Impact device, hydraulic power head and rock drill

Abstract

The application discloses an impact device, a hydraulic power head and a rock drill, which comprise an impact shell and an impact piston, and the impact shell is provided with a reversing device and a frequency modulation device; the impact piston is provided with a first matching surface towards the front end and a second matching surface towards the tail end, the acting area of the second matching surface is larger than that of the first matching surface, the inner wall of the impact shell is respectively formed with a front cavity for matching with the first matching surface and a rear cavity for matching with the second matching surface, the front cavity is connected with a first high-pressure oil source through a first oil way, the rear cavity is connected with the reversing device through a second oil way, the reversing device is provided with a high-pressure oil port connected with the first high-pressure oil source and a low-pressure oil port connected with a first low-pressure oil source, the reversing device is used for controlling the rear cavity to be connected with the first low-pressure oil source when the impact piston moves to a first preset range and is used for making the rear cavity to be connected with the first high-pressure oil source when the impact piston moves to a second preset range; and the frequency modulation device is used for adjusting the size of the second preset range.

Description

Technical Field

[0001] The present invention relates to the field of rock drilling and percussion drilling technology, and in particular to a percussion device. In addition, the present invention also relates to a hydraulic power head and a rock drill including the percussion device. Background Art

[0002] Tunnel construction requires pipe roof construction, geological forecasting, coring, anchor bolting, grouting reinforcement, and geological improvement. Hydraulic impact drills are widely used in these operations. During forward drilling, the impact device of the hydraulic drill head, mounted at the rear of the gearbox, delivers high-frequency impacts to the drill bit through the impact piston. This impact energy is transmitted through the drill pipe to the drill bit, where it impacts and damages the rock surface. This impact force significantly accelerates drilling speed and improves construction efficiency.

[0003] Hydraulic impact devices come in a variety of structural forms. Sleeve-valve impact devices, among them, have numerous moving parts, and the reversing valve is typically mounted at the rear of the piston. This results in a large overall impact device, high oil consumption, and significant leakage. Furthermore, the sleeve-valve structure has a complex oil circuit, making it impossible to adjust the impact frequency. The impact device only has a single frequency, resulting in poor geological adaptability. For example, the impact device disclosed in patent publication number CN117823033A includes a cylinder, an impact piston, a flow distribution valve, a push rod, an oil distribution cap, and an end cap. The flow distribution valve, oil distribution cap, and push rod are positioned at the rear of the impact piston. As the impact piston moves under the action of hydraulic oil, changes in the oil circuit alter the force and motion of the flow distribution valve, oil distribution cap, and push rod, thereby changing the oil circuit pressure on the stepped surfaces of the impact piston, achieving reciprocating motion of the impact piston. This impact device, with its moving parts all mounted at the rear of the piston, results in a large overall size and increased oil consumption. At the same time, this type of device has many moving parts, the movement states of each part are complex, and the failure rate is relatively high. At the same time, this impact device cannot be frequency-modulated, and the impact frequency and impact power cannot be adjusted.

[0004] The reversing valve of a core-valve impact device is not coaxial with the impact piston, which effectively reduces the size of the impact device. However, the reversing valve uses a spring to switch the direction of the valve core. Under high-frequency impact, the spring's fatigue life is reduced, making it impossible to ensure the impact device's long-term continuous operation. For example, the invention patent disclosed in publication number: CN107044258A discloses a multi-frequency hydraulic rotary impact drill, which includes an impact mechanism, a rotation mechanism, and a reverse mechanism connected in sequence. The impact mechanism is externally mounted with a reversing mechanism and a reversing valve. The reversing valve is mounted on the side of the impact piston and adopts a core-valve structure, which allows the impact device to have a smaller structural size. However, the reversing valve uses a spring to switch the direction of the spring. Under high-frequency impact, the fatigue strength requirements of the spring are higher, and the spring life is significantly reduced, affecting the performance of the impact device.

[0005] On the other hand, the impact frequency adjustment structure of the current hydraulic impact device usually relies on manual mechanical adjustment. At the tunnel face, manual adjustment poses a great safety hazard. Summary of the Invention

[0006] The present invention provides an impact device, a hydraulic power head and a rock drill to solve the technical problems that the existing impact device has a large number of parts, resulting in complex motion states and a high failure rate, and a reversing device using a spring with a short service life.

[0007] According to one aspect of the present invention, an impact device is provided, comprising an impact shell and an impact piston penetrating the inner cavity of the impact shell, the impact shell being provided with a reversing device and a frequency modulation device; the impact piston having a first mating surface arranged toward the front end and a second mating surface arranged toward the rear end, the effective area of ​​the second mating surface being larger than the effective area of ​​the first mating surface, the inner wall of the impact shell being respectively formed with a front cavity for mating with the first mating surface and a rear cavity for mating with the second mating surface, the front cavity being connected to a first high-pressure oil source via a first oil circuit, the rear cavity being connected to the reversing device via a second oil circuit, the reversing device having a high-pressure oil port connected to the first high-pressure oil source and a low-pressure oil port connected to the first low-pressure oil source, the reversing device being used to control the rear cavity to connect to the first low-pressure oil source when the impact piston moves to a first preset range, and to connect the rear cavity to the first high-pressure oil source when the impact piston moves to a second preset range; the frequency modulation device being used to adjust the size of the second preset range.

[0008] As a further improvement of the above technical solution, a first control chamber is provided on the inner wall of the impact shell, the first control chamber is connected to the reversing device via a third oil circuit, and the first control chamber is connected to the frequency modulation device via a fourth oil circuit; the impact shell is provided with a plurality of signal oil circuits connected to the frequency modulation device distributed along the axial direction, and the frequency modulation device is used to respectively control the on and off of each of the signal oil circuits and thereby control the size of the second preset range.

[0009] As a further improvement of the above technical solution, a frequency modulation valve core is provided in the frequency modulation device, the first end of the frequency modulation device is connected to the second high-pressure oil source, and the first end of the frequency modulation device is in the same direction as the front end of the impact device; an elastic reset part is provided between the frequency modulation valve core and the inner wall of the second end of the frequency modulation device, and the frequency modulation valve core is used to be driven by the second high-pressure oil source to move toward the second end and thereby block the signal oil circuit in turn.

[0010] As a further improvement of the above technical solution, the two ends of the reversing device are respectively connected to the first high-pressure oil source, and a distribution sleeve and a reversing valve core are provided in the reversing device, and the effective area of ​​the first end of the reversing valve core is larger than the effective area of ​​the second end; the reversing device is provided with a distribution chamber, a first chamber, and a second chamber distributed in the axial direction in sequence, the distribution chamber is connected to the first control chamber via a third oil circuit, the first chamber is connected to the first low-pressure oil source, and the second chamber is connected to the rear chamber via a second oil circuit; the reversing valve core is used to connect the first chamber with the second chamber when it moves to a preset position, or to connect the second chamber with the first high-pressure oil source connected to the second end of the reversing device when it moves to a preset position.

[0011] As a further improvement of the above technical solution, a second control chamber is provided on the inner wall of the impact housing, and the second control chamber is connected to the first chamber via a fifth oil circuit; a drainage groove is provided on the outer wall of the impact piston, which is used to connect the third oil circuit and the fifth oil circuit when the impact piston moves to a preset range to a third preset range.

[0012] As a further improvement of the above technical solution, the inner wall of the impact shell is provided with a plurality of lubrication cavities and a lubrication oil circuit connecting the lubrication cavities and the fifth oil circuit, or the inner wall of the impact shell is provided with a plurality of lubrication cavities and a lubrication oil port corresponding to each of the lubrication cavities, and the reversing device is provided with a lubrication oil circuit connected to the first chamber corresponding to each of the lubrication oil ports.

[0013] As a further improvement of the above technical solution, the second end of the frequency modulation device is connected to a second low-pressure oil source.

[0014] As a further improvement of the above technical solution, a stop cavity is provided on the inner wall of the impact shell, which is arranged between the front end of the impact shell and the front cavity, and is used to form a blind cavity when the impact piston moves toward the first end until the outer wall of the impact piston cooperates with the stop cavity, thereby braking the impact piston.

[0015] According to another aspect of the present invention, a hydraulic power head is provided, to which the above-mentioned impact device is applied. The hydraulic power head includes a reduction gear box and a front guide device.

[0016] According to another aspect of the present invention, a rock drill is provided, which includes the above-mentioned impact device.

[0017] The present invention has the following beneficial effects:

[0018] The high-pressure oil flows through the first oil circuit to the front chamber, and the reversing device connects the first high-pressure oil source to the second oil circuit to the rear chamber. Since the effective area of ​​the first mating surface is smaller than the effective area of ​​the second mating surface, the impact piston moves toward the front end and hits the drill tail under the action of the area difference, and now enters the first preset range. Under the action of the reversing device, the second oil circuit is connected to the first low-pressure oil source, and the rear chamber is connected to low-pressure oil. Under the action of the pressure difference between the front and rear chambers, the impact piston performs a return acceleration movement toward the rear chamber. During the return movement, when the impact piston moves to the second preset range, the reversing device is activated to connect the second oil circuit to the first high-pressure oil source, and the rear chamber is connected to high-pressure oil. Since the effective area of ​​the first mating surface is smaller than the effective area of ​​the second mating surface, the impact piston performs a return deceleration movement, and completes a cycle of action after the deceleration reaches 0. The impact piston continues to move toward the front end and hits the drill tail. The structural principle of this impact device is simplified, and the moving parts are The number of parts is small, which greatly reduces the failure rate. The movement logic is simple and clear, the movement process of the impact piston is clear, which effectively improves the accuracy of dynamic calculations and improves the reliability of the whole machine. The reversing device is connected to the impact piston in multiple oil circuits, and reversing is achieved based on hydraulics as the impact piston movement process changes. The structure is simple and avoids the use of springs, avoiding high-frequency movement causing spring fatigue failure and equipment failure. The second preset range is adjusted by the frequency modulation device, and then the position of the impact piston for return deceleration movement is changed, so as to adjust the impact piston stroke and then realize the adjustment of its impact frequency and impact power. The operation is simple and safe. The reversing device and the frequency modulation device are integrated on the impact housing, with a compact structure and reduced space occupancy. Through the preset oil circuit and oil port matching connection, disassembly and maintenance are convenient and no pipeline connection is required, which improves disassembly and assembly efficiency and streamlines the structure.

[0019] In addition to the above-described objects, features and advantages, the present invention has other objects, features and advantages. The present invention will be further described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0021] Figure 1 It is a structural schematic diagram of a preferred embodiment of the present invention;

[0022] Figure 2 Schematic diagram of the internal structure of a preferred embodiment of the present invention;

[0023] Figure 3 This is a schematic diagram of the internal structure of the preferred embodiment of the present invention when the impact piston hits the shank;

[0024] Figure 4 This is a schematic diagram of the internal structure of the impact piston during the return stroke of a preferred embodiment of the present invention;

[0025] Figure 5 2. It is a schematic diagram of the internal structure of the impact piston when it is decelerated to zero according to a preferred embodiment of the present invention;

[0026] Figure 6 It is a structural schematic diagram of a hydraulic power head according to a preferred embodiment of the present invention.

[0027] Legend:

[0028] 1. Impact housing; 101. Reversing device; 102. Frequency modulation device; 103. Front chamber; 104. Rear chamber; 105. Stop chamber; 106. First oil circuit; 107. Second oil circuit; 108. Third oil circuit; 109. Fourth oil circuit; 110. Fifth oil circuit; 111. Sixth oil circuit; 112. First signal oil circuit; 113. Second signal oil circuit; 114. Third signal oil circuit; 115. Lubricating oil circuit; 2. Rear cover; 3. , impact piston; 31, threaded hole; 4, reversing valve core; 41, flow hole; 42, distribution chamber; 5, distribution sleeve; 6, first end cover; 7, second end cover; 8, frequency modulation valve core; 9, elastic return member; 10, third end cover; 11, fourth end cover; 12, first step seal; 13, second step seal; 14, sealing ring; 15, first high-pressure oil source; 16, first low-pressure oil source; 17, second high-pressure oil source; 18, second low-pressure oil source. DETAILED DESCRIPTION

[0029] The embodiments of the present invention are described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered below.

[0030] like Figures 1 to 5 As shown, the impact device of this embodiment includes an impact shell 1 and an impact piston 3 penetrating the inner cavity of the impact shell 1. The impact shell 1 is provided with a reversing device 101 and a frequency modulation device 102; the impact piston 3 has a first mating surface arranged toward the front end and a second mating surface arranged toward the rear end, the effective area of ​​the second mating surface is larger than the effective area of ​​the first mating surface, and the inner wall of the impact shell 1 is respectively formed with a front cavity 103 for mating with the first mating surface and a rear cavity 104 for mating with the second mating surface. The front cavity 103 is formed through the second mating surface. An oil circuit 106 is connected to the first high-pressure oil source 15, and the rear chamber 104 is connected to the reversing device 101 via the second oil circuit 107. The reversing device 101 has a high-pressure oil port connected to the first high-pressure oil source 15 and a low-pressure oil port connected to the first low-pressure oil source 16. The reversing device 101 is used to control the rear chamber 104 to be connected to the first low-pressure oil source 16 when the impact piston 3 moves to the first preset range, and to connect the rear chamber 104 to the first high-pressure oil source 15 when the impact piston 3 moves to the second preset range; the frequency modulation device 102 is used to adjust the size of the second preset range.

[0031] The working principle of this impact device is as follows: high-pressure oil flows through the first oil passage 106 to the front chamber 103, and the reversing device 101 connects the first high-pressure oil source 15 to the second oil passage 107 to the rear chamber 104. Because the effective area of ​​the first mating surface is smaller than the effective area of ​​the second mating surface, the impact piston 3 moves toward the front end and hits the drill tail under the action of the area difference, and then enters the first preset range. Under the action of the reversing device 101, the second oil passage 107 is connected to the first low-pressure oil source 16, and the rear chamber 104 is connected to low-pressure oil. Under the action of the pressure difference between the front and rear chambers 104, the impact piston 3 performs a return acceleration movement toward the rear chamber 104. During the return movement, when the impact piston 3 moves to the second preset range, the reversing device 101 is activated to connect the second oil passage 107 to the first high-pressure oil source 15, and the rear chamber 104 is connected to high-pressure oil. Because the effective area of ​​the first mating surface is smaller than the effective area of ​​the second mating surface, the impact piston 3 performs a return deceleration movement. After the deceleration reaches 0, one cycle of action is completed, and the impact piston 3 continues to move toward the front end. Impact drill tail; The structural principle of the impact device is simple, the number of moving parts is small, the failure rate is greatly reduced, the movement logic is concise and clear, the movement process of the impact piston 3 is clear, the accuracy of dynamic calculation is effectively improved, and the reliability of the whole machine is improved; the reversing device 101 is connected to the impact piston 3 in multiple oil circuits, and reversing is achieved based on hydraulic pressure as the movement process of the impact piston 3 changes. The structure is simple and avoids the use of springs, avoiding high-frequency movement causing spring fatigue failure and equipment failure; the second preset range is adjusted by the frequency modulation device 102, and then the position of the impact piston 3 for return deceleration movement is changed, so as to adjust the stroke of the impact piston 3 and then realize the adjustment of its impact frequency and impact power, which is easy and safe to operate; the reversing device 101 and the frequency modulation device 102 are integrated on the impact shell 1, with a compact structure and reduced space occupancy; through the preset oil circuit and oil port matching connection, disassembly and maintenance are convenient and no pipeline connection is required, thereby improving disassembly and assembly efficiency and streamlining the structure.

[0032] In one embodiment, a first control chamber is provided on the inner wall of the impact housing 1, and the first control chamber is connected to the reversing device 101 via the third oil circuit 108, and the first control chamber is connected to the frequency modulation device 102 via the fourth oil circuit 109; the impact housing 1 is provided with a plurality of signal oil circuits connected to the frequency modulation device 102 distributed along the axial direction, and the frequency modulation device 102 is used to control the on and off of each signal oil circuit respectively and thus control the size of the second preset range. For example, in one embodiment, a first signal oil circuit 112, a second signal oil circuit 113 and a third signal oil circuit 114 are sequentially provided along the axial direction, and the first signal oil circuit 112 is located on the side close to the front end of the impact housing 1. When the three signal oil circuits are all opened, it is a high-frequency impact gear. When the impact piston 3 moves back to the first mating surface and reaches the first signal oil circuit 112, the front chamber 103 and the first signal oil circuit 112 and the fourth oil circuit 109 are connected to the first control chamber, that is, high pressure The oil is connected to the reversing device 101 through the first signal oil circuit 112, the fourth oil circuit 109, the first control chamber and the third oil circuit 108, so that the reversing device 101 is actuated to change the state of the reversing device 101, so that the rear chamber 104 is switched from low-pressure oil to high-pressure oil, and a return deceleration motion is started, and the movement cycle time of the impact piston 3 is short; similarly, when the first signal oil circuit 112 is blocked, the impact piston 3 returns to the position of the first matching surface reaching the second signal oil circuit 113 and starts the return deceleration motion, increasing the movement cycle time, and this is the medium-frequency impact gear; when the first signal oil circuit 112 and the second signal oil circuit 113 are blocked, the first matching surface reaches the position of the third signal oil circuit 114 and starts the return deceleration movement, and the movement cycle time is increased, and this is the low-frequency impact gear; wherein, by designing the structure of the frequency modulation device 102, the last signal oil circuit close to the rear chamber 104 side cannot be blocked;

[0033] Specifically, a frequency modulation valve core 8 is provided in the frequency modulation device 102, and the first end of the frequency modulation device 102 is connected to the second high-pressure oil source 17. The first end of the frequency modulation device 102 is in the same direction as the front end of the impact device; an elastic reset member 9 is provided between the frequency modulation valve core 8 and the inner wall of the second end of the frequency modulation device 102, and the frequency modulation valve core 8 is used to be driven by the second high-pressure oil source 17 to move toward the second end and thereby block the signal oil path in turn; a third end cover 10 is provided at the first end of the frequency modulation device 102 and a fourth end cover 11 is provided at the second end to facilitate disassembly for maintenance Replacement; the frequency modulation device 102 overcomes the elastic force of the frequency modulation spring under the action of the liquid pressure of the second high-pressure oil source 17 to change the position of the frequency modulation valve core 8, thereby blocking the signal oil circuit, and as the frequency modulation device 102 moves toward the second end, the first signal oil circuit 112 and the second signal oil circuit 113 are blocked in turn; by changing the input liquid pressure, the axial position of the frequency modulation valve core 8 is changed to change the number of signal oil circuit blockages, thereby realizing the switching of the impact frequency of the impact device, effectively avoiding manual mechanical adjustment, reducing safety hazards, and improving efficiency.

[0034] Among them, when the input liquid pressure of the frequency modulation device 102 is 0, all signal oil circuits are in the open state, which is the high-frequency impact gear; in some embodiments, a limiting structure can be set in the frequency modulation device 102, that is, the second end of the frequency modulation valve core 8 is designed to be limited, and after the frequency modulation valve core 8 moves to the second end to abut the limiting structure, it only blocks the secondary signal oil circuit close to the rear cavity 104 to ensure that the last signal oil circuit cannot be blocked, that is, after the input liquid pressure reaches the maximum design value or higher, it is the low-frequency impact gear.

[0035] Furthermore, the second end of the frequency modulation device 102 is connected to the second low-pressure oil source 18, so that the hydraulic oil leaked from the frequency modulation valve returns to the oil tank.

[0036] In one embodiment, a first end cover 6 and a second end cover 7 are respectively provided at both ends of the reversing device 101, and both ends of the reversing device 101 are respectively connected to a first high-pressure oil source 15. A distribution sleeve 5 and a reversing valve core 4 are provided in the reversing device 101. The first end of the reversing valve core 4 is in the same direction as the front end of the impact device, and the effective area of ​​the first end of the reversing valve core 4 is larger than the effective area of ​​the second end. A distribution chamber 42, a first chamber, and a second chamber are sequentially provided in the axial direction of the reversing device 101. The distribution chamber 42 is connected to the first control chamber via a third oil passage 108, the first chamber is connected to the first low-pressure oil source 16, and the second chamber is connected to the rear chamber 104 via a second oil passage 107. The reversing valve core 4 is used to connect the first chamber with the second chamber or move to a preset position when it moves to a preset position. When the second chamber is in the state of being ... The reversing valve core 4 moves toward the first end, so that the high-pressure oil at the second end of the reversing valve core 4 is guided into the second chamber through the flow hole 41 at the tail end of the reversing valve core 4, and then the high-pressure oil is guided to the rear chamber 104 through the second oil path 107, so that the impact piston 3 starts to decelerate in the return stroke, and starts to accelerate in the return stroke after the deceleration reaches 0. After moving to the position of the signal oil path opened by the first matching surface, the front chamber 103 and the first control chamber are disconnected, and the distribution chamber 42 is switched to low-pressure oil. Under the action of the pressure difference, the reversing valve starts to move toward the second end again, that is, the reversing valve core 4 and the impact piston 3 both complete a cycle of action; the reversing device 101 has a simple structure and realizes reversing by hydraulic pressure. It moves with the impact piston 3 and cooperates with the frequency modulation device 102 to realize hydraulic reversing control and reversing frequency control. The structure is simple and avoids the use of springs, thus avoiding high-frequency movement causing spring fatigue failure and equipment failure; wherein, a second control chamber is provided on the inner wall of the impact shell 1, and the second control chamber is connected to the first chamber via the fifth oil circuit 110, thereby connecting to the first low-pressure oil source 16; the outer wall of the impact piston 3 is provided with a drainage groove, which is used to connect the first control chamber and the second control chamber when the impact piston 3 moves to a preset range to a third preset range, so that the low-pressure oil is guided to the distribution chamber 42 through the first chamber, the fifth oil circuit 110, the drainage groove, and the third oil circuit 108 to change the state of the reversing valve core 4; in this impact device, only the impact piston 3, the reversing valve core 4 and the frequency modulation valve core 8 are actuating elements, with a simple structure and high integration, low failure rate, long service life and easy later maintenance.

[0037] Among them, in order to facilitate the maintenance and replacement of the impact piston 3, a rear cover 2 is set at the rear end of the impact shell 1, a sealing ring 14 is set at the connecting and fitting part, and a threaded hole 31 is set at the rear end of the impact piston 3 for threaded connection with the tool. After disassembly, the impact piston 3 can be removed by the tool.

[0038] In one embodiment, the inner wall of the impact shell 1 is provided with multiple lubrication chambers and a lubrication oil circuit 115 connecting the lubrication chambers and the fifth oil circuit 110, that is, the lubrication oil circuit 115 is all low-pressure oil supply and can be used as an oil return circuit. Specifically, low-pressure oil is introduced into multiple positions on the inner wall of the impact shell 1, such as the positions where the first step seal 12 and the second step seal 13 are provided at both ends to ensure the lubrication of the seals, and at the same time, the leaked hydraulic oil is returned to the oil tank through the lubrication oil circuit 115, so as to avoid the leakage oil pressure from damaging the seal and improve the reliability of the device.

[0039] In other embodiments, the inner wall of the impact housing 1 may be provided with a plurality of lubrication cavities and a lubrication oil port corresponding to each lubrication cavity, and the reversing device 101 may be provided with a lubrication oil path 115 connected to the first chamber corresponding to each lubrication oil port.

[0040] It should be understood that a flow hole 41 connected to the second end of the reversing valve core 4 is provided at an axial preset position on the reversing valve core 4, for connecting the second chamber with the first high-pressure oil source 15 when the reversing valve core 4 moves to the preset position.

[0041] In one embodiment, a stop chamber 105 is provided on the inner wall of the impact shell 1, which is arranged between the front end of the impact shell 1 and the front chamber 103, and is used to form a blind cavity when the impact piston 3 moves toward the first end until the outer wall of the impact piston 3 cooperates with the stop chamber 105, thereby braking the impact piston 3 to prevent the impact piston 3 from hitting the shell and avoiding damage to the equipment; the stop chamber 105 is connected to the first oil circuit 106 through the sixth oil circuit 111, and only a high-pressure oil interface needs to be retained outside the shell.

[0042] On the other hand, this embodiment also provides a hydraulic power head, referring to Figure 6 , the above-mentioned impact device is applied, and the hydraulic power head includes a reduction box and a front guide device.

[0043] On the other hand, this embodiment also provides a rock drill, which is equipped with the above-mentioned impact device.

[0044] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. An impact device comprising an impact housing (1) and an impact piston (3) penetrating an inner cavity of the impact housing (1), characterized in that: The impact housing (1) is provided with a reversing device (101) and a frequency modulation device (102); the impact piston (3) has a first mating surface arranged toward the front end and a second mating surface arranged toward the rear end, the effective area of ​​the second mating surface is larger than the effective area of ​​the first mating surface, and the inner wall of the impact housing (1) is respectively formed with a front cavity (103) for mating with the first mating surface and a rear cavity (104) for mating with the second mating surface, the front cavity (103) is connected to a first high-pressure oil source (15) via a first oil path (106), and the rear cavity (104) is connected to the reversing device (101) via a second oil path (107), and the reversing device (101) has There is a high-pressure oil port connected to a first high-pressure oil source (15) and a low-pressure oil port connected to a first low-pressure oil source (16); the reversing device (101) is used to control the rear chamber (104) to be connected to the first low-pressure oil source (16) when the impact piston (3) moves to a first preset range, and to control the rear chamber (104) to be connected to the first high-pressure oil source (15) when the impact piston (3) moves to a second preset range; the frequency modulation device (102) is used to adjust the size of the second preset range; a first control chamber is provided on the inner wall of the impact housing (1), the first control chamber is connected to the reversing device (101) via a third oil path (108), and the first control chamber is connected to the first low-pressure oil source (16) via a fourth oil path (109). The frequency modulation device (102); the impact housing (1) is provided with a plurality of signal oil paths connected to the frequency modulation device (102) distributed along the axial direction, and the frequency modulation device (102) is used to respectively control the on-off of each of the signal oil paths and thus control the size of the second preset range; a frequency modulation valve core (8) is provided in the frequency modulation device (102), the first end of the frequency modulation device (102) is connected to the second high-pressure oil source (17), and the first end of the frequency modulation device (102) is in the same direction as the front end of the impact device; an elastic reset member (9) is provided between the frequency modulation valve core (8) and the inner wall of the second end of the frequency modulation device (102), and the frequency modulation valve core (8) is used to be affected by the second high-pressure oil source (17). The second high-pressure oil source (17) drives the reversing device (101) to move toward the second end and thereby sequentially block the signal oil circuit; the two ends of the reversing device (101) are respectively connected to the first high-pressure oil source (15); a distribution sleeve (5) and a reversing valve core (4) are provided in the reversing device (101); the effective area of ​​the first end of the reversing valve core (4) is larger than the effective area of ​​the second end; the reversing device (101) is sequentially provided with a distribution chamber (42), a first chamber, and a second chamber distributed along the axial direction; the distribution chamber (42) is connected to the first control chamber via a third oil circuit (108); the first chamber is connected to the first low-pressure oil source (16); and the second chamber is connected to the rear chamber (104) via a second oil circuit (107);The reversing valve core (4) is used to connect the first chamber with the second chamber when it moves to a preset position, or to connect the second chamber with a first high-pressure oil source (15) connected to the second end of the reversing device (101) when it moves to a preset position.

2. The impact device according to claim 1, characterized in that A second control chamber is provided on the inner wall of the impact housing (1), and the second control chamber is communicated with the first chamber via a fifth oil passage (110); a drainage groove is provided on the outer wall of the impact piston (3), for communicating the third oil passage (108) with the fifth oil passage (110) when the impact piston (3) moves to a preset third preset range.

3. The impact device according to claim 2, characterized in that The inner wall of the impact housing (1) is provided with a plurality of lubricating cavities and a lubricating oil path (115) connecting the lubricating cavities and the fifth oil path (110); or, the inner wall of the impact housing (1) is provided with a plurality of lubricating cavities and a lubricating oil port corresponding to each of the lubricating cavities is provided, and the reversing device (101) is provided with a lubricating oil path (115) connected to the first chamber corresponding to each of the lubricating oil ports.

4. The impact device according to claim 1, characterized in that The second end of the frequency modulation device (102) is connected to a second low-pressure oil source (18).

5. The impact device according to claim 1, characterized in that The inner wall of the impact housing (1) is provided with a stop chamber (105), which is arranged between the front end of the impact housing (1) and the front chamber (103) and is used to form a blind cavity when the impact piston (3) moves toward the first end until the outer wall of the impact piston (3) cooperates with the stop chamber (105), thereby braking the impact piston (3).

6. A hydraulic power head, characterized in that: The impact device according to any one of claims 1 to 5 is applied, wherein the hydraulic power head comprises a reduction box and a front guide device.

7. A rock drill, characterized in that: The impact device according to any one of claims 1 to 5 is used.

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