RU44269U1 - STAMP FOR EXTRACTING HOLLOW PARTS - Google Patents

Abstract

The solution relates to the processing of metals by pressure and can be used for the manufacture of hollow billets such as bushings, tubes or glasses, as well as parts of an H-shaped section by cold extrusion.

It is proposed in a stamp for extruding hollow parts containing the upper and lower deforming tools in the form of a punch and a matrix with a holder and an ejector, one of which is equipped with a rotary motion drive, and the translational and rotational movement drives of the deforming tool are made in the form of two independent units with adjustable speeds for higher rotational speed on the working surface of at least one deforming tool (punch, ejector or both together) in A macro-relief was made, mainly with a roughness of the first class.

The proposed solution allows to reduce the specific load when the stamp is ~ 2 times, and therefore, to increase its resistance and at the same time not damage the surface of the parts obtained.

Description

The solution relates to the processing of metals by pressure and can be used for the manufacture of hollow billets such as bushings, tubes or glasses, as well as parts of an H-shaped section by cold extrusion.

Known stamp (RF patent No. 2082532, B 21 J 13/02, 1997), designed to extrude hollow parts, consisting of a punch, a matrix, a spring-loaded cage, placed in the matrix with the possibility of independent rotation, the ejector, rigidly connected to the matrix, having intersecting in the center of the cavity with an angle at the apex of 45-60 ° and a depth of 0.05-0.20 punch diameter. This stamp represents, in essence, a screw pair with a rigid ratio of axial velocity v to circular ω, (the punch is connected to the matrix by a screw pair), determined by the pitch of the screw S _в .

The stamp has the following disadvantages:

- the presence of a rigid screw connection between the punch and the die by means of a lead screw; at the same time, the hollow part is extruded with only one ratio of the translational and rotational speeds of the deforming tool, which limits the possibility of analyzing the influence of the ratio of speeds on the deformation process;

- depressions with a depth of 0.05-0.20 punch diameters are made on the working surface of the ejector; this leads to the fact that on the outer surface of the bottom of the glasses, squeezed out by a corrugated deforming tool, traces of corrugations remain, which must then be removed by machining, which significantly increases the complexity of manufacturing the product.

These disadvantages are partially eliminated in another well-known solution adopted as a prototype (utility model patent No. 38304 U1 B 21 J 13/02,

2004), where the installation for combined loading during metal forming is protected, containing a stamp with an upper and lower deforming tool in the form of a punch and a matrix with a holder and an ejector, one of which is equipped with a rotary motion drive, and, the translational and rotational drives of the deforming The tools are made in the form of two independent units with adjustable speeds at a higher rotational speed.

This embodiment of the drives allows to reduce the deformation force and, consequently, the specific load on the working parts of the stamp, which increases their resistance, allows you to expand the range of materials during extrusion and to obtain hollow workpieces with increased geometric parameters.

Studies have shown that the technological capabilities of the stamp can be increased.

The task at hand is the expansion of the technological capabilities of the stamp.

The technical result is a reduction in the force of deformation and the specific load on the working parts of the stamp.

This technical result is achieved by the fact that in the stamp for extruding hollow parts, containing the upper and lower deforming tools in the form of a punch and a die with a holder and ejector, one of which is equipped with a rotary motion drive, and the translational and rotational drives of the deforming tool are made in the form of two independent units with adjustable speeds at a higher rotational speed, on the working surface of at least one deforming tool (punch to, or both simultaneously ejector) macropattern is formed, preferably with a roughness

first class (Ra = 80 μm, where Ra is the arithmetic mean deviation of the profile) according to GOST 2789-73.

The proposed stamp is shown in figure 1.

The stamp includes a punch 1 mounted on the upper stationary traverse 2. A bearing 5 is mounted on the end of the cage 3 at the end of the matrix 4, a guiding punch 1. A floating cage 6 is placed in the matrix 4, the movement of which is limited from above by the bearing 5. An anti-rotation ring 7 is installed from below ejector 8. On the movable traverse (not shown in the drawing) there is a worm wheel 9 on which the matrix 4 is located. On the working surfaces of the deforming tool (at the ends 10, 11 of the punch 1 and the ejector 8 or both of them at the same time) a macro-relief was made, mainly of the first class, Ra = 80 μm.

The stamp works as follows. The blank 12 is placed in the matrix 4. When extruding the matrix 4 rotates from the worm pair and moves towards the punch 1. After the extrusion process is completed, the matrix 4 is lowered, and the ejector 8 removes the finished part from the stamp. The macrorelief on the working surface of the deforming tool creates additional adhesion in the surface layer of the workpiece 12. As a result, it becomes possible to reduce the deformation force. Moreover, the surface (bottom) of the part is not damaged.

The experiments were carried out on a setup with independent translational (υ) and rotational (ω) velocities of the punch 1 and matrix 4, respectively.

.

The effect of reducing the deformation force when squeezing the glasses according to the schemes of reverse extrusion (OV) without tool rotation and combined reverse extrusion (KOV) with rotation of the tool was evaluated by the dimensionless parameter η

where R _OV - deformation force during reverse extrusion without rotation of the tool,

R _KOV - the deformation force in the combined reverse extrusion with rotation of the tool.

Figure 2 is a graph illustrating the change in the parameter η depending on the type of macrorelief on the end surfaces of the deforming tool for various degrees of deformation and for i = const (i = 3).

The graph shows that when extruding cups from lead according to the KOV scheme: 1) the parameter η has an extremum when extruding cups with a tool with bilateral roughness of class 1 (on the punch and ejector); 2) the effect of reducing the deformation force when extruding glasses with a grooved punch is approximately the same as when extruding glasses with a smooth tool with a roughness of grade 5.

It can also be seen from the graph that when extruding glasses according to the KOV scheme from a highly plastic metal such as lead, the greatest effect in reducing the strength compared to a tool with a roughness of class 5 is found when using a tool with bilateral roughness of class 1 (on the punch and ejector). In this case, the deformation force decreases by about 2.1 times at d / h = 5 (ε = 46%), where d is the diameter of the punch, h is the height of the bottom of the glass, ε is the degree of deformation, determined by the formula (h ₀ is the initial height of the workpiece).

The proposed stamp reduces the deformation force by a factor of ~ 2 when squeezing cups with a thin bottom due to the intensification of shear deformations by performing a macro-relief on the end surfaces of the working parts of the stamp with a roughness of class 1. As a result, the specific loads on the working parts of the stamp are reduced and,

consequently, its resistance is increased. At the same time, it becomes possible to expand the range of materials for extrusion and to produce hollow billets with increased geometric parameters.

Claims (1)

A stamp for extruding hollow parts containing an upper and lower deforming tool in the form of a punch and a die with a holder and an ejector, one of which is equipped with a rotary motion drive, and the translational and rotational drives of the deforming tool are made in the form of two independent units with adjustable speeds at a higher rotational speed, characterized in that on the working surface of at least one deforming tool made macrorelief with a rough surface tew first class.