CN115248291A

CN115248291A - Magnet body defect detection device and method

Info

Publication number: CN115248291A
Application number: CN202211155669.9A
Authority: CN
Inventors: 陈东; 陈传龙; 周勇; 王茂强
Original assignee: Chengdu To Nan Electronics Co ltd
Current assignee: Chengdu To Nan Electronics Co ltd
Priority date: 2022-09-22
Filing date: 2022-09-22
Publication date: 2022-10-28

Abstract

The invention discloses a magnet body defect detection device and method, and relates to the technical field of body defect detection. The invention detects whether the magnet body has defects by using a volume measuring and calculating method, thereby not only improving the detection speed and enlarging the application range, but also reducing the detection cost, and amplifying the drainage height of the magnet by arranging the U-shaped pipe and the measuring pipe, thereby improving the detection precision.

Description

Magnet body defect detection device and method

Technical Field

The invention relates to the technical field of body defect detection, in particular to a magnet body defect detection device and method.

Background

The rare earth permanent magnet is widely applied to various small and ultra-small motors, nuclear magnetic resonance equipment, electric devices, magnetic separation equipment, magnetic machines, magnetic therapy instruments and other components needing to generate strong gap magnetic fields in the industries of computers, automobiles, instruments, household appliances, petrochemical industry, medical care, aerospace and the like. And the rare earth permanent magnetic material is one of important basic materials for supporting the modern electronic information industry and is closely related to the life of people.

The shape defects of the rare earth permanent magnet mainly comprise: the workpiece with the body quality defect flows into the next production process, so that assembly is blocked and deformed, the quality of an assembly part is influenced, the assembly part can be scrapped and stopped seriously when the workpiece is serious, the production efficiency of an automatic production line is greatly influenced, and the performance of the product can be seriously damaged.

Referring to the prior patent (application number 201810598088. X), a method and a device for detecting magnet body defects are disclosed, firstly, a magnet image to be detected is subjected to binarization processing, secondly, the magnet image subjected to binarization processing is subjected to feature extraction, and according to the extracted image features, the defect type, the defect position and the defect size of the magnet to be detected are determined. And finally, determining whether the magnet to be detected is qualified or not according to the defect position and the defect size of the magnet to be detected.

The above patent implements the detection of the defects of the magnet body by using the image processing technology, but the image processing technology has the following disadvantages: (1) The method is suitable for the magnet with a smooth surface, and if the surface of the magnet has structures such as steps, cambered surfaces and the like, the quality of a shot image can be influenced, so that the detection precision is reduced; (2) Images of all surfaces of the magnet need to be shot, so that the detection speed is reduced; (3) The image processing technology has high software and hardware costs, and not only needs professional technicians to operate, but also needs updating and upgrading, thereby increasing the production cost.

Disclosure of Invention

The invention mainly aims to provide a device and a method for detecting defects of magnet body shapes, which detect whether the magnet body shapes have defects by using a volume measurement method, improve the detection speed, enlarge the application range, reduce the detection cost and effectively solve the problems in the background technology.

In order to achieve the purpose, the invention adopts the technical scheme that:

the magnet body defect detection device comprises a mounting surface, wherein the upper end of the mounting surface is sequentially and fixedly connected with a feeding pipe and a horizontal pipe in a penetrating mode from left to right, a U-shaped pipe is jointly installed between the lower end of the feeding pipe and the lower end of the horizontal pipe, a measuring pipe is installed at the upper end of the horizontal pipe, a first mounting frame and a second mounting frame are installed at the upper end of the mounting surface, the first mounting frame and the second mounting frame are of L-shaped structures, a pressing mechanism is arranged at the upper end of the first mounting frame, the pressing mechanism is located above the feeding pipe, a high-precision liquid level sensor is installed at the front portion of the lower end of the second mounting frame, the high-precision liquid level sensor is located right above the measuring pipe, the measuring end of the high-precision liquid level sensor extends into the measuring pipe, a controller is installed at the upper end of the mounting surface, a display screen is installed at the front end of the controller, an indicating lamp is installed at the upper end of the mounting surface, an opening is located right in front of the feeding pipe, a discharging mechanism is arranged at the lower end of the mounting surface, the discharging mechanism is located right below the opening, and the controller is electrically connected with the pressing mechanism, the high-precision liquid level sensor, the display screen, the indicating lamp, the discharging mechanism and the discharging mechanism are electrically connected with the discharging mechanism.

Preferably, a first baffle ring is installed on the inner wall of the feeding pipe, a second baffle ring is installed on the inner wall of the horizontal pipe, the first baffle ring and the second baffle ring are located on the same horizontal plane, the feeding pipe and the horizontal pipe are identical in shape, and the sectional areas of the U-shaped pipe and the measuring pipe are smaller than the sectional area of the feeding pipe.

Preferably, pressing mechanism includes first electric putter, first electric putter lower extreme and first mounting bracket upper end fixed connection, first electric putter output runs through first mounting bracket and fixed mounting has the clamp plate, two guide posts are installed to the clamp plate upper end, two stoppers have been cup jointed to guide post external surface fixation.

Preferably, the distance from the limiting block at the upper side to the upper end face of the first mounting frame is equal to the distance from the pressing plate to the upper end face of the first baffle ring.

Preferably, discharge mechanism includes the mount, the mount is the U-shaped structure, mount upper end and installation face lower extreme fixed connection, the second electric putter is installed to the mount lower extreme, the mount is run through to second electric putter output and fixed mounting has the fly leaf, suction electro-magnet and repulsion electro-magnet are installed to the fly leaf left end.

Preferably, the feeding pipe, the U-shaped pipe, the horizontal pipe and the measuring pipe are of an integrated structure and jointly form a communicating vessel structure, the inner cavities of the feeding pipe, the U-shaped pipe and the horizontal pipe are filled with liquid, and the upper end face of the liquid is flush with the upper end face of the first baffle ring.

A magnet body defect detection method comprises the following steps:

s1: ensuring that the liquid levels in the feeding pipe and the horizontal pipe are both at the initial liquid level H0, and then placing a magnet waiting for the shape detection into the feeding pipe;

s2: after the magnet sinks to the bottom, a first electric push rod is started through a controller, the output end of the first electric push rod extends and drives the pressing plate to descend until the pressing plate is in close contact with the first baffle ring;

s3, measuring the liquid level height in the measuring pipe through a high-precision liquid level sensor, recording the liquid level height as a measuring height H2, and transmitting the measuring height H2 to a controller;

s4, the controller subtracts the initial height H0 from the measured height H2 to obtain a calculated height Hx, then compares the calculated height Hx with the actual height Hy, if the calculated height Hx is larger than the actual height Hy, the magnet body defect detection is judged to be qualified, meanwhile, a display screen displays a qualified character, and an indicator light displays green; otherwise, judging that the magnet body defect detection is unqualified, and displaying an unqualified character on a display screen and displaying an indicator light in red;

s5, after the detection of the magnet body is completed, the controller starts the attraction electromagnet and the repulsion electromagnet, the attraction electromagnet generates attraction opposite to the magnetism of the magnet, the repulsion electromagnet generates repulsion identical to the magnetism of the magnet, when the attraction and the repulsion are balanced, the magnet is firmly attracted to the position right behind the movable plate 143, the second electric push rod is started, the output end of the second electric push rod extends and drives the movable plate to ascend, the magnet is further driven to move upwards, and the magnet is taken away by a worker until the magnet moves to the position above the feeding pipe.

Preferably, the actual height Hy is a set threshold, the set threshold is a product of a ratio of a calculated volume of the magnet to be detected to a sectional area of the measurement pipe and a set percentage, the calculated volume of the magnet to be detected is a calculated volume assuming that the magnet does not have a shape defect, and the set percentage is changed according to a detection accuracy requirement.

Preferably, after step S5, the height of the liquid level in the measuring tube is measured again by the high-precision liquid level sensor, and if the measured height is greater than the initial height H0, the staff member needs to add liquid until the measured height is equal to the initial height H0.

Compared with the prior art, the invention has the following beneficial effects:

1. according to the method, whether the magnet body has defects is judged through a volume measurement algorithm, during detection, only a magnet to be detected is placed into a feeding pipe, then a pressing mechanism is started, the raised liquid level in the feeding pipe is lowered to the initial liquid level, then the liquid level height in the measuring pipe is measured through a high-precision liquid level sensor, finally the height difference in the measuring pipe after the magnet is fed is calculated through a controller, then the height difference is compared with a set threshold value, if the height difference is smaller than the set threshold value, the detection result of the magnet body is judged to be unqualified, the whole detection process is simple and convenient, the detection efficiency is high, and the method is suitable for detecting the defects of the magnet body in different forms.

2. According to the invention, the feeding pipe, the U-shaped pipe, the horizontal pipe and the measuring pipe are arranged to jointly form the communicating vessel structure, when the magnet is positioned in the feeding pipe, the liquid levels in the feeding pipe and the horizontal pipe can rise, and then the rising water level in the feeding pipe is transferred into the measuring pipe through the pressing mechanism, so that the drainage height of the magnet can be conveniently measured through the high-precision liquid level sensor, the drainage height obtained by calculating the rising height H1 is avoided, and the detection precision is improved.

3. According to the invention, the U-shaped pipe and the measuring pipe are arranged to enlarge the drainage height of the magnet, the sectional areas of the feeding pipe and the horizontal pipe are the same, and the sectional areas of the U-shaped pipe and the measuring pipe are far smaller than that of the feeding pipe, before the magnet is detected, the initial liquid level H0 is positioned at the junction of the horizontal pipe and the measuring pipe, and after the magnet enters the feeding pipe, the drained liquid directly enters the measuring pipe, so that the lifting height is increased, and the measuring precision is improved.

4. The magnet body defect detection device provided by the invention is low in manufacturing cost and operation difficulty, and is beneficial to popularization and application.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a schematic view of the overall structure of the present invention;

FIG. 2 is a schematic cross-sectional view of a feeding tube and a horizontal tube according to the present invention;

FIG. 3 is a schematic view of the magnet of the present invention before detection, wherein H0 represents the initial height of the liquid level;

FIG. 4 is a schematic view showing a state in the magnet detecting process according to the present invention, in which H1 indicates the rising height of the liquid level;

FIG. 5 is a schematic view showing a state where the detection of the magnet is completed, in which H2 indicates the measured height of the liquid level;

FIG. 6 is a schematic structural diagram of a pressing mechanism according to the present invention;

fig. 7 is a schematic structural diagram of the discharging mechanism of the invention.

In the figure: A. a liquid; B. a magnet; 1. a mounting surface; 2. a feeding pipe; 3. a U-shaped tube; 4. a horizontal tube; 5. a measurement tube; 6. a first mounting bracket; 7. a pressing mechanism; 8. a second mounting bracket; 9. a high precision liquid level sensor; 10. a controller; 11. a display screen; 12. an indicator light; 13. an opening; 14. a discharging mechanism; 15. supporting legs; 21. a first retainer ring; 22. a second retainer ring; 71. a first electric push rod; 72. pressing a plate; 73. a guide post; 74. a limiting block; 141. a fixed mount; 142. a second electric push rod; 143. a movable plate; 144. a suction electromagnet; 145. and a repulsive force electromagnet.

Detailed Description

In order to make the technical means, the creation characteristics, the achievement purposes and the effects of the invention easy to understand, the invention is further explained by combining the specific embodiments.

In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "front", "rear", "both ends", "one end", "the other end", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "disposed," "connected," and the like are to be construed broadly, such as "connected," which may be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in a specific case to those of ordinary skill in the art.

The technical scheme of the invention is further explained by combining the attached drawings.

Example one

As shown in fig. 1 and 2, a magnet body defect detecting device and method includes a mounting surface 1, as a specific embodiment, supporting legs 15 are welded at four corners of a lower end of the mounting surface 1 in this embodiment, a feeding pipe 2 and a horizontal pipe 4 are fixedly connected to an upper end of the mounting surface 1 in sequence from left to right, as a specific embodiment, an upper end of the feeding pipe 2 in this embodiment is rectangular and a lower end thereof is circular, a U-shaped pipe 3 is commonly installed between a lower end of the feeding pipe 2 and a lower end of the horizontal pipe 4, a measuring pipe 5 is installed at an upper end of the horizontal pipe 4, the measuring pipe 5 and the horizontal pipe 4 are vertically arranged, a first mounting frame 6 and a second mounting frame 8 are installed at an upper end of the mounting surface 1, the first mounting frame 6 and the second mounting frame 8 are both L-shaped, a pressing mechanism 7 is installed at an upper end of the first mounting frame 6, the pressing mechanism 7 is located directly above the feeding pipe 2, a high-precision liquid level sensor 9 is installed at a front portion of a lower end of the second mounting frame 8, the high-precision liquid level sensor 9 is located directly above the feeding pipe 2, a measuring mechanism 10 is installed at an upper end of the measuring pipe 1, a height control module 14 for controlling a height of the measuring pipe 1, a height difference display module 13 is installed at a front end of the measuring module 10, a height of the measuring module 14 for controlling the measuring module and a height of the measuring module 13 is installed at a height of the measuring module, a height controlling module 13 for controlling the measuring module, a height controlling the measuring module 10, a height controlling module 10 is installed at a height controlling module 10, a height of the measuring module 10, and the controller 10 is electrically connected with the pressing mechanism 7, the high-precision liquid level sensor 9, the display screen 11, the indicator lamp 12 and the discharging mechanism 14.

Before detection, as shown in fig. 3, liquid is filled in the feeding pipe 2, the U-shaped pipe 3 and the horizontal pipe 4, and the liquid level is at the initial liquid level H0; during detection, as shown in fig. 4 and 5, a magnet is placed into the feeding pipe 2, the first electric push rod 71 is started, the output end of the first electric push rod 71 extends and drives the press plate 72 to descend until the press plate 72 is tightly contacted with the first baffle ring 21, the liquid level height in the measuring pipe 5 is measured through the high-precision liquid level sensor 9 and is recorded as a measured height H2, the measured height H2 is transmitted to the controller 10, the controller 10 subtracts the initial height H0 from the measured height H2 to obtain a calculated height Hx, the calculated height Hx is compared with an actual height Hy, if the calculated height Hx is larger than the actual height Hy, the defect detection of the magnet body is judged to be qualified, meanwhile, the display screen 11 displays a 'qualified' word, and the indicator light 12 is displayed in green; otherwise, the magnet body defect detection is judged to be unqualified, meanwhile, the display screen 11 displays an unqualified character, and the indicator light 12 displays red.

Further, the calculated height Hx is a product of a calculated volume assuming that the magnet does not have the shape defect and a set percentage, specifically, the set percentage is 99.5%.

Further, a first baffle ring 21 is installed on the inner wall of the feeding pipe 2, a second baffle ring 22 is installed on the inner wall of the horizontal pipe 4, as a specific implementation manner, the first baffle ring 21 and the second baffle ring 22 have the same structure in the embodiment, the first baffle ring 21 and the second baffle ring 22 are located on the same horizontal plane, the feeding pipe 2 and the horizontal pipe 4 have the same shape, the sectional areas of the U-shaped pipe 3 and the measuring pipe 5 are both smaller than the sectional area of the feeding pipe 2, as a specific implementation manner, the sectional areas of the U-shaped pipe 3 and the measuring pipe 5 are the same in the embodiment, and the sectional area of the measuring pipe 5 is equal to one fifth of the sectional area of the upper portion of the horizontal pipe 4.

As shown in fig. 6, further, the pressing mechanism 7 includes a first electric push rod 71, a lower end of the first electric push rod 71 is fixedly connected with an upper end of the first mounting frame 6, as a specific implementation manner, in this embodiment, the first electric push rod 71 is fixed on the first mounting frame 6 through a bolt, an output end of the first electric push rod 71 penetrates through the first mounting frame 6 and is fixedly provided with a pressing plate 72, the pressing plate 72 is slidably connected with an inner wall of the feeding pipe 2, two guide posts 73 are installed at an upper end of the pressing plate 72, and two limiting blocks 74 are fixedly sleeved on an outer surface of the guide posts 73.

Further, the distance from the upper side limiting block 74 to the upper end surface of the first mounting frame 6 is equal to the distance from the pressing plate 72 to the upper end surface of the first retaining ring 21, and when the upper side limiting block 74 contacts with the first mounting frame 6, the pressing plate 72 just contacts with the first retaining ring 21.

As shown in fig. 7, further, the discharging mechanism 14 includes a fixed frame 141, the fixed frame 141 is a U-shaped structure, the upper end of the fixed frame 141 is fixedly connected with the lower end of the mounting surface 1, a second electric push rod 142 is installed at the lower end of the fixed frame 141, the output end of the second electric push rod 142 penetrates through the fixed frame 141 and is fixedly installed with a movable plate 143, an attraction electromagnet 144 and a repulsion electromagnet 145 are installed at the left end of the movable plate 143, the attraction electromagnet 144 generates an attraction force opposite to the magnetism of the magnet, the repulsion electromagnet 145 generates a repulsion force identical to the magnetism of the magnet, and when the attraction force is balanced with the repulsion force, the magnet is firmly attracted to the right back of the movable plate 143.

Further, throw material pipe 2, U-shaped pipe 3, level pipe 4 and survey buret 5 and be integrative structure, and constitute the linker structure jointly, throw material pipe 2, U-shaped pipe 3 and 4 inner chambers of level pipe and all fill liquid, and the liquid up end flushes with first fender ring 21 up end.

In the invention, no matter what kind of defects are formed on the surface of the magnet, the volume of the magnet is reduced, whether the shape of the magnet has defects or not can be judged through a volume measurement algorithm, when the detection is carried out, the magnet to be detected is placed into the feeding pipe 2, then the pressing mechanism 7 is started, so that the liquid level raised in the feeding pipe 2 is reduced to the initial liquid level, then the liquid level height in the measuring pipe is measured through the high-precision liquid level sensor 9, finally, the height difference in the measuring pipe 5 after the magnet is put into is calculated through the controller 10, then, the height difference is compared with a set threshold value, if the height difference is smaller than the set threshold value, the detection result of the shape of the magnet is judged to be unqualified, the whole detection process is simple and convenient, the detection efficiency is high, and the method is suitable for detecting the defects of the shapes of the magnets in different shapes.

Example two

A magnet body defect detection method comprises the following steps:

s1: ensuring that the liquid levels in the feeding pipe 2 and the horizontal pipe 4 are both at the initial liquid level H0, and then placing a magnet waiting for body shape detection into the feeding pipe 2, as a specific implementation manner, in this embodiment, the magnet is placed into the feeding pipe 2 through the discharging mechanism 14, the second electric push rod 142 is started, the output end of the second electric push rod 142 extends and drives the movable plate 143 to ascend until the movable plate 143 ascends above the feeding pipe 2, and then the attraction electromagnet 144 and the repulsion electromagnet 145 are started, so that the magnet is firmly attracted right behind the movable plate 143, and then the output end of the second electric push rod 142 contracts, so that the magnet descends into the feeding pipe 2, and the magnet is prevented from colliding with the inner wall of the feeding pipe 2 due to direct placement of the magnet;

s2: after the magnet sinks to the bottom, the controller 10 starts the first electric push rod 71, and the output end of the first electric push rod 71 extends and drives the pressing plate 72 to descend until the pressing plate 72 is in close contact with the first baffle ring 21;

s3, measuring the liquid level height in the measuring tube 5 through the high-precision liquid level sensor 9, recording as a measuring height H2, and transmitting the measuring height H2 to the controller 10;

s4, the controller 10 subtracts the initial height H0 from the measured height H2 to obtain a calculated height Hx, then compares the calculated height Hx with the actual height Hy, if the calculated height Hx is larger than the actual height Hy, the magnet body defect detection is judged to be qualified, meanwhile, a display screen 11 displays a qualified character, and an indicator light 12 displays green; otherwise, judging that the magnet body defect detection is unqualified, and simultaneously displaying an unqualified character on the display screen 11 and displaying red on the indicator light 12;

s5, after the detection of the magnet body is completed, the controller 10 starts the attraction electromagnet 144 and the repulsion electromagnet 145, the attraction electromagnet 144 generates attraction opposite to the magnetism of the magnet, the repulsion electromagnet 145 generates repulsion identical to the magnetism of the magnet, when the attraction and the repulsion are balanced, the magnet is firmly attracted right behind the movable plate 143, the second electric push rod 142 is started, the output end of the second electric push rod 142 extends and drives the movable plate 143 to ascend, the magnet is further driven to move upwards, until the magnet moves to the position above the feeding pipe 2, and a worker takes away the magnet.

Further, the actual height Hy is a set threshold, the set threshold is a product of a ratio of a calculated volume of the magnet to be detected to a sectional area of the measurement pipe 5 and a set percentage, the calculated volume of the magnet to be detected is a calculated volume assuming that the magnet does not have a shape defect, and the set percentage is changed according to a requirement of detection accuracy, as a specific implementation manner, the set percentage in this embodiment is 99.5%.

Further, after step S5, the liquid level inside the measuring pipe 5 is measured again by the high-precision liquid level sensor 9, and if the measured height is greater than the initial height H0, the worker needs to add liquid until the measured height is equal to the initial height H0.

The magnet body defect detection device provided by the invention is low in manufacturing cost, and the detection method is low in operation difficulty and beneficial to popularization and application.

The foregoing shows and describes the general principles and features of the present invention, together with the advantages thereof. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are given by way of illustration of the principles of the present invention, but that various changes and modifications may be made without departing from the spirit and scope of the invention, and such changes and modifications are within the scope of the invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims

1. A magnet body defect detection device comprises a mounting surface (1), and is characterized in that: the utility model discloses a measuring instrument, including installation face (1), feeding pipe (2), horizontal pipe (4), first mounting bracket (6) and second mounting bracket (8), U-shaped pipe (3) are installed jointly to going through fixedly connected with from left to right in proper order to installation face (1) upper end, survey buret (5) are installed to horizontal pipe (4) upper end between feeding pipe (2) lower extreme and horizontal pipe (4) lower extreme, first mounting bracket (6) and second mounting bracket (8) all are L shape structure, first mounting bracket (6) upper end is provided with pressing mechanism (7), pressing mechanism (7) are located feeding pipe (2) directly over, high accuracy level sensor (9) are installed to second mounting bracket (8) lower extreme front portion, high accuracy level sensor (9) are located survey buret (5) directly over, and the measuring terminal of high accuracy level sensor (9) extends to survey buret (5) inside, install face (1) upper end installs controller (10), display screen (11) are installed to controller (10) front end, indicator lamp (12) upper end is installed to controller (10), installation face (1) upper end opening has opening (13) to survey buret (13) directly over, discharge pipe (1) lower extreme (13) is provided with the discharge mechanism (14), discharging mechanism (14) are located under opening (13), controller (10) and pressing means (7), high accuracy level sensor (9), display screen (11), pilot lamp (12) and the equal electric connection of discharging mechanism (14).

2. A magnet feature defect inspection apparatus as claimed in claim 1, wherein: throw material pipe (2) inner wall and install first fender ring (21), level pipe (4) inner wall is installed the second and is kept off ring (22), first fender ring (21) and second keep off ring (22) and are located same horizontal plane, it is the same with level pipe (4) shape to throw material pipe (2), the sectional area of U-shaped pipe (3) and survey buret (5) all is less than the sectional area of throwing material pipe (2).

3. A magnet feature defect inspection apparatus as claimed in claim 2, wherein: pressing means (7) include first electric putter (71), first electric putter (71) lower extreme and first mounting bracket (6) upper end fixed connection, first electric putter (71) output runs through first mounting bracket (6) and fixed mounting has clamp plate (72), two guide posts (73) are installed to clamp plate (72) upper end, guide post (73) surface fixed cover has connect two stopper (74).

4. A magnet body defect inspection apparatus as defined in claim 3, wherein: the distance from the limiting block (74) on the upper side to the upper end face of the first mounting frame (6) is equal to the distance from the pressing plate (72) to the upper end face of the first baffle ring (21).

5. A magnet body defect inspection apparatus as defined in claim 4, wherein: discharge mechanism (14) are including mount (141), mount (141) are the U-shaped structure, mount (141) upper end and installation face (1) lower extreme fixed connection, second electric putter (142) are installed to mount (141) lower extreme, second electric putter (142) output runs through mount (141) and fixed mounting has fly leaf (143), suction electro-magnet (144) and repulsion electro-magnet (145) are installed to fly leaf (143) left end.

6. A magnet body defect inspection apparatus as defined in claim 5, wherein: feeding pipe (2), U-shaped pipe (3), horizontal pipe (4) and survey buret (5) and be an organic whole structure, and constitute the linker structure jointly, feeding pipe (2), U-shaped pipe (3) and horizontal pipe (4) inner chamber all are filled with liquid, and the liquid up end flushes with first fender ring (21) up end.

7. A magnet body defect detection method is characterized by comprising the following steps:

s1: ensuring that the liquid levels in the feeding pipe (2) and the horizontal pipe (4) are both at an initial liquid level H0, and then placing a magnet to be subjected to shape detection into the feeding pipe (2);

s2: after the magnet sinks to the bottom, a first electric push rod (71) is started through a controller (10), the output end of the first electric push rod (71) extends and drives a pressure plate (72) to descend until the pressure plate (72) is in close contact with a first blocking ring (21);

s3, measuring the liquid level height in the measuring tube (5) through the high-precision liquid level sensor (9), recording the liquid level height as a measuring height H2, and transmitting the measuring height H2 to the controller (10);

s4, the controller (10) subtracts the initial height H0 from the measured height H2 to obtain a calculated height Hx, then compares the calculated height Hx with the actual height Hy, if the calculated height Hx is larger than the actual height Hy, the magnet body defect detection is judged to be qualified, meanwhile, a display screen (11) displays a qualified word, and an indicator light (12) displays green; otherwise, judging that the magnet body defect detection is unqualified, and simultaneously displaying an unqualified character on the display screen (11) and displaying red on the indicator light (12);

s5, after the detection of the magnet body is completed, the controller (10) starts the attraction electromagnet (144) and the repulsion electromagnet (145), the attraction electromagnet (144) generates attraction opposite to the magnetism of the magnet, the repulsion electromagnet (145) generates repulsion identical to the magnetism of the magnet, when the attraction and the repulsion are balanced, the magnet is firmly attracted to the position right behind the movable plate 143, the second electric push rod (142) is started, the output end of the second electric push rod (142) extends and drives the movable plate (143) to ascend, the magnet is further driven to move upwards, until the magnet moves to the position above the feeding pipe (2), and a worker takes away the magnet.

8. A magnet feature defect detection method as claimed in claim 7, wherein: the actual height Hy is a set threshold value, the set threshold value is the product of the ratio of the calculated volume of the magnet to be detected to the sectional area of the measuring pipe (5) and a set percentage, the calculated volume of the magnet to be detected is the calculated volume of the magnet which is supposed to have no body defects, and the set percentage is changed according to the requirement of detection accuracy.

9. A magnet feature defect detection method as claimed in claim 7, wherein: after step S5, the level of the liquid in the measuring tube (5) is measured again by the high-precision liquid level sensor (9), and if the measured height is greater than the initial height H0, the staff member needs to add liquid until the measured height is equal to the initial height H0.