JP4436104B2 - Die casting machine - Google Patents

Description

  The present invention relates to a die casting machine.

In a molding apparatus such as a die casting machine or a plastic injection molding machine, a molding material is injected and filled into a mold while the mold is clamped.
In order to prevent the molding material from leaking from the mold dividing surface, the mold is clamped by a mold clamping device. For example, a toggle mechanism type, a direct pressure type, a composite type, etc. are known. ing.
The toggle mechanism type mold clamping device is suitable for generating and holding a large mold clamping force at the mold clamping limit.
The direct pressure type mold clamping apparatus performs opening / closing and mold clamping of a mold by a hydraulic cylinder, as disclosed in, for example, Patent Document 1 and the like.
For example, as disclosed in Patent Documents 2 to 4 and the like, the composite mold clamping device includes an actuator that opens and closes a mold by moving a moving plate with respect to a fixed plate, and mold clamping. The actuator to perform is provided separately.
JP-A-63-94808 Japanese Patent Laid-Open No. 10-52841 Japanese Utility Model Publication No. 5-7419 Japanese Utility Model Publication No. 5-49330

By the way, among the mold clamping devices described above, the toggle type mold clamping device can generate a very large mold clamping force at the mold clamping limit, but the mold clamping force is determined by the mechanical structure. When the mold clamping force rises due to thermal expansion of the mold, there is a disadvantage that correction operation of the mold clamping force is necessary or real-time control of the mold clamping force is difficult.
In addition, a die casting machine that injects and fills a metal melt into a cavity requires an injection speed that is ten times as high as that of a plastic injection molding machine. Therefore, when an injection surge occurs, a very large clamping force is required. . If the mold is always clamped with a large clamping force, there is a disadvantage that the mold is easily damaged.
With direct pressure and compound type clamping devices, if a mold opening force exceeding the rated clamping force occurs due to a surge during injection in the hydraulic circuit that generates the clamping force, the mold cannot be held and the mold cannot be held. Opening may cause burrs in the product.

  The present invention has been made in view of the above-described problems, and its purpose is to suppress damage to the mold, to stably generate an accurate mold clamping force, and to mold even if an injection surge occurs. An object of the present invention is to provide a die casting machine having a mold clamping rigidity that does not open.

  The die casting machine of the present invention controls a clamping cylinder that generates a clamping force for clamping a pair of molds, a hydraulic circuit that supplies hydraulic fluid to the clamping cylinder, and the hydraulic circuit. Control means for generating a necessary clamping force in accordance with the operation of an injection device for injecting and filling molten metal into the mold.

  Preferably, the die casting machine of the present invention has detection means for detecting a mold clamping force generated by the mold clamping cylinder, and the control means is based on the mold clamping force detected by the detection means. The mold clamping force generated by the mold clamping cylinder is feedback controlled.

  More preferably, the hydraulic circuit has sealing means for releasably sealing a cylinder chamber to which hydraulic fluid for generating a clamping force of the clamping cylinder is supplied.

  In the present invention, the mold clamping force generated by the mold clamping cylinder is changed according to the operation of the injection device. That is, the operation of the injection device of the die casting machine usually includes an injection process and a pressure increasing process. In the injection process, the operation is started at a low injection speed, and the molten metal is injected and filled into the mold by switching to a high injection speed. Then, after filling the mold with the molten metal, the process is switched to the pressure increasing step. The required mold clamping force varies depending on each operation of such an injection apparatus. The control means generates a necessary clamping force in accordance with each operation of the injection device.

According to the present invention, only the necessary minimum clamping force is applied to the mold, so that damage to the mold can be suppressed and the occurrence of burrs can be suppressed, and a cast product with stable quality can be obtained. It is done.
Further, according to the present invention, since the mold clamping force is controlled based on the hydraulic pressure of the hydraulic cylinder, it is possible to easily generate an accurate mold clamping force.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a side view showing a mechanical structure of a die casting machine according to an embodiment of the present invention. FIG. 2 is a horizontal sectional view of the die casting machine 1 shown in FIG. FIG. 1 partially includes a cross-sectional view. FIG. 2 includes a hydraulic circuit and a controller in addition to the mechanical structure of the die casting machine.
In FIG. 1, the die casting machine 1 includes an injection device 50 and a mold clamping device 70. As shown in FIG. 2, the die casting machine 1 includes a controller 90 and a hydraulic circuit 91 in addition to the injection device 50 and the mold clamping device 70.
The injection device 50 is an embodiment of the injection device of the present invention, the hydraulic circuit 91 is an embodiment of the hydraulic circuit of the present invention, and the controller 90 is an embodiment of the control means of the present invention.

The mold clamping device 70 is a so-called composite mold clamping device in which the mold is opened and closed by the moving mechanism 40 and the mold clamping cylinder 9 performs the mold clamping.
As shown in FIGS. 1 and 2, the mold clamping device 70 includes a stationary platen 3, a movable platen 4, a tie bar 7, a mold clamping cylinder 9, a moving mechanism 40, a half nut 20, and a contact member. 30 and a guide portion 35.

The fixed platen 3 is fixed on the base 2. The stationary platen 3 holds the stationary mold 5 on the front side. The fixed platen 3 is formed with a through hole 3h into which the tie bar 7 is inserted. The through holes 3h are formed at the four corners of the fixed platen 3, for example.
The movable platen 4 holds the movable mold 6 on the front surface (side facing the fixed platen 3). The movable platen 4 is provided on the base 2 so as to be movable in the mold opening direction A1 and the mold closing direction A2.

By closing the pair of molds of the fixed mold 5 and the movable mold 6, a cavity is formed between the fixed mold 5 and the movable mold 6.
Four tie bars 7 are provided, and one end of the tie bar 7 is supported by the moving board 4 so as to be movable. The tie bar 7 is supported horizontally along the mold opening direction A1 and the mold closing direction A2. A piston 8 is connected to one end of the tie bar 7, and both side portions of the piston 8 are fitted and inserted into support holes 4 a and 4 b formed in the moving plate 4. One end of the tie bar 7 is supported by the support holes 4a and 4b.
A serrated groove 7 a is formed at the free end, which is the other end of the tie bar 7.

The mold clamping cylinder 9 is formed inside the movable platen 4, and a piston 8 connected to the tie bar 7 is incorporated in the movable platen 4 so as to be movable. By supplying high-pressure hydraulic oil to the cylinder chamber of the mold clamping cylinder 9, a force acts between the moving plate 4 and the tie bar 7, and the moving plate 4 is driven with respect to the tie bar 7.
The movable platen 4 is movable with respect to the tie bar 7 within a movable range of the piston 8 connected to the tie bar 7, that is, within a stroke range of the mold clamping cylinder 9.
The mold clamping cylinder 9 is provided with a pressure sensor 80. The pressure sensor 80 detects the pressure of hydraulic oil in the mold clamping cylinder 9, that is, the mold clamping force generated by the mold clamping cylinder 9, and outputs a detection signal 80 s to the controller 90. The pressure sensor 80 is an embodiment of the mold clamping force detecting means of the present invention.

The moving mechanism 40 is built in the base 2 and includes a screw shaft 41, a support member 42, a servo motor 43, and a movable member 44.
The support member 42 rotatably supports one end portion of the screw shaft 41.
The other end of the screw shaft 41 is connected to the servo motor 43.
The screw shaft 41 is screwed into the movable member 44.
As shown in FIG. 2, the movable member 44 is fixed to both sides of the movable board 4.

  In the moving mechanism 40, by controlling the rotation of the servo motor 43, the screw shaft 41 rotates, and the rotation of the screw shaft 41 is converted into a linear motion of the movable member 44. Thereby, the movable board 4 is driven in the mold opening direction A1 or the mold closing direction A2.

The half nut 20 is disposed on the back surface of the through hole 3 h of the fixed platen 3. The half nut 20 has a groove (not shown) that meshes with the coupled groove 7 a of the tie bar 7.
The half nut 20 is opened and closed by a half nut opening / closing cylinder 21 shown in FIG. 2, and when the half nut 20 is closed and engaged (coupled) with the coupled groove 7 a of the tie bar 7, the tie bar 7 and the stationary platen 3 are connected. When the half nut 20 is opened, the connection between the tie bar 7 and the stationary platen 3 is released. In addition, since the half nut 20 is a well-known technique, detailed description is abbreviate | omitted.

The contact member 30 positions the tie bar 7 at a predetermined position when the free end 7b of the tie bar 7 contacts. This predetermined position is a position where the half nut 20 can be coupled to the coupled groove 7 a of the tie bar 7. The movement of the tie bar 7 is restricted by colliding with the contact member 30.
The contact member 30 is fixed to the back surface of the fixed platen 3 via a connecting member (not shown).

The injection device 50 includes a sleeve 51, a plunger 52, and an injection cylinder 56.
The sleeve 51 is provided on the back side of the fixed platen 3 and communicates with a cavity formed between the fixed mold 5 and the movable mold 6. A molten metal such as an aluminum alloy is supplied into the sleeve 51 through a supply port 51 a formed on the rear end side of the sleeve 51.

The plunger 52 includes a plunger tip 53 and a plunger rod 54. A plunger tip 53 is connected to the tip of the plunger rod 54, and the plunger tip 53 is fitted to the inner periphery of the sleeve 51.
The plunger rod 54 is connected to the piston rod 57 of the injection cylinder 56 by a coupling 55.
The position detector 98 detects the position of the plunger 52 and outputs a detection signal 98 s to the controller 90. The controller 90 recognizes the position and injection speed of the plunger 52 based on the detection signal 98s.

The injection cylinder 56 is driven by high pressure hydraulic oil, for example. When the molten metal is supplied to the sleeve 51, when the injection cylinder 56 is driven and the plunger 52 is advanced, the molten metal is injected and filled into the cavity formed between the fixed mold 5 and the movable mold 6. . When the molten metal is injected and filled into the cavity, the fixed mold 5 and the movable mold 6 are clamped to prevent the molten metal from leaking from the split surfaces of the fixed mold 5 and the movable mold 6.
The injection cylinder 56 is provided with a pressure sensor (not shown) for detecting the injection pressure, and the injection pressure detected by the pressure sensor is input to the controller.

The hydraulic circuit 91 supplies hydraulic oil from the hydraulic source 92 to the mold clamping cylinder 9 and discharges hydraulic oil from the mold clamping cylinder 9.
The hydraulic circuit 91 includes a pressure control valve 93, a direction control circuit 94, and a pilot check valve 95.

  In response to the control command 93s from the controller 90, the pressure control valve 93 adjusts the pressure of the hydraulic oil by returning a part of the high-pressure hydraulic oil supplied from the hydraulic source 92 to the tank TK. The supplied hydraulic oil is supplied to the direction control circuit 94.

  The direction control circuit 94 is connected to the pipe line on the hydraulic source 92 side and the two cylinder chambers 9a and 9b of the mold clamping cylinder 9, and receives a control command 94s from the controller 90 and receives pressure from the hydraulic source 92 side. The adjusted hydraulic fluid is selectively supplied to one of the two cylinder chambers 9a and 9b of the mold clamping cylinder 9. The direction control circuit 94 includes a plurality of control valves and the like. A mold clamping force is generated by supplying high-pressure hydraulic oil to the cylinder chamber 9b through the direction control circuit 94.

The pilot check valve 95 is provided in the middle of a pipe line connecting the direction control circuit 94 and the cylinder chamber 9b, and allows the flow of hydraulic oil from the direction control circuit 94 toward the cylinder chamber 9b. The flow of hydraulic oil toward the direction control circuit 94 is blocked. With this pilot check valve 95, the cylinder chamber 9b can be sealed.
The pilot check valve 95 is opened when pilot pressure is supplied from the direction control circuit 94, and allows the flow of hydraulic oil toward the direction control circuit 94.

FIG. 3 is a functional block diagram of the controller 90.
The controller 90 includes a main control unit 90A, a mold clamping force setting unit 90B, and an input unit 90C. These functions of the controller 90 are constituted by hardware such as a processor and a memory and necessary software.

  The mold clamping force setting unit 90B holds a plurality of set mold clamping forces necessary for the injection operation. The set mold clamping force held in the mold clamping force setting unit 90B will be described later.

  The input unit 90C sequentially samples the mold clamping force generated by the mold clamping cylinder 9 detected by the pressure sensor 80, and holds this.

The main control unit 90A controls the hydraulic circuit 91 (mainly the pressure control valve 93) so that the mold clamping force generated by the mold clamping cylinder 9 becomes the set mold clamping force of the mold clamping force setting unit 90B.
Information such as the clamping force of the clamping cylinder 9 detected by the pressure sensor 80, the injection pressure of the injection cylinder 56, the injection position of the plunger 52, and the like is input to the main control unit 90A, and the hydraulic circuit 91 is based on these information. A control command for (mainly the pressure control valve 93) is generated and output.
Specifically, for example, the main control unit 90A generates a control command so as to compensate for the deviation between the actual mold clamping force detected by the pressure sensor 80 and the set mold clamping force, and the hydraulic circuit 91 (mainly, the pressure To the control valve 93). That is, the main control unit 90A performs feedback control based on the actual mold clamping force detected by the pressure sensor 80.
Since the injection cycle of the die casting machine 1 is very short, it may be difficult to perform feedback control using the mold clamping force detected during the injection cycle. For this reason, it is also possible to control the mold clamping force generated by the mold clamping cylinder 9 using the mold clamping force in the past injection cycle. In this case, for example, an average value of mold clamping forces in a plurality of cycles can be used.

Further, the main control unit 90A determines the current injection operation from the injection position, injection pressure, elapsed time, and the like, and selects a set mold clamping force corresponding thereto.
FIG. 4 is a graph showing an example of the relationship among the injection speed, casting pressure, and set clamping force in the injection operation of the die casting machine 1.
In FIG. 4, (1) shows the injection speed, (2) shows the casting pressure, and (3) shows the set clamping force.

The injection process includes a low speed process, a high speed process, and a pressure increasing process.
As shown in FIG. 4, first, the plunger 52 is driven at the low injection speed VL and then switched to the high injection speed VH. The switching from the low speed injection speed VL to the high speed injection speed VH is, for example, when the plunger 52 reaches a predetermined position. This switching position is a position where the end of the molten metal has substantially reached the gate of the mold.
After driving at a high injection speed VH, the molten metal is filled in the mold cavity, and then the speed control is switched to the pressure control, and the molten metal in the cavity is compressed with a constant force. Thereby, a product is cast.

In the above casting cycle, the set mold clamping force includes a set mold clamping force Fsa corresponding to the low speed injection section, a set mold clamping force Fsb corresponding to the high speed injection section, and a set mold clamping force Fsc corresponding to the pressure increasing section. To do.
Since the molten metal is not injected into the cavity at the low injection speed VL, only a relatively small mold clamping force is required.
In the section of the high injection speed VH, the molten metal is injected into the cavity, and a certain level of mold clamping force is required to prevent the mold from opening.
In the pressure increasing section, the molten metal filled in the cavity is further compressed, so that a larger mold clamping force is required than in the section of the high injection speed VH.

Switching from the setting mold clamping force Fsa to the setting mold clamping force Fsb is, for example, a low injection speed VL.
At high speed injection speed switching position immediately before the switching position of the VH (switching point) P ₁ from. The main control unit 90A determines that the switching position from the low speed to the high speed has been reached based on, for example, the detection signal 98s of the position detector 98, the injection pressure, or the elapsed time from the start of the casting cycle. Can do.
Switching from the setting clamping force Fsb to set clamping force Fsc, for example, immediately before the start of the switching position of about increasing pressure step (switching point) performed by P _2. The main controller 90A determines that the position just before the start of the pressure increasing process has been reached based on, for example, the detection signal 98s of the position detector 98, the injection pressure, or the elapsed time since the start of the casting cycle. be able to.

Next, an example of the operation of the mold clamping device having the above configuration will be described.
The mold clamping apparatus 1 in the state shown in FIGS. 1 and 2 is in a state in which the movable platen 4 has moved to a predetermined mold opening position. In this state, the piston 8 is located on the mold side in the cylinder chamber.

High-speed mold closing From this state, the servo motor 43 is driven to move the movable board 4 in the mold closing direction A2. The moving speed of the moving board 4 is high speed from the viewpoint of shortening the cycle time. When the movable platen 4 is moved in the mold closing direction A2, as shown in FIG. 5, the free end 7b of the tie bar 7 comes into contact with the contact member 30, and the tie bar 7 stops. At this position, the coupled groove 7 a of the tie bar 7 can be coupled to the half nut 20.
From the viewpoint of shock mitigation, it is preferable to reduce the rotational speed of the servo motor 43 immediately before the free end 7b of the tie bar 7 collides with the contact member 30.
In a state where the free end 7 b of the tie bar 7 is in contact with the contact member 30, high pressure hydraulic oil is not supplied to the mold clamping cylinder 9. Therefore, the piston 8 can move in the cylinder chamber of the mold clamping cylinder 9.

As shown in FIG. 5, when the free end 7 b of the tie bar 7 comes into contact with the contact member 30 and the tie bar 7 is positioned, the half nut opening / closing cylinder 21 is driven to close the half nut 20.

In parallel with the operation of closing the low-speed mold closing half nut 20, mold clamping by a relatively low pressure setting mold clamping force Fsa is started.
The moving mechanism 40 continues to move the moving plate 4 in the mold closing direction A2. The movable platen 4 moves to a predetermined mold closing position with respect to the tie bar 7, and the mold closing of the movable mold 6 and the fixed mold 5 is completed as shown in FIG. That is, after the tie bar 7 is positioned, the movable platen 4 moves within the stroke range of the mold clamping cylinder 9 and the mold is closed. The piston 8 moves to the side opposite to the moving mold 6 in the cylinder chamber.
Thereby, during the movement of the moving platen 4, the coupling operation of the half nut 20 and the coupled groove 7a of the tie bar 7 is performed in an overlapping manner.

After completion of the low-pressure mold closing , as shown in FIG. 5, the hydraulic oil PLa from the hydraulic source 92 adjusted to a pressure corresponding to the set mold clamping force Fsa by the pressure control valve 93 passes through the direction control valve 94 to the cylinder chamber. 9b.
By supplying the hydraulic oil PLa to the cylinder chamber 9b, the mold is clamped with the set mold clamping force Fsa.

After the injection operation is started, after a predetermined amount of molten metal is supplied to the sleeve 51, the plunger 52 is driven at a low injection speed VL.

When the pressure reaches the switching position (switching point) P _{1 at} which the mold clamping force is switched immediately before the switching position from the high pressure mold clamping low speed injection speed VL to the high speed injection speed VH, the pressure of the hydraulic oil PLA supplied to the cylinder chamber 9b is increased. The pressure is adjusted by the pressure control valve 93 and the pressure is increased to a pressure corresponding to the set clamping force Fsb.
The piston 8 further moves to the side opposite to the moving mold 6, the tie bar 7 extends, and a mold clamping force corresponding to the extension amount of the tie bar 7 is generated.
As a result, high-pressure clamping is performed. At this time, the hydraulic oil PLa in the cylinder chamber 9b is sealed in a high pressure state.

After the injection and filling mold clamping force is increased to the set mold clamping force Fsb, the molten metal supplied to the sleeve 51 is injected and filled into the cavity.
When the molten metal is injected and filled in the cavity, a mold opening force acts between the molds 5 and 6. At this time, since the cylinder chamber 9b is sealed, the mold clamping cylinder 9 has a very high mold clamping rigidity with respect to this mold opening force. For this reason, even if a surge occurs due to the injection of the molten metal, the mold closed state can be reliably maintained.

Upon reaching the pressure boosting starting immediately before the switching position of the more step up pressure process (switching point) P _2, the pressure of the hydraulic fluid PLa supplied to the cylinder chamber 9b is adjusted by the pressure control valve 93, the set mold clamping force Fsc The pressure is further increased to the corresponding pressure. As a result, a higher clamping force is generated.
When the injection speed control is switched to the pressure increase control, an even greater force acts on the molten metal in the cavity, but the mold clamping force is increased accordingly, so the mold does not open.

Since the cylinder chamber 9b is sealed when the mold clamping pressure release casting is completed, the hydraulic oil PLa in the cylinder chamber 9b is maintained in a high pressure state. If the mold is suddenly opened in this state, an impact is generated. Therefore, as shown in FIG. 6, first, pilot pressure is supplied to the pilot check valve 95 and the pilot check valve 95 is opened. When the pilot check valve 95 is opened, the high-pressure hydraulic oil PLa in the cylinder chamber 9b is released.

High pressure mold opening Subsequently, as shown in FIG. 6, high pressure hydraulic fluid PLb is supplied to the cylinder chamber 9a, the movable platen 4 is moved in the die opening direction A1, clamping is released.
At this time, a releasing force for releasing the mold clamping is applied to the tie bar 7 in the axial direction, and this releasing force is received by the contact member 30.
The piston 8 moves toward the mold in the cylinder chamber.

Half nut release Half nut 20 is released overlapping with the mold clamping release operation. As a result, the connection between the tie bar 7 and the fixed platen 3 is released. The mold clamping release operation and the half nut 20 release operation are performed in duplicate.
Next, the servo motor 43 is driven, and the moving board 4 moves backward to a predetermined position at a low speed. The reason why the moving platen 4 is moved at a low speed is that if the moving platen 4 is moved backward rapidly at a high speed immediately after the mold is opened, there is a possibility that a defect such as damage to a cast product or the die may occur. is there.
When the moving board 4 moves backward to a predetermined position at a low speed, the moving board 4 moves backward at a high speed to the same mold opening position as that shown in FIG.
With the above operation, a series of mold clamping operations is completed.

As described above, according to the present embodiment, the mold clamping force can be accurately controlled by detecting the force generated by the mold clamping cylinder 9 and performing feedback control.
Further, by providing a pilot check valve 95 capable of sealing the cylinder chamber 9b of the clamping cylinder 9 in the hydraulic circuit 91 for driving the clamping cylinder 9, the clamping rigidity of the clamping cylinder 9 can be increased, It is possible to greatly change the clamping force during the cycle.
Further, according to the present embodiment, a necessary mold clamping force is generated according to the injection operation, and therefore the molds 5 and 6 are not clamped with an unnecessarily large mold clamping force. Can be extended.

In the above-described embodiment, the case where the present invention is applied to the composite mold clamping apparatus has been described. However, the present invention can also be applied to a direct pressure mold clamping apparatus that performs mold opening / closing and mold clamping with the same cylinder. .
Moreover, although embodiment mentioned above demonstrated the case where hydraulic fluid was used as hydraulic fluid, it is also possible to use liquids other than oil.

It is a side view which shows the machine structure of the die-casting machine which concerns on one Embodiment of this invention. It is sectional drawing of the horizontal direction of the die-casting machine shown in FIG. It is a functional block diagram of a controller. It is a graph which shows an example of the relationship between the injection speed in the injection | pouring operation | movement of a die-casting machine, casting pressure, and setting clamping force. It is sectional drawing which shows the mold clamping operation | movement in a die-casting machine. It is sectional drawing which shows the mold opening operation | movement in a die-casting machine.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Die casting machine, 2 ... Base, 3 ... Fixed board, 4 ... Moving board, 5 ... Solid mold, 6 ... Moving mold, 50 ... Injection apparatus, 80 ... Pressure sensor, 90 ... Controller, 91 ... Hydraulic circuit, 92 ... Hydraulic source, 93 ... Pressure control valve, 94 ... Direction control valve, 95 ... Pilot check valve, 98 ... Position detector.

Claims (3)

A clamping cylinder that generates a clamping force for clamping a pair of molds;
A hydraulic circuit for supplying hydraulic fluid to the mold clamping cylinder;
Detecting means for detecting the force generated by the clamping cylinder;
A sleeve communicating with a cavity formed in the pair of molds;
A plunger that advances through the sleeve and injects and fills the molten metal into the cavity;
The hydraulic circuit is feedback-controlled so that the mold clamping force detected by the detection means becomes the set mold clamping force, and the plunger is advanced at a low injection speed to inject the molten metal into the cavity in a low speed process. A second clamping force greater than the first clamping force is generated in a high-speed process in which a mold clamping force of 1 is generated and the plunger is advanced at a high-speed injection speed greater than the low-speed injection speed to inject the molten metal into the cavity. A mold clamping force is generated, and a third mold clamping force larger than the second mold clamping force is generated in the pressure increasing step of increasing the pressure of the molten metal filled in the cavity in the low speed process and the high speed process. , the position of the plunger, the injection pressure, or, based on the elapsed time from the start of the casting cycle, the set mold clamping force, before the said first clamping force To the second clamping force, the die casting machine and a control means from the second clamping force switch to the third clamping force. Wherein, the mold clamping force generated in the mold clamping cylinder, according to claim 1 for controlling the hydraulic circuit so as to change stepwise the first to third mold clamping force as a constant Die casting machine. The hydraulic circuit die casting machine according to claim 1 or 2 having pilot check valve the hydraulic fluid for generating the clamping force of the mold clamping cylinder is releasably sealed cylinder chamber supplied.

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