JPH05117989A - Screen and its manufacture - Google Patents

Abstract

PURPOSE: To certainly fix sieve bars into a holding ring without welding by holding the sieve bars being parallel to each other in a holding bar stretching across the sieve bars in a specific state. CONSTITUTION: A sieve bar 3 is held to a notch 2' of the holding ring 1'. At least one of flanks 7 and 8 concerning a perpendicular direction of a sieve surface of the sieve bar is inclined to the perpendicular direction to generate a conical shape of 14 to 35 deg. between two flanks. Projections 36, 36' or notches of the sieve bar correspond to recesses or projections of the notch of the holding bar and snap coupling is formed when the sieve bar is inserted into the holding bar.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sieve basket and a method for producing the sieve basket.

Regarding the prior art, for example, German Patent Publication No. 3748746 (German Pat)
ent DE-OS3748746).
In this case, the sieving rod is mainly fixed to the notch of the supporting rod by conventional welding.

However, many disadvantages arise when using conventional welding techniques. First, there is a problem that reliable welding results cannot always be obtained. Secondly, the welds obtained have the disadvantage that they are easily prone to permanent fatigue failure. Third, some welding techniques, in most cases, such as crimping, create a bulge in the weld, or a sharp pointed weld edge, which is screened by a sieving basket. It can lead to the deposition of fibrous suspended particles that should be deposited, and this can be the source of severe, or even severe, blockage.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a novel sieve which obviates or reduces at least one of the above-mentioned prior art.

The present invention further aims at providing a novel process for the production of sieves.

It is an object of the present invention to provide a sieving basket which avoids welding and also allows a secure fastening of the sieving rod in the retaining ring.

[0007]

This object is achieved according to the invention by the features indicated in the characterizing part of claim 1. Preferred methods for the production of sieve baskets are specified by the method claims.

The sieve of the present invention comprises an arched or horizontal sieve and a sifter with sieving rods that are parallel to each other and are retained in retaining rods that extend parallel to one another and across the sieving rods. Such a sieve, in which case the sieving rod is in the vertical direction (V) of the sieving surface,
Has side faces, at least one of which is vertical (V)
In contrast, they are angled at an angle to produce a conical shape between the two sides of between 14 and 35 degrees, and these sides correspond to at least most of the notches of the retaining ring. In a sieve where the sides are corresponding and thus the first interspace of the sides of the sieve bar creates a sieve gap on the inlet side of the sieve surface, the protrusion or notch of the sieve bar is the recess of the notch of the retaining bar. Or corresponding to the projection and forming a snap connection together upon insertion of the sieving bar into the holding bar across the longitudinal direction of the holding bar.

The horizontal sieve of the present invention also has an arched shape having mutually parallel sieve bars held parallel to each other and within the notches of the retaining bars extending across the sieve bars. In a horizontal sieve, the protrusion or notch on the sieve bar corresponds to the recess or protrusion on the retaining bar notch, and snaps together when the sieve bar is inserted into the retaining rod across the length of the retaining rod. It is characterized by forming a bond.

The method of making a sieve according to the present invention comprises a coaxial retaining ring, which is axially spaced from one another, and a retaining ring, which is retained in a notch (2 ') having an open end,
A method of making a sieving basket comprising a sieve rod substantially parallel to the axis, wherein a) a particularly straight retaining rod, which is subsequently mounted radially inward of the retaining ring, is formed later from the retaining rod. A retaining ring at the radially inner edge of the retaining ring, the notch having an open edge, the notch having a surface inclined or parallel to the subsequent radial direction (V), −
The cross section of the notches thus conically converges radially inwardly to radially outwardly, and these notches have projections or rear projections following this flank, which projections or rear projections. The projections, together with the corresponding depressions or projections provided on the corresponding sides of the section of the sieve bar profile, are snapped into the retaining bar when the sieve bar is pushed across the length of the retaining bar. Securing the sieve bar, b) including pushing the sieve bar into the retaining bar, rolling the retaining bar into a complete ring, and c) welding each retaining bar or both ends of the retaining ring together. Is characterized by.

The connection between the individual sieve rods and the holding rods is
It is very advantageous to make the connection between the individual sieving rods and the holding rod as a snap connection, so that the sieving rod can be pressed into the holding rod across the longitudinal extension of the holding rod. This is expedient because the notched cross section of the holding rod need only be slightly larger than the cross section of the sieve rod profile.

Of course, the sieving rods use a relatively small profile section-about 15 to 20 mm ² -so that too many sieving rods form a sieving basket and the rounding of the retaining rods to the retaining ring. Only very small bending angles of 1/2 to 1 degree are necessary.

Therefore, the deformation of the notch of the holding rod is also very small, so that the difference in cross section between the sieve rod shape member and the notch of the holding rod is very small. This results in that it is very difficult to push the sieve bar in the longitudinal direction of the sieve bar. This is avoided by the snap connection method.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The sieve basket according to the invention is actually cylindrical in shape and the sieve rods 3 are arranged along the circumference of this axis parallel to the axis as shown in FIG. These sieving bars 3 are retained in the cutouts 2'of the retaining ring 1 '.

However, the sieving rod 3 is adapted to be initially inserted into the notch 2 of the straight retaining rod 1 substantially initially. It is provided with projections or notches in the cross section of the sieve bar profile, which engage corresponding recesses or projections in the notches of the holding bar. That is, the sieving bar 3 is carried out by pressing it into the notch of the holding bar across the longitudinal extension of the holding bar.

Basically, the sieving bar profile is formed substantially in the shape of a truncated cone, the thicker end of which is arranged radially inward of the sifter or retaining ring 1 '. There is. This cross-sectional shape can also be regarded as an elongated acute-angled triangle. In that case, the top of the triangle is cut,
The bottom surface is the smallest of the triangular surfaces.

The long sides of the two sides are offset with respect to the cutout in the retaining ring by a radius α of the sieve car drawn through the assumed cone or triangular top and by a specific angle α or β, Angles γ and δ for rod section
Only deviated. In practice, the angles γ and δ of the sieve rod profile are only slightly smaller than the corresponding angles α and β in the notches of the holding rod 1. That is, the cross section of the sieve rod material is slightly longer than the notch of the holding rod 1.

In the figure, the retaining rod is shown as modified into a retaining ring. Therefore, the angles α and β, or γ and σ are substantially the same. In this state, the sieve bar profile cross section is clamped snugly in the notch of the retaining ring 1 '. When the sieve rod is snapped into this notch, the teeth of the holding rod between the notches are, of course, deformed, so any protrusions or depressions in the sieve rod or the notch of the holding rod should be Not so large because there is a very narrow sieving gap between 0.15 and 0.3 mm, which is located closely to each other and between them in a radial inward direction as is usually done. May be. Therefore, the thickness (or depth as shown) of the protrusions or depressions may be in the range of between approximately 0.2 and 0.5 mm.

Depending on the diameter of the finished sieve basket, on the circumference of the sieve basket cylinder there are about 400 to 1300 sieve rods with a large cross-sectional dimension in the longitudinal direction of the retaining rod of about 4.0 mm. In its lateral direction, that is to say in the radial direction V, the dimension is approximately 5 to 7 mm. The sieve rod profile is a pultrusion profile and the notch in the holding bar is preferably made automatically by laser beam cutting.

The holding rods are held parallel to each other in the device at intervals corresponding to the distance of the holding rings from each other, and then the sieve rods are pushed adjacent to each other simultaneously into the notches of all the holding rods. Be done. And, of course, if the sieve rod profiles and the notches are made very precisely in their dimensions, the sieve rods are pushed into their notches in the holding rod in their longitudinal direction. After that, a sieving mat, which is actually made of parallel holding rods and sieving rod profiles, is rolled into a cylindrical sieve basket by bending the holding rods, then
The ends of each holding rod are welded together.

The sieve basket thus produced has the advantage that the connection between the sieving bar and the retaining ring has no welds.

Preferably, radially inwardly, the retaining ring is connected by welding to the reinforcing ring, which is further welded to a bolt (38, see FIG. 1) parallel to the axis.

According to the figure, one sieve bar profile is used, which has a projection 36 on one side in the radially outer region, which projection corresponds to a corresponding recess in the notch of the holding bar. Engage with. It is also indicated by a dashed line at 36 'that two sieving bar projections can also be provided. The angles α and σ of the triangular side faces 7 and 8 are specified. FIG. 3 shows the associated cutout 2 in the holding rod 1.

According to FIG. 4, the projections of the sieve bar profile are also on both sides, in this case the angles σ and δ of their sides.
Is equal to the corresponding angle to the radius V of the triangular plane. In this case, the projections 27 and 28 actually form a bulge and are also a kind of legs in the form of sieve rods, whereby these sieve rod profiles can be retained by the retaining ring 1'or the retaining ring. Held in a rod. These protrusions hold the sieve bar profile during the entire manufacturing process from the insertion of the sieve rod into the holding rod to the finished and finished sieving basket.

In FIG. 4, a somewhat simpler shape of the sieve bar material is shown by a dashed line.

According to FIG. 5, the profile cross section of the sieve rod 22 likewise has triangular sides 39 and 40, and notches 41 or 42 on each side. That is, the sides of the radially outer portions 27 'and 28' are substantially coplanar with the sides 39 and 40 of the radially inner region. In practice, the notches 41 and 42 are formed in the basic triangular shape of the profile of the profile.

According to FIG. 6, the notch 41 "is only on one side in the bar and the notch 41" is engaged by the notch projection 41 'of the retaining ring. Such a shape is
It seems to be relatively convenient for the operation of manufacturing the sieve bar profile. Here, the projections 41 'do not exactly coincide with the notches 41 ", but they coincide exactly in the radially outer part, so that the sieve rod is in radial direction when bending the holding rod. Have been shown to be very accurately located in.

Basically, the notches in the retaining ring or retaining rod must be aligned with the corresponding profile section up to about 70%. Because sticking is
This is because it is not necessary to cover the entire possible clamping area. In particular, the cutouts in the retaining ring may be larger than corresponding to the sieve bar profile, especially radially outwardly, so that there is, for example, 0.2 to 0.4 m.
There may be a gap of m. This gap must also be kept as small as possible due to the risk of stress formation.
The possible gap between the sieving rod and the holding rod is, after bending, sealed with a liquid plastic (Loctite. This is also shown in Figure 6. Basically, the rod cross section is It can be said that the sum of the angles σ + δ of the basic shape may be between 14 degrees and 34 degrees.

FIG. 7 illustrates an arrangement in which the shape of the teeth 32 produced between the sides 5 "or 6" of the holding rod is particularly suitable for snap actuation. Because there is a relatively flexible place in the root of the only protrusion 29 of the sieve bar profile, there is only deformation of the tooth during snap insertion in the elastic region and there is no substantial plastic deformation of it. Is.

On the other hand, however, it is possible to leave wide "teeth" at the end of the holding rod, for example 10 mm thick, so that after the last sieve rod snap-in, all the sieve rods and the teeth between them are correct again. , It is pushed into a position without permanent deformation. After bending the retaining rods or rolling the sieving mat and welding the adjacent ends of the individual retaining rings, in practice, the sieve rods are kept in the correct position relative to each other.
As already mentioned, the strength of the overall sieve basket is enhanced by the retaining ring distributed over it.

All the embodiments according to FIGS. 4 to 7 are also suitable for forming a so-called horizontal sieve 123.
See FIG. 9, which can be done with a positive or also with a bent retaining rod.

In this case, the sieve rod is snapped into the recess of the holding rod. In this case, the cross section of the sieving bar need not be thinner than the cross section of the recess in the retaining bar. In the case of such a sieve, the cross-sectional dimensions of the cutouts in the holding rod should be about 2/100 to 2/100 mm smaller than the corresponding dimensions of the profile section of the sieve rod in the fastening area. Also, if not clamped, there may be a larger gap between the sieve rod and the notch in the retaining rod than the above. The cross section of the sieving bar in the case of horizontal sieving can thus be considerably larger than the abovementioned dimensions for a (cylindrical) sieving basket.

Thus, since the initially flat retaining bars 145 are bent (backward) to widen the cutouts therein, the sieve bars 144 can easily be snapped into the cutouts. This rearward bending is in the pure elastic range of the material of the holding rod and also in the plastic range to meet the requirements. After that, the holding rods are returned to their linear shape again (in some cases only by elastic restoring force). In addition, the bending back of the holding rod takes place under the action of external forces-on a round device-so that the sieve rod is clamped more firmly in the notch of the holding rod.

This effect naturally occurs when the straight holding bar is bent into the curved shape of the arch-shaped horizontal sieve shown in FIG. A lateral holding rod 146 is further provided there.

FIG. 8 shows a cutout 52 for a horizontal sieve having a bag-like cutout of the retaining rod 145 and a recess 52 in the outer region of the associated or corresponding sieve rod cross section. The shape convenient for the snap operation of the provided sieve rod 51 is shown. In this embodiment, as numerically indicated above, there is a very small cross section of the sieve rod profile, and therefore it is convenient to make an arched sieve for the dewatering of the fiber suspension. In order to facilitate the insertion of the sieve rod 51, the holding rod 145 at the depth of the holding rod cross section
Since the notch of is somewhat larger than the diameter (width) of the sieve bar to which it corresponds, a gap 53 is created there, in which case the diameter of the sieve bar cross section is gradually smaller than that of the bottom of the notch. It is decreasing toward The gap 53 does not always have to be provided.

[Brief description of drawings]

FIG. 1 shows a perspective view of a part of a sieve basket.

FIG. 2 shows a sieve bar in one part of the retaining ring.

FIG. 3 shows the holding bar in the holding ring before deformation of the holding bar.

FIG. 4 shows still another sieve rod shape.

FIG. 5 shows still another sieve rod shape.

FIG. 6 shows still another sieve rod shape.

FIG. 7 shows still another sieve rod shape.

FIG. 8 shows still another sieve rod shape.

FIG. 9 shows an arched horizontal sieve.

[Explanation of symbols]

(01), (1,145) Retaining rod (02), (1 ') Retaining ring (03), (2,2') Notch (04), (3,3 ', 22,26,51) Sieve Rods (05), (27 ', 28') Radial outer portions (projections) (06), (27, 28, 29, 36, 36 ') Projections (07), (5, 6; 5', 6) '; 5 ", 6"; 39,
40) Side surface (08), (123) Horizontal sieve (09), (144) Sieve rod (10), (146) Horizontal holding rod 1

Claims (15)

[Claims] 1. Retained in holding rods (1, 1 ', 145) extending parallel to one another and across the sieve rod,
Sieve bars parallel to each other (3, 3 '; 22, 26, 14
4) an arched or horizontal sieve and a sieve like a sifter having a sifter, wherein the sieving rod has a lateral surface (7, 7) with respect to the vertical direction (V) of the sieving surface.
8; 7 ', 8'), at least one of which results in a cone between 14 and 35 degrees between the two sides with respect to the vertical direction (V), They are inclined at an angle and on these sides at least most of the corresponding sides (5, 6;) of the cutouts (2) of the retaining ring (1 ′).
5 ', 6'; 5 ", 6") correspond, and thus the side faces (7, 7, of the sieve rod (3, 3 '; 22, 26, 144)
8; 7 ', 8'; 7 ", 8"), the protrusions of the sieving rods (3,3 ', 22,26) in the sieve making the sieving gap on the entrance side of the sieving surface by the initial mutual spacing. Or the notch corresponds to the recess or protrusion of the notch of the retaining rod (1,1 ') and forms a snap connection together upon insertion of the sieve rod into the retaining rod across the length of the retaining rod. A sieve characterized by that. 2. An arched or horizontal sieve having parallel sieving rods held parallel to each other and within a notch in a retaining rod extending across the sieving rod, the sieving rod ( 144) the projection or notch of the holding rod (1
45) Corresponding to the recesses or protrusions of the notch and characterized by forming a snap connection together across the longitudinal direction of the holding rod when the sieve rod is inserted into the holding rod. sieve. 3. The sides of the sieve bar, or the rear of the notch and the projection or notch of the retaining ring, with respect to the radius (V) of the profile of the sieve bar or the notch, and thus in the circumferential direction of the retaining ring, are at least 0. The sieve according to claim 1 or 2 having a depth of 0.2 mm. 4. The sieve according to claim 3, wherein the depth is 0.1 to 0.5 mm. 5. The projection or notch of the notch of the sieve rod or the retaining ring has substantially the same inclination angle with respect to the profile of the sieve rod or the radius (V) of the notch of the retaining ring, and the retaining ring. The sieve according to any one of claims 1 to 4, wherein the sieve has a cross section or a side surface similar to the cutout. 6. The side surfaces (7, 8) of the sieve rod (3).
A sieve according to any one of claims 1 to 5, which has on both sides a projection in one end region which serves for retention in the retaining ring and which forms a kind of enlarged leg. 7. A sieve rod (3, 3 ', (3'''), 2
2, 26, 51) surrounding the die material cross section of the sieve rod (3, 30) in the area of the retaining ring (1 ')
7. The clamped state of the sieve rod in the retaining ring of the finished sieve basket corresponds to at least 50% of the peripheral area of the notch (2 ') of the retaining ring, according to claim 1. Sieve described in. 8. The projections of the section of the profile of the sieving bar--with respect to the transverse direction of the radius (V)-in their radial direction or the cutouts of the sieving bar are of maximum depth in their radially outward region. Or the depth of the protrusions or cutouts in the profile of the sieve rod so that it retains its radial orientation during the process of clamping the sieve rod into the rod that later forms the retaining ring. The sieve according to any one of claims 1 to 7, the dimensions of which are defined in. 9. Mutual protrusions or depressions in the cross section of the sieve material, or depressions in the holding rod, or rear protrusions of the depressions in the holding rod, when inserted into the holding rod across the longitudinal direction of the holding rod. The sieve basket according to claim 8, wherein a snap connection is formed in the basket. 10. Sieve according to claim 2, characterized in that it comprises a bag-shaped cutout in the retaining rod (145) and a recess (52) in the outer region of the associated or corresponding sieve rod cross section. 11. A coaxial retaining ring (1 '), axially spaced from one another, and retained in a notch (2') with an open end, substantially axially. A method of making a sieving car comprising parallel sieve rods (3,3 ', 3 ") comprising: a) a particularly straight retaining rod which is subsequently mounted radially inward of the retaining ring (1'). , Later provided with open-ended notches (2) at the radially inner edge of the retaining ring formed from the retaining rod (1), these notches being provided in a rearward radial direction (V). With respect to one another, the surfaces of the cutouts are conically converging from radially inward to radially outwardly, and these notches follow this side. Has a protrusion or a rear protrusion,
These projections or rear projections correspond to the corresponding depressions (41, 42; 41 ') or projections (36, 3) provided on the corresponding sides of the section of the sieve bar profile.
6 ', 27, 28), the sieve rod is fixed in the holding rod in the form of a snap connection when the sieve rod is pushed across the longitudinal direction of the holding rod (1), and b) the sieve rod ( 3 ', 3 ";22; 26) after pressing, the retaining rods are rolled into a complete ring, and c) the ends of each retaining rod or retaining ring (1') are welded together. A method characterized by. 12. The method for producing a sieve according to claim 11, wherein the notch is tapered from the inside to the outside of the retaining ring in a conical shape. 13. The notch on the retaining rod has projections or cut outs that engage on the sieve rod when a snap connection is made. Method of making a sieve. 14. The method according to claim 10, wherein the notch making in the holding rod is performed by laser beam cutting. 15. The method according to claim 11, wherein the holding rod is bent before the insertion of the sieve rod, so that the notch in the holding rod is widened and thus snapping the sieve rod is facilitated. Manufacturing method of sieving.