Hand device and actuator

Abstract

This hand device (10) is provided with a rod-shaped hand body (11) that picks up an object at a tip part (10a). The hand body (11) is provided with: a fixing part (20) in which a first groove part (21) through which the object passes is formed in a radial direction that intersects a central axis (O) of the hand body (11) in the tip part (10a); a holding part (30) that is provided so as to be capable of rotating around the central axis (O) with respect to the fixing part (20) and sandwiches the object with the fixing part (20) by displacement with respect to the first groove part (21); and a cutting part (40) that is provided so as to be capable of rotating around the central axis (O) with respect to the fixing part (20) and the holding part (30) and cuts the object.

Description

Hand device and actuator

[0001] The present invention relates to a hand device and an actuator. This application claims priority to Japanese Patent Application No. 2024-090203 filed on June 3, 2024, and Japanese Patent Application No. 2025-088458 filed on May 28, 2025, the contents of which are incorporated herein by reference.

[0002] Patent Document 1 below discloses a fruit harvesting hand for harvesting fruits such as strawberries, mandarin oranges, tomatoes, cucumbers, and eggplants. This fruit harvesting hand has a stem-holding chuck, a first blade, and a second blade. The stem-holding chuck clamps and holds the stem of the fruit to be harvested in a stem-holding portion. The first blade cuts the stem at a position above the stem-holding chuck while the stem is held in the stem-holding portion. The second blade is located below the stem-holding chuck and descends along the stem due to gravity, stopping when it abuts against the stem of the fruit, and then cuts the stem.

[0003] Patent No. 6991611

[0004] However, if the fruit stalks are too long, they may damage other fruit in the harvesting box. Therefore, the above-mentioned fruit harvesting hand has cutting blades on the top and bottom of the stem holding chuck, which cut the fruit stalks in two stages, one above the other, to shorten the fruit stalks. However, providing cutting blades on the top and bottom of the stem holding chuck increases the vertical dimension of the fruit harvesting hand, which can cause collisions with other fruit, stems, leaves, etc., and potentially injure them when picking fruit.

[0005] The present invention provides a hand device and an actuator that can pick up a target object without damaging other objects.

[0006] A first aspect of the present invention provides a hand device comprising a rod-shaped hand body for picking up an object at its tip, the hand body comprising: a fixed portion at its tip end having a first groove formed therein in a radial direction intersecting the central axis of the hand body, through which the object passes; a holding portion rotatably arranged about the central axis relative to the fixed portion and configured to clamp the object between itself and the fixed portion by displacement relative to the first groove; and a cutting portion rotatably arranged about the central axis relative to the fixed portion and the holding portion, for cutting the object.

[0007] Moreover, the actuator of a second aspect of the present invention includes the hand device, a first drive unit that rotates the holding portion of the hand device, and a second drive unit that rotates the cutting portion of the hand device.

[0008] According to the hand device and actuator described above, the rod-shaped hand body can pick up a target object without damaging other objects.

[0009] 13A and 13B are perspective views of a fruit harvesting device according to a first embodiment; a perspective view of an actuator according to the first embodiment; an internal configuration diagram of an actuator according to the first embodiment; a perspective view of a tip of a hand body according to the first embodiment; a front view of the tip of a hand body according to the first embodiment; an operation flow diagram of a first picking mode according to the first embodiment; a front view showing the operation of the hand device in the first picking mode according to the first embodiment; a front view showing the operation of the hand device in the first picking mode according to the first embodiment; an operation flow diagram of a second picking mode according to the first embodiment; a front view showing the operation of the hand device in the second picking mode according to the first embodiment; a perspective view of a tip of a hand body according to a first modified example; a side view of a cutting unit according to a second modified example; an internal configuration diagram of an actuator according to a second embodiment; a perspective view of area A shown in FIG. 13A; a perspective view of a tip of a hand body according to the second embodiment; a front view showing the operation of the hand device according to the second embodiment; a front view showing the operation of the hand device according to the third embodiment; a front view showing the operation of the hand device according to the fourth embodiment.

[0010] Hereinafter, each embodiment of the present invention will be described with reference to the drawings. Note that in the following description, an example will be described in which a hand device and an actuator according to each embodiment of the present invention are applied to a fruit harvesting device, but the object to be picked is not limited to fruit, and may be other organic matter (such as vegetables, seaweed, other plants, etc.) or inorganic matter (such as metal).

[0011] First Embodiment Fig. 1 is a perspective view of a fruit harvesting device 1 according to a first embodiment. As shown in Fig. 1, the fruit harvesting device 1 includes a travellable carriage 2, a robot arm 3 mounted on the carriage 2, and an actuator 4 attached to the tip of the robot arm 3.

[0012] The cart 2 has multiple wheels 2a and moves autonomously based on a preset program. A harvest box 5 for placing harvested fruit 101 is attached to the cart 2. The robot arm 3 is, for example, an articulated robot arm, and controls the position and orientation of an actuator 4 based on a preset program.

[0013] The actuator 4 includes a hand device 10 that picks an object 100. The object 100 shown in Fig. 1 includes a plurality of fruits 101 and a plurality of fruit stalks 102 that support the plurality of fruits 101. In the object 100 shown in Fig. 1, the plurality of fruits 101 are closely packed together.

[0014] Fig. 2 is a perspective view of the actuator 4 according to the first embodiment. Fig. 3 is a diagram showing the internal configuration of the actuator 4 according to the first embodiment. As shown in these figures, the actuator 4 includes a hand device 10 that picks up an object 100 with a tip portion 10a, and a first drive unit 60 and a second drive unit 70 that drive the hand device 10.

[0015] The hand device 10 includes a rod-shaped hand body 11 and a housing 12 that supports the hand body 11. The actuator 4 includes a waterproof cover 4A that covers the housing 12, the first drive unit 60, and the second drive unit 70. The hand body 11 is provided to protrude from the waterproof cover 4A.

[0016] In the following description, an XYZ Cartesian coordinate system is set, and the positional relationships of the various components are sometimes described with reference to this XYZ Cartesian coordinate system. The X-axis direction is the axial direction along which the central axis O of the rod-shaped hand main body 11 extends. The X-axis direction is also referred to as the front-to-rear direction of the hand device 10 and the actuator 4.

[0017] The Y-axis direction is a first radial direction perpendicular to the axial direction. The Y-axis direction is also referred to as the left-right or horizontal direction of the hand device 10 and the actuator 4. The Z-axis direction is a second radial direction perpendicular to the axial direction and the first radial direction. The Z-axis direction is also referred to as the up-down or vertical direction of the hand device 10 and the actuator 4.

[0018] 3, the hand body 11 includes a fixed part 20 fixed to the housing 12, a holding part 30 rotatable about a central axis O relative to the fixed part 20, and a cutting part 40 rotatable about the central axis O relative to the fixed part 20 and the holding part 30. The fixed part 20, the holding part 30, and the cutting part 40 are arranged concentrically with the central axis O as a common axis.

[0019] The fixed portion 20 is formed in a cylindrical shape extending in the X-axis direction. A first groove 21, through which the target object 100 passes in the Z-axis direction, is formed at the end on the +X side of the fixed portion 20. As shown in FIG. 2, the first groove 21 is formed in a substantially U-shape in plan view. The end on the -X side of the fixed portion 20 is inserted into the housing 12 and fixed to the housing 12 by a fixing member 15 such as a setscrew.

[0020] As shown in FIG. 3 , the retaining portion 30 is formed in a cylindrical shape extending in the X-axis direction and is disposed radially inward of the fixed portion 20. A second groove portion 31 that can face the first groove portion 21 in the radial direction is formed at the +X side end of the retaining portion 30. As shown in FIG. 2 , the second groove portion 31 is formed in a substantially U-shape in plan view. The −X side end of the retaining portion 30 is inserted into the housing 12 and extends further rearward than the −X side end of the fixed portion 20, as shown in FIG. 3 . This −X side end of the retaining portion 30 is journaled by a pair of first bearings 13 provided in the housing 12.

[0021] The cutting portion 40 is detachably provided at the +X side end of a cylindrical support tube portion 41 that extends in the X-axis direction. The cutting portion 40 and the support tube portion 41 are arranged radially inside the holding portion 30. The -X side end of the support tube portion 41 is inserted into the housing 12 and extends further rearward than the -X side end of the holding portion 30. The -X side end of the support tube portion 41 is journaled by a pair of second bearings 14 provided in the housing 12.

[0022] The first drive unit 60 includes a first motor 61 and a first power transmission mechanism 62 that transmits the torque of the first motor 61 to the holder 30. The first motor 61 is, for example, a servo motor, and is attached to a first motor attachment portion 16 provided on the upper part of the housing 12. The first power transmission mechanism 62 includes a drive pulley 63, a timing belt 64, and a driven pulley 65.

[0023] The drive pulley 63 is attached to the output shaft of the first motor 61. The driven pulley 65 is attached to the outer periphery of the holding part 30 between the pair of first bearings 13. The driven pulley 65 is fixed to the holding part 30 by a fixing member 66 such as a setscrew. The timing belt 64 is stretched between the drive pulley 63 and the driven pulley 65.

[0024] According to the first drive unit 60 configured as described above, when the output shaft of the first motor 61 rotates, the torque of the first motor 61 is transmitted to the holder 30 via the first power transmission mechanism 62, causing the holder 30 to rotate around the central axis O. This allows the object 100 to be held at the tip 10 a of the hand body 11.

[0025] The second drive unit 70 includes a second motor 71 and a second power transmission mechanism 72 that transmits the torque of the second motor 71 to the cutting unit 40 via the support cylinder 41. The second motor 71 is, for example, a servo motor, and is attached to a second motor attachment portion 17 provided at the bottom of the housing 12. The second power transmission mechanism 72 includes a drive pulley 73, a timing belt 74, and a driven pulley 75.

[0026] The drive pulley 73 is attached to the output shaft of the second motor 71. The driven pulley 75 is attached to the outer periphery of the support cylinder portion 41 between the pair of second bearings 14. The driven pulley 75 is fixed to the support cylinder portion 41 by a fixing member 76 such as a setscrew. The timing belt 74 is stretched between the drive pulley 73 and the driven pulley 75.

[0027] According to the second drive unit 70 configured as described above, when the output shaft of the second motor 71 rotates, the torque of the second motor 71 is transmitted to the support cylinder 41 via the second power transmission mechanism 72, and the cutting unit 40 rotates around the central axis O via the support cylinder 41. This makes it possible to cut the object 100 held at the tip 10a of the hand body 11.

[0028] Fig. 4 is a perspective view of the tip 10a of the hand body 11 according to the first embodiment. Fig. 5 is a front view of the tip 10a of the hand body 11 according to the first embodiment. As shown in these figures, the hand body 11 is provided with a detection unit 50 that detects the target object 100 on the central axis O.

[0029] As shown in FIG. 5 , the cutting unit 40 includes a cylindrical base 42 extending in the X-axis direction and an arc-shaped cutting blade 43 protruding from the base 42 toward the +X side. A through-hole 42a in which a detection unit 50 is disposed is formed in the center of the base 42. The detection unit 50 is, for example, an imaging camera disposed on the central axis O. The cutting blade 43 rotates around the central axis O to cut the target object 100, so only one cutting blade is required. This allows the dimensions of the tip 10a of the hand body 11 to be smaller than those of conventional scissors equipped with two cutting blades. Note that multiple cutting blades 43 may be provided.

[0030] 3, the detection unit 50 is provided in a sensor tube portion 51 that is disposed radially inside the support tube portion 41. The -X side end of the sensor tube portion 51 extends rearward beyond the -X side end of the support tube portion 41 and protrudes rearward from the housing 12. A cable connected to the detection unit 50 passes through the sensor tube portion 51 and can be connected to a power supply device or an external device (not shown).

[0031] The detection unit 50 is not limited to an imaging camera, and may be a contact-type touch sensor or a non-contact-type photoelectric sensor, etc. Furthermore, instead of or together with the detection unit 50, an auxiliary device may be provided that sucks air to attract the target object 100 or sprays air to blow away the cut fruit stalk 102. In this case, the detection unit 50 (e.g., an imaging camera) may be attached to the outside of the fixed unit 20.

[0032] 5, the first groove 21 formed in the fixed portion 20 has first wall surfaces 21a and 21b extending parallel to each other in the vertical direction (radial direction). The first wall surface 21a is formed on the -Z side of the central axis O at the open end of the fixed portion 20. The first wall surfaces 21a are provided in pairs facing each other in the Y-axis direction and are spaced apart by a width W1 in the Y-axis direction.

[0033] A first wall surface 21b is formed on the +Z side of the central axis O at the open end of the fixing portion 20. The first wall surfaces 21b are provided in pairs facing each other in the Y-axis direction and are spaced apart by a width W2 in the Y-axis direction. The width W2 of the first wall surface 21b is larger than the width W1 of the first wall surface 21a. Because the width W2 is larger than the width W1, it becomes easier to pass the fruit stalk 102 through the first groove portion 21, for example, even if the fruit stalk 102 extending upward from the fruit 101 is curved.

[0034] The second groove 31 formed in the holding portion 30 has second wall surfaces 31a, 31b extending radially from the central axis O when viewed axially of the central axis O. The second wall surface 31a is formed on the -Z side of the central axis O at the open end of the holding portion 30. The second wall surfaces 31a are provided in pairs so as to open at an angle θ1 with respect to the central axis O. The inner and outer diameter side ends (corners) of the second wall surfaces 31a, 31b are chamfered so as not to damage the object 100.

[0035] A second wall surface 31b is formed on the +Z side of the central axis O at the open end of the holding portion 30. The second wall surfaces 31b are provided in pairs so as to open at an angle θ2 with respect to the central axis O. The angle θ2 of the second wall surfaces 31b is larger than the angle θ1 of the second wall surface 31a. Because the angle θ2 is larger than the angle θ1, for example, even if the fruit stalk 102 extending upward from the fruit 101 is curved, the fruit stalk 102 can be easily passed through the second groove portion 31.

[0036] 3 , the actuator 4 includes a control unit 80 that controls the first drive unit 60 and the second drive unit 70. The control unit 80 can switch its operation between a first picking mode and a second picking mode depending on the target object 100.

[0037] In the first picking mode, the control unit 80 drives the first drive unit 60 to sandwich the object 100 between the fixing unit 20 and the holding unit 30, and then drives the second drive unit 70 to cut the side (-Z side) of the object 100 that is sandwiched between the fixing unit 20 and the holding unit 30, of the object 100 that has passed through the first groove 21. The first picking mode, which will be described later, is suitable, for example, when the fruit stalk 102 is not slippery or the fruit 101 is light.

[0038] In the second picking mode, the control unit 80 drives the first drive unit 60 to sandwich the object 100 between the fixing unit 20 and the holding unit 30, and then drives the second drive unit 70 to cut the side of the object 100 that has passed through the first groove 21 opposite to the side sandwiched between the fixing unit 20 and the holding unit 30 (the +Z side), and then cut the side sandwiched between the fixing unit 20 and the holding unit 30 (the -Z side). The second picking mode, which will be described later, is suitable for, for example, a fruit stalk 102 that is slippery, a fruit stalk 102 that is long, or a fruit 101 that is heavy.

[0039] Fig. 6 is an operation flow diagram of the first picking mode according to the first embodiment. Fig. 6 shows the position of the hand device 10 in the first picking mode and the operation of the hand device 10 in parallel. Figs. 7 and 8 are front views showing the operation of the hand device 10 in the first picking mode according to the first embodiment. As shown in Fig. 6, in the first picking mode, the hand device 10 is first moved near the target object 100, which is a crop (step S1).

[0040] When the hand device 10 moves near the crop, it detects the stalk 102 attached to the fruit 101 to be picked (step S11). Specifically, as shown in Fig. 7(a), the hand body 11 is positioned so that the stalk 102 passes through the first groove 21 and the second groove 31 in the vertical direction, and the detection unit 50 arranged on the central axis O detects the stalk 102.

[0041] Next, the holding unit 30 is rotated to grasp the fruit stalk 102 (step S12). Specifically, as shown in FIG. 7(b), the holding unit 30 is rotated, and the second groove 31 is displaced relative to the first groove 21, thereby sandwiching the fruit stalk 102 between the fixing unit 20 and the holding unit 30. The fruit stalk 102 is sandwiched on the -Z side of the hand body 11, but not on the +Z side of the hand body 10. Depending on the thickness of the fruit stalk 102, it may be sandwiched on both the +Z and -Z sides of the hand body 10.

[0042] Next, the cutting unit 40 is rotated to cut the lower portion of the fruit stalk 102 (step S13). Specifically, as shown in Fig. 8(a), the cutting unit 40 is rotated to cut the lower portion of the fruit stalk 102 sandwiched between the fixing unit 20 and the holding unit 30. This shortens the fruit stalk 102 extending from the fruit 101, making it less likely to damage other fruits 101 in the harvest box 5 (see Fig. 1).

[0043] Next, the hand device 10 is moved to the harvest box 5 (step S2). Once the hand device 10 has moved to the harvest box 5, the grip on the fruit stalk 102 on the harvest box 5 is released (step S14). Specifically, as shown in FIG. 9(b), the holding part 30 is rotated in the opposite direction to release the fruit stalk 102 that has been clamped between the fixing part 20 and the holding part 30. As a result, the fruit 101 is placed into the harvest box 5 from the tip part 10a of the hand body 11.

[0044] When picking other fruits 101, the hand device 10 is moved to the vicinity of the crops (step S3). At this time, the hand device 10 is returned to the origin position (step S15). After that, the above-described flow is repeated. The above is the operation of the first picking mode.

[0045] Fig. 9 is an operation flow diagram of the second picking mode according to the first embodiment. Note that Fig. 9 illustrates the position of the hand device 10 in the second picking mode and the operation of the hand device 10 in parallel. Fig. 10 is a front view showing the operation of the hand device 10 in the second picking mode according to the first embodiment. As shown in Fig. 9, in the second picking mode, first, the hand device 10 is moved near the target object 100, which is a crop (step S1).

[0046] When the hand device 10 moves near the crop, it detects the stalk 102 attached to the fruit 101 to be picked (step S21). Next, the holding unit 30 rotates to grasp the stalk 102 (step S22). Note that steps S21 and S22 are the same as steps S11 and S12 described above, and operate in the same manner as in Figure 7.

[0047] Next, the cutting unit 40 is rotated to cut off the upper portion of the stalk 102 (step S23). Specifically, as shown in Fig. 10(a), the cutting unit 40 is rotated to cut off the upper portion of the stalk 102 on the +Z side of the hand body 10. This allows the stalk 102 extending from the fruit 101 to be shortened to some extent.

[0048] When the upper part of the fruit stalk 102 is cut, the weight of the fruit 101 is supported only by the clamping between the fixing part 20 and the holding part 30 on the -Z side of the hand body 11. If the fruit stalk 102 is slippery or heavy, the impact of cutting may cause the fruit stalk 102 to slide slightly downward. In this case, ensuring a certain length of the fruit stalk 102 ensures a clamping margin between the fixing part 20 and the holding part 30, preventing slippage and preventing the fruit 101 from falling.

[0049] Next, the hand device 10 is moved to the harvest box 5 (step S2). After the hand device 10 has moved to the harvest box 5, the cutting unit 40 is rotated above the harvest box 5 to cut the lower part of the stalk 102 (step S24).

[0050] 10(b), the cutting unit 40 is rotated to cut the lower portion of the stalk 102 on the -Z side of the hand body 10. As a result, the fruit 101 falls and is collected in the harvest box 5. If the fruit 101 does not fall even after cutting the lower portion of the stalk 102, the holding unit 30 may be rotated in the opposite direction as in step S15 to release the grip on the stalk 102.

[0051] When picking other fruits 101, the hand device 10 is moved to the vicinity of the crops (step S3). At this time, the hand device 10 is returned to the origin position (step S25). After that, the above-described flow is repeated. This completes the operation of the second picking mode.

[0052] As described above, the hand device 10 of this embodiment includes a rod-shaped hand body 11 that picks an object 100 with the tip 10a. The hand body 11 includes a fixing portion 20 having a first groove 21 formed at the tip 10a in a radial direction intersecting the central axis O of the hand body 11, through which the object 100 passes; a holding portion 30 that is rotatable relative to the fixing portion 20 about the central axis O and that sandwiches the object 100 between the fixing portion 20 and the holding portion 30 by displacement relative to the first groove 21; and a cutting portion 40 that is rotatable relative to the fixing portion 20 and the holding portion 30 about the central axis O and that cuts the object 100 sandwiched between the fixing portion 20 and the holding portion 30. With this configuration, fruit 101 can be picked with the tip 10a of the rod-shaped hand body 11, and therefore the vertical and lateral dimensions of the hand body 11 are small, preventing damage to other fruits 101 or fruit stalks 102. Furthermore, with this configuration, the fruit stalk 102 is held by the tip 10a of the rod-shaped hand body 11, so there is no need to suck or grasp the fruit 101 itself, and the picked fruit 101 is not damaged.

[0053] In this embodiment, the first groove 21 includes first wall surfaces 21 a, 21 b extending parallel to the radial direction. This configuration makes it easier to introduce the object 100 (such as the fruit stalk 102) hanging vertically into the first groove 21.

[0054] Furthermore, in this embodiment, the holding unit 30 includes a second groove 31 that can face the first groove 21 in the radial direction, and the second groove 31 includes second wall surfaces 31a, 31b that extend radially from the central axis O when viewed axially with respect to the central axis O. With this configuration, when the holding unit 30 is rotated, the holding unit 30 abuts against the object 100 (such as the fruit stalk 102) with a surface thereof, making it easier to clamp the object 100 and preventing the object 100 from falling after cutting.

[0055] Furthermore, in this embodiment, the cutting unit 40 is disposed radially inward of the fixing unit 20. With this configuration, the fixing unit 20 can protect the cutting unit 40, so that when the hand device 10 goes to pick up an object 100, the cutting unit 40 is less likely to damage another object 100.

[0056] In this embodiment, the hand body 11 also includes a detection unit 50 that detects the object 100. With this configuration, the accuracy with which the object 100 is picked up is improved.

[0057] In this embodiment, the detection unit 50 is disposed on the central axis O. This configuration makes it easier to detect the object 100 set in the first groove portion 21.

[0058] This embodiment also includes the hand device 10 described above, a first drive unit 60 that rotates the holding unit 30 of the hand device 10, and a second drive unit 70 that rotates the cutting unit 40 of the hand device 10. With this configuration, the holding unit 30 and the cutting unit 40 can be rotated to pick up the target object 100.

[0059] In this embodiment, the control unit 80 drives the first drive unit 60 to sandwich the target object 100 between the fixing unit 20 and the holding unit 30, and then drives the second drive unit 70 to cut the side of the target object 100 that is sandwiched between the fixing unit 20 and the holding unit 30 (the -Z side) of the target object 100 that has passed through the first groove 21 (first picking mode). This configuration shortens the stalk 102 extending from the fruit 101, thereby reducing the time required to pick the fruit 101.

[0060] In this embodiment, the control unit 80 drives the first drive unit 60 to sandwich the target object 100 between the fixing unit 20 and the holding unit 30, and then drives the second drive unit 70 to cut the side of the target object 100 passed through the first groove 21 opposite to the side sandwiched between the fixing unit 20 and the holding unit 30 (the +Z side), and then cuts the side sandwiched between the fixing unit 20 and the holding unit 30 (the -Z side) (second picking mode). With this configuration, even if the fruit stalk 102 slides slightly downward due to the impact of cutting, a certain length of the fruit stalk 102 is ensured to ensure a clamping margin between the fixing unit 20 and the holding unit 30, preventing slippage and preventing the fruit 101 from falling.

[0061] As described above, according to this embodiment, the rod-shaped hand body 11 can pick up the target object 100 without damaging other objects 100. The hand device 10 may also have the following configuration.

[0062] 11 is a perspective view of the tip 10a of the hand body 11 according to the first modification. For example, as shown in FIG. 11, the cutting unit 40 may be disposed radially outward of the fixing unit 20 and the holding unit 30. With this configuration, the cutting unit 40 can cut the fruit stalk 102 closer to the fruit 101 than the clamping portion between the fixing unit 20 and the holding unit 30, thereby shortening the fruit stalk 102.

[0063] 12A and 12B are side views of a cutting unit 40 according to a second modified example. For example, as shown in Fig. 12A, the cutting unit 40 may include a cutting blade 43A extending parallel to the central axis O. This configuration makes it easy to process the cutting blade 43A and provides excellent strength.

[0064] 12(b), the cutting unit 40 may have a cutting blade 43B that is inclined with respect to the central axis O. The cutting blade 43B has a blade width that increases on both sides in the circumferential direction toward the tip, but if the rotation direction of the cutting unit 40 is fixed to one direction, the blade width may increase on only one side in the circumferential direction. With this configuration, the fruit stalk 102 can be cut by being pulled in.

[0065] 12(c), the cutting unit 40 may be provided with a saw-like cutting blade 43C having concave and convex portions, for example, as shown in FIG. 12(c), which allows the fruit stalk 102 to be easily cut even if it is slippery.

[0066] In addition, in the cutting portion 40 shown in Figure 12, if the rotation direction of the cutting portion 40 is fixed to one direction, the edges (cutting edges) of the cutting blades 43A to 43C may be provided on only one side in the circumferential direction, or if the rotation direction of the cutting portion 40 is not fixed to one direction (if it rotates forward and backward), the edges (cutting edges) of the cutting blades 43A to 43C may be provided on both sides in the circumferential direction.

[0067] In the above embodiment, the fixing portion 20, the holding portion 30, and the cutting portion 40 are each formed in a cylindrical (pipe-like) shape, but the shape is not limited to a cylindrical shape. For example, at least one of the fixing portion 20, the holding portion 30, and the cutting portion 40 may be formed in an arc-shaped plate shape when viewed in the axial direction.

[0068] Furthermore, in the above embodiment, a configuration in which the detection unit 50 is disposed on the central axis O has been described, but the present invention is not limited to this configuration, and the detection unit 50 may be attached as close as possible to the cutting unit 40. Specifically, the detection unit 50 may be disposed at a position away from the central axis O, for example, at the bottom of the outermost fixing unit 20, and may be attached so that the fruit stalk 102 fits into the first groove 21 without protruding from the first groove 21 in plan view.

[0069] Second Embodiment Next, a second embodiment of the present invention will be described. In the following description, the same or equivalent components as those in the above-described embodiment will be denoted by the same reference numerals, and the description thereof will be simplified or omitted.

[0070] Fig. 13 is a diagram showing the internal configuration of the actuator 4 according to the second embodiment. Fig. 14 is a perspective view of area A shown in Fig. 13. As shown in these figures, the actuator 4 includes a hand device 10 that picks up an object 100 with a tip 10a, and a drive unit 90 that drives the hand device 10. In other words, the actuator 4 according to the second embodiment is configured to drive the hand device 10 with a single drive unit 90.

[0071] 13 , the hand device 10 includes a rod-shaped hand body 11 and a housing 12 that supports the hand body 11. The hand body 11 includes a fixed part 20 fixed to the housing 12, a holding part 30 that is rotatable about a central axis O relative to the fixed part 20, and a cutting part 40 that is rotatable about the central axis O relative to the fixed part 20 and the holding part 30.

[0072] The fixed portion 20 is formed in a cylindrical shape extending in the X-axis direction. A first groove 21, through which the target object 100 passes in the Z-axis direction, is formed at the end on the +X side of the fixed portion 20. The first groove 21 is formed in a substantially U-shape in plan view. The end on the -X side of the fixed portion 20 is inserted into the housing 12 and fixed to the housing 12 by a fixing member 15.

[0073] The retaining portion 30 is formed in a cylindrical shape extending in the X-axis direction and is disposed radially inward of the fixed portion 20. A second groove portion 31 that can face the first groove portion 21 in the radial direction is formed at the +X side end of the retaining portion 30. The second groove portion 31 is formed in a substantially U-shape in plan view. The -X side end of the retaining portion 30 is inserted into the housing 12 and extends to the same position as the -X side end of the fixed portion 20. The retaining portion 30 of the second embodiment is not journaled by a bearing, but is rotatably guided along the inner circumferential surface of the fixed portion 20.

[0074] The cutting portion 40 is detachably provided at the +X side end of a cylindrical support tube portion 41 that extends in the X-axis direction. The cutting portion 40 and the support tube portion 41 are arranged radially inside the holding portion 30. The -X side end of the support tube portion 41 is inserted into the housing 12 and extends further rearward than the -X side ends of the fixing portion 20 and the holding portion 30. The -X side end of the support tube portion 41 is journaled by a pair of bearings 18 provided in the housing 12.

[0075] The drive unit 90 includes a motor 91 and a power transmission mechanism 92 that transmits the torque of the motor 91 to the cutting unit 40. The motor 91 is, for example, a servo motor, and is attached to a motor attachment portion 19 provided at the bottom of the housing 12. The power transmission mechanism 92 includes a drive pulley 93, a timing belt 94, and a driven pulley 95.

[0076] The drive pulley 93 is attached to the output shaft of the motor 91. The driven pulley 95 is attached to the outer periphery of the support cylinder portion 41 between the pair of bearings 18. The driven pulley 95 is fixed to the holder 30 by a fixing member (not shown) such as a setscrew. The timing belt 94 is stretched between the drive pulley 93 and the driven pulley 95.

[0077] According to the drive unit 90 configured as described above, when the output shaft of the motor 91 rotates, the torque of the motor 91 is transmitted to the support cylinder 41 via the power transmission mechanism 92, and the cutting unit 40 rotates around the central axis O via the support cylinder 41. This allows the object 100 held at the tip 10a of the hand body 11 to be cut.

[0078] 14, the actuator 4 includes a spring portion 110 that transmits the torque of the cutting portion 40 to the holding portion 30. The spring portion 110 is a torsion coil spring that receives a torsional moment around the central axis O from the cutting portion 40 (supporting cylinder portion 41) and transmits the torsional moment to the holding portion 30, thereby rotating the holding portion 30.

[0079] An insertion hole 44 is formed in the circumferential surface of the support tube portion 41. One end 111 of the spring portion 110 is bent and extends radially and is inserted into the insertion hole 44. Furthermore, a slit 32 is formed in the end on the -X side of the holding portion 30, extending linearly from the end face of the holding portion 30 toward the +X side. The other end 112 of the spring portion 110 is bent and extends axially and is inserted into the slit 32 from the -X side.

[0080] An arc-shaped rotation restriction groove 33 extending in the circumferential direction is formed on the peripheral surface of the holding portion 30 on the +X side of the slit 32. The rotation restriction groove 33 is formed in a one-to-one correspondence with a pair of fixing members 15 that fix the fixed portion 20 to the housing 12. Ends of the fixing members 15 are inserted radially into the rotation restriction groove 33. In other words, the holding portion 30 is rotatable relative to the fixed portion 20 within the range of movement of the fixing members 15 from one end to the other end of the rotation restriction groove 33 in the circumferential direction.

[0081] Fig. 15 is a perspective view of the tip 10a of the hand main body 11 according to the second embodiment. As shown in Fig. 15, the fixed part 20 of the second embodiment includes an inner convex part 120 that protrudes onto the movement path of the holding part 30. The inner convex part 120 has a curved plate shape that conforms to the inner circumferential surface of the fixed part 20, and is fixed to the fixed part 20 by a fixing member such as a pin. The inner convex part 120 may be bonded or formed integrally with the fixed part 20.

[0082] The radial thickness of the inner convex portion 120 is preferably the same as the radial thickness of the holding portion 30. The inner convex portion 120 can face the holding portion 30 in the circumferential direction because it sandwiches the object 100 between itself and the holding portion 30. Note that the inner convex portion 120 cannot face the cutting portion 40 in the circumferential direction because it applies shear force to the object 100. The inner convex portion 120 is disposed on the periphery of the first groove portion 21 on the -Z side. The cutting portion 40 of the second embodiment has an initial position on the -Y side when viewed from the front from the central axis O. In contrast, the inner convex portion 120 is disposed on the opposite side (+Y side) from the cutting portion 40 on the periphery of the first groove portion 21.

[0083] 16A and 16B are front views showing the operation of the hand device 10 according to the second embodiment. As shown in Fig. 16A, when picking a fruit 101, the hand body 11 is positioned so that the fruit stalk 102 passes through the first groove 21 and the second groove 31 in the vertical direction, and the detection unit 50 arranged on the central axis O detects the fruit stalk 102.

[0084] 16(b), the cutting unit 40 is rotated to cut the fruit stalk 102. Specifically, when the cutting unit 40, which is located in the initial position, is rotated counterclockwise, the holding unit 30, which is connected via the spring unit 110, also rotates in the same direction. Depending on how the cutting unit 40 and the spring unit 110 are assembled, the holding unit 30 may contact the fruit stalk 102 prior to the cutting unit 40, may contact the fruit stalk 102 simultaneously with the cutting unit 40, or may contact the fruit stalk 102 later than the cutting unit 40 (while the fruit stalk 102 is being cut).

[0085] When the holding portion 30 contacts the fruit stalk 102, the fruit stalk 102 is sandwiched circumferentially between the holding portion 30 and the inner convex portion 120. Further rotation of the cutting portion 40 in this state allows the lower portion of the fruit stalk 102 to be cut. Even if the cutting portion 40 further rotates, the spring portion 110 is deformed by a torsional moment, allowing the holding portion 30 to stop with the fruit stalk 102 sandwiched in place. This allows the cut fruit stalk 102 to be held. After this, the fruit 101 with the fruit stalk 102 cut off is collected in the harvest box 5, just as in the first embodiment.

[0086] As described above, in the second embodiment, the holding unit 30 is disposed radially inward of the fixing unit 20, and the fixing unit 20 has an inner convex portion 120 that protrudes onto the movement path of the holding unit 30 and sandwiches the target object 100 between the holding unit 30 and the fixing unit 20. With this configuration, the presence of the inner convex portion 120 prevents the fruit stalk 102 from escaping into the gap between the fixing unit 20 and the cutting unit 40, even if the cutting unit 40 and the holding unit 30 rotate in the same direction, and the fruit stalk 102 can be stably cut.

[0087] The actuator 4 of the second embodiment includes a hand device 10, a drive unit 90 that rotates either the holding unit 30 or the cutting unit 40 of the hand device 10 (the cutting unit 40 in the second embodiment), and a spring unit 110 that transmits the torque of either the holding unit 30 or the cutting unit 40 to the other (the holding unit 30 in the second embodiment). This configuration allows the single drive unit 90 to fulfill two functions: gripping and cutting the fruit stalk 102. Furthermore, because the holding unit 30 is connected to the cutting unit 40 via the spring unit 110, the phase of each of the fixing unit 20, the holding unit 30, and the cutting unit 40 around the central axis O can be changed to match the diameter of the fruit stalk 102. Furthermore, the design of the spring unit 110 allows adjustment of the gripping force of the fruit stalk 102. Alternatively, the drive unit 90 may rotate the holding unit 30, and the spring unit 110 may transmit the torque to the cutting unit 40.

[0088] Third Embodiment Next, a third embodiment of the present invention will be described. In the following description, the same or equivalent components as those in the above-described embodiment will be denoted by the same reference numerals, and the description thereof will be simplified or omitted.

[0089] 17 is a front view showing the operation of the hand device 10 according to the third embodiment. As shown in FIG. 17 , the third embodiment differs from the above-described embodiments in that the holding portion 30 includes an outer protrusion 130 that protrudes into the first groove 21 of the fixing portion 20.

[0090] The outer convex portion 130 shown in Fig. 17 is formed integrally with the holding portion 30. The outer convex portion 130 may be fixed to the holding portion 30 as a separate part by a fixing member (not shown), such as a setscrew. The outer convex portion 130 protrudes radially outward and abuts against the wall surface on the -Y side of the first groove portion 21 of the fixing portion 20 in the initial position shown in Fig. 17(a).

[0091] As shown in Figure 17(b), when the cutting unit 40 is rotated in the same manner as in the second embodiment, the holding unit 30, which is connected via the spring unit 110, also rotates in the same direction. When the holding unit 30 contacts the fruit stalk 102, the fruit stalk 102 is circumferentially sandwiched between the holding unit 30 and the inner convex portion 120, and between the outer convex portion 130 and the fixing unit 20 (the wall surface on the +Y side of the first groove portion 21). Further rotation of the cutting unit 40 in this state allows the lower portion of the fruit stalk 102 to be cut. Thereafter, as in the second embodiment, the fruit 101 from which the fruit stalk 102 has been cut is collected in the harvest box 5.

[0092] As described above, in the third embodiment, the holding part 30 is disposed radially inward of the fixing part 20, and the holding part 30 includes an outer convex part 130 that protrudes into the first groove part 21 and sandwiches the object 100 between the holding part 30 and the fixing part 20. With this configuration, the length range over which the hand device 10 grasps the fruit stalk 102 is increased, so that even if the fruit stalk 102 is slippery or the fruit 101 is heavy, the fruit 101 can be reliably prevented from falling.

[0093] Fourth Embodiment Next, a fourth embodiment of the present invention will be described. In the following description, the same or equivalent components as those in the above-described embodiments will be denoted by the same reference numerals, and the description thereof will be simplified or omitted.

[0094] Fig. 18 is a perspective view of the tip 10a of the hand body 11 according to the fourth embodiment. As shown in Fig. 18, the fourth embodiment differs from the above-described embodiments in that the tip 10a of the hand body 11 is formed in a semi-cylindrical shape.

[0095] Specifically, the tip portion 10a of the hand body 11 of the fourth embodiment is formed in a semi-cylindrical shape with the upper half on the +Z side missing. In the tip portion 10a, the fixing portion 20 is disposed on the +Y side and is formed in an arc shape. An inner convex portion 120 is attached to the inner wall surface of the fixing portion 20. In addition, in the tip portion 10a, the holding portion 30 is disposed on the -Y side and is formed in an arc shape. An outer convex portion 130 is attached to the outer wall surface of the holding portion 30. The cutting portion 40 is disposed radially inside the holding portion 30 and is rotatable in the circumferential direction by a drive unit 90 (not shown).

[0096] 16 and 17, the fourth embodiment having the above-described configuration also allows for grasping and cutting of the fruit stalk 102. Furthermore, in the fourth embodiment, the upper half of the tip 10a of the hand device 10 is missing, so that even if the fruit stalk 102 is significantly bent upward, grasping and cutting can be performed without interfering with the fruit stalk 102.

[0097] Although preferred embodiments of the present invention have been described above with reference to the drawings, the present invention is not limited to the above-described embodiments. The shapes and combinations of the components shown in the above-described embodiments and modifications are merely examples, and various modifications and combinations are possible based on design requirements and the like, as long as they do not deviate from the spirit of the present invention. Furthermore, errors in dimensions and inclination are naturally allowed within the scope of the effects of the present invention.

[0098] DESCRIPTION OF SYMBOLS 1...fruit harvesting device, 2...cart, 2a...wheel, 3...robot arm, 4...actuator, 4A...waterproof cover, 5...harvesting box, 10...hand device, 10a...tip portion, 11...hand body, 12...housing, 13...first bearing, 14...second bearing, 15...fixing member, 16...first motor mounting portion, 17...second motor mounting portion, 18...bearing, 19...motor mounting portion, 20...fixing portion, 21...first groove portion, 21a...first wall surface, 21b...first wall surface, 30...holding portion, 31...second groove portion, 31a...second wall surface, 31b...second wall surface, 32...slit, 33...rotation restricting groove, 40...cutting portion, 41...support cylinder portion, 42...base, 42a...through hole, 43...cutting blade, 43A...cutting blade, 43B...cutting blade, 43C...cutting blade, 44...insertion hole , 50...detection unit, 51...sensor tube portion, 60...first drive unit, 61...first motor, 62...first power transmission mechanism, 63...drive pulley, 64...timing belt, 65...driven pulley, 66...fixed member, 70...second drive unit, 71...second motor, 72...second power transmission mechanism, 73...drive pulley, 74...timing belt, 75...driven pulley, 76...fixed member, 80...control unit, 90...drive unit, 91...motor, 92...power transmission mechanism, 93...drive pulley, 94...timing belt, 95...driven pulley, 100...object, 101...fruit, 102...fruit stalk, 110...spring portion, 111...one end portion, 112...other end portion, 120...inner convex portion, 130...outer convex portion, O...central axis, W1...width, W2...width, θ1...angle, θ2...angle

Claims

1. A hand device comprising a rod-shaped hand body for picking up an object at its tip, the hand body comprising: a fixed part at its tip having a first groove formed in a radial direction intersecting the central axis of the hand body, through which the object passes; a holding part rotatable about the central axis relative to the fixed part, which clamps the object between itself and the fixed part by displacement relative to the first groove; and a cutting part rotatable about the central axis relative to the fixed part and the holding part, which cuts the object.

2. The hand device according to claim 1, wherein the first groove portion has a first wall surface extending parallel to the radial direction.

3. A hand device according to claim 1 or 2, wherein the holding portion has a second groove portion that can face the first groove portion in the radial direction, and the second groove portion has a second wall surface that extends radially from the central axis when viewed from the axial direction of the central axis.

4. The hand device according to claim 1 or 2, wherein the cutting portion is disposed radially inward of the fixing portion.

5. A hand device according to claim 1 or 2, wherein the cutting portion is disposed radially outward of the fixing portion and the holding portion.

6. A hand device according to claim 1 or 2, wherein the holding portion is positioned radially inward of the fixed portion, and the fixed portion has an inner convex portion that protrudes onto the movement path of the holding portion and sandwiches the object between the holding portion and the fixed portion.

7. A hand device according to claim 1 or 2, wherein the holding portion is positioned radially inward of the fixed portion, and the holding portion has an outer convex portion that protrudes into the first groove portion and sandwiches the object between the holding portion and the fixed portion.

8. The hand device according to claim 1 or 2, wherein the hand body is provided with a detection unit that detects the object.

9. The hand device according to claim 8, wherein the detection unit is disposed on the central axis.

10. An actuator comprising: a hand device according to claim 1 or 2; a first drive unit that rotates the holding portion of the hand device; and a second drive unit that rotates the cutting portion of the hand device.

11. An actuator as described in claim 10, further comprising a control unit that drives the first drive unit to sandwich the object between the fixing unit and the holding unit, and then drives the second drive unit to cut the side of the object that has been passed through the first groove portion and is sandwiched between the fixing unit and the holding unit.

12. An actuator as described in claim 10, comprising a control unit that drives the first drive unit to sandwich the object between the fixed part and the holding part, and then drives the second drive unit to cut the side of the object that has been passed through the first groove part opposite to the side sandwiched between the fixed part and the holding part, and then cuts the side sandwiched between the fixed part and the holding part.

13. An actuator comprising: a hand device according to claim 1 or 2; a drive unit that rotates either the holding unit or the cutting unit of the hand device; and a spring unit that transmits the torque of either the holding unit or the cutting unit to the other.

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