Method for producing a ball joint and associated lining

The invention relates to a method for producing a ball pin out, Bearing shell and the joint housing existing, with a between the joint housing and ball stud arranged sealing bellows to be provided ball joint, in particular for motor vehicles, by extrusion coating on the with the the joint ball mounted bearing shell provided with ball pivot Plastic in a divided injection mold and one for use in this process certain bush.

A method for producing a ball pin out, bearing shell and the joint housing existing ball joint is known from DE 40 09 156 A1. In this known method is the ball stud after the bearing shell has been placed on the joint ball in a split injection mold inserted and for the manufacture of the joint housing with plastic molded. Since the plastic is introduced with high pressure into the mold, there is a risk that plastic material between the bearing shell and the joint ball the spherical hinge passes, so that the ball joint is useless and the fats of the shell prior to injection molding is not possible. After Functional testing of the injection mold removed the ball joint is still required to lubricate the joint and the joint between the housing to mount and ball stud to be placed joint boot by his Öffnungswulst housing side in a in the manufacture of the joint housing formed groove and his pin-sided Öffnungswulst in an on loaded ball pin groove formed and secured by a clamping ring will.

The invention has the <b>task</b> basis, while avoiding the Disadvantages of the known method a heavy duty ball joint to provide and the information needed to complete assembly work to reduce.

The <b>solution</b> this task by the invention is characterized, that before placing the ball pin in the injection mold the sealing bellows with its housing-side Öffnungswulst on the bearing shell positioned and and by molding between the bearing shell Housing is fixed.

The already before placing the ball pin in the injection mold with its housing-side Öffnungswulst on the bearing shell set Sealing bellows arises in when inserting into the injection mold appropriate design of the injection mold an effective Sealing of the for the manufacture of the joint housing in the injection mold cavity formed over the entire ball joint, because the permanently elastic material of the sealing a reliable seal guaranteed. At the same time the housing side is the Öffnungswulst Sealing bellows during the manufacture of the joint housing at this set, so that a later-consuming assembly process is eliminated. The The method according to the invention thus not only eliminates the terms of Risk of leaks existing drawbacks of the known method, but also avoids some of the subsequent assembly operations as well as the additional use of a clamping ring.

According to a further feature of the invention, the pivot-side Öffnungswulst of the bellows before engaging the ball stud in the Injection at a placed on the threaded stem of the ball stud Abdeckbüchse set. This results in a stretched, streamlined and reduced diameter position of the bellows in the Injection mold, the good positioning of the bellows while soaking in ensures injection and thus both a reliable seal the sealing gap between the injection mold and shell as well as a reliable attachment between the shell and housing guarantees.

To give, after removal of the provided with the joint housing the ball joint to facilitate the injection of the final assembly of the bellows, is further proposed with the invention, the pivot-side, by a clamping ring Öffnungswulst loaded after removal of the finished ball joint from the injection mold via a at Abdeckbüchse configured conical transition into a covenant of the ball stud to push formed groove. The conical transition of Abdeckbüchse this simplifies the final assembly of the bellows.

By setting both of the bellows during Öffnungswulste the injection molding is a closed within the sealing bellows Cavity formed in accordance with a further feature of the invention, prior to insertion of the ball pin in the injection mold with a Lubricant fill can be provided so that the invention made ball joint before its final preparation with the required lubricant can be provided. It eliminates in this way subsequent introduction of lubricant.

In a preferred embodiment of the method according to the invention is of plastic by means of a low-pressure injection molding, preferably a gas-assisted injection molding process or a two-component method introduced with a foam component. The case reduce the applied low pressures not only the risk of acquiring of leaks, but cheapen the Machinery for performing the method.

Since the ball joint manufactured by the method according to the invention a 100% coverage of the used to form the joint housing Plastic against the joint ball through the bearing shell and the Sealing bellows takes place, according to a further feature of the invention as a plastic-reinforced plastic may be used because the in Plastic embedded Armierungsstoffe no risk of damage represent the spherical bearing surface of the joint ball. By Use of a reinforced plastic increases the resilience of the Ball joint according to the invention.

The product intended for use in the inventive bearing shell is characterized according to the invention in that the opening circumferential edge of the bearing shell with an annular contact surface for the provided inside edge of the housing side of the sealing Öffnungswulstes is. In this way, a reliable position of the bellows achieved on the bearing shell when the bearing shell provided with the Ball stud is inserted into the injection mold.

In a preferred embodiment, the contact surface is inclined at an outwardly, also a stop for the pivoting the ball pin forming extension of the bearing shell formed.

To the joint housing to extrusion-coated bearing shell in the mold position, can according to a further feature of the invention Injection molding tool in the region in which the sealing bellows for sealing the Cavity is present, be designed such that it, in cooperation with a correspondingly shaped extension of the spherical shell this in a defined position in the injection mold sets. In addition, this End, the bearing shell with an opening opposite, cone-like on its outer side formed protrusion be provided.

Another position securing the bearing shell in the finished joint housing can according to the invention by formed on the outside of the bearing shell increases and / or take place indentations. The elevations and / or depressions can preferably rib-like on at least one circle of latitude extend the bearing shell, whereby a security against slippage Bearing shell opposite the hinge housing in the direction of the ball pivot axis is created. Further rib-like, of at least one meridian are bearing shell extending elevations and / or depressions used to a rotation of the bearing shell in relation to the joint housing about the central longitudinal axis of the ball joint and to prevent the stiffen spherical shell so that they attach themselves by the injection pressure Injection molding of the housing is not deformed, especially in the field of Pole of the joint ball.

In the drawing an embodiment is an invention by the Procedure and using a bearing shell according to the invention Ball joint produced illustrated, and show namely:<dl tsize="7"><dt>Fig. 1</dt><dd>a longitudinal section through a lower half in an injection mold inserted, provided with the bearing shell and the sealing bellows Ball stud prior to the manufacture of the joint housing,</dd><dt>FIG. 2</dt><dd>a cross section through the injection mold with an inserted ball stud according to section line II-II in Fig. 1 and</dd><dt>Fig. 3</dt><dd>a longitudinal section through the finished ball joint.</dd></dl>

The finished ball joint shown in FIG. 3 consists of a ball stud 1, a Bearing shell 2, an integral with a strut brace 31 Joint housing 3 and a sealing bellows. 4

The ball stud 1 comprises a joint ball 11, the transition means of a 12 merges into a cylindrical collar 13, to which a threaded pin 14 is formed. In the end face of the threaded pin 14 is an Allen 15 formed as a key area. The collar 13 is provided with an annular provided receiving 16th

The serving for the storage of the ball stud 1 via the ball joint 11 Bearing shell 2 is held positively in the joint housing. 3 It is to this end on its outer spherical surface with a longitudinally the Equator extending annular increase 23 which a Slipping of the bearing shell 2 towards the ball pivot axis 17 prevented, and with rib-like projections 22 along the meridians the spherical shell surface, the rotation of the bearing shell 2 to the Ball pivot axis 17 prevent the housing.

These ribs are also to stiffen the bearing shell 2 to the Deformation - especially in the area of ​​the flat in the pole of the sphere 11 - during the injection molding by the high pressure and the high to prevent temperature of the plastic melt.

The surrounding the opening of the bearing shell 2 edge is inclined at a by outwardly extending extension 24 is provided whose conical inner surface serves as a stop for the pivoting movement of the ball stud. 1 The maximum swivel angle of the ball stud 1 relative to the joint housing 3 and thus of the bearing shell 2 by dashed lines in Fig. 3 located.

The outside of the extension 24 forms an annular abutment surface 25 for a housing side Öffnungswulst 41 of the bellows 4, which with a pivot-side Öffnungswulst 42 in the groove 16 of the ball stud 2 is used, and using a clamping ring 43rd

For the production of the ball joint as described above first on the joint ball 11 of the ball stud 1 the bearing shell 2 placed. Then the housing side Öffnungswulst 41 is in the annular used bearing surface 25 of the bearing shell. 2 The pivot-side Öffnungswulst 42 of the bellows 4 arrives here on a conical Transition 51 a Abdeckbüchse 5 that the over the threaded pin 14 Ball stud 1 is pushed up to the stop at the bottom of the collar 13 has been, whereby it is tightly stretched and reduced in diameter and so the insertion into the injection mold 6 and the sealing by the meet the housing side Öffnungswulst 41 of the bellows 4 reliable can.

In this state, the ball pivot 1, bearing shell 2, the bellows 4 and Abdeckbüchse 5 inserted into a two-part injection mold. 6 The two Halves 61 and 62 of this injection mold 6 are in cross-section of FIG. 2 to recognize. In Fig. 1, the plan view of the lower half 61 of the injection mold 6 drawn.

Both drawings show that the injection mold 6 a bearing shell 2 surrounding cavity 63 which, in one of the outer contour the suspension strut 31 the corresponding cavity 64 passes (see FIG. 1). Both cavities 63 and 64 are by the elastic material of the sealing bellows 4 relative to the extension 24 of the bearing shell 2 sealed. In this area is the sealing bellows 4 completely by a corresponding Supporting surface 65 of the two halves 61 and 62 of the injection mold 6 surrounded. This supporting surface 65 is shaped so that they, in cooperation with the correspondingly shaped extension 24 of the ball shell 2, not only by Pinching of the bellows 4, the cavities 63 and 64 seals, but at the same time the bearing shell 2 in the mold 6 in a defined position fixed. This fixation can be supported by a pin-like projection 21 in the outer pole area of ​​the bearing shell. 2 The at the injection between the 6 and the bearing shell 2 strangulated Öffnungswulst 41 subsequent and by Abdeckbüchse 5 stretched and reduced diameter portion of the bellows 4 to the pivot-side Öffnungswulst 42 finds the embodiment in a cylindrical recess 66 of the injection mold 6 square.

After closing the injection mold 6 is preferably glass fiber reinforced plastic by means of a low-pressure injection molding, preferably by the injection molding or after a Gasinnnendruck Two-component process with a foam component into the cavities 63 and 64 of the injection mold 6 is inserted so that the joint housing 3 integrally is produced with the Stabilizer 31st In this preparation is simultaneously the housing side Öffnungswulst 41 of the bellows 4 formed between the bearing shell 2 and the joint housing. 3 It is also clear through the rib-shaped and ring-shaped elevations 22 and 23 of Bearing shell 2 a positive fixation of the bearing shell 2 within the Joint housing. 3

After opening the injection mold 6, the ball joint is almost fully assembled removed. It is simply not necessary to taper at the transition 51 of Abdeckbüchse 5 lying pivot-side Öffnungswulst 42 over the conical transition 51 in the groove 16 of the ball stud 1 to slide. Since the area enclosed by the sealing bellows 4 room before the onset the ball pivot 1 in the injection mold 6 with a lubricant fill provided may have been, the ball joint is by decreasing Abdeckbüchse 5 ready for installation.

<b>LIST OF REFERENCE NUMBERS</b>

<dl tsize="3" compact="compact"><dt>1</dt><dd>ball pin</dd><dt>11</dt><dd>joint ball</dd><dt>12</dt><dd>transition</dd><dt>13</dt><dd>waistband</dd><dt>14</dt><dd>threaded stud</dd><dt>15</dt><dd>Allen</dd><dt>16</dt><dd>receiving</dd><dt>17</dt><dd>central longitudinal axis</dd><dt>2</dt><dd>bearing shell</dd><dt>21</dt><dd>head Start</dd><dt>22</dt><dd>increase</dd><dt>23</dt><dd>increase</dd><dt>24</dt><dd>extension</dd><dt>25</dt><dd>storage area</dd><dt>3</dt><dd>joint housing</dd><dt>31</dt><dd>Stabilizer</dd><dt>4</dt><dd>sealing bellows</dd><dt>41</dt><dd>Öffnungswulst</dd><dt>42</dt><dd>Öffnungswulst</dd><dt>43</dt><dd>clamping ring</dd><dt>5</dt><dd>Abdeckbüchse</dd><dt>51</dt><dd>transition</dd><dt>6</dt><dd>injection mold</dd><dt>61</dt><dd>half</dd><dt>62</dt><dd>half</dd><dt>63</dt><dd>cavity</dd><dt>64</dt><dd>cavity</dd><dt>65</dt><dd>supporting surface</dd><dt>66</dt><dd>recess</dd></dl>