EP4673335A1

EP4673335A1 - Paddle shift lever with warpage prevention

Info

Publication number: EP4673335A1
Application number: EP24705423.2A
Authority: EP
Inventors: Saravanan Ramaraj; Eric Delmas; Kulandaivel PALANISAMY
Original assignee: Valeo Schalter und Sensoren GmbH
Current assignee: Valeo Schalter und Sensoren GmbH
Priority date: 2023-02-27
Filing date: 2024-02-13
Publication date: 2026-01-07
Also published as: CN120693266A; WO2024179831A1; DE102023104676A1

Abstract

The disclosure is concerned with a paddle shift lever (1) for a steering handle. The paddle shift lever (1) comprises a base component (2) with an operating portion (3a) and a connecting portion (3b). The base component (2) further comprises an insert part (4) and a shell part (5). The insert part (4) comprises a connecting element (4a) in the area of the connecting portion (3b) and a protrusion element (4b) in the area of the operating portion (3a). The shell part (5) is covering the insert part (4) at least in the area of the operating portion (3a), thus forming a housing for the insert part (4). Preferably, the insert part (4) and the shell part (5) are assembled or manufactured from plastic material using overmolding. To prevent warpage, the insert part (4) and the shell part (5) are being connected by means of an interlock structure (10, 10') in the area of the operating portion

Description

Paddle shift lever with warpage prevention

The disclosure is concerned with a paddle shift lever for a steering handle, such as a steering wheel of a vehicle. In addition, the disclosure is concerned with a steering handle for a vehicle comprising a respective paddle shift lever. Furthermore, the disclosure is concerned with a method for manufacturing a respective paddle shift lever.

A paddle shift lever or rocker switch is a control element for operating a sequential or automatic transmission or gear box in a vehicle. Typically, a paddle shift lever is mounted on the steering wheel of the vehicle. By operating the lever, the driver can select a transmission gear without having to take his hand off the steering handle. For example, one paddle shift lever may be mounted on the left and the right of the steering wheel, respectively. Operating one of the levers (e.g. the left) shifts down a gear, operating the other lever (e.g. the right) shifts up a gear.

For operating the lever, the driver may pull the lever towards him or towards the steering wheel, which triggers the gear shift. To do so, the driver may grip a side of the lever facing away from him, thus from behind and pull, while leaving his hand on the steering handle. However, other operation techniques, such as pushing or swiveling or pivoting in another direction, for example parallel to the steering handle may be possible as well.

To enable operation, the paddle shift lever comprises a protrusion or overhanging feature with regard to a mounting basis on the steering handle. That means that the lever may protrude a rim of the steering handle in a mounting position. The resulting protrusion can be referred to as operating portion or operating side of the lever. The mounting basis can be referred to as connection portion or connection side of the lever. In other words, the lever may comprise an operating portion for operating the lever, which exceeds or protrudes a connection portion for connecting or fastening the lever to the steering handle.

Such levers are known in principle. For example, WO 2019 223 911 A1 discloses a rocker switch with a base body and an insert element in the operating section of the base body. To ensure stability, the insert element is back-injected through the material of the base body and is connected to the base body by material bond with is formed from an endless- fiber-reinforced plastic material. Back-injection is a manufacturing method which can be performed by injection molding. Injection molding is a conventional, popular manufacturing process for producing workpieces by injecting molten material, such as thermoplastic material into a mold. Hereby, a molding tool uses semi-liquidous or viscous materials, to fill voids and cavities within the predefined mold, thus taking on the desired shape of the designed tooling or workpiece. After cooling, the workpiece or part can be ejected out of the corresponding injection mold.

When using plastic materials for molding, an undesired effect is a so-called warpage. Warpage occurs when the intended shape of the molded part is distorted during the cooling process. Mold warping can cause the part to fold, bend, twist or bow, for example. Warpage in a paddle shift lever as described before may result in degraded operability, undesired optics or an instability of the overhanging feature resulting in a reduced lifetime or susceptibility to defects.

It is an object of the present disclosure to provide a possibility for warpage prevention for manufacturing of a paddle shift lever.

The object is accomplished by the subject-matter of the independent claims. Advantageous developments with convenient and non-trivial further embodiments of the disclosure are specified in the dependent claims, the following description and the figures.

The disclosure is based on the realization that mechanical interlocks or interlocking features may be used in the assembly of a paddle shift lever to achieve better warpage results. According to one aspect, the disclosure of the invention proposes a paddle shift lever for a steering handle of a vehicle, such as a motor vehicle. The paddle shift lever, in the following abbreviated with lever, comprises a base component or base body with an operating portion or operating side for operating the lever, as described before. The base component comprises a connection portion for connecting or fastening the lever to the steering handle.

An insert or inlay part and a shell part form the base component. The insert part comprises a connecting element in the area of the connection portion. The connecting element provides a physical connection to the steering handle, in particular a corresponding connecting element of the steering handle. In addition, the insert part comprises a protrusion element forming a protrusion or overhanging feature relative to the connecting element in the area of the operating portion. Thus, the operating portion of the paddle shift lever protrudes the connection portion.

The shell part is covering the insert part at least in the area of the operating portion. That means, the shell part can be a housing or envelope or cover for the insert part, at least partially. Preferably, the shell part may cover the insert part in the area of the operating portion and the connection portion. In this case, the shell part may comprise an opening in the area of the connection portion for the connecting element. Thus, the connecting element may be guided out of the housing provided by the shell part through the opening.

The insert part and the shell part are being connected by means of or via an interlock structure in the area of the operating portion. In other words, the shell part and insert part are connected by means of interlocking, for example, using one or more corresponding interlock elements. Thus, the insert part and the shell part may be dovetailed or intermeshed by the interlock structure. In addition, optics of the lever are upgraded, resulting in a high quality impression for a user. The effectiveness of warpage reduction or prevention by using interlocks was shown in a rheology simulation with a suitable simulation tool, for example Mold Flow®.

The interlock structure provides high stability and torsional rigidity, especially in the operating portion. This results in a stabilizing or shape-holding effect for the overhanging feature. Therefore, warpage during cooling of the used materials can be prevented or at least reduced. This results in reduced production rejects, thus lowering manufacturing costs.

In the disclosure a paddle shift lever or paddle shifter or rocker switch refers to an operating element for example in a vehicle. In particular, the lever may be used for gear shifting, as described before. However, that the disclosure is not limited to paddle shift levers. Instead, the disclosure or invention can be used for all switched components or control elements with an overhanging feature such as a paddle shift lever.

The paddle shift lever, especially the base component with the insert part and the shell part, may be manufactured of plastic material, especially thermoplastic material. Suitable materials are, for example, Polycaprolactam (PA6, nylon 6 or nylon 66) or Polyamid 66 (PA66) or other suitable plastic materials for lever manufacturing. Preferably, the base component may comprise an opening for a lightning element of the steering handle. The lightning opening may be positioned in the connection portion of the base component. The lightning element may be mounted behind the opening or pushed through or into the lightning opening. In this way, lighting, such as back lighting of the paddle shift lever can be realized.

The disclosure also comprises embodiments that provide features that provide additional technical advantages.

In one embodiment, the insert part and the shell part are assembled or attached or connected by overmolding. Overmolding is a well-known manufacturing technique, especially for plastic material. With overmolding a previously manufactured injection molded part, the so-called pre-molded part (here for example the insert part), is overmolded or coated with a second melt (here for example the shell part) in a further process step. Overmolding belongs to a type of injection molding process, which is called multi-material-injection molding.

The injection molding process enables high quantities to be produced with consistent quality, thus ensuring high process stability. All process steps can be automated using an injection molding tool, which further reduces costs and ensures reproducibility of component quality. Compared to traditional injection molding, multi-material molding, such as overmolding, can provide even lower costs, a higher quality product, significant reduction in assembly operations, and reduction of cycle times.

In one embodiment for implementing or providing the interlock structure, the insert part comprises a first interlock element and the shell part comprises a corresponding second interlock element. The first interlock element forms a recess to or in a volume body of the insert part. That means that insert part provides a groove nut or opening slit. The second interlock element forms a protrusion to or in a volume body of the shell part. This means the shell part provides a rip or fin.

To form the interlock structure, the first and second interlock elements may be connected in a form fit. Form fit or form closure or positive locking fit is a standard bonding or connection technology in mechanical engineering. The interlock elements are formed correspondingly, that means such that they may be connected in the form fit. For connecting the interlock elements, the protrusion or rip may be pierced or inserted or pushed through the recess, thus the corresponding groove. In the mounted position, the protrusion may be completely pierced or pushed through the recess. Alternatively, the protrusion may be partly inserted in the recess. That means, that the protrusion either overlaps on at least one side of the recess or the protrusion may end or terminate in the volume body of the insert part, thus the recess.

In one embodiment, a recess-to-wall-thickness ratio and/or a protrusion-to-wall-thickness ratio is in the range of 50% to 60%, with regard to a wall thickness of the base component, in particular of the insert part and/or the shell part respectively. That means that the rips may be designed to be 50% to 60% of the nominal wall thickness or material thickness used for the base component or the insert part or shell part. Thinner rip or recess dimensions do not provide much structure and may be hard to manufacture. Thicker rips or recess structures are tempting, but they can begin to introduce sinks on the cosmetic surface.

Here within wall thickness means the material thickness of the base component, in particular in the area of the operating portion. Assembled on a steering handle, the wall thickness is the measured distance or thickness between a front surface or visible surface of the lever and a back surface or touch surface of the lever. The visible surface may be the surface in the operating portion facing the user or driver. The touch surface may be the surface facing away from the user.

In an embodiment, the shell part comprises an upper element and a bottom element, which are attached on opposite sides of the insert part to form a housing. In other words, the shell part comes in a two-part design.

The opposite sides may be the above mentioned visible surface and the touch surface. Hereafter, the visible surface may be referred to as upper side or top side, while the touch surface may be referred to as bottom side or lower side. To form the housing or a cover, the upper element and the bottom element may be attached or connected to each. The upper element and the bottom element may be connected or attached by material closure.

The upper and bottom element may be formed using a multi-shot injection molding process, in particular a two-shot overmolding or 2K overmolding process. Multi-shot injection molding is also referred to as sequential injection molding. In multi-shot injection molding multiple layers of material, here for example two layers, relative to the initial mold are created. One layer may be the upper element and another layer may be the bottom element. In a 2K overmolding process, the insert part may be coated with material to form the upper element from the upper side in a first process step. In a second process step the insert part may be rotated or pivoted and the insert part may be coated with material to form the bottom element from the bottom side.

In one embodiment, for providing the second interlock element corresponding to the shell part, the upper element comprises a first attaching member and the lower element comprises a second attaching member. The first and second attaching member are connected by means of an additional interlock structure. In other words, the second interlock element provides a further or additional interlock structure, as it was described before. The additional interlock structure allows a stable and secure connection of the upper element and the bottom element to reduce or prevent warpage.

In one embodiment, the first attaching member forms a protrusion, thus a rip or fin in or to a volume body of the upper element. The second attaching member forms a protrusion, thus a rip or fin in or to the volume body of the bottom element. In addition, the protrusion of the first attaching member forms a recess for inserting or housing the second attaching member, in particular the protrusion of the second attaching member. Both the first and the second attaching member are at least partially inserted or slotted in the recess formed by the first interlock element of the insert part. In other words, by means of their protrusions, the upper element and the lower element can be attached to each other through the recess (first interlock element) of the insert part. In this way, the paddle shift lever can be further stabilized to enhance the warpage prevention.

Thus, the second interlock element is two-parted. The two parts are the first and second attaching member. For connecting the insert part and the shell part in the respective interlock structure, the first attaching member may be fully inserted or pushed through the recess of the insert part. That means the first attaching member may overlap or protrude the insert part at least on one side. The second attaching member is preferably only partly inserted into the recess. That means the second attaching member may end in the volume body of the insert part.

In one embodiment, for defining or regulating an insertion depth of the second attaching member in the recess formed by the first interlock element of the insert part, the recess comprises an abutting edge for the protrusion of the first attaching member. That abutting edge can be a bumper or stop to prevent a further insertion of the second attaching member. Thus, the abutting edge provides a contact surface in a direction of an insertion direction of the first attaching member. In one embodiment, the respective interlock structure comprises or provides an undercut. In other words, the interlock elements may comprise a form or shape featuring an undercut. The undercut may be provided by an indentation or recess in the material (here, for example, the first and second interlock element and the first or second attaching member, respectively) with a shape, which prevents the work pieces (here the insert part and the shell part) from being separated in a defined direction. Therefore, the degree of freedom of the shell part and the insert part is reduced. In this way, warpage can be prevented successfully.

In one embodiment, the respective interlock structure, in particular the respective interlock elements and/or the respective attaching members progress or extend in the direction of the operating portion starting from the connection portion. That means the respective interlock structures extend in a longitudinal direction of the paddle shift lever.

In one embodiment, the operating portion is at most 10%, preferably at most 5% longer than the connection portion. In this way, the overhang of the operating portion can be reduced, and warpage effects can be further diminished. Preferably, the operating portion and the connection portion provide the same length. Here within length means a distance from one end to another end of a surface with which provides the operating portion or connection portion respectively in the direction of the afore-mentioned longitudinal direction of the lever.

In one embodiment, the insert part and the shell part are formed of plastic materials with different material properties, in particular of thermoplastic materials, with regard to surface finishing and/or material strength. Therefore, the two parts can be adapted to their respective purpose. Preferably, the upper element and the bottom element are also formed of plastic materials with different material properties with regard to surface finishing and/or material strength. For example, the insert part can be formed of a low cost plastic material with higher material strength. Here within material strengths means, for example, hardness, stiffness and/or tensile strength. This results in strong skeleton for the paddle shift lever. In comparison, the shell part may be formed of a material with a particular surface finishing, such as a glossy or textured finish. For example, the upper element facing the driver in the mounted position may come with a glossy finish to enhance optics. In comparison, the bottom element may be formed with a textured finish to enhance the grip for operating the lever. According to another aspect, the disclosure or invention proposes a steering handle for a vehicle, in particular a motor vehicle comprising a paddle shift lever as described before. In a mounting position of the lever, the operating portion of the lever protrudes or overlaps at least partially a grip area of the steering handle. Therefore, the lever, in particular the operating portion of the lever, is visible for a user, e.g. a driver. Considering a steering wheel as a steering handle, the grip area may be rim of the steering wheel. Here within a grip area means the surface or portion of a steering handle, which a user grips or touches when operating the vehicle. The motor vehicle is preferably a passenger car or passenger bus, in particular a truck or motor bike.

According to a further aspect, the disclosure or invention proposes a method for manufacturing a paddle shift lever as described before. In particular, the disclosed method describes an overmolding process for manufacturing a paddle shift lever as described before. The method may be carried out by a molding tool. That means that the respective molding tool can be programmed or implemented to carry out the described method. The method comprises the following steps: providing an insert part and overmolding the insert part with a shell part in a molding tool. By doing so, a base component is formed with an operating portion for operating the lever and a connection portion for connecting the lever to a steering handle. Hereby, the insert part comprises a connecting element in the area of the connection portion, and a protrusion element forming a protrusion relative to the connecting element in the area of the operating portion. The shell part is covering the insert part at least in the area of the operating portion, wherein the insert part and the shell part are being connected by means of an interlock structure in the area of the operating portion.

Thus, the described method can be used to manufacture a paddle shift lever as described before. When carrying out the method, the lever is manufactured. Carrying out the method, the connecting element of the insert part may be a mold contact surface in the molding tool. That means that the insert part may be held or fixed by the connecting element in the molding to perform overmolding. The molding tool may be a conventional overmolding machine. The insert part may be manufactured by injection molding in a previous step or in a separate molding process.

In one embodiment of the method, the insert part is overmolded with the shell part in a two-shot-overmolding process. In a first shot the insert part is overmolded with an upper element of the shell part on a first side (upper side), and in a second shot the insert part is overmolded with a bottom element of the shell part on a second side (bottom side). The upper and the lower element form a housing for the insert part, wherein the first and second side are opposite sides of the insert part. In other words, the paddle shift lever is manufactured by a 2K or two step overmolding process.

For use cases or use situations which may arise in the method and which are not explicitly described here, it may be provided that, in accordance with the method, an error message and/or a prompt for user feedback is output and/or a default setting and/or a predetermined initial state is set

Further implementations of the steering handle and/or the method according to the invention follow directly from the various embodiments of the paddle shift lever according to the invention and vice versa. In particular, individual features and corresponding explanations as well as advantages relating to the various implementations of the paddle shift lever according to the invention can be transferred analogously to corresponding implementations of the steering handle and/or the method according to the invention.

Further features of the invention are apparent from the claims, the figures and the figure description. The features and combinations of features mentioned above in the description as well as the features and combinations of features mentioned below in the description of figures and/or shown in the figures may be comprised by the invention not only in the respective combination stated, but also in other combinations. In particular, embodiments and combinations of features, which do not have all the features of an originally formulated claim, may also be comprised by the invention. Moreover, embodiments and combinations of features which go beyond or deviate from the combinations of features set forth in the recitations of the claims may be comprised by the invention.

In the following, the invention will be explained in detail with reference to specific exemplary implementations and respective schematic drawings or figures. In the drawings, identical or functionally identical elements may be denoted by the same reference signs. The description of identical or functionally identical elements is not necessarily repeated with respect to different figures.

The figures show:

Fig. 1 a schematic illustration of a paddle shift lever according to a preferred embodiment; Fig. 2 a schematic illustration of the paddle shift lever in an exploded view drawing;

Fig. 3 a schematic illustration for different examples of an interlock structure for the paddle shift lever; and

Fig. 4 an exemplary flow chart for a method for manufacturing a paddle shift lever according to a preferred embodiment.

Fig. 1 shows a schematic illustration of a paddle shift lever 1 , in the following abbreviated with lever 1 . The lever 1 may be mounted on a steering handle, for example a steering wheel of a motor vehicle. In this configuration, the lever 1 may be used for gear shifting, in particular manual gear shifting for an automated transmission. For manual gear shifting conventional vehicles typically use two respective levers 1 . They are usually mounted on the left and on the right of the steering handle, in particular behind the steering handle. Here behind means a side of the steering handle, which is facing away from a driver. For operating the respective lever 1 , the driver can, for example, pull the respective lever. Pulling one of the levers downshifts the gear, while pulling the other lever upshifts the gear.

As shown in Fig. 1 , the paddle shift lever 1 comprises a base component 2 with a connecting portion 3b and an operating portion 3a. The operating portion 3a is an area or surface of the lever 1 , which the user uses or touches for operating the lever 1 . The connecting portion 3b is the area or surface of the lever 1 for connecting the lever 1 to the steering handle. In the mounting position, the operating portion 3a of the lever 1 may at least partially protrude or overlap a grip area, such as a rim of the steering handle. Therefore, the operating portion 3a may be an area of the lever 1 , which is visible for the user. In the exemplary embodiment of Fig. 1 , the base component 2 provides an L-shape form or body. However, different other forms or body types are possible as well.

As can be seen in the embodiments in Fig. 1 , the lever 1 may provide a lighting opening 6 for a lighting element of the steering handle or the vehicle. The lighting opening 6 can be used for back lighting or lighting of the lever 1 .

In the mounting position, the lever 1 provides two opposing or opposite sides, one facing the driver and the other facing away from the driver. The side facing away from the driver is called upper side T of the lever 1 . The opposing side, thus the side facing the driver, is called bottom side B. The upper side T may be the side or surface which the driver touches for pulling the lever 1 . The bottom side B may be a side or surface for engraving symbols which symbolize the function executed when operating the lever 1 .

As can be seen in the explosive drawing of the lever 1 according to Fig. 2, the base component 2 comprises an insert or inlay part 4 and a shell part 5. The insert part 4 comprises a connecting element 4a. The connecting element 4a may be a physical connection for connecting the lever 1 to the steering handle. The connecting element 4a is located or positioned in the area of the connecting portion 3b. The insert part 4 further comprises a protrusion element 4b forming a protrusion or overhanging feature relative to the connecting element 4a in the area of the operating portion 3a. The protrusion element 4b is located in the operating portion 3a.

The shell part 5 provides a shell or housing or cover for the insert part 4. That means that the shell part 5 covers the insert part 4 at least in the area of the operating portion 3a. Fig. 1 and Fig. 2 show an embodiment of the lever 1 , where the shell part 5 covers the insert part 4 in the area of the operating portion 3a as well as in the area of the connecting portion 3b. Hereby, the shell part 5 comprises a connecting opening 7 to bring the connecting element 4a out of the housing to the exterior.

The base component 2 is preferably made out of a thermoplastic material, such as PA6 or PA66. The base component 2 may be manufactured by injection molding, in particular mulit-material injection molding. In general, (multi-material) injection molding is a well- known standard method for manufacturing plastic parts or pieces. Hereby, the respective part is produced by injecting molded material into or onto a predefined mold. Preferably the insert part 4 and the shell part 5 are assembled or attached or manufactured by overmolding. Overmolding is a type of multi-material injection molding, where a previously manufactured injection molded part, the so-called pre-molded part, here the, for example, insert part 4, is overmolded or coated with a second melt, here, for example, the shell part 5 in a further process step. Preferably, the overmolding may result in a material connection of the insert part 4 and the shell part 5.

Since injection molding uses molded or viscous material which cools down to its final state, an effect that can occur in the manufactured part is so-called warpage. That means the resulting work piece is distorted, thus differs from a previously desired or intended form. The paddle shift lever 1 , in particular the operating portion, may be susceptible to warpage. To stabilize the base component 2 and to prevent warpage, in particular during cooling, the insert part 4 and the shell part 5 are connected by means of an interlock structure 10 in the area of the operating portion 3a. In the embodiment according to Fig. 2, the interlock structure is implemented by a first interlock element 1 1 of the insert part 4 and a second interlock element 12 of the shell part 5. The first interlock element 1 1 forms a recess or groove into a volume body of the insert part 4. The second interlock element 12 forms a protrusion or a rip from the volume body of the shell part 5. In the assembled or mounted position of the base component 2, the protrusion may be pushed through the recess or inserted in the recess to form the interlock structure 10.

Fig. 1 shows an exemplary embodiment with two interlock elements in total. However, an interlock structure with multiple interlock elements, in particular more than two interlock elements, such as two or more first interlock elements and two or more respective second interlock elements may be possible as well.

A further measure to prevent warpage may be to provide the operating portion 3a and the connecting portion 3b with the same length, as shown in Fig .1 . This ensures that a lever arm, provided by the operating portion 3a, is kept as small as possible to achieve an optimal touching surface for the driver on the one hand and to avoid warpage as much as possible on the other hand.

In the embodiment according to Fig. 2, the shell part 5 comprises two elements or two parts: an upper element 5a and a bottom element 5b. The upper element 5a and the bottom element 5b are attached on opposite sides of the insert part 4 to form the housing. Here within the upper element 5a may be attached to the upper side T, thus providing a surface of the upper side T for the base component 2. The bottom element 5b may be attached on the bottom side B, thus forming a surface for the bottom side B of the base component 2. The upper and bottom element 5a, 5b may be attached to the insert part 4 in a two-step overmolding process. Two-step or 2K-overmolding is well-known injection molding technique, where the insert part 4 may be first coated with one element, for example, the upper element 5a, and then being turned and coated with the other element, for example the bottom element 5b.

Preferably, the upper and bottom element 5a, 5b are connected in a material connection. That means, the materials of the upper and bottom element 5a, 5b are merged or molded together at a respective contact surface. Analog to the shell part 5, the second interlock element 12 is provided in a two-part form as well. Therefore, the upper element 5a comprises a first attaching member 12a, and the bottom element 5b comprises a second attaching member 12b. The first and second attaching members 12a, 12b are connected by means of a additional interlock structure 10’ well as.

To provide the additional interlock structure 10’, the first attaching member 12a forms a protrusion or a rip from a volume body of the upper element 5a. The second attaching member 12b forms a protrusion or a rip from the volume body of the bottom element 5b. In addition, the protrusion of the first attaching member 12a forms or provides a recess for inserting or housing the second attaching member 12b. As depicted in Fig. 2, the recess may be a slit or groove. To interlock or connect the insert part 4 and the shell part 5, both, the first and the second attaching member 12a, 12b are at least partially inserted or slotted in the recess formed by the first interlock element 11 of the insert part 4.

In a preferred embodiment, as depicted in Fig. 2, the second attaching member 12b may be fully inserted or pushed through the recess (first interlock element 11) of the insert part 4. That means that the second attaching member 12b may overlap or protrude the insert part 4 at least on one side, here the upper side T. The first attaching member 12a may only partly be inserted in the recess (first interlock element 11) of the insert part 4. That means, that the first attaching member 12a ends in the volume body of the insert part 4. To regulate the insertion depth of the first attaching member 12a, the recess formed by the first interlock element 11 of the insert part 4 comprises an abutting edge 11a. The abutting edge 11a may provide a bumper or contact surface for the protrusion of the second attaching member 12b. That means that in the assembled position, the first attaching member 12a may contact the abutting edge 11a.

As shown in Fig. 2, the first and second interlock elements 11 , 12, in particular the first and second attaching members 12a, 12b are designed as rips or grooves, which extend in a direction of the operating portion 3a, starting from the connecting portion 3b. That means that the respective interlock structure 10, 10’ extends in longitudinal direction of the lever 1 .

Preferably, the insert part 4 and the shell part 5, in particular the upper element 5a and the bottom element 5b may be formed of different plastic materials with different material properties with regard to surface finishing or material strength. The upper element 5a, which may be the touching surface for the driver, may provide a textured finish to enhance the grip for operating the lever 1 . In comparison, the lower element 5b may provide a glossy surface finish to enhance the optics of the lever 1 .

To provide a secure hold between the interlock elements and/or attaching members, the respective interlock structure 10, 10’ is realized as a so-called undercut 13. An undercut is provided by a protruding construction element in the material, which prevents the workpieces, here the insert and the shell part 4, 5 from being separated in a defined direction. Fig. 3 shows different examples or embodiment of an undercut 13 for the respective interlock structure 10, 10’. However, other shapes or forms of an undercut 13 may be possible as well.

In a first example, the interlock structure 10, 10’ may be provided by an undercut 13 with a socket structure or socket form 10a. To realize the socket for 10a the protrusion (e.g. second interlock element 12) and the recess (e.g. first interlock element 11) provide a conical or cone section arising from a tapered section.

In a second example or embodiment, the interlock structure 10, 10’ is provided by an undercut 13 based on a dovetail joint structure 10b. That means the undercut 13 is realized in the manner of a dovetail joint. In this example, the workpieces, thus the insert part 4 and the shell part 5, are connected by more than one interlock structure, in particular two interlock structures. That means, in contrast to the embodiments shown in Fig. 1 and Fig. 2, the lever 1 may comprise one or more, in particular two or more, interlock structures 10, 10’ for connecting the insert part 4 and the shell part 5.

In another example or embodiment, the respective interlock structure 10, 10’ shows an undercut 13 with an overlapping dovetail joint structure 10c. That means, that the protrusion, here, for example, the second interlock element 12, overlaps the recess or volume body, here, for example, the first interlock element 11 of the insert part 4.

A fourth example or embodiment shows the respective interlock structure 10, 10’ with an undercut 13 with a plate shape structure. That means, that the protrusion, here, for example, the second interlock element 12, provides a tapering or narrowing which expands or faints out into a plate shape. The plate shaped structure 10d therefore provides a T-shape or T-form.

When providing the respective interlock structure 10, 10’ a recess to wall thickness ratio and/or a protrusion to wall thickness ratio preferably is in the range of 50% to 60%, with regard to a wall thickness of the base component 2. That means that the rips or respective grooves should be designed to be 50% to 60% of nominal wall thickness of the base component 2. This results in an optimal filling or material filling, with overmolding and an optimal stability against warpage for the base component 2.

Fig. 4 shows a flow chart for an exemplary embodiment of a method for manufacturing the paddle shift lever 1 . In a step S1 of the method, the insert part 4 is provided. The insert part 4 may be provided by clamping or fixing the insert part 4 with the connecting element 4a on a mold contact surface of a molding tool. Thus, the connecting element 4a may be used as mold contact surface in the molding tool. The molding tool may be a conventional overmolding machine. The insert part 4 may be manufactured in a previous process step before step S1 , for example, by injection molding. Hereby, the plastic material for the insert part 4 may be injected in a corresponding mold. The processing of the insert part 4 may be realized in another molding tool, such as a conventional injection molding machine.

After providing the insert part 4, the method continues with a step S2. In the step S2, the insert part 4 is overmolded with the shell part 5 in the molding tool. If the shell part 5 is provided in the two-part form (see Fig. 2), the overmolding process may be realized in a two-shot or two-part form. That means the insert part 4 is overmolded with the shell part 5 in a two-shot overmolding process. In a first shot, the insert part 4 is overmolded with the upper element 5a of the shell part 5 on a first side, here, for example, the upper side T. In a second shot, the insert part 4 is overmolded with the bottom element 5b of the shell part 5 on a second side, here the bottom side B. As described before, the upper and bottom element 5a, 5b are applied such that they form the housing for the insert part 4.

Overall, the figures show preferred embodiments for mechanical interlocks to optimize the warpage of an overmolded component, here a paddle shift lever 1 . By using the described interlock structure 10, 10’, the reduction in the warpage can be validated through rheology simulation, for example using the software tool Mold Flow®.

Claims

1 . Paddle shift lever (1 ) for a steering handle comprising:

- a base component (2) with an operating portion (3a) for operating the lever (1) and a connection portion (3b) for connecting the lever (1) to the steering handle, wherein

- the base component (2) comprising an insert part (4) and a shell part (5), wherein

- the insert part (4) comprising a connecting element (4a) in the area of the connection portion (3a), and a protrusion element (4b) forming a protrusion relative to the connecting element (4a) in the area of the operating portion (3a), and

- the shell part (5) covering the insert part (4) at least in the area of the operating portion (3a), wherein

- the insert part (4) and the shell part (5) being connected by means of an interlock structure (10, 10’) in the area of the operating portion (3a).

2. Paddle shift lever (1 ) according to claim 1 , wherein the insert part (4) and the shell part (5) are assembled by overmolding.

3. Paddle shift lever (1 ) according to any of the preceding claims, wherein for implementing the interlock structure (10, 10’) the insert part (4) comprising a first interlock element (11) and the shell part (5) comprising a corresponding second interlock element (12), with the first interlock element (11 ) forming a recess in a volume body of the insert part (4) and the second interlock element (12) forming a protrusion in a volume body of the shell part (5).

4. Paddle shift lever (1 ) according to claim 3, wherein a recess-to-wall-thickness ratio and/or a protrusion-to-wall-thickness ratio is in the range of 50% to 60%, with regard to a wall thickness of the base component (2), in particular of the insert part (4) and/or the shell part (5) respectively.

5. Paddle shift lever (1 ) according to any of the preceding claims, wherein the shell part (5) comprises an upper element (5a) and a bottom element (5b), which are attached on opposite sides of the insert part (4) to form a housing.

6. Paddle shift lever (1 ) according to claims 3 and 5 and/or in combination with any of the preceding claims, wherein for providing the second interlock element (12) the upper element (5a) comprising a first attaching member (12a) and the lower element (5b) comprising a second attaching member (12b), with the first and second attaching member (12a, 12b) being connected by means of an additional interlock structure (10’).

7. Paddle shift lever (1 ) according to claim 6, wherein the first attaching member forming (12a) a protrusion in a volume body of the upper element (5a), and the second attaching member (12b) forming a protrusion in a volume body of the lower element (5b), wherein the protrusion of the first attaching member (12a) forming a recess for inserting the second attaching member (12b), wherein both the first and the second attaching (12a, 12b) member are at least partially inserted in the recess formed by the first interlock element (11 ).

8. Paddle shift lever (1 ) according to claims 6 or 7, wherein for defining an insertion depth of the first attaching member (12a) in the recess formed by the first interlock element (11 ), the recess comprising an abutting edge (11 a) for the protrusion of the second attaching member (12b).

9. Paddle shift lever (1 ) according to any of the preceding claims, wherein the respective interlock structure (10, 10’) provides an undercut (13).

10. Paddle shift lever (1 ) according to any of the preceding claims, wherein the respective interlock structure (10, 10’) progresses in the direction of the operating portion (3b) starting from the connection portion (3b).

11 . Paddle shift lever (1 ) according to any of the preceding claims, wherein the operating portion (3a) is at most 10%, preferably at most 5% longer than the connection portion (3b).

12. Paddle shift lever (1 ) according to any of the preceding claims, wherein the insert part (4) and the shell part (5) are formed of plastic materials with different material properties with regard to surface finishing and/or material strength.

13. Steering handle for a vehicle comprising a paddle shift lever (1 ) according to any of the preceding claims, wherein in a mounting position the operating portion (3a) of the lever (1) at least partially protruding a grip area of the steering handle.

14. Method for manufacturing a paddle shift lever (1), comprising the following steps:

- providing an insert part (4),

- overmolding the insert part (4) with a shell part (5) in a molding tool, wherein a base component (2) is formed with an operating portion (3a) for operating the lever and a connection portion (3b) for connecting the lever to a steering handle, wherein the insert part (4) comprising a connecting element (4a) in the area of the connection portion (3b), and a protrusion element (4b) forming a protrusion relative to the connecting element (4a) in the area of the operating portion (3a), and the shell part (5) covering the insert part (4) at least in the area of the operating portion (3a), wherein the insert part (4) and the shell part (5) being connected by means of an interlock structure (10, 10’) in the area of the operating portion (3a).

15. Method according to claim 14, wherein the insert part(4) is overmolded with the shell part (5) in a two-shot-overmolding process, wherein in a first shot the insert part (4) is overmolded with an upper element (5a) of the shell part (5) on a first side and in a second shot the insert part (4) is overmolded with an lower element (5b) of the shell part (5) on a second side, with the upper and the lower element (5a, 5b) forming a housing for the insert part (4), and wherein the first and second side are opposite sides of the insert part (4).