Preparation device and process of hydrophobic lightweight concrete

Abstract

The invention discloses a preparation device and process of hydrophobic lightweight concrete, and relates to the technical field of concrete processing, the preparation device comprises a base, a pedestal, a die holder, a vibration mechanism, a pressing plate, a hydraulic cylinder, a height adjusting mechanism and a one-way valve structure; the height adjusting mechanism communicates with the exhaust channel and is configured to drive the pressing plate to descend relative to the hydraulic cylinder through the pressure of gas entering the exhaust channel so as to reduce the distance between the pressing plate and the upper surface of the raw material. According to the invention, the special one-way valve structure is arranged on the pressing plate and matched with the up-and-down reciprocating motion of the die holder, so that air extruded from raw materials can be actively exhausted to the exhaust channel in the vibration process, and most of air can be effectively exhausted even if the vibration time is relatively short, so that the tap density of the raw materials is ensured, and the production efficiency is improved. And the layering phenomenon of light and heavy materials caused by long-time vibration is avoided, so that the overall quality and the yield of the lightweight concrete are remarkably improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of concrete processing, in particular to a preparation device and process of hydrophobic lightweight concrete. BACKGROUND

[0002] Lightweight concrete is also known as light aggregate concrete, which is prepared by light coarse aggregate (ceramsite), ordinary sand, cement and water, and its density is not greater than 1900 kg / m³. According to the fine aggregate, it is divided into full lightweight concrete (light sand) and sand lightweight concrete (ordinary sand). Dry mixing composite light aggregate concrete is prepared by cement, fly ash, additive and waste polyurethane particles, and its strength grade covers LC15-LC60. While the unit weight is 20%-30% lower than that of ordinary concrete, the elastic modulus is reduced by 25%-65%, and the thermal conductivity is only 12%-33% of that of ordinary concrete. It is mainly used for floor, roof cushion and slope layer.

[0003] When preparing lightweight concrete, a vibrating device is needed to vibrate the raw material mortar to discharge most of the air in the raw material mortar. During the vibration of the raw material of lightweight concrete, the light material in the raw material will float up due to the influence of buoyancy, and then the light material and the heavy material will easily stratify during the vibration, which will affect the quality of the lightweight concrete. Therefore, in order to avoid the stratification of ceramic particles and other light aggregates caused by floating up under long-time vibration, the vibration time of the current vibrating device is shortened, but this will cause too much air to remain in the raw material, affecting the compactness and strength of the concrete and affecting the quality of the lightweight concrete. SUMMARY

[0004] The purpose of the present application is to provide a preparation device and process of hydrophobic lightweight concrete to solve the problems raised in the background.

[0005] To achieve the above-mentioned purpose, the present application provides the following technical scheme: a preparation device of hydrophobic lightweight concrete, comprising a base, a pedestal, a mold base and a vibration mechanism, further comprising: a pressing plate arranged above the mold base, a hydraulic cylinder driving the pressing plate to lift, and a height adjusting mechanism connected between the hydraulic cylinder and the pressing plate; The pressing plate is provided with an exhaust passage, the exhaust passage has an air inlet at the bottom of the pressing plate, and a one-way valve structure is arranged at the air inlet. The one-way valve structure is configured to open to allow gas to enter the exhaust passage when the air pressure above the raw material in the mold base increases, and to close to block the backflow of gas when the air pressure decreases; The height adjusting mechanism is communicated with the exhaust passage and is configured to drive the pressing plate to descend relative to the hydraulic cylinder by using the gas pressure entering the exhaust passage, so as to reduce the distance between the pressing plate and the upper surface of the raw material.

[0006] Further, the one-way valve structure comprises a fixed plug part fixed to the bottom of the pressing plate, a movable plug part movably arranged in the fixed plug part, and a spring abutting against the movable plug part; A gas permeation groove is formed in the bottom of the fixed plug part and communicates with the exhaust passage, and the movable plug part is provided with a sealing part, and the spring abuts against the movable plug part to a position where the sealing part blocks the gas permeation groove.

[0007] Further, a communication opening is formed in the periphery of the movable plug part, and when the sealing part is separated from the gas permeation groove, gas enters the exhaust passage through the gas permeation groove and the communication opening.

[0008] Further, when the sealing part blocks the gas permeation groove, the lower surface of the sealing part, the lower surface of the fixed plug part, and the lower surface of the pressing plate are flush.

[0009] Further, the height adjusting mechanism comprises a rotating part rotatably connected to the end of the telescopic rod of the hydraulic cylinder, a connecting column threadedly connected with the rotating part, and a gear and rack assembly for driving the connecting column to rotate relative to the rotating part; The lower end of the connecting column is connected with the pressing plate, and the upper end thereof communicates with the exhaust passage.

[0010] Further, the gear and rack assembly comprises a gear fixedly sleeved in the periphery of the rotating part, a fixed arm fixedly sleeved on the connecting column, a hollow cylinder fixed to the fixed arm, a sliding plug slidingly arranged in the hollow cylinder, and a rack rod connected with the sliding plug; One end of the hollow cylinder communicates with the exhaust passage through an air pipe, and the rack rod is engaged with the gear, and when gas enters the hollow cylinder to push the sliding plug to move, the rack rod drives the gear to rotate.

[0011] Further, a threaded part is coaxially fixed to the upper end of the connecting column, a threaded hole is formed in the lower end of the rotating part, and the threaded part is threadedly matched with the threaded hole.

[0012] Further, the axial thickness dimension of the gear is greater than the longitudinal length dimension of the rack rod.

[0013] Further, a light axis is vertically fixed to the pressing plate, the light axis is arranged through a fixed plate fixed to the base, and the light axis is used for guiding the lifting of the pressing plate.

[0014] A preparation process of hydrophobic lightweight concrete is applied to the preparation device as described above, and comprises the following steps: Step one: load the lightweight concrete raw materials into the mold base, and fix the mold base on the base; Step two: start the hydraulic cylinder to drive the pressing plate down into the mold base, so that the bottom surface of the pressing plate and the upper surface of the raw materials maintain a preset distance; Step three: start the vibration motor to drive the mold base and the internal raw materials to reciprocate up and down; Step four: in the vibration process, the air pressure generated when the raw materials move up is used to open the one-way valve structure on the pressing plate, and the gas in the raw materials is discharged into the exhaust channel; At the same time, the gas pressure in the exhaust channel drives the height adjusting mechanism to automatically lower the pressing plate relative to the hydraulic cylinder, continuously vibrating and compacting the raw materials, and discharging until the preparation is completed.

[0015] Compared with the prior art, the beneficial effects of the present application are: 1、In the present application, by setting a special one-way valve structure (air slot and movable plug part) on the pressing plate, cooperating with the up-down reciprocating movement of the mold base, the air squeezed out of the raw materials can be actively discharged to the exhaust channel during the vibration process, even if the vibration time is short, most of the air can be effectively discharged, which not only ensures the vibration density of the raw materials, but also avoids the phenomenon of light and heavy material layering caused by long time vibration, thereby significantly improving the overall quality and yield of lightweight concrete; 2、In the present application, during the vibration process, as the air is discharged and the raw materials are compacted, the height of the raw material accumulation will decrease, resulting in an increase in the distance between the pressing plate and the upper surface of the raw materials, so that the air pressure cannot effectively push the one-way valve structure to open, thereby affecting the subsequent exhaust effect. The present application innovatively uses the discharged exhaust gas as a power source, and through the height adjusting mechanism (gear and rack assembly cooperates with screw transmission), the pressure of the gas is converted into mechanical power for the descent of the pressing plate. When the air pressure in the exhaust channel reaches a certain value, the pressing plate will automatically descend, automatically compensating for the distance caused by the decrease in the height of the raw materials, so that the pressing plate always maintains the best working distance with the raw materials, ensuring continuous and efficient exhaust during the entire vibration process; 3、In the present application, the spring and sealing part in the one-way valve structure ensure that the air inlet quickly closes when the mold base descends (the space becomes larger and the air pressure decreases). This not only prevents external air from re-entering the interior of the raw materials, but also forms a certain negative pressure environment between the pressing plate and the raw materials. This "suction" effect further promotes the overflow and rupture of air bubbles in the raw materials, improving the exhaust speed and effect. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 The overall structure of the preparation device for the hydrophobic lightweight concrete in the present application is shown in the figure; Figure 2 is Figure 1 The position relationship schematic diagram of the first perspective view of the structure in the present application is shown in the figure; Figure 3 As Figure 1 The schematic diagram of position relation of the structure from the second perspective view; Figure 4 The schematic diagram of position relation of the structure after the pressure plate, the hydraulic cylinder and the connecting column are assembled; Figure 5 As Figure 4 The schematic diagram of position relation of the structure from another perspective view; Figure 6 As Figure 4 The schematic diagram of position relation of the structure after the hydraulic cylinder is omitted; Figure 7 As Figure 6 The schematic diagram of position relation of the structure after part of the structure is cut open; Figure 8 As Figure 6 The schematic diagram of position relation of the structure after the structure is exploded; Figure 9 The schematic diagram of position relation of the structure after the fixed plug part, the connecting rod and the movable plug part are assembled; Figure 10 As Figure 9 The schematic diagram of position relation of the structure after the structure is exploded from the first perspective view; Figure 11 As Figure 9 The schematic diagram of position relation of the structure after the structure is exploded from the second perspective view; Figure 12 As Figure 9 The schematic diagram of position relation of part of the structure from the third perspective view after the structure is cut open; Figure 13 The schematic diagram of position relation of the structure after the connecting column, the fixed arm and the connecting arm are assembled; Figure 14 As Figure 13 The schematic diagram of position relation of part of the structure after the structure is cut open.

[0017] In the drawings, the following signs are explained as follows: 1, base; 2, shock absorber; 3, vibration motor; 4, base; 5, mold base; 6, stand column; 7, pressure plate; 8, connecting column; 9, optical axis; 10, hydraulic cylinder; 11, fixed arm; 12, connecting arm; 13, gear; 14, rotating part; 15, rack rod; 16, hollow cylinder; 17, fixed plug part; 18, threaded part; 19, connecting rod; 20, stop ring; 21, containing cavity; 22, movable plug part; 23, spring; 24, communication port; 25, sealing part; 26, air permeation groove; 27, sliding plug; 28, driving rod; 29, hollow part. DETAILED DESCRIPTION

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] Please see Figures 1-14 This invention provides a technical solution: a device for preparing hydrophobic lightweight concrete, comprising a base 1, a plurality of shock absorbers 2 mounted on the top of the base 1, the upper ends of the plurality of shock absorbers 2 being connected to a base 4, a vibration motor 3 mounted on the bottom of the base 4, the vibration motor 3 generating a vibration force on the base 4 when started, causing the base 4 to vibrate up and down reciprocally, a mold base 5 detachably mounted on the top of the base 4, the mold base 5 being bolted to the base 4, and the inner cavity of the mold base 5 being used to store an appropriate amount of lightweight concrete raw material, the vibration force transmitted to the concrete raw material when the vibration motor 3 is working, compacting the concrete raw material, making the raw material more compact. To ensure tightness and allow air to escape, two vertical columns 6 are installed on each side of the base 4. A fixing plate is installed on the upper end of the two columns 6, and a hydraulic cylinder 10 is installed vertically on the fixing plate. In this embodiment, the structure of the shock absorber 2 includes two positioning flange columns and a shock-absorbing spring. The positioning flange columns are respectively installed at the bottom of the base 4 and the top of the base 1, and the two positioning flange columns are installed in a vertically opposite position. The shock-absorbing spring is wrapped around the periphery of the two positioning flange columns, and the two ends of the shock-absorbing spring in the direction of the spring force are respectively wrapped around the two positioning flange columns. This allows the shock-absorbing spring to stretch and deform, thereby buffering the vibration force transmitted from the vibration motor 3 to the base 1 and avoiding damage to the placement surface of the base 1. Combination Figures 1 to 14 As shown, and please refer to the following: Figure 4 and Figure 8The telescopic rod of the hydraulic cylinder 10 is rotatably connected to a rotating part 14. Specifically, the top of the rotating part 14 has a bearing groove, in which a bearing is installed. The end of the telescopic rod of the hydraulic cylinder 10 is tightly fitted onto the inner ring of the bearing, thereby making the rotating part 14 rotatably connected to the telescopic rod of the hydraulic cylinder 10. The lower end of the rotating part 14 has a threaded hole coaxially connected to a threaded part 18, which can be screwed into the threaded hole. In addition, the lower end of the threaded part 18 extends out of the threaded hole and is coaxially fixed to a connecting post 8. The connecting post 8 is coaxial with the rotating part 14. The lower end of the connecting post 8 is connected to a pressure plate 7 by a screw. The pressure plate 7 is located directly above the mold base 5 and is in sliding fit with the inner cavity of the mold base 5. That is, when the pressure plate 7 moves downward, it can be inserted into the inner cavity of the mold base 5. Furthermore, it slides relative to the inner wall of the mold base 5. The lower end of the connecting column 8 is provided with a blind hole-type vent. In addition, a light axis 9 is vertically installed on the pressure plate 7. The upper end of the light axis 9 passes through the fixed plate and can slide freely up and down on the fixed plate. The light axis 9 guides and limits the pressure plate 7, so that the pressure plate 7 will not rotate circumferentially when it moves up and down. In addition, preferably, the number of light axes 9 is set to two, and they are located on opposite sides of the pressure plate 7. The two light axes 9 can guide the pressure plate 7 and make the two sides of the pressure plate 7 bear the force evenly, avoiding tilting. Furthermore, multiple stiffeners are fixed to the upper surface of the pressure plate 7. The stiffeners are used to reinforce the pressure plate 7 longitudinally. The stiffeners are arranged in an array along the center of the pressure plate 7, so that the pressure plate 7 will not deform greatly when subjected to longitudinal pressure. Combination Figures 1 to 14 As shown, and please refer to the following: Figure 4 , Figures 8 to 11The bottom of the pressure plate 7 has an installation cavity that communicates with the vent hole on the connecting column 8. A fixed plug 17 is tightly fitted inside the installation cavity. The upper end face of the fixed plug 17 has a receiving cavity 21, and the bottom of the fixed plug 17 has multiple vent grooves 26. The vent grooves 26 are in a through state with the receiving cavity 21. A movable plug 22 is fitted inside the receiving cavity 21. The periphery of the movable plug 22 is in sliding fit with the inner wall of the receiving cavity 21. A sealing part 25 is fixed to the downward-facing end face of the movable plug 22. The sealing part 25 is adapted to the vent groove 26, so that when the movable plug 22 is engaged in the receiving cavity 21 and the lower end face of the movable plug 22 abuts against the bottom wall of the inner cavity 21, the sealing part 25 can engage in the vent groove 26 and seal the vent groove 26. At the same time, the lower surface of the sealing part 25 and the fixed plug 17 The lower end face and the lower surface of the pressure plate 7 are flush. The periphery of the movable plug 22 is provided with multiple notch-shaped communication ports 24. The fixed plug 17 is coaxially fixed to the connecting rod 19. The end face of the movable plug 22 is provided with a through hole for the connecting rod 19 to pass through freely. The hole wall is keyed to the periphery of the connecting rod 19, so that the movable plug 22 will not rotate around the connecting rod 19. In addition, the upper end of the connecting rod 19 is fixedly fitted with a stop ring 20. The stop ring 20 is located above the movable plug 22. A spring 23 is wrapped around the periphery of the connecting rod 19. The two ends of the spring 23 elastically abut against the movable plug 22 and the stop ring 20 respectively. Under normal conditions, the spring 23 has an elastic abutting force on the movable plug 22, so that the lower end face of the movable plug 22 abuts against the bottom wall of the inner cavity of the receiving cavity 21. Combination Figures 4 to 14 As shown, and please refer to the following: Figure 13 and Figure 14A gear 13 is fixedly fitted around the periphery of the rotating part 14. A fixed arm 11 is fixedly fitted onto the upper end of the connecting column 8. A hollow cylinder 16 is horizontally mounted on the fixed arm 11. One end of the hollow cylinder 16 is closed, and the other end is open. A perforated part 29 is fixedly installed on the open side of the hollow cylinder 16. An air pipe is installed at the closed end of the hollow cylinder 16. The end of the air pipe away from the hollow cylinder 16 is installed on the periphery of the connecting column 8 and communicates with the vent hole on the connecting column 8. The inner cavity of the hollow cylinder 16 is coaxially engaged. A sliding plug 27 is provided, which can slide freely horizontally within the inner cavity of the hollow cylinder 16. An air storage cavity is formed between the sliding plug 27 and the inner cavity wall on the closed end side of the hollow cylinder 16. A drive rod 28 is coaxially fixed to the end face of the sliding plug 27. The drive rod 28 extends out of the hollow portion 29 and slides freely on the hollow portion 29. The periphery of the drive rod 28 and the hollow portion 29 form a key connection, so that the drive rod 28 will not rotate along its own circumference. A connecting rod is fixedly sleeved at the end of the drive rod 28 that extends out of the hollow cylinder 16. The connecting arm 12 has a rack 15 horizontally fixed to its upper end. The rack 15 and gear 13 are in a meshing transmission state. When the air pressure in the air storage chamber changes, the sliding plug 27 will be pushed, causing the sliding plug 27 to drive the drive rod 28 to move outward toward the open side of the hollow cylinder 16. This causes the drive rod 28 to drive the connecting arm 12 to move. When the connecting arm 12 moves, the rack 15 and gear 13 will mesh, driving the gear 13 to rotate. When the gear 13 rotates, the threaded part 18 will engage with the threaded hole. Through the force of the thread engagement, the threaded part 18 will move longitudinally relative to the rotating part 14, thereby allowing the longitudinal distance between the rotating part 14 and the connecting column 8 to be adjusted. In addition, the axial thickness of the gear 13 is greater than the longitudinal length of the rack 15. This ensures that even when the connecting column 8 and the rotating part 14 move away from each other, the rack 15 and gear 13 will still be in a meshing transmission state, and the two will not disengage.

[0020] Working principle of the invention: The mold base 5 containing lightweight concrete raw materials is placed on top of the base 4 and fixed to the base 4 with bolts, so that the mold base 5 and the base 4 are in a relatively static state. The hydraulic cylinder 10 is activated, the telescopic rod of the hydraulic cylinder 10 extends, and drives the rotating part 14, the connecting column 8 and the pressure plate 7 to move downward. When the pressure plate 7 moves downward, it will be inserted into the inner cavity of the mold base 5. After the pressure plate 7 moves downward, there is a certain longitudinal distance between the lower surface of the pressure plate 7 and the upper surface of the raw materials in the mold base 5 (the longitudinal distance is generally set within 2-3 cm). That is, the two are not in contact in the initial state. The vibration motor 3 is activated, and the vibration motor 3 works and vibrates the base 4. Under the action of vibration force, the raw materials in the inner cavity of the mold base 5 will be compacted, making the raw materials more compact, and most of the air in the raw materials will be discharged. When the mold base 5 is vibrated, it will reciprocate up and down. During this reciprocating motion, the raw material will also move up and down synchronously with the mold base 5. Since the pressure plate 7 is fixed, the raw material can move relative to the pressure plate 7. When the mold base 5 moves upward, the air that was previously discharged between the pressure plate 7 and the raw material through vibration is compressed, thus generating a pushing force on the sealing part 25, causing the sealing part 25 to move upward until it disengages from the vent groove 26. This allows the air to enter the receiving cavity 21 through the vent groove 26, and then enter the vent hole of the connecting column 8 through the connecting port 24 on the periphery of the movable plug part 22. This ensures that the air squeezed out of the raw material during each vibration and up-and-down movement is discharged, preventing air from re-entering the raw material. Furthermore, since the air in the raw material inside the mold base 5 does not come into contact with the outside air, and the air pressure inside the mold base 5 gradually decreases as the air is discharged, it effectively generates pressure within the mold base 5. The negative pressure allows air in the raw material to quickly enter between the raw material and the pressure plate 7, ensuring that most of the air is expelled from the raw material even with a short compaction time. When the mold base 5 moves down, the space between the pressure plate 7 and the raw material increases. At the same time, the spring 23 has a downward elastic resisting force on the movable plug 22, causing the movable plug 22 to move downward and the sealing part 25 to engage in the vent groove 26. This prevents outside air from entering the inner cavity of the mold base 5 through the vent groove 26. As a result, when the mold base 5 moves down, the air pressure in the space between the pressure plate 7 and the raw material decreases, which promotes the entry of air in the raw material into this space and improves the exhaust effect. In addition, after the sealing part 25 engages in the vent groove 26, the lower surface of the sealing part 25, the lower surface of the fixed plug 17, and the lower surface of the pressure plate 7 are flush. This prevents the raw material from developing depressions or protrusions or other appearance defects when it comes into contact with the lower surface of the pressure plate 7. During the compaction process, especially in the early stages, air in the raw material is expelled and the material becomes more compact, inevitably causing the material's accumulation height within the mold base 5 to gradually decrease. Of course, in the middle and later stages of the compaction process, the decrease in material height is negligible. Because the material's accumulation height decreases in the early stages of compaction, while the pressure plate 7 is in a fixed position, the longitudinal distance between the pressure plate 7 and the raw material increases. This may cause air in the raw material to fill the space between the raw material and the pressure plate 7 when the mold base 5 moves upward, preventing proper sealing of the sealing part 25. Effective thrust; therefore, in this embodiment, the air discharged into the vent hole will be compressed and transported into the hollow cylinder 16, generating thrust on the sliding plug 27. This causes the sliding plug 27 to drive the drive rod 28 to move outward toward the open side of the hollow cylinder 16, thereby causing the drive rod 28 to drive the connecting arm 12 to move. When the connecting arm 12 moves, it will cause the rack 15 and the gear 13 to mesh and drive the gear 13 to rotate. When the gear 13 rotates, it will cause the threaded part 18 to engage with the threaded hole. Through the force of the thread engagement, the threaded part 18 will generate relative rotation with the rotating part 14. The longitudinal movement of the rotating part 14 allows adjustment of the longitudinal distance between the rotating part 14 and the connecting column 8. Specifically, the rotating part 14 drives the connecting column 8 downwards, causing the pressure plate 7 to change position downwards. This reduces or maintains the longitudinal distance between the pressure plate 7 and the raw material within a certain range. Furthermore, as the mold base 5 moves downwards, the distance between the raw material and the pressure plate 7 increases, resulting in a decrease in air pressure. Therefore, the sealing part 25 engages within the vent groove 26, preventing air from flowing back into the mold base 5 from the hollow cylinder 16. Additionally, when the threaded part 18 and the threaded hole engage, The thread has self-locking properties, so when the mold base 5 moves upward, the pressure plate 7 will not retract. In addition, if the air pressure entering the hollow cylinder 16 is insufficient to drive the sliding plug 27 to move when the mold base 5 moves upward and approaches the pressure plate 7, and to make the gear 13 and rack 15 mesh to drive the pressure plate 7 downward, during the downward movement of the mold base 5, the pressure plate 7 will experience less resistance to downward movement. The air in the hollow cylinder 16 will push the sliding plug 27 to move, and make the gear 13 and rack 15 mesh, thereby driving the pressure plate 7 to move downward, thus adjusting the longitudinal distance between the pressure plate 7 and the raw material.

[0021] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A device for preparing hydrophobic lightweight concrete, comprising a base (1), a pedestal (4), a mold base (5) and a vibrating mechanism, characterized in that, Also include: The pressing plate (7) is provided above the mold base (5), a hydraulic cylinder (10) drives the pressing plate (7) to lift, and a height adjusting mechanism is connected between the hydraulic cylinder (10) and the pressing plate (7); The pressing plate (7) is provided with an exhaust passage, the exhaust passage has an air inlet at the bottom of the pressing plate (7), the air inlet is provided with a one-way valve structure, the one-way valve structure is configured to open to allow gas to enter the exhaust passage when the air pressure above the raw material in the mold base (5) increases, and close to block the backflow of gas when the air pressure decreases; The height adjusting mechanism is communicated with the exhaust passage, and is configured to drive the pressing plate (7) to descend relative to the hydraulic cylinder (10) by using the gas pressure entering the exhaust passage, so as to reduce the distance between the pressing plate (7) and the upper surface of the raw material.

2. A device for preparing a hydrophobic lightweight concrete according to claim 1, characterized in that The one-way valve structure includes a fixed plug portion (17) fixed to the bottom of the pressing plate (7), a movable plug portion (22) movably arranged in the fixed plug portion (17), and a spring (23) abutting against the movable plug portion (22); The bottom of the fixed plug portion (17) is provided with a gas permeation groove (26) communicated with the exhaust passage, the movable plug portion (22) is provided with a sealing portion (25), and the spring (23) abuts against the movable plug portion (22) to the position of the sealing portion (25) blocking the gas permeation groove (26) in normal state.

3. A device for preparing a hydrophobic lightweight concrete according to claim 2, characterized in that The periphery of the movable plug portion (22) is provided with a communication port (24), when the sealing portion (25) is separated from the gas permeation groove (26), the gas enters the exhaust passage through the gas permeation groove (26) and the communication port (24).

4. The device for preparing a hydrophobic lightweight concrete according to claim 2, characterized in that, When the sealing portion (25) blocks the gas permeation groove (26), the lower surface of the sealing portion (25), the lower surface of the fixed plug portion (17) and the lower surface of the pressing plate (7) are flush.

5. A device for preparing a hydrophobic lightweight concrete according to claim 4, characterized in that The height adjusting mechanism includes a rotating portion (14) rotatably connected to the telescopic rod end of the hydraulic cylinder (10), a connecting column (8) threadedly connected with the rotating portion (14), and a gear (13) rack assembly for driving the connecting column (8) to rotate relative to the rotating portion (14); The lower end of the connecting column (8) is connected with the pressing plate (7), and the upper end is communicated with the exhaust passage.

6. A device for preparing a hydrophobic lightweight concrete according to claim 5, characterized in that The gear (13) rack assembly includes a gear (13) fixedly sleeved on the periphery of the rotating portion (14), a fixed arm (11) fixedly sleeved on the connecting column (8), a hollow cylinder (16) fixedly connected to the fixed arm (11), a sliding plug (27) slidingly arranged in the hollow cylinder (16), and a rack rod (15) connected with the sliding plug (27); One end of the hollow cylinder (16) is communicated with the exhaust passage through an air pipe, the rack rod (15) is engaged with the gear (13), when the gas enters the hollow cylinder (16) to push the sliding plug (27) to move, the rack rod (15) drives the gear (13) to rotate.

7. The apparatus for preparing a hydrophobic lightweight concrete according to claim 5, wherein The upper end of the connecting column (8) is coaxially fixed with a threaded part (18), the lower end of the rotating part (14) is provided with a threaded hole, and the threaded part (18) is in threaded cooperation with the threaded hole.

8. The apparatus for preparing a hydrophobic lightweight concrete according to claim 5, wherein The axial thickness dimension of the gear (13) is greater than the longitudinal length dimension of the rack rod (15).

9. The device for preparing a hydrophobic lightweight concrete according to claim 1, characterized in that, The upper end of the connecting column (8) is coaxially fixed with a threaded part (18), the lower end of the rotating part (14) is provided with a threaded hole, and the threaded part (18) is in threaded cooperation with the threaded hole.

10. A process for the preparation of hydrophobic lightweight concrete, applied to the preparation apparatus according to any one of claims 1 to 9, characterized in that, The method comprises the following steps: Step one: the lightweight concrete raw materials are loaded into the mold base (5), and the mold base (5) is fixed on the base (4); Step two: the hydraulic cylinder (10) is started, the pressing plate (7) is driven to descend into the mold base (5), and the bottom surface of the pressing plate (7) and the upper surface of the raw materials are kept at a preset interval; Step three: the vibration motor (3) is started, the mold base (5) and the internal raw materials are driven to reciprocatingly vibrate up and down; Step four: in the vibration process, the one-way valve structure on the pressing plate (7) is opened by using the air pressure generated when the raw materials move upward, the gas in the raw materials is discharged into the exhaust passage; At the same time, the gas pressure in the exhaust passage is used to drive the height adjusting mechanism, so that the pressing plate (7) is automatically lowered relative to the hydraulic cylinder (10), the raw materials are continuously vibrated and compacted, and the gas is discharged, until the preparation is completed.

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