Rotary spraying drilling tool with telescopic nozzle

Abstract

The invention relates to the technical field of rotary spraying drilling tools, and provides a telescopic nozzle rotary spraying drilling tool which comprises a shell and a nozzle assembly and is characterized in that the nozzle assembly comprises an air cap and a nozzle which are coaxially arranged, and the nozzle is elastically installed in the shell and can stretch out of the air cap under the action of water pressure. The nozzle assembly overcomes the defects in the prior art, is reasonable in design and compact in structure, and solves the technical problems that high-pressure jet flow sprayed by an existing nozzle assembly is affected by compressed air, the atomization effect needs to be further reduced, and then the cutting capacity of the nozzle assembly needs to be improved.

Description

Technical Field

[0001] This invention relates to the field of rotary jet drilling tools, specifically to a telescopic nozzle rotary jet drilling tool. Background Technology

[0002] The nozzle assembly of a rotary jet drill can simultaneously spray high-pressure water and compressed air. The compressed air can form an air film around the high-pressure jet (the jet formed after the high-pressure water is sprayed), which allows the high-pressure jet to maintain cohesion and penetrating power over a long distance, ensuring its cutting ability.

[0003] In the prior art, the nozzle (i.e., liquid nozzle / water nozzle) and the air cap of the nozzle assembly are fixed connection structures, and the ends of the two are basically flat. This will increase the atomization effect of the high-pressure jet and weaken the cutting ability.

[0004] Therefore, we propose a telescopic nozzle rotary jet drilling tool. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a telescopic nozzle rotary jet drill bit, which overcomes the deficiencies of existing technologies. It has a reasonable design and compact structure, and solves the technical problem that the high-pressure jet ejected by existing nozzle components is affected by compressed air, and its atomization effect needs to be further reduced, thereby improving its cutting ability.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A telescopic nozzle rotary jet drilling tool includes a housing and a nozzle assembly, characterized in that: the nozzle assembly includes a coaxially arranged air cap and a nozzle, the nozzle being elastically installed in the housing and capable of extending out of the air cap under water pressure.

[0008] Furthermore, the housing is provided with a liquid channel for supplying water to the nozzle, and a transition groove is provided at the connection between the liquid channel and the nozzle, the cross-section of which is larger than the cross-section of the liquid channel;

[0009] The nozzle assembly also includes a hollow connecting shaft and a spring. The nozzle is mounted on the front end of the connecting shaft, which slides through the housing. The connecting shaft retracts under the action of the spring, and its tail end extends into the transition groove.

[0010] The housing has a mounting cavity adapted to the nozzle assembly. The air cap is mounted on the mounting base, which is installed in the mounting cavity. The nozzle is mounted on the end of the connecting shaft and passes through the mounting base and the air cap in sequence. The spring is sleeved on the connecting shaft, and its two ends abut against the radial flange of the connecting shaft and the mounting base, respectively.

[0011] Preferably, the tail end of the connecting shaft is chamfered.

[0012] Preferably, a pin is installed on the housing, and a through notch is provided on the radial flange of the connecting shaft, into which the pin extends to prevent the connecting shaft from rotating.

[0013] Furthermore, the spring is composed of stacked disc springs.

[0014] Furthermore, the outer wall of the mounting base is provided with an outer annular groove, the outer annular groove is provided with a plurality of first gas channels communicating with the gas chamber of the gas cap, the inner wall of the mounting cavity is provided with an inner annular groove, the inner annular groove is connected with the second gas channel inside the housing, and the inner annular groove is joined with the outer annular groove.

[0015] Furthermore, the air cap has an embedded sealing ring that surrounds the outer periphery of the nozzle and whose lip fits against the outer wall of the nozzle.

[0016] Furthermore, the sealing ring includes an annular body, with an outer flange and a lip formed by folding forward from the radially inner and outer sides of the annular body, respectively. The air cap includes an air cap shell, a limiting ring, and a spacer. The limiting ring is installed at the opening of the air cap shell and forms an annular mounting groove with the air cap shell. The outer flange of the sealing ring is embedded in the mounting groove, and its annular body is pressed and limited by an elastic retaining ring installed on the inner wall of the air cap shell. The lip of the sealing ring is located radially inner to the limiting ring and is spaced apart from the limiting ring.

[0017] This invention provides a telescopic nozzle rotary jet drilling tool, which has the following advantages:

[0018] 1. When the drill bit sprays high-pressure water to form a high-pressure jet to cut the original soil, the water pressure inside the drill bit is relatively high. The nozzle will extend the air cap under the action of water pressure, that is, the high-pressure water is sprayed out in front of the air cap to form a high-pressure jet, so as to reduce the atomization effect of the compressed gas sprayed out of the air cap on the high-pressure jet, thereby improving or enhancing the cutting ability of the high-pressure jet.

[0019] 2. During the initial descent of the drill bit and drilling, the nozzle assembly sprays low-pressure water, mainly to cool and lubricate the drill bit. At the same time, during the initial descent stage, the surrounding soil has not been fully infiltrated and is relatively hard. If the nozzle extends, it will collide with the soil, affecting the service life of the nozzle. At this time, the low water pressure cannot overcome the spring force to extend the nozzle, that is, the nozzle is in the retracted state, which can protect the nozzle. Attached Figure Description

[0020] Figure 1 This is a first-view exploded structural diagram of the present invention;

[0021] Figure 2 This is a schematic diagram of the exploded structure from a second perspective of the present invention;

[0022] Figure 3 This is a cross-sectional view of the housing, water spray assembly, and cover of the present invention along a longitudinal section;

[0023] Figure 4 This is an exploded cross-sectional view of the housing, water spray assembly, and cover of the present invention along the longitudinal section.

[0024] Figure 5 This is a cross-sectional view of the housing, water spray assembly, and cover of the present invention along a transverse section;

[0025] Figure 6 This is a cross-sectional view of the nozzle and air cap of the present invention;

[0026] Figure 7 This is an exploded cross-sectional view of the nozzle and gas cap of the present invention.

[0027] In the picture:

[0028] 1. Shell;

[0029] 1a. Internal water inlet;

[0030] 1b. First liquid channel;

[0031] 1c. Upper waist-shaped transition groove;

[0032] 1d, Second liquid channel;

[0033] 1e. Lower waist-shaped transition groove;

[0034] 1f, Nozzle mounting cavity;

[0035] 1f-1, Inner annular groove;

[0036] 1f-2, Second gas passage;

[0037] 1111, Capping;

[0038] 2. Nozzle assembly;

[0039] 2-1. Upper nozzle assembly;

[0040] 2-2. Lower nozzle assembly;

[0041] 21. Air cap;

[0042] 211. Sealing ring;

[0043] 211a. Ring-shaped body;

[0044] 211b. Lips;

[0045] 211b, Outward flange;

[0046] 212. Limiting ring;

[0047] 213. Gas cap outer shell;

[0048] 213a, air chamber;

[0049] 214. Elastic retaining ring;

[0050] 22. Mounting base;

[0051] 23. Nozzle;

[0052] 23a. Outer annular groove;

[0053] 23b, First gas passage;

[0054] 24. Spring;

[0055] 25. Spacer ring;

[0056] 26. Connecting shaft;

[0057] 26a. Radial flange. Detailed Implementation

[0058] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0059] See attached document Figures 1-7 A telescopic nozzle rotary jet drill bit includes a housing 1 and a nozzle assembly 2. The nozzle assembly 2 includes a coaxially arranged air cap 21 and a nozzle 23. The nozzle 23 is elastically installed in the housing 1 and can extend out of the air cap 21 under water pressure. Specifically, when the drill bit sprays high-pressure water to form a high-pressure jet to cut the undisturbed soil, the water pressure inside the drill bit is high. The nozzle 23 will overcome the elastic force under the action of water pressure to extend out of the air cap 21, thereby reducing the atomization effect of compressed gas on the high-pressure jet, and thus improving or enhancing the cutting ability of the high-pressure jet.

[0060] In this embodiment, the housing 1 has a liquid channel (both the liquid channel and the subsequent gas channel are existing technologies) for supplying water to the nozzle 23. The liquid channel and the nozzle 23 are connected by a transition groove. Specifically, the side wall of the housing 1 is formed into a waist-shaped transition groove (the long axis extends vertically). The outer side of the waist-shaped transition groove is sealed by a cover 1111. The cross-section of the transition groove is larger than the cross-section of the liquid channel. The nozzle assembly 2 also includes a hollow connecting shaft 26 and a spring 24. The nozzle 23 is installed at the front end of the connecting shaft 26. The connecting shaft 26 slides through the housing 1. Under the action of the spring 24, the connecting shaft 26 retracts backward and its tail end extends into the transition groove. The tail end of the connecting shaft 26 is located in the middle area of ​​the transition groove and its cavity connects the waist-shaped transition groove and the nozzle 23. The tail end of the connecting shaft 26 directly bears the liquid pressure in the transition groove, directly converting the liquid pressure in the waist-shaped transition groove into axial thrust, which pushes the connecting shaft 26 to move outward against the resistance of the spring 24. Specifically, at low pressure, the tail end of the connecting shaft 26 extends into the transition groove, reducing the effective flow area and delaying triggering; at high pressure, the tail end of the connecting shaft 26 is pushed out, increasing the flow area, making it easier for the fluid to rush towards the nozzle 23, forming a positive pressure feedback to a certain extent, accelerating the extension action of the nozzle 23.

[0061] Specifically, the housing 1 has a nozzle mounting cavity 1f adapted to the nozzle assembly 2. The air cap 21 is threaded onto the mounting base 22, and the mounting base 22 is threaded into the nozzle mounting cavity 1f. The nozzle is mounted on the end of the connecting shaft 26 and passes through the mounting base 22 and the air cap 21 in sequence. The connecting shaft 26 is slidably inserted into the housing 1. The spring 24 is formed by stacking butterfly springs. A set of stacked butterfly springs is sleeved on the connecting shaft 26, and its two ends abut against the radial flange 26a of the connecting shaft 26 and the mounting base 22, respectively.

[0062] In this embodiment, there are two nozzle assemblies 2, namely upper nozzle assembly 2-1 and lower nozzle assembly 2-2. The upper nozzle assembly 2-1 and lower nozzle assembly 2-2 are arranged vertically at intervals and are respectively located on the radial sides of the housing 1. First, the cross-sectional dimensions of the upper and lower transition grooves are larger than the cross-sectional dimensions of the liquid channel. After the water flows from the liquid channel into the transition groove, the flow velocity decreases and the pressure increases. In addition, the transition groove is waist-shaped and has a flat structure, which allows the water to fully diffuse after entering the groove and act evenly on the end face of the connecting shaft 26. As a result, the connecting shaft 26 can be stably pushed forward. The transition groove includes an upper waist-shaped transition groove 1c corresponding to the upper nozzle assembly 2-1 and a lower waist-shaped transition groove 1e of the lower nozzle assembly 2-2. Part of the liquid channel is shown in the figure, namely the first liquid channel 1b and the second liquid channel 1d. The first liquid channel 1b connects the internal water inlet 1a and the upper end of the upper waist-shaped transition groove. The second liquid channel 1d is inclined and connects the lower end of the upper waist-shaped transition groove 1c and the upper end of the lower waist-shaped transition groove 1e, respectively. The cross-sections (i.e., the cross-sections perpendicular to their own channel axes) of the first liquid channel 1b and the second liquid channel 1d are both circular and have the same size. The cross-sectional dimensions of both are smaller than the cross-sectional dimensions of the upper waist-shaped transition groove 1c and the lower waist-shaped transition groove 1e.

[0063] In this embodiment, a pin is installed on the housing 1, and a through notch is provided on the radial flange 26a of the connecting shaft 26. The pin extends into the notch to prevent the connecting shaft 26 from rotating, reduce energy loss, and ensure reliable extension of the connecting shaft. However, the pin slides with the notch to accommodate the forward and backward movement of the connecting shaft 26.

[0064] In this embodiment, the outer wall of the mounting base 22 is provided with an outer annular groove 23a, and the outer annular groove 23a is provided with a plurality of first gas channels 23b communicating with the gas chamber 213a of the gas cap 21. The inner wall of the mounting cavity is provided with an inner annular groove 1f-1, and the inner annular groove 1f-1 is connected with the second gas channel 1f-2 in the housing 1. The inner annular groove and the outer annular groove 23a are joined together.

[0065] In this embodiment, the air cap 21 has an embedded sealing ring 211, which surrounds the outer periphery of the nozzle and its lip 211b fits against the outer wall of the nozzle. Compressed air entering the air chamber forces the lip 211b to undergo elastic deformation and expand outward, thereby causing the compressed gas to be ejected outward. Specifically, the sealing ring 211 includes an annular body 211a, an outer flange 211b and a lip 211b formed by folding forward from the radial inner and outer sides of the annular body 211a, respectively. The air cap 21 includes an air cap shell 213, a limiting ring 212 and a spacer 25. The limiting ring 212 is installed at the opening of the air cap shell 213 and forms an annular mounting groove with the air cap shell 213. The outer flange 211b of the sealing ring 211 is embedded in the mounting groove and its annular body 211a is pressed and limited by an elastic retaining ring 214 installed on the inner wall of the air cap shell 213. The lip 211b of the sealing ring 211 is disposed on the radial inner side of the limiting ring 212 and is spaced apart from the limiting ring 212. During use, mud may enter and clump between the nozzle and the air cap 21, forming a blockage. The lip 211b generally expands radially outward under the action of compressed air. The retraction of the nozzle will cause the lip 211b to turn inward or arch, thus changing the single deformation of the lip 211b, which makes it easier for the blockage to loosen and separate.

[0066] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0067] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A telescopic nozzle rotary jet drilling tool, comprising a housing and a nozzle assembly, characterized in that: The nozzle assembly includes a coaxially arranged air cap and a nozzle, the nozzle being elastically mounted in the housing and capable of extending out of the air cap under water pressure.

2. The telescopic nozzle rotary jet drilling tool according to claim 1, characterized in that: The housing has a liquid channel inside for supplying water to the nozzle. The liquid channel and the nozzle are connected by a transition groove, and the cross-section of the transition groove is larger than the cross-section of the liquid channel. The nozzle assembly also includes a hollow connecting shaft and a spring. The nozzle is mounted on the front end of the connecting shaft, which slides through the housing. The connecting shaft retracts under the action of the spring, and its tail end extends into the transition groove.

3. A telescopic nozzle rotary jet drilling tool according to claim 2, characterized in that: The housing has a mounting cavity adapted to the nozzle assembly. The air cap is mounted on the mounting base, and the mounting base is mounted in the mounting cavity. The nozzle is mounted on the end of the connecting shaft and passes through the mounting base and the air cap in sequence. The spring is sleeved on the connecting shaft, and its two ends abut against the radial flange of the connecting shaft and the mounting base, respectively.

4. A telescopic nozzle rotary jet drilling tool according to claim 3, characterized in that: The tail end of the connecting shaft is chamfered.

5. A telescopic nozzle rotary jet drilling tool according to claim 3, characterized in that: A pin is installed on the housing, and a through notch is provided on the radial flange of the connecting shaft. The pin extends into the notch to prevent the connecting shaft from rotating.

6. A telescopic nozzle rotary jet drilling tool according to claim 3, characterized in that: The outer wall of the mounting base is provided with an outer annular groove, and the outer annular groove is provided with a plurality of first gas channels communicating with the gas chamber of the gas cap. The inner wall of the mounting cavity is provided with an inner annular groove, and the inner annular groove is connected with a second gas channel inside the shell. The inner annular groove and the outer annular groove are joined together.

7. A telescopic nozzle rotary jet drilling tool according to claim 3, characterized in that: The spring is made up of stacked disc springs.

8. A telescopic nozzle rotary jet drilling tool according to claim 1, characterized in that: The air cap has an embedded sealing ring that surrounds the outer periphery of the nozzle and whose lip fits against the outer wall of the nozzle.

9. A telescopic nozzle rotary jet drilling tool according to claim 8, characterized in that: The sealing ring includes an annular body, with an outer flange and a lip formed by folding forward from the radially inner and outer sides of the annular body, respectively. The gas cap includes a gas cap shell, a limiting ring, and a spacer. The limiting ring is installed at the opening of the gas cap shell and forms an annular mounting groove with the gas cap shell. The outer flange of the sealing ring is embedded in the mounting groove, and its annular body is pressed and limited by an elastic retaining ring installed on the inner wall of the gas cap shell. The lip of the sealing ring is located on the radially inner side of the limiting ring and is spaced apart from the limiting ring.

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