Coilover spring, spring support, motor vehicle including and manufacturing process for it

Abstract

The invention relates to a helical compression spring (2) for use in a spring support (4) for a pivotable flap (6), in particular a tailgate or trunk lid, of a motor vehicle (8), comprising a first and a second spring end (10, 12) and a plurality of coils (14) located between the first and the second spring end (10, 12), wherein at least a majority of the coils (14) are enclosed by a damping layer (18), wherein a first coil region (20) designed as a flock region is arranged at or near the first spring end (10), in which flock fibers (24) are introduced into the damping layer (18), which are held in the damping layer (18) with their anchoring regions (26) and which protrude from the damping layer (18) with their free end regions (28); and, wherein a second coiling area (22) designed as a flock fiber-free area is arranged at or near the second spring end (12).The invention also relates to a spring support (4), a motor vehicle (8) and a method for manufacturing a helical compression spring (2) for use in a spring support (4) for a pivotable flap (6), in particular a tailgate or rear cover, of a motor vehicle (8).

Description

The invention relates to a helical compression spring for use in a spring support for a pivoting flap, in particular a tailgate or trunk lid, of a motor vehicle. The invention also relates to a spring support with such a helical compression spring and a motor vehicle with such a spring support. A piston-cylinder unit with a helical compression spring is known from DE 10 2005 007 741 A1. The invention relates to a piston-cylinder unit with a piston having a piston rod and being axially displaceable in a cylinder, and with a helical compression spring encompassing at least a portion of the cylinder with radial clearance. The piston rod extends from the cylinder at a first end face on the piston rod exit side. The helical compression spring is supported on one side by the piston rod and on the other side by the cylinder. It has proven to be a disadvantage that the functionality of the piston-cylinder unit with the helical compression spring is reduced at low temperatures. It is therefore the object of the present invention to provide a helical compression spring for use in a spring support, which remains functional even at low temperatures. A motor vehicle with a tailgate and such a spring support, which remains functional at low temperatures, is also to be provided. Furthermore, a corresponding manufacturing method is to be provided. These tasks are solved by the subject matter of the independent patent claims. Advantageous further developments result from the dependent claims. A helical compression spring according to the invention for use in a spring support for a pivoting flap, in particular a tailgate or trunk lid, of a motor vehicle, comprises a first and a second spring end and a plurality of coils located between the first and the second spring end. At least a large proportion of the coils are encased by a damping layer. At or near the first spring end, a first coil region designed as a flock region is arranged in which flock fibers are embedded in the damping layer and held in place by their anchoring areas within the damping layer. The flock fibers protrude from the damping layer with their free end regions. At or near the second spring end, a second coil region designed as a flock-free region is arranged. In other words, the invention relates to a helical compression spring which is covered by a damping layer over at least a large part of the coils, in particular all coils, and is preferably flocked on only one side, that is, at or near one of the spring ends. The helical compression spring according to the invention is designed with flock fibers applied to the damping layer at or near this spring end. There is therefore a difference in flock fiber density, i.e., a flock density difference, between the two spring ends. The helical compression spring according to the invention is designed for arrangement in a spindle drive. The spring end with the flock fibers is located in an upper part of the spindle drive. In a lower part of the spindle drive, facing away from the upper part, the spring end preferably has only the damping layer with no or only a few flock fibers, i.e., a substantially flock fiber-free area. According to one of the findings underlying the invention, the inventors of the present patent applications have discovered that the impairment of the function of spring supports according to the invention at low temperatures, particularly at sub-zero temperatures, is due to water penetrating the interior of the spring support, accumulating there and freezing, which particularly impairs the functionality of the spring support when the damping layer is made of flock fibers at the point where the water collects. According to a fundamental principle of the invention, the helical compression spring is therefore designed at this point, namely at the second spring end, with a second coil section formed as a flock-fiber-free area, thereby reducing the surface wettable by water, as well as the roughness and unevenness of this surface. This results in the advantage that lower adhesive forces develop between the flock-fiber-free area and the water that has penetrated the lower part of the spindle drive than would be the case with a flocked spring end. This reliably prevents the spindle drive from icing up and becoming blocked. At the same time, by designing the first coil area, which is opposite the second flock-free coil area, as a flock area with flock fibers, effective damping of the helical compression spring can be achieved and the perceptible noises in the operation of the spring support can be reduced. Thus, a helical compression spring according to the invention can ensure the full functionality of a spring support even at low temperatures and in the event of insufficient drainage of the spindle drive, while simultaneously dampening noise. A combination of an unflocked damping layer with a flocked area in one and the same helical compression spring reliably solves both the problem of functionality at low temperatures and the noise generation problem, which is surprising. According to a further advantage of the invention, a helical compression spring according to the invention can be manufactured in a relatively simple and cost-effective manner and integrated into a spring support. According to a first embodiment, it is advantageous if the first coil section and the second coil section are adjacent to each other. This embodiment allows for a manufacturing advantage in applying the flock fibers to a portion of the spring length. According to a further embodiment, it is advantageous to arrange a transition zone between the first coil section and the second coil section, in which the flock fiber area density decreases compared to the flock fiber-free coil section. A transition zone with contrasting properties of the helical compression spring with regard to noise reduction and wettability can be advantageously achieved by a preferably gradual or continuous decrease in the flock fiber area density from the first coil section, which is designed as a flock section, to the second coil section, which is designed as a flock fiber-free section. The transition zone can preferably have a length ratio of 1:7 to 1:8 to the spring length, which is preferably in the range of 70 to 100 cm. This means that the length of the transition zone is, for example, 10 cm for a spring length of 70 cm. According to another embodiment, it is advantageous if the spring ends are formed with the damping layer and the first spring end is formed in particular with flock fibers. The damping layer allows for the suppression, or at least a reduction or attenuation, of noise. It preferably reduces noises caused by the movement of the helical compression spring, preferably due to transverse forces occurring relative to adjacent components of the spring support of the pivoting flap of a motor vehicle. By forming the first end of the spring with flock fibers, a further advantageous reduction of noise can be achieved. According to another embodiment, the spring ends can be designed without a damping layer. According to another embodiment, it is advantageous if the damping layer is a cured adhesive layer, particularly made of or containing polyurethane or synthetic resin. With this embodiment, good damping properties can be achieved and corrosion prevented. Flock fibers can be securely anchored within it. Furthermore, the embodiment of the damping layer as an adhesive layer is advantageous with regard to application and the formation of adhesive forces. This means that the adhesion of the adhesive layer to the helical compression spring and the adhesion of the flock fibers to the adhesive layer are advantageous. By using an adhesive layer based on synthetic resin or polyurethane, and thus thermosets / thermomers, the viscoelastic material behavior and high temperature resistance of these materials can be advantageously utilized. This means that a significantly high damping effect, particularly in addition to noise damping, can be achieved. According to another embodiment, it is advantageous if the flock fiber area density in the first winding area is essentially constant; or if the flock fiber area density in the first winding area is between 100 and 500 fibers / mm2, in particular between 100 and 300 fibers / mm2. The flock fiber density can preferably be determined by weighing the helical compression spring. According to another embodiment, it is advantageous if the flock fibers have a mass density of 1.0 to 1.5 g / cm2, in particular of 1.3 to 1.4 g / cm2, and if the free end areas with which the flock fibers protrude from the damping layer constitute more than 50% to 90% of the total length of the flock fibers. In other words, the thickness of the anchoring area of ​​the flock fibers is at least 10% of the total length. The thickness of the adhesive layer can preferably be at least 10% of the total length. The mass density and overall length allow for advantageous anchoring and stability of the flock fibers as well as advantageous noise reduction. Examples of flock fiber designs include synthetic flock fibers made from or based on flock fiber materials such as polyamide (nylon; PA) or polyester (PES). According to a further embodiment, it is advantageous if the flock fibers have a total length of approximately 0.5 to approximately 1.2 mm; and / or the length ratio of the first coil section to the second coil section, based on the spring length of the helical compression spring, is in the range of approximately 1:1 to approximately 1:3 or in the range of approximately 3:1 to approximately 1:1; and / or if the first coil section occupies 50 to 80% of the spring length. The overall length, i.e., the cut length, is preferably determined depending on the fiber thickness / titer. An exemplary embodiment is PES 3.3 dtex, 0.7 mm. It is still advantageous if the flock fiber-free winding area forms 10 to 20% of the length of the helical compression spring. The invention also relates to a spring support for a pivoting flap, in particular a tailgate or trunk lid, of a motor vehicle. The spring support according to the invention comprises a first pivot point, in particular on the hinge side, which is rigidly connected to a first base piece and a first cylinder tube; a second pivot point, in particular on the body side, which is rigidly connected to a second base piece and a second cylinder tube; a spindle drive for moving the pivot points relative to each other; and a helical compression spring aligned with the longitudinal axis of the spring support for pre-tensioning the two pivot points into an extended state. The first cylinder tube has a larger diameter than the second cylinder tube and surrounds the second cylinder tube in a central region of the spring support, at least when the spring support is compressed.As an alternative embodiment, the second cylinder tube has a larger diameter than the first cylinder tube and surrounds the first cylinder tube in a central region of the spring support, at least when the spring support is compressed. Furthermore, as an alternative embodiment, the helical compression spring is arranged in the spring support such that its first coil is directed towards the pivot point whose cylinder tube has the larger diameter and / or is predominantly directed upwards during the intended use of the helical compression spring. All the embodiments and advantages already explained above in relation to the helical compression spring also apply to this spring support. To avoid repetition, these will not be described separately again. According to a first embodiment, it is advantageous if the spindle drive is designed as a motor with a spindle which is provided with an external thread over at least part of its length and as an inner tube with a spindle nut having an internal thread; and if the spindle engages with its external thread in the internal thread of the spindle nut and, when the motor is operated, moves the pivot points towards or away from each other. The spindle is preferably provided with an external thread over most or most of its length. According to a further embodiment, it is advantageous if the spindle drive includes the motor and / or a gearbox and / or a brake and / or a clutch; and / or if the motor and / or the gearbox and / or the brake and / or the clutch are arranged in an inner end region of the first or second cylinder tube, in particular in the inner end region of the cylinder tube with the smaller diameter. According to a further embodiment, it is advantageous if the helical compression spring rests with one end of its flock-free damping area against a flange of the motor and with the other end of its first coil section, designed as a flock area, against the opposite base piece; and / or if the helical compression spring surrounds the spindle and the inner tube and is at least partially guided through the inner tube. The invention also relates to a motor vehicle. A motor vehicle according to the invention is designed with a pivoting flap, in particular a tailgate or a rear cover, and with a spring support which is connected with its first pivot point, in particular on the hinge side, to a hinge of the pivoting flap and which is connected with its second pivot point, in particular on the body side, to a connection point of the body, in particular on a side panel, and which is positioned such that the cylinder tube with the larger diameter and the first coil of the helical compression spring point upwards at least in one of the opening or closing states of the pivoting flap. For this motor vehicle, all the embodiments and advantages already explained above with regard to the helical compression spring apply. To avoid repetition, these steps will not be performed again separately. According to a first embodiment, it is advantageous if the spring support is arranged in a lateral water channel of the rear of the motor vehicle, at least in the closed state of the pivoting flap. The lateral water channel at the stern is preferably designed as an external channel that can fill with water. The invention also relates to a method for manufacturing a helical compression spring for use in a spring support for a pivoting flap, in particular a tailgate or rear cover, of a motor vehicle. The method comprises at least the following process steps, which are carried out in the order in which they are listed: S1: Providing a helical compression spring having: a first and a second spring end and a plurality of coils located between the first and second spring end; S2: Applying an adhesive layer to at least a majority of the coils; S3: Applying flock fibers in a first coil region of the helical compression spring, located at or near the first spring end and extending towards the second spring end, to the coils having the adhesive layer, such that no flock fibers are present in a second coil region of the helical compression spring, located at or near the second spring end and extending towards the first coil region; and S4: Curing the adhesive layer to form a damping layer. In other words, the helical compression spring is completely sprayed with adhesive along its entire length in a flocking machine in one step to form an adhesive layer. The flock fibers are then applied to at least a predetermined section of the coil in a subsequent step. The adhesive layer is preferably applied to the outer surfaces of the windings. Alternatively, it is conceivable that the adhesive layer is applied all the way around. According to a first embodiment, it is advantageous if the method includes the use of a shield to prevent the flock fibers from impacting the second winding area when applying the flock fibers to the first winding area; and / or if the shield is a Faraday cage and / or a grounded grid. In other words, the first winding area of ​​the helical compression spring, which is designed as a flock fiber-free area, is protected from impacting flock fibers by the faradaic cage or by the shielding in the inventive method. The invention is explained in more detail below with reference to exemplary embodiments and the accompanying figures. These show: Fig. 1 a top view of ten helical compression springs, according to a first embodiment; Fig. 2 a schematic representation of a damping layer with flock fibers in a partially cutaway side view, according to a further embodiment; Fig. 3 a detail III of the damping layer with flock fibers from Fig. 2 in an enlarged detail view; Fig. 4 a schematic representation of a spring support with a helical compression spring in a partially cutaway view in the longitudinal direction of the spring support, according to a further embodiment; Fig. 5 a schematic representation of an open state of a pivotable flap of a motor vehicle in a side view, according to a further embodiment; and Fig.6 A schematic representation of a closed state of a pivoting flap of a motor vehicle with a partially transparent spring support shown in a compressed state in a side view, according to a further embodiment. The figures are purely schematic and serve only to illustrate the invention. Identical elements are identified by the same reference symbols. Figure 1 shows a helical compression spring 2 in a top view. The helical compression spring 2 is suitable for use in a spring support 4 shown in Figure 3 in a pivotable flap 6 shown in Figure 4, in particular a tailgate or trunk lid, of a motor vehicle 8 shown in Figure 4. The helical compression spring 2 has a first spring end 10 and a second spring end 12. Between the first spring end 10 and the second spring end 12 is a plurality of coils 14. The plurality of coils 14 extends in a longitudinal direction 16 of the helical compression spring 2. The coils 14 are all, or at least largely, enveloped by a damping layer 18, shown in detail in Fig. 4. A first coil section 20, designed as a flocked area, is arranged near and at the first spring end 10. A second coil section 22, designed as a flock-free area, is arranged at or near the second spring end 12. The two coil sections 20 and 22 extend, in particular, over the entire length of the respective helical compression spring 2. For the sake of simplicity, neither the damping layer 18 nor the flock fibers 24 are shown on the first coil section 20, which is designed as a flock section. The first coil section 20 and the second coil section 22 can, in particular, adjoin each other, as shown. Alternatively, it is possible that a transition area, not shown here, is arranged between the first winding area 20 and the second winding area 22, in which the flock fiber density decreases from the first winding area 20 to the second winding area 22. Regarding the possibilities for the formation of the damping layer 18, the formation of the flock fibers 24 and their areal and mass density and their introduction into the damping layer 18, reference is made to the general description section. In Fig. 2, the damping layer 18 with a plurality of flock fibers 24 of a winding 14 (not shown) according to Fig. 1 of the first winding area 20, which is designed as a flock area and shown in Fig. 1, is shown in a side view. In this simplified representation, the winding 14, onto which the damping layer 18 is applied, is not shown. It is also not shown that these flock fibers 24 can extend in directions other than outwards as shown, and in particular also inwards. The flock fibers 24 are incorporated into the damping layer 18 at a flock fiber density tailored to the specific application. The flock fiber density determines the percentage coverage of the surface of the damping layer 18 with flock fibers 24. In the first winding area 20, which is designed as a flock zone, the flock fiber density can range from 100 to 500 fibers / mm², and in particular from 100 to 300 fibers / mm². Figure 3 shows in detail that the flock fibers 24 are each inserted into the damping layer 18 with their anchoring area 26. The damping layer 18 can, for example, be designed as a cured adhesive layer, in particular made of or with polyurethane or synthetic resin, and reliably and securely fixes the flock fibers 24 with their respective anchoring area 26 in it. The flock fibers 24 each protrude from the damping layer 18 with their free end region 28. This means that the free end regions 28 are preferably oriented outwards away from the damping layer 18 and thus from the coil 14 of the helical compression spring 2. The orientation of the flock fibers 24 can be exactly radial, that is, in the radial direction 30. This means that the central axis of each flock fiber 24 can be at an angle of 90° to the surface of the damping layer 18. Alternatively, the flock fibers 24 can also be arranged at different angles relative to the damping layer 18, as can be clearly seen in Fig. 3. Figure 3 schematically illustrates that the free end regions 28, with which the flock fibers 24 protrude from the damping layer 18, constitute more than 90% of the total length of the flock fibers 24. However, this is only one embodiment; other length ratios are of course also possible. Figure 4 shows a spring support 4 in a partially cutaway view. The spring support 4 extends in the longitudinal direction 16 and has two ends. Fig. 4 shows the spring support 4 in the extended state with a large distance between the two pivot points 32 and 38. The compressed state is shown in Fig. 6. A first pivot point 32 is formed at a first end of the spring support 4, located on the right in Fig. 4. The first pivot point 32 is rigidly connected to a first base piece 34 and a first cylinder tube 36. A second pivot point 38 is formed at a second end of the spring support 4, located on the left in Fig. 4. The second pivot point 38 is rigidly connected to a second base piece 40 and a second cylinder tube 42. The first cylinder tube 36 has a larger diameter than the second cylinder tube 42 and overlaps the second cylinder tube 42 in a central area 44 of the spring support 4. Alternatively, the first cylinder tube 36 can have a smaller diameter than the second cylinder tube 42 and be surrounded by it in the central area 44 of the spring support 4. The spring support 4 further comprises at least one spindle drive 46 for displacing the first pivot point 32 and the second pivot point 38 relative to each other. The spindle drive 46 comprises, starting from the second bottom piece 40 to the first bottom piece 34 in Fig. 4, viewed in longitudinal direction 16 from left to right, a motor 48, in particular an electric motor, a gearbox 50, a brake 52, optionally a coupling not shown, a spindle 54 with an external thread 58 and an inner tube 56 with a spindle nut 60 with an internal thread 62. The motor 48, the gearbox 50, the brake 52, possibly the clutch (not shown), and the spindle 54 are arranged in the second cylinder tube 42, with the end of the spindle 54 extending a short distance into the first cylinder tube 36. The inner tube 56 is arranged in the first cylinder tube 36, and the spindle nut 60 with internal thread 62 is arranged at the end of the inner tube 56 facing the second cylinder tube 42. The spindle 54 with the external thread 58 engages in the internal thread 62 of the spindle nut 60. This engagement area / the internal thread 62 is thus located near the central area 44 of the spring support 4. The spindle drive 46 extends over the entire length of the first cylinder tube 36 and the second cylinder tube 42, between the first bottom piece 34 and the second bottom piece 40. The helical compression spring 2, shown in section, is arranged within the spring support 4 such that it is surrounded radially outwards by the inner surfaces of the first cylinder tube 36 and the second cylinder tube 42, and that, viewed radially inwards, the helical compression spring 2 encloses the spindle 54 and the inner tube 56. The helical compression spring 2 is thus aligned along the longitudinal axis of the spring support, i.e., in the longitudinal direction 16. The first end 10 of the helical compression spring 2 rests against the first base piece 40. The second end 12 of the helical compression spring 2 rests against an end face of the brake 52 facing the spindle 54. In an alternative embodiment, not shown here, the spindle drive 46 may only have a motor 48, a spindle 54, and an inner tube 56, but no gearbox 50, no brake 52, and no clutch. In this case, the second spring end 12 would rest against a flange of the motor 48. The motor 48, the transmission 50 and the brake 52 are arranged in an inner end area of ​​the second cylinder tube 42 with the smaller diameter. The spindle 54 is designed as a spindle rod. The spindle 54 is furthermore provided with an external thread 58 along its entire length. Alternatively, the external thread 58 can extend only over a substantial part of the length of the spindle 54. The spindle drive 46 allows the first pivot point 32 and the second pivot point 38 to be moved towards or away from each other when the motor 48 is in operation. When the spindle 54 is rotated in one direction by the motor 48, the spindle 54 is turned into the first cylinder tube 36, so that the pivot point 32 together with the inner tube 56 is moved to the left. When the spindle 54 is rotated in the opposite direction by the motor 48, the spindle 54 is turned out of the first cylinder tube 36, so that the pivot point 32 together with the inner tube 56 is moved to the right. The spring support 4 is brought into a compressed state 64 as shown in Fig. 6 when it is turned inwards, against the pressure effect of the helical compression spring 2. The helical compression spring 2 is thereby compressed. The spring support 4 is moved into an extended position 66 as shown in Figs. 4 and 5 when it is unscrewed. The helical compression spring 2 is pulled apart and assists this extension movement through its compressive force. In the extended position of the spring support 4, a preload is achieved at the two pivot points 32, 38. The helical compression spring 2 is arranged in the spring support 4 such that the first winding area 20, designed as a flock area, is directed towards the first pivot point 32, i.e. to the right in Fig. 4 and essentially upwards in Fig. 5 and Fig. 6. Because the first cylinder tube 36, adjacent to the first pivot point 32, has the larger diameter of the two cylinder tubes 36, 42 and is positioned at the top in the vehicle 8 during installation, the ingress of water or moisture into the interior of the spring support 4 is minimized. However, in practice, water still manages to enter the interior of the spring support 4. This water then collects in the lower region of the interior of the spring support 4, directly above the brake 52. The first winding area 20, designed as a flock area, is essentially directed upwards both in the compressed state 64 of the spring support 2 shown in Fig. 6 and in the extended state 66 of the spring support 2 shown in Fig. 5. Accordingly, the second winding area 22, designed as a flock fiber-free area, is essentially directed downwards both in the compressed state 64 of the spring support 2 shown in Fig. 6 and in the extended state 66 of the spring support 2 shown in Fig. 5. For the resulting technical effects and advantages, please refer to the general description section. These are not listed again here to avoid repetition. Fig. 5 shows a motor vehicle 8 with a pivoting flap 6 designed as a tailgate in an open state 74 and with a partially transparent spring support 4 in an extended state 66 in a side view. The spring support 4 is connected at its first pivot point 32 on the hinge side to a hinge 72 of the pivoting flap 6, and at its second pivot point 38 on the body side to a connection point 70 located on a body 68. The connection point 70 of the body 68 can, for example, be located on a side panel. The spring support 4 is arranged such that the first cylinder tube 36 with the larger diameter points upwards in the open position 74 of the pivotable flap 6 shown. This means that the first cylinder tube 36 with the larger diameter is positioned higher in a vertical direction 76 than the second cylinder tube 42. Fig. 6 shows a motor vehicle 8 with a pivoting flap 6 in embodiment as a tailgate in a closed state 78 and with a partially transparent spring support 4 in a compressed state 64 in a side view. The spring support 4 is arranged such that the first cylinder tube 36 with the larger diameter points upwards in the closed state 78 of the pivoting flap 6 shown. This means that the first cylinder tube 36 with the larger diameter is positioned higher in the vertical direction 76 than the second cylinder tube 42. In a method according to the invention for manufacturing a helical compression spring 2, a helical compression spring 2 is first provided in a first process step. Then, in a second process step, an adhesive layer is applied to at least a majority of the coils 14. Subsequently, in a third process step, flock fibers 24 are introduced into a first coil region 20 of the helical compression spring 2. Finally, in a fourth process step, the adhesive layer cures to form a damping layer 18. Reference symbol list 2 Coil spring 4 Spring support 6 Pivoting flap 8 Motor vehicle 10 First spring end 12 Second spring end 14 Coil 16 Longitudinal direction 18 Damping layer 20 First coil area 22 Second coil area 24 Flock fiber 26 Anchoring area 28 Free end area 30 Radial direction 32 First pivot point 34 First base piece 36 First cylinder tube 38 Second pivot point 40 Second base piece 42 Second cylinder tube 44 Middle area 46 Spindle drive 48 Motor 50 Gearbox 52 Brake 54 Spindle 56 Inner tube 58 External thread 60 Spindle nut 62 Internal thread 64 Compressed state 66 Extended state 68 Body 70 Attachment point 72 Hinge 74 Open state 76 Vertical direction 78 Closed state QUOTES INCLUDED IN THE DESCRIPTION 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 DE 10 2005 007 741 A1

[0002]

Claims

A helical compression spring (2) for use in a spring support (4) for a pivoting flap (6), in particular a tailgate or trunk lid, of a motor vehicle (8), comprising: a first and a second spring end (10, 12); and a plurality of coils (14) located between the first and the second spring end (10, 12); wherein at least a majority of the coils (14) are enclosed by a damping layer (18); wherein a first coil region (20) designed as a flock region is arranged at or near the first spring end (10), in which flock fibers (24) are introduced into the damping layer (18), which are held in the damping layer (18) with their anchoring regions (26) and which protrude from the damping layer (18) with their free end regions (28); and wherein a second coil area (22) designed as a flock fiber-free area is arranged at or near the second spring end (12). Helical compression spring (2) according to claim 1, wherein the first winding region (20) and the second winding region (22) are adjacent to each other; or wherein a transition region is arranged between the first winding region (20) and the second winding region (22) in which the flock fiber area density decreases to the second winding region (22). Helical compression spring (2) according to one of the preceding claims, wherein the spring ends (10, 12) are formed with the damping layer (18); and wherein the first spring end (10) is formed in particular with flock fibers (12); or wherein the spring ends (10, 12) are formed without a damping layer (18). Helical compression spring (2) according to one of the preceding claims, wherein the damping layer (18) is a cured adhesive layer, in particular made of or containing polyurethane or synthetic resin. Helical compression spring (2) according to one of the preceding claims, wherein the flock fiber areal density in the first coil region (20) is substantially constant; or wherein the flock fiber areal density in the first coil region (20) is between 100 and 500 fibers / mm², in particular between 100 and 300 fibers / mm²; and / or wherein the flock fibers (12) have a mass density of 1.0 to 1.5 g / cm², in particular of 1.3 to 1.4 g / cm²; wherein in particular the free end regions (28) with which the flock fibers (12) protrude from the damping layer (18) constitute more than 50% to 90% of the total length of the flock fibers (12).and / or wherein the flock fibers (12) have a total length of about 0.5 to about 1.2 mm; and / or wherein the length ratio of the first coil section (20) to the second coil section (22) relative to the spring length of the helical compression spring (2) is in the range of about 1:1 to about 1:3 or in the range of about 3:1 to about 1:1; and / or wherein the first coil section (20) occupies 50 to 80% of the spring length. Spring support (4) for a pivotable flap (6), in particular a tailgate or trunk lid, of a motor vehicle (8), comprising: a first pivot point (32), in particular on the hinge side, which is fixedly connected to a first base piece (40) and a first cylinder tube (36); a second pivot point (28), in particular on the body side, which is fixedly connected to a second base piece (40) and a second cylinder tube (42); a spindle drive (46) for displacing the pivot points (32, 38) relative to each other; and a helical compression spring (2) aligned with the longitudinal axis of the spring support according to one of the preceding claims for pre-tensioning the two pivot points (32, 38) into an extended state (66);wherein the first cylinder tube (36) has a larger diameter than the second cylinder tube (42) and, at least in a compressed state (64) of the spring support (4), surrounds the second cylinder tube (42) in a central region (44) of the spring support (4); or wherein the second cylinder tube (42) has a larger diameter than the first cylinder tube (36) and, at least in the compressed state (64) of the spring support (4), surrounds the first cylinder tube (36) in a central region (44) of the spring support (4); or wherein the helical compression spring (2) is arranged in the spring support (4) such that its first coil region (20) is directed towards the pivot point (32, 38) whose cylinder tube (36, 42) has the larger diameter and / or is predominantly directed upwards in the intended use of the helical compression spring (2). Spring support (4) according to claim 6, wherein the spindle drive (46) is designed as a motor (48) with a spindle (54) which is provided with an external thread (58) over at least part of its length and as an inner tube (56) with a spindle nut (60) with an internal thread (62); wherein the spindle (54) engages with its external thread (58) in the internal thread (62) of the spindle nut (60) and, when the motor (48) is operated, moves the pivot points (32, 38) towards each other or away from each other. Spring support (4) according to claim 7, wherein the spindle drive (46) comprises the motor (48) and / or a gearbox (50) and / or a brake (52) and / or a clutch; and / or wherein the motor (48) and / or the gearbox (50) and / or the brake (52) and / or the clutch are arranged in an inner end region of the first or second cylinder tube (36, 42), in particular in the inner end region of the cylinder tube (36, 42) with the smaller diameter; and / or wherein the helical compression spring (2) bears with one spring end (10, 12) of the flock-free damping region (18) against a flange of the motor (48) and with its other spring end (10, 12) of the first winding region (20) against the opposite base piece (34, 40); and / or wherein the helical compression spring (2) surrounds the spindle (54) and the inner tube (56) and is guided at least partially through the inner tube (46). Motor vehicle (8) with a pivotable flap (6), in particular a tailgate or a trunk lid, and with a spring support (4) according to one of claims 6 to 8, wherein the spring support (4) is connected with its first, in particular hinge-side pivot point (32), to a hinge (72) of the pivotable flap (6); wherein the spring support (2) is connected with its second, in particular body-side pivot point (38), to a connection point (70) of the body (68), in particular to a side panel; wherein the spring support (2) is positioned such that the cylinder tube (36, 42) with the larger diameter and the first coiling region (20) of the helical compression spring (2) points upwards at least in one of the opening state (74) or the closed state (74) of the pivotable flap (6). Motor vehicle (8) with a pivoting flap (6) according to claim 9, wherein the spring support (4) is arranged in a lateral water channel of the rear of the motor vehicle (8) at least in the closed state (78) of the pivoting flap (6). Method for manufacturing a helical compression spring (2) for use in a spring support (4) for a pivoting flap (6), in particular a tailgate or trunk lid, of a motor vehicle (8), comprising the following steps: providing a helical compression spring (2) having: a first and a second spring end (10, 12); and a plurality of coils (14) located between the first and the second spring end (10, 12); applying an adhesive layer to at least a majority of the coils (14);Applying flock fibers (24) to the coils (14) having the adhesive layer in a first coil region (20) of the helical compression spring (2), which is located at or near the first spring end (10) and extends towards the second spring end (12), such that no flock fibers (24) are present in a second coil region (22) of the helical compression spring (2), which is located at or near the second spring end (12) and extends towards the first coil region (20); and curing the adhesive layer to form a damping layer (18). The method of claim 11, wherein the method further comprises the use of a shield to prevent the flock fibers (24) from striking the second winding region (22) when applying the flock fibers (24) to the first winding region (20); and / or wherein the shield is a faradaic cage and / or a grounded grid.

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