Vehicle seat with easy-entry function

Abstract

The vehicle seat (2) with an easy-entry function has a seat part (4) and a backrest (6) and an adjustment mechanism (10A, 10B) for an adjustment movement, wherein the adjustment mechanism (10A, 10B) has a drive unit (14) with an electric motor (16) and a control unit (18) for controlling the electric motor (16). The electric motor (16) is designed as a brushless DC motor and the control unit (18) is designed to carry out two operating modes such that the electric motor (16) is operated at a low rotational speed for a normal adjustment and at a high rotational speed, which is higher than the low rotational speed, for a quick adjustment into an easy-entry position. By this means, a structurally simple and convenient quick adjustment into an easy-entry position is achieved.

Description

[0001] Page 1

[0002] Description

[0003] Vehicle seat with easy-entry function

[0004] The invention relates to a vehicle seat with an easy-entry function.

[0005] Automotive seats are often equipped with an entry aid known as an easy-entry function to simplify access to the rear seats. This is the case, for example, in two-door vehicles to facilitate access to the second row of seats, or in vehicles with more than two rows of seats to enable access to the rearmost row.

[0006] Vehicle seats designed in this way can be adjusted from a normal position to an easy-entry position, in which the seat is moved forward and / or the backrest is folded forward. For electrically adjustable backrests, a manual release mechanism is typically incorporated for quick folding of the backrest. This release mechanism is typically operated by a cable, for example. The release mechanism creates a bypass function, effectively bypassing the electric motor and allowing free manual adjustment of the backrest to quickly move it into the desired, forward-folded easy-entry position.

[0007] Such a vehicle seat with such a release mechanism can be found, for example, in DE 10 2022 208 805 A1. Due to the required release mechanism, the adjustment mechanism as a whole is complex and elaborately constructed.

[0008] 2024 177 WO Page 2

[0009] Based on this, the invention aims to enable a comfortable adjustment of a vehicle seat into an easy-entry position with minimal mechanical effort.

[0010] The problem is solved according to the invention by a vehicle seat according to claim 1, in particular by a vehicle seat with an easy-entry function, which comprises a seat section and a backrest as well as an adjustment mechanism for adjusting the vehicle seat, wherein the adjustment mechanism comprises a drive unit with an electric motor and a control unit for controlling the electric motor and the adjustment movement. The electric motor is designed as a brushless DC motor and the control unit is configured to operate in two modes. According to a first operating mode for normal adjustment, the electric motor is operated at a low speed, and according to a second operating mode for rapid adjustment to a desired easy-entry position, the electric motor is operated at a high speed, which is higher than the low speed.

[0011] The use of a brushless DC motor as the electric motor offers the advantage of precise adjustment, particularly of the motor's speed over a wide range, due to the characteristics of such motors. This is utilized by operating the electric motor at a higher speed for quick adjustments to and from the easy-entry position compared to a normal adjustment, where, for example, the user moves the backrest to their desired seating position. The higher speed results in a faster overall adjustment than with the normal adjustment. Such brushless DC motors are also known as BLDC motors (brushless DC motors).

[0012] The quick adjustment mechanism therefore replaces the manual unlocking and adjustment previously required for electrically adjustable seats. This results in improved comfort and reduced design complexity.

[0013] 2024 177 WO Page 3

[0014] Normal adjustment generally refers to an adjustment made by the user while seated in the vehicle to bring it into a desired, comfortable seating position. Quick adjustment, on the other hand, refers to the described adjustment to the Easy Entry position, in which there is usually no user in the vehicle seat, or back from the Easy Entry position to a normal position.

[0015] In the simplest case, the drive unit is the electric motor; alternatively, the drive unit also includes a gearbox in addition to the electric motor.

[0016] In a preferred embodiment, the high rotational speed is at least twice, and preferably at least five or even ten times, higher than the low rotational speed. This results in a significantly faster adjustment movement compared to a normal adjustment.

[0017] The actual adjustment movement into the assigned easy-entry position is preferably also faster by at least these factors than the adjustment movement in a normal adjustment.

[0018] For example, with an electric motor-driven tilt adjustment, the backrest is adjusted at a low speed of, for example, 37s in normal adjustment mode and at a high speed of, for example, 207s in quick adjustment mode.

[0019] Preferably, the electric motor is operated, or can be operated, with a high torque during normal adjustment and with a lower torque during rapid adjustment, which is less than the high torque. Here, too, the characteristic of the brushless DC motor is utilized, in which, in addition to the rotational speed, the torque can also be precisely adjusted over a wide range by means of suitable control.

[0020] 2024 177 WO Page 4

[0021] According to an advantageous further development, a first torque limit can be set or adjustable during normal adjustment, and a second torque limit can be set or adjustable during quick adjustment, with the second torque limit allowing a lower torque than the first. If a user or object is positioned on the vehicle seat during quick adjustment, reducing the torque can better prevent damage caused by pinching or crushing during the adjustment. This is particularly useful during quick adjustment, as there is less reaction time to react to a potential pinching situation during the process.

[0022] According to an advantageous embodiment, the control unit can be configured or adjustable such that, in normal mode, adjustment is possible over a shorter range than in quick mode. In particular, in normal mode, adjustment can be limited to a partial range of the adjustment path compared to quick mode. This can be achieved, for example, by incorporating at least two soft stops, especially where further adjustment beyond the first soft stop is not possible in normal mode. This has the advantage that the normal mode is primarily used for comfort adjustments to the vehicle seat, while the quick mode is intended to improve access to the vehicle by allowing for a wider range of seat adjustment.

[0023] According to further training, the control unit and / or a higher-level control unit can include a memory and be configured to save the current position of a vehicle seat section and / or the backrest before a quick adjustment is performed, so that a return to the same position is possible. This prevents the user from having to manually adjust the vehicle seat to a desired position, particularly using the normal adjustment mechanism, after performing a quick adjustment.

[0024] 2024 177 WO Page 5

[0025] According to further training, at least one separate input device for a user to enter an operating command can be provided for both the normal adjustment and the quick adjustment. This can significantly simplify operation for the user, especially since they can better distinguish whether they are performing a normal or a quick adjustment. For example, this prevents the vehicle seat position from being accidentally adjusted using the quick adjustment function.

[0026] According to further training, the adjustment mechanism can be designed as a backrest tilt adjuster, a backrest headrest adjuster, a seat longitudinal adjuster, and / or a seat height adjuster. Depending on the vehicle and requirements, combinations of two or three of the aforementioned adjusters can also be used, particularly via a normal adjustment and / or quick adjustment, which may occur at least partially simultaneously. This can improve access to a vehicle, such as to the rear seats.

[0027] The high torque used in the normal adjustment ensures reliable movement even under load. In contrast, a lower torque is sufficient for the quick adjustment to the easy-entry position, as this movement occurs under significantly less load since no one is on the seat.

[0028] The high and low torques also differ, in particular, by at least a factor of 2, and preferably by at least a factor of 5 or at least a factor of 10.

[0029] In a preferred embodiment, the adjustment to the easy-entry position is exclusively driven by the electric motor, and manual adjustment is not possible, meaning the vehicle seat, and especially the backrest, cannot be moved manually into the easy-entry position. "Manual adjustment" in this context refers to the possibility of manually adjusting the seat to the easy-entry position by bypassing the electric motor drive, as described below.

[0030] As explained previously in section 6 of page 2024, the unlocking mechanism and the bypass function it creates are therefore unnecessary. This significantly reduces the mechanical complexity compared to a conventional adjustment mechanism with such a release mechanism.

[0031] According to an alternative variant, such a release mechanism is additionally designed to allow manual operation, for example in the event of a failure of the drive unit.

[0032] In a preferred embodiment, the easy-entry position is achieved by adjusting the tilt of the backrest, whereby the drive unit swivels along with the backrest. This results in a compact and space-saving arrangement overall.

[0033] Alternatively, and especially in combination, the easy-entry position is achieved by longitudinally adjusting the vehicle seat, whereby the drive unit is also preferably adjusted together with the vehicle seat. Alternatively, the drive unit is fixed in place during longitudinal adjustment.

[0034] Preferably, the easy-entry position is achieved by both tilt adjustment and longitudinal adjustment. Separate adjustment mechanisms with their own drive units, as described herein, are provided for both tilt adjustment and longitudinal adjustment.

[0035] In a practical design, the drive unit includes both the electric motor and the control unit, and these two components are arranged within a common housing. The drive unit is therefore designed as a single unit with an integrated control unit. The electric motor is controlled decentrally via the control unit. Control via a central, remote control unit is not provided.

[0036] 2024 177 WO Page 7

[0037] In a preferred embodiment, the drive unit further comprises a gearbox, which is also arranged within the common housing and is thus part of the drive unit assembly.

[0038] The drive unit generally has an output shaft, which is either the exiting motor shaft of the electric motor or, in a gearbox version, the exiting gearbox shaft. This output shaft is a mechanically rigid shaft that typically protrudes only a few centimeters, for example, a maximum of 10 cm or a maximum of 5 cm, from the common housing. This output shaft preferably acts directly on a drive element to perform the adjustment movement. Specifically, a worm gear is mounted on the output shaft, which meshes with the drive element; that is, the drive element has corresponding teeth into which the worm gear engages.

[0039] Alternatively, specifically for longitudinal adjustment, the drive element is designed as a spindle nut of a spindle drive. Specifically, the worm gear meshes with teeth, particularly external teeth, on the spindle nut, which is mounted on a spindle shaft. Here, too, the desired compact design and direct connection to the adjustment mechanism are achieved through the direct meshing of the worm gear on the output shaft. The drive unit is, for example, arranged laterally, particularly on a side panel of a seat frame. Alternatively, it is mounted in a central area on a support between two opposing side panels.

[0040] In a preferred embodiment, a flexible shaft is omitted, via which the rotary motion of the electric motor is transmitted over a comparatively long distance of typically several tens of centimeters.

[0041] In a preferred embodiment, the adjustment mechanism is self-locking. This means that if an external force is applied, i.e., one not exerted by the electric motor, the adjustment is inhibited and does not occur. This serves to improve crash safety.

[0042] 2024 177 WO Page 8

[0043] According to further training, the control unit can be designed as a control unit integrated into the drive unit and / or as a control unit assigned to the drive unit, in particular as a superior control unit, in particular where the superior control unit can be assigned or assignable to several drive units.

[0044] According to further training, the Easy-Entry function can be designed to enable a user to enter a rear seat more easily and / or to provide simplified access and / or an extension for luggage storage space.

[0045] An embodiment of the invention is explained in more detail below with reference to the figures. These show

[0046] FIG 1 shows a highly simplified side view of a vehicle seat as well as

[0047] FIG 2 shows an enlarged partial view of a drive unit whose output shaft acts on a gearbox for adjusting the inclination of a backrest.

[0048] Figure 1 shows a highly simplified representation of a vehicle seat 2. The vehicle seat 2 has a seat section 4 and a backrest 6 pivotally attached to it. The seat section 4, and thus the entire vehicle seat 2, is longitudinally adjustable along longitudinal rails 8.

[0049] For various adjustment movements, the vehicle seat has two different adjustment mechanisms 10A-10C: a first adjustment mechanism 10A for adjusting the tilt of the backrest 6, a second adjustment mechanism 10B for adjusting the longitudinal position of the vehicle seat 2, and a third adjustment mechanism 10C for adjusting the height of the seat section 4. Each of these adjustment movements is electrically adjustable by means of a respective drive unit 14.

[0050] 2024 177 WO Page 9

[0051] Each drive unit 14 comprises an electric motor 16 designed as a brushless DC motor and a control unit 18. The control unit 18 and the electric motor 16 are arranged within a common housing 20 and thus form a single assembly. The electric motor 16 and the control unit 18 are concealed by the housing 20 in the figures and are therefore not explicitly visible.

[0052] The first adjustment mechanism 10A for adjusting the tilt of the backrest has, in addition to the drive unit 14, in particular a gearbox 22, as can be seen from FIG 2.

[0053] The drive unit 14 has an output shaft 24, which is formed by the motor shaft of the electric motor 16 and on which a worm gear 26 is mounted. This meshes with a drive element 28 of the gearbox 22, which is designed as a gear wheel, and drives it in a manner known per se.

[0054] The various drive units 14 can be individually controlled for comfort adjustment, allowing the user to adjust the vehicle seat 2 to a comfortable position while seated in it. For this comfort adjustment, the respective electric motor 16 is operated at a predetermined, typically constant, low speed. The electric motor 16 is appropriately controlled by the control unit 18.

[0055] Vehicle seat 2 is also equipped with an easy-entry function. With this function, the backrest is folded forward into an easy-entry position. The adjustment range from a normal upright seating position, as shown in FIG. 1, to the forward-folded easy-entry position is typically at least 20° or at least 30°.

[0056] Preferably, a longitudinal adjustment is also performed, whereby the vehicle seat is moved forward into a predetermined easy-entry position. In particular, the vehicle seat is moved to a forward end stop.

[0057] 2024 177 WO Page 10

[0058] To adjust the door to the desired easy-entry position, the control unit 18 activates the electric motor 16 in a second operating mode to perform a rapid adjustment to the desired easy-entry position. In this mode, the electric motor 16 operates at a high speed, which is at least twice, preferably at least five times, or even ten times higher than the low speed used in the previously described comfort adjustment. Simultaneously, the electric motor 16 operates with a lower torque than in the comfort adjustment mode.

[0059] Manual adjustment to the easy-entry position has been omitted. Specifically, vehicle seat 2 lacks a release mechanism that would conventionally allow manual swiveling of the backrest 6, bypassing the drive unit 14. This minimizes the overall design complexity and reduces costs and weight. Simultaneously, the high-speed electric motor assistance during quick adjustment provides a high level of user comfort.

[0060] Another crucial advantage is that fewer variants and therefore fewer different types of vehicle seats are required, for example, for use in a vehicle series with different variants, such as a two-door (coupe) and a four-door (sedan) version. The same vehicle seats can therefore be used for these different variants, since the easy-entry function required only for the two-door version is achieved simply by controlling the electric motor, without any further design modifications being necessary.The provision of the Easy-Entry function is therefore generally characterized in particular by the fact that it is provided solely on the basis of the control of the electric motor and that, in comparison to a vehicle seat 2 without Easy-Entry function, preferably no design changes have been made.

[0061] 2024 177 WO Page 11

[0062] Reference symbol list

[0063] 2 vehicle seats

[0064] 4 Seat section 6 Backrest

[0065] 8 Longitudinal rail

[0066] 10A-C Adjustment Mechanism

[0067] 14 Drive unit

[0068] 16 Electric motor 18 Control unit

[0069] 20 cases

[0070] 22 gearboxes

[0071] 24 Output shaft

[0072] 26 Worm gear 28 Drive element

[0073] 2024 177 WO

Claims

Page 12 Claims 1. Vehicle seat (2) with easy-entry function, comprising a seat section (4) and a backrest (6) as well as an adjustment mechanism (10A, 10B) for an adjustment movement, and the adjustment mechanism (10A, 10B) comprising a drive unit (14) with an electric motor (16) as well as a control unit (18) for controlling the electric motor (16), wherein the electric motor (16) is designed as a brushless DC motor and the control unit (18) is designed to perform two operating modes, such that for a normal adjustment the electric motor (16) is operated at low speed and for a quick adjustment to an easy-entry position at a high speed which is higher than the low speed.

2. Vehicle seat (2) according to the preceding claim, wherein the high rotational speed is at least by a factor of 2 and preferably at least by a factor of 5 or 10 higher than the low rotational speed.

3. Vehicle seat (2) according to one of the preceding claims, wherein the electric motor (16) can be operated or is operated with a high torque during normal adjustment and with a low torque during rapid adjustment, wherein the low torque is less than the high torque.

4. Vehicle seat (2) according to one of the preceding claims, characterized in that a first torque limit is set or adjustable during normal adjustment and a second torque limit is set or adjustable during quick adjustment, wherein the second torque limit allows a lower torque than the first torque limit.

5. Vehicle seat (2) according to one of the preceding claims, characterized in that the control unit (18) is configured or adjustable such that, in normal adjustment, an adjustment over a smaller adjustment range is possible than in quick adjustment, 2024 177 WO Page 13 6. Vehicle seat (2) according to one of the preceding claims, characterized in that in the normal adjustment, adjustment is only possible over a partial range of the adjustment path of the quick adjustment.

7. Vehicle seat (2) according to one of the preceding claims, characterized in that the control unit (18) and / or a superior control unit includes a memory and is configured to store a current position of the seat part (4) and / or the backrest (6) before performing a quick adjustment, so that a return adjustment to the same position is possible.

8. Vehicle seat (2) according to one of the preceding claims, characterized in that at least one separate input device for inputting an operating command by a user is provided for the normal adjustment and the quick adjustment.

9. Vehicle seat (2) according to one of the preceding claims, characterized in that the adjustment mechanism (10A, 10B) is designed as a backrest tilt adjuster and / or as a backrest head adjuster and / or as a seat longitudinal adjuster and / or as a seat height adjuster.

10. Vehicle seat (2) according to one of the preceding claims, wherein the adjustment to the easy-entry position is exclusively driven by an electric motor using the electric motor (16) and no free adjustment is possible, wherein a seat part (4) can be manually moved into the easy-entry position.

11. Vehicle seat (2) according to one of the preceding claims, wherein the easy-entry position is achieved by an inclination adjustment of the backrest (6) and the drive unit (14) pivots with the backrest (6).

12. Vehicle seat (2) according to one of the preceding claims, wherein the quick adjustment to the easy-entry position is a tilt adjustment of the 2024 177 WO Page 14 The system comprises a backrest (6) and a longitudinal adjustment of the vehicle seat (2), with each of the two adjustment movements having its own drive unit (14).

13. Vehicle seat (2) according to one of the preceding claims, wherein the drive unit (14) comprises the electric motor (16) and the control unit (18), and the electric motor (16) and the control unit (18) are arranged within a common housing (20).

14. Vehicle seat (2) according to one of the preceding claims, wherein the drive unit (14) has a rigid output shaft (24) with a worm gear (26) which meshes directly with a drive element (28) for performing the adjustment movement.

15. Vehicle seat (2) according to one of the preceding claims, wherein the drive element (28) is a gear wheel, in particular of a wobble gear or a spindle nut.

16. Vehicle seat (2) according to one of the preceding claims, wherein the adjustment mechanism (10A, 10B) is self-locking.

17. Vehicle seat (2) according to one of the preceding claims, characterized in that the control unit (18) is designed as a control unit integrated into the drive unit (14) and / or as a control unit assigned to the drive unit (14), in particular a superior control unit.

18. Vehicle seat (2) according to claim 17, characterized in that the superior control unit is assigned or assignable to several drive units (14).

19. Vehicle seat (2) according to one of the preceding claims, characterized in that the Easy-Entry function is designed to enable simplified entry of a user onto a rear seat and / or simplified access and / or an extension for a luggage storage space. 2024 177 WO

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