RU2742180C1 - Method of rolling a thread and a product made using the method - Google Patents

Abstract

FIELD: metalwork.

SUBSTANCE: invention relates to a method for rolling a thread and a product made using steps of the method for rolling a thread.

EFFECT: reducing the material consumption of products, increasing the strength of the structure and reliability of the structure.

3 cl, 6 dwg

Description

Technology area

The group of inventions relates to the production of sanitary equipment, namely to the design of heat exchange and heat transfer devices, and can be used, in particular, in domestic water supply systems using low pressure pipelines, for example, in the design of household heated towel rails.

State of the art

Methods of making articles for placing hygiene devices for drying the body (for example, towels) thereon and then removing excess moisture by means of heat, i. E. the so-called heated towel rails. According to the totality of the material properties, pipes of various diameters, made of stainless steel, are mainly used for the manufacture of a heated towel rail. A feature of the manufacture of such pipes, which are made of sheet metal by using electric welding, is their rolling with rollers of different calibers, as a result of which the pipe has irregularities and does not have a perfectly circular cross section. In classic threading using a cutter and a die, it is necessary to use pipes with a wall thickness of at least 2 mm, since a small residual wall thickness with a smaller initial thickness leads to a decrease in the reliability of the structure due to corrosion / electrocorrosion, which can lead to its destruction. An example of a complete thread cut into walls greater than 2 mm thick is shown in FIG. 1. The classical method of threading does not allow to reduce the material consumption of the product while maintaining an acceptable level of its reliability.

In the case of another method known from the prior art for rolling (i.e. forming by deformation) threads by means of threaded rollers, it is also not possible to provide the one shown in FIG. 1, a sharp profile in the case of a pipe with walls less than 2 mm thick, since during rolling it is difficult to make the metal fill the entire profile of the thread rolling roller, an incomplete thread is formed (shown in Fig. 2). This circumstance reduces the reliability of the connection, since on an incomplete thread, the nut is held mainly at the ends of the revolving thread elements.

Also known from the prior art is the problem associated with the contact of the end of the threaded pipe and the fitting (in particular, the gasket), as a result of which damage to the fitting and, accordingly, a decrease in the tightness of the connection can occur. To eliminate the noted drawback, rolling of the end section of the pipe is usually used, i.e. deformation of the material of the end section in the radial direction, followed by cutting off a part of the material.

As the closest analogue of the proposed group of inventions, a well-known decision can be made, according to which, in the manufacture of a heated towel rail, the thread is rolled onto a pipe and subsequent rolling (RU 2013112703 A, 09/27/2014). However, the known method does not show how it is possible to overcome the above obstacles when rolling threads on pipes with a wall thickness of less than 2 mm, and it is also not shown by what means it is possible to carry out the steps of the method (the reference to the use of "non-standard equipment" does not disclose such means, and is also the basis for the conclusion about the increased labor costs in the implementation of the known method due to the need for the initial manufacture of such equipment).

The proposed group of inventions is aimed at overcoming the noted disadvantages of the prior art and allows the achievement of technical results that will be understandable to a specialist on the basis of the information set forth in the following sections of the description.

Disclosure of invention

The following is information disclosing a group of inventions in a preferred embodiment, which is not intended to limit the scope of the claimed legal protection. Within the framework of this application, it is assumed that the presented examples of implementation are made for illustrative purposes and the specialist will understand that the group of inventions can also be used in related fields of the prior art. For example, an indication of the use of the proposed method for the manufacture of a heated towel rail does not mean limiting the use of the invention to this type of product. With the same efficiency, the proposed method can be used in the manufacture of products (or their components) that involve the use of pipes with a threaded connection, for example, when laying a heating system in a country house, transporting substances in any technological process, and the like.

Terms used when disclosing a technical solution:

Product - a product that is made from a cylindrical pipe with a threaded connection according to the described method.

Rotary clamp - a device designed to secure the workpiece, and having the ability to rotate around one axis of rotation and move along the axis of rotation of the thread rolling head. The axis of rotation of the movable clamp is perpendicular to the axis of rotation of the thread rolling head.

At the machine feed - simultaneous synchronized translational movement of the rotary clamp with the workpiece towards the thread rolling head along the axis of rotation of the thread rolling head and rotation of the thread rolling head, and the speed of the translational movement of the rotary clamp is equal to the thread pitch per one revolution of the thread rolling head.

On the reverse feed of the machine - simultaneous synchronized translational movement of the rotary clamp with the product from the thread rolling head along the axis of rotation of the thread rolling head and rotation of the thread rolling head in the opposite direction, and the speed of the translational movement of the rotary clamp is equal to the thread pitch per revolution of the thread rolling head.

Dorn - a cylindrical metal solid part, the diameter of which is less than the inner diameter of the product by no more than 1 mm.

A product branch pipe is a product design element that has an external thread and is intended for a detachable threaded connection with a counterpart.

Drill-milling cutter - a drill that has an end milling part located around the drill at some distance from the shank.

According to the proposed solution, a method of thread rolling is claimed, according to which, in a preferred embodiment, the product 1 is fed into the rotary clamp 2 in the desired position, namely, the end of the workpiece pipe 3 to be processed is directed towards the thread rolling head 4. When installing the product 1 in the rotary clamp 2, also ensure the alignment of the processed branch pipe 3 of the item 1 and the thread rolling head 4. Then the item is fixed in the rotary clamp 2.

At the next step, through the thread rolling head 4, coaxially with the branch pipe 3 of the article 1, the mandrel 5 is extended towards the rotary clamp 2 with a protrusion from the thread rolling head 4. The mandrel feed mechanism is transferred to the movement mode with adjustable resistance.

Then, at the feed of the machine, the thread is rolled on the outer surface of the branch pipe 3. The core 5 is compressed in the branch pipe 3 of the product 1 by reducing the diameter of the product during rolling. In the process of thread rolling, the depth of entry of the branch pipe 3 into the thread rolling head 4 is monitored. When the required depth of entry is reached, the process of thread rolling is stopped. Reverse feed of the workpiece is carried out simultaneously with the reverse rotation of the thread rolling head 4. After the thread rolling head 4 is removed from engagement with the workpiece, the mandrel 5 is forcibly released from the workpiece, after which the movement of the workpiece continues to its original position. Rotary clamp 2 with the workpiece is rotated around the axis of rotation of the clamp 6 at a given angle. At the end of the movement and rotation of the rotary clamp 2, the branch pipe 3 of the product 1 is positioned coaxially with the rolling tool 7.

Then start the rotation of the rolling tool 7 and its translational movement along its axis towards the branch pipe 3 of the product 1. At the moment the rolling tool 7 touches the end of the branch pipe 3, the process of rolling the end begins. End rolling is completed at the moment the rolling tool 7 passes a predetermined distance from the initial position. Then the rolling tool 7 is retracted along its axis to its original position. In the process of retraction of the rolling tool, its rotation is stopped.

Then the rotary clamp 2 with the product 1 is rotated to the next predetermined angle. After turning, the nozzle 3 of the product 1 is positioned coaxially with the drill-cutter 8. The drill-cutter 8 begins to rotate and its translational movement along its axis towards the nozzle 3 of the product 1. At the moment the drill-cutter 8 touches the end of the nozzle 3, the process of drilling and facing of the nozzle 3 begins In this case, the shape of the opening of the inlet nozzle 3 is brought to the shape of a circle and the required diameter of this hole is obtained, as well as the facing of the nozzle 3 after rolling. Drilling and facing ends at the time the drill-cutter 8 passes a given distance from the initial position. Then the drill-cutter 8 is retracted along its axis to its original position. In the process of retraction of the drill-cutter 8, its rotation is stopped.

Then the rotary clamp 2 with the product 1 is turned into a position at which the branch pipe 3 of the product 1 becomes coaxial to the thread rolling head 4. After that, at the machine feed, the thread is finished on the outer surface of the branch pipe 3. At the same time, the depth of entry of the branch pipe 3 into the thread rolling head 4 is controlled. When the required insertion depth is reached, the thread finishing is stopped. After that, on the return feed of the machine, the branch pipe 3 of the product 1 is removed from the thread rolling head 4 and the rotary clamp 2 is returned to its original position.

If the product has one or more branch pipes, then the product is reinstalled and the above operations are repeated for each branch pipe. After completing operations with all branch pipes, the product is removed from the rotary clamp.

Accordingly, as another object of the group of inventions, an article is proposed that can be manufactured using the above method. A heated towel rail can be considered as such a product in a preferred embodiment. It should be noted that within the framework of this application, a product is also understood as an integral part, i.e. a part of the product, mainly representing a pipe, which can be used in the design of both a single product, and be part of a more complex system, in particular, a building heating system.

Brief Description of Drawings

Fig. 1 is a diagram of the thread rolling technology;

Fig. 2 is a sharp thread profile obtained on pipes with a thickness of more than 2 mm by cutting (analogue);

Fig. 3 is an incomplete thread profile obtained on pipes with a thickness of up to 2 mm by rolling (analogue);

Fig. 4 is a profile of a full thread obtained on pipes with a thickness of up to 2 mm by rolling in accordance with the claimed method;

Fig. 5 is a side view of a finished product with a thread made by the claimed method;

Fig. 6 is a section of a finished product with a thread made by the claimed method, 3/4 view from the left.

The next section of the description provides information about an embodiment of the claimed group of inventions, showing by what means and methods it can be implemented, as well as showing what technical effects should be manifested during its implementation.

Implementation of the invention

To implement the proposed method, it is possible to use screw-cutting lathes widely presented in the prior art, which ensures ease and availability of use. The essence of the method lies in the order of operations, as well as in the use of specialized equipment, indicated above. Metallic pipes with a wall thickness of 2 mm or less are considered as objects of influence of the method.

When performing the initial threading, it is proposed to use a cylindrical metal part, within the framework of the application the so-called "mandrel" is a device of simple design, which is inserted into the product at the time of thread rolling. The use of such a part does not allow the pipe to radially deform at the time of thread rolling, and in the usual rolling method, when the thread is rolled, the pipe is subject to constriction, which makes it impossible to roll the thread by means of external pressure. Thus, the use of a mandrel at the time of the primary thread rolling makes it possible for the metal of the product to penetrate into the thin recesses of the thread rolling head. This makes it possible to form threads on thin-walled pipes with an increased profile, close to the profile of a full thread (Fig. 4), which increases the reliability of the connection. In a preferred embodiment, the mandrel is made of high strength hardened steel grades and is threaded on the outer surface to allow it to be inserted and removed from the pipe.

The use of the above-disclosed method for the manufacture of heated towel rails makes it possible to reduce the material consumption of products, as well as to increase the structural strength, tightness and overall reliability of the structure.

It should be noted that the achievement of these technical results is ensured when the steps of the method are performed exactly in the sequence disclosed above, that is, in the way that is characterized by the features of the claims.

Since the proposed method is applicable at the stage of manufacturing products, accordingly, the scope of the proposed solution also includes products that can be manufactured using the method. In a preferred embodiment, towel warmers are considered as such products, the design of which assumes the presence of a threaded connection. However, the specialist will understand that the proposed method can be applied in the manufacture of other types of products, as well as systems in which the use of elements in the form of pipes and their threaded connections, mainly for transferring a heat carrier.

Claims (17)

1. Thread rolling method, according to which the product - is fed into the rotary clamp, and the end of the processed branch pipe of the product is directed towards the thread rolling head, ensuring the alignment of the branch pipe and the thread rolling head, the product is fixed in the rotating clamp, - through the thread rolling head coaxially with the branch pipe towards the rotary clamp, the mandrel is pulled out with a protrusion from the thread rolling head, and the mandrel feed mechanism is switched to the movement mode with adjustable resistance, and the mandrel is moved in the axial direction during compression by the product, - simultaneous synchronized translational movement of the rotary clamp with the product from the thread-rolling head along the axis of rotation of the thread-rolling head and rotation of the thread-rolling head in the opposite direction, and the speed of the translational movement of the rotary clamp is equal to the thread pitch per one revolution of the thread-rolling head, roll the threads on the outer surface of the branch pipe thus, that the mandrel is compressed in the branch pipe by reducing the diameter of the product during knurling, - the depth of entry of the branch pipe into the thread rolling head is monitored, and upon reaching the required depth of entry, the thread rolling process is stopped, - carry out the reverse feed of the product simultaneously with the reverse rotation of the thread rolling head, - after the thread rolling head is removed from engagement with the product, the mandrel is forced out of the product, after which the movement of the product continues to its original position, - the rotary clamp with the product is rotated around the axis of rotation of the clamp at a given angle in such a way that at the end of the movement and rotation of the rotary clamp, the branch pipe of the product is positioned coaxially with the rolling tool, - then the rotation of the rolling tool is started, ensuring its translational movement along its axis towards the product branch pipe, and at the moment the rolling tool touches the end of the branch pipe, the process of rolling the end begins, - end rolling is completed at the moment the rolling tool passes a given distance from the initial position, after which the rolling tool is retracted along its axis to its original position, its rotation is stopped, - the rotary clamp with the product is rotated to the next predetermined angle, the product branch pipe is positioned coaxially with the drill-milling cutter, and the rotation of the drill-cutter and its translational movement along its axis towards the product branch pipe is started, - at the moment the drill-milling cutter touches the end of the nozzle, the process of drilling and facing the nozzle begins, bringing the shape of the opening of the inlet nozzle to a circular shape and obtaining the required diameter of this hole, as well as facing the nozzle after rolling, - drilling and facing end at the moment the drill-milling cutter passes a given distance from the initial position, and then the drill-milling cutter is retracted along its axis to its original position with a one-time stop of rotation, - the rotary clamp with the product is rotated to a position at which the branch pipe of the product becomes coaxial with the thread rolling head, after which by the simultaneous synchronized translational movement of the rotary clamp with the product from the thread rolling head along the axis of rotation of the thread rolling head and rotation of the thread rolling head in the opposite direction, and the speed of translational movement of the rotary clamp is equal to the thread pitch per one turn of the thread rolling head, the thread is refined on the outer surface of the nozzle, monitoring the depth of the nozzle entry into the thread rolling head, - when the required depth of entry is reached, the thread finishing is stopped, after which, on the return feed of the machine, the product branch pipe is removed from the thread rolling head with the return of the rotary clamp to its original position. 2. An article based on a cylindrical pipe with a threaded connection, characterized in that the thread of the threaded connection is made by the method of claim 1. 3. A product based on a cylindrical pipe with a threaded connection according to claim 2, characterized in that it is a heated towel rail.

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