JP5555078B2 - Mold preheating apparatus and preheating method - Google Patents

Description

  The present invention relates to a preheating device and a preheating method for preheating a mold.

  When casting a workpiece such as an automobile part, work efficiency can be improved by preheating the mold before pouring the molten metal into the mold. For example, casting can be resumed quickly by preheating the mold while the casting is temporarily stopped, such as a work break. And as a preheating apparatus for preheating a metal mold | die, there exists a thing which heats a metal mold | die by sending a hot air into a gate from the burner installed outside the metal mold | die and a ventilation means (for example, refer patent document 1). .

JP 2000-334557 A

In the conventional preheating apparatus described above, it is difficult to position the burner and the air blowing means with respect to the mold, and there is a problem that the combustion state of the burner must be monitored.
Further, since the burner is burned outside the mold, there is a problem that the temperature around the mold rises and affects the working environment.
Furthermore, since the temperature of the hot air decreases before the hot air reaches the internal space from the gate, there is a problem that the entire mold is not heated uniformly.

  Therefore, the present invention provides a preheating device and a preheating method that solve the above-described problems, can easily position the heater in the internal space of the mold, and can effectively heat the mold by the heater. This is the issue.

In order to solve the above-mentioned problems, the present invention is a preheating device for heating a mold using an electrothermal heater, and is inserted into a hole formed in the mold from the inner space side of the mold. A first heater and a second heater arranged in the internal space of the mold are provided , and the hole is a gate formed in the mold .

In this configuration, the entire mold can be uniformly heated from the inner space of the mold. In addition, since the heat of the heater is hardly dissipated to the external space of the mold, the influence on the work environment can be reduced.
In particular, the mold is divided into a first mold and a second mold, and the second heater is placed in the internal space closed by the first mold and the second mold. When arranged, the second heater is arranged in the sealed space, so that the heating efficiency of the mold can be increased.

  Moreover, since an electrothermal heater is used, it is easy to manage the heating state. For example, the working efficiency can be improved because the mold can be preheated even during a time when it is difficult to ensure a sufficient monitoring system, such as a work break.

Moreover, the preheater can be easily positioned with respect to the mold by inserting the first heater into the hole.
In particular, when the first heater is formed with a fitting portion fitted into the hole portion, and the outer peripheral surface of the fitting portion is formed to follow the inner peripheral surface of the hole portion, preheating is performed. The device can be accurately positioned with respect to the mold.
Furthermore, by forming the outer peripheral surface of the fitting portion to follow the inner peripheral surface of the hole portion, the contact area between the fitting portion and the mold is increased, and the heat conduction efficiency from the first heater to the mold is increased. Since it becomes high, a metal mold | die can be heated effectively.

In addition, a preheating apparatus can be attached to a metal mold | die without processing an existing metal mold | die by utilizing the gate formed in the said metal mold | die as said hole part.
In addition, since the gate is closed by the first heater, the heat in the internal space is hardly radiated to the outside of the mold through the gate, so that the heating efficiency of the mold can be increased.

When a stalk communicating with the hole is provided on the outer surface of the mold and the first heater protrudes into the stalk, it is not necessary to provide another heater in the stalk. A mechanism for preheating can be simplified.
The second heater is preferably disposed in the inner space of the mold in a state of being separated from the inner surface of the mold.
Furthermore, when the power supply cable is electrically connected to the first heater and the second heater, and the power supply cable is inserted into a wiring pipe disposed in the internal space of the mold, It is desirable to provide a heat shield plate between the second heater and the wiring pipe for blocking heat generated by the second heater.

  A mold preheating method using the above preheating device, wherein the hole is formed in the first mold, and the first heater is moved from the inner space side of the mold to the hole. Inserting and attaching the preheating device to the first mold; attaching the second mold to the first mold through a spacer; and the first mold and the second mold A step of disposing the second heater in the internal space closed by a mold and a step of generating heat from the first heater and the second heater can be provided.

In this method, by inserting the first heater into the hole, the preheating device can be easily positioned with respect to the mold, and the entire mold can be uniformly heated from the internal space of the mold. At this time, since the heat of the heater is hardly dissipated to the external space of the mold, the influence on the work environment can be reduced. Moreover, since an electrothermal heater is used, it is easy to manage the heating state.
Moreover, it becomes easy to arrange | position a preheating apparatus inside a metal mold | die by interposing a spacer between a 1st metal mold | die and a 2nd metal mold | die, and enlarging the internal space of a metal mold | die. Moreover, the power feeding cable connected to the preheating device can be extended to the outside from between the first mold and the second mold.

  In the preheating device and the preheating method of the present invention, the entire mold can be uniformly heated and the influence on the working environment can be reduced. Furthermore, it becomes easy to manage the heating state. Further, the preheating device can be easily positioned with respect to the mold.

It is the perspective view which showed the preheating apparatus of this embodiment. It is the front view which showed the preheating apparatus of this embodiment. It is the bottom view which showed the preheating apparatus of this embodiment. It is the side view which showed the preheating apparatus of this embodiment. It is the side view which showed the state which attached the preheating apparatus of this embodiment to the metal mold | die.

Embodiments of the present invention will be described in detail with reference to the drawings as appropriate.
The preheating device of the present invention preheats a mold for casting a workpiece, and the shape of the mold to be preheated is not limited. In this embodiment, a preheating device for preheating a mold for casting a cylinder head of an engine will be described as an example.

As shown in FIG. 5, the mold 2 of this embodiment is divided into a lower mold 3, an intermediate mold 4, and an upper mold 5, and a cavity is formed by combining the molds 3, 4, and 5. The intermediate mold 4 is divided into four parts, front, rear, left and right, and combined on the upper surface 3 c of the lower mold 3. The upper die 5 is movable in the vertical direction with respect to the lower die 3 and the intermediate die 4.
In addition, the lower mold 3 and the intermediate mold 4 of the present embodiment correspond to the first mold in the claims, and the upper mold 5 corresponds to the second mold in the claims. Is.

As shown in FIG. 1, the lower mold 3 has six gates 3a. Specifically, four gates 3a are arranged side by side in the width direction on the front side in FIG. 1, and two gates 3a, 3a are arranged in parallel in the width direction on the back side in FIG.
In addition, the gate 3a of this embodiment is corresponded to the hole in a claim.

As shown in FIG. 5, each gate 3a penetrates in the vertical direction, and a lower surface 3b of the lower mold 3 is provided with a cylindrical intermediate stalk 7a communicating with each gate 3a. In addition, a cylindrical stalk 7b communicates with the lower end opening of the intermediate stalk 7a.
The intermediate stalk 7a and the stalk 7b in the present embodiment correspond to the stalk in the claims.

  When the cylinder head is cast using the mold 2, the molten metal is supplied from the stalk 7b to the gates 3a through the intermediate stalk 7a with the lower die 3, the intermediate die 4 and the upper die 5 closed. Molten metal is injected into the cavity.

As shown in FIG. 5, the preheating device 1 is disposed in the internal space 2 a of the mold 2 in order to preheat the mold 2, and protrudes from the substrate 10 and the lower surface 10 a of the substrate 10. Six first heaters 20 and two second heaters 30 and 30 projecting from the upper surface 10b of the substrate 10 are provided (see FIG. 3).
The internal space 2a of the mold 2 is a sealed space surrounded by the lower mold 3, the intermediate mold 4, and the upper mold 5, and includes a space serving as a cavity. In addition, although it is preferable that the internal space 2a is sealed tightly, in order to extend the wiring etc. of the preheating apparatus 1 outside, the small clearance gap may be formed.

The board | substrate 10 is a metal box wide in the left-right direction of FIG. 2, and is thinly formed in the height direction (up-down direction) (refer FIG. 1).
On the upper surface 10b of the substrate 10, the end of the wiring pipe 11 is joined in the vicinity of the right end of FIG.

The wiring pipe 11 is a metal pipe having a rectangular cross section (see FIG. 1), and communicates with the internal space of the substrate 10. The pipe 11 for wiring is bent from the upper surface 10b of the substrate 10 to the right side of FIG. 2, and further extends linearly toward the right side of FIG.
A power supply cable (not shown) connected to an external power source is inserted into the wiring pipe 11, and the tip of the power supply cable is inserted into the substrate 10.

  A heat shield 12 is erected on the upper surface 10 b of the substrate 10 in the vicinity of the left side of FIG. The heat shield 12 is a metal plate-like member, and both surfaces are directed in the left-right direction in FIG. The heat shield plate 12 shields heat generated by the second heater 30 described later from being transmitted to the wiring pipe 11.

As shown in FIG. 3, six first heaters 20 project from the lower surface 10 a of the substrate 10. Specifically, four first heaters 20 are juxtaposed in the left-right direction at the upper edge of FIG. 3, and two first heaters 20 are juxtaposed in the left-right direction at the lower edge of FIG. (See FIG. 4).
The positional relationship of each first heater 20 is set so that each first heater 20 is inserted through each gate 3a of the mold 2 (see FIG. 1).

  As shown in FIGS. 2 and 4, the first heater 20 includes a metal shaft member 21 erected vertically downward on the lower surface 10 a of the substrate 10. The shaft member 21 is a cylindrical member, and a fitting portion 22 having an enlarged diameter is formed at an intermediate portion in the axial direction (height direction).

  The fitting part 22 is a metal cylindrical member that is detachably fitted to the shaft member 21. A screw hole (not shown) passes through the outer peripheral wall portion of the fitting portion 22. The fitting portion 22 is fixed to the shaft member 21 by being brought into pressure contact with the surface. Therefore, the fitting part 22 can adjust the attachment position in the axial direction of the shaft member.

  As shown in FIG. 5, the fitting portion 22 is a portion that is fitted into the gate 3 a, and the upper portion is formed in a right circular column shape, and the lower portion is formed in a circular thrust trapezoidal shape reduced in a taper shape. Yes. Furthermore, the lower outer peripheral surface is formed following the inner peripheral surface of the gate 3a. Thus, by forming the lower part according to the inner peripheral surface of the gate 3a, when the fitting part 22 is inserted into the gate 3a, the fitting part 22 fits closely to the inner peripheral surface of the gate 3a. .

Further, when the fitting portion 22 is fitted in the gate 3a, the lower portion 21a of the shaft member 21 protrudes downward from the lower surface 3b of the lower mold 3 and is disposed in the intermediate stalk 7a. The protrusion amount of the shaft member 21 from the lower end is set.
Further, when the fitting portion 22 is fitted into the gate 3 a, the substrate 10 and the second heater 30 are disposed in the internal space 2 a of the mold 2.

  Inside the shaft member 21, a heating wire (not shown) is inserted in the axial direction. The heating wire is electrically connected to a power supply cable (not shown) in the substrate 10, and the heating wire generates heat by energizing the heating wire through the power supply cable. Then, the heat generated by the heating wire is transmitted to the shaft member 21 and the fitting portion 22, so that the first heater 20 generates heat.

As shown in FIG. 3, two second heaters 30 and 30 are juxtaposed in the left-right direction at the center of the upper surface 10b of the substrate 10 (see FIG. 4).
As shown in FIGS. 2 and 4, the second heater 30 includes a metal shaft member 31 erected vertically upward on the upper surface 10 b of the substrate 10.
The shaft member 31 is a cylindrical member, and as shown in FIG. 5, the fitting portion 22 of the first heater 20 is fitted into the gate 3a, the substrate 10 is disposed above the lower mold 3, and When the intermediate mold 4 and the upper mold 5 are assembled to the mold 3, they are arranged in the internal space 2 a between the lower mold 3 and the upper mold 5.

  Inside the shaft member 31, a heating wire (not shown) is inserted in the axial direction, and the heating wire is electrically connected within the substrate 10 to a power feeding cable (not shown). Then, similarly to the first heater 20, the second heater 30 generates heat by energizing the heating wire.

Next, a preheating method using the above-described preheating device 1 will be described.
First, as shown in FIG. 1, the preheating device 1 is disposed above the lower mold 3, and each first heater 20 is inserted into each gate 3a from the upper side of the lower mold 3 (the inner space 2a side of the mold 2). Then, the preheating device 1 is attached to the lower mold 3.
At this time, the preheating device 1 is positioned with respect to the lower mold 3 by fitting the fitting portion 22 of the first heater 20 into the gate 3a.

As shown in FIG. 5, the intermediate die 4 is assembled to the upper surface 3 c of the lower die 3 so as to surround the substrate 10, and the upper die 5 is attached to the upper surface 4 b of the intermediate die 4 via the spacer 8. The spacer 8 is a metal frame disposed along the inner peripheral edge of the intermediate die 4, and the space between the intermediate die 4 and the upper die 5 is sealed by the spacer 8. Further, the spacer 8 is formed with a concave groove 8a for inserting the wiring pipe 11 therethrough. The spacer 8 may be formed by arranging a plurality of block bodies on the upper surface 4 b of the intermediate mold 4.
Thus, by enlarging the internal space 2a of the mold 2 with the spacer 8, the substrate 10 and each second heater 30 can be arranged in the internal space 2a. In addition, the wiring pipe 11 extends to the outside from between the intermediate mold 4 and the upper mold 5 through the concave groove 8 a of the spacer 8.
And it supplies with electricity to the heating wire (not shown) of the 1st heater 20 and the 2nd heater 30 through an electric power feeding cable (not shown), and each heater 20 and 30 is heated.

  Heat is directly transmitted from the fitting portion 22 of the first heater 20 to the inner peripheral surface of the gate 3a, and heat radiated from the lower portion 21a of the shaft member 21 is transmitted to the intermediate stalk 7a and the stalk 7b. Further, the heat radiated from the shaft member 31 of the second heater 30 is transmitted to the intermediate mold 4 and the upper mold 5. In this way, the mold 2 is heated by the preheating device 1 and the mold 2 is in a preheated state.

  According to the preheating device 1 and the preheating method as described above, the heaters 20 and 30 are arranged in the internal space 2a of the mold 2 as shown in FIG. 2 can be heated uniformly. Further, since the second heater 30 is disposed in the internal space 2 a closed in a sealed state by the lower mold 3, the intermediate mold 4 and the upper mold 5, the heating efficiency of the mold 2 can be increased.

Moreover, the contact area of the fitting part 22 and the lower mold | type 3 becomes large because the outer peripheral surface of the fitting part 22 of the 1st heater 20 is formed following the shape of the inner peripheral surface of the gate 3a. In addition, since the heat conduction efficiency from the first heater 20 to the lower mold 3 is high, the mold 2 can be effectively heated.
Moreover, since the gate 3a is blocked by the fitting portion 22, the heat of the internal space 2a is not easily radiated to the outside of the mold 2 through the gate 3a, so that the heating efficiency of the mold 2 can be increased.

  Further, since the shaft member 21 of the first heater 20 protrudes into the intermediate stalk 7a and the intermediate stalk 7a and stalk 7b can be heated by the first heater 20, a mechanism for preheating the mold 2 is used. Can be simplified.

  In addition, as compared with the conventional case where a heat source such as a burner is disposed in the external space of the mold 2, the heat of each heater 20, 30 is not easily dissipated to the external space of the mold 2. The influence can be reduced.

  Moreover, since the electrothermal heaters 20 and 30 are used, it is easier to manage the heating state compared to a configuration in which a burner or the like is burned. Therefore, since the mold 2 can be preheated even during a time when it is difficult to ensure a sufficient monitoring system, such as a work break, work efficiency can be improved.

  Further, as shown in FIG. 2, a heat shield plate 12 is erected between the second heater 30 and the wiring pipe 11, and the heat of the second heater 30 is shielded by the heat shield plate 12. Therefore, it is difficult to be transmitted to the wiring pipe 11. Therefore, the influence of heat on the power supply cable (not shown) in the wiring pipe 11 can be prevented.

Moreover, when attaching the preheating apparatus 1 to the lower mold | type 3, the preheating apparatus 1 is correctly and simply attached with respect to the metal mold | die 2 by fitting the fitting part 22 of each 1st heater 20 in each gate 3a. Can be positioned.
Further, by using the gate 3a formed in the mold 2, the preheating device 1 can be attached to the mold 2 without processing the existing mold 2.

  Further, the spacer 8 is interposed between the intermediate mold 4 and the upper mold 5 to enlarge the internal space 2a of the mold 2, so that the preheating device 1 can be easily arranged in the internal space 2a of the mold 2. . Further, the wiring pipe 11 can be extended to the outside from between the intermediate mold 4 and the upper mold 5.

The embodiment of the present invention has been described above, but the present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the spirit of the present invention.
For example, in the preheating device 1 of this embodiment, as shown in FIG. 1, six first heaters 20 are provided on the lower surface 10a of the substrate 10, and two second heaters 30 and 30 are provided on the upper surface 10b. However, the number and arrangement of the heaters 20 and 30 can be set in correspondence with the shape of the mold 2 to be preheated.

  Further, in the present embodiment, the first heater 20 is provided on the lower surface 10a of the substrate 10 and the second heater 30 is provided on the upper surface 10b. May be used as the second heater. That is, one member may be divided into a first heater and a second heater.

  Further, the heating efficiency of the mold 2 can be improved by bringing the second heater 30 shown in FIG. 5 into contact with the upper mold 5 or providing a heating wire in the substrate 10 to generate heat. it can.

  Further, in the preheating device 1 of the present embodiment, the shaft member 21 of the first heater 20 protrudes into the intermediate stalk 7a, but the shaft member 21 may not protrude into the intermediate stalk 7a.

Moreover, the hole part in which the shaft member 21 shown in FIG. 1 is inserted does not need to penetrate the lower mold 3.

In the present embodiment, the fitting portion 22 of the first heater 20 is detachable from the shaft member 21, but the fitting portion 22 is formed by expanding a part of the shaft member 21. Alternatively, the shaft member 21 and the fitting portion 22 may be integrated.
Furthermore, in this embodiment, although the fitting part 22 is formed in the shaft member 21 of the first heater 20, the shaft member 21 is loosely fitted in the gate 3a without forming the fitting part 22. You may comprise.

1 Preheating device 2 Mold 3 Lower mold (first mold)
3a gate (hole)
4 Intermediate mold 5 Upper mold (second mold)
7a Intermediate Stoke (Stoke)
7b Stoke 8 Spacer 10 Substrate 11 Pipe for wiring 12 Heat shield plate 20 First heater 21 Shaft member 22 Fitting portion 30 Second heater 31 Shaft member

Claims (7)

A preheating device for heating a mold using an electric heater,
A first heater inserted from the inner space side of the mold into the hole formed in the mold;
A second heater disposed in the internal space of the mold ,
The mold preheating apparatus , wherein the hole is a gate formed in the mold. The mold is divided into a first mold and a second mold,
2. The mold preheating apparatus according to claim 1, wherein the second heater is disposed in the internal space closed by the first mold and the second mold. 3. The first heater has a fitting portion that is fitted in the hole portion,
3. The mold preheating device according to claim 1, wherein an outer peripheral surface of the fitting portion is formed to follow an inner peripheral surface of the hole portion. The outer surface of the mold is provided with a stalk communicating with the hole,
Wherein the first heater, the mold preheating device according to any one of claims 1 to 3, characterized in that protrudes into said stalk. 5. The mold according to claim 1, wherein the second heater is disposed in an inner space of the mold in a state of being separated from an inner surface of the mold. Preheating equipment. A feeding cable is electrically connected to the first heater and the second heater,
The feeding cable is inserted into a wiring pipe disposed in the internal space of the mold,
6. A heat shield plate for shielding heat generated by the second heater is provided between the second heater and the wiring pipe. The mold preheating apparatus according to any one of the above. A mold preheating method using the preheating device according to claim 2,
The hole is formed in the first mold,
Inserting the first heater into the hole from the inner space side of the mold, and attaching the preheating device to the first mold;
The second mold is attached to the first mold via a spacer, and the second heater is disposed in the internal space closed by the first mold and the second mold. Stages,
And a step of generating heat in the first heater and the second heater.

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