EP0613410A1

EP0613410A1 - Non-cutting tool for producing inner and outer profiles.

Info

Publication number: EP0613410A1
Application number: EP92923667A
Authority: EP
Inventors: Klaus Dietrich; Stefan Schmidt
Original assignee: Fraunhofer Gesellschaft zur Forderung der Angewandten Forschung eV
Current assignee: Fraunhofer Gesellschaft zur Forderung der Angewandten Forschung eV
Priority date: 1991-11-19
Filing date: 1992-11-19
Publication date: 1994-09-07
Anticipated expiration: 2012-11-19
Also published as: ATE137426T1; EP0613410B1; DE59206197D1; DE4226084A1; WO1993009896A1

Abstract

A non-cutting tool is disclosed for producing workpiece inner and outer profiles, in particular inner and outer threads. The tool has several elements (1) arranged in such a way in their initial position that they may be inserted into the workpiece. In addition, a spreading element (3) is provided that moves the tool elements (1) in a direction essentially perpendicular to the surface or in a radial direction into an engagement position, in which the tool elements (1) are pressed on the workpiece (6) in such a way that no gaps are left between them and the desired profile is formed.

Description

Tool for non-cutting production of external or

Inner contours

Description

Technical field

The invention relates to a tool for the chipless production of external or internal contours on workpieces and in particular of external or internal threads.

State of the art

External or internal threads are currently essentially rolled, pressed, cut or cast.

The thread rolling is mainly suitable for solid workpieces, whereby it results in a high work hardening and an uninterrupted fiber flow with a short processing time.

Threading is essentially suitable for thin-walled, rotationally symmetrical parts, preferably made of aluminum. With two profiled rollers, one of which is arranged in a fixed position and the other is adjustable, the thread is created by pushing the thin-walled part between the rollers. However, the part must rotate.

Thread cutting is only suitable if the material thickness is sufficient and produces an interrupted fiber course with a long machining time. Ultimately, casting a thread is very complex; nevertheless there is often insufficient accuracy with a very long processing time.

From DE 32 00 755 AI a tool for the non-cutting production of internal threads is known, which is assumed in the formation of the preamble of claim 2. This known tool has two segments which are arranged in a basic state such that they can be inserted into the tubular workpiece. A spreading element transfers the segments by a movement in the radial direction into an engagement state in which the segments are pressed against the tubular component in such a way that they (partially) form the thread.

However, this known generic tool has the disadvantage that it cannot be used to easily produce technically usable internal threads:

In particular, this tool does not provide a complete thread if it is not rotated and moved during use, as there are gaps between the segments. This means that no screw can be screwed into the internal thread produced with this tool without additional machining processes.

It is consequently stated in DE 32 00 755 AI that the tool is rotated by approximately 90 ° to impress a complete thread and is additionally shifted linearly by a quarter pitch. However, this not only increases the manufacturing effort, but can also lead to manufacturing errors. In addition, the wear on the tool is increased. It is for this reason that the tool known from DE 32 00 755 AI has no further significance

Presentation of the invention

The invention is based on the object of specifying a tool for the non-cutting production of external or internal contours on workpieces and in particular of external or internal threads, which, for a short machining time, can produce, for example, "self-contained", i.e. All-round contours and especially threads with high accuracy and surface quality allowed without the tool would wear out quickly. Furthermore, the tool according to the invention should, if appropriate, make it possible to carry out cutting or separating processes.

This object is achieved according to the invention for the production of outer contours by the features of claims 1 and 12 and for the production of inner contours by the features of claims 2 and 13. Further developments of the invention are the subject of the dependent claims.

The tool according to the invention for the non-cutting production of external contours on workpieces and in particular of external threads has several tool elements which are arranged in a basic state in such a way that the workpiece can be inserted into them. A spreading element transfers the tool elements into a state of engagement essentially in a radial direction, in which the tool elements are pressed onto the workpiece in such a way that they adjoin one another without space and form the desired contour. Accordingly, the tool according to the invention for the non-cutting production of internal contours on recesses in workpieces and in particular internal threads has a plurality of tool elements which are arranged in a basic state in such a way that they can be inserted into the recess of the workpiece or into a tubular workpiece. A spreading element transfers the tool elements into a state of engagement by movement substantially perpendicular to the surface of the workpiece or in the radial direction, in which the tool elements are pressed onto the tubular workpiece in such a way that they form the desired contour.

According to the invention, at least three tool elements are provided, which are arranged in the engaged state in such a way that they connect to one another without a gap.

Here, of course, the tool elements are provided on their engagement surface with a contour that is complementary to the desired inner contour.

The contour of the respective engagement surfaces does not necessarily have to be designed such that a thread is produced. Rather, the tool elements can be provided with a different (even non-uniform) shape instead of a thread, so that any internal or external contours can be created. If required, these contours can result in a closed circle (360 °).

Of course, it is also possible, according to claim 9, for the individual tool elements to be provided with different contours on their engagement surface. This makes it possible, for example, to To bring in threads only over part of the circumference and to push back the material of the workpiece in the part of the circumference into which no thread is to be introduced, "behind the threaded base".

In any case, very thin-walled, cold-formable materials can be processed without separating the fiber course and a large work hardening, in addition there is the possibility to incorporate sealing surfaces or to calibrate sealing surfaces that have already been created or to protect them from possible damage. The elements can also perform not only a linear movement, but also a movement composed of several linear movements. The tool according to the invention does not require any rotating tool elements or counterholders, i.e. simple requirements are imposed on the drives.

In this way, threads can be produced with simple tools using a tool designed according to the invention, the tool life being long.

In the following claims 12 implementations of the basic idea according to the invention are described which enable the cutting of tubular workpieces or workpieces with any cross-section from the inside to the outside without reshaping the tube. In addition, these realizations enable the non-cutting production of outer or inner contours on workpieces which have freely selectable cross-sections, that is to say, for example, as rectangular profiles, or oval, or as contours composed of individual curve parts . Ultimately, in addition to forming work, it is also possible to completely or partially cut or cut workpieces or to make openings in the wall of the workpiece.

The tool according to the invention for the non-cutting production of external contours on workpieces with a free cross-section or for carrying out cutting work from the outside inwards has a plurality of tool elements which are arranged in the basic state such that the workpiece can be inserted into the tool. By means of a movement perpendicular to the surface of the workpiece, an expanding element converts the tool elements into an engagement state in which the tool elements are pressed onto the workpiece in such a way that they form the desired contour or carry out cutting, notching or perforating work.

Accordingly, the tool according to the invention for the non-cutting production of internal contours on workpiece recesses with a free cross-section or for carrying out cutting work of such workpieces from the inside to the outside has a plurality of tool elements which are arranged in the basic state such that they are recessed of the workpiece are insertable. A spreader element brings the tool elements into a state of engagement by movement substantially perpendicular to the surface of the workpiece, in which the workpiece elements are pressed against the workpiece walls in such a way that they form the desired contour or perform cutting, notching or perforating work.

According to the invention, the tool elements are arranged in the engaged state so that they are at least for Connect the complete cutting or shearing process (segmentation) of the workpiece to one another without any space.

The number of tool elements is predetermined by the respective cross section of the workpiece. For triangular and rectangular profiles of the workpiece, the number of sides or corners of the polygon corresponds to the number of required leading and trailing tool elements. For example, if the workpiece has a rectangular profile, four leading and four lagging tool elements are required.

The complete separation on the circumference of the workpiece (segmentation) or the creation of openings, perforations, notches, etc. can also be done with non-metallic materials, e.g. Cardboard tubes, plastic parts or profiles, etc. carry out.

Brief description of the drawing

The invention is described below by way of example without limitation of the general inventive concept by means of exemplary embodiments with reference to the drawing, to which reference is expressly made with regard to the disclosure of all details according to the invention not explained in detail in the text. Show it:

Fig. La shows a longitudinal section, and

1b and 1c a cross section through a first exemplary embodiment,

2a to 2c corresponding representations for a variant of the first embodiment, 3a to 3d corresponding representation for a further variant of the first embodiment,

4 shows a cross section through a second exemplary embodiment,

5a shows a longitudinal section, and

5b and 5c a cross section through a third exemplary embodiment,

Fig. 6 shows a tool with the additional possibility of producing sealing surfaces, and

7a shows a longitudinal section, and

7b and 7c a cross section through an arrangement for cutting or shearing off rectangular hollow profiles.

Representation of exemplary embodiments

The invention is described below using tools for producing internal threads. The basic ideas according to the invention can accordingly also be transferred to tools for producing external threads.

Furthermore, the same or corresponding parts with the following reference numerals are in the following figures:

1 tool element (s)

1.1 leading tool element

1.2 lagging tool element

2 guide plate n)

2.1 wedge-shaped auxiliary elements

3 wedge / cone 4 feedback element

5 counterholders (divisible)

6 workpiece to be machined

7 Element for forming / maintaining a sealing lip

referred to, so that there is no renewed presentation, and only the deviations of the exemplary embodiments shown in these figures from the first exemplary embodiment are explained:

1 shows a first exemplary embodiment of the invention, which has four leading tool elements (main elements) 1.1 with a thread structure on the outer surface and four (secondary elements) 1.2, which are also provided with a thread structure. The tool elements 1.1 and 1.2 each have the shape of circular segments. The main elements 1.1 are guided by a cover and base plate 2 with pins and elongated holes in the main elements or by other suitable guide systems. The secondary elements 1.2 are connected by interlocking guides with the main elements 1.3 and an outer cone 3, so that a forced return occurs. Furthermore, a divisible outer ring 5 with or without a threaded structure and a cruciform extension cone 3 with or without interlocking guides for the secondary elements 1.2 are provided.

The functionality of this tool is explained below:

First, the outer ring 5 is placed on a preformed cylindrical section of a workpiece 6. (Fig. Lb), by pushing in the extension cone 3, the main elements 1.1 are pushed out by the secondary elements 1.2 and produce the thread (FIG. 1c). By returning the cone 3, the elements 1.1 and 1.2 are reset (Fig. Lb). Finally, the tool is extended and the outer ring 5 is removed.

A completely circumferential thread can thus be created by appropriately designing the main and secondary elements. The elements are designed so that, starting from an initial position (diameter smaller than the thread core diameter), they reach an end position in which they produce a complete thread, i.e. an end position in which there are no gaps between the individual segments when extended.

2a to 2c show FIG. 1 corresponding representations for a variant of the first embodiment which differs from the example shown in FIG. 1 in that instead of four tool elements (main elements) 1.1 with a gain ¬ destructive structure on the outer surface and four trailing tool elements (secondary elements) 1.2 three elements are present. Accordingly, a hexagonal extension cone 3 is provided.

The further training and the mode of operation correspond to the first embodiment.

3a shows a longitudinal section through a further variant of the first exemplary embodiment; 3a to 3d show corresponding cross sections, with FIG. 3d a modification of the in FIGS. 3b and 3c shows training. In this embodiment, three main and secondary elements 1.1 and 1.2 are moved linearly outward from a basic state and produce a completely circumferential thread (FIG. 3c). An "intermediate step" is shown in Fig. 3b. With regard to further details, reference is made to the drawing.

4 shows a second exemplary embodiment in which two main elements 1.1 designed as circular sections are rotatably supported on one side and are moved outwards on circular paths by a secondary element 1.2. The process can also be viewed as a spreading process between two "jaws".

5 shows a third exemplary embodiment, in which a thread contour is provided only on every second segment. The segments without a thread contour are "advanced" over the outer contour of the segments with a thread contour, so that the material of the workpiece is pushed back "behind the thread base" in the part of the circumference into which no thread is to be introduced (FIG. 5c).

FIG. 6 shows an exemplary embodiment in which a sealing surface can be produced by a corresponding design of the tool elements in the area of the thread. A sealing surface is to be provided if a closure means with a sealing function is to be introduced into the thread to be produced. This sealing surface can be produced both in the case of external and internal threads by the tool elements and / or additional shape-supporting or shape-producing auxiliary elements 7. If undercuts are created when creating the sealing surface, separable counterholders 5 must be used.

Instead of extending the tool elements by means of a cone-shaped mandrel which is moved perpendicular to the extending movement of the tool elements, as is used in the exemplary embodiment described, other extending mechanisms can of course also be used:

Extension cam

Here, an eccentrically mounted circular disc or a cam disc is rotated and thus leads the tool elements to the outside. The cam can also be designed in a special curve shape in order to enable targeted shaping or the application of force.

Lever mechanism

The tool elements can also be extended by a lever mechanism, e.g. Articulated lever principle. This results in a forced return.

Exit wedge

The tool elements are e.g. radial

Movement of a wedge extended.

In the exemplary embodiments described above, external guidance of the tool elements has been used as the guide system. Here, the tool elements are guided through a plate arranged below or above, or plates 2 arranged on both sides with integrated linear guide elements. Rails of various shapes as well as ball or pin guides can be used as guide elements. An internal tool guide can of course also be used. Here linear guide elements are integrated into the tool elements. The guide elements can be designed as plates with guide rails in various shapes or as pin guides.

Radial or axial bearings can also be used. Such bearings are used in particular in lever systems and replace the linear guide elements.

Spring resets 4 can in particular be used as the resetting mechanism for tool elements. Feathers in various forms, e.g.

- leaf spring

- tension spring

- Compression springs, which act on each element individually, are used. The second possibility of spring return can be designed as an elastic band (e.g. spiral spring), which acts on all the tool elements involved at the same time.

The forced return can be generated by a lever mechanism, which causes the tool elements to be extended and retracted. Another possibility of the forced reset can be done by interlocking guide systems both in the tool elements and in an extension cone or wedge. As a result, the tool elements are forcibly retracted when the extension cone is returned. FIG. 7 shows an exemplary embodiment of a tool for carrying out complete separation processes (segmentation) from the inside to the outside.

The tool is inserted into the hollow profile.

The leading tool elements 1.1 (main elements) virtually span the four corners of the workpiece with a rectangular hollow profile. The trailing tool elements 1.2 (secondary elements) close the cutting edge of the cutting tool along the circumference of the rectangular profile of the recess in the extended state.

The tool elements 1.2 are retracted and extended by means of a cross-shaped extension cone 3 as a spreading element.

The tool elements 1.1 are guided through a cover and base plate 2 with pins and elongated holes in the tool elements or through other suitable guide systems. The secondary elements 1.2 are connected by interlocking guides with the main elements and the outer cone 3, so that a positive advance or return occurs.

Claims

Patent claims

1. Tool for the non-cutting production of external contours on workpieces and in particular of external threads, with a plurality of tool elements which are arranged in a basic state such that the workpiece can be inserted into them, and an expansion element which moves the tool elements by a movement in the transferred substantially perpendicular to the surface or in the radial direction into an engagement state in which the tool elements are pressed onto the workpiece in such a way that they adjoin one another without a space to form the desired contour.

2. Tool for the non-cutting production of internal contours on recesses in workpieces and in particular internal threads, with several tool elements (1) which are arranged in a basic state such that they can be inserted into the workpiece (6), and a spreading element (3), which transfers the tool elements by a movement substantially perpendicular to the surface of the workpiece or in the radial direction into an engagement state, in which the tool elements are pressed onto the workpiece in such a way that they form the desired contour, characterized that at least three tool elements are provided which are arranged in the engaged state in such a way that they connect to one another without a gap.

3. Tool according to claim 2, characterized in that the tool at least has two leading tool elements (1.1) and two trailing tool elements (1.2), which are arranged in the basic state within the outer contour of the leading tool elements.

4. Tool according to one of claims 1 to 3, characterized in that the expansion element has an extension mechanism and a guide for the tool elements.

5. Tool according to claim 4, characterized in that the extension mechanism is an extension cam, a lever mechanism or an Ausfahr¬ wedge or cone.

6. Tool according to claim 4 or 5, characterized in that the guide is an outer or inner guide which enables a linear movement or a movement composed of a plurality of linear movements.

7. Tool according to claim 4 or 5, characterized in that the guide has radial or axial bearings.

8. Tool according to one of claims 1 to 7, characterized in that the expansion element has a reset mechanism.

9. Tool according to one of claims 1 to 8, characterized in that the tool elements are provided on their engagement surface with different contours.

10. Tool according to one of claims 1 to 9, characterized in that the tool with tool elements in engagement can also be used as a workpiece holder for further machining operations.

11. Tool according to one of claims 2 to 10, characterized in that during processing thin-walled workpiece parts (6), a counter element (5) is inserted.

12. Tool for the non-cutting production of outer contours and for cutting workpieces with several tool elements, which are arranged in a basic state in such a way that the workpiece can be inserted into them, and a spreading element (3) which holds the tool elements (1). transferred by a movement substantially perpendicular to the surface into an engagement state in which the tool elements are pressed onto the workpiece free cross-section such that they form the desired contour and / or cutting, notching or perforating work from the outside perform inside.

13. Tool for the non-cutting production of inner contours on workpiece recesses with a free cross-section and for cutting workpieces with several tool elements (1), which are arranged in a basic state in such a way that they can be inserted into the workpiece, and an expansion element (3) which brings the tool elements into a state of engagement by movement substantially perpendicular to the surface of the workpiece, in which the tool elements are pressed against the workpiece walls in such a way that they form the desired contour, characterized in that the tool elements (1) are arranged in the engaged state in such a way that they connect to one another without space at least for the complete cutting or shearing process of the workpiece.

14. Tool according to claim 13, characterized in that the number of Werkzeugele¬ elements (1) of the respective polygonal cross-section is vorgee¬, wherein for triangular and rectangular profiles of the workpiece, the side or corner number of the polygon of the respective number of leading Tool elements (1.1) and trailing tool elements (1.2) correspond.

15. Tool according to one of claims 12 to 14, characterized in that it can be used for cutting, for the manufacture of openings, perforations, notches, etc., even in the case of non-metallic materials, such as cardboard tubes and plastic profiles.

16. Tool according to claim 13, characterized in that it is applicable for the joining process of specially shaped tube-hub connections, e.g. by notching tabs, drivers or the like, which engage in the hub and thus produce positive locking.

17. Tool according to claim 13, characterized in that it generates the desired inner contour both by the tool elements and by the axially retracting expansion element designed in accordance with the inner contour.

18. Tool according to claim 13, characterized in that the tool segments are extended by cams by means of a rotary movement.

19. Tool according to claim 13, characterized in that it is suitable as a tool combination for widening and subsequent extension of additional tool segments.