JP2005144572A - Tool and method for machining workpiece - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a tool and a cutting insert, and a method for installing the cutting insert, performable even by a not so much skilled person, and easy in replacing the tool, without deteriorating a machining or work quality. <P>SOLUTION: A machining tool of a workpiece is arranged in a universal device for automatically machining the small workpiece by various lathe machining works. The cutting insert 13 is fixed in a tool holder 14 by a fixing screw 19. The cutting insert 13 is constituted as a reversible plate, and has two conical shape receiving parts for a conical grip head 25 of the fixing screw 19. This reversible plate has several possible uses such as grooving, a plunge, a turn, threading, a front turn, a back turn and separation. A central opening 30 of the cutting insert is connected to a narrow trapezoidal surface 35 of the cutting insert by a slot 36, and the slot 36 has a sufficient width fittable to a shank of the fixing screw 19. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a tool for machining, in particular to a tool for machining a workpiece with a universal device by lathe machining.

  The tool comprises a tool holder with a shank portion and a fixing member having a thicker grip head and a cutting insert fixed to it, the cutting insert being fixed with at least one blade, usually two blades An opening for the member and at least one grip surface cooperating with the grip head. The tool holder has a grip device for a fixing member.

  Such a tool is known from German Patent 36 32 296A and German Patent 42 14 355A. In the case of the tool of DE 42 14 355A, the fixing member comprises a clamping screw, which projects through a round hole with a conical land of a triangular or trapezoidal cutting insert.

In particular, in the case of universal or automatic devices that process very small precision workpieces, such as clocks and watch spindles, both the cutting insert and the tool holder are very small. Such universal devices have a linear or turret-like tool changer in which the tools are housed in close proximity and juxtaposed, such devices are usually operated continuously in three turns and are skilled. Only the operator who has done so will monitor automated work otherwise, so a problem arises if the tool has to be replaced due to tool breakage or the like. In this case, it is usually necessary to wait for a setter for replacing the tool, that is, a maintenance manager.
German Patent 36 32 296A German patent 42 14 355A

  Therefore, since the object of the present invention can be performed by a less skilled person without reducing machining or work quality, the manufacture of tools and cutting inserts, and cutting inserts that are easy to change tools It is to provide a method of wearing.

  The present invention provides a cutting insert having a slot that connects an opening to the outer edge of the cutting insert, and the tool includes the cutting insert having a width equal to or greater than the thickness of the shank portion of the fixing member. To solve.

  In this way, the cutting insert can be removed in the longitudinal direction of the tool holder after loosening the fixing member, i.e. in most cases the fixing screw is completely separated from the tool holder or unscrewed. Can be extracted in a direction perpendicular to the direction, i.e. normally upward. This is an important advantage, especially for tool holders that are small and difficult to access. Conveniently, the securing member can be placed on the tool holder so that it does not fall into the trash bin and is usually not recovered from the trash bin. Can not. This solution can also select fixing members other than screws, such as cam / clamp fixtures.

  A further important advantage is obtained if the fixing member can be operated from the side of the tool holder opposite to the cutting insert, preferably from both sides, for the purpose of tightening and loosening. Therefore, in particular, for example, the internal grip surface (hexagonal recess, hexagonal socket head, etc.) is provided in the screw shank, so that the cutting insert can be loosened from the rear side. On the side where the cutting insert is fixed to the tool holder, access is normally prevented by the device chuck, so that these internal key surfaces allow the corresponding tool to be actuated from the rear side.

  The grip head and the corresponding grip surface can be substantially conical. Since the slot width is preferably smaller than the lateral dimension of the grip head, the cutting insert is self-aligned when the fixing member is tightened even if there is a slot.

  The cutting insert preferably has at least one leg defining a gap, the leg being inclined towards the gap. If the cutting insert has a symmetrical structure, the two legs defining the gap provide a wedge-shaped orientation surface, which cooperates with the corresponding inclined surface of the tool holder so that the accuracy of the cutting insert relative to the tool holder can be reduced. Orientation is performed. This structure can also prevent the two fork-shaped legs from having a tendency to expand despite large gaps acting on the cutting insert, despite the gap. They are held together by corresponding stop surfaces on the holder in the same way as clips or clamps. The cutting insert is preferably in the form of a reversible or flip plate and correspondingly has two facing blades that can be used by reversing the cutting insert on the tool holder. Thus, the cutting insert has corresponding conical surfaces on both sides of the opening.

  In order to ensure that the cutting insert is pressed pre-tensioned onto the corresponding stop surface of the tool holder, the center axis of the fixing member and the corresponding axis of the opening or grip surface provided on it are separated from the stop or orientation surface. The distance or the distance is determined such that the cutting insert can generate a force acting in the direction of the stop surface when the fixing member is tightened. For this reason, the distance from the stop surface to the grip head central axis is somewhat smaller than the distance between the central axis of the corresponding grip surface and the orientation surface. However, these are only a fraction of a millimeter, but still ensure that automatic clamping can be performed.

  The present invention also provides a cutting insert for a tool for machining, which has a slot connecting an opening to an outer edge portion of the cutting insert, and the slot width is equal to or greater than the width of the shank portion. It is preferably triangular and has a generally central opening and a slot in one corner, preferably a blade in the remaining two corners.

  The method provided by the present invention for fixing or removing a cutting insert with respect to a tool holder is perpendicular to its extending direction with respect to the shank portion of the fixing member when the fixing member is in a relaxed position. In the direction, the cutting insert can be fitted or removed. The fixing member can be moved between the loosening and tightening positions by a screwing action, and the loosening position can reliably prevent further loosening in order to keep the fixing member in a tethered state.

  The above and further features can be inferred from the claims, the detailed description and the drawings, and individual features can be implemented in embodiments and other fields of the invention, both alone and in several combinations. Which can represent a convenient and independently protectable structure claiming protection here. Dividing an application into individual parts and subheadings in no way limits the overall effectiveness of the description based thereon.

  The present invention will now be described in more detail with reference to the accompanying drawings.

  1 to 4 show the tool 11 in a greatly enlarged form. It is intended to be used in universal equipment or automatic lathes that attempt to finish small, usually precision machine parts in a single setting. This includes inner and outer turning, grooving, threading and other operations, and finally detaching the workpiece from the rod guided by the automatic chuck. All of these operations are performed in an automatically controlled manner by the device, so that the device operates completely automatically. For this purpose, the device has a complete register of various cutting tools which can be provided in the form of a displaceable linear register or as a turret head. Each of these tools includes a blade having a special profile that can be engaged with the workpiece in a machined state. Depending on the planned device type, these tools are also known as “Swiss Tools”.

  The tool 11 includes a tool holder 12 and a cutting insert 13. Although the tool holder is made of steel, a hole is formed in the shank 14 for fastening to the apparatus, and a hard metal bar 15 is fitted in the hole. As described in German Patent No. 42 14 355A above, the metal bar 15 serves as an anti-vibration, which can be attributed to its material structure and in particular the high elastic modulus of hard metal. .

  A recess 16 is provided at the opposite end of the tool holder to form a receiving part for the cutting insert 13. Two stop surfaces 17 are formed in the recess, and these are inclined so as to open toward the center of the recess. A fixing member 19 in the form of a screw, having a shaft 18 perpendicular to the tool holder, protrudes therethrough and is screwed into the thread 20 of the tool holder.

  The tool holder is provided with a projecting portion 21 projecting sideways in the region carrying the cutting insert, and a screw shank 22 is fitted in the tightened state (FIG. 4) in its deep recess 23.

  The fixing member 19 has a grip head 24 with a conical grip head surface 25 and an internal key surface 26 for a tightening key 27. The key surface can be configured like a hex recess or hex socket head grip surface. The grip head is somewhat contracted towards the shank, but its outer diameter is larger than the screw shank including the provided threads.

  When the circlip 28 is inserted into the groove at the end of the screw shank 22 and the fixing member 19 is in the loosened position shown in FIG. 3, the circlip abuts the bottom surface 29 of the recess 23, thereby The member is fixed so that it does not come off the screw thread 20 completely.

  The cutting insert 13 is in the form of a relatively thick trapezoidal small hard metal plate. An opening 30 is provided at the center thereof, and passes through a circular shape centering on a central axis 31. Each of the openings has a conical recess symmetrically toward both sides 32 of the cutting insert, resulting in the formation of a grip surface 33, which has an angle and diameter that matches the grip head surface 25 of the fixing member. It is configured to have. A narrow cylindrical opening 34 is provided between the two conical grip surfaces 33.

  A slot 36 extends from the short trapezoidal surface 35 of the cutting insert to the opening, the width of which is dimensioned to fit over the screw shank. Its diameter is only slightly wider than the screw shank, i.e. 2 / 10-3 / 10 to 1-2 millimeters. However, it is narrower than the outer diameter of the grip surface 33 to the extent that it cooperates with the grip head 24. Thus, it can be centered with the conical grip surface in the clamped state and not pulled into the slot.

  The cutting insert forms a triangular yoke, the legs 37 on either side of its opening having an orienting surface 38 on the outer surface, the angle and dimensions of which coincide with the stop surface 17.

  The two outer edges of the trapezoidal yoke form a cutting insert blade 39, which is cut or contoured according to the intended application. As a result of the completely symmetrical structure, the cutting insert can be used as a small reversible plate, whereby one of the two blades 39 can be engaged with the workpiece 40 in each case.

  The recess 16 in the tool holder has an inner stop surface 41 with which the cutting insert 13 engages.

  FIG. 5 shows a tool 11 configured for a cutting insert 13 having a relatively long and thin blade 39, which is suitable, for example, for cutting off large diameter tool pieces. This cutting insert has only one blade and is therefore not reversed. Otherwise, it has all the features of the tool, but the orientation and structure of the stop surfaces 38, 17 is somewhat different. The fixing member 19 is shown in cross section.

  6-9 clearly show the structure of the cutting insert according to the invention. Refer to these drawings for the exact structure. It will be appreciated that the cutting insert is small and compact, but very stable. The grip and the fixing surface are very large compared to the moment arm on which the size and cutting force act, and are close to the blade. It is easy to manufacture it from a hard metal sintered profile or sintered part and only requires machining by cutting. This is very advantageous compared to a conventional cutting insert with two screws. In that case, besides the mounting disadvantages, the cutting insert is relatively long and not very stable and therefore prone to vibration.

  FIGS. 10 and 11 show the tool 11 provided with the tool holder 12 and the cutting insert 13 in a plan view substantially similar to FIG. Between the grip head 24 of the fixing member 19 and the corresponding conical grip surface 33, a conical annular disc 50 is arranged whose shape and width are on the grip head surface and thus the corresponding grip of the cutting insert 13. Note that the surface 33 is also adapted. It acts as a washer and protects the grip head surface 25 from being damaged by the edge of the slot 36 interrupting the grip surface 33. It is in a loose fit and can be pulled away with the grip head 24, as shown in FIG. 11, so that the cutting insert can be removed upwards.

  In the embodiment of the fixing member 19 (cap screw) and the tightening key 37 shown in FIGS. 10 and 11, it is not necessary to provide the circlip 28 having the shape shown in FIG. 3 on the screw shank 22. The tightening key contour portions 42, 43 have a hexagon socket head contour on the side corresponding to the inner key surface 44 in the screw shank 22, and form a stop 51 at a predetermined distance a from the end of the contour portion 43. The disc is fixed and is large enough to abut the back 48 of the tool holder 12 when the screw 19 is loosened. Instead of being in the form of a ring attached to the clamping key 27, the stop 51 may be formed by a sleeve or a corresponding thickened part of the clamping key shank, which is a distance a from the end of the key surface 43. it can.

  The method of attaching and detaching the cutting insert 13 with respect to the tool holder can be seen from FIGS.

  The fixing member is operated by the tightening key 27. As can be seen from FIG. 3, the clamping key 27 has a hexagon socket head-shaped contour portion 42 on one side, which coincides with the large internal key surface 26 in the grip head 24 and also its L-shaped bent shank. On the other side is a key surface 43 of the same type, but with a small diameter, which coincides with the internal key surface 44 of the end face 45 of the screw shank 22.

  FIG. 3 shows the fixing member 19 in the relaxed position, in which case the grip head 24 protrudes from the opening 30 and the grip surfaces 25, 33 are not in mutual engagement. The fixing member 19 is loosened from the tool holder 14 until the circlip 28 abuts the bottom surface 29, thus preventing loss of screws.

  As shown in FIG. 2, the cutting insert can be extracted upwards at this position, ie in a direction perpendicular to the longitudinal direction of the tool holder 14, so that it can be replaced by another screw, After rotating 180 °, the opposite blade 39 can be reinserted for use.

  Following insertion, the fixation member is returned to the gripping or clamping position by screwing (in view of the grip head), as shown in FIGS. In this position, the grip surface 32 engages the grip head surface 25 and presses one side 32 of the cutting insert against the stop surface 41. As a result of the conical gripping surface 33, the cutting insert is self-aligned and is assisted by the axial displacement between the fixing member and the shafts 18 and 31 of the opening and pressed against the stop surface 17 at the orientation surface 38. Accordingly, the cutting insert is fixed to the tool holder in the lateral direction as well as in the longitudinal position and orientation.

  Because the wedge-shaped orientation surface 38 is gripped or clamped in the corresponding wedge-shaped receptacle of the stop surface 17, the force applied by the grip head 24 and acting on the leg 37 does not cause the slot 36 to expand. Can be. Thus, the corresponding precisely cut cutting insert can be reversed or replaced with another corresponding cutting insert without compromising the exact alignment of the blade with respect to the workpiece 40. Therefore, an inexperienced person can replace the cutting insert without the need for measurement or set-up work, and in particular without having to disassemble the tool holder 14 from the apparatus. This is made possible in particular by allowing the clamping key 27 to be inserted into the key surface 44 so that it can be moved closer to the fixing member 19 from the back side 48 of the tool holder opposite the grip head and the cutting insert 13.

  10 and 11 show a tool in which a tightening key can be applied from both sides. In practice, it is used only from one side. In FIG. 10, a conical annular disk 50 is disposed between the grip surface 33 and the grip head surface 25, so that the grip head surface 25 is seized against the edge 52 of the cutting insert 13 (see FIGS. 6 and 8) or It has been shown to protect against damage from certain cutting effects. The fixing member 19 is completely loosened by the tightening key and its hexagon socket head profile portion 42 that fits into the grip head so that the annular disk can be replaced quickly.

  As described above, in practice, the fixing member 19 is always screwed to a position lowered from the tool holder back surface 48. For this purpose, the distance a between the stop surface 51 and the end of the tightening key contour portion 43 is dimensioned to be shorter than the thread 20 in the tool holder 12. Thus, as shown in FIG. 10, the clamping key 27 engages the corresponding internal key surface 44 to rotate the fixation screw 19 between the clamping position (FIG. 10) and the release position (FIG. 11). be able to. However, since the stop 51 contacts the tool holder back surface 48 before the fixing screw 19 is completely removed from the thread 20, the clamping key 27 is pulled away from the grip surface contour 44 in the screw shank 22, so that the screw Is not loosened any further and therefore cannot fall out of the thread 20. Thereby, the loss of the fixing member 19 can be automatically prevented.

1 is a side view of a tool according to the present invention with a cutting insert in a fixed state. FIG. FIG. 6 is a similar side view with the cutting insert removed from the tool holder. It is a detailed sectional view of the tool holder in a state where the cutting insert is fitted but not tightened. FIG. 4 is a view similar to FIG. 3 with the cutting insert in a tightened state. It is a figure which shows the tool holder provided with the single-sided cutting insert which has the braid | blade which protruded largely. It is a perspective view of a cutting insert. It is a top view of the cutting insert of FIG. It is a side view of the cutting insert of FIG. It is a front view of the blade of the cutting insert of FIG. It is a top view shown with a partial section of a tool in which a cutting insert is in a tightening state. It is a top view shown in the partial cross section of the tool in which the cutting insert is in the tightening release state.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Tool 12 Tool holder 13 Cutting insert 14 Shank 15 Metal bar 16 Recess 17 Stop surface 19 Fixing member 20 Thread 21 Projection part 22 Screw shank 24 Grip head 25 Conical grip head surface 26 Internal key surface 28 Circlip 31 Central axis 33 Conical grip surface 36 Slot 39 Blade 40 Work piece 48 Tool holder back 50 Conical annular disk 51 Stop surface

Claims (8)

In a tool for machining, for example a tool for machining a workpiece (40) with a universal device, in particular by lathe machining,
a) a tool holder (12) with a fixing member (19) having a shank portion (22) and a thicker grip head (24);
b) a cutting insert (13) fixed thereto;
c) the cutting insert comprises at least one blade (39);
d) an opening (30) for the fixing member (19);
e) having at least one grip surface (33) cooperating with the grip head (24);
f) The tool holder (12) is a machining tool having tension means for the fixing member (19),
g) the cutting insert has a slot (36) connecting the opening (30) to an outer edge (35) of the cutting insert (13);
h) A tool characterized in that the slot has a width equal to or greater than the thickness of the shank portion (22).   The fixing member (19) can be operated from the back (48) of the tool holder (12) opposite the cutting insert (13) and preferably from both sides for the purpose of tightening and loosening. The tool according to claim 1, characterized in that:   The tool according to claim 1 or 2, wherein the cutting insert is configured as a reversible plate, and in particular grip surfaces are provided on both sides of the opening.   Tool according to any one of the preceding claims, characterized in that the fixing member (19) is preferably a screw provided with internal key surfaces (26, 44) on both end faces.   The cutting insert (13) has at least one orientation surface (38), and the tool holder (12) has at least one stop surface (17) cooperating with the orientation surface (38). And, in particular, on both sides of said slot (36), preferably outside the opening (30), is provided with an orientation surface (38) defining a leg (37), the spacing of which is A tool according to any one of the preceding claims, characterized in that it decreases with increasing distance from (30).   It is especially for tools that machine the workpiece (40) with a universal device by lathe machining, and is fixed to the tool holder (12) by a fixing member (19) comprising a shank portion (22) and a grip head (24). And a cutting insert having at least one blade (39), an opening (30) for the fixing member (19), and a grip surface (33) for the grip head (24), wherein the opening A cutting insert having a slot (36) connecting (30) to an outer edge (35) of the cutting insert (13), the slot having a width equal to or greater than the width of the shank portion (22). .   Triangular and has a substantially central opening (30) and a slot (36) provided in one corner, preferably a blade (39) in the other two corners. The cutting insert according to claim 6. In a method for fixing or removing a cutting insert (13) provided with an opening (30) with respect to a tool holder (12), fixing with a shank part (22) and a grip head (24) thicker than the shank part The member (19) can move between a loosening position and a gripping position, and when the fixing member (19) is in the loosening position, the shank portion ( 22), characterized in that the cutting insert (13) can be fitted or removed in a direction perpendicular to its extending direction.

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