초록 ▼

The molding device comprises a lower mold unit and an upper mold unit. When the upper mold unit approaches the lower mold unit, a molding cavity is defined between the lower and upper mold units. The lower mold unit has a storing chamber that is communicated with the molding cavity. The lower mold u

The molding device comprises a lower mold unit and an upper mold unit. When the upper mold unit approaches the lower mold unit, a molding cavity is defined between the lower and upper mold units. The lower mold unit has a storing chamber that is communicated with the molding cavity. The lower mold unit comprises a pressure-decreasing mechanism and a pushing mechanism. A molten material is stored in the storing chamber. When the molding cavity is formed between the lower mold unit and the upper mold unit, the pressure-decreasing mechanism decreases pressure in the molding cavity. Afterwards, in sync with the operation that the upper mold unit pushing down a lower mold-holding member of the lower mold unit, an injection rod of the pushing mechanism pushes out the molten material in the storing chamber to the molding cavity. As a result, the efficiency of the molding operation is improved.

대표청구항 ▼

What is claimed is: 1. A molding device comprising: a first mold unit; a second mold unit arranged to face the first mold unit, wherein the first mold unit and the second mold unit relatively approach and are separated from each other, and wherein, when the first mold unit and the second mold unit

What is claimed is: 1. A molding device comprising: a first mold unit; a second mold unit arranged to face the first mold unit, wherein the first mold unit and the second mold unit relatively approach and are separated from each other, and wherein, when the first mold unit and the second mold unit approach each other to be closed, a molding cavity is defined between the first mold unit and the second mold unit; a storing chamber arranged in at least one of the first mold unit and the second mold unit, wherein the storing chamber is communicated with the molding cavity and stores molten material; a pushing mechanism, wherein the pushing mechanism pushes out the molten material in the storing chamber to the molding cavity when the molding cavity is defined between the first mold unit and the second mold unit, wherein the pushing mechanism includes a pushing rod that is inserted to the storing chamber, the pushing rod having an end surface that forms a bottom of the storing chamber, wherein one of the first and second mold units has an insertion hole that is communicated with the storing chamber and receives the pushing rod, wherein a predetermined second space is defined between an outer circumferential surface of the pushing rod and an inner circumferential surface of the insertion hole; a first pressure-decreasing mechanism for decreasing pressure in the molding cavity prior to pushing out the molten material in the storing chamber to molding cavity; and a second pressure-decreasing mechanism for decreasing pressure on a side of the molten material that is opposite to the molding cavity substantially at the same time that the pressure in the molding cavity is decreased, wherein the second pressure-decreasing mechanism includes a second seal member and a second pressure-decreasing passage, wherein the second seal member seals a space between the outer circumferential surface of the rushing rod and the inner circumferential surface of the insertion hole, and wherein the second pressure-decreasing passage is communicated with a part of the second space between the second seal member and the storing chamber. 2. The molding device according to claim 1, wherein each of the first mold unit and the second mold unit has a facing surface, the facing surfaces facing each other, and the pressure-decreasing mechanism includes a first seal member arranged between the facing surfaces and a first pressure-decreasing passage that is open in at lease one of the facing surfaces, and when the facing surfaces approach each other such that a predetermined first space is defined between the facing surfaces, the first seal member seals a space between the facing surfaces to surround the molding cavity and a part of the first space, and the first pressure-decreasing passage is communicated with the molding cavity via the part of the first space that is surrounded by the first seal member. 3. The molding device according to claim 1 further comprising a cooling mechanism that cools down the second seal member. 4. The molding device according to claim 1, wherein the first mold unit is a lower mold unit and the second mold unit is an upper mold unit that is arranged above the lower mold unit, and wherein the storing chamber and the pushing mechanism are arranged in the lower mold unit. 5. The molding device according to claim 4, wherein the lower mold unit includes a movable member that defines a part of the molding cavity and has the storing chamber, and wherein the pushing rod pushes out the molten material in the storing chamber to the molding cavity as the movable member moves together with the upper mold unit with respect to the pushing rod. 6. The molding device according to claim 4, wherein the lower mold unit includes a horizontal support plate, a lower mold-holding member that is supported on the horizontal support plate to reciprocate in a vertical direction, a lower mold that is held by the lower mold-holding member, and a lift-maintaining mechanism that lifts the lower mold-holding member and maintains the lower mold-holding member at a predetermined height position from the horizontal support plate, wherein the pushing rod that is arranged upward from the horizontal support plate, and wherein the pushing rod pushes out the molten material in the storing chamber to the molding cavity as the lower mold-holding member is pushed down toward the horizontal support plate by the upper mold unit. 7. The molding device according to claim 4, wherein the lower mold unit includes a position adjustment mechanism that adjusts an axial position of the pushing rod according to the amount of the molten material in the storing chamber. 8. The molding device according to claim 4, wherein the first and second mold units relatively move in a vertical direction and a horizontal direction. 9. The molding device according to claim 4, wherein the lower mold unit has a tilt mechanism that tilts the storing chamber. 10. A molding device comprising: a lower mold unit; an upper mold unit arranged above the lower mold unit to be capable of approaching and separating from the lower mold unit, wherein a molding cavity is defined between the lower mold unit and the upper mold unit when the upper mold unit approaches the lower mold unit to be closed; a storing chamber arranged in the lower mold unit, wherein the storing chamber is communicated with the molding cavity and stores molten material; a first pressure-decreasing mechanism for decreasing pressure in the molding cavity when the molding cavity is defined between the lower mold unit and the upper mold unit; a second pressure-decreasing mechanism for decreasing pressure on a side of the molten material that is opposite to the molding cavity substantially at the same time that the pressure in the molding cavity is decreased; and a pushing mechanism arranged in the lower mold unit for pushing out the molten material in the storing chamber to the molding cavity when the pressure in the molding cavity is decreased, wherein the pushing mechanism includes a pushing rod that is inserted to the storing chamber, the pushing rod having an end surface that forms a bottom of the storing chamber, wherein the lower mold unit has an insertion hole that is communicated with the storing chamber and receives the pushing rod, wherein a predetermined second space is defined between an outer circumferential surface of the pushing rod and an inner circumferential surface of the insertion hole, wherein the second pressure-decreasing mechanism includes a second seal member and a second pressure-decreasing passage, wherein the second seal member seals a space between the outer circumferential surface of the pushing rod and the inner circumferential surface of the insertion hole, and wherein the second pressure-decreasing passage is communicated with a part of the second space between the second seal member and the storing chamber. 11. The molding device according to claim 10, wherein each of the lower mold unit and the upper mold unit has a facing surface, the facing surface facing each other, and the first pressure-decreasing mechanism includes a first seal member arranged between the facing surfaces and a first pressure-decreasing passage that is open in one of the facing surfaces, and when the facing surfaces approach each other such that a predetermined first space is defined between the facing surfaces, the first seal member seals a space between the facing surfaces to surround the molding cavity and a part of the first space, and the fist pressure-decreasing passage is communicated with the molding cavity via the part of the first space that is surrounded by the first seal member. 12. The molding device according to claim 10 further comprising a cooling mechanism that cools down the second seal member. 13. A molding device comprising: a lower mold unit, wherein the lower mold unit includes a horizontal support plate, a lower mold-holding member that is supported on the horizontal support plate to reciprocate in a vertical direction, a lower mold that is held by the lower mold-holding member, and a lift-maintaining mechanism that lifts the lower mold-holding member and maintains the lower mold-holding member at a predetermined height position from the horizontal support plate; an upper mold unit arranged above the lower mold unit, wherein the lower mold unit and the upper mold unit relatively approach and are separated from each other, and wherein, when the lower mold unit and the upper mold unit approach each other to be closed, a molding cavity is defined between the lower mold unit and the upper mold unit; a storing chamber arranged in the lower mold unit, wherein the storing chamber is communicated with the molding cavity and stores molten material; and a pushing mechanism arranged in the lower mold unit for pushing out the molten material in the storing chamber to the molding cavity when the molding cavity is defined between the lower mold unit and the upper mold unit, wherein the pushing mechanism includes a pushing rod that is arranged upward from the horizontal support plate, the pushing rod having an end surface that forms a bottom of the storing chamber, and wherein the pushing rod pushes out the molten material in the storing chamber to the molding cavity as the lower mold-holding member is pushed down toward the horizontal support plate by the upper mold unit. 14. A molding device comprising: a lower mold unit; an upper mold unit arranged above the lower mold unit, wherein the lower mold unit and the upper mold unit relatively approach and are separated from each other, and wherein, when the lower mold unit and the upper mold unit approach each other to be closed, a molding cavity is defined between the lower mold unit and the upper mold unit; a storing chamber arranged in the lower mold unit, wherein the storing chamber is communicated with the molding cavity and stores molten material; a pushing mechanism arranged in the lower mold unit for pushing out the molten material in the storing chamber to the molding cavity when the molding cavity is defined between the lower mold unit and the upper mold unit; and a position adjustment mechanism arranged in the lower mold unit for adjusting an axial position of the pushing mechanism according to the amount of the molten material in the storing chamber.