Tooth milling cutter structure

Abstract

The utility model provides a tooth milling cutter structure, which can reduce mutual interference with a tooth groove surface of an internal thread tooth by virtue of an upward inclination angle of a cutter back strip, and can avoid contact friction with the tooth groove surface of the internal thread tooth by virtue of a downward inclination angle, so that the cutting power loss is reduced, the abrasion of a blade body is reduced, and the service life of the blade body is prolonged. The service life of the blade is prolonged; and moreover, the worn blade can be simply replaced by disassembling the bolt piece through the working end of the cutter handle, and the cutter handle can be repeatedly used, so that the thread tapping processing cost or expense is reduced.

Description

Technical Field

[0001] The utility model relates to a thread milling cutter structure which is used for internal thread thread cutting. The blade body of the blade does not interfere with and rub against the tooth groove surface, the blade can be easily replaced when worn, and the handle can be reused. Background Art

[0002] After heat treatment, steel workpieces become hard. If you want to open internal thread holes on hard workpieces after heat treatment, you can use an end mill to drill holes on the workpiece first, but it is difficult to directly use a screw tap to tap the drilled holes. The general practice is to use electrical discharge machining to discharge tap the drilled holes, but electrical discharge tapping is time-consuming and labor-intensive, and the processing cost is very high, so you can only use a milling cutter to drill and tap the holes. Although tapping with a milling cutter helps improve the tapping processing efficiency, there is still a problem of excessive tool wear rate.

[0003] Conventional milling cutters are usually made of tungsten steel alloy rods. Due to the hardness of the rods, the processing methods for forming them are greatly limited, such as Figure 1 , Figure 2 , Figure 3 The conventional thread milling cutter 10 shown in the figure has a blade working end 12 integrally formed at one end of a handle 11. The blade working end 12 has a plurality of blade portions 13 arranged in a ring around the axis of the handle 11. Each blade portion 13 is composed of a plurality of blade bodies 14 arranged in parallel from bottom to top according to the pitch specification of the threaded thread. Each blade body 14 has a V-shaped cross section and a blade back strip 140 horizontally surrounding the axis of the handle as the center, and the two ends of the blade back strip 140 each have a V-shaped blade surface 141 corresponding to the horizontal direction; as shown in FIG. Figure 4 When a conventional milling cutter 10 is mounted on a rotary chuck of a milling machine and used to process an internal thread 30 on a bore 21 of a hard material workpiece 20, as shown in FIG. Figure 5 , 6 Since the horizontal arc body of the blade back strip 140 horizontally surrounded by the blade body 14 and the spiral line 31 of the cut internal thread tooth 30 have an interference angle α, an interference point 32 is formed, and the horizontal arc body curve surface of the blade back strip 140 is too close to the groove surface of the internal thread tooth 30, and a large range of friction contact surface 32 is formed. Therefore, when the conventional milling cutter 10 is used for tapping, in addition to a large power loss, the blade body 14 and the screw groove are excessively frictional and easy to wear too quickly. Obviously, it is difficult to overcome the problem of excessive tool wear rate, such as Figure 1 In particular, the blade 13 of the conventional milling cutter 10 is made of high-priced steel together with the handle 11. As long as the blade body 14 is worn, the entire tool needs to be discarded. This is another major reason for the high tool cost in the tapping process of hard workpieces. Utility Model Content

[0004] The main purpose of the utility model is to provide a milling cutter structure.

[0005] The utility model provides a milling cutter structure, which is characterized by comprising:

[0006] A tool handle is a metal round rod having a clamping end and a working end, wherein the clamping end is used to be clamped on a rotary chuck of a milling machine for use; a U-shaped clip slot is formed on the end surface of the working end axially toward the clamping end, and at least one bolt hole is radially provided on the working end of the clip slot;

[0007] A blade is a high-hardness steel plate block, and its two side panels are provided with a relative number of through holes relative to the bolt hole on the working end of the handle, each of which is bolted through the through hole by a bolt on the bolt hole to fix the blade in the clip groove; and at least one blade body is formed on the front and rear end surfaces between the two side panels, which radially extends out of the clip groove, and the two ends of the blade body are flush with the two side panels and have a V-shaped blade front and a V-shaped blade back, and a blade back strip with a V-shaped cross section is provided between the blade front and the blade back, and the blade back strip connects the blade front and the blade back in an upward and downward manner, and the blade back strip forms an angle of at least 1 degree with the horizontal line of the cutting angle of the blade front and has an upward inclination angle, and the blade back strip forms an angle of at least 2 degrees with the vertical line of the blade front and has a downward inclination angle.

[0008] In the milling cutter structure, the tool handle is formed by a steel metal round rod body to form the clamping end and the working end.

[0009] The milling cutter structure, wherein the tool handle is a steel metal round rod in the shape of a stepped rod, having a clamping end with a larger circular diameter and a working end with a smaller circular diameter.

[0010] The milling cutter structure is characterized in that a plurality of blade bodies are correspondingly formed on the front and rear end surfaces of the two side panels of the blade and are arranged from bottom to top, and the plurality of blade bodies are arranged in parallel at equal intervals on the end surfaces with a pitch of a predetermined internal thread tapping as the spacing.

[0011] The milling cutter structure is characterized in that the blade is fixed in the clip notch, the bottom between the two side panels of the blade has a plate bottom end, the blade body is formed on the edge surface from the plate bottom end, and the plate bottom end protrudes from the clip notch.

[0012] In the milling cutter structure, the upward inclination angle of the blade back strip is between 4.6 degrees ± 2 degrees.

[0013] In the milling cutter structure, the downward bevel angle of the blade back strip is between 10 degrees ± 5 degrees.

[0014] The milling cutter structure is described, wherein the blade is fixed in the notch of the clip, and the end between the two side plates of the blade has at least one hole-cutting tool body portion, and the hole-cutting tool body portion is formed with an inclined back surface tangent to the one side plate surface to form a hole-cutting blade, and the blade body is formed on the edge surface by one side of the hole-cutting blade, and the hole-cutting blade protrudes from the notch of the clip.

[0015] The milling cutter is mounted on a rotary chuck of a milling machine and is used for processing internal threads on a drilled hole of a high-hardness workpiece; the self-rotating milling cutter enters the drilled hole in a spiral motion trajectory, that is, the milling cutter can enter and exit the drilled hole more than once for processing reciprocating strokes, and the blade on the working end of the tool handle mills and cuts the internal threads on the hole wall of the drilled hole; during the process of the blade body of the blade milling and rotating the hole wall of the drilled hole, the upward inclination angle of the blade back strip can reduce the mutual interference with the tooth groove surface of the internal thread, and the downward inclination angle can avoid contact and friction with the tooth groove surface of the internal thread, while reducing the cutting power loss, the wear of the blade body is reduced, and the service life of the blade is increased; and the bolt at the working end of the tool handle can be disassembled to easily replace the worn blade, and the tool handle can also be reused, thereby reducing the cost or expense of thread tapping processing.

[0016] The tool handle is formed of a common steel metal round rod to form the clamping end and the working end. The tool handle does not require the same grade of high-hardness tungsten steel as the blade, which can reduce the material cost of the milling cutter.

[0017] Among them, the tool handle is a steel metal round rod in the shape of a stepped rod, having a clamping end with a larger circular diameter and a working end with a smaller circular diameter; by forming a step difference in the shape of a stepped rod between the clamping end and the working end, the blade on the working end can reduce shaking or vibration during the internal thread milling process.

[0018] Among them, on the front and rear end surfaces of the two side plates of the blade, a plurality of blade bodies are correspondingly formed and arranged from bottom to top, and the plurality of blade bodies are arranged in parallel with each other at a pitch with a predetermined pitch for tapping the internal thread as a spacing; when the blade enters the drilled hole of the workpiece and performs tapping and milling of the internal thread on the hole wall, except for the first blade body used to mill the groove of the internal thread on the hole wall, the other blade bodies can trim the groove surface in the cut internal thread.

[0019] Among them, the blade is fixed in the notch of the clip, and the bottom between the two side plate surfaces of the blade has a plate bottom end. The blade body is formed from the plate bottom end on the edge surface, and the plate bottom end slightly protrudes from the notch of the clip; when the blade of the milling cutter is used for tapping of the internal thread teeth of the workpiece before or after the tapping is completed, the blade body connected to the bottom end of the plate can directly carry out and complete the cutting of the chamfer at the working drill hole; and when tapping the blind hole, the tooth pattern can reach the blind hole depth limit.

[0020] Among them, the upward inclination angle of the blade back strip is 4.6 degrees ± 2 degrees with the cutting angle horizontal line of the front of the blade; so that the blade can be used for conventional milling and tapping processing of internal threads with different pitches, and the blade back strip does not interfere with the groove surface of the internal thread teeth.

[0021] The downward slope angle of the blade back strip is 10 degrees ± 5 degrees with the vertical line on the front of the blade, so that the cutting angle on the front of the blade has both cutting sharpness and strength.

[0022] Among them, the blade is fixed in the notch of the clip, and the end between the two side plates of the blade has at least one hole-cutting tool body part. The hole-cutting tool body part forms a hole-cutting edge with an inclined back side tangent to the one side plate surface. The blade body is formed on the edge surface by one side of the hole-cutting edge, and the hole-cutting edge slightly protrudes from the notch of the clip; the blade of the milling cutter is used for tapping the blind hole of the workpiece. When the depth of the blind hole is not enough or is not in place, the hole-cutting edge of the hole-cutting tool body part will perform repair milling cutting on the bottom of the hole depth of the blind hole before the blade body touches the bottom, which can avoid the blade body from being damaged or broken by touching the bottom. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a stereoscopic diagram of the structure of a commonly used milling cutter.

[0024] Figure 2 It is a front view plan view of a commonly used milling cutter structure.

[0025] Figure 3 yes Figure 2 A-A section view.

[0026] Figure 4 It is a schematic diagram of the cross-section state when a milling cutter is used for tapping.

[0027] Figure 5 It is a plane diagram of the cross-section state of the workpiece when tapping with a conventional milling cutter.

[0028] Figure 6 It is a schematic diagram of the material removal state of the blade body when using a conventional milling cutter for tapping.

[0029] Figure 7 It is a three-dimensional diagram of the structure combination of the milling cutter of the utility model.

[0030] Figure 8 It is an exploded stereoscopic diagram of the structure of the milling cutter of the utility model.

[0031] Fig. 9 It is a front plan view schematic diagram of the milling cutter structure of the utility model.

[0032] Fig.10 The utility model is a schematic plan view of the bottom structure of the milling cutter.

[0033] Fig.11 The utility model is a three-dimensional schematic diagram of a cross-section state of a workpiece when the milling cutter is tapping.

[0034] Fig.12 The utility model is a plane schematic diagram of the cross-sectional state of a workpiece when the milling cutter is tapping.

[0035] Fig.13 The utility model is a schematic diagram of the material removal state of the blade body of the milling cutter during tapping.

[0036] Fig.14 It is an exploded stereoscopic view of the milling cutter structure of another embodiment of the utility model.

[0037] Fig.15 It is a three-dimensional diagram of the milling cutter structure assembly of another embodiment of the utility model.

[0038] Fig.16 It is a schematic diagram of blind hole tapping in another embodiment of the utility model.

[0039] Description of reference numerals: milling cutter 10; tool handle 11; blade working end 12; blade portion 13; blade body 14; blade back strip 140; blade surface 141; workpiece 20; drill hole 21; blind hole 21A; internal thread 30; helix 31; interference angle α; interference point 32; friction contact surface 33; milling cutter 40, 40A; tool handle 50; clamping end 60; working end 70; clip notch 71; bolt hole 72; Blades 80, 80A; side panel surface 81; side panel surfaces 81A, 81B; perforation 82; edge 83; blade body 84, 84A; front of blade 840A; back of blade 840B; back strip 841; spacing 842; upward inclination angle β; downward inclination angle γ; cutting angle 85; horizontal line 86; vertical line 87; bottom end of plate 88; hole-cutting blade body 89; oblique back side 890; hole-cutting blade 891; bolt 90. DETAILED DESCRIPTION

[0040] In order to achieve the above-mentioned purpose, the present invention specifically lists the preferred embodiments and describes them in detail with the accompanying drawings as follows:

[0041] The utility model provides a milling cutter structure, such as Figure 7 , Figure 8 , Fig. 9 , Fig.10 As shown, a milling cutter 40 includes:

[0042] A tool handle 50 is a metal round rod having a clamping end 60 and a working end 70. The clamping end 60 is used to be clamped on a rotary chuck (not shown) of a milling machine to use the working end 70. The end surface of the working end 70 is formed with a U-shaped clip notch 71 axially toward the clamping end 60. The working end 70 of the clip notch 71 is radially provided with at least one bolt hole 72.

[0043] A blade 80 is a plate block of high-hardness steel (such as tungsten steel alloy steel), formed by wire cutting processing, and its two side plate surfaces 81 are provided with a corresponding number of through holes 82 relative to the bolt hole 72 on the working end 70 of the handle 50, each of which is bolted through a bolt 90 on the bolt hole 72 to fix the blade 80 in the clip slot 71; and at least one blade body 84 is formed on the surface of the front and rear ends 83 between the two side plate surfaces 81, extending radially out of the clip slot 71, and the two ends of the blade body 84 are flush with the two side plate surfaces. The side plate surface 81 has a V-shaped front blade 840A and a V-shaped back blade 840B, and a V-shaped cross-section blade back strip 841 is provided between the front blade 840A and the back blade 840B. The blade back strip 841 is upwardly inclined and downwardly inclined, connecting the front blade 840A and the back blade 840B. The upward inclination angle β of the blade back strip 841 is at least 1 degree with the horizontal line 86 of the cutting angle 85 of the front blade 840A, and the downward inclination angle γ is at least 2 degrees with the vertical line 87 of the front blade 840A.

[0044] like Fig.11 As shown, the milling cutter 40 is mounted on a rotary chuck of a milling machine (not shown) and is used to process an internal thread 30 on a bore hole 21 of a high-hardness workpiece 20 (a steel workpiece after heat treatment); the self-rotating milling cutter 40 enters the bore hole 21 in a spiral motion trajectory, that is, the milling cutter 40 can enter and exit the bore hole 21 more than once (the number of processing strokes is determined by the depth of the tapping groove in one stroke), and the blade 80 on the working end 70 of the tool handle 50 mills and cuts the internal thread 30 on the hole wall of the bore hole 21; Fig.12 , Fig.13 As shown, during the milling and turning process of the blade body 84 of the blade 80 on the hole wall of the drill hole 21, the upward inclination angle β of the blade back strip 841 (see Fig. 9 ) can reduce or eliminate the mutual interference with the groove surface of the internal thread tooth 30, and the downward bevel angle γ (see Fig.10) can avoid contact and friction with the groove surface of the internal thread tooth 30, while reducing the cutting power (milling machine power) loss, through the wear of the blade body 84 is reduced, the service life of the blade 80 is increased; and, as Figure 8 As shown, by disassembling the bolt 90 at the working end 70 of the tool handle 50, the worn blade 80 can be easily replaced, and the tool handle 50 can also be reused, thereby reducing the cost or fee of thread tapping processing.

[0045] According to the above embodiment, Figure 7 , Figure 8 As shown, the tool handle 50 is a metal round rod made of ordinary steel (such as medium carbon steel grade steel) to form the clamping end 60 and the working end 70. By forming the tool handle 50, it is not necessary to use high-hardness steel of the same grade as the blade 80, which can reduce the material cost of the milling cutter 40.

[0046] According to the above embodiment, Figure 7 , Figure 8 As shown, the handle 50 is a steel metal round rod in the shape of a step rod, having a clamping end 60 with a larger diameter and a working end 70 with a smaller diameter; a step difference in the shape of a step rod is formed by the clamping end 60 and the working end 70, such as Fig.11 As shown, the blade 80 on the working end 70 can reduce shaking or vibration during the milling process of the internal thread 30.

[0047] According to the above embodiment, Figure 7 , Figure 8 , Fig. 9 As shown, the front and rear surfaces of the two side ends 83 of the two side plate surfaces 81 of the blade 80 are formed with a plurality of blade bodies 84, 84A arranged from bottom to top, and the plurality of blade bodies 84, 84A are arranged parallel to each other at a pitch 842 with a predetermined pitch when tapping the internal thread teeth as a spacing; as shown Fig.11 , Fig.12 As shown, when the blade 80 enters the drill hole 21 of the workpiece 20 and taps and mills the internal thread teeth 30 on the hole wall, except for the first (frontmost) blade body 84 used to mill the tooth groove of the internal thread teeth 30 on the hole wall, the other (back row) blade bodies 84A can trim the groove surface in the cut internal thread teeth 30.

[0048] According to the above embodiment, preferably, Figure 7 , Figure 8 , Fig. 9As shown, the blade 80 is fixed in the clip notch 71, and the bottom between the two side plate surfaces 81 of the blade 80 has a plate bottom end 88, and the blade body 84 is formed on the surface of the edge end 83 starting from the plate bottom end 88, and the plate bottom end 88 slightly protrudes from the clip notch 71 in the axial direction; Fig.11 , Fig.12 As shown, when the blade 80 of the milling cutter 40 is used for cutting the internal thread teeth 30 of the workpiece 20 before or after the tapping is completed, the blade body 84 connected to the bottom end 88 of the plate can directly perform and complete the cutting of the chamfer at the opening of the drill hole 21 of the workpiece 20 (not shown); and when tapping a blind hole (not shown), the tooth pattern can reach the blind hole depth limit.

[0049] According to the above embodiment, preferably, Fig. 9 As shown, the upward inclination angle β of the blade back strip 841 is 4.6 degrees ± 2 degrees with the horizontal line 86 of the cutting angle 85 of the front side of the blade 840A; Fig.12 As shown, the blade 80 is used for conventional milling and tapping of internal threads with different pitches, and the blade back strip 841 does not interfere with the groove surface of the internal thread.

[0050] According to the above embodiment, preferably, Fig.14 , Fig.15 As shown, the blade 80A is fixed in the clip notch 71, and the end between the two side panels 81A and 81B of the blade 80A has at least one hole-cutting blade body 89, and the hole-cutting blade body 89 is formed by an inclined back surface 890 tangent to the side panel 81A to form a hole-cutting blade 891, and the blade body 84 is formed on the surface of the edge end 83 by one side of the hole-cutting blade 891, and the hole-cutting blade 891 slightly protrudes from the clip notch 71; Fig.16 As shown, the blade 80A of the milling cutter 40A is used for tapping the blind hole 21A of the workpiece 20. When the depth of the blind hole 21A is insufficient or is not in place, before the blade body 84 touches the bottom, the cutting edge 891 of the cutting tool body 89 will perform repair milling cutting on the bottom of the blind hole 21A, thereby preventing the blade body 84 from being damaged or broken by touching the bottom.

[0051] According to the above embodiment, preferably, Fig.10 As shown, the downward angle γ of the blade back strip 841 is 10 degrees ± 5 degrees with the vertical line 87 of the front side of the blade 840A; Fig.10 , Fig.13 As shown, the cutting corner 85 of the front side 840A of the blade has both cutting sharpness and strength.

[0052] The above description is only illustrative and not restrictive of the present invention. A person skilled in the art will understand that many modifications, changes or equivalents may be made without departing from the spirit and scope of the attached description of the present invention, but all of them will fall within the protection scope of the present invention.

Claims

1. A milling cutter structure, characterized in that: include: A tool handle is a metal round rod having a clamping end and a working end, wherein the clamping end is used to be clamped on a rotary chuck of a milling machine for use; a U-shaped clip slot is formed on the end surface of the working end axially toward the clamping end, and at least one bolt hole is radially provided on the working end of the clip slot; A blade is a high-hardness steel plate block, and its two side panels are provided with a relative number of through holes relative to the bolt hole on the working end of the handle, each of which is bolted through the through hole by a bolt on the bolt hole to fix the blade in the clip groove; and at least one blade body is formed on the front and rear end surfaces between the two side panels, which radially extends out of the clip groove, and the two ends of the blade body are flush with the two side panels and have a V-shaped blade front and a V-shaped blade back, and a blade back strip with a V-shaped cross section is provided between the blade front and the blade back, and the blade back strip connects the blade front and the blade back in an upward and downward manner, and the blade back strip forms an angle of at least 1 degree with the horizontal line of the cutting angle of the blade front and has an upward inclination angle, and the blade back strip forms an angle of at least 2 degrees with the vertical line of the blade front and has a downward inclination angle.

2. The milling cutter structure according to claim 1, characterized in that: The knife handle is formed of a steel metal round rod body to form the clamping end and the working end.

3. The milling cutter structure according to claim 1, characterized in that: The knife handle is a steel metal round rod in a stepped rod shape, and is provided with a clamping end with a larger circular diameter and a working end with a smaller circular diameter.

4. The milling cutter structure according to claim 1, characterized in that: A plurality of blade bodies are correspondingly formed on the front and rear end surfaces of the two side plates of the blade and are arranged from bottom to top, and the plurality of blade bodies are arranged in parallel and at equal intervals on the end surfaces with a predetermined pitch for tapping the internal thread as the spacing.

5. The milling cutter structure according to claim 1, characterized in that: The blade is fixed in the clip notch, and a plate bottom end is provided at the bottom between the two side plate surfaces of the blade. The blade body is formed on the edge surface from the plate bottom end, and the plate bottom end protrudes from the clip notch.

6. The milling cutter structure according to claim 1, characterized in that: The upward inclination angle of the blade back strip is between 4.6 degrees ± 2 degrees.

7. The milling cutter structure according to claim 1, characterized in that: The downward slope angle of the blade strip is between 10 degrees ± 5 degrees.

8. The milling cutter structure according to claim 1, characterized in that: The blade is fixed in the notch of the clip, and the end between the two side plates of the blade has at least one hole-cutting tool body portion, and the hole-cutting tool body portion forms a hole-cutting blade with an inclined back surface tangent to the one side plate surface. The blade body is formed on the edge surface by one side of the hole-cutting blade, and the hole-cutting blade protrudes from the notch of the clip.

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