Valve opening / closing timing control device

Abstract

To provide a valve opening / closing timing control device capable of appropriately setting valve timing when starting an internal combustion engine at low temperature.SOLUTION: A valve opening / closing timing control device includes: a driving side rotating body that rotates in synchronization with a crankshaft of an internal combustion engine; a driven side rotating body that is disposed on the inner side of the driving side rotating body and integrally rotates with a camshaft for opening / closing a valve of the internal combustion engine; a phase adjustment mechanism that has a plurality of gears for decelerating driving rotating force of an electric motor M and sets a relative rotation phase of the driving side rotating body and the driven side rotating body; a lubrication oil supply section that supplies lubrication oil from outside to the phase adjustment mechanism; and an oil discharge control section 83 that performs oil discharge control for discharging the lubrication oil by changing the relative rotation phase by driving the electric motor M along with stop control for stopping the internal combustion engine.SELECTED DRAWING: Figure 7

Description

Technical Field

[0001] The present invention relates to a valve opening / closing timing control device.

Background Art

[0002] Patent Document 1 describes a valve opening / closing timing control device (valve timing device in the document) capable of setting the valve timing of an intake valve of an internal combustion engine by the driving force of an electric motor.

[0003] The valve opening / closing timing control device described in Patent Document 1 is set in four regions as the temperature region of the internal combustion engine (engine in the document), determines which of the four temperature regions the temperature of the internal combustion engine belongs to at the start of the internal combustion engine, and sets the target valve timing set for each temperature region.

[0004] When the temperature of the internal combustion engine is decreasing, the viscosity of the engine oil is high and the load during cranking increases. Therefore, by performing control to set the valve timing of the valve opening / closing timing control device more on the retarded side as the temperature decreases, the load acting on the crankshaft in the intake stroke is reduced.

[0005] Patent Document 2 describes a valve opening / closing timing control device capable of being set by the driving force of an electric motor, similar to Patent Document 1.

[0006] The valve opening / closing timing control device described in Patent Document 2 includes a driving-side rotating body, a driven-side rotating body, a gear-type phase adjustment mechanism, a phase control motor for driving the phase adjustment mechanism, an oldham coupling, a front plate, and the like.

[0007] The valve opening / closing timing control device described in Patent Document 2 accommodates the driven-side rotating body inside the driving-side rotating body, and the phase adjustment mechanism is configured as a hypo-cyclic reduction mechanism so as to relatively rotate the driving-side rotating body and the driven-side rotating body by the driving force of the phase control motor.

[0008] Further, this valve opening / closing timing control device is configured to be able to discharge the lubricating oil remaining inside the internal combustion engine when the engine stops, from the guide groove portion of the outer case or the opening of the front plate.

Prior Art Documents

Patent Documents

[0009]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0010] When starting an internal combustion engine in an extremely low temperature environment, it is possible to utilize the technology described in Patent Document 1 to address the problem of viscous friction during startup associated with the increase in the viscosity of engine oil.

[0011] However, when starting an internal combustion engine in a low temperature environment, if lubricating oil remains inside the valve opening / closing timing control device, it becomes difficult to set the valve timing by the control of the valve opening / closing timing control device immediately after starting the internal combustion engine, and it may also take time for the setting.

[0012] To address such inconveniences, as described in Patent Document 2, a configuration in which the lubricating oil inside the valve opening / closing timing control device is discharged from the groove portion or the opening can also be considered. However, even with such a configuration, there are cases where the lubricating oil cannot be sufficiently discharged, and it may not be possible to quickly set the valve timing by the valve opening / closing timing control device when starting the internal combustion engine in a low temperature environment.

[0013] For these reasons, a valve opening / closing timing control device that can properly set the valve timing when starting the internal combustion engine at low temperatures is required.

Means for Solving the Problems

[0014] The configuration of the valve opening / closing timing control device according to the present invention includes a drive-side rotating body that rotates synchronously with the crankshaft of an internal combustion engine around a rotation axis center, a driven-side rotating body that is coaxial with the rotation axis center and is disposed inside the drive-side rotating body and rotates integrally with a camshaft for opening and closing valves of the internal combustion engine, a plurality of gears that reduce the driving rotational force of an electric motor, a phase adjustment mechanism that sets a relative rotational phase between the drive-side rotating body and the driven-side rotating body, a lubricating oil supply unit that supplies lubricating oil from the outside to the phase adjustment mechanism, and an oil discharge control unit that performs oil discharge control to change the relative rotational phase by driving the electric motor and discharge the lubricating oil in accordance with stop control for stopping the internal combustion engine.

[0015] According to this configuration, in accordance with stop control for stopping the internal combustion engine, the oil discharge control unit changes the relative rotational phase, so that the lubricating oil remaining inside can be discharged, for example, from an opening portion at an end of the drive-side rotating body or from a gap between the driven-side rotating body and a plurality of gears constituting the phase adjustment mechanism. By actively discharging the lubricating oil remaining inside in this way, even if the viscosity of the lubricating oil increases in a low-temperature environment, the operating speed of the phase adjustment mechanism will not be reduced, and an excessive load will not be applied to the electric motor. Therefore, a valve opening / closing timing control device is configured that can appropriately set the valve timing when starting the internal combustion engine at low temperature.

Brief Description of the Drawings

[0016]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Embodiment for Carrying Out the Invention

[0017] Hereinafter, an embodiment of the valve opening / closing timing control device 100 according to the present invention will be described with reference to the drawings. In this embodiment, as an example of the phase adjustment mechanism C, an output gear 25 having an annular internal tooth portion 25A and an input gear 30 having an annular external tooth portion 30A that meshes with a part of the output gear 25 are provided, and these are driven by a phase control motor M (electric motor) outside the driving-side rotating body A. Although the valve opening / closing timing control device 100 is described with this configuration, the valve opening / closing timing control device 100 is not limited to the following embodiments, and various modifications can be made without departing from the gist thereof.

[0018] 〔Basic Configuration〕 As shown in FIG. 1, the valve opening / closing timing control device 100 according to this embodiment includes a driving-side rotating body A, a driven-side rotating body B, and a phase adjustment mechanism C. The driving-side rotating body A rotates synchronously with the crankshaft 1 of the engine E as an internal combustion engine around the rotation axis core X. The driven-side rotating body B is arranged inside the driving-side rotating body A coaxially with the rotation axis core X. Further, the driven-side rotating body B rotates integrally with an intake camshaft 2 (an example of a camshaft) that opens and closes the intake valve 2B of the engine E (internal combustion engine). The phase adjustment mechanism C sets the relative rotational phase between the driving-side rotating body A and the driven-side rotating body B by the driving force of the phase control motor M (an example of an electric motor).

[0019] The valve opening / closing timing control device 100 is provided in the engine E of a vehicle such as a passenger car, and realizes control of the valve timing (opening / closing timing) of the intake valve 2B, the exhaust valve, or the intake / exhaust valve.

[0020] The engine E is configured in a four-cycle type that houses a piston 4 in each of a plurality of cylinders 3 formed in a cylinder block, and connects each piston 4 to a crankshaft 1 by a connecting rod 5. A timing chain 6 (or a timing belt etc. may also be used) is wound around an output sprocket 1S of the crankshaft 1 of this engine E and a drive sprocket 11S of the drive-side rotating body A.

[0021] Accordingly, during the operation of the engine E, the valve opening / closing timing control device 100 rotates as a whole about the rotation axis center X. Further, the valve opening / closing timing control device 100 is configured such that a phase adjustment mechanism C is operated by the driving force of a phase control motor M (electric motor), and the driven-side rotating body B can be displaced in the same direction or the opposite direction as the rotation direction with respect to the drive-side rotating body A.

[0022] The valve opening / closing timing control device 100 can set the relative rotational phase between the drive-side rotating body A and the driven-side rotating body B to the advancing angle side and the retarding angle side by the operation of the phase adjustment mechanism C, and sets the opening / closing timing (opening / closing timing) of the intake valve 2B by the cam portion 2A of the intake camshaft 2.

[0023] In the advancing angle operation for setting the relative rotational phase to the advancing angle side, the intake timing of the intake valve 2B is advanced and the intake compression ratio is increased. Also, in the retarding angle operation for setting the relative rotational phase to the retarding angle side, the intake timing of the intake valve 2B is retarded and the intake compression ratio is reduced.

[0024] 〔Valve Opening / Closing Timing Control Device〕 As shown in FIG. 1, the drive-side rotating body A fastens an outer case 11 having a drive sprocket 11S formed on the outer periphery and a front plate 12 with a plurality of fastening bolts 13. The outer case 11 is of a bottomed cylindrical type having an opening at the bottom. The front plate 12 is provided on the side opposite to the intake camshaft 2 with respect to the eccentric member 26 in the direction along the rotation axis center X.

[0025] As shown in FIGS. 1 and 2, an intermediate member 20 as a driven-side rotating body B and a phase adjustment mechanism C having a plurality of gears are accommodated in the internal space of the outer case 11. The phase adjustment mechanism C is interlocked with an Oldham coupling Cx that reflects a phase change to the drive-side rotating body A and the driven-side rotating body B.

[0026] The intermediate member 20 constituting the driven-side rotating body B is integrally formed with a support wall portion 21 that is connected to the intake camshaft 2 in a posture orthogonal to the rotation axis core X, and a cylindrical wall portion 22 that is cylindrical about the rotation axis core X and projects from the outer peripheral edge of the support wall portion 21 in a direction away from the intake camshaft 2.

[0027] The intermediate member 20 is relatively rotatably fitted into 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 portion of the intake camshaft 2 by a connecting bolt 23 inserted through the central through hole of the support wall portion 21. In the state of being fixed in this way, the end portion of the connecting bolt 23 on the outer side (the side farther from the intake camshaft 2) of the cylindrical wall portion 22 is located inside the front plate 12.

[0028] As shown in FIGS. 1 and 2, a groove portion 22a is formed over the entire circumference on the outer peripheral side of the cylindrical wall portion 22. By this groove portion 22a, the retention of lubricating oil between the outer surface of the cylindrical wall portion 22 and the inner surface of the outer case 11 is improved. Thereby, the frictional force between the cylindrical wall portion 22 and the outer case 11 is reduced, and smooth relative rotation between the intermediate member 20 and the outer case 11 is realized.

[0029] As shown in FIG. 1, the phase control motor M is supported by the engine E by a support frame 7 so that its output shaft Ma is arranged coaxially with the rotation axis core X. A pair of engagement pins 8 having a posture orthogonal to the rotation axis core X are formed on the output shaft Ma of the phase control motor M.

[0030] 〔Phase Adjustment Mechanism〕 As shown in FIGS. 1 to 3, the phase adjustment mechanism C includes an intermediate member 20, an output gear 25 formed on the inner peripheral surface of the cylindrical wall portion 22 of the intermediate member 20, an eccentric member 26, an elastic member 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 although rolling bearings are used for the first bearing 28 and the second bearing 29, sliding bearings can also be used. In the present embodiment, the first bearing 28 is a ball bearing having an inner ring 28a that contacts the outer peripheral surface of the eccentric member 26 and an outer ring 28b that contacts the inner peripheral surface of the intermediate member 20.

[0031] Further, the second bearing 29 is a ball bearing having an inner ring 29a that contacts the outer peripheral surface of the eccentric member 26 and an outer ring 29b that contacts the inner peripheral surface of the input gear 30.

[0032] As shown in FIG. 1, a support surface 22S centered on the rotation axis X is formed on the inner circumference of the cylindrical wall portion 22 of the intermediate member 20 on the inner side (position adjacent to the support wall portion 21) in the 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 on the outer side of the support surface 22S (the side farther from the intake camshaft 2).

[0033] As shown in FIGS. 1 to 3, the eccentric member 26 is cylindrical. The eccentric member 26 has a circumferential support surface 26S on the outer peripheral surface centered on the rotation axis X on the inner side in the axial direction (the side closer to the intake camshaft 2). The eccentric member 26 has a flange portion 26Q that protrudes further radially outward from the circumferential support surface 26S on the inner side in the axial direction of the circumferential support surface 26S (the side even closer to the intake camshaft 2).

[0034] Further, the eccentric member 26 has an eccentric support surface 26E on the outer peripheral surface centered on an eccentric axis Y that is eccentric in a posture parallel to the rotation axis X on the outer side (the side farther from the intake camshaft 2). Therefore, the eccentric member 26 is formed with the flange portion 26Q, the circumferential support surface 26S, and the eccentric support surface 26E arranged in this order along the axial direction from the side closer to the intake camshaft 2.

[0035] Since the direction along the eccentric axis Y is the same as the axial direction, hereinafter, the direction along the eccentric axis Y will also be simply referred to as the axial direction.

[0036] As shown in FIGS. 1 and 3, on the eccentric support surface 26E, a first concave portion 70 that is recessed inward along the radial direction of the eccentric member 26 is formed. On the bottom surface of the first concave portion 70, at both ends in the circumferential direction of the eccentric member 26, a pair of second concave portions 79, 79 that are recessed toward the radial axis side of the eccentric member 26 are formed. In the present embodiment, the first concave portion 70 is symmetric in the circumferential direction.

[0037] The second concave portions 79, 79 are respectively formed at the respective ends in the circumferential direction of the eccentric member 26 in the first concave portion 70. The maximum depth of the bottom surface of the second concave portions 79, 79 in the radial direction of the eccentric member 26 is deeper than the depth of the bottom surface near the center in the circumferential direction of the eccentric member 26 in the first concave portion 70. The surfaces from the respective bottom surfaces of the second concave portions 79, 79 to the ends in the circumferential direction of the eccentric member 26 are formed in a shape that follows the curved shape of the spring members 71 described later.

[0038] An elastic member S is fitted into the first concave portion 70. The elastic member S includes a pair of spring members 71, 71. In the present embodiment, the pair of spring members 71, 71 have the same shape and the same size respectively. The elastic member S applies a biasing force to the input gear 30 via the second bearing 29 so that a part of the outer tooth portion 30A of the input gear 30 meshes with a part of the inner tooth portion 25A of the output gear 25.

[0039] Thereby, it is possible to prevent an increase in backlash between the input gear 30 and the output gear 25 and prevent abnormal noise. Further, the durability of the input gear 30 and the output gear 25 can be improved.

[0040] As shown in FIGS. 1 and 3, on the inner circumference of the eccentric member 26, a pair of engagement grooves 26T with which each of the pair of engagement pins 8 of the phase control motor M (see FIG. 1) can engage are formed in a posture parallel to the rotation axis X.

[0041] As shown in Fig. 3, on the inner circumferential side of the open end on the outer side (the side far from the intake camshaft 2) of the eccentric member 26, taper portions 26c (inclined portions) whose diameters become smaller toward the inner side (the side close to the intake camshaft 2) are formed on both side portions of the engagement groove 26T. When engaging the pair of engagement pins 8 of the phase control motor M with the engagement groove 26T of the eccentric member 26, the engagement pins 8 are guided by the taper portions 26c into the engagement groove 26T, facilitating the engagement operation between the phase control motor M and the eccentric member 26.

[0042] As shown in Fig. 1, for this eccentric member 26, the first bearing 28 is externally fitted on the circumferential support surface 26S, and by fitting this first bearing 28 into the support surface 22S of the cylindrical wall portion 22, it is rotatably supported with respect to the intermediate member 20 about the rotation axis core X. Further, as shown in Fig. 1, the input gear 30 is rotatably supported about the eccentric axis core Y with respect to the eccentric support surface 26E of the eccentric member 26 via the second bearing 29.

[0043] In this phase adjustment mechanism C, the number of teeth of the external tooth portion 30A of the input gear 30 is set to be one tooth less than the number of teeth of the internal tooth portion 25A of the output gear 25. And a part of the external tooth portion 30A of the input gear 30 meshes with a part of the internal tooth portion 25A of the output gear 25.

[0044] As shown in Fig. 1, the fixed ring 31 is supported in a fitted state on the outer circumference of the eccentric member 26 to prevent the second bearing 29 from coming off via the spacer 32.

[0045] As shown in Fig. 1, a gap is formed between the eccentric member 26 and the support wall portion 21 of the intermediate member 20.

[0046] 〔Phase Adjustment Mechanism: Oldham Coupling〕 As shown in FIGS. 1 to 3, the Oldham joint Cx is composed of a plate-shaped joint member 40 integrally formed with a central annular portion 41, a pair of external engagement arms 42 protruding radially outward along a first direction (left-right direction in FIG. 2) from the annular portion 41, and internal engagement arms 43 protruding radially outward along a second direction (up-down direction in FIG. 2) orthogonal to the first direction from the annular portion 41. Engagement recesses 43a connected to the opening of the annular portion 41 are formed in each of the pair of internal engagement arms 43.

[0047] In the outer case 11, at the opening edge portion where the front plate 12 abuts, a pair of guide groove portions 11a extending radially around the rotation axis core X are formed in a through groove shape across the internal space to the external space of the outer case 11. The groove width of this guide groove portion 11a is set slightly wider than the width of the external engagement arm 42, and cut portions 42a cut obliquely are formed at both circumferential ends of the external engagement arm 42 as shown in FIG. 5. A pair of discharge channels 11b are formed by notches in each of the guide groove portions 11a and the cut portions 42a at both circumferential ends of the external engagement arm 42.

[0048] At the opening edge portion of the outer case 11, at portions other than the guide groove portions 11a, one or more pocket portions 11c with the inner circumferential side notched along the circumferential direction are formed. Foreign objects that move to the outer circumferential side under the centrifugal force caused by the rotation of the driving-side rotating body A are collected in the pocket portions 11c. FIGS. 2 and 3 show a structure in which four pocket portions 11c are formed.

[0049] Also, a pair of engagement protrusions 30T are integrally formed on the end face of the input gear 30 facing the front plate 12. The engagement width of this engagement protrusion 30T is set slightly narrower than the engagement width of the engagement recess 43a of the internal engagement arm 43.

[0050] With such a configuration, it is possible to make the Oldham joint Cx function by engaging the pair of external engagement arms 42 of the joint member 40 with the pair of guide groove portions 11a of the outer case 11 and engaging the pair of engagement protrusions 30T of the input gear 30 with the engagement recesses 43a of the pair of internal engagement arms 43 of the joint member 40.

[0051] In addition, the joint member 40 can be displaced in the first direction (the left - right direction in FIG. 2) in which the outer engagement arm 42 extends with respect to the outer case 11, and the input gear 30 can be displaced freely in the second direction (the up - down direction in FIG. 2) along the formation direction of the engagement recess 43a of the inner engagement arm 43 with respect to this joint member 40.

[0052] As shown in FIGS. 1 and 3, the spacer 32 makes the distance of the gap in which the second bearing 29 can move in the axial direction equal to or less than a predetermined set value. By providing the spacer 32 between the Oldham joint Cx (joint member 40) and the second bearing 29, the movement of the second bearing 29 in the axial direction is restricted to a distance equal to or less than the predetermined set value.

[0053] Also, on the surface of the front plate 12 facing the input gear 30, a recess 12d that is recessed toward the outside (the side far from the intake camshaft 2) is formed. The recess 12d is provided to face the opening portion of the joint member 40 in the front plate 12, and the recess 12d is formed slightly wider than the opening portion of the joint member 40. Thereby, contact between the engagement protrusion 30T of the input gear 30 and the front plate 12 can be prevented.

[0054] 〔Arrangement of Each Part of the Valve Opening / Closing Timing Control Device〕 In the assembled valve opening / closing timing control device 100, as shown in FIG. 1, the support wall portion 21 of the intermediate member 20 is connected to the end portion of the intake camshaft 2 by a connecting bolt 23, and these rotate integrally. The eccentric member 26 is supported by the first bearing 28 so as to be relatively rotatable about the rotation axis X with respect to the intermediate member 20. As shown in FIG. 1, the input gear 30 is supported via the second bearing 29 with respect to the eccentric support surface 26E of this eccentric member 26, and a part of the outer tooth portion 30A of this input gear 30 meshes with a part of the inner tooth portion 25A of the output gear 25.

[0055] Further, as shown in FIG. 2, the outer engagement arm 42 of the Oldham joint Cx engages with a pair of guide groove portions 11a of the outer case 11, and the engagement protrusion 30T of the input gear 30 engages with the engagement recess 43a of the inner engagement arm 43 of the Oldham joint Cx. Since the front plate 12 is disposed on the outer side of the joint member 40 of the Oldham joint Cx as shown in FIG. 1, the joint member 40 can move in a direction orthogonal to the rotation axis X while being in contact with the inner surface of the front plate 12. With this arrangement, the Oldham joint Cx is disposed outside both the first bearing 28 and the second bearing 29 (on the side far from the intake camshaft 2) and inside the front plate 12 (on the side close to the intake camshaft 2).

[0056] Then, as shown in FIG. 1, a pair of engagement pins 8 formed on the output shaft Ma of the phase control motor M engage with the engagement groove 26T of the eccentric member 26.

[0057] [Operation Mode of Phase Adjustment Mechanism] The phase control motor M is controlled by a control device 80 shown in FIG. 7. The control device 80 receives detection signals from a camshaft sensor S1 and a crankshaft sensor S2 that detect the rotation angles of the crankshaft 1 and the intake camshaft 2.

[0058] The control device 80 maintains the relative rotation phase by driving the phase control motor M at a speed equal to the rotation speed of the intake camshaft 2 during the operation of the engine E. On the other hand, an advance operation is performed by reducing the rotation speed of the phase control motor M below the rotation speed of the intake camshaft 2, and a retard operation is performed conversely by increasing the rotation speed. As described above, the intake compression ratio increases during the advance operation, and the intake compression ratio decreases during the retard operation.

[0059] The control device 80 is configured to perform oil discharge control for discharging the lubricating oil inside the valve opening / closing timing control device 100 immediately after the engine E stops. Details of this oil discharge control will be described later.

[0060] When the phase control motor M rotates at the same speed as the outer case 11 (the same speed as the intake camshaft 2), the position of the meshing portion of the outer tooth portion 30A of the input gear 30 with respect to the inner tooth 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.

[0061] 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, in the phase adjustment mechanism C, the eccentric shaft center Y revolves around the rotation shaft center X. Due to this revolution, the position of the meshing portion of the outer tooth portion 30A of the input gear 30 with respect to the inner tooth portion 25A of the output gear 25 is displaced along the inner circumference of the output gear 25, and a rotational force acts between the input gear 30 and the output gear 25. That is, a rotational force centered on the rotation shaft center X acts on the output gear 25, and a rotational force that tries to rotate the input gear 30 around the eccentric shaft center Y acts on the input gear 30.

[0062] As described above, since the engaging projection 30T of the input gear 30 engages with the engaging recess 43a of the internal engaging arm 43 of the joint member 40, the input gear 30 does not rotate with respect to the outer case 11, and the rotational force acts on the output gear 25. Due to the action of this rotational force, the intermediate member 20 rotates around the rotation shaft center X with respect to the outer case 11 together with the output gear 25. As a result, the relative rotational phase between the driving-side rotating body A and the driven-side rotating body B is set, and the setting of the opening and closing timing by the intake camshaft 2 is realized.

[0063] Also, when the eccentric shaft center Y of the input gear 30 revolves around the rotation shaft center X, along with the displacement of the input gear 30, the joint member 40 of the Oldham joint Cx is displaced in the direction in which the external engaging arm 42 extends with respect to the outer case 11, and the input gear 30 is displaced in the direction in which the internal engaging arm 43 extends.

[0064] As described above, since the number of teeth of the outer tooth portion 30A of the input gear 30 is set to be one tooth less than the number of teeth of the inner tooth portion 25A of the output gear 25, when the eccentric shaft center Y of the input gear 30 revolves around the rotation shaft center X by one revolution, the output gear 25 rotates by one tooth, realizing a large reduction ratio.

[0065] [Lubrication of the Phase Adjustment Mechanism] As shown in FIG. 1, a lubricating oil passage 15 is formed in the intake camshaft 2, through which lubricating oil from an external oil pump P (an example of a lubricating oil supply unit) is supplied via an oil passage forming member 9. A supply oil passage 21a for guiding the lubricating oil flowing through the lubricating oil passage 15 into the eccentric member 26 is formed in a part of the surface of the support wall portion 21 of the intermediate member 20 that contacts the intake camshaft 2. That is, the support wall portion 21 has a supply oil passage 21a capable of supplying lubricating oil from the outside into the inside of the driven-side rotating body B.

[0066] As described above, a gap is formed between the eccentric member 26 and the support wall portion 21 of the intermediate member 20. The supply oil passage 21a communicates with this gap.

[0067] From this configuration, the lubricating oil supplied from the oil pump P (lubricating oil supply unit) is supplied from the lubricating oil passage 15 of the intake camshaft 2 into the internal space of the intermediate member 20 through the supply oil passage 21a of the support wall portion 21 of the intermediate member 20. A part of the lubricating oil supplied to the internal space of the intermediate member 20 flows into the internal space of the eccentric member 26, but a part of it is supplied to the first bearing 28 from the gap between the eccentric member 26 and the support wall portion 21 of the intermediate member 20 by centrifugal force, and the first bearing 28 is smoothly operated (slid).

[0068] The lubricating oil supplied to the first bearing 28 is then supplied to the adjacent second bearing 29, and is supplied between the internal tooth portion 25A of the output gear 25 disposed on the outer peripheral side of the second bearing 29 and biased by the elastic member S and the outer tooth portion 30A of the input gear 30, and these parts (especially the meshing part) are smoothly operated (slid).

[0069] The lubricating oil supplied between the second bearing 29, the internal tooth portion 25A of the output gear 25, and the external tooth portion 30A of the input gear 30 is further supplied to the joint member 40. The lubricating oil supplied to the joint member 40 is supplied between the front plate 12 and the joint member 40 and is also supplied to the gap between the external engagement arm 42 of the joint member 40 and the guide groove portion 11a of the outer case 11. This enables the joint member 40 to operate smoothly.

[0070] As described above, a pair of discharge channels 11b are formed in the guide groove portion 11a (see FIGS. 2 and 3). Therefore, the lubricating oil supplied to the joint member 40 is discharged to the outside from the gap between the external engagement arm 42 of the joint member 40 and the guide groove portion 11a of the outer case 11. Also, since the discharge channels 11b are formed in the guide groove portion 11a, the internal lubricating oil can be discharged from the discharge channels 11b by centrifugal force when starting the engine E.

[0071] As shown in FIGS. 1 and 3, the front plate 12 has a circular opening 12a centered on the rotation axis X at the center. By making the opening diameter of the opening 12a larger than the inner diameter of the eccentric member 26, a step G is formed between the opening edge of the opening 12a of the front plate 12 and the inner periphery of the eccentric member 26. This step G is set to a minimum within the range where the eccentric member 26 does not contact the front plate 12 when rotating.

[0072] Due to this step G, when the engine E stops, the lubricating oil in the internal space of the eccentric member 26 is discharged from the opening 12a of the front plate 12, and the amount of lubricating oil remaining inside can be reduced.

[0073] In this way, in the valve opening / closing timing control device 100, the lubricating oil supplied inside the driven-side rotating body B is configured to be dischargeable from the guide groove portion 11a of the outer case 11 and the opening 12a of the front plate 12.

[0074] In this embodiment, as shown in FIGS. 3 and 4, on the surface of the front plate 12 facing the intermediate member 20, four convex portions 12e protruding toward the inner side (the side closer to the intake camshaft 2) are formed along the circumferential direction of the front plate 12. As shown in FIG. 4, the convex portions 12e are provided so as to face axially along the boundary between the inner peripheral surface of the outer case 11 and the outer peripheral surface of the intermediate member 20. Thereby, the flow of the lubricating oil discharged from between the outer case 11 and the intermediate member 20 is made different from the flow of the lubricating oil discharged from between the outer case 11 and the intermediate member 20 in the portion where the convex portions 12e are not provided, and the lubricating oil inside the outer case 11 can be made to flow.

[0075] Here, when the outer case 11 is rotating as described above, the lubricating oil is supplied from the supply oil passage 21a into the intermediate member 20. The valve opening / closing timing control device 100 is configured to have an oil reservoir structure Z that reduces the discharge amount of the lubricating oil discharged from the inside of the outer case 11 with respect to the supply amount of the lubricating oil supplied from the supply oil passage 21a into the intermediate member 20 during the synchronous rotation. Hereinafter, the oil reservoir structure Z will be described.

[0076] As described above, the outer engagement arm 42 of the joint member 40 is engaged with the guide groove portion 11a of the outer case 11. The guide groove portion 11a is configured such that lubricating oil is supplied thereto in order to enhance the lubricity with the outer engagement arm 42. However, since the lubricating oil that has entered the guide groove portion 11a is discharged to the outside of the outer case 11 due to the structure, in this embodiment, the amount of the lubricating oil discharged from the guide groove portion 11a is configured to be limited to a predetermined amount or less.

[0077] Specifically, the lubricating oil in the guide groove portion 11a will flow through a pair of discharge channels 11b that are formed as notches extending from the inside to the outside of the outer case 11 in each of the pair of guide groove portions 11a as shown in FIG. 5. In this embodiment, as the oil reservoir structure Z, the amount of lubricating oil discharged from the pair of discharge channels 11b is configured to be less than the amount of lubricating oil flowing through the supply oil passage 21a when the outer case 11 is rotating. Thereby, the lubricating oil supplied to the inside of the outer case 11 is made difficult to be discharged while having a lubricating function in the guide groove portion 11a.

[0078] Also, as shown in FIGS. 1 and 2, one axial side of the eccentric member 26 is inserted into an opening 12a which is an opening at the radial center of the front plate 12. In this embodiment, the front plate 12 is opened up to the position of the inserted radial outer end portion in a state where the difference between the eccentric axis Y of the eccentric member 26 with respect to the rotation axis X is the largest around the rotation axis X.

[0079] In other words, the front plate 12 closes the opening portion in the outer case 11 up to the position of the inserted radial outer end portion in a state where the difference between the eccentric axis Y of the eccentric member 26 with respect to the rotation axis X is the largest around the rotation axis X. That is, as described above, the eccentric axis Y is eccentric with respect to the rotation axis X, and the eccentric axis Y revolves around the rotation axis X. Therefore, the portion of the eccentric member 26 inserted into the front plate 12 rotates around the rotation axis X with a rotation radius obtained by adding the eccentricity of the eccentric axis Y with respect to the rotation axis X to half of the outer diameter of the portion of the eccentric member 26 inserted into the front plate 12.

[0080] The opening 12a is configured such that, when the eccentric member 26 rotates, the portion of the eccentric member 26 inserted through the front plate 12 has an inner radius equal to the sum of half of the outer diameter of the portion of the eccentric member 26 inserted through the front plate 12 with respect to the rotation axis X and the amount of eccentricity of the eccentric axis Y with respect to the rotation axis X. Also, the inner radius of the opening 12a is smaller than the inner radius of the joint member 40, and the joint member 40 is covered by the front plate 12 so that the joint member 40 cannot be visually recognized from the outside. As a result, it is possible to configure the lubricating oil to accumulate from the inner peripheral surface of the outer case 11 to the opening 12a during operation of the engine E. Such a configuration of the opening 12a also corresponds to the oil reservoir structure Z described above.

[0081] FIG. 6 shows the flow pattern of the lubricating oil in the valve opening / closing timing control device 100. In the valve opening / closing timing control device 100, lubricating oil is supplied from the oil pump P to the supply oil passage 21a via the lubricating oil passage 15 (a). When the outer case 11 is rotating, the lubricating oil supplied from the supply oil passage 21a into the intermediate member 20 flows between the inner peripheral surface of the intermediate member 20 and the outer peripheral surface of the eccentric member 26 and inside the eccentric member 26. That is, most of the lubricating oil supplied to the supply oil passage 21a flows between the eccentric member 26 and the support wall portion 21 of the intermediate member 20 due to centrifugal force and flows toward the first bearing 28 side due to centrifugal force (b). Also, a part of the lubricating oil also flows (drips) to the central portion (radial central portion) of the eccentric member 26 (h).

[0082] The lubricating oil that has flowed into the first bearing 28 flows between the inner ring 28a and the outer ring 28b (c), between the intermediate member 20 and the input gear 30 (d), and is supplied to the second bearing 29 (e). The lubricating oil that has flowed between the intermediate member 20 and the input gear 30 and the lubricating oil that has been supplied to the second bearing 29 and has flowed between the inner ring 29a and the outer ring 29b are discharged to the outside of the outer case 11 through the gap between the front plate 12 and the outer case 11 (f), but most are stored inside the outer case 11.

[0083] When the front plate 12 is viewed from the direction along the rotation axis X of the second bearing 29, it covers the region where lubricating oil flows between the inner peripheral surface of the intermediate member 20 and the outer peripheral surface of the eccentric member 26. That is, the inner peripheral surface of the opening 12a is provided at a position closer to the rotation axis X than the gap (d) between the above-described intermediate member 20 and the input gear 30 and the path (e) through which the lubricating oil is supplied to the second bearing 29. As a result, lubricating oil accumulates on the inner peripheral surface side of the outer case 11 due to centrifugal force inside the outer case 11, and the lubricating oil is discharged from the opening 12a when it reaches the opening 12a (g).

[0084] Also, the pair of discharge channels 11b are configured such that the discharge amount of lubricating oil from the pair of discharge channels 11b is less than the discharge amount of the lubricating oil that has flowed between the inner peripheral surface of the intermediate member 20 and the outer peripheral surface of the eccentric member 26. As a result, the flow rate in (a) of FIG. 6 is the sum of the flow rates in (c) and (h), and the flow rate in (f) is less than the flow rate in (c). Until the lubricating oil flows out along (g), it is possible to accumulate the lubricating oil inside the outer case 11. That is, the lubricating oil flowing in (b) flows along (c), (d), and (e), accumulates inside the outer case 11 due to centrifugal force, and is discharged along (g) when the liquid level reaches the opening 12a. At this time, the flow rate in (b) is the sum of the flow rates in (f) and (g). That is, the amount of lubricating oil discharged from the discharge channel 11b is configured to be less than the amount of lubricating oil flowing through the supply oil passage 21a minus the amount of lubricating oil flowing inside the eccentric member 26.

[0085] As a result, during the operation of the valve opening / closing timing control device 100, lubricating oil can be stored inside. Therefore, due to the damping effect of the oil (lubricating oil), the magnitude of the noise caused by the contact and collision of each part can be reduced. Accordingly, it is possible to reduce the noise and vibration emitted from the valve opening / closing timing control device 100. Further, when the valve opening / closing timing control device 100 is not operating, the lubricating oil can be discharged from the gap between the opening 12a, the front plate 12, and the outer case 11. In this way, since the lubricating oil can be discharged, for example, a decrease in the starting speed of the engine E (deterioration of the starting performance of the engine E) can be suppressed due to the viscosity of the lubricating oil at low temperatures.

[0086] 〔Control Configuration〕 FIG. 7 shows a control device 80 that functions as an ECU (engine control unit) for controlling the phase of the valve opening / closing timing control device 100. This control device 80 includes an engine start control unit 81 configured as software, an engine stop control unit 82, an oil drain control unit 83, and a phase control unit 84.

[0087] As partially described above, the control device 80 receives signals from the camshaft sensor S1, the crankshaft sensor S2, the temperature sensor S3, and the start switch SW, and outputs control signals to the starter motor 85, the engine control unit 86, and the phase control motor M.

[0088] The camshaft sensor S1 measures the rotation angle of the intake camshaft 2. The crankshaft sensor S2 measures the rotation angle of the crankshaft 1. The temperature sensor S3 measures the outside air temperature. The start switch SW starts the engine E by a manual ON operation and stops the engine E by a manual OFF operation.

[0089] The camshaft sensor S1 and the crankshaft sensor S2 are pickup-type sensors that can acquire the rotation angle from the reference rotation position as a count value with a pulse signal. With such a configuration, the phase control unit 84 acquires the relative rotation phase between the drive-side rotating body A and the driven-side rotating body B from the relative relationship of the count values of the pulse signals in the camshaft sensor S1 and the crankshaft sensor S2.

[0090] The starter motor 85 is driven in accordance with the ON operation of the start switch SW and drives the crankshaft 1 to rotate. The engine control unit 86 controls a plurality of ignition plugs 86a that ignite the air-fuel mixture in the combustion chamber of the engine E and a plurality of injectors 86b that inject fuel into the combustion chamber of the engine E.

[0091] The engine start control unit 81 drives the starter motor 85 based on the ON operation of the start switch SW, controls the valve opening / closing timing device 100 to set the opening / closing timing of the intake valve 2B to a timing suitable for combustion, injects fuel into the combustion chamber by the injector 86b after the crankshaft 1 reaches a rotational speed at which it can start, and performs ignition by the ignition plug 86a to realize the start of the engine E.

[0092] Also, the engine start control unit 81 drives the oil pump P in accordance with the control to start the engine E. This oil pump P is assumed to have a configuration in which the rotational force of the crankshaft 1 is transmitted, for example, but it may be driven by an electric motor.

[0093] The engine stop control unit 82 stops the injection of fuel by the injector 86b based on the OFF operation of the start switch SW in the situation where the engine E is operating, and stops the engine E. Also, the oil pump P stops with the stop of the engine E.

[0094] When the engine E stops under the control of the engine stop control unit 82, the oil drain control unit 83 measures the outside air temperature from the temperature sensor S3. When it is determined that the outside air temperature is 0°C or lower (an example of a predetermined value or lower), the relative rotational phase of the valve opening / closing timing control device 100 is alternately displaced on the advance angle side and the retard angle side by controlling the phase control motor M, and the lubricating oil inside the valve opening / closing timing control device 100 is discharged. The control mode of this oil drain control unit 83 will be described later. Note that the oil drain control unit 83 performs oil drain control when the outside air temperature is 0°C or lower as a predetermined value, but the predetermined value is not limited to 0°C, and any value can be set.

[0095] The phase control unit 84 calculates the relative rotational phase of the valve opening / closing timing control device 100 by acquiring the signals from the camshaft sensor S1 and the crankshaft sensor S2, and controls the phase control motor M so as to set the thus calculated relative rotational phase to the target relative rotational phase.

[0096] As described above, since lubricating oil is supplied to the valve opening / closing timing control device 100, it is also assumed that the viscosity of the internal lubricating oil increases when the outside air temperature drops after the engine E stops. When the viscosity of the lubricating oil increases in this way, it is also assumed that it takes time to set the relative rotational phase of the valve opening / closing timing control device 100 at the start of the engine E, and control is performed to discharge the lubricating oil by the oil drain control unit 83 in association with the control to stop the engine E.

[0097] 〔Control Mode〕 As shown in the flowchart of FIG. 8, when the engine E is in the operating state, the phase control unit 84 sets the target phase and performs phase control (steps #01 to #02).

[0098] The target phase is set by the control device 80 that receives a command from the upper ECU based on conditions such as the depression amount of the accelerator pedal, the load acting on the engine E, and the running speed of the vehicle. This target phase corresponds to the valve timing of the intake valve 2B. With such a setting, the phase control unit 84 performs feedback control so that the relative rotational phase obtained from the signals of the camshaft sensor S1 and the crankshaft sensor S2 reaches the target phase.

[0099] The phase control unit 84 continues the control until the start switch SW is turned off (#03 step). Also, when the start switch SW is turned off (#03 step, Yes), the engine stop control unit 82 executes control to stop the engine E (#04 step).

[0100] After the control to stop the engine E is executed in this way, when it is determined that the outside air temperature measured by the temperature sensor S3 is 0°C or less (#05 step, Yes), when the rotational speed Q per unit time of the crankshaft 1 (see FIG. 9) reaches zero ("0"), or when the oil pressure of the oil pump driven by the engine E reaches a predetermined set value or less, after confirming that the engine E has reached a completely stopped state (#06 step), drain oil control is performed to alternately displace the valve opening / closing timing control device 100 between the most advanced phase AD and the most retarded phase RE (#07 step), and then the phase control ends.

[0101] Incidentally, when the outside air temperature measured by the temperature sensor S3 in #05 step is not 0°C or less (#05 step, No), the control ends without performing the drain oil control.

[0102] A chart from the control to stop the engine E to the drain oil control (#07 step) is shown in FIG. 9. In the chart shown in FIG. 9, the rotational speed Q of the crankshaft 1 of the engine E is shown in the upper row, and the relative rotational phase R of the valve opening / closing timing control device 100 is shown in the lower row.

[0103] As shown in FIG. 9, the most advanced angle phase AD, the intermediate phase N, and the most retarded angle phase RE are shown. Also, T1 shown in FIG. 9 indicates the timing (stop start timing T1) at which the stop control of the engine E is started, T2 indicates the timing (complete stop timing T2) at which the engine E has completely stopped, and T3 indicates the timing (oil drain control start timing T3) at which the oil drain control is started.

[0104] As shown in FIG. 9, with the OFF operation of the start switch SW at the stop start timing T1, the engine stop control in step #04 is started, the rotational speed Q of the crankshaft 1 decreases, and the rotational speed Q decreases to 0 at the complete stop timing T2.

[0105] The oil drain control unit 83 drives the phase control motor M at the oil drain control start timing T3 after the lapse of the set time from the complete stop timing T2 to displace the relative rotation phase to the most advanced angle phase AD, then to the most retarded angle phase RE, and then to displace and maintain it at the intermediate phase N.

[0106] In this oil drain control (step #07), the timings at which the relative rotation phase of the valve opening / closing timing control device 100 reaches the most advanced angle phase AD and the most retarded angle phase RE are determined, and the control of the phase control motor M is performed.

[0107] By performing such oil drain control (step #07), the lubricating oil remaining inside the valve opening / closing timing control device 100 is discharged to the outside from the guide groove portion 11a of the outer case 11, and the lubricating oil is caused to flow from the engaging concave portion 43a of the joint member 40 to the opening 12a of the front plate 12 and discharged to the outside.

[0108] 〔Operational Effects of the Embodiment〕 This valve opening / closing timing control device 100 has an oil reservoir structure Z inside and is configured to enable the discharge of lubricating oil when the engine E stops. However, since the configuration that enables the discharge of lubricating oil is such that the lubricating oil inside the valve opening / closing timing control device 100 is discharged by the weight of the lubricating oil itself, it was conceivable that, for example, lubricating oil would remain in the oil reservoir structure Z.

[0109] On the other hand, as described in the embodiment, after the engine E has completely stopped due to the stop control of the engine E, the oil discharge control unit 84 controls the phase control motor M and performs control to alternately change the relative rotation phase of the valve opening / closing timing control device 100. By providing a configuration that changes the relative rotation phase in this way, lubricating oil present at the meshing portion between the internal tooth portion 25A of the output gear 25 that constitutes the phase adjustment mechanism C and the external tooth portion 30A of the input gear 30, or lubricating oil present in rotating parts such as between the inner circumference of the driving-side rotating body A and the outer circumference of the driven-side rotating body B, or in sliding parts such as the joint member 40, can be discharged.

[0110] This configuration enables the discharge of lubricating oil from regions such as the guide groove portion 11a of the outer case 11 and the opening 12a of the front plate 12 without changing the mechanical structure, such as changing the shape of the valve opening / closing timing control device 100 or adding a special mechanism, and enables good discharge of the lubricating oil remaining inside the valve opening / closing timing control device 100.

[0111] As a result, for example, when starting the engine E of a vehicle parked in a cold region, since the amount of lubricating oil remaining inside the valve opening / closing timing control device 100 is small, even if the temperature of the valve opening / closing timing control device 100 drops below freezing and the viscosity of the lubricating oil increases, when adjustment of the valve timing is required with the start of the engine E, this adjustment can be performed quickly.

[0112] Also, in this configuration, in the oil drain control (#07 step), in order to displace the relative rotation phase of the valve opening / closing timing control device 100 between the most advanced phase AD and the most retarded phase RE, the relative rotation phase is greatly changed to cause the lubricating oil remaining in the internal space of the valve opening / closing timing control device 100 to flow, and this flow force is also utilized to achieve reliable oil drainage.

[0113] 〔Alternative Embodiment〕 The present invention may be configured as follows in addition to the above-described embodiment (components having the same functions as those of the embodiment are given the same numbers and reference signs as those of the embodiment).

[0114] (a) In the oil drain control (#07 step) shown in FIG. 9, perform the operation of reciprocating the relative rotation phase of the valve opening / closing timing control device 100 between the most advanced phase AD and the most retarded phase RE two or more times. By performing such control, more reliable oil drainage can be achieved.

[0115] (b) Regardless of the outside air temperature measured by the temperature sensor S3, when stopping the engine E, set the control mode so that oil drain control is always performed. Thereby, even when the outside air temperature drops significantly after the engine E is stopped, the control of the valve opening / closing timing control device 100 can be smoothly performed at the start of the engine E.

[0116] Note that the configurations disclosed in the above-described embodiments (including alternative embodiments, the same applies hereinafter) can be applied in combination with the configurations disclosed in other embodiments as long as there is no contradiction, and the embodiments disclosed in this specification are examples, and the embodiments of the present invention are not limited thereto, and can be appropriately modified within the scope not departing from the object of the present invention.

[0117] In the above-described embodiment, the following configuration is recalled. (1) A drive-side rotating body A that rotates synchronously with the crankshaft 1 of an internal combustion engine (engine E) about the rotation axis X, a driven-side rotating body B that is coaxial with the rotation axis X and is disposed inside the drive-side rotating body A and rotates integrally with the camshaft 2 for opening and closing the valves of the internal combustion engine (engine E), a phase adjustment mechanism C having a plurality of gears for reducing the driving rotational force of an electric motor (phase control motor M) and setting the relative rotational phase between the drive-side rotating body A and the driven-side rotating body B, a lubricating oil supply unit (oil pump P) for supplying lubricating oil to the phase adjustment mechanism C from the outside, and an oil discharge control unit 83 that performs oil discharge control for changing the relative rotational phase by driving the electric motor (phase control motor M) in accordance with stop control for stopping the internal combustion engine (engine E) to discharge the lubricating oil. A valve opening / closing timing control device equipped with these components.

[0118] According to this, in accordance with the stop control for stopping the internal combustion engine (engine E), the oil discharge control unit 83 drives the electric motor (phase control motor M) to perform oil discharge control for changing the relative rotational phase of the valve opening / closing timing control device 100, thereby enabling the discharge of the lubricating oil inside the valve opening / closing timing control device 100. In particular, in order to discharge the lubricating oil present in the meshing portions of the plurality of gears that reduce the driving rotational force of the electric motor (phase control motor M), even if the viscosity of the lubricating oil increases with a decrease in temperature, the operating speed of the phase adjustment mechanism C is not decreased, and an excessive load is not applied to the electric motor (phase control motor M).

[0119] (2) In the valve opening / closing timing control device of (1), it is preferable that the oil discharge control unit 83 changes the relative rotational phase one or more times between the most retarded angle phase RE and the most advanced angle phase AD.

[0120] According to this, by changing the relative rotational phase of the valve opening / closing timing control device 100 one or more times between the most retarded angle phase RE, which is the limit on the retarded angle side, and the most advanced angle phase AD, which is the limit on the advanced angle side, it becomes possible to actively discharge the internal lubricating oil.

[0121] (3) In the valve opening / closing timing control device 100 of (1), it is preferable that the oil drain control unit 83 performs oil drain control after the rotational speed of the internal combustion engine (engine E) becomes zero or after the hydraulic pressure becomes equal to or lower than a predetermined set value.

[0122] According to this, since the oil drain control is performed after the internal combustion engine (engine E) is completely stopped or after the hydraulic pressure of lubricating oil or the like supplied from the hydraulic pump becomes equal to or lower than a predetermined set value, for example, compared with the case where the oil drain control is performed in a situation where the internal combustion engine (engine E) is rotating, it becomes possible to easily discharge the lubricating oil in a non-flowing state inside the valve opening / closing timing control device 100 by flowing down due to its own weight.

[0123] (4) In the valve opening / closing timing control device 100 of (1), it is preferable that the oil drain control unit 83 performs oil drain control only when the outside air temperature is equal to or lower than a predetermined value.

[0124] According to this, by performing the oil drain control when it is assumed that the outside air temperature is low and the viscosity of the lubricating oil inside the valve opening / closing timing control device 100 increases, it becomes possible to easily set the valve timing at the start of the internal combustion engine (engine E). On the other hand, since the oil drain control is not performed when the outside air temperature is high, electrical energy is not wasted.

Industrial Applicability

[0125] The present invention can be used for a valve opening / closing timing control device.

Explanation of Reference Numerals

[0126] 1: Crankshaft, 2: Intake camshaft (camshaft), 83: Oil drain control unit, A: Driving side rotating body, B: Driven side rotating body, C: Phase adjustment mechanism, E: Engine (internal combustion engine), P: Oil pump (lubricating oil supply unit), X: Rotation axis center

Claims

1. A driving-side rotating body that rotates synchronously with the crankshaft of an internal combustion engine about a rotation axis; A driven-side rotating body that is coaxial with the rotation axis and is disposed inside the driving-side rotating body and rotates integrally with a camshaft for opening and closing valves of the internal combustion engine; A phase adjustment mechanism having a plurality of gears for reducing the driving rotational force of an electric motor and setting a relative rotational phase between the driving-side rotating body and the driven-side rotating body; A lubricating oil supply unit that supplies lubricating oil to the phase adjustment mechanism from the outside, and an oil discharge control unit that performs oil discharge control to change the relative rotational phase by driving the electric motor and discharge the lubricating oil in accordance with stop control for stopping the internal combustion engine. A valve opening / closing timing control device.

2. The valve opening / closing timing control device according to claim 1, wherein the oil discharge control unit changes the relative rotational phase one or more times between a most retarded phase and a most advanced phase.

3. The valve opening / closing timing control device according to claim 1, wherein the oil discharge control unit performs the oil discharge control after the rotational speed of the internal combustion engine becomes zero or after the oil pressure becomes equal to or lower than a predetermined set value.

4. The valve opening / closing timing control device according to claim 1, wherein the oil discharge control unit performs the oil discharge control only when the outside air temperature is equal to or lower than a predetermined value.

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