US2053975A

US2053975A - Method of forging

Info

Publication number: US2053975A
Application number: US534747A
Authority: US
Inventors: Spatta George
Original assignee: Clark Equipment Co
Current assignee: Doosan Bobcat North America Inc
Priority date: 1930-02-21
Filing date: 1931-05-04
Publication date: 1936-09-08
Anticipated expiration: 1953-09-08

Description

Sept. 8, 1936. s. sPATTA 2,053,975

` METHOD OF FORGING voriginal Filed Feb. 21, 195o y Y y Patented Sept. 8, 1936 UNITED STATES PATENT oFFlc METHOD or rename George Spatta, Buchanan, Mich., assignor to Clark Equipment Company. Buchanan, Mich., a corporation of Michigan 9Claiml.

'I'his invention relates to a method of forging a heated tubular blank by a series of endwise upsetting operations which thicken the walls of the blank and stretch them to form a collar of cylindrical shape and having internal and external diameters greater than the internal and external diameters respectively of the blank. The operations also form a planar flange of the free end of this collar and in a plane normal to the axis of the blank. The operations thus performed may conveniently be used as a step in the process of forming an axle housing such as is set out in my. co-pending application Serial No. 416,537, filed December 26, 1929, issued as Patent No. 1,926,353 on Sept. 12, 1933, although the method herein disclosed is not to be specically limited to this purpose.

In my co-pending application, Serial No. 430,206, led February 21, 1930, (Case 22), issued as Patent No. 2,027,406 on January 14, 1936, of which application the instant case is a division, I disclose a machine capable of performing the forging method herein set forth. While the use of a machine of the type disclosed in the parent application is preferable in the carrying out of the instant process, my improved method is not limited to such a machine and may, if desired, be performed by other mechanical arrangements.

My invention will be best understood by reference to the accompanying drawing in which a preferred embodiment of it is diagrammatically shown, and in whichz- Figure 1 is -an elevation view, partly in Sectio of a blank and forming punch and die used in the first step of my process;

n'Figure 2 is a similar view showing the work at in a suitable clampingmember which holds itl against longitudinal displacement with the heated end of the blank projecting into a stationary die member 3 of suitable design.

A punch carried on a suitable ram is aligned with the die 3 and adapted to be brought into reg- (Cl. 2li-15G) istration therewith. The punch has a shoulder 4 which engages the outermost end 5 of the heated blank, as the die advances axially of the heated blank, and collapses the metal of that end into the section of the blank that is disposed within the stationary die member. In Figure 1, the end section 5 of the blank is shown by a dash dot lines and these lines indicate the shape and size of the blank at the beginning of the first step in the instant process.

After the punch 2 has completed its travel into the die 3, the metal in the end section 5 of the blank has been forced inward radially of the blank to form a thickened wall section indicated generally at 6 in Figure 1. 'Ihe walls of the blank I have been broken away in this figure to better indicate the shape of this thickened wall section 6. It will be noted that the inside diameter of the thickened portion 6, which conforms to the outside diameter of the nose 1 of the punch, is materially less than the inside diameter of the original blank I, and that the outside diameter 8 of the section 6 is slightly greater than the outside diameter of the original blank. 'I'he larger diameter portion 8 is tapered into the outer surface of the blank wall I by a taper 9 located adjacent the innermost end of the thickened wall section 6.

Upon the completion of this operation, the blank is unclamped and moved to a second die into which the thickened wall section 6 is projected. This die also has a vcooperating punch adapted to register with it and is equipped with a shoulder I0 adapted to engage the extreme end I I of the thickened wall section 6 of the blank. In Figure 2 I have shown the blank at the completion of this second step in the present process. The die I2 is shaped so that when the punch I3 registers with it the thickened wall section 6 of the blank I is forced outward to form a flange I4 on the end of the blank. The nose I4' of the punch is of a diameter slightly greater than the internal diameterA of the section 6, so that simultaneously with the axial shortening of the tube by this operation, the walls of the section 6 are stretched outward radially at the axially outer end of the thickened portion Ii so that their inside diameter is increased. The die I2 also is shaped to increase the external diameter of the blank to form a collar I5 located adnt the hange Il. The thickness of the end man of the blank at the point of the hangs Il is obviously further increased by the operation of the tools in this second step of my process. It is to be noted that during the operation in the second set of dies. the metal of the inside of the thickened portion l. and'l at the axially inward part thereof, that is. the metal at the point la, is forced axially rearward or inward longitudinally of the blank. This produces a thickened.

portion tc on the inside of and immediately to the rear of tbe\previously thickened portion l. lhe thickness of the material of theblank adjacent the thickened hange Il is greatly'increased in that the outer diameter has been increased by the formation of the collar portion Il and the inner diameter has been decreased by the formation of the metal at the point Ic.

At the completion of this second step, the work is again unclamped and brought into registration with another die and rie-clamped in place in'that die. As will be seen in Figure 3. this die is provided with a cooperating punch I6 which has a shoulder II which engages the free end I8 of the flange Il of the blank and with a tapered nose which spreads the walls of this section Il to increase their internal diameter. As the punch is brought into registration with the work, the metal in the hange I0 and in the sub collar I5 is forced outward radially into engagement with the die Il-to thereby form a cylindrical collar 20 whose external diameter is materially greater than the external diameter of the blank I and whose internal wall is tapered as at 2l to join it with the lthickened wall section 22 formed inwardly of the blank I by the nose of the punch. The punch also forms a flange 23 whose external diameter is materially larger than the external diameter of the collar 2l and whose parallel hat faces Il and 2l are disposed in planes normal to the axis of the blank I. It is to be noted that the metal for forming the thickened wall section I2 is obtained by pushing the metal 8c back axially of the blank, that is, in a direction parallel with the axis of the blank.

Upon the completion of this third step in the process, the blank is removed and its opposite end heated and that end then brought successively into engagement with the punches and dies herebefore described to form a similar collar and hange on that end;

As is well understood by those skilled in the art of forging, the maximum amount of metal how that can be made in one step is definitely limited. and if this amount is exceeded, the work is buckled or broken and is therefore defective. By proper design of the dies and punches used in the process, Il am able to move a maximum amount of metal by each step of the process without damage to the work. Obviously this reduces the number of separate steps necessary to fabricate the work and furthermore permits completion of the several steps of the process with one heating of the work, that is, during the interval during which it is cooling to a temperature too low for proper forging.

The method, while primarily intended as a step in the process of forming an axle housing set out in the teachings of my above mentioned co-pending application Serial No. 416,537, is obviously not limited to this general process and may be used for the Purpose of forming a flange upon the end of any tubular blank.

Having thus complied with the statutes and shown and described the preferred embodiment of my invention. what I consider new and desire tov have protected by Letten Patent is pointed out in the appended claims.

What is claimed is:-

l. The method of forging the end of a metal tube which comprises. thickening the end of the tube radially by forcing it inward axially. then forcing the thickened portion out radially and in axially at the axial outer portion of the thickened part and forcing the metal in axially at the axially innermost portion of the thickened part, to increase the thickness of the tube at a point spaced axially inward of the part hrst thickened.

then anling the axially outer portion of the thickened part of the tube and increasing both the thickness and the diameter of the portion -of the tube in back of the hange.

2. The method of forging the end of a metal tube which comprises, thickening the end of the tube radially by forcing the metal inward axially 20 and radially, then forcing the thickened portion out radially and in axially at the axial outer portion of the thickened part and forcing the metal in axially at the axially innermost portion of the thickened part, to increase the thickness of the tube at a point spaced axially inward of the part first thickened,y each of the forcing operations being along the entire periphery of the tube simultaneously, then forcing the end portion of the thickened part of the tube radially outward to form a hange. l

3. The method of forging the end of a metal tube which comprises, simultaneously forcing the metal along the entire periphery at the end of the tube outward radially to form a flange, and simultaneously forcing the metal on the outside of the tube axially rearwardly to thicken the tube rearwardly beyond the rear face of the hange.

4. The method of forging the end of a metal tube which comprises forcing the metal at the end of the tube outward radially by a series of operations to form a flange having front and rear faces, each of the operations forcing the metal simultaneously along the entire periphery of the end of the tube, and during the series of operations gathering metal along the outside of the tube rearwardly of the rear hange face to thicken the tube portion at the rear of the hange.

5. 'I'he method of forging the end of a metal tube which comprises. thickening the end of the tube by decreasing the internal radius of the tube. then forcing the metal at the end of the thickened part radially outward to form a hange with a thickened portion of the tube axially rearward of the flange, then flattening the hange axially to increase its radius, and forcing the metal outward axially back of the hange to increase the internal radius of the tube back of the hange while maintaining the thickness in excess of the original tube thickness.

6. The method of upsetting and hanging end of a tubular arm which comprises heating said end, subjecting said end while heated to a series of'endwlse upsetting operations comprising initially gathering metal to thicken said end, and subsequently haring and hanging said thickened end to produce a thickened radial flange joined to said arm by an enlarged thickened bearing seat portion.

'1. The method of upsetting and hanging the end of a tubular arm which comprises heating said end. successively subjecting said heated end to three endwise upsetting operations to form a thickened end expanded into a bearing seat, and a thickened radial ilange at the outer end of said y seat, and controlling the area of the die surfaces 9. The method of ilanging a tubular member which comprises subjecting said member to endwise upsetting to increase the wall thickness adjacent one end thereof, expanding the thickened portion radially, and forcing the end of said thickened portion outwardly to form a thickened radially extending ange joined to said member by a thickened bearing seat portion.

GEORGE sPA'i'rA. 1o