Method for producing a camshaft adjuster and camshaft adjuster

Abstract

The invention relates to a method for producing a camshaft adjuster (100) for a camshaft of an internal combustion engine, the camshaft adjuster having a rotor (110), a stator (120) and at least one cover (130), wherein the method comprises the following steps: arranging at least one cover (130) on the stator (120) and welding the cover (130) to the stator (120), wherein during the welding a weld seam (140, 141, 142) is formed on at least one large radius (134) and / or on a small radius (133), and wherein the small radius (133) is smaller than the large radius (134). The invention also relates to a camshaft adjuster (100) for a camshaft of an internal combustion engine, the camshaft adjuster having a rotor (110), a stator (120) and at least one cover (130).

Description

Technical Field

[0001] The invention relates to a method for producing a camshaft adjuster for an internal combustion engine, the camshaft adjuster having a stator, a rotor and at least one cover. The invention also relates to a camshaft adjuster for a camshaft of an internal combustion engine, the camshaft adjuster having a rotor, a stator and at least one cover. Background Art

[0002] Camshaft adjusters are used essentially in valve trains of internal combustion engines in order to be able to set the phase relationship between the crankshaft and the camshaft in an optimal and variable manner. In this case, a pressure chamber is formed between the stator and the rotor, which is covered from the environment by means of at least one cover. In this case, the cover is usually connected to the stator by means of a screw connection, but in some cases also by means of a welded connection.

[0003] A disadvantage of the known camshaft adjuster is, in particular in welded camshaft adjusters, an undesirable deformation of the cover, more precisely an outward bulging, which occurs due to the high pressure in the pressure chamber. In addition, the known camshaft adjuster is complex in its manufacture. Summary of the invention

[0004] It is therefore the object of the present invention to make a camshaft adjuster of the type mentioned in the introduction more stable and to improve it structurally and functionally and to facilitate its production.

[0005] This object is achieved in particular by a method for producing a camshaft adjuster for a camshaft of an internal combustion engine, wherein the camshaft adjuster has a rotor, a stator and at least one cover part, wherein the method comprises the following steps: arranging at least one cover part on the stator and welding the cover part to the stator, wherein during welding, the weld seam is formed on at least one large radius and / or on a small radius, and wherein the small radius is smaller than the large radius.

[0006] The cover serves to shield the pressure chamber between the stator and the rotor from the environment. Since, according to the invention, the weld seam is provided at least on the large radius and the small radius for connecting the stator and the cover, a more stable camshaft adjuster is achieved.

[0007] The weld seams on the large radius are located on a common circular path, and the weld seams on the small radius are located on a common smaller circular path. In addition to the weld seams on the small radius and the large radius, other weld seams can also be configured on other radii that have sizes different from the large radius and the small radius.

[0008] In particular, the weld seam on the small radius ensures that the cover is also securely fastened to the stator at a position further inwardly located in the radial direction. Therefore, the cover no longer tends to bulge outwards due to the high pressure in the pressure chamber.

[0009] The cover is preferably at least substantially disk-shaped. In short, for example, in addition to the weld seams arranged on the outer circumference, a weld seam promoting stability is also configured at a more internal position.

[0010] The stator is preferably made of a sintered material, for example a carbon-containing sintered steel having a carbon content between 0.2% and 0.9%, in particular between 0.5% and 0.8%, in particular 0.6%. The cover is preferably made of a non-sintered material, for example steel having a carbon content of maximum 0.2%.

[0011] In an advantageous development, the circumferential weld seam is designed to be continuous over a large radius.

[0012] This means that the weld seam is configured as a continuous, ie uninterrupted, weld seam on a large radius. Here, a particularly stable connection is obtained between the cover and the stator.

[0013] In a particularly advantageous development, the weld seam is formed on the large radius and the weld seam is formed on the small radius. The stability of the connection is high enough by the radially inner region to effectively prevent the thin cover from bulging.

[0014] In a particularly advantageous development, a circumferential weld seam is formed which has a weld seam at a large radius and a weld seam at a small radius.

[0015] In other words, the weld seam on the large radius and the weld seam on the small radius are designed to be connected to each other. Preferably, the circumferential weld seam then extends along the outer circumference of the cover. The outer circumference of the cover is not circular, but also has an area that is located radially more inward than the outer circumference. Particularly preferably, the circumferential weld seam is also designed to be continuous. Overall, a particularly fast and not very complicated welding of the cover on the stator can be carried out here. Due to the radially inner area, the stability of the connection is still high enough to effectively prevent the cover from bulging.

[0016] According to a preferred development, the circumferential weld seam, viewed in the direction of the axis of rotation of the rotor, is designed at least substantially along a cloverleaf-shaped line.

[0017] The weld seam is in particular designed as a multi-leaf clover leaf. For example, the weld seam can be designed as a three-leaf, four-leaf or five-leaf clover leaf. The number of clover leaves depends on the functional requirements of the camshaft adjuster. The clover leaf shape produces a particularly stable connection between the cover and the stator.

[0018] In an advantageous development, the weld seam at the small radius is designed separately from the weld seam at the large radius.

[0019] Then, for example, it is possible to form the weld seam only in a point-shaped manner on a small radius. Then, the shape of the cover can also be configured less complexly, so that costs can be saved here.

[0020] According to an advantageous development, the weld seam is formed on a small radius.

[0021] For example, the weld seam can be formed only on a small radius. This can save costs and at the same time prevent the cover from expanding.

[0022] According to a preferred development, the weld seam at the small radius is arranged and fastened on the radially inwardly extending blades of the stator.

[0023] Preferably, a plurality of blades are arranged on the stator. For example, three, four or five blades can be constructed on the stator. The blade or blades extend radially inward from the annular body of the stator. Since the blades are the radially most inwardly extending areas of the stator, these blades are particularly suitable for constructing welds on small radii thereon.

[0024] Particularly preferably, the weld seam is arranged and fastened on a small radius on the inwardly directed ends of the blades of the stator. Therefore, the weld seam is fastened on the innermost point of the stator.

[0025] According to a further advantageous development, the holes are formed on the vanes of the stator extending radially inwards.

[0026] The additional fastening of the cover on the stator can be achieved at the hole. As a result, the fastening between the two components is particularly stable. Before the cover is arranged on the stator, that is, before welding, the hole is already introduced into the stator.

[0027] According to a preferred development, the weld seam is formed on a smaller radius which is closer to the axis of rotation of the rotor than the opening.

[0028] Therefore, the hole is located on a radius greater than the small radius. Therefore, the weld seam on the small radius is arranged at a position particularly close to the inner structure.

[0029] According to an advantageous development of the invention, the weld seam has a radial weld seam region which extends at least substantially radially relative to the axis of rotation of the rotor.

[0030] In an advantageous development, the radial weld seam region connects the weld seam on the small radius to the weld seam on the large radius.

[0031] Therefore, the radial weld seam area bridges the radial offset between the weld seam on the small radius and the weld seam on the large radius. The radial weld seam area does not have to be configured exactly in the radial direction. It is sufficient that these weld seam areas realize a radius change of the weld seam.

[0032] For example, the above-mentioned continuous circumferential weld seam can be formed in this way.

[0033] According to an advantageous development, the welding is performed by means of laser welding, wherein a laser beam is applied to the first joining region of the cover in order to melt it into a melt, and wherein the second joining region of the stator is melted by means of the melt of the first joining region.

[0034] The welding method is therefore particularly noteworthy since the elements to be welded, as mentioned at the outset, can be sintered materials and non-sintered materials.

[0035] The sintered material in the second joining area is then melted by the first joining area with the help of the melt of the non-sintered material. The sintered material does not come into contact with the laser beam at any point in time. The laser beam is only applied to the non-sintered material or coupled into the non-sintered material. This can therefore also be described as indirect laser welding.

[0036] This brings the advantage that a stable and mass-producible welded connection is produced between the non-sintered material and the sintered material in a simple manner. In addition, the laser welding method can be used very flexibly for different geometries of the components to be joined, which in turn significantly reduces the process and / or manufacturing costs.

[0037] For the sake of a better understanding, the terms contact plane, joint and joint region should be explained in more detail here.

[0038] The contact plane is a virtual surface on which two components to be joined are placed in order to be welded to each other. Thus, during the welding process, the first component is arranged on one side of the contact plane and the second component is arranged on the other side or the opposite side of the contact plane. In this case, the two components are at least partially placed against each other. In this case, the two components form a joint.

[0039] A joint can be understood to be a contact edge which extends along the outer edge section of the two components, on which the components abut one another. Here, the outer edge section of one component can either rest on the outer surface of the other component which extends beyond the outer edge of the component, or end flush with the outer edge section of the other component. Two joining regions extend over the joint, more precisely a first joining region of the first component and a second joining region of the second component.

[0040] The joining region is the part or section of the component that is directly involved in the welding process. In the case of a first component made of a non-sintered material, this is the part that is converted into a melt when the laser beam is applied. In the case of a second component made of a sintered material, this is the part that is melted by means of the melt of the first joining region, thereby fusing or connecting the two joining regions to each other.

[0041] The laser beam is applied by means of a continuous or pulsed laser beam. Preferably, this application is carried out by means of laser beam-MSG hybrid welding. Laser beam-MSG hybrid welding is a combination of laser beam and MSG welding processes in a common process zone (MSG = metal shielding gas welding). The advantages of both methods are utilized here. Very deep burns with good lateral bonding are achieved. In this case, very narrow heat-affected zones are formed with little distortion. The process allows very high welding speeds, which leads to low path energies. The main reason for the high economy is the reduced weld preparation. Entire work steps can be omitted.

[0042] According to a preferred development, the laser beam is oriented during application parallel to a contact plane along which the cover and the stator are arranged for producing the joint.

[0043] As a result, the laser beam can exert its maximum effect and energy losses can be avoided.

[0044] Furthermore, the laser beam can be oriented during application at an angle α relative to the contact plane, wherein the angle α is a maximum of 45°, in particular a maximum of 30°, in particular a maximum of 15°.

[0045] The following applies here: The less the laser beam deviates from the orientation parallel to the contact plane or the less the angle α deviates from 0°, the more intensely the laser beam exerts its effect. However, deviations of the angle α from 0° may be unavoidable, for example, if the first joining region cannot be reached with a laser beam oriented parallel to the contact plane due to structural conditions. Up to an angle of a maximum of 45°, the laser beam can still exert a sufficient effect to melt the joining region of the first component.

[0046] The angled orientation of the laser beam is particularly suitable if the outer edge section of one component to be joined is placed on the outer surface of the other component beyond its outer edge. Thus, the risk of applying the laser beam to the second component is minimized or only fully achieved by applying the laser beam to the first joining area.

[0047] In an advantageous development, a preferably circumferential groove is formed in the cover and / or in the stator before welding.

[0048] In the finished component, one or more grooves can be filled with the cooled and thus solidified melt from the first joining region. As a result, the joining regions of the two components fuse together particularly well and the resulting composite is particularly stable. In particular, the resulting composite can withstand shear forces particularly well. In addition, the grooves also have the advantage that gases generated during the welding process can be discharged. These gases can interfere with clean welding, so that a better welded connection is produced by the discharge. In addition, the porosity of the weld seam is smaller.

[0049] Particularly advantageously, the circumferential groove on the stator can be connected to a radial groove, which connects the circumferential groove to a hole formed on the blade of the stator. If a plurality of blades are arranged, then the corresponding plurality of holes are also connected to the circumferential groove via the associated radial groove. This results in a particularly good discharge of the gas.

[0050] According to a further aspect, the object is achieved by a camshaft adjuster for a camshaft of an internal combustion engine, the camshaft adjuster having a rotor, a stator and at least one cover part, wherein the cover part and the stator are produced according to one of the methods described above.

[0051] All aspects discussed above with respect to the method apply here. Accordingly, the same advantages are obtained here as in the method according to the invention.

[0052] In an advantageous development, the cover has a material thickness of less than 6 mm, preferably less than 5 mm, preferably less than 4 mm, preferably less than 3 mm and particularly preferably less than 2 mm.

[0053] The smaller the material thickness of the cover is, the more material, weight and installation space can be saved in the camshaft adjuster. In addition, the corresponding material saving has a cost-effective effect. The welding of the cover with a material thickness of only 2 mm or less can be achieved in particular by means of laser welding or projection welding.

[0054] According to an advantageous development of the invention, the stator is welded to two covers, wherein one cover is arranged on the side of the stator facing the camshaft and the other cover is arranged on the side of the stator facing away from the camshaft.

[0055] The welding can be performed simultaneously. Here, the electrodes are respectively applied externally to the cover parts or a laser beam is directed on the two cover parts as described above. As a result, the welding of the cover parts is particularly effective.

[0056] According to another aspect, the object is achieved by a camshaft adjuster for a camshaft of an internal combustion engine, the camshaft adjuster having a rotor, a stator and at least one cover part, wherein the weld between the stator and the at least one cover part is constructed on at least one large radius and a small radius, and wherein the small radius is smaller than the large radius, wherein preferably a circumferential weld is constructed, which has a weld on the large radius and a weld on the small radius and is preferably constructed at least essentially in a cloverleaf shape when viewed in the direction of the rotation axis of the rotor.

[0057] As a result, a particularly stable camshaft adjuster can be provided, wherein during operation a bulging of the cover part is very effectively prevented.

[0058] According to another aspect, the object is achieved by a camshaft adjuster for a camshaft of an internal combustion engine, the camshaft adjuster having a rotor, a stator and at least one cover part, wherein the weld seam between the stator and the at least one cover part is constructed on at least one large radius and a small radius, and wherein the small radius is smaller than the large radius, and wherein the weld seam on the large radius and the weld seam on the small radius are constructed to be separated from each other.

[0059] Other designs of the present invention are described below. The aspects described below can also be combined with the designs described above and their various aspects.

[0060] Another embodiment of the invention relates to a method for producing a camshaft adjuster for an internal combustion engine, the camshaft adjuster having a stator, a rotor and at least one cover. The method comprises the following steps: providing a cover having at least one welding contour, placing the welding contour against the stator, and welding the cover to the stator at the welding contour.

[0061] According to an advantageous development, the welding is carried out by means of projection welding or laser welding.

[0062] Projection welding is a specific form of resistance welding and is therefore essentially a welding method for electrically conductive materials based on Joule current heat of an electric current flowing through the connection. The connection pair, here the stator and the cover, are heated until the welding temperature is reached and welded to the connection by solidification of the melt, by diffusion or in the solid phase under the action of force. The advantage of resistance welding is the particularly high welding speed. In projection welding (also called resistance projection welding), the connection (i.e., the welding contour) is configured in a point shape by means of projections or so-called projections. This has the advantage that the current density required for welding is not generated by the electrode, but by the shape of the component, i.e., by the projection or projection. The electrode is used here for power supply and force introduction. With the help of projection welding, welding can be performed particularly quickly. This, for example, has a very good protective material effect on the cover, which can thus be constructed with a very small material thickness.

[0063] The projection is preferably designed in the form of a point. After the cover is placed, it is connected to the stator only via the at least one projection. Furthermore, the projection is preferably surrounded by a depression, which is in particular circular, which directly connects to the projection. The projection according to the invention is therefore to be understood ideally as a cone protruding from the depression, also referred to here as a projection. The cover rests on the stator at the point at which the tips of the cone converge, in order to weld the cover to the stator.

[0064] The described method for producing a camshaft adjuster has the advantage that welding can be carried out very quickly and without additional welding material, such as welding wire. An improved joining of the cover to the stator can be achieved by means of the recess.

[0065] In a particularly advantageous development, capacitor discharge welding is also used during projection welding on this basis. Capacitor discharge welding, KE welding for short, also known as capacitor pulse welding, differs from conventional resistance welding in the way the energy is generated and is used in particular in projection welding. The energy is output from the charged capacitor via a welding transformer to the connection partner. The charging current can be several orders of magnitude smaller than the subsequent discharge current, so that pulse loading of the power grid and, if necessary, overloading thereof can be avoided. As a result, no high current peaks are generated in the power grid lines. This makes the production method more efficient.

[0066] In another preferred development, the welding is performed by means of laser welding. Due to the small material melt and the controllable melting time, laser welding can be used to connect materials that are difficult to weld with conventional welding methods or cannot be welded at all. Although laser welding is slower than the aforementioned resistance welding, it has the advantage that welding can be performed on one side or from one side. This means that no matching parts, such as electrodes arranged behind the connection partner, are required. Laser welding also has the advantage that the connection partner does not necessarily have to be produced with an electrically conductive material.

[0067] Furthermore, it is advantageous that laser welding allows variable welding geometries with narrow weld seam shapes and can join the components with little thermal distortion. The method can also be carried out with or without additional material.

[0068] According to the invention, during welding, the cover and the stator are advantageously pressed against each other with a pressure, in particular between 10 kN and 40 kN, the pressure depending on the size of the components. Such a high pressure promotes the flow of current between the cover and the stator at the connection point. This additionally accelerates welding.

[0069] In another advantageous refinement, welding is performed from the outside through the cover. The outside of the cover or the side facing away from the stator is particularly accessible to the welding device, for example its electrodes. In this way, the production of the camshaft adjuster is greatly simplified.

[0070] In a particularly advantageous embodiment, welding is performed along the outer edge of the cover on a plurality of welding contours. Here, for welding, preferably annular edge welding is used as a special form of projection welding.

[0071] Furthermore, preferably, all welding contours are welded simultaneously along the outer edges. In particular, a separate or individual electrode pair is attached to each welded connection to be produced. As a result, welding is particularly effective.

[0072] According to another preferred improvement, welding is performed on a plurality of welding contours arranged at intervals from each other. During welding, gaps are generated and no continuous weld seams or weld lines are generated. This saves energy and work consumption.

[0073] Preferably, welding is performed on a plurality of welding contours, which are located on a common circular path. Due to the circular arrangement of the welding contours, the welded connection obtained between the connection partners is particularly stable. In addition, the circular path can be arranged along the outer edge of the cover or further inside the cover surface.

[0074] In an advantageous development, welding is performed with the blades of the stator on at least one welding contour. The cover can thus be connected to the stator by welding at least in the region between two blade chambers. Each welded connection is thus surrounded by a relatively large supporting surface of the cover on the stator, which has a favorable effect on the stability of the connection. A high stability of the connection is necessary because oil pressures of up to 50 bar or even briefly exceeding 50 bar can act on the cover starting from the blade chamber.

[0075] Furthermore, the cover is preferably made of an electrically conductive material. This has a favorable effect on the feasibility of welding between the cover and the stator. For example, the cover and the stator are produced by means of a projection welding method and the welding contour is formed by the projection. In this case, an electrically conductive material is preferably used in the cover.

[0076] Alternatively, the cover and the stator can be welded together by means of a laser welding method, wherein the welding contour is formed by a circumferential weld seam or a plurality of weld seams.

[0077] Further advantages of the invention will emerge from the description and the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0078] The invention is explained in more detail below with reference to the exemplary embodiments shown in the accompanying drawings.

[0079] Figure 1 A first embodiment of a camshaft adjuster according to the invention produced by a method according to the invention is shown.

[0080] Figure 2A second embodiment of a camshaft adjuster according to the invention produced by the method according to the invention is shown.

[0081] Figure 3 Show Figure 2 A view of the cover part of the camshaft adjuster of the second embodiment of the invention, and

[0082] Figure 4 A view of a stator of a camshaft adjuster is shown in a first and a second embodiment. DETAILED DESCRIPTION

[0083] Figure 1 A first specific embodiment of a camshaft adjuster 100 according to the invention is shown, which is produced according to the production method according to the invention.

[0084] The camshaft adjuster 100 has a rotor 110. Figure 1 and Figure 2 Only the inner part of the rotor is shown in FIG. The rotor 110 is configured to be rotatable relative to the stator 120 of the camshaft adjuster 100. The stator 120 of the camshaft adjuster 100 is Figure 4 As shown in more detail in and with reference to Figure 4 Describe in more detail.

[0085] A cover 130 is arranged on the stator 120. The cover 130 is disk-shaped or disk-shaped. The cover 130 is configured to cover the pressure chamber between the stator 120 and the rotor 110. Therefore, a high pressure acts on the cover 130. This pressure may cause the surface area of ​​the cover 130 to bulge outward. In order to prevent this, the cover 130 is welded to the stator 120 in a special way. In particular, the cover 130 is welded to the stator 120 on a small radius 133 and a large radius 134, wherein the term radius is related to the cover 130. Therefore, the circumferential weld 140 is not only configured on the outer radius of the cover 130, but also configured more internally.

[0086] The circumferential weld seam 140 has a weld seam 142 at a small radius 133 and a weld seam 141 at a large radius 134 . The large radius 134 corresponds to the outer radius of the cover 130 .

[0087] Furthermore, the weld seam 140 has a radial weld seam region 143 between the weld seam 141 and the weld seam 142, which respectively connects the weld seam 141 at the large radius 134 and the weld seam 142 at the small radius 133. The radial weld seam region 143 thus bridges the radial offset between the weld seam 141 and the weld seam 142. In this case, the radial weld seam region 143 does not have to be formed exactly in the radial direction. This is sufficient to achieve a radius variation of the circumferential weld seam 140.

[0088] exist Figure 1 In the embodiment, the circumferential weld seam 140 is formed continuously, ie without interruption.

[0089] The stator 120 has a plurality of blades 121. The blades 121 extend radially inward from the annular body 125 of the stator 120. Therefore, the blades 121 are particularly suitable for forming the weld seam 142 on the blade on the small radius 133. Figure 1 The center weld seam 142 is arranged on the small radius 133 on the blades 121 .

[0090] exist Figure 1 , Figure 2 and Figure 4 In the figure, a stator 120 with four blades 121 is shown. However, the stator 120 can also have a different number of blades 121, for example three or five blades 121. Accordingly, a different number of weld seams 142 on the small radius 133 is also conceivable. Here, four weld seams 142 are formed on the small radius 133. In this case, each of the weld seams 142 is assigned to one of the four blades 121. Accordingly, the four weld seams 141 are also arranged in the area between the blades 121.

[0091] The circumferential weld seam 140 consisting of weld seams 141, 142 and 143 is designed at least substantially in the shape of a cloverleaf when viewed in the radial axis direction of the rotor R. The weld seam 140 is designed in particular here like a four-leaf clover leaf. Each individual clover leaf is constructed here by a weld seam 141 on a large radius 134 and two adjacent radial weld seam regions 143. The individual clover leaves are then connected by one of the weld seams 142 on a small radius 133.

[0092] Figure 2 A second embodiment of a camshaft adjuster 100 according to the present invention is shown. Figure 1 The first embodiment of the present invention has some commonalities. These commonalities will not be described in detail, but can be transferred to Figure 2 In particular, the rotor 110 and the stator 120 are constructed identically. Therefore, Figure 2 The description focuses on Figure 1 The embodiments shown in FIG.

[0093] Figure 2Although the cover 130 in the embodiment is also disc-shaped, it is not cloverleaf-shaped. Instead, the cover 130 is configured as an annular disc and has a plurality of recesses 131. The cover 130 is arranged above the stator 120 so that the recesses 131 are respectively arranged above one of the blades 121. Corresponding to the number of blades 121, four recesses 131 are also configured here. Of course, other numbers of blades 121 and recesses 131 can also be configured here. Merely by way of example, three, five or six elements can be arranged respectively.

[0094] The inwardly directed edge of the recess 131 is located on the small radius 133, so that a weld seam 142 is arranged there. The weld seam is also arranged on the opposite edge, that is, on the edge that is directed outward. In addition, a weld seam is also formed between two edges in the radial weld seam region 143. Overall, the inner circumference of the recess 131 is thus connected to the stator 120 by means of a continuous weld seam. Therefore, the continuous weld seam has the shape of the recess 131 in cross section, that is, in the direction of the axis of rotation of the rotor 110.

[0095] In this exemplary embodiment, the weld seam 141 on the large radius 134 and the weld seam 142 on the small radius 133 are designed separately from one another.

[0096] The weld 141 on the large radius 134 is Figure 2 The weld seam 140 is designed as a circumferential weld seam 140. The weld seam 140 extends on the outer radius of the disk-shaped cover 130.

[0097] In one embodiment (not shown), the weld seam 140 is provided as a continuous weld seam only on the large radius 134. In this case, the recess 131 is not welded to the stator 120. The seal is achieved here only by supporting the cover 130 on a contact surface of the stator 120, which is preferably ground beforehand.

[0098] It is also conceivable to provide the weld seam 142 only on the small radius 133 or to weld only around the recess 131 .

[0099] exist Figure 1 and Figure 2 , the camshaft adjuster 100 is shown from the side facing away from the camshaft. The cover 130 can also be arranged as described above from the side facing the camshaft. Here, the cover 130 is preferably designed as a closing plate or a closing disk, for example with a closing cap, on the side facing the camshaft, while the cover 130 is designed as a simple cover plate on the side facing away from the camshaft.

[0100] Figure 3 Show Figure 2FIG. 1 shows a cover 130 of a camshaft adjuster 100 of a second embodiment of the present invention. The recess 131, which is designed as an opening, can be clearly seen in the cover 130 again. In addition, the cover 130 has a circumferential groove 132. The circumferential groove 132 extends on a radius adjacent to the large radius 134. The groove 132 can therefore facilitate welding. In particular, gases can be discharged.

[0101] Figure 4 The stator 120 of the camshaft adjuster 100 in the first and second embodiments is shown. The stator 120 has four vanes 121 extending inwardly from an annular body 125. In each vane 121 a continuous opening or hole 122 is arranged.

[0102] A circumferential groove 123 is also formed on the stator 120. The circumferential groove 123 is formed on the same radius as the circumferential groove 132. Therefore, the radius of the circumferential groove 123 is also smaller than the large radius 134. The hole 122 is connected to the circumferential groove 123 via the radial groove 124. As a result, the gas can be discharged particularly well. During welding, the melt can also flow from the cover 130 into the radial groove 124, so that the connection is particularly good.

[0103] All features explained and shown in conjunction with the various embodiments of the present invention can be arranged in different combinations in the subject matter according to the present invention in order to achieve their advantageous effects at the same time. The scope of protection of the present invention is not limited by the features described in the description or shown in the drawings.

Claims

1. A method for producing a camshaft adjuster (100) for a camshaft of an internal combustion engine, the camshaft adjuster having a rotor (110), a stator (120) and at least one cover (130), the method comprising the following steps: - arranging the at least one cover (130) on the stator (120), and - welding the cover (130) to the stator (120), wherein during the welding, the weld seam (140) is formed on at least one large radius (134) and a small radius (133), and wherein the small radius (133) is smaller than the large radius (134), wherein a first weld seam (141) is formed on the large radius (134) and a second weld seam (142) is formed on the small radius (133), wherein the second weld seam (142) on the small radius (133) is arranged and fastened to the radially inwardly extending blades (121) of the stator (120), wherein holes (122) are formed on the radially inwardly extending blades (121) of the stator (120), wherein the second weld seam (142) on the small radius (133) is configured closer to the axis of rotation of the rotor (110) than the hole (122), The at least one cover (130) shields a pressure space between the stator (120) and the rotor (110) from the environment.

2. The method according to claim 1, wherein the weld seam (140) has a radial weld seam region (143) which extends substantially radially to the axis of rotation of the rotor (110).

3. The method according to claim 2, wherein the radial weld region (143) connects the second weld (142) on the small radius (133) with the first weld (141) on the large radius (134).

4. The method according to claim 1 , wherein the welding is performed by means of laser welding, and wherein a laser beam is applied to a first joining region of the cover ( 130 ) in order to melt the first joining region into a melt, and wherein a second joining region of the stator ( 120 ) is melted by means of the melt of the first joining region. 5 . The method according to claim 4 , wherein during the applying, the laser beam is oriented parallel to a contact plane along which the cover ( 130 ) and the stator ( 120 ) are arranged for producing the joint.

6. The method according to any one of claims 1 to 3 and 5, wherein a circumferential groove (123, 132) is formed in the cover (130) and / or the stator (120) before welding. 7 . The method according to claim 4 , wherein a circumferential groove ( 123 , 132 ) is formed in the cover ( 130 ) and / or the stator ( 120 ) before the welding.

8. A camshaft adjuster (100) for a camshaft of an internal combustion engine, the camshaft adjuster having a rotor (110), a stator (120) and at least one cover (130), wherein the cover (130) and the stator (120) are manufactured according to the method according to any one of claims 1 to 7. 9 . The camshaft adjuster ( 100 ) according to claim 8 , wherein the cover part ( 130 ) has a material thickness of less than 6 mm. 10 . The camshaft adjuster ( 100 ) according to claim 8 , wherein the cover part ( 130 ) has a material thickness of less than 5 mm. The camshaft adjuster ( 100 ) according to claim 8 , wherein the cover part ( 130 ) has a material thickness of less than 4 mm. 12 . The camshaft adjuster ( 100 ) according to claim 8 , wherein the cover part ( 130 ) has a material thickness of less than 3 mm. 13 . The camshaft adjuster ( 100 ) according to claim 8 , wherein the cover part ( 130 ) has a material thickness of less than 2 mm.

14. The camshaft adjuster (100) according to any one of claims 8 to 13, wherein the stator (120) is welded to two cover parts (130), wherein one cover part (130) is arranged on the side of the stator (120) facing the camshaft and the other cover part (130) is arranged on the side of the stator (120) facing away from the camshaft.

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