JP4425441B2 - Machining center tool correction or remanufacturing method, and machining center - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a machining center for a numerically controlled machine tool, and in particular, a machining method for correcting or remolding a tool while the tool is attached to the tip of a spindle, and a machining center provided with the correction or remolding accessory device. About.
[0002]
[Prior art]
A tool holder with the target tool attached is selected, removed from the tool magazine by the tool changer, mounted on the spindle, used for predetermined machining, and used while being exchanged with other tools as needed. When a predetermined cumulative use time is reached or the wear limit is detected by some wear detection means such as light, the tool is returned to the tool magazine, and other newly prepared or polished, etc. It will be replaced with a regenerated tool.
[0003]
Recently, cutting-edge machining centers have been increasingly applied to mold machining, and demands for precision machining have increased. And in the case of this mold processing, when it is a creation molding process such as a cavity, there is not a small amount of long-time processing with one tool for one workpiece, and the tool often reaches the limit of use during processing However, in such a case, there is a problem that the machining accuracy is often greatly lowered when the tool magazine is replaced with another identical new or regenerated tool prepared in advance. This is due to the non-uniformity of the dimensional accuracy of each other new tool or refurbished tool, the tool holder and its mounting accuracy, and particularly the mounting accuracy of the tool holder to the spindle.
[0004]
In order to solve this problem, firstly, when a new tool is attached to the main spindle by changing the tool, the measurement tool checks the shape, dimensions, rotation balance, etc. Although it is conceivable to perform processing for the correction, it has been practically rarely tried so far because such a response is difficult.
[0005]
In addition, in order to solve the above-mentioned another problem, there is a machining center that can re-grind the tool without removing the worn tool from the main spindle and continuously perform the same type of machining without interrupting the machining for a long time. It has been proposed (see JP-A-6-170,704).
And this prior art is attached to at least one of a plurality of work tables so that the grindstone is rotationally driven by the driving means, and when the wear of the tool attached to the spindle advances by a predetermined amount or more, During this period, the grindstone, which is equipped with a grindstone position control means for turning the grindstone in the horizontal direction, moving up and down, and rotating in the vertical direction, is moved together with the work table so that the tool is ground with the tool attached to the spindle. I have to.
[0006]
[Problems to be solved by the invention]
According to this prior art method, there is no need to attach or remove the tool to or from the main spindle of the machining center or the grinding machine, and the tool remains attached to the main spindle. Although the problem of non-uniform turning radius can be avoided, end mills with tapered fine shapes that have become widely used recently, such as carbide square type, carbide pole type, carbide taper type end mills, etc., have fine shape accuracy. There was a limit to the efficient remolding finish. That is, in the correction or remanufacturing by mechanical cutting or grinding, it is difficult to apply it to an end mill tool of a hard-cutting cemented carbide because of cutting or grinding resistance.
[0007]
On the other hand, it is known to use electric discharge machining in which cutting or grinding pressure does not act other than the discharge pressure of fine electric discharge repeated at a high frequency for machining for tool forming or regenerative dressing (for example, JP-A 63-63). No. 283,861, JP-A-9-225759, JP-A-8-243,927, or JP-A-10-512, etc.) and finishing by correcting or regenerating a tool that meets the object of the present invention. A machining center provided with the attached device or a cutting method using the machining center has not been proposed yet.
[0008]
That is, according to the present invention, when the tool is attached to the main shaft or when the wear of the attached tool reaches a predetermined amount, the tool is attached to the main shaft by electric discharge machining, which also uses a straight wire electrode that travels in the liquid. It is a dress forming and finishing process precisely by wire electric discharge machining, and is particularly effective when applied to an end mill tool made of a cemented carbide with a small diameter.
[0009]
[Means for Solving the Problems]
The object of the present invention described above is (1) a machining center in which a workpiece of the workpiece setting means is disposed on a machining table directly below a spindle to which a tool is attached, and the workpiece is cut.
A wire electric discharge machining tank having a machining section travel path forming means in which a wire electrode is stretched in a predetermined tilt axis direction and a wire electrode supply / discharge means for supplying and collecting the wire electrode to the travel path forming means are integrated. Prepared as
When the tool is attached to the spindle, or when wear of the attached tool advances by a predetermined amount or more, the wire electric discharge machining tank is moved and arranged directly below the spindle, instead of the workpiece installation means, and the travel path forming means The machining section wire electrode capable of controlling the posture at a predetermined inclination angle in a direction perpendicular to the horizontal and vertical axes and the tool of the spindle are opposed to each other in the machining liquid immersion state. ,
An output terminal of a wire electric discharge machining power source is connected to the wire electrode of the travel path forming means and the tool, and a relative movement is given by numerical control between the two, thereby performing regenerative molding by wire electric discharge machining and finishing of the molding surface. This is achieved by using a machining center tool correction or remanufacturing method characterized by sequentially performing the steps with the tool attached to the spindle.
[0010]
The object of the present invention described above is achieved by (2) the machining correction / regeneration method for a machining center according to (1), wherein the tool is an end mill tool made of cemented carbide.
[0011]
Further, the object of the present invention is as follows: (3) A plurality of work tables are exchanged and installed on a machining table support just below the main shaft to which the tool on the front surface of the machine body is attached, and the machining head with the main shaft attached to each table. In a machining center for cutting a workpiece by controlling and moving in the direction of three axes at right angles to each other,
The main spindle head has a built-in turning and indexing means for turning and controlling the main spindle.
One of the work tables includes a wire electric discharge machining tank having a wire electrode traveling path forming means for stretching the wire electrode in a predetermined tilt axis direction, and a wire electrode supply for supplying and collecting the traveling wire electrode. The travel path forming means is provided with a pair of positioning guide devices that can be opposed to each other at an interval in the direction of the inclined axis that forms the machining portion wire electrode. Is provided with an inclination angle position control means so that the machining part wire electrode can take a predetermined inclination angle with respect to the horizontal and vertical axes with respect to the tool attached to the lower end of the main shaft,
Furthermore, when the tool is attached to the spindle, or when the wear of the attached tool reaches a predetermined amount or more, replacement arrangement means for moving and arranging the wire electric discharge machining tank directly below the spindle, a processing portion wire electrode, and a tool, Power supply connecting means for connecting a wire electric discharge machining power source between the two facing each other in the state of machining liquid immersion, electric discharge machining between the wire electrode and the tool, the relative movement means, swiveling, indexing means and inclination angle position control means This is achieved by providing a machining center provided with a control device that performs the above-mentioned control.
[0012]
The above-mentioned object of the present invention is as follows. (4) The machining portion wire electrode tilt angle position control means includes at least a vertical axis for one or both of the holding means of the pair of guide devices of the travel path forming means. This is achieved by using the machining center as described in (3) above in which a stage capable of adjusting and controlling the position beyond the axis is provided.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a front view for explaining a schematic configuration of a machine main part of a machining center of the present invention, and FIG. 2 is a plan view of a wire electric discharge machining tank part for tool correction or remanufacturing.
[0014]
In the figure, 1 is a bed of the processing machine main body, 2 is a base on the bed, 3 is a column 4 provided so as to be able to control-feed relative to the bed 1 or base 2 in two horizontal and perpendicular directions. Further, a machining head mounted via a feed drive mechanism (not shown) that feeds and positions the workpiece in the vertical (Z-axis) direction, 5 is a spindle held by the machining head 3, 6 is a rotation drive motor for the spindle 5, Reference numeral 7 denotes swivel indexing means for controlled rotation and indexing around the axis of the main shaft 5. A tool holder 9 having a tool 8 such as an end mill or a drill is attached to the lower end of the main shaft 5 by a tool holding device 10. Removably attached. The feed drive mechanism in which the machining head 3 performs machining feed and positioning in the vertical direction with respect to the column 4 may have a configuration provided in an attachment holding portion between the machining head 3 and the main shaft 5.
[0015]
At a position directly below the processing head 3 on the base 2, a work table 12A on which a workpiece 11A is positioned and attached is an auxiliary such as an auto pallet changer on which another workpiece 11B is positioned and attached. A processing table receiver 13 is provided which is installed in exchange for the work table 12B on the table receiver 14B. In the illustrated case, auxiliary table receivers 14B, 14C, and 14D are arranged on the base 2 in a horizontal uniaxial direction, such as an auto pallet changer. ... one of the work tables 12B, 12C, 12D, ... disposed on a plurality of auxiliary table receivers 14B, 14C, 14D, ... arranged in a semicircular shape about the machining head 3 as a center. Even if the work table 12A on the processing table receiver 13 is transferred to the bright auxiliary table receiver on the contrary, the work table 12A is transferred onto the processing table receiver 13 disposed on the central front surface of the machine body. good.
[0016]
As shown in FIG. 1, the work table 12D on the one auxiliary table receiver 14D has a wire electric discharge machining tank 15 for performing wire electric discharge machining in a machining liquid immersion state. A wire electrode supply / discharge device 16 for supplying and recovering the wire electrode 18 to the electrode travel path forming means 17 is integrally connected to the work tables 12A, 12B,... On which the workpieces 11A, 11B,. Instead, the work table 12D is moved onto the machining table receiver 13, and the tool 8 such as an end mill attached to the lower end of the spindle 5 is moved into the wire electric discharge machining tank 15 by the downward feed positioning of the spindle 5 or the machining head 3. This is a state in which wire electric discharge machining can be executed in opposition to a later-described machining portion wire electrode 18A formed by immersion in the filling machining liquid by the travel path forming means 17. That.
[0017]
The wire electrode travel path forming means 17 in the wire electric discharge machining tank 15 has a pair of positioning guide devices 19 and 20 for forming the machining portion wire electrode 18A in a desired direction parallel to one of the two horizontal axes. Provided via stages 21 and 22 with respective height and horizontal position adjusting devices at intervals, and further on the supply unit side of the supply / discharge device 16 with respect to the former guide device 19 of the pair of positioning guide devices 19 and 20 The supply wire electrode guide pulley 23 and the return guide pulleys 24A and 24B which are arranged downstream of the latter guide device 20 and guide the wire electrodes to the supply / discharge device 16 side, and the returned wire electrodes 18 are collected by the supply / discharge device 16. It is comprised by the guide pulley 25 to the part side.
[0018]
The height of the guide devices 19 and / or 20 and the position adjustment means 21V in the horizontal biaxial direction are shared by at least one or both of the stages 21 and 22 for mounting and holding the positioning guide devices 19 and 20. And 21HX, 21HY and driving means 21VM with automatic measurement detecting means, and 21HXM, 21HYM are provided, and the processing portion wire electrode 18A between the guide devices 19 and 20 is arranged in a predetermined direction perpendicular to the horizontal or vertical axis. The wire electric discharge machining in a state where the inclined posture is adjusted and set to an arbitrary angle, or the wire electric discharge machining can be advanced while continuously changing and controlling according to a program or the like.
[0019]
Then, the machining portion wire electrode 18A between the pair of guide devices 19 and 20 is horizontal from the relationship of the mode of correction or reworking with respect to the workpiece tool 8 that remains attached to the spindle 5, as will be described later. First, it is necessary to have a configuration in which the tilt angle can be changed, adjusted, and set to a state that is almost vertical. For this reason, in the present invention, for example, the other guide device 20 side can be positioned higher than the lower position on the guide device 19 side, and the two can be installed close to each other up and down on one vertical axis. In addition, a height position and a moving mechanism 22A for proximity movement are provided for the stage 22, although details are omitted in the drawing.
The pair of guide devices 19 and 20 are preferably opposed to each other on the axis of the processing portion wire electrode 18A for feeding movement and positioning accuracy of the wire electrode 18 or for jetting the processing liquid. Although not shown in the drawing, the guide devices 19 and 20 are held via an appropriate swing adjustment mechanism or the like.
[0020]
Further, the machining portion wire electrode 18A between the pair of guide devices 19 and 20 is filled with the machining fluid by the machining fluid supply / discharge means 26 of the machining tank 15 in the machining liquid at a predetermined depth below the machining liquid surface. For example, as disclosed in Japanese Patent Application Laid-Open No. 10-512, for example, as an electric discharge machining in a powder-mixed machining liquid in which a conductive powder is mixed in a machining liquid, It can be executed by applying electric discharge machining of surface treatment for forming a modified layer on the cutting edge of the rotary cutting tool.
[0021]
In the case of FIG. 1, the wire electrode 18 supply / discharge device 16 is shown only on the wire electrode supply part side, 16A is a wire electrode storage bobbin, 16B is a tension forming brake pulley, and 16C is a bobbin 16A lead wire. A feed control pulley that feeds the electrode to the brake pulley 16B without fluctuation in tension, 16D is the servo pulley, 16E is a guide pulley to the processing tank 15, and a collection unit (not shown) is a wire from the discharge guide pulley 25 of the processing tank 15. A take-up roller for picking up the electrode 18 at a constant speed under a set condition by properly guiding it, a take-up bobbin for taking up the wire electrode taken up, a collection bucket for collecting without taking up, or cutting into a predetermined length And a bucket for recovering by cutting, or a cutting device for cutting and recovering to a predetermined length and its recovery bucket are provided. Than is.
[0022]
Note that the machining pulse power supply for wire electric discharge machining and machining feed and other control devices such as CNC are not shown, and a guide device 19 in which positioning guides for the machining portion wire electrode 18A are provided. , 20 show only lead wires 19A and 20A for connecting a power supply line to a not-shown power supply. Although not shown in the drawing, the machining center shown here is provided with various types of measurements for detecting the shape, dimensions, rotational balance, wear amount or chipping of the tool 8, and a wear detector. When the tool detects that the tool 8 is displaced or worn by a predetermined value or more, a predetermined signal is sent to the control means for controlling the machining center, and the worn tool 8 is attached to the lower end of the spindle 5 as will be described later. In this state, the wire electrical discharge machining with the wire electrode that can be controlled to change the tilting posture as it is, the correction or regeneration molding process and the finishing process that switches the wire electrical discharge machining conditions for the molding surface are sequentially performed. Done.
[0023]
As the tool 8 to be used for correction by wire electric discharge machining or remanufacturing molding and finishing of the molding surface, various rotary end mills and drills are preferable, but mechanically difficult to machine due to high hardness. In addition, the WC-Co alloy system that is difficult to mechanically cut or grind due to the holding state or the like from the place where the work is still attached to the lower end of the main spindle 5, and is brittle and has low toughness due to the sintered body. Cemented carbide tools, especially end-mills such as carbide square type, carbide ball type, carbide taper type, carbide taper ball type, carbide radius type, etc. Many advantages are effective when applied to tools.
[0024]
Next, a correction or regeneration molding process using a tool correction or regeneration processing apparatus in the machining center having the above-described configuration, and a finishing method of the molding surface will be described. The workpiece 11A attached to the work table 12A on the machining table receiver 13 is subjected to predetermined machining while changing one tool 8 or the tool 8 as necessary, but a new tool 8 is exchanged for the spindle. When the tool 8 is attached, a predetermined signal is sent from the detector (not shown) to the control means for controlling the machining center when the tool 8 is worn more than a predetermined value in the middle of machining or a relatively slight chipping or the like has occurred. . Then, the following correction or regeneration molding by wire electric discharge machining and finishing of the molding surface are automatically performed on the tool 8 attached to the main shaft 5.
[0025]
An automatic pallet changer (not shown) or the like is operated, and the work table 12A to which the workpiece 11A being processed is attached is transferred to an empty auxiliary table receiver 14A (not shown). Next, a wire electric discharge machining tank 15 having wire electrode travel path forming means for wire electric discharge machining integrated with the wire electrode supply / discharge means 16 is attached on the empty processing table receiver 13. The work table 12D is transferred and installed. In the illustration in FIG. 1, the work table 12D is described as being longer than the other work tables 12A, 12B,..., Because this describes in detail the installations on the work table 12D. In actuality, the work table 12D has the same size as the work tables 12A and 12B, or a size and shape that can be installed on the processing table receiver 13 even if they are not the same size.
[0026]
The length of the machining portion wire electrode 18A between the pair of guide devices 19 and 20, the height position with respect to the horizontal, and the inclination angle, the installation position of the wear tool 8 by machining of the main shaft 5 or the machining head 3, and the axis of the tool 8 The relative position on the horizontal right-angled biaxial plane with respect to the machining portion wire electrode 18A is preliminarily input to one or both of the wire electrical discharge machining control device and the machining center control device, and is linked from the control device or the like. The wire EDM tank 15 is filled with a machining liquid to a predetermined liquid level by a signal generated in the same manner, and the wire electrode 18 is tensioned between the take-up device (not shown) and the brake pulley 16B, so that the machining portion wire electrode 18A A guide device formed between the wire electrode 18 and the tool 8 may be used as a positioning guide means and a machining liquid nozzle. 9 and 20, and the latter is connected to a wire electrical discharge machining source via a spindle power supply means 5 </ b> A via the spindle 5, and correction of the tool 8 by wire electrical discharge machining or reshaping is started. It will be.
[0027]
FIGS. 3 to 6 show a specific example of an end mill tool to be corrected or reshaped by a side view and a front view of the tip of the cutting edge, respectively. FIG. 3 shows a carbide square type blade number 1 and a twist angle of 12 °. 4 is the standard type with 2 blades of carbide carbide type with 2 blades and helix angle of 30 °. Figure 5 shows 2 blades of carbide taper type and helix angle of 40 °. FIG. 6 shows a carbide ball type long neck ball end middle with 2 blades and a twist angle of 30 °.
[0028]
According to the wire electrode travel path forming means 17 of the wire electric discharge machining tank 15 of the present invention, the processed part wire electrode 18A between the pair of positioning guide devices 19 and 20 is almost vertically moved from the stretched travel state on the horizontal axis. From where the control of the inclination angle to a close state can be performed, horizontal cutting of the tip of the tool 8, forming of the rake face and torsion groove surface of the cylindrical or tapered cylindrical side surface, and the outer peripheral cutting blade flank surface, and further rotation In the state in which the tool 8 axis and the machining part wire electrode 18A axis cross each other at a predetermined angle, the relative horizontal biaxial feed between them and the control swiveling around the axis of the tool 8 are performed. According to a pre-preparation program that is combined with feed in the vertical axis direction, or control of the inclination angle of the processed part wire electrode 18A, the forming process for the correction or regeneration and the finishing surface addition are performed. It can be carried out in a state cutting and grinding resistance is not.
[0029]
However, in the case of a ball end mill having a recess or a groove at the base part of the tip ball as shown in FIG. 6, the part cannot be processed with the linear processed part wire electrode 18A. In such a case, the machining portion wire electrode 18A is cut in the middle portion or the like in the middle, and while the wire electrode is fed out from the guide device 19, the tip is opposed to the peripheral surface of the tool 8 to perform electric discharge machining of the concave groove portion or the like. However, if necessary, a rod-like electrode that can be fed in a horizontal direction so as to be swingable may be provided as an accessory device.
[0030]
When the correction or regenerative forming process of the tool 8 by wire electric discharge machining and the finishing process of the forming surface are completed, the work table 12D to which the wire electric discharge machining tank 15 is attached is removed from the machining table receiver 13 and the original auxiliary Returned to the table receiver 14D, the work table 12A to which the workpiece 11A that was being processed is attached, or the work table to which another desired workpiece to be processed is attached is transferred onto the machining table receiver 13. Then, predetermined machining is resumed on the workpiece.
[0031]
【The invention's effect】
As described above, according to the present invention, it is not necessary to remove, attach, and position the worn tool, and the time required for correction or remanufacturing can be greatly shortened. It is possible to return to the cutting process with no cutting accuracy. In addition, the correction or re-forming process and the finishing process of the forming surface of the tool of the present invention are a processing method without cutting or grinding resistance by wire electric discharge machining, and a processing method capable of processing a cemented carbide. With the tool made of a hard alloy being attached to the main shaft, the correction or re-forming process and the finishing process of the forming surface can be performed without deterioration in accuracy, and the use efficiency of the machining center can be greatly improved.
[Brief description of the drawings]
FIG. 1 is a front view for explaining a schematic configuration of a machine part of a machining center according to the present invention.
FIG. 2 is a plan view of a wire electric discharge machining portion for re-forming a tool.
FIG. 3 is a side view of one tool and a front view of a blade tip.
FIG. 4 is a side view of another tool and a front view of the blade tip.
FIG. 5 is a side view of another tool and a front view of the blade tip.
FIG. 6 is a side view of another tool and a front view of the blade tip.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1, Bed 2, Base 3, Processing head 4, Column 5, Spindle 6, Rotating motor 7, Rotation, indexing means 8, Tool 9, Tool holder 10, Tool holding device 11A, 11B, Work piece 12A, 12B , 12C, 12D, work table 13, processing table receivers 14B, 14C, 14D, auxiliary table receiver 15, wire electric discharge processing tank 16, wire electrode supply / discharge device 17, travel path forming means 18, wire electrode 18A, processing part wire electrode 19, 20, guide devices 21, 22, stage 22A, moving mechanisms 23, 24, 24B, 25, pulley 26, machining fluid supply / discharge means

Claims (4)

In a machining center in which a workpiece of the workpiece setting means is disposed on a machining table directly below a spindle to which a tool is attached, and the workpiece is cut.
A wire electric discharge machining tank having a machining section travel path forming means in which a wire electrode is stretched in a predetermined tilt axis direction and a wire electrode supply / discharge means for supplying and collecting the wire electrode to the travel path forming means are integrated. Prepared as
When the tool is attached to the spindle, or when wear of the attached tool advances by a predetermined amount or more, the wire electric discharge machining tank is moved and arranged directly below the spindle, instead of the workpiece installation means, and the travel path forming means The machining section wire electrode capable of controlling the posture at a predetermined inclination angle in a direction perpendicular to the horizontal and vertical axes and the tool of the spindle are opposed to each other in the machining liquid immersion state. ,
An output terminal of a wire electric discharge machining power source is connected to the wire electrode of the travel path forming means and the tool, and a relative movement is given between the two by numerical control, and a forming process by the wire electric discharge machining and a finishing process of the shaping process surface are performed. The machining center tool correction or remanufacturing method, wherein the tool is sequentially applied while the tool is attached to the spindle. The method for correcting or regenerating a machining center according to claim 1, wherein the tool is a cemented carbide end mill tool. A plurality of worktables are exchanged and installed on a machining table support just below the main spindle to which the tool on the front of the machine body is attached, and the machining head attached with the main spindle is controlled and moved in three orthogonal directions relative to each table. In machining centers that cut workpieces,
The main spindle head has a built-in turning and indexing means for turning and controlling the main spindle.
One of the work tables includes a wire electric discharge machining tank having a wire electrode traveling path forming means for stretching the wire electrode in a predetermined tilt axis direction, and a wire electrode supply for supplying and collecting the traveling wire electrode. The travel path forming means is provided with a pair of positioning guide devices that can be opposed to each other at an interval in the direction of the inclined axis that forms the machining portion wire electrode. Is provided with an inclination angle position control means so that the machining part wire electrode can take a predetermined inclination angle with respect to the horizontal and vertical axes with respect to the tool attached to the lower end of the main shaft,
Furthermore, when the tool is attached to the spindle, or when the wear of the attached tool reaches a predetermined amount or more, replacement arrangement means for moving and arranging the wire electric discharge machining tank directly below the spindle, a processing portion wire electrode, and a tool, Power supply connecting means for connecting a wire electric discharge machining power source between the two facing each other in the state of machining liquid immersion, electric discharge machining between the wire electrode and the tool, the relative movement means, swiveling, indexing means and inclination angle position control means A machining center characterized in that a control device is provided for controlling the operation. A stage capable of adjusting and controlling at least two axes including at least a vertical axis with respect to one or both holding means of the pair of guide devices of the travel path forming means is provided as the tilt angle position control means of the processed part wire electrode. Machining center characterized by being

Images