The invention is related to a system for drilling a borehole into a base, preferably a gravel or paved road, most preferably a paved road, with the system including

- a drill apparatus for drilling a 10 - 100 cm deep borehole into a base, wherein the drill apparatus includes a frame, a motor and a blade rotated by means of the motor mounted on the frame, and

- a work machine for supporting and operating the drill apparatus. The invention is also related to a drill apparatus and a method for drilling a borehole into a base.

Publication FI 128292 B representing prior art proposes a system for drilling a borehole into a base for an anti-tank mine. This system includes a timber or bulk crane and a loading grab suspended to its end as well as a drill apparatus operated by the loading grab. A problem with such a solution, when used by the defence forces, is that the drill apparatus is an additional component to the equipment, which must fit in a limited container space so that it can be quickly moved from one place to another. A separate drill apparatus takes a lot of transport capacity when not in use. In addition, operation of the drill apparatus requires a heavy work machine.

Publication US 4099579 A proposes a system for drilling a borehole into a base and a corresponding drill apparatus and a method for drilling a borehole. The system includes a drill apparatus for drilling a borehole into a base. The drill apparatus includes a frame, a motor mounted on this and a blade mounted on the motor. In addition, the system includes a work machine for supporting and operating the drill apparatus. The work machine is a work machine equipped with a front loader, wherein the front loader includes first connection equipment for attaching an optional attachment to the front loader, and the frame of the drill apparatus further includes second connection equipment for attaching the drill apparatus to the first connection equipment of the front loader.

Publication US 5868211 A proposes a system for drilling a borehole into a base and a corresponding drill apparatus and a method for drilling a borehole. In the system, the drill apparatus is attached to a bucket mounted on a loader.

Publication US 5437341 A proposes a system for drilling a borehole into a base and a corresponding drill apparatus and a method for drilling a borehole. The system utilises a separate frame, via which it is possible to mount several attachments on a loader.

The object of the invention is to provide a system, a drill and a method, wherein the drill apparatus is easily transported with transport equipment and wherein the drill apparatus can be used in a more versatile way with varying equipment. The characteristic features of the system according to the invention appear from the appended claim 1, the characteristic features of the drill apparatus from claim 5 and those of the method from claim 11.

This object can be achieved with a system for drilling a borehole into a base, preferably a gravel or paved road, most preferably a paved road, the system including a drill apparatus for drilling a 10 - 100 cm deep borehole into a base, and a work machine equipped with a loader, preferably a front or rear loader, for supporting and operating the drill apparatus. The loader includes first connection equipment for attaching an optional attachment to the front loader. The drill apparatus includes a frame, a motor mounted on the frame, a blade rotated by means of the motor, second connection equipment for attaching the drill apparatus to the first connection equipment of the loader and third connection equipment for mounting an optional attachment on the loader via the drill apparatus.

In this context, the base preferably means any soil, even an asphalted or concrete base, and the soil need not be soft, for example, a field or other previously processed soil.

Preferably, the borehole is intended for an explosive.

Most preferably, the drill apparatus is suspended to the front loader of a work machine thus making it easy for the work machine driver to control the operation of the drill apparatus in the driving direction.

In the system according to the invention, the drill apparatus is operable with a conventional tractor or a wheel loader and simultaneously easily transportable while mounted on the loader. Several work machines are available for operating a drill apparatus and they need not be special work machines specifically designed for operating a drill apparatus. In the system according to the invention, the drill apparatus can be mounted on the front loader simultaneously with an optional attachment. Thus, for example, a bucket used for transporting anti-tank mines can be mounted on the front loader via the drill apparatus, in which case moving anti-tank mines to the borehole and covering them remain the only manual task. In the system, a separate load space is not needed for transporting the drill apparatus, but the drill apparatus can be easily carried along, even though an optional attachment would be mainly used on the front loader. In this way, the system according to the invention offers a logistically first-class solution for using the drill apparatus.

Alternatively, a drill apparatus according to the invention can also be used in a truck instead of a plough.

Preferably, first, second and third connection equipment and the connection equipment for an optional attachment are generally known quick connection equipment. Most preferably, connection equipment are attached using a separate actuator, which makes it quick to use them; i.e. , the connection equipment are quick connection equipment.

In the system according to the invention, the work machine is preferably a general-purpose work machine suitable for road traffic use and equipped with first connection equipment, most preferably a tractor or a wheel loader, and the optional attachment consists of fork arms or a bucket. With these, it is possible to realise a system that operates in an extremely versatile manner for installing explosives into the ground when constructing blockage.

The system preferably includes a set of different second connection equipment and third connection equipment, which are replaceable in the drill apparatus for adapting it to suit first connection equipment of different manufacturers or to suit work tools of different manufacturers.

Preferably, the set includes bolt connection equipment for removably attaching second connection equipment and third connection equipment to the frame of the drill apparatus so that replacement of second and third connection equipment with suitable models per each manufacturer is quick and simple .

The height of the drill apparatus may range between 80 and 150 cm, preferably between 100 and 120 cm. Thus, the drill apparatus can be easily moved with a work machine.

The object of the drill apparatus according to the invention can be achieved with a drill apparatus for drilling a borehole into a base, preferably a gravel or paved road, most preferably a paved road, wherein the system includes a frame, a motor mounted on the frame, and a blade, which is arranged to be rotated by the motor for drilling a 10 - 100 cm deep borehole. The frame further includes second connection equipment for mounting the drill apparatus on a work machine supporting the drill apparatus, on first connection equipment included in a loader, preferably a front or rear loader, and further, third connection equipment for mounting an optional attachment on the front loader via the drill apparatus.

A drill apparatus according to the invention is easily transported with the work machine and does not prevent the use of the front loader of the work machine for the original purpose of use. A drill apparatus according to the invention can also be used on conventional tractors and wheel loaders; thus, suitable equipment is widely available. A drill apparatus according to the invention can also be used for civilian purposes, for example, as a soil auger, for drilling foundations or for pillar installations.

Preferably, the drill apparatus additionally includes a gear for reducing the running speed of the motor in the ratio of 1:5 - 1:15, wherein the motor is a hydraulic motor with a running speed of 800 - 1200 rpm. Thus, the rotational speed of the blade can range between 30 and 100 rpm, the blade thus proceeding thanks to a high torque without causing strong vibrations and lateral tearing forces to the frame of the drill apparatus and therethrough to the front loader and the work machine.

The drill apparatus preferably includes extraction devices for emptying the borehole drilled during drilling. Thus, the engineer does not need to empty the borehole with a shovel before installing an anti-tank mine or other explosive, but the installation is made quicker. On the other hand, in other applications, the borehole is also immediately ready to use without a separate extraction step.

Extraction devices can consist of a cup construction included in the blade of the drill apparatus for collecting soil drilled on top of the blade for removal when lifting the blade. With such a blade, the borehole can be emptied in a simple way and reliably.

According to an embodiment, the blade consists of a pilot blade forming the axis of rotation and blade cutouts connected to it in the radial direction and in a helical form, where the angle between the blade cutouts and the pilot blade is 70 - 85° in such a way that the edge of the blade cutouts attached to the pilot blade is closer to the tip of the pilot blade than the outer edge of the blade cutouts. In other words, blade cutouts form a cup-like construction, which guides loose material detaching from the soil during drilling towards the pilot blade.

The frame of the drill apparatus can include guides, vertical in the operating position, and a carriage arranged on the guides, onto which the motor and the blade are arranged movably in the vertical direction. With the carriage and guides, the frame of the drill apparatus can be supported against the base before starting drilling by pushing the drill apparatus against the base with the front loader. Thus, friction parallel to the base of the drill apparatus increases and prevents movements of the drill apparatus in the direction of the base during drilling.

In addition, the drill apparatus can include a push cylinder arranged between the frame and the carriage for moving the carriage and the blade attached thereto in the vertical direction and for loading them against the base that is to be drilled .

Alternatively, the drill apparatus can include a pivot mechanism, with which the pushing of the drill apparatus against the base, provided with the front loader, is changed to a movement that pushes the carriage against the base. An alternative for this is to use, associated with the frame, a cylinder, the piston rod of which moves when the drill apparatus is pushed against the base, and this piston rod movement generates a pressure on the cylinder side, conveyed to a transfer cylinder that moves the carriage.

Second connection equipment are preferably arranged to suspend the drill apparatus onto the work machine in such a way that the drill apparatus is essentially perpendicular relative to the base on which the work machine moves.

Second connection equipment preferably consist of an adapter plate, which can be removably attached to the drill apparatus and is equipped with connection hooks. According to an embodiment, the drill apparatus includes a flow divider valve or a relief valve arranged to supply 85% - 99% of the flow to the motor that rotates the blade and 1% - 15% of the flow to the push cylinder depending on the speed of rotation of the motor for adjusting the push of the blade. In this way, it is possible to realise a simple safety system, which prevents the blade from stopping due to excessive pushing.

When implemented with a flow divider valve or a relief valve, the system does not reguire sensors and electronics to work but works according to natural laws.

According to an alternative embodiment that uses a relief valve, the relief valve is used in the drill apparatus to stop the hydraulic flow supplied to at least one, preferably two push cylinders, and parallel to the flow supplied to the motor, when the pressure of the hydraulic flow before the motor exceeds the threshold as the blade contacts hard soil. In this way, it can be ensured that the rotational speed of the blade will never slow down too much as a conseguence of pushing regardless of soil. On the other hand, when two push cylinders are used, the pressure level required by an individual push cylinder is lower, and thus the motor can also be operated with a lower pressure level, which reacts more sensitively to hard soil thus relieving pushing.

Advantageously, the drill apparatus includes a support bearing arranged between the blade and the motor to support the blade to the carriage. Thus, forces acting on the blade during drilling cannot be directly conveyed to the motor and gear system bearings, which improves their durability. The support bearing is preferably a tapered roller bearing.

This bearing type is very common and resists well loads applied to it even when drilling hard soil.

Advantageously, the drill apparatus includes hydraulic connections for connecting drill apparatus hydraulics to the hydraulic outlet of the work machine for providing a hydraulic flow for the drill apparatus. Therefore, the drill apparatus does not need a hydraulic unit of its own for operating the motor and push cylinders and is thus more affordable to manufacture and has a lighter construction.

The object of the method according to the invention can be achieved with a method for drilling a borehole into a base, preferably a gravel or paved road, most preferably a paved road, wherein a borehole is drilled using a drill apparatus and a work machine in successive steps of supporting the drill apparatus to the loader of the work machine, preferably a front or rear loader, and further an optional attachment to the front loader via the drill apparatus for transporting explosives, and drilling a borehole into the base with the drill apparatus. In the method according to the invention, the drill apparatus for drilling a hole for an explosive can be transported with the work machine without preventing the use of an optional attachment. Thus, transporting the drill apparatus is easy and there is no need to reserve a separate space for it from the load space when not in use. On the other hand, when installing explosives, it is very useful that heavy anti-tank mines, for example, can be transported, for instance, in a bucket that serves as an optional attachment with the drill apparatus simultaneously mounted on the front loader. The pavement is preferably asphalt. With the method according to the invention, drilling a borehole into an asphalt road can also be performed without problems without pre-processing the surface for drilling.

In the method, material that detaches during drilling is preferably lifted away from the borehole with the drill apparatus. Thus, the borehole is instantly ready for use for the installation of an explosive without emptying the borehole with a shovel. This accelerates the installation of explosives .

In the method, the drill apparatus is preferably pushed against the base with the front loader of the work machine in order to prevent movements of the drill apparatus parallel to the base. In this way, it is prevented that lateral forces are conveyed to the front loader.

The blade is preferably rotated at a rotational speed of 30 - 100 rpm during drilling. Then the blade does not generate strong lateral forces to the frame of the drill apparatus and therethrough to the front loader of the work machine.

In the method, the supply pressure of the motor is preferably monitored, based on which blade pushing is controlled with push cylinders. This can prevent excessive deceleration of the blade rotation, which would slow down drilling and increase load on the transmission.

According to an embodiment, 85% - 99% of the flow is supplied to the motor that rotates the blade and 1% - 15% of the flow to the push cylinder according to the speed of rotation of the motor for adjusting the blade pushing. Advantageously, hydraulic flow from the work machine is used in the motor of the drill apparatus and the push cylinder. This makes it possible to realise the drill apparatus without a separate hydraulic unit for the drill apparatus, which makes the drill apparatus more affordable to manufacture and lighter in weight.

With the system, drill apparatus and method according to the invention, it is possible to achieve a reliable and easily implement able solution for installation of explosives, since work machines suitable for using the drill apparatus are widely used in the agriculture, industry and road maintenance. On the other hand, the drill apparatus and the system can be used in peacetime conditions for different foundation works as well as for piling and pillar mounting.

In this context, it should be understood that the drill apparatus according to the invention is not percussive nor does it use a separate flushing agent flow, but a borehole is created solely by rotating the blade and the borehole is cleaned with extraction devices, preferably by means of a cup-like construction of the blade.

The invention is described below in detail with reference to the accompanying drawings that illustrate some of the embodiments of the invention, in which

Figure la is a lateral view of the first embodiment of the system according to the invention before drilling,

Figure lb is a lateral view of the first embodiment of the system according to the invention after drilling, Figure 2 is an axonometric view of the first embodiment of the drill apparatus according to the invention, from the direction of the attachment ,

Figure 3 is a direct view of the first embodiment of the drill apparatus according to the invention, from the direction of the attachment ,

Figure 4 is a direct view of the first embodiment of the drill apparatus according to the invention, from the direction of the attachment ,

Figure 5 is a direct top view of the first embodiment of the drill apparatus according to the invention,

Figure 6 is a direct bottom view of the first embodiment of the drill apparatus according to the invention,

Figure 7 is a direct lateral view of the first embodiment of the drill apparatus according to the invention,

Figure 8 is a partially exploded axonometric view of the main components of the first embodiment of the system according to the invention,

Figure 9 is a partially exploded lateral view of the motor, gear and blade of the first embodiment of the drill apparatus,

Figure 10a is a separate axonometric view of the blade of the first embodiment of the drill apparatus,

Figure 10b is a separate bottom view of the blade of the first embodiment of the drill apparatus,

Figure 10c is a separate top view of the blade of the first embodiment of the drill apparatus, Figure Ila is a basic hydraulic diagram of the operation of the motor and the push cylinder,

Figure 11b is a basic hydraulic diagram of the operation of the motor and the push cylinder, alternative relative to Figure 10a,

Figure 12 is a partially exploded axonometric view of the second embodiment of the drill apparatus according to the invention,

Figure 13 is a top view of the second embodiment of the drill apparatus according to the invention,

Figure 14 is a separate lateral view of the motor, gear and blade of the second embodiment of the drill apparatus,

Figure 15 is a separate lateral view of the blade of the second embodiment of the drill apparatus,

Figure 16a is a direct view of the second embodiment of the drill apparatus according to the invention, from the direction of the attachment when the carriage is up,

Figure 16b is a direct view of the second embodiment of the drill apparatus according to the invention, from the direction of the attachment when the carriage is down,

Figure 17 is a block diagram illustrating the steps of the method according to the invention,

Figure 18 is a direct view of the third embodiment of the drill apparatus according to the invention, from the direction of the attachment .

The following reference numbers are used in the figures:

10 system 35 16 motor

12 drill apparatus 18 blade

14 frame 20 work machine 22 front loader 58 transverse frame

24 first connection 35 plate equipment 60 spacer plate

26 optional attachment 61 support legs

28 second connection 62 adapter for second equipment connection

30 third connection 40 equipment equipment 64 end plate

32 gear 65 manifold

33 support bearing 66 bottom plate

34 extraction devices 67 load control valve

36 cup-like 45 68 cover plate construction 70 front loader

38 guides cylinders

40 carriage 72 connection

42 push cylinder equipment for

44 flow divider valve 50 optional attachment

45 relief valve 74 first arms of front

45 second relief valve loader

46 lug for support 76 second arms of pillars front loader

48 upper lug of push 55 78 forks cylinder 80 motor mounting

49 depth meter bolts

50 bolt connection 82 blade mounting equipment bolts

51 arm 60 84 blade bits

52 bolt holes 86 pilot blade

53 support plate 88 blade mounting

54 second bolt holes flange

55 box construction 90 motor drive shaft

56 vertical frame 65 92 holes for blade plate mounting flange 94 end flange for cup- 102 base like construction 104 pavement

96 blade bit guides

98 blade cutouts 100 borehole

As shown in figures la and lb, the system 10 according to the invention includes a work machine 20, such as a wheel loader according to figures la and lb, having a drill apparatus 12 according to the invention mounted on its front loader 22 using the first connection equipment 24 of the front loader 22. Thus, the drill apparatus 12 is attached to the first connection equipment 24 by means of second connection equipment 28 included in the drill apparatus 12. The drill apparatus 12 includes a frame 12, a motor 16 and a blade 18. The design of the first embodiment of the drill apparatus 12 is illustrated in more detail in figures 2 - 10c.

As shown in figures la and lb, the drill apparatus 12 allows an optional attachment 26 to be mounted on the front loader 22 of a work machine 20 via the drill apparatus 12 using third connection equipment 30 included in the drill apparatus 12 and connection equipment 72 of the optional attachment 26, illustrated in more detail in figure 8, included in the optional attachment 36. As shown in figure lb, the system 10 according to the invention is very easily movable with a work machine 20 driven on wheels to the site of application, where a borehole 100 is drilled into a base. The base can preferably be a gravel road or, most preferably, a paved road, onto the surface of which it is extremely difficult to make a hole. With the system 10, method and drill apparatus 12 according to the invention, the borehole 100 can be made, as shown in figure lb, into a base 102 easily and quickly, even in 30 seconds, after which the borehole is instantly ready to use for installing an explosive in the borehole without removing drill cuttings from the borehole.

A more detailed design of the first embodiment of the drill apparatus is illustrated in figures 2 - 10c. The frame 14 of the drill apparatus consists of an end plate 64, shown in figure 4, vertical plates 56 welded to the end plate 64 at a distance from each other, bottom plates 66 attached to the vertical plates and the end plate 64 on both sides of the vertical plates 56, and cover plates 68 shown in figure 3, transverse plates 58 that connect the vertical plates 58 to each other and spacer plates 60, which are preferably removably attached to the end plate 64 in the transverse direction. Second connection equipment 28 for attaching the drill apparatus 12 to first connection equipment 24 of the front loader of the work machine are preferably removably connected to the end plate 64, as shown in figure 4. In turn, third connection equipment 30 for attaching an optional attachment to the front loader via the drill apparatus 12 are preferably formed in the spacer plates 60.

The vertical plates 56 are provided with vertical guides 38 in the form of a slot, having a carriage 40 arranged therein. The purpose of the carriage is to support the motor 16 and the gear system 32 to the carriage 40 by means of a flange 44 in such a way that the carriage 40 is movable on the guides 38 with a push cylinder 42. The push cylinder 42 is mounted between the transverse plates 58 with a lug 48 and, on the other hand, also to the carriage 40. The drill apparatus 12 preferably includes a gear 32 between the motor 16 and the blade 18, attached to the blade 18 via an intermediate shaft 44 through the carriage 40. With the guides 38 and the carriage 40, the blade 18 is movable in the operating position in the vertical direction relative to the frame 14, although the frame 14 is lowered and pushed against the base with the front loader of the work machine.

The drill apparatus 12 can also include lugs 46 for support pillars, attached to the end of the cover plates 68 and the bottom plates 66 as well as to the edges of the end plate 64. Between the lugs 46 for support pillars, it is possible to place support pillars (not shown) , which go through both lugs and settle against the base, when the drill apparatus 12 has been lowered and pushed against the base. Then, the sharp tips of the support pillars are supported to the base preventing movements of the drill apparatus in the direction of the base during drilling. The use of support pillars is not necessary, if the drill apparatus is vigorously pushed against the base, the friction then being sufficient to keep the drill apparatus in place.

Figure 9 is a more detailed lateral view of the design of the blade 18 of the drill apparatus 12 according to the invention and its transmission. The blade 18 is rotated by a high-speed hydraulic motor 16, preferably via a gear 32. High-speed hydraulic motors can be operated using the output of the hydraulic pump of a tractor or a wheel loader used as the work machine. This makes it possible to realise the drill apparatus without a separate hydraulic unit for the drill apparatus, which makes the drill apparatus more affordable to manufacture and lighter in weight. In turn, the gear 32 is a gear system equipped with a gearing of 1:5 - 1:15, with which the motor's speed of rotation of 800 - 1200 rpm can be reduced to the blade's rotational speed of 30 - 100 rpm. Thus, the drilling of the blade into the base does not cause strong lateral forces, which could generate strong lateral stresses to the front loader. For example, the gear system used can be Brevini ED2045/MR1 / 11 , 2 / 00. Alternatively, the blade of a drill apparatus according to the invention can also be operated with an electric motor, in which case the implementation is possible even without a gear system using a frequency converter.

The drill apparatus preferably also includes extraction devices for emptying the borehole during drilling. For example, extraction devices can be realised with a spirallike threaded construction or separate suction equipment; however, extraction devices most preferably consist of a cuplike construction 36 formed in the blade 18, better shown in figure 10a. The blade 18 consists of a pilot blade 86, a flange 88 attached thereto at one end for attaching the blade 18 to a spacer shaft, and blade cutouts 98 that are radially attached to the other end and form a cup-like construction 36. Blade cutouts 98 are placed in a form of a spiral or a thread, extending to the end flanges 94 of figure 10a at the upper end of the spiral, the construction thus forming a cup that collects drill cuttings on top of the blade 18. In this way, drill cuttings can be lifted out from the borehole along with the blade without a separate borehole cleaning step.

In turn, at the bottom end of the spiral, the outermost blade cutout 98 has blade bit guides 96 attached thereto for attaching blade bits 84. The blade bits 84 contact the base to be drilled. The blade bits 84 are wear-resistant hard steel components, which are replaceable together with the blade bit guides 96. For example, the blade bits can be blade bits known from ploughs. At the centre of the blade, a pilot blade 86 forms an initial hole and facilitates the piercing of the blade bits into the base. The blade preferably includes different blade bit guides 96, the shorter ones of which are intended to remove material between the longer blade bit guides 96 and the pilot blade 86, as shown in figure 10b. Alternatively, whe drilling soft soil, the blade can also be realised without separate wear-resistant steel blade bits .

Figure Ila depicts the first embodiment of the hydraulic control for pushing the push cylinder 42 by using a flow divider valve 44 in the inlet line A to supply 85% - 99% of the flow to the hydraulic motor 16 and the rest 1% - 15% to the push cylinder for pushing the blade against the base. If a hard point, at which the blade does not penetrate the base in a normal way, is encountered in the base, the pressure in the line C arriving to the push cylinder 42 increases until it exceeds a preset limit pressure and a relief valve 45 opens. Then the pressure on the piston side of the push cylinder decreases relieving pushing so that the motor's speed of rotation cannot decrease when hitting hard points. Inlet line B is used when it is desired to lift the blade up after drilling; then the push cylinder draws the carriage and the blade connected thereto out from the borehole. The movement direction of the push cylinder is controlled with a directional valve 47.

Figure 11b depicts the second embodiment of the hydraulic control for pushing the push cylinder 42. In this preferred embodiment, the number of push cylinders 42 is two, in which case, the force required from an individual push cylinder is only a half of the force required from one push cylinder of the embodiment of figure Ila. Thus, the pressure needed for push cylinders is half smaller. When the blade hits hard soil, the pressure increases at the motor 16, and the same is true for the push cylinders' supply line D connected parallel with the motor 16. When the pressure exceeds the threshold, a second relief valve 45' closes the line, which stops pushing and relieves the motor operation. Such an embodiment is better than the embodiment of figure Ila because, in the embodiment of figure Ila, the pressure required by the push cylinder is so high that a motor operating at the same operating pressure rarely decelerates even at a hard point. Thus, relieving pushing also operates poorly. In the embodiment of figure 11b, the pressure increase is percentually higher at a hard point and thus relieving is more sensitive. To improve safety, the embodiment of figure 11b has been additionally provided with a load control valve 67, which prevents the carriage from falling in an uncontrolled way in the event that the pressure line fails or the line is disconnected.

The adapters 62 for the second connection equipment 28 shown in figure 4 and the third connection equipment formed in the spacer plates 60 illustrated in figures 2, 7 and 8 are preferably a part of a set, which includes several different adapters for second connection equipment 28 and spacer plates, which are preferably removably mountable with bolts to the bolt holes 52 and 54. Since different work machine manufacturers have different standards for the first connection equipment of a front loader and, correspondingly, for the connection equipment of an optional attachment, the spacer plates and adapters 28 of the second connection equipment 28 are replaceable with versions manufactured according to a different standard based on the application. Preferably, bolt connection equipment, which are easy and quick to disconnect and connect, are used for attaching.

Figures 12 - 15 illustrate the second embodiment of the drill apparatus 12 according to the invention, which is mainly similar to the first embodiment. As shown in figure 12, instead of the spacer plates of the first embodiment, in the second embodiment, the frame 14 is provided, on both sides of the vertical supports 56, with preferably openable box constructions 55, to which third connection equipment 30 are attached. The box constructions 55 can serve as storage boxes for tools or explosives, for example, while simultaneously stiffening the frame 14 of the drill apparatus 12 as box constructions. In addition, foldable support legs 61 are preferably pivoted to the flanks of the box constructions 55 to improve the staying in place of the drill apparatus 12 during drilling. Due to the use of box constructions 55, the third connection equipment 30 formed at the end of the spacer plates in the first embodiment, are formed in separate bottom plates 31 in the second embodiment, as shown in figure 12.

As shown in figures 12 and 14, a drill apparatus 12 according to the invention can include a depth meter 49, also included in the second embodiment, which is an arm 51 connected to the carriage 40 and runs through the support plate 53 while the support plate 53 serves as in indicator for a scale preferably arranged in the arm 51. Alternatively, the arm can have two parts in such a way that it can be installed in a transport position, where it takes much less space in the vertical direction, such as in the third embodiment of the drill apparatus shown in figure 18.

In the second embodiment of figures 12 - 16b, a manifold 65 is used in the hydraulic system, placed on top of the box construction 55 on the vertical frame plate 56, as shown in figure 13, where it is easy to service.

The second embodiment differs from the first embodiment also related to the supporting of the motor 16 of the blade 18 and the gear system 32. According to figure 14, a support bearing 33 supported to the carriage 40 is provided between the gear system 32 and the blade 18. With the support bearing 33, the transmission composed of the motor 16 and the gear system 32 can be supported in two points to the carriage 40 shown in figure 14 with both the motor 16 and the support bearing 33 so that loads applied to the blade 18 are not directly conveyed to the bearings of the motor 16 and the gear system 32 thus stressing these. In order that a borehole can be drilled with the system into an extremely hard soil, the drill apparatus must be able to resist high loads. Part of the resistance comes from the selected support bearing 33, which is preferably a tapered roller bearing. Tapered roller bearings can reliably receive high loads. On the other hand, the use of a gear system enables generation of high forces with a hydraulic motor.

As shown in figure 15, in the second embodiment, the blade 18 is preferably higher in the longitudinal direction of the pilot blade 86 or, in other words, the blade 18 has a longer thread, which enables collection of a larger amount of material into the cup-like construction 36 of the blade 18. Hence, the drill apparatus can be used to drill a deeper borehole and, at the same time, to empty the borehole from drill cuttings without a separate extraction step. The length of the blade 18 of the second embodiment from the tip of the pilot blade 86 to the mounting flange 88 can be in the range of 40 - 60 cm, preferably 45 - 55 cm, and the number of blade cutouts can be 4 - 6 on one side of the spiral, welded together on their sides successively.

The depth of the hole drilled with the system, drill apparatus and method according to the invention is in the range of 10 - 100 cm, preferably 30 - 60 cm, which enables placing different explosives, such as anti-tank mines, destructive projectiles or other explosives, used for blockage, for example, to a suitable depth in the borehole. The blade diameter can be in the range of 30 - 80 cm, preferably 40 - 60 cm. The width of the drill apparatus can be in the range of 100 - 200 cm, preferably 120 - 150 cm, height in the range of 80 - 150 cm, preferably 100 - 120 cm and depth in the range of 60 - 120 cm, preferably 80 - 100 cm .

The pressure level of hydraulics used in the drill apparatus according to the invention is preferably between 100 bar and 400 bar, preferably 120 - 220 bar and the motor output between 20 kW and 50 kW. The maximum pressure level that the work machine's hydraulic unit can generate and is available for the motor of the drill apparatus is preferably used. The driving motor can have a cylinder capacity of 250 cm ³ , for example .

Figure 17 is a block diagram illustrating the steps of the method according to the invention. Preferably, the method starts in step 200 by attaching the drill apparatus, using the second connection equipment, to the first connection equipment of the front loader of the work machine and by attaching an optional attachment to the drill apparatus with the third connection equipment of the drill apparatus. In this way, the work machine can be used to simultaneously move the drill apparatus and a bucket, for example, as an optional attachment, wherein objects, preferably explosives, to be drilled into the soil can be placed. In step 202, the drill apparatus is moved to the point in which the borehole is to be made, using the work machine. For example, when installing anti-tank mines for blockage, the drill apparatus is moved to the point in the road, where the anti-tank mine is to be located. At the same time, anti-tank mines are transported in the bucket with the work machine. The actual drilling step starts in step 204 by lowering the drill apparatus against the ground with the front loader. At the same time, the drill apparatus is pushed against the ground with the front loader in order to prevent movements of the drill apparatus in the direction of the base during drilling. In addition, in this step, it is possible to use, if necessary, support pillars according to the first embodiment or support legs according to the second embodiment for supporting the drill apparatus more robustly against the ground .

When the drill apparatus is robustly supported against the base, the blade rotation can be started in step 206 and the rotating blade can be pushed against the base with the push cylinder. The blade moves on the guides pushed by the push cylinder by means of the carriage towards the base while the blade simultaneously lifts and collects soil to the cup-like construction of the blade. When a sufficient borehole depth has been achieved, lifting the blade from the borehole is started with the push cylinder in step 208. Blade rotation can be stopped during this step so that detached soil is kept in the cup-like construction of the blade. In this way, the borehole is emptied during the lifting of the blade. In step 210, drill cuttings are extracted from the cup-like construction of the blade and, in step 212, an anti-tank mine can be placed in the borehole and covered. After this, it is possible to return to step 202 and move to the next step for drilling a new borehole. Blade extraction can be performed with the front loader by shaking.

Figure 18 depicts the third embodiment of the drill apparatus, which differs from the second embodiment of figures 12 - 16b regarding push cylinders and the depth meter. In the third embodiment, there are two push cylinders to relieve the force required from a single push cylinder. On the other hand, the depth meter 49 is preferably such that it can be folded in a telescopic manner for transportation.