JPH0810930A - Pressure casting device - Google Patents

Abstract

PURPOSE:To provide a pressure casting device which can surely execute a suitable pressurization, by detecting the solidified condition of molten metal independently with the working of a pressurizing means. CONSTITUTION:At the time of starting the casting by using the pressure casting device 2, a hydraulic piston 16 of a hydraulic cylinder 18 for pressurizing is laid on a retreating position to stop the supply of hydraulic pressure into the hydraulic cylinder 18 for pressurizing. At first, an injection plunger is advanced to fill up the molten metal into a cavity 8, and the molten metal temp. near the tip part 20a of a sensor pin is measured with a temp. sensor 22. When this measured temp. reaches the setting temp., the pressurizing oil is supplied into a rear chamber of the hydraulic cylinder 18 for pressurizing, and the pressurizing pin 10 is advanced together with the hydraulic piston 16 to pressurize the molten metal. The pressurization is continued until the pressurizing pin 10 shifts by the preset hydraulic stroke, and the pressurizing oil is supplied to a front chamber of the hydraulic cylinder 18 for pressurizing after passing a fixed time, and the pressurizing pin 10 is retreated to complete the pressurization.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure casting apparatus having means for pressurizing a molten metal filled in a cavity when the molten metal is solidified.

[0002]

2. Description of the Related Art In casting techniques such as die casting,
In order to prevent shrinkage and cavities caused by solidification contraction of the molten metal, pressure casting of the filled molten metal is performed at the stage where the molten metal filled in the cavity solidifies. In order to effectively apply pressure in such pressure casting, it is extremely important to properly set the timing for operating the pressure means such as the pressure pin. Therefore, a method for appropriately setting the timing of pressurization has been developed, and an example thereof is disclosed in Japanese Patent Laid-Open No. 182053/1992. In the technology described in this publication,
After filling the molten metal, with a hydraulic cylinder for driving the pressure pin,
First, the pressurizing pin is advanced slightly. Then, when the repulsive force received by the hydraulic cylinder exceeds a predetermined pressure, it is determined that the molten metal is in a predetermined solidified state, and the pressurizing pin is advanced at high speed to perform pressurization. In this way, the pressurizing timing is determined by the repulsive force received by the pressurizing pin which moves at a slow speed, and the pressurizing casting is performed.

[0003]

However, in such a conventional technique, since the pressurizing pin also serves as a solidification state detecting means, the state inside the molten metal at which the effect of pressurization is actually obtained is directly detected. I can't. That is,
The pressure pin only indirectly detects the solidification state inside the molten metal by the repulsive force received from the outer peripheral portion of the molten metal.
It does not accurately detect the solidification state inside the molten metal. For this reason, it is not possible to reliably set an appropriate pressurizing timing.
Further, since the pressure pin also serves as a solidification state detecting means, the solidification state of the molten metal cannot be known during pressurization (when the pressure pin is moving forward at high speed). For this reason, even if the pressurizing condition (pressurizing force, pressurizing speed, etc.) is not corrected, the pressurizing is performed as it is. Further, there is a problem in that the pressurizing effect is uneven depending on the position of the molten metal due to the pressurizing being performed under such an inappropriate pressurizing timing and pressurizing condition.

Therefore, in the inventions according to claims 1 to 3 of the present application, the solidification state inside the molten metal which is actually pressurized is directly measured separately from the operation of the pressure pin as the pressure means. By doing so, it is an object of the present invention to provide a pressure casting apparatus capable of surely performing appropriate pressure. Further, in the invention according to claim 2, the detection part of the coagulation state detection means is surrounded by the pressurizing pin to prevent a trace of the detection part of the coagulation state detection means from being left, and a cast product having a good shape. It is an object of the present invention to provide a pressure casting device capable of obtaining the above. Further, in the invention according to claim 3, there is provided a pressure casting device capable of uniformly pressurizing the entire molten metal by directly measuring the pressure applied to the molten metal and correcting the pressurizing condition according to the situation. The purpose is to provide.

[0005]

In order to solve the above problems, therefore, in the invention according to claim 1, pressurization for pressurizing the molten metal filled in the cavity at the stage of solidification. In the pressure casting apparatus having means, the pressurizing means has a pressurizing pin whose tip faces the cavity and a driving means for advancing the pressurizing pin in the cavity direction. A coagulation state detecting means for detecting a coagulation state is provided independently of the pressure pin, and protrudes into the cavity from the tip of the pressure pin in a state before the detection portion of the coagulation state detecting means advances. A pressure casting device characterized by being provided was created.

Here, "to face the cavity" means
It means that the tip end surface of the pressure pin projects or faces the cavity. The "driving means" includes a fluid cylinder mechanism such as an air cylinder and a hydraulic cylinder, a hydraulic motor, etc., or an electric driving mechanism such as an electric motor. Further, "solidification state detection means" means means for detecting the solidification state of the molten metal filled in the cavity,
Specifically, it includes a temperature sensor, a pressure sensor, an ultrasonic sensor, and the like. Further, "independently provided" means that the pressurizing means does not serve also as the coagulation state detecting means, and the coagulation state detecting means detects the coagulation state separately from the operation of the pressurizing means. , It does not mean that they are separated as members. Therefore, the case where the coagulation state detecting means is provided in the vicinity of the pressurizing means and the case where the coagulation state detecting means is provided so as to be relatively slidable are included. Further, "protruding into the cavity from the tip of the pressurizing pin" is provided so that the tip of the solidification state detecting means is closer to the inside of the molten metal filled in the cavity than the tip of the pressurizing pin. It means that The method of filling the cavity with the molten metal includes various casting methods such as gravity casting, reduced pressure casting, differential pressure casting, and die casting.

Further, in the invention according to claim 2, in the pressure casting apparatus according to claim 1, the pressure pin is provided so as to surround the detecting portion of the solidification state detecting means. The characteristic pressure casting equipment was created. Here, "surrounding" broadly means that the pressure pin surrounds the detection unit of the coagulation state detection unit, and a plurality of pressure pins surround the detection unit of the coagulation state detection unit. Not only the case but also the case where the pressure pin is one and the detection part of the coagulation state detection means is fitted in the through hole provided in the axial direction thereof.

Further, in the invention according to claim 3,
In the pressure casting apparatus described in claim 2, the pressure casting apparatus is created in which the solidification state detecting means is a pressure sensor. Here, the "pressure sensor" includes various pressure detection devices such as a piezoelectric sensor, a load cell, and a strain sensor.

[0009]

The pressure casting apparatus according to the invention of claim 1 is
It is a pressure casting apparatus that pressurizes the molten metal filled by the pressing means when the molten metal filled in the cavity is solidified. Here, means for detecting the solidification state of the molten metal is provided, and the solidification state detection means is provided independently of the pressurizing means. And
The pressurizing means includes a pressurizing pin whose front end surface faces the cavity, and a driving means for advancing the pressurizing pin toward the cavity. Further, the tip of the coagulation state detecting means projects into the cavity more than the tip of the pressure pin before advancing. Therefore, the solidification state detecting means is closer to the inside of the molten metal that is actually pressurized than the pressurizing pin, and the solidification state inside the molten metal can be directly measured.
Therefore, an appropriate pressurizing timing can be set according to the solidified state inside the molten metal. As described above, by directly measuring the solidification state inside the molten metal that is actually pressed, the pressure casting apparatus can surely set an appropriate pressure timing.

Further, in the pressure casting apparatus according to the second aspect of the invention, the detecting portion of the solidification state detecting means provided so as to project into the cavity has a structure surrounded by a pressure pin. Therefore, it is possible to prevent a trace of the detection portion of the solidification state detecting means from being left on the cast product, and it is possible to obtain a cast product having a good shape. That is, the number of post-processing steps is not increased and the product shape is not restricted. In this way, by surrounding the detection portion of the solidification state detection means with the pressure pin, the pressure casting device can obtain a cast product having a good shape.

The pressure casting apparatus according to the invention of claim 3 is the pressure casting apparatus according to the invention of claim 2, wherein a pressure sensor is used as the solidification state detecting means. Therefore, the pressing force applied to the molten metal can be directly measured by the pressure sensor provided closer to the inside of the molten metal than the pressurizing pin, and the pressurization can be performed while correcting the pressurizing condition according to the situation. As a result, the entire melt can be pressed uniformly. In this way, by directly measuring the pressure applied to the molten metal and correcting the pressurizing condition depending on the situation, the pressure casting apparatus can uniformly press the entire molten metal.

[0012]

【Example】

First Embodiment Next, a first embodiment embodying the present invention will be described with reference to FIGS.
Will be described with reference to. First, the basic configuration of the pressure casting apparatus of this embodiment will be described with reference to FIG. FIG.
FIG. 3 is a cross-sectional view showing the configuration of the main part of the pressure casting device 2 of this embodiment. The main part of the pressure casting apparatus 2 is a mold composed of a movable mold 4, a movable insert 6, a fixed mold (not shown), and a fixed insert, and a product is provided between the movable insert 6 and a fixed insert that faces the movable insert 6. A cavity 8 corresponding to the shape is formed.
A pressure pin 10 is slidably provided in through holes provided in the movable die 4 and the movable insert 6. The pressure pin 10 is slidably attached to a pressure pin bush 12 fixed to the movable insert 6 at its tip portion. Further, the flange portion 10a at the rear end is fixed to the flange portion 16a at the tip of the hydraulic piston 16 by the coupling 14.

The hydraulic piston 16 is slidably fitted in the pressurizing hydraulic cylinder 18, and the hydraulic pressure is supplied to the pressurizing hydraulic cylinder 18 from a hydraulic pressure supply source (not shown). Go forward and backward. Along with this, the pressure pin 10 also moves forward and backward integrally. A space 4a is bored in the movable die 4 to secure a moving space for the coupling 14 when the hydraulic piston 16 moves forward. Inside the pressurizing pin 10, a cylindrical sensor pin 20 having a tip portion 20a narrowed stepwise is slidably attached. Tip portion 20a of the sensor pin 20
When the pressure pin 10 is in the original position (the rear end of the stroke) shown in FIG. The protrusion amount of the sensor pin 20 is set so that the tip end surface of the pressure pin 10 substantially coincides with the tip end portion 20a of the sensor pin 20 when the pressure pin 10 advances to the front end of the stroke.

The flange portion 2 at the rear end of the sensor pin 20
0b is fitted in a through hole provided in the die base 28, and is fixed to the die base 28 by the sensor pin fixing member 26. Therefore, as the hydraulic piston 16 moves forward, the pressure pin 10 is fixed to the fixed sensor pin 2
It will slide forward with respect to 0. The sensor pin 20 can be fixed to the movable base 4 or the outer wall of the pressurizing hydraulic cylinder 18 by using a support block (not shown), instead of fixing it to the die base 28. A bottomed hole is provided in the sensor pin 20 from the flange portion 20b at the rear end to the vicinity of the tip portion 20a, and a temperature sensor 22 is inserted in the bottomed hole. The temperature measuring portion 22a of the temperature sensor 22 is located at the deepest portion of the bottomed hole, that is, near the tip portion 20a of the sensor pin 20. Sensor pin 20
From the flange portion 20b of the signal line 2 of the temperature sensor 22
4 is taken out and connected to an external control unit (not shown).

Next, the overall structure of the pressure casting apparatus 2 will be described with reference to FIG. The hydraulic system of the pressurizing hydraulic cylinder 18 of the pressurizing casting apparatus 2 is configured as shown in FIG. That is, pressure oil is guided from the hydraulic pressure generation source 30 to the rear chamber 18A of the pressurizing hydraulic cylinder 18 through the hydraulic pipe 32A, the electromagnetic directional valve 40, the hydraulic pipe 32B, the electromagnetic opening / closing valve 50, and the hydraulic pipe 32C. On the other hand, a hydraulic pipe 34 is connected to the front chamber 18B of the pressurizing hydraulic cylinder 18, and a hydraulic path returning to the oil tank 38 is formed via the electromagnetic directional valve 40 and the hydraulic pipe 36. Here, the operation of the electromagnetic directional valve 40 is performed by a control signal from a control unit (not shown). Further, the opening / closing of the electromagnetic opening / closing valve 50 is performed by a control signal from a comparator 60 which constitutes a part of a control unit (not shown). The comparator 60 compares the data 62 of the set temperature (T ° C.) stored in the memory device of the control unit with the temperature measured by the temperature sensor 22 input through the signal line 24.
Then, when the measured temperature reaches the set temperature, a control signal for opening the electromagnetic on-off valve 50 is output.

On the other hand, the solenoid on-off valve 50 has two valve chambers 54
A and 54B are provided, and when the electromagnetic solenoid 52 is inactive, the valve chamber 54B in the closed state is connected to the pipe 10C by the repulsive force of the spring 56 (the state shown in FIG. 2). In this case, the pressure oil does not move regardless of the state of the electromagnetic directional valve 40, and the hydraulic piston 16 is kept in a stopped state. On the other hand, when the electromagnetic solenoid 52 operates, the valve chambers 54A and 54B move against the repulsive force of the spring 56, and the valve chamber 54A in the open state is connected to the pipes 32B and 32B.
Connected to C. As a result, the electromagnetic directional valve 40 and the front chamber 18B of the pressurizing hydraulic cylinder 18 are brought into communication with each other, and the hydraulic piston 16 is moved forward and backward or stopped by the operation of the electromagnetic directional valve 40 described below.

The electromagnetic directional valve 40 includes three valve chambers 44A and 44A.
B and 44C, the valve chamber 44C is connected to each pipe by the urging force of the spring 46 when the electromagnetic solenoid 42 is inoperative, and the hydraulic pipes 32A and 34, the hydraulic pipe 3
2B and 36 are connected. Therefore, when the solenoid on-off valve 50 is open, the pressurizing hydraulic cylinder 18
Hydraulic pressure is supplied to the front chamber 18B, the hydraulic piston 16 retracts, and the pressure oil in the rear chamber 18A is transferred to the pipes 32C, 32B,
It is returned to the oil tank 38 via 36. On the other hand, the electromagnetic solenoid 4 is controlled by a control signal from a control unit (not shown).
When 2 is excited, the valve chambers 44A, 44B, 44C move against the biasing force of the spring 46. When the excitation force is controlled to be low, the central valve chamber 44B is connected to each pipe, which is the state shown in FIG. As a result, each of the pipes 32A, 32B, 34, 36 is connected to the closed port, and the pressurizing hydraulic cylinder 18 is disconnected from the hydraulic pressure generation source 30, so that the hydraulic piston 16 stops. When the exciting force is further controlled to be high, the valve chamber 44A
Is connected to each pipe, and the hydraulic pipes 32A and 32B and the hydraulic pipes 34 and 36 are connected. Therefore, hydraulic pressure is supplied to the rear chamber 18A of the pressurizing hydraulic cylinder 18 to move the hydraulic piston 16 forward, and the pressure oil in the front chamber 18B is returned to the oil tank 38 through the pipes 34 and 32A.

Now, a casting process using the pressure casting apparatus 2 having the above structure will be described with reference to FIG. FIG. 3 is a flowchart showing a procedure of pressure casting in the pressure casting apparatus 2 of this embodiment. At the start of pressure casting, the hydraulic piston 16 of the pressurizing hydraulic cylinder 18 is in the retracted position shown in FIG. Further, the electromagnetic directional valve 40 is in a state where the valve chamber 44A is connected to each pipe, and the pressure oil is supplied to the pipe 32B. When the control is started in step S10, an injection plunger (not shown) is moved forward to move the gate of the casting die, runner,
The molten metal is filled in the cavity 8 through the gate (step S12). Then, the temperature sensor 22 measures the temperature of the molten metal near the sensor pin tip portion 20a. Then, the measured temperature is compared with the set temperature (T ° C.) in the comparator 60 of FIG. 2 to determine whether or not the measured temperature has reached the set temperature (step S14). If the determination result is NO, the determination of step S14 is repeated until YES.

When the measured temperature reaches the set temperature T ° C. and the determination in step S14 is YES, the control unit outputs a control signal for opening the electromagnetic on-off valve 50. As a result, the pressure oil is transferred to the rear chamber 18A of the pressurizing hydraulic cylinder 18.
And the pressurizing pin 10 moves forward together with the hydraulic piston 16 to pressurize the molten metal (step S16). The pressurizing pin 10 has the preset pressurizing stroke L1.
It is determined whether or not it has moved (step S18), and pressurization is continued until the determination result is YES. In this embodiment, the pressure stroke L1 is the maximum stroke of the pressure pin 10 (that is, the maximum movement length of the hydraulic piston 16). Therefore, no means for measuring the amount of movement of the pressurizing pin 10 is provided, and the fact that the hydraulic piston 16 has reached the front end and the pressurizing pin 10 has stopped is detected from the flow rate of the pressure oil, and the determination in step S18 is performed. Is going.

After a certain time has elapsed since the determination in step S18 is YES, the electromagnetic directional valve 40 is moved to the valve chamber 44C.
Is switched to a state of being connected to each pipe (step S20). As a result, the pressurizing pin 10 moves backward together with the hydraulic piston 16 and returns to the original position, and the pressurization ends (step S22). After the casting is sufficiently cooled and solidified, the movable die 4 is moved by a drive mechanism (not shown) to open the casting die, and the casting in the cavity 8 is taken out.
One casting process is completed.

As described above, the pressure casting apparatus 2 of this embodiment
In, the tip of the sensor pin 20 for detecting the solidified state of the molten metal is substantially coincident with the stroke tip of the pressurizing pin 10, and the solidified state of the molten metal that is actually pressurized can be directly measured. With this, it is possible to surely perform the pressurization at an appropriate pressurizing timing. Although this embodiment mainly corresponds to the invention of claim 2, the tip of the sensor pin 20 as the coagulation state detecting means coincides with the stroke tip of the pressure pin 10. It is not an essential requirement of the invention. Further, in the present embodiment, the pressurizing hydraulic cylinder 18 and the piston 16 are used as the drive means of the pressurizing pin 10, but other drive means may be used. Further, as the temperature sensor 22, it is possible to use temperature detecting means of various types including a thermocouple.

Second Embodiment Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 4 is a sectional view showing the configuration of the main part of the second embodiment of the pressure casting apparatus according to the present invention. As shown in FIG. 4, the pressure casting device 72 of this embodiment also includes a movable mold 7
4, a movable insert 76, a cavity 78 formed between these and a fixed die (not shown), a fixed insert, a pressure pin 80,
A hydraulic piston 86 for advancing the pressurizing pin 80, a pressurizing hydraulic cylinder 88, a die base 98 and the like are mainly configured. These structures are similar to those of the first embodiment, and detailed description thereof will be omitted. The difference from the first embodiment is that, as shown in FIG. 4, a pressure sensor 92 is provided behind a sensor pin 90 that penetrates the pressure pin 80 in the axial direction. That is, the present embodiment mainly corresponds to the invention of claim 3, and is characterized in that the solidified state and the pressurized state of the molten metal are detected by the pressure.

The external shape of the sensor pin 90 is almost the same as that of the sensor pin 10 of the first embodiment, but there is no sensor insertion hole inside, and the flange portion 90b at the rear end contacts the pressure sensor 92 fixed in the die base 98. There is. by this,
The pressure applied to the tip 90a of the sensor pin 90 in the axial direction is measured by the pressure sensor 92. The signal line 94 of the pressure sensor 92 is taken out to the outside and connected to a control unit (not shown). Further, in the pressure casting apparatus 72 of the present embodiment, unlike the first embodiment, the differential transformer 140 is provided to measure the movement amount of the pressure pin 80. That is, the differential transformer body 140 is attached to the side surface of the pressurizing hydraulic cylinder 88, and the differential transformer body 1 is attached.
The tip of the measuring member 140 a that slides with respect to 40 is attached to the hydraulic piston 86. Accordingly, the moving amount of the hydraulic piston 86, that is, the stroke amount of the pressurizing pin 80 is measured by the differential transformer 140, and the measurement signal is transmitted to the external control unit (not shown) through the signal line 142.

Next, the overall structure of the pressure casting device 72 will be described with reference to FIG. As shown in FIG.
The configuration of the hydraulic system of the pressure casting device 72 is almost the same as that of the first embodiment shown in FIG. The difference from the first embodiment is that the pressure sensor 9
The pressure value measured at 2 is set by the comparator 130, which constitutes a part of a control unit (not shown), as the lower limit pressure P1.
And the set upper limit pressure P2 is compared with two set values. The electromagnetic opening / closing valve 120 is opened / closed by a control signal output from the comparator 130 via the signal line 134.
As a result, in the present embodiment, the pressure applied to the molten metal in the portion measured by the pressure sensor 92 is controlled so as to always be kept within a fixed range. The set pressures P1 and P
2 is stored in the memory device of the control unit. Further, as described above, in the pressure casting device 72, the moving amount of the pressure pin 80 is measured by the differential transformer 140. This measured value is compared with the set stroke value L2 in a comparator 144 that forms part of a control unit (not shown). The operation of the electromagnetic directional valve 110 is controlled by the control signal output from the comparator 144 through the signal line 148.

Now, a casting process using the pressure casting apparatus 72 having the above structure will be described with reference to FIG. FIG. 6 is a flowchart showing the procedure of pressure casting in the pressure casting apparatus 72 of this embodiment. At the start of pressure casting, the hydraulic piston 16 of the pressurizing hydraulic cylinder 18 is in the retracted position shown in FIG. 4, and the electromagnetic directional valve 110 has the valve chamber 114A connected to each pipe. Pressure oil is supplied up to 102B. When the control is started in step S30, the injection plunger (not shown) advances to fill the cavity 78 with the molten metal (step S32), and subsequently, the set time t from the completion of filling.
It is determined whether or not has passed (step S34). The reason for providing the waiting time t is that it takes time for the molten metal to be in a state of solidifying and contracting and pressurizing. After the elapse of the set time t, the pressure received by the pressure sensor 92 via the sensor pin 90 causes the sensor pin tip 90a to move.
The pressure inside the nearby melt is measured. Then, it is determined whether or not the measured pressure is equal to or lower than the set lower limit pressure P1 (step S36). If the determination result is NO, then YE
The determination in step S36 is repeated until S is reached.

When the internal pressure decreases with the solidification contraction of the molten metal and falls below the set lower limit pressure P1, a control signal for opening the electromagnetic on-off valve 120 is output from the control unit, and the pressurizing pin 80 moves forward together with the hydraulic piston 86. Pressurization of the molten metal is performed (step S38). Next, it is determined whether or not the pressurizing pin 80 has moved by the set stroke L2 (step S40). If the result of this determination is NO, then whether or not the measured pressure has reached the set upper limit pressure P2. Is determined (step S42). If the determination result is NO,
The processes of steps S38 to S42 are repeated until YES, and pressurization is continued. Measured pressure is set upper limit pressure P
When the number reaches 2, and the determination in step S42 is YES, a control signal for closing the electromagnetic opening / closing valve 120 is output from the control unit, the pressurizing pin 80 is stopped, and pressurization is interrupted (step S44).

Then, returning to step S36, it is judged whether or not the measured pressure has dropped below the set lower limit pressure P1 due to interruption of pressurization (step S36). If the determination result is NO, the determination of step S36 is repeated until YES. When the measured pressure becomes the set lower limit pressure P1 and the determination in step S36 is YES, the pressurization of the molten metal is restarted (step S38). In this way,
Pressurization is performed stepwise while keeping the measurement pressure within the range of the set lower limit pressures P1 and P2. Then, if the pressurizing pin 80 moves by the set stroke L2 and the determination in step S40 becomes YES, the process proceeds to step S46, and after a certain time has elapsed, the electromagnetic directional valve 110 brings the valve chamber 114C into a state in which it is connected to each pipe. Can be switched. As a result, the pressurizing pin 80 moves backward together with the hydraulic piston 86 to return to the original position, and the pressurization ends (step S48). After the casting is cooled and solidified, it is taken out from the cavity 78,
One casting process is completed.

In the first embodiment described above, the temperature inside the molten metal is measured by the temperature sensor, the solidification state of the molten metal is detected by this, and the pressurization timing is measured. However, since it does not measure the effect of pressurization actually applied inside the molten metal, it is not possible to know whether or not the proper pressurization is being performed. On the other hand, in the pressure casting apparatus 52 of the present embodiment, the pressure inside the molten metal is measured by the pressure sensor, and the pressure is actually applied to the inside of the molten metal during the pressurization by the pressure pin. The pressing force can also be detected. Therefore, it is possible to know whether or not the proper pressurization is actually performed. Also, rather than pressing the entire stroke of the pressurizing pin at once, the pressure is applied stepwise so that the internal pressure of the molten metal is kept within a certain range, so that the entire molten metal is uniformly pressed. There are advantages.

In each of the above embodiments, the case where the temperature sensor or the pressure sensor is used as the coagulation state detecting means has been described, but other detection means such as an ultrasonic sensor may be used as the coagulation state detecting means. . Further, in each of the above-described embodiments, the tip position of the temperature sensor or the pressure sensor is set to coincide with the pressurizing end position of the tip surface of the pressurizing pin, but it does not necessarily have to coincide.
That is, the tip ends of the temperature sensor and the pressure sensor may be projected or retracted from the tip end surface of the pressurizing pin at the end of pressurization. The configurations, shapes, sizes, materials, numbers, connection relationships, etc. of the other parts of the pressure casting apparatus are not limited to those in the above embodiments.

Further, as a peculiar effect in each of the above-mentioned embodiments, since the tip positions of the temperature sensor and the pressure sensor coincide with the tip positions of the pressurizing pins at the time point when the pressurization is completed, the most pressurization is required. The timing of pressurization and the like are determined according to the solidification state of the molten metal at the site. This has the advantage that the highest pressure can be obtained at the site.

[0031]

According to the first aspect of the invention, the coagulation state detecting means for detecting the coagulation state of the molten metal is provided separately from the operation of the pressurizing means. Since it is projected into the cavity more than the tip position of the press pin, the solidified state inside the molten metal that is actually pressed can be directly measured. As a result, the practical pressure casting apparatus can surely set the appropriate pressure timing according to the solidification state inside the molten metal.

Further, in the invention according to claim 2, since the pressure casting apparatus having a structure in which the detection portion of the solidification state detecting means provided so as to project into the cavity is surrounded by the pressure pin, casting is performed. It is possible to prevent traces of the detection portion of the solidification state detection means from remaining on the product. Therefore, the number of post-processing steps is not increased and the product shape is not restricted. In this way, the pressure casting apparatus can obtain a cast product having a good shape without the burden of post-processing and the restriction of the product shape.

Further, in the invention according to claim 3,
Since a pressure casting device using a pressure sensor as a solidification state detection means was created, the pressure applied to the molten metal can be directly measured, and pressure can be applied while modifying the pressure conditions according to the situation. . As a result, an extremely practical pressure casting device capable of uniformly pressing the entire molten metal is obtained.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a configuration of a main part of a pressure casting apparatus according to a first embodiment of the present invention.

FIG. 2 is a diagram showing the overall configuration of a first embodiment of a pressure casting device.

FIG. 3 is a flowchart showing a procedure of pressure casting in Example 1 of the pressure casting apparatus.

FIG. 4 is a cross-sectional view showing a configuration of a main part of a second embodiment of the pressure casting device.

FIG. 5 is a diagram showing an overall configuration of a pressure casting apparatus according to a second embodiment.

FIG. 6 is a flowchart showing a procedure of pressure casting in Example 2 of the pressure casting apparatus.

[Explanation of symbols]

 2,72 Pressure casting apparatus 8,78 Cavity 10,80 Pressurizing means (pressurizing pin) 20,22 Solidification state detecting means (temperature sensor) 90,92 Solidification state detecting means (pressure sensor) 16,18,86, 88 drive means

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Man Inui 1-9-6 Rokujo Minami Gifu City, Gifu Prefecture Gifu Seiki Kogyo Co., Ltd. 1st Division (72) Tsutomu Ezaki 1-9 Rokujo Minami Gifu City Gifu Prefecture -6 Gifu Seiki Industry Co., Ltd. 1st Business Division (72) Inventor Akira Saito 1-9-6 Rokujo Minami, Gifu City, Gifu Prefecture Gifu Seiki Industry Co., Ltd. 1st Business Division

Claims (3)

[Claims] 1. A pressure casting apparatus having pressurizing means for pressurizing the molten metal filled in the cavity when the molten metal is solidified, wherein the pressurizing means has a tip facing the cavity. Solidification state detection means for detecting the solidification state of the molten metal, the solidification state detection means having a pressure pin provided and a drive means for advancing the pressure pin in the cavity direction is provided independently of the pressure pin; The pressure casting apparatus, wherein the detection unit of the state detection unit is provided so as to project into the cavity more than the tip of the pressure pin in a state before advancing. 2. The pressure casting apparatus according to claim 1, wherein the pressure pin is provided so as to surround the detection portion of the solidification state detecting means. 3. The pressure casting apparatus according to claim 2, wherein the solidification state detecting means is a pressure sensor.