Method for manufacturing a chassis

Abstract

Method for manufacturing a chassis, in particular for single-track vehicles, wherein the chassis comprises at least a frame and a fork, comprising the steps: - Inserting a head tube (12) into a head head (20) of the frame and - Creating a rotationally fixed connection between a fork bridge (11) and the head tube (12), wherein the head tube (12) is inserted section by section into an opening (15) of the fork bridge (11), characterized by the step: - Adjustment of a steering head bearing (21) arranged between the steering tube (12) and the steering head (20), wherein the adjustment of the steering head bearing (21) is carried out between the steps of inserting the steering tube (12) into the steering head (20) and creating the connection between the fork bridge (11) and the steering tube (12).

Description

[0001] The invention relates to a method for manufacturing a chassis, in particular for single-track vehicles such as motorcycles, scooters, bicycles and the like.

[0002] Single-track vehicles are known in the prior art, for example, as motorcycles. These have a chassis, which simultaneously forms the load-bearing basic structure. The chassis comprises a frame, also called the main frame, to which the essential components such as the rear swingarm, engine, fuel tank, seat, etc., are attached. A non-steerable rear wheel is connected to the main frame via a rear swingarm. To enable cornering, the front wheel is steerable. The front wheel is guided by a front wheel guidance device, generally referred to as a "fork." The fork is rotatably connected to the frame about a steering axis.

[0003] Typically, the forks are designed as telescopic forks, with two fork legs connected by one or more triple clamps. The head tube is pressed into this triple clamp and is then rotatably mounted in the motorcycle frame. Each fork leg of the telescopic fork is clamped in a slotted bore of the triple clamp. This pre-assembled unit of triple clamps and fork legs is attached to the frame, into which the head tube is inserted into a headset on the frame. Following this, the headset bearing, which allows the head tube to rotate within the headset, is adjusted.

[0004] Threading the head tube, with the other suspension fork components attached to it, into the head tube proves difficult and increases assembly time. Furthermore, adjusting the head tube bearings is also more complicated.

[0005] The patent application DE 199 49 621 A1 relates to a fork bridge for motorcycles with an upper fork bridge section and a lower fork bridge section, which essentially have a corresponding basic shape, are arranged parallel to each other and on which a steering axis running essentially perpendicular to the upper fork bridge section and the lower fork bridge section can be attached approximately in the middle, wherein the upper fork bridge section and the lower fork bridge section are integrally formed with each other via two connecting elements spaced apart from the steering axis and arranged approximately parallel to the steering axis.

[0006] Further front forks for motorcycles are known from JP H08-127 379 A, ​​US 5 487 553 A and CH 703 645 A2.

[0007] Based on this prior art, the present invention aims to provide a method for manufacturing a chassis for single-track vehicles, overcoming the disadvantages of the prior art. A particular objective is to provide a method that reduces assembly effort.

[0008] This problem is solved by a method having the features of independent claim 1. The dependent claims represent advantageous embodiments of the invention.

[0009] To solve this problem, the invention proposes a method for manufacturing a chassis, particularly for single-track vehicles, wherein the chassis comprises at least a frame and a fork. Single-track vehicles within the meaning of the invention are, in particular, motorcycles, scooters, bicycles, mopeds, pedelecs, and the like. However, the invention is also applicable to multi-track vehicles, such as trikes, snowmobiles, or similar vehicles. The method can include at least the steps of inserting a head tube into a head tube of the frame and creating a rotationally fixed connection between a fork bridge and the head tube, wherein the head tube is inserted at least partially into an opening of the fork bridge. Advantageously, the fork bridge is connected to the head tube before other components of the fork are connected to the fork bridge. This makes it particularly easy to thread the head tube into the head tube of the frame.

[0010] Furthermore, the fork crown and the head tube can be connected via a screw connection. The screw connection offers the advantage that a predetermined force can be precisely controlled when connecting the fork crown to the head tube, allowing the head tube to be easily inserted into the fork crown opening and secured without the risk of misalignment.

[0011] Furthermore, or alternatively, an interference fit, a transition fit, and / or an interference fit can be created between an outer surface of the head tube and an inner surface of the fork crown opening. This advantageously increases the surface pressure and creates a rotationally rigid connection between the fork crown and the head tube.

[0012] According to a further embodiment of the method, after creating a rotationally fixed connection between the fork crown and the head tube, the screw connection can be loosened. By appropriately dimensioning the pressure between the outer surface of the head tube and the inner surface of the fork crown opening, such a strong rotationally fixed connection can be achieved that the connecting screw can be removed. The fork crown then remains rotationally fixed and also axially displaceable to the head tube. According to this embodiment, the screw connection is not intended to be permanent but serves as an assembly aid.

[0013] In an alternative embodiment of the method, the fork bridge can be multi-part and include at least one clamping jaw, wherein, when the connection between the head tube and the fork bridge is created, the head tube is attached to the fork bridge by means of the clamping jaw. The clamping jaw can also be designed as a clamp, wherein it is screwed to the fork bridge by means of screws.

[0014] Furthermore, in a further process step, a steering head bearing located between the head tube and the head tube is adjusted. This steering head bearing allows the fork to rotate relative to the frame, thus enabling steering movements.

[0015] Preferably, the head tube is first inserted into the frame's head tube, and then the connection between the triple clamp and the head tube is made. This offers the advantage of ensuring particularly good and precise adjustment of the steering head bearings. Firstly, the head tube can be rotated completely without the triple clamp or other fork components contacting the frame. Secondly, the weight of the entire fork does not act on the head tube during steering head bearing adjustment. Finally, this method allows the use of tapered roller bearings, which significantly improves the steering head bearing's performance.

[0016] Furthermore, the adjustment of the steering head bearing takes place between the steps "inserting the head tube into the head tube" and "creating the connection between the fork bridge and the head tube".

[0017] Furthermore, at least one shock absorber can be mounted on the fork bridge.

[0018] To connect the shock absorber, it can be clamped to the triple clamp using a clamping jaw. This offers the advantage that the shock absorber is mounted onto the fully assembled triple clamp, and thus onto a fully adjusted steering head bearing, using a clamp or clamping jaw. This avoids unwanted weight influences that can occur during the adjustment and setting of the steering head bearing.

[0019] The invention is explained in more detail below with reference to the description of the figures. The claims, figures, and description contain a number of features that a person skilled in the art would also consider in other combinations to adapt them to other embodiments of the present invention.

[0020] They show in schematic representation Fig. 1: a section through a fork bridge concept according to a first embodiment before the assembly step, Fig. 2: a sectional view through a fork bridge concept according to the first embodiment after the assembly step, Fig. 3: a partial section through a fork bridge concept according to a second embodiment, Fig. 4: a sectional view from below of the in Fig. 3. Illustrated embodiment of the fork bridge concept, and Fig. 5: a reduced-size representation of the fork bridge concept from Fig. 4.

[0021] In Fig. Figure 1 shows a steering head 20, which is part of a main frame (not shown). This main frame has a through-hole in its axial longitudinal direction L. A steering tube 12 is inserted into this through-hole. To secure and facilitate rotation, a steering head bearing 21 is provided between the steering tube 12 and the steering tube 20. This steering head bearing 21 can be designed as a roller bearing, spherical bearing, tapered roller bearing, needle bearing, or plain bearing. Fig. Below the steering head bearing 21, the steering tube 12 has a circumferential projection that acts as a stop. In the installed state, this projection defines a position in which the steering tube 12 cannot be pushed further into the through-hole of the steering head 20. Below this circumferential projection, the steering tube 12 has a section with an outer surface 12a. This section is designed to engage with an opening 15 in a fork bridge 11 shown below. The opening 15 of the fork bridge 11 has an inner surface 11i. This inner surface 11i can engage with the outer surface 12a of the opening 15.

[0022] A screw 13 is provided for mounting the fork bridge 11 to the steering tube 12. This screw is supported on the fork bridge 15 by a washer 14. During assembly, the screw 13 is screwed into a bore 16 in the steering tube, which has an internal thread. Tightening the screw 13 creates a threaded connection between the fork bridge 11 and the steering tube 12. The steering tube 12 can then be inserted into the opening 15 with slight play. As the screw is tightened, the transition or interference fit described above is created between the outer surface 12A and the inner surface 12I. Fig. Figure 1 shows a state after the head tube has been inserted into the head tube and adjusted, and before the fork bridge has been connected to the head tube. Fig. Figure 2 shows the end of the assembly process, where the fork bridge 11 is mounted on the head tube 12.

[0023] Fig. Figure 3 shows a second embodiment. This differs from the one described in the Fig. 1 and Fig. In the embodiment shown in Figure 2, the head tube 12 does not have a bore 16. This is also unnecessary, since the head tube 12 is not screwed to the fork bridge 11, but clamped. For better clarity, see Figure 2. Fig. 4 is referenced, in which a section view along the section line AA is shown. Fig. Figure 3 shows that the fork bridge 11, according to the second embodiment, is designed in two parts, with a first main part 11.1 and a clamping jaw 11.2. The clamping jaw 11.2 is screwed on by means of screws 17, which engage in blind holes 18 in the main part 11.2. This clamps the head tube 12 between the clamping jaw 11.2 and the main part 11.1. This differs from the illustration in Fig. 4. The blind holes 18 can also be implemented as through holes. For sufficient clamping, the [missing information] bridges the [missing information]. Fig. 4. Screw 17 shown on the right creates a clamping gap.

[0024] Fig. 5 shows the section view from Fig. Figure 4 shows a reduced-size representation. This illustrates how the fork legs 31 are attached to the triple clamp 11. They are clamped with additional clamping jaws 30 or clamps. Each clamping jaw 30 is attached to the triple clamp 11 by two screws 32. Although the assembly of the fork legs 31 is only shown using the second embodiment, this type of fork leg assembly is not limited to this. Of course, the embodiment according to the Fig. 1 and Fig. 2 the fork legs 31 via analogous clamping jaws 30 with the in the Fig. 1 and Fig. 2 the fork bridge 11 shown are connected.

[0025] According to the setup described here, an assembly procedure for a chassis is proposed in which, in a first step, the head tube 12 is threaded into the head tube 20 of the frame. In a second step, a triple clamp 11 is pulled onto the fully assembled head tube 12 and the adjusted steering head bearing 21 using a screw 13 or a clamping jaw 11.2. The adjustment of the steering head bearing 21 is thus possible under optimal conditions. The bearing can complete several full (360°) rotations. In a final step, the fork legs 31 are attached to the triple clamp 11 using clamping jaws 30. This enables, among other things, fork leg assembly in sync with the assembly line of the chassis or vehicle assembly. Furthermore, the pre-assembly of the separate "fork" assembly is eliminated.

Claims

[1] Method for manufacturing a chassis, in particular for single-track vehicles, wherein the chassis comprises at least a frame and a fork, comprising the steps: - Inserting a head tube (12) into a head head (20) of the frame and - Creating a rotationally fixed connection between a fork bridge (11) and the head tube (12), wherein the head tube (12) is inserted section by section into an opening (15) of the fork bridge (11), characterized by the step: - Adjustment of a steering head bearing (21) arranged between the steering tube (12) and the steering head (20), wherein the adjustment of the steering head bearing (21) is carried out between the steps of inserting the steering tube (12) into the steering head (20) and creating the connection between the fork bridge (11) and the steering tube (12). [2] Method according to claim 1, characterized by , that the fork bridge (11) and the head tube (12) are connected via a screw connection. [3] Method according to claim 1 or 2, characterized by , that an interference fit is created between an outer surface (12A) of the steering tube (12) and an inner surface (111) of the opening (15) of the fork bridge (11). [4] Method according to one of claims 2 and 3, characterized by , that after creating the rotationally fixed connection between the fork bridge (11) and the steering tube (12), the screw connection is loosened. [5] Method according to any one of the preceding claims, characterized by , that the fork bridge (11) is designed in multiple parts and comprises at least one clamping jaw (11.2), wherein when creating the connection between the head tube (12) and the fork bridge (11) the head tube (12) is attached to the fork bridge (12) with the clamping jaw (11.2). [6] Method according to claim 1, characterized by, that first the head tube (12) is inserted into the head head (20) of the frame and then the connection between the fork bridge (11) and the head tube (12) is created. [7] Method according to any of the preceding claims, characterized by the step: - Connecting at least one shock absorber (31) to the fork bridge (11). [8] Method according to claim 7, characterized by , that - to connect the shock absorber (31), which is clamped to the fork bridge (11) with a clamping jaw (30).

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