CN1928172A - Pressing roller holder for stretching structure - Google Patents

Abstract

The invention relates to a pressure roller support for fixing double pressure rollers in a drafting mechanism, which comprises a spring for pressing the double pressure rollers and a fixing frame for the double pressure roller shafts. The holder is a die-cast or injection-molded part, wherein the holder is cast onto the spring. Furthermore, the invention relates to a method for producing the pressure roller support, in which the spring is introduced into the mold at least in a partial region, so that the holder is connected to the spring during the casting process.

Description

Pressure roller bracket for drafting unit

technical field

The present invention relates to a pressure roller support for fixing the double pressure rollers in the drafting mechanism, which comprises a spring for pressing the double pressure rollers and a fixing frame for fixing the roller shafts of the double pressure rollers, wherein the The holder is cast as a die-cast or injection-molded part.

Furthermore, the invention relates to a method for producing a roller support for fixing the double pressure rollers in the drafting mechanism, wherein a spring pressing the double pressure rollers is associated with a fixing frame for the roller shafts of the double pressure rollers. connected, and wherein the holder is cast in a mold as a die-cast or injection-molded part.

Background technique

Such a pressure roller support is disclosed in DE 38 23 872 A1. In this known pressure roller support, the fastening frame is produced in a known manner as an aluminum die-cast part and is fastened to the spring by riveting. The joining process of riveting has large tolerances. It is therefore necessary to fasten the springs in a device with riveted mountings and to chip the mountings in the area of later fixing the roller shafts of the double pressure rollers. The subsequent positioning of the double press rollers precisely parallel to the associated lower roller of the drafting mechanism is ensured by chipping the mounting frame. A disadvantage of this known pressure roller holder is that its production is very complex and involves many different work steps.

Contents of the invention

The object of the present invention is to provide a pressure roller support of the type mentioned at the outset and a method for its production which is much simpler and involves fewer steps.

This task is solved with respect to the pressure roller support by casting the holder onto the spring. On the method side, this object is solved by inserting at least one partial region of the spring into the mold and connecting the fastening frame to the spring during the casting process.

By casting the fixing bracket directly on the spring in a die-casting or injection mould, the subsequent step of fixing the fixing bracket to the spring by riveting can be omitted. As a result, processes which lead to the greatest tolerances on the finished press roller holder can be excluded. The fastening frame is thus attached to the spring with high precision, so that in most cases a subsequent chip machining of the fastening frame in the region of the later fastening of the roller shaft of the double pressure roller can be omitted. The machining of the pressure roller bracket is thus simplified. In addition, it is more economical to manufacture.

In order to increase the positioning accuracy of the fixing bracket on the spring, it is advantageous to orient the positioning lugs of the spring provided for the active state relative to the mold during the casting process.

In an embodiment of the invention, a fastening element for the roller shaft of the double pressure roller is advantageously integrated into the fastening frame. This integration can take place by casting a bow spring riveted according to the above-mentioned prior art directly into the holder. It is likewise possible to place the bow springs in the mold and thereby connect the holder during the casting process.

However, the embodiment of the fastening element as a clip is particularly advantageous. Since the clips are formed during the casting of the holder by shaping the corresponding mold, this additional component of the bow spring can be dispensed with.

It is also advantageous if the fastening frame is made of a material with good castability, such as aluminium, zinc, magnesium or alloys thereof. In particular, it can be provided that the fastening frame is at least largely made of plastic. This makes it very easy to realize, in particular, the design of the fastening element as a clip. Here too, provision can be made to add to the plastic material for strength, such as glass fibers, to a large extent.

Description of drawings

Additional advantages and features of the invention emerge from the following description of several exemplary embodiments.

The accompanying drawings show:

Fig. 1 is a partial sectional side view of a pressure roller bracket fixed on a load arm;

Fig. 2 is a partial sectional view of the pressure roller support in the arrow II direction of Fig. 1;

Fig. 3 is a view similar to Fig. 1 in another structural scheme of the pressure roller support.

Detailed ways

1 and 2 partially show a drafting mechanism, in particular a load arm 1 of a drafting mechanism for a ring spinning machine. The load arm 1 has a U-shaped profile 2 . The load arm is supported at its not-shown end on a support rod parallel to the lower rollers of the drafting mechanism, one of which is shown here as the lower roller 9 . The load arm 1 is guided on a support rod and is rigidly constructed such that it can pivot in a plane perpendicular to the lower roller 9 . The load arm 1 supports a plurality of upper rollers in the form of double pressure rollers 6 , of which only one double pressure roller 6 is shown, and which are allocated in corresponding numbers to the lower rollers. The double pressure roll 6 comprises two roller core top rollers which are supported on a common roller shaft 7 and which is clamped between these two roller core top rollers. The fiber strands 10 run between each upper and lower roll 9 of the double pressure rollers 6, and the fiber strands are drawn to the desired fineness in the drafting mechanism. In order to adapt the drafting mechanism to the fiber material, it is necessary for the double pressure roller 6 to be adjustable in the running direction of the fiber strand 10 , ie in the longitudinal direction of the load arm 1 . Furthermore, it is also important to align the double pressure roll 6 as precisely as possible parallel to the lower roll 9 .

The roller shaft 7 of the double pressure roller 6 is arranged in a holder 8 which has an approximately semi-cylindrical recess. The roller shaft 7 is fixed in the recess by means of a fixing element 11 , which in the illustrated embodiment is a bow spring 25 .

The fixed frame 8 of the roller shaft 7 is fixed on a spring 12, which is preferably a leaf spring. As an alternative, the spring 12 can also be a helical spring in another embodiment. According to the invention, the fastening frame 8 is produced as an injection-molded or injection-moulded part, the fastening frame 8 being cast directly onto the spring 12 . The spring 12 is inserted into the mold either entirely or at least in a partial region 13 before the casting process and is surrounded by the material when it is injected into the mold. It is advantageous here if this partial region 13 of the spring 12 has a recess 27 or a small hole 28 in order to produce a fixed connection between the mounting 8 and the spring 12 . Here too, the bow spring 25 is inserted into the mold and connected to the holder 8 during the injection molding or injection molding process.

The spring 12 has a hairpin-shaped curved section in the region facing away from the mounting bracket 8 , in which the spring 12 is fastened in a spring carrier 15 which itself is also clamped to the contour 2 of the load arm 1 middle. The spring carrier 15 likewise has a U-shaped contour that opens out towards the lower roller 9 . In its transverse web 16 a threaded part 19 is screwed, while the threaded part 19 passes through the transverse web 3 of the profile 2 in a longitudinal slot, so that the spring carrier 15 can be moved and fixed in the longitudinal direction of the load arm 1 .

The spring 12 is provided on a leg 14 of the hairpin section with two opposite lugs 22 , 23 which are inserted into downwardly open slots of the limbs 17 , 18 of the spring holder 15 In the shape holder 29. In the region of the two webs 22 and 23 , a clamping piece 30 is arranged on the bottom of the leg 14 of the spring 12 , which is pushed laterally into the respective flanges 17 and 18 of the spring carrier 15 . In the recess 32. The clamping piece 30 is provided with a semi-cylindrical rib 31 which extends transversely to the load arm 1 and acts upwardly towards the end of the fastening bracket 29 against the positioning webs 22 and 23 .

The positioning tabs 22 , 23 are dimensioned such that they bear against the inner walls of the legs 4 and 5 of the profile 2 of the load arm 1 and are guided on these two inner walls. The free ends of the legs 14 of the spring 12 are provided with two further positioning lugs 20 and 21 which protrude beyond the spring carrier 15 in the longitudinal direction of the load arm 1 and which correspond to the positioning lugs 22 , 23 also at the profile 2 Guided on the inner surface of the legs 4,5. The spring 12 is thus guided in the transverse direction directly on the inner surface of the legs 4 , 5 of the profile 2 of the load arm 1 via the positioning lugs 20 , 21 , 22 , 23 , which means that it is independent of the spring carrier 15 . The loosening and displacement of the spring carrier 15 has no effect on this orientation between the spring 12 and the load arm 1 . For the free end of the leg 14 of the hairpin region of the spring 12, a loading element in the form of an eccentric pin 36 is provided, which is provided with two flattened eccentric surfaces 37 and 38, which are optionally contacted outrigger14. Depending on the radius of the eccentric surface 37 or 38, the spring 12 is preloaded.

A stop is assigned to the other leg 24 of the hairpin-shaped region of the spring 12 , which is designed in the form of a pin 35 arranged between the limbs 17 , 18 of the spring carrier 15 . This pin 35 limits the possible travel of the leg 24 of the spring 12 when the load arm 1 is disengaged from the lower roller 9 .

The positioning of the spring 12 in the operating state is thus determined by the positioning lugs 20 to 23 . It is therefore advantageous to also use these positioning tabs 20 to 23 during the injection molding or injection molding of the fastening frame 8 in order to position the spring 12 in the mold. Thereby, the positioning accuracy of the double pressure roller 6 relative to the load arm 1 can be further improved.

FIG. 3 shows a variant of the fastening frame 8 of the pressure roller stand. Identical components are provided with the same reference numerals, so that a further description can be omitted here. The fastening frame 8 is again cast directly onto the spring 12 by inserting at least partial regions 13 into the mold during the die-casting or injection molding of the fastening frame 8 . The fastening element 11 , which prevents the roller shaft 7 of the double pressure roller 6 from falling off, is integrated in the fastening frame 8 in this embodiment as a clip 26 . The advantage of this is that the step of separately manufacturing the bow spring 25 can be omitted. This configuration of the mounting bracket 8 can be realized particularly well when the mounting bracket 8 is largely made of plastic. In order that the plastic is not deformed when the pressure is transmitted from the spring 12 to the roller shaft 7 of the double pressure roller, it can be largely admixed with a strength-increasing material, such as fiberglass. This does not affect the processability during the injection molding process, but prevents the plastic from "creeping" very effectively.

Claims (6)

1. The pressure roller bracket used to fix the double pressure roller (6) in the draft mechanism, including a spring (12) for pressing the double pressure roller (6) and a roller shaft for the double pressure roller (6) (7) The fixed frame (8), wherein the fixed frame (8) is cast as a die-casting or injection molded part, characterized in that the fixed frame (8) is cast on the spring (12). 2. The pressure roller stand according to claim 1, characterized in that the fastening frame (8) is at least largely made of plastic. 3. Press roller support according to claim 1 or 2, characterized in that a fastening element (11) for the roller shaft (7) of the double pressure roller (6) is integrated in the fastening frame (8) . 4. A method for manufacturing a press roll holder for fixing a double press roll in a drafting mechanism, wherein the springs pressing the double press roll are connected to a mounting bracket for the twin press roll shaft, and wherein the The holder is cast as a die-cast or injection molded part in a mold, characterized in that the spring is inserted into the mold at least in a partial region and the holder is connected to the spring during the casting process. 5 . The method as claimed in claim 4 , characterized in that during the casting process, the spring is oriented relative to the mold with its positioning lugs provided in its active state. 6 . 6. The method as claimed in claim 4 or 5, characterized in that a fastening element for the roller shaft of the double pressure roller is integrated in the fastening frame during the pouring process.

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