CN221066789U - Batching device for compression-resistant concrete - Google Patents

Abstract

The utility model provides a proportioning device for compression-resistant concrete, which comprises a mixing box, wherein limiting plates are fixedly connected to the left side and the right side of the bottom of the mixing box, a bottom plate is fixedly connected to the bottom of each limiting plate, a first slot is arranged between the limiting plates, a first sliding slot is formed in the opposite side of each limiting plate, a collecting mechanism is arranged in the first slot, a driving motor is fixedly connected to the left side of the mixing box, a premixing cylinder is fixedly connected to the top of the mixing box, a material collecting bin is fixedly connected to the top of the premixing cylinder, a proportioning mechanism is arranged at the top of the material collecting bin, a mixing inner cylinder is fixedly connected to the inside of the mixing box, a discharging pipe communicated with the first slot is fixedly connected to the bottom of the mixing inner cylinder, and an electric control valve is fixedly sleeved on the outer side of the discharging pipe.

Description

Batching device for compression-resistant concrete

Technical Field

The utility model mainly relates to the technical field of compression-resistant concrete batching devices, in particular to a compression-resistant concrete batching device.

Background

The concrete is an artificial material, which is prepared by mixing cement, sand, stones, water and other materials according to a certain proportion. The composite material has high strength and durability, and is widely applied to projects such as buildings, bridges, roads and the like. The compressive strength of concrete is one of the most important properties, and is also one of the key factors which must be considered in the construction engineering design; the compressive strength of concrete refers to the maximum pressure that the concrete can withstand when subjected to pressure. The compressive strength of concrete is related to the factors of the composition materials, the mixing ratio, the manufacturing process, the curing conditions and the like. In the concrete production, the raw materials of the concrete are required to be subjected to the batching operation, and therefore, a batching device for the compression-resistant concrete is required to be used.

Through searching, for example, the utility model patent with the publication number of CN212978763U discloses a batching device for concrete, which comprises a box body, four corners of the bottom of the box body are fixedly connected with supporting legs, two sides of the top of the box body are communicated with vertical pipes, the tops of the vertical pipes are communicated with a storage bin, the inner wall of the storage bin is fixedly connected with a transverse plate, one end, far away from the inner wall of the storage bin, of the transverse plate is fixedly connected with a first motor, the bottom of a rotating shaft of the first motor is fixedly connected with a vertical rod, the bottom of the vertical rod extends to the inner cavity of the vertical pipe, a spiral blade is fixedly sleeved on the surface of the vertical rod, and the top of the box body is fixedly connected with a second motor; this patent possesses evenly carrying the material, is favorable to the subsequent mixed processing of material, and the advantage of material misce bene has solved current concrete dosing unit and can not carry out even transport to the material, is unfavorable for the subsequent mixed processing of material for the material misce bene has reduced dosing unit's suitability, the problem that is inconvenient for people to use.

Among the above-mentioned patent technical scheme, cooperate through box, landing leg, standpipe, feed bin, diaphragm, first motor, montant, helical blade, second motor, (mixing) shaft, stirring leaf, discharging pipe and controller, possess and evenly carry the material, be favorable to the follow-up mixed processing of material, the advantage of material misce bene. However, the technical scheme of the patent still has the following defects in the using process:

1. When the technical scheme of the patent is used, raw materials can not be measured on the weight of raw material filling in the filling process, so that deviation in proportion easily occurs in the raw material filling process, and the compression quality of concrete is reduced.

2. When the technical scheme of the patent is used, the mixed materials are not convenient to collect, and meanwhile, dust cannot be treated during discharging, so that the dust is easy to fly away, and the damage is caused to the health of processing workers.

We therefore provide a dosing device for compression concrete to address the above-mentioned drawbacks.

Disclosure of utility model

The utility model mainly provides a batching device for compression-resistant concrete, which is used for solving the technical problems in the background technology.

The technical scheme adopted for solving the technical problems is as follows:

the utility model provides a dosing unit of compressive concrete, includes the mixing box, the equal fixedly connected with limiting plate in left and right sides of mixing box bottom, limiting plate bottom fixedly connected with bottom plate, be equipped with fluting one between the limiting plate, spout one has all been seted up to limiting plate opposite side, fluting one inside is equipped with collection mechanism, mixing box left side fixedly connected with driving motor, mixing box top fixedly connected with mixes a section of thick bamboo in advance, mix a section of thick bamboo top fixedly connected with collection silo in advance, collection silo top is equipped with dosing mechanism, the inside fixedly connected with of mixing box mixes the inner tube, mix the unloading pipe of inner tube bottom fixedly connected with and a fluting intercommunication, unloading pipe outside fixed cover is equipped with the electrically controlled valve, mix the inside mixing mechanism that is equipped with of inner tube.

Further, feed proportioning mechanism includes the unloading bucket of fixed connection in aggregate bin top, unloading bucket top fixedly connected with batching bucket, four equal fixedly connected with landing legs in corner of batching bucket bottom, batching bucket top sliding connection has the top cap, the fluting second has been seted up to unloading bucket front end, spout second has all been seted up to fluting second left and right sides inner wall, fluting second inside is equipped with the baffle, baffle top fixedly connected with weighing sensor, baffle front end left side fixedly connected with display screen, baffle front end fixedly connected with connecting rod, connecting rod front end fixedly connected with pull rod, the equal fixedly connected with slide bar of baffle left and right sides.

Further, the batching bucket is equipped with three altogether, every the landing leg that four corners in bottom set up and aggregate bin top fixed connection all, the baffle is equipped with three altogether, every the baffle all passes through connecting rod and pull rod fixed connection, just every the baffle all passes through slide bar one that the left and right sides set up and two slide connection of spout two left and right sides inner walls of fluting set up.

Further, the mixing mechanism includes the protection casing of fixed connection in the left side inner wall of mixed inner tube, the inside horizontal bull stick that is equipped with of protection casing, horizontal bull stick right-hand member fixedly connected with vertical bevel gear, the inside and be located vertical bevel gear right side of protection casing is equipped with vertical bull stick, vertical bull stick is located the inside outside fixed cover of protection casing and is equipped with horizontal bevel gear, the inside outside top fixed cover of protection casing is extended to vertical bull stick is equipped with the premixed puddler, vertical bull stick extends the outside of protection casing inside and is located the fixed cover in premixed puddler below and is equipped with the mixed puddler.

Further, the driving motor output extends to the inside of the protection casing and is fixedly connected with the left end of the transverse rotating rod, the vertical bevel gear is meshed with the transverse bevel gear, the bottom of the vertical rotating rod is rotationally connected with the bottom inside the protection casing through a bearing, the premixing stirring rod is located inside the premixing barrel, the diameter of the premixing stirring rod corresponds to the inner diameter of the premixing barrel, the mixing stirring rod is located inside the mixing inner barrel, and the diameter of the mixing stirring rod corresponds to the inner diameter of the mixing inner barrel.

Further, collection mechanism includes sliding connection in the inside collection steamer tray of fluting, the equal fixedly connected with auto-lock universal wheel in four corners in collection steamer tray bottom, the equal fixedly connected with slide bar two in collection steamer tray left and right sides, collection steamer tray front end fixedly connected with hand lever, spout three has all been seted up to collection steamer tray left and right sides inner wall, be equipped with the closing plate between the spout three, the rear end of closing plate left and right sides just is located the three equal fixedly connected with spacing slider of spout.

Further, the sealing plate is in sliding connection with three sliding grooves formed in the inner walls of the left side and the right side through limit sliding blocks arranged at the rear ends of the left side and the right side.

Compared with the prior art, the utility model has the beneficial effects that:

1. According to the utility model, through the arranged batching mechanism, a top cover is opened by a processor, concrete raw materials (cement, sand and stones) are respectively added into different batching barrels, at the moment, a weighing sensor arranged on a partition board weighs the raw materials (cement, sand and stones) and displays numerical values through a display screen for the processor to read, when the proportion of the raw materials (cement, sand and stones) to be filled is qualified, the top cover is closed, then a pull rod is pulled to enable three partition boards to be simultaneously pulled out, and different raw materials (cement, sand and stones) simultaneously fall into a collecting bin to carry out mixing batching work, so that when the batching device for the compression-resistant concrete is used, the weight of the raw materials to be filled can be measured in the raw material filling process, the deviation in proportion is prevented, and the compression-resistant concrete quality is improved.

2. According to the utility model, the mixing mechanism and the collecting mechanism are matched for use, the driving motor is started to drive the transverse rotating rod to rotate, so that the transverse conical gear is driven to rotate under the action of the vertical conical gear, the transverse conical gear is fixedly sleeved with the vertical rotating rod, the vertical rotating rod is driven to rotate, the premixing stirring rod and the mixing stirring rod rotate to mix raw materials (cement, sand and stones), the raw materials (cement, sand and stones) in the falling aggregate bin enter the premixing barrel first, at the moment, the rotating premixing stirring rod performs premixing operation on the entered raw materials (cement, sand and stones), the premixed raw materials (cement, sand and stones) enter the inside of the mixing barrel, at the moment, the rotating mixing stirring rod sufficiently mixes the raw materials (cement, sand and stones), after the mixing is completed, the sealing plate is pulled open, the electric control valve is opened, the mixed raw materials (cement, sand and stones) fall into the collecting drawer through the blanking pipe to be intensively collected, and after the mixed raw materials (cement, sand and stones) completely enter the collecting drawer, the sealing plate is pushed to perform premixing operation on the top, and the dust-proof device can be well-distributed when the mixing device is used for dust-proof, and the dust-proof and well-conditioned, and the dust-proof device can be well processed to prevent dust from being carried out.

Drawings

FIG. 1 is a schematic diagram of the overall structure of the present utility model;

FIG. 2 is a schematic diagram of a batching mechanism according to the present utility model;

FIG. 3 is a schematic diagram of a slot structure according to the present utility model;

FIG. 4 is a schematic view of the structure of the collecting mechanism of the present utility model;

FIG. 5 is an enlarged view of area A of FIG. 4;

fig. 6 is a schematic diagram of the overall internal front view structure of the present utility model.

In the figure: 1. a mixing box; 101. a limiting plate; 102. a bottom plate; 103. a driving motor; 104. slotting I; 105. a first chute; 106. a premix barrel; 107. a collecting bin; 108. mixing the inner cylinder; 109. discharging pipes; 110. an electric control valve; 2. a batching mechanism; 201. discharging barrels; 202. a dosing barrel; 203. a support leg; 204. a top cover; 205. slotting II; 206. a second chute; 207. a partition plate; 208. a weighing sensor; 209. a first slide bar; 210. a display screen; 211. a connecting rod; 212. a pull rod; 3. a collection mechanism; 301. a collection drawer; 302. self-locking universal wheels; 303. a second slide bar; 304. a hand pull rod; 305. a sealing plate; 306. a chute III; 307. a limit sliding block; 4. a mixing mechanism; 401. a protective cover; 402. a transverse rotating rod; 403. vertical bevel gears; 404. a vertical rotating rod; 405. premixing stirring rod; 406. mixing stirring rod; 407. transverse bevel gears.

Detailed Description

In order that the utility model may be more fully understood, a more particular description of the utility model will be rendered by reference to the appended drawings, in which several embodiments of the utility model are illustrated, but which may be embodied in different forms and are not limited to the embodiments described herein, which are, on the contrary, provided to provide a more thorough and complete disclosure of the utility model.

Referring to fig. 1-6, an embodiment of a batching device for compression-resistant concrete includes a mixing box 1, limiting plates 101 are fixedly connected to the left and right sides of the bottom of the mixing box 1, a bottom plate 102 is fixedly connected to the bottom of the limiting plates 101, a first slot 104 is arranged between the limiting plates 101, a first slot 105 is formed in one opposite side of the limiting plates 101, a collecting mechanism 3 is arranged in the first slot 104, a driving motor 103 is fixedly connected to the left side of the mixing box 1, a premixing barrel 106 is fixedly connected to the top of the mixing box 1, a collecting bin 107 is fixedly connected to the top of the premixing barrel 106, a batching mechanism 2 is arranged at the top of the collecting bin 107, a mixing inner barrel 108 is fixedly connected to the inside of the mixing box 1, a blanking pipe 109 communicated with the first slot 104 is fixedly connected to the bottom of the mixing inner barrel 108, an electric control valve 110 is fixedly sleeved on the outer side of the blanking pipe 109, and a mixing mechanism 4 is arranged inside the mixing inner barrel 108.

Wherein, the batching mechanism 2 comprises a blanking barrel 201 fixedly connected with the top of a collecting bin 107, a batching barrel 202 is fixedly connected with the top of the blanking barrel 201, four corners at the bottom of the batching barrel 202 are fixedly connected with supporting legs 203, a top cover 204 is slidingly connected with the top of the batching barrel 202, a second slot 205 is arranged at the front end of the blanking barrel 201, a second slide slot 206 is arranged on the inner walls of the left side and the right side of the second slot 205, a baffle 207 is arranged in the second slot 205, a weighing sensor 208 is fixedly connected with the top of the baffle 207, a display screen 210 is fixedly connected with the left side of the front end of the baffle 207, a connecting rod 211 is fixedly connected with the front end of the connecting rod 211, a pull rod 212 is fixedly connected with the left side and the right side of the baffle 207, a slide rod 209 is fixedly connected with the left side and the right side of the baffle 207, the batching barrel 202 is provided with three in total, each batching barrel 202 is fixedly connected with the top of the collecting bin 107 through the supporting legs 203 arranged at the four corners at the bottom, each partition 207 is fixedly connected with a pull rod 212 through a connecting rod 211, each partition 207 is in sliding connection with a sliding groove two 206 formed in the inner walls of the left side and the right side of a groove two 205 through a sliding rod one 209 arranged on the left side and the right side, a top cover 204 is opened by a processing staff, concrete raw materials (cement, sand and stones) are respectively added into different batching barrels 202, at the moment, weighing sensors 208 arranged on the partition 207 weigh the raw materials (cement, sand and stones) and display the numerical values through a display screen 210 for the processing staff to read, when the filling proportion of the raw materials (cement, sand and stones) is qualified, the top cover 204 is closed, then the pull rod 212 is pulled to enable the three partition 207 to be simultaneously pulled out, and different raw materials (cement, sand and stones) simultaneously fall into a collecting bin 107 to carry out mixing batching work, so that when the batching device for the compression-resistant concrete is used, the weight of raw material filling can be measured in the raw material filling process, the deviation of the proportion is prevented, and the compression-resistant concrete quality is improved.

Wherein, mixing mechanism 4 includes the protection casing 401 fixed connection in the left side inner wall of mixing drum 108, the protection casing 401 inside is equipped with horizontal bull stick 402, horizontal bull stick 402 right-hand member fixedly connected with vertical bevel gear 403, the inside just be located vertical bevel gear 403 right side of protection casing 401 is equipped with vertical bull stick 404, vertical bull stick 404 is located the inside outside fixed cover of protection casing 401 and is equipped with horizontal bevel gear 407, the outside top fixed cover that vertical bull stick 404 extends the protection casing 401 inside is equipped with premix puddler 405, vertical bull stick 404 extends the outside of protection casing 401 inside and is located the fixed cover of premix puddler 405 below and is equipped with mix puddler 406, driving motor 103 output extends to the protection casing 401 inside and with horizontal bull stick 402 left end fixed connection, vertical bevel gear 403 and horizontal bevel gear 407 meshing are connected, vertical bull stick 404 bottom is connected with the inside bottom through bearing and the inside bottom rotation of protection casing 401, and premix puddler 405 is located the inside of premix drum 106, the diameter of premix puddler 405 and the internal diameter of premix drum 106 are corresponding, mix puddler 406 is located the inside of mixing drum 108, the inside, outside top fixed cover is equipped with premix puddler 405, it is rotatory to drive the horizontal conical gear 103 through the start-up driving motor 103, thereby make vertical bevel gear 403 extend to the inside and mix puddler 405, the effect of mix the cement, mix the raw materials (mix the mortar) and mix the mortar (the cement) and mix the mortar) and mix the cement and mix the mortar (the mix the mortar) and the mix puddler (the cement) and the mix puddler) and the mix the cement and the mix mortar) and the cement and the mix mortar by the cement and mix mortar and the mix mortar by the mix mortar and the cement and mix mortar by the cement Sand, stone) to be premixed, and the premixed raw materials (cement, sand, stone) enter the mixing inner cylinder 108, and at this time, the rotating mixing stirring rod 406 sufficiently mixes the raw materials (cement, sand, stone) so that the raw materials can be sufficiently mixed when the batching device for the compression-resistant concrete is used.

The collecting mechanism 3 comprises a collecting drawer 301 which is slidably connected to the first slot 104, self-locking universal wheels 302 are fixedly connected to four corners at the bottom of the collecting drawer 301, sliding rods 303 are fixedly connected to the left side and the right side of the collecting drawer 301, hand pull rods 304 are fixedly connected to the front ends of the collecting drawer 301, sliding grooves 306 are formed in the inner walls of the left side and the right side of the collecting drawer 301, sealing plates 305 are arranged between the three sliding grooves 306, limiting sliding blocks 307 are fixedly connected to the rear ends of the left side and the right side of the sealing plates 305 and are slidably connected with the three sliding grooves 306 formed in the inner walls of the left side and the right side of the sealing plates 305 through the limiting sliding blocks 307 arranged at the rear ends of the left side and the right side, after the mixing is completed, the sealing plates 305 are pulled open, then the electric control valve 110 is opened, mixed raw materials (cement, sand and stones) fall into the collecting drawer 301 through the blanking pipes 109 to be collected intensively, the mixed raw materials (cement, sand and stones) are pushed to seal the tops of the collecting drawer 301 after all entering the collecting drawer 301, so that the top of the collecting drawer 305 is sealed, a dustproof effect is achieved, the batching device is convenient for mixing and dust-proof and can be processed, dust can be well removed, and dust can be prevented from being well processed when the dust is well processed.

The specific operation mode of the utility model is as follows:

Firstly, a processing person opens the top cover 204 to respectively add concrete raw materials (cement, sand and stones) into different batching barrels 202, at this time, a weighing sensor 208 arranged on a partition 207 weighs the raw materials (cement, sand and stones) and displays the numerical value through a display screen 210 for the processing person to read, when the filling proportion of the raw materials (cement, sand and stones) is qualified, the top cover 204 is closed, then a pull rod 212 is pulled to simultaneously draw out the three partition 207, and different raw materials (cement, sand and stones) simultaneously drop into a collecting bin 107 to perform mixing batching work, so that when the batching device of the compression-resistant concrete is used, the weight of raw material filling can be measured in the raw material filling process, the deviation of the proportion is prevented, the compression-resistant concrete quality is improved, then the driving motor 103 is started to drive the transverse rotating rod 402 to rotate, so that the vertical bevel gear 403 rotates, the transverse bevel gear 407 is driven to rotate under the action of the vertical bevel gear 403, and the transverse bevel gear 407 is fixedly sleeved with the vertical rotating rod 404, so that the vertical rotating rod 404 is driven to rotate, the premixing stirring rod 405 and the mixing stirring rod 406 rotate to mix raw materials (cement, sand and stones), the raw materials (cement, sand and stones) falling into the collecting bin 107 enter the premixing barrel 106 first, the premixing stirring rod 405 rotates to premix the entered raw materials (cement, sand and stones), the premixed raw materials (cement, sand and stones) enter the mixing inner barrel 108, the rotating mixing stirring rod 406 fully mixes the raw materials (cement, sand and stones), after the mixing is completed, the sealing plate 305 is pulled open, then the electric control valve 110 is opened, the mixed raw materials (cement, sand and stones) fall into the collecting drawer 301 through the blanking pipe 109 to be collected in a concentrated mode, after the mixed raw materials (cement, sand and stones) all enter the collecting drawer 301, the sealing plate 305 is pushed to seal the top of the collecting drawer 301, so that a dustproof effect is achieved, finally, workers pull the collecting drawer 301 out through the self-locking universal wheels 302 through the hand pull rods 304, and the mixed concrete raw materials are processed in the next step.

While the utility model has been described above with reference to the accompanying drawings, it will be apparent that the utility model is not limited to the embodiments described above, but is intended to be within the scope of the utility model, as long as such insubstantial modifications are made by the method concepts and technical solutions of the utility model, or the concepts and technical solutions of the utility model are applied directly to other occasions without any modifications.

Claims (7)

1. The utility model provides a dosing unit of compressive concrete, includes mixing box (1), its characterized in that: the utility model discloses a mixing box, including mixing box (1), fixed connection, feed proportioning mechanism (2), mixing box (1), electric control valve (110) are equipped with feed proportioning mechanism (4), mixing box (1) left and right sides all fixedly connected with limiting plate (101) bottom, limiting plate (101) bottom fixedly connected with bottom plate (102), be equipped with fluting one (104) between limiting plate (101), spout one (105) have all been seted up to limiting plate (101) opposite side, fluting one (104) inside is equipped with collection mechanism (3), mixing box (1) left side fixedly connected with driving motor (103), mixing box (1) top fixedly connected with mixes section of thick bamboo (106), mix section of thick bamboo (106) top fixedly connected with collection silo (107), collection silo (107) top is equipped with feed proportioning mechanism (2), mixing box (1) inside fixedly connected with mixes inner tube (108), mix inner tube (108) bottom fixedly connected with and fluting one (104) feed proportioning tube (109), feed tube (109) outside fixed cover is equipped with electric control valve (110), mix inner tube (108) inside is equipped with mixing mechanism (4).

2. A batching device for compressive concrete according to claim 1, wherein: the batching mechanism (2) comprises a blanking barrel (201) fixedly connected to the top of a collecting bin (107), the blanking barrel (201) is fixedly connected with a batching barrel (202), four corners of the bottom of the batching barrel (202) are fixedly connected with supporting legs (203), the top of the batching barrel (202) is slidably connected with a top cover (204), a slotting second (205) is formed in the front end of the blanking barrel (201), sliding grooves second (206) are formed in the inner walls of the left side and the right side of the slotting second (205), a partition plate (207) is arranged in the slotting second (205), a weighing sensor (208) is fixedly connected to the top of the partition plate (207), a display screen (210) is fixedly connected to the left side of the front end of the partition plate (207), a connecting rod (211) is fixedly connected with a pull rod (212), and a sliding rod (209) is fixedly connected to the left side and the right side of the partition plate (207).

3. A batching device for compressive concrete according to claim 2, wherein: the batching bucket (202) is equipped with three altogether, every batching bucket (202) all sets up landing leg (203) and aggregate bin (107) top fixed connection through four corners in the bottom, baffle (207) are equipped with three altogether, every baffle (207) all pass through connecting rod (211) and pull rod (212) fixed connection, just every baffle (207) all pass through slide bar one (209) that the left and right sides set up and spout two (206) sliding connection that the inner wall of fluting two (205) left and right sides was seted up.

4. A batching device for compressive concrete according to claim 1, wherein: mixing mechanism (4) are including fixed connection in protection casing (401) of mixing inner tube (108) left side inner wall, the inside horizontal bull stick (402) that is equipped with of protection casing (401), vertical bevel gear (403) of horizontal bull stick (402) right-hand member fixedly connected with, the inside vertical bull stick (404) that just is located vertical bevel gear (403) right side of protection casing (401), vertical bull stick (404) are located the inside outside fixed cover of protection casing (401) and are equipped with horizontal bevel gear (407), vertical bull stick (404) extend the inside outside top fixed cover of protection casing (401) and are equipped with premixing puddler (405), vertical bull stick (404) extend the inside outside of protection casing (401) and are located the fixed cover in premixing puddler (405) below and are equipped with mixing puddler (406).

5. The concrete-resistant proportioning device of claim 4, wherein: the output end of the driving motor (103) extends into the protective cover (401) and is fixedly connected with the left end of the transverse rotating rod (402), the vertical bevel gear (403) is meshed with the transverse bevel gear (407), the bottom of the vertical rotating rod (404) is rotationally connected with the bottom end of the interior of the protective cover (401) through a bearing, and premixing stirring rod (405) is located inside premixing tube (106), diameter of premixing stirring rod (405) corresponds with the internal diameter of premixing tube (106), mixing stirring rod (406) is located inside mixing inner tube (108), and diameter of mixing stirring rod (406) corresponds with the internal diameter of mixing inner tube (108).

6. A batching device for compressive concrete according to claim 1, wherein: the collection mechanism (3) comprises a collection drawer (301) which is connected inside a groove I (104) in a sliding manner, self-locking universal wheels (302) are fixedly connected to four corners of the bottom of the collection drawer (301), two sliding rods (303) are fixedly connected to the left side and the right side of the collection drawer (301), three sliding grooves (306) are formed in the inner walls of the left side and the right side of the collection drawer (301), sealing plates (305) are arranged between the three sliding grooves (306), and limit sliding blocks (307) are fixedly connected to the rear ends of the left side and the right side of the sealing plates (305) and located inside the three sliding grooves (306).

7. The concrete-resistant proportioning device of claim 6, wherein: the sealing plate (305) is in sliding connection with a sliding groove III (306) formed in the inner walls of the left side and the right side through limit sliding blocks (307) arranged at the rear ends of the left side and the right side.