DE102022113360B4 - MULTIPLE COLD EXTRUSION REINFORCEMENT DEVICE AND METHOD OF USE THEREOF - Google Patents

Abstract

The invention belongs to the technical field of mechanical processing equipment and relates to a multi-piece cold extrusion reinforcement device comprising a first extrusion mandrel and a plurality of second extrusion mandrels coaxially and detachably connected by a first sleeve, and the diameter of the latter second extrusion mandrel is larger than that of the first second extrusion mandrel, and the first extrusion mandrel is detachably connected by a second sleeve to the second extrusion mandrel having the smallest diameter. The extrusion device of the present invention, manufactured by combining multiple pieces of mandrels of different sizes, can complete continuous multi-piece hole extrusion reinforcement in a single positioning state with a smaller single extrusion volume, effectively reducing processing damage; and the roundness of the processed hole is ensured by the multi-piece extrusion process, effectively improving the shape of the hole perimeter; in the reinforcement type of two-time mandrel cold extrusion reinforcement, the single extrusion volume is smaller, and no additional bushing process is required, saving the time required for processing, improving processing efficiency, and further increasing the reinforcement effect, which is practical and worthy of promotion.

Description

technical field

The invention belongs to the technical field of mechanical processing equipment and relates in particular to a multi-part cold extrusion reinforcing device according to the preamble of claim 1 and its method of use according to the preamble of claim 7

State of the art

TB6 titanium alloy is a β-type titanium alloy with high strength and low density, good mechanical properties, toughness and corrosion resistance, good compatibility with composite materials, etc. It is widely used in the production and manufacture of advanced aircraft structures, but its processing is difficult and requires a high level of technology and process accuracy. Hole system structures are widely used in aircraft structures due to the need for mechanical connections. In the course of use, there will be more stress concentration at the edge of the hole and micro-movement wear between the bushings and sleeves and other ancillary structures and the hole wall, resulting in a high risk of contact fatigue damage to the titanium alloy connecting hole structure.

Previous research has shown that the surface microstructure of the material is one of the most important factors affecting the fatigue life of a structure, while factors such as the corrosive capacity of the environment and the shape and size of the structure can also affect the fatigue life of the structure. Therefore, the fatigue life of the hole is improved mainly from two points of view: first, the design of the structure is optimized to ensure the working environment; on the other hand, the hole perimeter is increased to improve the local fatigue life. In actual production and application, anti-fatigue manufacturing techniques such as surface blasting, laser impact technique, rolling and cold extrusion technique are mainly used to improve the fatigue strength of the structure. However, due to the small diameter of the parts used in the aircraft and the large number of open holes, it is not suitable to use methods such as rolling and surface blasting, while cold extrusion reinforcement is less restricted by the conditions.

The current cold extrusion reinforcement of open-hole aircraft parts mainly uses a one-time cold extrusion process, usually using the interference assembly method or mandrel extrusion method. The interference assembly is to use the elastic deformation of the material around the hole to expand and deform the hole and put it on the connecting parts such as screws and rivets when the hole is recovered to release the hoop force on the connecting parts generate so that the two parts are connected together, this method can generate tensile stress around the hole to reduce the magnitude of the loading stress. Mandrel extrusion consists of using a lubricated extrusion mandrel to force through the initial hole in the form of an interference under the action of an external load; after passing the extrusion mandrel, the plastic deformation layer is extruded through the outer elastic zone, to form an elastic-plastic deformation zone on the hole wall with a favorable compressive residual stress distribution, when the open-hole component is subjected to cyclic external load, the compressive residual stress can exceed the tensile stress reduce so that the average stress is reduced, effectively reducing the propagation of fatigue microcracks, and effectively improving the fatigue life of the structure. At the same time, to reduce wear on the hole wall, an additional bushing (or sleeve) method can be used to isolate direct contact between the mandrel and the hole wall; the difference between the bushing and sleeve is that the bushing is removed after extrusion while the sleeve remains in the hole to ensure high compression assembly. And the additional bushing (or sleeve) method also has the problems of complex process, possible post reaming and micro-motion wear.

In view of these, in the design and manufacture, the two-time cold extrusion reinforcement process is generally adopted to avoid the process problems that exist in the one-time cold extrusion reinforcement; Generally, before the press-fit bushing hole extrusion, a mandrel extrusion is performed so that a higher magnitude residual compressive stress field can be formed on the open-hole component first, and then the press-fit bushing hole extrusion is performed. Compared with one-time cold extrusion reinforcement, twice the amount of extrusion is smaller, but the overall effect is better, and the subsequent rubbing process is not required. Although the two-time cold extrusion reinforcement has great advantages in enhancing the reinforcement effect and ensuring the hole wall structure, its Ver working technology relatively complex. In addition to the two cold extrusion processes, a bush assembly process with high precision requirements must be added. The single extrusion amount of two-time cold extrusion reinforcement is still large, and the damage to the surface of the hole wall cannot be ignored, and the fretting between the bushing and the hole wall cannot be avoided.

• (1) für die Art der Verstärkung mit einer einmaligen direkten Extrusion des Dornes hat der Kaltextrusion-Verstärkung-Prozess eine große Extrusionsmenge mit einer einmaligen direkten Extrusion des Dornes, die große axiale Schäden an der Oberfläche der Lochwand verursachen können;
• (2) für die Art der Verstärkung mit einer einmaligen direkten Extrusion des Dornes mit zusätzlichen Schlitzbuchsen, wird im Prozess der Kaltextrusion-Verstärkung die geschlitzte Buchse für eine einmalige Kaltextrusion verwendet, und die Komponente mit offenem Loch muss anschließend aufgerieben werden, um die Rundheit des Lochs sicherzustellen, aber das Aufreiben verursacht eine Beschädigung der elastisch-plastischen Verformungszone, die durch die Kaltextrusion erzeugt wird, wodurch die Ermüdungsbeständigkeit der Komponente mit offenem Loch beeinträchtigen wird;
• (3) für die Art der Verstärkung mit einer zweimaligen direkten Extrusion des Dornes ist die Einzelextrusionsmenge der zweimaligen Kaltextrusion-Verstärkung im Prozess der Kaltextrusion-Verstärkung immer noch groß, und die axiale Beschädigung der Oberfläche der Lochwand kann nicht ignoriert werden, und die Verarbeitungstechnologie der zusätzlichen Buchse ist komplizierter und dauert eine lange Zeit, und die Verarbeitungseffizienz ist gering, und es gibt auch das Problem des Reibverschleißes zwischen der Buchse (oder Hülse) und der Lochwand . Die Aufgabe der Erfindung ist es die genannten Probleme zu beseitigen.

In cold extrusion reinforcement of TB6 titanium alloy open hole components, the main disadvantages of some existing process methods are as follows:

• (1) for the type of reinforcement with a one-time direct extrusion of the mandrel, the cold extrusion reinforcement process has a large amount of extrusion with a one-time direct extrusion of the mandrel, which can cause large axial damage to the surface of the hole wall;
• (2) for the type of reinforcement with a one-time direct extrusion of the mandrel with additional slotted bushings, in the process of cold extrusion reinforcement, the slotted bushing is used for one-time cold extrusion, and the open-hole component must then be reamed to improve the roundness of the Holes to ensure, but the reaming causes damage to the elastic-plastic deformation zone generated by the cold extrusion, which will affect the fatigue resistance of the open hole component;
• (3) for the type of reinforcement with a two-time direct extrusion of the mandrel, the single extrusion amount of two-time cold extrusion reinforcement in the process of cold extrusion reinforcement is still large, and the axial damage to the surface of the hole wall cannot be ignored, and the processing technology of the additional bush is more complicated and takes a long time, and the processing efficiency is low, and there is also the problem of fretting between the bush (or sleeve) and the hole wall. The object of the invention is to eliminate the problems mentioned.

content of the invention

In view of this, the present invention provides a multi-piece cold extrusion reinforcing device having the features of claim 1 and its method for use with the features of claim 7 to solve the technical problems mentioned above.

• eine mehrteilige Kaltextrusion-Verstärkungsvorrichtung, umfassend:
  • einen ersten Extrusionsdorn;
  • eine Vielzahl von zweiten Extrusionsdornen, die koaxial und lösbar durch eine erste Hülse verbunden sind, und der Durchmesser des letzteren zweiten Extrusionsdorns ist größer als der des ersteren zweiten Extrusionsdorns, und der erste Extrusionsdorn ist lösbar durch eine zweite Hülse mit dem zweiten Extrusionsdorn mit dem kleinsten Durchmesser verbunden.

The technical solution of the present invention is:

• a multi-piece cold extrusion reinforcement device comprising:
  • a first extrusion mandrel;
  • a plurality of second extrusion mandrels coaxially and detachably connected by a first sleeve, and the diameter of the latter second extrusion mandrel is larger than that of the former second extrusion mandrel, and the first extrusion mandrel is detachable by a second sleeve with the second extrusion mandrel having the smallest diameter connected.

• einen ersten Zylinder, einen ersten Kegelstumpf, einen zweiten Zylinder und eine erste Verbindungsstange, die nacheinander fest verbunden und koaxial angeordnet sind, wobei die erste Verbindungsstange ein an ihrem Umfang geöffnetes erstes Außengewinde aufweist, der zweite Zylinder einen größeren Durchmesser als der Durchmesser des ersten Zylinders hat, der erste Zylinder einen größeren Durchmesser als der Durchmesser der ersten Verbindungsstange hat.

Preferably, the first extrusion mandrel comprises:

• a first cylinder, a first truncated cone, a second cylinder and a first connecting rod, fixed in succession and arranged coaxially, the first connecting rod having a first external thread open at its periphery, the second cylinder having a larger diameter than the diameter of the first cylinder has, the first cylinder has a larger diameter than the diameter of the first connecting rod.

Preferably, the end face of the first cylinder remote from the first truncated cone, the junction between the first cylinder and the first truncated cone, and the junction between the first truncated cone and the second cylinder are all provided with rounded corners.

• eine zweite Verbindungsstange, einen dritten Zylinder, einen zweiten Kegelstumpf, einen vierten Zylinder und eine dritte Verbindungsstange, die nacheinander fest verbunden und koaxial angeordnet sind, wobei die dritte Verbindungsstange, die zweite Verbindungsstange und die erste Verbindungsstange den gleichen Durchmesser aufweisen, die zweite Verbindungsstange und die dritte Verbindungsstange an ihrem Umfang ein zweites Außengewinde aufweisen, das die gleichen Strukturparameter wie das erste Außengewinde hat, der vierte Zylinder einen größeren Durchmesser als der Durchmesser des dritten Zylinders hat, der dritte Zylinder einen größeren Durchmesser als der Durchmesser der dritten Verbindungsstange hat.

Preferably, the second extrusion mandrel comprises:

• a second connecting rod, a third cylinder, a second truncated cone, a fourth cylinder and a third connecting rod, fixed in succession and arranged coaxially, the third connecting rod, the second connecting rod and the first connecting rod having the same diameter, the second connecting rod and the third connecting rod has a second external thread on its periphery having the same structural parameters as the first external thread, the fourth cylinder has a larger diameter than the third cylinder diameter, the third cylinder has a larger diameter than the third connecting rod diameter.

Preferably, the end surface of the third cylinder facing away from the second truncated cone, the connection between the third cylinder and the second truncated cone and the connection between the second truncated cone and the fourth cylinder are all provided with rounded corners.

Preferably, the first sleeve and the second sleeve have the same structure and both comprise a cylindrical tube, the inner wall of the cylindrical tube being opened with an internal thread that mates with the second external thread.

• Auswählen eines geeigneten ersten Extrusionsdorns, einer Vielzahl von zweiten Extrusionsdornen, einer ersten Hülse und einer zweiten Hülse; Verbinden einer Vielzahl von zweiten Extrusionsdornen durch die erste Hülse zu zweit koaxial entfernbar, wobei der Durchmesser des letzteren zweiten Extrusionsdorns größer als der des ersteren zweiten Extrusionsdorns ist; und Verbinden des ersten Extrusionsdorns durch die zweite Hülse mit dem zweiten Extrusionsdorn mit dem kleinsten Durchmesser in einer axialen Reihe, wodurch eine mehrteilige Kaltextrusion-Verstärkungsvorrichtung gebildet wird;
• Einspannen des zweiten Extrusionsdorns mit dem größten Durchmesser in die Antriebsvorrichtung, so dass die mehrteilige Kaltextrusion-Verstärkungsvorrichtung vertikal eingestellt ist;
• Befestigung der zu bearbeitenden Komponente mit offenem Loch an der Stützfläche, wobei das Loch nicht verdeckt wird und genügend Raum für den Durchgang der mehrteiligen Kaltextrusion-Verstärkungsvorrichtung bleibt;
• Verwenden des Schmiermittels, um die zu bearbeitende Oberfläche der zu bearbeitenden Komponente mit offenem Loch und die Oberfläche der mehrteiligen Kaltextrusion-Verstärkungsvorrichtung zu schmieren;
• Einsetzen des unteren Endes des ersten Extrusionsdorns in das zu bearbeitende Loch, Aktivieren der Antriebsvorrichtung und Schieben des ersten Extrusionsdorns durch das zu bearbeitende Loch, um die erste Kaltextrusion-Verstärkung der zu bearbeitenden Fläche der zu bearbeitenden Komponente mit offenem Loch durchzuführen, und weiteres Schieben der zweiten Extrusionsdorne durch das zu bearbeitende Loch Teil für Teil, um die mehrteilige Kaltextrusion-Verstärkung der zu bearbeitenden Fläche durchzuführen;
• Zurücksetzen in der entgegengesetzten Richtung und Zurückziehen der mehrteiligen Kaltextrusion-Verstärkungsvorrichtung nachdem die mehrteilige Kaltextrusion-Verstärkung abgeschlossen ist.

Method of using the multi-piece cold extrusion reinforcement device includes the following steps:

• selecting an appropriate first extrusion mandrel, a plurality of second extrusion mandrels, a first sleeve and a second sleeve; connecting a plurality of second extrusion mandrels through said first sleeve in twos removably coaxial, the latter second extrusion mandrel having a diameter greater than that of the former second extrusion mandrel; and connecting the first extrusion mandrel through the second sleeve to the second extrusion mandrel having the smallest diameter in an axial series, thereby forming a multi-piece cold extrusion reinforcement device;
• clamping the second largest diameter extrusion mandrel into the drive assembly so that the multi-piece cold extrusion augmentation assembly is vertically adjusted;
• attaching the component to be machined with an open hole to the support surface, leaving the hole unobscured and leaving sufficient space for the multi-piece cold extrusion reinforcement device to pass therethrough;
• using the lubricant to lubricate the machined surface of the machined open hole component and the surface of the multi-piece cold extrusion reinforcing device;
• Inserting the lower end of the first extrusion mandrel into the hole to be machined, activating the driving device and pushing the first extrusion mandrel through the hole to be machined to perform the first cold extrusion reinforcement of the machined face of the open-hole component to be machined, and further pushing the second extrusion mandrels through the hole to be machined piece by piece to perform the multi-piece cold extrusion reinforcement of the surface to be machined;
• resetting in the opposite direction and retracting the cold extrusion multi-piece reinforcement device after the cold extrusion multi-piece reinforcement is complete.

Compared with the prior art, the present invention provides a multi-piece cold-extrusion reinforcement device and its method of use, which achieve the goal of multi-piece hole cold-extrusion reinforcement under the premise of less damage to the hole wall of the open-hole component, thus extending its fatigue life can. In addition, the extrusion device of the present invention, which is made by combining multiple parts of mandrels of different sizes, can have a continuous multi-part compared to the type of reinforcement with a one-time direct extrusion of the mandrel and the type of reinforcement with a one-time direct extrusion of the mandrel with additional slotted bushings -Complete hole extrusion reinforcement in a single positioning state, with a smaller single extrusion volume, effectively reducing processing damage; and the roundness of the processed hole is ensured by the multi-piece extrusion process, effectively improving the shape of the hole perimeter; in the reinforcement type of two-time mandrel cold extrusion reinforcement, the single extrusion volume is smaller, and no additional bushing process is required, saving the time required for processing, improving processing efficiency, and further increasing the reinforcement effect, which is practical and worthy of promotion.

character list

• 1 Fig. 12 is a schematic representation of the overall structure of Embodiment 1 of the present invention (using three parts as an example);
• 2 Fig. 12 is a schematic representation of the structure of the first extrusion mandrel of Embodiment 1 of the present invention;
• 3 Fig. 12 is a schematic representation of the structure of the second extrusion mandrel of Embodiment 1 of the present invention;
• 4 Fig. 12 is a schematic representation of the cross-sectional structure of the first sleeve of Embodiment 1 of the present invention.

1

erster Extrusionsdorn;

2

zweite Hülse;

3

zweiter Extrusionsdorn;

4

erste Hülse;

5

dritter Extrusionsdorn;

6

Endfläche des ersten Zylinders;

7

erster Zylinder;

8

erster Kegelstumpf;

9

zweiter Zylinder;

10

erste Verbindungsstange;

11

zweite Verbindungsstange;

12

dritter Zylinder;

13

zweiter Kegelstumpf;

14

vierter Zylinder;

15

dritte Verbindungsstange;

16

zylinderförmiges Rohr; 17, Innengewinde.

As shown in the figures:

1

first extrusion mandrel;

2

second sleeve;

3

second extrusion mandrel;

4

first sleeve;

5

third extrusion mandrel;

6

end face of the first cylinder;

7

first cylinder;

8th

first truncated cone;

9

second cylinder;

10

first connecting rod;

11

second connecting rod;

12

third cylinder;

13

second truncated cone;

14

fourth cylinder;

15

third connecting rod;

16

cylindrical tube; 17, internal thread.

Detailed Description of Preferred Embodiments

The present invention provides a multi-part cold extrusion reinforcement device and its method of use, which is described below in connection with the schematic structural illustrations of FIG 1 until 4 to be discribed.

Embodiment 1:

As in the 1 and 2 1, a multi-part cold extrusion reinforcing device provided by the present invention, as shown in FIG a first sleeve 4 for connection.

The first extrusion mandrel 1 and the second extrusion mandrel 3 are coaxially and detachably connected by the second sleeve 2, the third extrusion mandrel 5 and the second extrusion mandrel 3 are coaxially and detachably connected by the first sleeve 4, and the maximum diameter of the first extrusion mandrel 1, des of the second extrusion mandrel 3 and the third extrusion mandrel 5 gradually increases.

The first extrusion mandrel 1 consists of four parts along the axis: a guide section, an entry section, an extrusion section and a rear connecting pin, namely, the first extrusion mandrel 1 is as shown in FIG 2 shown, with a first cylinder 7, ie the guiding section, a first truncated cone 8, ie the input section, a second cylinder 9, ie the extrusion section, and a first connecting rod 10, ie the rear connecting pin, fixed and arranged coaxially from left to right , wherein the first connecting rod 10 has a first external thread opened at its periphery, the diameter of the second cylinder 9 is larger than the diameter of the first cylinder 7 and the diameter of the first cylinder 7 is larger than the diameter of the first connecting rod 10.

Further, the end surface of the first cylinder 6, the junction between the first cylinder 7 and the first truncated cone 8, and the junction between the first truncated cone 8 and the second cylinder 9 are all provided with rounded corners.
The second extrusion mandrel 3 and the third extrusion mandrel 5 have the same structure and both consist of five parts in the axial direction: a front connection pin, a guide section, an input section, an extrusion section and a rear connection pin, both consisting as in FIG 3 shown, of a second connecting rod 11, ie the front connecting pin, a third cylinder 12, ie the guiding section, a second truncated cone 13, ie the input section, a fourth cylinder 14, ie the extrusion section, and a third connecting rod 15, ie the rear connecting pin , which are firmly connected and arranged coaxially from left to right. The third connecting rod 15, the second connecting rod 11 and the first connecting rod 10 have the same diameter, the second connecting rod 11 and the third connecting rod 15 are provided with a second male thread on their periphery, the second male thread has the same design parameters as the first male thread; the diameter of the fourth cylinder 14 is larger than the diameter of the third cylinder 12, and the diameter of the third cylinder 12 is larger than the diameter of the third connecting rod 11.

Further, the end face of the third cylinder 12 opposite to the second truncated cone 13, the junction between the third cylinder 12 and the second truncated cone 13, and the junction between the second truncated cone 13 and the fourth cylinder 14 are all provided with rounded corners.

As in 4 shown, the first sleeve 4 and the second sleeve 2 have the same structure and both comprise a cylindrical tube 16, the inner wall of the cylindrical tube 16 being opened with an internal thread 17 mating with the second external thread. The internal thread 17 can simultaneously cooperate with the external threads on the first connecting rod 10, the second connecting rod 11 and the third connecting rod 15 to form a releasable mechanical connection, so that the the first extrusion mandrel 1, the second extrusion mandrel 3 and the third extrusion mandrel 5 are axially connected to form a multi-piece cold extrusion reinforcement device. The material of the coaxially arranged first extrusion mandrel 1, the second extrusion mandrel 3 and the third extrusion mandrel 5 is W18Gr4VCo5 tool steel with a mandrel working surface roughness Ra of 0.2-0.4 µm, and the material of the second sleeve 2 and the first sleeve 4 is 300M steel.

Furthermore, the axial length of the front (rear) connecting pin is greater than the length of the male thread.

Further, each guide section is cylindrical, for the first extrusion mandrel, the first cylinder 7 is axially connected at both ends to the end face of the first cylinder 6 and the first truncated cone 8, and there is a rounded transition at the junction between the end face of the first cylinder 6 and the first cylinder 7, for the other extrusion mandrels the guide sections are axially connected at both ends to the front connecting pin and the input section, and connected to the front connecting pin by a transition shoulder, the shoulder having a chamfer at its root and at the point where the shoulder is connected to the guide section, has a rounded transition.

Further, the diameter of the first cylinder 7 is slightly smaller than the diameter of the hole to be processed, the diameter of the guide portion of the second extrusion mandrel 3 is slightly larger than the diameter of the first cylinder 7 but smaller than the diameter of the second cylinder 9, the diameter of the Guide portion of the third extrusion mandrel 5 is slightly larger than the diameter of the guide portion of the second extrusion mandrel 3, but smaller than the diameter of the extrusion portion of the second extrusion mandrel 3; the diameter of the leading portion of the subsequent extrusion mandrel is always slightly larger than the diameter of the leading portion of the preceding extrusion mandrel, but smaller than the diameter of the extrusion portion of the preceding extrusion mandrel.

Further, the diameter of the input section gradually increases along the guide section to the extrusion section, which is a frustoconical structure, and the diameter of the small end of the input section is less than or equal to the diameter of the guide section, and the diameter of its large end is slightly larger than the diameter of the hole to be machined, and the difference between the diameter of the large end and the diameter of the small end of the first truncated cone 8 is slightly larger than the difference between the diameter of the large end and the diameter of the small end of the entrance section of the other extrusion mandrel.

Furthermore, each extrusion section described in the present invention is a cylindrical structure with a diameter equal to or slightly smaller than the diameter of the entry section to which it is attached and larger than the diameter of the hole to be machined.

There is also a shoulder at the junction of each rear connecting pin and the extrusion to which it is connected.

Further, the length of each extrusion mandrel plus sleeve is less than or equal to the sum of the thread lengths of the front connecting pin and the rear connecting pin of the extrusion mandrel.

• Auswählen eines geeigneten ersten Extrusionsdorns 1, eines zweiten Extrusionsdorns 3, eines dritten Extrusionsdorns 5, einer zweiten Hülse 2 und einer ersten Hülse 4; Verbinden des ersten Extrusionsdorns 1 und des zweiten Extrusionsdorns 3 mittels der zweiten Hülse 2 und Verbinden des zweiten Extrusionsdorns 3 und des dritten Extrusionsdorns 5 mittels der ersten Hülse 4 in einem axialen Satz, wodurch eine mehrteilige Kaltextrusion-Verstärkungsvorrichtung gebildet wird;
• Einspannen des dritten Extrusionsdorns 5 in die Antriebsvorrichtung, so dass die mehrteilige Kaltextrusion-Verstärkungsvorrichtung vertikal eingestellt ist;
• Befestigung der zu bearbeitenden Komponente mit offenem Loch an der Stützfläche, wobei das Loch nicht verdeckt wird und genügend Raum für den Durchgang der mehrteiligen Kaltextrusion-Verstärkungsvorrichtung bleibt;
• Verwenden des Schmiermittels, um die zu bearbeitende Oberfläche der zu bearbeitenden Komponente mit offenem Loch und die Oberfläche der mehrteiligen Kaltextrusion-Verstärkungsvorrichtung zu schmieren;
• Einsetzen des unteren Endes des ersten Extrusionsdorns 1 in das zu bearbeitende Loch, Aktivieren der Antriebsvorrichtung und Schieben des ersten Extrusionsdorns 1 durch das zu bearbeitende Loch, um die erste Kaltextrusion-Verstärkung der zu bearbeitenden Fläche der zu bearbeitenden Komponente mit offenem Loch durchzuführen;
• weiteres Schieben des zweiten Extrusionsdorns 3 durch das zu bearbeitende Loch Teil für Teil, um die zweite Kaltextrusion-Verstärkung der zu bearbeitenden Fläche der zu bearbeitenden Komponente mit offenem Loch durchzuführen;
• weiteres Schieben des dritten Extrusionsdorns 5 durch das zu bearbeitende Loch Teil für Teil, um die dritte Kaltextrusion-Verstärkung der zu bearbeitenden Fläche der zu bearbeitenden Komponente mit offenem Loch durchzuführen;
• Zurücksetzen in der entgegengesetzten Richtung und Zurückziehen der mehrteiligen Kaltextrusion-Verstärkungsvorrichtung nachdem die dreiteilige Kaltextrusion-Verstärkung abgeschlossen ist.

The method of using the multi-piece cold extrusion reinforcement device includes the following steps:

• selecting an appropriate first extrusion mandrel 1, second extrusion mandrel 3, third extrusion mandrel 5, second sleeve 2 and first sleeve 4; connecting the first extrusion mandrel 1 and the second extrusion mandrel 3 by means of the second sleeve 2 and connecting the second extrusion mandrel 3 and the third extrusion mandrel 5 by means of the first sleeve 4 in an axial set, thereby forming a multi-part cold extrusion reinforcement device;
• clamping the third extrusion mandrel 5 into the driving device so that the multi-part cold extrusion reinforcing device is adjusted vertically;
• attaching the component to be machined with an open hole to the support surface, leaving the hole unobscured and leaving sufficient space for the multi-piece cold extrusion reinforcement device to pass therethrough;
• using the lubricant to lubricate the machined surface of the machined open hole component and the surface of the multi-piece cold extrusion reinforcing device;
• Inserting the lower end of the first extrusion mandrel 1 into the hole to be machined, activating the driving device and pushing the first extrusion mandrel 1 through the hole to be machined to perform the first cold extrusion reinforcement of the surface to be machined machined component with open hole to perform;
• further pushing the second extrusion mandrel 3 through the to-be-worked hole piece by piece to perform the second cold-extrusion reinforcement of the to-be-worked surface of the open-hole component to be worked;
• further pushing the third extrusion mandrel 5 through the to-be-worked hole piece by piece to perform the third cold-extrusion reinforcement of the to-be-worked surface of the open-hole component to be worked;
• Backing up in the opposite direction and retracting the multi-piece cold extrusion reinforcement device after the three piece cold extrusion reinforcement is complete.

• (1) die Mehrteil-Loch-Extrusionsverstärkung für die Komponente mit offenem Loch aus TB6-Titanlegierung hat im Vergleich zur einmaligen oder zweimaligen Kaltextrusionsverstärkung eine größere Anzahl von Extrusionen, gleichmäßigere Kräfte an allen Teilen der Lochwand, eine geringere Oberflächenrauhigkeit, eine gleichmäßigere radiale Verteilung der elastisch-plastischen Verformungszone, langsamere Ermüdungsrisse und Rissausbreitungsraten um das Loch herum und eine effektivere Verstärkung der Ermüdungslebensdauer der Komponente mit offenem Loch;
• (2) die Erfindung erfordert keine zusätzlichen Einpressbuchsen oder offen geschlitzten Buchsen, um eine Beschädigung der Oberfläche der Lochwand zu vermeiden, und vermeidet auch Mikrobewegungs-Verschleißschäden an der Oberfläche der Lochwand durch die Buchsen, und eliminiert auch die Notwendigkeit für nachfolgende Reibvorgänge, um die Rauheit der Lochwand zu gewährleisten, was eine große Einsparung an Bearbeitungszeit bedeutet;
• (3) bei der vorliegenden Erfindung sind die Extrusionsdorne mechanisch miteinander verbunden, die Verbindung ist fester und kann größeren Belastungen standhalten;
• (4) bei der vorliegenden Erfindung können für eine bestimmte Lochgröße mit Ausnahme eines bestimmten ersten Extrusionsdorns andere Extrusionsdorne nach Bedarf modular kombiniert werden;
• (5) die Erfindung kann eine einmalige kontinuierliche Mehrteil-Loch-Extrusion in einem einzigen Positionierungszustand zur Verstärkung der Komponente mit offenem Loch verwendet werden, wodurch die Ermüdungslebensdauer der Komponente mit offenem Loch effektiv verbessert wird.

The advantageous effects of the present invention are as follows:

• (1) the multi-piece hole extrusion reinforcement for the TB6 titanium alloy open hole component, compared to the one-time or two-time cold extrusion reinforcement, has a larger number of extrusions, more uniform forces on all parts of the hole wall, less surface roughness, more uniform radial distribution of the elastic-plastic deformation zone, slower fatigue cracks and crack propagation rates around the hole, and more effective reinforcement of the fatigue life of the open-hole component;
• (2) the invention does not require additional press-fit bushings or open slotted bushings to avoid damage to the surface of the hole wall, and also avoids micro-motion wear damage to the surface of the hole wall through the bushings, and also eliminates the need for subsequent reaming operations to remove the to ensure roughness of the hole wall, which means a large saving in machining time;
• (3) in the present invention, the extrusion mandrels are mechanically connected, the connection is stronger and can withstand greater loads;
• (4) in the present invention, for a given hole size, other than a given first extrusion mandrel, other extrusion mandrels can be modularly combined as needed;
• (5) the invention can be used a one-time continuous multi-part hole extrusion in a single positioning state to reinforce the open hole component, thereby effectively improving the fatigue life of the open hole component.

The above disclosure is only a preferred specific embodiment of the invention, however, the embodiments of the invention are not limited thereto and any variation that can be considered by a person skilled in the art falls within the scope of the invention.

Claims (7)

A multi-piece cold extrusion reinforcement device characterized in that it comprises: a first extrusion mandrel; a plurality of second extrusion mandrels coaxially and detachably connected by a first sleeve, and the diameter of the latter second extrusion mandrel is larger than that of the former second extrusion mandrel, and the first extrusion mandrel is detachable by a second sleeve with the second extrusion mandrel having the smallest diameter connected. Multi-part cold extrusion reinforcement device according to claim 1 , characterized in that the first extrusion mandrel comprises: a first cylinder, a first truncated cone, a second cylinder and a first connecting rod sequentially fixed and arranged coaxially, the first connecting rod having a first external thread open at its periphery, the second cylinder has a larger diameter than the diameter of the first cylinder, the first cylinder has a larger diameter than the diameter of the first connecting rod. Multi-part cold extrusion reinforcement device according to claim 2 , characterized in that the end surface of the first cylinder remote from the first truncated cone, the connection between the first cylinder and the first truncated cone and the connection between the first truncated cone and the second cylinder are all provided with rounded corners. Multi-part cold extrusion reinforcement device according to claim 2 , characterized in that the second extrusion mandrel comprises: a second connecting rod, a third cylinder, a second truncated cone, a fourth cylinder and a third connecting rod which are sequentially fixed and arranged coaxially, the third connecting rod, the second connecting rod and the first Connecting rod have the same diameter, the second connecting rod and the third link rod has a second external thread on its circumference, which has the same structural parameters as the first external thread, the fourth cylinder has a larger diameter than the diameter of the third cylinder, the third cylinder has a larger diameter than the diameter of the third connecting rod. Multi-part cold extrusion reinforcement device according to claim 4 , characterized in that the end surface of the third cylinder remote from the second truncated cone, the connection between the third cylinder and the second truncated cone and the connection between the second truncated cone and the fourth cylinder are all provided with rounded corners. Multi-part cold extrusion reinforcement device according to claim 4 , characterized in that the first sleeve and the second sleeve have the same structure and both comprise a cylindrical tube, the inner wall of the cylindrical tube being opened with an internal thread matching the second external thread. Method of using the multi-piece cold extrusion reinforcement device claim 1 , characterized in that it comprises the steps of: selecting an appropriate first extrusion mandrel, a plurality of second extrusion mandrels, a first sleeve and a second sleeve; connecting a plurality of second extrusion mandrels through said first sleeve in twos removably coaxial, the latter second extrusion mandrel having a diameter greater than that of the former second extrusion mandrel; and connecting the first extrusion mandrel through the second sleeve to the second extrusion mandrel having the smallest diameter in an axial series, thereby forming a multi-piece cold extrusion reinforcement device; clamping the second largest diameter extrusion mandrel into the drive assembly so that the multi-piece cold extrusion augmentation assembly is vertically adjusted; attaching the component to be machined with an open hole to the support surface, leaving the hole unobscured and leaving sufficient space for the multi-piece cold extrusion reinforcement device to pass therethrough; using the lubricant to lubricate the machined surface of the machined open hole component and the surface of the multi-piece cold extrusion reinforcing device; Inserting the lower end of the first extrusion mandrel into the hole to be machined, activating the driving device and pushing the first extrusion mandrel through the hole to be machined to perform the first cold extrusion reinforcement of the machined face of the open-hole component to be machined, and further pushing the second extrusion mandrels through the hole to be machined piece by piece to perform the multi-piece cold extrusion reinforcement of the surface to be machined; resetting in the opposite direction and retracting the cold extrusion multi-piece reinforcement device after the cold extrusion multi-piece reinforcement is complete.

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