A method and an arrangement for controlling a rock drilling apparatus

The invention relates to a method for controlling the impact performance of a beater of a hydraulically operated rock drilling machine, in which method pressure fluid is simultaneously supplied to the beater and by a pressure reducing element of a feed device and wherein the impact power is controlled by regulating the pressure of the pressure fluid flowing to the beater.

Furthermore, the invention relates to an arrangement for controlling the impact performance of a hydraulically operated rock drilling machine, which arrangement a hydraulic fluid pump, a striker and a feed device, whose inlet channel is connected to a pressure channel of the pump, and at least one pressure reducing element between the pressure channel of the pump and the feed device, by the pressure of the feed device to be supplied to the pressure fluid lower than the pressure in the pressure channel of the pump is controllable

In known rock drilling machines, the impact pressure is fixed to a specific value, and whose feed is controlled by regulating the pressure of the feed mechanism according to the kind of stone to be drilled. If the feed pressure is too small compared to the impact pressure, wherein the feed rate is less than the required or allowed feed rate, a shock pulse is poorly transmitted via a boring bar on the stone to be drilled and causes vibrations on the boring bar and also on the other devices. The vibration is gradually converted into heat, with the largest temperature increase takes place at threaded connections of the drill rods or the like, which are thus particularly exposed to unnecessary stress. It follows that the drills are damaged or At the same time, the rate of penetration of a drill into the rock becomes smaller, and the time to drill a particular hole length becomes longer, thus increasing the cost of drilling. The shock also exposes all other mechanical and hydraulic components of the drills to extra stress and over time creates unnecessary need for maintenance and repair.

From AT-PS 359 451 a rock drilling machine is known which has a plurality of pumps. In each case a pump supplies pressure fluid to the drive motor, the impact drive and the feed circuit of the drill. The pumps are conventional pumps without regulators, and each pump is connected to a pressure line equipped with various adjustable restrictors and pressure regulators. These hold each of the pressure fluid flowing to the drive assemblies and their pressure at a desired level. The pressure of the pressure side of the feed motor throttles more or less the pressure fluid flow supplied to the drive motor and the impact drive, depending on how the pressure rises or falls.

The present invention has for its object to provide a method and an arrangement for controlling the bore of a rock drilling machine, by means of which the above-mentioned difficulties avoided weden and the bore can be performed as well as possible depending on the circumstances. The method according to the invention is characterized that pressure fluid is supplied with a pressure-controlled volume flow pump, in that the volume flow of the pump is controlled by a pressure between the feed device and the pressure reducing element and that the ratio of the pressures of the pressure fluids to be guided to the impactor and advancing means is controlled substantially constant by means of a pressure regulating element connected in series with the advancing means.

In this way, the ratio between the impact pressure and the feed pressure can be kept substantially constant, that the beater pressure is controlled in proportion to the feed pressure, the power of a beating pulse directly according to the presupposed by the feed pressure level and by applying a pressure-controlled volume control pump for supplying Pressure fluid is regulated. Here, the flow rate of this pump is controlled based on the feed pressure, and changes in the feed pressure, when the impact power is proportional to the volume flow flowing to the impact mechanism, cause similar changes in the impact pressure and keep the impact pressure and thus the impact power proportional to the feed pressure.

The arrangement according to the invention is characterized that the pump is a pressure-controlled volume control pump, in that a control pressure channel of the pump is connected to the inlet channel of the feed device between the pressure reducing element and the feed device and that at least one pressure regulating element is connected in series with the inlet channel of the feed device, by means of which the pressure of the pressure fluid to be guided to the striker in a substantially constant ratio to the pressure acting in the inlet channel of the feed device is durable.

The essential idea of ​​the arrangement according to the invention is that the inlet channel of the feed motor is connected to the control pressure channel of the pressure-controlled volume control pump, wherein the flow rate of the pump is controlled on the basis of the feed pressure of the feed motor, and that it has a pressure control element, the ratio between the impact pressure and keeps the feed pressure substantially constant.

The invention will be explained in more detail in the attached drawings. 1 shows schematically a coupling design according to the invention, and FIG. 2 shows schematically a second coupling design according to the invention.

-2AT396962B

Fig. 1 shows one of a non-shown and known to her known engine operated flow control pump (1) with a flow control cylinder (2) and a spring-loaded counter-cylinder (3).

Furthermore, a pressure-controlled, proportional control valve (4) is mounted on the pump. The pump (1) serves to suck pressure fluid from a pressure fluid container (5) and to supply it further to a pressure channel (6). To the pressure channel (6) a beating device (7) is connected, whose function and construction are generally known per se and will not be explained in more detail in this context. The pressure fluid returning from the impactor (7) is returned to the pressure fluid reservoir (5) through a return passage (8). The pressure channel (6) of the pump (1) is further coupled by a throttle (9) with a proportional valve (10) from which the hydraulic fluid is forwarded to a feed device (11), which is usually a feed motor, but also any other Feed device, such as a hydraulic cylinder or the like may be. The pressure fluid flowing out of the feed motor (11) is again directed through the return channel (8) into the pressure fluid container (5). Between the throttle (9) and the proportional valve (10), the pressure of the pressure fluid channel along a control channel (12) through a second throttle (13) to a proportional pressure relief valve (14) and further out to the pressure-controlled, proportional Regelvenitl (4) On one side of the proportional pressure relief valve (14), the hydraulic fluid is passed through the return channel (8) in the pressure fluid container (5).

When the motor, not shown, drives the pump (1), pressure is generated in the pressure channel (6) of the pump (1), whereby the fluid pressure fluid actuates the beater (7) and the feed motor (11) advances the drill in a known manner , If the conditions remain constant all the time, the pressure in the control channel (12) also remains constant and thus the function of the pump (I) is not controlled from the outside. In this case, the flow control cylinder (2) and the spring-loaded counter cylinder (3), which normally belong to the pump (1), the volume flow of the pump (1) automatically so that the pressure of the pressure channel (6) remains constant. The structure and function of the pump (1) and these components integral with the pump are generally well known in the art and therefore will not be discussed in detail here.

Under continued constant conditions, the pressure fluid flows through the first throttle (9) out of the pressure channel (6), wherein at the throttle (9), a pressure loss occurs. Next, the pressure fluid flows through the proportional valve (10) to the feed motor (11), wherein in the proportional valve (10) a predetermined pressure loss is independent of the flow and thus the feed motor (11) there is a pressure to the common pressure loss of the throttle ( 9) and the proportional valve (10) is smaller than the pressure in the pressure channel (6) and on the impact device (7). The pressure of the impactor (7) is controlled by means of the proportional pressure relief valve (14) which adjusts the highest pressure prevailing in the duct (12). By controlling the pressure limiting valve (14), the pressure in the channel (12) can be changed and in a corresponding manner the volume flow of the pump (1) and thus the pressure in the pressure channel (6) and on the beater (7) can be increased or decreased. The regulator of the pressure relief valve (14) and the regulator of the proportional valve (10) are coupled together so that with increasing control value of the pressure relief valve, that is, when the value of the maximum pressure in the control channel (12) grows, the control value of the proportional valve (10) correspondingly smaller is, with over flowing pressure fluid, a smaller pressure loss occurs and the feed pressure of the feed motor (11) is greater. The control of the valves is dimensioned so that the pressures of the feed motor (11) and the impactor (7) are in linear relationship to each other, that is, that their ratio is substantially constant.

For example, when a drill bit encounters a soft rock or cavity, a fracture, or the like during drilling, the force resisting the feed, and thus the pressure of the feed motor (II), will drop as follows: the pressure between the proportional valve (10) and the throttle (9) decreases. Because the throttle (9) prevents a rapid flow of the pressure fluid to the feed motor and thus a rapid advancing the advance of the feed motor (11), a pressure reduction brings with it, that the pressure of the control channel (12) decreases accordingly and the control valve (4 ) quickly reduces the volume flow of the pump (1). At decreasing volume flow at the same time the pressure in the pressure channel (6) decreases correspondingly and thus the impact pressure of the impact device (7) drops rapidly with decreasing feed pressure. It is thus not possible that an overfeed too high impact performance is produced and is converted into heat. When the drill bit again hits a rock or normal conditions, the pressure on the inlet side of the feed motor (11) and correspondingly the pressure between the proportional valve (10) and the throttle (9) increases again until it reaches the pressure value on the Pressure relief valve (14) is regulated. With increasing pressure between the valve (10) and the throttle (9), the pressure in the control channel (12) increases accordingly and regulates by means of the control valve (4), the flow rate of the pump (1) larger, until it is on the originally of the regulated pressure set level presupposed.

Figure 2 shows schematically another embodiment of the invention in which the impact pressure to a certain upper limit is not limited, but the impact and the feed are coupled together so that under a predetermined pressure ratio, an increase in pressure of the feed motor the pressure

The figure also shows a control valve (15) of the beater, by means of which it can be put into and out of operation and a control valve (16) of the feed motor, by means of which the Drilling machine can be moved forward or backward or stopped completely. The function and structure of these valves are known per se and are therefore not explained in detail. In this embodiment, only the proportional pressure difference control valve (10) is used to maintain a pressure difference proportional to the feed pressure between the impact pressure and the feed pressure. In this solution causes a change in the feed pressure, when the control valves (15) and (16) are in normal operating position, a change in the volume flow in the pump (1) in a manner corresponding to the solution of Figure 1 such that the pressure in the pressure channel (6) the pump (1) and thus at the striker (7) remains in a certain ratio to the feed pressure of the feed motor. In the solution of Figure 2, the ratio between the impact pressure and the feed pressure can be controlled by changing the control value of the proportional pressure difference valve (10). If, on the other hand, the impact pressure level to be used is to be controlled, it must be carried out so that the bias of the spring of the control valve (4) of the volumetric flow controller of the pump is regulated.

The Eifindung is not limited to the described embodiments. The invention may also be used in various ways to use variable volume pumps and various couplings to identify the pressures and connect the control pressure to the volume flow controlled pump. In the figures and in the description, generally speaking, various control and regulating valves as well as pressure relief valves or the like have not been cited by means of which the application of the arrangement can be controlled and protected in another way because they are not essential to the invention. Of course, the solution according to the invention can also be different, such. B. for controlling the drill arm and the components of a drill, used to keep the motion ratios of certain movements proportional to each other.