JP2017141752A - Eccentric oscillation-type reduction gear - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an eccentric oscillation-type reduction gear which suppresses the generation of vibration and noise, and is reducible in size.SOLUTION: An eccentric oscillation-type reduction gear comprises a second rotating body 40, a third rotating body 70 and an engagement member 74. The second rotating body 40 has at least one engagement hole 43. The third rotating body 70 can change a relative rotation phase between a first rotating body and the second rotating body 40 by being eccentrically rotated. The engagement member 74 makes the second rotating body 40 and the third rotating body 70 engaged with each other via the engagement hole 43, and has an attraction face 80 whose opposing side faces are symmetrically inclined. The second rotating body 40 has a contact face 81 contacting with the attraction face 80 at an inside face. When the attraction face 80 contacts with the contact face 81, a force acts in a direction in which the second rotating body 40 and the third rotating body 70 attract each other. By this constitution, the second rotating body 40 and the third rotating body 70 are held in parallel with each other, and vibration or noise can be suppressed. Furthermore, the number of part items can be decreased, and a size can be reduced.SELECTED DRAWING: Figure 5

Description

  The present invention relates to an eccentric oscillating speed reducer.

  2. Description of the Related Art Conventionally, as described in Patent Document 1, an eccentric oscillating speed reduction device that rotates eccentrically with two rotating bodies housed in a container-shaped rotating member being 180 degrees out of phase is known. When two rotating bodies are used, vibration or noise may occur. In order to suppress vibration or noise, as disclosed in Patent Document 2, there is one provided with three rotating bodies accommodated in a container-shaped rotating member.

JP 2009-257493 A JP 2000-120809 A

  When three rotating bodies are used as in the configuration of Patent Document 2, the cost increases due to an increase in the size of the eccentric oscillating speed reducer in the axial direction and an increase in the number of parts in the eccentric oscillating speed reducer. . In order to reduce the cost of the eccentric oscillating speed reducer, it is possible to reduce the number of rotating bodies accommodated in the rotating member, and 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 rotational moment (couple) acts on the two rotating bodies. Thereby, the axis | shafts of two rotary bodies shift | deviate and there exists a possibility that a vibration or noise may generate | occur | produce by the friction by two rotary bodies.

  The present invention was created in view of the above points, and an object of the present invention is to provide an eccentric oscillating speed reduction device that can suppress the generation of vibration and noise and can be downsized.

The eccentric oscillating speed reduction device according to the present invention includes a first rotating body (20), a second rotating body (40), a third rotating body (70), and an engaging member (74).
The first rotating body is rotatable and has a container shape.
The second rotating body is accommodated 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 coupled so as to be able to transmit rotation.
In addition, the third rotating body rotates eccentrically with respect to the axes of the first rotating body and the second rotating body, thereby changing the relative rotational phase between the first rotating body and the second rotating body. 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.

Of the side surfaces of the engaging member, one surface is a reference side surface (82), and a side surface facing the reference side surface is an opposing side surface (83).
The at least one engagement member has an attractive force surface (80) in which the reference side surface and the opposite side surface are symmetrically inclined with respect to the axial direction of the engagement member.
The second rotating body has a contact surface (81) that contacts the attractive surface on the inner surface of the second rotating body. The contact surface is formed along the attractive surface.
When the attractive surface comes into contact with the contact surface, a force acts in a direction in which the second rotating body and the third rotating body attract each other.

  By configuring in this way, a force acts in the direction in which the second rotating body and the third rotating body are attracted, so that the second rotating body and the third rotating body 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 speed reduction device can be reduced in size.

1 is a schematic view of a valve timing adjusting device in which an eccentric oscillating speed reduction device according to a first embodiment of the present invention is used. The longitudinal cross-sectional view of the eccentric rocking | swiveling type reduction gear device by 1st Embodiment of this invention. Sectional drawing of the 2nd rotary body and the 3rd rotary body in the III-III line in FIG. The IV section enlarged view of FIG. The V section enlarged view of FIG. Sectional drawing of the engaging member by 2nd Embodiment of this invention. Sectional drawing of the eccentric rocking | fluctuation type deceleration device by 3rd Embodiment of this invention. The enlarged view of the engaging member of other embodiment. Sectional drawing of the eccentric rocking | fluctuation type deceleration device of other embodiment.

  Hereinafter, an eccentric oscillating speed reduction device according to an embodiment of the present invention will be described with reference to the drawings. In description of several embodiment, the same code | symbol is attached | subjected to the structure substantially the same as 1st Embodiment, and description is abbreviate | omitted. In addition, the term “this embodiment” encompasses the first to third embodiments. The eccentric oscillating speed reducer of these embodiments is used, for example, in a valve timing adjusting device for an internal combustion engine that adjusts the valve timing of at least one of an intake valve and an exhaust valve.

The valve timing adjusting device 10 used in the eccentric oscillating speed reduction 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 of an eccentric oscillating speed reduction device 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 this embodiment adjusts the opening / closing timing of the intake valve 8 or the exhaust valve 9 by changing the relative rotational phase of the crankshaft 2 and the camshafts 4, 5. The eccentric oscillating speed reduction device 50 according to the present embodiment is used to change the relative rotational phase between the crankshaft 2 and the camshafts 4 and 5.

  The valve timing adjusting device 10 is configured so that the cam shafts 4 and 5 rotate relative to the first rotating body 20 that rotates integrally with the crankshaft 2 in the same rotational direction as the crankshaft 2, whereby the intake valve 8 or the exhaust valve. 9 The valve timing is advanced. Thus, 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 “advance”.

  Further, the valve timing adjusting 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. Thus, 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”.

(First embodiment)
As shown in FIG. 2, the eccentric oscillating speed reduction device 50 includes a first rotating body 20, a second rotating body 40, a control unit 60, and a third rotating body 70.
The first rotating body 20 is formed to be rotatable 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 includes a protruding portion 23 and a first internal gear portion 24.
The protrusion 23 is formed on the outer wall of the gear member 21 so as to protrude from the radially inner side of the gear member 21 to the radially outer side.
The first internal gear portion 24 is formed on the inner peripheral wall of the gear member 21 such that the tip circle is directed 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 by a protrusion 23 and a screw 27, and the gear member 21 and the sprocket 22 are integrally coupled.

  The small diameter portion 26 is provided with a plurality of sprocket teeth 29 protruding 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 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 of FIG. 1 in the present embodiment.

The second rotating body 40 is accommodated in the first rotating body 20 and is formed in a disc shape, and a center hole 44 into which the sleeve bolt 41 is inserted is formed at the center. 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. 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. In addition, the second rotating body is supported inside the large-diameter portion 25 and can rotate relative to the first rotating body 20. Further, the second rotating body 40 has an engagement hole 43.
As shown in FIG. 3, eight engaging holes 43 have a circular cross section in the axial direction and are formed in the second rotating body 40.

The control unit 60 includes an electric motor 61 and a control circuit 62.
The electric motor 61 is, for example, a permanent magnet type synchronous three-phase AC motor, and is provided on the opposite side of the cam shafts 4 and 5 with the first rotating body 20 and the second rotating body 40 interposed therebetween. The electric motor 61 is accommodated 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 composed of a microcomputer, and is provided outside or inside the motor case 63. The processing in the control circuit 62 may be software processing by a CPU executing a program stored in advance in a substantial memory device such as a ROM, or may be 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 operating state of the internal combustion engine 1. The electric motor 61 to be controlled generates a rotating magnetic field around the motor shaft 64 and outputs rotational torque from the motor shaft 34 in the advance angle direction X and the retard angle direction Y according to the direction of the rotation magnetic field.

The third rotating body 70 is accommodated in the first rotating body 20 and is provided to face the second rotating body 40. The third rotator 70 is formed in a cylindrical shape, and the third rotator 70 and the motor shaft 64 are connected and fixed. The third rotator 70 is coupled to the motor shaft 64 to rotate the rotation axis O. It can be rotated around.
The third rotating body 70 includes a third external gear portion 71, an eccentric portion 72, a spring 73 as an “urging 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 such that the tip circle is directed radially outward from the root circle. The number of teeth of the third external gear portion 71 is set to be 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. Accordingly, 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 fixed portion 75.

  The eccentric part 72 is formed in a cylindrical shape whose outer peripheral wall is eccentric to the fixed part 75 side with respect to the rotation axis O, and a central hole 76 into which the motor shaft 64 is inserted is formed at the center. The eccentric portion 72 supports the gear member 21 from the inner peripheral side of the center hole 76 through a bearing 77. In addition, 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 about the eccentric axis P, which is the central axis of the outer peripheral wall of the eccentric portion 72, and can revolve around the rotation axis O. Therefore, the third rotating body 70 is capable of planetary movement, that is, eccentrically rotatable with respect to the rotation axis O in the first rotating body 20 and the second rotating body.

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

  As shown in FIG. 4, the engaging member 74 is formed integrally with the third rotating body 70 so as to protrude from the end surface 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 so that the maximum diameter D1 is smaller than the minimum diameter D2 of the engagement hole 43, that is, D1> D2.

(Function)
The operation of the eccentric oscillating speed reduction device 50 of this embodiment will be described.
When the motor shaft 64 does not rotate relative to the first rotating body 20, the third rotating body 70 rotates together with the first rotating body 20 and the second rotating body 40 while maintaining the meshing position with the first rotating body 20. . At this time, since the relative rotational 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 angle direction X, rotational torque is generated from the motor shaft 64 in the advance angle direction X. At this time, the meshing position between the third rotating body 70 and the first rotating body 20 changes, and the third rotating body 70 moves in a planetary motion, so that the second rotating body 40 advances relative to the first rotating body 20. 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 retarding direction Y, or when the electric motor 61 stops suddenly, the meshing position of the third rotating body 70 and the first rotating body 20 changes, and the first The three-rotor 70 moves in a planetary motion. At this time, the second rotating body 40 rotates relative to the first rotating body 20 in the retarding direction Y. The rotation of the second rotating body 40 is decelerated, 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 so as to be able to transmit the rotation between the first rotating body 20 and the second rotating body 40, and the third rotating body 70 performs a planetary motion, thereby the first rotating body 20 and the second rotating body 70. The relative rotational phase with the rotating body 40 changes. When the relative rotation phase changes, the rotation of the second rotating body 40 is accelerated and 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 housed in the first rotating body are used, a couple acts on the two rotating bodies, the axes of the two rotating bodies are displaced, and the second rotating body and the second rotating body are displaced. In some cases, the three-rotor was not parallel. When the second rotating body and the third rotating body move in a planetary motion in a state where the second rotating body and the third rotating body are not parallel, the second rotating body and the third rotating body rub against each other, so that vibration or noise is generated. It has occurred. Moreover, in order to suppress vibration or noise, there is also a configuration in which three rotating bodies are provided as described in Patent Document 2, but there is a possibility that the number of parts becomes large and high cost is caused.

  Therefore, in the present embodiment, in order to suppress vibration and noise and reduce the number of parts of the eccentric oscillating speed reduction device, “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 on which a force acts in the 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 a reference side surface 82, and a surface facing the reference side surface 82 is 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 contacts the attractive surface 80 on the inner surface of the second rotating body 40.
The contact surface 81 is formed along the attractive surface 80.

  The attractive 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. Further, the engagement hole 43 is formed so as to incline 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 to be inclined in the same direction as the attractive surface 80.

  Due to the presence of the attractive surface 80, a force acts 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 an axial component force Ft and a radial component force Fd. The axial component force Ft is a force acting in a direction from the third rotating body 70 toward the second rotating body 40. Thereby, the 2nd rotary body 40 and the 3rd rotary body 70 attract.

(effect)
[1] Since the attractive force surface 80 is formed on the side surface of the engaging member 74, a force acts in a direction in which the second rotating body 40 and the third rotating body 70 are attracted. Due to this attractive force, the second rotating body 40 and the third rotating body 70 are held in parallel. As a result, when the third rotating body 70 performs a planetary motion, the friction with the second rotating body 40 becomes smooth without hitting, 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 speed reduction device 50 can be reduced in size.

  Further, since the engaging member 74 is pressed against the second rotating body 40 by the biasing force of the spring 73, the force F received by the attractive surface 80 from the contact surface 81 is increased. 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. For this reason, by providing the spring 73, the second rotating body 40 and the third rotating body 70 can be easily parallelized.

  [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. For this reason, it becomes easy to assemble the gear member 21 that houses the third rotating body 70 and the sprocket 22 that houses the second rotating body 40.

(Second 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 curved along the attractive surface 120. The second embodiment has the same effect as the first embodiment. Furthermore, since the attractive surface 120 is curved, the contact area with the contact surface 121 is increased. By increasing the contact area, the surface pressure due to the force acting on the attractive surface 120 and the contact surface 121 decreases, and the durability of the engaging 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 configuration of the third rotating body and the engaging member.
As shown in FIG. 7, the third rotating body 130 has an insertion hole 131 corresponding to the engagement hole 43. The engaging member 133 is inserted into the insertion hole 131.
The engaging member 133 has a round bar shape and is formed of a member separate from the third rotating body 130. In FIG. 7, in order to clarify the engaging member 133, the engaging member 133 is indicated by a dot pattern. The engaging member 133 is formed with an attractive surface 134 as in the first embodiment. In 3rd Embodiment, there exists an effect similar to 1st Embodiment.

(Other embodiments)
(I) At least one engagement member and engagement hole may be formed. Not only the number of the engaging members and the engaging holes, but the same effects as in the first embodiment can be obtained.

  (Ii) In another embodiment sharing the idea of the second embodiment, as shown in FIG. 8, the attractive surface 122 extends radially outward from the end surface 79 of the third rotating body 70 to the center of the engaging member 74. It is formed so that it may curve toward the radial inside. Further, the attractive force surface 122 is formed so as to curve from the radially outer side to the radially inner side 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 are obtained.

(Iii) In another embodiment sharing the idea of the third embodiment, as shown in FIG. 9, the idea of the first embodiment may be combined with the third embodiment. Both the round bar-shaped engaging member 133 and the engaging member 144 provided so as to protrude from the end surface 143 of the third rotating body 140 toward the second rotating body 40 may be formed.
As mentioned above, this invention is not limited to such embodiment, In the range which does not deviate from the meaning of invention, it can implement with a various form.

20 ... 1st rotating body,
40 ... the second rotating body,
43 ... engagement hole,
70 ・ ・ ・ Third rotating body,
74 ... engaging member,
80 ... attractive surface,
81 ... contact surface,
82 ・ ・ ・ Reference side surface,
83 ... Opposite side surface.

Claims (5)

A container-shaped first rotating body (20) that is rotatable;
A second rotating body (40) which is housed in the first rotating body and has at least one engagement hole (43) and is rotatable;
The first 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 coupled so as to be able to transmit rotation. A third rotating body (70) capable of changing a relative rotation phase between the first rotating body and the second rotating body by rotating eccentrically and accelerating / decelerating the rotation of the first rotating body or the second rotating body. )When,
At least one engaging member (74) for engaging the second rotating body and the third rotating body via the engaging hole;
With
One side of the side surface of the engagement member is a reference side surface (82),
When the surface facing the reference side surface is the facing side surface (83),
At least one of the engagement members has an attractive force surface (80) in which the reference side surface and the opposite side surface are inclined symmetrically with respect to the axial direction of the engagement member;
The second rotating body has a contact surface (81) that comes into contact with the attractive surface on the inner surface of the second rotating body,
The contact surface is formed along the attractive surface;
The eccentric oscillating speed reduction device in which a force acts in a direction in which the second rotating body and the third rotating body are attracted when the attractive surface comes into contact with the contact surface.   2. The eccentric oscillating speed reduction device according to claim 1, wherein the attraction surface is formed so that a diameter of the engagement member increases from the third rotating body toward the second rotating body. The attraction surface is formed so that at least a portion is curved;
The eccentric oscillating speed reduction device according to claim 1 or 2, wherein the contact surface is formed to be curved along the attractive surface.   The eccentric oscillating speed reduction device according to any one of claims 1 to 3, wherein a maximum diameter (D1) of the engagement member is smaller than a minimum diameter (D2) of the engagement hole. The eccentric oscillating speed reducer according to any one of claims 1 to 4,
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) that adjusts the valve timing of at least one of an intake valve (8) and an exhaust valve (9) that open and close the camshaft by transmission of rotation from the crankshaft.

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