JP2013160378A - Lock device and drive device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lock device securing a normal operation at a low cost and a drive device including the same.SOLUTION: A lock device includes a first magnetic body, a second magnetic body that can move between a drive part of a drive source and the first magnetic body and regulating the drive of the drive part by coming into contact with the drive part, a biasing part configured to bias a second magnetic body toward the drive part side, a first coil that can generate a magnetic force to attract the second magnetic body toward the first magnetic body side against the biasing force of the biasing part, a second coil that can generate a magnetic force to cancel a magnetic force generated by energization of the first coil, and a controller.

Description

  The present invention relates to a lock device and a drive device.

  A lock device that locks a drive unit of a drive source using an electromagnet is known. Patent Document 1 discloses an apparatus related to this. In such an apparatus, the magnetic force may remain even after the energization of the coil to the electromagnet is cut off. Due to this residual magnetic force, the locking device may not operate normally. Patent Document 1 discloses a technique that makes it difficult for a magnetic attractive force to remain between the rotor and the armature by devising the material of the rotor.

JP 2006-138370 A

  With the technique of Patent Document 1, the manufacturing cost of the rotor increases.

  Therefore, an object of the present invention is to provide a lock device that secures a normal operation at low cost and a drive device including the lock device.

  The object is to provide a first magnetic body, a second magnetic body that is movable between a drive unit of a drive source and the first magnetic body, and abuts on the drive unit and can regulate the drive of the drive unit. And an urging portion that urges the second magnetic body toward the driving portion, and a magnetic force that attracts the second magnetic body toward the first magnetic body against the urging force of the urging portion. The first coil, the second coil capable of generating a magnetic force that cancels the magnetic force generated by energizing the first coil, and the second magnetic body that is in contact with the driving unit are retracted from the driving unit. Therefore, the first coil is switched from the non-energized state to the energized state, and the second magnetic body retracted from the driving unit is brought into contact with the driving unit according to the urging force of the urging unit. The first coil is energized from the energized state to the non-energized state, and the two coils are energized from the unenergized state It said second coil and a control unit for switching the non-energized state after switching to the state can be achieved by a locking device provided with a.

  By energizing the second coil, the magnetic attractive force between the first and second magnetic bodies generated by energizing the first coil can be weakened. Thereby, the magnetic attraction force remaining between the first and second magnetic bodies can be quickly erased. Therefore, the second magnetic body can be brought into contact with the drive unit and locked.

  The above object can also be achieved by a drive device including the lock device and the drive source provided integrally with the lock device.

  ADVANTAGE OF THE INVENTION According to this invention, the locking device which ensured normal operation | movement at low cost, and a drive device provided with the same can be provided.

1A and 1B are explanatory views of a driving device. FIG. 2 is an explanatory diagram of problems of the driving device. FIG. 3A shows the drive device in which the second coil is energized, and FIG. 3B shows the drive device after the second coil is switched from the energized state to the non-energized state. FIG. 4 is a timing chart showing energization states of the first and second coils. 5A to 5C are examples of a control circuit that controls energization states of the first and second coils. FIG. 6 is an explanatory diagram of a driving device 1a according to a modification.

  1A and 1B are explanatory diagrams of the driving device 1. The drive device 1 includes a motor 10 provided with an output shaft 12, a rotating plate 20 fixed to the output shaft 12 and rotating together with the output shaft 12, a movable portion 30 through which the output shaft 12 passes and movable in the axial direction of the output shaft 12. A spring S that urges the movable part 30 toward the rotating plate 20, a fixed plate 40 fixed to the motor 10, and coils C and D disposed on the fixed plate 40 are included.

  The motor 10 is an example of a drive source. The output shaft 12 and the rotating plate 20 are an example of a drive unit. The spring S is an example of an urging portion. The spring S has a coil shape, but may have a plate spring shape. The urging portion may be rubber or the like. The movable part 30 is an example of a second magnetic body. The fixed plate 40 is an example of a first magnetic body. The coils C and D, the spring S, the movable part 30, and the fixed plate 40 are examples of a locking device. The coil C is an example of a first coil. The coil D is an example of a second coil.

  The movable portion 30 extends in the axial direction of the output shaft 12 and has a body portion 32 having a hole through which the output shaft 12 is rotatable, a lock portion 34 formed on the distal end side of the body portion 32, and the rotating plate 20. And a concave-convex engaging portion 36 formed on the surface of the lock portion 34 to be engaged. The movable part 30 is movable in the axial direction of the output shaft 12, in other words, the movable part 30 is movable between the rotating plate 20 and the fixed plate 40. The lock part 34 is formed in a disk shape. An uneven engaging portion 26 is formed on the surface of the rotating plate 20 facing the lock portion 34. The engaging part 36 of the movable part 30 and the engaging part 26 of the rotating plate 20 are engaged and meshed with each other. The fixed plate 40 is formed with a hole through which the output shaft 12 is rotatable. The movable part 30 and the fixed plate 40 are made of a magnetic material.

  The coil C is a single copper wire wound around a coil bobbin (not shown). The coil C is wound so as to surround the output shaft 12 at a distance from the output shaft 12. The coil D is a single copper wire wound around a coil bobbin (not shown). The coil D is disposed concentrically with the coil C, and is disposed outside the coil C. The coils C and D are arranged so as not to contact each other via the coil bobbin.

  Coils C and D are made of the same material. Therefore, the coils C and D have the same wire diameter and resistance value. The number of turns of the coil D is smaller than that of the coil C. The total length of the coil D is shorter than the total length of the coil C. The energization states of the coils C and D are switched by a control circuit described later. The direction of the current applied to the coil C and the direction of the current applied to the coil D are opposite. In other words, the coil D is wound in the opposite direction to the coil C. Accordingly, when the coil D is energized, a magnetic force that cancels the magnetic force generated by energizing the coil C is generated.

  One end of the spring S is fixed to the coil bobbin, and the other end is fixed to the lock portion 34. The spring S biases the movable part 30 so as to contact the rotating plate 20. The spring S is arranged in a compressed state. When the engaging portion 36 of the movable portion 30 and the engaging portion 26 of the rotating plate 20 are engaged and meshed with each other, the rotation of the rotating plate 20 is stopped. Thereby, rotation of the output shaft 12 is controlled. FIG. 1A shows the driving device 1 in a locked state in which the rotation of the output shaft 12 is restricted. In FIG. 1A, the coils C and D are in a non-energized state.

  When the coil C is energized, a magnetic flux is generated around the coil C. Thereby, the movable part 30 and the fixed plate 40 are excited, and a magnetic attractive force is generated between the movable part 30 and the fixed plate 40. When this magnetic attraction force increases more than the urging force of the spring S, the movable portion 30 retracts from the rotating plate 20 and moves to the fixed plate 40 side. Thereby, the rotation of the output shaft 12 is allowed. FIG. 1B shows the driving device 1 in an unlocked state in which the rotation of the output shaft 12 is allowed. For example, when the coil C is energized in the first direction, the distal end side of the main body portion 32 of the movable portion 30 is excited to the S pole and the proximal end side of the main body portion 32 is excited to the N pole.

  Note that the movable portion 30 and the fixed plate 40 may not be in direct contact with each other. For example, even when a cover or the like made of a nonmagnetic material is provided on the surface of the fixed plate 40, the movable portion 30 is spring S due to the magnetic attractive force generated between the movable portion 30 and the fixed plate 40. It is only necessary to be able to retract from the rotating plate 20 against the urging force.

  When the coil C is switched from the energized state to the non-energized state, the magnetic attractive force between the movable portion 30 and the fixed plate 40 disappears. Thereby, according to the urging force of the spring S, the movable portion 30 is retracted from the fixed plate 40 and comes into contact with the rotating plate 20. Thus, by switching the energization state of the coil C, the movable part 30 is driven, and the lock state and the unlock state are switched. Thus, the coil C and the fixed plate 40 function as an electromagnet.

  Next, problems that can be considered in such a drive device will be described. FIG. 2 is an explanatory diagram of problems of the driving device. Even when the power supply to the coil C is interrupted after the state shown in FIG. 1B, the movable part 30 may not return to the original position as shown in FIG. This is because a magnetic attractive force may remain between the movable portion 30 and the fixed plate 40 even after the power supply to the coil C is cut off. In this case, the rotation of the output shaft 12 cannot be restricted despite the power supply to the coil C being cut off, and the drive device 1 does not operate normally.

  Therefore, in the driving apparatus 1 of the present embodiment, the coil C is changed from the energized state to the non-energized state, and the coil D is switched from the electroless state to the energized state, and thereafter is set to the non-energized state. When the coil D is switched to the energized state, a magnetic flux is generated in a direction opposite to the direction of the magnetic flux generated by the coil C. Thereby, the magnetic attraction force remaining between the movable part 30 and the fixed plate 40 is weakened. FIG. 3A shows the driving device 1 in which the coil D is energized.

  The coil D is switched from the energized state to the non-energized state again. Accordingly, the movable portion 30 is retracted from the fixed plate 40 according to the urging force of the spring S and comes into contact with the rotating plate 20. FIG. 3B shows the driving device 1 after the coil D is switched from the energized state to the non-energized state. Thereby, the movable part 30 can be normally returned to the original position, and the output shaft 12 can be normally locked.

  If the energization state of the coil D is continued for a long period of time, the magnetic attraction force remaining between the movable portion 30 and the fixed plate 40 after the energization state of the coil C disappears, but the movable portion 30 and the fixed plate again. A magnetic attraction force is generated between 40. For example, when the coil C is energized, the distal end side of the main body 32 of the movable unit 30 is excited to the S pole and the proximal end of the main body 32 is excited to the N pole. By continuing, the distal end side of the main body 32 is excited to the N pole and the proximal end side is excited to the S pole. Thereby, even when the coil D is switched from the energized state to the non-energized state, there is a possibility that the magnetic attractive force remains between the movable portion 30 and the fixed plate 40. Accordingly, it is desirable that the duration of the energized state of the coil D is only a period necessary for the magnetic attraction force generated when the coil C is energized to be weakened.

In the above example, both the coils C and D are in the non-energized state between the energized state of the coil C and the energized state of the coil D, but the present invention is not limited to this. For example, if there is no problem with the drive circuit that controls the energization states of the coils C and D, the coil D may be switched from the non-energized state to the energized state while the coil C is switched from the energized state to the non-conductive state. That is, the order of switching the coil C from the energized state to the non-energized state and the timing of switching the coil D from the non-energized state to the energized state are not limited.
For example, this is possible when control circuits for controlling the energization state of the coils C and D are separately provided. Further, the coil D may be switched between the energized state and the non-energized state a plurality of times while the drive device 1 is shifted from the unlocked state to the locked state.

  FIG. 4 is a timing chart showing the energization state of the coils C and D. FIG. 4 shows the energized state of the coil C when the driving device 1 shifts from the locked state to the unlocked state and then shifts to the locked state. For example, when an operation signal is input to the controller that controls the energization of the coils C and D, the controller issues a command to the control circuit (control unit) that controls the energization state of the coils C and D, and the coil C is turned off. Switch from energized state to energized state. Thereby, the drive device 1 is switched from the locked state to the unlocked state as shown in FIG. 1B.

  When a stop signal is input to the controller, the controller switches the coil C from the energized state to the non-energized state, and then switches the coil D from the non-energized state to the energized state. As a result, the magnetic attraction force remaining between the movable portion 30 and the fixed plate 40 is weakened as shown in FIG. 3A. Thereafter, when the coil D is switched to the non-energized state, the driving device 1 is again locked as shown in FIG. 3B. In addition, even if it adjusts so that the electric current amount in the coil D may become smaller than the electric current amount in the coil C per unit time by adjusting the duty ratio of the pulse applied to each of the coils C and D. Good.

  5A to 5C are examples of the control circuit 100 that controls the energization states of the coils C and D. FIG. The control circuit 100 is an example of a control unit. 5A shows the control circuit 100 when the coils C and D are not energized, FIG. 5B shows the control circuit 100 when the coil C is energized, and FIG. 5C shows the control circuit 100 when the coil D is energized. Yes. The control circuit 100 includes transistors T1 and T2. The coil C is connected between the power supply potential VDD and the transistor T1. The coil D is connected between the power supply potential VDD and the transistor T2. The transistor T1 is connected between one end of the coil C and the ground potential. The transistor T2 is connected between one end of the coil D and the ground potential.

  When the input signal 1s is supplied to the transistor T1, a current flows through the coil C as shown in FIG. 5B. When the input signal 1s to the transistor T1 is cut off, the coil C is turned off. By supplying the input signal 2s to the transistor T2, a current flows through the coil D as shown in FIG. 5C. When the input signal 2s to the transistor T2 is cut off, the coil D enters a non-energized state. In this embodiment, the coil D is energized after the coil C is switched to the non-energized state, and the coils C and D are made of the same material, so the same voltage is applied to the coils C and D. The control circuit 100 is an example of a circuit that can switch the energization state of the coils C and D, and is not limited to such a circuit.

  As described above, the magnetic attractive force remaining between the movable portion 30 and the fixed plate 40 can be weakened by energizing the coil D after the energization of the coil C is interrupted. Thereby, compared with the case where the said problem is solved by changing the material of the movable part 30 and the stationary plate 40, it can prevent that magnetic force remains at low cost.

  The coils C and D are made of the same material but have a different number of turns. For this reason, even when the same power is applied to both the coils C and D, the magnetic force generated around the coil D is weaker than the magnetic force generated around the coil C. Therefore, for example, a weak magnetic force that weakens the residual magnetic force can be generated by energizing the coil D without adjusting the power applied to the coils C and D, respectively. Therefore, a control circuit that controls the energization state of the coils C and D can be manufactured at low cost.

  FIG. 6 is an explanatory diagram of a driving device 1a according to a modification. The coils Ca and Da are arranged so as to overlap in the direction of the rotating shaft 12. The coil Da is disposed between the coil Ca and the fixed plate 40. The coil Da has fewer turns than the coil Ca. In this way, the coils Ca and Da may be arranged.

  In the drive device 1, the coil D is wound outside the coil C, but the coil D may be wound inside the coil C. In the driving device 1a, the coil Da is disposed below the coil Ca. However, the coil Da may be disposed on the coil Ca.

  The number of windings, the total length, the wire diameter, and the material of the coils C and D are not limited to those described above. If the magnetic force generated by the coil C when the same power is applied to the coils C and D is larger than the magnetic force generated by the coil D, the number of windings, the total length, the wire diameter, and the material of the coils C and D are not limited.

  The drive device 1 of the present embodiment can be used for, for example, a printer, a machine tool, an automobile, a shutter device, a portable device, an automatic opening / closing door, a home appliance, and the like. The drive source is not limited to a motor, for example, and may be an engine. The locking device may not be provided integrally with the drive unit.

  Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited to such specific embodiments, and modifications and changes can be made within the scope of the gist of the present invention described in the claims. Is possible.

1 Drive device 10 Motor (drive source)
12 Output shaft (drive unit)
20 Rotating plate (drive unit)
26 engaging portion 30 movable portion 32 body portion 34 locking portion 36 engaging portion 100 control circuit (control portion)
C coil (first coil)
D coil (second coil)
S Spring (Biasing part)
T1, T2 transistors

Claims (3)

A first magnetic body;
A second magnetic body that is movable between a drive unit of a drive source and the first magnetic body and that can contact the drive unit and restrict the drive of the drive unit;
An urging portion for urging the second magnetic body toward the drive portion;
A first coil capable of generating a magnetic force that attracts the second magnetic body toward the first magnetic body against the urging force of the urging portion;
A second coil capable of generating a magnetic force that cancels the magnetic force generated by energizing the first coil;
In order to retract the second magnetic body in contact with the drive unit from the drive unit, the first coil is switched from a non-energized state to an energized state, and the second magnetic body is retracted from the drive unit. After the first coil is switched from the energized state to the non-energized state and the two coils are switched from the non-energized state to the energized state, the second coil is brought into contact with the drive unit according to the urging force of the urging unit. And a control unit that switches to a non-energized state.   The locking device according to claim 1, wherein when the same electric power is applied to the first and second coils, the magnetic force generated by the first coil is larger than the magnetic force generated by the second coil. The locking device according to claim 1;
And a driving device provided integrally with the locking device.

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