CN103306611B - Special-shaped drill rod used for coal mining and processing technology of drill rod - Google Patents

Abstract

The invention discloses a special-shaped drill rod used for coal mining and a processing technology of the drill rod. The special-shaped drill rod used for the coal mining comprises a drill rod body provided with a small regular hexagon inner hole, wherein the appearance of the drill body adopts a large regular hexagon, corners of the large regular hexagon and the small regular hexagon are arc-shaped, a distance between every two opposite sides of the large regular hexagon ranges from 20 mm to 30 mm, and the wall thickness of the drill rod body ranges from 3 mm to 4mm. The special-shaped drill rod disclosed by the invention is manufactured by adopting an integrated type seamless structure and a cold drawing technology, and the size accuracy of a product can be effectively controlled; and meanwhile, a thermal refining processing for heating through automatic flowing water superaudio frequency induction is adopted, so that the heating speed is high, the time is short, the processing is simple, the effect is good, the product hardness can be improved, the product stability is enhanced, and the service life of the product is prolonged.

Description

Special-shaped drill pipe for coal mining and its processing technology

technical field

The invention relates to the field of machinery, in particular to a special-shaped drill pipe for coal mining and its processing technology.

Background technique

Special-shaped drill pipes for coal mining are mining consumable tool accessories. The existing special-shaped drill pipes for coal mining mainly include conventional drill pipes such as round drill pipes and square drill pipes. This type of drill pipe has certain limitations in use. Its drilling speed, drilling efficiency and drilling performance are not as good as special-shaped drill pipes. Therefore, special-shaped drill pipes have gradually developed in recent years.

At present, the manufacture of these special-shaped drill pipes is formed by hot-rolling or cold-rolling forging process, which has low dimensional accuracy and cannot be effectively controlled; and its heat treatment process is completed by traditional quenching process, and the heating time is long , The hardness control effect of the product is poor, resulting in poor product stability and low service life.

Contents of the invention

The technical problem mainly solved by the present invention is to provide a special-shaped drill pipe for coal mining and its processing technology, which can effectively control the dimensional accuracy of the product, and the processing technology is simple, fast, short, and effective, and can improve the hardness of the product and strengthen the Product stability, prolong product life.

In order to solve the above technical problems, a technical solution adopted by the present invention is to provide a special-shaped drill pipe for coal mining, including: a drill pipe body with a small regular hexagonal inner hole, and the shape of the drill pipe body is a large regular hexagon shape, and each corner of the large regular hexagon and the small regular hexagon is arc-shaped, the distance between the two opposite sides of the large regular hexagon is 20-30mm, and the wall thickness of the drill pipe body is 3-4mm.

In a preferred embodiment of the present invention, each dimensional accuracy of the drill rod body is ±0.02mm.

In a preferred embodiment of the present invention, the material of the drill pipe body is 30CrMo.

In a preferred embodiment of the present invention, the hardness of the drill pipe body is HRC39-41.

The processing technology of above-mentioned special-shaped drill pipe for coal mining comprises the following steps:

1) Fix the special-shaped drill pipe blank after hot rolling and cold rolling on the cold drawing machine, and select the inner hexagonal floating inner mold and fixed outer mold;

2) Cold drawing: maintain the coaxiality between the special-shaped drill pipe, the hexagonal movable inner mold and the fixed outer mold, so that the inner hexagonal movable inner mold can extrude a small regular hexagonal inner hole at the concentric position of the special-shaped drill pipe , and the fixed outer mold extrudes the large regular hexagonal shape of the drill pipe body, and ensures the position of the small regular hexagonal inner hole relative to the large regular hexagonal shape of the drill pipe body;

3) Quenching and tempering: The finished special-shaped drill pipe after cold drawing is sent to the automatic flowing water super audio frequency induction unit for quenching and tempering treatment.

In a preferred embodiment of the present invention, the hexagonal inner mold includes a head, a shank, and a tapered transition section connecting the head and the shank, wherein the shank is provided with In the internally threaded hole, the material of the head and the tapered transition section is tungsten steel, and the material of the handle is 45# steel.

In a preferred embodiment of the present invention, the taper of the tapered transition section is 12°-13°.

In a preferred embodiment of the present invention, the specific method of the tempering treatment described in step 3) is as follows:

a. Send the finished special-shaped drill pipe to the heating coil of the automatic flowing water super-audio frequency induction unit, and preheat it at a temperature of 840°C-895°C for 10-12 seconds;

b. Then heat the special-shaped drill pipe at a temperature of 880°C-915°C;

c. Then use cooling device to cool the special-shaped drill pipe.

In a preferred embodiment of the present invention, step c adopts a cooling method of spraying water on the outer surface of the drill pipe body and flushing the inner hole with water.

The beneficial effect of the present invention is that: it adopts an integrated seamless structure and is manufactured by cold drawing technology, which can effectively control the dimensional accuracy of the product, and adopts the tempering treatment process of automatic flowing water super-audio frequency induction heating, with fast heating speed and short time. The process is simple, the effect is good, the hardness of the product can be improved, the stability of the product can be enhanced, and the service life of the product can be prolonged.

Description of drawings

Fig. 1 is a structural representation of a preferred embodiment of a special-shaped drill pipe for coal mining of the present invention;

Fig. 2 is the structural representation of the inner hexagonal movable inner mold used when the special-shaped drill pipe shown in Fig. 1 is cold drawn;

The marks of each part in the accompanying drawings are as follows: 11, drill pipe body, 12, inner hole, B, the distance between two opposite sides of a regular hexagon, δ, wall thickness, 21, head, 22, shank, 221, internally threaded hole, 23, tapered transition section, α, taper.

Detailed ways

The preferred embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, so as to define the protection scope of the present invention more clearly.

Please refer to Fig. 1 and Fig. 2, the embodiment of the present invention comprises:

Raw materials: special-shaped drill pipe blanks made of 30CrMo after hot-rolling and cold-rolling

Equipment: cold drawing machine, automatic flow super audio frequency induction unit, cooling device

Processing technology:

1) The special-shaped drill pipe blank made of 30CrMo after hot rolling and cold rolling is fixed on the cold drawing machine, and the hexagonal inner mold and fixed outer mold are selected;

Wherein, the hexagonal inner mold includes a head 21, a handle 22, and a tapered transition section 23 connecting the head 21 and the handle 22, and the handle 22 is provided with an inner Threaded hole 221, the material of the head 21 and the tapered transition section 23 is tungsten steel, the material of the handle 22 is 45# steel, and the taper α of the tapered transition section is 12°-13° , preferably 13°.

2) Cold drawing: maintain the coaxiality between the special-shaped drill pipe, the hexagonal movable inner mold and the fixed outer mold, so that the inner hexagonal movable inner mold can extrude a small regular hexagonal inner hole at the concentric position of the special-shaped drill pipe 12, and the fixed outer mold extrudes the large regular hexagonal shape of the drill pipe body 11, and ensures the position of the small regular hexagonal inner hole 12 relative to the large regular hexagonal shape of the drill pipe body 11;

3) Send the finished special-shaped drill pipe after cold drawing to the automatic flowing water super audio frequency induction unit for quenching and tempering treatment. The specific method of quenching and tempering treatment is as follows:

a. Send the finished special-shaped drill pipe to the heating coil of the automatic flowing water super-audio frequency induction unit, and preheat it at a temperature of 840°C-895°C for 10-12 seconds;

b. Then heat the special-shaped drill pipe at a temperature of 880°C-915°C;

c. Then use the cooling device to cool the special-shaped drill pipe, and adopt the cooling method of spraying water on the outer surface of the drill pipe body 11 and flushing the inner hole 12 with water.

The automatic flowing water super-audio frequency induction unit is designed and manufactured by our company (Changshu Special-shaped Steel Pipe Co., Ltd.), and the patent number is ZL201120176354.3, which is a special-shaped drill pipe heat treatment device.

The special-shaped drill pipe for coal mining produced by the present invention includes a drill pipe body 11 with a small regular hexagonal inner hole 12, the shape of the drill pipe body 11 is a large regular hexagon, and the large regular hexagon and the small regular hexagon Curved at all corners, it can be designed in a variety of sizes, such as:

B(mm) δ(mm) 22.22 3.11 28.58 3.915

Wherein, B is the distance between two opposite sides of the large regular hexagon of the drill pipe body 11; δ is the wall thickness of the drill pipe body 11.

The dimensional accuracy of the drill rod body 11 is controlled within the range of ±0.02mm, and the surface hardness of the drill rod body 11 is controlled within the range of HRC39-41.

The invention discloses a special-shaped drill pipe for coal mining and its processing technology. It adopts an integrated seamless structure and is manufactured by cold drawing technology, which can effectively control the dimensional accuracy of the product, and adopts automatic flowing water super-audio frequency induction heating for tempering. The treatment process has fast heating speed, short time, simple process and good effect, which can improve the hardness of the product, enhance the stability of the product and prolong the service life of the product.

The above is only an embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the description of the present invention and the contents of the accompanying drawings, or directly or indirectly used in other related technologies fields, all of which are equally included in the scope of patent protection of the present invention.

Claims (5)

1. a processing technology for coal mining special-shaped drilling rod, is characterized in that, comprises the following steps:

1) by hot rolling, cold rolling after special-shaped drill rod blank fixing on drawbench, choose interior hexagonal and to move about internal mold and fixing external mold;

2) cold-drawn: keep the axiality that special-shaped drill rod and interior hexagonal are moved about between internal mold, fixing external mold, the interior hexagonal internal mold that moves about is made firmly to extrude little regular hexagon endoporus at the concentric position of special-shaped drill rod, and fixing external mold squeezes out the large regular hexagon profile of drilling rod body, and guarantee the position degree of little regular hexagon endoporus relative to the large regular hexagon profile of drilling rod body;

3) modified: the finished product special-shaped drill rod after cold-drawn to be delivered to automatic streamline superaudio induction unit and carry out modifier treatment.

2. the processing technology of coal mining special-shaped drilling rod according to claim 1, it is characterized in that, the described interior hexagonal internal mold that moves about comprises head, shank and connects the tapering transition section of described head and described shank, wherein, described shank is provided with internal thread hole, the material of described head and described tapering transition section is wolfram steel, and the material of described shank is 45# steel.

3. the processing technology of coal mining special-shaped drilling rod according to claim 2, is characterized in that, the tapering of described tapering transition section is 12 °-13 °.

4. the processing technology of coal mining special-shaped drilling rod according to claim 1, it is characterized in that, the concrete grammar of the modifier treatment described in step 3) is as follows:

A. finished product special-shaped drill rod is delivered to the heater coil place of automatic streamline superaudio induction unit, first preheat at 840 DEG C of-895 DEG C of temperature, keep 10-12 second;

B. then at 880 DEG C of-915 DEG C of temperature, special-shaped drill rod is heated;

C. cooling unit is used to cool special-shaped drill rod subsequently.

5. the processing technology of coal mining special-shaped drilling rod according to claim 4, is characterized in that, described step c adopts and sprays water to the external surface of drilling rod body, the cooling means of endoporus bath.