JP2015178114A - Core pin structure for die casting - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress occurrence of loosening of a screw due to pitch difference of a plurality of screws without adding new components.SOLUTION: A core pin structure for die casting includes: a fixed mold 2 and a movable mold 4 for creating a cavity space of a product shape; and a core pin 6 assembled by being fastened by a screw from a surface of the cavity 5 formed at the fixed mold 2. In the core pin structure for die casting, at a fitting tip-most part of a pin assembling recess 21 formed at the fixed mold 2, a first female screw part 22 is provided. At a screw fastening shaft 61 of the core pin 6, a first male screw part 62 and a second male screw part 63 having different pitches are provided. The first male screw part 62 provided at the fitting tip-most part of the screw fastening shaft 61 is screwed and fitted with respect to the first female screw part 22. The second male screw part 63 is embedded and fixed with respect to a solidified aluminum alloy 41 which is solidified in a clearance space 31 secured between the screw fastening shaft 61 and the pin assembling recess 21.

Description

  The present invention relates to a die-cast core pin structure called a front pin that is assembled by tightening with a screw from the surface of a cavity formed in a mold.

  2. Description of the Related Art Conventionally, as a die casting core pin structure called a front pin, one using two screws having different pitch directions is known (see, for example, Patent Document 1).

JP 2010-214383 A

  However, in the conventional die-casting pin structure for die casting, one of the two screws is screwed between the casting pin and the mold, and the other screw is between the casting pin and the bush. It is configured to be screwed in between. For this reason, when assembling the core pin to the die, a new part called a bush is added, which increases the number of parts, deteriorates assembling and disassembling, and limits the use site. It was.

  The present invention has been made by paying attention to the above-described problem, and provides a die-cast core pin structure capable of suppressing the occurrence of screw loosening due to a pitch difference between a plurality of screws without newly adding parts. For the purpose.

In order to achieve the above object, a die casting die pin structure of the present invention includes a die that creates a product-shaped cavity space, and a die that is assembled by tightening with a screw from the surface of the cavity formed in the die. And a pin.
In this die-cast core pin structure, a first female thread portion is provided at the forefront fitting portion of the pin assembly recess formed in the die. A plurality of male screw portions having different pitches were provided on the screw fastening shaft of the core pin.
The first male screw portion provided at the most fitting portion of the screw tightening shaft was screwed and fitted into the first female screw portion. A solid aluminum alloy solidified in a clearance space secured between the screw tightening shaft and the pin assembly recess is embedded and fixed with another male screw portion having a pitch different from the pitch of the first male screw portion. did.

Therefore, among the plurality of male screw portions having different pitches provided on the screw tightening shaft of the core pin, the first male screw portion is screwed into the first female screw portion of the mold. The other male screw portion having a pitch different from the pitch of the first male screw portion is embedded and fixed to the solidified aluminum alloy solidified in the clearance space secured between the screw tightening shaft and the pin assembly recess.
That is, paying attention to the molten aluminum alloy used as the material of the die-cast product, other male screw portions having different pitches are embedded and fixed in the solidified aluminum alloy. The cast pin is embedded and fixed in a state in which the cast pin is screwed to the aluminum alloy solidified after the molten aluminum alloy enters the screw groove. For this reason, the movement of the axial direction with respect to the metal mold | die of a core pin is suppressed. In addition, even if the core pin is about to rotate in the loosening direction due to an input such as vibration, screws having different pitches serve as stoppers that restrict the rotation of each other. Therefore, the core pin is assembled to the mold with a plurality of screws having different pitches without adding parts such as bushes, and the occurrence of loosening of the screw is suppressed even if vibration or the like is applied during mass production of the product.
In addition, since the cast pin is a front pin that is assembled by tightening with a screw from the surface of the cavity formed in the mold, the mold structure is simplified compared to the back pin that is inserted from the back side of the mold. Reduction of mold production cost.
As a result, it is possible to suppress the occurrence of screw loosening due to the pitch difference between a plurality of screws without adding new parts, and it is possible to reduce the die manufacturing cost by simplifying the die structure. .

It is a mold-clamping process explanatory drawing which shows the mold-clamping process of the aluminum die-casting method using the fixed metal mold | die with the die-casting pin structure for die-casting of Example 1. FIG. It is a molten metal filling process explanatory drawing which shows the molten metal filling process of the aluminum die-casting method using the fixed metal mold | die with the die-casting pin structure for die-casting of Example 1. FIG. It is a product release process explanatory drawing which shows the product release process of the aluminum die-casting method using the fixed metal mold | die with the die-casting pin structure for die-casting of Example 1. FIG. FIG. 3 is a die configuration diagram showing a configuration of a die pin assembly recess in the die casting core pin structure of the first embodiment. It is a core pin block diagram which shows the structure of the core pin among the core pin structures for die-casting of Example 1. FIG. It is sectional drawing which shows the core pin structure for die-casting of Example 1. FIG. FIG. 5B is a cross-sectional view taken along the line B-B in FIG. 5 showing the configuration of the core pin in the core pin structure for die casting according to the first embodiment. It is explanatory drawing which shows the "front pin" and the "back pin" which classified the die casting core pin by the assembly | attachment method. It is operation | work explanatory drawing which shows the pin removal operation | work from the metal mold | die at the time of replacing | exchanging the cast pin in the cast pin structure for die-casting of Example 1. FIG. It is sectional drawing which shows the die-casting pin structure for die-casting by another Example.

  Hereinafter, the best mode for realizing the die-casting pin structure for die casting of the present invention will be described based on Example 1 shown in the drawings.

First, the configuration will be described.
The structure of the die-casting pin structure for die casting in Example 1 is “Aluminum die-casting method”, “Detailed structure of the casting pin structure”, “Background technology of the casting pin”, “Operation of assembling the casting pin to the fixed die” ”And“ Other characteristic effects of die-cast core pin structure ”will be described separately.

[Aluminum die casting method]
First, based on FIGS. 1-3, the aluminum die-casting method using the fixed metal mold | die with a die-casting pin structure for die-casting of Example 1 applied to manufacture of the transmission case of a transmission is demonstrated.

  A schematic configuration of a die casting machine used in the aluminum die casting method will be described. As shown in FIGS. 1 to 3, the die casting machine is fixed to the fixed mold 2 (mold) fixed to the fixed mold base 1 and the movable mold base 3. And a movable mold 4 (mold) provided so as to be reciprocally movable in a direction perpendicular thereto.

  The fixed mold base 1 and the fixed mold 2 include a cavity 5, a casting pin 6, a casting cylinder 7, a molten metal injection hole 8, a casting piston 9, a casting port 10 (biscuits), and a runner. 11 (runner) and a gate 12 (gate). The cavity 5 refers to a carved surface (space) corresponding to a product portion of the fixed mold 2. The cast pin 6 (= core pin) is provided in the fixed mold 2 and protrudes from the cavity 5 of the fixed mold 2 to the product side, and a pilot hole before tapping is formed in advance at the screw hole processing position of the product. It is a member for placing. The casting cylinder 7 is provided on the fixed mold base 1 and the fixed mold 2.

  The movable mold base 3 and the movable mold 4 include a cavity 5 ′ formed by a protruding surface corresponding to a product portion of the movable mold 4, an extrusion plate 13 and an extrusion pin 14 that extrude the product when releasing the solidified product. Have. In FIG. 1 to FIG. 3, the illustration of a hot water pool (overflow) for drawing in the previous run of molten metal, etc., and an air vent engraved on the mold surface in order to remove the gas in the mold cavity is omitted. Yes.

  The aluminum die casting method includes a mold clamping step (FIG. 1), a molten metal filling step (FIG. 2), and a product release step (FIG. 3) as a manufacturing process of the die-cast as-cast product A.

  The mold clamping step is a step of clamping the two fixed molds 2 and the movable mold 4 so as to create a product-shaped cavity space as shown in FIG. That is, a release agent is applied to the cavities 5 and 5 ′, and the movable mold 4 is moved toward the fixed mold 2 in the direction of arrow F in FIG. 1 from the solid line position in FIG.

  As shown in FIG. 2, the molten metal filling step is a step of press-fitting and filling a molten aluminum alloy into the cavity space. That is, by pouring a molten aluminum alloy from the molten metal injection hole 8 of the casting cylinder 7 and pushing it by the casting piston 9, the molten metal under pressure is filled in the cavity space through the casting port 10 → the runner 11 → the pouring gate 12. To do. Using this molten metal filling process, the core pin 6 is embedded and fixed to the solidified solid aluminum alloy 41.

  In the product release step, as shown in FIG. 3, the molten metal at 650 ° C. to 700 ° C. is cooled to about 200 ° C., and after waiting for the molten aluminum alloy to solidify, the fixed mold 2 and the movable mold 4 This is a step of taking out the die-cast as-cast product A. That is, by casting the casting piston 9 and the extrusion pin 14, the die-cast product A is released from the cavity space of the fixed mold 2 and the movable mold 4.

[Detailed structure of cast pin structure]
4-7 shows the die-casting pin structure for die-casting of Example 1. FIG. Hereinafter, based on FIGS. 4-7, the detailed structure of a cast pin structure is demonstrated.

  The die casting core pin structure includes a fixed die 2 (FIG. 4) that creates a product-shaped cavity space, and a core pin that is assembled by tightening with screws from the surface of the cavity 5 formed in the fixed die 2. 6 (FIG. 5), and no additional parts are used.

  As shown in FIG. 4, the fixed mold 2 is provided with a pin assembly recess 21, a first female screw portion 22, and a second female screw portion 23. The pin assembly recess 21 includes a first female screw hole 21a, a second female screw hole 21b, and an inlet hole 21c from the back side of the fixed mold 2, and the inner diameter of the hole is such that the inlet hole 21c> second female hole. A stepped recess is formed by the relationship of screw hole 21b> first female screw hole 21a. The first female screw portion 22 and the second female screw portion 23 are female screws having different pitches. The first female screw portion 22 is provided on the inner surface of the first female screw hole 21a, and the second female screw portion 23 is provided. It is provided on the inner surface of the second female screw hole 21b.

  As shown in FIG. 5, the core pin 6 is provided with a screw tightening shaft 61, a first male screw portion 62, a second male screw portion 63, and a pin shaft portion 64. The screw tightening shaft 61 includes a first male screw shaft portion 61a, a second male screw shaft portion 61b, a positioning shaft portion 61c, and a tapered shaft portion 61d from the shaft end side. The maximum shaft diameter is set to be slightly smaller than the inner diameter of the inlet hole 21 c of the fixed mold 2. The first male screw portion 62 and the second male screw portion 63 are male screws having different pitches. The first male screw portion 62 is provided on the outer surface of the first male screw shaft portion 61a, and the second male screw portion 63 is provided. Is provided on the outer surface of the second male screw shaft 61b. The pin shaft portion 64 has a shape corresponding to a pilot hole of a screw hole (conical shape with a top surface cut), and is provided so as to protrude integrally from the tapered shaft portion 61 d of the screw tightening shaft 61. As shown in FIG. 7, a hexagonal hollow hole 65 is formed at the axial center position of the core pin 6. As shown in FIG. 7, a molten metal intrusion cut surface 61e is formed on the upper surface of the positioning shaft portion 61c, and a molten metal intrusion passage is secured.

  When the first male screw portion 62 of the screw tightening shaft 61 is screwed and assembled to the first female screw portion 22 of the pin assembling concave portion 21, the pin mounting concave portion 21 and the screw tightening shaft 61 are not A clearance space 31 is formed. As shown in FIG. 4, the clearance space 31 includes a second male screw embedded space 31a, a molten metal introduction space 31b, a reverse tapered communication space 31c, and an annular gap 31d.

  A first female screw portion 22 is provided at the most fitting front end portion of the pin assembly concave portion 21 formed in the fixed mold 2. A first male screw portion 62 and a second male screw portion 63 having different pitches are provided on the screw tightening shaft 61 of the core pin 6. Then, as shown in FIG. 6, the first male screw portion 62 provided at the foremost fitting portion of the screw tightening shaft 61 is screwed into the first female screw portion 22. With respect to the solidified aluminum alloy 41 solidified in the clearance space 31 secured between the screw tightening shaft 61 and the pin assembly recess 21, the second male screw portion 63 having a pitch different from the pitch of the first male screw portion 62. And fix it. The pin assembly recess 21 is provided with a second female screw portion 23 at a position facing the second male screw portion 63.

  As shown in FIG. 4, the clearance space 31 includes an annular gap 31d through which molten aluminum alloy can enter, and a second male screw in a region that communicates with the annular gap 31d and covers the entire outer periphery of the second male screw portion 63. Embedded space 31a (male thread embedded space). Here, as shown in FIG. 6, the annular gap 31 d allows the molten aluminum alloy to enter the clearance space 31, but once the molten metal has entered the clearance space 31 flows out toward the cavity 5. It is set to a gap size (for example, 0.2 mm) that suppresses this. A reverse taper communication space 31c is provided at a position connecting the annular gap 31d and the second male screw embedding space 31a in a direction opposite to the product draft from the fixed mold 2. As shown in FIG. 6, the tip of the reverse tapered communication space 31 c is an annular gap 31 d provided at a position corresponding to the cavity 5 of the fixed mold 2. Note that an arrow D in FIG. 6 is an intrusion path of the molten aluminum alloy.

  As shown in FIG. 7, a hexagonal hollow hole 65 (polygonal hole) opened from the fitting front end portion side is provided in the central shaft portion of the core pin 6. The hexagonal hollow hole 65 is provided at a depth up to a midpoint of the pin shaft portion 64 that protrudes from the cavity 5 of the fixed mold 2 in a state where the core pin 6 is assembled to the fixed mold 2 (FIG. 5). reference).

[Background technology of cast pin]
In general, the tap (screw) hole of a die-cast product adopts “casting” as the range of the pilot hole drill in order to prevent a cast hole and improve tapping workability.
For the “casting”, a main mold of a mold and a “casting pin” having a separate structure are used. The reason why the “cast pin” having a separate structure is adopted is that the shape of the cast is thin and long and often breaks, so that the shape can be easily restored.

As shown in FIG. 8, the method of assembling the “cast pin” to the main mold is as follows:
(a) Method of tightening with screws from the surface of the main mold (common name: front pin)
(b) Inserting from the back of the main mold (common name: back pin)
There are two types.
With the “front pin”, the manufacturing cost of the core pin and the processing cost of the main mold are low, and the die cost is low. However, it cannot be used in mass production due to “screw loosening”.
The “back pin” has a large (long) cast pin and a high manufacturing cost. Further, since the processing range of the main mold is widened, the processing cost is increased and the mold cost is increased. Furthermore, a long-time machine (production) stoppage is generated in the replacement of the core pin during mass production.

However, since the “front pin” has a problem that cannot be used in mass production (screw loosening) as described above, a “back pin” is often adopted in a die casting machine for manufacturing a mass-produced product.
In other words, when trying to adopt a “table pin” that is advantageous in terms of cost, etc. to a die casting machine that manufactures mass-produced products,
-It can be assembled from the mold (main mold) surface.
-Screws should not loosen during mass production. (The punching depth will be deep.)
-There should be no casting burrs at the mating part. (No product burr finish)
-It must be replaceable from the mold (main mold) surface when it is worn or broken.
It is necessary to satisfy the above requirements.

[Assembly action of cast pin to fixed mold]
The assembling action of the core pin 6 to the fixed die 2 by the die casting core pin structure of Example 1 which is a “surface pin” assembled from the surface of the die (main die) will be described.

  The cast pin 6 is inserted into the pin assembly recess 21 from the cavity 5 side, which is the surface of the fixed mold 2, and the first male screw portion 62 is screwed into the first female screw portion 22. The assembling work of the core pin 6 is completed only by this screwing work.

  In the melt filling process in the break-in operation called “discarding”, when filling the melt into the cavity space, at the same time, the melt is put into the clearance space 31 secured between the core pin 6 and the pin assembly recess 21. Invade. Then, the second male screw portion 63 of the core pin 6 is embedded and fixed to the solidified solid aluminum alloy 41 by the molten metal entering the clearance space 31. Here, “discarding” refers to the habituation that is performed by the die casting method of the same procedure as that for making a regular product to raise the mold temperature to about 200 ° C. before entering the mass production system of the die cast as-cast product A. It is a driving | operation and is normally performed about 5 to 10 times.

  As described above, in the first embodiment, among the first male screw portion 62 and the second male screw portion 63 having different pitches provided on the screw tightening shaft 61 of the core pin 6, the first male screw portion 62 is It is screwed into the first female screw portion 22 of the fixed mold 2. The second male screw portion 63 is configured to be embedded and fixed to the solidified aluminum alloy 41 solidified in the clearance space 31 secured between the screw tightening shaft 61 and the pin assembly recess 21.

  That is, paying attention to the molten aluminum alloy used as the material of the die cast product A, the second male screw portion 63 having a pitch different from that of the first male screw portion 62 is embedded and fixed to the solidified aluminum alloy. Yes. The core pin 6 is embedded and fixed in a state in which the core pin 6 is screwed to an aluminum alloy that solidifies after the molten aluminum alloy enters the screw groove. For this reason, the axial movement of the core pin 6 relative to the fixed mold 2 is suppressed. In addition, even if the core pin 6 tries to rotate in the loosening direction due to an input such as vibration, the first male screw portion 62 and the second male screw portion 63 having different pitches serve as stoppers that restrict the rotation of each other. Accordingly, the cast pin 6 is assembled to the fixed mold 2 by the first male screw portion 62 and the second male screw portion 63 having different pitches without adding parts such as bushes, and mass production of the die-cast as-cast product A. Even if vibration or the like is applied, the occurrence of loosening of the screw is suppressed.

  As a result, it is possible to suppress the occurrence of screw loosening due to the pitch difference between the two first male screw portions 62 and the second male screw portion 63 without adding any new parts, and the die of the fixed die 2. By simplifying the structure, it is possible to reduce the cost of mold production.

[Other features of die-cast core pin structure]
In the first embodiment, the clearance space 31 includes an annular gap 31d into which the molten aluminum alloy can enter, and a second male screw embedded space 31a that communicates with the annular gap 31d and covers the entire outer periphery of the second male screw portion 63. It was set as the structure which has.
With this configuration, in the molten metal filling process, the second male screw portion 63 having a pitch different from that of the first male screw portion 62 can be securely embedded and fixed in a locked state by the solidified aluminum alloy 41 solidified with the fixed mold 2. it can.

In the first embodiment, a configuration is provided in which a reverse taper communication space 31c is provided on the side of the annular gap 31d at a position connecting the annular gap 31d and the second male screw embedded space 31a in a direction opposite to the product draft from the fixed mold 2. did.
With this configuration, when the die-cast as-cast product A is extracted from the fixed mold 2, the presence of the reverse taper communication space 31c prevents the aluminum alloy from protruding from the annular gap 31d, and the die-cast as-cast product A as a casting burr. Can be prevented from being attached to.

In the first embodiment, the tip of the reverse taper communication space 31c is configured as an annular gap 31d provided at a position corresponding to the cavity 5 of the fixed mold 2.
With this configuration, the narrowest annular gap 31d is positioned in contact with the die-cast product A that is extracted from the fixed mold 2, so that it is possible to reliably eliminate the die-cast product A from being attached as a casting burr. .

In the first embodiment, a hexagonal hollow hole 65 opened from the fitting front end portion side toward the cavity 5 side is provided in the center portion of the shaft of the core pin 6. The hexagonal hollow hole 65 is set to a depth up to an intermediate position of the pin shaft portion 64 protruding into the cavity 5 of the fixed mold 2 in a state where the core pin 6 is assembled to the fixed mold 2. did.
With this configuration, when the core pin 6 is broken or the core pin 6 is damaged due to wear or the like, it is necessary to replace the core pin 6 with a new core pin 6. When the cast pin 6 is replaced, the head of the pin shaft portion 64 of the cast pin 6 is cut as shown in FIG. As a result of this cutting, the hexagonal hollow hole 65 is exposed to the outside, so that the hexagonal tool C is fitted into the hexagonal hollow hole 65 and the screw portion fitted to the fixed mold 2 is loosened. At this time, the solidified aluminum alloy 41 is broken. With this operation, the core pin 6 that needs to be replaced due to damage or the like can be extracted from the pin assembly recess 21.
Therefore, in mass production, the cast pin 6 can be replaced in a short time due to breakage, wear, etc., and the production stop time can be shortened.
Incidentally, in the case of the back pin, the production stop time was about 240 to 300 minutes, whereas in the case of the core pin 6 of the present application which is the front pin, the production stop time is about 10 minutes, and the production stop. A significant reduction in time was achieved.

  Thus, the die-casting pin structure for die casting of Example 1 satisfies all the requirements of the above “surface pin”, and even if the “surface pin” is used, a defect due to loosening (casting depth dimension NG) ) And can be replaced from the surface of the fixed mold 2 when worn or broken. As a result, it is possible to employ a “surface pin” that is advantageous in terms of cost and the like in a die casting machine that manufactures mass-produced products.

Next, the effect will be described.
In the die-casting pin structure for die casting of Example 1, the effects listed below can be obtained.

(1) It is assembled by tightening with a screw from the surface of the mold (fixed mold 2, movable mold 4) that creates the cavity space of the product shape and the cavity 5 formed in the mold (fixed mold 2). In a die casting core pin structure provided with a core pin 6,
A first female threaded portion 22 is provided at the most fitting portion of the pin assembly recess 21 formed in the mold (fixed mold 2).
A plurality of male screw portions (first male screw portion 62, second male screw portion 63) having different pitches are provided on the screw tightening shaft 61 of the core pin 6;
The first male screw part 62 provided at the most fitting part of the screw tightening shaft 61 is screwed into the first female screw part 22;
Other solid thread portions having a pitch different from the pitch of the first male thread portion 22 with respect to the solidified aluminum alloy 41 solidified in the clearance space 31 secured between the screw tightening shaft 61 and the pin assembly recess 21 ( A second male screw part 63) was embedded and fixed.
For this reason, it is possible to suppress the occurrence of screw loosening due to the pitch difference between the plurality of screws (the first male screw portion 62 and the second male screw portion 63) without adding new parts, and the mold structure. Simplification can reduce the cost of mold production.

(2) The clearance space 31 is an annular gap 31d into which the molten aluminum alloy can enter, and a second area that communicates with the annular gap 31d and covers the entire outer periphery of the other male screw portion (second male screw portion 63). Male screw embedded space 31a (male screw embedded space).
For this reason, in addition to the effect of (1), in the molten metal filling step, another male screw portion (second male screw portion 63) having a pitch different from that of the first male screw portion 62 is replaced with a mold (fixed die 2). The solidified aluminum alloy 41 solidified can be securely embedded and fixed in a locked state.

(3) On the side of the annular gap 31d where the annular gap 31d and the second male screw embedded space 31a (male screw embedded space) are connected, the reverse of the product draft from the fixed mold 2 (mold) A tapered communication space 31c was provided.
Therefore, in addition to the effect of (2), when the die-cast as-cast product A is extracted from the mold (fixed mold 2), the presence of the reverse tapered communication space 31c prevents the aluminum alloy from protruding from the annular gap 31d. Therefore, it is possible to prevent the die cast cast product A from being attached as a casting burr.

(4) The tip of the reverse taper communication space 31c is an annular gap 31d provided at a position matching the cavity 5 of the fixed mold 2 (mold).
For this reason, in addition to the effect of (3), the narrowest annular gap 31d comes into contact with the die-cast product A extracted from the mold (fixed mold 2), so that the die-cast product A as a casting burr is obtained. It can be surely solved that it is attached to.

(5) A hexagonal hollow hole 65 (polygonal cylindrical hollow hole) opened from the fitting front end portion side toward the cavity 5 side is provided in the center portion of the shaft of the core pin 6;
A pin shaft that protrudes into the cavity 5 of the fixed mold 2 (mold) in a state in which the hexagonal hollow hole 65 (polygonal cylindrical hollow hole) is assembled to the fixed mold 2 (mold). The depth was set up to the middle position of the portion 64.
For this reason, in addition to the effects of (1) to (4), it is possible to replace the core pin 6 due to breakage, wear, etc. in a short time during mass production, and the production stop time can be shortened.

  As mentioned above, although the die-casting pin structure for die-casting of this invention has been demonstrated based on Example 1, it is not restricted to this Example 1 about a concrete structure, It concerns on each claim of a claim Design changes and additions are allowed without departing from the scope of the invention.

  In the first embodiment, an example in which the first male screw portion 62 and the second male screw portion 63 are provided on the screw tightening shaft 61 of the core pin 6 as a plurality of male screw portions having different pitches has been described. However, the plurality of male screw portions having different pitches may be an example in which three or more male screw portions are provided, or may be an example in which two or more male screw portions having different pitch directions are provided. Further, as the second male screw portion, as shown in FIG. 10, a second male screw groove portion 63 ′ that is grooved at equal intervals with a pitch of zero may be provided.

  In Example 1, the example which applies the die-casting pin structure for die-casting of this invention to the die-casting machine which manufactures a transmission case was shown. However, the die-casting pin structure for die casting of the present invention can of course be applied to a die casting machine for producing die casting products other than the transmission case.

A Die-cast product 1 Fixed mold base 2 Fixed mold (mold)
21 Pin assembly recess 22 First female screw portion 23 Second female screw portion 3 Movable mold base 31 Clearance space 31a Second male screw embedded space (male screw embedded space)
31b Molten metal introduction space 31c Reverse taper communication space 31d Annular gap 4 Movable mold (mold)
41 Solidified aluminum alloy 5 Cavity 6 Casting pin 61 Screw tightening shaft 62 First male screw portion 63 Second male screw portion 64 Pin shaft portion 65 Hexagonal hollow hole (polygonal cylindrical hollow hole)

Claims (5)

In a die-casting pin structure comprising a die that creates a product-shaped cavity space, and a casting pin that is assembled by tightening with a screw from the surface of the cavity formed in the die,
A first female thread portion is provided at the most fitting part of the pin assembly recess formed in the mold,
A plurality of male screw portions having different pitches are provided on the screw tightening shaft of the core pin,
The first male screw portion provided at the most fitting portion of the screw tightening shaft is screwed into the first female screw portion,
A solid aluminum alloy solidified in a clearance space secured between the screw tightening shaft and the pin assembly recess is embedded and fixed with another male screw portion having a pitch different from the pitch of the first male screw portion. This is a die-casting pin structure for die casting. In the die cast core pin structure according to claim 1,
The clearance space has an annular gap into which a molten aluminum alloy can enter, and a male screw embedded space in a region communicating with the annular gap and covering the entire outer periphery of the other male screw portion. For cast pin structure. In the die-casting pin structure for die casting according to claim 2,
A die-casting pin for die-casting, characterized in that a reverse taper communication space is provided on the annular gap side at a position connecting the annular gap and the male screw embedding space in a direction opposite to a product drawing gradient from the mold. Construction. In the die-casting pin structure for die casting according to claim 3,
A die-casting pin structure for die casting, wherein a tip of the reverse tapered communication space is the annular gap provided at a position corresponding to a cavity of the mold. In the die-casting pin structure for die casting according to any one of claims 1 to 4,
In the central part of the shaft of the core pin, a polygonal cylindrical hollow hole opened from the fitting front end portion side toward the cavity side is provided,
The die-casting is characterized in that the polygonal cylindrical hollow hole is set to a depth up to a middle position of a pin shaft portion protruding into a cavity of the mold in a state where the core pin is assembled to the mold. For cast pin structure.