Ball joint and method for manufacturing the same

Abstract

The present invention relates to a ball joint and a method for manufacturing the ball joint. In the present invention, a housing has a first opening in a first edge region in a direction toward a pin of a ball stud, the ball stud protrudes from the first opening, a gap is provided between an inner wall of a cavity and an outer wall of a bearing shell, a bushing is injected into the gap, and the housing has a second opening in a second edge region opposite to the first opening, the second opening is used to inject the bushing through the cavity, and the ball joint has one or more structural elements for fixing the bushing to the inner wall of the second opening.

Description

Technical Field

[0001] The technology disclosed in this specification relates to a ball joint and a method for manufacturing the ball joint. Background Art

[0002] Ball joints are used, for example, as components of the body of a motor vehicle, preferably a passenger car.

[0003] Patent Document 1 describes a ball joint in which a ball stud is rotatably supported by a bushing accommodated in a housing. In this technology, the bushing is made of a synthetic material that reacts to heat and is formed between the ball stud and the housing by injection molding or casting.

[0004] Patent Document 2 describes a ball joint in which a bearing bush is made of plastic injected from an opening of a housing and solidified, and has a housing with a fixing unit integrally formed therewith.

[0005] Patent Documents 3 and 4 describe a ball joint having a housing having a cavity, an upper opening, and at least one injection port provided on the opposite side of the upper opening. In this technology, a ball stud inserted from the upper opening of the housing is fixed as close to the center of the cavity as possible, and then a bushing made of a polymerizable plastic such as a thermoplastic resin is injected from the injection port.

[0006] Patent Document 5 describes a ball joint having a housing that houses a bearing bush for supporting a ball of a ball stud. In this technology, after the ball stud is fixed at a predetermined position, an elastomeric plastic made of a material with good sliding friction properties is injected into the gap between the housing and the ball to form the bearing bush.

[0007] Patent Documents 6 and 7 describe a ball joint in which plastic is injected into the gap between the bearing shell of the ball that rotatably accommodates the ball stud and the housing, thereby positioning the bearing shell together with the ball stud in the housing. In these technologies, since the housing has an opening with a larger radius than the injected plastic, the injected plastic covers the ball stud from the bottom of the housing. In addition, the inner diameter is reduced in the direction of the pin of the ball stud. In the technology of Patent Document 7, the injected material flows out of the opening of the housing in the direction of the ball stud to form a connection with the sealing cover.

[0008] Patent Document 1: German Utility Model Specification No. 1796019

[0009] Patent Document 2: International Publication No. 1997 / 41361

[0010] Patent Document 3: International Publication No. 1999 / 09328

[0011] Patent Document 4: International Publication No. 1999 / 28639

[0012] Patent Document 5: European Patent Application Publication No. 0860619

[0013] Patent Document 6: International Publication No. 2000 / 26550

[0014] Patent Document 7: German Patent Invention Specification No. 19830593

[0015] In the technology of Patent Document 1, in order to prevent the bushing from rotating in the housing, one or more recesses for fixing the bushing can be provided on the inner surface of the housing. However, Patent Document 1 does not describe how to implement the recesses. In the ball joint of Patent Document 1, the diameter decreases sharply in the stretching direction (the direction of the ball stud), and thus, the bushing may be broken during stretching.

[0016] In the technology of Patent Document 2, the inner wall of the housing is roughened or serrated to reliably fix the bearing pad injected into the housing.

[0017] In the technologies of Patent Documents 3 and 4, the inner wall of the shell or the cavity has a rough surface or an unprocessed surface of casting, sheet metal, cold extrusion or forging. If necessary, grooves or recesses may be added to the surface. However, there is no description on how to achieve the rough surface or unprocessed surface or grooves or recesses.

[0018] In Patent Document 5, after the bearing and the damping element are injected into the opening of the housing, a closing element made of a very hard and durable material is injected. A groove extending radially outward is provided on the inner side of the housing, and the closing element is engaged in the groove. Since the groove is very sharp, when a large load is applied in the axial direction, the closing element may be broken.

[0019] In the existing method of injecting a bushing into the gap between the bearing and the housing to position the ball stud in the housing as in Patent Documents 6 and 7, there is a risk that the injected bushing may become loose from the inner side of the housing, causing the bushing to break at the sharp edge on the inner side of the housing and resulting in malfunction of the ball joint, especially when a large axial force is applied to the ball stud at a high temperature of more than 80°C. Summary of the invention

[0020] The object of the present invention is to provide a ball joint and a method for manufacturing a ball joint, in particular a ball joint for a vehicle chassis, which can be manufactured easily and cheaply and can withstand large loads even at high temperatures.

[0021] The technology disclosed in this specification can be realized in the following manner, for example.

[0022] The ball joint disclosed in the present specification comprises a shell having a cavity for accommodating a ball of a ball stud, the ball being movably supported in a bearing shell, and is characterized in that the shell has a first opening portion in a first edge region in a direction toward the pin of the ball stud, the ball stud protrudes from the first opening portion, a gap is provided between the inner wall of the shell and the outer wall of the bearing shell, a bushing is injected into the gap, and the shell has a second opening portion in a second edge region opposite to the first opening portion, the second opening portion being used for injecting the bushing through the cavity, and the ball joint has one or more structural elements for fixing the bushing to the inner wall of the second opening portion.

[0023] In this ball joint, by fixing the injected bushing to the inner wall of the housing, even if the second opening is larger than the outer diameter of the ball of the ball stud and even at a high temperature of 80°C or above, it is possible to withstand a large load applied to the ball stud.

[0024] In addition, preferably, the structural element is arranged between the second opening portion and the equatorial region of the ball, the second opening portion is larger than the first opening portion and larger than the outer diameter of the bearing shell, and the second opening portion is used to embed a subassembly consisting of a ball stud and a bearing shell mounted on the ball into the housing.

[0025] The ball joint as the structural element particularly has the following structures a) to d) as structural elements, either alone or in any combination.

[0026] a) having significant surface roughness / concavity on at least a portion of the inner wall of the housing;

[0027] b) the volume of the bushing increases toward the second opening;

[0028] c) forming one or more grooves / recesses, and / or knurling on the inner wall of the housing, either alone or in any combination; and

[0029] d) forming a step portion which is connected to the second opening and expands radially toward the first opening

[0030] The arithmetic mean roughness value Ra of the inner wall of the housing is preferably 10 μm or more and 75 μm or less, and particularly preferably 10 μm or more and 63 μm or less.

[0031] Furthermore, the volume of the bush increases toward the second opening, so that the wall thickness of the bush becomes maximum in the region of the step portion.

[0032] Furthermore, at least one spiral groove is formed on the inner wall of the housing, and / or a plurality of grooves / recesses are formed in a manner of being separated from each other or intersecting each other, and / or knurling is formed.

[0033] The housing may include a wall portion curved radially inward in the region of the second opening.

[0034] When one or more grooves / recesses and / or knurling are formed on the inner wall of the housing, their depth is preferably not less than 0.3 mm and not more than 1.5 mm, and they are preferably disposed in the region of the second opening.

[0035] The first edge region of the housing is formed into a protrusion shape extending in the axial direction, the second edge region of the housing is formed into a protrusion shape extending in the axial direction, and the bushing covers the first edge region and / or the second edge region.

[0036] Preferably, the ball of the ball stud has a recess in the polar region, and the projection of the bearing shell engages with the recess. As a result, the bearing shell is securely mounted on the ball of the ball stud. After the ball joint is completed by injecting the bushing, when the ball stud is first rotated or swung, the projection engaging with the recess of the ball is broken off, so that the ball can rotate freely in the bearing shell.

[0037] The manufacturing method of the ball joint includes the following steps: forming one or more structural elements on the inner wall of the shell; before or after the forming of the structural elements, embedding a subassembly consisting of a ball stud and a bearing shell mounted on the ball into the shell; then, injecting a bushing into the gap between the subassembly and the inner wall of the shell.

[0038] More preferably, before the ball stud is embedded in the housing and before the bushing is injected, at least a portion of the inner wall of the housing is given significant surface roughness / concavities by machining, and / or one or more grooves / recesses and / or knurling is produced in the inner wall of the housing by machining.

[0039] Furthermore, in the housing, the second opening is formed radially inwardly so as to be connected to a step portion that expands in the radial direction toward the first opening.

[0040] One or more structural elements are formed on the inner wall of the housing by a forming method such as extrusion forging, bending, or upsetting, which forms the housing radially inward. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 It is a longitudinal sectional view of the casing in the first embodiment.

[0042] Figure 2 Yes Figure 1 A longitudinal sectional view of the ball joint of the housing.

[0043] Figure 3 It is a longitudinal sectional view of the casing in the second embodiment.

[0044] Figure 4 Yes Figure 3A longitudinal sectional view of the ball joint of the housing.

[0045] Figure 5 It is a longitudinal sectional view of the casing in the third embodiment.

[0046] Figure 6 Yes Figure 5 A longitudinal sectional view of the ball joint of the housing.

[0047] Figure 7 It is a longitudinal sectional view of the preform of the shell.

[0048] Figure 8 is a diagram showing a preform inserted into a forming die together with a subassembly consisting of a ball stud and a bearing bush.

[0049] Fig. 9 This is a diagram showing a housing formed by a forming die.

[0050] Fig.10 It is a figure which shows the housing|casing after a bushing is injected.

[0051] Fig.11 This is a diagram showing the ball joint after being pulled out from the molding die.

[0052] Description of symbols

[0053] 1: Shell;

[0054] 1.1: Hollow;

[0055] 1.1.1: Inner wall;

[0056] 1.2: The first opening;

[0057] 1.3: The second opening;

[0058] 1.4: 1st marginal area;

[0059] 1.4.1: bottom cut;

[0060] 1.5: 2nd marginal area;

[0061] 1.6: Tubular part;

[0062] 1.7: 1st shoulder;

[0063] 1.8: 2nd shoulder;

[0064] 1.9: The first step;

[0065] 1.10: The second step;

[0066] 1V: preform;

[0067] 1.1.1V: inner wall of the preform;

[0068] 1.3V: opening of the preform;

[0069] 1SV: slope;

[0070] 2: ball pin;

[0071] 2.1: Pin;

[0072] 3: ball;

[0073] 3.1: concave part;

[0074] 4: Bearing;

[0075] 4.1: protrusion;

[0076] 5: Bushing;

[0077] 6: Knurling;

[0078] 7: slot;

[0079] 10: forming die;

[0080] 11.1: 1st lower body;

[0081] 11.2: 2nd lower body;

[0082] 12: support body;

[0083] 13: 1st upper body;

[0084] 13.1: 1st forming profile;

[0085] 14: 2nd upper body;

[0086] 14.1: 2nd forming profile;

[0087] 14.2: Contour;

[0088] 15: injection port;

[0089] A: longitudinal axis;

[0090] B: equatorial region;

[0091] d1.2: Inner diameter of the first opening;

[0092] d1.3: inner diameter of the second opening;

[0093] d1.6: inner diameter of the cylindrical part;

[0094] D1: outer diameter of the shell;

[0095] D1.4: outer diameter of the first edge area;

[0096] D1.4': reduced diameter of the first edge region;

[0097] D1.5: outer diameter of the second edge area;

[0098] F: axial force / thrust force;

[0099] FS: rotational force;

[0100] r1: 1st radius;

[0101] r2: second radius;

[0102] r3: the third radius;

[0103] r3V: 3rd radius;

[0104] α1: first angle;

[0105] α2: the second angle;

[0106] α3: the third angle;

[0107] β: side angle;

[0108] γ: The angle of the bevel. DETAILED DESCRIPTION

[0109] A. First Implementation Method:

[0110] Figure 1 The housing 1 of the ball joint is shown. The housing 1 has a cavity 1.1 and two openings, a first opening 1.2 and a second opening 1.3, which are opposite to each other. The first opening 1.2 is located at a first edge region 1.4 on the upper side of the housing 1 in the figure, and the second opening 1.3 is located at a second edge region 1.5 on the lower side in the figure. The housing 1 is formed by casting, sheet metal, cold extrusion or forging.

[0111] The first opening 1.2 on the upper side of the figure has an inner diameter d1.2 which is smaller than the inner diameter d1.3 of the second opening 1.3 on the lower side. A substantially cylindrical cylindrical portion 1.6 having an inner diameter d1.6 larger than d1.2 and d1.3 extends between the first opening 1.2 and the second opening 1.3.

[0112] The housing 1 has an outer diameter D1. The first edge region 1.4 has an outer diameter D1.4 smaller than the outer diameter D1. The outer diameter D1.4 of the first edge region 1.4 is reduced to a reduced diameter D1.4' slightly smaller than the outer diameter D1.4, and an undercut 1.4.1 is formed on the outer contour of the first edge region 1.4. The second edge region 1.5 on the lower side in the figure also has an outer diameter D1.5 smaller than the outer diameter D1.

[0113] Figure 2The cross section of the ball joint is shown, which passes through the ball 3 of the ball stud 2 rotatably received in the bearing bush 4 and the housing 1 into which the bushing 5 is injected. The longitudinal axis A of the ball stud 2 coincides with the longitudinal axis of the housing 1. The bearing bush 4 is arranged in the housing 1 together with the ball 3 of the ball stud 2 (only a part of it is shown here). The bearing bush 4 is preferably formed of POM (polyoxymethylene).

[0114] Plastic, preferably a bushing 5 made of PA (polyamide) or the like, is injected into the gap between the bearing shell 4 and the cavity 1.1 of the housing 1, and the ball stud 2 accommodated in the bearing shell 4 is fixed in the housing 1. In addition, the lower surface of the bearing shell 4, the first edge region 1.4 protruding in the direction of the pin 2.1 of the ball stud 2, and the second edge region 1.5 are covered with rubber by the bushing 5. The bushing 5 reaches the first edge region 1.4 and the periphery of the bottom cut portion 1.4.1, and further reaches the first shoulder 1.7 facing radially outward, and reaches the periphery of the second edge region 1.5 and reaches the second shoulder 1.8 facing radially outward.

[0115] The lower part of the ball 3, here in the polar region not shown, has a recess 3.1 for engaging the protrusion 4.1 of the bearing shell 4. Therefore, when the subassembly consisting of the bearing shell 4 and the ball stud 2 is inserted into the housing 1, the bearing shell 4 is reliably positioned on the ball 3.

[0116] The projection 4.1 has a cut-off portion (not shown). After the ball joint is manufactured, when a rotational force FS is applied to the ball stud 2, the cut-off portion breaks, and the ball 3 of the ball stud 2 can rotate freely in the bearing bush 4. At this time, the projection 4.1 remains in the recess 3.1.

[0117] The subassembly consisting of the ball stud 2 and the bearing bush 4 is inserted into the housing 1 from the second opening 1.3 on the lower side of the figure to the desired position, and at this time, the pin 2.1 protrudes from the first opening 1.2. In assembly, the inner diameter d1.3 of the second opening 1.3 of the housing 1 needs to be slightly larger than the outer diameter of the bearing bush 4. It is also possible to make the second opening 1.3 of the housing 1 at the top and the first opening 1.2 at the bottom. In this case, the ball stud 2 is inserted into the housing 1 in such a way that the pin 2.1 faces downward.

[0118] The inner wall 1.1.1 of the housing 1 has a surface roughness / concavity (arithmetic mean roughness value) not shown in the figure of not less than Ra10μm and not more than Ra63μm as the first structural element (structure a of claim 3). The surface roughness / concavity is preferably made by lathe processing. The significant surface roughness / concavity may exist in the cylindrical portion 1.6 and / or the first opening 1.2 and / or the second opening 1.3, or may exist throughout the entire area of ​​the inner wall 1.1.1 of the housing 1.

[0119] Here, the first structural element is combined with the fourth structural element (structural element d of claim 3), and the fourth structural element is connected to the second opening 1.3 of the housing 1 so as to be oriented in a direction of 100° or more and 130° or less toward the first opening 1.2 (see Figure 1 The first step portion 1.9 is formed in a shape in which the first angle α1 of the first step portion 1.9 is enlarged in the radial direction. The first step portion 1.9 has a convex curved portion having a large first radius r1. The first radius r1 is preferably between 1.0 mm and 6 mm, and particularly preferably between 2.0 mm and 4 mm.

[0120] In the direction of the first opening 1.2, there is a second radius r2 (refer to Figure 1 ), the second radius r2 is preferably between 4 mm and 12.5 mm, and particularly preferably between 6 mm and 10 mm. Thus, the inner diameter of the inner wall 1.1.1 of the housing 1 is reduced from the diameter d1.6 to the diameter d1.2 of the first opening 1.2.

[0121] The inner diameter d1.2 is set so that the inner diameter d1.2 and the ball 3 (see Figure 2 ) between the outer diameters thereof, there is an overlap b in the pulling direction, i.e., the direction of the pin 2.1, and therefore it is able to withstand a larger load in the tensile direction.

[0122] In the housing 1, according to the newly designed internal structure, even if there is no overlap between the diameter d1.3 of the second opening 1.3 of the housing 1 and the outer diameters of the ball 3 and the bushing 4, it is possible to withstand a large axial force / pushing force F in the pushing direction of the ball stud 2 (refer to Figure 2 ), even at high temperatures above 80°C, the ball joint can be prevented from being damaged. Good fixation or good fastening between the injected bushing 5 and the inner wall 1.1.1 is ensured by the significant surface roughness / concavity of the inner wall 1.1.1 of the housing 1. In addition, by having the first step portion 1.9 with a convex curved portion, the bushing 5 will not be displaced or broken, and can withstand a large axial force F. By designing the first step portion 1.9 disposed between the equatorial region B of the ball 3 and the second opening 1.3 in this way, the resistance to the axial force F relative to the ball stud 2 and the bushing 5 can be increased, and the bushing 5 can be prevented from breaking.

[0123] B. Second Implementation Method:

[0124] Figure 3 A longitudinal sectional view of the housing 1 is shown. Figure 4 Show that it has Figure 3 The ball joint of the housing 1. These are basically the same as Figure 1 and Figure 2 The implementation method is the same as Figure 1 and Figure 2The embodiment of the present invention is different in that the housing 1 preferably has a second step portion 1.10 with an angle α2 between 95° and 125°, whereby the inner diameter of the housing 1 is reduced from the inner diameter d1.6 of the cylindrical portion 1.6 to the diameter d1.3 of the second opening 1.3, forming a fourth structural element (structure d of claim 3) disposed between the equatorial region B of the ball 3 and the second opening 1.3 (see Figure 4 ).

[0125] The housing 1 also has a third structural element (structure c of claim 3) which is a knurling 6 provided at the second opening 1.3. Therefore, here, the third structural element and the fourth structural element are provided on the housing 1. However, only one of these structural elements may be provided, that is, only one of the third structural element or the fourth structural element may be provided, or both the third structural element and the fourth structural element may be provided with a significant surface roughness / concavity (see FIG. 1 ) which is the first structural element (structure a of claim 3). Figure 1 and Figure 2 ) combination. When an axial force / punching force F is applied to the ball 3 of the ball stud 2 in the direction of the second opening 1.3 (refer to Figure 4 ), the second step portion 1.10 plays a role in preventing or alleviating the shear damage and / or fracture of the bushing 5, thereby preventing or alleviating the shear damage of the ball stud 2 and the bearing shell 4 even at high temperatures. The knurling 6 is provided in the second opening portion 1.3, thereby further fixing the bushing 5, so that a larger axial force F can be supported.

[0126] The knurling 6 (third structural portion) may be arranged at other positions, or may be provided over the entire area of ​​the inner wall 1 . 1 . 1 of the housing 1 .

[0127] exist Figure 4 In, also with Figure 2 Similarly, the longitudinal axis A of the ball stud 2 is consistent with the longitudinal axis of the housing 1.

[0128] C. 3rd Implementation Method:

[0129] Figure 5 A longitudinal sectional view of the housing 1 is shown. Figure 6 Show that it has Figure 5 The ball joint of the housing 1. These are basically the same as Figure 1 and Figure 2 The implementation method is the same as Figure 1 and Figure 2The difference of the embodiment is that the housing 1 has a plurality of grooves 7 (here, three circumferential grooves 7) as the third structural element (structure c of claim 3). In this embodiment, these grooves 7 are provided in the second opening 1.3. The side angle β of the groove 7 is preferably not less than 50° and not more than 70°, and particularly preferably 60°.

[0130] Here, the third structural element is combined with the first step portion 1.9 (the fourth structural portion). Figure 1 and Figure 2 Similarly, the first step portion 1.9 is connected to the second opening portion 1.3 of the housing 1 and is formed to be 95° or more and 125° or less toward the first opening portion 1.2 (see Figure 1 ), preferably the first angle α1 of 110° (refer to Figure 5 ) is a shape expanding in the radial direction. The first step portion 1.9 has a convex curved portion having a large first radius r1. The first radius r1 is preferably between 1.0 mm and 6 mm, and particularly preferably between 2.0 mm and 4 mm.

[0131] In addition, Figure 1 and Figure 2 Similarly, the significant surface roughness / concavity (not shown) as the first structural element (structure a of claim 3 ) may be provided over a part or the entire area of ​​the inner wall 1 . 1 . 1 of the housing 1 .

[0132] When an axial force / pressing force F acts on the ball 3 of the ball stud 2 in the direction of the second opening 1.3 (refer to Figure 6 ), the first step portion 1.9 serves to prevent or delay the shear damage and / or fracture of the bushing 5, thereby preventing or delaying the shear damage of the ball stud 2 and the bearing 4 together even at high temperatures.

[0133] Since the second opening 1.3 has a plurality of grooves 7, the bushing 5 is further fixed, so that a larger axial force F can be received.

[0134] D. Modifications:

[0135] The technology disclosed in this specification is not limited to the above-mentioned embodiment, and can be modified into various forms within the scope not departing from the gist thereof. For example, the following modifications are also possible.

[0136] As an embodiment not shown in the figure, a screw-shaped spiral groove may be provided instead of the plurality of grooves 7 .

[0137] for Figures 1 to 6 The housing 1 shown can be manufactured by extrusion, forging, casting, etc., in combination with mechanical processing for forming structural elements on the inner wall 1.1.1.

[0138] As another embodiment of the present invention, after the ball stud 2 and the bearing shell 4 are fixed in the housing 1 by the bushing 5 , one or both ends of the housing 1 may be formed toward the radial inside.

[0139] Figure 7 1 is a longitudinal sectional view of a preform 1V of a housing 1. The preform 1V is formed into a substantially cylindrical shape, and has a cavity 1.1 and a first opening 1.2 provided in a first edge region 1.4 at the lower side of the figure, and an undercut 1.4.1 (which is in contact with the outer periphery of the first edge region 1.4) is provided. Figures 1 to 6 The inner side of the first opening 1.2 is associated with the second radius r2, and the second radius r2 is preferably between 5 mm and 12 mm, and particularly preferably between 6 mm and 9 mm, as in the above-mentioned embodiment of the shell 1. The second radius r2 is associated with the cylindrical portion 1.6, which extends to the opening 1.3V on the opposite side of the preform 1V. On the outside of the second radius r2, the bottom cut 1.4.1 of the first edge area 1.4 is connected to the first shoulder 1.7. As it moves toward the opening 1.3V, an outer diameter D1 substantially corresponding to the outer diameter of the rear shell 1 extends after the first shoulder 1.7. Then, as it moves toward the opening 1.3V, there is a slope 1SV in the outer contour of the preform 1V, and the slope 1SV has an angle γ of, for example, preferably greater than 20° and less than 90°, and particularly preferably greater than 30° and less than 60°, so that the outer contour starts to decrease from the outer diameter D1. There is a third radius r3V of 0.3 mm or more and 3 mm or less on the end surface.

[0140] Afterwards, a subassembly consisting of the ball stud 2 and the bearing 4 is inserted from the opening 1.3V into the area on the side opposite to the first opening 1.2 of the preform 1V, so that the ball 3 and the bearing 4 are located in the cavity 1.1, and then the preform 1V is formed radially inward.

[0141] Figure 8A preform 1V of a housing 1 is shown inserted into a forming die 10 together with a subassembly consisting of a ball stud 2 and a bushing 4 with a ball 3 mounted on the ball stud 2. In this case, since the ball 3 is accommodated together with the bushing 4 in the cavity 1.1 of the preform 1V, a gap is generated between the inner wall 1.1.1V of the preform 1V, the outer contour of the bushing 4, and the portion of the ball 3 that protrudes from the bushing 4. Only the unillustrated polar regions of the bushing 4 and the ball 3 protrude slightly from the end surface side region of the opening 1.3V. The ball stud 2 with the bushing 4 mounted on the ball 3 is inserted into the cavity 1.1 of the preform 1V together with the pin 2.1 from the opening 1.3V. The forming die 10 has a first lower body 11.1, and a first shoulder 1.7 of the preform 1V is placed on the first lower body 11.1 to support it during forming. The second lower body 11.2 (which may also be formed by a plurality of parts in the form of a slider) arranged radially inwardly of the first lower body 11.1 is formed in the direction of the pin 2.1 of the ball stud 2 and is separated from the first edge portion 1.4 to form a gap for the bushing 5. The roughly cylindrical outer periphery of the preform 1V is fixed by the annular support body 12. In addition, the upper body of the double-component structure composed of the first upper body 13 and the second upper body 14 arranged inside the first upper body 13 is also set in an open state here. The first upper body 13 has a first forming profile 13.1 indicated by a thick line in the direction of the preform 1V. The second upper body 14 also has a second forming profile 14.1 indicated by a thick line on the radially outer side in the direction of the preform 1V. The first forming profile 13.1 and the second forming profile 14.1 are as shown Figure 8 Furthermore, the second upper body 14 has a shaping contour 14 . 2 , indicated here by a thick dashed line, in the direction of the ball stud 2 , and an injection port 15 for injecting the bushing 5 .

[0142] When the subassembly consisting of the ball stud 2 and the bearing bush 4 is inserted into Figure 8 After that, the first and second upper bodies 13 and 14 are moved together toward the first and second lower bodies 11.1 and 11.2, and the forming die 10 is closed while a forming force is applied. By this forming force, the preform 1V is formed radially inwardly by the forming profiles 13.1 and 14.1 in the area opposite to the first and second upper bodies 13 and 14. In this forming process, the inclined surface 1SV (refer to Figure 7 ) plays a beneficial role.

[0143] Fig. 9 Also shown are the housing 1 formed from the preform 1V in the forming tool 10 and the ball stud 2 with the bearing shell 4 mounted on the ball 3 .

[0144] In order to encapsulate the area formed radially inward, the second upper body 14 is formed in the direction of the thick arrow (see Fig. 9 ) direction, so that the adjacent forming profiles 13.1 and 14.1 are separated from each other by a dimension h (refer to Fig.10 ) amount. A major advantage here is that the formed area can be elastically restored. Thus, after the forming die 10 is opened, no stress is applied to the bushing 5.

[0145] Then, if Fig.10 As shown, the bushing 5 is injected into the cavity 1.1 from the injection port 15 (see Fig. 9 ). The cavity 1.1 is formed between the bearing 4 / ball 3 and the inner wall 1.1.1 of the housing 1, and between the molded contour of the molding die 10 and the housing 1. In this case, the molded contour 14.1 of the second upper body 14 forms a molded contour for injection molding together with the contour 14.2. The bushing 5 fixes the ball 3 of the ball stud 2 mounted with the bearing 4 in the housing 1, and the first edge area 1.4 is rubber-coated in the range to the shoulder 1.7. Furthermore, the polar area of ​​the bearing 4 is rubber-coated, and the area formed radially inward of the second opening 1.3 of the housing 1 is also rubber-coated.

[0146] Fig.11 The ball joint after being pulled out from the forming die 10 is shown. The second opening 1.3 of the housing 1 is connected to the second step 1.10 by utilizing the area formed radially inward of the second opening 1.3, and the second step 1.10 preferably has a third angle α3 between 80° and 140°. At the second step 1.10, the concave third radius r3 (2 mm and 9 mm) continues, and the third radius r3 transforms to the inner diameter d1.6 of the cylindrical portion 1.6 of the cavity 1.1 of the housing 1. Here, the second step 1.10 functions as the fourth structural element (structure d of claim 3), thereby preventing the bushing 5 from breaking or the ball stud 2 from being separated from the ball 3 and the bearing shell 4 of the ball stud 2 when the axial force / thrusting force F is applied, thereby preventing the ball joint from being damaged.

[0147] Insert the ball stud 2 together with the bushing 4 mounted on the ball 3 into the larger opening 1.3V (refer to Figure 7 ), the second opening portion 1.3 of the shell 1 formed radially inward becomes smaller than the outer diameter of the ball 3 by forming the second opening portion 1.3 formed radially inward, so that an overlap b is generated between the first opening portion 1.2 and the second opening portion 1.3 of the shell 1 and the outer diameter of the ball 3, thereby preventing the ball 3 from detaching from the shell 1.

[0148] In addition, as an embodiment not shown in the figure, significant surface roughness / convexoconcavity (structure a of claim 3) and / or grooves / recesses and / or knurling (structure c of claim 3) can be provided on the inner side of the preform 1V of the shell 1 before forming.

[0149] In addition to the embodiments shown and described above, the components of the housing 1 can be combined with each other in any desired manner.

[0150] According to the above embodiment, the bushing 5 and the housing 1 are well fixed by utilizing the structural portion of the housing 1 , and therefore the ball joint can also withstand a high temperature region of 80° C. or above.

Claims

1. A ball joint comprising a housing having a cavity for accommodating a ball of a ball stud, wherein the ball is movably supported in a bearing bush, wherein: The housing has a first opening in a first edge region in a direction toward the pin of the ball stud, the ball stud protrudes from the first opening, and a gap is provided between the inner wall of the housing and the outer wall of the bearing shell, and a bushing is injected into the gap. Furthermore, the housing has a second opening in a second edge region opposite to the first opening, the second opening being used to inject the bushing through the cavity, and the second opening being larger than the outer diameter of the bearing bush. Furthermore, in the housing, The second edge region is formed in a protrusion shape extending further in the axial direction than the lower portion of the housing. The bushing covers the second edge area in a rubber-encapsulated manner, Furthermore, the housing has one or more structural elements for fixing the bushing on the inner wall of the housing. Furthermore, the housing has one or more grooves or recesses and / or knurling for fixing the bushing to the inner wall of the second opening. A step portion is formed between the one or more grooves or recesses, and / or knurling and the structural element, and the step portion expands in the radial direction toward the first opening. The one or more grooves or recessed portions, and / or knurling are formed in a region of the second opening portion ranging from the step portion to the second edge region.

2. The ball joint according to claim 1, characterized in that The structural element is disposed between the second opening and the equatorial region of the ball, and the second opening is used to embed a subassembly consisting of the ball stud and the bearing bush mounted on the ball into the housing.

3. The ball joint according to claim 1 or 2, characterized in that: The structural elements include the following structures a) to c) individually or in any combination, a) at least a portion of the inner wall of the housing has significant surface roughness or unevenness; b) the volume of the bushing increases toward the second opening; c) One or more grooves or recesses, and / or knurling are formed on the inner wall of the housing alone or in any combination.

4. The ball joint according to claim 3, characterized in that The arithmetic mean roughness Ra of the inner wall of the housing is greater than or equal to 10 μm and less than or equal to 75 μm.

5. The ball joint according to claim 4, characterized in that The arithmetic mean roughness Ra of the inner wall of the housing is greater than or equal to 10 μm and less than or equal to 63 μm.

6. The ball joint according to claim 3, characterized in that: The volume of the bush increases toward the second opening, so that the wall thickness of the bush becomes maximum in the region of the step portion.

7. The ball joint according to claim 3, characterized in that: At least one spiral groove is formed on the inner wall of the shell, and / or a plurality of grooves or recesses are formed in a manner of being separated from each other or intersecting each other, and / or knurling is formed.

8. The ball joint according to claim 1, characterized in that The housing has a wall portion curved radially inward in the region of the second opening.

9. The ball joint according to claim 1, characterized in that The depth of the one or more grooves or recessed portions and / or knurling in the region of the second opening is 0.3 mm to 1.5 mm.

10. The ball joint according to claim 1, characterized in that The first edge region of the housing is formed in a protrusion shape extending in the axial direction, and the bush covers the first edge region.

11. The ball joint according to claim 1, characterized in that The ball of the ball stud has a recessed portion in a pole region, and the projection of the bearing shell engages with the recessed portion.

12. A method for manufacturing a spherical joint, the spherical joint being the spherical joint according to claim 1, characterized in that: Including the following processes: forming one or more of the structural elements on the inner wall of the shell; Before or after the forming of the structural element, a subassembly consisting of the ball stud and the bearing shell mounted on the ball is embedded in the housing; Next, the bushing is injected into the gap between the subassembly and the inner wall of the housing.

13. The method for manufacturing a ball joint according to claim 12, characterized in that: Before the ball stud is embedded in the housing and before the bushing is injected, at least a portion of the inner wall of the housing is machined to have significant surface roughness or unevenness, and / or one or more grooves or recesses, and / or knurling are produced on the inner wall of the housing by machining.

14. The method for manufacturing a ball joint according to claim 12 or 13, characterized in that: In the housing, the second opening is formed radially inwardly so as to be connected to a step portion that expands in the radial direction toward the first opening.

15. The method for manufacturing a ball joint according to claim 12, characterized in that: One or more of the structural elements are formed on the inner wall of the housing by a forming method such as extrusion forging, bending, or upsetting to form the housing radially inward.

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