SU1741960A1 - Method and apparatus for plastic structure formation - Google Patents

Abstract

Use: processing of metals by pressure; hardening of workpieces by plastic deformation without changing the cross section. SUMMARY OF THE INVENTION: A device for plastic structure formation comprises a punch and a counterpunchon coaxially arranged in a matrix. The matrix is installed with the possibility of axial movement and rotation by 180 °. The internal cavity of the matrix is made in the form of two coaxial channels of the same cross section and length. The channels are interconnected by a section of smaller cross section. Placed in the matrix, the workpiece is plastically deformed in several cycles with preservation of its cross section. In the process of deforming the metal, the workpiece is simultaneously pressed and slump under conditions of all-round compression. This is achieved by axial displacement of the die with a fixed punch of 1 hp. f-ly. 3 il. cl

Description

The invention relates to the field of metal forming and can be used in mechanical engineering.

There is a method of metal processing by pressure, which during the draft of each billet is pushed through the deforming tool by a subsequent billet, while the rear end of the previous one and the front end of the next billet are simultaneously precipitated.

A punch die design is known, comprising a punch, a counter-punch with a smaller cross section that is coaxial with it, and an axially movable matrix with a stepped internal cavity, which covers the punch and counter-punch.

Closest to the present invention is a method of plastic structuring by treating metals with a simple shear and a structure for its implementation. The design is a matrix in which two channels intersecting at a certain angle are made, the same cross section corresponding to the section of the workpiece. To provide all-round compression, the design provides for the application of back pressure to the workpiece. The method of plastic structuring consists in repeatedly pushing the workpiece through two intersecting channels. In this case, the cross section of the workpiece does not change and plastic deformation

VI

u o o o

carried out by shifting the transverse layers of the workpiece relative to each other in the intersection area of the channels, it is again placed in the first channel and the processing cycle is repeated. An additional degree of deformation is reported in each subsequent machining cycle.

A disadvantage of the known technical solution is the low intensity and uniformity of structure formation. This is due to the low overall compression during deformation of the metal, due to the low die strength and one-sided extrusion of the blanks. The low strength of the matrix is due to the fact that the sum of the deformation pressure and the counterpressure should not exceed half the yield strength ov of the tool material, since otherwise the matrix will fail. At the same time, the pressure difference between deformation and counter pressure must exceed the deformation resistance Os of the metal to be treated to effect deformation.

The aim of the invention is to improve the quality of the workpiece through the intensification and uniformity of metal formation.

The goal is achieved by the method of plastic structure formation. including repeated deformation of the workpiece, preserving its original shape and size after each cycle of deformation, with deformation in each working cycle carried out by its extrusion, followed by simultaneous settlement of the extruded part of the workpiece. In each subsequent deformation cycle, the extrusion direction is reversed relative to the extrusion direction in the previous cycle.

The goal is also achieved by a device containing a power drive, a die made with two working channels of the same transverse size and length, a punch and a counter-punch. The matrix is made banded, movable in the axial direction and installed with the possibility of rotation together with a punch and a counter-punch through 180 °. The die channels are coaxially and communicate with one another in a smaller cross section, forming an extrusion channel. The hydraulic power drive is hydraulic in the form of a hydraulic cylinder and a hydraulic valve system for bleeding oil. The plunger cylinder is installed with the ability

alternately interacting with the punch or counter-punch, and the housing with the die.

A known extrusion operation is generally used to produce a product with a smaller cross section. The precipitation operation is known as one of the basic forging operations. The extrusion followed by a draft of the extruded end of one

0 of the same blank is an unknown technique.

The method of plastic structuring and device for its implementation is explained by the figures, where the left part

5 figures - the initial position of the right part - the end of the working cycle.

Figure 1 shows the proposed device, a General view; figure 2 - scheme of laying metal in a snap; Fig 3 - scheme

0 extraction of metal from the snap.

The device consists of a coaxially arranged punch 1 and a counter-punch 2. having the same shape and dimensions of an axially movable relative to the punches of the matrix 3, which has an internal stepped cavity consisting of two coaxial channels 4 and 5 of the same cross section. The channels communicate with a smaller cross section 6.

The device is equipped with a power cylinder, interacting with the snap. The hydraulic cylinder is installed in such a way that its plunger 7 is located above the punch 1 and the housing 8 above the die 3.

The cavity of the hydraulic cylinder 9 above the plunger 7 is filled with the working fluid and connected to the double pipelines 10 and 11 with the oil tank 12, to the pipeline 1C

0, a pressure gauge 13 and a pressure relief valve 13 are integrated. A non-return valve 15 and a pump 16 are integrated into the pipe 11. The die is placed in the guide casing 17. The hubs 18 are attached to the housing 17, which

5 are mounted in the holes of the supports 19 for rotation in them.

The device is mounted on the hydraulic press, while the contoupason 2 rests on the table of the press 20, and the supports 19 are attached to the table.

0 The housing 9 of the power cylinder mounted on the movable traverse of the press 21.

The method and operation of the device is carried out as follows.

In the initial state of the traverse of the press

5 21 with the hydraulic cylinder installed on it raised to the extreme upper position. The plunger 7 of the hydraulic cylinder is trimmed to the lowest position, the cavity 9 is filled with working fluid. Depending on the amount of compression required

a reduction valve 14 is tuned. The main part of the metal of the workpiece is in channel 5. The work cycle begins by moving the bar downwards. The plunger 7 of the hydraulic cylinder rests on the punch 1. creates a comprehensive compression of the metal of the workpiece, with further lowering of the cross member 21, the housing 8 of the hydraulic cylinder rests on the matrix 3 and moves it down in the guide body 17. At the same time, the workpiece from channel 5 flows into channel 4, reducing the cross section at the exit from channel 5 and increasing at the entrance to channel 4 with a fixed punch 1. It is at this moment that the new scheme of deformation, pressing-sediment, is realized. That is, pressing is carried out when metal passes from channel 5 to section 6, and sediment when metal passes from section 6 to channel 4. When the crosshead moves down, the working fluid is expelled from cavity 9. The pressure in this cavity is equal to the setting pressure of the pressure reducing valve 14 Bleeding is carried out via conduit 10 into the oil tank 12. When the main part of the metal enters channel 4, the traverse is stopped and lifted. Duty cycle is complete.

Next, the working fluid is pumped into the cavity 9 by the pump 16 from the tank 12 through the pipe 11 through the check valve 15, the plunger 7 of the hydraulic cylinder is lowered to the lowest position. The guide casing 17 together with the die 3, the punches 1 and 2 and the workpiece to be machined are edged around the horizontal axis of the pivots 18 by 180 °. Then, if necessary, the duty cycle is repeated. The control of the pressure of the working fluid in the cavity 9 is carried out using a pressure gauge 13.

The laying of the workpiece in the matrix 3 is carried out as follows (Fig. 2). The workpiece is placed in the channel 5 of the matrix 3. The diameter of the workpiece is slightly less than the diameter, and the length is equal to the length of the cantilever 5. The matrix is placed in the guide body 17 on the counter-punch 2. The crosshead 21 pushes down a small portion of the workpiece through the smaller stroke 6 into channel 4. Then set the punch 1 and begin to deform the workpiece.

Removing the processed workpiece from the matrix 3 is carried out after the last working cycle (Fig. 3). For this, punch 1 is removed, and instead of counter-punch 2, a punch 22 is installed having a smaller diameter than the diameter of the narrow section 6 of the matrix 3, and a length sufficient to remove the metal from the matrix 3. Then by working

the yoke 21, the workpiece is removed from the die 3.

The number of processing cycles, and therefore. and the total degree of deformation of the workpiece depends on the amount of all-round compression that the hydraulic cylinder provides. Therefore, the proposed method and device for its implementation

provides a significant increase in the ultimate plasticity of the metal, and hence an increase in the intensity and uniformity of structure formation.

PRI me R. An aluminum alloy HELL in the annealed condition was taken as the starting material. Yield point at 2.3 kg / mm2, grain size and mm. From this alloy were machined billet with a diameter of 5 mm and a length of 60 mm, laid

in tooling and deformed for nine working cycles total integrated strain indicator, 13. The integral degree of deformation in one cycle was

i 2ln- & 0.57.

i-,

where FO is the cross-sectional area of the matrix channel at do 15 mm;

F n is the cross-sectional area of a portion of a smaller matrix diameter d 13 mm. The back pressure was provided by a hydraulic cylinder tuned to a force of 15 tons. Then the metal was annealed for 1.5 minutes at 430 ° C. Grain size, after plastic

deformation and annealing was 10 mm. The yield strength was 23 kg / mm. The invention allows to obtain a qualitatively new structural state of the workpiece - microcrystalline or

amorphous, which in combination with subsequent heat treatment provides a qualitative leap in material properties.

Claims (2)

1. Method of plastic structure formation. including repeated deformation of the workpiece, preserving its original shape and size after each deformation cycle, characterized in that. in order to increase the quality of the workpieces by intensification and homogeneity of the metal structure formation, the deformation of the workpiece in each cycle is carried out by its extrusion with subsequent simultaneous draft the extruded part of the workpiece, and in each subsequent deformation cycle, the direction of extrusion is reversed relative to the direction of extrusion in the previous cycle. 2. A device for plastic structure containing a power drive, a matrix made with two working channels of the same cross section and length, a punch and a counter punch, characterized in that the matrix is made movable in the axial direction and is rotatably mounted with the punch and counter punch. on 180 °, the channels of the matrix are coaxially and communicated with one another section of smaller cross section, forming an extrusion channel, and the power drive is made hydraulic in the form of a cylinder, the plunger of which is arranged to interact alternately with a punch or counter punch, and the housing is with a matrix. .Z- -, 20 di 7 / I / / U / 1 RS, g / L nineteen g g