Device and method for reducing noise of a linear damper

Abstract

By providing a contact area made of a material having a lower modulus of elasticity than the material of the rest of the housing in the region of the housing surrounding the rotary damper, undesirable noise ("clicking" / "rattling") can be reduced when switching from the opening movement to the closing movement of the glove box cover or vice versa.

Description

[0001] A device for reducing noise in a housing of a linear damper and a method of providing such a device are discussed.

[0002] Linear dampers comprising a rotary damper are used to slow down or dampen the movement of a component, for example a glove box cover or a movable flap. Such linear dampers with a rotary damper contained therein are described, for example, in the patent documents EP 0 846 886 B1, EP 1 344 958 B1 and DE 10 2006 000 950 B4. Conventional rotary dampers have a rotor which is rotatably mounted inside the rotary damper. When the rotor rotates in the rotary damper, a damping of the braking is provided by a braking fluid, for example silicone oil, between the rotor and the outer wall of the rotary damper. Usually, a pinion is on the rotor shaft and engages with a tooth segment which is, for example, part of a rack. Such a rotary damper is usually attached to a fixed component of the housing. Furthermore, a linear guide for the rack is provided which is mounted such that it can pivot about the axis of the rotor shaft and keeps the rack engaged with the pinion regardless of the rotational position of the rack. The guide enables a translational movement of the rack in the guide and thus a corresponding rotation of the pinion. Any pivoting of the rack is absorbed by the rotating guide. Thus, any movement of the component to be damped results in a linear movement in the guide and a corresponding damping exertion via the rotary damper. Precise guidance of the rack prevents noise, ensures effective engagement with the damper and reduces possible wear.

[0003] Since the rotary damper can rotate in the housing of the guide, the rotary damper is provided with structures on its entire outer circumference with which an engagement with the surrounding housing of the guide can be achieved. Usually, the outer circumference of the rotary damper is embodied like a spur gear. On the inside of the housing surrounding the rotary damper, a corresponding receiving structure is embodied which usually does not extend over the entire inner circumference of the housing. Usually, only two or four teeth are provided. These teeth are provided at the position at which the rotary damper rests on the housing during the movement of the pinion on the rack. Thus, the teeth of the rotary damper engage with the toothed part on the inner circumference side of the housing of the guide.

[0004] If the direction of movement of the housing component to be damped is reversed, for example when an open glove box cover is closed, the rotary damper lifts off the inner wall of the housing due to a linear movement of the rotary damper of about 1 mm at the change of direction and then hits again on the opposite side of the inner wall of the housing. This results in a short noise ("clicking sound" / "crackling sound" or "clattering sound") at the change of direction of the structural element to be damped.

[0005] It is furthermore possible that noise occurs also during movement in the damping direction. For example, if the glove box cover is opened (damper still in idling position) or if the cover is stopped and slightly lifted during the opening movement (i.e. in the damping direction), the rotary damper enters an idling state in which the teeth are not in engagement. This is because the damper is first lifted off the housing upon reverse movement. Thereafter, when the opening movement is resumed, the teeth of the rotary damper again engage with the teeth in the toothed portion on the inner peripheral face of the housing of the guide. This can cause the tooth tips of the housing and the tooth tips of the rotary damper to come into contact with each other before re-engagement. This movement also produces a brief noise ("click" or "clack"). This noise is perceived as being annoying and useless. The movement process can also appear to be unsmooth, which is likewise perceived as being unpleasant.

[0006] In view of this, it is an object of the present application to improve the linear damper in terms of noise generation and smoother movement process.

[0007] A further object is to provide an improved method for manufacturing a housing of a linear damper.

[0008] Therefore, a housing of a linear damper is provided, which forms a guide for a rotary damper and which is provided with at least one engagement element, the longitudinal extension of which extends parallel to the axial direction of the rotational movement of the rotary damper, wherein the rotary damper is provided with an outer structure, which forms a corresponding engagement element, which is configured to correspond to the engagement element, and wherein a contact area of the at least one engagement element, in which the corresponding engagement element of the rotary damper comes into contact with the engagement element of the housing upon movement in the movement direction, is formed from a material having a lower modulus of elasticity than the housing.

[0009] With such a housing of a linear damper, the generation of noise during the opening movement of a moving element, such as a glove box cover, can be reduced by providing contact areas made of a material having a lower modulus of elasticity than the surrounding housing. During the opening movement of the moving element, such as a glove box cover, the rotary damper engages with the housing. When the movement of the glove box cover is stopped or reversed, the rotary damper moves away from the side of the housing against which the rotary damper is resting. Thus, the rotary damper enters a state in which it is in an idling position in relation to the housing in the direction of movement. Subsequently, when the movement is started again, the rotary damper comes into contact with the segments of the housing again. In order to eliminate the annoying click noise, the contact areas of the segments of the housing with which the rotary damper comes into contact are made of a material having a lower modulus of elasticity than the housing. Thus, these contact areas are softer than the rest of the housing. This leads to a damping of the noise and also to a smoother movement process. Furthermore, the pressure load of the parts of the housing covered by the contact areas is distributed evenly.

[0010] The engagement element and the counter engagement element can each have a structure configured to engage with one another in a form fit, wherein the structure is formed, for example, in the form of a toothing.

[0011] In the context of the present application, all suitable profiles or toothing are considered to be structures for engaging with one another in a form fit. They can be designed rectangular, wavy, trapezoidal or triangular.

[0012] In one embodiment, a housing is provided, wherein at least one tooth is used as an engagement element.

[0013] When as few structural elements, such as teeth, are in contact with the rotary damper, the structure of the housing can be simplified and thus the manufacture of the housing can be simplified.

[0014] In another embodiment, a housing is provided, wherein the contact areas have a thickness selected such that the rotary damper still reliably engages with the housing when a material having a lower modulus of elasticity than the modulus of elasticity of the housing and a material which is less wear-resistant than the material of the rest of the housing is worn away.

[0015] In this way, even with the use of a material having a lower modulus of elasticity than the material of the rest of the housing, it is possible to ensure a long service life.

[0016] In this embodiment, the thickness or the covering length of the contact areas is approximately 0.1 mm or 0.15 mm or 0.3 mm to 0.4 mm or 0.6 mm and preferably 0.2 mm to 0.5 mm.

[0017] With this covering length, on the one hand a good service life is achieved and on the other hand a good noise damping is achieved.

[0018] In another embodiment, a housing is provided, wherein the contact area is arranged in a recess of the housing and the size of the recess does not exceed the size of the contact area.

[0019] In another embodiment, a housing is provided, wherein in a multi-component injection molding process the housing is formed from at least one first component and the contact area is formed from at least one second component having a lower modulus of elasticity than the at least one first component forming the rest of the housing.

[0020] The use of a multi-component injection molding process simplifies the manufacture of a housing with a contact area having a lower modulus of elasticity than the rest of the housing and reduces the number of manufacturing steps required.

[0021] In another embodiment, a housing is provided, wherein the contact area is arranged on a side surface.

[0022] If the contact area is arranged on a side surface, for example of a tooth or an extension of the housing, the consumption of material having a lower modulus of elasticity than the material of the rest of the housing is reduced. Here, the term "side surface" is understood to mean that the specified surface has an angle to the inner peripheral surface of the housing. Such a side surface is, for example, a side surface of a trapezoidal or triangular tooth or a transition area between two inner peripheral surfaces of the housing having different radii.

[0023] In another embodiment, a housing is provided, wherein the contact area is arranged on an inner peripheral surface of the housing.

[0024] If the inner peripheral surface of the housing has a contact area made of a material having a lower modulus of elasticity than the rest of the housing, it is possible to more reliably prevent the noise that occurs when the rotational damper comes into contact with the housing.

[0025] In another embodiment, a housing is provided, wherein the contact area is arranged on a portion of the inner peripheral surface and / or a portion of the side surface of the housing.

[0026] In another embodiment, a housing is provided, wherein the contact area covers three quarters or half or a quarter of the inner peripheral surface and / or the side surface of the housing in the axial direction.

[0027] In another embodiment, a housing is provided, wherein the material having a lower modulus of elasticity than the housing is a thermoplastic elastomer (TPE).

[0028] The use of a thermoplastic elastomer as a material having a lower modulus of elasticity than the material of the rest of the housing makes it possible to achieve a particularly large noise reduction.

[0029] The housing is formed from a material such as polyethylene (PE), polypropylene (PP) or polyamide (PA) which has good adhesion properties for TPE.

[0030] A method for manufacturing a housing enclosing a rotational damper by introducing a component provided with a contact area, wherein the rotational damper is in contact with the housing on the contact area, wherein the contact area of the component is made of a material having a lower modulus of elasticity than the housing.

[0031] Furthermore, a method for manufacturing a housing enclosing a rotational damper by molding a contact area on the remaining part of a housing which has already been preformed, wherein the rotational damper is in contact with the housing on the contact area, and wherein the contact area is formed of a material having a lower modulus of elasticity than the remaining part of the housing.

[0032] Another method for manufacturing a housing enclosing a rotational damper by means of a multi-component injection molding process is performed by the following steps:

[0033] injecting at least one component for forming the housing, and

[0034] injecting at least one further component for forming a contact area in which the rotational damper is in contact with the housing, wherein the at least one further component is formed of a material having a lower modulus of elasticity than the material of the remaining part of the housing.

[0035] According to the above-mentioned methods, a housing of a rotational damper with additional functionality of noise reduction can be manufactured particularly simply, i.e. with fewer manufacturing steps.

[0036] Any of the above-mentioned methods can be improved when the material having a lower modulus of elasticity than the housing is a thermoplastic elastomer.

[0037] By using a thermoplastic elastomer as the material having a lower modulus of elasticity than the material of the remaining part of the housing in one of the above-mentioned methods, a particularly large noise reduction can be achieved.

[0038] The apparatus and the method are shown in detail below with reference to the drawings.

[0039] Figure 1 A housing of a damper comprising a rotational damper is shown, which housing has two abutment faces and a toothed damper insert;

[0040] Figure 2 A housing of a damper comprising a rotational damper is shown, which housing has an inner row of teeth for engaging with a toothed damper insert;

[0041] Figure 3 A component for insertion into a housing is shown having a contact area formed of a material having a lower modulus of elasticity than the housing;

[0042] Figure 4 A housing is shown in which all surfaces of the side of the tooth are provided with a material having a lower modulus of elasticity than the housing,

[0043] Figure 5 A housing is shown in which half of the surfaces of the side of the tooth are provided with a material having a lower modulus of elasticity than the housing;

[0044] Figure 6 A housing is shown in which half of the surfaces of the side of the tooth are provided with a material having a lower modulus of elasticity than the housing;

[0045] Figure 7 A housing is shown in which three quarters of the surfaces of the side of the tooth are provided with a material having a lower modulus of elasticity than the housing;

[0046] Figure 8 is Figures 4 to 7 a further view of the housing in

[0047] In Figure 1 and Figure 2 two rotary dampers 2 as well as the respective housings 1 of the dampers are shown. These housings 1 accommodate the rotary dampers 2 in an inner cavity 6. The housings 1 provide an exact lateral guidance of the rotary dampers. The housings 1 can be connected with further structural elements, not shown, by flanges 4 and 5. The rotary dampers 2 and the housings 1 are connected with a toothed rack, not shown, by pinions 20. The toothed rack or the flanges serve for connection with further structural elements, like a glove box cover, or for connection with the rest of the structure, which, for example in the case of a glove box cover, can be the rest of the dashboard. Since the housings 1 form an exact guidance for the rotary dampers 2, it is ensured that the pinions 20 connected with the rotary dampers engage exactly into the toothed rack.

[0048] In Figure 1 and Figure 2 the rotary dampers 2 are toothed. In Figure 1 each tooth is separated by a slot 7, i.e. a slot-shaped recess, and has a trapezoidal cross section, in Figure 2 the rotary dampers are provided with an outer toothing 8, in which each tooth has a triangular cross section. In Figure 1In this case, the housing 1 has an expansion 9, i.e. a region in which the radius of curvature of the inner peripheral surface of the housing 1 is greater than the radius of curvature of the inner peripheral surface of the remainder of the housing. At the transition of this region 9 to the remainder of the inner peripheral surface of the housing, the side faces (engagement side faces) 10 and 11 form engagement regions into which the teeth of the rotational damper 2 having a trapezoidal cross section can engage.

[0049] In Figure 2 In this case, the toothed portion 8 on the rotational damper 2 is embodied with teeth having a triangular cross section. Correspondingly, a toothed portion 12 is provided on the inner peripheral surface of the housing 1. This toothed portion 12 comprises at least one tooth, but preferably two teeth, as is shown in the following figures. Furthermore, as is shown in Figure 2 four teeth can be used for the toothed portion 12.

[0050] In Figure 1 and Figure 2 In this case, the direction of movement is from top to bottom. When the rotational damper and the housing are used, for example, for a glove box cover, the rotational damper 2 rests on the expansion 9 or the toothed portion 12 when the glove box cover is opened. When the glove box cover is closed, as is shown in Figure 1 and Figure 2 the rotational damper 2 rests on the segment of the lower inner peripheral surface of the housing which is opposite the expansion 9 or the toothed portion 12. Another possible operating state occurs when the direction of movement is reversed. After the glove box cover has been completely opened or partially opened, the rotational damper 2 is still resting on the expansion 9 or the toothed portion 12. When movement in the other direction, i.e. in the closing direction of the glove box cover, is initiated, the rotational damper 2 lifts off the expansion 9 or the toothed portion 12, instead of already resting on the segment of the inner peripheral surface of the housing which is in the lower part in the figures. The rotational damper 2 can thus rotate freely in the housing 1. This state is therefore referred to as idling.

[0051] In Figure 3The diagram illustrates one embodiment of the housing 1, in which the inner peripheral surface 19 of the component 3, or insert 3, is coated with a material having a lower elastic modulus than the rest of the housing. Therefore, the inner peripheral surface 19 of the housing component 3 has the desired noise reduction characteristics. Furthermore, a segmental support element 21 is provided in the tooth region. This support element 21 is optional and particularly configured to support the rotary damper 2 and prevent tilting of the rotary damper. The inner peripheral surface 19 can also be designed to support the rotary damper 2 and prevent tilting of the rotary damper. To achieve sufficient stability, the teeth 13, 14 must be made of the same material as the rest of the housing, and the same applies to the surface of the housing component 3 facing away from the rotary damper. Therefore, the teeth 13, 14 are also coated with the same material used to coat the inner peripheral surface. Thus, the entire surface of the contact area is made of a material having a lower elastic modulus than the rest of the housing. The term "contact area" is understood herein to refer to such a region of the inner peripheral surface in which... Figure 1 or Figure 2 The rotational damper 2 can contact the housing 1 during the movement of the glove box cover.

[0052] exist Figure 5 The middle shows Figure 3 The insert 3 shown is inserted into the housing 1 and can reduce noise.

[0053] exist Figures 5 to 7 The figure shows another embodiment of the housing 1, in which only a portion of the teeth 13 and 14 are provided with contact areas 17 and 18. Good noise reduction can be achieved even if the entire inner peripheral surface of the housing 1 is not provided with contact areas formed of a material having a lower elastic modulus than the rest of the housing material, while saving material with a lower elastic modulus than the rest of the housing material. It goes without saying that the contact areas 17 and 18 need not be located at the ends of the teeth 13 and 14, which are shown as the lower ends in the figure, but can also be located at the center of the axial extension of the teeth 13 and 14 or at the upper ends of the teeth. Furthermore, the dividing line between the contact areas 17 or 18 does not necessarily have to extend along the peripheral direction of the inner surface of the housing. The dividing line can also extend in the axial direction or other directions.

[0054] Not drawn to scale Figures 5 to 7 As shown, the contact area represents the thickened portion of the tooth. If the coverage length of the material in the contact area is preferably 0.2 mm, then the material with a lower elastic modulus extends beyond the tooth surface into the area where the contact area is not provided by 0.2 mm. Therefore, the side of the tooth has a 0.2 mm deep groove in an invisible area below the contact area, into which the material for the contact area is introduced.

[0055] exist Figure 5As shown, approximately half of the tooth surfaces of teeth 13 and 14 are provided with contact areas 17 and 18. Figure 6 In the case of teeth 13 and 14, only about a quarter of the surface is provided with contact areas 17 and 18, thereby enabling exceptionally high material savings with a lower elastic modulus than the rest of the housing. Figure 7 In the middle, three-quarters of the surface of teeth 13 and 14 are provided with contact areas 17 and 18, thereby relative to the... Figure 5 and Figure 6 The housing shown provides improved noise reduction.

[0056] Figures 5 to 7 The implementation method is suitable for manufacturing the contact area in a two-step process. For example, the housing is first made of plastic (e.g., PA, PBT, PE, PP, or ABS) by injection molding. Then, the contact area is formed onto the housing, for example, by applying a material having a lower elastic modulus than the rest of the housing material through coating, for example by spraying, from a nozzle.

[0057] also, Figures 5 to 7 The embodiments described herein are suitable for materials used in multi-component injection molding processes to jointly manufacture the actual shell and for materials having a lower elastic modulus than the rest of the shell. This allows the shell according to the invention to be manufactured in a particularly small number of manufacturing steps.

[0058] Thermoplastic elastomers are preferred as materials having a lower elastic modulus than the rest of the shell.

[0059] exist Figure 8 The housing 1 is shown, in which the areas opposite teeth 13 and 14 can be seen. Cylindrical surfaces extend from the contact ribs 15 and 16 shown, and these cylindrical surfaces remain on the damper when it is in the idling position.

[0060] Furthermore, it can be proposed that contact areas 17 and 18 are disposed in grooves in housing 1, and the size of the grooves does not exceed the size of the contact areas.

[0061] Contact areas 17 and 18 can be located on the sides 10, 11, 13, and 14.

[0062] Contact areas 17 and 18 can be arranged on the inner peripheral surface 19 of the housing 1.

[0063] According to a method for manufacturing a housing 1 that surrounds a rotary damper 2, the manufacturing is carried out by introducing an additional component 3 having a contact area in which the rotary damper 2 contacts the housing, wherein the component is made of a material having a lower elastic modulus than the housing.

[0064] According to a further method for manufacturing the housing, the manufacturing can be carried out by molding a contact area onto the remaining part of the housing which has already been preformed, in which contact area the rotational damper 2 is in contact with the housing 1, wherein the contact area is formed from a material having a lower modulus of elasticity than the remaining part of the housing.

[0065] Furthermore, it is possible to form the housing 1 by injection molding at least one component and to form the contact areas 17, 18 in which the rotational damper is in contact with the housing by injection molding at least one further component by means of a multi-component injection molding process, wherein

[0066] the at least one further component is formed from a material having a lower modulus of elasticity than the material of the remaining part of the housing.

[0067] It is possible to use a thermoplastic elastomer as the material having a lower modulus of elasticity than the housing.

[0068] List of reference signs

[0069] 1 housing

[0070] 2 rotational damper

[0071] 3 additional component

[0072] 4, 5 flange

[0073] 6 inner chamber

[0074] 7 slot (slot-shaped recess)

[0075] 8 toothing

[0076] 9 expansion

[0077] 10, 11 engagement side

[0078] 12 toothed portion

[0079] 13, 14, 15, 16 tooth

[0080] 17, 18 contact area

[0081] 19 inner peripheral surface of the housing

[0082] 20 pinion

[0083] 21 support element

Claims

1. Housing (1) of a linear damper, which housing forms a guide for a rotary damper (2), comprising at least one engagement element (10, 11, 13, 14, 15, 16), wherein the at least one engagement element is elongated such that a longitudinal extension of the engagement element extends parallel to an axial direction of a rotational movement of the rotary damper (2), wherein the rotary damper (2) is provided with an outer structure forming a counter engagement element (8) which is designed to correspond to the engagement element, and wherein a contact area (17, 18) of the at least one engagement element (10, 11, 13, 14, 15, 16) is at least partially formed by a material having a lower modulus of elasticity than the housing (1), in which contact area the counter engagement element (8) of the rotary damper (2) comes into contact when moving in the direction of movement with the engagement element (10, 11, 13, 14, 15, 16) of the housing (1); wherein the engagement element is formed by a plurality of teeth and the counter engagement element is formed by a plurality of teeth arranged around a circumference of the rotary damper, such that each tooth of the rotary damper engages with the teeth of the engagement element.

2. Housing (1) according to claim 1, wherein the material having a lower modulus of elasticity than the housing is a cover layer of the contact area (17, 18) and has a thickness of 0.1 mm to 0.6 mm.

3. Housing (1) according to claim 1, wherein the housing (1) is formed from at least one first component and the contact area (17, 18) is formed from at least one second component having a lower modulus of elasticity than the at least one first component.

4. Housing (1) according to claim 1, wherein the contact area (17, 18) is arranged on and / or in a lateral face (10, 11, 13, 14) and / or an inner circumferential face (19) of the housing (1).

5. Housing (1) according to claim 4, wherein the contact area (17, 18) covers three quarters or half or a quarter of the inner circumferential face (19) and / or lateral face (10, 11, 13, 14) of the housing (1) in the axial direction.

6. Housing (1) according to claim 1, wherein the material having a lower modulus of elasticity than the material of the housing (1) is a thermoplastic elastomer.

7. Method for manufacturing a housing surrounding a rotary damper, the method being performed using a multi-component injection molding process, by injection molding at least one component to form a housing structure made of a first material, and by injection molding at least one further component to form a contact area of the housing structure made of a second material having a lower modulus of elasticity than the first material. ​ ​ ​ ​ ​ ​ ​ ​ wherein ​ ​ by injection molding at least one further component onto the housing structure to form a contact area on the housing structure, the contact area being made of a second material having a lower modulus of elasticity than the first material, the contact area being located at a position where the rotational damper contacts the housing, the contact area being formed by a plurality of teeth, the plurality of teeth being elongated in a direction parallel to an axis of rotation of the rotational damper; wherein the second material is a thermoplastic elastomer.

8. The method according to claim 7, further comprising: introducing an additional component (3) comprising the contact area, wherein the additional component is made of a material having a lower modulus of elasticity than the first material.

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