RU1790638C - Device for electrochemical treatment of cavities of long-size items - Google Patents

Abstract

Usage: the invention relates to the electrochemical treatment of cavities of long products, mainly pipes with internal diameters of 3-8 mm, during electrochemical polishing and plating, and can be used in metallurgy, mechanical engineering, and the radio engineering industry. The essence of the invention lies in the fact that the device is provided with an additional electrode 1 with individual means of movement 6, as well as an insulated current lead 4 and a seal, the electrodes being connected to each other and the seal mounted on the side of the electrolyte supply means. 1 s, item f-crystals, 3 ill.

Description

Fig 7

1Vemkosl7b

Jvj

8

0

 00

with

 with

The invention relates to the electrochemical treatment of cavities of long products, mainly pipes with internal diameters of 3-8 mm, during electrochemical polishing and plating and can be used in metallurgy, mechanical engineering and the radio engineering industry

Known devices for electrochemical polishing of pipes moving relative to a fixed perforated cathode, to which a current is supplied through a tube, electrically insulated from the outside. An electrolyte is supplied through this pipe to the cavity of the tube to be treated. These devices are widely used in the industry for processing pipes with an inner diameter of at least 8 mm, since at smaller diameters through the tubular current supply it is impossible or very difficult to supply sufficient currents. In addition, the disadvantages of these known devices include their large length, difficulties in draining acidic electrolyte from the ends of pipes moved over a long length, and the inability to use uneven pipes or pipes with curved sections for processing cavities.

Closest to the proposed solution in terms of technical nature and the achieved effect is a known device for electrochemical processing of cavities of long products. This device with a movable electrode inside a rigidly fixed cavity, a flexible insulated continuous current supply and with the injection of electrolyte into the cavity using a stationary means with individual sealing of each product, taken as a prototype, provides processing not only rectilinear, but also curved long products with high productivity due to the possibility of creating high current densities. In addition, this device is compact and provides better working conditions due to the possibility of compact placement of ventilation exhausts from one end of the processed pipe.

The disadvantages of the prototype in relation to the problem of processing cavities with small diameters are:

the limited length of the processed pipes due to the impossibility of supplying currents of the required strength, due to the heating of flexible current leads and the difficulty of ensuring the flow of electrolyte with the release of gases;

low productivity due to the separation of the process into the period of the electrode task without connecting current (idle period) due to the inability to use rigid insulators for the task of flexible current supply and the working period with the current supply during the reverse electrode stroke. In addition, the low productivity of processing is associated with the time required for an auxiliary operation — pulling the yarn to capture and task the electrode inside the cavity, since feeding sections of a flexible and inelastic insulated wire of small diameter through the end of the article is impossible even with a cavity length of 1 m.

The aim of the invention is to increase the range of products to be processed along the length by supplying a current with twice the strength without overheating of the current leads and increasing productivity.

This goal is achieved in that a device for electrochemical processing of cavities of long products, containing stationary means for supplying electrolyte, means for securing products with a current lead, an electrode with an insulated current lead, made flexible and continuous in cross section, and means for moving the electrode inside the treated cavity, installed with the ability to change the direction of its movement is equipped with an additional electrode with an individual means of movement, isolated th current supply and the seal, wherein the electrodes are connected with each other, and the seal is established by the electrolyte supply means.

In addition, the device is provided with means for dragging the electrode through the cavity to be machined, made in the form of a carriage with a magnet and a coupling made of magnetic material, the coupling being mounted for connection with the electrode.

Figure 1 is a General view of the device; in Fig.2 - section aa in Fig.1; in Fig.Z - section bB in Fig.1.

The device consists of a pump with a capacity (not shown in Fig. 1), two electrodes 1 with insulators 2 and hooks (or other connecting means) 3, two soldered to the electrodes flexible insulated current leads (wires) 4, non-drive rollers 5 , two drums 6 with drives and means for disconnecting the drives from the drums (not shown in FIG. 1), an electrolyte supply housing 7 with a supply from an electrolyte pump, a clamping nut 8 with a gasket 9 (made of rubber or other polymeric material), a seal consisting of a nut 10 s gasket 11 and shavings of

polymer material (for example, fluoroplastic) 12, a drain chute 13 with a funnel, current-supply lodges 14 with pressure springs (not shown in Fig. 1), a movable carriage 15 with a permanent magnet (or electromagnet) 16, means for supplying a direct current direct current miter, busbars with an approach to current-carrying tool holders 14 and to drum 6 (not shown in FIG. 1). The device is equipped with a removable coupling made of magnetic material (not shown in Fig. 1).

The device operates as follows. Before setting the processed lengths of the numbered tube product 17, the direct current and the pump are turned off, the electrodes 1 are disconnected and in the extreme positions: the left electrode 1 is in the cavity of the housing 7 (position ab), and the right electrode 1 is in the drain trough 13 ( position vg). The movable carriage 15 with magnet 16 is in the extreme left position at position e.

The pipe 17 is installed on the current leads-lodges 14, the left electric is introduced into the cavity of the pipe 17 from the side of the left end. the cable 1 and is pulled through the pipe with the left drum drive 6 turned off. The electrode 1 is pulled through the pipe either with a magnet 16 and a removable coupling made of magnetic material (I method) or with a thread pulled through the pipe cavity in advance (outside the device) ( II method). According to the first method, which is suitable for processing pipes of non-magnetic material, the coupling with the hook engages with the hook 3 of the electrode 1 and is inserted into the pipe. After that, the movable carriage 15 with the magnet 16 is turned on and moves over the pipe 17 to the extreme right position. this coupling of magnetic material under the action of a magnet moves to a position, dragging an electrode 1 with a flexible current lead 4. The coupling has an arbitrary shape, equipped with a hook and one or more rollers (balls) to reduce friction with the pipe . After reaching position e, the hitch is separated from the electrode 1.

In the second method, when processing pipes of magnetic material, a thread is attached to the hook 3 of the electrode 1 and with its help, the electrode 1 is manually pulled through the pipe to position e, after which the thread is unbound.

After the electrode 1 reaches the position, the e left end of the pipe 17 is inserted into the housing 7 until it stops through the seal 9 and is clamped with the clamping nut 7.

The pipe 17 is pressed against the current leads-clamps 14 by pressure springs, and the left and right electrodes 1 are engaged using hooks 3. After these operations, the process of electrochemical processing is carried out.

Electrochemical processing is as follows. The electrolyte pump and electrolyte are turned on.

0 is pumped through the housing 7 and the cavity in the space between the pipe 17, the electrodes 1 and the flexible current leads 4. The electrolyte from the pipe 17 freely flows into the drain trough 13 and through the funnel into the container

5 with means for heating the electrolyte and maintaining the working temperature, then the drive of the left drum 6 is turned on and the movement of two electrodes 11 is started, dragged by the left flexible current supply 4. During the movement, the electrochemical treatment of the cavity is performed on the pipe section opposite the electrodes 1. When the left electrode reaches position 1 ab the drive of the left drum 6 is switched off5 and the drive of the right drum 6 is turned on, the electrodes 1 are moved from left to right to position e. In this case, electrochemical processing is performed at the return stroke. Then drive the right drum 6

0 turns off, current turns on and the pump stops. The electrolyte flows out of the cavity of the pipe 17 due to the general tilt of the device towards the drain trough 13 (for example, with a slope of 1:10).

5After the end of the electrochemical treatment, the electrodes 1 are disengaged, the drives of both drums 6 drag the electrodes 1 to the extreme positions (left - to position ab and right - to position vg) and

0 are turned off, the carriage 15 moves to the far left to position d, the clamping nut 8 is loosened, the tube 17 is released from the pressure springs and removed from the device for conducting outside

5 washing and drying devices.

By varying the drums 6 on and off, the electrodes 1 are stopped for a predetermined time to uniformly treat the cavities at the ends of the pipe.

Non-driven rollers 5 in the device contribute to more intensive cooling of flexible insulated current leads 4.

Days of increased productivity

5 of the processing, it is possible to install several threads of devices (3-8), which can be serviced by one operator.

The proposed technical solution was tested during electrochemical polishing of the inner cavity of pipes with a diameter

6x1 from stainless steels of grades Х18Н10Т and 02X18Н011 up to 4 m long, providing a surface with a roughness index Ra in the range of 0.06-0.32 microns.

Processing mode: (electrode moving speed 150-200 mm / min, electrode length 55 mm, current 3.5 A, anodic current density 50 A / dm, solution temperature, flexible current supply from wire grade MS-16-13 cross-section 0, 2 mm, forward and reverse under current.

In the device according to the prototype, by pulling the electrode through the cavity with a thread (idle), it was possible to process the pipes under the same conditions, but with a pipe length of not more than 2 due to strong heating of the wires. 40-45 min were spent on processing one pipe 2 m long in one pass (of which 30 min on auxiliary operations). Those. 20-22.5 minutes were spent on processing 1 linear meter in the device according to the prototype

When processing pipes with a length of 4 m in one pass of the electrodes back and forth on the proposed device spent 50-55 minutes, i.e. 12.5-14 minutes were spent on processing 1 linear meter, i.e. processing productivity increased by 45-60% (without taking into account the improvement in quality due to a double stroke).

An even further increase in productivity, the proposed technical solution allows, if necessary, to achieve 2-4 processing passes to achieve the desired quality.

Thus, the proposed device allows to increase productivity by 45-60% or more by doubling the machined portion of the cavity and reducing the time required for auxiliary operations by moving the coupled electrodes and lengthening the machined cavity, as well as doubling the workpiece by two independent supply systems current at the same current density per section of each electrode.

The proposed device can be used on an industrial scale in the production of pipes with a diameter of 5x1 mm,

5x0.5 mm, 6x1 mm, 8x1 mm, 10x1.5 mm with an increased requirement for surface quality by roughness and with obtaining a shiny surface for transportation of highly pure substances in the radio engineering and other industries (clean room problem).

The proposed technical solution can be used when applying galvanic coatings to the internal cavity of pipes for the nuclear industry (with insoluble or temporary soluble anodes), as well as for processing pipelines with curved sections,

Claims (2)

1. Device for electrochemical processing of cavities of long products mainly with small diameters, containing stationary means for supplying electrolyte, means for securing products with a current lead, an electrode with an insulated current lead, made flexible and continuous in cross section, means for moving the electrode inside the treated cavity, installed with the possibility of changing the direction of its movement, different the fact that, in order to increase the nomenclature of the processed products along the length, by supplying a current of twice the strength without overheating of the current leads and increasing productivity, it is equipped with an additional electrode with an individual means of movement, insulated current lead and a seal, and the electrodes are connected to each other, and the seal is installed on the side of the means electrolyte supply. 2. The device according to claim 1, with the exception that, in order to increase the productivity of processing products from non-magnetic material, it is equipped with a means dragging the electrode through the cavity, made in the form of a carriage with a magnet and a coupling made of magnetic material, the coupling being mounted with the possibility of connection with the electrode.