ADJUSTMENT MECHANISM COMPRISING A LINEAR ACTUATOR, VEHICLE AND METHOD FOR OPERATING A VEHICLE

Abstract

An adjustment mechanism, in particular for a vehicle, for example a lawn mower, comprises a linear actuator, which has a motor, a transmission arrangement and a displaceable output element, and a manually operable actuation mechanism, wherein there is a coupling element which is displaceable relative to the output element, which represents both a component of the linear actuator and a component of the manual actuation mechanism and which, in a mechanical mode, permanently rests against a stop of the output element, whereas, in a manual mode, it can be lifted off from the stop by means of the actuation mechanism.

Claims

1. An adjustment mechanism comprising: a linear actuator including a motor, a transmission arrangement and a displaceable output element; and a manually operable actuation mechanism; wherein a coupling element is displaceable relative to the output element, which represents both a component of the linear actuator and a component of the manually operable actuation mechanism and which, in a mechanical mode, permanently rests against a stop of the output element, whereas, in a manual mode, the coupling element can be lifted off from the stop by the manually operable actuation mechanism.

2. The adjustment mechanism according to claim 1, wherein the linear actuator comprises a screw drive.

3. The adjustment mechanism according to claim 2, wherein the screw drive includes a ball screw drive.

4. The adjustment mechanism according to claim 2, further comprising a reduction gear in the form of a continuously variable transmission connected upstream of the screw drive.

5. The adjustment mechanism according to claim 2, wherein the screw drive has a spindle nut as an output element.

6. The adjustment mechanism according to claim 2, wherein the screw drive has a threaded spindle as an output element.

7. The adjustment mechanism according to claim 1, wherein the linear actuator is configured to transmit a force to the coupling element in exactly one axial direction.

8. The adjustment mechanism according to claim 1, wherein a pedal is provided for manually displacing the coupling element.

9. A vehicle comprising: an adjustment mechanism having: a linear actuator including a motor, a transmission arrangement and a displaceable output element; and a manually operable actuation mechanism; wherein a coupling element is displaceable relative to the output element, which represents both a component of the linear actuator and a component of the manually operable actuation mechanism and which, in a mechanical mode, permanently rests against a stop of the output element, whereas, in a manual mode, the coupling element can be lifted off from the stop by the manually operable actuation mechanism.

10. The vehicle according to claim 9, wherein the vehicle is a lawn mower including a mower, and the adjustment mechanism is configured to set a height of the mower.

11. A method for operating a vehicle having a mower, the method comprising: varying a height setting of a mower mechanically with a linear actuator, within a predetermined adjustment range by means of the adjustment mechanism and, if the mower is not raised to the maximum, a manual change in the height setting of the mower is carried out as required within a remaining adjustment range up to the maximum raised position of the mower.

12. The method according to claim 11, wherein the vehicle includes an adjustment mechanism including the linear actuator, the linear actuator including a motor, a transmission arrangement and a displaceable output element; and a manually operable actuation mechanism; wherein a coupling element is displaceable relative to the output element, which represents both a component of the linear actuator and a component of the manually operable actuation mechanism and which, in a mechanical mode, permanently rests against a stop of the output element, whereas, in a manual mode, the coupling element can be lifted off from the stop by the manually operable actuation mechanism.

13. The method according to claim 12, wherein the linear actuator comprises a screw drive.

14. The method according to claim 13, wherein the screw drive includes as a ball screw drive.

15. The method according to claim 13, further comprising a reduction gear in the form of a continuously variable transmission connected upstream of the screw drive.

16. The method according to claim 13, wherein the screw drive has a spindle nut as an output element.

17. The method according to claim 13, wherein the screw drive has a threaded spindle as an output element.

18. The method according to claim 12, wherein the linear actuator is configured to transmit a force to the coupling element in exactly one axial direction.

19. The method according to claim 12, wherein a pedal is provided for manually displacing the coupling element.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Exemplary embodiments of the disclosure are explained in more detail below by means of drawings. The figures show the following in an, in parts, roughly schematized manner:

[0022] FIG. 1 shows a vehicle, namely a lawn mower designed as a ride-on mower, including an adjustment mechanism for varying the height setting of a mower, in a schematic side view,

[0023] FIG. 2 shows an electromechanical actuator of the vehicle according to FIG. 1, intended for the height adjustment of the mower,

[0024] FIG. 3 shows a second embodiment of an adjustment mechanism for a vehicle comprising a linear actuator in a first setting, namely with the threaded spindle of the linear actuator extended to its maximum and the coupling element, which is also manually displaceable, resting against a stop of the threaded spindle,

[0025] FIG. 4 shows the adjustment mechanism according to FIG. 3, wherein here too the threaded spindle is extended to its maximum, but the coupling element is lifted from the stop,

[0026] FIG. 5 shows the adjustment mechanism according to FIG. 3 with partially retracted threaded spindle, wherein the coupling element rests against the stop,

[0027] FIG. 6 shows a diagram showing the relationship between mechanical and manual actuation options of the adjustment mechanism according to FIGS. 3 to 5.

DETAILED DESCRIPTION

[0028] Unless otherwise stated, the following explanations relate to all the exemplary embodiments. Parts that correspond to each other or have basically the same effect are denoted with the same reference signs in all the figures.

[0029] A vehicle identified overall with the reference number 1 is a ride-on mower, the chassis of which is designated 2 and the wheels of which are designated 3, 4. A mower 5 located under the chassis 2 can be adjusted either electromechanically or manually by means of a height adjustment 6, which will be discussed in more detail below.

[0030] In addition to a seat 7 fastened to the chassis 2, a control unit 8 is arranged, which is linked to an actuator 9, namely a linear actuator, which is provided for the motor actuation of the height adjustment 6, i.e., the adjustment mechanism. The adjustment of the mower 5 by means of the actuator 9 is referred to as the first adjustment mode.

[0031] In addition to the first adjustment mode, there is a second, manual adjustment mode, which does not require electrical energy. For this purpose, a pedal 10 is placed in front of the seat 7. A manually operated lever can also be used instead of the pedal 10. This applies in particular to embodiments not shown in which the vehicle 1 is designed as a self-propelled device without a driver's seat. The pedal 10 is attached to a lever 11, which is referred to without restriction of generality as the front lever. A center pivot point 12 of the lever 10 is located on the chassis 2, while a lower pivot point 13 is located on the mower 5. Furthermore, the lever 11 is connected in an articulated manner to a rod 14 in the section between the center pivot point 12 and the pedal 10, which in the present case is located in a horizontal orientation above the chassis 2.

[0032] The rear end of the rod 14, the left end in the arrangement according to FIG. 1, is coupled in an articulated manner to a second, rear lever 15. Overall, the rear lever 15 has a basic shape comparable to the front lever 11. In the case of the rear lever 15, a center pivot point is designated 16 and a lower pivot point is designated 17. At an upper pivot point 18 of the lever 15, an articulated connection to a push rod 19 is established, which in the embodiment according to FIGS. 1 and 2 is a coupling element of the adjustment mechanism 6.

[0033] The push rod 19 is part of a screw drive, designated overall with 20, in this case a ball screw drive, of the actuator 9. In the present cases, the ball screw drive 20 is designed as a non-self-locking screw drive, i.e., as a screw drive which can also be operated from the output side. Alternatively, a self-locking design of the screw drive 20 can be considered.

[0034] A threaded spindle of the ball screw drive 20 is designated 21 in each embodiment. In the case of FIGS. 1 and 2, a corresponding spindle nut 22 is guided in a non-rotatable manner as the output element of the ball screw drive 20. In the exemplary embodiments according to FIGS. 3 and 5, the threaded spindle 21 represents the output element of the ball screw drive 20. In both cases, the output element 21, 22 provides a stop 27 for a coupling element 19, 29, wherein in the case of FIGS. 1 and 2 is in the form of a hollow push rod 19 and in the case of FIGS. 3 to 5 is in the form of a sliding sleeve 29. In any case, it is possible to act on the coupling element 19, 29 by means of the pedal 10.

[0035] The push rod 19 is displaceably mounted in a housing part 23 of the actuator 9 as shown in FIG. 2. In an analogous manner, in the variant according to FIGS. 3 to 5, the sliding sleeve 29 can be displaced in a rotationally secured manner.

[0036] The housing part 23 is firmly connected to a housing of a reduction gear 24, which in the present case is designed as a continuously variable transmission, namely, a belt drive. The arrangement of the reduction gear 24 and the ball screw drive 20 is collectively referred to as the transmission arrangement 28. On the input side of the reduction gear 24, this is connected to the shaft of an electric motor 25, which is also a component of the actuator 9.

[0037] In order to raise the mower 5, in the case of FIGS. 1 and 2 in the electromechanical adjustment mode, the push rod 19 must be extended from the housing part 23. This inevitably means that the front lever 11 is also adjusted, which is irrelevant in this case. In order to raise the mower 5 by muscle power, the driver steps on the pedal 10, whereby both levers 11, 15 are pivoted clockwise, relative to the arrangement according to FIG. 1. Optionally, the control unit 8 displays the current setting of the mower 5. A lowering of the mower 5, which is accompanied by a retraction of the push rod 19 into the housing part 23, can be assisted or caused by gravity.

[0038] The exemplary embodiment according to FIGS. 3 to 5 differs from the embodiment according to FIGS. 1 and 2 in that the coupling element, which is present here in the form of the sliding sleeve 29, is not loaded by the actuator 9 with a compressive force, but rather with a tensile force. The stop 27, on which the coupling element 29 can be supported, is provided by an end piece 30 of the threaded spindle 21. The maximum stroke of the threaded spindle 21 is designated with H.sub.max. In the setting shown in FIG. 3, the mower 5 (not shown here) is lowered to its maximum position. While maintaining the setting of the actuator 9, the sliding sleeve 29 can be lifted from the stop 27 by actuating the pedal 10, whereby the mower 5 is raised manually. In the setting outlined in FIG. 4, barely half of the maximum stroke H.sub.max is used. Here, the coupling element 29 is loaded with a force, while the threaded spindle 21 is not subjected to any compressive or tensile force. As soon as the pedal 10 is released, the mower 5 is lowered again until the setting shown in FIG. 3 is reached again.

[0039] The setting of the linear actuator 9 shown in FIG. 5 also assumes that the mower 5 was previously completely lowered. The transition between the setting according to FIG. 3 and the setting according to FIG. 5 is possible purely by motor, i.e., with the sliding sleeve 29 permanently in contact with the stop 27. To a small extent, starting from the setting according to FIG. 5, an additional manual displacement of the sliding sleeve 29 and thus a lifting of the mower 5 is possible until the upper stop of the mower 5 is reached, in this case accompanied by a stop of the sliding sleeve 29 on the left side of the housing of the linear actuator 9.

[0040] The dependency between the manual adjustment option and the setting of the threaded spindle 21 is also evident from the diagram in FIG. 6. Here, the threaded spindle 21 is adjustable along the x-axis. The deflection of the sliding sleeve 29, i.e., the coupling element, which is clearly related to the height setting of the mower 5, is designated by A. VM indicates the adjustment range, depending on the setting of the threaded spindle 21, in which manual lifting of the mower 5 is possible. In order to cushion the lowering movement of the mower 5 after a manual lifting, cushioning elements (not shown) can be built into the manual actuation mechanism, designated overall by 26.

LIST OF REFERENCE SYMBOLS

[0041] 1 Vehicle [0042] 2 Chassis [0043] 3 Wheel [0044] 4 Wheel [0045] 5 Mower [0046] 6 Height adjustment, adjustment mechanism [0047] 7 Seat [0048] 8 Control unit [0049] 9 Linear actuator [0050] 10 Pedal [0051] 11 Lever, front [0052] 12 Center pivot point [0053] 13 Lower pivot point [0054] 14 Rod [0055] 15 Lever, rear [0056] 16 Center pivot point [0057] 17 Lower pivot point [0058] 18 Upper pivot point [0059] 19 Push rod, coupling element [0060] 20 Ball screw drive [0061] 21 Threaded spindle [0062] 22 Spindle nut [0063] 23 Housing part [0064] 24 Reduction gear [0065] 25 Motor, electric motor [0066] 26 Actuation mechanism, manual [0067] 27 Stop [0068] 28 Transmission arrangement [0069] 29 Sliding sleeve, coupling element [0070] 30 End piece [0071] A Deflection [0072] H.sub.max Maximum stroke [0073] VM Manual adjustment range [0074] x Adjustment path of the output element