A self-flushing drill pipe connection device

Abstract

The present invention relates to a self-flushing drill pipe connection device, belonging to the field of drilling tools. It includes an outer housing, in which a rotating shaft is rotatably arranged, and the rotating shaft is axially relatively fixed to the outer housing; a core column is arranged axially movably in the outer housing, a throttling channel is arranged in the core column, and flow channels communicated with the throttling channel are arranged on both the rotating shaft and the outer housing; the relative position of the core column in the outer housing is controlled by controlling the liquid pressure flowing through the throttling channel; a sewage discharge hole matched with the core column is formed on the outer housing, and the core column blocks or releases the sewage discharge hole during its movement. The present invention has the function of automatically switching between the self-flushing mode and the drilling mode of the drill pipe according to the flow rate change, realizes the continuity of the drill pipe cleaning and drilling operations, ensures the cleanliness of the newly added drill pipe interior, and greatly improves the service life of the hydraulic hammer.

Description

Technical Field

[0001] The invention belongs to the field of drilling tools and relates to a self-flushing drill rod connecting device. Background Art

[0002] Hydraulic hammers are currently widely used in hard rock drilling construction in coal mines due to their high drilling efficiency and good hole-forming quality. However, hydraulic hammers have extremely stringent requirements on the cleanliness of the drilling fluid. Each time a drill rod is added, the newly added drill rod carries a large amount of rock cuttings inside. The rock cuttings inside the drill rod follow the drilling fluid to the inside of the hydraulic hammer. The drilling fluid carrying rock cuttings causes the service life of the hydraulic hammer to be very short. According to statistics, the wear of the hydraulic hammer working underground for 6 hours is equivalent to the wear of working in clean water for 80 to 100 hours. The rock cuttings inside the newly added drill rod cause the hydraulic hammer to fail, which seriously affects the drilling efficiency and also causes a lot of economic losses. Summary of the invention

[0003] In view of this, in order to ensure the cleanliness of the inside of the newly added drill rod and improve the service life of the hydraulic hammer, the present invention provides a self-flushing drill rod connecting device, which can realize automatic switching between the drill rod cleaning mode and the drilling operation mode of the self-flushing drill rod connecting device through flow changes, thereby realizing automatic and efficient drill rod flushing, ensuring the internal cleanliness of the added drill rod, and greatly improving the service life of the hydraulic hammer.

[0004] In order to achieve the above object, the present invention provides the following technical solutions:

[0005] A self-flushing drill pipe connection device comprises an outer shell, a rotating shaft is rotatably arranged in the outer shell, and the rotating shaft is relatively fixed to the axial direction of the outer shell; a core column is arranged movably along the axial direction of the outer shell, a throttling channel is arranged in the core column, and a flow channel communicating with the throttling channel is provided on the rotating shaft and the outer shell; the relative position of the core column in the outer shell is controlled by controlling the pressure of the liquid flowing through the throttling channel; a sewage discharge hole cooperating with the core column is opened on the outer shell, and the core column blocks or releases the sewage discharge hole during its movement.

[0006] Optionally, a connecting sleeve for connecting to a water pipe is provided on one end of the rotating shaft away from the core column.

[0007] Optionally, the connecting sleeve is fixed to the rotating shaft via a connecting pin.

[0008] Optionally, the core column is provided with limiting units at two extreme positions in the rotating shaft.

[0009] Optionally, a return spring is provided at one end of the core column away from the rotating shaft.

[0010] Optionally, the rotating shaft is arranged in the housing through a first bearing and a second bearing, and the first bearing and the second bearing are arranged in the direction from outside to inside respectively.

[0011] Optionally, a bearing retaining ring is provided on the first bearing, and the bearing retaining ring presses the first bearing through an annular sealing ring.

[0012] Optionally, the annular sealing ring is pressed by a gland arranged on the housing.

[0013] Optionally, a core column sealing ring is provided between the core column and the housing.

[0014] Optionally, a retaining ring is provided between one side of the rotating shaft facing the core column and the housing.

[0015] The beneficial effects of the present invention are as follows:

[0016] The present invention has the function of automatically switching between the drill pipe self-flushing mode and the drilling mode according to the flow rate change, realizes the continuity of the drill pipe cleaning and drilling operations, ensures the cleanliness of the newly added drill pipe interior, and greatly improves the service life of the hydraulic hammer.

[0017] Other advantages, objectives and features of the present invention will be described to some extent in the subsequent specification, and to some extent, will be obvious to those skilled in the art based on the study of the following text, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the following specification. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be described in preferred detail below in conjunction with the drawings, wherein:

[0019] Figure 1 is a structural schematic diagram of the present invention;

[0020] Figure 2 is a structural schematic diagram of the core column at another stroke limit in the present invention.

[0021] Reference numerals: connecting pin 1, rotating shaft 2, gland 3, first bearing 4, rotating shaft sealing ring 5, housing 6, core column 7, core column sealing ring 8, return spring 9, retaining ring 10, second bearing 11, bearing retaining ring 12, annular sealing ring 13, connecting sleeve 14, sewage discharge hole 601, throttle channel 701. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] The following describes the embodiments of the present invention through specific examples. Those skilled in the art can easily understand the other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the drawings provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner. Without conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0023] Among them, the drawings are only for illustrative purposes, showing only schematic diagrams, not physical diagrams, and should not be construed as a limitation on the present invention; in order to better illustrate the embodiments of the present invention, some components in the drawings will be omitted, enlarged or reduced, which do not represent the dimensions of the actual product; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0024] In the drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components; in the description of the present invention, it should be understood that if there are terms such as "upper", "lower", "left", "right", "front", "rear", etc. indicating the orientation or positional relationship, they are based on the orientation or positional relationship shown in the drawings. This is 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. Therefore, the terms describing the positional relationship in the drawings are only for illustrative purposes and should not be construed as a limitation on the present invention. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific circumstances.

[0025] Please refer to Figures 1 to 2 , which is a self-flushing drill pipe connection device, including a housing 6. A rotating shaft 2 is rotatably arranged in the housing 6, and the rotating shaft 2 is axially relatively fixed to the housing 6; a core column 7 is axially movably arranged in the housing 6. A throttling channel 701 is arranged in the core column 7, and flow channels communicating with the throttling channel 701 are arranged on both the rotating shaft 2 and the housing 6; the relative position of the core column 7 in the housing 6 is controlled by controlling the liquid pressure flowing through the throttling channel 701; a sewage discharge hole 601 matching the core column 7 is formed in the housing 6, and the core column 7 blocks or releases the sewage discharge hole 601 during its movement.

[0026] One end of the rotating shaft 2 away from the core column 7 is provided with a connecting sleeve 14 for connecting a water pipe, and the connecting sleeve 14 is fixed on the rotating shaft 2 through a connecting pin 1. The core column 7 is provided with a limiting unit at both extreme positions inside the rotating shaft 2. In this embodiment, the core column 7 is limited by a retaining ring 10 and a return spring 9. A retaining ring 10 is provided between one side of the rotating shaft 2 facing the core column 7 and the outer housing 6; a return spring 9 is provided at one end of the core column 7 away from the rotating shaft 2.

[0027] The rotating shaft 2 is arranged in the outer housing 6 through a first bearing 4 and a second bearing 11. Along the direction from outside to inside, they are the first bearing 4 and the second bearing 11 respectively. A bearing retaining ring 12 is provided on the first bearing 4, and the bearing retaining ring 12 presses the first bearing 4 through an annular sealing ring 13; the annular sealing ring 13 is pressed by a gland 3 provided on the outer housing 6. A core column sealing ring 8 is provided between the core column 7 and the outer housing 6. A rotating shaft sealing ring 5 is provided between the rotating shaft 2 and the outer housing 6.

[0028] When drilling, drilling fluid needs to be provided inside the drill pipe. After the drilling fluid passes through the throttling channel 701, a throttling effect is formed at both ends of the throttling channel 701, and a pressure difference is formed at both ends of the throttling channel 701, and the upper pressure is greater than the lower pressure. The fluid pressure at the upper end of the core column 7 is P1, and the fluid pressure at the lower end of the core column 7 is P2. P1 is greater than P2. In the present invention, the effective acting area of the drilling fluid acting downward and the effective acting area acting upward are equal. Therefore, the core column 7 is subjected to the acting force of the downward pressure difference.

[0029] It should be noted that: the throttling effect is that when a gas or liquid flows through a cross-section in a pipeline where the cross-section suddenly shrinks and is blocked, the fluid generates vortices, collisions, and frictions at the shrinking cross-section. The fluid must overcome these resistances. Therefore, the pressure after the shrinking cross-section is much lower than the pressure before the shrinking cross-section.

[0030] The high-pressure hose is inserted into the connecting sleeve 14, and the connecting pin 1 is inserted to realize the connection between the high-pressure hose and the present invention. During the drilling operation, the outer housing 6 rotates together with the drill pipe. The rotation influence of the outer housing 6 on the rotating shaft 2 is eliminated through the first bearing 4 and the second bearing 11. The rotating shaft 2 and the high-pressure hose both remain relatively stationary, realizing the connection between the high-pressure hose and the drill pipe and not affecting the internal high-pressure drilling fluid flow path.

[0031] Example 1: Drill pipe flushing: After adding a new drill pipe, connect the device of the present invention to the tail of the drill pipe, and provide a drilling fluid flow rate of Q1, where Q1 is less than the set value Q. After the drilling fluid passes through the throttling channel 701, a throttling effect is formed at both ends of the throttling channel 701, and a pressure difference is formed at both ends of the throttling channel 701. The downward acting force of the pressure difference on the core column 7 is not sufficient to overcome the upward elastic force provided by the return spring 9, and the core column 7 remains stationary. The drain hole 601 is located below the core column 7, and the drain hole 601 connects the internal flow channel with the outside. When the drilling fluid reaches a certain height inside the drill pipe, it flows out from the drain hole, and the cuttings inside the drill pipe are discharged along with the drilling fluid, completing the cleaning of the newly added drill pipe.

[0032] Example 2: Normal drilling operation: After completing the cleaning of the newly added drill pipe, introduce drilling fluid with a flow rate of Q2, where Q2 is greater than the set value Q. After the drilling fluid passes through the throttling channel 701, a throttling effect is formed at both ends of the throttling channel 701, and a pressure difference is formed at both ends of the throttling channel 701. The downward acting force of the pressure difference on the core column 7 overcomes the upward elastic force provided by the return spring 9, and the core column 7 moves downward. After the core column 7 reaches the lower limit position, the drain hole 601 is located above the core column seal ring 8, and the drain hole 601 is cut off by the core column 7 to close the drain hole 601. The drilling fluid reaches the bottom of the hole through the internal flow channel of the device of the present invention, realizing the drilling operation.

[0033] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the purpose and scope of the present technical solution, and they should all be covered by the scope of the claims of the present invention.

Claims

1. A self-flushing drill pipe connection device, characterized in that: It includes a housing body, in which a rotating shaft is rotatably arranged, and the rotating shaft is axially relatively fixed to the housing body; a core column is axially movably arranged in the housing body, a throttling channel is arranged in the core column, and flow channels communicating with the throttling channel are arranged on both the rotating shaft and the housing body; by controlling the liquid pressure flowing through the throttling channel, the relative position of the core column in the housing body is controlled. Limiting units are arranged at both extreme positions where the core column moves up and down in the rotating shaft, and a return spring is arranged at one end of the core column away from the rotating shaft. The rotating shaft is arranged in the housing body through a first bearing and a second bearing. From the outside to the inside, they are the first bearing and the second bearing respectively; a core column seal ring is arranged between the core column and the housing body. Drilling fluid flow rate Q1 is provided, and Q1 is less than the set value Q. After the drilling fluid passes through the throttling channel, a pressure difference is formed at both ends of the throttling channel. However, the downward acting force of the pressure difference on the core column is not sufficient to overcome the upward elastic force provided by the return spring, and the core column remains stationary. The sewage discharge hole is below the core column, and the sewage discharge hole connects the internal flow channel with the outside. When the drilling fluid reaches a certain height inside the drill pipe, it flows out from the sewage discharge hole, thus completing the cleaning of the inside of the drill pipe. Drilling fluid flow rate Q2 is provided, and Q2 is greater than the set value Q. After the drilling fluid passes through the throttling channel, a pressure difference is formed at both ends of the throttling channel. However, the downward acting force of the pressure difference on the core column overcomes the upward elastic force provided by the return spring. The core column moves downward. When the core column reaches the lower extreme position, the sewage discharge hole is above the core column seal ring, and the sewage discharge hole is blocked by the core column to realize the closing of the sewage discharge hole. The drilling fluid passes through the internal flow channel to reach the bottom of the hole, realizing the drilling operation; a sewage discharge hole matched with the core column is opened on the housing body, and the core column blocks or releases the sewage discharge hole during its movement process.

2. The self-flushing drill pipe connection device according to claim 1, wherein: A connecting sleeve for connecting a water pipe is arranged at one end of the rotating shaft away from the core column.

3. The self-flushing drill pipe connection device according to claim 2, wherein: The connecting sleeve is fixed on the rotating shaft through a connecting pin.

4. The self-flushing drill pipe connection device according to claim 1, characterized in that: A bearing retaining ring is arranged on the first bearing, and the bearing retaining ring presses the first bearing through an annular seal ring.

5. The self-flushing drill pipe connection device according to claim 4, characterized in that: The annular seal ring is pressed tightly by a gland arranged on the housing body.

6. The self-flushing drill pipe connection device according to claim 1, characterized in that: A retaining ring is arranged between one side of the rotating shaft facing the core column and the housing body.

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