Patent Description:
In exploration drilling, drill holes are drilled in the bedrock, and specimens sampled from the drill holes are used to assess the composition and ore concentrations of the bedrock. Drilling is carried out with a drilling machine having a boom and a rotating unit moving parallel to the boom, by means of which drill pipes are drilled into the bedrock. In exploration drilling, the drilling depth can be several hundred, even thousands of meters. The individual drill pipes used in a drilling machine are typically <NUM>-<NUM> meters long. When drilling, it is thus necessary to connect the individual drill pipes into a drill string that reaches the desired drilling depth. At the end of the first drill pipe in the drill string there is a drill bit that must be replaced from time to time. To replace the bit, the entire drill string must normally be lifted up from the drill hole and disassembled into individual drill pipes. After replacing the drill bit, the drill string is lowered back into the drill hole. The time taken to connect and disconnect the drill pipes thus has a significant impact on the output of the drilling machine.

Drill pipe handling devices have been developed for the handling of drill pipes to facilitate and speed up the connection and disconnection of drill pipes. Known drill pipe handling devices comprise an auxiliary guide attached in parallel with the drilling machine boom and a drill pipe gripper which moves along the auxiliary guide. The gripper grips the drill pipe on the side of the drilling machine and moves it within the reach of the rotating unit moving along the upper surface of the boom. Disconnecting the drill pipes from the drill string takes place in the reverse way. Some prior art drill pipe handling devices are disclosed in publications <CIT>, <CIT>, <CIT> <CIT>, <CIT> and <CIT>.

Known drill pipe handling devices are suspended from the drilling machine boom, whereby their weight puts a strain on the boom. The attachment of the handling devices to the side of the boom results in an eccentric load and causes a torsional stress on the boom and in particular on the attachment joint between the boom and the drilling machine. Moving the drill pipe from the side of the boom along a curved trajectory over the top surface of the boom requires a complex transfer mechanism, which increases the weight and manufacturing cost of the handling equipment. Known drill pipe handling devices also increase the overall width of the drilling unit consisting of the drilling machine and the drill pipe handling device. Often, the drilling machine is placed on the platform or frame of an off-road vehicle, whereby the space required by the drill pipe handling equipment on the side of the boom makes it difficult to operate the drilling machine and poses an occupational safety risk.

An object of the invention is to provide a drilling unit with which the disadvantages associated with the prior art can be reduced. The objects of the invention are achieved by a drilling unit which is characterized by what is set out in the independent claim. Some preferred embodiments of the invention are set out in the dependent claims.

The invention relates to a drilling unit according to claim <NUM>.

A preferred embodiment of the drilling unit according to the invention further comprises a drill pipe handling device with an elongate support arm for supporting the drill pipe, the support arm being arranged to pivot about an imaginary axis of rotation along a trajectory in one plane. Preferably, the rotating unit is below the boom and the support arm is on the rotating unit side of the boom. The rotating unit is thus in the area between the boom and the support arm. The drill pipe handling device is used to move drill pipes to the rotating unit and to remove drill pipes from the rotating unit. When the support arm supporting the drill pipes is on the same side of the boom as the rotating unit, the drill pipe supported by the support arm can move to the rotating unit along a trajectory in one plane.

In another preferred embodiment of the drilling unit according to the invention, the support arm is pivotally attached to an axle at its first end. The support arm and boom thus rotate about the same axle. The drill pipe supported on the support arm and the rotating unit supported on the boom can then be arranged to move in a plane.

In another preferred embodiment of the drilling unit according to the invention, the support arm has a head end and a tail end and the support arm is pivotable to a first position in which the tail end is substantially horizontal. Depending on the position of the boom, the support arm then forms either a right angle or an acute angle with the boom. Preferably, in a first position, the head end and tail end of the support arm are substantially parallel. The support arm is turned to the first position when drill pipes are being moved on the support arm from a drill pipe rack or storage.

In another preferred embodiment of the drilling unit according to the invention, the support arm can be brought into a second position in which the tail end is substantially parallel to the boom. Preferably, in the second position, the imaginary central axis of the drill pipe supported by the support arm and the imaginary central axis of the drill pipe rotated by the rotating unit are parallel and aligned. In the second position, the head end and tail end of the support arm may be non-parallel.

In another preferred embodiment of the drilling unit according to the invention, the head end of the support arm is attached at its second end rotatably around a pivot pin to the first end of the tail end, and the drilling unit has an actuator for turning the tail end relative to the head end and for turning the support arm about an axle. Thus, turning the tail end of the support arm around the pivot pin and turning the entire support arm about the axle is carried out by means of the same actuator. Preferably, said actuator is a hydraulic cylinder having a first end engaging the frame and a second end engaging the tail end of the support arm.

In another preferred embodiment of the drilling unit according to the invention, the drill pipe handling device has a rotating mechanism for rotating the drill pipe about its imaginary central axis. The rotating mechanism is used to tightly screw the individual drill pipes onto the threads of the drill pipe at the end of the drill string. Preferably, said rotating mechanism comprises support rollers pressed against the outer surface of the drill pipe and a motor for rotating the support rollers.

In another preferred embodiment of the drilling unit according to the invention, said support arm has at least one guide on which the rotating mechanism is suspended movably in the longitudinal direction of the guide, and the drill pipe handling device has displacement means for moving the rotating mechanism in the direction of the guides. The rotating mechanism can be made to move in the direction of the guides at a speed equaling the progress of the threads at the end of the drill pipe.

In another preferred embodiment of the drilling unit according to the invention, said displacement means comprises a threaded rod rotated by a motor in the rotating mechanism with an internally threaded sleeve attached to the support arm around the threaded rod. Preferably, the rotating mechanism comprises a transmission mechanism for transmitting the rotational movement of the support rollers to the threaded rod. The drill pipe supported by the support arm and the threaded rod included in the displacement means are thus rotated by the same motor.

In another preferred embodiment of the drilling unit according to the invention, said transmission mechanism comprises a first gear connected to the at least one support roller, a second gear arranged on the threaded rod, and a chain circling the first and second gears. The ratio of the rotational speeds of the support roller and the threaded rod can be changed by changing the sizes of the gears. By selecting suitable sizes for the gears, the rotational speed of the threaded rod and thereby the speed of motion of the rotating mechanism can be adjusted to be equal to the rising speed of the threads at the end of the drill pipe.

The invention has the advantage that it facilitates and speeds up the transfer of drill pipes from storage to the rotating unit and from the rotating unit back to storage, thus improving the performance and efficiency of the drilling unit.

In addition, the invention has the advantage that it improves the occupational safety and ergonomics of the operators of the drilling unit and reduces their workload.

An advantage of one embodiment of the invention is that it is simple and light in construction, resulting in savings in material and manufacturing costs.

Another advantage of one embodiment of the invention is that the drill pipe handling equipment is separate from the drilling machine boom, whereby it does not strain and load the drilling machine boom. In addition, the drilling machine fits in a significantly narrower space.

The invention is described in detail in the following, with reference to the accompanying drawings in which.

<FIG> shows, by way of example, a drilling unit according to the invention seen from the side, and <FIG> shows the same drilling unit seen from above. In the following, both images are described simultaneously.

The drilling unit has a frame <NUM> formed of metal pipe profiles with a vertical portion 10a and a horizontal portion 10b. The vertical portion is substantially at right angles to the horizontal portion. At the base of the vertical portion of the frame, there are plate-like metal brackets <NUM> through which an axle <NUM> transverse to the direction of the vertical portion passes. Alongside the vertical portion is a boom <NUM> having an upper surface <NUM> on the vertical portion side and a lower surface <NUM> on the opposite side thereof. The opposite side surfaces of the boom have rails <NUM> in the longitudinal direction of the boom. The boom is secured at its first end to the axle <NUM> so that the boom can rotate about the axle <NUM> to the vertical position shown in <FIG> or from the vertical position to a clockwise inclined position (<FIG>). During drilling, the boom can be in the vertical or in the inclined position. During transport of the drilling machine, the boom can be swinged around the axle to a transport position in the direction of the horizontal portion of the frame. In the transport position, the boom is at an angle of approximately <NUM> degrees to the horizontal.

Attached to the frame, there is a slide carriage <NUM> on which the rotating unit <NUM> of the drill pipes <NUM> is supported. The slide carriage is supported on the rails <NUM> on the side surfaces of the boom so that the slide carriage and the rotating unit supported thereon can move parallel to the boom <NUM> along the lower surface of the boom from a first end of the boom to a second end of the boom. At the first end of the boom there is a support <NUM> on which a pipe holder <NUM> is attached. The pipe holder has a hole for the passage of the drill pipe <NUM>. At the second end of the boom there is a pulley <NUM> around which a cable <NUM> unwinding from the spool of a hydraulic winch <NUM> is wound. The cable allows the rock sample to be lifted up from the drill hole.

On the other side of the vertical portion of the frame is a hydraulic pump <NUM>, which produces the hydraulic fluid pressure required by the hydraulically operated equipment of the drilling unit. The hydraulic pump is connected by hydraulic hoses to the hydraulically operated equipment of the drilling unit. For clarity, the hydraulic hoses are not shown in the figure. In connection with the hydraulic pump, there is a control panel <NUM> for controlling the operation of the drilling machine.

In addition to the drilling machine, the drilling unit includes a drill pipe handling device, by means of which the drill pipes are moved within reach of the rotating unit to be connected to the end of the uppermost drill pipe of the drill string to be drilled in the bedrock. Similarly, the drill pipes to be detached from the drill string lifted from the drill hole are moved away from the vicinity of the rotating equipment by the drill pipe handling device.

The drill pipe handling device has an elongate support arm <NUM> with a head end <NUM> and a tail end <NUM>. The support arm is attached at its first end, i.e. the first end of the head end <NUM>, to the axle <NUM>. The head end branches into two parts so that the first branch of the head end engages the first end of the axle on the first side of the boom <NUM>, and the second branch of the head end engages the second end of the axle on the second side of the boom. The second end of the head end is secured by a pivot pin <NUM> to the first end of the tail end <NUM> so that the tail end can rotate about the pivot pin. At the second end of the head end, there is a limiter <NUM> which sets an upper limit for the counterclockwise rotation of the tail end around the pivot pin. The horizontal portion of the frame has a support post <NUM> that supports the tail end of the support arm and prevents the support arm from rotating clockwise beyond the substantially horizontal first position shown in the figure.

At the first end of the tail end <NUM>, there is a plate-like projection <NUM>, to the tip of which is connected the first end of the hydraulic cylinder <NUM>. The second end of the hydraulic cylinder is connected to the vertical portion 10a of the frame so that with the tail end <NUM> in the first position parallel to the head end according to <FIG>, the hydraulic cylinder is in the extended position parallel to the head end above the support arm. The hydraulic cylinder is connected to the hydraulic pump <NUM> by hydraulic hoses (not shown).

Arranged at the tail end <NUM> of the support arm <NUM> is a drill pipe rotating mechanism comprising a first end support 46a and a second end support 46b connected to each other by support rods <NUM>. <FIG> shows only one support rod, but there may be several. There may be one or more intermediate supports between the first and second intermediate supports. These intermediate supports are similar in structure to the first end support. Above and below the tail end of the support arm there is a guide <NUM> in the direction of the tail end of the support arm. The guides are attached to the first end of the tail end <NUM> of the support arm by means of first end plates 47a, and to the second end of the tail end <NUM> by means of second end plates 47b. The first and second end supports and any intermediate supports are slidably attached to the guides so that the rotating mechanism can move on the guides parallel to them. To move the rotating mechanism, the mechanism has a threaded rod <NUM> attached rotatably about the longitudinal axis at its first end to the first end support and at its second end to the second end support. Between the first and second ends of the threaded rod there is an internally threaded sleeve <NUM> fixedly attached to the side of the tail end of the support arm. The threaded rod passes through the internally threaded sleeve so that rotation of the threaded rod causes the rotating mechanism to move along the guides towards the first end or the second end of the tail end of the support arm. The rotating mechanism further includes displacement rollers <NUM> which, when rotated, cause the drill pipe to move in the longitudinal direction of the support arm.

The drilling unit further includes a hydraulic cylinder for changing the position of the boom, a generator for generating electric power, a motor for generating the driving force of the hydraulic pump and generator, a drilling fluid pump and drilling fluid recirculation means. These devices are known devices commonly used in drilling units, and are not shown in the figure.

<FIG> show a part of the drilling unit shown in <FIG> and <FIG> in a cross-sectional view in the section plane A-A. The figures show the second end support 46a of the rotating mechanism belonging to the drill pipe handling device. In the following, both images are described simultaneously.

The second end support 46b has two parallel support plates <NUM> with a gap therebetween. There is a recess at the edge of the support plates, providing a space for the tail end <NUM> of the support arm. Between the edges of the recess and the walls of the support arm is a clearance, i.e. the wall of the support arm does not come into contact with the edge of the recess. The support plates have aligning upper holes above the tail end of the support arm and lower holes below the tail end. The guides <NUM> are arranged to pass through the upper and lower holes so that the upper and lower holes act as slide fastening members by means of which the second end support rests on the guides.

The gap between the support plates has two support rollers <NUM> through which a shaft pin <NUM> passes. The shaft pins rest on the first support plate at their first end and on the second support plate at their second end. The drill pipe <NUM> is rested on these two parallel support rollers, between the support rollers. Above the drill pipe is a press roller <NUM> which is attached to the end of a pivot arm <NUM> through a cylinder <NUM>. In <FIG>, the arm is turned to a first position, whereby the press roller is pressed against the wall of the drill pipe. In connection with the first support roller, there is a hydraulically operated motor (not shown), by means of which the first support roller and the drill pipe in contact with it are made to rotate about their central axis.

In <FIG>, the arm has been turned to a second position, whereby the press roller has risen up a distance along the surface of the drill pipe. The drill pipe then rests freely on the support rollers.

At the end of the shaft pin <NUM> of the second support roller there is a first gear <NUM> and at the end of the threaded rod <NUM> extending through the support plate there is a second gear <NUM>. A chain <NUM> encircles the first and second gears so that rotation of the support roller causes the threaded rod to rotate about a central axis, whereby the entire rotating mechanism moves on the guides <NUM> and parallel to the guides. The second support roller is made to rotate by rotating the drill pipe with the first support roller <NUM>, whereby the rotational movement of the drill pipe causes the second support roller to rotate. The first and second gears and the chain together form a transmission mechanism by means of which the rotational movement of the second support roller is transmitted to the threaded rod <NUM>. The rotational movement of the threaded rod is thus produced by the motor rotating the first support roller. The size of the first and second gears is selected to be such that, during one revolution of the drill pipe, the rotating mechanism moves by a distance equaling the thread pitch of the drill pipe. The gears are removably fastened in place, so that whenever the diameter of the drill pipe and the type of thread change, the gears can be changed to adjust the speed of rotation of the threaded rod.

<FIG> show the second end support 46b of the rotating mechanism. The first end support is similar in structure to the second end support, except that the first end support does not have a transmission mechanism for transmitting the rotational movement of the rotating rollers to the threaded rod. If there are intermediate supports between the first and second end supports, they are substantially similar in structure to the first end support.

<FIG> and <FIG> show a side view of the drilling unit shown in <FIG>. The figures illustrate the operation of the drill pipe handling device included in the drilling unit. In the following, both images are described simultaneously.

As the drill string rotated by the rotating unit <NUM> is drilled into the bedrock, the rotating unit moves along the boom <NUM> towards the pipe holder <NUM>. At the same time, the upper end of the drill string moves downward. During drilling, a drill pipe <NUM> is moved onto the support arm of the drill string handling device. The drill pipe can be moved to the handling device by hand or using an automatic manipulator.

When the end of the drill string is sufficiently low, the drill pipe supported on the drill pipe handling device is added to the drill string and attached to the upper end of the uppermost drill pipe in the drill string. This is carried out by shortening the length of the hydraulic cylinder <NUM>, whereby the tail end <NUM> of the support arm <NUM> rotates around the pivot pin <NUM> against the limiter <NUM> to the intermediate position shown in <FIG>. In the intermediate position, the tail end of the support arm forms an obtuse angle with the head end <NUM> of the support arm.

As the hydraulic cylinder is further shortened, the entire support arm begins to rotate about the axle <NUM>. The limiter prevents the angle between the head end <NUM> and tail end <NUM> of the support arm from changing as the support arm in its entirety rotates around the axle <NUM>. The hydraulic cylinder is shortened until the support arm rotates to the second position shown in <FIG>, where the tail end <NUM> of the support arm is substantially parallel to the boom <NUM>. In the second position, the imaginary center line of the drill pipe <NUM> supported by the rotating mechanism attached to the support arm is parallel and aligned with the center line of the uppermost drill pipe in the drill string passing through the rotating unit <NUM>. The drill pipe supported by the support arm is connected to the end of the uppermost drill pipe in the drill string by rotating the drill pipe with the rotating mechanism, whereby the rotating mechanism and the drill pipe supported by it move towards the upper end of the drill string. When the drill pipe hits the end of the drill string, it becomes attached to the threads of the uppermost drill pipe in the drill string. Naturally, drilling is temporarily suspended during the connection of the new drill pipe. Once the drill pipe is connected to the drill string, the support arm is first returned to the intermediate position of <FIG> by extending the hydraulic cylinder and further to the first position of <FIG> where it is ready to receive the next drill pipe.

The removal of drill pipes disconnected from the drill string lifted up takes place in the reverse manner.

<FIG> shows, by way of example, a drilling unit according to the invention seen from the side. The drilling unit shown in the figure is similar to the drilling unit shown in <FIG>, <FIG> and <FIG>. The drilling machine of the drilling unit can drill drill pipes <NUM> into the bedrock in either a vertical or oblique position. When drilling in an oblique position, the boom <NUM> of the drilling machine is placed at a desired angle to the vertical line and drilling is performed as described above.

The boom of the drilling machine shown in <FIG> is clearly in an oblique position. In the drilling unit according to the invention, the feeding of the drill pipes to the rotating unit <NUM> moving along the boom in an oblique position takes place in the same way as described above. The oblique position of the boom does not in any way hamper the operation of the drill pipe handling device, and the oblique position of the boom does not have to be specially taken into account when operating the handling device. Since the support arm <NUM> of the drill pipe handling device and the boom rotate about the same axle <NUM>, the tail end <NUM> of the support arm in the second position is always in a position parallel to the boom, regardless of the angle of inclination of the boom.

The drilling machine shown in the figures has a frame comprising a vertical portion and a horizontal portion. The drilling unit can be mounted on a vehicle body or platform, in which case it does not necessarily need to have a horizontal portion of the frame.

Some preferred embodiments of the drilling unit according to the invention have been described above. The invention is according to the features specified in the appended claims.

Claim 1:
A drilling unit, comprising a drilling machine, the drilling machine having a frame (<NUM>), a boom (<NUM>) attached to the frame (<NUM>) pivotally about an axle (<NUM>), and a rotating unit (<NUM>) for rotating a drill pipe (<NUM>), the rotating unit (<NUM>) being attached to the boom (<NUM>) so that it is movable in the longitudinal direction of the boom (<NUM>), characterized in that the rotating unit (<NUM>) is below the boom (<NUM>) when the boom is in an oblique drilling position the drilling unit further comprising a drill pipe (<NUM>) handling device with an elongate support arm (<NUM>) with a head end (<NUM>) and a tail end (<NUM>) for supporting a drill pipe (<NUM>), the first end of the head end (<NUM>) of the support arm (<NUM>) being attached to said axle (<NUM>) to rotate about the axle (<NUM>) along a trajectory in one plane.