Method for controlling a set of hydraulic motors for driving a drill head - Patents.com

Abstract

Each motor (8) includes a cylinder block (13) separate from the cylinder blocks of the other motors, in a method in which the head (2) is driven at a set point speed by only a first subset (M1, M4, M7) of the motors in the set, and subsequently the head is driven at the set point speed by only a second subset (M2, M5, M8) of the motors in the set, the second subset being different from the first subset.

Description

[Technical field]

[0001] This invention relates to excavators and methods for controlling same, and in particular to a control strategy for engaging and disengaging the hydrostatic drive motor of the excavation head of such machines.

[0002] The invention applies in particular to tunnel boring machines which excavate horizontally or nearly horizontally, and to vertical boring machines. The term "drilling" is understood to mean the act of digging into the earth, regardless of the direction and aiming of the act. In the remainder of the text, the terms "cutting head" and "drilling head" are used interchangeably. [Background technology]

[0003] The nature and density of the soils that are successively excavated by the tunnel boring machine are often very different, and therefore the drilling head needs to resist load variations during its rotation and the forward movement of the tunnel boring machine.

[0004] A tunnel boring machine includes, for example, a hydraulic motor used to drive a head rotating around an axis that is the longitudinal axis of the tunnel boring machine. In relation to a tunnel boring machine, following the duty cycle approved by the tunnel boring machine manufacturer, is the architecture of a hydrostatic transmission system, which includes a certain number of hydrostatic power units forming hydraulic pumps that power parallel motors.

[0005] Following the desired control mode and the occurring duty cycle, the hydraulic motors are always engaged or disengaged in the same way. Let us suppose that there are nine motors. To obtain a constant high speed, it may be arranged to operate only three of the motors to rotate the head (designated as M1, M4 and M7 according to their sequential number in the circle formed by the motors), and these are always the same motors. Similarly, to obtain a slower speed, six of the motors are engaged, and these are also the same motors (i.e., motors M2, M5 and M8 in addition to the aforementioned motors). Finally, to obtain an even slower speed, all motors are engaged (from M1 to M9). This architecture has the advantage of being simple to create and control. However, given these preset operating cycles, the life of the motors is highly variable. Thus, by way of comparison and example: - 5,600 hours for motors M1, M4 and M7 - 9,800 hours for the less used motors M2, M5 and M8 - 25,000 hours for the less used motors M3, M6 and M9 Given the harsh conditions in which excavation takes place, the drive system of the drilling head needs to be designed to maximize the life of the system and associated components. However, the above example shows that there is greater variation in the life of the head's motors. Subsequently, the tunnel boring machine goes into downtime as soon as one of the motors becomes inoperable, which occurs more frequently when the tunnel boring machine reaches or exceeds its lifespan, even though many of the other motors may be in use. This downtime creates costs and delays that are detrimental to the project for which excavation is required. Summary of the Invention [Problem to be solved by the invention]

[0006] Accordingly, one object of the present invention is to increase the duration and life of an excavator. [Means for solving the problem]

[0007] To this end, there is provided a method for controlling an assembly of hydraulic drive motors of a drilling head, each motor including a cylinder block separate from the cylinder blocks of the other motors, the method comprising: - the head is driven solely by the first subassembly of the motor of the assembly at a set point speed, and then - the head is driven solely by the second subassembly of the motor of the assembly at a set point speed; The second subassembly is different from the first subassembly. A method is provided.

[0008] It is therefore not always the same motor that rotates the head at a given speed. It is therefore a matter of engaging and disengaging the motors in sequence, so as not to always have the same motor active during the excavation or workover phase. This sequence of engagement and disengagement makes it possible to harmonize the usage time of the motors and to increase their overall lifespan. The invention produces a homogenization of the lifespan of the installed motors. It reduces the risk of motor failure and at the same time increases the overall lifespan of the assembly of all the installed motors. It makes it possible to reuse all the motors in other tunnel boring machines or in another excavation system.

[0009] Preferably, the first and second subassemblies have an equal number of motors.

[0010] Advantageously, the head is driven solely at the same speed by a third subassembly of the motor of the assembly, the third subassembly being different from the first and second subassemblies.

[0011] Thus, usage can even be shared between different motors if the number of motors permits.

[0012] In an embodiment, the speed is a first speed, the first subassembly is a first subassembly at the first speed, and the second subassembly is a second subassembly at the first speed; - the head is driven solely by the first subassembly of the motor of the assembly at the second speed, and then - the head is driven solely at a second speed by a second subassembly of the motor of the assembly; The second speed second subassembly is different from the second speed first subassembly and the first speed subassembly.

[0013] Thus, alternating use of different motors may be implemented for different rotational speeds of the head, which also makes it possible to vary the effective overall cylinder capacity of the drive system.

[0014] The second speed first and second subassemblies may be arranged to have a different number of motors than the first speed first and second subassemblies.

[0015] In an embodiment, the head is driven at the second speed solely by a second speed third subassembly of the motor of the assembly, the second speed third subassembly being different from the second speed first and second subassemblies.

[0016] Preferably, the first and second subassemblies, or the first and second subassemblies of the second speed, are discontinuous.

[0017] Also preferably, in each of the first and second subassemblies or the second speed first and second subassemblies, the motors form a figure having rotational symmetry.

[0018] Similarly, motors that do not form part of one of the first and second subassemblies or the second speed first and second subassemblies may be arranged to form figures having rotational symmetry.

[0019] In each of these cases, the motor may be a regular polygon, or more generally a figure with rotational symmetry of degree two or more, for example degree three or more. n-th order rotational symmetry is when the figure is invariant with a repeating angle of 360° / n, where n is a natural number. These arrangements ensure balancing of the loads on the motors and heads used, avoiding exposing the motors to unbalanced forces that may reduce their lifespan.

[0020] Also preferably, a method may be provided to ensure that any imbalance in the assembly more generally is in line with the load limits of the head.

[0021] The present invention relates to - each of the first and second subassemblies or the second speed first and second subassemblies includes three motors; at least one of the motors belongs to at least two of the first, second and third subassemblies or the first and second subassemblies of the second speed; - each of the first and second subassemblies or the second speed first and second subassemblies includes six motors; It may have at least one of the following characteristics. - The drop in torque supplied to the head is determined and then The steps of the method of the present invention are performed in such a way as to reduce the number of motors that drive the heads. It may be prepared as follows.

[0022] Preferably, The drop in torque supplied to the heads while they are driven by all the motors is determined, and then the steps of the method of the invention are carried out directly on a figure having rotational symmetry in combination with one of the aforementioned features.

[0023] It then deals directly with a balanced configuration that shares stresses through the motor to protect its life. - determining a drop in torque supplied to the head while the head is driven solely by one of the motors of the second speed subassembly; and then - the steps of the method of the invention are carried out directly by a subassembly of the first speed in a figure having rotational symmetry, in combination with one of the above-mentioned features; It may be prepared as follows.

[0024] Again, we are directly dealing with a balanced configuration that shares stresses through the motor to protect its life.

[0025] In an embodiment, - if a drop in the torque supplied is detected in the presence of a constant difference in hydraulic pressure available to the motor, then an increase in the speed of the motor driving the head is controlled, or If a drop in the torque supplied is detected and if the set point speed remains constant, a reduction in the flow rate of fluid supplied to the motor driving the head is controlled.

[0026] At a constant torque, it is also possible to envisage trying to increase the rotational speed of the drilling head and thus reducing the number of effective motors. - the increase in torque supplied to the head is determined and then The steps of the method of the present invention are carried out to increase the number of motors driving the heads. It may be prepared as follows.

[0027] Preferably, While the heads are driven by all the motors, the increase in torque supplied to the heads is determined, and then The steps of the method of the invention are performed directly on a figure having rotational symmetry, in combination with one of the aforementioned features. - determining an increase in torque supplied to the head while the head is driven solely by one of the motors of the second speed subassembly; and then - the steps of the method of the invention are carried out directly by a subassembly of the first speed in a figure having rotational symmetry, in combination with one of the above-mentioned features; It may be prepared as follows.

[0028] In an embodiment, If an increase in the torque supplied is detected, a reduction in the speed of the motor driving the head is controlled, either keeping the power constant or reducing the power supplied, or If an increase in the torque supplied is detected and if the set point speed remains constant, an increase in the flow rate of fluid supplied to the motor driving the head is controlled.

[0029] At a constant torque, it is also possible to envisage trying to reduce the rotational speed of the drilling head and thus increasing the number of effective motors.

[0030] Advantageously, the data of the estimation of the overhaul interval of one of the motors are taken into account, in particular starting from a predetermined event such as the start of the motor, the following items: - the force received by the motor, - hydraulic pressure applied to the motor, - at least one temperature of the motor's environment, - the temperature of at least one of the motors, - Vibrations applied to the motor, - duration of motor use, - motor speed, - the power provided by the motor, - the energy consumed by the motor, - loss of power in the motor, - Pressure / Velocity histogram to calculate weighted average, - heat traces, - vibration traces, - Oil deterioration due to aging, - the power experienced by the motor from this event, and - integral of lost power The determination is based on at least one of the following:

[0031] The temperature of the motor may be obtained, for example, by a physical temperature sensor. It may also be obtained by using a loss model and a thermal model of the motor, which is used to calculate the internal temperature of the motor, as the data then comes from a virtual temperature sensor. The motor temperature may be obtained from both physical and virtual sensors.

[0032] This consideration of overhaul intervals also preserves the life of the motor since the objective is to stress the motor with the longest overhaul interval possible.

[0033] Preferably, at least one of the subassemblies is formed by selecting a respective motor of the subassembly as a function of data on an estimate of the overhaul interval of the motor.

[0034] Advantageously, data of an estimate of the overhaul interval of one of the subassemblies is determined by data of at least one estimate of the overhaul interval of at least one of the motors of the subassemblies.

[0035] For example, the data for the estimated overhaul interval for one of the subassemblies is: - Data for less estimation of overhaul intervals for motor subassemblies, - the average of the data for the estimated overhaul intervals of the motors of the subassemblies, as well as - a calculated value based on at least one of the data of the estimated overhaul interval of the motor of the subassembly and based on at least one other data; is determined to be equal to one of

[0036] Provision may be made for one of the subassemblies or motors used to drive the head to be selected as a function of data on the estimated overhaul interval of the subassembly or motor.

[0037] In an embodiment, the control means uses a table of data for estimating overhaul intervals for the motors and / or subassemblies.

[0038] The control means may be arranged to update the table after shutdown of the machine holding the head and / or after a given time.

[0039] The present invention also provides: - a drilling head; - an assembly of hydraulic motors configured to rotatably drive a drilling head, each motor including a cylinder block separate from the cylinder blocks of the other motors; - means capable of controlling the implementation of the method according to the invention; An excavator may be provided, including:

[0040] Advantageously, the machine includes a valve configured for at least one of the motors to control engagement of the motor to drive the head, and disengagement of the motor to not drive the head, independently of the other motor.

[0041] At least one of the motors may be arranged to have a fixed cylinder capacity, a given number of sub-cylinder capacities, or a continuously variable cylinder capacity.

[0042] At least two of the motors may be provided with completely different cylinder capacities.

[0043] In an embodiment, each motor includes a radial piston and a multi-lobe cam.

[0044] All hydraulic motors mesh, via a pinion, with a toothed internal ring gear which is used to rotate the drilling head.

[0045] In an embodiment, at least one of the hydraulic motors directly drives the pinion, i.e., the pinion rotates at the speed of the hydraulic motor cylinder block.

[0046] Alternatively, at least one reduction gear may be provided disposed between the pinion and its associated motor, i.e. the pinion rotates slower than the cylinder block of the hydraulic motor.

[0047] Preferably, the machine includes a closed loop circuit for supplying pressurized fluid to each of the motors.

[0048] Advantageously, the machine includes at least one sensor for measuring a parameter.

[0049] The machine may form a tunnel boring machine or a vertical boring machine.

[0050] Finally, according to the invention, a program may be provided, comprising code instructions suitable for controlling the implementation of the steps of the method according to the invention when executed in an automated means.

[0051] Two embodiments of the invention will now be described, by way of non-limiting examples, with reference to the drawings. [Brief description of the drawings]

[0052] [Figure 1] FIG. 1 is a perspective view of a portion of a tunnel boring machine in accordance with an embodiment of the present invention. [Diagram 2] FIG. 2 is a cross-sectional view of one of the motors of the tunnel boring machine. [Diagram 3] FIG. 2 is a vertical cross-sectional view of the tunnel boring machine of FIG. 1 showing the arrangement of the motors driving the head. [Figure 4-6] FIG. 4 is a view similar to FIG. 3 showing three configurations of engine engagement. [Figure 7] 2 is a flow chart illustrating a portion of the method of the present invention. [Figure 8] FIG. 1 shows the arrangements for controlling a tunnel boring machine. [Figure 9] FIG. 1 shows the arrangements for controlling a tunnel boring machine. [Figure 10] FIG. 1 shows the arrangements for controlling a tunnel boring machine. [Figure 11] FIG. 1 is a diagram of the hydraulic circuit architecture of a tunnel boring machine. [Figure 12] FIG. 1 is a diagram of the hydraulic circuit architecture of a tunnel boring machine. [Figure 13] FIG. 1 is a diagram of the hydraulic circuit architecture of a tunnel boring machine. [Figure 14] FIG. 1 is a diagram of the hydraulic circuit architecture of a tunnel boring machine. [Figure 15] FIG. 1 is a diagram of the hydraulic circuit architecture of a tunnel boring machine. [Figure 16] FIG. 11 is a perspective view of a cutting head of a vertical drilling machine according to a second embodiment of the present invention. [Figure 17] FIG. 11 is a cross-sectional view of a cutting head of a vertical drilling machine according to a second embodiment of the present invention. [Figure 18] 13A to 13C are diagrams showing examples of motor arrangements in modified embodiments of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0053] I-First embodiment 1 to 15, a first embodiment of a machine according to the invention forming a tunnel boring machine 100 will now be described. This is therefore a boring machine having a horizontal drilling axis XX. A-Machine The machine 100 has an overall shape with rotational symmetry about an axis XX. The machine 100 comprises a drilling or cutting head 2 mounted for rotational movement about the axis XX with respect to a cylindrical body 4 of the machine. The head has a generally disc shape and is equipped at its front outer end with cutting members 6 enabling the head to bite into the material, rock or subsoil it bears during excavation.

[0054] The machine is equipped with an assembly of hydraulic motors arranged to drive the drilling head 2 in rotation with respect to the body 4. In this case, each motor 8 has a fixed cylinder capacity. That is the case, for example, of motors such as those described in document FR-3,094,425 in the name of the Applicant.

[0055] Thus, in this example, as shown in FIG. 2, each of the motors 8 includes a radial piston 9 and a multi-lobe cam 11. More precisely, each motor includes: - a cylinder block 13, each of whose cylinders contains a chamber in which a piston 9 slides; - a cam 11 on which each of the pistons 9 can exert a pressure to produce a torque, the cam including at least two lobes, each lobe including an upwardly sloping surface and a downwardly sloping surface, the cylinder block 13 being mounted for relative rotation with respect to the cam 11; - at least two main ducts through which the motor can deliver and receive fluid; - a fluid distributor (not shown) for distributing the fluid from the main ducts generally to the cylinders, comprising, for each cylinder, a distribution valve capable of connecting the chamber of the cylinder to one or the other of the main ducts in order to allow the fluid to enter or leave the chamber; - a control system including a sensor of the relative angular position of the cam with respect to the cylinder block for controlling the distributing valve; Includes.

[0056] The cylinder block 13 is unique to each motor 8, so that each motor has a cylinder block separate from that of the other motors. Distribution valves for each cylinder allow control of the fluid distribution within the cylinders at all times, cylinder by cylinder.

[0057] As shown in Figures 1 and 3, the motors 8 are arranged in a single circle about the axis XX and are all meshed with a toothed internal ring gear 10 which moves as a single part with the head 2, via the motor pinion, so that each motor can rotate the head. This is a direct hydrostatic transmission with several hydraulic motors, each with its pinion mounted to directly mesh with a toothed wheel which drives the drilling ram. Each hydraulic motor 8 directly drives its associated pinion, i.e. the pinion rotates at the speed of the cylinder block 13 of the hydraulic motor 8.

[0058] Apart from the embodiments described below, the tunnel boring machine 100 and the motor 8 are of a type known per se and will not be described in further detail.

[0059] The tunnel boring machine 100 also includes automation means 64 capable of controlling the implementation of the method according to the invention, which is described below.

[0060] In this embodiment there are nine motors. Of course this number may vary and be equal to, for example, 4, 6, 8, 12, 16, etc. For convenience the motors are numbered M1 through M9 in a clockwise direction starting with the motor located nearest the top as shown in Figures 3-6. B-Control Strategy Table 1 shows a first control strategy for the motor 8 forming a mode of implementation of the method of the invention. [Table 1] The first column of the table shows the scenario number.

[0061] The second and third columns show the inlet and outlet pressures Pe and Ps of motor M1. In particular, these columns may be used to identify when motor M1 is either enabled and generating torque via the inlet-to-outlet pressure differential, or disabled and spinning. These columns may be repeated for each of motors M2 through M9 to identify whether they are enabled or disabled, but this is not particularly useful for understanding.

[0062] V denotes the rotational speed of the ring gear. This is in revolutions per minute of the set point rotational speed of the drilling head. Four set point speeds are available: 3, 1.8, 1.4, and 0.1 revolutions per minute.

[0063] Column 6 shows the selected configuration C for the motors. These are the motors that engage the head and drive it in rotation by themselves. The others are hydraulically disengaged and do not drive the head, so no torque is produced. However, all motors remain mechanically linked to the ring gear and are what we call idle motors. Their pinions mesh with and rotate with the tunnel boring machine ring gear.

[0064] As a variant, the reactive motor may be arranged to be mechanically disengaged from the ring gear.

[0065] Another variant consists in disabling the motor by mechanically decoupling the hydraulic motor's output shaft and the pinion, for example by means of a clutch between these latter in mesh with the wheel.

[0066] Three configurations (numbered 1 to 3) are possible for a maximum speed of 3 rpm. Configuration 7C-A uses only motors M1, M4, and M7. The other two, 7C-B and 7C-C, use only motors M2, M5, and M8 and motors M3, M6, and M9, respectively. These three configurations are shown in Figures 4-6, respectively.

[0067] The duration of use T in minutes for each configuration is given in the fourth column, here 10 minutes for each one. Thus, by rotating the head at a first set point speed, configuration 7C-A is first used for 10 minutes, then configuration 7C-B is used for the same duration, and finally configuration 7C-C is used for the same duration. Of course, the duration of use may be other than 10 minutes. It is also possible that the configurations are not used for the same duration, but this uniformity is preferred as it still provides equal stress on the motor.

[0068] Therefore, in this method, - the head 2 is driven solely by the first subassembly M1, M4 and M7 of the motor 8 at a set point speed, and then - head 2 is driven solely by a second subassembly M2, M5 and M8, different from the first one, at the same speed, and then head 2 is driven solely by a third subassembly M3, M6 and M9 which is distinct from the first and second subassemblies and at the same speed;

[0069] It can be seen that the three subassemblies, three in this scenario, have the same number of motors and are discontinuous, i.e. have no common motors employed in pairs. In other words, each motor M1-M9 belongs to only one of these subassemblies. Moreover, in each of the subassemblies, the motors 8 form a regular polygon centered on the axis XX, i.e. here an equilateral triangle, facilitating the balancing of the stresses on the motors.

[0070] Also, three configurations (numbered 4 to 6) are possible for the following speeds (1.8 revolutions / min) slower than the first one. Configuration 4C-A uses only motors M1, M2, M4, M5, and M7, M8. The other two, 4C-B and 4C-C, respectively, - M2, M3, M5, M6, M8, and M9, and - M1, M3, M4, M6, M7, and M9 Use only motors with this specification.

[0071] The duration of use is now 21.33 minutes for each configuration, and the operation is similar to that of the first speed.

[0072] The first subassembly is here denoted as a first speed first subassembly (7C-A), and the second subassembly is here denoted as a first speed second subassembly (7C-B). - the head is driven at a second speed solely by the first subassembly (4C-A) M1, M2, M4, M5 and M7, M8 at a second speed, and then - the head is driven solely and at the same speed by a second subassembly (4C-B) M2, M3, M5, M6, M8 and M9 of a second speed, It can be seen that the head is driven at the same speed solely by the third subassembly (4C-C) M1, M3, M4, M6, M7 and M9 at a second speed.

[0073] The first, second and third subassemblies (4C) of the second speed are different from each other and from the first, second and third subassemblies (7C) of the first speed.

[0074] The first, second and third subassemblies (4C) of the second speed each have several motors, i.e. six, different from those of the first speed subassemblies, which have three, but the first, second and third subassemblies (4C) of the second speed are no longer discontinuous, since each motor 8 belongs to two of the second speed subassemblies.

[0075] Finally, rows 7 and 8 show that for the other two slower speeds, motors M1-M9 are all engaged simultaneously.

[0076] The cylinder volumes performed are summarized in Table 2 below. [Table 2] It can thus be seen that it is three subassemblies of motors that drive the head alternately for the first and second speeds. This makes it possible to equally stress all the motors and to avoid reducing the life of some of them compared to the others. There is therefore a graded use of the motors. In particular, it can be seen that all the motors are used for all the proposed speeds.

[0077] Under the same conditions of use as those given above, we then obtain a life of 10,500 h for each of the motors M1 to M9. Each of the motors 2 is disengaged 41% of the time and engaged 59% of the time.

[0078] A variation of this strategy consists in providing, under each row of Table 1, an additional row in which all motors are disengaged so that the head is immobilized. This situation allows the installation of the tunnel segment in the cavity drilled by the tunnel boring machine before continuing the excavation. The times associated with each of these new rows are 22 minutes for the first speed, 46.93 minutes for the second, 11 minutes and 2.20 minutes for the last two speeds. We then obtain a life of 25,000 h for each of the motors M1 to M9. Each motor is used under pressure 18% of the time, idled 13% of the time and stopped 69% of the time.

[0079] The use of the subassemblies corresponding to each speed is here distributed over equal time periods. However, provision may be made to distribute them differently, for example following the average hydraulic pressure level over a certain period. What matters then is not equal durations of use of the subassemblies, but equal average pressure levels proportional to the time periods during which pressure is applied to the motor. It may also be envisaged to use a first subassembly during a first drilling phase, then a second during a second phase, and so on, for the same set point speed. The strategy of use of the subassemblies may also take into account data on the overhaul intervals as seen below. C-Sequencing This control of motors at different speeds can be beneficial for sequencing the speeds and use of subassemblies as shown here.

[0080] FIG. 8 shows the variation of torque applied to the drilling head as a function of its speed in the presence of a constant hydraulic differential applied to the motors. The curve extending from point A to point H is the isodynamic curve. It can be seen that the motors are initially all engaged at point A to rotate the head with a high torque and a reduced speed. When the drilling head detects that it is cutting softer ground than before, the torque supplied becomes lower. This is detected by the pressure drop across the motor terminals using a circuit pressure gauge. In this scenario where the isodynamic curve is followed for the torque drop, the rotational speed of the drilling head increases. This speed increase is generated by the increase in the flow rate circulating in the motors. When point B is reached, it can be decided to disengage one of the engines to limit the number of motors engaged to the head to eight, and so on down to three motors at point H. This disengagement allows the rotational speed of the head to increase as the required torque is reduced. The balancing of forces is not considered here as the disengagement of the motors is done one by one.

[0081] It is possible to carry out the method and use subassemblies of different motors at one and the same rotation speed each time the number of motors required to rotate the head is less than the total number of motors, this is possible from 8 motors onwards.

[0082] Thus the machine may be run in an unbalanced mode with, say, 8 out of 9 (or 7 or 5) active motors, so long as there is a phased sequence of use such that the group of motors used is not always the same. Thus, using the following method, with every start-up the group used will change and the wear will be spread out.

[0083] FIG. 9 shows a more advantageous manner of embodiment of the method, this time keeping the balance. In particular, it proceeds as in the manner of the FIG. 8 embodiment, but this time, from point A, no motors are disengaged until point D is reached. At this stage, if the torque supplied falls below a given threshold, it allows itself to be limited to the second speed subassembly (six motors), thus proceeding by disengaging three of the nine motors. The head is then driven alternately by the three subassemblies of the second speed. Similarly, if the torque reduction continues once point G is reached, the motors driving the head are limited to three, and the head is then driven alternately by the three subassemblies of the first speed. Thus, when a drop in the torque supplied is detected, starting from a situation in which only one motor of the second speed subassembly is driving the head, the number of motors driving the head is reduced to one of the subassemblies of the first speed. The torque reduction can then follow a trajectory from point G to point H, if necessary.

[0084] In figure 10 another advantageous mode of embodiment is shown. At this time, a constant rotation speed of the head is preferred in the presence of a decrease in the torque supplied. The operation points at constant speed are then traced, forming a vertical locus on the diagram. The decrease in torque is due to the composition of the soil which becomes gradually softer. As before, at point A', it starts with all motors engaged to rotate the head with high torque. When the composition of the soil causes a decrease in torque, it also reduces the pressure difference and moves to point B' and then to point C'. At this stage, if the required torque drops further, three of the motors may be disengaged and the second speed subassembly may be used in turn. Also after this, the control means 64 adapts the rotation speed of the pump and / or changes its cylinder capacity, subject to the deactivation of the three motors. When point D' is reached, it is possible to disengage the other three motors, to use the first speed subassembly in turn, and to adapt the use of the pump. This mode of embodiment is also balanced.

[0085] These modes of embodiment are equally applicable in the reverse direction when the torque supplied is increased. Indeed, the geology of the land being excavated imposes higher or lower torque requirements for the tunnel boring machine to move forward. Since the operating point (torque-speed) is variable at any time, the system can vary at all points located under the constant power envelope curve and can enable or disable the motors according to the requirements.

[0086] Depending on the motor type and the circuit architecture, it is possible to disengage one of the motors 8 in different ways. It may be a "pressurized idle" type of disengagement, i.e. the piston 9 of the hydraulic motor returns into its housing in the cylinder block 13 so that it is no longer in contact with the cam 11. This is done by building up pressure or flow in the motor casing. Alternatively, the idle mode may be obtained by mechanical retraction of the piston 9 into the cylinder block 13 by a return spring. Also alternatively, the disengagement of the motor 8 is done by bypassing, i.e. the piston 9 remains in contact with the cam 11 and the supply and return pressures of the motor are set equal (usually to the delivery pressure). This mode of disengagement creates a larger power loss than the first one. D - Estimation data The method can also be improved by taking into account data on overhaul interval estimates.

[0087] For this purpose, each motor 8 is assigned data of the estimation of the overhaul interval of the motor. For example, such data are taken into account starting from a given event, such as the initial start of the motor, such as the following items: - the force received by the motor, - hydraulic pressure applied to the motor, - at least one temperature of the motor's environment, - the temperature of at least one of the motors, - Vibrations applied to the motor, - duration of motor use, - motor speed, - the power provided by the motor, - the energy consumed by the motor, - loss of power in the motor, The determination is based on at least one of the following:

[0088] The estimated data may be, for example, - The cumulative power received since the start of the game, - the actual validity period since it was started, and / or - Number of revolutions made since the start The remaining life may be calculated based on a table of the history of the

[0089] On this basis, for example, each of the subassemblies can be formed by selecting its respective motor 8 as a function of the associated estimated data.

[0090] Next, the data of the estimate of the overhaul interval for each subassembly is determined by the data of at least one estimate of the overhaul interval for at least one of the motors of the subassembly. To do this, various options exist. In particular, this subassembly data may include the following items: - data on lesser estimates of the overhaul intervals for the motor of the subassembly (in a sense it is the motor that forms the weak link of the subassembly), - the average of these data for the motor of the subassembly, and - a value calculated on the basis of at least one of these data of the motor of the subassembly and on the basis of at least one other data (e.g. the most recently obtained data); may be determined to be equal to one of

[0091] The estimated data may be established based on the intrinsic parameters of the motor or subassembly, the sensed data, and the history of the motor or subassembly. The estimated data represents the remaining usage capacity, such as, for example, the number of hours before maintenance.

[0092] Then, if necessary, one of the subassemblies used to drive the head is selected, for example as a priority, as a function of the data of the estimates of the overhaul intervals of the subassemblies. To do so, in this example, the control means 64 of the tunnel boring machine establishes a table of data of the estimates of the overhaul intervals of the motors and subassemblies. The control means 64 of the tunnel boring machine updates the table, for example in real time, after a shutdown of the tunnel boring machine or after a given period of time.

[0093] This way of proceeding makes it possible to take into account the history of the motors and subassemblies. The process implemented for this purpose is shown in Figure 7. During the implementation of the method, i.e. during operation 12 of the tunnel boring machine, the control means 64 calculates and evaluates parameters based on data measured by the various sensors and according to setpoint parameters (step 14).

[0094] The control means 64 checks (step 16) whether one of the parameters is outside a given interval, for example a recommended usage interval. One of these parameters may be data on the overhaul interval estimate of the motor or subassembly.

[0095] If not, then in step 14 a new evaluation of the parameters occurs.

[0096] If so, then in step 18 the control means determines a new configuration of the use of motors to drive the heads. This can be a matter of changing the number of motors or, for a fixed number of motors, changing the selection of the subassemblies used or the composition of one of the subassemblies so that one of the initially selected motors or one of the subassemblies has a reduced time in use before overhaul compared to the others.

[0097] Enabling or disabling of one or more motors follows, step 20, to adopt the selected configuration.

[0098] The evaluation then resumes at step 14.

[0099] More generally, different approaches are possible. Taking into account the estimated data therefore entails that priority is not necessarily given to force balancing when selecting the motor to engage. E-Architecture The hydraulic circuit of which the motor 8 is a part is very similar to circuits already known for such motors in tunnel boring machines. Figures 11 to 15 show this and will only be described in schematic form. Figures 11 and 12 show the whole circuit in simplified and detailed schemes respectively. Figures 13 and 14 show parts of the circuit.

[0100] The circuit includes electric motors 20, here seven, which operate respective pumps 22. The pumps 22 supply pressurized fluid to the hydraulic motors 8. To do so, all pumps have high-pressure ducts feeding a high-pressure hub 24 shared by all pumps. Supply ducts run from this hub towards the respective hydraulic motors 8. Similarly, return ducts leave these motors towards a low-pressure hub 26 shared by the motors, which then supplies low-pressure fluid to all pumps 22. Finally, in the same way, all the feed pumps are connected by feed lines to one and the same feed hub 28, which is itself connected to each of the hydraulic motors 8.

[0101] The area including the electric motor 20 and the main pump 22 is shown in more detail in FIG. 13. The electric motor 20 is connected by a mechanical linkage to the main pump 22 and, through this, to a feed pump 30 which supplies a feed line 32. The feed pump 30 is connected to a fluid reservoir 34 which is at atmospheric pressure. The main pump 22 is connected to the terminals of the closed loop. A pressure limiter 36 connects the outlet of the feed pump 30 to the tank 34. A feed valve 38 is interposed between a high pressure duct 40 and the outlet of the feed pump 30. Another feed valve 38 is interposed between a low pressure duct 42 and the outlet of the feed pump. Similarly, a pressure limiter 44 is interposed between the high pressure duct 40 and the outlet of the feed pump. Another pressure limiter 44 is interposed between the low pressure duct 42 and the outlet of the feed pump.

[0102] A three-way, three-position interchange valve 46 connects each of the high pressure ducts 40 and the low pressure ducts 42 in parallel to the tank 34, with a pressure limiter 48 placed between the valve and the tank. This valve is used to drain fluid from one of these ducts to the tank, if necessary. This valve is normally closed. Pressure sensors or gauges 50 are provided in the high pressure duct 40 and the return duct 42, respectively. These sensors are connected to control means 64.

[0103] The part of the circuit including one of the hydraulic motors 8 is shown in Figure 14. A high pressure duct 40 and a low pressure duct 42 are connected to the motor 8. A pressure limiter 52 is interposed between the high pressure duct 40 and the feed duct 32. Another pressure limiter 52 is interposed between the low pressure duct 42 and the feed duct 32. A feed valve 54 is interposed between the high pressure duct 40 and the feed duct 32. Another feed valve 54 is interposed between the low pressure duct 42 and the feed duct 32.

[0104] An engagement and disengagement valve 56 is interposed in the high pressure and low pressure ducts at the motor terminals (every motor 8 is associated with such a valve, but it cannot be seen in FIG. 12). It is a five-way, two-position valve. In the disengaged position of FIG. 14, the high pressure and low pressure fluid inlets of the motor 8 are isolated from the high pressure and low pressure ducts. In the engaged position, the high pressure and low pressure fluid inlets of the motor 8 communicate with these respective ducts. Thus, in the disengaged position, the motor is disabled and cannot drive the head 2 in rotation. In the engaged position, the motor is enabled and can drive it in rotation. The mechanical connection with the head is indicated by the line 58. This valve 56 is thus arranged to control the engagement of the motor 8 to drive the head, and the disengagement of the motor not to drive the head, independently of the other motors. Here, this is a closed loop circuit for supplying pressurized fluid to each motor.

[0105] Fig. 15 shows, in conceptual form, the control circuit of the tunnel boring machine. An operator or pilot 60 sends commands to the main automated control means of the tunnel boring machine 62, which for this purpose communicate with the automated control means 64 of the motors 8. These means 64 control the main pumps 22 and their electric motors 20, as well as the engagement and disengagement valves 56 of the hydraulic motors 8. The means 64 also receive data collected by the pressure sensor 50, or other sensors if necessary (sensors of the force received by the motors 8, sensors of the motor temperature, etc.). The means 64 also receive information regarding the speed of the motors 8. The means 64 comprise a program, which, when executed in these means, includes code instructions suitable for controlling the implementation of the steps of the method according to the invention. II-Second embodiment 16 and 17 now show a vertical drilling machine forming a second embodiment of the invention.

[0106] This is a drilling tool 200 including a vertical shaft 66 of axis XX which carries a cutting head (not shown). A motor 8 is mounted on a fixture 15 which includes a ring gear 10 rigidly fixed to the rotating shaft 66. The motor drives the rotating ring gear by means of output pinions 68, here for example four. In this type of application the number of motors rotating the ring gears is generally less than in a tunnel boring machine.

[0107] The method described for the first variant is still applicable. Thus, the objective is the same to maintain a certain symmetry and balance. However, other examples of configurations may be envisaged. The control method is, for example, implemented according to Table 3 below. [Table 3] Thus, at 100% cylinder capacity, the four motors 8M1-M4 drive the drilling head 2. When 50% cylinder capacity is required, i.e. at higher speeds, the head is driven exclusively by motors M1 and M3 during a given period, and then exclusively by motors M2 and M4 during the following period. A subassembly of two motors is geometrically balanced, since the two engaged motors are diametrically opposed to each other on either side of the axis XX at each time. However, it is also possible to have a drive with three motors and to periodically switch between several subassemblies of three motors (up to four subassemblies) according to estimation data. Similarly, only one motor may be enabled and periodically switch between the motors. Configurations with one or three motors are not geometrically balanced in the ring. The other features of the invention remain unchanged.

[0108] Many modifications may be made to the invention without departing from its scope. At least two hydraulic motors 8 or all hydraulic motors may have different overall cylinder capacities. At least one of the hydraulic motors 8 or some or all of the hydraulic motors may be provided with a fixed given number of sub-cylinder capacities, the motors being formed from basic sub-cylinder capacities, for example as described in document WO2010056743. This is a motor with radial pistons and multi-lobe cams. At least one of the hydraulic motors 8 or some or all of the hydraulic motors may also be provided with a continuously variable cylinder capacity. Reduction gears may be provided between the pinion of each motor and the ring of the tunnel boring machine.

[0109] Figure 18 shows an example of an arrangement of motors 8, which in this case has third order rotational symmetry and forms a figure that is not a regular polygon. Here there are six motors grouped in pairs, the motors in each pair being spaced apart by an angle of 15°. The pairs are spaced apart by an angle of 105°. Other angle values ​​are possible. This is an example of an arrangement for a subassembly containing six motors.

[0110] The invention is not limited to excavation, but is also applicable to hydraulic motors operating excavators or crane turrets, for example quay cranes. In both cases, as in the present invention, the motor can operate a ring.

Claims

1. 1. A method for controlling an assembly of hydraulically driven motors (8) of a drilling head (2), each motor including a cylinder block (13) separate from the cylinder blocks of the other motors, comprising: The head is driven solely by the first subassembly (M1, M4, M7) of the motor of the assembly at a set point speed, and then the head is driven solely by a second subassembly (M2, M5, M8) of the motor of the assembly at the set point speed; the second subassembly is different from the first subassembly; method.

2. The method of claim 1 , wherein the first and second subassemblies have the same number of motors (2).

3. 2. The method of claim 1, wherein the head (2) is driven solely at the same speed by a third subassembly (M3, M6, M9) of the motor of the assembly, the third subassembly being different from the first and second subassemblies.

4. the speed is a first speed, the first subassembly is a first subassembly of the first speed, and the second subassembly is a second subassembly of the first speed; The head is driven at the second speed solely by a second speed first subassembly (M1, M2, M4, M5, M7, M8) of the motor of the assembly, and then the head is driven solely at the second speed by the second speed second subassembly (M2, M3, M5, M6, M8, M9) of the motor of the assembly; the second subassembly at the second speed is different from the first subassembly at the second speed and the subassembly at the first speed; The method of claim 1.

5. 5. The method of claim 4, wherein the first and second subassemblies of the second speed have a different number of motors (2) than the first and second subassemblies of the first speed.

6. The method of claim 1 , wherein the first and second subassemblies or the first and second subassemblies at the second speed are discontinuous.

7. 2. The method of claim 1, wherein in each of the first and second subassemblies or the first and second subassemblies at the second speed, the motors (8) form a regular polygon, a figure with rotational symmetry.

8. 2. The method of claim 1, wherein the motors (8) that do not form part of one of the first and second subassemblies or the first and second subassemblies of the second speed form a figure with rotational symmetry.

9. The method of claim 7 , wherein the shape is a regular polygon.

10. 2. The method of claim 1, wherein each of the first and second subassemblies or the second speed first and second subassemblies includes three motors (8).

11. 2. The method of claim 1, wherein at least one of the motors (8) belongs to at least two of the first, second and third subassemblies or the first and second subassemblies of the second speed.

12. The drop in torque supplied to the head (2) is determined, and then The steps of claim 1 are carried out in such a way as to reduce the number of motors (8) driving the heads. The method of claim 1.

13. a drop in torque supplied to the head (2) while the head (2) is driven solely by the motor (8) of one of the subassemblies at the second speed is determined, and then The steps of claim 1, in combination with claim 7 or 8, are performed directly by the subassembly of the first speed. The method of claim 1.

14. The data of the estimation of the overhaul interval of one of said motors (8) are taken into account, in particular starting from a predetermined event such as the start of said motor, including: the force received by the motor; hydraulic pressure applied to the motor; at least one temperature of the motor's environment; at least one temperature of the motor; vibrations applied to the motor; the duration of use of the motor; the rotation speed of the motor; power supplied by said motor; the energy consumed by the motor; Power loss of the motor The method of claim 1 , wherein the distance is determined based on at least one of:

15. 2. The method of claim 1, wherein at least one of the subassemblies is formed by selecting each motor (8) of the subassembly as a function of data on the estimated overhaul interval of the motor.

16. 2. The method of claim 1, wherein the data of the estimate of the overhaul interval of one of the subassemblies is determined by data of at least one estimate of the overhaul interval of at least one of the motors (8) of the subassembly.

17. The data for estimating the overhaul interval of one of the subassemblies includes the following items: data for less estimation of the overhaul interval of the motor of said subassembly; an average of the data for estimating the overhaul interval of the motor of the subassembly; and a value calculated based on at least one of the data of an estimate of the overhaul interval of the motor of the subassembly and based on at least one other data; The method of claim 1 , wherein the value of the sine wave is determined to be equal to one of:

18. 2. The method of claim 1, wherein one of the subassemblies or the motors used to drive the head (2) is selected as a function of data on an estimate of the overhaul interval of the subassembly or the motor.

19. 2. The method of claim 1, wherein the control means (64) uses a table of data for estimating the overhaul intervals of the motor and / or the subassembly.

20. 20. The method of claim 19, wherein the control means (64) updates the table after a shutdown of a machine (100, 200) holding the head and / or after a given time.

21. a drilling head (2); an assembly of hydraulic motors (8) configured to rotate and drive the drilling head, each motor including a cylinder block separate from the cylinder blocks of the other motors; means (64) capable of controlling the implementation of the method according to claim 1; An excavator (100, 200) comprising:

22. 22. The machine of claim 21, including a valve (56) for at least one of the motors configured to control the engagement and disengagement of the motor (8) to drive the head (2) independently of the other motors.

23. 22. Machine according to claim 21, wherein at least one of the motors (8) has a fixed cylinder capacity.

24. 22. The machine of claim 21, wherein at least one of the motors has a given number of sub-cylinder capacities or a continuously variable cylinder capacity.

25. 22. A machine as claimed in claim 21, wherein each motor (8) includes a radial piston and a multi-lobe cam.

26. 22. A machine as claimed in claim 21, including a closed loop circuit for supplying pressurised fluid to each motor (8).

27. 22. The machine of claim 21, including at least one sensor (50) for measuring a parameter.

28. 22. A machine according to claim 21, forming a tunnel boring machine (100).

29. 22. A machine according to claim 21, forming a vertical drilling machine (200).

30. A program comprising code instructions suitable for controlling the performance of the steps of the method of claim 1 when executed in an automated means.

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