Self-powered oil mixing and cutting device

Abstract

The present invention discloses a self-powered mixed oil cutting device, which belongs to the technical field of oil pipelines and mainly solves the problem of automatic cutting of mixed oil during sequential transportation of mobile oil pipelines. After the device of the present invention performs density identification on the pipeline oil product through a density control pilot valve, it controls the main valve to open the corresponding channel output to ensure that the oil products within a specific density range can be output to the correct oil storage area through a specific channel. The device can improve the convenience and safety of mobile pipeline oil transportation. When the oil is transported sequentially through the pipeline, the device is mainly used for automatic cutting of the oil at the mobile oil pipeline terminal and the fixed pipeline oil download station terminal, and can also be used in oil depots to prevent errors in oil entering the tank due to misoperation.

Description

Technical Field

[0001] The invention relates to the technical field of oil pipelines, in particular to a self-powered mixed oil cutting device. Background Art

[0002] Pipeline sequential transportation is the main transportation process of long-distance pipelines. Its basic requirements are to reduce the amount of mixed oil and ensure the quality of oil products. The key issues are mixed oil interface detection and terminal mixed oil cutting.

[0003] At present, all domestic and foreign civil refined oil pipelines are fixed pipeline systems. Through the automatic detection-automatic control-power execution automation system, the automatic cutting of mixed oil in sequential transportation is realized. For example, the Colonial refined oil pipeline in the United States installs and uses the KAM (OID) optical interface detector produced by Kam Control Company of the United States at each sub-transmission station and terminal station to accurately detect the mixed oil interface according to the different refractive indices of different oil products. The automatic control system automatically analyzes the detection results of the mixed oil interface, accurately determines the concentration of the mixed oil, and automatically switches the corresponding valve according to the set operating procedures to complete the automatic cutting of the mixed oil. my country's Lanchengyu pipeline installs and uses a high-precision (up to one ten-thousandth) vibration mixed oil interface detection system at each sub-transmission station and terminal station. According to the mass change and liquid density change when a certain volume of liquid flows through a specific vibration tube, the mixed oil interface is accurately detected. Its automatic control system automatically analyzes the detection results of the mixed oil interface, accurately determines the concentration of the mixed oil, and automatically switches the corresponding valve according to the set operating procedures to complete the automatic cutting of the mixed oil. These methods and systems have high measurement and control accuracy and good real-time performance, but their structures are delicate and complex, and their prices are as high as hundreds of thousands or even millions of yuan. They require external energy and have strict requirements on the conditions of use. They are not suitable for use on field mobile pipelines in harsh operating environments and with changing conditions.

[0004] At present, my country uses two methods to measure the mixed oil in the sequential transportation of field mobile pipelines: automatic detection by ultrasonic oil interface detector and manual measurement by oil density meter. Then the cutting point is calculated and determined according to the test results, and finally the operator coordinates and cooperates to open and close the valve to complete the mixed oil cutting. At present, there is no relevant technology for automatic cutting of mixed oil in the sequential transportation of field mobile pipelines.

[0005] In addition to expensive automatic detection equipment such as optical interface detectors and ultrasonic oil interface detectors and relatively inefficient manual measurement methods, there is also an oil density sensitive on-off control valve in the prior art, such as Figure 1As shown, this valve adopts the pilot control principle, mechanical detection, and self-actuation. When the oil density deviates from the preset value range, the main valve 1' will automatically close. This control valve cannot switch the preset oil density in real time as needed. This is because the float 24' in its pilot valve 2' is not loaded and is a free float. In other words, after the float 24' is installed, the oil density it controls has been determined. If the preset oil density needs to be changed, the float 24' must be taken out, replaced or re-weighted, and installed again to achieve the desired control effect; in addition, once the main valve 1' of this control valve is automatically closed, it must be manually reset, which is cumbersome to use. Therefore, this oil density-sensitive on-off control valve is currently only used in large fixed oil depots. It is difficult to adapt to the needs of field mobile pipelines to sequentially transport mixed oil, and the user end needs to adjust the density of the required oil in real time on site. It cannot meet the needs of convenient operation in this case. Summary of the invention

[0006] In view of this, the present invention provides a self-powered mixed oil cutting device, which uses a purely mechanical mechanism to automatically sense and detect the mixed oil interface, and at the same time relies on the liquid pressure of the oil transported by the pipeline to automatically complete the switch switching of the actuator, thereby realizing automatic cutting of the mixed oil transported sequentially by the motor pipeline.

[0007] The technical solution to solve the above technical problems is: a self-powered mixed oil cutting device, comprising: a density control pilot valve 2, used to set the oil density value as needed; a control pipeline, one end of which is connected to the density control pilot valve 2, and the other end is connected to the controlled main valve 1, and the density control pilot valve 2 opens or closes the control pipeline according to the set oil density value; the inlet of the controlled main valve 1 is connected to the oil main pipe 3, and the control pipeline controls the switch of the main valve core, and the oil that meets the set oil density value flows out from the outlet of the controlled main valve 1.

[0008] The preferred solution is: the controlled main valve 1 includes a light oil valve 11 and a heavy oil valve 12, the inlets of the light oil valve 11 and the heavy oil valve 12 are connected in parallel to the oil main pipe 3, the outlet of the light oil valve 11 is the light oil outlet A, and the outlet of the heavy oil valve 12 is the heavy oil outlet B; the light oil valve 11 and the heavy oil valve 12 cannot be opened at the same time.

[0009] The preferred solution is: the density control pilot valve 2 adopts a float-pushed pilot valve spring-reset slide valve structure, and the slide valve structure has two limit positions, which are position I and position II; when the slide valve structure is in position I, the control pipeline controls the light oil valve 11 to open, and the heavy oil valve 12 to close; when the slide valve structure is in position II, the control pipeline controls the heavy oil valve 12 to open, and the light oil valve 11 to close.

[0010] The preferred solution is: the slide valve structure includes a pilot valve core 21 and a pilot valve spring 22 , the spring force of the pilot valve spring 22 is determined by the set oil density value, and acts on one end of the pilot valve core 21 .

[0011] The preferred solution is: the density control pilot valve 2 includes: a density setting handle 23, which is used to set the oil density value; a float 24, which is connected to the oil main pipe 3 with a sampling pipeline 26, and the oil in the oil main pipe flows into the float through the sampling pipeline 26; the float 24 is coupled to the pilot valve core 21, and the buoyancy of the oil carried by the float is transmitted to the other end of the pilot valve core 21; the two ends of the pilot valve core 21 are moved by force, so that the sliding valve structure is balanced to the limited position.

[0012] The preferred solution is that the control pipeline includes: a light oil control pipeline P1A1 and a heavy oil control pipeline P2A2. When the sliding valve structure is in position I, the light oil control pipeline P1A1 is connected to the light oil valve 11 to open the light oil valve 11; when the sliding valve structure is in position II, the heavy oil control pipeline P2A2 is connected to the heavy oil valve 12 to open the heavy oil valve 12.

[0013] The preferred solution is that the float 24 includes a float ball 242 and a shell, the shell has a containing space 241 , and the float ball 242 is placed in the containing space 241 ; the oil flowing into the containing space 241 through the sampling connecting pipeline 26 provides buoyancy to the float ball 242 .

[0014] The preferred solution is that the coupling connection between the float 24 and the pilot valve core 21 is specifically as follows: the float 242 and the pilot valve core 21 adopt a linkage structure coupled by a connecting rod, and the pilot valve core 21 adopts a round head structure at the contact point with the end of the connecting rod.

[0015] The preferred solution is that the coupling connection between the float 24 and the pilot valve core 21 is specifically that the float 242 and the pilot valve core 21 adopt a linkage structure coupled by a connecting rod, and the pilot valve core 21 adopts a roller structure at the contact point with the end of the connecting rod.

[0016] The preferred solution is that the coupling connection between the float 24 and the pilot valve core 21 is specifically that the float 242 and the pilot valve core 21 adopt a direct connection structure.

[0017] By means of the above technical solution, the beneficial effects provided by the present invention are as follows:

[0018] (1) The density control pilot valve can be used to flexibly and conveniently set the oil density value according to the needs. After the density of the oil in the oil pipeline is identified, the main valve is controlled to open the corresponding channel output to ensure that the oil within a specific density range can be output to the correct oil storage area through the corresponding channel.

[0019] (2) The density control pilot valve adopts a float-pushing pilot valve spring-reset slide valve structure. The two ends of the slide valve structure are respectively subjected to the buoyancy of the incoming oil and the spring force of the pilot valve spring, and balance is achieved at two pre-set limit positions, which correspond to the light oil valve and the heavy oil valve respectively. With this structure, the self-powered mixed oil cutting device can automatically switch the light oil valve and the heavy oil valve according to the change of the incoming oil density.

[0020] (3) Heavy oil and light oil flow out through different valve flow paths, which can solve the problem in the prior art that once the main valve is closed, the oil in the pilot valve is retained in the flow path and cannot be replaced, requiring manual reset.

[0021] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented according to the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Moreover, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0023] Figure 1 It is a structural schematic diagram of a prior art oil density sensitive on-off control valve;

[0024] Figure 2 It is a structural schematic diagram of a self-powered oil-mixing cutting device according to the present invention;

[0025] Figure 3 It is a structural schematic diagram of a density control handle of a self-powered oil mixing cutting device according to the present invention;

[0026] Figure 4 It is a schematic diagram of a front cross-section of a self-powered oil-mixing cutting device according to the present invention;

[0027] Figure 5 This is a left-side cross-sectional schematic diagram of a self-powered oil-mixing cutting device according to the present invention:

[0028] Figure 6 It is a top cross-sectional schematic diagram of a density control pilot valve of a self-powered oil mixing cutting device described in Example 3 of the present invention. DETAILED DESCRIPTION

[0029] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0030] The present invention will be further described below in conjunction with the accompanying drawings:

[0031] Example 1

[0032] like Figure 2-Figure 3 As shown, a first embodiment of the present invention provides a self-powered oil mixing cutting device, comprising a controlled main valve 1 and a density control pilot valve 2 connected to the controlled main valve 1 through a control pipeline.

[0033] One end of the controlled main valve 1 is connected to the oil main pipe 3, and the other end of the oil outlet is connected to the oil storage device. Two oil outlet valves are arranged in the middle of the controlled main valve 1, one of which is a light oil valve 11 and the other is a heavy oil valve 12. The oil inlets P of the light oil valve 11 and the heavy oil valve 12 are connected to the oil main pipe 3 in parallel. The oil outlet of the light oil valve is the light oil outlet A, and the oil outlet of the heavy oil valve 12 is the heavy oil outlet B.

[0034] Figure 4 FIG. 1 is a schematic diagram of a front cross-section of a self-powered oil mixing cutting device according to the present invention, as shown in FIG. Figure 4 As shown, a control line P1A1 is connected between the light oil valve 11 and the density control pilot valve 2, wherein P1 is a drainage port and A1 is a drain port; a light oil valve spool 111 is arranged inside the light oil valve 11, and when the control line P1A1 is connected, the light oil valve spool 111 will open the light oil valve passage due to balanced front and rear forces; a control line P2A2 is connected between the heavy oil valve 12 and the density control pilot valve 2, wherein P2 is a drainage port and A2 is a drain port; a heavy oil valve spool 112 is arranged inside the heavy oil valve 12, and when the control line P2A2 is connected, the heavy oil valve spool 112 will open the heavy oil valve passage due to balanced front and rear forces. In the initial state, when the control lines P1A1 and P2A2 are not connected, the pressure in front of the light oil valve core is greater than the pressure behind the light oil valve core, the light oil valve core will move backward and block the light oil passage; the pressure in front of the heavy oil valve core is greater than the pressure behind the heavy oil valve core, the heavy oil valve core will move backward and block the heavy oil passage.

[0035] Figure 5 FIG. 1 is a schematic diagram of a left cross-sectional view of a self-powered oil mixing cutting device according to the present invention, as shown in FIG. Figure 5 As shown:

[0036] The density control pilot valve 2 includes a density setting handle 23, which is used to set the current required oil density value. The handle is provided with scale values, which can be rotated to the required scale by rotating the handle, or pushed inward or pulled out to set to the required scale. The setting method can be determined according to the usage habits of the product.

[0037] The density control pilot valve 2 adopts a float-pushing pilot valve spring-reset slide valve structure, and the slide valve structure has two limiting positions, namely position I and position II; when the slide valve structure is in position I, the control pipeline controls the light oil valve 11 to open, and the heavy oil valve 12 to close; when the slide valve structure is in position II, the control pipeline controls the heavy oil valve 12 to open, and the light oil valve 11 to close. The slide valve structure includes a pilot valve core 21 and a pilot valve spring 22.

[0038] The density setting handle is coupled to one end of the pilot valve spring 22, so that the set density value corresponds to the spring force of the pilot valve spring 22. For example, when the set density value is large, the spring force of the pilot valve spring 22 increases accordingly; when the set density value is small, the spring force of the pilot valve spring 22 decreases accordingly. The other end of the pilot valve spring 22 is coupled to the pilot valve core 21, and the spring force of the pilot valve spring 22 acts on one end of the pilot valve core 21.

[0039] The density control pilot valve 2 also includes a float 24, which is connected to the oil inlet P of the controlled main valve 1 through a sampling pipeline 26; the float 24 has a shell, and a sampling port CY and an overflow port YL are arranged on the shell; the sampling port CY is where the sampling pipeline 26 is connected to the shell; the shell is hollow inside a housing space 241, and the oil in the oil main pipe flows from the sampling pipeline 26 into the internal housing space 241 of the float 24. When there is too much oil and the housing space 241 cannot accommodate it, the excess oil overflows through the overflow port YL. A floating ball 242 is arranged in the housing space 241, and the floating ball 242 is connected to the other end of the pilot valve core through a connecting rod, and the buoyancy of the sampled oil on the floating ball 242 is transmitted to the pilot valve core, so that one end of the pilot valve core 21 is acted upon by the spring force of the pilot valve spring 22, and the other end arranged oppositely is acted upon by the buoyancy of the sampled oil. At the connection between the end of the connecting rod and the pilot valve core, the pilot valve core adopts a round head structure, and the pilot valve core 21 moves under the action of forces at both ends. When the pilot valve core 21 moves to the I position balance under the action of forces at both ends, the control pipeline P1A1 is connected and the control pipeline P2A2 is closed. At this time, the light oil valve passage is opened and the heavy oil valve passage is closed; when the pilot valve core 21 moves to the II position balance under the action of forces at both ends, the control pipeline P2A2 is connected and the control pipeline P1A1 is closed. At this time, the heavy oil valve passage is opened and the light oil valve passage is closed.

[0040] The float 24 is also provided with an automatic exhaust device 25 , which is used to exhaust the gas escaping from the oil product and reduce the influence of the gas on the float 242 .

[0041] After testing, the detection and control accuracy of the design of this embodiment 1 is ≤5%, that is: when the density setting handle 23 is set to 0.74, the density of the oil flowing through the light oil valve P and A channels is less than 0.75g / cm3 (i.e., it is identified as gasoline), and the density of the oil flowing through the heavy oil valve P and B channels is ≥0.75g / cm3 (i.e., it is identified as mixed oil); when the density setting handle 23 is set to 0.81, the density of the oil flowing through the light oil valve P and A channels is less than 0.82, and the density of the oil flowing through the heavy oil valve P and B channels is ≥0.82.

[0042] Example 2

[0043] The second embodiment of the self-powered mixed oil cutting device of the present invention includes a controlled main valve 1 and a density control pilot valve 2 connected to the controlled main valve 1 through a control pipeline. The difference from the first embodiment lies in the connection method between the float 242 and the pilot valve core. In the first embodiment, the float 242 is connected to the other end of the pilot valve core through a connecting rod. At the connection between the end of the connecting rod and the pilot valve core, when the pilot valve core adopts a round head structure, the friction force is large when the connecting rod drives the pilot valve core to move, which has a certain influence on the stability of the pilot valve control. This embodiment is further optimized by adding a roller to the head of the pilot valve core to reduce the influence of friction. Further experiments show that when the oil density value is set by rotating the density setting handle, a density difference of 20kg / m3 can be identified.

[0044] Example 3

[0045] The third embodiment of the self-operated oil mixing cutting device of the present invention comprises a controlled main valve 1 and a density control pilot valve 2 connected to the controlled main valve 1 through a control pipeline. The difference from the first and second embodiments is that the float 242 and the pilot valve core are directly connected. Figure 6 As shown, specifically, at this time, the float is directly connected to the pilot valve core, and when the float moves up and down due to the buoyancy, it will drive the pilot valve core to move together. The structure of the pilot valve enables one end of the pilot valve core to directly obtain the buoyancy of the sampled oil on the float 242. In Example 1, the float 242 and the pilot valve core transmit buoyancy through a connecting rod, or in Example 2, the float 242 and the pilot valve core transmit buoyancy through a connecting rod and a roller. The flexibility of the connecting rod and the friction of the connection part will affect the detection accuracy. The direct connection structure in this embodiment does not need to transmit buoyancy through a connecting rod (Example 1) or a connecting rod and a roller (Example 2), reducing the influence of the intermediate components on the accuracy. Further experiments show that when the oil density value is set by rotating the density setting handle, a density difference of 10kg / m3 can be identified.

[0046] Experimental studies have shown that when the second and third embodiments of the self-powered oil mixing cutting device of the present invention are used, the oil density difference of 10 to 20 kg / m3 can be identified. For example, based on the typical density values ​​of gasoline and diesel of 740 kg / m3 and 830 kg / m3, the detection accuracy is ±1.35% to ±2.7% and ±1.21% to ±2.41% respectively, which can meet the accuracy requirements for the use of field mobile pipelines.

[0047] When the self-powered oil-mixing cutting device of the present invention is used:

[0048] When the density setting handle 23 is set to 0.74g / cm3, if the incoming oil density is lower than the handle setting value (such as gasoline, etc.), and the range is ≤0.73g / cm3, the sampling buoyancy of the float on the medium density and the pilot valve spring reach a balance so that the slide valve structure is in position I, the control pipeline P1 is connected to A1, and then the main valve P and A channels are opened, the main valve P and B channels are in a closed state, and the main pipelines P and A are connected, that is, the incoming oil with a density of ≤0.73g / cm3 is sent from port P to port A for output; if the incoming oil density is greater than the handle setting value (such as a mixed oil or diesel formed by gasoline and diesel), and the density is ≥0.75g / cm3, the float sampling buoyancy change controls the slide valve structure to be in position II, the control pipeline P2 is connected to A2, and then the main valve P and B channels are opened, the main valve P and A channels are closed, and the main pipelines P and B are connected, that is, the incoming oil with a density of ≥0.75g / cm3 is sent from port P to port B for output.

[0049] When the handle setting value is 0.81g / cm3, if the incoming oil density is lower than the handle setting value (such as gasoline or a mixture of gasoline and diesel), and the density is ≤0.80g / cm3, the sampling buoyancy of the float on the incoming oil density reaches a balance with the pilot valve spring, so that the slide valve structure is in position I, and the control pipeline P1 is connected to A1, and then the main valve P and A channels are opened, the main valve P and B channels are in a closed state, and the main pipelines P and A are connected, that is, the incoming oil with a density of ≤0.80g / cm3 is sent from port P to port A for output; if the density of the fluid medium is greater than the handle setting value (such as diesel, water), and the density is ≥0.82g / cm3, the float sampling buoyancy change controls the slide valve structure to be in position II, and the control pipeline P2 is connected to A2, and then the main valve P and B channels are opened, the main valve P and A channels are closed, and the main pipelines P and B are connected, that is, the medium with a density of ≥0.82g / cm3 is sent from port P to port B for output.

[0050] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0051] It is understandable that the related features in the above methods and devices can be referenced to each other. In addition, the "first", "second" and the like in the above embodiments are used to distinguish the embodiments, but do not represent the advantages and disadvantages of the embodiments.

[0052] In the description provided herein, a large number of specific details are described. However, it is understood that embodiments of the present invention can be practiced without these specific details. In some instances, well-known methods, structures and techniques are not shown in detail so as not to obscure the understanding of this description.

[0053] Similarly, it should be understood that in order to streamline the present invention and aid in understanding one or more of the various inventive aspects, in the above description of exemplary embodiments of the present invention, the various features of the present invention are sometimes grouped together into a single embodiment, figure, or description thereof. However, this disclosed method should not be interpreted as reflecting the following intention: that the claimed invention requires more features than the features explicitly recited in each claim. More specifically, as reflected in the claims below, inventive aspects lie in less than all the features of the individual embodiments disclosed above. Therefore, the claims that follow the specific embodiment are hereby expressly incorporated into the specific embodiment, with each claim itself serving as a separate embodiment of the present invention.

[0054] In addition, those skilled in the art will appreciate that, although some embodiments described herein include certain features included in other embodiments but not other features, the combination of features of different embodiments is meant to be within the scope of the present invention and form different embodiments. For example, in the claims below, any one of the claimed embodiments may be used in any combination.

Claims

1. A self-powered oil-mixing cutting device, characterized in that: include: Density control pilot valve (2), used to set the oil density value according to needs; A control pipeline, one end of which is connected to the density control pilot valve (2) and the other end of which is connected to the controlled main valve (1), wherein the density control pilot valve (2) opens or closes the control pipeline according to the set oil product density value; The inlet of the controlled main valve (1) is connected to the oil main pipe (3), and the switch of the main valve core is controlled by the control pipeline, so that the oil that meets the set oil density value flows out from the outlet of the controlled main valve (1); The controlled main valve (1) comprises a light oil valve (11) and a heavy oil valve (12); the inlets of the light oil valve (11) and the heavy oil valve (12) are connected in parallel to the oil main pipe (3); the outlet of the light oil valve (11) is a light oil outlet (A), and the outlet of the heavy oil valve (12) is a heavy oil outlet (B); the light oil valve (11) and the heavy oil valve (12) cannot be opened at the same time; The density control pilot valve (2) adopts a float-pushed pilot valve spring-reset slide valve structure, and the slide valve structure has two limiting positions, which are position I and position II. When the slide valve structure is in position I, the control pipeline controls the light oil valve (11) to open, while the heavy oil valve (12) is closed; when the slide valve structure is in position II, the control pipeline controls the heavy oil valve (12) to open, while the light oil valve (11) is closed. The slide valve structure comprises a pilot valve core (21) and a pilot valve spring (22), wherein the spring force of the pilot valve spring (22) is determined by the set oil product density value and acts on one end of the pilot valve core (21); The density control pilot valve (2) comprises: A density setting handle (23) is used to set the oil density value; The float (24) is connected to the oil main pipe (3) via a sampling pipeline (26), and the oil in the oil main pipe flows into the interior of the float through the sampling pipeline (26); The float (24) is coupled to the pilot valve core (21) to transmit the incoming oil buoyancy carried by the float to the other end of the pilot valve core (21); the two ends of the pilot valve core (21) are moved by force, so that the slide valve structure is balanced to the limited position; The control pipeline comprises: Light oil control line (P1A1), Heavy oil control line (P2A2), When the slide valve structure is in position I, the light oil control pipeline (P1A1) is connected to the light oil valve (11), and the light oil valve (11) is opened; when the slide valve structure is in position II, the heavy oil control pipeline (P2A2) is connected to the heavy oil valve (12), and the heavy oil valve (12) is opened.

2. The self-powered oil-mixing cutting device according to claim 1, characterized in that: The float (24) comprises a floating ball (242) and a shell, wherein the shell has a containing space (241), and the floating ball (242) is placed in the containing space (241); the oil product flowing into the containing space (241) through the sampling pipeline (26) provides buoyancy to the floating ball (242).

3. According to the self-powered mixed oil cutting device according to claim 2, the coupling connection between the float (24) and the pilot valve core (21) is specifically: the float (242) and the pilot valve core (21) adopt a linkage structure coupled by a connecting rod, and the pilot valve core (21) adopts a round head structure at the contact point with the end of the connecting rod.

4. According to the self-powered mixed oil cutting device of claim 2, the coupling connection between the float (24) and the pilot valve core (21) is specifically as follows: the float (242) and the pilot valve core (21) adopt a linkage structure coupled by a connecting rod, and the pilot valve core (21) adopts a roller structure at the contact point with the end of the connecting rod.

5. According to the self-powered mixed oil cutting device of claim 2, the coupling connection between the float (24) and the pilot valve core (21) is specifically: the float (242) and the pilot valve core (21) adopt a direct connection structure.

Images