Calculation of the area of the exhaust block in die casting,

The area is calculated as length and width = area.

According to the exhaust method, the die-casting mold is divided into: 1. natural exhaust, 2. strengthened exhaust - exhaust block, 3. vacuum die-casting.

The exhaust groove is generally arranged at the rear end of the overflow groove. The total cross-sectional area of the exhaust groove is generally 20% to 50% of the total cross-sectional area of the inner gate. Generally speaking, the exhaust groove depth of zinc alloy is; The depth of the exhaust groove of aluminum alloy and magnesium alloy is in; The depth of the exhaust groove of the copper alloy is in; The width of the exhaust groove varies from 8 to 25mm.

When the die-casting mold is die-casting, the gas in the mold cavity is discharged at high temperature and high speed, followed by the molten metal liquid at a higher temperature, so it is necessary to deliberately add the exhaust corner to avoid direct shooting, and the exhaust terminal can be adjusted to make it against the place that is not easy to hurt people.

Die-casting molds are divided into the following according to the exhaust method:

1. Natural exhaust.

2. Strengthen the exhaust - exhaust block.

3. Vacuum die-casting.

Natural exhaust is the traditional exhaust groove. The exhaust groove is generally arranged at the rear end of the overflow groove. The total cross-sectional area of the exhaust groove is generally 20% to 50% of the total cross-sectional area of the inner gate.

Generally speaking, the exhaust groove depth of zinc alloy is; The depth of the exhaust groove of aluminum alloy and magnesium alloy is in; The depth of the exhaust groove of the copper alloy is in; The width of the exhaust groove varies from 8 to 25 mm, of course, there are exceptions, and it must be adjusted based on experience and mold trial.

1. An exhaust groove is set at the end of the overflow groove (slag collection bag), and the thickness of the exhaust groove is gradually thinned. Because it is simple, this method is more commonly used, but the disadvantage is that once the exhaust groove is blocked, it will affect the exhaust effect.

2. Centralized exhaust block. A centralized exhaust block like a washboard is set up at the place where the casting is rolled for exhaust, and the exhaust block is provided with a cooling channel to cool the molten metal that rushes up. This method is now widely used for more complex molds.

Most mold flow analysis software is used to determine the location and number of exhaust blocks, and it is also used at the same time as the exhaust groove.

3. Forced exhaust. A vacuum pump and exhaust device are used to forcibly remove the air in the cavity before filling. This method has the best effect, but it has high requirements for the sealing performance of the mold and the response requirements for the plugging mechanism of the exhaust port.

Now some mold factories will also use the gas collector block together with vacuuming, and have achieved good results.

Do a mold flow analysis to see the exhaust position.

Open the vent in the right place.

Because the gas in the mold cavity is discharged at high temperature and high speed when the die-casting mold is die-casting, followed by the molten metal liquid at a higher temperature, the exhaust block should be set, and the exhaust terminal can be adjusted.

Injection specific pressure selection basis: general parts: 30-50 (mpa); Load: 50-80 (mpa); Thin-walled pressure-resistant parts: 80-120 (MPa). The area of the gating system is generally calculated according to 30% of the projection area of the casting itself.

To be on the safe side.

Because the gas in the mold cavity is discharged at high temperature and high speed when the die-casting mold is die-casting, followed by the molten metal liquid at a higher temperature, it is necessary to artificially and deliberately add the exhaust corner to avoid direct shooting, and the exhaust terminal can be adjusted to make it against the place that is not easy to hurt people.

The safety factor is smaller, and such a large tonnage is generally taken. Because the larger the material, the greater the inhomogeneity. The greater the specific pressure requirement of the injection. The calculation of the press of about 2000 tons has to be taken.

What is 40 enough? Generally, thin-walled, structural parts 50 60, airtight parts, stressed parts 80 90. If there is a slider, the projection area of the slider should also be calculated, and the slider needs to be multiplied by the tan (angle of the locking block) - generally 10 15°.

It is also said that the safety factor is small, don't mislead people's children. The safety factor is generally.

You have a problem with this stress bringing.

1.If you have a slider, be sure to calculate the projected area of the slider in the direction of the opening and closing mold.

Calculation formula: s cast = s (the projected area of the slider along the direction of movement of the slider) * tana

A: The angle between the projection surface of the slider along the direction of movement of the slider and the opening and closing directions.

Add the s to the projection area.

2.See if the product is eccentric (that is, the gating system, the drainage system, and the casting are not in the center of the formwork), if it is not eccentric, you have no problem with your calculation. But it's generally eccentric.

Eccentricity calculation method.

The gating system, the overflow system, and the casting are divided into small squares, e.g. into regular squares. Take the center of the square block as the calculation point. Calculations are performed using the moment equation.

Examples: (1) Non-eccentric.

The expansion force is 10000kn (1000t), then the force allocated to each big bar is 2500kn (250t), 250*4=1000t, then it is possible to choose a 1000t die-casting machine.

2) Eccentric.

The expansion force is 10000kN (1000t), and it is 350t for bar 1, 150t for bar 2, 250t for bar 3 and 250t for bar 4

Then you should choose a die-casting machine with 350*4=1400t.

To sum up, the die-casting machine does not guarantee the total clamping force, but the clamping force of one of the large bars (the highest).

Important things to say three times, please give points and likes, welcome friends to exchange die-casting products to casting manufacturability analysis, mold design, simulation and on-site process!

Important things to say three times, please give points and likes, welcome friends to exchange die-casting products to casting manufacturability analysis, mold design, simulation and on-site process!

Important things to say three times, please give points and likes, welcome friends to exchange die-casting products to casting manufacturability analysis, mold design, simulation and on-site process!

The entire area from the cake, runner, product, overflow (slag bag), to the exhaust is also called the projection area of the product.

Exhaust slots can be used for exhaust ducts, exhaust ducts, exhaust blocks or vacuum die-casting, and sometimes the flow channels can be modified to change the filling state to make it easier to vent.

The main purpose is to consider problems such as proximity molding defects and porosity problems inside the product!