Development and innovation of modern forging hammer technology
Overview By discussing the different principles and structural forms of forging hammer developed by modern electro-hydraulic hammer technology, the innovation of electro-hydraulic hammer technology is embodied, and the development direction of electro-hydraulic hammer technology in the future is demonstrated. The traditional steam-air dual-purpose forging hammer is the leading product in the forging industry in the middle and early stages of the last century. With the rapid development of modern hydraulic technology and electronic control technology, electro-hydraulic hammers have gradually developed, especially in the 1980s. Among them, the liquid-gas electro-hydraulic hammer has been continuously innovated and the technology has become increasingly mature. This technology is suitable for both free forging and die forging. Therefore, this technology has been promoted very quickly and has been recognized by the majority of users. At present, more than 95% of the electro-hydraulic hammers produced in China are liquid-liquid electro-hydraulic hammers. According to the level of maturity of the technology, the electro-hydraulic hammers with different structural principles are arranged in order: 1) liquid-gas electro-hydraulic hammer; 1. Liquid-gas electro-hydraulic hammer 1, the principle The basic principle of liquid-gas electro-hydraulic hammer is: the upper chamber of the working cylinder is closed high-pressure nitrogen, the lower chamber is hydraulic oil, and the middle is separated by the hammer piston. The system controls the lower chamber separately, the lower chamber enters the oil, and the hammer head lifts. The high-pressure nitrogen gas is compressed, the energy is stored, the lower chamber is drained, and the high-pressure nitrogen gas drives the piston to strike the hammer head, referred to as "pneumatic drive, hydraulic energy storage". Electro-hydraulic power head, its main body is a tank, as a fuel tank for short-term oil storage during operation (when not working, the oil in the oil tank enters the oil tank of the hydraulic station placed on the ground through the oil return pipe), and there are eight bolts passing through. The cushion pad and the pre-pressure spring are fixed at the position of the original cylinder. The oil tank is also called a cylinder beam, and a master cylinder is arranged in the middle thereof. The top of the master cylinder is provided with a buffer cylinder, and a buffer piston is arranged therein. The upper part of the piston is filled with nitrogen gas with a certain pressure. The pressure is the same as the pressure at the top of the accumulator. There are two holes in the lower part of the master cylinder which are respectively connected with the quick drain valve and the safety valve. The hydraulic station comes through the pipeline and enters the main control valve and accumulator installed on the upper right side of the tank. The oil chamber in the lower part of the accumulator is directly connected with the main control valve, and the upper part is connected to the gas cylinder group through the pipeline. The main cylinder is provided with a hammer piston, which separates the lower oil from the upper nitrogen, and the upper part of the piston is filled with a certain pressure of nitrogen and communicates with the auxiliary gas tank. The lower part of the hammer rod and the hammer head are rigidly connected, and the wedge iron is pressed tightly, and the operation part is basically unchanged. The hydraulic system adopts the combined transmission constant pressure liquid source composed of pump-accumulator-unloading valve, which not only ensures the stability and reliability of the system but also greatly reduces the installed capacity. The basic actions of the electro-hydraulic hammer are lifting hammer and striking. When lifting the hammer, it is only necessary to operate the main valve so that the high-pressure oil in the accumulator of the oil pump can communicate with the lower chamber of the piston of the master cylinder. The hammer piston quickly completes the return stroke of the hammer head under the action of high pressure oil. When striking, the main valve is operated to make the lower chamber of the piston communicate with the fuel tank, the quick release valve is opened, the oil in the lower part of the piston flows back to the hydraulic tank through the large aperture passage, and the upper part of the piston is under the action of the gas pressure and the weight of the hammer system to make the hammer Accelerate the downward movement until a blow is formed. The acquisition of the energy can be realized by the handle to control the stroke, and the manipulation part can complete various actions such as lifting the hammer, striking, returning, slow rising, slow descending, emergency stopping, and hammer. 2, structure and composition (1). The fuselage part includes: left and right fuselage, left and right rails, base (free forging), etc.; 3. Technological innovation Anyang Forging Machinery Industry Co., Ltd., in the process of promoting the industrialization of electro-hydraulic hammer, relies on its own technical strength, closely links with user processes and requirements, and has the courage to tackle problems and solve a series of technical problems. A number of innovative designs have been made on the electro-hydraulic hammer to create an electro-hydraulic hammer product with “an forging characteristicsâ€, which is described as follows: The comb-shaped guide rails of domestic steam-air forging hammers have the disadvantages of short arm, over-position and no temperature compensation. In order not to cause the hammer head to be stuck due to the temperature rise and expansion to reduce the gap of the guide rail, it is only necessary to increase the cold gap of the guide rail. When hitting, the hammer rod is subject to additional bending moment and is easy to break. When used for multi-cavity forging, the guide rail wears seriously. In order to overcome this weakness, we have made an innovative design for the electro-hydraulic hammer mainframe, using an "X"-shaped rail structure. Since the X-shaped guide rail has a long force arm, the thermal expansion direction of the hammer head is substantially the same as the direction of the guide rail surface, and the thermal expansion has little effect on the guide rail clearance, and the guide rail clearance can be adjusted very small (about 0.2 mm), thus making the forging process The biasing force in the whole is borne by the hammer guide rail, which greatly improves the life of the hammer. (2). Extend the sealing life and avoid oil and gas exchange: a. The upper chamber of the liquid-gas hammer cylinder is high-pressure nitrogen, and the lower chamber is high-pressure oil, so the early electro-hydraulic hammer is easy to occur. (3). Solve the problem of hammer breakage during abnormal life: a. Improve the connection method of the hammer rod and the hammer head. According to the tribological principle, the 3 sets (pressing parts, taper sleeves and hammer rods) are designed to be tightened, so that the hammer rod is changed from the original "double cone structure" to "single The conical structure greatly avoids the generation of stress concentration, thereby achieving the advantages of reliable coupling and easy disassembly. The life of the hammer is doubled. (4). Solving the problem of valve flexibility; The poor flexibility of the early electro-hydraulic hammer operation and the slow down action have always been a problem for users. In the past, "free forging electro-hydraulic hammer is not free". In response to this problem, we have taken the following measures: a. Improve the design of the secondary valve and increase the area of ​​the orifice to increase the flow rate and flow rate during the slow drop. (5). The theory of the rough hammer is used for the transformation of the power head; The theory of electro-hydraulic hammer flexible thin hammer is very famous. It was invented by Lasco Company of Germany. The theory of flexible liquid hammer of electro-hydraulic hammer completely changed the "rail-hammer-hammer" system of the original steam-empty hammer. The rigid condition makes the biasing force in the forging process mostly carried by the hammer guide rail. For the free forging hammer, due to the characteristics of the forging process, the biasing force is not large, and the flexible thin hammer rod plays just right. Its unique superiority. However, for the multi-cavity forging die forging hammer to implement the "head change" transformation, the "flexible thin hammer rod theory" is obviously not applicable. Due to the large biasing force of the multi-cavity forging, coupled with the serious cold-shock phenomenon during the final forging, the early damage of the guide rail is serious, and even the phenomenon of "card hammer" occurs. Therefore, when we carry out the “replacement†transformation, the “rigid rough hammer theory†of the steam-air forging hammer is still used for the die forging hammer with multi-cavity forging and large eccentric force, and satisfactory results are obtained. (6). Innovative design with internal structure of cylinder beam; The early electro-hydraulic hammer power head was connected from the main operating valve to the secondary valve seat by a seamless tube welded at both ends. The pipe is subjected to alternating load during the working process, and the pipe is loaded when the hammer is returned. When the hammer strikes, the pipe is unloaded and recirculated. Therefore, the hammer is broken and the weld is cracked for the hammer with poor working conditions. phenomenon. Since this tube is inside the cabinet of the cylinder beam, once it fails, it is difficult to repair, even if it is difficult to guarantee the quality, it becomes a big hidden danger and also a major factor affecting the life of the power head. In order to solve this problem, we moved the secondary valve seat directly under the main valve, removed the welded pipe, and the cylinder body was made of high-quality steel castings, which realized the unpiped connection inside the cylinder beam and improved. Reliability of key parts of electro-hydraulic hammers. (7). Developed and designed large-diameter valves and secondary valves; With the development and design of large-tonnage electro-hydraulic hammer, the annular area of ​​the lower cylinder of the master cylinder is getting larger and larger, and there must be a quick-release valve and a main valve with matching diameters to ensure the striking energy and strike frequency of the large tonnage hammer. Based on the original 50-type valve, we developed and designed the 70-type main valve and the secondary valve, and then developed the 80-type main valve and the secondary valve. We use 50-type valve for 1 ton, 2 ton free forging and die forging electro-hydraulic hammer, 70 type valve for 3 ton free forging and 3 ton, 5 ton forging electro-hydraulic hammer, and 5 ton free forging electro-hydraulic hammer Type 80 valve is used. (8). The new anti-collision device makes the protection more safe and reliable; The hammer head movement characteristics of the free forging hammer are fast hitting and quick lifting, the hammer head hitting top rate is high, and the cushioning characteristics of the buffer cylinder are required to be high. (9). Solve system heating problems The heating problem of the electro-hydraulic hammer system is also a big technical problem, which seriously affects the sealing performance and working performance of the system. For this, we have taken the following measures to effectively control the heating problem of the system. First, minimize the system liquid resistance, reasonably select the tubing diameter, and control the flow rate within a reasonable range. Second, improve the wear resistance of the main valve and the secondary valve, reduce the internal unloading, and thirdly, adopt a high heat dissipation coefficient. Plate heat exchangers and larger flow cooling pumps increase the cooling rate and the number of oil cycles. (10). Solve the problem of oil passage vibration; The oil circuit vibration problem of the electro-hydraulic hammer is also a great hazard to the reliable operation of the system. For this reason, we have adopted a method of blocking the vibration source and buffering the vibration wave, and achieved good results. First, all the pipes connected to the main engine and the high-pressure pipes connected to the hydraulic station are elastically connected; the second is to increase the buffer accumulator on the high-pressure pipe; the third is to use the earthquake-resistant pressure gauge for the pressure gauge, and four tension springs for the table seat. Suspended, the connecting tube is connected by a micro hose. Second, full hydraulic electro-hydraulic hammer The full hydraulic electro-hydraulic hammer is hydraulic oil used in the working medium of the upper and lower chambers of the working cylinder. The lower chamber of the working cylinder is always connected to the accumulator, and the hydraulic control system is separately controlled to the upper chamber. When lifting the hammer, it is possible to control the striking valve to open the upper chamber to the fuel tank. When striking, the control striking valve connects the upper chamber to the lower chamber. At this time, the oil pressure in the upper and lower chambers is equal but the working area is different, so that a differential striking can be achieved. It can be seen from the principle that in the process of striking, the upper and lower chambers must enter and exit the oil at the same time, and the two chambers flow, so the oil speed is greatly limited, otherwise the efficiency will be very low, and the best solution is to reduce the flow rate. Once the speed is reduced, to maintain the constant energy (E = 1/2mv2), the quality of the hammer must be increased. To maintain a high frequency of blows, the trip must be reduced. Simply speaking, it is “large hammer head, short strokeâ€, so the full hydraulic hammer is only suitable for the die forging hammer, especially suitable for the program-controlled die forging hammer, and is not suitable for free forging with strong manual operation flexibility. This theory, we can be verified from the international trend of forging hammer development. Third, program-controlled full hydraulic die forging hammer 1, the principle: The basic principle of the program-controlled full hydraulic die forging hammer is: the oil pump-accumulator is used for transmission, the lower chamber of the cylinder is usually pressed, and the hydraulic system controls the upper chamber with a single cavity. The upper chamber inlet valve (also called the striking valve) is opened, and a total of three parts of high pressure oil from the oil pump, the accumulator and the lower chamber led by the differential circuit enters the upper chamber, thereby realizing the acceleration downward stroke and the striking stroke of the hammer head. Once the upper chamber is relieved, the hammer immediately returns quickly, and the striking energy is achieved by controlling the length of the closing time of the striking valve. 2, the basic structure (1). The fuselage adopts a "U" shaped fuselage in which the column and the anvil are integrated. Although this structural form brings certain difficulties to casting, lifting and machining, it has the following advantages: a. Increases the longitudinal, lateral and tipping stiffness of the column, ensuring the precise guiding of the hammer and facilitating the improvement of raw materials. The utilization rate of the bU-shaped fuselage makes the two columns also become part of the weight of the anvil, which is beneficial to the reduction of the weight of the whole machine and the improvement of the striking efficiency; the impact noise generated by the cU-shaped solid casting body is significantly smaller than that of the box shape and the arched column. The fuselage. (2). Guide rail: The comb-shaped guide rail of domestic steam-air forging hammer has short force arm and no disadvantage of temperature compensation. In order not to cause the hammer head to be stuck due to the temperature increase and expansion, the gap of the guide rail is reduced, so that the cold gap of the guide rail is increased, which is the reason why it is difficult to perform precision die forging on the steam-air forging hammer. The 50KJ program-controlled full hydraulic hammer developed by our company adopts the "X"-shaped guide rail structure. Since the hammerhead expands radially when heated, and the guide faces are arranged diagonally, the guide gap is not reduced due to thermal expansion of the hammerhead. Our company's program-controlled hammer increases the width of the guide plate, and the X-shaped guide rail has a longer force arm, which will obviously reduce the specific pressure acting on the guide surface when the bias is applied, which is beneficial to prolong the service life of the guide plate. (3). Hydraulic system a. The hydraulic system adopts the oil pump-accumulator combination transmission, and the lower chamber of the main cylinder is always in communication with the accumulator, which is normal pressure. The hydraulic system only controls the upper chamber. It controls the closing time of the striking valve to achieve the striking energy. The striking valve is a three-stage control valve. The pilot valve is a two-position three-way reversing valve. The system demands its quality. Very high, both high frequency and high repeatability requirements, so we use imported original parts; b. The striking valve adopts a cone valve structure, which has the advantage of no wear compared with the conventional sliding valve, and the sealing reliability is greatly improved; c. The fuel tank adopts a top-mounted structure, and the internal oil circuit is closed on the main valve block. This structure makes the hydraulic system integrated. Compared with the fuel tank adopting the side-mounted structure, the length of the pipeline system is greatly shortened, and the energy loss is reduced by more than one time. In addition, through integration, the oil circuit connection realizes a tubeless connection and increases the reliability of the connection; d. In the hydraulic system, a safety valve is arranged between the accumulator and the lower chamber. Once the hammer is broken from the middle, the lower chamber oil and the accumulator are cut off immediately, thereby improving the safety of use. (4). The damping system adopts the German (Qingdao) separation and solid technology to isolate the vibration generated by the forging hammer during the impact process. (5). The program control system controls the striking energy and the number of strikes according to the forging requirements program. Our program-controlled full hydraulic hammer adopts OMRON medium-sized C200HS programmable controller and is equipped with digital input and output modules to set the blow on the control panel. energy. Four analog inputs are used in the protection system. The motor adopts the embedded temperature sensor method to collect temperature data for PLC analysis. The oil temperature uses the plug-in sensor to collect the oil temperature change for the whole process PID (cycle control) adjustment. 3, performance characteristics (1). It can achieve precise control of the striking energy. By precisely controlling the closing time of the striking valve, the programmable hammer not only ensures the energy required for the forging, but also does not generate additional impact kinetic energy, so the life of some key components such as the hammer, the hammer and the upper and lower molds is greatly improved. (2). The return speed is very fast. Since the lower chamber of the main cylinder always passes the accumulator, once the upper chamber is relieved, the hammer can be lifted quickly, so the contact time of the mold is short. This performance combined with the precise control of energy can increase the service life of the forging die by more than one time. (3). High precision for forging: Since the guide rail adopts an "X"-shaped structure, the gap of the guide rail can be adjusted very small, and the forged piece produced is highly accurate. (4). High material utilization rate Since the energy can be controlled, the precision of the blank is very high, the forgings of the forged parts are relatively uniform, and because the forging precision is high, the upper and lower molds do not have a wrong mold phenomenon, so the material utilization rate is high, which lays a foundation for less cutting. (5). Low noise Since the product is a combat energy programmable device, a program is programmed to make the forged piece, but not much energy is left, so the noise is small. The operator of the traditional forging hammer relies on the sound of the mold to judge whether the forging is made, sometimes the judgment is not allowed, and it is accustomed to play a few more times, which is actually redundant. (6). No collision phenomenon By accurately calculating and designing the size of the orifice and the orifice in the hydraulic system, the hammer head is cushioned to the top, which is smooth and has no roofing phenomenon. (7). Low vibration Because the product can be controlled by the impact energy, no excess energy is generated, and the filter body is equipped with German brand technology to produce the brand-name vibration isolator, which has no influence on the surrounding machine tools and residential areas. (8). Environmental protection: Because the product has small impact noise, shock absorber and low vibration during the impact process, it is an environmentally friendly product. (9). Forging quality is relatively stable Thanks to the control of the program controller, the forging process of various forgings can be stored in the program and can be transferred up and used as needed. Therefore, the same forging can obtain consistent strike energy and number of strikes, avoiding the diversity of manual operations. Therefore, the quality of forgings is relatively stable. Fourth, manual full hydraulic die forging hammer 1, the principle: The basic principle of manual full hydraulic die forging hammer is: using oil pump-accumulator drive, through a manual slide valve to act as a pilot valve to control four large-diameter cartridge valves to achieve lifting hammer, suspension hammer, slow drop, Strike and other actions. 2. Advantages and disadvantages compared with programmable hammers: advantage: (1). The operating mechanism can be operated manually or pedaled. The energy is realized by the operator controlling the stroke of the hammer, and the operation is relatively flexible. Disadvantages: (1). Energy cannot be precisely controlled, and it is difficult to achieve precision forging; Kaiping Jenor Sanitary Ware Co., Ltd , https://www.sanitaryjenor.com
2) Full hydraulic electro-hydraulic hammer:
3) Programmable full hydraulic die forging hammer,
4) Manual full hydraulic die forging hammer.
(2). The anvil part includes: anvil, anvil pad, lower anvil (free forging) and related parts;
(3). The power head part includes: a cylinder beam, a hammer head, a hammer rod, a cylinder, a buffer cylinder, a connecting plate, an upper anvil (free forging), etc.;
(4). The hydraulic station part includes: fuel tank, motor - oil pump set, electronically controlled unloading valve, valve seat, electronically controlled temperature gauge, heat exchange motor pump set, heat exchanger, oil filter, etc.;
(5). Special valve and safety valve parts include: main control valve, quick discharge valve, safety valve, Hall switch, etc.;
(6). Pipeline and lubrication parts include: pipeline support, oil and gas pipe, lubrication pump, etc.;
(7). Manipulating part: consisting of an operating handle assembly;
(8). Gas cylinder group parts: nitrogen bottle, gas cylinder frame and gas cylinder, high pressure ball valve, etc.;
(9). The electronic control part includes: main motor, cooling motor, electric control box, button station, etc.;
(10). The water cooling part includes: a cooling water tower, a water tank, a water pump, a motor, a water pipe, and a valve (the above user-owned);
(11). The basic part includes: anchor bolt assembly and the like.
(1). Designed the "X" shaped rail structure:
b. Wear-resistant, high-temperature-oriented guide ring and Ky ring with strong compensation capability.
c. According to the difference between the sealing oil and the sealing medium, Ky rings with different Shore hardness are selected.
d. Strengthen the positioning of the power head.
b. The surface of the hammer rod is rolled to improve the surface hardened layer, thereby improving the service life of the hammer rod.
b. Shorten the distance between the main valve and the secondary valve to achieve a "zero distance" connection, thereby shortening the reaction speed of the secondary valve and eliminating the effect of the volume effect.
Through the analysis of the shortcomings of the early electro-hydraulic hammer buffer cylinder structure, we improved the design, and the air chamber of the buffer cylinder and the accumulator were matched to match the pressure, which improved the reliability of the anti-collision roof.
(2). The structure is simple and easy to maintain.
(2). Because the oil pressure is smaller than the programmable hammer, the stroke is longer, the strike frequency is smaller, and the production efficiency is lower.