US3042195A

US3042195A - Receiver for metal extrusion presses and like power-driven machines

Info

Publication number: US3042195A
Application number: US780379A
Authority: US
Inventors: Muller Ernst
Original assignee: Hydraulik GmbH
Current assignee: Hydraulik GmbH
Priority date: 1957-12-18
Filing date: 1958-12-15
Publication date: 1962-07-03
Anticipated expiration: 1979-07-03

Description

3,042,195 LIKE July 3, 1962 w W. W W

E. MULLl-:R AL EXTRUSION PRESSES AND LI July 3, 1962 RECEIVER FOR MET Dec. 15. 1958 3,042,195 LIKE July 3, 1982 ite States Patent 3 042 195 RECEIVER FOR EXTRUSION PRESSES AND LIKE POWER-DRIVEN MACHINES Ernst Mller, Duisburg, Germany, assignor to Hydraulik GmbH., Duishurg, Germany Filed Dec. 15, 1958, Ser. No. 780,379 Claims priority, application Germany Dec. 18, 1957 1 Ciairn. (Cl. 207-15) The present invention relates, in general, to receivers for metal extruders and, in particular, to receivers of the type having shrunk-fit liners or sleeves.

The temperature changes required in a receiver for a metal extruder vary in accordance with the particular material which is to be processed in the extruder. For example, when processing liquidv lead in a cable sheathing press or in the extrusion of heavy metal, especially steel ingots, the receiver must be heatable in order to start the press; however, it must be cooled during the operation of the press.

The pressing of light metal in ingot form takes place at such a slow rate that the receiver must be heated during the pressing operation to prevent the escape or loss of the ingot heat.

For cooling liquid lead in cable presses, channels have been provided in the receiver jacket through which a cooling liquid or steam is passed. It is known in the prior art, in such a receiver, to provide a helical cooling channel in the inner bore of the jac'ket so that the Cooling liquid or the steam, as the case may be, passes directly over the inner sleeve or liner. In such a case, the steam is used also to heat the cable press. Only saturated steam can be effective for cooling the receiver, and since heating with the use of this saturated steam is possible only up to a temperature of about 100-l20 C., the remaining heat is taken from the first lead charge.

External heating of the receiver jacket is usually effected by the use of gas or electricity. However, this is disadvantageous in that a considerable temperature gradient -appears inside the receiver cross section, starting from the jacket, because of the temperature drop in the direction toward the inner sleeve.

The shrinking stresses necessary to absorb the pressing forces between the individual sleeves are thus considerably reduced so that the strainability of the receiver structure is also reduced.

It has been suggested also in the prior art to heat the inner sleeve and to accomplish this provision of bores in the sleeve for receiving heating medium was made. However, such heated inner sleeves have proven to be failures because they broke after a short operational time. As is well known to those `skilled in the art, an inner sleeve in a receiver for a metal extruder is subject to very high tangential and other tensile stresses, so that even sleeves without such inner bores sometimes break after a relatively short period of use. It is not possible With the present state of technology to produce long and thin bores with the required precision, nor is it possible to provide a satisfactory surface finish in the very hard material of these inner sleeves. Consequently, the bores frequently cause cracks in the sleeve, due to the unsatisfactory surface finish which leads to a rupture of the entire sleeve, especially since the cross-sectional areas, which are under tensile stress, are considerably reduced by the bores.

The reverse process takes place in the pressing of steel or heavy metal when the large 'amounts of heat, which are developed as a result of the ingot temperature, escape and cannot flow away fast enough. Due to the temperature gradient, intolerably high shrinking stresses are created which frequently cause rupture of the entire receiver.

It is an object of the present invention to provide Patentecl `liuly 3, 19'52 iCC means ensuring, in a receiver with an inner sleeve and, if necessary with an additional or intermediate sleeve, a much better control of temperature conditions within the receiver cross sectional area than was heretofore possible.

It is another object of the present invention to provide means attaining a truly effective heating or Cooling of the receiver not limited to the jacket, 'as was heretofore the case.

It is another object of the present invention to provide means achieving the heating and cooling of an inner sleeve without danger to the latter or to the receiver.

It is another object of the present invention to provide means conducive to the obviation of the difficulties heretofore encountered in providing longitudinal bores in the material used for the inner sleeves.

It is a further object of the present invention to provide means leading to a highly novel and efiicient method for heating a receiver of the descnibed type.

These and other objects of of the invention Will become further apparent from the following detailed description, reference being made to the accompanying drawings showing preferred embodiments of the invention.

In the drawings which illustrate the best modes presently contemplated for carrying out the invention:

FIG. 1 is a view, in cross-section, of a receiver, pursuant to the present invention, for a metal extrude'r;

FIG. 2. is a cross-sectional view of a receiver for metal extrusion presses similar to that of FIG. 1 but somewhat modified; and

PIG. 3 is a view similar to that of FIG. 1, of another embodiment of the invention.

Pursuant to the present invention, it was found that the heating or cooling provisions for the receiver must be `effective not only in or on the receiver jacket, but that the inner sleeve itself must be directly heated or cooled, 'as required. The problem resulting from this finding consists part-icularly in providing the conditions whereby cooling or heating channels can be arranged without danger within an inner sleeve. The solution of this problem, pursuant to the present invention, is Vachieved by the radial subdivision of the inner sleeve, in known manner, into sectors and in the provision in these sectors of channels for heating or cooling media. Provision is made for the known longitudinal division of an inner sleeve to avoid dangerous tangential stresses. The present invention utilizes the division of the inner sleeve and the reduction of its stress in order to work channels into the sectors. The cross-sectional reduction of these segments by the channels is now irrelevant since the sectors are substantially only under compressive Stress.

.The production of longitudinal bores in the material used for the inner sleeve frequently presents difficulties.

According to another aspect of the present invention, the channels are formed as grooves in the abutting faces of the sectors and this can be done in a simple -manner by milling or planing. The grooves of the adjoining sectors cooperate to form a channel for the cooling or heating media.

Pursuant to a further aspect of the present invention, grooves or channels are provided in those circumferential surfaces of the sectors which abut the jacket and an intermediate sleeve, respectively.

The combination of longitudinal division of the inner sleeve and the channels formed therein, especially those at the abutting faces of the sectors, that is, close to the receiver Chamber, perrnits for a far better supply and discharge of heat and thus prevents the high stresses which are particularly harmful to the life of the receiver materials and which are caused by the unavoidable high temperature gradient. Additional conventional heating and cooling methods can also be used. The greater the number of individual sectors provided within a sleeve, the greater the effectiveness of the Channels produced between the abutting faces of the sectors.

In view of the tangential stresses in the sectors, which are still possible despite the thus attained division of the inner sleeve, and the resulting danger of a rupture, it is preferable to provide a minimum of four sectors.

As previously indicated, receivers provided with channels have been heated with electric heating cartridges inserted into the Channels, as far as the heating to the final Operating temperature is concerned. Since, according to the present invention, a large number of Channels are provided where the receiver must be first heated, that is, immediately adjacent to the receiver bore or Chamber, the Channels in the inner sleeve are supplied selectively or alternately, with a liquid or gaseous Cooling agent, or as a substitute for the present methods of heating to Operating temperature, with a liquid or gaseous heating agent. As a gaseous medium can be used with great advantage, saturated steam may be employed for Cooling and superheated steam may be used for heating. Due to the large number of Channels that are available, it is possible also to connect certain of the Channels, for example every second channel, to a Cooling medium source, and all the other Channels to a heating medium source. Heating cartridges of known type can be inserted in the Channels of the inner sleeve and can now be made ready for the receiver in a shorter time than before.

The foregoing prerequisite is also met, for example, when a salt bath solution is used as a heating medium. A salt bath solution has a very high boiling point, and during the heating it is necessary only to see to it, by suitable selection of the fiow Velocity, that the exit temperature is above the solidification temperature of the solution.

Such a liquid, for example a salt bath solution, can be used pursuant to the invention for heating as well as for Cooling, if it is either heated or cooled before it enters the receiver Channels.

The effect that these liquids cannot evaporate, neither during the warming-up process before the heating nor in the heat absorption by the Cooling of the receiver, results in a surprising simplification of the Cooling and heating problem, particularly When the Channels are provided in the inner sleeve of the receiver.

The effects of the present invention regarding a better control of the temperature Course inside a receiver are not without influence on the selection of the material for the inner sleeve and for the receiver jacket and also for an intermediate sleeve where the latter is required. The inner sleeve must still be heat resistant and wear resistant. However, because of the longitudina'l division, said inner sleeve is subjected to lower tensile stress which permits use of harder construction material. Since the uniform temperature course eliminates the alternate stresses that previously appeared, the receiver jacket can now also have a lower tensile strength and tenacity. Consequently, it is within the scope of the present invention, in connection With the division of the inner sleeve into individual sectors, to provide those faces of the sectors, which define the receiving Chamber, with a material of a higher wear resistance Character than that of the sleeve material, said high wear resistance material being applied by built-up welding.

While it is well known in the mechanical engineering art to select a low-grade material for parts that are subject to wear and to improve the stressed surface thereof by built-up welding, the present state of technology in this area discloses that in a radial division of the receiver sleeve, which has proven to be particularly advantageous for the material requirements, it was found to be essential to require high wearresistance, as heretofore.

Referring now to the drawings in detail, FIG. l illustrates the presently preferred embodiment of the in'vention. There is shown a receiver or billet container assembly w for a metal extruder. The receiver Comprises a jacket I provided with an inner sleeve or sleeve assembly 11. As here shown the sleeve lll, which is shrunlt-fit into the jacket, is divided radially into twelve sectors or segments 3. lt is preferable that there be a minimum of four scgrnents. The abutting faces T2 of the various sectors are provided with grooves 5 and the adjacent grooves cooperate to form a Channel 13 between each pair of abutting sectors. Said Channels are each connected to a suitable Cooling medium or heating medium supply. For example, the heating Channels may be provided with electric heating Cartridges as indicated at 38. If required, the abutting faces 12 can be provided also with smaller grooves which cooperate to form Channels for receiving packing wires 7 of suitable, if desired, heat dissipating material. Packing elements '7 further Constitute fluid-tight connections between segments 3.

The inner faces 3b of the sectors 3 define an inner billet receiver Chamber' 8. When these faces are made wear resistant by built-up welding, the base material of the inner sleeve need not be wear resistant.

Referring now to PIG. 3 in detail, there is shown another embodiment of the present invention. As here shown, there is provided a receiver ltlA for a metal extruder, which receiver has a shrunk-fit inner sleeve 11A, a jacket 1 and a shrunk-fit intermediate sleeve 2 between the inner sleeve and the jacket. As here shown, the inner sleeve is divided into twelve sectors or segments 3A, it being preferable to provide a minimum of four segments. The abutting faces 12A of the segments are each provided With a plurality of grooves 5 defined therein which cooperate with adiaccnt grooves to define Channels 138, lid. In addition, grooves 4 are defined in the Circumferential faces 3f of the segments 3 which abut the intermediate sleeve 2. in addition, the segments are provided with bores which define the interior Channels 6. It will 'oe understood that the Channels 13a, 13a' and 6, and the grooves 4 all receive either heating or Cooling media.

The inner faces 31'; of the segments 3 define the receiver Chamber 8. As in the case of the receiver 1d, said faces may be made wear resistant by built-up welding so that the base material of the inner sleeve 11A need not be wear resistant.

In both the receivers 16) and 10A, where the inner faces 3b are made wear resistant by built-up welding so that the base material of the inner sleeve is not of a wear resistant type, the Cooling Channels in the segments 3 or 3A can be eliminated since the requirement of high heat resistance is easier to meet if the base material of the segments need not be wear resistant.

In the embodiment of FlG. 1 the Channels 13, and in the ernbodirnent of FIG. 3, the Channels 130, 13a' and 6 and the grooves or Channels 4 Can be connected 'both to a Cooling medium source and to a heating medium source, either all together or separately and individually to different sources so that they can be traversed selectively or alternately by a liquid or gaseous Cooling agent or by a liquid or gaseous heating agent. The Cooling agent may be saturated steam and the heating agent may be superheated steam. The heating agent may also be a salt bath solution.

Referring to FIG. 2 there is disclosed a modification of FIG. 1, employing instead of one row of Channels 13 two rows of Channels 13a, 13b located at the radially extending Valbutting faces of seotions 3B, the latter being otherwise shaped in `accordance With FIG. 1. As in the embodiment of PIG. 1 Centering or packing wires 7 are used to maintain vthe sections 3B in predetermined and centered position about receiver Chamber 8. The aforesaid receiver is particularly useful for metal extrusion presses. T'he one row of Channels .1`3b may be employed as passageways for a Cooling medium 27, the

other row of Channels 13a for passing therethrough a heating medium 28.

The receiver according to FIG. 2 has aiso been found to be suitable for the treatment of steel ingots, whereby by means of the heating medium which fiows through the innermost row of Channels, the receiver parts are brought up to operational temperature prior to the start of the press operation.

Only during the operation of the press excessively high stored heat in the receiver body may be reduced and dissipated through a Cooling medium which circulates in the innermost Channels. 'It should be appreciated that the Cooling and heating media may be directed into other Channels, if desired.

As stated before, as a Cooling medium saturated vapor or steam or, if desired, a conventional Cooling liquid may 'be employed and it is further contemplated by this invention to use in one and the same channel system (interconnected or not) a salt bath solution which is so composed that it does not evaporate above 1000 C. and does not solidify at 'about l50 C.

It can thus be seen that there has been provided according to the invention lmethod and means for operating a receiver for extrusion presses and similar power driven machines, said receiver comprising a receiver jacket, an inner sleeve shrunk-fit Within said jacket, said sleeve being divided radially into a plurality of faceabutting segments, channel means defined by said segments and adapted to ccnduct means for controlling the temperature of said jacket and said sleeve, said segments terminating in outer faces which define an inner receiver Chamber, said outer faces being provided with a material having a higher wear resistance characteristic than the material of which the segments are formed, said higher wear resistance material being provided on said faces .by built-up welding.

Various changes land modifications may be made without departing from the spirit and scope of the present invention and it is intended that such obvious changes and modifications be embraced by the annexed claims.

ZHaving thus described the invention, what is claimed as new and desired to Ibe |seoured by Letters Patent is:

A billet container assembly for use with a female extrusion die; an extrusion ram, and ancillary apparatus Comprising: an outer jacket having a ci-rcular cylindrical vbore therethrough; an inner sleeve assembly the outside surface of which is complementary to and mates with and is Shrink fitted in said bore, said sleeve assembly having an inner billet receiving Chamber uniformly formed so that said rain Can slide therealong to apply the requisi'te pressure to the Contained billet to eXtrude the same through the appropriately mounted said die, the portion of said sleeve assembly immediately adjacent 'said Chamber being of a material of higher wear resistance than that of the balance of said sleeve assembly, said sleeve assembly being divided into a plurality of segments by planes which if extended pass through the billet containeris longitudinal axis, each pair of abutting segment faces having four Channels formed by four pairs of lrespectively mating grooves extending parallel to said axis with four of said grooves in one of said faces and the other four of said grooves in the abutting other face, the innermost and outermost of said Channels being packing wire Channels, one of the remaining Channels being for a heating medium, and the solely remaining channel being for a Cooling medium; packing wires, one yassembled in each of said packing Wire channels.

References Cited in the file of this patent UNITED STATES PATENTS 900,401 Loomis Oct. 6, 1908 1,715,936 Madden June 4, 1929 2,283,791 Clark May 19, 1942 2,792,482 Logan et al May 14, 1957 FOREIGN PATENTS 747,477 Great Britain Apr. 4, 1956 783,863 Great Britain Oct. 2, 1957 855,479 France Feb. 12, 1940