Robot Hand

Abstract

A robot hand according to one aspect of the present disclosure can be equipped and used at the tip of various types of robot arms, such as a vertically articulated type, a horizontally articulated type, and a polar coordinate type. The robot hand has a base portion attached to the tip of the robot arm. A plurality of gripping portions are supported on the base portion. The plurality of gripping portions are fixed to the base portion. The center lines of the plurality of gripping portions are inclined in directions that move away from each other toward the front.

Description

[Technical Field]

[0001] The present disclosure relates to a robotic hand. [Background technology]

[0002] Some robot hands are equipped with multiple grippers suited to the characteristics of various workpieces to accommodate them (see, for example, Patent Document 1). Generally, these grippers are arranged side-by-side, fixed, or in an L-shape along two orthogonal axes, or attached to a tool changer. In any case, a robot hand with multiple grippers is inevitably larger than a robot hand equipped with a single gripper, raising concerns about interference with peripheral equipment. For example, in a robot hand with two types of grippers arranged side-by-side, when the robot hand's posture is changed so that one gripper can grasp a workpiece, the other gripper may interfere with the container containing the workpiece. In a robot hand with two types of grippers arranged in an L-shape, the rotation angle of the rotary joint closest to the robot hand may need to be physically or software-limited to prevent the robot hand itself from interfering with the robot. In a robot hand with a tool changer equipped with multiple types of grippers, the tool changer requires operation time to switch between the grippers, increasing the cycle time. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 7-285090 Summary of the Invention [Problem to be solved by the invention]

[0004] To provide a robot hand that can handle a variety of workpieces. [Means for solving the problem]

[0005] A robot hand according to an aspect of the present disclosure includes a base portion attached to a tip of a robot arm; Through the first support Supported 1st A gripping portion; a second gripping portion supported on the base portion via a second support base; and The first gripping portion and the second gripping portion The gripping part is ,So The centerlines of the two are inclined away from each other toward the front, The center line of the first gripping portion is outward from the center line of the base portion. Over 10 degrees to under 20 degrees The center line of the second gripping portion is parallel to the center line of the base portion. . [Brief explanation of the drawings]

[0006] [Figure 1] FIG. 1 is a diagram showing a robot arm mechanism equipped with a robot hand according to this embodiment. [Figure 2] FIG. 2 is a perspective view of the robot hand of FIG. [Figure 3] FIG. 3 is a front view of the robot hand of FIG. [Figure 4] FIG. 4 is a view showing the robot hand of FIG. 3 tilted. [Figure 5] FIG. 5 is a diagram for assisting in the explanation of the effects exerted by the robot hand according to this embodiment. [Figure 6] FIG. 6 is a diagram for assisting in the explanation of the effects exerted by the robot hand according to this embodiment. [Figure 7] FIG. 7 is a front view of a robot hand according to a first modified example of the present embodiment. [Figure 8] FIG. 8 is a front view of a robot hand according to a second modified example of the present embodiment. [Figure 9] FIG. 9 is a front view of a robot hand according to a third modified example of the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0007] A robot hand according to this embodiment (hereinafter simply referred to as a robot hand) will be described below with reference to the drawings. In the following description, components having substantially the same functions and configurations will be given the same reference numerals, and repeated description will be given only when necessary.

[0008] The configuration of the robot hand 1 will be described below with reference to FIGS. As shown in FIG. 1, the robot hand 1 is attached to the tip (wrist 91) of various types of robot arms 9, such as vertically articulated, horizontally articulated, and polar coordinate types, and is used. The robot hand 1 has multiple types of gripping units so that it can grip multiple types of workpieces. The multiple types of gripping units differ in at least one of the gripping method, gripping unit size, and gripping unit material. Gripping methods include methods that hold a workpiece by physically clamping it, and methods that hold a workpiece by suction. Examples of gripping units that hold a workpiece by physically clamping it include those with multiple fingers, such as two or three fingers, and those with wires that clamp the workpiece. Examples of gripping units that hold a workpiece by suction include those that use vacuum, suction, magnetic force, fluid, and static electricity.

[0009] In this embodiment, it is assumed that two types of workpieces 100, 200 stored in a container 300 are gripped by a robot hand 1. The first workpiece 100 has a smooth surface and is relatively heavy. The second workpiece 200 has an uneven surface and is relatively light. The robot hand 1 has a first suction pad 15 in the form of a rectangular plate with a single suction hole as a gripping part for gripping the first workpiece 100, and a second suction pad 16 in the form of a rectangular plate with multiple suction holes as a gripping part for gripping the second workpiece 200.

[0010] As shown in FIGS. 2 and 3 , the robot hand 1 has a rectangular base plate 10 as a base attached to the tip of the robot arm 9. A circular adapter plate 11 is provided on the surface of the base plate 10 as a connection part for connecting to the tip of the robot arm 9. A first suction pad 15 is supported on the back side of the base plate 10 via a first support base 13, and a second suction pad 16 is supported on the back side of the base plate 10 via a second support base 14. On the back side of the base plate 10, the two types of suction pads 15, 16 are arranged side by side along one axial direction. Typically, the two types of suction pads 15, 16 are arranged side by side at positions equidistant from the base plate 10. This means that the centers of the suction surfaces of the two types of suction pads 15, 16 are equidistant from the base plate 10. Of course, one of the two types of suction pads 15, 16 may be arranged so as to protrude forward.

[0011] 2 and 3, the three orthogonal axes of the hand coordinate system based on the robot hand 1 are defined as follows. For example, when defining the coordinate system using the base plate 10, the width direction of the base plate 10 is defined as the X-axis, the length (depth) direction of the base plate 10 is defined as the Y-axis, and the thickness direction of the base plate 10 is defined as the Z-axis. The Z-axis passes through the center point of the surface of the base plate 10 and is parallel to a line perpendicular to the base plate 10 (also referred to as the center line of the base plate 10). The Z-axis direction is also referred to as the front-to-rear direction of the robot hand 1. In the robot hand 1, the forward direction is the direction along the Z-axis, that is, the direction from the adapter plate 11 (base plate 10) connected to the robot arm 9 toward the suction pads 15 and 16. When the base unit is not plate-shaped, the three orthogonal axes are defined as the Z-axis, the axis perpendicular to the adapter plate 11 (the mounting surface of the robot arm), the X-axis, and the Y-axis, two axes perpendicular to the Z-axis. In this case, the center line of the base unit is a line parallel to the Z-axis and passing through the center point of the adapter plate 11. The center line of the suction pad, which will be described later, is a straight line that passes through the center point of the pad surface (suction surface) of the suction pad and is perpendicular to the pad surface.

[0012] As shown in FIG. 3 , in a front view, the first suction pad 15 is fixed to the base plate 10 via a first support base 13 so that its center line 15L is inclined outward at an inclination angle θ1 relative to the center line 10L of the base plate 10, and the second suction pad 16 is fixed to the base plate 10 via a second support base 14 so that its center line 16L is inclined outward at an inclination angle θ2 relative to the center line 10L of the base plate 10. Note that "the first suction pad 15 is inclined outward relative to the center line 10L of the base plate 10" means that, in a front view, the center line 15L of the first suction pad 15 is inclined in a direction away from the center line 10L of the base plate 10 toward the front. In this case, the pad surface of the first suction pad 15 faces outward. Note that when the robot hand 1 is viewed three-dimensionally rather than from the front, it can be described as follows: That is, the first suction pad 15 is fixed to the base plate 10 via the first support base 13 so that its center line 15L is inclined outward at an inclination angle θ1 with respect to the center plane of the base plate 10. The second suction pad 16 is fixed to the base plate 10 via the second support base 14 so that its center line 16L is inclined outward at an inclination angle θ2 with respect to the center plane of the base plate 10. The center plane of the base plate 10 is defined as a plane that is parallel to the YZ plane and includes the center line 10L of the base plate 10. That is, the suction pads 15, 16 are inclined only around the Y axis.

[0013] 3, for example, the first suction pad 15 and the second suction pad 16 are disposed at symmetrical positions with respect to the center line 10L of the base plate 10 (the center plane of the base plate 10) so that the inclination angle θ1 and the inclination angle θ2 are the same. In this case, it is desirable that the inclination angles θ1 and θ2 are each greater than 0 degrees and less than 45 degrees. The reason for this will be described later. Of course, the first suction pad 15 and the second suction pad 16 may also be disposed so that the inclination angle θ1 and the inclination angle θ2 are not the same.

[0014] The effects of the robot hand 1 according to this embodiment will be described below with reference to FIGS. 4 to 6. One feature of the robot hand 1 is that two types of gripping units (first suction pad 15 and second suction pad 16) are fixed to the base plate 10. This feature allows the gripping unit to be switched by simply moving the robot arm 9. The gripping unit to be used can be switched by simply changing the posture of the robot arm, without requiring a complex mechanism such as a tool changer equipped with multiple gripping units or a drive source such as a motor for driving the tool changer. Furthermore, as described below, the multiple gripping units are inclined outward with respect to the center line 10L of the base plate 10 so that their center lines intersect at a slight angle. This allows the gripping unit to be switched by a slight change in the posture of the robot arm 9, thereby reducing the time required to switch the gripping unit. Furthermore, because the robot hand 1 does not have a complex mechanism, the occurrence of breakdowns is reduced. Furthermore, because the robot hand 1 does not have a complex mechanism or drive source, its weight can be reduced compared to robot hands equipped with these.

[0015] Another feature of the robot hand 1 is that the first suction pad 15 and the second suction pad 16 are inclined such that their respective center lines 15L, 16L move away from each other toward the front. This feature allows the height H1 in the vertical direction defined by the first suction pad 15 and the second suction pad 16 when the robot hand 1 according to this embodiment is tilted, as shown in FIG. 4 , to be lower than the height H2 in the vertical direction defined by the first suction pad 15 and the second suction pad 16′ when the robot hand is tilted such that the respective center lines 15L, 16L of the first suction pad 15 and the second suction pad 16 are arranged parallel to the center line 10L of the base plate 10. This reduces the possibility of the second suction pad 16 interfering with the container 300 when the robot hand 1 is tilted to grip the first workpiece 100 with the first suction pad 15, as shown in FIG. 5 .

[0016] Furthermore, the inclination angles θ1 and θ2 of the center lines 15L and 16L of the first suction pad 15 and the second suction pad 16 relative to the center line 10L of the base plate 10 are greater than 0 degrees and less than 45 degrees. That is, the center lines 15L and 16L intersect at an angle greater than 0 degrees and less than 90 degrees. As a result, as shown in FIG. 6 , when the robot hand 1 mounted on the wrist 91 of the robot arm 9 is rotated together with the wrist 91, the range of movement of the wrist 91 can be narrowed so that the robot hand 1 and the workpiece held by the robot hand 1 do not interfere with the robot arm 9. In other words, the wider range of movement of the wrist 91 allows for more flexible changes in the posture of the robot hand 1. When the robot hand 1 is actually used, the inclination angles θ1 and θ2 of the first and second suction pads 15 and 16 are designed to be greater than 5 degrees and less than 10 degrees, typically 7.5 degrees, taking into account the inclination angle of the workpiece in the container 300, etc. In other words, the first and second suction pads 15, 16 are designed so that the intersecting angle between their respective center lines 15L, 16L is in the range of more than 10 degrees and less than 20 degrees, typically 15 degrees.

[0017] The feature described in this embodiment that the center lines 15L, 16L of the first suction pad 15 and the second suction pad 16 are inclined in directions that move away from each other toward the front defines only the positional relationship between the first suction pad 15 and the second suction pad 16. Therefore, in the robot hand 1, both the first suction pad 15 and the second suction pad 16 do not need to be inclined outward with respect to the center line 10L of the base plate 10.

[0018] A robot hand 2 according to a first modified example of this embodiment will be described below with reference to Fig. 7. As shown in Fig. 7, the first suction pad 15 may be fixed to the base plate 10 via a first support base 23 so that its center line 15L is inclined outward at an inclination angle θ3 with respect to the center line 10L of the base plate 10, and the second suction pad 16 may be fixed to the base plate 10 via a second support base 24 so that its center line 16L is parallel to the center line 10L of the base plate 10. The robot hand 2 according to the first modified example configured in this manner also achieves the same effects as this embodiment.

[0019] 3, in the robot hand 1 according to this embodiment, the first support base 13 is inclined outward together with the first suction pad 15 at an inclination angle θ1, and the second support base 14 is inclined outward together with the second suction pad 16 at an inclination angle θ2. However, as long as the first and second suction pads 15 and 16 can be arranged in the positional relationship shown in FIG. 3, the shapes of the first and second support bases 13 and 14 are not limited to those of this embodiment.

[0020] A robot hand 3 according to a second modified example of this embodiment will be described below with reference to FIG. 8 . As in the robot hand 3 shown in FIG. 8 , only the first suction pad 15 may have its center line 15L inclined outward at an inclination angle θ1 with respect to the center line 10L of the base plate 10, and the first support base 33 supporting the first suction pad 15 on the base plate 10 may be disposed so that its center line 33L is parallel to the center line 10L of the base plate 10. In this case, the first support base 33 only needs to have a fixing surface to which the first suction pad 15 is fixed inclined outward at an inclination angle θ1 with respect to the horizontal plane. Similarly, the second support base 34 only needs to have a center line 34L inclined parallel to the center line of the base plate 10, and a fixing surface to which the second suction pad 16 is fixed inclined outward at an inclination angle θ2 with respect to the horizontal plane. The robot hand 3 according to the second modified example configured in this manner also achieves the same effects as this embodiment.

[0021] The robot hand 1 according to this embodiment has two types of gripping parts: the first suction pad 15 having a single suction hole and the second suction pad 16 having multiple suction holes. However, the gripping parts are not limited to suction pads. Hereinafter, a robot hand 4 according to a third modified example of this embodiment will be described with reference to Fig. 9. As shown in Fig. 9, the robot hand 4 has a plurality of, here, two types of gripping parts, namely, suction pads 15 and grippers. 46. ​​The suction pad 15 is supported on the base plate 10 via the first support base 13 so that its center line 15L is inclined outward at an inclination angle θ4 with respect to the center line 10L of the base plate 10. The gripper 46 has a chuck mechanism 461 and a pair of fingers 462, 463 connected to a pair of movable parts of the chuck mechanism 461. The gripper 46 is supported on the base plate 10 via the second support base 44 so that its center line 46L is inclined outward at an inclination angle θ5 with respect to the center line 10L of the base plate 10. Note that the center line 46L of the gripper 46 can be defined as an axis of symmetry when the pair of fingers 462, 463 operate symmetrically. Alternatively, the center line 46L of the gripper 46 may be defined as a straight line that is perpendicular to the support surface of the second support base 44 to which the chuck mechanism 461 is attached and that passes through the gripping center position 46C of the gripper 46. The robot hand 4 according to the third modified example configured in this manner also achieves the same effects as the present embodiment.

[0022] The robot hand according to this embodiment and its modified examples has two types of grippers. However, the robot hand may have three or more types of grippers. For example, when the robot hand has three types of grippers, the three types of grippers are fixedly arranged side by side, and the two types of grippers arranged at both ends are fixed to the base plate 10 so that their center lines are inclined outward with respect to the center line 10L of the base plate 10, and the gripper arranged in the center is fixed to the base plate 10 so that its center line is parallel to the center line 10L of the base plate 10. Of course, the three types of grippers may also be arranged radially at equal intervals and fixed to the base plate 10 so that their center lines are inclined outward with respect to the center line 10L of the base plate 10.

[0023] The following additional notes are further disclosed regarding this embodiment and the modified examples. (Appendix 1) The robot hand 1 has a base portion 10 attached to the tip of the robot arm 9 and a plurality of gripping portions 15, 16 supported by the base portion 10, and the gripping portions 15, 16 are fixed to the base portion 10 and their center lines are inclined in directions that move away from each other toward the front. (Appendix 2) In the robot hand 1 described in Supplementary Note 1, the center lines of the gripping parts 15 and 16 are fixed to the base part 10 so as to intersect at an angle greater than 0 degrees and less than 90 degrees. (Appendix 3) In the robot hand 1 described in Supplementary Note 1, there are two gripping parts 15 and 16, which are arranged symmetrically with respect to the center line of the base part 10. (Appendix 4) In the robot hand 1 described in Supplementary Note 1, there are two gripping parts 15, 16, and the center lines of the gripping parts 15, 16 are inclined outward with respect to the center line of the base part 10 at an angle of more than 0 degrees and less than 45 degrees. (Appendix 5) In the robot hand 1 described in Appendix 1, there are two gripping portions 15, 16, one of which has its center line inclined outward from the center line of the base portion 10 at an angle of more than 0 degrees and less than 45 degrees, and the other of the gripping portions 15, 16 has its center line parallel to the center line of the base portion 10. (Appendix 6) In the robot hand 1 described in Supplementary Note 4, the inclination angle of the center line of one of the gripping portions 15, 16 relative to the center line of the base portion 10 is the same as the inclination angle of the center line of the other of the gripping portions 15, 16 relative to the center line of the base portion 10. (Appendix 7) In the robot hand 1 described in Supplementary Note 4, the inclination angle of the center line of one of the grippers 15, 16 relative to the center line of the base 10 is different from the inclination angle of the center line of the other of the grippers 15, 16 relative to the center line of the base 10.

[0024] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, as well as within the scope of the invention described in the claims and their equivalents. [Explanation of symbols]

[0025] 1...robot hand, 9...robot arm, 91...wrist portion, 10...base plate, 11...adapter plate, 13, 14...support base, 15, 16...suction pads

Claims

1. a base part attached to the tip of the robot arm; a first gripping portion supported on the base portion via a first support base; a second gripping portion supported on the base portion via a second support base; the first gripping portion and the second gripping portion are inclined such that their respective center lines move away from each other toward the front, The center line of the first grip portion is inclined outward with respect to the center line of the base portion at an angle of more than 10 degrees and less than 20 degrees, A robot hand, wherein a center line of the second gripping portion is parallel to a center line of the base portion.

2. A robot hand as described in claim 1, wherein the center line of the first gripping portion and the center line of the second gripping portion intersect at 15 degrees.

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