JP2631687B2 - Mold for glass optical element - Google Patents

Description

The present invention relates to a molding die used for press molding glass optical elements such as lenses.

[Conventional technology]

Conventionally, an upper mold, a lower mold, and a frame mold having a through-hole in which at least the top portions of the upper mold and the lower mold are provided. The glass mold is moved from a position away from the upper surface of the through hole of the mold to a position where the glass optical element is pressed by the tip of the lower mold in the through hole of the frame mold. 2. Description of the Related Art There is known a mold that is moved from a position where the optical element is formed to a position where the molded optical element protrudes from the upper surface of the through hole of the frame. Injection of a glass material into such a mold was performed by raising the upper mold until the glass material could be introduced into the frame mold, and dropping the glass material onto the lower mold upper surface in the frame mold through hole. .

[Problems to be solved by the invention]

In the conventional molding die as described above, since the glass material comes into contact with the tip surface of the lower mold from the time of injection, the contact time between the glass material and the tip surface of the lower mold becomes longer, or the tip surface of the lower mold deteriorates, In the case where the glass optical element comes to be fused to the lower mold front end face, a portion which comes into contact with the lower mold front end face of the glass optical element is formed, or the glass material is heated after being charged, the glass material is further heated. There was a problem that uniform heating was difficult.

The present invention has been made for the purpose of solving the above-mentioned problems, and it is possible to perform the charging of the glass material so as not to make contact with the lower mold tip surface, and to reduce the contact time between the glass cloth and the lower mold tip surface. An object of the present invention is to provide a molding die that can be shortened and can easily be heated uniformly even when the glass cloth is heated after being charged.

[Means for solving the problem]

The present invention includes an upper mold, a lower mold, and a frame mold having a through-hole in which at least the tip portions of the upper mold and the lower mold fit together,
The upper mold presses the glass optical element between the frame mold and the tip of the lower mold in the frame-shaped through-hole from a position away from the top of the frame-type through-hole until at least the tip end of the glass mold can be charged with the glass material. The lower mold is moved to the molding position, and the lower mold has at least its tip end face with respect to the frame mold, and the optical element molded from the position where the glass optical element is press-molded with the tip end face of the upper mold. In the glass optical element molding die that is moved to the position where it protrudes from the upper surface, the cross section of the part that fits with the upper die of the through hole of the frame mold is larger than the cross section of the part where the lower die fits, and the cross section changes The glass material put into the through-hole is held by the cross-section changing portion, and the lower end surface of the frame is formed inside the outer wall member having the outer wall portion and the bottom plate portion. Position so as to face the top surface of the bottom plate Then, the outer frame member is brought into a position where the upper die interferes with the upper die and the top surface of the upper die is put into the through hole of the frame die and held at a position where the upper die does not come into contact with the glass material held by the cross-sectional deformation portion. A first wedge member displaceable between a position where the upper die can be moved without interference, and a first deformable portion which is inserted into a through hole between a lower end surface of the frame die and an upper surface of the bottom plate portion and is inserted into the through hole; Between the position where the glass material held in the position where the frame material is lifted with respect to the lower mold at a position where the glass material is not in contact with the front end surface of the lower mold and the position where the lower end surface of the frame mold and the upper surface of the bottom plate portion are separated from each other. A second wedge member that can be displaced is attached, and the above object is achieved by this configuration.

(Operation)

The molding die of the present invention is configured such that the cross section of the portion that mates with the upper die of the frame die through hole is larger than the cross section of the portion that mates with the lower die, thereby separating the upper die from the through hole of the frame die. When the glass material is charged into the through-hole, the glass material is held at the cross-sectionally changed portion of the through-hole and can be prevented from contacting the tip surface of the lower mold. Even if the first wedge member attached to the frame member is displaced to a position where the first wedge member interferes with the upper die, and the upper die is heated to a position where it can be stopped by the first wedge member, even if the upper die is made of glass, Since the lower mold does not contact the glass material without contacting the material, the glass material can be uniformly heated.
The press forming of the glass material heated to a temperature equal to or higher than the glass transition point is performed by detaching the second wedge member attached to the outer frame member from the lower end surface of the frame die, and by moving the lower end surface of the frame die to the outer frame member bottom plate portion. This is performed by lowering the upper die until it comes into contact with the upper surface, displacing the second wedge member attached to the outer frame member to a position not interfering with the upper die, and lowering the upper die into a predetermined position in the through hole of the frame die. Can be. Therefore, according to the mold of the present invention, the lower mold tip surface is deteriorated due to the longer contact time between the glass material and the lower mold tip face, and the glass optical element is fused to the lower mold tip face or contacts the lower mold tip face. In this case, uniform heating can be easily achieved even when heating after charging the glass material.

〔Example〕

 Hereinafter, the present invention will be described with reference to illustrated examples.

1 to 4 are cross-sectional views showing a glass optical element press forming process using the mold of the present invention. FIG. 1 shows a state in which a glass material is charged, and FIG. 2 shows a state before the start of press forming. FIG. 3 shows a state where the pressing operation is completed, and FIG. 4 shows a state immediately before picking up the glass optical element. 5 is a partial plan view in which the left half shows the wedge member on the upper surface of the outer frame member peripheral wall portion, and the right half shows the wedge member on the upper surface side of the outer frame member peripheral bottom plate portion. FIG. 6 shows the state shown in FIG. FIG. 7 is a perspective view showing an example of means for changing to the state shown in FIG. 2, and FIG. 7 is a partial side view showing a state in which a wedge member on the upper surface side of the outer frame member bottom plate lifts the frame die.

In the figure, 1 is the upper die, 2 is the tip surface of the upper die, 3 is the lower die,
Reference numeral 4 denotes a lower die tip surface, 5 denotes a frame type, 6 denotes a frame type through hole, 7 denotes a frame type through hole upper surface, 8 denotes a frame type through hole cross section changing portion, 9 denotes an outer frame member, and 10 denotes an outer frame member peripheral wall portion. , 11 is an outer frame member bottom plate portion, 12
Is a wedge member (first wedge member) attached to the upper surface of the peripheral wall portion of the outer frame member, 13 is a wedge member (second wedge member) attached to the upper surface of the bottom plate portion of the outer frame member, and 14 is a bottom plate portion penetrating portion It is.

In the state shown in FIG. 1, the upper mold 1 is raised to the position shown in FIG. 4 by a known upper mold lifting / lowering means using a screw, a plunger, or the like (not shown). After the glass material G is put into the through hole 6 of the frame die 5 as shown in the figure, the upper die is lowered until the upper die 1 hits the wedge member 12 brought to a position where it interferes with the upper die 1 as shown in the figure. It is in a state where it is. This state occurs when the glass material G is heated to a molding temperature or higher in advance, or when the glass material G is heated by the built-in frame heater or the upper and lower mold built-in heaters after being charged.
It is in a state where heat is not lost. In this state, since the frame die 5 is lifted from the outer frame member bottom plate portion 11 by the wedge member 13 as shown in the figure, the input glass material G is stopped by the cross-section changing portion 8 of the frame die through hole 6. The upper die 1 does not come into contact with the front end surface of the lower die 3, and the upper die 1 is also stopped by the wedge member 12 at a position where the front end surface 2 does not come into contact with the glass material G.

In the state shown in FIG. 2, the temperature of the glass material G in the state shown in FIG.
13 is in a state where it is removed from the lower surface of the frame die 5. The wedge member 13
For example, the spring is urged counterclockwise by a spring so as to take a solid line position shown in the right half of FIG. 5, and enters the lower side of the frame mold 5 at the solid line position as shown in FIG. 5
And the guide mold member according to the present invention shown in FIG.
When being guided to 15 and fed or fed from the heating station to the press station, the portion of the wedge member 13 protruding outside from the outer frame member bottom plate portion 11 is pressed by the side wall cam surface 15a of the guide member 15 and the spring is pressed. It turns clockwise against the bias to take the position shown by the two-dot chain line in FIG. As a result, the lower end surface of the frame die 5 has the outer frame member bottom plate portion 11.
The glass material G comes on the tip end surface 4 of the lower mold 3 in the illustrated example. When the mold is placed in a heating furnace for heating the glass material G, the heat resistance of the spring becomes a problem.
The above-mentioned displacement may be performed by means such as a groove cam which does not require a spring. In the example shown in FIG. 6, the above-described upper mold lifting / lowering means in the charging or heating station moves the upper mold 1 to a position where the glass material G can be charged.
And when the glass material G is charged, the upper mold 1
The upper die 1 need not be able to be lowered until the glass material G is pressed.

The state shown in FIG. 3 is changed from the state shown in FIG. 2, that is, the state in which the wedge member 12 is engaged with the upper mold 1 from the solid line position in the left half of FIG. The upper mold 1 is rotated by the upper mold elevating means by rotating the upper mold 1 to the deviated two-dot chain line position, and the glass material is separated by the distal end face 4 of the lower mold 3 and the end face of the cross section changing portion 8 of the frame type through hole 6. G is pressed down to form an optical element L by pressing. In this case, the wedge member
The displacement of 12 is performed by means similar to the means for displacing wedge member 13. The removal of the wedge member 12 from the upper mold 1 may be performed simultaneously with or before or after the removal of the wedge member 13 from the frame mold 5. Of course, the charging or heating and press forming of the glass material G may be performed at the same place, and the drive of the wedge members 12 and 13 may be performed by a suitable automatic or manual drive means provided at that place. .

In the state shown in FIG. 4, the locking member 16 provided in the press station in the state shown in FIG. 3 is caused to protrude into the engaging groove 5a provided in the frame mold 5 through the through hole 10a provided in the outer frame member peripheral wall portion 10. After that, the upper die 1 is raised to the position shown in the figure by the upper die raising means, and then the lower die 3 is pushed up by a push-up member 17 such as a plunger through the penetrating portion 14 of the outer frame member bottom plate portion 11 so that the optical element L is framed. This is a state where it is projected above the upper surface 7 of the through hole. In this state, the optical element L can be easily removed from the mold of the present invention.

When the optical element L is removed from the mold, the locking member 16 is retracted to disengage at least from the engagement with the frame mold 5, and then the lower mold 3 is raised from the state shown in FIG. The frame mold 5 is raised together with the mold 3.
A wedge member 13 is inserted into a gap between the frame die 5 and the upper surface of the outer frame member bottom plate portion 11 generated thereby. When the wedge member 13 is biased by a spring, it automatically enters. So the thrust member
17 is lowered, the lower mold 3 is lowered on the upper surface of the outer frame member bottom plate portion 11, and the frame mold 5 is lowered on the wedge member 13. Then, the glass material G is dropped into the frame mold through hole 6, and then the upper mold 1 is removed. By lowering by the upper die lifting means and lowering it on the wedge member 12 which has been returned to the position where it interferes with the upper die 1, the state returns to the state shown in FIG.

The locking member 16 or the push-up member 17 shown in FIG. 3 or FIG. 4 can be used as the side wall of the guide path member 15 for returning the mold of the present invention from the press station to the loading station again through the optical element take-out station and the return guide path. It may be a projecting portion on the bottom surface. In this case, the wedge members 12 and 13 can be completely displaced by the groove cam. When the push-up member 17 is a protruding portion of the bottom surface of the guide path member 15,
The through portion 14 of the outer frame member bottom plate portion 11 is not a through hole, but a through groove dividing the bottom plate portion 11 into two. And
The split bottom plate portion 11 is integrally connected by the peripheral wall portion 10. When the locking member 16 and the push-up member 17 are cams provided on the guide path member 15, it goes without saying that a means for driving the engaging member 16 and the push-up member 17 becomes unnecessary.

〔The invention's effect〕

By using the molding die of the present invention, the upper and lower dies can be brought into contact with the heated glass material for the first time when the optical element is press-molded. Prevents the elements from fusing and preventing the glass optical element from sticking to the pressing surface.Even when the glass material is put into a mold and heated, it can be easily and uniformly heated. The effect that it can be obtained is obtained.

[Brief description of the drawings]

FIG. 1 to FIG. 4 are cross-sectional views showing specific states in a glass optical element press forming step of the mold of the present invention,
In FIG. 5, the left half shows the wedge member on the upper surface of the outer frame member peripheral wall portion,
The right half is a partial plan view showing the wedge member on the upper surface side of the outer frame member bottom plate portion, FIG. 6 is a perspective view showing an example of means for changing to the state of FIG. 1, and FIG. FIG. 6 is a partial side view showing a state where the wedge member of FIG. 1 ... upper die, 3 ... lower die, 5 ... frame type, 6 ... frame type through hole, 8 ... frame type through hole cross-section changing part, 9 ... outer frame member, 10 ... outer frame member Peripheral wall portion, 11 ... Outer frame member bottom plate portion, 12 ... Wedge member (first wedge member) 13 ... Wedge member (second wedge member)

Claims (1)

(57) [Claims] An upper mold, a lower mold, and a frame mold having a through-hole in which at least the tip portions of the upper mold and the lower mold fit together,
The upper mold presses the glass optical element between the frame mold and the tip of the lower mold in the frame-shaped through-hole from a position away from the top of the frame-type through-hole until at least the tip end of the glass mold can be charged with the glass material. The lower mold is moved to the molding position, and the lower mold has at least its tip end face with respect to the frame mold, and the optical element molded from the position where the glass optical element is press-molded with the tip end face of the upper mold. In the glass optical element molding die that is moved to the position where it protrudes from the upper surface, the cross section of the part that fits with the upper die of the through hole of the frame mold is larger than the cross section of the part where the lower die fits, and the cross section changes The glass material put into the through-hole is held by the cross-section changing portion, and the lower end surface of the frame is formed inside the outer wall member having the outer wall portion and the bottom plate portion. Position so as to face the top surface of the bottom plate Then, the outer frame member is brought into a position where the upper die interferes with the upper die and the top surface of the upper die is put into the through hole of the frame die and held at a position where the upper die does not come into contact with the glass material held by the cross-sectional deformation portion. A first wedge member displaceable between a position where the upper die can be moved without interference, and a first deformable portion which is inserted into a through hole between a lower end surface of the frame die and an upper surface of the bottom plate portion and is inserted into the through hole; Between the position where the glass material held in the position where the frame material is lifted with respect to the lower mold at a position where the glass material is not in contact with the front end surface of the lower mold and the position where the lower end surface of the frame mold and the upper surface of the bottom plate portion are separated from each other. A molding die for a glass optical element, comprising a displaceable second wedge member.