Pivot pin, fastening arrangement for a ball joint and motor vehicle

Abstract

Pivot pin (2) with a longitudinal direction, a conically tapered fastening part (4) and a joint part (6), wherein a threaded section (12) carrying an external thread (28) is arranged between the fastening part (4) and the joint part (6), characterized in that the threaded section (12) is designed as a component separate from the joint part (6) and the fastening part (4).

Description

[0001] The invention relates to pivot pins with a longitudinal direction, a conically tapered fastening portion and a joint portion, wherein a threaded section carrying an external thread is arranged between the fastening portion and the joint portion, a fastening arrangement for a ball joint with such a pivot pin and a motor vehicle.

[0002] Such pivot pins are known from the prior art and can be used in particular in the automotive sector in a chassis. In the chassis of an automobile, articulated connections ensure that the interaction of moving parts and the kinematic specifications are met during driving. For example, a guide joint is connected to a pivot bearing via a conical connection. The conical connection consists of a conically tapered fastening part being pressed into a likewise conical recess. By selecting certain cone ratios, a relatively strong connection is achieved via a self-locking effect, thus further securing the connection against loosening. However, shock loads during driving do not rule out loosening, so the connection is usually additionally secured with a lock nut.The lock nut is screwed onto a shaft portion opposite the opening of the holder, which can be designed as a threaded bolt, for example, whereby the shaft portion protrudes from the component to which the pivot pin is to be attached.

[0003] Ensuring the nut support is correctly and securely requires additional machining effort. Depending on the component, direct access for cutting tools is not always guaranteed, so special solutions are required. One option for machining the nut support surface can be achieved, for example, using side milling cutters that approach the machining position from the front or using special tools that machine the nut support surface from below through a holder designed, for example, as a tapered bore. This has a time-, cost-, and investment-intensive impact on the machining process. Such an arrangement with a lock nut is also space-intensive in terms of height.

[0004] From a customer service perspective, depending on their location in the landing gear, disassembly / assembly may be difficult due to limited space. The exposed nut also represents a point of attack for corrosive influences, which could compromise the secure connection in the long term under unfavorable conditions. However, for safety reasons, secure attachment of these joints to the moving landing gear components must be ensured due to the prevailing forces.

[0005] CN 1 09 695 625 A discloses a ball stud assembly in which a cylindrical shaft portion of the ball stud penetrates an inner bore of an intermediate piece and is secured with a nut on the side of the component to which the ball stud is attached, opposite the spherical portion of the ball stud. The intermediate piece has a tapered outer surface and is inserted into a suitably designed recess in the component. This allows for improved stress distribution within the component, making component breakage less likely and thus increasing operational reliability.

[0006] The generic document DE 10 2019 103 573 A1 describes a stabilizer assembly for a chassis of a motor vehicle, in which a connecting element is detachably connected to a torsion spring by means of a clamping assembly arranged in a tubular end section. The clamping assembly comprises a conical element and a spreading element with at least two clamping arms. The connecting element can be designed to be screwed to the spreading element.

[0007] In the Fig. 1 to 2, using the example of a guide joint that creates a movable connection between the wishbone 108 and the component 112 in the form of a pivot bearing, such a connection is illustrated, which corresponds to the current state of the art and is known per se in its arrangement and implementation. The guide joint creates an articulated connection between the wishbone 108 and the component 112 on the chassis side. It compensates for angular changes between the aforementioned parts in relation to one another, which occur during driving, for example, due to compression and rebound movements as well as steering movements. The wishbone 108 is firmly connected to the component 112 via a conical connection of its pivot pin 102. The pivot pin 102 has a conical fastening portion 104 in the form of a conical shaft, which is pressed into a receptacle 110 that is provided in the component 112 to which the wishbone 108 is to be attached.On the side opposite the fastening part 104, the pivot pin 102 has a joint or ball part which is in the . Fig. 1 is not visible because it is enclosed and thus hidden by the housing of the guide joint.

[0008] The fastening part 104 is held in the receptacle 110 by a force-locking connection. However, it could slip out of the receptacle 110 under shock loads, which is why the fastening part 104 in the form of a threaded bolt with a shaft or bolt portion protrudes from the top of the component 112 and is secured against unintentional loosening by a lock nut 114 and a washer 116.

[0009] In Fig. 2 is a cross-section of the prior art pivot pin 102 of Fig. 1. In the lower part of the figure, the joint portion 106 of the ball joint can also be seen, since the pivot bearing is not shown in this figure. It can be seen that the pivot pin 102 sits in the component 112 similar to a cork in a bottle neck, but during the joining process, a threaded portion emerged from the component 112, so that this threaded portion now protrudes from the component 112. The lock nut 114 was then screwed onto the threaded portion so that the fastening portion 104 sits firmly in the receptacle 110 and cannot leave it even in the event of strong impacts or other acting forces.

[0010] The object of the present invention is to further develop a pivot pin of the type mentioned above in such a way that simplified assembly is possible. It is also the object of the present invention to design such a pivot pin in such a way that its susceptibility to corrosion is reduced.

[0011] The object is achieved according to the invention in that the threaded section is designed as a component separate from the joint part (6) and the fastening part. This means that the pivot pin can be screwed to another component, even if the component is only accessible from one side. A receptacle or bore that completely penetrates the component is not necessary, nor is securing by a lock nut arranged on the opposite side. The threaded section extends along the longitudinal axis of the pivot pin and is arranged between the fastening part, which tapers conically in the joining direction, and the usually spherical joint part. The cross section of the threaded section can be significantly larger than the cross section of the fastening part.For example, the threaded section can have an extension transverse to the longitudinal direction, for example, a diameter that is at least 1.5 times or at least twice as large as the extension transverse to the longitudinal direction or as the diameter of the fastening portion. This makes it possible, for example, to use a rubber bellows as a seal for the joint, of which the pivot pin is a component, since this allows the rubber bellows or seal to rest fully on the end face of the threaded section. The diameter of the fastening portion can be considered, in particular, the maximum diameter of the conically shaped fastening portion.

[0012] In a further development of the invention, it is provided that the fastening part and the joint part are designed as individual components that can be screwed together. For this purpose, a shaft part of the joint part can have an external thread. The fastening part can then have a matching bore or a blind hole that has a corresponding internal thread. The joint part can then be screwed into the fastening part. The now connected parts can then be screwed into a receptacle that has a thread that corresponds to the thread of the threaded section. The threaded section could be permanently connected to the joint part or be designed as a single piece with it. However, this would lead to more complex production and assembly and to reduced flexibility when used in different joint or chassis variants. The threaded section is therefore designed as a separate component.The pivot pin then consists of a total of three individual parts, namely the joint part, the threaded section and the fastening part.

[0013] Preferably, the threaded portion can have engagement surfaces for a tool capable of exerting torque on the threaded portion. The engagement surfaces can be configured, for example, in the form of an external hexagon or an external square. The pivot pin or threaded portion can then be particularly easily inserted into the corresponding component and secured thereto by screwing.

[0014] As already indicated, the threaded section is designed as a separate component from the joint portion and the fastening portion. The threaded section can then first be slipped onto a base body or a shaft portion of the joint portion before the joint portion is then screwed to the fastening portion. Together, the components can then be inserted into a correspondingly designed receptacle in a component to which the pivot pin is to be connected. The fastening portion is inserted into a likewise conically tapered portion of the receptacle and pressed into it during the subsequent screwing process, so that both a positive connection through the threaded connection and a frictional connection through the press fit of the conical fastening portion in the receptacle exist.

[0015] If the threaded portion is designed as a separate component, it can have a through-hole into which an axle portion or shaft of the joint portion can engage. It is also advantageous in this embodiment if the joint portion has a shaft with an external thread. It is then further advantageous if the fastening portion has a cylindrical cavity with an internal thread corresponding to a shaft of the joint portion. The plug-in and screw connection described above can thus be produced in a simple manner.

[0016] In an alternative embodiment, the threaded portion can be formed integrally with the fastening portion. The fastening portion then has a frustoconical fastening portion and a substantially cylindrical threaded portion. The threaded portion preferably has a larger diameter than the fastening portion.

[0017] A fastening arrangement according to the invention for a ball joint can have a pivot pin of the type described above and a receptacle for the fastening portion of the pivot pin, wherein the receptacle can have a cylindrical opening with a thread corresponding to a thread arranged on the threaded portion. A receptacle is understood in particular to be a device designed to receive the pivot pin or its fastening portion and to be connected to it. The receptacle can be a hole or a bore, wherein it has a conically tapered portion corresponding to the fastening portion of the pivot pin. The receptacle can also have a cylindrical portion arranged on a side of the conically tapered portion facing the outside of the receptacle.The cylindrical portion of the receptacle is then usually connected to the end of the conical section with the larger diameter. The cylindrical portion may have an internal thread.

[0018] A motor vehicle according to the invention has a pivot pin or a fastening arrangement of the type described above. In such a motor vehicle, the invention can be used in particular as a guide joint for connecting a wishbone to a pivot bearing.

[0019] Embodiments of the invention are explained in more detail with reference to the drawings and the following description. They show: Fig. 3: a first embodiment of a pivot pin according to the invention in a schematic perspective view, Fig. 4: a section of the first embodiment, Fig. 5: the first embodiment in a side exploded view, and Fig. 6: the first embodiment in an exploded view from below.

[0020] Fig. 3 shows a first embodiment of a pivot pin 2 according to the invention in a schematic perspective view. The upper part of the figure is a sectional view so that the details of the connection are clearer. The pivot pin 2 is fully assembled in the view shown and establishes a connection between the component 20 and the bearing shell 8 of a pivot bearing. The pivot pin 2 has a fastening portion 4 and a spherical joint portion 6, which is largely concealed by the bearing shell 8 in the figure. Only the shaft 22 of the joint portion 6 is visible in the figure. The shaft 22 penetrates the threaded portion 12 and extends into the fastening portion 4. The shaft 22 and thus also the joint portion 6 are screwed to the fastening portion 4 so that the threaded portion 12 is clamped between the fastening portion 4 and the joint portion 6.Both the fastening part 4 and the joint part 6 and the threaded section 12 are designed to be essentially rotationally symmetrical about the longitudinal axis M.

[0021] The fastening portion 4 tapers upwards in the figure and thus tapers towards the interior of the component 20. The fastening portion 4 engages with the inner, also conical portion 24 of the receptacle 10. The conical shape results in a press fit and thus a frictional connection, via which the majority of the forces generated are transmitted. The receptacle 10 has a cylindrical portion 26 which has an internal thread (not shown). The internal thread of the cylindrical portion 26 interacts with the external thread arranged on the outside of the threaded portion 12. This makes it possible to fix the threaded portion 12 in the receptacle 10, creating a firm connection between the pivot pin 2 and the component 20. As already described, a large portion of the forces are transmitted via the press fit between the fastening portion 4 and the receptacle 10.The connection is secured by the screw connection between the threaded section 12 and the receptacle 10. At the same time, when screwed in, the fastening portion 4 is pressed particularly firmly into the receptacle 10, creating a particularly strong connection.

[0022] Fig. 4 shows a fully sectioned view of the first embodiment. In contrast to the illustration in Fig. 3, the bearing shell is not shown here, so that the joint portion 6 is completely visible. It consists of the shaft portion or the shaft 22 and the ball portion 30 arranged opposite it. The shaft 22 is screwed to the fastening portion 4 and penetrates a central bore in the threaded portion 12, which is designed as a separate component. The complementary connections between the fastening portion 4 and the conical portion 24 of the receptacle 10 on the one hand, and the threaded portion 12 and the cylindrical portion 26 of the receptacle 10 on the other hand, result in a particularly durable connection that is not overloaded by forces acting in both the axial and radial directions.

[0023] Fig. Figure 5 shows the first embodiment in a side exploded view. It is particularly clear here that the pivot pin 2 consists of three individual parts, namely the fastening portion 4, the threaded portion 12, and the joint portion 6. The upper part of the figure again shows component 20, which can accommodate the pivot pin in the receptacle 10, which in turn consists of the conical portion 24 and the cylindrical portion 26. The joining direction runs from bottom to top in the figure.

[0024] The fastening portion 4 has the geometric shape of a truncated cone. Furthermore, it can have a threaded opening on its larger end face into which the shaft 22 of the joint portion can be screwed. The opening can be designed as a bore or a blind hole. On its upper side or on its smaller end face, the fastening portion 4 can have a further opening in the form of a hole 18. This can be provided, for example, with a hexagon socket or another profile suitable for a corresponding tool in order to enable the fastening portion 4 to be fixed during screwing to the joint portion 6.

[0025] The threaded portion 12 has a central through-opening in the form of a hole 14, through which the shaft 22 of the joint portion 6 is inserted during assembly. Furthermore, the threaded portion 12 has an external thread 28 on its circumference in an area facing the fastening portion 4. In an area facing the joint portion 6, the threaded portion 12 has engagement surfaces 16 in the form of an external hexagon, with the aid of which the joint pin 2 can then be screwed into the thread of the cylindrical portion 26 of the receptacle 10.

[0026] The joint portion 6 has already been described in detail above. It differs from prior art joint pins, among other things, in that the shaft 22 is not tapered, but instead has connecting means, for example, in the form of an external thread, for connection to the fastening portion 4.

[0027] Fig.Figure 6 shows the first embodiment in an exploded view obliquely from below. In this view, the two bores or holes 14, 18, which are arranged in the threaded section 12 and in the fastening part 4, respectively, are clearly visible. During assembly, the shaft 22 of the joint part 6 first penetrates the hole 14 and then at least partially penetrates the hole 18 of the fastening part 4. A screw connection can then be made using threads not shown in the figure, so that the three individual parts of the pivot pin 2, namely the fastening part 4, the threaded section 12 and the joint part 6, are firmly connected to one another. The entire pivot pin 2 can then be inserted into the receptacle 10 and fixed there using the second screw connection. List of reference symbols 2 pivot pins 4 Fastening portion 6 joint portion 8 bearing shell 10 recordings 12 threaded section 14 holes 16 attack surfaces 18 holes 20 components 22 shaft 24 conical part of the receptacle 26 cylindrical part of the receptacle 28 threads 30 ball share M Longitudinal axis 102 pivot pins 104 fastening portion 106 joint portion 108 wishbones 110 recording 112 component 114 Lock nut 116 Washer

Claims

[1] Pivot pin (2) with a longitudinal direction, a conically tapered fastening part (4) and a joint part (6), wherein a threaded section (12) carrying an external thread (28) is arranged between the fastening part (4) and the joint part (6), characterized by that the threaded portion (12) is designed as a separate component from the joint portion (6) and the fastening portion (4). [2] Pivot pin (2) according to claim 1, characterized by that the fastening part (4) and the joint part (6) are designed as individual components that can be screwed together. [3] Pivot pin (2) according to one of the preceding claims, characterized by that the threaded portion (12) has engagement surfaces (16) for a tool which is capable of exerting a torque on the threaded portion (12). [4] Pivot pin (2) according to one of the preceding claims, characterized bythat the threaded portion (12) has a through opening into which a shaft (22) of the joint part (6) can engage. [5] Pivot pin (2) according to one of the preceding claims, characterized by that the joint part (6) has a shaft (22) with an external thread. [6] Pivot pin (2) according to one of the preceding claims, characterized by that the fastening part (4) has a cylindrical cavity with an internal thread corresponding to a shaft (22) of the joint part (6). [7] Pivot pin (2) according to one of the preceding claims, characterized by that the threaded section (12) is designed in one piece with the fastening part (4). [8] Fastening arrangement for a ball joint, with a pivot pin (2) according to one of claims 1 to 7 and with a receptacle (10) for the fastening part (4) of the pivot pin (2), characterized bythat the receptacle (10) has a conical tapered portion (24) and a threaded portion with an internal thread. [9] Motor vehicle with a pivot pin (2) or a fastening arrangement (2, 10) according to one of the preceding claims.

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