FR2545413A1 - Automatic control device for a concrete-preparing installation - Google Patents

Abstract

The installation comprises a concrete mixer 2 and a scraping shelf 1. The concrete mixer is mounted in a tilting manner on its support via an articulation element and a mounting element which are located respectively on either side of a vertical plane passing through the centre of gravity of this concrete mixer; the mounting element 28 acts on an actuating device 31, one part 38 of which bears on the fixed support and is sensitive to the weight force which is applied to it by the concrete mixer and another part of which interacts with at least one triggering member freeing the control of the unit so that the latter stops driving the chains 7, 8 of the scraping shelf 1 when a predetermined limit of the filling proportion is reached; at least one adjusting means, making it possible to coincide the triggering with the said limit, is inserted in the actuating device.

Description

Servo control device for concrete manufacturing plant.

 The present invention relates to a concrete manufacturing installation comprising a concrete mixer and a scraping radius preferably towable. It relates more specifically to a device for controlling the control of the scraping radius at the filling rate of the concrete mixer.

The concrete used in construction is generally:
- either prepared in more or less sophisticated and automated "concrete batching" plants,
- either prepared in small quantities in concrete mixers; this solution is the most widespread in number because it is adopted by mason craftsmen and small businesses.

 Concrete is made up of cement, water and above all aggregates (sand, gravel, gravel, etc.) in well-defined proportions for each. type of concrete.

 As in "concrete batching plants" the problem of respecting the proportions of the concrete constituents and the quantity X produced has been well resolved, which makes it possible to obtain a concrete of regular quality, as much for concrete mixers who are loaded manually at the shovel the belon obtained is of poor and irregular quality. The "concrete plants" are equipped with one or more "scales" of mechanical or electronic type allowing to weigh each constituent and thus to obtain the desired proportions and quantity. They are also equipped with a complex electrical cabinet making it possible to make the complete cycle of concrete production automatic.

 The cost of electrical cabinets and scales makes the techniques used on "concrete plants" inapplicable to the automation of a simple concrete mixer.

 However, it is currently possible with the aid of equipment of the "scraping spoke" type to mechanize the loading of a concrete mixer, replacing manual loading with a shovel, at an acceptable cost.

 This application has however a first drawback according to which the presence of an operator is necessary to monitor the loading and stop it in due time. A second drawback lies in the fact that loading can only be carried out in variable quantities, since it depends on the appreciation of the operator.

 The object of the present invention is to remedy these drawbacks by subtracting the installation: concrete mixer scraping with human intervention and by automating in a simple and inexpensive way the operation of the scraping spoke without having to resort to a complex electrical cabinet and to a or more scales.

 To achieve this object, the present invention proposes to control the scrolling control of the scraping radius to the filling rate of the concrete mixer, this control taking as witness a first filling carried out manually to reproduce it faithfully then repetitively and automatically.

 In accordance with the invention, the concrete mixer is tilted on its support by means of an articulation element and a base element situated respectively on either side of a vertical plane passing through the center of gravity of this concrete mixer; the base element operates on an actuating device, a part of which rests on the fixed support is sensitive to the heavy force applied to it by the concrete mixer and another part of which transforms this force, at least when the filling rate reaches a manually preset limit, in an intervention quantity (such as a displacement, a mechanical, hydraulic, electric or other impulse), cooperates with at least one triggering member releasing the control of the group so that it ceases dtentral- the chains of the scraping spoke when the preset limit of the filling rate is reached; at least one adjustment means making it possible to make the trigger coincide with said preset limit of the filling rate is inserted in the actuating device.

 This actuating device does not weigh the load of aggregates delivered by the scraping beam, but compares the heavy force applied to it by the concrete mixer with the manner of a beam or more precisely the magnitude transformed by the control value of this determined during the first manual loading, by adjusting the adjustment means.

 Preferably, the adjustment means are multiple and sequentially ordered in order to be able to dose several components successively in the concrete mixer.

 A dosing program selector corresponding to several types of concrete is incorporated into the actuation device, to coordinate its initial intervention with that of the adjustment means or means.

According to a particularly advantageous embodiment, the concrete mixer is carried by an independent trailer, the axle and at least one crutch of which constitute the above-mentioned articulation element and the lifting element respectively; the actuating device is hydraulic and comprises at least one sensing chamber with variable capacity connected by piping to a receiving cylinder in order to constitute a closed circuit of constant volume, the sensing chamber cooperating with the base element of the concrete mixer and the movable part of the jack cooperating with the aforementioned triggering member; the pre-cited adjustment means equips either the movable part of the jack or the triggering member, facing and at a distance from each other
Various other characteristics and advantages of the invention will also emerge from the detailed description which follows.

 Embodiments of the object of the invention are shown, by way of nonlimiting examples, in the accompanying drawing.

On this drawing
- Figure I is a schematic elevation illustrating a first embodiment of the installation according to the invention
- Figure 2 is a top plan view also schematically taken relative to Figure 1
- Figure 3 is a diagram of a first embodiment of the hydraulic type of the actuating device
- Figure 4 is a diagram of a second embodiment of the hydraulic type of the actuating device
- Figure 5 is an elevation similar to that of Figure lX showing a second embodiment of the installation
- Figure 6 is a diagram of a third embodiment of mechanical type of the actuating device
- Figures 7 and 8 are diagrams of a fourth embodiment of the electrical type of the actuating device and a variant
- Figure 9 is a diagram of a programfi selector: es applied to the first embodiment of the actuating device according to Figure 3
- Figures 10 and 11 are views similar to Figures 1 and 2, showing a third embodiment of the installation
- Figures 12 and 13 are diagrams of a fifth and a sixth embodiment respectively, of the electrical type, of the actuating device
- Figures 14 and 15 are diagrams in elevation-section and plan view respectivelyJconcernant a seventh embodiment of mechanical type of the actuating device
- Figure 16 is a view similar to Figure 15 relating to a sequential variant.

 The installation comprises a scraping radius 1 and a concrete mixer 2 which can be fixed and, as soon as they are intended for relatively small sites, are removable and transportable. However, in the examples shown in Figures 1 and 2, 5, 10 and 11, they are towable.

 According to the embodiment illustrated in FIGS. 1 and 2, the scraping spoke 1 comprises a cassis 3 supporting a high anterior double pulley 4, a low anterior double pulley 5 and a low posterior doubleS pulley 6; these pulleys or other guide members such as nuts, pinions, etc. are arranged along the vertices of an obtuse triangle. The pulleys 4 to 6 support two endless chains 7 and 8 between which extend buckets or scrapers 9. the pulleys 5 and 6 are idle, while the pulley 4 is driving and connected by a transmission 10 to a group of drive 11, which is placed under the control of a control box 12 to scroll the chains in the direction of the arrow F or stop them. The chassis 3 also supports a steep inclined ramp 13 against which the buckets 9 of the anterior strand of the chains which is parallel thereto, in order to raise the aggregates previously taken from the ground by the lower horizontal strand and to pour them into a chute 14 provided for feeding the concrete mixer 2. In front of the ramp 13, the chassis 3 is pivotally mounted about an axis 15 relative to a fixed frame 16 and connected to a pivoting drive group 17, for laterally sweeping the pile (s) of aggregates when the chains 7, 8 are scrolled.

 In the example shown, the frame 16 is the chassis of a trailer 18 equipped with an axle 19 provided with wheels 20, a rear stand 21 transversely elongated, foldable lateral arms 22 for stabilization and a removable drawbar not shown .

The tank of the concrete mixer 2 is mounted. rotating and driven in rotation about its axis of revolution in a cradle 23 pivotally mounted by pins 24 relative to a fixed support 25,
In the example shown, the concrete mixer 2 can be towed independently of the rest of the installation; its support 25 then comprises a front axle 26 provided with wheels 27 and a central rear foot 28, connected by legs 29 converging upward at bearings 30 provided for the journals 24. The axle 26 constitutes an articulation element and the foot 28 a peeling element, these elements 26 and 28 being arranged on either side of the vertical plane passing through the axis of the trunnions 24, that is to say substantially by the center of gravity of the concrete mixer tank loaded.

 It follows from the above that the concrete mixer 2, as and when it is loaded by the scraping spoke 1, exerts by its foot 28 on an actuating device 31 of which several embodiments are described in what follows, a heavy force which is a relatively complex function of the weight of the load of aggregates discharged by this scraping ray. It is not a question of deducting this weight from the aforementioned heavy force in a control cabinet, but of comparing it by this actuation device with a control force previously calibrated manually and of stopping by it the scraping ray 1 , as soon as the detected heavy force becomes equal to said control force.

 In the second embodiment illustrated in FIG. 5, the scraping spoke 1 and the concrete mixer 2 are mounted on the same frame or towable chassis 16. In this case, the front frames 29 of the support 25 of the concrete mixer 2 are articulated around axes 32 of lugs 33 of the chassis 1fi, axes which are parallel both to the axle 19 and to the pins 24; the rear legs 29 are integral with a movable plate 34 independent of the trailer chassis 16 and acting on the aforementioned actuating device 31.

 Also in this embodiment, the axes 32 and the plate 34 respectively constitute an articulation element and a base element arranged on either side of the vertical plane passing through the axis of the pins 24, that is to say substantially by the center of gravity of the tank of the loaded concrete mixer.

 In the third embodiment illustrated by FIGS. 10 and 11, the scraping spoke 1 and the concrete mixer 2 are mounted, as in the second, on the same frame or towable chassis 16. But in this case, one of the pins 24a of the concrete mixer tank is pivotally mounted about an axis 35 carried by a yoke 36 of this chassis 16 and extending in the anteroposterior direction which is that of the scraping radius in the middle position; the other pin 24b is supported by the chassis 16 by means of a detector bearing 37 of the aforementioned actuating device 31.

 Also in this third embodiment, the axis 35 and the detector bearing 37 respectively constitute an articulation element and a ptétement element disposed on either side of the anteroposterior median vertical plane of the concrete mixer 2, that is to say ie the vertical plane passing through the center of gravity thereof.

 Whatever the embodiment chosen, the actuating device 31 used must be sensitive to the aforementioned heavy force and compare it to a control force, so that it acts when it finds equality of these forces or transformed quantities to which it gave rise, on the control unit 12 of the group 11 to stop the running of the chains 7, 8 of the scraping radius.

 Several embodiments of this actuation device are described below with reference to Figures 3,4,6 to 9 and 12 to 16 and with reference to a particular embodiment according to Figures 1 and 2 or 5 or 10 and 11.

But it is quite obvious that these modes of execution are generally applicable to. other embodiments without modification. major,
According to the first embodiment illustrated in Figures 2 and 3, the actuating device 31 is of the hydraulic type and comprises
- A detector chamber 38 (Figure 2) interposed between the single central leg 28 of the support 25 (Figures 1 and 2) and the ground or other fixed support.

 - or else two detector chambers 38.1 and 38.2 (fig. 2 and 3) interposed between the rear legs 29; 1 and 29.2 which then move away from each other laterally, and a fixed support.

 In this actuating device 31, each of the detector chambers 38 is of variable capacity and constituted by a deflatable balloon 39 filled with hydraulic fluid and containing at least one return spring 40, the whole being integrated between two plates 41 and 42 intended for be interposed between the base 29 and the fixed support.

 In the embodiment with a single detector chamber 38, the latter is connected by a pipe 43 (FIG. 2) to a receiving cylinder 44 which, in the example shown in FIG. 3, is a similar chamber, the inflatable balloon 45 of which is provided with end plates, one of which 46 is supported on a support 47 of the chassis 3 of the scraping radius and the other 48 of which cooperates with an opposing spring 49 extending outside and also taking support on the support.

 All these members 38 to 49 constitute a closed hydraulic circuit of constant volume detecting by its chamber 38 the heavy force of the tilting concrete mixer 2 and transforming this force into a displacement of the plate 48 intended to intervene on the control box 12 of group 11 of the scraping ray.

To this end, the plate 48 is provided. a rod 50 cooperating, via a threaded pusher 51, with a trigger lever 52 pivotally mounted around a pin 53 of the support 47 and returned by a spring 54 to a rest position shown in solid lines. In this position, the trigger lever 52 retains a control lever 55 in the control position shown in solid lines. The lever 55 is fixed to a shaft 56 mounted rotating in the support 47 and connected to the drive control of the chains 7, 8 of the scraping radius by the group 11; this lever 55 is also connected to a spring 57 tending to remind it, when it is released by the lever 52, towards the rest position shown in broken lines and corresponding to the stopping of said chains.

 The threaded pusher 51 is an adjustment means making it possible to adjust the stop of the chains for a displacement of the rod 50 corresponding to the control load manually deposited in the concrete mixer and detected by the chamber 38.

In the variant with two combined detector chambers 38.1 and 38.2 (fig. 2 and 3), the piping 43 leading to the receiving cylinder 44 is divided into two branches 43.1 and 43.2 connected respectively to chambers 38.1 and 38.2 respectively. A hydrostatic balance is thus perfectly established
According to the second embodiment illustrated in FIG. 4, the actuating device 31 is always of the hydraulic type and constituted like the previous one (FIG. 3) 1 with the only difference that the receiver 44 is a cylinder of the piston and cylinder type. In this case, it is a question of transforming the heavy force in a mechanical impulse; for this purpose, a pressure limiter 58 is mounted in series on the piping 43 between the detector chamber 38 or the chambers 38.1, 38.2 and the jack 44, this limiter being bypassed by a return valve 59. Thus, when the preset limit the load of the concrete mixer is reached, the hydraulic pressure reached in the chamber (s) 38 and the piping 43 a pressure threshold such that the limiter 58 opens and establishes communication with the jack 44 allowing pressure balancing. Under the impulse of this increase in pressure, this jack causes the actuation of the trigger lever 52 and the stopping of chains 7,8 of the scraping radius 1.

The pressure relief valve 58 is adjustable and then constitutes in itself the aforementioned adjustment means by which the filling rate predetermined manually is reproducible automatically,
According to the third embodiment illustrated by FIGS. 5 and 6, the actuating device 31 is of the mechanical type; the movable plate 34 on which the base element 29 rests, hangs by means of a hanger 60 under a plate 61 coupled by a detector spring 62 to another plate 63, itself supported,. '' a hanger 64, by a bracket 65 secured to the chassis 3 of the scraping radius 1. The detector plate 61 is connected by a transmission cable 65 to a part 66 housed in a threaded coupling socket 67 screwed onto a threaded tubular end piece 68 of the trigger lever 52, the cable 65 extending through a flexible sheath 69 whose ends are in fixed abutment against the plate 63 and the support 47 of the lever 52.

 In this mechanical embodiment, the tapped coupling bush 67 constitutes the aforementioned adjustment means at which the filling rate predetermines manually is reproducible automatically.

 According to the fourth embodiment illustrated by the fie. 7. the actuating device 31 is of the electrical type and comprises a trigger microswitch 70 connected to the control box 12 of group 11. This microswitch cooperates with a cam 71 moved by a transmission 72 connected to the gear element. ement 29.

This transmission element can be the rod 50 of the hydraulic embodiments according to FIGS. 3 and 4 or else the free end of a linkage replacing the cable 65 of the mechanical embodiment according to FIG. 6 or the rod 91 of the other mechanical embodiment described in what follows with reference to FIGS. 14 to 16 or any other equivalent means.

 In any case, an adjustment means is as previously provided to intervene independently on the microswitch or the rod. In the example shown, the cam 71 is slidably mounted on the transmission 72 and immobilized, after adjusting its position, by means of a pressure screw 73.

 According to the fifth and sixth embodiments illustrated by FIGS. 12 and 13, the actuating device 31 is always electric, but the microswitch 70 is integrated in a particular mechanical detector box 74 placed directly under the pikement element 29.

 In the fifth embodiment (fig. 12), the housing 74 includes a tubular cap 75 on the skirt 76 of which is centered a spring 77 bearing on a flange plate 78. On the plate 78 resting on the ground or the like fixed reference support, the microswitch 70 is mounted. In the skirt 76 of the cap receiving the base element 29, an inclined ramp 80 for triggering the microswitch is articulated about an axis 79, this ramp being applied by a spring 81 against a substantially horizontal screw 82 mounted in said skirt. This screw constitutes the aforementioned adjustment means making it possible to faithfully automate the reproduction of the filling initially determined manually.

 In the sixth embodiment (fig. 13), two springs 83 and 84 or more are interposed between two plates 85 and 86, the first resting on a fixed support and the second receiving the base element 29. The microswitch 70 carried by the plate 85 cooperates with a cam 87 fitted to the free end of a substantially vertical screw 88 mounted in the plate 86. As before, the screw 88 constitutes the aforementioned adjustment means.

 According to the seventh embodiment illustrated by FIGS. 14 and 15, the actuating device 31 is mechanical and combines means taken from previously described embodiments. Thus, the device comprises, as in the fifth embodiment, a housing 74 on the lower plate from which the cable 65 of the fourth embodiment is hung, this cable passing over a deflection pulley 89 mounted idly in the upper skirt 76 and the sheath 69 in which the cable is guided being in fixed abutment against said skirt.

 If the housing 74 is unique, its cable 65 can cooperate with triggering means similar to those described with reference to FIG. 6.

 On the other hand, if the actuating device 31 comprises two of these boxes 74.1 and 74.2 (fig. 15) placed under posterior legs spaced 29.1 and 29.2 from the base, the cables 65.1 and 65.2 which exit therefrom, pass through sheaths 69.1 and 69.2 interposed between them and the support 47, then are connected beyond the latter by a lifting beam 90 secured to a rod 91 pulled by a spring 92. On the rod 91, a cam 93 is fixed in an adjustable manner by means of 'a screw 94 and cooperates with an extension 95 of the trigger lever 52.

 Whatever the embodiment chosen, the aforementioned adjustment means can be multiple and sequentially ordered in order to be able to dose successively several components in the concrete mixer.

As shown in fig. 8 relating to an electrical embodiment according to FIG. 7 g the actuation device comprises two control microswitches 70.1 and 70.2 fixed on the support and two cooperating trigger cams 71.1 and 71.2 locked on the rod 72 so as to be adjustable independently of one another by means of screws 73.1 and 73.2
As now shown in FIG. 16 concerning a mechanical embodiment according to FIG. 15, the actuating device comprises two trigger levers 52.1 and 52.2 fixed on the support 47 and two cooperating trigger cams 94.1 and 94.2 locked on the rod 91 of the lifter so as to be adjustable independently of one another by means of screws 94.1 and 94.2
Furthermore, always whatever the execution mode selected, a program selector 96 (fig. 9) can be implemented. This selector presents several dosing programs corresponding to several types of concrete.

 In the example shown in fig. 9 relating to the hydraulic embodiment according to FIG. 3, the receiving cylinder 44 is mounted on a movable support 47m guide in translation parallel to the rod 50, relative to a fixed support 47f on which the trigger lever is mounted. This guidance is obtained by means of screws 97 lockable in the support 47f and passing through elongated slots 98 of the support 47m; it makes it possible to determine the distance between the free end of the rod 50 and the lever 52 at rest, consequently the resulting dosage. To select several dosages, the support 47m is provided with an index 90 capable of being placed opposite any one of the arrows 91.1, 91.2, 91.3 fixed on the support 47f. In order for these dosages to be programmable, the arrows 91.1 to 91.3 are mounted to slide along a guide 92 and capable of being locked in the positions selected by screws 93.1 to 93.3.

 This selector can be implemented in most cases, as long as it can be interposed without major difficulty between the fixed supports respectively of the triggering member or members and of the end or ends of the actuating device located opposite.

 The invention is not limited to the embodiments and to the embodiments shown and described in detail, since various modifications can be made without departing from its scope.

Claims (13)

1. Servo-control device for a concrete production installation comprising a concrete mixer (2) and a scraping radius (1) preferably towable, the device making it possible to control the control of the scraping radius at the filling rate of the concrete mixer, radius which comprises a drive group (11) of the chain (s) (7,8) pulling the squeegees or buckets (9), characterized  - in that the concrete mixer (2) is tilted on its support by means of an articulation element (26) and a base element (28) located respectively on either side of a vertical plane passing through the center of gravity of this concrete mixer,  - in that the base element (28) acts on an actuating device (31), a part (38; 60 to 64 5 74) of which rests on the fixed support is sensitive to the heavy force applied to it by the concrete mixer and of which another part (44 to 51; 58; 61 to 66; 74 to 82 74, 83 to 88) transforming this force, at least when the filling rate reaches a manually preset limit, into an intervention quantity ( such as a movement, a mechanical, hydraulic, electrical or other impulse), cooperates with at least one triggering member (52; 70) releasing the control of the group so that it ceases to drive the chains (7,8) of the scraping radius (1) when the preset limit of the filling rate is reached  - And in that at least one adjustment means (51; 58; 67; 73 Z 82; 88; 94) allowing the trigger to coincide with said preset limit of the filling rate is inserted in the actuation device 2. Control device according to claim 1, characterized in that the adjustment means (73.1,73.2; 94.1, 94.2) are multiple and sequentially ordered to be able to dose successively several components in the concrete mixer. 3. Control device according to claim 1, characterized in that a selector of dosing programs (96), corresponding to several types of concrete is incorporated in the actuating device, to coordinate its initial intervention with that of the or adjustment means. 4. Control device according to claim 1, characterized in that the concrete mixer (2) is carried by an independent trailer (25) whose axle (26) and at least one crutch (28) respectively constitute the element d 'articulation and the aforementioned base element. 5. Control device according to claim 1, characterized in that the concrete mixer (2) is carried by the scraping spoke (I) by being pivotally mounted on its frame (16) around the aforementioned articulation element (19 ; 35) and resting on said chassis by means of its base element (29; 24b) and the corresponding part (34; 37) of the actuating device. 6. Servo control device according to claim 1 characterized in that the actuating device is hydraulic and comprises at least one sensing chamber (38) with variable capacity connected by a pipe (43) to a receiving cylinder (44) in order to constitute a closed circuit of constant volume, the detecting chamber cooperating with the peeling element of the concrete mixer and the movable part (50) of the jack cooperating with the aforementioned triggering member (52). 7. Control device according to claim 6, characterized in that the hydraulic circuit comprises two detector chambers (38.1, 38.2) arranged on both sides of the concrete mixer (2) -and communicating with each other (in 43.1, 43.2) as well as 'with the jack (at 43). 8. Servo control device according to claims 1 and 6 or 7, characterized in that the aforementioned adjustment means (51) equips either the movable part (50) of the jack (44) or the triggering member, opposite and at distance from each other. 9. Control device according to claims 1 and 6 or 7, characterized in that an adjustable pressure relief valve (58), shunted by a return valve (59), is mounted on the pipe (43) and interposed between the detector chamber (s) (38) and the receiving cylinder (44), the movable part (50) of the latter being in contact with the trigger (52). 10. Control device according to claim 1, characterized in that the actuating device is mechanical and comprises at least one spring (62; 77; 83, 84) connecting the fixed support (65; -16) to an element mobile which can be constituted individually by the base element (24b) or by a part (61) to which it is suspended and which is itself suspended by means of the spring from a bracket (65) of said support , this mobile element acting directly or remotely on the aforementioned triggering member. 11. Control device according to claim 10, characterized in that a transmission target (65) extending, through a flexible sheath (69) whose ends are in fixed abutment, between the aforementioned movable element (61) to which it is attached and the aforementioned triggering member (52) to which it is connected with an axial clearance adjustable by the aforementioned adjusting means 12.A servo device according to the claim, characterized in that the actuating device is electric and comprises at least one trigger microswitch (70) connected to the control box (12) of the aforementioned group (11) and actuable by at at least one cam (71; 80; 87) moved either by the element of element or a transmission connected to it, the aforementioned adjustment means intervening indifferently on the position of the mid-contact or that of or canzes- 13. Control device according to claims 3 and any one of claims 6, 7, 9, 10 to 12, characterized in that the aforementioned program selector (96) is interposed between the fixed supports (47F, 47m) respectively of the triggering member (s) and of the end (s) of the actuating device located opposite.