EP0838545B1 - Knitting tool for textile machines and method for its manufacturing - Google Patents

Description

The invention relates to processes for the production of Knitting tools using a stamped blank (Punch blank) is assumed. Also concerns the Invention a punched knitting tool with rounded, beveled or broken edges. Under "knitting tools" there are latch needles, point needles, sliding needles, Needles without tongue, for example plush hooks for manufacturing of plush goods, as well as boards and the like understand.

The knitting tools mentioned are usually large To produce a number of pieces of consistently good quality. This particularly affects the edges of the knitting tools, in contact with the thread to be knitted come or the corresponding with or channel walls Needle channels are in contact and related these are moved.

DE 26 37 078 describes one method and one Device for processing the foot of punched knitting or Knitting machine needles are known. Starting from one The raw edge of the stamped part becomes one Milling process machined, the desired foot shape is achieved. The needle foot can do this on his in touch with the lock of the knitting machine standing top and bottom edges rounded or beveled become.

Also deals with the shape of the needle foot DE 29 11 195 C2, accordingly the needle foot in one Embossing processing step with groove-like depressions or grooves that extend over the entire length of the needle foot extend over its flat sides. One too stamping tool created for this purpose takes the foot of the raw-punched needle from a steel band and presses when closing in the flat sides of the needle foot the mentioned wells. Die when punching the Needlefoot's previously created fracture surfaces become squeezed outwards and converted into a predetermined shape. The rest of the needle is not from the embossing process affected.

DE 44 42 943 C1 is a punched knitting tool known that a shaft with plastic-filled Has openings. In the essentially striped Shaft are elongated, slit-like openings formed, the marginal edges of both sides of the Openings are crimped to form a positive To enable attachment of the plastic filling. At the The edges are squeezed from both sides the flat strip-shaped shaft towards each other pressed, causing the material flowing towards each other the wall of the slit-shaped opening is deformed. Between the so bevelled opening edges is the Diaphragm wall concave.

From DE 34 01 874 A1 it is used for the production of Knitting needles known, embossing and punching processing steps, that affect the needle shaft combined perform. In particular, the needle shaft wells to be accommodated before punching out the Embossed in the metal band in question, what is associated with material displacement. The dimensions the punching step that sets the needle is as follows executed to the needle with the desired raw outer contour to obtain. Arising breaklines are shown below eliminated or accepted.

Proceeding from this, it is an object of the invention Knitting tool and a method to create themselves in the manufacture of knitting tools, machining edges Avoid or remove burrs.

This task is accomplished through the procedures with the Features of claim 1 or 5 and by a Knitting tool with the features of claim 8 solved.

The common, underlying principle is included both methods in that edge areas before or after another shaping process, such as milling or punching by means of embossing, rounded, chamfered or otherwise broken. According to claim 1 is one by punching out the blank resulting sharp edge or a corresponding one Burr removed by embossing. For this, the punch blank into the engraving of a corresponding embossing tool laid and shaped in it. The engraving, that is the Receiving space of the embossing tool for the blank, is dimension so that protruding or sharp edges of the blank to be pressed in, being in the edge area a flow of material towards the center of the blank is obtained. The edge area and the subsequent, also affected by the forming process Surface areas are solidified. This can improve the durability of a needle made in this way.

The geometry of the Knitting tool set relatively precisely. The cross section the knitting tool is based on the shape of the engraving of the embossing tool defines and agrees with this. In particular in the edge area, inclined surfaces or facets are formed. The one obtained by embossing Edge geometry enables significantly improved Sliding properties of the faceted knitting tools in corresponding guide channels of knitting or knitting machines. Compared to conventional polishing or grinding processes to remove machining burrs with the molding process step more reproducible Contours reached. The knitting tools tend less to damage duct walls and displace that Less lubricant.

Although it can be sufficient in principle, a blank only in sections of the stamping processing step to undergo, in addition to the beveled Areas, that is, the edges, also adjoining Areas, for example the flat sides of the blank, embossed. The embossing tool preferably takes the entire blank, so that it is shaped overall becomes. This will become the later knitting tool, if present, also in the area of his foot, surface hardened and deburred at the same time.

The with respect to a longitudinal median plane of the blank naturally unsymmetrical after punching Cross section is in a largely symmetrical, Convex shape. In addition to the ridges, the Fractured surfaces smoothed. This is particularly advantageous if it affects areas that are in use subject to high surface tensions. The cracking as a result of permanent stress can be reduced be, which increases the life of the knitting tool can be increased.

In the stamping processing step, the blank can be punched also give a shape to the damage the one to be knitted with the knitting tool Excludes thread. The stamping processing step can both, as mentioned above, after punching out the Stamped blanks are run to existing sharp ones Blunt edges, as well as before cutting Processing step. This is, for example, during production of latch needles of importance in which in the Needle slit a slot to accommodate a movable stored tongue must be trained. The slot will usually milled into the blank in question, with sharp edges on the edge of the milled slot arise. In the method according to the invention is previously embossed at least one obliquely flanked groove into the blank. The groove bottom is the next Milling process deepened, after which a breakthrough is formed can be. The flanks of the embossed groove then form the edge of the slot, which is therefore free of sharp Edges is. While with conventional polishing or Grinding the edges of the slot because of the small slot width are largely inaccessible an effective edge rounding with the embossing processing step reached.

The embossing processing step can be on two each other opposite narrow sides of the needle blank be executed so that the slot to be trained has rounded edges on both sides.

Through the stamping processing step, a Solidification of the material of the knitting tool in the area the edge of the slot is reached. This has in particular meaning with latch needles. The one in the slot stored tongue swings in time with the needle movement one end stop to the other. As a result of circular knitting machines superimposed on the longitudinal movement of the needle Rotary movement of the needle cylinder becomes the open and closed Tongue alternately by the Coriolis force to the opposing slot flanks pressed. Due to the solidified material surface during the molding excessive wear is prevented here, which otherwise increase the side play of the tongue would. If the game exceeds a maximum, the tongue can get caught on the hook, causing the Needle becomes unusable.

The embossing processing step can be done with two dies as well as with correspondingly profiled ones Roles are performed. These are then mechanical or electronically guided on curves or they are with a predetermined force is pressed against the blank, whereby the desired depth of penetration is automatic established.

Both when embossing the outer edges and when The shape of the slot edges becomes the relevant outer contour the knitting tool through non-cutting processing steps established. The embossing direction, that is, the Direction in the area of the bevelled edges mainly material is moved in both cases aligned approximately to the center of the cross section.

A punched knitting tool has on its outer contour especially at least one in the edge area Embossed area that is free of sharp edges. Form the embossing areas or the outer edges of the Knitting tool, runs a corresponding knitting tool low-friction in assigned guide channels and treated Threads to be processed are gentle in the thread sliding area.

Is the knitting tool using a knitting machine needle Needle foot, can with the stamping processing step especially in the transition area from the needle foot to the shaft is removed by a Material consolidation can be achieved. Will those at Punch out the blank in this area sharp edges are embossed in the edge area existing microcracks rendered ineffective, which the otherwise dynamic strength of the knitting tool could degrade.

Further features of advantageous embodiments of the inventive method and the inventive Knitting tools are the subject of subclaims.

Fig. 1

eine Zungennadel in einer schematisierten Seitenansicht,

Fig. 2

einen Rohling zur Herstellung einer Zungennadel nach Fig. 1, in einer schematisierten Seitenansicht,

Fig. 3

eine im Nadelbrustbereich geschnittene Zungennadel in ausschnittsweiser, vereinfachter Darstellung,

Fig. 4

einen Stanzrohling (ausgestanzter Rohling) vor einem späteren Formprägebearbeitungsschritt, in schematisierter Darstellung, im Querschnitt,

Fig. 5

den Prägerohling (formgeprägter Rohling nach Fig. 2), in einer schematischen Darstellung, im Querschnitt,

Fig. 6

ein Prägewerkzeug zur Durchführung eines Formprägebearbeitungsschrittes an dem Stanzrohling nach Fig. 4, in schematisierter Darstellung, im Querschnitt,

Fig. 7

den Rohling nach Fig. 2 vor Ausbildung des Längsschlitzes und nach einem Formprägebearbeitungsschritt, in schematisierter Darstellung, im Querschnitt und in einem anderen Maßstab,

Fig. 8

den Rohling nach Fig. 7, versehen mit einem Längsschlitz im Nadelbrustbereich, in einer schematisierten Darstellung, im Querschnitt, in einem anderen Maßstab,

Fig. 9

eine Vorrichtung zur Durchführung eines Formprägebearbeitungsschrittes an einem Rohling für eine Zungennadel, in Seitenansicht, in stark schematisierter Darstellung, und

Fig. 10

eine alternative Vorrichtung zur Durchführung des Formprägebearbeitungsschrittes an einem Rohling für eine Zungennadel, in schematisierter Darstellung, in einer Seitenansicht.

Exemplary embodiments of the invention are shown in the drawing. Show it:

Fig. 1

a latch needle in a schematic side view,

Fig. 2

2 shows a blank for producing a latch needle according to FIG. 1, in a schematic side view,

Fig. 3

a tongue needle cut in the area of the needle chest in a partial, simplified representation,

Fig. 4

a punch blank (punched blank) before a later embossing processing step, in a schematic representation, in cross section,

Fig. 5

the embossing blank (shaped blank according to FIG. 2), in a schematic representation, in cross section,

Fig. 6

4, in a schematic representation, in cross section, a stamping tool for carrying out a stamping machining step on the punch blank according to FIG.

Fig. 7

2 before the formation of the longitudinal slot and after a shaping step, in a schematic representation, in cross section and on a different scale,

Fig. 8

7, provided with a longitudinal slot in the needle chest area, in a schematic representation, in cross section, on a different scale,

Fig. 9

a device for performing a compression molding step on a blank for a latch needle, in side view, in a highly schematic representation, and

Fig. 10

an alternative device for performing the embossing processing step on a blank for a latch needle, in a schematic representation, in a side view.

The one shown in Fig. 1 as a knitting tool serving tongue needle 1 each has a head or Hook 2, which is followed by a neck 3, which in a needle breast 4 passes over. In their area is a arranged longitudinal slot 6, for example, in which a needle tongue 7 is pivotable about a bearing 8 is stored.

The needle breast 4 closes via a throat 9 a shaft 11 which, when using the needle in a Needle channel of a knitting machine is added. The one with Shaft 11 provided with a plurality of recesses 12 instructs its end 13 remote from the hook 2 has a foot 14 on. The foot 14 is in one piece on the. Shaft 11 formed and extends at right angles to the longitudinal direction 16 the latch needle 1. The foot 14 goes with it arcuate transitions 17, 18 into the shaft 11.

The latch needle 1 has two mutually parallel Flat sides 21, 22, between which narrow sides, namely Needle top 23 and needle back 24. How 3 shows are between the top of the needle 23 and the flanks 21, 22 transition regions 26, 27 are provided, which are somewhat rounded and somic not sharp-edged Form transition. Corresponding transition areas 28, 29 are between the needle back 24 and the lateral flanks or flat sides 21, 22 are provided.

The longitudinal slot 6 is on the top of the needle 23 lying mouth of inclined flanks 31, 32 limited that without sharp edges in the top of the needle 23 pass over. Corresponding inclined flanks 54, 55 can on the underside in the transition to the needle back 24 be provided.

For the manufacture of the latch needle 1 by a Fig. 2 illustrated punch blank 33, the has been punched out of a thin steel strip. His Outer contour, that is its outline 34, is due to that Die set essentially. To the outer contour 34 include both the flanks 21, 22 (Fig. 4) as also the needle top 23 and the needle back 24. After the punching of the blank 33 from the steel strip this with respect to its parallel to the flat sides 21, 22. The longitudinal center plane 36 is initially asymmetrical. While on the upper side in FIG. 4 along the contour 34 of the blank 33 ridges 37 are formed is his Feed side 38 (bottom in Fig. 4) rounded. The in between Fractures 39 are uneven and mostly not exactly at right angles to the flat sides 21, 22.

At least the ridge 37, which is about the ridge height G rises above the flat side 22 to remove is an in Fig. 6 illustrated embossing tool 41 provided from an upper tool 41a and a lower tool 41b exists and with which the punch blank 33 in an embossing blank 33a is transferred. One in the embossing tool 41 trained engraving 42 corresponds in shape to that machined embossing blank 33a, from which the base body the latch needle 1 is formed. The light inner Width W of the engraving 42 of the embossing tool 41 is the same closed stamping tool 41 with the thickness D of the blank 33 matches or is at most insignificant lower.

A corresponding edge deformation of the punch blank 33 can be reached in the upper tool 41a and the lower tool 41b at the edges of the engraving 42 rounded edge regions 44, 45, 46, 47 are formed. Otherwise, the engraving 42 is limited by flat surfaces. A punch blank 33 inserted into the engraving 42 is therefore in particular when closing the embossing tool 41 deformed in the area of its outer edges, its Thickness D remains essentially unchanged. The punch blank 33 is related to that shown in FIG the longitudinal center plane 36 is essentially symmetrical Form (embossing blank 33a with outer contour 34a) transferred. Both the ridges 37 and the feed side 38 are carried out in the embossing tool 41 Shape embossing process deformed, the transition areas 26, 27, 28, 29 have been formed with radii that predetermined by the edge areas 44 to 47 of the engraving 42 are. The material flow direction is based on the 4 and 5 illustrated cross-sectional area about diagonally to the center of the cross section.

A stronger deformation of the punch blank 33, at the fracture surfaces 39 by flowing the material can be smoothed is possible. Be independent of it defined by the embossing process rounded or beveled edge areas reached that are solidified. This applies both to edges in the thread sliding area of the neck 3, the needle chest 4 and the throat 9 as well as for the edges of the shaft 11. The edge rounding in the thread sliding area improves the properties the latch needle 1 in terms of treatment a thread during the knitting process. The rounding the edges of the shaft improve the running properties the latch needle 1 in the needle channel. The surface hardening achieved is an advantage in both cases.

Through the stamping processing step in particular the dynamic strength of the foot 14 positive affected. This is achieved by in the stamping processing step especially the arched transitions 17, 18 shaped between shaft 11 and foot 14 become. The surfaces and edges in question continuously smoothed or rounded, so that the foot 14 is able to cope with higher dynamic continuous loads. At the The molding process becomes microscopic surface irregularities eliminated and the surface is particularly in the Area of transitions 17, 18 smoothed.

In the further processing sequence, the blank is embossed 33a of the longitudinal slot 6 is formed. To round off or blunting of the longitudinal slot 6 delimiting Edges is used in the manufacture of the latch needle 1 Needle chest 4 die stamping processing step inserted. The longitudinal slot 6 shown in FIG. 8 is in its central area by parallel to each other Slotted edges 51, 52 delimited, being on the top of the needle 23 of the latch needle 1, the oblique flanks 31, 32 connect to this. Accordingly, are on the back of the needle 24 inclined flanks 54, 55 formed that like that Sloping flanks 31, 32 together form an acute angle α of 60 °, for example. The plan trained in the example Sloping flanks 31, 32; 54, 55 can also be rounded and arranged at a different angle to each other his.

To form the inclined flanks 31, 32; 54, 55 are used in Figs. 7 and 9 illustrated dies 57, 58. while the upper die 57 in its Longitudinal direction of curvature of the embossing blank 33a in the area the neck 3 and the needle chest 4 is adapted it has a trapezoidal cross-section with a narrow forehead 59, the width of which is somewhat smaller than the distance of the slot flanks 51, 52 from each other The corresponding lower die 58 is in cross section also trapezoidal, but the Needle back 24 is correspondingly straight.

During the stamping process, the stamping dies 57, 58 towards the embossing blank 33a held between them moves so that they both on the needle top 23 also on the needle back 24 each in cross section trapezoidal longitudinal groove 61, 62 in the embossing blank 33 molding. The transition to the top of the needle 23 and the edges 63, 64 of the needle back 24 not sharp, but rather rounded. The Outer contour 34a is including the outer one Transitional areas 26, 27, 28, 29 and edges 63, 64 exclusively defined by non-cutting processing steps.

Following the molding process step a part of the longitudinal slot 6 starting from the longitudinal groove 61 milled into the vicinity of the longitudinal groove 62, initially a thin slotted bottom remains. In one yourself subsequent punching process the slot bottom is broken through, an opening 60 is formed. The The resulting longitudinal slot 6 has, for example, the one indicated at 65 Contour (Fig. 9). By preforming the longitudinal groove 61, 62 before the actual machining of the Slot 6 not only the slot edges are broken or rounded, but beyond that the material solidified at the edge of the slot. This will make the edges provided for receiving and storing the needle tongue 7 Slit less prone to wear against that in Operation reciprocating needle 7.

There are also knitting machine needles with no breakthrough 60, in the manufacture of the latter punching process and the shaping of the longitudinal slot 62 is omitted.

Instead of the dies 57, 58, the in 10 illustrates rollers 71, 72 for use come. These have on their respective outside trapezoidal profile. For the formation of the longitudinal groove 61, 62 becomes the blank 33, 33a between the rollers 71, 72 carried out that this in the top of the needle 23 and push in the needle back 24, or the rollers 71, 72 are guided along the blank 33, 33a. there the roller 72 moves on a straight path 73, while the roller 71 on a corresponding to the needle contour curved path 74 is guided. After training the Grooves 61, 62 are further processed as above described.

Regardless of whether the groove 61, 62 with the dies 57, 58 or with the rollers 71, 72 are, they gradually run out at their ends, what through corresponding inclined surfaces 76, 77 on the end faces of the Stamp 57, 58 or by appropriate delivery the rollers 71, 72 can be reached.

In the manufacture of knitting tools 1 these from a semi-finished product, such as a steel band, punched out. The punch blanks 33 thus created become subjected to a stamping processing step in which existing sharp edges scanned during punching, in particular ridges 37, by plastic deformation of the Punch blank 33 can be eliminated. For example. in the preparation of the embossing step goes from needle slots in the machining sequence a cutting Processing step, such as a milling process, ahead. But there may also be cases where it is appropriate is to first mill and then to emboss. In the blank a depression 61 is first embossed, the Soil is then removed until the desired one Deepening is obtained. The previously in the Form stamping processing step included the edge of the This allows deepening without further post-processing of sharp edges. Deburring is not necessary. Additional benefits can be gained from those in the stamping processing step material solidification achieved be achieved.

Claims (9)

1. Method for the production of knitting tools (1) for textile machines, in particular hosiery or knitting machines, wherein a punching blank (33) is punched out of a semifinished product and wherein at least one sharp burr (37) resulting on the outer contour (34) or a sharp edge (38) is rounded off or bevelled at least in sections,
   characterised in that
   for rounding off or bevelling the burr (37) and/or the edge (38) of the outer contour (34) a form stamping step is conducted, in which the burr (37) and/or the sharp edge (38) are removed completely or in sections by stamping.
2. Method according to Claim 1, characterised in that moreover during the form stamping step regions (21, 22, 23, 24), which are adjacent to the region (26, 27, 28, 29) to be bevelled, are stamped.
3. Method according to Claim 1, characterised in that during the form stamping step the punching blank (33) is transformed into a stamping blank (33a), the cross-sectional contour of which is determined by the stamping tool (41).
4. Method according to Claim 1, characterised in that during the form stamping step the burr (37) and/or the edge (38) is deformed towards the centre of the cross-section and the material flux in this region occurs in this direction, wherein an essentially convex cross-sectional structure is formed.
5. Method for the production of knitting tools (1) for textile machines, in particular hosiery or knitting machines, wherein in a machining step a depression or a slot (6) is formed with an edge (31, 32) bordering this on a blank (33, 33a),
   characterised in that
   a form stamping step, wherein a groove (61) with sloping or rounded flanks (31, 32) at least in sections is firstly formed in the blank (33, 33a), is conducted before the machining step for rounding off or bevelling the edge (31, 32) of the slot (6).
6. Method according to Claim 5, characterised in that the groove (61) formed by non-cutting is at least deepened during the machining so that parallel walls (51, 52), pointing towards one another and adjoining the flanks of the groove (61) are generated.
7. Method according to Claim 5, characterised in that the groove (61) is formed by means of at least one stamping die (57) or a correspondingly profiled roller (71).
8. Punched knitting tool (1) for textile machines, in particular hosiery or knitting machines, with a base body formed by a punched part, which has a stamping region (26, 27, 28, 29, 31, 32, 54, 55) at least on its outer contour (34a), characterised in that it has a flat blade (11) and a butt (14) formed in one piece thereon, which respectively have two parallel flat sides (21, 22) and narrow sides (23, 24) connecting these, that the stamping regions (26, 27, 28, 29) are formed in the transition area between the narrow sides (23, 24) and the flat sides (21, 22), and that a transition area (17, 18) having edges defined by the stamping regions is provided between the blade (11) and the butt (14) extending essentially at right angles thereto.
9. Knitting tool according to Claim 8, characterised in that the knitting tool (1) has at least one head region with a slot (6), and that the stamping region (31, 32) is provided on the slot (6) and forms its boundary at least in sections.

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