JP2550683B2 - Mold fastening method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for fastening a die, such as an induction heating forging die, in which the fastening portion is exposed to high temperature and requires strength.

[Prior Art] Conventionally, in an induction heating forging die, as shown in FIG. 19, in order to fasten a plurality of die constituent members 1, 2, 3, ... Bolts 7 on members 1, 2, 3, ...
It was fastened with bolts.

Further, as the mold constituent members, the mold constituent members 1, 2,
3,… Stacked as several pieces, these mold components 1, 2, 3,
Since it is advantageous in terms of thermal efficiency and cost of the die material to fasten the ... Through bolts 7 to form a laminated die, such a die configuration is adopted.

"Problems to be solved by the invention" However, in the conventional forging die fastening method as described above, 1) Strength; the high temperature strength of the bolt 7 is low, so that the required die fastening force is obtained and the die is used. In order to endure the mold separating force, the diameter of the bolts 7 is increased, the number of the bolts 7 is increased, and the fastening bolts 7 are arranged in a portion where the temperature rise is relatively small and are not exposed to high temperature. If necessary, the mold must be enlarged to prevent the bolt 7 from being exposed to high temperatures, so that the required strength of the bolt 7 must be obtained, and the size and shape of the mold are restricted. .

2) Workability; mold fastening bolts 7 are several mold constituent members
Since it goes through 1,2,3, ..., this bolt 7 becomes long,
A large size requires a device for bolt fastening, and the fastening work must be done every time the mold is replaced, and at that time, the entire mold must be removed from the induction heating device, resulting in poor workability. was there.

3) Internal temperature distribution: In an axially symmetric mold, the temperature in the circumferential direction of the mold becomes uneven at the bolt holes provided at several locations, which is the processing temperature of the workpiece inside and partially. And the properties of the finished forged product may be adversely affected.

4) Workability: Forging dies must have excellent high-temperature strength, but the materials of such dies generally have poor workability,
Since it takes a lot of time and labor for molding, increasing the number of the bolts 7 mentioned above means increasing the number of bolt hole machining.
This has been a cause of increasing the processing cost of the mold.

5) Seizure: Since the mold and fastening bolts 7 are at a high temperature of 1000 ° C or higher, seizure may occur at the fastening part of the mold. To remove the seized bolt 7, part of the mold should be removed. There was a problem that it had to be destroyed.

In FIG. 19, 8 is a reinforcing bolt, and 9 is a heater for heating.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a mold fastening method which solves the above problems of the conventional die fastening method.

"Means for Solving the Problem" The present invention has the following configuration in order to achieve the above object. That is, the flange portions respectively provided on the outer circumferences of a plurality of mold component members that are layered together are clamped by a clamp mechanism having a fixing member.

"Operation" Since the flanges of a plurality of mold components are clamped by the clamp mechanism having the fixing member, it is easy to increase the effective fastening area as compared with the fastening bolts.
Fastening is possible at high temperature, therefore it has sufficient strength, and since the fixing member is used to fix the side opposite to the die forging surface, there is no adverse effect on the die internal temperature, especially on the temperature distribution in the circumferential direction. Since it does not occur and seizure of the fastening portion is eliminated, and fastening at the high temperature portion is possible, the size of the die can be minimized, which reduces the die cost.

[Example] First, an example of a mold and a clamp mechanism for carrying out the method of the present invention will be described. 12 in FIGS. 1 and 2
Reference numerals a and 12b denote two die-forming plates of the die-forming members 12 which are formed into a plurality of layers and constitute the induction heating forging die 11 made of a rectangular parallelepiped. Recesses 13 each having a square cross section are formed on the outer circumferences of the adjacent die component members 12 on the respective die-matching surface sides over four circumferences. The bottom of the recess 13 is provided with a step, and as a result, the first flange 14 and the second flange 15 are formed on the outer surface 12c of the mold component 12.

In the second flange 15 of each mold component 12, a plurality of square plate-shaped headed bolts 16 are planted at right angles to the outer surface 12c of the mold component 12. A square pin hole 16a is formed in the head of the bolt 16. Bolt 16 is a mold component 12
Are provided at appropriate intervals in the circumferential direction. Further, the bolts 16 of the adjacent die component members 12 are formed so that the pin holes 16a of the upper and lower bolts 16 are vertically aligned as shown in FIGS.
An inverted L-shaped pin 17 having a rectangular cross section which is tightly fitted in these pin holes 16a is detachably fitted into a.

On the other hand, in the concave portion 13, adjacent die component members 12, 12
A fixing member 18 having a U-shaped cross section for fastening is tightly fitted detachably. That is, the fixing member 18 includes the first flange 14 and the second flange 14.
It is designed to be closely fitted to the flange 15. The fixing member 18 is provided at a position facing the bolt 16 portion,
A pin hole 19 is formed at a substantially central portion of the fixing member 18 so as to face the bolts 16 planted in the adjacent die component members 12. The size of the pin hole 19 is such that the head of the bolt 16 can slide and pass. Further, the maximum depth of the concave portion 13 (dimension δ'shown in FIG. 2) and the maximum thickness of the fixing member 18 (dimension δ'shown in FIG. 2) are the same.
The maximum thickness δ ′ of is equal to or less than the penetration depth δ of the electric current in the induction heating shown in FIG. Then, the fixing member 18,
The bolt 16 and the pin 17 constitute a clamp mechanism.

 Next, the method of the present invention will be described.

First, a plurality of required mold constituent members 12, 12, ... Are matched with each other, and a fixing member 18 is fitted into the recesses 13 on the outer periphery of each mold fitting portion with both ends of the projecting shape facing the recesses 13.

The pin holes 19, 19 of the fixing member 18 are fitted into the bolts 16, 16 of the adjacent die component members 12, 12 and the fixing member 18 is pushed into the recess 13.

Pins 17 are inserted into the pin holes 16a, 16a of the bolts 16, 16 of the die component members 12, 12 adjacent to each other outside the fixing member 18 from above to below.

Depending on these items, the mold components of each layer
12,12 ... are clamped. In addition, the clamp by the above-mentioned clamp mechanism is used for the mold component members 12, 12 ...
It will be done at the bolt planting section of.

Further, in order to release the clamp of the die component member 12, the pin 17 is pulled out from the bolt 16 provided in the required adjacent die component members 12 and 12, and the fixing member 18 is pulled out from the recessed portion 13 from the bolt 16. The fixing member 18 is removed.

According to this embodiment, a. Strength: Since the fixing member 18 can be arranged on the outermost peripheral portion of the mold, the fixing member for clamping the mold constituent member 12
The cross-sectional area of 18 can be made sufficiently larger than the cross-sectional area of the conventionally used fastening bolts, which contributes to maintaining the required strength of the fastening portion.

Further, in the conventional induction heating forging die shown in FIG. 19 using bolts, the bolt 7 is placed inside the maximum temperature range +50 isotherm curve (indicated by a mesh) by induction heating shown in FIGS. 20 and 21.
However, in the induction heating forging die of this embodiment, the mounting position of the fixing member 18 of the clamp mechanism is It can be the outermost part of the mold, and as shown in FIG. 4, the position of the fixing member 18 does not lie within the maximum temperature range +50 isothermal curve (mesh display part) due to induction heating. The mounting position of 18 can be set further below the mold.

As described above, in the present embodiment, the clamp mechanism is provided at the re-outer peripheral position of the mold, and relatively at the lower position of the mold, so that the amount of heat released by radiation and convection increases. Since the temperature rise is reduced and the maximum thickness of the fixing member is less than the current penetration depth δ in induction heating, the heat generation efficiency on the fixing member is significantly reduced. Rise decreases.

Therefore, as can be seen from the temperature rising curve of the mold clamping mechanism shown by the curve B with respect to the mold temperature rising curve shown by the curve A shown in FIG. 5, the clamping mechanism is higher than the mold temperature in the same heating time. Temperature of ΔT
It is lowered only by this and heat generation of the clamp part is suppressed.

Therefore, as the temperature decreases, the strength of the fixing member increases, and the strength is 1.5 times that of bolts having the same cross-sectional area.
Can rise ~ 2 times.

By the way, when examining the tensile strength, proof stress and allowable stress due to the temperature difference of the mold fastening member (material IN100), When the surface temperature of the mold is 980 ° C and the temperature of the conventional mold fastening bolt is also 980 ° C, the strength of the fixing member 18 of the present embodiment having the same cross-sectional area as the conventional bolt is By comparison, a) When the temperature of the fixing member 18 is 100 ° C lower than the mold temperature, the strength is 30/19 = 1.57 times that of the conventional bolt. When the temperature is 150 ° C lower, it has 33/19 = 1.73 times the strength of conventional bolts.

b. Workability: Since the mold is composed of several layers of mold constituent members 12 and these are clamped by the clamp mechanism having the fixing member 18, the mold constituent members are assembled for each layer of the mold,
It can be disassembled, at the time of mold replacement, it is possible to replace any mold component layer of each mold component layer,
The mold can be easily replaced, so that the time required for the mold replacement can be shortened and the workability is greatly improved.

c. Internal temperature distribution: Since the fixing member 18 is used to fix the surface on the side opposite to the die forging surface, this has almost no effect on the temperature inside the die, particularly on the circumferential temperature distribution of the die. .

d. Workability: Generally, since heat-resistant materials have extremely poor machinability, the use of the fixing member 18 without using bolts does not process the bolt holes, so that the processing cost is significantly reduced.

e. Seizure: Since the fastening method using bolts is not used, seizure does not occur due to the high heat of the bolts.

f. Economical efficiency: In the conventional bolt fastening die, if the fastening at the high temperature part is avoided, the die inevitably becomes large and the die weight increases, but in the present embodiment, the clamping mechanism at the high temperature part is used. Since it is possible to fasten the mold, the size of the mold can be reduced to the minimum required size, which can reduce the cost of the mold (hereinafter, the first embodiment).

In the first embodiment, the mold is made of a rectangular parallelepiped, but the mold is not limited to this, and may be a cylindrical mold or a mold having another shape as long as the present invention can be carried out ( Second embodiment).

Further, in the first embodiment, the fixing member 18 was fitted directly to the mold component member 12, but the present invention is not limited to this. For example, as shown in FIG. 6, the fixing member 18 is surface-treated by alumina spraying. A fixing member 18 which has been subjected to surface treatment 31 and which has been subjected to a surface treatment is fitted into the concave portion 13 (the above third embodiment), or as shown in FIG. For example, the fixing member 18 is fitted into the concave portion 13 with the glass wool 41 interposed (the fourth embodiment described above) to insulate the mold from the fixing member 18 to eliminate the possibility of marking. At the same time, the amount of heat transferred from the mold to the fixing member may be suppressed.

Further, in the first embodiment, the contact surface 18a of the fixing member 18 to the first flange 14 and the second flange 15 of the mold is parallel to the mold mating surface 12d, but the invention is not limited to this. For example, as shown in FIGS. 8 and 9, the first flanges 53,5 are attached to the mating surfaces 52a of the metal component members 52,52 of the cylindrical mold 51.
The upper and lower contact surfaces 53a of the U-shaped fixing member 54 to 3 are tapered surfaces, and the fixing member 54 is attached to the mold constituent members 52, 52 by moving in the directions of arrows A and B shown in FIG. The die forming members 52, 52 may be clamped by the fixing portion 54 (the fifth embodiment as described above). Further, as shown in FIG. A substantially U-shaped fixing member 63 having upper and lower abutting surfaces on the first flanges 62, 62 formed into tapered surfaces may be detachably attached to the 61 as in the fifth embodiment (above sixth embodiment).
Example).

Further, in each of the above embodiments, the mold component 12, 52,
Although the U-shaped fixing members 18, 54 and 63 were fitted to the respective 61 and the respective mold constituent members were fastened, the present invention is not limited to this.
As shown in Fig. 11, the rectangular molds are
With respect to the mating surfaces 71a, 71a of 71, 71, a concave portion 72 having a symmetrical and identical shape and having an I-shaped cross section is formed.
An integral fixing member 73 or a plurality of fixing members 74 tightly fitted in the concave portion 72 are formed with an I-shaped cross section shown in FIG. 13, and the fixing member 73 or the plural fixing members 74 integral with the concave portion 72 are formed.
May be closely fitted.

In this case, the upper and lower flanges (protrusions) of the fixing member 73 or the fixing member 74 are securely locked to the mold forming members 71, 71, so that these mold forming members 71, 71 are strongly clamped. The maximum plate thickness of each fixing member 73, 74 is set to a plate thickness δ'which is equal to or less than the penetration depth δ of the electric current in the induction heating of the mold as in the first embodiment. By thus setting the maximum plate thickness of the fixing members 73 and 74 to δ ′, the heat generation efficiency in the clamp part is reduced, the heat generation of the fixing members 73 and 74 is suppressed, and the fixing is performed during induction heating of the mold. The temperature of the members 73 and 74 is 100 to 200 ° C. lower than the mold temperature.

Then, when the penetration depth δ of the electric current in the induction heating is shallow, the number of fixing members is increased to maintain the strength of the fixing members. That is, when the number of fixing members is increased by using the plurality of fixing members 74, the induced current becomes difficult to flow, heat generation of the fixing members is suppressed, and the large number of fixing members 74 causes the plurality of fixing members 74 to cooperate with each other. Work to exert sufficient strength overall. Therefore, the fixing member 74 surely prevents the mold opening (the seventh embodiment).

In addition, in the seventh embodiment, the I-shaped fixing member 73 or the fixing member 74 is fitted in the recess 72 to form a mold component member.
71, 71 are clamped, but not limited to this, for example, as shown in FIG. 14, in a rectangular mold, symmetrical with respect to the mating surfaces 81a, 81a of the mold constituent members 81, 81 and A recessed portion 82 having the same shape and having a stepped cross section is formed, while
15 and 16, a fixing member 83 or a plurality of fixing members 84 that are closely fitted to the recess 82 are formed in a stepped shape shown in FIGS. 15 and 16, and the fixing member 83 or the fixing members 83 that are integrated into the recess 82 are formed. The fixing member 84 may be closely fitted.

In this case, both lateral surfaces of the fixing member 83 or the fixing member 84 are tapered surfaces, and since these tapered surfaces are securely engaged with the mold constituent members 81, 81, these mold constituent members 81,
Strongly clamp 81. The maximum plate thickness of each fixing member 83, 84 is set to a plate thickness δ'which is equal to or less than the penetration depth δ of the current in the induction heating of the mold as in the first embodiment. By setting the maximum plate thickness of the fixing members 83, 84 to δ ′ in this way, the heat generation efficiency in the clamp portion is reduced, and the fixing member 8
Heat generation of 3,84 is suppressed. Further, when the penetration depth δ of the electric current in the induction heating is shallow, the number of the fixing members is increased to maintain the strength of the fixing members, so that the fixing member 74 reliably prevents the mold opening from the seventh embodiment. The same applies to the example (the above is the eighth embodiment).

Further, in the first embodiment, an example in which the present invention is applied to an induction heating forging die has been described, but the present invention is not limited to this, and may be applied to a commonly used press die and other dies. It is also possible (the above is the ninth embodiment).

<Example of die heating test> A die 100 is laminated with die components 91, 92, 93, 94, and a carbon die 99 clamped by the die fastening fixing members 95, 96, 97, 98 is heated by a heater 100. In a heated test,
When the mold constituent members 91, 92 are heated to 850 ° C, the temperature of the thick-walled thick-walled fixing members 95, 96 is 750 to 800 ° C, and the temperature of the fixing members 97, 98 consisting of multiple thin plates. 700-750 ° C
The maximum temperature difference between the mold and the fixing member was 150 ° C.

In the Ni alloy mold, since the emissivity of the fixing member is about 70% of that of the carbon mold, the temperature difference between the mold and the fixing member is larger than in the case of the carbon mold.

[Advantages of the Invention] According to the present invention, the flange portions respectively provided on the outer peripheries of a plurality of mold constituent members to be layered together are clamped by a clamping mechanism having a fixing member. Strength: The fixing member related to the clamp of the mold component can have a cross-sectional area sufficiently larger than the cross-sectional area of the bolt used to fasten the mold component conventionally. The fastening strength is increased and the mounting position of the fixing member can be set to the outermost peripheral part of the mold, so that the fixing member does not reach the maximum temperature range due to induction heating and heat generation of the fixing member is suppressed. Then, the temperature of the fixing member becomes lower than the mold temperature, and the strength of the clamp mechanism portion including the fixing member also increases in this respect. Therefore, the fixing member can be provided in the high temperature portion of the mold without restricting the shape of the forged surface to obtain sufficient mold fastening strength of the clamp mechanism.

b. Workability: It is possible to assemble and disassemble the die component members of each layer of the die, and to replace any die component layer among the die component layers when exchanging the die. Therefore, the mold can be easily replaced, so that the time required for the mold replacement can be shortened and the workability is greatly improved.

c. Internal temperature distribution: Since the fixing member is used to fix the surface on the side opposite to the die forging surface, it is possible to eliminate the adverse effect on the temperature inside the die, especially on the circumferential temperature distribution of the die. it can.

d. Machinability: Generally, heat-resistant materials have extremely poor machinability, so using fixing members without bolts does not require machining of bolt holes, thus significantly reducing machining costs.

e. Seizure: Since the bolting method is not used, seizure due to high heat of the bolt does not occur.

f. Economical: Since the clamping mechanism can be used in the high temperature area, the size of the mold can be reduced to the minimum required size, which can reduce the mold cost. Since the fixing member functions to reduce the heat radiation loss of the mold, the heat efficiency of the mold is improved, which allows the induction heating coil to be downsized, which also improves the economical efficiency.

g. Applicable range: Not limited to induction heating forging dies, it can be applied to commonly used press dies and other dies, and has versatility.

[Brief description of drawings]

1 to 5 show one embodiment of the method of the present invention. FIG. 1 is a longitudinal sectional view of an essential part, and FIG. 2 is a sectional view showing a disassembled state of a mold constituent member and a fixing member. Fig. 3 and Fig. 3 are perspective views showing longitudinal cross-sections of essential parts, Fig. 4 is a cross-sectional view showing that the fixing member is not positioned in the maximum temperature region due to induction heating, and Fig. 5 is an ascending mold and clamp mechanism. FIG. 6 is a characteristic view showing a temperature state, FIG. 6 is a longitudinal sectional view showing a third embodiment of the method of the present invention, and FIG.
FIG. 8 is a vertical sectional view showing a fourth embodiment of the method of the present invention, and FIGS. 8 and 9 show a fifth embodiment of the method of the present invention.
8 is a sectional view taken along line VIII-VIII of FIG. 9, FIG. 9 is a longitudinal sectional view of an essential part, and FIG. 10 is a longitudinal sectional view of an essential part showing a sixth embodiment of the method of the present invention. FIG. 11 is a perspective view showing a seventh embodiment of the method of the present invention, FIG. 11 is an exploded perspective view, FIG. 12 is a perspective view of an integral fixing member, and FIG. 14 is a perspective view of a fixing member of the body, FIGS. 14 to 16 show an eighth embodiment of the method of the present invention, FIG. 14 is an exploded perspective view, FIG. 15 is a perspective view of an integral fixing member, FIG. 16 is a perspective view of a plurality of fixing members, FIGS. 17 and 18 show a mold for a mold heating test, FIG. 17 is a schematic plan view, FIG. 18 is a schematic side view, and FIG. 19 to 21 show an embodiment of a conventional mold fastening method. Fig. 19 is a longitudinal sectional view of the main part, and Figs. 20 and 21 show the maximum temperature range by induction heating of the mold. Sectional drawing which shows that the position of a fastening bolt is applied Is. 11 …… Induction heating forging die, 12,52,61,71,81 …… Mold component, 12d, 52a, 71a, 81a …… Mating surface, 13,72,82 …… Concave, 14,53, 62 …… First flange, 15 …… Second flange,
16 …… Bolt, 17 …… Pin, 18,54,63,73,74,83,84 ……
Fixing member, 31 …… Surface treatment, 41 …… Heat insulation layer.

Claims (6)

(57) [Claims] 1. A method of fastening a die, comprising: clamping a flange portion provided on the outer periphery of each of a plurality of die forming members to be die-layered by a clamping mechanism having a fixing member. 2. A plurality of mold component members are provided with a groove extending in a direction in which the fixing member is fitted, the fixing member is fitted in the groove, and the fixing member is fixed in a direction intersecting with a fitting direction of the fixing member. The method of fastening a mold according to claim 1, wherein a locking portion provided on the member is locked to the mold constituent member to prevent the mold opening of the plurality of mold constituent members. . 3. The method of fastening a mold according to claim 1, wherein the groove and the fixing member are U-shaped in cross section. 4. The method for fastening a mold according to claim 1, wherein the groove and the fixing member have an I-shaped cross section. 5. A mold comprising a plurality of mold constituent members is configured as an induction heating mold heated by induction heating, and a maximum thickness of the fixing member is set to a penetration depth of an electric current in the induction heating of the mold. The thickness is formed to be equal to or less than a predetermined value, the fixing member is engaged with the flange portion, and the plurality of mold constituent members are clamped.
A method for fastening a mold according to any one of the items. 6. A heat insulating material layer is interposed between the flange portion and the fixing member, the fixing member is fitted to the flange portion, and the plurality of mold component members are clamped. A method for fastening a mold according to any one of claims 1 to 5.