JP4986477B2 - Clamp member and cutting tool holder comprising the same - Google Patents

Description

  The present invention relates to a clamp member used for mounting a cutting insert made of a hard material on a cutting tool holder body, and a cutting tool holder including the same.

  In recent years, a throw-away type cutting tool in which a cutting insert made of a hard material such as cemented carbide is detachably attached to a holder is frequently used. Cutting inserts and holders used for such cutting tools have various shapes as the cutting process is diversified. Along with this, various methods are used for the mounting method of mounting the cutting insert to the holder, so-called clamping method. Some are mounted with a single clamp member, such as a screw-on system, and some are mounted with a clamp member having a plurality of complex shapes, such as a wedge lock system. In any case, since the clamp member is a member used for mounting the cutting insert made of a hard material on the holder, the clamp member slides with the hard material, so that excellent wear resistance is required. As a result, the conventional clamp member is often made of a high-hardness material such as a cemented carbide member and a high-hardness steel member as the member that slides with the cutting insert. However, since the molding process of a high-hardness material such as cemented carbide often involves multiple processes, there are problems that the manufacturing cost is remarkably increased and it is difficult to mold a member having a complicated shape.

Therefore, as in Patent Document 1, carburizing and quenching is performed on the surface layer portion of the injection-molded product, and a hard layer having a higher hardness than the inside on the surface layer of a clamp member (corresponding to the chip holding member described in Patent Document 1) Thus, an inexpensive cutting tool is provided in which the necessary hardness and sufficient toughness are given to the clamp member.
Japanese Patent Laid-Open No. 5-16012

  However, although the clamp member used in the above-described cutting tool slides with a member having various hardnesses, a hard layer having higher hardness than the inside is formed on the entire surface layer of the clamp member. Therefore, rubbing wear is suppressed in the part where the clamp member slides with the cutting insert having a high hardness, but it is formed on the surface layer in the part where the clamp member slides with another member having a low hardness other than the cutting insert. Since the hardness difference between the hardness of the hard layer and the hardness of the other member that slides increases, the surface of the other member is likely to be rubbed and worn. Therefore, when trying to suppress this rubbing wear by increasing the hardness of other members, depending on the shape of the member, the toughness is insufficient and the chip tends to be lost.

  For example, a member that slides in a partially thinned part can be formed locally if the clamp member itself is made of a high-hardness material or a hard layer is formed on the entire surface of the member. Toughness is insufficient and cracks are easily generated from the toughness. Therefore, there is a limit to suppressing rubbing wear by increasing the hardness of other members. In particular, the holder is required to have a balanced strength and toughness from the functional aspect, and the hardness cannot be increased so much, so that the holder surface portion that slides with the clamp member in which the hard layer is formed on the entire surface layer has a large rubbing wear. Prone to occur. Such rubbing wear on the holder surface portion occurs not only at the time of cutting, but also only by repeatedly attaching and detaching the insert. As a result, in the conventional clamp member, both the clamp member and the other members such as the holder are worn out, so that both the members must be frequently replaced, resulting in a high cost. It was.

  The present invention has been made to solve such problems of the prior art, and in the clamp member used for mounting the cutting insert to the holder body, the wear resistance and toughness required as the clamp member are ensured. And it aims at providing the clamp member which can suppress rubbing wear not only in a sliding part with a cutting insert but in a sliding part with other members other than cutting inserts, such as a holder. .

In order to solve the above-mentioned problems, a clamp member according to the present invention is a clamp member for fixing a cutting insert to a cutting tool holder main body, and slides with different members on the surface portion of the clamp member. An external screw is engraved in the first sliding portion, and the first sliding portion is screwed with the cutting tool holder body. The second sliding portion slides with other members excluding the cutting tool holder main body, and a screw head is provided at the tip of the clamp member following the first sliding portion. The top surface is provided with a recess for fitting the clamp member into the holder main body by fitting and rotating the jig, and is farther from the first sliding portion than the screw head. The second sliding part provided at the position is subjected to quenching treatment. Accordingly, the surface hardness of the first sliding portion and the screw head, said with lower than the surface hardness of the second sliding portion, the surface hardness of the first sliding portion A, the cutting tool holder body When the surface hardness is B, 3/4 <A / B <1, and the surface hardness of the first and second sliding portions is 350 HV or more and 850 HV or less .

  With such a configuration, the surface of the clamp member is formed to have a different surface hardness at a portion that slides with another different member. Therefore, the clamp member has a surface hardness corresponding to the sliding member. be able to. Therefore, rubbing wear caused by sliding with different other members can be suppressed, and both the clamp member and the other members can have a long life, excellent clamping function and processing accuracy.

Furthermore, an external thread is engraved on the first sliding portion, and the second sliding portion slides with another member when the first sliding portion is screwed with another member. Thus, it is important because it is possible to suppress the rubbing wear of the second sliding portion and to suppress rubbing wear on the surface of other members on which the external screw slides.

The first sliding portion slides with the cutting tool holder body, and the surface hardness of the first sliding portion is lower than the surface hardness of the cutting tool holder. This is important because it can suppress rubbing wear on the surface of the cutting tool holder main body that slides with the first sliding portion and occurs at the time of replacing the insert, and can extend the life of the cutting tool holder main body.

Further, when the surface hardness of the first sliding portion is A and the surface hardness of the cutting tool holder main body is B, 3/4 <A / B <1 between the sliding members The difference in surface hardness at the sliding portion is reduced, and rubbing wear on the surface of the first sliding portion and the cutting tool holder main body sliding with the first sliding portion can be suppressed. This is important because both tool holder bodies can have a long life.

Further, the second sliding portion slides with other members excluding the holder body, and the surface of the second sliding portion is subjected to quenching treatment on the surface of the clamp member, Since the second sliding part that slides with other members excluding the holder main body such as a cutting insert having a high surface hardness, that is, particularly where wear resistance is required, is cured. This is important because the surface hardness of the second sliding portion is increased, and rubbing wear caused by sliding between the clamp member and other members excluding the holder main body can be suppressed.

In addition, it is partly hardened to the second sliding portion where excellent wear resistance is required even in the surface of the clamp member even in the complicated clamp member that the quenching treatment is performed by induction hardening. It is desirable because it can.

The surface hardness of the first and second sliding portions is 350 HV or more and 850 HV or less, not only the difference in surface hardness between the sliding members, but also the surface hardness of the sliding member itself. Is sufficiently obtained and wear resistance is improved, so that rubbing wear at each sliding portion can be suppressed, and both the clamp member and the other sliding member can have a long life, which is important .

  Furthermore, since the cutting tool holder of the present invention is a cutting tool holder having the above-described clamp member, rubbing wear caused by sliding of the clamp member and the cutting tool holder main body is suppressed, The clamp member and the cutting tool holder main body are desirable because they have a long life and excellent machining accuracy.

  According to the clamp member of the present invention, the surface portion has the first sliding portion and the second sliding portion that slide with different other members, respectively, and the surface hardness of the first sliding portion is the second sliding portion. Since the surface portion of the clamp member is formed to have a different surface hardness by configuring it to be lower than the surface hardness of the moving portion, depending on the surface hardness of another member that slides with the clamp member It can be the surface part of the clamp member. Therefore, rubbing wear can be suppressed at each sliding portion sliding with another different member, and the clamp member and the other member can have a long life and excellent surface accuracy.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  1 to 7 show an embodiment of the present invention. FIG. 1 shows a cutting tool 2 (hereinafter abbreviated as “insert”) by a clamping member 1 according to the first embodiment of the present invention. 1 is an overall perspective view of a turning tool mounted on a holder body 3 (hereinafter abbreviated as “holder body”), FIG. 2 is a plan view of the turning tool of FIG. 1, and FIG. (C) Long side side view, FIG. 3 is an AA cross-sectional view of FIG. 4 is an overall perspective view of a milling tool in which the cutting insert 2 is mounted on the cutting tool holder body 3 by the clamp member 1 according to the second embodiment of the present invention, and FIG. FIG. 6A is a cross-sectional view taken along line AA of FIG. 5B.

  1 and 2, the clamp member 1 according to the first embodiment is a member for mounting the insert 2 to the holder main body 3, and is used particularly for a turning tool. The holder 4 includes a set of clamp members including the clamp member 1 and a holder body 3, and a cutting tool in which the insert 2 is mounted on the holder 4 is fixed to a lathe or the like and used for cutting. The set of clamp members differs depending on the clamp method, and may be composed of members having a plurality of complicated shapes. In the present embodiment used in the lever lock system, the clamp member 1 is screwed into a holder screw hole 3A formed in the holder body 3 when the insert 2 is mounted on the holder body 3 as shown in FIG. It corresponds to the lock screw member 5 to be operated. Here, for such a lever lock method, other clamp members such as shim pins are also required, but for convenience, only a part of the clamp member set is illustrated, and hereinafter, the lock screw according to the present embodiment The member 5 will be described in detail.

  As shown in FIG. 3B, the lock screw member 5 has a substantially cylindrical shape, an external screw is engraved at one end, and a taper portion is provided at an intermediate portion. With such a shape, the lock screw member 5 is inserted into one end of the insert through hole 2A formed in the insert 2 and cooperates with the clamp lever member 6 installed in the holder main body 3 to move the insert 2 into the holder main body. 3 can be attached. That is, first, the other end of the L-shaped clamp lever member 6 is screwed by the taper portion of the lock screw member 5 by screwing one end of the lock screw member 5 in which the external screw is engraved into the holder screw hole 3A. Pressed. At this time, one end of the lock screw member 5 is screwed in, and the taper portion of the lock screw member 5 and the other end of the clamp lever member 6 slide so that the lock screw member 5 sinks into the holder main body 3. One end of each 6 moves so as to fall close to the lock screw member 5. As a result, one end of the clamp lever member 6 presses the insert 2 against the insert restraining surface of the holder body 3, and the insert 2 can be firmly attached to the holder body 3. The lever member used in such a lever lock system presses the chip, so if it has a simple shape as in this embodiment, a high-hardness material is used, such as steel hardened to high hardness. Often formed as a material. The clamp lever member 6 which is the lever member of the present embodiment is also exemplified by a material made of a high hardness material.

  On the other hand, the clamp member 1 of the present embodiment, that is, the lock screw member 5, has a first sliding portion 7 and a second sliding portion 8 that slide with different members on the surface portion, respectively. The surface hardness of the sliding portion 7 is formed to be lower than the surface hardness of the second sliding portion 8. Specifically, as shown in FIG. 3 (b), the first sliding portion 7 is formed in the portion where the external screw of the clamp member 1 (lock screw member 5) is engraved, and the second sliding is formed in the tapered portion. Part 8 is formed. By doing so, the surface part of the clamp member 1 can be comprised corresponding to the different surface hardness of the other member which the clamp member 1 slides. That is, of the different sliding members, the surface hardness of the first sliding portion 7 that slides with a member having a lower surface hardness is different from that of the second sliding portion 8 that slides with a member having a higher surface hardness. Since it is configured to be lower than the surface hardness, it is possible to suppress rubbing wear occurring at the first sliding portion and the second sliding portion (7, 8) and different other member surface portions, and the clamp member 1 and The life of other members can be extended and the processing accuracy can be improved.

  Further, as described above, the first sliding portion 7 formed on the lock screw member 5 is engraved with an external screw, and the first sliding portion is screwed with another member, whereby the second sliding portion is formed. Each sliding part is formed so that the moving part 8 slides with another member, that is, the lever lock member 6. Therefore, the portion where the external screw having a complicated shape is engraved is formed to have a lower surface hardness. By doing so, since the hardness difference with other members can be reduced, rubbing wear that occurs in the first sliding portion 7 and other members that are screwed together is suppressed, and cracks in the first sliding portion 7 occur. Deficiency can also be suppressed.

  The first sliding portion 7 formed on the lock screw member 5 slides with the holder body 3 and is preferably formed lower than the surface hardness of the holder body 3. With such a configuration, among the surface portions of the lock screw member 5, the surface hardness of the first sliding portion 7 that slides with the holder body 3 having a low surface hardness can be reduced. The difference in surface hardness with the holder screw hole 3A can be reduced. As a result, rubbing wear on the surface portion of the holder body 3 that slides with the first sliding portion 7 can be suppressed, so that the life of the clamp member 1 and the holder body 3 can be extended. Particularly, since the holder body 3 can have a longer life, the number of times the holder body 3 can be replaced can be reduced, so that the holder of this embodiment is excellent in operability and economy.

  At this time, when the surface hardness of the first sliding portion 7 is A and the surface hardness of the holder body 3 is B, the first sliding portion 7 is formed so that 3/4 <A / B <1. Preferably it is done. Thereby, since the difference in surface hardness between the sliding members becomes small, rubbing wear is suppressed in both the first sliding portion and the surface portion of the holder body 3 that slides with the first sliding portion. .

The second sliding portion 8 formed on the lock screw member 5 slides with other members excluding the holder main body 3, that is, the clamp lever member 6, and the second sliding portion 8 is quenched. It is preferable. Since the clamp lever member 6 that slides with the lock screw member 5 is made of a high hardness material as described above, the second sliding portion 8 that slides with the clamp lever member 6 is easily worn. However, as in the present embodiment, by subjecting the portion to quenching , rubbing wear caused by sliding of the second sliding portion 8 and the lever lock member 6 can be suppressed.

In order to perform the quenching process on the second sliding portion 8 in this manner, various curing methods such as laser quenching process and induction quenching can be used. In particular, the hardening process by induction hardening is more preferable because it can easily be partially quenched to a necessary part and is excellent in mass productivity. In addition, as in the case of the second sliding portion 8 (tapered portion) of the present embodiment, when a hard material is formed as a raw material or a hard layer is formed on the entire surface layer, the toughness is locally insufficient, Therefore, it is possible to effectively perform a partial quenching process on a thin portion that is easily cracked and easily broken. In particular, as in this embodiment, when it has a shape that tends to concentrate stress in the vicinity of the second sliding portion 8, it is easy to crack and break, but such a problem is also caused by partially quenching treatment. It can suppress and can show the outstanding processing precision.

  Here, the rubbing wear that occurs between the two members when they slide depends on the difference in surface hardness between the sliding members as described above, and also depends on the surface hardness of each member itself. Dependent. Therefore, it is preferable that the surface hardness of the first sliding portion 7 and the second sliding portion 8 is formed to be 350 HV or more and 850 HV or less. Thereby, not only the difference in surface hardness between the sliding members but also the hardness of the sliding portion itself such as the first sliding portion and the second sliding portion (7, 8) can be sufficiently obtained. Therefore, the wear resistance of the clamp member is improved. As a result, rubbing wear at each sliding portion is suppressed, and the life of the clamp member is extended.

  The surface hardness referred to here is a surface area within 50 μm from the surface of any cross section perpendicular to the surface of the member, measured according to JIS B 7725. By using a micro Vickers hardness tester or the like, it is possible to measure the surface hardness of a complicated shape such as a portion in which an external screw is engraved.

  Next, a second embodiment of the present invention will be described with reference to FIGS. In addition, about the structure substantially the same as 1st embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  4 and 5, the clamp member 1 ′ according to the second embodiment is a member for mounting the insert 2 to the holder body 3, similarly to the clamp member 1 according to the first embodiment. The clamp member 1 (lock screw member 5) of the first embodiment alone cannot mount the insert 2 on the holder body 3 alone, and cooperates with a plurality of other members such as the lever lock member 6 to insert it. 2 was used for a clamp method of mounting 2 on the holder body 3. On the other hand, the clamp member 1 ′ of the second embodiment has a single member, specifically, the clamp screw member 9 alone, and the insert 2 is mounted on the holder body 3 as shown in FIGS. 4 and 5. It is used for the clamping method. In that respect, the clamp members according to the first and second embodiments are different.

  As shown in FIG. 6B, the clamp screw member 9 has a head at one end, and an external screw is engraved at the other end. The insert 2 is attached to the holder main body 3 by inserting the portion in which the external screw is engraved into the insert through hole 2A of the insert 2 and screwing into the holder screw hole 3B formed in the holder main body 3. As in the first embodiment, the clamp screw member 9 includes a first sliding portion and a second sliding portion (7, 8) having the above-described surface hardness relationship, and is a member that slides. Since it can be set as the structure which has different surface hardness correspondingly, the rubbing abrasion in each sliding part can be suppressed.

  Such a clamp screw member 9 is frequently used in other clamp methods, and is not limited to this embodiment, but is applied to other clamp methods and screw members used when an insert is mounted on a holder using a cartridge. However, the same effect can be obtained.

  In this embodiment, the lever lock method and the screw-on method are exemplified as the clamp method. However, the present invention is not limited to this, and the clamp member used in the W clamp method has a portion that slides with other members. You may form the 1st and 2nd sliding part which is the structure of this invention in a member. Thereby, like this embodiment, the rubbing wear which arises when each sliding part slides can be suppressed.

  Furthermore, in the present embodiment, an example has been shown for each of the turning tool and the milling tool. However, the present invention is not limited thereto, and in each of the other milling tools and turning tools, each of the above-described sliding members is attached to the clamp member for mounting the insert on the holder. A part may be formed. For example, the present invention can be applied to a cartridge used when an insert is mounted with a milling tool. By forming the first and second sliding portions in the portions where the cartridge slides with other members (insert and holder main body) different from each other, surface portions having different surface hardness corresponding to the mating member to be slid are formed. Since it can comprise, the abrasion resistance in each sliding part can be improved.

  As mentioned above, although embodiment of this invention was illustrated, this invention is not limited to the said embodiment, It cannot be overemphasized that it can be made arbitrary, unless it deviates from the objective of invention.

1 is an overall perspective view of a turning tool in which a cutting insert is mounted on a cutting tool holder body by a clamp member according to a first embodiment of the present invention. It is (a) top view, (b) short side view, (c) long side view of the turning tool of FIG. It is AA sectional drawing of the turning tool shown to Fig.2 (a). 1 is an overall perspective view of a milling tool in which a cutting insert is mounted on a cutting tool holder body by a clamp member according to a reference example of the present invention. 5A is a plan view of the milling tool of FIG. 4 and FIG. 5B is a side view of a short side. It is AA sectional drawing of the milling tool shown in FIG.5 (b).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1 'clamp member 2 Cutting insert 2A Insert through-hole 3 Cutting holder main body 3A 3B Holder screw hole 4 Cutting holder 5 Lock screw member 6 Clamp lever member 7 First sliding part 8 Second sliding part 9 Clamp screw member

Claims (3)

A clamp member for fixing a cutting insert to a holder body for a cutting tool,
A first sliding portion and a second sliding portion that slide with different members on the surface portion of the clamp member,
The first sliding portion is engraved with an external screw, and the first sliding portion is screwed with the cutting tool holder main body, so that the second sliding portion is attached to the cutting tool holder main body. Sliding with other members,
A screw head is provided at the tip of the clamp member following the first sliding portion, and a jig is fitted on the top surface of the screw head to rotate the clamp member to the holder body. A recess for fitting is provided,
By quenching the second sliding portion provided at a position farther than the first sliding portion with respect to the screw head,
The surface hardness of the first sliding portion and the screw head is lower than the surface hardness of the second sliding portion, the surface hardness of the first sliding portion is A, the surface of the cutting tool holder body A clamp member , wherein 3/4 <A / B <1 when the hardness is B, and the surface hardness of the first and second sliding portions is 350 HV or more and 850 HV or less . The hardening process, the clamping member according to claim 1, characterized in that the induction hardening process. Claims 1 to 2 holder for a cutting tool having a clamping member according to any one.

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