A method for determining and eliminating the imbalance during engine testing.
By determining the engine imbalance through three test runs and drawing a circular diagram using the vector method, the problem of abnormal vibration during the overall engine test run was solved, achieving more efficient determination and elimination of imbalance and reducing production costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- AECC AVIATION POWER CO LTD
- Filing Date
- 2023-12-12
- Publication Date
- 2026-06-02
Smart Images
Figure CN117664445B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of engine whole machine testing technology, specifically relating to a method for determining and eliminating the imbalance during engine whole machine testing. Background Technology
[0002] After final assembly, the engine needs to be installed on a ground test stand for a full-engine test run to verify whether its assembly quality and performance level meet delivery requirements. Under current assembly technology, even engines assembled strictly according to assembly procedures and quality control requirements cannot guarantee that their vibration during the full-engine test run will meet acceptance requirements. A certain number of engines exhibit abnormal vibration, even significantly exceeding acceptance limits. Assembly imbalance is one of the main causes of abnormal engine vibration. If the problem of abnormal engine vibration cannot be completely resolved on the test stand, the entire engine needs to be disassembled, leading to extended production cycles, increased production costs, and reduced engine lifespan.
[0003] Currently, the three-circle method is commonly used to determine the engine's imbalance. Once the imbalance is determined, it is eliminated by appropriately positioning and massing counterweights at the engine's counterweight mounting holes, thus achieving overall engine balance. While this method can be performed on a test bench without requiring disassembly of the entire engine, reducing production cycle time and costs, it still requires four test runs to determine the engine's imbalance. This high number of tests continues to result in long production cycles and high production costs. Summary of the Invention
[0004] To address the problems existing in the prior art, this invention provides a method for determining and eliminating the imbalance during engine testing, aiming to solve the problems of numerous testing runs, long production cycles, and high production costs.
[0005] To solve the above-mentioned technical problems, the present invention is achieved through the following technical solution:
[0006] A method for determining the imbalance during engine testing includes:
[0007] The engine was tested for the first time to obtain the original vibration value. The first circle was drawn with the original vibration value as the radius.
[0008] After replacing the original counterweight at the first position on the engine with a counterweight of a set weight, a second test was conducted to obtain the first counterweight vibration value of the engine. A second circle was drawn with the first counterweight vibration value as the radius, and the second circle was concentric with the first circle.
[0009] After replacing the original counterweight at the first position on the engine with the original counterweight, and replacing the original counterweight at the second position on the engine with the counterweight of the set weight, a third test was conducted to obtain the second counterweight vibration value of the engine. A third circle was drawn with the second counterweight vibration value as the radius, and the third circle was concentric with the first circle.
[0010] Arbitrarily select a first point on the first circle to represent the first position, and denote the line connecting the first point and the center of the circle as the first reference line. Select a second point on the first circle to represent the second position, and denote the line connecting the second point and the center of the circle as the second reference line. The selection of the second point must satisfy the following condition: the angle between the first reference line and the second reference line is equal to the angle between the first position and the second position relative to the engine rotation axis.
[0011] Draw a first line segment that connects the first circle and the second circle and is parallel to the first reference line, and draw a second line segment that connects the first circle and the third circle and is parallel to the second reference line. When the first line segment and the second line segment are of equal length and intersect at a third point on the first circle, record the line connecting the third point and the center of the circle as the third reference line, and measure the angle between the third reference line and the first reference line.
[0012] The location of the engine imbalance is determined based on the angle between the third reference line and the first reference line. The value of the engine imbalance is determined based on the weight moment of the counterweight block with the set weight, the original vibration value, and the length of the first line segment after determining the third point.
[0013] Furthermore, determining the location of the engine imbalance based on the angle between the third reference line and the first reference line specifically involves:
[0014] Find the third position on the engine. The third position must satisfy the following condition: the angle between the first position and the third position relative to the engine rotation axis is equal to the angle between the third reference line and the first reference line.
[0015] The third position is the location of the engine imbalance.
[0016] Furthermore, the determination of the engine imbalance value based on the weight moment of the counterweight block with a set weight, the original vibration value, and the length of the first line segment after determining the third point is specifically as follows:
[0017] The product of the weight moment of the counterweight block with the set weight and the original vibration value, divided by the length of the first line segment after determining the third point, is the value of the engine imbalance.
[0018] Furthermore, the angle between the first position and the second position relative to the engine rotation axis is 90° to 120°.
[0019] Furthermore, the weight of the set weight counterweight is not equal to the weight of the original counterweight.
[0020] Furthermore, the weight of the set weight counterweight is less than the weight of the original counterweight.
[0021] Furthermore, the weight of the set weight counterweight is greater than the weight of the original counterweight.
[0022] Furthermore, the engine was tested on an engine test bench.
[0023] Furthermore, the counterweight is a balance weight pin.
[0024] A method for eliminating imbalance during engine testing includes:
[0025] The method for determining the unbalance during engine testing is used to determine the location and magnitude of the engine unbalance.
[0026] A counterweight is added at a position diagonally opposite the location of the engine imbalance. The moment of the added counterweight is equal to the value of the engine imbalance.
[0027] Compared with the prior art, the present invention has at least the following beneficial effects:
[0028] This invention provides a method for determining the imbalance during engine testing. The imbalance causing abnormal engine vibration is considered a vector determined by its magnitude and direction. The magnitude and direction of this imbalance vector can be determined by drawing a circle. Compared to the three-circle balancing test method, which requires four tests, this method only requires three tests to determine the magnitude and direction of the imbalance vector, thus determining the location and magnitude of the engine imbalance, and consequently, the weight and installation position of the counterweight. In other words, this invention simplifies the counterweight balancing test procedure by one step, saving testing costs, shortening the troubleshooting cycle, and effectively solving the problems of numerous tests, long production cycles, and high production costs.
[0029] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description
[0030] To more clearly illustrate the technical solutions in the specific embodiments of the present invention, the drawings used in the description of the specific embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.
[0031] Figure 1This is a flowchart illustrating a method for determining the imbalance during engine testing according to an embodiment of the present invention.
[0032] Figure 2 This is a reference test diagram for the vector method in an embodiment of the present invention;
[0033] Figure 3 This is a diagram of the first counterweight test run using the vector method according to an embodiment of the present invention;
[0034] Figure 4 This is a diagram of the second counterweight test run using the vector method according to an embodiment of the present invention;
[0035] Figure 5 This is the original imbalance direction diagram of an embodiment of the present invention. Detailed Implementation
[0036] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0037] like Figure 1 As shown in the figure, an embodiment of the present invention provides a method for determining the imbalance during engine testing, which specifically includes the following steps:
[0038] S1. Conduct the first test run of the engine to obtain the original vibration value of the engine, and draw the first circle 1 with the original vibration value as the radius.
[0039] It should be understood that after the engine is fully assembled, several original counterweights are already installed on it. For example, the engine has 24 counterweight mounting holes distributed along its circumference, with one original counterweight installed in each hole. In this embodiment, the original counterweights are Group I balance counterweight pins, and one Group I balance counterweight pin is installed in each counterweight mounting hole.
[0040] Specifically, step S1 involves completing a baseline test run (the first test run) according to the prescribed procedure to obtain the engine's original vibration value, combined with... Figure 2 As shown, the first circle 1 is drawn with the original vibration value as the radius.
[0041] During the first test run, the initial vibration caused by the engine's initial imbalance was considered as a vector (hereinafter referred to as the "initial imbalance vector"). The magnitude is known, representing the original vibration value (i.e., the radius of the first circle 1), while the direction is unknown. Therefore, it forms... Figure 2 The original unbalanced vector shown has a known size but unknown endpoints. Its endpoint can only move on the first circle 1.
[0042] S2. After replacing the original counterweight at the first position on the engine with a counterweight of a set weight, conduct a second test run to obtain the first counterweight vibration value of the engine. Draw a second circle 2 with the first counterweight vibration value as the radius. The second circle 2 is concentric with the first circle 1.
[0043] It should be noted that the first position can be the position corresponding to any original counterweight on the engine.
[0044] For step S2, for example, the group I counterweight pin in the first counterweight mounting hole of the engine is replaced with a group IV counterweight pin (whose weight moment M) Ⅳ (Given), the first counterweight balancing test (second test run) was completed according to the prescribed procedure, and the first counterweight vibration value of the engine was obtained. Combined with... Figure 3 As shown, a second circle 2 is drawn with the vibration value of the first counterweight as the radius.
[0045] According to the principle of vector addition, Form a closed vector triangle OMN, where:
[0046] The vibration vector generated by the installation of the group IV counterweight (hereinafter referred to as the "first counterweight vector") has an unknown magnitude but a known direction (parallel to the first reference line X).
[0047] This is the original unbalanced vector;
[0048] The vibration vector is generated by the superposition of the original unbalance vector and the first counterweight vector. Its magnitude is known, and it is the vibration value of the first counterweight (i.e., the radius of the second circle 2). Its direction is unknown.
[0049] S3. Replace the original counterweight at the first position on the engine with the original counterweight, and replace the original counterweight at the second position on the engine with the counterweight of the set weight. Then, conduct a third test run to obtain the second counterweight vibration value of the engine. Draw a third circle 3 with the second counterweight vibration value as the radius. The third circle 3 is concentric with the first circle 1.
[0050] It should be noted that the second position can be the position corresponding to other original counterweights on the engine that are different from the first position.
[0051] Preferably, the angle between the first position and the second position relative to the engine rotation axis is 90° to 120°.
[0052] For step S3, for example, after parking, the group IV counterweight pin in the first counterweight mounting hole is restored to a group I counterweight pin, and the group I counterweight pin in the ninth counterweight mounting hole of the engine is replaced with a group IV counterweight pin (whose weight moment M) Ⅳ Given that the angle between the first and second positions relative to the engine's rotation axis is 120°, the second counterweight balancing test (the third test) is completed according to the prescribed procedure, and the vibration value of the engine's second counterweight is obtained. Figure 4 As shown, a third circle 3 is drawn with the vibration value of the second counterweight as the radius.
[0053] It should be noted that after the third test run, after stopping the vehicle, the group IV counterweight pin in the 9th counterweight mounting hole should be restored to the group I counterweight pin.
[0054] Similarly, according to the principle of vector addition, Form a closed vector triangle OPQ, where:
[0055] The vibration vector generated by the installation of the group IV counterweight (hereinafter referred to as the "second counterweight vector") has an unknown magnitude but a known direction (parallel to the second reference line Y).
[0056] This is the original unbalanced vector;
[0057] The vibration vector is generated by the superposition of the original unbalance vector and the second counterweight vector. Its magnitude is known, and it is the vibration value of the second counterweight (i.e., the radius of the third circle 3). Its direction is unknown.
[0058] S4. Arbitrarily select a first point on the first circle 1 to represent the first position, and denote the line connecting the first point and the center of the circle as the first reference line X. Select a second point on the first circle 1 to represent the second position, and denote the line connecting the second point and the center of the circle as the second reference line Y. The selection of the second point must satisfy the following condition: the angle between the first reference line X and the second reference line Y is equal to the angle between the first position and the second position relative to the engine rotation axis.
[0059] S5. Draw a first line segment connecting the first circle 1 and the second circle 2, parallel to the first reference line X, and draw a second line segment connecting the first circle 1 and the third circle 3, parallel to the second reference line Y. When the first line segment and the second line segment are of equal length and intersect at a third point on the first circle 1, denote the line connecting the third point and the center of the circle as the third reference line, and measure the angle between the third reference line and the first reference line X.
[0060] Specifically, such as Figure 5 As shown, the vibration vector generated by the first installation of the group IV counterweight pins Parallel to the first reference line X, forming Figure 5 The vector triangle shown is OMN or OM'N'. Based on the original unbalanced vector... The uniqueness of vector triangle OMN and OPQ means that the sides OM and OP must coincide, that is, the position of point M or point P on the first circle 1 is fixed, and and All of these are vibration vectors generated by the group IV balancing counterweights, therefore
[0061] The original unbalance vector was determined using the above graphical method. Direction and counterweight vector and The size (i.e., length), and then based on and The weight moment M of the counterweight pin in Group IV Ⅳ The correspondence can determine the original unbalance vector. The corresponding weight moment M0.
[0062] S6. Determine the location of the engine imbalance based on the angle between the third reference line and the first reference line X, as follows:
[0063] Find the third position on the engine. The third position must satisfy the following condition: the angle between the first position and the third position relative to the engine rotation axis is equal to the angle between the third reference line and the first reference line X.
[0064] The third location found is the location of the engine imbalance.
[0065] Based on the weight moment of the counterweight with a set weight, the original vibration value, and the length of the first line segment after determining the third point, the value of the engine imbalance is determined, specifically as follows:
[0066] The value of engine imbalance is obtained by multiplying the weight moment of the counterweight block with the original vibration value and then dividing by the length of the first line segment after determining the third point.
[0067] In one embodiment, the weight of the set weight counterweight is greater than the weight of the original counterweight, or the weight of the set weight counterweight is less than the weight of the original counterweight.
[0068] This invention also provides a method for eliminating engine imbalance during overall test runs. After three test runs, the magnitude and direction of the original engine imbalance are clearly defined. Therefore, a counterweight can be added diagonally to offset the original imbalance. Specifically, the method described in the above embodiment for determining engine imbalance during overall test runs is used to determine the location and magnitude of the engine imbalance. After determining the location and magnitude of the engine imbalance, a counterweight is added diagonally to the location of the engine imbalance. The moment of the added counterweight is equal to the value of the engine imbalance. This invention also solves the vibration problem by working on the test bench, that is, without disassembling the engine, the imbalance can be reduced on the test bench, thereby reducing overall engine vibration and eliminating abnormal engine vibration.
[0069] In the description of this invention, it should be understood that the terms "upper", "lower", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.
[0070] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.
[0071] In this invention, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.
[0072] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.
[0073] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.
[0074] Finally, it should be noted that the above-described embodiments are merely specific implementations of the present invention, used to illustrate the technical solutions of the present invention, and not to limit it. The scope of protection of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments within the technical scope disclosed in the present invention, or make equivalent substitutions for some of the technical features; and these modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.
Claims
1. A method of determining an unbalance amount of an engine as a whole during a running-in test, characterized by, include: The engine was tested for the first time to obtain the original vibration value. The first circle was drawn with the original vibration value as the radius. After replacing the original counterweight at the first position on the engine with a counterweight of a set weight, a second test was conducted to obtain the first counterweight vibration value of the engine. A second circle was drawn with the first counterweight vibration value as the radius, and the second circle was concentric with the first circle. After replacing the original counterweight at the first position on the engine with the original counterweight, and replacing the original counterweight at the second position on the engine with the counterweight of the set weight, a third test was conducted to obtain the second counterweight vibration value of the engine. A third circle was drawn with the second counterweight vibration value as the radius, and the third circle was concentric with the first circle. Arbitrarily select a first point on the first circle to represent the first position, and denote the line connecting the first point and the center of the circle as the first reference line. Select a second point on the first circle to represent the second position, and denote the line connecting the second point and the center of the circle as the second reference line. The selection of the second point must satisfy the following condition: the angle between the first reference line and the second reference line is equal to the angle between the first position and the second position relative to the engine rotation axis. Draw a first line segment that connects the first circle and the second circle and is parallel to the first reference line, and draw a second line segment that connects the first circle and the third circle and is parallel to the second reference line. When the first line segment and the second line segment are of equal length and intersect at a third point on the first circle, record the line connecting the third point and the center of the circle as the third reference line, and measure the angle between the third reference line and the first reference line. The location of the engine imbalance is determined based on the angle between the third reference line and the first reference line. The value of the engine imbalance is determined based on the weight moment of the counterweight block with the set weight, the original vibration value, and the length of the first line segment after determining the third point.
2. The method of claim 1, wherein, The determination of the engine imbalance location based on the angle between the third reference line and the first reference line is as follows: Find the third position on the engine. The third position must satisfy the following condition: the angle between the first position and the third position relative to the engine rotation axis is equal to the angle between the third reference line and the first reference line. The third position is the location of the engine imbalance.
3. The method of claim 1, wherein the method further comprises: The determination of the engine imbalance value based on the weight moment of the counterweight block with a set weight, the original vibration value, and the length of the first line segment after determining the third point is as follows: The product of the weight moment of the counterweight block with the set weight and the original vibration value, divided by the length of the first line segment after determining the third point, is the value of the engine imbalance.
4. The method of claim 1, wherein, The angle between the first position and the second position relative to the engine rotation axis is 90° to 120°.
5. The method of claim 1, wherein, The weight of the counterweight with the set weight is not equal to the weight of the original counterweight.
6. The method for determining the imbalance during engine testing according to claim 5, characterized in that, The weight of the counterweight with the set weight is less than the weight of the original counterweight.
7. The method for determining the imbalance during engine testing according to claim 5, characterized in that, The weight of the set weight counterweight is greater than the weight of the original weight counterweight.
8. The method for determining the imbalance during engine testing according to claim 1, characterized in that, The engine is tested on the engine test bench.
9. The method for determining the imbalance during engine testing according to claim 1, characterized in that, The counterweight is a counterweight nail.
10. A method for eliminating imbalance during engine testing, characterized in that, include: The method for determining the unbalance during engine testing as described in any one of claims 1 to 9 is used to determine the location and magnitude of the engine unbalance. A counterweight is added at a position diagonally opposite the location of the engine imbalance. The moment of the added counterweight is equal to the value of the engine imbalance.