HU208266B - Method for producing workpieces having hollow of variable size first micro-shuttle houses - Google Patents

Abstract

The workpiece (9) is forced into a ring (1) using a mandrel (4), until it is held by jaws (5), which then pull it further. - Typically a mandrel of varying cross-section is used, which is moved up and down as required to form the various parts of the internal cavity.

Description

FIELD OF THE INVENTION The present invention relates to a process for producing workpieces having variable-sized cavities, in particular micro-wool housings, by means of a plastic cold forming process wherein the workpiece is pushed through a ring by a mandrel and then moved downwardly.

One of the ponds in the development of knitting machines is to reduce the weight of the knitting machine. The weight of the weft determines the length of the weft yarn that can be spun in a unit of time.

Micro-ropes currently used weigh 60 grams and 40 grams, respectively. In conventional micro-warps, the cavity inside the micro-warp housing has a constant cross-section along its length. (Rudolf Szabó: Weaving Machines, pp. 72-99)

SUMMARY OF THE INVENTION It is an object of the present invention to provide a process for the production of micro-ropes of reduced weight while maintaining their external dimensions. This can be accomplished by reducing the wall thickness of the microfibre housing. However, due to the need for riveting or the necessary guiding of the spring, the original sheet size of the cavity extending along the inside and outside of the cavity along the length of the housing, however, may be reduced in the middle section. Therefore, the object of the present invention has been accomplished by a method of moving the workpiece through the flow ring between the gripping jaws with a variable cross section, preferably a stepped mandrel, and then moving the workpiece further by pulling the gripping jaws. - moving it forward and backward in stages.

Preferably, the length of each cavity portion is controlled by adjusting the forward and backward movement of the mandrel of variable cross-section.

Preferably, for a cavity size smaller than the mandrel strength limit, a technological protrusion is formed on the workpiece, which is inserted directly into the gripping jaws through the flow ring, and the step mandrel is pushed with a thrust that is below its strength tolerance.

By the process of the present invention, the weight of the micro-weft was reduced by 10-12% compared to the conventional one.

DETAILED DESCRIPTION OF THE INVENTION The invention will be described in more detail with reference to the drawings, which illustrate certain steps of the process of the invention.

Figure 1 shows the workpiece inserted into the apparatus during the initial phase of the process.

Figures 2, 3, 4, 5 show the workpiece in successive stages of the process.

Figure 6 shows the last step of the process.

As shown in Fig. 1, the flow ring (1) is biased into the housing shell (2) of the tool, which is secured from above by the centering ring (3).

The mandrel of the device (4) has a variable cross-section, preferably stepped, having a smaller part (7) and a larger part (8) connected thereto. The cross-sectional dimensions of each portion (7, 8) of the stepped mandrel (4) determine the exact cross-sectional dimensions of the cavity portions (10, 11, 12) of the workpiece (9).

The insertion of the workpiece (9) into the tool is illustrated in Figure 1. The workpiece (9) is inserted into the centering ring (3) and then moved downwardly by the mandrel (4) across the flow ring (1) so that the smaller portion (7) of the mandrel (4) reaches the flow ring (1). the narrowest (6) calibration part. The end of the workpiece (9) is now located between the jaws (5). This state is shown in Figure 2.

The third phase of the technological process is shown in Figure 3.

At this point, the mandrel (4) stands and the gripping jaws (5) move downward and pull the workpiece (9) through the flow ring (1). The inner cavity (10) of the workpiece (9) is then formed.

When the inner cavity (10) has reached a sufficient length, the fourth technological phase, shown in Figure 4, follows. The stepped spike (4) then starts down again until a larger portion (8) reaches the calibration portion (6) of the flow ring (1) and stops there. Meanwhile, the jaws (5) move continuously downwards.

The fifth phase of the technological process starts when the stepped (4) spike has stopped in the previous fourth phase. The gripping jaws (5) continue to move downward until the appropriate length of the central cavity (11) of the workpiece (9) is formed. This phase is shown in Figure 5. This technological phase ends by stopping the jaws (5).

Then comes the sixth technological phase shown in Figure 6. The stepped mandrel (4) then moves upwards until the smaller portion (7) reaches the calibration part (6) of the flow ring (1). At this point, the mandrel (4) stops and the jaws (5) start down again. This is illustrated in Figure 6.

The gripping jaws (5) then move continuously downwards until the workpiece (9) is completely pulled over the flow ring (1). In this phase, the outer cavity (12) of the workpiece is formed.

Thereafter, the stepped mandrel (4) returns to its upper end position, the jaws (5) open in the lower end position and the workpiece (9) can be removed.

The length of the cavity portions (10, 11, 12) of the workpiece (9) can be adjusted by means of the coupling strips of the apparatus.

The structure of the device is such that the stepped mandrel (4) and the gripping jaws (5) are moved by two independently controlled hydraulic cylinders.

In cases where the stepped mandrel (4) is rigidly incapable of pushing the workpiece (9) through the flow ring (1), a technological protrusion (20) is formed on the workpiece (9) which passes through the flow ring (1). and can be inserted directly between the jaws (5). This technological projection (20) is depicted in dashed line in FIG.

In this case, the stepped mandrel (4) is pushed with a force below its strength tolerance.

Claims (4)

PATENT CLAIMS A method for producing workpieces having variable-sized cavities, in particular micro-wool casings, by means of a plastic cold forming process, wherein the workpiece is moved by a mandrel through a flow ring between the jaws and then pulled downwardly. on the flow ring, while the stepped mandrel is moved forward and backwardly in stages according to the length of the cavity sections of different sizes. Method according to claim 1, characterized in that the length of the cavity portions is controlled by adjusting the forward and backward movement of the mandrel of variable cross-section. Method according to Claim 1 or 2, characterized in that, at a cavity size smaller than the strength limit of the stepped mandrel, the workpiece is formed with a technological projection which is inserted directly between the jaws through the flow ring, 10, and the step pin is pushed with a thrust below its strength tolerance.