JPH07116808A - Die for die casting - Google Patents

Abstract

PURPOSE:To reduce the play of a slide core by providing a side core having plural positions of clearance and slidably fixing to a fixed main die or a movable main die and constituting it so as to cancel the clearance in the increased part and in the decreased part. CONSTITUTION:The clearances having C0, C1, C2 are arranged in the sliding parts between the fixed main die or the movable main die 3 and the slide core 7 slidably fitted. When the slide core 7 expands by heat, there are the increasing parts and the decreasing parts in plural clearances arranged between the fixed main die and the movable main die 3, and the slide core 7. The clearance is made small before the slide core 7 expands by heat by constituting it so as to cancel the clearances in the increasing part and in the decreasing part. By this method, the play of the slide core can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a die casting mold having a slide core which is fitted in a fixed main mold or a movable main mold and slides.

[0002]

2. Description of the Related Art Conventionally, as a die casting mold having a slidable slide core, for example, there is a device described in Japanese Utility Model Laid-Open No. 3-57464. In the die casting mold having the slide core of the above invention, a groove for the slide core to slide is formed in the movable main mold, and a slide sticking plate is provided on the facing surface of the movable main mold that is in contact with the bottom surface of the slide core. Is fixed. In the die-casting die having the above structure, the slide core is fitted in the groove formed in the movable main mold, and the bottom surface of the slide core comes into contact with the slide sticking plate to slide.

[0003]

However, the above-mentioned prior art has the following drawbacks. That is, when casting starts, the slide core causes thermal expansion as the number of shots increases (since the slide core forms a cast product,
Since the molten metal comes into direct contact, the temperature rises more than the main mold). When the slide core thermally expands, the clearance between the slide core and the movable main die decreases, causing galling, resulting in malfunction.

In order to prevent the above-mentioned galling, a clearance considering thermal expansion is provided in the sliding portion between the slide core and the movable main die. For example, when the width of the slide core is about 100 mm, the clearance is 0.08 to 0.
It is about 1 mm. The reason is that the temperature difference between the slide core and the movable main mold is about 100 ° C., and the thermal expansion amount of the slide core having a width of 100 mm is about 0.1 mm, and it is about 0.05 mm on one side. Therefore, if the amount of the clearance is set, the slide core can slide without galling even if the temperature of the slide core rises.

However, since the slide core slides in a loose state during the start of casting or during the temperature rise of the slide core, the precision of the cast product formed by the slide core varies. In addition, since the clearance is large, the slide core is displaced by the casting pressure by the amount of the clearance for each shot, and the accuracy is not the same as the above. In particular, it is a big defect in precision die casting.

Therefore, the present invention was developed in view of the above-mentioned drawbacks of the prior art, and a die casting mold capable of reducing the play between the start of casting of the slide core and the heating of the slide core to a high temperature. For the purpose of providing.

[0007]

DISCLOSURE OF THE INVENTION The present invention provides a die casting mold having a slide core which is slidably fitted to a fixed main mold or a movable main mold at a plurality of clearances. At least one of them is configured to be different from other clearances.

[0008]

In the present invention, when the slide core thermally expands, the plurality of clearances provided in the fixed main mold or the movable main mold and the slide core have an increasing portion and a decreasing portion. The clearance before the thermal expansion of the slide core can be made small by compensating the clearance between the increasing portion and the decreasing portion.

[0009]

Embodiment 1 FIGS. 1 to 8 show the present embodiment, FIG. 1 is a vertical sectional view of a die casting mold, FIG. 2 is a vertical sectional view of a mold opened state, and FIG. 3 is XX 'of FIG. FIG. 4 is a cross-sectional view of the movable main mold and the slide core, FIG. 5 is a plan view showing a state where the slide core is thermally expanded by a dotted line, FIGS. 6 and 7 are graphs, and FIG. 8 is a modification. It is a cross-sectional view showing an example.

Reference numeral 1 is a fixed main mold, and the fixed main mold 1 includes an inclined pin 5, a stopper 6, a fixed core 2 and a mold sleeve 23.
And are stuck. Fixed main mold 1 is a casting machine (not shown)
Is fixed to the stationary platen 26 of FIG. The tilt pin 5 has a function of moving the slide core 7 in the directions of arrows A and B. Reference numeral 8 denotes an inclined pin hole through which the inclined pin 5 penetrates.

Reference numeral 3 denotes a movable main mold, and the movable main mold 3 has a movable core 4, a holder 9 and a shunt 2 for changing the flow of molten metal.
0 is fixed to the movable platen 27 of the casting machine (not shown) via the spacer block 16. The fixed main mold 1 and the movable main mold 3 are shown in FIG. At the position of L, the mold is opened by a casting machine (not shown).

Reference numeral 18 is a cast product, which is a fixed core 2 and a movable core 4.
And the slide core 7 are formed. Reference numeral 17 denotes a cavity formed in the movable core 4. A hanging bolt 10 is directly connected to the slide 7 via a spring 11 and a holder 9, and holds the slide 7 raised after the mold is opened at that position.

FIG. 2 shows the state after the mold is opened. Denoted at 12 is an extruding pin, which is constructed so that it can be fitted into the movable core 4 and can slide. The left end portion of the push pin 12 is fixed to the push plate 14 and the push plate 15. 13 is a retan pin,
As with the push-out pin 12, its left end is the push-out plate 1
It is fixed to 4, 5 and is configured so that it can be fitted into the movable main mold 3 and can slide. The right end of the retan pin 13 is the P. It is in contact with the L surface and has push plates 14, 1
It has a function to push back 5 to the state of FIG.

Reference numeral 21 denotes molten metal poured into the mold sleeve 23, and 19 denotes a runner through which the molten metal passes. Reference numeral 22 denotes a plunger chip, which is directly connected to a casting machine (not shown) and slides between a die sleeve 23 and a machine sleeve 24. Reference numeral 25 denotes a protrusion provided on the movable main mold 3, which is fitted with the slide core 7. Protrusion 2
The shape of No. 5 is shown in FIGS.

FIG. 3 is a view taken in the direction of arrows XX ′ in FIG. 2, and the entry dimension shows an example of the size of the slide core 7. The sliding portion between the movable main die 3 and the slide core 7, C _0, as shown in FIG. 4,
Clearances of C ₁ and C ₂ are provided. C ₀ is a general clearance and is formed to 0.08 to 0.1 mm.

C ₁ is formed by the slide reference surface 30 of the protrusion 25 of the movable main mold 3 and the slide reference surface 31 of the slide core 7, and is set to 0.01 mm. Similarly, C ₂ is formed by the sliding reference surface 32 of the movable main mold 3 and the sliding reference surface 33 of the slide core 7, and is set to 0.06 mm. Further, the movable main mold 3 is provided with a sliding surface 37 on which the sliding core 7 abuts and slides.

The operation of the apparatus having the above structure will be described below. FIG. 1 shows a main mold 1 fixed by a casting machine (not shown).
After the movable main mold 3 and the movable main mold 3 are clamped, the molten metal 21 is poured into the mold sleeve 23 and the machine sleeve 24, and is pushed by the plunger tip 22 in the direction of the arrow to pass through the runner 19 to form the cavity. 17 shows a state of being filled in the inside. Next, after the casting 18 is cooled and solidified, the mold is opened by a casting machine (not shown). The state of completion of mold opening is shown in FIG.

During mold opening, the slide core 7 is moved in the direction of arrow A by the inclined pin 5 and finally moved by l in FIG. 2 to be completely released from the casting 18. That state is the suspension bolt 10 and the spring 1 provided on the holder 9.
Maintained at 1. Next, in FIG. 1, an extrusion rod (not shown) of the casting machine pushes out the extrusion plate 14 in the direction of arrow E,
The push pin 12 is advanced in the direction of arrow E,
Is released from the cavity 17.

After the mold is released, the extrusion rod (not shown) of the casting machine retreats in the direction of arrow F, but the extrusion plates 14 and 15 remain in the above state. Next, when the mold is clamped by a casting machine (not shown), the retan pin 13 projects from the movable main mold 3, so that the P.P. Since it abuts against the L surface and is pushed back by closing the mold (in the direction of arrow F), the pushing plates 14 and 15 are pushed back in the same manner. Similarly, the push-out pin 12 is pushed back to return to the state of FIG. 1 when the mold clamping is completed.

In the slide core 7 in the state of FIG. 2 during mold clamping, the inclined pin 5 abuts the inclined pin hole 8 and the slide core 7 is moved in the direction of arrow B to the state of FIG. 1 after mold clamping. Will be returned. After that, the above operation is repeated.

When repeatedly continuously cast, the slide core 7
Since it forms the cast product 18 of FIG. 1, it directly receives the heat of the molten metal and gradually undergoes thermal expansion. The mold temperatures of the movable main mold 3 and the slide core 7 have no temperature difference in the initial stage (before the start of casting), but during continuous casting, the slide core 7 becomes about 100 ° C. higher than the movable main mold 3.

An example of thermal expansion of the slide core 7 is shown in FIG.
And the state of thermal expansion when the slide core 7 has reached a high temperature is indicated by a dotted line. The graph of FIG. 6 shows the amount of thermal expansion of the slide core 7 due to temperature change, and the material of the die in this case is equivalent to SKD61 (alloy tool steel material),
This is the case where the coefficient of linear expansion α = 10 × 10 ⁻⁶ / ° C. For example, the width of the slide core 7 is L = 10 as shown in FIG.
If it is 0 mm, it will expand by 0.1 mm when the temperature rises by 100 ° C. When the temperature difference between the slide core 7 and the movable main mold 3 reaches 100 ° C. from the start of casting, the slide core 7 sequentially expands.

The above-mentioned state and C _{1 of} FIG.
The state where 0.01 mm and C ₂ = 0.06 mm is shown below. The graph of FIG. 7 shows changes in the clearances of C ₁ and C ₂ due to the temperature difference between the slide core 7 and the movable main mold 3. For example, the clearance of C ₁ is initially 0.01 m.
m, but C ₁ increases as the temperature difference increases, and C ₁ = 0.025 mm at 100 ° C. (C ₁ =
0.01 + Δl / 2 = 0.01 + 0.03 / 2 = 0.0
25, when L = 30 mm).

Therefore, the initial clearance C _{1 of the} reference surface for eliminating the play in the direction of the arrow in FIG. 4 is 0.025 mm at the maximum. On the other hand, the clearance of C ₂ in FIG. 4 is initially C ₂ =
Although it is a backlash of 0.06 mm, it gradually decreases to 0.06 to 0.01 mm as shown in FIG.
Then, C ₂ = 0.01 mm (C ₂ = 0.06-Δl
/2=0.06-0.1/2=0.01, L = 100m
when m).

When the point where C ₁ and C ₂ intersect in FIG. 7 is point X (the point where the clearance between C ₁ and C ₂ is equal), the temperature difference increases from the start of casting until the point reaches X. 4 reduces the play of the slide core 7 with the sliding reference surfaces 30 and 31 of FIG. 4 as a reference, and after reaching the point X, the sliding reference surfaces 32 and 33 replace the above. The clearance is 0.01 to 0.0 from the initial point to point X (76.92 ° C).
21 mm and 0.021 to 0.01 mm after the X point. Therefore, the clearance corresponding to the amount of thermal expansion of the slide core 7 during casting can be reduced, so that the slide core 7
You can reduce the backlash.

According to this embodiment, the clearance when the temperature difference between the fixed main mold or the movable main mold and the slide core occurs can be minimized, so that the play of the slide core during casting can be reduced. Therefore, the displacement of the slide core due to the casting pressure does not occur, and the precision of the cast product formed by the slide core can be improved. Further, since the above-mentioned displacement does not occur, the slide core can slide smoothly and no galling occurs.

Incidentally, instead of the protrusion 25 shown in FIG.
As shown in FIG. 5, a concave portion 34 may be formed in the movable main mold 3, and the key 35 may be fixed to the concave portion 34 with a bolt 36.

[0028]

Embodiment 2 FIGS. 9 to 11 show the present embodiment, FIG. 9 is a cross-sectional view of a movable main mold and a slide core, FIG. 10 is a plan view of the slide core, and FIG. 11 is a graph. In the present embodiment, the same components as those in the first embodiment are designated by the same reference numerals, and the description thereof will be omitted. Only different portions will be described.

A recess 42 is provided in the protrusion 25 of the movable main mold 3. A protrusion 43 is provided on the slide core, and the protrusion 43 is configured to enter the recess 42. A sliding reference surface 40 forming a clearance of C ₃ is provided on the side surface of the recess 42 of the movable main mold 3. A slide reference surface 41 that forms a clearance of C ₃ is provided on the side surface of the protrusion 43 of the slide core 7. Figure 10
Is a plan view, and the entry dimension shows an example of the size of the slide core 7. The clearances C ₀ and C ₁ are the same as in the first embodiment, and C ₀ = 0.08 to 0.1 mm and C ₁ =
The clearance C ₃ is 0.01 mm and the clearance C ₃ is 0.02 mm.

The operation of the apparatus having the above structure will be described below.
FIG. 11 is a graph showing changes in the clearances C ₁ and C ₃ due to the temperature difference during casting of the slide core 7 and the movable main mold 3 shown in FIG. In FIG. 11, X point is C ₁ and C
_It shows that ₃ is equal to. Therefore, from the start of casting to the point X where the temperature difference reaches approximately 40 ° C., the clearance portion of C ₁ , that is, the sliding reference surfaces 30 and 31 in FIG. When there is a difference, the clearance portion of C ₃ , that is, the sliding reference surfaces 40 and 41 in FIG. 9 are replaced by the reference surfaces to reduce the play of the slide core 7. At point X, the temperature difference is about 40 ° C, the clearance is maximum, and it is 0.0 at the initial temperature to 100 ° C
It changes from 1 to 0.016 to 0.01 mm.

Compared to the first embodiment, the width L of the sliding reference surface
By reducing the value of (2), the thermal expansion amount of the slide core 7 can be reduced (L = 3 in the first embodiment as shown in FIG. 3).
In contrast to 0 mm and L = 100 mm, in this embodiment, L = 30 mm and the recess 42 of FIG. 9 was L = 20 mm.
Therefore, the sliding clearance is smaller than that in the first embodiment). According to this embodiment, the same effect as that of the first embodiment can be obtained, and the play of the slide core can be further reduced as compared with the first embodiment.

[0032]

Third Embodiment FIGS. 12 to 16 show the present embodiment.
Is a cross-sectional view of the movable main mold and the slide core, and FIG. 13 is FIG.
14 is an enlarged cross-sectional view of a main part of FIG. 14, FIG. 14 is a plan view of a slide core, FIG. 15 is a graph, and FIG. 16 is a cross-sectional view showing a modified example.
In the present embodiment, the same components as those in the first embodiment are designated by the same reference numerals, and the description thereof will be omitted. Only different portions will be described.

A sliding reference surface 50 forming a clearance of C ₄ is provided on the movable main mold 3, and a sliding reference surface 51 is provided on the sliding core 7.
Are provided in each. The filled dimensions in FIG. 14 show an example of the size of the slide core 7. C ₀ is the same as a C ₀ = 0.08～0.1Mm as in Example 1, the clearance C ₄ is in the C ₄ = 0.01 mm.

The operation of the apparatus having the above structure will be described below.
FIG. 15 shows changes in the clearance C ₄ due to a temperature difference during casting between the slide core 7 and the movable main mold 3 shown in FIG. In FIG. 15, the initial clearance C ₄ is 0.0.
1 mm, but C'even when the temperature difference reaches 100 ° C
₄ = 0.015 mm and it only increases slightly 0.005 mm C _'4 clearance not to affect the backlash. The above-mentioned state is shown in FIG. FIG. 13 shows FIG.
The case where the slide core 7 is raised by 100 ° C. from the state 2 (the state in which there is no temperature difference between the movable main mold 3 and the slide core 7) is shown. The dotted line in FIG. 13 shows the state of thermal expansion when the sliding surface 37 is used as a reference (C ′ ₄ = C ₄ +0.005 mm).

According to the present embodiment, the same effect as that of the first embodiment can be obtained, and unlike the above-mentioned respective embodiments, FIG.
The play of the slide core in the direction of the arrow 2 can be reduced even during casting.

[0036]

As described above, according to the die-casting mold of the present invention, the clearance at one or a plurality of positions of the sliding portion between the fixed main mold or the movable main mold and the slide core can be reduced to another. By making the clearance different from the clearance of the sliding portion, it is possible to reduce the play of the sliding core.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing a first embodiment.

FIG. 2 is a vertical sectional view showing the first embodiment.

FIG. 3 is a view taken along the line X-X ′ of FIG.

FIG. 4 is a cross-sectional view showing the first embodiment.

FIG. 5 is a plan view showing the first embodiment.

FIG. 6 is a graph showing Example 1.

FIG. 7 is a graph showing Example 1.

FIG. 8 is a cross-sectional view showing a modified example of the first embodiment.

FIG. 9 is a cross-sectional view showing a second embodiment.

FIG. 10 is a plan view showing a second embodiment.

FIG. 11 is a graph showing Example 2.

FIG. 12 is a cross-sectional view showing a third embodiment.

13 is an enlarged cross-sectional view of a main part of FIG.

FIG. 14 is a plan view showing a third embodiment.

FIG. 15 is a graph showing Example 3.

FIG. 16 is a cross-sectional view showing a modified example of the third embodiment.

[Explanation of symbols]

 1 Fixed main type 2 Fixed core 3 Movable main type 4 Movable core 5 Tilt pin 6 Stopper 7 Sliding core 25 Projection

Claims (1)

[Claims] 1. A die casting mold comprising a slide core which is slidably fitted to a fixed main mold or a movable main mold at a plurality of clearances. A die-casting mold characterized in that the clearance that increases due to thermal expansion is set to be small among the clearances that are formed, and the clearance that decreases due to thermal expansion is set to be large.