JP6625294B2 - Actuator - Google Patents

Description

  The present invention relates to an actuator mounted on a vehicle.

  The exhaust passage valve according to Patent Literature 1 includes a main seal that prevents exhaust gas from leaking to the atmosphere side, and a dust seal that is provided closer to the atmosphere side than the main seal and protects the main seal from external dust. The main seal and the dust seal include a seal lip that elastically contacts the valve shaft.

Japanese Patent No. 5296012

  Since the conventional seal member is formed of a seal lip that is in line contact with the valve shaft, the seal lip is worn, and a gap is easily formed between the seal lip and the valve shaft, resulting in a problem that airtightness is reduced. When the airtightness is reduced, the liquid easily penetrates into the inside, so that rust is generated in the internal parts, which leads to a decrease in the function.

  The present invention has been made to solve the above-described problem, and has as its object to improve the robustness of airtightness.

The actuator according to the present invention is provided with a shaft, a motor for linearly moving the shaft, a first seal member installed on the outer peripheral surface of the shaft on a side closer to the motor, and installed on an outer peripheral surface of the shaft on a side farther from the motor. A second seal member, wherein the first seal member is in contact with an outer peripheral surface of the shaft to ensure airtightness, and is installed on an outer peripheral side of the first inner ring to hold the first inner ring. A second inner ring having a first outer ring, a second inner ring formed with a brush portion which is in contact with the outer peripheral surface of the shaft and removes and traps foreign matter adhering to the shaft, and an outer peripheral side of the second inner ring; installed in a second inner ring have a second outer ring that holds the to, from tension force of the first outer ring, those straining force of the second outer ring is large.

  According to the present invention, the first seal member is in contact with the outer peripheral surface of the shaft to ensure airtightness, and the first seal member is provided on the outer peripheral side of the first inner ring to hold the first inner ring. A second seal member having an outer ring, a second seal member provided with a brush portion formed in contact with an outer peripheral surface of the shaft to remove and trap foreign matter adhering to the shaft, and installed on an outer peripheral side of the second inner ring; Since the second outer ring is provided to hold the second inner ring, the robustness of airtightness can be improved.

FIG. 3 is a cross-sectional view illustrating a configuration example of the actuator according to the first embodiment. FIG. 3 is a cross-sectional view illustrating a seal structure in the actuator according to the first embodiment. FIG. 3 is a diagram illustrating a configuration example of a brush portion of a second seal member according to the first embodiment.

Hereinafter, in order to explain this invention in greater detail, the preferred embodiments of the present invention will be described with reference to the accompanying drawings.
Embodiment 1 FIG.
FIG. 1 is a cross-sectional view illustrating a configuration example of the actuator 1 according to the first embodiment. The actuator 1 will be described as an example in which the actuator 1 is used as a WG actuator that operates a wastegate (hereinafter, referred to as WG) valve of a turbocharged engine mounted on a vehicle.

  The actuator 1 mainly includes a motor 2 serving as a driving source, a shaft 3 for opening and closing a WG valve (not shown), and a seal structure 4 for the shaft 3. A not-shown WG valve is connected to the tip of the shaft 3, and the WG valve is activated by the linear movement of the shaft 3 in the axial direction.

  The motor 2 is a DC motor with a brush including a connector 5, a commutator 6, a brush 7, a rotor 8, a magnet 9, a yoke 10, a screw mechanism 11, and bearings 12 and 13, and is covered with a motor housing 14. Two bearings 12 and 13 are installed inside the motor housing 14 at both axial ends of the shaft 3. The bearings 12 and 13 rotatably support the rotor 8 including the coil and the commutator 6. The brush 7 is installed on the outer peripheral side of the commutator 6 in the motor housing 14. A magnet 9 and a yoke 10 are fixed to the motor housing 14 on the outer peripheral side of the rotor 8.

  The rotor 8 has a through hole through which the shaft 3 passes, and a female screw is formed on the inner peripheral surface of the through hole. On the other hand, on the outer peripheral surface of the shaft 3, there is formed a male screw that fits with the female screw by a screw action. The screw mechanism 11 is constituted by the female screw and the male screw. The screw mechanism 11 converts the rotational movement of the rotor 8 into a linear movement of the shaft 3.

When a voltage is applied to the connector 5, a current flows to the commutator 6 and the coil via the brush 7 electrically connected to the connector 5, and the rotor 8 including the coil rotates. Rotational movement of the rotor 8 is converted to linear movement by the screw mechanism 11, and the shaft 3 moves in the axial direction.
Note that the motor 2 is not limited to the brushed DC motor having the structure shown in FIG.

  Two parallel planes (hereinafter, referred to as two planes) and the like are formed on the shaft 3. The two planes and the like function as a rotation restricting portion 3a. Further, the tip of the shaft 3 penetrates the shaft housing 15. The shaft housing 15 accommodates a shaft guide 16 for guiding the linear movement of the shaft 3. On the inner peripheral surface of the through hole of the shaft guide 16, a guide portion 16 a such as a two-plane is formed in accordance with the shape of the rotation restricting portion 3 a of the shaft 3. When the shaft 3 linearly moves, the rotation restricting portion 3a and the guide portion 16a slide, whereby the rotational movement of the shaft 3 is regulated in accordance with the rotation of the rotor 8, and the guide is moved so that the shaft 3 linearly moves. Is done.

  A recess 16 b is formed on the inner peripheral surface of the through hole of the shaft guide 16. The first seal member 20 and the second seal member 30 are provided in the recess 16b. The first seal member 20 and the second seal member 30 constitute a seal structure 4. In addition, a cap 17 for preventing the first seal member 20 and the second seal member 30 from falling off is attached to the distal end of the shaft guide 16.

Next, details of the seal structure 4 will be described.
FIG. 2 is a sectional view showing the seal structure 4 in the actuator 1 according to the first embodiment. The seal structure 4 shown in FIG. 2 includes a first seal member 20, a second seal member 30, and a plate 40 interposed between the first seal member 20 and the second seal member 30. Note that the plate 40 can be omitted.

  The first seal member 20 is installed on the side near the motor 2 in the recess 16b. The first seal member 20 includes a first inner ring 21 installed on the outer peripheral surface of the shaft 3 and a first outer ring 22 installed on the outer peripheral side of the first inner ring 21. The first inner ring 21 is for ensuring airtightness, and prevents liquid from entering the inside of the motor 2 due to sliding of the shaft 3. Since the first inner ring 21 is a ring having a shape that comes into surface contact with the shaft 3, the first inner ring 21 is less likely to be worn than a seal lip that has a line contact shape, and the airtight robustness is improved. The first outer ring 22 holds the first inner ring 21 by its own tension.

  The second seal member 30 is installed on the WG valve side far from the motor 2 in the concave portion 16b. The second seal member 30 includes a second inner ring 31 installed on the outer peripheral surface of the shaft 3 and a second outer ring 32 installed on the outer peripheral side of the second inner ring 31. The second outer ring 32 holds the second inner ring 31 by its own tension. On the inner peripheral side of the second inner ring 31, a brush portion 33 for removing and capturing foreign matter attached to the shaft 3 is formed. FIG. 3 shows a configuration example of the brush unit 33. The brush portion 33 removes and traps foreign matter on the shaft 3 to prevent foreign matter from entering the inside of the motor 2 and also prevent damage and deformation of the first seal member 20 due to the foreign matter, thereby improving airtight robustness. Improve.

  The first inner ring 21 and the second inner ring 31 are made of, for example, a resin material having a low friction coefficient such as polytetrafluoroethylene (PTFE). The first outer ring 22 and the second outer ring 32 are made of, for example, an elastic body such as rubber. The plate 40 is made of, for example, a rigid body such as stainless steel.

  The tension of the first outer ring 22 and the tension of the second outer ring 32 may be the same or different. In the example of FIG. 2, the tension of the second outer ring 32 is greater than the tension of the first outer ring 22. By providing a difference in the tension, the functions of the first seal member 20 and the second seal member 30 are divided. That is, the first seal member 20 has a function of ensuring airtightness, and the second seal member 30 has a function of removing and capturing foreign matter.

  As described above, the actuator 1 according to the first embodiment includes the shaft 3, the motor 2 that linearly moves the shaft 3, and the first seal member 20 that is installed on the outer peripheral surface of the shaft 3 near the motor 2. And a second seal member 30 installed on the outer peripheral surface of the shaft 3 on the side far from the motor 2. The first seal member 20 is in contact with the outer peripheral surface of the shaft 3 to ensure airtightness, and the first outer ring is disposed on the outer peripheral side of the first inner ring 21 and holds the first inner ring 21. It has a ring 22. The second seal member 30 is provided on a second inner ring 31 provided with a brush portion 33 that is in contact with the outer peripheral surface of the shaft 3 and removes and traps foreign matter attached to the shaft 3, and is installed on the outer peripheral side of the second inner ring 31. It has a second outer ring 32 that holds the second inner ring 31. With this configuration, the airtight robustness of the first seal member 20 and the second seal member 30 is improved.

  In the actuator 1 according to the first embodiment, the tension force of the second outer ring 32 is larger than the tension force of the first outer ring 22. Thereby, the functions of the first seal member 20 and the second seal member 30 can be divided.

  In the present invention, within the scope of the invention, it is possible to modify any of the components of the embodiments or omit any of the components of the embodiments.

  The actuator according to the present invention is adapted to be used for a WG actuator or the like that operates a WG valve because the robustness of airtightness is improved.

  DESCRIPTION OF SYMBOLS 1 Actuator, 2 motors, 3 shafts, 3a rotation restricting section, 4 seal structure, 5 connector, 6 commutator, 7 brush, 8 rotor, 9 magnet, 10 yoke, 11 screw mechanism, 12, 13 bearing, 14 motor housing, 15 shaft housing, 16 shaft guide, 16a guide portion, 16b recess, 17 cap, 20 first seal member, 21 first inner ring, 22 first outer ring, 30 second seal member, 31 second inner ring, 32nd 2 outer rings, 33 brushes, 40 plates.

Claims (2)

Shaft and
A motor for linearly moving the shaft;
A first seal member installed on a side close to the motor on an outer peripheral surface of the shaft;
A second seal member installed on the outer peripheral surface of the shaft on a side far from the motor,
A first inner ring that is in contact with an outer peripheral surface of the shaft to ensure airtightness; and a first outer ring that is installed on an outer peripheral side of the first inner ring and holds the first inner ring. Has,
The second seal member is provided on a second inner ring formed with a brush portion that is in contact with an outer peripheral surface of the shaft and removes and traps foreign matter attached to the shaft, and is installed on an outer peripheral side of the second inner ring. have a second outer ring that holds the second inner ring,
An actuator , wherein the tension force of the second outer ring is greater than the tension force of the first outer ring .   The actuator according to claim 1, wherein a wastegate valve of the turbocharger is operated.

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