JP2015024460A - Cutting tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cutting tool, e.g. a boring cutter having a mechanism of adjusting the position of the tip in which reaction force in cutting is received stably by the tool body.SOLUTION: The cutting tool includes a tool body, a cartridge equipped with a cutting insert in the tip part, and a tip position adjustment mechanism. The cartridge is arranged in the bottom surface part of the tool body. The tip position adjustment mechanism comprises a combination of a wedge arranged between the receive surface at the rear end of the cartridge and a seat wall formed in the tool body and an adjustment screw which displaces the wedge. The adjustment screw includes a small-diameter part which is engaged loosely in a shaft hole provided in the wedge, a screw part screwed into a screw hole provided in the tool body and provided in the outer periphery, and a contact surface brought into contact with the wedge.

Description

  The present invention relates to a cutting tool such as a boring cutter having a cutting edge position adjusting mechanism.

  As a cutting tool provided with a cutting edge position adjusting mechanism, those described in Patent Document 1 and Patent Document 2 below are known.

  The cutting tool (boring cutter) described in Patent Document 1 uses a wedge inserted between a tool body and a cutting insert mounted on a support seat of the tool body as a cutting edge position adjusting mechanism, and the wedge. A combination of a wedge moving screw for propelling (a so-called double screw in which a reverse screw is cut on the outer periphery on one end side and the outer periphery on the other end side) is provided.

  Moreover, the cutting tool described in Patent Document 2 is provided with a tool for adjusting the position of the blade edge so that a cartridge to which a cutting insert is attached is attached to the tool body so that the position can be adjusted, and the cartridge is moved directly by an adjusting screw.

JP 2006-150491 A JP 2004-114259 A

  In the edge position adjusting mechanism disclosed in Patent Documents 1 and 2, the wedge moving screw and the adjusting screw receive the cutting reaction force generated when machining the workpiece with the cutting insert in the direction perpendicular to the axis. For this reason, the position of the cutting insert during processing tends to be unstable.

  In the blade edge position adjusting mechanism of Patent Document 1 combining a wedge and a wedge moving screw (double screw), a sliding clearance of about 5/100 mm to 10/100 mm is provided between the wedge and the wedge guide surface provided on the tool body. It is formed.

  For this reason, the cutting reaction force cannot be received by the tool body unless the wedge moving screw is bent to press the wedge against the wedge guide surface. If the wedge moving screw is not sufficiently bent at this time, the reaction force is received by the wedge moving screw.

  In addition, in the method of bending the wedge moving screw and pressing the wedge against the wedge guide surface, the reaction force is received by the tool body in a state where the wedge does not sufficiently contact the wedge guide surface. Even if the wedge is pressed, the position holding of the cutting insert becomes unstable.

  In order to eliminate this problem, it is necessary to increase the processing accuracy and bring the sliding gap as close to zero as possible, which makes it difficult to improve mass productivity and reduce costs.

  Also in the blade edge position adjusting mechanism of Patent Document 2 in which the cartridge is moved directly with an adjusting screw for positioning, the adjusting screw receives the reaction force when the cutting insert is pressed against the workpiece in the direction perpendicular to the axis. Further, in this mechanism, since the adjustment screw and the cartridge are in point contact, the reaction force is not stably received, and the position of the cutting insert during processing is likely to be unstable.

  An object of the present invention is to enable the tool body to stably receive the reaction force during the cutting process.

In order to solve the above problems, in the present invention, a tool body, a cartridge having a cutting insert attached to the front end portion and a receiving surface formed at the rear end, and a blade edge position adjusting mechanism for changing the position of the cartridge are provided. Prepared,
The cartridge is installed on the bottom surface of the tool body;
The blade edge position adjusting mechanism is disposed between the receiving surface of the cartridge and a seat wall formed on the tool body so as to be movable along the bottom surface of the tool body while contacting the receiving surface and the seat wall. It is configured by combining a wedge and an adjusting screw that displaces the wedge,
The adjustment screw has a male screw formed on a small diameter portion whose outer diameter is loosely fitted in a shaft hole provided in the wedge and smaller than an inner diameter of the shaft hole, and on an outer periphery screwed into a screw hole provided in the tool body. The screw portion having a larger diameter than the small-diameter portion and a contact surface to be brought into contact with the wedge are provided.

  In the cartridge, the side with the cutting insert is considered as the front, and the side opposite to the side with the cutting insert is considered as the back.

  In the cutting tool of the present invention, the reaction force during cutting is stably received by the tool body.

It is a side view which shows an example of the cutting tool of this invention. It is an enlarged bottom view of the cutting tool of FIG. It is the side view of the front end side which looked at the cutting tool of FIG. 1 in the arrow A direction of FIG. It is the side view of the front end side which looked at the cutting tool of FIG. 1 in the arrow B direction of FIG. It is sectional drawing of the position along the VV line of FIG.

  Embodiments of a cutting tool according to the present invention will be described below with reference to FIGS.

  The illustrated cutting tool 1 includes a tool body 2, two cartridges 5 and 6 each having a cutting insert 3 and 4 mounted at the tip, and a blade edge position adjusting mechanism 7 that changes the tool radial direction position of each cartridge, 8 is provided.

  As shown in FIG. 2, the two cartridges 5 and 6 are both incorporated in guide grooves 2 a and 2 b provided on the bottom surface of the tool body 2 so as to be slidable in the tool radial direction. The blade edge position is adjusted by the tool radial slide of the cartridge.

  As shown in FIG. 5, the cartridge 5 is provided with a bolt hole 5 a that is long in the tool radial direction, and the cartridge 5 is within a range of flexibility generated between the bolt hole 5 a and the clamp bolt 9 inserted through the hole. Is adjusted (ie, the cutting edge position).

  Then, the cartridge 5 is fixed at the adjustment position by the clamp bolt 9.

  5 b in FIG. 5 is a seat hole for receiving the head of the clamp bolt 9 and is provided in the cartridge 5. This seat hole 5b is also a long hole in the tool radial direction that causes adjustment for adjustment with the head of the clamp bolt. Reference numeral 5 c denotes a receiving surface provided at the rear end of the cartridge 5.

  The cartridge 6 has the same structure as that of the cartridge 5 and is fixed to the adjusted position by the clamp bolt 9.

  The blade edge position adjusting mechanism 7 attached to the cutting insert 3 displaces the wedge 10 disposed between the receiving surface 5c at the rear end of the cartridge 5 and the seat wall 2c formed on the tool body 2, and the wedge. The adjusting screw 11 is combined.

  The wedge 10 is guided by a seat wall 2c and a groove wall 2d (see FIG. 2) provided so as to face the seat wall 2c, and comes into contact with the receiving surface 5c at the rear end of the cartridge 5 and the seat wall 2c in the tool radial direction. Can be moved to.

  As shown in FIG. 2, the adjusting screw 11 includes a small-diameter portion 11 a having an outer diameter smaller than the inner diameter of the shaft hole 10 a provided in the wedge 10, and a screw portion 11 b screwed into the screw hole 2 e provided in the tool body 2. And a contact surface 11 c that contacts the back surface of the wedge 10. A male screw is formed on the outer periphery of the screw portion 11b.

  The contact surface 11c is a surface formed by a step surface formed at the boundary between the small diameter portion 11a and the screw portion 11b having a larger diameter than the small diameter portion.

  The small diameter portion 11a is loosely fitted in the shaft hole 10a. There is an appropriate play (gap) between the inner diameter of the shaft hole 10a and the outer diameter of the small diameter portion 11a, and the reaction force when machining the workpiece is all transmitted to the tool body 2 by the play.

  The reaction force is transmitted to the seat wall 2c of the tool body via the wedge 10, and the reaction force is received by the tool body 2. Therefore, no reaction force is transmitted to the adjusting screw 11. Thereby, the contact area of the wedge 10 with respect to the seat wall 2c is ensured widely, and the position holding | maintenance of the blade edge | tip of the cutting insert 3 is stabilized.

  The length L1 of the small-diameter portion 11a shown in FIG. 2 of the adjusting screw 11 is longer than the amount L that the wedge 10 can advance to the maximum from the reverse end point with the cartridge 5 removed.

  Here, the backward end point of the wedge 10 is a position where the tapered surface of the tip of the wedge 10 comes into contact with the receiving surface 5c of the cartridge 5 when the cartridge 5 is at the movement end point inside the tool radial direction.

  The distance that the wedge 10 can move in the front-rear direction with the adjustment screw 11 removed is larger than the length L1 of the small-diameter portion 11a. Thereby, it is possible to insert the small diameter portion 11a of the adjusting screw into the shaft hole 10a.

  As described above, when the condition of L1> L is satisfied with respect to the relationship between the length L1 of the small diameter portion of the adjusting screw 11 and the maximum advanceable amount L from the backward end point of the wedge 10, the cartridge 5 is inserted into the cutting insert. The wedge 10 does not fall when removed from the tool body 2 for the purpose of replacement.

  The blade edge position adjusting mechanism 8 for adjusting the blade edge position of the cutting insert 4 has an adjustment screw 12 screwed to the rear end of the cartridge 6 and a rotation operation portion (the locking hole of the bar wrench in the figure) is provided on the outer periphery of the head. The top surface of the adjusting screw 12 is brought into contact with the wall surface at the back end of the guide groove 2b, and the screwing amount of the adjusting screw 12 into the cartridge 6 is changed, so that the tool radial direction position of the cartridge 6 is determined with reference to the wall surface at the back end. This is a well-known mechanism for changing.

  In the blade edge position adjusting mechanism 8, the adjusting screw 12 receives a reaction force when a workpiece is processed by a tool. However, the reaction force in this case acts on the adjusting screw 12 in the axial direction, not in the direction perpendicular to the axis. Therefore, the deflection of the adjusting screw 12 due to the reaction force can be ignored, and the position holding of the cutting insert 4 is stabilized.

  In the illustrated cutting tool, the two cartridges 5 and 6 are arranged with the mounting direction shifted by 70 ° to 120 ° in the tool circumferential direction. As can be seen from FIG. 4, the cartridge 6 is disposed at a position retracted in the axial direction of the tool from the cartridge 5, and there is no back metal portion of the tool body behind the cartridge 5.

  Due to such a structure, a mechanism similar to the blade edge position adjusting mechanism 8 cannot be used for the cartridge 5. The blade edge position adjusting mechanism 7 described above enables stable holding of the blade edge position without transmitting a reaction force to the adjustment screw even with such a structure.

  In the illustrated cutting tool, different types of blade edge position adjusting mechanisms attached to the two cartridges 5 and 6 are provided, but at least one cartridge is an adjustment mechanism similar to the illustrated blade edge position adjusting mechanism 7. If it is.

  Further, if there is no installation restriction in terms of space, an adjustment mechanism similar to the exemplified blade edge position adjustment mechanism 7 can be attached to the two cartridges.

DESCRIPTION OF SYMBOLS 1 Cutting tool 2 Tool main body 2a, 2b Guide groove 2c Seat wall 2d Groove wall 2e Screw hole 3,4 Cutting insert 5,6 Cartridge 5a Bolt hole 5b Seat hole 5c Receiving surface 7,8 Cutting edge position adjusting mechanism 9 Clamp bolt 10 Wedge 10a Shaft hole 11 Adjustment screw 11a Small diameter part 11b Screw part 11c Contact surface 12 Adjustment screw

Claims (4)

A tool body, a cartridge having a cutting insert attached to the front end and a receiving surface formed at the rear end, and a blade edge position adjusting mechanism for changing the position of the cartridge;
The cartridge is installed on the bottom surface of the tool body;
The blade edge position adjusting mechanism is disposed between the receiving surface of the cartridge and a seat wall formed on the tool body so as to be movable along the bottom surface of the tool body while contacting the receiving surface and the seat wall. It is configured by combining a wedge and an adjusting screw that displaces the wedge,
The adjustment screw has a male screw formed on a small diameter portion whose outer diameter is loosely fitted in a shaft hole provided in the wedge and smaller than an inner diameter of the shaft hole, and on an outer periphery screwed into a screw hole provided in the tool body. A cutting tool having a threaded portion having a larger diameter than the small-diametered portion, and a contact surface in contact with the wedge.   The length of the small-diameter portion of the adjustment screw is longer than the maximum advanceable amount when the cartridge is removed from the position where the wedge comes into contact with the receiving surface of the cartridge at the end of movement in the tool radial direction. Item 2. The cutting tool according to Item 1.   3. The cartridge according to claim 1, wherein two cartridges are installed on the bottom surface of the tool body, and the two cartridges are arranged with a mounting direction shifted by 70 ° to 120 ° in the tool circumferential direction. Cutting tools.   One of the two cartridges is disposed at a position retracted in the axial direction of the tool relative to the other one cartridge, and there is no back metal portion of the tool body behind the other one cartridge. The cutting tool according to any one of claims 1 to 3, wherein a blade edge position adjusting mechanism in which the wedge and the adjusting screw are combined is attached to one cartridge.

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