A drawing die assembly and drawing method for a stainless steel wire for an automobile spring

Abstract

The present application relates to the technical field of stainless steel wire production, and particularly discloses a drawing die assembly for automobile spring stainless steel wire, which comprises six drawing dies arranged in drawing passes in sequence, each drawing die comprising a die shell and a drawing die core, the drawing die core comprising an inlet section, a sizing section and an outlet section; the inlet section has an inclined slope and forms a compression angle; the outlet section has an inclined slope and forms an outlet angle; the compression angles of the inlet sections of the six drawing dies arranged in drawing passes in sequence gradually decrease, and the outlet angles of the outlet sections of the six drawing dies arranged in drawing passes in sequence gradually decrease. The present application uses 304 stainless steel wire rod with a diameter of 5.5 mm as raw material, and draws the raw material into stainless steel wire products with a diameter of 2.98 mm through six drawing passes, so that the products have good mechanical properties, a smooth and delicate surface and less damage. The drawing die assembly has stable nano-diamond composite coating and long service life.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of stainless steel wire production, in particular to a drawing die assembly and drawing method for a stainless steel wire for automobile springs. BACKGROUND

[0002] At present, 304 stainless steel wire products are widely used in various fields, especially in automobile production and manufacturing, and can be made into automobile spring parts and applied to important parts such as automobile suspensions. In the traditional drawing process of 304 stainless steel wire, the surface coating in the die is easy to fall off, resulting in high processing difficulty, low material yield, and unstable product quality. SUMMARY

[0003] In order to solve the technical problems of the surface coating of the product produced by the traditional drawing die being easy to peel off, high processing difficulty, low material yield, and unstable product quality in the prior art, one embodiment of the present application provides a drawing die assembly for a stainless steel wire for automobile springs, which comprises:

[0004] The first drawing die, the second drawing die, the third drawing die, the fourth drawing die, the fifth drawing die, and the sixth drawing die arranged in turn on the drawing pass each comprise a die shell and a drawing die core, and the drawing die core comprises an inlet section, a sizing section, and an outlet section;

[0005] The inlet section has an inclined slope and forms a compression angle; and the outlet section has an inclined slope and forms an outlet angle.

[0006] The compression angles of the inlet sections of the first drawing die, the second drawing die, the third drawing die, the fourth drawing die, the fifth drawing die, and the sixth drawing die arranged in turn on the drawing pass gradually decrease,

[0007] The outlet angles of the outlet sections of the first drawing die, the second drawing die, the third drawing die, the fourth drawing die, the fifth drawing die, and the sixth drawing die arranged in turn on the drawing pass gradually decrease.

[0008] In a preferred embodiment, the lengths of the sizing sections of the first drawing die, the second drawing die, the third drawing die, the fourth drawing die, the fifth drawing die, and the sixth drawing die arranged in turn on the drawing pass are different.

[0009] In a preferred embodiment, the inner surface of the inlet section, the inner surface of the sizing section, and the inner surface of the outlet section of the drawing die core of each drawing die are provided with a nano-diamond composite coating.

[0010] The nano-diamond composite coating of the drawing die core of the first drawing die, the second drawing die, the third drawing die, the fourth drawing die, the fifth drawing die and the sixth drawing die arranged on the drawing pass in sequence has gradually decreasing granularity.

[0011] In a preferred embodiment, the die shell of each drawing die is made of steel, and the drawing die core of each drawing die is made of tungsten-containing steel.

[0012] In a preferred embodiment, the compression angle of the inlet section of the first drawing die is 15°.

[0013] The compression angle of the inlet section of the second drawing die is 12°, and the compression angle of the inlet section of the third drawing die is 12°.

[0014] The compression angle of the inlet section of the fourth drawing die is 10°, and the compression angle of the inlet section of the fifth drawing die is 10°.

[0015] The compression angle of the inlet section of the sixth drawing die is 8°.

[0016] In a preferred embodiment, the exit angle of the exit section of the first drawing die is 20°.

[0017] The exit angle of the exit section of the second drawing die is 15°, and the exit angle of the exit section of the third drawing die is 15°.

[0018] The exit angle of the exit section of the fourth drawing die is 13°, and the exit angle of the exit section of the fifth drawing die is 13°.

[0019] The exit angle of the exit section of the sixth drawing die is 10°.

[0020] In a preferred embodiment, the length of the sizing section of the first drawing die is 1.5 mm, and the length of the sizing section of the second drawing die is 1.5 mm.

[0021] The length of the sizing section of the third drawing die is 1.1 mm, the length of the sizing section of the fourth drawing die is 1.1 mm, and the length of the sizing section of the fifth drawing die is 1.1 mm.

[0022] The length of the sizing section of the sixth drawing die is 1.2 mm.

[0023] In a preferred embodiment, the granularity of the nano-diamond composite coating of the drawing die core of the first drawing die is 20 μm, and the granularity of the nano-diamond composite coating of the drawing die core of the second drawing die is 20 μm.

[0024] The granularity of the nanodiamond composite coating of the drawing die core of the third drawing die is 15 μm, the granularity of the nanodiamond composite coating of the drawing die core of the fourth drawing die is 15 μm, the granularity of the nanodiamond composite coating of the drawing die core of the fifth drawing die is 15 μm, and the granularity of the nanodiamond composite coating of the drawing die core of the sixth drawing die is 15 μm.

[0025] Another embodiment of the present application provides a drawing method of the stainless steel wire for automobile spring, which draws the stainless steel wire for automobile spring by using the drawing die assembly of the stainless steel wire for automobile spring provided by the present application.

[0026] The technical scheme provided by the embodiment of the present application has at least the following beneficial effects:

[0027] The present application provides a drawing die assembly and a drawing method of the stainless steel wire for automobile spring, which coats the surface of the drawing die core with nanodiamond composite coating, develops a new production process, develops a special drawing die according to the different area reduction of each drawing pass, and adjusts the granularity of the nanodiamond composite coating of the drawing die core, the compression angle α, the exit angle β and the length h of the sizing section of the drawing die one by one, so that the surface of the finished product is fine, the lubricating layer is stable, the surface is not easy to be damaged, and the processing is easy to be shaped.

[0028] The present application provides a drawing die assembly and a drawing method of the stainless steel wire for automobile spring, which coats the surface of the drawing die core with nanodiamond composite coating, develops a new production process, develops a special drawing die according to the different area reduction of each drawing pass, and adjusts the granularity of the nanodiamond composite coating of the drawing die core, the compression angle α, the exit angle β and the length h of the sizing section of the drawing die one by one, so that the surface of the finished product is fine, the lubricating layer is stable, the surface is not easy to be damaged, and the processing is easy to be shaped. BRIEF DESCRIPTION OF DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiment description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0030] Fig. 1 is a schematic view of the drawing die assembly of the stainless steel wire for automobile spring of the present application arranged on the drawing pass.

[0031] Fig. 2 is a structural schematic view of the first drawing die of the present application.

[0032] Fig. 3 is a structural schematic view of the drawing die core of the present application. DETAILED DESCRIPTION

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] The terms “first,” “second,” “third,” “fourth,” etc. (if present) in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of the invention described herein can be implemented, for example, in orders other than those illustrated or described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0035] like Fig. 1 The diagram shown is a schematic of the drawing die assembly for stainless steel wire used in automotive springs according to the present invention, arranged on the drawing passes. Fig. 2 The diagram shown is a structural schematic of the first drawing die of the present invention. Fig. 3 The schematic diagram of the drawing die core of the present invention shown is combined with... Figs. 1 to 3 According to an embodiment of the present invention, a drawing die assembly for stainless steel wire for automotive springs is provided, comprising:

[0036] The first drawing die 100, the second drawing die 200, the third drawing die 300, the fourth drawing die 400, the fifth drawing die 500, and the sixth drawing die 600 are arranged sequentially on the drawing passes.

[0037] The first drawing die 100 is arranged on the first drawing pass, the second drawing die 200 is arranged on the second drawing pass, the third drawing die 300 is arranged on the third drawing pass, the fourth drawing die 400 is arranged on the fourth drawing pass, the fifth drawing die 500 is arranged on the fifth drawing pass, and the sixth drawing die 600 is arranged on the sixth drawing pass. The stainless steel wire S is drawn through six drawing passes.

[0038] According to an embodiment of the present invention, each drawing die (first drawing die 100, second drawing die 200, third drawing die 300, fourth drawing die 400, fifth drawing die 500 and sixth drawing die 600) includes a die shell and a drawing die core.

[0039] In the embodiment, the first drawing die 100 is taken as an example for illustration, the first drawing die 100 comprises a die shell 101 and a drawing die core 102. The drawing die core 102 is sleeved in the die shell 101, and the two are tightly fitted and installed together. The die shell 101 is made of steel material, and the drawing die core 102 is made of hard tungsten-containing steel material.

[0040] The drawing die core 102 comprises an entry section 103, a sizing section 104 and an exit section 105. The entry section 103 has an inclined slope and forms a compression angle α, and the exit section has an inclined slope and forms an exit angle β.

[0041] The inner surface of the entry section 103, the inner surface of the sizing section 104 and the inner surface of the exit section 105 of the drawing die core 102 are provided with a nano-diamond composite coating.

[0042] The second drawing die 200, the third drawing die 300, the fourth drawing die 400, the fifth drawing die 500 and the sixth drawing die 600 have the same structure as the first drawing die 100, and will not be described here.

[0043] The first drawing die 100, the second drawing die 200, the third drawing die 300, the fourth drawing die 400, the fifth drawing die 500 and the sixth drawing die 600 have different parameters, which will be described in detail below.

[0044] According to the embodiment of the present application, the compression angles of the entry sections of the first drawing die 100, the second drawing die 200, the third drawing die 300, the fourth drawing die 400, the fifth drawing die 500 and the sixth drawing die 600 arranged in sequence on the drawing passes gradually decrease.

[0045] Specifically, the compression angle α of the entry section of the first drawing die 100 is 15°.

[0046] The compression angle α of the entry section of the second drawing die 200 is 12°, and the compression angle α of the entry section of the third drawing die 300 is 12°.

[0047] The compression angle α of the entry section of the fourth drawing die 400 is 10°, and the compression angle α of the entry section of the fifth drawing die 500 is 10°.

[0048] The compression angle α of the entry section of the sixth drawing die 600 is 8°.

[0049] According to the embodiment of the present application, the exit angles of the exit sections of the first drawing die 100, the second drawing die 200, the third drawing die 300, the fourth drawing die 400, the fifth drawing die 500 and the sixth drawing die 600 arranged in sequence on the drawing passes gradually decrease.

[0050] Specifically, the exit angle β of the exit section of the first drawing die 100 is 20°.

[0051] The exit angle β of the exit section of the second drawing die 200 is 15°, and the exit angle β of the exit section of the third drawing die 300 is 15°.

[0052] The exit angle β of the exit section of the fourth drawing die 400 is 13°, and the exit angle β of the exit section of the fifth drawing die 500 is 13°.

[0053] The exit angle β of the exit section of the sixth drawing die 600 is 10°.

[0054] According to the embodiment of the present application, the length h of the sizing section of the first drawing die 100, the second drawing die 200, the third drawing die 300, the fourth drawing die 400, the fifth drawing die 500 and the sixth drawing die 600 arranged in sequence on the drawing pass is different.

[0055] Specifically, the length h of the sizing section of the first drawing die 100 is 1.5mm, and the length h of the sizing section of the second drawing die 200 is 1.5mm.

[0056] The length h of the sizing section of the third drawing die 300 is 1.1mm, the length h of the sizing section of the fourth drawing die 400 is 1.1mm, and the length h of the sizing section of the fifth drawing die 500 is 1.1mm.

[0057] The length h of the sizing section of the sixth drawing die 600 is 1.2mm.

[0058] According to the embodiment of the present application, the particle size of the nanometer diamond composite coating of the drawing die core of the first drawing die 100, the second drawing die 200, the third drawing die 300, the fourth drawing die 400, the fifth drawing die 500 and the sixth drawing die 600 arranged in sequence on the drawing pass gradually decreases.

[0059] Specifically, the particle size of the nanometer diamond composite coating of the drawing die core of the first drawing die 100 is 20μm, and the particle size of the nanometer diamond composite coating of the drawing die core of the second drawing die 200 is 20μm.

[0060] The particle size of the nanometer diamond composite coating of the drawing die core of the third drawing die 300 is 15μm, the particle size of the nanometer diamond composite coating of the drawing die core of the fourth drawing die 400 is 15μm, the particle size of the nanometer diamond composite coating of the drawing die core of the fifth drawing die 500 is 15μm, and the particle size of the nanometer diamond composite coating of the drawing die core of the sixth drawing die 600 is 15μm.

[0061] The present application adopts six-pass drawing process, reasonably formulates drawing pass procedure, respectively develops special mold according to different reduction of area of each pass, and provides a drawing method of stainless steel wire for automobile spring according to the embodiment of the present application.

[0062] In the embodiment, the 304 stainless steel wire rod with a diameter of Φ5.5 mm is used as raw material, and is drawn into a stainless steel wire product with a diameter of Φ2.98 mm through six drawing passes, and the stainless steel wire for automobile spring has a full austenite structure.

[0063] According to the embodiment of the present application, the first drawing die 100 is arranged on the first drawing pass, the second drawing die 200 is arranged on the second drawing pass, the third drawing die 300 is arranged on the third drawing pass, the fourth drawing die 400 is arranged on the fourth drawing pass, the fifth drawing die 500 is arranged on the fifth drawing pass, and the sixth drawing die 600 is arranged on the sixth drawing pass, and the stainless steel wire S is drawn, and the drawing process parameters of the stainless steel wire for automobile spring are shown in Table 1.

[0064] Table 1 Drawing process parameters of the stainless steel wire for automobile spring

[0065]

[0066]

[0067] Specific process parameters are as follows:

[0068] (1) The first drawing pass: the compression angle α of the inlet section of the drawing die core of the first drawing die 100 is 15°, the outlet angle β of the outlet section is 20°, the length h of the sizing section is 1.5 mm, and the particle size of the nano-diamond composite coating is 20 μm.

[0069] After the first drawing pass, the size of the stainless steel wire S before drawing is 5.5 mm, the size of the stainless steel wire S after drawing is 4.8 mm, and the reduction of area is 24%.

[0070] (2) The second drawing pass: the compression angle α of the inlet section of the drawing die core of the second drawing die 200 is 12°, the outlet angle β of the outlet section is 15°, the length h of the sizing section is 1.5 mm, and the particle size of the nano-diamond composite coating is 20 μm.

[0071] After the second drawing pass, the size of the stainless steel wire S before drawing is 4.8 mm, the size of the stainless steel wire S after drawing is 4.25 mm, and the reduction of area is 22%.

[0072] (3) the third drawing pass: the compression angle of the entrance section of the drawing die core of the third drawing die 300 is 12°, the exit angle of the exit section is 15°, the length of the sizing section h is 1.1mm, and the granularity of the nano-diamond composite coating is 15μm.

[0073] After the third drawing pass, the size of the stainless steel wire S before drawing is 4.25mm, the size of the stainless steel wire S after drawing is 3.8mm, and the drawing reduction is 20%.

[0074] (4) the fourth drawing pass: the compression angle of the entrance section of the drawing die core of the fourth drawing die 400 is 10°, the exit angle of the exit section is 13°, the length of the sizing section h is 1.1mm, and the granularity of the nano-diamond composite coating is 15μm.

[0075] After the fourth drawing pass, the size of the stainless steel wire S before drawing is 3.8mm, the size of the stainless steel wire S after drawing is 3.45mm, and the drawing reduction is 18%.

[0076] (5) the fifth drawing pass: the compression angle of the entrance section of the drawing die core of the fifth drawing die 500 is 10°, the exit angle of the exit section is 13°, the length of the sizing section h is 1.1mm, and the granularity of the nano-diamond composite coating is 15μm.

[0077] After the fifth drawing pass, the size of the stainless steel wire S before drawing is 3.45mm, the size of the stainless steel wire S after drawing is 3.15mm, and the drawing reduction is 16%.

[0078] (6) the sixth drawing pass: the compression angle of the entrance section of the drawing die core of the sixth drawing die 500 is 8°, the exit angle of the exit section is 10°, the length of the sizing section h is 1.2mm, and the granularity of the nano-diamond composite coating is 15μm.

[0079] After the sixth drawing pass, the size of the stainless steel wire S before drawing is 3.15mm, the size of the stainless steel wire S after drawing is 2.98mm, and the drawing reduction is 14%.

[0080] The present application uses the 304 stainless steel wire rod with a diameter of Φ5.5mm as raw material, develops the special drawing die according to the different drawing reduction of each pass, adjusts the granularity of the nano-diamond composite coating, the compression angle, the exit angle and the length of the sizing section of the drawing die core of the drawing die gradually, so that the finished product has a smooth surface, a stable lubricating layer, a surface not easy to damage, an easy-to-form processing, and finally the stainless steel wire product has the characteristics of a bright surface, no defects in appearance, excellent mechanical properties, good corrosion resistance and the like.

[0081] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, and are not intended to limit the present application; although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that the technical solutions recorded in the above embodiments can be modified, or some or all of the technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A drawing die assembly for stainless steel wire used in automotive springs, characterized in that, The drawing die assembly comprises: The first drawing die, the second drawing die, the third drawing die, the fourth drawing die, the fifth drawing die and the sixth drawing die arranged in sequence on the drawing pass each comprise a die shell and a drawing die core, and the drawing die core comprises an entry section, a sizing section and an exit section; The entry section has an inclined slope and forms a compression angle; and the exit section has an inclined slope and forms an exit angle; The compression angles of the entry sections of the first drawing die, the second drawing die, the third drawing die, the fourth drawing die, the fifth drawing die and the sixth drawing die arranged in sequence on the drawing pass gradually decrease, The exit angles of the exit sections of the first drawing die, the second drawing die, the third drawing die, the fourth drawing die, the fifth drawing die and the sixth drawing die arranged in sequence on the drawing pass gradually decrease; The compression angle of the entry section of the first drawing die is 15°; The compression angle of the entry section of the second drawing die is 12°, and the compression angle of the entry section of the third drawing die is 12°; The compression angle of the entry section of the fourth drawing die is 10°, and the compression angle of the entry section of the fifth drawing die is 10°; The compression angle of the entry section of the sixth drawing die is 8°; The exit angle of the exit section of the first drawing die is 20°; The exit angle of the exit section of the second drawing die is 15°, and the exit angle of the exit section of the third drawing die is 15°; The exit angle of the exit section of the fourth drawing die is 13°, and the exit angle of the exit section of the fifth drawing die is 13°; The exit angle of the exit section of the sixth drawing die is 10°.

2. The drawing die assembly of claim 1, wherein, The lengths of the sizing sections of the first drawing die, the second drawing die, the third drawing die, the fourth drawing die, the fifth drawing die and the sixth drawing die arranged in sequence on the drawing pass are different.

3. The drawing die assembly of claim 1, wherein, The inner surfaces of the entry section, the sizing section and the exit section of the drawing die core of each drawing die are provided with a nano-diamond composite coating; The nano-diamond composite coatings of the drawing die cores of the first drawing die, the second drawing die, the third drawing die, the fourth drawing die, the fifth drawing die and the sixth drawing die arranged in sequence on the drawing pass gradually decrease in granularity.

4. The drawing die assembly of claim 1, wherein, The die shell of each drawing die is made of steel, and the drawing die core of each drawing die is made of tungsten-containing steel.

5. The drawing die assembly of claim 2, wherein, The length of the sizing section of the first drawing die is 1.5 mm, and the length of the sizing section of the second drawing die is 1.5 mm; The length of the sizing section of the third drawing die is 1.1 mm, the length of the sizing section of the fourth drawing die is 1.1 mm, and the length of the sizing section of the fifth drawing die is 1.1 mm; The length of the sizing section of the sixth drawing die is 1.2 mm.

6. The drawing die assembly of claim 3, wherein, The granularity of the nano-diamond composite coating of the drawing die core of the first drawing die is 20 μm, and the granularity of the nano-diamond composite coating of the drawing die core of the second drawing die is 20 μm; The nano-diamond composite coating particle size of the drawing die core of the third drawing die is 15 μm, the nano-diamond composite coating particle size of the drawing die core of the fourth drawing die is 15 μm, the nano-diamond composite coating particle size of the drawing die core of the fifth drawing die is 15 μm, and the nano-diamond composite coating particle size of the drawing die core of the sixth drawing die is 15 μm.

7. A method of drawing a stainless steel wire for an automobile spring, characterized by, The drawing method utilizes the drawing die assembly of any one of claims 1 to 6 to draw a stainless steel wire for automobile springs.

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