EP2558211B1 - Beater bar for an impact crusher, in particular a rotary impact crusher - Google Patents

Description

The invention relates to a blow bar for a rock impact crusher, in particular a rotary impact crusher.

From the EP 0 581 758 B1 a rotary impact crusher is known which is equipped with several blow bars. The blow bar comprises a carrier which can be clamped on a clamping claw via a wedge clamp. The blow bar can thus be fixed to the rotor of the rotary impact crusher in an exchangeable manner. The carrier has a seat facing in the tool feed direction, on which several cutting elements can be placed and strung together in the longitudinal direction of the blow bar. The cutting elements are initially placed loosely on the carrier. As soon as the wedge connection is tightened, the cutting elements are also fixed captive on the carrier. If one or more of the cutting elements are worn, the clamping connection must be released. Then the respective cutting elements can be replaced by unworn cutting elements. This known type of fixation of the cutting elements on the carrier has proven to be unsuitable in practice. In particular, if the blow bar to be serviced is in a lower position of the rotor, the cutting elements can fall down in an uncontrolled manner after the clamping connection has been released and then have to be laboriously collected and threaded onto the carrier. Furthermore, the contact surfaces of the carrier and the cutting elements must be matched to one another very precisely in order to enable a gap-free connection. Since the cutting elements designed as sintered parts can only be manufactured within a certain tolerance band, the gap-free assignment to the carrier can never be completely guaranteed, so that the cutting elements then break frequently.

Another blow bar is from the DE 23 43 691 known. Three hard metal plates are attached to a carrier. Here, too, there is a screw connection are used, which clamps the hard metal plates in recesses in the carrier. A similar arrangement is also from the DE 295 21 050 U1 known, in which the carrier of the blow bar has a dovetail-shaped groove into which the strip-shaped cutting element can be inserted with a dovetail-shaped plug-in attachment. With such blow bars, there is often the risk that a hernia will occur due to strong punctual impact stress. Then the entire cutting element has to be exchanged at great expense.

The DE 16 58 400 U1 shows another blow bar in which a hard metal block extending over the entire width of the blow bar is soldered to a carrier.

From the GB 2 202 463 an impact crusher is known which has a main shaft within the housing on which a rotating body is held with firmly attached mallets. The flails break up pieces of rock and make them fly, with a plurality of hard metal plates being attached to the outer end of each flail and being held releasably at this end. The rock pieces are crushed by a rebound plate and thrown back.

The object of the invention is to provide a robust blow bar that is easy to maintain.

This object of the invention is achieved with a
Impact bar for an impact crusher, in particular a rotary impact crusher with a carrier released, which has a recess, one or more cutting inserts being interchangeably fastened in the recess, the cutting set having a cutting element holder with which several cutting elements consisting of a hard material are connected, the The cutting element holder has a rear abutment surface which runs opposite to the tool feed direction and via which a fastening attachment that is integrally formed on the cutting element holder protrudes, and wherein the cutting elements are arranged transversely to the tool feed direction side by side and form a cutting edge.

The attachment attachment is preferably provided with a threaded receptacle. This cutting insert can be installed quickly and easily on a carrier of a blow bar. For this purpose, the cutting insert only has to be inserted with its integrally formed fastening lugs into fastening receptacles provided for this purpose on the carrier. The cutting insert can then be screwed to the carrier via the threaded receptacles of the fastening attachment. The fastening lugs release the fastening screws from transverse forces acting during the use of the tool. A stable coupling of the cutting insert to the carrier is thereby achieved. In the event of damage, the cutting insert can easily be replaced by loosening the threaded connections and then removing the cutting element holder from the carrier. It can then be exchanged for a new, unworn cutting insert.

The fastening attachment can then be manufactured simply and dimensionally precisely if it is provided that it has a square or rectangular cross section.

The central longitudinal axis of the threaded receptacle is preferably vertical to the contact surface, so that the forces induced by the fastening screw are transferred directly to the contact surface. It has been shown that this enables a very stable and break-free coupling of the cutting attachment.

Two or more cutting element holders are installed to form the cutting edge. These in turn carry two or more cutting elements. The cutting element holders thus form assemblies that can be handled in a uniform manner, which can be securely attached to the carrier in a short time in order to form the cutting edge. If When a cutting element has reached its wear limit due to wear, the cutting element holder that carries this cutting element can be removed and replaced independently of the other cutting element holders. This means that maintenance can be carried out in a time-optimized, economical and safe manner.

According to a preferred variant of the invention, it is provided that the cutting elements are materially connected to the cutting element holder, in particular soldered to it. This provides an association between the cutting elements and the cutting element holder that is free of gaps and not at risk of breakage.

A preferred embodiment of the invention is such that the recess has a support surface and a support surface at an angle thereto, the support surface pointing in the tool feed direction, that the contact surface is supported on this support surface, and that the cutting element holder has a base adjoining the contact surface sits flat on the support surface. The inventor has recognized that a varying force profile occurs during tool engagement. The support surface and the support surface reliably absorb these machining forces and divert them into the carrier so that the cutting element holder is always securely fixed.

A possible alternative to the invention is such that the cutting element holder is connected to the carrier by means of at least one fastening attachment that is inserted into a fastening receptacle, and that the fastening attachment has a threaded receptacle that is in alignment with a screw receptacle that opens into the fastening receptacle. The fastening attachment can be arranged on the cutting element holder and the fastening receptacle on the carrier (or vice versa). The fastening attachment is supported in the case of transverse forces in the fastening receptacle and transfers the forces via this support area. This means that the fastening screws that connect the cutting element holder to the carrier are from Shear forces exempt. With this simple measure, a significantly improved force dissipation is possible.

If it is provided that the cutting element holders can be positioned on the carrier in a pre-assembly position in which they can be adjusted relative to one another, then the cutting element holders can be pushed against one another without play in the pre-assembly position and then finally fixed. As a result, the cutting elements can be pushed against one another without play, so that no harmful transverse forces can become effective in the connection points during tool use.

To implement this embodiment, a blow bar according to the invention provides that the fastening attachment is inserted with play in the fastening receptacle, and that when the connection, preferably a threaded connection, is released, the cutting element holder can be adjusted to a limited extent in the direction of the longitudinal direction of the cutting edge.

If it is provided that the carrier has screw receptacles, which are introduced into the carrier from the rear side facing opposite to the tool feed direction, and that fastening screws are passed through the screw receptacles and screwed into the cutting element holder, then the screw head is protected against wear on the rear side of the carrier positioned. The fastening screw can then always be reliably loosened if necessary. If it is also provided that the fastening screw is screwed into a threaded receptacle of the cutting element holder designed as a blind hole, then the threaded receptacle is also housed protected and no crushed material can penetrate into the threaded area that would block the threaded connection.

In order to minimize wear on the carrier, one variant of the invention provides that the cutting element holder has a chip deflection surface lying radially on the outside opposite to the tool feed direction, which merges flush into a deflection surface of the carrier. The carrier is thus covered here by the cutting element holder and protected from the rock material to be broken.

A blow bar according to the invention can be such that a front surface of a base part of the carrier adjoins the cutting element holder transversely to the tool advance direction, and that an impact rocker is connected to the base part facing away from the cutting insert. It has been shown that with the inventive equipping of the blow bar with cutting elements, the wear in the area of the cutting edge is first optimized. This then, surprisingly, also results in reduced wear on the impact rocker.

A particularly preferred variant of a beater bar provides that the cutting element holder has a base that adjoins the contact surface at right angles. With the bottom and the contact surface, the cutting insert can be optimally supported on corresponding contact surfaces of the carrier.

If it is provided that the cutting element holder has a seat surface of a cutting element receptacle that is inclined opposite to the tool feed direction and on which the cutting elements are flatly coupled with a support section, then on the one hand an easily manufacturable geometry of the cutting element holder is ensured. On the other hand, the inclined seat surface optimally takes into account the varying force profile during tool engagement and thus serves to reliably support the cutting element. The cutting element can in particular be soldered onto the seat surface in order to ensure a connection without play.

A further wear protection of the cutting insert can be effected in that the cutting element holder has a receiving area on which several wear protection plates made of hard material are lined up in the longitudinal direction of the cutting insert, the wear protection plates directly adjoining the cutting elements. As a result of the fact that several wear protection plates are used, a segmented construction is realized which results in a significantly reduced risk of breakage for the wear protection plates. The lining up of the wear protection plates, which in particular should be free of gaps, prevents impermissible transverse forces from acting on the wear protection plates and thereby breaking them. Since the wear protection plates adjoin the cutting elements directly, the area below the cutting elements is reliably prevented from being washed out by the wear protection plates.

In this case, it can advantageously be provided that two wear protection plates are installed per cutting element, the cutting elements having a width that is twice as great as the wear protection plates in the longitudinal direction of the cutting insert.

A blow bar according to the invention can be characterized in that the cutting elements are triangular in cross-section and have a baffle surface pointing in the tool feed direction and a free surface at an angle to it and extending opposite to the tool feed direction, and that between the free surface and the tool -Feed direction pointing feed normal a clearance angle is included in such a way that the free surface slopes away from the cutting edge in the direction opposite to the tool feed direction. With this construction, a self-sharpening geometry is achieved for the cutting element. A sharp-edged cutting edge geometry is retained even if the cutting elements wear due to wear.

Figur 1

eine Schlagleiste in perspektivischer Seitenansicht,

Figur 2

die Schlagleiste gemäß Figur 1 in perspektivischer Rückansicht,

Figur 3

einen Schneideinsatz in perspektivischer Teildarstellung, der mit der Schlagleiste gemäß den Figuren 1 und 2 verbaubar ist,

Figur 4

den Schneideinsatz gemäß Figur 3 in Seitenansicht,

Figur 5

den Schneideinsatz gemäß Figur 4 in Frontansicht und

Figur 6

den Schneideinsatz gemäß den Figuren 3 bis 5 in perspektivischer Rückansicht.

The invention is explained in more detail below with reference to an exemplary embodiment shown in the drawings. Show it:

Figure 1

a blow bar in a perspective side view,

Figure 2

the blow bar according to Figure 1 in perspective rear view,

Figure 3

a cutting insert in a perspective partial representation, which with the blow bar according to the Figures 1 and 2 is buildable,

Figure 4

the cutting insert according to Figure 3 in side view,

Figure 5

the cutting insert according to Figure 4 in front view and

Figure 6

the cutting insert according to the Figures 3 to 5 in perspective rear view.

Figure 1 shows a blow bar which has a carrier 10. The carrier 10 has a base part 11 which forms a front surface 12 pointing in the tool feed direction (V). The base part 11 is laterally adjoined by a lower part 13, the impact rocker 13 having a surface inclined to the front surface 12. Facing away from the impact rocker 13, the base part 11 carries an attachment into which a recess 18 in the form of a milled recess is incorporated. This recess 18 forms a support surface 18.2 and a support surface 18.1 at an angle thereto. The support surface 18.2 pointing in the tool feed direction (V) merges into a deflection surface 19. At the rear, the carrier 10 has projections 15 which are used to fix it to a rotor of a rotary impact crusher. Support surfaces 14 are provided on both sides of the projections 15. In the area of the impact rocker 13, the carrier 10 forms a seat surface 17. This is arranged at an angle to the rear support surface 14. By means of the support surface 14 and the seat surface 17, the carrier 10 can on the Rotor are reliably supported. How Figure 1 can be seen, four cutting inserts 20 are built into the recess 18, which are arranged next to one another in the longitudinal extension of the carrier 10.

Figure 2 shows the arrangement according to Figure 1 in perspective rear view. As can be seen from this illustration, three projections 15 are formed on the rear side of the base part 11 and are separated from one another by grooves. Starting from the rear side of the carrier 10, fastening receptacles 16 are introduced into the carrier 10 in the form of bores. These bores open into the support surface 18.2 of the recess 18. Fastening screws 16.1 can be passed through the fastening receptacle 16 and screwed into the cutting inserts 20, as will be explained in more detail later.

How Figure 3 As can be seen, the cutting insert 20 comprises a cutting element holder 21 to which cutting elements 23 and wear plates 22 are attached. The cutting element holder 21 has a vertical contact surface 21.8, to which a base 21.1 is connected via a bevel 21.10. In the assembled state, the base 21.1 is supported on the support surface 18.1 of the carrier 10 and the contact surface 21.8 is supported on the support surface 18.2. The bevel 21.10 guarantees reliable contact with the support surface 18.2 or the bearing surfaces 18.1. The bottom 21.1 merges at the front into a sloping transition section 21.2. A front surface 21.3 adjoins the transition section 21.2 and is positioned at an angle greater than 90 ° with respect to the bottom 21.1 running in the feed direction. This setting angle is particularly preferably selected in the range between 95 ° and 120 ° in order to enable a geometry that is favorable to wear. Above the front surface 21.3 there is a cutout 21.5 into which the wear protection plates 22 are inserted. The milled recess 21.5 is dimensioned such that the surfaces of the wear protection plates 22 merge flush with the front surface 21.3. The cutout forms a contact surface 21.4 on which the wear protection plates 22 can be aligned. This simplifies production possible. The wear protection plates 22 are soldered to the rear in the cutout 21.5 by means of hard solder.

A seat 21.6 adjoins the cutout 21.5. This seat surface 21.6 is inclined opposite to the tool feed direction V and towards the rear of the cutting insert 20. The cutting element 23 can be soldered to a flat support section 23.6 on the seat surface 21.6. The cutting element 23 is dimensioned in such a way that it covers the facing end face of the wear protection plate 22 with a protrusion 23.4 on the underside, a front impact surface 23.3 merging flush with the front face of the wear protection plates 22. This gap-free and flush transition prevents crushed material from penetrating and exerting impermissible shear forces on the cutting elements 23 and the wear protection plates 22. Such shear forces would expose the wear protection plates 22 made of hard metal or the cutting elements 23 to a risk of breakage. The impact surface 23.3 is inclined and points in the tool feed direction V. The impact surface 23.3 forms an angle <90 ° with a free surface 23.1, a cutting edge 23.2 being formed in the transition area between the free surface 23.1 and the impact surface 23.3. The free surface 23.1 in turn merges flush with a deflecting surface 21.7 of the cutting element holder 21.

FIG. 47 shows that the cutting elements 23 are laterally provided with side surfaces 23.5 running in the tool feed direction V. The cutting elements 23 can be lined up flush with one another without any gaps via these side surfaces 23.5. Two wear protection plates 22 are installed for each cutting element 23, the two wear protection plates 22 having a total width that corresponds to the width of the cutting element 23.

How Figure 5 As can be seen, eight cutting elements 23 are preferably attached to a cutting element holder 21. Accordingly, sixteen wear protection plates 22 are used.

The Figures 4 and 5 show that on the back of the cutting element holder 21 three fastening lugs 21.9 protrude beyond the contact surface 21.8. The fastening lugs are square in cross section and penetrated by a blind hole-like threaded receptacle 24, as is the case in particular Figure 4 illustrated. The threaded receptacle 24 ends behind the wear protection plates 22 in the cutting element holder 21. The threaded receptacle 24 has a central longitudinal axis M which can be arranged in alignment with the fastening receptacle 16 of the carrier 10. The carrier 10 here has three recesses per cutting insert 20, which have a square cross-sectional shape corresponding to the fastening lugs 21.9. The internal dimensions of these recesses are selected to be slightly larger than the external dimensions of the fastening attachment 21.9. In this way, a game is created which enables a limited adjustment of the cutting insert 20 relative to the carrier 10 when the cutting insert 20 is in a non-fixed preassembly position.

Figure 4 also shows that the deflecting surface 21.7 merges flush with the free surface 23.1. Starting from the cutting edge 23.2, the free surface 23.1 runs inclined in the direction opposite to the feed direction and is at an angle α to the feed normal running in the tool feed direction V. In this way, a self-sharpening geometry is ensured which maintains the functionality of the sharp-edged cutting edge 23.2.

To assemble the cutting inserts 20, they are inserted with their fastening lugs 21.9 into the corresponding recesses 18 in the carrier 10. The fastening screws 16. 1 are then passed through the fastening receptacles 16 from the rear of the carrier 10 and screwed into the threaded receptacle 24 of the cutting element holder 21. The fastening screws 16.1 are not yet tightened, so that the cutting inserts 20 are in a pre-assembly position. Then the cutting inserts are 20 in Longitudinal direction L (see Figure 5 ) the cutting inserts 20 on the support surface 18.2 and the support surface 18.1 pushed against each other so that they lie against each other without a gap. The sliding movement is made possible by the play between the fastening lugs 21.9 and the recesses in the carrier 10. When the cutting inserts 20 are pushed together, the fastening screws 16 can be tightened with the prescribed torque and the cutting inserts 20 are then securely fastened to the carrier 10.

During the operational use, due to the contact with the rock materials to be smashed, wear of the cutting edge 23.2 of the cutting elements 23 occurs. The cutting elements 23 are worn in the vertical direction (that is, transversely to the feed direction V). How Figure 4 clearly illustrated, the cross-sectional shape of the cutting elements 23 is selected to be triangular, so that a high proportion of hard material is positioned in the region of the cutting edge 23.2. In this way, material-optimized, a long service life is made possible.

When the cutting elements 23 have now reached their wear limit, the cutting insert 20 can be exchanged without any problems. It is only necessary to loosen the respective fastening screws 16 and replace the cutting insert 20 with an unworn cutting insert 20. Occasionally, under inadmissible conditions of use, it can happen that a cutting element 23 of a cutting insert 20 breaks prematurely. Then this cutting insert 20 can easily be exchanged. For this purpose, only the fastening screws 16.1 of all cutting inserts 20 have to be loosened, the cutting inserts 20 pushed apart and then the defective cutting insert 20 removed. A new cutting insert 20 can be attached, the cutting inserts 20 pushed together again and the fastening screws 16 tightened. This maintenance work can be carried out easily and safely, since the cutting inserts 20 form compact, small assemblies which have a low weight and can be easily handled.

Claims (18)

1. Impact bar for an impact crusher, in particular a rotary impact crusher with a carrier (10) which has a recess (18), wherein one or more cutting inserts (20) are interchangeably fastened in the recess (18), wherein the cutting insert (20) has a cutting element holder (21) to which a plurality of cutting elements (23) consisting of a hard material are connected, wherein the cutting element holder (21) has a rear contact surface (21) extending in the opposite direction to the tool feed direction (V). 8), beyond which a fastening projection (21.9) integrally formed on the cutting element holder (21) projects, characterized in that the cutting elements (23) are arranged next to one another transversely to the tool feed direction (V) and form a cutting edge.
2. Impact bar according to claim 1,
   characterized by this,
   in that the cutting elements (23) are connected to the cutting element holder (21) with a material bond.
3. Impact bar according to claim 1 or claim 2,
   characterized in that the recess (18) has a supporting surface (18.2) and a bearing surface (18.1) at an angle thereto, the supporting surface (18.2) pointing in the tool feed direction (V),
   that the contact surface (21.8) is supported on the support surface (18.2), and
   in that the cutting element holder (21) rests flat on the bearing surface (18.1) with a base adjoining the contact surface (21.8).
4. Impact bar according to one of the claims 1 to 3,
   characterized in that the cutting element holder (21) is connected to the support (10) by means of at least one fastening attachment (21.9) which is inserted into a fastening receptacle.
5. Impact bar according to claim 4,
   characterized in that the fastening attachment (21.9) has a threaded receptacle (24) which is aligned with a screw receptacle (16.1) which opens into the attachment receptacle.
6. Impact bar according to one of the claims 1 to 5,
   characterized in that the cutting element holders (21) can be positioned in a pre-assembly position on the carrier (10), in which they can be adjusted relative to one another.
7. Impact bar according to one of the claims 4 to 6,
   characterized in that the fastening attachment (21.9) is inserted with play in the attachment mount, and in that, when the thread connection is loosened, the cutting element holder (21) can be adjusted to a limited extent in the direction of the cutting edge longitudinal direction (L).
8. Impact bar according to one of the claims 1 to 7,
   characterized in that the support (10) has screw receptacles (16) which are inserted into the support (10) starting from the rear side facing in the opposite direction to the tool feed direction (V), and
   that fastening screws (16.1) are passed through the screw receptacles (16) and screwed into the cutting element holder (21).
9. Impact bar according to claim 8,
   characterized in that the fastening screw (16.1) is screwed into a threaded receptacle of the cutting element holder (21) designed as a blind hole.
10. Impact bar according to one of the claims 1 to 9,
    characterized in that the cutting element holder (21) has a chip deflection surface (21.7) radially on the outside, opposite to the tool feed direction (V), which merges flush with a deflection surface (19) of the carrier (10).
11. Impact bar according to one of claims 1 to 10,
    characterized in that a front surface (12) of a base part (11) of the carrier (10) adjoins the cutting element holder (21) transversely to the tool feed direction (V).
12. Impact bar according to one of claims 1 to 11,
    characterized in that the cross section of the fastening attachment (21.9) has a square or rectangular geometry.
13. Impact bar according to claims 1 to 12,
    characterized in that the central longitudinal axis (M) of the threaded receptacle (24) is vertical to the contact surface (21.8).
14. Impact bar according to one of the claims 1 to 13,
    characterized in that the cutting element holder (21) has a bottom (21.1) which adjoins the contact surface (21.8) at right angles.
15. Impact bar according to one of the claims 1 to 14,
    characterized in that the cutting element holder (21) has a seat surface (21.6) of a cutting element receptacle which is inclined in the opposite direction to the tool feed direction (V) and to which the cutting elements (23) are coupled with a support section (23.6) in a planar manner.
16. Impact bar according to one of claims 1 to 15,
    characterized in that the cutting element holder (21) has a receiving region at which a plurality of wear protection plates (22) made of hard material are lined up in the cutting insert longitudinal direction (L), wherein the wear protection plates (22) adjoin to the cutting elements (23).
17. Impact bar according to claim 16,
    characterized in that two wear protection plates (22) are installed per cutting element (23), the cutting elements (23) having a width in the longitudinal direction (L) of the cutting insert which is twice as large as the wear protection plates (22).
18. Impact bar according to one of claims 1 to 17,
    characterized in that the cutting elements (23) are triangular in cross section and have an impact surface (23.3) pointing in the tool feed direction (V) and a free surface (23.1) at an angle thereto and extending opposite to the tool feed direction (V), and in that a clearance angle (α) is enclosed between the clearance surface (23.1) and the feed normal (N) pointing in the tool feed direction (V) in such a way that the clearance surface (23.1) slopes from the cutting edge in the direction opposite to the tool feed direction (V).

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