SM-615U vibration platform

Contents

CONTENTS

Introduction

1. Description and purpose of the specified process and justification of the production flow chart

1.1 Selection of production flow chart

1.2 Process Description and Purpose

1.3 Compaction of concrete mixture in the process flow diagram of production on the vibration platform

2. Device and structures of vibration platforms

2.1 Vibration platforms with circular harmonic oscillations

2.2 Vibration platforms with directed harmonic oscillations

2.3 Vibration hovercraft sites operating on the principle of vibration piston

2.4 Resonant vibration platforms with asymmetric oscillations

2.5 Impact and vibration platforms

3. Calculation of main parameters of SM-615U vibration platform

4. Safety and Health

5. Protection of the environment and nature

List of literature used

Introduction

The volume of production of various building materials, products and structures increases from year to year. Production of non-metallic materials, prefabricated reinforced concrete products and structures increases with a significant increase in their quality.

For the production of construction materials, machine-building plants produce a wide variety of machines and equipment, and along with the creation of new ones, there is a continuous change and improvement in the existing structures of machines and an overall increase in their output. The dimensional rows of the main machines are determined by the relevant GOST, developed on the basis of scientific research, studying the needs of the national economy and fully ensuring this need at the lowest dimensional costs of the machines, which gives a great economic effect, since it greatly simplifies the manufacture and improves the reliability of the machines, as well as facilitates their operation.

When creating machines and process lines, great attention is paid to improving the working conditions of maintenance personnel, ensuring the current sanitary standards for the permissible level of noise, vibration and dust.

The main goals and objectives of the construction industry are to improve the quality of finished products, increase the productivity of equipment, and reduce metal consumption.

The most efficient and promising way to solve these problems is to automate production processes.

Vibration forming equipment is intended for compaction of concrete mixture in molds during manufacture of concrete and reinforced concrete products. Under the influence of vibration, the concrete mixture acquires mobility, ensuring a good filling of the mold. Density of concrete mixture increases due to both more compact laying of aggregate particles and separation of air bubbles from mixture. With excessive long-term vibration, its stratification begins. Therefore, in addition to the vibration parameters, the duration of vibration must also be set.

In the production of prefabricated reinforced concrete, the method of bulk molding, which is carried out on machines called vibration sites, has become the most widespread. Vibration sites with vertically and horizontally directed oscillations became most widespread. In the first case, the concrete mixture is compacted when normal stresses occur in it, and in the second - tangents. Due to the higher efficiency of the vibration platform with vertically directed oscillations, more widespread than the vibration platform with horizontally directed oscillations. Machines with harmonious and asymmetric oscillations are used.

Description and purpose of the specified process and justification of the production flow chart

1.1 Selection of production flow chart

During the factory production of reinforced concrete products, three main production methods were widely found: aggregate-flow, conveyor and bench. A variety of bench method is cassette.

The aggregate-in-line production method consists in the fact that all the performed operations for the manufacture of the product: cleaning and lubrication of molds, laying of reinforcement - and concrete mixture, hardening and smelting, are carried out at special posts that form an in-line production line. The aggregate-flow method of organization of production is characterised by the possibility of fixation behind one production line of products different not only in size, but also in design. The main advantage of the flow-aggregate method of production is in the versatility of the main technological equipment, which allows, with little cost and time associated with the manufacture of only new forms, to switch to the production of a new type of products. Aggregate flow technology is characterized by great flexibility and maneuverability in the use of technological and transport equipment, in the mode of heat treatment, which is important when producing products of a large range.

The conveyor production method is a more advanced flow-aggregate technology and allows you to mechanize and automate the main technological operations as much as possible. In this method, the production line operates on the principle of a closed pulsating conveyor, when the product, being placed on a special tray, moves from post to post with a certain interval of time corresponding to the longest operation. The conveyor method often uses trays-wagons measuring 7.5X5.5 m, allowing the manufacture of products up to 7 m long and 5 m wide. The wagonetkipoddons on which the mold is assembled, using a special pusher at certain intervals (about 15 minutes), move along the conveyor line for production operations: cleaning and lubrication of the molds, laying reinforcement and concrete mixture, compacting the mixture, heat and moisture treatment and fracturing. The conveyor production method is economically feasible when producing the same type of products at high-capacity plants. The conveyor process has advantages with respect to the mechanization of work. At the same time, high capital costs, the difficulty of switching to the production of a new nomenclature and type of product, are a significant drawback of conveyor technology.

The bench method is characterized by low mechanization and automation of the process and high labor intensity in this regard. In the bench production method, the reinforced concrete product, being in stationary forms, remains in place throughout the production cycle, and the technological equipment for performing separate operations for laying reinforcement, concrete mixture and compaction moves sequentially from one mold to another. The stand is a reinforced concrete platform with a smooth surface. When concreting a reinforced concrete product of complex configuration, special matrices are installed on the stand - reinforced concrete forms, the bottoms of which reproduce the imprint of the ribbed product (stairways, etc.). Devices and pipes through which steam, hot water or oil is passed are put into the body of a reinforced concrete platform or dies for thermal moisture treatment of the product. The bench method gives a high economic effect when making reinforced concrete products of significant sizes - slabs, trusses and beams for industrial and transport construction.

1.2. Description and purpose of the process.

Aggregate-flow lines are equipped both in workshops and at landfills, the easiest to operate, meet the conditions of small-scale production at medium and small-capacity enterprises. The articles are molded on the vibration platform or with the help of special units. Process operations are carried out sequentially at several work stations.

The aggregate-in-line method of making structures is characterized by splitting the technological process into: individual operations or their groups; performing several different types of operations on universal units; the presence of a free rhythm in the stream; moving the article from the post to the post; molds and articles move from post to post with arbitrary interval depending on duration of operation at given workplace, which can range from several minutes (for example, lubrication of molds) to several hours (hardening post of molded articles).

The aggregate-flow method is also characterized in that the molds and articles are not stopped at all posts of the flow line, but only at those that are necessary for this case. The aggregate-flow method of organization of production is characterised by the possibility of fixation behind one production line of products different not only in size, but also in design. This capability is created by the availability of universal equipment on the production line. Interoperative transfer of products on such lines is carried out by lifting and transportation vehicles. For accelerated hardening of concrete in an aggregate flow method, periodic or continuous chambers are usually used. The small volume of each chamber section allows a minimum of time for loading and unloading the articles, and a large number of such sections create conditions for continuous feeding of the molded article into the hardening chamber .

In an aggregate flow method of production, articles are molded on a vibration platform or on specially equipped units consisting of a molding machine, a concrete laying machine and a machine for laying a mold on a molding station. According to this method, molds with articles moving along the flow can stop not at all work stations, but only at those that are necessary for the manufacture of products of this type.

The absence of a forced rhythm of shape movement allows you to perform several operations at one post. Cement, aggregates through conveyors get into consumable hoppers from where they come into batchers (6). Dosing is determined by the process plan. A certain amount of each component enters the mixer. Then the mixture enters the concrete dispenser, from where it is laid in the mold installed on the vibration platform. After molding, the articles are sent to the steaming chamber.

1.3 Compaction of concrete mixture at aggregate flow flow diagram of production on vibration platform.

Vibration sites are distinguished by a wide variety of types and designs of vibrators - electromechanical, electromagnetic, pneumatic; the nature of the oscillations - harmonic, shock, combined; shape of oscillations and their direction - circular, vertical, horizontal; structural schemes of the table - with a continuous upper frame forming a table with one or two vibration shafts, and assembled from separate vibration units, generally forming a common vibration plane, on which a mold with a concrete mixture is located. Pneumatic devices, electromagnets or mechanical clamps are provided for strength of the mold attachment to the platform table.

The vibration platform is most often a flat table resting through spring supports or special shock absorbers on fixed supports or a frame (bed) of the vibration platform. Springs are designed to extinguish table oscillations and thereby prevent their effect on supports, otherwise their destruction will occur. Vibrator with eccentrics arranged on it is rigidly attached to table in lower part. When the shaft rotates from the electric motor, the eccentrics excite forced vibrations of the vibration platform table, which are then transmitted to the shape with the concrete mixture, as a result, its compaction occurs. The power of the vibration platform is estimated by its lifting capacity (weight of the product together with the mold).

Prefabricated reinforced concrete plants are equipped with unified platforms with a lifting capacity of 224 tons with a frequency of 3000 kol/min and an oscillation amplitude of 0.30.6 mm. These vibratory sites compress rigid concrete mixtures well with a water flow rate of 130-150 l/m1. The use of rigid concrete mixtures reduces cement consumption, accelerates concrete hardening, and improves the quality of finished products. Structures up to 15 m long and up to 3.6 m wide are formed on vibration platforms.

For better compaction of rigid concrete mixtures on vibration platforms, especially when using light porous aggregates, the gravity of which contributes to the compaction of concrete during vibration is small, various surges are used: static, vibration, pneumatic, vibration pneumatic. The best are pneumatic and vibration pneumatic loads, which, increasing the vibration efficiency, do not significantly increase the load on the vibration platform and do not reduce its useful carrying capacity. The amount of load is assigned depending on the properties of the concrete mixture and is 2-5 kPa.

When forming the article, the mold is filled with concrete mixture from the concrete laying bin gradually as it is compacted during vibration. The optimal duration of vibration is determined experimentally and is 1.5-5 minutes.

When forming articles in fixed molds, surface and depth vibrators, as well as hinged vibrators, which are attached to the mold, are used to compress the concrete mixture. The mobility of the concrete mixture is chosen depending on the structure of the shape and the nature of the reinforcement of the product. When making parts in horizontal shapes, rigid and slow concrete mixtures are used. When forming articles in vertical shapes, for example, in the manufacture of wall panels and partitions in an upright position, concrete mixtures with a mobility of 8-10 cm are used, since a slow-moving mixture is difficult to well fill a deep and narrow shape .

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