JP3851899B2 - Rotary cutting tool with blade runout adjustment mechanism - Google Patents

Description

  The present invention relates to a rotary cutting tool such as a face mill and a corner milling cutter having a blade runout adjustment mechanism.

  In finishing milling, high precision edge position accuracy is required. If the runout accuracy of each blade is poor, adverse effects such as deterioration of the roughness of the finished surface, so-called chatter during processing, occurrence of flash, and shortening of the tool life will occur.

Therefore, the blade deflection adjusting mechanism for Slow-away cutter is devised. Examples of documents relating to the blade runout adjustment mechanism include the following Patent Documents 1 to 4.
Japanese Patent Laid-Open No. 2001-252813 Japanese Utility Model Publication No. 7-27719 Utility model registration No. 3064324 JP-T-2002-516762

  The front milling of Patent Document 1 is such that the back surface of the throw-away tip (hereinafter also simply referred to as a tip) and the side surface on the tool center side are seated on a tip mounting seat provided on the outer periphery of the tip of the tool body, and the side surface on the tool proximal side of the tip Is configured to be received by a pressing pin that is moved with an adjusting screw. However, in this structure in which the pressing pin moves in the tool axis direction, the position reference of the chip in the tool axis direction is not fixed, and the blade runout adjustment is performed for all the chips every time the chip is replaced or the position of the cutting edge is replaced. This requires adjustment time. There is a similar adjustment mechanism that displaces the taper surface of the wedge to cause the tip to protrude in the tool axis direction, but this also has the same drawbacks.

  Further, the cutter of Patent Document 2 is provided with an elastic deformation portion on an adjustment piece fixed to the main body with a wedge, and the elastic deformation portion is used as a position reference in the tool axis direction of the tip, and this is elastically deformed with a bolt screwed into the adjustment piece. In this structure, since the tip is retracted by the elastic restoring force of the elastic deformation portion, the backward displacement is not reliable and is difficult to adjust. In addition, deformation of the elastically deformable portion beyond the yield point and fatigue of the elastically deformable portion due to long-term use can be considered, and thereby the elastically deformable portion may not return to its original state or may be damaged.

  Further, in the groove milling blade run-out adjustment mechanism disclosed in Patent Documents 3 and 4, a part of a pocket (blade groove) wall on which a chip is mounted can be elastically deformed, and a part of the pocket wall is adjusted with an adjusting screw. The tip of the tip that is in contact with the wall surface is displaced by being pressurized and elastically deformed with a ball that receives the force of this force, but this also lacks the reliability related to the restoration of the pocket wall, like the elastically deformed portion of Patent Document 2. . If the deformation remains and the pocket wall does not return to its original position, the next blade runout adjustment will require extra pressure to ensure the same amount of adjustment as before, and if this is repeated, it will eventually yield. Beyond that point, the pocket wall can become unrecoverable or damaged.

  In addition, if the thickness of the part to be elastically deformed is not strictly controlled, the pressure applied for elastic deformation changes for each blade, and therefore a very high degree of difficult processing is required, and the processing time, etc. Will spend too much.

  In addition, the conventional cutter with blade run-out adjustment mechanism is not reliable enough to fix the tip when the adjustment mechanism receives the load applied to the tip during rough machining, and the position of the axial reference surface (displaceable surface) Therefore, there are cases where the reference plane position is forced to be adjusted even when used for roughing, which is not suitable for roughing.

  This invention is capable of stably performing roughing and finishing with the same tool, and enabling accurate adjustment in a short time with a simple structure when blade runout accuracy is required. It is an issue.

  In order to solve the above-described problems, in the present invention, a cutter body having a plurality of blade grooves on the outer periphery of the tip, a throw-away tip that is attached to each of the blade grooves to form a cutting edge, and the throw-away tip thereof The rotary cutting tool is configured by including a clamping means for detachably fixing the cutter to the cutter body and a blade runout adjusting screw of each throw-away tip. Each blade groove is provided with three seating surfaces for positioning the throwaway tip in the tool rotation direction, radial direction and axial direction by seating the rear side of the throwaway tip and two adjacent side surfaces, and adjusting the blade runout Screw the screw into the blade groove forming part of the cutter body in the axial direction, and displace one end of this blade run-out adjusting screw back and forth from the position of the axial positioning seating surface of the blade groove to make the axial positioning seat of the blade groove Axial positioning of the throw-away tip by the surface and axial positioning of the throw-away tip by one end of the blade run-out adjusting screw can be performed.

  This rotary cutting tool is provided with a rotation operation portion for the screw at the head of the blade runout adjustment screw, and the rotation runout portion is exposed to the outside so that the blade runout adjustment screw is directed to the front of the cutter. It is preferable that the screw is screwed in from the front side and the top surface of the blade run-out adjusting screw is brought into contact with the side surface of the throw-away tip on the tool proximal side.

  Since the rotary cutting tool of the present invention can perform the axial positioning of the throw-away tip by properly using the axial positioning seating surface of the blade groove and the adjustment screw, in rough machining, the blade run-out adjustment screw is retracted to position the tip. It is possible to adjust the blade runout in the axial direction by operating the adjusting screw only for the chip having a low blade runout accuracy in the finishing process.

  In this rotary cutting tool, in rough machining, the blade edge is positioned by the seat surface of the blade groove, and the position adjustment of the reference surface by the adjustment mechanism (adjustment for absorbing variations in the position of the reference surface) is not required. In addition, since the three surfaces of the chip are constrained by the blade groove, roughing can be performed stably.

  On the other hand, in finishing, the tip is temporarily positioned on the seat surface of the blade groove to check the blade runout. If there is a tip with poor runout accuracy, the tip is displaced with an adjusting screw to adjust the blade runout. Since the seat surface of the blade groove serves as the axial position reference during temporary positioning, only the blade that has been retracted beyond the specified value with respect to the cutting edge located at the forefront needs to be pushed forward with the adjusting screw. There is no need to adjust over the entire blade. In addition, since the adjustment screw is used as the axial position reference, the reliability of the return, which is a problem when using the elastically deformable member, is ensured, and the adjustment can be performed reliably in a short time. Since the blade runout is adjusted by the adjusting screw, the adjusting mechanism is not complicated.

  In addition, since it can be used for both roughing and finishing, it is not necessary to use two types of cutters, which is advantageous in terms of cost reduction and tool management.

  Hereinafter, an embodiment of a rotary cutting tool of the present invention will be described with reference to FIGS. 1 to 6. 1 to 4 show a first embodiment. This rotary cutting tool (the corner milling cutter in the figure) includes a cutter body 1, a throw-away tip 2, clamp means 3 for fixing the throw-away tip 2 to the cutter body 1, and an adjustment screw 4 for adjusting blade run-out. It consists of and.

  A plurality of blade grooves 5 for mounting the throw-away tip 2 are provided on the outer periphery of the tip end of the cutter body 1 at intervals in the circumferential direction. As shown in FIG. 4, the blade groove 5 is provided with three seating surfaces for positioning and restraining the tip in three directions of the tool rotation direction, the radial direction, and the axial direction, that is, the back surface 2a of the throw-away tip 2. , A seating surface 5b for seating the side surface 2b placed on the tool center side, and a seating surface 5c for seating the side surface 2c placed on the tool base end side.

  The clamping means 3 includes a countersunk head clamping screw 3a that passes through the center hole of the throw-away tip 2 and locks the head to the inlet of the center hole, and a screw hole 3b that is opened at the position of the seat surface 5a (see FIG. 4). ). The clamp screw 3a is screwed into the screw hole 3b, and the throw-away tip 2 seated on the seat surface of the blade groove 5 is fastened with the clamp screw 3a to be fixed to the cutter body 1. A gap g (see FIG. 5) necessary for blade runout adjustment is generated between the center hole of the throw-away tip 2 and the clamp screw 3a that passes through the hole.

  The adjustment screw 4 is provided with rotation operation portions (spanner engagement grooves) 4b and 4c on both the top surface 4a and the outer periphery of the head, and the cutter body with the adjustment screw 4 facing forward. One blade groove forming portion is screwed in the axial direction from the front side, and the screw is rotated so that the top surface 4a is displaced from the position where the seat surface 5c is cut out to the front and back of the seat surface 5c. If necessary, the adjusting screw 4 is preferably slightly inclined with respect to the axis of the tool so that the top surface 4a is in close contact with the side surface 2c of the throw-away tip 2.

  It is desired that the blade runout of the rotary cutting tool be within a position error of 10 μm, more preferably within 5 μm, and the blade runout adjustment by the adjusting screw 4 can meet the demand.

  The exemplary rotary cutting tool configured in this manner draws the top surface 4a of each adjustment screw 4 to a position somewhat retracted from the seat surface 5c. In this state, the throwaway tip 2 is clamped by positioning the two side surfaces 2b and 2c adjacent to the back surface 2a of the tip with the seating surfaces 5a to 5c and setting them in the respective blade grooves 5, and passing them through the center hole of the tip. The screw 3 a is tightened to fix the throw-away tip 2 to the cutter body 1. If the axial positioning of the throw-away tip 2 by the seating surface 5c is not hindered, the top surface 4a of the adjusting screw 4 may be in contact with the side surface 2c of the tip.

  Roughing is performed using the tool in this state. Further, when high blade runout accuracy is required in finishing, the throwaway tip 2 is temporarily positioned on three seating surfaces 5a to 5c and attached to the blade groove 5, and then the runout of each blade is confirmed. . Then, with the cutting edge as a reference, the blade at a position retracted from the reference blade is loosened with the clamp and pushed out by the adjusting screw 4, and re-clamped at the position where the blade runout is corrected. Adjustment is not necessary for a blade that does not shake, and only one blade may be adjusted if the accuracy of only one of the blades is poor.

  FIG. 6 shows an example in which a clamp piece (wedge) 3 c is used as the clamp means 3. The clamping means for fixing the throw-away tip 2 may be the illustrated clamping piece that is advanced and retracted by the propulsion screw 3d, and the present invention can also be applied to the front milling machine of FIG.

  Furthermore, although the illustrated tool operates the adjusting screw 4 on the front side of the tool, the adjusting screw 4 can be operated from the base end side (rear side) of the main body depending on the shape of the cutter body 1. .

  In addition, the throw-away tip 2 in FIG. 1 is obtained by brazing a diamond sintered body 2d to a base material, but the throw-away tip 2 to be used is cBN sintered instead of the diamond sintered body 2d. What joined the body, the cemented carbide chip shown in FIG. 3, etc. may be sufficient and it does not specifically limit.

Side view showing an example of the rotary cutting tool of the present invention Front view of the tool in FIG. The perspective view which shows a part of tool of FIG. 1 is a perspective view showing a part of the tool of FIG. 1 with the throw-away tip removed. 3 is a perspective view showing the state of FIG. 3 with the cutter body omitted. The perspective view which shows a part of other embodiment

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cutter main body 2 Throw away tip 2a Back surface 2b, 2c Side surface 3 Clamp means 3a Clamp screw 3b Screw hole 3c Clamp piece 4 Adjustment screw 4a Top surface 4b, 4c Rotation operation part 5 Blade groove 5a, 5b, 5c Seat surface

Claims (2)

A cutter body provided with a plurality of blade grooves on the outer periphery of the tip, a throw-away tip that is mounted on each of the blade grooves to form a cutting edge, and a clamping means that detachably fixes the throw-away tip to the cutter body; A blade run-off adjusting screw for each throw-away tip is provided, and the blade groove seats the rear side of the throw-away tip and two adjacent side surfaces to position the throw-away tip in the tool rotation direction, radial direction, and axial direction. one of having a seat surface, the blade deflection adjusting screw is screwed axially into the blade groove forming portion of the cutter body, before and after the position of the axial-positioning seat for one end of the blade deflection adjusting screw is the gullet a displaceable structure, by selectively using the axial positioning seat surface and the blade runout adjustment screw, the axial positioning of the cutting insert according to the axial positioning bearing surface, the blade vibration Blade deflection adjusting mechanism with the rotary cutting tool and to perform the axial positioning of the cutting insert according to one of the adjusting screws. The cutter body is provided with a rotation operation section for the screw on both the top surface and the outer periphery of the head, and the rotation operation section is exposed to the outside so that the blade movement adjustment screw faces the head. The rotary cutting tool with a blade run-out adjusting mechanism according to claim 1, wherein the blade run-out adjusting screw is screwed from the front side and the top surface of the blade run-out adjusting screw is brought into contact with the side surface of the throw-away tip on the tool proximal end side.

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