阅读说明：本技术 一种精密成型切削刀具及其制备方法 (Precision forming cutting tool and preparation method thereof ) 是由 陈云 李代刚 朱洪 贾喜庆 施金锋 王建云 刘宏 牟仲德 于 2021-08-31 设计创作，主要内容包括：本发明公开了一种精密成型切削刀具及其制备方法,涉及金属切削加工技术领域,其技术方案要点是：其包括上表面、与上表面续接的前刀面、与上表面平行的下表面、位于上表面与下表面之间的侧面；侧面包括连接前刀面和下表面的第一侧面和连接上表面和下表面的第二侧面；第一侧面与前刀面交叉形成的棱线上形成有多个牙形的切削刃；前刀面靠近切削刃还形成有与切削刃形状相似的凹槽,凹槽内壁与前刀面圆弧连接,凹槽的尖部与切削刃的尖部同向。具有减小成型刀具加工过程中的刀-屑接触面积,减小切削力,提升工件表面质量和工件的成型精度的效果。(The invention discloses a precision forming cutting tool and a preparation method thereof, relating to the technical field of metal cutting processing, and the technical scheme is as follows: the cutting tool comprises an upper surface, a rake face connected with the upper surface, a lower surface parallel to the upper surface and a side face positioned between the upper surface and the lower surface; the side surfaces comprise a first side surface connecting the rake surface and the lower surface and a second side surface connecting the upper surface and the lower surface; a plurality of tooth-shaped cutting edges are formed on a ridge formed by the intersection of the first side surface and the front blade surface; the rake face is close to the cutting edge and still is formed with the recess similar with cutting edge shape, and the recess inner wall is connected with the rake face circular arc, and the point portion of recess and the most portion syntropy of cutting edge. The method has the effects of reducing the contact area of the cutter and scraps in the machining process of the forming cutter, reducing cutting force and improving the surface quality of the workpiece and the forming precision of the workpiece.)

1. A precision-formed cutting tool, characterized by: comprises an upper surface (1), a rake face (5) connected with the upper surface (1), a lower surface (2) parallel to the upper surface (1), and a side surface positioned between the upper surface (1) and the lower surface (2); the side surfaces comprise a first side surface (3) which is connected with the rake surface (5) and the lower surface (2) and a second side surface (4) which is connected with the upper surface (1) and the lower surface (2); a plurality of tooth-shaped cutting edges are formed on the ridge formed by the first side surface (3) and the rake surface (5) in a crossed manner; the front knife face (5) is close to the cutting edge and is further provided with a groove (10) similar to the cutting edge in shape, the inner wall of the groove (10) is connected with the arc of the front knife face (5), and the tip of the groove (10) is in the same direction as the tip of the cutting edge.

2. The precision form cutting tool according to claim 1, wherein the cutting edge comprises a corner cutting edge (6) at the tip, a first cutting edge (7) and a second cutting edge (8), and the first cutting edge (7) and the second cutting edge (8) are respectively continuous with two sides of the corner cutting edge (6).

3. The precision form cutting tool of claim 1, wherein:

the distance between the groove (10) and the corner cutting edge (6) is 0.2-1.5 mm.

4. The precision form cutting tool of claim 1, wherein:

the side wall of the groove (10) comprises a first side wall (11) at the tip part of the groove (10) and a second side wall (12) at the edge part of the groove (10); a first inclination angle is formed between the first side wall (11) and the rake face (5), the second side wall (12) is composed of two sections of tangent arcs, and the second side wall (12) is smoothly connected with the rake face (5) and the bottom surfaces of the grooves (10) and the second side wall (12).

5. The precision form cutting tool of claim 1, wherein:

said first angle of inclination is between 55 ° and 85 °; the radius of the circular arc forming the second side wall (12) is 0.05-2 mm.

6. The precision form cutting tool of claim 1, wherein:

the height of the groove (10) is 0.1-1 mm.

7. The precision form cutting tool of claim 1, wherein:

the rake face (5) has a rake angle θ of 0 ° to 15 °.

8. The method of manufacturing a precision-formed cutting tool according to any one of claims 1 to 7, wherein:

(1) preparing a precision die with a cutter corresponding to a formed tooth shape and a front cutter face (5) groove shape, wherein the die consists of a die cavity and an upper punch and a lower punch which are connected with the die;

(2) performing precision pressing and sintering of the product: pressing after the mold is filled, maintaining the pressure for 3-5 seconds, and heating and pressurizing for 20-25 hours;

(3) grinding the upper surface (1) and the lower surface (2) of the cutter: ensuring the flatness of the upper surface and the lower surface of the blade to be within 0.005 mm;

(4) precision grinding of the front face (5) of the tool: using a formed diamond fine grinding wheel with the granularity of 120-200mm to carry out slow feeding grinding;

(5) precision forming and grinding of the first side (3) of the tool: grinding by using a grinding wheel, and ensuring that the grinding precision is within plus or minus 8 minutes of a half angle and the dimensional precision is within 0.01 mm;

(6) precision processing of the cutting edge of the cutter forming tooth: the cutting edge of the blade is provided with a passivation band with the size of 0.01-0.05 mm.

Technical Field

The invention relates to the technical field of metal cutting processing, in particular to a precision forming cutting tool and a preparation method thereof.

Background

Cutting tools are tools used in machining for cutting work, and are basically used for cutting metal materials.

According to the development requirement of the manufacturing industry, multifunctional composite cutters and high-speed and high-efficiency cutters become the mainstream of cutter development. In the face of increasingly difficult materials, the tool industry must improve tool materials, develop new tool materials, and more rational tool configurations. In the forming cutter machining, in order to obtain the precision of the profile of a formed workpiece, a multi-section edge profile of a cutter usually participates in cutting at the same time and forms continuous large chips, a front cutter face is completely surrounded by the chips, so that a large contact area of 'cutter-chip' is formed, the cutting force is increased, and the phenomenon of chip accumulation is generated on the front cutter face in a large area, so that the cutting effect, the surface quality of the workpiece and the forming precision of the workpiece are influenced.

Disclosure of Invention

The invention aims to provide a precision forming cutting tool and a preparation method thereof, and solves the problems that in the processing of the forming cutting tool, the contact area of a tool and a scrap is too large, so that the cutting force is increased, and the surface quality of a workpiece and the forming precision of the workpiece are influenced.

The technical purpose of the invention is realized by the following technical scheme: a precision forming cutting tool comprises an upper surface, a rake face connected with the upper surface, a lower surface parallel to the upper surface and a side surface positioned between the upper surface and the lower surface; the side surfaces comprise a first side surface connecting the rake surface and the lower surface and a second side surface connecting the upper surface and the lower surface; a plurality of tooth-shaped cutting edges are formed on a ridge formed by the intersection of the first side surface and the front blade surface; the rake face is close to the cutting edge and still is formed with the recess similar with cutting edge shape, and the recess inner wall is connected with the rake face circular arc, and the point portion of recess and the most portion syntropy of cutting edge.

The scheme also provides a preparation method of the precision forming cutting tool, which is characterized by comprising the following steps:

(1) preparing a precision die with a cutter correspondingly forming a tooth shape and a rake face groove shape, wherein the die consists of a die cavity and an upper punch and a lower punch which are connected with the die;

(2) performing precision pressing and sintering of the product: pressing after the mold is filled, maintaining the pressure for 3-5 seconds, and heating and pressurizing for 20-25 hours;

(3) grinding the upper surface and the lower surface of the cutter: ensuring the flatness of the upper surface and the lower surface of the blade to be within 0.005 mm;

(4) precision grinding of the front tool face of the tool: using a forming diamond fine grinding wheel with the granularity of 120-200mm for slow feeding grinding;

(5) precision molding and grinding of the first side surface of the cutter: grinding by using a grinding wheel, and ensuring that the grinding precision is within plus or minus 8 minutes of a half angle and the dimensional precision is within 0.01 mm;

(6) precision processing of the cutting edge of the cutter forming tooth: the cutting edge of the blade is provided with a passivation band with the size of 0.01-0.05 mm.

The scheme has the advantages that: 1. an inclination angle is formed between the side surface of the groove and the front cutter surface, and when scrap iron passes through the groove formed in the front cutter surface and close to the edge, the scrap iron has the function of positive rake angle, so that the cutting force is reduced, and the effect of cutting lightly and quickly is achieved; 2. the groove design close to the edge part greatly reduces the problem of large contact area between the scrap iron and the front cutter face when the wide scrap iron is molded and processed, avoids the problem of scrap adhesion between the scrap iron and the front cutter face of the cutter, and reduces the cutting force; 3. the cutter manufacturing process provided by the scheme can not only ensure the precision of product processing, but also remove a surface loose layer caused by direct compression molding of a product, and improve the cutter strength and precision of the edge part of the cutting edge of the front cutter face and the surface quality.

Further, the cutting edge includes a corner cutting edge at the tip, a first cutting edge and a second cutting edge, which are respectively continuous with both sides of the corner cutting edge. The corner cutting edge is in tangent connection with both the first cutting edge and the second cutting edge, and the corner cutting edge is in the same plane with both the first cutting edge and the second cutting edge.

Further, the distance between the groove and the corner cutting edge is 0.2-1.5 mm. The shape of recess corresponds the shape of tooth form, has certain distance between recess and the turning cutting edge, can guarantee cutting edge intensity, the iron fillings that produce in the cutting process can not the rake face of direct contact connection cutting edge, can reach the rake face again through a curled route usually, set up the recess at the rake face apart from cutting chipping sword certain distance, just in time can cushion the discharge when iron fillings reach the rake face, high-speed cutting can be with some far away of interval processing, low-speed cutting then can be with some near of interval processing.

Further, the side wall of the groove comprises a first side wall of the groove tip part and a second side wall of the groove edge part; a first inclination angle is formed between the first side wall and the front tool face, the second side wall is composed of two sections of tangent circular arcs, and the second side wall is connected with the front tool face, the second side wall is connected with the bottom face of the groove in a smooth mode. First lateral wall is the position that iron fillings reachd the rake face and reachd at first, this place sets for certain angle of inclination, the iron fillings that can smooth linking reachd, the setting at angle of inclination also has the function at positive rake angle, can reduce the cutting force, reach the effect of light and fast cutting, iron fillings reachs behind the recess bottom behind the first lateral wall via the second lateral wall discharge again, the second lateral wall has more precipitous slope for first lateral wall, when iron fillings pass through the second lateral wall, the rake face will be kept away from to iron fillings, great slope contained angle has between rake face and the discharged iron fillings, can reduce the area of contact of iron fillings at the rake face, the adhesion of iron fillings at the rake face has also been reduced.

Further, the first oblique angle is 55 to 85 °; the radius of the circular arc forming the second side wall is 0.05-2 mm. The inclined included angle between the first inclined plane and the front tool face is 55-85 degrees, when the cut iron chips pass through, the cutting tool has the function of positive rake angle, reduces cutting force and achieves the effect of light and quick cutting; the two arc radiuses of the second side wall are both 0.05-2mm, and when the iron chips leave through the second side wall, the iron chips are far away from the front cutter face to be discharged, so that the contact area between the iron chips and the front cutter face is reduced, and the adhesion of the iron chips on the front cutter face is reduced.

Further, the height of the groove is 0.1-1 mm. The groove has the function of providing the scrap iron to leave quickly after reaching, and the groove is not too deep and is easy to accumulate the scrap, and is too shallow and is easy to increase the cutting force.

Further, the rake face has a rake angle θ of 0 ° to 15 °. The positive rake angle has the advantages of reducing cutting force and enabling the cutter to be sharper, the cutting edge is sharper when the angle of the rake angle is larger, but the strength of the cutter is reduced, so that the rake angle of the cutter is set to be 0-15 degrees, so that the cutter can be sharp and the strength of the cutter can be guaranteed.

Drawings

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

FIG. 2 is a longitudinal sectional view of a groove in example 1 of the present invention;

FIG. 3 is a partial plan view of a groove in embodiment 1 of the present invention;

FIG. 4 is a schematic structural view of embodiment 4 of the present invention;

FIG. 5 is a plan view of a groove in example 4 of the present invention.

In the figure: 1. an upper surface; 2. a lower surface; 3. a first side surface; 4. a second side surface; 5. a rake face; 6. a corner cutting edge; 7. a first cutting edge; 8. a second cutting edge; 9. clamping holes; 10. a groove; 11. a first side wall; 12. a second side wall.

Detailed Description

The present invention is described in further detail below with reference to figures 1-5.

Example 1

A precision forming cutting tool and a preparation method thereof are disclosed, as shown in fig. 1-3, the precision forming cutting tool comprises an upper surface 1, a lower surface 2 and a side surface positioned between the upper surface 1 and the lower surface 2, the upper surface 1 and the lower surface 2 have the same structure, a clamping hole 9 is processed at the center of the upper surface 1 and the lower surface, a rake face 5 is processed at the edge of the upper surface 1, the rake face 5 and the upper surface 1 are not in the same plane, the front angle theta of the tool is 0 DEG, in the vertical direction, the upper surface 1 is positioned above the rake face 5, and the rake face 5 is connected with the upper surface 1 through a circular arc surface with the radius of 1 mm. The cutting edge is located the crest line that rake face 5 and side cross formed, and the cutting edge is the profile of tooth and quantity has three, and the profile of tooth here is triangle profile of tooth, and each cutting edge all includes the corner cutting edge 6 of tip, is located the first cutting edge 7 and the second cutting edge 8 of corner cutting edge 6 both sides respectively, and first cutting edge 7 and second cutting edge 8 are connected with corner cutting edge 6 homogeneous phase cutting, and three cutting edge is located the coplanar. The front knife face 5 is also provided with a groove 10 with a chip guide function through a grooving machine, the shape requirement matched with the triangular tooth shape is achieved, at the moment, the corner of the processed triangular groove 10 is close to the corner cutting edge 6, and two side parts of the triangular groove 10 are parallel to two side parts of the triangular tooth shape in a overlooking state. The bottom area of the triangular groove 10 is smaller than the top area of the triangular groove 10, the longitudinal section of the triangular groove 10 is in a shape of a trapezoid which is similar to an inverted trapezoid, at the moment, the groove depth of the triangular groove 10 is 0.25mm, the side wall of the triangular groove 10 at the corner is a first side wall 11, the side wall of the triangular groove 10 at the edge is a second side wall 12, the first side wall 11 and the second side wall 12 are smoothly connected with the rake face 5, a first inclination angle is formed between the first side wall 11 and the rake face 5, the first inclination angle is 85 degrees, the scrap iron has a positive rake angle function when passing through the first side wall 11, the cutting force is reduced, the purpose of light cutting is achieved, the second side wall 12 is composed of two circular arcs which are smoothly tangent, the two circular arcs are respectively and smoothly connected with the bottom surface of the groove 10 and the rake face 5, the radius of the circular arcs is 0.1mm, and the cut scrap iron reaches the groove 10 through a certain path after leaving the cutting edge, the distance between the groove 10 and the corner cutting edge 6 is now 0.3 mm.

A method for preparing a precision forming cutting tool comprises the following specific steps:

(1) preparing a precision die with a cutter correspondingly formed with a tooth shape and a rake face 5 groove shape; the die is provided with a die cavity, an upper punch and a lower punch, the shape of the die cavity ensures the outer contour of the cutter and the shape of the formed teeth, and the shape of the upper punch and the lower punch ensures the shape of the grooves 10 on the upper surface and the lower surface of the cutter.

(2) Performing precision pressing and sintering on the product; mounting the die on a press, moving an upper punch and a lower punch after filling, ensuring a certain pressure for pressing, maintaining the pressure for 3-5 seconds, and then pushing out a pressed blank body; and then putting the blank body formed by pressing into a boat, pushing the whole boat into a pressure sintering furnace, heating and pressurizing for 20-25 hours, and taking out the blank after cooling.

(3) Grinding the upper surface 1 and the lower surface 2 of the cutter; and grinding the upper surface and the lower surface of the blade by an upper grinding wheel and a lower grinding wheel through a double-ended grinding machine, and ensuring that the parallelism of the upper surface and the lower surface of the blade is within 0.005mm and the flatness of the upper surface and the lower surface of the blade is within 0.003 mm.

(4) Precisely grinding the front tool face 5 of the tool; the formed diamond fine grinding wheel with the grain size of 120-200mm is used for carrying out the slow feeding grinding of the rake face 5, and simultaneously, the radius of the circular arc surface connected between the rake face 5 and the upper surface 1 is between 0.5 and 3 mm.

(5) Precisely molding and grinding the molding tooth flank of the cutter; and precisely grinding the precisely formed teeth of the blade by a precisely formed grinding wheel, wherein the precision is within plus or minus 8 minutes of a half angle and within 0.01mm of dimensional precision.

(6) Precisely processing the cutting edge of the cutter forming tooth; the cutting edge is strengthened to form a passivation band with the size of 0.01-0.05 mm.

Example 2

The difference from example 1 is that: the rake angle θ of the tool was 7 °, the groove depth of the triangular groove 10 was 0.45mm, the first inclination angle between the first side wall 11 and the rake face 5 was 70 °, the circular arc radius of the second side wall 12 was 1mm, and the distance between the groove 10 and the corner cutting edge 6 was 0.5mm at this time.

Example 3

The difference from example 1 is that: the rake angle θ of the tool was 15 °, the groove depth of the triangular groove 10 was 0.8mm, the first inclination angle between the first side wall 11 and the rake face 5 was 55 °, the circular arc radius of the second side wall 12 was 1.5mm, and the distance between the groove 10 and the corner cutting edge 6 was 0.9mm at this time.

Example 4

The differences from examples 1, 2 and 3 are that: as shown in fig. 4 and 5, the cutting edge is of a trapezoidal shape, the groove 10 formed by grinding the corresponding rake face 5 is trapezoidal in a top view, the trapezoidal groove 10 is arranged close to the cutting edge, and two sides of the trapezoidal groove 10 are close to two sides of the trapezoidal toothThe method is suitable for processing the trapezoidal threads; the buttress thread obtained by processing the buttress cutting edge has stronger axial tension and axial compression load resistance and provides leakage resistance, the corresponding groove 10 is designed into a matched buttress shape, the function of a positive rake angle is also realized during cutting, the cutting force is reduced, and the effect of light and fast cutting is achieved. The contact area of the iron chip rake face was measured using the inserts obtained in examples 1 to 3 and the same type of insert without a groove, and the results showed that: the inserts of examples 1 to 3, which had an average contactable area of the iron chip rake face of about 4 to 6mm²(ii) a The contact area of the iron chip front tool surface of the original blade without the groove of the same type is 7-9mm on average²(ii) a The scheme reduces the contact area of the tool bits by 30 to 43 percent compared with the prior art.

The measurement of the contactable area of the iron chip rake face was carried out on the off-peak type cutting edge insert prepared in example 4 and the same type of insert without a groove, and the results showed that: the insert of example 4 having an average contactable area of the iron chip rake surface of about 11 to 15mm²(ii) a The contact area of the iron chip front tool face of the original blade without the groove of the same type is about 15-18mm on average²(ii) a The scheme reduces the contact area of the tool bits by 16-28% compared with the prior art.

In conclusion, the groove design of the scheme has the advantages that the effect is obvious on the reduction of the contact area of the tool scraps, a good effect is achieved in the actual application, the cutting force can be reduced, and the surface quality of the workpiece and the forming precision of the workpiece are guaranteed.

The present embodiment is only for explaining the present invention, and it is not limited to the present invention, and those skilled in the art can make modifications of the present embodiment without inventive contribution as needed after reading the present specification, but all of them are protected by patent law within the scope of the claims of the present invention.