WO2019225126A1

WO2019225126A1 - Tool exchange device, master unit, and tool unit

Info

Publication number: WO2019225126A1
Application number: PCT/JP2019/010611
Authority: WO
Inventors: 悠竹林; 翔太森口
Original assignee: 株式会社コガネイ
Priority date: 2018-05-22
Filing date: 2019-03-14
Publication date: 2019-11-28
Also published as: JP7196166B2; JPWO2019225126A1

Abstract

This tool exchange device is provided with a master unit (11) and a tool unit (12) removably mounted on the master unit (11), and is configured so that a ball holder (34) is attached to a master block (13). The ball holder (34) projects from a mounting surface (16), and is provided with a flange part (36) that contacts a step difference surface (33) and a cylindrical part (35) on which balls (38) are mounted. A piston (41) provided with a ball drive part (43) is built in so as to be capable of reciprocating in the axial direction in a large-diameter hole (32). An engaging ring (58) is fitted into an accommodating hole (56) in a seal block (21), and a ball-engaging surface (58c) is provided to the engaging ring (58).

Description

Tool changer, master unit and tool unit

The present invention relates to a technique of a tool changer provided with a master unit attached to a moving member and a tool unit detachably attached to the master unit.

A tool changer is used to attach a tool unit to which a tool for gripping or processing a workpiece is attached to a moving member such as a robot arm. The tool changer is also called a tool changer, and includes a master unit attached to a moving member and a tool unit detachably attached to the master unit. A plurality of tool units each having a tool attached thereto are arranged on the support base, and any one of the tool units is automatically mounted on the master unit in accordance with an operation on the workpiece such as processing or conveyance.

Conventionally, as such a tool changer, there is an automatic attachment / detachment device as described in Patent Document 1. This automatic attachment / detachment apparatus has an apparatus main body as a master unit and a connection part as a tool unit. The apparatus main body is attached to a moving member such as a robot arm, and the connecting portion is detachably attached to the apparatus main body. All of the multiple connection parts can be mounted on the main body, and the tool support base is equipped with a connection part with a hand for gripping the workpiece and a connection part with a tool for processing the work. Has been. One of the connecting portions, that is, the tool unit is attached to the apparatus main body according to the operation by the robot arm.

JP-A-4-300177

In the automatic attachment / detachment apparatus described above, a cylindrical member having a plurality of steel balls is provided in the apparatus main body, and an engagement surface that engages with the steel balls is provided in the connection portion. A piston rod is provided on the apparatus main body, and a taper surface for projecting the steel ball toward the engagement surface is provided on the piston rod. The piston rod is driven by the piston. The apparatus main body is provided with a head cover and a rod cover, and a pneumatic chamber, that is, a pressurizing chamber, is formed between the head cover and the piston and between the rod cover and the piston, respectively. The piston rod passes through the rod cover, the cylindrical member provided with the steel ball is disposed on the outer surface of the rod cover, and the cylindrical member is attached to the apparatus main body by a plurality of bolts that penetrate the flange portion.

As described above, since the cylindrical member holding the steel ball is attached to the apparatus main body by the plurality of bolts penetrating the flange portion, the diameter of the apparatus main body cannot be reduced. Similarly, an annular member having an engagement surface is attached to the connection portion by a plurality of bolts, and the automatic attachment / detachment device composed of the apparatus main body and the connection portion cannot be reduced in size. When the automatic attachment / detachment device becomes large, its weight increases. If the automatic attachment / detachment device becomes large and heavy, the automatic attachment / detachment device cannot be moved quickly by an industrial robot arm, etc. It was not possible to move the work quickly.

An object of the present invention is to achieve miniaturization of the master unit and the tool unit constituting the tool changer, and to reduce the size and weight of the tool changer.

Another object of the present invention is to enable a tool changer to be moved quickly by a moving member by reducing the size and weight of the tool changer.

The tool changer of the present invention is a tool changer comprising a tool unit to which a tool is attached and a master unit to which the tool unit is detachably attached, wherein the master unit includes an attachment surface, and the attachment surface A mounting surface that faces the mounting surface, a small-diameter hole that opens in the mounting surface, a large-diameter hole that opens in the mounting surface and communicates with the small-diameter hole, and a first hole formed between the large-diameter hole and the small-diameter hole. A master block having a step surface, a cylindrical portion in which a plurality of balls are mounted and press-fitted into the small-diameter hole, and a tip projects from the mounting surface, and a flange portion abutted against the first step surface, A ball holder attached to the master block; a ball driving unit provided at a tip; and a reciprocating motion in the axial direction in the large-diameter hole; A piston that forms a first pressurizing chamber, and a head cover that is attached to the large-diameter hole and forms a second pressurizing chamber with the piston, wherein the tool unit is the master An abutting surface that is abutted against the mounting surface of the block; a tip surface that faces the abutting surface and to which the tool is attached; an insertion hole that opens in the abutting surface and into which the ball holder is inserted; and the tip A tool block having a receiving hole opened in a surface and having a diameter larger than the insertion hole, and a second step surface formed between the insertion hole and the receiving hole, and the receiving from the tip surface side An engagement ring that is press-fitted into the hole, is abutted against the second step surface and is fixed to the tool block, and is formed in a tapered shape on the engagement ring, and is driven radially outward by the ball driving unit. Said Le has a ball engaging surface engaging.

The master unit of the present invention is a master unit to which a tool unit to which a tool is attached is detachably mounted, and includes a mounting surface, a mounting surface facing the mounting surface, and a small-diameter hole opening in the mounting surface. A large-diameter hole that opens in the mounting surface and communicates with the small-diameter hole, a master block having a step surface formed between the large-diameter hole and the small-diameter hole, and a plurality of balls mounted on the small-diameter hole. A cylindrical portion that is press-fitted and has a tip projecting from the mounting surface, and a flange portion that abuts against the stepped surface, a ball holder that is attached to the master block, a ball drive portion is provided at the tip, and the large-diameter hole A piston that is reciprocally movable in the axial direction and forms a first pressurizing chamber with the step surface, and is attached to the large-diameter hole, and a second between the piston and the piston. And a second cover for allowing the ball to move in the radial direction. The first position pushes the ball outward in the radial direction via the ball driving unit. And the ball holder is fixed to the master block by press-fitting the cylindrical portion into the small-diameter hole.

The tool unit of the present invention is a tool unit to which a tool is attached and is detachably attached to the master unit, the abutting surface being abutted against the mounting surface of the master unit, and the abutting surface facing the abutting surface. A distal end surface to which an operating device is attached, an insertion hole opened in the abutting surface, an accommodation hole opened in the distal end surface and larger in diameter than the insertion hole, and formed between the insertion hole and the accommodation hole A tool block having a stepped surface, an engagement ring that is press-fitted into the receiving hole from the tip surface side, and is abutted against the stepped surface, and a tapered ball engagement formed on the engagement ring And the engagement ring is fixed to the tool block by press-fitting the engagement ring into the receiving hole.

The master unit has a master block and a ball holder, the flange portion of the ball holder is abutted against the step surface, and the cylindrical portion is press-fitted into a small-diameter hole formed in the master block. The ball holder is fixed to the master block by pressing the cylindrical portion into the small diameter hole. Therefore, the master block can be made smaller and lighter than when the flange portion is fixed to the master block with the bolt. The tool unit has a tool block and an engagement ring, and the engagement ring is inserted into the accommodation hole from the front end surface side of the tool block and is abutted against the step surface. Since the engagement ring is press-fitted into the tool block, the tool block can be made smaller and lighter than when the engagement ring is fixed with a bolt.

The tool unit can be reduced in size and weight by reducing the size and weight of the master unit and the tool unit, so the moving member such as the robot arm to which the tool changer is attached can be moved at high speed. The production efficiency of mass-produced products can be greatly improved.

It is a perspective view which shows the master unit and tool unit of the tool exchange apparatus which are one Embodiment. FIG. 2 is a cross-sectional view taken along line AA in FIG. It is a bottom view which shows the mounting surface of the master block shown by FIG. It is sectional drawing which shows the part similar to FIG. 2 in the middle of attaching the tool unit to a master unit. It is sectional drawing which shows the part similar to FIG. 2 in the state which completed mounting | wearing of the tool unit to the master unit. FIG. 5 is a plan view of FIG. 4. FIG. 7 is a sectional view taken along line BB in FIG. 6. FIG. 7 is a pneumatic piping diagram connected between the supply / discharge port and the air supply source shown in FIG. 6. FIG. 6 is a sectional view taken along line CC in FIG. 5. (A) is sectional drawing which shows the packing with which a packing mounting hole is mounted | worn, (B) is sectional drawing which shows the packing with which the packing mounting hole was mounted | worn. It is a pneumatic piping diagram connected between the tool with which the tool unit was mounted | worn, and a pneumatic supply source.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. As shown in FIGS. 1 and 2, the tool changer 10 includes a master unit 11 and a tool unit 12, and the tool unit 12 is detachably attached to the master unit 11. The master unit 11 has a substantially cylindrical master block 13 and is attached to an arm of an industrial robot. The master block 13 is made of an aluminum alloy. The outer peripheral surface of the master block 13 is formed by an arc surface 14a and a flat connector mounting surface 14b. In the drawing, the upper surface is an attachment surface 15 attached to a robot arm or the like, and the lower surface facing the attachment surface 15 is an attachment surface 16 on which the tool unit 12 is attached. The master unit 11 is attached to a moving member such as a robot arm for moving a tool.

In order to attach the master unit 11 to a moving member provided with a through hole with a fixing member having a female screw such as a bolt, four screw holes 17 are provided in the master block 13 so as to open to the attachment surface 15. Each screw hole 17 is provided at the same radial position from the central axis O of the master block 13 at intervals of 90 degrees in the circumferential direction. On the other hand, in order to attach the master unit 11 to the moving member provided with the female screw, four bolt attachment holes 18 are opened in the attachment surface 15 and provided in the master block 13. Each bolt mounting hole 18 is a stepped hole, and is provided at the same radial position from the central axis O at intervals of 90 degrees in the circumferential direction. Thus, the master unit 11 is attached to the moving member by the screw hole 17 or the bolt attachment hole 18. For positioning in the circumferential direction when the master unit 11 is mounted on the moving member,

positioning holes

19a and 19b into which positioning pins provided on the robot arm are inserted are formed in the mounting surface 15 and formed in the master block 13. ing.

The tool unit 12 has a substantially annular tool block 21, and a tool for gripping or processing a workpiece is attached to the tool unit 12. Examples of tools include pneumatic chucks, air drills, and electric drills. The pneumatic chuck grips a workpiece by opening and closing the finger member with air pressure. Air drills and electric drills drill holes in workpieces.

The tool block 21 is made of an aluminum alloy. The outer peripheral surface of the tool block 21 is formed by an arc surface 22a and a flat connector mounting surface 22b. In the drawing, the upper surface is an abutting surface 23 that abuts against the master unit 11, and the lower surface that faces the abutting surface 23 is a tip surface 24 to which a tool is attached. In order to mount the tool, four bolt mounting holes 25 are provided through the tool block 21, and each bolt mounting hole 25 is a stepped hole and is located at the same radial position from the central axis O of the tool block 21. They are shifted 90 degrees in the circumferential direction.

When a pneumatic actuator is connected to the tool unit 12, a signal line such as a sensor switch provided in the pneumatic actuator is connected to a connector attached to the connector attachment surface 22b. When an electric device such as an electric driver is connected to the tool unit 12, an output signal line such as an encoder provided in the electric device or a drive signal line of a motor attached to the electric device is attached to the connector attachment surface 22b. Connected to the connector.

When the tool unit 12 is mounted on the master unit 11, in order to position the tool unit 12 in the circumferential direction with respect to the master unit 11, as shown in FIG. 13 is attached. The positioning pins 26a and 26b are made of steel, and the central axes O1 and O2 are shifted by 180 degrees in the circumferential direction about the central axis O. Each

positioning pin

26a, 26b has

fitting portions

27a, 27b protruding from the master block 13, and the

fitting portions

27a, 27b are inclined so that the distal end surface is thinner than the base end portion, The entire surface is a tapered surface. Positioning holes 28 a and 28 b into which the positioning pins 26 a and 26 b are inserted are provided in the tool block 21.

Bushings

29a and 29b made of steel are attached to the large diameter portions of the

positioning holes

28a and 28b. The fitting portion 27a of the positioning pin 26a is fitted into the fitting hole 29c of the bush 29a, and the positioning pin 26b is fitted. The joint portion 27b is fitted into the fitting hole 29d of the bush 29b. Thereby, the tool unit 12 is positioned at a predetermined circumferential position with respect to the master unit 11. The center axes O1, O2 of the positioning pins 26a, 26b are coaxial with the center axes of the

fitting holes

29c, 29d. By using the

fitting portions

27a and 27b of the positioning pins 26a and 26b as tapered surfaces, the positioning pins 26a and 26b can be easily removed from the

positioning holes

28a and 28b, and the tool unit 12 can be easily detached from the master unit 11. .

If one positioning pin 26a is a first positioning pin and the other pin 26b is a second positioning pin, as shown in FIG. 3, the proximal end portion side of the fitting portion 27a of the first positioning pin 26a is used. The cross section is circular. On the other hand, the cross section of the base end side of the fitting portion 27b of the second positioning pin 26b is substantially rhombus and has four flat surfaces 30.

As shown in FIG. 3, let R be a radial line perpendicular to the central axis O and perpendicular to the central axis O1 of the positioning pin 26a. The radial line R is also orthogonal to the central axis O2 of the positioning pin 26b, and the two flat surfaces 30 adjacent to each other centering on the radial line R intersect. The distance d of the base end portion of the fitting portion 27b in the direction of the radial line R is set shorter than the diameter D of the base end portion of the fitting portion 27b in the direction perpendicular to the radial direction line R. The diameter D coincides with the inner diameter of the fitting hole 29d on the abutting surface 23 side, and the distance d is slightly smaller than the inner diameter of the fitting hole 29d on the abutting surface 23 side. For example, the distance d is set to be about 0.1 mm smaller than the diameter D.

Therefore, a gap corresponding to the difference (Dd) is formed between the fitting portion 27b of the second positioning pin 26b and the fitting hole 29d. The gap is formed in a direction along a radial line R that intersects the central axis O of the piston 41 and the central axis O1 of the first positioning pin 26a. On the other hand, the diameter of the circular arc part 30a in which the notch surface 30 is not provided is the same diameter as the fitting hole 29d. That is, even if there is a dimensional error in the radial direction between the central axis O1 of the first positioning pin 26a and the central axis O2 of the second positioning pin 26b, the first positioning pin 26a is used as a reference. The second positioning pin 26b moves in the direction of the radial line R. Thereby, when the tool unit 12 and the master unit 11 are combined, the dimensional error in the radial direction between the central axis O1 and the central axis O2 can be absorbed.

As shown in FIG. 2, a small-diameter hole 31 is formed in the master block 13 so as to open in the mounting surface 16. A large-diameter hole 32 having an inner diameter larger than that of the small-diameter hole 31 is formed in the master block 13 so as to open in the mounting surface 15. The large diameter hole 32 is coaxial with the small diameter hole 31 and communicates with the small diameter hole 31. A first step surface 33 is formed between the small diameter hole 31 and the large diameter hole 32. A ball holder 34 is attached to the master block 13. The ball holder 34 includes a cylindrical portion 35 and a flange portion 36, and the cylindrical portion 35 protrudes from the mounting surface 16. A plurality of ball support holes 37 penetrating radially between the inner surface 35 a and the outer surface 35 b of the cylindrical portion 35 are formed in the cylindrical portion 35. Each ball support hole 37 is a tapered surface inclined such that the inner diameter increases from the outer surface 35b toward the inner surface 35a. The central axis of each ball support hole 37 is provided on the same plane parallel to the mounting surface 16. A ball 38 made of steel is held in each ball support hole 37.

The ball holder 34 is fixed to the master block 13 by press-fitting the cylindrical portion 35 into the small diameter hole 31. When the ball holder 34 is attached to the master block 13, the ball holder 34 is inserted into the large diameter hole 32 from the attachment surface 15 side where the large diameter hole 32 is opened, and then the cylindrical portion 35 is press-fitted into the small diameter hole 31. A large-diameter hole 32 having a diameter larger than the diameter of the flange portion 36 opens in the mounting surface 15 and the ball holder 34 is inserted from the mounting surface 15 side. Therefore, the ball holder 34 can be easily inserted from the mounting surface 15 side. can do. Therefore, the cylindrical portion 35 of the ball holder 34 can be easily press-fitted into the small diameter hole 31.

Thus, since the ball holder 34 is fixed to the master block 13 by press-fitting, the diameters of the master block 13 and the flange portion 36 are smaller than when the flange portion 36 is fixed to the master block 13 with bolts. And the master unit 11 can be made lightweight. As a result, the tool changer 10 can be reduced in size and weight, and the tool changer 10 can be quickly moved at a high speed by a moving member such as a robot arm.

The piston 41 is incorporated in the large-diameter hole 32 so as to reciprocate in the axial direction. A rod portion 42 made of a steel material is integrally provided on the tip end side of the piston 41, and a ball driving portion 43 is attached to the rod portion 42. The central axis of the rod part 42 coincides with the central axis O of the master block 13. The rod portion 42 and the ball driving portion 43 are inserted into the cylindrical portion 35 of the ball holder 34, and the gap between the rod portion 42 and the cylindrical portion 35 is sealed by a seal member 40. A first pressurizing chamber 44 is formed between the piston 41 and the flange portion 36. The head cover 45 is attached to the attachment surface 15 side of the large diameter hole 32. The head cover 45 is fixed to the master block 13 by a retaining ring 46, and the retaining ring 46 is attached to an annular groove formed in the large diameter hole 32. A second pressurizing chamber 47 is formed between the head cover 45 and the piston 41. A compression coil spring 48 is mounted between the head cover 45 and the piston 41, and the compression coil spring 48 biases the piston 41 in a direction toward the tip surface of the ball holder 34, that is, in a forward direction.

When compressed air is supplied to the second pressurizing chamber 47, the pressure of the air in the direction to advance the piston 41 is urged in addition to the spring force, and the piston 41 is driven to the forward limit position, that is, the first position. . On the other hand, when compressed air is supplied to the first pressurizing chamber 44, the pressure of the air in the direction of retreating the piston 41 is biased against the spring force, and the piston 41 reaches the retreat limit position, that is, the second position. Driven. An annular groove 51 is formed on the step surface 33, and an O-ring 52 is provided in the annular groove 51. The O-ring 52 seals between the stepped surface 33 and the flange portion 36 and prevents the compressed air supplied to the first pressurizing chamber 44 from leaking from between the ball holder 34 and the master block 13. . In order to seal between the outer peripheral surface of the piston 41 and the large-diameter hole 32, the piston 41 is provided with a seal member 53. Further, a seal member 54 is provided on the head cover 45 in order to seal between the outer peripheral surface of the head cover 45 and the large diameter hole 32.

The ball drive unit 43 includes a small-diameter distal end 43a whose outer peripheral surface is parallel to the central axis O, and a drive surface 43b whose diameter gradually increases from the distal end 43a toward the base end on the rod portion 42 side. Have. Furthermore, the ball drive unit 43 has a lock surface 43d that gradually increases in diameter from the drive surface 43b toward the base end via the large diameter portion 43c toward the base end. In FIG. 2, the piston 41 is driven to the retreat limit position and is in contact with the head cover 45. At this time, the tip end portion 43 a and the drive surface 43 b of the ball drive portion 43 are in contact with the ball 38, and the ball 38 is prevented from falling into the cylindrical portion 35.

2, the insertion hole 55 is formed in the tool block 21 so as to open to the abutting surface 23. An accommodation hole 56 having an inner diameter larger than that of the insertion hole 55 is formed in the tool block 21 so as to open to the distal end surface 24. The accommodation hole 56 is coaxial with the insertion hole 55 and communicates with the insertion hole 55. A second step surface 57 is formed between the insertion hole 55 and the accommodation hole 56. An engagement ring 58 made of steel is attached to the tool block 21. The engagement ring 58 is fixed to the tool block 21 by press-fitting the engagement ring 58 into the accommodation hole 56. When the engagement ring 58 is attached to the tool block 21, the engagement ring 58 is press-fitted into the accommodation hole 56 from the distal end side portion 56 a of the accommodation hole 56 and is abutted against the step surface 57. Since the distal end side portion 56a has a larger diameter than the accommodation hole 56, the engagement ring 58 can be easily inserted into the distal end side portion 56a, and the press-fitting operation of the engagement ring 58 into the accommodation hole 56 can be performed. It can be done easily.

As described above, since the engagement ring 58 is fixed to the tool block 21 by press fitting, the diameter of the engagement ring 58 is made smaller than that when the engagement ring 58 is fixed to the tool block 21 with a bolt. In addition, the tool unit 12 can be reduced in weight. As a result, the tool changer 10 can be reduced in size and weight, and the tool changer 10 can be quickly moved at a high speed by a moving member such as a robot arm.

The engagement ring 58 has a ball guide surface 58b on the abutting surface 23 side and a ball engagement surface 58c on the opposite side through a small diameter portion 58a. The ball guide surface 58b has a tapered shape inclined so as to have a small diameter toward the ball engaging surface 58c, and the ball engaging surface 58c has a tapered shape inclined so as to have a small diameter toward the ball guide surface 58b. The ball guide surface 58b and the ball engagement surface 58c have opposite inclination directions.

As shown in FIG. 2, when pressure is supplied to the first pressurizing chamber 44 and the piston 41 is in the second position and the piston 41 is in contact with the head cover 45, the ball 38 is It is in contact with the distal end portion 43 a and the drive surface 43 b of the drive portion 43, and does not protrude outward in the radial direction from the outer surface 35 b of the cylindrical portion 35. The ball 38 is movable radially outward. Under this state, the tool unit 12 and the master unit 11 are brought close to each other so that the

fitting portions

27a and 27b are fitted to the

bushes

29a and 29b, and the cylindrical portion 35 of the ball holder 34 is fitted to the engagement ring. When inserted inside 58, the abutting surface 23 of the tool block 21 is abutted against the mounting surface 16 of the master block 13 as shown in FIG. 4. Even when a part of the ball 38 protrudes radially outward from the ball support hole 37 when the cylindrical portion 35 is inserted into the engagement ring 58, the ball 38 is radially inward by the ball guide surface 58b. Guided.

Even if a processing error occurs in the distance between the central axes O1 and O2 of the two

positioning pins

26a and 26b, the fitting between the fitting portion 27a of the positioning pin 26a and the fitting hole 29c causes the master block 13 to A reference position with the tool block 21 is set. Then, the machining error is absorbed by the radial movement of the positioning pin 26b in the gap, and the master block 13 and the tool block 21 can be easily combined. In the embodiment, the gap is formed by providing the notch surface 30 in the positioning pin 26b. However, a similar gap may be formed by notching a part of the fitting hole 29d. good.

When compressed air is supplied to the second pressurizing chamber 47 under the state shown in FIG. 4, the piston 41 moves in the forward direction, that is, in FIG. 4 due to the spring force of the compression coil spring 48 and the pressure of the compressed air. Driven downward. When the piston 41 is driven in this direction, as shown in FIG. 5, first, the ball 38 is pushed out radially outward by the drive surface 43 b of the ball drive unit 43. Next, by the movement of the ball drive unit 43, the ball 38 is pushed radially outward by the lock surface 43d and pressed against the ball engaging surface 58c. As a result, the tool unit 12 is fastened to the master unit 11 via the balls 38. At this time, the central axis O of the piston 41 and the rod portion 42 is in a state of being coincident with the central axis O of the engagement ring 58.

When the tool unit 12 is fastened to the master unit 11, a force in a pulling direction downward in FIG. 5 is applied to the ball holder 34, but the ball holder 34 comes out when the flange portion 36 contacts the step surface 33. There is nothing. Similarly, a force in the pulling direction upward in FIG. 5 is applied to the engagement ring 58, but the engagement ring 58 does not come off when the engagement ring 58 contacts the stepped surface 57.

FIG. 7 is a cross-sectional view taken along the line BB in FIG. 6 and shows a first supply / exhaust port 61 communicating with the first pressurizing chamber 44 and a second supply / exhaust port communicating with the second pressurizing chamber 47. 62 is formed in the master block 13. As shown in FIG. 8, the supply / exhaust pipes 61a, 62b connected to the respective supply /

exhaust ports

61, 62 are connected to an electromagnetic valve 63, and an air pressure supply source is connected to the supply port of the electromagnetic valve 63. 64 is connected.

As shown in FIG. 1, tool-side air flow paths 65 to 68 are formed in the tool block 21. Master side air flow paths 71 to 74 communicating with the respective tool side air flow paths 65 to 68 are formed in the master block 13 as indicated by broken lines in FIG. 9 is a cross-sectional view taken along the line CC in FIG. 6, and shows an air flow path 66 formed in the tool block 21 and an air flow path 72 formed in the master block 13 and communicating with the air flow path 66. ing.

A packing attachment hole 75 is formed at the end on the tool side, that is, the communication end of the air flow path 72 on the master side, and the packing 76 is attached to the cylindrical packing attachment hole 75. Similarly, packing attachment holes 75 are formed in the communication end portions of the other

air flow channels

71, 73, 74 on the master side, and a packing 76 is attached to each packing attachment hole 75.

10A is a cross-sectional view showing a state before the packing 76 is attached to the packing attachment hole 75, and FIG. 10B shows a state where the packing 76 is attached to the packing attachment hole 75. FIG. The outer peripheral surface of the packing 76 has a small diameter portion 77 having substantially the same diameter as the packing mounting hole 75 and a pressure contact portion 78 having a larger diameter than this. The pressure contact portion 78 is provided on the base end side of the packing 76. When the packing 76 is mounted in the packing mounting hole 75, the pressure contact portion 78 is contracted and deformed in the radial direction more than the small diameter portion 77 and is in close contact with the packing mounting hole 75 in a pressurized state.

The tip of the packing 76 is a sharp protruding portion 79, and when the packing 76 is mounted in the packing mounting hole 75, it protrudes from the mounting surface 16 of the master block 13 as shown in FIG. When the master unit 11 and the tool unit 12 are combined, as shown in FIG. 9, the projecting portion 79 is crushed in the axial direction by the abutting surface 23 of the tool block 21 and is brought into close contact with the abutting surface 23. In this way, the packing 76 is elastically deformed so that the proximal end side is largely contracted, and is elastically deformed so that the protruding portion 79 at the distal end is contracted in the axial direction. Air leakage is prevented.

FIG. 9 shows the master unit 11 in which the packing 76 is mounted on the master block 13, but when the packing mounting hole 75 is formed in the tool block 21, the packing 76 is mounted on the tool block 21. Thus, the packing 76 is provided on one of the master block 13 and the tool block 21.

FIG. 11 shows a state in which a tool as a tool, that is, a chuck 81 is attached to the tool unit 12. The chuck 81 is attached to an adapter 82, and the adapter 82 is attached to the distal end surface 24 of the tool block 21 by a bolt (not shown) attached to the bolt attachment hole 25 shown in FIG. The chuck 81 has a cylinder 84 in which a piston 83 is incorporated so as to be able to reciprocate. A finger member 85 provided on the cylinder 84 so as to be opened and closed is driven to open and close by the reciprocating movement of the piston 83. On both sides of the piston 83, a forward pressure chamber 86 and a backward pressure chamber 87 are provided. When compressed air is supplied to the pressure chamber 86 for advance, the piston 83 moves forward and the finger member 85 is opened. On the other hand, when compressed air is supplied to the pressure chamber 87 for retraction, the piston 83 moves backward and the finger member 85 is closed.

The pipe 88 connected to the cylinder 84 communicates with the pressure chamber 86 for forward movement, and the pipe 89 connected to the cylinder 84 communicates with the pressure chamber 87 for backward movement. The pipe 88 communicates with the port 65 a of the air flow path 65, and the pipe 89 communicates with the port 66 a of the air flow path 66. The tool-side air flow path 65 communicates with the master-side air flow path 71, and a port 71 a of the air flow path 71 is opened on the outer peripheral surface of the master block 13. The tool-side air flow channel 66 communicates with the master-side air flow channel 72, and the port 72 a of the air flow channel 72 is open to the outer peripheral surface of the master block 13.

11, the pipe 91 connected to the master block 13 communicates with the port 71a, and the pipe 92 connected to the master block 13 communicates with the port 72a. An electromagnetic valve 63a is provided between the

pipes

91 and 92 and the air pressure supply source 64a. When compressed air is supplied to the port 71a by the electromagnetic valve 63a, the compressed air is supplied from the port 65a to the forward pressure chamber 86 through the pipe 88. On the other hand, when compressed air is supplied to the port 72a, the compressed air is supplied from the port 66a to the pressure chamber 87 for retraction by the pipe 89. When compressed air is supplied to the pressure chamber 87 for retraction, the finger member 85 is closed, and the object to be conveyed (not shown) can be gripped by the finger member 85. When compressed air is supplied to the pressure chamber 86 for advancing, the finger member 85 is opened, and the object to be transported that has been gripped is separated from the finger member 85.

When a compression coil spring is incorporated in the forward pressure chamber 86, the finger member 85 can be opened and closed by supplying and discharging compressed air to the backward pressure chamber 87. In that case, the pipe 88 is not used.

Compressed air can be supplied to other tools also in the

air flow paths

73 and 74 provided on the master side in communication with the

air flow paths

67 and 68 on the tool side, respectively.

The tool unit 12 is configured such that the tool is attached to the tip surface as described above, and a plurality of tool units each having various tools attached thereto are arranged on a support base (not shown). A master unit 11 is attached to the robot hand in advance, and a specific tool unit is attached to the master unit in accordance with work performed by the robot. The robot arm to which the tool unit is attached performs various operations by moving the tool changer 10. The tool changer 10 is reduced in size and weight, and the robot arm can move the tool changer 10 at high speed.

The present invention is not limited to the embodiment described above, and various modifications can be made without departing from the scope of the invention. As a tool, not only air pressure but also a tool that uses electric power as a drive source such as an electric drill can be attached to the tool unit.

The tool changer is used to attach a tool unit to which a tool is attached to a moving member such as a robot arm.

Claims

A tool changer comprising a tool unit to which a tool is attached and a master unit to which the tool unit is detachably attached,
The master unit is
A mounting surface, a mounting surface facing the mounting surface, a small diameter hole opening in the mounting surface, a large diameter hole opening in the mounting surface and communicating with the small diameter hole, and the large diameter hole and the small diameter hole. A master block having a first step surface formed therebetween;
A ball holder attached to the master block, comprising a cylindrical portion in which a plurality of balls are mounted and press-fitted into the small-diameter hole and a tip protrudes from the mounting surface, and a flange portion abutted against the first step surface;
A piston that is provided with a ball driving portion at the tip, is reciprocally incorporated in the large-diameter hole in the axial direction, and forms a first pressurizing chamber with the first step surface;
A head cover attached to the large-diameter hole and forming a second pressurizing chamber with the piston;
The tool unit is
An abutting surface that is abutted against the mounting surface of the master block; a tip surface that faces the abutting surface and to which the tool is attached; an insertion hole that opens in the abutting surface and into which the ball holder is inserted; A tool block having an accommodation hole that opens in the distal end surface and has a diameter larger than that of the insertion hole, and a second step surface formed between the insertion hole and the accommodation hole;
An engagement ring that is press-fitted into the accommodation hole from the tip surface side and is abutted against the second step surface and fixed to the tool block;
A tool changer comprising: a ball engaging surface which is formed in a taper shape on the engagement ring and engages with the ball driven radially outward by the ball driving unit.
The tool changer according to claim 1, wherein
A tool changer in which an annular groove is formed in the first step surface, and an O-ring that seals between the first step surface and the flange portion is provided in the annular groove.
The tool changer according to claim 1 or 2,
A master side air flow path is provided in the master block, and a tool side air flow path communicating with the master side air flow path is provided in the tool unit,
A cylindrical packing is attached to a packing mounting hole provided at one communicating end of the master-side air channel and the tool-side air channel,
A pressure contact portion having a diameter larger than the inner diameter of the packing mounting hole is provided in the packing,
A tool changer for supplying air to the tool from the master block side.
The tool changer according to any one of claims 1 to 3,
A tool changer in which a ball guide surface inclined so as to have a small diameter toward the ball engagement surface is provided on the abutting surface side of the engagement ring.
A master unit to which a tool unit with a tool attached is detachably mounted,
A mounting surface, a mounting surface facing the mounting surface, a small diameter hole opening in the mounting surface, a large diameter hole opening in the mounting surface and communicating with the small diameter hole, and the large diameter hole and the small diameter hole. A master block having a stepped surface formed therebetween;
A ball holder attached to the master block, comprising a cylindrical portion in which a plurality of balls are mounted and press-fitted into the small-diameter hole and a tip projects from the mounting surface, and a flange portion abutted against the step surface;
A piston having a ball driving portion provided at a tip thereof, incorporated in the large-diameter hole so as to be freely reciprocable in an axial direction, and forming a first pressurizing chamber with the step surface;
A head cover attached to the large-diameter hole and forming a second pressurizing chamber with the piston;
The piston moves to a first position that pushes the ball radially outward via the ball drive unit, and a second position that allows the ball to move radially,
A master unit that fixes the ball holder to the master block by press-fitting the cylindrical portion into the small-diameter hole.
The master unit according to claim 5,
When pressure is supplied to the second pressurizing chamber, the piston is driven to the first position, and when pressure is supplied to the first pressurizing chamber, the piston is driven to the second position. Master unit.
The master unit according to claim 5 or 6,
The master block is provided with a first positioning pin and a second positioning pin each having a fitting portion fitted in a fitting hole formed in each tool block of the tool unit,
The fitting portion in which the fitting portion and the fitting portion of the second positioning pin are fitted in a direction along a radial line intersecting the central axis of the piston and the central axis of the first positioning pin. A master unit with a gap between the holes.
The master unit according to claim 5 or 6,
A positioning pin provided with a fitting portion to be fitted in a fitting hole formed in each tool block of the tool unit is provided in the master block,
The fitting unit is a master unit having a tapered surface with a distal end surface thinner than a proximal end portion.
A tool unit to which a tool is attached and detachably attached to the master unit,
An abutting surface that abuts against the mounting surface of the master unit; a tip surface that faces the abutting surface and to which the tool is attached; an insertion hole that opens in the abutting surface; and an opening that opens in the tip surface and the insertion A tool block having an accommodation hole larger in diameter than the hole, and a step surface formed between the insertion hole and the accommodation hole;
An engagement ring that is press-fitted into the accommodation hole from the tip surface side and is abutted against the step surface;
A tapered ball engagement surface formed on the engagement ring,
A tool unit that fixes the engagement ring to the tool block by press-fitting the engagement ring into the accommodation hole.
The tool unit according to claim 9,
A tool unit, wherein a ball guide surface inclined so as to have a small diameter toward the ball engagement surface is provided on the abutting surface side of the engagement ring.
The tool unit according to claim 9 or 10,
Forming a fitting hole in the tool block for fitting a fitting portion of a first positioning pin and a second positioning pin provided in the master block of the master unit;
The fitting portion and the fitting portion of the second positioning pin in a direction along a radial line intersecting the central axis of the engagement ring and the central axis of the fitting hole of the first positioning pin are A tool unit in which a gap is formed between the fitting hole and the fitting hole.