AU625193B2

AU625193B2 - Apparatus for determining the unbalance of wheels mounted on a vehicle

Info

Publication number: AU625193B2
Application number: AU39451/89A
Authority: AU
Inventors: Hermann Bux; Peter Ross
Original assignee: A Rohe GmbH
Current assignee: Beissbarth GmbH
Priority date: 1988-08-23
Filing date: 1989-08-09
Publication date: 1992-07-02
Anticipated expiration: 2009-08-09
Also published as: AU3945189A; EP0355485A2; DE3828610C2; DE3828610A1; EP0355485A3

Description

COMMONWEALTH OF AUSTRALIA FORM PATENTS ACT 1952 COMPLETE SPECIFICATION FOR OFFICE USE: Class Int.Class 'Application Number: Lodged: Complete Specification Lodged: e Accepted: Published: Priority: Related Art: o o C Name of Applicant: A. ROHE GmbH Address of Applicant: Aschaffenburgerstr. 48, D-87521 Schonkrippen, Federal Republic of Germany.

Actual Inventor: Hermann Bux and Peter Ross Address for Service: SHELSTON WATERS, 55 Clarence Street, Sydney Complete Specification for the Invention entitled: "APPARATUS FOR DETERMINING THE UNBALANCE OF WHEELS MOUNTED ON A VEHICLE" The following statement is a full description of this invention, including the best method of performing it known to us:- -1- -2in a known generic apparatus it is -att-empted to transmit measurement signals from the measuring rack to a display means which is included in the device which is used for driving the wheel. Said known apparatus has, however, turned out to be not functional. Moreover it is not suited for effecting the balancing operation on the vehicle if such vehicle has a permanent all-wheel drive.

Summary of the Invention I It 20 I I II It is an object of the present invention to provide an apparatus; for determining the unbalance of wheels mounted on a vehicle, wherein the measuring operations at the individual 3 wheels may be effected in short time without changing the places of location of the equipment or the service staff.

It is a further object of the present invention to provide an apparatus for determining the unbalance of wheels mounted on a vehicle, wherein the measuring operations may be carried out easily with as little bulk as possible.

For this effect the apparatus according to the present inven- Stion is characterized in that a central display and control ,t unit is provided for several measuring racks and that the measuring racks and the display control means comprise transmitter/receiver means for signal transmission, wherein signals from the measuring racks can be transmitted to the display control means and control signals from the display con- 'I trol means can be transmitted to the measuring racks.

By means of the central display and control unit, it is possible to interrogate the unbalance measurement signals from the measuring racks as well as to forward control signals to the measuring racks while the central display and control unit remains in one and the same place, e.g. in the hand of the service person sitting in the vehicle.

The measuring process is essentially simplified in that the measured values of the individual wheels can be interrogated subsequently.

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4 According to a further advantageous embodiment of the invention the appardtus is characterized in that the transmitter/ receiver means at the measuring racks are formed thus that the measurement and control signals can be transmitted through each of the measuring racks to other measuring racks.

Thereby it is rendered possible to transmit the measurement and control signals between the measuring racks and the display control means as soon as one transmission path exists from the display control means to one of the measuring racks.

"*lO Thus the local position of the display control means can be arbitrarily chosen within a great range without any problems arising with respect to so-called transmission shadow area.

o According to a further advantageous embodiment of the present invention the apparatus is characterized in that the trans- 15*. mitter/receiver means comprises infrared transmitters and receivers and that transmitters are provided radiating polydirectionally, wherein in particular at one measuring rack two or more transmitters and receivers are disposed. Infrared Lt t frequencies are preferred because when using radio frequencies disturbances have to be expected with respect to other measuring instruments and it might become necessary to have special perdmission for using such frequencies. By applying the infrared transmission the use of infrared frequencies does not give rise to any problems.

A further advantageous embodiment of the present invention is characterized in that the measuring/control means is located a~ 1 i, r ~LC in the measuring rack and that the transmitter/receiver means are disposed between the measuring/control means and the display control means. When the measuring portion as well as the control portion of the measuring/control means are located in the measuring rack, it is possible to transmit the control signals as well as the measurement signals scanned at the measuring rack through one transmission path.

rc€r An advantageous embodiment of the apparatus according to the present invention, comprising a scanning means including a S transmitter and a receiver for scanning a marking on the O0 wheel, for issuing a speed signal representing the speed of the wheel when the wheel is driven is characterized in that the scanning means is arranged at the measuring rack at its side facing the wheel and that the transmitter and the receiver of the scanning means are operated using another frequen- 0: -y for signal transmission than the transmitter/receiver means. In this case the scanning means are preferably located opposite to the tread of the wheel in case of a measuring rack being arranged at the wheel, wherein a marking located on the tread of the wheel can be scanned. By means of said •i apparatus the unbalance signals for the magnitude and the direction of the unbalance as well as the speed signals and the control signals can be transmitted through one and the same transmission path.

A further advantageous embodiment of the apparatus according to the present invention is characterized in that a first r t S6 identification modulator/demodulator is provided in the measuring/control means in the measuring rack and a second identification modulator/demodulator is provided in the display control means, for correlating the signals transmitted between the measuring/control means in the measuring racks and the display control means to a certain measuring rack and/or wheel, respectively by means of an identification set. This considerably facilitates the handling of the apparatus, as all measurement units can work simultaneously and the measu- 'j red values can be subsequently interrogated using the identification information.

.f ti A further advantageous embodiment of the apparatus according to the present invention is characterized in that change-over means are provided in the display control means and in the 4 6 15, measuring/control means of the measuring racks for switching the identification modulators/demodulators to additional t tI identification sets. Thereby disturbances are avoided if two vehicles are measured side by side at the same time.

Further advantageous embodiments of the apparatus according to the present invention are characterized in that the display control means includes a flexible light guide, at the end of which a lens is located or that the display control means comprises a line, at the end of which a transmitter/receiver unit is arranged. Thereby the transmission/receiving level is shifted to a level below the vehicle frame so that s -7the service person can sit inside the vehicle without impairing the signal transmission by transmission shadow areas.

List of Figures Now embodiments of the present invention will be explained in more detail with reference to the enclosed drawings. In the drawings: Fig. 1 shows a side view of a measuring rack; Fig. 2 shows a schematic view of a vehicle with measuring racks supporting the four wheels and with the display control means; Fig. 3 shows a top view of the display control means; Fig. 4 shows a side view of a first embodiment of a display control means; Fig. 5 shows a side view of a second embodiment of the display control means; Fig. 6 shows a third embodiment of the display control means.

Detailed Account of Working Example of the Invention Fig. 1 shows a measuring rack 2 comprising a stand 4 with wheels 6, 8. A pick-up crown 14 is arranged at the stand 4 by means of a column 10 and a support column 12. By means of the crown 14 the lifted vehicle wheel 16 is supported in a desired height. The colum 10 is connected to the column 12 through two girders 18, 20 and a sensor 22, for example a

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8 piezoelectric force sensor, is located between the support column 12 and the stand 4. With this arrangement the vibrations caused by the unbalance of the vehicle wheel 16 are sensed by the sensor 22 which thereupon issues sensor signals to a measuring/control means 26 through a line 24. For detecting the direction of the unbalance and the speed of the driven vehicle wheel 16 a marking 28 is provided on the tread of the vehicle wheel 16, such marking being scanned by means of a transmitter 32 and a receiver 34 disposed at the side of i the stand 4 opposite to the tread 30. Said transmitter 32 is c, connected to the measuring/control means 26 through a line 36 and said receiver 34 is connected thereto by means of a line 38. In a manner known per se said measuring/control means 26 generates signals corresponding to the magnitude of the unbalance and the direction thereof and of the speed of the wheel 16 from the signals of the sensor 22 and the receiver 34 and in wireless manner transmits the corresponding signals to a display control means 40 (Fig. The infrared frequency range is preferred for such transmission. In this case polydirectionally radiating transmitters are used, comprising several transmitting diodes being arranged in a circle and issuing radiation outwardly. Two such transmitters 42, 44 are provided in the measuring rack 2 of Fig. 1, one 42 of the transmitters being disposed on the side of the column 12 not facing the wheel 16 and the other 44 of the transmitters being disposed on the face 46 pointing to the outside, of the stand 4. The transmitter 42 is connected to the measuring/ control means 26 through a line 48 and the transmitter 44 is ,It -9connected thereto through a line 50. The measuring/control means 26 also receives control signals from the display control means 40 through a receiver 52 and/or a receiver 54, the two receivers 52, 54 being connected to the measuring/control means by lines 56 and /or 58, respectively. If several transmitters/receivers are arranged at one measuring rack 2 for transmitting the signals between the measuring/control means and the display control means in distributed manner, a safe transmission of the signals is also guaranteed, if the direct i I. transmission path between one transmitter/receiver pair is interrupted, e.g. by a wheel.

Fig. 2 schematically show a vehicle 60 with four wheels 16 and four measuring racks 2, each of which being arranged under a wheel, in order that a vehicle with permanent all-wheel drive can be measured with respect to unbalance. The main S display and control means 40 is provided for all four measuring racks. The measuring racks 2 as well as the display control means have transmitters and receivers for signal transmission, the signals being transmittable from the measuring racks 2 -to the display control means 40 and control Ssignals being transmittable from the display control means to the measuring racks 2 and/or to the measuring/control means, respectively, arranged in the measuring racks. For making it possible to correlate the signals transmitted between the measuring racks and the display control means 40 to a certain measuring rack and /or wheel, respectively, identification modulators/demodulators are disposed in the display i0 control means 40 and in the measuring/coiitrol means 26 of the measuring racks 2, wherein a definite identification modulator/demodulator located in a measuring rack can be adjusted to one identification being characteristic for one particular wheel, such identifcation then being recognized by the identification modulator/demodulator in the display control means For adjusting the identification in one definite measuring rack a keyboard 62 is provided, being schematically shown in Fig. 1. The keyboard 62, e.g, has four keys for "measuring rack located left-hand side, front", "measuring rack located right-hand side, front", "measuring rack located left-hand side, rear" and/or "measuring rack located righthand side, rear". If two vehicles are standing side by side and are to be measured at the same time, a further identification set can be allotted to the second vehicle. For this purpose change-over means for switching to further identification sets are provided in the display control means and in the measuring/control means.

According to Fig. 3 the display control means 40 comprises a LCD-field 64. The points 66 arranged in '.he manner of a clockface indicate the direction of the unbalance with respect to a reference point. The points 68 in which schematically markings 70 for the wheels of the vehicle and a schematical draft 72 for the vehcile 62 are shwon, indicate which wheel is measured presently. A numerical display 74 serves for displaying the magnitude of the unbalance and/or the t speed of the wheel, respectively. A bank of keys 76 comprises i 1 1 11 *I S il 11 a key 78 for starting/stopping the measurement operation, a key 80 for change-over from gram to ounce display, a key 82 for interrogating the wheel speed, a key 84 for interrogating the unbalance data as to magnitude and direction and a key 86 for activating the change-over means for switching over to another identification set.

Fig. 4 shows schematically in which way a transmitter 88 and a receiver 90 are arranged at a chamfered face wall in the ft..

display control means 40. Thus transmitter and receiver are .01 orientated in oblique downward direction so that a transmisoQ sion path between the display control means 50 and the transmitters/receivers in the measuring racks 2 can be produced when the display control means 40 is held out of the window of the vehicle or is directed to the measuring racks laterally from the vehicle. For simplifying the handling it is provided in display control means 100 (Fig. 5) and/or 102 (Fig.

respectively, that the point in which signals are issued and/or received by the display control means is shifted to a plane below the vehicle frame. For this purpose the transmitter/receiver is located in the very means in case of the display control means 100 and the signals are forwarded by the transmitter through a light guide 104 and a lens 106 and/or received through the lense 106 and forwarded to the light guide 104 to the receiver. In the display control means 102 the transmitter/receiver unit 108 is located at the end of an electric line 110.

i 12 The above description with respect to the drawings refers to the measurement of a vehicle with permanent all-wheel drive.

In other cases when separate driving units are provided for driving the wheels, such driving units can receive respective control signals through the display control means for starting or stopping, accelerating or braking down the drive.

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Claims

1. An apparatus for determining the unbalance of wheels mounted on a vehicle, comprising at least one measuring rack for supporting a vehicle wheel; a sensor provided in the measuring rack for sensing vi- brations caused by the unbalance and for issuing a sensor signal; a measurement/control means generating unbalance signals representing the unbalance with respect to magnitude and r r tdirection from the sensor signals; a central display and control unit provided for several measuring racks, in which display means of the central display and control unit at least the unbalance magnitude is displayed, the measuring racks and the display control means com- prising transmitter/receiver means for wireless signal transmission between the sensors and the display control unit, whereby signals are transmitted from the measuring racks to the display control means and control signals from the display control means to the measuring racks; the display control means including a flexible light guide at the end of which a lens is located for communicating with the transmitter/receiver means of the measuring racks at level therewith.

2. An apparatus for determining the unbalance of wheels moun- ted on a vehicle, comprising at least one measuring rack for supporting a vehicle wheel; a sensor provided in the measuring rack for sensing vi- brations caused by the unbalance and for issuing a sensor 1P signal; -14 a measurement/control means gener: :ing unbalance signals representing the unbalance with respect to magnitude and direction from the sensor signals; a central display and control unit provided for several measuring racks, in which display means of the central display and control unit at least the unbalance magnitude is displayed the measuring racks and the display control means com- prising transmitter/receiver means for wireless signal transmission between the sensors and the display control unit, whereby signals are transmitted from the measuring racks to the display control means and control signals from the display control means to the measuring racks; the display control means comprising an electrical line at the end of which a transmitter/receiver unit is arranged for communicating with the transmitter/receiver means of the measuring racks at level therewith.

3. An apparatus for determining the unbalance of wheels moun- ted on a vehicle, comprising at least one measuring rack for 'supportla3g a vehicle wheel; a sensor provided in the measuring rack for sensing vi- brations caused by the unbalance and for issuing a sensor signal; a measurement/control means generating unbalance signals representing the unbalance with respect to magnitude and direction from the sensor signals; a central display and control unit provided for several measuring racks, in which display means of the central display and control unit at least the unbalance magnitude is displayed i the measuring racks and the display control means com- prising transmitter/receiver means for wireless signal transmission between the sensors and the display control Q unit, whereby signals are transmitted from the measuring racks to the display control means and control signals LI from the display control means to the measuring racks; the transmitter/receiver means at each of the measuring racks being arranged with respect to each other so that the measurement and control signals are transmitted between measuring racks.

4. An apparatus as defined in any one of claims 1 to 3, wherein the transmitter/receiver means comprises infrared transmitters.

An apparatus as defined in any one of claims 1 to 4, wherein several transmitter/receivers means are arranged in one measuring rack.

6. An apparatus as defined in in any one of claims 1 to wherein the transmitter/receiver means comprise multidirec- tionally radiating receivers and transmitters.

7. An apparatus as defined in in any one of claims 1 to 6, wherein the measuring/control means are located in the measuring rack and the transmitter/receiver means are dispo- sed between the measuringcontrol means and the display con- trol means.

8. An apparatus as defined in in any one of claims 1 to 7, wherein a scanning means including a scanning transmitter and a scanning receiver for scanning a marking on the wheel is M provided for issuing a speed signal representing the speed of the wheel when the wheel is driven, wherein the scanning means is arranged at the measuring rack at its side facing Lit the wheel and the scanning transmitter and the scanning re- ceiver of the scanning means are operated using another fre- quency for signal transmission than the transmitter/receiver means.

9. An apparatus as defined in claim 8, wherein the scanning /7v" means is located on the measuring rack in such manner that it i i 5 4 C -16 is opposite to the tread of the wheel, whereby a marking located on the tread of the wheel can be scanned, when the measuring rack is arranged at the wheel.

An apparatus as defined in claim in any one of claims 1 to 9, wherein a first identification modulator/demodulator is. provided in the measuring/control means in the measuring rack and a second identification modulator/demodulator is provided in the display control means, for correlating the signals transmitted between the measuring/control means in the measuring racks and the display control means to a certain measuring rack and/or wheel, 'respectively by means of an identification set.

11. An apparatus as defined in claim 10, wherein the first identification modulator/demodulator in a measuring rack can tI, 1' be adjusted to a identification being characteristic for a t. certain wheel.

12. An apparatus as defined in claim 10, wherein a keyboard means is provided for ajdusting the identification.

13. An apparatus as defined in claim 10, wherein change-over means are provided in the display control means and in the t' l measuring/control means of the measuring racks for switching r the identification modulators/demodulators to additional identification sets. DATED this 7th day of APRIL, 1992 A. ROHE GmbH cflow Institute of Ptcni An-i9ns; of r l la04 1 3 of SHELS i 3TO .2S i (i *4