JPH0368805B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a mixing tool for a concrete mixer as set forth in the first aspect of claim 1.

This type of mixing device has a patent of the Federal Republic of Germany.
No. 2,311,579, and at the heart of this patent is the issue of easy adjustment of the wear plate.

Owing to the fact that the wormband or the supporting helical surface of which this wormband is made up, and therefore also the wear plates, are oriented perpendicularly to the inner wall surface of the mixing tank drum, these wear plates have a During the upward movement, it is exposed to strong wear due to the mixed material flow. Furthermore, it has been demonstrated that the fixing holes in the wear plate also accelerate wear. This is because these holes create grooves in the surface of each wear plate.

The essence of the problem underlying the invention is to improve the above-mentioned mixer so as to prevent the wear plates from wearing out and to make them last longer.

The above object is achieved by a configuration having the features described in claim 1.

The figures showing examples will be described in detail.

Figure 1 shows the entire concrete mixer. 2
Between the two machine frames there is a drum-shaped, horizontally supported mixing tank 11.

Mixing tank wall portions 12 and 13 on two opposing end surfaces
A horizontal mixing shaft 14 is supported on each machine frame. This mixing shaft has mixing arms 15 to 18 extending radially close to the mixing tank wall, and at the ends of these mixing arms two worm bands with the same pitch and mutually forming a helical surface are attached to a supporting spiral 25. , 26 are formed and fixed, these support spirals starting from one of the two end-side mixing vessel walls 12, 13 in each case and extending along the inner wall of the vessel in the longitudinal direction of the mixing layer 11. and extend beyond the center of the mixing tank to a distance from the respective end mixing tank wall forming a turning chamber for the mixed material.

The supporting helical surfaces 25, 26 are each fixed to a rotating mixing arm in the area of the end mixing tank walls 12 and 13. Furthermore, two mixing arms 15, 16, 17, 18 are likewise fastened to the support helix. During operation, the mixed material is moved alternately on the convection principle from one end-side mixing tank wall 12, 13 to the other with a horizontal feeding effect in the region of the tank wall, and is then mixed with the remaining mixed material in a circulation process. mixed. Replacement of mixed materials is rapid and effective regardless of type.

The supporting helical surfaces 25 and 26 have receiving compartments 27 directly adjacent to each other on the surface on which the wear plate is mounted.
has. In this receiving compartment, wear plates 28 made of a particularly hard and wear-resistant alloy can be fixed, which are arranged next to each other without gaps.

Inside the receiving compartment 27 there are a flat surface 29 formed by mutually bending, a protruding guide bar 30 and an elongated hole 31. Federal Republic of Germany Patent No. 2311579
In this example, the rear surface of the wear plate is adapted to these guide and fixing members 30, 31. In that case, wear plate 2
8 is fixed at the provided position with correct spacing up to the wall of the mixing tank.

The surfaces of the wear plates 28 that are arranged adjacent to each other on one helical surface are continuously transferred to each other to form a uniformly curved helical surface, and this helical surface is formed on the mixing tank wall on the end side. 12, 13 and continues on the mixing arm there to the bearing position of the mixing shaft 14.

The present invention improves upon this known and still generally trusted arrangement as follows. That is, wear plate 2
8 does not lie flat on the flat surface of the support spirals 25, 26 or on the shaft 29, but is arranged obliquely so that the edge facing the mixing tank drum is in front with respect to the direction of rotation of the mixing shaft 14. Ru. In this way, the flow behavior of the mixed stream flowing away along the surface of the wear plate 28 is strongly influenced, so that the service life of the wear plate is significantly extended.

Said inclined position is such that the wear plate 28 constructed according to the invention rests with its edge directed towards the interior of the mixing vessel on the support helix 25, 26 and overlaps the guide rung 30 of this support helix, so that the wear plate 28 lower side,
This is achieved by providing two bearings 40 in the rear region. The wear plate 28 is thus inclined relative to the plane defined by the surface of the support helix.

In the development of this wear plate arrangement, which is advantageous with respect to wear, the free space 41 obtained by the inclined position between the back side of the wear plate and the surface of the support helix is
The wear plate 28 and the support helix 2 are connected to each other via a support base connected to the support base 8 and a fixing member that engages with the support base and enters the elongated hole 31 in the support helix 25, 26.
It is used to create a releasable connection between 5 and 26. In this way, the holes passing through the wear plate 28 as a whole are connected to the wear plate 28 at the edges and corners.
This prevents the formation of stains on the surface of the skin.

In the illustrated embodiment, the support is realized by providing a slit frustoconical projection 42 along the generatrix. This truncated cone is hollow and is provided in such a way that a screw head can be inserted through the opening in the generatrix, creating a space. On the free end face, a truncated cone is configured to provide a shoulder-like contact surface for the screw head. Moreover, the free end face of the truncated cone is beveled so that, if the inclined position of the wear plate 28 is as defined, said end face rests on the corresponding flat partial face 29 of the support helix 25, 26. be placed.

The wear plate 28 thus rests on the receiving compartment 27 via the front edge, the bearing 40 and the projection 42. As in the case of German Patent No. 2311579,
Wear plate 2 due to linear sliding on flat partial surface 29
8 best adjustment method is maintained.

FIG. 3 shows a wear plate 28 screwed onto the support spirals 25, 26 in a cross-section according to the invention. The tilt position is characterized and defined by the angle α. The illustrated bearings 40 are spaced far enough apart so that a screw 43 can be passed through as a fastening element. A truncated conical projection 42 is provided approximately at the center of the wear plate 28. This protrusion forms a slit toward this side from the side surface of the support portion 40. The free end surface of the protrusion 42 is the wear plate 2
It is cut diagonally to match the inclined position of 8, and that surface is on the support spiral. Furthermore, said end face is tapered in the form of a collar and is configured to provide a resting shoulder for the screw head.

Said screw is designated 43. When the wear plate 28 is loosened, this screw passes through a truncated conical projection 42 between the bearings 40, with a threaded portion projecting from the free end face of the projection 42. The head of the screw abuts the inside of the collar-like constriction.

The wear plate 28 rests on corresponding portions of the support helices 25, 26 by loosely threaded screws 43. The threaded portion of the screw 43 is passed through the corresponding elongated hole 31, and is fixed from the back side with a screw nut. The individual wear plates 28 are clamped via their bearings 40 and the end faces of the frustoconical projections 42 by the corresponding partial surfaces 29 of the receiving compartments 27. By releasing the screw connection, each wear plate 28 can be slid and fixed again.

In line with the inventive configuration of the threaded connection between the wear plate and the support spiral, a smooth surface is possible everywhere for the surface of the mixer that is exposed to the mixing flow without interruptions by threaded holes. The arrangement according to the invention significantly increases the life of expensive wear plates, since the oblique positioning of these wear plates also has an effect in reducing wear and tear on them.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of the entire mixing tool, FIG. 2 is a view showing a supporting spiral surface of the mixing tool having a wear plate configured according to the present invention, and FIG. 3 is a cross-sectional view of the supporting spiral surface and the wear plate. be. Symbols in the figure 25, 26...Support spiral surface, 28...
wear plate.

Claims (1)

[Claims] 1. A drum-shaped mixing tank, in which at least one mixing shaft is supported horizontally, the mixing shaft being twisted in opposite directions, It has two worm bands having helical surfaces of equal pitch perpendicular to the inner wall surface of the tank, each of these worm bands being configured as an integrally formed support helical surface,
These support helical surfaces are divided into flat partial surfaces formed by mutually bending, in order to accommodate the wear plates adjacent to each other without any gaps, and these partial surfaces serve as storage compartments for the wear plates. In a mixing tool for a concrete mixer, the wear plate 28 is connected to the support helical surface 2 in a mixing tool for a concrete mixer, in which the wear plate is movably connected in non-frictional engagement with the wormband on its rear side.
arranged at an inclined position relative to 5, 26;
In this case, the edge of the wear plate facing the mixing shaft rests on the supporting helical surfaces 25, 26 and has a bearing 40 corresponding to the inclination in the area of the edge of the wear plate facing the inner wall of the mixing tank. and a support base for accommodating and holding a fixing member 43 for connecting the wear plate 28 and the support spiral surfaces 25, 26 on the back surface of the wear plate. 2. The structure of the support base is as follows: a. A truncated cone-shaped projection 42 is provided approximately at the center of the back surface of the wear plate 28, b. The truncated cone is hollow to fit the fixing member, and c. The end face is shaved obliquely to match the inclination position of the wear plate 28, d) The end face of the truncated cone is tapered into a collar shape toward the cone axis, e) The generatrix of the truncated cone corresponds to the inclination position of the wear plate 28. A slit-like cut is made from the open side surface provided by the fixing member to the end face in accordance with the fixing member, and as a result, a pocket-shaped cutout for introducing the fixing member having a shoulder for supporting the fixing member 43 oppositely is formed. The mixing tool according to claim 1, wherein the mixing tool is made to be able to mix. 3 The wear plate 28 is attached to the support portion 40 and the truncated conical projection 4
3. Mixing device according to claim 1, configured together with 2 as an integral cast pair.