EP2151275B1 - Stirrer made from a metal rod for use in a drive machine, and method for producing same - Google Patents

Description

The invention relates to a stirrer made of a metal rod for use in a drive machine according to the preamble of claim 1 and a manufacturing method for a stirrer according to the preamble of claim 7.

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 are relatively complicated Rührkorbgeometrien especially in helical parts made of flat materials with curved bent angles of attack, which make the production of the Rührkörbe 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.

An example of such a stirrer is that in the DE 92 02 607 U1 revealed stirrer dar. Specifically shows the DE 92 02 607 U1 a one-piece stirred basket bent from a round iron bar with a crosspiece as a straight central piece. This transverse web is welded to the front side of the handle basket end shaft end with a welding point and lies in a radial plane. Each transverse web end is bent in each case in the same direction of rotation to a semicircular arc, whereby a total of a frontal protection ring is formed. Following the semicircular arches, helical helix parts are bent, to which connecting webs extend towards the shank. The connecting webs are also bent obliquely to the drive end shaft end up and connected to the shaft via welding points.

From the catalog of the company Protool entitled " Stirrers 2006 from Protool Germany ", found on the Internet on 14 January 2009 at" http: //www,produkte24.com/y/protool-deutschland-1056/ruehrwerke-2006-2486.html "(XP 002510535) helical stirrers are known which have a similar, multi-piece construction.

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. A further object of the invention is to propose a production method by means of which a stirrer can be produced in a simple and inexpensive manner in terms of production technology.

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

Such a stirring basket ensures an excellent stirring function in conjunction with conventional stirring and mixing tasks and is also easy to manufacture without major component complexity. In particular, such a stirrer is ideal for automated low-cost production, which will be explained in more detail below.

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 parts each starts flat with small angles at the ring end and is performed with continuously steeper bending up to the shank end, said by opposite helical parts certain 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 a preferred embodiment according to claim 5, moreover, the flat sides of the flat band helical parts are also approximately in the guard ring level at the ring end and are continuous from there, following the desired spiral bend bent so far that the flat sides then extend 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 order to enable automated production of such a one-piece agitator basket, the crosspiece according to claim 6 forms a straight Langsmittetstück 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 a budget Mass production with an automated manufacturing process and a bending machine, as will be explained in more detail below.

The object of the invention is achieved in terms of the manufacturing method with the features of claim 7, wherein the mixing bowl is manufactured 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, about 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 region lying between the bent quadrant arcs is helically bent while maintaining the straight crosspiece by approximately ¾ rotation approximately in a bending plane to the guard ring with tangentially protruding quadrant arcs such that the crosspiece faces 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 process step, starting from the intermediate production part then the finished stirring basket is prepared by the guard ring side ends of the quarter circle arches are fixed to the guard ring and detects the free ends of the quarter circle arcs and by a pulling movement perpendicular from the above bending plane with a simultaneous spiral twist with preferably a Viertelkreiswendelung be bent to the 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 principle, such a stirrer can be made at least partially from a round wire material. However, this method is particularly suitable for the preferred stirrer design with a flat metal strip, wherein then lie in the intermediate production part of the flat sides in the bending plane.

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.

With reference to the drawings, 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 mixing bowl 2 with its guard ring 4, the crossbar 5 and the helical parts 6a, 6b is made in one piece from a flat metal strip, wherein the bending of the helical parts 6a, 6b starts flat 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 in relation to the length of the mixing head 2 about 1 to 1.5. 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 up to the shank end. The shaft 3 is designed as a hexagonal rod.

Based on Fig. 4 to 7 is the automated production of the stirrer 1 of 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 6 and 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 bent in the form of a worm by approximately a ¾ turn approximately in a bending plane towards the guard ring 4 and the finished intermediate production part 13 while maintaining the straight crosspiece. As from the enlarged representations of 6 and 7 it can be seen standing thereby the quadrant arches 16a, 16b tangentially from the guard ring 4, wherein the crosspiece 5 in the bending plane the two quadrant arcs 16a, 16b is opposite or are the Viertelkreisbögen 16a, 16b here both in the viewing direction in front of the crossbar. 5

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 level 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, the helical parts 6a, 6b are fully automatically bent, which then 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 (9)

1. Stirrer made from a metal rod for use in a drive machine, having a shaft (3) forming the axis of rotation and having a stirring cage (2) installed thereon in an end region, wherein the stirring cage (2) has a circular ring as a protective ring (4) with a cross web (5), and wherein the cross web (5) is linked coaxially to an end of the shaft perpendicular to the protective ring level, and wherein the stirring cage (2) has two further helically-curved helix parts (6a, 6b), which are each linked oppositely with a ring-side end to the protective ring (4) and with the other shaft-side end to the shaft (3), characterised in that the stirring cage (2) that has the protective ring (4), the cross web (5) and the helix parts (6a, 6b) is curved in one piece from a metal ribbon cable (10), wherein the flat sides of the protective ring (4) and the cross web (5) are located in the protective ring level.
2. Stirrer according to claim 1, characterised in that the bending of the helix parts (6a, 6b) begins flat for each with a small angle at the ring-side end and continues with continuously increasingly steep bending up to the shaft-side end, in such a way that the diameter of the stirring cage (2) defined by the helix parts (6a, 6b) opposite corresponds to the diameter of the protective ring in a ring-side region underneath the stirring cage, and that the diameter decreases further up the shaft (3) adjacently to this stirring cage region.
3. Stirrer according to claim 2, characterised in that the helix parts (6a, 6b) each have a quarter arc.
4. Stirrer according to one of claims 1 to 3, characterised in that the ratio of the diameter of the protective ring to the stirring cage length is in a range from 1:1 to 1:4, preferably 1:1.5.
5. Stirrer according to one of claims 1 to 4, characterised in that, in addition, the flat sides of the ribbon cable helix parts (6a, 6b) are located on the ring-side end approximately in the protective ring level, and, based on this, the ribbon cable helix parts (6a, 6b) are subsequently bent continuously towards themselves for the desired helical bending in such a way that the flat sides on the shaft-side end run approximately parallel to the shaft.
6. Stirrer according to one of claims 1 to 5, characterised in that the cross web (5) forms a straight longitudinal middle piece of the rod section, in that a respective semi-circular arc is bent counter-rotatively to create the protective ring (4), based on a cross web end, wherein the respective free arc end rests on the opposite cross web end and is linked there, is preferably spot-welded, and in that, based on this, the helix parts (6a, 6b) are bent and merged together with their shaft-side ends up to a distance corresponding to the diameter of the shaft, and in that the shaft (3) is linked to the cross web (5) and the shaft-side helix parts as a second component, preferably welded.
7. Method for producing a stirrer (1) made from a metal rod for use in a drive machine, having a shaft (3) forming the axis of rotation and having a stirring cage (2) installed thereon in an end region, wherein the stirring cage (2) has a circular ring as a protective ring (4) with a cross web (5), and wherein the cross web (5) is linked coaxially to an end of the shaft perpendicular to the protective ring level, and wherein the stirring cage (2) has two further helically-curved helix parts (6a, 6b), which are each linked oppositely with a ring-side end to the protective ring (4) and with the other shaft-side end to the shaft (3), characterised in that, for the automatic production of the stirring cage (2) of the stirrer (1) using a bending machine (7) in a first method step from an equally level metal ribbon, a rod section (12) with an overall length corresponding to the length of the cross web (5) is cut into lengths, namely 1.5-times the length of the circumference of the protective ring, and 2-times the length of a helix part (6a, 6b),
   in that an interim production part (13) is produced in a second method step using the bending machine (7), wherein the opposite end regions of the rod section (12) are each bent to a quarter arc (16a, 16b) in the length of a helix part (6a, 6b), having a radius larger than the radius of the protective ring, and wherein the region lying directly between the bent quarter arcs (16a, 16b) is bent helically under retention of the straight cross webs (5) by a % turn approximately in a bending level of the protective ring (4) with tangentially-distant quarter arcs (16a, 16b) in such a way that the cross web (5) in this bending level is opposite to both the quarter arcs (16a, 16b), and
   in that, based on the interim production part (13), the stirring cage (2) is produced in a third method step using the bending machine (7), wherein the protective-ring-side ends of the quarter arcs (16a, 16b) are fixed in position to the protective ring (4), and in that the free ends of the quarter arcs (16a, 16b) are covered and bent perpendicularly from the bending level above by a pulling movement during a simultaneous merging and rotation of the helices towards the helix parts (6a, 6b).
8. Method for producing a stirrer according to claim 7, characterised in that the rod section is a metal ribbon cable section (12), the flat sides of which are located in the bending level for the interim production part (13).
9. Method for producing a stirrer according to claim 7 or 8, characterised in that the shaft (3) is preferably inserted into the stirring cage (2) as six-sided rod in a fourth method step and linked at its end to the cross web (5) and the helix parts, is preferably welded, and in that two additional welding spots are each installed at the start of the helix.

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