A starting friction force detection device and detection method for a rubber rolling diaphragm

Abstract

The present invention belongs to the field of aircraft engine fuel regulator accessory detection, and particularly relates to a starting friction force detection device and detection method for a rubber rolling diaphragm. The size of the diaphragm friction force cannot be determined before installation, which seriously affects the performance of fuel regulation of a certain type of aircraft engine. The measuring mechanism of the present invention includes a tension gauge that can move up and down, and a hook is provided at the lower end of the tension gauge; the upper bracket of the fixing mechanism is a bowl-shaped structure or a U-shaped axially symmetrical structure in cross section, and the bottom of the upper bracket and the lower bracket are relatively connected to clamp the rubber rolling diaphragm therein; the annular pressure plate of the upper end cover is pressed on the upper end surface of the base, and the cylindrical structure is sleeved on the outside of the upper bracket, and the annular pressure plate has a lower annular groove for accommodating a raised sealing structure, and a straight groove on the upper end surface; the cavity between the upper bracket and the cylindrical structure accommodates the fitted inner and outer annular surfaces, and the upper bracket and the lower bracket are driven to move up and down by the hook. The structural design is simple and easy to operate.

Description

Technical Field

[0001] The invention belongs to the field of aircraft engine fuel regulator accessory detection, and particularly relates to a starting friction force detection device and a detection method for a rubber rolling diaphragm. Background Art

[0002] A rubber rolling diaphragm is required in the fuel regulation system of a certain type of aircraft engine. During the system startup process, the diaphragm itself will roll and generate friction. The magnitude of the friction determines the sensitivity of the system startup. Sometimes the system startup is not sensitive due to the large friction of the diaphragm, and the magnitude of the diaphragm friction cannot be determined before installation. This problem has seriously affected the performance of the fuel regulation of a certain type of aircraft engine.

[0003] How to accurately measure the friction force of the diaphragm before installation and use it as the acceptance index of the diaphragm to ensure that the system can start smoothly under the specified pressure conditions after the diaphragm is installed has become a difficult problem. Summary of the invention

[0004] The purpose of the present invention is: the present invention designs a starting friction force detection device and detection method for a rubber rolling diaphragm, which can detect the friction force of the diaphragm by putting the rubber rolling diaphragm in a state when the system is started.

[0005] The technical solution of the present invention is: a starting friction force detection device for a rubber rolling diaphragm, the rubber rolling diaphragm has a convex sealing structure on the circumferential outer edge, and has a fitted inner ring surface and outer ring surface after installation, the detection device has a measuring mechanism and a fixing mechanism on the bottom plate, wherein

[0006] The measuring mechanism comprises a tension gauge which can move up and down, and a draw hook is provided at the lower end of the tension gauge;

[0007] The fixing mechanism includes a base, a lower bracket, an upper bracket, an upper end cover and a hook; wherein the base is placed on the bottom plate, and a groove for accommodating the lower bracket is provided on the upper end surface of the base, the upper bracket is a bowl-shaped structure or a U-shaped cross-section structure, and has a radially outward boss at the open end, and the upper bracket is relatively connected to the bottom of the lower bracket so as to clamp the rubber rolling diaphragm therein; the upper part of the upper end cover is a cylindrical structure, and the lower part is an annular pressure plate, which is pressed on the upper end surface of the base, the cylindrical structure is sleeved on the outside of the upper bracket, and the annular pressure plate has a lower annular groove for accommodating the raised sealing structure, and a straight groove on the upper end surface; the lower end of the hook is fixed on the base, and the upper end is buckled into the straight groove; the cavity between the upper bracket and the cylindrical structure accommodates the fitted inner and outer annular surfaces, and the upper bracket and the lower bracket are driven to move up and down by the pull hook.

[0008] Advantageously, the outer profile of the upper bracket matches the inner surface shape of the rubber rolling diaphragm, and the upper profile of the lower bracket matches the outer surface shape of the rubber rolling diaphragm.

[0009] Advantageously, the periphery of the base has an integrated hook fixing seat, and the lower end of the hook is fixedly connected to the hook fixing seat.

[0010] Advantageously, the lower bracket is a bowl-shaped or U-shaped cross-section axisymmetric structure, the upper bracket and the lower bracket are connected by a connecting rod and a fixing bolt, and the upper end of the connecting rod is connected to the hook.

[0011] Advantageously, the measuring mechanism further comprises a slider, a guide rod, a displacement nut, a displacement bolt, a cross beam and a handle. The guide rod is a pair, the lower end of which is fixed to the base plate, and the upper end is fixed to the cross beam. The displacement bolt passes through the cross beam, and the lower end is fixedly connected to the slider. The upper rod portion and the displacement nut form a screw structure, and the upper and lower positions of the slider are controlled by turning the handle. The slider is fixedly connected to the table support.

[0012] Advantageously, the sliding block is fixedly connected to the watch support via a first screw.

[0013] Advantageously, the guide rod is fixed to the crossbeam by means of a second screw.

[0014] Advantageously, the displacement bolt is provided with a nut on the rod portion at the lower side of the cross beam, and is limited by the nut.

[0015] The present invention also provides a method for detecting the starting friction force of a rubber rolling diaphragm, using the above-mentioned detection device, and the detection includes the following steps:

[0016] S1. Installation

[0017] First, coaxially clamp the rubber rolling diaphragm between the upper bracket and the lower bracket and connect them as a whole; place the lower bracket in the upper end groove of the base and cover it; buckle the upper end of the hook into the straight groove of the upper end cover; connect the hook of the tension gauge with the upper bracket;

[0018] S2. Testing

[0019] Operate the tension gauge to lift the upper bracket upwards to read the tension value and determine whether the friction force meets the use conditions.

[0020] The working principle of the detection of the present invention is: after the diaphragm is fixed by a fixing device, when the fixing device is pulled by a force measuring device, the diaphragm forms the same state as when the system is started, and the friction value of the diaphragm is read out by a tension meter.

[0021] The advantages of the present invention are: the rubber rolling diaphragm starting friction force detection device can simulate the diaphragm state when the system is started and measure its friction force, and the structure design is simple and easy to operate. The diaphragm friction force detection is completed before the diaphragm is installed, and the diaphragm to be used is selected for installation, so as to avoid the ineffective work caused by rework due to excessive diaphragm friction causing the system to fail to start. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 Illustration of the rubber rolling diaphragm after installation and before startup;

[0023] Figure 2 A schematic diagram of the structure of the detection device of the present invention;

[0024] Figure 3 The diaphragm fixing mechanism of the present invention is shown in the figure.

[0025] In the figure, 1-bottom plate, 2-draw hook, 3-table support, 4-tension gauge, 5-slider, 6-first screw, 7-guide rod, 8-handle, 9-displacement nut, 10-displacement bolt, 11-second screw, 12-crossbeam, 13-nut, 14-base, 15-hook fixing seat, 16-upper end cover, 17-upper bracket, 18-connecting rod, 19-lower bracket, 20-fixing bolt, 21-hook DETAILED DESCRIPTION

[0026] The present invention is further described in detail below in conjunction with the accompanying drawings:

[0027] A starting friction force detection device for rubber rolling diaphragm Figure 2-3 , used to detect rubber rolling diaphragms Figure 1 The friction force generated during startup includes a measuring mechanism and a fixing mechanism fixed on the base plate 1.

[0028] The measuring mechanism includes a base plate 1, a hook 2, a table support 3, a tension gauge 4, a slider 5, a guide rod 7, a handle 8, a displacement nut 9, a displacement bolt 10, a crossbeam 12 and a nut 13. The base plate 1 is interference fit with a pair of guide rods 7, and a crossbeam 12 is fixed to the upper end of the guide rods 7. The slider 5 is slidably mounted on the guide rods 7, and the two are clearance-matched. To ensure free sliding and accuracy, the clearance is within 0.02mm.

[0029] The bolt 10 passes through the cross beam 12, and the lower end of the bolt 10 is fixed to the slider 5 and fastened with a nut. The bolt 10 on the upper side of the cross beam 12 is connected to the displacement nut 9, and the displacement nut 9 is turned by the handle 8. The bolt adopts a fine pitch thread to ensure that it can move slowly and stably when used in conjunction with the displacement nut 9, and the displacement amount can be controlled by adjusting the nut 13.

[0030] The meter holder 3 is connected to the slider 5 at the side by a first screw 6, and is connected to the hook 2 at the bottom by a thread, and the hook 2 is connected to the connecting rod 18 to drive the rolling rubber diaphragm to move. A tension meter 4 is installed on the meter holder 3.

[0031] The fixing mechanism includes a base 14 , a hook fixing seat 15 , an upper end cover 16 , an upper bracket 17 , a connecting rod 18 , a lower bracket 19 , a fixing bolt 20 and a hook 21 .

[0032] There is a circular cavity in the center of the base 14, which is clearance-matched with the lower bracket 19, with a matching accuracy of 0.02mm, and the matching part adopts a circular ring contact to reduce the friction of the mechanism itself. A vent hole is designed in the center of the base 14 to ensure that when the fixed mechanism is used, there will be no air pressure resistance due to the high precision of the mechanism and good sealing. The function of the lower bracket 19 and the upper bracket 17 is to clamp the rolling diaphragm, and the size of the clamping part can be designed with reference to the size of the rolling diaphragm. At the same time, the upper bracket 17 and the lower bracket 19 are bowl-shaped or U-shaped cross-section axisymmetric structures, which can reduce the weight of the parts, and the outer surface of the upper bracket 17 matches the inner surface shape of the rubber rolling diaphragm, and the upper surface of the lower bracket 19 matches the outer surface shape of the rubber rolling diaphragm. The upper bracket 17 and the upper end cover 16 are clearance-matched, with a matching accuracy of 0.02mm, and the matching part adopts a circular ring contact. There is an annular sealing groove at the lower end of the upper end cover 16 for pressing the sealing end face of the rolling diaphragm. The upper bracket 17 and the lower bracket 19 are connected by the connecting rod 18 and the fixing bolt 20, and then placed in the base 14, and then the upper end cover 16 is installed, and the upper end cover 16 and the base 14 are fixed by the hook 21. Finally, the hook 2 of the measuring mechanism is connected to the connecting rod 18 of the fixing mechanism for measurement.

[0033] The rolling rubber diaphragm is installed between the base 14, the upper end cover 16, the upper bracket 17, and the lower bracket 19, wherein the inner and outer circle clearances of these parts are 0.02, and the luminosity of the joint parts reaches Ra0.4 to ensure position accuracy and smaller friction.

[0034] The hook 21 is used to fasten the hook fixing seat 15 and the upper end cover 17 in a quick-release manner.

[0035] When testing the friction force of the rubber rolling diaphragm, first install the diaphragm into the diaphragm fixing device. Figure 3 , install the rolling rubber diaphragm between the upper bracket 17 and the lower bracket 19 through the fixing bolt 20 and the connecting rod 18. Put the lower bracket 19 in the groove of the base 14, and insert the upper end of the hook into the straight groove of the upper end cover 16. The upper bracket 17 and the lower bracket 19 can slide freely in the base 14 and the upper end cover 16 as a whole. Then connect with the connecting rod 18 through the hook 2. Through the rotation of the displacement nut 9, the slider 5 is driven up and down through the lead screw, thereby driving the connecting rod 18 to move.

[0036] During this process, the diaphragm will form the same state as when the system is working, and generate friction itself. The friction at this time can be read through the tension meter 4 to determine whether it meets the use conditions. At the same time, the displacement of the slider can be adjusted by adjusting the nut 13 to try to be consistent with the diaphragm working to ensure the accuracy of the measurement.

Claims

1. A starting friction force detection device for a rubber rolling diaphragm, the rubber rolling diaphragm having a raised sealing structure on the circumferential outer edge, and having a fitted inner ring surface and an outer ring surface after installation, characterized in that: The detection device has a measuring mechanism and a fixing mechanism on a base plate (1), wherein The measuring mechanism comprises a tension gauge (4) which can move up and down, and a draw hook (2) is provided at the lower end of the tension gauge (4); The fixing mechanism comprises a base (14), a lower bracket (19), an upper bracket (17), an upper end cover (16) and a hook (21); wherein the base (14) is placed on the bottom plate (1), and a groove for accommodating the lower bracket (19) is provided on the upper end surface of the base (14); the upper bracket (17) is a bowl-shaped structure or a U-shaped axisymmetric structure in cross section, and has a radially outward boss at the open end; the upper bracket (17) is relatively connected to the bottom of the lower bracket (19) so as to clamp the rubber rolling diaphragm therein; the upper part of the upper end cover (16) is The cylindrical structure has an annular pressure plate at the bottom, which is pressed on the upper end surface of the base (14). The cylindrical structure is sleeved on the outside of the upper bracket (17), and the annular pressure plate has a lower annular groove for accommodating the raised sealing structure, and a straight groove on the upper end surface; the lower end of the hook (21) is fixed on the base (14), and the upper end is buckled into the straight groove; the cavity between the upper bracket (17) and the cylindrical structure accommodates the fitted inner and outer annular surfaces, and the upper bracket (17) and the lower bracket (19) are driven to move up and down through the pull hook (2).

2. The starting friction force detection device according to claim 1, characterized in that: The outer profile of the upper bracket (17) matches the inner surface shape of the rubber rolling diaphragm, and the upper profile of the lower bracket (19) matches the outer surface shape of the rubber rolling diaphragm.

3. The starting friction force detection device according to claim 1, characterized in that: The periphery of the base (14) has an integrated hook fixing seat (15), and the lower end of the hook (21) is fixedly connected to the hook fixing seat (15).

4. The starting friction force detection device according to claim 1, characterized in that: The lower bracket (19) is a bowl-shaped or U-shaped cross-section axisymmetric structure. The upper bracket (17) and the lower bracket (19) are connected via a connecting rod (18) and a fixing bolt (20). The upper end of the connecting rod (18) is connected to the draw hook (2).

5. The starting friction force detection device according to claim 1, characterized in that: The measuring mechanism further comprises a slider (5), a guide rod (7), a displacement nut (9), a displacement bolt (10), a crossbeam (12) and a handle (8). The guide rod (7) is a pair, the lower end of which is fixed on the base plate (1) and the upper end is fixed on the crossbeam (12). The displacement bolt (10) passes through the crossbeam (12) and the lower end is fixedly connected to the slider (5). The upper rod part and the displacement nut (9) form a screw structure, and the upper and lower positions of the slider (5) are controlled by rotating the handle (8). The slider (5) is fixedly connected to the table support (3).

6. The starting friction force detection device according to claim 5, characterized in that: The sliding block (5) is fixedly connected to the watch holder (3) via a first screw (6).

7. The starting friction force detection device according to claim 5, characterized in that: The guide rod (7) is fixed on the crossbeam (12) by means of a second screw (11).

8. The starting friction force detection device according to claim 5, characterized in that: The displacement bolt (10) is provided with a nut (13) on the rod portion at the lower side of the cross beam (12), and is limited in position by the nut (13).

9. A method for detecting the starting friction force of a rubber rolling diaphragm, using the detection device as described in any one of claims 1 to 8, characterized in that: The test involves the following steps: S1. Installation First, the rubber rolling diaphragm is coaxially clamped between the upper bracket (17) and the lower bracket (19) and connected as a whole; the lower bracket (19) is placed in the upper end groove of the base (14), and the upper end cover (16) is mounted; the upper end of the hook (21) is buckled into the straight groove of the upper end cover (16); the hook (2) of the tension gauge (4) is connected to the upper bracket (17); S2. Testing The tension gauge (4) is operated to lift the upper bracket (17) upwards, thereby reading the tension value and judging whether the friction force meets the use conditions.

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