Threaded roller crescent groove chamfering cutter and chamfering process

Abstract

The invention discloses a thread roller crescent groove chamfering tool and a chamfering process, and belongs to the technical field of thread rollers. The thread roller crescent groove chamfering cutter comprises a cutter body and a fly cutter rod, the cutter body comprises a clamping part and a cutting edge, one end of the clamping part is connected with the fly cutter rod, the other end of the clamping part is provided with the cutting edge, the width W of the cutting edge meets the condition that W = W1 + 2X + delta, and W1 is the opening width of a crescent groove. According to the thread roller crescent groove chamfering tool and the chamfering technology, through the special chamfering tool and the chamfering technology, interference between the tip of a transverse rib and the edge of a crescent groove is effectively eliminated, deformation of the transverse rib of a thread steel rib and abrasion of a roller are reduced, the cooling efficiency of a tool nose is improved through the design of a water guide face of a cooling hole segmentation strip, and the service life of the tool nose is prolonged. And early failure caused by hot cracks is avoided, an original crescent groove machining program is directly reused, only the delta Z compensation amount is superposed, and the programming debugging time is saved.

Description

Technical Field

[0001] The present invention relates to the technical field of thread rolling rolls, and specifically to a chamfering tool and a chamfering process for the crescent groove of a thread rolling roll. Background Art

[0002] In the production process of threaded steel bars, transverse ribs, namely crescent grooves, need to be machined in the pass grooves of the rolling rolls. Since the crescent grooves on the rolling rolls are grooves with a certain depth, transverse ribs with a convex trapezoidal cross-section are formed on the surface of the round steel bars during steel rolling production. The national standard has clear requirements for the height and width of the transverse ribs of threaded steel bars. However, due to the certain height of the transverse ribs of the threaded steel bars, during the steel rolling production process, when the transverse ribs of the formed steel bars disengage from the crescent grooves of the rolling rolls, the tips of the transverse ribs may interfere with the edges of the crescent grooves, resulting in deformation of the transverse ribs of the threaded steel bars and accelerating the local wear of the rolling rolls. Summary of the Invention

[0003] The purpose of the present invention is to provide a chamfering tool and a chamfering process for the crescent groove of a thread rolling roll. Through a special chamfering tool and chamfering process, the interference between the tip of the transverse rib and the edge of the crescent groove is effectively eliminated, the deformation of the transverse ribs of the threaded steel bars and the wear of the rolling rolls are reduced, and the water guiding surface design of the cooling hole dividing strip improves the tip cooling efficiency and avoids early failure caused by thermal cracks, solving the problems raised in the above background art.

[0004] To achieve the above purpose, the present invention provides the following technical solution: A chamfering tool for the crescent groove of a thread rolling roll includes a tool body and a flying cutter bar. The tool body includes a clamping part and a cutting edge. One end of the clamping part is connected to the flying cutter bar, and the flying cutter bar drives the tool body to work. The flying cutter bar resists the lateral cutting force, avoids over-tolerance of the chamfer size caused by tool deflection, optimizes the force and heat transfer path, and protects the chamfering tool from being damaged by abnormal loads. The other end of the clamping part is provided with a cutting edge. The width W of the cutting edge satisfies: W = W1 + 2X + Δ, where W1 is the opening width of the crescent groove, X is the chamfer width, and Δ is the safety margin, and the range of Δ is 0.2 - 0.5 mm.

[0005] Preferably, the two sides of the cutting edge are provided with cutting edges and tool tips. The rake angle γ of the cutting edge is 8° - 12°, the clearance angle α is 10° - 15°, and the radius of the tool tip arc matches the chamfer width.

[0006] Preferably, the tool body further includes a chip removal groove and a cooling hole. One side of the chip removal groove is connected to the connection between the cutting edge and the clamping part. The chip removal groove and the cutting edge form an obtuse angle greater than 100°, which is convenient for the chips to be quickly discharged. The cooling hole penetrates through the clamping part and the cutting edge.

[0007] Preferably, the cooling hole includes a liquid inlet hole, an axial internal cooling hole, and an inclined hole connected in sequence. The inclined hole is arranged close to the tool tip, and a dividing strip is arranged at the middle position of the inclined hole.

[0008] Preferably, a water guiding surface is provided on the inner wall of the dividing strip. The water guiding surface is inclined. When the coolant flushes out of the inclined holes, it first contacts the dividing strip, and the water flow is cut into two parts. Under the action of the water guiding surface, the two parts flow out in different directions respectively to cool the tool tip.

[0009] Another technical problem to be solved by the present invention is to provide a chamfering process for the crescent groove chamfering tool of a thread rolling roll, including the following steps:

[0010] S1. Determination of the cross-sectional dimensions of the crescent groove: Determine the cross-sectional dimensions of the crescent groove according to the specifications of the threaded steel bar.

[0011] S2. Calculation of chamfering parameters: Calculate the angle and width of the chamfer according to the requirements of the chamfer.

[0012] S3. Making a stainless steel template: Make a template with a 0.5 mm stainless steel plate according to the angle and width of the chamfer, with a tolerance of ±0.02 mm.

[0013] S4. Designing and machining the chamfering tool: Design a special chamfering tool according to the chamfering parameters, and machine the chamfering tool with a five-axis tool grinder, with the circular runout of the cutting edge ≤0.005 mm.

[0014] S5. Clamping the fly cutter bar: Select a suitable fly cutter bar according to the size of the chamfering tool, calculate the tool mounting length according to the size of the chamfer, and control the overhang L according to the formula L = R + 2X + 0.5D, where R is the hole shape radius, X is the chamfer width, and D is the cutter bar diameter.

[0015] S6. Tool setting: Set the zero point when the contact force between the inclined edge and the edge of the crescent groove ≤5 N.

[0016] S7. Chamfering machining: Use the original crescent groove machining program, superimpose the chamfering depth compensation amount ΔZ = X·tanθ, and start chamfering machining.

[0017] Preferably, the cross-sectional dimensions of the crescent groove include the crescent groove bottom width W2, the crescent groove depth H, the crescent groove angle A, the crescent groove opening width W1, the chamfering tool angle B, and the groove-shaped arc radius R.

[0018] Preferably, the chamfering angle θ = 25° - 35°, and the width X = 0.3 - 0.8 mm.

[0019] Preferably, the width of the chamfering tool should be greater than the crescent groove opening width W1 plus twice the chamfer width X. Select the chamfering tool material according to the material of the rolling roll. For high-speed steel rolling rolls, use carbide chamfering tools; for tungsten carbide rolling rolls, select diamond chamfering tools, and machine and manufacture the chamfering tool on a special tool grinder according to the drawing.

[0020] Preferably, in step S7, the coolant pressure ≥3 MPa, the flow rate ≥8 L / min, and the spraying angle forms an included angle of 20° - 30° with the cutting edge.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0022] The thread rolling roll crescent groove chamfering tool and chamfering process proposed by the present invention, through the mathematical relationship of the formulas W = W1 + 2X + Δ and ΔZ = X·tanθ, achieve a chamfer width tolerance of ±0.05 mm and an angle deviation of ≤0.5°. The rapid detection method for stainless steel templates improves the quality sampling inspection efficiency. Through the special chamfering tool and chamfering process, the interference between the transverse rib tip and the crescent groove edge is effectively eliminated, reducing the deformation of the transverse ribs of the threaded steel bar and the wear of the roll. The design of the water guiding surface of the cooling hole partition strip improves the tool tip cooling efficiency, avoiding early failure caused by thermal cracks. By directly reusing the original crescent groove processing program and only superimposing the ΔZ compensation amount, the programming and debugging time is saved. The formula for the clamping length of the fly cutter bar L = R + 2X + 0.5D enables rapid tool change. Description of the Drawings

[0023] Figure 1 Schematic diagram of the crescent groove chamfering of the present invention;

[0024] Figure 2 Schematic diagram of the crescent groove chamfering range of the present invention;

[0025] Figure 3 Schematic diagram of the crescent groove chamfering processing state of the present invention;

[0026] Figure 4 Structural diagram of the tool body of the present invention;

[0027] Figure 5 Cross-sectional view of the tool body of the present invention;

[0028] Figure 6 Structural diagram of the partition strip of the present invention.

[0029] In the figure: 1. Tool body; 11. Clamping part; 12. Cutting edge; 121. Edge; 122. Tool tip; 13. Chip removal groove; 14. Cooling hole; 141. Liquid inlet hole; 142. Axial internal cooling hole; 143. Oblique hole; 1431. Partition strip; 14311. Water guiding surface; 2. Fly cutter bar. Detailed Embodiments

[0030] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0031] To solve the problem that in the existing steel rolling production process, when the transverse ribs of the formed reinforcing bars are separated from the crescent grooves of the rolling rolls, the tips of the transverse ribs may interfere with the edges of the crescent grooves, resulting in the deformation of the transverse ribs of the threaded reinforcing bars and accelerating the local wear of the rolling rolls, please refer to Figures 1 - 6 , the following technical solutions are provided in this embodiment:

[0032] The chamfering tool for the crescent groove of the threaded rolling roll includes a tool body 1 and a flying cutter bar 2. The tool body 1 includes a clamping part 11, a cutting edge 12, a chip fluting 13 and a cooling hole 14. One end of the clamping part 11 is connected to the flying cutter bar 2, and the flying cutter bar 2 drives the tool body 1 to work. The flying cutter bar 2 resists the lateral cutting force, avoids the over-tolerance of the chamfer size caused by tool deflection, optimizes the force and heat transfer path, and protects the chamfering tool from being damaged by abnormal loads. The other end of the clamping part 11 is provided with the cutting edge 12 and the chip fluting 13. One side of the chip fluting 13 is connected to the connection part of the cutting edge 12 and the clamping part 11. The chip fluting 13 and the cutting edge 12 form an obtuse angle greater than 100°, which is convenient for the rapid discharge of chips. The cooling hole 14 penetrates through the clamping part 11 and the cutting edge 12.

[0033] Specifically, the clamping part 11 is of a cylindrical structure. The width of the cutting edge 12 is the same as the diameter of the clamping part 11, and the width W of the cutting edge 12 satisfies: W = W1 + 2X + Δ, where W1 is the opening width of the crescent groove, X is the chamfer width, and Δ is the safety margin, 0.2 - 0.5 mm. Knife edges 121 and tool tips 122 are provided on both sides of the cutting edge 12. The rake angle γ of the knife edge 121 is 8° - 12°, and the clearance angle α is 10° - 15°. The arc radius of the tool tip 122 matches the chamfer width.

[0034] The cooling hole 14 includes a liquid inlet hole 141, an axial internal cooling hole 142 and an inclined hole 143. The liquid inlet hole 141, the axial internal cooling hole 142 and the inclined hole 143 are connected in sequence. The end of the inclined hole 143 is close to the tool tip 122 and is located between two tool tips 122. A dividing strip 1431 is provided at the middle position of the inclined hole 143. A water guiding surface 14311 is provided on the inner wall of the dividing strip 1431. The water guiding surface 14311 is inclined. When the coolant flushes out of the inclined hole 143, it first contacts the dividing strip 1431, and the water flow is cut into two parts and flows out in different directions under the action of the water guiding surface 14311 to cool the tool tip 122.

[0035] To better demonstrate the chamfering process of the chamfering tool for the crescent groove of the threaded rolling roll, this embodiment now provides a chamfering process for the chamfering tool for the crescent groove of the threaded rolling roll, including the following steps:

[0036] S1. Determination of the crescent groove section size: Determine the crescent groove section size according to the specification GB / T 1499.2 of the threaded reinforcing bar, including the bottom width W2 of the crescent groove, the depth H of the crescent groove, the angle A of the crescent groove, the opening width W1 of the crescent groove, the chamfering tool angle B and the groove type arc radius R;

[0037] S2. Calculate chamfer parameters: Calculate the angle and width of the chamfer according to the requirements of the chamfer. The angle θ = 25° - 35°, and the width X = 0.3 - 0.8 mm.

[0038] S3. Make a stainless - steel template: Make a template with a 0.5 - mm stainless - steel plate according to the angle and width of the chamfer, with a tolerance of ±0.02 mm.

[0039] S4. Design and machine the chamfering tool: Design a special chamfering tool according to the chamfer parameters. The width of the chamfering tool should be greater than the width W1 of the crescent - shaped groove opening plus twice the chamfer width X. Draw the machining drawing of the chamfering tool, select the chamfering - tool material according to the material of the roll. For high - speed - steel rolls, use carbide chamfering tools; for tungsten - carbide rolls, choose diamond chamfering tools. Machine the chamfering tool on a special tool - grinding machine according to the drawing. Use a five - axis tool - grinding machine to machine the chamfering tool, and the circular run - out of the cutting edge ≤0.005 mm.

[0040] S5. Clamp the fly - cutter bar 2: Select a suitable fly - cutter bar 2 according to the size of the chamfering tool. Calculate the tool - mounting length according to the chamfer size. The overhang L is controlled by the formula L = R + 2X+0.5D, where R is the hole - profile radius, X is the chamfer width, and D is the tool - bar diameter.

[0041] S6. Set the zero point when the contact force between the inclined edge and the edge of the crescent - shaped groove is ≤5 N during tool setting.

[0042] S7. Use the original crescent - shaped groove machining program and superimpose the chamfer - depth compensation amount ΔZ = X·tanθ to start chamfering machining.

[0043] Example 1: Use the above method to machine High - speed - steel rolls for ribbed steel bars.

[0044] 1. Machining - object parameters

[0045] Roll material: Cr12MoV high - speed steel, hardness 58HRC;

[0046] Crescent - shaped groove dimensions (GB / T 1499.2): Opening width W1 = 10.2 mm, bottom width W2 = 8.0 mm, depth H = 3.5 mm, groove - type arc radius R = 18 mm.

[0047] 2. Chamfer - tool configuration

[0048] Tool material: YG8 carbide, TiAlN coating,

[0049] Geometric parameters:

[0050] Cutting - edge width W = W1 + 2X+Δ = 10.2+2×0.5 + 0.3 = 11.5 mm,

[0051] The rake angle γ = 10°, the clearance angle α = 12°, the radius R of the tool tip (122) is 0.5 mm.

[0052] The inclination angle of the cooling hole is 45°, and the inclination angle of the water guiding surface 14311 is 20°.

[0053] 3. Process execution

[0054] Chamfering parameters: θ = 30°, X = 0.5 mm → ΔZ = 0.5 × tan30° ≈ 0.29 mm

[0055] Tool setting length: L = 18 + 2 × 0.5 + 0.5 × 16 = 27 mm

[0056] Cutting parameters: rotational speed n = 1200 rpm, feed f = 0.08 mm / r, coolant pressure 3 MPa, flow rate 8 L / min.

[0057] 4. Effect verification

[0058] Index Result Chamfer width tolerance ±0.04 mm Single roll grinding life 2200 tons (+37%) Tool life (single edge) 150 pieces

[0059] Example 2: Using the above method for Processing of tungsten carbide rolls for deformed steel bars.

[0060] 1. Parameters of the processing object

[0061] Roll material: YG15 tungsten carbide, hardness 86 HRA;

[0062] Sizes of the crescent grooves: W1 = 14.5 mm, W2 = 11.8 mm, H = 4.2 mm, R = 28 mm

[0063] 2. Chamfering tool configuration

[0064] Tool material: polycrystalline diamond, CDW302

[0065] Geometric parameters:

[0066] Width of the cutting edge W = 14.5 + 2 × 0.7 + 0.4 = 16.3 mm

[0067] γ = 8°, α = 10°, tool tip R = 0.7 mm

[0068] Inner cooling hole diameter The dividing strip is coated with diamond - like carbon.

[0069] 3. Process execution

[0070] Chamfering parameters: θ = 28°, X = 0.7 mm → ΔZ = 0.7 × tan28° ≈ 0.37 mm

[0071] Tool loading length: L = 28 + 2 × 0.7 + 0.5 × 20 = 39.4 mm

[0072] Cutting parameters: n = 800 rpm, f = 0.05 mm / r, MQL lubrication (vegetable oil-based, flow rate 60 ml / h)

[0073] 4. Effect verification

[0074] Index Result Chamfer angle deviation ±0.3° Roll life 35,000 tons (+75%) Tool wear amount (VB) 0.12 mm / 100 pieces

[0075] It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or elements inherent to such process, method, article or device.

[0076] Although the embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention.

Claims

1. Thread rolling roll crescent groove chamfering tool, comprising a tool body (1) and a flying cutter bar (2), characterized in that: The tool body (1) includes a clamping portion (11) and a cutting edge (12). One end of the clamping portion (11) is connected to the flying cutter bar (2), and the other end of the clamping portion (11) is provided with the cutting edge (12). The width W of the cutting edge (12) satisfies: W = W1 + 2X + Δ, where W1 is the width of the crescent groove opening, X is the chamfer width, Δ is the safety margin, and the range of Δ is 0.2 - 0.5 mm.

2. The threading roll crescent groove chamfering tool according to claim 1, characterized in that: Edges (121) and a tool tip (122) are provided on both sides of the cutting edge (12). The front angle γ of the edge (121) is 8° - 12°, the rear angle α is 10° - 15°, and the arc radius of the tool tip (122) matches the chamfer width.

3. The threading roll crescent groove chamfering tool according to claim 2, characterized in that: The tool body (1) further includes a chip removal groove (13) and a cooling hole (14). One side of the chip removal groove (13) is connected to the connection between the cutting edge (12) and the clamping portion (11), and the cooling hole (14) penetrates through the clamping portion (11) and the cutting edge (12).

4. The thread rolling roll crescent groove chamfering tool according to claim 3, characterized in that: The cooling hole (14) includes a liquid inlet hole (141), an axial internal cooling hole (142), and an inclined hole (143) connected in sequence. The inclined hole (143) is arranged close to the tool tip (122), and a dividing strip (1431) is arranged at the middle position of the inclined hole (143).

5. The threading roll crescent groove chamfering tool according to claim 4, wherein: A water guiding surface (14311) is arranged on the inner wall of the dividing strip (1431), and the water guiding surface (14311) is inclined.

6. A chamfering process for a chamfering tool of the crescent groove of a thread rolling roll according to any one of claims 1-5, characterized in that, It includes the following steps: S1. Determination of the crescent groove cross-sectional dimensions: Determine the crescent groove cross-sectional dimensions according to the specifications of the ribbed steel bars. S2. Calculation of the chamfer parameters: Calculate the angle and width of the chamfer according to the requirements of the chamfer. S3. Making a stainless steel template: Make a template with a 0.5 mm stainless steel plate according to the chamfer angle and width, with a tolerance of ±0.02 mm. S4. Designing and machining the chamfering tool: Design a special chamfering tool according to the chamfer parameters, and machine the chamfering tool with a five-axis tool grinder, with the circular runout of the edge ≤ 0.005 mm. S5. Clamping the flying cutter bar (2): Select a suitable flying cutter bar (2) according to the size of the chamfering tool, calculate the tool mounting length according to the chamfer size, and control the overhang L according to the formula L = R + 2X + 0.5D, where R is the hole profile radius, X is the chamfer width, and D is the tool bar diameter. S6. Tool alignment: Set the zero point when the contact force between the inclined edge and the crescent groove edge ≤ 5 N. S7. Chamfering machining: Adopt the original crescent groove machining program, superimpose the chamfer depth compensation amount ΔZ = X·tanθ, and start chamfering machining.

7. The chamfering process of the thread rolling roll crescent groove chamfering tool according to claim 6, characterized in that: The crescent groove cross-sectional dimensions include the crescent groove bottom width W2, the crescent groove depth H, the crescent groove angle A, the crescent groove opening width W1, the chamfering tool angle B, and the groove profile arc radius R.

8. The chamfering process of the thread rolling roll crescent groove chamfering tool according to claim 6, characterized in that: The chamfer angle θ = 25° - 35°, and the width X = 0.3 - 0.8 mm.

9. The chamfering process of the chamfering tool for the crescent groove of the thread rolling roll according to claim 6, characterized in that: The width of the chamfering tool should be greater than the crescent groove opening width W1 plus twice the chamfer width X, and select the chamfering tool material according to the material of the roll.

10. The chamfering process of the chamfering tool for the crescent groove of the thread rolling roll according to claim 6, characterized in that: In step S7, the coolant pressure ≥ 3 MPa, the flow rate ≥ 8 L / min, and the spraying angle forms an angle of 20° - 30° with the edge.

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