KR20150049905A - cutting tool having pentagonal cutting insert - Google Patents

Abstract

The present invention relates to a cutting tool having a pentagonal groove cutting insert and, specifically, to the cutting tool having a pentagonal groove cutting insert, which has five cutting units in one cutting insert, and the cutting units can be exchanged to be used. According to the cutting tool having a pentagonal groove cutting insert of the present invention, an upper area and a lower area of a cutting insert is supported by an upper support protrusion and a lower support protrusion of an insert holder in a rear direction. Thus, when a process, a distribution force which is applied to the cutting insert is appropriately supported to prevent the cutting insert from being pushed to a rear direction, thereby improving intensity of illumination of a surface for a processed object.

Description

Cutting tool having a pentagonal groove cutting insert {cutting tool having pentagonal cutting insert}

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a cutting tool equipped with a pentagonal groove cutting insert, and is equipped with five cutting portions in one cutting insert to replace a cutting portion, .

The reaction force received by the cutting edge of the cutting insert in the tangential direction of the workpiece is called the main component force, and the reaction force received in the direction of entry of the cutting edge is called the distribution force.

In the conventional multi-blade cutting insert, a gap is formed between the cutting insert and the support portion of the insert holder when the cutting insert is mounted on the insert holder, and the cutting insert is thrown inward of the insert holder at the time of machining. Such milling of the cutting insert causes poor surface roughness of the workpiece. In addition, since the cutting insert can be pushed backward, the cutting insert may be shaken at the time of machining, and breakage of the cutting insert may occur.

A prior art for cutting inserts is US Patent Publication No. US2012 / 0099935.

The present invention provides a cutting tool capable of preventing the shaking of the cutting insert during cutting to obtain a good surface profile and at the same time improving the durability of the cutting insert and minimizing the load imposed by the set screw, thereby prolonging the life of the set screw .

It is an object of the present invention to provide a cutting tool comprising a cutting insert and an insert holder, wherein the cutting inserts are symmetrically formed in the circumferential direction of the first to fifth cutting sections having front, rear and cutting edges respectively, Wherein the insert holder is formed with a receiving pocket in which the cutting insert is seated at a front end thereof, and an upper support protrusion protruding toward the receiving pocket is formed at an upper portion of the receiving pocket, A lower support protrusion protruding toward the receiving pocket is formed, and two clearance grooves accommodated in the cutting portion of the cutting insert are formed between the upper support protrusion and the lower support protrusion, Wherein the upper support projection has a front surface surface contacting the front surface of the cutting portion of the cutting insert, And a rear support portion contacting the rear surface of the cutting portion of the cutting insert is formed and the lower support protrusion is formed with a rear surface support portion contacting the rear surface of the cutting portion of the cutting insert, The center of the fixing screw engagement hole of the insert holder is eccentrically upwardly and rightly eccentrically relative to the center of the insert hole of the cutting insert in a state where the insert hole is seated in the receiving pocket of the insert holder, Wherein the fastening screw causes a biasing force to push the cutting insert to the upper right side of the receiving pocket of the insert holder and, when the cutting insert is fixed to the insert holder, At least a part of the front surface abuts against the front supporting portion of the upper supporting projection, At least a part of the rear surface of the third cutting portion abuts against the rear surface supporting portion of the upper supporting projection and at least a part of the rear surface of the fifth cutting portion abuts against the rear surface supporting portion of the lower supporting projection, The tangent of the front face of the second cutting portion, the tangent of the front supporting portion of the upper supporting protrusion, the rear face of the fifth cutting portion and the rear supporting portion of the lower supporting protrusion diverges forward, Wherein the tangent line (201) of the front surface supporting portion and the rear surface of the third cutting surface and the tangent line (202) of the rear surface supporting portion of the upper supporting protrusion diverge forward A cutting tool with a perforated groove cutting insert is provided.

In order to achieve the above object, the screw thread direction of the threaded fastening hole of the insert holder is such that when the fastening screw is rotated in the direction of the main component of the cutting insert, the fastening screw is locked to the fastening screw engagement hole Direction.

In order to achieve the above object, the front supporting portion of the upper supporting protrusion is formed in a curved surface, and the rear supporting portion of the upper supporting protrusion and the rear supporting portion of the lower supporting protrusion are formed in a plane, Wherein the front support portion of the projection is in line contact with the cutting insert and the front surface, and the rear support portion of the upper support projection and the rear surface support portion of the lower support projection are in surface contact with the rear surfaces of the cutting insert .

According to the cutting tool equipped with the pentagonal groove cutting insert according to the present invention, the upper region and the lower region of the cutting insert are supported from the rear by the upper support protrusions and the lower support protrusions of the insert holder, so that the distribution force So that the cutting insert is prevented from being pushed to the rear side of the insert holder, thereby improving the surface roughness of the workpiece.

Further, since the cutting insert is prevented from being pushed back by the dispensing force during cutting, it is possible to prevent the cutting insert from being damaged due to vibration in the cutting insert.

Also, since the fixing screw coupling hole for fixing the cutting insert to the insert holder through the fixing screw is biased to the upper right side of the insert holder than the insert hole of the cutting insert, when the cutting insert is coupled to the insert holder by the fixing screw, The main force and the distribution force received by the cutting insert are appropriately supported by the reaction force of the upper support protrusions and the lower support protrusions of the insert holder, and at the same time, the cutting insert is supported by the cutting insert Since the main component force and the distribution force acting on the fastening screw are hardly burdened, the lifetime of the fastening screw is prolonged and the replacement time of the fastening screw is prolonged.

Further, since the screw thread of the cutting insert fixing screw is formed in the direction in which the main component acts, that is, in the direction in which the fixing screw is locked to the insert holder when rotating in the direction in which the fixing screw receives the rotational force by the main component, It is possible to prevent the fixing screw from being loosened from the insert holder during processing.

FIG. 1 is a perspective view of a cutting tool equipped with a pentagonal groove cutting insert according to a preferred embodiment of the present invention,
2 is a perspective view of a cutting insert of a cutting tool equipped with a pentagonal groove cutting insert according to a preferred embodiment of the present invention,
3 is a perspective view showing a front portion of an insert holder of a cutting tool equipped with a pentagonal groove cutting insert according to a preferred embodiment of the present invention,
4 is a front view showing a front portion of an insert holder of a cutting tool equipped with a pentagonal groove cutting insert according to a preferred embodiment of the present invention,
5 is a front view showing a mounting state of a cutting insert of a cutting tool equipped with a pentagonal groove cutting insert according to a preferred embodiment of the present invention,
6 is a view showing a direction of a biasing force between a cutting insert and an insert holder of a cutting tool equipped with a pentagonal groove cutting insert according to a preferred embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the present invention are shown.

FIG. 1 is a perspective view illustrating a cutting tool equipped with a pentagonal groove cutting insert according to a preferred embodiment of the present invention. FIG. 2 is a perspective view of a cutting insert of a cutting tool equipped with a pentagonal groove cutting insert according to a preferred embodiment of the present invention. FIG. 3 is a perspective view showing a front portion of an insert holder of a cutting tool equipped with a pentagonal groove cutting insert according to a preferred embodiment of the present invention, FIG. 4 is a perspective view of a pentagonal groove cutting insert according to a preferred embodiment of the present invention, FIG. 5 is a front view showing a mounting state of a cutting insert of a cutting tool equipped with a pentagonal groove cutting insert according to a preferred embodiment of the present invention, and FIG. 5 is a front view showing a front portion of the insert holder of the cutting tool, 6 is a view showing the direction of the biasing force between the cutting insert and the insert holder of the cutting tool equipped with the pentagonal groove cutting insert according to the preferred embodiment of the present invention A.

1 to 6, a cutting insert 1 of a cutting tool (hereinafter, referred to as a "cutting tool") equipped with a pentagonal groove cutting insert according to a preferred embodiment of the present invention has a clock The first cutting portion 10, the second cutting portion 10 ', the third cutting portion 10' ', the fourth cutting portion 10' '', and the fifth cutting portion 10 '' 'in this order. 10 ', 10' ', 10' '' ', 10' '' 'having five cutting portions 10, 10', 10 ' , 10 '' ''), and each of the cuts 10 has a front surface 11, 11 'and a rear surface 12, 12' ', 12' '' 13 and a flank surface 14 and a cutting edge 15 is formed at a point where the rake surface 13 and the flank surface 14 cross each other. The front faces 11 and 11 'are formed such that the radially outer portion is flat and the inner portion is curved so as to smoothly connect to the rear faces 12, 12' 'and 12' '' ', 12 ", 12 " ") are formed in a plane.

At the center of the cutting insert (1), an insert hole (2) for inserting a setscrew is formed.

The insert holder 100 is provided at its front end with a receiving pocket 110 having a space for receiving the cutting insert 1 and a seating surface 111 and an upper support protrusion The lower support protrusions 130 are formed on the lower support protrusions 120 and the lower support protrusions 130 are formed between the upper support protrusions 120 and the lower support protrusions 130, The clearance grooves 115 and 116 are formed.

3 to 5, the upper support protrusion 120 is formed in a curved shape and has a front supporting portion 121 contacting the front surface 11 'of the cutting insert 1, The rear surface support portion 122, which contacts the surface 12 '', is formed in a plane.

The lower support protrusion 130 is formed in a planar shape with the rear support portion 132 contacting the rear surface 12 '' '' of the cutting insert 1 as shown in FIGS. 3-5.

A screw connection hole 112 having a screw thread is formed at one point of the receiving pocket 110 of the insert holder 100 and the center of the fixing screw coupling hole 112 is formed at the center of the receiving pocket 110 The cutting insert 1 is formed eccentrically to a position right above the center of the insert hole 2 of the cutting insert 1. The straight line D shown in Fig. 6 indicates a straight line passing through the center of the insert hole 2 and the center of the fixing screw engaging hole 112, and indicates the eccentric direction. The critical angle alpha (alpha °) is preferably in the range of 10 to 20 degrees.

Therefore, when the cutting insert 1 is placed in the receiving pocket 110 of the insert holder 100 and the fixing screw is inserted to fix the cutting insert 1, the insert hole 2 and the insert holder 100 of the cutting insert 1, The cutting insert 1 is fixed to the insert holder 100 while being pressed toward the upper right side by the fixing screw.

In this state, the front surface 11 'of the second cutting portion 10' is in close contact with the front surface supporting portion 121 of the upper supporting protrusion 120 and the rear surface 12 '' of the third cutting portion 10 ' 'Are brought into close contact with the rear supporting portion 122 of the upper supporting protrusion 120. Here, the contact between the front face 11 'of the second cutting portion 10' and the front face supporting portion 121 of the upper supporting protrusion 120 is a line contact, and the rear face of the third cutting portion 10 ' 12 '' and the rear support portion 122 of the upper support protrusion 120 are brought into surface contact.

The rear surface 12 '' '' of the fifth cutting portion 10 '' '' is also in close contact with the rear surface supporting portion 132 of the lower supporting protrusion 130, wherein the fifth cutting portion 10 '' ' '' Of the lower support protrusion 130 and the rear support portion 132 of the lower support protrusion 130 are brought into surface contact.

At this time, the tangent line 201 between the front surface 11 'of the second cutting portion 10' and the front surface supporting portion 121 of the upper supporting protrusion 120 and the rear surface of the fifth cutting portion 10 '' ' The tangent line 203 of the rear surface support portion 132 of the lower support projection 130 diverges forward and the front surface 11 'of the second cutting portion 10' The tangent line 201 of the front support portion 121 of the support projection 120 and the rear surface 12 '' of the third cutting portion 10 '' and the rear support portion 122 of the upper support projection 120 The tangent line 202 diverges forward.

In this state, the cutting edge 15 of the first cutting portion 10 of the cutting insert 1 performs machining.

In this state, when the first cutting portion 10 performs machining, the main force F1 received by the cutting insert 1 tends to rotate the cutting insert 1 in the counterclockwise direction T1 with respect to the point G The reaction force R2 of the rear surface support portion 122 of the upper support protrusion 120 of the insert holder 100 and the reaction force R3 of the rear surface support portion 132 of the lower support protrusion 130 are different from each other in the cutting insert 1, Thereby preventing the rotation of the motor in the counterclockwise direction. Therefore, the cutting insert 1 is prevented from being raised (rotated) in the direction of the main component force F1 at the time of machining. In addition, since the direction in which the main force F1 applies the rotational force to the cutting insert 1 and the direction in which the biasing force of the fixing screw applies the rotational force to the cutting insert 1 are the same with respect to the G point, (F1). Therefore, the fixing screw by the cutting insert 1 is hardly subjected to the load due to the main component force F1.

The distribution force F2 received by the cutting insert 1 at the time of machining acts in the direction of pushing the cutting insert 1 to the inside of the receiving pocket 110 of the insert holder 100, The reaction force R1 of the front support portion 121 of the upper support protrusion 120 of the lower support protrusion 130 and the reaction force R3 of the rear surface support portion 132 of the lower support protrusion 130 closely contact and support the cutting insert 1 from behind. Therefore, the milling force F2 does not cause the cutting insert 1 to be pushed toward the inside of the insert holder 100. Also, since the fastening screw is eccentric so as to push the cutting insert 1 inwardly of the insert holder 100 in the same direction as the distribution force F2, the fastening screw does not bear the distribution force F2 directly. Therefore, at the time of machining by the cutting insert 1, the fixing screw is hardly burdened by the distribution force F2.

The cutting insert 1 according to the present invention is capable of grinding the cutting insert 1 because the upper support protrusions 120 and the lower support protrusions 130 properly support the main force F1 and the distribution force F2, And the cutting insert 1 does not rotate at all, and firmly maintains the position of the cutting insert 1 in the receiving pocket 110 of the insert holder 100. Therefore, the roughness of the machined surface is improved at the time of machining, and the cutting insert 1 is not shaken.

With reference to the fastening screw, the load on the fastening screw does not occur because the load on the counterclockwise direction due to the main force (F1) is prevented by R3 relative to the primary force (F1). Also, the main force F1 acts in the direction of rotating the cutting insert 1 in the counterclockwise direction. Since the fixing screw is eccentrically coupled to push the cutting insert 1 counterclockwise with respect to the point G, The direction of the force F1 and the direction of the biasing force coincide with each other and as a result the burden is not exerted on the load caused by the main force F1.

The reaction force R1 and the reaction force R3 with respect to the distribution force F2 support the cutting insert 1 at the rear of the cutting insert 1 and the fixing screw is fixed to the cutting insert 1 by eccentric engagement, Since the insert hole 2 is pushed inward of the insert holder 100, the fixing screw does not bear the distribution force F2 directly but the reaction force R1 and the reaction force R3 bear the distribution force F2. Therefore, a load burden due to the distribution force F2 hardly occurs in the fixing screw.

In the conventional cutting insert, the upper portion of the cutting insert is spaced apart from the support protrusion of the insert holder, so that the cutting insert is pushed backward during machining, resulting in poor surface roughness and shaking of the cutting insert, resulting in breakage of the cutting insert.

The cutting insert 1 is supported by the upper support protrusion 120 and the lower support protrusion 130 of the insert holder 100 in close contact with each other so that the cutting insert 1 is supported by the cutting force F2, So that the cutting insert 1 is prevented from being pushed, so that the poor surface roughness of the machined surface does not occur.

Since both R1 and R3 support the distributing force F2 and the deflecting direction of the fixing screw is directed to the inside of the insert holder 100 (in the direction of straight line D on the upper right side in FIG. 6), the cutting insert 1 The fixing screw for fixing does not bear the distribution force F2 directly. Therefore, the service life of the fastening screw is prolonged and the replacement time of the fastening screw is prolonged.

6, when the fixing screw is rotated in a counterclockwise direction, the fixing screw is locked in the insert holder 100, and when the fixing screw is rotated clockwise, the fixing screw is engaged with the fixing screw And the helical direction of the thread of the hole 112 is formed. Therefore, when the fixing screw of the cutting insert 1 and the fixing screw engaging hole 112 of the insert holder 100 are rotated in the counterclockwise direction with reference to FIG. 6, And is formed to be locked to the hole 112. Therefore, the main force F1 received by the cutting insert 1 at the time of machining acts in the direction of rotating the cutting insert 1 in the counterclockwise direction, that is, in the direction T1 in which the fixing screw is locked to the insert holder 100 It is prevented that the fixing screw is loosened from the insert holder 100. If the spiral direction of the fixing screw is opposite, the screw may be loosened by the main force F1.

6, the rear supporting portion 132 of the lower supporting protrusion 130 of the insert holder 100 is worn or aged due to the continuous action of the main force during processing, And the supporting surface 132 of the supporting surface 132 is slightly recessed downward. However, in the cutting tool according to the present invention, since the fixing screw presses the cutting insert 1 eccentrically in the upward and rightward direction, the rear supporting portion 132 of the lower supporting protrusion 130 wears down and sinks somewhat downward The cutting insert 1 is held in close contact with the upper support protrusion 120 by the biasing force of the fixing screw so that the cutting insert 1 slightly rotates counterclockwise and the height of the cutting edge 15 The amount of decrease in the height H of the cutting edge 15 is insignificant because the cutting insert 1 pushes the cutting insert 1 to the upper right side of the insert holder 100 although it is slightly lowered. The height H of the cutting edge 15 of the cutting insert 1 due to the amount of eccentricity? Toward the upper right side of the fixing screw even if the rear supporting portion 132 of the lower supporting protrusion 130 is worn by the main component force. So that it is possible to maintain a good cutting condition for a long period of time.

As described above, according to the cutting tool according to the present invention having the above-described structure, the upper region and the lower region of the cutting insert 1 are connected to the upper support protrusions 120 and the lower support protrusions 130 of the insert holder 100 The distribution force F2 received by the cutting insert 1 at the time of machining is appropriately supported so that the cutting insert 1 is prevented from being pushed back to the insert holder 100 and thus the surface roughness of the workpiece is improved It is effective.

In addition, since the cutting insert 1 is prevented from being pushed back by the dispensing force F2 during cutting, the cutting insert 1 can be prevented from being shaken and the cutting insert 1 is not damaged.

A fixing screw fitting hole 112 for fixing the cutting insert 1 to the insert holder 100 through a fixing screw is biased to the upper right side of the insert holder 100 from the insert hole 2 of the cutting insert 1. [ The biasing force of the fixing screw pushes the cutting insert 1 to the upper right side of the insert holder 100 when the cutting insert 1 is coupled to the insert holder 100 with the fixing screw, The main force F1 and the distribution force F2 to be received are suitably supported by the reaction force of the upper support protrusion 120 and the lower support protrusion 130 of the insert holder 100 and at the same time the set screw is inserted into the cutting insert 1 Since the main component force F1 and the distribution force F2 acting on the fastening screw F2 are hardly burdened, the service life of the fastening screw is prolonged and the replacement time of the fastening screw is prolonged.

In the present invention, when the screw thread of the screw of the cutting insert 1 is rotated in the direction in which the main component force F1 acts, that is, in the direction in which the fixation screw receives the rotational force by the main component force F1, (100), it is possible to prevent the fixing screw from being loosened in the insert holder (100) at the time of cutting.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, And additions should be considered as falling within the scope of the claims of the present invention.

1 cutting insert, 100 insert holder

Claims (3)

A cutting tool comprising a cutting insert and an insert holder,
The cutting insert has first to fifth cutting portions, each having a front surface, a rear surface and a cutting edge, formed symmetrically in the circumferential direction and formed with an insert hole in the center,
Wherein the insert holder is formed with a receiving pocket in which the cutting insert is seated at a front end thereof, and an upper support protrusion protruding toward the receiving pocket is formed on the upper side of the receiving pocket, and a lower support protrusion Wherein two support grooves are formed between the upper support protrusions and the lower support protrusions and are accommodated in the cutting portions of the cutting inserts and a fixing screw coupling hole is formed at one point of the receiving pocket,
Wherein the upper support protrusion is formed with a front support portion that is in contact with the front face of the cutting portion of the cutting insert and a rear face support portion that contacts the rear face of the cutting portion of the cutting insert, Wherein a rear surface supporting portion, which is in contact with the rear surface of the cutting portion,
The center of the fixing screw engagement hole of the insert holder with respect to the center of the insert hole of the cutting insert is eccentrically upwardly and rightly eccentrically held in the receiving pocket of the insert holder so that the insert hole and the fixing screw When the fixing screw is engaged with the engaging hole, the fixing screw generates a biasing force to push the cutting insert to the upper right side of the receiving pocket of the insert holder,
Wherein at least a part of the front surface of the second cutting portion is in contact with the front surface supporting portion of the upper supporting protrusion while at least a part of the rear surface of the third cutting portion is in contact with the insert holder in the state that the cutting insert is fixed to the insert holder, Wherein at least a part of the rear surface of the fifth cutting portion abuts against the rear surface supporting portion of the lower supporting projection,
The tangent line (201) of the front surface of the second cutting portion and the front surface supporting portion of the upper supporting protrusion, the rear surface of the fifth cutting portion and the tangent line (203) of the rear surface supporting portion of the lower supporting protrusion Diverging,
The tangent line (201) of the front surface of the second cutting portion and the front surface supporting portion of the upper supporting protrusion, the rear surface of the third cutting portion and the tangent line (202) of the rear surface supporting portion of the upper supporting protrusion Wherein the cutting insert is provided with a cut-away groove. The method according to claim 1,
Wherein a screw thread direction of the screw thread of the insert holder is formed in a direction in which the screw thread is locked in the screw hole when the screw thread is rotated in the direction of the main component of the cutting insert A cutting tool equipped with a cutting edge insert. The method according to claim 1,
Wherein the front supporting portion of the upper supporting protrusion is formed as a curved surface and the rear supporting portion of the upper supporting protrusion and the rear supporting portion of the lower supporting protrusion are formed in a plane,
Wherein the front support portion of the upper support projection is in line contact with the cutting insert and the front face and the rear support portion of the upper support projection and the rear face support of the lower support projection are in contact with the rear surfaces of the cutting insert, Wherein the cutting tool is in surface contact with the cutting insert.

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