JP2002210550A - Locally pressurized casting system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a locally pressurized casting system by which a cast product having high quality excellent in mechanical characteristic can easily and surely be obtained. SOLUTION: An accelerating means 14 for accelerating a response speed and a moving speed of a cylinder 2B for locally pressurizing, is arranged and a timing T21 for starting the local pressurization with the cylinder 2B for locally pressurizing, is synchronized with a timing T20 for starting the pressure intensification with a cylinder 2A for main pressurization.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a local pressure casting system, and more particularly to a local pressure casting system capable of easily and reliably obtaining a high-quality casting having excellent mechanical properties.

[0002]

2. Description of the Related Art Conventionally, as one method of manufacturing a casting as a casting, a molten metal such as a die cast is injected at a high pressure and injected into a mold, and the molten metal injected into the mold is increased in pressure and injected into the mold. Local pressure casting is known in which the molten metal injected into a mold is locally pressurized when the pressure of the molten metal is increased.

FIG. 3 shows a main part of a general local pressure casting system used in a conventional local pressure casting. The conventional local pressure casting system 1 includes a first local pressure casting system as a main pressing cylinder. It has a hydraulic cylinder 2A and a second hydraulic cylinder 2B as a local pressurizing cylinder.

The first hydraulic cylinder 2A is for injecting molten metal and injecting the molten metal into the mold M, and for increasing the pressure of the molten metal injected into the mold M.
A has a first hydraulic circuit 3A as a drive source.
The hydraulic pump 4A is connected. Then, by driving the first hydraulic pump 4A, the oil L as the working fluid stored in the oil tank 5A can be supplied to the first hydraulic cylinder 2A. Also, the first hydraulic circuit 3
A and the first hydraulic pump 4A are operation-controlled based on a control command (control signal) sent from the control unit 6 that controls the system, and control the operation of the plunger rod 2Aa of the first hydraulic cylinder 2A, The control of the hydraulic pressure of the oil L supplied to the first hydraulic cylinder 2A is performed at a predetermined timing.

The second hydraulic cylinder 2B is for locally pressurizing the molten metal injected into the mold M. The second hydraulic cylinder 2B has a second hydraulic circuit 3B as a drive source via a second hydraulic circuit 3B. The second hydraulic pump 4B is connected.
By driving the second hydraulic pump 4B, the oil tank 5B
Can be supplied to the second hydraulic cylinder 2B as the working fluid stored in the second hydraulic cylinder 2B. The operation of the second hydraulic circuit 3B and the second hydraulic pump 4B is controlled based on a control command sent from a control unit 6 that controls the system, and the operation of the plunger rod 2Ba of the second hydraulic cylinder 2B is controlled. And the control of the oil pressure of the oil L supplied to the second hydraulic cylinder 2B can be performed at a predetermined timing.

[0006] The mold M comprises at least a fixed mold MA,
It has a movable MB and a movable MC for local pressurization.
As shown in FIG. 3, a movable type MB and a local pressurizing type movable type MC are arranged at a predetermined interval with respect to the fixed type MA.

According to the local pressure casting system 1 formed as described above, the molten metal LM is injected at a high pressure and injected into the mold M, and the molten metal LM injected into the mold M is increased in pressure.
Further, when increasing the pressure of the molten metal LM injected into the mold M, the molten metal LM injected into the mold M is locally pressurized.

The operation of the conventional local pressure casting system 1 will be described. As shown in FIG. 4, the molten metal LM is injected with the movable mold MB abutting the fixed mold MA. The injection of the molten metal LM is performed by controlling the hydraulic pressure of the oil L supplied to the first hydraulic cylinder 2A, thereby controlling the moving speed that is the operation speed of the plunger rod 2Aa of the first hydraulic cylinder 2A. Then, by moving the plunger rod 2Aa of the first hydraulic cylinder 2A at a predetermined speed, the molten metal LM in the chamber (casting cylinder) 7 of, for example, a heat insulating furnace also serving as a melting furnace is injected from the nozzle 8 at a predetermined pressure. To the cavity C of the mold M.

Further, the molten metal LM is placed in the cavity C of the mold M.
After filling (filling), the hydraulic pressure of the oil L supplied to the first hydraulic cylinder 2 </ b> A is controlled to be higher, so that
By moving the plunger rod 2Aa of the hydraulic cylinder 2A at high speed, the pressure of the molten metal LM injected into the cavity C of the mold M is increased.

When the pressure of the molten metal LM injected into the cavity C of the mold M is increased, the hydraulic pressure of the oil L supplied to the second hydraulic cylinder 2B is controlled to a high pressure, so that the plunger rod 2Ba of the second hydraulic cylinder 2B is controlled. Is moved at high speed to move the movable type MC for local pressurization toward the fixed type MA at high speed, thereby locally pressing the molten metal LM injected into the cavity C of the mold M. FIG. 5 shows a state where the pressure increase and the local pressurization are completed.

FIG. 6 shows the relationship between the pressure applied by each of the hydraulic cylinders 2A and 2B and the drive timing. FIG.
, T00 denotes the injection start timing (driving start timing of the first hydraulic cylinder 2A), and T10 denotes the moving speed of the plunger rod 2Aa during injection for injecting the molten metal LM into the cavity C of the mold M as described later. Start timing of high-speed injection performed at high speed, symbol T20
Is the timing of the start of the pressure increase, T21 is the timing of the start of the local pressurization (drive start timing of the second hydraulic cylinder 2B), T30 is the timing of the completion of the pressure increase, and T31.
Indicates the timing of completion of the local pressurization.

As described above, in the conventional local pressure casting system 1, by controlling the hydraulic pressure supplied to the first hydraulic cylinder 2A to a low pressure by the first hydraulic circuit 3A, the molten metal LM is injected into the mold M. The operating speed (moving speed) of the plunger rod 2Aa at the time is relatively low,
By controlling the hydraulic pressure supplied to the hydraulic cylinder 2A to be higher by the first hydraulic circuit 3A, the operating speed of the plunger rod 2Aa at the time of increasing the pressure of the molten metal LM injected into the mold M is increased. I have.

The operating speed, which is the moving speed of the plunger rod 2Aa at the time of injection for injecting the molten metal LM into the cavity C of the mold M, is divided into two stages, a low speed and a high speed, as shown by a broken line in FIG. Controlling the pressure in two stages of low-speed injection and high-speed injection by increasing the pressure stepwise generally means that the injection time of the molten metal LM into the mold M can be shortened and the number of shots per time can be increased. For example, in the case of die casting using an aluminum alloy as a material, the moving speed of the plunger rod 2Aa at low speed is about 0.2 m / sec, and the moving speed of the plunger rod at high speed is about 1 to 2 m / sec. Controlling. Furthermore, the time required for pressure boosting, specifically, the time from the start to the completion of pressure boosting, varies depending on the type of material used for casting and the product wall thickness, for example, when forming a cast product using an aluminum alloy as a material. Is 0.04 to 0.1
It is generally set to about sec.

A drive timing for driving the second hydraulic cylinder 2B as a local pressurizing cylinder,
The transmission timing of the control signal for driving the second hydraulic cylinder 2B is determined by the first hydraulic cylinder 2 serving as the main pressurizing cylinder.
This is performed by detecting the pressure at the time of increasing the pressure of A, using a timer for controlling the time, or the like.

As the main pressurizing cylinder and the local pressurizing cylinder, there is also a configuration in which air, water or the like is used as a working fluid.

[0016]

However, in the above-mentioned conventional local pressure casting system 1, both the first hydraulic cylinder 2A as the main pressure cylinder and the second hydraulic cylinder 2B as the local pressure cylinder are hydraulically driven. Because of the drive, as shown in FIG. 6, there is a problem that the start timing T21 of the local pressurization is delayed from the start timing T20 of the pressure increase (a time lag occurs).

That is, the conventional local pressure casting system 1
Has a problem that the timing T21 of the start of the local pressurization cannot be synchronized with the timing T20 of the start of the pressure increase.

More specifically, in the conventional local pressure casting system 1, the control signal of the drive timing of the second hydraulic cylinder 2B, which is the timing T21 of the start of the local pressurization, is used to increase the pressure of the first hydraulic cylinder 2A. This is performed by detecting an increase in pressure at the time or by using a timer or the like. However, in the case of detecting the increase in pressure of the first hydraulic cylinder 2A using a pressure sensor or the like, the first hydraulic cylinder Since the increase in the hydraulic pressure after the start of the pressure increase by 2A is detected, the timing T21 of the start of the local pressurization is detected.
Is delayed from the pressure increase start timing T20. When a timer is used, it is extremely difficult to adjust the time required for local pressurization by a timer or the like for 0.04 to 0.1 sec.

Further, in the conventional local pressure casting system 1, the time required for increasing the pressure is 0.04 to 0.1 sec.
The operating speed of the plunger rod 2Ba of the second hydraulic cylinder 2B as the local pressurizing cylinder needs to be extremely high. However, the current drive source of the second hydraulic cylinder 2B is the second hydraulic pump 4B. Since the pumping amount of such a hydraulic pump is small, the hydraulic pressure supplied to the second hydraulic cylinder 2B is increased to a predetermined pressure. It takes time until the hydraulic pressure supplied to the second hydraulic cylinder 2B reaches a predetermined pressure after receiving the control command. That is, the second
Since the response speed of the hydraulic cylinder 2B is low, the control unit 6
Is configured to drive the second hydraulic cylinder 2B using a control command to start the pressure increasing operation by the first hydraulic cylinder 2A sent from the controller, that is, to start each of the pressure increasing operation and the local pressurizing operation. Even if the transmission timings of the instructing control commands are simultaneously set, as shown in FIG. 6, the start timing T21 of the local pressurization is changed to the start timing T21 of the pressure increase.
It will be late from 20.

As shown by the broken line in FIG. 6, the timing T21 of the start of the local pressurization can be synchronized with the timing T20 of the start of the pressure increase by the first hydraulic cylinder 2A by a timer or the like. In some cases,
It cannot be avoided that the timing T31 of the completion of the local pressurization is delayed from the completion timing T30 of the pressure increase.

As described above, when the timing T21 of the start of the local pressurization is delayed from the timing T20 of the start of the pressure increase, segregation, coarse structure, shrinkage cavities, and the like are liable to occur in the cast product after solidification. Which are inferior to the mechanical characteristics easily occur.

In particular, the end of the sprue where the thick part is large (distant)
In the case of forming a casting that exists through a thin wall portion, the molten metal LM that has touched the surface of the cavity C of the mold M is solidified first, so that the timing T21 of the start of local pressurization
Is delayed from the timing T20 of the start of the pressure increase, the solidified portion is locally pressurized in the thick portion, and the pressure due to the local pressurization is applied to the unsolidified molten metal LM located at the center of the thick portion. Do not communicate effectively. As a result, the thick part located at the end does not undergo directional solidification, segregation, a coarsened structure, shrinkage cavities, and the like are more likely to occur in the thick part, and the mechanical properties of the cast product are further deteriorated. Further, in severe cases, cracks may be formed along the pressing direction on the surface of the boundary portion of the local pressurization of the casting.

A similar problem occurs when air, water, or the like is used as a working fluid for driving the main pressurizing cylinder and the local pressurizing cylinder.

Therefore, there is a need for a local pressure casting system capable of easily and reliably obtaining a high quality cast product having excellent mechanical properties.

The present invention has been made in view of the above points, and an object of the present invention is to provide a local pressure casting system capable of easily and reliably obtaining a high-quality casting having excellent mechanical properties. I do.

[0026]

In order to achieve the above-mentioned object, the feature of the local pressure casting system of the present invention according to claim 1 is that the response speed and the operation speed of the local pressure cylinder are increased. This is characterized in that a high-speed means for increasing the pressure is provided so that the timing of the start of the local pressurization by the local pressurizing cylinder is synchronized with the timing of the start of the pressure increase by the main pressurizing cylinder. By adopting such a configuration, the response speed of the local pressurizing cylinder can be increased, so that the timing of the start of the local pressurization by the local pressurizing cylinder is started by the main pressurizing cylinder. Can be synchronized.
Therefore, it is possible to easily and reliably obtain a high-quality cast product having excellent mechanical properties.

The local pressure casting system of the present invention according to claim 2 is characterized in that, in claim 1, the accumulator is capable of holding the working fluid supplied to the local pressure cylinder by the speed-up means in a pressurized state. At one point. And by adopting such a configuration, the accumulator
Since the working fluid used for driving the local pressurizing cylinder can be held in a pressurized state in advance, a high-pressure working fluid can be supplied to the local pressurizing cylinder in a short time. Therefore, it is possible to more reliably increase the response speed and the operating speed of the local pressurizing cylinder.

According to a third aspect of the present invention, there is provided a local pressure casting system according to the first or second aspect of the present invention, wherein the control signal for instructing the start of the local pressurization of the local pressurization cylinder is used for the main pressurization. This is a control signal for instructing the start of cylinder pressure increase. By adopting such a configuration, the start timing of the local pressurization by the local pressurization cylinder can be easily and reliably synchronized with the start timing of the pressure increase by the main pressurization cylinder with a simple configuration. .

According to a fourth aspect of the present invention, there is provided a local pressure casting system according to any one of the first to third aspects, wherein the timing of completion of the local pressing by the local pressing cylinder is mainly determined. The point is that it is formed so as to be synchronized with the timing of completion of pressure increase by the pressurizing cylinder. By adopting such a configuration, the timing of the completion of the local pressurization by the local pressurizing cylinder can be easily and reliably synchronized with the timing of the completion of the pressure increase by the main pressurizing cylinder. It is possible to easily and reliably obtain a high-quality casting with excellent mechanical properties.

According to a fifth aspect of the present invention, there is provided a local pressure casting system according to the present invention, wherein the control signal for instructing the completion of the local pressurization of the local pressurization cylinder is a pressure increase of the main pressurization cylinder. Is a control signal instructing the completion of. By adopting such a configuration, it is possible to easily and reliably synchronize the timing of the local pressurization by the local pressurization cylinder with the timing of the completion of the pressure increase by the main pressurization cylinder with a simple configuration. .

[0031]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments shown in the drawings. Note that the same or corresponding components as those of the above-described conventional device are denoted by the same reference numerals, and detailed description thereof will be omitted.

FIG. 1 is a configuration diagram showing a configuration of a main part of an embodiment of a local pressure casting system according to the present invention in a state before injection.

The local pressure casting system of the present embodiment is configured to hydraulically drive the main pressure cylinder and the local pressure cylinder.

As shown in FIG. 1, the local pressure casting system 11 of the present embodiment has a first hydraulic cylinder 2A as a main pressure cylinder and a second hydraulic cylinder 2B as a local pressure cylinder. ing.

The first hydraulic cylinder 2A is for injecting and injecting the molten metal LM into the mold M and increasing the pressure of the molten metal LM injected into the mold M.
The first hydraulic cylinder 2A is connected to a first hydraulic pump 4A as a drive source via a first hydraulic circuit 3A. Then, by driving the first hydraulic pump 4A, the oil L as the working fluid stored in the oil tank 5A can be supplied to the first hydraulic cylinder 2A. The first hydraulic circuit 3A and the first hydraulic pump 4A
Is controlled based on a control command sent from the control unit 12 that controls the system, and controls the operation of the plunger rod 2Aa of the first hydraulic cylinder 2A,
The control of the hydraulic pressure of the oil L supplied to the first hydraulic cylinder 2A is performed at a predetermined timing.

The second hydraulic cylinder 2B is for locally pressurizing the molten metal poured into the mold M. The second hydraulic cylinder 2B is connected to the second hydraulic cylinder 2B via a second hydraulic circuit 13 as a drive source. The second hydraulic pump 4B is connected.
The second hydraulic circuit 13 is provided with an accumulator 14 as a speed-up means. By driving the second hydraulic pump 4B, the oil L as the working fluid stored in the oil tank 5B is supplied to the accumulator 14. A pressurized state can be maintained so as to maintain a preset hydraulic pressure inside. When the oil L is supplied to the second hydraulic cylinder 2 </ b> B, the oil L having a predetermined oil pressure stored in the accumulator 14 can be supplied.
The second hydraulic circuit 13 and the second hydraulic pump 4B
The operation of the plunger rod 2Ba of the second hydraulic cylinder 2B is controlled by the operation control based on a control command sent from the control unit 6 that controls the system, and the predetermined hydraulic oil L is supplied to the second hydraulic cylinder 2B. The supply timing is controlled at a predetermined timing.

The control unit 12 includes at least a CPU,
And a memory (both not shown) formed of a ROM, a RAM, or the like having an appropriate capacity. And, in the memory, a fixing plate for fixing at least the fixed mold MA of the mold M,
A control program for controlling the operation sequence and operation timing of each part of the system including the operation sequence of the movable plate for fixing the movable mold MB of the mold M is stored. The control program includes a control signal for controlling the operation of the first hydraulic cylinder 2A, and further includes a control signal for starting and completing the local pressurization by the second hydraulic cylinder 2B using the control signal for controlling the operation of the first hydraulic cylinder 2A. It can be sent.

That is, the control signal instructing the start of the pressure increase by the first hydraulic cylinder 2A is applied to the start of the local pressurization by the second hydraulic cylinder 2A, more specifically, the predetermined hydraulic oil L stored in the accumulator 14 2 hydraulic cylinder 2B
The control signal instructing the completion of the pressure increase by the first hydraulic cylinder 2A is also used as the control signal to start the supply to the second hydraulic cylinder 2A, more specifically, a predetermined control signal stored in the accumulator 14. Hydraulic oil L
It can also be used as a control signal for stopping supply to the hydraulic cylinder 2B. In other words, the control signal instructing the start and completion of the pressure increase of the second hydraulic cylinder 2B is a control signal instructing the start and completion of the pressure increase of the first hydraulic cylinder 2A.

As will be described later, since the response speed and the operation speed of the second hydraulic cylinder 2B can be increased, for example, the first hydraulic cylinder 2A can be operated without using a control signal for controlling the operation of the first hydraulic cylinder 2A. The configuration may be such that the pressure of the cylinder 2A is detected and the respective timings of starting and completing the local pressurization by the second hydraulic cylinder 2B are controlled. However, in this case, components such as a pressure sensor for detecting the pressure of the first hydraulic cylinder 2A are required, which complicates the configuration and increases the economic burden.

The other components of the local pressure casting system 11 are configured in the same manner as in the prior art, and thus detailed description thereof will be omitted.

Next, the operation of the present embodiment having the above-described configuration will be described.

FIG. 2 is a diagram showing the relationship between pressure and drive timing in the embodiment of the local pressure casting system according to the present invention.

According to the local pressure casting system 11 of the present embodiment, the driving of the second hydraulic cylinder 2B as the local pressure cylinder is performed by using a predetermined hydraulic oil L stored in the accumulator 14. This accumulator 14
Since oil L as a working fluid used for driving the second hydraulic cylinder 2B can be held in a pressurized state in advance,
The oil pressure L set in advance can be supplied to the second hydraulic cylinder 2B in a short time. That is, in the present embodiment, since the oil holding the hydraulic pressure set in advance by the accumulator 14 can be supplied to the second hydraulic cylinder 2B, the response speed and the operating speed of the second hydraulic cylinder 2B are increased. Can be.

Further, according to the local pressure casting system 11 of the present embodiment, when the control signal for instructing the first hydraulic cylinder 2A to start increasing the pressure is transmitted, the start of the increase of the pressure by the first hydraulic cylinder 2A is performed. And the start of the local pressurization by the second hydraulic cylinder 2A, more specifically, the start of the supply of the oil L of the predetermined hydraulic pressure stored inside the accumulator 14 to the second hydraulic cylinder 2B. At this time, since the response speed of the second hydraulic cylinder 2B is high, the timing T21 of the start of the local pressurization and the timing T20 of the start of the pressure increase are synchronized as shown in FIG.

When a control signal for instructing the completion of the pressure increase by the first hydraulic cylinder 2A is transmitted, the completion of the pressure increase by the first hydraulic cylinder 2A and the completion of the local pressurization by the second hydraulic cylinder 2A are described in detail. The supply of the oil L having a predetermined oil pressure stored in the accumulator 14 to the second hydraulic cylinder 2B can be stopped. At this time,
Since the operating speed of the second hydraulic cylinder 2B is high, the timing T31 of the completion of the local pressurization can be reliably and easily synchronized with the timing T30 of the completion of the pressure increase, as shown in FIG.

In this embodiment, the timings T21 and T31 for starting and completing the local pressurization are synchronized with the timings T20 and T30 for starting and completing the pressure increase. The completion timing T31 does not necessarily have to be synchronized with the pressure increase completion timing T30. That is, even if the timing T31 of the completion of the local pressurization is before or after the timing T30 of the completion of the pressure increase, there is no practical adverse effect on the cast product. However, if the timing T31 of the completion of the local pressurization is later than the timing T30 of the completion of the pressure increase, depending on the shape and dimensions of the casting, there may be a bad influence on the casting such as cracks.
It is preferable to synchronize the timing T31 of the completion of the local pressurization with the timing T30 of the completion of the pressure increase in the sense that a high-quality cast product having more excellent mechanical properties can be obtained.

Further, even when the pressure at the time of completion of the local pressurization by the second hydraulic cylinder 2B is higher or lower than the pressure at the time of completion of the pressure increase by the first hydraulic cylinder 2B, there is no practical problem given to the casting.

Furthermore, the state before injection, the injection completed state, the pressure increase, and the local pressure completed state of the molten metal LM in the local pressure casting system 11 of the present embodiment are the same as those in the prior art. Detailed description is omitted.

Therefore, according to the local pressure casting system 11 of the present embodiment, the local pressurization start timing T21 is delayed from the conventional pressure pressurization start timing T20, and the local pressurization is started. Since it is possible to reliably prevent the mechanical properties of the cast product from being lowered due to inconveniences such as the occurrence of pressure-induced solidification, segregation, coarse structure, and shrinkage cavities, which occur in the thick portion where pressure is applied, A high-quality casting with excellent mechanical properties can be obtained easily and reliably.

According to the accumulator 14 of the local pressure casting system 11 of the present embodiment, the working fluid oil L used for driving the second hydraulic cylinder 2B as the local pressure cylinder is held in a pressurized state in advance. Since the high-pressure oil L can be supplied to the second hydraulic cylinder 2B in a short time, the response speed and the operating speed of the second hydraulic cylinder 2B can be more reliably increased.

Further, according to the local pressure casting system 11 of the present embodiment, the control signal instructing the start and the completion of the local pressurization of the second hydraulic cylinder 2B is transmitted to the start and the end of the pressure increase of the first hydraulic cylinder 2A. Since the control signal is a control signal instructing completion, the start and completion timings T21 and T31 of the local pressurization by the second hydraulic cylinder 2B are changed to a start and completion timing T20 of the pressure increase by the first hydraulic cylinder 2A with a simple configuration. , T30, it is possible to synchronize easily and reliably.

Further, according to the local pressure casting system 11 of this embodiment, the timing T31 of the completion of the local pressure.
Is synchronized with the pressure increase completion timing T30.
A high-quality cast product having more excellent mechanical properties can be obtained easily and reliably.

The present invention is not limited to the above embodiment, but can be variously modified as needed. For example, a configuration may be adopted in which at least the local pressurizing cylinder is driven by pneumatic driving other than hydraulic pressure, hydraulic driving, or the like.

[0054]

As described above, according to the local pressure casting system according to the first aspect of the present invention, since the response speed of the local pressure cylinder can be increased, the local pressurization by the local pressure cylinder can be improved. The timing of starting the pressure can be synchronized with the timing of starting the pressure increase by the main pressurizing cylinder. Therefore, it is possible to easily and reliably obtain a high-quality cast product having excellent mechanical properties.

According to the second aspect of the present invention, the working fluid used for driving the local pressurizing cylinder can be held in a pressurized state in advance. A high-pressure working fluid can be supplied in a short time. Therefore, an extremely excellent effect is obtained such that the response speed and the operation speed of the local pressurizing cylinder can be more reliably increased.

According to the third aspect of the present invention, the start and completion timings of the local pressurization by the local pressurization cylinder are started by the main pressurization cylinder with a simple configuration. This makes it possible to easily and surely synchronize with the timing described above.

According to the local pressure casting system of the present invention, the completion timing of the local pressurization by the local pressurization cylinder can be easily and reliably adjusted to the timing of the completion of the pressure increase by the main pressurization cylinder. Therefore, it is possible to obtain an extremely excellent effect such that a high-quality cast product having more excellent mechanical properties can be easily and reliably obtained.

According to the local pressure casting system of the present invention, the completion timing of the local pressurization by the local pressurization cylinder is simplified by the simple configuration. Thus, an extremely excellent effect such as easy and reliable synchronization can be achieved.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a configuration of a main part of an embodiment of a local pressure casting system according to the present invention in a state before injection.

FIG. 2 is a diagram showing a relationship between pressure and drive timing in the local pressure casting system shown in FIG.

FIG. 3 is a configuration diagram showing a configuration of a main part of a conventional local pressure casting system in a state before injection.

FIG. 4 is a view similar to FIG. 3, showing a configuration of a main part of the conventional local pressure casting system in an injection completed state following FIG. 3;

FIG. 5 is a view similar to FIG. 3, showing a configuration of a main part of the conventional local pressure casting system in a state where pressure is increased and local pressure is completed following FIG. 4;

FIG. 6 is a diagram showing the relationship between pressure and drive timing in a conventional local pressure casting system.

[Explanation of symbols]

 2A 1st hydraulic cylinder (as a main pressure cylinder) 2B 2nd hydraulic cylinder 3A (as a local pressure cylinder), 1st hydraulic circuit 4A 1st hydraulic pump 4B 2nd hydraulic pump 5A, 5B Oil tank 7 chamber 8 nozzle 11 Local pressure casting system 12 Control unit 13 Second hydraulic circuit 14 Accumulator M Mold L Oil (as working fluid) T00 Timing of starting injection T20 Timing of starting pressure boosting T21 Timing of starting local pressure boosting T30 Pressure boosting Completion timing T31 Completion timing of local pressurization

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hidenobu Harano 1012 Wada-cho, Kameyama-shi, Mie Pref.Yanagikawa Seiki Co., Ltd. Inside the plant (72) Inventor Shoichi Higa 1012 Wada-cho, Kameyama-shi, Mie Pref.Yanagikawa Seiki Co., Ltd.

Claims (5)

[Claims] 1. A main pressurizing cylinder for injecting a molten metal and injecting the molten metal into a mold and increasing the pressure of the molten metal poured into the mold, and a local pressurizing cylinder for locally pressurizing the molten metal poured into the mold. A local pressure casting system comprising: a speed increasing means for increasing a response speed and an operation speed of the local pressure cylinder; and a timing of starting local pressure by the local pressure cylinder by the main pressure cylinder. A local pressure casting system formed so as to be synchronized with the start timing of pressure increase. 2. The local casting system according to claim 1, wherein said high-speed means is an accumulator capable of holding a working fluid supplied to said local pressurizing cylinder in a pressurized state. 3. The control signal for instructing start of local pressurization of the local pressurizing cylinder is a control signal for instructing start of pressure increase of the main pressurizing cylinder. 3. The multiple pressure casting system according to 2. 4. The apparatus according to claim 1, wherein timing of completion of local pressurization by said local pressurizing cylinder is synchronized with timing of completion of pressure increase by said main pressurizing cylinder. The local pressure casting system according to any one of claims 1 to 4. 5. The control signal according to claim 4, wherein the control signal instructing completion of local pressurization of the local pressurizing cylinder is a control signal instructing completion of pressure increase in the main pressurizing cylinder. Local pressure casting system.