JP2004067276A - Rotary mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotary mechanism capable of controlling the rotation of a rotary section highly accurately irrespective of its simple constitution. <P>SOLUTION: While a rotary section 12 starts its rotation from its center position, and the magnetic sensor 19 attached to the rotary section 12 detects the N pole of the center position magnetic tape 24 adhered to a base table 10, the rotation of the rotary section 12 is accelerated. While the N pole of the center position magnetic tape 24 is not detected by the magnetic sensor 19, the rotary section 12 is rotated at a uniform speed. When the magnetic sensor 19 detects the S pole of the rotary position magnetic tape 25 adhered to the base table 10, the rotation speed of the rotary section 12 is reduced. When the optical sensor 23 installed at a position P1 detects the dog 20 of the rotary section 12, the rotary section 12 stops. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a turning mechanism, and more particularly, to a turning mechanism that rotates a turning portion by a predetermined angle from a center position to a turning position with respect to a base, such as a turning table on a tracked truck.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, in an automatic warehouse or the like, a truck that travels on a track to transport a load has been used. The load is placed on a swivel table provided on the trolley, and is transferred from the trolley to a rack or the like on the track side while being rotated by, for example, 90 degrees by the swivel table.
Here, FIG. 3 shows a swivel table used for such a bogie. A driving wheel 2 is arranged in contact with an inner peripheral surface of the turning portion 1, and the turning portion 1 turns by rotating the driving wheel 2 by a motor 3. At this time, the turning angle of the turning portion 1 is detected by the encoder 4 in contact with the outer peripheral portion of the turning portion 1 to control the acceleration / deceleration and stop of the turning.
[0003]
[Problems to be solved by the invention]
However, since the turning angle is detected by bringing the encoder 4 into contact with the outer peripheral portion of the turning portion 1, if a slip occurs between the encoder 4 and the outer peripheral portion of the turning portion 1, an error will occur in the detected angle of the turning portion 1. This causes a problem that the turning portion 1 cannot be turned accurately to a predetermined angle.
In addition, the encoder 4 is not directly contacted with the revolving unit 1, but an encoder is built in the motor 3, and the encoder detects the rotation angle of the drive shaft of the motor 3 and further detects the rotation angle of the revolving unit 1 from the rotation angle of the drive shaft. Can be calculated, but if a slip occurs between the turning part 1 and the drive wheel 2, it is impossible to precisely control the turning part 1 in the same manner.
Therefore, it is possible to prevent the occurrence of slip by pressing the driving wheel 2 and the encoder 4 against the turning part 1 by a spring or the like. In this case, not only the configuration of the device becomes complicated, but also Due to lack of accuracy such as roundness or the invasion of foreign matter between the drive wheel 2 and the encoder 4 and the turning part 1, there is a possibility that turning control of the turning part 1 cannot be performed with high accuracy. Was.
[0004]
The present invention has been made in order to solve such a problem, and an object of the present invention is to provide a turning mechanism capable of turning control of a turning portion with high accuracy while having a simple configuration.
[0005]
[Means for Solving the Problems]
A swivel mechanism according to the present invention is a swivel mechanism for rotating a swivel part relative to a base from a center position to a swivel position by a predetermined angle, a rotary drive device for rotating the swivel part, A magnetic sensor that rotates together with the magnetic sensor, a center position magnetic tape affixed to the base such that the magnetic pole surface of the first polarity faces the magnetic sensor when the turning unit is positioned at the center position, and the turning unit moves to the turning position. A rotation position magnetic tape attached to a base such that a magnetic pole surface of the second polarity faces the magnetic sensor when the magnetic sensor is positioned, and the rotation driving device is configured such that the magnetic sensor has a center position magnetic tape and a rotation position magnetic tape. Is accelerated or decelerated when the rotation is detected.
A dog is attached to one of the turning portion and the base, and a stop sensor for detecting the dog is attached to the other, and when the stop sensor detects the dog, the rotation drive device rotates the turning portion. It can be configured to stop.
Further, the turning position magnetic tape preferably has a length that can be detected by the magnetic sensor even when the turning portion slightly passes the turning position.
[0006]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
FIG. 1 shows a turning mechanism according to an embodiment of the present invention. An annular member 11 is formed on the base 10, and an annular member 13 of the turning portion 12 is fitted to the annular member 11 via a ball bearing, so that the turning portion 12 can freely turn with respect to the base 10. It is installed. A chain 14 is annularly stretched inside the revolving portion 12 inside the annular member 13, and a sprocket 15 meshing with the chain 14 is rotatably arranged on the base 10 and a motor for driving the sprocket 15 to rotate. 16 is fixed to the base 10. The chain 14, the sprocket 15, and the motor 16 form the rotary drive of the present invention.
[0007]
FIG. 2 shows an enlarged cross section of the end of the turning mechanism. Annular grooves facing each other are formed in the annular member 11 of the base 10 and the annular member 13 of the turning portion 12, and a ball bearing 17 is fitted between these grooves so as to roll freely. A magnetic sensor 19 is attached to the turning portion 12 via a bracket 18, and a lower end of the bracket 18 forms a dog 20 located immediately below the magnetic sensor 19. The magnetic sensor 19 and the dog 20 are connected to the turning portion 12. It is configured to rotate together with the reference numeral 12. On the other hand, a circular base 21 for supporting the annular member 11 is formed on the base 10, and a magnetic tape 22 is attached to the outer peripheral surface of the base 21 so as to face the magnetic sensor 19 of the turning part 12. ing. Further, an optical sensor 23 for detecting the dog 20 of the turning portion 12 is attached to the outer peripheral portion of the base 21.
[0008]
Here, the turning angle of the turning portion 12 is determined based on the position of the dog 20, and the state of the turning portion 12 when the dog 20 is at the position P0 as shown in FIG. Is the first turning position when the dog 20 is at the position P1 rotated +90 degrees from the position P0, and the state of the turning portion 12 when the dog 20 is at the position P2 rotated -90 degrees from the position P0. The turning position is 2.
The magnetic tape 22 attached to the outer peripheral surface of the base 21 of the base 10 has a center position magnetic tape 24 extending from +30 degrees to -30 degrees with respect to the position P0 in FIG. 1 and +60 degrees so as to include the position P1. It includes a turning position magnetic tape 25 extending from 〜 + 100 degrees and a turning position magnetic tape 26 extending from -60 degrees to -100 degrees to include the position P2. Then, the center position magnetic tape 24 is attached so that the N pole faces outward, that is, the magnetic tape 19 faces the magnetic sensor 19, and the turning position magnetic tapes 25 and 26 are attached such that the S pole faces outward. I have.
[0009]
Further, optical sensors 23 for detecting the dogs 20 of the turning portion 12 are provided at the respective positions P0, P1, and P2.
When the magnetic sensor 19 detects the N pole of the center position magnetic tape 24 or the S pole of the turning position magnetic tapes 25 and 26, the rotation of the turning portion 12 is accelerated / decelerated, and one of the optical sensors 23 The control unit (not shown) controls the motor 16 so that the rotation of the turning unit 12 is stopped when 20 is detected.
[0010]
Next, the operation of the turning mechanism according to this embodiment will be described.
First, when the optical sensor 23 installed at the position P0 detects the dog 20 of the turning part 12, it is determined that the turning part 12 is located at the center position. At this time, the N pole of the center position magnetic tape 24 is detected by the magnetic sensor 19.
Here, when turning the turning portion 12 to the first turning position by +90 degrees, the sprocket 15 is driven to rotate by the motor 16, while the magnetic sensor 19 detects the N pole of the center position magnetic tape 24. The motor 16 is controlled so that the rotation of the turning unit 12 is accelerated. That is, the acceleration section is a period until the vehicle turns +30 degrees.
[0011]
When the turning part 12 turns by +30 degrees, the N pole of the center position magnetic tape 24 is no longer detected by the magnetic sensor 19, so that the motor 16 is controlled so that the turning part 12 rotates at a constant speed. Thereafter, when the turning section 12 turns to +60 degrees, the S pole is detected by the magnetic sensor 19 this time, and it is detected that the magnetic tape 25 has reached the turning position. Then, the motor 16 is controlled so that the rotation of the turning part 12 is reduced, and the turning part 12 turns +90 degrees and the optical sensor 23 installed at the position P1 detects the dog 20 of the turning part 12, The turning unit 12 is stopped. That is, the range from +60 degrees to +90 degrees is the deceleration section. Thereby, the turning of the turning part 12 to the first turning position is completed.
[0012]
Here, since the turning position magnetic tape 25 has a length extending from +60 degrees to +90 degrees, but up to +100 degrees, even when the stop position of the turning portion 12 slightly exceeds the first turning position. Then, the magnetic sensor 19 detects the S pole of the turning position magnetic tape 25 and can accelerate the turning portion 12 in the reverse direction.
[0013]
Similarly, the turning from the first turning position to the center position and the turning between the center position and the second turning position are performed.
In the above embodiment, the turning mechanism for turning from the center position to the first turning position rotated by +90 degrees and to the second turning position rotated by -90 degrees has been described, but the present invention is not limited to this. By simply changing the positions at which the magnetic tape 22 and the optical sensor 23 are attached to the base 10, it is possible to perform turning at an arbitrary angle with high accuracy. In particular, since the magnetic tape 22 is affixed to the outer peripheral surface of the base portion 21 of the base 10, it is possible to change the acceleration / deceleration section extremely easily only by changing the length and position of the magnetic tape 22. .
[0014]
In the above embodiment, the center position magnetic tape 24 is disposed outward with the N pole as the first polarity facing the magnetic sensor 19, and the turning position magnetic tapes 25 and 26 are set as the second polarity. Although the south pole is arranged outward, the center position magnetic tape 24 is arranged so that the south pole is oriented, and the turning position magnetic tapes 25 and 26 are arranged so that the north pole is oriented outward. May be.
Further, although the optical sensor 23 is used as a stop sensor for detecting the dog 20 of the revolving unit 12, a mechanical switch can be used.
Further, in the above-described embodiment, the dog 20 is attached to the turning portion 12 and the optical sensors 23 for detecting the dog 20 are installed at the positions P0, P1, and P2 of the base 10, respectively. Dogs may be attached to the positions P0, P1, and P2 of the base 10, and a stop sensor for detecting these dogs may be installed in the turning portion 12. In this way, for example, the stop position can be detected by one stop sensor, and the number of stop sensors can be reduced.
INDUSTRIAL APPLICABILITY The present invention can be widely applied to a swivel mechanism in which the swivel angle is set in advance, such as a swivel table on a tracked truck, a turntable for branching / merging a track or a conveyor, and the like.
[0015]
【The invention's effect】
As described above, according to the present invention, the center position magnetic tape and the turning position magnetic tape are attached to the base and the magnetic sensor is attached to the turning portion, and the magnetic sensor uses the center position magnetic tape and the turning position magnetic tape. Since the rotation of the turning part is accelerated or decelerated when each is detected, it is possible to control the turning of the turning part with high accuracy while having a simple configuration.
Furthermore, if a dog is attached to the turning portion and a stop sensor for detecting the dog is attached to the base, the rotation of the turning portion can be accurately stopped when the stop sensor detects the dog.
[Brief description of the drawings]
FIG. 1 is a plan view showing a turning mechanism according to an embodiment of the present invention.
FIG. 2 is a partial cross-sectional view showing a main part of the turning mechanism according to the embodiment.
FIG. 3 is a view showing a conventional swivel table.
[Explanation of symbols]
Reference Signs List 10 base, 11, 13 annular member, 12 turning part, 14 chain, 15 sprocket, 16 motor, 17 ball bearing, 18 bracket, 19 magnetic sensor, 20 dog, 21 base part, 22 magnetic tape, 23 optical sensor, 24 Center position magnetic tape, 25, 26 Rotation position magnetic tape.

Claims (3)

In a turning mechanism for rotating the turning portion with respect to the base from a center position to a turning position by a predetermined angle,
A rotation drive device for rotating the turning part,
A magnetic sensor attached to the swivel unit and rotating with the swivel unit;
A center position magnetic tape affixed to a base such that a magnetic pole surface of a first polarity faces the magnetic sensor when the turning portion is positioned at the center position;
A turning position magnetic tape attached to a base such that a magnetic pole surface of a second polarity faces the magnetic sensor when the turning unit is located at the turning position; and A turning mechanism for accelerating and decelerating the rotation of the turning portion when the center position magnetic tape and the turning position magnetic tape are detected, respectively. A dog attached to one of the turning portion and the base, and a stop sensor attached to the other and for detecting the dog,
The turning mechanism according to claim 1, wherein the rotation driving device stops the rotation of the turning portion when the stop sensor detects the dog. The turning mechanism according to claim 1, wherein the turning position magnetic tape has a length that is detected by the magnetic sensor even when the turning portion slightly passes the turning position.

Images