JP6645238B2 - Eccentric oscillating reduction gear - Google Patents

Description

  The present invention relates to an eccentric oscillating reduction gear.

  2. Description of the Related Art Conventionally, as described in Patent Document 1, there is known an eccentric oscillating reduction gear device that eccentrically rotates with a phase difference of 180 degrees between two rotating bodies housed in a container-shaped rotating member. When two rotating bodies are used, vibration or noise may occur. In order to suppress vibration or noise, as disclosed in Japanese Patent Application Laid-Open No. H11-163, there is a configuration in which three rotating bodies are provided to be accommodated in a container-shaped rotating member.

JP 2009-257493 A JP-A-2000-120809

  When three rotating bodies are used as in the configuration of Patent Literature 2, the cost increases due to an increase in the size of the eccentric oscillating type speed reducer in the axial direction and an increase in the number of parts in the eccentric oscillating type speed reducer. . In order to reduce the cost of the eccentric oscillating reduction gear, it is conceivable to reduce the number of rotating bodies accommodated in the rotating member, to reduce the size and the number of parts. However, when the number of rotating bodies is reduced and two rotating bodies are used, a rotating moment (couple) acts on the two rotating bodies. As a result, the axes of the two rotating bodies are shifted, and there is a possibility that vibration or noise may be generated due to friction between the two rotating bodies.

  The present invention has been made in view of such a point, and an object of the present invention is to provide an eccentric oscillating reduction gear that can suppress generation of vibration and noise and can be reduced in size.

An eccentric oscillating reduction gear according to the present invention includes a first rotating body (20), a second rotating body (40), a third rotating body (70), and an engagement member (74).
The first rotating body is rotatable and in a container shape.
The second rotating body is housed in the first rotating body, has at least one engagement hole (43), and is rotatable.

The third rotating body is accommodated in the first rotating body so as to face the second rotating body, and the first rotating body and the second rotating body are connected so as to be able to transmit rotation.
Further, the third rotator rotates eccentrically with respect to the axis of the first rotator and the second rotator, thereby changing the relative rotation phase between the first rotator and the second rotator. The rotation of the rotating body or the second rotating body can be accelerated / decelerated.
At least one engaging member is provided, and engages the second rotating body and the third rotating body via the engaging hole.

In the side surfaces of the engagement member, one surface is defined as a reference side surface (82), and a side surface facing the reference side surface is defined as an opposite side surface (83).
At least one engagement member has an attractive surface (80) whose reference side surface and opposite side surface are symmetrically inclined with respect to the axial direction of the engagement member.
The second rotator includes an inner wall surface of the engagement hole, and has a contact surface (81) on the inner surface of the second rotator that contacts the attraction surface. The contact surface is formed along the attraction surface. The maximum diameter (D1) of the engagement member is smaller than the minimum diameter (D2) of the engagement hole. At least a part of the contact portion between the attractive surface and the contact surface is engaged from the third rotating body toward the second rotating body such that a force acts in a direction in which the second rotating body and the third rotating body attract each other during rotation. The joining member is formed so that the diameter of the joining member increases.

  With such a configuration, a force acts in a direction in which the second rotator and the third rotator are attracted, so that the second rotator and the third rotator are held in parallel. Thereby, the friction between the second rotating body and the third rotating body becomes smooth, and vibration or noise can be suppressed. Furthermore, in order to suppress vibration or noise, it is not necessary to increase the number of rotating bodies, and the number of parts can be reduced. Therefore, the eccentric oscillating reduction gear can be reduced in size.

FIG. 1 is a schematic diagram of a valve timing adjustment device using an eccentric oscillating reduction gear according to a first embodiment of the present invention. FIG. 1 is a vertical sectional view of an eccentric oscillating speed reduction device according to a first embodiment of the present invention. FIG. 2 is a sectional view of the second rotator and the third rotator taken along the line III-III. The IV section enlarged view of FIG. The V section enlarged view of FIG. FIG. 6 is a sectional view of an engagement member according to a second embodiment of the present invention. FIG. 7 is a sectional view of an eccentric oscillating reduction gear according to a third embodiment of the present invention. The enlarged view of the engagement member of other embodiments. Sectional drawing of the eccentric oscillating reduction gear of other embodiment.

  Hereinafter, an eccentric oscillating reduction gear according to an embodiment of the present invention will be described with reference to the drawings. In the description of the plurality of embodiments, the same reference numerals are given to substantially the same configuration as the first embodiment, and the description will be omitted. Further, the "first embodiment" includes the first to third embodiments. The eccentric oscillating reduction gears of these embodiments are used, for example, in a valve timing adjustment device of an internal combustion engine that adjusts the valve timing of at least one of an intake valve and an exhaust valve.

The valve timing adjustment device 10 used in the eccentric oscillating reduction gear device 50 of the present embodiment will be described.
As shown in FIG. 1, a crank gear 3 fixed to a crankshaft 2 as a drive shaft of the internal combustion engine 1 and a first eccentric oscillating reduction gear 50 fixed to camshafts 4 and 5 as driven shafts. The chain 7 is wound around the rotating body 20. Torque is transmitted from the crankshaft 2 to the camshafts 4 and 5 via the chain 7. One camshaft 4 drives an intake valve 8 and the other camshaft 5 drives an exhaust valve 9. The valve timing adjusting device 10 of the present embodiment adjusts the opening / closing timing of the intake valve 8 or the exhaust valve 9 by changing the relative rotation phase between the crankshaft 2 and the camshafts 4 and 5. The eccentric oscillating reduction gear transmission 50 of the present embodiment is used to change the relative rotation phase between the crankshaft 2 and the camshafts 4 and 5.

  The valve timing adjustment device 10 is configured to rotate the camshafts 4 and 5 relative to the first rotating body 20 that rotates integrally with the crankshaft 2 in the same rotation direction as the crankshaft 2 so that the intake valve 8 or the exhaust valve Advance the valve timing of No. 9. The relative rotation of the camshafts 4 and 5 so that the valve timing of the intake valve 8 or the exhaust valve 9 is advanced is referred to as “advancing”.

  Further, the valve timing adjustment device 10 delays the valve timing of the intake valve 8 or the exhaust valve 9 by the relative rotation of the camshafts 4 and 5 in the rotation direction opposite to the crankshaft 2. The relative rotation of the camshafts 4 and 5 so that the valve timing of the intake valve 8 or the exhaust valve 9 is delayed is referred to as “retarding”.

(1st Embodiment)
As shown in FIG. 2, the eccentric oscillating speed reduction device 50 includes a first rotator 20, a second rotator 40, a control unit 60, and a third rotator 70.
The first rotating body 20 is rotatably formed in a container shape in which a bottomed cylindrical gear member 21 and a bottomed cylindrical sprocket 22 are coaxially combined. The first rotating body 20 is provided coaxially with one camshaft 4 or the other camshaft 5.

The gear member 21 has a protrusion 23 and a first internal gear 24.
The protruding portion 23 is formed on the outer wall of the gear member 21 so as to protrude from the radial inside to the radial outside of the gear member 21.
The first internal gear portion 24 is formed on the inner peripheral wall of the gear member 21 such that the addendum circle goes radially inward of the gear member 21 from the root circle.

The sprocket 22 has a large diameter portion 25 and a small diameter portion 26.
The large diameter portion 25 is fitted with the protrusion 23 and the screw 27, and the gear member 21 and the sprocket 22 are integrally connected.

  The small diameter portion 26 is provided with a plurality of sprocket teeth 29 projecting from the radially inner side to the radially outer side, and the chain 7 is wound around the plurality of sprocket teeth 29 and the crank gear 3. When the torque output from the crankshaft 2 is input to the sprocket 22 via the chain 7, the first rotating body 20 rotates about the rotation axis O in conjunction with the crankshaft 2. At this time, the rotation direction of the first rotating body 20 is the counterclockwise direction in FIG. 1 in the present embodiment.

The second rotating body 40 is housed in the first rotating body 20 and is formed in a disk shape, and has a central hole 44 in the center of which the sleeve bolt 41 is inserted. The second rotating body 40 is provided coaxially with the first rotating body 20, and is connected and fixed to one camshaft 4 or the other camshaft 5 by a sleeve bolt 41. Further, the second rotating body 40 can rotate around the rotation axis O while maintaining a relative rotation phase with respect to the cam shafts 4 and 5 in conjunction with the cam shafts 4 and 5. The second rotating body is supported inside the large-diameter portion 25, and is rotatable relative to the first rotating body 20. Further, the second rotating body 40 has an engagement hole 43.
As shown in FIG. 3, eight engagement holes 43 are formed inside the second rotating body 40 with a circular cross section in the axial direction.

The control unit 60 includes an electric motor 61 and a control circuit 62.
The electric motor 61 is, for example, a permanent magnet synchronous type three-phase AC motor, and is provided on the opposite side of the first rotating body 20 and the second rotating body 40 from the cam shafts 4 and 5. The electric motor 61 is housed in a motor case 63 and has a motor shaft 64. The motor shaft 64 is supported by the motor case 63 so as to be able to rotate forward and backward.

  The control circuit 62 is mainly configured by a microcomputer, and is provided outside or inside the motor case 63. The processing in the control circuit 62 may be software processing by executing a program stored in a substantial memory device such as a ROM in advance by a CPU, or hardware processing by a dedicated electronic circuit. .

  The control circuit 62 is connected to the electric motor 61 and controls the electric motor 61 according to the operation state of the internal combustion engine 1. The controlled electric motor 61 generates a rotating magnetic field around the motor shaft 64 and outputs a rotating torque from the motor shaft 34 in the advance direction X and the retard direction Y according to the direction of the rotating magnetic field.

The third rotator 70 is housed in the first rotator 20 and provided to face the second rotator 40. Further, the third rotating body 70 is formed in a cylindrical shape, and the third rotating body 70 and the motor shaft 64 are connected and fixed. The third rotating body 70 rotates with the rotating shaft O in conjunction with the motor shaft 64. It is rotatable around.
The third rotating body 70 has a third external gear 71, an eccentric part 72, a spring 73 as an "biasing member", and an engaging member 74.

  The third external gear portion 71 is formed on the outer peripheral wall of the third rotating body 70 so that the tip circle goes radially outward from the root circle. The number of teeth of the third external gear portion 71 is set smaller than the number of teeth of the first internal gear portion 24, and the outer peripheral wall of the third external gear portion 71 is fitted with the inner peripheral wall of the first internal gear portion 24. ing. Thus, the third rotating body 70 is supported so as to be rotatable relative to the first rotating body 20. A fitting portion between the third external gear portion 71 and the first internal gear portion 24 is a fixing portion 75.

  The eccentric portion 72 is formed in a cylindrical shape whose outer peripheral wall is eccentric toward the fixed portion 75 with respect to the rotation axis O, and has a central hole 76 in the center where the motor shaft 64 is inserted. The eccentric part 72 supports the gear member 21 from the inner peripheral side of the center hole 76 via a bearing 77. Further, the eccentric portion 72 has the third external gear portion 71 through the bearing 78 from the inner peripheral side of the center hole 76. With this support, the third rotating body 70 can rotate around the eccentric axis P which is the center axis of the outer peripheral wall of the eccentric part 72 and can revolve around the rotating axis O. Therefore, the third rotating body 70 is capable of planetary movement, that is, eccentrically rotatable with respect to the rotation axis O of the first rotating body 20 and the second rotating body.

  The spring 73 is provided between the eccentric part 72 and the bearing 78 on the fixed part 75 side. The spring 73 presses the third rotating body 70 against the gear member 21 by urging the third rotating body 70 toward the fixed portion 75 via a bearing 78. Further, an engagement member 74 described below is pressed against the second rotating body 40.

  As shown in FIG. 4, the engagement member 74 is formed integrally with the third rotating body 70 so as to project from the end face 79 of the third rotating body 70 toward the second rotating body 40. The engaging member 74 is inserted into the engaging hole 43, and the outer surface of the engaging member 74 and the inner surface of the second rotating body 40 in the engaging hole 43 are fitted. The engaging member 74 and the engaging hole 43 are fitted with a gap therebetween in the radial direction, and the first rotating body 20 and the second rotating body 40 are connected. The maximum diameter of the engagement member 74 is D1, and the minimum diameter of the engagement hole 43 is D2. The engagement member 74 is formed such that the maximum diameter D1 is smaller than the minimum diameter D2 of the engagement hole 43, that is, D1> D2.

(Action)
The operation of the eccentric oscillating reduction gear device 50 of the present embodiment will be described.
When the motor shaft 64 does not rotate relative to the first rotator 20, the third rotator 70 rotates together with the first rotator 20 and the second rotator 40 while maintaining the meshing position with the first rotator 20. . At this time, since the relative rotation phase between the first rotating body 20 and the second rotating body 40 is maintained, the valve timing is maintained.

  When the motor shaft 64 rotates relative to the first rotating body 20 in the advance direction X, a rotational torque is generated from the motor shaft 64 in the advance direction X. At this time, while the meshing position between the third rotating body 70 and the first rotating body 20 changes, the second rotating body 40 advances with respect to the first rotating body 20 due to the planetary movement of the third rotating body 70. Relative rotation in the angular direction X. The rotation of the second rotating body 40 is accelerated, and the valve timing of the intake valve 8 or the exhaust valve 9 is advanced.

  When the motor shaft 64 outputs rotational torque in the retard direction Y, or when the electric motor 61 stops suddenly, while the meshing position between the third rotating body 70 and the first rotating body 20 is changed, The three rotating bodies 70 perform a planetary motion. At this time, the second rotating body 40 relatively rotates in the retard direction Y with respect to the first rotating body 20. The rotation of the second rotating body 40 is reduced, and the valve timing of the intake valve 8 or the exhaust valve 9 is delayed.

  As described above, the third rotating body 70 is connected to the first rotating body 20 and the second rotating body 40 so as to be able to transmit the rotation, and the third rotating body 70 performs the planetary motion, whereby the first rotating body 20 and the second rotating body 40 are connected. The relative rotation phase with respect to the rotating body 40 changes. When the relative rotation phase changes, the rotation of the second rotating body 40 is accelerated / decelerated, and the valve timing of the intake valve 8 or the exhaust valve 9 is adjusted.

  Conventionally, when the second rotating body and the third rotating body accommodated in the first rotating body are used, a couple acts on the two rotating bodies, the axes of the two rotating bodies are shifted, and the second rotating body and the third rotating body are shifted. Sometimes the three rotating bodies did not become parallel. When the third rotator performs a planetary motion in a state where the second rotator and the third rotator are not parallel to each other, the second rotator and the third rotator rub against each other while hitting each other. Had occurred. Further, there is a configuration in which three rotating bodies are provided as described in Patent Literature 2 in order to suppress vibration or noise, but there is a concern that the number of parts is increased and cost is increased.

  Therefore, in the present embodiment, in order to suppress vibration and noise and reduce the number of components of the eccentric oscillating reduction gear, "a certain device" is used in the second rotating body 40 and the third rotating body 70. . Hereinafter, the characteristic configuration in the present embodiment will be described.

(Feature configuration)
As shown in FIG. 5, the engaging member 74 that engages the second rotating body 40 and the third rotating body 70 has an attractive surface where a force acts in a direction in which the second rotating body 40 and the third rotating body 70 are attracted. 80 is formed on the side surface. One of the side surfaces of the engaging member 74 is referred to as a reference side surface 82, and a surface facing the reference side surface 82 is referred to as an opposing side surface 83.

The attractive surface 80 is formed on the side surface of the engaging member 74 such that the reference side surface 82 and the opposing side surface 83 facing each other are inclined symmetrically with respect to the axial direction of the engaging member 74. The second rotating body 40 has a contact surface 81 that is in contact with the attraction surface 80 on the inner side surface of the second rotating body 40.
The contact surface 81 is formed along the attractive surface 80.

  The attraction surface 80 is formed in a tapered shape that is inclined in a direction in which the diameter of the engaging member 74 increases from the third rotating body 70 toward the second rotating body 40. The engagement hole 43 is formed so as to be inclined in a direction in which the diameter of the engagement hole 43 increases from the third rotating body 70 toward the second rotating body 40. Thereby, the contact surface 81 is formed so as to be inclined in the same direction as the attraction surface 80.

  The presence of the attractive surface 80 exerts a force in a direction in which the second rotating body 40 and the third rotating body 70 attract each other. Since the attractive surface 80 is inclined, the force F received by the attractive surface 80 from the contact surface 81 can be decomposed into the axial component force Ft and the radial component force Fd. The axial component force Ft is a force acting in a direction from the third rotating body 70 to the second rotating body 40. Thereby, the second rotating body 40 and the third rotating body 70 attract each other.

(effect)
[1] Since the attraction surface 80 is formed on the side surface of the engagement member 74, a force acts in a direction in which the second rotator 40 and the third rotator 70 are attracted. Due to this attractive force, the second rotating body 40 and the third rotating body 70 are held in parallel. Thereby, when the third rotating body 70 performs a planetary motion, the friction with the second rotating body 40 becomes smooth without colliding, and vibration or noise can be suppressed. Furthermore, in order to suppress vibration or noise, it is not necessary to increase the number of rotating bodies, and the number of parts can be reduced. Therefore, the eccentric oscillating reduction gear transmission 50 can be reduced in size.

  Further, since the engaging member 74 is pressed against the second rotating body 40 by the urging force of the spring 73, the force F received by the attractive surface 80 from the contact surface 81 increases. For this reason, the force Ft of the axial component increases, and the attractive force acting on the second rotating body 40 and the third rotating body 70 increases. Therefore, the provision of the spring 73 makes it easier for the second rotating body 40 and the third rotating body 70 to be parallel.

  [2] Since the maximum diameter D1 of the engagement member 74 is smaller than the minimum diameter D2 of the engagement hole 43, the engagement member 74 is easily inserted into the engagement hole 43. Therefore, the gear member 21 that houses the third rotating body 70 and the sprocket 22 that houses the second rotating body 40 are easily assembled.

(2nd Embodiment)
The configuration of the second embodiment is the same as that of the first embodiment except for the forms of the attractive surface and the contact surface.
As shown in FIG. 6, the attractive surface 120 is formed so as to curve from the radially inner side to the radially outer side of the engaging member 74. Further, the contact surface 121 is formed to be curved along the attraction surface 120. The second embodiment has the same effects as the first embodiment. Further, since the attractive surface 120 is curved, a contact area with the contact surface 121 is increased. As the contact area increases, the surface pressure due to the force acting on the attractive surface 120 and the contact surface 121 decreases, and the durability of the engagement member 74 and the second rotating body 40 can be improved.

(Third embodiment)
The configuration of the third embodiment is the same as that of the first embodiment except for the forms of the third rotating body and the engagement member.
As shown in FIG. 7, the third rotating body 130 has an insertion hole 131 corresponding to the engagement hole 43. The engagement member 133 is inserted into the insertion hole 131.
The engagement member 133 is formed in a round bar shape and is separate from the third rotating body 130. In FIG. 7, the engaging member 133 is described in a dot pattern in order to clarify the engaging member 133. The engaging member 133 has an attractive surface 134 as in the first embodiment. The third embodiment has the same advantages as the first embodiment.

(Other embodiments)
(I) At least one engaging member and at least one engaging hole may be formed. The same effects as in the first embodiment can be obtained without being limited to the number of the engagement members and the engagement holes.

  (Ii) In another embodiment that shares the concept of the second embodiment, as shown in FIG. 8, the attraction surface 122 extends radially outward from the end surface 79 of the third rotating body 70 to the center of the engaging member 74. And is formed so as to be curved radially inward. Further, the attractive surface 122 is formed so as to be curved from the radial outside to the radial inside from the center of the engaging member 74 to the end surface 174 of the engaging member 74. The contact surface 123 is formed so as to be curved along the attractive surface 122. In FIG. 8, the curved portion is exaggerated for easy understanding of the characteristic configuration. In such a configuration, the same effects as those of the second embodiment can be obtained.

(Iii) In another embodiment sharing the idea of the third embodiment, the idea of the first embodiment may be combined with the third embodiment, as shown in FIG. Both the round bar-shaped engaging member 133 and the engaging member 144 provided so as to project from the end face 143 of the third rotating body 140 toward the second rotating body 40 may be formed.
As described above, the present invention is not limited to such an embodiment, and can be implemented in various forms without departing from the spirit of the invention.

20 ... first rotating body,
40 ... second rotating body,
43 ... engagement hole
70 ... third rotating body,
74 engagement members,
80 ・ ・ ・ attraction surface
81 ... contact surface,
82 ... reference side surface,
83 ··· Opposite side surface.

Claims (3)

A rotatable container-like first rotator (20);
A second rotating body (40) housed in the first rotating body, having at least one engagement hole (43), and being rotatable;
The first rotator is accommodated in the first rotator so as to face the second rotator, and the first rotator and the second rotator are connected so as to be able to transmit rotation. The third rotator (70) capable of changing the relative rotation phase between the first rotator and the second rotator by eccentric rotation and capable of accelerating and decelerating the rotation of the first rotator or the second rotator. )When,
At least one engaging member (74) for engaging the second rotating body and the third rotating body via the engaging hole;
With
One of the side surfaces of the engagement member is set as a reference side surface (82),
Assuming that a surface facing the reference side surface is a facing side surface (83),
At least one of the engagement members has an attractive surface (80) in which the reference side surface and the opposite side surface are symmetrically inclined with respect to an axial direction of the engagement member.
The second rotating body includes an inner wall surface of the engagement hole, and has a contact surface (81) that is in contact with the attraction surface on an inner surface of the second rotating body.
The contact surface is formed along the attraction surface,
Maximum diameter (D1) in the engaging member, rather smaller than the minimum diameter (D2) in said engagement hole,
At least a part of the contact portion between the attraction surface and the contact surface is separated from the third rotator so as to exert a force in a direction in which the second rotator and the third rotator attract each other during rotation. An eccentric oscillating type speed reducer formed so that the diameter of the engaging member increases toward the rotating body . The attraction surface is formed to be at least partially curved,
The eccentric oscillating reduction gear according to claim 1, wherein the contact surface is formed to be curved along the attraction surface. An eccentric oscillating type reduction gear transmission according to claim 1 or 2 ,
A crankshaft (2) rotatable in conjunction with the first rotating body;
A camshaft (4) rotatable in conjunction with the second rotating body;
With
A valve timing adjusting device for an internal combustion engine (1) for adjusting at least one valve timing of an intake valve (8) and an exhaust valve (9) that open and close the camshaft by rotation transmission from the crankshaft.

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