JP5057943B2 - Tool changer - Google Patents

Description

  The present invention relates to a tool changer for changing a tool by turning an exchange arm having a tool gripping portion.

  A tool changer provided in a machine tool includes a tool change arm that performs a reciprocating operation in the axial direction of a main shaft of the machine tool and a turning operation around an axis parallel to the axis of the main shaft. This tool exchange arm includes a pair of grip portions for gripping the tool at both ends. There are various types of drive mechanisms for the tool changer arm that reciprocate in the axial direction and swivel around the axis.For example, a rack and pinion mechanism that converts linear motion of a cylinder as a drive source into rotational motion, and A device including a ball screw feed mechanism that converts a rotational motion of a motor into a linear motion is known.

  When changing tools, the tool holder is removed from the main spindle of the machine tool at one grip of the replacement arm, the replacement arm moves linearly downward, away from the main spindle, and the replacement arm turns 180 ° for replacement. After the arm linearly moves upward in the direction approaching the main shaft, the tool holder held by the other grip portion of the replacement arm is attached to the main shaft of the machine tool.

  As a conventional example of the tool changer, those disclosed in Patent Documents 1 and 2 are known. According to paragraph [0010] of Patent Document 1, “the arm shaft 2 is supported so that it can freely rotate around the central longitudinal axis. The arm shaft 2 rotates around the longitudinal axis of the arm shaft 2. The first cylindrical member 3 that is movably supported is a pinion that engages with an actuator fixed to the main body 6 of the apparatus of this embodiment that can be attached to a machine tool, for example, a rack 9 connected to a hydraulic cylinder 8 (particularly, (Not shown) is installed, and a predetermined rotational movement can be performed by the operation of the hydraulic cylinder 8. " Similarly, paragraph [0011] of Patent Document 1 states that “the second cylindrical member 4 enclosing the first cylindrical member 3 is fixedly connected to the main body 6 of the apparatus of the present embodiment. The member 3 and the second cylindrical member 4 are described as having a first cylindrical cam groove 13 and a second cylindrical cam groove 14 formed on the outer periphery thereof based on respective predetermined cam curves.

  Further, paragraph number [0024] of Patent Document 2 describes that “the above series of operations are performed by mechanical power transmission via the first mechanism and the second mechanism by driving one driving unit”. ing. Similarly, paragraph number [0028] of Patent Document 2 states that “the tool changer makes a standby swiveling of the swivel shaft 14 by the rotation of the first indexing shaft 25 when the rotation of the second indexing shaft 26 is stopped. Operation, gripping / holding release operation of the tool 8 by the tool gripping unit 12, holding / holding release operation of the tool 8 with respect to the main shaft 7 and the standby pot 15, and reversal turning operation of the turning shaft 14 for reversing the position of the tool 8 are performed. And a reciprocating motion of the revolving shaft 14 in the axial direction by the rotation of the second indexing shaft 26 when the rotation of the first indexing shaft 25 is stopped. A second mechanism for carrying out the movement by mechanical power transmission is provided. "

  The tool changer of Patent Document 1 operates the change arm by a so-called cylindrical cam method, and the tool changer of Patent Document 2 operates the change arm by a so-called link connection method. Although the method of operating is different, both are common in that the exchange arm is operated by one drive source.

Japanese Patent Laid-Open No. 7-136887 JP 2003-266264 A

  In the field of processing machines, there is a request to shorten the tool change time in order to shorten the processing cycle time, in addition to the request to make the tool changer compact. In response to the former request, it is effective to adopt a configuration in which the tool changing arm is operated by one drive source. The latter requirement is a requirement for improving productivity. In order to shorten the operation time of the tool change arm, it is necessary to operate the tool change arm at a high speed. This is because, in machining by a machining center, several tens of types of tools may be used before the machining is completed, and the accumulated tool change time becomes a time that cannot be ignored even if the time is slightly reduced. However, there is a concern that if the tool change arm is operated at a high speed while the tool is gripped by the pair of grip portions of the tool change arm, the centrifugal force increases and the possibility that the tool will come off the grip portion increases. .

  The present invention can reliably grip the tool so that the tool does not come off from the grip part during the operation of the tool change arm, and conversely, can allow the tool to come off from the grip part when the tool change arm stops. Thereby, it aims at providing the tool change apparatus which can improve the attachment or detachment reliability of the tool by a tool change arm.

  In order to achieve the above object, according to the present invention, in a tool changer for changing a tool by turning an exchange arm having a tool gripping portion, in a direction parallel to a plane perpendicular to the turning axis of the exchange arm. A grip rod that is provided on the exchange arm so as to be able to reciprocate, and a cylinder that is attached to the exchange arm and is supported so as to be rotatable around the swivel axis with a cam groove formed on the outer peripheral surface. A member, a cam follower that engages with the cam groove, is moved in a direction parallel to the turning axis, and the cylindrical member is rotated, and the grip is moved to the center of the cylindrical member in the turning axis. A shaft that is provided to prevent and allow reciprocal movement of the rod and has a pin that protrudes into the cam groove and engages with the cam follower; and Tool changer comprising a biasing means, the urging to a position that prevents the reciprocating movement is provided.

  According to the tool changer of the present invention, the shaft for restricting the reciprocating movement of the grip rod is disposed inside the cylindrical member for rotating the tool changing arm, and this cylindrical member is engaged with the cam groove of the cylindrical member. The grip follower is allowed to reciprocate when the cam follower that rotates the shaft engages with a pin provided on the shaft. Therefore, it is possible to hold the tool so that the tool does not come off from the grip part when the tool changing arm is swung, and it is allowed that the tool is detached from the grip part when the tool changing arm is stopped turning. The attachment / detachment reliability can be improved.

  Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows an embodiment of a tool changer according to the present invention. A tool changer 1 according to the present embodiment includes an apparatus main body 2 and a tool changer arm 3 and is provided between a spindle of a machine tool and a tool magazine. Since the tool change arm 3 is coupled to a cylindrical member 21 that is rotatably provided in the apparatus main body 2 in the longitudinal direction, the tool changing arm 3 rotates together with the cylindrical member 21.

  As shown in FIG. 2, grip portions 11 capable of gripping the tool 5 are formed at both ends of the tool exchange arm 3. The tool 5 includes a holder 6 and a tool main body (not shown). The holder 6 has a taper portion 7a attached to the spindle of the machine tool, and the base side of the taper portion 7a is gripped by the grip portion 11. The tool main body corresponds to a drill or a cutter, and is fixed to the end of the holder 6 by a fastening member. The grip part 11 has a semicircular shape. On the grip inner surface 12a of the grip portion 11, a convex portion 12b is formed along the circumferential direction of the grip inner surface 12a. This convex portion 12 b is adapted to engage with an annular groove 8 formed on the outer peripheral side surface of the tool 5. The annular groove 8 of the tool 5 is formed for gripping the tool 5 by the grip portion 11 of the tool exchange arm 3 or the like. The tool 5 is attached to the spindle by pulling a pull-stat 7b provided at the end with a predetermined force by a draw bar of the spindle of the machine tool.

  Further, one end of the tool changing arm 3 protrudes into and out of the gripping space 13 defined by each grip part 11, and one end abuts on the outer peripheral side surface (annular groove 8) of the tool 5 gripped by the grip part 11. And a grip rod 15 for preventing the tool 5 from being detached from the grip portion 11 (see FIG. 4). The grip rod 15 includes a cylindrical portion 17a fixed to the wall portion, a rod portion 17b inserted into the cylindrical portion 17a so as to be able to advance and retreat, and a coil spring that elastically supports the rod portion 17b inside the cylindrical portion 17a ( (Not shown).

  The rod portion 17b is always urged forward by a coil spring so that the tip protrudes into the gripping space 13. For this reason, when gripping the tool 5 with the grip portion 11, the rod portion 17b compresses the coil spring and the tip of the rod portion 17b is temporarily retracted. However, after gripping the tool 5 with the grip portion 17b, the rod portion 17 b is pushed forward by the coil spring, and the tip of the rod portion 17 b comes into contact with the outer peripheral side surface of the tool 5. As a result, the tool 5 is temporarily held by the grip portion 11, and the tool 5 is prevented from being detached from the grip portion 11. The spring constant of the coil spring is set to a predetermined value so that the detachability of the tool 5 is not impaired and the tool 5 does not fall off the grip portion 11.

  However, when the tool changing arm 3 is swung at a high speed, the centrifugal force increases, and there is a concern that the tool 5 may come off the grip portion 11. Therefore, in the present invention, the tool 5 is rotated when the tool changing arm 3 is rotated. A lock mechanism that prevents the movement of the grip rod 15 is provided to prevent the grip portion 11 from being detached. This locking mechanism will be described later.

  Next, the apparatus main body 2 will be described. The apparatus main body 2 is provided coaxially with the cylindrical member 21 inside the cylindrical member 21, a housing 20, a cylindrical member 21 connected to the central portion of the tool changing arm 3, a drive mechanism 22 that rotationally drives the cylindrical member 21. A shaft 23 that prevents the grip rod 15 from retreating and maintains the state in which the tool 5 is held by the grip portion 11.

  The housing 20 accommodates a cylindrical member 21, a shaft 23 disposed inside the cylindrical member 21, and a slider 24 having a cam follower 25 that engages with a cam groove 27 of the cylindrical member 21. A hydraulic cylinder 19 as a drive source is provided outside the housing 20.

  The cylindrical member 21 has a cam groove 27 with which the cam follower 25 engages on the outer surface, and is supported rotatably on the housing 20 via a bearing 26. One end of the cylindrical member 21 is connected to an intermediate portion of the tool change arm 3 by a fastening member. Since the cam follower 25 that is slidably engaged with the cam groove 27 is rotatable, the cam follower 25 and the cam groove 27 are in rolling contact with low friction.

  For convenience of explanation, FIG. 3 shows a state in which the outer surface of the cylindrical member 21 is partially developed, and the cam follower 25 is described so as to advance obliquely through the cam groove 27. Is moved in the axial direction (vertical direction) by the cylinder 19, so that the cylindrical member 21 is rotated. The cam groove 27 is formed so that the cylindrical member 21 rotates 180 degrees when the cam follower 25 moves from one end of the cam groove 27 to the other end. As a result, the tool 5 is exchanged between the spindle of the machine tool and the tool magazine.

  The shaft 23 has a restricting portion 30 that abuts the rear end of the grip rod 15 at the front end to prevent the grip rod 15 from retreating, and is an unlocking pin that is pressed by the cam follower 25 at one end and the other end of the cam groove 27. 31 and 32, and elastically supported by compression coil springs (elastic members) 33 and 34 that are always compressed at both ends. The upper compression coil spring 33 is disposed between the shaft 23 and the cylindrical member 21 at a position where it hits the lower surface of the restricting portion 30. The lower compression coil spring 34 is disposed between the shaft 23 and the cylindrical member 21 at a position where the lower compression coil spring 34 abuts on a bush 35 that is movably inserted on the shaft 23. The shaft 23 is provided so as to reciprocate in the axial direction when the lock release pins 31 and 32 are pushed by the cam follower 25. The restricting portion 30 has a plate shape and is disposed in the hole 18 in the middle portion of the tool change arm 3. As shown in FIG. 2, the pair of grip rods 15 are arranged in the diagonal direction of the restricting portion 30.

  The locking release pins 31 and 32 protrude from the outer peripheral surface of the shaft 23 in opposite directions and are spaced apart from each other in the axial direction of the shaft 23. The upper locking release pin 31 is movably disposed at the upper end of the cam groove 27 into the oval through hole 28, and the lower locking release pin 32 is inserted at the lower end of the cam groove 27 into an oval shape. The hole 29 is movably disposed.

  As shown in FIG. 4, when the locking release pins 31 and 32 are not pressed by the cam follower 25, the axial position of the shaft 23 so that the restricting portion 30 of the shaft 23 faces the rear end of the grip rod 15. Has come to be determined. Since the upper compression coil spring 33 has a smaller spring constant than the lower compression coil spring 34, the lower compression coil spring 34 is at the position where the bush 35 is pushed downward as much as possible, and the axial position of the shaft 23. Is fixed. This position of the shaft 23 is a position where the tool changing arm 3 is turning. As a result, the retracting of the grip rod 15 is prevented by the restricting portion 30 to be locked, and the tool 5 is prevented from being detached from the grip portion 11.

  As shown in FIGS. 3 and 5, when the cam follower 25 is linearly moved upward (the cylindrical member 21 rotates counterclockwise) and the locking release pin 31 located on the upper side is pressed by the cam follower 25, the lower compression coil While the spring 34 is compressed, the shaft 23 is pushed up together with the unlocking pin 31, and the reciprocating movement of the pair of grip rods 15 of the tool changing arm 3 is allowed. When the cam follower 25 is linearly moved downward from this state (the cylindrical member 21 rotates clockwise), the shaft 23 is moved downward by the spring force of the lower compression coil spring 34 and the grip rod 15 is retracted. The lock position is lowered to a position where it is blocked by the restriction portion 30.

  Further, as shown in FIG. 6, when the cam follower 25 is linearly moved downward and the locking release pin 32 positioned on the lower side is pressed by the cam follower 25, the upper compression coil spring 33 is compressed and the shaft 23 is engaged. The pair of grip rods 15 of the tool changing arm 3 are allowed to reciprocate by being pushed down together with the stop release pin 32. When the cam follower 25 is linearly moved upward from this state, the shaft 23 is moved upward by the spring force of the upper compression coil spring 33 and is moved up to a lock position where the retraction of the grip rod 15 is prevented by the restricting portion 30.

  As shown in FIGS. 5 and 6, the position where the reciprocating movement of the pair of grip rods 15 is allowed is a position where the turning of the tool exchange arm 3 is stopped (a position of 0 degree or 180 degrees). The tool 5 is attached to and detached from the spindle of the machine tool or the pot of the tool magazine.

  As described above, according to the tool changer 1 of the present embodiment, the cam follower 25 that engages with the cam groove 27 of the cylindrical member 21 and rotates the cylindrical member 21 protrudes from the outer peripheral surface of the shaft 23. The grip rod 15 is prevented from being retracted while being positioned between the unlocking pins 31 and 32, and the grip rod 15 is locked. This prevents the tool 5 from being detached from the grip portion 11 during the turning operation of the tool exchange arm 3. With the cam follower 25 pressing one of the locking release pins 31 and 32, the grip rod 15 is allowed to move backward, and the grip rod 15 is unlocked. As a result, the tool 5 is detached from the grip portion 11 when the tool changing arm 3 stops turning.

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the gist of the present invention.

It is sectional drawing of embodiment of the tool change apparatus which concerns on this invention. It is a top view of the tool exchange arm shown in FIG. It is a partial expanded view of the cylindrical member which has a cam groove engaged with a cam follower. It is explanatory drawing which shows the principal part of a tool change apparatus, and shows the state which the control part of the shaft is regulating the reciprocation of a grip rod. It is explanatory drawing which shows the principal part of a tool change apparatus, shows the state which the shaft moves to the axial direction upper direction, and the control part of the shaft is allowing the reciprocating movement of a grip rod. It is explanatory drawing which shows the principal part of a tool change apparatus, shows the state which the shaft moves to the axial direction downward, and the control part of the shaft is allowing the reciprocating movement of a grip rod.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Tool change apparatus 2 Apparatus main body 3 Tool change arm 11 Grip part 15 Grip rod 21 Cylindrical member 23 Shaft 25 Cam follower 27 Cam groove 30 Restriction part 31, 32 Lock release pin 33, 34 Compression coil spring

Claims (1)

In a tool changer for changing a tool by turning an exchange arm having a tool gripping part,
A grip rod that is provided in the exchange arm so as to be reciprocally movable in a direction parallel to a plane orthogonal to the swivel axis of the exchange arm, and grips a tool on the tool gripping portion;
A cylindrical member attached to the exchange arm and rotatably supported around the pivot axis, and having a cam groove formed on an outer peripheral surface;
Driving means for moving a cam follower engaged with the cam groove in a direction parallel to the pivot axis, and rotating the cylindrical member;
A shaft having a pin that moves in the direction of the pivot axis in the center of the cylindrical member to prevent reciprocation of the grip rod and is allowed, projects into the cam groove, and engages with the cam follower;
An urging means for urging the shaft to a position that prevents the grip rod from reciprocating. A tool changer comprising:

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