CN217058673U

CN217058673U - Device for testing strength of internal movable structure of engine

Info

Publication number: CN217058673U
Application number: CN202220579742.4U
Authority: CN
Inventors: 申立中; 宋健平; 祖菘; 王治; 许煜晨
Original assignee: Kunming University of Science and Technology
Current assignee: Kunming University of Science and Technology
Priority date: 2022-03-17
Filing date: 2022-03-17
Publication date: 2022-07-26
Anticipated expiration: 2032-03-17

Abstract

A device for testing the strength of an internal movable structure of an engine belongs to the field of engine research and detection, and aims to drive a connecting rod to move according to the movement mode in the engine through a motor, thereby driving the piston and the double swing arms to reciprocate in the cylinder sleeve to simulate the actual engine operation scene, arranging an eddy current sensor on the cylinder sleeve, the deformation condition of the cylinder sleeve can be detected, the infrared detector is also arranged outside the cylinder sleeve and can detect the deformation data of the cylinder sleeve outside to compare with the eddy current sensor, the connecting wire of the eddy current sensor is arranged along the connecting rod and the double swing arms and can simulate the situation of the connecting wire of the eddy current sensor in the actual engine, and then carry out the arrangement of connecting wire according to the activity condition of connecting wire, double pendulum arm material and structure can be with trading, detect the performance degradation intensity of different materials and structures, and the device has great meaning to the performance research of whole engine.

Description

Device for testing strength of internal movable structure of engine

Technical Field

A device for testing the strength of an internal movable structure of an engine belongs to the field of engine research and detection.

Background

The deformation of the cylinder sleeve is generally predicted by calculation through a finite element analysis method, so that data which are difficult to measure in a test are obtained. Because the deformation of the cylinder sleeve is the result of the coupling effect of multiple physical fields, the influence factors are numerous, and the accuracy of the calculation result is influenced by the simplification of modeling and the differentiation of analysis hypothesis. Therefore, the deformation of the cylinder sleeve is tested and analyzed by adopting a testing technology, accurate boundary conditions can be provided for calculation, and a finite element analysis model can be corrected, so that the calculation accuracy is improved. Because the cylinder sleeve-piston friction pair is arranged in the engine, the arrangement of the sensor and the data output are difficult, the deformation test of the cylinder sleeve is always a difficult point of the test work, and particularly the related test work of the dynamic working deformation of the cylinder sleeve is rarely developed.

The deformation data of the general cylinder sleeve is directly obtained by actual measurement under the static state after the assembly and the work of a machine body assembly, and engine manufacturers at home and abroad usually adopt a three-dimensional measuring instrument to carry out the static deformation test of the cylinder sleeve and mainly serve as an on-line monitoring or batch sampling inspection means for controlling the cold machining or the assembly quality of an engine body. The static deformation measurement analysis can know the machining and manufacturing tolerance and the influence of the pre-tightening force of the evaluation bolt on the deformation of the cylinder sleeve, and the static deformation measurement of the heated assembly body can also know the thermal deformation condition of the cylinder sleeve caused by different materials and working temperatures and the influence of the difference of the thermal expansion coefficients. The measurement data are obtained statically in the engine, ignoring differences in component temperatures caused by combustion and mechanical loads generated by gas pressure in the engine.

Because a precision measuring instrument is expensive in price and can only measure static data of cylinder sleeve deformation, and for an engine in a working state, the method cannot be used for obtaining the data of the cylinder sleeve deformation, the study on the dynamic cylinder sleeve deformation mainly adopts an eddy current sensor, a strain gauge sensor and the like to directly or indirectly measure, and then data processing is carried out to obtain the actual deformation of the cylinder sleeve.

The eddy current sensor is adopted to directly test the dynamic deformation of the cylinder sleeve in a heat engine state, the eddy current sensor is required to be installed on a piston inside an engine, the piston can reciprocate relative to the cylinder sleeve in an operating state of the engine, but the eddy current sensor is arranged inside the engine, the deformation of the engine is weak and can not be known by naked eyes, and meanwhile, the precision and the accuracy of the eddy current sensor in the working process can not be known, so that in order to verify whether the eddy current sensor can accurately measure the gap between the piston and the cylinder sleeve in the moving process, a set of reciprocating motion device is designed to simulate the moving state of the piston between the cylinder sleeves, and the precision of the eddy current sensor is obtained by comparing data measured outside with the data of the eddy current sensor.

The eddy current sensor is arranged inside the engine, and because the eddy current sensor needs to be arranged into a wired connection, and the inside of the engine has a plurality of movable structures, if the connecting wire of the eddy current sensor is unreasonable in arrangement, the connecting wire can be wound on the movable structure inside the engine, so that a device for verifying whether the connecting wire is stable under the work of the engine needs to be arranged.

The double swing arms are main movable devices in the engine, so the performance of the double swing arms is very important to the running state of the engine, the effect of the double swing arms is neglected in many researches, and a detection state for the performance of the double swing arms is also set in the researches.

The invention content is as follows:

the utility model provides a device of inside active structure intensity of test engine, its purpose goes to simulate the state of engine when moving through the device of establishing certainly, put eddy current sensor on the piston, again set up infrared detector outside the cylinder liner, two data contrasts, judge the eddy current sensor precision, in addition because the inside eddy current sensor's of engine connecting wire is connected to the external world through connecting rod and double pendulum arm, so still be provided with double pendulum arm, fix the eddy current sensor connecting wire on double pendulum arm, it is stable to go to observe the pencil under motion state.

The utility model adopts the technical proposal that: the utility model provides a device of inside active structure intensity of test engine which characterized in that: comprises the following steps: the device comprises a cylinder sleeve, a cylinder sleeve supporting frame, a piston, an eddy current sensor carrier, an eddy current sensor connecting wire, a connecting rod, a rotating disk, a double-swing arm, a driving motor, a motor fixing frame, a rotating shaft, a piston fixing rod, a double-swing arm fixing frame, a rotating disk fixing bolt, an infrared detector and a bearing platform, wherein the cylinder sleeve, the piston and the double-swing arm are original parts of an engine, the lower part of the cylinder sleeve supporting frame is fixed on the bearing platform, and the upper part of the cylinder sleeve supports the cylinder sleeve; the piston and the connecting rod are fixed through a piston fixing rod, an eddy current sensor carrier is arranged at the top of the connecting rod and comprises a fixing disc and a hollow pipeline, the side face of the head of the piston is perforated, the hollow pipeline penetrates through a hole in the piston, a driving motor is fixed on a motor fixing frame through a bolt, the driving motor is connected with a rotating shaft, the other end of the rotating shaft is connected with the rotating disc, the driving motor drives the rotating shaft to rotate when working and further drives the rotating disc to rotate, the rotating disc consists of two parts, and the two parts are connected and fixed through a rotating disc fixing bolt; the infrared detector is characterized in that a small hole is formed in the bent position of the middle of the connecting rod, a sliding structure is arranged in the small hole, a rotating disk fixing bolt penetrates through the hole, the rotating disk fixing bolt and the hole slide relatively, the bottom of the connecting rod is connected with one end of the double swing arm, the other end of the double swing arm is connected with the double swing arm fixing frame, the double swing arm fixing frame is fixed on the bearing table, the infrared detector is arranged outside the cylinder sleeve, the eddy current sensor is arranged at the pipe opening of the hollow pipeline, an eddy current sensor connecting wire is connected with the eddy current sensor, the eddy current sensor is arranged in the hollow pipeline on a carrier of the eddy current sensor, one strand of the wire of the strand of the wire.

Further, when the engine works, the driving motor drives the rotating disc to rotate through the rotating shaft, the rotating disc drives the connecting rod to swing in a reciprocating mode, the head portion, connected with the piston, of the connecting rod drives the piston and the eddy current sensor to do left-right reciprocating motion in the cylinder sleeve, the tail portion, connected with the double swing arms, of the connecting rod drives the double swing arms to do back-and-forth swinging motion, and the motion of the piston and the double swing arms is consistent with that of the piston and the double swing arms when the engine works.

Further, because the eddy current sensor sets up on the eddy current sensor carrier, so detected the distance of eddy current sensor and cylinder liner when doing left and right reciprocating motion, and eddy current sensor itself fixes on the eddy current sensor carrier, so gather the interval change with the cylinder liner and be exactly the deformation of cylinder liner self, and infrared detector sets up in the cylinder liner outside, detect the cylinder liner deformation from the outside, eddy current sensor passes through the eddy current sensor connecting wire and is connected to on the computer, infrared detector also is connected to on the computer, the computer compares both data, can judge the precision of eddy current sensor.

Furthermore, the infrared detector sets up the mount on cylinder liner outside both sides, and the infrared detector can move about along piston reciprocating direction on the mount, and the infrared detector is the structure that two concentric rings formed, and inner ring and outer ring can rotate each other, and infrared detection device sets up the deformation that is used for detecting the cylinder liner on the inner ring inner wall, and the outer loop is connected with the mount, can move about and self relative rotation can realize the detection to the whole positions of cylinder liner outer wall through outer loop ability and mount in piston reciprocating direction.

Furthermore, the eddy current sensor is arranged on the piston at the same position as the device in an engine experiment, and the connecting line of the eddy current sensor is led out along the double swing arms on the engine, so that the connecting line of the eddy current sensor in the device is led out through the connecting rod and then arranged along the double swing arms, and the stability of the connecting line of the eddy current sensor in an actual experiment is verified.

Furthermore, the double swing arms are connected with the connecting rod and the double swing arm fixing frame through bolts, so that the double swing arms can be detached, the materials and the structures of the double swing arms can be replaced, and the change of the performance of the double swing arms made of different materials or with different structures under the running condition of the engine can be verified.

Furthermore, the diameter of the hole on the piston is larger than that of the hollow pipeline, and the hole and the diameter are not in contact with each other, so that the influence of vibration on the precision of the eddy current sensor during the movement of the piston is avoided.

Furthermore, the eddy current sensor carrier and the connecting rod are fixed by fixing discs on the eddy current sensor carrier and the connecting rod, the number of the fixing discs is one, the outer ring is provided with a plurality of hole sites for installing hollow pipelines, and the number of the hollow pipelines can be installed and the extension length of the hollow pipelines on the fixing discs can be adjusted according to requirements.

Furthermore, the position that infrared detector detected and eddy current sensor detected is the same position, and the position quantity that infrared detector detected is confirmed according to eddy current sensor's quantity, and both detect same position, because the cylinder liner is the cylinder, and have deformation, so when the check point was around the cylinder liner round, the figure that forms was similar an irregular circle, and the irregular circle that forms is formed for the data fitting that detects this point separately.

Further, eddy current sensor and infrared detector one-to-one, detect same position, eddy current sensor and infrared detector multiple spot set up, the observation personnel carry out the analysis to each point, if the error is less between the two, within the acceptance range, can judge that eddy current sensor's precision meets the requirements, if the error is great, exceed the acceptance range, then can judge that eddy current sensor's precision is not conform to the requirements, and can judge that it is the eddy current sensor of which position to have a problem according to the point that forms, and then analyze to these problems, with the precision that improves eddy current sensor.

The device for testing the strength of the movable structure in the engine comprises the following operation methods:

the method comprises the following steps: the device can realize three detections of the precision of the eddy current sensor, the stability degree of the connecting wire and the performance of the double swing arms, and can be used for selecting one device or a plurality of devices simultaneously according to the shape of the device to be made;

step two: determining the shape of the device, and starting a driving motor to enable the device to be in a working state;

step three: observing the condition of the experiment, and if the accuracy of the eddy current sensor is high, looking at the comparison data between the computer and the infrared detector; if the connection line is stable, watching whether the connection line is thrown off; if the double-swing arm performance is achieved, analyzing the state of the double-swing arm during the experiment and comparing and analyzing the structural strength and other performances of the double-swing arm after the experiment;

step four: and after the experiment is finished, the driving motor is turned off, the power is cut off, and the subsequent data is analyzed and processed.

Compared with the prior art, the utility model has the advantages of it is following: 1. the prior art only utilizes a device or a method for detecting the cylinder sleeve by using sensors such as an eddy current sensor and the like, and lacks the verification of the methods, the utility model discloses innovatively provides a device and a method for verifying the accuracy of the eddy current sensor; 2. the device is provided with the movable infrared detector, so that the detection area can be increased, and the device is convenient to be matched with an eddy current sensor for use; 3. if the eddy current sensor is in wired connection, the circuit needs to be led out from the inside of the engine, and because a movable device exists in the engine, the circuit is easy to wind on the movable device, and the stability of the circuit needs to be ensured; 4. the double swing arms of different materials, structure are influential to the operating mode of engine, lack relevant equipment at present, the utility model provides a device that can supply the analysis.

Description of the drawings:

FIG. 1 is an overall structure diagram of the present invention;

fig. 2 is a front view of the present invention;

fig. 3 is a schematic view of the driving mechanism of the movable structure of the present invention;

fig. 4 is a schematic view of the movable body of the present invention;

FIG. 5 is a schematic view of the connection and driving of the rotating disc according to the present invention;

FIG. 6 is a diagram of a carrier structure of the eddy current sensor on the connecting rod of the present invention;

fig. 7 is a partial cross-sectional view of the piston of the present invention;

FIG. 8 is a schematic diagram of the infrared detector of the present invention;

fig. 9 is a front view of the eddy current sensor carrier of the present invention;

fig. 10 is a cross-sectional view of the eddy current sensor carrier according to the present invention.

The reference numbers in the figures: 1-cylinder sleeve; 2. a cylinder sleeve support frame; 3-a piston; 4-an eddy current sensor; 5-an eddy current sensor carrier; 501-fixing a disc; 502-hollow conduit; 6. an eddy current sensor connecting wire; 7-a connecting rod; 8-rotating the disc; 9-double swing arm; 10-a drive motor; 11-motor fixing frame; 12-a rotating shaft; 13-a piston fixing rod; 14 double swing arm fixing frames; 15-rotating disc fixing bolts; 16-an infrared detector; 17-carrying platform.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be further described with reference to the accompanying drawings in combination with the following embodiments. It should be understood that the description is intended for purposes of illustration only and is not intended to limit the scope of the present disclosure. Moreover, in the following description, descriptions of well-known structures and techniques are omitted so as to not unnecessarily obscure the concepts of the present invention.

Please refer to fig. 1-10, the utility model provides a device of test engine inside active structure intensity, its purpose is through the device of establishing remove the state of simulation engine when the operation, put eddy current sensor 4 on piston 3, set up infrared detector 16 again in 2 outsides of cylinder liner, two data contrast, judge the accuracy of eddy current sensor 4, in addition because the inside eddy current sensor 4's of engine connecting wire is connected to the external world through double swing arm 9, so still be provided with double swing arm 9, fix eddy current sensor connecting wire 6 on double swing arm 9, it is stable to go to observe the pencil under the motion state.

The utility model adopts the technical proposal that: the utility model provides a device of inside active structure intensity of test engine which characterized in that: comprises the following steps: the device comprises a cylinder sleeve 1, a cylinder sleeve supporting frame 2, a piston 3, an eddy current sensor 4, an eddy current sensor carrier 5, an eddy current sensor connecting wire 6, a connecting rod 7, a rotary disk 8, a double-swing arm 9, a driving motor 10, a motor fixing frame 11, a rotary shaft 12, a piston fixing rod 13, a double-swing arm fixing frame 14, a rotary disk fixing bolt 15, an infrared detector 16 and a bearing table 17, wherein the cylinder sleeve 1, the piston 3 and the double-swing arm 9 are original parts of an engine, the lower part of the cylinder sleeve supporting frame 2 is fixed on the bearing table 17, and the upper part supports the cylinder sleeve 1; the piston 3 and the connecting rod 7 are fixed through a piston fixing rod 13, the top of the connecting rod 7 is provided with an eddy current sensor carrier 5, the eddy current sensor carrier 5 comprises a fixing disc 501 and a hollow pipeline 502, the side surface of the head of the piston 3 is perforated, the hollow pipeline 501 penetrates through a hole in the piston 3, a driving motor 10 is fixed on a motor fixing frame 11 through a bolt, the driving motor 10 is connected with a rotating shaft 12, the other end of the rotating shaft 12 is connected with a rotating disc 8, the driving motor 10 drives the rotating shaft 12 to rotate when working, and further drives the rotating disc 8 to rotate, the rotating disc 8 comprises two parts, and the two parts are connected and fixed through a rotating disc fixing bolt 15; the position of connecting rod 7 middle part bending is provided with the aperture, the aperture is provided with sliding structure, rotary disk fixing bolt 15 passes this hole, rotary disk fixing bolt 15 and this hole relative slip, connecting rod 7 bottom is connected with double-swing arm 9 one end, double-swing arm 9 other end is connected with double-swing arm mount 14, double-swing arm mount 14 is fixed on plummer 17, infrared detector 16 sets up in the cylinder liner 1 outside, eddy current sensor 4 sets up the mouth of pipe at cavity pipeline 501, eddy current sensor connecting wire 6 is connected with eddy current sensor 4, set up in cavity pipeline 502 on eddy current sensor carrier 5, assemble into one strand in fixed disk 501 department, fix and draw on connecting rod 7, be connected to the computer.

Further, during operation, the driving motor 10 drives the rotating disc 8 to rotate through the rotating shaft 12, the rotating disc 8 drives the connecting rod 7 to swing in a reciprocating mode, the head portion, connected with the piston 3, of the connecting rod 7 drives the piston 3 and the eddy current sensor 4 to reciprocate left and right in the cylinder sleeve 1, the tail portion, connected with the double swing arm 9, of the connecting rod 7 drives the double swing arm 9 to swing back and forth, and the actions of the piston 3 and the double swing arm 9 are consistent with those of the piston 3 and the double swing arm 9 during operation in the engine.

Further, because the eddy current sensor 4 is arranged on the eddy current sensor carrier 5, the distance between the eddy current sensor 4 and the cylinder sleeve 1 is detected when the left-right reciprocating motion is performed, the eddy current sensor 4 is fixed on the eddy current sensor carrier 5, the change of the distance between the acquired object and the cylinder sleeve 1 is the deformation of the cylinder sleeve 1, the infrared detector 16 is arranged outside the cylinder sleeve 1 and is used for detecting the deformation of the cylinder sleeve 1 from the outside, the eddy current sensor 4 is connected onto a computer through an eddy current sensor connecting wire 6, the infrared detector 16 is also connected onto the computer, the computer compares the data of the eddy current sensor 4 and the data of the infrared detector with the data of the cylinder sleeve 1, and the accuracy of the eddy current sensor 4 can be judged.

Further, infrared detector 16 sets up the mount on cylinder liner 1 outside both sides, and infrared detector 16 can move about along piston 3 reciprocating motion direction on the mount, and infrared detector 16 is the structure that two concentric rings formed, and inner ring and outer ring can rotate each other, and infrared detection device sets up the deformation that is used for detecting cylinder liner 1 on the inner wall of inner ring, and the outer loop is connected with the mount, can move about and self relative rotation can realize the detection to the whole positions of cylinder liner 1 outer wall through outer loop ability and mount in piston 2 reciprocating direction.

Further, the eddy current sensor 4 is arranged on the piston 3 at the same position as the device in an engine experiment, and the eddy current sensor connecting wire 6 is led out from the engine along the double swing arm 9, so that the eddy current sensor connecting wire 6 in the device is led out through the connecting rod 7 and then is arranged along the double swing arm 9, and the stability of the eddy current sensor connecting wire 6 in an actual experiment is verified.

Furthermore, the double swing arms 9 are connected with the connecting rod 7 and the double swing arm fixing frame 14 through bolts, the double swing arms are detachable, materials and structures of the double swing arms 9 can be replaced, and performance changes of the double swing arms 9 made of different materials or different structures under the condition that the engine runs are verified.

Furthermore, the diameter of the hole on the piston 3 is larger than that of the hollow pipeline 502, and the hole and the hollow pipeline are not in contact with each other, so that the influence of vibration on the precision of the eddy current sensor 4 when the piston 3 moves is avoided.

Further, the eddy current sensor carrier 5 and the connecting rod 7 are fixed by fixing discs 501 and the connecting rod 7 on the eddy current sensor carrier 5, the number of the fixing discs 501 is one, the outer ring is provided with a plurality of hole sites for installing the hollow pipelines 502, and the number of the hollow pipelines 502 and the extension length of the hollow pipelines 502 on the fixing discs 501 can be adjusted according to requirements.

Further, the position that infrared detector 16 detected and eddy current sensor 4 detected is the same position, and the position quantity that infrared detector 16 detected is confirmed according to the quantity of eddy current sensor 4, and both detect same position, because cylinder liner 1 is the cylinder, and has deformation, so when the check point was around cylinder liner 1 round, the graph that forms was similar an irregular circle, and the irregular circle that forms is the data fit that detects this point separately and forms.

Further, eddy current sensor 4 and infrared detector 16 one-to-one detect same position, eddy current sensor 4 and infrared detector 16 multiple spot set up, the observer carries out the analysis to each point, if the error between the two is less, within the acceptance range, can judge that eddy current sensor 4's precision meets the requirements, if the error is great, exceed the acceptance range, then can judge that eddy current sensor 4's precision does not meet the requirements, and can judge that it is eddy current sensor 4 of which position has the problem according to the point that forms, and then analyze to these problems, with the precision that improves eddy current sensor 4.

It is to be understood that the above-described embodiments of the present invention are merely illustrative of or explaining the principles of the invention and are not to be construed as limiting the invention. Therefore, any modification, equivalent replacement, improvement and the like made without departing from the spirit and scope of the present invention should be included in the protection scope of the present invention. Further, it is intended that the appended claims cover all such variations and modifications as fall within the scope and boundaries of the appended claims, or the equivalents of such scope and boundaries.

Claims

1. The utility model provides a device of inside active structure intensity of test engine which characterized in that: comprises the following steps: the device comprises a cylinder sleeve (1), a cylinder sleeve support frame (2), a piston (3), an eddy current sensor (4), an eddy current sensor carrier (5), an eddy current sensor connecting wire (6), a connecting rod (7), a rotating disc (8), a double-swing arm (9), a driving motor (10), a motor fixing frame (11), a rotating shaft (12), a piston fixing rod (13), a double-swing arm fixing frame (14), a rotating disc fixing bolt (15), an infrared detector (16) and a bearing table (17); the cylinder sleeve (1), the piston (3) and the double swing arm (9) are original parts of the engine, the lower part of the cylinder sleeve support frame (2) is fixed on the bearing platform (17), and the upper part supports the cylinder sleeve (1); the piston (3) and the connecting rod (7) are fixed through a piston fixing rod (13), an eddy current sensor carrier (5) is arranged at the top of the connecting rod (7), the eddy current sensor carrier (5) comprises a fixing disc (501) and a hollow pipeline (502), a hole is formed in the side face of the head of the piston (3), and the hollow pipeline (502) penetrates through the hole in the piston; the driving motor (10) is fixed on the motor fixing frame (11) through a bolt, the driving motor (10) is connected with the rotating shaft (12), and the other end of the rotating shaft (12) is connected with the rotating disk (8); the position of connecting rod (7) middle part bending is provided with the aperture, the aperture is provided with sliding construction, this hole is passed in rotary disk fixing bolt (15), connecting rod (7) bottom is connected with double pendulum arm (9) one end, double pendulum arm (9) other one end is connected with double pendulum arm mount (14), double pendulum arm mount (14) are fixed on plummer (17), infrared detector (16) set up in the cylinder liner outside, eddy current sensor (4) set up the mouth of pipe at cavity pipeline (502).

2. The apparatus for testing the strength of an internal moving structure of an engine as claimed in claim 1, wherein: the eddy current sensor connecting wire (6) is connected with the eddy current sensor (4), the eddy current sensor carrier (5) is arranged in the hollow pipeline (502), and is converged into one strand at the fixed disc (501), fixed on the connecting rod (7), led out of the double swing arm (9) and connected to a computer.

3. The apparatus for testing the strength of an internal moving structure of an engine as set forth in claim 1, wherein: the infrared detector (16) is provided with a fixing frame on two sides of the outer side of the cylinder sleeve (1), the infrared detector (16) can move left and right on the fixing frame along the reciprocating motion direction of the piston, the infrared detector (16) is a structure formed by two concentric rings, an inner ring and an outer ring can rotate mutually, the infrared detection device is arranged on the inner wall of the inner ring, and the outer ring is connected with the fixing frame.

4. The apparatus for testing the strength of an internal moving structure of an engine as set forth in claim 1, wherein: the connection of the double swing arms (9) and the connecting rod (7) and the connection of the double swing arms and the double swing arm fixing frame (14) are both connected through bolts and can be disassembled.

5. The apparatus for testing the strength of an internal moving structure of an engine as claimed in claim 1, wherein: the rotating disc is composed of two parts which are connected and fixed through a rotating disc fixing bolt (15).

6. The apparatus for testing the strength of an internal moving structure of an engine as claimed in claim 1, wherein: the diameter of the hole on the piston (3) is larger than the diameter of the hollow pipeline (502) and the hole does not contact with each other.

7. The apparatus for testing the strength of an internal moving structure of an engine as claimed in claim 1, wherein: the eddy current sensor carrier (5) and the connecting rod (7) are fixed by fixing discs (501) on the eddy current sensor carrier (5) and the connecting rod (7), the number of the fixing discs (501) is one, and the outer ring is provided with a plurality of hole sites for installing hollow pipelines (502).