Percussion piston reversing structure of hydraulic down-the-hole drill

Abstract

The invention discloses an impact piston reversing structure of a hydraulic down-the-hole drill, and relates to the technical field of piston reversing structures. The impact piston is arranged in the circle center hole of the shell in a sliding mode, a concave groove is formed in the top of the shell, a longer sealing face is obtained through the structural form of the large lifting pin and the small lifting pin, the sealing effect is remarkably improved, lifting pin oil holes do not make direct contact with the sliding surface of a valve element, and inner leakage paths are structurally reduced; meanwhile, the oil passing hole diameter of the lifting pin is obviously larger than that of a traditional signal hole, the oil impurity blocking risk is greatly reduced, and the reliability of the system under the severe working condition is enhanced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of piston reversing structure, and particularly relates to a hydraulic down-the-hole drill impact piston reversing structure. BACKGROUND

[0002] The prior art realizes hydraulic piston reversing mainly by converting the piston position or motion state into a hydraulic pressure signal through a signal hole, feeding back to both ends of a reversing valve, driving the reversing valve to switch the oil path direction, so as to realize automatic reciprocating motion of the piston.

[0003] The prior art realizes hydraulic piston reversing mainly by converting the piston position or motion state into a hydraulic pressure signal through a signal hole, feeding back to both ends of a reversing valve, driving the reversing valve to switch the oil path direction, so as to realize automatic reciprocating motion of the piston.

[0004] Disadvantages of using a signal hole: 1. High position accuracy requirement The position accuracy requirement must be matched with the piston stroke, otherwise the reversing is too early or too late, which affects the efficiency and even damages the equipment. 2. Small hole diameter The hole diameter is usually 0.5-2 mm, which is easy to be blocked by oil impurities, and the hydraulic oil needs to be kept clean. 3. The movement of the reversing valve is realized by relying on the pressure difference of the signal hole, so the sealing requirements of the front and rear cavities of the reversing valve are extremely high. SUMMARY

[0005] Therefore, in order to solve the above problems, the present application provides a hydraulic down-the-hole drill impact piston reversing structure.

[0006] The present application is realized by constructing a hydraulic down-the-hole drill impact piston reversing structure, which comprises an impact piston; the impact piston is slidably arranged in the center hole of a shell, and a concave groove is arranged at the top of the shell; A gasket and a first U-shaped sealing ring and a gasket are arranged in the concave groove of the top of the shell from top to bottom, and the center holes of the gasket and the first U-shaped sealing ring and the gasket are slidably connected with the top side shaft body of the impact piston; an automatic valve body for flow guiding is fixedly arranged in the shell; a small top pin is slidably arranged in the flow channel of the automatic valve body; an automatic valve core is arranged on the annular groove of the inner side of the automatic valve body, and the upper and lower sides of the valve body on the side of the automatic valve core are respectively extruded with the small top pin and the bottom of the large top pin; the large top pin is slidably arranged in the sliding groove in the flow cylinder, and the bottom of the flow cylinder is fixedly blocked with a sealing seat; the flow cylinder and the sealing seat are sealingly installed in the inner part of the outer cylinder, and the top of the outer cylinder is sealingly installed with the shell; a second U-shaped sealing ring with sealing function is press-fitted between the flow cylinder and the sealing seat, and a dustproof ring with dustproof function is fixedly installed in the middle step of the sealing seat; the center holes of the second U-shaped sealing ring and the dustproof ring are slidably connected with the bottom side shaft body of the impact piston.

[0007] Preferably, a high-pressure oil cavity is formed between the housing inner space and the automatic valve body, and an oil inlet is arranged on the side of the housing and communicates with the high-pressure oil cavity.

[0008] Preferably, an upper cavity is formed between the impact piston and the automatic valve core inner space.

[0009] Preferably, a plurality of steps on the impact piston shaft body and the inner grooves of the flow cylinder form, from top to bottom, a first oil groove, a second oil groove, a lower cavity, a buffer groove and a third oil groove.

[0010] Preferably, a low-pressure oil passage is arranged on the left side of the flow cylinder, a high-pressure oil passage is arranged on the right side of the flow cylinder and communicates with the high-pressure oil cavity in the housing, the low-pressure oil passage communicates with the first oil groove and the third oil groove respectively, and the high-pressure oil passage communicates with the second oil groove and the lower cavity respectively.

[0011] Preferably, the small top pin and the large top pin have guide sections with different diameters and are coaxially arranged in the corresponding sliding grooves of the automatic valve body and the flow cylinder, the lower end surface of the small top pin is in contact with the upper valve body of the automatic valve core, the upper end surface of the large top pin is in contact with the lower valve body of the automatic valve core, and a bidirectional pushing structure is formed.

[0012] Preferably, an axially extending buffer groove is arranged on the inner wall of the flow cylinder, the buffer groove cooperates with the lower boss of the impact piston before the piston descends to the lower dead point, and a hydraulic damping buffer structure is formed.

[0013] Preferably, the first U-shaped sealing ring and the second U-shaped sealing ring are arranged at both ends of the up-down movement stroke of the impact piston, and the sealing lips of the two are both directed to the high-pressure side, forming a bidirectional pressure activated sealing structure.

[0014] The present application has the following advantages: the present application provides a hydraulic down-the-hole drill impact piston reversing structure by improvement, compared with the same type of equipment, has the following improvements: The hydraulic down-the-hole drill impact piston reversing structure provided by the present application has a longer sealing surface through the structure of the large and small top pins, significantly improves the sealing effect, and the top pin oil hole does not directly contact the valve core sliding surface, thereby reducing the internal leakage path from the structure; at the same time, the diameter of the top pin oil hole is significantly larger than that of the traditional signal hole, which greatly reduces the risk of oil impurities blockage and enhances the reliability of the system in harsh working conditions. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 is a structural schematic diagram of the present application; Figure 2 is a piston lower dead point oil passage diagram of the present application; Figure 3 is a piston lower dead point reversing action diagram of the present application; Figure 4 is a piston top dead center oil passage diagram of the present application; Figure 5 is a piston top dead center reversing action diagram of the present application.

[0016] Wherein: impact piston-1, shell-2, automatic valve body-3, small top pin-4, automatic valve core-5, large top pin-6, outer cylinder-7, flow cylinder-8, sealing seat-9, gasket-10, first U-shaped sealing ring-11, gasket-12, second U-shaped sealing ring-13, dust ring-14. DETAILED DESCRIPTION

[0017] The following description will be made in connection with the accompanying drawings, which are meant to illustrate and not to limit the present application. Figures 1-5 The principles and advantages of the present application will be described in detail, and the examples are used to explain the present application, not to limit the scope of the present application. In the following paragraphs, the present application will be described in more detail with reference to the accompanying drawings. It should be noted that the drawings are very simplified and non-precise proportions are used, only to facilitate, clear and assist the purpose of describing the embodiments of the present application.

[0018] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", "third" are only for the purpose of description, and cannot be understood as indicating or implying relative importance.

[0019] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection", "setting" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be connected inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances. The embodiments of the present application will be described below according to the overall structure of the present application.

[0020] Please refer to Figures 1-5The hydraulic down-the-hole drill impact piston reversing structure of the present application comprises an impact piston 1; the impact piston 1 is slidably arranged in the center hole of a shell 2, and the top of the shell 2 is provided with a concave groove; a gasket 10, a first U-shaped sealing ring 11 and a gasket 12 are arranged in the concave groove of the top of the shell 2 from top to bottom, and the center holes of the gasket 10, the first U-shaped sealing ring 11 and the gasket 12 are slidably connected with the shaft body of the top side of the impact piston 1; an automatic valve body 3 for flow guiding is fixedly arranged in the shell 2; a small top pin 4 is slidably arranged in the flow channel of the automatic valve body 3; an automatic valve core 5 is arranged on the annular groove of the inner side of the automatic valve body 3, and the upper and lower sides of the valve body on the side of the automatic valve core 5 are respectively extruded by the small top pin 4 and the bottom of a large top pin 6; the large top pin 6 is slidably arranged in the sliding groove in the flow cylinder 8, and the bottom of the flow cylinder 8 is fixedly blocked with a sealing seat 9; the flow cylinder 8 and the sealing seat 9 are sealingly installed in the outer cylinder 7, and the top of the outer cylinder 7 is sealingly installed with the shell 2; a second U-shaped sealing ring 13 with sealing function is press-fitted between the flow cylinder 8 and the sealing seat 9, and a dustproof ring 14 with dustproof function is fixedly installed in the middle step of the sealing seat 9; the center holes of the second U-shaped sealing ring 13 and the dustproof ring 14 are slidably connected with the shaft body of the bottom side of the impact piston 1.

[0021] A high-pressure oil cavity a1 is formed between the inner space of the shell 2 and the automatic valve body 3, and an oil inlet a2 is formed in the side of the shell 2 and is in communication with the high-pressure oil cavity a1.

[0022] The inner space of the impact piston 1 and the automatic valve core 5 forms an upper cavity a4.

[0023] The shaft body of the impact piston 1 and the inner groove of the flow cylinder 8 form a first oil groove b1, a second oil groove b2, a lower cavity a5, a buffer groove b3 and a third oil groove b4 from top to bottom.

[0024] A low-pressure oil passage c1 is formed in the left side of the flow cylinder 8; a high-pressure oil passage c2 is formed in the right side of the flow cylinder 8 and is in communication with the high-pressure oil cavity a1 in the shell 2, and the low-pressure oil passage c1 is in communication with the first oil groove b1 and the third oil groove b4 respectively; the high-pressure oil passage c2 is in communication with the second oil groove b2 and the lower cavity a5 respectively.

[0025] The small top pin 4 and the large top pin 6 have different diameter guide sections and are coaxially arranged in the corresponding sliding grooves of the automatic valve body 3 and the flow cylinder 8, the lower end surface of the small top pin 4 is in contact with the upper valve body of the automatic valve core 5, and the upper end surface of the large top pin 6 is in contact with the lower valve body of the automatic valve core 5, forming a bidirectional pushing structure.

[0026] The inner wall of the flow cylinder 8 is provided with an axially extending buffer groove b3, which cooperates with the lower protrusion of the impact piston 1 before the piston goes down to the lower stop point, forming a hydraulic damping buffer structure.

[0027] The first U-shaped sealing ring 11 and the second U-shaped sealing ring 13 are respectively located at both ends of the vertical stroke of the impact piston 1, and the sealing lips of both face the high-pressure side, forming a bidirectional pressure-activated sealing structure.

[0028] The working principle of the hydraulic down-the-hole drill impact piston reversing structure described above is as follows: Step 1: After piston 1 completes its downward strike, it reaches the bottom dead center, triggering the return stroke and reversal; piston 1 completes one downward strike and is at its lowest point, as shown below. Figure 2 As shown, high-pressure oil enters the lower cavity a5 through high-pressure oil passage c2; simultaneously, the high-pressure oil enters the second oil groove b2 on the flow cylinder 8 and acts on the bottom of the top pin 6; as... Figure 3 As shown, the large top pin 6 moves upward under the action of oil pressure, lifting the automatic valve core 5 and switching it to the return position; after the valve core reverses, the upper chamber a4 is separated from the high-pressure oil and connected to the low-pressure oil circuit c1, so that high-pressure oil enters the lower chamber a5 of the piston and return oil flows through the upper chamber a4; under the action of the pressure difference between the upper and lower chambers, the piston 1 begins to move upward to achieve the return stroke; Step 2: Piston 1 moves upward under hydraulic drive, approaching top dead center; the movement of the piston 1 shoulder changes the connection between the oil grooves; such as... Figure 4 As shown, when piston 1 approaches top dead center, the second oil groove b2, which previously supplied oil to the large top pin 6, disconnects from the high-pressure oil circuit c2 and instead connects to the low-pressure oil circuit c1; this releases the pressure at the bottom of the large top pin 6, and its upward force pushing the valve core disappears; simultaneously, high-pressure oil acts on the top of the small top pin 4 through another oil passage; as shown... Figure 5 As shown, the small top pin 4 moves downward under the action of high pressure oil, pushing the automatic valve core 5 to move downward again to switch positions; the upper cavity a4 is connected to the high pressure oil circuit c2, and the lower cavity a5 is connected to the high pressure oil circuit c2. Step 3: High-speed downward impact and buffering of piston 1; High-pressure oil enters the upper cavity a4 of piston 1, and piston 1 obtains extremely high acceleration under the action of huge pressure difference, making downward impact motion; Piston 1 strikes the chisel at high speed, completing the impact work; At the end of the impact stroke, the boss at the lower end of piston 1 enters the specially set third oil groove b4 in the flow cylinder 8; The boss of piston 1 squeezes the hydraulic oil in the buffer groove b3, generating a strong throttling damping effect, so that the piston decelerates smoothly, effectively avoiding rigid impact and protecting the equipment.

[0029] This invention provides an improved hydraulic down-the-hole drill impact piston reversing structure. By using a combination of large and small top pins, a longer sealing surface is achieved, significantly improving the sealing effect. Furthermore, the top pin oil hole does not directly contact the valve core sliding surface, structurally reducing internal leakage paths. At the same time, the top pin oil passage diameter is significantly larger than that of traditional signal holes, greatly reducing the risk of oil impurities clogging the system and enhancing the reliability of the system under harsh operating conditions.

[0030] The above shows and describes the basic principles and main features of the present application and the advantages of the present application, and the standard parts used by the present application can be purchased from the market, and the special-shaped parts can be ordered according to the description and the drawings, the specific connection mode of each part adopts the conventional means such as bolt rivet, welding in the prior art, the mechanical, part and equipment adopt the conventional type in the prior art, and the circuit connection adopts the conventional connection mode in the prior art, which will not be described in detail here.

[0031] The above description of disclosed embodiments enables one of ordinary skill in the art to make or use the application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein can be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A hydraulic down-the-hole drill impact piston reversing structure, characterized in that: Includes an impact piston (1); the impact piston (1) is slidably disposed inside the central hole of the housing (2), and the top of the housing (2) is provided with a concave groove; The top groove of the housing (2) is provided with a gasket (10), a first U-shaped sealing ring (11), and a gasket (12) from top to bottom. The central holes of the gasket (10), the first U-shaped sealing ring (11), and the gasket (12) are all slidably connected to the top side shaft of the impact piston (1). An automatic valve body (3) for guiding flow is fixedly provided inside the housing (2). A small top pin (4) is slidably provided in the flow channel of the automatic valve body (3). An automatic valve core (5) is provided on the annular groove on the inner side of the automatic valve body (3). The upper and lower sides of the automatic valve core (5) are squeezed against the bottom of the small top pin (4) and the large top pin (6) respectively. The large top pin (6) is slidably disposed in the internal groove of the flow cylinder (8), and the bottom of the flow cylinder (8) is sealed and fixed with a sealing seat (9); the flow cylinder (8) and the sealing seat (9) are sealed and installed inside the outer cylinder (7), and the top of the outer cylinder (7) is sealed and installed with the housing (2); a second U-shaped sealing ring (13) with a sealing function is pressed between the flow cylinder (8) and the sealing seat (9), and a dustproof ring (14) with a dustproof function is fixedly installed in the middle step of the sealing seat (9); the center holes of the second U-shaped sealing ring (13) and the dustproof ring (14) are slidably connected to the bottom side shaft of the impact piston (1).

2. The hydraulic down-the-hole drill impact piston reversing structure according to claim 1, characterized in that: A high-pressure oil chamber (a1) is formed between the internal space of the housing (2) and the automatic valve body (3), and an oil inlet (a2) connected to the high-pressure oil chamber (a1) is provided on the side of the housing (2).

3. The hydraulic down-the-hole drill impact piston reversing structure according to claim 2, characterized in that: The internal space of the impact piston (1) and the automatic valve core (5) forms an upper cavity (a4).

4. The hydraulic down-the-hole drill impact piston reversing structure according to claim 3, characterized in that: The impact piston (1) shaft has multiple sets of steps and the internal groove of the flow cylinder (8) forming a first oil groove (b1), a second oil groove (b2), a lower cavity (a5), a buffer groove (b3) and a third oil groove (b4) from top to bottom.

5. The hydraulic down-the-hole drill impact piston reversing structure according to claim 4, characterized in that: A low-pressure oil passage (c1) is provided on the left side inside the flow cylinder (8); a high-pressure oil passage (c2) is provided on the right side inside the flow cylinder (8) and is connected to the high-pressure oil chamber (a1) inside the shell (2), and the low-pressure oil passage (c1) is connected to the first oil tank (b1) and the third oil tank (b4) respectively; the high-pressure oil passage (c2) is connected to the second oil tank (b2) and the lower cavity (a5) respectively.

6. The hydraulic down-the-hole drill impact piston reversing structure according to claim 5, characterized in that: The small top pin (4) and the large top pin (6) have guide sections with different diameters, and they are coaxially arranged in the corresponding slide grooves of the automatic valve body (3) and the flow cylinder (8). The lower end face of the small top pin (4) contacts the upper valve body of the automatic valve core (5), and the upper end face of the large top pin (6) contacts the lower valve body of the automatic valve core (5), forming a bidirectional pushing structure.

7. The hydraulic down-the-hole drill impact piston reversing structure according to claim 6, characterized in that: The inner wall of the flow cylinder (8) is provided with an axially extending buffer groove (b3). The buffer groove (b3) cooperates with the lower boss of the impact piston (1) before the piston moves down to the lower dead center to form a hydraulic damping buffer structure.

8. The hydraulic down-the-hole drill impact piston reversing structure according to claim 7, characterized in that: The first U-shaped sealing ring (11) and the second U-shaped sealing ring (13) are respectively set at both ends of the up and down stroke of the impact piston (1), and the sealing lips of both face the high pressure side, forming a bidirectional pressure-activated sealing structure.

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