RU2464136C2 - Electrode tool for electrochemical broaching of metal parts - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to machine building and may be used for broaching whatever metal parts. Proposed electrode tool comprises flexible working part with electrolyte feed holes to be connected to generator negative pole and rigid support connected via piezoconverters to power supply, said piezoconverters being provided with pushers arranged along normal to flexible part sections. Said piezoconverters consist of piezoelement pushers connected in series and extending toward pusher axes, piezoelement number in every piezoconverters being at least not smaller than ratio between flexible part maximum travel along pusher axis and ultimate variation of extension of every piezoelement in the same direction.

EFFECT: expanded broaching performances, higher surface quality.

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Description

The present invention relates to the field of mechanical engineering and can be used to expand the technological capabilities of electrochemical dimensional processing when receiving cavities in metal parts from any kind of workpieces, for example, in the manufacture of a working profile of molds, forging dies, piercing cavities of variable cross-section.

Known electrode tool [1] with a non-rigid construction of the working part. The disadvantages of the known device include the need for additional (relative to the working) movement for uniform processing, the inability to remove large allowances, which limits the scope of its use when flashing cavities.

Known electrode tool [2] for flashing cavities with a flexible working part of metal with a memory effect. The disadvantage of this device is a stepwise 1-3-fold one-sided shape change without the ability to control the profile of the working part during the processing period.

Known electrode tool [3] with a flexible bimetallic working part, which changes shape when local heating due to the difference in thermal expansions of its constituent layers. The disadvantage of this device is the low accuracy of processing due to the low accuracy of controlling the movements of the bimetallic working part.

Closest to the claimed invention is an electrode tool [3].

The proposed electrode tool allows controlled movement of its flexible working part (movement, vibration, shape change, as well as a combination of these effects), which expands the technological capabilities of electrochemical dimensional processing when receiving cavities in metal parts. This is achieved by the fact that the electrode tool for electrochemical flashing of a cavity in a metal part contains a flexible working part with holes for supplying electrolyte connected to the negative pole of the generator, and a hard spar connected via piezoelectric transducers connected to the current source with rigid pushers installed normal to sections of the flexible working part. Piezoelectric transducers consist of piezoelements connected in series and expanding in the direction of the axes of the pushers, the number of which in each piezoelectric transducer is not less than the ratio between the limiting movement of the flexible working section in the direction of the pusher axis and the limiting change in the expansion of each piezoelectric element in the same direction.

The figure shows the construction of the electrode tool.

The electrode-tool contains a flexible working part 1, cavity 2 and elastic elements 3. Inside the cavity 2 there is a spar 4 on which piezoelectric transducers 5 are placed, the number of which is chosen experimentally depending on the shape of the cavity 2 and the processing technological parameters. Piezoelectric transducers 5 are connected to rigid pushers 6, acting on the flexible working part 1 and allowing its controlled movement.

Piezoelectric transducers 5 consist of piezoelectric elements connected in series (not shown in the figure), expanding in the direction of the axes of the pushers 6, and the number of piezoelectric elements for each piezoelectric transducer 5 take no less than the ratio between the limiting movement of the portion of the flexible working part 1 in the direction of the axis of the pusher 6 and the limiting change in the expansion of each piezoelectric element in the same direction. To the piezoelectric transducers 5 through the regulator 8 using current leads 7 supply current from the current source 9. The flexible working part 1 is connected to the negative pole of the generator 10 of the machine. To supply the electrolyte in the flexible working part 1, holes 11 are provided.

The electrode tool works as follows. When the power is off from the generator 10 and the electrolyte is supplied, an electrode-tool with a flexible working part 1 is installed in the initial position, which is determined during the design of the technological process of processing. Turn on the supply of electrolyte through the cavity 2 and openings 11, connect the flexible working part 1 to the negative pole of the generator 10. Using the regulator 8, change the magnitude of the current from the current source 9, which allows the controlled movement of the flexible working part 1 due to the expansion or contraction of the piezoelectric elements in piezoelectric transducers 5, the elasticity of the elements 3 and the intrinsic elasticity of the flexible working part 1. The number of piezoelectric elements in the piezoelectric transducer 5 take no less than the ratio between the limiting movement of the flexible work section whose part 1 in the direction of the axis of the pusher 6 and change the limit of expansion of each piezo element (taken from [4] for the selected material) in the same direction. From the same source [4] select the magnitude of the pressure force of the piezoelectric elements on the pushers 6.

An example application of the invention. In X12M steel, a cavity is required to insert a forging die having a transverse dimension of 47 mm and a cavity depth of 17.5 mm. We put on the drawing cavity cross-sections parallel to the one considered through 30-35 mm. With a cavity length of 175 mm the number of sections is 5. Piezoelectric elements made of ceramics allow you to get the maximum movement due to the piezoelectric effect of 0.4-0.45 mm. To deepen by 17.5 mm, a set of 44 piezoelectric elements is required, which ensures the movement of the pushers in the considered section in the direction of the working part made of brass L61 with a sheet thickness of 1 mm. The number of pushers in the section of the cavity, determined experimentally, should be equal to 3, which ensures smooth conjugation in it of the profile of the working part until the desired depth of the cavity is reached (in the considered section with the greatest depth). According to the drawing, the cavities make a map of the maximum displacements of all pushers for each section. According to information about the processing depth at the locations of all pushers and for each of them, the number of piezoelectric transducers is calculated, which will need to be connected to the current source until the cavity depth is obtained at all points opposite to the pushers.

At the beginning of processing, all the pushers are in the initial position, holding the flexible working part parallel to the cavity of the part until processing. After a 30-second cycle of processing, the controller sends a command to the current source, from where the current flows to the piezoelectric transducers, which move the pushers by the amount of movement from the first piezoelectric elements in each piezoelectric transducer. If the current supplied to the flexible working part starts to increase, then the cycle time of the regulator is increased until the initial current value is reached. Otherwise, they reduce it. During processing of the cavity, the number of connected piezoelectric elements in all piezoelectric transducers is proportional to the depth of the cavity opposite each pusher until the last piezoelectric element is connected in the piezoelectric transducer, which acts on the pushers with the greatest displacement. After stopping the movement of the flexible working part in areas where the action of the pushers has ended, the treatment of these sections with anodic dissolution attenuates due to an increase in the interelectrode gap (between the flexible working part and the cavity) to an established value and a cavity shape corresponding to the drawing is formed. In this example, the cavity processing time was about 20 minutes, which is an order of magnitude shorter than on profile copy milling machines.

Information sources

1. Auth. testimonial. No. 265334, bull. fig. No. 10, 1970.

2. Auth. testimonial. No. 737186, bull. fig. No. 20, 1980.

3. Auth. testimonial. No. 841891, bull. fig. No. 24, 1981.

4. Glozman I.A. Piezoceramics. M .: Energy, 1972 - 288s.

Claims (1)

An electrode tool for electrochemical flashing of a cavity in a metal part, containing a flexible working part with holes for supplying electrolyte, connected to the negative pole of the generator, and a hard spar connected through piezoelectric transducers connected to the current source with rigid pushers installed normal to the sections of the flexible working part , while the piezoelectric transducers consist of piezoelement pushers consecutively connected and expanding in the direction of the axes, the number of which in each ezopreobrazovatele not less than the ratio between the movement limiting portion of the flexible working portion in the direction of the pusher axle and limiting a change in extension of each piezoelectric element in the same direction.

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