CN103920943B - A kind of screw thread process milling cutter - Google Patents

Abstract

The invention discloses a kind of screw thread process milling cutter, including the cutter body that can rotate around rotation axis, described cutter body includes that cutting portion and shank, described cutting portion self-cutting end face are provided with external diameter back taper to shank.This screw thread process milling cutter have cutting initial procedure relatively steadily, can avoid that cutter relieving impact, screw processing quality be high, the advantage of length in service life.

Description

thread milling cutter

technical field

The invention relates to metal cutting, in particular to a milling cutter for thread processing.

Background technique

Compared with traditional thread processing methods, thread milling has great advantages in processing accuracy and processing efficiency, and in the process of CNC milling threads, it is extremely convenient to adjust the thread diameter and has good versatility. At present, thread production in developed countries has widely used milling technology. Thread milling cutters generally use helical interpolation to process threads. When the overhang is long or the rigidity of the processed part is insufficient, due to the influence of the rigidity of the tool or workpiece and the cutting resistance, there will be a phenomenon of giving up the tool, which will cause the processed thread to exist. Taper, and even the phenomenon that the thread plug gauge cannot pass through the gauge; in addition, the cutting teeth of the thread milling cutter will wear unevenly, resulting in a reduction in tool life.

Contents of the invention

The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art, and provide a thread milling cutter with a relatively stable initial cutting process, avoiding the influence of the cutter, high thread processing quality and long service life.

In order to solve the problems of the technologies described above, the present invention adopts the following technical solutions:

A milling cutter for thread processing, comprising a cutter body rotatable around a rotation axis, the cutter body includes a cutting portion and a shank, and the cutting portion is provided with an outer diameter reverse taper from the cutting end surface to the shank.

The back taper value M of the outer diameter back taper gradually increases from the cutting end face to the shank.

The inverted cone with outer diameter is divided into N sections, 2≤N≤4.

From the cutting end face to the shank, the reverse taper value of each segment of the outer diameter reverse taper satisfies: Mn≤Mn+1, 1≤n≤N-1, and M1>0.

The reverse cone value of each segment of the external diameter reverse cone is at least 0.02/100, and the maximum is 1.2/100.

Compared with the prior art, the present invention has the advantages of:

In the threading milling cutter of the present invention, the cutting part is provided with an inverted cone with an outer diameter from the cutting end face to the shank. When the tool approaches the workpiece and starts cutting, the number of teeth that touch the workpiece will be relatively reduced, so that the initial cutting resistance will be relatively small, making the cutting The initial process is relatively stable, and as the interpolation movement proceeds, the number of teeth cut in gradually increases, which reconciles the influence of the tool give-up during processing; moreover, the existence of the reverse taper of the outer diameter reduces the tendency of the positive taper of the processed thread, avoiding It eliminates the phenomenon of non-compliance, improves the quality of thread processing, reduces the wear of cutting teeth, and prolongs the service life of thread processing milling cutters.

Description of drawings

Fig. 1 is a schematic diagram of the front view structure of an embodiment of the present invention.

Fig. 2 is an enlarged structural schematic diagram of the cutting part in Fig. 1 .

Fig. 3 is a schematic structural diagram of another embodiment of the present invention.

Fig. 4 is a wear diagram of the rake face of the thread milling cutter of the present invention.

Fig. 5 is a wear diagram of the rake face of the existing conventional thread processing milling cutter.

Each label in the figure means:

1. Tool body; 2. Cutting part; 3. Shank; 4. Cutting end face; 5. Outer diameter inverted cone.

detailed description

Fig. 1 and Fig. 2 have shown a kind of thread processing milling cutter embodiment of the present invention, and this milling cutter comprises the tool body 1 that can rotate around the axis of rotation, and tool body 1 comprises cutting part 2 and shank part 3, and cutting part 2 is provided with There is a spiral groove chip removal structure, and the cutting part 2 is provided with an outer diameter inverted cone 5 from the cutting end face 4 to the shank part 3. When the tool approaches the workpiece and starts cutting, the number of teeth that touch the workpiece will be relatively reduced compared with the number of conventional threading milling cutters. In this way, the initial cutting resistance will be relatively small, making the initial cutting process relatively stable. As the interpolation movement progresses, the number of teeth cut in will gradually increase, which reconciles the influence of tool give-up during processing and avoids the appearance of taper in the pitch diameter of the thread; and, The existence of the outer diameter reverse taper 5 reduces the positive taper tendency of the processed thread, avoids the phenomenon of not passing through the gauge, improves the thread processing quality, and also reduces the wear of the cutting teeth, prolonging the use of the thread processing milling cutter life.

The outer diameter inverted cone 5 is divided into N sections, 2≤N≤4, from the cutting end face 4 to the shank 3, the inverted cone value of each section of the outer diameter inverted cone 5 satisfies: Mn≤Mn+1, 1≤n≤N- 1, and M1>0, the reverse cone value of each segment of the outer diameter reverse cone 5, the minimum is 0.02/100, and the maximum is 1.2/100. In this embodiment, the total length L of the cutting portion 2 is 11.25mm, and is divided into three sections L1, L2 and L3, wherein L1=L2=4mm, L3=3.25mm, and the reverse cone M1 of the outer diameter of L1 is 0.2～0.3/ 100, L2's outer diameter inverted cone M2 is 0.4~0.5/100, L3's outer diameter inverted cone M3 is 0.6~0.7/100, when the tool approaches the workpiece, the number of teeth of L1 first contacts the workpiece, and then L2 and L3 contact in turn The number of teeth in contact with the workpiece in the initial cutting will be relatively reduced, so that the cutting resistance will be smaller than that of conventional thread milling milling cutters when several teeth contact the workpiece at the same time. The initial process of cutting is relatively smooth.

Fig. 3 shows another embodiment of threading milling cutter of the present invention, this embodiment is basically the same as the previous embodiment, the only difference is that the chip removal groove provided by the cutting part 2 is a straight groove, and the outer diameter is tapered The reverse taper value M of 5 gradually increases from the cutting end face 4 to the shank 3, from 0.02/100 to 0.07/100.

In order to further illustrate that the thread milling cutter of the present invention has the above-mentioned advantages, a comparison experiment is now made between the thread milling cutter of the above-mentioned first embodiment and the existing conventional thread milling cutter.

Processed material: 38MnVS6, hardness 28～32HRC;

Machine tool: TOYODA (horizontal machining center);

Cutting parameters: S=1600r/min, F=500mm/min;

Cooling method: internal cooling, emulsion; tool compensation: the maximum compensation is 0.07mm;

Thread milling cutter diameter: 15.8mm;

Thread to be processed: M14×1.5;

Testing instrument: thread ring gauge M14×1.5-6e, American JOHNSONGAGE middle diameter measuring instrument;

After the two tools were processed at the same time for 160 minutes, the wear value of the rake face of the two thread milling cutters and the quality of the processed thread were measured.

Fig. 4 is a wear diagram of the rake face of the thread milling cutter according to the first embodiment of the present invention, and Fig. 5 is a wear diagram of the rake face of the conventional thread processing milling cutter. From Fig. 4 and Fig. 5, it can be seen that the threading milling cutter of the first embodiment of the present invention is in the extending direction from the end face to the shank, and the wear of the cutting teeth is relatively uniform, and the wear is smaller than that of the existing conventional threading milling cutter . Analyzing the reason, it is that in the process of thread processing, the value of cutter compensation is different. The existing conventional thread processing milling cutter does not have the reverse cone of outer diameter, and the depth of cut of some teeth is relatively deep, resulting in greater wear.

Detecting the processed thread, the thread processing milling cutter of the first embodiment of the present invention processes the thread taper of 0.01mm (the difference between the pitch diameter of the first tooth and the sixth tooth thread), while the conventional thread processing milling cutter processes the thread along the taper of 0.01mm. The cone has reached 0.03mm.

Through the service life test of the thread milling cutter, when the thread milling cutter of the first embodiment of the present invention processes threads for 390 minutes, all cutting edges wear evenly, and the forward taper is 0.015 mm; while the existing conventional thread processing milling cutter processes threads for 210 minutes Shun cone has reached 0.05mm.

It can be seen from the above that the threading milling cutter according to the first embodiment of the present invention is superior to the existing conventional threading milling cutter in terms of thread processing quality and service life.

Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Any person familiar with the art, without departing from the scope of the technical solution of the present invention, can use the technical content disclosed above to make many possible changes and modifications to the technical solution of the present invention, or modify it into an equivalent implementation of equivalent changes example. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention shall fall within the protection scope of the technical solution of the present invention.

Claims (2)

1. A milling cutter for thread processing, comprising a tool body (1) that can rotate around the axis of rotation, the tool body (1) includes a cutting portion (2) and a shank (3), characterized in that: the cutting portion (2) There is an outer diameter inverted cone (5) from the cutting end surface (4) to the shank (3), and the inverted cone value M of the outer diameter inverted cone (5) is from the cutting end surface (4) to the handle (3) ) gradually increases, the outer diameter inverted cone (5) is divided into N sections, 2≤N≤4, from the cutting end face (4) to the shank (3), the outer diameter inverted cone (5) of each section The inverted cone value satisfies: Mn≤Mn+1, 1≤n≤N-1, and M1>0. 2. The threading milling cutter according to claim 1, characterized in that: the reverse taper value of each segment of the outer diameter reverse taper (5) is at least 0.02/100 and at most 1.2/100.