JP2012201436A - Gripping device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gripping device that can respond to the shape of a workpiece flexibly and can prevent the workpiece from dropping.SOLUTION: The gripping device 1 that grips the workpiece 9 with a pair of arms 5 includes the pair of arms 5, a base 2 having a pillar 2a in a vertical direction to which the pair of arms 5 is provided, an actuator 3c for changing the interval of the pair of arms 5, and an anti-drop mechanism 4 for preventing the workpiece 9 from dropping from the gripping device 1. The anti-drop mechanism 4 moves so as to project into the space below the workpiece 9, and has an anti-drop member 4c close to the lower end of the workpiece 9.

Description

  The present invention relates to a gripping device that grips a workpiece.

  A conventional gripping device includes a base, a pair of arms provided on the base, an actuator that grips the workpiece by the arm by changing the interval between the pair of arms, and a fall prevention mechanism that supports the workpiece gripped by the arm from below. (See Patent Documents 1 and 2). The fall prevention mechanism described in Patent Document 1 has a stopper member that is attached to an arm so as to be tiltable and protrudes and descends on the lower surface of the workpiece. The fall prevention mechanism described in Patent Document 2 has a pantograph body that is provided in each arm and expands and contracts toward the other arm.

Japanese Patent Laid-Open No. 50-149052 Japanese Utility Model Publication No. 56-47897

  However, since the stopper member and the pantograph body of the conventional fall prevention mechanism move between the pair of arms, it is not easy to cope with the shape of the workpiece, for example, the height or the depth. Therefore, a gripping device that can flexibly correspond to the shape of the workpiece and prevent the workpiece from falling is conventionally required.

  In order to solve the above-mentioned problems, the present invention is a gripping device as described in each claim. According to one feature, the gripping device moves in a direction different from the arm spacing direction, a base, a pair of arms provided on the base, an actuator that changes the spacing between the pair of arms and grips the workpiece by the arm. It has a fall prevention mechanism that moves to the lower side of the work gripped by the arm and prevents the work from dropping from the gripping device.

  Therefore, the fall prevention mechanism can flexibly cope with the shape of the workpiece. For example, the fall prevention mechanism can move from the lower side to the upper side of the workpiece and flexibly correspond to the height of the workpiece to prevent the workpiece from dropping from the gripping device. Alternatively, the fall prevention mechanism can move in the depth direction of the workpiece and flexibly correspond to the depth of the workpiece to prevent the workpiece from falling from the gripping device.

  Therefore, the gripping device can flexibly correspond to the shape of the workpiece and prevent the workpiece from falling.

It is a perspective view of a holding device and a work. It is a top view of the fall prevention mechanism in the storage state. It is a top view of the fall prevention mechanism in the overhanging state. It is a perspective view of a grasping device and a work at the time of making a fall prevention mechanism into an overhanging state. It is a perspective view of a grasping device and a work at the time of raising a fall prevention member. It is a side view of a part of grasping device in another form, and a work. It is a front view of the holding | gripping apparatus and workpiece | work of FIG. It is a partial side view of the holding | gripping apparatus of FIG. 6 when an arm is inserted in a shelf. It is a partial side view of the holding | gripping apparatus of FIG. 6 at the time of moving an arm out of a shelf. It is a perspective view of a grasping device and a work in other forms. It is a perspective view of the holding | gripping apparatus and workpiece | work in FIG. 10 at the time of raising a fall prevention member. It is a simplified perspective view of the holding | gripping apparatus in another form.

  One embodiment of the present invention will be described with reference to FIGS. The gripping device 1 includes a base 2, an arm mechanism 3, and a fall prevention mechanism 4 as shown in FIG. The base 2 extends forward from a pair of columns 2a extending vertically, a lower beam 2b connecting the lower portions of the columns 2a, an upper beam 2c connecting the upper portions of the columns 2a, and the lower portions of the columns 2a. A leg 2d and a base 2f extending rearward of the column 2a at a position higher than the leg 2d are provided. Note that the vertical direction is the vertical direction in FIG. 1 and corresponds to the direction of gravity. The front-rear direction corresponds to the traveling direction of the gripping device 1, and the front is the right direction in FIG. 1 and the rear is the left direction in FIG. The left-right direction is orthogonal to the traveling direction of the gripping device 1 and corresponds to the horizontal direction.

  A wheel 2e is rotatably attached to the lower side of the tip of the leg 2d as shown in FIG. Wheels 2g are rotatably attached to the lower sides of the left and right parts of the base 2f. The wheel 2e and the wheel 2g are in contact with the floor surface on which the gripping device 1 is placed. A battery 7 and a control device 2i are mounted on the base 2f. A handle 2h is provided at the rear part of the table 2f, and the handle 2h extends upward from the table 2f. An operation panel (not shown) is attached to the handle 2h.

  As shown in FIG. 1, the arm mechanism 3 includes an arm bracket 3 a and a pair of arms 5. Each end of the arm bracket 3a is attached to each column 2a so as to be movable in the vertical direction. The arm bracket 3 a is moved up and down by an arm lift 6 provided on the base 2.

  As shown in FIG. 1, the arm lift 6 includes a male screw member 6a, a female screw member 6b, and a motor 6d. The male screw member 6a extends in the up-down direction, and each end is attached to the upper beam 2c and the lower beam 2b so as to be rotatable. The female screw member 6b is attached to the arm bracket 3a by a bracket 6c. The male screw member 6a is screwed into the female screw member 6b. The motor 6d is attached to the lower beam 2b and rotates the male screw member 6b by the electric power supplied from the battery 7. As the male screw member 6a rotates, the female screw member 6b moves up and down along the male screw member 6a.

  As shown in FIG. 1, the arm 5 has a main body plate 5a and a grip plate 5b. The base end portion of the main body plate 5a is attached so as to be movable in the left-right direction by a guide 3b provided on the arm bracket 3a. The distance between the pair of main body plates 5a can be changed by an actuator 3c provided on the arm bracket 3a.

  As shown in FIG. 1, the actuator 3c has a male screw member 3d, a pair of female screw members 3e, and a motor 3f. The male screw member 3d extends in the left-right direction, and is attached to the arm bracket 3a so as to be rotatable. A helical male screw is formed on the left outer peripheral surface of the male screw member 3d, and a male screw extending spirally in the opposite direction to the male screw formed on the left outer peripheral surface is formed on the right outer peripheral surface.

  Each female screw member 3e is attached to the main body plate 5a of the arm 5 as shown in FIG. One of the female screw members 3e is screwed to the male screw on the left outer peripheral surface of the male screw member 3d, and the other one of the female screw members 3e is screwed to the male screw on the right outer peripheral surface of the male screw member 3d. The motor 3 f is attached to the arm bracket 3 a and rotates the male screw member 3 d with the electric power supplied from the battery 7. As a result, the pair of arms 5 approaches and separates, and the distance between the arms 5 changes.

  A plurality of links 5c are provided between the main body plate 5a and the gripping plate 5b as shown in FIG. The link 5c has a first end portion rotatably attached to the main body plate 5a and a second end portion rotatably attached to the grip plate 5b. The arm 5 is provided with a spring (not shown) that biases the second end portion of the link 5c upward and positions the second end portion above the first end portion.

  When the pair of arms 5 are brought close to each other as shown in FIG. 5, each gripping plate 5 b hits the work 9, and a frictional force is generated between each gripping plate 5 b and the work 9. Each grip plate 5b moves upward with respect to the main body plate 5a by the rotation of the link 5c, and lifts the workpiece 9 by the frictional force. On the other hand, each holding plate 5b receives a downward force from the work 9 by a frictional force. Each gripping plate 5b moves downward by the rotation of the link 5c and moves toward the workpiece 9. As a result, the pair of gripping plates 5b moves toward the workpiece 9, and grips the workpiece 9 more strongly.

  As shown in FIG. 5, the fall prevention mechanism 4 includes a first member 4a, a second member 4b, a fall prevention member 4c, and an elevating body 4m. As shown in FIGS. 1 and 5, the first member 4a and the second member 4b have base portions 4a3 and 4b3 attached to the column 2a so as to be movable in the vertical direction. The 1st member 4a is box shape, Comprising: The accommodating part 4a1 and the opening part 4a2 are formed in the 1st member 4a. The storage portion 4a1 stores the folded fall prevention member 4c. The opening 4a2 opens toward the second member 4b and allows the drop prevention member 4c to be taken in and out of the storage portion 4a1.

  The second member 4b has a box shape as shown in FIGS. 2 and 3, and the second member 4b is formed with a storage portion 4b1 and an opening 4b2. The opening 4b2 opens toward the first member 4a. The tip portions 4f2 and 4g2 of the fall prevention member 4c that are moved and protruded from the first member 4a reach the storage portion 4b1 through the opening 4b2 and are supported by the second member 4b.

  The fall prevention member 4c has a pantograph format as shown in FIGS. 2 and 3 and includes four rod-like links 4d to 4g. The first link 4d has a base end portion 4d1 that is rotatably connected to the first member 4a. The second link 4e has a base end portion 4e1 that is connected to the first member 4a so as to be movable in the front-rear direction and rotatably. The links 4d and 4e intersect at the central portions 4d3 and 4e3 and are rotatably connected. The first ends 4f1 and 4g1 of the links 4f and 4g are rotatably connected to the second ends 4d2 and 4e2 of the links 4d and 4e. The links 4f and 4g intersect at the central portions 4f3 and 4g3 and are rotatably connected.

  The fall prevention member 4c is stored in the first member 4a as shown in FIG. 2 by the actuator 4n provided in the first member 4a, and the first member 4a as shown in FIGS. It can be changed to the overhanging state overhanging the lower space of the work 9 between the second members 4b. The space below the work 9 is equal to the horizontal cross-sectional shape of the work 9 and has the height of the upper end surface of the leg 2d of the gripping device 1 with the lower end of the work 9 facing vertically downward from the height of the lower end of the work 9. .

  The actuator 4n has a hydraulic cylinder that moves the base end 4e1 of the link 4e in the front-rear direction, or a motor and a male screw member that advances by the motor. The fall prevention member 4c opens between the first member 4a and the second member 4b in the retracted state, and extends between the first member 4a and the second member 4b in the overhanging state. In the extended state, the end portions 4f2 and 4g2 of the links 4f and 4g are supported by the second member 4b.

  As shown in FIG. 5, the elevating body 4m is provided between the leg 2d, the first member 4a, and the second member 4b. The elevating body 4m is in the form of a pantograph and has two rod-like links 4i and 4j and an actuator 4k. The first link 4i is rotatably connected to the first end portion 4i1 rotatably connected to the distal end portion of the leg 2d and the base end portions of the first member 4a and the second member 4b so as to be movable in the front-rear direction. The second end 4i2 is provided. The second link 4j is rotatably connected to the first end portion 4j1 connected to the base end portion of the leg 2d so as to be movable in the front-rear direction and rotatably, and to the distal ends of the first member 4a and the second member 4b. Second end 4j2. The links 4i and 4j intersect at the central portions 4i3 and 4j3 and are rotatably connected.

  The actuator 4k is provided on the leg 2d as shown in FIG. The actuator 4k has a male screw member advanced by a hydraulic cylinder or motor that moves the first end 4j1 in the front-rear direction. The elevating body 4m moves the first member 4a and the second member 4b up and down by moving the first end 4j1 back and forth by the actuator 4k.

  When the workpiece 9 is gripped and conveyed by the gripping device 1, first, the operation panel is operated, and the control device 2 i adjusts the height of the arm 5 by the arm lift 6 based on the signal transmitted from the operation panel ( (See FIG. 1). Next, the gripping device 1 is moved by the wheels 2e and 2g, and the arm 5 is inserted into the shelf. By operating the operation panel, the control device 2 i controls the actuator 3 c based on the signal transmitted from the operation panel, and the arm 5 grips the workpiece 9. The holding plate 5b of the arm 5 rises with respect to the main body plate 5a and lifts the workpiece 9 from the shelf.

  Next, the gripping device 1 is moved by the wheel 2e and the wheel 2g, and the arm 5 and the work 9 are moved out of the shelf. By operating the operation panel, the control device 2i controls the actuator 4n based on the signal transmitted from the operation panel, and the fall prevention member 4c changes from the housed state of FIGS. 1 and 2 to the extended state of FIGS. . The control device 2i controls the elevating body 4m, and the first member 4a and the second member 4b are simultaneously raised, and the fall preventing member 4c moves to a position where it abuts on or is close to the lower surface 9a of the work 9.

  Therefore, when the workpiece 9 moves downward with respect to the arm 5, the workpiece 9 can be supported by the fall prevention member 4c. Therefore, the fall prevention mechanism 4 can suppress that the workpiece 9 itself is damaged by the fall of the workpiece 9 or that a part of the gripping device 1 is damaged.

  Next, the gripping device 1 is moved by the wheels 2e and 2g to move the workpiece 9 to a predetermined position. Next, it is confirmed that the arm 5 is holding the workpiece 9. The confirmation is made by the control device 2i based on a signal from a sensor that detects the workpiece 9, or confirmed by the operator visually. The sensor is provided in the base 2, the arm mechanism 3, or the fall prevention mechanism 4. The fall prevention member 4c is lowered by a procedure reverse to the above procedure, and then the fall prevention member 4c is changed from the overhanging state to the housed state. Next, the arm 5 is lowered by a procedure reverse to the above procedure, the pair of arms 5 are separated, and the workpiece 9 is set at a desired position.

  As described above, the gripping device 1 includes the base 2, the pair of arms 5 provided on the base 2, and the actuator 3 c that grips the work 9 by the arms 5 by changing the distance between the pair of arms 5 as shown in FIG. 5. And a fall prevention mechanism 4 that moves in a direction different from the interval direction of the arms 5 and moves to the lower side of the workpiece 9 gripped by the arms 5 to prevent the workpiece 9 from dropping from the gripping device 1.

  Therefore, the fall prevention mechanism 4 can flexibly cope with the shape of the workpiece 9. For example, the fall prevention mechanism 4 can move from the lower side of the workpiece 9 to the upper side to flexibly correspond to the height of the workpiece 9 and prevent the workpiece 9 from dropping from the gripping device 1.

  As shown in FIG. 5, the gripping device 1 includes a pair of arms 5, a base 2 having a vertical column 2 a on which the pair of arms 5 are provided, an actuator 3 c that changes a distance between the pair of arms 5, a workpiece 9 has a fall prevention mechanism 4 for preventing the 9 from falling. The fall prevention mechanism 4 has a fall prevention member 4 c that moves so as to protrude into the lower space of the work 9 and close to the lower end of the work 9.

  Therefore, the fall prevention mechanism 4 can move flexibly with respect to the workpiece 9 gripped by the arm 5 in order to move separately from the arm 5. For example, it can move flexibly with respect to the workpiece 9 as compared with the case where the fall prevention mechanism is provided in the arm 5. Thus, the fall prevention mechanism 4 can flexibly correspond to the shape of the workpiece 9 and prevent the workpiece 9 from falling.

  As shown in FIG. 5, the base 2 extends in a horizontal direction from the pillar 2a, and is in contact with a leg 2d located below the arm 5 and a floor surface on which the leg 2d can be rotated and the gripping device 1 is placed. The wheel 2e is provided as possible. The fall prevention mechanism 4 includes a lift 4m that is provided on the leg 2d and moves the fall prevention member 4c up and down relative to the leg 2d. Therefore, the gripping device 1 can be moved by the wheel 2e. The fall prevention mechanism 4 is provided using the legs 2 d, and the fall prevention member 4 c rises toward the workpiece 9 held by the arm 5.

  As shown in FIG. 5, the fall prevention mechanism 4 includes a first member 4a that is moved up and down by a first lifting body 4m that is provided on the first leg 2d, and a second lifting body 4m that is provided on the second leg 2d. It has the 2nd member 4b raised / lowered by. The fall prevention member 4c is housed in at least one of the first member 4a side and the second member 4b side, and is extended from the housed state between the first member 4a and the second member 4b. It has a structure that changes to

  Therefore, the fall prevention member 4c can support the workpiece 9 from below by being in the overhanging state. By putting the fall prevention member 4c into the housed state, the space between the first member 4a and the second member 4b and between the legs 2d is opened. This allows an obstacle to be positioned between the legs 2d, and the movement range of the base 2 is widened.

  The fall prevention member 4c is provided on the first member 4a as shown in FIGS. 2 and 3, and extends from the first member 4a to the second member 4b so that the tip portions 4f2 and 4g2 supported by the second member 4b are provided. Have. Therefore, the fall prevention member 4c is positioned in the first member 4a when in the housed state. Therefore, the space between the pair of legs 2d provided with the first member 4a and the second member 4b can be widely opened (see FIG. 1). For example, the space between the pair of legs 2d can be opened wider than when the fall prevention member is housed in the base end portions of the first member 4a and the second member 4b. Thereby, the movement range of the base 2 becomes wide. In the overhanging state, the fall preventing member 4c is supported by the second member 4b at the tip portions 4f2, 4g2. Therefore, since the fall prevention member 4c is supported by the first member 4a and the second member 4b, the fall of the workpiece 9 can be prevented stably.

  As shown in FIG. 3, the fall prevention member 4c includes at least one base end portion 4e1, 4d1 rotatably supported by the first member 4a, and at least one tip end portion 4f2, movable to the second member 4b side. 4g2. Therefore, when the base end portions 4e1 and 4d1 of the fall prevention member 4c rotate with respect to the first member 4a, the distal end portions 4f2 and 4g2 of the fall prevention member 4c can move toward the second member 4b side.

  The fall prevention member 4c has a foldable structure as shown in FIG. Therefore, the fall prevention member 4c can be accommodated in the first member 4a by being folded.

  The present invention is not limited to the above-described embodiment, and may be the following form. For example, the gripping device 1 may have a fall prevention mechanism 10 shown in FIG. 6 instead of the fall prevention mechanism 4 shown in FIG. As shown in FIGS. 6 and 7, the fall prevention mechanism 10 includes a pair of guides 12, a plurality of connecting members 13, and a plurality of fall prevention members 11.

  The guide 12 has a rod shape as shown in FIGS. 6 and 7 and is provided on the outer surface of the body plate 5 a of the arm 5. The guide 12 extends in the extending direction (front-rear direction) of the arm 5. The connecting member 13 is movably attached to the guide 12. The fall prevention member 11 is a rope, a chain, etc., and is long. The fall prevention member 11 has a pair of end portions 11c connected to the connecting member 13, a pair of hanging portions 11a depending from each end portion 11c, and a central portion 11b connecting the pair of hanging portions 11a.

  As shown in FIG. 6, the guide 12 is provided with a biasing member 14 that biases the connecting member 13 toward the tip of the arm 5. The biasing member 14 is a coil spring and is provided between the rear end portion of the guide 12 and the connecting member 13 and between the connecting members 13.

  As shown in FIGS. 6 and 8, when the work 9 installed on the shelf 15 is transported by the gripping device 1, the gripping device 1 is moved and the arm 5 is inserted into the shelf 15. The hanging portion 11 a of the fall prevention member 11 hits the end portion 15 a of the shelf 15, and the fall prevention member 11 and the connecting member 13 move to the base end portion of the arm 5 against the biasing member 14.

  As shown in FIGS. 8 and 9, the work 9 is gripped and lifted by the arm 5, and the gripping device 1 is moved to move the arm 5 and the work 9 out of the shelf 15. The biasing member 14 moves the connecting member 13 toward the tip of the arm 5 by the restoring force of the spring. As a result, the fall prevention member 11 moves to the tip of the arm 5, and the central portion 11 b of the fall prevention member 11 is positioned below the lower surface 9 a of the workpiece 9. Thus, the fall prevention member 11 prevents the workpiece 9 from falling from the gripping device 1. The connecting member 13 shown in FIG. 6 is provided with a winding mechanism. The winding mechanism winds the fall prevention member 11 so that it can be discharged. Therefore, the length of the fall prevention member 11 can be adjusted according to the shape of the workpiece 9.

  As described above, the gripping device 1 grips the workpiece 9 by the arm 5 by changing the distance between the base 2, the pair of arms 5 provided on the base 2, and the pair of arms 5 as shown in FIGS. 6 and 7. An actuator 3c to be moved, and a fall prevention mechanism 10 that moves in a direction different from the interval direction of the arm 5 and moves to the lower side of the work 9 gripped by the arm 5 to prevent the work 9 from dropping from the gripping device 1.

  Therefore, the fall prevention mechanism 10 can flexibly cope with the shape of the workpiece 9. For example, the fall prevention mechanism 10 can move in the depth direction of the workpiece 9 to flexibly correspond to the depth of the workpiece 9 and prevent the workpiece 9 from dropping from the gripping device 1.

  As shown in FIG. 1, the gripping device 1 includes a pair of arms 5, a base 2 having a vertical column 2 a on which the pair of arms 5 are provided, an actuator 3 c that changes a distance between the pair of arms 5, and an arm 5. It has a fall prevention mechanism 10 (see FIG. 9) that moves to the lower surface of the work 9 gripped in step S1 and prevents the work 9 from dropping from the gripping device 1. As shown in FIGS. 6 and 7, the fall prevention mechanism 10 includes a fall prevention member 11 that is interposed between a pair of arms 5 and whose end portions 11 c are movably attached to the arms 5, and a pair of arms 5. There is a biasing member 14 that biases the end 11c of the fall prevention member 11 against the arm 5 so that the fall prevention member 11 extends below the workpiece 9 when the workpiece 9 is lifted. Therefore, the workpiece 9 can be prevented from falling by the fall preventing member 11. Since the fall prevention member 11 moves with respect to the arm 5 by the urging member 14, it can flexibly correspond to the shape of the workpiece 9.

  The fall prevention mechanism 10 has a plurality of fall prevention members 11 as shown in FIG. Therefore, the fall prevention mechanism 10 can stably receive the workpiece 9 dropped from the arm 5.

  As shown in FIG. 6, the arm 5 is provided with a guide 12 that extends in a direction in which the arm 5 extends from the base 2 and is attached so that the end portion 11 c of the fall prevention member 11 is movable. The guide 12 is provided with a biasing member 14 that biases each end 11 c of each fall prevention member 11 toward the tip of the arm 5. Therefore, when the arm 5 is moved toward the work 9 installed on the shelf 15, the fall prevention member 11 is caught on the shelf 15 and the like, and the fall prevention member 11 is against the urging member 14 at the proximal end portion of the arm 5. Move towards. When the work 9 is lifted by the arm 5, the fall prevention member 11 moves to a position where the fall prevention member 11 extends below the work 9 by the restoring force of the urging member 14.

  In another embodiment, the gripping device 1 may have a fall prevention mechanism 16 shown in FIGS. 10 and 11 instead of the fall prevention mechanism 4 shown in FIG. The fall prevention mechanism 16 includes a fall prevention member 16a and a pair of elevating bodies 16b. The fall prevention member 16a is plate-shaped and extends between the pair of legs 2d. The base end portion of the fall prevention member 16a is attached to the column 2a so as to be movable in the vertical direction.

  As shown in FIG. 11, the elevating body 16b has a pantograph format and includes a first link 16c, a second link 16d, and an actuator 16e. The first link 16c has a first end 16c1 that is rotatably connected to the distal end of the leg 2d, and a second end that is connected to the base end of the fall prevention member 16a so as to be movable in the front-rear direction and rotatably. It has a portion 16c2. The second link 16d has a first end portion 16d1 connected to the base end portion of the leg 2d so as to be movable in the front-rear direction and rotatably, and a second end connected rotatably to the distal end portion of the fall prevention member 16a. Part 16d2. The first link 16c and the second link 16d intersect at the central portions 16c3 and 16d3 and are rotatably connected.

  The actuator 16e is provided on the leg 2d as shown in FIG. The actuator 16e has a hydraulic cylinder or a motor that moves the first end portion 16d1 in the front-rear direction and a male screw member that advances by the motor. By moving the first end portion 16d1 in the front-rear direction by the actuator 16e, the fall prevention member 16a is moved up and down by the lifting body 16b.

  As described above, the fall prevention mechanism 16 has the fall prevention member 16a close to the lower end of the workpiece 9 as shown in FIGS. Therefore, the fall prevention mechanism 16 can move flexibly with respect to the work 9 gripped by the arm 5 in order to move separately from the arm 5.

  In another embodiment, the gripping device 1 may include an arm lift 17 and a fall prevention mechanism 18 shown in FIG. 12 instead of the arm lift 6 and the fall prevention mechanism 4 shown in FIG. The arm lift 17 includes a male screw member 17a, a female screw member 17b, and a motor 17d. The male screw member 17a extends in the up-down direction and is attached to the upper beam 2c and the lower beam 2b so as to be rotatable about the shaft. The female screw member 17b is attached to the arm bracket 3a and screwed to the male screw member 17a. The motor 17d is connected to the male screw member 17a via the first gear structure 17c. The first gear structure 17c connects the motor 17d and the male screw member 17a so as to be cut.

  As shown in FIG. 12, the fall prevention mechanism 18 includes a fall prevention member 18a and an elevating body 18b. The fall prevention member 18a is plate-shaped and extends between the pair of legs 2d. The base end portion of the fall prevention member 18a is attached to the column 2a so as to be movable in the vertical direction. The elevating body 18b has a male screw member 18c and a female screw member 18d. The male screw member 18c extends in the vertical direction, and is attached to the upper beam 2c and the lower beam 2b so as to be rotatable about the shaft. The female screw member 18d is attached to the fall prevention member 18a and is screwed into the male screw member 18c. The male screw member 18c is connected to the motor 17d via the second gear structure 18e. The second gear structure 18e connects the motor 17d and the male screw member 18c so that they can be cut.

  As described above, the gripping device 1 has the arm lift 17 that moves the arm bracket 3a up and down with respect to the base 2 as shown in FIG. The arm lift 17 includes a first male screw member 17a, a first female screw member 17b, a motor 17d, and a first gear structure 17c that can connect the motor 17d and the first male screw member 17b. The fall prevention mechanism 18 includes a fall prevention member 18a and an elevating body 18b. The elevating body 18b includes a second male screw member 18c, a second female screw member 18d, a second male screw member 18d and a second gear structure 18e that can connect the second male screw member 18d and the motor 17d and can rotate the second male screw member 18d by the motor 17d.

  Therefore, the arm 5 and the fall prevention member 18a can be moved up and down by the same motor 17d. Thereby, the number of parts of the holding device 1 can be reduced. Moreover, the arm 5 and the fall prevention member 18a can be lifted and lowered separately or simultaneously by the first gear structure 17c and the second gear structure 18e. Thereby, the freedom degree of the holding | grip apparatus 1 becomes high.

  The present invention is not limited to the above-described embodiment, and may be the following form. For example, the fall prevention mechanism 4 may have a fall prevention member 4c that projects in the left-right direction as shown in FIGS. 1 and 4, or may have a fall prevention member that projects and folds in the front-rear direction. good. The fall prevention member protruding in the front-rear direction is attached to the first member 4a and the second member 4b so that the left and right ends are movable in the front-rear direction, and is housed between the bases of the first member 4a and the second member 4b. Or it is located between the front-end | tip parts, and between the 1st member 4a and the 2nd member 4b is open | released.

  The fall prevention member of the fall prevention mechanism 4 may be provided on the first member 4a by folding a rectangular plate member. In this case, the folded state is stored, and the extended state is extended. Since the rectangular plate member comes close to the lower surface of the workpiece in the overhanging state, the workpiece can be prevented from falling.

  The fall prevention mechanism 10 may have a biasing member 14 that widens the intervals between the plurality of fall prevention members 11 as shown in FIGS. 6 and 8, or a biasing member that narrows the intervals between the fall prevention members 11. You may have. In the latter case, the fall prevention member is urged toward the distal end portion of the arm 5 by the urging member, and the length of the fall prevention member located at the proximal end portion of the arm 5 is located on the distal end side of the arm 5. Shorter than the length of the fall prevention member. By inserting the arm 5 into the shelf and positioning the workpiece 9 between the arms 5, the fall prevention member located on the base end side of the arm 5 is caught by the workpiece, and the fall prevention member resists the biasing member. When the workpiece 9 is pulled out of the shelf 15, the fall prevention member moves to the lower side of the workpiece 9 due to gravity.

  The lifting body 4m of the fall prevention mechanism 4 may be attached to the leg 2d as shown in FIG. 5, or may be attached to a member protruding forward from the column 2a of the base 2 separately from the leg 2d.

  As shown in FIG. 1, the actuator 3c and the arm lift 6 may have motors 3f and 6d for rotating the male screw members 3d and 6a with respect to the female screw members 3e and 6b, or the female screw members 3e and 6b. You may have the motor rotated with respect to the male screw members 3d and 6a.

  As shown in FIG. 1, the actuator 3c and the arm lift 6 may have male screw members 3d, 6a, etc., or a bag (airbag or the like) inflated by gas and a winder for winding the bag. May be.

  As shown in FIG. 6, the fall prevention member 11 may have a drooping portion 11 a and a central portion 11 b that are easily bent, or a drooping portion 11 a that is more rigid than the central portion 11 b, and the drooping portion 11 a is a shelf. 15 may be a structure in which the fall prevention member 11 reliably moves to the base end side of the arm 5 by hitting 15.

  The fall prevention mechanism 10 may have a biasing member 14 as shown in FIG. 6, or does not have the biasing member 14 and each fall prevention member when the arm 5 is inserted into the shelf 15. 11 may hit the end 15a of the shelf 15, and when the workpiece 9 is lifted by the arm 5 and moved out of the shelf 15, each fall prevention member 11 may move to the lower side of the workpiece 9 by gravity.

  As shown in FIG. 1, the gripping device 1 may be a vehicle including wheels 2e and 2g, or may be a robot including walking legs.

  As shown in FIG. 1, both of the pair of arms 5 may move with respect to the base 2, or only one of them may move with respect to the base 2.

  The fall prevention member 4c may be a pantograph type as shown in FIGS. 2 and 3, or may be a belt shape wound by a winder. The fall prevention member in this case becomes an overhanging state by being discharged from the winder, and is put in a stored state by being wound by the winder.

  The fall prevention member does not have to be in both the storage state and the overhanging state. For example, the fall prevention member may always have a configuration that projects into the space below the workpiece and can be brought close to the lower end of the workpiece in the projecting state.

  The fall prevention mechanism 10 may have a plurality of fall prevention members 11 as shown in FIGS. 6 to 9, or may have only one fall prevention member such as a plate or cloth.

DESCRIPTION OF SYMBOLS 1 ... Gripping device 2 ... Base 2d ... Leg 2e, 2g ... Wheel 3 ... Arm mechanism 3a ... Arm bracket 3c, 4n, 4k, 16e ... Actuator 3d, 6a, 17a, 18c ... Male screw member 3e, 6b, 17b, 18d ... Female screw members 4, 10, 16, 18 ... Fall prevention mechanism 4a ... First member 4b ... Second members 4c, 11, 16a, 18a ... Fall prevention members 4f2, 4g2 ... Tip portions 4m, 16b, 18b ... Elevator 5 ... Arms 6, 17 ... arm lift 6c ... bracket 9 ... work 12 ... guide 13 ... connecting member 14 ... biasing member 15 ... shelf 17c ... first gear structure 18e ... second gear structure

Claims (10)

A gripping device for gripping a workpiece with a pair of arms,
A pair of arms; a base having a vertical column on which the pair of arms are provided; an actuator that changes a distance between the pair of arms; and a fall prevention mechanism that prevents the workpiece from dropping from the gripping device. Have
The gripping device, wherein the fall prevention mechanism has a fall prevention member that moves so as to protrude into a lower space of the workpiece and / or is close to a lower end of the workpiece. The gripping device according to claim 1,
The base includes a leg that extends in a horizontal direction from the column and is positioned below the arm, and a wheel that is rotatable to the leg and is provided so as to be able to contact a floor surface on which the gripping device is placed. Have
The said fall prevention mechanism is a holding | grip apparatus which has a raising / lowering body provided in the said leg and raising / lowering the said fall prevention member with respect to the said leg. The gripping device according to claim 2,
The fall prevention mechanism includes a first member that is moved up and down by the first lifting body provided on the first leg, and a second member that is lifted and lowered by the second lifting body provided on the second leg. Have
The fall-preventing member is housed in at least one of the first member side and the second member side, and an overhang projecting between the first member and the second member from the housed state A gripping device having a structure that changes into a state. The gripping device according to claim 3,
The fall prevention member is provided on the first member, and has a tip portion that extends from the first member to the second member and is supported by the second member. A gripping device according to claim 3 or claim 4, wherein
The fall prevention member has at least one base end portion rotatably supported by the first member and at least one tip end portion movable to the second member side. The gripping device according to any one of claims 3 to 5,
The fall prevention member is a gripping device having a foldable structure. The gripping device according to claim 1,
An arm bracket provided with the pair of arms and attached to the base so as to be movable up and down; and an arm lift for raising and lowering the arm bracket relative to the base;
The arm lift includes a first male screw member extending in a vertical direction and having a male screw formed on an outer peripheral surface, a first female screw member attached to the arm bracket and screwed to the first male screw member, A motor that rotates a single male screw member with respect to the first female screw member, and a first gear structure that can connect the motor and the first male screw member;
The fall prevention mechanism has a fall prevention member attached to the base so as to be able to be raised and lowered, and a lifting body for raising and lowering the fall prevention member with respect to the base,
The elevating body includes a second male screw member that extends in the vertical direction and has an external thread formed on an outer peripheral surface thereof, a second female screw member that is attached to the fall prevention member and is screwed with the second male screw member, A gripping device having a second gear structure which is connectable to a second male screw member and the motor and can rotate the second male screw member by the motor. A gripping device for gripping a workpiece with a pair of arms,
The pair of arms, a base having a vertical column on which the pair of arms are provided, an actuator for changing a distance between the pair of arms, and a lower surface of the workpiece gripped by the arms, Having a fall prevention mechanism for preventing fall from the gripping device;
The fall prevention mechanism includes a fall prevention member interposed between the pair of arms and having an end portion movably attached to each arm, and a lower side of the workpiece when the workpiece is lifted by the pair of arms. A gripping device having a biasing member that biases the end of the fall prevention member with respect to the arm so that the fall prevention member extends to the arm. The gripping device according to claim 8, wherein
The fall prevention mechanism is a gripping device having a plurality of fall prevention members. The gripping device according to claim 9,
The arm is provided with a guide that extends from the base in a direction in which the arm extends, and the end of the fall prevention member is movably attached.
The gripping device, wherein the guide is provided with the biasing member that biases the end portions of the fall prevention members toward the distal end portion of the arm.

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