RU2509619C2 - Method of making parts - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to metal forming, particularly, to production of parts by plastic strain. Billet is clamped at mandrels of primary spindle head and tail block to deform said billet to finished part with the help of at least one spinning roller. For this, billet part is fitted on at least one first mandrel arranged to displace parallel about lengthwise axis. Mandrels are leveled so that billet top surface makes approximately inner surface shape negative to be formed at billet. Billet and spinning roller are displaced in direction parallel about lengthwise axis at pressing said spinning roller against the billet to make billet material extruded by said roller to displace the mandrel by extruded material.

EFFECT: expanded performances.

16 cl, 17 dwg

Description

The invention relates to a method for the manufacture of parts in accordance with the restrictive part of paragraph 1 of the claims.

The method in accordance with the restrictive part of claim 1 is known from DE 10 2005 057945 A1. With the corresponding methods, the workpieces that are symmetrical with respect to the rotation of the workpiece are processed primarily using pressure rollers for manufacturing, for example, support rollers, parts for automobiles or gas cylinders. In relation to the load on such products, it is desirable to increase the rigidity of individual regions already in the process of plastic deformation. When using the appropriate products, the central regions are primarily loaded, as a result of which it is preferable to strengthen the material in this region. Particularly preferred in this case is the implementation of forms with concave or conical inner surfaces, which were impossible to produce using previously known methods of rotational extrusion with thinning of the walls.

For this reason, the object of the invention is to indicate a method of the type mentioned above, by means of which parts with a concave or final inner surface can be made from a workpiece.

This problem is solved using the method with the characteristics of paragraph 1 of the claims or a machine for rotational extrusion with thinning of the walls with the signs of paragraph 10. Preferred forms of execution are given in the dependent claims.

According to the invention, in a first embodiment, the preform, preferably a cylindrical tube, is clamped on the mandrels of the main spindle head and tailstock.

The spindle head and tailstock contain respective tool bodies, each of which is concentrically around the respective mandrel and provides external centering of the workpiece. The mandrels and tool bodies each extend parallel to the axis of the machine, respectively, of the longitudinal axis of the workpiece. Each mandrel has external surfaces that taper in one direction, namely, in such a way that they form a negative concave or conical inner surface to be molded in the workpiece. Now, in accordance with the invention, one or preferably several rolls for rotational extrusion exert pressure on the outer surface of the workpiece. During processing, the sides of both mandrels facing each other are held in contact with each other. In this case, the mandrels and tool bodies are moved in such a way that the workpiece material flows first in the intermediate space between the tailstock mandrel and the corresponding tool body. Then, the tool body of the main spindle head and the corresponding mandrel are moved in such a way that the material flows substantially in the direction of the main spindle head in the region of the outer surface of the corresponding mandrel, and a part with a concave or conical inner surface is manufactured.

The invention is schematically explained below in more detail based on the drawings, which show:

figure 1 is a longitudinal section through a machine for rotational extrusion with thinning of the wall, which is made to implement the method according to the invention when clamping the workpiece and before mixing mandrels,

figure 2 - the machine of figure 1 with a clamped blank before mixing mandrels,

figure 3 - the machine of figure 1 before processing the workpiece,

figure 4 - deformation situation after plastic deformation of the part of the workpiece,

5 is a deformation situation before the completion of the plastic deformation of the workpiece,

6 is a machine for extracting the finished part,

7 is a further embodiment according to the invention in longitudinal section through a rotary extrusion machine, which is designed to implement the method according to the invention, when clamping a workpiece and before folding the mandrels,

Fig.8 - the machine of Fig.7 with a clamped blank before mixing mandrels,

Fig.9 - the machine of Fig.7 before starting the workpiece processing according to the invention,

figure 10 - deformation situation after plastic deformation of the workpiece,

11 - deformation situation at the end of the plastic deformation of the workpiece,

Fig - machine for the extraction of finished parts,

13 is a third embodiment of a rotary extrusion machine according to the invention, a longitudinal section, which is intended for the manufacture of bottles with expandable mandrel, before clamping the workpiece,

Fig.14 - the machine of Fig.13 with a clamped blank,

Fig - machine of Fig in a deformation situation after plastic deformation of one part of the workpiece,

Fig - deformation situation at the end of the plastic deformation of the workpiece,

Fig - machine when removing the finished part.

Figure 1-6 schematically shows a machine for rotational extrusion, with which you can be implemented according to the invention method.

The device shown in FIG. 1 comprises a spindle head 1 and a corresponding tool body 6 with a mandrel 4, which can be axially moved therein. The tool body 6 and the mandrel 4 are located on a common longitudinal axis MA, which passes through the center of the spindle S1 and the tailstock S2. Using the hydraulic cylinder H1, the mandrel 4 can be displaced relative to the tool body 6 in the axial direction. The mandrel 4, like the mandrel 3, have each negative shape of the inner surface of the finished part 8.2a and 8.2b. The smallest diameters are located in the plane of the facing surfaces 3c and 4c of the mandrels 3 and 4 facing each other.

The tool housing 6 opposite the spindle socket contains a bore hole 6b with a leash 6a. The bore 6b has a diameter equal to the outer diameter of the workpiece 8, whereby the billet 8 can be fastened with this bore 6b with centering relative to the longitudinal axis MA. When entering the workpiece 8, Fig. 1, the lead 6a first serves as a means of axial positioning of the workpiece 8. If the workpiece 8 is pressed by the mandrel 3 of the tailstock in the initial phase of plastic deformation, the lead 6a grips it when the spindle S1 is rotated by the tool body 6. During plastic deformation, the axial clamp of the workpiece is carried out by the axial force of deformation of the pressure rollers 7.

The tailstock 2 with the tailstock S2 of the tailstock and the tool body 5, depending on the size of the workpiece 8 subject to plastic deformation, can also be equipped with a drive synchronously rotating with the product spindle S1. The tailstock tailstock and tool body 5 are centered relative to the common longitudinal axis MA and also rotate around it.

The mandrel 3 in the tool body 5 is arranged to axially move using a hydraulic cylinder H2.

Depending on the type of rotary extrusion machine, the spindle head 1 and tailstock 2 are independently displaced to the axially positioned pressure rollers 7. As an alternative to this, there is a constructive solution in which the pressure rollers 7 are mounted with the possibility of joint movement along the axial feed and, in this case, the head 1 of the spindle is fixed, and the tailstock 2 is arranged to move. The final solution is shown in FIG. 1-6.

The mandrel 3 has a thrust surface 3d and, in the negative direction, has an external diameter of 3e, which corresponds to the inner diameter of the workpiece 8. When installing the workpiece 8, the mandrel slides into the workpiece 8 by feeding a hydraulic cylinder H2, centers the outer side of the workpiece 8 facing the mandrel 3 with an external diameter 3e, and moves it into the already described centering device 6b of the tool holder 6 in order to press it with axial pressure on the leash 6a. In this working phase, FIG. 2, the workpiece is held centering manually or with an automatic loading device until a clamp is provided.

The tool body 5, as shown in FIG. 1-6, is required only if the tailstock S2 is driven. If the tailstock quill is not actuated, the tailstock quill function is performed by mandrel 3 with a hydraulic cylinder H2. A corresponding embodiment is shown in FIG. 7-12.

After clamping the workpiece 8 (Fig. 2), the mandrel 4 moves axially in the direction of the tailstock 2 by supplying a hydraulic cylinder H1 to form a single assembly with the mandrel 3. In this case, both sides 3c and 4c of the mandrels 3 and 4 are pressed against each other, moreover, the centering nozzle 3a of the mandrel 3 is immersed in the centering hole 4a of the mandrel 4. Due to this, using both mandrels 3 and 4, a negative shape of the inner surface of the finished part is formed. The length of both components of the negative 3b, 4b corresponds in aggregate to the length of the finished part, which is molded from the workpiece 8. If between the component negatives 3b, 4b and the separating surface 3c and / or the separating surface 4c, a cylindrical shape 8c with a diameter of the separating surface 3c or 4c is provided, then the length of the finished part is increased by these values.

The same is true if, as shown in FIG. 8.2, a cylindrical mold 8c is provided in the region of the end of the workpiece from the spindle side. Alternatively, it is also possible to form an additional cylindrical shape 8c from the tailstock side.

The pressure rollers 7 move outside the clamped workpiece radially to their positions, so that they then jointly extend in the radial direction to the rotating workpiece 8, Fig.3. The combined rotation of the node from the workpiece 8, tool cases 5, 6 with mandrels 3, 4, spindle S1 and tailstock S2, is carried out using the spindle drive S1 and, depending on the version, also using the synchronously rotating tailstock drive S2.

In accordance with the invention, for plastic deformation, one or preferably several pressure rollers 7 are positioned around the perimeter of the workpiece 8. The pressure rollers 7 are arranged along the perimeter in the axial direction with a run-in bevel. Radially pressure rollers 7 are located in a position relative to the outer diameter of the finished part 8.2, which should be obtained by rotational extrusion of the workpiece 8. If the pressure rollers 7 positioned around the center of the longitudinal axis MA of the spindle S1 move together in the axial direction x due to the total feed to the rotating workpiece 8 then due to contact with the workpiece 8 they are driven into rotation. In this case, the material under the influence of axial and radial pressure of the pressure rollers 7 in the region between the pressure rollers 7 and, above all, the corresponding cross-section of the mandrel 3, changing along the axis, goes into a fluid state (figure 4). The material penetrates into the existing free space 9 between the mandrel 3 and the pressure roller 7, so that after filling the volume of free space 9, Fig. 5, move in the direction of the tailstock 2, with the installed outer diameter of the finished part 8.2 and the specified core 3 inner diameter. Due to the axial stop 3d on the mandrel 3 of the tailstock 2, this mandrel 3 is captured by the current back material while the material flows backward due to displacement. For this reason, the tolerances of the diameters of the workpiece 8 can be noticeable only along the length of the plastic-deformed part 8.2.

Since both mandrels 3, 4 are used in cooperation, they are displaced by the displaced material in the direction of the tailstock 2, while the pressure rollers 7 jointly move in the direction of the head 1 of the spindle. In this case, due to the displacement of the material from the workpiece 8, a finished part 8.2 is obtained, the outer diameter of which is reduced in comparison with the diameter of the workpiece 8, and the inner diameter is the positive of both mandrels 3, 4.

Plastic deformation is completed when the pressure rollers 7 are near the external centering 6b of the workpiece, FIG. 5. After that, the pressure rollers 7 are individually retracted to their radial starting position and together to their axial starting position. The mandrel 4 on the spindle side is disconnected and retracted, the mandrel 3 on the tailstock side is also retracted from the molded part 8.2. For this, if necessary, an external puller is provided. After removal of the tailstock 2, the molded part 8.2 is released, Fig.6.

The molded part 8.2 is characterized by a reduced outer diameter and inner diameter, which is the imprint of the contours of both mandrels 3, 4.

In the method according to the invention, the mandrels use convex, conical and cylindrical contours. Since the mandrel or the connection of two mandrels during plastic deformation, during which the material flows, is shifted due to excess material, which is formed as a result of a decrease in the cross section of the workpiece to the cross section of the finished part, the relative movement between the inner surface of the part and the mandrel does not occur.

The mandrel moves along the axis in the direction of the degree of freedom only if there is an excess of material. This means that the material which has undergone plastic deformation is rolled axially onto the mandrel and moves it further only if a sufficient amount of material is present. Thus, there is no relative movement between the mandrel and the material, but only rolling in accordance with the contour in the axial direction. This run-in of material in the region of the pressure rollers may be supported by hydraulic pressure control in the cylinders H1 and H2 or may also be difficult.

When rolling the material during plastic deformation, the so-called scuffing between the two material elements and the outer surface of the mandrel is impossible.

Tolerances in the workpiece area are selected by the extruded material without affecting the properties of the finished part, that is, the different wall thicknesses of the workpieces do not affect the wall thickness of the finished part formed by pressure rollers; material flows further only if a predetermined wall thickness of the finished part in the corresponding axial plane is reached. For this reason, only the length of the molded part is affected by tolerances. The flow rate of the material from the region of reduction of the cross section in the corresponding axial plane of the workpiece into the cross section of the corresponding plane of the finished part is formed from the excess material and the feed speed of the pressure rollers. This means that the axial speed of the node from both mandrels depends on the reduction of the cross section in one or another axial plane of the workpiece with a constant feed speed of the pressure rollers.

Thus, using this method, various steps, steps and contours can be formed in the inner surface of the body, symmetric to the relative axis of rotation, if these steps, steps and contours narrow in diameter in the direction of the separation point of the reduced mandrels.

This also applies when the work is done only with a mandrel on the side of the tailstock. Further, the method can be applied if it undergoes plastic deformation and only one part of the body is symmetrical about the axis of rotation in the longitudinal direction using one or two mandrels.

This ensures the possibility, depending on the subsequent load, of the part of the so-called beam on two supports with a constant moment of resistance.

The properties of the parts made from cylindrical billets manufactured in accordance with this method are inherent, in particular, to gas cylinders and support rollers.

7-12 show a second embodiment of a rotary extrusion machine with thinning walls according to the invention. It differs from the construction of FIGS. 1-6 only in that the tailstock side 2 ′ fulfills the function of a tailstock quill already described above, in which the tool body is not provided on the tailstock side, and only the mandrel 3 is fixed, which can be moved by axial hydraulic cylinder H2. During plastic deformation, the mandrel 3, due to the flow of material, is pushed back in the direction of the side 2 'of the tailstock against the force of the hydraulic cylinder. The rest of the method proceeds similarly to that described above with reference to figures 1-6.

An alternative embodiment is shown in Fig.13-17. Unlike the forms of execution described above, this device is only equipped with an expandable mandrel 4 'provided on the spindle side. This option is provided, in particular, for plastic deformation of cylindrical workpieces 8, in which one end is closed, for example gas cylinders.

The expanding mandrel 4 'contains approximately corresponding to the mandrel 4 of the above described embodiment, a corresponding section with a conical or conical outer surface 4b', as well as an adjacent expanding section 4d, which contains surface sections 4b '', which can be adjusted relative to the expanding mechanism 4e axis MA of the machine, so that this section approximately has the form of a mandrel 3 of the above forms of execution.

First, the workpiece 8 is pushed with its open side onto the expanding mandrel 4 ', and the pusher 10 opposite the mandrel 4' acts on the closed end of the workpiece 8 and pushes it against the stop 6a onto the tool body 6 of the spindle head 1, Fig. 14. The pusher 10 holds the workpiece 8 relative to the abutment 6a, so that the portion 4f of the mandrel 4 'can be expanded using the expanding mechanism 4e, as a result of which the above-described free space is created due to the surfaces 4b' and 4 '' between the inner wall of the workpiece 8 and the mandrel 4 ' 9, which corresponds to the negative of the shape of the inner surface to be molded. During plastic deformation using pressure rollers, the material is displaced from the workpiece 8 into the intermediate space 9, and the mandrel 4 'moves, Fig.15 and 16. After the plastic deformation process is completed, the finished form 8.2 is removed after the mandrel 4' is retracted, Fig.17, and the open end of mold 8.2 may be further processed to produce, for example, a gas bottle 8.3.

Plastic deformation using pressure rollers is carried out with the described embodiment in two directions, namely in the radial direction by reducing the outer diameter of the workpiece 8 and in the axial direction by giving a cylindrical shape with a new, reduced outer diameter. In this case, the pressure rollers 7 advance when the workpiece 8 rotates in the direction of the spindle head 1. This leads to the fact that the displacement of the material is carried out in the form of a spiral and thereby the displaced material (tangentially) is distributed both in the axial and in the circumferential direction of the mandrel 3, 4 , four'. The reason for this is the displacement of the material from a larger diameter to a smaller diameter while rotating the material.

The material flows radially to the smaller diameter of the mandrel 3, 4, 4 'and fills the hollow space tangentially due to rolling extrusion by rotation while feeding in the axial direction; and also in the axial direction, opposite to the feed movement, if there is a sufficient excess of material.

If in this situation, the mandrel 3, 4, 4 'is radially prevented from rotating, then the material should move relative to the mandrel 3, 4, 4' in the circumferential direction of the mandrel. Due to this, a relative movement of the formed body relative to the body of the workpiece arises on the fixed mandrel.

In accordance with a preferred embodiment, the mandrels 3, 4, 4 'are freely movable in the circumferential direction and in the axial direction; due to this, she can, thanks to contact with the material that has undergone plastic deformation, freely coordinate her movement with him in both of these directions. In the circumferential direction, a successful relative movement occurs in the contact-free region of the workpiece 8 relative to the mandrel 4, 4 'on the spindle side.

Reference List

1 spindle head

2 tailstock

2 'Pinol

3 Mandrel tailstock

3a axle

3b The surface of the mandrel tailstock

3c Front side mandrel mandrel

3d emphasis

3rd centering diameter of the tailstock mandrel

4, 4 'Mandrel tool spindle

4a hole

4b, 4b ', 4b' 'Tool spindle mandrel surfaces

4c End face of tool spindle mandrel

4d expansion section

4th expanding mechanism

5 Tailstock tool body

6 Product spindle tool housing

6a Capture

7 Pressure roller

8 Harvesting

8.1 Workpiece

8.1a first area

8.1b Transition area

8.1c Third area

8.2 Finished part

8.2a First area

8.2b Second area

8.2c Third area

9. Hollow space

10 Pusher

A The longitudinal axis of the workpiece, respectively, of the part

MA Longitudinal axis for the machine for rotational extrusion with thinning walls

S1 Spindle

S2 Tailstock spindle

H1 Hydraulic Cylinder Spindle Head

H2 Hydraulic Cylinder Tailstock

8.3 Gas bottle

Claims (16)

1. A method of manufacturing parts, in which a substantially cylindrical billet (8) is subjected to plastic deformation into a finished part (8.2) using at least one pressure roller (7), the following steps being performed:
a) push one section of the workpiece (8) on at least the first mandrel (3, 4 '), which is mounted with the ability to move parallel to the longitudinal axis (A) of the workpiece (8),
b) align the mandrel (3, 4 ') with the formation of the surface (3b, 4b, 4b') of the workpiece in the form of an approximate negative for the shape of the inner surface to be molded on the workpiece (8),
c) perform relative motion between the workpiece (8) and the pressure roller (7) in a direction parallel to the longitudinal axis (A) while simultaneously pressing the pressure roller (7) to the workpiece (8),
characterized in that step c) is performed in such a way that the material of the workpiece (8) is displaced under the influence of the pressure roller (7) with the mandrel (3, 4 ') moving through the extruded material. 2. The method according to claim 1, characterized in that after step a) the next section of the workpiece (8) is pushed, which is located opposite the first section, onto the second mandrel (4), mounted to move parallel to the longitudinal axis (A) of the workpiece (8) ), and then the first (3) and second (4) mandrels are brought together so that the surfaces (3b, 4b) of the workpiece (8) form a negative shape of the inner surface to be formed on the workpiece (8). 3. The method according to claim 2, characterized in that the mandrel (3, 4) in the clamping process are interconnected. 4. The method according to one of paragraphs. 1-3, characterized in that the mandrel or mandrels (3, 4, 4 ') periodically extend from the workpiece (8) in the axial direction through the flowing material and / or rotate. 5. The method according to claim 4, characterized in that the displacement occurs in the direction of the tool connected to the tailstock (2) of the first body (5), in which the first mandrel (3) is mounted with the possibility of movement. 6. The method according to one of paragraphs. 1-3, characterized in that the workpiece (8) using the leash (6a) located on the housing (6a) is pushed onto the first mandrel (3). 7. The method according to claim 6, characterized in that the workpiece (8), when pushed, is centered using the first centering device (3e) on the first mandrel (3). 8. The method according to claim 1, characterized in that at least one mandrel (3, 4) is used in the form of a cone or double cone with a conical or double conical outer surface (3b, 4b, 4b '). 9. The method according to claim 1, in which only one section of the workpiece (8) symmetric about the axis of rotation is subjected to plastic deformation. 10. Machine for rotational extrusion with thinning of the walls, in particular for the manufacture of parts by the method according to one of claims. 1-9, containing at least one mandrel (3, 4, 4 ') mounted movably parallel to the axis of the machine (MA) to push the workpiece (8) to be plastic deformed and at least one pressure roller (7) for plastic deformation blanks (8), at least one mandrel (3, 4, 4 ') is made with an outer surface having a tapering section in the region of the thrust blank (8), which forms a substantially negative shape of the inner surface to be formed on the blank (8 ), while at least at least one mandrel (3, 4, 4 ') is installed in such a way that during plastic deformation it is displaced by the material displaced by means of pressure rollers from the workpiece (8) and / or rotated. 11. A rotary extrusion machine according to claim 10, characterized in that it comprises a spindle head (1) with a tool body (6) and a corresponding mandrel (4), which is mounted with the possibility of moving parallel to the axis (MA) of the machine. 12. The rotary extrusion machine according to claim 11, characterized in that it has a tailstock (2) with a corresponding mandrel (3) mounted parallel to the axis (MA) of the machine, and both mandrels (3, 4) are located concentrically, with both mandrels (3, 4) facing each other with their end faces (3s, 4s) and each of them tapering in the direction of its end side (3s, 4s). 13. Machine for rotational extrusion according to item 12, characterized in that it provides attached to the tailstock, mounted with the possibility of rotation parallel to the axis (MA) of the machine body (5) of the tool. 14. Machine for rotational extrusion according to one of claims 11 to 13, characterized in that one mandrel (3) comprises a trunnion (3a), which, for centering with another mandrel (4), can be inserted into the hole (4a) provided on it. 15. Machine for rotational extrusion according to claim 10, characterized in that at least one mandrel (3, 4, 4 ') contains a centering element for the workpiece to be received (8). 16. Machine for rotational extrusion according to claim 10, characterized in that the mandrel (4 ') is made with an expandable device.

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