Method for producing a brake caliper of a disc brake
Patent Information
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- ZF CV SYST EURO BV
- Filing Date
- 2024-05-31
- Publication Date
- 2026-04-29
AI Technical Summary
The existing methods for manufacturing disc brake calipers using dip-coating are cost-inefficient due to the need for additional masking agents to prevent paint from entering blind holes, which leads to increased torque requirements and potential screw jamming during automated assembly.
Aligning the brake caliper base body in the dipping tank such that the open end is closer to the bottom of the blind holes allows air to act as a masking agent, reducing paint penetration, and using screws with cutting elements to scrape off paint residues, thereby minimizing torque and jamming issues.
This method reduces production costs by eliminating the need for additional masking agents and minimizes torque requirements during screwing, ensuring complete screw insertion and improved assembly efficiency.
Smart Images
Figure EP2024064988_26122024_PF_FP_ABST
Abstract
Description
[0001] Method for producing a brake caliper of a disc brake
[0002] The invention relates to a method for producing a brake caliper of a disc brake, in particular a commercial vehicle disc brake, wherein the brake caliper is designed to be provided with a cover.
[0003] For disc brake calipers, these are often dip-coated to protect against corrosion. Painting is a contract manufacturing process that is highly cost-sensitive. In addition to the high volumes required for economically viable operation, reducing the amount of preparatory and follow-up work beyond the actual painting process is important.
[0004] The brake calipers have blind holes for attaching the cover. Paint should be avoided if possible, as the paint would hinder the cover's installation and would have to be removed after painting. Previously, the blind holes were often sealed with masking agents, particularly silicone or other plugs, before the painting process to prevent the dip-painting fluid from penetrating the blind holes. However, the use of these masking agents results in additional costs during brake caliper production.
[0005] Paint deposits within blind holes are particularly detrimental when the blind holes have an internal thread, and when the covers are to be screwed onto the brake calipers after the painting process in a (semi-)automated process. It has been observed that paint deposits lead to an increase in the required tightening torque. This may prevent screws from being fully screwed into the blind holes.
[0006] The object of the present invention was to mitigate the disadvantages described above as far as possible in a method of the type described at the outset.
[0007] The present invention solves the problem in a first aspect in that the method comprises the following steps: providing or producing a base body which has a number of blind holes with a base and an opposite unsealed opening for fastening the cover to the base body, aligning the base body with a dip tank such that the unsealed opening is arranged closer to the dip tank than the base of the blind hole, and immersing the base body thus aligned into the dip tank for applying a dip coating.
[0008] The invention is based on the discovery that, to apply a dip coating, particularly a cathodic dip coating, the part to be painted is immersed in the painting fluid. The base body can be immersed in the dip tank once or several times and / or successively immersed in several dip tanks containing different fluids, e.g., cleaning fluids beforehand, primer, paint, etc. Since the bores in the brake calipers are blind bores, if the base body is aligned with a dip tank such that the unsealed opening is closer to the dip tank than the bottom of the blind bore, the painting fluid may not penetrate into the blind bores, or may only penetrate in small quantities. This is due to the accumulation of air within the blind bores. In other words, according to the invention, air is used as a masking agent.This eliminates the need to use additional costly masking agents.
[0009] Where the term air is used above and below, it should be understood in connection with the invention that it can be replaced by other gases or mixtures of substances that are suitable for dip painting.
[0010] In a preferred embodiment of the method according to the invention, the method further comprises providing or producing a number of screws, each of which has a cutting element, and screwing the screws into the blind bores, the blind bores preferably being threaded bores. The paint residues in the bore saddle are scraped off by the cutting element of the screw. The cutting elements can be designed, for example, as a scraping groove, cutting groove, or thread-forming / thread-forming. Consequently, the cutting elements reduce blockages caused by paint residues within the blind bores during screwing in, or increases in the required torque caused by the paint residues during screwing in.
[0011] In a preferred embodiment of the method according to the invention, only a thread-free section adjacent to the surface into which the blind hole is made and optionally five or fewer threads within the blind holes are coated during dip coating. This reduces the torque required during the subsequent screwing in and reduces the likelihood of a torque increase or even the risk of the screws jamming during the screwing-in process. In a preferred embodiment of the method according to the invention, the blind holes are deeper than the length of the screws by a predetermined length, so that when screwed in, a dead space is formed within the blind hole, each closed by a screw. As a result, material separated by a screw within the blind hole collects in the space below the maximum screw-in depth of the blind hole or the dead space.Consequently, additional process steps in which material accumulated by the screws within the blind hole is removed can be avoided.
[0012] In a preferred embodiment of the method according to the invention, the base body is aligned prior to the screwing-in step such that the opening is farther from the immersion tank than the bottom. This causes separated material to accumulate at the bottom of the blind hole during the screwing-in process and to be trapped in the dead space upon completion of the screwing-in process. There, the material does not interfere, and the production environment is less contaminated.
[0013] In a preferred embodiment of the method according to the invention, a screwing torque and / or a rotation angle acting on the screws is monitored during the screwing-in step. This prevents overtightening during the screwing-in process and allows it to be determined whether the screw has been fully screwed in. This is possible because the amount of paint deposits in the blind bore has been reduced to a tolerable level by prior masking with air.
[0014] In a preferred embodiment of the method according to the invention, the method further comprises applying a solid or liquid threadlocker to the external thread of the screws or to the internal thread of the blind holes before screwing in. This increases the load-bearing capacity of the screw connection.
[0015] In a preferred embodiment of the method according to the invention, the base body is aligned before immersion such that the axes of the blind holes have an angle of 10° or less to the vertical.
[0016] In a preferred embodiment of the method according to the invention, the blind holes and corresponding holes in the cover are aligned with each other, so that when the screws are subsequently screwed in, the cover is screwed to the base body. According to a second aspect, the invention relates to the use of a screw with a cutting element.
[0017] The invention solves the problem described above in that the screw is used for fastening a cover to a base body of a brake caliper of a disc brake, in particular a commercial vehicle disc brake, wherein the screw is screwed into a blind bore, wherein in particular the base body has been coated in a method according to one of the preferred embodiments described above.
[0018] The use according to the invention utilizes the same advantages as the method according to the first aspect. Preferred embodiments of the first aspect are also preferred embodiments of the second aspect, and vice versa; therefore, to avoid repetition, reference is made to the above explanations in this regard.
[0019] The invention is described in more detail below with reference to preferred embodiments in the accompanying figures. Herein:
[0020] Fig. 1 is a schematic representation of an embodiment of the method according to the invention in a block diagram
[0021] Fig. 2 is a schematic representation of a screw during screwing into a blind hole in a first screwing position according to the method according to the invention in a cross-sectional view
[0022] Fig. 3 is a schematic representation of the screw shown in Fig. 1 in a second screwing position according to the method according to the invention in a cross-sectional view
[0023] Fig. 4 is a schematic representation of the screw shown in Fig. 1 in a third screwing position according to the method according to the invention in a cross-sectional view
[0024] Fig. 1 shows an embodiment of a method for producing a painted brake caliper for a commercial vehicle disc brake. First, in step 101, a base body 1 is provided or produced, which has a number of blind holes 3 with a base and an opposite, unsealed opening 5 for attaching a cover 7 to the base body 1. Subsequently, in step 103, the base body 1 is aligned. In sub-step 103a, the base body 1 is first aligned with a dip tank such that the unsealed opening 5 is located closer to the dip tank than the base of the blind hole.
[0025] In step 103b, the base body 1 is also aligned prior to immersion such that the axes 21 of the blind holes 3 are at an angle of 10° or less to the vertical. Step 105 involves immersing the thus aligned base body 1 into the dip tank for applying a dip coating 9.
[0026] Furthermore, in preparation for screwing in, in step 107, a number of screws 11 are provided, wherein the screws 11 each have a cutting element 13.
[0027] In step 109, a liquid threadlocker 15 is applied to the external thread of the screws 11 before screwing in. Alternatively or additionally (not shown), in step 109, liquid threadlocker 15 can also be applied to an internal thread of the blind bore 3.
[0028] In step 111, the base body 1 is optionally aligned to prepare for screwing in. Therefore, step 111 occurs before step 113 of screwing in.
[0029] In sub-step 111a, the alignment is performed such that the opening 5 is further away from the immersion tank than the bottom. In sub-step 111b, the blind holes 3 and the corresponding holes 8 in the cover 7 are aligned with each other so that the cover 7 can be screwed to the base body when the screws 11 are subsequently screwed in.
[0030] In step 113, the screws 11 are then screwed into the blind holes 3, wherein the blind holes 3 are preferably threaded holes, or alternatively, the thread is introduced in the same work step. During step 113, a screwing torque and / or a corresponding angle of rotation acting on the screws is preferably monitored.
[0031] Fig. 2 shows a section of a base body 1 of a brake caliper of a disc brake used in the method according to the invention. In the section, one of the blind bores 3 is shown with an opening 5. The base body has a dip-coated layer 9. To attach a cover 7 to the base body 1, a screw 11 is screwed through the bore 8 of the cover 7 into the blind bore 3. The screw 11 has a cutting element 13 and is coated with a threadlocker 15, whereby it should be understood that additionally or alternatively, the threadlocker 15 can also be applied to the internal thread of the blind hole 3. Part of the blind bore 3 is provided with dip-coating residues 17. The blind bore 3 has an axis 21 which is aligned at an angle to the vertical of, for example, 0°.
[0032] Fig. 2 shows the beginning of the screwing-in process, in which the cutting element 13 of the screw 11 reaches the area of the undesired dip-painting residues 17 within the blind bore 3 and from this point on scrapes off the dip-painting residues 17 as the screwing continues.
[0033] Fig. 3 shows the arrangement shown in Fig. 2, with the screw 11 further screwed in and almost all dip-painting residues 17 removed from the side wall of the blind bore 3 by the cutting element 13. This results in an accumulation and confinement of scraped-off paint residues 19 in the lower area of the blind bore 3.
[0034] In Fig. 4, the screwing process is complete. The screw 11 is fully screwed into the blind bore 3. All dip coating residues 17 have been removed by the cutting element 13 and are located in the lower area of the blind bore 3 in the form of scraped-off paint residues 19. Consequently, the base body 1 is screwed to the cover 7. Here, IB represents the thickness of the coating of the base body plus the thickness of the cover, Is the length of the screw (without head), and IT+IB the height of the dead space.
[0035] Reference symbol (part of the description)
[0036] I Basic body
[0037] 3 blind hole
[0038] 5 Opening the blind hole
[0039] 7 Cover
[0040] 9 Dip coating layer
[0041] II Screw
[0042] 12 Dead space
[0043] 13 Cutting element
[0044] 15 Screw locking
[0045] 17 Dip coating layer / dip coating residues in a blind hole
[0046] 19 Scraped paint residues
[0047] 21 Axis of a blind hole
[0048] 101 , 103, 103a, 103b, 105, 107, 109, 111 , 111 a, 111 b, 113 Process steps
[0049] Is screw length (without head)
[0050] IB Thickness of the coating of the base body plus thickness of the cover
[0051] IT+IB height of dead space
Claims
Patent claims 1. A method for producing a brake calliper of a disc brake, in particular a commercial vehicle disc brake, wherein the brake calliper is designed to be provided with a cover (7), the method comprising the steps of: - Providing or producing a base body (1) having a number of blind holes (3) with a base and an opposite unsealed opening (5) for fastening the cover (7) to the base body (1), - Aligning the base body (1) to a dip tank such that the unsealed opening (5) is located closer to the dip tank than the bottom of the blind hole, and - Immersing the thus aligned base body (1) into the dipping tank for applying a dip coating (9).
2. Method according to claim 1, wherein the blind bore (3) has an internal thread (4), and the method comprises the steps: - Providing a number of screws (11), wherein the screws (11) each have a cutting element (13), and - Screwing the screws (11) into the blind holes (3), whereby the blind holes (3) are preferably threaded holes.
3. Method according to claim 2, wherein the blind bores (3) are deeper by a predetermined length (IT) than the length of the screws (Is), so that in the screwed-in state a dead space (12) is formed which is closed by a screw (11) within the blind bore (3).
4. The method according to claim 3, comprising the step: Before screwing in, align the base body (1) so that the opening (5) is further away from the immersion tank than the bottom.
5. Method according to one of claims 2 to 4, comprising the step of: monitoring a screwing torque and / or angle of rotation acting on the screws during the screwing-in step.
6. Method according to one of claims 2 to 5, further comprising applying a solid or liquid threadlocker (15) to the external thread of the screws (11) or to the internal thread of the blind bores (3) before screwing in.
7. Method according to one of the preceding claims, wherein the base body (1) is aligned before immersion such that axes (21) of the blind bores (3) have an angle of 10° or less to the vertical.
8. Method according to one of claims 2 to 7, comprising aligning the blind bores (3) and corresponding bores (8) in the cover (7) in alignment with one another, so that when the screws (11) are subsequently screwed in, the cover (7) is screwed to the base body.
9. Use of a screw with a cutting element for fastening a cover to a base body of a brake caliper of a disc brake, in particular a commercial vehicle disc brake, wherein the screw is screwed into a blind bore, wherein in particular the screw is adapted for use in a method according to one of the preceding claims.