This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2022-001601 filed on Jan. 7, 2022, the contents of which are incorporated herein by reference.
The present invention relates to an end-effector exchange device that attaches, in an exchangeable manner, a member such as a tool, a jig, a chuck, a gripper or the like (hereinafter referred to as an “end effector”) to a robot arm or a transfer device.
Conventionally, a device for detachably attaching an end effector to a robot arm has been known. For example, JP 2020-131305 A discloses a tool exchange device that detachably connects a first connecting member fixed to a robot arm and a second connecting member fixed to a tool member.
In the above-described tool exchange device, when compressed air is supplied to a release chamber of the first connecting member, an output rod integrated with a piston arranged on the first connecting member moves. The output rod is provided with a retraction groove for an engagement ball, and when the output rod moves, the engagement ball can be separated from a receiving surface of the second connecting member. When the first connecting member is raised after the output rod is moved, the first connecting member is separated from the second connecting member.
The tool exchange device includes a second operating rod that engages with an end face of the piston and a first operating rod that engages with the second operating rod. When the supply of compressed air is stopped for maintenance or the like, the piston can be moved and the first connecting member can be separated from the second connecting member by manually operating the first operating rod.
However, since the tool exchange device above is provided with the operating rod that engages with the end face of the piston, the connecting member must be elongated in the moving direction of the piston, and thus the size of the device is likely to increase.
The present invention has the objective of solving the aforementioned problems.
The present invention is an end-effector exchange device including a first adapter attached to a robot arm or a transfer device and a second adapter to which an end effector is attached, wherein the first adapter is attached to the second adapter in a manner that the first adapter is configured to be coupled to and separable from the second adapter. The first adapter includes a piston driven by the supply and discharge of air, a cam member integrally coupled to the piston, and an engagement ball configured to be in contact with the side surface of the cam portion of the cam member. In a case where the cam member is in the first position, the engagement ball projects and prevents the separation of the first adapter and the second adapter. In a case where the cam member is in the second position, the engagement ball is retracted and allows the separation of the first adapter and the second adapter. The second adapter includes a separation operation hole into which a release operation tool is inserted, the release operation tool being configured to be into contact with the side surface of the cam portion.
Because the end-effector exchange device has a separation operation hole into which a release operation tool is inserted, when the supply of air is stopped, the first adapter can be separated from the second adapter manually with the release operation tool. Further, because the release operation tool is configured to be able to abut on a side surface of the cam portion, a configuration necessary for manually separating the first adapter from the second adapter can be compactly arranged while the height of the entire apparatus is reduced as much as possible.
The above and other objects, features, and advantages of the present invention will become more apparent from the following description when taken in conjunction with the accompanying drawings, in which a preferred embodiment of the present invention is shown by way of illustrative example.
An end-effector exchange device 10 according to a first embodiment of the present invention will be described with reference to
As shown in
The clamp base 32 has a fitting portion 34 to be fitted in the cylinder hole 16, a flange portion 36 extending outward from the lower end of the fitting portion 34, and a cylindrical projecting portion 38 extending downward from the lower end of the flange portion 36. The fitting portion 34 of the clamp base 32 is fitted into the cylinder hole 16 of the first adapter body 14. The flange portion 36 of the clamp base 32 is fitted into the recess 18 of the first adapter body 14. The lower end of the cylinder hole 16 is closed by the clamp base 32.
As shown in
The piston 52 is arranged in the cylinder hole 16 of the first adapter body 14 in a vertically slidable manner. A piston packing 54 mounted on the piston 52 comes into contact with the wall surface of the cylinder hole 16. A first pressure chamber 20 positioned above the piston 52 and a second pressure chamber 22 positioned below the piston 52 are formed inside the first adapter 12.
The first adapter body 14 has a first port 24 for supplying and discharging air to and from the first pressure chamber 20 and a second port 26 for supplying and discharging air to and from the second pressure chamber 22 (see
The first adapter body 14 has a plurality of fluid ports 28 that open on the side surface of the first adapter body 14. The plurality of fluid ports 28 are disposed close to, of the outer periphery of the recess 18 of the first adapter body 14, portions corresponding to the two linear sides 18a and 18b. Pipes (not shown) are connected to the plurality of fluid ports 28 to supply the fluid the end effector requires. The first adapter body 14 has a plurality of first connection flow paths 30. The first connection flow paths 30 communicate with the fluid ports 28 and open on the lower surface of the first adapter body 14.
The first connector 64 is attached to the first adapter body 14 at a position close to, of the outer periphery of the recess 18 of the first adapter body 14, a portion corresponding to the arcuate side 18d. The first connector 64 is provided with an electrical contact 65 for supplying power the end effector requires. Reference numeral 31a denotes a hole through which a bolt for attaching the first adapter 12 to the robot arm is inserted. Reference numeral 31b denotes a hole through which a pin for positioning the first adapter 12 with respect to the robot arm is inserted (see
The clamp base 32 has a hole penetrating in the vertical direction. The hole portion of the clamp base 32 is made up from an upper small-diameter hole 44a and a lower large-diameter hole 44b that is continuous with the small-diameter hole 44a via a stepped surface. As shown in
The cam member 56 is coupled to the piston 52 by means of a screw member 58 and extends downward from the piston 52. The cam member 56 is movable in the vertical direction together with the piston 52. The cam member 56 includes an upper shaft portion 60 and a lower cam portion 62 having a diameter larger than that of the shaft portion 60. The shaft portion 60 of the cam member 56 is inserted into the small-diameter hole 44a of the clamp base 32. The cam portion 62 of the cam member 56 is accommodated in the large-diameter hole 44b of the clamp base 32.
A rod packing 46 mounted on the inner periphery of the fitting portion 34 of the clamp base 32 is in sliding contact with the shaft portion 60 of the cam member 56. A seal member 48 attached to the outer periphery of the fitting portion 34 of the clamp base 32 comes into contact with the wall surface of the cylinder hole 16 of the first adapter body 14. The second pressure chamber 22 is kept airtight from the outside by the rod packing 46 and the seal member 48.
The side surface of the cam portion 62 includes a cylindrical surface 62a having a constant radius, a first tapered surface 62b being continuous with the upper part of the cylindrical surface 62a, and a second tapered surface 62c being continuous with the lower part of the cylindrical surface 62a. The first tapered surface 62b is a tapered surface the diameter of which increases upward and forms an acting surface for urging the engagement balls 66 in the projecting direction. The second tapered surface 62c is a tapered surface the diameter of which decreases downward and provides a space into which the engagement balls 66 can be retracted.
As shown in
When the cam member 56 moves upward, the engagement balls 66 face the second tapered surface 62c of the cam portion 62 and can be retreated toward the second tapered surface 62c. As shown in
The engagement balls 66 are in contact with the cylindrical surface 62a of the cam portion 62 until the cam member 56 moves upward by a predetermined length from the state in which the cam member 56 is positioned at the projecting end. While the engagement balls 66 are in contact with the cylindrical surface 62a of the cam portion 62, the state in which the engagement balls 66 project out from the projecting portion 38 of the clamp base 32 is maintained.
As shown in
As shown in
The angle defined around the central axis line X1 of the first adapter 12 by the holding holes adjacent to each other in the first group is α. The angle defined around the central axis line X1 of the first adapter 12 by the holding holes adjacent to each other in the second group is α. Further, an angle defined between the first group of holding holes and the second group of holding holes adjacent to each other across the straight line Y with respect to the central axis line X1 of the first adapter 12 is represented by β. The angle β is larger than the angle α.
By setting the angle β to be large to some extent, it is possible to arrange the notch grooves 42a and 42b at positions where the notch grooves 42a and 42b overlap the holding holes 40a to 40f in the vertical direction (height direction). That is, the length (height) of the projecting portion 38 of the clamp base 32 in the vertical direction can be made as short as possible. In this embodiment, the number of the holding holes 40a to 40c in the first group and the number of the holding holes 40d to 40f in the second group are each three. The angle α is about 50 degrees and the angle β is about 80 degrees.
As shown in
The second adapter body 70 has a hole 72 penetrating in the vertical direction. An upper portion of the hole 72 expands outward via a stepped surface, whereby a recess 74 is formed at the upper portion of the hole 72. The annular clamp plate 82 fits into the recess 74 of the second adapter body 70 and is secured to the second adapter body 70 with a plurality of bolts 84. The second adapter body 70 includes a flange portion 75 extending inward from the hole 72. The recess 74 of the second adapter body 70 and the clamp plate 82 have a quadrangular shape acquired by combining two linear sides 74a and 74b and two arcuate sides 74c and 74d when viewed from the direction along the central axis X2 of the second adapter 68. Thus, the clamp plate 82 is positioned in the circumferential direction with respect to the second adapter body 70.
The second adapter body 70 has a plurality of fluid ports 76 that open on a side surface of the second adapter body 70. The plurality of fluid ports 76 are disposed close to, of the outer periphery of the recess 74 of the second adapter body 70, portions corresponding to the two linear sides 74a and 74b. The plurality of fluid ports 76 are connected with pipes (not shown) for supplying fluid necessary for the end effector. The second adapter body 70 has a plurality of second connection flow paths 78. The second connection flow path 78 communicates with the fluid port 76 and opens on the upper surface of the second adapter body 70. Each fluid port 28 of the first adapter body 14 communicates with each fluid port 76 of the second adapter body 70 via the first connection flow path 30 and the second connection flow path 78.
The first connection flow paths 30 are disposed close to, of the outer periphery of the recess 18 of the first adapter body 14, portions corresponding to the two linear sides 18a and 18b. In this way, the first connection flow paths 30 can be arranged in wide regions outside the recess 18 of the first adapter body 14. The second connection flow paths 78 are disposed close to, of the outer periphery of the recess 74 of the second adapter body 70, portions corresponding to the two linear sides 74a and 74b. In this way, the second connection flow paths 78 can be arranged in wide regions outside the recess 74 of the second adapter body 70.
A tapered surface (engagement surface) 88 is formed on the inner periphery of the lower surface of the clamp plate 82 so as to be abutted by the engagement balls 66. While the engagement balls 66 is in contact with the tapered surface 88 of the clamp plate 82 from below, the clamp base 32 that holds the engagement balls 66 cannot move upward relative to the second adapter body 70. The clamp plate 82 has a pair of positioning holes 86 on the upper surface of the clamp plate 82. The positioning pin 37 projecting from the flange portion 36 of the clamp base 32 is inserted into the positioning hole 86 of the clamp plate 82.
As shown in
As described above, since the notch groove 42a of the clamp base 32 is disposed at a position overlapping the holding holes 40a to 40f in the height direction, it is not necessary to make the second adapter body 70 longer in the vertical direction to form the separation operation hole 80. That is, the height of the second adapter body 70 can be made as low as possible. Thus, the overall height of the end-effector exchange device 10 can be made as low as possible.
A release bolt 92 as a release operation tool is inserted and screwed into the separation operation hole 80. The distal end of the release bolt 92 enters into the notch groove 42a of the clamp base 32. An end portion of the release bolt 92 is supported by the flange portion 75 of the second adapter body 70. When the cam member 56 is at the position where the cam member 56 has moved to the projecting end, the release bolt 92 is rotated and advanced from the side surface of the second adapter 68 by using a tool such as a driver, whereby the distal end of the release bolt 92 can be brought into contact with the second tapered surface 62c of the cam member 56.
The second connector 90 is attached to the second adapter body 70 at a position close to, of the outer periphery of the recess 74 of the second adapter body 70, a portion corresponding to the arcuate side 74d. The second connector 90 is provided with electrical contacts 91 for supplying electric power necessary for the end effector. The electrical contact 91 of the second connector 90 is connected to the electrical contact 65 of the first connector 64.
The second adapter body 70 has bolt insertion holes 81 extending vertically through the second adapter body 70. The end effector is attached to the second adapter body 70 using bolts (not shown) that are inserted from the upper surface of the second adapter body 70 through the bolt insertion hole 81.
Next, an operation of coupling the first adapter 12 to the second adapter 68 by supplying and discharging air will be described. In the initial state, the first adapter 12 attached to a robot arm is separated from the second adapter 68 to which a predetermined end effector has been attached. Further, air has been supplied to the second pressure chamber 22 through the second port 26, and the cam member 56 integrated with the piston 52 has moved to the retracted end (second position).
The robot arm is driven from the initial state so that the projecting portion 38 of the clamp base 32 faces the clamp plate 82. Thereafter, the first adapter 12 is brought close to the second adapter 68 while the central axis X1 of the first adapter 12 is aligned with the central axis X2 of the second adapter 68. The projecting portion 38 of the clamp base 32 passes through a central portion of the annular clamp plate 82 and enters the bore 72 of the second adapter body 70.
At this time, although there is a possibility that the engagement balls 66 held by the clamp base 32 will come into contact with the side surface of the cam portion 62 of the cam member 56 and project out from the projecting portion 38 of the clamp base 32, a force for coupling the first adapter 12 to the second adapter 68 is not generated. This is because the cam member 56 is positioned at the retracting end (second position) and the engagement balls 66 are in a state in which the engagement balls 66 can move freely.
After the projecting portion 38 of the clamp base 32 enters the hole 72 of the second adapter body 70, air is supplied to the first pressure chamber 20 through the first port 24 and air in the second pressure chamber 22 is discharged through the second port 26. As a result, the cam member 56 integrated with the piston 52 moves downward. When the cam member 56 moves downward, the engagement balls 66 are pushed by the second tapered surface 62c of the cam portion 62 and project out from the projecting portion 38 of the clamp base 32.
Thereafter, the engagement balls 66 come into contact with the cylindrical surface 62a of the cam portion 62 and further come into contact with the first tapered surface 62b of the cam portion 62. When the engagement balls 66 come into contact with the first tapered surface 62b, the engagement balls 66 are pushed by the first tapered surface 62b and are strongly sandwiched between the first tapered surface 62b and the tapered surface 88 of the clamp plate 82. In this way, the first adapter 12 is attracted to the second adapter 68.
In this state, even if a force to separate the first adapter 12 from the second adapter 68 is applied, the first adapter 12 does not separate from the second adapter 68. This is because when a force to separate the first adapter 12 from the second adapter 68 is applied, the engagement balls 66 separate from the first tapered surface 62b of the cam portion 62 and come into contact with the cylindrical surface 62a of the cam portion 62 but a further force to move the engagement balls 66 in the retracting direction is not applied. That is, a self-locking state is achieved. In this way, the coupling of the first adapter 12 with the second adapter 68 is completed.
Next, an operation in a case where the first adapter 12 is separated from the second adapter 68 by supplying and discharging air will be described. The first adapter 12 is coupled to the second adapter 68, and work is performed by a robot arm to which a predetermined end effector has been attached. Thereafter, when the end effector is replaced, it is necessary to separate the first adapter 12 from the second adapter 68. This is because attachment and detachment of the end effector to and from the second adapter body 70 are performed by inserting and removing bolts from the upper surface of the second adapter body 70 through the bolt insertion holes 81.
To separate the first adapter 12 from the second adapter 68, air is supplied to the second pressure chamber 22 through the second port 26, and air in the first pressure chamber 20 is discharged through the first port 24. Thus, the cam member 56 integrated with the piston 52 moves to the retracting end, and the engagement balls 66 can be retracted to a position where the engagement balls 66 do not project out from the projecting portion 38 of the clamp base 32 (see
Next, a case where the first adapter 12 is separated from the second adapter 68 by the operation of the release bolt 92 will be described. It is assumed here that the supply of air for separating the first adapter 12 from the second adapter 68 has stopped, or that the thrust of the piston 52 has been lost due to breakage or the like of the piston packing 54. In this case, the first adapter 12 can be forcibly separated from the second adapter 68 by manually operating the release bolt 92 as explained below.
The operator screws the release bolt 92 from the side surface of the second adapter 68 using a tool such as a driver and brings the distal end of the release bolt 92 into contact with the second tapered surface 62c of the cam member 56. At this time, it is desirable to support the second adapter 68 or the end effector in some way so that the second adapter 68 or the end effector does not move. Without such support, when the cam member 56 moves to a position where the engagement balls 66 contact the second tapered surface 62c, a gap is created between the first adapter 12 and the second adapter 68, and the amount the cam member 56 is pushed up by the release bolt 92 is reduced. When the release bolt 92 is further screwed, the cam member 56 can be pushed to the retracted end (see
When the cam member 56 is pushed in to the retracting end, the engagement balls 66 can be retracted to a position where the engagement balls 66 do not project out from the projecting portion 38 of the clamp base 32. In this state, if a force is applied to separate the first adapter 12 from the second adapter 68, the engagement balls 66 are pushed by the tapered surface 88 of the clamp plate 82 and retracted to a position where the engagement balls 66 do not project out from the projecting portion 38 of the clamp base 32. Thus, the first adapter 12 separates from the second adapter 68.
The end-effector exchange device 10 according to the present embodiment has the separation operation hole 80 into which the release bolt 92 is inserted. Therefore, when the supply of air is stopped, the first adapter 12 can be separated from the second adapter 68 by manually operating the release bolt 92. The notch groove 42a of the clamp base 32 is arranged at a position overlapping the holding holes 40a to 40f in the height direction, and the separation operation hole 80 of the second adapter body 70 is formed at a position corresponding to the notch groove 42a. Therefore, the height of the projecting portion 38 of the clamp base 32 can be made as low as possible, and the height of the second adapter body 70 can be made as low as possible. Therefore, the overall height of the end-effector exchange device 10 can be made as low as possible.
Next, an end-effector exchange device 100 according to a second embodiment of the present invention will be described with reference to
The second adapter body 70 of the end-effector exchange device 100 has a pair of slits 102 on the side surfaces of the second adapter body 70. The pair of slits 102 are used to support the second adapter 68 on a stand (not shown). The second adapter 68 is supported, for example, on a stand installed on the floor surface in a state in which the central axis line X2 of the second adapter 68 is oriented in the horizontal direction.
The second adapter body 70 has a plurality of connection flow paths 104 for supplying fluid the end effector requires. Each connection flow path 104 penetrates the second adapter body 70 in the vertical direction. Each fluid port 28 of the first adapter body 14 communicates with each connection flow path 104 of the second adapter body 70 via the first connection flow path 30. The second adapter body 70 does not have a fluid port opening on a side surface.
The pair of slits 102 and the plurality of connection flow paths 104 are disposed close to, of the outer periphery of the recess 74 of the second adapter body 70, portions corresponding to two linear sides 74a and 74b. Thus, the pair of slits 102 and the plurality of connection flow paths 104 can be arranged in wide regions on the outer periphery of the recess 74 of the second adapter body 70.
According to the end-effector exchange device 100 according to the present embodiment, in a case where the second adapter body 70 is formed with the pair of slits 102, it is possible to form the slits at a portion of the second adapter body 70, the portion having a sufficient space.
Next, an end-effector exchange device 110 according to a third embodiment of the present invention will be described with reference to
The second adapter body 70 has a separation operation hole 112 into which a release rod 114 as a release operation tool is inserted. The separation operation hole 112 is not provided with an internal thread. The separation operation hole 112 opens on a side surface of the second adapter body 70 and extends to the hole 72 of the second adapter body 70. The separation operation hole 112 is formed at a position corresponding to the notch groove 42a of the projecting portion 38 of the clamp base 32. The release rod 114 includes a rod-shaped insertion portion 114a and a grip portion 114b for coaxially coupling and supporting the insertion portion 114a. The distal end of the insertion portion 114a is rounded.
It is assumed here that the supply of air for separating the first adapter 12 from the second adapter 68 has stopped, or that the thrust of the piston 52 has been lost due to breakage or the like of the piston packing 54. In this case, the operator can forcibly separate the first adapter 12 from the second adapter 68 by inserting the release rod 114 into the separation operation hole 112 of the second adapter body 70.
When the release rod 114 is inserted into the separation operation hole 112 of the second adapter body 70, the distal end of the release rod 114 comes into contact with the second tapered surface 62c of the cam member 56. At this time, as in the case of the first embodiment, it is desirable that the second adapter 68 or the end effector is supported in some way so as not to move. When the operator pushes the release rod 114, the cam member 56 can be pushed to the retracted end. When the supply of air is stopped, since the pressure of air does not act on the cam member 56 integrated with the piston 52, only a small force is required to push the release rod 114 inward.
When the cam member 56 is pushed in to the retracting end, the engagement balls 66 can be retracted to a position where the engagement balls 66 do not project out from the projecting portion 38 of the clamp base 32. In this state, if a force is applied to separate the first adapter 12 from the second adapter 68, the engagement balls 66 are pushed by the tapered surface 88 of the clamp plate 82 and retracted to a position where the engagement balls 66 do not project out from the projecting portion 38 of the clamp base 32. Thus, the first adapter 12 separates from the second adapter 68.
According to the end-effector exchange device 110 of the present embodiment, since the separation operation hole 112 is not provided with an internal thread, the separation operation hole 112 can be formed in the second adapter body 70 by a simple drilling process.
The end-effector exchange device according to the present invention is not limited to the above-described embodiment, and various configurations can be adopted without departing from the gist of the present invention.
Number | Date | Country | Kind |
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2022-001601 | Jan 2022 | JP | national |