Hydraulic ejector

Abstract

The invention relates to the technical field of hydraulic ejectors, and discloses a hydraulic ejector which comprises an ejector body, centralizers are arranged at the top and the bottom of the ejector body respectively, a liquid inlet pipe communicated with the ejector body is communicated with the centralizer at the top of the ejector body, and a pressure pipeline is connected in the ejector body. Through the cooperation of the piston and the elastic piece, the ejector can sense the pressure change caused by abrasion of the spray head in real time, and after it is detected that the system pressure is reduced to the preset threshold value, the spray head is automatically triggered to adjust and switch, so that the continuity and reliability of hydraulic ejection operation are effectively improved.

Description

Technical Field

[0001] The invention relates to the technical field of hydraulic ejectors, and in particular to a hydraulic ejector. Background Art

[0002] Hydraulic jet fracturing technology is an engineering measure widely used in low-permeability, tight oil and gas reservoirs and coalbed methane well production enhancement operations. Its basic principle is to use a high-pressure pump to spray fracturing fluid through a nozzle at high speed onto the surface of the formation rock, achieve rock cracking through strong impact flow, and further use continuous high-pressure liquid to promote crack expansion, while transporting proppants to maintain crack conductivity, thereby improving the seepage channel between the wellbore and the reservoir and increasing oil and gas production capacity.

[0003] In this type of operation, the nozzle is a key component in the formation of hydraulic jets, and its jet efficiency and direction control directly affect the crack morphology and operation results. Since the nozzle is often in a high-pressure environment of more than tens of MPa, accompanied by a large number of high-hardness particles (such as quartz sand) scouring, it is very easy to wear, resulting in the expansion of the nozzle diameter, the deviation of the jet direction or the decrease of the speed, which will cause the crack to deviate, the operation efficiency to decrease, and even the operation to fail. Therefore, nozzle wear management and efficient switching are the key to ensuring the quality of hydraulic jetting operations.

[0004] In the prior art, for example, patent CN117627611A discloses a directional hydraulic jet acid fracturing device, which uses a damping ball to move under the action of fluid pressure to sequentially open or close multiple jet holes, thereby adaptively adjusting the number of jet holes according to the change in fluid flow. Although this solution can improve the problem of pump blocking or insufficient jet speed to a certain extent, since its action is based on overall flow control, it cannot respond to the actual wear state of a single nozzle in real time, and there is a problem that the nozzle has been severely worn and cannot be switched in time, affecting the stability of the operation. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present invention provides a hydraulic ejector, aiming to alleviate the above problems at least to a certain extent.

[0006] The above technical objectives of the present invention are achieved through the following technical solutions: A hydraulic ejector comprises an ejector body, wherein the top and bottom of the ejector body are respectively provided with centralizers, the centralizer on the top of the ejector body is connected with a liquid inlet pipe connected with the ejector body, a pressure pipe is connected in the ejector body, a switching chamber is formed between the pressure pipe and the ejector body, an ejection port a connected with the switching chamber is formed on the outer wall of the ejector body, a plurality of nozzles are arranged in the switching chamber, a connecting ring is fixed on the outer wall of the pressure pipe, an ejection port b is formed on the connecting ring, a connecting plate is arranged in the switching chamber, the nozzle is arranged on the connecting plate, a piston is arranged in the pressure pipe, an elastic member is arranged between the piston and the pressure pipe, an ejection mechanism is arranged between the piston and the ejection port a, the mechanism can push the piston down to a predetermined position when the pressure in the pressure pipe reaches a preset value, release the nozzle corresponding to the ejection port a, and make it sleeved in the ejection port a, a switching mechanism is arranged between the piston and the connecting plate, when the pressure in the pressure pipe drops to a preset value, the piston rises to a preset position, so that the connecting plate moves downward accordingly.

[0007] Preferably, the injector body comprises an upper shell and a lower shell, which are fastened together by threads, and the injection port a is opened at the junction of the upper shell and the lower shell.

[0008] Preferably, the connecting plate is provided with a plurality of mounting openings, the nozzle sleeve is arranged in the mounting openings and is fastened by bolts.

[0009] Preferably, the switching mechanism includes a limit bracket connected to the outer wall of the pressure pipe, two transverse rods are slidably connected to the limit bracket, a vertical rod a is connected to the bottom of the piston, one end of the vertical rod a extends into the cavity between the pressure pipe and the injector body, and is rotatably connected to a connecting rod a, the other end of the connecting rod a is rotatably connected to the transverse rod, and a connecting rod b is also rotatably connected to the transverse rod, one end of the connecting rod b is rotatably connected to the vertical rod b, a switching frame is provided on the top of the vertical rod b, a snap-in plate is provided on the switching frame, a plurality of snap-in grooves matching the snap-in plates are opened on the side walls of the connecting plate, and a spring a is connected between the two transverse rods.

[0010] Preferably, the clamping piece is slidably connected to the switching frame, and a spring b is connected between the clamping piece and the switching frame.

[0011] Preferably, the switching mechanism also includes a gear a arranged on the nozzle, a ratchet mechanism is provided between the gear a and the nozzle, a slide rail a is connected to the connecting ring, the slide rail a includes an inclined section opening and a straight section opening, and a rack a adapted to the gear a is slidably connected to the slide rail a.

[0012] Preferably, the switching mechanism is capable of rotating the nozzle before switching the nozzle; The switching mechanism also includes a guide cylinder rotatably connected to the limit bracket, the outer wall of the guide cylinder is provided with a spiral opening, the first section of the spiral opening is provided with a straight opening, the transverse rod is connected with a guide rod corresponding to the straight opening, one end of the guide cylinder is connected with a gear b, one side of the slide rail a is connected with a slide rail b, the slide rail b is slidably connected with a connecting frame, one end of the connecting frame is connected with a rack b meshing with the gear b, and the other end is connected with a telescopic rod, and the telescopic shaft of the telescopic rod is connected to the rack a.

[0013] Preferably, the ejection mechanism includes a base bolted to the mounting opening, the nozzle is slidably connected to the base, and a spring c is connected to the base.

[0014] Preferably, a connecting groove is provided on the lower shell body, an ejection frame is slidably connected in the connecting groove, a spring d is connected between the ejection frame and the connecting groove, a connecting rod c is rotatably connected to the bottom of the ejection frame, a connecting rod a is connected to the bottom of the connecting rod c, and a connecting rod b is connected to the vertical displacement rod a, which extends into the connecting groove and contacts the connecting rod a.

[0015] Preferably, a connecting shaft slidably connected to the vertical moving rod b is connected to the bottom of the switching frame, and a spring e is connected between the connecting shaft and the vertical moving rod b.

[0016] In summary, the present invention mainly has the following beneficial effects: The present invention, by setting the cooperation between the piston and the elastic member, enables the injector to sense the pressure change caused by the nozzle wear in real time, and automatically triggers the nozzle adjustment and switching action after detecting that the system pressure drops to a preset threshold, thereby effectively improving the continuity and reliability of the hydraulic injection operation. Compared with the existing solutions that rely on manual judgment or rely on multi-nozzle timed switching, the present invention omits the complicated control system through hydraulic automatic response, realizes the instant identification and processing of the nozzle wear state, and responds more promptly and accurately, significantly improving the operation efficiency.

[0017] In the present invention, before the nozzle switches, the piston drives the nozzle body currently in use to rotate at an angle during the rising process, so that the sprayed liquid can flush the area of ​​the nozzle inner wall that has not been severely worn, avoiding continuing to act on the original location with severe local wear. This rotation adjustment mechanism effectively restores the nozzle flow resistance characteristics, stabilizes the injection pressure, extends the service life of the current nozzle, and significantly reduces the number of premature nozzle switching. Through multiple rotation fine-tuning, the nozzle can disperse the force and flushing in different areas, greatly improving the comprehensive durability of a single nozzle.

[0018] The present invention is different from the traditional method of directly switching the nozzle after wear. The present invention sets a rotation adjustment process before the nozzle is switched, which not only makes full use of the remaining intact area of ​​the nozzle and avoids waste of resources, but also can maintain the stability of the jet direction during the operation, prevent the problem of abnormal crack direction caused by jet deviation, and ensure the continuity and controllability of the production increase operation. The overall structure of the present invention is compact, the action logic is natural, the rotation adjustment and nozzle switching are automatically triggered by pressure changes, the mechanical action is reliable, and no complex electronic control system is required. It is particularly suitable for hydraulic jet fracturing operations in oil and gas wells under high pressure and high sand environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 It is a cross-sectional schematic diagram of the overall structure of the present invention; Figure 3 yes Figure 2 A schematic diagram of the enlarged local structure at a in the middle; Figure 4 It is a schematic diagram of the connecting ring structure of the present invention; Figure 5 is a schematic diagram of the card slot of the present invention; Figure 6 is a schematic diagram of the switching mechanism structure of the present invention; Figure 7 It is a schematic diagram of the structure of the nozzle of the present invention; Figure 8 It is a schematic diagram of the structure of the traverse rod of the present invention; Fig. 9 yes Figure 8 A magnified schematic diagram of the local structure at point b in the middle; Fig.10 It is a schematic diagram of the structure of the slide rail a and the slide rail b of the present invention; Fig.11 It is a schematic diagram of the connecting shaft structure of the present invention; Fig.12 yes Figure 5 Enlarged schematic diagram of the local structure at point c in the middle.

[0020] Reference numerals: 100, injector body; 101, centralizer; 102, liquid inlet pipe; 103, pressure pipe; 104, injection port a; 105, nozzle; 106, connecting ring; 107, injection port b; 108, connecting plate; 109, piston; 110, elastic member; 111, upper shell; 112, lower shell; 113, installation port; 200, limit bracket; 201, transverse rod; 202, vertical rod a; 203, connecting rod a; 204, connecting rod b; 205, vertical rod b; 206, switching frame; 207, clamping piece; 208, clamping groove; 209, spring a; 210, spring b; 300, gear a; 301, slide rail a; 302, oblique section opening; 303, straight section opening; 304, rack a; 305, guide cylinder; 306, spiral opening; 307, straight section opening; 308, guide rod; 309, rack b; 310, slide rail b; 311, connecting frame; 312, telescopic rod; 313, gear b; 400, base; 401, spring c; 402, connecting groove; 403, ejector frame; 404, spring d; 405, connecting rod c; 406, connecting rod a; 407, connecting rod b; 408, connecting shaft; 409, spring e. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions 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. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] refer to Figure 1-Figure 12A hydraulic ejector comprises an ejector body 100, wherein the top and bottom of the ejector body 100 are respectively provided with a centralizer 101, the centralizer 101 at the top of the ejector body 100 is connected with a liquid inlet pipe 102 connected with the ejector body 100, a pressure pipe 103 is connected inside the ejector body 100, an ejection port a104 connected with a switching chamber is opened on the outer wall of the ejector body 100, a plurality of nozzles 105 are arranged in the switching chamber, the ejection port a104 corresponds to one of the nozzles 105, a connecting ring 106 is fixed on the outer wall of the pressure pipe 103, an ejection port b107 connected with one of the nozzles 105 is opened on the connecting ring 106, a connecting plate 108 is arranged in the switching chamber, and the connecting plate 108 is slidably connected to the ejector body 104. On the connecting ring 106, the nozzle 105 is arranged on the connecting plate 108, a piston 109 is arranged in the pressure pipe 103, an elastic member 110 is arranged between the piston 109 and the pressure pipe 103, and an ejection mechanism is arranged between the piston 109 and the injection port a104. When the pressure in the pressure pipe 103 reaches a preset value, the piston 109 is pushed down to a predetermined position, and the nozzle 105 corresponding to the injection port a104 is released, so that the nozzle 105 is sleeved in the injection port a104. A switching mechanism is arranged between the piston 109 and the connecting plate 108. When the pressure in the pressure pipe 103 drops to a preset value, the piston 109 rises to a preset position, so that the connecting plate 108 moves downward accordingly, thereby triggering the switching of the nozzle 105. Among them, the switching mechanism can rotate the nozzle 105 before switching the nozzle 105.

[0023] Through the above arrangement, at the beginning of the operation, the high-pressure fluid enters the injector body 100 from the outside through the liquid inlet pipe 102. At this time, the nozzle 105 is in good condition and the injection effect is stable. The pressure in the pressure pipe 103 is maintained within the preset range. The piston 109 is driven to a predetermined position by the pressure, and controls a nozzle 105 to be firmly sleeved at the injection port a104, and starts normal operation.

[0024] As the spraying operation proceeds, the nozzle 105 is in continuous contact with the high-pressure liquid and the particles carried (such as quartz sand), resulting in the gradual accumulation of nozzle wear. This wear will cause the nozzle aperture to increase, the spray flow rate to decrease, and the pressure in the pressure pipe 103 will also be affected. When the nozzle is worn, the resistance of the spray flow decreases, resulting in a decrease in the overall flow pressure of the injector.

[0025] In the present application, the setting of the piston 109 can detect this pressure change in real time. The piston 109 senses the change in pressure and automatically rises to a preset position. At this time, the next spare nozzle 105 is released through the switching mechanism and installed in the injection port a104, thereby realizing the automatic switching of the nozzle 105. This switching mechanism effectively avoids the decrease in injection efficiency after the nozzle 105 is worn, and ensures the stability of the jet flow. Compared with the traditional multi-nozzle solution, the present invention automatically triggers the switching of the nozzle 105 through pressure changes, can flexibly deal with the problem of unstable injection caused by nozzle wear, does not rely on manual intervention or preset programs, responds more promptly, and switches more accurately.

[0026] In addition, since the nozzle 105 is fixed in position during use, when the sprayed liquid flows at high speed, it will produce concentrated scouring on a specific area of ​​the inner wall of the nozzle 105, causing local wear. As the operation time goes by, the wear of the inner wall at this local position gradually increases, and the flow channel cross-section changes, causing the jet morphology to be turbulent and the flow resistance to decrease, which eventually causes the overall injection pressure of the system to drop. Based on this phenomenon, the present invention uses the change in injection pressure as an indirect detection signal for the wear of the nozzle 105, and designs an automatic switching mechanism for the nozzle 105 driven by the piston 109.

[0027] At the beginning of the operation, the pressure pipe 103 in the injector body 100 maintains a high pressure state, the piston 109 is pressed in the lower position by the high pressure liquid, the connecting plate 108 is locked and fixed, the injection port a104 is aimed at the first nozzle 105, and the system maintains normal and stable injection. At this time, since the nozzle 105 is not significantly worn, the injection energy is concentrated and the jet direction is stable, which effectively guarantees the cracking and crack extension process of the underground rock. As the injection operation continues, the local wear of the inner wall of the nozzle 105 continues to increase. When the wear causes the flow resistance to decrease, the system detects that the pressure is lower than the preset threshold, and the piston 109 begins to rise under the action of the elastic member 110. During the rising process of the piston 109, the present invention also provides a rotating component to drive the current nozzle 105 body to rotate at an angle. Through this rotation action, the injection liquid re-flushes the area of ​​the inner wall of the nozzle 105 that has not been severely worn, avoiding continuing to act on the original severely worn parts, thereby restoring the flow resistance characteristics of the nozzle 105 to a certain extent, stabilizing the injection pressure, and extending the service life of the current nozzle 105. This rotation adjustment can not only timely compensate for the abnormal jet flow caused by local wear, but also significantly reduce the number of times the spare nozzle 105 is switched in advance due to local damage, thereby improving the continuity of operation and the efficiency of system use.

[0028] When the overall wear of the nozzle 105 accumulates to a certain extent after multiple rotation adjustments, and the injection effect can no longer be improved by rotation, the present invention further switches the spare nozzle 105 by resetting the piston 109 and actuating the switching mechanism to ensure that the injection operation continues. The present invention detects the pressure change caused by the local wear of the nozzle 105, and combines the piston 109 to drive the nozzle 105 body to rotate and adjust, so as to fully extend the service life of the current nozzle 105 before the nozzle 105 is switched, reduce the number of nozzle 105 switching times, and improve the stability and economy of the injection operation, which is particularly suitable for hydraulic jet fracturing scenarios with high pressure and high load continuous operation.

[0029] As a further solution of the present invention, the injector body 100 includes an upper shell 111 and a lower shell 112, which are fastened together by threads, and the injection port a104 is opened at the junction of the two; The injector body 100 is formed by the upper shell 111 and the lower shell 112 being threadedly connected. The structure is firm and easy to process and assemble as a whole. It can effectively ensure the sealing performance and mechanical strength of the injector body 100 under high pressure environment, and improve the pressure resistance and reliability of the device. The injection port a104 is arranged at the junction of the upper shell 111 and the lower shell 112, which makes the installation, calibration and subsequent maintenance of the injection port more convenient, and facilitates the precise alignment of the injection port and the internal nozzle 105 during assembly or maintenance, ensuring the consistency and stability of the injection flow direction.

[0030] As a further solution of the present invention, a plurality of mounting openings 113 are provided on the connecting plate 108, and the nozzle 105 is sleeved in the mounting openings 113 and fastened by bolts; Through the above arrangement, a plurality of mounting openings 113 are provided on the connection plate 108, and each nozzle 105 is respectively sleeved in the corresponding mounting opening 113 and fixed by bolts, so that a reliable and stable connection between the nozzle 105 and the connection plate 108 can be achieved, and the risk of the nozzle 105 loosening, deflecting or even falling off due to high-pressure shock or vibration during the spraying operation can be effectively prevented. The bolt fastening method not only improves the firmness and safety of the installation of the nozzle 105, but also facilitates the replacement and maintenance of the nozzle 105 in the later stage. When the nozzle 105 is worn or fails, it can be quickly disassembled and replaced by simply loosening the bolts, thereby improving the maintenance efficiency.

[0031] As a further solution of the present invention, the switching mechanism includes a limit bracket 200 connected to the outer wall of the pressure pipe 103, two transverse rods 201 are slidably connected to the limit bracket 200, a vertical rod a202 is connected to the bottom of the piston 109, one end of the vertical rod a202 extends into the cavity between the pressure pipe 103 and the injector body 100, and is rotatably connected to a connecting rod a203, the other end of the connecting rod a203 is rotatably connected to the transverse rod 201, the transverse rod 201 is also rotatably connected to a connecting rod b204, one end of the connecting rod b204 is rotatably connected to a vertical rod b205, a switching frame 206 is provided on the top of the vertical rod b205, a clamping piece 207 is provided on the switching frame 206, a plurality of clamping grooves 208 adapted to the clamping piece 207 are opened on the side wall of the connecting plate 108, and a spring a209 is connected between the two transverse rods 201; Through the above arrangement, when the liquid enters the pressure pipe 103 and the piston 109 is displaced downward by the pressure, the vertical moving rod a202 on it can be moved downward, and the two transverse moving rods 201 can slide horizontally along the limit bracket 200 through the connecting rod a203. At this time, the connecting rod b204 can be rotated and lift the switching frame 206 under the force. When the switching frame 206 rises, the clamping piece 207 on it can contact the clamping groove 208, and when the piston 109 moves downward to the predetermined position, the clamping piece 207 is clamped in one of the clamping grooves 208. As the work proceeds, the nozzle 105 is gradually worn in a local area of ​​its inner wall under the long-term flushing of high-pressure liquid and proppant particles, resulting in changes in the injection flow channel, a decrease in the system flow resistance, and then a decrease in the liquid pressure in the pressure pipe 103. When the pressure drops to a preset threshold, the piston 109 begins to move upward under the action of the elastic member 110. At this time, the vertical rod a202 moves up with the piston 109, and drives the connecting rod a203 to pull back, so that the two transverse rods 201 slide in opposite directions along the limit bracket 200. During the sliding process of the transverse rod 201, the connecting rod b204 rotates in the opposite direction due to being driven, and the vertical rod b205 moves downward with the movement of the connecting rod b204, driving the switching frame 206 to descend as a whole. As the switching frame 206 descends, the clamping piece 207 clamped in the clamping groove 208 can move the connecting plate 108 downward by cooperating with the clamping groove 208, so that the connecting plate 108 produces a fixed step displacement along the direction of the pressure pipe 103. Through the downward movement of the connecting plate 108, the nozzle 105 originally aligned with the injection port a104 exits the injection position, and the next spare nozzle 105 accurately aligns with the injection port a104 with the movement of the connecting plate 108, realizing the switching of the nozzle 105 position.

[0032] As a further solution of the present invention, the card plate 207 is slidably connected to the switching frame 206, and a spring b210 is connected between the card plate 207 and the switching frame 206; Through the above arrangement, the clamping piece 207 is slidably connected to the switching frame 206, and a spring b210 is arranged between adjacent clamping pieces 207, so that the clamping piece 207 can be elastically retracted relatively independently on the switching frame 206. Such a design can give the clamping piece 207 a certain floating buffering capacity during the movement of the switching frame 206. When the clamping piece 207 contacts or disengages from the clamping groove 208 of the connecting plate 108, it can automatically adapt to the position difference of the connecting plate 108, ensuring that the clamping action is smoother and softer, and avoiding the jamming, impact or component damage caused by rigid contact. When replacing the damaged nozzle 105 later, the upper shell 111 or the lower shell 112 can be rotated to separate the two, so that the structural components such as the vertical shift rod and the horizontal shift rod 201 can be exposed, so as to facilitate the displacement of the clamping piece 207 to disengage it from the clamping groove 208. The operator can freely adjust the position of the connecting plate 108 in this state to complete the disassembly of the damaged nozzle 105 and the installation of the new nozzle 105.

[0033] As a further solution of the present invention, the switching mechanism further includes a gear a300 disposed on the nozzle 105, a ratchet mechanism is disposed between the gear a300 and the nozzle 105, a slide rail a301 is connected to the connecting ring 106, the slide rail a301 includes an oblique section opening 302 and a straight section opening 303, and a rack a304 adapted to the gear a300 is slidably connected to the slide rail a301; Through the above arrangement, during the initial operation, the piston 109 is displaced downward by the pressure, and the rack a304 provided at this time can be displaced downward and slide in the slide rail a301. In the initial state, the rack a304 is not engaged with the gear a300. When the rack a304 slides to the end of the inclined section opening 302 on the slide rail a301, it can be engaged with the gear a300. As the rack a304 continues to move downward, it can slide in the straight section opening 303 and drive the gear a300 to rotate. The ratchet mechanism provided can allow the gear a300 to idle on the outer wall of the nozzle 105 without affecting the position of the nozzle 105, avoiding the problem of motion interference of the nozzle 105 when the nozzle 105 needs to cooperate with the injection port a104. Later, due to the decrease in pressure in the pressure pipe 103, the piston 109 begins to move upward under the action of the elastic member 110, driving the rack a304 to slide in the opposite direction along the slide rail a301. During the upward movement of the rack a304, since the rack a304 and the gear a300 are in meshing state, the movement of the rack a304 can continue to drive the gear a300 to rotate. Since a ratchet mechanism is provided between the gear a300 and the nozzle 105, the ratchet mechanism allows the gear a300 to drive the nozzle 105 body to rotate at an angle when the piston 109 rises. When the nozzle 105 is about to leave the injection port a104, the rack a304 can slide in the inclined section port 302 on the slide rail a301, leaving the nozzle 105 and the gear a300, to avoid subsequent interference with the switching of the nozzle 105. Through the above-mentioned rotation action, the local inner wall area of ​​the nozzle 105 that was originally concentratedly flushed by the liquid is shifted, and the sprayed liquid can flush the area of ​​the inner wall of the nozzle 105 that has not been severely worn, thereby restoring the symmetry and injection resistance of the nozzle 105 flow channel to a certain extent, maintaining the stability of the jet direction, and extending the service life of the nozzle 105.

[0034] As a further solution of the present invention, the switching mechanism also includes a guide cylinder 305 rotatably connected to the limit bracket 200, the outer wall of the guide cylinder 305 is provided with a spiral opening 306, the first section of the spiral opening 306 is provided with a straight section opening 307, the transverse rod 201 is connected with a guide rod 308 corresponding to the straight section opening 307, one end of the guide cylinder 305 is connected with a gear b313, one side of the slide rail a301 is connected with a slide rail b310, the slide rail b310 is slidably connected with a connecting frame 311, one end of the connecting frame 311 is connected with a rack b309 meshing with the gear b313, and the other end is connected with a telescopic rod 312, and the telescopic shaft of the telescopic rod 312 is connected to the rack a304; Through the above arrangement, when the traverse rod 201 slides laterally on the limit bracket 200, the guide rod 308 connected to the traverse rod 201 can be accurately inserted into the straight section opening 307 set on the outer wall of the guide cylinder 305. As the traverse rod 201 moves further, the guide rod 308 slides along the straight section opening 307 and finally enters the starting section of the spiral opening 306. Since the spiral opening 306 is distributed in a spiral line, the guide cylinder 305 can be forced to rotate on the limit bracket 200 during the process of the guide rod 308 continuing to slide along the spiral opening 306. The linear sliding action of the traverse rod 201 is converted into the rotational motion of the guide cylinder 305, and the rotation of the guide cylinder 305 can cause the connecting frame 311, the telescopic rod 312 and the rack a304 to move downward through the gear b313 and the rack b309. On the contrary, when the piston 109 is reset upward, the traverse rod 201 slides in the reverse direction, the guide rod 308 moves in the reverse direction along the spiral opening 306, and the guide cylinder 305 rotates in the reverse direction accordingly. The reverse rotation of the guide cylinder 305 can also drive the rack b309, the connecting frame 311 and the telescopic rod 312 to move upward, so as to further adjust the angle of the nozzle 105 and ensure that the spray flow continuously acts on the area of ​​the inner wall of the nozzle 105 that has not been worn.

[0035] As a further solution of the present invention, the ejection mechanism includes a base 400 bolted to the mounting port 113, the nozzle 105 is slidably connected to the base 400, and a spring c401 is connected between the nozzle 105 and the base 400, a connecting groove 402 is provided on the lower shell 112, an ejection frame 403 is slidably connected in the connecting groove 402, a spring d404 is connected between the ejection frame 403 and the connecting groove 402, a connecting rod c405 is rotatably connected to the bottom of the ejection frame 403, a connecting rod a406 is connected to the bottom of the connecting rod c405, and a connecting rod b407 extending into the connecting groove 402 and contacting the connecting rod a406 is connected to the vertical displacement rod a202; Through the above arrangement, in the initial state, the spring d404 is in a stretched state. When the piston 109 moves downward, it drives the vertical rod a202 to move downward together. The vertical rod a202 is connected to the connecting rod a406 through the connecting rod b407 of the extension section, and further drives the connecting rod c405 to move. At this time, the spring d404 releases potential energy, which can make the ejection frame 403 slide in the connecting groove 402, and will no longer touch the nozzle 105, so that the nozzle 105 can be matched in the injection port a104, and the position of the nozzle 105 can be fixed. As the operation continues, the nozzle 105 is gradually worn in the local area under the long-term flushing of high-pressure liquid and proppant particles, resulting in a decrease in the flow resistance of the injector, which in turn causes the liquid pressure in the pressure pipe 103 to drop. When the pressure drops to the preset threshold, the piston 109 starts to move upward under the action of the elastic member 110, driving the vertical rod a202 and its connected connecting rods b407 and a406 to move upward. The connecting rod c405 rotates in the opposite direction under the action of the connecting rod a406, so that the ejection frame 403 can press the nozzle 105 to separate the nozzle 105 from the injection port a104, thereby achieving the purpose of allowing the nozzle 105 to be switched smoothly.

[0036] As a further solution of the present invention, a connecting shaft 408 slidably connected to the vertical moving rod b205 is connected to the bottom of the switching frame 206, and a spring e409 is connected between the connecting shaft 408 and the vertical moving rod b205; Through the above arrangement, when the piston 109 moves downward, the switching frame 206 moves upward, and the engaging piece 207 on the switching frame 206 can cooperate with the engaging groove 208. When the piston 109 moves upward, since the piston 109 has not yet returned to the origin, the ejection frame 403 has not yet returned to the origin, that is, the nozzle 105 currently in operation is still partially in the injection port a104 and cannot be separated from the injection port a104. At this time, the piston 109 is still on the way upward, and the spring e409 arranged here plays a role, and can stretch the spring e409 when the vertical shift rod b205 moves downward without affecting the position of the switching frame 206, thereby avoiding the situation of motion interference. When the piston 109 moves upward to the origin, the ejector frame 403 returns to its original position completely, allowing the nozzle 105 to completely leave the injection port a104, and the potential energy of the spring e409 can be released, allowing the switching frame 206 to move downward and move the position of the connecting plate 108, thereby allowing the spare nozzle 105 to move to the position of the injection port a104. At this time, the spare nozzle 105 is in good condition. In the subsequent process in which the piston 109 continues to move downward under the action of pressure, the vertical shift rod a202 moves downward synchronously, and the ejector frame 403 is driven again through the connecting rod mechanism so that the nozzle 105 can be sleeved in the injection port a104 under the action of the spring c401, and the normal injection operation of the system is restored. Although the embodiments of the present invention have been shown and described, it can be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the attached claims and their equivalents.

Claims

1. A hydraulic ejector, comprising an ejector body (100), wherein the top and bottom of the ejector body (100) are respectively provided with centralizers (101), the centralizer (101) at the top of the ejector body (100) is connected to a liquid inlet pipe (102) connected to the ejector body (100), a pressure pipe (103) is connected inside the ejector body (100), a switching chamber is formed between the pressure pipe (103) and the ejector body (100), an ejection port a (104) connected to the switching chamber is formed on the outer wall of the ejector body (100), and a plurality of ejector heads (105) are arranged in the switching chamber, characterized in that: A connecting ring (106) is fixed to the outer wall of the pressure pipe (103), and a spray port b (107) is provided on the connecting ring (106). A connecting plate (108) is provided in the switching chamber, and the spray head (105) is arranged on the connecting plate (108). A piston (109) is provided in the pressure pipe (103), and an elastic member (110) is provided between the piston (109) and the pressure pipe (103). An ejection mechanism is provided between the piston (109) and the spray port a (104), and the mechanism can push the piston (109) down to a predetermined position when the pressure in the pressure pipe (103) reaches a preset value, thereby releasing the spray port a (104) corresponding to the spray port. The nozzle (105) is sleeved in the injection port a (104); when the pressure in the pressure pipe (103) drops to a preset value, the piston (109) rises to a preset position, causing the connecting plate (108) to move downward accordingly; a plurality of mounting ports (113) are provided on the connecting plate (108); the nozzle (105) is sleeved in the mounting ports (113) and is fastened by bolts; the ejection mechanism comprises a base (400) bolted to the mounting ports (113); the nozzle (105) is slidably connected to the base (400), and a spring c (401) is connected between the nozzle (105) and the base (400).

2. A hydraulic ejector according to claim 1, characterized in that: The injector body (100) comprises an upper shell (111) and a lower shell (112), the two being fastened together by threads, and the injection port a (104) is provided at the junction of the two.

3. A hydraulic ejector according to claim 2, characterized in that: A switching mechanism is provided between the piston (109) and the connecting plate (108), the switching mechanism comprising a limit bracket (200) connected to the outer wall of the pressure pipe (103), two transverse rods (201) being slidably connected to the limit bracket (200), a vertical rod a (202) being connected to the bottom of the piston (109), one end of the vertical rod a (202) extending into the cavity between the pressure pipe (103) and the injector body (100), and being rotatably connected to a connecting rod a (203), the connecting rod a (203) The other end of is rotatably connected to the transverse rod (201), the transverse rod (201) is also rotatably connected to a connecting rod b (204), one end of the connecting rod b (204) is rotatably connected to a vertical rod b (205), a switching frame (206) is provided on the top of the vertical rod b (205), a clamping piece (207) is provided on the switching frame (206), a side wall of the connecting plate (108) is provided with a plurality of clamping grooves (208) adapted to the clamping piece (207), and a spring a (209) is connected between the two transverse rods (201).

4. A hydraulic ejector according to claim 3, characterized in that: The clamping piece (207) is slidably connected to the switching frame (206), and a spring b (210) is connected between the clamping piece and the switching frame (206).

5. A hydraulic ejector according to claim 4, characterized in that: The switching mechanism further comprises a gear a (300) arranged on the nozzle (105), a ratchet mechanism being arranged between the gear a (300) and the nozzle (105), a slide rail a (301) being connected to the connecting ring (106), the slide rail a (301) comprising an inclined section opening (302) and a straight section opening (303), and a rack a (304) matching the gear a (300) being slidably connected to the slide rail a (301).

6. A hydraulic ejector according to claim 5, characterized in that: The switching mechanism is capable of rotating the spray head (105) before switching the spray head (105); The switching mechanism further comprises a guide cylinder (305) rotatably connected to the limit bracket (200); an outer wall of the guide cylinder (305) is provided with a spiral opening (306); a first section of the spiral opening (306) is provided with a straight section opening (307); a guide rod (308) corresponding to the straight section opening (307) is connected to the transverse rod (201); one end of the guide cylinder (305) is connected to a gear b (313); one side of the slide rail a (301) is connected to a slide rail b (310); a connecting frame (311) is slidably connected to the slide rail b (310); one end of the connecting frame (311) is connected to a rack b (309) meshing with the gear b (313); and the other end is connected to a telescopic rod (312); a telescopic shaft of the telescopic rod (312) is connected to the rack a (304).

7. A hydraulic ejector according to claim 3, characterized in that: The lower shell body (112) is provided with a connecting groove (402), an ejection frame (403) is slidably connected in the connecting groove (402), a spring d (404) is connected between the ejection frame (403) and the connecting groove (402), a connecting rod c (405) is rotatably connected at the bottom of the ejection frame (403), a connecting rod a (406) is connected at the bottom of the connecting rod c (405), and a connecting rod b (407) is connected to the vertical displacement rod a (202) and extends into the connecting groove (402) and contacts the connecting rod a (406).

8. A hydraulic ejector according to claim 3, characterized in that: A connecting shaft (408) slidably connected to the vertical moving rod b (205) is connected to the bottom of the switching frame (206), and a spring e (409) is connected between the connecting shaft (408) and the vertical moving rod b (205).

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