Brake module for a vehicle flap drive system and vehicle flap drive system

Abstract

The invention relates to a brake module (100) for a vehicle flap drive system with at least one first friction partner (130) and at least one second friction partner (160, 170), wherein the friction partners (130, 160, 170) each have at least one friction surface (140, 150, 180, 190) that rubs against each other during braking operation, wherein the first friction partner (130) is formed in one piece from a plastic with a carbon fiber content. Furthermore, the invention relates to a vehicle flap drive system comprising a brake module (100).

Description

[0001] The present invention relates to a brake module for a vehicle flap drive system with at least one first friction partner and at least one second friction partner, wherein the friction partners each have at least one friction surface that rubs against each other during braking operation.

[0002] In drive systems, particularly spindle drives used for vehicle hatches, it is necessary to apply a load torque to optimize the force curve during the extension and retraction of the spindle and to generate a holding force when stationary. This enables both the vehicle hatch to be held in place and the drive system to move smoothly. It also prevents damage caused by excessive forces from the weight of the hatch or excessive manual force from the user. Various braking systems are known in the art. Examples include a disc or coil spring brake with friction surfaces, a switchable energized brake made of electromagnets with friction surfaces, or a non-switchable hysteresis brake made of two permanent magnets.However, the known braking systems have various disadvantages such as noise generation, increased wear, and dependence on temperature and speed.

[0003] A disc or coil spring brake with friction surfaces, for example, is not noise-free or odorless, nor is it independent of temperature and speed. Furthermore, brakes of this design are not wear-resistant and usually contain PTFE.

[0004] Additionally, switchable, energized brakes made of electromagnets with friction partners are not easy to install and require auxiliary power.

[0005] In particular, non-switchable hysteresis brakes made of two permanent magnets, as well as switchable energized brakes made of electromagnets with friction partners, are costly.

[0006] The present invention therefore aims to provide a brake module for a vehicle flap drive system that can overcome the disadvantages of known systems and is also cost-effective. Furthermore, a vehicle flap drive system with a brake module is to be provided.

[0007] The subject matter of the present invention provides a brake module for a drive system that solves this problem according to the invention, as defined in claim 1. The problem is also solved by a drive system according to the features of claim 11. Advantageous embodiments are described in the dependent claims.

[0008] A brake module according to the invention for a vehicle flap drive system comprises at least one first friction partner and at least one second friction partner. The friction partners each have at least one friction surface that rubs against each other during braking. The first friction partner is formed in one piece from a plastic containing carbon fibers.

[0009] The solution according to the invention presents an optimized combination of friction partners, which offers a simple design, is particularly cost-effective and durable at the same time.

[0010] The one-piece plastic construction of the brake module makes it lighter and more cost-effective to manufacture, as complex assembly processes and material connections are avoided. This eliminates the need for an elaborate and expensive coating with one or more friction layers. Furthermore, the initial plastic friction partner is resistant to storage conditions.

[0011] The carbon fiber content in the plastic ensures durable, low-wear friction between the friction partners. At the same time, the coefficient of friction can be increased and excessively high static friction avoided. Thus, the design according to the invention allows for a low variance in the braking torque.

[0012] For the purposes of this invention, the term "vehicle flap" refers to a component for at least partially closing an opening of a vehicle. In particular, the vehicle flap can be a vehicle door, a hood, a trunk lid, a cargo door, or a tailgate. The use of the brake module for a device or structure is also conceivable.

[0013] To provide a compact brake module, preferably the first friction partner is designed as a brake disc and the second friction partner as a thrust disc.

[0014] According to an advantageous embodiment of the invention, a second friction partner can be provided on each of two opposite sides of the first friction partner, the first friction partner having a friction surface facing each of the second friction partners. The use of two second friction partners allows for a longer service life and higher braking force without significantly increasing the dimensions of the brake module.

[0015] At least one second friction partner can be made of steel, in particular, preferably, non-nitrided chromium-5 steel. It has been found that while a second friction partner, for example, in the form of a thrust washer made of non-nitrided chromium-5 steel, has a shorter service life than a thrust washer made of nitrided chromium-5 steel, the vibration and noise generated during friction with a first friction partner, for example, a brake disc made of fiber-reinforced plastic, is significantly reduced compared to nitrided chromium-5 steel. Such a brake module according to the invention with thrust washer(s) made of non-nitrided chromium-5 steel nevertheless has a comparable or even longer service life than a prior art brake module.

[0016] The first friction component can be manufactured particularly easily and cost-effectively using an injection molding process. The carbon fibers can simply be added to the plastic material as offcuts, thus combining the superior mechanical properties of the carbon fibers with the ease of processing the plastic, resulting in a reliable, lightweight, and cost-effective brake module.

[0017] Preferably, the friction surface of the first friction partner has a number of recesses for receiving a lubricant. These recesses allow for further optimization of wear resistance and noise characteristics. The recesses serve as a reservoir for a lubricant specifically formulated for the friction partners, thereby increasing the service life of the brake module without requiring large quantities of lubricant.

[0018] According to a particularly advantageous embodiment of the invention, the lubricant is PFPE-, PTFE- and silicone-free, which ensures an environmentally friendly application without harmful components.

[0019] The first friction partner can be annular and, in particular, have a central recess, the central recess preferably being approximately circular, and especially having at least two tooth sections separated from each other by a number of, for example, one, two, three, four, five, six, or seven, recesses, wherein the tooth sections preferably comprise radially inwardly projecting teeth. Such a design allows for a more flexible connection of the first friction partner, for example, to a drive shaft, in particular a threaded spindle of the drive system. This also makes it easier to install the brake module late in the production process of a drive system and to avoid vibration damage during assembly, or to remove it if the brake module is defective.An approximately circular cross-section of the recess can, for example, mean that the cross-section is circular except for the radially inwardly projecting tooth sections. The recesses are advantageously distributed uniformly around the circumference of the first friction partner, i.e., with a constant angular spacing from each other, to ensure a uniform load on the first friction partner and thus a long service life.

[0020] The brake module can comprise a housing in which the first friction partner and the at least second friction partner are guided, preferably coaxially about a central axis, in particular the longitudinal axis of the drive system, especially a threaded spindle. The brake module preferably includes a cover plate which is connected to the housing, preferably by a snap-fit ​​connection, such that the first friction partner and the at least second friction partner are held in the housing. The cover plate can, for example, have snap-fit ​​recesses into which snap hooks of the housing can engage. Advantageously, the snap-fit ​​connection can be designed such that the cover plate cannot be separated from the housing without damage. This protects components arranged in the housing from tampering.

[0021] Preferably, the brake module is constructed along its longitudinal axis as follows: spring, second friction partner, first friction partner, second friction partner, cover plate. Preferably, all these components are at least partially enclosed by the housing. This allows for easy installation of the brake module in the drive system without the risk of losing any part of the brake module.

[0022] The housing can include a number of slots, the longitudinal axis of which is advantageously aligned parallel to the longitudinal axis of the drive system. Furthermore, at least one second friction partner can have projections extending radially outward from the longitudinal axis, which are shaped complementarily to the housing slots, such that the slots and the projections interact in a positive-locking manner to prevent rotation of the second friction partner relative to the housing about the longitudinal axis. This prevents the second friction partner from rotating with the first during braking, which could reduce or even eliminate the braking effect. By aligning the longitudinal axis of the slots parallel to the longitudinal axis of the drive system, the thrust washer can be easily inserted into the housing along its longitudinal axis during brake module assembly.Advantageously, the housing slots are evenly distributed around the longitudinal axis of the housing, i.e., with a constant angular distance between them. This distributes the load evenly across the housing, which increases its service life.

[0023] The problem according to the invention is also solved by a vehicle flap drive system comprising a brake module according to one of the preceding embodiments.

[0024] Specifying the drive system as an electric spindle drive offers precise controllability and high positioning accuracy, which is particularly important for applications such as moving vehicle flaps. Electric spindle drives are characterized by quiet operation, which increases user comfort and improves acceptance in noise-sensitive environments, such as passenger cars.

[0025] The present invention is described below with reference to an exemplary embodiment. The drawings, the description, and the claims contain numerous features in combination. It is advantageous for those skilled in the art to also consider the features individually and combine them into meaningful further combinations.

[0026] It represents: Fig. 1 a spatial representation of a brake module according to the invention; Fig. 2 an exploded view of the brake module from Fig. 1; Fig. 3 a side view of the brake module Fig. 1; Fig. 4 a cross-section AA of the brake module Fig. 3; Fig. 5 an enlarged spatial representation of a brake disc of the brake module from Fig. 1 and Fig. 6 another cross-section of the brake module Fig. 3 with a drive system driver.

[0027] In Fig. Figure 1 shows a three-dimensional representation of a brake module 100 according to the invention. The brake module 100 is, for example, connected via a Fig. The driver 2 shown in Figure 6 is connected to a spindle (not shown) of a vehicle flap drive system. The drive system can be an electric spindle drive, which is known, for example, from EP 1 767 439 A2. The spindle is driven rotaryally by a drive unit designed as an electric motor, which allows the fastening elements of the spindle drive to be moved relative to each other, for example to open or close a vehicle flap.

[0028] Fig. Figure 2 shows the brake module 100 of the Fig. Figure 1 shows an exploded view. A first friction partner – here a brake disc 130 – comprises at least one, preferably two, friction surfaces 140, 150, each of which rubs against an adjacent friction surface 180, 190 of second friction partners – here two thrust washers 160, 170 – during braking operation as a result of the relative rotation of the brake disc 3 relative to the thrust washers 160, 170 about a longitudinal axis of the spindle or the drive system. This exerts a braking torque on the spindle of the drive system. A spring 200 exerts a spring force along the longitudinal axis on one of the thrust washers 160, thereby pressing the brake disc 130 and the thrust washers 160, 170 together to maintain frictional contact. The strength of the spring force is a parameter by which the magnitude of the braking force can be determined. In this embodiment, the spring 200 is a wave spring.

[0029] The brake disc 130, the thrust washers 160 and 170, the spring 200, and a cover plate 210 are arranged coaxially around the longitudinal axis within a housing 220. The housing 220 is connected to the cover plate 210 by a snap-fit ​​connection, which holds the brake disc 130, the two thrust washers 160 and 170, and the spring 200 within the housing 220. The cover plate 210 has detent recesses 215 that engage in detent hooks 225 of the housing 220. The assembly of the brake module along the longitudinal axis is thus: spring 200, thrust washer 160, brake disc 130, thrust washer 170, cover plate 210. In the assembled state, all these components are at least partially enclosed by the housing 220. This allows for easy installation of the brake module 100 in the drive system without the risk of losing part of the brake module 100.

[0030] The housing 220 further comprises a number of, for example, five, housing slots 226 evenly distributed around the longitudinal axis in the circumferential direction of the housing 220, with a slot longitudinal axis parallel to the longitudinal axis. Radially outward-facing projections 165, 175 of the thrust washers 160, 170 engage in the housing slots 226. This prevents relative rotation of the housing 220 and the thrust washers 160, 170 relative to each other around the longitudinal axis when the brake disc 130 rotates with the spindle and rubs against the thrust washers 160, 170 during braking operation.

[0031] The brake disc 130 is annular and has a central recess 135. The central recess 135 has an approximately circular cross-section with at least two, for example four, toothed sections 136 evenly distributed around the longitudinal axis of the brake disc 130 in the circumferential direction and separated from each other by cutouts 137. The design of the brake disc 130 is determined in particular by Fig. Figure 5 shows an enlarged view of the brake disc 130. The tooth sections 136 comprise radially inwardly projecting teeth 138. This design allows for a flexible connection of the brake disc 130 via the Fig. Figure 6 shows the driver 120 with the spindle of the drive system. The driver 150 comprises wings 125 that engage in the recesses 137 of the brake disc 130. The transmission of torque between the driver 120 and the brake disc 130 takes place via the contact between the wings 125 and the teeth 138.

[0032] How in particular Fig. As can be seen from Figure 5, the friction surfaces 140, 150 of the brake disc 130 have a number of recesses 139 for receiving a lubricant, which are designed as overlapping circular segments opening radially outwards. This geometry enables as much lubricant as possible to remain in frictional contact for as long as possible, thus optimizing wear resistance and noise behavior.

[0033] The recesses 139 thus serve as a reservoir for the lubricant tailored to the friction partners and increase the service life of the brake module without requiring large quantities of lubricant.

[0034] The lubricant is specifically free of PFPE, PTFE and silicone, thus ensuring environmentally friendly application without harmful components.

[0035] The brake disc 130 is formed in one piece from a plastic containing carbon fibers and is preferably manufactured using an injection molding process. The plastic material of the brake disc 130 is optimized for friction combination with the thrust washers 160 and 170. The carbon fibers added as cutting material additionally enable durable and low-wear friction, so that the superior mechanical properties of the carbon fibers can be advantageously combined with the ease of processing the plastic, resulting in a reliable, lightweight, and cost-effective brake module 100.

[0036] Thanks to its one-piece plastic construction, the Brake Module 100 can be manufactured more easily and cost-effectively, as complex assembly processes and material connections are avoided. The need for an elaborate and expensive coating with one or more friction layers is eliminated. Furthermore, the plastic Brake Disc 130 is resistant to storage conditions.

[0037] More, in Fig. The six disc elements 230, 240 shown secure the positioning of the driver 2 on the spindle of the spindle drive (not shown). QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] EP 1 767 439 A2

[0027]

Claims

[1] Brake module (100) for a vehicle flap drive system with at least one first friction partner (130) and at least one second friction partner (160, 170), wherein the friction partners (130, 160, 170) each have at least one friction surface (140, 150, 180, 190) that rubs against each other during braking operation, wherein the first friction partner (130) is formed in one piece from a plastic with a carbon fiber content. [2] Brake module (100) according to claim 1, characterized by , that the first friction partner is intended as a brake disc (130) and the second friction partner as a thrust disc (160, 170). [3] Brake module (100) according to claim 1 or 2, characterized by , that a second friction partner (160, 170) is provided on each of two opposite sides of the first friction partner (130), wherein the first friction partner (130) has a friction surface (140, 150) facing each of the second friction partners (160, 170). [4] Brake module (100) according to one of claims 1 or 3, characterized by, that at least one second friction partner (160, 170) consists of, preferably non-nitrided, chromium-5 steel. [5] Brake module (100) according to any one of claims 1 to 4, characterized by , that the first friction partner (130) can be manufactured using an injection molding process. [6] Brake module (100) according to any one of claims 1 to 5, characterized by , that the friction surface (140, 150) of the first friction partner each has a number of recesses (139) for receiving a lubricant. [7] Brake module (100) according to claim 6, characterized by that the lubricant is free of PFPE, PTFE and silicone. [8] Brake module (100) according to any one of claims 1 to 7, characterized by , that the first friction partner (130) is annular and preferably has a central recess (135), wherein the central recess (135) has an approximately circular cross-section with at least two tooth sections (136) separated by recesses (137). [9] Brake module (100) according to any one of claims 1 to 8, characterized by , that the brake module (100) comprises a housing (220) in which the first friction partner (130) and the at least one second friction partner (160, 170) are guided, preferably coaxially about a central axis, wherein the brake module (100) comprises a cover disk (210) which is connected to the housing (220) by a snap-fit ​​connection such that the first friction partner (130) and the at least second friction partner (160, 170) are held in the housing (220). [10] Brake module (100) according to claim 9, characterized by, that the housing (220) comprises a number of housing slots (226) whose longitudinal axis is aligned parallel to the longitudinal axis of the drive system, wherein at least one second friction partner (160, 170) has projections (165, 175) extending radially outwards from the longitudinal axis and shaped in a complementary manner to the housing slots (226), such that the housing slots (226) and the projections (165, 175) interact in a positive-locking manner against rotation of the second friction partner (160, 170) relative to the housing (220) about the longitudinal axis. [11] Vehicle flap drive system comprising a brake module (100) according to one of the preceding claims. [12] Vehicle flap drive system according to claim 11, characterized by that the drive system is an electric spindle drive.

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