A device and method for measuring the inner surface of an irregular engine

Abstract

The present invention discloses a device and method for measuring the surface of a special-shaped engine cavity, so as to solve the technical problem that the existing engine cavity detection device cannot perform long-stroke, high-efficiency and accurate measurement of the surface of a special-shaped engine cavity with a small space. Specifically, it includes a rotating optical fiber probe, a stepping trolley, a spiral core optical fiber and a signal control processing unit; the rotating optical fiber probe is installed on the stepping trolley, and is used to scan the inner wall of the cavity of the measured object; the stepping trolley is electrically connected to the signal control processing unit, and is used to drive the rotating optical fiber probe to move forward in the cavity of the measured object; one end of the spiral core optical fiber is connected to the rotating optical fiber probe, and the other end is connected to the signal control processing unit, and is used to transmit the optical signal detected by the rotating optical fiber probe to the control processing unit; the signal control processing unit is used to control the stepping trolley to move forward, control the rotating optical fiber probe to scan and detect, and is used to receive and process the optical signal detected by the rotating optical fiber probe.

Description

Technical Field

[0001] The invention relates to a device and a method for measuring the inner cavity surface of an engine, and in particular to a device and a method for measuring the inner cavity surface of a special-shaped engine. Background Art

[0002] With the rapid development of science and technology, the structure of industrial products is becoming more and more complex. At the same time, higher requirements are placed on the detection technology of complex structures. Among them, the engine is the power source of the rocket system, and the detection of the inner cavity surface and deformation during the engine manufacturing process and before and after use is particularly important.

[0003] The engine cavity surface detection method is divided into contact detection and non-contact detection according to whether the probe is in contact with the surface to be measured. Among the contact detection methods, the most representative is the stylus profilometer detection, which has high resolution and stable and reliable measurement results, but the measurement speed of this detection method is very slow and it is easy to scratch the surface to be measured; non-contact detection methods include time-of-flight method, structured light illumination method and interference method, etc. Although these methods can achieve non-destructive detection of the surface to be measured, they still cannot achieve large-stroke, high-efficiency and accurate detection for special-shaped engine cavities with small spaces. Summary of the invention

[0004] The purpose of the present invention is to provide a device and method for measuring the profile of an irregular engine inner cavity surface, so as to solve the technical problem that the existing engine inner cavity detection device cannot perform large-stroke, high-efficiency and accurate measurement of the profile of an irregular engine inner cavity surface with a smaller space.

[0005] In order to achieve the above-mentioned object, the present invention provides a device for measuring the inner cavity surface of a special-shaped engine, which is special in that it includes a rotating optical fiber probe, a stepping trolley, a spiral core optical fiber and a signal control processing unit;

[0006] The rotating optical fiber probe is mounted on the stepping carriage and is used to scan the inner wall of the cavity of the tested object;

[0007] The stepping carriage is electrically connected to the signal control processing unit and is used to drive the rotating optical fiber probe to move forward in the cavity of the test piece;

[0008] One end of the spiral core optical fiber is connected to the rotating optical fiber probe, and the other end is connected to the signal control processing unit, and is used to transmit the optical signal detected by the rotating optical fiber probe to the control processing unit;

[0009] The signal control processing unit is used to control the stepping carriage to move forward, control the rotating optical fiber probe to perform scanning detection, and receive and process the optical signal detected by the rotating optical fiber probe.

[0010] Further, the stepping trolley comprises a first mounting plate, a second mounting plate, N magnetic wheels and N driving units, N ≥ 3;

[0011] The magnetic wheel comprises a cylindrical wheel body; an oblique spiral pattern is provided on the outer surface of the wheel body;

[0012] The first mounting plate and the second mounting plate are respectively located at two ends of the N magnetic wheels; the N magnetic wheels are evenly distributed around the same central axis between the first mounting plate and the second mounting plate; the axles at both ends of the magnetic wheels are rotatably connected to the first mounting plate and the second mounting plate respectively;

[0013] The rotating optical fiber probe is fixed at the center of the first mounting plate and is coaxial with the central axis, with a detection end located outside the first mounting plate and the other end passing through the first mounting plate and connected to one end of the spiral core optical fiber passing through the second mounting plate;

[0014] The N driving units are installed between the first mounting plate and the second mounting plate and are located between the N magnetic wheels; the N driving units correspond one to one with the N magnetic wheels; the driving units are electrically connected to the signal control processing unit for driving the corresponding magnetic wheels to rotate.

[0015] Further, the driving unit includes a driving motor and a belt;

[0016] The drive motor is fixedly mounted between the first mounting plate and the second mounting plate and is located between the N magnetic wheels. The drive motor is electrically connected to the signal control processing unit. The rotating shaft of the drive motor and the axle of the magnetic wheel are parallel to each other. A driving pulley is provided on the rotating shaft of the drive motor, and a driven pulley is provided on the axle of the magnetic wheel. The belt is sleeved on the driving pulley and the driven pulley.

[0017] Further, said N=3;

[0018] The first mounting plate and the second mounting plate are both equilateral triangles;

[0019] The three magnetic wheels are rotatably connected to the three corners of the first mounting plate and the second mounting plate respectively.

[0020] Furthermore, a mounting tube and a triangular tube are provided between the first mounting plate and the second mounting plate;

[0021] The central axis of the mounting tube is parallel to the central axis of the magnetic wheel, one end of the mounting tube is fixedly connected to the first mounting plate, the other end of the mounting tube is fixedly connected to one end of the triangular tube, and the other end of the triangular tube is fixedly connected to the second mounting plate;

[0022] The other end of the rotating optical fiber probe passes through the first mounting plate and extends into the mounting tube;

[0023] One end of the spiral core optical fiber passes through the second mounting plate and the triangular tube in sequence and then extends into the mounting tube to be connected with the rotating optical fiber probe;

[0024] The three driving units are respectively fixedly mounted on three side surfaces of the triangular cylinder.

[0025] Furthermore, the wheel body includes a cylindrical magnetic core and a tire sleeved outside the magnetic core;

[0026] The tire is provided with the oblique spiral pattern on the outside.

[0027] Furthermore, a plurality of set screws are evenly distributed on the side wall of the mounting tube;

[0028] The set screw passes through the side wall of the installation tube to contact and position the spiral core optical fiber or the rotating optical fiber probe.

[0029] At the same time, the present invention also provides a method for measuring the inner cavity surface of a special-shaped engine, using the above-mentioned device for measuring the inner cavity surface of a special-shaped engine, which is special in that it includes the following steps:

[0030] Step 1: Place the stepper car in the cavity of the tested object;

[0031] Step 2: The stepping carriage is controlled to move in stages through the signal control processing unit, and in each stage, the rotating optical fiber probe is controlled to rotate one circle, so as to obtain the inner cavity surface data of the tested object in each stage;

[0032] Step 3: splice the surface data acquired at each stage to obtain the inner cavity surface of the measured object.

[0033] Beneficial effects of the present invention:

[0034] 1. The present invention integrates a rotating fiber optic probe on a stepper carriage, connects it to a signal control processing unit through a spiral core optical fiber, and electrically connects the stepper carriage to the signal control processing unit, so that the stepper carriage can be controlled by the signal control processing unit to perform phased displacement, and the rotating fiber optic probe can be used to scan and detect the surface data of the inner cavity of the measured object layer by layer, and finally the entire inner cavity surface of the measured object is obtained. The device only needs to place the stepper carriage and the rotating fiber optic probe together in the cavity of the measured object. On the one hand, it realizes the acquisition of surface data in a narrow space, and on the other hand, it can also realize the acquisition of surface data of the inner cavity of the measured object with a special shape, providing technical support for the measurement of the inner cavity surface of the special-shaped engine. In addition, the measuring device is controlled by a signal control processing unit located outside the cavity of the measured object, and the signal is transmitted through a spiral core optical fiber. The length of the spiral core optical fiber is determined according to the size of the collection stroke, thereby realizing the automation of surface data collection for a long stroke and improving the efficiency of surface measurement.

[0035] 2. The present invention uses a spiral core optical fiber to connect the signal control processing unit with the rotating optical fiber probe, so that the stepping carriage used to carry the rotating optical fiber probe can be displaced at will, thereby achieving the purpose of being able to measure the surface of an irregular inner cavity.

[0036] 3. The stepper carriage of the present invention uses magnetic wheels, which can make the stepper carriage adsorbed on the side wall of the inner cavity of the measured object in real time. On the one hand, it can make the displacement of the stepper carriage more accurate and stable without wheel running. On the other hand, it can also ensure the stable scanning and detection of the rotating optical fiber probe, thereby more accurately obtaining the inner cavity surface data of the measured object.

[0037] 4. The present invention adopts three magnetic wheels, which are distributed in an equilateral triangle. This can avoid the situation where the stepping carriage cannot move forward due to flipping in the special-shaped cavity during the measurement process, and further improve the stability of data acquisition.

[0038] 5. The wheel body of the present invention adopts a structure in which a tire is enclosed on the outside of a magnetic core. This makes the wheel magnetic on the one hand, and on the other hand, the tire can avoid scratching the inner cavity of the tested part. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a structural schematic diagram of an embodiment of a device for measuring the inner cavity surface of a special-shaped engine according to the present invention;

[0040] Figure 2 Schematic diagram of the three-dimensional structure of the stepping car in the embodiment of the present invention;

[0041] Figure 3 is a side view of the stepping trolley in an embodiment of the present invention;

[0042] Figure 4is a schematic structural diagram of a rotating optical fiber probe in an embodiment of the present invention;

[0043] Figure 5 1 is a measurement principle diagram of a rotating optical fiber probe in an embodiment of the present invention.

[0044] Figure Number:

[0045] 1-rotating fiber optic probe, 2-stepping trolley, 21-first mounting plate, 22-second mounting plate, 23-magnetic wheel, 24-driving unit, 241-driving motor, 242-belt, 25-mounting cylinder, 251-setting screw, 26-triangular cylinder, 3-helical core optical fiber, 4-signal control processing unit, 5-measured object; 6-rotating motor, 7-reflector, 8-fiber optic collimator, 9-measured surface. DETAILED DESCRIPTION

[0046] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0047] like Figure 1 As shown, a device for measuring the inner cavity surface of a special-shaped engine provided by an embodiment of the present invention includes a rotating optical fiber probe 1, a stepping trolley 2, a helical core optical fiber 3 and a signal control processing unit 4;

[0048] The rotating optical fiber probe 1 is mounted on the stepping carriage 2 and is used to scan the inner wall of the cavity of the object to be tested 5; the object to be tested 5 can be a normal-shaped engine cavity or a special-shaped engine cavity;

[0049] Combination Figures 2 to 4As shown, the stepping carriage 2 is electrically connected to the signal control processing unit 4, and is used to drive the rotating optical fiber probe 1 to move forward in the cavity of the test piece 5; specifically, the stepping carriage 2 includes a first mounting plate 21, a second mounting plate 22, N magnetic wheels 23 and N driving units 24, N ≥ 3; preferably N = 3 in the embodiment of the present invention, and the first mounting plate 21 and the second mounting plate 22 are arranged in an equilateral triangle; the first mounting plate 21 and the second mounting plate 22 are parallel to each other; three magnetic wheels 23 are arranged on the first mounting plate 21 and the second mounting plate 22 , and correspond to the three corners of the first mounting plate 21 and the second mounting plate 22 respectively, so that the three magnetic wheels 23 are distributed around the same central axis; each magnetic wheel 23 includes a cylindrical wheel body; the wheel body includes a cylindrical magnetic core and a tire mounted outside the magnetic core, the magnetic core can make the wheel magnetic, the tire can prevent the wheel from scratching the measured surface, and the tire can be made of rubber material; axles are respectively provided at the centers of the two ends of the wheel body, and the two axles are rotatably connected to a corner of the first mounting plate 21 and the second mounting plate 22 respectively. Oblique spiral patterns are provided on the outer surface of the wheel body; in this way, when the two magnetic wheels 23 in contact with the inner wall of the measured object 5 rotate in opposite directions, the entire stepping trolley 2 can move forward and backward, and when the two magnetic wheels 23 in contact with the inner wall of the measured object 5 rotate in the same direction, the entire stepping trolley 2 can move left and right.

[0050] A mounting tube 25 and a triangular tube 26 are also provided between the first mounting plate 21 and the second mounting plate 22; the mounting tube 25 and the triangular tube 26 are also provided between the three magnetic wheels 23; the central axis of the mounting tube 25 is parallel to the central axis of the magnetic wheel 23, one end of the mounting tube 25 is fixedly connected to the first mounting plate 21, the other end of the mounting tube 25 is fixedly connected to one end of the triangular tube 26, and the other end of the triangular tube 26 is fixedly connected to the second mounting plate 22; the rotating optical fiber probe 1 is fixed at the center of the first mounting plate 21, its detection end is located outside the first mounting plate 21, and the other end passes through the first mounting plate 21 and extends into the mounting tube 25; one end of the spiral core optical fiber 3 passes through the second mounting plate 22 and the triangular tube 26 in turn and then extends into the mounting tube 25 to be connected with the rotating optical fiber probe 1, and the other end is connected to the signal control processing unit 4; a plurality of set screws 251 are evenly distributed on the side wall of the mounting tube 25; the set screws 251 contact and position the spiral core optical fiber 3 or the rotating optical fiber probe 1 after passing through the side wall of the mounting tube 25. The driving unit 24 includes a driving motor 241 and a belt 242; the driving motor 241 is fixedly mounted between the first mounting plate 21 and the second mounting plate 22, and is located between the three magnetic wheels 23. Specifically, the three driving motors 241 are respectively mounted on the three surfaces of the triangular cylinder 26, and correspond to the three magnetic wheels 23 one by one. The driving motor 241 is electrically connected to the signal control processing unit 4; the rotating shaft of the driving motor 241 and the axle of the magnetic wheel 23 are parallel to each other. The rotating shaft of the driving motor 241 is provided with a driving pulley, and the axle of the magnetic wheel 23 is provided with a driven pulley. The belt 242 is mounted on the driving pulley and the driven pulley, so that the power can be transmitted through the belt, so that the driving motor 241 drives the corresponding magnetic wheel 23 to rotate. Of course, gears can also be used for transmission. In order to reduce the overall structure of the stepping trolley, this embodiment preferably uses a belt transmission method.

[0051] The signal control processing unit 4 is used to control the stepping trolley 2 to move forward, control the rotating optical fiber probe 1 to perform scanning detection, and also to receive and process the electrical signal detected by the rotating optical fiber probe 1. The rotating optical fiber probe 1 can also record the displacement path of the stepping trolley 2. With the help of the signal control processing unit 4, after the scanning detection of the entire engine inner cavity surface data is finally completed, the stepping trolley 2 can be safely evacuated according to the original displacement path.

[0052] It is worth noting that the measurement principle of the rotating optical fiber probe 1 is as follows:

[0053] like Figure 5As shown, the rotating fiber optic probe 1 includes a rotating motor 6, a reflector 7 and a fiber collimator 8; the laser is transmitted from the spiral core fiber 3 to the fiber collimator 8, and the fiber collimator 8 modulates the laser to reach the reflector 7, and the reflector 7 deflects the laser by 90° to the measured surface 9, and then returns to the original path carrying the detection information of the measured surface. Among them, the spiral core fiber 3 can realize small-angle and long-distance information transmission, which provides the possibility for the measurement of large-size, small-angle and special-shaped measured parts; the rotating motor 6 can drive the reflector 7 to rotate 360°, so that the rotating fiber optic probe 1 can perform all-round scanning and detection of the special-shaped engine cavity.

[0054] The steps of using the above-mentioned special-shaped engine inner cavity surface measurement device are as follows:

[0055] Step 1, placing the stepping carriage 2 in the cavity of the test piece 5;

[0056] Specifically, the stepping carriage 2 and the rotating optical fiber probe 1 carried by the stepping carriage 2 are placed together in the cavity of the measured object 5 .

[0057] Step 2: Control the stepping carriage 2 to move in stages through the signal control processing unit 4, and control the rotating optical fiber probe 1 to rotate one circle in each stage, so as to obtain the inner cavity surface data of the test piece 5 in each stage;

[0058] Specifically, the signal control processing unit 4 controls the driving motor 241 to start, so as to drive the magnetic wheel 23 to rotate in stages. The magnetic wheel 23 uses its own oblique spiral pattern to perform staged displacement in the cavity of the test piece. In each stage, the signal control processing unit 4 controls the rotating optical fiber probe 1 to rotate one circle, so as to obtain the inner cavity surface data of the test piece 5 in each stage; at the same time, the rotating optical fiber probe 1 can also record the displacement path of the stepping trolley 2.

[0059] Step 3: splice the surface data acquired at each stage to obtain the inner cavity surface of the measured object 5.

[0060] Specifically, the acquired inner cavity surface data of the test piece 5 at each stage is transmitted to the signal control processing unit 4 through the spiral core optical fiber 3 for information splicing processing to obtain the entire inner cavity surface of the test piece 5, and finally complete the detection of the inner cavity surface data of the entire special-shaped engine.

[0061] Finally, the signal control processing unit 4 can also be used to control the stepping trolley 2 to safely evacuate the inner cavity of the test piece along the original route.

[0062] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A device for measuring the inner surface of a special-shaped engine cavity, characterized in that: It comprises a rotating optical fiber probe (1), a stepping trolley (2), a spiral core optical fiber (3) and a signal control processing unit (4); The rotating optical fiber probe (1) is mounted on the stepping carriage (2) and is used to scan the inner wall of the cavity of the test piece (5); The stepping carriage (2) is electrically connected to the signal control processing unit (4) and is used to drive the rotating optical fiber probe (1) to move forward in the cavity of the test piece (5); One end of the spiral core optical fiber (3) is connected to the rotating optical fiber probe (1), and the other end is connected to the signal control processing unit (4), and is used to transmit the optical signal detected by the rotating optical fiber probe (1) to the signal control processing unit (4); The signal control processing unit (4) is used to control the stepping trolley (2) to move forward, control the rotating optical fiber probe (1) to perform scanning detection, and receive and process optical signals detected by the rotating optical fiber probe (1); The stepping trolley (2) comprises a first mounting plate (21), a second mounting plate (22), N magnetic wheels (23) and N drive units (24), where N is greater than or equal to 3; The magnetic wheel (23) comprises a cylindrical wheel body; an outer surface of the wheel body is provided with oblique spiral patterns; The first mounting plate (21) and the second mounting plate (22) are respectively located at two ends of the N magnetic wheels (23); the N magnetic wheels (23) are evenly distributed around the same central axis between the first mounting plate (21) and the second mounting plate (22); the axles at both ends of the magnetic wheels (23) are respectively rotatably connected to the first mounting plate (21) and the second mounting plate (22); The rotating optical fiber probe (1) is fixed at the center of the first mounting plate (21) and is coaxial with the central axis, with a detection end thereof being located outside the first mounting plate (21) and the other end passing through the first mounting plate (21) and connected to one end of the spiral core optical fiber (3) passing through the second mounting plate (22); N of the driving units (24) are mounted between the first mounting plate (21) and the second mounting plate (22), and are located between the N magnetic wheels (23); the N driving units (24) correspond to the N magnetic wheels (23) one by one; the driving units (24) are electrically connected to the signal control processing unit (4) and are used to drive the corresponding magnetic wheels (23) to rotate; The driving unit (24) comprises a driving motor (241) and a belt (242); The drive motor (241) is fixedly mounted between the first mounting plate (21) and the second mounting plate (22), and is located between the N magnetic wheels (23); the drive motor (241) is electrically connected to the signal control processing unit (4); the rotation axis of the drive motor (241) and the axle of the magnetic wheel (23) are parallel to each other; a driving pulley is provided on the rotation axis of the drive motor (241), a driven pulley is provided on the axle of the magnetic wheel (23), and the belt (242) is sleeved on the driving pulley and the driven pulley; Said N=3; The first mounting plate (21) and the second mounting plate (22) are both equilateral triangles; The three magnetic wheels (23) are rotatably connected to three corners of the first mounting plate (21) and the second mounting plate (22) respectively.

2. The device for measuring the profile of an irregular engine inner cavity according to claim 1, characterized in that: A mounting tube (25) and a triangular tube (26) are also provided between the first mounting plate (21) and the second mounting plate (22); The central axis of the mounting tube (25) is parallel to the central axis of the magnetic wheel (23), one end of the mounting tube (25) is fixedly connected to the first mounting plate (21), the other end of the mounting tube (25) is fixedly connected to one end of the triangular tube (26), and the other end of the triangular tube (26) is fixedly connected to the second mounting plate (22); The other end of the rotating optical fiber probe (1) passes through the first mounting plate (21) and extends into the mounting tube (25); One end of the spiral core optical fiber (3) passes through the second mounting plate (22) and the triangular cylinder (26) in sequence and then extends into the mounting cylinder (25) to be connected to the rotating optical fiber probe (1); The three driving units (24) are respectively fixedly mounted on three side surfaces of the triangular cylinder (26).

3. The device for measuring the profile of an irregular engine inner cavity according to claim 2, characterized in that: The wheel body comprises a cylindrical magnetic core and a tire sleeved outside the magnetic core; The tire is provided with the oblique spiral pattern on the outside.

4. The device for measuring the profile of an irregular engine inner cavity according to claim 3, characterized in that: A plurality of set screws (251) are evenly distributed on the side wall of the mounting cylinder (25); The set screw (251) passes through the side wall of the mounting tube (25) to contact and position the spiral core optical fiber (3) or the rotating optical fiber probe (1).

5. A method for measuring the inner cavity surface of a special-shaped engine, using the device for measuring the inner cavity surface of a special-shaped engine according to any one of claims 1 to 4, characterized in that: The following steps are involved: Step 1: placing the stepping carriage (2) in the cavity of the object to be tested (5); Step 2: Control the stepping carriage (2) to move in stages through the signal control processing unit (4), and control the rotating optical fiber probe (1) to rotate one circle in each stage, so as to obtain the inner cavity surface data of the test piece (5) in each stage; Step 3: splice the surface data acquired at each stage to obtain the inner cavity surface of the tested object (5).

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