CN105642986A - Taper and ball-end milling cutter - Google Patents

Abstract

The invention provides a tapered ball end milling cutter, which comprises: a head, a neck connected to the head, and a shank connected to the neck, wherein the head is provided with chip removal grooves for forming a solid portion of the chip flute, and forming a cutting edge at the intersection of the chip flute and the solid portion, wherein the cutting edge is provided with a rake face and a relief face, and the rake face of the cutting edge There is a rake angle in contact with the workpiece, and the flank surface of the cutting edge has two relief angles in contact with the workpiece, which are respectively the first relief angle and the second relief angle. The taper ball end milling cutter of the present invention rationally designs the rake angle and relief angle to ensure the rigidity of the milling cutter while increasing the sharpness of the milling cutter, effectively reducing the possibility of burrs in the milling process; the taper ball end of the present invention is precisely The milling cutter has a long service life and can maintain a good surface roughness when processing aluminum alloy pressure wheels.

Description

A kind of taper ball end milling cutter

technical field

The invention belongs to the technical field of aluminum alloy pressure wheels, and in particular relates to a tapered ball end milling cutter.

Background technique

The integral pressure wheel is the core component of the gas turbine and turbocharger. The pressure wheel is widely used in energy power, aerospace, petrochemical, metallurgy and other industries. It is representative, and its shape is relatively standardized and typical. Channel-like complex parts of . The processing method, processing accuracy and processing surface quality of the aluminum alloy pressure wheel directly affect the aerodynamic performance and mechanical efficiency of the engine, and have a decisive impact on the engine performance. The integral pressure wheel is a typical difficult-to-machine part because of its complex surface and high machining accuracy. At present, the most commonly used material for integral pressure wheels is aluminum alloy.

In order to make the pressure wheel meet the aerodynamic requirements, the blades often adopt a structure with a large twist angle and a rounded root, which puts forward higher requirements for the processing of the pressure wheel. The blades of the pressure wheel must have good surface quality. The precision is generally concentrated on the blade surface and the blade root surface. The surface roughness value should be less than Ra0.8um. Taper ball end milling cutters are often used for processing.

At present, the following defects often exist in the process of finishing the blades of the aluminum alloy pressure wheel: First, the tip of the pressure wheel is thin and has no support, and the rigidity is poor. It is easy to produce vibration marks, resulting in low surface roughness of the pressure wheel, which affects the airflow in and out. Second: The material of the pressure wheel is aluminum alloy. When the front and rear angles of the tapered ball end milling cutter are too small, the cutting edge is not sharp enough, and extrusion occurs during the milling process, which will cause burrs at the entrance and exit of the blade. Adding deburring steps will affect the processing efficiency. Third: The inlet of the pressure wheel runner is a narrow semi-closed space, often in the milling process, vibration marks are generated due to poor chip removal.

Therefore, it is necessary to design a new taper ball end milling cutter for aluminum alloy pressure wheel.

Contents of the invention

The invention provides a tapered ball end milling cutter, which comprises: a head, a neck connected to the head, and a shank connected to the neck, wherein the head is provided with chip removal grooves for forming a solid portion of the chip flute, and forming a cutting edge at the intersection of the chip flute and the solid portion, wherein the cutting edge is provided with a rake face and a relief face, and the rake face of the cutting edge There is a rake angle in contact with the workpiece, and the flank surface of the cutting edge has two relief angles in contact with the workpiece, which are respectively the first relief angle and the second relief angle.

The rake angle of the present invention increases the sharpness of the milling cutter, reduces the elastic deformation when the aluminum chip is cut off and the frictional resistance between the chip and the front when the chip flows out; the first relief angle of the present invention reduces the friction between the flank of the milling cutter and the workpiece; the second Two relief angles ensure the strength of the milling cutter.

Wherein, the rake angle is 8-15°.

Wherein, the first relief angle is 10-15°, and the second relief angle is 28-40°.

Wherein, the second rear corner is provided with a third surface.

The third aspect of the present invention increases the clearance of the ball head flank.

Wherein, the chip removal groove is provided with a chip containing groove.

The inventive chip flute serves to guide the flow of aluminum chips to the transition region of said chip flute.

Wherein, the neck is a tapered section, and its taper is 4-7°.

Wherein, the head is in the shape of a cone, and a positive cone with a core thickness is arranged inside the head.

Wherein, the angle of the positive cone of the core thickness is 2° to 5°.

Wherein, the chip flute is formed on the head with a central axis.

The taper ball end milling cutter of the present invention rationally designs the rake angle and relief angle to ensure the rigidity of the milling cutter and increase the sharpness of the milling cutter, effectively reducing the possibility of burrs in the milling process; the ball end fine milling of the present invention The knife has a long service life and can maintain a good surface roughness when processing aluminum alloy pressure wheels; the ball end milling cutter of the present invention is widely applicable to the finishing machining of aluminum alloy pressure wheel blades of various specifications and brands.

Description of drawings

Fig. 1 is the plan view of taper ball end milling cutter of the present invention;

Fig. 2 is a schematic diagram of dimensioning of the tapered ball end milling cutter shown in Fig. 1;

Fig. 3 is a schematic diagram of the head of the tapered ball end milling cutter shown in Fig. 1;

Fig. 4 is a cross-sectional view of the head shown in Fig. 3 in the A-A direction;

Fig. 5 is a top view of the tapered ball end milling cutter shown in Fig. 1;

Fig. 6 is a cross-sectional view along B-B direction shown in Fig. 5 .

detailed description

The present invention discloses a tapered ball end milling cutter 100 for cutting an aluminum alloy pressure wheel. As shown in FIG. A handle 30 connected to the neck 20 , wherein one end of the neck 20 is connected to the head 10 , and the other end of the neck 20 is connected to the handle 30 .

The head 10 is conical, and the head 10 is provided with a chip flute 11 on a cylinder with a central axis, a solid part 12 for forming the chip flute 11, and a solid part 12 between the chip flute 11 and the solid body. A cutting edge 13 is formed at the intersection of the parts 12, wherein the solid part 12 is also called a back; the cutting edge 13 is provided with a rake face and a relief face.

Please refer to Fig. 2, the diameter of the head 1 of the milling cutter is d1, and d1 is 1-6 mm; the blade length of the ball-end fine milling cutter 100 is L1, and L1 is designed according to the depth of the processed pressure wheel blade , generally 3 to 5 mm longer than the blade depth. The neck 20 is a tapered section, and its taper is θ, which is selected according to the number and size of the blades of the pressure wheel. The taper θ is generally designed to be 4-7°, which can prevent the ball-end fine milling cutter 100 from interfering with the pressure during processing. Wheel, also increased the rigidity of this ball end milling cutter 100 simultaneously. The diameter of the shank 30 is d3, and its direct d3 is generally determined by the blade length L1 and the taper θ. In special cases, it can be designed according to actual processing requirements; the length of the shank 30 is L2, and L2 is based on the standard DIN6535-HA design. The total length L3 of the ball end milling cutter 100 is the sum of the lengths of the head 11 , the neck 21 and the shank 30 .

Please refer to FIG. 3 and FIG. 4 , the chip flute 11 is provided with a chip flute 111 , and the chip flute 111 is used to guide aluminum chips to flow to the transition area of the chip flute 11 .

The rake angle δ is the angle at which the rake face of the cutting edge 13 is in contact with the workpiece, and the rake angle δ is 8-15°. The rake angle δ increases the sharpness of the ball end milling cutter 100 and reduces aluminum chips being cut off. Elastic deformation during chip flow and frictional resistance with the front when chips flow out. The reasonable design of the rake angle and relief angle of the ball end milling cutter 100 ensures the rigidity of the milling cutter and increases the sharpness of the milling cutter, effectively reducing the possibility of burrs in the milling process.

The flank of the cutting edge 13 has two edges in contact with the workpiece, and has two relief angles: a first relief angle α and a second relief angle β. Wherein, the first relief angle α is 10-15°, and the first relief angle α can reduce the friction between the flank face of the ball end milling cutter 100 and the workpiece; the second relief angle β is 28-40°, This second relief angle β ensures the strength of the present ball end milling cutter 100 . In order to prevent the contact between the ball head and the peripheral edge from interfering during machining, a third surface 15 is provided on the second relief angle β, and the third surface 15 increases the clearance of the ball head flank. The radius 16 of the ball head is designed according to the space between the blades of the pressure wheel and the quality requirements of the inner surface of the flow channel, and is generally designed as R0.5-R3.

The angles of the rake angle and the rear angle can be adjusted accordingly according to the aluminum alloy material of the pressure wheel to be processed.

Please refer to Figures 5 and 6, the head 10 is provided with a core thickness positive cone ε, ε is 2 to 5°, which not only ensures the rigidity of the cutter, but also improves the chip removal ability and reduces the blade root entrance. And the possibility of vibration pattern at the tip of the blade, which in turn increases the roughness of the surface of the blade and the surface of the blade root. The core thickness positive taper ε is adjusted accordingly according to the material of the pressure wheel to be processed, the surface quality requirements, the taper of the ball end milling cutter 100 and the milling allowance.

The taper ball end milling cutter of the present invention rationally designs the rake angle and relief angle to ensure the rigidity of the milling cutter and increase the sharpness of the milling cutter, effectively reducing the possibility of burrs in the milling process; the ball end fine milling of the present invention The knife has a long service life and can maintain a good surface roughness when processing aluminum alloy pressure wheels; the ball end milling cutter of the present invention is widely applicable to the finishing machining of aluminum alloy pressure wheel blades of various specifications and brands.

The specific embodiments of the present invention have been described in detail above, but the contents are only typical embodiments of the present invention and cannot be considered as limiting the implementation scope of the present invention. All equal changes and improvements made according to the application scope of the present invention shall still belong to the scope covered by the patent of the present invention.

Claims (9)

1. A taper ball end milling cutter, characterized in that it comprises: a head, a neck connected to the head, and a shank connected to the neck, wherein the head is provided with chip removal grooves , a solid part for forming the chip flute, and a cutting edge formed at the intersection of the chip flute and the solid part, wherein the cutting edge is provided with a rake face and a relief face, and the cutting edge The rake surface has a rake angle in contact with the workpiece, and the flank surface of the cutting edge has two relief angles in contact with the workpiece, which are respectively the first relief angle and the second relief angle. 2. The tapered ball end milling cutter according to claim 1, characterized in that: the rake angle is 8-15°. 3. The tapered ball end milling cutter according to claim 1, characterized in that: the first relief angle is 10-15°, and the second relief angle is 28-40°. 4. The tapered ball end milling cutter according to claim 1 or 3, wherein a third surface is provided on the second relief angle. 5. The tapered ball end milling cutter according to claim 1, characterized in that: said chip removal groove is provided with a chip containing groove. 6. The tapered ball end milling cutter according to claim 1, characterized in that: the neck is a tapered section with a taper of 4-7°. 7. The tapered ball end milling cutter according to claim 1, characterized in that: the head is in the shape of a cone, and a positive cone with a core thickness is provided inside the head. 8. The tapered ball end milling cutter according to claim 7, characterized in that: the angle of the core thickness forward taper is 2-5°. 9. The tapered ball end milling cutter according to claim 1, characterized in that: the chip removal groove is formed on the head with a central axis.