FR2660950A1 - RETRACTOR SHOVEL WITH IDLE DISPLACEMENT NEAR THE DRIVER. - Google Patents

Abstract

The invention relates to a backhoe. It relates to a backhoe comprising a boom (6), an arm (8) and a bucket (9). According to the invention, a control device has on the one hand a function of inhibiting the movement of the boom (6) and of the arm (8) in the pick-up direction when the bucket (9) is inside it. 'a lateral danger line and the arm (8) is inside a front danger line with respect to the section comprising the driver, and on the other hand a delay function according to which the arrow (6) and the arm (8) are moved, in the direction of the pickup, at a speed calculated according to the distance between the arm (8) and the front danger line, so that the bucket decelerates as it approaches the driver . Application to backhoes.

Description

The present invention relates to a backhoe

  type, which includes a swivel platform, a

  section for the driver and mounted on the platform

  a shovel assembly laterally disposed with respect to the section of the conductor and comprising an arrow, an offset mechanism, carrying an arm having a bucket at one end, a driving device for the shovel assembly, a attitude detection, a device

  operating mechanism, and a control device.

  In this type of backhoe, a digging operation is performed while the excavator assembly is unfolded, and the earth dug and transported by the excavator assembly is unloaded on the tray of a truck placed behind the excavator For this purpose, the pivoting platform is turned after folding of the shovel assembly, that is to say after delimitation of a

  space allowing rotation of the pivoting platform.

  In particular, in a cluttered area, the shovel assembly is often folded and unfolded in the manner previously indicated. When the shovel assembly is folded to be brought closer to the pivoting platform region.

  particular, the bucket is moving closer to the section of the

  For example, a backhoe as described in Japanese Patent Application Publication No. 1989-198621 has been proposed which includes controls which prevent the bucket from being moved closer together.

  of the driver's section for safety.

  In the known backhoe, a bucket position with respect to the section of the conductor is calculated from the angle of devotation of the boom relative to the pivoting platform, the pivot angle of the arm relative to the arrow, and lateral displacement amplitude

  of the bucket with respect to the inner end of the boom.

  When the bucket has entered a danger zone

  around the driver's section, the bucket is slowed or stopped so that an abnormal approach to the

  section of the driver is avoided.

  However, when using such a

  when the boom assembly is folded towards the driver's section to be close together, the bucket often enters the danger zone as a result of a maneuvering error or following a position overrun by Inertia As a result, when an operation

  excavation carried out in front of the excavator and an opera-

  The rearward unloading arrangement is repeated at a congested location, the folding of the shovel assembly to the position adjacent to the section of the conductor, which is necessary for small radius rotation, is very inefficient. The invention relates to the realization of a backhoe of the aforementioned type which allows the folding of a shovel assembly so that it is close to the

  the driver's section, with a yield and accuracy

position that are increased.

  More specifically, the invention relates to a backhoe excavator of the type described above, and such that the control device has a function of inhibiting the movement of the boom and the bucket arm in the direction of pickup when the bucket is in position. inside by

  relative to a lateral danger line delimited lateral-

  with respect to the driver's section, on the

  find the shovel set, and the arm is in the

  with a forward danger line defined in front of the driver section, and also has a delay function allowing the boom and bucket arm to move in the pick-up direction at a speed calculated by use as a parameter. , from the distance between the bucket arm and the forward danger line, so that the bucket which approaches the section of the driver

undergoes a deceleration.

  In this backhoe, when the bucket, that is to say the bucket arm, moves towards the section of the driver, the bucket or the arm is close to the driver and the cylinder of the boom, the cylinder of the arms

  and / or the shifting mechanism moves slowly.

  With this decelerating control, the bucket arm and the bucket attached to its forward end are also slowed down so that precise position adjustment is facilitated. Even if the bucket enters the danger zone and an instruction is made. stop is transmitted, the bucket can be stopped immediately, given the low

  speed of movement Obviously, the function of decelerating

  If the bucket is in the danger zone, it is not used when the bucket deviates from the driver's section.

  quickly leave the danger zone.

  This allows a safe execution of an operation accompanying the driver's section bucket approach. Another advantage is that the danger zone can be set to a minimum width so that it

  gives a relatively large work area.

  In a preferred embodiment of the invention, the shovel assembly is movable to a close position in a region of the pivoting platform by shifting the bucket arm relative to the boom and folding the boom and boom. bucket arm so that the bucket is placed at a location adjacent to one side of the boom This construction allows the backhoe to dig the land forward and unload it on a truck placed behind, even at a location that leaves little space in

  more than that which is necessary for the rotation of the platform.

  pivotal shape In this case too, high efficiency and

  great precision is obtained for the folding of the

seems to shovel.

  Other features and advantages of the invention

  will be better understood by reading the description

  which will follow examples of embodiment, with reference to the accompanying drawings in which: Figure 1 is a side elevational view of the backhoe excavator; Figure 2 is a plan view of the shovel assembly; Figure 3 is a side elevational view showing the excavator assembly in the retracted position; Figure 4 is a plan view showing the shovel assembly in the retracted position;

  FIG. 5 is a block diagram of a

  seems to control the backhoe; Figures 6 to 13 are flowcharts illustrating the control operations; and FIGS. 14A and 14B are schematic views respectively in plan and in lateral elevation, indicating

the definition of the danger zones.

  The backhoe excavator shown in FIG. 1 comprises a tracked chassis 2 having a pusher blade 1 and a pivoting platform 4 mounted so that it can rotate on the tracked chassis 2. The pivoting platform 4 carries a section 3 intended to a driver,

  an engine E and an arrow assembly 5.

  The arrow assembly 5 has an arrow 6 constituting

  The arrow 6 has an end hingedly supported at a location of the pivoting platform 4 placed laterally with respect to the section 3 of the conductor, and it can pivot vertically under the control of a boom cylinder Cl. As shown in Figure 2, the arrow 6 has an internal member 6a acting as a main post, an external member 6b and an offset mechanism This shift mechanism comprises an intermediate member 6c connecting the organ external 6 b to the internal member 6 a so that it can pivot about a vertical axis More precisely, a connecting rod 7 is arranged parallel to the intermediate member 1 Oc between the internal member 6 a and the external member 6b, and it is articulated on arms 7a and 7b connecting rod supported by

  the inner member 6a and the outer member 6b respectively.

  The arms 7a and 7b, the rod 7 and the intermediate member 6c

  constitute a parallelogram shift mechanism.

  Thanks to this construction, a cylinder C 4 of offset

  the displacement of the outer member 6b of the boom is substantially parallel, in the direction transverse to the inner member 6a of the boom As a result, a bucket arm 8 connected to the outer member 6b of the boom has a parallel displacement, that is to say that it is shifted transversely to the inner member 6 has the bucket arm 8 can pivot vertically relative to the inner member 6a under the control of a jack C 2 of arms The bucket arm 8 carries a bucket 9 fixed at its outer end so that it can pivot vertically under control

a cylinder C 3 cylinder.

  In this construction, the arm 8 or the bucket 9 can be laterally offset from the vehicle so that it undertakes a trenching operation along an outer side edge of the frame 2 The entire boom assembly 5 can be housed inside a place of rotation of the pivoting platform 4 by shifting outwardly of the arm 8, lifting of the boom 6 and folding of the arm 8 and the bucket 9 In this state, as 3, and as shown diagrammatically in FIG. 4, the boom 6, the arm and the bucket 9 retract towards the pivoting platform 4, the bucket 9 being placed laterally with respect to the arrow 6, on the side opposite to that of section 3 of the driver This state allows a rotation movement in a reduced space and is called "approach state for small radius turn". The jib assembly 5 and the pivoting platform 4 may be controlled by a device 10 placed in the

  conductor section The control device 10

  takes a pair of levers 10 a and l ob right and left of

  command that can tilt transversely, that is,

  say from front to back and sideways, and a lever 10c

offset.

  Figure 5 is a block diagram of a

  control unit of the backhoe according to the

  As shown, the control assembly includes a first sensor 51 and a third sensor 53 which are potentiometers for detecting the control positions of one of the levers Oa, depending on the length and width of the platform. 4, and a second sensor 52 and a fifth sensor 55 which are potentiometers for detecting the control positions of the other control lever l Ob, according to the length and width of the pivoting platform 4 The states of control of the shift lever l C are detected by a fourth sensor 54 The detection signals from these sensors are transmitted to a control unit 11 formed

  essentially a microcomputer.

  The control system further comprises an arrow distributor Vl connected to the boom cylinder Ci, an arm valve V 2 connected to the arm cylinder C 2, a bucket valve V 3 connected to the bucket cylinder C 3, a distributor V 4 offset connected to the cylinder C 4 offset, and a distributor V 5 pivoting connected to the motor M of

  each of these distributors is a distributor.

  The control unit 11 controls the distributor control circuits D1 to D5 which are connected to the boom valves V1, V2 of the arms, V3 of the bucket, V4 of the offset and V5. When the control lever i Qa is operated according to the length of the pivoting platform 4 for example, the control unit 11 transmits a signal to the control circuit D1 according to the result of the detection given by the first sensor If and different control modes so that the distributor Vi of the boom is maneuvered accordingly, the cylinder Ci arrow is operated essentially in one direction and at a speed corresponding to the control position of the lever l Oa De

  same, when the control lever i Oa is moved manually-

  To the side, the control unit 11 transmits a signal to the control circuit D 3 according to the result of the detection given by the third sensor 54 and different control modes, so that the bucket valve V 3 is Maneuvered accordingly, the bucket cylinder C 3 is controlled substantially in the direction and with a speed which correspond to the control position of the lever Oa. When the lever 1 Ob is operated according to the length of the pivoting platform 4, the control unit 11 transmits a signal to the control circuit D 2 according to the result of the detection given by the second sensor 52 and various modes. of control, so that the distributor Vl of the arm is operated accordingly, the cylinder C 2 of the arm is controlled essentially in one direction and with a speed

  which correspond to a lever control position l Ob.

  When the control lever 1b is manually moved to the side, the control unit 11 transmits a signal to the control circuit D 5 according to the result of the detection of the fifth sensor 55 and various control modes, so that the distributor V 5 pivoting is controlled Accordingly, the motor M pivoting is controlled in one direction and with a speed that correspond to a lever control position l Ob A lever operation l Oc offset is transmitted to the unit similarly, and, following the transmitted signal, the control unit 11 switches the shift valve V 4 via the control circuit D 4 so that the shift cylinder C 4 is operated by DETAILED DESCRIPTION As described in detail hereinafter, the control unit 11 determines whether the actions of the jacks, depending on the maneuvers of the various levers, are desirable or not from the point of view of safety and function. For example, unwanted orders are canceled or changed. FIG. 1 represents various sensors intended to capture the attitude of the boom assembly, i.e. the positions of the members constituting the boom assembly, and to transmit it to the control unit 11 More precisely, a boom angle sensor P1 is mounted at the inner end of the jack C1 so that it detects the pivot angle of the boom 6 with respect to the pivoting platform 4. arm is mounted at the outer end of the boom 6 so that it detects the pivot angle of the arm 8 relative to the arrow 6. A bucket angle sensor P 3 is mounted on a connecting rod 12 connecting the jack C 3 of the bucket to the bucket 9 so that it detects the pivot angle of the bucket 9 relative to the arm 8, the pivot angle of the rod 12 relative to the arm 8 being detected as the angle of the bucket furthermore, an offset sensor P 4 is mounted on the arrow 6 so that it detects the pivot angle of the intermediate member mediates 6c with respect to the internal member 6a and obtains an offset amplitude comprising a direction of offset of the bucket 9 relative to the internal member 6a of the arrow These sensors

  are preferably rotary type potentiometers.

  As indicated in FIG. 5, output signals from the sensors P1 to P4 are transmitted to the control unit 11. As a result, the control unit 11 recognizes the attitude of

the arrow set 5.

  The control assembly further comprises a switching

  59, a bending mode switch 56, an offset return switch 57, and an upgrade mode switch 58, constituting switches of the control modes of the boom assembly. all of which are connected to the control unit 11 As described in more detail below, the danger prevention mode is intended to prevent dangers such as the abnormal approach of the bucket with respect to the section 3 of the driver as a result a deflection or shift control of the boom assembly 5 The hazard prevention mode is normally

  The folding mode is intended to automati-

  the boom assembly 5 of the working position,

  in front of the pivoting platform 4, to the state of

  small-radius rotation, as previously indicated The shiftback refers to an automatic reset which is performed upon return

  of the set 5 with arrow of the reconciliation state allow-

  both a small radius rotation to the working position of the bucket 9 in offset position in which the bucket is before the approach operation The leveling mode is intended to control the folding of the boom 6

  and the arm 8 during the automatic reconciliation of the

  appears to arrow 5 so that a bucket 9 opening plan

remains practically level.

  We now describe a control sequence of the backhoe, including the boom assembly,

  According to the invention The following description contains the

  expressions "direction of collection" and "direction of discharge" to indicate the directions of operation of the elements which determine the angle of the boom assembly 5 "direction of pick-up" means the direction in which the bucket is guided so that it disintegrates and collects the earth The "direction of spill" refers to the direction in which the bucket is guided

so that it pours a load.

  When the backhoe begins to be used, the program shown in FIG. 6 begins for the control unit 11 After checking the parameters and initializing the variables, various operations are performed in timeshare.

  operations are carried out in the form of

  performed at predetermined intervals of time.

  These interrupt operations include a process

  principal, a process of capturing signals from potentials

  meters, an input process of the various control mode switches, a display process on a control panel, and a process of transmission to the control circuits of the distributors In the main process, the operating amplitudes of the various devices of backhoe excavator training are determined from the various control modes in the process of

  capture of sensor signals, the signals of potential

  meters constituting the sensors are accepted and transformed into forms that can be used in the main process In the process of entering

  control mode switches, switching signals,

  the control modes are accepted and transformed into the forms used in the process.

  and the necessary preparations are carried out

  For example, when the bend mode switch command is confirmed, the offset amount

  detected at that moment is stored in a predetermined zone.

  of direct access memory In the display process

  display, all the data displayed on the

  control placed in the driver section are set.

  In the process of transmitting signals to the control circuits of the distributors, control signals are

  applied to the appropriate circuits for controlling the

  scorers according to the range of maneuvering of the cylinders

  determined and preserved in the main process.

  The main process is now more precisely described. Referring to Figure 7; when the main process begins, a control mode prepared in the process of entering the switches of the control modes is accepted in step 10 Then the data entered from a control lever or the like, prepared during the input process sensors, are

  accepted in step 15 The range of distribution maneuver

  The result of the calculation is written in a predetermined area of direct-access memory. In addition, associated angular data of the boom, bucket arm, and bucket, prepared in accordance with FIG. During the process of capturing sensor signals and representing the attitude of the boom assembly, are accepted in step 30. At the following steps, various control modes are checked: step 40 determines whether offset control mode is set or not and, in the case of a positive response, step 45 is executed so that it invokes a shift control routine. Likewise, steps it, 60 and 70, verify the control mode of setting.

  level, the folding control mode and the mode of com-

  and, if these modes are set, corresponding subprograms are called in steps 55, 65 and 75.

  As a result, an amortization control process

  and a hazard prevention process are performed.

  In these control mode programs and the processing programs, the range of operation of the distributors is updated if necessary. The amplitude of operation of the distributors written at this moment constitutes the basis of creating a control signal to be transmitted to a distributor control circuit in the transmission process of

  signals to the control circuits, which constitutes a

  As a result of this signal, the distributor control circuit transmits a suitable current to the associated distributor, and finally

controls the corresponding cylinder.

  We now describe the subroutines called by

the main process.

  Figure 8 is a flowchart of the shift control After checking the direction of shift in step

  , a suitable value is drawn from a table of

  In step 120, the offset lever command data stored in the predetermined area of the memory. Then, a control amplitude used in the control circuit associated with the controller.

  offset cylinder is calculated and written in step 130.

  Figure 9 shows a flow chart of the

  At first, at steps 210, 220, and 230, the actual angles of the bucket, arm, and boom are calculated from the data prepared in the sensor input process at step 240, a bucket angle relative to the vehicle frame is derived from these angles, and a deviation f relative to a reference angle

  leveling the bucket opening plan is calculated.

  The absolute value of this deviation is compared with a tolerance range d A at step 250 If the difference falls within the tolerance range, the bucket control is omitted (step 260) Furthermore, a control gain corresponding to the detected bucket angle is determined in step 270 A bucket control amplitude is derived from the control gain and

  the difference f at step 280, and is written in a predetermined zone

mined from memory at step 290.

  Figure 10 is a flowchart of the order of

  folding or matching In this program, a check

  step 305 determines the presence of an arrow lowering or arm moving instruction in the direction of the spill. If such an instruction is present, the program jumps to step 395 to immediately cancel the bend command. This means a stop of the folding command in progress following a decision following the determination that an operation contrary to the folding command was performed when the operator manipulated a lowering control lever. If the response is negative at step 305, the program proceeds to step 310 and determines the control amplitude of the arrow at a maximum value upwards, and the control amplitude of the bucket arm has a maximum value in the direction of pick-up Then, the height of the bucket with respect to the ground is calculated in step 315 If the height exceeds one meter, steps 320 to 350 are exec utes

  so that the offset control amplitude is deter-

  If not, the offset command is dangerous so that the offset control amplitude is not determined for the bend command. When adjusting the amplitude of the offset command, the offset angle is first compared to a target value in step 320 so that the fact that the offset command has to be

  performed to the right or to the left be determined.

  If the offset angle exceeds the target value, a shift to the right is required. Next, the shift control amplitude is determined at a maximum value on the right at step 325 and a shift direction flag is raised to the right at not 330 If the offset angle is less than

  the target value requires a shift to the left.

  Then, the amplitude of the shift control is determined at the maximum value to the left at step 340, and the

  shift sense flag is raised to the left at step 350.

  Then, the step 360 is executed so that it determines if the arrow is in the approaching position, that is to say if the angle of the arrow is at its maximum. If the answer is affirmative, the amplitude of the Also, step 370 is executed to determine whether the bucket arm is in the inbound position, i.e., if the angle of the boom is set to a zero value in step 365.

  bucket arm is at maximum If the response is posi-

  In this case, the amount of adjustment of the arm is set to a value of zero in step 375. Then, step 380 determines whether or not the offset adjustment is completed. The right shift command is terminated if the offset angle is less than the target value The left shift control is completed if the offset angle exceeds the

  target value If it is determined that the order of

  the time is over, the amplitude of the shift control

  is rewritten to zero in step 385 Then step 390 determines

  whether or not the arrow assembly is in the near position by determining the zero adjustment of the offset control amplitude, the arrow control amplitude and the control amplitude of the control arm.

  bucket If the boom assembly is in the close position

  step 395 is executed so that it cancels the instruction

  folding command and the command command of

  upgrade that started with the folding command.

  FIG. 11 is a flowchart of the shift feedback control. In this program, a change of the bend mode switch from the absence of control to the presence of control is confirmed during the process of entering the various switches of the control modes. After order

  this confirmation, a detected value of offset, is

  that is, an offset value of the forward arrow set is read in the predetermined memory area at step 410. This read offset is read against a currently detected offset value at step 420 if the bucket must be moved

  to the right to return to the staggered position

  If the bucket is to be moved to the left, the offset control amplitude is set to the maximum value on the left at step 440. offset return is complete when the

  detected value of offset is equal to the previous value

  offset (not 440) The return command from

  offset is then canceled at step 450.

  Although not specifically described herein, it is possible to provide a plurality of offset value storing zones at a bending moment, and a selector switch of one of these values that is read at the same time. 410 This allows the bucket to

  return to a desired shift position after an operation

  It is also possible to memorize not only one or more offset positions but also

  the angle of the boom, the angle of the arm and the angle of the bucket.

  So, the arrow set can be restored to the attitude

  he had before the folding operation.

  Figures 12A and 12B show a flowchart

  damping control Shocks can be advantageous

  be dampened by reducing the speed of the piston near the ends of the stroke when driving the boom, arm and shift cylinders used in the boom assembly.

  intended essentially for controlling the jacks

  so that the speed of movement of the pistons

  reduced near the ends of the race.

  The boom cylinder is checked first If the boom cylinder is driven in the end of stroke area or in the upward direction of the boom (step 500

  and 505), the distance at the end of the race is calculated

  based on the detected angle of the arrow, and a predetermined optimum value of control of the arrow is derived from the calculation result (step 510). This optimum value is determined so that the operating speed increases proportionally with the distance to the control. end of the race for example The value thus derived is used for the rewrite of the amplitude of control of the arrow in step 515 The cylinder of the arm of the bucket is then checked If the

  bucket arm jack is piloted in the area of the former

  tremity of the race and in the sense of pickup (not 520

  and 525), the distance at the end of the race is calculated

  based on the detected angle of the bucket arm, and a predetermined optimal bucket arm control value in the pick-up direction is derived from the calculation result (not

  530) The value thus derived is used for the rewriting

  The bucket arm cylinder is then checked in the discharge direction. direction of the spill (steps 540 and 545), a distance at the end of the stroke is calculated from the angle

  detected from the bucket arm, and a predetermined optimum value

  the control arm of the bucket in the direction of

  is derived from the result of the calculation (not 550) The value

  thus derived is used for the rewrite of the ampli-

  control study of the bucket arm at step 555 Similarly,

  560 to 595 are executed to ensure

  damping stroke of the shift cylinder in the end regions of the stroke, for the shift movement to the right and to the left respectively This control sequence corresponds to that of the cylinder of the arm and

  we do not repeat his description.

  Then a damping command is performed for the shift cylinder C 4 This control decelerates the displacement of the shift cylinder C 4 near a target position so that the cylinder stops accurately at the target position When the bucket is moved to the left by the shifting mechanism, the bucket may exceed the target position under the action of the inertial force or the like In some cases, the bucket may come into contact with the driver's section and may be dangerous Serious The deceleration operation is performed during the displacement to the left of the bucket so that this

situation is avoided.

  The principle of the danger zones delimited around the section of the conductor is now described, with reference to FIGS. 14A and 14B. FIG. 14A represents the danger zones around the backhoe A first danger line

  before FL 1 is determined in advance of the conductor section.

  and a second danger line before FL 2 is deter-

  mined forward of the first danger line before FL 1.

  A first lateral danger line SL 1 is determined on the right side of the driver's section and a second lateral danger line SL 2 is determined outside the first lateral danger line SL 1 The danger zones delimited by the lines of danger before are intended to

  prevent the bucket from being brought closer to the

  The danger zones delimited by the lateral danger lines are intended to prevent the bucket from being brought closer to the driver's section on the right. In addition, as shown in Figure 14 B, a corner limit zone the arrow is further determined in the space before the section of the conductor The conditions are determined for the ascent of the arrow when it is in the angular range Z delimited by

the lines VL 1 and VL 2.

  We go back to the damping command; the

  sequence starting at step 600 is a deceleration operation

  ration intended to avoid a danger in the control of the shift mechanism This operation is carried out so that the possibilities of displacement of the bucket, under the control of the cylinder C 4 offset, more to the left than a set position during the folding of the together

arrow are minimal.

  First, step 600 determines whether the shift mechanism is shifted to the left or not. Only if the answer is positive does the program step to step 610

  to determine if the folding command is in progress.

  When the folding command is in progress, step 620 is executed and determines whether the bucket is towards the interior of the second lateral danger line SL 2 Only in this case is the deviation from a target value is

  derivative of a current offset position and a posi-

  predetermined target shift, the latter being an offset position in which the boom assembly is bent, and the offset is used as a parameter for determining the amplitude of the offset deceleration control (step 630) L offset control amplitude

  thus determined is used for the rewriting of the

  stored altitude of the shift control at step 640.

  If step 610 determines that the folding command is not present, step 650 is executed to determine whether the bucket is inward of the second lateral danger line SL 2 and the bucket arm is found within the second danger line before FL 2 Only in this case is a deviation from a target value derived as previously indicated and is

  used as a parameter for the determination of the

  study of the deceleration deceleration control (step 630).

  The amplitude of the shift control thus determined is used for the rewriting of the control amplitude of

  memorized shift in step 640 If the above conditions

  If dentes are not filled, the damping command is interrupted without rewriting the stored amplitude of

the shift control.

  The danger prevention control is now described with reference to FIG. 13 This control is also used with the danger zones represented in FIGS. 14A and 14B. In the type of backhoe according to the invention, pivoting upwards of the boom and pivoting in the direction of picking up the bucket arm causes the bucket to move forward towards the section of the conductor, and a bucket offset movement involves moving the bucket from a position to the right towards the bucket conductor section The hazard prevention control therefore prevents the upward pivoting and pivoting of the bucket arm in the pick-up direction in the forward danger zone, and the offset movement to the left in the picking zone. Lateral danger In addition,

  the hazard prevention control includes the delimitation

  a deceleration zone outside the second danger line before FL 2 so that the operation

  corresponding cylinders be slowed down according to the

  arrow and arm to the danger zone.

  In the hazard prevention control, when the control instructions of the boom assembly are transmitted by operation of the control levers l0a and l0b and shift lever l oc, the attitude of the boom assembly, that is, positions and direction of movement

  different elements of the boom assembly, is calculated

  Based on the detected data concerning the angle of the boom, the angle of the arm and the offset amplitude that are then available. When these positions and directions pose problems, the operating amplitudes of the corresponding jacks are reduced or, if necessary, a rewrite to a null value For example, if the bucket is inside the second lateral danger line SL 2 and if the arm is inside the first danger line before FL 1 the left shift movement is canceled If the bucket is inward of the first lateral danger line SL 1 and the arm inside the second danger line before FL 2, the pivoting of the arm in the direction of collection is canceled If the bucket is inside the

  first line of lateral danger SL 1, the arm in the

  of the second danger line before FL 2, and the angle of the arrow in the angular range between lines VL 1 and VL 2, the pivoting of the upward arrow is also canceled. If the bucket is at inside the

  second lateral danger line SL 2 and the arm in the

  second line of danger before FL 2, the fact that

  the boom and bucket are in the deceleration zone

  The distance, ie the distance to the danger zone, is calculated and a deceleration operation is executed accordingly. More specifically, in the program shown in Fig. 13, step 700 determines whether the bucket is inward of the second lateral danger line.

  SL 2 If the answer is no, this program is

  broken since the hazard prevention control is not necessary If the bucket is within the second lateral hazard line SL 2, step 705 is executed to determine whether the bucket arm is at the inside of the second danger line before FL 2 If the bucket arm is outside the second danger line before FL 2, the principle of the deceleration zone, indicated previously, is introduced Thus, step 710 determines, where applicable, the control amplitude of the bucket arm from the distance of the arm to the danger zone,

  for the current angle of the arrow, and the amplitude of the

  the direction of the arrow according to the distance from the arrow to the danger zone, for the current angle of the bucket arm At step 715, the respective control amplitudes are rewritten with the values determined previously If the bucket arm is located inside the second danger line before FL 2, bucket, arm and boom operations are canceled in the following sequence, if

  appropriate, according to their positions.

  First, if the bucket arm is inside the first danger line before FL 1 (step 720) and the left shift command is in progress (step 725), the command amplitude offset is rewritten to a null value (not 730 and 735) Then the offset command determined before the start of this program is canceled. Then, if the bucket is within the first lateral danger line SL 1 (step 740) and the arm moves in the pick-up direction (step 745), the arm control amplitude is rewritten to a null value (not 750 and 755) Thus, the control of the bucket arm

  set before the start of this program is canceled.

* Finally, if the angle of the arrow is in the angular range delimited by the lines VL 5 and VL 6 (step 760), the bucket is located inside the first lateral danger line SL 1 (step 765). ) and the arrow is raised (step 770), the control amplitude of the arrow is rewritten to a zero value (steps 775 and 780) Thus, the arm control determined before the start of this program

is canceled.

  The preceding process cancels the command which causes a reconciliation of the boom assembly, and in particular of the bucket, of the section of the driver of a

dangerous way.

  In this way, the control amplitude initially determined by the control lever i Qa or Ob or the shift lever 1 Oc is reduced or canceled, if necessary, by the damping or damping control program.

  danger prevention control The final value results

  aunt is used in the process of transmission of control signals indicated above so that the control circuits and consequently the distributors are maneuvered With this method, priority is given to the control amplitude of the jacks drawn from a program of control. following processing Depending on the construction of the boom assembly and the stroke of the cylinders, the deceleration control amplitude calculated in the hazard prevention control program may exceed the control amplitude calculated in the previous damping program by

  example In order to avoid this inconvenience, a condi-

  can be determined for the rewriting of the data so that a value can not be replaced by a

larger value.

  Of course, various modifications may be made by those skilled in the art backhoe excavators which have just been described as examples not

  limiting without departing from the scope of the invention.

Claims (1)

1 Backhoe excavator, of the type which comprises: a pivoting platform (4), a section (3) for a conductor and mounted on the pivoting platform, a shovel assembly (5) placed in a region arranged laterally relative to the section of the conductor, the shovel assembly comprising an arrow (6) connected to the pivoting platform so that it can pivot vertically, an offset mechanism (7) connected to the boom so as to it allows a horizontal offset movement with respect to the boom, a bucket arm (8) connected to the shift mechanism so that it can pivot vertically, and a bucket (8) connected to the front end of the bucket arm so that it can pivot vertically, a device (Cl-C 4) driving the boom assembly for controlling the various elements of the boom assembly, a device (P 1-P 4) for detect the attitude of the shovel set, the dispositi atti- tude detector comprising a boom angle sensor (P1) for detecting the swing angle of the boom; an offset sensor (P4) for detecting the offset amplitude of the boom mechanism; offset transversely to the bucket arm, a bucket arm angle sensor (P 2) for detecting the pivot angle of the bucket arm, and a bucket angle sensor (P 3) for detecting the bucket arm angle pivoting angle of the bucket, an operating device (10) for gripping the operating amplitudes of the various elements of the shovel assembly, and a control device which is controlled by the operating device (10) and which is for controlling the shovel assembly (5) via the shovel assembly driving device, the control device being for calculating the positions of the boom, arm and bucket with respect to the driver section from a signal from the angl sensor arrow, an offset sensor signal, an arm angle sensor signal, and a bucket angle sensor signal, characterized in that the controller has: (1) a function of inhibiting the movement of the boom (6) and the bucket arm (8) in the pick-up direction when the bucket (9) is inwardly of a lateral danger line delimited laterally by relative to the driver's section, on the side where the shovel assembly is located, and the arm (8) is located within a forward danger line delimited in front of the section of the conductor, and 2) a delay function for moving the boom (6) and the bucket arm (8) in the pick-up direction at a speed calculated by using, as a parameter, the distance between the bucket arm (8) and the forward danger line so that the bucket (9) decelerates as it approaches the section of the driver. Backhoe excavator according to claim 1, characterized in that the delay function of the control device (10) is obtained by using a deceleration substantially inversely proportional to the distance between the bucket arm (8) and the danger line before when this distance is less than a predetermined value, the deceleration being zero when this distance exceeds the predetermined value. Backhoe excavator according to one of the claims   1 and 2, characterized in that the shovel assembly (5) is movable to a close position in the region of the swivel platform (3) by shifting the bucket arm (8) relative to the boom ( 6) and folding the boom and the bucket arm so that the bucket (9) is placed close to a bucket side of the arrow.