Radar damping device based on unmanned methanol extended-range mining dump truck

Abstract

The invention relates to a radar damping device based on an unmanned methanol extended-range mining dump truck, the radar damping device comprises a fixed panel, a mounting panel, four damping sleeves and a laser radar, the four damping sleeves are uniformly distributed between the fixed panel and the mounting panel, a square hole convenient for the laser radar to pass through is formed in the middle of the mounting panel, and the laser radar is arranged in the square hole. According to the vibration reduction device, elastic deformation of an upper thin steel sheet and a lower thin steel sheet is utilized to drive a third piston to slide, transverse vibration is converted into vibration in the vertical direction, the vibration reduction effect is achieved, the vibration reduction effect is achieved, and the vibration reduction effect is achieved. Damping force is formed by friction between a valve and hydraulic oil, internal friction between hydraulic oil molecules and a first piston sliding in a damping sleeve, then all-directional damping of the laser radar is achieved, the laser radar is hidden between an installation panel and a fixed panel, and the installation panel can be used for protecting the laser radar.

Description

Technical Field

[0001] The invention belongs to the technical field of mining dump trucks, and in particular relates to a radar shock absorption device based on an unmanned methanol range-extended mining dump truck. Background Art

[0002] A mining dump truck is a heavy-duty dump truck used in open-pit mines to complete rock and earth stripping and ore transportation tasks. Its working characteristics are short travel distance and heavy load. It is usually loaded with a large electric shovel or hydraulic shovel, and travels back and forth between the mining site and the unloading site. Due to the complex working environment of mining dump trucks, high driving skills are required of the driver. In addition, the ore and earth are prone to landslides during the stripping process. Compared with manned driving, unmanned mining dump trucks do not require a driver to drive, so even if a landslide occurs, it is not easy to cause casualties, and they are safer. With the gradual maturity of unmanned driving technology, unmanned mining dump trucks have greater development space than manned mining dump trucks.

[0003] In order to increase the mileage of unmanned mining dump trucks, reduce fuel consumption and minimize the impact on the environment, unmanned mining dump trucks are generally modified to use methanol as fuel to extend the range. In addition, in order to facilitate unmanned driving, a large number of laser radars need to be installed on mining dump trucks to explore road conditions and work areas. The laser radar system is a precision optical mechanical system and is very sensitive to vibration. Braking, turning, and shock absorption during the driving of the dump truck will cause vibration, impact and other mechanical effects on the laser radar on the vehicle. If the on-board shock absorption of the laser radar is unqualified, the equipment structure will be deformed, and the optical system will detect an offset, resulting in incorrect or unmeasured measurements. Therefore, it is essential to equip the laser radar with appropriate shock absorption devices. Summary of the invention

[0004] In view of this, the object of the present invention is to provide a radar shock absorption device based on an unmanned methanol range-extended mining dump truck to solve the above-mentioned problems.

[0005] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is: the radar shock absorption device comprises a fixed panel, a mounting panel, a shock absorption sleeve and a laser radar, the fixed panel is fixed on the body of the unmanned methanol extended-range mining dump truck by bolts, four shock absorption sleeves are evenly distributed between the fixed panel and the mounting panel, the shock absorption sleeve is filled with hydraulic oil, two first pistons are slidably connected in the shock absorption sleeve, the first piston and the end cavity of the shock absorption sleeve are side cavities, the cavity between the two first pistons is a hollow cavity, and mounting seats are arranged at the upper and lower ends of the shock absorption sleeve, and the mounting seats A connecting rod is arranged between the first piston, one end of the connecting rod is fixedly connected to the first piston, the connecting rod passes through the end of the shock-absorbing sleeve, and the other end of the connecting rod is fixedly connected to the mounting seat, a shock-absorbing spring is sleeved on the connecting rod, one end of the shock-absorbing spring is fixedly connected to the end of the shock-absorbing sleeve, and the other end of the shock-absorbing spring is fixedly connected to the mounting seat, an oil storage sleeve is arranged between adjacent shock-absorbing sleeves, the left and right ends of the oil storage sleeve are respectively connected to the middle part of the shock-absorbing sleeve at the corresponding end, two partitions are arranged in the oil storage sleeve, two second pistons are slidably connected in the cavity between the two partitions, and the cavity between the two pistons is filled with compressed air.

[0006] A square hole is provided in the middle of the mounting plate for the laser radar to pass through, and a mounting straight plate is fixed to the four lower edges of the square hole of the mounting plate, a positioning seat with an open lower end and a sealed upper end is provided in the square hole of the mounting plate, the upper end of the positioning seat is fixedly connected to the laser radar, the lower edge of the positioning seat is turned outward, and a spring group is provided between the four lower edges of the positioning seat and the corresponding side mounting straight plate, the spring group includes an upper thin steel sheet, a lower thin steel sheet and two steel plates, the upper thin steel sheet is fixedly connected to the mounting straight plate by rivets, and the lower thin steel sheet is connected by rivets. It is fixedly connected to the lower edge of the positioning seat through rivets, steel plates are arranged on both sides of the upper thin steel sheet and the lower thin steel sheet, the steel plates on both sides of the upper thin steel sheet and the lower thin steel sheet are fixedly connected by bolts, and the upper thin steel sheet and the lower thin steel sheet are clamped and connected as a whole by two steel plates, a cylinder is arranged between the spring group and the oil storage sleeve, the bottom end of the cylinder is connected to the cavity between the two second pistons of the oil storage sleeve, a third piston is slidably connected in the cylinder, a conduction push rod is fixed on the third piston, the conduction push rod passes through the top end of the cylinder, and the conduction push rod is fixedly connected to the steel plate.

[0007] The first piston is provided with an extension valve and a flow valve. When the first piston is in an extension stroke, the hydraulic oil in the side cavity of the shock-absorbing sleeve flows unidirectionally to the hollow cavity of the shock-absorbing sleeve through the extension valve. When the first piston is in a compression stroke, the hydraulic oil in the hollow cavity of the shock-absorbing sleeve flows unidirectionally to the side cavity of the shock-absorbing sleeve through the flow valve.

[0008] A compression valve and a compensation valve are arranged on the partition. When the first piston is in an extension stroke, the hydraulic oil between the partition and the second piston enters the cavity of the shock-absorbing sleeve in one direction through the compensation valve. When the first piston is in a compression stroke, the hydraulic oil in the cavity of the shock-absorbing sleeve enters the cavity between the partition and the second piston in one direction through the compression valve.

[0009] Preferably, the upper end surface of the positioning seat and the upper side surface of the installation panel are in the same plane or the upper end surface of the positioning seat is located below the installation panel.

[0010] Preferably, a buffer spring is provided in the oil storage sleeve, the buffer spring is located between the two second pistons, and both ends of the buffer spring are fixedly connected to the second pistons on both sides respectively, and the buffer spring is used for buffering.

[0011] The beneficial effects of the present invention are as follows: the present invention is based on the friction between the compression valve, the compensation valve, the extension valve, the circulation valve and the hydraulic oil, the internal friction between the hydraulic oil molecules and the first piston sliding in the shock-absorbing sleeve to form a damping force, so as to convert the vibration energy into the hydraulic oil heat energy, which is then dissipated into the atmosphere through the shock-absorbing sleeve shell. When the vertical shock absorption is completed, the upper thin steel sheet and the lower thin steel sheet are elastically deformed, and the third piston is driven to slide through the steel plate and the conductive push rod, so as to adjust the pressure of the compressed air between the two second pistons in the oil storage sleeve, and then push the second piston to slide, change the hydraulic oil pressure in the shock-absorbing sleeve, convert the lateral vibration into the vertical vibration, and utilize the friction between the compression valve, the compensation valve, the extension valve, the circulation valve and the hydraulic oil, the internal friction between the hydraulic oil molecules and the first piston sliding in the shock-absorbing sleeve to form a damping force, so as to complete the shock absorption around the horizontal laser radar, and then realize the all-round shock absorption of the laser radar. In addition Based on the working parts of different types of laser radars, without affecting the work of the laser radar, by lowering the height of the positioning seat and setting the upper end surface of the positioning seat under the installation panel, the laser radar can be hidden between the installation panel and the fixed panel, and the installation panel can be used to protect the laser radar to prevent accidental external impact from directly damaging the laser radar; when the horizontal vibration and the vertical vibration form mutual damping, the horizontal vibration and the vertical vibration offset each other, that is, the horizontal vibration is converted into the vertical vibration and the actual vertical vibration offsets each other, compared with a single shock absorbing device, the shock absorption effect is improved; when the vertical vibration converted from the horizontal vibration resonates with the actual vertical vibration, compared with a single shock absorbing device, although the shock absorption effect is affected to a certain extent, due to the complex and changeable external environment, the resonance duration is much shorter than the non-resonance duration, and the all-round shock absorption effect can still be maintained. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a front view of the radar shock absorbing device of the present invention;

[0013] Figure 2 This is a structural diagram of the shock-absorbing sleeve in the present invention;

[0014] Figure 3 This is a structural diagram of the oil storage sleeve in the present invention;

[0015] Figure 4 It is a front view of the radar shock absorbing device of the present invention;

[0016] Figure 5 The radar shock absorption device structure of the present invention Figure 1 ;

[0017] Figure 6 The radar shock absorption device structure of the present invention Figure 2 .

[0018] Numbers in the figure: 1 fixed panel; 2 mounting panel; 3 shock-absorbing sleeve; 4 laser radar; 5 first piston; 6 mounting seat; 7 connecting rod; 8 shock-absorbing spring; 9 oil storage sleeve; 901 partition; 10 second piston; 11 mounting straight plate; 12 positioning seat; 13 spring group; 14 upper thin steel sheet; 15 lower thin steel sheet; 16 steel plate; 17 cylinder; 18 third piston; 19 conduction push rod; 20 buffer spring. DETAILED DESCRIPTION

[0019] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments:

[0020] like Figure 1-3 As shown, the radar shock absorption device described in this embodiment includes a fixed panel 1, a mounting panel 2, a shock absorption sleeve 3 and a laser radar 4. The fixed panel 1 is fixed on the body of the unmanned methanol range-extended mining dump truck by bolts. Four shock absorption sleeves 3 are evenly distributed between the fixed panel 1 and the mounting panel 2, and the laser radar 4 is fixedly installed in the middle of the upper side of the mounting panel 2. The shock absorption sleeve 3 is filled with hydraulic oil. Two first pistons 5 are slidably connected in the shock absorption sleeve 3. The cavities at the ends of the first piston 5 and the shock absorption sleeve 3 are side cavities, and the cavity between the two first pistons 5 is a hollow cavity. The upper and lower ends of the shock absorption sleeve 3 are provided with mounting seats 6, and the mounting seat 6 is connected to the first A connecting rod 7 is arranged between the pistons 5, one end of the connecting rod 7 is fixedly connected to the first piston 5, the connecting rod 7 passes through the end of the shock-absorbing sleeve 3, and the other end of the connecting rod 7 is fixedly connected to the mounting seat 6, a shock-absorbing spring 8 is sleeved on the connecting rod 7, one end of the shock-absorbing spring 8 is fixedly connected to the end of the shock-absorbing sleeve 3, and the other end of the shock-absorbing spring 8 is fixedly connected to the mounting seat 6, an oil storage sleeve 9 is arranged between adjacent shock-absorbing sleeves 3, the left and right ends of the oil storage sleeve 9 are respectively connected to the middle part of the corresponding shock-absorbing sleeve 3, two partitions 901 are arranged in the oil storage sleeve 9, two second pistons 10 are slidably connected in the cavity between the two partitions 901, and the cavity between the two pistons 10 is filled with compressed air.

[0021] In this embodiment, an extension valve and a flow valve are provided on the first piston 5. When the first piston 5 is in an extension stroke, the hydraulic oil in the side cavity of the shock-absorbing sleeve 3 flows unidirectionally to the hollow cavity of the shock-absorbing sleeve 3 through the extension valve. When the first piston 5 is in a compression stroke, the hydraulic oil in the hollow cavity of the shock-absorbing sleeve 3 flows unidirectionally to the side cavity of the shock-absorbing sleeve 3 through the flow valve.

[0022] In this embodiment, a compression valve and a compensation valve are provided on the partition 901. When the first piston 5 is in the extension stroke, the hydraulic oil between the partition 901 and the second piston 10 enters the cavity of the shock-absorbing sleeve 3 in one direction through the compensation valve. When the first piston 5 is in the compression stroke, the hydraulic oil in the cavity of the shock-absorbing sleeve 3 enters the cavity between the partition 901 and the second piston 10 in one direction through the compression valve.

[0023] In this embodiment, a buffer spring 20 is provided in the oil storage sleeve 9. The buffer spring 20 is located between the two second pistons 10, and both ends of the buffer spring 20 are fixedly connected to the second pistons 10 on both sides, respectively, and the buffer spring 20 is used for buffering.

[0024] In this embodiment, when the radar shock absorption device is working, when vibration occurs during the operation of the unmanned methanol extended-range mining dump truck, the first piston 5 undergoes an extension stroke and a compression stroke based on the frequency of the vibration. When the first piston 5 is in the extension stroke, since the connecting rod 7 occupies the side cavity space, the rate at which the side cavity space of the shock-absorbing sleeve 5 decreases is less than the rate at which the cavity space in the shock-absorbing sleeve 5 increases. Under the pressure of the compressed air between the two second pistons 10 and the elastic force of the buffer spring 20, the second piston 10 approaches the partition 901, and the hydraulic oil between the second piston 10 and the partition 901 is pressed into the cavity of the shock-absorbing sleeve 3 through the compensation valve. The hydraulic oil in the side cavity of the shock-absorbing sleeve 5 flows into the hollow cavity of the shock-absorbing sleeve 5 through the extension valve. When the first piston 5 is in the extension stroke, since the connecting rod 7 occupies the side cavity space, the rate at which the side cavity space of the shock-absorbing sleeve 5 decreases is less than the rate at which the cavity space in the shock-absorbing sleeve 5 increases. When a piston 5 is in a compression stroke, since the connecting rod 7 occupies the side cavity space, the rate at which the side cavity space of the shock-absorbing sleeve 5 increases is lower than the rate at which the cavity space in the shock-absorbing sleeve 5 decreases. Under the action of the hydraulic oil pressure in the cavity of the shock-absorbing sleeve 5, the hydraulic oil in the cavity of the shock-absorbing sleeve 5 flows to the side cavity of the shock-absorbing sleeve 5 through the circulation valve. At the same time, the excess hydraulic oil in the cavity of the shock-absorbing sleeve 5 enters the cavity between the partition 901 and the second piston 10 through the compression valve. The friction between the compression valve, the compensation valve, the extension valve, the circulation valve and the hydraulic oil and the internal friction between the hydraulic oil molecules form a damping force with the first piston 5 sliding in the shock-absorbing sleeve 3, converting the vibration energy into hydraulic oil heat energy, which is then dissipated into the atmosphere through the shell of the shock-absorbing sleeve 3, and finally completing the vertical shock absorption.

[0025] like Figure 4-6As shown, a square hole is provided in the middle of the mounting plate 2 for the laser radar 4 to pass through, and the four lower edges of the square hole of the mounting plate 2 are fixed with mounting straight plates 11, and a positioning seat 12 with an open lower end and a sealed upper end is provided in the square hole of the mounting plate 2, the upper end of the positioning seat 12 is fixedly connected to the laser radar 4, the lower edge of the positioning seat 12 is turned outward, and a spring group 13 is provided between the four lower edges of the positioning seat 12 and the corresponding side mounting straight plates 11, respectively, and the spring group 13 includes an upper thin steel sheet 14, a lower thin steel sheet 15 and two steel plates 16, the upper thin steel sheet 14 is fixedly connected to the mounting straight plate 11 by rivets, and the lower thin steel sheet 15 is fixedly connected to the fixed plate 11 by rivets. The lower edge of the seat 12 is fixedly connected, and steel plates 16 are arranged on both sides of the upper thin steel sheet 14 and the lower thin steel sheet 15. The steel plates 16 on both sides of the upper thin steel sheet 14 and the lower thin steel sheet 15 are fixedly connected by bolts, and the upper thin steel sheet 14 and the lower thin steel sheet 15 are clamped and connected as a whole by the two steel plates 16. A cylinder 17 is arranged between the spring group 13 and the oil storage sleeve 9, and the bottom end of the cylinder 17 is communicated with the cavity between the two second pistons 10 of the oil storage sleeve 9. A third piston 18 is slidably connected in the cylinder 17, and a conduction push rod 19 is fixed on the third piston 18. The conduction push rod 19 passes through the top of the cylinder 17, and the conduction push rod 19 is fixedly connected to the steel plate 16.

[0026] In this embodiment, the upper end surface of the positioning seat 12 and the upper side surface of the installation panel 2 are in the same plane or the upper end surface of the positioning seat 12 is located below the installation panel 12 .

[0027] In this embodiment, when the vertical damping is completed by the cooperation of the damping sleeve 3, the first piston 5, the connecting rod 7 and the damping spring 8, when the lateral vibration occurs, the upper thin steel sheet 14 and the lower thin steel sheet 15 are elastically deformed, and the third piston 18 is driven to slide through the steel plate 16 and the conductive push rod 19, and the pressure of the compressed air between the two second pistons 10 in the oil storage sleeve 9 is adjusted, and then the second piston 10 is pushed to slide, and the hydraulic oil pressure in the damping sleeve 3 is changed, and the first piston 5 is driven to perform a compression or extension stroke, and the lateral vibration is converted into a vertical vibration, and the compression valve, the compensation valve, and the extension valve are used. The friction between the valve, the circulation valve and the hydraulic oil, and the internal friction between the hydraulic oil molecules form a damping force with the first piston 5 sliding in the shock-absorbing sleeve 3, completing the shock absorption of horizontal vibration, thereby realizing all-round shock absorption. In addition, based on the working parts of different types of laser radars 4, without affecting the work of the laser radar 4, by lowering the height of the positioning seat 12 and setting the upper end surface of the positioning seat 12 under the mounting panel 12, the laser radar 4 can be hidden between the mounting panel 2 and the fixed panel 1, and the mounting panel 2 can be used to protect the laser radar 4 to prevent accidental external impacts from directly damaging the laser radar 4.

[0028] When the vibration in the vertical direction causes the first piston 5 to be in a compression stroke, and the horizontal vibration causes the third piston 18 to compress the compressed air between the two second pistons 10, the horizontal vibration and the vertical vibration form mutual damping, and the horizontal vibration and the vertical vibration cancel each other out. Compared with a single shock absorbing device, the shock absorbing effect is improved. Similarly, when the vibration in the vertical direction causes the first piston 5 to be in an extension stroke, and the horizontal vibration causes the third piston 18 to compress the air between the two second pistons 10 to expand, the horizontal vibration and the vertical vibration form mutual damping, and the horizontal vibration and the vertical vibration cancel each other out. That is, when the horizontal vibration is converted into the vertical vibration and the actual vertical vibration cancels each other out, the shock absorbing effect is improved compared with a single shock absorbing device.

[0029] When the vibration in the vertical direction causes the first piston 5 to be in a compression stroke, and the vibration in the horizontal direction causes the third piston 18 to compress the air between the two second pistons 10 to expand, the damping force of the second piston 10 on the hydraulic oil is reduced due to the reduced pressure of the compressed air expansion. Compared with a single shock absorbing device, the shock absorbing effect is reduced, but all-round shock absorption can be performed. Similarly, when the vibration in the vertical direction causes the first piston 5 to be in an extension stroke, and the vibration in the horizontal direction causes the third piston 18 to compress the air between the two second pistons 10, the pressure of the compressed air is increased, and the hydraulic oil pressure between the second piston 10 and the partition 901 is reduced, that is, when the vibration in the horizontal direction is converted into the vibration in the vertical direction and resonates with the actual vibration in the vertical direction, compared with a single shock absorbing device, the generation of resonance requires that the frequency of the vibration in the horizontal direction converted into the vibration in the vertical direction is completely equal to the actual vibration frequency in the vertical direction. The external environment will affect the generation of vibration and the change of vibration frequency. The road conditions used by the unmanned methanol range-extended mining dump truck are complex, and the resonance duration is much shorter than the non-resonance duration, so the all-round shock absorption effect can still be maintained.

[0030] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A radar shock absorption device based on an unmanned methanol range-extended mining dump truck, the radar shock absorption device comprising a fixed panel, a mounting panel, a shock absorption sleeve and a laser radar, the fixed panel is fixed on the body of the unmanned methanol range-extended mining dump truck by bolts, four shock absorption sleeves are evenly distributed between the fixed panel and the mounting panel, and the characteristics are: The shock-absorbing sleeve is filled with hydraulic oil, and two first pistons are slidably connected in the shock-absorbing sleeve, the cavity between the first piston and the end of the shock-absorbing sleeve is a side cavity, and the cavity between the two first pistons is a hollow cavity, and mounting seats are provided at the upper and lower ends of the shock-absorbing sleeve, and a connecting rod is provided between the mounting seat and the first piston, one end of the connecting rod is fixedly connected to the first piston, the connecting rod passes through the end of the shock-absorbing sleeve, and the other end of the connecting rod is fixedly connected to the mounting seat, a shock-absorbing spring is sleeved on the connecting rod, one end of the shock-absorbing spring is fixedly connected to the end of the shock-absorbing sleeve, and the other end of the shock-absorbing spring is fixedly connected to the mounting seat, an oil storage sleeve is provided between adjacent shock-absorbing sleeves, the left and right ends of the oil storage sleeve are respectively connected to the middle part of the corresponding shock-absorbing sleeve at one end, two partitions are provided in the oil storage sleeve, two second pistons are slidably connected in the cavity between the two partitions, and the cavity between the two pistons is filled with compressed air.

2. The radar shock absorption device based on an unmanned methanol range-extended mining dump truck according to claim 1 is characterized in that: A square hole is provided in the middle of the mounting plate for the laser radar to pass through, and a mounting straight plate is fixed to the four lower edges of the square hole of the mounting plate, a positioning seat with an open lower end and a sealed upper end is provided in the square hole of the mounting plate, the upper end of the positioning seat is fixedly connected to the laser radar, the lower edge of the positioning seat is turned outward, and a spring group is provided between the four lower edges of the positioning seat and the corresponding side mounting straight plate, the spring group includes an upper thin steel sheet, a lower thin steel sheet and two steel plates, the upper thin steel sheet is fixedly connected to the mounting straight plate by rivets, and the lower thin steel sheet is connected by rivets. It is fixedly connected to the lower edge of the positioning seat through rivets, steel plates are arranged on both sides of the upper thin steel sheet and the lower thin steel sheet, the steel plates on both sides of the upper thin steel sheet and the lower thin steel sheet are fixedly connected by bolts, and the upper thin steel sheet and the lower thin steel sheet are clamped and connected as a whole by two steel plates, a cylinder is arranged between the spring group and the oil storage sleeve, the bottom end of the cylinder is connected to the cavity between the two second pistons of the oil storage sleeve, a third piston is slidably connected in the cylinder, a conduction push rod is fixed on the third piston, the conduction push rod passes through the top end of the cylinder, and the conduction push rod is fixedly connected to the steel plate.

3. The radar shock absorption device based on an unmanned methanol range-extended mining dump truck according to claim 1 is characterized in that: The first piston is provided with an extension valve and a flow valve. When the first piston is in an extension stroke, the hydraulic oil in the side cavity of the shock-absorbing sleeve flows unidirectionally to the hollow cavity of the shock-absorbing sleeve through the extension valve. When the first piston is in a compression stroke, the hydraulic oil in the hollow cavity of the shock-absorbing sleeve flows unidirectionally to the side cavity of the shock-absorbing sleeve through the flow valve.

4. The radar shock absorption device based on an unmanned methanol range-extended mining dump truck according to claim 1 is characterized in that: A compression valve and a compensation valve are arranged on the partition. When the first piston is in an extension stroke, the hydraulic oil between the partition and the second piston enters the cavity of the shock-absorbing sleeve in one direction through the compensation valve. When the first piston is in a compression stroke, the hydraulic oil in the cavity of the shock-absorbing sleeve enters the cavity between the partition and the second piston in one direction through the compression valve.

5. The radar shock absorption device based on an unmanned methanol range-extended mining dump truck according to claim 1 is characterized in that: A buffer spring is arranged in the oil storage sleeve, the buffer spring is located between the two second pistons, and both ends of the buffer spring are respectively fixedly connected to the second pistons on both sides, and the buffer spring is used for buffering.

6. The radar shock absorption device based on an unmanned methanol range-extended mining dump truck according to claim 2 is characterized in that: The upper end surface of the positioning seat and the upper side surface of the installation panel are in the same plane or the upper end surface of the positioning seat is located below the installation panel.

Images