Axial force sensor and engine test run device

Abstract

The invention relates to an axial force sensor and an engine test run device, which are used for solving the problem of inaccurate thrust measurement caused by lateral force brought by device deformation at present. The device comprises a mounting unit, a force transmission steel ball, a force sensing unit, a first base, a second base and at least two bolt assemblies for connecting the first base and the second base, the bolt assembly comprises a bolt and a limiting nut; a bolt through hole is formed in the first base; the tail of the bolt sequentially penetrates through the bolt through hole and the limiting nut and then is fixedly connected with the second base. The limiting device is arranged on the lower surface of the first base, the lower end face of the limiting device is provided with a groove with a semicircular section, and the radius of the section of the groove is larger than that of the force transmission steel ball. The force sensing unit is arranged on the upper surface of the second base; the axial force conduction steel ball is located between the limiting device and the force sensing unit, and the axial force conduction steel ball is in point contact with the groove and the force sensing unit; the upper surface of the first base is used for connecting a to-be-tested piece.

Description

Technical Field

[0001] The invention relates to a thrust measurement device for eliminating the influence of lateral force, and in particular to an axial force sensor and an engine test device. Background Art

[0002] Thrust testing is required during the engine development phase to verify the engine's design performance. During the thrust test, it is necessary to obtain the thrust values ​​under various operating conditions.

[0003] When the engine is operating at high power, the engine support frame deforms outward, which will introduce a lateral force component into the thrust actually measured by the sensor. As a result, the force value measured by the axial force sensor not only includes the thrust of the engine under test, but also has an obvious lateral force influence, causing the thrust finally measured by the sensor to deviate significantly from the actual thrust. Especially in a non-vertically installed test bench, the engine's own weight will also aggravate the influence of the lateral force, resulting in inaccurate measurement results.

[0004] Therefore, there is currently a lack of a device that can avoid the influence of the lateral force caused by deformation on the thrust. Summary of the invention

[0005] The present invention provides an axial force sensor and an engine test device, which are used to solve the problem of inaccurate axial thrust measurement caused by lateral force caused by device deformation.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows:

[0007] An axial force sensor, which is special in that it includes a mounting unit, a limit device, a force conducting steel ball, and a force sensing unit;

[0008] The mounting unit comprises a first base, a second base and at least two bolt assemblies connecting the first base and the second base; the bolt assemblies comprise bolts and limiting nuts;

[0009] The first base is provided with bolt through holes having the same number as the bolts, and the bolt through holes are rectangular holes, waist-shaped holes or diamond-shaped holes; the tail of the bolt passes through the bolt through hole and the limit nut in sequence and is fixedly connected to the second base;

[0010] The limiting device is arranged on the lower surface of the first base, and a groove with a semicircular cross section is arranged on the lower end surface thereof, the extension direction of the groove is consistent with the extension direction of the bolt through hole, and the cross-sectional radius of the groove is greater than the radius of the force conducting steel ball;

[0011] The force sensing unit is arranged on the upper surface of the second base;

[0012] The axial force conducting steel ball is located between the limit device and the force sensing unit, and the axial force conducting steel ball is in contact with the groove and the sensitive surface of the force sensing unit respectively;

[0013] The upper surface of the first base is used to connect the device to be tested;

[0014] When the force sensing unit outputs a maximum value, the distance between the limit nut and the first base is 0;

[0015] The first base can move relatively along the axial direction of the bolt.

[0016] Furthermore, a fixing threaded hole is provided on the upper surface of the second base, and the force sensing unit is connected to the upper surface of the second base through the fixing threaded hole.

[0017] Furthermore, the mounting unit also includes a locking nut; the locking nut is used to lock and fix the tail of the bolt on the second base.

[0018] An engine test device, comprising a test bench, which is special in that: it also comprises N axial force sensors as above, wherein N≥3;

[0019] The N axial force sensors are located between the test bench and the unit under test and are evenly distributed around the circumference;

[0020] The grooves of the limiting devices of the N axial force sensors are arranged along the radial direction of the circumference;

[0021] When the distance between the limit nut and the first base is the largest, the force sensing unit displays 0;

[0022] The first bases of the N axial force sensors are sequentially connected to form a circular simulation test bench connecting frame;

[0023] The second bases of the N axial force sensors are sequentially connected to form a circular simulation test unit connection frame;

[0024] The simulation test bench connection frame is fixedly connected to the unit under test; the simulation test unit connection frame is fixedly connected to the test bench.

[0025] Further, the upper surface of the first base in the axial force transmission unit is provided with a first threaded hole, and the lower surface of the second base is provided with a second threaded hole;

[0026] The unit under test is connected to the simulation test bench connecting frame via a first threaded hole on the simulation test bench connecting frame, and the test bench is connected to the simulation test unit connecting frame via a second threaded hole on the simulation test unit connecting frame.

[0027] Furthermore, both the first threaded hole and the second threaded hole are blind holes.

[0028] Furthermore, N=8.

[0029] Furthermore, the diameter of the bolt is 0.5-3 mm smaller than the length of the bolt through hole in the extending direction; and there is a gap of 1-3 mm between the limiting nut and the lower surface of the first base.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] 1. In the present invention, by providing a bolt through hole, and the radial dimension of the bolt through hole is larger than the diameter of the bolt screw, the screw can be slightly deformed in the radial direction after being subjected to force, and the force-conducting steel ball can be slightly moved, so as to ensure that the lateral force caused by the outward deformation of the engine support frame under high power state is eliminated.

[0032] 2. In the present invention, a force-conducting steel ball is provided so that only the top of the force-conducting steel ball contacts the limit device, thereby ensuring that the force-conducting steel ball and the force sensing unit are only subjected to axial force, so that the force value finally measured is accurate.

[0033] 3. In the present invention, a radial groove is provided on the lower end surface of the limit device, and the radius of the groove is larger than the force-conducting steel ball, so as to ensure that the force-conducting steel ball is in point contact with the groove and that the force-conducting steel ball remains stable when moving, thereby ensuring the safety of the entire measuring process.

[0034] 4. In the present invention, there is a gap between the limiting nut on the screw rod and the lower surface of the first base, which provides space for the first base and the bolt to deform, making the device safer to install during engine thrust testing.

[0035] Furthermore, the gap between the limit nut at the upper end of the screw and the lower surface of the first base in the present invention is calibrated by a standard dynamometer before testing to ensure that the upper and lower limit measurement gaps of the sensor range are within the safe operating range of the sensor, thereby ensuring the safety of the sensor.

[0036] 5. The present invention eliminates the influence of lateral force as a whole. Compared with the existing multi-component force sensor measurement in which the influence of lateral force is controlled within 1% by fitting, it has more advantages in ensuring measurement accuracy.

[0037] 6. The engine test device of the present invention specifically uses eight sensors evenly distributed so that there is a sensor every 45°, which is convenient for calculating the axial force in each angular direction and drawing the axial force curve in each angular direction. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a structural schematic diagram of an embodiment of an axial force sensor of the present invention;

[0039] Figure 2 This is a schematic structural diagram of a first base in an embodiment of the present invention;

[0040] Figure 3 is a schematic structural diagram of a second base in an embodiment of the present invention;

[0041] Figure 4 It is a schematic diagram of the connection of multiple axial force sensors in an embodiment of the engine test device of the present invention;

[0042] Figure 5 The figure is a schematic diagram of the installation of multiple axial force sensors, the tested unit and the test bench in an embodiment of the present invention.

[0043] The specific reference numerals are as follows:

[0044] 1. Bolt through hole; 2. First threaded hole; 3. Bolt; 4. First base; 5. Limit nut; 6. Force conduction steel ball; 7. Force sensing unit; 8. Second base; 9. Second threaded hole; 10. Fixed threaded hole; 11. Limit device; 12. Test bench; 13. Axial force sensor; 14. Test unit; 15. Locking nut; 16. Simulation test bench connecting frame; 17. Simulation test unit connecting frame. DETAILED DESCRIPTION

[0045] The present invention will be further described below in conjunction with the accompanying drawings and specific implementation methods.

[0046] The present invention provides an axial force sensor, such as Figure 1 As shown, it includes a limit device 11, a force-conducting steel ball 6 and a force sensing unit 7. The limit device 11 and the force sensing unit 7 are correspondingly arranged, and the force-conducting steel ball 6 is located between the limit device 11 and the force sensing unit 7, so that the force-conducting steel ball 6 contacts the lower end of the limit device 11 and the input end of the force sensing unit 7 respectively.

[0047] The lower end surface of the limit device 11 is provided with a groove with an arc or semicircular cross section, so that the force-conducting steel ball 6 is located in the groove and can only move along the extending direction of the groove. The width dimension or cross-sectional radius of the groove is larger than the diameter of the force-conducting steel ball 6, so that only the vertex of the conductive steel ball 6 contacts the force sensing unit 7, so that the force can only be transmitted through the vertex of the axial conductive steel ball 6. Therefore, only the axial force can be measured in the force sensing unit 7.

[0048] Axial force sensors also include Figure 1 , Figure 2 and Figure 3 The first base 4 , the second base 8 and the bolt 3 are shown. The upper end surface of the limiting device 11 is connected to the lower surface of the first base 4 , and the force sensing unit 7 is connected to the upper surface of the second base 8 through the fixing threaded hole 10 .

[0049] The tail of the bolt 3 passes through the bolt through hole 1 set on the first base 4, so that the head of the bolt 3 contacts the upper surface of the first base 4. The bolt through hole 1 can be a rectangular hole, a waist-shaped hole, or a diamond-shaped hole; and the screw diameter of the bolt 3 is 0.5 to 3 mm smaller than the length of the bolt through hole 1 in the longitudinal direction, ensuring that there is enough space for buffering when deformation occurs in the lateral expansion direction; after the tail of the bolt 3 passes through the bolt through hole 1, it is finally fixed on the second base 8.

[0050] Each bolt 3 is provided with a limiting nut 5 and a locking nut 15. The limiting nut 5 is located at the upper end of the screw rod of the bolt 3 and there is a gap of 1-3 mm between it and the lower surface of the first base 4, and the gap is used for buffering; the locking nut 15 is located at the lower end of the screw rod of the bolt 3 and contacts with the upper surface of the second base 8, and is used to lock and fix the tail of the bolt 3 on the second base 8.

[0051] The force buffered by the distance between the lower surface of the first base 4 and the limiting nut 5 is less than or equal to the maximum range of the force sensing unit 7, thereby ensuring the safety of the use of the force sensing unit 7 and preventing inaccurate measurement by the force sensing unit 7.

[0052] The upper surface of the first base 4 is provided with a blind-hole-shaped first threaded hole 2 for connecting with the tested unit 14 . The lower surface of the second base 8 is provided with a blind-hole-shaped second threaded hole 9 for connecting with the test bench 12 .

[0053] An engine test device, such as Figure 4 As shown, it includes eight axial force sensors 13, a tested unit 14 and a test bench 12; the first bases 4 of the eight axial force sensors 13 are connected in sequence to form a simulated test bench connecting frame 16, so the upper surface of the simulated test bench connecting frame 16 has eight first threaded holes 2; the second bases 8 of the eight axial force transmission units are connected in sequence to form a simulated test unit connecting frame 17, so the lower surface of the simulated test unit connecting frame 17 has eight second threaded holes 9.

[0054] The simulation test bench connecting frame 16 is connected to the test bench 12 through eight first threaded holes 2, and the simulation test unit connecting frame 17 is connected to the tested unit 14 through eight second threaded holes 9, forming an engine test device. Figure 5 As shown, the engine test device can ensure that only the axial force is measured. When the engine is installed on the test bench, the thrust of the engine is equal to the axial combined force of the eight axial force sensing units 7.

[0055] The number of the axial force sensors 13 can be specifically selected according to actual conditions, but usually at least three are selected, typically six or eight.

Claims

1. An axial force sensor, characterized in that: It comprises a mounting unit, a limiting device (11), a force conducting steel ball (6), and a force sensing unit (7); The installation unit comprises a first base (4), a second base (8) and at least two bolt assemblies connecting the first base (4) and the second base (8); the bolt assembly comprises a bolt (3) and a limiting nut (5); The first base (4) is provided with bolt through holes (1) whose number is the same as the number of the bolts (3), and the bolt through holes (1) are rectangular holes, waist-shaped holes or diamond-shaped holes; the tail of the bolt (3) passes through the bolt through hole (1) and the limit nut (5) in sequence and is then fixedly connected to the second base (8); The limiting device (11) is arranged on the lower surface of the first base (4), and a groove with a semicircular cross section is arranged on the lower end surface thereof, the extension direction of the groove is consistent with the extension direction of the bolt through hole (1), and the cross-sectional radius of the groove is greater than the radius of the force conducting steel ball (6); The force sensing unit (7) is arranged on the upper surface of the second base (8); The axial force conducting steel ball (6) is located between the limiting device (11) and the force sensing unit (7), and the axial force conducting steel ball (6) is in contact with the groove and the sensitive surface of the force sensing unit (7) respectively; The upper surface of the first base (4) is used for connecting the object to be tested; When the force sensing unit (7) outputs a maximum value, the distance between the limit nut (5) and the first base (4) is 0; The first base (4) can move relatively along the axial direction of the bolt (3).

2. An axial force sensor according to claim 1, characterized in that: A fixing threaded hole (10) is provided on the upper surface of the second base (8), and the force sensing unit (7) is connected to the upper surface of the second base (8) via the fixing threaded hole (10).

3. An axial force sensor according to claim 1 or 2, characterized in that: The mounting unit further comprises a locking nut (15); the locking nut (15) is used to lock and fix the tail of the bolt (3) on the second base (8).

4. An engine test device, comprising a test bench (12), characterized in that: It also includes N axial force sensors (13) according to any one of claims 1 to 3, wherein N ≥ 3; The N axial force sensors (13) are located between the test bench (12) and the tested unit (14) and are evenly distributed around the circumference; The grooves of the limiting devices (11) of the N axial force sensors (13) are arranged along the radial direction of the circumference; When the distance between the limiting nut (5) and the first base (4) is the largest, the force sensing unit (7) displays 0; The first bases (4) of the N axial force sensors (13) are sequentially connected to form a circular simulation test bench connecting frame (16); The second bases (8) of the N axial force sensors (13) are sequentially connected to form a circular simulation test unit connecting frame (17); The simulation test bench connection frame (16) is fixedly connected to the tested unit (14); and the simulation test unit connection frame (17) is fixedly connected to the test bench (12).

5. An engine testing device according to claim 4, characterized in that: The upper surface of the first base (4) in the axial force transmission unit is provided with a first threaded hole (2), and the lower surface of the second base (8) is provided with a second threaded hole (9); The unit under test (14) is connected to the simulation test bench connecting frame (16) via a first threaded hole (2) on the simulation test bench connecting frame (16), and the test bench (12) is connected to the simulation test unit connecting frame (17) via a second threaded hole (9) on the simulation test unit connecting frame (17).

6. An engine testing device according to claim 5, characterized in that: The first threaded hole (2) and the second threaded hole (9) are both blind holes.

7. An engine testing device according to claim 5 or 6, characterized in that: Said N=8.

8. An engine testing device according to claim 5 or 6, characterized in that: The diameter of the bolt (3) is 0.5 to 3 mm smaller than the length of the bolt through hole (1) in the extension direction; and there is a gap of 1 to 3 mm between the limiting nut (5) and the lower surface of the first base (4).

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