JP2017064846A - Robot and control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a robot that can reduce noise, and to provide a control device.SOLUTION: The robot includes a switching part 35 for switching a voltage to an electromagnetic brake 21 for braking a movable part. The switching part 35 includes a passive element 47 to switch a voltage applied to the electromagnetic brake 21 from a first voltage to a second voltage that is lower than the first voltage based on a time constant of the passive element 47.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a robot and a control device.

  In a non-excitation operation type electromagnetic brake used in a servo motor or the like, in a non-excitation state, the armature is urged toward the motor rotating shaft by the spring force, and the braking force is applied. When excited, the armature is attracted toward the yoke by the magnetic attraction force, and the braking force acting on the motor rotation shaft is released. When the armature is attracted to the yoke, a large amount of electric power is required. However, after the armature has attracted the yoke, less power is required to keep the armature in the attracted state. That is, less power is required to maintain the armature suction holding state for maintaining the brake-free state.

  In Patent Document 1, as shown in FIG. 8, overexcitation and holding of an electromagnetic brake are switched by switching a duty ratio of a supply voltage (for example, 24 V).

JP 2009-14196 A

  However, in Patent Document 1, since the supply voltage is switched in a fine cycle (for example, 24V → 0V → 24V), noise generation may increase.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

  Application Example 1 A robot according to this application example includes a switching unit that switches a voltage to an electromagnetic brake that brakes the movable unit, and the switching unit includes a passive element, based on a time constant of the passive element. The voltage applied to the electromagnetic brake is switched from the first voltage to a second voltage lower than the first voltage.

  According to this application example, an overexcitation voltage (first voltage) that is a large voltage is applied, and when a predetermined time elapses, the voltage is switched to a holding voltage (second voltage) that is lower than the overexcitation voltage that is a holding state voltage. Thereby, an overexcitation voltage and a holding voltage can be switched automatically. As a result, noise can be reduced.

  Application Example 2 In the robot according to the application example described above, the switching unit is located between a first voltage application unit that applies the first voltage and the electromagnetic brake, and a magnitude of a voltage of the passive element. Based on the above, it is preferable to have a switching element that is turned on and off.

  According to this application example, the switching element can be turned on and off between the first voltage application unit and the electromagnetic brake.

  Application Example 3 In the robot according to the application example described above, it is preferable that the switching unit includes a first diode that allows a current to flow from the switching element toward the electromagnetic brake.

  According to this application example, the first voltage and the second voltage can be selected. In addition, when the induced voltage of the electromagnetic brake becomes higher than the power supply voltage, it is possible to prevent the current caused by the high induced voltage from flowing back from the electromagnetic brake to the switching element.

  Application Example 4 In the robot according to the application example described above, the switching element is preferably a PMOS transistor.

  According to this application example, switching can be performed with a relatively small number of elements by using a PMOS transistor as a switching element.

  Application Example 5 In the robot according to the application example, it is preferable that the switching unit includes a second voltage application unit that generates the second voltage.

  According to this application example, it is possible to more reliably extract the second voltage.

  Application Example 6 In the robot according to the application example described above, it is preferable that the switching unit includes a second diode that allows a current to flow from the second voltage application unit toward the electromagnetic brake.

  According to this application example, the first voltage and the second voltage can be selected. In addition, when the induced voltage of the electromagnetic brake becomes higher than the power supply voltage, it is possible to prevent the current caused by the high induced voltage from flowing backward from the electromagnetic brake to the second voltage application unit.

  Application Example 7 In the robot according to the application example described above, it is preferable that the second voltage application unit transforms the first voltage into the second voltage.

  According to this application example, it is possible to more reliably extract the second voltage.

  Application Example 8 In the robot according to the application example described above, it is preferable that the switching unit includes a third diode that allows current to flow from the passive element toward the first voltage application unit.

  According to this application example, a current due to the capacitance voltage of the passive element can flow from the passive element to the first voltage application unit.

  Application Example 9 In the robot according to the application example described above, it is preferable that the passive element includes a resistor and a capacitor.

  According to this application example, a circuit having a time constant can be realized with a simple configuration.

  Application Example 10 In the robot according to the application example described above, it is preferable that two or more resistors are provided.

  According to this application example, the voltage of the passive element applied to the switching element can be freely divided by a combination of two or more resistors.

  Application Example 11 A control device according to this application example includes a switching unit that switches a voltage to an electromagnetic brake that brakes the movable unit, and the switching unit includes a passive element and is based on a time constant of the passive element. The voltage applied to the electromagnetic brake is switched from the first voltage to a second voltage lower than the first voltage.

  According to this application example, an overexcitation voltage (first voltage) that is a large voltage is applied, and when a predetermined time elapses, the voltage is switched to a holding voltage (second voltage) that is lower than the overexcitation voltage that is a holding state voltage. Thereby, an overexcitation voltage and a holding voltage can be switched automatically. As a result, noise can be reduced.

Explanatory drawing which shows the structure of the motor unit which concerns on 1st Embodiment. The schematic cross section which shows the structure of the electromagnetic brake which concerns on 1st Embodiment, (A) is the state which is braking (it applies the brake), (B) is the state which is not braking (the brake is not applied). The connection diagram which shows the circuit structure of the switch part which concerns on 1st Embodiment. The voltage and current waveform diagram of the excitation current of the electromagnetic brake according to the first embodiment. The connection diagram which shows the circuit structure of the switch part which concerns on 2nd Embodiment. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory diagram illustrating an overall configuration of a robot system according to an embodiment. Explanatory drawing which shows the example of arrangement | positioning of the motor unit in the arm part which concerns on this embodiment. The voltage and current waveform diagram of the excitation current of a conventional electromagnetic brake.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, embodiments of the invention will be described with reference to the drawings. Note that the drawings to be used are appropriately enlarged or reduced so that the part to be described can be recognized.

(First embodiment)
(Motor unit)
First, the motor unit 1 will be described with reference to FIG.
Drawing 1 is an explanatory view showing the composition of motor unit 1 concerning an embodiment. As shown in FIG. 1, the motor unit 1 includes a motor (drive unit) 11, an encoder 15, an electromagnetic brake 21, a pulley 31, and a motor plate 3. The motor 11 and the electromagnetic brake 21 are fixed to the motor plate 3, and the motor unit 1 is attached to the robot 51 by fixing the motor plate 3 to the robot 51 (see FIG. 6).

  The motor 11 has a substantially cylindrical outer shape and includes an output shaft 12. The output shaft 12 protrudes from one end of the substantially cylindrical shape of the motor 11. A shaft hole 3 a is formed in the motor plate 3. With the output shaft 12 passing through the shaft hole 3a, the end surface of the motor 11 is in contact with the motor plate 3, and the motor 11 is fixed to the motor plate 3 by a fixing member (not shown). An encoder 15 is fixed to the end surface of the motor 11 opposite to the end surface fixed to the motor plate 3.

  An electromagnetic brake 21 is disposed on the opposite surface of the motor plate 3 to which the motor 11 is fixed. The electromagnetic brake 21 is fixed to the motor plate 3 by fixing members constituting the electromagnetic brake 21 to the output shaft 12 protruding through the motor plate 3 or the shaft hole 3a. Details of the configuration of the electromagnetic brake 21 will be described later.

  The pulley 31 includes a pulley hub 33 and a pulley body 34. The pulley hub 33 has a shape in which two discs having different outer diameters are integrated with a central axis and an attachment hole is formed at the central position. The pulley hub 33 is fixed to the output shaft 12 by a fixing member (not shown) with the mounting hole fitting into the output shaft 12. The pulley body 34 has a pulley disk 34a and a pulley wheel 34b. The pulley disk 34a has a disk shape with a fitting hole formed in the center. The pulley wheel 34b has a cylindrical shape. One end of the cylindrical shape of the pulley wheel 34b is fitted onto the pulley disk 34a, and the pulley disk 34a and the pulley wheel 34b are integrated to form a pulley body 34. The integrated pulley disk 34a and pulley wheel 34b form a substantially cylindrical space. The pulley ring 34b is fixed to the pulley hub 33 by a fixing member (not shown) in a state where the fitting hole of the pulley disk 34a is fitted on the pulley hub 33, and the pulley 31 is formed.

  The pulley 31 is fixed to the output shaft 12 with the opening of the substantially cylindrical space facing the motor plate 3. The pulley 31 is provided with an electromagnetic brake 21 in a substantially cylindrical space.

(Electromagnetic brake)
Next, the electromagnetic brake 21 constituting the motor unit 1 will be described with reference to FIG.
FIG. 2 is a schematic cross-sectional view showing the configuration of the electromagnetic brake 21 according to the embodiment. FIG. 2A is a schematic cross-sectional view showing the electromagnetic brake 21 in a state where the brake is applied (the brake is applied), and FIG. 2B is an electromagnetic wave in the state where the brake is not applied (the brake is not applied). 2 is a schematic cross-sectional view showing a brake 21. FIG.

  As shown in FIG. 2, the electromagnetic brake 21 includes a brake plate 22, a movable plate 26, an electromagnet 28, and a brake spring 29. The fixed frame 27 has a shape in which one end of a cylinder is closed by a disk, and a columnar column space 27b having one end opened is formed. A surface of the disk portion of the fixed frame 27 facing the cylindrical space 27b is referred to as a fixed surface 27a. A hole is formed in the center of the disk, and the fixed frame 27 is fixed to the motor plate 3 in a state where the output shaft 12 passes through the hole and the opening of the cylindrical space is blocked by the motor plate 3. Yes. In a state where the fixed frame 27 is fixed to the motor plate 3, the surface direction of the fixed surface 27 a is a direction substantially orthogonal to the axial direction of the output shaft 12.

  The brake plate 22 has a brake hub 23 and a friction plate 24. The brake hub 23 has a shape in which two discs having different outer diameters are integrated with a central axis and an engagement hole is formed in the central axis. The friction plate 24 has a cylindrical shape with a fitting hole formed in the center. The friction plate 24 is integrated with the brake hub 23 by fitting a fitting hole to the outer diameter of the brake hub 23. The brake hub 23 is locked to the output shaft 12 through the engagement hole of the output shaft 12. A key groove (not shown) is formed in the engagement hole and the output shaft 12. The brake hub 23 is slidable in the axial direction of the output shaft 12 with respect to the output shaft 12 by the key engaged with both key grooves, and the rotation of the output shaft 12 in the circumferential direction is substantially prohibited. The output shaft 12 is locked. The friction plate 24 fixed to the brake hub 23 is such that the surface direction of the plate surface is substantially orthogonal to the axial direction of the output shaft 12. The brake plate 22 is located in the cylindrical space 27 b of the fixed frame 27 fixed to the motor plate 3, and one surface of the friction plate 24 faces the fixed surface 27 a of the fixed frame 27.

  The electromagnet 28 has a cylindrical shape. The electromagnet 28 is located in the cylindrical space 27 b, the output shaft 12 passes through the center hole, and one end of the cylindrical shape is in contact with the motor plate 3 and is fixed to the motor plate 3. The opposite end of the electromagnet 28 in contact with the motor plate 3 is the attracting surface of the electromagnet 28.

  The movable plate 26 has a disk shape with a hole formed in the center. The movable plate 26 is located between the electromagnet 28 and the friction plate 24, and both surfaces of the disk are opposed to the attracting surface of the electromagnet 28 or the friction plate 24, respectively. Near the side wall of the cylindrical space 27b, a plurality of guide shafts 25 are passed to the frame of the electromagnet 28 from near the periphery of the disk portion of the fixed frame 27. The movable plate 26 is supported so that holes formed in the vicinity of the movable plate 26 engage with the guide shafts 25 so as to be slidable in the axial direction of the output shaft 12. The movable plate 26 is made of a magnetic material and can be attracted by an electromagnet 28. Examples of the magnetic material include iron, iron-based alloys, and magnetic stainless steel.

  As for the brake spring 29, a plurality of brake springs 29 are arranged around the attracting surface of the electromagnet 28. One end of the brake spring 29 is fixed by fitting into a recess formed in a frame around the attracting surface of the electromagnet 28. The other end of the brake spring 29 is in contact with the movable plate 26 and biases the movable plate 26 toward the friction plate 24.

  FIG. 2 (A) shows a state in which the electromagnetic brake 21 is braking (braking). As shown in FIG. 2A, the brake spring 29 biases the movable plate 26 toward the friction plate 24. The brake plate 22 having the movable plate 26 and the friction plate 24 is slidable in the axial direction of the output shaft 12. When the movable plate 26 is biased toward the friction plate 24, the movable plate 26 moves and abuts against the friction plate 24, and the friction plate 24 (brake plate 22) fixes the disk portion of the fixed frame 27. It abuts on the surface 27 a and is pressed with a force corresponding to the urging force of the brake spring 29. The relative position between the fixed frame 27 and the motor 11 is fixed via the motor plate 3. The brake hub 23 to which the friction plate 24 is fixed is substantially prohibited from rotating in the circumferential direction of the output shaft 12 with respect to the output shaft 12 and is locked to the output shaft 12. The friction plate 24 is pressed against the fixed surface 27a of the fixed frame 27 with a force according to the urging force of the brake spring 29, whereby the rotation of the output shaft 12 is braked.

  FIG. 2 (B) shows a state in which the electromagnetic brake 21 is not braked (not braked). As shown in FIG. 2B, the electromagnet 28 attracts the movable plate 26 against the urging force of the brake spring 29. Since the state where the friction plate 24 is pressed against the fixed surface 27a by the urging force of the brake spring 29 is released, the state where the rotation of the output shaft 12 is braked is released.

  The mechanical emergency stop means is one of mechanical resistance, an electromagnetic brake composed of a coil and a solenoid, a regenerative brake by a regenerative current of a motor that drives the robot, or a combination thereof.

FIG. 3 is a connection diagram illustrating a circuit configuration of the switching unit 35 according to the embodiment.
In the present embodiment, the control device 52 (see FIG. 6) includes a switching unit 35 that switches a voltage to the electromagnetic brake 21 that brakes the movable unit. The electromagnetic brake 21 is connected to a power source (first voltage application unit) 37 via a switching unit 35. The electromagnetic brake 21 is turned on and off by the current flowing through the electromagnetic brake 21.

  The switching unit 35 is preferably located between the first voltage applying unit 37 that applies the first voltage and the electromagnetic brake 21. According to this, the switching element 36 can turn on and off between the first voltage application unit 37 and the electromagnetic brake 21. In the present embodiment, the switching unit 35 is provided in the control device 52, but may be incorporated in the electromagnetic brake 21, may be incorporated in the motor 11, or may be externally attached to the motor 11. .

  The switching unit 35 includes a passive element 47, a switching element 36, a holding voltage creation unit (second voltage application unit) 38, and a voltage selection unit 49.

  The passive element 47 preferably includes a resistor 42 and a capacitor 43. The resistor 42 is connected between the source terminal S and the gate terminal G of the switching element 36, and the capacitor 43 is connected between the gate terminal G of the switching element 36 and the ground. The passive element 47 constitutes a time constant circuit 44 that applies a voltage that varies with a time constant based on the capacitor 43 and the resistor 42 to the gate terminal G of the switching element 36. The overexcitation time is set by the time constant circuit 44. The overexcitation time is set by the time constant of the resistor 42 and the capacitor 43. According to this, the time constant circuit 44 can be realized with a simple configuration.

  When the power is turned on, the time constant circuit 44 gradually increases the charging voltage of the capacitor 43 with a time constant determined by the capacitance of the capacitor 43 and the value of the resistor 42 to suppress a sudden rise in the charging voltage. This is given as the gate voltage of the switching element 36. When the capacitor 43 is charged, the voltage of the capacitor 43 acts on the gate terminal G of the switching element 36 as a gate voltage, so that the switching element 36 is turned off. The resistance value of the resistor 42 is, for example, 200 kΩ. The capacitance value of the capacitor 43 is, for example, 2.2 μF. The switching unit 35 switches the voltage applied to the electromagnetic brake 21 from the first voltage to a second voltage lower than the first voltage based on the time constant of the passive element 47. Although the capacitor 43 is directly discharged to the ground, it may be discharged via a resistor.

  The switching element 36 is preferably turned on / off based on the voltage level of the passive element 47. According to this, the switching element 36 can turn on and off between the first voltage application unit 37 and the electromagnetic brake 21.

  As a voltage of the first voltage application unit 37, for example, DC 24V is appropriate. The voltage value of the overexcitation voltage (Vout) is, for example, 24V. The current value of the overexcitation current (Iout) is, for example, 300 mA. The overexcitation time is, for example, 200 ms.

  The switching element 36 is preferably a PMOS transistor (p-type MOSFET). According to this, by using a PMOS transistor as the switching element 36, switching can be performed with a relatively small number of elements.

  The holding voltage generator 38 preferably generates a holding voltage (second voltage) (Vout). According to this, the holding voltage (Vout) can be taken out more reliably. The voltage value of the holding voltage (Vout) is, for example, 8V. The current value of the holding current (Iout) is, for example, 100 mA.

  The holding voltage creating unit 38 preferably transforms the first voltage supplied from the first voltage applying unit 37 into the second voltage. According to this, the holding voltage (Vout) can be taken out more reliably. The holding voltage generator 38 may transform the voltage supplied from the outside to the second voltage.

  The voltage selection unit 49 includes two first and second diodes 39 and 40. The voltage selection unit 49 selects the higher voltage among the voltages applied to the first diode 39 and the second diode 40 so as to be applied to the electromagnetic brake 21.

  The voltage selection unit 49 preferably includes a first diode 39 between the switching element 36 and the electromagnetic brake 21. The first diode 39 allows current to flow from the switching element 36 toward the electromagnetic brake 21. According to this, the overexcitation voltage (Vout) and the holding voltage (Vout) can be easily selected. Further, when the induced voltage of the electromagnetic brake 21 becomes higher than the power supply voltage, it is possible to prevent the current caused by the high induced voltage from flowing backward from the electromagnetic brake 21 to the switching element 36.

  The voltage selection unit 49 preferably includes the second diode 40 between the holding voltage generation unit 38 and the electromagnetic brake 21. The second diode 40 causes a current to flow from the holding voltage generator 38 toward the electromagnetic brake 21. According to this, the overexcitation voltage (Vout) and the holding voltage (Vout) can be easily selected. Further, when the induced voltage of the electromagnetic brake 21 becomes higher than the power supply voltage, it is possible to prevent a current caused by the high induced voltage from flowing backward from the electromagnetic brake 21 to the holding voltage creating unit 38.

  By providing the first diode 39 and the second diode 40, the higher voltage applied to each diode is applied to the electromagnetic brake 21. When the switching element 36 is on, an overexcitation voltage (Vout) is applied to the electromagnetic brake 21 via the first diode 39. When the switching element 36 is off, the holding voltage (Vout) is applied to the electromagnetic brake 21 via the second diode 40.

  The switching unit 35 may include a third diode 41 between the passive element 47 and the first voltage application unit 37. The third diode 41 causes a current to flow from the passive element 47 to the first voltage application unit 37. According to this, the electric current resulting from the capacitive voltage of the passive element 47 can be made to flow from the passive element 47 to the first voltage application unit 37, and the on / off of the first voltage application unit 37 can be switched at high speed.

  The electromagnetic brake 21 is provided with a diode, which is also referred to as a free-wheeling diode that is parallel to the coil, with the direction from the ground side to the power supply side as the forward direction, and prevents the occurrence of surge.

FIG. 4 is a voltage and current waveform diagram of the excitation current of the electromagnetic brake 21 according to the embodiment.
A first voltage (overexcitation voltage (Vout)) is applied to the first voltage application unit 37 of the switching unit 35, and the capacitor 43 is charged accordingly. The charging voltage of the capacitor 43 gradually increases according to the time constant of the time constant circuit 44, and this capacitor 43 is given as the gate voltage of the switching element 36. When the gate voltage gradually rises and exceeds the gate threshold voltage of the switching element 36, the switching element 36 is turned off and the drain current is cut off, which is cut off as the overexcitation current (Iout) of the electromagnetic brake 21. When the overexcitation current (Iout) is cut off, the voltage selection unit 49 selects the holding voltage (Vout) transformed from the first voltage to the second voltage by the holding voltage generation unit 38. The selected holding voltage (Vout) is applied to the electromagnetic brake 21 and flows as a holding current (Iout).

  According to this embodiment, an overexcitation voltage (first voltage) (Vout), which is a large voltage, is input to the first voltage application unit 37. Based on the time constant of the passive element 47, when a certain time has elapsed, the voltage is switched to a holding voltage (second voltage) (Vout) that is a holding state voltage. Thereby, the overexcitation current (Iout) and the holding current (Iout) can be automatically switched. As a result, noise can be reduced.

(Second Embodiment)
FIG. 5 is a connection diagram illustrating a circuit configuration of the switching unit 45 according to the present embodiment.
The passive element according to the present embodiment is different from the first embodiment in that it is composed of two resistors and one capacitor. Hereinafter, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted or simplified here.

  The switching unit 45 according to the present embodiment includes a passive element 48. The passive element 48 includes a first resistor 42, a second resistor 46, and a capacitor 43. According to this, the voltage of the passive element 48 applied to the switching element 36 can be freely divided by a combination of two or more resistors. The resistance value of the first resistor 42 is, for example, 150 kΩ. The resistance value of the second resistor 46 is, for example, 50 kΩ. The capacitance value of the capacitor 43 is, for example, 2.2 μF.

(robot)
Next, the configuration of the robot 51 constituting the robot system 50 will be described with reference to FIGS.
FIG. 6 is an explanatory diagram showing the overall configuration of the robot system 50 according to the present embodiment. As shown in FIG. 6, the robot system 50 includes a robot 51 and a control device 52. The control device 52 controls the robot 51 in accordance with a program inputted in advance, and performs a predetermined work defined by the program.

  The control device 52 includes a switching unit 35 (switching unit 45) that switches a voltage to the electromagnetic brake 21 that brakes the movable unit. In the present embodiment, the switching unit 35 (switching unit 45) is provided in the control device 52, but may be incorporated in the electromagnetic brake 21 of the robot 51 or may be incorporated in the motor 11 of the robot 51. The motor 11 may be externally attached.

  The robot 51 is a so-called vertical articulated robot. The robot 51 includes a base 53, a rotation base 54, a first arm (movable part) 55, an arm swing base 56, a second arm (movable part) 57, a tip swing base 58, and a tip. And an arm (movable part) 59.

  The robot 51 is configured by assembling other members on a base 53. The robot 51 is installed on the floor or the like by fixing the base 53 to the floor or the like. The rotation base 54 is supported by the base 53 so as to be rotatable about a base rotation shaft 54a substantially perpendicular to the installation surface. One end of the first arm 55 is supported by the rotation base 54. The first arm 55 is supported by the rotation base 54 so as to be swingable about a first swing shaft 55a whose axial direction is substantially perpendicular to the axial direction of the base rotation shaft 54a. An arm swing base 56 is supported on the tip end side of the first arm 55 that is swung around the first swing shaft 55a. The arm swing base 56 is supported by the first arm 55 so as to be rotatable about a second swing shaft 56a substantially parallel to the first swing shaft 55a. One end of the second arm 57 is supported on the arm swing base 56. As the arm swing base portion 56 rotates about the second swing shaft 56a, the second arm 57 swings about the second swing shaft 56a. The second arm 57 is supported by the arm swing base 56 so as to be rotatable about a second rotation shaft 57a whose axial direction is substantially perpendicular to the axial direction of the second swing shaft 56a. The extending direction of the second arm 57 is substantially the axial direction of the second rotating shaft 57a.

  A tip swing base 58 is supported on the distal end side of the second arm 57 that is swung around the second swing shaft 56a. The tip swing base 58 is rotatably supported by the second arm 57 about a tip swing shaft 58a whose axial direction is substantially perpendicular to the axial direction of the second rotation shaft 57a. One end of a tip arm 59 is supported on the tip swing base 58. The tip swing base 58 pivots about the tip swing shaft 58a, so that the tip arm 59 swings about the tip swing shaft 58a. The tip arm 59 is supported by the tip swing base 58 so as to be rotatable about a tip rotation shaft 59a whose axial direction is substantially perpendicular to the axial direction of the tip swing shaft 58a. The extending direction of the tip arm 59 is substantially the axial direction of the tip turning shaft 59a. An attachment mechanism (not shown) is disposed at the distal end of the distal arm 59, and the end effector is attached to the robot 51 through the attachment mechanism.

  The base 53 is provided with a motor unit (not shown) for rotating the rotation base 54 around the base rotation shaft 54a. A motor unit (not shown) for swinging the first arm 55 around the first swing shaft 55a and an arm swing base 56 around the second swing shaft 56a are rotated on the first arm 55. A motor unit (not shown) for causing the second arm 57 to swing about the second swing shaft 56a, and for rotating the second arm 57 about the second rotation shaft 57a. A motor unit (not shown) is provided. Each motor unit has basically the same configuration as the motor unit 1.

  FIG. 7 is an explanatory diagram showing an arrangement row of the motor units 60 and 70 in the arm portion according to the present embodiment. As shown in FIG. 7, a motor unit 60 and a motor unit 70 are disposed on the arm frame 571 constituting the second arm 57. The motor unit 60 constitutes a swing unit 60A for swinging the tip arm 59 about the tip swing shaft 58a by turning the tip swing base 58 around the tip swing shaft 58a. The motor unit 70 constitutes a turning unit 70A for turning the tip arm 59 around the tip turning shaft 59a. The motor unit 60 and the motor unit 70 have basically the same configuration as the motor unit 1.

  The swing unit 60 </ b> A includes a motor unit 60, a swing body pulley 62, a swing belt 65, and a swing base shaft 64. The motor unit 60 includes a swing motor (drive unit) 61, a swing pulley 63, and an electromagnetic brake 21 (not shown). The motor unit 60 is fixed to the arm frame 571 so that the axial direction of the output shaft 12 included in the motor unit 60 is substantially parallel to the axial direction of the tip swing shaft 58a. The swing body pulley 62 is fixed to the tip swing base 58 via the swing base shaft 64 at a position that rotates around the tip swing shaft 58a. The swinging pulley 62 and the swinging pulley 63 of the motor unit 60 are located at substantially the same position in the axial direction of the tip swinging shaft 58a. A swing belt 65 is stretched between the swing body pulley 62 and the swing pulley 63.

  When the swing motor 61 is operated, the swing pulley 63 is rotated. The rotation of the swing pulley 63 is transmitted to the swing body pulley 62 via the swing belt 65, and the swing body pulley 62 is rotated in synchronization with the swing of the swing pulley 63. By rotating the swinging body pulley 62, the tip swing base 58 to which the swinging pulley 62 is fixed rotates around the tip swinging shaft 58a. The tip arm 59 supported by the tip swing base 58 is swung around the tip swing shaft 58a.

  The rotation unit 70A includes a motor unit 70, a rotation body pulley 72, a rotation belt 75, a rotation transmission shaft 74, a rotation transmission gear 76a, a rotation transmission gear 76b, and a tip arm shaft 79. I have. The motor unit 70 includes a rotation motor (drive unit) 71 and a rotation pulley 73. The motor unit 70 is fixed to the arm frame 571 so that the axial direction of the output shaft 12 provided in the motor unit 70 is substantially parallel to the axial direction of the tip swing shaft 58a. The motor unit 70 is arranged side by side with the motor unit 60. The motor unit 70 and the motor unit 60 are arranged in a direction in which the rotating pulley 73 in the motor unit 70 and the swinging pulley 63 of the motor unit 60 are located on the opposite side in the axial direction of the tip swinging shaft 58a. Has been.

  The rotation transmission shaft 74 is disposed on the side where the oscillating body pulley 62 is fixed and the opposite side in the axial direction of the tip oscillating shaft 58a in the tip oscillating base 58. The rotation transmission shaft 74 extends from the inside of the tip swing base 58 to the tip of the arm frame 571. The rotation transmission shaft 74 has a center of rotation substantially coincident with the tip swing shaft 58a, and is supported rotatably with respect to the arm frame 571 independently of the shaft that supports the tip swing base 58. ing. The rotating body pulley 72 is fixed to the tip of the rotation transmitting shaft 74 on the arm frame 571 side at a position that rotates about the tip swing shaft 58a. The rotating pulley 72 and the rotating pulley 73 of the motor unit 70 are located at substantially the same position in the axial direction of the tip swing shaft 58a. A rotating belt 75 is stretched between the rotating body pulley 72 and the rotating pulley 73. The rotation transmission gear 76 a is fixed to the tip on the inner side of the tip swing base 58 in the rotation transmission shaft 74. The rotation transmission gear 76b is fixed to the tip of the tip arm shaft 79 and meshes with the rotation transmission gear 76a. The tip arm shaft 79 has one end on the opposite side to which the rotation transmission gear 76b is fixed fixed to the tip arm 59, and the center of rotation substantially coincides with the tip rotation shaft 59a. The rotation transmission gear 76a and the rotation transmission gear 76b are bevel gears, and the axis of the tip arm shaft 79 and the axis of the rotation transmission shaft 74 are substantially orthogonal.

  When the rotation motor 71 is operated, the rotation pulley 73 is rotated. The rotation of the rotation pulley 73 is transmitted to the rotation body pulley 72 via the rotation belt 75, and the rotation body pulley 72 is rotated periodically with the rotation of the rotation pulley 73. By rotating the rotating body pulley 72, the rotation transmitting shaft 74 to which the rotating body pulley 72 is fixed rotates around the tip swing shaft 58a. When the rotation transmission shaft 74 is rotated, the tip arm shaft 79 is rotated via the rotation transmission gear 76a and the rotation transmission gear 76b, and the tip arm 59 to which the tip arm shaft 79 is fixed is It is turned around the tip turning shaft 59a. The tip swing base 58 and the tip arm 59 correspond to a driven body.

  A rotation unit including a motor unit for rotating the rotation base 54 and a rotation unit including a motor unit for rotating the second arm 57 have the same configuration as the rotation unit 70A. . A swing unit including a motor unit for swinging the first arm 55 and a swing unit including a motor unit for swinging the second arm 57 by rotating the arm swing base 56 are swings. It has the same configuration as the unit 60A.

  The robot of the present invention is not limited to a vertical articulated robot, and the same effect can be obtained with a horizontal articulated robot, a parallel link robot, a double-arm robot, or the like. The robot of the present invention is not limited to a 6-axis robot, and the same effect can be obtained with a robot with 7 or more axes or a robot with 5 or less axes. The robot of the present invention is not limited to an arm type robot (robot arm) as long as it has an arm, and may be another type of robot, for example, a legged walking (running) robot.

  DESCRIPTION OF SYMBOLS 1 ... Motor unit 3 ... Motor plate 3a ... Shaft hole 11 ... Motor (drive part) 12 ... Output shaft 15 ... Encoder 21 ... Electromagnetic brake 22 ... Brake plate 23 ... Brake hub 24 ... Friction plate 25 ... Guide shaft 26 ... Movable plate 27 ... fixed frame 27a ... fixed surface 27b ... cylindrical space 28 ... electromagnet 29 ... brake spring 31 ... pulley 33 ... pulley hub 34 ... pulley body 34a ... pulley disk 34b ... pulley wheel 35 ... switching part 36 ... switching element 37 ... first Voltage application unit 38 ... Holding voltage generation unit (second voltage application unit) 39 ... First diode 40 ... Second diode 41 ... Third diode 42 ... Resistance (first resistance) 43 ... Capacitor 44 ... Time constant circuit 45 ... Switching 46: second resistor 47, 48: passive element 49 ... voltage selection Selection unit 50 ... Robot system 51 ... Robot 52 ... Control device 53 ... Base 54 ... Rotation base 54a ... Base rotation shaft 55 ... First arm (movable portion) 55a ... First swing shaft 56 ... Ar arm swing base 56a ... second rocking shaft 57 ... second arm (movable part) 57a ... second turning shaft 58 ... tip rocking base 58a ... tip rocking shaft 59 ... tip arm (moving part) 59a ... tip turning shaft 60 ... Motor unit 60A ... Oscillating unit 61 ... Oscillating motor (drive unit) 62 ... Oscillator pulley 63 ... Oscillating pulley 64 ... Oscillating base shaft 65 ... Oscillating belt 70 ... Motor unit 70A ... Rotating unit 71 ... times Rotating motor 72 (rotating body pulley) 73 ... rotating pulley 74 ... rotating transmission shaft 75 ... rotating belt 76a, 76b ... rotating transmission gear 79 ... tip arm Shaft 571 ... arm frame.

Claims (11)

It has a switching part that switches the voltage to the electromagnetic brake that brakes the movable part,
The switching unit includes a passive element,
A robot that switches a voltage applied to the electromagnetic brake from a first voltage to a second voltage lower than the first voltage based on a time constant of the passive element. The robot according to claim 1, wherein
The switching unit includes a switching element that is positioned between a first voltage applying unit that applies the first voltage and the electromagnetic brake and that is turned on / off based on a voltage level of the passive element. Robot. The robot according to claim 2, wherein
The said switching part has a 1st diode which flows an electric current in the direction of the said electromagnetic brake from the said switching element, The robot characterized by the above-mentioned. The robot according to claim 2 or 3,
The robot according to claim 1, wherein the switching element is a PMOS transistor. The robot according to any one of claims 1 to 3,
The switching unit includes a second voltage application unit that generates the second voltage. The robot according to claim 5, wherein
The switching unit includes a second diode that allows a current to flow from the second voltage application unit toward the electromagnetic brake. The robot according to claim 5, wherein
The robot, wherein the second voltage application unit transforms the first voltage into the second voltage. The robot according to any one of claims 2 to 6,
The switching unit includes a third diode that allows a current to flow from the passive element toward the first voltage application unit. In the robot according to any one of claims 1 to 7,
The passive device includes a resistor and a capacitor. The robot according to claim 9, wherein
Two or more said resistances are provided, The robot characterized by the above-mentioned. It has a switching part that switches the voltage to the electromagnetic brake that brakes the movable part,
The switching unit includes a passive element,
A control device that switches a voltage applied to the electromagnetic brake from a first voltage to a second voltage lower than the first voltage based on a time constant of the passive element.

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