WO2023007318A1

WO2023007318A1 - Drilling machine with optimized tool rotation by means of energy accumulation system

Info

Publication number: WO2023007318A1
Application number: PCT/IB2022/056707
Authority: WO
Inventors: Giuseppe Cartechini
Original assignee: Hpm - Hydraulic Performance Machines Srl
Priority date: 2021-07-26
Filing date: 2022-07-20
Publication date: 2023-02-02

Abstract

Drilling machine (100) comprising: a mast (4), a kelly bar (6) provided with a drilling tool (12), a winch (7) supporting and moving the kelly bar, a hydraulic motor (17) of the winch, a rotary (10) mounted on the mast (4) and connected to the kelly bar to rotate the kelly bar, a hydraulic motor (18) of the rotary, a main motor (13), at least one pump (14) actuated by the main motor and hydraulically connected to the hydraulic motors (17, 18) of the winch and of the rotary, a translation system (1 1 ) of the rotary, and an energy accumulation system (A) connected to the winch (7) of the kelly bar and to the translation system (1 1 ) of the rotary; said energy accumulation system (A) being configured to accumulate electrical or hydraulic energy during a descending travel of the kelly bar and use said accumulated energy to actuated the translation system (1 1 ) of the rotary.

Description

DRILLING MACHINE WITH OPTIMIZED TOOL ROTATION BY MEANS OF ENERGY ACCUMULATION SYSTEM

DESCRIPTION

The present invention relates to a drilling machine with telescopic kelly bar provided with tool rotation optimization system.

Drilling machines, commonly known as “augers”, suitable for drilling holes in the ground for the insertion of piles are known. Fig. 1 illustrates a drilling machine according to the prior art, which is indicated with reference M.

The drilling machine (M) comprises a base (1) rotatably mounted on an undercarriage (2) generally provided with tracks (3). A mast (4) is connected to the base (1) by means of an articulated system (5). A kelly bar (6) comprising telescopic rods is driven by the mast (4). An inner element of the kelly bar (6) is connected to a winch (7) by means of a rope (8) that is passed through pulleys (9.) The kelly bar (6) is rotated by means of a rotary (10) mounted on the mast (4). A translation system (11) is mounted on the mast to push the rotary and consequently the kelly bar downwards. The elements of the kelly bar (6) are made in such a way to transfer a torque generated by the rotary (10) and a thrust force generated by the translation system (11) of the rotary to the smaller inner element of the kelly bar (6). The lower end of the inner element of the kelly bar (6) is attached to a drilling tool (12) capable of cutting the ground through the thrust force and the torque provided by the rotary (10) in order to drill holes (F).

Generally speaking, the translation system (11) of the rotary includes a linear actuator, such as a hydraulic cylinder; however, multiple cylinders, or a rope system with winches, or a chain system with gears, etc. may be used. Also the tool (12) may be of various types, such as propeller or bucket or core barrel, etc. The term “hydraulic drilling machine” indicates a machine whose handling and operating actuators are of hydraulic type, that is to say hydraulic cylinders or motors.

Referring to Fig. 2, the machine (M) includes a diesel motor (13) that transfers power to one or more hydraulic pumps (14) which transfer oil to one or more distributors (15, 16) capable of sending the oil where it is required. In the example of Fig. 2, a first and second pump send oil to a first distributor (15) which transfers it to a hydraulic motor (17) of the winch (7) and to a hydraulic motor (18) of the rotary (10), and a third pump sends oil to a second distributor (16) which transfers it to the translation system (11 ) of the rotary.

It has been shown that if the rotation speed of the tool (12) is reduced, the teeth of the tool tend to stick into the ground, the ground resistance is significantly increased and the hydraulic pressure is increased until a maximum pressure is exceeded, resulting in a drastic reduction of the rotation speed of the tool, and possibly in its complete blockage.

In a drilling machine with telescopic kelly bar, apart from the handling in the building site, or the opening or closing of the machine for transportation purposes or during other secondary operations, such as verticalization, track opening, lifting with auxiliary winch, the drilling step can be divided into the following steps: a) rotation of the base (1 ) until the axis of the tool (12) coincides with the axis of the hole (F) (Fig. 3A); b) descending travel of the tool (12) through the opening of the kelly bar (6), releasing the rope (8) by rotating the winch (7) (Fig. 3B); c) cutting and loading the ground by means of the tool (12) (Fig. 3C). The rotary action of the tool is performed by the rotary (10), which transmits the rotational torque through the kelly bar (6), and its advancement is assisted by the translation system (11), which transmits the thrust through the rotary and the kelly bar. d) lifting of the tool (12) performed by the winch (7) through the rope (8) (Fig. 3D); e) rotation of the base (1) to a predetermined area (Fig. 3E); f) unloading of the tool (12) (Fig. 3F).

The productivity of a machine is inversely proportional to the time necessary to perform the entire cycle and therefore it depends greatly on the time necessary to cut the ground, that is to say the time taken by step c). For such a reason, the operation related to such a step is described in further detail.

The operator drives an element of the first distributor (15) related to the rotation of the rotary (10) by means of a cabin control, usually a manipulator. The hydraulic motors of the rotary, the gears, the pinion-crown assembly, and an internal driver of the rotary begin to rotate; also the telescopic kelly bar rotates, and consequently also the tool rotates. The torque required by the tool to rotate is transmitted through the kelly bar. The torque to the kelly bar is transmitted by the rotary counteracted by the mast, by the articulated joint, and by the base that rests on the ground.

The operator also drives the element of the second distributor (16) related to the translation system (11 ) of the rotary by means of another control, and the tool is pushed downwards. The element that transmits the thrust exerted on the rotary and the tool is the telescopic kelly bar.

Two types of telescopic kelly bars are known, namely the friction type and the locking type, which is commonly called interlocking type.

The friction kelly bar is made with tubes that can translate but cannot rotate. The thrust is transmitted by friction between vertical elements that are necessary to transmit the torque. In such a case it is possible that the travel of the rotary must be higher than the travel of the tool.

By turning the interlocking kelly bar clockwise, the various telescopic tubes are locked together and do not slide over each other. In such a way, an equal translation of the rotary is required for a given translation of the tool.

The ground exerts a resistance to the rotation and to the forward movement of the tool. The hydraulic pressure required to rotate the tool by means of the rotary increases when the speed of the forward movement related to the actuation of the translation system increases (11).

If the productivity of the machine is to be optimized by means of a constant rotational speed of the rotary, the operator must be able to modulate the downward thrust by means of the translation system (11 ) in such a way that the hydraulic pressure in the rotary is high, but not higher than the control starting pressure of the pump (14).

In fact, the pump (14) supplies oil in an amount related to its displacement and to the number of revolutions of the diesel motor (13) of the machine. However, if the pressure exceeds a certain value, which is known as “control starting pressure”, the power of the diesel motor (13) would not be sufficient and the diesel motor would decrease the number of revolutions until it is possibly switched off. For such a reason, a device is provided that automatically decreases the displacement (14) of the pump when a critical pressure is reached. However, in such a case, the oil flow rate and consequently the rotational speed of the tool (12) are reduced.

With reference to Figs. 4 and 4A, by way of example, if a machine has a flywheel power of 300 kw and 500 liters per minute are delivered with a speed of 1800 rpm, the control starting pressure of the pump is 200 bar. If the rotary (10) rotates at a pressure lower than the control starting pressure, its rotational speed is constant.

Unfortunately, however, another factor is to be considered. When the translation system (11) is operated, a certain amount of power is demanded from the diesel motor (13), and consequently, the more power is demanded, the less power is left available to the rotary (10), and thus the value of the control starting pressure and the rotational speed of the rotary are reduced.

With reference to Figs. 5 and 5A, such a problem occurs if the translation system (11 ) has a separate hydraulic circuit from that of the rotary (10) and if it operates in load sensing mode. In such a case, the control starting pressure is lowered from 200 bar to 180 bar.

Referring to Figs. 6 and 6A, the situation worsens when oil for the translation system (11) is taken through a single distributor (15) that also supplies oil for the rotary (10). In such a case, if 500 liters of oil per minute are delivered to the rotary, in the presence of the second use dedicated to the translation system (11 ), only 250 liters per minute may be delivered to the rotary (10), when translation is used, with a drastic decrease in the rotational speed of the rotary (10).

US4137974A describes a drilling machine as in the preamble of the independent claims 1 , 7, and 9.

US2019077641 A1 describes a winch system with energy recovery accumulator. The winch can be used to raise and lower a load and can be used as lifting system for drilling machines.

IT201800003793A1 describes a drilling machine with a winch actuated by an electric motor configured to electrically brake a drilling head during a descending travel with controlled speed.

WO201 7099063 describes a work machine capable of storing the excess energy generated by another system.

The purpose of the present invention is to eliminate the drawbacks of the prior art by providing a drilling machine suitable for optimizing the rotation of the tool.

Another purpose is to provide such a drilling machine that is efficient, effective, and suitable for maintaining the rotational speed of the tool constant, even when power is required for a translation of the tool.

Another purpose is to provide such a drilling machine that is versatile and reliable.

These purposes are achieved in accordance with the invention with the features of the appended independent claims.

Advantageous achievements of the invention appear from the dependent claims.

The drilling machine according to the invention is defined in the independent claims 1 , 7 and 11.

An additional source of energy is provided in the drilling machine according to the invention for the translation of the rotary, without decreasing the power available to the rotary.

The step in which energy can be accumulated is the step b) of the descending travel of the tool. In fact, a load control valve (LCV) is used to lower the tool securely, in such a way that a resisting torque on the hydraulic motor prevents the load from falling. Oil must be sent at a certain pressure that is proportional to the maximum load in such a way for the load to descend. The LCV is dissipative and converts the potential energy of the load into heat.

It has been thought to partialize or even cancel the work of the LCV by using a different resisting torque than the one provided by the valve, in such a way to accumulate, and not dissipate the energy.

Further features of the invention will become clearer from the detailed description that follows, which refers to merely illustrative and thus non-limiting embodiments illustrated in the appended drawings, wherein:

Fig. 1 is a side view of a drilling machine;

Fig. 2 is a block diagrammatic view of a hydraulic system of a drilling machine according to the prior art;

Fig. 3A is a top view of the machine in Fig. 1 during a first drilling step;

Figs. 3B, 3C, and 3D are side views of the drilling machine during a second, a third and a fourth drilling step;

Figs. 3E and 3F are top views of the drilling machine during a fifth and a sixth drilling step;

Fig. 4 is a hydraulic diagram of a drilling machine equipped with two distributors, during the rotation of the rotary;

Fig. 4A is a diagram illustrating the oil pressure as a function of the flow rate in a pump of the hydraulic diagram of Fig. 4;

Fig. 5 is a hydraulic diagram of a drilling machine equipped with two distributors, during the rotation of the rotary and the actuation of the translation system;

Fig. 5A is a diagram illustrating the oil pressure as a function of the flow rate in a pump of the hydraulic diagram of Fig. 5;

Fig. 6 is a hydraulic diagram of a drilling machine equipped with one distributor, during the rotation of the rotary and the actuation of the translation system;

Fig. 6A is a diagram illustrating the oil pressure as a function of the flow rate in a pump of the hydraulic diagram of Fig. 6;

Fig. 7 is a hydraulic diagram of a first embodiment of the invention; Fig. 7 A is a variant of the hydraulic diagram of Fig. 7 with a derated LCV;

Fig. 8 is a variant of the hydraulic diagram of Fig. 7 with an electrical translation system of the rotary;

Fig. 9 is a hydraulic diagram of a second embodiment of the invention during the rotation of the winch;

Fig. 10 is a hydraulic diagram of the second embodiment of the invention during an actuation of the translation system of the rotary;

Fig. 11 is a hydraulic diagram of a third embodiment of the invention during the rotation of the winch; and

Fig. 12 is a hydraulic diagram of the third embodiment of the invention during an actuation of the translation system of the rotary.

Flereafter, elements equal or corresponding to those already described are indicated by the same reference numbers, omitting their detailed description.

With reference to Fig. 7, a drilling machine (100) is illustrated according to a first embodiment of the invention.

At least one main pump (14) is connected to a main motor (13) and to a first distributor (15) hydraulically connected to the hydraulic motor (17) of the winch (7) and to the hydraulic motor (18) for the rotation of the rotary (10). The main motor (13) is generally a diesel motor. By way of example, the main pump (14) may include a first pump (14a) and a second pump (14b).

An auxiliary pump (114) is hydraulically connected to the translation system (11) of the rotary, possibly via a second distributor (16).

An electric motor (20) operating as a generator is arranged in the winch (11) on the opposite side with respect to the hydraulic motor (17) of the winch. The electric motor (20) has a drive shaft connected to a rotating shaft (70) of the winch (7). In such a way, when the winch (7) rotates during the descending travel of the kelly bar, the electric motor (20) produces energy.

The electric motor (20) is electrically connected to an electric accumulator (41) to accumulate electric energy. The electric accumulator (41) can be a battery pack. A second electric motor (40) is connected to the auxiliary pump (141) to operate the auxiliary pump.

The second electric motor (40) is powered through the electric accumulator (41). If the second electric motor (40) is an AC motor, an inverter (42) is arranged between the accumulator (41) and the second electric motor (40).

The hydraulic system includes a first conduit and a second conduit (30a, 30b) that hydraulically connect the first distributor (15) to the hydraulic motor (17) of the winch. The oil goes from the distributor (15) to the hydraulic motor (17) through the first conduit (30a), and from the hydraulic motor (17) to the distributor (15) through the second conduit (30b).

A valve assembly (30) is arranged in the second conduit (30b). The valve assembly (30) includes an LCV (31) and an electrically controlled variable flow valve (32) arranged in parallel with the LCV (31) to derate the LCV.

Referring to Fig. 7A, alternatively, the valve assembly (30) may include an electrically controlled variable flow valve (32) in which the load of the valve is set to a minimum value during the descending travel of the kelly bar. In both cases, the oil from the hydraulic motor (17) of the winch flows almost freely into the second conduit (30b) and bears no load from the valve assembly (30).

The electric motor (20) has a resisting torque to the rotation of the winch (7), in such a way that the electric motor (20) produces electric power during the descending travel of the kelly bar.

Thus, the descending travel of the load of the kelly bar is controlled by the electric motor (20), and not by the LCV.

The second electric motor (40) drives the auxiliary pump (114), which supplies oil to the translation system (11) of the rotary, without requiring power from the diesel motor (13), using the power of the electric accumulator (41) charged by the electric motor (20).

Fig. 8 illustrates a variant, wherein the translation system (11) of the rotary includes electric actuators. In such a case, the auxiliary pump (114) is not required, and the second electric motor (40) directly drives the electric actuators of the translation system (11) of the rotary. With reference to Figs. 9 and 10, a drilling machine (200) according to a second embodiment of the invention is illustrated.

An auxiliary pump (214) is hydraulically connected to the translation system (11) of the rotary in order to operate said translation system (11). The auxiliary pump (214) is of reversible type, that is to say it can operate as a pump in order to pump oil or as a hydraulic motor when it is driven into rotation by the pressurized oil.

The auxiliary pump (214) is mechanically connected to an electric motor (240) connected to an electric accumulator (41), possibly via an inverter (42). The electric motor (240) can operate as a motor to actuate the auxiliary pump or as a generator when it is actuated by the auxiliary pump in order to accumulate energy in the electric accumulator (41).

A first three-way valve (33) is arranged in the second conduit (30b) and is connected to a connecting conduit (30c) connected to the auxiliary pump (214). In this way, the oil from the hydraulic motor (17) of the winch can be directed to the first distributor (15) or to the auxiliary pump (214).

A second three-way valve (34) is arranged in the connecting conduit (30c). A recirculation conduit (30d) connects the second three-way valve (34) to a tank (36). In this way, the auxiliary pump (214) can receive oil from the connecting conduit (30c) or from the tank (36).

A third three-way valve (35) is arranged between the auxiliary pump (214), the tank (36) and the second distributor (16). In this way, the auxiliary pump (214) can send oil to the tank (36) or to the translation system (11 ) of the rotary.

Referring to Fig. 9, during the descending travel of the kelly bar and the rotation of the winch (7), the first three-way valve (33) connects the connecting conduit (30c) with the hydraulic motor (17); the second three-way valve (34) connects the connecting conduit with the auxiliary pump (214); and the third three-way valve (35) connects the auxiliary pump (214) with the tank (36),

In this way, the oil circulates in the auxiliary pump (214) and the auxiliary pump (214) rotates the electric motor (40) in generator configuration mode, producing energy accumulated by the electric accumulator (41). Referring to Fig. 10, during the actuation of the translation system (11) of the rotary, the first three-way valve (33) connects the hydraulic motor (17) with the first distributor (15); the second three-way valve (34) connects the tank (36) with the auxiliary pump (214); and the third three-way valve (35) connects the auxiliary pump (214) with the first distributor (16).

In this way, the electric motor (40), in motor configuration mode, actuates the auxiliary pump (214), which sends the oil to the translation system (11).

With reference to Figs. 11 and 12, a drilling machine (300) according to a third embodiment of the invention is illustrated.

The valve assembly (30) is connected to a connecting conduit (30c) connected to a hydraulic accumulator (50) suitable for being charged to a pressure sufficient to actuate the translation system (11) of the rotary (10).

A one-way valve (33) is arranged in the connecting conduit (30c) to ensure a flow to the hydraulic accumulator (50). The hydraulic accumulator (50) is connected to the distributor (16), which in turn is connected to the translation system (11).

With reference to Fig. 11 , during the descending travel of the kelly bar and the rotation of the winch (7), the oil from the hydraulic motor (17) flows into the hydraulic accumulator (50), which is charged. The valves of the second distributor (16) are closed during such a charging step of the hydraulic accumulator (50).

Referring to Fig. 12, during the actuation of the translation system (11) of the rotary, the valves of the second distributor (16) are opened and the oil contained in the hydraulic accumulator is sent under pressure to the translation system (11 ) in order to operate it.

The drilling machines (100; 200; 300) according to the invention include an energy accumulation system (A) connected to the winch (7) of the kelly bar and to the translation system (11) of the rotary. Such an energy accumulation system (A) accumulates electric or hydraulic energy, during a descending travel of the kelly bar and uses the accumulated energy to actuate the translation system (11) of the rotary. The energy accumulation system (A) of the drilling machines (100; 200) of the first and second embodiments includes the electric accumulator (41).

In the drilling machine (100) of the first embodiment, the electric accumulator (41) is charged by means of the electric motor (20) connected to the rotational shaft (70) of the winch, and the second electric motor (40) actuates the translation system (11).

In the drilling machine (200) of the second embodiment, the electric accumulator (41 ) is charged by means of the electric motor (240) connected to the auxiliary pump (214) connected to the hydraulic motor (17) of the winch, and the electric motor (240) actuates the translation system (11 ).

The energy accumulation system (A) of the drilling machine (300) of the third embodiment includes a hydraulic accumulator (50) that is charged by the hydraulic motor (17) of the winch. In such a case, the hydraulic accumulator (50) actuates the translation system (11). Equivalent variations and modifications may be made to the present embodiment of the invention, within the reach of a person skilled in the art, and still within the scope of the invention as expressed by the appended claims.

Claims

1. Drilling machine (100) comprising:

- a mast (4),

- a kelly bar (6) provided with a drilling tool (12)

- a winch (7) that supports and moves the kelly bar, - a hydraulic motor (17) of the winch,

- a rotary (10) mounted on the mast (4) and connected to the kelly bar in order to rotate the kelly bar,

- a hydraulic motor (18) of the rotary,

- a main motor (13), - at least one main pump (14) actuated by the main motor and hydraulically connected to the hydraulic motors (17, 18) of the winch and of the rotary, and

- a translation system (11 ) of the rotary for translating the rotary, characterized in that it comprises - an energy accumulation system (A) connected to the winch (7) of the kelly bar and to the translation system (11) of the rotary; said energy accumulation system (A) being configured in such away to accumulate electric energy during a descending travel of the kelly bar and use said accumulated energy to actuate the translation system (11 ) of the rotary; wherein said energy accumulation system (A) comprises an electric accumulator (41); and

- an electric motor (20) in generator configuration, mechanically connected to a rotating shaft (70) of the winch and electrically connected to said electric accumulator (41) for charging.

2. The drilling machine (100) of claim 1, comprising a second electric motor (40) connected to said electric accumulator (41) to actuate said translation system (11) of the rotary.

3. The drilling machine (100) of claim 2, wherein said translation system (11) of the rotary is of hydraulic type and the drilling machine also comprises an auxiliary pump (114) actuated by said second electric motor (40) and hydraulically connected to said translation system (11 ).

4. The drilling machine (100) of claim 2, wherein said translation system (11) of the rotary is of electric type and said second electric motor (40) is connected to said translation system (11) of the rotary.

5. The drilling machine (100) according to any one of the preceding claims, comprising:

- a first distributor (15) hydraulically connected to said main pump (14),

- a first conduit and a second conduit (30a, 30b) that hydraulically connect the first distributor (15) to the hydraulic motor (17) of the winch, and

- a valve assembly (30) disposed in said second conduit (30b) to regulate the oil flow from the hydraulic motor (17) of the winch to the first distributor (15).

6. The drilling machine (100) of claim 5, wherein the valve assembly (30) comprises an electrically controlled variable flow rate valve (32).

7. Drilling machine (200) comprising:

- a mast (4),

- a kelly bar (6) provided with a drilling tool (12)

- a winch (7) that supports and moves the kelly bar,

- a hydraulic motor (17) of the winch,

- a hydraulic motor (18) of the rotary,

- a main motor (13),

- at least one main pump (14) actuated by the main motor and hydraulically connected to the hydraulic motors (17, 18) of the winch and of the rotary, and

- a translation system (11 ) of the rotary for translating the rotary, characterized in that it comprises

- an energy accumulation system (A) connected to the winch (7) of the kelly bar and to the translation system (11) of the rotary; said energy accumulation system (A) being configured in such away to accumulate electric energy during a descending travel of the kelly bar and use said accumulated energy to actuate the translation system (11 ) of the rotary; wherein said energy accumulation system (A) comprises an electric accumulator (41).

- an auxiliary pump (214) of reversible type, hydraulically connected to said hydraulic motor (17) of the winch and to said translation system (11 ) of the rotary, and

- an electric motor (240) mechanically connected to said auxiliary pump (214) and to said electric accumulator (41); said electric motor (240) being suitably configured so as to operate as generator when the auxiliary pump (214) receives oil from the hydraulic motor (17) of the winch and from the motor to actuate the auxiliary pump (214) that sends oil to the translation system (11) of the rotary.

8. The drilling machine (200) of claim 7, comprising:

- an oil tank (36),

- a first three-way valve (33) to enable an oil flow from the hydraulic motor (17) of the winch to said auxiliary pump (214) or to said main pump (14),

- a second three-way valve (34) to enable an oil flow towards the auxiliary pump (114) from the hydraulic motor (17) of the winch or from the tank (36), and

- a third three-way valve (35) to enable an oil flow from the auxiliary pump (214) towards the tank (36) or towards the translation system (11) of the rotary.

9. The drilling machine (200) of claim 7 or 8, comprising:

- a first distributor (15) hydraulically connected to said main pump (14),

10. The drilling machine (200) of claim 9, wherein the valve assembly (30) comprises an electrically controlled variable flow rate valve (32).

11. Drilling machine (300) comprising:

- a mast (4),

- a kelly bar (6) provided with a drilling tool (12) - a winch (7) that supports and moves the kelly bar,

- a hydraulic motor (17) of the winch,

- a hydraulic motor (18) of the rotary,

- a main motor (13),

- a translation system (11 ) of the rotary for translating the rotary, characterized in that it comprises an energy accumulation system (A) connected to the winch (7) of the kelly bar and to the translation system (11 ) of the rotary; said energy accumulation system (A) being configured in such away to accumulate electric energy during a descending travel of the kelly bar and use said accumulated energy to actuate the translation system (11) of the rotary; wherein said energy accumulation system (A) comprises an electric accumulator (50) hydraulically connected to the auxiliary motor (17) of the winch and to the translation system (11) of the rotary and suitable for accumulating oil at a pressure sufficient to actuate said translation system (11) of the rotary.

12. The drilling machine (300) of claim 11 , comprising:

- a first distributor (15) hydraulically connected to said main pump (14),

13. The drilling machine (300) of claim 12, wherein the valve assembly (30) comprises an electrically controlled variable flow rate valve (32).