Multi-stage feeding device and drilling rig

Abstract

The present invention discloses a multi-stage feeding device and a drilling rig, wherein the multi-stage feeding device comprises: an outer cylinder, wherein a piston is arranged in the outer cylinder; a front-stage piston rod, wherein the front-stage piston rod is nested in the outer cylinder; a front-stage piston rod, wherein the front-stage piston rod is nested in the front-stage piston rod; a rear-stage piston rod, wherein the rear-stage piston rod is nested in the outer cylinder; and a rear-stage piston rod, wherein the rear-stage piston rod is nested in the rear-stage piston rod; a first oil passage and a second oil passage are arranged on the piston, wherein the first oil passage connects the front-stage oil chamber and the rear-stage oil chamber, and the second oil passage connects the rear-stage oil chamber and the front-stage oil chamber. The device and the drilling rig adopt a single-acting oil cylinder structure to realize multi-stage telescopic driving action. Compared with the structure in the prior art that usually requires multiple action sources to realize multi-stage driving, the overall structure is simple, the control is convenient, stable, and the reliability is high; and the installation size is small, which can better adapt to different working scenarios.

Description

Technical Field

[0001] The invention belongs to the technical field of drilling equipment, and in particular relates to a multi-stage feeding device and a drilling rig. Background Art

[0002] In geological drilling operations, the drill tool is driven forward or backward by the drill tool feed device to achieve the forward push or pull of the drill tool. It is widely used in engineering geological surveys, solid mineral core drilling and other projects. It is particularly suitable for geological drilling and coring operations in railway and highway tunnels or deep mineral tunnels. It is suitable for drilling processes such as diamond rope coring and ordinary diamond rotary coring.

[0003] Existing drilling rig feed devices mostly use a one-stage double-acting cylinder direct drive or a cylinder chain speed mechanism drive. These structures often have the problem of short feed stroke or large size. Generally speaking, if a one-stage double-acting cylinder direct drive structure wants to achieve a long stroke, the cylinder size must be longer, resulting in a longer installation size. When the piston rod is fully extended, the cylinder body will extend beyond the drill rig, resulting in poor stability and significant restrictions on the use space. The push-pull force of the cylinder chain speed mechanism is generally small, and there is a problem that the push force is less than the pull-out force. The drilling push-pull force is only half of the cylinder's own push-pull force. If the push-pull force is to be increased, the cylinder diameter needs to be increased, which will significantly increase the weight of the entire mechanism. In addition, the chain roller structure it uses is complex and has poor stability. Summary of the Invention

[0004] The object of the present invention is to provide a multi-stage feeding device adopting a single-acting multi-stage composite oil cylinder structure and a drilling rig adopting such a multi-stage feeding device, so as to solve the above-mentioned technical problems existing in the prior art.

[0005] The present invention is achieved through the following technical solutions:

[0006] Multi-stage feeding device, comprising:

[0007] an outer cylinder, wherein a piston is disposed in the outer cylinder;

[0008] A previous stage piston rod, which is nested in the outer cylinder, has one end connected to one end of the piston, and the other end extends out of the outer cylinder, forming a closed previous stage oil chamber between the outer cylinder, the previous stage piston rod, and the piston;

[0009] A front secondary piston rod, wherein the front secondary piston rod is nested in the front primary piston rod, and the front secondary piston rod and the front secondary piston rod are slidably connected to each other, forming a front secondary oil chamber between the front primary piston rod, the front secondary piston rod and the piston, and a front oil channel is provided in the front secondary piston rod, one end of the front oil channel is connected to the front secondary oil chamber, and the other end is provided with a front oil port for connecting to an external oil source;

[0010] A rear-stage piston rod, which is nested in the outer cylinder, one end of which is connected to the other end of the piston relative to the previous-stage piston rod, and the other end of which extends out of the outer cylinder, forming a closed rear-stage oil chamber between the outer cylinder, the rear-stage piston rod and the piston;

[0011] A rear secondary piston rod, wherein the rear secondary piston rod is nested in the rear primary piston rod, and the rear secondary piston rod is slidably connected to the rear primary piston rod, forming a rear secondary oil chamber between the rear primary piston rod, the rear secondary piston rod and the piston, and a rear oil channel is provided in the rear secondary piston rod, one end of the rear oil channel is connected to the rear secondary oil chamber, and the other end is provided with a rear oil port for connecting to an external oil source;

[0012] The piston is provided with a first oil passage and a second oil passage, wherein the first oil passage is connected to the front secondary oil chamber and the rear primary oil chamber, and the second oil passage is connected to the rear secondary oil chamber and the front primary oil chamber.

[0013] As a further improvement of the above technical solution, a first-level guide sleeve is provided at both ends of the outer cylinder, between the outer cylinder and the previous-level piston rod, and between the outer cylinder and the next-level piston rod. The first-level guide sleeve is slidably fitted with the previous-level piston rod and the next-level piston rod, and a sealing assembly is provided between the first-level guide sleeve and the previous-level piston rod and the next-level piston rod.

[0014] As a further improvement of the above technical solution, one end of the front secondary piston rod is provided with a front sliding part that cooperates with the previous stage piston rod, the front sliding part and the previous stage piston rod are slidably matched, and a sealing assembly is provided between the front sliding part and the previous stage piston rod.

[0015] As a further improvement of the above technical solution, a front-secondary guide sleeve is provided at one end of the front-secondary piston rod between the front-secondary piston rod and the front-secondary piston rod, and the front-secondary guide sleeve is slidably fitted with the front-secondary piston rod.

[0016] As a further improvement of the above technical solution, the front-stage guide sleeve is provided with a guide component and a dustproof component, and the front-stage guide sleeve is provided with an air channel connecting the interior of the front-stage piston rod with the outside world.

[0017] As a further improvement of the above technical solution, one end of the rear secondary piston rod is provided with a rear sliding part that cooperates with the rear primary piston rod, the rear sliding part and the rear primary piston rod are slidably matched, and a sealing assembly is provided between the rear sliding part and the rear primary piston rod.

[0018] As a further improvement of the above technical solution, a rear-stage guide sleeve is provided at one end of the rear-stage piston rod between the rear-stage piston rod and the rear-stage piston rod, and the rear-stage guide sleeve is slidably fitted with the rear-stage piston rod.

[0019] As a further improvement of the above technical solution, the rear secondary guide sleeve is provided with a guide component and a dustproof component, and the rear secondary guide sleeve is provided with an air channel connecting the interior of the rear stage piston rod with the outside world.

[0020] As a further improvement of the above technical solution, the piston includes a piston portion and connecting portions provided at both ends of the piston portion, and a sealing assembly is provided between the piston portion and the outer cylinder;

[0021] The front-stage piston rod and the rear-stage piston rod are respectively connected to the connecting part, forming the front-stage oil chamber between the piston part, the outer cylinder and the front-stage piston rod, and forming the rear-stage oil chamber between the piston part, the outer cylinder and the rear-stage piston rod.

[0022] On the other hand, the present invention further provides a drilling rig using a multi-stage feeding device, comprising a drill frame, wherein a front secondary piston rod and a rear secondary piston rod of the multi-stage feeding device are respectively connected to the drill frame.

[0023] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0024] 1) A single-acting oil cylinder structure is used to realize the multi-stage telescopic drive action of the device. Compared with the prior art structure that usually requires multiple action sources to realize multi-stage drive, the overall structure of this device is simple, easy to control, stable, and highly reliable.

[0025] 2) The entire device is structurally optimized to achieve single-acting multi-stage drive while having a small installation size. This reduces the overall size of the device while ensuring a long stroke, allowing it to better adapt to different working scenarios.

[0026] 3) By optimizing the structure of the device, the effective area of each level of cylinder can be reasonably configured according to needs. In this way, the thrust and pulling force generated during the operation of the device can be adjusted by simply adjusting the proportional relationship between the effective areas of the cylinders at each level. In addition, the internal oil circuit structure of the device is simple, and the movement speed during the operation of the device can be effectively controlled, which can effectively solve the problems of unequal push and pull forces of multi-stage cylinders in traditional structures and jumps in movement speed during operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings in the embodiments will be briefly introduced below. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0028] Figure 1 It is a schematic structural diagram of the multi-stage feeding device in the present invention.

[0029] Figure 2 This is a schematic diagram of the drilling rig structure using a multi-stage feeding device in the present invention.

[0030] Figure 3 This is a structural front view of an embodiment of the drilling rig in the present invention.

[0031] Figure 4 This is a structural cross-sectional view of the multi-stage feeding device of the present invention installed on the drilling rig.

[0032] Figure 5 for Figure 4 Partial schematic diagram at point A in the middle.

[0033] Figure 6 for Figure 4 Partial schematic diagram at point B in the middle.

[0034] Figure 7 This is a structural schematic diagram of the outer cylinder of the multi-stage feeding device of the present invention moving downward to the maximum stroke state.

[0035] Figure 8 for Figure 7 Partial schematic diagram at point C in the middle.

[0036] Figure 9 It is a schematic diagram of the piston structure in the multi-stage feeding device of the present invention.

[0037] Figure 10 It is a schematic diagram of the structure of the front secondary guide sleeve / rear secondary guide sleeve in the multi-stage feeding device of the present invention.

[0038] in:

[0039] 10. Drilling rack;

[0040] 201, outer cylinder, 202, front-stage piston rod, 203, front-stage piston rod, 231, front sliding portion, 204, rear-stage piston rod, 205, rear-stage piston rod, 251, rear sliding portion, 206, piston, 261, piston portion, 262, connecting portion, 207, front-stage guide sleeve, 208, front-stage guide sleeve, 209, air passage, 211, rear-stage guide sleeve, 214, rear-stage guide sleeve;

[0041] 301, front first-stage oil chamber, 302, front second-stage oil chamber, 303, front oil channel, 304, front oil port, 305, rear first-stage oil chamber, 306, rear second-stage oil chamber, 307, rear oil channel, 308, rear oil port, 309, first oil channel, 310, second oil channel. DETAILED DESCRIPTION

[0042] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments.

[0043] Example 1

[0044] Reference Figure 1 and 4 The multi-stage feeding device in this embodiment includes:

[0045] The outer cylinder 201 is provided with a piston 206, which is slidably fitted with the outer cylinder 201 and can perform piston motion in the outer cylinder. Figure 5 and 9 The piston 206 in this embodiment includes a piston portion 261 and connecting portions 262 disposed at both ends of the piston portion. A sealing assembly is provided on the piston portion 263, which separates the outer cylinder into two independent front and rear chambers. The sealing assembly provided on the piston portion can be a combination of a PTFE guide ring, a piston grid ring, or the like, to achieve both sealing and motion guidance.

[0046] Previous stage piston rod 202; the previous stage piston rod 202 is a hollow structural component, the previous stage piston rod 202 is nested in the outer cylinder 201, one end of the previous stage piston rod 202 is connected to the connecting part 262 of the piston 206, and is fixedly connected to the connecting part 262 by a thread, and the other end extends to the outside of the outer cylinder 201.

[0047] A first-stage guide sleeve is provided at the end of the outer cylinder 201 between the outer cylinder and the previous-stage piston rod. The first-stage guide sleeve is the previous-stage guide sleeve 207, which can be fixedly connected to the end of the outer cylinder 201 by a thread. The previous-stage guide sleeve 207 and the previous-stage piston rod 202 are slidably matched. A sealing assembly is provided between the previous-stage guide sleeve 207 and the previous-stage piston rod 202. At this time, a closed previous-stage oil chamber 301 is formed between the piston portion 261 of the piston, the inner wall of the outer cylinder 201, the outer wall of the previous-stage piston rod 202 and the previous-stage guide sleeve 207. Here, the previous-stage guide sleeve not only forms a seal between the outer cylinder and the previous-stage piston rod, but also serves to limit the movement position of the outer cylinder. The sealing assembly provided between the previous-stage guide sleeve 207 and the previous-stage piston rod 202 can adopt a combination of a polytetrafluoroethylene guide ring, an O-ring, a Ster seal, a Y-ring, a dust ring, etc. to achieve the functions of sealing and motion guiding.

[0048] The front secondary piston rod 203; the front secondary piston rod 203 is nested in the front secondary piston rod 202, and a movable fitting connection is formed between the front secondary piston rod 203 and the front secondary piston rod 202; specifically, as a feasible embodiment, a front sliding portion 231 that cooperates with the cylinder body of the front primary piston rod 202 is provided at one end of the front secondary piston rod 203, and the front sliding portion 231 and the front primary piston rod 202 are slidably fitted, and a sealing assembly is provided between the front sliding portion 231 and the front primary piston rod 202. At this time, a front secondary oil chamber 302 is formed between the piston 206, the front sliding portion 231 of the front secondary piston rod, and the inner wall of the front primary piston rod 202. A front oil channel 303 is provided in the front secondary piston rod 203, and the front oil channel 303 is provided as a blind hole structure. One end of the front oil channel 303 is connected to the front secondary oil chamber 302, and a front oil port 304 for connecting to an external oil source is provided on the other end of the front oil channel 303 on the front secondary piston rod 203.

[0049] A front-secondary guide sleeve 208 is provided at one end of the front-stage piston rod 202 between the front-stage piston rod and the front-secondary piston rod. The front-secondary guide sleeve 208 is in sliding cooperation with the front-secondary piston rod 203, guiding the front-secondary piston rod when it moves inside the front-stage piston rod, and at the same time limiting the movement position of the front-stage piston rod. A guide assembly and a dustproof assembly are provided on the front-secondary guide sleeve 208, which play the role of guidance and dustproof; the guide assembly here can adopt a secondary PTFE guide ring, and the dustproof assembly and a secondary dustproof ring can adopt a secondary dustproof ring. An air channel is provided on the front-secondary guide sleeve 208 to connect the internal space formed between the front-stage piston rod and the front-secondary piston rod with the outside world, so as to ensure the stable movement between the front-secondary piston rod and the front-stage piston rod, such as Figure 6 and 10 .

[0050] At this time, a group of multi-stage oil cylinders is formed between the first-stage piston rod 202 , the first-stage piston rod 203 and the outer cylinder 201 .

[0051] Correspondingly, the multi-stage feeding device also includes another set of multi-stage cylinders, including:

[0052] The rear-stage piston rod 204; the rear-stage piston rod 204 is a hollow structural component, and the rear-stage piston rod 204 is nested in the outer cylinder 201. One end of the rear-stage piston rod 204 is connected to the connecting part 262 at the other end of the piston, and is fixedly connected to the connecting part 262 by a thread, and the other end extends to the outside of the outer cylinder 201.

[0053] At the end of the outer cylinder 201, a first-level guide sleeve is provided between the outer cylinder 201 and the rear-stage piston rod 204. The first-level guide sleeve is a rear-stage guide sleeve 211, which can be fixedly connected to the end of the outer cylinder 201 by threads. The rear-stage guide sleeve 211 and the rear-stage piston rod 210 are slidably fitted together. A sealing assembly is provided between the rear-stage guide sleeve 211 and the rear-stage piston rod 204. At this time, a closed rear-stage oil chamber 305 is formed between the piston portion 261 of the piston, the inner wall of the outer cylinder 201, the outer wall of the rear-stage piston rod 204 and the rear-stage guide sleeve 211. Here, the rear-stage guide sleeve not only forms a seal between the outer cylinder and the rear-stage piston rod, but also limits the movement position of the outer cylinder. The sealing assembly provided here can adopt the same structure as the sealing assembly used by the previous guide sleeve.

[0054] The rear secondary piston rod 205 is nested within the rear primary piston rod 204, forming a movable connection between the rear secondary piston rod 205 and the rear primary piston rod 204. Specifically, a rear sliding portion 251 is provided at one end of the rear secondary piston rod 205, which cooperates with the cylinder body of the rear primary piston rod 204. The rear sliding portion 251 and the rear primary piston rod 204 are slidably engaged, and a sealing assembly is provided between the rear sliding portion 251 and the rear primary piston rod 204. At this time, a rear secondary oil chamber 306 is formed between the piston 206, the rear sliding portion 251 of the rear secondary piston rod, and the inner wall of the rear primary piston rod 204. A rear oil passage 307 is provided within the rear secondary piston rod 205. The rear oil passage 307 is configured as a blind hole structure, with one end of the rear oil passage 307 communicating with the rear secondary oil chamber 306. A rear oil port 308 for connecting to an external oil source is provided at the other end of the rear oil passage on the rear secondary piston rod 203.

[0055] Similarly, a rear secondary guide sleeve 214 is provided at one end of the rear piston rod 210 between the rear piston rod and the rear secondary piston rod. The rear secondary guide sleeve 214 slides with the rear secondary piston rod 212 to guide the rear secondary piston rod as it moves within the rear piston rod and to limit the movement position of the rear piston rod. A guide assembly and a dustproof assembly are provided on the rear secondary guide sleeve 214 to guide and prevent dust. The guide assembly can be a secondary PTFE guide ring, and the dustproof assembly can be a secondary dustproof ring. An air channel 209 is provided on the rear secondary guide sleeve 214 to connect the internal space formed between the rear piston rod and the rear secondary piston rod with the outside world, ensuring stable movement between the rear secondary piston rod and the rear piston rod.

[0056] At this time, another set of multi-stage oil cylinders is formed between the rear first-stage piston rod 204 , the rear second-stage piston rod 205 and the outer cylinder 201 .

[0057] A first oil passage 309 and a second oil passage 310 are provided on the piston 206 . The first oil passage 309 connects the front secondary oil chamber 302 and the rear primary oil chamber 305 . The second oil passage 310 connects the rear secondary oil chamber 305 and the front primary oil chamber 302 .

[0058] At this time, the two sets of multi-stage oil cylinders arranged opposite to each other in the outer cylinder share one outer cylinder to form a single-acting multi-stage compound oil cylinder. The action process is as follows (take the front two-stage piston rod and the rear two-stage piston rod in the fixed state as an example, at this time the piston is in the middle state, refer to Figure 4 shown):

[0059] The upward movement of the outer cylinder:

[0060] The high-pressure oil enters the front secondary oil chamber from the front oil port through the front oil channel, and then enters the rear secondary oil chamber through the first oil channel. At this time, the outer cylinder is pushed upward by the action of the high-pressure oil. When the front-stage guide sleeve moves to the piston position and contacts the piston, the front-stage oil chamber is filled with high-pressure oil. Under the action of the high-pressure oil, the outer cylinder, the front-stage piston rod and the rear-stage piston rod are pushed upward together until the front-stage guide sleeve contacts the front sliding part of the front-stage piston rod. At this time, the outer cylinder moves upward to the maximum stroke. In this process, the oil in the front-stage oil chamber is squeezed into the rear-stage oil chamber through the second oil channel, and the oil in the rear-stage oil chamber is discharged through the rear oil channel and the rear oil port in turn.

[0061] Downward movement of the outer cylinder:

[0062] The high-pressure oil enters the rear secondary oil chamber from the rear oil port through the rear oil channel, and then enters the front-stage oil chamber through the second oil channel. At this time, the outer cylinder is pushed downward by the action of the high-pressure oil. When the rear-stage guide sleeve moves to the piston position and contacts the piston, the rear-stage oil chamber is filled with high-pressure oil. Under the action of the high-pressure oil, the outer cylinder, the rear-stage piston rod and the front-stage piston rod are pushed downward together until the rear-stage guide sleeve contacts the rear sliding part of the rear-stage piston rod. At this time, the outer cylinder moves downward to the maximum stroke, such as Figure 7 and 8 As shown; in this process, the oil in the rear-stage oil chamber is squeezed into the front-stage oil chamber through the first oil channel, and the oil in the front-stage oil chamber is discharged through the front oil channel and the front oil port in turn.

[0063] It can be seen from the above working process that the multi-stage feeding device optimizes the structure of each level and the oil channel. It only needs to set oil ports connected to the external oil source on the front secondary piston rod and the rear secondary piston rod. The oil inlet and oil outlet are controlled from the oil ports to realize the drive control of the external cylinder and achieve the effect of a single-acting multi-stage oil cylinder, making the overall structure of the device simpler, more convenient to control, and with better stability.

[0064] At the same time, since the two groups of multi-stage oil cylinders share one outer cylinder, during operation, when the piston rod of one group of multi-stage oil cylinders extends, the piston rod of the other group of multi-stage oil cylinders retracts into the inner part of the outer cylinder (refer to Figure 7 ), thereby greatly shortening the overall size of the multi-stage feeding device, making it better suitable for various working scenarios.

[0065] Moreover, by matching the piston rod and cylinder diameter sizes at each level, it is easy to make the effective pressure area of the oil chamber at each level equal. This can make the thrust and pulling force generated by the extension and contraction at each level equal, and can make the movement speed during the action of each level uniform, which effectively solves the problem of speed jump during movement.

[0066] Example 2

[0067] like Figure 2 and 3 As shown, this embodiment shows a drilling rig using the above-mentioned multi-stage feed device, including a drill frame 10. The multi-stage feed device is disposed within the drill frame 10, wherein the front secondary piston rod 203 and the rear secondary piston rod 212 of the multi-stage feed device are respectively connected to the drill frame 10. The front secondary piston rod and the rear secondary piston rod can be connected to both ends of the drill frame using pins.

[0068] The drilling rig power head is connected to the outer cylinder of the multi-stage feed device. When the multi-stage feed device is in operation, the drilling rig power head is driven to move through the outer cylinder. The outer cylinder is driven jointly by two groups of multi-stage oil cylinders composed of two-stage piston rods, thereby increasing the movement stroke of the outer cylinder and the movement range of the drilling rig power head. In addition, the two groups of multi-stage oil cylinders share one outer cylinder. During operation, when one group of multi-stage oil cylinders is extended, the other group of multi-stage oil cylinders is retracted into the outer cylinder, thereby reducing the overall size of the drilling rig.

[0069] The operation process of the drilling head in the drilling rig is similar to the operation process of the outer cylinder, which will not be repeated here. During the process of driving the drilling head, the multi-stage feed device and the drilling head are always within the range of the drill frame, making the operation of the drilling rig very stable.

[0070] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. used to indicate the orientation or position relationship are based on the orientation or position relationship shown in the accompanying drawings, or are the orientation or position relationship in which the product of the invention is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they should not be understood as limiting the present invention.

[0071] Furthermore, the use of terms such as "horizontal" and "vertical" in the description of the present invention does not necessarily imply that the component must be absolutely horizontal or suspended, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical" and does not mean that the structure must be completely horizontal, but rather that it can be slightly tilted.

[0072] It should also be noted that, in the description of the present invention, unless otherwise expressly specified or limited, the terms "disposed," "installed," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention in specific contexts.

[0073] The above description is merely a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification or change made to the above embodiment based on the technical essence of the present invention shall fall within the scope of protection of the present invention.

Claims

1. Multi-stage feeding device, characterized in that, include: an outer cylinder, wherein a piston is disposed in the outer cylinder; A previous stage piston rod, which is nested in the outer cylinder, has one end connected to one end of the piston, and the other end extends out of the outer cylinder, forming a closed previous stage oil chamber between the outer cylinder, the previous stage piston rod, and the piston; A front secondary piston rod, wherein the front secondary piston rod is nested in the front primary piston rod, and the front secondary piston rod and the front secondary piston rod are slidably connected to each other, forming a front secondary oil chamber between the front primary piston rod, the front secondary piston rod and the piston, and a front oil channel is provided in the front secondary piston rod, one end of the front oil channel is connected to the front secondary oil chamber, and the other end is provided with a front oil port for connecting to an external oil source; A rear-stage piston rod, which is nested in the outer cylinder, one end of which is connected to the other end of the piston relative to the previous-stage piston rod, and the other end of which extends out of the outer cylinder, forming a closed rear-stage oil chamber between the outer cylinder, the rear-stage piston rod and the piston; A rear secondary piston rod, wherein the rear secondary piston rod is nested in the rear primary piston rod, and the rear secondary piston rod is slidably connected to the rear primary piston rod, forming a rear secondary oil chamber between the rear primary piston rod, the rear secondary piston rod and the piston, and a rear oil channel is provided in the rear secondary piston rod, one end of the rear oil channel is connected to the rear secondary oil chamber, and the other end is provided with a rear oil port for connecting to an external oil source; The piston is provided with a first oil passage and a second oil passage, the first oil passage is connected to the front secondary oil chamber and the rear primary oil chamber, and the second oil passage is connected to the rear secondary oil chamber and the front primary oil chamber; A first-stage guide sleeve is provided at both ends of the outer cylinder, between the outer cylinder and the previous stage piston rod, and between the outer cylinder and the next stage piston rod. The first-stage guide sleeve is slidably fitted with the previous stage piston rod and the next stage piston rod, and a sealing assembly is provided between the first-stage guide sleeve and the previous stage piston rod and the next stage piston rod; One end of the front secondary piston rod is provided with a front sliding portion that cooperates with the previous stage piston rod. The front sliding portion and the previous stage piston rod are slidably matched, and a sealing component is provided between the front sliding portion and the previous stage piston rod.

2. The multi-stage feeding device according to claim 1, characterized in that: A front-secondary guide sleeve is provided at one end of the front-stage piston rod between the front-stage piston rod and the front-secondary piston rod, and the front-secondary guide sleeve is slidably fitted with the front-secondary piston rod.

3. The multi-stage feeding device according to claim 2, characterized in that: The front second-stage guide sleeve is provided with a guide component and a dustproof component, and the front second-stage guide sleeve is provided with an air passage connecting the interior of the front-stage piston rod with the outside world.

4. The multi-stage feeding device according to claim 1, characterized in that: One end of the rear secondary piston rod is provided with a rear sliding part that cooperates with the rear primary piston rod. The rear sliding part and the rear primary piston rod are slidably matched, and a sealing component is provided between the rear sliding part and the rear primary piston rod.

5. The multi-stage feeding device according to claim 1 or 4, characterized in that: A rear secondary guide sleeve is provided at one end of the rear primary piston rod between the rear primary piston rod and the rear secondary piston rod, and the rear secondary guide sleeve is slidably fitted with the rear secondary piston rod.

6. The multi-stage feeding device according to claim 5, characterized in that: The rear secondary guide sleeve is provided with a guide component and a dustproof component, and the rear secondary guide sleeve is provided with an air passage connecting the interior of the rear stage piston rod with the outside world.

7. The multi-stage feeding device according to claim 1, characterized in that: The piston comprises a piston portion and connecting portions provided at both ends of the piston portion, and a sealing assembly is provided between the piston portion and the outer cylinder; The front-stage piston rod and the rear-stage piston rod are respectively connected to the connecting part, forming the front-stage oil chamber between the piston part, the outer cylinder and the front-stage piston rod, and forming the rear-stage oil chamber between the piston part, the outer cylinder and the rear-stage piston rod.

8. A drilling rig using the multi-stage feeding device according to any one of claims 1 to 7, characterized in that: The multi-stage feeding device comprises a drilling frame, and a front secondary piston rod and a rear secondary piston rod of the multi-stage feeding device are respectively connected to the drilling frame.

Images