JP6906208B2 - Hydraulic rock drill, damper hydraulic circuit for that, and damper pressure control method - Google Patents

Description

The present invention relates to a hydraulic rock drill, a damper hydraulic circuit for that purpose, and a damper pressure control method.

Traditionally, hydraulic rock drills are often used for crushing or drilling rocks and the like. Various structures and types of hydraulic rock drills have been proposed.

Patent Document 1 discloses a hydraulic rock drill including a hydraulic striking device, a rotating device, and a feeding device. A drilling rod is connected to a shank rod attached to the tip of the main body, the shank rod is hit by a piston provided in a cylinder void, and a lock bit attached to the tip of the drilling rod is used to punch the shank rod. During drilling, the drilling rod is rotated by a rotating device provided in the main body, and a hole having a predetermined depth is drilled while the drilling machine is advanced by the feeding device. Since the target rock is not homogeneous, the rock drill operator adjusts the magnitude and strength of impact and rotation, thrust, etc. while observing the rock quality and rock condition.

Patent Document 2 discloses a hydraulic rock machine in which the energy of hitting a shank rod with a piston is transmitted to a bit via the rod, and the bit hits and crushes the bedrock.

According to this hydraulic rock machine, the reflected energy from the rock when hitting the rock is transmitted from the bit to the rock machine body via the rod and shank rod, and the rock machine body is temporarily retracted by this reflected energy. The main body of the rock drill advances by the crushing length of one blow by the thrust of the feeding device, and the next hit is performed there. By repeating this process, drilling work is performed.

The hydraulic drilling machine is provided with a hydraulic damper (buffer mechanism) in order to buffer the reflected energy and improve the impact transmission efficiency.

In Reference 2, a pressure control means using an electromagnetic proportional control valve is provided for adjusting the hydraulic pressure (damper pressure) supplied to the damper. The pressure control means performs arithmetic processing so that the damper pressure has a predetermined relationship with the feed pressure based on the pressure sensor that detects the feed pressure that sends the rock drill body forward and the electric detection signal from the pressure sensor. Equipped with an arithmetic processing device, an electromagnetic proportional control valve that controls the hydraulic pressure to the pressure reducing valve based on an electric signal from the arithmetic processing device, and a pressure reducing valve that reduces the pump pressure to the damper pressure based on the hydraulic pressure from the electromagnetic proportional control valve. ing.

Japanese Unexamined Patent Publication No. 11-173063 Japanese Unexamined Patent Publication No. 2001-341083

In a hydraulic rock drill as described above, the rock drilling efficiency changes greatly depending on the degree of buffering action by the damper, so it is necessary to adjust the damper pressure properly.

According to the pressure control means proposed in Reference 2, the electric detection signal of the feed pressure detected by the pressure sensor is sent to the arithmetic processing device. The arithmetic processing device performs a pressure calculation so that the damper pressure has a predetermined relationship with the feed pressure based on the electric detection signal, and sends the electric signal which is the calculation result to the electromagnetic proportional control valve. The electromagnetic proportional control valve controls the oil pressure to the pressure reducing valve based on the electric signal from the arithmetic processing device, and the pressure reducing valve adjusts the pump pressure to the damper pressure having a predetermined relationship based on the oil pressure from the electromagnetic proportional control valve. Reduce the pressure. In this way, the damper pressure is controlled.

However, in a conventional device such as Reference 2, the pressure sensor temporarily converts the oil pressure into an electric signal to perform arithmetic processing, and based on the arithmetic result, an electromagnetic proportional control valve is used to perform electric-hydraulic conversion to perform damper pressure. Because it controls, its configuration is complicated, it is not easy to adjust and maintain, and it must be done by a technician who has both hydraulic and electrical technology. In particular, the electromagnetic proportional control valve has a delicate operation and is vulnerable to impacts, etc., and has a relatively high probability of failure, so care must be taken in handling.

The present invention controls the damper pressure with a simple configuration using only hydraulic equipment, which is relatively easy to obtain, without performing electro-hydraulic conversion, and adjusts and maintains the hydraulic rock drill to operate efficiently. The purpose is to facilitate.

The device according to the present invention includes a propulsion mechanism that pushes a rotating tool toward an object by flood control to propel it, a striking mechanism that strikes the tool toward the object, and a striking mechanism that strikes the tool from the object. In a hydraulic rock drill having a damper mechanism that buffers the impact due to the reflection of the above by hydraulic pressure and a damper hydraulic circuit that supplies hydraulic pressure to the damper mechanism, the damper hydraulic circuit has a damper input port connected to a hydraulic source and a damper input port. A damper output port that outputs oil pressure to the damper mechanism, a flow rate adjusting valve provided between the damper input port and the damper output port, and an input port are connected to the output port side of the flow rate adjusting valve. A pilot-operated relief valve having a direct-acting relief valve, an input port connected to the output port side of the direct-acting relief valve, and an output port connected to the side of a return port connected to a tank, and the above-mentioned The pilot port of the pilot-operated relief valve has a pilot pipeline connected to supply the oil supply to the propulsion mechanism.

The damper hydraulic circuit according to the present invention includes a propulsion mechanism that hydraulically pushes a rotating tool toward an object to propel it, a striking mechanism that strikes the tool toward the object, and the object by striking the tool. It is a damper hydraulic circuit used in a hydraulic rock drill having a damper mechanism that buffers the impact due to reflection from an object by hydraulic pressure, and supplies hydraulic pressure to the damper mechanism, and is a damper input port connected to a hydraulic source. The damper output port that outputs the oil pressure to the damper mechanism, the flow rate adjusting valve provided between the damper input port and the damper output port, and the input port are connected to the output port side of the flow rate adjusting valve. A pilot-operated relief valve with an input port connected to the output port side of the direct-acting relief valve and an output port connected to the return port connected to the tank. , A pilot pipeline connected to the pilot port of the pilot-operated relief valve so that the oil supply supplied to the propulsion mechanism is supplied.

According to the present invention, it is possible to control the damper pressure with a simple configuration using only hydraulic equipment, which is relatively easy to obtain, without performing electric-hydraulic conversion, and to operate the hydraulic rock drill efficiently. Easy to adjust and maintain.

It is a figure which shows the schematic structure of the hydraulic rock drilling machine which concerns on this invention. It is sectional drawing which shows the schematic structure of the drill head of the hydraulic rock drill of FIG. It is sectional drawing which shows the damper mechanism of the drill head of FIG. 2 enlarged. It is sectional drawing which shows the damper mechanism of the drill head of FIG. 2 enlarged. It is a figure which shows the hydraulic circuit of a hydraulic rock drill. It is a figure which shows another example of a feed hydraulic circuit. It is a figure which shows the example of the relationship between a feed pressure Pp, a differential pressure Pα, and a damper pressure. It is sectional drawing which shows the example of the structure of the pilot operation type relief valve used for a damper hydraulic circuit. It is sectional drawing which shows the example of the structure of the linear motion type relief valve used for a damper hydraulic circuit. It is a figure which shows the example of the equipment structure of the feed hydraulic circuit shown in FIG. 6A. It is a figure which shows the example of the equipment structure of the feed hydraulic circuit shown in FIG. 6B.

The hydraulic rock drill 1 of the present embodiment includes a propulsion mechanism that pushes a rotating tool toward an object by flood control to propel it, a striking mechanism that strikes the tool toward the object, and an object by striking the tool. It has a damper mechanism that cushions the impact caused by reflection from the vehicle by hydraulic pressure, a damper hydraulic circuit that supplies hydraulic pressure to the damper mechanism, and the like. The details will be described below.

FIG. 1 shows a schematic configuration of the hydraulic rock drilling machine 1 according to the present invention, and FIG. 2 shows a schematic structure of a drill head 16 of the hydraulic rock drilling machine 1 of FIG.

In FIG. 1, the hydraulic rock drilling machine 1 rotates and drives the frame 11, the sprockets 12a and 12b rotatably attached to both ends of the frame 11, the chains 13 and the sprockets 12a spanned over the sprockets 12a and 12b. It has a hydraulic motor 14 for use, a carriage 15 connected to a chain 13 and linearly moving along a frame 11, a drill head 16 attached to the carriage 15, and the like. These are examples of the configuration of the feed mechanism (propulsion mechanism) FK that propels the drill head 16.

A drill rod (shank rod) 18 extends from the tip of the drill head 16. The drill rod 18 is rotatably and slidably supported at its tip by a centlyzer 19 provided on the frame 11. The drill rod 18 is rotationally driven by a hydraulic motor provided in the drill head 16, and is hit by a striking mechanism built in the drill head 16 to move with the movement of the drill head 16 and to move at the tip of the drill rod 18. The bit 20 which is a tool provided in the above crushes and drills a bedrock or the like which is an object.

FIG. 2 shows the schematic structure of the drill head 16 of the hydraulic rock drill 1 of FIG. 1, and FIGS. 3 and 4 show the damper mechanism PK of the drill head 16 of FIG. 2 in an enlarged manner. .. In FIG. 3, the damper piston 33 is located at the forward end, and in FIG. 4, the damper piston 33 is located at the intermediate position.

In FIG. 2, the drill head 16 includes a striking mechanism DK including a housing 31, a striking piston 32, a damper mechanism PK including a damper piston 33, a bushing 34, a gear 35, a gear 36, a spline 37, a hydraulic motor 17, and the like. It has a rotation drive mechanism KK.

A shank rod 18a protrudes slidably in the axial direction from the tip end side of the housing 31. The shank rod 18a is connected to the drill rod 18 and transmits a striking force and a rotational force. In the rotary drive mechanism KK, the shank rod 18a is rotated by a hydraulic motor 17 for rotational drive via gears 35 and 36 and a spline 37. Driven. The spline 37 and the shank rod 18a are connected in the rotational direction via a key, and these rotate integrally, and the shank rod 18a slides in the axial direction by a predetermined distance (for example, about 25 mm). Is possible.

The striking piston 32 has a piston portion 321 at the center and rod portions 322 and 323 on both sides thereof, and is slidable in the axial direction in the piston chamber 311 provided in the housing 31. Although not shown, a known striking mechanism DK is used around the striking piston 32 to periodically reciprocate the striking piston 32 in the forward and reverse directions, that is, in the direction of the arrow M1 to strike the shank rod 18a. Is provided. An example of the striking mechanism DK is the hydraulic mechanism described in Japanese Patent Application Laid-Open No. 11-173063. A damper mechanism PK configured around the damper piston 33 is provided at the boundary between the striking piston 32 and the shank rod 18a.

In the hydraulic rock drill 1, the drill head 16 reciprocates via the carriage 15 due to the traveling of the chain 13 by the rotation of the hydraulic motor 14 of the feed mechanism FK. When the drill head 16 moves forward, that is, is fed for drilling, the drill rod 18 advances while rotating, and at this time, a forward impact is applied by the impact mechanism DK. As a result, the bedrock and the like are crushed by the bit 20.

In FIGS. 3 and 4, the damper piston 33 has a large diameter portion 331 sliding in the large diameter chamber 42 provided in the housing 31, a land portion 332 sliding in the medium diameter chamber 43, and a small diameter chamber 44. It has a sliding small diameter portion 333.

Further, the housing 31 is provided with a hole 46 communicating with the medium-diameter chamber 43, a hole 47 communicating with the large-diameter chamber 42, and a hole 48 communicating with the large-diameter chamber 42. The holes 46 and 47 are supplied with oil from the damper output port PD1 of the damper hydraulic circuit YK4 described later, and the holes 48 are connected to the tank T. That is, the hole 48 is a drain port.

The chambers 42 and 44 are connected to the tank T via the drain passage.

A balance piston type valve V11 may be inserted between the damper output port PD1 and the hole 46 as shown in the figure. The balance piston type valve V11 shown in the figure operates in the same manner as a check valve that has a free flow in the direction from the damper output port PD1 toward the hole 46, but the effective areas at both ends of the spool for switching the opening and closing are different from each other. Therefore, the balance piston type valve V11 opens when the pressure in the medium-diameter chamber 43 communicating with the hole 46 drops.

When oil is supplied from the damper output port PD1, the damper piston 33 is pushed to the left in the figure by the hydraulic pressure of the large diameter chamber 42 and the medium diameter chamber 43, and this pressing pressure is pushed to the left side of the figure through the bushing 34. It acts as a force to push the 18a (that is, the drill rod 18) forward.

When the damper piston 33 is in a no-load state, that is, when the damper piston 33 is at the forward end as shown in FIG. 3, the hydraulic pressure acts only on the medium diameter chamber (first hydraulic chamber) 43. At this time, since the large diameter chamber (second hydraulic chamber) 42 is connected to the tank T via the hole 48, the pressure drops and the shank rod 18a is pushed forward in a substantially non-pressure state. The force is proportional to the pressure acting on the medium diameter chamber (first hydraulic chamber) 43.

When the drill head 16 is fed, the shank rod 18a retracts with respect to the housing 31 accordingly. As a result, the shank rod 18a pushes the damper piston 33 via the bushing 34, and the damper piston 33 retracts. When the damper piston 33 retracts, the hole 48 is closed and closed by the large diameter portion 331, and the medium diameter chamber 43 is sealed, the pressure rises, and the pressure increases. As the pressure of the medium diameter chamber 43 increases, the balance piston type valve V11 switches to the closed state. At this time, the force for pushing the shank rod 18a forward is the total force due to the pressure acting on the medium diameter chamber (first hydraulic chamber) 43 and the large diameter chamber (second hydraulic chamber) 42. ..

When the medium-diameter chamber 43 is sealed, the pressure decreases due to leakage, but when the pressure drops to a predetermined pressure, the balance piston type valve V11 switches to the open state, and oil is supplied to the medium-diameter chamber 43. NS.

FIG. 5 shows the hydraulic circuit YK of the hydraulic rock drill 1.

In FIG. 5, the hydraulic circuit YK is for the feed hydraulic circuit YK1 for the feed mechanism FK, the rotary hydraulic circuit YK2 for the rotary drive mechanism KK, the striking hydraulic circuit YK3 for the striking mechanism DK, and the damper mechanism PK. It has a damper hydraulic circuit YK4.

A hydraulic source of predetermined pressures P1 to P4 is supplied to each of the hydraulic circuits YK1 to YK4. These hydraulic sources may be referred to as "hydraulic source P1", "hydraulic source P2", or the like. These hydraulic sources P1 to P4 may be provided independently, but they can also be shared as described later.

The feed hydraulic circuit YK1 has a switching valve V1 and a relief valve 61. When the switching valve V1 which is a control valve is switched by a control circuit (not shown), the feed hydraulic motor 14 rotates forward, reverses, or stops, and the drill head 16 moves forward, backward, or stops. When oil is supplied to the forward port (propulsion port) PF1, it moves forward, and when hydraulic pressure is supplied to the backward port PF2, it moves backward. The pressure Pp of the forward port PF1 is adjusted by the relief valve 61. The pressure Pp of the forward port PF1 may be referred to as "feed pressure Pp".

The pressure Pp adjusted by the relief valve 61 can be easily adjusted by a hydraulic engineer or a person in charge at the site by manually rotating the handle or the adjusting screw of the relief valve 61. An appropriate pressure gauge may be attached to check the pressure.

The feed hydraulic circuit YK1 is an example of the "pressure regulator" in the present invention. The forward port PF1 is an example of the "propulsion port" of the present invention, and is the port of the hydraulic motor 14 on the side where the action of pushing the tool toward the object is generated by the rotation of the hydraulic motor 14.

The rotary hydraulic circuit YK2 has a switching valve V2 which is a control valve. When the switching valve V2 is switched, the rotary drive hydraulic motor 17 rotates forward, reverses, or stops, and the shank rod 18a rotates forward, reverses, or stops.

The striking hydraulic circuit YK3 has a switching valve V3 which is a control valve. By switching the switching valve V3, the hydraulic pressure to the striking mechanism DK is supplied or stopped. When the flood pressure is supplied, the striking mechanism DK is activated to periodically apply striking to the shank rod 18a.

The damper hydraulic circuit YK4 includes a damper input port DN1 connected to the hydraulic source P4 via a switching valve V4 which is a control valve, a damper output port PD1 that outputs hydraulic pressure to the damper mechanism PK, and a damper input port DN1 and a damper output. A flow control valve 51 provided between the port PD1 and a linear-acting relief valve 52 in which an input port 52P1 is connected to the output port 51P2 of the flow-regulating valve 51, and an output port of the direct-acting relief valve 52. Feed to the pilot-operated relief valve 53 and the pilot port 53P3 of the pilot-operated relief valve 53, to which the input port 53P1 is connected to the 52P2 side and the output port 53P2 is connected to the return port side connected to the tank T. It has a pilot line LP1 connected so that the oil supplied to the forward port PF1 of the hydraulic motor 14 for use is supplied.

The pressure (Pr + Pα) of the damper output port PD1 may be referred to as “damper pressure”.

The flow rate adjusting valve 51 adjusts the flow rate Q1 of the flood pressure flowing therethrough, and in the present embodiment, a pressure compensating type is used. Further, a check valve 54 that provides a free flow from the damper output port PD1 to the damper input port DN1 may be provided in parallel with the flow rate adjusting valve 51.

The direct acting relief valve 52 generates a differential pressure (set pressure) Pα between the input port 52P1 and the output port 52P2. The magnitude of the differential pressure Pα is, for example, about 2 to 4 MPa, preferably about 2.5 to 3.5 MPa, and the center value is, for example, about 3 MPa, which can be adjusted manually.

The pilot-operated relief valve 53 generates a pressure Pr corresponding to the pressure Pp applied to the pilot port 53P3 at the input port 53P1. The pilot port 53P3 is connected to the forward port PF1 of the hydraulic motor 14 via the pilot line LP1, so that the pressure of the forward port PF1 is applied to the pilot port 53P3 as the pressure Pp.

As a result, a pressure Pr which is substantially the same as the pressure Pp of the forward port PF1 is generated at the input port 53P1 of the pilot-operated relief valve 53.

At the input port 52P1 of the linear-acting relief valve 52, a pressure (Pr + Pα) obtained by adding a differential pressure Pα to the pressure Pr of the input port 53P1 of the pilot-operated relief valve 53 is generated, and this is output to the damper output port PD1. It is supplied to the damper mechanism PK.

The damper hydraulic circuit YK4 can be configured as one hydraulic circuit unit by attaching necessary hydraulic equipment to an appropriate housing or substrate and piping the damper hydraulic circuit YK4. Alternatively, those devices may be mounted adjacent to the tank provided in the hydraulic source P4. Alternatively, those devices may be placed in the vicinity of the drill head 16.

6 (A) and 6 (B) show another example of the feed hydraulic circuit YK1.

In FIG. 6A, the feed hydraulic circuit YK1B has a pilot-operated balancing valve 62 and a sequence valve 63 instead of the relief valve 61.

The pilot-operated balancing valve 62 is inserted into the pipeline from the hydraulic source P1 to the forward port (propulsion port) PF1. The input port of the sequence valve 63 is connected to the pilot port side of the pilot-operated balancing valve 62, the output port is connected to the tank side, and the pilot port is the forward port (propulsion port) of the hydraulic motor 14. It is connected to the backward port PF2, which is a port on the opposite side of the PF1.

When pressure is generated in the forward port PF1 to cause the hydraulic motor 14 to rotate in the normal direction and the drill head 16 moves forward, the pressure P1 is reduced by the pilot-operated balancing valve 62, and the pressure in the forward port PF1 is adjusted. The pressure adjustment by the pilot-operated balancing valve 62 is performed by adjusting the set pressure of the sequence valve 63 connected to the pilot port.

In this way, even when the pressure P1 is large, the pressure Pp required for driving the hydraulic motor 14 can be reduced by the pilot-operated balancing valve 62.

When pressure is generated in the retreat port PF2 and the hydraulic motor 14 reverses and the drill head 16 retreats, the pressure at the input port of the sequence valve 63 drops to near 0, which causes the pilot-operated balancing valve 62. The pressure between the input port and the output port drops (depressurizes) to near 0. As a result, the oil returning from the forward port PF1 flows into the tank T.

In the feed hydraulic circuit YK1B, the pressure on the output side (output port) of the pilot-operated balancing valve 62 (that is, the pressure of the forward port PF1) is the forward port (propulsion port) of the hydraulic motor 14 without providing the sequence valve 63. ) The pressure may be depressurized by the pressure of the retreat port PF2, which is the port on the opposite side of the PF1.

For example, a pilot check valve is connected instead of the sequence valve 63, and the pressure of the check valve PF2 opens the pilot check valve, and the pressure between the input port and the output port of the pilot-operated balancing valve 62 drops to around 0. You may try to do so. Further, a pilot check valve may be connected between the forward port PF1 and the tank T so that the pressure of the reverse port PF2 opens the pilot check valve and the pressure of the forward port PF1 drops to around 0.

In FIG. 6B, the feed hydraulic circuit YK1C has a pilot-operated pressure reducing valve 64 and a check valve 65 in place of the relief valve 61.

The pilot-operated pressure reducing valve 64 is inserted into the pipeline from the hydraulic source P1 to the forward port (propulsion port) PF1. The check valve 65 is connected in parallel with the pilot-operated pressure reducing valve 64 so as to have a free flow from the forward port PF1 toward the hydraulic source P1.

When a pressure is generated in the forward port PF1 to cause the hydraulic motor 14 to rotate forward and the drill head 16 moves forward, the pressure P1 is reduced by the pilot-operated pressure reducing valve 64, and the pressure in the forward port PF1 is adjusted. That is, even when the pressure P1 is large, the pressure can be reduced to the pressure Pp required for driving the hydraulic motor 14 by the pilot-operated pressure reducing valve 64.

When pressure is generated in the retreat port PF2, the hydraulic motor 14 reverses, and the drill head 16 retreats, the oil returning from the forward port PF1 flows into the tank T via the check valve 65.

When the feed hydraulic circuits YK1B and C are used, the pressure Pp is adjusted by the hydraulic engineer or the person in charge at the site by manually rotating the adjusting screw or the handle of the sequence valve 63 or the pilot-operated pressure reducing valve 64. It can be done easily.

Further, when the feed hydraulic circuits YK1B and C are used, the hydraulic source P1 of the feed mechanism FK and the hydraulic source P4 of the damper mechanism PK can be shared by a common single hydraulic source. That is, a single hydraulic pump can be used to generate flood pressure, which can be commonly used as the hydraulic sources P1 and P4.

Next, an example of setting the pressure in the hydraulic circuit YK shown in FIG. 5 will be described.

The pressure (feed pressure) Pp of the forward port PF1 of the hydraulic motor 14 in the feed mechanism FK is set to, for example, 5 MPa. At this time, the pressure (differential pressure) Pα of the linear acting relief valve 52 in the damper mechanism PK is set to 2.2 to 3.0 MPa, and the pressure of the damper output port PD1, that is, the damper pressure (Pr + Pα) is 7.2 to 7. Set to 8.0 MPa.

In this case, the flow rate Q1 in the flow rate adjusting valve 51 is set to, for example, 10 to 13 L / min.

Further, the pressure (feed pressure) Pp of the forward port PF1 is set to, for example, 8 MPa. At this time, the pressure (differential pressure) Pα of the linear motion relief valve 52 is set to 2.2 to 3.0 MPa, and the damper pressure (Pr + Pα) is set to 10.2 to 11.0 MPa.

FIG. 7 (A) shows the relationship between the change in the feed pressure Pp and the change in the differential pressure Pα and the flow rate Q1 with respect to the change, and FIG. 7 (B) shows the change in the feed pressure Pp and the damper pressure (Pr + Pα) with respect to the change. The relationship with each is shown.

FIG. 7A shows changes in the differential pressure Pα and the flow rate Q1 when the feed pressure Pp is set to 5 MPa, the differential pressure Pα is set to 3 MPa, and the flow rate Q1 is set to 12 L / min, respectively, and the feed pressure Pp is changed. It is an observation of.

As shown in FIG. 7A, the feed pressure Pp is in the range of 2 to 8 MPa, the differential pressure Pα is in the range of 3.4 to 2.8 MPa, and the flow rate Q1 is in the range of 15 to 7.5 L / min. be. Therefore, the damper pressure (Pr + Pα) supplied to the damper mechanism PK is always higher by 3.4 to 2.8 MPa of the differential pressure Pα with respect to the feed pressure Pp.

FIG. 7B shows the basic relationship between the change in feed pressure Pp and the damper pressure (Pr + Pα).

As shown in FIG. 7B, the damper pressure (Pr + Pα) increases in a predetermined range in proportion to the increase in the feed pressure Pp. As shown in FIG. 7A, the differential pressure Pα is not strictly constant, but the fluctuation is within a small predetermined range, and it can be said that the damper pressure (Pr + Pα) is substantially proportional to the feed pressure Pp.

More specifically, the differential pressure Pα tends to decrease slightly as the feed pressure Pp increases. Therefore, as shown in FIG. 7 (B) between the straight two-dot chain line and the solid line of the curve, the slope of the increase in the damper pressure (Pr + Pα) tends to decrease slightly as the feed pressure Pp increases. be.

This cause is caused by the characteristics of the relief valve because the pressure difference between the damper pressure (Pr + Pα) and the hydraulic source decreases and the flow rate Q1 decreases as the feed pressure Pp increases. These defects can be prevented by making the flow rate regulating valve a pressure compensating type.

In the hydraulic rock drill 1, the damper pressure (Pr + Pα) may not necessarily be exactly proportional to the feed pressure Pp, and may be used depending on the actual structure of the hydraulic rock drill 1 and the drill head 16. It is possible to make adjustments so that the optimum operation is achieved by selecting the device to be used.

In this way, by using the damper hydraulic circuit YK4, the damper pressure can always be set to a value larger than the feed pressure Pp by the differential pressure Pα. The damper hydraulic circuit YK4 is composed of a flow rate adjusting valve 51, a linear acting relief valve 52, and a pilot-operated relief valve 53, and uses only hydraulic equipment that is relatively easy to obtain without performing electric-hydraulic conversion. The damper pressure can be controlled with a simple configuration, and adjustment and maintenance for efficiently operating the hydraulic rock drill 1 can be facilitated.

By controlling the damper pressure, the movement of the shank rod 18a, that is, the drill rod 18 that tries to return by receiving the repulsive force from the bedrock or the like at the time of hitting can be effectively suppressed by the damper mechanism PK. As a result, the rock landing property of the bit 20 is ensured, and the energy of the shock wave can be reliably transmitted to the bedrock.

Next, a specific example of the equipment used for the hydraulic circuit YK will be described.

FIG. 8 shows a cross-sectional view of an example of the structure of the pilot-operated relief valve 53 used in the damper hydraulic circuit YK4.

In FIG. 8, the pilot-operated relief valve 53 is provided with a piston 72 for adjusting the main flow rate and a pilot valve 75 for adjusting the pressure inside the body 71.

The pressure oil entering from the input port 53P1 acts on the lower surface of the piston 72, and at the same time, enters the spring chamber 74a through the orifice 73a, and further acts on the needle valve 75 through the passages 73b and 73c. When the pressure acting on the needle valve 75 exceeds the set value of the spring 76, the needle valve 75 opens and the pressure oil in the spring chamber 74a flows out to the needle chamber 74b. When the pressure in the spring chamber 74a decreases due to this operation, the piston 72 rises and the flow path from the input port 53P1 to the output port 53P2 opens.

In this case, the set value of the spring 76 can be arbitrarily adjusted by rotating the adjusting screw 77.

The pressure oil that has flowed out to the needle chamber 74b can flow out to the output port 53P2 via the passage 73d.

In the present embodiment, the pilot pipeline LP1 is connected to the pilot port (vent port) 53P3. Therefore, by applying the pressure Pp to the pilot port 53P3 via the pilot pipeline LP1, the pressure of the spring chamber 74a becomes substantially equal to the pressure Pp, and the pressure of the input port 53P1 is maintained to be substantially equal to the pressure Pp. .. That is, the pressure of the input port 53P1 is remotely controlled by the pressure Pp of the pilot port 53P3 via the pilot pipeline LP1.

FIG. 9 shows a cross-sectional view of an example of the structure of the linear motion relief valve 52 used in the damper hydraulic circuit YK4.

In FIG. 9, the direct acting relief valve 52 is provided with a poppet valve 82, a spring 83, an adjusting screw 84, and the like inside the body 81.

The pressure oil entering from the input port 52P1 flows into the poppet chamber 85a and acts on the poppet valve 82. When the pressure acting on the poppet valve 82 exceeds the set value of the spring 83, the poppet valve 82 opens, and the pressure oil in the poppet chamber 85a flows into the spring chamber 85b and reaches the output port 52P2. When the pressure in the poppet chamber 85a is reduced by this operation, the poppet valve 82 is closed by the force of the spring 83. As a result, the pressure of the input port 52P1 is maintained at the set pressure. The set pressure can be arbitrarily adjusted by rotating the adjusting screw 84 with a screwdriver or the like.

FIG. 10 shows an example of the equipment configuration of the feed hydraulic circuit YK1B.

In FIG. 10, the pilot-operated balancing valve 62 is provided with a valve body 92, a spring 93, a needle valve 94, a spring 95, an adjusting handle 96, and the like inside the body 91.

The pressure oil entering from the input port 62P1 flows into the valve chamber 97a and acts on the valve body 92. When the pressure acting on the valve body 92 exceeds the set value of the spring 93, the valve body 92 opens, the valve chamber 97a communicates with the drain port 62PD, and the pressure oil flows out to the tank T. When the pressure in the valve chamber 97a is reduced by this operation, the valve body 92 is closed by the pressure of the spring 93 and the pilot port 62P3.

As a result, the pressure of the input port 62P1 is maintained at the set pressure, and the pressure Pp is output to the hydraulic motor 14 as the feed pressure of the forward port PF1 and at the same time, the pilot-operated relief valve 53 of the pilot-operated relief valve 53 passes through the pilot pipeline LP1. It is output to the pilot port 53P3.

The pressure Pp set by the pilot-operated balancing valve 62 can be easily unloaded by setting the pressure of the sequence valve 63.

FIG. 11 shows an example of the equipment configuration of the feed hydraulic circuit YK1C.

In FIG. 11, the pilot-operated pressure reducing valve 64 is provided with a valve body 102, a spring 103, a needle valve 104, a spring 105, an adjusting handle 106, a check valve body 107, and the like inside the body 101.

The pressure oil entering from the input port 64P1 reaches the output port 64P2, enters the spring chamber 108b via the passage 109a and the orifice 109b, reaches the needle chamber 108c, and acts on the needle valve 104. When the pressure acting on the needle valve 104 exceeds the set value of the spring 105, the needle valve 104 opens and the pressure oil flows out to the tank T through the drain hole 109c. As a result, the pressure of the spring chamber 108b becomes the set pressure set by the spring 105. The pressure of the output port 64P2 is maintained at a pressure corresponding to the set pressure set by the spring 105.

The pressure Pp of the output port 64P2 is output to the hydraulic motor 14 as the feed pressure of the forward port PF1 and is also output to the pilot port 53P3 of the pilot-operated relief valve 53 via the pilot pipeline LP1.

The set pressure of the spring 105, that is, the pressure Pp set by the pilot-operated pressure reducing valve 64 can be easily adjusted by the adjusting handle 106.

These devices are readily available on the market and can be easily assembled and used by those skilled in the art as hydraulic circuits YK.

In the above-described embodiment, the feed mechanism FK, the rotary drive mechanism KK, the striking mechanism DK, the damper mechanism PK, the feed hydraulic circuit YK1, the rotary hydraulic circuit YK2, the striking hydraulic circuit YK3, the damper hydraulic circuit YK4, the hydraulic circuit YK, and the drill. The configuration, structure, arrangement, number, material, combination, dimensions, pressure value, and the like of the head 16 and the hydraulic rock drill 1 as a whole or each part can be various other than those described above.

1 Hydraulic rock drill 14 Hydraulic motor 16 Drill head 17 Hydraulic motor 18 Drill rod (tool)
18a Shank rod (tool)
20 bits (tool)
32 Strike piston 33 Damper piston 51 Flow control valve 52 Direct acting relief valve 53 Piping operation type relief valve LP1 Piping pipeline DN1 Damper input port PD1 Damper output port P4 Hydraulic source V4 Switching valve Pα Differential pressure (set pressure)
Pp feed pressure Pr pressure (feed pressure)
(Pr + Pα) Damper pressure (pressure)
FK feed mechanism (propulsion mechanism)
KK Rotation drive mechanism DK Impact mechanism PK Damper mechanism YK Hydraulic circuit YK1 Feed hydraulic circuit YK2 Rotary hydraulic circuit YK3 Impact hydraulic circuit YK4 Damper hydraulic circuit

Claims (10)

A propulsion mechanism that pushes a rotating tool toward an object by flood control to propel it, a striking mechanism that hits the tool toward the object, and a striking mechanism that hits the tool to cause an impact due to reflection from the object by flood control. In a hydraulic rock drill having a damper mechanism for buffering and a damper hydraulic circuit for supplying flood control to the damper mechanism.
The damper hydraulic circuit
The damper input port connected to the hydraulic source and
A damper output port that outputs hydraulic pressure to the damper mechanism,
A flow rate adjusting valve provided between the damper input port and the damper output port,
A linear relief valve with an input port connected to the output port side of the flow control valve,
A pilot-operated relief valve with an input port connected to the output port side of the linear-acting relief valve and an output port connected to the return port side connected to the tank.
A pilot pipeline connected to the pilot port of the pilot-operated relief valve so that the oil supply supplied to the propulsion mechanism is supplied, and
A hydraulic rock drill characterized by having. The pressure Pr of the input port of the pilot-operated relief valve corresponds to the hydraulic pressure Pp supplied to the pilot port.
A pressure (Pr + Pα) obtained by adding the set pressure Pα of the linear motion relief valve to the pressure Pr is output to the damper output port.
The hydraulic rock drill according to claim 1. The flow rate adjusting valve is a pressure-compensated flow rate adjusting valve.
The hydraulic rock drill according to claim 1 or 2. The propulsion mechanism
A hydraulic motor for propulsion and
A pressure regulator connected to a propulsion port, which is a port of the hydraulic motor on the side where the action of pushing the tool toward an object is generated by the rotation of the hydraulic motor.
Is provided,
One end of the pilot line is connected to the side of the propulsion port.
The hydraulic rock drill according to any one of claims 1 to 3. The hydraulic source of the propulsion mechanism and the hydraulic source of the damper hydraulic circuit are shared by a common single hydraulic source.
As the pressure adjusting device
It has a pilot-operated balancing valve and
The pilot-operated balancing valve is inserted into a conduit from the hydraulic source to the propulsion port.
The pressure on the output side of the pilot-operated balancing valve is configured to be depressurized by the pressure on the port opposite to the propulsion port of the hydraulic motor.
The hydraulic rock drill according to claim 4. The hydraulic source of the propulsion mechanism and the hydraulic source of the damper hydraulic circuit are shared by a common single hydraulic source.
As the pressure adjusting device
It has a pilot-operated pressure reducing valve and a check valve.
The pilot-operated pressure reducing valve is inserted into a pipeline from the hydraulic source to the propulsion port.
The check valve is connected in parallel with the pilot-operated pressure reducing valve so as to have a free flow from the propulsion port toward the hydraulic source side.
The hydraulic rock drill according to claim 4. A propulsion mechanism that pushes a rotating tool toward an object by flood control to propel it, a striking mechanism that hits the tool toward the object, and a striking mechanism that hits the tool to cause an impact due to reflection from the object by flood control. A damper hydraulic circuit used in a hydraulic rock drill having a damper mechanism for buffering, and for supplying hydraulic pressure to the damper mechanism.
The damper input port connected to the hydraulic source and
A damper output port that outputs hydraulic pressure to the damper mechanism,
A flow rate adjusting valve provided between the damper input port and the damper output port,
A linear relief valve with an input port connected to the output port side of the flow control valve,
A pilot-operated relief valve with an input port connected to the output port side of the linear-acting relief valve and an output port connected to the return port side connected to the tank.
A pilot pipeline connected to the pilot port of the pilot-operated relief valve so that the oil supply supplied to the propulsion mechanism is supplied, and
A damper hydraulic circuit for a hydraulic rock drill, characterized by having. The pressure Pr of the input port of the pilot-operated relief valve corresponds to the hydraulic pressure Pp supplied to the pilot port.
A pressure (Pr + Pα) obtained by adding the set pressure Pα of the linear motion relief valve to the pressure Pr is output to the damper output port.
The damper hydraulic circuit for the hydraulic rock drill according to claim 7. The flow rate adjusting valve is a pressure-compensated flow rate adjusting valve.
The damper hydraulic circuit for the hydraulic rock drill according to claim 7 or 8. A propulsion mechanism that pushes a rotating tool toward an object by flood control to propel it, a striking mechanism that hits the tool toward the object, and a striking mechanism that hits the tool to cause an impact due to reflection from the object by flood control. A method of controlling the pressure of the flood control supplied to the damper mechanism in a hydraulic rock drill having a damper mechanism for buffering.
The damper input port connected to the hydraulic source and
A damper output port that outputs hydraulic pressure to the damper mechanism,
A flow rate adjusting valve provided between the damper input port and the damper output port,
A linear relief valve with an input port connected to the output port side of the flow control valve,
A pilot-operated relief valve with an input port connected to the output port side of the linear-acting relief valve and an output port connected to the return port side connected to the tank.
A pilot pipeline connected to the pilot port of the pilot-operated relief valve so that the oil supply supplied to the propulsion mechanism is supplied, and
Using a damper hydraulic circuit with
The pressure Pr of the input port of the pilot-operated relief valve is made to correspond to the pressure Pp of the hydraulic pressure supplied to the propulsion mechanism.
To the damper mechanism, the oil pressure (Pr + Pα) of the pressure (Pr + Pα) obtained by adding the set pressure Pα of the linear motion relief valve to the pressure Pr is output.
A method for controlling the pressure of a damper in a hydraulic rock drilling machine.

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