CN213025420U

CN213025420U - Radioactive solid waste collecting and transferring device

Info

Publication number: CN213025420U
Application number: CN202020451420.2U
Authority: CN
Inventors: 李杨; 黄勇; 曾松柏; 雷嗣烦; 陈林
Original assignee: Chengdu Gaotong Isotope Co ltd Cnnc
Current assignee: Chengdu Gaotong Isotope Co ltd Cnnc
Priority date: 2020-03-31
Filing date: 2020-03-31
Publication date: 2021-04-20
Anticipated expiration: 2030-03-31

Abstract

The utility model relates to a radioactive waste treatment device's field particularly, relates to a radioactive solid useless collection transfer device, cooperates and uses in the shielded cell. And a waste material port is arranged at the bottom of the shielding box. The radioactive solid waste collecting and transferring device comprises a transfer trolley provided with a lifting platform and a transfer tank. The transfer tank is matched with the lifting platform to be arranged, so that the transfer tank can be placed on the lifting platform. The feed inlet has been seted up to the cooperation waste material mouth in transit tank top to make the feed inlet can communicate the waste material mouth. When the transfer tank is used, the transfer tank is placed on the lifting platform, and the transfer trolley is pushed to the position right below the shielding box. The elevating platform rises to enable the feed inlet to be gradually close to the waste material opening and to be in butt joint with the waste material opening. The shielding box is communicated with the transfer tank and has no gap, so that aerosol in the shielding box is prevented from leaking through the gap. When the waste materials need to be transported, the lifting platform descends, so that the shielding box is separated from the transport tank. The cover with good shielding property is used for covering the feed inlet of the transfer tank, so that the transfer trolley can be pushed to transfer waste materials, and the use is convenient.

Description

Radioactive solid waste collecting and transferring device

Technical Field

The utility model relates to a radioactive waste treatment device's field particularly, relates to a radioactive solid useless collection transfer device.

Background

Radioisotopes are currently used in many fields, especially in nuclear medicine. Many radioactive isotope medicines have incomparable advantages in the aspects of diagnosis and treatment of certain diseases by common medicines, so that the radioactive isotope medicines become preferred methods at home and abroad, and the economic benefit and the social effect are significant.

As the demand for radiopharmaceuticals increases year by year, more and more radioactive waste is generated during the production of the pharmaceuticals. Because of the particularity of radiopharmaceuticals, both production and research must be performed in shielded glove boxes or hot rooms, i.e., shielded cabinets, and there are two temporary ways to dispose of radioactive solid waste generated during the production and research processes:

one is for the case of low waste production and low overall radioactivity. A special collecting container is generally placed in a shielding box, and radioactive solid wastes generated in the production process are directly thrown into the container for collection and temporary storage.

Alternatively, the case of greater waste production or greater overall radioactivity is addressed. A special waste channel is generally designed at the bottom of the shielding box, a collection container is arranged below the waste channel, a lead shielding layer is used for surrounding the container, and radioactive solid wastes are thrown into the collection container through a waste channel.

After every period of time or the container is full, the shielding box door or the lead shielding layer is opened, the collection container is taken out to be sealed, then the collection container is transferred into a lead shielding barrel, transferred to a temporary waste storage room through manual work or a transfer trolley to be temporarily stored, and then a new collection container is replaced.

For the first approach, the main disadvantages are: firstly, the collecting container occupies the available space in the shielding box; secondly, the door of the shielding box needs to be opened in the transfer process of the collecting container, and a radioactive dose field in the shielding box is not too low usually, so that the irradiated dose of operators can be increased to a certain extent; in the process of transferring the collecting container to the lead shielding barrel, although the time is short, operators still can be irradiated by large dose because the shielding strength of the container is not enough; the shielding box usually has small space, so the volume of the container is small, and the amount capable of being collected at one time is very limited.

For the second approach, there are several major disadvantages: firstly, the lead shielding layer of the collecting container needs to be opened during each transfer, and needs to be reset after the container is replaced, so that the operation is very inconvenient; the collection container cannot be in seamless butt joint with the shielding box, so that radioactive aerosol in the glove box can be leaked to the external environment, and personnel irradiation and environmental pollution are caused; like the first mode, the operator is exposed to a large dose of radiation during the transfer of the collection container to the lead shielding drum.

In addition, in the above two ways, there are several disadvantages in transferring the full collection container to the waste buffer: firstly, because the shielding barrels of the collecting containers are usually very heavy, the manual transportation needs at least 2 persons, even if a transportation trolley is adopted, the shielding barrels need to be manually placed on the trolley, and the labor intensity of the personnel is high; secondly, different shielding barrels may need to be configured for collecting containers with different sizes, and a uniform large-size shielding barrel is used, so that the universality is not high.

SUMMERY OF THE UTILITY MODEL

The utility model aims to provide a radioactive solid waste collecting and transferring device, which can lead a transferring tank to be communicated below a shielding box, thereby facilitating the feeding; meanwhile, the transportation is convenient.

The embodiment of the utility model is realized like this:

a radioactive solid waste collecting and transferring device is matched with a shielding box for use; the bottom of the shielding box is provided with a waste material port; the radioactive solid waste collecting and transferring device comprises a transfer trolley and a transfer tank; the transfer trolley is provided with a lifting platform;

the transfer tank is matched with the lifting platform to be arranged, so that the transfer tank can be placed on the lifting platform; the cooperation of transport tank top the feed inlet has been seted up to the waste material mouth, so that the feed inlet can communicate the waste material mouth.

Furthermore, the lifting platform comprises a lifting platform, a screw pair and a hand wheel; the hand wheel is connected with the lead screw pair in a transmission way; the lifting table is matched with the lead screw pair, so that the lead screw pair can drive the lifting table to lift;

further, the transfer trolley comprises a bottom plate and a handle connected to the bottom plate; the screw rod pair comprises a screw rod and a nut; the screw rod is vertically arranged on the bottom plate in a rotatable manner; a first bevel gear is arranged at the top end of the screw rod; the hand wheel is connected with a transmission rod; one end of the transmission rod is provided with a second bevel gear in a matching way with the first bevel gear so that the transmission rod can drive the screw rod to rotate;

the lifting platform is connected to the nut, so that the lifting platform can lift along with the nut.

Furthermore, the lifting platform is provided with a plurality of guide rods; the guide rods are vertically arranged on the bottom plate.

Furthermore, the lifting platform is provided with 4 guide rods; the 4 guide rods are respectively positioned at four corners of the lifting platform.

Further, the transfer tank is also provided with a sealing cover.

Further, a sealing ring is arranged between the transfer tank and the shielding box.

Furthermore, a positioning pit is arranged below the shielding box and matched with a wheel of the transfer trolley, so that when the wheel enters the positioning pit, the feeding hole is positioned right below the waste material hole.

Furthermore, the lifting platform comprises a lifting platform, a first lifting rod, a second lifting rod, a screw pair and a hand wheel; the transfer trolley comprises a bottom plate and a handle connected to the bottom plate; the screw rod pair comprises a screw rod and a nut;

the first lifting rod and the second lifting rod are arranged in a crossed mode, and the first lifting rod is hinged to the second lifting rod; one end of the first lifting rod is hinged to the bottom plate, and the other end of the first lifting rod is slidably arranged at the bottom of the lifting platform; one end of the second lifting rod is hinged to the bottom of the lifting platform, and the other end of the second lifting rod is hinged to the nut;

the bottom plate is provided with a sliding groove matched with the nut, so that the nut can slide in the sliding groove; one end of the screw is connected with the hand wheel, so that the hand wheel rotates to enable the nut to slide along the sliding groove.

The utility model has the advantages that:

during the use, will transport the jar and place the elevating platform and promote the transfer car (buggy) under the shielded cell for the feed inlet of transporting the jar is located the waste material mouth of shielded cell under. Then, the hand wheel is shifted, so that the screw rod rotates, and the lifting platform is driven to ascend along with the nut. And in the ascending process of the lifting platform, the feed inlet is gradually close to the waste material opening, and the feed inlet is butted with the waste material opening. This allows the shielding box to communicate with the transfer tank without a gap therebetween. Effectively avoid the aerosol in the shielded cell to pass through the clearance leakage between shielded cell and the transport jar. In the production process, an operator can directly deliver the generated waste into the transfer tank through the waste port.

When the waste materials need to be transported, the hand wheel is stirred to enable the lifting platform to descend, and then the shielding box is separated from the transport tank. After the shielding box is separated from the transfer tank, the feed inlet of the transfer tank is covered by a cover with good shielding property. The waste material can then be transported by pushing the transfer trolley.

The radioactive solid waste collecting and transferring device can be communicated with the shielding box, so that waste is conveniently and directly delivered to the transferring tank, and space waste caused by temporary storage of the waste in the shielding box is avoided; while still avoiding aerosol leakage within the shielded enclosure. The waste material is directly delivered to the transfer tank, so that the waste material does not need to be taken out or sealed and packed when being transferred, the process is simplified, and meanwhile aerosol leakage is avoided. The cooperation of the transfer tank and the transfer trolley greatly facilitates the transfer of the waste materials. In addition, the transfer tank can be replaced at will, and the use is convenient.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are required to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention, and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

Fig. 1 is a schematic view of a radioactive solid waste collecting and transferring device provided by an embodiment of the present invention cooperating with a shielding box;

FIG. 2 is a schematic view of the transfer vehicle and transfer pot in accordance with an embodiment of the present invention;

FIG. 3 is a schematic view of a transfer tank according to an embodiment of the present invention;

fig. 4 is a schematic structural view of a transfer trolley provided in embodiment 2 of the present invention.

Icon:

1-a shielding box, 11-a waste material port, 2-a transfer vehicle, 21-a bottom plate, 22-a handle, 23-a first support frame, 24-a second support frame, 25-a third support frame, 3-a lifting platform, 31-a lifting platform, 32-a hand wheel, 33-a screw rod, 34-a nut, 35-a transmission rod, 36-a first bevel gear, 37-a second bevel gear, 38-a guide rod, 39-a first lifting rod, 391-a second lifting rod, 4-a transfer tank, 41-a feed port, 42-a sealing cover, 43-a sealing ring, 44-a positioning pit, 45-a stainless steel barrel and 46-a butt lead cover.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. The components of embodiments of the present invention, as generally described and illustrated in the figures herein, may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the present invention, presented in the accompanying drawings, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate the position or positional relationship based on the position or positional relationship shown in the drawings, or the position or positional relationship which is usually placed when the product of the present invention is used, and are only for convenience of description and simplification of the description, but do not indicate or imply that the device or element referred to must have a specific position, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention.

The terms "first," "second," "third," and the like are used solely to distinguish one from another and are not to be construed as indicating or implying relative importance.

The terms "parallel", "perpendicular", etc. do not require that the components be absolutely parallel or perpendicular, but may be slightly inclined. For example, "parallel" merely means that the directions are more parallel relative to "perpendicular," and does not mean that the structures are necessarily perfectly parallel, but may be slightly tilted.

The terms "horizontal", "vertical", "overhang" and the like do not imply that the components are required to be absolutely horizontal, vertical or overhang, but may be slightly inclined. For example, "horizontal" merely means that the direction is more horizontal than "vertical" and does not mean that the structure must be perfectly horizontal, but may be slightly inclined.

Example 1:

referring to fig. 1 to 3, the present embodiment provides a radioactive solid waste collecting and transferring device, which is used in cooperation with a shielding box 1. The shielded box 1 is a shielded glove box or a hot chamber. The bottom of the shielding box 1 is provided with a waste port 11. During the use, operating personnel stretches into gloves and then operates inside shielding glove box with the hand. Nuclear waste generated during the production process is thrown into the waste port 11 and discharged out of the shielded glove box.

The radioactive solid waste collecting and transferring device comprises a transfer trolley 2 and a transfer tank 4. The trolley 2 comprises a floor 21 and a handle 22 attached to one end of the floor 21. A plurality of rollers are arranged below the bottom plate 21. Generally, the rollers are provided with 4 rollers, and the 4 rollers can be locked, so that the transfer trolley 2 is prevented from sliding randomly. The two rollers near one end of the handle 22 are universal wheels, which facilitates the operator to move the transfer vehicle 2. The trolley 2 is also provided with a first support 23, a second support 24 and a third support 25. The first supporting frame 23 is positioned at the front end of the bottom plate 21; the second supporting frame 24 is positioned at the rear end of the bottom plate 21; the third support bracket 25 is connected to the handle 22 and extends horizontally towards the interior of the trolley 2.

The transfer trolley 2 is provided with a lifting platform 3. The front end descending platform positioned on the bottom plate 21 comprises a lifting platform 31, a screw pair and a hand wheel 32. The screw pair includes a screw 33 and a nut 34. The screw 33 is vertically arranged on the bottom plate 21 through a bearing; meanwhile, the upper end of the screw 33 is connected to the second support frame 24 through a bearing. The top end of the screw 33 is provided with a first bevel gear 36. The hand wheel 32 is connected with a transmission rod 35. The transmission rod 35 is horizontally disposed and connected to the third support frame 25 through a bearing. One end of the transmission rod 35 is provided with a second bevel gear 37 in cooperation with the first bevel gear 36, so that the transmission rod 35 can drive the screw 33 to rotate. The hand wheel 32 is positioned outside the handle 22, which is convenient for an operator to stir the hand wheel 32. The nut 34 is attached to the elevating table 31. When the hand wheel 32 drives the screw 33 to rotate, the lifting platform 31 is lifted along with the nut 34.

The transfer pot 4 is provided in cooperation with the elevating platform 31 so that the transfer pot 4 can be placed on the elevating platform 31. The transfer tank 4 is a lead tank with good shielding performance. The top of the transfer tank 4 is matched with the waste port 11 and is provided with a feed inlet 41. When the top of the transfer tank 4 abuts against the bottom of the shielding box 1, the feed port 41 is communicated with the waste port 11. The feed port 41 of the transfer tank 4 is further provided with a lead seal cover 42.

When the transfer tank is used, the transfer tank 4 is placed on the lifting platform 31, and the transfer trolley 2 is pushed to the position right below the shielding box 1, so that the feeding port 41 of the transfer tank 4 is positioned right below the waste port 11 of the shielding box 1. Subsequently, the hand wheel 32 is toggled, so that the screw 33 is rotated, and the lifting platform 31 is driven to ascend along with the nut 34. During the ascending of the elevating platform 31, the feeding port 41 is gradually close to the waste port 11 and the feeding port 41 is butted against the waste port 11. This allows the shield box 1 to communicate with the transfer tank 4 without a gap between the shield box 1 and the transfer tank 4. Effectively avoid the aerosol in shielded cell 1 to leak through the clearance between shielded cell 1 and transfer tank 4. In the production process, an operator can directly deliver the generated waste into the transfer tank 4 through the waste port 11.

When the waste materials need to be transported, the hand wheel 32 is shifted to enable the lifting platform 31 to descend, and then the shielding box 1 is separated from the transporting tank 4. After the shielding box 1 is separated from the transfer tank 4, the feed port 41 of the transfer tank 4 is covered with the sealing cover 42. The waste material can then be transferred by pushing the transfer trolley 2.

In practice, the transfer tank 4 is internally provided with a stainless steel barrel 45. And (5) transferring the waste to a designated position and then locking the roller. After the solid waste in the stainless steel barrel 45 reaches the decay standard, the sealing cover 42 is opened, and the stainless steel barrel 45 in the tank body is taken out for subsequent treatment. Meanwhile, the transfer tank 4 is provided with a seal cover 42 and an annular butt lead cover 46. The opening part cooperation butt joint lead cover 46 of transfer tank 4 sets up and is the echelonment, and the butt joint lead cover 46 lid is located after transfer tank 4, and transfer tank 4 top is the top surface of butt joint lead cover 46 promptly, and the lower bottom surface of the top surface laminating shielded cell 1 of convenient butt joint lead cover 46. Simultaneously, the internal diameter of butt joint lead cover 46 is less than the internal diameter of transporting jar 4 for when transporting jar 4 is located to butt joint lead cover 46 lid, the opening of transporting jar 4 is less than the internal diameter of stainless steel bucket 45, guarantees that the waste material can be thrown into in the stainless steel bucket 45 all the time. The inner aperture of the docking lead cap 46 is disposed in cooperation with the sealing cap 42 such that the sealing cap 42 can be capped on the docking lead cap 46.

This kind of radioactivity is useless admittedly and is collected transfer device can communicate shielded cell 1, makes things convenient for the waste material directly to deliver to transfer tank 4 and also avoids waste material shielding cell 1 to keep in to cause the space extravagant. While also avoiding aerosol leakage inside the shielding cage 1. The waste material is directly delivered to the transfer tank 4, so that the waste material is not required to be taken out or sealed and packaged during transferring, the process is simplified, and aerosol leakage is avoided. The cooperation of the transfer tank 4 and the transfer trolley 2 greatly facilitates the transfer of the waste material. In addition, the transfer tank 4 can be replaced at will, and the use is convenient.

In this embodiment, the lifting platform 31 is provided with a plurality of guide rods 38. A plurality of guide rods 38 are vertically provided to the base plate 21. In practice, the guide rods are arranged at 4 and distributed at four corners of the lifting platform 31. The top ends of the two guide rods positioned at the front end of the transfer trolley 2 are connected with the first support frame 23; the top ends of the two guide rods at the rear end of the transfer trolley 2 are connected to a second support frame 24. The guide rod is used for stabilizing the lifting platform 31, and the lifting platform 31 can be stably lifted along the guide rod.

In this embodiment, a seal ring 43 is provided between the transfer tank 4 and the shield box 1. When transferring jar 4 and supporting tight shield box 1 bottom, transferring jar 4 and shield box 1 clamp tightly sealing ring 43, and then sealed, effectively avoid the aerosol in the shield box 1 to leak through the clearance between transferring jar 4 and the shield box 1. Meanwhile, when the sealing cover 42 covers the feeding hole 41, the sealing cover 42 and the transfer tank 4 clamp the sealing ring 43, so that the aerosol in the transfer tank 4 is effectively prevented from leaking through the gap between the transfer tank 4 and the sealing cover 42. In practice, two sealing rings 43 are provided. Namely, the shielding box 1 and the butt lead cover 46 are provided with the sealing ring 43, and the upper surface of the butt lead cover 46 is provided with the sealing ring 43. The sealing ring 43 abutting on the upper surface of the lead cover 46 can seal between the shielding box 1 and the abutting lead cover 46, and can also seal between the abutting lead cover 46 and the sealing cover 42.

In this embodiment, a positioning pit 44 is formed below the shielding box 1 and matched with the wheel of the transfer trolley 2, so that when the wheel enters the positioning pit 44, the feed port 41 is positioned right below the waste port 11. When the transfer trolley 2 is pushed in, the wheels enter the positioning pits 44, so that the feed port 41 is positioned right below the waste port 11, and the use by an operator is facilitated.

Example 2:

this embodiment is a modification of embodiment 1. As shown in fig. 4, the lifting platform 3 includes a lifting table 31, a first lifting rod 39, a second lifting rod 391, a screw pair, and a hand wheel 32. The trolley 2 comprises a floor 21 and a handle 22 attached to the floor 21. The screw pair includes a screw 33 and a nut 34.

The first lifting rod 39 and the second lifting rod 391 are arranged in a crossed manner, and the middle part of the first lifting rod 39 is hinged to the middle part of the second lifting rod 391. The first lift lever 39 and the second lift lever 391 are provided in a scissor shape. One end of the first lifting rod 39 is hinged to the bottom plate 21, and the other end is slidably disposed at the bottom of the lifting platform 31. One end of the second lifting rod 391 is hinged to the bottom of the lifting platform 31, and the other end is hinged to the nut 34. The first lifting rod 39 is located at the same side as the hinged end of the bottom plate 21 and the hinged end of the second lifting rod 391 as the lifting platform 31.

The base plate 21 is provided with a slide groove with a width slightly larger than that of the nut 34 in cooperation with the nut 34 so that the nut 34 can slide in the slide groove. One end of the screw 33 is connected with the hand wheel 32, so that the nut 34 can slide along the sliding groove by rotating the hand wheel 32.

During the use, stir hand wheel 32 and can make elevating platform 31 go up and down, and then make transport jar 4 laminating shielding case 1 or make transport jar 4 break away from shielding case 1.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A radioactive solid waste collecting and transferring device is matched with a shielding box (1) for use; a waste material port (11) is formed in the bottom of the shielding box (1); the method is characterized in that: the radioactive solid waste collecting and transferring device comprises a transfer trolley (2) and a transfer tank (4); the transfer trolley (2) is provided with a lifting platform (3); the transfer tank (4) is arranged in a manner of being matched with the lifting platform (3) so that the transfer tank (4) can be placed on the lifting platform (3); transfer jar (4) top cooperation feed inlet (41) have been seted up in waste material mouth (11), so that feed inlet (41) can communicate waste material mouth (11).

2. The radioactive solid waste collecting and transferring device according to claim 1, wherein: the lifting platform (3) comprises a lifting platform (31), a screw pair and a hand wheel (32); the hand wheel (32) is connected with the lead screw pair in a transmission way; the lifting platform (31) is arranged in a matching mode with the lead screw pair, so that the lead screw pair can drive the lifting platform (31) to lift.

3. The radioactive solid waste collecting and transferring device according to claim 2, wherein: the transfer trolley (2) comprises a bottom plate (21) and a handle (22) connected to the bottom plate (21); the screw pair comprises a screw (33) and a nut (34); the screw (33) is vertically arranged on the bottom plate (21) in a rotatable manner; a first bevel gear (36) is arranged at the top end of the screw rod (33); the hand wheel (32) is connected with a transmission rod (35); one end of the transmission rod (35) is provided with a second bevel gear (37) in a matching way with the first bevel gear (36), so that the transmission rod (35) can drive the screw rod (33) to rotate;

the lifting platform (31) is connected to the nut (34) so that the lifting platform (31) can lift along with the nut (34).

4. The radioactive solid waste collecting and transferring device according to claim 3, wherein: the lifting platform (31) is provided with a plurality of guide rods (38); a plurality of guide rods (38) are vertically arranged on the bottom plate (21).

5. The radioactive solid waste collecting and transferring device according to claim 4, wherein: the lifting platform (31) is provided with 4 guide rods (38); the 4 guide rods (38) are respectively positioned at four corners of the lifting platform (31).

6. The radioactive solid waste collecting and transferring device according to claim 1, wherein: the transfer tank (4) is also provided with a sealing cover (42).

7. The radioactive solid waste collecting and transferring device according to claim 1, wherein: a sealing ring (43) is arranged between the transfer tank (4) and the shielding box (1).

8. The radioactive solid waste collecting and transferring device according to claim 1, wherein: and a positioning pit (44) is arranged below the shielding box (1) and matched with the wheel of the transfer trolley (2), so that when the wheel enters the positioning pit (44), the feed port (41) is positioned right below the waste port (11).

9. The radioactive solid waste collecting and transferring device according to claim 1, wherein: the lifting platform (3) comprises a lifting platform (31), a first lifting rod (39), a second lifting rod (391), a screw pair and a hand wheel (32); the transfer trolley (2) comprises a bottom plate (21) and a handle (22) connected to the bottom plate (21); the screw pair comprises a screw (33) and a nut (34);

the first lifting rod (39) and the second lifting rod (391) are arranged in a crossed manner, and the first lifting rod (39) is hinged to the second lifting rod (391); one end of the first lifting rod (39) is hinged to the bottom plate (21), and the other end of the first lifting rod is slidably arranged at the bottom of the lifting platform (31); one end of the second lifting rod (391) is hinged to the bottom of the lifting platform (31), and the other end of the second lifting rod is hinged to the nut (34);

the bottom plate (21) is provided with a sliding groove matched with the nut (34) so that the nut (34) can slide in the sliding groove; one end of the screw rod (33) is connected with the hand wheel (32), so that the nut (34) can slide along the sliding groove by rotating the hand wheel (32).