DE4341134A1 - Motorised running board for car - Google Patents

Abstract

A motorised running board for a car is located in a frame like a chest of drawers, with at least three longitudinal bars (12) and at least two transverse bars (13) on at least four support rollers (6). In the retracted state, the drive mechanism screens it against weather effects. The running board is driven by a motor 91) with a worm gear (1) through a drive roller 92) with a multiple outer thread (31) and a cable (5) arranged in a cross pattern. The cable passes over at least two fixtures (10) on the running board and at least four rollers (3) on the longitudinal bars. The cable is wrapped around the outer thread of the drive roller.

Description

The invention relates to a motorized footboard for motor vehicles, especially for people carriers and Busses, as well as an electrical control for this.

In a number of the MPVs currently produced or buses, the entrance is approx. 40 to 60 cm above half the lane so that for children, the disabled and the elderly Getting in the car can be problematic for people.

For this reason, some of the above are driving mechanical footboards available. This through Driver function of the door operated footboards have each but the disadvantage that they have a high operating force the door opening or closing, that of the above groups of people mentioned are usually not upset can be. In addition, the operating force in winter by icing up the running board or door mechanism be elevated. This forces the driver of the above Vehicle types usually do this when transporting them People get out of the vehicle and the door to operate together with the footboard. Especially when using the motor vehicles listed above in the school bus This leads to traffic inconvenience for the driver to a great loss of time.

The commercially available motorized running boards however, have the disadvantage that their construction is maneuverable, the purchase price is high, which Space requirement too large and its functionality especially in the Winter use is not fully satisfactory.  

The invention seeks to remedy this.

The invention has for its object a motor powered footboard for motor vehicles to create the through a simple but under all weather conditions reliable construction and inexpensive is to be produced.

This object is achieved by the features of patent claims 1 and 17 solved. Advantageous embodiments of the invention are Subject of subclaims 2 to 16 and 18 to 30.

According to the invention the object is achieved in that the Running board according to the "drawer system" in a frame is held such that the entire drive mechanism in Intended use of the device according to the invention on the vehicle underbody largely before weather influences is protected.

Large-series automotive engines serve as the drive for the running board with worm gear, such as those used for disc washers shear, motorized sunroofs etc. millions of times be used in automotive engineering.

The footboard is operated using a cross guided rope using a new drive pulley, preferably with an integrated, finely adjustable Slip clutch, causing damage to the engine in the event of a possible blockage of the running board - for example by a Obstacle not noticed by the driver - safely prevented can be.

The worm gear used according to the invention enables a compact vertical design of the motor Drive, which in view of the limited installation height on Motor vehicle underbody is important. Also saved the self-locking of the worm gear mechanical Locking devices for the footboard.  

On the top facing the outside of the motor vehicle The longitudinal edge of the running board frame is sharply ground Scraper rail to prevent freezing, especially in winter of the footboard on the frame due to remaining snow or To prevent ice scraps.

Special attention was also paid to the electrical control a simple, but durable and inexpensive construction placed. So in particular in the preferred embodiment form instead of expensive small series reversing relays four Large-scale automotive relays with only one working contact each what sets apart from cost advantages also a quick repair enables in every car workshop.

Overall, the device according to the invention is distinguished a high level of operational reliability, a large variety of variations in terms of possible adaptation to everyone currently on the market relevant motor vehicle types and by an inexpensive production due to the extensive Use of large-series automotive components.

The invention will now be described with reference to the drawings explained.

It shows:

Figure 1 is a plan view of the running board according to the invention in the extended state.

Figure 2 is a section along the line II in Fig. 1.

Figure 3 shows the drive roller with integrated slip clutch in partial section.

Fig. 4, the drive roller in plan view from the counter bearing side and

Fig. 5 is a circuit diagram of the engine control.

As can be seen from FIGS. 1 and 2, a motor 1 equipped with a worm gear 1 a and a drive roller 2 is attached to the central longitudinal member 12 of the drawer-shaped frame 11 consisting of at least two further longitudinal members 12 and at least two cross members 13 . Permanently excited DC shunt motors with worm gear 1 a are preferred as motors, for example the types 403 315 or 402 826 with approx. 50 W continuous output at 12 V from SWF, Bietigheim-Bissingen, which are suitable for running boards 9 to approx 1 m width is sufficient. For larger running boards 9 , which, for example, also paint over the passenger door, a higher engine power is required, as is the case, for. B. of the type GR 63 × 55/12 V / approx. 100 W, with worm gear FG 80 from Dunker Motoren, Bonndorf.

The drive roller 2 , preferably with an integrated slip clutch, comprises a hollow cylinder with an external thread 31 , as can be seen from FIGS. 3 and 4. It is preferably made of a flame-retardant plastic with high abrasion resistance and a permanent temperature resistance of T <80 ° C, for example polyamide, polyoxymethylene, polysulfone, polyether or polyimide, or from a light metal alloy. The length of the drive roller 2 or the number of threads of the external thread 31 depends on the width of the running board 9 and on the diameter of the rope 5 .

The rope 5 is preferably made of galvanized steel of sufficient tensile strength, particularly preferably of a stainless steel, wherein it has a diameter between 2 and 4 mm, preferably 3 mm.

With a footprint of the footboard 9 of, for example, approx. 30 cm and a length of approx. 1 m, the drive roller 2 has a length of approx. 3 cm and a diameter of approx. 7 cm approx. 5 threads for a wire diameter of 3 mm on. The rope 5 is threaded from the outside through the opening 32 of the drive roller 2 into the interior thereof, guided in the cavity 34 coaxially to the laterally flattened hub in the inner groove 36 of the drive roller 2 , guided outwards through an opening 33 and wound onto the external thread 31 in such a way that it unwinds and unwinds on the drive roller 2 at the same time when extending or retracting the footboard 9 .

The self-locking property of the worm gear 1 a prevents the rope 5 from winding up or unwinding automatically from the drive roller 2 when the motor 1 is not actuated, thereby unintentionally extending or retracting the running board 9 so that additional mechanical locking is provided of the running board 9 can be dispensed with.

As can be seen from FIGS . 3 and 4, the in the drive roller 2 preferably integrated slip clutch comprises a coaxially flattened hub 21 in the form of a hollow cylinder made of steel, brass or a light metal alloy, which is releasably attached to the gear shaft 30 by means of a grub screw 29 is. The hub 21 has at its end opposite the gear shaft 30 a fine external thread 35 onto which an adjusting nut, preferably a lock nut 25 , is screwed for the purpose of fastening the drive roller 2 . A counter bearing support 28 which is fastened to the central longitudinal beam 12 and is equipped with a receiving pin 27 and a ball bearing 26 serves as the preferably provided counter bearing for the hub 1 . To the transmission 1 a facing end of the hub 21 an annular friction plate 22 is placed, the driving roller 2 is then pushed, followed by a further friction disc 23 and an annular spring washer 24th By actuating the lock nut 25 with a defined torque by means of a torque wrench, the response of the slip clutch can be set exactly.

As can be seen from Fig. 1, the drive of the footboard 9 takes place on the intersecting on the drive roller 2 rope 5 , the ball-bearing plastic order to 3 castors 3 (at least 40, preferably six attached to the outer side members 12 ) (diameter about 40th mm) is performed. Here, a rope tensioner 4 , preferably in the form of a Spannfe, serves to tighten the rope 5th

The stored at least four attached to the frame 11 carrying rollers 6 footboard 9 is off by the moving rope 5 by means of at least two attached to the inner longitudinal edges of the footboard 9 driver 10 from the frame 11 or retracted. The drivers 10 are preferably made of galvanized flat steel and provided with a central groove, the diameter of the central groove being matched to the diameter of the cable 5 .

One on the intended use for vehicle exterior side send wei cross member 13 of the frame 11 mounted above the footboard 9 wiper blade 8 has a sharp side cut on the pointing to the footboard 9 edge. This scraper rail 8 is used to remove any dirt or snow residues remaining on the top of the running board 9 when driving the running board 9 in order to prevent the same from sticking or freezing to the frame 11 .

The drawer-shaped frame 11 composed of at least three side members 12 and at least two cross members 13 , preferably made of galvanized square steel tube or flat iron, is matched to the particular vehicle type in such a way that when the running board 9 is completely retracted, all of the mechanics and electrics in the frame 11 are largely is protected from the weather. This results in a considerable increase in the service life of the components in question.

Preferably for use in all-terrain vehicles, the frame 11 or the running board 9 is such elements with Dichtele, z. B. rubber sealing strips, to equip that the frame 11 is completely sealed against splash water all around when the running board 9 is fully retracted when used as intended.

The footboard 9 is preferably made of a circumferential frame made of galvanized double-T steel profile, on which tread plate is preferably attached as a tread surface, in order to ensure sufficient slip resistance even under unfavorable weather conditions. In order to limit the total mass of the running board 9 , a high-strength aluminum alloy is preferably chosen as the material for the tread surface. The material thicknesses for running board 9 and frame 11 depend in particular on the dimensions of the running board. In order to avoid jamming of the running board even under maximum load, the extendable depth of the tread surface of the running board 9 is kept at approximately half the installation depth of the frame 11 , which is generally approximately 40 to 50 cm. The at least two mounting brackets 7 are to be designed individually for the respective vehicle type in order to allow the frame 11 to be attached to the cross member or beads on the underbody of the vehicle in the region of the side sliding or passenger door concerned.

As can be seen from FIG. 5, the electrical control for the engine 1 essentially comprises an actuating switch 102 to be fitted in the dashboard of the motor vehicle with two switch positions (footboard exit or entrance), an inner limit switch 103 , an outer limit switch 104 , a reversing device for the motor 1 , a microfuse 101 between the actuating switch 102 and the positive pole of the motor vehicle battery 100 and a power fuse 110 between the positive pole of the battery 100 and the reversing device.

As a reversing device for reversing the direction of rotation of the motor 1 for the entry or exit of the footboard 9 , a so-called electromagnetic reversing relay with at least two changeover contacts, two relays with at least two normally open contacts or four relays with at least one normally open contact are in question, whereby for the latter case, in principle, alternatively, semiconductor load relays can also be used.

Obviously, due to a lack of relevant demand, electromagnetic relays with several contacts for 12 V DC are not currently being mass-produced, so that for reasons of spare parts supply and the price, four large-scale automotive relays 106 to 109 , each with one working contact, with one on the starting or Continuous current of the motor 1 coordinated load capacity are preferably used.

In order to avoid premature wear of the relay contacts, the motor 1, for example, an RC element comprising a capacitor 111 and a resistor 112 must be connected in parallel. For an engine output of, for example 50 W at 12 V DC voltage has a capacity of approximately 5 to 15 microfarads is to be provided at a voltage strength of at least about 200 V alternating voltage for the capacitor 111 while the resistor 112 is preferably a value between about 5 and 15 Ω / 10 W is to be selected. As an alternative or in addition to the RC element, a surge arrester 113 , for example a varistor or a gas discharge element, can be connected in parallel to the motor 1 , in the latter case the nominal voltage of the capacitor 111 (and thus its volume and price) corresponding to the breakdown voltage of the surge arrester 113 can be reduced.

When using a motor 1 with a nominal power <100 W, inrush currents of <50 A occur, which can lead to a heavy load on the relay contacts and thus to a significant reduction in their service life. In this case, it is particularly recommended to limit the inrush current to the motor 1 an inrush current limiter 117 , preferably a starting thermistor with, for example, a cold resistance (25 ° C) of approx. 1 to 5 Ω, a hot resistor (at approx. 125 ° C) <0.05 Ω and a nominal current adapted to the nominal current of the relevant motor type.

The relays 106 to 109 and the motor wiring 110 to 113 are preferably combined on a circuit board and expediently mounted in the vicinity of the motor 1 in order to keep the voltage drop on the supply lines as low as possible.

A rocker switch with a neutral center position is preferably used as the actuating switch 102 , the two switching states of which are preferably indicated by two indicator lights 105 a and b (light bulbs or LEDs with a series resistor), which can also be integrated in the switch 102 .

If, in a preferred embodiment, the positive poles of the indicator lights 105 a, b are each connected directly to the connection terminals of the motor 1 , they can additionally display the proper function of the relays 106 to 109 .

In parallel to the switch 102 , a key switch 116 , which is attached to the outside of the vehicle and is directly connected to the fuse 110 , can be switched to permit actuation of the footboard 9 even without first climbing onto the motor vehicle.

As limit switches (limit switches) 103 and 104 , NC contacts are preferably used in miniature design with a low current carrying capacity (approx. 1 A at 12 V DC voltage), since they only have to be designed for the coil current of relays 106 to 109 . As can be seen from Fig. 1, the inner limit switch 103 is attached to an inside of a side member 12 of the frame 11 such that it is operated by the footboard 9 straight when it is in the "fully retracted" status.

In a preferred embodiment, the inner limit switch 103 has a further break contact or a further limit switch 114 of the break type is provided at the location of the limit switch 103 , which has a step board status indicator 115 to be fitted in the dashboard, which is connected directly to one pole the fuse 101 is connected, ver binds to ground as long as the footboard 9 is not in the "fully retracted" status.

Alternatively, a running board status detector 115 with an operating current which is below the response current of the relays 106 , 107 , for example a light-emitting diode (LED) with a series resistor (typical operating current 20 mA), can be connected in parallel with the actuating switch 102 between the miniature fuse 101 and the inner one Limit switches 103 are switched (as shown in dashed lines in FIG. 5), whereby an additional contact in the limit switch 103 or the additional limit switch 114 is unnecessary.

As running board status indicator 115 indicator lights, preferably with a flashing function for increased attention, or beepers are used to prevent the motor vehicle from moving before the running board 9 is fully retracted.

The outer limit switch 104 is placed on the frame 11 that it is actuated by the footboard 9 just when it is in the "fully extended" status.

For the miniature fuse 101, via the switch 102 to connect to the Zündklemme 15 of the vehicle front preferably, ranges from a type <5 A, while the power backup is to be interpreted to the nominal motor current 110th

The mode of operation of the electrical drive control is explained in more detail with reference to FIGS . 1 and 5.

Extend the footboard

When the "extended position" of the switches 102 or 116 is actuated, a control current flows to the ground via the limit switch 104 , which is always closed when the running board 9 is not fully extended, via the coils of the "extended relay" 108 and 109 connected in parallel. After the working contacts of the same have been closed in this way, the motor 1 is connected directly to the battery 100 via the fuse 110 . The motor 1 then begins to extend the footboard 9 , which brings the inner limit switch 103 into the “closed” state. When the switch 102 is held in the extended position, the motor 1 moves the footboard 9 outward until the outer limit switch 104 is opened, whereupon the motor 1 is switched off by the relays 108 and 109 .

Retracting the running board 9

When the "retracted position" of the switch 102 is actuated, a control current flows via the limit switch 103 , which is always closed when the running board 9 is not fully retracted, via the coils of the "retracting relays" 106 and 107 . After the resulting closing of the working contacts of the same, the motor 1 is reversed, and the footboard 9 is retracted until the inner limit switch 103 is actuated by the fully retracted footboard 9 , whereby the motor 1 is switched off by the relays 106 and 107 . The preferably provided running board status indicator 115 reminds the driver to retract the running board 9 completely before the motor vehicle is shut down.

When the motor 1 is switched off , voltage peaks occur which can reach several 100 volts in the 12 V direct voltage operation and which, particularly when the motor 1 is reversed from full running (without a previous standstill), can assume considerably high values, which can damage the motor winding insulation, premature erosion of the relay contacts and high-frequency interference could result. These undesirable effects can be avoided by the RC element 111 , 112 , preferably in connection with the surge arrester 113 . Here, it is harmless that the motor 1 still runs after a fraction of a second due to the residual current circulating through the RC element 111 , 112 and the motor winding, since the slip clutch integrated in the drive roller 2 responds occasionally. Thanks to these measures, a complex motor brake and complex motor control with time locks (forced breaks) between motor feed and return can be avoided.

Reference list

1 = motor
1 a = worm gear
2 = drive roller
3 = pulley
4 = rope tensioner
5 = rope
6 = idler
7 = holder
8 = scraper rail
9 = running board
10 = driver
11 = frame
12 = side member
13 = cross member
21 = hub
22 = friction disc
23 = friction disc
24 = spring washer
25 = adjusting nut
26 = ball bearing
27 = locating pin
28 = counter bearing bracket
29 = grub screw
30 = gear shaft
31 = external thread of the drive roller
32 = opening for rope
33 = opening for rope
34 = cavity
35 = external thread of the hub
36 = inner groove of the drive roller
100 = accumulator
101 = microfuse
102 = operating switch
103 = inner limit switch
104 = outer limit switch
105 a, b = indicator lights
106 = relay
107 = relay
108 = relay
109 = relay
110 = performance assurance
111 = capacitor
112 = resistance
113 = surge arrester
114 = limit switch
115 = running board status indicator
116 = key switch
117 = Inrush current limiter

Claims (30)

1. Motorized footboard for motor vehicles, characterized in that

• - The running board ( 9 ) in a drawer-shaped, at least three longitudinal members ( 12 ) and at least two cross members ( 13 ) comprising frame ( 11 ) on at least four support rollers ( 6 ) is mounted such that the drive mechanism of the same largely protects against weather influences when retracted shields;
• - The running board ( 9 ) from a gear with a worm gear ( 1 a) equipped motor ( 1 ) with a multi-thread ( 31 ) provided on drive pulley ( 2 ) by means of a cross-guided rope ( 5 ) over at least two on the running board ( 9 ) attached driver ( 10 ) is driven; in which
• - The rope ( 5 ) is guided over at least four deflection rollers ( 3 ) attached to the side members ( 12 ); and where
• - The rope ( 5 ) on the external thread ( 31 ) of the drive roller ( 2 ) is wound such that it simultaneously winds up and unwinds from the drive roller ( 2 ) when the running board ( 9 ) is extended or retracted.

2. Motorized footboard according to claim 1, characterized in that the drive roller ( 2 ) comprises an integrated slip clutch with at least the following components:

• - A hub ( 21 ) in the form of a coaxially flattened hollow cylinder, which is releasably attached at one end by means of a grub screw ( 29 ) to the shaft ( 30 ) of the gearbox ( 1 a) and at the opposite end a fine external thread ( 35 ) for an adjusting nut ( 25 ) which serves to secure the drive roller ( 2 ) plugged onto the hub ( 21 ) and to adjust the slip clutch;
• - At least one friction disc ( 22 ) between the hub ( 21 ) and the drive roller ( 2 ) and at least one friction disc ( 23 ) between the drive roller ( 2 ) and the adjusting nut ( 25 ); such as
• - At least one spring washer ( 24 ) between the friction washer ( 23 ) and the adjusting nut ( 25 ).

3. Motorized footboard according to claim 1 or 2, characterized in that the drive roller ( 2 ) is made of a light metal alloy or a flame-retardant plastic with high abrasion resistance and a permanent temperature resistance <80 ° C. 4. Motorized footboard according to one of claims 1 to 3, characterized in that the drive roller ( 2 ) consists of a polyamide, a polyoxyme, a polysulfone, a polyether or a polyimide. 5. Motorized running board according to one of claims 1 to 4, characterized in that the drive roller ( 2 ) on its radial peripheral surface near its opposite axial ends has two openings ( 32 , 33 ) with one of the diameter of the rope ( 5 ) has an adapted diameter, through which the cable ( 5 ) is inserted or exported into the coaxial cavity ( 34 ) between the same and the hub ( 21 ) for the purpose of winding up on the drive roller ( 2 ), the cable ( 5 ) is wound on the external thread ( 31 ) of the drive roller ( 2 ) in such a way that when the motor ( 1 ) is actuated, irrespective of the direction of rotation, it simultaneously winds up and unwinds from the drive roller ( 2 ). 6. Motor-driven running board according to one of claims 1 to 5, characterized in that the hub ( 21 ) is mounted in a counter bearing Ge, which consists of a counter bearing bracket ( 28 ), a receiving pin ( 27 ) and a ball bearing ( 26 ) . 7. Motorized footboard according to one of claims 1 to 6, characterized in that the rope ( 5 ) consists of steel and has a diameter of at least 3 mm. 8. Motorized footboard according to one of claims 1 to 7, characterized in that the rope ( 5 ) is provided with a rope tensioner ( 4 ). 9. Motorized footboard according to claim 8, characterized in that the cable tensioner ( 4 ) consists of a tension spring with a sufficient to tighten the rope ( 5 ) sufficient spring constant. 10. Motorized running board according to one of claims 1 to 9, characterized in that the frame ( 11 ) above the running board ( 9 ) on that cross member ( 13 ), which shows the intended use to the outside of the vehicle, a scraper rail ( 8 ) which has a sharp cut on one side on the edge pointing towards the running board ( 9 ). 11. Motorized running board according to one of claims 1 to 10, characterized in that the tread on the running board ( 9 ) is made of checker plate. 12. Motorized running board according to one of claims 1 to 11, characterized in that the tread surface of the running board ( 9 ) consists of a high-strength aluminum alloy. 13. Motorized running board according to one of claims 1 to 12, characterized in that the frame ( 11 ) is equipped with sealing elements such that the running board drive parts ( 1 , 1 a, 2 , 3 , 4 , 5 , 6 , 10 ) are splash-proof when the running board ( 9 ) is fully retracted when used as intended on the vehicle underbody. 14. Motorized running board according to one of claims 1 to 13, characterized in that the mounting brackets ( 7 ) are attached and designed in such a way on the frame ( 11 ) that they permit the attachment of the frame ( 11 ) to the underbody of the respective motor vehicle . 15. Motorized footboard according to one of claims 1 to 14, characterized in that the participants ( 10 ) are made of flat iron with a central groove, the diameter of the central groove being matched to the diameter of the rope ( 5 ). 16. A motorized running board according to one of claims 1 to 15, characterized in that ball-bearing rollers made of a plastic with high abrasion resistance are used as steering rollers ( 3 ). 17. Electrical control for the motorized footboard according to one of claims 1 to 16, characterized in that it comprises at least the following components:

• - An actuation switch ( 102 ) with two working contacts;
• - an inner limit switch ( 103 ) with at least one break contact;
• - an outer limit switch ( 104 ) with break contact;
• - A reversing device for the motor ( 1 );
• - A microfuse ( 101 ) between the actuating switch ( 102 ) and the positive pole of the motor vehicle battery ( 100 ); such as
• - A power fuse ( 110 ) between the positive pole of the battery ( 100 ) and the reversing device.

18. Electrical control according to claim 17, characterized records that the reversing device from a rever sierrelais with at least two changeover contacts. 19. Electrical control according to claim 17, characterized records that the reversing device with two relays there are at least two working contacts.   20. Electrical control according to claim 17, characterized in that the reversing device consists of four relays ( 106 to 109 ), each with at least one normally open contact. 21. Electrical control according to claim 17, characterized records that the reversing device from four electro African load relay. 22. Electrical control according to one of claims 17 to 21, characterized in that two indicator lights ( 105 a, b) for the operating states "extend footboard" or "retract footboard" are provided. 23. Electrical control according to one of claims 17 to 22, characterized in that the inner limit switch ( 103 ) has a further break contact, or a further limit switch ( 114 ) is provided at the same location as the limit switch ( 103 ) around a footboard -Activate status indicator ( 115 ) as long as the running board ( 9 ) is not in the "fully retracted" status. 24. Electrical control according to one of claims 17 to 22, characterized in that the one connection of the running board status detector ( 115 ) with the supply switch ( 102 ) connected to the connecting terminal of the inner limit switch ( 103 ) and with the other connection to the Miniature fuse ( 101 ) is connected, the operating current of the status indicator ( 115 ) being selected such that the current flowing through the reversing device via the inner limit switch ( 103 ) generates a voltage drop which is below the response voltage of the reversing device. 25. Electrical control according to claim 23 or 24, characterized in that the running board status indicator ( 115 ) comprises a light-emitting diode (LED) with a series resistor. 26. Electrical control according to one of claims 23 to 25, characterized in that the running board status indicator ( 115 ) comprises a flashing function. 27. Electrical control according to one of claims 23 to 26, characterized in that the running board status indicator ( 115 ) comprises a signal tone generator. 28. Electrical control according to one of claims 17 to 27, characterized in that the motor ( 1 ) has an RC element ( 111 , 112 ) and / or a surge arrester ( 113 ) connected in parallel. 29. Electrical control according to one of claims 17 to 28, characterized in that the motor ( 1 ) is preceded by a switching current limiter ( 117 ). 30. Electrical control according to one of claims 17 to 29, characterized in that the actuating switch ( 102 ) is connected in parallel to a key switch to be attached to the motor vehicle outside ( 116 ), the positive pole of which is connected directly to the power fuse ( 110 ).