MXPA97004834A - Method for manufacturing parts with interior teeth - Google Patents

Abstract

The present invention relates to step rotation method for manufacturing parts with internal teeth, comprising: providing a pressure mandrel mounted in a mounting location of the mandrel, provided at a first end of the mandrel, in a machine for rotation of the mandrel about an axis of the machine extending longitudinally, providing a tool for setting mounted on or adjacent to a second end of the mandrel, opposite the first end, providing one or more pressure rolls spaced apart from the circumference of the tool for configure, provide a work piece between the tool to configure and the one or more pressure rolls, rotate the mandrel and apply a force to the work piece by means of one or more pressure rolls, of which the work piece is deformed pl sticamnete by the application of force, where a distacia of the tool to configure, from the mounting location d the pressure mandrel is sufficiently long that the tool to be configured can withstand a degree of deflection (a) with respect to the machine axis, so that the tool to be configured can automatically center itself under the pressure of one or more rollers of pressure applied uniformly around the circumference of the tool to configure by the deflection of the mandr

Description

Method for the Manufacture of Parts with Internal Teeth The invention relates to a method for manufacturing parts with internal teeth according to the preamble of claim 1. DE-A1-24 20 014 describes a cylindrical return method, according to the species that a tubular workpiece to a rotary extrusion process. Plastic deformation and / or softening of the tip of the material occurs. This method is basically different from the rolling, hammering or deep stretching, since in this case only the work hardening of the material occurs. In the step rotation method described, the workpiece is located on a rotatingly operated pressure mandrel with one or more pressure rollers on which the workpiece rests during longitudinal movement. The pitch formation of the metal occurs between the pressure mandrel and / or the forming tool and the pressure roller (s), with the reduction of the thickness of the wall of the work piece and the increase of its length. The object of the invention is to improve the method according to the preamble in Claim 1 sufficient to guarantee mass production.

According to the invention, this objective is achieved by the characteristic aspects of claim 1. The fact is that the distance of the forming tool from the point at which the pressure mandrel is mounted on the machine is so great that the The forming tool can exceed a certain degree of deflection relative to the axis of the machine by ensuring that the forming tool can center itself by deflecting the mandrel under the pressure of the roller as it engages the circumference uniformly. The automatic centering of the mandrel (and therefore of the forming tool) results in reliable manufacturing without the constant breaking of the tool caused by the stress imposed by the pressure of the outermost roller. The forming tool according to the invention consists of materials containing chromium and molybdenum (for example in accordance with DIN 1.2343, 1.2344 and 1.2606) and is blown and tempered and also have a cured surface. Preferably, then it is polished. As a result of these measures, the training tool is extremely durable and suitable for continuous use. The distance of the forming tool from the mounted location of the mandrel is preferably 200 mm or more, preferably 500 mm. These course dimensions depend on the stability and size of the machine. In any case, insurance must be provided in the training tool that passes a certain degree of deflection. The pressure rollers are preferably made of HSS steel or a hard metal. Additionally, the seating angle of the pressure roller or pressure rollers, in a preferred embodiment, is between 5 and 45 °, the discharge angle is between 0 and 20 °, and the radius of the outermost roller is between 0.5 and 25 mm. Another aspect according to the invention provides that the workpiece is pushed towards the forming tool as a blank, the crucible shape, previously forged or twisted. As a result, the workpiece is firmly anchored in the training tool. With the aim that the pressure rollers grip the work piece improves, advantageously, a constriction or decrease is provided on the outer face of the work piece, the depth of the constriction is 0.2-0.6 x S, where S is the thickness of the wall of the workpiece. Advantageously, the constriction is combined with the outermost circumferential surface of the workpiece at a maximum angle d of 45 °. In a preferred version, the step rotation can also be carried out by the opposite rotation method. The guided mobile head on the machine is placed so that it attaches to the training tool, so that the mandrel, the forming tool and the moving head constitute a unit. Then, the workpiece is clamped like a crucible-shaped blank between the forming tool and the mandrel. In another preferred embodiment, to produce the parts with internal teeth on both sides, a combination of the synchronized rotation method and the opposite rotation method is used, with a blank in the form of a double-sided crucible that is placed between the two forming tools such as a workpiece, a pressing roller adjacent to the moving head in the opposite turning method is advanced from the end of the blank towards the center and the pressing roller adjacent to the mandrel is advanced from the middle of the blank in the direction of the mandrel in the synchronous rotation method. Advantageously, the work piece in the form of a double-sided crucible, as a blank, has a constriction or decrease in the side directed towards the center, this constriction makes the transition makes the transition from the outermost circumferential surface of the workpiece. work at a maximum angle of 20 ° and has a depth of 0.2-0.6 x S, where S is the thickness of the wall of the workpiece. A further aspect of the invention will follow the figures described below.

Figure 1 shows a pressure mandrel with a workpiece placed on the rollers applied in a synchronous rotating method; Figure 2 shows a pressure mandrel with a spiral-shaped tooth forming tool; Figure 3 shows an arrangement for the pitch rotation using the opposite spin method; Figure 4 is an arrangement for the step rotation of a work piece with double-sided teeth; Figure 5 shows a cutting training tool; Figure 6 shows a pressure roller in section; Figure 7 shows a workpiece in the form of a crucible as a blank in section; and Figure 8 shows a work piece in the form of a double crucible as a raw workpiece in section. Figure 1 shows, schematically, a portion of the pressure mandrel 10 consisting of a mandrel 1 with a forming tool 2 mounted on the end. The positioning of the pressure mandrel 10 in the machine is not shown. The forming tool 2 is not rotatably mounted on a longitudinal extension 11 of the mandrel 1. Figure 5 shows an embodiment of the forming tool 2 in section. The longitudinal teeth, grooves or channels are placed on the surface of the forming tool 2, and represent the negative of the teeth that are produced. The crucible-shaped workpiece 4 is pushed into the work tool 2 (see Figure 1). The pressure rollers 3 engage the work piece 4 externally, with the result that the formation of metal passage of the work piece 4 occurs under the influence of the force of the pressure rollers 3. The thickness of the wall of the work piece is reduced and its length increases simultaneously. Here the synchronous rotation method is shown. According to the invention, the distance of the forming tool 2 from the mounted positioning of the pressure mandrel 10 on the machine is not shown, it is made sufficiently long so that the tool 2 can pass a certain degree of deflection relative to the axis of the machine 5. As a result, the forming tool 2 can be self-centering between the pressure rollers 3. For this reason, the distance of the tool of form 2 from the mounted mounting should be 200 mm or more and preferably 500 mm. To make the forming tool 2 more durable, it is manufactured according to the invention with materials containing chromium and molybdenum and which are blown and tempered as well as hard surface. Figure 2 shows an embodiment of a pressure mandrel 10 with a spiral teeth forming tool 2 and the work piece 4 mounted in position, the work piece is pressed directly by the pressure roller 3 against the tool 2. During forming of the parts with the spiral teeth, the forming tool 2, in particular, is subjected to tension by the axial passage material until the teeth break. By the corresponding selection of the formation parameters such as, for example, feed of the pressure roller, the degree of reduction, the geometry of the roller and the speed of rotation of the machine, the tendency of the material to be twisted as it is formed is used. As a result, the force in the forming tool 2 is released and this results in a longer service life. By forming the work piece with the use of the step rotation method, a significant hardening of the material is obtained. This hardening can be influenced by an appropriate selection of the degree of formation and the geometry of the tool. As a result, the subsequent blowing and hardening and hardening of the parts with internal teeth is unnecessary. The hardening of the workpiece as well as the hardening of the surface by the known nitriding methods guarantees the desired hardness and wear resistance of the parts.

Figure 3 shows a step rotation using the opposite spin method. In this case, the movable head 9 guided in the machine is located adjacent to the forming tool 2, with the mandrel 1, the forming tool 2 and the moving head 9 forming a unit. The workpiece 4 is fastened with a clamp as a crude workpiece in the form of a crucible between the forming tool 2 and the mandrel 1 or the clamping element 12. The pressure roller or the pressure rollers 3 engage the end of the workpiece 4 that faces the movable head 9 and moves from this position in the direction of the mandrel 1. Figure 4 shows the manufacture of a part with internal teeth on a double side using a combination of the turning method without chronic and the opposite spin method. The two forming tools 2a, 2b are located between the movable head 9 and the mandrel 1, with a double-sided crucible-shaped workpiece 4 'which is placed between the forming tools 2a, 2b. This workpiece 4 'is described in more detail in Figure 8. The step rotation using the synchronous rotation method is carried out by the pressure roller 3b moving from the middle of the workpiece 4' towards the mandrel 1. The opposite rotation method uses a pressure roller 3a adjacent to the guide head 9 which moves from the end of the workpiece 4 'towards the middle part.

Figure 6 shows a cut through the pressure roller 3. This roller has an internal central part with a slot 13 for anchoring. According to the invention, advantageously, the pressure rollers 3 are made of HSS steel or of a hard metal. The rolling angle ß of the pressure roller 3 is advantageously between 5 and 45 °, the discharge angle? it is between 0 and 20 °, and the radius of the outermost roller r is between 0.5 and 25 mm. Advantageously, the thickness of the roller B is between 60 and 260 mm and the width of the roller D is between 20 and 90 mm. As mentioned above, it is an advantage that the workpiece 4, 4 'is pushed into the work tool 2 as a previously forged or twisted blank. Figure 7 shows a work piece 4 which is advantageously used in the synchronous rotation method. Figure 1 shows a corresponding arrangement. The workpiece in the form of crucible 4 has a constriction or decrease 7 at the outermost end 6, the depth of the constriction is a = 0.2-0.6 x S, where S is the thickness of the wall of the workpiece 4 as a blank. The constriction 7 makes a transition at a maximum angle d of 45 ° towards the outermost circumferential surface of the work piece 4. This constriction 7 allows a better engagement of the pressure rollers 3. In Figure 8 a part of the work in the form of double crucible 8 in cut as a blank. This work piece 4 'is used in the device described in Figure 4. The work piece 4' has a constriction 7 'on one side directed towards the middle part, this constriction makes the transition with the outermost circumferential surface B of the workpiece 4 with a maximum angle s of 20 ° and a depth of 0.2 to 0.6 x S, where S is the thickness of the wall of the workpiece 4 'as a blank. This constriction 7 'is provided to better engage the pressure rollers 3b in Figure 4.

Claims (10)

1. Claims 1. The step rotation method for manufacturing parts with internal teeth, using a pressure mandrel (10) consisting of a mandrel (1) with a forming tool (4) located between the forming tool (2) or the pressure mandrel 810) and the pressure rollers (3), the workpiece It is plastically deformed by the application of force by the pressure roller (3), characterized in that - the distance of the training tool (2) Since the mounted mounting of the pressure mandrel (10) on the machine is so large that the training tool (2) may exceed a certain degree of deflection (a) with respect to the axis of the machine (5); and - the forming tool 82) consists of materials containing chromium and molybdenum and is blown and tempered as the surface hardens. The step rotation method according to claim 1, characterized in that the distance of the forming tool 82) from the mounted location of the pressure mandrel (10) is 200 mm or more and preferably 500 mm. 3. The step rotation method according to claim 1 or 2, characterized in that the pressure rollers 83) are made of HSS steel or a hard metal. 4. The step rotation method according to one of claims 1 or 2, characterized in that the rolling angle (ß) of the pressure roller or roller (3) is between 5 t 45 °, the discharge angle (? ) is between 0 and 20 ° and the radius of the outermost roller (r) is between 0.5 and 25 mm. The step rotation method according to one of the claims 1 to 4, characterized in that the workpiece (4) is pushed into the forming tool (2) as a blank in the form of a blank. previously forged or crooked crucible. The step rotation method according to claim 5, characterized in that a constriction (7) is provided at the outermost end (6) of the workpiece (4), the depth (a) of the constriction is 0.2 - 0.6 x S where S is the thickness of the wall of the workpiece (4). The step rotation method according to claim 6, characterized in that the constriction (7) makes a transition towards the outermost circumferential surface (8) of the workpiece (4) at a maximum angle (d) ) of 45 °. 8. The method of step rotation according to one of claims 1 to 7, characterized in that the step rotation is carried out using the opposite rotation method, with a moving head (9) guided in the machine that is placed adjacent to the training tool (2) and the mandrel (1), the forming tool (2) and the moving head (9) forming a unit, and a workpiece (4) that is clamped like a blank between the forming tool 82) and the mandrel (1). The step rotation method according to one of the preceding claims, characterized in that a combination of the synchronous rotation method and the opposite rotation method is used to manufacture internally toothed portions with internal double-sided teeth, that two forming tools (2a, 2b) are placed between a moving head (9) and the mandrel (1), that the double-sided crucible-shaped workpiece (4 ') is placed between the forming tools ( 2a, 2b), that the pressure roller (3a) adjacent to the moving head (9) is advanced in the opposite rotation method from the end of the workpiece (4 ') towards the middle part and - that the pressure roller (3b) adjacent to the mandrel 81) advances in the method of synchronous rotation from the middle part of the workpiece (4 ') towards the mandrel (1). The method according to claim 9, characterized in that the workpiece in the form of double-sided crucible 84 ') as a blank has constrictions (7') directed towards the middle part of one side, the constriction makes the transition to the outermost circumferential surface (8) of the workpiece (4 ') at a maximum angle s of 20 ° and having a depth (a) of 0.2-0.6 x S, where S is the thickness of the wall of the work piece (4 ').