JP7194607B2 - rotary drive mechanism - Google Patents

Description

The present invention relates to a rotation drive mechanism that applies a rotational force to a rotatably supported rotating body to rotate it in one direction using an elastic member.

Conventionally, a throttle gear as a driven gear, a small-diameter gear that meshes with the throttle gear, a stopper that prevents rotation of the throttle gear in one direction beyond a predetermined angle, and an urging force applied to the throttle gear in that one direction. There is known a rotary drive mechanism including a return spring that provides a force (see, for example, Patent Literature 1).

The rotary drive mechanism of Patent Document 1 is used in a throttle body having a throttle valve for controlling the intake air amount of an internal combustion engine to open and close the throttle valve via a throttle gear provided on the same rotating shaft. be done.

The return spring is composed of a plate spring, one end of which is fixed to the throttle body as a fixed end and the other end of which is a free end, contacts the throttle gear, and applies the above-described biasing force to the throttle gear. The default stopper defines the default opening of the throttle valve.

Japanese Unexamined Patent Application Publication No. 2011-1861

However, according to the rotary drive mechanism of Patent Document 1, when opening and closing the throttle valve, a relatively large stress is applied locally to the leaf spring as the return spring, such as at its bent portion and fixed end. For this reason, it is necessary to use a leaf spring with a relatively wide width as the return spring, which increases the size of the rotation drive mechanism in the direction of the rotation axis.

SUMMARY OF THE INVENTION An object of the present invention is to provide a rotation drive mechanism having a small size in the direction of the rotation axis.

The rotary drive mechanism of the present invention is
a first rotating body having a driven gear rotatable about a first axis of rotation;
a second rotating body rotatable about a second rotation axis substantially parallel to the first rotation axis and having a small-diameter gear that meshes with the driven gear;
a body that supports the first rotating body and the second rotating body so as to be rotatable about the first rotation axis and the second rotation axis, respectively;
It has a first engaging portion attached to the body at one end and a second engaging portion attached to the first rotating body at the other end, and rotates in one direction with respect to the first rotating body. In a rotational drive mechanism comprising an elastic member that applies force,
The first locking portion is perpendicular to a first reference plane including the first rotation axis and the second rotation axis and separated by a second reference plane including the second rotation axis. attached to the body in the opposite space,
The elastic member extends to a space opposite to the second rotation axis separated by a third reference plane orthogonal to the first reference plane and including the first rotation axis. .

In this configuration, when the small-diameter gear is driven, its driving force is transmitted to the driven gear, so the first rotating body rotates against the rotational force of the elastic member. During this time, the elastic member gradually deforms while exerting an urging force in a direction opposite to the direction of rotation on the first rotor.

Since this deformation is performed over a long section exceeding the distance between the second reference plane and the third reference plane, excessive bending does not occur in the elastic member. That is, each part of the elastic member is elastically deformed in a shared manner, so that a relatively constant biasing force is applied to the first rotating body over the angular range in which it rotates.

That is, the elastic member does not bend excessively due to concentrated deformation for applying the rotational force to a short section. Therefore, a desired rotational force can be applied to the first rotor without increasing the width of the elastic member.

In the present invention, the second rotating body includes a large-diameter gear that has a larger diameter than the small-diameter gear and rotates around the second rotation axis integrally with the small-diameter gear,
The elastic member is a strip-shaped member having a width in a direction along the first rotation axis,
At least a portion of the large-diameter gear and the elastic member may overlap when viewed in a direction orthogonal to the first reference plane.

According to this, since the large-diameter gear and the elastic member overlap in the direction orthogonal to the first reference plane, for example, the elastic member is arranged in a space including the width of the large-diameter gear while allowing the overlap. It is also possible to This makes it possible to reduce the dimension of the rotation drive mechanism in the direction along the first rotation axis.

In this case, the elastic member contacts the first reference plane from the opposite side, the body is arranged closer to the first reference plane than the elastic member, and has a width extending in a direction orthogonal to the first reference plane. comprising an abutment block having
At least a portion of the contact block is located closer to the first engaging portion than the first reference plane, out of two planes parallel to the first reference plane and passing through the addendum circle of the large-diameter gear. It may be located on the side of the first reference plane rather than the fourth reference plane, which is the surface on which the first reference plane is located.

In this configuration, when the elastic member is displaced from the contact block in the direction toward the first reference plane, the contact block receives force in that direction from the elastic member. For this reason, the contact block needs to have a thickness in the direction perpendicular to the first reference plane that is sufficient to ensure strength to withstand the force received.

In this regard, in the above configuration, the range where the contact block exists extends to the area on the first reference plane side of the fourth reference plane passing through the addendum circle of the large-diameter gear. This allows the abutment block to meet the required strength while minimizing the increase in dimension in the direction orthogonal to the first reference plane of the rotary drive mechanism.

Further, in this case, the driven gear is provided on the large-diameter gear side of the driven gear in the direction along the first rotation axis, and is a rotation locking portion for attaching the second locking portion. with
The rotation locking portion and the second locking portion may be arranged at positions that do not interfere with the large-diameter gear within the range in which the first rotating body rotates.

According to this, not only the first engaging portion but also the second engaging portion can be arranged in a space including the gear width of the large-diameter gear. The dimensions can be reliably reduced.

The fluid control valve of the present invention is
a flow path having a substantially cylindrical inner wall surface; a valve body that rotates in the flow path to change the opening area of the flow path; A fluid control valve comprising: a valve stem supported for rotation within the passage;
a first rotating body of the rotation drive mechanism is coupled to the valve shaft so as to rotate integrally with the valve shaft;
the body of the rotary drive mechanism includes a shaft support for supporting the valve shaft,
The shaft support portion extends outward from the inner wall surface of the flow path in a direction along the first rotation axis of the first rotor,
The rotation drive mechanism is provided on the side of the first rotor on which the flow path is arranged relative to the driven gear of the first rotor when viewed in a direction along the first rotation axis. with a rotation lock,
The second locking portion of the rotation drive mechanism is composed of a strip-shaped member having a width in the direction along the first rotation axis,
At least part of the second locking portion is arranged within a range in which the shaft support portion extends in the direction along the first rotation axis.

According to the present invention, since the second locking portion can be arranged in the space including the shaft support portion, the dimension of the rotary drive mechanism in the direction along the first rotation axis can be reduced.

1 is a front view showing a main part of a fluid control valve having a rotary drive mechanism according to a first embodiment of the invention; FIG. FIG. 2 is a sectional view taken along line II-II of FIG. 1; FIG. 7 is a cross-sectional view showing the essential parts of a fluid control valve having a rotation drive mechanism according to a second embodiment of the invention; 4A is a diagram showing a state in which the first rotating body has rotated about 45° from the state in FIG. 1, and FIG. 4B is a diagram illustrating a state in which the first rotating body has rotated about 90° from the state in FIG. be.

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 show the essential parts of a fluid control valve having a rotary drive mechanism according to a first embodiment of the present invention. This fluid control valve 1 is used to control the intake air amount of the internal combustion engine. 1 and 2 show the fluid control valve 1 with the cover removed.

As shown in FIGS. 1 and 2, the fluid control valve 1 has a substantially cylindrical inner wall surface, a flow path 2 through which intake air to the internal combustion engine passes, and a flow path 2 through which air is rotated in the flow path 2. a valve body 3 that changes the opening area of the valve body 3; a valve shaft 4 that supports the valve body 3 so as to be rotatable within the flow path 2; and a rotation drive mechanism 5 that rotates the valve shaft 4.

The rotary drive mechanism 5 includes a first rotating body 8 having a driven gear 7 rotatable around a first rotation axis 6 and a second rotating body 10 having a small diameter gear 9 meshing with the driven gear 7 . The second rotor 10 is rotatable about a second rotation axis 11 substantially parallel to the first rotation axis 6 . The first rotating body 8 is connected to the valve shaft 4 so as to rotate together with the valve shaft 4 .

A first rotating body 8 and a second rotating body 10 are rotatably supported by a body 12 about a first rotating axis 6 and a second rotating axis 11, respectively. The body 12 is provided with a rotation limiter 13 that limits one of the rotatable ranges of the first rotor 8 .

The rotation drive mechanism 5 also includes an elastic member 14 that imparts a rotational force to the first rotating body 8 in a direction toward the rotation restricting portion 13, that is, in one direction. The elastic member 14 has a first locking portion 15 attached to the body 12 at one end and a second locking portion 16 attached to the first rotating body 8 at the other end. 2, the position of the portion of the elastic member 14 below the first reference plane 17 including the first rotation axis 6 and the second rotation axis 11 is indicated by a chain double-dashed line.

The first locking portion 15 is attached to the body 12 in a space 19 opposite the first rotation axis 6 separated by a second reference plane 18 orthogonal to the first reference plane 17 and including the second rotation axis 11 . It is attached. The elastic member 14 extends to a space 21 opposite the second rotation axis 11 , separated by a third reference plane 20 orthogonal to the first reference plane 17 and containing the first rotation axis 6 .

When no external force is applied to the elastic member 14, the elastic member 14 extends in a straight line rather than in the state shown in FIG. Therefore, when the elastic member 14 is placed in the body 12 with the first engaging portion 15 and the second engaging portion 16 attached as shown in FIG. A rotational force in the direction of the arrow Y is applied to the first rotating body 8 .

The second rotating body 10 includes a large-diameter gear 22 that has a larger diameter than the small-diameter gear 9 and rotates around the second rotation axis 11 integrally with the small-diameter gear 9 . As the small-diameter gear 9 and the large-diameter gear 22, resin-molded gears may be used.
A pinion gear 24 provided on the rotating shaft of a motor 23 is meshed with the large-diameter gear 22 so that the rotational force of the motor 23 is transmitted to the large-diameter gear 22 .

The elastic member 14 is configured using a strip-shaped member, such as a leaf spring, having a width in the direction along the first rotation axis 6 . When viewed in a direction orthogonal to the first reference plane 17, the large-diameter gear 22 and the elastic member 14 at least partially overlap each other, as shown in FIG. The second locking portion 16 of the elastic member 14 is composed of a strip-shaped member having a width in the direction along the first rotation axis 6 .

The second locking portion 16 is formed, for example, by rounding the end portion of the elastic member 14 into a tubular shape extending in the direction along the first rotation axis 6 . In this case, the second locking portion 16 is fitted to a rotation locking portion 25 projecting in the direction opposite to the flow path 2 along the direction along the first rotation axis 6 from the vicinity of the center of the first rotating body 8. It can be attached to the first rotating body 8 by making

The body 12 includes an abutment block 26 arranged closer to the first reference plane 17 than the elastic member 14 and having a width in a direction orthogonal to the first reference plane 17 . The contact block 26 is configured so that the contact block 26 receives the force that the elastic member 14 receives in the direction of the large-diameter gear 22 when the elastic member 14 contacts the contact block 26 from the side opposite to the first reference plane 17 . It has become.

At least a portion of the contact block 26 is located closer to the first engaging portion 15 than the first reference plane 17, which is one of the two planes parallel to the first reference plane 17 and passing through the addendum circle of the large-diameter gear 22. It is positioned closer to the first reference plane 17 than the fourth reference plane 27, which is the plane on which the first reference plane 17 is located.

In addition, the body 12 includes a shaft support portion 28 that supports the valve shaft 4 , and the shaft support portion 28 extends outward from the inner wall surface of the flow path 2 in a direction along the first rotation axis 6 of the first rotor 8 . extend to

In this configuration, when the motor 23 is not driven, the first rotor 8 is biased in the direction of the arrow Y by the rotational force applied by the elastic member 14 and contacts the rotation limiter 13 . , the valve body 3 is in a state of closing the flow path 2 .

In this state, when the motor 23 is driven to rotate against the biasing force of the elastic member 14 , the rotational force is transmitted through the pinion gear 24 , the large-diameter gear 22 and the small-diameter gear 9 to the driven gear 7 . is transmitted to As a result, the first rotating body 8 is rotated in the direction opposite to the arrow Y, and the valve body 3 is opened to a degree corresponding to the amount of driving of the motor 23 .

FIG. 4A shows a state in which the first rotating body 8 has rotated about 45° from the state in which it abuts against the rotation restricting portion 13, and FIG. state. A portion of the elastic member 14 closer to the second stopping portion 16 than the portion of the elastic member 14 that abuts against the contact block 26 and that is disposed so as to surround the rotation axis of the first rotor 8 is the first rotor 8. With the rotation of , the first rotating body 8 is deformed so as to be wound around the rotating shaft of the first rotating body 8, and the force that urges the first rotating body 8 in the arrow Y direction increases.

Further, when the motor 23 is rotated in the opposite direction, the elastic member 14 also urges the first rotating body 8 to rotate in the arrow Y direction, and the opening degree of the valve body 3 becomes smaller.

Therefore, by controlling the drive of the motor 23, the opening degree of the valve body 3 can be adjusted and the flow rate of the fluid flowing through the flow path 2 can be controlled. During this time, the elastic member 14 deforms according to the opening degree of the valve body 3 , but the first locking portion 15 side of the elastic member 14 is locked to the body 12 and the elastic member 14 is closed. 14 is in contact with the contact block 26, the displacement is suppressed.

As shown in FIGS. 1, 4A, and 4B, as the elastic member 14 deforms, the location where the elastic member 14 contacts the contact block 26 changes in the direction along the first reference plane 17. However, the portion of the abutment block 26 that abuts against the elastic member 14 is formed in a gently curved state that protrudes toward the elastic member 14 side, and the elastic member 14 is formed on the abutment block 26 . Consideration is given so that a large local stress is not applied to the elastic member 14 no matter where it abuts.

In addition, although the curvature of the elastic member 14 on the side of the second engaging portion 16 slightly changes over its entirety according to the opening degree of the valve body 3, the local change is small. Therefore, the local stress generated in the elastic member 14 according to the opening and closing drive of the valve body 3 does not become so large.

As described above, according to the present embodiment, the elastic member 14 extends beyond the distance between the second reference plane 18 and the third reference plane 20 . Therefore, the elastic member 14 can be easily arranged in the rotary drive mechanism 5 without excessive bending. Therefore, as the elastic member 14, it is possible to use a leaf spring that has a small width in the direction along the first rotation axis 6 but a large plate thickness and that can obtain a high repulsive force even with a slight deformation.

In addition, since the large-diameter gear 22 and the elastic member 14 overlap in the direction perpendicular to the first reference plane 17, for example, the overlap of the elastic member 14 in the space including the width of the large-diameter gear 22 is allowed. It is also possible to arrange them one by one. As a result, the dimension of the rotation drive mechanism 5 in the direction along the first rotation axis 6 can be reduced.

Further, the range in which the contact block 26 exists extends to the area closer to the first reference plane 17 than the fourth reference plane 27 so as not to interfere with the large-diameter gear 22 . Thereby, the abutment block 26 can satisfy the required strength and at the same time can minimize an increase in the dimension of the rotary drive mechanism 5 in the direction orthogonal to the first reference plane 17 .

In addition, in this embodiment, since metal gears are used as the small-diameter gear 9 and the large-diameter gear 22 that constitute the second rotating body 10, the second rotation axis can Sufficient strength can be obtained even if the width of the second rotor 10 in the direction along 11 is reduced. Therefore, the dimension in the direction along the second rotation axis 11 can be reduced.

FIG. 3 shows a fluid control valve 1b according to a second embodiment of the invention. As shown in FIG. 3, in the fluid control valve 1b, the rotation locking portion 25 is located closer to the large-diameter gear 22 than the driven gear 7 in the direction along the first rotation axis 6 of the first rotor 8b. That is, it is provided on the side where the flow path 2 is arranged with respect to the driven gear 7 . The rotation locking portion 25 and the second locking portion 16 are arranged at positions where they do not interfere with the large-diameter gear 22 within the range in which the first rotating body 8 rotates.

Such a position that does not interfere with the large-diameter gear 22 is, for example, when the rotation angle range in which the first rotating body 8 rotates is 240° or less, the diameter of the large-diameter gear 22 is as shown in FIG. Even if it is large, it can be secured easily.

In this case, at least part of the second locking portion 16 may be arranged within a range in which the shaft support portion 28 extends in the direction along the first rotation axis 6 . In this case, the elastic member 14b has a shape extending substantially linearly when viewed in the direction perpendicular to the first reference plane 17, unlike in the case of the first embodiment (see FIG. 2). Other points are the same as in the case of the first embodiment.

According to the present embodiment, not only the first locking portion 15 but also the second locking portion 16 can be arranged in the space including the gear width of the large-diameter gear 22 . The dimension in the direction along the axis 6 can be reliably reduced.
Moreover, when at least part of the second locking portion 16 is arranged within the range in which the shaft support portion 28 extends, the size of the rotation drive mechanism 5 can be further reduced.

It should be noted that the present invention is not limited to the above-described embodiments, and can be implemented with appropriate modifications. For example, the elastic member 14 may be composed of a linear member having a circular cross section, instead of using a leaf spring. Also, the rotary drive mechanism may be applied to other applications other than the fluid control valve.

DESCRIPTION OF SYMBOLS 1, 1b... Fluid control valve, 2... Flow path, 3... Valve body, 4... Valve shaft, 5... Rotary drive mechanism, 6... First rotation axis, 7... Driven gear, 8, 8b... First rotating body , 9 small-diameter gear 10 second rotating body 11 second rotation axis 12 body 13 rotation limiting portion 14, 14b elastic member 15 first locking portion 16 second locking portion stop portion 17 first reference plane 18 second reference plane 19 space 20 third reference plane 21 space 22 large gear 23 motor 24 pinion gear 25 rotation Locking portion 26 Contact block 27 Fourth reference plane 28 Shaft support Y Arrow.

Claims (5)

a first rotating body having a driven gear rotatable about a first axis of rotation;
a second rotating body rotatable about a second rotation axis substantially parallel to the first rotation axis and having a small-diameter gear that meshes with the driven gear;
a body that supports the first rotating body and the second rotating body so as to be rotatable about the first rotation axis and the second rotation axis, respectively;
It has a first engaging portion attached to the body at one end and a second engaging portion attached to the first rotating body at the other end, and rotates in one direction with respect to the first rotating body. In a rotational drive mechanism comprising an elastic member that applies force,
The first locking portion is perpendicular to a first reference plane including the first rotation axis and the second rotation axis and separated by a second reference plane including the second rotation axis. attached to the body in the opposite space,
The elastic member extends to a space opposite to the second rotation axis separated by a third reference plane orthogonal to the first reference plane and including the first rotation axis. rotary drive mechanism. The second rotating body includes a large-diameter gear that has a larger diameter than the small-diameter gear and rotates around the second rotation axis integrally with the small-diameter gear,
The elastic member is a strip-shaped member having a width in a direction along the first rotation axis,
2. The rotary drive mechanism according to claim 1, wherein the large-diameter gear and the elastic member overlap at least partially when viewed in a direction perpendicular to the first reference plane. The body abuts against the first reference plane from the side opposite to the elastic member, is arranged closer to the first reference plane than the elastic member, and has a width in a direction orthogonal to the first reference plane. with blocks,
At least a portion of the contact block is located closer to the first engaging portion than the first reference plane, out of two planes parallel to the first reference plane and passing through the addendum circle of the large-diameter gear. 3. The rotary drive mechanism according to claim 2, wherein the rotation drive mechanism is located closer to the first reference plane than the fourth reference plane, which is the surface to which the first reference plane is directed. the driven gear includes a rotation locking portion for mounting the second locking portion, which is provided closer to the large-diameter gear than the driven gear in the direction along the first rotation axis;
4. The rotation according to claim 2 or 3, wherein the rotation locking portion and the second locking portion are arranged at positions that do not interfere with the large-diameter gear within a range in which the first rotating body rotates. drive mechanism. A rotary drive mechanism according to any one of claims 1 to 4, a flow path having a substantially cylindrical inner wall surface, a valve body that rotates in the flow path to change the opening area of the flow path, and the valve a valve stem supporting a body for rotation within the flow path, the fluid control valve comprising:
a first rotating body of the rotation drive mechanism is coupled to the valve shaft so as to rotate integrally with the valve shaft;
the body of the rotary drive mechanism includes a shaft support for supporting the valve shaft,
The shaft support portion extends outward from the inner wall surface of the flow path in a direction along the first rotation axis of the first rotor,
The rotation drive mechanism is provided on the side of the first rotor on which the flow path is arranged relative to the driven gear of the first rotor when viewed in a direction along the first rotation axis. with a rotation lock,
The second locking portion of the rotation drive mechanism is composed of a strip-shaped member having a width in the direction along the first rotation axis,
A fluid control valve, wherein at least part of the second locking portion is arranged within a range in which the shaft support portion extends in a direction along the first rotation axis.

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