JP2001353602A - Rotary cutting tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently feed the cutting solution to a work cutting point of a circular tip 3 by using the cutting solution as the liquid in a rotary cutting tool in which a spindle assembly 2A formed by inserting a spindle 4 in a circular tip 3 is stored in cartridge case 2B fitted to a tool fitting hole 1a formed in a tool holder 1 so that both ends of the spindle 4 are inserted in a pair of bushes 71 and 72 in the case 2B, and the spindle assembly 2A is pivotably supported by the fluid pressure by feeding the fluid to pockets 7a and 7b for a radial bearing and a thrust bearing formed on the bushes 71 and 72. SOLUTION: An opening 6d facing an end face of the spindle 4 is formed in the cartridge case 2B, and cover members 81 and 82 for guiding the cutting solution flowing through the opening 6d toward a work cutting point of the circular tip 3 are provided outside the cartridge case 2B.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tool for rotatably supporting a circular tip on a tool holder, and pressing a cutting edge portion of an outer periphery of the circular tip against a work so as to receive a circumferential component of the tip due to a cutting reaction force. The present invention relates to a rotary cutting tool that performs cutting while rotating a circular tip by the circumferential component force.

[0002]

2. Description of the Related Art Conventionally, this type of tool has been disclosed in
According to Japanese Patent No. 185903, as shown in FIG. 5, a spindle c to be inserted into a center hole of a circular tip b is attached to a tool holder a, and a radial bearing pocket d is formed on an outer peripheral surface of the spindle c. A thrust bearing pocket e is recessed in the lower thrust receiving surface of the tool holder a which receives the cutting reaction force of the workpiece W, and fluid is formed in these pockets d and e through a passage f formed in the tool holder a. To provide a circular tip b
Is known which is supported by a fluid pressure.

However, according to this method, it is not possible to obtain a sufficient rigidity for supporting the circular tip b against the tilting moment acting on the circular tip b by the cutting reaction force (the moment of tilting the circular tip b downward in FIG. 5). When heavy cutting is performed, the circular tip b is tilted, causing friction of the right side of the upper surface of the circular tip b with the tool holder a and contact of the circular tip b with the support shaft c. As a result, the circular tip does not rotate smoothly, causing uneven wear of the cutting edge on the outer periphery of the tip, resulting in a roughened cutting surface.

As a rotary cutting tool that solves such a problem, the inventor of the present application has disclosed a spindle assembly formed by inserting a spindle member into a center hole of a circular tip, and a spindle mounted in a tool mounting hole formed in a tool holder. A cartridge case capable of storing the assembly, and a pair of bushes for inserting both ends of the spindle member, which are mounted in the cartridge case, are provided with a radial bearing pocket portion recessed on the inner peripheral surface of each bush, Thrust bearing pockets are recessed in the axial inner end surface of each bush, and fluid is supplied to these pockets through passages formed in the tool holder and the cartridge case to support the spindle assembly with fluid pressure. I created something like this. According to this, not only can the tilting moment acting on the circular tip be received by the thrust bearing pocket of each bush, but also the tilting moment can be efficiently reduced by the radial bearing pocket of each bush that is axially separated from the circular tip. As a result, the rigidity of the circular tip against the tilting moment is improved, and the circular tip rotates smoothly without being inclined even in heavy cutting.

[0005]

SUMMARY OF THE INVENTION In the above,
If cutting fluid is used as the fluid, lubrication and cooling of the circular tip are performed with the cutting fluid flowing radially outward from the thrust bearing pocket. However, the cutting fluid flowing radially outward from the thrust bearing pockets is dispersed throughout the entire area of the circular tip, making it impossible to efficiently supply the cutting fluid to the workpiece cutting point of the circular tip. It becomes difficult to ensure sufficient durability.

SUMMARY OF THE INVENTION In view of the foregoing, it is an object of the present invention to provide a rotary cutting tool capable of efficiently supplying a cutting fluid to a work point for cutting a circular tip.

[0007]

Means for Solving the Problems In order to solve the above problems,
The present invention rotatably supports a circular tip on a tool holder, and presses a cutting edge portion of an outer periphery of the circular tip against a work so as to receive a circumferential component of the tip due to a cutting reaction force,
A rotary cutting tool that performs a cutting process while rotating a circular tip by this circumferential component force. A spindle assembly formed by inserting a spindle member into a center hole of the circular tip, and a tool mounting hole formed in a tool holder. Be attached,
A cartridge case capable of storing a spindle assembly, and a pair of bushings mounted in the cartridge case, into which both ends of the spindle member are inserted. A radial bearing pocket portion is formed in the inner peripheral surface of each bush. Thrust bearing pockets are recessed in the axial inner end surface of each bush, and fluid is supplied to these pockets through a passage formed in the tool holder and the cartridge case.
In the one that supports the spindle assembly with fluid pressure, cutting oil is used as the fluid, and an opening facing the end surface of the spindle member is formed in the cartridge case, and the cutting fluid flowing out through the opening is formed outside the cartridge case. A cover member is provided to guide the circular tip toward the workpiece cutting point.

According to the present invention, the cutting fluid flowing axially outward from the pocket for the radial bearing is efficiently supplied to the work cutting point of the circular tip through the opening of the cartridge case and the cover member, and The durability is improved.

In addition, the spindle member is formed hollow, and a radial through hole is formed in a portion of each end of the spindle member located axially inward from a portion facing each of the radial bearing pockets. If formed, about half of the cutting oil supplied to the thrust bearing pocket flows radially inward, and the gap between the inner peripheral surface of the bush and the outer peripheral surface of the spindle member and the through hole And flows into the hollow portion of the spindle member through the opening, and is supplied from the hollow portion to the workpiece cutting point via the opening of the cartridge case and the cover member. Thus, the supply efficiency of the cutting oil to the work cutting point is further improved.

[0010] By the way, after attaching the cover member to the outer surface of the cartridge case with screws or the like, the cartridge case may be inserted into the tool mounting hole and the cartridge case may be bolted to the tool holder. A block which is inserted into the gap between the outer side surface and the inner surface of the tool mounting hole to fasten and fix the cartridge case to the tool mounting hole by a wedge effect is provided, and this block constitutes a cover member. This is advantageous because the work of attaching members is not required.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS. 1 and 2, reference numeral 1 denotes a tool holder 1 attached to a main shaft of a machining center (not shown). A rake face 3a on one side and a flank 3 on the outer peripheral face
A pair of rotary cutting tools 2 and 2 for cutting the inner circumference of the work W with the circular tip 3 having an outer cutting edge portion 3c formed at b.

Each rotary cutting tool 2 includes a spindle assembly 2A in which a spindle member 4 is inserted into a center hole of a circular tip 3 and a spindle assembly 2A such that one side of the circumference of the circular tip 3 is exposed to the outside. Each of the tool mounting holes 1a formed on both sides around the tip of the tool holder 1 near the tip of the tool holder 1.
Each of the rotary cutting tools 2 can be mounted in the cartridge case 2B.

As clearly shown in FIG. 3, the spindle member 4
Is formed with an intermediate flange portion 4a which is in contact with the rake face 3a of the circular tip 3. The annular spacer 5 is externally inserted into the spindle member 4 so that the circular tip 3 is sandwiched between the flange portion 4a. Then, assemble the spindle assembly 2A. The center hole of the circular tip 3 is tapered, and a tapered portion 4b is formed in the spindle member 4 adjacent to the flange portion 4a in the axial direction, and the tapered portion 4b is formed at the center of the circular tip 3. The circular tip 3 can be accurately centered on the spindle member 4 by being fitted in the hole.

The cartridge case 2B has a first and a second one which are divided into two parts in the axial direction of the spindle assembly 2A.
It is composed of halves 6 _and 62 of the pair. Then, the first half 6 _1, the first bushing 7 ₁ end can be inserted to the spindle member 4 projecting from the flange portion 4a axially outward while press-fitted, a second half 6 in ₂ in the axially outward other end a second bushing 7 ₂ can be inserted to the spindle member 4 projecting press-fitted from the spacer 5, both halves 6 _and 62
The signed by bolts 6a as both end portions of the spindle member 4 is inserted into both bushings _71, 7 ₂ houses axially supported spindle assembly 2A in the cartridge case 2B.

Each half 6 ₁ , 6 _{2 of the} cartridge case 2B
The outer surface 6b of the spindle assembly 2A in the axial direction is formed as a flat surface orthogonal to the axial direction. The first block 8 in contact with the first half ₆₁ of the outer surface 6b ₁
When the second block 8 in contact with the second half 6 ₂ outer surface 6b ₂
Preparative provided, after the insertion of the cartridge case 2B in the second half 6 ₂ of the second block 8 the tool attachment hole 1a _2, in a condition bears against the outer surface 6b, the first half ₆₁ outer surface 6b a first block 8 ₁ into the gap between the inner surface of the tool attachment hole 1a so that tightening the bolts 8a. Here, the outer surface of the first block ₈₁ and the tool attachment hole 1a in contact with this
The inner surface of the is tapered, and thus,
According to a first block 8 ₁ of tightening, the cartridge case 2B are fastened with a wedge effect in the tool attachment hole 1a in a state of being sandwiched between _two first and second two blocks _81, 82.
In this fixed state, the circular tip 3 is
Inclined by a predetermined angle α with respect to a plane parallel to the axis of
When the axis of the tool W is made to coincide with the axis of the work W, and the work W and the tool holder 1 are relatively rotated about the axis to perform the inner circumference cutting of the work W, the circular tip 3 is cut by the cutting reaction force. It rotates under the circumferential component force of.

[0016] and wherein each bush 7 _1, 7 ₂ of the pocket portion 7a for the radial bearing on the inner peripheral surface is recessed, and the axially inner end face of the first bushing ₇₁ facing the flange portion 4a, the spacer 5 the second bushing 7 _second axial inner end face and the respective thrust bearing pocket portion 7b to be opposed is recessed into.
Further, by forming an annular groove 7c to the outer circumferential surface of the bushing 7 _1, 7 ₂ to form the pocket portion 7a for a thrust bearing for the radial bearing on the annular groove 7c, and 7b to each bush 7 _1, 7 ₂ The communication is established through the communication holes 7d and 7e. The cutting fluid pump with the passage 1b of the cutting fluid formed in the tool holder 1 from (not shown), each half ₆₁ and 62 through a passage 6c which is formed in _two respective bushings of the cartridge case 2B 7 ₁ ,
7 is supplied to the _second annular groove 7c, the annular groove 7c and the cutting liquid is supplied to each bush 7 _1, 7 pocket portion 7a for ₂ radial bearings and a thrust bearing pocket portion 7b, the spindle assembly 2A these pockets The cutting fluid supplied to the portions 7a and 7b is supported by the bushings 7 ₁ and 7 _{2 in a} floating state by the hydraulic pressure of the cutting fluid. In FIG. 3, the gaps between the bushes 7 ₁ and 7 ₂ and the spindle assembly 2A are widely written, but the actual values of these gaps are more than ten microns.

At the time of cutting the work W, a tilting moment due to the cutting reaction force (a moment of tilting the circular tip 3 downward to the right in FIG. 3) acts on the circular tip 3, and this tilting moment is applied to both the bushings 7 ₁ and 7. pocket portion 7b for ₂ thrust bearing, 7b as well, both bushings 7 _1, 7 ₂ of the radial bearing pockets 7a, receive any 7a. In particular, since the radial bearing pockets 7a, 7a are located at positions separated from the circular tip 3 in the axial direction, the tilting moment can be efficiently received, and the rigidity of the circular tip 3 with respect to the tilting moment increases. Therefore, even in heavy cutting, the circular tip 3 rotates smoothly without tilting, and uneven cutting of the cutting edge portion 3c on the outer periphery of the circular tip 3 is prevented, so that the machinability is improved.

Each bush 7₁, 7_TwoFor thrust bearing
Part of the cutting fluid supplied to the pocket 7b is
Flows radially outwardly from the
The cutting point is reached. However, this alone supplies the cutting point
Insufficient amount of cutting fluid. Therefore, in this embodiment,
Each half 6 of the cartridge case 2B₁, 6_TwoOuter surface 6b
The opening 6d facing each end face of the spindle member 4 is formed
With each block 8 ₁, 8_TwoThrough the opening 6d
The cutting fluid toward the workpiece cutting point of the circular tip 3
Each block 8 is made to function as a cover member.₁,
8_TwoGuide grooves 8b for cutting fluid are recessed on the inner surface of the
Shu 7₁, 7_TwoFrom the radial bearing pocket 7a
The cutting fluid flowing outwardly passes through the opening 6d and the guide groove 8b.
So that it is supplied to the work cutting point of the circular tip 3.
ing.

Further, in this embodiment, the spindle member 4
Is formed in a hollow shape, and a radial through hole 4c is formed in a portion of each end of the spindle member 4 located inward in the axial direction from a portion facing the radial bearing pocket portion 7a. According to this, the bushing 7 _1, 7 ₂ of the cutting fluid flowing from the radial bearing pockets 7a axially inwardly, and the cutting fluid flowing from the pocket portion 7b for the thrust bearing radially inwardly through hole 4c Through the hollow portion 4d of the spindle member 4
And is supplied from the hollow portion 4d to the work cutting point of the circular tip 3 via the opening 6d and the guide groove 8b. When the through hole 4c is not formed, the entire amount of the cutting fluid supplied to the thrust bearing pocket 7b flows outward in the radial direction. Then, the cutting fluid flowing outward in the radial direction is dispersed over the entire area of the circular tip 3, and reaches the work cutting point only partially. On the other hand, if the through hole 4c is formed as in this embodiment, half of the cutting fluid supplied to the thrust bearing pocket 7b passes through the through hole 4c, the hollow portion 4d, the opening 6d, and the guide groove 8b. The cutting fluid is supplied to the work cutting point, and the supply efficiency of the cutting fluid to the work cutting point is improved as much as possible.

In the above embodiment, the cartridge case
First and second halves 6 of the 2B₁, 6_TwoOuter surfaces 6b, 6
b, openings 6d, 6d are formed in the first half 6₁Outside
An opening 6d is formed only on the surface 6b and flows out from the opening 6c.
Cutting fluid to be applied to the first block 8 ₁Guy formed on the inner surface of
Even if it is supplied to the work cutting point through the groove 8b
According to this, according to this, the circular tip 3 is picked up at the work cutting point.
Cutting fluid is intensively supplied from the side 3a.

The embodiment in which the present invention is applied to the rotary cutting tool 2 for cutting the inner circumference of the work W has been described above. As shown in FIG.
The present invention can be similarly applied to the rotary cutting tool 2 for cutting the outer periphery of the work W. The basic structure of the rotary cutting tool 2 is not different from that of the rotary cutting tool 2, and the same members as those described above are denoted by the same reference numerals. Incidentally, as shown in figure 4, the outer end portion of each block _81, 82, the nozzle portion 8c extending bent toward the workpiece cutting point of the circular tip 3
Is formed so that the cutting fluid can be efficiently supplied to the work cutting point.

[0022]

As is apparent from the above description, according to the present invention, the support rigidity of the circular tip with respect to the tilting moment can be increased, the circular tip rotates smoothly even in heavy cutting, and the cutting edge of the outer periphery of the tip can be cut. In addition to preventing uneven wear, the cutting fluid can be efficiently supplied to the work cutting point, and the durability of the circular tip is improved.

[Brief description of the drawings]

FIG. 1 is a side view of a main part of a tool holder on which a tool of the present invention is mounted.

FIG. 2 is a sectional view taken along the line II-II of FIG.

FIG. 3 is an enlarged sectional view of the tool of the present invention.

FIG. 4 is a sectional view of another embodiment of the tool of the present invention.

FIG. 5 is a sectional view of a conventional example.

[Explanation of symbols]

1 the tool holder 1a tool attachment hole 1c passage 2 rotary cutting tool 2A spindle assembly 2B cartridge case 3 circular chip 4 spindle member 4c through hole 4d hollow portion 6 _1, 6 ₂ casing halves (cartridge case components) 6c passage 6d opening 7 _1, 7 ₂ bushing 7a radial bearing pocket 7b thrust bearing pocket portion 8 _1, 8 ₂ blocks (guide member) 8b guide groove for cutting fluid

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Jin Fukumitsu 1-10-1 Shinsayama, Sayama-shi, Saitama F-term (reference) in Honda Engineering Co., Ltd. 3C046 AA13 BB07

Claims (3)

[Claims] 1. A circular tip is rotatably supported by a tool holder, and a cutting edge portion of an outer periphery of the circular tip is pressed against a work so as to receive a component force in a peripheral direction of the tip due to a cutting reaction force. A rotary cutting tool that performs cutting while rotating a circular tip by a component force, and is mounted in a spindle assembly formed by inserting a spindle member into a center hole of the circular tip and a tool mounting hole formed in a tool holder. A cartridge case capable of accommodating a spindle assembly, and a pair of bushings mounted in the cartridge case, into which both ends of the spindle member are inserted, and a radial bearing pocket portion is formed in the inner peripheral surface of each bush. At the same time, thrust bearing pockets are recessed in the axially inner end face of each bush, and these pockets are used for the tool holder and cartridge case. A fluid that is supplied through a passage formed to support the spindle assembly with fluid pressure, wherein cutting fluid is used as the fluid, an opening facing the end face of the spindle member is formed in the cartridge case, and a cartridge case is formed. A rotary cutting tool, comprising: a cover member that guides a cutting fluid flowing out through the opening toward a work cutting point of the circular tip. 2. The spindle member is formed to be hollow, and a radial through hole is formed in a portion of each end of the spindle member located axially inward from a portion facing each of the radial bearing pockets. 2. The method of claim 1, wherein
A rotary cutting tool according to item 1. 3. The cover member is inserted into a gap between an outer surface of the cartridge case and an inner surface of the tool mounting hole, and is configured by a block for fastening the cartridge case to the tool mounting hole by a wedge effect. The rotary cutting tool according to claim 1 or 2, wherein: