working principle of spring hammer
Spring hammer is generally used for small forgings. It can light type power hammer. A typical design of a spring hammer. It has a heavy solid frame with a vertical projection on the top. What is the working principle of spring hammer This projection serves as the housing of the bearing, in which the laminated spring oscillates. This spring consists of a connecting rod at the rear end and a vertical head at the other front end, which supports the weight and moves vertically up and down between fixed guides provided for the purpose. At its lower end the connecting rod can connected to an eccentric sheave, which is further connected to the crank wheel.
The jack operates the hammer by pressing down on the treadle, causing the sheave to rotate through the crank wheel, causing the laminated spring to oscillate in the bearing. What is the working principle of spring hammer This oscillation of the spring is responsible for the up and down movement of the nozzle and thus, provides the necessary shocks in forging work. This mechanical type of hammer canequipped with a hand lever which adjusts the stroke of the connecting rod and thus the intensity of the blows. The eccentric type of spring hammer is one in which a rotating eccentric disk can used to create vibrations in the spring.
Spring hammer Testing
A foot ring can operate it called a treadle at the bottom and connected to the shaft at the top by a vertical bar with a clutch at the end. At the top of the hammer is a shaft with a pulley and a solid disk at the end. The pulley can driven via a belt from a line shaft or electric motor. A solid disk at the end of the shaft holds a crank which can eccentrically connected, with a laminated spring at the lower end.
The lifting nib hung from a reciprocating joint connecting the two ends of the laminated spring. When the foot can pressed on the tread the clutch engages with the shaft and the disc carrying the crank starts to rotate, resulting in the oscillating of the engine’s replacement joint. This enables the nozzle to move up and down in the vertical direction. The speed of the feet is completely dependent on the speed of the driving pulley Spring hammers are available in various capacities ranging from 30 to 250 kg. Those with a maximum weight of 50 to 100 kg and a speed of 300 strokes per minute can commonly used in forging shops. A common drawback of these hammers is that their springs often break due to strong vibrations during forging in the forging shop.
Drop the hammer
The Drop hammers can hydraulically operated and widely used to shape parts by dropping a hot bar or billet into a die cavity. Drop forging lifts a heavy weight and allows it to fall under gravity into a closed die, where the forged component can allowed to shrink. As shown in Figure 17, the die attaches its shape to the hot workpiece. Drop hammers can commonly used for forming copper alloys and steel.
It can light hammer powered by an electric motor and struck repeatedly when operated by a foot-operated treadle. This type of hammer can now obsolete and best suited for smaller forgings. Although various designs of this hammer are in use, a typical spring hammer can shown below.
Construction of spring hammer
This layout, an electric motor rotates a pair of pulleys, one slack and the opposite fast.
A slack pulley rotates passively on its shaft.
flywheel can connected to its shaft by using a key so that once the flywheel rotates, it also rotates the shaft.
The shaft itself includes an eccentric sheave, so that once the electrical motor rotates the pulley rapidly, the eccentric sheave additionally rotates with it, offering vertical reciprocating motion to the connecting rod.
top quit of the connecting rod can connected to one give up of the laminated bearing spring.
the opposite stop of this spring can attached to a ram which slides up and down alongside a vertical manual provided in the system frame on the the front of the machine.
A tip (a die if required) can positioned in this ram. Below the ram and plate is a vertical anvil on a base.
The function of spring hammer
The electric motor can usually attached to a slack pulley, but when the hammerer presses the treadle with his foot, the motor can attached to a fast pulley. As the connecting rod goes up, the front end of the spring goes down, and the hook can rotated in the center of the spring. As the connecting rod moves downward, the ram moves upward. Thus the rotation of the motor causes up and down movement of the ram and tube.
Structural Modeling Impact testing
The simulation of impact effects that may encountered by equipment and its components during transport or operation in order to obtain the ability of electrical products to withstand external impact damage. When the spring hammer works, its internal spring generates impact force and releases the impact body. After the impact body inside the spring hammer can released, the surface of the product can impacted. Impact energy determines whether the surface of the product will damaged or not. According to the JJF 1475-2014 Calibration Specification for Spring Hammer, the spring hammer is a measuring instrument and its impact force must can accurately measured. Whether or not the impact force generated by the spring hammer is accurate directly affects the accuracy of the impact test.
Calibration items and methods are specified in JJF1475-2014, including allowable error of signal error, instantaneous load force and impact energy. The instantaneous load force directly affects the impact force. The structure of the spring hammer calibration device is specified in JJF1475-2014. Similarly, this equipment standard can also recommended in IEC60068-2-75 and GB/T 2423.55 standard. According to these standards, the spring hammer can installed on the fixed support, and the calibration work can accomplished by the impact end
The calibration process can accomplished by striking the end of the pendulum rod with a spring hammer.
- When the spring hammer strikes the impact end of the pendulum rod,
- The elastic energy energy of its internal spring can converted into kinetic energy of the hammer. After the spring hits the end of the hammer,
- The impact pendulum rod rotates through a certain angle and the force value can obtained on the readout dial. Its essence is to convert kinetic energy into potential
- Energy without the effect of friction, i.e. E m v m gh = = 1 2 a b 1 2 ( ) In equation (1), ma is the mass of the impacting body in the spring.
- For the hammer, v is the mass of the striking body. velocity, mb is the equivalent
- Mass of the impacting pendulum rod, and h is the equivalent rotational
- Height of the pendulum rod. the main component of the complete
- Calibration tool is the impact result. The total length of the impact end is l, the diameter of the circular
- Hole in the joint is d, the thickness of the impact end is h,
- The top width a, the bottom width b, and the length of the front end of the impact end isc. The initial structural parameters
A spring hammer is a measuring
- Instrument used to test the impact resistance of electrical and electronic components. It mainly tests the mechanical strength of the shell, operating rod,
- Handle, knob, indicator lamp, etc. of electrical products to ensure
- That the products can not damaged by accident or abnormal operation [1, 2]. The working process is that the impact body inside the spring hammer hits the surface of the product. Combined with the surface condition, the strength level of the product can checked, and its safety can ultimately assessed.
- Therefore, the accurate calibration of the spring hammer directly affects the verification of the safety level of electronic equipment products. What is the working principle of spring hammer The calibration parameters of spring hammer are specified in JJF 1475-2014 calibration specification for spring hammer . Calibration of spring hammer can done with spring hammer calibration tool. JJF 1475-2014 can mainly designed with IEC 60068-2-63, IEC60068-2-75, GB/T 2423.44, GB/T 2423.55. These standards also prescribe the principles and construction of the spring hammer calibrating device,
- Particularly the specific structure of the pendulum rod and the end of impact. In practical work, the result of impact carries the workload.
If its structural design Can irrational, the stiffness and structural strength will seriously affected, causing the calibration value to deviate. In recent years,
the response surface method has been one of the hot research issues in the field of structural optimization. What is the working principle of spring hammer Compared to the traditional optimization method, its biggest advantage is that the computed data is relatively small and the computation time is short.
Li J et al used the response surface method to improve the quality of sheet metal forming while optimizing the structural and process parameters of the sheet metal. Zhang Leit al used the response surface method to obtain the optimal design parameters of flexible wheel. Wu Zhaoyun et al  used response surface models to optimize the design of RGV grippers for grain handling.
Reduces mass and improves grip performance. Duan Chenghong et al improved the pipeline design based on the response surface method, which improved the safety. Read more