Belt winder unit and vehicle with such a belt winder unit

Abstract

The invention relates to a tape winder unit with a housing (10), a tape coil (20) rotatably supported in the housing (10), a latching unit for latching the tape coil on the housing, wherein the latching unit has an actuator unit (40) with an electromagnet (42) and a control device (50) for operating the electromagnet (42), which has a power supply input (55), a power supply output (56) connected to the electromagnet (42), and at least one signal input (57) for receiving a control signal and / or a sensor unit (52) for generating a control signal, wherein the control device (50) has at least one first active switching state and one passive switching state, wherein in the first active switching state a current flows between the power supply output (56) and the electromagnet (42) with a current intensity which is greater than the current in the passive switching state, wherein the control device (50) has at least one DC-DC converter (60) as a constant current source between the power supply input and the power supply output, such that the current intensity in the first active switching state has a defined first value (I1) which is independent of the voltage applied at the power supply input.

Description

[0001] manual The present invention relates to a belt winder unit and a vehicle equipped with such a belt winder unit.

[0002] Every modern passenger car, as well as most trucks, buses, etc., has a seatbelt system. This seatbelt system always has a belt reel unit, which in turn has a housing and a belt coil rotatably supported within the housing. A portion of the seatbelt is wound around this belt coil, and the user can unwind it from the coil by overcoming the force of a return spring acting between the belt coil and the housing. A locking device is also provided, having a released state where the belt coil is not locked to the housing and a locked state where the belt coil is locked to the housing. This locking device typically has two independent sensors: a belt-sensitive sensor that detects the rotation of the belt coil, and a vehicle-sensitive sensor that detects the vehicle position and / or vehicle acceleration (especially negative vehicle acceleration, i.e., deceleration). Under normal driving conditions, i.e., when the belt is not pulled out too quickly, and the vehicle is not in an abnormal position or accelerating abnormally, the locking device is in the unlocked state, allowing the user to pull out the belt and move relatively freely. However, if the belt is pulled too fast and / or, for example, the vehicle decelerates too quickly, the locking device is in the locked state.

[0003] Currently, most locking devices are entirely mechanically designed, meaning the entire locking device (including sensors) is rigidly attached to the housing of the belt winder unit. However, this rigid connection between the entire locking device and the housing has drawbacks, especially when the belt winder unit is fixed to the vehicle seat, particularly its backrest, because in this case, the position of the belt winder, and therefore the position of the vehicle's sensitive sensors, may change relative to the vehicle.

[0004] Therefore, belt winder units that are fully or partially electrically operated are also known, whose locking devices have a locking mechanism with an electromagnet connected to the housing and a control device for controlling the electromagnet. This electromagnet is part of an electrically operable actuator unit, in such a way that the state of the actuator unit (particularly de-energized or energized) determines the state of the locking unit (rotatable belt coil or locked belt coil). Typically, the locking unit still has a reset element (usually in the form of a spring) opposite to the electromagnet. This reset element can be part of the actuator unit. For safety reasons (fail-safe), the de-energized state is usually the locked state, and the energized state is the unlocked state. Therefore, the control device of the actuator unit, having a power input connected to the vehicle's power supply and a power output connected to the electromagnet, has a passive switching state where the power supply from the power input to the power output is interrupted, and an active switching state where the power input is connected to the power output so that current flows through the electromagnet. In this case, the control device is typically only electrically coupled to the locking device and can be located anywhere in the vehicle, particularly preventing it from moving with the backrest. For example, GB 23 98 824 B describes a general-purpose belt winder unit with such a locking unit and control device. This electrically operated belt winder unit has further advantages because it provides more possibilities for controlling the state (locked / unlocked) of the belt winder unit.

[0005] Of course, a drawback of this universal belt winder unit is that it increases the vehicle's power consumption compared to a purely mechanically operating belt winder unit. This is particularly relevant because it is often preferred, or even mandated, that the belt winder unit be in a de-energized state, i.e., locked when no current flows through the electromagnet. This means that during normal driving, when the belt winder unit is naturally unlocked, current flows through the electromagnet, creating a permanent additional power consumption during vehicle operation. This is undesirable for ordinary internal combustion engine vehicles, as the alternator is permanently subjected to a higher load, which itself increases the vehicle's total energy consumption. This problem is even more severe for vehicles that are fully or partially electric, as the increased power consumption negatively impacts the electric driving range.

[0006] Therefore, the present invention aims to improve the general-purpose tape winder unit by reducing its power consumption.

[0007] This objective is achieved by the belt winder unit of the present invention.

[0008] Given a specific geometry, the force exerted by an electromagnet on a magnetic element depends entirely on the intensity of the current flowing through the electromagnet (i.e., its windings). The windings of such an electromagnet are essentially ohmic resistors, so the current intensity depends linearly on the applied voltage. When current flows through the electromagnet, in order to maintain the state of the locking unit, the electromagnet must exert a minimum force on the element it applies to, which in turn means that a current with a minimum intensity must flow through the electromagnet. If, as in the prior art, the vehicle's on-board voltage is simply applied to the electromagnet, the electromagnet must be designed so that the holding force remains reliable even if the on-board voltage has its permissible minimum. It should be noted that the vehicle's on-board voltage can fluctuate over a considerable range, particularly depending on the battery's state of charge. However, this means that when the on-board voltage is within its normal or higher range, the current flowing through the electromagnet exceeds the required current, thus consuming an unnecessarily large amount of current.

[0009] Therefore, according to the present invention, the control device has at least one DC-DC converter serving as a constant current source between the power input and the power output, such that the current intensity in the first active switching state has a defined first value independent of the voltage applied to the power input. This DC-DC converter, as a constant current source, is widely used technically, has high efficiency, and is very inexpensive within the relevant power supply range.

[0010] By using a DC-DC converter as a constant current source, the electromagnet of the actuator unit only receives the current "it needs," which saves current compared to existing technologies.

[0011] Typically, the initial current intensity is between 50mA and 500mA.

[0012] In a particularly preferred embodiment, the control device has not only one but two active switching states, wherein the current intensity in the second active switching state has a higher value than that in the first active switching state. Preferably, even in the second active switching state, the current intensity has a defined second value; this is larger than the first value. This particularly preferred embodiment of the invention is based on the consideration that if the control device switches from a passive switching state to an active switching state, the electromagnet of the actuator unit should move the movable element from a first position to a second position. Typically, this movement signifies the unlocking of the latching unit. Thereafter, the latching unit is typically held in the unlocked position relatively often and for a relatively long time, that is, the element that can be moved by the electromagnet remains stationary, but is held by the electromagnet. It has been found that the force required for the electromagnet to move the element driven by the electromagnet is much greater than the force required for the electromagnet to hold the element in its "held by electromagnet" position. Of course, this also means that the current intensity required to change the state is greater than the current intensity required to hold the state. Since the "held state" typically lasts much longer than the actual state, a significant amount of energy can be saved if the current flowing through the electromagnet in the held state is less than the current during the switching process. To achieve precisely defined switching behavior and further minimize energy consumption and wear, the current intensity, even in the second active switching state, preferably has a defined value independent of the voltage applied to the power input. This means that even in this second active switching state, the current flowing through the electromagnet is provided by a DC-DC converter. A switchable DC-DC converter can be used to implement both active switching states. However, since the first active switching state typically lasts for a much longer time than the second active switching state, the current flowing through the electromagnet in the second active switching state does not necessarily have to be provided by a DC-DC converter for energy saving, compared to existing technologies. The circuit must be selected in such a way that the current intensity in the second active switching state is sufficient under all circumstances (even at low voltages of the onboard power supply) to ensure the movement of the components driven by the electromagnet.

[0013] The design of the belt winder unit according to the present invention provides further advantages: Of course, the control current of the electromagnet also requires a control voltage. With the help of a DC-DC converter, the voltage across the electromagnet is independent of the vehicle battery voltage. This means that any fluctuations in the vehicle battery voltage can be compensated for.

[0014] While energy saving can be achieved using PWM control, its drawback is that it typically generates EMC-related interference. However, since no PWM frequency is generated, the present invention uses DC power to minimize any EMC-related interference.

[0015] As mentioned earlier, the strength of an electromagnet's magnetic field depends primarily on the current. Therefore, since a constant current always flows through the electromagnet, a DC-DC converter can also compensate for temperature dependence and aging effects.

[0016] The invention will now be described in more detail with reference to the preferred embodiments shown in the figures. It is illustrated that: Figure 1 shows a schematic diagram of a tape winder unit, wherein the tape winder of the tape winder unit is shown in a schematic side-top view, wherein the control device is in its passive switching state, and wherein the tape winder is in its locked state. Figure 2 shows a schematic top view of the belt winder shown in Figure 1. Figure 3 As shown in Figure 1, the control device is in the active switch state, while the belt winder is in its unlocked state. Figure 4a The figures in Figure 1 and 1 are shown. Figure 3 A more detailed illustration of a simplified embodiment of the control device is shown, wherein it is in a first active switching state. Figure 4b It shows Figure 4a The control device in the middle, wherein it is in its second active switching state, Figure 4c It shows Figure 4a and Figure 4b The control device in the middle, wherein it is in its passive switch state, and Figure 5 A typical time-current intensity diagram of the current flowing through the electromagnet of the locking unit is shown.

[0017] Referring to Figures 1 and 2, the basic features of the tape winder unit of the present invention will first be described. It should be noted that these figures are highly schematic and only illustrate the basic principles of the invention. The tape winder unit can be considered to consist of a tape winder 10 and a control device 50. In this case, the control device 50 could be directly connected to the housing of the tape winder 10, but this is not necessary; therefore, in Figures 1 and 2, the basic features of the tape winder unit will be described first. Figure 3 In this context, it is also referred to as being removed from the housing. Of course, the control unit and the belt winder must be electrically connected.

[0018] The following is a schematic diagram of the electrical circuit (excluding the return line). Here, power lines are shown as solid lines, and signal lines are shown as lines in a "dash-colon-dash" pattern.

[0019] The tape winder 10 typically consists of a housing 10, a tape coil 20 rotatably supported within the housing, a section of tape 5 wound on it, and a locking unit for locking the tape coil 20 within the housing 12. In the illustrated embodiment, the housing 12 has two housing plates 14a, 14b connected by connecting bolts 16; however, this is only to be understood as exemplary. Typically, and also shown here, the locking unit has a locking wheel 22 tightly connected to the tape coil 20. Furthermore, a latch 24a is provided that locks the locking wheel 22 and thus the tape coil 20 onto the housing 12 in the locked state (FIG. 1), but in the released state (FIG. 1). Figure 3 (Don't do this.)

[0020] Importantly, the position of the latch 24a is directly (as shown) or indirectly controlled by the actuator unit 40, which has an electromagnet 42. In the illustrated embodiment, this effect is given by the fact that, in addition to the electromagnet 42, the actuator unit 40 has a lever 44 driven by the electromagnet, which acts on the lever 24 of the latch 24a. When a sufficiently strong current flows through the electromagnet, it pushes the lever 44 outward. However, as mentioned earlier, it must be noted that this configuration should only be understood as an example. Importantly, the locking unit has an electromagnet, such that the actuator unit relies on the current flowing through the magnet to control the locking unit. Typically, also as shown, a spring, here a tension spring 30 or other elastic element, is provided, which explicitly defines the state of the locking unit when the electromagnet 42 of the actuator unit 40 is de-energized and therefore does not exert force on the lever it drives. As shown, this de-energized state is the locked state.

[0021] Such electrically controlled interlocking units with electromagnets are known in the prior art. Therefore, this invention relates only to the manipulation of the electromagnet, i.e., the control device 50.

[0022] As described above, the core of this invention lies in the fact that the control device 50 has at least one DC-DC converter as a constant current source, such that in the first active switching state of the control device 50, a current of sufficient strength to maintain the desired state (i.e., the unlocked state) is supplied to the electromagnet only. As described above, the control device preferably has three switching states: a first active switching state, a second active switching state, and a passive switching state. In the passive switching state, the control device does not supply current to the electromagnet; in the first active switching state, the control device supplies current to the electromagnet with a defined first value I1; and in the second active switching state, the control device supplies current to the electromagnet with a defined second value I2. A possible schematic circuit diagram of such a control device is shown below. Figures 4a to 4c As shown, and described below: The control unit has a power input 55 connected to the vehicle's onboard power supply and a power output 56 connected to the electromagnet 42 of the actuator unit 40. Furthermore, the control unit has a signal input 57 and / or its own sensor unit 52 (both are present in the illustrated embodiment, but not mandatory), a switchable DC-DC converter 60, and a logic unit 54. The sensor unit 52 may, in particular, be an acceleration sensor, which then outputs a signal to the logic unit 54 when an acceleration exceeds or falls below a predetermined acceleration value. Based on the obtained signal, the logic unit 54 operates the switchable DC-DC converter 60, which is capable of providing three defined current intensities to the electromagnet 42 via the power output 56, starting from the onboard voltage supplied to it through the power input 55. In the illustrated embodiment, the DC-DC converter 60 has a first converter unit 61 for generating a defined first current intensity with a first value I1, a second converter unit 62 for generating a defined second current intensity with a second value I2, and a selection switch 64 with three positions, where I2 > I1. The selection switch 64 is operated by the logic unit 54. Figure 4a When the selector switch 64 is in the switched state shown, the first converter unit 61 supplies current to the electromagnet. Figure 4b In the shown switching state, the second converter unit 62 supplies current to the electromagnet. Figure 4b In the shown switching state, the electromagnet is de-energized. At least when the vehicle voltage is applied to the power input 55, the switching state of the control unit corresponds to the switching state of the selector switch.

[0023] Figure 5 The operation mode of logic unit 54 based on output current is shown.

[0024] When the vehicle is not running, its power grid is typically off, which means the electromagnet is not powered, and therefore the belt winder is in the state shown in Figure 1. Alternatively or additionally, the selector switch can be in the position shown in Figure 1. Figure 4c The switch state is shown. According to the definition chosen here, the control device is in a passive switch state. Now, when the vehicle starts, logic unit 54 controls selector switch 64 at time t0 (e.g., after system testing) in such a way that it is in the following state: Figure 4b The switch state shown causes a current of intensity I2 to flow through the electromagnet 42, generating sufficient force to move the push rod 44, thereby placing the locking unit in its unlocked state. After a predetermined time interval... After t (this time interval can be less than one second), logic unit 54 now manipulates selector switch 64 to transition to Figure 4aThe switch state is shown, thereby the first converter unit 61 supplies a current of intensity I1 to the electromagnet. This current intensity I1 is sufficient to keep the locking unit in its unlocked state. Now, if a signal indicating an accident is provided to the logic unit 54 via signal input 57 or via sensor unit 54, the logic unit 54 operates the selector switch 64 in such a way that it transitions to its open state. Figure 4c This interrupts the current to electromagnet 42 and transitions the tape winder to the state shown in Figure 1. If the signal changes again so that no accident or dangerous situation occurs, the above process is repeated, i.e., first, a current of intensity I2 is applied at a time interval... A current of intensity I1 flows through the electromagnet within time t, and then flows through the electromagnet after that time interval.

[0025] Therefore, it is important that when transitioning from the locked state to the unlocked state, a stronger current flows through the magnet initially, while in the subsequent holding state, a weaker current flows through the magnet.

[0026] Therefore, compared with existing technologies, the overall power consumption is significantly reduced, which is a great advantage for vehicles that are fully or partially powered by electricity.

[0027] List of icon symbols 10-belt winder 12 shells 14a, b shell plates 16 connecting bolts 18. Support for spring and actuator unit 20-belt coil 22 locking wheels 24 levers 24a latch 30 tension spring 40 actuator units 42 Electromagnets 44 pushers 50 control devices 52 sensor units 54 logic units 55 power input 56 power output 57 signal input 60-way switchable DC-DC converter 61 First Converter Unit 62 Second Converter Unit 64 Selector Switch

Claims

1. Belt winder unit, with Shell (10) A belt coil (20) is rotatably supported in the housing (10). A locking unit for locking the tape coil onto the housing, wherein... The locking unit has an actuator unit (40) with an electromagnet (42), and A control device (50) for manipulating the electromagnet (42) has a power input (55), a power output (56) connected to the electromagnet (42), and at least one signal input (57) for receiving control signals and / or a sensor unit (52) for generating control signals. The control device (50) has at least one first active switching state and one passive switching state. In the first active switching state, current flows between the power output (56) and the electromagnet (42), and the current intensity is greater than that in the passive switching state. The control device (50) is characterized in that it has at least one DC-DC converter (60) as a constant current source between the power input and the power output, such that the current intensity in the first active switching state has a first value (I1) defined to be independent of the voltage applied to the power input. The control device (50) has a second active switch state, wherein the current intensity is greater than that in the first active switch state; When the control device (50) is in a passive switch state, the belt coil (20) is locked onto the housing (10); When the belt coil (20) is unlocked, the control device (50) first switches from the passive switch state to the second active switch state, and then switches back to the first active switch state.

2. The belt winder unit according to claim 1, characterized in that, The first value (I1) is between 50 mA and 500 mA.

3. The belt winder unit according to claim 1, characterized in that, The current intensity in the second active switching state has a second value (I2) defined as independent of the voltage applied to the power input (55), wherein the second value is greater than the first value.

4. The belt winder unit according to claim 3, characterized in that, The second value (I2) is at least twice the first value (I1).

5. The belt winder unit according to claim 4, characterized in that, The second value (I2) is between 150 mA and 1500 mA.

6. The belt winder unit according to claim 1, characterized in that, In time interval The second active switch remains in state for t, where 5 ms ≤ t ≤ 200 ms.

7. The belt winder unit according to claim 6, characterized in that, 20 ms ≤ t ≤ 50 ms。 8. The belt winder unit according to claim 1, characterized in that, In the passive switch state, the current intensity between the power output (56) and the electromagnet (42) is essentially zero.

9. A vehicle equipped with an electric drive unit, having a belt winder unit according to any one of claims 1 to 8.

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