JPH0528006Y2 - - Google Patents

Description

[Detailed explanation of the invention] (a) Industrial application field This invention relates to injection molds.

(b) Conventional technology Optical fiber connector parts or bonding capillaries for LSI manufacturing equipment mainly use
Microscopic holes of 300 μm are provided. This hole is required to have extremely high concentricity with respect to the outer diameter of the component.

(c) Problems to be solved by the invention When attempting to manufacture ceramic products with such pores by injection molding, the diameter D of the core pin is extremely small, on the order of μm, and the length of the core pin is extremely small. L is several tens of mm, so-called L/D
It becomes necessary to machine large holes. Since such a core pin having a small diameter and a large L/D has a high possibility of pin breakage, it does not have a long lifespan, and it is necessary to frequently replace the core pin.
When the core pin is set in the movable core block, in order to reduce the influence of gravity, the position of the tip of the core pin, which is vertically oriented downward, changes each time the core pin is changed. It was necessary to adjust the concentricity with the inner diameter of the cavity, but in practice the extremely thin tip of the pin sometimes broke, making it extremely difficult to handle. The present invention aims to solve such problems.

(d) Means for solving the problem The present invention provides a cylindrical eccentric core whose inner diameter is eccentric to the outer diameter so as to surround the core pin in the space formed by both core blocks. The above problem is solved by making the inner diameter part a cavity and adjusting the concentricity by rotating the eccentric core so that it matches the center to which the core pin is oriented when no force is applied to it. That is, in the present invention, a core pin is provided in a space formed by a fixed side mold, a movable side mold, and a core block embedded in both molds, and the tip side of this core pin is fitted. and a pin receiver having a hole, and a cylindrical eccentric core is provided in a space between the pin receiver and the movable core block so as to surround the core pin. It is a mold for molding.

It is desirable to prepare several types of eccentric cores with different degrees of eccentricity. Further, in order to prevent the eccentric core, which has been adjusted for concentricity, from shifting, it is preferable to provide a screw for fastening the eccentric core to the stationary core block. Depending on design conditions, the mold and core block may be integrated.

(e) Effect This adjustment work is required when a new core pin is installed. After pulling out each core block from both molds, with the eccentric core, new core pin and pin receiver set in the movable core block, use a tool microscope etc. to insert the core pin into the core block from one end of the fixed core block. Measure the concentricity of the inner diameter of the pin receiver, and make adjustments by rotating the eccentric core until the desired concentricity is obtained. It is assumed that the concentricity between the inner diameter of the eccentric core and the inner diameter of the pin receiver is sufficiently guaranteed. If the concentricity between the inner diameter of the eccentric core and the core pin is too large and the desired concentricity cannot be obtained with the eccentric core being used, replace it with an eccentric core that has a different eccentricity. and repeat the same adjustment work. When the desired concentricity is obtained, tighten the eccentric core fastening screw provided on the fixed side core block toward the eccentric core, fix the eccentric core so that it does not rotate, and embed both core blocks in both molds. to finish the work. When injection molding is performed after this operation, the inner diameter portion of the eccentric core becomes a cavity, and the concentricity of the core pin with respect to the cavity can be maintained with high precision, so that a product with good concentricity can be obtained.

(F) Embodiments Hereinafter, embodiments of the present invention will be described in detail based on the drawings. In FIGS. 1 and 2, a movable mold 2 is provided opposite to a fixed mold 1. Also,
A fixed side core block 3 and a movable side core block 4 are embedded in the fixed side mold 1 and the movable side mold 2, respectively. The stationary core block 3 is provided with a space 5 having an inner diameter larger than the outer diameter of the product. A cylindrical eccentric core 6 whose inner diameter part is eccentric by an eccentric amount s relative to the outer diameter part is fitted into this space 5, and the inner diameter part of the eccentric core 6 forms a cavity 6a. One end of the core pin 7 screwed into the movable core block 4 extends into the cavity 6a. The movable mold 2 is provided with a gate 8 for feeding injection material into the cavity 6a via the movable core block 4. One end of the eccentric core 6 is in contact with the movable core block 4, and the other end of the eccentric core 6 is in contact with the stationary mold 1. The collar 9a of the pin receiver 9 engages with the stepped portion 6b of the eccentric core 6. The tip of the core pin 7 is fitted into the hole 9b of the pin receiver 9. A plurality of eccentric core fastening screws 10 are provided approximately in the middle of the portion of the stationary core block 3 that accommodates the eccentric core 6 at equal intervals on the circumference. The eccentric core fastening screw 10 can fix the eccentric core 6 to the stationary core block 3. Note that the core block fastening screws 11 are provided to attach both core blocks 3 and 4 to both molds 1 and 2.
Guide pin 1 provided on fixed side core block 3
2 is fitted into a guide pin hole 13 provided in the movable core block 4 to connect both core blocks 3, 4.
It has come to regulate the relative position of Similarly, the mold guide pin 14 provided in the movable mold 2 is connected to the mold guide pin hole 15 provided in the fixed mold 1.
The molds 1 and 2 are fitted together to regulate the relative position of both molds 1 and 2.

In this embodiment, the space 5 is provided in the fixed core block 3, but it may be provided in the movable core block 4 depending on the design conditions.

Next, the operation of this embodiment will be explained.

Screw the new core pin 7 into the movable core block 3, fit the eccentric core 6 and pin receiver 9 into the fixed core block 3, fit the guide pin 12 into the guide pin hole 13, and then screw both core blocks 3,
Integrate 4. The eccentricity of the hole 9b of the pin receiver 9 with respect to the core pin 7 is measured using a tool microscope (not shown) or the like. until it is within the desired concentricity.
Rotate the eccentric core 6. If the degree of eccentricity is too large and cannot be fully adjusted, other eccentric cores 6, 6, . . . having different degrees of eccentricity are replaced one after another and the same adjustment is performed. Once the concentricity has been adjusted to the desired level, the eccentric core fastening screw 10 is tightened to fix the eccentric core 6 to the stationary core block 3. Both core blocks 3 and 4 are fitted into both molds 1 and 2, and integrated with core block fastening screws 11 and 11, respectively.

The product is manufactured by injecting a ceramic raw material (not shown) through the gate 8 between the cavity 6a and the outer diameter of the core pin 7, but since the process is the same as the conventional one, details will be omitted. Omitted.

(g) Effects of the invention As explained above, according to the invention, when injecting ceramic raw materials, the concentricity between the core pin and the cavity can be adjusted relatively easily.
A product having micropores with a large L/D can be molded with high precision.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway sectional view of the injection mold of the present invention, and FIG. 2 is an enlarged view taken in the direction of arrow A in FIG. 1...Fixed side mold, 2...Movable side mold, 3...
Fixed side core block, 4... Movable side core block, 5... Space, 6... Eccentric core, 6a... Cavity, 6b... Step portion, 7... Core pin, 8...
Gate, 9...Pin holder, 9a...Brim, 9b...
... Hole, 10 ... Screw for fastening eccentric core, 11 ... Screw for fastening core block, 12 ... Guide pin, 1
3... Guide pin hole, 14... Mold guide pin,
15... Mold guide pin hole, s... Eccentricity.

Claims (1)

[Scope of utility model registration request] A core pin provided in a space formed by a fixed side mold, a movable side mold, and a core block embedded in both molds, and a pin receiver having a hole into which the tip end of the core pin is fitted. An injection mold comprising: a cylindrical eccentric core provided in a space between the pin receiver and the movable core block so as to surround the core pin.