EP0989245B1 - Control device for an earth-moving machine - Google Patents

Abstract

The control system for a self-propelled civil engineering vehicle with working implements consists of one circuit with control levers (10) for the movement of the chassis, and another with a tilting console (3) and handle (2) for the hydraulic circuit controlling the implements. It has a locking mechanism for the control levers (10) which is actuated automatically by a spring (45) when the console is pivoted into its retracted position and comprises a cable (40) linked to the console, and a mechanical relay (20) with a locking member on one arm which engages with a notch (16) in the lever end.

Description

Technical area

The invention relates to the field of public works machinery. More specifically, it relates to an improvement of the control device prohibiting the unintentional actuation of the gear drive controls when the driver has left his driving position.

Previous techniques

As is known, a public works machine is generally equipped with a self-propelled chassis and work equipment. The driving position includes a number of controls to control the movement of the machine on the ground and the deployment and orientation of the work equipment. The control device thus has a control circuit in translation of the self-propelled frame, actuated by the movement of articulated levers which can be in the form of manual manipulators, and / or pedals located at the floor of the driving position. This control circuit actuates, by means of a set of linkages or cables, the control of the hydraulic propulsion motor (s) and the rotation of the various axles or tracks, possibly in a differentiated manner from one side to the other of the machine .

Moreover, the driver has at his disposal a number of manipulators acting on the hydraulic circuit of the various cylinders mounted on the work equipment. These manipulators also allow, in the case where the machine has a pivoting turret, to rotate it relative to the self-propelled chassis.

Accidental or unintentional maneuvers of work equipment and / or turret can be expected to cause significant damage when not controlled. Therefore, no unexpected movement of the turret or work equipment shall take place when the driver has left the driving position. Thus, most current gear is equipped with a device for locking the controls of the work equipment when the driver leaves the driving position.

In practice, the various manipulators controlling the hydraulic circuit of the work equipment and the turret are mounted on a console located laterally relative to the driver. When he wants to leave the seat of the driving position, he must pivot or retract the console carrying the manipulators to get off the machine.

In known manner and as described in DE-A-197 29 873, the retraction movement or pivoting of the console causes, thanks to an appropriate member, the cutting of the hydraulic control circuit of the work equipment and / or turret. In this way, as long as the driver is outside the driving position, it is impossible for the work equipment to unfold unexpectedly.

A problem to be solved by the invention is that of ensuring complete safety by avoiding any unexpected control of the hydraulic motor or motors of the chassis when the driver has left his driving position.

It has already been proposed to solve this problem of equipping the control levers in translation locking systems by a mechanical system of pivoting fork that the driver must fold down on the lever before leaving his machine. Unfortunately, such a device is independent of the cut-off device of the hydraulic circuit of the work equipment, and unlike the latter, the driver must perform a deliberate operation to lock the controls in translation.

It is therefore easy to see that such a solution is extremely imperfect, because it does not prevent the driver from being forgotten and does not provide total safety.

Presentation of the invention

• un circuit de commande en translation du châssis automoteur, actionné par le mouvement de leviers articulés ;
• un circuit de commande hydraulique de l'équipement de travail, actionné par au moins un manipulateur monté sur une console apte à pivoter entre une position de travail et une position escamotée, le circuit hydraulique étant équipé d'un organe apte à le couper lorsque la console pivotante passe en position escamotée.

The invention therefore relates to a control device of a public works machine comprising a self-propelled chassis and work equipment, presenting:

• a control circuit in translation of the self-propelled chassis, actuated by the movement of articulated levers;
• a hydraulic control circuit of the work equipment, actuated by at least one manipulator mounted on a console capable of pivoting between a working position and a retracted position, the hydraulic circuit being equipped with a member adapted to cut when the pivoting console goes into the retracted position.

This device is characterized in that it further comprises means for blocking the movement of the articulated levers of the control circuit in translation, said means being actuated when the pivoting console goes into the retracted position, even in the case where the control levers are in a position different from the neutral position, said means being capable of ensuring the blocking of the movement of the levers as soon as they move to the neutral position.

In other words, the invention consists in ensuring the locking of the levers or control pedals in translation when the driver raises the console carrying the control manipulators of the work equipment. In this way, when the driver prepares to get out of his machine, he automatically locks both the two control circuits of the equipment working and moving the machine, in a single maneuver that he is obliged to realize if he wants to get off the driving position. This blocking of the movement of the control levers in translation is independent of the very nature of the control circuit in translation which can be done by linkage, cable, or even by an electrical or hydraulic circuit.

According to the invention, in the cases where the driver lifts the console and the levers are not exactly in the neutral position, but in a slightly engaged position, the locking means are nevertheless actuated, but produce their positive effects locking the levers as soon as the levers are in the neutral position. It is therefore impossible for the driver to leave the machine in a state where the control lever is slightly engaged, which results in a movement of the machine as soon as the power circuit is restarted, since the simple contact of the lever it ensures passage through its neutral position, and therefore according to the invention to its locking in position.

• un mécanisme de commande des moyens de blocage, actionnés par le pivotement de la console, et comportant, à proximité des leviers de commande en translation, un élément dont la position est fonction de la position de la console ;
• un relais mécanique monté pivotant autour d'un axe entre une position de repos et une position de verrouillage, ledit relais étant constitué de deux bras, l'extrémité libre du premier bras étant solidaire de l'élément du mécanisme de commande, de sorte que le relais mécanique est pivoté en position de verrouillage lorsque la console passe en position escamotée, l'extrémité libre de l'autre bras portant un organe de blocage apte à venir s'enclencher dans un logement prévu à cet effet sur le levier de commande en translation, lorsque le relais est pivoté en position de verrouillage.

In practice, the locking means of the translation control levers are constituted by:

• a mechanism for controlling the locking means, actuated by the pivoting of the console, and comprising, near the control levers in translation, an element whose position is a function of the position of the console;
• a mechanical relay pivotally mounted about an axis between a rest position and a locking position, said relay being constituted by two arms, the free end of the first arm being integral with the element of the control mechanism, so that the mechanical relay is pivoted in the locking position when the console goes into the retracted position, the free end of the other arm carrying a locking member adapted to engage in a housing provided for this purpose on the control lever in translation, when the relay is pivoted to the locking position.

In other words, the pivoting of the console causes the introduction of the locking member in a portion of the control lever in translation so that it is then impossible to maneuver following this lock.

To allow a locking of the control lever in translation when it is slightly operated, the control mechanism of the locking means comprises a tension spring providing a return force of the mechanical relay in the locking position when the console is in the retracted position .

In this way, as soon as the console is raised, the tension spring acts on the relay to force it to engage in the control lever in translation as soon as the locking member comes opposite the housing.

In addition, the portion of the end of the lever capable of coming into contact with the mechanical relay is designed so that the locking member penetrates inside the housing regardless of the position of the control lever. This prevents the control lever from being locked in the engaged position due to the action of the mechanical relay.

• soit par un câble relié à la console,
• soit par un circuit électrique alimentant un électroaimant, la position de l'équipage mobile de l'électroaimant étant fonction de la position de la console ;
• soit par un vérin hydraulique associé à un ressort de rappel, la chambre dudit vérin hydraulique étant alimentée par le circuit hydraulique de commande de l'équipement de travail, et la position du piston du vérin étant fonction de la position de la console.

In practice, the control mechanism of the locking means may consist of:

• either by a cable connected to the console,
• either by an electric circuit supplying an electromagnet, the position of the mobile unit of the electromagnet being a function of the position of the console;
• or by a hydraulic cylinder associated with a return spring, the chamber of said hydraulic cylinder being fed by the hydraulic control circuit of the work equipment, and the position of the cylinder piston being a function of the position of the console.

In a particular embodiment, the housing formed on the lever in translation has a flared opening, so as to guide the engagement of the locking member.

In this way, the finger is allowed to enter the locking housing, regardless of the position of the manipulator in the vicinity of the rest position.

Indeed, given the manufacturing tolerances as well as the different offsets observed in the distributors, the translational control manipulator may have a neutral position that varies slightly. In this way, the flared shape compensates for these small offsets.

In an alternative embodiment, the mechanical relay further comprises a torsion spring, ensuring a return force of the mechanical relay in the rest position. In this way, in the case where the control mechanism of the locking means would fail, for example if it is a cable if it is cut, the relay is automatically placed in the rest position, not to permanently block the operation of the control lever in translation.

In practice, the receiving housing of the locking member is formed by at least one fork open towards said member.

Description of figures

• la figure 1 est une vue schématique de côté de l'ensemble formé par la console supportant le manipulateur de commande de l'équipement de travail, ainsi que du levier de commande en translation, relié par le mécanisme de commande des moyens de blocage, le tout montré en position de travail.
• la figure 2 montre les éléments de la figure 1 en position de blocage ;
• la figure 3 est une vue de côté du relais mécanique ;
• la figure 4 est une vue de côté de détail d'une partie du relais mécanique de la figure 3, montrant les deux bras ;
• la figure 5 est une vue de dessus du relais mécanique de la figure 3 ;
• la figure 6 est une vue de coté identique à la figure 1, dans laquelle le mécanisme de commande des moyens de blocage sont réalisés par un vérin hydraulique associé à un ressort de rappel.

The manner of carrying out the invention, as well as the advantages which result therefrom, will emerge from the description of the embodiments which follow, in support of the appended figures in which:

• FIG. 1 is a schematic side view of the assembly formed by the console supporting the control manipulator of the work equipment, as well as of the control lever in translation, connected by the control mechanism of the locking means, the all shown in working position.
• Figure 2 shows the elements of Figure 1 in the locking position;
• Figure 3 is a side view of the mechanical relay;
• Figure 4 is a detail side view of a portion of the mechanical relay of Figure 3 showing the two arms;
• Figure 5 is a top view of the mechanical relay of Figure 3;
• Figure 6 is a side view identical to Figure 1, wherein the control mechanism of the locking means are formed by a hydraulic cylinder associated with a return spring.

Way of realizing the invention

As already stated, the invention relates to a control device of a driving station of public works machinery for ensuring the locking of the controls in translation simultaneously with the blocking of the controls of the hydraulic circuit of the work equipment.

Thus, as seen in Figure 1, the control of the hydraulic circuit is provided by a manipulator (2), mounted on a console (3) forming an armrest, and generally placed to the right or left of the driver, between the latter and the area of access to the driving position. The console (3) has an ergonomic shape, the armrest allowing the driver to have the forearm rested when operating the manipulator (2). This manipulator (2) is connected in known manner to the hydraulic control circuit of the work equipment and turret not shown, and known as such, so that it is not necessary to describe it here more in detail.

In known manner, the console (3) supporting the manipulator (2) is pivotally mounted relative to an axis (4). In known manner, the pivoting of the console (3) causes by a known device not shown, the power cut of the hydraulic control circuit of the work equipment and the turret. In this way, when the driver lifts the armrest (3), the manipulator (2) becomes inoperative and can not cause by a shock or an unexpected maneuver, the movement of the turret or the work equipment.

Furthermore, the public works machine can be caused to move on the ground by the action of the control lever in translation, illustrated in Figure 1 by a manual manipulator (10), but which can, without leaving the frame of the invention, be replaced or supplemented by a pedal located at the floor of the driving position.

This lever (10) is mounted on a support case (11). It is articulated with respect to an axis (12) and extends below this axis by a lower portion (13). On this lower portion (13), is connected to a linkage (14) or a cable connected to the engine, or more generally to the mechanism causing the advance or the translation of the vehicle.

According to a preferred embodiment of the invention, the lower end (13) of the lever (10) for translational control has a flared fork (16) open on the bottom.

In addition, the housing (11) for supporting the lever (10) for translational control has, in accordance with the invention, a mechanical relay (20) mounted hinged by an axis (21) parallel to the axis (12) of pivoting of the lever. This mechanical relay (20) comprises two arms (22,23) as seen in detail in Figure 3. These two arms (22,23) are substantially in a right angle configuration. The arm (22) has in its upper part (25) a notch (26) for hooking and securing to the control means of the locking device described below. The other arm (23) has a notch (28) semi-cylindrical for receiving the locking member itself constituted by a rod (30) for entering the fork (16).

According to a preferred embodiment of the invention, the mechanical relay (20) is coupled to the console (3) by the control means illustrated in FIGS. 1 and 2. In the form shown, this control mechanism is constituted by a cable ( 40) connected by one of its ends (41) to the bracket, while its opposite end (42) is connected, via a tension spring (45) to the notch (26) of the arm (22). ) of the mechanical relay (20). The path of the cable (40) follows the arrangement of the driving position.

More specifically, the end of the cable (41) connected to the console is secured to a cam (50) mounted near the axis of rotation (4) of the console (3) relative to the rest of the driving position . This cam (50) has a cylindrical outer surface and advantageously has a groove in which is housed the cable when the cam pivots.

Figures 1 and 2 illustrate the device according to the invention in its two extreme positions, respectively working and locking.

Thus, as seen in Figure 1, when the console (3) is in the working position, that is to say horizontal, the cable (40) is released, that is to say pushed back in its sheath. The mechanical relay (20) which is pivotally mounted relative to the axis (21), is pushed back into the position shown in Figure 1 by a torsion spring located at the axis (21) and not shown.

It follows that the locking member (30) is offset at the bottom and out of reach of the housing that forms the fork (16) of the lower end of the lever. Conversely, as illustrated in Figure 2, when the bracket (3) is retracted or raised, the cam (50) is pivoted and exerts traction on the cable (40) of the control mechanism. This cable (40) is thus pulled inside its sheath, and its end (42) thus pulls on the arm (22) of the mechanical relay (20).

It follows that this relay (20) pivots with respect to the axis (21) and that consequently the locking pin (30) penetrates inside the fork (16) forming the low end of the lever .

In this way, the lever (10) is locked in the neutral position and any maneuver that would cause the movement of the machine is impossible.

According to a preferred embodiment of the invention, the shape of the fork (16) is slightly flared to allow engagement of the locking finger (30) of the relay (20) even if the lever (10) for translational control is slightly offset from the theoretical neutral position. Indeed, it is known that due to the manufacturing tolerances, and especially the inherent play in the use of hydraulic distributors, the neutral position can cover a certain angular range. The use of this flared shape thus makes it possible to overcome these different tolerances and offsets.

According to a preferred feature of the invention, the end of the cable (42) located near the translational control lever, is equipped with a tension spring (45). Indeed, in the case where the lever (10) of translation control is removed from its neutral position, the pivoting of the mechanical relay (20) is blocked by the ends of the fork (16). The retraction of the console (3) is still possible, thanks to the extension capacity of the characteristic spring (45). Thus, when subsequently, the translational control lever (10) returns to a neutral position, the force exerted by the characteristic spring (45) allows the mechanical relay (20) to pivot and the locking pin to enter ( 30) in the fork (16), and therefore the locking in the neutral position of the control lever (10).

In addition the lower end of the lever (10) is designed so that the locking finger (30) can not escape the fork (16) when the spring (45) exerts its action. In this way, it is impossible for the lever (10) to be kept locked in the engaged position under the effect of the mechanical relay (20).

Obviously, the invention is not limited to the embodiment illustrated in Figure 1 in which the retraction of the console is transmitted mechanically to the mechanical relay, but obviously it covers the various variants in which the control mechanism blocking means is electrically, for example with an electromagnet associated with the mechanical relay and whose power depends on the position of the console. In this case, in the event of failure of the control system of the electromagnet, a return spring ensures the return of the mechanical relay in the unlocked position to avoid the inadvertent blocking of the control lever (10).

Another variant is illustrated in FIG. 6 in which the mechanical relay (20) is actuated by a hydraulic cylinder (60) equipped with a return spring (61).

More specifically, the hydraulic cylinder is powered by a hydraulic circuit (62) which is cut, like the main circuit, during pivoting of the console (3). In this way, when the supply of the cylinder (60) ceases, the pressure in the chamber (64) of the latter drops and under the effect of the action of the spring (61) in compression, the piston (65) exerts the force on the arm (23) of the mechanical relay (20) to cause the pivoting of the latter and the engagement of the locking finger (30) in the fork (16) of the lever (10).

Of course, this hydraulic variant of the control mechanism of the locking means may also be equipped with a spring equivalent to the referenced spring (45) in FIGS. 1 and 2.

• le blocage simultané du circuit de commande de l'équipement de travail et du circuit de commande en translation ;
• la commande simultanée de la coupure du circuit hydraulique de commande de l'équipement de travail et de l'entraînement en translation de l'engin ;
• le blocage automatique sans manoeuvre particulière, dès que le conducteur relève la console supportant le manipulateur ;
• l'insensibilité aux différentes tolérances de fabrication des pièces mécaniques et aux différents décalages inhérent à l'utilisation de distributeurs hydrauliques ;
• un retour en position de blocage du manipulateur de commande en translation même si ce dernier est hors de la position neutre lorsque la console portant un manipulateur de commande de circuit hydraulique est relevée;
• l'impossibilité d'un blocage du levier de commande en translation dans une position enclenchée lorsque la console est relevée;
• l'impossibilité d'un blocage intempestif, et donc d'immobilisation de la machine en cas de déficience du mécanisme de commande des moyens de blocage, par exemple une rupture de câble, ou un manque de source d'énergie.

It follows from the foregoing that the control device according to the invention has the following advantages:

• simultaneous blocking of the control circuit of the work equipment and the control circuit in translation;
• simultaneous control of the cut-off of the hydraulic control circuit of the work equipment and the translational drive of the machine;
• automatic blocking without particular maneuver, as soon as the driver raises the console supporting the manipulator;
• the insensitivity to the different manufacturing tolerances of the mechanical parts and the different offsets inherent to the use of hydraulic distributors;
• a return to the locked position of the translational control manipulator even if the latter is out of the neutral position when the console carrying a hydraulic circuit control manipulator is raised;
• the impossibility of locking the control lever in translation in an engaged position when the console is raised;
• the impossibility of inadvertent blocking, and thus immobilization of the machine in case of deficiency of the control mechanism of the locking means, for example a cable break, or a lack of energy source.

Claims (9)

1. A control device for an earth-moving machine comprising a carrier and a working implement having:

   - a circuit to control translational movement of the carrier actuated by the movement of levers (10) articulated around a neutral position;

   - a hydraulic control circuit for the working implement actuated by at least one handle (2) mounted on a console (3) capable of swivelling between a working position and a retracted position, the hydraulic circuit being equipped with a device capable of switching it off when swivelling console (3) moves to its retracted position,

   characterised in that it also comprises means of locking movement of articulated levers (10) of the translational movement control circuit, said means being actuated when swivelling console (3) moves to its retracted position, even if the control levers are in a position other than their neutral position, said means being capable of ensuring locking of movement of the levers as soon as the latter move to their neutral position.
2. A control device as claimed in claim 1, characterised in that the means of locking the articulated levers in position consist up of:

   - a mechanism (40) to control the means of locking, actuated by swivelling of console (3) and comprising, in the vicinity of translational movement control levers (10), a component (42), the position of which depends on the position of the console;

   - a mechanical relay (20) rotatably mounted around a shaft (21) between an idle position and a locking position, said relay (20) consisting of two arms (22, 23), the free end (25) of first arm (22) being joined to component (42) of the control mechanism so that mechanical relay (20) is swivelled into the locking position when console (3) moves to its retracted position, the free end of the other arm (23) supporting a locking device (30) capable of engaging in a recess (16) provided for this purpose on translational movement control lever (10) when relay (20) is swivelled into the locking position.
3. A control device as claimed in claim 2, characterised in that the control mechanism of the means of locking comprises an extension spring (45) exerting a restoring force on mechanical relay (20) in the locking position when console (3) is in its retracted position.
4. A control device as claimed in claim 2, characterised in that the mechanism for controlling the means of locking consists of a cable (40) connected to the console.
5. A control device as claimed in claim 2, characterised in that recess (16) on the translational movement lever has a flared opening so as to guide engagement of locking device (30).
6. A control device as claimed in claim 2, characterised in that mechanical relay (20) also comprises a torsion spring exerting a restoring force on the relay in its idle position.
7. A control device as claimed in claim 2, characterised in that the recess is formed by at least one fork (16) which opens in the direction of the locking device.
8. A control device as claimed in claim 2, characterised in that the means of locking consist of an electrical circuit that powers an electromagnet, the position of the moving element of the electromagnet varying as a function of the position of the console.
9. A control device as claimed in claim 2, characterised in that the means of controlling the means of locking consist of a hydraulic cylinder (60) associated with a return spring (61), the chamber (64) of said hydraulic cylinder being fed by the hydraulic circuit (62) for controlling the working implement and the position of the piston (65) of the cylinder varying as a function of the position of console (3).

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