How is the lap value generally calculated?

The process waste left between the punching parts and between the punching parts and the side of the strip during nesting is called lapping. The function of lap is to compensate for positioning errors and shearing errors to ensure that qualified parts are punched out; the second is to increase the stiffness of strips, facilitate the feeding of strips, and improve labor productivity; At the same time, the lap can also avoid the burr on the edge of the strip during punching, and the gap between the molds can be improved, so as to improve the life of the mold. The lap value has a great impact on the hedging process and the quality of the punching part, so it is necessary to reasonably determine the lap value.

The lap edge is too large, and the material utilization rate is low; If the lap is too small, the strength and stiffness of the lap are not enough, and it is easy to warp or be broken during punching, which will not only increase the burr of the punching part, but sometimes even pull into the die gap unilaterally, resulting in uneven punching force and damage to the die edge. According to the statistics of production, the life of the mold when the normal lap edge is more than 50 times higher than that of the non-lap punching. 1 Factors influencing the lap value (1) Mechanical properties of the material The lap value of hard materials can be smaller; Soft materials and brittle materials have a larger edge value.

2) Material thickness The thicker the material, the greater the lap value. (3) The shape and size of the punching part The more complex the shape of the part, the smaller the fillet radius, and the larger the lap value. (4) Feeding and blocking method: Manual feeding, the lap value of the side pressure device can be smaller; The spacing with the side edge is smaller than the spacing with the retaining pin.

5) Discharge method: The lap of elastic discharge is smaller than that of rigid discharge. 2 Determination of the lap value The lap value is determined empirically. The table is one of the empirical tables of the minimum lap value for reference in design.

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Generally, it is to check the table but it is more troublesome, and the requirements are not too accurate, you can take the lap edge value as 1 times of the plate thickness, which is determined according to the design experience.

The lap value is generally 1 times the thickness of the plate. This is determined based on design experience. It's a hassle to look up the table.

These data can be obtained through the check-and-see-see table, which is found in every textbook. The value of the positioning rod and spring pressure can be accurately calculated by calculating the discharge force.

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1. The subgrade deflection value is calculated according to the relevant formula, the subgrade deflection value is generally about 290 (1 100mm), generally not greater than 290, and the calculation formula is lr=720N *ac*as.

2, deflection value is the load on the subgrade pavement before and after, the size of the subgrade pavement deformation, with 1 100 mm as the unit of calculation. Calculate the deflection value is that in a certain road section, according to the spacing of 20 meters, the vehicle that is loaded with a certain axle (generally with the rear axle 6 tons or 10 tons vehicle) acts on the roadbed pavement, the weighted average value of the residual deformation that is generated.

3, calculating the deflection value has a direct relationship with the design strength of the roadbed pavement, and the smaller the calculating the deflection value, the higher the strength. Before the highway reconstruction, the deflection measurement of the original highway can understand the road conditions of the original highway and serve as a guiding material for the design; Highway construction or after completion, deflection measurement can check whether the construction of subgrade pavement meets the design strength requirement.

4. The design deflection value is the deflection value controlled by the pavement design. It is the unfavorable season of the first year after the completion of the pavement, and the maximum rebound deflection value measured by the pavement under the action of standard axle load is theoretically the minimum deflection value in the service life of the pavement. It is one of the indicators of pavement acceptance inspection control.

The formula is ld=600n *ac*as*ab. Code for Design of Highway Asphalt Pavement.

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5. Detection and calculation of deflection value: through the deflection detection of the roadbed, road surface and the original old road, and the representative value obtained by calculating and sorting. Its function is mainly to evaluate the condition of the subgrade pavement and for the purpose of reinforcement design.

Stamping die punching clearance, according to the research and improvement experience of the die, the size accuracy, section verticality requirements of the high requirements of the parts should be selected small clearance value, section verticality and dimensional accuracy requirements of the press parts, should reduce the punching force, improve the life of the stamping die, can use a larger gap value. Its value can be calculated according to the following empirical formula:

Soft materials: material thickness t 1 mm, punching clearance c = (3% 4%) t

t = 1 ~ 3mm， c = (5% ~8%)t

t = 3 ~ 5mm ，c =(8% ~10%)t

Hard material: t 1mm, c = ( 4% 5% ) t

t = 1 ~ 3mm， c = ( 6% ~8% )t

t = 3 ~ 8mm， c = ( 8% ~13%)t

Therefore, the main factors influencing the clearance value are the material properties and the thickness of the material. The harder or thicker the material, the larger the gap value.

Combining the characteristics of single-process mold and progressive die, the manipulator transfer system is used to realize the rapid transmission of products in the mold, which can greatly improve the production efficiency of products, reduce the production cost of products, save material costs, and have stable and reliable quality.

The stamping die gap should be determined according to the thickness of the plate, the model of the material, etc.

Most iron plate materials t= are calculated using %16, which means that the thickness of the plate * %16, which is very versatile.

Soft materials: copper, iron, aluminum, below 0 with a single +4%. 0 or more to use a single +5%t, 0 or more with a single +7%t, hard material: stainless steel, steel with high carbon content below a single +5% 0 or more to a single +6% t, remember to multiply by the material thickness.

The blanking gap is generally measured by paper cutting test punching and thickness gauge, or to see the bright belt and burr bending of the product, the general plug gasket or thickness gauge.

Effect of clearance on the life of the stamping die:

The life of the stamping die is affected by a combination of various factors, and the gap is one of the most important factors affecting the life of the stamping die. In the stamping process, there is friction between the punch and the punched hole, between the die and the blanking part, and the smaller the gap, the greater the compressive stress of the stamping die, and the more serious the friction. Therefore, too small a gap is extremely detrimental to the life of the stamping die.

The larger clearance can reduce the friction between the punch side and the material, and slow down the adverse effects of uneven clearance due to the limitation of manufacturing and assembly accuracy, thereby improving the life of the stamping die.

The stamping unilateral clearance is generally 10% of the thickness of the material, but in practice, it should be appropriately added or subtracted according to the hardness of the material, the gap should be reduced by the relative softness of the material, and the gap should be appropriately increased by the hardness of the material.

Check the table, mold clearance, and nesting edge value.

Blanking punching die clearance table, or less than 6mm according to the bilateral gap of 10% (10% of the material thickness), 6mm to 10mm to take 12%, the forming gap is the gap of the material thickness, after the shape out, this gap will come out by itself.

The dividend to the divisor ratio (quotient).

The divisor is the standard value of comparison, and the quotient is the ratio of the dividend to the quotient.

2 5 means that 2 is a multiple of 5.

10 5 2 200 100, meaning that 10 is twice as large as 5 and twice as large as 5.

Divide the following number by the first number, and the ratio of 148077:479107:189817 is approximately equal to 1::

Depending on the number of decimal places required, you can round it up yourself.

Think of 148077 as 1,479107 and 189817 remove 14807 to get 1,28.

PE is the capacity of the equipment, which is generally obtained by adding the nameplate capacity of all the equipment KS is the demand coefficient, which is the ratio of the active power (i.e., PJS computing load) required by the electrical equipment at the maximum load to the PE of the equipment capacity.

PJS is the calculation load, which refers to the PJS=PE x KS calculated by statistical calculation of the load

IJS is the calculated current, IJS=PJS (, here UE refers to the rated voltage, UE=380V (three-phase electricity)

COS is the power factor value, generally this value can be obtained according to the load nature, check the table, and also refer to the equipment nameplate.

OSPF is measured as cost, which is calculated based on the bandwidth of the link. Basically, it's inversely proportional to the link bandwidth. In other words, the larger the bandwidth, the smaller the overhead value, and the better the link. It is calculated as follows:

Interface overhead = reference bandwidth logical bandwidth (logical bandwidth is usually configured the same as the physical interface bandwidth).

OSPF calculates the cost of each segment of the link separately, and then calculates the network cost of reaching any destination address from the current node, that is, the multi-segment link accumulation. The path with the least overhead to the destination network is selected as the best path.

If the actual bandwidth value is 10Mbit/s, then the cost=100 10=10 of the interface, and if the actual bandwidth of the interface is 100Mbps, then the interface overhead is cost=100 100=1. However, the current network has entered the 1000M era, and the cost of 100M and 1000M bandwidth in OSPF is the same. Therefore, if the interface bandwidth value is high in practical application, the reference bandwidth value of the port should be reconfigured.