Robot tool changing device

Abstract

Robot tool changing device with a main body section attached to a robot arm; and a tool mounting section with a mounting seat to which a tool for the robot arm is attached, and which is detachably attached to the main body section, where the main body section includes: a solenoid containing an electromagnet and a piston configured to move towards the robot arm by a magnetic force of the electromagnet, the piston having a first section on one side of the robot arm and a second section on one side of the tool mounting section; a housing configured to accommodate the second section of the piston; a ball retractably held by the housing, wherein the ball is configured such that, when the piston moves towards the tool mounting section, it is pushed by the piston and protrudes from the housing, and the pushing by the piston ceases when the piston moves towards the robot arm; and a permanent magnet configured to move the piston towards the tool mounting section and to hold the piston when the electromagnet is not activated, The tool mounting section includes: a frame element in which a hole for receiving the housing is formed, and the frame element has an engagement wall which is provided on a wall surface of the hole and is configured to engage with the ball protruding from the housing and to prevent the housing from coming loose from the hole.

Description

Background of the invention

[0001] The present invention relates to a robot tool changing device that replaceably attaches a tool to a robot arm.

[0002] Many industrial robots that exchange and use tools include tool changing devices so that the tools can be easily exchanged. For example, a conventional tool changing device of this type is disclosed in Japanese Patent Publication No. 59-175984 (Reference 1). The tool changing device disclosed in Reference 1 includes a device main body attached to a robot arm, an adapter to which a tool is attached, and a linking mechanism that detachably connects the adapter to the device main body.

[0003] The connection mechanism uses a configuration that alternates between connection and release between the device main body and the adapter using a movable ball. The ball is moved by an air cylinder located in the main body of the device. The ball is supported in an annular groove in the piston rod of the air cylinder. When the piston rod retracts, the ball moves to an engaged position located outward in the radial direction of the piston rod. When the piston rod advances, the ball can move freely between the engaged position and a retracted position located inward in the radial direction.

[0004] When the piston rod retracts and the ball moves into the engaged position, the adapter is connected to the device's main body. When the piston rod advances, the ball's engagement state is released, and the adapter can be detached from the device's main body.

[0005] The air cylinder is configured so that the piston rod is advanced by air pressure and retracted by the spring force of a spring element. The spring element is formed by a coil compression spring and is mounted on the air cylinder in a state where the piston rod extends through it.

[0006] In the tool changing device disclosed in Reference 1, in order to maintain a state where the adapter is fixed to the main body of the device, a spring element with a large spring force must be used to prevent the piston rod from being advanced due to vibration or the like, thus breaking the engagement state of the ball. When a spring element with a large spring force is used, a large force is required to move the piston rod, and the piston that receives the air pressure must have a large diameter.

[0007] Since this tool changing device requires a space to be formed around the piston rod for the coil of the compression spring, which serves as a spring element, the reduction in the diameter of the air cylinder is limited.

[0008] Therefore, in the tool changing device disclosed in Reference 1, it is difficult to further reduce its size. Summary of the invention

[0009] It is an object of the present invention to provide a robot tool changing device with a smaller size.

[0010] To achieve the above object of the present invention, a robot tool changing device is provided, comprising a main body portion attached to a robot arm, and a tool mounting portion including a mounting seat to which a tool for the robot arm is attached, and detachably attached to the main body portion, wherein the main body portion includes a solenoid including an electromagnet, and a piston configured to move toward the robot arm by a magnetic force of the electromagnet, the piston comprising a first portion on a side of the robot arm and a second portion on a side of the tool mounting portion, a housing configured to receive the second portion of the piston, a ball retractably held by the housing, the ball configured to,when the piston moves toward the tool attachment portion, it is pushed by the piston and protrudes from the housing, and wherein the pushing by the piston is stopped when the piston moves toward the robot arm, and a permanent magnet configured to move the piston toward the tool attachment portion and hold the piston when the electromagnet is not activated, the tool attachment portion includes a frame member in which a hole is formed for receiving the housing, and the frame member includes an engagement wall provided on a wall surface of the hole and configured to engage the ball protruding from the housing and prevent the housing from disengaging from the hole. Brief description of the drawings Fig. 1A is a front view showing a connected state of a robot tool changing device according to the embodiment. Fig. 1B is a front view showing a released state of the robot tool changing device according to this embodiment. Fig. 2A and Fig. 2B are perspective views of the robot tool changing device according to the embodiment. Fig. 3 is an exploded perspective view of accessories of the robot tool changing device according to the embodiment. Fig. 4 is a partially cutaway perspective view showing first and second frame members. Fig. 5 is a partially cutaway perspective view showing the third and fourth frame members. Fig. 6 is a perspective sectional view of a main body portion and a tool attachment portion. Fig. 7 is a perspective sectional view of the main body section. Fig. 8 is a perspective sectional view of the main body section. Fig. 9 is a perspective sectional view of the tool mounting portion. Fig. 10 is a sectional view showing a part of a tubular wall in an enlarged state. Fig. 11 is a sectional view showing a part of a fourth frame member in an enlarged state. Fig. 12A is a sectional view showing an air passage forming member before the tool attachment portion is attached to the main body portion. Fig. 12B is a sectional view showing the air passage forming member in a state where the tool attachment portion is attached to the main body portion. Fig. 13 is a sectional view of the main body portion and the tool attachment portion. Fig. is a sectional view showing the main parts in an enlarged state. Fig. 15A to 15C are sectional views showing a part of a link mechanism in an enlarged state. Fig. 16 is a sectional view of a solenoid. Fig. 17A to 17C are sectional views for explaining the operation of the link mechanism. Fig. 18 is a perspective view of the robot tool changer without the mounting plate and stop. Fig. 19 is a sectional view of the main body portion and the tool attachment portion for explaining the operation of a manual release lever. Description of the preferred embodiment

[0011] A robot tool changing device according to an embodiment of the present invention will now be described with reference to Fig. 1 to 19 described in detail.

[0012] One in the Fig. 1A and Fig. The robot tool changing device 1 shown in Figure 1B is used to replaceably attach a robot arm tool 4 to a robot arm 3 of an industrial robot 2. The robot tool changing device 1 comprises a main body portion 5, which is attached to the robot arm 3, and a tool attachment portion 6, which is attached to the tool 4 so that it can be removed from the main body portion 5. In this embodiment, a linking mechanism 7 (see Fig. 1B) configured to switch between connection and separation of the main body portion 5 and the tool attachment portion 6.

[0013] Hereinafter, when specifying a direction in a description of each component of the robot tool changing device 1, the direction in which the main body portion 5 is arranged with respect to the tool fixing portion 6 is defined as “upper side”, and a reverse direction is defined as “lower side”, as shown in the Fig. 1A and Fig. 1B. The upper side is sometimes referred to as "one end side" or "a direction toward the robot arm 3," and the lower side is sometimes referred to as "the other end side" or "a direction toward the tool attachment portion 6." Main body section

[0014] As in Fig. 3, the main body portion 5 is formed by assembling a plurality of functional parts (described later below) into a main body portion side frame 8. First frame element

[0015] As in Fig. 4, the main body section side frame 8 comprises a first frame member 9 which is Fig. 4 is shown on the top side, and a second frame member 10 which is fixed to the bottom side of the first frame member 9. A first through-hole 11 is formed in the center of the first frame member 9. The first through-hole 11 is a hole configured to receive the electromagnet of a solenoid 12 (see Fig. 6) and is shaped to have a circular opening.

[0016] A plurality of first screw holes 13, a plurality of second through holes 14, and a third through hole 15 are formed around the first through hole 11 in the upper surface of the first frame member 9. In each first screw hole 13, a first fastening bolt 16 (see Fig. 7), which fastens the elements resting on the first frame element 9 to the first frame element 9. The elements placed on the first frame element 9 are a support plate 17 of the solenoid 12 (described later) and a mounting plate 18. The mounting plate 18 is connected to the robot arm 3.

[0017] The second through-hole 14 is a hole configured to pass a fastening bolt (not shown) that secures the main body portion 5 to the robot arm 3. The fastening bolt extends through the main body portion 5 in the vertical direction and fixes the entire main body portion 5 to the robot arm 3.

[0018] The third through hole 15 is a guide hole used for pressing in a guide pin 19 to be described later (see Fig. 6) into a pin hole 17a of the support plate 17. The guide pin 19 is pressed into the pin hole 17a.

[0019] Lateral holes 21, which extend in the direction of the first through-hole 11, open to four side surfaces 9a of the first frame element 9. In addition, the Fig. 3, the air passage forming members 22 and 23 and the electronic component housings 24 and 25 are fixed to the four side surfaces 9a of the first frame member 9. In this embodiment, of the four side surfaces 9a of the first frame member 9, the air passage forming members 22 and 23 are fixed to two side surfaces 9a arranged to enclose the first frame member 9, and the electronic component housings 24 and 25 are fixed to the remaining two side surfaces 9a. The air passage forming members 22 and 23 and the electronic component housings 24 and 25 will be described later. Second frame element

[0020] As in Fig. 4, the second frame element 10 has a cylindrical shape with a bottom that opens upwards. The second frame element 10 is made of a non-magnetic material. As shown in Fig. As shown in Figure 6, a permanent magnet 20 is fixed to an inner bottom surface 10a of the second frame member 10. The permanent magnet 20 forms part of the connecting mechanism 7, which will be described later, and is annular.

[0021] A cylindrical tubular wall 27 projecting downward is formed in the center of a lower wall 10b of the second frame member 10. The lower surface of the second frame member 10, except for the tubular wall 27, is formed as a flat surface.

[0022] A plurality of circular through-holes 28 are formed in the tubular wall 27. The through-hole 28 is formed to extend radially through the tubular wall 27. In other words, the through-hole 28 extends between an inner peripheral surface 27a of the tubular wall 27 (an outer peripheral surface facing a columnar body 92b of a piston 92 to be described later) and an outer peripheral surface 27b of the tubular wall 27 (a peripheral surface facing a fourth frame member 47 to be described later). As shown in Fig. As shown in FIG. 10, a tapered surface 29, whose inner diameter gradually decreases toward the opening of the outer peripheral surface 27b, is formed at a portion of the through-hole 28 opening toward the outer peripheral surface 27b of the tubular wall 27. In this embodiment, four through-holes 28 are formed at positions that evenly divide the tubular wall 27 into four parts.

[0023] As in Fig. 4, a plurality of fourth through holes 31, a plurality of fifth through holes 32, a sixth through hole 33, and a seventh through hole 34 are formed in the outer peripheral portion of the second frame member 10. As shown in Fig. 7, the fourth through hole 31 is a hole configured for the passage of a second fastening bolt 35 that fixes the second frame member 10 to the first frame member 9.

[0024] The plurality of fifth through-holes 32 and the sixth through-hole 33 are holes configured to allow first positioning pins 36 and a second positioning pin 37 to pass through (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. The first positioning pins 36 and the second positioning pin 37 extend through 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 fastened to the first frame member 9 with a third fastening bolt 38. The second positioning pin 37 is pressed into the sixth through-hole 33.

[0025] The seventh through hole 34 is a hole into which an eighth positioning pin 39 (see Fig. 6), which is configured to position the second frame element 10 with respect to the first frame element 9, is pressed in. Tool mounting section

[0026] As in Fig. 3, the tool attachment section 6 is formed by assembling air passage forming members 42 and 43 and electronic component housings 44 and 45 on a tool attachment section side frame 41. As shown in Fig. 5, the tool attachment section side frame 41 comprises a third frame element 46 which is Fig. 5 is shown on the underside, and a fourth frame element 47 which is attached to the third frame element 46.

[0027] The third frame member 46 serves as a mounting seat to which the tool 4 is attached. A circular concave portion 48 is formed in the center of the third frame member 46, opening upward. A plurality of second screw holes 49, a plurality of first pin holes 50, and a plurality of eighth through holes 51 are formed around the circular concave portion 48 of the third frame member 46. As shown in Fig. 9, a fourth fastening bolt 52 configured to fasten the fourth frame member 47 to the third frame member 46 is screwed into the second screw hole 49. The fourth fastening bolt 52 is inserted into a ninth through hole 53 formed in the fourth frame member 47 and threadably engaged with the second screw hole 49.

[0028] The first pin holes 50 are holes into which the first positioning pins 36 and the second positioning pin 37 provided in the main body portion 5 are inserted. The eighth through hole 51 is a hole for passing a bolt (not shown) used to attach a tool to the tool attachment portion 6.

[0029] Air passage forming members 42 and 43 and electronic component housings 44 and 45 are fixed to the four side surfaces of the third frame member 46. In this embodiment, of the four side surfaces 46a of the third frame member 46, the air passage forming members 42 and 43 are fixed to two side surfaces 46a arranged to enclose the third frame member 46, and the electronic component housings 44 and 45 are fixed to the remaining two side surfaces 46a.

[0030] The air passage moldings 42 and 43 of the tool mounting portion 6 are arranged at positions where they are vertically aligned with the air passage moldings 22 and 23 of the main body portion 5 when the tool mounting portion 6 is mounted to the main body portion 5. Furthermore, the electronic component housings 44 and 45 of the tool mounting portion 6 are arranged at positions where they are vertically aligned with the electronic component housings 24 and 25 of the main body portion 5 when the tool mounting portion 6 is mounted to the main body portion 5.

[0031] As in Fig. 5, the upper surface of the fourth frame member 47 is formed flat so that it comes into surface contact with the lower surface of the second frame member 10 in a state in which the tool attachment portion 6 is attached to the main body portion 5.

[0032] A circular hole 54 is formed in the center of the fourth frame member 47. The circular hole 54 is shaped so that the tubular wall 27 protruding from the second frame member 10 can be fitted therein. When attaching the tool attachment portion 6 to the main body portion 5, the tubular wall 27 is fitted into the circular hole 54.

[0033] As in Fig. 11, the opening edge portion of the circular hole 54 on the upper side is formed by an engaging wall 55 having a mountain-shaped portion and provided on the wall surface of the hole 54 so as to protrude in the radial direction toward the center of the hole 54. The wall surface of the engaging wall 55 on the upper side is formed by a convex curved surface 55a having an arcuate cross section and protruding toward the inside of the hole 54. The wall surface of the engaging wall 55 on the lower side is formed by an inclined surface 55b gradually inclining toward the center (radial center) of the hole 54 in the radial direction toward the opening edge of the hole 54 (upward). The opening portion of the circular hole 54 on the lower side, i.e.a portion on the underside of the engaging wall 55, is formed by a large diameter hole 56 having a larger hole diameter than the opening portion on the top side.

[0034] As in Fig. 5, the above-described ninth through-holes 53, tenth through-holes 57, and a plurality of second pin holes 58 are formed around the circular hole 54 in the fourth frame member 47. The tenth through-hole 57 is a hole for passing a bolt (not shown) used to fix the tool 4 to the tool mounting portion 6. The bolt is passed through the eighth through-hole 51 of the third frame member 46 and the tenth through-hole 57 of the fourth frame member 47.

[0035] The air passage forming elements 22, 23, 42 and 43 attached to the main body section 5 and the tool attachment section 6 supply drive air to the tool 4. As shown in Fig. As shown in Fig. 12A, an upstream air passage 63 is formed in each of the air passage forming members 22 and 23 of the main body portion 5, extending from a supply port 61 opening toward a side surface to a connection port 62 opening toward the bottom surface. An air hose (not shown) extending from the robot arm 3 is connected to the supply port 61, and the tool is supplied with driving air.

[0036] On the other hand, in each of the air passage forming members 42 and 43 of the tool mounting portion 6, an upwardly projecting pin 64 and a downstream air passage 67 are formed, which extends from a passage hole 65 opening to the distal end of the pin 64 to an air outlet 66 opening to a side surface of the air passage forming member 42 or 43. The pin 64 is fixed to each of the air passage forming members 42 and 43 of the tool mounting portion 6 by a fifth fixing screw 68. As shown in Fig. As shown in Fig. 12B, the pin 64 is inserted from the bottom into the connection hole 62 of the main body portion 5 in a state where the tool attachment portion 6 is attached to the main body portion 5. An air hose (not shown) configured to supply driving air to the tool 4 is connected to the air outlet 66.

[0037] For this reason, when the tool mounting portion 6 is mounted on the main body portion 5, the driving air is supplied to the tool 4 through an air supply system of the air hose on the robot arm 3 side → the air passages 63 and 67 → the air hose on the tool side. On each of the end surfaces of the air passage forming members 42 and 43 of the tool mounting portion 6 facing the air passage forming members 22 and 23 of the main body portion 5, a sealing member 69 is mounted around each pin 64, which is configured to prevent air from escaping from the mating surfaces between the air passage forming members 22 and 23 and the air passage forming members 42 and 43. In addition, a sealing element 70 is attached to each pin 64 and is configured to provide a seal between the air passage forming elements 22, 23, 42 and 43.

[0038] The electronics housings 24 and 25 of the main body section 5 carry main body-side cable connections 71 to 73 (see Fig. 2A, Fig. 2B, Fig. 6 and Fig. 8) and main body connectors 74 to 76 (see Fig. 2B and Fig. 8). It should be noted that in the Fig. 6 and Fig. 8 the wiring in the housings of the electronic components 24, 25, 44 and 45 is not shown.

[0039] Feed / control cables (not shown) extending from the robot arm 3 are detachably connected to the main body section side cable connectors 71 to 73, and the main body section side cable connectors 71 to 73 are electrically connected to electronic components such as the solenoid 12 (described later) and the side connectors 74 to 76 of the main body section 5. The electronics housings 44 and 45 of the tool mounting section 6 support the tool mounting section side cable connectors 77 and 78 and the tool mounting section side connectors 79 to 81. Cables (not shown) connected to the tool 4 are detachably connected to the tool attachment section side cable connectors 77 and 78, and the tool attachment section side cable connectors 77 and 78 are electrically connected to the tool attachment section side connectors 79 to 81.The tool attachment section side connectors 79 to 81 are configured to be connected to the main body section side connectors 74 to 76 by attaching the tool attachment section 6 to the main body section 5.

[0040] Therefore, when the tool attachment section 6 is attached to the main body section 5, the robot arm 3 and the tool 4 are electrically connected via a circuit formed by the supply / control cables on the robot arm 3 side → the main body section-side cable connections 71 to 73 → the main body section-side terminals 74 to 76 → the tool attachment section-side terminals 79 to 81 → the tool attachment section-side cable connections 77 and 78 → the cables on the tool 4 side. Connection mechanism

[0041] As in Fig. As shown in Fig. 13, the link mechanism 7 is configured to use the solenoid 12 housed in the main body portion 5 as a main power source. A state in which the solenoid 12 is OFF (not activated) is shown on the left side of a center line C in Fig. Fig. 13, and a state in which the solenoid 12 is ON is shown on the right side of the center line C.

[0042] The solenoid 12 has a structure in which the piston 92 is movably supported in the axial center of a cylindrically shaped electromagnet 91. The solenoid 12 according to this embodiment is configured so that the piston 92 is moved to one end portion (the top side in Fig. 13), ie in the direction of the robot arm 3.

[0043] One end side / end portion of the piston 92 (a first end portion on the side of the robot arm 3) is formed by a columnar locking pin 92a, and the other end side of the piston 92 (a second end portion on the side of the tool attachment portion 6) is formed by a columnar body 92b whose outer diameter is larger than the locking pin 92a. A lever for manual unlocking is connected to the distal end portion of the locking pin 92a (the end portion on one end side of the piston 92), as shown in Fig. 6. The manual release lever 93 is operated by an operator (not shown) to manually release the connection of the link mechanism 7. The manual release lever 93 in this embodiment is plate-shaped and extends in a direction orthogonal to the longitudinal direction (vertical direction) of the piston 92 and is arranged on the solenoid 12, crossing the mounting plate 18 in the radial direction.

[0044] As in Fig. As shown in Fig. 7, the fixing plate 18 has a cylindrical shape with a bottom opening downward, and its outer peripheral portion rests on the support plate 17 of the solenoid 12. A central hole 18b with a circular opening is formed in the center of a sealing plate 18a. In the outer peripheral portion of the fixing plate 18, there are 11 through holes 94, each formed for passing through the first fixing bolt 16, and a 12 through hole 95 into which the guide pin 19 (see Fig. 6) is fitted, and 13 through holes 96, each designed to pass a fastening bolt (not shown) that fixes the main body section 5 to the robot arm 3. In addition, a recess 97 (see Fig. 3 and Fig. 6) which serves to guide the lever for manual unlocking 93.

[0045] The moving direction of the manual release lever 93 is limited only to the vertical direction by the guide pin 19 extending through the fixing plate 18. The connecting portion between the manual release lever 93 and the locking pin 92a has a structure in which the distal end portion of the locking pin 92a is inserted in a loosely fitted state into a stepped through hole 98 formed in the manual release lever 93, and the manual release lever 93 is locked by a bolt 99 threadedly engaged with the distal end of the locking pin 92a. Note that the bolt 99 constitutes a coupling member connected to the distal end portion of the locking pin 92a.

[0046] As in Fig. 13, in the 14 stepped through hole 98, the hole diameter at one end side, which is in Fig. 13, the top side is larger than that on the other end side, thereby forming a stepped portion 98a on the other end side near the support plate 17. The stepped portion 98a is formed to protrude inward in the radial direction. The hole diameter (inner diameter) of the 14th stepped through-hole 98 is larger than the outer diameter of the locking pin 92a. The outer diameter of the head portion of the bolt 99 is larger than the hole diameter of the stepped portion 98a and smaller than the hole diameter on the top side of the stepped portion 98a of the 14th stepped through-hole 98.

[0047] According to the locking structure formed by the 14th stepped through-hole 98 and the bolt 99, in a state where the manual release lever 93 is disposed on the solenoid 12, only the locking pin 92a can be moved upward (that is, toward the robot arm 3). When the manual release lever 93 is pulled upward, the step portion 98a of the 14th stepped through-hole 98 abuts against a head portion 99a of the bolt 99, and the locking pin 92a is pulled upward together with the manual release lever 93. When the manual release lever 93 is pulled up, the head portion 99a of the bolt 99 is inserted into the center hole 18b of the fixing plate 18.

[0048] As in Fig. As shown in Figure 6, a stopper 100 is provided between the manual release lever 93 and the sealing plate 18a of the mounting plate 18 to prevent movement of the manual release lever 93 when the manual release lever 93 is not in use. The stopper 100 includes a slot 101 into which the guide pin 19 is inserted and is releasably clamped between the manual release lever 93 and the sealing plate 18a of the mounting plate 18.

[0049] As in Fig. As shown in Figure 14, the columnar body 92b located at the lower end portion of the piston 92 includes a large-diameter portion 102 connected to the locking pin 92a and a small-diameter portion 103 connected to the lower end portion of the large-diameter portion 102. The large-diameter portion 102 is shaped to fit into the tubular wall 27 of the second frame member 10 and is supported in the tubular wall 27. The tubular wall 27 forms a housing in which the columnar body 92b of the piston 92 is housed.

[0050] The small-diameter portion 103 has an outer diameter smaller than the outer diameter of the large-diameter portion 102. A tapered surface 104 is formed between the large-diameter portion 102 and the small-diameter portion 103, the outer diameter of which gradually increases toward the top (i.e., from the small-diameter portion 103 to the large-diameter portion 102). The small-diameter portion 103 is formed so that, in a state where the piston 92 moves upward with respect to the electromagnet 91, it abuts against the through-holes 28 of the tubular wall 27 in the radial direction of the tubular wall 27, as shown on the right side of the center line C in Fig. 14 shown.

[0051] In each of the four through holes 28 of the tubular wall 27, a ball 105 is mounted, which is part of the connecting mechanism 7. The balls 105 can be mounted in the through holes 28 in a state in which the piston 92 moves upwards (ie, towards the robot arm 3), as shown on the right side of the center line C in Fig. 14. In addition, the balls 105 are shown in a state in which the piston 92 moves downward (ie, toward the tool attachment portion 6) with respect to the electromagnet 91, as shown on the left side of the center line C in Fig. 14, the balls 105 are pushed outward in the radial direction of the tubular wall 27 by the tapered surface 104 and the large-diameter portion 102. In a state where the piston 92 is at the lowest position, the balls 105 partially protrude from the tubular wall 27. At this time, the ball 105 is brought into contact with the tapered surface 29 formed on the opening portion of the through-hole 28 and held in the through-hole 28 in a state where it does not fall out of the through-hole 28. That is, the ball 105 is retractably held in the tubular wall 27. In other words, the through-hole 28 formed in the tubular wall 27 constitutes a ball holding portion that retractably holds the ball 105.

[0052] The one on the right side of Fig. The position of the piston 92 shown in Figure 14, ie the position of the piston 92 in which the small diameter portion 103 is located next to the through holes 28 and the balls 105 can be fully accommodated in the through holes 28, is hereinafter referred to as the "release position". The position shown on the left side of Fig. The position of the piston 92 shown in Fig. 14, ie the position of the piston 92 in which the balls 105 are pushed through the large diameter portion 102 and protrude from the tubular wall 27, is referred to as the “locking position”.

[0053] As in Fig. As shown in Fig. 13, in a state where the tool attachment portion 6 is attached to the main body portion 5, the through holes 28 and the balls 105 are located at the same position as the large-diameter hole 56 of the fourth frame member 47 in the vertical direction. Therefore, when the piston 92 moves to the locking position in this state, the ball 105 is inserted into the hole 56 of the fourth frame member 47, as shown on the left side of the center line C in Fig. Fig. 13. Since the balls 105 engage the engagement wall 55, the tool attachment portion 6 cannot be detached from the main body portion 5 in the locked state.

[0054] When the piston 92 moves from this state to the release position as shown in Fig. 15A, nothing pushes the balls 105 outward in the radial direction of the tube wall 27. That is, in this state, the pressure of the piston 92 on the balls 105 is terminated. In this state, if the main body section 5 is moved in a direction of separation from the tool attachment section 6, as shown in Fig. 15B, the balls 105 are pushed by the tilting surface 55b of the fourth frame member 47 and pressed into the tube wall 27. When the main body portion 5 is further separated from the tool attachment portion 6, the engagement state between the engagement wall 55 and the balls 105 is released, as shown in Fig. 15C, and the tool attachment portion 6 can be detached from the main body portion 5.

[0055] As in Fig. As shown in Fig. 16, an armature 106 having a cylindrical bottom shape is fixed to the axial center of the piston 92 in a state where it is located on the same axis as the piston 92. The armature 106 according to this embodiment includes an inner cylindrical portion 106a through which the locking pin 92a of the piston 92 extends, a disc-shaped attraction 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 attraction portion 106b. The armature 106 is shaped so that it can be accommodated inside the second frame member 10.

[0056] The permanent magnet 20 provided at the inner bottom portion of the second frame member 10 is arranged at a position facing the attracting portion 106b of the armature 106, as shown in Fig. 14. Therefore, the magnetic force of the permanent magnet 20 acts on the armature 106, which is mounted within the second frame element 10.

[0057] In a state where no magnetic force other than the magnetic force of the permanent magnet 20 acts on the armature 106 (a state where the electromagnet 91 of the solenoid 12 is not activated), as shown in Fig. As shown in Fig. 14, the armature 106 is attracted to the inner bottom surface 10a of the second frame member 10 by the magnetic force of the permanent magnet 20. When the armature 106 is attracted to the inner bottom surface 10a of the second frame member 10, the piston 92 moves downward (i.e., toward the tool mounting portion 6) and is held by the permanent magnet 20.

[0058] In the solenoid 12 according to this embodiment, the armature 106 is attracted to the inner bottom surface 10a of the second frame member 10 by the magnetic force of the permanent magnet 20, and the piston 92 is in the above-described locking position as shown on the left side of the center line C in Fig. 14. In this state, the permanent magnet 20 magnetically keeps the piston 92 moving, so that the balls 105 protrude from the tubular wall 27.

[0059] As in Fig. As shown in Figure 16, the electromagnet 91 includes a cylindrical field core 109 having an annular groove 108 for receiving a cylindrical electromagnetic coil 107, and the support plate 17 extending radially outward from the upper end of the field core 109. The annular groove 108 of the field core 109 opens toward the armature 106. A vertically extending shaft hole 110 is formed at the axial center of the field core 109. The locking pin 92a of the plunger 92 is inserted into the shaft hole 110 and supported by a bearing member 111 provided at the upper end portion of the shaft hole 110 so as to be movable in the vertical direction.

[0060] As in the Fig. 6 and Fig. 7, the support plate 17 is fixed by the first fastening bolts 16 (see Fig. 7) and the guide pin 19 (see Fig. 6) is fixed to the first frame member 9 in a state where it is sandwiched between the first frame member 9 and the fixing plate 18. The guide pin 19 is pressed into the pin hole 17a of the support plate 17 and fitted into the third through hole 15 of the first frame member 9. The first fixing bolts 16 are passed through 15 through holes 112 in the support plate 17 and engaged with the first screw holes 13 of the first frame member 9.

[0061] According to this embodiment, a small-diameter portion 109a, which is inserted into the outer cylindrical portion 106c of the armature 106, is formed on the outer peripheral portion at the lower end side of the field core 109. A gap is formed between the outer peripheral surface of the small-diameter portion 109a and the inner peripheral surface of the outer cylindrical portion 106c, through which the magnetic flux of the electromagnetic coil 107 can flow.

[0062] A circular hole 109b opening toward the bottom is formed in the inner peripheral portion at the lower end portion of the field core 109. The hole 109b is configured to accommodate the inner cylindrical portion 106a of the armature 106. The inner peripheral surface of the hole 109b and the outer peripheral surface of the inner cylindrical portion 106a of the armature 106 gradually slope inward toward the top in the radial direction. A gap is formed between the inner peripheral surface of the hole 109b and the outer peripheral surface of the inner cylindrical portion 106a, which can pass the magnetic flux of the electromagnetic coil 107.

[0063] When the electromagnetic coil 107 of the electromagnet 91 is activated and the electromagnet 91 is activated, the field core 109 and the armature 106 form a magnetic path, the magnetic flux flows to the field core 109 and the armature 106, as shown by an alternating long and two short dashed lines in Fig. 16, and a magnetic attraction force acts on the armature 106 in a direction in which the armature 106 is pulled up. The electromagnet 91 generates a magnetic attraction force, so that the armature 106, which is attracted to the third frame element 46 by the magnetic force of the permanent magnet 20, is pulled up against the magnetic attraction force of the permanent magnet 20. Thus, when the electromagnet 91 is activated, the armature 106 is attracted to the field core 109 by the magnetic force, and the field core 109 is closed by the armature 106, as shown on the right side of the center line C in Fig. 16. When the armature 106 is attracted to the field core 109 by the magnetic force, the piston 92 is in the release position, as shown on the right side of the center line C in Fig. 13 shown. Operation

[0064] In order to attach the tool 4 to the robot arm 3 using the robot tool changing device 1 configured in this way, first, as shown in Fig. 17A, the solenoid 12 of the main body section 5 is activated to move the piston 92 to the release position. Then, the robot arm 3 is actuated to move the main body section 5 near the tool attachment section 6, and the tubular wall 27 of the main body section 5 is inserted into the hole 54 of the tool attachment section 6, as shown in Fig. 17B. At this time, when the balls 105 protrude from the tubular wall 27, the balls 105 contact the convex curved surface 55a of the engaging wall 55 and are thereby pressed into the tubular wall 27.

[0065] Next, in a state where the tubular wall 27 is inserted into the hole 54 and the second frame member 10 rests on the fourth frame member 47, the supply to the solenoid 12 is interrupted. When the solenoid 12 loses the magnetic force, the armature 106 is attracted to the inner bottom surface 10a side of the second frame member 10 by the magnetic attraction force of the permanent magnet 20. As shown in Fig. As shown in Fig. 17C, the armature 106 is attracted to the second frame member 10 by the magnetic attraction force of the permanent magnet 20. As a result, the piston 92 moves to the other end side and is held by the permanent magnet 20.

[0066] At this moment, the columnar body 92b of the piston 92 moves downward in the tube wall 27, and the balls 105 are pushed by the columnar body 92b during the movement and protrude from the tube wall 27. The balls 105 are inserted into the large-diameter hole 56 of the fourth frame member 47. When the balls 105 are inserted into the large-diameter hole 56, the balls 105 engage the engagement wall 55, and the main body portion 5 cannot be separated upward from the tool attachment portion 6. Work with the tool 4 is performed in a locked state in which the main body portion 5 and the tool attachment portion 6 are joined together.

[0067] To release the tool 4 from the tool mounting section 6, the robot arm 3 is operated so that the tool mounting section 6 is placed on a support table (not shown), and the solenoid 12 is energized in this state. When the solenoid 12 is energized, the magnetic attraction force of the electromagnet 91 acts on the armature 106, and the armature 106 is attracted to the field core 109 against the magnetic attraction force of the permanent magnet 20. While the armature 106 is attracted to the field core 109, as shown in Fig. 15A, the columnar body 92b of the piston 92 moves upward in the tube wall 27, so that the balls 105 are placed in a movable state.

[0068] The robot arm 3 is then operated to move the main body portion 5 upward. As the main body portion 5 moves upward relative to the tool attachment portion 6, the balls 105 are pressed against the tilting surface 55b of the engagement wall 55 and pushed into the tubular wall 27, as shown in Fig. 15B, and the engagement state between the balls 105 and the engagement wall 55 is terminated. Therefore, when the main body portion 5 is moved upward in an ON state of the solenoid 12, as shown in Fig. 15C, the main body portion 5 is detached from the top of the tool attachment portion 6. Method for manually performing the separation

[0069] In the robot tool changing device 1 according to this embodiment, the operation of detaching the main body portion 5 from the tool mounting portion 6 can be performed manually without energizing the solenoid 12. To manually detach the main body portion 5 from the tool mounting portion 6, the stopper 100 is first released, as shown in Fig. 18, and the manual release lever 93 is pulled upwards with respect to the solenoid 12, as shown on the right side of the center line C in Fig. 19. When the lever 93 is operated in this way, the piston 92 moves upward together with the lever 93, the small-diameter portion 103 of the columnar body 92b is located in an area adjacent to the balls 105, and the balls 105 can move freely. When the main body portion 5 is moved upward in this state with respect to the tool attachment portion 6, as shown in Fig.15C, the main body portion 5 can be detached from the tool attachment portion 6.

[0070] Even in a state where the manual release lever 93 is operated to move the piston 92 so that the armature 106 comes into contact with the field core 109, the main body portion 5 can be attached to the tool attachment portion 6 without energizing the solenoid 12. That is, according to the robot tool changing device 1, it is possible to manually detach the main body portion 5 from the tool attachment portion 6 or manually attach the main body portion 5 to the tool attachment portion 6. Effects of the embodiment

[0071] The robot tool changing device 1 according to this embodiment employs a configuration in which a locked state of the main body portion 5 fixed to the tool mounting portion 6 is maintained by the magnetic attraction force of the permanent magnet 20. Therefore, compared to a case where a compression coil spring is used to maintain the locked state, the structure for maintaining the locked state can be kept small. Therefore, according to this embodiment, it is possible to provide a robot tool changing device with a smaller size.

[0072] The engagement wall 55 of the fourth frame member 47 according to this embodiment includes the tilting surface 55b that contacts the balls 105. The tilting surface 55b gradually inclines toward the radial center of the hole 54 of the fourth frame member 47 toward the opening edge of the hole 54. Since the balls 105 can be pushed by the tilting surface 55b and pushed into the tube wall 27 when the main body portion 5 is released from the tool attachment portion 6, no special operation is required to release the locking state.

[0073] The columnar body 92b (second portion) of the piston 92 according to this embodiment includes the large-diameter portion 102 connected to the locking pin 92a (first portion) of the piston 92, the small-diameter portion 103 having an outer diameter smaller than the outer diameter of the large-diameter portion 102, and the tapered surface 104 disposed between the large-diameter portion 102 and the small-diameter portion 103 and having an outer diameter gradually increasing from the small-diameter portion 103 to the large-diameter portion 102.When the piston 92 moves toward the tool mounting portion 6, the balls 105 held by the small-diameter portion 103 are pushed outward in the radial direction of the tubular wall 27 by the tapered surface 104 and the large-diameter portion 102, and the balls 105 partially protrude from the tubular wall 27. For this reason, no special operation needs to be performed to achieve the locking state.

[0074] The tubular wall 27 (housing) according to this embodiment includes a ball holding portion configured to retractably hold the balls 105. The ball holding portion includes the through-holes 28 extending between the inner peripheral surface 27a of the tubular wall 27, which faces the columnar body 92b of the piston 92, and the outer peripheral surface 27b of the tubular wall 27, which faces the fourth frame member 47. The through-hole 28 has a tapered surface 29 whose inner diameter gradually decreases toward the outer peripheral surface 27b of the tubular wall 27. The ball 105 is brought into contact with the tapered surface 29 and held in the through-hole 28 without falling out of the through-hole 28. Thus, the ball holding portion can retractably hold the balls 105.

[0075] The electromagnet 91 is cylindrical in shape in this embodiment. The piston 92 includes the armature 106, which lies on the same axis as the electromagnet 91. The permanent magnet 20 is arranged at a position facing the armature 106. Since the direction in which the armature 106 can move and the direction in which the armature 106 is attracted by the magnetic attraction force of the permanent magnet 20 are parallel, the piston 92 can be reliably held in the locking position by efficiently utilizing the magnetic attraction force of the permanent magnet 20.

[0076] The electromagnet 91 according to this embodiment includes the cylindrical electromagnetic coil 107 and the cylindrical field core 109 with the annular groove 108 configured to be open toward the armature 106 and accommodate the electromagnetic coil 107. The armature 106 and the field core 109 form a magnetic path. When the electromagnetic coil 107 of the electromagnet 91 is energized and the electromagnet 91 is activated, a magnetic flux flows to the field core 109 and the armature 106, and a magnetic attraction force to the electromagnet 91 acts on the armature 106. When the armature 106 is attracted to the field core 109 by the magnetic force, the piston 92 can be moved to the release position.

[0077] The first portion of the piston 92 according to this embodiment includes the locking pin 92a extending through the axial center of the cylindrical electromagnet 91. The main body portion 5 further includes the manual release lever 93, which is connected to the distal end portion of the locking pin 92a and configured to move the locking pin 92a toward the robot arm 3. By operating the manual release lever 93, it is therefore possible to switch between the locked state and the released state without supplying power to the solenoid 12.

[0078] The connecting portion between the lever 93 and the locking pin 92a includes the through-hole 98 formed in the lever 93 and the bolt 99 (coupling member) connected to the distal end portion of the locking pin 92a inserted into the through-hole 98. According to this embodiment, the stepped portion 98a projecting radially inward is formed in the through-hole 98, but the stepped portion 98a is not essential. It is only required that the through-hole 98 has a larger inner diameter than the outer diameter of the locking pin 92a, and that the bolt 99 has a head portion 99a with a larger outer diameter than the inner diameter of the through-hole 98.With this structure, for manually detaching the main body portion 5 from the tool attachment portion 6, when the lever 93 is pulled upward, the lever 93 can abut against the head portion 99a of the bolt 99, and the locking pin 92a can be pulled upward integrally with the lever 93. On the other hand, when detaching the main body portion 5 from the tool attachment portion 6 by activating the solenoid 12, the movement of the locking pin 92a by the magnetic force of the electromagnet 91 is never obstructed by the lever 93.

[0079] The robot tool changing device 1 according to the above-described embodiment employs a configuration in which the air passage forming members 22 and 23 are provided in the main body portion 5, the air passage forming members 42 and 43 are provided in the tool mounting portion 6, and an air-driven tool can be used as the tool 4. However, when an electric tool is used as the tool 4, the air passage forming members 22, 23, 42, and 43 need not be provided. In this case, the structure can be simplified because no air ducts are required in the robot tool changing device 1 or on the robot side. Inclusion by reference

[0080] This application claims foreign priority to Japanese Patent Application No. JP2023-198267, filed on November 22, 2023, which is incorporated by reference in its entirety. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] JP 2023-198267

[0080]

Claims

[1] Robot tool changing device with a main body portion attached to a robot arm; and a tool attachment portion having a mounting seat to which a tool for the robot arm is attached and which is detachably attached to the main body portion, where the main body section includes: a solenoid containing an electromagnet and a piston configured to move toward the robot arm by a magnetic force of the electromagnet, the piston including a first portion on a side of the robot arm and a second portion on a side of the tool mounting portion; a housing configured to receive the second portion of the piston; a ball retractably held by the housing, the ball being configured such that when the piston moves toward the tool attachment portion, the ball is pushed by the piston and protrudes from the housing, and the pushing by the piston is terminated when the piston moves toward the robot arm; and a permanent magnet configured to move the piston toward the tool mounting portion and to hold the piston when the electromagnet is not activated, the tool mounting section includes: a frame member having a hole formed therein for receiving the housing, and the frame member having an engagement wall provided on a wall surface of the hole and configured to engage with the ball protruding from the housing and prevent the housing from coming off the hole. [2] Robot tool changing device according to claim 1, wherein the engagement wall has a tilting surface that contacts the ball, and the tilting surface gradually inclines toward a radial center of the hole toward an opening edge of the hole. [3] A robot tool changing device according to claim 1 or 2, wherein the second portion of the piston comprises: a large diameter section connected to the first section; a small diameter section whose outer diameter is smaller than the outer diameter of the large diameter section; and a tapered surface disposed between the large diameter portion and the small diameter portion and having an outer diameter that gradually increases from the small diameter portion to the large diameter portion. [4] Robot tool changing device according to claim 1 or 2, wherein the housing has a ball retaining portion configured to retractably retain the ball, the ball holding portion has a through hole extending between an inner peripheral surface of the housing opposite the second portion of the piston and an outer peripheral surface of the housing opposite the frame member, and the through hole has a tapered surface with an inner diameter that gradually decreases towards the outer peripheral surface. [5] Robot tool changing device according to claim 1, wherein the electromagnet is cylindrical in shape, the piston further comprises an armature arranged on the same axis as the electromagnet, and the permanent magnet is arranged in a position facing the armature. [6] Robot tool changing device according to claim 5, wherein the electromagnet includes: a cylindrical electromagnetic coil; and a cylindrical field core having an annular groove configured to be open toward the armature and to receive the electromagnetic coil, and the armature and the field core form a magnetic path. [7] The robot tool changing device of claim 6, wherein the armature is configured to close the field core. [8] Robot tool changing device according to claim 1, wherein the electromagnet is brought into a cylindrical shape, the first portion of the piston has a locking pin extending through an axis center of the electromagnet, and the main body portion further comprises a manual release lever connected to a distal end portion of the locking pin and configured to move the locking pin toward the robot arm. [9] Robot tool changing device according to claim 8, wherein a connecting section between the lever and the locking pin comprises a through hole formed in the lever and having an inner diameter larger than an outer diameter of the locking pin; and a coupling element connected to the distal end portion of the locking pin inserted into the through-hole and having a head portion with a larger outer diameter than the inner diameter of the through-hole.

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