Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
  • B25D—PERCUSSIVE TOOLS
  • B25D17/00—Details of, or accessories for, portable power-driven percussive tools
  • B25D17/02—Percussive tool bits
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
  • B22D19/00—Casting in, on, or around objects which form part of the product
  • B22D19/06—Casting in, on, or around objects which form part of the product for manufacturing or repairing tools
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
  • B25D—PERCUSSIVE TOOLS
  • B25D2222/00—Materials of the tool or the workpiece
  • B25D2222/21—Metals
  • B25D2222/42—Steel

Definitions

• the invention relates to a composite tool for impact loads.
• Such tools are used, for example, to shred metal, rock or demolition materials.
• the tools are exposed to extreme loads both in the area of their surfaces that come into direct contact with the material to be shredded and in the area in which they are held in the respective shredding machine.
• a disadvantage of the simple monoblock tools explained above is that they have a consistently low base hardness or are made from impact-hardening materials. As a rule, they show insufficient wear resistance. With highly or differentiated, over several sections differently hardened monoblock tools, on the other hand, often run the risk of breaking in zones that are particularly hard and, with it, have low ductility.
• Tools for impact loads which are produced by composite casting are also known.
• the lock-resistant molded body is generally held in the material of the base body by a material connection.
• a disadvantage of these tools is the high cost of their manufacture, which results from the high cost of materials and complex process control.
• Tools of this type are known for example from DE-PS 592 580.
• the invention proposes a composite tool for impact loads that comprises a base body produced from a highly ductile, impact-hardening iron-based alloy and at least one base body cast into the base body, largely excluding one Has cohesive connection form-fitting molded body which is arranged in the area of the composite tool directly exposed to the impact load and is prefabricated as a solid body from a highly wear-resistant metal material which differs from the iron material of the base body.
• the tool according to the invention essentially consists of a base body which is produced from a cast, highly ductile material.
• a shaped body is placed in the zone of this base body, which is impacted and / or abrasively during operation, and is made of a high-strength, also metallic, preferably iron-based alloy.
• the shape of the shaped body is selected so that the shaped body is securely held in a form-fitting manner in the material of the base body surrounding it.
• the materials of the base body and molded body are matched to one another in such a way that there is no significant material connection between the molded body and the base body. It is also not provided according to the invention that the shaped body is replaced by additional mechanically acting 'resource is held in the base body.
• the invention provides a tool which can be used universally in comminution machines and is particularly easy to produce, which has a high wear resistance in its working zone exposed to primary wear due to the molded body arranged there and at the same time has a significantly reduced sensitivity to breakage. Since the high impact or abrasive loads are absorbed by the molded body made of hard, wear-resistant material, the base body material and the heat treatments used in its processing can be designed for the highest possible ductility of the base body regardless of the loads occurring in practical operation.
• the heat treatment used in the production of composite tools according to the invention provides that the heat control during the manufacturing process takes into account the necessary parameters for the two materials to be combined.
• the aim is to produce the highest possible ductility in the base body and the highest possible hardness in the molded body. This is achieved by treatment in the high temperature range of 950 - 1100 ° C. This is followed by broken liquid hardening in the range of 350 - 600 ° C, which is then followed by cooling in air and subsequent relaxation at temperatures of 300 - 400 ° C.
• the molded body can be prefabricated in any inexpensive manner. This can be the case with the molded body cast into the tool according to the invention for example, a forged part, a stamped part, a cut part, a fired part, a sintered part or a casting.
• the stamped part, burned or cut part can be made from a flat material.
• the selection of the materials used for the base body and the molded body ensures that the specific mechanical-technological properties of both materials, namely on the one hand highly wear-resistant for the molded body and on the other hand highly ductile for the base body, are retained both during the manufacturing process itself and in practical use.
• An iron alloy that (in% by weight) 8.0 - 22.0% Mn, 0.2 - 2.8% Cr, 0.5 has proven to be a suitable material for the production of the base body, which fulfills these requirements - 1.5% C and the rest contains Fe and unavoidable impurities.
• an iron alloy that enables a high hardness of the molded body contains (in% by weight) 6.0-16.0% Cr, 0.3-1.5% Mo, 0.3-1.4% W, 0.6 - 2.2% C and the balance Fe and unavoidable impurities. Supported by a heat treatment tailored to the respective material compositions, these alloys can be used to produce particularly long-lasting, robust tools that can withstand even the toughest loads over the required service life. ' The materials of the base body and molded body can be matched to one another within the alloy specified according to the invention in such a way that the molded body is permanently clamped in the tool during and as a result of the use stress.
• the invention is characterized in that in the area in which the iron material of the base material laterally surrounds the molded body, the ratio of the average thickness of the base material measured in a first axis to the average thickness of the cast molded body measured in the same axis is 0.2 to 1.0 If this range of strength ratios is taken into account, a high level of security against breakage is guaranteed, even with strongly changing loads in the area of the clamping and storage zone of the tool.
• a tool according to the invention is deliberately produced in such a way that there is no substantial metallic bond between the molded body and the base body at least partially surrounding it.
• the molded body is rather designed such that the molded body is embedded in a form-fitting manner in the material of the base body.
• the molded body can have a shape tapering from a base surface in the direction of its end surfaces opposite the base surface and the end surface can be assigned to the area of the composite tool that is directly exposed to the impact.
• Such a shape is given, for example, when the shaped body has the basic shape of a truncated pyramid. In the case of such a shape tapering essentially conically from the base to the end face, it is ensured in a simple manner that the molded body is held securely in the base body even after a long operating time.
• the form-fitting hold of the shaped body can also be achieved in that depressions are formed in the side surfaces of the shaped body. Alternatively or in addition, elevations can be formed on the side surfaces of the shaped body.
• the composite tools 1, 11, 21, 31 shown in FIG. 1 each have a cuboid-shaped base body 2, which is cast from a highly ductile iron material. Starting from its one narrow end face 2a, the base body 2 is in a working section 2b, which in practical use is exposed to direct contact with the material to be shredded and extends over about a third of the total length L of the base body 2, a clamping section adjoining the working section 2b 2c, on which, when the composite tool 1, 11, 21, 31 is mounted, the clamping device (not shown) of a comminution machine, also not shown, engages and divides a bearing section 2d adjoining the clamping section 2c, on which the tool 1 in the assembled position in the comminution machine is supported.
• a molded body 3 made of a high-strength, hard iron material is cast into the working section of the base body 1.
• the molded body 3 has a hexagonal base surface 3a with two opposing long sides, which are connected at their ends by two short sides meeting at an obtuse angle that is open towards the inner surface. Based on that shaped base 3a, the molded body 3 tapers in the direction of the end face 2a of the base body 2.
• a shape of the molded body 3 that tapers conically starting from the base surface 3a in the direction of the end surface 3b of the molded body 3 assigned to the end surface 2a of the base body 2 is formed.
• the shaped body 3 shaped in this way is completely surrounded laterally in the new state of the tool 1 and in the area of its base 3a by the material of the base body 2.
• the mean thickness d G ⁇ of the wall 2f of the base body 2, which extends parallel to the end face 2a in the direction of the wider side faces of the base body 2 and is oriented perpendicularly to the measurement body X, is selected such that the The ratio of the average thickness d G ⁇ to the average thickness d F ⁇ of the shaped body 3 measured in the same measuring axis X is approximately 0.3.
• the thickness d G2 of the wall 2e of the base body 2 which is laterally surrounding the shaped body 3 in the width direction and measured in a measuring axis Y oriented transversely to the measuring axis X, is selected such that the ratio of the average thickness d G2 to the average thickness measured in the same measuring axis Y d F2 of the shaped body 3 is approximately 0.2.
• a molded body 13 made from a high-hard iron material.
• the material of the base body 2 completely surrounds the molded body 2 when the tool 11 is new.
• the molded body 13 of the tool 11 has a tapering shape, starting from its base 13a in the direction of its front side 13b assigned to the front side 2a of the base body 2.
• the base surface 13a and, accordingly, the end face 13b of the molded body are also hexagonal, the surfaces 13a, 13b in this case being delimited by two short, mutually opposite sides, each of which is opened by a blunt one to the respective surface 13a, 13b Longer sides that meet at angles are connected to one another.
• the essentially conical shape of the solid molded body 13, which tapers from the base surface 13a and the embedding of the molded body 13 in the material of the base body 12 ensures that the molded body 13 is still securely in the base body even after a long period of operation 2 held and is able to absorb the striking load directly striking the tool 11 just as securely.
• the working section 2b of the base body 2 is in turn off cast a solid metal material produced, solidly formed molded body 23.
• the material of the base body 2 completely surrounds the molded body 23 when new.
• the molded body 23 has a truncated pyramid-shaped basic shape, which has four side surfaces 23c, 23d, 23e, 23f, the base surface 23a of which is larger than its end surface 23b assigned to the end surface 2a of the base body 2.
• channel-like depressions 23g are formed at regular intervals and extending over the length of the molded body 23, while knob-like projections 23h are formed on the two other opposite side surfaces 23e, 23f in an irregular arrangement.
• the depressions 23g and the projections 23h in combination with the shape of the shaped body 23 tapering starting from the base area 23a in the direction of the end face 23b, support its secure, form-fitting hold in the material of the base body 2.
• the composition of the iron material of the base body 2 is so matched to the composition of the iron material from which the molded body 23 is made, that the molded body 23 is additionally non-positively held in the base body 2 under tension after the completion of the composite tool 21 due to the different thermal expansion behavior of the two materials.
• three molded bodies 33 ', 33''and33''' are cast in.
• the shaped bodies 33 ', 33'',33''' are each formed in the shape of a truncated pyramid and run from their rectangular base surface 33a in Direction of the end face 2a of the base body 2 of the tool 31 assigned and in the new state flush with this aligned end face 33b.
• the length of the shaped body 33 '' arranged between the two outer shaped bodies 33 ', 33''' is approximately . half the length of the other two shaped bodies 33 'and 33'''.
• the shaped bodies 33 ', 33''and33''' are arranged at a distance that both the ratio of the average thickness d Gi measured in the direction of the measuring axis X of the shaped bodies 33 ', 33''and33''' in each case in the thickness direction of the material of the base body 2 to the mean thickness d F ⁇ of the shaped bodies 33 ', 33'',33''' measured in the same measuring axis X and the ratio of the mean thickness d G2 measured in the direction of the measuring axis Y of the shaped bodies 33 ', 33''and33''' in the width direction of the material of the base body 2 in relation to the average thickness d F2 of the shaped bodies 33 ', 33'',33''' measured in the same measuring axis Y in the range from 0.2 to 1 , 0 lies.
• this allows the wall thicknesses d G ⁇ bz to be matched to the thickness d F ⁇ , d F ⁇ of the shaped body 33 ', 33'',33''' , ' d G2 ensures that the molded bodies 33', 33 '', 33 '''are held in the ductile iron material of the base body 2 in the tool 31 in a manner which is sufficiently elastic for a permanently secure hold, even under the hard loads occurring in practical use ,
• An important advantage of the composite tool 31 shown in FIG. 4 is that with the introduction of several harder shaped bodies 33 ', 33'',33''' into the highly ductile base body 2 by the between the individual shaped bodies 33 ', 33'',33''' existing ductile base material, the risk of breakage in practical use is significantly minimized.
• the different length of the Shaped body 33 ', 33'',33''' takes into account the limitation of the desired increased wear resistance to zones of the main wear stress.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Manufacturing & Machinery (AREA)
• Earth Drilling (AREA)
• Polishing Bodies And Polishing Tools (AREA)
• Laminated Bodies (AREA)
• Percussive Tools And Related Accessories (AREA)
• Forging (AREA)

Applications Claiming Priority (2)

Publications (2)

Family

ID=34129501

Family Applications (1)

Country Status (6)

Cited By (1)

Families Citing this family (1)

Family Cites Families (11)

• 2003
  • 2003-08-07 DE DE20321302U patent/DE20321302U1/de not_active Expired - Lifetime
  • 2003-08-07 DE DE10336169A patent/DE10336169B4/de not_active Expired - Fee Related
• 2004
  • 2004-08-02 AT AT04763716T patent/ATE493233T1/de active
  • 2004-08-02 EP EP04763716A patent/EP1651389B1/fr not_active Not-in-force
  • 2004-08-02 DK DK04763716.0T patent/DK1651389T3/da active
  • 2004-08-02 WO PCT/EP2004/008648 patent/WO2005014238A1/fr active Application Filing
  • 2004-08-02 ES ES04763716T patent/ES2358594T3/es active Active
  • 2004-08-02 DE DE502004012067T patent/DE502004012067D1/de active Active

Non-Patent Citations (1)

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