JP4307256B2 - Integrated joint body - Google Patents

Description

  The present invention relates to a sintered metal body having a ball raceway and / or a ball raceway curved portion arranged at an angle with respect to a pressing direction, in particular, a joint inner ring of an axial joint, a method for manufacturing the same, and the method. It is related with the apparatus for doing.

  A shaft joint comprising a joint inner ring and a joint outer ring is known. They are inter alia useful for transmitting torque between shafts that are subject to large displacements during operation. At that time, the axial displacement can be absorbed.

  One example of transmitting torque through shafts that are angled with each other is a constant velocity joint. Constant velocity shaft joints belong to the class of universal joints (Zapfengelenk), and the most common structure is a hook joint. In the hook-type joint, the joint yokes of both shafts are connected to the pins. A simple hook joint allows a substantially small angle change. Axial and radial sliding of the shaft is not possible.

  The constant velocity joint prevents these drawbacks. Unlike the hook joint, the constant velocity joint generates a uniform rotational speed on the output side at a uniform angular velocity. The same is true for torque.

  The deflection axis is composed of two joints and one intermediate shaft. The intermediate shaft is usually implemented as a telescopic shaft to compensate for the change in length. The condition for uniform transmission is that both joint yokes are in one plane, and if the deflection angle is always the same in both joint yokes, it is at least in the state that appears most frequently during operation. . This can be achieved by a Z configuration or a W configuration. The former is common in automobiles. At that time, irregularities appear only on the intermediate axis. Double joints are used to compensate for large angular movements in a small space, for example in the front-wheel drive of automobiles. This basically corresponds to the deflection axis, but instead of an intermediate shaft, only one short intermediate member-the shaft or sleeve-is provided, which means that the deflection angles of both joints are always the same. Have been guided. Longitudinal slidability is provided on the input shaft or the output shaft. In addition, constant velocity joints allow uniform friction-coupled transmission of torque or angular velocity, usually via the ball, which is guided in the ball trajectory so that it is always in the mirror symmetry plane of the joint. Yes. Centering is essential for large constant velocity joints. A constant velocity joint allows uniform transmission at large turning angles. The constant velocity joint is configured as a fixed joint or a sliding joint. The fixed joint fixes the drive shaft in the axial direction, and the sliding joint enables compensation when the shaft length changes by vertical sliding. .

  This type of shaft joint is connected to the shaft by a joint outer ring and a joint inner ring. The joint inner ring is guided in the joint outer ring via a ball. The ball moves in the ball raceway in the ball cage, and the ball raceway is integrally formed on the outer surface of the joint inner ring and the inner surface of the joint outer ring. Due to the geometric shape of the shaft joint, the recess for the ball raceway needs to be formed integrally by cutting.

  This manufacturing method generally requires expensive and precise cutting. As a disadvantage, the joint inner ring has to be manufactured on various processing machines in a number of work steps. So far, the joint inner ring has been formed from a forged material in the usual way. This is because undercuts or molded parts, such as ball tracks, could not be produced by any pressing method and therefore could not be pressed and sintered from metal powder to the final shape. This generally required additional operational steps to achieve undercutter shaping.

  An object of the present invention is to provide a method and an apparatus capable of easily and accurately producing a sintered metal body or a forged body, particularly a joint inner ring of a shaft joint.

  The present invention solves this problem with the features specified in the method claims, apparatus claims and product claims.

  According to the present invention, a method for producing a sintered metal or a forged body, in particular a joint inner ring having a ball raceway of an axial joint, the powder is filled into a filling cavity, the filling cavity comprising a die and Defined by at least one forming mandrel and a filling mandrel, a central mandrel and at least one lower and upper punch arranged facing each other, wherein the powder is placed between the upper punch and the lower punch by pressure within the filling cavity. A method is proposed in which pressure is applied to form a preform, which is extracted and sintered. The sintered metal powder is charged into the filling cavity. The forming mandrel is inserted into the filling mandrel, the part geometry is fixed by relative sliding between the tools, and then the powder is compressed by applying pressure to the upper and / or lower punches to form the preform Is done. The preform after completion of pressurization is extracted from the pressurizer and sintered after the upper punch and the molding mandrel are retracted. In order to achieve high density, it is desirable if the sintered body is reworked warm or cold after sintering. Coining operations are possible after sintering and / or forging to achieve slight tolerances and / or partial compression. For example, it is advantageous if the ball raceway of the joint inner ring is cold-rolled or selectively roll-formed after sintering forging.

  The sintered metallurgically manufactured member has the advantage that the entire body of the joint inner ring forms a high strength structure having excellent material properties and surface quality.

  In an advantageous configuration of the invention, for the filling operation, the filling mandrel is inserted into the filling position in the die, the central mandrel is inserted into the filling position in the die, the lower punch is held in the filling position, When the forming mandrel attached to the filling mandrel is inserted into the die, the forming mandrel pushes down the filling mandrel in the die, and at this time, the ball track is formed in the powder by the shape of the forming mandrel, and at the same time the upper punch is Inserted into the die until reaching the upper punch press position, the powder is compressed into a preform, the ball track is formed by the die geometry, and the lower punch is inserted until the lower punch end position, The powder is also compressed, and during the extraction operation, the upper punch and molding mandrel are extracted from the die and the central mandrel is pulled back from the preform.The outer contours of the joint inner ring and the ball hub are formed partly by the die itself and partly by a forming mandrel that moves in the pressurizing direction within the die. Depending on the geometry of the joint inner ring, at least two upper forming mandrels and two lower filling mandrels are provided, preferably three mandrels supported in the die so as to be slidable in the pressing direction. Yes.

  In a particularly advantageous configuration of the invention, the side of the filling mandrel facing the forming mandrel terminates flush with the upper surface of the die and the upper surface of the central mandrel in the filling position, and the forming mandrel contacts the upper surface of the filling mandrel in the pressing position. At the same time, a pressing force is applied to the upper punch, the upper punch is inserted into the die, and then the upper punch and the molding mandrel are withdrawn from the die. It is extracted from the die by the lower punch.

  In a preferred configuration of the present invention, the powder is pressed into a preform by pressure and heat.

  In a particularly desirable configuration of the invention, the die and at least one punch are heated during pressing.

  In a preferred configuration of the invention, the shape of the ball track is formed by a forming mandrel.

  In another desirable configuration of the invention, the shape of the ball track is formed by a forming mandrel and a die.

  In an advantageous configuration of the invention, the surface of the ball track is compressed after sintering. The compression of the surface to achieve high strength can be effected, for example, by roll forming, in which case it is advantageous if only a partial area of the ball raceway surface is compressed. It is desirable to compress at least the ball running surface of the ball raceway surface.

  In a particularly advantageous configuration of the invention, the surface of the ball track is compressed by at least one ball after sintering, which applies pressure perpendicular to the ball track surface.

  In another advantageous configuration of the invention, the ball compresses at least one partial region of the ball track at least once. It is desirable that the ball made of cemented carbide rolls on the surface to be compressed at least once, preferably a plurality of times, and the surface is progressively compressed and molded in this way.

  In an advantageous configuration of the invention, the sintered part is then forged, a sintered body with ball tracks is inserted on the central mandrel in the die, and a forging tool presses the sintered body to form an outer contour. Then, the sintered body is extracted.

  In another advantageous configuration of the invention, the sintered parts are coined after sintering or forging, a sintered body having ball tracks is inserted on the central mandrel in the die, and a coining tool is used to insert the sintered body. Pressurize to form the outer contour, and then the sintered body is extracted.

  Another solution of the problem is a device for producing a sintered metal body having a ball track, in particular a joint inner ring of a shaft joint, comprising a pressurizing device, the pressurizing device comprising at least one forming mandrel And at least one filling mandrel, one lower and upper punch and one central mandrel, which are attached to face the molding mandrel, which form a filling cavity and are radially surrounded by a die. Given by things. Such a pressure device is characterized by a simple work process. The pressing operation is inexpensive and time-saving, inter alia, compared to known cutting production. Thereby, it becomes possible to manufacture a large number of joint inner rings in a short time. A die surrounding the filling mandrel and the forming mandrel captures the applied pressure acting radially on the forming mandrel.

  In an advantageous configuration of the invention, there are provided each three forming mandrels and three filling mandrels attached to face each other, which are guided in the recesses of the die. The filling mandrel and the molding mandrel placed in the recess of the die and the die itself form the outer contour of the joint inner ring, but this outer contour cannot be produced by a normal pressurizing device because of its geometric shape.

  The problem is further solved by a metal sintered body having a ball raceway disposed on the outer peripheral surface, particularly a joint inner ring of a shaft joint, in which the sintered body is integrally formed. For reasons of the strength and life of the joint inner ring, it is advantageous to construct the joint inner ring as one piece rather than assembling from two members that can be easily manufactured, for example, by pressing techniques.

  In a preferred configuration of the invention, the ball trajectory is arranged at an angle with respect to the pressure axis and / or is curved with respect to the pressure axis. The inner ring of the joint is provided with an undercut, a recess and a profile, preferably with a ball track that is radially aligned and axially aligned with the joint body axis, i.e. also in the pressure direction. The ball raceway has a raceway bottom and a raceway side surface, and the joint inner race has a geometric shape that allows the joint inner race to be pressurized in the axial direction and taken out from the pressurizing device or the forging device.

  In another desirable configuration of the invention, the ball track is configured round.

  In an advantageous configuration of the invention, the ball trajectory is substantially elliptical. This configuration is particularly advantageous because the ball is placed on the ball track only at two points and only one contact line is produced on the ball track during rolling. This region is advantageously compressed as described above and optionally heat treated and / or surface treated.

  In a preferred configuration of the invention, the ball trajectory is configured as a polygon. This configuration of the ball track is similar to the substantially elliptical ball track in that the ball has only a small mounting surface on the ball track, so that the rolling resistance is reduced and in particular the Hertzian stress can be optimized. Provides benefits.

  In an advantageous configuration of the invention, the ball track has a high density in a partial region, in particular in the region of the ball running surface.

  In another advantageous configuration of the invention, the ball track is heat-treated in a partial region, in particular in the region of the ball running surface. Such a member has the advantage that the ball track has high strength. This member can heat-treat at least the area of the ball track, for example, by induction hardening and surface hardening.

  In a particularly advantageous configuration of the invention, the ball track is surface-treated in a partial region, in particular in the region of the ball running surface. In order to properly optimize the properties of the ball running surface, the surface can be treated, for example, by shot peening, plasma nitriding, soft nitriding, phosphating, cold and hot roll forming.

  The invention is illustrated in the drawing on the basis of an embodiment of a constant velocity joint.

  FIG. 1 shows a constant velocity joint 1. This has a joint outer ring 2 and a joint inner ring 3. The joint outer ring 2 is coupled to the shaft 4, and the joint inner ring 3 is coupled to the shaft 5. The shaft 4 and the shaft 5 form an input / output system. The joint inner ring 3 is received in the joint outer ring 2. The ball 6 is arranged in the ball track 7 between the joint outer ring 2 and the joint inner ring 3 so that the ball 6 is guided in the ball track 7 when the shafts 4 and 5 are bent with respect to each other. At that time, the ball compulsorily travels on the mirror image plane. In the illustrated embodiment, the bending angle is 0 °, and the ball lies in a plane perpendicular to the straight line formed by the axes of the axes 4 and 5. This arrangement has a lid ring 8, which holds the ball in the ball track. When the input shaft is rotated, the output shaft is transmitted with a uniform rotational speed and a uniform torque even when the output shaft is appropriately bent within a possible limit. The shaft joint 1 is sealed on the outside with a soft seal 18.

  The ball track 7 can be arranged in parallel or at an angle to the pressure axis (ball hub axis 20). Furthermore, the ball track 7 can be curved with respect to the pressure axis (ball hub axis 20). In addition, a ball track 7 curved in the radial direction is possible, and the ball track 7 includes a track bottom 12 and a track side surface 13.

  FIG. 2 is a perspective view of the pressure device 21 for the ball hub 3 (joint inner ring), in which the pressure device 21 is provided with three molding mandrels 22.1, 22.2, 22.3 facing each other. And mandrels 23.1, 23.2, 23.3. Further, a lower punch 24, an upper punch 25, and a center mandrel 26 are provided. The punches 24, 25 and the mandrels 22, 23, 26 are surrounded by a die 27 in the radial direction. A die 27 that surrounds the filling mandrel 23 and the forming mandrel 22 captures the applied pressure acting on the forming mandrel 22 in the radial direction.

  The molding mandrel 22 and the filling mandrel 23 attached to face the molding mandrel 22 are guided in the recesses 28.1 and 28.2 of the die 27. The filling mandrel 23 and the molding mandrel 22 arranged in the recesses 28.1, 28.2 of the die 27 and the die 27 itself form the outer contour of the joint inner ring 3, but this outer contour is due to its geometrical shape. It cannot be manufactured with a normal pressure device.

  FIG. 3 is a perspective view of the pressurizing device 21, and the molding mandrel 22 is inserted into the die 27. During the pressing operation, the molding mandrel 22 is inserted into the die 27, the molding mandrel 22 pushes down the filling mandrel 23 in the die 27, and the ball raceway 7 of the ball hub 3 is molded in the powder by the geometric shape of the molding mandrel 22. The

  FIG. 4 shows the pressing tool 21 in the filling position. For the filling operation, the filling mandrel 23 is inserted into the filling position in the die 27, the central mandrel 26 is inserted into the filling position in the die, and the lower punch 24 is held in the filling position. In the filling position, the sintered metal powder 29 is filled into a filling cavity 28, which is filled with a die 27 and three molding mandrels 22.1, 22.2, 22.3 and facing the filling mandrel 23. .1, 23.2, 23.3, a central mandrel 26 and lower and upper punches 24, 25. When in the filling position, the side of the filling mandrel 23 facing the forming mandrel 22 is at the same height as the upper surface 30 of the die 27 and the upper surface 31 of the central mandrel 26.

  The filling mandrel 23 and the molding mandrel 22 arranged in the recess 28 of the die 27 and the die 27 itself form the outer contour of the joint inner ring 3. This outer contour is formed by a normal pressurizing apparatus because of its geometrical shape. It cannot be manufactured.

  FIG. 5 shows the pressing tool 21 in the pressing position. The forming mandrel 22 is inserted until it reaches the filling mandrel 23, and the forming mandrel 22 pushes down the filling mandrel 23 in the die 27. At this time, the ball raceway 7 of the ball hub 3 is formed in the powder by the geometric shape of the forming mandrel 22. The At the same time, the upper punch 25 is inserted into the die 27 until the upper punch pressure position is reached, and thus the powder is compressed into a preform, and the ball track 7 is also formed by the geometry of the die 27. The lower punch 24 is inserted until the lower punch end position is reached, whereby the powder is also compressed. A die 27 surrounding the filling mandrel 23 and the forming mandrel 22 captures the applied pressure acting on the forming mandrel 22 in the radial direction. The parts geometry of the ball hub 3 is fixed as the tools slide relative to each other during the pressing operation.

  The sintered powder is advantageously pressed into a preform by using heat. For example, the die 27 and the at least one punch 24, 25 can be heated during pressing.

  FIG. 6 shows the pressing tool 21 in the extraction position. During the extraction operation, the upper punch 25 and the molding mandrel 22 are extracted from the die 27. The central mandrel 26 is pulled back from the preform 3. The preform 3 that has been pressed is extracted from the die by the lower punch 24. Next, the preform 3 is sintered.

  Advantageously, the preform 3 after pressing has been reworked warm or cold after sintering in order to achieve high density. Coining operations are possible after sintering and / or forging to achieve slight tolerances and / or partial compression. For example, it is advantageous if the ball raceway 7 of the joint inner ring 3 is cold-rolled or selectively roll-formed after sintering forging. It is advantageous if only a partial area of the ball raceway surface is compressed, in which case at least the running surface 16 of the ball 32 on the ball raceway surface must be compressed.

  For example, the surface of the ball track 7 is compressed by using a ball after sintering, the ball applies pressure perpendicular to the ball track surface, and the ball is at least once at least one partial region of the ball track 7. By compressing, the surface of the ball raceway can be compressed. However, it is advantageous if the ball, preferably made of cemented carbide, rolls several times on the surface to be compressed and thus the surface is progressively compressed.

  The sintered part 3 is then forged, the sintered body 3 having the ball tracks 7 is inserted onto the central mandrel 26 in the die 27, and the forging tool pressurizes the sintered body 3 to provide an outer contour. It is advantageous if it is shaped and then the sintered body is extracted.

  It is also advantageous that the sintered body 3 is coined after sintering or forging. For forging and coining, a tool having substantially the same structural style as the pressing tool 21 can be used.

  In particular, it is possible to forge a metallic material into the ball hub 3 with the forging tool.

  FIG. 7 shows the ball hub 3 in plan view. The ball hub 3 is integrally formed, so that the strength and life of the ball hub 3 are high. The ball track 7 is disposed at an angle with respect to the pressure axis (ball hub axis 20). Each ball hub 3 has a ball track 7 attached to each other in pairs. The ball tracks 7 are axially aligned in the drawing plane and have a radial curvature 14. In each ball track 7 attached to each other in a pair, the curved portions 14 are opposed to each other, that is, the ball tracks 7 are close to each other in the axial direction. The ball hub axis 20 passes through the center of the ball hub 3 perpendicular to the drawing plane.

  FIG. 8 shows the ball hub 3 along the section AA in FIG.

  FIG. 9 shows the ball track 7 and the ball 32 in cross section. The ball 32 has a round geometric shape. The ball track 7 has a substantially elliptical geometric shape. The ball 32 travels on the travel surface 16, 16 'and has two contact points 17, 17' on the ball track 7 at each moment. Each contact point 17, 17 'is on a different track side surface 13, 13'. The contact points 17, 17 'are separated from each other at an angle 2δ from the ball center. This configuration is particularly advantageous because the ball 32 is placed on the ball track 7 only at two points, and only one contact line is generated on the ball track 7 during rolling. Since the ball 32 has only a small mounting surface on the ball track 7, the rolling resistance is lowered. The curvature of the ball 32 and the ball track 7 are optimized so that the Hertzian stress is minimized. This region is advantageously compressed and optionally heat treated and / or surface treated. Possible methods include, for example, induction hardening, surface hardening, shot peening, plasma nitriding, soft nitriding, phosphating, cold and hot roll forming.

It is sectional drawing of a constant velocity shaft joint. It is a perspective view of the pressure tool for ball hubs. It is sectional drawing of the pressurization tool which inserted the mandrel. It is sectional drawing of the pressurization tool in a filling position. It is sectional drawing of the pressurization tool in a pressurization position. It is sectional drawing of the pressurization tool in an extraction position. It is a top view of a ball hub. FIG. 8 is a cross-sectional view of the ball hub taken along line AA in FIG. 7. It is a cross-sectional view of a ball track and a ball.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 axis | shaft joint 2 joint outer ring | wheel 3 joint inner ring | wheel, a ball hub, a preformed body, the sintered part, the sintered body 4, 5 axis | shaft 6 ball | bowl 7 ball track 8 lid wheel 12 track bottom 13 track side surface 16 running surface 17 contact surface 18 Soft seal 20 Ball hub axis 21 Pressure device 22 Molding mandrel 23 Filling mandrel 24 Lower punch 25 Upper punch 26 Center mandrel 27 Die 28 Filling cavity 29 Sintered powder 30 Upper surface of die 31 Upper surface of center mandrel 32 Ball

Claims (13)

A joint inner ring (3) having a ball raceway (7) of a constant velocity shaft joint (1) in which a ball (6) is arranged between the joint outer ring (2) and a joint inner ring (3) received inside thereof ; A method for manufacturing
A central mandrel (26) extending in the vertical direction, a lower punch (24) fitted over the central mandrel (26), and a recess (28.1 on the inner peripheral surface surrounding the central mandrel (26) and the lower punch (24). , 28.2), a filling mandrel (23) guided up and down in the recesses (28.1, 28.2), and an upper punch arranged above the lower punch (24) (25) and a molding mandrel (22) arranged facing the upper surface of the filling mandrel (23),
The upper surface of the lower punch (24) is disposed below the upper surface of the central mandrel (26), and the upper surface of the filling mandrel (23) and the upper surface of the die (27) are flush with the upper surface of the central mandrel (26). Thus, a filling cavity (28) is formed by the outer peripheral surface of the central mandrel (26), the upper surface of the lower punch (24), and the inner peripheral surfaces of the filling mandrel (23) and the die (27),
Filling the filling cavity (28) with metal powder;
The upper punch (25) is inserted into the die (27) to pressurize the metal powder, and the molding mandrel (22) is inserted into the die (27) in contact with the upper surface of the filling mandrel (23). By pushing down the filling mandrel (23), a preformed body having an outer contour formed by the forming mandrel (22) and the die (27) is formed so as to form the ball track (7) by the forming mandrel (22). ,
A method in which the preform is extracted and sintered . After forming the preform, the upper punch (25) and the molding mandrel (22) are extracted from the die (27) upward, and the lower punch (24) is raised to extract the preform. The method of claim 1. The metal powder under pressure by the pressure and heat, characterized that you form a preform, the method according to claim 1 or 2. During pressurization, die and characterized that you heat the at least one punch (24, 25), The method of claim 3. It characterized that you compress the surfaces of the ball raceway (7) after sintering method according to any one of claims 1 to 4. The surface of the ball raceway (7) is compressed by at least one ball after sintering (32), the ball is characterized in that the obtaining pressurizing the pressure vertically against a ball raceway any one of claims 1 to 5 The method described in 1. Method according to claim 6 , characterized in that the ball (32) compresses at least one partial region of the ball trajectory (7) at least once. Then forged parts (3) completing the sintering, insert sintered to (3) on the die (27) center mandrel in (26) having a ball track (7), forging the same mode of construction was pressure sintered bodies (3) with a tool, then characterized in that to leave disconnect the sintered body, the method according to any one of claims 1 to 7. Parts (3) completing the sintering coining after sintering, insert the sintered body (3) having a ball track (7) on the die (27) center mandrel in (26), the same structure It was pressure sintered bodies (3) in coining tool manner, then, characterized in that to leave disconnect the sintered body, the method according to any one of claims 1 to 8. The features that you form an angle formed Suyo the ball trajectory of the preform (7) with respect to the vertical direction of the pressing axis line (20), The method according to any one of claims 1 to 9 . Characterized that you formed ball Lumpur trajectory (7) into a substantially elliptical shape, the method according to any one of claims 1 to 10. The area of the ball running surface is a subregion ball Lumpur trajectory (7) (16, 16 '), characterized in that the heat treatment method according to any one of claims 1 to 11. The area of the ball running surface is a partial area of the ball Lumpur trajectory (7) (16, 16 ') which comprises treating the front surface, A method according to any one of claims 1 to 12.

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