FR2779031A1 - Pendulous spraying gallery for correcting for inclined ground, - Google Patents

Abstract

The pendulous spraying gallery consists of a chassis (2), on to which is suspended a spraying gallery (5) and the device, which is designed to correct for the inclination of the ground. This correction device consists of a method of allowing the application to, at least two, separate points on the ramp of at least two forces, which are directed to pivot the gallery, in its vertical plane, so as to overcome its rotational inertia in this plane and to reduce the corresponding displacements of its centre of gravity (6).

Description

I The present invention relates to

agricultural spraying.

  It is essential to be able to maintain the parallelism of the spraying booms of such a machine with respect to the ground, in order to obtain a uniform spreading.

phytosanitary product.

  There is for this purpose a type of ramp suspension known as "pendulum", in which the ramp is suspended at the

sprayer frame.

  This type of suspension is well suited for working on horizontal ground. The presence of ruts has little influence on the ramp which remains appreciably

parallel to the ground.

  On the other hand, the pendulum suspension is ill-suited to sloping floors. Indeed, the ramp naturally tends to keep a horizontal position, it does not follow the profile of the work area. This is particularly troublesome during U-turns at the end of the field, where the slope of the ground is reversed by

compared to the ramp.

  To overcome these drawbacks, various tilt correction devices for pendulum ramps have been developed in recent years. Some of them are fully automated: we speak of pendulum ramps

  "followers". Others are manual.

  In all these devices, it has been observed that the ramp takes a certain time to reach the positions which are required of it, due to its large inertia of rotation in its vertical plane, and the parasitic displacements of its center of gravity in this plane. This is particularly troublesome in the case of manual inclination correction devices, where the delay in the reaction of the ramp disturbs the operator's appreciation: it often exceeds the inclination value which it seeks to obtain, and must thus proceed to several manipulations, to the detriment of other operations which it must perform at the same time (tracking of the trace,

height adjustment, etc.).

  The main object of the present invention is to provide a pendulum ramp assembly equipped with a ramp tilt correction device which makes it possible to reduce the reaction delay due to the inertia of the ramp and the parasitic displacements of its center.

of gravity.

  This main object of the invention is achieved with a pendulum boom assembly, comprising a frame from which is suspended a boom such as a spray boom for phytosanitary product, as well as a device for correcting the inclination of said ramp, remarkable in that said device comprises means making it possible to apply at least two distinct points of said ramp at least two forces tending to rotate it in its vertical plane so as to overcome its inertia for rotation in this plane and to reduce the parasitic displacements of its center of gravity. According to other characteristics of the invention, said inclination correction device comprises a system of links interposed between said chassis and said ramp, this system defining an articulated and deformable polygon of which at least one side is extensible and of which another side is a portion of said ramp, so that a change in the length of said extendable side causes the application of said two forces to

  said ramp at both ends of said other side.

  According to another characteristic of the invention, said rod system is connected to said chassis by a connecting rod articulated with respect to said

  system and with respect to said chassis.

  According to another characteristic of the invention, said link system is connected to said chassis by a substantially vertical guide rail. According to another characteristic of the invention, said articulated and deformable polygon is a triangle, and

  a jack constitutes the extendable side of this triangle.

  Thanks to these characteristics, the ramp can be forced to rotate in its vertical plane. In doing so, we are freed from other parasitic movements of the ramp, and we thus lessen in particular

  the swaying effects usually observed.

  With the aim also of simplifying the adjustment of the inclination of a pendular ramp, the present invention also provides means for controlling the inclination of said ramp to the instructions given by

a control panel.

  Thanks to these characteristics, a semi-automatic servo system is obtained, constituting an excellent compromise between the fully

  automated and manual currently existing.

  Other characteristics and advantages of the present invention will appear on reading the

  description which follows and on examination of the attached drawing

  in which: - Figure 1 is a rear view of a pendulum ramp assembly equipped with a tilt correction device according to the invention, during a spraying operation on a substantially horizontal ground; - Figure 2 is a view of the boom assembly of Figure 1, during a spraying operation on sloping ground; - Figure 3 is a block diagram of a servo loop of the ramp tilt correction device; - Figure 4 shows a control panel of the tilt correction device; - Figure 5 shows an actuating cylinder

  the boom equipped with a position sensor.

  We refer to Figures 1 and 2 of the accompanying drawing in which we can see the structure of the assembly of

pendulum ramp according to the invention.

  In these figures and the following, identical reference numerals represent organs or

identical or analogous elements.

  The pendulum ramp assembly according to the invention

  comprises a frame 1 having the form of a rigid frame.

  Typically, this chassis 1 is intended to be fixed vertically to the rear of an agricultural machine such as a tractor which can be seen in Figures 1 and 2 the rear axle 2 and the rear wheels 3, 4 placed on a ground S. A spraying boom 5 is suspended from the chassis 1 by a rigid or flexible link such as a chain 6. Preferably, the suspension of the boom 5

  takes place at its center of gravity 7.

  A first link 8 is articulated on the part

  upper central 9 of the ramp 5.

  A second link formed by a V cylinder (preferably hydraulic) is articulated on both

  the first link 8 and on the part 9 of the ramp 5.

  This link system defines an articulated and deformable triangle, one side of which is extendable and

  of which another side is a portion of the ramp 5.

  This link system is connected to the chassis 1 by a link rod 10, articulated at the same time on the

  first link 8 and on the chassis 1.

  In a possible variant and not shown, the connection between the first link 8 and the frame 1 could be obtained with a substantially vertical guide rail fixed to the frame 1 and in which the first link 8 could both slide and pivot. When the length of the jack V varies, the ramp 5 is subjected to two forces applied at two points distinct from its upper part 9: - a first force is applied by the hydraulic jack V to one of the ends of the ramp portion forming one of the sides of the aforementioned triangle, - a second force is applied by the first link 8 to the other end of this portion of the ramp. These two forces impart to the ramp 5 a movement of forced rotation in its vertical plane, which we have been able to realize, during various tests, that it made it possible to reduce the parasitic movements of the ramp, and thus s to overcome the rocking problems encountered with the suspended ramps of the

prior art.

  We now refer to Figure 3, on which we can see a block diagram of a servo loop of the correction device

ramp inclination 5.

  As can be seen in this figure, the control loop includes a control panel C, allowing a tilt instruction to be sent to the ramp. A CE electronic card allows the control panel C to be interfaced with a hydraulic distributor D. This hydraulic distributor actuates the jack V making it possible to rotate the ramp 5 in its vertical plane. A position sensor CP coupled to the cylinder V makes it possible to measure its length and therefore the inclination

  effective of ramp 5 with respect to chassis 1.

  This position sensor CP returns the measurement of the length of the jack V to the electronic card CE, which compares this measurement with the setpoint set by the control panel C. As long as this measurement is not substantially equal to the setpoint, l tilt adjustment continues

automatically.

  Reference is now made to FIG. 4, in which a possible embodiment of the control panel C has been shown. As can be seen in this figure, this control panel comprises: - a light-emitting diode 15 intended to indicate that the ramp 5 is instructed to tilt to the left, - a light-emitting diode 16 intended to indicate that the ramp 5 is instructed to tilt to the right, - a setpoint button 17, - a button 18 to recall the heading 0 (neutral position or the ramp is instructed not to tilt either to the right or to the left with respect to the chassis 1) and for commissioning, - a rocker switch 19 for selecting the tilt to the left or right in manual or slave mode. On power-up, regardless of the position of the setpoint button 17, the inclination correction device operates in manual mode, and an action on this setpoint button has no effect: a safety device is thus obtained which makes it possible to avoid movements

untimely ramp 5.

  To put the servo into service, it is necessary to maintain an action on the button 18 for a predetermined duration, typically of the order of a few seconds. This predetermined duration constitutes a safety delay, preventing the unexpected starting of the servo system. We then enter the slave mode, and the ramp 5 is automatically placed at heading O. The diodes 15 and 16

are both on.

  We can then select an inclination side of the ramp 5 by giving an impulse on one side

  toggle switch 19.

  The LED corresponding to the selected side lights up, and the other goes off. Ramp 5 then tilts to the selected side and to the value given by setpoint button 17. The value of the inclination of ramp 5 can be modified by changing the position of setpoint button 17. At any moment, we can recall the ramp 5 at heading 0 by pressing the button 18, without having to

  modify the position of the setpoint button 17.

  The recall of the ramp 5 to heading 0 is for example useful when the agricultural machine supporting the ramp arrives

at the head of the field.

  After making a U-turn, you can tilt the ramp symmetrically from left to right or vice versa by simply tilting

switch 19.

  As we can now understand, the control panel C makes it possible to very easily correct the inclination of the ramp 5, in particular at the headland

  o the operator must focus on other tasks.

  Finally, reference is made to FIG. 5, in which the actuator V equipped with its position sensor CP has been shown. As can be seen in this figure, the position sensor CP comprises a housing 25 fixed to the cylinder 26 of the jack V. This housing comprises a pulley 27 mounted on the axis

a rotary potentiometer 28.

  A constant force spring 29 (such as a spiral band spring) is fixed on the rod 30 of the cylinder V and is

  intended to wrap around the pulley 27.

  A protective member 31 makes it possible to prevent the penetration of dirt into the housing 25, as well as the formation of frost on the part of the spring 29 which is

  intended to be wound on the pulley 27.

  Each inclination of the ramp 5 corresponds to one and only one angular position of the potentiometer 28. Thus, by measuring the voltage on the cursor of this potentiometer, we can deduce the value of this

tilt.

  Of course, the invention is not limited to the embodiments described and shown which have not been

given as an example.

  Thus, for example, the system of links defining a triangle described above could be replaced more generally by an articulated and deformable polygon of which at least one side would be extendable and of which another side would be a portion of the spraying boom. By way of illustration and without limitation, the link system could define a parallelogram, two parallel sides of which could be extended, the third side of which would consist of a portion of the spray boom, and the fourth side of which would consist

  by a portion of the upper part of the chassis 1.

  It is thus also that one could imagine a system of rods conforming to the precepts of the invention making it possible to apply forces to the ramp

  spray in addition to two points.

Claims (10)

  1. Pendulum ramp assembly, comprising a frame (1) to which is suspended a ramp such as a spraying boom for phytosanitary product (5), as well as a device for correcting the inclination of said ramp, characterized in that that said device comprises means making it possible to apply at least two distinct points of said ramp (5) at least two forces tending to rotate it in its vertical plane so as to overcome its inertia for rotation in this plane and to reduce the parasitic displacements of its center of gravity (6).   2. pendulum ramp assembly according to claim 1, characterized in that said inclination correction device comprises a system of rods (8, V) interposed between said frame (1) and said ramp (5), this system defining a articulated and deformable polygon of which at least one side (V) is extensible and of which another side is a portion (9) of said ramp (5), so that a modification of the length of said extensible side (V) causes the application of said two forces to said ramp (5) to both ends of said other side.   3. pendulum ramp assembly according to claim 2, characterized in that said link system (8, V) is connected to said chassis (1) by a connecting rod (10) articulated relative to said   system (8, V) and with respect to said chassis (1).   4. Pendulum ramp assembly according to claim 2, characterized in that said link system is connected to said chassis (1) by a rail of substantially vertical guidance.   5. Pendulum ramp assembly according to one   any of claims 3 or 4, characterized in   that said articulated (8, V, 9) and deformable polygon is a triangle, and in that a jack (V) constitutes the side extendable from this triangle.   6. Pendulum ramp assembly according to one   any of the preceding claims, characterized in   that said inclination correction device comprises means (C, CE, D, CP) for controlling the inclination of said ramp (5) to the given instructions by a control panel (C).   7. pendulum ramp assembly according to claim 6, characterized in that said control means (C, CE, D, CP) comprise means   (18) for automatically recalling said ramp (5) to heading 0.   8. pendulum ramp assembly according to claim 6, characterized in that said control means (C, CE, D, CP) comprise means (19) for automatically tilting said ramp (5) symmetrically from left to the right, or vice versa. 9. pendulum ramp assembly according to claim 6 when it depends on claim 5, characterized in that said servo means (C, CE, D, CP) comprise a position sensor (CP)   for measuring the length of said cylinder (V).   10. Pendulum ramp assembly according to claim 9, characterized in that said position sensor (CP) comprises a constant force spring (29) fixed to the rod (30) of said cylinder (V) and intended to be wound around a pulley (27) mounted on the axis of a rotary potentiometer (28) fixed on the cylinder (26) of said cylinder (V).