cylindrical with a cylindrical internal space centered on the eccentric axis Y, and the central thickness Tc, which is the radial thickness from the inner surface of the eccentric member 26 to the central position F of the spring support surface 70a, is set to be smaller than the end thickness Te, which is the thickness from the inner surface of the eccentric member 26 to both ends of the spring support surface 70a in the circumferential direction.

[0070] Furthermore, a rough surface RF is formed on the top surface 70af of the spring support surface 70a by forming a plurality of groove-like portions 70d oriented along the eccentric axis Y. The plurality of groove-like portions 70d are formed by a laser beam, and the rough surface RF thus formed functions to suppress the phenomenon of the spring member 71 moving in the circumferential direction relative to the spring support surface 70a (see also FIG. 9).

[0071] In this configuration, the two spring members 71 fitted into the recessed portion 70 exert a spring force from the spring support surface 70a of the recessed portion 70 in the direction of the inner circumference of the input gear 30, maintaining the internal tooth portion 25A of the output gear 25 in mesh with the external tooth portion 30A of the input gear 30.

[0072] In this configuration, the top surface 70af of the spring support surface 70a is formed so that the amount of protrusion of the central position F in the circumferential direction of the spring support surface 70a is smaller than that of the eccentric arc surface Sy when viewed in the direction along the eccentric axis Y. Therefore, even when the spring member 71 is displaced inside the recessed portion 70 in a direction away from the central position F, the amount of change in the biasing force is small, and vibration is not caused when the valve timing control device 100 rotates at high speed.

[0073] Furthermore, in this embodiment, the spring member 71 has the tip abutment portion R in contact with the vicinity of the central position F in the circumferential direction of the spring support surface 70a, so when the spring member 71 is displaced inside the recessed portion 70 in a direction away from the central position F, the tip abutment portion R moves in a state of contact with the top surface 70af, and even if such a movement occurs, fluctuations in the spring force acting from the spring member 71 are suppressed.

[0074] In addition, in this configuration, a rough surface RF is formed on the spring support surface 70a, so that as described above, when the spring member 71 moves circumferentially around the spring support surface 70a, a frictional force acts on the tip-side abutment portion R, making it possible to suppress the movement of the spring member 71.

[0075] [Another embodiment] The present invention may be configured as follows in addition to the above-described embodiments (common numbers and symbols are used to designate components having the same functions as those in the embodiments).

[0076] (a) As partially explained in the embodiment, the bulging surface St is not limited to an arc surface, but can also be a curve that follows part of a curve that forms an ellipse, a part of a curve that forms a quadratic function, or a curve that connects multiple functions to form a gently protruding shape.

[0077] (b) The spring member 71 may be a single member.

[0078] (c) For example, the rough surface RF may be formed by knurling. It is also possible to form the spring support surface 70a into a rough surface RF using a surface processing device.

[0079] Furthermore, the configurations disclosed in the above embodiments (including other embodiments, the same applies below) can be applied in combination with configurations disclosed in other embodiments, as long as no contradictions arise. Furthermore, the embodiments disclosed in this specification are examples, and the embodiments of the present invention are not limited to these, and can be modified as appropriate within the scope that does not deviate from the purpose of the present invention.

[0080] In the above-described embodiment, the following configurations are envisioned. (1) A drive rotor A that rotates synchronously with a crankshaft 1 of an internal combustion engine (engine E) about a rotation axis X; a driven rotor B that is arranged coaxially with the rotation axis X and inside the drive rotor A and rotates integrally with a camshaft (intake camshaft 2) for opening and closing valves of the internal combustion engine (engine E); and a phase adjustment mechanism C that adjusts the relative rotation phase of the drive rotor A and the driven rotor B. The phase adjustment mechanism C includes an internally toothed output gear 25 that rotates integrally with the driven rotor B about the same axis X; an externally toothed input gear 30 that has fewer teeth than the output gear 25 and is arranged inside the output gear 25 and rotates about an eccentric axis Y that is parallel to the rotation axis X; a coupling member 40 that links the input gear 30 to the rotation of the drive rotor A; and The valve timing control device 100 has an eccentric member 26 that meshes the external teeth 30A of the input gear 30 with the internal teeth 25A of the output gear 25, and an electric actuator (phase control motor M) that drives and rotates the eccentric member 26 about the rotation axis X, and the output gear 25 has a recessed portion 70 that is recessed radially inward from the outer surface of the eccentric member 26 so that a spring member 71 that applies an urging force to mesh the external teeth 30A of the input gear 30 with the internal teeth 25A is disposed in the output gear 25, and the spring support surface 70a that receives the urging force of the spring member 71 in the recessed portion 70 has a top surface 70af that protrudes less at a central position F in the circumferential direction of the spring support surface 70a when viewed in a direction along the eccentric axis Y than an eccentric arc surface Sy that is centered on the eccentric axis Y.

[0081] According to this, the spring member 71 fitted in the recessed portion 70 applies a biasing force from the spring support surface 70a of the recessed portion 70 toward the inner periphery of the input gear 30, maintaining a state in which the external teeth 30A of the input gear 30 mesh with the internal teeth 25A of the output gear 25. Furthermore, the spring support surface 70a of the recessed portion 70 has a top surface 70af that protrudes less at a central position F of the spring support surface 70a in the circumferential direction than the eccentric arc surface Sy centered on the eccentric axis Y when viewed in the direction along the eccentric axis Y. Therefore, even if the spring member 71 is displaced circumferentially within the recessed portion 70, a phenomenon in which the biasing force acting from the spring member 71 greatly fluctuates in the direction in which the external teeth 30A of the input gear 30 mesh with the internal teeth 25A of the output gear 25 is suppressed. This suppresses a phenomenon in which vibration occurs even when the valve timing control device 100 rotates at high speed.

[0082] (2) In the valve opening / closing timing control device 100 of (1), the eccentric member 26 is cylindrical with a cylindrical internal space centered on the eccentric axis Y, and it is preferable that the central thickness Tc, which is the radial thickness from the inner surface of the eccentric member 26 to the top surface 70af of the spring support surface 70a, is set smaller than the end thickness Te, which is the thickness from the inner surface of the eccentric member 26 to both end portions in the circumferential direction of the spring support surface 70a.

[0083] As a result, the concave portion 70 is formed so as to be recessed relative to the eccentric member 26, and even if a load acts on the circumferential end of the spring support surface 70a, the strength of the end side of the concave portion 70 in the circumferential direction is high, so that the end of the spring support surface 70a will not be damaged.

[0084] (3) In the valve timing control device 100 of (1) or (2), it is preferable that the two spring members 71 are arranged in a circumferential direction of the recessed portion 70.

[0085] By using two spring members 71, even if one of the spring members 71 is damaged, it is possible to maintain the internal tooth portion 25A of the output gear 25 in mesh with the external tooth portion 30A of the input gear 30.

[0086] (4) In the valve timing control device 100 of any one of (1) to (3), it is preferable that the top surface 70af of the recessed portion 70 is formed as a rough surface RF.

[0087] With this, even when an external force that displaces the spring member 71 in the circumferential direction inside the recessed portion 70 acts, the rough surface RF suppresses the movement of the spring member 71. [Industrial Applicability]

[0088] The present invention can be used in a valve timing control device. [Explanation of symbols]

[0089] 1: crankshaft, 2: intake camshaft (camshaft), 25: output gear, 26: eccentric member, 26E: eccentric support surface, 26d: annular groove, 30: input gear, 31: fixing ring, 40: coupling member, 70: concave portion, 70a: spring support surface, 70af: top surface, 71: spring member, 100: valve timing control device, A: driving side rotating body, B: driven side rotating body, C: phase adjustment mechanism, E: internal combustion engine (engine), F: center position, M: phase control motor (electric actuator), RF: rough surface, Sy: eccentric arc surface, Tc: center thickness, Te: end thickness, X: rotation axis center, Y: eccentric axis center

Claims

1. a drive-side rotor that rotates synchronously with the crankshaft of the internal combustion engine around a rotation axis; a driven-side rotor that is disposed coaxially with the rotation axis and inside the driving-side rotor, and that rotates integrally with a camshaft for opening and closing a valve of the internal combustion engine; a phase adjustment mechanism that adjusts the relative rotational phase between the driving-side rotor and the driven-side rotor, the phase adjustment mechanism includes an internally toothed output gear that is coaxial with the rotation axis and rotates integrally with the driven-side rotor; an externally toothed input gear that has fewer teeth than the output gear and is disposed inside the output gear and rotates around an eccentric axis parallel to the rotation axis; a coupling member that links the input gear to the rotation of the drive-side rotor; an eccentric member that meshes the external teeth of the input gear with the internal teeth of the output gear; and an electric actuator that drives and rotates the eccentric member around the rotation axis, a recessed portion recessed radially inward from an outer surface of the eccentric member is formed in the output gear so that a spring member that applies a biasing force to cause the internal tooth portion to mesh with the external tooth portion of the input gear is disposed therein; a spring support surface in the recessed portion that receives the biasing force of the spring member, the spring support surface having a top surface that protrudes less at a central position in the circumferential direction than an eccentric arc surface that is centered on the eccentric axis when viewed in a direction along the eccentric axis;

2. the eccentric member is tubular and has a cylindrical internal space centered on the eccentric shaft, 2. The valve opening / closing timing control device according to claim 1, wherein a central thickness, which is a radial thickness from the inner circumferential surface of the eccentric member to the top surface of the spring support surface, is set smaller than an end thickness, which is a thickness from the inner circumferential surface of the eccentric member to both end portions of the spring support surface in the circumferential direction.

3. 3. The valve timing control device according to claim 1, wherein the pair of spring members are arranged so as to be distributed in the circumferential direction of the recessed portion.

4. 3. The valve timing control device according to claim 1, wherein the top surface of the recessed portion is formed as a rough surface.

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