Compressor system for a breakdown kit, breakdown kit with such a compressor system, and method for sealing a vehicle tire with such a compressor system

Description

[0001] The invention relates to a compressor system for a breakdown assistance kit according to the preamble of patent claim 1, a breakdown assistance kit according to the preamble of patent claim 6 and a method for sealing a vehicle tire according to the preamble of patent claim 8.

[0002] Compressor systems for breakdown kits, as well as breakdown kits with compressors, are known in the art and are typically used in portable devices for air compression. A compressor is used to generate compressed air, which is used to pump a sealant into a vehicle tire in the event of a puncture and / or to fill the vehicle tire with air after sealing. The compressors typically comprise at least one motor and a cylinder with a reciprocating compressor driven by a slider-crank mechanism. The cylinder is typically formed from metal to ensure the material is sufficiently strong for the reciprocating compressor to compress the air in the pumping chamber. A disadvantage is that the requirements for such a material severely restrict the shape of the cylinder, thus generating high production costs.Typically, relief or pressure relief valves are used to limit the maximum pressure to be generated. However, the state of the art also describes other options for limiting the maximum pressure.

[0003] EP2918834B1, for example, discloses a compressor system with a motor, a piston, and a cylinder without the use of a relief valve. The maximum pressure is limited not by a relief valve, but by the appropriate selection of the compression volume. A disadvantage of such compressor systems is that their design is only designed for high compression volumes.

[0004] In the present invention, a low compression volume is considered to be greater than or equal to 0.8. A high compression volume is considered to be in the range below 0.8, particularly in the range from 0.3 to 0.8.

[0005] The object of the present invention is to provide a compressor system for a breakdown kit that enables the limitation of the maximum pressure in the range of the average compression volume. Furthermore, the object of the invention is to provide a breakdown kit that enables the limitation of the maximum pressure in the range of the average compression volume. A further object of the invention is to provide a method for sealing vehicle tires, by which vehicle tires can be sealed by limiting the maximum pressure in the range of the average compression volume.

[0006] The object of the invention is achieved by a compressor system for breakdown assistance kits having the features of patent claim 1, by a breakdown assistance kit having the features of patent claim 6 and by a method for sealing vehicle tires having the features of patent claim 8.

[0007] The object of the invention is achieved by a compressor system for a breakdown kit in which a supply pressure of compressed air is controlled without using a relief valve, comprising a motor, a piston driven by the motor via a crank mechanism, and a cylinder component having a cylinder main body, a pumping chamber in which a piston is reciprocally movable from a bottom dead center to a top dead center and compresses air, and a receiving chamber for receiving the compressed air compressed in the pumping chamber through an air release valve, wherein the cylinder main body is elastically deformable with increasing pressure, wherein the cylinder main body is deformable to such an extent that the compression volume V2 of the cylinder satisfies the following expression (a), 0.3×V1×P0 / PP−P0= <V2<0,8×V1×P0 / PP−P0 where V1 is a stroke volume, which is a cylinder volume while the piston moves from the bottom dead center to the top dead center, V2 is a compression volume, which is a cylinder volume when the piston is at the top dead center, and P0 is an air pressure.

[0008] Advantageously, a compressor system according to the invention can be used at medium compression volumes by using a cylinder main body that is elastically deformable with increasing pressure, thereby enabling significantly more cylinder designs and consequently reducing production costs. According to the invention, the maximum pressure in the cylinder can be achieved despite an elastically deformable cylinder main body by satisfying expression (a). Such compressor systems can build up sufficiently constant pressure without the use of relief valves to ensure safe use in a breakdown kit.

[0009] According to the invention, a cylinder body is elastically deformable with increasing pressure, in that the wall of the cylinder body can yield with increasing pressure. It is conceivable that the side walls of the pumping chamber bulge outward at increased pressure. As the pressure decreases, the cylinder body returns to its original shape. Advantageously, such systems are ideally suited for compression volumes below 0.8. However, such a design is not suitable for limiting the maximum pressure for compression volumes greater than 0.8.

[0010] In a preferred embodiment of the invention, the cylinder main body comprises at least one plastic. Plastics are particularly suitable because they are easy to process and are usually deformable. Different plastics are conceivable. At least one plastic selected from the group consisting of polyamide, polyethylene, polycarbonate, and polypropylene is particularly suitable. Such plastics have particularly suitable flexibility, which means they can be used as the material for a cylinder component. Other common flexible plastics that are usually used for a cylinder are also suitable. It is advantageous that such plastics are elastically deformable, which makes such compressor systems suitable for use without relief valves in order to enable the limitation of the maximum pressure in the range of the high compression volume.

[0011] In a particularly preferred embodiment, the cylinder main body comprises only plastic, whereby the cylinder main body has a particularly good elastic deformability in order to enable the aforementioned advantages.

[0012] In a further preferred embodiment, the wall of the cylinder main body has a thickness in the range of 1 to 3 mm. The wall of the cylinder main body is advantageously in the range of 1 to 3 mm so that it is elastically deformable. In contrast to the requirements of a cylinder main body in the prior art, in which it should be stable in order to achieve a maximum pressure in the range of low compression volumes, according to the invention, an elastically deformable wall of a cylinder main body limits the maximum pressure in the range of the medium compression volume.

[0013] In a preferred embodiment, the cylinder main body wall of the pumping chamber is elastically deformable.

[0014] Furthermore, the material of the cylinder wall preferably has a flexural modulus in the range of 0.5 to 10 GPa. It has been found that a cylinder wall of the cylinder main body with a flexural modulus in this range is particularly well suited for limiting the maximum pressure in the high compression volume range. In a particularly preferred embodiment, the flexural modulus is in the range of 1 to 1.5 GPa.

[0015] Furthermore, the object is achieved by a breakdown assistance kit, wherein the breakdown assistance kit comprises a described compressor system and a sealing device, wherein the sealing device has a sealing agent for sealing a vehicle tire. Advantageously, the maximum pressure in the range of high compression volumes in a breakdown assistance kit can be limited. This is particularly advantageous for breakdown assistance kits, since the design of the compressor should usually be cost-effective and limited to the essential properties. A breakdown assistance kit according to the invention with a described compressor system enables simple production, for example of cylinder bodies made of plastics. Compressor systems without relief valves are advantageous because the risk of backflow is reduced if the air outlet becomes blocked.

[0016] Further advantages mentioned with regard to the previous compressor system also apply, vice versa, to the breakdown assistance kit.

[0017] In a preferred embodiment, the compressor system is connectable to the sealant device. Breakdown kits are typically divided into sets with and without a sealant device. The sealant device in breakdown kits with a sealant device is first connected to the compressor system before use. The compressor system then generates air pressure, which pumps the sealant into the vehicle tire to seal the tire.

[0018] Furthermore, the object is achieved by a method for sealing a vehicle tire using a described compressor system or a described puncture kit, comprising at least the following steps: i) building up an overpressure by a piston in the compressor system, wherein the compression volume V2 of the cylinder satisfies the following expression (a), 0,3 × V1 × P0 / PP − P0 = < V2 < 0,8 × V1 × P0 / PP − P0 where V1 is a displacement volume, which is a cylinder volume while the piston moves from the bottom dead center to the top dead center, V2 is a compression volume, which is a cylinder volume when the piston is at the top dead center, and P0 is an air pressure, and ii) delivering a sealing agent into a vehicle tire by means of overpressure built up in the compressor system.

[0019] The method according to the invention for sealing a vehicle tire with a sealant is advantageous because it allows for limiting the maximum pressure even for high compression volumes. Even with a compressor design, particularly one made of plastic, a relief valve can be omitted, reducing the risk of backflow if the air outlet becomes blocked. Character description

[0020] Further details and advantages will become apparent from the following description of the embodiments in conjunction with the drawings. Figure 1a shows a cross-sectional view of a cylinder main body with a piston at bottom dead center, and Figure 1b shows a cross-sectional view of a cylinder main body with a piston at top dead center.

[0021] Figure 1a shows a cross-sectional view of a cylinder main body 1 with a piston 2 and an air inlet opening 3 and an air outlet opening 4, such a structure being used in a compressor and / or breakdown kit according to the invention. The two side walls 5 of the cylinder main body 1 are elastically deformable with increasing pressure. Figure 1athe piston 2 is at bottom dead center, with the side walls 5 of the cylinder main body 1 not deformed. With increasing pressure, the side walls 5 deform outwards in the area of ​​the pump chamber 6 until the piston 2 reaches top dead center ( Figure 1b ). The process of generating maximum pressure and returning to the bottom dead center of piston 2 is reversible. List of reference symbols:

[0022] 1Cylinder main body 2Piston 3Air inlet port 4Air outlet port 5Side walls 6Pumping chamber

Claims

1. Compressor system for a puncture repair kit, in which a supply pressure of compressed air is controlled to a specified pressure PP without the use of a relief valve, comprising - a motor, - a piston (2), which is driven by the motor via a crank mechanism and - has a cylinder component with a cylinder main body (1) having a pump chamber (6), in which the piston (2) is movable to and fro from a bottom dead centre to a top dead centre and compresses air, and a receiving chamber for receiving the compressed air compressed in the pump chamber (6) through an air discharge valve (4), characterized in that the cylinder main body (1) is elastically deformable as the pressure increases, the cylinder main body (1) being deformable to such an extent that the compression volume V2 of the cylinder fulfils the following expression (a) 0.3 × V 1 × P 0 / PP − P 0 = < V 2 < 0.8 × V 1 × P 0 / PP − P 0 0.3 x V1 x P0 / (PP-P0) = < V2 < 0.8 x V1 x P0 / (PP-P0) where V1 is a swept volume which is a cylinder volume while the piston (2) moves from the bottom dead centre to the top dead centre, V2 is a compression volume which is a cylinder volume when the piston (2) is located at the top dead centre, and P0 is an air pressure.

2. Compressor system according to Claim 1, characterized in that the cylinder main body (1) comprises at least one plastic, in particular polyamide.

3. Compressor system according to Claim 1 or 2, characterized in that the wall of the cylinder main body (1) has a thickness in the range of 1 to 3 mm.

4. Compressor system according to any one of the preceding claims, characterized in that the cylinder main body wall (5) of the pump chamber (6) is elastically deformable.

5. Compressor system according to any one of the preceding claims, characterized in that the material of the cylinder main body wall (5) has a bending modulus in the range of 0.5 to 10 GPa, preferably 1 to 1.5 GPa.

6. Puncture repair kit comprising a compressor system according to any one of the preceding claims and a sealant device, wherein the sealant device has a sealant for sealing a vehicle tyre.

7. Puncture repair kit according to Claim 6, characterized in that the compressor system is connectable to the sealant device.

8. Method for sealing a vehicle tyre using a compressor system according to any one of Claims 1 to 5 or a puncture kit according to Claim 6 or 7, comprising at least the following steps: i) building up a positive pressure by means of a piston (2) in the compressor system, wherein the compression volume V2 of the cylinder fulfils the following expression (a) 0.3 × V1 × P0 / PP − P0 = < V2 < 0.8 × V1 × P0 / PP − P0 where V1 is a swept volume which is a cylinder volume while the piston moves from the bottom dead centre to the top dead centre, V2 is a compression volume which is a cylinder volume when the piston (2) is located at the top dead centre, and P0 is an air pressure, and ii) delivering a sealant into a vehicle tyre by means of a positive pressure built up in the compressor system.