Hydraulic energy absorber suitable for full-power impact performance durability test of hydraulic rock drill

Abstract

The utility model discloses a hydraulic energy absorber suitable for a full-power impact performance durability test of a hydraulic rock drill. The hydraulic energy absorber comprises a shell, a valve core, a retaining body and a rear cover, wherein a front cylinder body, a rear cylinder body, a front cylinder body spacer sleeve, a rear cylinder body spacer sleeve, a front-end wear-resistant copper sleeve, a rear-end wear-resistant copper sleeve, a one-way valve and the like are nested in the shell. O-shaped rings and step seals are nested in inner holes and outer circles of the front cylinder body and the rear cylinder body, so that oil leakage of the hydraulic energy absorber is prevented. The hydraulic energy absorber can simulate the condition that energy in a drill rod is continuously absorbed when a hydraulic rock drill performs rock drilling. The hydraulic energy absorber is good in energy absorption effect, capable of adapting to various machine types and environments, good in impact resistance stability, capable of bearing impact of a hydraulic rock drill for a long time, convenient to use, simple in structure, easy to manufacture, small in size, low in cost, low in cost in the using process, capable of being repeatedly used for a long time, free of frequent replacement of parts and suitable for popularization and application. Transportation and debugging are convenient and fast, and environmental protection is achieved.

Description

Technical Field

[0001] This utility model belongs to the field of hydraulic energy absorber technology, specifically to a hydraulic energy absorber suitable for durability testing of the full-power impact performance of hydraulic rock drills. Background Technology

[0002] Hydraulic rock drills are highly technical machines characterized by high-speed impact and high-torque rotation. Powered by high-pressure fluid, they output significantly more energy than traditional pneumatic rock drills. Their impact mechanism is a valve-controlled hydraulic follow-up mechanism, delivering high impact energy. Hydraulic rock drills are among the most precision-engineered mining machines, making their manufacturing and use challenging. Conducting experimental research on the performance indicators of hydraulic rock drills and establishing objective evaluation standards for their long-term impact performance is beneficial for ensuring product quality and promoting the continuous development of hydraulic rock drilling technology. It also provides a basis for structural improvements, determining a rational structure, and enabling the debugging and evaluation of the overall machine's performance. Furthermore, it can further improve the stability of hydraulic rock drill performance and increase user satisfaction.

[0003] Since the 1980s, testing of hydraulic rock drills has only focused on impact energy, rotational torque, and rotational speed. However, this can only verify whether the hydraulic rock drill can reach the design level in a short period of time. It cannot verify whether the internal structure design of the hydraulic rock drill is reasonable under long-term operation, whether the materials and heat treatment processes used for certain parts are appropriate, or verify the service life of certain parts and the approximate maintenance time of the hydraulic rock drill.

[0004] The parameters that users truly value in hydraulic rock drills are not only those mentioned above (impact energy, rotational torque, and rotational speed), but also the overall performance stability of the machine. This is especially important because the movement of a hydraulic rock drill is high-frequency and high-impact, which places higher demands on the stability of its various components. Therefore, after the development, design, and production of a hydraulic rock drill are completed, durability testing is essential. This process verifies the performance and stability of the drill, ensures product quality, achieves user satisfaction, and reduces maintenance costs.

[0005] Currently, there are two main research directions for hydraulic energy absorbers used in impact performance testing of hydraulic rock drills. One is a steel ball energy absorber, which utilizes friction between steel balls and between the steel balls and the tube wall to generate frictional heat and absorb impact energy. However, it has shortcomings; the steel balls are easily damaged during long-term endurance tests. For hydraulic rock drills requiring endurance tests of up to 500 hours or even longer, the steel ball energy absorber requires frequent replacement of steel balls during testing, which is not only time-consuming but also costly. The other is a tubular energy absorber developed by the Changsha Research Institute of Mining and Metallurgy. This type of energy absorber uses a long tube structure. The internal structure contains friction plates and energy-absorbing materials, with multiple friction points connected in series, each with a gradually increasing coefficient of friction as the wave propagates, to minimize the total reflected energy. However, it also has the following disadvantages: 1. The structure is several meters long, making it inconvenient to use; 2. It is difficult to manufacture; 3. Due to the limitations of size and energy-absorbing materials, it is not suitable for testing high impact energy; 4. Replacing the measuring rod is inconvenient, as one type of energy absorber corresponds to only one type of measuring rod tail; 5. During prolonged impacts, the internal energy-absorbing material is prone to high temperatures due to the inability to dissipate and absorb the converted heat in time, which can lead to damage to the energy absorber material. Utility Model Content

[0006] 1. Technical problems to be solved

[0007] The purpose of this invention is to overcome the deficiencies and defects in the background technology described above, and to provide a hydraulic energy absorber suitable for durability testing of the full-power impact performance of hydraulic rock drills. During the durability test of the hydraulic rock drill, the energy absorbs the impact energy during the full-power impact process of the hydraulic rock drill, establishes an objective evaluation standard for the impact performance of the hydraulic rock drill, and improves the stability of the hydraulic rock drill's performance.

[0008] 2. Technical Solution

[0009] A hydraulic energy absorber suitable for durability testing of full-power impact performance of a hydraulic rock drill includes: a housing; the right end of the housing is connected to a rear cover by bolts; the left end of the housing is connected to a stop body by bolts; a valve core is installed inside the housing; a plug is installed at the bottom of the housing; a plug is installed on the right end face of the housing; a plug is installed at the top of the housing; a one-way valve is installed inside the housing by threaded connection; an oil inlet is installed at the top of the housing by threaded connection; an oil drain is installed on the right side of the housing by threaded connection; the left side of the rear cover is close to the rear cylinder; a step seal is fixedly installed on the inner surface of the rear cylinder; an O-ring is fixedly installed on the outer surface of the rear cylinder; a rear wear-resistant copper sleeve is nested inside the rear cylinder; the left end of the rear cylinder is close to the rear cylinder retainer; the right end of the stop body is close to the front cylinder; a step seal is installed on the inner surface of the front cylinder; an O-ring is fixedly installed on the outer surface of the front cylinder; a front wear-resistant copper sleeve is nested inside the front cylinder; and the right end of the front cylinder is close to the front cylinder retainer.

[0010] Preferably, the front cylinder block, the front cylinder block sleeve, the rear cylinder block sleeve, and the rear cylinder block each have a different number of oil drain holes.

[0011] Preferably, the housing is equipped with a one-way valve, which is connected to the oil inlet through a process hole. The one-way valve ensures that the hydraulic oil can only enter the main pressure chamber from the oil inlet direction and cannot return from the main pressure chamber to the oil inlet direction, thereby further ensuring that the hydraulic oil inside the main pressure chamber is in a high-pressure state.

[0012] Preferably, the inner surfaces of the front and rear wear-resistant copper sleeves are provided with rectangular balance grooves with a width-to-depth ratio of 1:1. The number of rectangular balance grooves with a width-to-depth ratio of 1:1 on the inner surfaces of the front and rear wear-resistant copper sleeves is 3 to 6. The front and rear wear-resistant copper sleeves are fitted with the valve core with a small clearance. The front and rear wear-resistant copper sleeves provide support for the repeated movement of the valve core.

[0013] Preferably, the maximum inner diameter of the anti-reverse body is 0.4 mm larger than the maximum outer diameter of the valve core, but not more than 1 mm, and the left inner diameter of the anti-reverse body is 0.4 mm larger than the leftmost outer diameter of the valve core, but not more than 0.8 mm.

[0014] Preferably, the rear cover has a small through hole with a diameter of 4-6 mm in the center to ensure gas flow and to verify whether the O-ring and step seal are leaking oil.

[0015] Preferably, the valve core has a rectangular balance groove with a width-to-depth ratio of 1:1, and the number of rectangular balance grooves with a width-to-depth ratio of 1:1 on the valve core is 3 to 6. The fitting clearance between the rectangular balance groove section of the valve core and the rear cylinder block retainer is 0.05 to 0.08 mm.

[0016] Preferably, the relationship between the maximum inner diameter D2 of the anti-reverse body and the maximum outer diameter d20 of the front cylinder is d20≥1.4D2.

[0017] Preferably, the diameter of the inner hole on the right side of the oil drain hole on the front cylinder block sleeve is smaller than the diameter of the inner hole on the left side of the oil drain hole.

[0018] 3. Beneficial effects

[0019] This invention utilizes the incompressibility of hydraulic oil to convert the impact energy of a rock drill into heat energy, simulating the continuous absorption of energy from the drill rod during rock drilling. Throughout the process, as long as the supply flow of the hydraulic energy absorber is sufficient, it can absorb various high-impact energies generated by the hydraulic rock drill. The hydraulic energy absorber can be used with various models and adapt to various environments; it also boasts excellent energy absorption, good impact resistance and stability, and can withstand the impact of the hydraulic rock drill for extended periods. It is easy to use, has a simple structure, is simple to manufacture, small in size, low in cost, and can be reused for a long time without frequent parts replacement. Transportation and debugging are convenient and quick, and it is more environmentally friendly. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the main body of the hydraulic energy absorber of this utility model;

[0021] Figure 2 This is a schematic diagram of the internal structure of the hydraulic energy absorber of this utility model;

[0022] Figure 3 This is a schematic diagram of the hydraulic energy absorber of this utility model;

[0023] Figure 4 This is a partially enlarged schematic diagram of the hydraulic energy absorber of this utility model;

[0024] The labels in the diagram are as follows: 1. Valve core; 2. Anti-reverse valve; 3. Bolt; 4. Housing; 5. Oil inlet; 6. Plug; 7. Check valve; 8. Rear cylinder block sleeve; 9. Rear cylinder block; 10. Rear end wear-resistant copper sleeve; 11. Plug; 12. Bolt; 13. Rear cover; 14. O-ring; 15. Drain nozzle; 16. Step seal; 17. Plug; 18. Front cylinder block sleeve; 19. Plug; 20. Front cylinder block; 21. Front end wear-resistant copper sleeve; 22. Plug; 23. O-ring; 24. Step seal; 25. Secondary pressure chamber; 26. Main pressure chamber; 27. Main return oil hole. Detailed Implementation

[0025] To facilitate understanding of this utility model, it will be described more fully and in detail below with reference to the accompanying drawings and preferred embodiments. However, the scope of protection of this utility model is not limited to the specific embodiments described below. Unless otherwise defined, all technical terms used below have the same meaning as commonly understood by those skilled in the art. The technical terms used herein are for the purpose of describing specific embodiments only and are not intended to limit the scope of protection of this utility model.

[0026] A hydraulic energy absorber suitable for durability testing of full-power impact performance of a hydraulic rock drill includes: a housing; the right end of the housing is connected to a rear cover by bolts; the left end of the housing is connected to a stop body by bolts; a valve core is installed inside the housing; a plug is installed at the bottom of the housing; a plug is installed on the right end face of the housing; a plug is installed at the top of the housing; a one-way valve is installed inside the housing by threaded connection; an oil inlet is installed at the top of the housing by threaded connection; an oil drain is installed on the right side of the housing by threaded connection; the left side of the rear cover is close to the rear cylinder; a step seal is fixedly installed on the inner surface of the rear cylinder; an O-ring is fixedly installed on the outer surface of the rear cylinder; a rear wear-resistant copper sleeve is nested inside the rear cylinder; the left end of the rear cylinder is close to the rear cylinder retainer; the right end of the stop body is close to the front cylinder; a step seal is installed on the inner surface of the front cylinder; an O-ring is fixedly installed on the outer surface of the front cylinder; a front wear-resistant copper sleeve is nested inside the front cylinder; and the right end of the front cylinder is close to the front cylinder retainer.

[0027] Reference Figure 1 The hydraulic energy absorber housing shown has an annular groove, which can be connected and fixed by bolts or studs; the valve core (1) is the main part that bears the impact of the hydraulic energy absorber. After the valve core (1) is processed, it needs to be nitrided or surface hardened. The length of the valve core (1) protruding from the anti-reverse body (2) is approximately between 40 and 60 mm; the oil inlet (5) and the plug (6) on the top surface of the housing (4) are milled flat; the center line of the oil inlet (5) and the center line of the plug (6) on the top surface of the housing (4) should be kept at a certain distance to avoid interference; the number of bolts connecting the housing (4) and the anti-reverse body (2) is not less than 8, and the bolt grade is not less than 10.9.

[0028] See Figure 2The relationship between the maximum inner diameter D2 of the anti-reverse body (2) and the maximum outer diameter d20 of the front cylinder (20) is that d20 ≥ 1.4D2. The anti-reverse body (2) limits the left displacement of the front cylinder (20) and the valve core (1). The housing (4) limits the right displacement of the front cylinder sleeve (18). The front cylinder guide sleeve (18) limits the right displacement of the front cylinder (20) and the front wear-resistant copper sleeve (21). The front cylinder (20) limits the left displacement of the front cylinder sleeve (18) and the front wear-resistant copper sleeve (21). The front cylinder sleeve (18) is fitted with the housing (4) and the front cylinder (20) in a small clearance fit. The front cylinder (20) is fitted with the front wear-resistant sleeve (21) in a transition fit. The front cylinder (20) is fitted with the housing (4) in a small clearance fit. The valve core (1) is fitted with the front cylinder (20) in a small clearance fit. The valve core (1) is fitted with the front wear-resistant copper sleeve (21) and the rear wear-resistant copper sleeve (10) in a small clearance fit, wherein the fit clearance between the valve core (1) and the front wear-resistant copper sleeve (21) and the rear wear-resistant copper sleeve (10) is smaller than the fit clearance between the rear cylinder block sleeve (8) and the valve core (1); the fit clearance between the valve core (1) and the right side of the side drain hole of the front cylinder block sleeve (18) is a small clearance fit, and the fit clearance between the valve core (1) and the left side of the side drain hole is a large clearance fit; the rear cylinder block (9) limits the right side displacement of the rear cylinder block sleeve (8) and the rear wear-resistant copper sleeve (10); the rear cylinder block sleeve (8) limits the left side displacement of the rear cylinder block (9) and the rear wear-resistant copper sleeve (10); the housing (4) limits the left side displacement of the rear cylinder block sleeve (8), and the rear cover (13) limits the right side displacement of the rear cylinder block (9). The valve core (1) is fitted with the front cylinder (20) and the rear cylinder (9) with a large clearance. The outer surface of the front cylinder (20) is fitted with an O-ring (23), and the inner surface is fitted with a step seal (24). Under the dual action of the O-ring (23) and the step seal (24), the left side of the hydraulic energy absorber will not leak oil. The outer surface of the rear cylinder (9) is fitted with an O-ring (14), and the inner surface is fitted with a step seal (16). Under the dual action of the O-ring (14) and the step seal (16), the right side of the hydraulic energy absorber will not leak oil. The plug (22) and plug (1) 9) Plugs (17), (11) and (7) ensure that the housing (4) will not leak oil due to the process hole; the valve core (1) and the anti-reverse body (2) are fitted with a large clearance; the rear cylinder (9) and the rear cover (13) are fitted with a small clearance; the left side of the rear cylinder sleeve (8), the rear cylinder (9) and the housing (4) are fitted with a small clearance, and the right side of the rear cylinder sleeve (8) and the housing (4) are fitted with a large clearance; the rear wear-resistant copper sleeve (10) and the rear cylinder (9) are fitted with a transition fit.

[0029] See Figure 3 The hydraulic oil enters the housing (4) through the inlet (5). After entering the housing (4), the hydraulic oil is divided into two paths through the oil hole. One path enters the secondary pressure chamber (25) directly through the oil hole, and the other path enters the main pressure chamber (26) through the check valve (7). The check valve (7) only allows hydraulic oil to enter the main pressure chamber (26) through the inlet (5), but does not allow hydraulic oil in the main pressure chamber (26) to enter the inlet (5) through the check valve (7). This ensures that the hydraulic oil pressure in the main pressure chamber (26) can always be kept at a stable high pressure.

[0030] Referring to Figure (4), there is a relatively large gap between the secondary pressure chamber (25) and the main return oil hole (27) due to the valve core (1) and the front cylinder sleeve (18). Therefore, the hydraulic oil in the secondary pressure chamber (25) can enter the main return oil hole (27). Thus, the hydraulic oil enters from the inlet (5), then enters the main return oil hole (27) through the secondary pressure chamber (25), and then returns to the oil tank through the main return oil hole (27), thereby realizing the full flow of hydraulic oil and carrying away the heat generated by the hydraulic energy absorber due to absorbing the impact energy of the hydraulic rock drill.

[0031] Through the above technical solutions, when the hydraulic rock drill is subjected to a durability impact performance test, the impact energy of the hydraulic rock drill is transmitted to the valve core (1), and the valve core (1) further transmits the impact energy to the hydraulic oil in the secondary pressure chamber (25) and the main pressure chamber (26), thereby further converting the impact energy into heat energy. In this process, the front wear-resistant copper sleeve (21) and the rear wear-resistant copper sleeve (10) mainly play the role of supporting the valve core (1) to ensure that the valve core (1) can reciprocate normally. On the other hand, the O-ring (23), the step seal (24), the O-ring (14) and the step seal (16) can ensure that the hydraulic oil leaked from each component in the hydraulic energy absorber returns to the oil tank through the drain hole and will not cause side leakage. At the same time, the plugs in the hydraulic energy absorber also ensure to a certain extent that the drain holes will not leak oil. The pressurized oil in the secondary pressure chamber (25) enters the main return oil hole (27) through the gap between the valve core (1) and the front cylinder sleeve (18). Then, the hydraulic oil returns to the oil tank through the drain nozzle (15), which to a certain extent ensures the free flow of hydraulic oil inside the hydraulic energy absorber. The impact energy of the hydraulic rock drill is converted into heat energy by the hydraulic energy absorber. The heat energy generated by the conversion is carried away by the free flow of hydraulic oil between the hydraulic energy absorbers. The heat energy is further consumed by the radiator of the hydraulic oil station, realizing a transfer of energy. In this way, the hydraulic energy absorber will not cause the temperature to rise too high due to absorbing too much impact energy. In addition, there is a special circulating cooling water system at the return oil line of the hydraulic energy absorber, which can further remove the heat generated by the hydraulic oil due to absorbing impact energy. Furthermore, if the impact energy is too large, causing the gap between the valve core (1) and the front cylinder sleeve (18) to disappear, the hydraulic oil will not enter the main return oil hole (27) from the secondary pressure chamber (25). This will cause the hydraulic oil pressure in the secondary pressure chamber (25) to increase sharply, and further cause the hydraulic oil pressure in the main pressure chamber (26) to increase sharply, thereby increasing the force of the hydraulic oil on the valve core (1), forcing the valve core (1) to return to its original position more quickly. When the gap between the valve core (1) and the front cylinder sleeve (18) appears, the hydraulic oil can return to the oil tank from the secondary pressure chamber (25) through the main return oil hole (27) to achieve normal heat transfer. During this process, because the check valve (7) ensures that the hydraulic oil can only enter the main pressure chamber (26) from the inlet (5), the pressure in the main pressure chamber (26) will remain high after the valve core (1) returns to its original position. This will further enhance the force of the hydraulic oil on the valve core (1), enabling the valve core (1) to respond more quickly when subjected to greater impact.

Claims

1. A hydraulic energy absorber suitable for durability testing of full-power impact performance of hydraulic rock drills, comprising a housing (4), characterized in that, The right end of the housing (4) is connected to the rear cover (13) by bolt (12), and the left end of the housing (4) is connected to the anti-reverse body (2) by bolt (3). The housing (4) contains a valve core (1). The bottom of the housing (4) contains a plug (22), a plug (19), and a plug (17). The right end face of the housing (4) contains a plug (11). The top of the housing (4) contains a plug (6). The inside of the housing (4) is connected by a threaded connection to a one-way valve (7). The top of the housing (4) is connected by a threaded connection to an oil inlet (5). The right side of the housing (4) is connected by a threaded connection to an oil drain (15). The left side of the rear cover (13) is in contact with the rear cylinder (9). An O-ring (14) is fixedly installed on the outer surface of the rear cylinder (9), and a Step seal (16) is fixedly installed on the inner surface. A rear wear-resistant copper sleeve (10) is nested inside the rear cylinder (9). The left end of the rear cylinder is close to the rear cylinder sleeve (8). The right end of the anti-reverse body (2) is close to the front cylinder (20). An O-ring (23) is fixedly installed on the outer surface of the front cylinder (20), and a Step seal (24) is fixed on the inner surface. A front wear-resistant copper sleeve (21) is nested inside the front cylinder (20). The right end of the front cylinder (20) is close to the front cylinder sleeve (18).

2. A hydraulic energy absorber suitable for durability testing of full-power impact performance of hydraulic rock drills according to claim 1, characterized in that, The front cylinder block (20), the front cylinder block sleeve (18), the rear cylinder block sleeve (8), and the rear cylinder block (9) are each provided with a different number of oil drain holes.

3. A hydraulic energy absorber suitable for durability testing of full-power impact performance of hydraulic rock drills according to claim 1, characterized in that, The housing (4) is equipped with a one-way valve (7), which is connected to the oil inlet (5) through a process hole. The one-way valve (7) ensures that the hydraulic oil can only enter the main pressure chamber (26) from the oil inlet direction and cannot return from the main pressure chamber (26) to the oil inlet direction, thereby further ensuring that the hydraulic oil inside the main pressure chamber (26) is in a high-pressure state.

4. A hydraulic energy absorber suitable for durability testing of full-power impact performance of hydraulic rock drills according to claim 1, characterized in that, The inner surfaces of the front wear-resistant copper sleeve (21) and the rear wear-resistant copper sleeve (10) are provided with rectangular balance grooves with a width-to-depth ratio of 1:

1. The number of rectangular balance grooves with a width-to-depth ratio of 1:1 on the inner surfaces of the front wear-resistant copper sleeve (21) and the rear wear-resistant copper sleeve (10) is 3 to 6. The front wear-resistant copper sleeve (21) and the rear wear-resistant copper sleeve (10) are fitted with the valve core (1) with a small clearance. The front wear-resistant copper sleeve (21) and the rear wear-resistant copper sleeve (10) provide support for the repeated movement of the valve core (1).

5. A hydraulic energy absorber suitable for durability testing of full-power impact performance of hydraulic rock drills according to claim 1, characterized in that, The maximum inner diameter of the anti-reverse body (2) is 0.4 mm larger than the maximum outer diameter of the valve core (1) but not more than 1 mm. The left inner diameter of the anti-reverse body (2) is 0.4 mm larger than the leftmost outer diameter of the valve core (1) but not more than 0.8 mm.

6. A hydraulic energy absorber suitable for durability testing of full-power impact performance of hydraulic rock drills according to claim 1, characterized in that, The rear cover (13) has a small through hole with a diameter of 4 to 6 mm in the center to ensure the flow of gas and to verify whether the O-ring (14) and the step seal (14) are leaking oil.

7. A hydraulic energy absorber suitable for durability testing of full-power impact performance of hydraulic rock drills according to claim 1, characterized in that, The valve core (1) has a rectangular balance groove with a width-to-depth ratio of 1:

1. The number of rectangular balance grooves with a width-to-depth ratio of 1:1 in the valve core (1) is 3 to 6. The fit clearance between the rectangular balance groove section of the valve core (1) and the rear cylinder block sleeve (8) is 0.05 to 0.08 mm.

8. A hydraulic energy absorber suitable for durability testing of full-power impact performance of hydraulic rock drills according to claim 1, characterized in that, The relationship between the maximum inner diameter D2 of the anti-reverse body (2) and the maximum outer diameter d20 of the front cylinder (20) is that d20≥1.4D2.

9. A hydraulic energy absorber suitable for durability testing of full-power impact performance of hydraulic rock drills according to claim 1, characterized in that, The diameter of the inner hole on the right side of the side hole of the front cylinder block sleeve (18) is smaller than the diameter of the inner hole on the left side.

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