Reinforcement treatment of compressed springs

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The circular spring, due to its helical geometric shape, is more difficult to strengthen than flat plate springs. Additionally, it is essential to strictly evaluate the strengthening effect of the cross-section of the circular spring to fully understand its resistance to fatigue fracture. The circular springs are individually fed into the shot blasting chamber through a continuous conveyor chain system. Inside the shot blasting chamber, there is a set of parallel roller tracks that continuously roll while the springs are being strengthened, allowing the circular springs to rotate and move forward. This rotating passage allows high-speed shot flow to pass through the various rings of the circular spring, impacting the inner circle's metal surface, which is precisely where the stress is most concentrated. For applications with high production requirements, a strengthening device that can simultaneously spray two circular springs can be selected. The latest research results involve combining multiple nozzles with the original shot blasting equipment to target specific areas of the circular spring (stress concentration areas) with more focused and powerful shot treatment. Plate Spring Strengthening A continuous through-type shot blasting device can be used for individual strengthening treatment of plate springs, exposing the geometric concave surface of the plate springs to high-speed shot flow. A typical model includes a shot head for projecting the top of the plate spring, with a side-mounted shot head that simultaneously sprays the left and right sides of the plate spring. The standard model of this plate spring strengthening equipment has a throughput speed of 10 feet per minute. If higher production speeds are required, the number of shot heads can be increased, and the motor frequency can be adjusted. Under working conditions, plate springs are repeatedly subjected to unidirectional bending stress, so they are sometimes stress-strengthened. During the strengthening process, the situation of "stress strengthening" that the plate spring will experience in future use is simulated, applying a "static stress" in the direction of the load while performing shot blasting strengthening. After strengthening, the applied static stress is released. Experiments have shown that stress strengthening can further extend the service life of plate springs compared to conventional strengthening. Suspension Spring Strengthening Thanks to high-stress lightweight design, the weight of suspension springs has significantly decreased in recent years, with stress levels exceeding 1000 MPa being very common in new model suspension springs. Springs operating under such high stress exceed the limits of the material, so additional strengthening methods (such as shot blasting) must be employed. OEM manufacturers impose very strict testing standards on automotive suspension springs, with the longest test cycle lasting up to 70 days (10 weeks). This is primarily because suspension springs working under high-stress conditions can suffer from corrosion fatigue failure if the surface is subjected to stress corrosion. If the broken end of the spring punctures a tire, it could lead to significant safety and personal injury incidents. Shot blasting is the most effective strengthening method for suspension springs. After appropriate shot blasting, the fatigue life of high-stress springs can be increased by more than five times. Currently, steel wire shot is predominantly used for suspension spring shot blasting, with multiple shot blasting (using different shot diameters) commonly applied. The surface compressive stress intensity and depth are important indicators of shot blasting effectiveness. Good shot blasting surface stress should be at least -600 MPa, reaching -800 MPa at a depth of 50 µm. The surface compressive stress of stress-blasted springs can exceed -800 MPa, reaching -1200 MPa at a depth of 50 µm. Currently, well-known spring manufacturers both domestically and internationally, such as Liao Yang Kexuo, commonly use a continuous through-type anti-rolling frame strengthening device, where workpieces are transported via a hanging conveyor chain. Each part must undergo three shot blasting treatments at three different positions, according to a set time cycle. After strengthening is completed, the shot head stops, the discharge door opens, and the strengthened workpiece is automatically lifted out, allowing a new workpiece to enter and a new cycle to begin. This equipment can achieve a production capacity of 500 pieces per hour.

The circular spring, due to its helical geometric shape, is more difficult to strengthen than flat plate springs. Additionally, it is necessary to strictly evaluate the strengthening effect of the circular spring's cross-section to fully understand its resistance to fatigue fracture.

The circular springs are individually fed into the shot blasting chamber through a continuous conveyor chain system. Inside the shot blasting chamber, there is a set of parallel roller tracks that continuously roll while strengthening, causing the circular springs to rotate and move forward. This rotating passage allows high-speed shot flow to pass through the various rings of the circular spring, impacting the metal surface of the inner ring, which is precisely where the stress is most concentrated.

For applications with high production capacity requirements, a strengthening device that can simultaneously spray two circular springs can be selected. The latest research results are based on the original shot blasting strengthening equipment, combined with multiple nozzles, for targeted and concentrated shot treatment of specific areas of the circular spring (stress concentration areas).
Plate Spring Strengthening
A continuous through-type shot blasting strengthening device can be used to individually strengthen plate springs one by one, exposing the geometric concave surface of the plate spring to high-speed shot flow. A typical model includes a shot head for projecting the top of the plate spring, with a side-mounted shot head that simultaneously sprays the left and right sides of the plate spring.

The throughput speed of this standard plate spring strengthening device is 10 feet per minute. If a higher production speed is required, the number of shot heads can be increased, and the motor frequency can be adjusted. Under working conditions, the plate spring is repeatedly subjected to unidirectional bending stress, so it is sometimes stress-strengthened. During the strengthening process, it simulates the 'stress strengthening' that the plate spring will experience during future use, applying a 'static stress' in the direction of the load while performing shot blasting strengthening. After strengthening, the applied static stress is released. Experiments have shown that stress strengthening can further extend the service life of plate springs compared to conventional strengthening.

Suspension Spring Strengthening
Thanks to high-stress lightweight design, the weight of suspension springs has significantly decreased in recent years, with stress levels >1000Mpa being very common in new model suspension springs. Springs operating under such high stress exceed the limits that materials can withstand, so additional strengthening methods (such as shot blasting) must be employed.

OEMs have very strict testing standards for automotive suspension springs, with the longest test cycle lasting up to 70 days (10 weeks). This is primarily because suspension springs working under high-stress conditions can experience corrosion fatigue failure if the surface is subjected to stress corrosion. If the broken end of the spring punctures a tire, it could lead to significant safety and personal injury incidents.

Shot blasting is the most effective strengthening method for suspension springs. After appropriate shot blasting, the fatigue life of high-stress springs can be increased by more than five times. Currently, most suspension springs use steel wire shot for shot blasting, and multiple shot blasting processes (with different shot particle diameters) are commonly applied. The surface compressive stress intensity and depth are important indicators of shot blasting effectiveness. A good shot blasting surface stress should be at least -600Mpa, reaching -800Mpa at a distance of 50um from the surface. The surface compressive stress of stress-blasted springs can exceed -800Mpa, reaching -1200Mpa at a distance of 50um from the surface.

Currently, well-known spring manufacturers both domestically and internationally, such as Liao Yang Kexuo, commonly use a continuous through-type anti-rolling frame strengthening device, where workpieces are transported via a hanging conveyor chain. Each part must undergo three shot blasting processes at three different positions, according to a set time for three cycles of shot blasting strengthening treatment. After strengthening is completed, the shot head stops, the discharge door opens, and the strengthened workpiece is automatically lifted out, allowing a new workpiece to enter, starting a new cycle. The capacity of this equipment can reach 500 pieces per hour.

The spring-loaded quick-closing butterfly valve consists of several key components: a valve body, a butterfly disc, a spring mechanism, and an actuator. The valve body houses the butterfly disc, which is mounted on a shaft that allows it to rotate. The spring mechanism is designed to automatically close the valve quickly when the actuator is released or when there is a loss of power. This design ensures rapid sealing of the valve, preventing backflow and maintaining system pressure. The actuator can be manual or automatic, providing flexibility in operation.

The air spring company Actas has begun construction of its production base in Zhejiang.

Warm congratulations on the launch of the revamped website of Taiwan Da Fa Spring Industry Co., Ltd!

2011-07

Dawn Heavy Industries leads the development of domestic spring cone crushers.

The world's first patent for a cone crusher was published in 1878, and it wasn't until 1898 that a product was made. The United States began using cone crushers at the end of the 19th century. The spring cone crusher was designed by the Simmons brothers from Milwaukee, USA, hence it is named the Simmons cone crusher. This machine has a history of about a hundred years; although it has gradually improved and its structure has become more refined, the basic structure has not undergone significant changes. In 1954, China designed and produced the 1200 spring cone crusher based on the Soviet Union's 2100 and 1650 spring cone crushers. In 1958, a large 2200 spring cone crusher was also designed and manufactured. After years of repeated research and practice, the old series of spring cone crushers overcame issues such as insufficient spring pressure, low component strength, and certain structural flaws. Currently, the mass-produced spring cone crushers come in five specifications: 600, 900, 1200, 1750, and 2200, with 14 different cavities. Compared to similar crushers from advanced countries, domestic spring cone crushers still have gaps in quality and performance. To catch up with the world's advanced level, domestic heavy machinery factories have introduced the Simmons and rotary cone crusher technology from the American Nordberg company and collaborated to manufacture this series of cone crushers. The basic parameters specified by the new standards for cone crushers are also comparable to those of the Simmons cone crusher. Therefore, the spring cone crushers produced domestically in the future will essentially be Simmons crushers, and older products will gradually be phased out. The Simmons cone crusher developed and manufactured by Dawn Heavy Industry is based on the introduction and absorption of foreign technology, designed and developed according to customer needs, and based on the principles of laminated crushing and the concept of more crushing and less grinding. It integrates high swing frequency, optimized cavity shape, and reasonable stroke into a modern high-performance spring cone crusher. Practice has proven that the CS series high-efficiency spring cone crusher, with its excellent performance, reliable quality, and high cost-effectiveness, has won the trust of users worldwide and is an ideal substitute for traditional cone crushers. Dawn Heavy Industry leads the development of domestic spring cone crushers with its own brand, technology, and strength.

2011-07

Chinese and foreign spring companies gather in Dongguan to exchange new technologies.

Yesterday, the opening ceremony of the 2011 National Spring Industry New Products, New Technologies, and Technology Information Exchange and Exhibition was held for the first time in Dongguan, where dozens of domestic and foreign spring manufacturing companies gathered to exchange new technologies. The exhibition was jointly organized by the National Spring Standardization Technical Committee, the General Parts Product Quality Supervision and Inspection Center of the Machinery Industry, and other institutions. Well-known spring manufacturing companies and experts from Italy, Japan, and Taiwan participated in the conference. A representative from a spring manufacturing company in Dongguan stated that there are currently dozens of spring manufacturing companies in Dongguan, but the overall technical level is not high. Many companies survive by competing on price, and those that want to grow need to improve their technical capabilities. The exhibition serves as a great platform for technical exchange and learning.

2011-07

Points to note before using a spring scale

1. Observe the measuring range, as shown in Figure 1, the range of the spring scale is 5N. Before use, estimate the size of the force to be measured; the force being measured must not exceed the range of the spring scale, otherwise, it may damage the spring scale. 2. Observe the scale value of the spring scale, which is the value represented between the two smallest graduations. Understanding the size of the scale value is beneficial for accurate reading. As shown in Figure 1, the scale value of the spring scale is 0.2N. 3. Check if the pointer is pointing at the zero graduation line. If it is not, it should be zeroed; otherwise, the measurement results will be inaccurate. As shown in Figure 2(d), when no force is applied, the pointer is below the zero graduation value, and when reading the measurement after use, a portion of the value above the pointer will be included, leading to an overestimated measurement result. 4. Before using the spring scale, gently pull the hook back and forth a few times to check if the spring is in contact with the casing, if there is any friction, or if there are any signs of stiffness.

2011-07

Air suspension: springs installed on the wheels.

Air suspension maintains the same structure as traditional suspension, consisting of two main components: springs and shock absorbers. The difference is that the springs in air suspension are filled with high-pressure air, allowing the stiffness of the springs to vary according to different needs; the damping of the shock absorbers is also adjustable rather than fixed. In other words, the biggest difference between air suspension and traditional suspension is that the characteristics of the suspension are variable, such as height and stiffness, which can be adjusted based on different road conditions. As a result, users have a lot of options when it comes to setting suspension characteristics. Vehicles equipped with air suspension typically offer several modes: automatic, comfort, normal, and sport, allowing users to choose different modes based on road conditions and personal preferences. In automatic mode, the onboard computer adjusts the height of the chassis and the stiffness of the suspension based on vehicle speed and various dynamic parameters. For example, at high speeds, the chassis will automatically lower, and during aggressive driving, the suspension will become stiffer. However, the computer's calculations may not always be accurate, and its response may not be very proactive, which is why there are other modes to choose from. In comfort mode, the chassis is adjusted to the highest position, and the suspension becomes the softest, making it suitable for driving on bumpy roads and greatly improving driving comfort. However, if aggressive driving occurs in this mode, the vehicle will sway significantly, and the limits are relatively low. In normal mode, the height of the chassis and the stiffness of the suspension are at a medium level, suitable for well-paved roads. In sport mode, the chassis is set to the lowest position, and the suspension becomes the hardest, suitable for aggressive driving, although comfort is compromised compared to the previous two modes. From our experience, except for sport mode, the height of the chassis can be manually adjusted in other modes to improve the vehicle's passability, which is very user-friendly. The emergence of air suspension gives a vehicle multiple personalities and greatly enhances its adaptability to different road conditions, making it a beneficial feature for users. Due to the precision of air suspension technology, it is relatively expensive, and maintenance costs are also higher. Air suspension is mostly equipped on luxury models, such as the Mercedes-Benz S-Class, Porsche Cayenne, Audi Q7, etc. However, with the popularization of technology and the reduction of costs, this feature is now trending downwards, with some luxury brand models now available at around 500,000 yuan.

2011-07

How to maintain a spring mattress

As long as used properly, high-quality spring mattresses are generally sturdy and durable, and can last for a long time. However, attention should be paid during use: 1. Avoid excessive deformation of the mattress during transportation. Do not bend or fold the mattress, and do not tie it tightly with ropes. 2. Do not allow excessive localized pressure on the mattress. Avoid standing on the mattress for long periods or letting children jump on it to prevent localized compression that can cause fatigue deformation and affect elasticity. 3. Do not sit on the edge of the mattress for extended periods. 4. Regularly flip the mattress for use; it can be flipped upside down or rotated end to end. Generally, it should be changed every three months in a typical household. 5. In addition to using bed sheets, it is best to cover the mattress with a mattress protector to avoid soiling. Alternatively, choose a mattress with a removable cover for easy cleaning. 6. Remove the plastic packaging when using the mattress to maintain ventilation and avoid moisture. Do not expose the mattress to direct sunlight for too long. 7. For spring mattresses, place a cotton mat or blanket at the contact points with the bed frame to reduce friction and extend its lifespan. 8. A full coconut mattress should be supported by a wooden board or similar, and should not be placed in mid-air.

2011-07

The spring-type quick-closing butterfly valve mainly consists of the butterfly valve, hydraulic-spring drive device, hydraulic station, and electric control box. When opening the valve, the system sends a command (the electric control box is set to remote control), the hydraulic station operates, hydraulic oil enters the bottom of the oil cylinder to push the piston, which drives the butterfly valve to open, while the spring in the spring cylinder is compressed to store energy. In case of an emergency in the working system, the butterfly valve will receive an accident signal and quickly close under the action of the spring, with a closing time of 0.13 to 0.15 seconds, thus protecting the working system and pipeline equipment. Since the working medium of the quick-closing butterfly valve is medium to high-temperature gas, a special structure was adopted in the design of the butterfly valve. (1) Butterfly Plate: The butterfly plate adopts a three-eccentric structure, allowing the sealing surface of the butterfly plate to immediately disengage from the valve body sealing surface at the moment of opening, and only at the moment of closing does the sealing surface of the butterfly plate contact and press against the valve body sealing surface to ensure sealing, completely eliminating wear and scratches between the two sealing surfaces. The conical structure also has a self-centering function, ensuring the butterfly plate is properly aligned. (2) Floating Sealing Ring: The metal-graphite sandwich sealing ring of the butterfly plate adopts a floating sealing form. When temperature changes occur during the installation or use of the butterfly valve, the floating sealing ring can compensate for the slight deformation of the valve body, keeping the sealing of the butterfly valve in optimal condition. (3) Shaft End Temperature Compensation Mechanism: Due to the high operating temperature of the butterfly valve, and considering the thermal expansion effect of the valve shaft, temperature compensation mechanisms are added at both the upper and lower shaft ends to prevent the valve shaft from being pressed against, which would prevent the valve from opening normally. Several groups of support spacers, which function similarly to disc springs, automatically adjust for the dimensional changes of the valve shaft caused by temperature, compensating for adverse factors caused by excess deformation, thus ensuring that the butterfly plate does not deviate, the shaft end does not leak, and the tail end does not get damaged. The normal working state of the quick-closing butterfly valve (powered state) is normally open, and it only requires a quick close when a fault occurs in the system (power-off state). Based on this characteristic, the drive device must have an automatic reset function, meaning that when powered, the drive device opens the butterfly valve, and when power is off, the drive device automatically resets to close the butterfly valve. There are many types of automatic reset drive devices, and considering the high safety performance requirements of the butterfly valve, a structure using a fork drive and spring reset is adopted, which mainly consists of a housing, fork, oil cylinder, piston, piston rod, spring, and spring cylinder. Since the quick-closing time of the butterfly valve is required to be within 0.15 seconds, and considering performance, the pins in the fork are made of alloy steel, and cylindrical roller bearings are assembled at the contact part of the fork, transmitting the piston force of the oil cylinder to the fork in a rolling manner. This reduces friction, increases lifespan, and improves torque transmission efficiency. Due to the use of a spring action mechanism, careful consideration has been given to the safety of the spring, with an independent safety protection screw, allowing for the installation and disassembly of the spring on-site without special tools, ensuring the safety of the operator. This makes the loading and unloading of the spring both safe and convenient.

2011-07

Reinforcement treatment of compressed springs

Xiamen Dafa Spring Industry Co., Ltd

Telephone:0592-7300817 7300818

Fax: 0592-7300819

E-mail:xmtafa@163.com

Address: Xiyang Industrial Zone, Wuxianzhen, Tongan District, Xiamen City

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