GB/T 21269-2018Cold chamber die casting machines (English PDF)

3.6 Most Metal Shot Weight

Most metal shot weight refers to the maximum mass of molten metal that can be poured into the pressure chamber at one time.

3.7 Horizontal Cold-chamber Diecasting Machine

Horizontal cold-chamber diecasting machine refers to a cold-chamber diecasting machine with horizontally installed pressure chamber.

3.8 Vertical Cold-chamber Diecasting Machine

Vertical cold-chamber diecasting machine refers to a cold-chamber diecasting machine with vertically installed pressure chamber.

3.9 Diameter of Pressure Chamber

Diameter of pressure chamber refers to the inner diameter of pressure chamber.

3.10 Once Dry Cycle Time

Once dry cycle time refers to the time required for each dry cycle of the die casting machine in the operating sequence.

NOTE 1.for the horizontal cold-chamber diecasting machine, once dry cycle time refers to. in the automatic state, the sum of the action times of mold clamping, injection, mold opening, injection return, ejection and ejection return.

NOTE 2.for the vertical cold-chamber diecasting machine, once dry cycle time refers to.

the sum of the action times of mold clamping, injection, injection return, returning charge, returning charge return, mold opening, ejection and ejection return.

3.11 Shot Position

Shot position refers to the position of the pressure chamber on the fixed mold mounting plate, which is generally determined by the number and distance of the pressure chamber located at the center of symmetry of the tie bars of the die casting machine and the position adjustable downward from the center.

3.12 Diameter of Pressure Chamber Flange (for horizontal cold chamber

die casting machine)

Diameter of pressure chamber flange refers to the diameter of the flange of the pressure chamber protruding from the fixed mold mounting plate when the pressure chamber is installed on the fixed mold mounting plate.

3.13 Height of Pressure Chamber Flange (for horizontal cold chamber die

casting machine)

Height of pressure chamber flange refers to the distance of the flange protruding from the working surface of the fixed mold mounting plate after the pressure chamber is properly installed on the fixed mold mounting plate.

3.14 Injection Plunger Penetration

Injection plunger penetration refers to the maximum distance that the injection plunger is pushed out during mold opening, that is, the distance between the end of ejection and the end of the injection plunger to the working surface of the fixed mold mounting plate.

3.15 Accumulator

Accumulator refers to a container for storing liquid and gaseous pressure media in a hydraulic pipeline.

NOTE. the pressurized liquid compresses the gas in the container; during operation, the gas expands and stores energy output, which serves as a supplement to the liquid power.

3.16 Intensification

Intensification utilizes a difference in piston area or an accumulator with a higher pressure to make the generated fluid pressure in the injection cylinder higher than the system pressure.

3.17 Injection Pressure, Displacement-time Curve

Injection pressure, displacement-time curve refers to a curve that reflects the relations among injection pressure, injection plunger displacement and time, as it is shown in

Figure 1.

3.18 Slow Injection

Slow injection refers to the movement process of the injection plunger from the initial position to when the liquid metal reaches the fast injection transition point.

3.19 Fast Injection

Fast injection refers to the process, in which, the injection plunger quickly fills the cavity with liquid metal after the end of the slow injection.

3.20 Slow Injection Speed

Slow injection speed refers to the average speed of the injection plunger during the slow injection process.

3.21 Fast Injection Speed

6.1.2 The die casting machine shall have manual, semi-automatic and automatic working modes.

6.1.3 The movement of the moving parts shall be correct, stable and reliable. When the hydraulic system pressure is 25% of the rated value, there shall be no crawling, jamming and obvious impact (except for the mold adjustment action).

6.1.4 The hydraulic system and hydraulic components shall comply with the relevant stipulations of GB/T 3766 and GB/T 7935.

6.1.5 The electrical system shall comply with the relevant stipulations of GB 5226.1-

2008.

6.1.6 The pneumatic system shall comply with the relevant stipulations of GB/T 7932.

6.1.7 The die casting machine shall have designations and plates indicating the operation, lubrication and safety of the hydraulic and pneumatic systems. The contents and markings of the designations and plates shall be correct and comply with the stipulations of relevant standards. The plates shall comply with the stipulations of GB/T

13306.Distinct factory names and trademarks are allowed to be inlaid and cast on the die casting machine.

6.1.8 The die casting machine shall have a reliable centralized lubrication system, and detection functions and sound-light alarms.

6.1.9 The injection cylinder of the die casting machine shall have a sensor interface for process parameter testing.

6.1.10 When the hydraulic system is continuously working, the temperature of the working fluid shall not exceed 55 °C. When exceeding the above-mentioned temperature, it shall automatically alarm.

6.1.11 The working fluid medium shall comply with the stipulations of technical documents. The cleanliness of the hydraulic system of the die casting machine shall comply with the stipulations of GB/T 31562; the cleanliness code is 22/19.

6.1.12 After assembly, the regulating valve stem of each control mechanism shall be flexible, reliable and correctly positioned.

6.1.13 Cast parts with pressure-bearing channels shall undergo a pressure test; the test pressure is 1.5 times the rated pressure and the pressure holding time is 3 min.

There shall be no abnormal phenomena, such as. leakage and damaged parts, etc.

6.1.14 The technical documents provided along with the die casting machine shall at least include instructions for use, certificate of conformity and packing list. The instructions for use shall comply with the stipulations of GB/T 9969.

6.1.15 The energy consumption of the die casting machine shall comply with the

6.7.1 Before load running, the die casting machine shall receive an idle running test.

6.7.2 Under normal working conditions, carry out a physical die casting test. During the test, the various parameters shall comply with the design requirements.

6.7.3 For each injection, the pressure drop of the accumulator shall not exceed 10% of the working pressure.

6.7.4 During the process of physical die casting, the requirements specified in 6.6 shall be satisfied.

6.7.5 For a die casting machine with closed-loop control performance, under the state

of stable operation, the die casting speed control error shall be not greater than 5% of the set value.

6.7.6 For a die casting machine with closed-loop real-time control performance, under

the state of stable operation, the die casting speed control error shall be not greater than 2% of the set value.

7.1 Inspection of Routine Items

7.1.1 During the inspection of parameters and dimensions, the parameters

represented by linear dimensions are generally and directly measured with corresponding measuring tools and may also be detected with special detection devices.

7.1.2 The mold clamping force is detected by a special mold clamping force detection device.

7.1.3 The precision of the die casting machine shall comply with the stipulations of

Chapter 5.

7.1.4 The once dry cycle time is detected with a stopwatch, and its reading shall be the time interval from the moment when the actuator starts to move to the time that it stops.

7.1.5 The noise shall be determined in accordance with the stipulations of GB/T 25371.

7.2 Determination of Cleanliness

The cleanliness of the hydraulic system shall be determined in accordance with the stipulations of GB/T 31562.

7.3 Determination of Max Dry Injection Speed

7.3.1 Determination conditions

The determination conditions are as follows.

a) Accumulator pressure. the system working pressure;

b) Oscilloscope. time scale 0.002 s.

7.3.2 Determination

In accordance with the determined pressure, displacement-time curve (see Figure 1), on a stroke after the rapid starting point and before the end point, respectively minus

10%, calculate the average speed.

7.4 Determination of Closed-loop Control Speed Error

7.4.1 Determination conditions

The determination conditions are as follows.

a) Accumulator pressure. the system working pressure;

b) Oscilloscope. time scale 0.002 s.

7.4.2 Determination

Set a slow speed of 0.3 m/s and a fast speed of 3 m/s. Under the state of stable operation, the number of samplings shall be no less than 10.

7.5 Determination of Injection Force and Set Pressure Time

7.5.1 Determination conditions

The determination conditions are as follows.

a) Injection speed. 3 m/s ± 0.2 m/s for the horizontal cold-chamber diecasting machine; 2 m/s ± 0.2 m/s for the vertical cold-chamber diecasting machine;

b) Accumulator pressure. the system working pressure;

c) Oscilloscope. time scale 0.002 s;

d) The oil circuit connecting the sensor cannot be damped.

7.5.2 Determination of injection force

On the determined pressure, displacement-time curve (see Figure 1), read the intensification pressure stationarity value, then, calculate and determine it through the inner diameter of the injection cylinder.

7.5.3 Determination of set pressure time

injection performance and cleanliness.

8.2 Type Inspection

8.2.1 Under the following circumstances, the die casting machine shall receive type inspection.

a) Trial production of new products or trial production and model appraisal of old products transferred to another factory for production;

b) When the products undergo significant changes in design, process and materials;

c) During normal production, an inspection shall be carried out at regular intervals, or periodically after a certain output has been accumulated;

d) When the production has been suspended for more than one year, then, resumed;

e) When the national quality supervision institution proposes a request for type inspection.

8.2.2 The number of model machines for the type inspection shall be determined in accordance with the production batch. If the batch is within 10 sets, 1 set shall be randomly inspected; if the batch is greater than 10 sets, 2 sets shall be randomly inspected.

8.2.3 The type inspection shall cover all items in Chapter 6, and all the inspection items shall be qualified.

9.2 The packaging, marking, transportation and storage of the die casting machine

shall comply with the relevant stipulations of JB/T 8356.1 and GB/T 191.

9.3 The pictorial markings for the packaging, storage and transportation shall comply with the stipulations of railway, highway, waterway transportation and mechanized loading.

9.4 In accordance with the requirements of the contract, the product may be simply packaged or unpackaged.

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