A hydraulic breaker structure and method with self-cooling and adjustable impact force

Abstract

The present invention discloses a hydraulic breaker structure and method with self-cooling and adjustable impact force. A hole for the telescopic movement of the breaker piston rod is opened in the middle of the nitrogen chamber. Multiple through holes are opened in the upper part of the cylinder liner, which serves to communicate the internal space of the cylinder liner and the upper space of the annular piston. A sealed impact energy adjustment oil chamber is formed between the lower surface of the annular piston and the inner part of the inner cylinder body, the outside of the cylinder liner, and the lower inner surface of the outer cylinder body. The impact energy adjustment oil chamber controls the volume of the oil filled through a hydraulic control one-way valve, thereby pushing the annular piston to move and further changing the volume of the nitrogen chamber. A heat dissipation channel is provided between the inner and outer cylinder bodies, and the return oil of the hydraulic breaker enters the heat dissipation channel through the oil inlet to timely take away the heat brought by the adiabatic compression of the nitrogen in the nitrogen chamber. The present invention avoids the problem that the impact energy of the traditional hydraulic breaker is associated with the impact frequency and cannot be adjusted independently, and also avoids the heat accumulation generated by the adiabatic compression of the nitrogen in the nitrogen chamber.

Description

Technical Field

[0001] The present invention belongs to the technical field of hydraulic construction machinery, and particularly relates to a hydraulic breaker with adjustable impact energy and nitrogen chamber assisted heat dissipation installed on an excavator. Background Art

[0002] A hydraulic breaker is a vibration crushing device that converts hydraulic energy into impact kinetic energy and uses high-frequency impacts to break brittle objects, and is widely used in fields such as mine exploitation, construction, and road maintenance. The hydraulic breaker makes the piston reciprocate and strike the drill rod through the cooperation of the piston and the direction control valve, enabling the drill rod to do work externally to achieve the purpose of breaking rock and soil. Generally speaking, according to the different working media, hydraulic breakers can be divided into three types: pure hydraulic type, liquid-gas type, and nitrogen explosion type. Among them, the liquid-gas combined hydraulic breaker is the most widely used.

[0003] The technical parameters of a hydraulic breaker include impact energy, impact frequency, efficiency, etc. Among them, impact energy refers to the energy of the piston per impact, and is an important indicator for distinguishing the specifications of hydraulic breakers. The magnitude of the impact energy is proportional to the mass of the piston and the square of the speed of the drill rod when the piston strikes the drill rod. Since the mass of the piston is fixed, the magnitude of the impact energy is determined by the impact speed when the piston strikes the drill rod, and the impact speed is mainly related to the force during the piston stroke. Most of the hydraulic breakers on the market currently have a fixed impact energy. Although some hydraulic breakers can adjust the impact energy by adjusting the piston stroke and then adjusting the speed of the piston when it strikes the drill rod, this method cannot achieve the independent adjustment of frequency and impact energy. For example, when encountering hard rock and soil that requires high impact energy, the piston is adjusted to operate at its full stroke. The acceleration stage of the piston becomes longer, and the speed when it strikes the drill rod will increase, thus generating high impact energy. However, since the single stroke of the piston becomes longer, the impact frequency will decrease; when encountering soft rock conditions that require low impact energy, the piston is adjusted to operate with a short stroke. The acceleration stage of the piston becomes shorter, the speed when it strikes the drill rod decreases, and thus the impact energy becomes smaller, but the impact frequency of the piston will increase accordingly. The above-mentioned hydraulic breakers with fixed impact energy or non-independently adjustable impact energy often cannot well adapt to the complex and changeable working conditions in reality, which will inevitably cause a large amount of energy waste and is not conducive to reducing the use cost.

[0004] Currently, the patents related to hydraulic breakers with adjustable impact energy in China are almost blank. The patent applications that can be associated with this direction are: CN113251014A and CN217002446U "A Breaker with Separately Adjustable Impact Frequency and Impact Energy" disclose a method of using an industrial control computer to control proportional solenoid valves and servo motors to separately control the impact frequency and impact energy of a hydraulic breaker. However, this adjustment method adds additional external components such as an industrial control computer and a servo motor, and does not achieve the adjustment of impact energy from the mechanical structure.

[0005] In addition, there is a lot of energy loss in the transmission system and hydraulic system of the hydraulic breaker during use. These energy losses are dissipated in the form of heat, resulting in serious heat generation of the hydraulic breaker. It is understood that the continuous working time of the hydraulic breaker cold start is only 30 minutes, at which time the hydraulic oil temperature can reach more than 70 degrees. Excessive oil temperature will cause the oil properties to change and affect the service life of the hydraulic oil. High oil temperature will also affect the lubricity of the system, resulting in increased resistance and reduced system efficiency. The main reason for the increase in oil temperature is that the energy loss of the hydraulic system will be converted into heat. These losses include mechanical loss of the hydraulic pump, volume loss of the hydraulic pump, kinetic energy to internal energy loss when the drill rod hits, and adiabatic compression temperature rise loss of the nitrogen chamber. Among them, when the piston hits the drill rod, the nitrogen chamber does the most work, so the temperature rise caused by adiabatic compression of nitrogen during the piston return stroke is an important factor affecting the heat dissipation of the hydraulic breaker. Therefore, in order to avoid the compression of working time due to heat dissipation as much as possible, it is necessary to strengthen the heat dissipation of the hydraulic breaker, especially the heat dissipation of the nitrogen chamber.

[0006] At present, there are many patent applications for heat dissipation of hydraulic breaker in my country: CN114182778A "A Hydraulic Excavator Breaker Hammer Pipeline Auxiliary Heat Dissipation Device and Method" discloses a method of adding an electronic hydraulic oil radiator on the basis of the original hydraulic oil radiator to enhance heat dissipation; CN208633183U "A Hydraulic Breaker Cooling Device" discloses a cooling device in which a water cooling box with refrigerant is added to the hydraulic breaker, and the return oil pipe spirally dissipates the return oil through the water cooling box; CN111468218A "A Breaker for Mines" discloses a method of arranging a heat dissipation coil around the piston cavity and injecting coolant into the heat dissipation coil to absorb the heat of the piston cavity. All of the above heat dissipation methods are to dissipate heat to the piston cavity or return oil by adding a radiator or coolant, but in actual use, there are few patents for the problem that the heat generated by the adiabatic compression of nitrogen in the hydraulic breaker cannot be absorbed in time, resulting in an increase in the overall temperature of the hydraulic breaker. Summary of the invention

[0007] The invention provides a hydraulic breaker with adjustable impact energy and nitrogen chamber assisted heat dissipation, so as to solve the problem that the impact energy of the hydraulic breaker cannot be adjusted separately and the heat generated by the adiabatic compression of the nitrogen in the nitrogen chamber cannot be dissipated in time, resulting in heat accumulation and the increase of the overall temperature of the hydraulic breaker.

[0008] The present invention is implemented according to the following technical solutions:

[0009] The first aspect of the present invention discloses a hydraulic breaker structure with self-cooling and adjustable impact force, comprising a nitrogen chamber, a reversing valve and an acting body; the acting body includes a drill rod and a breaker piston rod; the nitrogen chamber includes an inner cylinder, an outer cylinder, an annular piston, a cylinder liner, a hydraulic check valve and an end cover; the inner cylinder is arranged in the outer cylinder, the cylinder liner is arranged in the inner cylinder, the annular piston is fitted with the inner side surface of the inner cylinder and the outer surface of the cylinder liner, and the space above the annular piston and the inner space of the cylinder liner are filled with nitrogen to form a nitrogen chamber, and the nitrogen chamber is sealed by connecting the end cover to the inner cylinder; a hole for the telescopic movement of the breaker piston rod is opened in the middle of the nitrogen chamber, and a plurality of through holes are opened in the upper part of the cylinder liner to communicate the inner space of the cylinder liner and the space above the annular piston; the lower surface of the annular piston and the inner part of the inner cylinder, the outer part of the cylinder liner and the inner lower surface of the outer cylinder form a sealed impact energy adjustment oil chamber; the impact energy adjustment oil chamber controls the volume of the oil filled through the hydraulic check valve, so as to push the annular piston to move, and then change the volume of the nitrogen chamber; a heat dissipation channel is arranged between the inner cylinder and the outer cylinder, and the oil inlet of the heat dissipation channel is connected to the oil return circuit of the breaker piston rod, and the return oil of the hydraulic breaker enters the heat dissipation channel through the oil inlet to timely take away the heat brought by the adiabatic compression of the nitrogen in the nitrogen chamber, and returns to the fuel tank from the oil outlet of the heat dissipation channel; the reversing valve includes a reversing valve body, a reversing valve cover and a reversing valve spool, and the reversing valve spool controls the on-off of the high-pressure oil in the rear chamber of the breaker piston rod to realize the reciprocating movement of the breaker piston rod.

[0010] As a preferred embodiment of the present invention, a spiral groove with a semi-circular cross-section is machined on the outer side surface of the inner cylinder, and a spiral groove with the same radius and a semi-circular cross-section is machined on the inner side surface of the outer cylinder. The two semi-circular spiral grooves form a spiral channel with a complete circular cross-section through the cooperation of the inner cylinder and the outer cylinder, and the spiral channel constitutes the heat dissipation channel.

[0011] As a preferred embodiment of the present invention, spiral grooves with a rectangular cross-section and the same pitch are machined between the spiral grooves on the outer surface of the inner cylinder, and spiral sealing rings are assembled in the spiral grooves with a rectangular cross-section to play a sealing role between two adjacent circular spiral grooves.

[0012] As a preferred embodiment of the present invention, a plurality of threaded holes are provided on the upper surfaces of the inner cylinder and the outer cylinder, and are connected to the threaded holes of the annular cover through annular cover connecting bolts.

[0013] As a preferred embodiment of the present invention, the cylinder liner is positioned through the annular groove on the lower surface of the end cover and the annular groove on the inner lower surface of the outer cylinder; an external thread is provided on the outer side surface of the end cover, and an internal thread is provided on the upper part of the inner side surface of the inner cylinder, and the two form a thread pair connection, so as to realize the functions of clamping the cylinder liner and sealing the nitrogen chamber.

[0014] As a preferred embodiment of the present invention, an upper cylinder seal ring is assembled in the annular groove on the lower surface of the end cap, and a lower cylinder seal ring is assembled in the annular groove on the inner lower surface of the outer cylinder body.

[0015] As a preferred embodiment of the present invention, a plurality of mounting holes penetrating the entire inner cylinder body are provided on the upper surface of the inner cylinder body, and the inner and outer cylinder connection bolts are connected to the threaded holes on the inner lower surface of the outer cylinder body after passing through the mounting holes.

[0016] As a preferred embodiment of the present invention, grooves for assembling the inner seal ring of the annular piston and the outer seal ring of the annular piston are respectively provided on the inner and outer surfaces of the annular piston, so as to prevent the impact energy adjustment oil cavity and the nitrogen chamber from communicating with each other and play a sealing role.

[0017] As a preferred embodiment of the present invention, the drill rod is fixed by a breaker drill rod pin, the breaker drill rod pin is fixed by a split pin, and the split pin is fixed by the expansion force between it and the outer cylinder body.

[0018] The second aspect of the present invention discloses an adjustment method for a hydraulic breaker structure with self-cooling and adjustable impact energy based on the above:

[0019] When working normally, the oil passage of the pilot operated check valve is not supplied with pressure oil, the pilot operated check valve is closed, and the volume of the oil filled in advance in the impact energy adjustment oil cavity in the impact energy adjustment cavity is fixed; when the breaker piston rod returns, the space of the nitrogen chamber is compressed, and the nitrogen is adiabatically compressed to store energy. When the breaker piston rod strokes, the compressed nitrogen adiabatically expands to generate a thrust, promoting the acceleration of the breaker piston rod;

[0020] When it is necessary to increase the impact energy of the hydraulic breaker, only need to supply pressure oil to the oil inlet passage of the pilot operated check valve and open the spool of the pilot operated check valve, then the oil will enter the impact energy adjustment oil cavity from the oil inlet passage of the pilot operated check valve through the oil outlet passage of the pilot operated check valve;

[0021] When it is necessary to reduce the impact energy of the hydraulic breaker, only need to supply control oil to the control oil passage of the pilot operated check valve and open the spool of the pilot operated check valve, then the oil can return from the impact energy adjustment oil tank to the oil tank through the oil outlet passage of the pilot operated check valve.

[0022] Advantages of the present invention:

[0023] The present invention provides a hydraulic breaker with adjustable impact energy and an auxiliary heat dissipation function in the nitrogen chamber, which avoids the problem that the impact energy of traditional hydraulic breakers cannot be adjusted and is difficult to adapt to complex and changeable working conditions, and circumvents the problem of the influence on the impact frequency caused by changing the impact energy by adjusting the piston stroke, greatly improving the applicability of the hydraulic breaker to complex and changeable working conditions in actual use.

[0024] The oil return auxiliary heat dissipation function of the spiral oil circuit in the nitrogen chamber optimizes the heat dissipation structure of the hydraulic breaker, avoiding the heat accumulation caused by adiabatic compression of the nitrogen in the nitrogen chamber, and plays an important role in improving the continuous use time and working efficiency of the hydraulic breaker. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The drawings, as a part of the present invention, are used to provide a further understanding of the present invention. The schematic embodiments and descriptions thereof are used to explain the present invention, but do not constitute an improper limitation to the present invention. Obviously, the drawings in the following description are only some embodiments, and those of ordinary skill in the art can obtain other drawings based on these drawings without creative efforts.

[0026] In the drawings:

[0027] Figure 1 is a perspective view of the hydraulic breaker of the present invention;

[0028] Figure 2 is Figure 1 an exploded view of part A in

[0029] Figure 3 is a cross-sectional view of the hydraulic breaker of the present invention;

[0030] Figure 4 is a structural schematic diagram of the inner cylinder of the nitrogen chamber component of the invention (a is a half cross-sectional view of the A-A plane, b is a front view);

[0031] Figure 5 is a full cross-sectional view of the outer cylinder of the nitrogen chamber component of the invention;

[0032] Figure 6 is a perspective view of the spiral seal ring of the present invention;

[0033] Figure 7 is a structural schematic diagram of the end cover of the nitrogen chamber component of the present invention (a is a half cross-sectional view of the B-B plane, b is a front view, c is a perspective view);

[0034] Figure 8 is a structural schematic diagram of the cylinder sleeve of the nitrogen chamber component of the present invention;

[0035] Figure 9 is a structural schematic diagram of the annular piston of the nitrogen chamber component of the invention (a is a cross-sectional view, b is a perspective view).

[0036] Reference Numerals: 1 - Ring cover connecting bolt; 2 - Ring cover; 3 - End cover; 4 - Sealing ring on cylinder liner; 5 - Cylinder liner; 6 - Inner sealing ring of ring piston; 7 - Ring piston; 8 - Connecting bolt between inner and outer cylinder bodies; 9 - Outer sealing ring of ring piston; 10 - Lower sealing ring of cylinder liner; 11 - Inner cylinder body; 12 - Spiral sealing ring; 13 - Drilling rod; 14 - Split pin; 15 - Breaker drilling rod pin; 16 - Directional control valve; 17 - Outer cylinder body; 17-1 - Oil inlet of piston chamber; 17-2 - Oil return port of piston chamber; 17-3 - Oil outlet of spiral channel; 18 - Hydraulic control check valve; 18-1 - Oil outlet path of hydraulic control check valve; 18-2 - Oil inlet of hydraulic control check valve; 18-3 - Control oil port of hydraulic control check valve; 19 - Nitrogen chamber; 20 - Breaker piston rod; 21 - Impact energy adjustment oil chamber; 22 - Annular groove; 23 - External thread; 24 - Annular groove; 25 - Through hole; 26 - Groove.

[0037] It should be noted that these drawings and textual descriptions are not intended to limit the scope of the concept of the present invention in any way, but rather to illustrate the concept of the present invention to those skilled in the art by reference to specific embodiments. Detailed Embodiments

[0038] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings in the embodiments of the present invention. The following embodiments are used to illustrate the present invention, but are not used to limit the scope of the present invention.

[0039] In the description of the present invention, it should be noted that the orientation or positional relationships indicated by the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "inner", "outer", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0040] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "mounted", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0041] A hydraulic breaker structure with self-cooling and adjustable impact force realizes impact energy adjustment by changing the volume of the nitrogen chamber and uses an external spiral oil circuit outside the nitrogen chamber for auxiliary heat dissipation to timely remove the heat generated by the adiabatic compression of nitrogen. The hydraulic breaker structure includes a nitrogen chamber, a reversing valve, and a working body.

[0042] As Figure 1 , Figure 2 , Figure 3 shown, the nitrogen chamber mainly consists of an inner cylinder body 11, an outer cylinder body 17, an annular piston 7, a cylinder liner 5, a hydraulic control check valve 18, and accessory seals and connectors. The seals include various O-rings, and the connections include bolts and an end cap 3.

[0043] The reversing valve 16 includes a reversing valve body, a reversing valve cover, a reversing valve spool, valve cover connection bolts, and valve body connection bolts. The reversing valve spool controls the on-off of the high-pressure oil in the rear chamber of the breaker piston rod 20 to realize the reciprocating motion of the breaker piston rod 20.

[0044] The working body includes a drill rod 13, a breaker piston rod 20, a split pin 14, and a breaker drill rod pin 15. The drill rod 13 is fixed by the breaker drill rod pin 15, the breaker drill rod pin 15 is fixed by the split pin 14, and the split pin 14 is fixed by the expansion force between it and the outer cylinder body 17.

[0045] The above-mentioned air chamber structure is further described below.

[0046] Continue to refer to Figure 1 , Figure 2 , Figure 3 shown, the nitrogen chamber includes an annular cover connection bolt 1, an annular cover 2, an end cap 3, an upper cylinder liner O-ring 4, a cylinder liner 5, an inner annular piston O-ring 6, an annular piston 7, an inner and outer cylinder body connection bolt 8, an outer annular piston O-ring 9, a lower cylinder liner O-ring 10, an inner cylinder body 11, a spiral O-ring 12, an outer cylinder body 17, a piston chamber oil inlet 17-1, a piston chamber oil return port 17-2, a spiral channel oil outlet 17-3. A hydraulic control check valve 18, a hydraulic control check valve oil outlet path 18-1, a hydraulic control check valve oil inlet 18-2, a hydraulic control check valve control oil port 18-3, a nitrogen chamber 19, a breaker piston rod 20, and an impact energy adjustment oil chamber 21.

[0047] The internal space of the inner cylinder block 11 is divided into two parts by the cylinder liner 5 and the annular piston 7. The annular piston 7 forms a fit with the inner side surface of the inner cylinder block 11 and the outer surface of the cylinder liner 5. The upper space of the annular piston 7 and the inner space of the cylinder liner 5 are filled with nitrogen gas, namely the nitrogen chamber 19. A hole for the telescopic movement of the breaker piston rod 20 is opened in the middle of the nitrogen chamber 19. When the breaker piston rod 20 returns, it compresses the space of the nitrogen chamber 19 to store energy. During the stroke, the nitrogen gas in the nitrogen chamber 19 adiabatically expands to assist the acceleration of the breaker piston rod 20. The upper part of the cylinder liner 5 has a plurality of through holes 25, which play a role in communicating the inner space of the cylinder liner 5 and the upper space of the annular piston 7. Nitrogen gas can pass through these through holes 25 unobstructed, as Figure 8 shown. A sealed space is formed between the lower part of the annular piston 7, the inner part of the inner cylinder block 17, and the outer part of the cylinder liner 5, namely the impact energy adjustment oil chamber 21. The impact energy adjustment oil chamber 21 controls the volume of the oil filled through the pilot-operated check valve 18, thereby pushing the annular piston 7 to move, and further changing the volume of the nitrogen chamber. The initial amount of nitrogen gas filled in the nitrogen chamber 19 is fixed, and the volume is changed, which is equivalent to changing the initial pressure of the nitrogen chamber 19. Then the thrust received by the breaker piston rod 20 during the stroke changes with the change of the volume of the nitrogen chamber 19, and finally realizes the adjustment of the impact energy of the hydraulic breaker by changing the oil in and out of the impact energy adjustment oil chamber 21. This adjustment method avoids the problem that the impact energy of the traditional hydraulic breaker is associated with the impact frequency and cannot be adjusted independently.

[0048] As Figure 9 shown, there are grooves 26 on the inner and outer surfaces of the annular piston 7 for assembling the inner sealing ring 6 of the annular piston and the outer sealing ring 9 of the annular piston, so as to prevent the impact energy adjustment oil chamber 21 and the nitrogen chamber 19 from communicating with each other and play a sealing role.

[0049] As Figure 7 shown, the cylinder liner 5 is positioned through the annular groove 24 on the lower surface of the end cover 3 and the annular groove 22 on the inner lower surface of the outer cylinder block 17; a cylinder liner upper sealing ring 4 is assembled in the annular groove 24 on the lower surface of the end cover 3, and a cylinder liner lower sealing ring 10 is assembled in the annular groove 22 on the inner lower surface of the outer cylinder block 17; the outer side surface of the end cover 3 has an external thread 23, and the upper part of the inner side surface of the inner cylinder block 11 has an internal thread, and the two form a screw pair connection, so as to realize the function of clamping the cylinder liner 5 and closing the nitrogen chamber 19. The inner cylinder block 11 is connected to the outer cylinder block 17 by four inner and outer cylinder block connecting bolts 8.

[0050] It should be further noted that the oil inlet 18-2 of the pilot-operated check valve is the oil inlet and outlet of the oil in the impact energy adjustment oil chamber. When oil enters from this oil port, the oil in the impact energy adjustment oil chamber 21 increases, and the nitrogen chamber pressure increases. By controlling the oil port 18-3 of the pilot-operated check valve to open the pilot-operated check valve 18, the oil in the impact energy adjustment oil chamber 21 can be discharged through the oil inlet 18-2 of the pilot-operated check valve, reducing the pressure in the nitrogen chamber.

[0051] The principle of a hydraulic breaker with adjustable impact energy lies in:

[0052] (a)When working normally, the control oil port 18-3 of the pilot-operated check valve is not supplied with pressure oil, the pilot-operated check valve 18 is closed, and the oil in the impact energy adjustment chamber cannot flow back. Then the volume of the pre-filled oil in the impact energy adjustment oil chamber 21 is fixed. Since the volume of the enclosed space inside the inner cylinder block 11 is fixed, the volume of the nitrogen chamber 19 is also fixed. When the piston rod 20 of the breaker returns, it compresses the space of the nitrogen chamber 19, and the nitrogen is adiabatically compressed to store energy. When the piston rod 20 of the breaker makes a stroke, the compressed nitrogen adiabatically expands to generate a thrust, which promotes the acceleration of the piston rod 20 of the breaker.

[0053] (b)When it is necessary to increase the impact energy of the hydraulic breaker, only need to supply pressure oil to the inlet port 18-2 of the pilot-operated check valve to open the spool of the pilot-operated check valve. Then the oil will enter the impact energy adjustment oil chamber 21 from the inlet port 18-2 of the pilot-operated check valve through the outlet oil path 18-1 of the pilot-operated check valve. The volume of the impact energy adjustment oil chamber 21 increases, and then the volume of the nitrogen chamber is compressed. Then the pressure generated by the piston rod 20 of the breaker compressing the nitrogen chamber increases as the volume of the nitrogen chamber decreases, that is, the thrust of the nitrogen in the nitrogen chamber 19 on the piston rod 20 during the stroke can be increased. The stroke of the piston rod 20 of the breaker remains unchanged, and the thrust increases, so the speed when hitting the drill rod 13 increases. Finally, the purpose of increasing the impact energy of the hydraulic breaker by reducing the volume of the nitrogen chamber is achieved.

[0054] (c)On the contrary, when it is necessary to reduce the impact energy of the hydraulic breaker, only need to supply control oil to the control oil port 18-3 of the pilot-operated check valve to open the spool of the pilot-operated check valve. Then the oil can return from the impact energy adjustment oil tank 21 to the oil tank through the outlet oil path 18-1 of the pilot-operated check valve. The volume of the impact energy adjustment oil chamber 21 decreases, and then the volume of the nitrogen chamber expands. Then the pressure generated by the piston rod 20 of the breaker compressing the nitrogen chamber decreases as the volume of the nitrogen chamber increases, and then the thrust of the nitrogen in the nitrogen chamber 19 on the piston rod 20 during the stroke decreases. The stroke of the piston rod 20 of the breaker remains unchanged, and the thrust decreases, so the speed when hitting the drill rod 13 decreases. Finally, the purpose of reducing the impact energy of the hydraulic breaker by increasing the volume of the nitrogen chamber is achieved.

[0055] The above nitrogen chamber is further described as follows.

[0056] Such as Figure 4 、 Figure 5 、 Figure 6As shown in the figure, a spiral groove with a semi-circular cross-section is machined on the outer side surface of the inner cylinder block 11, and a spiral groove with a semi-circular cross-section of the same radius is machined on the inner side surface of the outer cylinder block 17. The two semi-circular spiral grooves form a spiral channel with a complete circular cross-section through the cooperation of the inner cylinder block 11 and the outer cylinder block 17. An oil inlet and an oil outlet are respectively opened at the bottom and the top of the spiral channel on one side of the outer cylinder block 17. The oil inlet is connected to the oil return circuit of the breaker piston rod, facilitating the oil return fluid of the hydraulic breaker to enter the spiral channel through the oil inlet in time to take away the heat brought by the adiabatic compression of the nitrogen in the nitrogen chamber, and returning to the fuel tank from the oil outlet of the spiral channel to complete the heat exchange and absorption.

[0057] A spiral groove with a rectangular cross-section of the same pitch is machined between the spiral grooves on the outer surface of the inner cylinder block 11, and a spiral sealing ring 12 is assembled in the spiral groove with the rectangular cross-section, playing a sealing role between two adjacent circular spiral grooves.

[0058] It should be further noted that the piston chamber oil inlet 17-1 is the oil inlet when the breaker is working, the piston chamber oil return port 17-2 is the oil return port of the breaker piston rod, and this port is connected to the spiral oil passage of the nitrogen chamber. The spiral channel oil outlet 17-3 is the oil outlet when the breaker is working.

[0059] The principle of the hydraulic breaker with auxiliary heat dissipation for the nitrogen chamber lies in:

[0060] A spiral groove with a semi-circular cross-section is machined on the outer side surface of the inner cylinder block 11, and a spiral groove with a semi-circular cross-section of the same radius is machined on the inner side surface of the outer cylinder block 17. The two semi-circular spiral grooves form a spiral channel with a complete circular cross-section through the cooperation of the inner cylinder block 11 and the outer cylinder block 17. The lower inlet of the spiral channel is connected to the piston chamber oil return port 17-2, and the upper outlet is connected to the spiral channel oil outlet 17-3. A spiral groove with a rectangular cross-section of the same pitch is machined between the spiral grooves on the outer surface of the inner cylinder block 11, and a spiral sealing ring 12 is assembled in the spiral groove with the rectangular cross-section, playing a sealing role between two adjacent circular spiral grooves. There are threaded holes on the upper surfaces of the inner cylinder block 11 and the outer cylinder block 17, and they are connected through the annular cover connection bolts 1 with the threaded holes of the annular cover 2.

[0061] The nitrogen in the nitrogen chamber 19 of the hydraulic breaker is compressed by the breaker piston rod 20 during operation. The heat generated by the nitrogen during each adiabatic compression is taken away by the oil in the spiral oil return circuit surrounding the surface of the inner cylinder block, avoiding the problem that the overall temperature of the hydraulic breaker rises due to heat accumulation and optimizing the heat dissipation structure of the hydraulic breaker.

[0062] In summary, the present invention provides a hydraulic breaker with separately adjustable impact energy and an auxiliary heat dissipation function in the nitrogen chamber, which avoids the problem that the impact energy of traditional hydraulic breakers cannot be adjusted and is difficult to adapt to complex and changeable working conditions, and circumvents the problem of the impact on the impact frequency caused by changing the impact energy by adjusting the piston stroke, greatly improving the adaptability of the hydraulic breaker to complex and changeable working conditions in actual use.

[0063] The oil return auxiliary heat dissipation function of the spiral oil circuit in the nitrogen chamber optimizes the heat dissipation structure of the hydraulic breaker, avoids the heat accumulation of nitrogen in the nitrogen chamber due to adiabatic compression, and plays an important role in increasing the continuous use time of the hydraulic breaker and improving work efficiency.

[0064] In the specification provided herein, a large number of specific details are set forth. It will be understood, however, that embodiments of the invention may be practiced without these specific details. In some instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description.

[0065] In addition, those skilled in the art will appreciate that although some embodiments described herein include certain features contained in other embodiments but not others, the combinations of features of different embodiments are equally within the scope of the present invention and form different embodiments. For example, in the above embodiments, those skilled in the art can use them in combination according to the known technical solutions and the technical problems to be solved by this application.

[0066] The above are only preferred embodiments of the present invention, and do not impose any form of limitation on the present invention. Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art of this patent can make some modifications or equivalent changes and modifications within the scope of the technical solution of the present invention by using the technical content prompted above. However, as long as the content does not depart from the technical solution of the present invention, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention still fall within the scope of the present invention.

Claims

1. A hydraulic breaker structure with self-cooling and adjustable impact force, characterized in that: it includes a nitrogen chamber, a reversing valve and a working body; the working body includes a drill rod and a breaker piston rod; the nitrogen chamber includes an inner cylinder, an outer cylinder, an annular piston, a cylinder liner, a hydraulic control check valve and an end cover; the inner cylinder is arranged in the outer cylinder, the cylinder liner is arranged in the inner cylinder, the annular piston is fitted with the inner side surface of the inner cylinder and the outer surface of the cylinder liner, and the upper space of the annular piston and the inner space of the cylinder liner are filled with nitrogen to form a nitrogen chamber, and the nitrogen chamber is sealed by connecting the end cover to the inner cylinder; a hole for the telescopic movement of the breaker piston rod is opened in the middle of the nitrogen chamber, and a plurality of through holes are opened in the upper part of the cylinder liner to communicate the inner space of the cylinder liner and the upper space of the annular piston; a sealed impact energy adjustment oil chamber is formed between the lower surface of the annular piston and the inner part of the inner cylinder, the outer part of the cylinder liner and the inner lower surface of the outer cylinder; the impact energy adjustment oil chamber controls the volume of the oil filled through the hydraulic control check valve, thereby pushing the annular piston to move, and further changing the volume of the nitrogen chamber; a heat dissipation channel is arranged between the inner and outer cylinders, and the oil inlet of the heat dissipation channel is connected to the oil return circuit of the breaker piston rod, and the oil return oil of the hydraulic breaker enters the heat dissipation channel through the oil inlet to timely take away the heat brought by the adiabatic compression of the nitrogen in the nitrogen chamber, and returns to the fuel tank from the oil outlet of the heat dissipation channel; the reversing valve includes a reversing valve body, a reversing valve cover and a reversing valve spool, and the reversing valve spool controls the on-off of the high-pressure oil in the rear chamber of the breaker piston rod to realize the reciprocating movement of the breaker piston rod; a semi-circular spiral groove is machined on the outer side surface of the inner cylinder, and a semi-circular spiral groove with the same radius is machined on the inner side surface of the outer cylinder. The two semi-circular spiral grooves form a complete circular spiral channel through the cooperation of the inner cylinder and the outer cylinder, and this spiral channel constitutes the heat dissipation channel.

2. The hydraulic breaker structure with self-cooling and adjustable impact force according to claim 1, characterized in that: a spiral groove with a rectangular cross-section and the same pitch is machined between the spiral grooves on the outer surface of the inner cylinder, and a spiral sealing ring is assembled in the spiral groove with the rectangular cross-section to play a sealing role between two adjacent circular spiral channels.

3. The hydraulic breaker structure with self-cooling and adjustable impact force according to claim 1, characterized in that: a plurality of threaded holes are provided on the upper surfaces of the inner cylinder and the outer cylinder, and are connected to the threaded holes of the annular cover through annular cover connecting bolts.

4. The hydraulic breaker structure with self-cooling and adjustable impact force according to claim 1, characterized in that: the cylinder liner is positioned by the annular groove on the lower surface of the end cover and the annular groove on the inner lower surface of the outer cylinder; an external thread is provided on the outer side surface of the end cover, and an internal thread is provided on the upper part of the inner side surface of the inner cylinder, and the two form a threaded pair connection, so as to realize the functions of clamping the cylinder liner and closing the nitrogen chamber.

5. The hydraulic breaker structure with self-cooling and adjustable impact force according to claim 4, characterized in that: An upper sealing ring of the cylinder liner is assembled in an annular groove on the lower surface of the end cover, and a lower sealing ring of the cylinder liner is assembled in an annular groove on the inner lower surface of the outer cylinder body.

6. The structure of a hydraulic breaker with self-cooling and adjustable impact force according to claim 1, characterized in that: A plurality of mounting holes penetrating the entire inner cylinder body are provided on the upper surface of the inner cylinder body. After the inner and outer cylinder connection bolts pass through the mounting holes, they are connected to threaded holes on the inner lower surface of the outer cylinder body.

7. The structure of a hydraulic breaker with self-cooling and adjustable impact force according to claim 1, characterized in that: Grooves for assembling the inner sealing ring of the annular piston and the outer sealing ring of the annular piston are provided on the inner and outer surfaces of the annular piston, so as to prevent the impact energy adjustment oil chamber and the nitrogen chamber from communicating with each other and play a sealing role.

8. The structure of a hydraulic breaker with self-cooling and adjustable impact force according to claim 1, characterized in that: The drill rod is fixed by a breaker drill rod pin, the breaker drill rod pin is fixed by a split pin, and the split pin is fixed by the expansion force between the split pin and the outer cylinder body.

9. An adjustment method for the structure of a hydraulic breaker with self-cooling and adjustable impact force according to any one of claims 1 to 8, characterized in that: When working normally, the control oil circuit of the pilot-operated check valve does not conduct pressure oil, the pilot-operated check valve is closed, and the volume of the oil filled in advance in the impact energy adjustment oil chamber in the impact energy adjustment chamber is fixed; when the breaker piston rod returns, the space of the nitrogen chamber is compressed, and the nitrogen is adiabatically compressed to store energy. When the breaker piston rod strokes, the compressed nitrogen adiabatically expands to generate a thrust force to accelerate the breaker piston rod; When it is necessary to increase the impact energy of the hydraulic breaker, only need to make the inlet oil circuit of the pilot-operated check valve conduct pressure oil and open the spool of the pilot-operated check valve, then the oil will enter the impact energy adjustment oil chamber from the inlet oil circuit of the pilot-operated check valve through the outlet oil circuit of the pilot-operated check valve; When it is necessary to reduce the impact energy of the hydraulic breaker, only need to make the control oil circuit of the pilot-operated check valve conduct control oil and open the spool of the pilot-operated check valve, then the oil can return from the impact energy adjustment oil tank to the oil tank through the outlet oil circuit of the pilot-operated check valve.

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