CN113358333A

CN113358333A - High-precision agricultural machinery headlamp detector

Info

Publication number: CN113358333A
Application number: CN202110649071.4A
Authority: CN
Inventors: 臧传军; 曲盛林; 樊玉建; 张芮菘; 李玉新; 李钟祥; 郭微微; 宋宪勇; 张鸿川; 杨志芹; 赵敏
Original assignee: Shandong Keda Microcomputer Application Research Institute Co ltd
Current assignee: Shandong Keda Microcomputer Application Research Institute Co ltd
Priority date: 2021-06-10
Filing date: 2021-06-10
Publication date: 2021-09-07
Anticipated expiration: 2041-06-10
Also published as: CN113358333B

Abstract

The invention relates to a high-precision agricultural machinery headlamp detector, and belongs to the field of detection. The device comprises a transverse rail, wherein a rotating shaft is fixed in the middle of the lower end face of the transverse rail and is installed in a shaft seat, the shaft seat is fixed on the ground, the transverse rail is parallel to the ground, and two ends of the transverse rail are respectively provided with a set of clamping and positioning devices. The lens of the detector can be guaranteed to be right opposite to the headlamp through one-time parking, the longitudinal line of the vehicle is perpendicular to the lens, the vehicle does not need to be moved back and forth, the detection precision is high, and the detection efficiency is high.

Description

High-precision agricultural machinery headlamp detector

Technical Field

The invention relates to a high-precision agricultural machinery headlamp detector, and belongs to the field of detection.

Background

With the rapid development of agricultural mechanization in vast rural areas in China, the number of agricultural machines is greatly increased. Meanwhile, higher requirements are also provided for the safety performance detection of agricultural machinery. According to the agricultural department document of the people's republic of China and related national standards, a device which is convenient for rural and people-friendly services under all levels of agricultural machinery supervision departments and can detect the luminous intensity and the optical axis offset of the headlamp of large, medium and small agricultural machinery vehicles is developed to meet urgent needs.

Currently, a portable headlamp inspection apparatus is commonly used, such as that disclosed in patent publication No. CN 202229905U. When the detector is used for detecting, the lens of the detector needs to be over against the headlamp, and the longitudinal line of the vehicle needs to be perpendicular to the lens, so that the detection accuracy can be ensured. In order to meet the above requirements, it is now common to mark a vehicle guide line on the ground, and the distance between two wheels on the same side and the guide line is kept the same when parking, so that the longitudinal line of the vehicle needs to be perpendicular to the lens. However, it is difficult for a person to determine the position of the wheels in the driver's seat, and the vehicle is often parked obliquely, resulting in inaccurate detection.

In addition, present detector makes the camera lens of detector just to the head-light through the infrared ray, but the car light dustcoat is transparent, and the infrared ray shines that the light spot is very shallow on the lamp shade, is difficult to observe, receives light bowl reflection influence sometimes and leads to the location failure, and positioning efficiency is not high. The bulb has certain distance to the lamp shade, and its distance of different motorcycle types is also different, and this has also influenced the detection precision to a certain extent.

Disclosure of Invention

According to the defects in the prior art, the technical problems to be solved by the invention are as follows: the high-precision agricultural machinery headlamp detector can ensure that the lens of the detector is vertical to the headlamp and the longitudinal line of a vehicle in a driving process by parking once, the vehicle does not need to be moved back and forth, the detection precision is high, and the detection efficiency is high.

The invention relates to a high-precision agricultural machinery headlamp detector which comprises a transverse rail, wherein a rotating shaft is fixed in the middle of the lower end surface of the transverse rail, the rotating shaft is arranged in a shaft seat, the shaft seat is fixed on the ground, the transverse rail is parallel to the ground, and two ends of the transverse rail are respectively provided with a set of clamping and positioning devices;

the clamping and positioning device comprises a positioning sliding block, the positioning sliding block is matched on the transverse rail, a longitudinal rail is fixed on the positioning sliding block, and the longitudinal rail is perpendicular to the transverse rail and parallel to the ground;

still set up the removal slider on the horizontal rail, remove the slider and be located between two clamping position device, fixed lifter on the removal slider, lifter and horizontal rail and ground are all perpendicular, the fixed detector in lifter upper end, and the camera lens axis of detector is parallel with indulging the rail.

The working principle and the process are as follows:

during operation, two clamping and positioning devices are separated, then a vehicle is stopped between the clamping and positioning devices, and positioning sliding blocks of the two clamping and positioning devices slide towards the middle, so that a longitudinal rail of the clamping and positioning devices is in contact with two tires on the same side, and a transverse rail rotates around a rotating shaft in order to be matched with the contact between the longitudinal rail and the tires. When the longitudinal rails on the two sides are in contact with the front tire and the rear tire on the corresponding side at the same time, the driving longitudinal line of the vehicle is just vertical to the lens of the detector. The sliding block slides on the transverse rail, and the lifting rod is adjusted simultaneously, so that the axis of the lens of the detector coincides with the axis of the bulb, and then detection can be performed. Whether the vehicle stops or not is inclined, the longitudinal line of the vehicle can be quickly perpendicular to the lens, the detection efficiency can be improved, errors can be greatly reduced, and the detection is more accurate.

The movable sliding block is fixed with a small rail, the small rail is perpendicular to the transverse rail and parallel to the ground, the small rail is matched with the small sliding block, and the telescopic rod is fixed on the small sliding block. Therefore, the detector can be moved forwards and backwards conveniently, the distance between the detector and the car lamp can be controlled conveniently, and the car does not need to be moved forwards and backwards.

The upper surface of the detector shell is hinged with a mandril, the mandril is vertical to the transverse rail, and the mandril is parallel to the axis of the detector lens. When the detection device is used, the ejector rod is rotated to the front of the detection device, then the lifting rod is adjusted to enable the ejector rod to be located above a cover of a head of the agricultural machine, then the ejector rod is observed from the position right above the ejector rod, the sliding block is moved in a translation mode, when the ejector rod is aligned with the bulb, the axis of a lens of the detection device is parallel to the axis of the bulb, and the plane where the two axes are located is perpendicular to the transverse rail. The little slider of translation, people's eye follow car light side is observed for the ejector pin tip is located directly over the bulb, and the distance of bulb to the camera lens is the distance of ejector pin tip to camera lens promptly this moment, consequently can come the distance of short-term determination camera lens to bulb through the ejector pin length, and not only the location is accurate, fixes a position rapidly moreover. Because the end part of the ejector rod is closer to the bulb and only separates from the lampshade, the accurate positioning can be rapidly carried out through visual inspection, and the accuracy and the efficiency are greatly improved.

The ejector pin is the square pole, cooperation square sleeve on the ejector pin, and the fixed pole setting in square sleeve lower surface, the vertical fixation horizontal pole in the pole setting, the pole setting is perpendicular with the ejector pin, and the horizontal pole is parallel with the ejector pin to the horizontal pole axis coincides with the camera lens axis. Adjust the level of horizontal pole through the lifter, people's eye is surveyed in the car light side, and the side cover that slides makes the horizontal pole be close to the car light, and when the extension line of horizontal pole passed through the bulb, the camera lens of detector also passed through the bulb this moment, and then realized quick accurate positioning.

Two sets of accurate positioning devices are arranged on the longitudinal rail, each accurate positioning device comprises a sliding sleeve, a transverse shaft is vertically fixed on the inner side surface of the sliding sleeve, the transverse shaft is perpendicular to the longitudinal rail, a positioning block is hinged to the transverse shaft in a matched mode, a through hole is formed in the positioning block, a sliding rod is matched in the through hole and is perpendicular to the transverse shaft, and a magnetic rod is vertically fixed at the end of the sliding rod. The magnetic rods can reach any position in the sliding range of the sliding rod through the rotation of the sliding sleeve and the twitching of the sliding rod, the magnetic rods of the two sets of precise positioning devices are fixedly attracted with the nut caps of the fixing bolts of the corresponding hubs, and the driving longitudinal line of the vehicle is further ensured to be perpendicular to the lens. Because the tire pressures of the front and rear wheels are different sometimes, the flat degree of the tire is different, and if the tire is contacted with the longitudinal rail only, the condition that the driving longitudinal line of the vehicle is perpendicular to the lens cannot be well guaranteed, and the technical characteristics skillfully solve the problem.

The longitudinal rail is provided with scales. After the car light on one side is well positioned, the distance between the positioning sliding block and the moving sliding block is recorded, then the moving sliding block is translated to the car light on the other side, so that the moving sliding block is the same distance with the positioning sliding block on the side, the characteristic of symmetry of the car is utilized to quickly realize positioning of the detector, and the detection efficiency is greatly improved.

Two limiting plates are fixed on the upper surface of the detector shell in parallel, ejector rods are arranged in the limiting plates, and the distance between the two limiting plates corresponds to the width of the ejector rods. The limiting plate plays a limiting role and can avoid the deviation of the ejector rod.

The lifter comprises an inner rod and an outer barrel, threaded holes are formed in the outer barrel, bolts are matched in the threaded holes, the relative positions of the inner rod and the outer barrel are fixed through the tightening of the bolts, and lifting is achieved.

The positioning sliding block is provided with a screw hole, a bolt is matched in the screw hole, and the position of the positioning sliding block is fixed by tightly extruding the transverse rail through the bolt.

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

according to the high-precision agricultural machinery headlamp detector, the two clamping and positioning devices are separated, then a vehicle is stopped between the clamping and positioning devices, the positioning sliding blocks of the two clamping and positioning devices slide towards the middle, so that the longitudinal rail of the clamping and positioning devices is in contact with the two tires on the same side, and the transverse rail rotates around the rotating shaft in order to match the contact between the longitudinal rail and the tires. When the longitudinal rails on the two sides are in contact with the front tire and the rear tire on the corresponding side at the same time, the driving longitudinal line of the vehicle is just vertical to the lens of the detector. The sliding block slides on the transverse rail, and the lifting rod is adjusted simultaneously, so that the axis of the lens of the detector coincides with the axis of the bulb, and then detection can be performed. Whether the vehicle stops or not is inclined, the longitudinal line of the vehicle can be quickly perpendicular to the lens, the detection efficiency can be improved, errors can be greatly reduced, and the detection is more accurate. The lens of the detector can be guaranteed to be right opposite to the headlamp, the longitudinal line of the vehicle is perpendicular to the lens when the vehicle is parked at one time, the vehicle does not need to be moved back and forth, the detection precision is high, the detection efficiency is high, the structure is simple, and the cost is low.

Drawings

FIG. 1 is a schematic view of an embodiment of the present invention;

FIG. 2 is a schematic cross-sectional view of the embodiment A-A shown in FIG. 1;

FIG. 3 is an enlarged view of a portion of embodiment E shown in FIG. 2;

FIG. 4 is a schematic cross-sectional view of embodiment B-B of FIG. 1;

FIG. 5 is an enlarged view of a portion of embodiment D of FIG. 1;

FIG. 6 is a schematic cross-sectional view of embodiment C-C of FIG. 1.

In the figure: 1. a rotating shaft; 2. a transverse rail; 3. a small rail; 4. a detector; 5. a bolt; 6. positioning the sliding block; 7. a limiting plate; 8. a top rod; 9. a square sleeve; 10. a longitudinal rail; 11. a small slider; 12. an inner rod; 13. an outer cylinder; 14. a cross bar; 15. erecting a rod; 16. a headlamp; 17. moving the slide block; 18. a shaft seat; 19. a sliding sleeve; 20. a horizontal axis; 21. positioning blocks; 22. a slide bar; 23. a magnetic rod; 24. a through hole; 25. a tire.

Detailed Description

In the present invention, unless otherwise specifically defined and defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be understood that the terms "central," "lateral," "longitudinal," "front," "rear," "left," "right," "upper," "lower," "vertical," "horizontal," "top," "bottom," "inner," "outer," "side," and the like are used in an orientation or positional relationship indicated in the drawings for convenience in describing the patent and for simplicity in description, and do not indicate or imply that the devices or components shown must be in a particular orientation, constructed and operated in a particular orientation, and are not to be considered limiting of the scope of the present invention.

In the present invention, unless otherwise explicitly stated or defined, the terms "mounted," "connected," "fixed," "fitted and fixed," and the like are to be understood broadly, and for example, may be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium; there may be communication between the interiors of the two elements. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

The present invention will be described more fully hereinafter with reference to the accompanying drawings of embodiments of the invention. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein, through which the invention may be more fully described; rather, these implementation examples are provided by way of example so that this disclosure will convey the scope of the invention to those skilled in the art. Further, the figures are merely schematic and not drawn to scale, and like numerals refer to like or similar elements or components throughout.

As shown in fig. 1-6, the high-precision agricultural machinery headlamp detector of the present invention includes a transverse rail 2, a rotating shaft 1 is fixed at the middle position of the lower end surface of the transverse rail 2, the rotating shaft 1 is installed in a shaft seat 18, the shaft seat 18 is fixed on the ground, the transverse rail 2 is parallel to the ground, and two ends of the transverse rail 2 are respectively provided with a set of clamping and positioning devices;

the clamping and positioning device comprises a positioning slide block 6, the positioning slide block 6 is matched on the transverse rail 2, a longitudinal rail 10 is fixed on the positioning slide block 6, and the longitudinal rail 10 is perpendicular to the transverse rail 2 and parallel to the ground;

still set up on the horizontal rail 2 and remove slider 17, remove slider 17 and be located between two clamping position device, remove the fixed lifter on the slider 17, the lifter is all perpendicular with horizontal rail 2 and ground, the fixed detector 4 in lifter upper end, the camera lens axis of detector 4 is parallel with vertical rail 10.

The working principle and the process are as follows:

during operation, the two clamping and positioning devices are separated, then the vehicle is stopped between the clamping and positioning devices, then the positioning sliding blocks 6 of the two clamping and positioning devices slide towards the middle, so that the longitudinal rail 10 of the clamping and positioning devices is in contact with the two tires 25 on the same side, and the transverse rail 2 rotates around the rotating shaft 1 in order to match the contact between the longitudinal rail 10 and the tires 25. When the longitudinal rails 10 on both sides are simultaneously contacted with the front and rear tires 25 on the corresponding sides, the driving longitudinal line of the vehicle is just vertical to the lens of the detector 4. The slider 17 is moved on the transverse rail 2 in a sliding manner, and the lifting rod is adjusted at the same time, so that the axis of the lens of the detector 4 is coincided with the axis of the bulb, and then the detection can be carried out. Whether the vehicle stops or not is inclined, the longitudinal line of the vehicle can be quickly perpendicular to the lens, the detection efficiency can be improved, errors can be greatly reduced, and the detection is more accurate.

The movable sliding block 17 is fixed with a small rail 3, the small rail 3 is perpendicular to the transverse rail 2 and parallel to the ground, the small rail 3 is matched with the small sliding block 11, and the telescopic rod is fixed on the small sliding block 11. Therefore, the detector 4 can be moved forwards and backwards conveniently, the distance between the detector 4 and the car lamp can be controlled conveniently, and the car does not need to be moved forwards and backwards.

An ejector rod 8 is hinged to the upper surface of the shell of the detector 4, the ejector rod 8 is perpendicular to the transverse rail 2, and the ejector rod 8 is parallel to the axis of the lens of the detector 4. When the multifunctional inspection instrument is used, the ejector rod 8 is rotated to the front of the inspection instrument 4, then the lifting rod is adjusted to enable the ejector rod 8 to be located above a cover of a head of the agricultural machine, then the ejector rod 8 is observed from the position right above the ejector rod 8, the sliding block 17 is moved in a translation mode, when the ejector rod 8 is aligned with a bulb, the axis of a lens of the inspection instrument 4 is parallel to the axis of the bulb, and the plane where the two axes are located is perpendicular to the transverse rail 2. The little slider of translation 11, human eye follow car light side is observed for 8 tip of ejector pin are located directly over the bulb, and the distance of bulb to the camera lens is the distance of 8 tip of ejector pin to the camera lens this moment, consequently can come the distance of quick definite camera lens to the bulb through the length of ejector pin 8, and not only the location is accurate, and the location is rapid moreover. Because 8 tip of ejector pin are close apart from the bulb distance, only keep apart the lamp shade, consequently can carry out accurate positioning fast through the range estimation, accuracy and efficiency improve greatly.

The ejector rod 8 is a square rod, the square sleeve 9 is matched on the ejector rod 8, the vertical rod 15 is fixed on the lower surface of the square sleeve 9, the cross rod 14 is vertically fixed on the vertical rod 15, the vertical rod 15 is perpendicular to the ejector rod 8, the cross rod 14 is parallel to the ejector rod 8, and the axis of the cross rod 14 coincides with the axis of a lens. Adjust the level of horizontal pole 14 through the lifter, people's eye is surveyed in the car light side, and slip square sleeve 9 makes horizontal pole 14 be close to the car light, and when the extension line of horizontal pole 14 passed through the bulb, the camera lens of detector 4 also passed through the bulb this moment, and then realized quick accurate positioning.

Two sets of accurate positioning devices are arranged on the longitudinal rail 10, each accurate positioning device comprises a sliding sleeve, a transverse shaft 20 is vertically fixed on the inner side surface of each sliding sleeve, each transverse shaft 20 is perpendicular to the longitudinal rail 10, a positioning block 21 is hinged to each transverse shaft 20 in a matched mode, a through hole 24 is formed in each positioning block 21, a sliding rod 22 is matched in each through hole 24, each sliding rod 22 is perpendicular to each transverse shaft 20, and a magnetic rod 23 is vertically fixed at the end portion of each sliding rod 22. The magnetic rods 23 can reach any position in the range swept by the sliding rods 22 through the rotation of the sliding sleeve 19 and the twitching of the sliding rods 22, the magnetic rods 23 of the two sets of precise positioning devices are fixedly attracted with the nut caps of the fixing bolts 5 corresponding to the hubs, and the driving longitudinal line of the vehicle is further ensured to be perpendicular to the lens. Because the tire pressures of the front and rear wheels are different sometimes, the flatness of the tire 25 is different, and if the tire 25 is contacted by the longitudinal rail 10 alone, the driving longitudinal line of the vehicle can not be ensured to be perpendicular to the lens, and the technical characteristics skillfully solve the problem.

The longitudinal rail 10 is provided with scales. After the car light on one side is well positioned, the distance between the positioning slide block 6 and the movable slide block 17 is recorded, then the movable slide block 17 is translated to the car light on the other side, so that the movable slide block 17 is the same as the positioning slide block 6 on the side, the characteristic of symmetry of the car is utilized to quickly realize the positioning of the detector 4, and the detection efficiency is greatly improved.

Two limiting plates 7 are fixed on the upper surface of the shell of the detector 4 in parallel, ejector rods 8 are arranged in the limiting plates 7, and the distance between the two limiting plates 7 corresponds to the width of the ejector rods 8. The limiting plate 7 has a limiting effect, and the ejector rod 8 can be prevented from deviating.

The lifter includes interior pole 12 and urceolus 13, sets up the screw hole on the urceolus 13, and screw hole fit bolt 5 is crowded tightly through bolt 5 and is fixed the relative position of interior pole 12 and urceolus 13, realizes going up and down.

The positioning sliding block 6 is provided with a screw hole, a bolt 5 is matched in the screw hole, and the position of the positioning sliding block 6 is fixed by tightly extruding the transverse rail 2 through the bolt 5.

These and other changes can be made to the present apparatus with reference to the above detailed description. While the above detailed description describes certain embodiments of the invention and describes the best mode contemplated, no matter how detailed the above appears in text, the system can be practiced in many ways. The details of the local-based support device, although considerable variation in its implementation details is possible, are nevertheless contained within the device disclosed herein. As noted above, particular technical terms used in describing particular features or aspects of the present apparatus do not imply that the terms are redefined herein to be restricted to specific characteristics, features, or aspects of the system with which the terms are associated. In general, the terms used in the following claims should not be construed to limit the system to the specific embodiments disclosed in the specification, unless the above detailed description section explicitly defines such terms. Accordingly, the actual scope of the system encompasses not only the disclosed embodiments, but also all equivalent ways of practicing or implementing the apparatus covered by the claims.

Claims

1. The utility model provides a high accuracy agricultural machinery head-light detector which characterized in that: the device comprises a transverse rail (2), wherein a rotating shaft (1) is fixed in the middle of the lower end face of the transverse rail (2), the rotating shaft (1) is installed in a shaft seat (18), the shaft seat (18) is fixed on the ground, the transverse rail (2) is parallel to the ground, and two ends of the transverse rail (2) are respectively provided with a set of clamping and positioning devices;

the clamping and positioning device comprises a positioning sliding block (6), the positioning sliding block (6) is matched on the transverse rail (2), a longitudinal rail (10) is fixed on the positioning sliding block (6), and the longitudinal rail (10) is perpendicular to the transverse rail (2) and parallel to the ground;

still set up on horizontal rail (2) and remove slider (17), remove slider (17) and be located between two clamping position device, remove fixed lifter on slider (17), lifter and horizontal rail (2) and ground are all perpendicular, and detector (4) are fixed to the lifter upper end, and the camera lens axis of detector (4) is parallel with vertical rail (10).

2. The high-precision agricultural machinery headlamp detector according to claim (1), which is characterized in that: the movable sliding block (17) is fixed with a small rail (3), the small rail (3) is perpendicular to the transverse rail (2) and parallel to the ground, the small rail (3) is matched with the small sliding block (11), and the telescopic rod is fixed on the small sliding block (11).

3. The high-precision agricultural machinery headlamp detector according to claim (1), which is characterized in that: an ejector rod (8) is hinged to the upper surface of the shell of the detector (4), the ejector rod (8) is perpendicular to the transverse rail (2), and the ejector rod (8) is parallel to the axis of the lens of the detector (4).

4. The high-precision agricultural machinery headlamp detector according to the claim (3), characterized in that: the ejector rod (8) is rotated to the front of the detector (4), then the lifting rod is adjusted to enable the ejector rod (8) to be located above a machine cover of the head of the agricultural machine, then the ejector rod (8) is observed from the position right above the ejector rod (8), the sliding block (17) is moved in a translation mode, when the ejector rod (8) is aligned with the bulb, the axis of a lens of the detector (4) is parallel to the axis of the bulb, and the plane where the two axes are located is perpendicular to the transverse rail (2); the small sliding block (11) is translated, human eyes observe from the side face of the car lamp, so that the end part of the ejector rod (8) is located right above the bulb, the distance from the bulb to the lens is the distance from the end part of the ejector rod (8) to the lens, and the distance from the lens to the bulb is rapidly determined through the length of the ejector rod (8).

5. The high-precision agricultural machinery headlamp detector according to the claim (3), characterized in that: ejector pin (8) are the square pole, cooperation square sleeve (9) on ejector pin (8), and fixed pole setting (15) in square sleeve (9) lower surface, vertical fixation horizontal pole (14) on pole setting (15), pole setting (15) and ejector pin (8) are perpendicular, and horizontal pole (14) are parallel with ejector pin (8) to horizontal pole (14) axis and camera lens axis coincidence.

6. The high-precision agricultural machinery headlamp detector according to claim (5), wherein: the horizontal height of the cross rod (14) is adjusted through the lifting rod, human eyes observe the side face of the car lamp, the cross rod (14) is close to the car lamp through the sliding square sleeve (9), and when the extension line of the cross rod (14) passes through the bulb, the axis of the lens of the detector (4) passes through the bulb.

7. The high-precision agricultural machinery headlamp detector according to claim (1), which is characterized in that: two sets of accurate positioning devices are arranged on the longitudinal rail (10), each accurate positioning device comprises a sliding sleeve (19), a transverse shaft (20) is vertically fixed on the inner side surface of the sliding sleeve (19), the transverse shaft (20) is perpendicular to the longitudinal rail (10), a positioning block (21) is hinged to the transverse shaft (20) in a matched mode, a through hole (24) is formed in the positioning block (21), a sliding rod (22) is matched in the through hole (24), the sliding rod (22) is perpendicular to the transverse shaft (20), and a magnetic rod (23) is vertically fixed at the end part of the sliding rod (22).

8. The high-precision agricultural machinery headlamp detector according to claim (7), wherein: the magnetic rods (23) of the two sets of accurate positioning devices are fixedly attracted with the nut caps of the fixing bolts (5) corresponding to the hubs, so that the driving longitudinal line of the vehicle is perpendicular to the lens.

9. The high-precision agricultural machinery headlamp detector according to claim (1), which is characterized in that: the longitudinal rail (10) is provided with scales.

10. The high-precision agricultural machinery headlamp detector according to claim (4), wherein: two limiting plates (7) are fixed on the upper surface of the shell of the detector (4) in parallel, ejector rods (8) are arranged in the limiting plates (7), and the distance between the two limiting plates (7) corresponds to the width of the ejector rods (8). The limiting plate (7) has a limiting effect, and the ejector rod (8) can be prevented from deviating.