FR2843677A1 - Verge grinder machine comprises tool connected by two arms forming deformable quadrilateral with coupling head carried by self-propelled vehicle, first arm comprising master actuator and second arm integrating slave actuator - Google Patents

Abstract

The machine comprises a tool (GB) connected by two arms (B1,B2) forming a deformable quadrilateral with a coupling head (3) carried by a self-propelled vehicle (2). The first arm comprises a master actuator (VA) with an active chamber (CHA) and the second arm is connected to the control branch (BC) integrating a slave actuator (VB) with an active chamber (CHB). A hydraulic connection (LH) fitted with a pressure threshold valve (SAS) connects the active chambers. The contact of an obstacle (O) on the tool forces a modification of the length of the master actuator and the opening of the valve and an exchange of hydraulic liquid with the slave actuator controlling the pivoting of the second arm.

Description

Field of the Invention The present invention relates to an agricultural machine

  comprising - a tool connected via two arms forming a deformable quadrilateral 5 to a coupling head carried by the self-propelled vehicle to allow the position of the tool to be adjusted as a function of the surface to be worked, - a branch of length control adjustable by an integrated cylinder

  in this branch, connecting two movable points one with respect to the other of the deformable parallelepiped to adjust the position of the tool.

  Such machines or devices are coupled to a self-propelled machine and they generally work with an offset relative to the direction of travel. This offset is more or less important depending on the surface to be worked and the adjustment of the offset is done by transverse displacement with possibly modification of inclination relative to a

  horizontal plane of the machine tool.

  This tool can be a mowing bar or a shredder, in particular a verge shredder. The function of such an apparatus is to grind weeds, refuse, brambles, a lawn at the edge

  of road, path, edge of fence, etc ...

  Usually, such a machine is coupled to an agricultural tractor or, more generally, a self-propelled machine.

  According to a known embodiment, the position of the tool 25 relative to the machine to which it is coupled is modified by two arms

  constituting an articulated quadrilateral connecting one end to the coupling part of the self-propelled vehicle, the other end carrying the tool itself.

  Such a machine is shown diagrammatically in FIG. 1 showing an agricultural shredder 1 or known shoulder shredder,

  connected via a coupling head 2 to the coupling 3 of a self-propelled vehicle 4 shown very schematically. At the location of the coupling, between the coupling head 2 and the coupling means 3 of the vehicle 4, there is also the output of the PTO, not shown, connected, for example 35 folded, by a connection to gimbal to the crusher to drive its mechanism.

  The grinder 1 consists of a grinding group GB, the structure of which, which is not important for understanding the present invention, will not be described. This GB grinding group is connected by a sup-

  port fitted with a pivot 5 with an axis parallel to the longitudinal axis XX, at the coupling head 2 by two arms, a first arm B1 and a second arm B2 connected to the coupling head at the articulation points SI1, S4 and to the support 6 of the pivot 5 by the joints S2, S3. The arms B1, B2 form, with the coupling head S2 and the support 6, a deformable quadrilateral whose vertices

  are formed by the articulation points S 1, S2, S3, S4.

  Two points movable relative to each other in this deformable quadrilateral are connected, for example the articulation S1 is connected to a point of articulation S5 of the opposite arm B2 by a branch of control BC, provided with a jack V. The length of the control arm BC is adjustable by jack V, which changes the position of pivot 5 by

  relative to the coupling head 2 by deforming the quadrilateral S1-S4.

  To control the orientation of the group GB around the pivot, the support 6 is connected to the grinding group GB by a jack V1.

  In this known mill, the first arm B1 has a

  spring R, integrated into the arm and allowing it to lengthen.

  When the grinding group GB encounters an obstacle O, the latter retains the grinding group GB which deforms the articulated quadrangle by lengthening the spring R until the group pivots and glides around the obstacle. Then, the group is brutally recalled by the

  spring R in the normal transverse position, such as that shown.

  Thus, the articulated quadrilateral system makes it possible to position the grinding group either in the axis of advancement of the vehicle or with offset by movement of the quadrilateral to move the tool or the grinding group more or less on the side of the vehicle. by tilting it

  possibly to follow the terrain profile.

  The risk is the meeting of obstacles such as a stake, a

  rock, a tree, which can strike the shredder violently and damage the entire machine.

  In the known machine described above, the spring R allows the tool to reverse while the vehicle and the machine continue to move but this movement is insufficient if the tractor advances rapidly. In addition and as already indicated, the return after the passage of the obstacle is a sudden movement which can cause a shock dangerous for the mechanics, in particular the cardan shaft ensuring the transmission of the movement between the PTO of the vehicle self-propelled and

  the tool inlet and the arms carrying the tool.

  OBJECT OF THE INVENTION The object of the present invention is to develop a machine of the type described above, equipped with a tool which can be offset more or less strongly alongside the vehicle towing or carrying the tool, for allow the latter to dodge the obstacle smoothly, without sudden repercussion on the support and / or drive mechanism of

machine tool.

  Object and advantages of the invention To this end, the invention relates to an agricultural machine of the type defined above characterized in that - the first arm comprises a master cylinder, integrated into the arm, in which the piston defines a chamber active, - the second arm is connected to the control branch incorporating a slave cylinder in which the piston defines an active chamber, - a hydraulic connection controlled by a threshold lock connects the active chamber of the master cylinder to that of the slave cylinder, the contact of an obstacle on the tool producing, from a traction, greater than the threshold of the bolt, the opening of the bolt and an exchange of hydraulic liquid with the slave cylinder controlling the pivoting of the second arm in the direction of tool clearance from the obstacle. Thus according to the invention, when the tool encounters an obstacle, in particular what is the most frequent case, when the tool is in the offset position, this contact with the obstacle triggers from a certain threshold 25 of effort, the movement of movement of the tool by the deformation of the

  articulated quadrilateral carrying the tool and amplification of the movement.

  This contact of the tool with the obstacle produces a double reaction amplifying the disengagement movement: - on the one hand, the change in length of an arm, that carrying the master rin vé30 which allows a certain pivoting of the tool retained by the obstacle and - on the other hand, this change in arm length controls a

  change in shape of the deformable parallelepiped by displacement of the other arm, which accentuates the movement of pivoting and disengagement of the tool to make it pass next to the obstacle.

  By choosing the stroke of the master cylinder and that of the slave cylinder, the movement of the tool is defined by pivoting and by lateral displacement.

  The ratio of movements between the master cylinder and slave cylinders depends in particular on the ratio of the sections of the pistons of the two cylinders as well as on the position of the articulation point of the branch

  on the second arm of the articulated quadrilateral.

  According to an advantageous characteristic, in the normal operating position, the piston of the master cylinder and the piston of the slave cylinders are in the retracted position. This results in a first type of

  deformation of the articulated quadrilateral.

  According to another advantageous characteristic, in the normal operating position, the piston of the master cylinder is retracted and the

  piston of the slave cylinder is deployed.

  This corresponds to a second type of deformation and movement of the articulated quadrilateral. Depending on the geometry of the articulated quadrilateral and the dimension ratios between the sides of the quadrilateral, we will choose one or the other solution, also taking into account the importance of the lateral offset of the tool relative to the vehicle which door.

  According to an advantageous characteristic, the threshold lock is a pressure threshold valve the opening of which is controlled by an induced pressure in the master cylinder, greater than the threshold of the valve (SAS).

  This is a hydraulic version of a threshold lock controlling the hydraulic communication between the master cylinder and the slave cylinder.

  According to another advantageous characteristic, the threshold lock consists of a mechanical lock installed as a bypass of the master cylinder (VA), connected to each of the parts of the first arm on either side of the master cylinder; the spring of the mechanical lock adjusting the opening traction threshold, so that a traction exerted on the first arm 30 by an obstacle and exceeding a threshold, produces the opening of the lock and the

  release of the master cylinder movement to send hydraulic fluid to the slave cylinder.

  It is a mechanical version of the threshold cylinder controlling the communication or exchange of hydraulic fluid between the master cylinder and the slave cylinder.

  According to another advantageous characteristic, the mechanical spring lock is constituted by a cam connected to the first part of the first arm and a spring-loaded cam follower connected to the second part of the first arm, the passage of the cam follower on the cam when the tensile force exerted on the cam follower is greater than the resistance

  created by the spring and applying the cam follower against the cam.

  Although the invention can be applied to many agricultural machines, advantageously the control branch connects the articulation of the first arm to the coupling head at a point of articulation

of the second arm.

  According to another advantageous characteristic, the agricultural machine is an agricultural crusher, in particular a verge crusher lo comprising a tool in the form of a grinding group connected by means of a pivot with a longitudinal axis to the deformable quadrilateral, a jack connecting the pivot support belonging to one side of the deformable quadrilateral in the grinding group to adjust its inclination around

the pivot axis.

  The invention is particularly advantageous in the case of such an agricultural machine because the pivot connecting the tool, that is to say the grinding group to the articulated quadrilateral, is an element which can be damaged by a brutal impact of the tool against an obstacle, especially if the

  self-propelled vehicle moves quickly.

  The risk is all the greater as this type of device treats surfaces such as road shoulders often cluttered with objects of an unpredictable nature and particularly dangerous for the shredder. Drawings The present invention will be described below in more detail with the aid of embodiments shown schematically in the accompanying drawings in which: - Figure 1 schematically shows a known agricultural crusher installed behind a self-propelled vehicle, - the Figure 2 is a diagram of a crusher according to the invention in the operating position, - Figure 3 shows the dodging movement of the crusher according to the invention encountering an obstacle, - Figure 4 shows the return movement of the crusher after the passage 35 to the right of the obstacle, FIG. 5 shows the kinematics of another embodiment of the crusher according to the invention,

  - Figure 6 shows another variant of the invention.

  Description of embodiments

  The description of the agricultural machine according to the invention will be made below in the case of an agricultural crusher, in particular a shoulder crusher in which the tool is constituted by a grinding group

  whose structure will not be described precisely.

  In the case of such an agricultural machine, it is necessary not only to move the tool transversely relative to the direction of the self-propelled vehicle such as the agricultural tractor, but also to adjust its inclination as a function of the surface to be worked, in particular if this 10 surface is a low side of the road that you have to work in elevation.

  In the case of such a tool, work is normally done behind the vehicle, in the extension thereof and more frequently partly behind the vehicle and partly offset. This offset can be more or less important depending on the surface to be worked. If this surface 15 is worked in several passes, the offset will be modified according to the

passages of the machines.

  The difficulties mentioned above, in particular the meeting of obstacles, are more frequent when the apparatus works in offset.

  Indeed, the driver of the vehicle carrying the device looks at the lane located in front of the vehicle but he may not see obstacles located at

  side of the lane that the vehicle is following or at least, he cannot observe the areas located next to and in front of the vehicle with the same attention as he observes the path that the vehicle must follow.

  Due to this offset work, the tool is often naturally offset relative to the vehicle and the point of attachment of the tool to the articulated quadrilateral is not necessarily in the middle of the tool in its

transverse direction.

  FIG. 2 shows an agricultural crusher 100 according to the invention, connected to the coupling means 3 of a self-propelled vehicle 4 by its coupling head 2. The means for rotating the group of

  GB grinding is not shown.

  The transverse tool constituted by a grinding group GB is connected by a pivot 5 carried by a support 6 to the two arms BI1, B2 themselves connected by their other end to the coupling head 2. The ends 3 of the arms Bi1, B2 are connected by joints Si1, S4 to the head

  coupling 2 and by the joints S2, S3 to the support 6 of the pivot axis 5.

  The grinding group GB is also connected to the support by a jack VI1 which controls the pivoting of the group GB around the axis 5.

  The grinding group GB is, in general, fixed near one end to the pivot axis 5 because the grinding group GB works mainly on one side of the self-propelled vehicle 4, for example, the side

right as shown.

  The entire vehicle 4 and the crusher 100 moves in

  the direction of travel represented by the arrow DM.

  The arms B1, B2 form, as indicated above, a quadrilateral with the coupling head 2 and the support 6. This quadrilateral is represented by a deformable parallelogram whose width has been managed to facilitate the representation of the constituent elements of the mill.

  In reality, the parallelogram, or more generally, the deformable quadrilateral, is relatively narrow.

  The first arm B 1, preferably the arm located on the active side of the mill (here, the right side), is equipped with a VA cylinder constituting a vé15 rinmaître. The control branch BC which connects two mobile points of the quadrilateral S1, S2, S3, S4, for example the articulation point S1 to the second arm B2 by the articulation S5, comprises in addition to the jack VC controlling the deformation of the articulated quadrilateral , also a VB cylinder constituting a slave cylinder. The piston PA of the cylinder VA defines, in the cylinder CA, an active chamber CHA. Likewise, the piston PB delimits, in the cylinder CB of the cylinder VB, an active chamber CHB. The active chamber CHA of the cylinder VA is connected to the active chamber CHB of the cylinder VB by a hydraulic connection LH controlled by a threshold lock which opens the hydraulic connection only if the arm B1 is subjected to a tensile force exceeding a certain threshold. In this example, this lock

  threshold is constituted by a SAS threshold valve which authorizes an exchange of hydraulic fluid between the active chambers CHA, CHB only if the pressure prevailing in the active chamber CHA exceeds a certain threshold (depending on the direction of the exchange of the hydraulic fluid , the threshold can be passed up or down to open the SAS threshold valve).

  In the case of the example shown, the active chamber CHA is normally filled with hydraulic fluid, the piston PA occupying the high position as shown and the active chamber CHB of the cylinder VB

is of reduced volume to the minimum.

  For the description of the dodge movement of the group of

  grinding, it is assumed that the grinding group encounters an obstacle O1.

  The different positions of this obstacle are represented according to the principle of relative movement between the obstacle and the grinding group on the LO line. At a first instant, the obstacle is in position 01 then the advancing crusher, the obstacle occupies the relative position 02 in contact with the grinding group GB. From this moment, the dodging movement shown schematically in FIG. 3 is triggered. The obstacle 02 retains the grinding group GB so that the arm B1 is forced to lengthen the length AL1 (FIG. 3) by extension of the jack VA as soon as the tensile force exerted on the first arm B1 generates in the active chamber CHA of the jack VA, a pressure of 10 passing the pressure threshold of the valve SAS, the latter opens and liquid hydraulic is discharged through the valve to the active chamber CHB of the cylinder VB, the piston of which is thus pushed back in the direction AL2, which lengthens the control arm BC. This elongation produces the pivoting of the second arm B2 around the articulation S4 thus causing the support 6 (side S2, S3 of the deformable quadrilateral), which comes in the position S2 ', S3' and the grinding group in the position GB '' so as to

  clear obstacle 02 to pass by it.

  Thus, in summary, the traction exerted by the obstacle in position 02 on the first arm B 1 via the grinding group 20 GB and the support 6 of the pivot 5 produced from a certain force threshold or pressure, an exchange of hydraulic fluid from the active chamber CHA of the master cylinder VA to the active chamber CHB of the slave cylinder VB and the latter controls the movement of the arm B2 by pivoting, in the direction of release of the grinding group GB . The pivot angle ca of the arm B 1 to its new position shown in broken lines and the pivot angle of the arm B2 also to its new position shown in broken lines are different. The swing angle of the GB grinding unit between

  the first position and the dodge position GB ′ are marked with the reference y.

  Depending on the width of the tool in the transverse direction, the importance of the offset with which the tool can work, we will define the geometry of the articulated quadrilateral and, in particular, the stroke of the cylinders, that of the master cylinder and that of the slave cylinder, as well as the ratio of the sections. The same applies to the triggering threshold of the 35 threshold valve which must take into account the greater or lesser fragility of the tool carried by the articulated quadrilateral to control the movement.

  dodging more or less quickly from contact with the obstacle.

  FIG. 4 shows the return movement of the grinding group GB 'and of the arms BI', B2 ', after passing over the obstacle in position 03 to return to the normal working position.

  For this, the device comprises an end stop 5 BU against which the arm B2 rests which allows the quadrilateral to be put into its normal shape after the passage of the obstacle. In fact, the CHV1 chamber of the jack VC is supplied with hydraulic liquid in order to push the piston PB of the slave jack VB and discharge the hydraulic fluid from the active chamber CHV of the jack VB into the active chamber CHA of the jack VA until returning in the normal position of the cylinders VA, VB in FIG. 2.

  It should be noted that depending on the distance at which the obstacle is located relative to the axis of movement of the machine, the GB tool will rest more or less on the obstacle which will cause more or less deformation. less of the arm Bi and of the quadrilateral Si, S4; thus the BI arm will not always come into contact with the

BU stop.

  This does not prevent the execution of the movement described above. The supply to the jack VC will first produce the displacement of the arm B2 in abutment against the stop BU then the movement of return to the normal position of the quadrilateral and of the tool GB. FIG. 4 shows the various movements by arrows: firstly, the thrust movement exerted by the jack VC bearing on the stop BU which pushes the piston PB of the slave jack VB according to arrow F1; - the piston PB moves in the chamber CHB in the direction of arrow F2 and - discharges the hydraulic fluid through the connection LH in the direction of arrow F3 through the threshold valve SAS as soon as the pressure exceeds the threshold valve adjustment; - The liquid thus discharged arrives in the chamber CHA of the master cylinder VA and moves the piston PA in the direction of the arrow F4 which shortens the arm S1, S2 (arrow F5); - These translational movements also result in pivoting or rotational movements - on the one hand, a rotation movement of the apex S3 in the direction of the arrow F6 and - on the other hand, a rotation movement F7 of the arm SI1, S2 combined with

its retraction movement.

  These various movements restore the grinding group GB to its normal operating position as shown in solid lines in FIG. 2.

  Figure 5 shows another embodiment of a machine according to the invention. In this variant, the active chamber CHBO of the slave cylinder VB is located on the side of the piston PB producing a retraction of the length of the control branch BC when the first arm B 1 o0 is stressed in traction by an obstacle encountered by the group grinding

  GB as described above. In this case, the hydraulic fluid discharged from the active chamber CHA from a certain pressure threshold opening the valve SAS through the hydraulic connection LH, arrives in the active chamber CHBO of the slave cylinder VB to push back the piston PB 15 in the direction -AL2 causing the retraction of the control branch BC. This pivoting movement returning from the joint S3 towards the position S3 'accentuates the pivoting of the grinding group GB' with respect to the movement leaving the joint S3 shown in FIG. 3.

  Figure 6 shows another variant of the agri20 cole machine according to the invention. In this variant, the same references were used as for the first embodiment to designate the same elements. The description of these elements will not be repeated in full.

  In this second embodiment, the threshold lock is constituted by a mechanical spring lock VER installed in derivation of the

  VA master cylinder. This lock is connected by its ends to each of the parts B1 11, B12 of the first arm B1. this connection is shown very schematically by supports A1, A2.

  The lock itself is shown very schematically as being composed of two parts, a first part forming a CAM cam carried by a rod T1 connected to the support A1 and a second part formed by a rod T2 connected to the T2 support and carrying a CCAM counter-cam cooperating with the CAM cam. The CCAM cam follower is recalled by a RS spring defining a release threshold for the lock.

  When the elongation force exerted by the obstacle not shown on the grinding group GB exceeds a certain threshold, on the arm B1 and partly on the part B12 of this arm, the cam follower CCAM exceeds the resistance exerted by the RS spring and passes over the CA cam. The master cylinder VA is then free to discharge liquid through the hydraulic circuit from its active chamber CHA to the active chamber CHB of the slave cylinder VB. The movement is then carried out as for that controlled by the threshold lock constituted in the first example by a SAS threshold valve. The restoration of arm B1 in its normal position after the passage of the obstacle is done under the same conditions because the jack V then pushes the hydraulic fluid from the active chamber CHB of the slave jack VB to the active chamber CHA of the master jack VA, which then retracts the arm B1 and causes the CCAM cam follower to pass over

  the CAM cam in the locked position.

  Different mechanical embodiments are possible for the mechanical lock described and shown diagrammatically in FIG. 6.

  It should also be noted that this threshold lock, in its mechanical form, is applicable both to the version of the machine, and more precisely to the production of the first arm B 1 of FIG. 2 as that of

Figure 5.

  Finally, in a manner not shown, to avoid sealing problems at the level of the cylinders VA, VB, it is advantageous that not only the active chambers CHA, CHB are filled with liquid.

  hydraulic connected by a hydraulic link LH, but also that the second chambers of these jacks (chambers not referenced) are in communication with hydraulic fluid, independently of the hydraulic communication between the active chambers CHA, CHB so as to balance the pressures on the part and other of each of the pistons PA, PBE.

  This hydraulic connection applicable to the various embodiments described above has not been shown for the purpose of

simplification of the drawings.

Claims (7)

R E V E N D I C A T I ONS   1) Agricultural machine comprising - a tool connected by means of two arms forming a deformable quadrilateral to a coupling head carried by the self-propelled vehicle to allow the position of the tool to be adjusted as a function of the surface to be worked, - a length control branch adjustable by a jack integrated in this branch, connecting two movable points relative to each other of the deformable parallelepiped for adjusting the position of the tool, 10 characterized in that - the first arm ( B1) comprises a master cylinder (VA), integrated into the arm, in which the piston (PA) defines an active chamber (CHA), - the second arm (B2) is connected to the control branch (BC) integrating a cylinder -slave (VB) in which the piston (PB) defines an active chamber (CHB), - a hydraulic connection (LH) controlled by a threshold lock (SAS) connects the active chamber (CHA) of the master cylinder (VA ) to that (CHB) of the slave cylinder (VB), the contact of a obstacle (O) on the tool (GB) producing, from a traction, greater than the threshold of the lock, the opening of the lock (SAS) and an exchange of hydraulic fluid with the slave-cylinder (VB) controlling the pivoting of the second arm (B2) in the direction of release   of the tool (GB) relative to the obstacle (O).   2) agricultural machine according to claim 1, characterized in that the threshold lock (SAS) is a pressure threshold valve (SAS) whose opening is controlled by a pressure induced in the master cylinder (VA), higher at the valve threshold (SAS). 30 3) Agricultural machine according to claim 1, characterized in that the threshold lock is constituted by a mechanical lock (VER) installed in derivation of the master cylinder (VA), connected to each of the parts (B1 11, B12) of the first 35 arm (B1) on either side of the master cylinder (VA), the spring (RS) of the mechanical lock (VER) regulating the opening traction threshold, so that a traction exerted on the first arm ( B1) by an obstacle and exceeding a threshold, produces the opening of the bolt (VER) and the release of the movement of the master cylinder (VA) to send liquid hydraulic to the slave cylinder (VB).   4) Agricultural machine according to claim 3, characterized in that the mechanical spring lock (VER) consists of a cam (CAM) connected to the first part (B 1 1) of the first arm and a cam follower (CCAM) spring (RS) connected to the second part (B12) of the first arm (B1), the passage of the cam follower (CCAM) on the cam (CAM) taking place when 1o the tensile force exerted on the counter cam (CCAM) is greater than the resistance created by the spring (RS) and applying the cam follower against the cam (CCAM, CAM).    ) Agricultural machine according to claim 1, characterized in that in the normal operating position, the piston (PA) of the master cylinder (VA)   and the piston (PB) of the slave cylinder (VB) are retracted.   6) Agricultural machine according to claim 1, 20 characterized in that in the normal operating position, the piston (PA) of the master cylinder (VA)   is retracted and the piston (PB) of the slave cylinder (VB) is deployed.   7) Agricultural machine according to claim 1, 25 characterized in that the control branch (BC) connects the articulation (S 1) of the first arm (B 1)   at the coupling head at a point of articulation (S5) of the second arm (B2).   8) Agricultural machine according to claim 1, 30 characterized in that   the second chambers of the cylinders (VA, VB) are connected by a free hydraulic connection for the exchange of hydraulic fluid between these chambers in the opposite direction to that of the active chambers (CHA, CHB) of these cylinders (VA, VB).   9) An agricultural machine such as an agricultural shredder, in particular a shoulder shredder according to claim 1, characterized in that it comprises - a tool in the form of a grinding group connected by means of a pivot (5) of longitudinal axis to the deformable quadrilateral, - a jack (V1) connecting the support (6) of the pivot (5) belonging to one side 5 of the deformable quadrilateral to the grinding group (GB) to adjust its   inclination around the axis of the pivot (5).    ) Agricultural machine according to claim 1, characterized by an end-of-travel stop (BU) against which the second arm (B2) bears to push back, by the adjustment cylinder (VC), the hydraulic fluid of the   slave cylinder (VB) to the master cylinder (VA).