JP4620540B2 - Actuator - Google Patents

Description

  The present invention relates to an actuator having a detection mechanism for detecting a position when an output member is driven in one direction and the other direction.

In an actuator in which the output member is driven in both one direction and the other direction, a conventional detection mechanism for detecting the position when the output member is driven in one direction and the other direction is, for example, two magnets and a Hall IC. In such a detection mechanism, the position of the output member when the output member moves in one direction is detected by one of the two magnets, while the output member is detected by the other magnet. The position is detected when it moves in the other direction (see, for example, Patent Document 1).
JP 2000-258047 A

  However, the configuration disclosed in Patent Document 1 has a problem in that two magnets are required to detect the position of the output member in both directions, and the number of members is large. In addition, there is a problem that the detection mechanism cannot be arranged when a magnet cannot be arranged on the output member or its periphery due to layout restrictions.

  In view of the above problems, an object of the present invention is to provide an actuator that can perform bidirectional position detection of an output member with a small number of points of use even when there is a layout restriction around the output member or its periphery. It is in.

  In order to solve the above-described problems, in the present invention, a power source, a transmission mechanism that transmits driving force in one direction and the other direction from the driving source, and the driving force transmitted through the transmission mechanism are output. In an actuator having an output member that performs and a detection mechanism for performing position detection when the output member is driven in one direction and the other direction, the detection mechanism is interlocked with a transmission member included in the transmission mechanism. A cam; a detected member that is displaced in the same direction from a standby position by the cam when the transmission member moves in either one direction or the other direction; and a sensor that detects the displacement of the detected member. It is characterized by.

  In the present invention, when the driving force in one direction of the power source is transmitted via the transmission mechanism and the output member moves in one direction, the movement of the transmission member included in the transmission mechanism is transmitted to the detected member via the cam. Then, the member to be detected is displaced. Therefore, if the displacement of the detected member is detected by the sensor, the position when the output member moves in one direction can be detected. Further, when the driving force in the other direction of the power source is transmitted through the transmission mechanism and the output member moves in the other direction, the movement of the transmission member included in the transmission mechanism is transmitted to the detected member through the cam, The detected member is displaced. Therefore, if the displacement of the member to be detected is detected by the sensor, the position when the output member moves in the other direction can be detected. Accordingly, the position detection when the output member moves in one direction and the position when the output member moves in the other direction can be detected by the displacement of the common detected member. In addition, since the detected member is displaced in the same direction regardless of whether the output member moves in one direction or the output member moves in the other direction, position detection when the output member moves in one direction is detected. , And position detection when the output member moves in the other direction can be performed by a common sensor. Therefore, bidirectional position detection of the output member can be performed with a small number of parts. In addition, since it is not necessary to arrange the detection mechanism around the output member and its periphery, there is an advantage that the degree of freedom in design in terms of layout is high.

  In the present invention, it is preferable that the detected member is linearly displaced in the axial direction by the cam.

  In the present invention, the transmission mechanism is, for example, a gear transmission mechanism, and in this case, the transmission member is a single gear included in the gear transmission mechanism.

  In the present invention, the gear is preferably a final gear that transmits a driving force directly to the output member by the gear transmission mechanism.

  In the present invention, the cam is configured as a disc-shaped cam member that is separate from the gear, and the disc-shaped cam member is disposed so as to overlap the gear in a planar manner and has a common axis with the gear. A first interference portion that is disposed around the gear member and the disc-shaped cam member so as to displace the cam member when the gear moves in one direction, and the transmission member. And a second interference portion that displaces the cam member when moving in the other direction, and a play section is formed between the first interference portion and the second interference portion. Preferably it is.

  In the present invention, an arc-shaped groove extending around the axis is formed on one side member of the gear and the disc-shaped cam, and the groove is formed on the other side member when the gear rotates. A protrusion that moves along the groove is formed, and one end portion of the groove is the first interference portion, and the other end portion is the second interference portion. With this configuration, when the output member is driven in one direction, the gear rotates in an angle range exceeding 180 °, and when the output member is driven in the other direction, the gear exceeds 180 °. Even when rotating within the angular range, position detection can be performed with the detected member and the sensor in common.

  In the present invention, it is preferable that the cam is formed on the outer peripheral surface of the disc-shaped cam member, and the entire cam is located on the inner side of the outer peripheral edge of the gear.

  In the present invention, the position detection when the output member moves in one direction and the position when the output member moves in the other direction can be detected by the displacement of the common detected member. In addition, since the detected member is displaced in the same direction regardless of whether the output member moves in one direction or the output member moves in the other direction, position detection when the output member moves in one direction is detected. , And position detection when the output member moves in the other direction can be performed by a common sensor. Therefore, bidirectional position detection of the output member can be performed with a small number of parts. In addition, since it is not necessary to arrange the detection mechanism around the output member and its periphery, there is an advantage that the degree of freedom in design in terms of layout is high.

  Hereinafter, an example of an actuator to which the present invention is applied will be described with reference to the drawings.

(overall structure)
1A, 1B, and 1C are a side view, a longitudinal sectional view, and a transverse sectional view of an actuator to which the present invention is applied, respectively. The actuator 1 in this embodiment includes a DC motor (hereinafter simply referred to as a motor 3) that is a power source and a gear transmission that transmits a driving force of the motor 3 in a case 2 including a lower case 21 and an upper case 22. A mechanism 4 and an output member 5 that slides by the driving force of the motor 3 transmitted through the gear transmission mechanism 4 are provided. The output member 5 is a plate-like member, and a guide 23 using the inner wall of the case 2 is formed on the output member 5 as shown in FIG.

  The motor 3 can be rotated in both directions. By such bidirectional rotation, the output member 5 is protruded from the case 2 in one direction (indicated by an arrow A) and retracted into the case 2. It moves in the direction indicated by the arrow B and outputs the driving force of the motor 3. A worm gear 31 is fixed to the rotating shaft 30 of the motor 3, and the tip of the rotating shaft 30 is rotatably supported by a bearing 32.

  In this embodiment, the gear transmission mechanism 4 includes a first gear 41 that is an external gear that meshes with the worm gear 31 and a second gear 42 that is an external gear that meshes with the first gear 41. The second gear 42 meshes with a rack 51 formed on the output member 5 as a final gear.

(Configuration of detection mechanism)
FIG. 2 is an exploded perspective view showing a mechanical connection structure between a disc-like cam member used in the actuator detection mechanism to which the present invention is applied and a gear used in the transmission mechanism.

  The actuator 1 of the present embodiment includes a detection mechanism 6 for detecting the position of the output member 5, and the detection mechanism 6 includes a cam 7 that is interlocked with a second gear 42 included in the gear transmission mechanism 4, and The detected member 8 that is displaced in the same direction from the standby position by the cam 7 when the second gear 42 moves in one direction (counterclockwise CCW) and the other direction (clockwise CW), And a sensor 9 for detecting the displacement of the member 8 to be detected.

  In this embodiment, the sensor 9 is a photo interrupter. When the switch lever 80 fixed to the detected member 8 blocks the optical path of the photo interrupter, the detected member 8 is moved from the position shown in FIG. It detects that it is displaced in the direction shown. The sensor 9 is mounted on a flexible substrate 96 on which a chip resistor 95 or the like is mounted, and an external lead wire 97 is connected to the flexible substrate 96. Further, the flexible substrate 96 and the motor 3 are connected by a lead wire 98, and the motor 3 can be controlled based on the detection result by the sensor 9.

  Further, the detection mechanism 6 biases the detected member 8 toward the cam 7 and, as shown in FIG. 1C, a coil spring 61 as a biasing member that holds the detected member 8 in the standby position. The base end portion of the detected member 8 is always in contact with the cam 7.

  As shown in FIG. 1C and FIG. 2, the cam 7 is formed on the outer peripheral surface of a disc-shaped cam member 70 that is separate from the second gear 42, and has an arc portion 71 and a radius from the arc portion 71. And a convex portion 72 protruding outward in the direction. The disc-shaped cam member 70 is disposed so as to overlap the second gear 42 in a planar manner, and the cam 7 is entirely located inside the outer peripheral edge of the second gear 42. The disc-shaped cam member 70 and the second gear 42 are rotatably supported with respect to a common support shaft 43 (see FIGS. 1B and 1C). The second gear 42 is rotatable around a common axis.

  An arc-shaped groove 420 extending around the support shaft 43 is formed on the surface of the second gear 42 facing the disc-shaped cam member 70, while the second gear 42 is formed on the disc-shaped cam member 70. A protrusion 75 that fits inside the groove 420 is formed on the surface facing. Therefore, when the second gear 42 rotates counterclockwise CCW, one of the ends of the groove 420 located on the clockwise CW side contacts the projection 75 as the first interference portion 421. The disk-shaped cam member 70 is rotated counterclockwise CCW. Further, when the second gear 42 rotates clockwise CW (the other direction), the other end located on the counterclockwise CCW side comes into contact with the protrusion 75 as the second interference portion 422, and the disc The cam member 70 is rotated clockwise CW (the other direction). Here, since the protrusion 75 is sufficiently smaller than the length dimension of the groove 420, the protrusion 75 can move inside the groove 420. Therefore, the mechanical connection between the second gear 42 and the disc-shaped cam member 70 is released while the projection 75 is in the middle of the groove 420 in the length direction. In this way, a play section is secured between the first interference part 421 and the second interference part 422 of the groove 420.

(Operation of detection mechanism)
FIGS. 3A to 3F and FIGS. 3G to 3L are explanatory views when the output member is driven in one direction in the actuator to which the present invention is applied, and the output member is driven in one direction. It is explanatory drawing at the time. 3 (A) and 3 (G) are explanatory views showing the relationship between the position of the output member and the sensor output in the actuator to which the present invention is applied, and FIGS. 3 (B) to (F), and (H)-(L) are each a top view which shows the positional relationship of the 2nd gearwheel, disk-shaped cam member, and to-be-detected member at the time of driving an output member in the actuator to which this invention is applied. In this embodiment, the stroke in the one direction and the other direction of the output member 5 is 60 mm. Hereinafter, the operation when the output member 5 is driven in one direction and then driven in the other direction will be described.

  First, when the output member 5 has finished moving in the direction indicated by the arrow B, the positional relationship between the second gear 42 and the disc-shaped cam member 70 and the base end portion of the detected member 8 and the cam 7 is in the state shown in FIG. 3B, the projection 75 is in contact with the second interference portion 422 of the groove 420, and the base end portion of the detected member 8 is the convex portion 72 of the cam 7. And is in a position in contact with the arc 71. For this reason, the detected member 8 is biased toward the side surface portion of the disc-like cam member 70 by the coil spring 61 and is in the standby position, so that the output from the sensor 9 is as shown in FIG. At the OFF level.

  From this state, when the rotating shaft 30 of the motor 3 rotates to move the output member 5 in the direction indicated by the arrow A, the rotation is transmitted to the output member 5 via the worm gear 31 and the gear transmission mechanism 4. At that time, in the gear transmission mechanism 4, the first gear 41 rotates clockwise CW, the second gear 42 rotates counterclockwise CCW, and the output member 5 moves in the direction indicated by the arrow A. As a result, in the detection mechanism 6, the positional relationship between the second gear 42 and the disc-shaped cam member 70 shifts to the state shown in FIGS. 3 (C) and 3 (D). Since such a section is an idle section, the protrusion 75 only moves relative to the groove 420, and the disc-shaped cam member 70 does not rotate. For this reason, since the member 8 to be detected is not displaced, as shown in FIG. 3A, the output from the sensor 9 remains at the OFF level, and the motor 3 continues to rotate.

  When the output member 5 is further driven in the direction indicated by the arrow A, the detection mechanism 6 causes the positional relationship between the second gear 42 and the disc-shaped cam member 70 and the second gear 42 and the disc-shaped cam member. The positional relationship with 70 shifts to the state shown in FIG. 3F through the state shown in FIG. When such an operation is performed, the second gear 42 rotates a little less than one turn counterclockwise CCW from the state shown in FIG. 3B to the state shown in FIG. 3F.

  During this time, the first interference portion 421 of the groove 420 abuts against the protrusion 75 and presses the protrusion 75 counterclockwise CCW, so that the disc-shaped cam member 70 is interlocked with the second gear 42 and counterclockwise. Rotate around CCW. For this reason, the detected member 8 is pressed by the convex portion 72 of the cam 7 and displaced in the direction indicated by the arrow C, so that the output from the sensor 9 becomes ON level as shown in FIG.

  Then, when the output member 5 reaches the end in the direction indicated by the arrow A, as shown in FIG. 3 (F), the convex portion 72 of the cam 7 passes through a position where it abuts on the detected member 8, so that the detected member 8 is again biased toward the side surface of the cam member 70 by the coil spring 61 and returns to the standby position. Accordingly, as shown in FIG. 3A, the output from the sensor 9 is at the OFF level. Therefore, in the output signal from the sensor 9, it is possible to detect that the output member 5 has moved to the end in the direction indicated by the arrow A simply by detecting the trailing edge PA of the pulse. Based on the detection result, the motor 3 Can be stopped.

  Next, with reference to FIGS. 3G to 3L, the operation when the output member 5 is slid in the direction of arrow B in FIG. 1 in the actuator 1 of the present embodiment will be described.

  First, when the output member 5 has finished moving in the direction indicated by the arrow A, the positional relationship between the second gear 42 and the disc-shaped cam member 70 and the base end portion of the detected member 8 and the cam 7 is in the state shown in FIGS. 3 (F) and 3 (H), the protrusion 75 is in contact with the first interference portion 421 of the groove 420, and the base end portion of the detected member 8 is the cam 7 It is in a position that is displaced from the convex portion 72 and is in contact with the arc portion 71. For this reason, the detected member 8 is biased toward the side surface portion of the disc-shaped cam member 70 by the coil spring 61 and is in the standby position, so that the output from the sensor 9 is as shown in FIG. At the OFF level.

  From this state, when the rotating shaft 30 of the motor 3 rotates to move the output member 5 in the direction indicated by the arrow B, the rotation is transmitted to the output member 5 via the worm gear 31 and the gear transmission mechanism 4. At that time, in the gear transmission mechanism 4, the first gear 41 rotates counterclockwise CCW, the second gear 42 rotates clockwise CW, and the output member 5 moves in the direction indicated by the arrow B. As a result, in the detection mechanism 6, the positional relationship between the second gear 42 and the disc-shaped cam member 70 shifts to the state shown in FIGS. 3 (I) and 3 (J). Since such a section is an idle section, the protrusion 75 only moves relative to the groove 420, and the disc-shaped cam member 70 does not rotate. For this reason, since the member 8 to be detected is not displaced, as shown in FIG. 3G, the output from the sensor 9 remains at the OFF level, and the motor 3 continues to rotate.

  When the output member 5 is further driven in the direction indicated by the arrow B, the detection mechanism 6 causes the positional relationship between the second gear 42 and the disc-shaped cam member 70 and the second gear 42 and the disc-shaped cam member. The positional relationship with 70 shifts to the state shown in FIG. 3L through the state shown in FIG. When such an operation is performed, the second gear 42 rotates slightly less than one turn clockwise CW from the state illustrated in FIG. 3H to the state illustrated in FIG.

  In the meantime, the second interference portion 422 of the groove 420 abuts against the protrusion 75 and presses the protrusion 75 clockwise CW, so that the disc-like cam member 70 is interlocked with the second gear 42 and rotated clockwise CW. Rotate to. For this reason, the member 8 to be detected is pressed by the convex portion 72 of the cam 7 and displaced in the direction indicated by the arrow D, so that the output from the sensor 9 becomes ON level as shown in FIG.

  When the output member 5 reaches the end in the direction indicated by the arrow B, as shown in FIG. 3 (L), the convex portion 72 of the cam 7 passes through the position where it abuts on the member 8 to be detected. 8 is again biased toward the side surface of the cam member 70 by the coil spring 61 and returns to the standby position. Therefore, as shown in FIG. 3G, the output from the sensor 9 is at the OFF level. Therefore, in the output signal from the sensor 9, it is possible to detect that the output member 5 has moved to the end in the direction indicated by the arrow B only by detecting the falling edge PB of the pulse. Based on the detection result, the motor 3 Can be stopped.

(Main effects of this form)
As described above, in the actuator 1 of this embodiment, the position of the output member 5 when the output member 5 is moved in the direction indicated by the arrow A and the position when the output member 5 is moved in the direction of the arrow B are set as the common detected member 8. It can be detected by displacement. In addition, the detected member 8 is displaced in the direction indicated by the arrow C both when the output member 5 moves in the direction indicated by the arrow A and when the output member 5 moves in the direction indicated by the arrow B. The common sensor 9 can perform position detection when the output member 5 moves in the direction indicated by arrow A and position detection when the output member 5 moves in one direction. Therefore, bidirectional position detection of the output member 5 can be performed with a small number of parts. Further, since the detection mechanism 6 does not have to be arranged around the output member 5 and its periphery, there is an advantage that the degree of freedom in design in terms of layout is high.

  Furthermore, since a play section is secured between the first interference portion 421 and the second interference portion 422 that transmit the rotation of the second gear 42 to the disc-shaped cam member 70, the output member 5 is When driving in the direction indicated by the arrow A, the second gear 42 rotates in an angle range exceeding 180 °, and when the output member 5 is driven in the direction indicated by the arrow B, the second gear 42 is Even when rotating in an angle range exceeding 180 °, position detection can be performed with the detected member 8 and the sensor 9 in common.

(Other embodiments)
In the above embodiment, when the play section is provided between the first interference portion 421 and the second interference portion 422 that transmits the rotation of the second gear 42 to the disc-shaped cam member 70, Although the groove 420 of the gear 42 and the protrusion 75 of the disc-like cam member 70 are used, the protrusion may be provided on the second gear 42 and the groove may be provided on the disc-like cam member 70. Further, a configuration in which protrusions are provided on both the second gear 42 and the disc-shaped cam member 70 may be employed.

  In the above embodiment, an optical switch such as a photo interrupter is used as the sensor 9. However, a magnetic switch such as a magnet and a Hall IC, or a mechanical switch such as a tact switch may be used. In the above embodiment, the output member that performs a sliding operation is used. However, an output member that performs a rotating operation may be used. Furthermore, in the above embodiment,

(A), (B), (C) are respectively a side view, a longitudinal sectional view, and a transverse sectional view of an actuator to which the present invention is applied. It is a disassembled perspective view which shows the mechanical connection structure of the disc-shaped cam member used for the detection mechanism of the actuator to which this invention is applied, and the gearwheel used for the transmission mechanism. (A)-(F) and (G)-(L) are explanatory drawings when the output member is driven in one direction in the actuator to which the present invention is applied, and when the output member is driven in one direction, respectively. It is explanatory drawing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Actuator 3 Motor 4 Transmission mechanism 5 Output member 6 Detection mechanism 7 Cam 8 Detected member 9 Sensor 41 First gear 42 Second gear 61 Coil spring (biasing member)
70 cam member 71 arc portion 72 convex portion 75 protrusion 420 groove 421 first interference portion 422 second interference portion

Claims (7)

A power source, a transmission mechanism for transmitting driving force in one direction and the other direction from the driving source, an output member for outputting the driving force transmitted through the transmission mechanism, and the output member in one direction and In an actuator having a detection mechanism for performing position detection when driven in the other direction,
The detection mechanism includes a cam interlocked with a transmission member included in the transmission mechanism, and a detected object that is displaced in the same direction from the standby position by the cam when the transmission member moves in either one direction or the other direction. An actuator comprising: a member; and a sensor that detects a displacement of the detected member.   2. The actuator according to claim 1, wherein the member to be detected is linearly displaced in the axial direction by the cam. In Claim 1 or 2, the transmission mechanism is a gear transmission mechanism,
The actuator, wherein the transmission member is one gear included in the gear transmission mechanism.   4. The actuator according to claim 3, wherein the gear is a final gear that transmits a driving force directly to the output member by the gear transmission mechanism. 5. The cam according to claim 3, wherein the cam is a disc-shaped cam member that is separate from the gear.
The disk-shaped cam member is disposed so as to overlap with the gear in a planar manner, and is disposed so as to be rotatable around an axis common to the gear.
One of the gear and the disc-shaped cam member includes a first interference portion that displaces the cam member when the gear moves in one direction, and a state in which the transmission member moves in the other direction. A second interference part for displacing the cam member, and
An actuator, wherein a play section is formed between the first interference part and the second interference part. In Claim 5, the one side member of the gear and the disc-shaped cam is formed with an arc-shaped groove extending around the axis, and the other side member is formed when the gear rotates. A protrusion is formed that moves along the groove in the groove,
One end of the both ends of the groove is the first interference part, and the other end is the second interference part.   7. The actuator according to claim 5, wherein the cam is formed on an outer peripheral surface of the disc-shaped cam member, and the entire cam is located inside an outer peripheral edge of the gear.

Images