Tool exchange device for robot

Abstract

To provide a compact tool exchange device for a robot.SOLUTION: A tool exchange device comprises a body part 5 on the robot arm 3 side, and a tool mounting part 6 detachably attached to the body part 5 via a coupling mechanism 7. The coupling mechanism 7 includes: a solenoid 12 which has a plunger 92 that moves to one end side by magnetic force from an electromagnet 91; a ball 105 which is pushed by the plunger 92 when it moves to the other end side, protrudes from a cylindrical wall 27 (housing), and becomes movable when the plunger 92 moves to the one end side; a permanent magnet 20 which holds the plunger 92 by moving it to the other end side when the electromagnet 91 is in a non-energized state; a hole 54 of the tool mounting part 6 to which the cylindrical wall 27 is inserted; and an engagement wall 55 of the tool mounting part 6 with which the ball 105 protruding from the cylindrical wall 27 engages.SELECTED DRAWING: Figure 13

Description

Technical Field

[0001] The present invention relates to a robot tool changer for detachably attaching a tool to a robot arm.

Background Art

[0002] Many industrial robots that use tools by exchanging them are equipped with a tool changer so that the tools can be easily exchanged. As a conventional tool changer of this type, for example, there is one described in Patent Document 1. The tool changer described in Patent Document 1 includes a device body attached to a robot arm, an adapter to which a tool is attached, and a connection mechanism that detachably connects the adapter to the device body.

[0003] The connection mechanism is configured to switch between connection and release of the device body and the adapter using a movable ball. The movement of the ball is performed using an air cylinder provided in the device body. The ball is accommodated in an annular groove formed in the piston rod of the air cylinder, and when the piston rod retracts, the ball moves to an engagement position on the outer side in the radial direction of the piston rod. The ball is movable between the engagement position and a retracted position on the inner side in the radial direction when the piston rod advances.

[0004] When the piston rod retracts and the ball moves to the engagement position, the adapter is connected to the device body. Also, when the piston rod advances, the engagement state of the ball is released and the adapter can be removed from the device body. The air cylinder is configured such that the piston rod advances by air pressure and the piston rod retracts by the spring force of a spring member. The spring member is constituted by a compression coil spring and is assembled to the air cylinder in a state where the piston rod penetrates therethrough.

Prior Art Documents

Patent Documents

[0005] Patent Document 1 Japanese Patent Application Laid-Open No. 59-175984 Summary of the Invention Problems to be Solved by the Invention

[0006] In the tool changer disclosed in Patent Document 1, in order to prevent the piston rod from advancing due to vibration or the like and releasing the engagement state of the ball when maintaining the state where the adapter is attached to the apparatus main body, it is necessary to use a spring member with a large spring force. When using a spring member with a large spring force, a large force is also required when advancing the piston rod, so the piston receiving pneumatic pressure must be increased in diameter.

[0007] Also, in this tool changer, since a space for accommodating a compression coil spring as a spring member is required around the piston rod, there is a limit to forming the air cylinder with a small diameter. For this reason, there has been a problem that it is difficult to further reduce the size of the tool changer shown in Patent Document 1.

[0008] An object of the present invention is to provide a robot tool changer with a reduced size. Means for Solving the Problems

[0009] The tool changing device for a robot according to the present invention includes a main body portion attached to a robot arm and a mounting seat to which a tool for the robot arm is attached, and a tool mounting portion detachably attached to the main body portion via a connection mechanism. The connection mechanism includes a solenoid having a structure in which a plunger moves to one end side by the magnetism of an electromagnet, a housing that houses the other end portion of the plunger, a ball that is held in the housing so as to be able to protrude and retract, and is pushed by the plunger and protrudes from the housing when the plunger moves to the other end side, and the pressing by the plunger is released when the plunger moves to the one end side, a hole formed in the tool mounting portion so as to be able to insert the housing, an engaging wall provided on the hole wall surface of the hole, which engages with the ball protruding from the housing to regulate the housing from coming out of the hole, and a permanent magnet that moves and holds the plunger to the other end side in a state where the electromagnet is non-excited.

[0010] The present invention is in the above-described tool changing device for a robot, the engaging wall has an inclined surface that contacts the ball, the inclined surface may be inclined so as to gradually face the opening edge of the hole as it approaches the center of the hole.

[0011] The present invention is in the above-described tool changing device for a robot, the electromagnet is formed in a cylindrical shape, the plunger includes an armature located on the same axis as the electromagnet, and the permanent magnet may be disposed at a position facing the armature.

[0012] The present invention is in the above-described tool changing device for a robot, the electromagnet is formed in a cylindrical shape, one end portion of the plunger is formed by a lock pin that penetrates the axial center portion of the electromagnet, and a manual release lever for moving the lock pin to the one end side may be connected to the tip end portion of the lock pin.

Advantages of the Invention

[0013] According to the present invention, it is possible to provide a tool changing device for a robot that has been miniaturized.

Brief Description of the Drawings

[0014]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Figure 16

Figure 17

Figure 18

Figure 19

Embodiments for Carrying Out the Invention

[0015] Hereinafter, an embodiment of a robot tool changer according to the present invention will be described in detail with reference to FIGS. 1 to 19. The robot tool changer 1 shown in FIGS. 1(A) and 1(B) is for detachably attaching a tool 4 for a robot arm to a robot arm 3 of an industrial robot 2. This robot tool changer 1 includes a main body portion 5 attached to the robot arm 3, a tool mounting portion 6 detachably attached to the main body portion 5 on the tool 4, and a connection mechanism 7 (see FIG. 1(B)) for switching the connection and disconnection between the main body portion 5 and the tool mounting portion 6. In the following, when indicating directions in explaining each component of the robot tool changer 1, the direction in which the main body portion 5 is located with respect to the tool mounting portion 6 is defined as the upward direction as shown in FIG. 1.

[0016] (Description of the main body portion) As shown in FIG. 3, the main body portion 5 is configured by assembling a plurality of functional components described later to a main body side frame 8. (Description of the first frame member) As shown in FIG. 4, the main body side frame 8 is composed of a first frame member 9 drawn on the upper side in FIG. 4 and a second frame member 10 attached to the lower surface of the first frame member 9. A first through hole 11 is formed in the central portion of the first frame member 9. This first through hole 11 is a hole for accommodating the electromagnetic portion of a solenoid 12 (see FIG. 6) described later, and is formed so that the opening shape is circular.

[0017] On the upper surface of the first frame member 9 and around the first through hole 11, a plurality of first screw holes 13, a plurality of second through holes 14, and one third through hole 15 are formed. The first screw holes 13 are for screwing in first fixing bolts 16 (see FIG. 7) for fixing the member stacked on the first frame member 9 to the first frame member 9. The members stacked on the first frame member 9 are the support plate 17 for the solenoid 12 and the mounting plate 18, which will be described later. The mounting plate 18 is connected to the robot arm 3.

[0018] The second through holes 14 are holes for passing fixing bolts (not shown) for fixing the main body portion 5 to the robot arm 3. These fixing bolts penetrate the main body portion 5 in the vertical direction and fix the entire main body portion 5 to the robot arm 3. The third through hole 15 is a guide hole for press-fitting a guide pin 19 (see FIG. 6) described later into the pin hole 17a of the support plate 17. The guide pin 19 is press-fitted into the pin hole 17a.

[0019] Horizontal holes 21 extending toward the first through hole 11 are open on the four side surfaces 9a of the first frame member 9. Also, air passage forming members 22, 23 and electrical component cases 24, 25 shown in FIG. 3 are attached to the four side surfaces 9a of the first frame member 9. In this embodiment, among the four side surfaces 9a of the first frame member 9, the air passage forming members 22, 23 are attached to two side surfaces 9a, 9a positioned so as to sandwich the first frame member 9, and the electrical component cases 24, 25 are attached to the other two side surfaces 9a, 9a. The description of the air passage forming members 22, 23 and the electrical component cases 24, 25 will be given later.

[0020] (Description of the second frame member) As shown in Fig. 4, the second frame member 10 is formed in a bottomed cylindrical shape that opens upward. The second frame member 10 is made of a non-magnetic material. A permanent magnet 20 is fixed to the inner bottom surface 10a of the second frame member 10 as shown in Fig. 6. This permanent magnet 20 constitutes a part of a connecting mechanism 7 to be described later and is formed in a ring shape. At the center of the bottom wall 10b of the second frame member 10, a cylindrical wall 27 that protrudes downward is formed. The lower surface of the second frame member 10 excluding the cylindrical wall 27 is formed to be a flat surface.

[0021] A plurality of circular through-holes 28 are formed in the cylindrical wall 27. The through-holes 28 are formed so as to penetrate the cylindrical wall 27 in the radial direction. In this embodiment, the through-holes 28 are formed at positions where the cylindrical wall 27 is divided into four equal parts in the circumferential direction. As shown in Fig. 10, a tapered surface 29 whose inner diameter gradually decreases toward the opening is formed at the portion of the through-hole 28 that opens to the outer peripheral surface 27a of the cylindrical wall 27.

[0022] As shown in Fig. 4, a plurality of fourth through-holes 31, a plurality of fifth through-holes 32, and sixth and seventh through-holes 33, 34 are formed in the outer peripheral portion of the second frame member 10. The fourth through-hole 31 is a hole for passing a second fixing bolt 35 that fixes the second frame member 10 to the first frame member 9 as shown in Fig. 7. The plurality of fifth through-holes 32 and the sixth through-hole 33 are holes for passing first and second positioning pins 36, 37 (see Fig. 8) that position the main body portion 5 and the tool attachment portion 6 when the main body portion 5 is attached to the tool attachment portion 6.

[0023] The first and second positioning pins 36, 37 penetrate the second frame member 10 in the vertical direction and protrude downward from the second frame member 10. The first positioning pin 36 is inserted into the fifth through-hole 32 and fixed to the first frame member 9 by a third fixing bolt 38. The second positioning pin 37 is press-fitted into the sixth through-hole 33. The seventh through-hole 34 is a hole for press-fitting an eighth positioning pin 39 (see FIG. 6) for positioning the second frame member 10 relative to the first frame member 9.

[0024] (Description of the tool attachment part) As shown in FIG. 3, the tool attachment part 6 is configured by assembling air passage forming members 42, 43 and electrical component cases 44, 45 to a tool attachment part side frame 41. As shown in FIG. 5, the tool attachment part side frame 41 is composed of a third frame member 46 drawn on the lower side in FIG. 5 and a fourth frame member 47 attached on the third frame member 46.

[0025] The third frame member 46 serves as a mounting seat for attaching the tool 4. A circular recess 48 opening upward is formed at the center of the third frame member 46. A plurality of second screw holes 49, a plurality of first pin holes 50, a plurality of eighth through-holes 51, etc. are formed around the circular recess 48 in the third frame member 46. As shown in FIG. 9, a fourth fixing bolt 52 for fixing the fourth frame member 47 to the third frame member 46 is screwed into the second screw hole 49. The fourth fixing bolt 52 is inserted through a ninth through-hole 53 formed in the fourth frame member 47 and screwed to the second screw hole 49.

[0026] The first pin hole 50 is a hole into which first and second positioning pins 36, 37 provided on the main body part 5 are fitted. The eighth through-hole 51 is a hole through which a bolt (not shown) for attaching a tool to the tool attachment part 6 passes.

[0027] Air passage forming members 42, 43 on the tool attachment part side and electrical component cases 44, 45 are attached to four side surfaces of the third frame member 46. In this embodiment, among the four side surfaces 46a of the third frame member 46, the air passage forming members 42, 43 are attached to two side surfaces 46a positioned so as to sandwich the third frame member 46, and the electrical component cases 44, 45 are attached to the other two side surfaces 46a. The air passage forming members 42 and 43 of the tool mounting portion 6 are arranged at positions vertically aligned with the air passage forming members 22 and 23 of the main body portion 5 in a state where the tool mounting portion 6 is attached to the main body portion 5. Further, the electrical component cases 44 and 45 of the tool mounting portion 6 are arranged at positions vertically aligned with the electrical component cases 24 and 25 of the main body portion 5 in a state where the tool mounting portion 6 is attached to the main body portion 5.

[0028] As shown in FIG. 5, the upper surface of the fourth frame member 47 is formed flat so as to be in surface contact with the lower surface of the second frame member 10 in a state where the tool mounting portion 6 is attached to the main body portion 5. A circular hole 54 is formed at the center of the fourth frame member 47. The circular hole 54 is formed so that the cylindrical wall 27 protruding from the second frame member 10 can be fitted therein. When the tool mounting portion 6 is attached to the main body portion 5, the cylindrical wall 27 is fitted into the circular hole 54.

[0029] As shown in FIG. 11, the upper opening edge portion of the circular hole 54 is formed by an engaging wall 55 having a mountain-shaped cross section provided on the hole wall surface of the hole 54 so as to protrude toward the center of the hole 54. The upper wall surface of the engaging wall 55 is formed by a convex curved surface 55a having an arc-shaped cross section protruding toward the inside of the hole 54. The lower wall surface of the engaging wall 55 is formed by an inclined surface 55b that inclines toward the opening edge of the hole 54 (upward) as it goes toward the center of the hole 54. The lower opening of the circular hole 54, that is, the portion below the engaging wall 55, is formed by a large-diameter hole 56 having a larger hole diameter than the upper opening portion.

[0030] As shown in FIG. 5, around the circular hole 54 in the fourth frame member 47, the above-described ninth through hole 53, tenth through hole 57, and a plurality of second pin holes 58 are formed. The tenth through hole 57 is a hole through which a bolt (not shown) for attaching the tool 4 to the tool attachment portion 6 passes. This bolt passes through the eighth through hole 51 of the third frame member 46 and the tenth through hole 57 of the fourth frame member 47.

[0031] The air passage forming members 22, 23, 42, 43 attached to the main body portion 5 and the tool attachment portion 6 are for supplying driving air to the tool 4. As shown in FIG. 12(A), in the air passage forming members 22, 23 of the main body portion 5, an upstream air passage 63 extending from a supply port 61 opening on the side surface to a connection port 62 opening on the lower surface is formed. An air hose (not shown) extending from the robot arm 3 is connected to the supply port 61, and air for driving the tool is supplied.

[0032] On the other hand, in the air passage forming members 42, 43 of the tool attachment portion 6, a downstream air passage 67 extending from a pin 64 protruding upward and a passage hole 65 opening at the tip of the pin 64 to an air outlet 66 opening on the side surface of the air passage forming members 42, 43 is formed. The pin 64 is fixed to the air passage forming members 42, 43 of the tool attachment portion 6 by a fifth fixing bolt 68. Further, as shown in FIG. 12(B), in a state where the tool attachment portion 6 is attached to the main body portion 5, the pin 64 is inserted into the connection port 62 of the main body portion 5 from below. An air hose (not shown) for supplying driving air to the tool 4 is connected to the air outlet 66.

[0033] Therefore, by attaching the tool mounting portion 6 to the main body portion 5, driving air is supplied to the tool 4 through an air supply system of air hose on the robot arm 3 side → air passages 63, 67 → air hose on the tool side. At the end faces of the air passage forming members 42, 43 of the tool mounting portion 6 that face the air passage forming members 22, 23 of the main body portion 5, a seal member 69 for preventing air leakage from the mating surfaces of the air passage forming members 22, 23 and the air passage forming members 42, 43 is mounted around the pin 64. Further, a seal member 70 for sealing between the pin 64 and the air passage forming members 22, 23, 42, 43 is mounted on the pin 64.

[0034] The electrical component cases 24, 25 of the main body portion 5 are for supporting the main body portion side cable connectors 71 to 73 (see FIGS. 2(A), (B), 6 and 8) and the main body portion side connectors 74 to 76 (see FIGS. 2(B) and 8). Note that FIGS. 6 and 8 are drawn with the wirings in the electrical component cases 24, 25, 44, 45 omitted. The main body portion side cable connectors 71 to 73 are for detachably connecting a power supply and control cable (not shown) extending from the robot arm 3, and are electrically connected to electrical components such as a solenoid 12 (described later) and the main body portion side connectors 74 to 76 within the main body portion 5. The electrical component cases 44, 45 of the tool mounting portion 6 are for supporting the tool mounting portion side cable connectors 77, 78 and the tool mounting portion side connectors 79 to 81.

[0035] The tool mounting portion side cable connectors 77, 78 are for detachably connecting a cable (not shown) connected to the tool 4, and are electrically connected to the tool mounting portion side connectors 79 to 81. The tool attachment part side connectors 79 to 81 are configured to be connected to the main body part side connectors 74 to 76 by attaching the tool attachment part 6 to the main body part 5. Therefore, by attaching the tool attachment part 6 to the main body part 5, the robot arm 3 and the tool 4 are electrically connected through a circuit of the power supply and control cables on the robot arm 3 side → the main body part side cable connectors 71 to 73 → the main body part side connectors 74 to 76 → the tool attachment part side connectors 79 to 81 → the tool attachment part side cable connectors 77, 78 → the cables on the tool 4 side.

[0036] (Description of the connection mechanism) As shown in FIG. 13, the connection mechanism 7 is configured to operate with the solenoid 12 housed in the main body part 5 as the main power source. The left side of the center line C in FIG. 13 is drawn in the state when the solenoid 12 is OFF (non-energized), and the right side of the center line C is drawn in the state when the solenoid 12 is ON. The solenoid 12 has a structure in which a plunger 92 is movably supported at the axial center of an electromagnet 91 formed in a cylindrical shape. The solenoid 12 according to this embodiment is configured such that the plunger 92 moves to one end side (upper side in FIG. 13) by the magnetism of the electromagnet 91.

[0037] One end side of the plunger 92 is formed by a cylindrical lock pin 92a, and the other end side is formed by a columnar body 92b having an outer diameter larger than that of the lock pin 92a. As shown in FIG. 6, a manual release lever 93 is connected to the tip of the lock pin 92a (the end of one end side of the plunger 92). The manual release lever 93 is operated by an operator (not shown) when manually releasing the connection by the connection mechanism 7. The manual release lever 93 according to this embodiment is formed in a plate shape extending in a direction orthogonal to the longitudinal direction (vertical direction) of the plunger 92 and is disposed above the solenoid 12 in a state of crossing the mounting plate 18 in the radial direction.

[0038] The mounting plate 18 is formed in a bottomed cylindrical shape that opens downward as shown in FIG. 7, and the outer peripheral portion is overlapped with the support plate 17 of the solenoid 12. A central hole 18b with a circular opening shape is formed at the center of the ceiling plate 18a. On the outer peripheral portion of the mounting plate 18, an 11th through-hole 94 through which the first fixing bolt 16 passes, a 12th through-hole 95 into which a guide pin 19 (see FIG. 6) fits, and a 13th through-hole 96 for passing a fixing bolt (not shown) for fixing the main body 5 to the robot arm 3 are formed. Further, a notch 97 (see FIGS. 3 and 6) for passing a manual release lever 93 is formed on the outer peripheral portion of the mounting plate 18.

[0039] The moving direction of the manual release lever 93 is restricted only in the vertical direction by the guide pin 19 passing through the mounting plate 18. The connection portion between the manual release lever 93 and the lock pin 92a has a structure in which the tip of the lock pin 92a is loosely inserted into a 14th stepped through-hole 98 formed in the manual release lever 93, and the manual release lever 93 is prevented from coming off by a bolt 99 screwed to the tip of the lock pin 92a. As shown in FIG. 13, the 14th stepped through-hole 98 has a stepped portion 98a formed on the other end side closer to the support plate 17 by making the hole diameter on one end side, which is the upper side in FIG. 13, larger than that on the other end side. The stepped portion 98a is formed to protrude inward in the radial direction. According to the retaining structure composed of the 14th stepped through-hole 98 and the bolt 99, only the lock pin 92a can be moved upward with the manual release lever 93 placed on the solenoid 12. Also, as shown in FIG. 19, by pulling up the manual release lever 93, the stepped portion 98a of the 14th stepped through-hole 98 abuts against the head 99a of the bolt 99, and the lock pin 92a is pulled up integrally with the manual release lever 93. When pulling up the manual release lever 93, the head 99a of the bolt 99 is inserted into the central hole 18b of the mounting plate 18.

[0040] As shown in FIG. 6, a stopper 100 is provided between a manual release lever 93 and a ceiling plate 18a of a mounting plate 18 to restrict the movement of the manual release lever 93 when the manual release lever 93 is not used. The stopper 100 has a slit 101 into which a guide pin 19 is inserted, and is sandwiched in a detachable state between the manual release lever 93 and the ceiling plate 18a of the mounting plate 18.

[0041] As shown in FIG. 14, a columnar body 92b located at the lower end of a plunger 92 is composed of a large-diameter portion 102 connected to a lock pin 92a and a small-diameter portion 103 connected to the lower end of the large-diameter portion 102. The large-diameter portion 102 is fitted into a cylindrical wall 27 of a second frame member 10 and is formed in a shape to be accommodated inside the cylindrical wall 27. In this embodiment, the cylindrical wall 27 corresponds to the "housing for accommodating the other end of the plunger" in the present invention.

[0042] The boundary between the large-diameter portion 102 and the small-diameter portion 103 is formed by a tapered surface 104 whose outer diameter gradually increases upward. The small-diameter portion 103 is formed so as to be adjacent to a through hole 28 of the cylindrical wall 27 in the radial direction of the cylindrical wall 27 in a state where the plunger 92 has moved upward with respect to the electromagnet 91 as shown on the right side of the center line C in FIG. 14. Balls 105 that form part of a connecting mechanism 7 are respectively accommodated in four through holes 28 of the cylindrical wall 27. The balls 105 can be accommodated in the through holes 28 in a state where the plunger 92 has moved upward as shown on the right side of the center line C in FIG. 14. Further, the balls 105 are pushed to the outside in the radial direction of the cylindrical wall 27 by the tapered surface 104 and the large-diameter portion 102 in a state where the plunger 92 has moved downward with respect to the electromagnet 91 as shown on the left side of the center line C in FIG. 14. In a state where the plunger 92 is at its lowest position, a part of the balls 105 protrudes outside the cylindrical wall 27. That is, the balls 105 are held in the cylindrical wall 27 so as to be able to protrude and retract.

[0043] At this time, the ball 105 is held in the through hole 28 in a state where it does not fall out of the through hole 28 by contacting the tapered surface 29 formed at the opening of the through hole 28. In the following, the position of the plunger 92 shown on the right side of FIG. 14, that is, the position of the plunger 92 where the small-diameter portion 103 is adjacent to the through hole 28 and the entire ball 105 can be accommodated in the through hole 28, is referred to as the "release position". Also, the position of the plunger 92 shown on the left side of FIG. 14, that is, the position of the plunger 92 where the ball 105 is pushed by the large-diameter portion 102 and protrudes outside the cylindrical wall 27, is referred to as the "lock position".

[0044] As shown in FIG. 13, in a state where the tool attachment portion 6 is attached to the main body portion 5, the through hole 28 and the ball 105 are positioned at the same position in the vertical direction as the large-diameter hole 56 of the fourth frame member 47. For this reason, when the plunger 92 moves to the lock position in this state, the ball 105 is inserted into the large-diameter hole 56 of the fourth frame member 47 as shown on the left side of the center line C in FIG. 13. In this locked state, since the ball 105 engages with the engaging wall 55, the tool attachment portion 6 cannot be removed from the main body portion 5.

[0045] When the plunger 92 moves from this locked state to the release position, as shown in FIG. 15(A), there is no longer anything pushing the ball 105 radially outward of the cylindrical wall 27. That is, in this state, the pressing of the ball 105 by the plunger 92 is released. When the main body portion 5 is moved in the direction away from the tool attachment portion 6 in this state as shown in FIG. 15(B), the ball 105 is pushed by the inclined surface 55b of the fourth frame member 47 and pushed into the inside of the cylindrical wall 27. Then, by further separating the main body portion 5 from the tool attachment portion 6, as shown in FIG. 15(C), the engagement state between the engaging wall 55 and the ball 105 is released, and the tool attachment portion 6 can be removed from the main body portion 5.

[0046] As shown in FIG. 16, a bottomed cylindrical armature 106 is fixed at the central portion in the axial direction of the plunger 92 in a state of being located on the same axis as the plunger 92. The armature 106 according to this embodiment includes an inner cylindrical portion 106a through which the lock pin 92a of the plunger 92 passes, a disk-shaped adsorption portion 106b extending radially outward from the lower end of the inner cylindrical portion 106a, and an outer cylindrical portion 106c extending upward from the outer peripheral portion of the adsorption portion 106b, and is formed to a size that can be accommodated inside the second frame member 10.

[0047] The permanent magnet 20 provided on the inner bottom of the second frame member 10 is arranged at a position facing the adsorption portion 106b of the armature 106 as shown in FIG. 14. For this reason, the magnetic force of the permanent magnet 20 acts on the armature 106 accommodated inside the second frame member 10. When no magnetic force other than the magnetic force of the permanent magnet 20 acts on the armature 106 (the state where the electromagnet 91 of the solenoid 12 is non-excited), as shown in FIG. 14, the armature 106 is adsorbed to the inner bottom surface 10a of the second frame member 10 by the magnetism of the permanent magnet 20. By adsorbing the armature 106 to the inner bottom surface 10a of the second frame member 10 in this way, the plunger 92 moves to the other end side (lower side in FIG. 14) and is held by the permanent magnet 20.

[0048] In the solenoid 12 according to this embodiment, when the armature 106 is adsorbed to the inner bottom surface 10a of the second frame member 10 by the magnetism of the permanent magnet 20, as drawn on the left side of the center line C in FIG. 14, the plunger 92 is positioned at the above-described lock position. In this state, the permanent magnet 20 magnetically holds the plunger 92 that has moved so that the ball 105 protrudes from the cylindrical wall 27.

[0049] As shown in FIG. 16, the electromagnet 91 includes a cylindrical field core 109 having an annular groove 108 for accommodating a cylindrical electromagnetic coil 107, and a support plate 17 extending radially outward from the upper end of the field core 109. An axial hole 110 extending in the vertical direction is formed at the axial center of the field core 109. The lock pin 92a of the plunger 92 is inserted into the axial hole 110 and is supported by a bearing member 111 provided at the upper end of the axial hole 110 so as to be movable in the vertical direction.

[0050] As shown in FIGS. 6 and 7, the support plate 17 is fixed to the first frame member 9 by a first fixing bolt 16 (see FIG. 7) and a guide pin 19 (see FIG. 6) while being sandwiched between the first frame member 9 and the mounting plate 18. The guide pin 19 is press-fitted into the pin hole 17a of the support plate 17 and is fitted into the third through hole 15 of the first frame member 9. The first fixing bolt 16 is passed through a fifteenth through hole 112 formed in the support plate 17 and is screwed into the first screw hole 13 of the first frame member 9. On the outer peripheral portion of the lower end side of the field core 109 according to this embodiment, a small-diameter portion 109a that is inserted inside the outer cylindrical portion 106c of the armature 106 is formed. A gap through which the magnetic flux of the electromagnetic coil 107 can pass is formed between the outer peripheral surface of the small-diameter portion 109a and the inner peripheral surface of the outer cylindrical portion 106c.

[0051] On the inner peripheral portion of the lower end of the field core 109, a circular hole 109b that opens downward is formed. This hole 109b is formed so that the inner cylindrical portion 106a of the armature 106 can be inserted. The inner peripheral surface of the hole 109b and the outer peripheral surface of the inner cylindrical portion 106a of the armature 106 are inclined so as to gradually move radially inward as they go upward. A gap through which the magnetic flux of the electromagnetic coil 107 can pass is formed between the inner peripheral surface of the hole 109b and the outer peripheral surface of the inner cylindrical portion 106a.

[0052] When the electromagnetic coil 107 of the electromagnet 91 is energized to excite the electromagnet 91, as shown by the dashed double-dotted line in Fig. 16, magnetic flux flows through the field core 109 and the armature 106, and a magnetic attraction force acts on the armature 106 in the direction of pulling it upward. The electromagnet 91 generates a magnetic attraction force such that the armature 106 adsorbed to the third frame member 46 by the magnetism of the permanent magnet 20 is pulled upward against the magnetic attraction force of the permanent magnet 20. Therefore, when the electromagnet 91 is excited, as shown on the right side of the center line C in Fig. 16, the armature 106 is magnetically adsorbed to the field core 109. In the solenoid 12 according to this embodiment, when the armature 106 is magnetically adsorbed to the field core 109, the plunger 92 is positioned at the release position, as shown on the right side of the center line C in Fig. 13.

[0053] (Operation Explanation) In order to attach the tool 4 to the robot arm 3 using the robot tool changer 1 configured as described above, first, as shown in Fig. 17(A), the solenoid 12 of the main body 5 is energized to move the plunger 92 to the release position. Then, the robot arm 3 is operated to bring the main body 5 close to the tool mounting portion 6, and as shown in Fig. 17(B), the cylindrical wall 27 of the main body 5 is inserted into the hole 54 of the tool mounting portion 6. At this time, if the ball 105 protrudes outside the cylindrical wall 27, the ball 105 is pushed into the cylindrical wall 27 by contacting the convex curved surface 55a of the engaging wall 55.

[0054] Next, with the cylindrical wall 27 inserted into the hole 54 and the second frame member 10 overlapping the fourth frame member 47, the power supply to the solenoid 12 is cut off. When the solenoid 12 loses its magnetic force, the armature 106 is pulled toward the inner bottom surface 10a side of the second frame member 10 by the magnetic attraction force of the permanent magnet 20. Then, as shown in Fig. 17(C), the armature 106 is adsorbed to the second frame member 10 by the magnetic attraction force of the permanent magnet 20. As a result, the plunger 92 moves to the other end side and is held by the permanent magnet 20.

[0055] At this time, the columnar body 92b of the plunger 92 moves downward within the cylindrical wall 27, and along with this movement, the ball 105 is pushed by the columnar body 92b and protrudes outside the cylindrical wall 27. This ball 105 is inserted into the large-diameter hole 56 of the fourth frame member 47. By inserting the ball 105 into the large-diameter hole 56 in this way, the ball 105 engages with the engaging wall 55, and the main body 5 cannot be removed upward from the tool attachment portion 6. The operation using the tool 4 is thus carried out in a locked state where the main body 5 and the tool attachment portion 6 are integrated.

[0056] When removing the tool 4 from the tool attachment portion 6, the robot arm 3 is operated to place the tool attachment portion 6 on a support base (not shown), and in that state, the solenoid 12 is energized. When the solenoid 12 is energized, the magnetic attraction force of the electromagnet 91 acts on the armature 106, and the armature 106 is magnetically attracted to the field core 109 against the magnetic attraction force of the permanent magnet 20. When the armature 106 is attracted to the field core 109, as shown in Fig. 15(A), the columnar body 92b of the plunger 92 rises within the cylindrical wall 27, and the ball 105 becomes movable. Then, the robot arm 3 is operated to raise the main body 5. When the main body 5 moves upward with respect to the tool attachment portion 6, as shown in Fig. 15(B), the ball 105 is pressed against the inclined surface 55b of the engaging wall 55 and pushed into the cylindrical wall 27, and the engagement state between the ball 105 and the engaging wall 55 is released. Therefore, by raising the main body 5 with the solenoid 12 in the ON state, as shown in Fig. 15(C), the main body 5 is removed upward from the tool attachment portion 6.

[0057] (Explanation of manual disconnection) In the robot tool changer 1 according to this embodiment, the operation of removing the main body 5 from the tool mounting portion 6 can be manually performed without energizing the solenoid 12. To manually remove the main body 5 from the tool mounting portion 6, first, as shown in FIG. 18, the stopper 100 is removed, and as depicted on the right side of the center line C in FIG. 19, the manual release lever 93 is pulled upward with respect to the solenoid 12. By operating the lever 93 in this manner, the plunger 92 moves upward together with the lever 93, and the small-diameter portion 103 of the columnar body 92b comes adjacent to the ball 105 so that the ball 105 can move freely. By moving the main body 5 upward with respect to the tool mounting portion 6 in this state, the main body 5 can be removed from the tool mounting portion 6 as shown in FIG. 15(C).

[0058] Also, in a state where the manual release lever 93 is operated to move the plunger 92 so that the armature 106 contacts the field core 109, the main body 5 can be attached to the tool mounting portion 6 without energizing the solenoid 12. That is, according to this robot tool changer 1, the main body 5 can be manually removed from the tool mounting portion 6 or the main body 5 can be manually attached to the tool mounting portion 6.

[0059] (Description of the effects according to the embodiment) The robot tool changer 1 according to this embodiment is configured such that the main body 5 is held in a locked state attached to the tool mounting portion 6 by the magnetic attraction force of the permanent magnet 20. Therefore, compared with the case of using a compression coil spring to maintain the locked state, the structure for maintaining the locked state can be miniaturized. Therefore, according to this embodiment, a robot tool changer with a reduced size can be provided.

[0060] The engaging wall 55 of the fourth frame member 47 according to this embodiment has an inclined surface 55b that contacts the ball 105. The inclined surface 55b is inclined so as to gradually face the opening edge of the hole 54 as it approaches the center of the hole 54 of the fourth frame member 47. For this reason, when removing the main body portion 5 from the tool attachment portion 6, the ball 105 can be pushed by the inclined surface 55b and pushed into the cylindrical wall 27, so that no special operation is required to release the locked state.

[0061] The electromagnet 91 according to this embodiment is formed in a cylindrical shape. The plunger 92 includes an armature 106 located on the same axis as the electromagnet 91. The permanent magnet 20 is disposed at a position facing the armature 106. For this reason, the direction in which the armature 106 can move is parallel to the direction in which the armature 106 is attracted by the magnetic attraction force of the permanent magnet 20, so that the plunger 92 can be reliably held in the locked position by efficiently using the magnetic attraction force of the permanent magnet 20.

[0062] One end portion of the plunger 92 according to this embodiment is formed by a lock pin 92a that penetrates the axial center portion of the cylindrical electromagnet 91. A manual release lever 93 for moving the lock pin 92a to one end side is connected to the tip of the lock pin 92a. For this reason, by operating the manual release lever 93, the locked state and the released state can be manually switched without energizing the solenoid 12.

[0063] The robot tool changer 1 according to the above-described embodiment is configured such that air passage forming members 22 and 23 are provided in the main body portion 5 and air passage forming members 42 and 43 are provided in the tool attachment portion 6, and an air-driven tool 4 can be used. However, when an electric tool 4 is used, it is not necessary to provide the air passage forming members 22, 23, 42, and 43. In this case, since no air piping is required for the robot tool changer 1 or the robot side, the structure can be simplified.

Description of Reference Numerals

[0064] 1...Tool changer for robot, 3...Robot arm, 4...Tool, 5...Main body, 6...Tool mounting part, 7...Linking mechanism, 12...Solenoid, 20...Permanent magnet, 27...Cylindrical wall (housing), 46...Third frame member (mounting seat), 54...Hole, 55...Engaging wall, 55b...Inclined surface, 91...Electromagnet, 92...Plunger, 92a...Lock pin, 93...Lever for manual release, 105...Ball, 106...Armature.

Claims

1. A main body portion attached to a robot arm, and a tool attachment portion having an attachment seat for a tool for the robot arm and detachably attached to the main body portion via a connection mechanism, wherein the connection mechanism includes a solenoid having a structure in which a plunger moves to one end side by the magnetism of an electromagnet, a housing that houses the other end portion of the plunger, a ball that is held in the housing so as to be able to protrude and retract, and is pushed by the plunger and protrudes from the housing when the plunger moves to the other end side, and the pressing by the plunger is released when the plunger moves to the one end side, a hole provided in the tool attachment portion and formed so as to be able to insert the housing, an engaging wall provided on the hole wall surface of the hole, engaging with the ball protruding from the housing, and restricting the housing from coming out of the hole, and a permanent magnet that moves and holds the plunger to the other end side in a state where the electromagnet is non-excited. A tool changing device for a robot characterized by comprising.

2. In the tool changing device for a robot according to claim 1, the engaging wall has an inclined surface in contact with the ball, and the inclined surface is inclined so as to gradually face the opening edge of the hole toward the center of the hole. A tool changing device for a robot characterized by this.

3. In the tool changing device for a robot according to claim 1, the electromagnet is formed in a cylindrical shape, the plunger includes an armature located on the same axis as the electromagnet, and the permanent magnet is disposed at a position facing the armature. A tool changing device for a robot characterized by this.

4. In the tool changing device for a robot according to claim 1, the electromagnet is formed in a cylindrical shape, one end portion of the plunger is formed by a lock pin penetrating the axial center portion of the electromagnet, and a manual release lever for moving the lock pin to the one end side is connected to the tip portion of the lock pin. A tool changing device for a robot characterized by this.

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