JP2013082067A - Industrial robot - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an industrial robot capable of increasing operation speed.SOLUTION: A first joint shaft 2 is formed of a hollow ball screw spline shaft 12, a first arm driving motor 8 and a second working shaft driving motor 11 are mounted to a fixed bracket 41 in a base 1, and a second arm driving motor 9 and a first working shaft driving motor 10 are mounted to a movable bracket 42 in the base 1. In addition, a first pulley shaft 27 for transmitting the rotary torque of the second arm driving motor 9 to a second joint shaft 4 and a second pulley shaft 34 for transmitting the rotary torque of the first working shaft driving motor 10 to a working shaft 6 are coaxially provided inside the ball screw spline shaft 12.

Description

  The present invention relates to an industrial robot, and more particularly to an industrial robot called an industrial robot or a SCARA robot.

  In general, the performance required for this type of industrial robot includes high operating speed, small size, low inertia, and high maintainability. However, as disclosed in Patent Document 1, the conventional industrial robot has a drawback that the operation speed is slow because an actuator such as a motor is mounted on the horizontal arm. Therefore, in order to increase the operation speed and the like, there is known one in which actuators such as a motor are concentrated on the base side (see, for example, Patent Documents 2 and 3).

JP 2003-285284 A JP 2007-44839 A JP 2003-25262 A

However, since the ball screw is provided at the distal end portion of the second arm, the one disclosed in Patent Document 2 has a structure in which the distal end portion of the second arm is wide in the vertical direction and takes a width in the vertical direction. As a result, the robot arm becomes heavier and the operation speed is difficult to increase. Another problem is that if a large motor is used to increase the operating speed, the motor becomes large.
On the other hand, what is disclosed in Patent Document 3 does not have a structure in which the tip of the second arm is wide in the vertical direction as disclosed in Patent Document 2, but the lifting cover of the lifting frame is a ball screw. Because of this, there is a problem that the stroke of the lifting frame cannot be easily changed.
The present invention has been made in view of the above-described problems, and an object of the present invention is to provide an industrial robot capable of increasing the operation speed.

  In order to solve the above problems, an aspect of the industrial robot according to the present invention includes a base, a first horizontal arm rotatably supported on the base via a first joint shaft, and the first A second horizontal arm rotatably connected to the first horizontal arm via a second joint axis parallel to the one joint axis; and provided on the second horizontal arm in parallel with the second joint axis. A first working arm, a first arm driving motor for driving the first horizontal arm about the axis of the first joint axis, and a second horizontal arm for driving the axis of the second joint axis A second arm driving motor, a first working shaft driving motor for driving the working shaft around an axis, and a second working shaft driving motor for driving the working shaft in an axial direction. Industrial robot, wherein the first joint axis is a hollow ball screw spline shaft The first arm driving motor and the second work shaft driving motor are mounted on a fixed bracket provided inside the base, and the second arm driving motor and The first working shaft driving motor is mounted on a movable bracket provided in the base so as to be movable up and down, and the rotational torque generated by the second arm driving motor is transmitted to the second joint shaft. A first pulley shaft for driving and a second pulley shaft for transmitting rotational torque generated by the first working shaft driving motor to the working shaft are arranged coaxially inside the ball screw spline shaft. It is characterized by that.

According to such a configuration, the second arm driving motor is arranged at the connecting portion between the first horizontal arm and the second horizontal arm, or the first working shaft is driven on the distal end side of the second horizontal arm. Therefore, it is possible to reduce the weight of the movable part and increase the operation speed.
In addition, since it becomes possible to use small motors as the first arm driving motor, the second arm driving motor, the first working shaft driving motor, and the second working shaft driving motor, these Even if this motor is arranged inside the base, the increase in size of the base can be suppressed.

In addition, since the first joint shaft is formed of a hollow ball screw spline shaft, it is not necessary to arrange the ball screw spline on the tip side of the second horizontal arm, and the tip portion of the second horizontal arm is wide in the vertical direction. Therefore, the weight of the second horizontal arm can be reduced.
In another aspect of the industrial robot according to the present invention, the work shaft and the first pulley shaft are formed hollow, and the length of the first horizontal arm and the length of the second horizontal arm are It is characterized by having the same length.

According to such a configuration, the first horizontal arm and the second horizontal arm are calibrated by aligning the axis of the work shaft and the axis of the ball screw spline shaft using a rod-shaped calibration jig. Can be easily performed.
In addition, the second joint axis and the work axis can be selectively arranged, so that the required structural rigidity can be obtained by arranging the second joint axis outside the work axis. Applicable to applications that require deceleration.

It is a perspective view of the industrial robot which concerns on one Embodiment of this invention. It is a top view of the industrial robot shown in FIG. It is a side view of the industrial robot shown in FIG. It is a rear view of the industrial robot shown in FIG. It is a figure which shows the AA cross section of FIG. It is a figure for demonstrating one of the effects of the industrial robot shown in FIG.

Hereinafter, an industrial robot according to the present invention will be described with reference to the drawings.
1 is a perspective view of an industrial robot according to an embodiment of the present invention, FIG. 2 is a plan view thereof, FIG. 3 is a side view thereof, and FIG. 4 is a rear view thereof. 5 is a cross-sectional view taken along the line AA of FIG. 2. The industrial robot according to the embodiment of the present invention includes a base 1, a first horizontal arm 3, a second horizontal arm 5, and a first horizontal arm. Arm driving motor 8, second arm driving motor 9, first working shaft driving motor 10, and second working shaft driving motor 11.
The base 1 is fixed to a horizontal surface such as a floor surface or a ceiling surface, and includes a bottom plate 1a, columns 1b to 1e erected upward from four corners of the bottom plate 1a, and these columns 1b to 1e. And a top plate 1f supported above the bottom plate 1a.
The first horizontal arm 3 is rotatably supported on the base 1 via a first joint shaft 2 perpendicular to a horizontal plane to which the base 1 is fixed. Further, the first horizontal arm 3 has a second joint shaft 4 parallel to the first joint shaft 2 at the tip.

The second joint shaft 4 is formed in a hollow shape, and the second horizontal arm 5 is rotatably connected to the distal end portion of the first horizontal arm 3 through the second joint shaft 4.
The second horizontal arm 5 has a work shaft 6 parallel to the second joint shaft 4 at the tip. The work shaft 6 is formed to be hollow like the second joint shaft 4, and an end effector (not shown) such as a hand device is attached to the work shaft 6.
The first arm driving motor 8 drives the first horizontal arm 3 around the axis of the first joint shaft 2, and is fixed to the columns 1 b and 1 c of the base 1 and the base plate 1 a and the top plate. It is attached to a fixed bracket 41 provided between the plate 1f.
The second arm driving motor 9 drives the second horizontal arm 5 about the axis of the second joint shaft 4 and can move up and down between the bottom plate 1a of the base 1 and the fixed bracket 41. The movable bracket 42 is provided.

The first work shaft drive motor 10 drives the end effector 7 about the work shaft 6, and is mounted on the movable bracket 42 in the same manner as the second arm drive motor 9.
The second work shaft drive motor 11 drives the end effector 7 in the axial direction (vertical direction) of the work shaft 6, and is mounted on the fixed bracket 41 in the same manner as the first arm drive motor 8. ing.

  The first joint shaft 2 is formed from a hollow ball screw spline shaft 12. The rotational torque generated by the first arm driving motor 8 is applied to the ball screw spline shaft 12 by the timing pulley 13, the timing belt 14, the timing pulleys 15 and 16, the timing belt 17, the timing pulley 18, and the ball screw nut 19. Rotational torque generated by the second work shaft drive motor 11 is transmitted via the timing pulley 20, the timing belt 21, the timing pulley 22 and the spline nut 23.

The ball screw nut 19 is fixed to the top plate 1 f of the base 1, and when the rotational torque generated by the first arm driving motor 8 is transmitted to the ball screw spline shaft 12 via the ball screw nut 19, the ball screw The spline shaft 12 rotates around the axis, whereby the first horizontal arm 3 rotates about the first joint shaft 2.
The spline nut 23 is fixed to a fixed bracket 41. When the rotational torque generated by the second work shaft drive motor 11 is transmitted to the ball screw spline shaft 12 via the spline nut 23, the ball screw spline shaft 12 is pivoted. Accordingly, the first horizontal arm 3, the second joint shaft 4, the second horizontal arm 5 and the work shaft 6 are moved up and down.

A first pulley shaft 27 and a second pulley shaft 34 are provided coaxially inside the ball screw spline shaft 12. The pulley shafts 27 and 34 are formed hollow, and the second pulley shaft 34 is disposed inside the first pulley shaft 27.
The first pulley shaft 27 has timing pulleys 26 and 28 at its lower end and upper end. Among these timing pulleys 26, 28, the timing pulley 26 provided at the lower end portion of the first pulley shaft 27 receives rotational torque generated by the second arm driving motor 9, causing the timing pulley 24 and the timing belt 25 to move. It comes to be transmitted through. Then, the rotational torque transmitted to the timing pulley 26 is transmitted to the second joint shaft 4 via the first pulley shaft 27, the timing pulley 28, the timing belt 29, and the timing pulley 30, thereby causing the second horizontal arm 5 to move. A turning operation is performed around the second joint shaft 4.

  The second pulley shaft 34 has timing pulleys 33 and 35 at its lower end and upper end. Among these timing pulleys 33, 35, the timing pulley 33 provided at the lower end portion of the second pulley shaft 34 receives rotational torque generated by the first work shaft drive motor 10 as a timing pulley 31, a timing belt 32. It comes to be transmitted through. The rotational torque transmitted to the timing pulley 33 is transmitted to the work shaft 6 via the second pulley shaft 34, the timing pulley 35, the timing belt 36, the timing pulley 37, the timing belt 38, and the timing pulley 39. The shaft 6 rotates around the axis.

The length of the second horizontal arm 5 (the linear distance L1 from the center of the second joint shaft 4 to the center of the work shaft 6) is the length of the first horizontal arm 3 (the center of the ball screw spline shaft 12). It has the same length as the linear distance L2) to the center of the two joint shafts 4.
In the embodiment of the present invention described above, the following operational effects can be obtained.
(1) The first arm driving motor 8, the second arm driving motor 9, the first work shaft driving motor 10, and the second work shaft driving motor 11 are arranged on the base 1 side. Therefore, the total weight of the movable part becomes light, and it is not necessary to use a large motor as the second arm driving motor 9, the first work shaft driving motor 10, and the second work shaft driving motor 11. Miniaturization can be achieved.

(2) Since the inertia of the first horizontal arm 3 and the second horizontal arm 5 is reduced by reducing the total weight of the movable part, the operation speed can be increased.
(3) A small motor can be used as the second arm drive motor 9, the first work shaft drive motor 10, and the second work shaft drive motor 11 by reducing the total weight of the movable part. Thereby, size reduction of the base 1 can be achieved.
(4) The first arm driving motor 8, the second arm driving motor 9, the first working shaft driving motor 10 and the second working shaft driving motor 11 are arranged on the base 1 side. Thus, it is not necessary to wire an electric wire or a signal line for supplying electric power to the first work axis drive motor 10 or the second work axis drive motor 11 to the tip side of the second horizontal arm 5, and Since wiring can be performed collectively on one side, maintenance can be improved.

(5) By making the length of the 1st horizontal arm 3 and the length of the 2nd horizontal arm 5 into the same length, the 2nd joint axis | shaft 4 and the working axis | shaft 6 can be selectively arrange | positioned. Since the required structural rigidity can be obtained by disposing the second joint shaft 4 outside the work shaft 6, it is possible to cope with applications requiring acceleration / deceleration.
(6) By arranging the ball screw spline shaft 12 on the base 1 side, the structure of power transmission by the belt can be simplified as compared with the conventional example, thereby reducing the weight of the tip of the second horizontal arm 5. be able to.
(7) Since the ball screw spline shaft 12, the first pulley shaft 27, and the second pulley shaft 34 need only be supported on one surface, the stroke of the ball screw spline shaft 12 can be easily changed.

(8) By making the linear distance L1 from the center of the second joint axis 4 to the center of the work axis 6 the same as the linear distance L2 from the center of the first joint axis 2 to the center of the second joint axis 4, As shown in FIG. 6, the first horizontal arm 3 and the second horizontal arm 5 are obtained by aligning the axis of the work shaft 6 and the axis of the pulley shaft 34 using a rod-shaped calibration jig 43. Can be easily calibrated.
(9) Electric wires and signal lines for supplying electric power to the second arm driving motor 9, the first work axis driving motor 10, and the second work axis driving motor 11 are connected to the first horizontal arm 3 and the second Therefore, the first horizontal arm 3 and the second horizontal arm 5 can be swung within a range of 360 °.
In the above-described embodiment of the present invention, the second pulley shaft 34 is formed from a hollow shaft. However, the second pulley shaft 34 may be formed from a solid shaft.

  DESCRIPTION OF SYMBOLS 1 ... Base, 2 ... 1st joint axis, 3 ... 1st horizontal arm, 4 ... 2nd joint axis, 5 ... 2nd horizontal arm, 6 ... Work axis, 8 ... 1st arm drive motor, DESCRIPTION OF SYMBOLS 9 ... Second arm drive motor, 10 ... First work shaft drive motor, 11 ... Second work shaft drive motor, 12 ... Ball screw spline shaft, 13 ... Timing pulley, 14 ... Timing belt, 15 ... timing pulley, 16 ... timing pulley, 17 ... timing belt, 18 ... timing pulley, 19 ... ball screw nut, 20 ... timing pulley, 21 ... timing belt, 22 ... timing pulley, 23 ... spline nut, 24 ... timing pulley, 25 ... Timing belt, 26 ... Timing pulley, 27 ... First pulley shaft, 28 ... Timing pulley, 29 ... Timing belt, 3 ... timing pulley, 31 ... timing pulley, 32 ... timing belt, 33 ... timing pulley, 34 ... second pulley shaft, 35 ... timing pulley, 36 ... timing belt, 37 ... timing pulley, 38 ... timing belt, 39 ... pulley , 41 ... fixed bracket, 42 ... movable bracket, 43 ... calibration jig.

Claims (2)

A base, a first horizontal arm rotatably supported on the base via a first joint axis, and the first horizontal arm via a second joint axis parallel to the first joint axis A second horizontal arm pivotably coupled to the second horizontal arm, a work axis provided parallel to the second joint axis on the second horizontal arm, and the first horizontal arm connected to the first joint axis. A first arm driving motor for driving about the axis, a second arm driving motor for driving the second horizontal arm about the axis of the second joint axis, and the working axis for driving the axis. An industrial robot comprising a first work axis drive motor and a second work axis drive motor for driving the work axis in the axial direction,
The first joint shaft is formed of a hollow ball screw spline shaft, and the first arm driving motor and the second work shaft driving motor are attached to a fixed bracket provided in the base. And the second arm driving motor and the first work shaft driving motor are mounted on a movable bracket provided in the base so as to be movable up and down, and the second arm driving motor. A first pulley shaft for transmitting the rotational torque generated by the first joint shaft to the second joint shaft and a second pulley shaft for transmitting the rotational torque generated by the first work shaft drive motor to the work shaft. An industrial robot characterized by being coaxially arranged inside a ball screw spline shaft.   The working shaft and the first pulley shaft are formed hollow, and the length of the first horizontal arm and the length of the second horizontal arm are the same length. The industrial robot according to 1.

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