Concrete pump conveying cylinder filling rate test experiment platform and test method thereof

Abstract

The invention discloses a concrete pump conveying cylinder filling rate test experiment platform and a test method thereof. The platform comprises a hydraulic station, a control system of the hydraulic station, a displacement sensor, a hydraulic sensor, an oil pipe, a concrete suction device, a cylinder cover, a sealing gasket, a measuring cylinder, a hopper, a movable support of the hopper, a high-speed camera and a vibration table. The hydraulic station controls an oil cylinder piston to move through a throttling electromagnetic valve, and a concrete piston is driven to achieve material suction and material pumping. The concrete cylinder is made of a transparent material during natural filling rate testing, observation is facilitated, and the concrete cylinder is made of a steel material during pressure filling rate testing. The testing method comprises the steps of preparation before an experiment, natural suction filling rate testing and pressure filling rate testing, and the natural filling rate and the pressure filling rate are calculated through displacement and pressure monitoring, high-speed camera shooting recording and measuring cylinder measurement. The filling rate can be accurately tested, the relevance between the filling rate and the pumping pulse is revealed, the visualization and controllability of the testing process are improved, and the method is suitable for testing of various working conditions.

Description

Technical Field

[0001] The invention belongs to the technical field of concrete equipment testing, and relates to a concrete pump delivery cylinder filling rate testing experimental platform and a testing method thereof. Background Art

[0002] As an efficient and reliable way to deliver concrete, concrete pumping technology has been widely used in the field of modern engineering construction, including construction engineering, foundation engineering, water conservancy engineering, road engineering, municipal engineering and other aspects. Through concrete pumping technology, the concrete produced by the mixing station can be quickly and continuously delivered to the construction site, which not only significantly improves the construction efficiency, but also reduces the risk of manual operation, making the entire construction process safer and more controllable. With the increasing demand for efficient construction and high-quality concrete in the construction industry, the importance of concrete pumping technology in practical applications has become increasingly prominent. However, in the process of concrete pumping, the problem of pumping pulses has always been one of the key factors affecting its performance and stability, and the generation of pumping pulses is closely related to the filling rate of the concrete pump delivery cylinder.

[0003] During concrete pumping, the filling rate of the concrete cylinder directly determines the efficiency and stability of suction and pumping. The filling rate refers to the ratio of the actual volume of concrete filled in the concrete cylinder to its theoretical maximum volume during the suction process. Studies have shown that during the suction process of the concrete cylinder, due to the combined influence of the rheological properties of concrete (such as viscosity, fluidity, water-cement ratio, etc.) and the working characteristics of the pumping equipment itself (such as piston movement speed, suction port design, etc.), the filling rate is often difficult to reach the ideal state. Specifically, the suction process of concrete may lead to low or unstable filling rate due to factors such as uneven distribution of material particles, bubble mixing or suction resistance. This change in filling rate not only affects the pumping efficiency, but also causes obvious pressure fluctuations when the piston reciprocates, the so-called pumping pulse. The existence of pumping pulses may cause pipeline vibration, discontinuous delivery, and even have an adverse effect on construction quality. Therefore, in-depth research on the changing law of concrete cylinder filling rate and its influence on pumping pulse is of great significance for optimizing the structural design of concrete pumping equipment and improving pumping performance.

[0004] At present, the research on concrete pumping technology at home and abroad mainly focuses on the optimization of the mechanical structure of pumping equipment, the improvement of hydraulic system and the design of concrete mix ratio. For example, by improving the control accuracy of the hydraulic system, the amplitude of the pumping pulse can be reduced to a certain extent; by adjusting the water-cement ratio and aggregate gradation of the concrete, its fluidity can be improved, thereby indirectly increasing the filling rate. However, there is still a lack of systematic experimental platforms and methods for the direct testing and quantitative analysis of the core parameter of the concrete cylinder filling rate. Traditional testing methods mostly rely on theoretical calculations or indirect measurements, such as calculating the filling rate by the ratio of the pumping flow rate to the theoretical flow rate, but this method cannot accurately reflect the actual filling state of concrete during the suction process, especially the difference between natural suction and pressure filling. In addition, there is also a lack of observation methods for the law of air mixing during the filling rate change in existing research, which makes it impossible to fully reveal the intrinsic relationship between the filling rate and the pumping pulse.

[0005] In view of the testing requirements of natural suction filling rate and pressure filling rate, there is no experimental platform in the prior art that can meet both test conditions at the same time. The natural suction filling rate mainly reflects the filling degree of concrete in the absence of external pressure, relying on its own fluidity and the suction of the suction device; while the pressure filling rate involves the state of concrete being forced to be filled into the concrete cylinder under a specific hydraulic pressure. Due to the different mechanisms of the two filling methods, their effects on pumping pulses are also significantly different. For example, during the natural suction process, air may be mixed into the concrete in the form of large bubbles, while during pressure filling, air may be evenly distributed in the form of tiny bubbles, thereby affecting the density and pumping stability of the concrete. However, most of the current experimental equipment can only simulate a single working condition, making it difficult to achieve multi-dimensional measurement and comparative analysis of the filling rate. In addition, the existing equipment also has deficiencies in observation methods, such as the lack of intuitive recording tools such as high-speed cameras, which cannot capture the changes in the state of concrete during the suction process in real time. These technical gaps limit the in-depth study of the filling rate characteristics of the concrete cylinder and its correlation with pumping pulses, and also hinder the effective solution of related problems. Summary of the invention

[0006] In view of this, the present invention provides a concrete pump delivery cylinder filling rate test experimental platform and a test method thereof, the experimental platform can realize the accurate test of the natural suction filling rate and pressure filling rate of the concrete cylinder, and comprehensively monitor the test process through a variety of sensors and high-speed cameras, thereby providing reliable experimental support for studying the concrete pumping pulse characteristics.

[0007] In order to achieve the above object, the present invention provides the following technical solutions:

[0008] A concrete pump delivery cylinder filling rate test experimental platform, including a hydraulic station, a control system, a concrete suction device, a cylinder cover, a sealing pad, a hopper, and a movable bracket;

[0009] The concrete suction device comprises an oil cylinder, a water washing tank, a concrete cylinder, an oil cylinder piston, a piston rod, a connecting shaft, a concrete piston, and a fixed base; the oil cylinder and the concrete cylinder are connected via a water washing tank, and the water washing tank and the concrete cylinder are conductive, and are used to clean the concrete cylinder after testing; the piston rod is slidably arranged in the oil cylinder through the oil cylinder piston, and the concrete piston is slidably arranged in the concrete cylinder, one end of the connecting shaft passes through the water washing tank and is connected to the concrete piston, and the other end is connected to the piston rod;

[0010] The oil cylinder is connected to the hydraulic station through an oil pipe. A displacement sensor and a hydraulic sensor are provided on the oil cylinder. Both the displacement sensor and the hydraulic sensor are connected to the control system to obtain the displacement and hydraulic pressure information of the piston rod in the oil cylinder and control the movement of the piston rod.

[0011] The concrete cylinder is provided with a suction port at one end away from the oil cylinder, and a detachable cylinder cover is provided on the suction port, and the cylinder cover seals the suction port through a sealing gasket; the hopper is provided on a movable bracket, and the hopper is used to hold concrete. The hopper is provided with a hopper opening, and the hopper opening can be docked with the suction port by moving the movable bracket;

[0012] The control system controls the piston rod to drive the concrete piston to move, thereby achieving material suction and pumping of the concrete cylinder.

[0013] Furthermore, the experimental platform also includes a measuring cylinder and a vibration table. The measuring cylinder is used to receive concrete pumped out of the concrete cylinder, and the vibration table is used to vibrate and discharge the air in the concrete in the measuring cylinder.

[0014] Furthermore, the experimental platform also includes a high-speed camera, which is used to record the material suction and pumping processes.

[0015] Furthermore, the concrete cylinder is made of transparent material when testing the natural filling rate, and is made of a common steel concrete cylinder when testing the pressure filling rate.

[0016] Furthermore, the hydraulic station includes an oil pump, a throttling solenoid valve, an oil tank, a relief valve, and a pressure gauge; the oil pump on the oil tank is connected to the oil cylinder through an oil pipe, and the throttling solenoid valve controls the forward and backward movement of the oil cylinder piston in the oil cylinder, and then drives the concrete piston in the concrete cylinder through the connecting shaft to realize concrete suction and pumping.

[0017] A concrete pump delivery cylinder filling rate test method based on the above experimental platform includes pre-experimental preparation and requirements, a natural suction filling rate test method and a pressure filling rate test method, wherein:

[0018] Pre-experimental preparation and requirements include the following steps:

[0019] (1) Select the concrete cylinder material according to the experiment type. Transparent material is used for natural filling rate test and steel material is used for pressure filling rate test.

[0020] (2) Determine the diameter of the concrete cylinder and select a matching concrete piston;

[0021] (3) Connect the concrete cylinder and the water washing tank, connect the concrete piston to the connecting shaft, and assemble the experimental platform;

[0022] (4) Extend the suction port completely into the hopper opening to fully wet the concrete cylinder and hopper;

[0023] (5) Turn on the hydraulic station, adjust the overflow valve to set the maximum hydraulic oil pressure P, control the throttle solenoid valve to inject hydraulic oil into the rear of the cylinder, and push the cylinder piston forward to the initial position. At this time, the concrete piston is at the suction port position;

[0024] (6) Seal the concrete cylinder with a cylinder cover and a sealing gasket to prevent concrete from entering the concrete cylinder prematurely;

[0025] (7) Load concrete into the hopper in an amount that ensures that the lowest position of the concrete after suction is higher than the highest point of the hopper opening, and that the loading amount is the same at different water-cement ratios;

[0026] The natural inhalation fill rate test method includes the following steps:

[0027] (1) The control system adjusts the throttling solenoid valve and the displacement sensor to set the stroke of the cylinder piston and calculate the theoretical maximum filling volume V0 of the concrete cylinder;

[0028] (2) After loading is completed, open the cylinder cover and gasket;

[0029] (3) Turn on the data acquisition system of the displacement sensor and hydraulic sensor to monitor the displacement changes of the cylinder piston and the hydraulic oil pressure changes;

[0030] (4) Turn on the high-speed camera to monitor the suction process of the concrete cylinder and the changes in the concrete state and bubbles during the suction process;

[0031] (5) Control the throttle solenoid valve to inject hydraulic oil into the front part of the cylinder, push the cylinder piston back to the predetermined stroke position, and complete the material suction;

[0032] (6) After the suction is completed, the concrete cylinder is closed with the cylinder cover and the sealing gasket, and then the hopper is removed;

[0033] (7) Place the measuring cylinder below the suction port;

[0034] (8) Open the cylinder head and gasket;

[0035] (9) Turn on the high-speed camera to monitor the changes of concrete and bubbles in the concrete cylinder during the pumping process and the state and volume changes of the concrete pumped into the measuring cylinder;

[0036] (10) Controlling the throttling solenoid valve to inject hydraulic oil into the rear of the oil cylinder, pumping out the concrete in the concrete cylinder until the concrete piston moves to the suction port position; the pumping process is monitored by a high-speed camera to monitor the changes of concrete and bubbles in the concrete cylinder and the state and volume changes of the concrete pumped into the measuring cylinder;

[0037] (11) Start the vibration table and fully vibrate the concrete pumped into the measuring cylinder to a volume V1 without the presence of large-sized air;

[0038] (12) Calculate the natural suction filling rate of the concrete cylinder under the natural suction mode for concrete with the same piston stroke and the same rheological properties

[0039] The pressure fill rate test method includes the following steps:

[0040] (1) The theoretical maximum stroke L0 of the cylinder piston is set by adjusting the throttle solenoid valve and displacement sensor through the control system;

[0041] (2) After loading is completed, open the cylinder cover and gasket;

[0042] (3) Turn on the data acquisition system of the displacement sensor and hydraulic sensor to monitor the displacement changes of the cylinder piston and the hydraulic oil pressure changes;

[0043] (4) Control the throttle solenoid valve to inject hydraulic oil into the front of the cylinder, push the cylinder piston back to the predetermined stroke position, and complete the material suction;

[0044] (5) After the suction is completed, close the concrete cylinder with the cylinder cover and sealing gasket and remove the hopper;

[0045] (6) Control the throttle solenoid valve to inject hydraulic oil into the rear of the cylinder, pushing the cylinder piston forward. When the hydraulic sensor detects that the pressure reaches the maximum value P, the forward distance is recorded as ΔL, and the oil injection is stopped;

[0046] (7) Place the measuring cylinder below the suction port;

[0047] (8) Open the cylinder head and gasket;

[0048] (9) Turn on the high-speed camera to monitor the changing state of the concrete material and the internal bubbles in the concrete cylinder during the pumping process, the falling state of the concrete material from the concrete cylinder to the measuring cylinder, and the volume change of the pumped concrete material;

[0049] (10) Control the throttle solenoid valve to inject hydraulic oil into the rear of the cylinder, gradually pumping out the concrete sucked into the concrete cylinder until the concrete is completely pumped out and the concrete piston moves to the suction port position.

[0050] (11) Calculate the pressure filling rate of concrete under natural suction mode at different pressures P for concrete with the same piston stroke and the same rheological properties.

[0051] Furthermore, in the pressure filling rate test, different hydraulic oil pressures P were set by adjusting the relief valve, and the filling rate changes under different pressures were recorded.

[0052] Furthermore, by replacing concrete cylinders with different cylinder diameters and concrete with different rheological properties, the test was repeated to analyze the changing pattern of the filling rate.

[0053] Furthermore, by comparing the monitoring data of the displacement sensor and the hydraulic sensor and the records of the high-speed camera, the air mixing pattern during the suction process and its influence on the filling rate were analyzed.

[0054] The beneficial effects of the present invention are:

[0055] 1. The present invention designs a set of experimental platforms that integrate natural suction filling rate and pressure filling rate tests, which can simulate the filling process of concrete under no external pressure and specific pressure, respectively, filling the gap in the existing technology that lacks systematic filling rate testing methods. The test method combines measurement tools such as displacement sensors, hydraulic sensors and measuring cylinders to accurately calculate the filling rate value, providing reliable data support for studying the filling characteristics of concrete during pumping.

[0056] 2. The experimental platform of the present invention uses a transparent concrete cylinder (for natural filling rate testing) and a high-speed camera, which can record the state changes of concrete and the distribution of bubbles during the suction process in real time, and intuitively reveal the law of air mixing. This visual design overcomes the limitation that traditional indirect measurement methods cannot accurately reflect the filling state. At the same time, the hydraulic station and its control system accurately adjust the piston stroke and hydraulic pressure through the throttling solenoid valve and the overflow valve, making the test conditions more controllable and the experimental results more repeatable and scientific.

[0057] 3. The present invention can systematically study the influence of filling rate on pumping pulse by comparing the changing rules of filling rate under different cylinder diameters, different hydraulic pressures and different concrete rheological properties, and combining the displacement and pressure data analysis during the suction and pumping process. This provides a theoretical basis and technical guidance for solving the pulse problem caused by insufficient filling rate during the pumping process, and helps to optimize the performance of concrete pumping equipment.

[0058] 4. The present invention provides an experimental basis for the structural design of concrete pumping equipment, improvement of hydraulic system and optimization of concrete mix ratio by providing a scientific filling rate test method. The research results can effectively reduce pipeline vibration and discontinuous delivery problems caused by pumping pulses, improve construction efficiency and concrete pouring quality, and thus promote the further development of concrete pumping technology in the field of construction engineering.

[0059] Other advantages, objectives and features of the present invention will be described in the following description to some extent, and to some extent, will be obvious to those skilled in the art based on the following examination and study, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be described in detail below in conjunction with the accompanying drawings, wherein:

[0061] Figure 1 Schematic diagram of a concrete pump delivery cylinder filling rate test platform in an embodiment of the present invention.

[0062] Figure 2 for Figure 1 Schematic diagram of the hydraulic station and control system.

[0063] Figure 3 for Figure 1 Schematic diagram of the concrete suction device.

[0064] Figure 4 for Figure 1 Schematic diagram of the middle hopper and movable bracket.

[0065] Figure numerals: 1-hydraulic station and its control system; 2-displacement sensor; 3-hydraulic sensor; 4-oil pipe; 5-concrete suction device; 6-cylinder head; 7-sealing gasket; 8-measuring cylinder; 9-hopper and its movable bracket; 10-high-speed camera; 11-vibrating table; 101-oil pump; 102-throttling solenoid valve; 103-oil tank; 104-overflow valve; 105-pressure gauge; 501-oil cylinder; 502-water washing tank; 503-concrete cylinder; 504-oil cylinder piston; 505-piston rod; 506-connecting shaft; 507-concrete piston; 508-fixed base; 509-suction port; 510-oil filling port; 511-oil filling port; 901-hopper; 902-hopper opening; 903-bracket; 904-pulley. DETAILED DESCRIPTION

[0066] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner, and the following embodiments and features in the embodiments can be combined with each other without conflict.

[0067] Among them, the drawings are only used for illustrative explanations, and they only represent schematic diagrams rather than actual pictures, and should not be understood as limitations on the present invention. In order to better illustrate the embodiments of the present invention, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of actual products. For those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0068] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right", "front", "rear", etc. indicate the orientation or position relationship, they are based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only used for illustrative purposes and cannot be understood as limiting the present invention. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0069] like Figure 1 As shown, a concrete pump delivery cylinder filling rate test experimental platform provided by the present invention mainly includes a hydraulic station and its control system 1, a displacement sensor 2, a hydraulic sensor 3, an oil pipe 4, a concrete suction device 5, a cylinder cover 6, a sealing gasket 7, a measuring cylinder 8, a hopper and its movable bracket 9, a high-speed camera 10, and a vibration table 11.

[0070] like Figure 2 As shown, the hydraulic station and its control system 1 include an oil pump 101, a throttle solenoid valve 102, an oil tank 103, a relief valve 104, a pressure gauge 105, etc. The hydraulic station and its control system 1 are connected to the concrete suction device 5 through an oil pipe 4, and the hydraulic oil is injected into the front or rear oil pipe 4 through the automatic control of the throttle solenoid valve 102 to control the forward and backward movement of the oil cylinder piston 504 in the oil cylinder 501, and then the concrete piston 507 in the concrete cylinder 503 is driven through the connecting shaft 506 to realize concrete suction and pumping.

[0071] like Figure 3As shown, the concrete suction device 5 is provided with a displacement sensor 2, a hydraulic sensor 3, an oil cylinder 501, a water washing tank 502, a concrete cylinder 503, an oil cylinder piston 504, a piston rod 505, a connecting shaft 506, a concrete piston 507, a fixed base 508, a suction port 509, an oil filling port 510 and an oil filling port 511. The function of the water washing tank 502 is to connect the oil cylinder 501 and the concrete cylinder 503, and the connection method is usually bolt connection, which ensures that the connection is stable and easy to disassemble. Among them, the concrete cylinder 503 is made of transparent material during the natural filling rate test, and the suction process and the concrete state can be observed and recorded through the concrete cylinder; the commonly used ordinary steel concrete cylinder is used during the pressure filling rate measurement.

[0072] like Figure 4 As shown, the hopper and its movable bracket 9 include a hopper 901, a hopper opening 902 for the concrete cylinder 503 to extend into, a bracket 903, and a pulley 904. The design of the pulley 904 allows the hopper 901 to be easily moved away after the concrete cylinder 503 completes the material suction, so as to carry out the next step of the pumping experiment.

[0073] The cylinder cover 6 and the sealing gasket 7 are used for the experiment of measuring the pressure filling rate of the concrete cylinder; the measuring cylinder 8, the hopper and its movable bracket 9 and the high-speed camera 10 are used for the experiment of measuring the natural suction filling rate and the pressure filling rate of the concrete cylinder; the vibration table 11 is used for the experiment of measuring the suction filling rate.

[0074] The specific implementation plan and operation steps of the experiment are shown in 2. Experimental method for testing the filling rate of the concrete pump delivery cylinder.

[0075] Experimental method for testing the filling rate of concrete pump delivery cylinder

[0076] Preparation and requirements before the experiment:

[0077] (1) First, determine the type of experiment to be conducted (natural filling rate test experiment or pressure filling rate test experiment). In the natural filling rate test experiment, the concrete cylinder 503 is made of transparent material, usually acrylic material; in the pressure filling rate test, a common ordinary steel concrete cylinder is used.

[0078] (2) Determine the cylinder diameter of the concrete cylinder 503 required for the experiment and select a concrete piston 507 of appropriate size.

[0079] (3) Connect the concrete cylinder 503 and the water washing tank 502 respectively, connect the concrete piston 507 to the connecting shaft 506, and the concrete pump delivery cylinder filling rate test experimental platform is assembled. Figure 1 Status shown.

[0080] (4) The suction port 509 of the concrete cylinder 503 is completely extended into the hopper opening 902 to fully wet the concrete cylinder 503 and the hopper 901.

[0081] (5) Turn on the hydraulic station and adjust the overflow valve 104 to set the maximum value P of the hydraulic oil pressure; control the throttle solenoid valve 102 to allow the hydraulic oil to be injected into the rear part of the cylinder 501 from the oil filling port 511, pushing the cylinder piston 504 forward to the initial position. At this time, the concrete piston 507 is located at the suction port 509 of the concrete cylinder 503.

[0082] (6) The concrete cylinder is sealed with a cylinder cover 6 and a sealing gasket 7 to prevent the concrete material from entering the concrete cylinder in advance.

[0083] (7) Concrete material is loaded into the hopper 901. The loading amount must ensure that after the suction is completed, the lowest position of the concrete material is still higher than the highest point of the hopper opening 902, so as to ensure that the suction material is sufficient; in addition, the loading amount under different water-cement ratios must be the same to eliminate experimental errors as much as possible.

[0084] 2.1 Natural suction filling rate test method

[0085] (1) The control system adjusts the throttling solenoid valve 102 and the displacement sensor 2 to set the stroke of the cylinder piston 504, i.e., the suction stroke of the concrete cylinder 503, and calculates the theoretical maximum filling rate of the concrete cylinder according to the set stroke, i.e., the volume V0 of the concrete cylinder that the concrete cylinder can theoretically be filled with without the presence of large-sized air.

[0086] (2) After the loading is completed, the cylinder cover 6 and the sealing gasket 7 of the sealed concrete cylinder 503 are opened.

[0087] (3) Turn on the data acquisition system of the displacement sensor 2 and the hydraulic sensor 3 to monitor the displacement changes of the cylinder piston 504 and the pressure changes of the hydraulic oil during the experiment.

[0088] (4) Turn on the high-speed camera 10 to monitor the suction process of the concrete cylinder 503 and the changing state of the concrete material and internal bubbles in the concrete cylinder 503.

[0089] (5) Control the throttle solenoid valve 102 to allow the hydraulic oil to be injected into the front of the cylinder 501 from the oil filling port 510, start sucking the material, and gradually push the cylinder piston 504 back to a predetermined stroke position.

[0090] (6) After the suction is completed, the concrete cylinder 503 is closed using the cylinder cover 6 and the sealing gasket 7, and then the hopper and its movable bracket 9 are removed.

[0091] (7) Place the measuring cylinder 8 below the suction port 509 of the concrete cylinder 503.

[0092] (8) The cylinder cover 6 and the sealing gasket 7 for sealing the concrete cylinder 503 are opened.

[0093] (9) Turn on the high-speed camera 10 to monitor the changing state of the concrete material and the internal bubbles in the concrete cylinder 503 during the pumping process, the falling state of the concrete material during the process of being pumped from the concrete cylinder 503 to the measuring cylinder 8, and the volume change of the pumped concrete material.

[0094] (10) The throttling solenoid valve 102 is controlled to allow hydraulic oil to be injected into the rear part of the oil cylinder 501 from the oil filling port 511, and the concrete sucked into the concrete cylinder 503 is gradually pumped out until the concrete material is completely pumped out and the concrete piston 507 moves to the position of the suction port 509.

[0095] (11) Turn on the vibration table 11 and fully vibrate the concrete pumped into the measuring cylinder 8 until it reaches a volume V1 without the presence of large-sized air.

[0096] (12) Calculate the natural suction filling rate of the concrete cylinder under natural suction mode for concrete with the same piston stroke and the same rheological properties:

[0097] (13) The concrete cylinder 503 with different cylinder diameters can be replaced, the overflow valve 104 can be adjusted to set different hydraulic oil pressures, the stroke of the cylinder piston 504 can be adjusted, and concrete with different properties can be used to carry out natural suction filling rate tests of the concrete cylinder under different conditions.

[0098] (14) By comparing the displacement of the cylinder piston 504 monitored by the displacement sensor 2 during the suction and pumping process, the change in the hydraulic oil pressure monitored by the hydraulic sensor 3, and the state and volume of concrete suction and concrete pumping recorded by the high-speed camera 10, the distribution position of the air sucked into the concrete cylinder is analyzed, and the air mixing law during the suction process is obtained.

[0099] (15) The filling rate calculated by combining (14) with (12) is used to analyze the changing characteristics of the natural suction filling rate of the concrete cylinder and analyze its influence law.

[0100] 2.2 Pressure filling rate test method

[0101] (1) The throttling solenoid valve 102 and the displacement sensor 2 are adjusted by the control system to set the stroke of the cylinder piston 504 to be used, that is, the theoretical maximum stroke (L0) of the concrete cylinder 503.

[0102] (2) After the loading is completed, the cylinder cover 6 and the sealing gasket 7 of the sealed concrete cylinder 503 are opened.

[0103] (3) Turn on the data acquisition system of the displacement sensor 2 and the hydraulic sensor 3 to monitor the displacement changes of the cylinder piston 504 and the pressure changes of the hydraulic oil during the experiment.

[0104] (4) Control the throttle solenoid valve 102 to allow the hydraulic oil to be injected into the front of the cylinder 501 from the oil filling port 510, start sucking the material, and gradually push the cylinder piston 504 back to the predetermined stroke position.

[0105] (5) After the suction is completed, the concrete cylinder 503 is closed using the cylinder cover 6 and the sealing gasket 7, and then the hopper and its movable bracket 9 are removed.

[0106] (6) Control the throttle solenoid valve 102 to allow hydraulic oil to be injected into the rear of the cylinder 501 from the oil filling port 511, start to absorb material, gradually push the cylinder piston 504 forward, and make the concrete piston 507 push the concrete forward.

[0107] (7) When the hydraulic oil pressure collected by the hydraulic sensor 3 reaches the maximum value P of the set hydraulic station oil supply pressure, the concrete piston 507 starts to push the concrete forward until the pressure transmitter test value is P. The distance moved forward is ΔL, and the throttling solenoid valve 102 is controlled to stop injecting oil.

[0108] (8) Place the measuring cylinder 8 below the suction port 509 of the concrete cylinder 503.

[0109] (9) The cylinder cover 6 and the sealing gasket 7 for sealing the concrete cylinder 503 are opened.

[0110] (10) Turn on the high-speed camera 10 to monitor the changing state of the concrete material and the internal bubbles in the concrete cylinder 503 during the material pumping process, the falling state of the concrete material during the process of being pumped from the concrete cylinder 503 to the measuring cylinder 8, and the volume change of the pumped concrete material.

[0111] (11) The throttling solenoid valve 102 is controlled to allow hydraulic oil to be injected into the rear of the oil cylinder 501 from the oil filling port 511, and the concrete sucked into the concrete cylinder 503 is gradually pumped out until the concrete material is completely pumped out and the concrete piston 507 moves to the position of the suction port 509.

[0112] (12) Calculate the pressure filling rate of concrete under natural suction mode at different pressures P for concrete with the same piston stroke and the same rheological properties:

[0113] (13) The concrete cylinder 503 with different cylinder diameters can be replaced, the overflow valve 104 can be adjusted to set different hydraulic oil pressures, the stroke of the cylinder piston 504 can be adjusted, and concrete with different properties can be used to carry out natural suction filling rate tests of the concrete cylinder under different conditions.

[0114] (14) By comparing the displacement of the cylinder piston 504 monitored by the displacement sensor 2 during the suction and pumping process, the change in the hydraulic oil pressure monitored by the hydraulic sensor 3, and the state and volume of concrete suction and concrete pumping recorded by the high-speed camera 10, the distribution position of the air sucked into the concrete cylinder is analyzed, and the air mixing law during the suction process is obtained.

[0115] (15) The pressure filling rate calculated by combining (14) with (12) is used to analyze the changing characteristics of the concrete cylinder pressure filling rate and its influence law.

[0116] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution, which should be included in the scope of the claims of the present invention.

Claims

1. A concrete pump delivery cylinder filling rate test platform, characterized by: It includes hydraulic station, control system, concrete suction device, cylinder cover, sealing gasket, hopper and movable bracket; The concrete suction device comprises an oil cylinder, a water washing tank, a concrete cylinder, an oil cylinder piston, a piston rod, a connecting shaft, a concrete piston, and a fixed base; the oil cylinder and the concrete cylinder are connected via a water washing tank, and the water washing tank and the concrete cylinder are conductive, and are used to clean the concrete cylinder after testing; the piston rod is slidably arranged in the oil cylinder through the oil cylinder piston, and the concrete piston is slidably arranged in the concrete cylinder, one end of the connecting shaft passes through the water washing tank and is connected to the concrete piston, and the other end is connected to the piston rod; The oil cylinder is connected to the hydraulic station through an oil pipe. A displacement sensor and a hydraulic sensor are provided on the oil cylinder. Both the displacement sensor and the hydraulic sensor are connected to the control system to obtain the displacement and hydraulic pressure information of the piston rod in the oil cylinder and control the movement of the piston rod. The concrete cylinder is provided with a suction port at one end away from the oil cylinder, and a detachable cylinder cover is provided on the suction port, and the cylinder cover seals the suction port through a sealing gasket; the hopper is provided on a movable bracket, and the hopper is used to hold concrete. The hopper is provided with a hopper opening, and the hopper opening can be docked with the suction port by moving the movable bracket; The control system controls the piston rod to drive the concrete piston to move, thereby achieving material suction and pumping of the concrete cylinder.

2. The concrete pump delivery cylinder filling rate test platform according to claim 1 is characterized by: The experimental platform also includes a measuring cylinder and a vibration table. The measuring cylinder is used to receive concrete pumped out of the concrete cylinder, and the vibration table is used to vibrate and discharge the air in the concrete in the measuring cylinder.

3. The concrete pump delivery cylinder filling rate test platform according to claim 1 is characterized by: The experimental platform also includes a high-speed camera, which is used to record the material suction and pumping processes.

4. The concrete pump delivery cylinder filling rate test platform according to claim 1 is characterized by: The concrete cylinder is made of transparent material when testing the natural filling rate, and is made of a common steel concrete cylinder when testing the pressure filling rate.

5. The concrete pump delivery cylinder filling rate test platform according to claim 1 is characterized by: The hydraulic station includes an oil pump, a throttling solenoid valve, an oil tank, a relief valve, and a pressure gauge; the oil pump on the oil tank is connected to the oil cylinder through an oil pipe, and the throttling solenoid valve controls the forward and backward movement of the oil cylinder piston in the oil cylinder, and then drives the concrete piston in the concrete cylinder through the connecting shaft to realize concrete suction and pumping.

6. A method for testing the filling rate of a concrete pump delivery cylinder based on the experimental platform according to any one of claims 1 to 5, characterized in that: It includes pre-experimental preparation and requirements, natural inhalation filling rate test method and pressure filling rate test method, among which: Pre-experimental preparation and requirements include the following steps: (1) Select the concrete cylinder material according to the experiment type. Transparent material is used for natural filling rate test and steel material is used for pressure filling rate test. (2) Determine the diameter of the concrete cylinder and select a matching concrete piston; (3) Connect the concrete cylinder and the water washing tank, connect the concrete piston to the connecting shaft, and assemble the experimental platform; (4) Extend the suction port completely into the hopper opening to fully wet the concrete cylinder and hopper; (5) Turn on the hydraulic station, adjust the overflow valve to set the maximum hydraulic oil pressure P, control the throttle solenoid valve to inject hydraulic oil into the rear of the cylinder, and push the cylinder piston forward to the initial position. At this time, the concrete piston is at the suction port position; (6) Seal the concrete cylinder with a cylinder cover and a sealing gasket to prevent the concrete from entering the concrete cylinder prematurely; (7) Load concrete into the hopper in an amount that ensures that the lowest position of the concrete after suction is higher than the highest point of the hopper opening, and that the loading amount is the same for different water-cement ratios; The natural inhalation fill rate test method includes the following steps: (1) The control system adjusts the throttling solenoid valve and the displacement sensor to set the stroke of the cylinder piston and calculate the theoretical maximum filling volume V0 of the concrete cylinder; (2) After loading is completed, open the cylinder cover and gasket; (3) Turn on the data acquisition system of the displacement sensor and hydraulic sensor to monitor the displacement changes of the cylinder piston and the hydraulic oil pressure changes; (4) Turn on the high-speed camera to monitor the suction process of the concrete cylinder and the changes in the concrete state and bubbles during the suction process; (5) Control the throttle solenoid valve to inject hydraulic oil into the front part of the cylinder, push the cylinder piston back to the predetermined stroke position, and complete the material suction; (6) After the suction is completed, the concrete cylinder is closed with the cylinder cover and the sealing gasket, and then the hopper is removed; (7) Place the measuring cylinder below the suction port; (8) Open the cylinder head and gasket; (9) Turn on the high-speed camera to monitor the changes of concrete and bubbles in the concrete cylinder during the pumping process and the state and volume changes of the concrete pumped into the measuring cylinder; (10) Controlling the throttling solenoid valve to inject hydraulic oil into the rear of the oil cylinder, pumping out the concrete in the concrete cylinder until the concrete piston moves to the suction port position; the pumping process is monitored by a high-speed camera to monitor the changes of concrete and bubbles in the concrete cylinder and the state and volume changes of the concrete pumped into the measuring cylinder; (11) Start the vibration table and fully vibrate the concrete pumped into the measuring cylinder to a volume V1 without the presence of large-sized air; (12) Calculate the natural suction filling rate of the concrete cylinder under the natural suction mode for concrete with the same piston stroke and the same rheological properties The pressure fill rate test method includes the following steps: (1) The theoretical maximum stroke L0 of the cylinder piston is set by adjusting the throttle solenoid valve and displacement sensor through the control system; (2) After loading is completed, open the cylinder cover and gasket; (3) Turn on the data acquisition system of the displacement sensor and hydraulic sensor to monitor the displacement changes of the cylinder piston and the hydraulic oil pressure changes; (4) Control the throttle solenoid valve to inject hydraulic oil into the front of the cylinder, push the cylinder piston back to the predetermined stroke position, and complete the material suction; (5) After the suction is completed, close the concrete cylinder with the cylinder cover and sealing gasket and remove the hopper; (6) Control the throttle solenoid valve to inject hydraulic oil into the rear of the cylinder, pushing the cylinder piston forward. When the hydraulic sensor detects that the pressure reaches the maximum value P, the forward distance is recorded as ΔL, and the oil injection is stopped; (7) Place the measuring cylinder below the suction port; (8) Open the cylinder head and gasket; (9) Turn on the high-speed camera to monitor the changing state of the concrete material and the internal bubbles in the concrete cylinder during the pumping process, the falling state of the concrete material from the concrete cylinder to the measuring cylinder, and the volume change of the pumped concrete material; (10) Control the throttle solenoid valve to inject hydraulic oil into the rear of the cylinder, gradually pumping out the concrete sucked into the concrete cylinder until the concrete is completely pumped out and the concrete piston moves to the suction port position. (11) Calculate the pressure filling rate of concrete under natural suction mode at different pressures P for concrete with the same piston stroke and the same rheological properties.

7. The testing method according to claim 6, characterized in that: In the pressure filling rate test, different hydraulic oil pressures P are set by adjusting the relief valve, and the filling rate changes under different pressures are recorded.

8. The testing method according to claim 6, characterized in that: By replacing concrete cylinders with different cylinder diameters and concrete with different rheological properties, the test was repeated to analyze the changing pattern of the filling rate.

9. The testing method according to claim 6, characterized in that: By comparing the monitoring data of the displacement sensor and hydraulic sensor and the records of the high-speed camera, the air mixing pattern during the suction process and its influence on the filling rate are analyzed.

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