Патент USA US2105150код для вставки
Patented Jan. 11, 1938 2,105,150 ‘ UNITED STATES PATENT OFFICE 2,105,150 , TUBE PUSH BENCH Kai-01y Korbuly, Csepel, Hungary, assignor to the ?rm Tube Industrial Participation Limited, Breganzona-Lugano, a corporation of Switzer- ' land Application January 21, 1937, Serial No. 121,677 1 ' Germany June 29, 1936 2 Claims. (01. 80-12): This invention relates to push bench drawing at least the last third part of the total length of ' the whole series of passes and is acted on at one time by not less than one third of the total num ber of passes. apparatus for the manufacture of metal espe cially iron or steel tubes of the kind by which a heated somewhat thick cup-shaped hollow billet carried on an end of a mandrel is pushed through. Preferably the passes are disposed at such dis tances apart that the partially formed tube when it enters the smallest roll pass .extends at least through-passes between rolls which passes de crease successively in cross-sectional area in a3 forward direction and which rolls are not driven, whereby the billet is reduced in thickness and 10 spread out lengthwise along the mandrel until the billet is brought to the form of a tube of the required thickness and length. In the operation of push bench apparatus in ' which ring dies are employed instead of through 15 passes between rolls, if the resulting tube is to be at least ten times the length of the billet treated and the drawing is‘ to be effected in one opera tion, the ring bed must be of a length to permit the spacing of the dies at such distances that the 20 tube being drawn engages at most four, and in exceptional cases perhaps ?ve dies simultane ously, when the head end of the tube enters the last orsmallest die, while in the major part of the ring bed it is acted on only by two or three dies over the second half of the total length of the whole series of‘passes and is worked on simul taneously by not less than half of the total num ber of passes. The total length of the series of passes may be even less than the ?nal length of the drawn tube, whereby the length of stroke re quired for the push bench can be less than twice the length of the tube to be produced. ' The trough diameter of the rolls of a pass, that 15 is, the diameter of the rolls measured at the bot‘ tom of the circumferential groove is, preferably, in the first or largest pass such that it does not exceed the pass diameter by more than 20%, while the trough diameter of the rolls of any 20' other pass is smaller than the trough diameter of the rolls of the largest pass. The trough di ameters of the rolls in a pass must be so chosen 25 simulv neously. In order to avoid a rupture ofv as to have a relation to the pass diameter of the the metal during the lengthening of the billet to respective pass such that the ratio of thetrough more than ten times its original length a total co number of dies exceeding 20 must be employed. The partly formed tube on entering the last or smallest die will thus be acted on simultaneously by less than one fourth, and generally by less than one ?fth, of the total number of dies which are distributed along a shorter distance than the last quarter of the total length of the ring die bed, which has to be more than twice the length of the tube produced. The long stroke ‘required not only results in slower working, but in conjunction with the cooling effect of the mandrel would cause 25 diameter to the pass diameter in the several passes decreases gradually from the last pass towards the ?rst pass. One form of push bench drawing apparatus according to the present invention will now‘ be 80 described by way of example and with reference to the accompanying partly diagrammatic draw ing wherein: Fig. 1 is a diagrammatic elevation of the push bench, 85 Fig. 2 shows to a larger scale and diagrammati- ' cally the partly formed tube at the point at which the metal to cool so quickly that di?iculty would _ it enters the smallest roll pass and Fig. 3 shows-a front elevation of a roll pass for the heating e?ect produced by the friction 40 be experienced in drawing the tube were it not between the dies and the tube. This, however, means that considerable power is required to push the tube through the dies. 45 in is an object of the present invention to pro~ vide apparatus of the kind described by which these disadvantages are overcome. According to the present invention in push bench drawing apparatus of the kind described 50 the number of roll passes is greater than the ?g having three rolls arranged at 120°. 40 Referring ?rst to Fig. 3 r are the rolls which are loosely journalled in a ‘carrier or housing s. The rolls are. arranged at 120° and form a pass of whichD is the pass diameter. d is the trough diameter or diameter of the rolls measured at 45 the bottom of the groove 9. While the pass illustrated in Fig. 3 has three rolls it will be understood that according to requirements two rolls or more than three rolls may be employed. at ure indicating the relation between the length of ' , Referring now to Fig 1 the push bench is in the drawn tube and the original length of the ‘ tended to stretch the billet b shown by ‘dotted billet, and said passes are disposed at such dis tances apart that the partiallyfor‘med tube when lines from its length L to for example the length 55 it enters the last and smallest pass extends over 13L, for which purpose more than thirteen passes, for example seventeen passes a1—arz, arewar- 55 2,105,150 2 ranged coaxially along the bench. The heated billet I) carried on the end of the mandrel m is pushed through the series of passes and after it emerges from the last pass a“ it will have a length of, for example, 13L as indicated by the ' dot and dash line at the left hand end of the ?gure. The trough diameter d1’I of the rolls of the smallest and last pass a" is, for example 1.3 times the pass diameter D of this pass, while 10 the trough diameter d1 of the ?rst and largest pass a1 is equal to the pass diameter of this said ?rst pass. Hence, the ratio d D 15 decreases gradually from the smallest and last pass a" towards the ?rst and largest pass al. The partially drawn tube w is indicated in Fig. 1 in full lines and it is at the stage when it is entering the smallest pass a". At this 20 stage the partially formed tube extends over a length of 6.7 L, that is to say over a length which is larger than half of the total length 11L of the pass bed. At this stage also the tube is 25 acted on simultaneously by eleven passes aL-a" at one time. Fig. 2 shows the partly drawn tube at this stage and to a larger scale. The total number of passes in the push bench illustrated being seventeen the number of passes acting on the tube at this stage, namely, eleven, is substan tially greater than one third of the total num ber of passes and is even greater than half the total number of passes. . The total number of passes (ll-a" in the ap paratus illustrated diagrammatically in Fig. 1 extends over a length which is about equal to 11L, that is to say, the total length of the passes is less than the length of the tube produced which is indicated in Fig. 1 as being 13L. What I claim is:— ' 1. A push bench drawing apparatus for pro ducing a tube from a hollow billet, the length of which tube is at least ten times the length of the hollow billet, comprising a mandrel and roll passes, in which the rolls are idle, disposed in front of the mandrel, the number of said passes being greater than the ?gure indicating the re lation between the length of the drawn tube and the original length of billet, said passes being disposed at such distances apart and decreas ing successively in cross-sectional area in for ward direction in such stages that the tube on entering the last and smallest pass reaches a length which extends at least to the last third of the total length of the whole series of passes and is acted on simultaneously by not less than 20 one-third of the total number of passes. 2. A push bench drawing apparatus for pro ducing a tube from a hollow billet, the length of which tube is at least ten times the length of the hollow billet, comprising a mandrel and roll passes, in which the rolls are idle, disposed in front of the mandrel, the number of said passes being greater than the ?gure indicating the relation between the length of the drawn tube and the original length of billet, said passes being disposed at such distances apart and de- creasing successively in cross-sectional area in forward direction in such stages that the tube on entering the last and smallest pass reaches a length which extends at least to the second half of the total length of the whole series of passes and is acted on simultaneously by not less than one-half of the total number of passes. KARoLY KORBULY.