RU2451756C2 - Method of producing box-like structural element from aluminium alloy with cooling channels - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to welding and may be used, particularly, for making electrical machine assembly units. Proposed method comprises assembling the set of box parts with box base part and welding them together. Welding is carried pout to seal heat carrier channels in the box. Then, said box is heated to temperature defined by the following relation: t_H=(0.95÷1.07)_te, and cooled down at the rate of (0.1÷4.7)°C/min, where t_H is box heating temperature; t_e is maximum operating temperature of electrical machine assembly.

EFFECT: higher accuracy of fabricating articles with heat carrier channels.

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Description

The invention relates to the field of welding and can be used, in particular, in the manufacture of components of electrical machines.

From the book of P. Doroshenko in 1972, there is a known method of manufacturing a structural element in the form of a metal case with channels for a heat transfer medium — a heat exchange lattice, including assembling heat exchange tubes with a tube lattice panel and securing them with plastic deformation (see RF Patent No. 2198051, class B21D 39 / 06, publ. 2003, where this information is given).

The disadvantage of this method is the possibility of loss of tightness of the heat exchange circuit during operation.

There is also a known method of manufacturing a structural element in the form of an aluminum alloy body with channels for a coolant, including assembling a set of body parts with its base part and their subsequent welding (see US Pat. No. 2138525, CL 62-126, publ. 1938 - prototype )

The disadvantage of this method is warpage due to significant stresses in the structural element after welding.

The objective of the invention is the prevention of warpage.

The problem is solved in that the method of manufacturing a metal body with channels for the coolant of the assembly of an electric machine made of aluminum alloy includes assembling the body parts with a base part and their subsequent welding. In this case, welding is carried out for sealing in the casing of the channels for the coolant, then the casing is heated to a temperature determined by the dependence: t _n = (0.95 ÷ 1.07) _te , and it is cooled at a speed of (0.1 ÷ 4.7) ° C / min, where

t _n - heating temperature of the housing;

t _e - the maximum operating temperature of the housing unit of an electric machine during operation.

The technical result of the invention is to improve the performance of the node, part of which is a structural element made in this way.

The invention is illustrated by drawings, which show

figure 1 - structural element;

figure 2 is a section aa in figure 1.

Example 1

A structural element (a motor-wheel stator with a diameter of 20 '' of the vehicle) was made in the form of a housing 1, including a base part 2 of heat-treated blanks of an AMG-6 alloy, and a set of parts 3. In the housing 1, channels 4 for the coolant were made. A set of parts 3 is assembled with the base part 2 and welded with seams 5, sealing the circuit 6 for the coolant. After welding, the housing 1 is heated to a temperature of 118 ° C. The maximum operating temperature of the stator of the motor-wheel during its operation is 120 ° C. Then, said body is cooled at a rate of 2.5 ° C./min. Then, the stator housing of the motor-wheel is subjected to finishing machining. After finishing machining with subsequent exposure, the deviation of the diametrical dimensions of the body from the nominal did not exceed 0.22 mm. For the same wheel, made without heating and cooling according to the indicated dependence, the deviations of the diametrical dimensions of the body were 2.7 mm.

Example 2

The same structural element (stator of the motor-wheel of the vehicle) was made, the base part 2 of which was made of heat-treated blanks of alloy AB, and a set of parts 3. In the housing 1, channels 4 for the coolant were made. A set of parts 3 is assembled with the base part 2 and welded with seams 5, sealing the circuit 6 for the coolant. After welding, the housing 1 is heated to a temperature of 123 ° C. The maximum operating temperature of the stator of the motor-wheel during its operation is 120 ° C. Then, said body is cooled at a rate of 0.7 ° C / min. Then, the stator housing of the motor-wheel is subjected to finishing machining.

After finishing machining with subsequent exposure, the deviation of the diametrical dimensions of the casing from the nominal did not exceed 0.2 mm for a motor wheel with a diameter of 19 ''. For the same wheel, made without heating and cooling according to the indicated dependence, the deviations of the diametrical dimensions of the casing were 2.4 mm.

Thus, the proposed method allows to increase the accuracy of the manufacture of the stator of the motor-wheel and increase motoressurs. When welding individual parts of the body, local stresses arise and, as a result, large local deformations. The proposed heat treatment provides a redistribution of stresses throughout the welded body with a significant reduction in warpage. The parameters of this processing in the specified range provide a sufficient level of uniformity of the stress distribution over the welded unit, while not allowing the growth of structural transformations beyond the limits acceptable for the design to work.

Claims (1)

A method of manufacturing a housing with channels for the coolant of an aluminum alloy electric machine assembly, comprising assembling housing parts with a base part and their subsequent welding, characterized in that welding is performed to seal the channels of the coolant in the housing, then the housing is heated to a temperature determined by the dependence: t _n = (0.95 ÷ 1.07) _te ,
and cool it at a speed of (0.1 ÷ 4.7) ° C / min,
where t _n is the heating temperature of the housing;
t _e - the maximum operating temperature of the housing unit of an electric machine during operation.

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