JP2007075924A - Tool changer of machine tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tool changer enabling highly accurate machining at high speed rotation by changing a thin tool by holding and elevating its straight shank part without using a tool holder. <P>SOLUTION: The tool 10 having a shank 10A of the same diameter comprises: a tool magazine 5 having a funnel shaped holding hole 5A for inserting and holding a cutting edge continuous to a shank tapered part 10B by facing the cutting edge downward; a holding claw 11 for holding and transferring the tool 10 between vertically facing spindle 3 and tool magazine 5 and contacting three points on plane and V-shape groove surface to hold the tool 10 by determining position and attitude of the straight shank part 10A; and a stopper bar means 12 elevating the tool 10 by inserting in a holding hole 5A determined from a lower side of the tool magazine 5 in parallel to the spindle 3, engaging with the shank tapered part 10B of the tool 10 and being provided with three stopping operation positions of a tool attaching/detaching position of the spindle 3, a clamping/unclamping position by the holding claw 11, and a position just under the holding hole 5A to return the tool 10 to the holding hole 5A. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a tool changer for exchanging and exchanging tools between a tool spindle of an NC machine tool and a tool magazine having a plurality of tool pots, and in particular, a feed axis system and a turning axis system of a machine tool. A tool shank consisting of a blade part followed by a shank part that does not have a tool holder, such as a so-called taper shank, is moved directly from the tool magazine to the tool spindle, and conversely from the tool spindle to the tool magazine. The present invention relates to a machine tool provided with a tool changer that transfers and exchanges tools by gripping and attaching.

In an automatic tool changer of a general NC machine tool, each tool is held by a tool holder having a taper shank and a tool attaching / detaching means, and the tool holder is exchanged between a spindle and a tool magazine.
For exchanging the tool holder between the tool spindle and the tool magazine of the above-mentioned machine, a tool that is usually used with an exchange arm means for gripping and attaching / detaching the tool holder is often used. There are also armless type tools or tool holder exchange types in which the tool spindle side is moved and positioned with respect to the target tool holder on the magazine side using an operation mechanism such as a feed axis system or a swivel axis system to perform detachment operation. Known (for example, refer to Patent Documents 1 and 2).

  Further, as described above, the tool is not gripped by the tool holder and the tool holder is replaced with the tool holder, but the tool is stored in advance in a tool pot provided in a plurality of tool magazines. There is also known a so-called holderless type tool changer that directly changes a tool with a tool spindle of a machine as it is. This latter type of tool changer is increasingly applied to NC machine tools that process a workpiece having a complicated shape such as a rib groove of a molding die using a relatively thin tool. .

  In the apparatus described in Patent Document 1, the positioning plate provided in the tool magazine is elastic in the positioning groove formed at a desired position of the intermediate shaft portion between the cutting blade portion of the tool and the spindle mounting portion. Engage and position the tool in a predetermined axial direction, and hold and store a plurality of tools in a tool pot arranged in parallel in the tool magazine, between the tool magazine and the main spindle of the NC machine tool. By relative movement, tools are exchanged and exchanged directly between all the tool pots of the tool magazine and the spindle of the NC machine tool.

  While this type of tool change method is convenient in terms of tool length management, depending on the shape of the workpiece, even with the same type and size of the same type of tool, the protruding size from the spindle (interference between the spindle and the workpiece) If you want to change the tool length to shorten the tool length or perform high-rigidity machining, you should prepare the same type of tool with positioning grooves in various locations on the intermediate shaft. There are inconveniences, such as having to be cut, the strength of the tool is reduced due to the engraving of the grooves, or the time for further engraving of the grooves is required.

  Therefore, the one described in the above-mentioned Patent Document 2 is such that the tool length can be arbitrarily and easily set without making a groove or the like in the tool shank, and an arbitrary position in the axial direction of the tool shank portion. A plurality of ring members fitted and fixed to the tool magazine, and a tool pot for storing the tool in the tool magazine using the ring members as a reference in the axial direction of the tool. Thus, the tool is changed by relative movement between the spindle and the tool magazine.

JP-A-5-277867 JP-A-8-174364

  In an automatic tool changer for general machine tools, a tool holder with a taper shank with a built-in attachment / detachment means for gripping and fixing the tool shank is interposed, so the runout accuracy depends on the holder accuracy, and tool change It was difficult to compensate for displacement due to variations in holder attachment at the time, and it was difficult to maintain high precision in finishing the fine dimensions and shape.

  In any case, in the above-mentioned Patent Documents 1 and 2, the tool exchanged and exchanged between the tool magazine and the tool spindle of the NC machine tool is composed of a spindle mounting shank portion and a cutting blade portion, and is tapered. In addition to a so-called tool holder-less tool change method such as a shank, a so-called armless tool change method for transferring and mounting the tool unit between the tool magazine and the tool spindle directly from the tool magazine to the spindle and mounting. However, the straight shank diameter described above is, for example, about 3.0 to 5.0 mm, and it is used by applying it to a tool changer for thin end mill tools and drill tools having a shank taper at the tip. However, there were still various problems.

  In the devices described in Patent Documents 1 and 2, since the tool change is an armless system, the normal tool spindle side is driven by an operation mechanism such as a feed axis system and a swivel axis system with respect to the tool change position on the tool magazine side. Although feed positioning is performed, the positioning accuracy is required to be considerably high. However, today, such a request for positioning accuracy can be dealt with normally and there are few problems.

  However, if the displacement due to thermal distortion caused by temporal and local temperature changes due to the installation and operating environment of such machine tools, date and time, seasonal fluctuations, etc. causes misalignment, the tool cannot be changed. There is a possibility.

  In particular, in the above-mentioned Patent Documents 1 and 2, the tool holder 14 provided in the tool magazine 12 for holding the tool 20 is formed of an elastic material, and the base 15 protrudes from the base 15 with a root. The tool 20 is grasped by an elastic force by the shaped holder fingers 16 (16a, 16b).

  In the latter, the tool magazine 27 is a plate made of an elastic material such as a resin, and eight tool spots 61 for storing the tool 1 are formed by seven slits 27a provided in the left-right direction. A groove portion 27b is formed in the middle of the upper and lower layers, and each tool spot 61 has a tool storage hole 27c having a diameter smaller than the diameter of the shank portion 1a of the tool 1 and the delivery of the tool 1. A pair of grips that open and close when elastically acted on when the tool 1 mounted on the main shaft 5 is stored in the tool storage hole 27c due to the movement of the main shaft 5 in the X-axis direction. The nail | claw 27e, 27e, the cutout hole 27f and the notch 27g which give elasticity to a pair of holding | grip claw 27e, 27e are each provided.

  As a result, the tool changer 10 described in both Patent Documents 1 and 2 removes the tools 20 and 1 by unclamping them from the main shafts 8 and 5 and removes them from the tool holders 14 or 27 of the tool magazines 12 and 27. Even if the tool spot 61 can hold the tool, the tool holders 14 of the tool magazines 12 and 27 or the tools 20 and 1 held in the tool spot 61 are shank 24 and 1a into the holes of the tool spindles 8 and 5, respectively. It is impossible to expect the automatic mounting operation of the tools 20 and 1 that require a high degree of positional accuracy such that the insertion is performed by the Z-axis lowering operation from the rear end side.

Therefore, the present invention is a mounting portion for a spindle of an NC machine tool, a straight shank portion for moving up and down, a shank taper portion engaging with a holding hole and a lifting bar, and a cutting blade portion and a gripping portion at the tip thereof. In a tool changer that transfers and exchanges a holderless tool equipped with a tool by moving the main spindle and tool magazine close to each other in the opposite Z-axis direction, the straight shank is gripped during the relative movement. By providing a gripping claw that positions the tool axis on the spindle axis and moves the tool up and down a minute distance to insert the shank tip into the spindle port, on the other hand, before and after the grip unclamping by the gripping claw, Stopper bar means for positioning and raising / lowering the tool in response to the tip of the lower blade portion of the tool is provided, and the relative moving means is assisted in place of the exchange arm means. This ensures that the tool can be changed as intended.

The object of the present invention is as follows. (1) A straight shank portion mounted on a tool spindle having a tool attaching / detaching means of a machine tool, a shank tapered portion connected to the shank portion, and a cutting blade at the tip of the tapered portion. In a tool changer for exchanging and exchanging a plurality of tools having a section between the tool spindle and a tool magazine,
The plurality of tools have their straight shanks having the same shaft diameter, and the tool is inserted in the vertical direction parallel to the tool spindle with the cutting edge facing downward from the shank base to the cutting edge. A tool magazine provided with a funnel-shaped holding hole for receiving a tool having a shank taper portion that is tapered into a taper shape;
The used tool is picked up from the tool spindle and transferred to an empty holding hole in the tool magazine, and the tool to be used next is picked up from the holding hole in the indexed tool magazine and the tip of the shank is moved to the tool. A gripping claw provided between a tool spindle and a tool magazine for grasping and transferring the shank base of the tool for insertion into the spindle port, wherein the cylindrical shank of the tool is held between the shank and the spindle port. A pair of gripping claws in which a V-shaped groove is provided on the other gripping surface that is associated with the clamp while one gripping surface is flat so as to provide three-point support for projecting the core;
Tools indexed from under the tool magazine for transferring the tool from the tool holding hole of the tool magazine to the tool attaching / detaching means of the spindle and for transferring the tool from the tool attaching / detaching means of the spindle to the tool holding hole of the tool magazine. Stopper bar means that is inserted into the holding hole in parallel with the main shaft, engages with the shank taper portion of the tool and moves the tool up and down, and the tip of the stopper bar has a tip of the tool when the tool is mounted on the tool main shaft. The stopper bar means has three stop operation positions: a position of the shank taper portion, a position immediately below the indexed holding hole of the tool magazine, and a predetermined intermediate position between the two positions. This is achieved by providing an automatic tool changer for a machine tool.

  The purpose of the wave of the present invention is as follows. (2) The tool attaching / detaching means for the tool spindle is a collet tightening / loosening means for the tool shank, shrink fitting collet, or tightening / loosening means for the main shaft hole of the elastic deformation application type. It is achieved by using the tool changer according to claim 1 which is any one.

  The object of the present invention described above is (3) measuring the dynamic runout of the tool at the command rotational speed after the tool is mounted on the tool spindle, and if the measured value is within the allowable value, the process proceeds to the cutting process. If not, after the tool is unloaded, gripped and clamped, the process moves to the next spindle mounting / unloading process, and the process is repeated until the dynamic deflection reaches the allowable value. This is achieved by the tool changer according to claim 1.

The object of the present invention is (4) a straight shank portion attached to a spindle having a tool spindle of a machine tool, a shank tapered portion connected to the shank portion, and a cutting blade at the tip of the tapered portion. In a tool changing method for exchanging and exchanging a plurality of tools having a section between the tool spindle and a tool magazine,
The plurality of tools have their straight shanks having the same shaft diameter, and the tool is inserted in the vertical direction parallel to the tool spindle with the cutting edge facing downward from the shank base to the cutting edge. A tool magazine provided with a funnel-shaped holding hole for receiving a tool having a shank taper portion that is tapered into a taper shape;
The used tool is picked up from the tool spindle and transferred to an empty holding hole in the tool magazine, and the tool to be used next is picked up from the holding hole in the indexed tool magazine and the tip of the shank is moved to the tool. A gripping claw provided between a tool spindle and a tool magazine for grasping and transferring the shank base of the tool for insertion into the spindle port, wherein the cylindrical shank of the tool is held between the shank and the spindle port. A pair of gripping claws in which a V-shaped groove is provided on the other gripping surface that is associated with the clamp while one gripping surface is flat so as to provide three-point support for projecting the core;
Tools indexed from under the tool magazine for transferring the tool from the tool holding hole of the tool magazine to the tool attaching / detaching means of the spindle and for transferring the tool from the tool attaching / detaching means of the spindle to the tool holding hole of the tool magazine. Stopper bar means that is inserted through the holding hole in parallel with the main shaft, engages with the shank taper portion of the tool, and moves the tool up and down, and the tip of the stopper bar has a tool shank when the tool is mounted on the tool main shaft. The stopper bar means having three stop operation positions including a position of the taper portion, a position immediately below the indexed holding hole of the tool magazine, and a predetermined intermediate position between the two positions,
When transferring the tool removed from the spindle to the tool magazine, the tip of the stopper bar moves upward from the position directly below the holding hole to the position of the tool shank taper when the spindle is mounted on the tool, and the tool attaching / detaching means is unclamped, The tip of the stopper bar is moved downward to the intermediate position, and the straight shank part of the tool is gripped and clamped by the gripping claws. Insert the tool into the holding hole of the magazine with the claw unclamp and return the gripping claw to the original position
Next, when the tool to be used is removed from the magazine, when the tool is installed, the tip of the stopper bar is positioned directly below the holding hole of the tool magazine, and the tool magazine is rotated by a command from the controller to rotate to the next tool. Do the indexing,
Grasping the straight shank of the next tool indexed by lowering and clamping the gripping claw, raising the gripping claw, inserting the shank tip into the spindle port, and raising the stopper bar to the middle position to raise the tool shank The taper part is engaged with the tip of the stopper bar, the gripping claw is unclamped, the tip of the stopper bar is further raised to the position of the shank taper part of the tool when the spindle of the tool is mounted, and the tool is positioned at the attachment / detachment position. This is achieved by an automatic tool changing method for a machine tool characterized in that the tool is mounted and clamped on the main shaft and the tip of the stopper bar is lowered, transferred and retracted immediately below the holding hole of the tool magazine.

Since the tool change method does not use a tool holder,
The tool has become simpler, and it has become easier to apply to the tool change of thin tools used for machining complex shapes such as rib grooves in molding dies.
It is no longer necessary to tighten the tool position accuracy and posture of the tool magazine.
The vibration accuracy of the tool attached to the tool spindle is improved and the vibration is reduced, and it is possible to cope with a high-speed rotation spindle (for example, max120,000 min ⁻¹ ).

  The tool shank is gripped with a gripping claw, and is attached to and detached from the shank attaching / detaching part of the spindle and inserted into and removed from the tool holding hole of the tool magazine. Since the V-groove is provided on the other gripping surface that meets the shank so that the shank is gripped with three-point support, the position and orientation of the gripping shank with respect to the spindle core and the magazine holding hole are kept and maintained, and the tool can be attached and detached. Removal and transfer can be performed reliably and accurately.

  When the tool shank is attached to or detached from the spindle attaching / detaching means, the tool released by the unclamp of the gripping claws is engaged with the tool shank taper and the tip of the stopper that stops rising from below and held. Therefore, it can be applied to the exchange of tools having different tool lengths within the range allowed by the attaching / detaching means.

  As a means for attaching and detaching the tool shank of the tool spindle, a simple structure such as a collet-type spindle end including a shrink-fit collet or a spindle end utilizing elastic deformation can be used.

When the tool is changed, the tool length is first measured to determine whether or not the tool is normal. If it is detected that the tool is not a normal tool,
When there is no substitute tool, an alarm signal or the like is issued, and when it is determined that there is a substitute tool, the attachment tool is returned to the predetermined holding hole of the magazine, and the substitute tool is indexed and shifted to the tool change stage.

  If the tool length is determined to be a normal tool, the tool length correction amount of the control device is rewritten, and then the tool is rotated at a predetermined number of revolutions to proceed to the tool diameter and dynamic runout measurement stage. When it is determined that the runout is within a predetermined allowable value, the tool radius correction amount is rewritten, and then the process of the machining with the replacement mounting tool is performed.

  If it is determined that the measured dynamic deflection of the tool is greater than or equal to a predetermined allowable value, if the determination by the measurement is within a predetermined number of times, the tool is once returned to the magazine and then again. Tool exchange with the same tool to be attached and measurement of tool length and runout are repeated, and if the runout within the allowable value is not obtained even if this reaches the predetermined number of times, it is determined as a defective tool and described above. It can be configured and implemented so as to shift to the process of selecting an alternative tool.

1, 2, and 3 are a plan view, a front view, and a right side view for explaining a schematic configuration of a vertical machining center of an embodiment equipped with the automatic tool changer of the present invention. The table 1 for mounting the head moves in the Y-axis direction along the linear guide 7 on the bed 2, and the spindle head 3A holding the tool spindle 3 is freely movable in the vertical Z-axis by the linear guide 8 on the spindle head saddle 3B. The spindle head saddle 3B is configured to move along the straight guide 9 to the X-axis along the front surface of the column 4 formed in a vertical direction along one edge of the Y-axis. The saddle 3B is configured such that it can be positioned and moved to a tool change position formed extending rightward from the machining area in the X-axis direction. It is preferable to use a linear motor having a predetermined thrust as a driving source for moving the Y-axis, Z-axis, and X-axis.

  The tool magazine of the illustrated embodiment comprises a rotating disk-shaped magazine 5, and the tool magazine 5 is placed on a magazine base 6 comprising a bracket attached to the right side surface of the bed 2. In the figure, a bracket for a base 11C for mounting an actuator 11B for holding and opening a gripping claw 11 for opening and closing a gripping claw 11 for gripping and transferring an exchange tool 10 described later, and a stopper for holding the tool 10 coaxially. Brackets for the base 12C to which the vertical movement actuators 12A and 12B of the bar 12 are attached are provided on the side wall of the bed or the vertical portion of the magazine bracket 6, respectively. The bracket 11C for mounting the actuators 11A and 11B for driving the gripping claws 11 and the bracket 12C for mounting the actuators 12A and 12B for driving the stopper bar are the same as the configuration for mounting the bracket 6 for the magazine base.

  FIG. 4 is a plan view of the tool change part viewed from the front end side of the spindle 3 with the corresponding part of the magazine 5 cut away, FIG. 5 is an enlarged front view of the tool change part, and FIG. 6 shows the tool change part from the right side. 7 is a plan view showing the opening / closing gripping claw 11 portion together with the opening / closing actuator 11A portion, and FIG. 8 is a tool spindle 3 in the tool holding hole 5A portion of the tool magazine 5 and the tool gripping. It is explanatory drawing for demonstrating the engagement between the nail | claw 11 and the tool holding | maintenance stopper bar | burr 12, and a separation relationship.

  In the figure, the disk-shaped tool magazine 5 has tool holding holes 5A formed at positions at predetermined angular intervals on a predetermined circumference, and the tool holding holes 5A have, for example, a diameter φ3.0 mm, Alternatively, a cylindrical straight shank portion 10A having the same diameter of φ4.0 mm, a tapered shank taper portion 10B following the tip end side, and a thin tool 10 having a blade portion 10C at the tip end are arranged in a vertical direction parallel to the main shaft 3. The protrusion length of the shank portion of the tool 10 inserted and held in each hole 5A to the surface of the magazine 5 is preferably formed in a funnel-like hole that is held by inserting the blade edge downward in the direction. Are adjusted and formed with respect to the tapered size and shape of the shank taper portion 10B of each tool 10 so that they are the same.

  With such a configuration, the disc-shaped magazine 5 in which the predetermined tool 10 is inserted into the predetermined holding hole 5A is attached to the rotary indexing means 5B that is positioned and installed on the magazine base 6 by the fine positioning adjuster 6A. Then, the motor 5C is driven in response to a machining start or tool attachment command from an NC controller (not shown) or a next tool attachment tool exchange command for machining at the next machining stage, and the rotation indexing means 5B is rotated. The command tool 10 and its holding hole 5A are indexed to the replacement position.

  Reference numeral 11 denotes a gripping claw of the tool shank 10A, one or both of which moves in parallel in the opposite direction and clamps together and is released by unclamping. When the tool shank 10A is tightly gripped by the gripping claw 11, the gripping shank The gripping surface of one of the claws 11a so that the gripping of the straight shank portion 10A by the gripping claws 11 is supported at three points so that the shaft core of 10A always has the same or constant positional relationship with the axis of the main shaft 3. Is a flat surface, but the V-shaped groove 11-0 is provided on the gripping surface of the other claw 11b to be clamped and the gripping claw 11 in the state of gripping the shank portion 10A. Up and down transfer by the actuator 11B, extraction of the magazine 5 from the tool holding hole 5A and insertion of the shank 10A tip into the spindle port, and extraction from the spindle port and insertion into the holding hole 5A. Smooth, and is to be ensured.

  In order to achieve the above object, the gripping claw 11 formed integrally with the claw opening / closing actuator 11A is held so as to be movable up and down in parallel with the Z-axis with respect to the mounting bracket 11C, and is provided on the bracket 11C. The claw 11 is moved by the vertical movement actuator 11B with the protruding end position of the spindle 3 at the time of tool replacement as the upper limit and the position immediately above the tool holding hole 5A of the tool magazine 5 as the lower limit.

  12 denotes a tool transfer from the tool holding hole 5A of the tool magazine 5 to a tool attaching / detaching means such as various collet chucks in which the main shaft 3 is built in the tip, and a tool holding hole 5A of the tool magazine 5 from the tool attaching / detaching means of the main shaft 3. For the transfer of the tool 10 to the tool, the tool 10 is inserted into the tool holding hole 5A indexed from the bottom of the tool magazine 5 in parallel with the main shaft 3 and engaged with the shank taper portion 10B of the tool to move the tool 10 up and down. Stopper bar means, the tip of the stopper bar means 12 is located at the position (upper position) of the shank taper portion 10B of the tool 10 when the tool is mounted by tool change, and the indexed tool holding hole 5A of the tool magazine 5 There are three stop operation positions: a position directly below (lower position) and a predetermined intermediate position between the two positions.

  The stopper bar 12 has a diameter smaller than that of the tool shank 10 </ b> A and a diameter that is not gripped by the gripping claws 11, and at least a tip portion is hollow, and the shank taper portion 10 </ b> B of the downward tool 10 is fitted. A configuration having a fitting hole 12a is preferable. The stopper bar means 12 is held on the bracket 12C via two lifting actuators 12A and 12B so that the tip of the stopper bar means 12 can be moved up and down in parallel with the Z axis with the three positions described above as stop positions. That is, the holder for holding the stopper bar means 12 is attached to the vertically moving actuator 12A having a small stroke (for example, about 10 mm) between the upper position and the intermediate position, and the actuator 12A is attached to the bracket 12C with a large stroke ( For example, it is held by the vertically moving actuator 12B of about 50 mm) and moves up and down.

  FIG. 9 and FIG. 10 are explanatory views of one embodiment of the above-described main spindle 3 protruding end, the entire tool 10, the shape of the gripping claws 11, and the stopper bar means 12, and the blade portion at the tip of the tool 10. 10C is loosely fitted in the fitting hole 12a at the tip of the stop bar 12, and the tapered surface of the taper shank portion 10B of the tool 10 is fitted and engaged with the inlet taper mouth portion 12b of the fitting hole 12a. It is configured. The relationship between the taper shank portion 10B and the taper surface thereof, the tool holding hole 5A of the magazine 5, the taper 5a, and the like has already been described. Further, as a tool 10 installed in the tool magazine 5, for example, tools having different taper angles and shank lengths of the taper shank portion 10 can be used.

The operation of the above tool changer of the present invention will be described based on the sequence table shown in FIG.
(1) A “next tool command (T **)” code is read from a program read into a control device of a machine tool such as a machining center,
(2) By reading the code (M06), the operation stage for preparing for tool change start is entered,
(3) Movement command to Z-axis ascent limit,
(4) Coolant stop command (M09),
(5) Spindle stop command (M05),
(6) X-axis machining area interlock OFF,
(7) Right to the X-axis cleaning position,
(8) Lower to the Z-axis cleaning position,
(9) When the tool cleaning is turned on, the tool cleaning sequence is entered.
(10) End with tool cleaning OFF,
(11) Move the Z axis to the upper limit.

(12) The cover of the tool changer is opened and the operation for returning the tool changing spindle mounting tool 10 to the tool magazine 5 is entered.
In addition, the position of the spindle (Z axis) after this stage (ascending limit or tool change position?)
-Detaching / removal state of tool spindle (CL or UCL?)
・ Location of old new tools (spindle, intermediate position, magazine?)
-The position of the gripping claw 11 (tool change position or magazine upper position?)
-The gripping claw 11 is gripped and opened (CL or UCL?)
The position of the tip of the stopper bar 12 (under the magazine, at the tool change position, or so-called intermediate position)
The extended (up) and retracted (down) states of the short stroke actuator. The extended (up) and retracted (down) states of the long stroke actuator are as shown on the right side of the table of FIG.
Further, the positions of the spindle 3, the tool 10, the gripping claws 11, and the stopper bar 12 at each sequence No (**) are as shown in FIGS.

(13) X axis rightward movement for positioning the spindle at the tool change position;
(14) In response to the magazine command, the tool 10 mounted on the spindle 3 indexes the empty holding hole 5A to the tool change position,
(15) Next, a UCL command for the gripping claw (Sequence No. (31) should have been maintained in the previous tool change, but check to prevent interference).

(16) Actuate the stopper bar 12 with short and long stroke actuators 12A and 12B (in the embodiment, each is an air cylinder) to move the tip from the index magazine holding hole 5A to the uppermost position (the tool 10 is connected to the spindle 3). Set the attachment / detachment means to the position when it is clamped.
(17) The spindle 3 is lowered to the position at which the tool is changed. At this time, the shank taper portion of the tool 10 is fitted into the fitting hole 12a at the tip of the stopper bar 12, and is engaged with each other.
(18) After the spindle axis air blow ON (when the shank is hollow),
(19) When the tool attaching / detaching means in the spindle of the tool 10 is UCL, the stopper bar 12 is in a state of receiving and supporting the tool 10,
(20) When the actuator 12A with a short stroke is lowered and the tip of the stopper bar 12 is lowered to the intermediate position, the tool 10 is surely guided and lowered.

(21) Here, when the actuator 11A of the gripping claw 11 is driven, the shank straight portion 10A of the tool 10 is brought into contact with the two surfaces of the V-groove 11-0 and the plane between the claws 11a and 11b. In a state that fits the 3 spindles of the main shaft without causing position change or flattening in 10
(22) After lowering the stopper bar 12 to the lower limit position below the magazine 5,
(23) Since the tool 10 is lowered by the gripping claws 11, the tool 10 is removed from the main shaft attaching / detaching means with little interference, and further lowered,
(24) The tool 10 held by the UCL of the gripping claws 11 can be released and the tool 10 can be accurately returned to the tool holding hole 5 </ b> A of the magazine 5. And where
(25) Shifting to the next new tool indexing stage without causing the gripping claws 11 and the tool 10 of the magazine 5 to interfere by raising the actuator 11B to return the gripping claws 11 to the tool change position. Become.

Since the sequence steps of attaching and detaching the tool 10 are substantially opposite to each other, the mounting step will be briefly described below.
(26) In response to the next tool command T **, the magazine 5 is rotated to index the next tool 10, and (27) the shank 10A of the indexing tool 10 on the magazine 5 is placed between the claws 11a and 11b. Descend.
(28) CL of the gripping claws 11 and grasping the shank 10A while being fitted between the V groove 11-0 and the plane,
(29) When the gripping claws 11 are raised, the shank 10A is positioned at an intermediate position where it is inserted halfway from the rear end into the spindle port.
(30) Therefore, by raising the stopper bar 12 to a so-called intermediate position by driving the long stroke actuator 12B, the lower edge of the tool 10 gripped by the gripping claws 11 and the tip of the stopper bar 12 are fitted. Since it engages and supports
(31) The gripping claw 11 is UCL,
(32) Insert the shank of the tool 10 released by the stopper bar 12 to the upper tool change position by driving the actuator 11A of the short troke,
(33) Mount by setting the tool attachment / detachment means in the spindle to CL,
(34) When the stopper bar 12 is lowered to the lower limit position below the magazine 5,

(35) Spindle axis air blow OFF,
(36) Move the spindle to the Z-axis ascent limit,
(37) Close the cover of the tool changer,
(38) Move and position the spindle to the machining area on the X axis,
(39) Turn on the X-axis machining area interlock,
(40) The programmed tool change sequence is terminated.

  FIG. 20 shows a case where a new tool or a next tool is attached to the spindle 3 by the automatic tool changing means as described above, and the attached tool 10 is a normal tool (predetermined length) before proceeding to the processing stage of the workpiece. If the tool is determined to be a normal tool, whether or not the tool is correctly mounted and clamped on the spindle (tool diameter, rotational runout). Is a predetermined value).

  When starting the operation of the machine tool and attaching a programmed tool to the control device, or when the next program command is issued for any reason as the machining program proceeds, automatic tool change as described above, The tool is attached, and after the attachment, the process proceeds to the tool length measurement stage, and measurement is performed by a tool length measurement sequence as shown in FIG.

  If the tool length is determined to be “normal tool” as a result of the tool length measurement, the tool length correction amount is rewritten, and the process proceeds to the next tool diameter measurement and tool dynamic runout measurement stage. Measurement is performed by a tool diameter / runout measurement sequence as shown in FIG.

  When the tool is rotated at a predetermined number of revolutions and the measured diameter and dynamic runout are within a predetermined tolerance, the correction amount of the tool diameter is rewritten, and the workpiece is processed by the mounting tool. If the machining is completed and there is a next tool command, the process returns to the above-described tool replacement process. If not, the machining program is terminated.

  When it is determined that the tool length measurement result is not a normal tool, it is determined whether or not there is a substitute tool in the tool magazine. The tool is returned to the corresponding holding hole 5A, the substitute tool is determined, and the process proceeds to the above-described tool replacement process. If there is no substitute tool, this is notified to the operator by, for example, an alarm display.

  If it is detected that the measured value exceeds the allowable value as a result of the above-mentioned tool diameter / run-out measurement, what is the mounting position of the tool on the spindle 3 or the shank gripping state of the equipment collet chuck, etc. In such a case, there is a possibility that there is an abnormal problem, and in such a case, the tool being mounted is removed and once returned to the corresponding tool holding hole 5A of the tool magazine 5, and then the tool is replaced using the same tool. The measurement of the tool length and the measurement of the tool diameter and runout of the reattached tool were sequentially performed, and the above-mentioned runout was determined to be a predetermined number of times or more, although it was a normal tool. At this time, the process proceeds to the step of determining the presence / absence of the substitute tool. Of course, if the deflection is within the allowable value before the above determination is repeated a set number of times, it is natural to move to the stage of machining the workpiece by the mounting tool.

  The present invention relates to an automatic tool changer for a machine tool such as a machining center that performs processing such as cutting and grinding while automatically changing a tool, in particular, a thin shank taper portion with a tool shank diameter of about φ4.0 mm or less. It can be used as a tool changer useful for realizing high-speed and high-precision machining by using a tool having no holder.

The top view for demonstrating schematic structure of the machine tool of one Example carrying the automatic tool changer of this invention. Similarly front view. Similarly right side view. The enlarged plan view of the principal part which notched a part. The enlarged front view of the principal part. The enlarged right view of the principal part. The top view of principal part components. Front explanatory drawing in order to demonstrate the function and operation | movement of a principal part. FIG. 9 is an enlarged explanatory diagram of an example of the shape and dimensions of the article shown in FIG. FIG. 10 is a further enlarged view of the portion of FIG. 9. The operation | movement sequence table | surface of this invention apparatus. The front view which shows the mutual positional relationship of the action | operation article shown corresponding to the number of the sequence table. The front view which similarly shows the positional relationship at the time of another sequence number. The front view which similarly shows the positional relationship at the time of another sequence number. The front view which similarly shows the positional relationship at the time of another sequence number. The front view which similarly shows the positional relationship at the time of another sequence number. The front view which similarly shows the positional relationship at the time of another sequence number. The front view which similarly shows the positional relationship at the time of another sequence number. The front view which similarly shows the positional relationship at the time of another sequence number. The flowchart figure of one Example of the method of measuring and inspecting a tool and a tool attachment condition after the tool replacement | exchange of this invention. The sequence table of one Example of a measurement inspection similarly. The sequence table of the other Example of measurement inspection similarly.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Table 2 Bed 3 Spindle 3A Spindle head 3B Spindle head saddle 4 Column 5 Tool magazine 5A Tool holding hole 5B Turning device 5C Drive motor 6 Magazine base bracket 7, 8, 9 Linear guide device 10 Spindle 10A Shank 10B Shank taper part 11 Holding claw 11A Open / close actuator 11B Lifting actuator 11C Bracket 11a, 11b Claw 11-0 V-shaped groove 12 Stopper bar 12A Short stroke actuator 12B Long stroke actuator 12C Bracket 12a Tip fitting hole

Claims (4)

A plurality of tools having a straight shank portion mounted on a spindle having a tool spindle having a tool attaching / detaching means of a machine tool, a shank tapered portion connected to the shank portion, and a cutting blade portion at the tip of the tapered portion. In a tool changer for exchanging and exchanging between the tool spindle and the tool magazine,
The plurality of tools have their straight shanks having the same shaft diameter, and the tool is inserted in the vertical direction parallel to the tool spindle with the cutting edge facing downward from the shank base to the cutting edge. A tool magazine provided with a funnel-shaped holding hole for receiving a tool having a shank taper portion that is tapered into a taper shape;
The used tool is picked up from the tool spindle and transferred to an empty holding hole in the tool magazine, and the tool to be used next is picked up from the holding hole in the indexed tool magazine and the tip of the shank is moved to the tool. A gripping claw provided between a tool spindle and a tool magazine for grasping and transferring the shank base of the tool for insertion into the spindle port, wherein the cylindrical shank of the tool is held between the shank and the spindle port. A pair of gripping claws in which a V-shaped groove is provided on the other gripping surface that is associated with the clamp while one gripping surface is flat so as to provide three-point support for projecting the core;
Tools indexed from under the tool magazine for transferring the tool from the tool holding hole of the tool magazine to the tool attaching / detaching means of the spindle and for transferring the tool from the tool attaching / detaching means of the spindle to the tool holding hole of the tool magazine. Stopper bar means that is inserted into the holding hole in parallel with the main shaft, engages with the shank taper portion of the tool and moves the tool up and down, and the tip of the stopper bar has a tip of the tool when the tool is mounted on the tool main shaft. The stopper bar means has three stop operation positions: a position of the shank taper portion, a position immediately below the indexed holding hole of the tool magazine, and a predetermined intermediate position between the two positions. A machine tool automatic tool changer characterized by the above. The tool attaching / detaching means for the tool spindle is any one of a collet tightening / loosening means for the tool shank, a shrink-fit collet, or an elastic deformation applied type spindle hole tightening / loosening means. Tool changer. After the tool is mounted on the tool spindle, the dynamic runout of the tool is measured at the command rotational speed, and if the measured value is within the allowable value, the process proceeds to the cutting process. The tool according to claim 1, wherein after the grip clamp, the tool shifts to a next spindle attachment / detachment step like a grip unclamp, and has a step of repeating a set number of times until the dynamic deflection reaches an allowable value. Exchange equipment. A plurality of tools having a straight shank portion mounted on a spindle having a tool spindle having a tool attaching / detaching means of a machine tool, a shank tapered portion connected to the shank portion, and a cutting blade portion at the tip of the tapered portion. In the tool exchange method for exchanging and exchanging between the tool spindle and the tool magazine,
The plurality of tools have their straight shanks having the same shaft diameter, and the tool is inserted in the vertical direction parallel to the tool spindle with the cutting edge facing downward from the shank base to the cutting edge. A tool magazine provided with a funnel-shaped holding hole for receiving a tool having a shank taper portion that is tapered into a taper shape;
The used tool is picked up from the tool spindle and transferred to an empty holding hole in the tool magazine, and the tool to be used next is picked up from the holding hole in the indexed tool magazine and the tip of the shank is moved to the tool. A gripping claw provided between a tool spindle and a tool magazine for grasping and transferring the shank base of the tool for insertion into the spindle port, wherein the cylindrical shank of the tool is held between the shank and the spindle port. A pair of gripping claws in which a V-shaped groove is provided on the other gripping surface that is associated with the clamp while one gripping surface is flat so as to provide three-point support for projecting the core;
Tools indexed from under the tool magazine for transferring the tool from the tool holding hole of the tool magazine to the tool attaching / detaching means of the spindle and for transferring the tool from the tool attaching / detaching means of the spindle to the tool holding hole of the tool magazine. Stopper bar means that is inserted through the holding hole in parallel with the main shaft, engages with the shank taper portion of the tool, and moves the tool up and down, and the tip of the stopper bar has a tool shank when the tool is mounted on the tool main shaft. The stopper bar means having three stop operation positions including a position of the taper portion, a position immediately below the indexed holding hole of the tool magazine, and a predetermined intermediate position between the two positions,
When the tool taken out from the spindle is transferred to the tool magazine, the tip of the stopper bar moves up from the position directly below the holding hole to the position of the tool shank taper when the spindle of the tool is mounted, and the tool attaching / detaching means is unclamped, The tip of the stopper bar is moved downward to the intermediate position, and the straight shank part of the tool is gripped and clamped by the gripping claws. Insert the tool into the holding hole of the magazine with the claw unclamp and return the gripping claw to the original position
Next, when the tool to be used is removed from the magazine, when the tool is installed, the tip of the stopper bar is positioned directly below the holding hole of the tool magazine, and the tool magazine is rotated by a command from the controller to rotate to the next tool. Do the indexing,
Grasping the straight shank of the next tool indexed by lowering and clamping the gripping claw, raising the gripping claw, inserting the tip of the shank into the spindle port, and raising the stopper bar to the intermediate position, The taper part is engaged with the tip of the stopper bar, the gripping claw is unclamped, the tip of the stopper bar is further raised to the position of the tool shank taper part when the spindle of the tool is mounted, and the tool is positioned at the attachment / detachment position. An automatic tool change method for a machine tool, characterized in that a tool is mounted and clamped on a main shaft, and a stopper bar tip is moved down and retreated directly under a holding hole of a tool magazine.