CN100369704C - Indexable Internal Turning Inserts - Google Patents

Abstract

The present invention provides a reversible turning blade for turning inner holes with high precision, which has a basic polygonal shape and comprises an upper surface, a lower surface and a plurality of groups of side walls, wherein the side walls and the upper surface are crossed to form blade cutting edges, and the upper surface forms a front cutter surface at the cutting edges. The present invention is characterized in that two adjacent side walls are connected by a conical surface to form a rear cutter surface; the upper surface, the side walls and a circular arc surface are crossed to form a cutting edge angle; the cutting edges are symmetrically distributed corresponding to the geometric bisector of the cutting edge angle and form a helical line shape, and the top edge is the highest; the center of the top of the cutting edge angle is provided with a groove and a chip cutting groove composed of a spherical lug boss positioned in the groove, wherein the tail part of the spherical lug boss is connected with the upper surface of the blade by a cylindrical surface of which the generatrix forms an included angle theta with the horizontal direction, the bottom of the groove is approximate to an ellipse shape and is level with the bottom of the cutter groove, and an included angle between the side wall and the axis direction of the blade is beta. The reversible turning blade of the present invention has the advantages of sharp cutter tip, controllable chip cutting direction and shape, and smooth chip discharge.

Description

Indexable Internal Turning Inserts

technical field

The invention relates to an indexable inner hole turning insert, in particular to an indexable cutting insert used in inner hole precision turning.

Background technique

The processing of chips in internal hole turning has always been a major problem in machining, especially when processing small-diameter workpieces, chips are difficult to break and discharge, and are easy to wrap around workpieces, tools, and fixtures. The more it accumulates, the easier it is to scratch the processed surface, affect the processing quality, and even hit the blade to cause the blade to chip. Therefore, in the traditional inner hole machining, the operator often has to stop the machine midway to clean up the chips, which seriously affects the machining efficiency and the machining quality of the workpiece. Especially for the precision machining of the inner hole of the workpiece, the problem of chip disposal is more prominent. The curvature of the chips formed by cutting is too large, the flow of chips cannot be controlled or predicted artificially, and the chips are difficult to break. Damage to knives and blades, especially when processing some materials with good plasticity and viscosity, such as stainless steel, alloy materials, and non-ferrous metals. Inner hole turning inserts, such as the patent US005116167A, set grooves and bosses in the edge plane of the insert to meet chip breaking under different cutting depths and feed conditions, but when the groove shape with a closed rear end of the groove is processed The cutting force is large, which has certain limitations on the finishing of the inner hole of the workpiece.

Contents of the invention

In view of the above disadvantages, the present invention provides an indexable turning insert for precision turning of inner holes, which has a sharp tip, controllable chip flow direction and shape, and smooth chip removal.

The indexable inner hole turning insert of the present invention has a polygonal basic shape, including opposite upper and lower surfaces and several groups of side walls connecting the two. The rake face is formed at the center, which is characterized in that: the adjacent two side walls are connected by a conical surface to form a flank face with a relief angle a of 5°-15°, and the upper surface, the side wall and the arc surface intersect to form a cutting edge angle; The cutting edge is distributed symmetrically about the geometric bisector of the cutting edge angle, in the shape of a spatial helix, and the position of the top edge on the geometric bisector of the cutting edge angle is the highest, and the maximum difference h from the symmetrical side edge is 0.02-0.2mm; The chip breaker is composed of a groove and a spherical boss located in the center of the top of the cutting edge angle; the horizontal distance from the intersection point of the front end of the spherical boss and the groove to the top edge is 0.3mm-1.2mm, and the top The vertical distance b from the bottom of the groove is 0.04-0.12mm, and the tail is connected to the upper surface of the blade through the generatrix and the cylindrical surface with an angle θ of 4°-15° in the horizontal direction; The bottom of the groove is flat, and the angle β between the side wall of the groove and the axial direction of the blade is 19°-21°.

The vertical distance d between the bottom of the groove and the top edge is 0.05-0.15 mm, and the radius of the spherical boss is 0.3-0.6 mm.

The optimal values of the included angles β and θ are 20° and 8°.

As a further improvement, in the indexable inner hole turning insert of the present invention, the rake face includes a first rake face and a second rake face, and the included angles with the lower surface are respectively the first rake angle γ and the second rake angle δ , the γ is 5°-10°, and the δ is 8°-15°; the optimal values of γ and δ are 6° and 10°.

The cutting edge of the present invention has a space helical shape and a large relief angle, which enhances the sharpness of the tool tip and avoids interference with the workpiece during processing; the chip breaker composed of grooves and spherical bosses can be used even for difficult-to-machine materials , materials with strong plasticity and viscosity can also effectively guide the flow, curling and breaking of chips, so that the chips generated during inner hole processing flow to one side of the tool regularly, and break into C-shaped chips to be discharged smoothly.

Description of drawings

Fig. 1 is a perspective view of the triangular form of the indexable inner hole turning insert of the present invention;

Fig. 2 is an enlarged top view of the cutting edge angle 6 of Fig. 1;

Fig. 3 is a plane expansion diagram of the K area of the cutting edge angle 6 in Fig. 2;

Fig. 4 is B-B sectional enlarged view among Fig. 2;

Fig. 5 is an enlarged cross-sectional view of C-C in Fig. 2 .

FIG. 6 is a schematic perspective view of FIG. 2 .

Among them: 1-upper surface, 2-lower surface, 3a, 3b-side wall, 4-cutting edge, 4a, 4b-side edge, 4c-top edge, 5-arc surface, 6-cutting edge angle, 7- Groove, 8-spherical boss, 9-chip breaker, 10-sipe groove, 11-first rake face, 12-second rake face, 13-cylindrical face.

Detailed ways

The present invention will be further elaborated below in conjunction with accompanying drawing:

As shown in Figures 1-6, the indexable inner hole turning insert of the present invention has a polygonal basic shape, such as a triangle, including opposite upper and lower surfaces 1, 2 and three sets of side walls 3 connecting the two, The sidewall 3 meets the upper surface 1 to form an insert cutting edge 4 where the upper surface 1 forms a rake face. The cutting edge 4 is distributed symmetrically with respect to the geometric bisector of the cutting edge angle 6, in the shape of a spatial helix, and the top edge 4c located on the geometric bisector of the cutting edge angle is at the highest position, and the maximum difference h between the symmetrical side edges 4a and 4b is 0.02 mm-0.2mm; Adjacent sidewalls 3a and 3b are connected by conical surface 5 to form a flank with a relief angle a of 5°-15°; upper surface 1, sidewall 3 and arc surface 5 intersect to form a cutting edge angle 6. A chip breaker 9 composed of a groove 7 and a spherical boss 8 is designed in the center of the top of the cutting edge angle 6. The horizontal distance c from the intersection point of the front end of the spherical boss 8 and the groove 7 to the top edge 4c is 0.3mm-1.2 mm, the tail is connected to the upper surface 1 of the blade through the cylindrical surface 13, and the angle θ between the generatrix of the cylindrical surface 13 and the horizontal direction is 4°-15°, preferably 8°. The bottom profile of the groove 7 is approximately elliptical and flat with the bottom of the sipe 10, the distance d from the top edge 4c is 0.05mm-0.15mm, and the angle β between the side wall and the direction of the blade axis is 19°-21°, preferably 20°.

In order to make the tip sharp, there are two rake faces: the first rake face 11 and the second rake face 12, and the angles between them and the lower surface 2 are the first rake angle γ and the second rake angle δ, respectively. Its value γ is 5°-10°, preferably 6°, and δ is 8°-15°, preferably 10°.

Because the cutting edge of the present invention is in the shape of a spatial helix, as shown in Figure 3, the blade is sharper, the cutting is lighter and faster, and the possibility of flash generation during cutting can be reduced; the larger relief angle enhances the sharpness of the knife tip and avoids machining Interference with the workpiece when cutting; the chip breaker composed of grooves and spherical bosses, even for difficult-to-machine materials, materials with strong plasticity and viscosity, chips flow out from the rake face during cutting, along the groove 7 The groove wall enters the chip breaker 9 and is pre-formed, the chips continue to flow, and the middle part is lifted by the action of the spherical boss 8, guiding the chips to move along the front cylindrical surface 13 of the spherical boss, thereby effectively guiding the chips to flow regularly It flows to one side of the tool and breaks into a C-shaped chip to be discharged smoothly, which greatly improves the machining accuracy; at the same time, the chip breaker can store a small amount of coolant to cool the cutting edge; the double rake face structure has a sharp margin and can bear greater external pressure , Reduce the friction generated when chips flow.

The indexable inner hole turning insert of the present invention can be serialized, and can be installed on various standard tool holders. When machining small diameter inner holes, cemented carbide and steel-bonded alloy are used, and the effect is better when the shock absorbing tool holder is used.

Claims (5)

1. reversible holes turning insert, has polygonal basic configuration, comprise relative upper and lower surface (1,2) and the some groups of sidewalls (3) that are connected both, sidewall and upper surface intersect formation blade cut sword (4), upper surface locates to form rake face at cutting edge (4), it is characterized in that: adjacent two side (3a, 3b) is 5 °-15 ° back knife face by the continuous formation of taper seat (5) relief angle a; Upper surface, sidewall and taper seat (5) intersect the formation cutting basil (6); Described cutting edge (4) is symmetrically distributed about the cutting basil (6) how much bisectors, is the spatially spiral wire shaped, and top sword (4c) position that is positioned on how much bisectors of the cutting basil is the highest, with the side edge of symmetry (4a, maximum difference h 4b) is 0.02-0.2mm; The cutting basil (6) top center design fluted (7) and be positioned at the chip-breaker (9) that the spherical boss (8) of groove (7) is formed; The intersection point of the front end of described spherical boss (8) and groove (7) is 0.3mm-1.2mm to the horizontal range c of top sword (4c), the vertical range b of top and groove (7) bottom is 0.04-0.12mm, and afterbody is that 4 °-15 ° the face of cylinder (13) links to each other with the upper surface (1) of blade by bus and horizontal direction angle theta; Described groove (7) bottom profile sub-elliptical and equal with the bottom of cutter groove (10), groove (7) sidewall and blade shaft are 19 °-21 ° to angular separation β.

2. reversible holes turning insert as claimed in claim 1 is characterized in that: described groove (7) bottom is 0.05-0.15mm apart from the vertical range d of top sword (4c); The radius of described spherical boss (8) is 0.3-0.6mm.

3. reversible holes turning insert as claimed in claim 2 is characterized in that: described angle β is 20 °, and the θ value is 8 °.

4. reversible holes turning insert as claimed in claim 1, it is characterized in that: described rake face comprises major first face (11) and second rake face (12), be respectively the first anterior angle γ, the second anterior angle δ with the angle of lower surface (2), described γ is that 5 °-10 °, δ are 8 °-15 °.

5. reversible holes turning insert as claimed in claim 4 is characterized in that: described γ is that 6 °, δ are 10 °.

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