JP5455187B2 - Counterbore tool for machining center - Google Patents

Description

  The present invention relates to a large-diameter and long counterbore dedicated tool which is mounted mainly on a horizontal main shaft of a horizontal shaft type machining center.

  In recent years, in the field of machining, each machining process performed by a single-function NC machine tool such as an NC lathe, an NC milling machine, an NC drilling machine, an NC boring machine, etc., called a machining center, The introduction of NC machine tools that can be automatically performed in a series of operations without changing the materials has been actively performed. This is because the introduction of a machining center makes it possible to process a difficult shape, which is difficult with conventional machining, or a process that requires setup change, with high efficiency and the same setup.

  By the way, as a cutting tool in the case of performing spot facing in a machining center, particularly a machining center called a horizontal axis type, a tool as described in Patent Document 1 below has been used. As shown in FIG. 5, this consists of an attachment portion that fits into the tool holder of the machining center spindle, a neck portion that follows the attachment portion, a head portion that is formed at the tip of the neck portion, and a blade portion that is attached to the head portion. In general, the head is formed with a small diameter D of about 20 to 50φ so that bending deformation or the like does not occur during machining even when attached to a horizontal main shaft of a horizontal axis machining center. The protruding length (also referred to as neck length) L, which is a portion that protrudes horizontally from the tool holder, is also formed in a short length of about 2 to 4 times the above D.

Japanese Utility Model Publication No. Hei 6-33607 (claim for utility model registration, FIG. 1)

  However, with a conventional counterbore tool having a small diameter and a short diameter, it has only been possible to counterbore a pilot hole with a small diameter such as a drill hole. In addition, depending on the shape of the workpiece, the protruding length L of the tool is too short to reach the predetermined machining site. For this reason, a replacement work for reversing the direction of the workpiece is performed, or only the counterbore processing is separately performed in a milling machine In many cases, the high efficiency of a machining center as an automatic processing machine is sacrificed, such as manually.

  The present invention is intended to solve such a problem, and has a large and long seat in which the diameter D of the cutter head is 60φ or more and the protruding length L is 7 times or more of the diameter D. Despite being a counterboring tool, it is lightweight and highly rigid, and even when mounted on the horizontal main spindle of a horizontal axis machining center, it is possible to perform counterbore machining with a high degree of accuracy, with almost no deflection, and with almost no deformation. For the purpose of provision.

The present invention to achieve the above object, the pilot protrusion 3 cylindrical cutter head 1 having the above diameter D60φ comprising fitted to the prepared hole in the center portion of the front surface, is formed on the rear surface center portion of the cutter head 1 A cemented carbide bar 8 which is joined at one end to the shrink fitting port 7 and has a columnar shape with a diameter smaller than that of the cutter head 1 and a required length, and a columnar shape substantially the same diameter as the cutter head 1. A body 9 having a shrink fitting port 10 for joining the other end of the cemented carbide bar 8 at the center of the front surface, and a joint 9 having a joint 11 extending rearward at the center of the rear surface, and a columnar shape. A counterbore tool comprising a shrink-fitting port 13 for joining the joint portion 11 of the body 9 to the front center portion of the front portion 12A, and a rear portion 12B formed of a holder 12 formed at the mounting portion to the machining center spindle. there are, of the cutter head 1 and the holder 12 And the diameter of the carbide bar 8 from the cutter head 1, by said cutter head 1 and the same diameter tool steel body 9 is interposed, the mounting portion 12B of the holder 12 from the tool entire length except in The machining center counterbore tool is characterized in that the protruding length L of the tool is 7 or more times longer than the cutter head diameter D.

  In the present invention, the cutter head 1 is preferably configured such that the pilot protrusion 3 provided at the front center portion thereof can be replaced according to the diameter of the pilot hole. Moreover, this cutter head 1 comprises the front side 1A provided with the pilot protrusion 3 and the rear side 1B provided with the shrink fit port 7 to which one end side of the carbide bar 8 is joined so as to be separable. desirable.

  The counterbore tool of the present invention having the above-described configuration is composed of the cutter head 1, the carbide bar 8, the body 9, and the holder 12, and these parts are joined together by shrink fitting. , And an integral counterbore tool having a predetermined protruding length L. Therefore, the holding rigidity of each part is high, and each part can be disassembled and replaced. Further, the cemented carbide bar 8 joined to the cutter head 1 is made of a cemented carbide alloy, so it is light in weight and high in strength. About 3).

  As a result, weight reduction and high rigidity of the entire tool are achieved, and a large and long counterbore tool in which the diameter D of the cutter head 1 is 60φ or more and the protruding length L is 7 times or more of the above diameter. Despite this, even if it is mounted on the horizontal spindle of a machining center, especially a horizontal axis machining center, there is almost no chatter vibration due to bending deformation, etc. be able to.

  In addition, since the carbide bar 8 positioned immediately behind the cutter head 1 is formed in a small diameter, when the cutter head 1 is brought close to the processing site Wa, a projection W ′ or the like from the workpiece W and the like. The interference is difficult to occur and the accessibility is excellent. Furthermore, the cutter head 1 can be applied to various spot facings with different pilot hole diameters by replacing the pilot projection 3. When the cutter head 1 is damaged such as cracks, Only the front side 1A of the cutter head 1 can be separated and replaced from the rear side 1B.

It is a front view explaining this invention counterbore tool. It is a side view explaining the cutter head of this invention counterbore tool. It is a vertical front view explaining the cutter head of the present invention counterbore tool. It is a front view explaining the Example of this invention. It is a vertical front view explaining an example of the conventional counterbore tool for machining centers.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a longitudinal side view showing an example of the embodiment of the present invention. As shown in FIG. 1, the long counterbore tool of the present invention includes a cutter head 1, a carbide bar 8, a body 9, and a holder 12.

That is, the cutter head 1 is formed of a tool steel in a cylindrical shape having a diameter D of 60φ and a length la of 70 mm. As shown in FIGS. 2 and 3, the cutter head 1 is fastened with two bolts 2 and 2 whose front side 1A and rear side 1B are axisymmetrically arranged. Once removed, they can be separated from each other.

  On the front side 1A of the cutter head 1, a pilot projection 3 is provided at the center of the front surface, and mounting seats 4a for counterbore cutting chips 4 are provided at positions 180 ° apart from the outer peripheral surface. Yes. The pilot projection 3 prevents the tool from swinging by fitting the projection into the prepared hole of the workpiece during the spot facing. The pilot protrusion 3 in the illustrated example is formed in a bolt shape, and the same portion 3 ′ is inserted into the hole 5 formed in the center of the front surface of the counterbore cutter 1, and a dedicated fixing bolt 6 is fastened. Is provided. Therefore, it is possible to replace the pilot projection 3 with the optimum size each time according to the diameter of the prepared work hole. The counterbore cutting tip 4 has a triangular shape with three sides formed on a cutting blade, and is screwed to the mounting seat 4a. On the rear surface side 1 </ b> B of the cutter head 1, a shrink fit mouth 7 is provided at the center of the rear surface.

  The cemented carbide bar 8 is a cemented carbide bar. In the illustrated example, the cemented carbide bar 8 is formed in a cylindrical shape having a diameter d of 24φ and a total length lb of 125 mm. One end side 8 ′ of the cemented carbide bar 8 is joined by shrink fitting by inserting its tip 25 mm into the shrink fitting opening 7 of the cutter head 1. Further, the other end 8 ″ of the cemented carbide bar 8 is joined by shrink fitting by inserting its tip 30 mm into a shrink fitting port 10 provided at the front center of the body 9 described later.

  The body 9 is formed of a tool steel in a cylindrical shape having the same diameter D60φ as the cutter head 1 and a length lc of 180 mm. In the central portion of the rear surface of the body 9, a joining portion 11 is formed in a cylindrical shape with a slightly small diameter (40φ in the illustrated example) and a required length (100 mm in the illustrated example) that extends straight rearward. Is formed.

  The holder 12 attaches the counterbore tool to the spindle of the machining center, and the front part 12A having the same diameter as the body 9 has a front part 12A and a joint part 11 of the body 9 at the front center part. A shrink fit port 13 for shrink fit joining is provided. The rear part 12B of the holder 12 is inserted into the main shaft of the horizontal axis machining center, that is, the key groove 14 that meshes with the key of the main shaft, the grip flange 15 that is gripped by the tool changer of the machining center, and the main shaft of the machining center. It is formed in the mounting part which consists of the taper-shaped shank 16.

  Note that the counterbore tool in the illustrated example is for carrying out counterbore machining with a diameter of 60φ on the electric joint of the vehicle coupler, and its protruding length L, that is, the cutter head 1 at the tip (the pilot protrusion 3 is inserted). To 440 mm, which is approximately 7.3 times as long as the diameter D (60φ) of the cutter head 1. It has become.

  In order to use the counterbore tool of the present invention having the above-described configuration, first, the counterbore tool is set at a designated place in the tool magazine of the horizontal axis machining center. On the pallet outside the machine, a workpiece (vehicle coupler) is attached with a dedicated jig. Next, the pallet to which the workpiece is attached is automatically carried into the machine by an automatic pallet changer. The counterbore tool of the present invention set in the tool magazine is selected by the NC program, and is mounted on the horizontal main shaft of the horizontal axis machining center by an automatic tool changer (ATC).

  Subsequently, as shown in FIG. 4, the spindle 17 of the horizontal axis machining center is controlled by the NC program in the front-rear direction (X-axis), the left-right direction (Y-axis), and the vertical direction (Z-axis). The counterbore position is positioned so that the tip of the cutter head 1 of the counterbore tool of the present invention mounted on the head is in horizontal contact with the vertical electric joint Wa of the vehicle coupler W that is the workpiece. At this time, the pilot protrusion 3 is inserted into the pilot hole 18 of the bolt already formed on the electric connecting seat Wa and is in a fitted state. Further, since the portion near the cutter head 1 of the counterbore tool is a small diameter portion formed of the carbide bar 8, it interferes with the projection W ′ or the like from the vehicle coupler W which is a workpiece. Can be avoided, and the tip of the long tool can be smoothly approached to the electric connecting seat Wa.

  Next, rotation and feed speed are commanded to the spindle 17 of the machining center by the NC program. As a result, the counterbore tool of the present invention mounted on the main shaft 17 starts moving forward while rotating, and the two cutter heads 1 around the bolt pilot holes 18 already formed in the electric train Wa. A counterbore 19 having a required depth of 60φ is formed by the triangular cutting tips 4 and 4. Incidentally, the cutting conditions at this time were cutting speed: 15 m / min, rotation speed: 80 rpm, feed speed: 2 mm / min, cutting depth: about 7 mm × 4, processing time: about 15 minutes. The dimensional accuracy of the counterbore 19 formed in this way is low in weight and high rigidity despite the fact that the counterbore tool of the present invention used has a large diameter and a long length. Even when mounted on the horizontal main shaft, chatter vibration or the like due to bending deformation does not easily occur during processing, and it has high accuracy with almost no dimensional error.

l Cutter head lA Front side of cutter head 1B Rear side of cutter head 3 Pilot projection 4 Cutting tip 8 Carbide bar
9 Body 12 Holder 12B Holder spindle mounting part D Diameter of cutter head L Projection length of counterbore tool

Claims (3)

A cutter head 1 diameter D is equal to or greater than 60φ cylindrical with a pilot protrusion 3 to be fitted to the prepared hole in the center of the front, the shrink-opening 7 formed in rear surface center portion of the cutter head 1 A cemented carbide bar 8 which is joined to one end side and has a cylindrical shape with a diameter smaller than that of the cutter head 1 and a required length, and a cylindrical shape having the same diameter as the cutter head 1, A tool steel body 9 provided with a joint 11 that is provided with a shrink fitting port 10 that joins the other end side of the carbide bar 8 and that extends rearward at the center of the rear surface thereof, and a front part 12A having a cylindrical shape. A counterbore tool comprising a shrink fitting port 13 for joining the joint portion 11 of the body 9 at the center of the front surface, the rear portion 12B comprising a holder 12 formed on the mounting portion to the spindle of the machining center, The cutter head between the cutter head 1 and the holder 12 More diameter of carbide bar 8, by said cutter head 1 and the tool steel body 9 of the same diameter is interposed, protruding length of the tool excluding the mounting portion 12B of the holder 12 from the tool overall length L is the Machining center for counterbore tool, characterized in that it is 7 times or more elongated cutter head 1 diameter D.   2. The counterbore tool for a machining center according to claim 1, wherein the cutter head 1 is configured such that a pilot protrusion 3 provided at a front center portion thereof is replaceable in accordance with a diameter of the pilot hole.   The cutter head 1 is configured such that a front side 1A provided with a pilot protrusion 3 and a rear side 1B provided with a shrink fit port 7 to which one end side of a carbide bar 8 is joined can be separated from each other. A counterbore tool for a machining center according to 1 or 2.

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