JPH09314300A - Die casting machine and die casting method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely prevent the production of a casting having a blow hole by injecting molten metal into a cavity after perfectly replacing the air in the cavity with active gas. SOLUTION: A die casting machine is provided with the cavity 40 formed in dies 23, an injection device for injecting molten metal into the cavity 41, an active gas supplying device for supplying the active gas into the cavity 41, an air vent 43 communicated with the cavity 41 and having an opening hole 45 in the dies 23, a sensor part 49 for detecting the active gas leaked from the opening hole 45 at the position corresponding to the opening hole 45 of the air vent 43 and a sensor part operating means for operating the sensor part 49 from the position corresponding to the opening hole to a retracting position at the time of detecting the active gas by the sensor part 49.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a die casting machine and a die casting method, and particularly for producing a casting of aluminum or zinc alloy by injecting a molten metal in a state where the air in the cavity is replaced with an active gas such as oxygen. The present invention relates to a die casting machine and a die casting method.

[0002]

2. Description of the Related Art Usually, when casting is made of aluminum or zinc alloy, a die casting method is used in which a molten metal in a sleeve is extruded by a plunger tip provided at the tip of an injection rod and injected into a cavity. Since the inert gas such as nitrogen existing in the sleeve and the cavity does not react with the molten metal, it causes porosity in the casting and significantly deteriorates the quality of the casting. So in recent years,
A die casting method is used in which the air in the cavity is replaced with an active gas such as oxygen to produce a casting of aluminum or a zinc alloy. This die casting method is called the PF die casting method.

In the PF die casting method, an active gas supply device feeds an active gas into the cavity to replace the air in the cavity with the active gas. Then, the molten metal is injected into the cavity to react the active gas with the molten metal to prevent the formation of pores in the casting. This die casting machine is provided with a timer for measuring the time from when the active gas supply device starts to operate. In the die casting machine, the amount of active gas supplied to the cavity is taken into consideration, the time for which the cavity is filled with the active gas is predicted, and after this time is measured by a timer, the molten metal is injected into the cavity by the plunger tip.

[0004]

However, since the cavities have different shapes and sizes according to the castings to be manufactured, the time for which the cavities are filled with active gas varies, and only the time is measured by the timer. It is difficult to accurately determine whether or not the gas is filled with active gas. Therefore, before the air in the cavity is completely replaced with the active gas, the molten metal may be injected into the cavity, resulting in a cast product having pores.
In addition, the time to fill the cavity with active gas must be predicted according to the shape and size of the cavity, and the time setting from the activation of the active gas supply device to the start of the injection device must be changed. There is also the problem of having to do so. Furthermore, there is a possibility that an accident may occur in which a casting is produced without the active gas being supplied because the passage of the active gas supplied to the cavity is blocked or the active gas supply device is out of order. is there.

The present invention has been made by paying attention to the above-mentioned conventional problems. It is possible to form a casting having pores by completely replacing the air in the cavity with the active gas and then injecting the molten metal into the cavity. It is possible to prevent reliably, and it is not necessary to change the time setting from the activation of the active gas supply device to the start of the operation of the injection device, and there is no risk of accidents in which castings are produced without active gas being supplied. An object of the present invention is to provide a die casting machine and a die casting method capable of completely preventing the occurrence.

[0006]

According to a first aspect of the present invention, there is provided a cavity formed in a mold, an injection device for injecting a molten metal into the cavity, and an active gas supply device for supplying an active gas to the cavity. An air vent communicating with the cavity and having an opening in the mold; and a sensor section for detecting active gas leaking from the opening through the air vent from the cavity at a position corresponding to the opening of the air vent. The die casting machine is provided with a sensor unit operating means for operating the sensor unit to a retracted position from a position corresponding to the opening when an active gas is detected. Specifically, the molten metal is aluminum, zinc alloy, or the like.

According to a second aspect of the present invention, in the first aspect, there is provided an injection device drive command means for driving the injection device so that the molten metal is injected into the cavity when the sensor portion retracts from the opening. It is a die casting machine.

According to the third aspect of the present invention, an active gas supply step of supplying an active gas to the cavity of the mold by an active gas supply device provided in a die casting machine for producing a casting,
An active gas detection step of detecting an active gas that leaks from the opening of the air vent from the cavity through an air vent by a sensor part, and when the sensor part detects the active gas by the active gas detection step, the sensor part is opened to the opening. The die casting method is characterized by having a sensor part withdrawal step that moves from a corresponding position to a withdrawal position, and a molten metal injection step of injecting molten metal into the cavity by an injection device.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows a die casting machine 1 according to an embodiment of the present invention. This die casting machine 1
Manufactures aluminum castings. Reference numeral 3 indicates a base, and a pair of fixed plates 5 and 7 are attached to the base 3 so as to face each other. Tie bars 9 are inserted into and fixed to the four corners of the fixed plates 5 and 7, respectively.

A movable plate 11 is slidably provided on the tie bar 9, and the movable plate 11 is a sliding plate 13 of the base 3.
It is installed in. A mold clamping cylinder 15 is attached to the stationary platen 5, and a guide bar 17 is connected to a piston rod of the mold clamping cylinder 15.
The tip of 7 is connected to the movable plate 11. The mold clamping cylinder 15 moves the movable platen 11 toward and away from the fixed platen 7.

A female die 19 is attached to the front surface of the movable platen 11, and a male die 21 is attached to the front surface of the fixed platen 7. The female die 19 and the male die 21 face each other. The female die 19 and the male die 21 form a die 23. The mold 23 will be described in detail with reference to FIG. On the front surface of the female die 19, there is provided a convex portion 25 in which a flow path (not shown) through which the molten metal passes is formed. The flow path of this convex portion 25 communicates with the cavity concave portion 29 via the flow channel concave portion 27. There is. An air vent recess 31 is provided in the cavity recess 29.
, And the air vent recess 31 extends to the upper surface of the female die 19. A plurality of uneven portions 24 are provided in the air vent recess 31. Holes 33 are formed in the four corners of the female die 19, and elongated holes 20 are formed in the front surface of the female die 19.

A through hole 35 is formed in the male die 21 at a position corresponding to the convex portion 25. The flow path recess 28 communicates with the through hole 35, and the flow path recess 28 communicates with the cavity recess 30. An air vent recess 32 communicates with the cavity recess 30.
2 extends to the upper surface of the male die 21. A plurality of uneven portions 26 are provided in the air vent recess 32. The flow path recesses 27 and 28, the cavity recesses 29 and 30, the air vent recesses 31 and 32, and the concavo-convex portions 24 and 26 are located so as to face each other. Further, on the front surface of the male die 21, a pin 37 is provided at a position corresponding to the hole 33 and the long hole 20.
And a pin 22 are provided respectively.

When the female die 19 and the male die 21 are closed, the flow path recesses 27, 28 and the cavity recesses 29, 30 are closed.
And the air vent recesses 31 and 32, respectively,
The flow path 39, the cavity 41, and the air vent 43 are formed. Further, an opening 45 of the air vent 43 is formed on the upper surface of the mold 23. The concavo-convex portions 24 and 26 are combined to prevent the molten metal from blowing out of the opening 45 through the air vent 43.

An actuator 47 is provided on the upper surface of the male die 19 as a sensor section operating means. An active gas detection sensor 49 as a sensor unit for detecting oxygen is attached to the actuator 47. The active gas detection sensor 49 is opened by the actuator 47.
And a position retracted from the opening 45. The actuator 47 is connected to the controller 51, and the controller 51 is connected to the control panel 52. The controller 51 controls the operation of the actuator 47.

An extruding cylinder 53 is attached to the rear surface of the movable platen 11, and a rod member 55 is connected to the piston rod of the extruding cylinder 33. The tip of the rod member 55 penetrates the female die 19. Reference numeral 57 indicates a hydraulic cylinder, which is the base 3
It is attached to a base frame 59 fixed to the. A tie-lot-shaped or frame-shaped connecting member 61 is attached to the hydraulic cylinder 57, and the connecting member 61 is connected to the back surface of the stationary platen 7.

On the piston rod of the hydraulic cylinder 57,
The injection rod 63 is connected, and a plunger tip 65 is provided at the tip of the injection rod 63. The switching valve (not shown) of the hydraulic cylinder 57 is an injection device drive command means (not shown) provided on the control panel 52, and the controller 51.
, The controller 51 is actuated, and the active gas detection sensor 49 is opened by the actuator 47.
The piston rod of the hydraulic cylinder 57 is set to project when retracted from. Sleeve 67 is fixed plate 7
The sleeve 67 is fitted in the through hole 35 of the male die 21. The plunger tip 65 provided at the tip of the injection rod 63 enters the sleeve 67. The injection device 69 includes a hydraulic cylinder 57, an injection rod 63, a plunger tip 65 and a sleeve 67.

The die casting method using the die casting machine 3 will be described. The active gas detection sensor 49 is moved to a position corresponding to the opening 45 of the air vent 43 by the actuator 47. Hydraulic pressure is supplied to the mold clamping cylinder 15, the piston rod of the mold clamping cylinder 15 projects, the movable platen 11 moves toward the fixed platen 7, the pin 37 into the hole 33, and the pin 22 into the elongated hole 20. Each is fitted, and the convex portion 25 is fitted in the through hole 35, and the female mold 19 and the male mold 21 are closed. The active gas supply step will be described. Oxygen as an active gas is supplied to the cavity 41 by an active gas supply device (not shown) to replace the air in the cavity 41 with oxygen.

The active gas detection step will be described. When oxygen is further supplied to the cavity 41 filled with oxygen, the oxygen passes through the air vent 43 and is ejected from the opening 45, and the ejected oxygen is detected by the active gas detection sensor 49. The sensor part retracting step will be described. When the active gas detection sensor 49 detects the ejected oxygen, the controller 51 operates, the actuator 47 operates, and the active gas detection sensor 49 retreats from the position corresponding to the opening 45.

The molten metal injection step will be described. When the active gas detection sensor 49 retreats from the opening 45, the control panel 52
The injection device command drive circuit is operated, the switching valve of the hydraulic cylinder 57 is operated, the piston rod of the hydraulic cylinder 57 is projected, and the molten metal in the sleeve 67 is pushed out by the plunger tip 65. The molten metal extruded from the sleeve 67 passes through the flow path formed in the convex portion 25, the flow path 39, and is injected into the cavity 41. The injected molten metal reacts with oxygen and accumulates in the cavity 41. Since the active gas detection sensor 49 is retracted from the position corresponding to the opening 45, even if the molten metal blows out from the opening 45, it is possible to prevent the active gas detection sensor 49 from hitting the active gas detection sensor 49. Then, the plunger tip 65 is advanced together with the injection rod 63 by a boost mechanism (not shown), and the sleeve 67 is moved.
The molten metal in the cavity 41 is pressed to apply pressure to the molten metal in the cavity 41.

After the molten metal in the cavity 41 is solidified,
The piston rod of the mold clamping cylinder 15 retracts, the movable platen 11 moves in the direction away from the fixed platen 7, and the mold 23 is opened. Then, the piston rod of the pushing cylinder 53 projects, the casting is pushed out by the rod member 55, and the casting is taken out by a take-out robot (not shown). The die casting machine 1 repeats the above-mentioned operation to manufacture a casting.

As described above, in the die casting machine 1, since it is directly detected that the cavity is filled with oxygen,
Unlike the conventional example, it is possible to reliably detect that the cavity 41 is filled with oxygen. Therefore, it is possible to completely prevent the formation of pores in the casting, and it is possible to keep the quality of the casting constant. Further, it becomes possible to prevent the casting from being manufactured without supplying oxygen to the cavity 41. Furthermore, regardless of the shape and size of the cavity, the molten metal is set to be injected after it is always filled with oxygen, so the active gas supply device operates depending on the shape and size of the cavity. There is no need to change the setting of the time from when the injection device 69 starts to operate.

Although the embodiment of the present invention has been described in detail above, the specific configuration is not limited to this embodiment, and there are design changes and the like within the scope not departing from the gist of the present invention. Also included in the present invention.

[0023]

As described above, according to the present invention, it is possible to surely prevent the molten metal from being injected into the cavity after the air in the cavity has been completely replaced with the active gas, thereby forming a casting having pores. Become. Further, it is not necessary to change the time setting from the activation of the active gas supply device to the activation of the injection device one by one. It becomes possible to completely prevent the occurrence of an accident in which a casting is produced without being supplied with active gas. Further, when the molten metal is injected into the cavitity, the sensor part for detecting the active gas is always at the position retracted from the opening, so that the molten metal blown out from the opening is caught by the active gas detection sensor and the sensor part is not damaged. Can be prevented.

[Brief description of drawings]

FIG. 1 is a sectional view of a die casting machine according to an embodiment of the present invention.

FIG. 2 is a perspective view of a die of the die casting machine according to the embodiment of the present invention.

FIG. 3 is a side view for explaining the operation of the sensor mounted on the die casting machine according to the embodiment of the present invention.

FIG. 4 is a side view for explaining the operation of the sensor mounted on the die casting machine according to the embodiment of the present invention.

[Explanation of symbols]

 1 Die Casting Machine 3 Base 5, 7 Fixed Plate 9 Tie Bar 11 Movable Plate 13 Sliding Plate 15 Mold Clamping Cylinder 17 Guide Bar 19 Female Mold 20 Long Hole 21 Male Mold 22 Pin 23 Mold 24, 26 Concavo-convex 25 Convex 27 , 28 Flow path concave part 29, 30 Cavity concave part 31, 32 Air vent concave part 33 Hole 35 Through hole 37 Pin 39 Flow path 41 Cavity 43 Air vent 45 Opening 47 Cylinder 49 Active gas detection sensor 51 Controller 52 Control panel 53 Extrusion cylinder 55 Rod member 57 Hydraulic cylinder 59 units Frame 61 Connecting member 63 Injection rod 65 Plunger tip 67 Sleeve 69 Injection device

Claims (3)

[Claims] 1. A cavity formed in a mold, an injection device for injecting a molten metal into the cavity, an active gas supply device for supplying an active gas to the cavity, and an outside of the mold communicating with the cavity. An air vent having a continuous opening, at a position corresponding to the opening of the air vent, passing through the air vent from the cavity, a sensor unit for detecting active gas leaking from the opening, and when the active gas is detected by the sensor unit, A die casting machine, comprising: a sensor unit operating means for operating the sensor unit from a position corresponding to the opening to a retracted position. 2. A die casting machine according to claim 1, further comprising injection device drive command means for driving the injection device so that the molten metal is injected into the cavity when the sensor portion is retracted from the opening. 3. An active gas supply step of supplying an active gas to a cavity of a mold by an active gas supply device provided in a die casting machine for making a casting, and an activity of leaking from an opening of the air vent through the air vent from the cavity. An active gas detection step of detecting gas with a sensor unit,
When the sensor section detects an active gas in the active gas detection step, the sensor section retracting step in which the sensor section moves to a retracted position from the position corresponding to the opening, and the sensor section in the sensor section retracting step A molten metal injection step of injecting a molten metal into the cavity by an injection device when the molten metal is withdrawn from the opening.