Actuator

Abstract

Actuator (1) comprising a motor (2) and an actuator component (3) actuated by the motor (2), the actuator component comprising a movable gear component (4) with a first and a second stop component (5a, 5b), and a stop element (6) with an inner and an outer reference plane (6a, 6b) serving to stop the stop components (5a, 5b) of the gear component (4), wherein the stop element (6) and / or the first and / or the second stop component (5a, 5b) is / are made of a high-temperature plastic, characterized in that the high-temperature plastic of the stop element (6) and / or the first and the second stop component (5a, 5b) and / or the bayonet interface (7) has a modulus of elasticity of at least 17,500 N / mm², a tensile strength of at least 220 N / mm², an elongation at break of at least 2 N / mm², and an impact strength of at least 80 kJ / m2 and has an impact strength of at least 80 kJ / m2.

Description

[0001] The present invention relates to an actuator comprising a motor and an actuating component that can be actuated by the motor, the actuating component comprising a movable gear component with at least a first and a second stop component, and at least one stop element with an inner and an outer reference plane that serves to stop the stop component of the gear component. The invention further relates to the use of an actuator for adjusting the headlight range of a headlight.

[0002] The increasing demand for greater ease of use and enhanced safety is driving the development of ever more intelligent and therefore more complex systems. In automobiles, these systems include, for example, air conditioning, braking and locking systems, and headlight systems. Reliable actuators are required to perform the functions of these systems. Over time, the demands placed on actuators have increased significantly. Their functionalities are becoming more complex, the requirements for their reliability are rising, and their functionality must be guaranteed over an ever-longer service life. These actuators are typically high-performance designs adapted to a specific application, i.e., specific systems. Intelligent actuators integrate electromechanical and electronic components.

[0003] Typical applications for such actuators in motor vehicles include locking / unlocking and remote operation of fuel filler caps, tailgates, storage compartments, or headlight range adjustment. Safe driving in the dark is only possible with headlights whose tilt angle is always correctly adjusted. This is the only way to optimally illuminate the road without dazzling oncoming traffic. With the manual headlight range adjustment common in modern vehicles, the driver can adjust the headlight tilt to the vehicle's load using a switch on the dashboard. Modern headlight range control systems automatically adjust the headlight tilt angle to that of the vehicle body without any driver intervention. Two systems are often distinguished: static headlight range control corrects changes in tilt due to the vehicle's load.Furthermore, the dynamic headlight range control also reacts to changes in inclination due to braking and acceleration processes of the vehicle.

[0004] Systems with special headlight range control light output modules, such as AFS systems (AFS = adaptive frontlighting system), represent a lighting technology innovation in which, in addition to aligning the light with the road course, the situation-adapted light distribution for city, country and motorway driving can be adjusted.

[0005] The actuators required for this process execute the commands calculated by a control unit. This means that the actuators convert electrical signals from the control unit into physical control variables.

[0006] Future light-based driver assistance systems (LBAS) will require high positioning accuracy of the lighting function across the entire temperature range. Current actuators are made of a thermoplastic material, such as PBT. This means that a large proportion of the components of such actuators are made of thermoplastic material like PBT. However, actuators are exposed to extreme temperature conditions in operation, for example, in a motor vehicle. Temperature fluctuations ranging from -40°C to over 120°C are possible in a vehicle headlight. Furthermore, high heat resistance requirements, such as 4 hours at 120°C, are placed on the headlights and thus on the actuators connected to them. These temperature fluctuations and high heat resistance requirements lead to different settling behaviors of the components of a system, such as a headlight system.For a headlight range control actuator in a headlight system, this means that poor temperature stability of the actuator's thermoplastic material, for example, caused by a high coefficient of thermal expansion, can lead to the loss of reference planes for safe and glare-free operation. Since misalignment of a headlight during driving must be avoided at all costs due to the risk of dazzling other road users, the actuators are rereferenced every time they are put into operation. This ensures the precise positioning of the actuator, and thus its adjustment component, within the headlight, guaranteeing the required glare-free operation for the road.Depending on its installation position in the headlight, a headlight range control actuator, specifically a part of its actuating component, can strike different stop components, such as a housing cover, to perform a referencing operation. After the referencing operation begins, the actuating component moves the actuator forcefully to the relevant stop component with a significant number of steps.

[0007] A disadvantage of currently known actuators is that the plastic components involved do not meet the high temperature and accuracy requirements. Plastic deformation leads to a loss of accuracy in the actuator.

[0008] The object of the present invention is therefore to create an actuator in which the disadvantages described above can be avoided. In particular, an actuator is to be created in which the position of the stop component for carrying out a referencing process remains stable even at high temperatures.

[0009] This problem is solved according to the invention by an actuator having the features according to independent claim 1 and by the use of an actuator according to claim 11. Further features and details of the invention will become apparent from the dependent claims, the drawing, and the description. Features and details described in connection with the actuator naturally also apply in connection with the use of such an actuator, and vice versa, so that the disclosure of the individual aspects of the invention always refers, or can refer, to each other.

[0010] According to a first aspect of the invention, the problem is solved by an actuator comprising a motor and an actuator component actuated by the motor, which has a movable gear component with a first and a second stop component, and a stop element with an inner and an outer reference plane that serve to stop the stop component of the gear component, wherein the stop element and / or the first and / or the second stop component are made of a high-temperature plastic. Because the stop element and / or the first and / or the second stop component are made of a high-temperature plastic, the actuator exhibits very high temperature stability. The use of a high-temperature plastic for the stop element and / or the first and / or the second stop component of the actuator results in low thermal expansion and high strength.This ensures a minimization of the actuator's "temperature behavior," meaning minimal settling, particularly of the stop element. The stop element and / or the first and / or second stop component, both made of high-temperature plastic, are stable, especially temperature-stable, and can therefore reliably perform referencing and positioning operations of the actuator, particularly the actuator's control component, even under high temperature stress. In other words, the use of a high-temperature plastic for the stop element and / or the first and / or second stop component of the actuator minimizes the "thermal breathing" of the control component and / or thermally stabilizes the stop element during the referencing process.

[0011] The movable gear component of the actuator can be designed in various ways. In particular, the movable gear component depends on the type of motor of the actuator. For example, the gear component can consist of a plurality of gears and a movable plunger. According to a preferred embodiment of the invention, the actuator can be provided with a linearly guided actuating rod as the movable gear component. The actuating rod converts a movement of the motor into a linear actuating movement. To perform a referencing operation, the first or second stop component repeatedly strikes the stop element, which has an inner and an outer reference plane. That is, the stop element, or rather the reference planes of the stop element, serve as a reference for all subsequent actions of the actuator.If a defined number of steps in the opposite direction is specified, the geometric position of a corresponding component of the actuator, or the position of a system coupled to the actuator, such as a headlight, can be determined by counting the steps. The linearly guided actuating rod can be guided through an opening in a housing part, in particular an opening in a housing cover, of the actuator in order to determine the geometric position of a component of the actuator, for example, a ball joint of the actuator.

[0012] According to a particularly preferred embodiment of the invention, the actuator can be configured such that the stop element is a housing part of the actuator, in particular a housing cover of the actuator; that the first stop component is a stop element arranged radially on the movable gear component, wherein the gear component is guided in the housing part; and / or that the second stop component is a ball head of the gear component. Preferably, the gear component is an actuating rod. The gear component or the actuating rod is preferably guided through an opening in the housing part, in particular in the housing cover.The stop element is arranged radially on the transmission component, particularly on the actuating rod, such that during linear movement of the transmission component or the actuating rod, the stop element abuts the actuator housing part, specifically the outer reference plane of the housing part, when the transmission component or the actuating rod reaches a specific position relative to the actuator housing part. This means that the actuator's referencing process can be performed by the stop element, arranged radially on the stop element, striking the housing part. The actuator housing part, particularly the housing cover, therefore has an outer reference plane that serves as the abutment for the stop element of the transmission component, particularly the actuating rod. The stop element can be a disc, a cross, a projection, a pin, etc.

[0013] Alternatively or additionally to the previously described further development of the actuator, the actuator according to the invention can be provided with a ball head as the second stop component. The gear component, in particular the actuating rod, is guided through the housing part, in particular a housing cover, of the actuator, so that the ball head, which is arranged at the end of the gear component, in particular the actuating rod, can abut the housing part, in particular the housing cover, of the actuator. In this embodiment, the other side of the housing part, in particular the housing cover, serves as an inner reference plane for the stop of the ball head. This means that the ball head forms a second stop element for the stop at the inner reference plane. The ball head is made of a high-temperature plastic, so that it does not deform plastically due to temperature when it abuts the housing part.

[0014] According to another preferred embodiment of the invention, the actuator may be provided with a bayonet interface for coupling the actuator to a component to be actuated by the actuator component, particularly on a housing part of the actuator. The bayonet interface is made of a high-temperature plastic. In this way, the actuator can be coupled to a corresponding system, for example, a headlight housing, via the bayonet interface. Preferably, an O-ring serves as a locking mechanism, which is pre-tensioned by approximately 200 Newtons between the actuator, particularly the housing part (e.g., the housing cover), and the bayonet receptacle during the bayonet insertion process. Because the bayonet interface is made of a high-temperature plastic, it remains stable even at high temperatures and deforms only very slightly, if at all.Because the bayonet interface is also made of a high-temperature plastic, the thermal settling behavior of the bayonet interface is minimized.

[0015] An actuator designed as described above meets very high accuracy and temperature requirements. Because various actuator components, such as the stop element (which can be part of the housing), the bayonet interface for attaching the actuator to a system, and the ball head, are made of a high-temperature plastic, the overall temperature stability of the actuator is increased. Furthermore, the referencing position, i.e., the reference plane, is stabilized in such an actuator.

[0016] A particularly preferred actuator is one in which the motor is a stepper motor having at least one stator and a rotatable rotor, and which is coupled to the movable transmission component, in particular the actuating rod, such that the transmission component, in particular the actuating rod, can be moved linearly by a rotational movement of the rotor. The motor, which can also be called a stepper motor, is particularly preferably equipped with two stator windings that can be cyclically energized by an electrical driver. This creates a stepwise rotating magnetic field, which the rotor follows incrementally. The movable transmission component, in particular the movable actuating rod, converts the rotational movement of the rotor into a linear actuating movement.To prevent misalignment of the system coupled to the actuator, particularly a headlight, the stepper motor is rereferenced each time the system, especially the vehicle, is started. This ensures precise positioning of the actuator or the control component within the connected system. In the case of a headlight, this referencing ensures the exact positioning of the actuator or control component within the headlight and guarantees the required glare-free illumination for the road.

[0017] According to a particularly preferred embodiment of the invention, the actuator may be made of a highly crystalline, thermoplastic material with good mechanical, thermal, and electrical properties. Furthermore, it is preferred that such a high-temperature plastic exhibits excellent chemical resistance. For example, polyvinylidene fluoride, polytetrafluoroethylene, or polyetheretherketone may be used as such a highly crystalline, thermoplastic material. Such high-temperature plastics are also characterized by good hydrolysis resistance, high corrosion resistance, and good weather resistance. Furthermore, such high-temperature plastics are practically non-wettable by liquids and non-flammable, and serve as electrical insulators across a very wide temperature range.The high-temperature plastic of the stop element, in particular the housing cover, the ball head and / or the bayonet interface, is advantageously highly heat-resistant, stiff and strong and exhibits high chemical resistance.

[0018] According to a particularly preferred further development of the invention, and especially with regard to industrialization (high production volumes, low costs), the actuator can be provided with a high-temperature plastic material for the stop element and / or the bayonet interface and / or the first and second stop components and / or a further component of the actuator, each having a modulus of elasticity of at least 17500 N / mm². 2 , a breaking strength of at least 220 N / mm 2 , an elongation at break of at least 2 N / mm 2 , an impact strength of at least 80 kJ / m 2 and an impact strength of at least 80 kJ / m 2A high-temperature plastic with such mechanical properties increases the stability of the actuator, especially the adjusting component, and leads to a stabilization of the reference plane or referencing position. If the actuator is responsible for the range control of a headlight system, the actuator, especially the ball joint as a coupling element to the headlight module, has only a minor influence on the position of the cut-off line.

[0019] A preferred actuator is one in which the high-temperature plastic of the at least one stop element and / or the bayonet interface and / or the first and second stop components and / or a further component of the actuator has a melting point of at least 325°C and a coefficient of longitudinal expansion of less than 0.15 × 10 –4 / K at a temperature between 23°C and 55°C and a transverse coefficient of thermal expansion of less than 0.4 × 10 –4 / K at a temperature between 23°C and 55°C. A high-temperature plastic with such thermal properties is particularly well-suited as a material for the stop element and / or the bayonet interface and / or the stop component, such as the stop element and the ball head of the actuator. Using such a high-temperature plastic minimizes the temperature influence on the actuator and, at the same time, minimizes the actuator's temperature influence on the position of the light-dark boundary in an actuator designed for adjusting the lens's focal length.

[0020] In general, the use of such high-temperature plastics in actuators or for the individual components of actuators has the following effects: 1. Low thermal expansion and high strength of the actuator components, and thus a minimization of the actuator's "temperature behavior", especially the actuator component. 2. A stable, especially temperature-stable, housing geometry of the actuator to ensure internal referencing and positioning processes.

[0021] For example, the thermal settling behavior is minimized by bayonet mounting of the actuator. Furthermore, the "thermal breathing" of the actuator, especially of the actuator component, is minimized. Additionally, the use of such high-temperature plastics can provide thermal stabilization of the stop element or the reference planes of at least one stop element for the referencing process.

[0022] According to a further preferred embodiment of the invention, the actuator can be designed so that the high-temperature plastic of the stop element and / or the bayonet interface and / or the first and second stop components and / or other components of the actuator is dimensionally stable at temperatures above 250°C and remains dimensionally stable long-term at temperatures above 150°C. This ensures that the actuator's full functionality is maintained even over extended periods and under high temperature stress. An actuator with such properties ensures high thermal stability during operation. In particular, the use of such high-temperature plastics on the key components of the actuator and the stop element, especially the reference planes, guarantees high thermal stability.

[0023] According to a particularly preferred embodiment of the invention, the actuator is designed for adjusting the beam range of a headlight, especially a headlight for a motor vehicle. The use of an actuator, as described above, for beam range control of a headlight, particularly a motor vehicle headlight, minimizes the influence of the actuator's temperature on the position of the headlight's cut-off line. Such actuators enable high positioning accuracy of the light function across the entire temperature range of the headlight. The use of such an actuator for beam range control of a bi-xenon or AFS headlight system has proven particularly preferred, since temperature dependencies of the headlight components, especially the actuators, are particularly pronounced here due to the vertical movement of the cut-off line.An actuator designed in this way ensures the precise positioning of the actuator, or rather its actuating component, within the headlight system and guarantees the required glare-free illumination for the road. Temperature fluctuations within the headlight, ranging from -40°C to 120°C, and the high heat resistance requirements for the main headlight components lead to settling behavior in all components of the headlight system, including the actuator. Due to the very high temperature stability of the stop element, particularly the housing cover, or the ball joint or stop element of the actuator, the reference plane for safe and glare-free operation of the headlight system is maintained. Furthermore, the use of such an actuator prevents settling effects with significant impacts on the light pattern projected onto a 10-meter wall.The bayonet interface of the actuator does not experience any thermal deformation due to the high-temperature plastic, even though the bayonet interface, in particular the bayonet hooks of the bayonet interface, are subjected to a high preload.

[0024] Further advantages, features, and details of the invention will become apparent from the following description, in which an embodiment of the invention is described in detail with reference to the drawing. The features mentioned in the claims and in the description can each be essential to the invention individually or in any combination. The drawing schematically shows:

[0025] Fig. 1 an actuator in an exploded view, which is designed according to the design principle according to the invention.

[0026] Fig. Figure 1 schematically shows an exploded view of a possible design variant of the actuator. 1, which is designed according to the inventive design principle. The actuator 1 has an engine 2 , which is designed in particular as a stepper motor, and one of the motor 2 actuated actuator component 3 up. The actuator component 3 features a movable transmission component 4 , here is an adjusting rod, with a first and a second stop component 5a , 5b The stop element can be used as a stop component. 5a or one on the transmission component 4 arranged ball head 5b serve. The actuator 1 features a stop element 6 up, with an inner 6a and an outer reference plane 6b , which are used to stop the stop components 5a , 5b the transmission component 4 serve. In this version of the actuator. 1forms a housing part, here the housing cover, of the actuator. 1 the stop element 6 The motor designed as a stepper motor. 2 It preferably has two stator windings that can be cyclically energized by an electric driver. The cyclic energizing creates a stepwise rotating magnetic field to which the rotor is subjected. 2b of the engine 2 This follows step by step. The rotational movement of the rotor. 2b This results in a linear positioning movement of the adjusting rod. 4 To maintain the function of a system, such as a headlight, the motor is 2 It is re-referenced every time it is started up. For example, to prevent the headlight from being misaligned while driving, which could cause glare, the motor 2The headlight range control actuator is rereferenced every time the vehicle is started. This allows for precise positioning of the actuator. 1 or the actuator component 3 The headlight is secured and the required glare-free condition for the roadway is ensured.

[0027] The in Fig. 1 actuator preferably designed as a headlight range control actuator 1 Depending on the installation position in the headlight, it can be located on the inner reference plane. 6a of the stop element 6 , through the ball joint 5b , as well as at the outer reference plane 6b of the stop element, through the stop element 5a , reference. After the referencing process starts, the stepper motor moves 2 and thus the actuator component 3 with a majority of steps the corresponding stop element 6 hard. In Fig.1 serves in particular the radially on the adjusting rod 4 arranged stop element 5a as a stop component for stopping against the housing part designed as a housing cover 6 of the actuator 1 That is, the adjusting rod 4 is in the case lid 6 guided and the stop element 5a on the adjusting rod 4 After executing a predetermined number of referencing steps, it hits the housing cover hard. 6 on. The inner stop plane 6a in the case lid 6 This establishes the reference level for all further actions of the engine. 2 , in particular of the stepper motor. If a defined number of steps is specified in the opposite direction, the geometric position of the ball head can be determined by counting the steps. 5b or to deduce the position of the coupled headlight system, for example a light module.

[0028] The actuator 1 is via a bayonet interface 7 coupled to the headlight system, in particular the headlight housing. An O-ring serves as a locking mechanism, which is connected between the housing cover via the bayonet fitting process. 6 and the bayonet interface 7 or the bayonet mount of the bayonet interface 7 is pre-tensioned with approximately 200 N.

[0029] The stop element, that is, the housing part or the housing cover 6 , as well as the ball head 5b , as well as the bayonet interface 7 of the actuator 1 They are made of a high-temperature plastic. This high-temperature plastic is characterized by high performance at high operating temperatures. Actuator components 1Made from a high-temperature plastic, they are heat-resistant, rigid, and strong, and exhibit good chemical resistance. The major advantage of manufacturing an actuator from this material is... 1 or the components of the actuator 1 The advantage of using a high-temperature plastic lies in the fact that these parts can be manufactured very easily using a casting process, especially an injection molding process, and are particularly easy to reproduce. The major advantage of manufacturing an actuator from this material is that... 1 or the components of the actuator 1 The advantage of using a high-temperature plastic is that it can be industrially produced, especially in large quantities and at relatively low cost.

[0030] An actuator trained in this way 1It is characterized in particular by the low coefficient of thermal expansion and the high material hardness of the high-temperature plastic. That is to say, the low coefficient of thermal expansion and the high material hardness of the housing part. 6 , of the ball head 5b , of the stop element 5a and the bayonet interface 7 ensure that the position of the inner and outer reference planes 6a , 6b of the housing part serving as a stop element 6 remains stable under prolonged high temperature stress and that the reference planes 6a , 6b The hard referencing stop prevents plastic deformation at high temperatures. It features a bayonet interface made of high-temperature plastic. 7 The bayonet hooks remain stable even at high temperatures. 7a the bayonet interface 7They deform only very slightly, if at all. Furthermore, such a designed actuator ensures that the ball head 5b As a coupling element to the headlight module, for example to the light module, it has only a minor influence on the temperature-dependent position of the headlight module's light-dark boundary. The targeted use of high-temperature plastics for the actuator components, especially the headlight actuators, stabilizes the actuator. 1 thermally and minimizes the temperature-dependent influence on the light-dark boundary. Reference symbol list 1 actuator 2 Engine 2a Stator 2b Rotor 3 actuator components 4 Gearbox component 5a Stop component / stop element 5b Stop component / ball head 6 Stop element with an inner and an outer reference plane / housing part 6a inner reference plane 6b outer reference plane 7 Bayonet interface 7a Bayonet hook

Claims

[1] Actuator ( 1 ), having a motor ( 2 ) and one of the engine ( 2 ) actuating actuator component ( 3 ), which is a movable transmission component ( 4 ) with a first and a second attack component ( 5a , 5b ) has, and a stop element ( 6 ) with an inner and an outer reference plane ( 6a , 6b ), which are used to stop the stop components ( 5a , 5b ) the transmission component ( 4 ) serve, characterized by , that the stop element ( 6 ) and / or the first and / or the second attack component ( 5a , 5b ) is / are made of a high-temperature plastic. [2] Actuator ( 1 ) according to claim 1, characterized in that the movable transmission component ( 4 ) the actuator component ( 3 ) one driven by the engine ( 2 ) linearly guided adjusting rod is. [3] Actuator ( 1 ) according to claim 1 or 2, characterized in that the stop element is a housing part ( 6 ) of the actuator ( 1 ), in particular a housing cover, is that the first stop component is a stop element arranged radially on the transmission component ( 5a ) is, where the transmission component ( 4 ) in the housing part ( 6 ) is guided, and / or that the second stop component is a ball head ( 5b ) the transmission component ( 4 ) is. [4] Actuator ( 1 ) according to one of claims 1 to 3, characterized in that the housing part ( 6 ) of the actuator ( 1 ) a bayonet interface ( 7 ) for coupling the actuator ( 1 ) with a component through the actuator ( 3 ) to be provided system or system component is arranged, wherein the bayonet interface ( 7) is made of a high-temperature plastic. [5] Actuator ( 1 ) according to one of claims 1 to 4, characterized in that the motor ( 2 ) is a stepper motor that has at least one stator ( 2a ) and a rotating rotor ( 2b ) exhibits and is thus connected to the transmission component ( 4 ) the actuator component ( 3 ) is coupled by a rotational movement of the rotor ( 2b ) the transmission component ( 4 ) is linearly movable. [6] Actuator ( 1 ) according to one of claims 1 to 5, characterized in that the high-temperature plastic of the stop element ( 6 ) and / or the first and second attack components ( 5a , 5b ) and / or the bayonet interface ( 7 ) is highly heat-resistant, stiff and strong and has high chemical resistance. [7] Actuator ( 1) according to one of claims 1 to 6, characterized in that the high-temperature plastic of the stop element ( 6 ) and / or the first and second attack components ( 5a , 5b ) and / or the bayonet interface ( 7 ) has a modulus of elasticity of at least 17500 N / mm2, a tensile strength of at least 220 N / mm2, an elongation at break of at least 2 N / mm2, an impact strength of at least 80 kJ / m2 and a notched impact strength of at least 80 kJ / m2. [8] Actuator ( 1 ) according to one of claims 1 to 7, characterized in that the high-temperature plastic of the stop element ( 6 ) and / or the first and second attack components ( 5a , 5b ) and / or the bayonet interface ( 7) has a melting point of at least 325°C and a coefficient of longitudinal expansion of less than 0.15 times 10–4 / K at a temperature between 23°C and 55°C and a coefficient of transverse expansion of less than 0.4 times 10–4 / K at a temperature between 23°C and 55°C. [9] Actuator ( 1 ) according to one of claims 1 to 8, characterized in that the high-temperature plastic of the stop element ( 6 ) and / or the first and second attack components ( 5a , 5b ) and / or the bayonet interface ( 7 ) is dimensionally stable in the short term at temperatures above 250°C and dimensionally stable in the long term at temperatures above 150°. [10] Actuator ( 1 ) according to one of claims 1 to 9, characterized in that the actuator ( 1 ) is designed to adjust the beam range of a headlight. [11] Use of an actuator ( 1) according to at least one of claims 1 to 10 for the range control of a headlight, in particular a headlight of a motor vehicle.