KR20130067773A - Cutting head and tool holder and cutting tool assembly with the same - Google Patents

Abstract

The cutting tool assembly according to an embodiment of the present invention includes a cutting head, a tool holder, a first contact portion, a second contact portion, and a third contact portion. The cutting head includes the shank and the male threads and the valleys of the male threads. The shank has a flange face at one end and extends outward from the flange face. The floor of the male thread and the valley of the male thread are formed on the outer peripheral surface of the shank. The toolholder includes the receptacle and the floor of the female thread and the valley of the female thread. The receptacle receives the shank. The floor of the female thread and the valley of the female thread are formed on the inner circumferential surface of the receiving portion to correspond to the valley of the male thread and the floor of the male thread, respectively. The first contact portion in which the flange face is in surface contact with the cutting head is oriented perpendicular to the central axis of the cutting head. The second contact portion in which the floor and shank of the male thread is in surface contact with the valley of the female thread is oriented obliquely with respect to the central axis of the cutting head. The third contact portion is a portion where the bone of the male thread is in line or point contact with the floor of the female thread during cutting.

Description

CUTTING HEAD AND TOOL HOLDER AND CUTTING TOOL ASSEMBLY WITH THE SAME}

The present invention relates to a cutting tool assembly having a cutting head, a tool holder, and a cutting head and a tool holder.

BACKGROUND OF THE INVENTION Cutting tools are widely known in which the cutting head is detachable from the tool holder in case the cutting head is worn or damaged. For example, the male thread may be formed in the cutting head and the female thread may be formed in the tool holder. The cutting head is detached from the tool holder by screwing the male thread of the cutting head and the female thread of the tool holder. As disclosed in Patent Document 1 below, when there are many threads of the male thread of the cutting head and the female thread of the tool holder, it is troublesome for the operator to rotate the cutting head several times with respect to the tool holder. In addition, there is a problem that increases the time and cost required to process a large number of threads in the cutting head and the tool holder.

US 5,971,670

In order to solve the above problems of the present invention, an object of the present invention is to provide a cutting head, a tool holder, a cutting head and a tool holder which can improve the coupling force between the cutting head and the tool holder while having a small thread. It is to provide a cutting tool assembly provided.

The cutting tool assembly according to an embodiment of the present invention includes a cutting head, a tool holder, a first contact portion, a second contact portion, and a third contact portion. The cutting head includes the shank and the male threads and the valleys of the male threads. The shank has a flange face at one end and extends outward from the flange face. The floor of the male thread and the valley of the male thread are formed on the outer peripheral surface of the shank. The toolholder includes the receptacle and the floor of the female thread and the valley of the female thread. The receptacle receives the shank. The floor of the female thread and the valley of the female thread are formed on the inner circumferential surface of the receiving portion to correspond to the valley of the male thread and the floor of the male thread, respectively. The first contact portion in which the flange face is in surface contact with the cutting head is oriented perpendicular to the central axis of the cutting head. The second contact portion in which the floor and shank of the male thread is in surface contact with the valley of the female thread is oriented obliquely with respect to the central axis of the cutting head. The third contact portion is a portion where the bone of the male thread is in line or point contact with the floor of the female thread during cutting.

The floor of the male thread may have an outer diameter that decreases as it moves away from the flange face. The male thread can have a constant outer diameter.

The shank may have an outer diameter that decreases as it moves away from the flange face. The shank may comprise a first shank and a second shank that steps from the first shank to have a diameter smaller than the first shank. The floor of the male thread and the valley of the male thread may be provided on the outer circumferential surface of the second shank.

The floor of the male thread may have an outer diameter that decreases as it moves away from one end of the second shank. The male thread can have a constant outer diameter. In this embodiment, the second contact portion in which the first shank is in surface contact with the valley of the female thread may be oriented inclined with respect to the central axis of the cutting head. The floor of the male thread provided in the second shank is spaced apart from the bone of the female thread.

The female threaded valley may have an inner diameter that decreases as it goes inward from one end of the toolholder. The floor of the internal thread may have a constant inner diameter.

The floor of the female thread may include a floor of the first female thread and a floor of the second female thread having an inner diameter smaller than that of the first female thread.

The floor of the first female thread is spaced apart from the bone of the male thread, and the floor of the second female thread may be in line or point contact with the bone of the male thread during cutting.

The cutting head according to an embodiment of the present invention may include a cutting portion, a shank, and an external thread. The shank has a flange face at one end and an outer diameter that decreases as it moves away from the flange face. Male threads are formed on the outer circumferential surface of the shank. The male screw includes a floor of the male screw having an outer diameter that decreases as it moves away from the flange face, and a valley of the male screw having a constant outer diameter.

The shank may include a first shank and a second shank that forms a step from the first shank to have a smaller outer diameter than the first shank.

Tool holder according to an embodiment of the present invention includes a receiving portion and a female screw. The receiving portion is formed concave inward from one end. The female screw includes a female screw formed on the inner circumferential surface of the receiving portion. The female screw includes a valley of the female screw having an inner diameter that decreases as it goes from one end to the inside, and a floor of the female screw having a constant inner diameter.

The floor of the female thread may include a floor of the first female thread and a floor of the second female thread that forms a step from the floor of the first female thread so as to have an inner diameter smaller than that of the first female thread.

Since the cutting tool assembly of the present invention has first to third contacts oriented in different directions, it is possible to increase the friction force between the cutting head and the tool holder to improve the bonding force therebetween.

Since the cutting head and the tool holder of the present invention have a small number of threads, it is possible to reduce the time and cost required to machine the male and female threads in the cutting head and the tool holder.

In addition, the cutting head is provided with the floor of the male thread forming a step from the shank, so that the coupling between the cutting head and the tool holder can be facilitated.

In addition, the toolholders have floors of female threads that are stepped on each other, thereby facilitating engagement between the cutting head and the toolholders.

1 is a perspective view showing a cutting tool assembly according to an embodiment of the present invention.
FIG. 2 is a perspective view illustrating the cutting head of FIG. 1. FIG.
3 is a perspective view illustrating the tool holder of FIG. 1.
4 is a partial cross-sectional view taken along line IV-IV of FIG. 3.
5 is a partial cross-sectional view along the line VV of FIG. 1.
6 is a perspective view illustrating a cutting head according to another embodiment.
FIG. 7 is a partial cross-sectional view illustrating a state in which the cutting head of FIG. 6 is mounted to the tool holder of FIG. 1.
8 is a partial cross-sectional view showing a tool holder according to another embodiment.
9 is a partial cross-sectional view illustrating a state in which the cutting head of FIG. 1 is mounted on the tool holder of FIG. 8.

Hereinafter, embodiments of the cutting head and the tool holder will be described with reference to the accompanying drawings.

Referring to FIG. 1, a cutting tool assembly according to an embodiment of the present invention includes a cutting head 100 and a tool holder 200. The cutting head 100 has a first central axis C1 and the tool holder 200 has a second central axis C2. When the cutting head 100 and the tool holder 200 are coupled, the first central axis C1 and the second central axis C2 are completely coincident with each other.

The cutting head 100 includes a cutting unit 110, a shank 120, and an external thread 130. The cutting head 100 is detachably coupled to the tool holder 200. The cutting head 100 is rotated by the rotation of the tool holder 200 or the tool body to cut the workpiece. The cutting head 100 may be made of cemented carbide and formed integrally.

The cutting unit 110 may be processed by grinding as a part used to cut the workpiece. Shank 120 is used to couple the cutting head 100 and the tool holder 200. The shank 120 has a flange face 121 perpendicular to the first central axis C1 at one end. The flange surface 121 forms a boundary between the cutting portion 110 and the shank 120. The shank 120 extends outwardly along the first central axis C1 from the flange face 121. The outer diameter of the shank 120 is smaller than the outer diameter of the flange face 121. The outer diameter of the shank 120 is formed to decrease as it goes from the flange face 121 to the end. That is, the shank 120 is tapered or truncated cone.

The male screw 130 may be formed by grinding the outer circumferential surface of the shank 120. In this embodiment, the male screw 130 has a rectangular shape, but the shape of the male screw 130 is not limited thereto and may have another shape such as a trapezoid. As shown in FIG. 2, male screw 130 includes a crest of male thread 131 and a root of male thread 132. The male threads 131 and the male threads 132 may be formed by cutting a helical groove (ie, the male threads 132) in the outer circumferential surface of the shank 120. Thus, the outer diameter of the ridge 131 of the male thread coincides with the outer diameter of the shank 120. That is, the floor 131 of the male thread is formed such that its outer diameter decreases as it goes from the flange face 121 to the end portion along the first central axis C1. A straight line A connecting the ridges 131 of the male screw has an angle α with respect to the first central axis C1. The outer diameter of the valley 132 of the male thread is formed uniformly along the first central axis C1. That is, the height between the floor 131 of the male thread and the valley 132 of the male thread decreases as the distance from the flange surface 121 is along the first central axis C1.

Tool holder 200 includes a receiving portion 210 and the female screw 220. The receiving portion 210 is a portion for receiving the shank 120 of the cutting head 100. As shown in FIG. 3, the accommodating part 210 is formed to be concave inward from one end 201 of the tool holder 200. One end 201 is a plane perpendicular to the second central axis C2 and has a ring shape. The receiving portion 210 may be processed together with the female screw 220.

Female screw 220 is formed on the inner peripheral surface of the receiving portion (210). As shown in FIG. 4, female screw 220 includes a crest of female thread 221 and a root of female thread 222. The inner diameter of the ridge 221 of the internal thread is constantly formed along the second central axis C2. The female threaded bone 222 is formed to decrease as its inner diameter goes inward from one end of the receiving portion 210 along the second central axis C2. That is, the straight line B connecting the valleys 222 of the female thread has an angle α with respect to the second central axis C2. The female threaded floor 221 corresponds to the shape and size of the male threaded valley 132, and the female threaded groove 222 corresponds to the shape and size of the male threaded floor 131.

As shown in FIG. 5, when the shank 120 of the cutting head 100 is mounted to the receiving portion 210 of the tool holder 200, the flange surface 121 is in surface contact with the one end portion 201. 1 Make contact. The first contact is perpendicular to the first and second central axes C1, C2. The floor 131 of the male thread makes surface contact with the valley 222 of the female thread to form a second contact portion. The second contact portion has an angle α with respect to the first and second central axes C1, C2. When a cutting force is applied to the cutting head 100 during cutting, a bending moment may occur in the shank 120. By this bending moment, the bone 132 of the male thread can be in line contact or point contact with the floor 221 of the female thread. In this case, the third contact portion is a portion where the bone 132 of the male thread is in line contact or point contact with the floor 221 of the female thread. Since the first to third contact portions are oriented in different directions, the friction force acting between the cutting head 100 and the tool holder 200 increases. Therefore, the cutting head 100 and the tool holder 200 may be firmly coupled to each other by a combination of the first to third contacts.

Preferably, the angle α is 3 degrees. If the angle α is excessively greater than 3 degrees, the friction force between the shank 120 and the receiving portion 210 becomes large, and it is not easy to screw the shank 120 to the receiving portion 210. On the contrary, when the angle α is smaller than 3 degrees, the second contact portion may be inclined and may not achieve the effect of the present invention, which may increase the coupling force between the cutting head 100 and the tool holder 200. .

6 and 7 show a cutting head according to another embodiment. The cutting head 300 illustrated in FIGS. 6 and 7 may have the same components as the cutting head 100 illustrated in FIGS. 1 to 5. The same components are represented by the same reference numerals as the cutting head 100 shown in FIGS. 1 to 5. Hereinafter, differences between the cutting head 100 shown in FIGS. 1 to 5 and the cutting head 300 shown in FIGS. 6 and 7 will be described.

6 and 7, the cutting head 300 according to another embodiment includes a cutting part 110, a shank 320, and an external thread 330.

As shown in FIG. 6, the shank 320 includes a first shank 321 having no male thread 330 and a second shank 322 having a male thread 330. The first shank 321 is disposed adjacent to the flange face 121, and the second shank 322 is disposed adjacent to the first shank 321. The outer diameters of the first and second shanks 321 and 322 are formed to decrease as they go from the flange face 121 to the ends. The second shank 322 forms a step d with the first shank 321. That is, the outer diameter of the second shank 322 is smaller than the outer diameter of the first shank 321.

The external thread 330 is formed on the outer circumferential surface of the second shank 322 and includes a floor 331 of the external thread and a valley 332 of the external thread. The floor 331 of the male thread forms a step d with the first shank 321 and is formed such that its outer diameter decreases as it goes from the first shank 321 to the end. The male thread 332 is constantly formed along the first central axis C1. That is, the outer diameter of the male threaded bone 332 is the same as the outer diameter of the male threaded bone 132 shown in FIGS. 1 to 5.

As shown in FIG. 7, when the shank 320 of the cutting head 300 is mounted to the receiving portion 210 of the tool holder 200, the flange surface 121 is in surface contact with the one end portion 201. 1 Make contact. The first contact is perpendicular to the first and second central axes C1, C2. The first shank 321 is in surface contact with the inner circumferential surface of the receiving portion 210 to form a second contact portion. The second contact portion has an angle α with respect to the first and second central axes C1, C2. When a cutting force is applied to the cutting head 300, the bending moment may occur in the shank 320. By this bending moment, the bone 332 of the male thread can be in line contact or point contact with the floor 221 of the female thread. In this case, the third contact portion is a portion where the bone 332 of the male thread is in line contact or point contact with the floor 221 of the female thread. Since the first to third contact portions are oriented in different directions, the friction force acting between the cutting head 300 and the tool holder 200 increases. The male threads 331 and the female threads 222 are spaced apart from each other by a step d. As a result, while the cutting head 300 and the tool holder 200 are firmly coupled by the combination of the first to third contacts, the screw 320 of the shank 320 with respect to the receiving portion 210 can be facilitated. .

8 and 9 show a toolholder according to another embodiment. The tool holder 400 illustrated in FIGS. 8 and 9 may have the same components as the tool holder 200 illustrated in FIGS. 1 to 5. The same components are represented by the same reference numerals as the tool holder 200 shown in FIGS. 1 to 5. Hereinafter, the difference between the tool holder 200 shown in FIGS. 1 to 5 and the tool holder 400 shown in FIGS. 8 and 9 will be described.

8 and 9, the tool holder 400 according to another embodiment includes a receiving portion 210 and a female screw 420.

As shown in FIG. 8, the female thread 420 includes a first crest of female thread 421, a second crest of female thread 422, and a female thread. (423). The floors 421 and 422 of the first and second female threads each have a constant inner diameter. The floor 421 of the first female thread forms a step d with the floor 422 of the second female thread. The inner diameter of the ridge 421 of the first female thread is larger than the inner diameter of the ridge 422 of the second female thread. The inner diameter of the bone 423 of the female screw is formed to decrease as it goes inward from the one end 201. That is, the inner diameter of the female threaded bone 423 is the same as the internal diameter of the female threaded bone 222 shown in FIGS. 1 to 5.

As shown in FIG. 9, when the shank 120 of the cutting head 100 is mounted to the receiving portion 210 of the tool holder 400, the flange surface 121 is in surface contact with the one end 201. 1 Make contact. The first contact is perpendicular to the first and second central axes C1, C2. The floor 131 of the male screw is in surface contact with the valley 423 of the female screw to form a second contact portion. The second contact portion has an angle α with respect to the first and second central axes C1, C2. When a cutting force is applied to the cutting head 100, the bending moment may occur in the shank 120. By this bending moment, the bone 132 of the male thread can be in line contact or point contact with the floor 422 of the second female thread. In this case, the third contact portion is a portion where the bone 132 of the male thread is in line contact or point contact with the floor 422 of the second female thread. Since the first to third contact portions are oriented in different directions, the friction force acting between the cutting head 100 and the tool holder 200 increases. The male thread 132 and the floor 421 of the first female thread are spaced apart from each other by a step d. As a result, while the cutting head 100 and the tool holder 400 are firmly coupled by the combination of the first to third contacts, the screw 120 of the shank 120 with respect to the receiving portion 210 can be facilitated. .

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. It will be clear to those who have knowledge of.

100: cutting head of one embodiment
110: cutting part
120: shank
130: Male thread
131: crest of male thread
132: root of female thread
200: tool holder of one embodiment
210: receiver
220: female thread
221: crest of male thread
222: root of female thread
300: cutting head of another embodiment
320: shank
321: first shank
322: second shank
330: external thread
331: floor of male thread
332: male thread
400: Tool holder of another embodiment
420: female thread
421: first crest of female thread
422: second crest of female thread
423: goal of female thread

Claims (12)

A cutting head having a shank at one end and extending outwardly from the flange, a cutting head having a floor of a male thread and a valley of a male thread formed on an outer circumferential surface of the shank;
A tool holder having an accommodating portion for accommodating the shank, an inner circumferential surface of the accommodating portion, and having a trough of the male thread and a trough of the female thread respectively corresponding to the trough of the male thread;
A first contact portion in which the flange surface is in surface contact with the one end of the tool holder with respect to the central axis of the cutting head;
A second contact portion in which the floor and the shank of the external thread are in surface contact with the valley of the female thread inclined with respect to the central axis of the cutting head;
A third contact portion in which the bone of the male thread is in line or point contact with the floor of the female thread during cutting;
Cutting tool assembly comprising a. The floor according to claim 1, wherein the floor of the male screw has an outer diameter that decreases as it moves away from the flange surface.
The male thread has a constant outer diameter,
Cutting tool assembly. The shank of claim 1, wherein the shank has an outer diameter that decreases with distance from the flange surface,
The shank includes a first shank and a second shank that forms a step from the first shank to have a smaller outer diameter than the first shank,
The floor of the male thread and the valley of the male thread are provided on the outer circumferential surface of the second shank,
Cutting tool assembly. 4. The floor of claim 3 wherein the floor of the male thread has an outer diameter that decreases away from one end of the second shank,
The male thread has a constant outer diameter,
Cutting tool assembly. The method of claim 4, wherein the second contact portion in which the first shank is in surface contact with the bone of the female thread is oriented inclined with respect to the central axis of the cutting head,
The floor of the male thread provided in the second shank is spaced apart from the bone of the female thread,
Cutting tool assembly. According to claim 1, wherein the female threaded bone has an inner diameter that decreases as it goes inward from the one end of the tool holder,
The floor of the female thread has a constant inner diameter,
Cutting tool assembly. The method of claim 6, wherein the floor of the female screw,
Maruwa of the first female thread,
A floor of the second female thread having an inner diameter smaller than the floor of the first female thread,
Cutting tool assembly. The method of claim 7, wherein the floor of the first female screw is spaced apart from the bone of the male screw,
The floor of the second female thread is in line or point contact with the bone of the male thread during cutting.
Cutting tool assembly. Cutting section,
A shank having a flange face at one end and having an outer diameter that decreases as it moves away from the flange face,
It includes a male screw formed on the outer peripheral surface of the shank,
The male screw includes a floor of a male thread having an outer diameter that decreases as it moves away from the flange surface, and a valley of a male thread having a constant outer diameter.
Cutting head. The method of claim 9, wherein the shank,
With the first shank,
A second shank stepped from the first shank to have an outer diameter smaller than the first shank,
Cutting head. A receiving portion formed concave inwardly from one end portion,
It includes a female screw formed on the inner peripheral surface of the receiving portion,
The female screw includes a bone of the female screw having an inner diameter that decreases as it goes inwardly from the one end, and a floor of the female screw having a constant inner diameter.
Tool holder. The floor of the female screw according to claim 11,
Maruwa of the first female thread,
A floor of the second female thread that makes a step from the floor of the first female thread to have a smaller inner diameter than the floor of the first female thread,
Tool holder.

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