CN114000822B

CN114000822B - Impact mechanism of rock drill

Info

Publication number: CN114000822B
Application number: CN202111237673.5A
Authority: CN
Inventors: 胡艳芳; 田翔; 曾婷; 李小祥; 李珊; 席玮航; 王淞源; 曹星宇; 黄永
Original assignee: Jiangxi Wosd Rock Drilling Hydraulic Co ltd
Current assignee: Jiangxi Worth Rock Drilling Hydraulic Co ltd
Priority date: 2021-10-23
Filing date: 2021-10-23
Publication date: 2023-03-14
Anticipated expiration: 2041-10-23
Also published as: CN114000822A

Abstract

The application discloses impact mechanism of rock drill, including holding chamber and change oil circuit, the holding intracavity be provided with piston and switching-over valve, reciprocating motion is done along the piston axial in the holding intracavity to the piston to the oil circuit changes to the damping force of cooperation push valve post rear end, through the switching-over valve to the piston application of force. The driving cavity is connected with the high-pressure oil path through an oil inlet throttling valve, and the oil inlet throttling valve works to provide damping force for the push valve rod; the oil return branch is connected with oil return through an oil return throttling valve, and the oil return throttling valve works to supplement the action of the oil inlet throttling valve, so that the piston and the reversing valve kinematic pair continue to decelerate at low speed; the reversing valve is connected with the driving cavity through a valve pushing column, so that hydraulic pressure of the driving cavity acts on the reversing valve. The force applied to the piston by the reversing valve mainly changes the direction of the resultant force of the piston in the whole movement process, so that the reciprocating movement of the piston is ensured. The piston motion is more stable in this application, and life is longer.

Description

Impact mechanism of rock drill

Technical Field

The application relates to the field of rock drills, in particular to an impact mechanism of the rock drill.

Background

The impact mechanism is suitable for use in a variety of applications, such as drilling quarries, tunnels or mines. These machines are constituted by a load-bearing part, called a carriage, on which a guide rail is positioned, which receives a rotary percussion device of the drilling type. A rotary impact device generally consists of an impact mechanism and a rotation mechanism. The equipment mounted on the carrier receives hydraulic power and converts it into mechanical impact and rotational power, thereby forming a borehole due to the drill shank, drill rod or cutting edge in contact with the rock.

The percussion mechanism is usually rigidly assembled in the housing of the rotary percussion device, while the rotation mechanism, which comprises a motor mounted transversely on an axis parallel to the axis of the percussion mechanism, drives the drill shank of the drill rod in rotation via a reduction pinion. The drill shank is thus driven into rotational movement and receives the impact provided by the piston of the impact mechanism. The drawbacks of this conventional solution are: the cost of the equipment is high due to the presence of pinions, which are expensive components and the installation of the pinions in the device requires expensive mechanical means.

Chinese patent application "hydraulic rotary impact device for drilling", application (patent) No.: CN201010296161.1, discloses a housing comprising a forming support; a percussion mechanism comprising a longitudinal body, which body is rotatably mounted in a housing along an axis of the body, the percussion mechanism comprising a cylinder extending along the axis of the body, a percussion piston slidably mounted in the cylinder and adapted to strike a drill shank connected to a drill rod, and a distribution device arranged to control the reciprocating movement of the percussion piston along the axis of the body; and a motor arranged to drive the body of the impact mechanism to rotate along a rotation axis substantially coincident with the body axis. The impact mechanism comprises a closing cap mounted on the body and arranged for closing one of the ends of the body, said closing cap being connected in a rotary manner to the output shaft of the motor and comprising, at least in part, the dispensing means.

However, the above patent applications have the following problems: 1. because the motor is located the complete machine rear end, increased equipment length, the rock drill length is longer, and service environment is restricted. 2. The rock drill has numerous parts and is inconvenient to assemble, disassemble and maintain. 3. The impact mechanism and the rotating mechanism share the same parts, and the clearance fit is large, so that the coaxial fit of the whole size is not facilitated. 4. The oil circuit is complicated for its part processing degree of difficulty is higher, and then leads to product cost height.

Disclosure of Invention

An aim at of this application provides an impact mechanism of rock drill, reduces rock drill spare part quantity, and the dismouting is maintained simplyr.

Another object of the application is to provide an impact mechanism of a rock drill, which has less sudden change of oil pressure problems and more stable movement compared to a double-sided oil return type.

Another aim at of this application provides an impact mechanism of rock drill, and the oil circuit design is simpler, reduces the spare part processing degree of difficulty.

Another object of the present application is to provide an impact mechanism for rock drills which is more compact, overall smaller length and smaller volume.

The technical scheme adopted by the application is as follows: an impact mechanism for a rock drill comprising: the piston and the reversing valve are arranged in the accommodating cavity, the piston reciprocates along the axial direction of the piston in the accommodating cavity, one end of the variable oil path is connected with the reversing valve, the other end of the movable piston switching variable oil path is connected with the high-pressure oil path or the oil return path, and the variable oil path applies force to the piston through the reversing valve; the driving cavity is connected with the high-pressure oil way through the oil inlet throttling valve, the oil inlet throttling valve works to control whether the driving cavity is communicated with the high-pressure oil way, the reversing valve is partially connected with the driving cavity, and hydraulic pressure of the driving cavity acts on the reversing valve. The oil inlet throttle valve works to control the hydraulic internal damping force of the driving cavity and enable the piston and the reversing valve kinematic pair to decelerate.

Compared with the prior art, the reversing valve has the advantages that the reversing valve is connected with the high-pressure oil way or the oil return way in the moving process of the piston. The direction of resultant force received by the reversing valve is different by connecting with different oil ways. The reversing valve and the piston are also positioned in the accommodating cavity, and the piston can be contacted with the reversing valve in the movement process. And forces in different directions are applied to the piston through hydraulic pressure in the reversing valve, and the forces applied to the piston by the reversing valve mainly enable the movement speed of the piston to be controllable in the whole movement process and enable the piston to reciprocate. Particularly, in the return motion after the piston is collided, the piston can move in a deceleration way by the matching of the reversing valve and the throttle valve, and the piston is prevented from colliding the accommodating cavity. The piston motion is more stable in this application, and life is longer.

This application goes to be connected with the switching-over valve through setting up the drive chamber, and the hydraulic pressure in the drive chamber can act on the switching-over valve naturally. The drive chamber can assist and change the oil circuit and come to act on the switching-over valve, and then fluid passes through the switching-over valve and to the piston application of force. In this application, the drive chamber is connected with high-pressure oil circuit through the oil feed choke valve, that is to say that operating personnel is the damping force that can control piston switching-over valve motion pair and receive through the oil feed choke valve. To sum up, this application is through setting up drive chamber and oil feed choke valve, can control the application of force to the piston to realize the reciprocating motion of piston.

In some embodiments of this application, the drive intracavity install and push away the valve post, push away the valve post and act on the switching-over valve, push away the axial displacement that the valve post atress was then along the drive chamber, the locating part inner wall be provided with the inner groovy, the inner groovy not with push away the valve post contact, high-pressure oil circuit switches on from inner groovy department and drive chamber.

In the actual use in-process, if do not set up the inner groovy, then when pushing away the valve post and moving extreme position, push away the valve post promptly and contact with locating part internal wall face, the fluid of drive intracavity is pushed out by pushing away the valve post this moment, even high-pressure oil circuit and drive chamber switch on, its effort also is difficult for acting on and pushes away the valve post. This application sets up the inner groovy, and the inner groovy is kept away the sky with pushing away the valve post all the time, can have fluid promptly with the inner groovy that the high pressure oil circuit is connected, guarantees to push away the valve post and still has sufficient fluid to exist in pushing away the valve post rear side in extreme position department for the drive chamber can push up on the switching-over valve once more after letting in high-pressure oil.

In some embodiments of the present application, the wall surface of the accommodating cavity is provided with a plurality of pressure equalizing grooves, the pressure equalizing grooves are located on the periphery of the piston, and oil exists in the pressure equalizing grooves.

This application sets up a plurality of pressure-equalizing grooves, and in the piston motion process, it will be to the piston effect to be located pressure-equalizing inslot fluid, and the uneven distribution that reduces the impact mechanism of rock drill fluid and receive that the dead weight leads to the fact hydraulic clamping power to the piston, guarantees that piston motion is smooth and easy.

In some embodiments of the present application, the piston includes an impact surface for impact and a rear end surface remote from the impact surface, and the diverter valve is located on a side of the piston adjacent the rear end.

In some embodiments of the present application, the diverter valve includes a head face adjacent the piston and a tail face distal the piston.

In some embodiments of the present application, the variable oil path includes a first intersection and a second intersection which are disposed on the wall of the accommodating chamber, the first intersection is disposed on the outer peripheral side of the piston, and the second intersection is disposed on the end face of the reversing valve.

In some embodiments of the present application, the piston is provided with a first passage, and the first passage communicates the rear end surface of the piston with the outer peripheral surface of the piston. And when the piston moves to a preset position in the movement process of the piston, the first passage is communicated with the change oil way. Specifically, the first channel is communicated with the first intersection.

In some embodiments of the present application, the oil return path includes an oil return branch, the oil return branch is disposed on the wall of the accommodating chamber, and the oil return branch is located on the periphery of the piston.

In some embodiments of the present application, the piston is provided with a coupling groove on an outer circumferential surface thereof. And in the movement process of the piston, when the piston moves to a preset position, the connecting groove is communicated with the oil return branch and the change oil way. Specifically, the connecting groove is communicated with the oil return branch and the first intersection.

In some embodiments of the present application, the high-pressure oil passage includes a high-pressure oil port, the high-pressure oil port is disposed on the wall of the accommodating chamber, and the high-pressure oil port is located on the outer peripheral side of the reversing valve or the piston. The position of the high-pressure oil port is unchanged, but the piston and the reversing valve both carry out reciprocating motion, and the high-pressure oil port is positioned on the periphery of the reversing valve, or the periphery of the piston, or the periphery of the distance between the reversing valve and the piston. The piston and the reversing valve are not completely synchronous in the whole movement process, so that a space exists between the piston and the reversing valve in a period of time, and if the space is just positioned at the high-pressure oil port, oil of the high-pressure oil port enters the first channel along the space.

In some embodiments of the present application, the reversing valve is cylindrical in basic shape, and the area of the head end face of the reversing valve is smaller than the area of the tail end face of the reversing valve.

In some embodiments of the present application, a second passage is disposed in the direction change valve, and the second passage communicates the head end surface and the tail end surface of the direction change valve. And the second intersection is communicated with a second channel positioned at the tail end of the reversing valve.

In some embodiments of the present application, the stopper portion is located in the second channel. And when the reversing valve moves to be in contact with the limiting piece, the limiting piece reaches the limit position, and the limiting piece blocks the second channel. In this application, the locating part has still played the guide effect. When the second channel is blocked by the limiting piece, hydraulic pressure difference exists between the head end face and the tail end face of the reversing valve, and the reversing valve is pushed to move by the hydraulic pressure difference.

In some embodiments of the present application, the limiting member is provided with a step surface, and the reversing valve moves to contact with the step surface, so that the second channel is blocked.

Specifically, if the front end face of the limiting member is processed into a plane to be in contact with the reversing valve to block the second channel, it is necessary to ensure that two planes in contact with the reversing valve and the limiting member can be completely attached to each other.

This application sets up the preceding terminal surface of locating part into the ladder face, so add that the step top surface that ensures the ladder face and switching-over valve contact can laminate with the switching-over valve completely, just can realize blocking channel two completely. Therefore, the manufacturing cost of the application is lower, and the corresponding effect is better.

The high-pressure oil way comprises a first branch, the first branch is connected with the limiting part, and the first branch is communicated with the inner groove. And the oil inlet throttling valve controls the connection or disconnection of the first branch.

In some embodiments of the present application, the oil return path includes an oil return opening, the oil return opening is disposed on the wall of the accommodating cavity, and the oil return opening is located on the periphery of the reversing valve and near the tail end of the reversing valve. And in the reciprocating motion process of the reversing valve, the oil return port is communicated with the second channel or blocked by the reversing valve.

In some embodiments of the present application, the first branch is connected with an oil inlet throttle valve.

In some embodiments of the present application, an oil return throttle valve is disposed between the oil return branch and the oil return path.

The application includes return stroke motion and stroke motion in the whole working process, and for convenience of description, the direction of the reversing valve towards one side of the piston is taken as the front, and then the reversing valve is naturally located behind the piston.

Specifically, in the return movement: at the beginning of the return stroke, the directional valve is located at the foremost end of its stroke. At the moment, the high-pressure oil port is blocked by the reversing valve, the reversing valve is far away from the limiting piece, and the second channel conducts the head end face of the reversing valve and the tail end face of the reversing valve. And the oil return port is communicated with the second channel. A space exists between the piston and the reversing valve, and the space is communicated with the oil return path. The intersection two of the change oil path is communicated with the oil return port through a channel two, and the intersection one of the change oil path is communicated with the channel one.

The front end face of the reversing valve is communicated with the oil return path, the tail end face of the reversing valve is communicated with the oil return path, and the push valve post is communicated with the high-pressure oil path. The tail end face of the reversing valve head has hydraulic pressure difference, and the reversing valve is pushed to be located at the limit position of the front end of the stroke. The distance between the piston and the oil return path is communicated, the front cavity of the piston is constantly connected with a high-pressure oil path, and the piston is driven by hydraulic pressure difference to do accelerated motion backwards.

The piston moves backwards to be in contact with the reversing valve, and the piston can drive the reversing valve to continue moving backwards.

When the reversing valve moves backwards for a certain distance, the oil return port is blocked, and the variable oil way is disconnected with the first passage. The oil inlet throttling valve plays a role in providing damping force for the kinematic pair, after the kinematic pair moves to a certain position, the damping force of the oil inlet throttling valve is reduced due to the reduction of the speed, the oil return throttling valve plays a role in the system, and the damping force is further increased. The piston is in contact with the reversing valve, and no space exists between the piston and the reversing valve. At the moment, the piston and the reversing valve synchronously move backwards in a decelerating way.

The piston and the reversing valve move backwards together to the limit position at the rearmost end, at the moment, the speed of the piston and the reversing valve is reduced to be close to 0, and the return movement is completed. At this moment, the second channel is blocked by the limiting part, the connecting groove is communicated with the oil return branch and the first intersection, namely, the oil return path is communicated with the second channel by the change oil path.

The piston still keeps small kinetic energy when reaching the rearmost extreme position, because the weight of the piston is far greater than the weight of the reversing valve, the piston is separated from the reversing valve, the distance between the piston and the reversing valve is communicated with the high-pressure oil port, and high-pressure oil enters the rear end face of the piston. Because the area of the rear end surface of the piston is larger than the acting area of the front cavity of the piston, the piston moves forwards in an accelerated manner, and the piston moves into a stroke. The front end face of the reversing valve is communicated with high-pressure oil, and the oil pressure of the front end face of the reversing valve is greater than that of the tail end face of the reversing valve, so that the reversing valve is pressed at the rear end mechanical limiting position.

The piston continues to move forward, and the reversing valve is kept still until the change oil way is communicated with the first passage. High-pressure oil enters the rear cavity of the reversing valve through the first channel and the variable oil way. At the moment, the action area of high-pressure oil on the tail end face of the reversing valve is larger than that of the end face of the reversing valve head, so that the reversing valve moves forwards in an accelerated manner.

The piston continues to move forward. Meanwhile, the reversing valve moves forwards in an accelerated manner until the reversing valve closes the high-pressure oil port at the rear end of the piston. At the moment, the piston just generates collision movement, impact energy is transmitted to the drilling tool, and backward return movement of a new period is prepared to start; and then the reversing valve continues to move forwards to a front side mechanical limit to wait for the next return stroke stage to be in contact with the piston, so that one cycle of movement is completed.

Drawings

The present application will be described in further detail below with reference to the drawings and preferred embodiments, but those skilled in the art will appreciate that the drawings are only drawn for the purpose of illustrating the preferred embodiments and therefore should not be taken as limiting the scope of the present application. Furthermore, unless specifically stated otherwise, the drawings are merely schematic representations based on conceptual representations of elements or structures depicted and may contain exaggerated displays and are not necessarily drawn to scale.

FIG. 1 illustrates a first state of the return stroke motion of the present application;

FIG. 2 shows a second state of the return stroke motion of the present application;

FIG. 3 illustrates a second state of the return motion of the present application;

FIG. 4 shows a second state of the return stroke motion of the present application;

FIG. 5 illustrates a first state of the present application stroke movement;

FIG. 6 illustrates the second state of the present application in the stroke motion;

FIG. 7 shows state three of the present application stroke movement;

fig. 8 shows state four of the stroke motion of the present application.

Wherein the reference numerals are specified as follows: 1. an accommodating cavity; 2. a variable oil path; 2a, a first intersection; 2b, a second intersection; 3. a piston; 3a, an impact surface; 3b, a rear end face; 4. a diverter valve; 4a, a head end face; 4b, end surfaces; 5. a first channel; 6. a second channel; 7. a high-pressure oil path; 7a, a branch I; 8. an oil return path; 9. an oil return branch; 10. a high-pressure oil port; 11. an oil return port; 12. connecting grooves; 13. a limiting member; 14. pushing the valve stem; 15. an inner groove; 16. a pressure equalizing groove; 17. a drive chamber.

Detailed Description

The present application will now be described in detail with reference to the accompanying drawings.

In order to make the objects, technical solutions and advantages of the present application more clearly understood, the present application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.

The impact mechanism of the rock drill is shown in figures 1 to 8: including holding chamber 1, change oil circuit 2 and locating part 13 that has drive chamber 17, holding chamber 1 in be provided with piston 3 and switching-over valve 4, piston 3 is reciprocating motion along piston 3 axial in holding chamber 1, switching-over valve 4 be located piston 3 one side of keeping away from impact surface 3a, change oil circuit 2 one end and connect switching-over valve 4, the other end that the piston 3 that moves switches over change oil circuit 2 is connected with high-pressure oil circuit 7 or oil return circuit 8, change oil circuit 2 is through switching-over valve 4 application of force to piston 3. The direction of force received by the reversing valve 4 is different by connecting the reversing valve 4 with different oil paths. The reversing valve 4 and the piston 3 are positioned in the accommodating cavity 1, and the piston 3 can be contacted with the reversing valve 4 in the moving process. Forces in different directions are applied to the piston 3 through the reversing valve 4, and the force applied to the piston 3 by the reversing valve 4 mainly enables the moving speed of the piston 3 to be controlled in the whole moving process. Especially, in the return stroke movement after the piston 3 is collided, the reversing valve 4 is matched with the change oil path 2, the oil inlet throttle valve and the oil return throttle valve, so that the piston 3 can move in a speed reduction manner, and the piston 3 is prevented from colliding the accommodating cavity 1. The speed of the piston 3 and the reversing valve 4 is ensured to be close to 0 when the piston reaches the rear limit position smoothly. The piston 3 moves more stably in the application, and the service life is longer.

The driving cavity 17 is connected with the high-pressure oil path 7 through an oil inlet throttle valve, the oil inlet throttle valve provides damping force for the piston 3 and the reversing valve 4 kinematic pair, the reversing valve 4 is partially connected with the driving cavity 17 through a valve pushing column 14, and hydraulic pressure of the driving cavity 17 acts on the reversing valve 4.

This application is connected with switching-over valve 4 through setting up drive chamber 17, and the hydraulic pressure in drive chamber 17 can act on switching-over valve 4 naturally. The drive chamber 17 assists the variable oil path 2 to act on the directional valve 4 and thus to apply force to the piston 3 through the directional valve 4. In the present application, the driving chamber 17 is connected to the high-pressure oil path 7 through an oil-feeding throttle valve, that is, an operator can control the damping force provided by the driving chamber 17 through the oil-feeding throttle valve, so as to control the acting force of the driving chamber 17 on the reversing valve 4. To sum up, this application can control the application of force to piston 3 through setting up drive chamber 17 and oil feed choke valve to control piston 3's motion stroke, and then control impact energy and impact frequency.

The high-pressure oil way device is characterized in that a valve pushing column 14 is installed in the driving cavity 17, the valve pushing column 14 acts on the reversing valve 4, the valve pushing column 14 is stressed to move axially along the driving cavity 17, an inner groove 15 is formed in the inner wall of the limiting part 13, the inner groove 15 is not in contact with the valve pushing column 14, and the high-pressure oil way 7 is communicated with the driving cavity 17 from the inner groove 15.

In the actual use process, if the inner groove 15 is not provided, when the push spool 14 moves to the extreme position, that is, the push spool 14 contacts with the inner wall surface of the limiting member 13, at this time, the oil in the driving chamber 17 is pushed out by the push spool 14, and even if the high-pressure oil passage 7 is communicated with the driving chamber 17, the acting force is not easy to act on the push spool 14. This application sets up inner groovy 15, and inner groovy 15 keeps away the sky with push valve post 14 all the time, can have fluid in the inner groovy 15 of being connected with high-pressure oil circuit 7 promptly, guarantees that push valve post 14 still has sufficient fluid to exist in push valve post 14 rear side in extreme position department for driving chamber 17 can push up on switching-over valve 4 once more after letting in high-pressure oil.

The wall surface of the accommodating cavity 1 is provided with a plurality of pressure equalizing grooves 16, the pressure equalizing grooves 16 are positioned at the periphery of the piston 3, and oil liquid exists in the pressure equalizing grooves 16.

This application sets up a plurality of pressure-equalizing grooves 16, and in 3 motion processes of piston, be located 16 interior fluid of pressure-equalizing groove and will act on piston 3, reduce the uneven distribution that the interior fluid of the impact mechanism of rock drill received the dead weight to lead to and cause hydraulic pressure chucking power to piston 3, guarantee that piston 3 moves smoothly.

The piston 3 comprises an impact surface 3a for impact and a rear end surface 3b far away from the impact surface 3a, and the reversing valve 4 is positioned on one side of the piston 3 close to the rear end surface 3 b. The reversing valve 4 comprises a head end face 4a close to the piston 3 and a tail end face 4b far from the piston 3. The variable oil path 2 comprises a first intersection 2a and a second intersection 2b which are arranged on the wall of the accommodating cavity 1, the first intersection 2a is arranged on the outer peripheral side of the piston 3, and the second intersection 2b is arranged on the tail end face 4b of the reversing valve 4.

The piston 3 is provided with a first passage 5, and the first passage 5 is communicated with the rear end surface 3b of the piston 3 and the peripheral surface of the piston 3. When the piston 3 moves to a predetermined position during the movement of the piston 3, the first passage 5 communicates with the changing oil passage 2. Specifically, the first channel 5 is communicated with the first intersection 2a.

The oil return path 8 comprises an oil return branch 9, the oil return branch 9 is arranged on the wall of the accommodating cavity 1, and the oil return branch 9 is positioned on the periphery of the piston 3.

The outer circumferential surface of the piston 3 is provided with a connecting groove 12. When the piston 3 moves to a preset position in the movement process of the piston 3, the connecting groove 12 is communicated with the oil return branch 9 and the change oil path 2. Specifically, the connecting groove 12 connects the oil return branch 9 with the first intersection 2a.

The high-pressure oil way 7 comprises a high-pressure oil port 10, the high-pressure oil port 10 is arranged on the wall of the accommodating cavity 1, and the high-pressure oil port 10 is positioned on the outer peripheral side of the reversing valve 4 or the piston 3. The position of the high-pressure oil port 10 is unchanged, but the piston 3 and the reversing valve 4 both carry out reciprocating motion, and the high-pressure oil port 10 is positioned on the periphery of the reversing valve 4, the periphery of the piston 3 or the periphery of the distance between the reversing valve 4 and the piston 3. The whole movement process of the piston 3 and the reversing valve 4 is not completely synchronous, so that a space exists between the piston 3 and the reversing valve 4 in a period of time, and if the space is right at the high-pressure oil port 10, oil in the high-pressure oil port 10 enters the first passage 5 along the space.

The basic shape of the direction valve 4 is cylindrical, and the area of the head end face 4a of the direction valve 4 is smaller than the area of the tail end face 4b of the direction valve 4. A second channel 6 is arranged in the reversing valve 4, and the second channel 6 is communicated with the head end surface 4a and the tail end surface 4b of the reversing valve 4. And the second intersection 2b is communicated with a second channel 6 at the tail end of the reversing valve 4.

And a limiting piece 13 is fixedly arranged in the accommodating cavity 1, and the limiting piece 13 is positioned in the second channel 6. When the reversing valve 4 moves to contact with the limiting piece 13, the limiting piece 13 reaches the limit position, and the second channel 6 is blocked by the limiting piece 13. In the present application, the limiting member 13 also plays a guiding role. When the second channel 6 is blocked by the limiting member 13, a hydraulic pressure difference exists between the head end surface 4a and the tail end surface 4b of the reversing valve 4, and the reversing valve 4 is pushed to move by the hydraulic pressure difference.

The limiting piece 13 is provided with a step surface, and the reversing valve 4 moves to be in contact with the step surface, so that the second channel 6 is blocked.

Specifically, if the front end surface of the limiting member 13 is entirely processed into a plane to be in contact with the reversing valve 4 to block the second channel 6, it is necessary to ensure that the two planes in contact with the reversing valve 4 and the limiting member 13 can be completely attached to each other, and if the two planes have problems of protrusion, recess, and the like during processing, the blocking effect of the second channel 6 is not ideal, so that the requirements on the surface processing accuracy of the reversing valve 4 and the limiting member 13 are very high, and the manufacturing cost is too high.

The front end face of the limiting piece 13 is set to be a step face, so that the second channel 6 can be completely blocked as long as the step face contacting the reversing valve 4 can be completely attached to the step top face of the reversing valve 4 during machining. Therefore, the manufacturing cost is lower, and the corresponding effect is better.

The high-pressure oil circuit 7 comprises a first branch 7a, the first branch 7a is connected with the limiting piece 13, and specifically, the first branch 7a is communicated with the inner groove 15. And the oil inlet throttling valve controls the connection or disconnection of the branch I7 a.

The oil return path 8 comprises an oil return port 11, the oil return port 11 is arranged on the wall of the accommodating cavity 1, and the oil return port 11 is positioned on the periphery of the reversing valve 4 and close to the tail end of the reversing valve 4. During the reciprocating motion of the reversing valve 4, the oil return port 11 is either communicated with the second channel 6 or blocked by the reversing valve 4. And an oil return throttling valve is arranged between the oil return branch 9 and the oil return path 8.

The present application includes a return movement and a stroke movement in the whole working process, and for convenience of description, the direction of the direction valve 4 toward the piston 3 will be taken as the front direction, and then the direction valve 4 is naturally located behind the piston 3.

The front cavity of the containing cavity 1 is at a high pressure and the rear cavity is at an oil return state, the connection condition of oil in the front cavity and the rear cavity of the reversing valve 4 is changed through the movement of the piston 3, meanwhile, the reversing valve 4 changes the connection condition of the oil on the rear end surface 3b of the piston 3, the switching of the thrust of the rear end surface 3b of the piston 3 is realized, (the action area relationship is that the rear end surface 4b of the reversing valve 4 is larger than the head end surface 4a of the reversing valve 4 = the rear end surface 3b of the piston 3 is larger than the impact surface 3a of the piston 3, and the oil pressure relationship is that a high-pressure oil path 7 is larger than an oil return path 8, the pressure of the oil return path 8 is approximately equal to 0) and the switching of the oil pressure in the front cavity and the rear cavity of the reversing valve 4 are realized, so that the piston 3 and the reversing valve 4 alternately move back and forth, and finally, and the interaction of the piston 3 and the reversing valve 4 realizes the closed-loop control of the movement of the rock drill.

Specifically, in the return movement: as shown in fig. 1, at the beginning of the return stroke, the directional valve 4 is located at the foremost end of its stroke. At this time, the high-pressure oil port 10 is blocked by the reversing valve 4, the reversing valve 4 is far away from the limiting piece 13, and the second channel 6 conducts the head end face 4a and the tail end face 4b of the reversing valve 4. The oil return port 11 is communicated with the second channel 6. And a space exists between the piston 3 and the reversing valve 4, and the space is communicated with the oil return path 8. And a second intersection 2b of the change oil path 2 is communicated with the oil return port 11 through a second passage 6, and a first intersection 2a of the change oil path 2 is communicated with a first passage 5.

That is, the front end face of the reversing valve 4 is communicated with the oil return path 8, the rear end face 4b of the reversing valve 4 is communicated with the oil return path 8, and the push valve stem 14 is communicated with the high-pressure oil path 7. Hydraulic pressure difference exists between the head end surface and the tail end surface of the reversing valve 4, and the reversing valve 4 is pushed to be located at the limit position of the front end of the stroke. The distance between the rear ends of the pistons 3 is communicated with an oil return path 8, the front cavities of the pistons 3 are constantly connected with a high-pressure oil path 7, and the pistons 3 are driven by hydraulic pressure difference to do accelerated motion backwards.

As shown in fig. 2, the piston 3 moves backward to contact the direction valve 4, and the piston 3 drives the direction valve 4 to move backward.

As shown in fig. 3, when the change valve 4 moves backward for a certain distance, the oil return port 11 is blocked, and the change oil passage 2 is disconnected from the first passage 5. The push rod 14 receives a damping force under the action of the rear end inlet throttle valve. And when the piston 3 and the reversing valve 4 move to the oil return branch 9 to serve as the only oil return access, the oil return throttle valve is added to play a role in ensuring that the piston 3 and the reversing valve 4 continue to decelerate under the condition of speed reduction. The piston 3 is in contact with the diverter valve 4 without a space between them. At the moment, the piston 3 and the reversing valve 4 synchronously perform deceleration movement backwards under the action of two throttle valve damping forces.

As shown in fig. 4, the piston 3 moves backward together with the direction valve 4 to the rearmost limit position, at which time the speed of the piston 3 and the direction valve 4 is reduced to approximately 0, and the return movement is completed. At this time, the second passage 6 is blocked by the limiting element 13, and the connecting groove 12 communicates the oil return branch 9 with the first intersection 2a, that is, the oil return path 8 communicates with the second passage 6 by the variable oil path 2.

As shown in fig. 5, when the piston 3 reaches the rearmost end limit position, a small amount of kinetic energy is still retained, since the weight of the piston 3 is much greater than that of the directional valve 4, the piston 3 is separated from the directional valve 4, the space between the piston 3 and the directional valve 4 is communicated with the high-pressure oil port 10, and the rear end surface 3b of the piston 3 enters high-pressure oil. Because the area of the back end surface 3b of the piston 3 is larger than the acting area of the front cavity of the piston 3, the piston 3 moves forwards in an accelerated manner, and the piston enters into stroke motion. The front end face of the reversing valve 4 is communicated with high-pressure oil, and because the oil pressure of the front end face of the reversing valve 4 is greater than that of the oil pressure of the tail end face 4b of the reversing valve 4, the reversing valve 4 is pressed at the rear end mechanical limit position.

As shown in fig. 6 and 7, the piston 3 continues to move forward, and the direction change valve 4 remains stationary until the change oil passage 2 communicates with the passage one 5. High-pressure oil enters the rear cavity of the reversing valve 4 through the first channel 5 and the variable oil way 2. At this time, the acting area of the high-pressure oil on the rear end face 4b of the reversing valve 4 is larger than that of the head end face 4a of the reversing valve 4, so that the reversing valve 4 moves forward in an accelerated manner.

As shown in fig. 8, the piston 3 continues to move forward. Meanwhile, the reversing valve 4 accelerates forwards until the reversing valve 4 closes the high-pressure oil port 10 at the rear end of the piston 3. At the moment, the piston 3 just collides and transfers impact energy to the drilling tool to prepare for starting a new period of backward return motion; the reversing valve 4 then continues to move forward to the front side mechanical limit to wait for the next return stroke stage to contact the piston 3, and thus a cycle of movement is completed.

The oil circuit of this application is simpler, clear, and the simple spare part processing degree of difficulty that reduces of inside oil duct promotes structural strength, increases the life of spare part especially casing.

And the end face acting area for switching the oil pressure is large, so the oil pressure required by the same acting thrust is lower, the flow is larger, the lower acting oil pressure can reduce the damage of parts caused by high-pressure impact to a certain extent, and the consumption of the parts is reduced.

The alternative oil cavity changing positions are less, the contact area of the alternative oil cavity changing positions is large, and the low-pressure large-flow characteristics of the rock drill are added, so that the end surface oil pressure is more stable, the mutation is smaller, the reversing movement is more stable, the possibility of negative pressure on the end surface is reduced, the negative pressure probability is reduced when the throttle valve is matched with the acting cavity, the possibility of cavitation in the cavity of the rock drill is reduced to a certain degree, and the service life of the shell is prolonged.

The present application has been described in detail above, and specific examples thereof are used herein to explain the principles and implementations of the present application, which are presented solely to aid in understanding the present application and its core concepts. It should be noted that, for those skilled in the art, it is possible to make several improvements and modifications to the present application without departing from the principle of the present application, and such improvements and modifications also fall within the scope of the claims of the present application.

Claims

1. The impact mechanism of the rock drill is characterized by comprising an accommodating cavity, a variable oil path and a limiting part with a driving cavity, wherein a piston and a reversing valve are arranged in the accommodating cavity, the piston reciprocates in the accommodating cavity along the axial direction of the piston, one end of the variable oil path is connected with the reversing valve, the other end of the movable piston for switching the variable oil path is connected with a high-pressure oil path or an oil return path, and the variable oil path applies force to the piston through the reversing valve; the driving cavity is connected with the high-pressure oil way through the oil inlet throttling valve, the oil inlet throttling valve works to control whether the driving cavity is communicated with the high-pressure oil way, the reversing valve is partially connected with the driving cavity, and hydraulic pressure of the driving cavity acts on the reversing valve;

the reversing valve comprises a head end face close to the piston and a tail end face far away from the piston; the tail end of the piston is provided with a first channel which is communicated with the end surface of the rear side of the piston and the peripheral surface of the piston; the high-pressure oil way comprises a high-pressure oil port, the high-pressure oil port is arranged on the wall of the accommodating cavity, the oil return way comprises an oil return port, and the oil return port is arranged on the wall of the accommodating cavity;

when the return motion starts, the reversing valve is positioned at the foremost end of the stroke, the front end face of the reversing valve is communicated with the oil return path at the moment, the tail end face of the reversing valve is communicated with the oil return path, and the tail end face of the reversing valve head has hydraulic pressure difference to push the reversing valve to be positioned at the limit position of the front end of the stroke; the distance between the piston and the reversing valve is communicated with the oil return path, the front cavity of the piston is constantly connected with a high-pressure oil path, and the piston is driven by hydraulic pressure difference to do accelerated motion backwards; the piston moves backwards to be in contact with the reversing valve, and the piston can drive the reversing valve to continue moving backwards; when the reversing valve moves backwards for a certain distance, the oil return port is blocked, and the change oil way is disconnected with the first passage; the piston is contacted with the reversing valve, and the piston and the reversing valve synchronously move backwards in a speed reducing way; the piston and the reversing valve move backwards together to the limit position at the rearmost end, and the speed of the piston and the reversing valve is reduced to be close to 0 at the moment, so that the return motion is completed;

the piston still retains small kinetic energy when reaching the extreme position of the rearmost end, the piston is separated from the reversing valve, the space between the piston and the reversing valve is communicated with the high-pressure oil port, high-pressure oil enters the rear end face of the piston, and the piston moves forwards in an accelerated manner and enters a stroke; the front end face of the reversing valve is communicated with high-pressure oil, and the reversing valve is pressed at the rear end mechanical limit position; the piston continues to move forwards, the reversing valve keeps still until the variable oil way is communicated with the first channel, high-pressure oil enters a rear cavity of the reversing valve from the first channel and the variable oil way, and the reversing valve moves forwards in an accelerated manner; the piston continues to move forwards, meanwhile, the reversing valve accelerates forwards until the reversing valve closes the high-pressure oil port at the rear end of the piston, the piston just collides and moves, impact energy is transmitted to the drilling tool, and then the reversing valve continues to move forwards until the front side mechanical limit waits for the next return stroke stage to be contacted with the piston.

2. The impact mechanism of the rock drill according to claim 1, characterized in that a push spool is mounted in the drive chamber, the push spool acts on the reversing valve, the push spool is forced to move axially along the drive chamber, an inner groove is formed in the inner wall of the limiting member, the inner groove is not in contact with the push spool, and the high-pressure oil path is communicated with the drive chamber from the inner groove.

3. A percussion mechanism for a rockdrill according to claim 1, wherein the chamber has a plurality of surge tanks in the wall thereof, the surge tanks being located around the periphery of the piston, oil being present in the surge tanks.

4. The impact mechanism of the rock drill according to claim 1, characterized in that the variable oil path includes a first port and a second port disposed on the wall of the accommodating chamber, the first port is disposed on the outer peripheral side of the piston, and the second port is disposed on the end face of the reversing valve.

5. A percussion mechanism for a rock drill according to claim 4, characterised in that the first passage communicates with the varying oil circuit when the piston is moved to the predetermined position.

6. The impact mechanism of the rock drill according to claim 1, characterized in that the oil return path includes an oil return branch, the oil return branch is arranged on the wall of the accommodating chamber, and the oil return branch is located on the periphery of the piston; the outer circumferential surface of the piston is provided with a connecting groove; when the piston moves to a preset position, the connecting groove is communicated with the oil return branch and the change oil way.

7. The impact mechanism of rock drill according to claim 1, characterized in that the high pressure oil port is located on the outer periphery side of the reversing valve or the piston.

8. The impact mechanism of the rock drill according to claim 4, characterized in that a second channel is arranged in the reversing valve, and the second channel is communicated with the head end face and the tail end face of the reversing valve; and the second intersection is communicated with a second channel positioned at the tail end of the reversing valve.

9. A percussion mechanism for a rockdrill according to claim 8, wherein the retainer portion is located in the second channel; the reversing valve moves to be in contact with the limiting piece, and the limiting piece blocks the second channel at the moment; the limiting part is provided with a step surface, and the reversing valve moves to be in contact with the step surface, so that the second channel is blocked.

10. A percussion mechanism for a rock drill according to claim 8, wherein said oil return port is located at the periphery of the reversing valve and adjacent the rear end of the reversing valve; and in the reciprocating motion process of the reversing valve, the oil return port is communicated with the second channel or is blocked by the reversing valve.