WO2022178930A1 - Manufacturing method for monofilament steel cord and steel wire stress relieving device - Google Patents

Abstract

A manufacturing method for a monofilament steel cord and a steel wire stress relieving device. The manufacturing method for a monofilament steel cord comprises steps of pretreatment for a steel wire rod, dry drawing, heat treatment electroplating, wet drawing, stress relief, straightening, and wire winding. The stress relieving device comprises a heating coil (3) and a straightener (1), the heating coil (3) and the straightener (1) are sequentially arranged in a direction of steel wire conduction, and one side of the straightener (1) is provided with an air-cooling chip removing device (2). According to the manufacturing method for a monofilament steel cord, a step of stranding is not performed after the step of wet drawing, the residual stress of the monofilament steel cord is relieved by the steel wire stress relieving device, the product quality and the production efficiency are improved, and the manufacturing cost is reduced.

Description

A kind of manufacturing method of monofilament steel cord and steel wire stress relief device technical field

The invention belongs to the technical field of steel cords, and in particular relates to a manufacturing method of a monofilament steel cord and a steel wire stress relief device.

Background technique

With the rapid development of the automobile industry and highways, as well as the continuous improvement of environmental regulations, the development of tires needs to meet the requirements of green environmental protection, light weight, longer service life and more retreading times to ensure sustainable development. The belt layer is the main force-bearing component of the radial tire, and it is periodically subjected to deformation stress such as tensile, bending, and shearing. Only with high rubber permeability and fatigue resistance can steel cords for belts help improve the performance of the belts and thus improve the quality of tires.

The monofilament steel cord constitutes the tire belt layer, which can reduce the thickness of the belt layer, which is beneficial to the lightweight of the tire and the improvement of fuel consumption. Since the monofilament steel cord has no point or line contact, there is no wire-to-wire friction during tire use. The steel wire can achieve full penetration of glue, thereby avoiding corrosion caused by moisture entering the interior of the steel cord. Therefore, it has good anti-fatigue performance and adhesive performance, and reduces the manufacturing cost of the tire.

Invention patent application CN201410595340.3 discloses a method for manufacturing monofilament steel cords, and invention patent application CN201910190843.5 discloses a method for preparing steel monofilaments for reinforcing tire belt layers, both of which are in the process of twisting The production efficiency is low and the manufacturing cost is high. In addition, the wet drawn monofilament is subjected to torsional plastic deformation during the twisting process of the stranding machine, and the surface of the monofilament steel cord is easily damaged, which affects the fatigue performance of the product. . Since the monofilament drawn by wet drawing has the ring diameter and warping distance, the installation of a straightener or a twister on the wet drawing machine tool to produce monofilament steel cord has problems such as large debugging amount and large bow height fluctuation, which cannot be satisfied. Requirements for mass production of monofilament steel cords.

SUMMARY OF THE INVENTION

The object of the present invention is to overcome the deficiencies in the prior art, and to provide a method for manufacturing a monofilament steel cord and a steel wire stress relieving device. After the wet drawing process, the stranding process is not carried out, and the monofilament steel cord is eliminated through the steel wire stress relieving device. The residual stress of the wire improves the product quality and production efficiency, and reduces the manufacturing cost.

The invention provides the following technical solutions:

A steel wire stress relief device includes a heating coil and a straightener, the heating coil and the straightener are arranged in sequence along the direction of the wire conduction, and an air-cooled chip removal device is provided on one side of the straightener.

Further, along the direction of wire conduction, the front end of the heating coil is provided with a traction plate, and the rear end of the straightener is provided with a constant tension automatic control system.

Further, guide wheels are provided between the traction plate and the heating coil, between the heating coil and the straightener and at the rear end of the straightener.

Further, the specific steps of stress relief of the finished wire diameter steel wire include: heating with a heating coil, and then straightening the steel wire with a straightener.

A method for manufacturing a monofilament steel cord, comprising the following steps:

The wire rod is mechanically peeled, then cleaned, coated with boron and then dried;

Use a straight-forward wire drawing machine to perform several passes of dry drawing to obtain dry drawn steel wire;

Heat treatment and cooling of the dry drawn steel wire, followed by pickling, copper plating and galvanizing, medium frequency thermal diffusion, phosphating, water washing and soap drying;

The copper-plated wire after electroplating is wet-drawn for several passes by using a reversing water tank wire drawing machine to obtain the finished wire diameter wire;

The wire stress relief device is used for stress relief and straightening of the finished wire diameter steel wire, and the wire take-up I-shaped wheel is used to take up the wire.

Further, the carbon content of the wire rod is 0.55-1.05%, and the diameter is 5.0-7.5 mm.

Further, the diameter of the dry drawing steel wire is 0.82-3.0mm; in the process of dry drawing and drawing, for the process steel wire with true strain ε>1.8, after intermediate heat treatment, several passes of dry drawing are continued to obtain dry drawing. Pull the wire.

Further, the specific steps of heat-treating the dry-drawn steel wire include: heating to austenite at 900-1100° C., and then quenching to pearlite.

Further, the coating thickness of the dry drawn steel wire after copper plating is 0.10-0.50 μm, and the copper content is 60.5-66%.

Further, the speed of wet drawing is 0.5-17m/s, preferably 2-10m/s, and the diameter of the obtained finished wire diameter steel wire is 0.15-0.50mm, preferably 0.22-0.40mm.

Further, the specific steps for stress relief of the finished wire diameter steel wire include: first heating the wire through a heating coil, and then straightening the wire through a straightener.

Further, the heating power of the heating coil is 1-300W; the ratio of the straightening roller groove width to the diameter of the finished steel wire is 1-10, and the ratio of the groove depth to the diameter of the finished steel wire is 0.5-10; A constant tension automatic control system is set at the rear end of the straightener for tension control, and the tension of the constant tension automatic control system is controlled at 0.5-2kg.

Further, the strength grade of the manufactured monofilament steel cord is not lower than 3275-2000D, and D is the diameter of the monofilament; preferably, it is not lower than 3800-2000D; more optimal, it is not lower than 4100-2000D; , not less than 4400-2000D.

Compared with the prior art, the beneficial effects of the present invention are:

(1) The present invention provides a steel wire stress relief device, which effectively eliminates the residual stress of the monofilament steel cord, reduces the risk of damage to the surface of the monofilament steel cord, and is conducive to improving product quality;

(2) The manufacturing method of a monofilament steel cord provided by the present invention realizes the production of the monofilament steel cord in the wet drawing process, without going through the twisting process, the produced monofilament steel cord bow height and twisted strands The products produced by the machine tool are quite similar, the process is simple, the product quality and production efficiency are improved, and the manufacturing cost is reduced.

Description of drawings

Fig. 1 is the structural representation of the wire stress relief device;

Marked as: 1. Straightener; 2. Air-cooled chip removal device; 3. Heating coil; 4. Traction disc; 5. Constant tension automatic control system; 6. Guide wheel; 7. Steel wire.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings. The following examples are only used to illustrate the technical solutions of the present invention more clearly, and cannot be used to limit the protection scope of the present invention.

Example 1

As shown in FIG. 1 , the present embodiment provides a wire stress relief device, which includes a heating coil 3 and a straightener 1 . The heating coil 3 and the straightener 1 are arranged in sequence along the conducting direction of the wire 7 . There is an air-cooled chip removal device 2 on the side. Along the conducting direction of the steel wire 7 , the front end of the heating coil 3 is provided with a traction plate 4 , and the back end of the straightener 1 is provided with a constant tension automatic control system 5 . Guide pulleys 6 are provided between the traction plate 4 and the heating coil 3, between the heating coil 3 and the straightener 1, and at the rear end of the straightener 1.

Taking a 1×0.22UT monofilament steel cord as an example, this embodiment provides a method for manufacturing a monofilament steel cord, which includes the following steps:

(1) Wire rod pretreatment: mechanically peel the wire rod with a carbon content of 0.92% and a diameter of 5.5mm, then clean and dry after boron coating;

(2) Dry drawing: Use a straight-forward wire drawing machine to carry out several passes of dry drawing, and draw to 3.14mm. For the process steel wire with true strain ε>1.8, after intermediate heat treatment, continue to use a straight-forward wire drawing machine for several times. Dry drawing is done in passes, and finally a dry drawn wire with a diameter of 1.5mm is obtained;

(3) Heat treatment and electroplating: The dry drawn steel wire is heated to austenite at 980-1050℃, then quenched to pearlite, and then pickling, copper plating and galvanizing, medium frequency thermal diffusion, phosphating, water washing and Soap dipping and drying, wherein the thickness of the coating after copper plating is 0.3 μm, and the content of copper is 63%;

(4) Wet drawing: The copper-plated wire after electroplating is subjected to several passes of wet drawing by using a reversing water tank drawing machine, and the speed of wet drawing is 4m/s, and finally a finished wire with a diameter of 0.22mm is obtained. ;

(5) Embodiment 1 provides a wire stress relief device, and uses the wire stress relief device to perform stress relief and straightening on the finished wire diameter steel wire. Specifically, as shown in FIG. 1 , the finished wire diameter steel wire travels through the guide wheel 6 to the heating coil 3 for heating to eliminate residual stress, and then continues to travel to the straightener 1 for wire straightening. One side of the straightener 1 is provided with The air-cooled chip removal device 2 can remove the impurities on the surface of the steel wire, the constant tension automatic control system 5 provided at the rear end of the straightener 1 performs tension control, and finally the wire is taken up by the take-up I-shaped wheel. Among them, the heating power of the heating coil 3 is 11W; the ratio of the straightening roller groove width of the straightener 1 to the diameter of the finished steel wire is 2.5, the ratio of the groove depth to the diameter of the finished steel wire is 1.3, and the number of bearings is 27; constant tension The tension of the automatic control system 5 is controlled at 0.7kg.

The performance detection after aging is carried out to the monofilament steel cord manufactured by Example 1 and the traditional monofilament steel cord produced by the twisting strand process, and the test results are as follows in Table 1:

Table 1 embodiment 1 monofilament steel cord performance index comparison table

item/average	Bow height/mm	bow height standard deviation	Breaking force/N
Example 1	12	2.48	150
Tradition	16	3.21	148

It can be seen from Table 1 that the 1×0.22UT monofilament steel cord produced in the embodiment of the present invention has the same bow height and average breaking force as the traditional one.

Example 2

Taking 1×0.30HT monofilament steel cord as an example, a method for manufacturing monofilament steel cord is provided, which includes the following steps:

(1) Wire rod pretreatment: mechanically peel the wire rod with a carbon content of 0.82% and a diameter of 5.5mm, then clean and dry after boron coating;

(2) Dry drawing: use a straight-forward wire drawing machine to perform several passes of dry drawing to obtain a dry drawn wire with a diameter of 1.8 mm;

(3) Heat treatment and electroplating: The dry drawn steel wire is heated to austenite at 980-1060℃, then quenched to pearlite, and then pickling, copper plating and galvanizing, medium frequency thermal diffusion, phosphating, water washing and Soap dipping and drying, wherein the thickness of the coating after copper plating is 0.28 μm, and the content of copper is 64%;

(4) Wet drawing: The copper-plated wire after electroplating is subjected to several passes of wet drawing by using a reversing water tank wire drawing machine. ;

(5) Embodiment 2 provides the same wire stress relief device as in Embodiment 1, and uses the wire stress relief device to perform stress relief and straightening on the finished wire diameter steel wire. Specifically, as shown in FIG. 1 , the finished wire diameter steel wire travels through the guide wheel 6 to the heating coil 3 for heating to eliminate residual stress, and then continues to travel to the straightener 1 for wire straightening. One side of the straightener 1 is provided with The air-cooled chip removal device 2 can remove the impurities on the surface of the steel wire, the constant tension automatic control system 5 provided at the rear end of the straightener 1 performs tension control, and finally the wire is taken up by the take-up I-shaped wheel. Among them, the heating power of the heating coil 3 is 31W; the ratio of the straightening roller groove width of the straightener 1 to the diameter of the finished steel wire is 3, the ratio of the groove depth to the diameter of the finished steel wire is 1.5, and the number of bearings is 21; constant tension The tension of the automatic control system 5 is controlled at 1kg.

The performance detection after aging is carried out to the monofilament steel cord manufactured by embodiment 2 and the traditional monofilament steel cord produced by the twisting strand process, and the test results are as follows in Table 2:

Table 2 embodiment 2 monofilament steel cord performance index comparison table

item/average	Bow height/mm	bow height standard deviation	Breaking force/N
Example 2	9	1.96	225
Tradition	12	2.73	224

It can be seen from Table 2 that the 1×0.30HT monofilament steel cord produced in the embodiment of the present invention has the same bow height and average breaking force as the traditional one.

Example 3

Taking a 1×0.40NT monofilament steel cord as an example, a method for manufacturing a monofilament steel cord is provided, which includes the following steps:

(1) Wire rod pretreatment: mechanically peel the wire rod with a carbon content of 0.62% and a diameter of 5.5mm, then clean and dry after boron coating;

(2) Dry drawing: use a straight wire drawing machine to carry out several passes of dry drawing to obtain a dry drawn wire with a diameter of 2.05mm;

(3) Heat treatment and electroplating: dry-drawn steel wire is heated to austenite at 980-1050℃, then quenched to pearlite, and then pickled, copper-plated, galvanized, medium-frequency thermal diffusion, phosphating, water-washed and soaped in sequence. Dipping and drying, wherein the thickness of the plating layer after copper plating is 0.25 μm, and the content of copper is 63.5%;

(4) Wet drawing: The copper-plated wire after electroplating is subjected to several passes of wet drawing by using a reversing water tank wire drawing machine. ;

(5) Embodiment 3 provides the same wire stress relief device as in Embodiment 1, and uses the wire stress relief device to perform stress relief and straightening on the finished wire diameter steel wire. Specifically, as shown in FIG. 1 , the finished wire diameter steel wire travels through the guide wheel 6 to the heating coil 3 for heating to eliminate residual stress, and then continues to travel to the straightener 1 for wire straightening. One side of the straightener 1 is provided with The air-cooled chip removal device 2 can remove the impurities on the surface of the steel wire, the constant tension automatic control system 5 provided at the rear end of the straightener 1 performs tension control, and finally the wire is taken up by the take-up I-shaped wheel. Among them, the heating power of the heating coil 3 is 82W; the ratio of the straightening roller groove width of the straightener 1 to the diameter of the finished steel wire is 4, the ratio of the groove depth to the diameter of the finished steel wire is 2, and the number of bearings is 17; constant tension The tension of the automatic control system 5 is controlled at 1.4 kg.

The performance detection after aging is carried out to the monofilament steel cord manufactured by embodiment 3 and the traditional monofilament steel cord produced by the twisting strand process, and the test results are as follows in Table 3:

Table 3 embodiment 3 monofilament steel cord performance index comparison table

item/average	Bow height/mm	bow height standard deviation	Breaking force/N
Example 3	7	1.17	311
Tradition	9	2.06	308

It can be seen from Table 3 that the 1×0.40NT monofilament steel cord produced in the embodiment of the present invention has the same bow height and average breaking force as the traditional one.

To sum up, the method for manufacturing a monofilament steel cord and the steel wire stress relief device provided by the present invention do not go through the stranding process after the wet drawing process, and the residual stress of the monofilament steel cord is eliminated by the steel wire stress relief device, thereby improving the performance of the steel cord. Product quality and production efficiency, reducing manufacturing costs.

The above are only the preferred embodiments of the present invention. It should be pointed out that for those skilled in the art, without departing from the technical principle of the present invention, several improvements and modifications can also be made. These improvements and modifications It should also be regarded as the protection scope of the present invention.

Claims (10)

1. A wire stress relieving device is characterized in that it includes a heating coil and a straightener, the heating coil and the straightener are arranged in sequence along the wire conduction direction, and an air-cooled chip removal device is provided on one side of the straightener.
2. The wire stress relief device according to claim 1, characterized in that, along the direction of wire conduction, the front end of the heating coil is provided with a traction plate, and the rear end of the straightener is provided with a constant tension automatic control system.
3. The wire stress relief device according to claim 2, wherein guide wheels are provided between the traction plate and the heating coil, between the heating coil and the straightener, and at the rear end of the straightener.
4. A method for manufacturing a monofilament steel cord, comprising the following steps:

   The wire rod is mechanically peeled, then cleaned, coated with boron and then dried;

   Use a straight-forward wire drawing machine to perform several passes of dry drawing to obtain dry drawn steel wire;

   Heat treatment and cooling of the dry drawn steel wire, followed by pickling, copper plating and galvanizing, medium frequency thermal diffusion, phosphating, water washing and soap drying;

   The copper-plated wire after electroplating is wet-drawn for several passes by using a reversing water tank wire drawing machine to obtain the finished wire diameter wire;

   The wire stress relief device according to any one of claims 1-3 is used for stress relief and straightening of the finished wire diameter steel wire, and the wire is taken up by a wire take-up I-shaped wheel.
5. The method for manufacturing a monofilament steel cord according to claim 4, wherein the carbon content of the wire rod is 0.55-1.05%, and the diameter is 5.0-7.5 mm.
6. The method for manufacturing a monofilament steel cord according to claim 4, wherein the diameter of the dry drawing steel wire is 0.82-3.0 mm; The steel wire is subjected to intermediate heat treatment and then dry-drawn for several passes to obtain dry-drawn steel wire.
7. The method for manufacturing a monofilament steel cord according to claim 4, characterized in that, the thickness of the coating layer after copper plating of the dry drawn steel wire is 0.10-0.50 μm, and the content of copper is 60.5-66%.
8. The method for manufacturing a monofilament steel cord according to claim 4, wherein the wet drawing speed is 0.5-17 m/s, and the diameter of the obtained finished wire diameter steel wire is 0.15-0.50 mm.
9. The method for manufacturing a monofilament steel cord according to claim 4, wherein the specific step of stress relief of the finished wire diameter wire comprises: first heating the wire through a heating coil, and then aligning the wire through a straightener.
10. The method for manufacturing a monofilament steel cord according to claim 9, wherein the heating power of the heating coil is 1-300W; the ratio of the straightening roller groove width of the straightening device to the diameter of the finished steel wire is 1-10, the ratio of groove depth to finished steel wire diameter is 0.5-10; a constant tension automatic control system is set at the rear end of the straightener for tension control, and the tension of the constant tension automatic control system is controlled at 0.5- 2kg.

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