DE102019109984B3 - Cutting element and device for shredding materials - Google Patents

Abstract

The invention relates to a cutting element, in particular a knife, for a device for comminuting materials, the device having a plurality of cutting elements which can be moved towards one another and which engage in a comb-like manner in a first row and in a second row and with an upwardly widened one Angle arranged and mounted on a common bearing shaft, wherein cutting elements of the first row with cutting elements of the second row are arranged in a cutting area partially in contact with each other and the cutting elements of the first row are assigned a first eccentric drive shaft and the cutting elements of the second row are assigned a second eccentric drive shaft, so that the cutting elements carry out a cutting movement when the first eccentric shaft is driven and / or when the second eccentric shaft is driven, the cutting element having a bearing shaft receptacle on the bearing shaft side, which is opened on one side saving is formed so that shredded material, which is located in the bearing shaft receptacle, falls out downwards.

Description

The invention relates to a cutting element, in particular a knife, for a device for comminuting materials, the device having a plurality of cutting elements which can be moved towards one another and which engage in one another in a comb-like manner in a first row and in a second row and with an upwardly widened one Angled and are arranged on a common bearing shaft, the cutting elements of the first row with cutting elements of the second row being arranged in a cutting area partially in contact with each other and the cutting elements of the first row being assigned a first eccentric drive shaft and the cutting elements of the second row being assigned a second eccentric drive shaft, so that the cutting elements perform a cutting movement when the first eccentric shaft and / or the second eccentric drive shaft is driven, as well as a corresponding device for comminuting materials.

Devices for comminuting materials, such as shredders, very often have knives which intermesh in a comb-like manner. These knives are usually mounted on two bearing shafts and an eccentric drive is assigned to them, the eccentric drive imposing an eccentric path on a special cutting knife and a cutting movement being carried out through the interaction with the respective opposite cutting knives, which usually also have an eccentric drive. The knives can each form different positions due to the use of different eccentric shafts. If a large number of knives are arranged next to one another and opposite one another and interlocking in a comb-like manner, a filling space is formed in an upper area into which the material to be crushed is introduced.

If the knives are now driven, the movement of the individual knives causes the material to be comminuted accordingly.

With such shredders it has happened that the knives were no longer able to work optimally due to thermal loads. Shredded material has also settled in an area of the bearing shafts and thus restricted the functionality of the shredder. These often had to be removed manually.

The U.S. 2,675,181 A discloses a device for crushing ice, wherein breaker blades are eccentrically mounted with their upper end on two parallel shafts and are movably connected with their lower end on one below the upper two shafts on a parallel lower shaft.

The object of the invention is to improve the state of the art.

The object is achieved by a cutting element, in particular a knife, for a device for comminuting materials, the device having a plurality of cutting elements which can be moved towards one another and which engage in one another in a comb-like manner in a first row and in a second row and one after the other Above extended angle α are arranged and mounted on a common bearing shaft, wherein the cutting elements of the first row with cutting elements of the second row are arranged in a cutting area partially touching each other and the cutting elements of the first row a first eccentric drive shaft and the cutting elements of the second row a second eccentric drive shaft is assigned so that the cutting elements perform a cutting movement when the first eccentric shaft is driven and / or when the second eccentric shaft is driven, and the cutting element has a bearing shaft receptacle on the bearing shaft side, which is opened on one side Fnete recess is formed so that shredded material, which may get into the bearing shaft receptacle, falls out downwards.

Thus, compared to generic shredders, such as those in the DE 44 08 964 A1 or in the EP 0 714 322 B1 describe significant improvements.

A technical feature is in particular that in the present case only a single bearing shaft is provided for the respective rows with cutting elements.

This has the consequence that on the one hand the bearing shaft as such no longer bends and on the other hand that the thermal input is reduced

Due to the fact that in the present case only one bearing shaft is used, in the present case, through the bearing shaft receptacle provided on the bearing shaft side of a cutting element with its open recesses, crushed material located in the recess is conveyed downward due to gravity, for example into a collecting space. Thus, temperature input due to friction between the shafts and the cutting elements with possibly disruptive comminuted material is also advantageously reduced.

The following terms are explained:

A “cutting element” is in particular a knife for a shredder. If a plurality of cutting elements are arranged offset opposite one another, for example in a shredder, a cutting effect is formed due to the movement of the cutting elements at the respective adjacent edges of two cutting elements. In particular, two edges of each cutting element form a cutting edge for the material to be comminuted, so that a pair of cutting edges is present. Thus, two adjacent knives opposite one another act like the cutting edges of scissors.

A “device for shredding materials” is in particular a shredder. The generic structure of such a shredder can DE 44 08 964 A1 and the EP 0 714 322 B1 which describe the function of the present devices for comminuting materials generically and whose related content is adopted here. The two bearing shafts are replaced in particular by a common bearing shaft.

Such a device for comminuting materials has a plurality of cutting elements. These are usually arranged in a row parallel to one another in such a way that two cutting elements adjacent in a row are approximately so far apart that a cutting element of the second row can engage in this gap. Since the cutting knives are also arranged essentially parallel to one another, each with a section of a cutting knife width, the first row of cutting elements and the second row of cutting elements can engage in one another in a comb-like manner.

In order to provide a “filling space”, the cutting elements form an upwardly open angle when engaged. A filling space can thus be provided.

A “cutting area” is the area of two opposing cutting elements that perform a cutting movement and that have a cutting effect on a material located there. The cutting area can start, for example, at a lower edge area, where the two cutting elements touch each other in a lowermost position of the cutting elements or correspondingly quasi-touch, up to the area, in each case an upper position, in which the edges of two opposing and cutting engagements are located Also touch or quasi-touch cutting elements.

A “common bearing shaft” supports the respective cutting elements in a lower area of the shredder in such a way that they can move around the common bearing shaft.

In particular in an upper region of the cutting elements, the cutting elements of the first row and the cutting elements of the second row are each assigned an eccentric drive.

This "eccentric drive" impresses an eccentric movement on each individual cutting element. For example, a shaft can be driven by a motor and different positions can be impressed on the different knives by the eccentric drive, so that not all knives move uniformly towards and away from each other, but rather that defined movement patterns can be set using the eccentric setting.

In the case of a cutting element, the “bearing shaft side” is the lower area which, in particular, is in engagement with the bearing shaft in the installed state.

The “bearing shaft receptacle” is in particular the area through which the bearing shaft is guided. This bearing shaft receptacle is in particular a “recess open on one side”, which is designed, for example, as an elongated hole, with a connection area of the elongated hole being free of material. Thus, during the cutting movement, the cutting element can be partially guided along the recess and comminuted material that has entered the recess can fall down through the opening, for example into a material receiving area (collecting basket), due to gravity.

In a further embodiment, the opened recess is formed by two legs and one of the legs has a leg width that is 1.5 times to 10 times, in particular 3 times to 6 times wider than a leg width of the other leg, so that a recess of an adjacent cutting element of the opposite row is partially covered during a cutting movement. In this way, an additional measure can be provided which basically prevents comminuted material from getting into the recess.

This is particularly advantageous when the wider leg has a convex configuration which is shaped outward from the recess. The cutout can thus at least partially cover the cutout over the entire cutting movement with a minimized use of material and optimized use of space.

“Outward from the recess” is a radial outward direction, particularly when the cutting element is mounted on the bearing shaft.

In order to reduce the temperature input or a corresponding heat input and thus the load on the cutting elements, the cutting element can have a bearing section arranged downstream of the cutting area on the bearing shaft side and a bearing section material thickness of the bearing section can be designed to be less than a cutting area material thickness of the cutting area, so that a surface friction of two adjacent bearing sections of two adjacent ones Cutting elements is reduced.

The “cutting area material thickness” is in particular the material thickness of the cutting element and is maximum in particular in the cutting area. This cutting area material thickness corresponds in particular approximately to the distance between two adjacent cutting knives in a row.

The “bearing section material thickness” is analogously the thickness of the bearing section area, the bearing section material thickness having a lower value than the cutting area material thickness.

It has surprisingly been found here that this measure enables continuous operation of the present generic devices for comminuting material.

"Friction" occurs especially when two materials that are touching move against each other. Due to the high mechanical forces that are present in a shredder, for example, two knives that are adjacent to one another can have a touching area during operation and thus generate harmful heat generation. Practically, the bearing section material thickness of the bearing section is 0.1 to 3.0 mm less than the cutting area material thickness, but higher values are also possible here.

In order to further reduce the heat input in a device for comminuting materials, a bearing shaft contact surface of the bearing shaft receptacle can be reduced compared to a bearing shaft plan contact surface of the bearing shaft receptacle, so that friction between the bearing shaft contact surface and the bearing shaft is reduced.

Thus, the areas in contact are reduced overall. In the present case, the thickness of the bearing shaft receptacle corresponds to the thickness of the bearing section material. In the contacting area of the bearing shaft receptacle, which in principle can form a mechanically touching contact with the bearing shaft during operation, this area is again significantly reduced. This can be implemented in a trapezoidal shape, for example, when viewed in a cross section. The corresponding contact area is in particular reduced by 50% or more compared to the bearing shaft plan contact area.

The "bearing shaft plan contact area" is, in particular, the area which is unprocessed due to the given bearing section material thickness.

It is particularly advantageous if the bearing shaft contact surface is convex. A touching mechanical contact of the bearing shaft receptacle with the bearing shaft takes place in only a small “curved” area of the convex configuration. This significantly reduces the mechanical contact area once again.

In a further embodiment, the cutting element has a catching edge or offset catching edges essentially orthogonal to a cutting edge, so that material to be comminuted is caught in a filling space formed by the two comb-like interlocking rows of cutting elements and fed to the cutting area.

Such catching edges, also called fangs, can not only “catch” the material to be shredded, but can also compress and / or shatter the material due to the movement of the cutting elements, so that the actual cutting can take place better.

If, for example, PET bottles are shredded, then strong mechanical forces are present. In particular, this can lead to material residues “flying around” in the filling chamber when the PET bottles are cut.

Due to the fact that the catching edges form a kind of step-like structure in the filling area, the "flying around" shredded material can get caught there and is fed down to the individual cutting areas due to gravity and the angle of the comb-like interlocking cutting element rows, with another Comminution takes place.

In particular, the cutting surface formed by the cutting edge is thus orthogonal to the catching edge. In a practical shredder, the catching edge is thus arranged essentially parallel to the floor surface.

In order to receive a drive shaft, and in particular an eccentric shaft, the cutting element can have an eccentric shaft receptacle which is distal and is arranged away from the bearing shaft receptacle.

“Distal” is to be understood as being away from the center of a cutting element. In the present case, the eccentric shaft receptacle is therefore located on the other side of the cutting element in relation to the bearing shaft receptacle and is arranged at the top, in particular in the case of a shredder.

In a further aspect, the object is achieved by a device for comminuting material with a plurality of cutting elements which can be moved towards one another, which in a first row and a second row engage in one another in a comb-like manner and are arranged at an upwardly widened angle, so that a Filling space is formed, and the cutting elements are mounted on a common bearing shaft, wherein cutting elements of the first row with cutting elements of the second row are arranged in a cutting area partially in contact with each other and the cutting elements of the first row have a first eccentric shaft and the cutting elements of the second row have a second eccentric drive shaft is assigned, so that when the first eccentric shaft is driven and / or when the second eccentric shaft is driven, the cutting elements perform a cutting movement, a cutting element being a previously described cutting element.

In this device, the heat input or, correspondingly, the temperature input, which results in particular from friction, can be significantly reduced. In addition, the number of shredded materials that could get into the bearing shaft receptacle is reduced, so that additional friction due to the shredded materials is also reduced. The definitions made previously apply analogously to the device.

In one embodiment, the device has two opposing delimitation elements which, on the one hand, can help to form the filling space and, on the other hand, apply an adjustable pressing force to the cutting elements of the first and second rows. These delimiting elements can, for example, have a triangular shape and in principle prevent "flying around" comminuted material from being carried over the side areas of the filling space. In addition, the cutting elements can also be pressed so that the cutting action of the cutting elements can be influenced in this regard. In particular, if a screwing device is provided in each corner in the case of a triangular configuration of the delimiting elements, the pressing forces of the cutting elements can be adjusted.

It is particularly advantageous if the delimitation elements are made of lubricious plastic. For example, this is polyoxymethylene (abbreviation POM, also called polyacetal, polyformaldehyde or just acetal). In particular, lubricious means that the plastic has a low coefficient of friction compared to other plastics.

• 1 eine schematische Darstellung zweier gegenüberliegend angeordneter, benachbarten Schneidmesser, welche auf einer gemeinsamen Welle eines Schredders lagern.

The invention is explained in more detail below using an exemplary embodiment. It shows

• 1 a schematic representation of two oppositely arranged, adjacent cutting knives, which are mounted on a common shaft of a shredder.

A shredder (not shown) has a first row of knives 101 and knife of a second row 103 on. These knives are on a bearing shaft 121 each with its recess 105 stored. The recess 105 is open on one side and has a first leg 109 and a second leg 111 on. The first leg 109 has a convex shape towards the outside. At its widest point is a leg width 113 of the first leg 109 about 4 times larger than a leg width of the second leg 111 .

The knives in the first row 101 and the knives of the second row 103 are to each other with an upwardly open angle α arranged. The eccentric shaft mountings are located in the upper area 120 the knife 101 , 103 .

The knives in the first row 101 point in their eccentric shaft mount 120 an eccentric drive shaft 141 and the knives of the second row 103 in their eccentric shaft mount 120 an eccentric drive shaft 143 the second row 103 on. The one between the knives in the first row 101 and the knives of the second row 103 training filling room 133 can be used for filling with material to be shredded. In the filling area 133 protrude from the knives in the first row 101 and from the knives in the second row 103 several catch edges each 119 .

The material thickness of the knives in the first row 101 and the knife second row 103 is opposite the material thickness in the cutting area 131 in the warehouse section 115 reduced by 2 mm. In addition, the recess 105 each have a convex inner surface, which in operation the bearing shaft 121 contacted.

When the shredder is operated, a motor (not shown) shapes the eccentric drive shafts 141 , 143 a rotation. This causes the knives to be the first row 101 and the knives of the second row 103 moving towards each other and in the cutting area 131 the knives 101 , 103 touch.

Due to the eccentric movement of the knife 101 , 103 the recess rises and falls 105 , which is also superimposed by a partially rotating movement.

If material such as a PET bottle is placed in the filling area 133 thrown in, it falls down due to gravity. The catch edges 119 grasp the PET bottle and convey it to the cutting area due to gravity 131 . There the knives of the first row cut up 101 and the knives of the second row 103 the bottle, with the catch edges 119 also develop a holding force. The bottle is made by the cutting movement of the knife 101 , 103 shredded and the shredded material falls through the gaps between the respective knives 101 , 103 down into a collecting room.

Crushed bottle material, which is in the recess 105 "Lost" falls due to the opening of the recess 105 downwards also into the collecting container.

List of reference symbols

101

First row knife (cutting element)

103

Second row knife (cutting element)

105

Recess

107

Bearing shaft mount

109

first leg

111

second leg

113

Leg width

115

Warehouse section

117

Bearing contact area

119

Catch edges

120

Eccentric shaft mount

121

Bearing shaft

131

Cutting area

133

Loading area

135

Knife center

141

Eccentric drive shaft first row

143

Eccentric drive shaft second row

α

angle

Claims (11)

Cutting element (101, 103), in particular knife, for a device for comminuting materials, the device having a plurality of cutting elements (101, 103) which can be moved towards one another and which engage in a comb-like manner in a first row and in a second row and are arranged at an upwardly widened angle (α) and are mounted on a common bearing shaft (121), wherein cutting elements of the first row (101) with cutting elements of the second row (103) are arranged in a cutting area (131) partially in contact with one another and the cutting elements of the first row (101) are assigned a first eccentric drive shaft (141) and the cutting elements of the second row (103) are assigned a second eccentric drive shaft (143), so that the cutting elements (101, 103) when the first eccentric shaft (141) and / or perform a cutting movement when the second eccentric shaft (143) is driven, characterized in that the cutting element (101, 103) has a bearing shaft receptacle (107) on the bearing shaft side, which is formed by a recess (105) open on one side, so that comminuted material which gets into the bearing shaft receptacle falls out downwards. Cutting element (101, 103) Claim 1 , characterized in that the opened recess (105) is formed by two legs (109, 111) and one of the legs (109) is 1.5 times to 10 times, in particular 3 times to 6 times, wider than the other leg (111), so that a recess of an adjacent cutting element of the opposite row is partially covered during a cutting movement. Cutting element (101, 103) Claim 2 , characterized in that the wider leg (109) has a convex configuration which is shaped outward from the recess. Cutting element (101, 103) according to one of the preceding claims, characterized in that the cutting element (101, 103) has a bearing section (115) arranged downstream of the cutting area on the bearing shaft side and a bearing section material thickness of the bearing section (115) is designed to be less than a cutting area material thickness of the cutting area, so that surface friction between two adjacent bearing sections (115) of two adjacent cutting elements (101, 103) is reduced. Cutting element (101, 103) according to one of the preceding claims, characterized in that a bearing shaft contact surface (117) of the Bearing shaft receptacle (107) is reduced compared to a bearing shaft plan contact surface (117) of the bearing shaft receptacle (107), so that friction between the bearing shaft contact surface (117) and the bearing shaft (121) is reduced. Cutting element (101, 103) Claim 5 , characterized in that the bearing shaft contact surface (117) is planar or convex towards the long wave. Cutting element (101, 103) according to one of the preceding claims, characterized in that the cutting element (101, 103) has a catching edge (119) or mutually offset catching edges (119) essentially orthogonal to a cutting edge, so that in one through the two intermeshing rows of cutting elements (101, 103) formed filling space (133) flying around material to be comminuted is caught and fed to the cutting area. Cutting element (101, 103) according to one of the preceding claims, characterized by an eccentric shaft receptacle (120) which is arranged distally and remote from the bearing shaft receptacle (107). Device for comminuting materials with a plurality of cutting elements (101, 103) which can be moved towards one another, which in a first row (101) and in a second row (103) engage in one another like a comb and with an upwardly widened angle (α) are arranged so that a filling space (133) is formed, and the cutting elements (101, 103) are mounted on a common bearing shaft (121), cutting elements of the first row (101) with cutting elements of the second row (103) partially in a cutting area are arranged in cutting contact with one another and the cutting elements of the first row (101) are assigned a first eccentric drive shaft (141) and the cutting elements of the second row (103) are assigned a second eccentric drive shaft (143), so that the cutting elements (101, 103) are assigned when the first eccentric shaft ( 141) and / or perform a cutting movement when the second eccentric shaft (143) is driven, characterized in that a cutting element (101, 103)) is a cutting element (101, 103) according to one of the preceding claims. Device according to Claim 9 , characterized by two opposing delimitation elements which on the one hand delimit the filling space (133) laterally and on the other hand apply an adjustable pressing force to the cutting elements of the first and second rows (101, 103). Device according to Claim 11 , characterized in that the limiting elements have a lubricious plastic.

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