JP6115504B2 - Die casting apparatus and die casting method - Google Patents

Description

  The present invention relates to a technique of a die casting apparatus and a die casting method.

  Die casting is a mold casting method in which molten metal (aluminum, zinc, magnesium, etc.) is injected into a mold by an injection device at a high pressure, the molten metal is rapidly solidified in the mold, and is taken out from the mold as a die cast product. In die casting, there is a problem of die casting failure in which a cast hole (cavity inside the die cast product) is generated due to a decrease in the density of the die cast product (particularly a thick portion).

  In order to solve such a die casting defect, in a die casting apparatus, a die is provided with a push pin structure, and after injection filling by the injection device, the thick part of the die cast product is pressed to improve the density of the thick part. Nest generation is reduced (push pin pressing structure).

  However, in the above-described die casting apparatus with a pressing pin pressurization structure, although the density of the portion pressed with the pin is improved, the pressurizing force due to the presspin pressurizing structure does not act on the other portions. The density cannot be improved.

  In order to solve such a die casting defect, a method (surface pressurization method) in which a die is clamped after injection filling with molten metal and the pressure applied to the die casting product is uniformed (for example, Patent Document 1) has been studied. ). However, in such a surface pressure type die casting apparatus, since the section for accelerating the movable mold (acceleration running section) is after injection injection filling of the molten metal when the mold is clamped, after completion of the molten metal filling and before solidification of the molten metal Insufficient pressure can be applied to the die-cast product.

JP 2002-059252 A

  The problem to be solved by the present invention is to provide a die-casting apparatus and a die-casting method that can pressurize the entire die-cast product and improve the density of the entire die-cast product.

  The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described.

  That is, in claim 1, a die casting apparatus for injecting and filling molten metal into a mold, the mold clamping apparatus moving the mold in a mold clamping direction at a predetermined set speed, and the mold Control means for controlling the mold clamping timing by the clamping device is provided so that the mold clamping speed by the mold clamping device becomes the set speed before the injection filling of the molten metal into the mold is completed. The mold clamping timing by the mold clamping device is controlled.

  According to a second aspect of the present invention, the die casting apparatus includes a filling start detection sensor that detects that the filling of the molten metal into the mold is started, and the control means includes the filling start detection sensor disposed on the mold. When it is detected that the filling of the molten metal is started, the mold clamping by the mold clamping device is started.

  The die casting method according to claim 3, wherein the molten metal is injected and filled into a mold, and the molten metal filled in the mold is pressurized by clamping the mold at a predetermined set speed, Before the injection filling of the molten metal into the mold is completed, the mold clamping timing of the mold is controlled so that the mold clamping speed of the mold becomes the set speed.

  According to the die-casting apparatus and the die-casting method of the present invention, the entire die-cast product can be pressurized and the density of the entire die-cast product can be improved.

The schematic diagram which showed the structure of the die-casting apparatus. The flowchart which showed the flow of the die-casting method. Similarly time chart.

The configuration of the die casting apparatus 100 will be described with reference to FIG.
In addition, in FIG. 1, the structure of the die-casting apparatus 100 is typically represented by the side view which made the partial cross section view. Moreover, the broken line of FIG. 1 represents the electric signal line.

  The die casting apparatus 100 is an embodiment according to the die casting apparatus of the present invention. The die casting apparatus 100 injects molten metal (aluminum, zinc, magnesium, etc.) into the mold 30 by the injection apparatus 20 at a high pressure, and rapidly solidifies the molten metal (molten metal) in the mold 30. This is a die casting device to be taken out as a die-cast product.

  The die casting apparatus 100 includes an injection device 20, a mold 30, a mold clamping device 40, and a controller 50 as a control means.

  The injection device 20 is a device for injecting and filling molten metal into the mold 30. The injection device 20 includes an injection plunger 21 and an injection sleeve 22. In the injection device 20, the molten metal supplied into the injection sleeve 22 from the molten metal supply port 23 is pushed out by the injection plunger 21 sliding in the injection sleeve 22 and injected toward the mold 30.

  The mold 30 is formed with a cavity C that is the shape of a die-cast product. The mold 30 includes a fixed mold 31, a movable mold 32, and a platen 35. The fixed mold 31 is fixed to the platen 35. The movable mold 32 is fixed to the auxiliary platen 46 of the mold clamping device 40, and together with the auxiliary platen 46, the direction close to the fixed mold 31 (the mold clamping direction) and the direction away from the fixed mold 31 (the mold opening direction). It is configured to be movable.

  The mold 30 is provided with a filling start detection sensor 51 and a filling completion detection sensor 52. The filling start detection sensor 51 is disposed on the runner of the mold 30 (the path that guides the molten metal to the cavity C). The filling completion detection sensor 52 is disposed in the cavity C of the mold 30 at a position farthest from the gate (a port through which molten metal is injected in the cavity C). The filling start detection sensor 51 and the filling completion detection sensor 52 are connected to the controller 50.

  In the present embodiment, the filling completion detection sensor 52 is disposed at the position farthest from the gate in the cavity C of the mold 30, but is not limited thereto. The filling completion detection sensor 52 shall be arrange | positioned in arbitrary positions based on a product shape or a hot water circumference.

  The mold clamping device 40 is a device that performs mold clamping by moving the movable mold 32 in the mold clamping direction, and pressurizes the molten metal filled in the cavity C. The mold clamping device 40 includes a drive motor 55, a ball screw 41, wedge plates 42 and 42, wedge blocks 43 and 43, a platen 45, and an auxiliary platen 46.

  The drive motor 55 is connected to the controller 50 and drives the ball screw 41. The ball screw 41 moves the wedge blocks 43 and 43 so as to be close to or away from each other in the vertical direction (direction perpendicular to the mold clamping direction and the mold opening direction).

  One of the wedge plates 42 and 42 is fixed to the platen 45, and the position in the mold clamping and mold opening direction is fixed. The other side is fixed to the auxiliary platen 46 and can be moved in the mold clamping and mold opening directions.

  The wedge plates 42 and 42 abut against the wedge blocks 43 and 43, and the wedge block 43 on the auxiliary platen 46 side moves away from the wedge block 43 on the platen 45 side when the wedge blocks 43 and 43 move so as to be close to each other. When the wedge blocks 43 and 43 are moved away from each other, the wedge block 43 on the auxiliary platen 46 side moves in the direction closer to the wedge block 43 on the platen 45 side.

  With such a configuration, in the mold clamping device 40, when the ball screw 41 is driven by the drive motor 55 and the wedge blocks 43 and 43 move so as to be close to each other in the vertical direction, the wedge block 43 on the auxiliary platen 46 side. Is moved away from the wedge block 43 on the platen 45 side, and the auxiliary platen 46 and the movable mold 3 are moved in the mold clamping direction.

  Further, in the mold clamping device 40, the movement of the wedge plates 42 and 42 in the vertical direction by the ball screw 41 is moved by the wedge plates 42 and 42 and the wedge blocks 43 and 43 in the mold clamping and mold opening direction. Is converted to Here, in the mold clamping device 40, by setting the taper angle of the wedge plates 42 and 42 to be larger than the taper angle of the wedge blocks 43 and 43, the moving speed of the movable mold 3 relative to the moving speed of the wedge blocks 43 and 43 is set. It is possible to decelerate.

  Thereby, even if the moving amount of the movable die 3 in the mold clamping direction is a small size, the moving amount of the ball screw 41 can be increased, and the ball screw 41 can be prevented from being damaged. .

  The controller 50 is connected to a filling start detection sensor 51, a filling completion detection sensor 52, and a drive motor 55.

  The controller 50 has a function of detecting that the filling of the molten metal into the cavity C is started by the filling start detection sensor 51. The controller 50 has a function of detecting that the filling of the molten metal into the cavity C is completed by the filling completion detection sensor 52.

  Further, the controller 50 controls the drive motor 55 to control the moving speed of the movable mold 32 in the mold clamping direction (mold clamping speed V) to an appropriate speed, and the movement of the movable mold 32 in the mold clamping direction. It has a function of controlling the start timing appropriately.

  With such a configuration, in the die casting apparatus 100, the injection apparatus 20 injects and fills the molten metal into the cavity C of the mold 30, and the mold filling apparatus 40 applies the molten metal filled in the cavity C of the mold 30. Can be pressed.

The flow of the die casting process S100 will be described with reference to FIG.
In addition, in FIG. 2, the flow of die-casting process S100 is represented with the flowchart.

  The die casting process S100 is an embodiment according to the die casting method of the present invention. In the die casting process S100, the die casting apparatus 100 is used to inject molten metal (aluminum, zinc, magnesium, etc.) into the mold 30 by the injection apparatus 20 at a high pressure, and the molten metal is rapidly solidified in the mold 30. This is a mold casting process for taking out a die-cast product from the mold 30.

  In step S110, injection and filling of the molten metal into the mold 30 by the injection device 20 is started. At this time, the filling start detection sensor 51 detects the molten metal reaching the gate, and the controller 50 detects that the molten metal has passed through the gate by the detection of the molten metal by the filling start detection sensor 51, that is, filling of the molten metal into the cavity C is started. It is detected that

  When the controller 50 detects that the filling of the molten metal into the cavity C is started in step S110, the controller 50 controls the drive motor 55 in step S120, and the mold clamping device 40 moves the movable mold 32 in the mold clamping direction. Once started, clamping with the movable mold 32 is performed.

  That is, the start timing of the movement of the movable mold 32 in the mold clamping direction is controlled to the timing when the controller 50 starts filling the molten metal into the cavity C. The moving speed of the movable mold 32 by the drive motor 55 is set in the controller 50 in advance.

  The movable mold 32 that has started moving in the mold clamping direction in step S120 starts to move and then its moving speed increases. In step S130, the moving speed (clamping speed V) reaches the maximum speed Vm. . The maximum speed Vm is a speed preset in the controller 50 as the moving speed of the movable mold 32. Note that when the mold clamping speed V of the movable mold 32 reaches the maximum speed Vm, the filling of the molten metal into the cavity C has not yet been completed.

  The controller 50 controls the movement of the movable mold 32 so that the movable mold 32 moves at a predetermined moving speed set in advance, but the movable mold 32 starts to move due to the inertia of the movable mold 32 or the like. It takes a predetermined time until the set moving speed is reached.

  That is, the predetermined time is required until the mold clamping speed V reaches the maximum speed Vm after the movable mold 32 starts to move, and this predetermined time is referred to as an acceleration running time ta. The acceleration running time ta is determined by the magnitude of the driving force of the driving motor 55, the size of the mold 30, and the like.

  In step S140, the injection filling of the molten metal into the mold 30 by the injection device 20 is completed. At this time, the controller 50 detects that the filling of the molten metal in the cavity C is completed by the filling completion detection sensor 52. At this time, the movement of the movable mold 32 in the mold clamping direction is continued, and the mold clamping speed V is maintained at the maximum speed Vm.

  Here, as a matter of special note, the controller 50 has the mold clamping speed V of the movable mold 32 by the mold clamping device 40 attains the maximum speed Vm at least when the filling of the molten metal into the cavity C in step S140 is completed. As described above, in consideration of the acceleration run-up time ta of the movable mold 32, the timing for starting the movement of the movable mold 32 in the mold clamping direction in step S120 is set.

  In the present embodiment, by setting the start timing of the movement of the movable mold 32 in the mold clamping direction to the timing when the filling of the molten metal into the cavity C is started, the filling of the molten metal into the cavity C is completed. The mold clamping speed V is set to the maximum speed Vm.

  In step S150, the controller 50 controls the drive motor 55 to stop the movement of the movable mold 32 and completes the mold clamping by the mold clamping device 40.

The effect | action of die-casting process S100 is demonstrated using FIG.
In addition, in FIG. 3, the effect | action of die-casting process S100 is represented with the time chart.

  In the upper part of FIG. 3, regarding the behavior of the injection device 20, the horizontal axis represents time t, and the vertical axis represents the sliding speed of the injection plunger 21 (injection speed v). In the lower part of FIG. 3, regarding the behavior of the movable mold 32, the horizontal axis represents time t and the vertical axis represents the moving speed (clamping speed V) of the movable mold 32.

  First, injection filling of the molten metal into the mold 30 by the injection device 20 is started (filling start). At the start of injection filling of the molten metal into the mold 30, the injection speed v is controlled to be low.

In step S110 and step S120, when the filling start detection sensor 51 detects that the filling of the molten metal into the cavity C is started, the drive motor 55 is controlled, and the mold clamping device 40 controls the mold clamping direction of the movable mold 32. The movement to (1) begins.
At the start of movement of the movable mold 32, the injection speed v is still controlled at a low speed.

  The movable mold 32 that has started to move in the mold clamping direction starts moving, and its mold clamping speed V increases. In step S130, the mold clamping speed V reaches the maximum speed Vm.

  Further, the control of the injection speed v by the controller 50 is switched from the low speed to the high speed in the section from the start of movement of the movable mold 32 to the mold clamping speed V reaching the maximum speed Vm. The sliding speed (injection speed v) of the injection plunger 21 reaches the maximum speed at a timing equivalent to the timing at which the mold clamping speed V reaches the maximum speed Vm, for example.

  In step S140, the injection filling of the molten metal into the mold 30 by the injection device 20 is completed, and the filling completion detection sensor 52 detects that the filling of the molten metal in the cavity C is completed (filling is completed). Note that when the injection filling of the molten metal into the cavity C is completed, the mold clamping speed V of the movable mold 32 is maintained at the maximum speed Vm.

  As described above, when the filling of the molten metal into the cavity C is completed, the mold clamping speed V of the movable mold 32 reaches the maximum speed Vm, so that the molten metal filled in the cavity C is solidified before the molten metal is solidified. A sufficient pressing force can be applied to.

  When the molten metal filled in the cavity C is sufficiently pressurized, the air entrained in the molten metal is crushed, and the density of the die-cast product after solidification can be improved.

  In step S150, the drive motor 55 is controlled to stop the movement of the movable mold 32, and the mold clamping by the mold clamping device 40 is completed (mold clamping is completed).

The effects of the die casting apparatus 100 and the die casting process S100 will be described.
According to the die casting apparatus 100 and the die casting process S100, before the molten metal filled in the cavity C is solidified, the molten metal can be pressurized as a whole, and the die cast product obtained by solidifying the molten metal can be obtained. The density can be improved overall.

  That is, generally, there is a variation in the timing at which the molten metal is supplied from the injection sleeve 22 to the cavity C, and the timing at which the injection filling of the molten metal into the cavity C is completed is different for each shot. In this case, if the movement start timing of the movable mold 32 in the mold clamping direction is fixed, the completion timing of the molten metal filling and the mold clamping timing by the movable mold 32 are shifted for each shot, and the finished quality of the die cast product is improved. It is difficult to keep it constant.

  However, in the die casting apparatus 100 and the die casting process S100 in the present embodiment, a filling start detection sensor 51 that detects the start of filling of the molten metal into the cavity C and a filling completion detection that detects the completion of filling of the molten metal into the cavity C. The sensor 52 is provided, and the movement of the movable mold 3 in the mold clamping direction is started in accordance with the molten metal detection timing by the filling start detection sensor 51.

  Thereby, the mold clamping timing by the movable mold 32 can be accurately aligned with the completion timing of the molten metal filling, and the finished quality of the die cast product can be kept constant.

  In the die casting apparatus 100 and the die casting process S100, the movement start timing of the movable mold 32 in the mold clamping direction is set such that the mold clamping speed V reaches the maximum speed Vm before the filling of the molten metal into the cavity C is completed. So that it is controlled.

  Therefore, there is no acceleration run-up section ta of the mold clamping speed V from the completion of the filling of the molten metal to the solidification of the molten metal, and before the molten metal filled in the cavity C solidifies. A sufficient pressing force can be applied to the molten metal, and the density of the die-cast product after solidification can be improved.

20 injection device 30 mold 32 movable type 40 mold clamping device 50 controller (control means)
51 Filling start detection sensor 52 Filling completion detection sensor 100 Die casting apparatus

Claims (2)

A die casting apparatus for injecting and filling molten metal into a mold,
A mold clamping device for moving the mold in a mold clamping direction at a predetermined set speed and clamping the mold;
Control means for controlling mold clamping timing by the mold clamping device;
A filling start detection sensor for detecting that filling of the molten metal into the mold is started;
With
The control means includes
When the filling start detection sensor detects that the filling of the molten metal into the mold is started, the mold clamping by the mold clamping device is started , and before the injection filling of the molten metal into the mold is completed, Controlling the mold clamping timing by the mold clamping device so that the mold clamping speed by the mold clamping device becomes the set speed,
Die casting equipment. The molten metal was injected and filled into a mold, a has been the melt chaos holder Ikast casting method filling the mold on the mold by the mold clamping at a predetermined set speed,
When it is detected that filling of the molten metal into the mold is started, mold clamping is started , and before the injection filling of the molten metal into the mold is completed, the mold clamping speed is set to the set speed. To control the mold clamping timing of the mold,
Die casting method.

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