WO2012060743A1

WO2012060743A1 - Arrangement for stabilising a vehicle carrying a rock drilling rig

Info

Publication number: WO2012060743A1
Application number: PCT/SE2010/000265
Authority: WO
Inventors: Alexander Liebert; Bo-Göran JOHANSSON
Original assignee: Atlas Copco Rock Drills AB
Current assignee: Epiroc Rock Drills AB
Priority date: 2010-11-01
Filing date: 2010-11-01
Publication date: 2012-05-10
Anticipated expiration: 2013-05-01
Also published as: SE1350638A1

Abstract

A rock drilling rig with four individual propulsion units and individual means for the height adjustment relative to the chassis of the vehicle for each one of the four propulsion units, and in the same way individual means for changing the distance between two propulsion units on the same side of the vehicle.

Description

Arrangement for stabilising a vehicle carrying a rock drilling rig

Display at an internationally recognised world exhibition

A solid scale model of a rock drilling rig, without any moving parts, and designed according to Figures 4A, 4B and 4C in this international patent application was displayed by the applicant at the world exhibition EXPO 2010, in Shanghai, China. This world exhibition took place between 1 May 2010 and 31 October 2010, and was one—Of the exhibitions recognised and registered by the Bureau International des Expositions, Paris. The model was displayed through a transparent cover.

Technical field

The present invention relates to the field of vehicular rock drilling rigs.

Background Rock drilling rigs of the type considered here have traditionally comprised a vehicle with four wheels, two on each side, or a track drive on each side of the vehicle. The vehicle also has a boom, mounted to the vehicle in a jointed manner, for directing a feed beam, which is normally fixed to the boom in a jointed manner. It is possible for a rock drill, attached to the rock drilling rig, to be displaced along this feed beam during a drilling operation in which the drill rods, with the drill bit at the front end, progressively descend into the rock. When the drill rods have been substantially fed into the rock, the rock drill is detached from the drill rods and transferred to the rearmost position of the feed beam before splicing in of a new drill rod between the drill and the drill rods that have just been detached from it can take place. A number of drill rods connected in this manner is known as a "drill string" and is used when holes that are deeper than the length of a drill rod are to be drilled.

A rock drilling rig comprises further means for directing, means for positioning and means for feeding a rock drill against processed rock and further means for the control and monitoring of the processing process. Furthermore, means for the propulsion and control of the vehicle itself can be included. All of these means may comprise a computer and/or a computer program that is to run on a computer included in the rock drilling rig.

In order to achieve efficient drilling, the drill is fed against the rock with great force while it subjects the drill rods/drill string to impact and rotational motion. This creates stability problems during the actual drilling operation, since the force from the drill string through the drill and the boom tends to tip the drilling rig. This limits not only the maximum force of feed that can be used, but also the maximum distance from the vehicle at which the holes can be drilled, since the boom becomes a lever arm that reinforces the tipping effect.

It is, furthermore, also the case that not only the standing location of the rock drilling rig before and during the drilling operation, but also the road that leads to this location are often very uneven. Rock slabs with a large gradient and loose stone blocks can severely hinder not only transport but also the positioning of a rock drilling rig. Even the rock drilling rigs themselves can cause stability problems since a fully extended boom, with its associated feed beam and rock drill with its connected drill steel and, where appropriate, magazine for drill rods, can cause tipping during motion before the drill steel obtains support from the ground.

A further problem may arise if the ground is soft, or if the rock has been weakened by cracks following the most recent blasting operation. This can cause sinking and the rig becoming impeded, and in extreme cases a risk of landslides, if the surface is exposed to forces that are too large.

The aim of the invention and its most important characteristics

One aim of the present invention is to provide An embodiment of a rock drilling rig to increase its stability against the risk of tipping. A further aim is to increase comfort for the operator in a rock drilling rig with an operator on board during transport and/or drilling. Furthermore, the invention also concerns increasing accessibility for a rock drilling rig on soft and disturbed

surfaces.

A rock drilling rig according to the invention comprises a vehicle with at least four propulsion units, two on each side of the vehicle. Furthermore, a boom connected to the vehicle in a jointed manner is included, for directing a feed beam, which is fixed in a jointed manner to the boom and arranged to support a rock drill that can be connected to it. In order to achieve the aims of the invention, a rock drilling rig according to the invention is characterised in that it comprises means to increase by means of a propulsion unit the stability of the rock drilling rig with respect to tipping and to improve the possibility of the propulsion unit making contact with the ground.

The propulsion units may be either of wheel type or track type. A propulsion unit of wheel type may have one or several wheels. In this case, more than one wheel is used primarily in order to reduce the pressure on the ground.

This means of increased stability by means of a propulsion unit and improved contact with the ground will be henceforth referred to using the term "means for stability and contact".

It is advantageous that this means for stability and contact comprise means for adjusting the height of the propulsion unit relative to a chassis in the vehicle, and means for changing the distance to a second propulsion unit on the same side of the vehicle.

It is further advantageous that at least two of the propulsion units of the vehicle are of the same type, i.e. either wheel type or track type .

It is also advantageous that there be four propulsion units, each comprising its own means for stability and contact.

One advantageous embodiment has individual means for the height adjustment relative to the chassis of the vehicle for each one of the four propulsion units, and in the same way individual means for changing the distance to a second propulsion unit on the same side of the vehicle. It is advantageous that there are at least four propulsion units of the same type, i.e. either wheel type or track type.

It is further advantageous that at least four propulsion units are of track type. It is furthermore advantageous that the tracks of the propulsion units of track type are made of flexible material, such as rubber or similar material. This contributes to good propulsion on soft surfaces without having a large influence on the surface.

It may be advantageous for obtaining a longer lifetime that the tracks of the propulsion units of track type are made of steel, rather than being made of flexible material.

Furthermore, it is advantageous that the rock drilling rig comprises two booms with associated feed beam.

It is advantageous that the two booms are fixed to the vehicle such that they can be set at an angle in the sideways direction.

It is further advantageous that each boom can be set at an angle in the sideways direction which is greater than 45 degrees relative to the longitudinal direction of the vehicle.

It is further advantageous that the booms can be set at an angle in the sideways direction which is greater than 60 degrees relative to the longitudinal direction of the vehicle.

It is advantageous that the means for stability and contact comprise an arm that is fixed in a jointed manner to the chassis of the vehicle, and that forms a connector between the chassis of the vehicle and a propulsion unit. It is further advantageous that the means for stability and contact also comprise the jointed attachment of this arm to a propulsion unit of track type or wheel type with more than one wheel, if at least two wheels are located one after the other along the

longitudinal direction of the rock drilling rig.

The motion around such a jointed attachment between an arm and a propulsion unit will be denoted as "oscillation" . Oscillation is also well-known from traditional rock drilling rigs using tracked operation. A concept that is analogous to oscillation and that is sometimes used in this context is "swinging". The oscillation is often of the order of magnitude +/- 10 degrees. "Floating

oscillation" is a well-known concept and it describes the automatic adaptation, through hydraulic control, of the contact between the tracks and the surface. Such floating oscillation is advantageous individually and independently for each one of the propulsion units according to the invention.

The invention allows a much greater degree of oscillation in that propulsion units of track type, or applicable forms of wheel type, have a much shorter length extension than corresponding traditional solutions. It is possible to achieve oscillation of +/- 90 degrees relative to the horizontal plane. This gives not only the

possibility of passing very steep gradients while maintaining a high fraction of ground contact but it also gives the advantage of obtaining further contributions to the height regulation of each propulsion unit, in addition to the height regulation that takes place through raising and lowering the arm that joins the propulsion unit with the chassis in the embodiments according to the figures. It is advantageous to regulate the height of the propulsion unit as a function of the vertical force on the drive shaft and/or the torque on the drive shaft. An increasing vertical force on the drive shaft can be assumed to indicate that another propulsion unit is in the process of losing contact with the ground. The propulsion unit whose drive shaft then has the lowest vertical force can thus be driven downwards until the vertical forces on the drive shafts have been substantially equalised. In the same way, a decreasing vertical force on a drive shaft can lead directly to downwards driving of the corresponding propulsion unit.

When the means for stability and contact is constituted by an arm jointed at the chassis and a fixture of the propulsion unit jointed at the arm, the regulation can take place in a first stage by setting the angles of the arm. In a second stage, to be used only when the first stage as described in the paragraph above has been exploited to a freely chosen limit, the height regulation continues with the aid of oscillation of the propulsion unit, i.e. rotation of the propulsion unit around the attachment with the arm. The freely chosen limit referred to in the preceding paragraph may be constituted by a pre-programmable limit for each drilling rig or by a limit that is influenced by the operator, in which factors such as the weight of the currently mounted equipment and the position of the boom during transport determine the extent to which the arms can be set at an angle, taking into account the stability. An arm that has been angled downwards to achieve better contact with the ground means that the distance between propulsion units is shorter, and thus that the stability is worse.

The regulation of height can take place as a function of the torque on the drive shaft of the propulsion unit instead of, or in

combination with, the regulation described above that takes place as a function of the vertical force. In an analogous way to the previous reasoning, a high required torque for the driving of the drive shaft of the propulsion unit can indicate that a second propulsion unit is losing contact with the ground. The regulation then takes place as described above. Similarly, a low driving torque on a drive shaft indicates that contact with the ground has been lost for the propulsion unit connected to the shaft. Also in this case regulation takes place as described above.

Another way of regulating is to regulate the height of a propulsion unit as a function of the orientation of the rock drilling rig in the horizontal plane. The drilling rig may comprise a gyroscope in order to measure this orientation.

Other alternative embodiments of the means for stability and contact may be used. Separate hydraulic cylinders may, for example, be used as height adjustment means and as means for adjusting the distance to the neighbouring propulsion unit. It will thereby be possible to regulate the two parameters independently of each other.

It is furthermore possible to give priority to stability and thus primarily control contact with the ground through the oscillation of propulsion units, rather than using the arm. It is also advantageous that it be possible to individually adjust the speed of each propulsion unit relative to the surface. It is furthermore advantageous if oscillation and arm movement are synchronised so that contact with the ground is maintained at at least two points for a propulsion unit when passing an obstacle, for example, by the track, in the case of tracked operation, retaining its previous position at one end while the opposite end is regulated for passage of obstacles.

Two booms with a large horizontal angle of rotation lead to the booms each compensating for the force of the other when placed in contact with the ground. This makes it possible to use larger feed forces and also to drill with a large force at a greater distance from the centre of the drilling rig without problems of stability becoming too large.

Brief description of the drawings

Figure 1 shows a rock drilling rig according to the prior art, with tracked operation.

Figure 2 shows an example of a rock drilling rig according to the invention with four independent propulsion units of tracked type. The rock drilling rig has a boom and a feed beam surrounded by a cover that muffles sound. Figure 3 shows a part of a rock drilling rig with propulsion units of wheel type. The rig is shown schematically, and is shown without a boom or operator cabin.

Figure 4 shows a rock drilling rig as shown in Figure 2, but in this case with two booms and seen directly from the front in 4a,

obliquely from the front in 4b, and obliquely from the back in 4c. Figures 5a and 5b show the oscillation function, in particular with retained contact with the ground at an existing level at one end of the track, when the second end is angled in order to pass an obstacle. This is achieved through synchronisation of the

oscillation and the movement of the arm.

Detailed description of preferred embodiments

A number of exemplifying embodiments of the invention are

described below. The invention is not limited to any of the embodiments described but it is defined by the claims. A rock drilling rig 100, 200 comprises a vehicle 180, 280 and at least four propulsion units 130, 230 together with at least one boom 110 that is connected to the vehicle in a manner that allows rotation. The ability to rotate may either be in the horizontal direction or in the vertical direction. A feed beam 120 is connected to the boom 110, preferably in a manner that allows angular positioning. The whole feed beam may be

surrounded by a cover 140 to muffle sound. The propulsion

units 130, 230 are connected to the vehicle through an arm

150, 250. This arm is connected to a chassis of the vehicle such that it can be rotated around a shaft 160, 260. Through the rotation of the arm 150, 250 around the shaft 160, 260, both the height of the propulsion unit relative to the chassis and its distance to another propulsion unit on the same side of the vehicle 180, 280 are influenced. Thus, the greatest

distance between two propulsion units on the same side of the vehicle, and thus the greatest stability, is achieved when the height of the vehicle is lowest. Propulsion units may be either of track type 130 or wheel type 230. Propulsion units of wheel type may have more than one wheel in order to increase the area of contact with the ground. If two such wheels in a propulsion unit are located one after the other along the longitudinal direction of the vehicle, such a propulsion unit may, similarly to a propulsion unit of track type 130, oscillate around a shaft 170 in order to maintain the best contact with the ground, even when the gradient of the ground is locally very steep. It is advantageous if this oscillation can be +/- 90 degrees.

In one preferred embodiment of the invention, the vehicle is equipped with four propulsion units of track type 130. All are, in relation to the other propulsion units individually controllable in the height and longitudinal direction. This makes it possible to achieve high stability with respect to tipping for the vehicle in different terrains and with different vehicular loads. Furthermore, it is possible to oscillate each one of the propulsion units independently of the others. This gives good contact with the ground in difficult terrain. Figures 2, 4B and 4C make it clear how the different propulsion units all occupy different heights and different oscillatory locations.

It can be advantageous to regulate the height of each propulsion unit as a function of the vertical force on, for example, the rotation shaft 170 of the unit. Decreasing force will lead to the propulsion unit being regulated downwards towards better contact with the ground, and vice versa. A corresponding regulation may take place as a function of the propulsion torque of the track. Decreasing torque will lead to control downwards for the propulsion unit. Alternatively, the horizontal plane of the vehicle may control the height of feed units, through a gyroscope installed in the vehicle. Force sensors, torque sensors or gyroscopes are in this case connected to a control computer on the vehicle, which computer controls units that set the oscillation or the change of angle of the arm 150, 250 around the shaft 160, 260. Calculation algorithms may be provided in the control computer in order to synchronise the oscillation with the angular control of the arm 150, so that one end of the track maintains its position relative to the surface when the oscillation function is activated in order to pass an obstacle such as a stone block, as is shown in Figures 5A and 5B. These

calculation algorithms may involve direct geometrical

calculation of corresponding positions for the angular position of the arm and the angle of oscillation.

Alternatively, tables may be present stored in the memory of the control computer from which synchronised angular settings are retrieved.

In order to gain higher stability, it is possible to have separate displacement of the distance between shafts of the propulsion units, for example in order to increase the separation of the shafts to increase stability, independently of height adjustments as a result of uneven terrain. The arm 150, 250, may for example, be replaced by a horizontal or vertical chute that is controlled either electrically, or preferably hydraulically .

It is further advantageous that the rock drilling rig comprise two booms with the associated feed beams. These will then absorb forces generated by the weight of the other boom' s weight or feed forces during drilling. These booms can be set at an angle in the horizontal plane that lies between 45 and 60 degrees relative to the body of the vehicle.

Claims

1. A rock drilling rig comprising a vehicle with at least four

propulsion units, two on each side of the vehicle, and further comprising a boom, connected to the vehicle in a jointed manner for the directional positioning of a feed beam attached to the boom in a jointed manner and arranged to support a connectable rock drill, said rock drilling rig being characterised in that it comprises means to via propulsion unit increase the stability of the rock drilling rig with respect to tipping, and to improve the possibility of the propulsion unit contacting the ground, said means to be henceforth referred to as "means for stability and contact" .

2. The rock drilling rig according to claim 1, whereby the means for stability and contact comprises means for adjusting the height of the propulsion unit relative to a chassis in the vehicle, and means for changing the distance to a second propulsion unit on the same side of the vehicle.

3. The rock drilling rig according to claim 1 or claim 2, whereby at least two of the propulsion units of the vehicle are either of wheel type or of track type.

4. The rock drilling rig according to any one of the preceding

claims, whereby each one of four propulsion units comprises its own means for stability and contact.

5. The rock drilling rig according to any one of the preceding

claims, further comprising a second boom with its associated feed beam.

6. The rock drilling rig according to any one of the preceding claims, where at least one boom is horizontally rotatable to an angle greater than 45 degrees relative to the longitudinal direction of the vehicle.

7. The rock drilling rig according to the preceding claims, where at least one boom is horizontally rotatable to an angle greater than 60 degrees relative to the longitudinal direction of the vehicle.

8. The rock drilling rig according to any one of the preceding

claims, where the height of a propulsion unit is regulated as a function of the vertical force on the drive shaft.

9. The rock drilling rig according to any one of the preceding

claims, where the height of a propulsion unit is regulated as a function of the torque on the drive shaft.