Device for force simulation on an actuating element of a vehicle, preferably a pedal force simulator

Abstract

A device for force simulation on an actuating element of a vehicle, which is designed as a pedal force simulator that provides haptic feedback about a predetermined force-displacement behavior, wherein a translation-rotation unit (9, 15) connected to the actuating element (21) is designed to convert the translational movement of the actuating element (21) into a rotational movement of an energy store (12), wherein the energy store (12) reacts on the translation-rotation unit (9, 15) to generate the haptic feedback, characterized in that the translation-rotation unit has a rotary sleeve (9) that includes an adjusting element (15) that is operatively connected to the actuating element (21), wherein the rotary sleeve (9) and adjusting element (21) are each guided by a bearing (18, 19) on the helical contour (20), wherein the bearings (18, 19) roll on one another.

Description

[0001] The invention relates to a device for force simulation on an actuating element of a vehicle, preferably a pedal force simulator, which provides haptic feedback about a predetermined force-displacement behavior.

[0002] From DE 10 2011 016 239 A1, a pedal force simulator for a vehicle brake with electronic signal transmission is known, in which the braking torque is controlled depending on the foot force of the driver, in particular by means of electrohydraulic or electromechanical systems, whereby the pedal force simulator generates a braking feeling that is familiar to a driver.

[0003] DE 10 2010 061 439 A1 discloses a braking system for a motor vehicle, in which a brake pedal, which is operated by a driver, is connected to a pedal simulator for generating a travel-dependent counter- or restoring force. The position of the brake pedal is detected by a sensor, and its sensor signal is fed to a control unit for evaluation. The pedal simulator is controlled by the control unit in such a way that a restoring force acts on the brake pedal, thus establishing a travel-force relationship that gives the driver a pedal feel similar to that experienced when braking exclusively with a hydraulic brake system.

[0004] In clutch-by-wire systems, the clutch is actuated by an electric motor, which is also controlled by a clutch pedal operated by the driver. However, the driver should feel the same force-displacement curve on the pedal when engaging and disengaging the clutch as with a conventional release system. The master cylinder of the conventional release system is to be replaced by a component that generates the same force-displacement curve on the clutch pedal as the conventional release system.

[0005] From DE 10 2012 016 259 A1, a pedal force simulator according to the preamble of claim 1 is known. Further prior art is specified in DE 10 2012 005 777 A1.

[0006] The invention is based on the object of providing a device for force simulation on an actuating element of a vehicle, which device conveys the same feeling to the driver as with a conventional system and is nevertheless easy to manufacture.

[0007] According to the invention, this object is achieved in that a translation-rotation unit connected to the actuating element is designed to convert the translational movement of the actuating element into a rotational movement of an energy accumulator, wherein the energy accumulator acts back on the translation-rotation unit to generate the haptic feedback. Since the energy accumulator is elastically stressed, a force acts back on the actuating element depending on the travel of the actuating element. Advantageously, the energy accumulator is designed as a spring accumulator, preferably as a helical spring. Such a helical spring is subjected to bending stress about its axis when the translational movement is converted into a rotational movement, thereby generating the restoring force.

[0008] In one embodiment, the translation-rotation unit has a helical contour with a predetermined pitch. This helical contour converts the translational movement of the actuating element into a rotational movement, by means of which the energy storage device in the form of the helical spring is wound up, i.e., twisted.

[0009] In one embodiment, the pitch of the helical contour is discontinuous. This allows a desired force-displacement curve to be set on the device.

[0010] To achieve the same feel on the accelerator pedal as with a conventional system, the pitch of the helical contour is steeper at the beginning of the actuation travel of the actuating element than towards the end. The steeper the pitch of the helical contour, the greater the torque applied to the translation-rotation unit is converted into an axial force, which the user then perceives at the actuating element.

[0011] According to the invention, the translation-rotation unit comprises a rotary sleeve comprising an adjusting element operatively connected to the actuating element. The rotary sleeve and adjusting element are each guided by a bearing on the helical contour, with the bearings rolling on each other. This arrangement exerts a torque proportional to the torsion angle of the coil spring on the rotary sleeve.

[0012] In one embodiment, the helical contour is formed on a housing enclosing the rotating sleeve.

[0013] In a further development, each of the two rolling bearings is mounted on a pin, with one bearing rolling on the helical contour formed on the housing, while the other bearing rolling on the rotating sleeve. As a result, both bearings are initially displaced in the axial direction when the actuating element moves. The helical contour presses the first bearing radially against the second bearing, which in turn presses on the rotating sleeve, which in turn presses on the helical spring, causing it to twist.

[0014] In another embodiment, the helical contour is formed on the inside of the rotating sleeve. Since this contour extends along the rolling point of the bearing to the rotating sleeve, only the rotating sleeve rotates.

[0015] Advantageously, each of the two rolling bearings is mounted on a pin, with one bearing rolling on the helical contour positioned in the rotating sleeve, while the other bearing rolls on the housing along an axially extending track. This has the advantage of providing an anti-twist lock for the adjusting element.

[0016] The invention permits numerous embodiments. Two of them will be explained in more detail with reference to the figures shown in the drawing.

[0017] They show: Fig. 1: a schematic diagram of a clutch-by-wire clutch system of a vehicle, Fig. 2: a first embodiment of the device according to the invention, Fig. 3: a section AA through the device according to Fig. 2, Fig. 4: a section BB through the device according to Fig. 2, Fig. 5: Example of a force-displacement characteristic curve, Fig. 6: a second embodiment of the device according to the invention, Fig. 7: a section BB through the device according to Fig. 6, Fig. 8: a section AA through the device according to Fig. 6.

[0018] In Fig. Figure 1 shows a schematic diagram of a clutch system 1 in which the clutch 2 is actuated by a clutch-by-wire system. In such a system, an accelerator pedal 3, which is to be actuated by the driver, is connected to a pedal force simulator 4, on which a sensor 5 is arranged, which transmits the displacement of the pedal force simulator 4 to a control unit of an electric motor 6. The electric motor 6 controls the clutch 2 via a hydraulic path 7 depending on the change in travel measured by the sensor 5.

[0019] An embodiment of a pedal force simulator, which represents a device for force simulation on the accelerator pedal 3, is shown in Fig. 2. The pedal force simulator 4 consists of a housing 8 in which a rotating sleeve 9 is rotatably mounted by means of two bearings 10 and 11. One or more coil springs 12 are arranged in the housing 8 and are twisted between the rotating sleeve 9 and the housing 8 via a housing stop 13 and a stop 14 of the rotating sleeve 9. A torque is exerted on the rotating sleeve 9 proportional to the torsion angle of the coil spring 12. To exert this torque, an adjusting element 15 is arranged within the rotating sleeve 9, on which pins 16, 17 are supported in the axial direction. A bearing 18, 19 runs on each of the pins 16, 17, with the two bearings 18, 19 rolling on each other. The bearing 18 runs on the pin 16 and rolls on a contour 20 located on the housing 8, which runs helically within the housing 8. The bearing 19 runs on the pin 17 and rolls on the rotating sleeve 9.The adjusting element 15 is actuated by a tappet 21, which is secured against rotation by its connection to the accelerator pedal 3. If the tappet 21 is moved axially by the accelerator pedal 3, it presses on the adjusting element 15 and moves it in the axial direction. The bearings 18 and 19 are also displaced axially with the adjusting element 15. The helical contour 20 presses the bearing 18 radially against the bearing 19, which in turn presses on the rotating sleeve 9. As a result, the rotating sleeve 9 is rotated depending on the helical contour 20, whereby the rotation twists the coil springs 12.

[0020] The Fig. Section AA shown in Figure 3 shows the adjusting element 15 in the unactuated state. Fig. 4 shows a section BB showing the adjusting element 15 in a fully actuated state. Proportional to the torsion angle of the coil springs 12, a torque is generated on the rotating sleeve 9, which presses against the helical contour 20 with a radial force via the bearing 19 and the bearing 18. Since the helical contour 20 has a pitch in the axial direction, the bearing 18 experiences an axial force depending on the pitch angle and the acting radial forces, which is transmitted to the tappet 21 via the pin 16 and the adjusting element 15. The pitch of the helical contour 20, in combination with the torsional rigidity of the coil springs 12, can be used to shape the force-displacement relationship on the tappet 21.

[0021] In Fig. Figure 5 shows an example diagram of a possible force-displacement curve. With such a force-displacement curve, curve a shows the forward stroke, while curve b shows the return stroke of the actuating element, i.e., the plunger 21. A greater force occurs on curve a at the beginning of the actuating stroke when the gradient of the helical contour 20 is steeper than toward the end of the actuating stroke.

[0022] To realistically simulate the pedal force, a hysteresis between the force on the forward and return strokes should be present, dependent on the force of the plunger 21. The points primarily responsible for friction are the pivot point of the plunger 21 in the adjustment element 15, the sliding point of the adjustment element 15 in the rotary sleeve 9, and in the housing 8. Friction at these points depends on the plunger force. By appropriately selecting the friction coefficients at these points, the desired hysteresis can be created, thereby reducing the force on the return stroke.

[0023] A second embodiment of the device according to the invention is shown in Fig. 6. This differs from Fig. 2 in that the helical contour 20 is arranged inside the rotating sleeve 9. For this reason, the bearing 19 running on the pin 17 rolls on this helical contour 20 located in the rotating sleeve 9. The bearing 18 runs on the pin 16, rolling on the housing 8 on a track running axially along the housing 8 and thus providing an anti-twist device for the adjusting element 15.

[0024] If the plunger 21 is moved in the axial direction, it also presses on the adjusting element 15 and moves it in the axial direction. The bearings 18 and 19 are also displaced in the axial direction with the adjusting element 15. The helical contour 20 is supported on the anti-rotation bearing 19 and presses against the rotating sleeve 9 in the radial direction. As a result, the rotating sleeve 9 is rotated depending on the helical contour 20, and this rotation twists the coil springs 12. Section BB ( Fig. 7) shows the adjusting element 15 in the unactuated state, while in Fig. 8 shows a section AA, which shows the adjusting element 15 in the fully actuated state. Proportional to the torsion angle of the coil springs 12, a torque is generated on the rotary sleeve 9, which presses against the bearing 19 with a radial force via the helical contour 20. Since the helical contour 20 has a pitch in the axial direction, the bearing 19 experiences an axial force depending on the pitch angle and the radial force, which is transmitted via the pin 17 and the adjusting element 15 to the tappet 21. This arrangement also Fig. 5 shown force-displacement curve on the plunger 21 is set with the corresponding hysteresis.

[0025] The described solution allows, due to the helical contour 20 with a gradient designed according to the desired force-displacement curve, a translatory pedal movement to be converted into a rotary movement, by means of which the helical spring 12 is subjected to bending about its axis, whereby it acts as a spring accumulator. List of reference symbols 1 coupling system 2 clutch 3 Accelerator pedal 4 Pedal force simulator 5 Sensor 6 Electric motor 7 Hydraulic section 8 housings 9 Rotating sleeve 10 warehouses 11 camps 12 coil spring 13 Housing stop 14 Stop of the rotating sleeve 15 Adjustment element 16 pin 17 pen 18 camps 19 camps 20 Helical contour 21 plungers

Claims

[1] Device for force simulation on an actuating element of a vehicle, which is designed as a pedal force simulator which provides haptic feedback about a predetermined force-displacement behavior, wherein a translation-rotation unit (9, 15) connected to the actuating element (21) is designed to convert the translational movement of the actuating element (21) into a rotational movement of an energy store (12), wherein the energy store (12) reacts on the translation-rotation unit (9, 15) to generate the haptic feedback, characterized by that the translation-rotation unit has a rotary sleeve (9) which comprises an adjusting element (15) which is operatively connected to the actuating element (21), wherein the rotary sleeve (9) and the adjusting element (21) are each guided by a bearing (18, 19) of the helical contour (20), wherein the bearings (18, 19) roll on one another. [2] Device according to claim 1, characterized by that the energy store (12) is designed as a spring store, preferably as a helical spring. [3] Device according to claim 1 or 2, characterized by that the translation-rotation unit (9, 15) has a helical contour (20) with a predetermined pitch. [4] Device according to claim 2, characterized by that the gradient of the helical contour (20) is discontinuous. [5] Device according to claim 3, characterized by that the gradient of the helical contour (20) is steeper at the beginning of the actuating path of the actuating element (21) than towards the end of the actuating path. [6] Device according to one of the preceding claims, characterized by that the helical contour (20) is formed on a housing (8) enclosing the rotating sleeve (9). [7] Device according to one of the preceding claims, characterized by that each of the two bearings (18, 19) rolling on one another is mounted on a pin (16, 17), one bearing (18) rolling on the helical contour (20) formed on the housing (8), while the other bearing (19) rolling on the rotary sleeve (9). [8] Device according to one of the preceding claims, characterized by that the helical contour (20) is formed on the inside of the rotating sleeve (9). [9] Device according to claim 8, characterized by that each of the two bearings (18, 19) rolling on one another is mounted on a pin (16, 17), one bearing (19) rolling on the helical contour (20) positioned in the rotary sleeve (9), while the other bearing (18) rolling on the housing (8) along an axially extending path.

Images