JP5040032B2 - Cutting tool holder and replaceable cutting tool using it - Google Patents

Description

  The present invention relates to a blade holder that has been devised in a clamp structure of a blade tip replaceable tip to be mounted on a tip seat and a blade tip replaceable bite using the same.

  As a conventional example of the above-mentioned blade holder, there is one described in Patent Document 1 below. The blade holder disclosed in Patent Document 1 includes a presser to be fastened with a tightening bolt, a protrusion that engages with a mounting hole at the center of a blade-tip-exchangeable cutting blade tip (hereinafter simply referred to as a tip), and an upper surface of the tip. A pressing surface that is pressed against the surface of the holder body at both ends in the width direction of the presser foot, and the chip is pressed against the seat bottom of the chip seat by the pressing surface, and at the same time, A pulling force is generated in the presser foot by a sliding action, and the tip is pressed against the seat side surface of the tip seat by the force.

The pressing surface formed on the presser foot is flat, and the flat portion on the upper surface of the chip is pressed by the flat pressing surface.
JP 2000-246514 A

  As described above, pressing for clamping the chip with the presser is performed by pressing the flat pressing surface of the presser against the upper surface of the chip. Therefore, a flat part is usually formed on the upper surface of the chip. A chip provided with a chip breaker on the upper surface also has a land portion at the center of the upper surface to flatten the upper surface of the land portion. With such a chip, even the blade holder disclosed in Patent Document 1 can be clamped stably.

  However, recently, with the diversification of chip breakers, a chip as shown in FIG. 7 has been developed, and a blade holder that can clamp the chip stably has been required. The chip 20 of FIG. 7 does not have a land portion at the center of the upper surface, and a breaker groove 21 having a curved groove surface curved in a three-dimensional direction is formed on the upper surface to reach the position of the center mounting hole 22.

  When trying to clamp such a tip with a presser foot provided on a conventional blade holder, the curved groove surface will be pressed with the flat pressing surface of the presser foot, and the groove surface at that time will be pressed. The contact of the presser foot becomes unstable and a stable clamp cannot be expected.

  A sintered body is often used as a tip as a cutting tool of a cutting tool. The chip of the sintered body is cheaper with the sintered skin left, but the one with the sintered skin is inferior in dimensional accuracy compared to the polished chip, so the upper surface is curved. In particular, the presser foot is likely to come into contact with each other, and such a tip is liable to deteriorate the stability of the clamp.

  In the blade holder disclosed in the above-mentioned Patent Document 1, since the two sliding surfaces provided at both ends in the width direction of the rear portion of the presser foot are brought into contact with and restrained by the inclined surface provided in the holder body, the inclined surface on the holder body side A force (a force that prevents the presser foot from changing its posture) to maintain the contact state of the two sliding surfaces with respect to is strongly exerted. For this reason, even if the pressing surface comes into contact with one piece, the function of correcting the pressing surface is not exhibited, and it is inevitable that the clamp becomes unstable depending on the shape and accuracy of the upper surface of the chip.

  The present invention eliminates the above problems, that is, a chip in which a portion pressed by a presser foot (hereinafter referred to as a pressed portion) is a curved surface, a chip whose flatness of the pressed portion is low, and the like The problem is to enable stable and reliable clamping.

In order to solve the above-described problems, in the present invention, a blade holder as disclosed in Patent Document 1, specifically, a blade-tip replaceable tip having a mounting hole is seated on a tip seat of the holder body. The blade tip replaceable tip is pressed with a presser foot that is fastened to a tightening bolt, and a convex portion provided at the tip of the presser foot is locked inside the mounting hole, and a slope provided on the upper surface of the holder body In the blade holder for bringing the sliding surface provided on the lower surface of the presser foot into contact with the blade and pulling the blade-tip replaceable tip against the seat side surface of the tip seat by the sliding action of the sliding surface on the slope,
The tip pressing portion of the presser foot is composed of two hemispherical protrusions, the inclined surface is formed in a V shape in a view as seen in the sliding direction of the sliding surface, and the sliding surface is a spherical surface of the hemispherical protrusion. The spherical sliding surface was made to contact the V-shaped slope at two points.

  In the blade holder, the convex portion and the sliding surface are arranged on the center line of the presser foot in a plan view, and the two hemispherical protrusions constituting the tip pressing portion are symmetrical with respect to the center line. Those arranged are preferred.

  A blade-tip replaceable tip is attached to the tip seat of the blade holder, and the upper surface of the blade-tip replaceable tip is pressed by a tip pressing portion comprising two hemispherical protrusions provided on a presser foot of the blade holder. And fix to the blade holder. The present invention also provides a blade-replaceable tool configured as described above.

  This cutting edge-replaceable tool is particularly effective when using a blade-replaceable tip having a curved pressed portion, but it is also effective when the pressed portion clamps a flat tip. Demonstrated.

Since the cutting tool holder of this invention comprises the tip pressing portion of the presser foot with two hemispherical protrusions,
Even if the pressed portion on the upper surface of the chip is curved or the flatness of the pressed portion is poor, the two hemispherical projections come into contact with the pressed portion and the presser piece is prevented from being hit by one piece.

  Even if the upper surface of the chip swells or warps between the two hemispherical protrusions, the protrusions contact the pressed part across the bulging part or the warping part. Also, when the height position of the pressed part on the tip side where the two hemispherical projections are in contact is uneven, the presser foot is tilted so that the two hemispherical projections are placed on the top surface of the chip at two points. Contact. By making the sliding surface of the lower surface of the presser foot into a spherical surface with a hemispherical protrusion, the presser foot is easy to roll, and if there is a difference in height as described above, it tilts to the point where the height difference is absorbed . As a result, the two hemispherical protrusions reliably come into contact with the upper surface of the chip at two points, and the two locations on the upper surface of the chip are evenly pressed, and the stability of the clamp is increased.

  In addition, since the inclined surface provided in the holder body is formed in a V shape, and the spherical sliding surface is brought into contact with the inclined surface formed in the V shape at two points, the presser foot may rattle in the width direction. There is no chip clamp with high position accuracy.

  When a presser foot is used in which the convex part at the front end and the sliding surface at the rear part are arranged on the center line in plan view, and two hemispherical protrusions constituting the chip pressing part are arranged symmetrically with respect to the center line. The clamping force can be applied to the tip in a well-balanced manner.

  Hereinafter, based on FIGS. 1-6 of an accompanying drawing, embodiment of the blade holder of this invention and a blade-tip-exchange-type cutting tool using the same is described.

  1 and 2 includes a holder body (shank) 2, a presser foot 3, a tightening bolt 4 for tightening the presser foot 3, and a spring 5 for pushing up the presser foot 3 during unclamping. Has been. When a tip (blade tip replaceable tip) 20 is attached to the blade holder 1, the blade tip replaceable cutting tool 30 shown in the figure is obtained.

  A tip seat 6 having a seat bottom 6 a and seat side surfaces 6 b and 6 b having different directions is provided at the tip of the upper surface of the holder body 2. The seat bottom 6a of the chip seat 6 is constituted by a floor plate 8 fixed to the holder body 2 with a mounting screw 7, and it is possible to regenerate a damaged seat bottom by replacing the floor plate. It is only a preferable element.

  On the upper surface of the holder body 2, a slope 9 (see FIGS. 2 and 3) is provided at a position keeping a predetermined distance from the chip seat 6 and inclined in a direction in which the side away from the chip seat 6 is downward. The inclined surface 9 is centered on a corner bisector C1 of a corner angle formed by the intersection of the two seating side surfaces 6b, 6b of the chip seat 6, and the sliding direction of the sliding surface 13 described later (FIG. 2). It is formed in a V shape in a view seen in the direction of arrow A (see FIG. 4).

  As shown in FIGS. 1, 2, and 6, the presser foot 3 has a hanging convex portion 10 at the lower end of the tip, and further has a chip pressing portion 11 on the lower surface behind the convex portion 10. Moreover, it has a bolt hole 12 with a long hole near the middle in the longitudinal direction, and has a sliding surface 13 protruding downward on the lower surface of the rear part.

  The convex part 10, the bolt hole 12 with a seat, and the sliding surface 13 are arrange | positioned on the centerline C2 of the presser foot 3 by planar view of FIG. Further, the tip pressing portion 11 is constituted by two hemispherical protrusions arranged symmetrically with respect to the center line C2 of the presser foot 3, and the sliding surface 13 brought into contact with the inclined surface 9 is a spherical surface of the hemispherical protrusion. It consists of

  The tightening bolt 4 is inserted into a bolt hole 12 with a presser foot seat and screwed into a screw hole 14 provided in the holder body 2. The spring 5 is fitted on the outer periphery of the fastening bolt 4 and is contracted between the lower surface of the presser foot 3 and the holder body 2.

  The chip 20 has been described with reference to FIG. 7 and has a breaker groove 21 on the upper surface and a mounting hole 22 in the center of the upper surface. The illustrated chip 20 has a square shape in plan view, and is provided with breaker grooves 21 in which the central portion between the corners is recessed most in the side view between the four corner portions. The breaker groove 21 has a curved groove surface curved in a three-dimensional direction, and the curved groove surface extends from a portion along a straight side that becomes a cutting edge of the chip to an installation portion of the mounting hole 22. Has reached.

  The tip 20 is seated on the tip seat 6 of the holder body 2 as shown in FIGS. 1 and 2, and the convex portion 10 of the tip of the presser foot 3 enters the mounting hole 22 and engages with the hole surface. . In this state, the clamping bolt 4 is tightened, and the curved groove surface of the breaker groove 21 formed on the upper surface of the chip 20 is pressed by the chip pressing portion 11 on the lower surface of the presser foot 3 constituted by two hemispherical protrusions. To do.

  FIG. 5 shows a pressing state at a position along the line YY in FIG. The groove surfaces of the adjacent breaker grooves 21 and 21 intersect with each other to form a ridge line 23 at a position overlapping the diagonal line on the upper surface of the chip. Therefore, when this portion is pressed with a presser having a flat chip pressing surface, The pressing surface comes into point contact with the portion of the ridge line 23, and stable clamping is not performed.

  On the other hand, in the presser foot 3 employed in the blade holder of the present invention, the tip pressing portion 11 is constituted by two hemispherical protrusions, so that the tip pressing portion 11 reliably contacts the tip 20 at two points. The pressing force acts equally on the two contact points. The contact at two points of the chip pressing part 11 at this time is 2 with a difference in height assuming that the height positions of the two pressed parts on the upper surface of the chip 20 are uneven in FIG. This is done by tilting the presser foot 3 to the point where the two hemispherical projections come into contact with the pressed part at the location. This inclination (rolling) is allowed by configuring the rear sliding surface 13 of the presser foot with a spherical surface of a hemispherical protrusion, so that even when the flatness of the pressed portion is poor, Reliable contact of the hemispherical protrusion with the pressed portion is ensured.

  Further, since the slope 9 on the holder main body side that supports the sliding surface 13 is formed in a V shape, the sliding surface 13 comes into contact with the inclined surface 9 at two points as shown in FIG. Shaking is prevented.

  Further, the sliding surface 13 slides down on the slope 9 as the tightening bolt 4 is tightened, whereby the presser foot 3 is pulled to the right in FIG. 2 (between the seated bolt hole 12 and the tightening bolt 4). 2), two adjacent side surfaces of the chip 20 are pressed against the seat side surfaces 6b and 6b of the chip seat 6. These functions effectively, and the chip 20 is firmly and stably clamped.

  The present invention can also be applied to a planer shape other than a square, for example, a blade holder or a blade-tip-exchangeable tool using a tip such as a triangle or a diamond.

The top view which shows embodiment of the blade holder of this invention, and a blade-tip-exchange-type cutting tool Sectional view along XX in FIG. Plan view of the holder body of the blade holder in FIG. A view of the slope provided on the holder body as seen in the direction of arrow A in FIG. Sectional view along YY in FIG. (A) Top view of the presser foot, (b) Side view of the presser foot, (c) Side view of the presser foot, (d) Cross section of the presser foot, (e) Perspective view showing the bottom side (A) Top view which shows an example of the chip | tip hold | maintained with the blade holder of this invention, (b) The side view of a chip | tip same as the above.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cutting tool holder 2 Holder main body 3 Presser foot 4 Clamping bolt 5 Spring 6 Tip seat 6a Seat bottom 6b Seat side surface 7 Mounting screw 8 Base plate 9 Slope 10 Convex part 11 Tip press part 12 Seated bolt hole 13 Sliding surface 14 Screw hole 20 Cutting edge exchange Type chip 21 Breaker groove 22 Mounting hole 23 Ridge line 30 Cutting edge replaceable tool

Claims (4)

The blade tip replaceable tip (20) having the mounting hole (22) is seated on the tip seat (6) at the tip of the holder body (2), and the blade tip replaceable tip (20) is clamped to the tightening bolt (4). Pressed with the gold (3), and further, the convex portion (10) provided at the tip of the presser foot (3) was locked inside the mounting hole (22), and provided on the upper surface of the holder body (2). The sliding surface (13) provided on the lower surface of the presser foot (3) is brought into contact with the inclined surface (9), and the blade tip replaceable tip (20) is caused by the sliding action of the sliding surface (13) on the inclined surface (9). In a blade holder for clamping the tip seat (6) to the seat side surface (6b) and clamping it,
The tip pressing portion (11) of the presser foot (3) is composed of two hemispherical protrusions, and the slope (9) is formed in a V shape in a view seen in the sliding direction of the sliding surface (13). Further, the blade holder is characterized in that the sliding surface (13) is constituted by a spherical surface of a hemispherical projection, and the spherical sliding surface (13) is brought into contact with the V-shaped inclined surface (9) at two points. .   The convex portion (10) and the sliding surface (13) are arranged on the center line (C2) of the presser foot in a plan view, and two hemispherical protrusions constituting the tip pressing portion (11) are provided. The blade holder according to claim 1, wherein the blade holder is arranged symmetrically with respect to the center line (C2).   The blade tip replaceable tip (20) is mounted on the tip seat (6) of the tip of the blade holder (1) according to claim 1 or 2, and the upper surface of the blade tip replaceable tip (20) is attached to the presser foot ( A blade-tip-replaceable tool that is pressed to the blade holder (1) by being pressed by a tip pressing portion (11) comprising two hemispherical protrusions provided in 3).   A blade-tip replaceable tip (20) having a curved upper surface pressed portion is mounted on the tip seat (6), and the curved pressed portion is a tip pressing portion (11 comprising the two hemispherical projections). The cutting edge-exchangeable cutting tool according to claim 3, which is pressed in step).

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