DE2758956A1 - DEVICE FOR CONTROLLING THE DRAWING FORCE OF A MOTOR VEHICLE - Google Patents

Description

on.-iNn. αιη..Ίη) 3.Μ. «ε. oia-phvs. d ». pi «..- ph» s.

HÖGER - LEGAL RIGHT - GRiESSEACH - HAECKER

PiTENTANWiITS it * SIUTIO »«!

A 42 689 a Applicant: Company Aspro, Inc.

u - 163 Westport, Conn. Ο688Ο

December 27, 1977 USA

description

Device for controlling the traction of a motor vehicle

The invention relates to a device for controlling the traction of a motor vehicle with a chassis frame, with at least one pair of driven, interconnected via a differential and on opposite sides of the Chassis frame arranged wheels, which are connected to the chassis frame, whereby this chassis frame above a fixed surface is held, with the driven wheels associated brakes, with at least two speed sensors for generating an electrical voltage signal that is dependent on the respective speed of the driven wheels and with a comparison circuit which supplies a control signal as soon as one voltage signal has increased the other by a predetermined value Exceeds the value if a driven wheel rotates faster than by an amount corresponding to the specified value the other, the electrical control signal actuating the brake assigned to the faster rotating wheel, with one with the An auxiliary axle connected to the chassis frame and carrying a pair of non-driven auxiliary axle wheels arranged in such a way that that they touch the solid surface on opposite sides of the chassis frame next to the driven wheels, with between the chassis frame on the one hand and the wheels on the other hand arranged pressure medium-actuated lifting elements and with

909819/0522

A 42 689 m

U - 163 γη

December 27, 1977 - 6 - £ f

Means for controlling the pressure medium pressure in the lifting elements, which are activated by the control signal simultaneously with the actuation the brake assigned to the faster rotating wheel can be actuated in such a way that more vehicle weight is transferred to the driven Wheels is shifted.

It is known to provide braking systems for vehicles that have a Automatically brake the driven wheel if it rotates a predetermined amount faster than the one with it Differentially connected opposite driven wheel. In this regard, reference is made to U.S. Patents 3,025,722 (Eger et al), 3,253,672 (Mikina), 3,169,595 and 3,238,232 (Shepherd) and U.S. patent application no. 600.505 (Eddy) referenced that of the German patent application P 25 43 905.8 - 21 corresponds.

It is also known to provide motor vehicles with non-powered, attached auxiliary axle systems with which the vehicle weight on and off the driven wheels, such as in the US patents 3,494,632 (Bostrom), 3,499,663 (Hedlund et al), 3,713,663 (Granning), 3,771,812 (Pierce et al), and 3,877,715 (Mayer et al) is described. It is also known to provide devices for the weight of the vehicle between driven double axles to relocate, as can be seen from U.S. Patents 2,952,326 (Page), 3,366,399 (Hunzer) and 3,920,283 (Strader). By doing last-mentioned patent (Strader) sensors are provided for the deceleration of a vehicle, which actuate an anti-lock braking system and also supply an air suspension device with air to put the weight of the vehicle on the rear pair of wheels

909819/0522

A 42 689 m

^u - 163 2758356

December 27, 1977 - 7 -

driven double axle to shift, with the on the rear Wheels acting, downward force counteracts the upward force as a result of braking generated torque acts on the rear axle. This prevents the wheels from jumping and increases the effectiveness braking increases.

As in the main application, the object of the invention is to provide an improved device for controlling the tensile force of a To create a motor vehicle in order to prevent one of the driven wheels from moving much faster when accelerating rotates than the other that is connected to it via a differential. Such a faster rotation of a wheel gives e.g. when this wheel is on a smooth surface, e.g. on ice, and spins when accelerating.

This task is achieved according to the main patent (patent application P 26 48 081.9-21) by the one described at the beginning Device for controlling the tensile force of a motor frame solved.

It is now proposed that this device of the main patent be advantageously designed in that the lifting elements are arranged between the driven wheels and the chassis frame and that the means for controlling the pressure medium pressure in the lifting elements supply them with little pressure medium during normal operation, so that part of the vehicle weight is shifted from the driven wheels to the auxiliary axle wheels, while this means the pressure of the pressure medium in the Increase screw jacks when a control signal occurs.

909819/0522

A 42 689 m

December 27, 1977 - 8 -

Advantageous refinements of the device according to the invention are the subject matter of the subclaims and are laid down in them.

In the device according to the invention, one or more hydraulic-operated lifting elements, which can change the distance between the driven wheels from the chassis frame, are normally under a low pressure of a pressure medium, so that part of the vehicle's weight rests on the auxiliary axle wheels. The comparison circuit actuates an electrically operated two-position control valve when the two opposite driven wheels have a difference in rotational speed that exceeds a predetermined value, and thus transports pressure medium to the lifting elements; this lowers the driven wheels, shifting vehicle weight back onto the driven wheels. At the same time, the brake assigned to the faster rotating wheel is actuated. By automatically shifting the weight of the vehicle to the driven wheels and by braking the faster wheel , the vehicle receives sufficient pulling force to move itself away from the position that caused the faster rotation of the one driven wheel.

According to a preferred embodiment of the invention are the lifting elements designed as bellows.

The following description of preferred embodiments the invention is used in connection with the drawing for a more detailed explanation. Show it:

90 S819 / 052?

A 42 689 a

27 December 1977 - 9 -

1 shows a schematic side view of a motor vehicle provided with an auxiliary axle;

Figure 2 is a schematic representation of a traction control system;

Fig. 3 is a circuit diagram of the comparison circuit of the device shown in Fig. 2;

FIG. 4 is a schematic view of a motor vehicle similar to FIG. 1 with a driven double axle; FIG.

5 shows a view similar to FIG. 1 of a motor vehicle with a traction control according to the invention;

6 shows a view similar to FIG. 2 for the tensile force control according to the invention and

FIG. 7 is a partial view similar to FIG. 5 of a modified motor vehicle.

1 to 4 will first be described in the main patent (Patent application P 26 48 081.9-21) described device explained.

- 10 -

909819/0522

December 27, 1977 - 10 -

In Fig. 1 a motor vehicle 2 is shown, for example a heavy truck with a chassis frame 2a. It has a couple for Steering of the vehicle steerable front wheels 4 and a pair of rear wheels 6a and 6b driven by a motor 8 (Fig. 2). Of the Drive takes place via a known differential 10. The axle parts assigned to the driven wheels 6a, 6b are connected to the chassis frame in the usual way via leaf springs 12. The vehicle also has a drag axle device or support or auxiliary axle device with a pair of non-driven drag or auxiliary axle wheels 16 which are rotatably connected to a towing or auxiliary axle 18. The drag axle 18 is on a drag or auxiliary axle holder 20 mounted, the front end of which is pivotably articulated on an extension 2b of the chassis frame 2a by means of a pin 22 is. As a result, the holder 20 is pivotable in the vertical direction about the axis of the pin 22, wherein the Drag axle 18 and the non-driven drag axle wheels 16 are raised or lowered relative to the chassis frame 2a. Between the pivotable holder 20 and the chassis frame 2a there are hydraulic-actuated lifting elements in the form of a pair arranged by bellows 24a and 24b, which pivot the holder 20 and thereby the drag axle 18 and the drag axle wheels 16 can raise or lower relative to the chassis frame 2.

IViG shown in Fig. 2, the bellows members 24a and 24b Pressure medium normally from a pressure medium source 26 via a pressure supply or pressure valve 28, a control valve 30, a regulator 32, a solenoid-operated two-position control valve 34, a quick-release valve 36 and branch lines 33a and 38b supplied. Each of the driven wheels 6a and 6b is assigned a brake 40a or 40b, which is controlled by a

- 11 -

909819/0522

U - I DJ

December 27, 1977 - 11 -

foot-operated control device 42 are operable. The control device 42 is connected between the brakes 40a and 40b and the pressure medium source 26.

As in the above-mentioned patent application P 25 43 905.8-21, each of the driven wheels is assigned a sensor 46a or 46b comprising a conventional magnetic measuring head 48a or 48b, which generates an electrical voltage signal dependent on the speed of rotation of the wheel and is sent to the input terminals of a comparison circuit 50 supplies. Two of the output terminals of the comparison circuit 50 are connected to the brake actuators 52a and 52b associated with the brakes 40a and 40b, while a third output terminal of the comparison circuit is connected to the coil of the solenoid-operated control valve 34. When this control valve is in the rest position shown in FIG. 2, pressure medium is supplied from the pressure medium source 26 via the quick-release valve 36 to the bellows elements 24a and 24b. If, on the other hand, current flows through the control valve 34, the pressure medium source 26 is separated from the bellows elements 24a and 24b; At the same time, the bellows elements are ventilated to the atmosphere via the branch lines 38a and 38b, the quick-release valve 36 and the control valve 34. As shown in FIG. 2, the driven wheels 6a and 6b can be assigned additional, coaxially arranged, likewise driven wheels 6a ¹ and 6b ¹ . In the same way, additional, non-driven wheels 16 can also be assigned to the non-driven trailing axle wheels 16. The brake actuation members 52a and 52b can consist of any suitable device, for example a spring-braking device as described in the above-mentioned patent application P 25 43 905.8-21.

- 12 -

909819/0522

December 27, 1977 - 12 -

Referring to Fig. 3, the comparison circuit explained. The signal voltages of the measuring heads 48a and 48b, which determine the speed, are sinusoidal Signal voltages that are fed to the inputs of square-wave amplifiers 64 and 66. These convert the sine waves into Square waves around. The signal voltages then pass through pulse shape amplifiers 68 and 70, which generate pulses of equal width, wherein the number of pulses corresponds to the speed of rotation of the corresponding driven wheels. The exit of each of the Pulse shape amplifier is connected to the input of a pair of integration amplifiers 72 and 74, which form part of a differential circuit which detects the speed difference between the wheels are. The increasing DC signals from the integration amplifiers are fed to the input of a pair of comparators 76 and 78 supplied. Each of the two comparators is used to determine the voltage value in such a way that when exceed a predetermined difference value the assigned Output stages 80 and 82 are activated, the corresponding brake actuators 52a and 52b being actuated will. The regulated voltage source 84 supplies the comparison circuit 50. The coil of the control valve 34 becomes simultaneously energized with the actuation of one of the actuators 52a and 52b. Therefore, if one of the brake actuators 52a and 52b is actuated to brake the faster rotating wheel, if this is much faster than the corresponding one When the opposite wheel rotates, the electrically operated control valve 34 has current flowing through it at the same time, see above that the bellows elements 24a and 24b are ventilated. As a result, the weight of the vehicle is shifted to the driven wheels 6a and 6b.

The lifting elements, in particular the bellows elements, have a fill-empty characteristic that enables rapid emptying and a slow

909819/0522 - 13 -

A 42 689 m

u - 163

December 27, 1977 - 13 -

Filling the lifting element with pressure medium guaranteed. This is achieved, for example, in that the cross section of the branch lines 38a and 38b is larger than the cross section of the rest of the pressure medium source connecting the lifting elements Cables. For example, the branch lines 38a and 38b can be made from 3/8-inch (0.95 cm) pipe and the remaining portions of the Fluid line consist of 1/4-inch (0.64 cm) pipes.

Operating mode

When the vehicle is normally traveling in a straight line, the electrically operated control valve 34 is at rest; included the pressure medium source 26 supplies the lifting elements 24a and 24b via the pressure valve 28, the control valve 30, the regulator 32, the electrically operated control valve 34, the quick release valve 36 and the branch lines 38a and 38b with pressure medium. The vehicle can by operating the brake control device be braked, which simultaneously actuates the brakes 40a and 40b, whereby the driven wheels 6a and 6b on both sides of the vehicle are braked simultaneously. As the bellows elements 24a and 24b are supplied with pressure medium in this normal state, the drag axle holders are pivoted downwards. The trailing axle 18 and the trailing axle wheels 16 are lowered relative to the chassis frame 2a, whereby a certain Part of the vehicle weight is shifted from the driven wheels 6a, 6b to the drag axle wheels 16. If that If the vehicle drives through a normal curve, the wheels on the one hand become somewhat faster because of the differential 10 revolve than the wheels on the other side of the vehicle, but because of the difference in the rotational speeds of those on the opposite side Side of the vehicle arranged wheels does not exceed a certain predetermined value, the comparison circuit not activated. Consequently, the electrically actuatable control valve 34 remains in the rest state, and the brake actuators 52a and 52b are not put into operation.

- 14 -

909819/0522

A 42 689 m

ΠΙ 1977 -, 4 -

If the driven wheels 6a and 6a ¹ on one side of the vehicle rotate faster than the wheels 6b and 6b 'on the other side of the vehicle, as can happen, for example, when the wheels 6a and 6a ¹ are on an icy surface and therefore can transmit little tensile force, the voltage signal supplied by the sensor 46a becomes larger than the voltage signal supplied by the sensor 46b by a predetermined value. The output stage 80 of the comparison circuit 50 is thereby switched through, whereby at the same time the brake actuator 52a is put into operation, which ensures ^{braking of the faster rotating wheels 6a and 6a 1;} furthermore, the coil of the control valve 34 is energized, whereby the bellows elements 24a and 24b are vented to the atmosphere. As a result, the drag axle holder 20 can pivot upwards (in FIG. 1, for example, in a counterclockwise direction), as a result of which the vehicle weight is shifted onto the driven wheels 6. As a result of the increased weight resting on the driven wheels 6 and as a result of the braking of the faster rotating wheels 6a and 6a ', sufficient tractive force is transmitted to the driven wheels 6b and 6b' so that they can move the vehicle away from the icy surface. When the difference in the rotational speeds of the opposite driven wheels no longer exceeds a predetermined value, the comparison circuit is deactivated again, whereby the brake actuator 52a is simultaneously put out of operation and the electrically operated control valve 34 is de-energized so that it returns to the rest position. As a result, the lifting elements 24a and 24b are again supplied with pressure medium, so that part of the vehicle weight is shifted back from the driven wheels 6 to the drag axle wheels 16. Since the branch lines 38a and 38b have a larger cross-section than the other parts of the pressure medium line system, the filling of the two elements with pressure medium will take place more slowly than the release of the pressure medium from the two elements into the atmosphere as soon as the control valve 34

- 15 -

909819/0522

A 42 689 m

u - 163

December 27, 1977 -15-

is excited.

With reference to FIG. 4, it is pointed out that the device shown in FIGS. 1 to 3 and described above can also be used for a vehicle 102 with a chassis frame 102a with a double axle. The two axes are on one Axle holder 112 is stored, wheels 106 and 166 are over a conventional double-axle differential, not shown in the figure, is driven. Behind the double axle is in In exactly the same way as described in the previous exemplary embodiment, a trailing axle device 114 is arranged. This comprises a drag axle holder which is pivotably articulated on the vehicle chassis 102a by means of a pin 122 and which is connected by means of of two lifting elements 124a and 124b is pivotable, so that a drag axle 118 carrying drag axle wheels 116 is spaced apart is adjustable from the chassis frame 102a. Otherwise, the control device of the vehicle 102 is constructed in the same way as the control device described above in connection with the vehicle of FIG.

Here, too, the drag axle device 114 is actuated automatically and thereby shifts the vehicle weight to the driven wheels 106 and 166 as soon as the wheels 106 are at the rear Axle and the wheels 166 on the front axle and / or as soon as the wheels on opposite sides of the vehicle are different circulate quickly. As described above, this activates the comparison circuit that decelerates the faster rotating wheels and at the same time a ventilation of the lifting elements 124a and 124b of the drag axle device worried.

- 16 -

909819/0522

A 42 689 m

^u - ¹⁶³ 27589S6

December 27, 1977 - 16 -

Although the device based on a motor vehicle with pneumatic Brake system has been described, it can of course also be used in vehicles with hydraulic, electromechanical or another type of braking system can be used. Furthermore, it is not only applicable to motor vehicles with a tag axle device, i.e. usable with non-driven, liftable wheels, but also on vehicles with a so-called "Pushers", or auxiliary propellers, such as those described in Granning Suspensions, Inc. Bulletin 500 AP-571 are described. For this reason, in the context of the present application, the term auxiliary axis is generally used, if the drag axis or the axis of the "slide" is meant.

With reference to FIGS. 5 to 7, a device for controlling the tractive force of a motor vehicle according to FIG Invention described. This device is constructed in many parts the same as the device described so far, for those under the main patent

(Patent application P 26 48 081.9-21) Protection is sought. The same parts therefore have the same reference numerals as those in FIGS Fig. 1 to 3 shown device, which is preceded by a 2 or a 3 to differentiate.

In contrast to the embodiment described in FIGS is in the device shown in Figs. 5 and 6, the axis of the driven wheels 206 with the axis of the auxiliary wheels are connected via a compensating element 280, the middle part of which is connected to the vehicle frame 202 via springs 282 is. In this embodiment, the lifting element is 224

- 17 -

90 9 819/0522

^{A 42 689 m} 07 CQQ CC

u - 163 2/58956

December 27, 1977 - 17 -

arranged between the axle pieces of the driven wheels 206 and the vehicle frame. Here can be seen from Fig. 6, stand the bellows 224a and 224b in normal operation via the electrically operated valve 234 in communication with the atmosphere. If one of the driven wheels rotates a fixed amount faster than the other, then the actuates Comparison circuit 250 at the same time the brake assigned to the faster rotating driven wheel and the valve 234. This is pushed into the pressure position, in which the pressure medium from the pressure medium source 226 to the bellows 224a and 224b is transported. This transfers the load of the vehicle from the auxiliary wheels to the driven wheels relocated. As soon as the faster rotating wheel engages again, the comparison circuit releases the brake again and de-excites it Valve 234, whereby the bellows are vented to the atmosphere. The vehicle load then rests again on both the driven wheels as well as on the auxiliary wheels.

In the embodiment shown in Fig. 7, the driven Wheels 306 and auxiliary wheels 316 are independent of one another Connected to the chassis frame via separate pairs of springs 390 and 392, respectively. In this embodiment too, the actuates Comparison circuit when one of the driven wheels rotates a certain amount faster than the other, the electric valve, whereby the faster rotating wheel is braked, while at the same time the bellows 324 with pressure medium are supplied. In this way, the weight of the vehicle is shifted from the auxiliary wheels 316 to the driven ones Wheels 306. As soon as the faster rotating wheel stops

- 18 -

909819/0522

December 27, 1977 - 18 -

spins, the brake is released again. Also ventilated the valve restores the bellows, so that the vehicle weight is back on both the driven wheels and the auxiliary wheels lies.

909819/0522

Claims (1)

_ ,. OMV-UIS. M. SC DIPt-PHVS-On. HOGER - STELLRECHV - GRfFSSBACH - HAECKER IN STUTTGART A 42 689 m Applicant: Company Aspro, Inc. ^u - '63 Westport, Conn. 06860 December 27, 1977 USA Patent claims: 1. A device for controlling the traction of a motor ^ / vehicle with a chassis frame, with at least one pair of driven systems which are interconnected via a differential and disposed on opposite sides of the chassis frame wheels, which are connected to the chassis frame, whereby the chassis frame above a solid Area is held, with the brakes assigned to the driven wheels, with at least two speed sensors for generating an electrical voltage signal that is dependent on the respective speed of the driven wheels and with a comparison circuit that delivers a control signal as soon as one voltage signal exceeds the other by a predetermined value, when one driven wheel rotates faster than the other by an amount corresponding to the predetermined value, the electrical control signal actuating the brake assigned to the faster rotating wheel, with an auxiliary axle connected to the chassis frame, the carries a pair of non-driven auxiliary axle wheels, which are arranged in such a way that they touch the fixed surface on opposite sides of the chassis frame next to the driven wheels, with pressure-medium-actuated lifting elements arranged between the chassis frame on the one hand and the wheels on the other hand and with means for controlling the Oruckmittel- 909819/0522 A 42 689 m December 27, 1977 - 2 - 2 7 5 8 9 vs B pressure in the lifting elements, which is activated by the control signal simultaneously with the actuation of the faster rotating The brake assigned to the wheel can be actuated in such a way that more vehicle weight is placed on the driven wheels is relocated, according to patent (Patent application P 26 48 081.9-21), characterized in that the lifting elements (224; 224a, 224b) between the driven wheels (206; 206a, 206b; 3O6) and the chassis frame (202; 302) are arranged and that the Means (226,228,230,232,234,236) for controlling the pressure medium pressure in the lifting elements (224; 224a, 224b) these supply with little pressure medium in normal operation, so that part of the vehicle weight is driven by the Wheels (206; 206a, 206b; 306) on the auxiliary axle wheels (216,216 *, 316) is shifted while this means the Increase the pressure of the pressure medium in the lifting elements (224; 224a, 224b) when a control signal occurs. 2. Device according to claim 1, characterized in that the means which the lifting elements (224; 224a, 224b) supply the pressure medium, a pressure medium source (226), lines, a pressure medium source (226) with the Hydraulic-actuated lifting elements (224; 224a, 224b) connecting control valve (230) and a control valve (230) into the line system between the control valve (230) and the lifting elements (224; 224a, 224b) switched on, solenoid-operated Control valve (234) comprise, which of the control signal generated by the comparison circuit (250) in such a way can be actuated that when the brake assigned to the faster rotating wheel is actuated, the pressure of the pressure 909819/0522 A 42 689 m is increased by means of the lifting elements (224; 224a, 224b). 3. Device according to one of claims 1 or 2, characterized in that the lifting elements (224; 224a, 224b) between the driven wheels (206; 2O6a, 2O6b; 3O6) and bellows disposed on the chassis frame (202; 302). 4. Device according to one of claims 1, 2 or 3, characterized in that one of its two free The ends of the driven axle or the compensating element (280) carrying the auxiliary axle are provided and that the middle part of the compensating element is connected to the chassis frame (202). 5. Apparatus according to claim 4, characterized in that that the driven wheels (206) in front of the auxiliary wheels (216) and that the middle part of the compensating element (280) with the chassis frame (202) via springs (282) is connected. 6. Apparatus according to claim 1, 2 or 3, characterized in that the driven wheels (306) and the Auxiliary wheels (316) via springs (390,392) to the chassis frame (302) are connected. 7. Apparatus according to claim 6, characterized in that. that the driven wheels (306) in front of the auxiliary wheels (316) and that on each side of the chassis frame 90S819 / O52? A 42 689 m December 27, 1977 - 4 - (302) two springs (390,392) one behind the other at a distance are arranged, which corresponds to the distance between the driven wheels (306) and the auxiliary wheels (316). 9 0 <■ '8 1 9/0 5 7 ?