A nozzle for detecting cleanliness of an oil injector and a detection method

Abstract

The present application relates to a kind of fuel injector cleanliness detection oil nozzle and detection method.The present application includes after being cleaned in fuel injector cleanliness detection oil nozzle, the oil nozzle of the fuel injector assembly of the cleanliness to be measured is replaced by special oil nozzle for cleanliness detection;The replaced fuel injector is connected to special test test bench and works, after the fuel injector starts to work, start sampling;In the high-pressure diesel oil circuit of the fuel injector to be detected cleanliness, the test oil of predetermined volume is collected, in the low-pressure diesel loop of the fuel injector to be detected cleanliness, the test oil of predetermined volume is collected, the two kinds of test oil collected are the medium to be measured;The medium to be measured is filtered by filter paper, filter paper with particulate matter is placed in electric thermostat, and drying is carried out;Impurities and particulate matter are detected to filter paper after drying using measuring magnifying glass.The present application can more accurately collect the particle greater than nozzle diameter existing in the inside of fuel injector, effectively detects the real cleanliness condition in the inside of fuel injector assembly.

Description

Technical Field

[0001] This invention relates to the field of fuel injection technology, and in particular to a fuel injector nozzle and a testing method for testing the cleanliness of fuel injectors. Background Technology

[0002] The cleanliness of fuel injectors affects their performance, which in turn affects engine performance. Traditional cleanliness measurement methods directly collect the fuel ejected from the nozzle. However, due to limitations in nozzle diameter and needle valve lift, particles larger than the nozzle diameter cannot be effectively collected and detected. Currently, fuel injector cleanliness testing typically involves disassembling the injector and inspecting each component individually. This process is cumbersome, and disassembling the injector can easily lead to particulate contamination, making it difficult to obtain a true assessment of the cleanliness level inside the injector body. Summary of the Invention

[0003] Therefore, the present invention provides a nozzle and method for testing the cleanliness of fuel injectors. By replacing the original nozzle in the fuel injector assembly with this nozzle, it is possible to more accurately collect particles larger than the nozzle diameter inside the fuel injector and effectively detect the true cleanliness of the fuel injector assembly.

[0004] To solve the above-mentioned technical problems, the present invention provides an injector nozzle for testing injector cleanliness, comprising:

[0005] The first needle valve body is provided with a first needle valve body cavity, and the bottom end of the first needle valve body cavity has a first sealing seat and an oil injection opening end;

[0006] The first piston needle valve forms a clearance fit with the first needle valve body cavity. The head of the first piston needle valve is sealed to the first sealing seat. When the two are sealed together, the head of the first piston needle valve and the first sealing seat form a first sealing intersection line. The minimum diameter of the oil injection opening end is smaller than the diameter of the first sealing intersection line. The minimum diameter of the oil injection opening end is larger than the nozzle diameter of the oil injector assembly of the oil injector to be tested for cleanliness.

[0007] In one embodiment of the present invention, the head of the first piston needle valve is sealed to the first sealing seat via a conical surface.

[0008] The present invention also provides a method for detecting the cleanliness of fuel injectors, using the aforementioned fuel injector cleanliness detection nozzle;

[0009] The method includes:

[0010] After the nozzle for testing the cleanliness of the injector is cleaned, the nozzle of the injector assembly of the injector to be tested is replaced with the nozzle for testing the cleanliness, and the piston needle valve lift is increased to the upper limit of the particulate matter size assessment by thickening the adjusting shim.

[0011] Connect the replaced injector to the dedicated test bench and drive the test bench to work. After the injector is working, start sampling.

[0012] A predetermined volume of test oil is collected from the high-pressure diesel fuel circuit of the injector whose cleanliness is to be tested, and a predetermined volume of test oil is also collected from the low-pressure diesel fuel circuit of the injector whose cleanliness is to be tested. The two types of test oil collected are the test medium.

[0013] The test medium is filtered through filter paper, and then the filter paper containing impurities and particles is placed in an electric constant temperature oven and dried at a predetermined temperature.

[0014] The dried filter paper was tested for impurities and particulate matter using a measuring magnifying glass.

[0015] In one embodiment of the present invention, the injector assembly nozzle for which the cleanliness is to be tested includes:

[0016] The second needle valve body is provided with a second needle valve body cavity, and the bottom end of the second needle valve body cavity has a second sealing seat;

[0017] The second piston needle valve has the same structure as the first piston needle valve and forms a clearance fit with the cavity of the second needle valve body. The head of the second piston needle valve is sealed to the second sealing seat. When the two are sealed to each other, the head of the second piston needle valve and the second sealing seat form a second sealing intersection line. The head of the second needle valve body is provided with a spray hole.

[0018] In one embodiment of the present invention, the nozzle of the injector assembly of the injector whose cleanliness is to be tested is replaced with the nozzle specifically for cleanliness testing, that is, the second needle valve body is replaced with the first needle valve body.

[0019] In one embodiment of the present invention, when the injector is working, a predetermined volume of test oil is collected from the low-pressure return oil passage.

[0020] In one embodiment of the present invention, a predetermined volume of test oil is collected from the oil injection opening end of the head of the first piston needle valve.

[0021] The technical solution of the present invention has the following advantages compared with the prior art:

[0022] The present invention discloses an injector cleanliness testing nozzle and testing method. Without the need to disassemble and inspect all components of the injector one by one, the injector cleanliness testing nozzle can more accurately collect particles larger than the nozzle diameter inside the injector assembly. The presence of particles can be further detected by filter paper and measuring magnifying glass, making it simpler and more effective to detect the true cleanliness of the injector assembly.

[0023] The injector cleanliness testing nozzle of the present invention has a simple testing process. It only requires a series of steps such as nozzle replacement, sampling, filtering, drying and testing to complete the tedious cleanliness testing work. It avoids the problems of tedious steps and easy particulate contamination caused by traditional disassembly and testing, as well as the problem that large-sized impurities and particles cannot be effectively collected when the injector assembly is directly tested for cleanliness due to the limitation of nozzle diameter.

[0024] The injector nozzle and testing method for injector cleanliness testing of the present invention can be applied to the cleanliness testing of different types of injectors by replacing different types of nozzles, and has strong applicability and scalability. Attached Figure Description

[0025] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0026] Figure 1 This is a schematic diagram of the nozzle structure for testing the cleanliness of the injector according to the present invention.

[0027] Figure 2 This is a schematic diagram of the injector structure to be tested for cleanliness.

[0028] Figure 3 This is a schematic diagram of sampling for fuel injector assembly cleanliness testing.

[0029] Explanation of reference numerals in the instruction manual:

[0030] 1. First needle valve body; 1a. First needle valve body cavity; 1b. First sealing seat; 1c. Fuel injection opening end;

[0031] 2. First piston needle valve; 2a. First sealing intersection line;

[0032] 4. Injector body; 4a. High-pressure fuel inlet;

[0033] 5. Second needle valve body; 5a. Second needle valve body cavity; 5b. Second sealing seat; 5c. Spray hole;

[0034] 6. Second piston needle valve; 6a. Second sealing line;

[0035] 7. Piston sleeve; 8. Needle valve spring; 9. Inlet valve seat; 9a. Inlet throttle orifice; 10. Return valve seat; 10a. Return throttle orifice; 11. Control valve; 12. Armature; 13. Solenoid valve; 14. Solenoid valve spring; 15. Low-pressure return oil passage; 16. Adjusting shim. Detailed Implementation

[0036] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0037] In this invention, when directions (up, down, left, right, front, and back) are described, it is only for the convenience of describing the technical solution of this invention, and does not indicate or imply that the technical features referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this invention.

[0038] In this invention, "several" means one or more, "multiple" means two or more, "greater than," "less than," "exceeding," etc., are understood to exclude the stated number; "above," "below," "within," etc., are understood to include the stated number. In the description of this invention, the terms "first" and "second" are used only to distinguish technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0039] In this invention, unless otherwise explicitly defined, the terms "setting," "installing," and "connecting" should be interpreted broadly. For example, they can refer to a direct connection or an indirect connection through an intermediate medium; a fixed connection, a detachable connection, or an integrally formed connection; a mechanical connection, an electrical connection, or a connection capable of mutual communication; or the internal connection of two components or the interaction between two components. Those skilled in the art can reasonably determine the specific meaning of the above terms in this invention based on the specific content of the technical solution.

[0040] Reference Figure 1 As shown, an injector cleanliness testing nozzle of the present invention includes:

[0041] The first needle valve body 1 is provided with a first needle valve body cavity 1a, and the bottom end of the first needle valve body cavity 1a has a first sealing seat 1b and an oil injection opening end 1c.

[0042] The first piston needle valve 2 forms a clearance fit with the first needle valve body cavity 1a. The head of the first piston needle valve 2 is sealed with the first sealing seat 1b. When the two are sealed together, the head of the first piston needle valve 2 and the first sealing seat 1b form a first sealing intersection line 2a. The minimum diameter of the oil injection opening end 1c is smaller than the diameter of the first sealing intersection line 2a. The minimum diameter of the oil injection opening end 1c is larger than the diameter of the nozzle 5c of the injector assembly of the oil injector to be tested for cleanliness.

[0043] Specifically, the head of the first piston needle valve 2 is sealed to the first sealing seat 1b via a conical surface.

[0044] Reference Figure 2 and Figure 3 As shown, a method for testing the cleanliness of fuel injectors utilizes the aforementioned fuel injector cleanliness testing nozzle; the method includes:

[0045] S1. After the nozzle for testing the cleanliness of the injector is cleaned, the nozzle of the injector assembly of the injector to be tested is replaced with the nozzle for testing the cleanliness, and the piston needle valve lift is increased to the upper limit of the particle size assessment by thickening the adjusting shim.

[0046] S2. Connect the replaced injector to the dedicated test bench and drive the test bench to work. After the injector is working, start sampling.

[0047] S3. Collect a predetermined volume of test oil in the high-pressure diesel oil circuit of the injector whose cleanliness is to be tested, and similarly collect a predetermined volume of test oil in the low-pressure diesel oil circuit of the injector whose cleanliness is to be tested. The two types of test oil collected are the test medium.

[0048] S4. Filter the medium to be tested through filter paper, and then put the filter paper containing impurities and particles into an electric constant temperature oven to dry it at a predetermined temperature.

[0049] S5. Use a measuring magnifying glass to detect impurities and particulate matter on the dried filter paper. The detection using filter paper and a magnifying glass provides reliable results and accurately detects particulate matter inside the fuel injector.

[0050] In some embodiments, the injector assembly nozzle for which the cleanliness is to be tested includes:

[0051] The second needle valve body 5 is provided with a second needle valve body cavity 5a, and the bottom end of the second needle valve body cavity 5a has a second sealing seat 5b.

[0052] The second piston needle valve 6 has the same structure as the first piston needle valve 2 and forms a clearance fit with the cavity 5a of the second needle valve body. The head of the second piston needle valve 6 is sealed to the second sealing seat 5b. When the two are sealed to each other, the head of the second piston needle valve 6 and the second sealing seat 5b form a second sealing intersection line 6a. The head of the second needle valve body 5 is provided with a spray hole 5c.

[0053] Specifically, the nozzle of the injector assembly whose cleanliness is to be tested is replaced with the nozzle used for cleanliness testing, which specifically involves replacing the second needle valve body 5 with the first needle valve body 1.

[0054] The injector for which cleanliness is to be tested can adopt any publicly disclosed injector structure, such as the structure of patent CN212690213U. In some embodiments, the injector for which cleanliness is to be tested includes:

[0055] The injector body 4 has a return valve seat 10 installed on its top and a high-pressure oil inlet 4a opened on its side. The upper end face of the second needle valve body 5 is sealed to the lower end face of the adjusting shim 16, and the upper end face of the adjusting shim 16 is sealed to the lower end face of the injector body 4.

[0056] The upper end of the second piston needle valve 6 is fitted with a piston sleeve 7. An oil inlet valve seat 9 is installed between the piston sleeve 7 and the oil return valve seat 10. The oil inlet valve seat 9 has a horizontally arranged oil inlet throttle hole 9a. The distance from the top of the piston needle valve 6 to the lower end face of the oil inlet valve seat 9 is the piston needle valve lift. The second piston needle valve 6 is fitted with a needle valve spring 8 that is pressed and contacted with the piston sleeve 7.

[0057] The return oil valve seat 10 is provided with a return oil throttling orifice 10a. The control valve 11 dynamically seals the outlet end of the return oil throttling orifice 10a. An armature 12 is provided above the control valve 11. A solenoid valve 13 is provided above the armature 12. A low-pressure return oil passage 15 is provided above the solenoid valve 13. A solenoid valve spring 14 is placed in the middle of the solenoid valve 13. The lower end face of the solenoid valve spring 14 is in contact with the upper end face of the armature 12.

[0058] Specifically, a predetermined volume of test oil is collected from the low-pressure return oil channel 15.

[0059] Specifically, a predetermined volume of test oil is collected from the oil injection opening end 1c of the first piston needle valve 2 head of the cleanliness testing nozzle.

[0060] The injector cleanliness testing nozzle of the present invention can more accurately collect particles larger than 5c in diameter inside the injector. The presence of impurities and particles can be further detected by filter paper and measuring magnifying glass. Without the need to disassemble and inspect all components of the injector, the true cleanliness of the injector assembly can be effectively detected. This avoids the problems of cumbersome steps and easy particle contamination caused by traditional disassembly and testing, as well as the problem that large impurities and particles cannot be effectively collected when directly testing the cleanliness of the injector assembly due to the limitation of nozzle diameter.

[0061] Finally, it should be noted that the above specific embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for detecting the cleanliness of fuel injectors, characterized in that, Injector cleanliness testing nozzles are used; injector cleanliness testing nozzles include: The first needle valve body (1) is provided with a first needle valve body cavity (1a), and the bottom end of the first needle valve body cavity (1a) has a first sealing seat (1b) and an oil injection opening end (1c). The first piston needle valve (2) forms a clearance fit with the first needle valve body cavity (1a). The head of the first piston needle valve (2) is sealed with the first sealing seat (1b). When the two are sealed together, the head of the first piston needle valve (2) and the first sealing seat (1b) form a first sealing intersection line (2a). The minimum diameter of the oil injection opening end (1c) is smaller than the diameter of the first sealing intersection line (2a). The minimum diameter of the oil injection opening end (1c) is larger than the diameter of the nozzle (5c) of the oil injector assembly of the oil injector to be tested for cleanliness. The method includes: After the nozzle for testing the cleanliness of the injector is cleaned, the nozzle of the injector assembly of the injector to be tested is replaced with the nozzle for testing the cleanliness, and the piston needle valve lift is increased to the upper limit of the particulate matter size assessment by thickening the adjusting shim. Connect the replaced injector to the dedicated test bench and drive the test bench to work. After the injector is working, start sampling. A predetermined volume of test oil is collected from the high-pressure diesel fuel circuit of the injector whose cleanliness is to be tested, and a predetermined volume of test oil is also collected from the low-pressure diesel fuel circuit of the injector whose cleanliness is to be tested. The two types of test oil collected are the test medium. The test medium is filtered through filter paper, and then the filter paper containing impurities and particulate matter is placed in an electric constant temperature oven and dried at a predetermined temperature. The dried filter paper was tested for impurities and particulate matter using a measuring magnifying glass.

2. The method for detecting injector cleanliness according to claim 1, characterized in that, The head of the first piston needle valve (2) is sealed to the first sealing seat (1b) by a conical surface.

3. The injector cleanliness detection method as described in claim 1, characterized in that, The injector assembly nozzle of the injector whose cleanliness is to be tested includes: The second needle valve body (5) is provided with a second needle valve body cavity (5a), and the bottom end of the second needle valve body cavity (5a) has a second sealing seat (5b). The second piston needle valve (6) has the same structure as the first piston needle valve (2) and forms a clearance fit with the cavity (5a) of the second needle valve body. The head of the second piston needle valve (6) is sealed to the second sealing seat (5b). When the two are sealed to each other, the head of the second piston needle valve (6) and the second sealing seat (5b) form a second sealing intersection line (6a). The head of the second needle valve body (5) is provided with a spray hole (5c).

4. The injector cleanliness detection method as described in claim 3, characterized in that, Replace the nozzle of the injector assembly of the injector whose cleanliness is to be tested with the nozzle for cleanliness testing, specifically by replacing the second needle valve body (5) with the first needle valve body (1).

5. A method for detecting the cleanliness of an injector according to any one of claims 1 to 4, characterized in that, When the injector is working, a predetermined volume of test oil is collected from the low-pressure circuit of the injector.

6. A method for detecting the cleanliness of an injector according to any one of claims 1 to 4, characterized in that, A predetermined volume of test oil is collected from the injection opening end (1c) of the first needle valve body (1) of the injector cleanliness test nozzle.

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