JP6198158B1 - Centered tool holder and machining method - Google Patents

Abstract

An object of the present invention is to obtain a machining center that can perform a next machining step immediately after centering a workpiece. A center-equipped tool holder 1 in which a center 1d having a conical surface 1e is provided on a holder portion 1c. Further, the center-equipped tool holder 1 to which the tool 3 used in the next step is attached is grasped by the main shaft, the center-equipped tool holder 1 is inserted into the next machining center hole 5a, and one of the conical surface 1e and the next machining center hole 5a is inserted. When only the part contacts, the conical surface 1e pushes the next machining center hole 5a as the main shaft moves in the Z-axis direction, the conical surface 1e contacts the entire circumference of the next machining center hole 5a, and the centering is performed. It is confirmed by checking the current value of the spindle servo that the movement of the spindle has stopped after completion, and the spindle servo is stopped to clamp the workpiece 5. [Selection] Figure 1

Description

  In the present invention, a workpiece provided with a circular hole (hereinafter referred to as a “next machining center hole”) having a center at a position to be a center of machining performed in the next process is grasped by a clamp mechanism and used as a spindle of a machining center. When a tool such as a cutting tool or a grinding tool is attached and processed, the workpiece can be centered and clamped to immediately perform the next processing step.

  Conventionally, in order to grasp the workpiece without tilting, the workpiece provided with a conical center hole at the end is aligned with a center pin having a truncated cone-shaped tip, and the moving member grips the workpiece. There is an invention of a chuck device that converts this into movement in the direction in which the workpiece is drawn, and fits the center hole and the center pin to center the workpiece (see, for example, Patent Document 1).

  The above-described invention has a problem that a workpiece cannot be machined by attaching a tool such as a milling cutter or an end mill to the spindle. In addition, it is difficult to center a thin workpiece and grasp the workpiece, and the working member is configured to pull in the workpiece as it grips the outer periphery of the workpiece. There was a problem that could not center the non-work piece.

  In order to solve the above problem, an experiment was conducted in which a centering jig having a frustoconical center was attached to a tool holder, and this was grasped by a spindle of a machining center and inserted into a next machining center hole of a workpiece. As a result, when the center of the next machining center hole and the axis of the main shaft (hereinafter referred to as “bore and main shaft”) are deviated, the conical surface pushes the workpiece along with the movement of the main shaft in the axial direction. -It was confirmed that the movement of the spindle in the axial direction stopped when both spindle centers coincided.

  When the contact between the conical surface of the centering jig and the center hole of the next machining is not a point but a circle, the center of the hole and the spindle are aligned. At this time, the servo moves the spindle in the axial direction. It was confirmed that the current value of the motor (hereinafter referred to as “spindle servo”) suddenly increased. As a result of this experiment, it became possible to know the coincidence of the center of the hole and the spindle by checking the increase in the current value of the spindle servo.

  However, the configuration in which the centering jig is attached to the tool holder has a problem that the type or number of tools stored in the tool magazine needs to be reduced by the amount of the tool holder to which the centering jig is attached. Also, after the process of centering the workpiece, it is necessary to store the tool holder with the centering jig attached in the tool magazine and to grasp the tool holder with the tool to be used in the next process on the main spindle. It was necessary to further devise in terms of simplifying the process and shortening the work time.

JP 2012-24862 A

An object of the present invention is to provide a machining center capable of centering a workpiece without reducing the types and number of tools stored in the tool magazine. Furthermore, after the centering of the workpiece , the next machining process can be performed immediately without changing the tool at a predetermined position around the center of the spindle when the centering is completed. Therefore, it is to obtain a machining center that simplifies the work process and shortens the work time.

A center-equipped tool holder in which a center having a conical surface is fixedly attached to the holder portion. In addition, the centered tool holder to which the tool used in the next process is attached is grasped by the spindle, the centered tool holder is inserted into the center hole of the next machining, and when the conical surface comes into contact with the workpiece, the spindle is moved to that axis. The conical surface pushes the contact portion with the workpiece by the force to move in the direction so that the workpiece is moved. After confirming that both the hole and spindle centers match , check the increase in the spindle servo current value, stop the spindle servo and perform the centering method to clamp the workpiece, then immediately start the next machining It is set as the processing method which performs a process .

It has become possible to machine a workpiece by attaching a tool to the spindle, center a thin workpiece and grasp it, or center a workpiece whose outer shape is not circular. In addition, the type and number of tools stored in the tool magazine need not be reduced by the number of tool holders with a centering jig attached. Furthermore, after performing centering, it becomes possible to start the next machining process immediately at a predetermined position around the position of the spindle when the centering is completed , simplifying the work process In addition, the working time could be shortened.

FIG. 2 is a front view of a center-equipped tool holder and a cross-sectional view of a workpiece in a state in which both holes and spindle centers coincide with each other. It is the front view of the tool holder with a center in the state which is performing the next processing process, and sectional drawing of a workpiece.

  A tool holder having a configuration in which a tool is attached by using a nut capable of inserting the tool shank into the holder portion and protruding the blade portion of the tool. Further, the tapered portion is inserted into the main spindle of the machining center so that the main spindle grasps the tool holder. Further, the flange portion is held by an exchange arm, and the tool holder is exchanged between the spindle and the tool magazine.

Then, a center having a conical surface is fixedly attached to the holder portion, and this is used as a center-equipped tool holder. Regarding the angle between the central axis of the centered tool holder and the conical surface (hereinafter referred to as “conical angle”), when the conical surface comes into contact with the workpiece , the conical surface is moved by the force that moves the main shaft in the axial direction. There pressing contact portions of the workpiece, as the movement in the axial direction of the main shaft, but if possible, but are not dwell particularly pressing it with industrial crops in a direction bore-spindle both heart match, the result of the experiment According to the above, it was preferable to set the cone angle to 10 to 30 degrees.

Furthermore, it is a centering method performed before the next machining step is performed on a workpiece provided with a next machining center hole in advance, and a centered tool holder to which a tool used in the next step is attached is grasped by the spindle. The process of inserting the centered tool holder into the center hole of the next machining , and the spindle servo movement when the hole and spindle centers coincide, and the spindle servo current value rises. a step of checking an increase in, check the increase in the current value of the spindle servo, main shaft when the step of clamping the Engineering crops stops the spindle servo, after the centering method comprising the city, completing the centering A machining method in which the next machining process is performed immediately on a predetermined position around the position without changing the tool .

  Here, it is assumed that the next machining center hole has a diameter larger than the minimum diameter of the conical surface of the center and smaller than the maximum diameter. When the hole and the spindle are displaced from each other, the conical surface pushes the workpiece as the spindle moves in the axial direction, and the holes and the spindle become coincident. In either case, the movement of the spindle stops when the hole and spindle centers coincide. At this time, since the current value of the spindle servo increases, this current value is checked, the spindle servo is stopped, and the workpiece is clamped.

  Embodiment 1 of the center-equipped tool holder 1 will be described with reference to FIGS. The tool holder has a tapered portion 1a, a flange portion 1b, and a holder portion 1c. And the tool holder of the structure which fixes the tool 3 to the holder part 1c using the nut 2 which can insert the shank of the tool 3 in the holder part 1c and can protrude the blade part of the tool 3 was used.

Furthermore, a center 1d having a conical surface 1e is fixed and attached to the outer periphery of the holder portion 1c, and this is used as a tool holder 1 with a center. The minimum diameter B of the conical surface 1e of the center 1d is smaller than the diameter D of the next machining center hole 5a of the workpiece 5, and the maximum diameter C of the conical surface 1e is larger than the diameter D of the next machining center hole 5a. The cone angle A was 15 degrees .

  The second embodiment is a centering method that is performed before a plurality of holes are drilled at predetermined positions around the center hole 5a of the next machining center by the cutting tool 3 attached to the spindle of the machining center. The machining magazine of the machining center houses a large number of tool holders, holds the flange portion 1b by an exchange arm, and is configured to exchange the tool holder between the spindle and the tool magazine.

  The tool magazine stores both the centered tool holder 1 and the centerless tool holder. In Example 2, a tool 3 used in the next step is attached to the center-equipped tool holder 1 in advance, a taper portion 1a is inserted into the spindle of the spindle, and a pull stud (not shown) attached to the tip of the taper portion 1a is attached. By pulling, the centered tool holder 1 is grasped by the main shaft so that the tapered portion 1a is in close contact with the hole of the spindle.

  Next, the centered tool holder 1 is inserted into the next machining center hole 5 a of the workpiece 5. By performing numerical control, the spindle is moved in the X-axis and Y-axis directions, and the axis of the spindle is brought closer to the center of the next machining center hole 5a of the workpiece 5. The diameter D of the next machining center hole 5a is larger than the minimum diameter B of the conical surface 1e of the center 1d. For this reason, both the hole and the main axis may be displaced within a range smaller than (D−B) / 2.

Subsequently, the spindle servo is driven to move the spindle in the Z-axis direction, and the centered tool holder 1 is inserted into the next machining center hole 5a. When the center of the hole and the main shaft is shifted, only the conical surface 1e and a part of the next machining center hole 5a are in contact with each other, and the main shaft servo moves the main shaft in the Z-axis direction as the main shaft moves in the Z-axis direction. Due to the force, the conical surface 1e pushes the contact portion with the next machining center hole 5a, and the workpiece 5 moves in a direction in which both the hole and the spindle center coincide. In either case, the movement of the spindle stops when the contact between the conical surface 1e of the centering jig and the next machining center hole 5a is not a point but a circumference.

  When the contact between the conical surface 1e of the centering jig 1d and the next machining center hole 5a is not a point but a circumference, both the holes and the spindle are aligned. At this time, the movement of the spindle in the Z-axis direction stops and the spindle servo current value increases. Therefore, the current value of the spindle servo is checked to confirm its rise, the spindle servo is stopped, and the workpiece 5 is clamped. In this way, the workpiece 5 can be clamped with the centering of the workpiece 5 completed.

  After the centering is performed and the workpiece 5 is clamped, drilling with the tool 3 is performed without replacing the centered tool holder 1. Since the center position of the spindle when the centering is completed is also the center position of the next machining center hole 5a, by performing numerical control, a hole is drilled at a predetermined position around the next machining center hole 5a. It is easy.

  In this embodiment, the cutting tool 3 is attached to the main shaft, but other tools such as a grinding tool can be attached for processing. According to the present invention, it is possible to center a thin workpiece or a non-circular workpiece, and it is not necessary to reduce the types and number of tools stored in the tool magazine. Furthermore, the next machining process can be started immediately after the centering, and the work process can be simplified and the work time can be shortened.

  The present invention is used not only in the industry for manufacturing and selling tool holders, but also in the industry for manufacturing and selling machine tools and the industry for manufacturing and selling machined products.

DESCRIPTION OF SYMBOLS 1: Tool holder with a center 1a: Tapered part 1b: Flange part 1c: Holder part 1d: Center 1e: Conical surface 2: Nut 3: Tool 5: Workpiece
5a: Next machining center hole

Claims (2)

A tool holder configured to insert a tool shank into a holder portion and attach the tool, and fix and attach a center having a conical surface to the holder portion, and a spindle holding the tool holder in its axial direction A tool holder with a center , wherein the conical surface pushes a contact portion with a workpiece by a moving force to move the workpiece. Centering that is performed before the next machining step is performed on a workpiece that has been previously provided with the next machining center hole, with a circular hole having the center at the position to be the center of machining performed in the next process as the next machining center hole. A method,
Fitted with a tool to be used in the next machining step, the steps of inserting a step of grasping the center with tool holder according to claim 1, wherein the machining center of the main shaft, said tool holder with a center to the next machining center hole, the following When the center of the machining center hole and the axis of the spindle coincide with each other, the movement of the spindle stops, and the current value of a servo motor that moves the spindle in the axial direction (hereinafter referred to as “spindle servo”) increases. a step of checking the increase in the current value of the spindle servo, check the increase of the current value, the step of clamping the front Symbol workpiece to stop the spindle servo, after the centering method comprising city,
A machining method in which the next machining step is performed immediately without replacing the tool at a predetermined position around the position of the spindle when centering is completed.

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