Door handle for a motor vehicle

Abstract

Door handle (1) for a vehicle door (2) of a motor vehicle, wherein a heater (3) is integrated in the door handle (1) and is in thermally conductive connection with an outer side (4) of the door handle (1), wherein the heater (3) comprises an electrically conductive polymer material (7).

Description

[0001] The present invention relates generally to exterior door handles for vehicle doors and, more particularly, to an extendable exterior door handle in which a heating mechanism is integrated into the door handle.

[0002] Various automotive designs include exterior door handles that extend for use. These door handles are flush-mounted and generally inaccessible when the occupant is inside the vehicle or when the vehicle is parked and not in use. When the occupant approaches the vehicle from outside, the door handles extend, allowing the occupant to grasp the extendable handle to operate the door handle and enter the vehicle's passenger compartment.

[0003] It has been found that such door handles are regularly at risk of icing up, so that extending the door handles is no longer possible due to ice on the vehicle's exterior surface.

[0004] Based on this, the object of the present invention is to at least partially solve the problems described with reference to the prior art. This object is achieved by the invention according to the features of the independent patent claims. Further advantageous embodiments are specified in the dependent claims as well as in the description and, in particular, in the description of the figures. It should be noted that the person skilled in the art can combine the individual features in a technologically expedient manner and thus arrive at further embodiments of the invention.

[0005] Described here is a door handle for a vehicle door of a motor vehicle, wherein a heater is integrated in the door handle and is in thermally conductive connection with an outer side of the door handle, wherein the heater comprises an electrically conductive polymer material.

[0006] Particularly advantageously, the door handle has an outer shell which forms the outside of the door handle and an interior space opposite the outside, wherein the heater forms an insert in the interior space of the outer shell.

[0007] The outer shell is preferably part of a housing of the door handle, wherein the housing is formed from the outer shell and an inner shell.

[0008] The door handle is in particular part of a door opening mechanism of a vehicle door.

[0009] The door release mechanism is used to selectively release a vehicle door from a closed position to an open position. A door handle is connected to the door release mechanism and is disposed on the vehicle door. The door handle can be moved between a flush position and an extended position. In the flush position, an outer side of the door handle is flush with a portion of an exterior surface of the vehicle door immediately surrounding the door handle, allowing access to only the outer side of the door handle. In the extended position, the outer side of the door handle is moved away from the exterior surface of the vehicle door, allowing access to a rear surface of the door handle.

[0010] The door handle is preferably not operable by an operator in the flush position. In the extended position, the door handle is operable by an operator. Preferably, the operator can grasp the door handle in the extended position to pull on the door handle and thereby open the vehicle door. Preferably, the operator can then access a rear surface of the door handle, which is opposite the exterior side.

[0011] According to a further aspect of the present invention, a vehicle door comprises an outer door panel having a handle recess. The outer door panel forms the outer surface of the vehicle door. A handle recess is located in the outer door panel or outer surface, in which the (extendable) door handle is arranged.

[0012] The heater is preferably in thermal communication with the outer side of the door handle and the outer surface of the vehicle door immediately surrounding the door handle. In particular, the heater can be used to heat a peripheral contour of the outer side of the door handle in order to melt a layer of ice on the outer side. Such a layer of ice can block the door handle, making it impossible to move from the flush position to the extended position. This effect can be prevented or reversed by using the heater. The heater is preferably configured so that heat for melting a layer of ice is generated primarily in the region of the peripheral contour of the outer surface of the door handle.

[0013] The heater comprises an electrically conductive polymer material. The electrically conductive polymer material forms a heating resistor in which electrical current is converted into heat. The electrically conductive polymer material is preferably arranged in an interior space of the door handle or within a housing of the door handle. The electrically conductive polymer material preferably completely fills the interior space of the outer shell. The electrically conductive polymer material preferably covers, in particular, a base of the interior space of the outer shell opposite the outer side. The electrically conductive polymer material preferably rests against a housing material of the door handle or the outer shell in the interior space.

[0014] It is also advantageous if the electrically conductive polymer material is cast, inserted, glued or injected into the outer shell.

[0015] The housing of the door handle, or its outer shell and inner shell, are preferably made of a plastic material. The electrically conductive polymer material is preferably also a plastic material. The electrical conductivity of the electrically conductive polymer material is ensured in particular by the structure of the polymer material and, if applicable, additives in the polymer material. The electrically conductive polymer material is preferably significantly softer than the material of the housing or the material of the outer shell.

[0016] By injecting and / or pouring the electrically conductive polymer material, a very strong, heat-conducting bond between the electrically conductive polymer material and the outer shell can be achieved.

[0017] In some embodiments, the electrically conductive polymer material can also be embedded in the outer shell. Preferably, the embedded electrically conductive polymer material is subjected to a pressure that presses the embedded electrically conductive polymer material against the outer shell to ensure good heat transfer between the electrically conductive polymer material and the outer shell.

[0018] The electrically conductive polymer material can also be additionally glued into the outer shell. Preferably, an adhesive is used that ensures good thermal conductivity between the electrically conductive polymer material and the outer shell.

[0019] The thickness of the outer shell or the outer shell's housing material is preferably between 1 mm [millimeter] and 5 mm in the outer area. Heat generated in the electrically conductive polymer material thus preferably reaches the outside of the door handle quickly and with minimal loss, where it can melt any layer of ice.

[0020] It is particularly preferred if the heater is arranged in the door handle in such a way that in particular an edge surrounding the outside of the door handle can be heated with the heater.

[0021] The door handle is preferably designed such that, when flush with the outer surface of the door, it forms a flat surface. For this reason, the outer side of the door handle is essentially flat. For this reason, the outer side of the door handle has a circumferential edge that surrounds the (flat) outer side. The interior of the door handle or the interior of an outer shell of the door handle preferably has a circumferential corner region that is located opposite the circumferential edge on the other (inner) side of the housing material of the outer shell. This region is preferably also circumferential. This means that the corner region forms a closed contour.

[0022] Particularly preferably, the electrically conductive polymer material forms a ring section that fills this corner region. Particularly preferably, electrical conductor structures for supplying current to the electrically conductive polymer material are designed such that heat is generated particularly in this corner region.

[0023] The door handle preferably has regions that are moved more than other regions when the door handle is moved from the flush position to the extended position. For example, the door handle or the outer side of the door handle is tilted relative to the outer surface of the vehicle door when it is moved from the flush position to the extended position. For this purpose, the door handle is particularly preferably moved about a pivot point. The heater or, in particular, the electrically conductive polymer material is particularly preferably arranged in the door handle in such a way that greater heating occurs in regions that are moved further when moving from the flush position to the extended position or that are further away from a pivot point of the door handle.

[0024] In further embodiments, the door handle is moved parallel or at least partially parallel from the flush position to the extended position. The door handle then preferably has a drive comprising two or more drive motors that push the door handle out of the door in parallel, so that the outer side of the door handle is guided out of the outer surface of the vehicle door.

[0025] The electrically conductive polymer material particularly preferably has PTC properties.

[0026] The electrically conductive polymer material can, for example, be an intrinsically conductive polymer (or an intrinsically conductive plastic). In other words, this means, in particular, that the electrically conductive polymer material is one that is itself electrically conductive. Alternatively or additionally, it can be provided that the electrically conductive polymer material is electrically conductive due to at least one electrically conductive additive or filler, such as aluminum flakes or carbon black, which is contained or embedded in a (not necessarily itself conductive) polymer.

[0027] Preferably, at a switching temperature, a change in the structure of the polymer material occurs, which leads to the deactivation of electrically conductive paths in the polymer material.

[0028] If the resistance of a material increases with increasing temperature, it has a positive temperature coefficient. Materials with metal-like conductivity generally possess a positive temperature coefficient with respect to their electrical resistance (PTC properties or PTC resistance properties). With metal-like conductivity, the resistance increases almost linearly with increasing temperature. In contrast, electrically conductive polymer materials generally exhibit a strong increase in resistance within a very narrow temperature range. These polymer materials are generally abbreviated as PPTC. PPTC stands for Polymer Positive Temperature Coefficient.

[0029] In other words, the electrically conductive polymer material with PTC resistance properties can also be described as a so-called (polymer) PTC thermistor. A PTC thermistor, PTC resistor, or PTC thermistor is a temperature-dependent resistor that belongs specifically to the group of thermistors. One property it has is a positive temperature coefficient and conducts electrical current better at low temperatures than at high temperatures.

[0030] The electrically conductive polymer material with PTC effect is preferably designed such that it has a switching temperature between 10° Celsius and 40° Celsius. This allows temperatures of the door handle to be reached that are sufficient to melt a layer of ice, while simultaneously preventing excessive consumption of electrical energy by the heating in the door handle. Furthermore, the switching temperature is preferably selected such that the door handle cannot become too hot due to heating. In particular, the door handle should not become so hot due to heating that an operator finds it annoying / uncomfortable when grasping the door handle. For this reason, the switching temperature is preferably a maximum of 40°C or lower.

[0031] It is also advantageous if electrical conductor structures for applying electrical current to the electrically conductive polymer material are arranged between the outer side and the electrically conductive polymer material.

[0032] It is also advantageous if the electrical conductor structures comprise at least one first electrical conductor structure and at least one second electrical conductor structure, each having comb-like sections, wherein the comb-like sections of the first electrical conductor structure and the second electrical conductor structure interlock.

[0033] The electrical conductor structures are preferably metallic, and in particular metallic sheet metal elements, for example made of copper, silver, or aluminum, and / or coated with copper, silver, or aluminum. Two separate electrical conductor structures can apply a voltage to the electrically conductive polymer material. This allows an electrical current (heating current) to flow through the electrically conductive polymer material. This generates heat in the electrically conductive polymer material.

[0034] In principle, the distance between the at least two separate electrical conductive structures in the polymer material is a parameter with which the necessary electrical voltage to generate a desired heating current can be adjusted. The distance is preferably in a range between 1 mm (millimeter) and 10 mm (millimeter).

[0035] It is also advantageous if the at least two separate electrical conductive structures form comb structures that engage with each other at least in some areas.

[0036] Comb structures feature a small distance between at least two separate electrically conductive structures. Such comb structures are particularly suitable when a particularly uniform distribution of electrical current across the electrically conductive polymer material is desired. Furthermore, such comb structures can ensure that only relatively short paths of electrical current through the electrically conductive polymer material occur, thus keeping the operating voltage of the heater within a low range.

[0037] Particularly preferably, the electrically conductive polymer material covers the electrical conductor structures in the interior. The door handle is preferably manufactured such that the outer shell is first provided, and the electrical conductor structures are inserted into the outer shell. The electrical conductor structures are preferably subsequently covered with the electrically conductive polymer material, for example, by casting or injecting the electrically conductive polymer material into the outer shell. The electrically conductive polymer material preferably fixes the conductor structures in the outer shell.

[0038] Furthermore, it is advantageous if an outer shell, which forms the outside of the door handle, has a plug section oriented inwards, away from the outside, to which a power supply plug for supplying the heater with electrical current can be connected.

[0039] The plug section is preferably made of the (less soft) material of the outer shell and not of the electrically conductive polymer material.

[0040] Furthermore, it is advantageous if electrical conductor structures for applying electrical current to the electrically conductive polymer material of the heater form connecting pins which extend into the plug section in such a way that a power supply plug connected to the plug section is connected to the connecting pin.

[0041] Preferably, the plug section is designed such that a metal structure forming the electrical conductor structures can be inserted into the outer shell such that sections of the metal structure forming the connection pins are positioned in the plug section and can act there as connection pins for connecting to a supply plug.

[0042] Also to be described herein is a door opening mechanism for selectively releasing a vehicle door of a vehicle from a closed position comprising a door handle according to any one of the preceding claims, wherein the door opening mechanism has a drive with which the door handle can be moved back and forth between a flush position and an extended position, wherein in the flush position an outer side of the door handle is flush with a portion of an outer surface of the vehicle door which immediately surrounds the door handle and wherein in the extended position the outer side of the door handle is moved away from the outer surface of the vehicle door so that an operator can access a rear surface of the door handle.

[0043] The special advantages and design features described above in connection with the door handle also apply to the door opening mechanism described.

[0044] It is particularly advantageous if the door opening mechanism has a temperature sensor with which the temperature of the door handle can be monitored in order to detect any risk of the door handle becoming icy.

[0045] As a general rule, unnecessary heating of the door handle (when there is no layer of ice blocking its extension) should be avoided whenever possible. For this reason, it is advantageous to monitor the temperature. Blocking of the door handle by a layer of ice is only possible at low temperatures. The door opening mechanism is preferably configured so that the door handle is only heated when temperatures are such that a layer of ice on the door handle or door is possible.

[0046] It is also advantageous if the drive for moving the door handle from the flush position to the extended position is designed to mechanically test in a test operation whether the door handle is blocked.

[0047] In principle, it is possible that no layer of ice is present even at low temperatures (where the formation of layers of ice on the door or door handle is theoretically possible). Such situations can be reliably detected by operating a door handle drive in test mode to determine whether the door handle is blocked or not. During test mode, the drive can, for example, be operated with standard drive currents that are usually used to move the door handle. Preferably, it is detected based on parameters (e.g. based on electrical parameters of the drive) that the door handle is not moving. If the door handle is not moving, the heating can be started if necessary.

[0048] Most preferably, the heater is only activated when several conditions are met that together indicate that operating the heater can clear a potentially existing blockage in the door handle. For example, the heater is activated when, on the one hand, a temperature sensor detects low temperatures, indicating the possibility of a layer of ice, and, on the other hand, the test operation described has determined that the door handle is indeed blocked.

[0049] Furthermore, it is advantageous if the door opening mechanism has a control unit which is designed to detect a signal of an operator approaching the vehicle and, when an operator approaches, to carry out measures to detect possible icing of the door handle and, if necessary, to activate the heating.

[0050] It is usually the case that it takes some time for the heater to sufficiently dissolve or partially dissolve the ice layer so that the door handle can be extended. When an operator approaches the vehicle, they generally expect the door handles to be available for operation and to be in the extended position. Operation of the door handle heaters is particularly preferably initiated when there is a signal that an operator is approaching and, at the same time, other conditions exist, such as the low temperatures described and, if applicable, the detection of a blockage of the door handle by a test operation of the drive. If necessary, other conditions can be checked before the heater is activated. A control unit of the door opening mechanism is preferably designed to check such conditions and to activate the heater depending on these.

[0051] In further design variants, the control unit and / or the drive are designed in such a way that in the test operation it is possible to determine how thick a layer of ice can be based on at least one operating parameter of the drive and the heating is controlled depending on this.

[0052] The ice layer normally has a certain degree of flexibility. Testing may cause the ice layer to deform, which can be detected based on the drive's operating parameters. While this prevents the door handle from extending, it can be determined that the heating required to clear the blockage is reduced.

[0053] The invention and the technical context of the invention are explained in more detail below with reference to the figures. The figures show preferred embodiments to which the invention is not limited. It should be noted in particular that the figures, and in particular the proportions depicted in the figures, are only schematic. They show: Fig. 1: a retractable door handle in an extended position; Fig. 2: a retractable door handle in a retracted position; Fig. 3: an outer shell of a retractable door handle; Fig. 4: an exploded view of a retractable door handle; Fig. 5: an arrangement of electrical conductive structures for a retractable door handle; and Fig. 6: a schematic representation of a motor vehicle.

[0054] The Fig. 1 and the Fig. 2 show a retractable door handle 1. In Fig. 1, the retractable door handle 1 is shown in an extended position 18. In Fig. 2, the retractable door handle 1 is shown in a flush position 17. A section of the vehicle door 2 or the outer surface 19 of the vehicle door 2 in the immediate vicinity of the door handle 1 can be seen. If the door handle 1 is in the position shown in Fig. 2 is in the flush position 17, the outer side 4 of the door handle 1 is flush with the outer surface 19 of the vehicle door 2. The outer side 4 of the door handle 1 has a circumferential edge 28, which forms the transition from the outer side 4 of the door handle 1 to the outer surface 19 of the vehicle door 2. A layer of ice can then form on the outer surface 19 of the vehicle door 2, preventing the door handle 1 from being extended. In the extended position 18 according to Fig. 2, an operator can grasp the door handle 1 and, in particular, also exert force on the door handle 1 from a rear surface 20 of the door handle 1 in order to pull on the door.

[0055] Fig. 3 shows an outer shell 5 of the door handle 1 proposed here, which forms the outer side 4 of the door handle 1. The outer shell 5 has a (shell-shaped) interior 6 oriented away from the outer side 4. The heater 3 proposed here is arranged in the interior 6 and is made of an electrically conductive polymer material 7. A plug section 11 is also formed on the outer shell 5, which extends (starting from the interior 6) away from the outer side 4 inwardly and to which a power supply plug 12 can be connected.

[0056] Fig. 4 shows an exploded view of the door handle 1, whose outer shell 5 in Fig. 3. Also visible here is the outer shell 5 and an associated rear shell 25, which forms the rear surface 20 of the door handle 1 and which, together with the outer shell 5, forms a housing for the door handle 1. The heater 3 is arranged in the interior 6 of the outer shell 5 and between the outer shell 5 and the rear shell 25. The heater 3 comprises the described electrically conductive polymer material 7. The electrically conductive polymer material 7 is supplied with an electrical current via electrical conductor structures 8, 9. The electrical current is converted into heat in the electrically conductive polymer material 7 in order to heat the door handle 1. Preferably, there is a first electrical conductor structure 8 and a second electrical conductor structure 9, between which an electrical voltage can be applied in order to generate an electrical current through the electrically conductive polymer material 7.The electrical conductor structures 8, 9 are introduced into the interior 6 of the outer shell 5 between the outer shell 5 and the electrically conductive polymer material 7. In preferred embodiments, the electrically conductive polymer material 7 is cast or injected into the outer shell 5. Preferably, the electrical conductor structures 8, 9 are thus firmly fixed between the electrically conductive polymer material 7 and the outer shell 5.

[0057] On the outer shell 5 there is also (as per Fig. 3) the plug section 11 is shown. The plug section 11 is preferably designed such that electrical conductor structures 8, 9, which are inserted into the interior, can extend into the plug section 11 such that connection pins 13 formed therein are located in the plug section 11, so that a power supply plug 12 can be connected thereto. Preferably, the heater 3 or the electrically conductive polymer material 7 and particularly preferably also the rear shell 25 each have plug recesses 26 through which a supply plug 12 can be brought into engagement with the plug section 11. Also arranged on the door handle 1 and in particular on the rear shell 25 is a pivot point 27 or a drive point, about which the door handle 1 can be rotated and around which the door handle 1 is moved when it is moved from the flush position 17 to the extended position 18.The rotation of the door handle 1 around a pivot point 27 is only one variant for moving the door handle 1 or its outer side 4 out of the outer surface 19 of the vehicle door 2. In other design variants, a parallel displacement of the door handle 1 from the flush position 17 to the extended position 18 is also possible.

[0058] In Fig. 1 shows the described conductor structures 8, 9, with which the electrically conductive polymer material 7 of the heater 3 can be supplied with current. There is at least a first electrical conductor structure 8 and a second electrical conductor structure 9, each of which has interlocking comb-like sections 10, between which an electrical voltage can be applied. The electrically conductive polymer material 7 surrounds the electrical conductor structures 8, 9 such that an electrical current through the electrically conductive polymer material 7 occurs as a result of an electrical voltage between the electrical conductor structures 8, 9. Connecting pins 13 are provided on each of the electrical conductor structures 8, 9, which preferably extend into the plug section 11 in order to be able to be connected there to a power supply plug 12 for supplying the heater 3 with electrical current.

[0059] Fig.6 shows a vehicle 23 having at least one vehicle door 2 with a retractable door handle 1 as described. Shown here is the door handle 1 in the flush position 17, in which an outer surface 19 of the door is flush with an outer side 4 of the door handle 1. An example of icing 22 is shown, which in such a situation prevents the door handle 1 from being extended from the flush position 17 into the extended position 18. The door handle 1 is part of a door opening mechanism 14 with which an operator can open the vehicle door 2. The door opening mechanism 14 also includes a drive 16 (in particular an electric drive motor) with which the door handle 1 can be moved from the flush position 17 into the extended position 18, as well as a control unit 24 with which the drive 16 can be controlled.The drive 16 can preferably also be used to drive the door handle 1 for test purposes in order to detect resistance caused, for example, by icing 22. If such resistance is detected, the control unit 24 can preferably activate the heater 3 in the door handle 1 to remove the icing. Also shown is a temperature sensor 21, with which an ambient temperature and / or a temperature of the door handle 1 can be measured. The control unit 24 is preferably configured to check, based on the temperature, whether icing 22 of the door handle 1 is at all plausible and to initiate further steps to remove icing 22 only if icing 22 has been detected. List of reference symbols 1 door handle 2 vehicle doors 3 Heating 4 Outside 5 Outer shell 6 Interior 7 electrically conductive polymer material 8 first electrical conductor structure 9 second electrical conductor structure 10 Comb-like section 11 Plug section 12 power supply plugs 13 connection pin 14 Door opening mechanism 15 closed position 16 Drive 17 flush position 18 extended position 19 Exterior area 20 rear surface 21 Temperature sensor 22 Icing 23 vehicles 24 Control unit 25 inner shell 26 connector recess 27 Pivot point 28 surrounding edge

Claims

[1] Door handle (1) for a vehicle door (2) of a motor vehicle, wherein a heater (3) is integrated in the door handle (1) and is in thermally conductive connection with an outer side (4) of the door handle (1), wherein the heater (3) comprises an electrically conductive polymer material (7). [2] Door handle (1) according to claim 1, comprising an outer shell (5) which forms the outer side (4) of the door handle (1) and an interior space (6) opposite the outer side (4), wherein the heater (3) forms an insert in the interior space (6) of the outer shell (5). [3] Door handle (1) according to claim 2, wherein the electrically conductive polymer material (7) is cast, inserted, glued or injected into the outer shell (5). [4] Door handle (1) according to one of the preceding claims, wherein the heater (3) is arranged in the door handle (1) in such a way that in particular an edge (27) surrounding the outer side (4) of the door handle (1) can be heated with the heater. [5] Door handle (1) according to one of the preceding claims, wherein the electrically conductive polymer material (7) has PTC properties. [6] Door handle (1) according to one of the preceding claims, wherein electrical conductor structures (8, 9) for applying electrical current to the electrically conductive polymer material (7) are arranged between the outer side (4) and the electrically conductive polymer material (7). [7] Door handle (1) according to claim 6, wherein electrical conductor structures (8, 9) comprise at least a first electrical conductor structure (8) and at least one second electrical conductor structure (9), each having comb-like sections (10), wherein the comb-like sections (10) of the first electrical conductor structure (8) and the second electrical conductor structure (9) engage with one another. [8] Door handle (1) according to one of the preceding claims, wherein an outer shell (5) forming the outer side (4) of the door handle (1) has a plug section (11) directed inwards away from the outer side (4), to which a power supply plug (12) for supplying the heater (3) with electrical current can be connected. [9] Door handle according to claim 7, wherein electrical conductor structures (8, 9) for supplying the electrically conductive polymer material (7) of the heater (3) with electrical current form connecting pins (13) which extend into the plug section (11) in such a way that a power supply plug (12) connected to the plug section (11) is connected to the connecting pin (13). [10] A door opening mechanism (14) for selectively releasing a vehicle door (2) of a vehicle (23) from a closed position (15), comprising a door handle (1) according to any one of the preceding claims, wherein the door opening mechanism (14) comprises a drive (16) with which the door handle (1) can be moved back and forth between a flush position (17) and an extended position (18), wherein in the flush position (17) an outer side (4) of the door handle (1) is flush with a portion of an outer surface (19) of the vehicle door (2) that immediately surrounds the door handle (1), and wherein in the extended position (18) the outer side (4) of the door handle (1) is moved away from the outer surface (19) of the vehicle door (2) so that an operator can access a rear surface (20) of the door handle (1). [11] Door opening mechanism (14) according to claim 10, comprising a temperature sensor (21) with which a temperature of the door handle (1) can be monitored in order to detect a risk of icing of the door handle (1). [12] Door opening mechanism (14) according to one of claims 10 or 11, wherein the drive (16) for moving the door handle (1) from the flush position (17) into the extended position (18) is designed to mechanically test in a test operation whether there is a blockage of the door handle (1). [13] Door opening mechanism (14) according to one of claims 10 to 12, comprising a control unit (24) which is configured to detect a signal of an approach of an operator to the vehicle (23) and, when an operator approaches, to carry out measures to detect a possible icing of the door handle (1) and, if necessary, to activate the heating (3).

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