JPH06304735A - Die temp. rising method and manufacture of product - Google Patents

Abstract

PURPOSE:To produce a product with effectively raising a die temp. at test production time in the test production having the die temp. lower than the optimum temp. suitable for producing the product. CONSTITUTION:When a die temp. at producing is lower than the optimum temp. suitable to produce a product, the demarketing plane to demarkate a cavity 4A of product shape is moved backward so as to enlarge the cavity volume, A heat medium (molten metal) is filled in the enlarged cavity, raising a temp. of the die 1. After the die temp. reaches the optimum temp. suitable to produce a product and the enlarged cavity is returned to the cavity of a product shape, product material is charged in the cavity of product shape, producing a product.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION In the present invention, when a product is manufactured by casting and injection molding of a resin, when the mold temperature is lower than a temperature suitable for manufacturing the product, the mold temperature is quickly raised. The present invention relates to a product manufacturing method capable of manufacturing a product.

[0002]

2. Description of the Related Art In the casting field, the temperature relationship between molten metal and mold is
In the field of resin injection molding as well, the temperature relationship between the molding resin material and the mold has a great influence on the manufactured product. For example, in die casting, conditions such as the melt temperature, the casting time, and the casting pressure have a great influence on the quality and defective rate of products manufactured by casting. In particular, if the temperature of the mold is too lower than the set appropriate temperature, there is a possibility that dimensional defects of the product (casting), defective running of the molten metal, etc. may occur. Therefore, in order to make the mold (mold) temperature appropriate to prevent production (casting) defects, the mold temperature is generally raised by the heat of the molten metal from the test manufacturing, which causes the product temperature to rise. After reaching the temperature suitable for manufacturing, product manufacturing is performed.

Specifically, Japanese Patent Application Laid-Open No. 2-59164 discloses a method of raising the mold temperature by the heat of molten metal. Here, a dummy cavity is formed in a place other than the product-shaped cavity of the mold, and the communication part between this dummy cavity and the product-shaped cavity is made openable and closable, so that the die temperature can be controlled during die casting. Accordingly, the communication portions of the dummy cavities are opened / closed to change the volumes of all the cavities, and the amount of the molten metal to be filled is increased / decreased in accordance with the volume changes of all the cavities. As a result, not only the product-shaped cavities but also the dummy cavities are filled with the molten metal to raise the temperature of the cooled mold. Then, after the mold temperature reaches a temperature suitable for manufacturing a product, the product is manufactured.

[0004]

However, when the production of the product is repeated after the test production is completed and the heat quantity of the molten metal is transferred to the die and the die temperature rises too much, it is necessary to cool the die. However, when installing the cooling pipe for circulating the cooling medium in the mold, since the dummy cavity is provided around the product-shaped cavity, the installation space of the cooling pipe is regulated by the dummy cavity. box office. For this reason, there is a problem that it is not possible to expect the improvement of the cooling efficiency of the mold at the time of manufacturing the product. The present invention has been made in view of such circumstances, and increases the mold temperature by increasing the amount of heat transferred from the inside of the product-shaped cavity to the defining surface that defines the product-shaped cavity. The purpose is to improve the cooling efficiency of the mold at the time of product manufacturing by securing the installation space of the cooling pipes instead of the dummy cavities.

[0005]

[PROBLEMS] To solve the above problem, there is provided a manufacturing method for promptly increasing the mold temperature to manufacture a product when the mold temperature is lower than a temperature suitable for manufacturing the product. Of the cavities defining the cavities to increase the volume of the cavities, to fill the enlarged cavities with a heat medium for test production, and to define the cavities. Advancing a surface and returning from the enlarged cavity to the product shaped cavity. (Hereinafter, referred to as the first invention.) A manufacturing method for rapidly increasing the mold temperature to enable product manufacturing when the mold temperature is lower than the temperature suitable for manufacturing the product. Of the cavities defining the cavities to increase the volume of the cavities, to fill the enlarged cavities with a heat medium for test production, and to define the cavities. The step of advancing the surface, returning from the enlarged cavity to the cavity of the product shape, and then introducing the product raw material into the cavity to manufacture the product. (Hereinafter, referred to as the second invention.)

[0006]

The operation of the first and second inventions will be described.
When the mold temperature is lower than an appropriate temperature suitable for manufacturing the product, the cavity surface is expanded by retracting the defining surface defining the cavity of the product shape. After that, when the enlarged cavity is filled with the heat medium and the test manufacturing is performed, the cavity is formed through the defining surface that defines the cavity of the product shape more than when the cavity of the product shape before the enlargement is filled with the heat medium. The amount of heat transferred from the inside of the mold to the entire mold can be increased, and the rise of the mold temperature can be promoted. By filling the expanded cavity with a heating medium and repeating the test production, the mold temperature can be raised to an appropriate temperature suitable for producing a product. After the mold temperature reaches an appropriate temperature suitable for manufacturing the product, the defining surface defining the expanded cavity is advanced to move from the expanded cavity to the product-shaped cavity, and then to the cavity. Product raw materials are input to manufacture products.

[0007]

【Example】

(First Embodiment) FIGS. 1, 2 and 3 are schematic views of a die casting mold used in the first embodiment of the present invention.
First, FIG. 1 shows a schematic horizontal cross-sectional view at the time of manufacturing the product of the mold used in the first embodiment. The mold 1 is a fixed mold 2, a movable mold 3, a nest 5, and a nest support block slide device 15.
It is composed of A and 15B and a nest slide device 20. Nesting support block slide device 15A, 1
5B is a cylinder 8, an oil chamber 10, an oil chamber 12, a hydraulic pressure supply / discharge port 11, a hydraulic pressure supply / discharge port 13, a piston 9A, a piston 9B,
It is composed of a rod 7 and a nesting support block 6. In addition, the nesting slide device 20 includes a cylinder 21,
Oil chamber 24, oil chamber 26, hydraulic pressure supply / discharge port 25, hydraulic pressure supply / discharge port 2
7, piston 22, and rod 23.

In the mold 1, a cavity 4A having a product shape is formed by the movable mold 3 and the nest 5 in a state where the fixed mold 2 and the movable mold 3 are combined, and a molten metal (product raw material) is produced by an injection device (not shown) of a die casting machine. ) Is filled into the product-shaped cavity 4A through a runner (not shown) to manufacture a die-cast product.

A telescopic slide device 20 is attached to the fixed mold 2. When hydraulic pressure is supplied to the oil chamber 24 of the cylinder 21 from the hydraulic pressure supply / discharge port 25 by a hydraulic circuit (not shown), the piston 22 moves in the forward direction ( A force acting in the left direction of the drawing acts and the insert 5 connected to the rod 23 moves forward (moves in the left direction of the drawing) using a guide portion (not shown) of the fixed mold 2 as a guide. The movement of the rod 7 and the nest support block 6 connected to the pistons 9A and 9B toward the inside of the mold is called forward, and the movement toward the outside of the mold is called backward. When hydraulic pressure is supplied from the hydraulic pressure supply / discharge port 27 to the oil chamber 26 of the cylinder 21 while the nest support block 6 is retracted, a backward direction (force in the right direction in the drawing) acts on the piston 22 to retract the nest 5.

Further, the fixed die 2 is provided with telescopic support block slide devices 15A and 15B, and when hydraulic pressure is supplied to the oil chamber 10 of the cylinder 8 from the hydraulic pressure supply / discharge port 11, the piston 9A moves downward in the drawing. A force acts on the piston 9B in the direction of the top of the drawing, and the nest support block 6 connected to the rod 7 uses the nest support block sliding portion 14 of the fixed mold 2 as a guide to move the pistons 9A and 9B in the forward direction ( Move to the inside of the mold). Similarly, when hydraulic pressure is supplied from the hydraulic pressure supply / discharge port 13 to the oil chamber 12 of the cylinder 8, the pistons 9A and 9B move in the backward direction (outward direction of the mold).

The forward limit of the nest support block 6 is that the tip of the nest support block 6 is a stopper portion 2a of the fixed mold 2.
Is regulated by hitting. Nesting support block 6
The hydraulic pressure is applied to the side for retracting the insert 5 in a state where the position is set, that is, the hydraulic pressure of the oil chamber 26 is made larger than that of the oil chamber 24 and the hydraulic pressure is moved backward so that the insert 5 for the fixed mold 2 is moved.
Is positioned to ensure the dimension of the product shape cavity 4A in the thickness direction.

FIG. 2 is a schematic horizontal sectional view of the mold used in the first embodiment at the time of test manufacturing. Here, the pistons 9A and 9B are retracted, and the nest 5 is also retracted. The retracting limit of the insert 5 is regulated by the flange portion 23a of the rod 23 hitting the stopper portion 2b of the fixed mold 2.

In order to ensure that the rear surface of the insert 5 is supported by the insert support block 6, the insert 5 is in the state shown in FIG.
Is advanced to overstroke, the tip of the nest support block 6 is surely abutted against the stopper portion 2a, the nest 5 is retracted, and the rear surface of the nest 5 is brought into contact with the side surface of the nest support block 6. is there. Further, in the state of FIG. 2, in order to surely support the rear surface of the nest 5 by the nest support block 6, the nest support block 6 is retracted with an overstroke, and the nest 5 is retracted to securely secure the flange portion 23a of the rod 23. A method of advancing the nest support block 6 after abutting the stopper portion 2b to bring the side surface of the nest support block 6 into contact with the rear surface of the nest 5 is advantageous. In this case, it is necessary to suppress the thrust of the nest support block slide devices 15A and 15B.

FIG. 3 is a schematic vertical sectional view of the mold used in the first embodiment at the time of test manufacturing. The molten metal (heat medium) in the sprue bush 16 is filled into the enlarged cavity 4B via the runner 17 by an injection device (not shown) of a die casting machine.

When manufacturing is performed using the above apparatus, the nest support block 6 is retracted when the mold temperature is lower than the proper temperature suitable for manufacturing the product and the test manufacturing is required. After that, the cavity 5 is expanded by retracting the nest 5 to retract the defining surface 5e that defines the product-shaped cavity 4A. After the expanded cavity 4B is formed, the expanded cavity 4B is filled with molten metal as a heat medium. As a result, the product-shaped cavity 4A
By filling the expanded cavity 4B with a larger volume of molten metal than the volume at the time, the amount of heat transferred from the expanded cavity 4B to the partition surface defining the cavity 4B is also increased by the increased amount of molten metal. By increasing the amount, the temperature of the mold near the partition surface defining the product-shaped cavity 4A can be increased more than when the volume of the product-shaped cavity 4A is filled with the molten metal.

The switching from test production to product production is determined by whether or not the temperature of the mold, particularly the temperature of the surface of the cavity 4A of the product shape, has reached an appropriate temperature suitable for producing the product.

After the mold temperature reaches an appropriate temperature suitable for manufacturing the product and the test manufacturing is completed, the nest 5 is advanced, and then the nest support block 6 is advanced to define the cavity 4B. The cavity is returned to the product-shaped cavity 4A by advancing the growth surface 5e, and the molten metal (product raw material) is filled (input) into the product-shaped cavity 4A to manufacture the product.

To move the insert 5 and the insert support block 6 forward and backward, and to increase and decrease the amount of hot water supplied, the number of test products required for the mold temperature to reach the reference temperature is experimentally obtained in advance and a predetermined number of test products are produced. Even if the worker switches to product manufacturing at the time of completion of the process, the worker can determine whether the temperature is below the appropriate temperature or above the appropriate temperature suitable for producing the product by providing a mold temperature measuring means. After that, a method of switching to product manufacturing may be used. Also, if the die temperature is measured with the start of the die casting machine, the die temperature and the appropriate temperature are compared, and it is automatically judged and displayed whether to continue test production or switch to product production. Not only can an operator easily make a judgment, but also an operator can switch to product manufacturing when a predetermined test manufacturing is completed, which enables more accurate and reliable judgment and wasteful test manufacturing. In addition to the disappearance, it is possible to prevent the generation of defective products due to the products that are produced below the proper temperature being manufactured. Furthermore, by automatically judging whether the mold temperature is below the appropriate temperature or above the appropriate temperature, and automatically switching between test manufacturing and product manufacturing, it is possible to avoid wasteful test manufacturing. Needless to say, it is possible to prevent defective products from being produced as products that are produced at a temperature below the appropriate temperature.

The product manufacturing mentioned here is not limited to die casting manufacturing (casting), but the present manufacturing method can be applied to a mold for manufacturing a resin product by injection molding.

(Second Embodiment) FIGS. 4 and 5 are schematic views of a die casting mold used in a second embodiment of the present invention. FIG. 4 shows a schematic horizontal sectional view (partially omitted) of the mold used in the second embodiment during manufacturing, and FIG. 5 shows a horizontal cross section of the mold used in the second embodiment during test manufacturing. A schematic diagram (partially omitted) is shown. Here, the alternate long and short dash line shown in FIG. 4 and FIG. 5 shows the line symmetry axis in the horizontal cross-sectional schematic view (overall view) of the mold used in the second embodiment, and FIG. 4 and FIG. On the other hand, it shows only the structure on one side. Of course, the mold structure and the operating mechanism on the omitted side are the same as those described with reference to FIGS. 4 and 5.

The difference from the first embodiment is the structure for restricting the forward movement limit of the insert 5. The insert 5 is advanced by the insert slide device 20, and the stopper 5a of the insert 5 is projected to the stepped portion 2c of the fixed mold 2. The structure is configured to move the nesting support block 6 forward by the nesting support block slide device 15A in the contacted state until it stops.

In the first embodiment, when the nest supporting block 6 and the rear surface of the nest 5 are worn due to the repeated sliding of the nest supporting block 6 due to the structure and a gap is generated, a cavity having a product shape is formed. It is conceivable that due to the pressure of the molten metal when the molten metal flows in, the insert 5 is displaced in the backward direction by the amount of the gap caused by the abrasion, and the dimensional accuracy of the product is disturbed. However, in the structure of the second embodiment, the stopper portion 5a of the insert 5 abuts on the stepped portion 2c of the fixed mold 2, and further, before the insert support block 6 abuts on the advance limit, the insert 5 is inserted. Since the stopper portion 5a hits the stepped portion 2c of the fixed mold 2, the advancement of the insert 5 is stopped. As a result, as compared with the first embodiment, even if the clearance is generated between the nest support block 6 and the rear surface of the nest 5, the nest support block 6 is advanced until it reaches the advance limit. The force to be applied becomes a force to press the rear surface of the nest 5, and the stopper portion 5a of the nest 5 is the stepped portion 2c of the fixed mold 2.
It will be the force to work as if you hit. This force opposes the force with which the molten metal presses the insert 5 in the retracting direction of the insert 5 when the molten metal flows into the cavity of the product shape, thereby suppressing the displacement of the insert 5 due to the pressing force of the molten metal. This is a structure in which the dimensional accuracy of is further improved as compared with the first embodiment. Further, the structure for restricting the retracting limit of the nest 5 is similar to that of the first embodiment.

(Third Embodiment) FIGS. 6 and 7 are schematic views of a die casting mold used in a third embodiment of the present invention. FIG. 6 shows a schematic horizontal cross-sectional view (partially omitted) of the mold used in the third embodiment during manufacturing, and FIG. 7 shows a horizontal cross-section of the mold used in the third embodiment during test manufacturing. A schematic diagram (partially omitted) is shown. Here, the alternate long and short dash line shown in FIGS. 6 and 7 indicates the line symmetry axis in the horizontal sectional schematic view (overall view) of the mold used in the third embodiment, and FIGS. 6 and 7 indicate the line symmetry axis. On the other hand, it shows only the structure on one side. Of course, the mold structure and the operating mechanism on the omitted side are the same as those described with reference to FIGS. 6 and 7.

The difference from the first and second embodiments is that the nest support block 6 is provided with a stopper portion 6b.
The point is that a stepped portion 5c is provided on the tapered portion on the rear surface of the insert 5. In this device, when retracting the nest 5, the nest support block slide device 15A causes the nest support block 6 to retreat in an overstroke manner, and then the nest slide device 20 causes the rear surface of the nest 5 to contact the side surface of the nest support block 6, The nesting support block 6 is advanced by the nesting support block slide device 15A until the stopper portion 6b hits the end surface 5d.

When the insert 5 is advanced, the insert slide device 20 advances the insert 5 with a short stroke, and then the insert support block slides until the stopper portion 6b of the insert support block 6 abuts on the stepped portion 5c of the insert 5. Nesting support block 6 by device 15A
Is moved forward, and then the nest 5 is returned to the retracted side by the nest slide device 20, and the size of the cavity 4A in the product shape is determined. According to this device, the nest 5 for the fixed mold 2
The positioning processing portions of are only provided on the rear surface of the insert 5 and on the side surface of the insert support block 6 at one place each.
It is not necessary to provide a processing portion (position 2b in the fixed die 2 in the first and second embodiments) for positioning when forming the expanded cavity 4B of the insert 5.

(Fourth Embodiment) FIGS. 8 and 9 are schematic views of a die casting mold used in a fourth embodiment of the present invention. FIG. 8 is a horizontal cross-sectional schematic view (partially omitted) of the mold used in the fourth embodiment during manufacturing, and FIG. 9 is a horizontal cross-section of the mold used in the fourth embodiment during test manufacturing. A schematic diagram (partially omitted) is shown. Here, the alternate long and short dash line shown in FIG. 8 and FIG. 9 indicates the line symmetry axis in the horizontal sectional schematic view (overall view) of the mold used in the fourth embodiment, and FIG. 8 and FIG. On the other hand, it shows only the structure on one side. Of course, the mold structure and the operating mechanism on the omitted side are the same as those described with reference to FIGS. 8 and 9.

The difference from the first to third embodiments is that the forward limit and the backward limit of the insert 5 are restricted by the meshing of the tooth profile 5b of the insert 5 and the tooth profile 6a of the nest support block 6. The reaction force received by the insert 5 from the molten metal at the time of manufacture is received by the meshing of the tooth profile 5b of the insert 5 and the tooth profile 6a of the nest support block 6.

In the case of this device, when the insert 5 is moved forward and backward, the tooth support 6a is moved backward by the insert support block slide device 15A to move the insert 5 forward by one pitch.
Move the nest support block 6 forward and move the nest support block 6 forward.
The tooth profile portion 5b of the above and the tooth profile portion 6a of the nest support block 6 are engaged with each other.

When the rod 23 connected to the insert 5 receives the reaction force of the molten metal at the time of manufacturing, when the reaction force of the molten metal does not evenly move the insert 5 in the vertical direction in the drawing at the time of pouring the molten metal, the rod 23 is attached to the rod 23. A varying stress is applied and the rod 23 is damaged. However, according to this apparatus, since the reaction force of the molten metal is received by the side surface of the insert 5 when pouring the molten metal, it is necessary to increase the rigidity of the insert 5. However, since the reaction force of the molten metal is not transmitted to the rod 23, the rod 23 It is possible to reduce the risk of causing problems.

[0030]

According to the present invention, the volume of the cavity is expanded by retracting the defining surface that defines the cavity of the product shape at the time of test manufacturing, and the volume of the cavity of the product shape is expanded and then expanded. The amount of heat transferred from the inside of the expanded cavity to the defining surface that defines the cavity of the product shape can also be increased by filling the formed cavity with the heat medium (molten metal). As a result, as compared with the case where the volume of the product-shaped cavity is filled with the heat medium (molten metal), it is possible to accelerate the rise of the mold temperature in the vicinity of the defining surface that defines the product-shaped cavity. As a result, it is not necessary to arrange a heat medium oil pipe for heating the mold or a dummy cavity in the mold near the cavity of the product shape, so that a space for arranging the mold cooling pipe can be secured. Furthermore, the mold cooling pipe (not shown) can be installed in the optimum arrangement around the cavity of the product shape, so that the mold cooling efficiency can be improved and the manufacturing cycle time when manufacturing the product can be shortened. As a result, it will lead to improved productivity and lower product cost.

[Brief description of drawings]

FIG. 1 is a schematic horizontal cross-sectional view of a mold used in the first embodiment of the present invention when manufacturing a product.

FIG. 2 is a schematic horizontal cross-sectional view at the time of test manufacturing of the mold used in the first embodiment of the present invention.

FIG. 3 is a schematic vertical cross-sectional view of the mold used in the first embodiment of the present invention during test manufacturing.

FIG. 4 is a horizontal cross-sectional schematic view (partially omitted) at the time of manufacturing a product of the mold used in the second embodiment of the present invention.

FIG. 5 is a horizontal cross-sectional schematic view (partially omitted) during test manufacturing of the mold used in the second embodiment of the present invention.

FIG. 6 is a horizontal cross-sectional schematic view (partially omitted) at the time of manufacturing the product of the mold used in the third embodiment of the present invention.

FIG. 7 is a horizontal cross-sectional schematic view (partially omitted) at the time of manufacturing a test product of the mold used in the third embodiment of the present invention.

FIG. 8 is a horizontal cross-sectional schematic view (partially omitted) at the time of manufacturing the product of the mold used in the fourth embodiment of the present invention.

FIG. 9 is a horizontal cross-sectional schematic view (partially omitted) at the time of test manufacturing of the mold used in the fourth example of the present invention.

[Explanation of symbols]

 1 ... Mold (mold) 4A ... Cavity (product shape cavity) 4B ... Cavity (enlarged cavity) 5e ... Definition surface defining a product shape cavity

Claims (2)

[Claims] 1. A method of manufacturing, wherein when a mold temperature is lower than a temperature suitable for manufacturing a product, the mold temperature can be rapidly raised to manufacture a product, and a cavity having a product shape is defined. A step of retracting the defining surface forming the cavity to expand the volume of the cavity, a step of filling the expanded cavity with a heat medium for test production, and advancing the defining surface defining the cavity. And a step of returning the expanded cavity to the cavity of the product shape. 2. A method of manufacturing, wherein when a mold temperature is lower than a temperature suitable for manufacturing a product, the mold temperature can be rapidly raised to manufacture a product, and a cavity having a product shape is formed. A step of retracting the defining surface forming the cavity to expand the volume of the cavity, a step of filling the expanded cavity with a heat medium for test production, and advancing the defining surface defining the cavity. And a step of returning the expanded cavity to the cavity having the product shape and then introducing a product raw material into the cavity to manufacture the product.