FR2558591A1 - MACHINE AND METHOD FOR BALANCING RELATIVELY LARGE OBJECTS SUCH AS TRUCK TIRES - Google Patents

Abstract

THE INVENTION PROVIDES A MACHINE AND A PROCESS FOR CONVENIENTLY OPERATING THE BALANCING OF HEAVY ROTATING ELEMENTS. THE MACHINE INCLUDES A HORIZONTAL SHAFT 20 MOVING VERTICALLY TO COME TO THE RIGHT OF THE CENTER OF ELEMENT 25 STANDING ON THE GROUND AND ENTERING THIS CENTER; THEN THE SHAFT IS RAISED VERTICALLY UNTIL THE ELEMENT 25 MOVES AWAY FROM THE GROUND AND CAN TURN FOR BALANCING PURPOSES; IN PREFERRED EMBODIMENTS, THE BALANCING MECHANISM 8 CAN BE SEPARATED FROM THE MACHINE BASE FOR TRANSPORT AND THE UPRIGHT 56 OF THE BASE 50 IS INCLINED TO PRELOAD THE BASE BY THE WEIGHT OF THE ELEMENT AND REMOVE THE GAME PRESENT IN THE BASEMENT; THE MACHINE IS PORTABLE AND OFFERS ADVANTAGES FOR TRANSPORTATION. APPLICATION IN PARTICULAR TO THE BALANCING OF WHEELS OF LARGE VEHICLES.

Description

The present invention relates to methods and apparatus for

  determining the imbalance of a rotating element, in particular a wheel, and more particularly the methods and apparatuses for dynamically determining the imbalance of a rotating element. Although the invention is described below with reference in particular to wheel balancing, it should be noted that some of its

  aspects are applicable to other types of rotating elements.

  such as rotors or the like. It will be noted that,

  in the present invention of balancing

  brage "wheels", the balancing is actually on a tire wheel assembly, and it is this set that designates the word "wheel".

  At present, there are two basic types of

  system rate for determining the imbalance of a wheel on which a tire is mounted. One of these types of systems is a static system, in which the wheel and the tire remain motionless during the determination of their possible imbalance. For example, the wheel may be supported in a horizontal orientation by means of a leveling type support device having a bubble or similar indicator that moves from a central reference point in accordance with the imbalance of the neum-ïatique. By placing appropriate weights at carefully selected points around the rim of the wheel rim, the operator can vary the location of the wheel.

  indicator bubble to bring it to the reference point.

  Then the weights are attached to the wheel at the points

so. determined.

  The second dynamic fundamental type of equilibrium system

  librace-wheel has been developed to provide a more complete indication of the imbalance of a wheel and how it can be corrected. In dynamic wheel balancing systems, the wheel to be balanced is mounted on a

  shaft that is brought to a predetermined rotational speed.

  Once this desired speed is reached by the wheel, we measure

  the transverse displacements of the tree or the forces

  drowned by the shaft due to the imbalance of the wheel. According to these measurements, one can obtain indications on the size

  the imbalance of the wheel and the location of the imbalance

  free. Although a dynamic balancing system can be used to determine the unbalance location in a single plane, this method can detect, distinguish, and correct centrifugal counter balance forces in two planes, generally inside and outside of the wheel. Thus, we manage to correct more precisely the imbalance. Then, we dismount the wheel of

balancing device.

  Typically, the rotational speed of the wheel is now

  constant hold at 400 rpm or more during the measurement of

  dynamic balance. Such a speed has been adopted for various reasons. One of these reasons is that it is easier to measure the imbalance forces at high speed because the magnitude of the unbalance forces is proportional to the square of the rotational speed. At high speeds,

  very favorable signal-to-noise ratios are easily obtained.

  Another reason is the erroneous but widespread belief that you have to balance the wheels at

  rotation close to those reached on the road.

  US Patent 4,435,982 (Borner and Jackson) discloses a

  improvement in dynamic balancing devices

  that, according to which the measuring rotational speed is reduced to less than 360 rpm and the unbalance measurement is performed while the wheel drive device is uncoupled

and that the wheel turns inertia.

  GB Patent Application 83,30,356 (Borner and Jackson) discloses a further refinement that the necessary rotational speed is further reduced to 100 rpm or even less and the wheel is rotated manually then

it is allowed to spin by inertia.

  Machines materializing patent and demand

  Borner-Jackson are being marketed. These arrangements

  Counterbalance machines are characterized in that they operate the unbalance measurement when the free rotation speed has decreased to equal one or more than a predetermined measurement speed. The manually-engineered machine plays a particularly good role in this respect. However, with this machine, inexperienced operators sometimes throw the wheel by hand at a speed much higher than that predefined for the measurement and it is necessary to waste time waiting for the wheel to slow down to the speed of measurement.

  These machines and, to our knowledge, other devices

  Dynamic balancing devices, have the characteristic that the support of the rotary shaft, on which the wheel is mounted, is fixed to a base or pedestal. The wheel is manually raised to rest on the shaft and mounted so that it does not touch the ground and rotate around its axis. This is a very simple configuration

  convenient when the wheels to be balanced are motorcycle wheels

  cyclette or light automobile. However, when it comes to large and heavy wheels, that is to say, big wheels or truck, setting up and mounting become difficult and dangerous. An independent lifting device, such as a jack or lifting fork, is usually necessary and it often takes two people to put the wheel in place and mount it. This greatly increases the time and the balancing costs of these wheels

big and heavy.

  Another difficulty that arises when balancing large and heavy wheels is that the wheels are not easily portable and it would often be better to bring the balancer to the wheel rather than the other way around. The above-mentioned hand-made machine is portable, but other balancing machines used so far are large pieces of demanding equipment.

  usually a permanent installation in the workshop.

  The object of the present invention is therefore to propose: in a general manner, an original method and apparatus for determining the imbalance of a wheel or the like which makes it possible to operate as precisely as with other devices dynamic wheel balancing but without the limitations striking these;

  - an apparatus for the dynamic determination of the

  balancing a wheel which does not require a predetermined rotational speed to perform imbalance measurements and therefore operates the measurements in a substantially uniform time; a method and apparatus for dynamically determining the imbalance of a wheel, which makes it possible to mount the wheel in such a way as to substantially reduce the effort and the risks that the installation of large wheels previously entailed; - an apparatus for dynamically determining the imbalance of a wheel that is portable and mobile and fit to serve

on the spot.

  To achieve these and other objects, the present invention provides a wheel balancing system that does not use a predetermined speed of measurement and is therefore able to determine the imbalance of a wheel at full speed included in a certain interval. We have

  found that this result can be achieved through a

  balancing system using an electronic

  measurement comprising a digital-to-analog converter

  tiplicator which receives one or more output signals respectively provided by one or more force measuring transducers of the balancer and presents them to a microprocessor. The microprocessor compares them with threshold levels and sends a command signal to the converter to multiply the input signals by an amount such that they are within a range

  admissible when presented to the microprocessor.

  Thus, that the wheel to balance turns at a low speed

  (showing relatively large amplitude input signals

  weakly) or at a high speed (showing much larger input signals),

  signals are likely to be processed in the micropro-

  once properly amplified to be understood

in the operating range.

  It has further been found that the present invention enables wheel balancing at very low speeds by upward adjustment of small signals obtained at low speeds. This aspect is advantageously applicable to the balancing of large, difficult and dangerous wheels

  to ride such as truck wheels. This invention

  Furthermore, it proposes a dynamic wheel balancing system which does not require the operator to manually lift the wheel to place it on the balancer shaft

  to turn. This system has a horizontal balancing shaft

  zontal rotatable, own to support the wheel to balance. This shaft is movable upwards and downwards relative to the base of the balancing device and to the

  floor, the base itself being preferably horizontally movable

  on the ground, for example by means of wheels, rollers, or skids. Thus, the balancing device is a mobile unit so that it can be brought near an erect wheel

  vertically, then adjust the balancer shaft to the

  They wanted it to be at the center of the wheel.

  After attaching the wheel to the shaft, raise the shaft until the wheel moves off the ground. The wheel is then rotated and its imbalance determined. We let the wheel stop spinning. The wheel can be stopped by simply allowing the winding resistance and the bearing friction to slow down, providing the balancing device with a braking mechanism or, preferably, stopping the wheel in rotation down to that it wears lightly against the ground, this contact stopping the wheel. The weights 3 are then fixed to the wheel to correct the imbalance. If you have lowered the wheel to slow down its rotation, it is usually necessary

  lift it to properly position the correct weights

  facilitators. Then, the shaft and the wheel attached to it are lowered until the wheel rests on the ground, the wheel of the balance shaft is then disconnected and

  the balancing device can be removed from the wheel.

  According to a preferred embodiment of the principles of the invention, the ascending-descending movement of the shaft relative to the base is somewhat oblique with respect to

  vertically through the horizontal balancing shaft

  tal. Thanks to this geometry, the gross weight of the wheel can precharge or self-lock the base of the balancing device by forces greater than the maximum imbalance forces occurring during balancing. This makes

  the vibrations generated by the unbalanced wheel

  remain unamplified and minimize the para-

  site and the vibrations not resulting from the forces of

  balance of the wheel during the rotation of the wheel.

  This geometry and the preload it ensures improve

  portability of the device. The rotatable balancer shaft and the supporting structure in which it is journalled and the electronic assembly (i.e. the balancing head), relatively precise and inherently sensitive, can be dismountable on the the base is relatively more robust and heavy so that the base can be transported without worrying about damaging the balancing head, which can itself be transported and giving it better protection. The preload corrects the freedom and makes up for the existing gap between the balancing head assembly and the base, thus making it possible to provide very wide gaps between these two elements.

  which ensures the ease of re-assembly.

  Although aspects of the present invention that have

  relating to the adoption of a speed of balancing not pre-

  selected to be satisfactory for the balancing of large and heavy truck wheels and are thus particularly advantageous in combination with the aspects of the present invention which relate to a shaft with adjustable position, it is conceivable that these two aspects of the invention may also be to be implemented separately. Thus, for example, provision can be made for using a non-preselected balancing speed in balancing devices such as those described in US Serial No. 444,885 or the like. Similarly, we could associate the tree

2558591-

  with adjustable position to another electrical measuring arrangement.

  It will be better understood how the present invention makes it possible to achieve the aforementioned objects and the advantages which

  derive from the detailed description given below.

  below as examples of certain preferred embodiments of the invention, with reference to the accompanying drawings in which: - Fig.] is a perspective view of a standard balancing shaft and measuring head apparatus for generating electrical signals relating to imbalance forces; - Fig. 2 is a perspective view of an adjustable-position shaft wheel balancer constructed in accordance with the principles of the present invention and having a balancing head device as shown in FIG. 1;

  - Fig. 3 is a front elevational view of an apparatus

  balance wheel as shown in Figure 2; - Fig. 4 is a schematic block diagram of the electrical mounting portion of a balancing device of

  wheel which does not use a predetermined speed of measurement

  undermined; Referring to Figure 1; the wheel balancing device head 8 shown in this figure comprises a frame 10 able to properly support all the mechanical and electrical components of the balancing head. The frame basically comprises an oblong tube section of generally square or rectangular shape. A tubular body 12 is suspended from the upper wall of the frame 10 so as to

  to be able to transmit forces in one direction only.

  The support mechanism of the body 12 comprises two metal strips 14 and 16 which are sufficiently flexible to

  freedom of movement in a single horizontal direction

  The metal strips are sufficiently rigid not to undergo compression or elastic elongation and thus to oppose the movement of the body 12 in a manner that is consistent with the direction indicated in A-B in FIG.

  vertical direction. In addition, the strips 14 and 16 are rigid.

  fixed to both the frame 10 and the body 12 so as not to be pivotable in a vertical plane, thus opposing the displacement of the frame in a longitudinal direction,

  that is to say in a direction perpendicular to A-B.

  The body 12 is further supported by a vertical rod 18 which is attached to the side of the body opposite the strips 14 and

  16 and which leaves the body the necessary freedom of movement.

  A balance shaft 20 journalled in the body 12 through bearings 22. A flange or mounting plate

  24 is attached to one end of the shaft 20 and provides a.

  suitable support surface against which a wheel 25

  to balance bute when mounted on the shaft 20.

  A frustoconical hub mechanism can be screwed onto the shaft to lock in place the wheel to be balanced or, according to the variant illustrated in Figures 2 and 3, the wheel can be bolted to the plate 24 by bolts and nuts

conventional wheel fasteners.

  A timing disc 30 is mounted on the end of the shaft 20 opposite to the mounting plate 24. The disc has a number of radial slots or marks, distributed around its periphery, which cooperate in a well-known manner with an encoder electro-optical 32 to provide an electrical pulse signal related to the angular position

  and at the speed of the disk 30, and therefore of the shaft 20.

  The lateral forces generated by the shaft 20 during its rotation, due to an imbalance of the wheel subjected

  measurement are detected by piezoelectric transducers.

  34 and 36 which protrude through one of the side walls of the frame 10 and bear against the body 12. The base of the body 12 may have bosses 40 which protrude on its side and make the body only bears against the transducer elements 34 and 36 and does not bear against any other part of the frame 10. The body is pressed both downwards and laterally against the transducers by two spring fingers 41 which are fixed

  at frame 10 and in contact with the body 12.

  As is well known in the field of equi-

  dynamic tire release, the transducers for detecting the lateral displacement undergone by the rotating shaft due to the imbalance of the wheel must be located at two locations spaced along the length of the shaft so as essentially to measure the pivoting of the wheel. tree

  around a vertical axis passing through its middle.

  Timing encoder 32 and transducers 34, 0 and 36 are mounted on a single printed circuit board 45 which also suitably supports and interconnects all other electronic components of the device.

  wheel balancing. These electronic components include

  try a good classic circuit that builds a relationship

  between the output signals of the transducers and the information

  their location in relation to the parties concerned.

  the rim of the wheel to be balanced, as well as the speed of rotation of the wheel, and provides

  an indication of the measured imbalance of the wheel. The infor-

  This may be indicated on suitable display devices 48 which are also mounted on the printed circuit board 45. The circuit board 45 includes the circuit which

  operates the imbalance measurement at a non-predetermined speed

  The circuit panel 45 may be mounted on the frame or attached to an outer cover (not shown).

affect & balancing head.

  The balance shaft 20 still carries a crank 42 designed to rotate the shaft 20 and the wheel 25 to

  determine the imbalance of the latter. The way

  Velle 42 is preferably designed to drive in one direction and to coast freely in the other so that rotation of the wheel does not dangerously turn the crank. This result can be obtained, for example, by fixing a sleeve 43 mounted on the crank 42

  to the balance shaft 20 by means of a winding spring

  44 or any other unidirectional coupling device

appropriate.

  The balancing head assembly 8 is mounted on a base 50 as shown in Figures 2 and 3. This base

  is designed to allow head assembly 8 to move

  cer upwards and downwards and bring the shaft 20 to the right of the center of the wheel 25 and the wheel bolts 26 to the right of the corresponding bolt holes of the wheel 25 in view

  fixing by the wheel mounting nuts 28.

  This result can be achieved by attaching the head assembly 8 to a bracket 52 itself attached to a carriage 54 which moves up and down on an inclined post 56. The position of the carriage 54 must be fixed by a control which allows a relatively fine adjustment, such as an adjustment within + 1 mm, so as to allow the precise centering of the head of the balancing device on the wheel attachment nuts, etc. One way to perform the adjustment is to use a threaded shaft 76 driven through a nut plate 78 on the upright 56 by means of two corner gears driven by a crank 58. The crank 58 can be provided with of a handle 71. The corner gears 72 and 74 are enclosed in a gear case 60. The bearings and the structure for securing the carriage 54 of the shaft carrying the corner gear 72 are conventional and we will refrain from describing them for brevity. when

  rotates the driving angle gear 72, it drives

  same pinion 74 and rotates the threaded shaft 76, thus brought up and down because of its interaction with the nut plate 78. A stop nut 80 is provided on

  the end of the shaft 76. The amount 56 is fixed at the

  61 of a substantially U-shaped structure formed by the cross member 61 and branches 62 and 64. This U-shaped structure comprises wheels or rollers 66 and 68 which come into play when the balancing device, tilted backwards. ,

  build on them and allow the balancing device to

  to move to the wheel. There is provided on the cross member a shoe M0 as shown in FIG. 2 or a rigid wheel 70A as represented in FIG. 3

  to facilitate the final positioning of the equi-

  liberation by the wheel while offering a solid base at

  balancing device during the balancing operation.

  Note that the nut plate 78 simply rests on the top of the upright 56 and that the opening of the latter is large enough not to encroach on the nut of the

  nut plate 78. Therefore, the entire balance head assembly

  brage 8, as well as the associated console 52 and the mechanism

  vertically can be separated to raise

  if it is desirable for transportation or storage. This disassembly makes it possible to separate the balancing head, precise and more delicate, from the heavy base and

more solid.

  It should also be noted that, preferably, the amount 56

  along the length of the shaft 20 is not perpendicular -

  61. The angle A makes with the perpendicular

  dicular is 10 in the example illustrated but could be between approximately 3 and 20 and in particular between 5 and 15. With this inclination, when a wheel is mounted on the shaft 20, its weight applies a torsion force which loads the bracket 52 and the carriage 54 against the upright 56 and loads the upright 56 against the lower structure formed by the cross member. 61 and by the branches 62 and 64. This load, which represents a greater force

  that the imbalance forces generated during the operation

  equilibrium ration, absorbs the game or the freedom possibly existing in the base structure and minimizes the risk of occurrence of disturbing vibrations and harmonics

  in the balancing device itself.

  In use, remove the wheel to balance the truck

  and make it stand upright. The provision is

  balancing machine near the wheel. The operator adjusts the

  vertical position of the balancing head

  crank 58 until the mounting bolts

  wheel are at the corresponding holes of the wheel.

  The balancer is then pushed forward until the wheel attachment bolts 26 engage the corresponding holes in the wheel and wheel mounting nuts 28 are applied to hold the wheel . The exact way of mounting the wheel on the shaft 20 is not

  capital for the implementation of the present invention.

  Instead of wheel bolts 26 and nuts 28, a bolting plate and associated bolts could be used. In a similar way, a wheel having a precisely defined central hole can be mounted by means of a cone engaging in this hole in a manner known in

  the job. Once the wheel is up, we turn the wheel

  velle 58 to lift the wheel until the tire

  away from the ground and the wheel spinning freely.

  The operator inputs information relating to the distance between the transducers of the inner rim flange of the wheel being measured (i.e., the transducer offset) and the spacing between the flanges of the wheel. inner and outer rim of the wheel and the diameter of the wheel. Typically, we can determine

  this information empirically based on the dimensions

  Standard wheel studs and the mechanism for introducing this information, for example potentiometers 46 (FIG 1), can be calibrated according to standard wheel dimensions. Once the desired information is introduced, the wheel is set in motion by manually grasping the wheel or crank 42 and applying a rotational force thereto.

  When the wheel has reached a higher rotation speed

  below a minimum required speed, a signal is provided to the operator to indicate that there is no need to apply a rotational force. This speed does not have

  to be superior, and is preferably substantially less than

  higher, at 180 rpm. The balancing device measures the imbalance forces and signals the operator the completion

  of this measure. We then slow down the wheel as in the

  lying down until she rubs on the floor. When it is stopped, it is lifted again, the weights necessary for balance and their locations are displayed on the visual 48 and we can put the weights

  on the wheel to balance it.

  According to another aspect of the invention, the circuit

  measurement method preferably allows the measurement of

  Balances at any rotational speed given in a relatively wide velocity range. A circuit of this type is particularly interesting in dynamic balancing devices of the type in which the rotation is printed manually to the wheel, so that its speed

  can vary widely depending on the force exerted by the operator.

  This variation of the speed of rotation of a measurement to

  the following is particularly evident in the

  balancing heads capable of accommodating a wide variety of tire formats, as described with respect to

Figures 2 and 3.

  Referring to Figure 4; in a circuit putting

  this principle, the output signals of the transduc-

  Piezoelectric drivers 34 and 36 are respectively amplified in amplifiers 102 and 104. Output signals

  amplifiers of these amplifiers are applied to two conver-

  digital-to-analog weavers (HDACs) 106 and 108. In operation

  In addition, MDACs multiply each analog input signal

  only by a factor determined by a digital signal, then this multiplied signal is applied to a microprocessor 110.

  In the microprocessor, the analog input signals

  are put in digital form by an internal converter.

  The MDACs are set initially (before the time when the first measurements are made) so as to multiply the signal by a factor which is determined from the wheel span values and also by the wheel diameter. The diameter value of the wheel is introduced

  in the microprocessor by a manually adjusted potentiometer-

  112. The speed of the wheel is measured. This factor can be determined empirically for different types of wheels so that a signal multiplication results which has the greatest chance of bringing the amplitude of the adjusted input signal to the middle of the operating range.

microprocessor.

  When the input signal is so large that it goes out of the operating range of the microprocessor, the HDACs are

  invited to reduce the transducer input signal,

  That is, to multiply it by a factor of less than one. Even-

  MDACs can also be used to increase the

  low level signals possibly provided by slow rotational speeds, for example. Once the input signal is properly adjusted, the microprocessor acts on it in a conventional manner to determine the imbalance state of the wheel. By limiting the operating range in which the microprocessor must work, more accurate results are obtained at lower cost. For example, a less expensive microprocessor with a relatively small (e.g. 8-bit) internal-to-digital converter may be used instead of a larger microprocessor & converter to cover larger ranges. The comparison of the input signal with the threshold values and the proper adjustment of its level can in general be carried out in about 3 to 5 turns of the wheel. So it is possible to perform this operation for each measure

  without losing a significant amount of time, particularly

  to relate to the time it takes for a big wheel to slow down to a fixed measuring speed if

  it was initially launched in rotation too strong. As a result

  a wheel balancing device incorporating this

  circuit can effectively serve to balance a great.

  variety of tires of different sizes, which may

  to be launched each at a different speed.

  More specifically, in this circuit, the output signals of transducers 34 and 36 are shown after passing through a suitable amplifier stage 102 and 104 and filter circuit to a two channel MDAC 10. The MDA separately blocks each of these input signals in accordance with the 8-bit command signal received from the microprocessor 110 on a data bus, and provides two adjusted output signals. These output signals are presented after proper pre-amplification and processing. in intermediate stages to the microprocessor.

  Once the input signals have been adjusted to the appropriate level

  nable within the operational range of the microprocessor, the latter uses them, together with the signals from the encoder 32 which indicate the angular position of the wheel

  and its direction of rotation, to determine the state of imbalance

  of the wheel according to classical algorithms. These algorithms

  Themes, along with appropriate constants and calibration values, are stored in memory circuits

  addressed by control signals issued by the microproces-

  on the data bus. Once the imbalance

  measured, the microprocessor acts on exciters

  to put in action display units to provide an indication of the amount of weight to be added to the wheel to balance it. The microprocessor

  also determines the activation of various diodes

  luminescent lights (LEDs) to guide the operator in pivoting the wheel so that he puts the weight in the right place. In addition to these LEDs, the microprocessor may activate a buzzer or other suitable audible or visual indicator to indicate when the wheel has reached a sufficient rotational speed to perform

a measurement.

  As conceived by the technician of competency

  rante, the invention can be embodied in other forms

  particulars without departing from its scope. The modes of

  currently described are therefore given for

  examples without any limiting character.

Claims (13)

  1.The process of determining the imbalance of a   wheel, characterized in that it comprises the operations   both to: put the wheel standing on the ground in position in   vertically, vertically align a horizontal tree   zontal capable of turning to the right of the center of the wheel and engage the shaft on the wheel, mount the wheel on the rotatable horizontal shaft, raise the horizontal shaft rotatable until the wheel deviates from the ground, communicate to the wheel and to the shaft a rotation to a   sufficient speed to make measurable forces of   equilibrium transmitted by the tree, measure the forces   equilibrium transmitted by the tree, determine imbalance data related to the measured forces and imbalance data.   2.Procédé according to claim 1, characterized in that the communication of the rotation takes place manually   and in that the speed reached is a speed not greater than greater than 180 rpm.   3.Procédé according to claim 2, characterized in that let the wheel and the shaft rotate inertia and slow down. 4.The method of determining the imbalance of a   wheel, characterized in that it comprises the operations   both to: put the wheel standing on the ground in position in the vertical assembly, vertically align a horizontal shaft   likely to turn in line with the center of the wheel and   the shaft on the wheel, mount the wheel on the rotatable horizontal shaft, raise the horizontal shaft that can rotate until the wheel moves off the ground, communicate with the wheel and the shaft rotation at a speed large enough to make measurable imbalance forces transmitted by the shaft, measure the imbalance forces transmitted by the shaft, lower the horizontal shaft until the wheel touches the ground, stopping there the rotation of the wheel.   5.Unbalance determination of a wheel, comprising a rotatable horizontal shaft (20) suitable for supporting a wheel to be balanced (25), means (34,36) for measuring imbalance forces transmitted by said wheel shaft when the wheel rotates and means (102,112) for determining and displaying imbalance data in relation to the measured forces, characterized in that means (52,54,56) are provided for adjusting the vertical position said horizontal shaft (20) to align this   shaft at the center of the wheel standing upright   and means (58,76,78) for lifting said horizontal shaft supporting the wheel to a height such that the wheel is off the ground.   Wheel imbalance determining machine according to claim 5, characterized in that it can   move horizontally to the vertical erect wheel LEMENT.   7. Machine for determining the imbalance of a wheel, characterized in that it is movable and in that the shaft   (20) which can rotate, the means for measuring   free (34,36) and the means for determining and displaying unbalance data (102-112) are located in a balancing head (8) separately mounted on a base (50)   which makes the machine mobile horizontally.   Wheel imbalance determining machine according to claim 5, characterized in that the means for adjusting the vertical position of the horizontal shaft (20) comprise a carriage (54), assigned to this movable shaft.   up and down on an amount (56).   9. Machine for determining the imbalance of a wheel   according to claim 8, characterized in that said   both (56) is parallel to the plane of the face of the wheel standing vertically and inclined on a vertical plane passing through the horizontal shaft to thereby ensure self-locking   base and its pre-load by the weight of the wheel.   Wheel imbalance determining machine according to claim 9, characterized in that said upright (56) is parallel to the plane of the face of the wheel standing vertically and inclined at 3-20 on a vertical plane passing through L horizontal shaft to lock by the weight.   11. A wheel imbalance determining machine according to claim 10, characterized in that said upright (56) is inclined at about 10 on said vertical plane. 12.Machine for determining the imbalance of a wheel according to claim 5, characterized in that it furthermore comprises means for lowering said horizontal shaft supporting the wheel, while said wheel is driven at a speed up to level o she   makes contact with the ground and stops its rotation.   13.Machine for determining the imbalance of a   wheel having a balancing head (8) which comprises   even a horizontal shaft (20) rotatable to support a wheel to be balanced, means (34,36) for measuring imbalance forces transmitted by said   when the wheel is spinning and means (102-112) of displaying   display of imbalance data in relation to the measured forces, characterized in that means (52,54,56) are provided for adjusting the vertical position of the balancing head (8) to bring its horizontal shaft (20) at the vertically upright center of the wheel (25) and means (58,76,78) for raising the balancing head with the wheel mounted on the horizontal shaft at a height   such that the wheel is off the ground.