Tool replacing mechanism

Abstract

To provide a tool replacing mechanism which can reduce manufacturing cost and support a large load with a simple configuration.SOLUTION: In a tool replacing mechanism 10, an insertion section 86 of a tool connection section 85 is inserted into a clamp section 50 with the clamp section 50 in a disengaged state by the operation of a robot R with a tool unit 80 being held by a positioning plate 105. The clamp section 50 is brought into an engaged state and a coupled state is created by regulating the rotation of a housing 60. The clamp section 50 is brought into a disengaged state from the engaged state by moving the tool unit 80 to a storage recess section 101 by the operation of the robot R from the coupled state and a separated state is created since the regulation of the rotation of the housing 60 is released.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a tool changing mechanism for exchanging various tools by the operation of a robot arm.

Background Art

[0002] As a conventional tool changer (tool changing mechanism), there is one described in Patent Document 1. According to this, it includes a tool plate having an insertion recess on the upper surface, and a master plate having a surface that contacts the upper surface in a connected state and a cylindrical portion that can be inserted into the insertion recess, and the tool plate is detachably connected.

[0003] The master plate has a cylindrical portion, and a plate body in which a cylinder chamber and a flow path for supplying fluid to the cylinder chamber are formed inside, at least one locking portion held by the cylindrical portion and provided so as to be able to protrude and retract from the side surface of the cylindrical portion, and a piston member that is attached to the plate body so as to be reciprocable in the cylindrical portion in a direction substantially perpendicular to the one surface by the pressure in the cylinder chamber and that causes the locking portion to protrude and retract by the reciprocating motion.

[0004] The tool plate has a locked portion that is engaged and disengaged with the locking portion by the locking portion protruding and retracting in a state where the cylindrical portion is inserted into the insertion recess.

[0005] In addition, as those related to Patent Document 1, there are those described in Patent Documents 2 to 4.

[0006] Although those described in Patent Documents 1 to 4 do not affect the patentability of the present invention, a configuration such as a piston member inside and an electrode outside is required, and an electric motor and an air motor need to be provided on the tool unit side, so there is a problem that the device becomes large-sized.

[0007] In response to the above problems, as an alternative to providing a mechanism for separating and coupling the tool unit inside, there is a tool changer described in Patent Document 5 previously filed by the applicant. According to this, it includes a rotational drive unit that rotationally drives a spindle shaft, a spindle body that is connected to the rotational drive unit and rotatably holds the spindle shaft inside, a clamp unit provided at the tip of the spindle shaft, a tool collet that is clamped by the clamp unit and has a tool attached thereto, and a tool magazine that holds a plurality of tool collets. A gear portion is provided on the outer peripheral portion of the tool collet, and the tool magazine is provided with a storage recess for storing the tool collet, and a rack portion engageable with the gear portion of the tool collet is provided on one wall portion of the storage recess.

Prior Art Documents

Patent Documents

[0008]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Summary of the Invention

Problems to be Solved by the Invention

[0009] However, in the above tool changer, a gear portion is provided on the outer peripheral portion of the tool collet, and the tool magazine is provided with a rack portion engageable with the gear portion of the tool collet and an inclined surface for sliding the clamp sleeve. Therefore, the configuration becomes complicated and the manufacturing cost may increase. Thus, it has been desired to simplify the configuration and reduce the manufacturing cost.

[0010] In addition, since power transmission is achieved using small clamp balls and dimples on the spindle side, it is difficult to transmit large torques, and only small tools and brushes could be attached to the tool collet. Furthermore, since this part also doubled as a mechanism for separating and coupling the tool collet, it was also difficult to support large loads, and improvement was demanded.

[0011] In view of the above circumstances, the present invention provides a tool changing mechanism that has a simple configuration, can reduce manufacturing costs, and can support large loads.

Means for Solving the Problems

[0012] The invention according to claim 1 comprises a master unit attached to a robot, a tool unit to which a tool is attached, and a tool magazine that holds the tool unit, and the tool unit can be in a separated state held in the tool magazine and a coupled state in which it is coupled to the master unit and can perform work, and is a tool changing mechanism, The master unit includes a rotation drive unit that rotationally drives a spindle shaft, and a clamp unit provided on the spindle shaft side, The clamp unit includes clamp balls, a cylindrical ball case having a ball holding hole that allows the tool connecting part described later to enter and enables the spindle shaft to rotate inside, and that enables the clamp balls to move in a direction orthogonal to the axial direction of the spindle shaft, a cylindrical housing that has a receiving recess for receiving the clamp balls, is fitted outside the ball case, and is rotatable with respect to the ball case by the operation of the robot, and is provided with The ball case is provided with a locking portion formed in a concave or convex shape that restricts the rotation of the ball case, The housing has A lock member that enables entry into and out of the housing and holds and releases the coupled state, and a biasing member that biases the lock member toward the tool unit along the axial direction of the spindle shaft are provided. The receiving recess is formed as a recess extending from the inner peripheral surface to the outer peripheral surface of the housing. The tool unit is provided with a tool connection portion that can be connected to the clamp portion. The tool connection portion includes an insertion portion that is inserted into the clamp portion and a flange portion that extends outward on the proximal end side of the insertion portion. An annular clamp groove that can engage with the clamp ball is provided in the insertion portion. The flange portion is formed in a concave or convex shape corresponding to the locking portion, and has a locked portion that locks with the locking portion to restrict rotation of the ball case, a lock release pin described later, and a lock hole into which the lock member can enter. are provided. The tool magazine is provided with a storage recess for storing the tool unit. A positioning plate is disposed on the outer peripheral edge of the storage recess. The positioning plate is provided with a lock release pin that can enter the lock hole and releases the coupled state. The clamp portion is in a disengagement state in which the clamp ball is received in the receiving recess and the tool connection portion can be inserted into the clamp portion, and can take an engaged state in which the clamp ball abuts against the inner peripheral surface of the housing and engages with the clamp groove. In the separated state, the tool unit is placed and held on the positioning plate with the lock release pin inserted into the lock hole of the flange portion of the tool unit. With the tool unit held by the positioning plate, by the operation of the robot, in the disengaged state, the insertion portion of the tool connection portion is inserted into the clamp portion, the locking portion and the locked portion are locked, and the housing is disposed at a position where the locking member is rotated by a predetermined angle from the locking hole. By rotating the locking member to the position of the locking hole and moving it upward, the locking member enters the locking hole, and the unlocking pin exits from the locking hole, so that the clamp portion is in the engaged state, and the rotation of the housing is restricted to enter the coupled state. From the coupled state, by the operation of the robot, the tool unit is moved to the storage recess and further downward, and the unlocking pin is inserted into the locking hole, so that the locking member exits from the locking hole, the locking member is rotated by a predetermined angle from the locking hole, and moved upward, so that the clamp portion changes from the engaged state to the disengaged state, and the restriction on the rotation of the housing is released to enter the separated state.

[0013] According to this, with the configuration of the locking portion, the locked portion, the locking hole and the unlocking pin, the locking member, and the biasing member having an uneven shape, it is possible to change the clamp portion between the engaged state and the disengaged state, and with a simple configuration, the manufacturing cost can be reduced.

[0014] In addition, in the present invention, since the mechanism for transmitting the power of the rotational drive unit and the mechanism for setting the tool unit in the separated state and the coupled state can be configured separately, a large load can be supported.

[0015] Furthermore, it should be noted that even with such a configuration, there is no need for an external configuration such as an electrode, and there is no need to provide a mechanism for setting the tool unit in the separated state and the coupled state inside the ball case. Since it is possible to provide a mechanism for transmitting the driving force of the spindle shaft inside the ball case, there is no need to provide an electric motor or an air motor on the tool unit side, which leads to a reduction in the weight of the tool unit.

[0016] Further, the locking portion is a rotation prevention pin protruding from the ball case, and the locked portion is the rotation prevention hole into which the rotation prevention pin can be inserted.

[0017] According to this, with a simple configuration of a rotation prevention hole and a rotation prevention pin, the housing is prevented from rotating with respect to the ball case, so that with a simple configuration, it leads to a reduction in manufacturing cost.

[0018] Also, the length of the lock hole in the thickness direction and the length of the lock release pin in the longitudinal direction are substantially the same.

[0019] According to this, by inserting and removing the lock member into and out of the lock hole with the lock release pin, the clamp portion can be changed between an engaged state and a disengaged state, so that a simple configuration is achieved and it leads to a reduction in manufacturing cost.

Brief Description of the Drawings

[0020]

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

Embodiments for Carrying Out the Invention

[0021] Next, embodiments of the tool changing mechanism of the present invention will be described with reference to the drawings. In the following description, in FIGS. 7 to 9, the power transmission mechanisms such as the hexagonal boss 43, the receiving member 45, and the connecting member 82 are omitted.

[0022] The tool changing mechanism 10 generally includes, as shown in FIG. 1, a master unit 30 attached to the robot arm RA of the robot R, a tool unit 80 to which a tool is attached, and a tool magazine 100 that holds the tool unit 80. The tool unit 80 can take a separated state held by the tool magazine 100 and a combined state in which it can work in combination with the master unit 30.

[0023] As shown in FIGS. 2 to 8, 13, 14, etc., the master unit 30 includes a rotation drive unit 40 that rotationally drives a spindle shaft 41, and a clamp unit 50 provided on the spindle shaft 41 side.

[0024] The rotation drive unit 40 is composed of an existing electric motor. The rotation shaft of the rotation drive unit 40 is the spindle shaft 41, and the spindle shaft 41 is rotationally driven at high speed by the rotation drive unit 40.

[0025] The spindle shaft 41 has a hexagonal boss 43 attached to the tip side via a joint 42. The driving force is transmitted by connecting the hexagonal boss 43 and a connecting member 82 with a hexagonal hole, which will be described later, of the tool unit 80.

[0026] The spindle shaft 41 and the joint 42 are prevented from rotating relative to each other by using a key member 44.

[0027] Also, around the spindle shaft 41, a receiving member 45 for receiving an insertion portion 86, which will be described later, is disposed.

[0028] The clamp unit 50 includes a clamp ball 51, a ball case 53, and a housing 60.

[0029] The clamp balls 51 are existing clamp balls, and six of them are disposed in this embodiment.

[0030] The ball case 53 is formed in a cylindrical shape, and a tool connection portion 85, which will be described later, can enter. The ball case 53 has ball holding holes 54 that allow the clamp balls 51 to move in a direction perpendicular to the axial direction of the spindle shaft 41.

[0031] The ball holding holes 54 are through holes that penetrate from the inner peripheral surface 53a to the outer peripheral surface 53b of the ball case 53. Six of them are formed at equal intervals when viewed from the axial direction of the ball case 53. The width of the inner peripheral surface 53a side is formed to be narrow so that the clamp balls 51 do not escape.

[0032] The ball case 53 is provided with a locking portion that restricts the rotation of the ball case 53.

[0033] In the present embodiment, the locking portion is composed of two anti-rotation pins 55 that protrude downward from the ball case 53. The anti-rotation pins 55 are formed so as to be insertable into the anti-rotation holes 91 of the tool connection portion 85, which will be described later, and the ball case 53 can be restricted from rotating with respect to the tool unit 80.

[0034] On the outer peripheral surface 53b of the ball case 53, three ball grooves 56 are provided at equal intervals as bottomed grooves having a semi-circular cross-section that extend from the outer peripheral surface 53b toward the inner peripheral surface 53a, as viewed in the axial direction of the ball case 53.

[0035] In the present embodiment, the ball grooves 56 are formed in an arc shape of 30 degrees as viewed in the axial direction of the ball case 53. In other words, the ball grooves 56 are formed so as to allow a 30-degree rotation of the housing 60.

[0036] Holding balls 63, which will be described later, are rotatably disposed in the ball grooves 56.

[0037] Inside the ball case 53, the spindle shaft 41 and the hexagonal boss 43 are rotatable.

[0038] The housing 60 is formed in a cylindrical shape, fitted outside the ball case 53, and is rotatable with respect to the ball case 53 by the operation of the robot R, and has a receiving recess 61 that can receive the clamp ball 51.

[0039] The receiving recess 61 is formed as a substantially hemispherical bottomed hole that extends from the inner peripheral surface 60a to the outer peripheral surface 60b of the housing 60.

[0040] When the clamping ball 51 is received in the receiving recess 61, the clamping ball 51 does not protrude from the inner peripheral surface 53a of the ball case 53. When the clamping ball 51 abuts against the inner peripheral surface 60a of the housing 60 other than the receiving recess 61, the clamping ball 51 protrudes from the inner peripheral surface 53a of the ball case 53.

[0041] In the housing 60, three ball arrangement holes 62 formed as stepped through-holes extending from the outer peripheral surface 60b toward the inner peripheral surface 60a are provided at equal intervals as viewed in the axial direction.

[0042] Retention balls 63 are arranged on the inner peripheral surface 60a side of the housing 60 of the ball arrangement holes 62, and set screws 64 are arranged on the outer peripheral surface 60b side.

[0043] In the housing 60, three locking pin receiving portions 65 formed as stepped holes penetrating from the upper surface to the lower surface are provided at equal intervals in a triangular shape as viewed in the axial direction of the housing 60.

[0044] Bolts 66 are arranged on the upper surface side of the locking pin receiving portion 65, locking pins 67 as locking members are arranged on the lower surface side, and coil springs 68 as biasing members are arranged between the bolts 66 and the locking pins 67.

[0045] The coil spring 68 biases the locking pin 67 toward the tool unit 80 along the axial direction of the spindle shaft 41.

[0046] The locking pin 67 can enter and exit the inside and outside of the housing 60, and holds and releases the coupled state of the tool unit 80.

[0047] A bracket 70 is attached to the upper surface side of the housing 60. In the bracket 70, bolt holes 71 penetrating from the upper surface to the lower surface are formed at positions corresponding to the locking pin receiving portions 65.

[0048] The bracket 70 is formed with stepped through holes corresponding to the ball placement holes 62, and three ball placement holes 72 are provided where the holding balls 63 and the set screws 64 can be placed.

[0049] The bolt hole 71 and the lock pin housing portion 65 are communicated, the bolt 66 is screwed in and enters the lock pin housing portion 65, and a coil spring 68 is arranged between the bolt 66 and the lock pin 67, and the housing 60 and the bracket 70 are connected.

[0050] The housing 60 is connected to a connection unit 75 that is rotatably attached to the robot arm RA at the tip of the robot R via the bracket 70.

[0051] From the above, the clamp portion 50 can take an engagement release state in which the clamp ball 51 is received in the receiving recess 61 and the tool connection portion 85 can be inserted into the clamp portion 50, and an engagement state in which the clamp ball 51 abuts against the inner peripheral surface 60a of the housing 60 and engages with the clamp groove 87.

[0052] As shown in FIGS. 2 to 4, 7, 9, 12 to 14, etc., the tool unit 80 includes a main body portion 81 and a tool connection portion 85 that can be connected to the clamp portion 50.

[0053] The main body portion 81 is connected to the hexagonal boss 43 and includes a connecting member 82 with a hexagonal hole (see FIG. 9A) that can transmit the driving force of the spindle shaft 41 of the rotational drive unit 40, and an existing belt sander unit as a tool that eliminates the electric motor and includes a transmission mechanism such as a rotating shaft, a driven gear, and a pulley (not shown) that transmits the driving force received by the connecting member 82.

[0054] The tool connection portion 85 includes an insertion portion 86 that is inserted into the clamp portion 50 and a flange portion 90 that extends outward on the proximal end side of the insertion portion 86.

[0055] An annular clamp groove 87 that can engage with the clamp ball 51 is provided in the insertion portion 86.

[0056] The flange portion 90 is formed in a concave shape corresponding to the locking portion, and a locked portion is provided which locks with the locking portion to restrict the rotation of the ball case 53.

[0057] In the present embodiment, the locked portion is formed as a through hole penetrating from the upper surface to the lower surface of the flange portion 90, and is formed as a detent hole 91 into which the detent pin 55 can be inserted. The detent holes 91 are provided at two positions corresponding to the detent pins 55.

[0058] The flange portion 90 is provided with locking holes 92 into which a lock release pin 106 and a lock pin 67, which will be described later, can enter. The locking holes 92 are provided at three positions at equal intervals when viewed in the axial direction of the tool connection portion 85.

[0059] The length of the locking hole 92 in the thickness direction of the flange portion 90 is made substantially the same as the length in the longitudinal direction of the lock release pin 106, which will be described later.

[0060] The cylindrical portion below the flange portion 90 is inserted into the main body portion 81, and the main body portion 81 and the tool connection portion 85 are connected.

[0061] As shown in FIGS. 10 to 14 and the like, the tool magazine 100 is formed in a box shape with an open front side, and a storage recess 101 for storing the tool unit 80 is provided.

[0062] The storage recess 101 is formed by notching the ceiling wall 100a of the tool magazine 100 in a semi-elliptical shape from the front side to the rear side. A positioning plate 105 is disposed on the outer peripheral edge of the storage recess 101.

[0063] The positioning plate 105 is formed in a substantially U-shaped shape corresponding to the outer peripheral edge of the storage recess 101, and a lock release pin 106 that can enter the locking hole 92 and releases the coupled state is disposed.

[0064] The unlocking pins 106 are arranged at three positions concentrically and equidistantly in the vertical direction at positions corresponding to the lock holes 92 of the flange portion 90.

[0065] The usage mode of the tool changing mechanism 10 will be described. As shown in FIGS. 1 and 12, in the separated state, the tool unit 80 is placed and held on the positioning plate 105 with the unlocking pins 106 inserted into the lock holes 92 of the tool connection portion 85 of the tool unit 80.

[0066] With the tool unit 80 held by the positioning plate 105, the insertion portion 86 of the tool connection portion 85 is inserted into the clamp portion 50 of the master unit 30 shown in FIGS. 4 and 8 in the disengaged state by the operation of the robot R.

[0067] Then, the anti-rotation pin 55 and the anti-rotation hole 91 are locked so that the ball case 53 and the tool connection portion 85 do not rotate relative to each other (see FIGS. 3 and 14).

[0068] Furthermore, as shown in FIGS. 13 and 14, the housing 60 is arranged at a position where the lock pin 67 is rotated by a predetermined angle (30 degrees) from the lock hole 92. While sliding the lock pin 67 on the upper surface of the flange portion 90, the lock pin 67 is rotated to the position of the lock hole 92 and moved upward, so that the lock pin 67 enters the lock hole 92 and the unlocking pin 106 exits from the lock hole 92. Then, the clamp portion 50 enters the engaged state where the clamp ball 51 and the clamp groove 87 shown in FIGS. 5 and 7 are engaged, the rotation of the housing 60 is restricted, and the tool unit 80 is in the coupled state with the master unit 30 shown in FIG. 3.

[0069] It should be noted that in the tool changing mechanism 10 of the present embodiment, it has been confirmed by the measurement of the applicant that the tool unit 80 and the master unit 30 can support a load of 2 tons in the coupled state.

[0070] The tool unit 80 can perform deburring work while being coupled to the master unit 30.

[0071] From the coupled state, by the operation of the robot R, the tool unit 80 is moved to the storage recess 101 and further moved downward. As shown in FIGS. 13 and 14, the unlocking pin 106 is inserted into the locking hole 92 to cause the locking pin 67 to withdraw from the locking hole 92.

[0072] Then, while sliding the locking pin 67 on the upper surface of the flange portion 90, the locking pin 67 is rotated by a predetermined angle (30 degrees) from the locking hole 92 and moved upward. As a result, the clamp portion 50 changes from the engaged state shown in FIGS. 5 and 7 to the disengaged state in which the clamp ball 51 is received in the receiving recess 61 shown in FIGS. 6 and 8 in this order. The restriction on the rotation of the housing 60 is released, and the tool unit 80 is separated from the master unit 30 and the ball case 53 as shown in FIG. 12.

[0073] The tool changing mechanism 10 having the above configuration includes a master unit 30 attached to the robot R, a tool unit 80 to which a tool is attached, and a tool magazine 100 that holds the tool unit 80. The tool unit 80 can be in a separated state held by the tool magazine 100 and a coupled state in which it can work in combination with the master unit 30. The master unit 30 includes a rotation drive unit 40 that rotationally drives the spindle shaft 41 and a clamp portion 50 provided on the spindle shaft 41 side. The clamp portion 50 includes a clamp ball 51 a cylindrical ball case 53 having a ball holding hole 54 that allows the tool connecting portion 85 to enter and enables the spindle shaft 41 to rotate inside, and allows the clamp ball 51 to move in a direction orthogonal to the axial direction of the spindle shaft 41, a cylindrical housing 60 that has a receiving recess 61 capable of receiving the clamp ball 51, is fitted outside the ball case 53, and is rotatable with respect to the ball case 53 by the operation of the robot R. comprises The ball case 53 is provided with a rotation prevention pin 55 formed in a convex shape that restricts the rotation of the ball case 53. The housing 60 is provided with a lock pin 67 as a lock member that can enter and exit the inside and outside of the housing 60 and holds and releases the coupled state, and a coil spring 68 as a biasing member that biases the lock pin 67 toward the tool unit 80 along the axial direction of the spindle shaft 41. The receiving recess 61 is formed as a recess extending from the inner peripheral surface 60a to the outer peripheral surface 60b of the housing 60. The tool unit 80 is provided with a tool connection portion 85 that can be connected to the clamp portion 50. The tool connection portion 85 includes an insertion portion 86 that is inserted into the clamp portion 50 and a flange portion 90 that extends outward on the proximal end side of the insertion portion 86. The insertion portion 86 is provided with an annular clamp groove 87 that can engage with the clamp ball 51. The flange portion 90 is formed in a concave shape corresponding to the rotation prevention pin 55, and has a rotation prevention hole 91 as a locked portion that engages with the rotation prevention pin 55 to restrict the rotation of the ball case 53, and a lock hole 92 into which the lock release pin 106 and the lock pin 67 can enter. are provided. The tool magazine 100 is provided with a storage recess 101 for storing the tool unit 80. A positioning plate 105 is arranged on the outer peripheral edge of the storage recess 101. The positioning plate 105 is provided with a lock release pin 106 that can enter the lock hole 92 and releases the coupled state. The clamp portion 50 is in a disengaged state where the clamp ball 51 is received in the receiving recess 61 and the tool connection portion 85 can be inserted into the clamp portion 50, and can be in an engaged state where the clamp ball 51 abuts against the inner peripheral surface 60a of the housing 60 and engages with the clamp groove 87. In the separated state, with the unlocking pin 106 inserted into the locking hole 92 of the flange portion 90 of the tool unit 80, the tool unit 80 is placed and held on the positioning plate 105. With the tool unit 80 held by the positioning plate 105, by the operation of the robot R, in the disengaged state, the insertion portion 86 of the tool connecting portion 85 is inserted into the clamp portion 50, the anti-rotation pin 55 and the anti-rotation hole 91 are locked, the housing 60 is arranged at a position where the locking pin 67 is rotated by a predetermined angle from the locking hole 92, the locking pin 67 is rotated to the position of the locking hole 92 and moved upward, so that the locking pin 67 enters the locking hole 92, and the unlocking pin 106 is withdrawn from the locking hole 92, the clamp portion 50 becomes the engaged state, and the rotation of the housing 60 is restricted to become the coupled state. From the coupled state, by the operation of the robot R, the tool unit 80 is moved to the storage recess 101 and further moved downward, and the unlocking pin 106 is inserted into the locking hole 92, so that the locking pin 67 is withdrawn from the locking hole 92, the locking pin 67 is rotated by a predetermined angle from the locking hole 92 and moved upward, so that the clamp portion 50 changes from the engaged state to the disengaged state, and the restriction on the rotation of the housing 60 is released to become the separated state.

[0074] According to this, with the configuration of the anti-rotation pin 55 having an uneven shape, the anti-rotation hole 91, the locking hole 92, the unlocking pin 106, and the coil spring 68, it is possible to change the clamp portion 50 between the engaged state and the disengaged state, and with a simple configuration, the manufacturing cost can be reduced.

[0075] Also, in the present invention, since it is possible to make the mechanism for transmitting the power of the rotary drive unit 40 and the mechanism for making the tool unit 80 in the separated state and the coupled state have different configurations, a large load can be supported.

[0076] Furthermore, even with such a configuration, the need for external components such as electrodes is eliminated, and there is no need to provide a mechanism for separating and coupling the tool unit 80 inside the ball case 53. Instead, a mechanism for transmitting the driving force of the spindle shaft 41 can be provided inside the ball case 53. This eliminates the need to install an electric motor or an air motor on the tool unit 80 side, leading to a reduction in the weight of the tool unit 80.

[0077] Also, the locking portion is the anti-rotation pin 55 that protrudes from the ball case 53. The portion to be locked is the anti-rotation hole 91 into which the anti-rotation pin 55 can be inserted.

[0078] According to this, with the simple configuration of the anti-rotation hole 91 and the anti-rotation pin 55, the housing 60 is prevented from rotating relative to the ball case 53. This leads to a reduction in manufacturing costs with a simple configuration.

[0079] Also, the length of the lock hole 92 in the thickness direction is substantially the same as the length of the lock release pin 106 in the longitudinal direction.

[0080] According to this, by inserting and removing the lock pin 67 into and out of the lock hole 92 with the lock release pin 106, the clamp portion 50 can be changed between the engaged state and the disengaged state. This results in a simple configuration and a reduction in manufacturing costs.

[0081] A modification of the present invention will be described with reference to the drawings. For the configurations corresponding to the above-described embodiments, the same reference numerals are added, and the description of all or part thereof is omitted. In FIGS. 5 and 6, although there are parts different from this modification, for the purpose of explaining the functions, the reference numeral of the lock ball 67-1 is shown in parentheses.

[0082] In this modified example, as shown in FIGS. 15 to 17, a bolt 66 is arranged on the upper surface side of a lock pin housing portion 65 (which should be called a lock ball housing portion, but is denoted as it is), and on the lower surface side, from below, a lock ball 67-1 as a locking member and a ball receiver 67-2 for receiving the lock ball 67-1 are arranged, and a coil spring 68 as a biasing member is arranged between the bolt 66 and the ball receiver 67-2. Note that the lower end portion of the lock pin housing portion 65 has a reduced diameter so that the lock ball 67-1 can enter and exit and cannot completely pop out.

[0083] The coil spring 68 biases the lock ball 67-1 along the axial direction of the spindle shaft 41 toward the tool unit 80 side.

[0084] The lock ball 67-1 can enter and exit inside and outside the housing 60, and holds and releases the coupled state of the tool unit 80.

[0085] The usage mode of the tool changing mechanism 10 of this modified example is the same as that of the above-described embodiment. Therefore, the detailed description of the same parts is omitted in whole or in part, and only the different parts will be described in detail.

[0086] With the tool unit 80 held by the positioning plate 105, by the operation of the robot R, when the clamp portion 50 of the master unit 30 is in the disengaged state, the insertion portion 86 of the tool connection portion 85 is inserted into the clamp portion 50 (see FIGS. 15 and 16).

[0087] Then, the anti-rotation pin 55 and the anti-rotation hole 91 are locked so that the ball case 53 and the tool connection portion 85 do not rotate relative to each other (see FIG. 16).

[0088] Furthermore, the housing 60 is disposed at a position where the lock ball 67-1 is rotated from the lock hole 92 by a predetermined angle (30 degrees). While rolling the lock ball 67-1 on the upper surface of the flange portion 90, the lock ball 67-1 is rotated to the position of the lock hole 92 and moved upward, so that the lock ball 67-1 enters the lock hole 92 and the unlocking pin 106 exits from the lock hole 92. Then, the clamp portion 50 is in an engaged state where the clamp ball 51 and the clamp groove 87 are engaged as shown in FIG. 5, the rotation of the housing 60 is restricted, and the tool unit 80 is in a coupled state with the master unit 30 as shown in FIG. 17.

[0089] From the coupled state, by the operation of the robot R, the tool unit 80 is moved to the storage recess 101 and further moved downward. As shown in FIG. 16, the unlocking pin 106 is inserted into the lock hole 92, so that the lock ball 67-1 exits from the lock hole 92.

[0090] Then, while rolling the lock ball 67-1 on the upper surface of the flange portion 90, the lock ball 67-1 is rotated from the lock hole 92 by a predetermined angle (30 degrees) and moved upward. Thus, the clamp portion 50 changes from the engaged state shown in FIG. 5 to the disengaged state where the clamp ball 51 is received in the receiving recess 61 as shown in FIG. 6 in order. The restriction on the rotation of the housing 60 is released, and the tool unit 80 is separated from the master unit 30 and the ball case 53.

[0091] Even with such a configuration, it has a simple structure, can reduce the manufacturing cost, and can support a large load. Furthermore, by rolling the lock ball 67-1 on the upper surface of the flange portion 90, the durability of the lock member can be improved.

[0092] The tool changing mechanism 10 of the present invention is not limited to the above configuration. That is, various design changes and the like are possible without departing from the gist of the present invention.

[0093] For example, the concave-convex shapes of the locking portion and the locked portion can be reversed, and the number can also be appropriately changed according to the usage mode.

[0094] Also, the number, shape, etc. of the clamp ball 51, ball holding hole 54, holding ball 63, ball holding hole 54, lock hole 92, lock release pin 106, lock pin 67, lock ball 67-1, etc. can be appropriately changed according to the usage mode.

[0095] In addition, the tool unit 80 can apply a tool unit of a rotational drive system such as a rigid unit other than the belt sander unit.

Explanation of Reference Numerals

[0096] 10 Tool changer 30 Master unit 40 Rotational drive unit 41 Spindle shaft 50 Clamp section 51 Clamp ball 53 Ball case 54 Ball holding hole 55 Anti-rotation pin 60 Housing 60a Inner peripheral surface 60b Outer peripheral surface 61 Receiving recess 67 Lock pin 67-1 Lock ball 68 Coil spring 80 Tool unit 85 Tool connection part 86 Insertion part 87 Clamp groove 90 Flange part 91 Anti-rotation hole 92 Lock hole 100 Tool magazine 101 Storage recess 105 Positioning plate 106 Lock release pin R Robot

Claims

1. A tool changer comprising a master unit attached to a robot, a tool unit to which a tool is attached, and a tool magazine for holding the tool unit, wherein the tool unit can be in a separated state held in the tool magazine and a coupled state in which it is coupled to the master unit and can perform work, The master unit includes a rotation drive unit that rotationally drives a spindle shaft, and a clamp unit provided on the spindle shaft side. The clamp unit includes clamp balls, a cylindrical ball case having a ball holding hole that allows the tool connecting portion described below to enter and enables the spindle shaft to rotate inside, and that enables the clamp balls to move in a direction perpendicular to the axial direction of the spindle shaft, a cylindrical housing that has a receiving recess for receiving the clamp balls, is fitted outside the ball case, and is rotatable with respect to the ball case by the operation of the robot, and is provided with The ball case is provided with a locking portion formed in a concave or convex shape that restricts rotation of the ball case. In the housing, a lock member that can enter and exit the inside and outside of the housing and holds and releases the coupled state, and a biasing member that biases the lock member toward the tool unit side along the axial direction of the spindle shaft are provided. The receiving recess is formed as a recess extending from the inner peripheral surface to the outer peripheral surface of the housing. The tool unit is provided with a tool connecting portion that can be connected to the clamp unit. The tool connecting portion includes an insertion portion that is inserted into the clamp unit, and a flange portion that extends outward on the proximal end side of the insertion portion. The insertion portion is provided with an annular clamp groove that can engage with the clamp balls. The flange portion is formed in a concave or convex shape corresponding to the locking portion, and has a locked portion that locks with the locking portion to restrict rotation of the ball case, a lock release pin described below, and a lock hole into which the lock member can enter. and is provided with The tool magazine is provided with a storage recess for storing the tool unit. A positioning plate is arranged on the outer peripheral edge of the storage recess. The positioning plate is provided with a lock release pin that can enter the lock hole and releases the coupled state. The clamp unit The clamping ball is received in the receiving recess, and the tool connecting portion can be inserted into the clamping portion in a disengaged state, The clamping ball can be in contact with the inner peripheral surface of the housing and engage with the clamping groove, In the separated state, with the unlocking pin inserted into the locking hole of the flange portion of the tool unit, the tool unit is placed and held on the positioning plate, With the tool unit held by the positioning plate, by the operation of the robot, in the disengaged state, the insertion portion of the tool connecting portion is inserted into the clamping portion, the locking portion and the locked portion are locked, the housing is arranged at a position where the locking member is rotated by a predetermined angle from the locking hole, the locking member is rotated to the position of the locking hole and moved upward, so that the locking member enters the locking hole and the unlocking pin exits from the locking hole, the clamping portion becomes the engaged state, and the rotation of the housing is restricted to become the coupled state, From the coupled state, by the operation of the robot, the tool unit is moved to the storage recess and further moved downward, and by entering the unlocking pin into the locking hole, the locking member exits from the locking hole, the locking member is rotated by a predetermined angle from the locking hole and moved upward, so that the clamping portion changes from the engaged state to the disengaged state, and the restriction on the rotation of the housing is released to become the separated state, A tool changing mechanism characterized by the above.

2. The locking portion is a detent pin protruding from the ball case, The tool changing mechanism according to claim 1, wherein the locked portion is a detent hole into which the detent pin can be inserted.

3. The tool changing mechanism according to claim 1, wherein the length of the locking hole in the thickness direction is substantially the same as the length of the unlocking pin in the longitudinal direction.

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