CN114083002A

CN114083002A - Machine presss from both sides transposition cutter with weak rigidity shim

Info

Publication number: CN114083002A
Application number: CN202111384898.3A
Authority: CN
Inventors: 苏国胜; 韩智涛; 孙玉晶; 杜劲; 张培荣; 王宝林; 沈学会
Original assignee: Qilu University of Technology
Current assignee: Qilu University of Technology
Priority date: 2021-11-22
Filing date: 2021-11-22
Publication date: 2022-02-25
Anticipated expiration: 2041-11-22
Also published as: CN114083002B

Abstract

The invention belongs to the technical field of metal cutting processing, and particularly relates to a weak-rigidity shim for a mechanically-clamped indexable cutter. This but machine presss from both sides transposition cutter is with weak rigidity shim, including handle of a knife, shim and blade, characterized by: the elastic modulus of the knife pad is 70-510GPa, the knife pad is arranged on the knife handle, the blade is arranged on the knife pad, the knife handle, the knife pad and the blade are fixed together through a clamping bolt, a large round hole and a small round hole are sequentially formed in the middle of the knife pad, and a plurality of deep grooves are formed in the contact surface of the knife pad and the blade. The invention has the beneficial effects that: when the blade is impacted, the elastic shrinkage of the knife pad reduces the response stress peak value of the blade and the rise time of the impulse of impact force, and slows down the gathering and releasing of impact energy on the blade, thereby protecting the blade from impact fracture, reducing the abrasion of the blade and prolonging the service life of the cutter.

Description

Machine presss from both sides transposition cutter with weak rigidity shim

(I) technical field

The invention belongs to the technical field of metal cutting processing, and particularly relates to a weak-rigidity shim for a mechanically-clamped indexable cutter.

(II) background of the invention

The shim is an important part of a mechanically clamped indexable cutter and is arranged below an insert to protect a cutter body (a cutter rod) and determine the position of a cutting edge. In the process of milling or turning intermittently, due to the periodic variation of cutting thickness, the hard particles of the strengthening phase dispersed in the material, defects, the vibration of a machine tool body and the like, the cutting force fluctuates periodically or aperiodically, and force impact and thermal impact are formed on a blade (a cutter). The force and thermal shock can not only increase the abrasion of the cutter, but also easily cause sudden breakage such as edge breakage and peeling of the cutter, particularly the cutter made of brittle and hard materials such as a ceramic cutter and a CBN cutter. The toughness of the cutter material is increased through toughening and reinforcing measures, so that the impact damage resistance of the blade can be improved. But the strength/hardness and toughness of the tool material are contradictory, the toughness of the high strength/hardness material being lower and vice versa. Such as ceramic and CBN tools, are harder than cemented carbide tools, but are less tough than harder alloys, making such tools impractical for use in cutting applications with high impact.

Disclosure of the invention

The invention provides a weak rigidity shim for a mechanically-clamped indexable cutter, which is used for protecting an insert from impact fracture, reducing the abrasion of the insert and prolonging the service life of the cutter in order to make up the defects of the prior art.

The invention is realized by the following technical scheme:

the utility model provides a but machine clamp transposition cutter is with weak rigidity shim, includes handle of a knife, shim and blade, characterized by: the elastic modulus of the knife pad is 70-510GPa, the knife pad is arranged on the knife handle, the blade is arranged on the knife pad, the knife handle, the knife pad and the blade are fixed together through a clamping bolt, a large round hole and a small round hole are sequentially formed in the middle of the knife pad, and a plurality of deep grooves are formed in the contact surface of the knife pad and the blade.

The elastic modulus of the shim is 70-200 GPa.

The deep groove comprises a side groove positioned at the edge of the shim and a strip groove penetrating through the center of the shim.

The size of the shim is 13 multiplied by 3.6 mm.

The diameter of the small round hole is 6mm, the diameter of the large round hole is 8mm, and the depth of the large round hole is 1.8 mm.

The width of limit groove is 2mm, and the degree of depth is 1 mm.

The depth of the strip groove is 0.5mm, and the width of the strip groove is 2-4 mm.

The invention has the beneficial effects that: when the blade is impacted, the elastic shrinkage of the knife pad reduces the response stress peak value of the blade and the rise time of the impulse of impact force, and slows down the gathering and releasing of impact energy on the blade, thereby protecting the blade from impact fracture, reducing the abrasion of the blade and prolonging the service life of the cutter.

(IV) description of the drawings

The invention will be further described with reference to the accompanying drawings.

FIG. 1 is a schematic structural view of the present invention;

FIG. 2 is a schematic top view of a shim according to embodiment 1 of the present invention;

FIG. 3 is a schematic side view of a shim according to embodiment 1 of the present invention;

FIG. 4 is a schematic top view of a shim according to embodiment 2 of the present invention;

FIG. 5 is a schematic side view of a shim according to embodiment 2 of the present invention;

FIG. 6 is a schematic top view of a shim according to embodiment 3 of the present invention;

FIG. 7 is a schematic side view of a shim according to embodiment 3 of the present invention;

FIG. 8 is a schematic top view of a shim according to embodiment 4 of the present invention;

FIG. 9 is a schematic side view of a shim according to embodiment 4 of the present invention;

FIG. 10 is a schematic view of the structure of an experimental work piece used in the present invention;

FIG. 11 is a graph showing the results of an experiment according to the present invention;

FIG. 12 is a graph showing the results of a second experiment according to the present invention;

in the figure, 1 knife handle, 2 knife pads, 3 blades, 4 clamping bolts, 5 large round holes, 6 small round holes, 7 deep grooves, 8 side grooves and 9 grooves.

(V) detailed description of the preferred embodiments

The attached drawing is an embodiment of the invention. The embodiment comprises a hilt 1, a shim 2 and a blade 3, wherein the elastic modulus of the shim 2 is 70-510GPa, the shim 2 is arranged on the hilt 1, the blade 3 is arranged on the shim 2, the hilt 1, the shim 2 and the blade 3 are fixed together through a clamping bolt 4, a large round hole 5 and a small round hole 6 are sequentially formed in the middle of the shim 2, and a plurality of deep grooves 7 are formed in the contact surface of the shim 2 and the blade 3. The elastic modulus of the shim 2 is 70-200 GPa. The deep groove 7 includes a side groove 8 at the edge of the shim 2 and a bar groove 9 extending through the center of the shim 2. The shim 2 was 13X 3.6mm in size. The diameter of the small round hole 6 is 6mm, the diameter of the large round hole 5 is 8mm, and the depth of the large round hole 5 is 1.8 mm. The width of the side groove 8 is 2mm and the depth is 1 mm. The depth of the strip groove 9 is 0.5mm, and the width is 2-4 mm.

Example 1

The contact surface of the shim 2 and the blade 3 is a plane.

Example 2

On the basis of the embodiment 1, the edge is milled inwards, the milling width is 2mm, the milling depth is 1mm, and the boss is formed after machining.

Example 3

On the basis of embodiment 2, the strip grooves 9 with the width of 2mm and the depth of 0.5mm are processed at the positions of two center lines of the boss, and the upper groove and the lower groove are symmetrical, and the left groove and the right groove are symmetrical.

Example 4

On the basis of embodiment 3, the groove depth is not changed, and the groove width is further increased from 2mm to 4 mm.

Experiment 1

1. An N8 aluminum material with the elastic modulus E =70GPa, a TC4 titanium alloy material with the elastic modulus E =110GPa, a 08 steel material with the elastic modulus E =206GPa and a YT14 hard alloy material with the elastic modulus E =510GPa are selected as the base material of the cutter pad 2.

2. The cutter pad 2 with the structure in the embodiment 1 is processed by N8 aluminum, TC4 titanium alloy, 08 steel and YT14 hard alloy materials.

3. The machined N8 aluminum is placed under the insert 3 and assembled with the shank 1 by the clamping bolt 4.

4. Intermittent turning experiments were performed on the assembled tool. The blade 3 is a YG8 hard alloy blade, and the workpiece is 45 steel bar stock. In order to increase the impact effect, the workpiece is provided with a groove. And clamping the assembled cutter and workpiece on a lathe, wherein the rotating speed of a main shaft of the lathe is 140r/min and 180r/min, the feeding amount is 0.175mm/r, the cutting depth is 0.4mm, and the cutting length is 100 m. After the experiment, the cutter breakage was observed.

The results of the experiment are shown in FIG. 11. According to the contact stiffness formula, when the contact area is a fixed value, the contact stiffness is reduced along with the reduction of the elastic modulus of the two contact materials. In the four shim 2 materials used, the elastic moduli are ordered from large to small: the hard alloy is >08 steel > TC4> N8 aluminum, and the matrix rigidity and the contact rigidity of the hard alloy are ranked from large to small: cemented carbide >08 steel > TC4> N8 aluminium. At the spindle rotating speed of 140r/min, only the blade 3 provided with the YT14 hard alloy shim 2 is broken during cutting. When the rotating speed of the main shaft is increased to 180r/min, the impact on the blade 3 during cutting is further increased, except that the blade 3 is broken when the hard alloy blade pad 2 with higher rigidity is used, the blade 3 is also broken when the 08 steel blade pad 2 with the second rigidity is used, and the blade 3 is not broken when the TC4 and the N8 aluminum blade pad 2 with lower rigidity in the four materials are used, which further shows that the blade pad 2 with lower rigidity is favorable for prolonging the service life of the cutter.

Experiment 2

1. The TC4 titanium alloy material was processed into the shim 2 of examples 1, 2, 3, and 4, respectively.

2. The processed TC4 titanium alloy shim 2 is placed below the blade 3 and assembled with the tool holder 1 through the clamping bolt 4.

3. Intermittent turning experiments were performed on the assembled tool. The workpiece material is the same as that of experiment one. And clamping the assembled cutter and workpiece on a lathe, wherein the rotating speed of a main shaft of the lathe is 350r/min, the feed rate is 0.175mm/r, the cutting depth is 0.4mm, and the cutting length is 100 m. After the experiment, the cutter breakage was observed.

The results of the experiment are shown in FIG. 12. According to the contact rigidity formula, the materials of the two contact objects are known, the elastic modulus is a constant value, and the contact rigidity is reduced along with the reduction of the contact area. When the cutter pad 2 with the TC4 titanium alloy cutter pad 2 as the material and four structures is used, the contact areas are sorted from large to small as follows: 1>2>3>4, the corresponding contact stiffness ordering being: 1>2>3> 4. At a spindle rotation speed of 350r/min, the cutter is broken at the blade 3 with the shim 2 of the 1, 2-type structure, but is not broken at the cutting of the blade 3 with the shim 2 of the 3, 4-type structure. The reason is that the material of the shim 2 determines the rigidity of the base body, the contact rigidity is reduced along with the reduction of the contact area, and under the impact caused by the rotation speed of 350r/min, the shim 2 with the 3-type and 4-type structure with lower shim-to-shim contact rigidity has good protection effect on the blade 3 when the blade 3 is impacted, so that the blade 3 is not easy to break.

Claims

1. The utility model provides a but machine clamp transposition cutter is with weak rigidity shim, includes handle of a knife (1), shim (2) and blade (3), characterized by: the elastic modulus of the cutter pad (2) is 70-510GPa, the cutter pad (2) is arranged on the cutter handle (1), the blade (3) is arranged on the cutter pad (2), the cutter handle (1), the cutter pad (2) and the blade (3) are fixed together through a clamping bolt (4), a large round hole (5) and a small round hole (6) are sequentially formed in the middle of the cutter pad (2), and a plurality of deep grooves (7) are formed in the contact surface of the cutter pad (2) and the blade (3).

2. The mechanically clamped indexable tool weakly-rigid shim as set forth in claim 1, wherein: the elastic modulus of the shim (2) is 70-200 GPa.

3. The mechanically clamped indexable tool weakly-rigid shim as set forth in claim 1, wherein: the deep groove (7) comprises a side groove (8) positioned at the edge of the shim (2) and a strip groove (9) penetrating through the center of the shim (2).

4. The mechanically clamped indexable tool weakly-rigid shim as set forth in claim 1, wherein: the size of the shim (2) is 13 multiplied by 3.6 mm.

5. The mechanically clamped indexable tool weakly-rigid shim as set forth in claim 1, wherein: the diameter of the small round hole (6) is 6mm, the diameter of the large round hole (5) is 8mm, and the depth of the large round hole (5) is 1.8 mm.

6. The mechanically clamped indexable tool weakly-rigid shim as set forth in claim 3, wherein: the width of the side groove (8) is 2mm, and the depth is 1 mm.

7. The mechanically clamped indexable tool weakly-rigid shim as set forth in claim 3, wherein: the depth of the strip groove (9) is 0.5mm, and the width is 2-4 mm.