FR2538575A1 - PIVOT TYPE CONSTRUCTION VEHICLE - Google Patents

Abstract

The pivoting type construction vehicle comprises a pivoting carriage 2 and a hydraulic motor 3 intended to drive the pivoting. It further comprises a control apparatus which operates so as to automatically reduce the flow speed or the average flow rate of the working hydraulic fluid supplied to the hydraulic motor 3, when the pivoting carriage 2 has arrived within a predetermined proximity range corresponding to one of two predetermined angular positions, to the right and to the left, in order to reduce the pivot speed in such a proximity range. The control apparatus actuates an operating valve upstream of the hydraulic motor 3, as a function of signals relating to the direction of pivoting and the amplitude of pivoting. Application to the equipment of public works machinery. (CF DRAWING IN BOPI)

Description

The present invention relates to vehicles of

  site, of the swivel type, each of which has a structure

  base, a pivoting carriage equipped with an excavating instrument, a hydraulic motor for driving the pivoting carriage pivotally relative to the base structure, and an operating valve for such a hydraulic drive. The excavation instrument of such a construction vehicle

  is supposed to repeat the work, according to alternating

  and reversible ones or passes, digging a trench

  and transfer of the earth dug from a hollow position

  trench at a loading position of a truck

  (or any other means of unloading the earth).

  Thus, it is necessary to maneuver the pivoting carriage

  equipped with the excavation instrument, so as to

  the reversible alternative stroke exactly between two angular stopping positions with respect to the basic structure, thus moving, alternatively, from one to

  the other of such given positions.

  It is common practice, during the repeated maneuver in a sequential manner and consisting in

  movement the swivel carriage equipped with the instrumentation of exca-

  and stop it, de-maneuver a valve manually.

  switching at sequential synchronization intervals

considered appropriate.

  These maneuvers and stops of a pivoting carriage have the disadvantage that there is considerable water hammer in the hydraulic system and significant impacts in the mechanical structure of the vehicle, which are caused by the high moment of inertia of the pivoting carriage and accessory elements of the latter, because the switching valve is closed in practice inevitably very fast way, which also puts the operator

  in a very uncomfortable position An additional disadvantage

  the implementation, because a great deal of experience is required in order to finally stop the pivoting carriage in exactly the angular position

  given and wanted, and because the operator is exhausted

  to properly estimate the timing of the

stop maneuver.

  In view of the present situation, as presented above, the purpose of this invention is to propose a construction vehicle of the type described above,

  and who is able to safely carry out an automatic stop

  * of the excavation instrument exactly in the position

  predetermined angularity in each of the alternative and reversible working passes or strokes, and which does not require any particular operator experience with respect to the manual operation, and which simultaneously effectively suppresses the uncomfortable vibrations at the moments of such stops; However, the vehicle is of a structure that can be constructed very economically by means of an efficient and

  are inevitably present in conventional structures.

  tional. In order to achieve this object, the swivel-type construction vehicle according to this invention is such that it has a vehicle chassis, an excavation instrument pivotally mounted relative to the chassis of the vehicle.

  vehicle, a hydraulic motor designed to rotate the

  excavation, a maneuvering valve of the type to be

  electric maneuver, able to switch the direction of operation

  of the hydraulic motor and to adjust the flow rate of the hydraulic working fluid to the hydraulic motor, a maneuvering device for

  maneuvering the operating valve, a sensor of

  to provide, at its output, information in response to the maneuvering direction and the maneuvering amplitude of the operating device, and a control mechanism for manipulating the operating valve in response to the information from the sensor, and the vehicle further comprises adjusting devices, intended to set stop positions to the right and left, respectively, with respect to the vehicle frame, positions between which the excavation instrument must move, alternatively from one to the other, like a moving shuttle

  in these successive work passes, an apparatus for detecting

  corner angle for detecting the angle of movement from left to right with respect to the vehicle frame, the digging instrument, and a control apparatus for

  to automatically operate the operating valve in positive

  flow rate reduction, when the

  from the position detection apparatus shows that the excavation instrument has arrived in a predetermined proximity range respectively from any of the stop positions, set by the apparatuses.

adjustment.

  Thus, the automatic shutdown control apparatus receives the information and processes it both with respect to the predetermined and desired angular stopping positions of the excavation instrument relative to the vehicle frame, on the one hand, and with respect to the instantaneous and detected position of the operating instrument, on the other hand, and based on this information it makes it possible to reduce the flow velocity of the working fluid supplied to the electric motor driving the instrument excavation, when the excavation instrument arrived nearby

  set and desired position, and thus stop automatically

  excavation instrument in the desired stopping position, as adjusted by means of the

  adjusting, while appropriately reducing the speed

  pivoting wall of the excavation instrument.

  therefore, no particular aptitude or experience of the

  During the manual maneuver, it is necessary to stop the digging instrument in the stop position that is desired. As this avoids any rapid and violent stop, it becomes possible to obtain

  sure a regular and smooth stop, effectively eliminating

  uncomfortable vibrations.

  The purpose of this invention is to make better use of the operating valve, which is invariably present in the conventional structure,

  to perform the automatic shutdown of the instrument of exca-

  according to this invention, and so that it is thus possible to simplify the structure with respect to what it would be in the case where a flow velocity regulator specifically provided for the automatic shutdown. Other features and advantages of the invention

  will be better understood by reading the description that will

  follow several examples of implementation, and referring to

  FIG. 1 is a side elevation and general view of the vehicle,

  FIG. 2 is a diagram of a hydraulic circuit

  for pivoting training; -

  FIG. 3 is a graphical representation showing how the moment, expressed by the angular position, of the beginning of the automatic control of the speed reduction, before stopping the pivoting, is shifted in response to the highest final angular velocity , and in level,

  FIG. 4 is a detailed graphical representation of

  showing how the pivoting angular velocity is controlled during a stroke of the pivoting movement, Fig. 5 is a block diagram of the control of the angular velocity of rotation,

  Figure 6 is a flowchart showing the function of

  of a data processor used as a

  7 is a side elevational view, partly in section, of an embodiment of a pivot angle detection apparatus also used as a component of the control, and FIG. is an elevational view, similar to Figure 7, but showing a modified embodiment

  of the angle detection device.

  FIG. 1 shows a bucket-type hydraulic excavator as a particular example of a swing-type public works vehicle, and this vehicle comprises a pivoting carriage 2 pivotally mounted on a base structure provided with a pair of suspension trains. displacement 1, right and left, of the crawler type, the carriage 2 pivoting about a vertical axis P when driven by a hydraulic motor 3 On the pivoting carriage 2 are fixed or stationary mounted a cockpit and In addition, a bucket 6 is pivotally mounted and movable on a front end of the pivoting carriage 2.

  and the bucket 6 is actually manoeuvrable by pivots-

  articulated, upwardly and downwardly, and is also pivotable or articulated in extension and retraction Further, a grader 7 is movably and pivotably mounted on a front end of the base structure, and this grader 7 is actually maneuverable by

  pivoting or articulated in elevation and lowering.

  A hydraulic drive circuit for the pivoting carriage 2 is shown in FIG.

  as can be seen, a motor 3 is connected to a hydraulic pump

  than 8 through hydraulic lines on

  which is fitted with an operating or distributing valve

  actuator 10, which can switch the movement of the operating mode of the pivoting carriage 2, by selecting one of the three alternative possibilities which are a rightward pivoting, a leftward pivoting and a stopping in this example the maneuvering distributor 10 is designed to fulfill two functions and to operate as a flow control valve as well as a maneuverable distributor for adjusting or adjusting the flow rate of the working fluid.

  hydraulic system, which is supplied to the engine 3, in proportional

  the maneuvering amplitude or the position in

  each of the respective drive modes.

  Thus, in the respective hydraulic lines leading to the operating connector of the operating distributor 10, is interposed a pair of electromagnetic and proportional valves 11, 12, which perform, in response to their input piloting pressure, the switching

  and the proportional control of the operating spool 10.

  It is thus possible to carry out the appropriate control for the pivoting drive of the pivoting carriage 2, and more precisely the control of the angular pivoting speed and the stop, by means of a command given to a controller

  13 for controlling the electronic valves

Magnetics 11, 12.

  Incidentally, 14 mechanisms have been represented

  with a brake valve installed to prevent the

  following the pivoting by inertia of the swivel car 2 at the end of the drive, while in 15 there is shown expansion valves mounted to cushion a violent stop

  or excessively forced the drive of the swivel carriage.

  The drive controller 13 is supposed to be able to execute both a controlled maneuver mode

  manually and a maneuver mode controlled automatically.

  In this example, the automatically controlled maneuver

  Furthermore, it is supposed to include automatic shutdown, while having a certain manual operation method and the actual automatic maneuver or fully automatic fully automatic maneuvering, consisting entirely of automatic processes.

  The function of the automatic shutdown is first described.

  that having a certain method of manual maneuvering.

  As shown in the upper right-hand corner of FIG. 2, the circuit comprises a maneuvering device 150, manually maneuverable by tilting from left to right in the figure, and a potentiometer 160 for detecting the operating direction of the device of FIG. maneuver

  , relative to its neutral position N and also the ampli-

  Study of the maneuver A control unit which receives such a detection information given by the potentiometer is represented in the form of a block designated by the reference 20.

  160 and maneuver, in response to such information, the

  hydraulic operating lever 10, via the electromagnetic valves 11, 12, such that, by a left swinging of the operating device, the pivoting carriage 2 is consequently pivoted to the left, that, by a swing to the right of the device 150, the pivoting carriage 2 pivots similarly to the right, and that in either direction of rotation, the angular pivoting speed is

  ordered that it be all the higher

  positive operating maneuver 150 is moved away from its neutral position N by pivoting It is thus possible to control the movement of the pivoting carriage 2 so as to pivot to the left or to the right

  bucket 6 of hydraulic excavator, according to needs.

  Still about the control apparatus 20, this

  it has sufficiently developed information storage memory means, and it operates in such a way that it determines the direction of operation of the hydraulic motor 3 and the amount of working fluid that is supplied to the hydraulic motor 3, based on of the information previously given in the memory, and also on the basis of the detection information of the operating configuration of the operating device 150, as detected by the potentiometer 160 and given in the form of its output voltage signal, and in response

  the results of such a determination, -the apparatus of

  maneuver 20 maneuver is the means of maneuver in pivoting

  to the left, which are supposed to be the electronic valve

  12, or the right-swinging actuating means, which are assumed to be the electromagnetic valve 11, so that it intermittently excites the corresponding electromagnetic valve by a train-shaped signal. pulses, while suitably modifying the repetition frequency of the pulsating signals, so as to adjust the overall excitation time interval per unit of time in exact agreement with the estimated situation,

  and has more than one previously stored information

  for a further aspect of its function at 4

  It is also possible to maneuver the maneuvering distributor, as described immediately below. Primary means mounted for such an aspect of the function are represented by the blocks 18 and 19.

  represented a sensor for detecting the pivot angle

  The pivoting carriage 2 with respect to the base structure, by means of a potentiometer In 19, there is shown generally adjustment means consisting of a first adjustment device 19a for adjusting a first standard stopping or pivoting position, relative to the basic structure, in which the pivoting carriage 2 should be stopped, for example to carry out excavation work in this position, and a second adjusting apparatus 19b for adjusting a second standard angular stopping or pivoting position, with respect to the basic structure, in which the pivoting carriage 2 should be stopped, for example to perform, in this

  position, the operation of unloading the earth removed.

  In this regard, there is shown at 120 a manual switch for switching the control unit 20 entered its state

  active or operating, in which he receives the informa-

  both the angle detection apparatus, namely the sensor 18, and the two adjusting devices 19a, 19b, and in which it carries out the control on the basis of a

  such information, and its inactive or non-operational status

  In its active or operating state, as it

  is selected by the corresponding maneuver of the inter-

  manual switch 120, the control apparatus 20 operates to automatically operate the operating valve 10 by moving it to a lateral position for reducing the flow velocity or the average flow rate when the swivel carriage 2 has arrived in a range. Proximity

  predetermined position close to the predetermined stop angular position.

  one of the two standard angular or stopping positions preset by means of the respective adjusting devices 19a, 19b, with respect to the basic structure, during a pass or of a movement race

  alternative and reversible of the pivoting carriage 2, that is,

  say of the race from the other of the two standard positions

  dard, which is thus the starting angular position in this specific race, to said position considered among

  the two standard positions, which is the angular position

  the desired stop in this race, compared to the

basic structure.

  Thus, it is possible, during a cracking

  trench or hole, during which the bucket 6 of excavator is transferred or rotated in alternating and reversible passes or courses, between a lateral position with respect to the vehicle, in which the ground is dug, and the other lateral position with respect to the vehicle,

  in which the removed soil is unloaded, and more precisely

  in each stroke in which the pivoting carriage 2 should be operated to pivot by

  relationship to the basic structure of one of its

  standard, and more precisely the starting position for this race, at the other of its standard angular positions, and more precisely the stopping position desired for

  this race, in order to transfer

  the bucket 6 of the hydraulic excavator, by such a pivoting stroke relative to the vehicle frame, to automatically stop the pivoting carriage 2 in the desired angular stopping position, as desired, as soon as the The operator started the maneuver simply by a maneuver of the manual maneuvering device 150, and, in fact, the automatic stop is obtained in a very advantageous manner, because the angular pivoting speed of the pivoting carriage 2 is automatically reduced when the pivoting carriage 2 has arrived in the preset proximity range of such a desired angular stopping position with respect to the basic structure, and, consequently, the stopping of the pivoting carriage 2 is carried out very regularly and

  softness without causing significant vibration and

fortables.

  In this example, it is assumed that the controller also has a program and information, in the form of data recorded for this purpose, to

  suitably the moment, as expressed by the posi-

  With the appropriate adjustment of this instant, it is meant that the automatic stop command is initiated when the carriage is turned off.

  swivel 2 has arrived in an angular position of

  upstream of the desired preset stop position with respect to the base structure, an angle to be set according to the highest and the highest estimated angular velocity of the pivoting carriage 2, and, therefore, the recorded program is such that it is also intended to receive an output information from an apparatus 18 'intended to calculate the instantaneous pivoting angular speed by processing the signal coming from the detection apparatus 18

  the pivot angle and, on the basis of such information,

  mation, then automatically correct the moment of the start of the stop command exerted on the actuating valve 10, so as to be properly in advance, when the highest angular speed and level of the pivoting carriage 2 becomes higher for a reason or

another.

  Figure 3 is supposed to illustrate such a modification.

  the moment of the beginning of the order, by a representative

  graphic representation on which the pivot angle O of the pivoting carriage 2 with respect to the basic structure is given on the abscissa, and the angular pivoting speed V is given on the ordinate, and in this figure, the solid line curve is assumed represent a stop command

  normal automatic, as it is initiated for the posi-

  angular representation represented in S, and the dashed line curve represents an abnormal case, in which the highest angular velocity and in step is significantly higher than

  in the normal case, so that the automatic stop command

  tick is, correspondingly, started earlier than

in the normal case.

  Consequently, it is thus possible to safely adapt to such an abnormal case, in which the angular pivoting speed becomes substantially greater than it is in the normal case, due, for example, to a abnormally corrugated ground on the work site, and to achieve, even in such an abnormal case, the appropriate automatic reduction of the angular speed of the trolley

  2, in order to perform an automatic stop, in accordance with

  table, regular and smooth, in the desired manner. By the actual implementation of this invention, it is also possible, in substitution or in addition

  pivoting the pivoting carriage 2 with respect to the structure

  base, as described above, to mount a hydraulic cylinder 3 '(as shown in Figure 1) to pivot the bucket 6 of hydraulic excavator relative to the pivoting carriage 2, or, in the case o the vehicle does not include such a carriage 2 pivoting with respect to the basic structure, to pivot any component

  relative to the chassis-vehicle, in general.

  It is needless to say that this invention can be implemented on a wide variety of construction or public works vehicles, such as, for example, excavator vehicles facing the front of the vehicle, without being limited to a vehicle with retro-caveman bucket, as

  shown in particular in Figure 1, and described above.

  above. As distributor or operating valve 10, it is also possible to use a valve which is operated, for example, by means of a servomotor and as is obvious to those skilled in the art, the particular structure of the control mechanism for to operate the valve, and to control the automatic stopping of the pivoting, can be suitably adapted, in various ways, to such

  respective modifications of the operating valve 10.

  By benefiting from the work obtained by alternative and reversible tilting races of bucket 6 excavator, it is also possible to perform,

  according to this invention, the function of the automatic stop

  of pivoting only for the races which take place

  in one particular direction, thus starting from one of the given standard pivoting angular positions, on a particular side of the vehicle, and towards the other given standard angular position, on the other

side of the vehicle.

  A rational and particular way to realize the system comprising the automatic control performing the function of automatic stopping of pivoting, as described above, so as to obtain that the pivoting carriage executes each pivoting stroke with such angular velocity that it is securely defined over the entire race from stopping at a predetermined function of the pivot angle which is supposed to be optimum to allow for as high a rotational speed as possible while still ensuring start and stop very smooth and steady of the pivoting carriage, with excellent accuracy in obtaining and maintaining the desired stopping position or target stopping position, in automatic stopping configuration, is described below with reference also to FIGS. at 6, in addition to Figures 2 and 3

  which we have already referred to above.

  As shown in FIG. 2, the distributor of

  maneuver 10 is equipped for the detection of its

  tantane of pivoting, detecting means 17 which can

  be of the type comprising a limit position switch.

  As has already been briefly described, the block 18 represents a sensor of the potentiometer type, and more precisely an angle detection sensor mounted on the rotation shaft of the pivoting carriage 2 or coupled to it.

  rotation shaft, so as to detect the pivot angle

  to the left and to the right of the carriage 2 by

  port to the basic structure so at startup, as it

  was started using the manual maneuver or

  manual control that has already been described, the control device operates to automatically manipulate the

253855?

  drive controller 13 in response to the information given by the two sensors 17, 18, such that the pivoting carriage 2 pivots with such angular velocity or which is surely defined by a predefined function of the angle of pivoting a, and that it finally stops in the stop position or target position Gf for this stroke, as has been predetermined by the adjusting means

  19 In this way, it became possible to perform very easily

  very effectively and frequently

  the pivoting carriage 2 from one to the other of the digging and unloading positions of the removed soil,

  without the need for an embarrass-

  of the angular speed of rotation and stopping.

  The graphical representation given in FIG. 4 is intended to illustrate a particular example of the automatic control of the angular pivoting speed O, during a race which should start from an angular position of beginning of pivoting OS and finish in an angular position of pivoting stop Of # the automatic control being provided by the control device 20, in the form of a predetermined function of the pivot angle from the starting position Os? for which G is consequently zero (and although the successive pivoting movements are normally repeated in alternate races).

  native and reversible, the Q value after departure is

  always considered positive and its value posi-

  G O is simply also desiged by Of)

  As can be seen, the function of this particular example

  of the case represented, indicated by the line curve

  filled in Figure 4, has sections or parts corresponding to

  are respectively laid at a step of regular acceleration, at the start of the pivoting, appearing as a section of a curve Z representing a first predetermined formula referenced -A below, a step of regular deceleration at the stop of the pivoting, appearing as a section of a

  curve m representing a second predetermined formula referenced

  found B below, and a constant speed step and.

  steady, at an angular velocity of 9 M the highest and level, suitably predetermined to perform the entire stroke quickly and yet smoothly, appearing

  as a section of a horizontal straight line N representing

  as a third predetermined formula referenced C below

* = '2 K 1 (O) (A)

  6 = 2 K 2 (f (B) 68 to M (C) in which K 1, K 2 are given constants (which, in this particular example, are assumed to be K 1 = K 2 = K), is a parameter auxiliary which is chosen to define the angular velocity in the starting position of pivoting Os and C is a given constant which is chosen to define a range of insensitivity around the stopping position

Of pivoting.

  It is assumed that these formulas A, B, C are previously recorded in the memory of the control apparatus 20, and the latter, given the information of the pivot stop position Gf and the direction of rotation given by the adjustment means 19, as well as by the sensor 17 for detecting the operating configuration, as shown in FIGS. 5 and 6, performs the operation of calculating the three respective values of G according to these formulas A, B, C using the value of the instantaneous pivot angle Q detected, which is given continuously, by the angle detection sensor 18 As is clear, FIG. 6 merely shows that the block 20 a of FIG. is a calculation processor for selecting in all circumstances the smallest value of the three Go values calculated in the aforementioned manner, and then transmitting this value as its output signal, intended to serve as a speed angular target Ai of the command

-25585? 5

  In FIG. 5, there is also shown simply by a block 20b a differentiator which receives at its input the information of the instantaneous pivot angle Q coming from the angle detection sensor 18, and which thus gives continues, at its output, the value of angular velocity

  pivoting Q detected instantly.

  As is now clear from the figure, a part delimited by a block eh broken lines

  designated c is a composition block of a correction signal

  which operates to receive the output information from both the calculation process 20a and the differentiator 20b, i.e. the speed values.

  angle of the controlled target Qi and the instantaneous detection

  9, to subtract the former from the last in order to ob-

  1 Holding the difference O e = multiplying this difference by a predetermined correction factor k in order to obtain the product O '= kgei and subtracting this product from the controlled target value O, in order finally to obtain, as output, a value of a correction signal 9 = 9 k

  (O 09) = (l + k) Qi kg, which is given as a com entry

  send to the drive controller 13.

  Thus, the drive controller 13 is automatic-

  operated so that the instantaneous and detected angular pivoting speed Q can be controlled for any values of the detected pivot angle 9, so as to be brought sufficiently close to the target value of 99, which is always -defined by such a particular formula of the three formulas

  A, B, C which then gives the lowest value i Q, that is,

  that is, to correct the instantaneous pivoting speed

  expressed by a correct answer and in correspondence with a

  such controlled target speed O, as mentioned above.

  In this way, it is thus possible, over the entire pivoting stroke, that is to say during the entire acceleration step at the start of pivoting, during any

  step at constant speed in the middle of the pivoting, and

  the entire deceleration step, when stopping the pivoting, to automatically and safely perform the control of the angular rate of rotation which is optimal for

  the respective steps, in order to obtain the pivoting carriage

  both pivots effectively and smoothly throughout its course, and that it eventually stops, with excellent

  accuracy, in the predetermined target stop position.

  It is assumed that in addition to the three formulas A, B, C, two additional formulas have been previously recorded

  in the memory of the control apparatus 20, and more precisely

  that these two supplementary formulas correspond to what is represented in FIG. 4: a curve t whose section represented in solid line corresponds to a

  regular deceleration stage at the reversible return of the

  and represents a fourth predetermined formula referenced D below, and a horizontal straight line n whose section represented in full line corresponds to a step of constant constant speed, at the highest angular speed in absolute value and in level, but of negative value OM, (the value assumed in this particular example being GM = O M '> at the reversible return

  of pivoting, and representing a fifth referenced

  E = E2 K (G + e È) (D) go 9 MK (E) where K 3 is a given constant which is chosen to define the slope of the angular velocity variation in the final step reversible return movement (and which, in this particular example, is assumed to be K 3 K 1 = K 2 = K) and its effects, in the case where the pivoting carriage 2 inadvertently performs an over-travel beyond beyond the target off position Off due to any disruption

  or for any other reason, the interoperability

  exactly as in the normal course of pivoting

  forward, as described above, are thus

  the two respective values of compliance

  to these formulas D, E, in order to always then select the Dius low absolute value of the two values of

  Get to automatically maneuver the trainer controller

  13, according to such a feedback loop principle, that the instantaneously detected angular rotational speed O can, for any value of the detected pivot angle

  G, be brought sufficiently close to the value thus parti-

  In this way, it is possible to automatically reduce the pivoting carriage 2, without requiring any manual maneuver to correct the over-stroke, the return being carried out quickly and however, smoothly to the preselected target stop position G Of in a way that is exactly the same as that described about the normal swing course to

forward.

* For sensors intended to detect the pivot angle G of the pivoting carriage 2 with respect to

  to the basic structure and intended to detect the state of com-

  mutation maneuvering distributor 10, the invention is absolutely not limited to the use of sensors of the potentiometric type or type comprising a switch of

  limit position, but it is just as possible to use

  all knownconventional types of contact or non-contact captors, and these sensors can thus, in a

  general terms, to be designated by the terms

  corner angle 18, for detecting the pivot angle

  relative to the chassis of the vehicle, and of detection apparatus

  17 of the condition of the maneuvering distributor, respectively

  is lying. Moreover, with regard to the apparatus 17 for detecting the state of the maneuvering distributor, the invention is in no way limited to the use of a device of this type.

  type that directly detects the switching state of the distri-

  maneuver scorer 10, but it is also possible to use

  any other suitable apparatus for indirectly detecting the switching state of the switching valve 10, for example by means of

  pivoting direction of the pivoting carriage 2 on the basis of the

  training provided by the angle detection apparatus 18 to give the pivot angle relative to the frame

of the vehicle.

  In addition, instead of mounting a single distributor

  10 of the type actuated by a piloting pressure

  ge, as described above, to serve both as a maneuvering distributor of the pivoting carriage 2 for switching in its rotations forwards and backwards and for its stop, and also as a calibrating maneuvering distributor of adjustable way, in order to control the angular rotation speed, the speed or the flow rate

  hydraulic working fluid supplied to the hydraulic motor

  than 3, it is also possible to mount valves

  distinct specifically for the respective functions.

  it may be obvious to those skilled in the art that the constants K 1, KVK 3 6 and MP QMI adopted in the formulas A, B, C, D, E are previously stored in the control apparatus 20, and can be selected in accordance with the special conditions

present themselves instantly.

  Now, as a particular example of the sensor 18 for detecting the pivot angle of the carriage 2, an angle detection apparatus of the type having a rotary encoder has been described below, and this apparatus is all

  first described with reference to its first mode of

  particular embodiment shown in Figure 7.

  In this figure 7, there is shown at 18 a rotary encoder adopted as a particular embodiment of the pivot angle sensor, which is operatively connected to the control apparatus 20, to give the direction and the angular speed of the pivoting swivel trolley

  2 in relation to the basic structure, "and in order to stop

  The pivoting carriage 2 in the predetermined target stop position is generally designated 110 by a speed reducer for driving the pivoting carriage 2, and this reducer comprises its output shaft 11 Oa, its cover. covering 11 Ob, and its intermediate rotational shaft 11 Oc, thus arranged

  upstream of the output shaft 11a with respect to the transmission

  As shown, the rotary encoder 18 is secured by means of a coupling 117, as one of its ends passes through the hood 11b and protrudes out of the hood 11b. ,

  on the protruding end of the intermediate rotation shaft

  It is thus possible to rotate the rotary encoder 18 by an angle proportional to the pivoting rotation angle of the pivoting carriage 2, with a proportion ratio so high that the first angle is much larger than the last. ,, in order to detect the angle

  of pivoting of the carriage 2 with a very high resolution.

  A rotary seal has been designated at 107 to provide lubrication. The particular structure of the speed reducer 110 can be suitably selected from different

  structures, and there are no restrictions or limitations

  particular with regard to the choice of the shaft which, in the speed reducer 110, upstream of the output shaft 11 of the latter with respect to the power transmission, must be adopted for which the rotary encoder 18

be fixed to him.

  FIG. 8 represents a particular form chosen from among various possibilities, with particular reference to the particular structure of the fixing of the

  rotary encoder 18 on a shaft 3a of the motor output.

  The particular structure of the rotary encoder 18 may be suitably selected from among various known structures, such as, for example, a magnetic or optical type structure, and particular means may be selected for attaching an external rotary encoder base or housing. 18 on the cover ll Ob of the speed reducer 110, and likewise a particular structure

  coupling 117 can also be suitably selected.

  between different known structures.

  In any case, it is possible to make direct use of any compact rotary encoder or small size suitable, economical and easy to find in the trade,

  simply by modifying any conventional speed reducer

  in such a way that, as described above, a rotary shaft suitably selected from among its components is extended in order to protrude from its cover and in order to fix, via a coupling, the rotary encoder on the projecting end of the shaft thus selected, while securing an external rotary encoder base or housing, on the cover of the gearbox cover In this simple way, it is possible, as this has already been mentioned above, to make effective and wise use of the function of the gearbox in order to obtain that the mobile part of the rotary encoder rotates at an angle much greater than the pivot angle of the pivoting carriage, and thus to detect the slewing angle of the carriage with a very high resolution, even if the intrinsic resolution of the encoder

  rotary can, in itself, not be very high.

  As is clear from the above, it is thus possible to give a construction vehicle excellent pivoting maneuverability, which is performed very accurately and very accurately, by the control of the automatic stop of the pivoting carriage and by detection

  meaning and amplitude of pivoting, while being

  very favorable from the point of view of the cost of

  manufacturing as well as the cost of the components.

  Of course, various modifications may be made by those skilled in the art to the devices which have just been described as non-limiting examples,

  without departing from the scope of the invention.

Claims (6)

  A swivel-type construction vehicle comprising a vehicle chassis (1), an excavation instrument (6) pivotally mounted relative to the vehicle chassis, hydraulic means of the engine and / or cylinder type (3,3 ') for to pivot the excavating instrument (6), an operating valve (10) of the electric operating type, capable of switching the direction of operation of the hydraulic means (3,3 ') and adjusting the speed   flow rate or the average flow rate of a hydraulic working fluid   driven to the hydraulic means (3,3 '), a maneuvering device (150) by means of which the operating valve (<0) is operated, a sensor (160) of the electrical type intended to give, on its output, information in response to the maneuvering direction and the maneuvering amplitude of the operating device (150), and   a control mechanism for maneuvering the sun   operating maneuver (10) in response to the information from the sensor (160), characterized in that it further comprises adjusting devices (19a, 19b) for setting right stop positions and on the left, respectively, with respect to the chassis of the vehicle, and between which the excavating instrument (6) is intended to move alternately from one to the other, such as a shuttle, during its work passes successive,   an angle detection apparatus (18) for detecting   the angle of movement to the left and to the right,   compared to the chassis of the vehicle, the instrument of exca- vation (6), and   a control apparatus (20) for self-manipulating   the operating valve (10) to move it laterally to a speed reduction position   flow or average flow rate, where the information   of the position detecting apparatus (18) shows that the digging instrument (6) has arrived within a predetermined range of predetermined mothings corresponding to any one of the stopping positions determined by the adjusting apparatus. (19 a, 19 b).   A construction vehicle according to claim 1, characterized in that the control apparatus (20) is provided with a switch (120) capable of switching the control apparatus (20) between its active or operating state and   its inactive state or non-functioning.   3 construction vehicle according to one of the claims   1 and 2, characterized in that it furthermore comprises: a device (17) for detecting the state of the valve, intended to detect the state of the operating valve (10) and to deliver information, to its output to the control apparatus (20), and wherein: the control apparatus (20) is adapted to automatically operate the operating valve (10) such that the digging instrument (6) swivels with speed   angle as defined by a predefined function   information from the apparatus (17) for detecting the condition of the valve and the apparatus (18) of angle detection.   4 construction vehicle according to claim 3, characterized in that: the chassis of the vehicle comprises a base structure (1), and   a pivoting carriage (2) pivotally mounted on the structure base course,   the excavation instrument (6) being mounted on the pivoting carriage so (2), and   the control apparatus (20) being adapted to automatically maneuver   the actuating valve (10) so that the pivoting carriage (2) pivots, with respect to the base structure (1), in a path which starts from a pivoting start position (Ga and ends in a pivot stop position (gf), with an angular velocity as defined by the function which is selected from * 2538575   the following three formulas (A, B, C) O = * '2 K 1 (O + 6) (A) Do = '2 K 2 (O) - (B) = O M (C)   where O is the pivoting angle from the starting position (O) in which O is accordingly zero, and although the successive pivoting movements are normally repeated in alternating and reversible races, the value of 0 after the start of each stroke is always considered positive, and its value in the stop position of the pivot (Of) is also simply designated by Of $ 0 is the angular velocity of pivoting in the position defined by the angle 9 , 0 is a given constant which is set as the highest selected angular velocity M of the rotary carriage (2), 6 is an auxiliary parameter which is set to define the angular velocity of the pivoting carriage (2) in the starting position of pivoting (OS) 'e is a given constant which is set to define a range of insensitivity around the pivot stop position (Of) and K 1, K 2 are data constants which are have settled so   to define the slope of the variation of the angular velocity   the initial and final stages of the pivoting run,   in such a way that the particular formula   among the three formulas (A, B, C) which gives the smallest value of 9 for the particular value of 0 at this instant <Construction vehicle according to claim 4, comprising a speed reducer (110) intended to drive the swivel carriage (2), which is mounted on the swivel carriage (2), and which has an output shaft (11 Oa), a cover (110b), and an intermediate shaft (110 Oc) , willing   upstream of the output shaft (110 la) with respect to the trans-   power projection, and one end projecting from the outside of the hood (110b), characterized in that a rotary encoder, serving as an angle detection apparatus (18), is fixed by the intermediate coupling (117) on the projecting end of the shaft   intermediate rotation (110c).   6 construction vehicle according to claim 4, comprising a speed reducer (110) for driving the pivoting carriage (2), and which is mounted on the swing truck (2) and which comprises: a cover cover (110 b) , and an input shaft (3a) which is an output shaft of the hydraulic motor (3), arranged so that one of its ends is projecting outside the hood (110b), characterized in that a rotary encoder serving as an angle detection apparatus (18) is fixed, via a coupling (17), to the projecting end of the shaft output (3 a) of the motor.