JP6299391B2 - Tool changer - Google Patents

Description

  The present invention relates to a tool changer provided with a grip arm.

  A tool changer is a mechanism for exchanging tools between a tool magazine and a spindle of a machine tool. A tool magazine of a tool changer disclosed in Patent Literature 1 includes a magazine main body, a plurality of grip arms arranged radially around the periphery of the magazine main body, and a plurality of fulcrum stands that support each of the plurality of grip arms in a swingable manner. Etc. A plurality of fulcrum bases are fixed along the outer periphery of the magazine body, and the grip arm is pivotally supported. The grip arm is provided with a grip portion for gripping a tool or a tool holder at one end. The gripping portion includes a bifurcated portion for engaging a tool or a tool holder inward, and a pair of support mechanisms provided at a pair of tip portions of the bifurcated portion. The support mechanism includes a support pin that protrudes and retracts from the opening provided at one end of the cylindrical body toward the inside of the bifurcated portion. The cylindrical body houses a compression coil spring, and the compression coil spring urges the support pin to the outside of the cylindrical body. When a tool or tool holder enters from the outside to the inside of the bifurcated part during tool change, the support pin is pushed back by the outer peripheral surface of the tool or tool holder, and the tool or tool holder engaged inside the bifurcated part Grip.

JP 2013-202698 A

  When the support pin becomes defective due to the influence of the cutting fluid and the chips, the support pin does not retreat, so that the tool or the tool holder cannot easily enter or come out of the inside of the bifurcated portion. When the tool or the tool holder strongly presses the support pin, an excessive load is applied to the grip arm, and the grip arm may be damaged.

  An object of the present invention is to provide a tool changer capable of normally holding a tool or a tool holder even when a support pin becomes defective.

  A tool changer according to a first aspect of the present invention is a magazine main body that is provided on a column that supports a spindle head that rotatably supports a spindle of a machine tool so as to move up and down, and that can be rotated and indexed about one axis. A plurality of grip arms provided radially on the outer periphery of the magazine body and having a grip portion at one end for gripping a tool or tool holder attached to the spindle, and between the one end and the other end of the grip arm. And a fulcrum base fixed to the outer periphery of the magazine main body, and the gripping portion is close to the main shaft when the gripping arm that is indexed by rotation swings around the fulcrum base. In the tool changer that reciprocates between a position and a retracted position that is separated from the main shaft, the gripping portion includes a bifurcated portion that engages the tool or the tool holder inward, and the two A support mechanism that supports a rod-shaped support pin toward the inside of the bifurcated portion, the support mechanism is formed in a cylindrical shape, and the central axis is on the same axis. A cylindrical body that supports the support pin so that the support pin can be withdrawn and retracted from the opening at the ends facing each other, and is housed inside the cylindrical body, and the support pin faces the opening. A spring that biases the cylindrical body, a cylindrical body support portion that is provided at the end of the bifurcated portion, and that supports the cylindrical body so as to be movable parallel to the central axis, and the cylindrical body support portion And an elastic body that biases the cylindrical body toward the inner side of the bifurcated portion. For example, during machining of the workpiece, a gap between the opening of the cylindrical body and the support pin may be clogged with chips or the like, and the support pin may not be able to move out. In this case, when the tool or tool holder is inserted inside the bifurcated portion, the cylindrical body is pushed by the tool or tool holder via the support pin, but the elastic body arranged at a location different from the spring compresses, The cylindrical body retreats toward the outside of the bifurcated portion. Therefore, the tool changer can normally hold the tool or the tool holder even when the support pin becomes defective in operation, and can avoid damage to the grip arm.

  The tool changer according to a second aspect of the invention is characterized in that, in addition to the configuration of the first aspect, the elastic force of the elastic body is larger than the elastic force of the spring. Therefore, the tool changer can retract the cylindrical body to the outside of the bifurcated portion after the support pins cannot be retracted. That is, when the support pin is operating normally, the cylindrical body does not move. Further, the cylindrical body does not move even when the support pin is normally retracted from the opening.

  A tool changer according to a third aspect of the invention is characterized in that, in addition to the configuration of the invention according to the first or second aspect, the elastic body is a urethane member. Therefore, the tool changer can effectively apply an elastic force to the cylindrical body. Since the urethane member does not have a gap in itself, a good elastic force can be maintained even if chips or the like adhere.

  A tool changer according to a fourth aspect of the invention is characterized in that, in addition to the configuration of the invention according to the first or second aspect, the elastic body is a leaf spring. Therefore, the tool changer can easily and effectively give a strong elastic force to the cylindrical body.

  In addition to the structure of the invention according to any one of claims 1 to 4, the tool changer of the invention according to claim 5 is characterized in that the compression amount of the elastic body is the same as the compression amount of the spring. Features. Therefore, the tool changer can secure the amount of movement of the support pin even if the support pin falls out of the way.

  In addition to the structure of the invention according to any one of claims 1 to 5, the tool changer according to a sixth aspect of the invention is configured such that the elastic body is located inside the bifurcated portion in the cylindrical body support portion. It arrange | positions at the other end side opposite to the one end side which opposes, It is characterized by the above-mentioned. Since the elastic body can move the elastic body away from the tool or the tool holder side where the chips are scattered, it is possible to prevent the elastic force from being lowered due to the attachment of the chips or the cutting fluid.

1 is a perspective view of a machine tool 1. The right view of the tool change apparatus 20. FIG. The perspective view of the grip arm 30. FIG. The left view of the grip arm 30. FIG. FIG. 5 is a cross-sectional view taken along the line I-I in FIG. 4. The elements on larger scale around the right side support mechanism 45 shown in FIG. The figure which shows the state which the tool holder 101 approached into the inner side of the forked part 41 at the time of pin operation failure of the right side support mechanism 45. FIG. The elements on larger scale around the right side support mechanism 45 shown in FIG. The perspective view of the grip arm 130. FIG. FIG. 10 is a partially enlarged view around the left support mechanism 146 shown in FIG. 9. Sectional drawing of the left support mechanism 146 periphery. The partial enlarged view of the left support mechanism 246 periphery. Sectional drawing of the left support mechanism 246 periphery.

  A first embodiment of the present invention will be described with reference to the drawings. In the following description, the top, bottom, left and right, front and back indicated by arrows in the figure are used. The left-right direction, the front-rear direction, and the up-down direction of the machine tool 1 are the X-axis direction, the Y-axis direction, and the Z-axis direction of the machine tool 1, respectively. The direction of the tool changer 20 follows this. As shown in FIG. 1, the tool changer 20 is installed on the machine tool 1 for use.

  The structure of the machine tool 1 will be described with reference to FIG. The machine tool 1 includes a base 2, a machine body 3, a table 10, a tool changer 20, and the like. The base 2 is a substantially rectangular parallelepiped base made of iron. The machine body 3 is provided at the upper rear of the base 2 and cuts a work (not shown) held on the upper surface of the table 10. The table 10 is provided at the upper center of the base 2 and is movable in the X-axis direction and the Y-axis direction by an X-axis motor (not shown), a Y-axis motor (not shown), and a guide mechanism (not shown). The tool changer 20 is fixed to a frame 8 provided on the upper part of the machine main body 3, and the tool 4 mounted on the main shaft 9 of the machine main body 3 is exchanged with another tool.

  The structure of the machine body 3 will be described with reference to FIGS. The machine body 3 includes a column 5, a spindle head 7, a spindle 9, a control box 6, and the like. The column 5 is erected on the upper rear side of the base 2. The spindle head 7 can be moved up and down in the Z-axis direction along the front surface of the column 5, and supports the spindle 9 rotatably (see FIG. 2). The spindle 9 has a tool holder 101 mounted in a tapered hole 18 provided at the lower end. The tool holder 101 holds the tool 4. The spindle 9 rotates at high speed by driving a spindle motor 15 provided on the spindle head 7. The control box 6 stores a numerical control device (not shown). The numerical control device controls the operation of the machine tool 1.

  As shown in FIG. 2, the Z-axis moving mechanism includes a pair of Z-axis linear guides (not shown), a Z-axis ball screw 26, and a Z-axis motor (not shown). The Z-axis linear guide extends in the Z-axis direction and guides the spindle head 7 in the Z-axis direction. The Z-axis ball screw 26 is disposed between a pair of Z-axis linear guides and is rotatably provided by an upper bearing portion 27 and a lower bearing portion (not shown). The spindle head 7 includes a nut 29 on the back surface. The nut 29 is screwed into the Z-axis ball screw 26. The Z-axis motor rotates the Z-axis ball screw 26 in the forward and reverse directions. Therefore, the spindle head 7 moves in the Z-axis direction together with the nut 29.

  The internal structure of the spindle head 7 will be described with reference to FIG. The spindle head 7 rotatably supports the spindle 9 inside the lower front part. The main shaft 9 has a rotary shaft extending in the vertical direction, and is connected to a drive shaft of the main shaft motor 15 via a coupling 23. Therefore, the spindle 9 is rotated by the rotation drive of the spindle motor 15. The main shaft 9 includes a tapered hole 18, a holder clamping member 19, and a draw bar 69. The tapered hole 18 is provided at the tip (lower end) of the main shaft 9. The holder clamping member 19 is provided above the tapered hole 18. The draw bar 69 is provided by being coaxially inserted into a shaft hole passing through the center of the main shaft 9.

  The tool holder 101 holds the tool 4 on one end side, and includes a flange portion 102, a taper mounting portion 104, and a pull stud 105 on the other end side on the same axis. The flange portion 102 is formed in a substantially cylindrical shape whose diameter is increased radially outward from the base portion of the taper mounting portion 104, and includes a groove 103 extending in the circumferential direction on the outer peripheral surface. The taper mounting portion 104 is substantially conical. The pull stud 105 protrudes in the axial direction from the top of the taper mounting portion 104. The tapered mounting portion 104 and the pull stud 105 are inserted into the tapered hole 18. When the taper mounting portion 104 is mounted in the taper hole 18, the holder holding member 19 holds the pull stud 105. When the draw bar 69 presses the holder holding member 19 downward, the holder holding member 19 releases the pull stud 105.

  The spindle head 7 is provided with a crank lever 60 inside the rear upper part. The crank lever 60 is substantially L-shaped and can swing around a support shaft 61. The spindle 61 is fixed in the spindle head 7. The crank lever 60 includes a vertical lever 63 and a horizontal lever 62. The longitudinal lever 63 extends obliquely upward from the support shaft 61 to the column 5 side, bends upward at the intermediate portion 65, and further extends upward. The lateral lever 62 extends substantially horizontally from the support shaft 61 to the front of the column 5. The front end of the lateral lever 62 can be engaged from above with a pin 58 projecting perpendicularly to the draw bar 69. The vertical lever 63 includes a plate cam body 66 on the back surface of the upper end portion. The plate cam body 66 has a cam surface on the column 5 side. The cam surface of the plate cam body 66 can be brought into contact with and separated from a roller follower 67 fixed to the upper bearing portion 27. The roller follower 67 slides on the cam surface of the plate cam body 66. A tension coil spring (not shown) is provided between the longitudinal lever 63 and the spindle head 7. When the crank lever 60 is viewed from the right side, the tension coil spring constantly urges the crank lever 60 clockwise. Therefore, the crank lever 60 always releases the downward pressing of the pin 58 by the lateral lever 62.

  With reference to FIG. 2, the removal | desorption operation | movement of the tool holder 101 with respect to the taper hole 18 of the main axis | shaft 9 is demonstrated easily. In a state where the taper mounting portion 104 of the tool holder 101 is mounted in the taper hole 18 of the main shaft 9, the main shaft head 7 rises from the workpiece machining position on the table 10 (see FIG. 1). A plate cam body 66 provided on the crank lever 60 slides in contact with the roller follower 67. A grip portion 32 of the grip arm 30 to be described later grips the tool holder 101. The roller follower 67 slides along the cam shape of the plate cam body 66. The crank lever 60 rotates counterclockwise around the support shaft 61 when viewed from the right side. The lateral lever 62 engages with the pin 58 from above and presses the draw bar 69 downward. The draw bar 69 urges the holder holding member 19 downward. The holder clamping member 19 releases the pull stud 105. The spindle head 7 further rises to the ATC origin, and the tool holder 101 comes out of the tapered hole 18 of the spindle 9. Therefore, the tool holder 101 comes out of the tapered hole 18 of the main shaft 9.

  When the spindle head 7 reaches the ATC origin, the tool magazine 21 rotates based on the control command of the numerical controller, and the tool 4 specified by the control command of the NC program is determined at the tool change position. The tool change position is the lowest position of the tool magazine 21 and a position facing the spindle 9 in the vicinity. The tool 4 indexed to the tool change position is positioned below the spindle head 7 that has moved to the ATC origin.

  Next, the spindle head 7 descends from the ATC origin, and the tapered mounting portion 104 of the tool holder 101 that holds the tool 4 is inserted into the tapered hole 18 of the spindle 9. In a state where the taper mounting portion 104 of the tool holder 101 is inserted into the taper hole 18, the spindle head 7 is further lowered. The plate cam body 66 provided on the crank lever 60 slides on the roller follower 67. The roller follower 67 slides along the cam shape of the plate cam body 66. The crank lever 60 rotates clockwise around the support shaft 61 when viewed from the right side. Therefore, the lateral lever 62 is separated from the pin 58 to release the downward pressing of the draw bar 69. The draw bar 69 releases the downward bias of the holder holding member 19, and the holder holding member 19 holds the pull stud 105. The spindle 9 is mounted with a tool holder 101.

  The structure of the tool changer 20 will be described with reference to FIGS. The tool changer 20 includes a turret type tool magazine 21. The tool magazine 21 includes a disk-shaped magazine body 71 and a plurality of grip arms 30. The plurality of grip arms 30 are arranged along the outer periphery of the magazine body 71 at predetermined intervals, and are provided so as to be swingable in the front-rear direction of the tool magazine 21. The magazine support 95 is fixed to the frame 8. The magazine support 95 supports the support shaft 75 in a rotatable manner. The support shaft 75 extends obliquely downward with respect to the front of the machine tool 1. The support shaft 75 rotatably supports the magazine main body 71. The magazine main body 71 is arranged with the front facing the front of the machine tool 1.

  The structure of the magazine body 71 will be described. The magazine body 71 includes a boss portion 73 and a collar portion 72. The boss 73 is cylindrical. The support shaft 75 is inserted into the boss portion 73. The flange portion 72 is provided on the front end side of the outer peripheral surface of the boss portion 73 so as to be orthogonal to the axial direction. The boss 73 fixes the indexing disc 77 to the rear end. The indexing disc 77 has a plurality of cam followers (not shown) on the back side (surface facing the spindle head 7) with the support shaft 75 as the center. The plurality of cam followers are arranged corresponding to the respective positions of the plurality of grip arms 30.

  The reducer 96 is fixed to the upper part of the magazine support 95 and has a plurality of gears and a cam (not shown). The magazine motor 97 is fixed to the upper part of the speed reducer 96. The rotation shaft of the magazine motor 97 is connected to the speed reducer 96. The plurality of cam followers of the indexing disc 77 are fitted into cam grooves (not shown) formed in the cam of the speed reducer 96, respectively. Therefore, the indexing disc 77 can index one of the plurality of grip arms 30 and move to the lowest position of the magazine body 71.

  The collar portion 72 fixes a plurality of fulcrum stands 78 at predetermined intervals along the outer periphery of the back surface. The fulcrum stand 78 supports a later-described support shaft 33A of the grip arm 30. The flange portion 72 further fixes the plate-shaped guide members 80 at respective positions corresponding to the plurality of grip arms 30. The guide member 80 includes a guide surface 83. A steel ball 35 protruding from a rear end portion 34 described later of the grip arm 30 slides on the guide surface 83. Therefore, the grip arm 30 can swing stably in the front-rear direction of the tool magazine 21 around the fulcrum stand 78. The plate-shaped guide member 80 may be integrally formed in an annular shape.

  The structure of the grip arm 30 will be described with reference to FIGS. In addition, description of the structure of the grip arm 30 uses up and down, right and left, and front and back indicated by arrows in FIGS. The grip arm 30 includes a shaft portion 33, an arm body 31, a grip portion 32, a rear end portion 34, roller support portions 36 and 38, rollers 37 and 39, and the like. The shaft portion 33 has a substantially columnar shape extending in a substantially horizontal direction, and extends the support shaft 33A from the center of both axial end surfaces. The fulcrum stand 78 pivotally supports the support shaft 33A. The arm body 31 has an arm shape that extends from the shaft portion 33 in a direction orthogonal to the axial direction of the shaft portion 33 and has a gently curved front end. The grip portion 32 is provided at the front end portion of the arm body 31 in the extending direction, and grips the tool holder 101 in a detachable manner. The rear end portion 34 is formed in a bottomed cylindrical shape, and a compression coil spring (not shown) and a steel ball 35 are accommodated therein. The compression coil spring elastically holds the steel ball 35, and a part of the steel ball 35 moves out of the opening end of the rear end portion 34 according to the external bias.

  The roller support portion 36 is provided on the right side of the outer peripheral surface of the shaft portion 33, and supports the roller 37 obliquely upward on the front side. The roller support portion 38 is provided on the front upper side of the arm body 31 and in the vicinity of the left shaft portion 33, and supports the roller 39 obliquely upward on the front side. As shown in FIG. 2, in the grip arm 30 that is indexed to the tool change position of the tool changer 20 (the lowest position of the tool magazine 21), the roller 37 is fixed to the center of the floating head 12 in the horizontal direction on the front surface of the spindle head 7. Opposing the cam surface, the roller 39 opposes the cam surface of the swing cam 11 fixed along the right end portion of the front surface of the spindle head 7.

  As shown in FIG. 2, the cam surface of the swing cam 11 has a shape that extends linearly from the upper part to the lower part and is gently inclined obliquely rearward from the middle. As the roller 39 slides on the cam surface of the swing cam 11, the grip arm 30 swings. The cam surface of the floating cam 12 has a shape that gently slopes forward from the top to the center and gently slopes backward from the center to the bottom. Since the floating cam 12 has a built-in compression coil spring (not shown), when the roller 39 slides on the swing cam 11, the movement of the grip arm 30 is restricted so that the roller 39 and the swing cam 11 are not separated. Therefore, since the gentle inclination coincides with the movement locus of the roller 37 when the grip arm 30 swings, the grip arm 30 swings stably when the roller 37 slides on the cam surface of the floating cam 12. it can.

  The structure of the holding part 32 will be described with reference to FIGS. The grip portion 32 includes a bifurcated portion 41, a right support mechanism 45, a left support mechanism 46, and the like. The bifurcated portion 41 is formed in a bifurcated shape in plan view at the front end portion in the extending direction of the arm body 31, and the front end is open. The bifurcated portion 41 has an inner peripheral surface that is curved in a semicircular shape in plan view, and a pair of engaging ribs 42 and the like are provided at the center of the inner peripheral surface. The pair of engaging ribs 42 protrude toward the inside of the bifurcated portion 41. When the tool holder 101 enters the inside of the bifurcated portion 41, the pair of engaging ribs 42 engage with grooves 103 (see FIGS. 2 and 5) provided in the flange portion 102 of the tool holder 101.

  The right support mechanism 45 is provided orthogonal to one end portion of the bifurcated portion 41 that extends to the right front side, and elastically supports the support pin 90 so as to be retracted toward the inside of the bifurcated portion 41. The left-side support mechanism 46 is provided orthogonal to the other end extending to the left front of the bifurcated portion 41, and elastically supports the support pin 90 so as to be able to withdraw and retract toward the inside of the bifurcated portion 41. Therefore, the support pin 90 supported by the right support mechanism 45 and the support pin 90 supported by the left support mechanism 46 face each other and can support the flange portion 102 of the tool holder 101.

  The structure of the right support mechanism 45 will be specifically described with reference to FIG. The left side support mechanism 46 has the same structure as the right side support mechanism 45, and thus description thereof is omitted. The right support mechanism 45 includes an outer cylinder portion 47, an inner cylinder portion 51, a cylindrical body 52, a compression coil spring 59, a support pin 90, a urethane washer 85, and the like.

  The outer cylindrical portion 47 is provided integrally with one end portion that extends to the right front of the bifurcated portion 41 and is formed in a substantially cylindrical shape that extends in a direction orthogonal to the one end portion. In the following description, one end side of the outer cylinder portion 47 facing the inner side of the bifurcated portion 41 is referred to as a front end side of the outer cylinder portion 47, and the other end side on the opposite side is referred to as a rear end side. The orientation of other parts shall follow this.

  The inner cylinder portion 51 includes a cylinder portion 51A and a flange portion 51B. The cylindrical portion 51 </ b> A is formed in a substantially cylindrical shape having a smaller diameter than the outer cylindrical portion 47, and is inserted and fixed inward from the distal end side of the outer cylindrical portion 47. The rear end of the cylinder portion 51A is flush with the rear end of the outer cylinder portion 47. The flange portion 51 </ b> B is provided to extend radially outward from the distal end portion of the cylindrical portion 51 </ b> A, and is fixed in close contact with the opening end on the distal end side of the outer cylindrical portion 47. The inner cylinder portion 51 is used to improve the slidability between the inner peripheral surface of the outer cylinder portion 47 and the cylindrical body 52.

  The cylindrical body 52 has a cylindrical portion 52A and a flange portion 52B. The cylindrical portion 52 </ b> A is formed in a substantially cylindrical shape having a smaller diameter than the inner cylindrical portion 51 and a longer axial length than the inner cylindrical portion 51. The cylindrical portion 52A includes an opening 44, a pin support hole 53, a stepped portion 54, and a bottom plate 74. Each cylindrical portion 52A is disposed at a position where the central axis is on the same axis. Each cylindrical portion 52 </ b> A has an opening 44 at a portion facing each other, and the support pin 90 protrudes from the opening 44. The pin support hole 53 penetrates along the axial direction of the cylindrical portion 52A. The stepped portion 54 is provided at a position shifted to the opening 44 side from the central portion in the axial direction of the inner peripheral surface forming the pin support hole 53, and is formed by reducing the diameter inward in the radial direction. The bottom plate 74 is formed in an annular shape and is provided on the rear end side of the cylindrical portion 52 </ b> A, thereby serving as the bottom portion of the pin support hole 53. A cylindrical collar 64 is attached from the step portion 54 to the opening portion 44 in the pin support hole 53. The collar 64 is used to close the gap between the opening 44 and a support pin 90 described later, and to improve the slidability between the inner peripheral surface of the opening 44 and the support pin 90.

  The annular flange portion 52B is provided so as to extend outward in the radial direction at a position slightly spaced from the distal end portion to the rear end side of the cylindrical portion 52A. The diameter of the flange portion 52 </ b> B is shorter than the diameter of the flange portion 51 </ b> B of the inner cylinder portion 51. A urethane washer 85 described later is disposed between the flange portion 52B and the flange portion 51B of the inner cylinder portion 51. Therefore, the cylindrical body 52 does not come out from the inner side of the inner cylindrical part 51 toward the outer side of the bifurcated part 41.

  The cylindrical body 52 having the above structure is slidably inserted inward from the distal end side of the inner cylinder portion 51, so that the cylindrical body 52 is movable with respect to the outer cylinder portion 47. The rear end side of the cylindrical portion 52 </ b> A projects outward from the opening end on the rear end side of the outer cylindrical portion 47. The protruding portion includes an engagement groove 55 on the outer peripheral surface. The engaging groove 55 extends in the circumferential direction of the outer peripheral surface of the cylindrical portion 52A. The C-axis retaining ring 56 engages with the engaging groove 55 from the outside. The C-axis retaining ring 56 locked in the engaging groove 55 is locked to the rear end portion of the inner cylinder portion 51. Therefore, the cylindrical body 52 does not come out from the inner side of the inner cylindrical part 51 toward the inner side of the bifurcated part 41.

  The support pin 90 is formed in a rod shape. The tip of the support pin 90 that contacts the tool holder 101 is tapered. The support pin 90 includes a flange portion 91 on the outer peripheral surface on the rear end portion 92 side. The flange portion 91 extends outward in the radial direction. The rear end portion 92 projects rearward on the same axis from the center of the flange portion 91. The portion from the flange portion 91 to the rear end portion 92 of the support pin 90 is accommodated between the step portion 54 and the bottom plate 74 in the pin support hole 53. The flange portion 91 is locked to the stepped portion 54 from the rear end side of the cylindrical portion 52A. Therefore, the support pin 90 does not come out from the opening portion 44 of the cylindrical portion 52 </ b> A toward the inside of the bifurcated portion 41. The front end side of the support pin 90 protrudes from the opening 44.

  The compression coil spring 59 is accommodated in the pin support hole 53 of the cylindrical portion 52A. One end portion of the compression coil spring 59 is engaged with the flange portion 91 of the support pin 90 from behind. The rear end portion 92 of the support pin 90 is disposed inside one end portion of the compression coil spring 59. The other end of the compression coil spring 59 abuts a bottom plate 74 fixed to a C-axis retaining ring 57 that engages with an engagement groove formed in the inner surface of the pin support hole 53 from the inside. Therefore, the compression coil spring 59 can always bias the support pin 90 toward the opening 44. The amount of compression by the external bias of the compression coil spring 59 is the amount of movement of the support pin 90.

  The urethane washer 85 is a urethane washer formed in an annular shape, and is attached to the outer peripheral surface of the cylindrical portion 52 </ b> A of the cylindrical body 52. The urethane washer 85 is disposed between the flange portion 51B of the inner cylinder portion 51 and the flange portion 52B of the cylindrical body 52. The diameter of the urethane washer 85 is the same as the diameter of the flange portion 51B of the inner cylinder portion 51, and is larger than the diameter of the flange portion 52B of the cylindrical body 52. Therefore, even when the position of the cylindrical body 52 is shifted with respect to the inner cylindrical portion 51 due to dimensional errors or assembly errors of the parts, the flange portion 52B of the cylindrical body 52 can reliably contact the urethane washer 85. The elastic force of the urethane washer 85 is at least larger than the elastic force of the compression coil spring 59, and preferably 10 times or more that of the compression coil spring 59. For example, when the elastic force of the compression coil spring 59 is 6 N / mm, the elastic force of the urethane washer 85 may be adjusted to 95 N / mm.

  With reference to FIGS. 5 and 6, normal pin operations of the right support mechanism 45 and the left support mechanism 46 will be described. When the tool changer 20 attaches the tool holder 101 to the grip portion 32, the tool holder 101 enters from the front of the bifurcated portion 41 toward the inside. The flange portion 102 of the tool holder 101 abuts on the front end portion of the support pin 90 supported by the right support mechanism 45 and the front end portion of the support pin 90 supported by the left support mechanism 46. As the tool holder 101 further enters the forked portion 41, the flange portion 102 pushes the two support pins 90 to the outside of the forked portion 41. Since the elastic force of the urethane washer 85 is larger than the elastic force of the compression coil spring 59, the compression coil spring 59 is compressed without compressing the urethane washer 85. Therefore, only the support pin 90 is retracted from the opening 44 of the cylindrical body 52, and the position of the cylindrical body 52 does not change. Therefore, the tool holder 101 can enter as far as the inner side of the bifurcated portion 41.

  When the tool holder 101 moves to the inner side of the bifurcated portion 41, the groove 103 of the flange portion 102 is engaged with the engaging rib 42 of the bifurcated portion 41. Each support pin 90 comes into contact with the flange portion 102 of the tool holder 101 so as to be sandwiched from both sides. Therefore, the holding part 32 can hold the tool holder 101 stably.

  When the tool holder 101 is removed from the grip portion 32, the pins operate on the right support mechanism 45 and the left support mechanism 46 in the same manner as when the tool holder 101 is mounted. Therefore, the tool changer 20 can normally remove the tool holder 101 from the grip portion 32 to the outside.

  The operation of the right support mechanism 45 and the left support mechanism 46 when the pins do not operate will be described with reference to FIGS. For example, during machining of the machine tool 1, when chips are clogged between the support pins 90 and the collar 64 at the opening 44 of the cylindrical body 52, the support pins 90 are caused by friction between the support pins 90 and the chips. Cannot retract and the pin becomes inoperable. When the tool changer 20 attaches the tool holder 101 to the grip portion 32 in this state, the tool holder 101 enters from the front to the inside of the bifurcated portion 41 in the same manner as described above. The flange portion 102 of the tool holder 101 abuts on the tip portion of the support pin 90 supported by the right support mechanism 45 and the tip portion of the support pin 90 supported by the left support mechanism 46, respectively.

  As the tool holder 101 further enters the inside of the bifurcated portion 41, the flange portion 102 tries to push out each support pin 90 to the outside of the bifurcated portion 41. However, since the support pin 90 does not retract, A predetermined pressure or more is applied to the urethane washer 85 through the cylindrical body 52. Since the flange portion 52B of the cylindrical body 52 compresses the urethane washer 85 toward the flange portion 51B of the inner cylindrical portion 51, the entire cylindrical body 52 supporting the support pin 90 retracts with respect to the tool holder 101. I do.

  In the retracting operation, the urethane washer 85 is compressed according to the approach distance of the tool holder 101 into the bifurcated portion 41. The difference between the thickness P before compression of the urethane washer 85 (see FIG. 6) and the thickness Q after compression (see FIG. 8) is the amount of compression of the urethane washer 85 and the amount of movement of the support pins 90. The compression amount of the urethane washer 85 during the retracting operation is adjusted in advance so as to be the same as the compression amount of the compression coil spring 59. Therefore, since the movement amount of the support pin 90 is the same as the movement amount of the support pin 90 during the retraction operation, the support pin 90 operates in the same manner as during normal operation during the retraction operation. 101 can be stably held.

  Since the retracting operation does not apply an excessive load to the bifurcated portion 41, the arm main body 31, and the like, it is possible to reliably avoid the grip arm 30 from being damaged. When the tool holder 101 moves to the back of the bifurcated portion 41, the groove 103 of the flange portion 102 is engaged with an engaging rib 42 provided inside the bifurcated portion 41. Each support pin 90 comes into contact with the flange portion 102 of the tool holder 101 so as to be sandwiched from both sides. Therefore, the tool changer 20 can securely attach the tool holder 101 to the grip portion 32 even if the pin does not operate.

  Even when the tool holder 101 is removed from the grip portion 32, the right support mechanism 45 and the left support mechanism 46 can perform the retreat operation in the same manner as when the pins are not operated. Therefore, the tool changer 20 can normally remove the tool holder 101 from the grip portion 32 to the outside.

  As described above, the tool changer 20 according to the first embodiment includes the plurality of grip arms 30 on the outer periphery of the magazine body 71. The grip portion 32 of the grip arm 30 includes a bifurcated portion 41, and a right support mechanism 45 and a left support mechanism 46 are provided at each of the left and right ends of the bifurcated portion 41. The right-side support mechanism 45 and the left-side support mechanism 46 are mechanisms that support the rod-like support pins so as to be retractable toward the inside of the bifurcated portion 41. The right support mechanism 45 and the left support mechanism 46 include at least an outer cylinder portion 47, a cylindrical body 52, a support pin 90, a compression coil spring 59, and a urethane washer 85. The outer cylinder portion 47 is provided integrally and orthogonally to the left and right tip portions of the bifurcated portion 41. The cylindrical body 52 is provided inside the outer cylindrical portion 47 so as to be movable via the inner cylindrical portion 51. The cylindrical body 52 supports the support pin 90 so that it can be withdrawn and retracted from the opening 44 provided on the tip side facing the inside of the bifurcated portion 41. The compression coil spring 59 is housed inside the cylindrical body 52 and biases the support pin 90 toward the opening 44. The urethane washer 85 is attached to the outer peripheral surface of the cylindrical body 52 and is disposed between the flange portion 51B of the inner cylindrical portion 51 and the flange portion 52B of the cylindrical body 52.

  In the normal pin operation of the right support mechanism 45 and the left support mechanism 46, when the tool holder 101 enters from the front of the bifurcated portion 41 toward the inside, the tip of the support pin 90 supported by the right support mechanism 45 and the left side The tips of the support pins 90 supported by the support mechanism 46 come into contact with the flanges 102 of the tool holder 101, respectively. When the tool holder 101 further enters the inside of the bifurcated portion 41, the flange portion 102 pushes each support pin 90 to the outside of the bifurcated portion 41, so that the compression coil spring 59 is compressed. The support pin 90 is retracted from the opening 44 of the cylindrical body 52. When the tool holder 101 moves to the back of the bifurcated portion 41, the groove 103 of the flange portion 102 engages with an engaging rib 42 provided inside the bifurcated portion 41. Each support pin 90 abuts so as to sandwich the flange portion 102 of the tool holder 101 from both sides. Therefore, the tool changer 20 can securely attach the tool holder 101 to the grip portion 32.

  During workpiece machining by the machine tool 1, for example, in the right support mechanism 45, chips and the like are clogged in the gap between the opening 44 of the cylindrical body 52 and the support pin 90, and the support pin 90 falls into an unmovable state. When the tool holder 101 enters the bifurcated portion 41, the tool holder 101 presses the cylindrical body 52 outward via the support pins 90. Since the compression coil spring 59 is not compressed due to a malfunction of the support pin 90, the urethane washer 85 disposed at another location is compressed. Therefore, the entire cylindrical body 52 that supports the support pin 90 is retracted from the tool holder 101, and the tool changer 20 can normally hold the tool holder 101 and avoid damage to the grip arm 30.

  Further, in the first embodiment, the elastic force of the urethane washer 85 is larger than the elastic force of the compression coil spring 59. Therefore, after the support pin 90 can no longer be withdrawn / retracted, the urethane washer 85 is compressed, and the cylindrical body 52 can retreat toward the outside of the bifurcated portion 41. That is, when the support pin 90 is operating normally, the cylindrical body 52 does not move. Further, the cylindrical body 52 does not move even while the support pin 90 is normally retracted from the opening 44. That is, the compression coil spring 59 and the urethane washer 85 are not compressed at the same time, and only one of them is compressed, so that it is possible to prevent the support pin 90 from retreating more than necessary.

  Further, in the first embodiment, the urethane washer 85 can effectively impart an elastic force. Since the urethane washer 85 is made of urethane and does not have a gap in itself, it can retain a good elastic force even if chips or the like adhere to it.

  In the first embodiment, the compression amount of the urethane washer 85 during the retraction operation is further adjusted to be the same as the compression amount of the compression coil spring 59 during the normal pin operation. Therefore, the tool changer 20 can reliably secure the amount of movement of the support pin 90 even when the support pin 90 is unable to move out.

  A second embodiment of the present invention will be described with reference to FIGS. The tool changer of the second embodiment includes a grip arm 130 shown in FIG. 9 instead of the grip arm 30 (see FIG. 3) of the first embodiment. The grip portion 132 of the grip arm 130 includes a right support mechanism 145 and a left support mechanism 146. The right side support mechanism 45 and the left side support mechanism 46 of the first embodiment include a urethane washer 85 as an example of the elastic body of the present invention. The right side support mechanism 145 and the left side support mechanism 146 of the second embodiment are a urethane washer. Instead of 85, a wave washer 185, which is a kind of leaf spring, is provided. The structure other than the provision of the wave washer 185 is common to the first embodiment. Therefore, the parts common to the first embodiment are denoted by the same reference numerals, description thereof is omitted, and different parts will be mainly described.

  As shown in FIGS. 10 and 11, the wave washer 185 is attached to the outer peripheral surface of the cylindrical portion 52 </ b> A of the cylindrical body 52, and between the flange portion 51 </ b> B of the inner cylindrical portion 51 and the flange portion 52 </ b> B of the cylindrical body 52. To place. The wave washer 185 is formed by bending a flat washer made of spring steel into a corrugated shape, and is a well-known one that functions as a spring by being crushed. Like the urethane washer 85 of the first embodiment, the elastic force of the wave washer 185 is at least larger than the elastic force of the compression coil spring 59, and preferably 10 times or more that of the compression coil spring 59. Furthermore, the compression amount of the wave washer 185 during the retracting operation may be adjusted to be the same as the compression amount of the compression coil spring 59 during the operation of the normal pin, as in the first embodiment. Since the wave washer 185 can easily and effectively impart a strong elastic force to the cylindrical body 52, the retraction operation when the pin cannot be operated can be performed as in the first embodiment.

  A third embodiment of the present invention will be described with reference to FIGS. The right side support mechanism 45 and the left side support mechanism 46 of the first embodiment dispose a urethane washer 85 on the distal end side of the outer cylinder portion 47 (see FIG. 6). The right side support mechanism (not shown) and the left side support mechanism 246 of the third embodiment are arranged with a urethane washer 285 (see FIG. 13) on the rear end side of the outer cylinder part 247 opposite to the inside of the bifurcated part 41. And it is characterized in that it is housed inside the outer cylinder portion 247. Since the left side support mechanism 246 has a part of the same structure as the left side support mechanism 46 of the first embodiment, common parts are denoted by the same reference numerals, description thereof is omitted, and different parts are mainly described.

  With reference to FIG. 13, the structure of the left support mechanism 246 will be specifically described. Since the right support mechanism has the same structure as the left support mechanism 246, the description thereof is omitted. The left support mechanism 246 includes an outer cylinder part 247, an inner cylinder part 251, a cylindrical body 252, a compression coil spring 59, a support pin 90, a collar 64, a urethane washer 285, and the like. The compression coil spring 59, the support pin 90, and the collar 64 have the same shape as in the first embodiment.

  The outer cylinder part 247 is provided integrally with one end part extending to the left front of the bifurcated part 41, and is formed in a substantially cylindrical shape extending in a direction orthogonal to the one end part. In the following description, one end side of the outer cylinder portion 247 facing the inner side of the bifurcated portion 41 is referred to as a front end side of the outer cylinder portion 247 and the other end side opposite thereto is referred to as a rear end side. The orientation of other parts shall follow this. The outer cylinder part 247 is provided with a notch 247A having an L-shaped cross section at the inner peripheral edge of the opening end on the rear end side. The inner cylinder part 251 has a substantially cylindrical shape with a smaller diameter than the outer cylinder part 247 and is inserted and fixed inward from the distal end side of the outer cylinder part 247.

  The cylindrical body 252 has a cylindrical portion 252A and a flange portion 252B. The cylindrical portion 252A is formed in a substantially cylindrical shape having a smaller diameter than the inner cylindrical portion 251 and a longer axial length than the inner cylindrical portion 251. The cylindrical portion 252A includes the same opening 44, pin support hole 53, stepped portion 54, bottom plate 74, C-axis retaining ring 57, collar 64, and the like as in the first embodiment. The flange portion 252B extends outward in the radial direction at a position slightly spaced from the rear end portion toward the front end side on the outer peripheral surface of the cylindrical portion 252A. The flange portion 252B is engaged with the inner end surface (a surface parallel to the direction orthogonal to the axial direction) of the notch portion 247A provided on the rear end side of the outer cylinder portion 247 and the rear end portion of the inner cylinder portion 251. . Therefore, the cylindrical body 252 does not come out from the inner cylindrical portion 251 toward the inside of the bifurcated portion 41. Since the cylindrical body 252 is slidably inserted inward from the rear end side of the inner cylindrical portion 251, the cylindrical body 252 is movable in the axial direction with respect to the outer cylindrical portion 247. The rear end side of the cylindrical portion 252A protrudes outward from the opening end on the rear end side of the outer cylindrical portion 247.

  The annular urethane washer 285 is disposed inside a notch 247A provided at the rear end of the outer cylinder 247. The urethane washer 285 movably inserts the rear end side of the cylindrical portion 252A of the cylindrical body 252 into the hole inside thereof, and is in close contact with the rear end surface of the flange portion 252B. The annular holding washer 256 is inserted and fixed to the rear end portion of the outer cylinder portion 247. For example, caulking or the like can be employed as the fixing method. On the rear end side of the cylindrical portion 252A, a hole inside the pressing washer 256 is inserted so as to be movable. Since the flange portion 252 </ b> B abuts against the pressing washer 256 via the urethane washer 285, the tubular body 252 does not come out from the inside of the inner tube portion 251 toward the outside of the bifurcated portion 41. The pressing washer 256 presses the urethane washer 285 housed inside the notch 247 </ b> A from the rear end side of the cylindrical body 252. Therefore, the urethane washer 285 does not fall off from the outer cylinder portion 247. In addition, the arrangement | positioning location of the support pin 90, the compression coil spring 59, and the collar 64 is the same as 1st Embodiment. The elastic force and compression amount of the urethane washer 285 are the same as in the first embodiment.

  In the left-side support mechanism 246, when a chip or the like is clogged in the gap between the opening 44 of the cylindrical body 252 and the support pin 90, and the support pin 90 becomes unable to be withdrawn and retracted, a tool holder (not shown) is attached to the bifurcated portion 41. ) Enters, the tool holder presses the cylindrical body 252 outward through the support pins 90. Since the compression coil spring 59 cannot be compressed, a load is applied to the urethane washer 285 and the urethane washer 285 is compressed. Therefore, the entire cylindrical body 252 that supports the support pin 90 is retracted from the tool holder. Therefore, the tool changer of the third embodiment can avoid breakage of the grip arm as in the first and second embodiments.

  Furthermore, the left side support mechanism 246 can obtain the same function and effect as those of the first and second embodiments, and the rear end side of the outer cylinder portion 247 that is the side opposite to the inner side of the bifurcated portion 41 of the urethane washer 285. And housed inside the outer cylinder 247 (see FIG. 12), it is possible to prevent chips or cutting fluid from adhering to the urethane washer 285. Therefore, the third embodiment can prevent the urethane washer 285 from being damaged or deteriorated when the urethane washer 285 is attached with chips or cutting fluid.

  In the above description, the right support mechanism 45 and the left support mechanism 46 of the first embodiment, the right support mechanism 145 and the left support mechanism 146 of the second embodiment, and the right support mechanism and the left support mechanism 246 of the third embodiment are This corresponds to the support mechanism of the present invention. The outer cylinder portion 47 of the first and second embodiments and the outer cylinder portion 247 of the third embodiment correspond to the cylindrical body support portion of the present invention. The compression coil spring 59 corresponds to the spring of the present invention.

  The present invention is not limited to the above embodiment, and various modifications can be made. In the first embodiment, the urethane washer 85 is used as an elastic body that is compressed when the right support mechanism 45 (and the left support mechanism 46) is retracted. However, any material having elasticity may be used. Not limited. Furthermore, a resin material formed of a plurality of materials may be used. Furthermore, the elastic body does not have to be a washer shape. For example, in FIG. 6, one or a plurality of elastic body pieces are arranged between the flange portion 51 </ b> B of the inner cylinder portion 51 and the flange portion 52 </ b> B of the cylindrical body 52. May be.

  In the right support mechanism 45 (and the left support mechanism 46) of the first embodiment, the inner cylinder portion 51 and the collar 64 may be omitted. The same applies to the second and third embodiments.

  In the second embodiment, the wave washer 185 is used as an elastic body that is compressed during the retracting operation of the right support mechanism 145 (and the left support mechanism 146). However, a plate spring may have another washer shape. May be. For example, one or a plurality of leaf springs that bend at least at one location may be disposed between the flange portion 51B of the inner cylinder portion 51 and the flange portion 52B of the cylindrical body 52. Furthermore, the number of peaks of the wave washer 185 may be changed according to the elastic force required for the wave washer 185 in relation to the compression coil spring 59.

  Moreover, in the said 3rd Embodiment, although the urethane washer 285 is arrange | positioned at the rear end side of the outer cylinder part 247 on the opposite side to the inner side of the bifurcated part 41, it should just be a material which has elasticity, for example, a wave A leaf spring such as a washer may be disposed. In addition, when the wave washer is disposed on the rear end side of the outer tube portion 247, the amount of chips adhering to the wave washer can be reduced compared to the second embodiment, so that the expansion and contraction operation of the wave washer can be favorably maintained. . Further, the urethane washer 285 may be exposed to the outside.

  Moreover, in the said 1st-3rd embodiment, although the holding part of a grip arm hold | grips the tool holder 101, you may hold | grip the tool with which the tool and the tool holder were united.

DESCRIPTION OF SYMBOLS 1 Machine tool 30 Grip arm 32 Gripping part 41 Forked part 45 Right side support mechanism 46 Left side support mechanism 47 Outer cylinder part 52 Cylindrical body 59 Compression coil spring 78 Supporting stand 85 Urethane washer 90 Support pin 130 Grip arm 145 Right side support mechanism 146 Left side support Mechanism 185 Wave washer 246 Left support mechanism 252 Tubular body 285 Urethane washer

Claims (6)

A column body that rotatably supports a spindle head that rotatably supports a spindle of a machine tool, a magazine body that is provided so as to be able to rotate and index around a single axis, and a radially outer periphery of the magazine body. A plurality of grip arms each having a gripping part for gripping a tool or tool holder to be mounted on the main shaft and the one end and the other end of the grip arm are pivotally supported and fixed to the outer periphery of the magazine body. The grip arm is pivoted about the fulcrum table, so that the gripping portion is positioned between a proximity position close to the main shaft and a retracted position separated from the main shaft. In the tool changer that reciprocates,
The gripping part is
A bifurcated portion for engaging the tool or the tool holder inside;
A pair of end portions of the bifurcated portion, respectively, provided with a support mechanism for supporting a rod-shaped support pin toward the inside of the bifurcated portion;
The support mechanism is
A cylindrical body that is formed in a cylindrical shape and that is disposed at a position where the central axis is on the same axis, and that supports the support pin so that it can be withdrawn and retracted from the opening at the end facing each other;
A spring that is housed inside the cylindrical body and biases the support pin toward the opening;
A cylindrical body support portion that is provided at the end of the bifurcated portion and supports the cylindrical body so as to be movable parallel to the central axis;
A tool changer comprising: an elastic body that urges the cylindrical body toward the inner side of the bifurcated portion with respect to the cylindrical body support portion.   The tool changer according to claim 1, wherein an elastic force of the elastic body is larger than an elastic force of the spring.   The tool changer according to claim 1, wherein the elastic body is a urethane member.   The tool changer according to claim 1, wherein the elastic body is a leaf spring.   The tool changer according to any one of claims 1 to 4, wherein the compression amount of the elastic body is the same as the compression amount of the spring.   The said elastic body is arrange | positioned in the said cylindrical body support part at the other end side opposite to the one end side which opposes the inner side of the said bifurcated part, The any one of Claim 1 to 5 characterized by the above-mentioned. Tool changer.

Images