EP2151275A1 - Stirrer made from a metal rod for use in a drive machine, method for producing same and bending machine for carrying out production method - Google Patents

Abstract

The stirrer (1) has a shaft (3) forming a rotation axis and a stirring head (2) attached at an end region of the shaft, where the stirrer consists of a metallic rod. The head comprises a circular ring that is designed as a protective ring (4) with a cross bar, which is centrally connected with a shaft end perpendicular to a protective ring plane. The head comprises two spiral parts (6a, 6b), which are connected with the protective ring at a ring sided end and connected with the shaft at a shaft sided end. Independent claims are also included for the following: (1) a method for manufacturing a stirrer (2) a bending machine for manufacturing a stirrer.

Description

The invention relates to a stirrer made of a metal rod for use in a drive machine, and a production method for such a stirrer and a bending machine for producing such a stirrer and / or for carrying out the manufacturing method.

Stirrers made of a metal rod for use in a prime mover are well known in many embodiments. Such stirrers consist of a shaft forming the axis of rotation and a stirring basket attached thereto in an end region. For different mixing tasks appropriately adapted stirrers of different sizes and with different Rührkorbausführungen are well known. Such stirring baskets may comprise protective rings, impellers, stirring helix of flat material or round wires with different angles of incidence and different number of turns and are regularly made of metal material or in combination with other materials.

For an effective stirring result relatively complicated Rührkorbgeometrien are known in particular in helical parts made of flat materials with curved bent angles of attack, which is the production of Rührkörbe make it complicated and expensive. In particular, stirring baskets are usually made of several individual parts, which must be laboriously joined together and connected.

Such stirrers are used both in the commercial craft sector as well as in the private "do it your self" area and are therefore usually high-volume products, which are subject to high price pressure.

The object of the invention is therefore to develop a generic stirrer so that it can be produced inexpensively, especially in an automated mass production. Another object of the invention is to propose a suitable manufacturing method and a bending machine for carrying out the method.

The object is achieved in terms of the stirrer with the features of claim 1.

According to claim 1, the stirring basket on a circular ring as a guard ring with a transverse web, wherein the transverse web is connected centrally with a shaft end perpendicular to the guard ring level. In addition, the stirring basket further comprises two helically curved helical parts, which are connected opposite each with an annular end to the guard ring and with the other shaft-side end to the shaft.

Such a stirring basket consists of only a few, relatively simple to design parts and is ideal for automated low-cost production, the two helically bent coil parts ensure a good stirring function for conventional stirring and mixing tasks.

A good stirring function of the stirrer in conjunction with the possibility of automated production results when according to claim 2, the bending of the Helical each flat with small angles at the ring end begins and is performed with continuously steeper bending to the shank end, said determined by the opposite helix parts diameter of the mixing bowl in a ring-side lower Rührkorbteilbereich corresponds to the guard ring diameter. Subsequent to this Rührkorbteilbereich, which may extend approximately to the middle longitudinal extent of the mixing bowl, the Rührkorbdurchmesser decreases upward to the shaft, where the coil parts are connected thereto.

According to claim 3, a quarter-circle helix of the helical parts is suitable and sufficient for a good stirring result with simple automated production. In addition, according to claim 4, the ratio of the guard ring diameter to Rührkorblänge in a range of 1 to 1 to 4, preferably from about 1 to 1.5.

In principle, the stirrers claimed above can be made at least partially from a round wire material. In a preferred embodiment according to claim 5, however, the guard ring and / or the transverse web and / or the helical parts are made of a flat metal strip, wherein the flat sides of the guard ring and the crosspiece lie in the guard ring plane. The flat sides of the flat-band helical parts are also at the ring-side end approximately in the guard ring level and from there proceeding in continuously, following the desired spiral bend bent so far that the flat sides then run at the shank end approximately parallel to the shaft. Thus, on the one hand, a very stable effective protection ring is obtained and obtained by the employment of flat ribbon helical parts with respect to the stirring rotation an effective mixing result.

In an advantageous development according to claim 6, the guard ring, the cross bar and the helical parts, that is, the entire mixing bowl are integrally bent from a linkage section, wherein here preferably as a linkage section a metal flat band section is used. In order to enable automated production of such a one-piece stirring basket, the crosspiece forms a straight longitudinal center piece of the linkage section. Each starting from a transverse web end a semicircular arc is bent to form the guard ring, wherein the respective free end of the sheet rests on the opposite transverse web end and connected there, preferably spot-welded. Starting from there, the helical parts are bent and brought together with their shaft-side ends to a distance corresponding to the shaft diameter. The shaft is then connected as a second component to the transverse web and the shaft-side helical part ends, preferably welded. The claimed here geometry of a one-piece mixing bowl is particularly suitable for low-cost mass production with an automated manufacturing process and a bending machine, as will be explained in more detail below.

• In einem ersten Verfahrensschritt zur Herstellung des Rührkorbs wird von einem gerade gerichteten Metallband ein Gestänge-Abschnitt abgelängt mit einer Gesamtlänge entsprechend der Länge des Querstegs, etwa der 1,5-fachen Länge des Schutzringumfangs und der zweifachen Länge eines Wendelteils.
• In einem zweiten Verfahrensschritt wird ein Zwischenfertigungsteil hergestellt, in dem die gegenüberliegenden Enden des Gestänge-Abschnitts jeweils zu einem Viertelkreisbogen in der Länge eines Wendelteils abgebogen werden mit einem Radius größer als der Schutzringradius. Weiter wird der zwischen den abgebogenen Viertelkreisbögen liegende gerade Bereich unter Beibehaltung des geraden Querstegs schneckenförmig durch etwa eine ¾-Drehung etwa in einer Biegeebene zum Schutzring mit tangential abstehenden Viertelkreisbögen gebogen dergestalt, dass der Quersteg in dieser Biegeebene den beiden Viertelkreisbögen gegenüberliegt. Grundsätzlich könnte in diesem zweiten Verfahrensschritt auch die schneckenförmige Schutzringbiegung zuerst durchgeführt werden und anschließend die Viertelkreisbögen abgebogen werden.
• In einem dritten Verfahrensschritt wird ausgehend vom Zwischenfertigungsteil dann der fertige Rührkorb hergestellt, indem die schutzringseitigen Enden der Viertelkreisbögen am Schutzring fixiert werden und die freien Enden der Viertelkreisbögen erfasst und durch eine Zugbewegung senkrecht aus der vorstehenden Biegeebene bei einer gleichzeitigen Wendelverdrehung mit vorzugsweise einer Viertelkreiswendelung zu den Wendelteilen gebogen werden.

The object of the invention with regard to the production method is achieved with the features of claim 7, wherein the mixing bowl is produced in one piece and automatically in three process steps:

• In a first method step for producing the stirring basket, a rod section is cut from a straight metal strip with a total length corresponding to the length of the transverse web, approximately 1.5 times the length of the guard ring and twice the length of a helical part.
• In a second method step, an intermediate production part is produced, in which the opposite ends of the linkage section are bent in each case to a quarter circle arc in the length of a helical part with a radius greater than the guard ring radius. Further, the straight area lying between the bent quadrant arches becomes snail-shaped while maintaining the straight crossbar by about ¾ rotation curved in a bending plane to the guard ring with tangentially protruding quarter-circle arches in such a way that the crossbar is opposite to the two quadrant arcs in this bending plane. In principle, in this second method step, the spiral-shaped protective ring bending could be carried out first and then the quarter-circle arcs are bent.
• In a third step, starting from the intermediate production part of the finished stirring basket is prepared by the guard ring side ends of the quadrant arcs are fixed to the guard ring and detects the free ends of the quadrant arcs and by a pulling motion perpendicular from the above bending plane with a simultaneous helical twist with preferably a quarter circle helix to the Be bent coil parts.

The above three process steps for producing a one-piece stirring basket are relatively simple, fast, inexpensive and dimensionally feasible with a bending machine. In particular, this method is excellently suited for the preferred stirrer design with a flat metal strip, in which case the flat sides lie in the bending plane during the intermediate production step.

According to claim 9, it is then only necessary in a fourth method step to use the shaft, preferably as a hexagonal rod in the mixing basket and end to connect to the crossbar and with the helical parts, preferably to weld. Furthermore, two additional welding spots are attached at the beginning of the helix. This fourth process step can also be easily automated via a feed device for the shafts and a welding machine, so that the entire stirrer production can be carried out fully automatically.

Further claim 10 claims a bending machine for producing a stirrer according to the preceding claims and / or for carrying out one of the above manufacturing methods.

Reference to a drawing, the invention will be further explained.

Fig. 1

eine Ansicht eines Rührers von unten;

Fig. 2

eine Seitenansicht des Rührers nach Fig. 1;

Fig. 3

eine Draufsicht auf den Rührer nach den Fig. 1 und 2;

Fig. 4

eine Seitenansicht auf eine Vertikalebene einer Biegemaschine mit mehreren Arbeitspositionen;

Fig. 5

eine Draufsicht auf die Biegemaschine nach Fig. 4 mit zwei Ausschnitten im Bereich von zwei Arbeitspositionen;

Fig. 6

eine vergrößerte Draufsicht auf ein Zwischenfertigungsteil und

Fig. 7

eine Seitenansicht des Zwischenfertigungsteils nach Fig. 6.

Show it:

Fig. 1

a view of a stirrer from below;

Fig. 2

a side view of the stirrer after Fig. 1 ;

Fig. 3

a plan view of the stirrer after the Fig. 1 and 2 ;

Fig. 4

a side view of a vertical plane of a bending machine with multiple working positions;

Fig. 5

a plan view of the bending machine according to Fig. 4 with two cutouts in the range of two working positions;

Fig. 6

an enlarged plan view of an intermediate production part and

Fig. 7

a side view of the intermediate production part after Fig. 6 ,

In the Fig. 1 to 3 Fig. 3 is a bottom view, side view and top view of a stirrer 1 with a stirring basket 2 and a shaft 3 forming the axis of rotation and shown cut off at the top, which is insertable into a rotary drive machine (not shown).

The stirring basket 2 consists of a guard ring 4 with a transverse web 5, with which one end of the shaft 3 is connected centrally by welding. Starting from the guard ring 4, the stirring basket 2 also has two opposite helical parts 6a, 6b, which are welded with their upper ends to the shaft 3.

The Rühkorb 2 with its guard ring 4, the cross bar 5 and the coil parts 6a, 6b is made in one piece from a flat metal strip, wherein the bending of the coil parts 6a, 6b flat starts with a small angle at the lower end of the ring and continuously steeper leading to the shank end is. Here, the determined by the opposite helical parts 6a, 6b Rührkorbdurchmesser in the lower Rührkorbteilbereich corresponds to about the average height of the guard ring diameter, which then decreases in size towards the upper 3. The helical parts 6a, 6b each have approximately a quarter circle helix and the diameter of the guard ring 4 is approximately 1 to 1.5 in relation to the length of the mixing head 2. The shaft 3 is in Fig. 2 only in the region of the mixing bowl 2 and in fact has a length which corresponds approximately to 3 times the Rührkolblänge.

The flat sides of the metal flat strip are in the guard ring 4 and the cross bar 5 in the guard ring level. The flat sides of the flat band coil parts 6a, 6b are located at the ring-side end approximately in the guard ring plane and are bent from there, starting with about a quarter circle helical bend continuously to the shank end. The shaft 3 is designed as a hexagonal rod.

• In Fig. 4 ist schematisch eine Seitenansicht auf eine Vertikalebene einer Biegemaschine 7 mit im Wesentlichen zwei Arbeitspositionen 8, 9 gezeigt, wobei in Fig. 5 in Ausschnitten eine Draufsicht auf diese Arbeitspositionen 8, 9 dargestellt ist.

Based on Fig. 4 to 7, the automated production of the stirrer 1 is the Fig. 1 to 3 explained in more detail:

• In Fig. 4 is shown schematically a side view of a vertical plane of a bending machine 7 with substantially two working positions 8, 9, wherein in Fig. 5 in sections, a plan view of these working positions 8, 9 is shown.

From the right side in Fig. 4 is fed by a (not shown) ribbon roll a straightened flat metal strip 10, measured in its length and cut to length by a shear punch 11. Thus, a straight aligned flat band section 12 of the working position 8 is supplied with mutually equal length, as shown in dashed lines. The length of the flat strip section 12 corresponds to the sum of the lengths of the transverse web 5 approximately 1.5 times the length of the guard ring circumference and twice the length of a helical part 6a, 6b. The flat band portion 12 is inserted into the bending machine 7 so that the flat side in the view of Fig. 4 you can see.

Subsequently, an intermediate production part 13 is produced in a second process step, as already in the finished state in the 4 and 5 at work position 8 and enlarged in the Fig. 6 and FIG. 7 is shown. For this purpose, the opposite end portions of the flat band portion 12 are bent with rollers 14a, 14b at corresponding mold parts 15a, 15b to Viertelkreisbögen 16a, 16b in different directions and in the length of each helical part 6a, 6b with a radius greater than the guard ring radius of the still to be produced guard ring 4th This results in an elongate component having a straight intermediate region and two bent quadrant arcs, which are released again for further processing by retraction of the rollers 14a, 14b.

Subsequently, the straight region of the flat strip section 12 lying between the quadrant arcs 16a, 16b is maintained helically, while maintaining the straight transverse web, by approximately a ¾ turn approximately in one Bending plane to the guard ring 4 and the finished intermediate production part 13 bent. As from the enlarged representations of Fig. 6 7, the quarter-circle arches 16a, 16b tangentially protrude from the guard ring 4, wherein the transverse web 5 in the bending plane opposite the two quadrant arcs 16a, 16b or are the quarter circle arches 16a, 16b both in front of the crossbar.

After the intermediate production part 13 has been produced in the bending machine 7 at the working position 8, this is supplied to the working position 9 by a transport unit (not shown), where it is placed in the working position 9 Fig. 4 fixed position shown. Subsequently, the ends of the quarter circle arcs 16a, 16b are gripped by holders 17a, 17b (shown in dashed lines). By a pulling movement of the guard ring plane in conjunction with a simultaneous merger of the ends of the quarter circular arcs 16a, 16b and a helical rotation to a quarter circle helix are fully automatically the helical parts 6a, 6b bent, whereby then the at the working position 8 in Fig. 5 shown finished mixing basket 2 is formed. Subsequently, the mixing bowl 2 is removed from the bending machine 7 and fully automatically equipped with the shaft 3 and welded.

Claims (10)

Stirrer made of a metal rod for use in a drive machine with a shaft (3) forming the axis of rotation and an agitator basket (2) attached thereto in an end region, characterized in that the agitator basket (2) is a circular ring as guard ring (4) with a transverse web (Fig. 5), and the transverse web (5) is connected centrally with a shaft end perpendicular to the guard ring plane, and that the stirring basket (2) further comprises two helically curved helical parts (6a, 6b) which are opposite each with an annular end with the guard ring (5). 4) and connected to the other shaft end with the shaft (3). Stirrer according to claim 1, characterized in that the bending of the helical parts (6a, 6b) each starts flat at a small angle at the ring end and is guided with continuously steeper bending up to the shank end, such that the through the opposite helical parts (6a , 6b) corresponds to certain diameters of the mixing bowl (2) in a ring-side lower Rührkorbbereich the guard ring diameter and the diameter then decreases in this Rührkorbteilbereich upwards to the shaft (3) out. Stirrer according to claim 2, characterized in that the helical parts (6a, 6b) each have a quarter circle helix. Stirrer according to one of claims 1 to 3, characterized in that the ratio of the guard ring diameter to Rührkorblänge in a range of 1 to 1 to 4, preferably from 1 to 1.5. Stirrer according to one of claims 1 to 4, characterized in that the protective ring (4) and / or the transverse web (5) and / or the helical parts (6a, 6b) are made of a flat metal strip (10), wherein optionally the flat sides of the guard ring (4) and the transverse web (5) lie in the guard ring plane and the flat sides of the flat-band helical parts (6a, 6b) lie at the ring-side end approximately in the guard ring plane and from there starting the flat-band helical parts (6a, 6b) in the continuously bent bend desired following are so far that the flat sides at the shank end extend approximately parallel to the shaft. Stirrer according to one of claims 1 to 5, characterized in that the guard ring (4), the transverse web (5) and the helical parts (6a, 6b) are integrally bent from a linkage section, preferably a flat metal strip section (12), in such a way that the transverse web (5) forms a straight longitudinal center piece of the linkage section, that in opposite directions a semicircular arc for forming the guard ring (4) is bent starting from a cross web end, the respective free end of the arch resting on the opposite transverse web end and connected there, is preferably spot welded and that from there starting the helical parts (6a, 6b) are bent and merged with their shank ends to a distance corresponding to the shaft diameter, and that the shaft (3) as a second component with the crossbar (5) and the shaft side Spiral dividing connected, preferably welded. A method for producing a stirrer (1) according to one of claims 1 to 6, characterized in that for producing a stirring basket (2) of the stirrer (1) in a first method step from a straight metal strip, a linkage section (12) with a Total length is cut to length corresponding to the length of the transverse web (5) 1.5 times the length of the guard ring circumference and 2 times the length of a helical part (6a, 6b),
in a second method step, an intermediate production part (13) is produced by bending the opposite end regions of the linkage section (12) to a quarter circle arc (16a, 16b) in the length of a helical part (6a, 6b) with a radius greater than the Schutzringradius, and further by the lying between the bent quarter circular arcs (16a, 16b) straight area while maintaining the straight crosspiece (5) helical by a ¾ rotation approximately in a bending plane to the guard ring (4) with tangentially protruding quarter circle arcs (16a, 16b ) is bent such that the transverse web (5) in this bending plane the two quadrant arcs (16a, 16b) is opposite, and
that in a third method step, starting from the intermediate production part (13), the stirring basket (2) is produced by fixing the ring ends of the quarter circle arcs (16a, 16b) to the guard ring (4) and grasping the free ends of the quadrant arcs (16a, 16b) and be bent by a pulling movement perpendicularly from the above bending plane at a simultaneous merge and helical twist with preferably a quarter circle helix to the helical parts (6a, 6b). A method for producing a stirrer according to claim 7, characterized in that the linkage section is a metal flat strip section (12), the flat sides of the intermediate production part (13) lie in the bending plane. A method for producing a stirrer according to claim 7 or 8, characterized in that in a fourth step, the shaft (3) preferably used as a hexagonal rod in the stirrer basket (2) and end connected to the crossbar (5) and with the helical part ends, preferably welded and two additional welding points are each attached to the beginning of the coil. Bending machine (7) for producing a stirrer (1) according to claims 1 to 6 and / or for carrying out a method for producing a stirrer (1) according to claims 7 to 9.

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