JPH09141699A - Injection molding die - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable an injection molding die to be easily repaired and replaced by fixing detachably at least either of a core block or a cavity block to a member on the side of a movable side injection molding die or a member on the side of a fixed side injection molding die, from a parting face side. SOLUTION: When removing a cavity block 46 from a fixed side template 45, a mounting screw 49 for fixing the cavity block 46 to the fixed side template 45 is removed from a front parting face 55 side. In addition, plural mounting screws 69 for fixing a core block unit 58 to an inner cradle 62 are loosened and removed from the parting face 55. Thus the clamping force of the core block unit 58 is released and consequently the unit 58 is set free, so that it can be pulled out along a positioning pin 71. In this state, the core block unit is easily detached from the inner cradle 62.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method in which a molding material which has been heated and melted into a plasticized state is filled in a previously closed mold cavity by applying pressure and then cooled (in the case of a thermoplastic resin) or heated. (In the case of thermosetting resin) Regarding an injection molding die for solidifying to obtain a molded product, particularly, only a core block or a cavity block with a movable side mold or a fixed side mold attached to an injection molding machine The present invention relates to an injection molding die that can be removed and replaced.

[0002]

2. Description of the Related Art In general, a casing such as a compact cassette (audio signal recording / reproducing tape cassette) or a video cassette (audio / video signal recording / reproducing tape cassette) comprises a pair of upper shells and lower shells which are superimposed on each other. ,
These are mainly mass-produced by injection molding using a styrene resin as a molding material. There are various types of tape cassettes such as compact cassettes and video cassettes due to differences in external appearance, internal shape, size, etc., and along with this, injection molding for producing these tape cassettes. There are as many molds as there are shells.

Such an injection molding die is attached to an injection molding machine to be used for the production of a molded product. Conventionally, for example, in order to maintain the accuracy of the molded product, the core block, the cavity block, etc. are generally maintained. When repair was required, or when there was a need to replace the injection mold to produce another molded product, the entire mold had to be removed from the injection molding machine. Then, the entire mold after repair of the core block or the like, or another whole mold is attached to the injection molding machine, whereby the production of the same molded product is restarted or the production of another molded product is started. It was coming out.

The work process carried out for the purpose of repairing such an injection molding die is generally as shown in FIG. FIG. 13 shows a work procedure for repairing a mold during production of a molded product. First, production is stopped (S1), and injection molding is stopped (S1).
2) The fixed-side mold and the movable-side mold that have been divided are overlapped, and both molds are fixed with a fixture (S3). Next, the injection molding die is lifted by using a crane or the like, removed from the die mounting portion of the injection molding machine (S4), and transported by a crane or the like to a predetermined position where repair is to be performed (S5).

At a predetermined position where mold repair is performed, first,
The fixture is removed (S6), and then the mounting plate and the receiving plate of the fixed side mold and the movable side mold are removed (S7). Then
The cavity block and core block are removed from each template (S8), and each block is made into a single body. Then, the cavity block and the core block are repaired by adding necessary processing and the like (S9). After that, from S1 to S
Work so that the steps up to 9 are substantially reversed.

That is, the repaired cavity block and core block are attached to the template (S10), and the template is attached to the fixed side mold and the movable side mold mounting plate and the receiving plate (S11). Next, the fixed side mold and the movable side mold are overlapped and a fixture is attached (S12), which is transported by a crane or the like (S13), and the repaired injection mold is attached to the injection molding machine (S14). ). Then, after removing the fixture (S15), injection molding is performed to mold a prototype (S16). Next, the dimensional accuracy of the prototype,
The finished state is inspected (S17), and if the molded product has a predetermined accuracy and can be used as a product, mass production is restarted (S18).

As a conventional injection molding die which is repaired through such working steps, there is, for example, one shown in FIG. FIG. 12 shows a movable side mold that constitutes one of the injection molding dies, and the movable side receiving plate 3 is on the back side of the movable side mold plate 2 having the core block 1 in the center. It is fixed by a plurality of mounting screws 4 which are screwed together. Further, a movable side mounting plate 6 is fixed to the rear surface of the movable side receiving plate 3 via a spacer block 5 by a plurality of mounting screws 7 which are also screwed from the rear side.

Further, a back plate 8 is fixed to the back surface of the core block 1 by a plurality of mounting screws 9 screwed from the back surface side, and the back plate 8 is
Similarly, it is fixed to the movable side receiving plate 3 by a plurality of mounting screws 10 screwed from the back side. Even in the small core 11 embedded in the core block 1, it is fixed to the back plate 8 by a plurality of mounting screws 12 screwed from the back side like the core block 1. Further, an ejector pin 13 whose end surface faces the front surface of the core block 1 penetrates the core block 1, the back plate 8 and the movable side receiving plate 3, and the protruding plate upper and lower parts 14 arranged on the front surface of the movable side mounting plate 6 , 15 are fixed. The upper and lower protruding plates 14 and 15 are integrally fixed by being screwed together by a plurality of mounting screws 16 inserted from the lower side 15 of the protruding plate.

The core block 1 of the injection molding die having such a structure is an important component for forming the inner surface shape of the molded product, and the dimensional accuracy of the core block 1 is 1/10.
It is required to finish the product dimension to about 1/3 of the product dimension that requires the dimension accuracy of 0 mm. Also, considering the shrinkage rate that occurs when the molten resin solidifies,
The core block 1 is processed. Therefore, in order to obtain an accurate molded product, the processing method of the core block 1 and the difference in the shrinkage ratio of each part based on the complicated uneven shape of the molded product are comprehensively examined. Is usually divided into a plurality of large and small blocks to be formed.

[0010]

However, in the conventional mold for injection molding as described above, the mold clamping force for opening and closing the mold at the time of taking out the molded product is as large as several hundred tons, and Since the injection pressure when pouring the molten resin into the mold is as high as several hundreds of kgf / cm ² , wear such as mold deviation may occur in the core block 1 or sliding failure of the ejector pin 13 may occur during continuous repeated production. Therefore, frequent quality control such as mold maintenance and repair is required. Moreover,
In this type of injection molding operation, generally, a large number of molded articles are taken. For example, an injection molding die having 8 pieces has 8 sets of core blocks and cavity blocks integrated with each other. It is provided in. Therefore, if a failure occurs in one core block of one set out of eight sets of block units, it is not possible to remove only that core block for repair, and always remove the entire mold. Needed to be repaired.

As a result, in the conventional injection molding die, all the components screwed and fixed by the mounting screws are all fastened by the mounting screws which are inserted from the back side opposite to the parting surface. When repairing or replacing the mold, it was necessary to remove the entire mold including the cavity block and the core block from the injection molding machine. Therefore, as described above, since all the work steps shown in FIG. 13 must be performed, not only the production efficiency of the molded product is poor, but also much work is required for repairing and exchanging the mold, and the work efficiency is poor. There were challenges.

The present invention has been made in view of such conventional problems, and a core block forming a part of a mold without attaching / removing the entire mold to / from an injection molding machine. Or, it can be mounted in one unit of a component called a cavity block or in a unit close to it.
An object of the present invention is to provide a mold for injection molding which can be removed, has high production efficiency of molded products, and can easily perform repair / replacement of molds.

[0013]

In order to solve the above problems and the like and to achieve the above object, at least one of the core block and the cavity block has a parting surface. It is characterized in that it is detachably fixed to the member on the movable side mold side or the member on the fixed side mold side from the side by the fixing means.

According to the present invention, which is configured as described above, it is possible to perform the mounting / removing work for each cavity block or core block, and to easily and quickly perform the repair / replacement of the mold.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 11 show an embodiment of the present invention, FIG. 1 is an explanatory view showing an injection molding machine in which the injection molding die of the present invention is used, and FIG. 2 is an injection molding die of the present invention. FIG. 3 is an explanatory view showing a cross section of one embodiment of a mold, FIG. 3 is a plan view showing a main part of a movable side mold in the injection molding mold shown in FIG. 2, and FIG. 5, FIG. 5 is a cross-sectional view taken along the line BB of FIG. 3, FIGS. 6 and 7 are cross-sectional views for explaining the replacement work of the core block, and FIGS. 8 to 11 show the relationship between the ejector pin and the positioning portion of the through hole. It is an explanatory view shown.

As shown in FIG. 1, this injection molding machine comprises a mold clamping device 20 having a direct pressure type mold clamping mechanism using a mold clamping cylinder, and an injection device 30 having a screw in-line injection unit. ing. Then, the injection molding die 40 is mounted on the mold clamping device 20 to open and close the mold as in the conventional case, and the injection device 3 is operated at the time of mold clamping.
Injection molding is performed by injecting molten resin from 0 into the cavity of the injection molding die 40.

The mold clamping device 20 includes a mold clamping cylinder 21 and a mold clamping ram 2 slidably held by the mold clamping cylinder 21.
2 and a movable platen 23 fixed to one end of the mold clamping ram 22.
And a plurality of tie bars 24 that are slidably pierced through the movable platen 23 and are arranged in parallel with each other, and these tie bars 2
4 has a fixed plate 25 to which one end is fixed, and the other end of each tie bar penetrates the flange portion 21 a of the mold clamping cylinder 21 and is fixed by tightening with a tie bar nut 26. The movable plate 23 has a movable side mold 4 of the injection molding mold 40.
1 is attached, and the fixed side mold 42 is attached to the fixed platen 25 so as to face the movable side mold 41.
The movable side mold 41 is configured to be movable back and forth with respect to 2.

Further, a booster ram 27 is inserted through the mold clamping cylinder 21, and the tip of the booster ram 27 is slidably inserted into the mold clamping ram 22.
A hydraulic device 28 is connected to its base. The hydraulic device 28 has a motor 28a, a hydraulic pump 28b, an accumulator 28c, and a servo valve 28d.
The hydraulic pressure discharged from the hydraulic pump 28b driven by a or the hydraulic pressure accumulated in the accumulator 28c passes from the servo valve 28d through the booster ram 27 to the mold clamping ram 2
2 is introduced. The cylinder chamber 2 of the mold clamping cylinder 21
An oil tank 29 is connected to 1b via an oil passage 21c.

Further, the injection device 30 has a hydraulic motor 31, a screw 32, an injection cylinder 33, a heating cylinder 34, a hopper 35, etc., and an injection nozzle 36 provided at the tip of the heating cylinder 34 has an injection molding metal. It is arranged so as to face the fixed side mold 42 of the mold 40. Screw 32 of injection device 30
Is connected to the rotary shaft of the hydraulic motor 31 and is integrally rotatable. The rotation of the screw 32 in the heated heating cylinder 34 melts the synthetic resin of the molding material supplied from the hopper 35. At the same time, the injection cylinder 33 is driven to move in the axial direction to act as a plunger, and the molten synthetic resin is extruded into the cavity of the injection molding die 40.

Therefore, a hydraulic device 37 is connected to the injection cylinder 33. The hydraulic device 37 includes a motor 37a, a hydraulic pump 37b, an accumulator 37c, and a servo valve 37d. The hydraulic pressure discharged from the hydraulic pump 37b driven by the motor 37a or the hydraulic pressure accumulated in the accumulator 37c is the servo valve. It is introduced into the hydraulic cylinder 33 from 37d. The hydraulic device 37 may be configured separately from the hydraulic device 28 of the mold clamping device 20 as in the present embodiment, or one hydraulic device 28 (or 3).
7), the other hydraulic device 37 (or 28) can also be configured to serve as the other hydraulic device.

Next, the injection molding die 40 of this embodiment applied to the injection molding machine having the above-mentioned structure will be described. As shown in FIG. 2, this injection molding die 4
0 is applied to a so-called two-cavity mold that can mold two molded products at once.

As a molded product to be injection-molded in this embodiment, various casings including a pair of upper shell and lower shell which are vertically stacked such as a compact cassette and a video cassette are listed. However, the present invention is not limited to this, and the present invention can be applied not only to the case in which the case can be configured independently but also to the molding of various articles other than the case. Further, generally, a cassette shell such as a compact cassette is mass-produced by injection molding mainly using a styrene resin (for example, ABS resin, high-impact polystyrene, etc.) as a molding material.
It is needless to say that these resins can be applied as molding materials, and other synthetic resins that can be injection-molded and injection-moldable metals other than synthetic resins can be appropriately used as molding materials.

In FIG. 2, an injection molding die 40 of this embodiment includes a movable side die 41 attached to the movable platen 23,
The fixed side mold 42 is attached to the fixed platen 25. The fixed mold 42 includes a fixed mounting plate 43, a fixed receiving plate 44, a fixed mold plate 45, and a cavity block 46.
And a fixed side receiving plate 44 on the front surface of the fixed side mounting plate 43.
Is provided, a fixed-side mold plate 45 is arranged on the front surface of the fixed-side receiving plate 44 as a member on the fixed-side mold side, and a cavity block 46 is further arranged on the front surface of the fixed-side mold plate 45.

The fixed side receiving plate 44 and the fixed side template 45 are
It is detachably tightened and fixed by a mounting screw 47 screwed from the back side. On the other hand, the fixed side mounting plate 43 and the fixed side receiving plate 44 are configured so that they can be separated by a certain distance by an adjusting screw 48. The adjusting screw 48 includes a screw member 48a having a head at one end and a female screw at the other end, and a male screw member 48b having a head at one end and a screw at the other end. Then, the screw members 48a and 48b are linearly connected in the axial direction by screwing the screw and the female screw with the heads of the respective members outside. Then, in order to secure the opening of the fixed side mounting plate 43 with respect to the fixed side receiving plate 44 by a certain distance, the fixed side receiving plate 44 is
An escape hole 48c is provided which extends through the fixed-side mold plate 45 and extends to the vicinity of the fixed-side attachment plate 43.
The adjusting screw 48 is inserted through c.

Thus, the adjusting screw 48 has the escape hole 48c.
The distance from the bottom to the head of the male screw member 48b can be moved, and the fixed side mounting plate 43 is opened by the moving distance. In this way, by constructing the fixed side mounting plate 43 to open a fixed distance, the runner can be taken out from the fixed side mold 42.

On the other hand, the cavity block 46 and the fixed side mold plate 45 are the front side parting surface 55.
It is detachably fastened and fixed by a mounting screw 49 screwed from the side. That is, pin holes and screw holes having a smaller diameter than the pin holes are concentrically provided at a plurality of positions on the fixed-side mold plate 45, and the pin holes have a cylindrical shape with sufficiently high accuracy of the outer peripheral surface. The knock pin 50 is press-fitted and fixed. Positioning holes 46a into which the knock pins 50 are detachably fitted and screw holes having a smaller diameter than the positioning holes 46a are concentrically provided at a plurality of positions of the cavity block 46 corresponding to the knock pins 50.

The positioning hole 46a of the cavity block 46 and the knock pin 50 constitute a fixed side positioning mechanism. After the knock pin 50 is fitted into the positioning hole 46a, the fixing screw 49 inserted inside the knock pin 50 is tightened to fix the fixed side mold plate 45.
With respect to the cavity block 46, the cavity block 46 can be accurately aligned and attached.

The fixed side mounting plate 4 thus stacked.
From 3 to the cavity block 46, a sprue 52 is provided, which penetrates these and communicates with the cavity 51 of the cavity block 46 at its tip. This sprue 5
The injection device 30 is provided on the side of the fixed side mounting plate 43, which is the base end of the injection device 30.
A sprue bush 53 facing the injection nozzle 36 is fitted, and an annular locate ring 54 is fixed to the outside thereof. Cavity 5 of cavity block 46
Reference numeral 1 denotes a recess forming the outer surface of the molded product, which is open to the parting surface 55, and the parting surface 55 has
A positioning pin 56 that constitutes one of the block positioning mechanisms for aligning with the core block 60 is provided so as to project toward the core block 60 side.

The fixed mold 42 having such a structure is
The fixed-side mounting plate 43 is mounted on the injection molding machine by being fixed to the fixed platen 25 by a fixing means such as a mounting screw.
Incidentally, the fixed-side template 45 and the cavity block 4 described above.
In this embodiment, two sets of the movable side positioning mechanism 6, the positioning pin 56, and the like are provided, and accordingly, two sets of the core block 60 and the like that form a pair with the cavity block 46 are also provided. ing.

The movable side mold 41 is composed of a core block 60.
And a back plate 61, an inner receiving plate 62, a movable side receiving plate 63, a spacer block 64, a movable side mounting plate 65, and a movable side template 66, and a spacer block 64 is provided on the front surface of the movable side mounting plate 65. A movable side receiving plate 63 is arranged. A concave portion 67 for the inner receiving plate 62 is provided on the front surface of the movable side receiving plate 63, and the inner receiving plate 62 is detachably mounted in the concave portion 67. Then, the inner side receiving plate 62 is moved by the plurality of mounting screws 68 inserted from the parting surface 55 side.
It is fastened and fixed to.

The inner receiving plate 62 and the movable side receiving plate 6
Reference numeral 3 designates a movable-side mold side member, and an inner receiving plate 62
A core block unit 58 including a core block 60 and a back plate 61 is provided on the front surface of the parting surface 5
It is fastened and fixed by a mounting screw 69 showing a specific example of a plurality of fixing means inserted from the 5 side. The core block 60 and the back plate 61, which form the core block unit 58, are tightened and fixed from the back side by a plurality of mounting screws 70 inserted from the back plate 61 side, and the back plate 61 is placed inside. It is attached to the inner receiving plate 62 in the arranged state. Then, the positioning pin 71, which is press-fitted into the inner receiving plate 62 and constitutes the movable side positioning mechanism, penetrates the back plate 61 and is inserted into the core block 60, whereby the core block unit 58 with respect to the inner receiving plate 62 is inserted. The positioning is done.

In this way, the core block 60 attached to the movable side mold member has a convex portion 60a of a predetermined shape which forms the inner surface of the molded product on the front surface thereof. When the mold is closed, the convex portion 60a is formed. Is inserted into the cavity 51 of the cavity block 46, and a cavity space that forms a predetermined shape of the molded product is formed in both blocks 46 and 60. A frame-shaped movable-side mold plate 66 that surrounds the core block unit 58 is clamped and fixed to the front surface of the movable-side receiving plate 63 by a plurality of mounting screws 72 that are inserted from the parting surface 55 side. Therefore, the inner receiving plate 62 to which the core block unit 58 is attached can be attached / removed from the parting surface 55 side which is the front face while the movable side template 66 is fixed to the movable side receiving plate 63. it can.

Further, the core block 60 has a cylindrical positioning bush 7 which constitutes the other part of the block positioning mechanism.
3 is attached. The positioning bush 73 is press-fitted into a hole penetrating the core block 60, and by fitting the protrusion of the knock pin 50 into the hole for the positioning bush 73, the core block 60 and the cavity block 46 are accurately adjusted. Matching the molds, both blocks 4
It is possible to precisely position between 6 and 60.

The core block unit 58, the inner side receiving plate 62, and the movable side receiving plate 63 having the above-described structure are provided with a plurality of through holes 74 and 75 of different diameters which penetrate the core block unit 58 and the movable side receiving plate 63 in the front-rear direction. Plural types of ejector pins 76 and 77 having a thickness corresponding to the respective diameters are slidably inserted into the through holes 74 and 75. These ejector pins 76, 77
Fixing portions 76a and 77a each having an outer diameter larger than those of the other portions are provided at one end of the first and second fixing plates 76a and 77a.
The plurality of ejector pins 76 and 77 of a plurality of types are fixed to the projecting plate 78 by being sandwiched by b. The projecting plate 78 is arranged on the back side of the movable side receiving plate 63, and has a first plate 78a and a second plate 78b.
Is detachably fastened and fixed by a plurality of mounting screws 79 screwed from the back side.

These ejector pins 76 and 77 penetrate through the through holes 74 and 75, respectively, and their front end surfaces face the cavity 51. By advancing them at the time of mold opening and projecting them from the core surface, the ejector pins 76 and 77 are inserted into the cavity 51. It plays the role of ejecting the injection-molded molded product and separating it from the core block 60. Therefore, the ejector pin 7
As shown in FIG. 3, 6 and 77 are arranged substantially evenly in a plurality of places according to the size of the molded product, and the pin thickness is appropriately set in consideration of the peel resistance of the molded product. It is set.

Incidentally, the molded product shown in this embodiment is applied to a cassette shell of a compact cassette (audio signal recording / reproducing tape cassette), and in order to project this cassette shell, in this embodiment, the shaft diameter is 8 ejector pins in total, that is, two large-diameter ejector pins 76 having a large diameter and six small-diameter ejector pins 77 having a smaller shaft diameter are used.

The through holes 74 and 75 into which the ejector pins 76 and 77 are inserted have a structure as shown in FIGS. 4 and 8 regardless of the size of the diameter. That is, the through holes 74 and 75 are formed in the core block unit 58.
Side through holes 74a and 75a and receiving plate side through holes 74b and 75b which are continuous in series with the through holes 74a and 75a.

One of the through holes 74a and 75a is a positioning portion 80a formed on the parting surface 55 side and having an appropriate length.
And a loose fitting portion 80c formed on the side opposite to the parting surface 55 side with a diameter larger than the diameter of the positioning portion 80a.
And a tapered guide portion 80e that allows the positioning portion 80a and the loose fitting portion 80c to be gently continuous.
The other through holes 74b and 75b are formed on the parting surface 55 side and a positioning portion 80b having an appropriate length, and are formed on the side opposite to the parting surface 55 side with a diameter larger than the diameter of the positioning portion 80b. It also has a loose fitting portion 80d and a tapered guide portion 80f for gently connecting the positioning portion 80b and the loose fitting portion 80d. Then, the through holes 74a and 75a on the core block unit 58 side
The positioning portion 80a of the above constitutes the first positioning portion, and the positioning portions 80b of the through holes 74b and 75b on the receiving plate side constitute the second positioning portion.

The diameter of the first and second positioning portions 80a is
The ejector pin is slidably inserted into these and has a diameter substantially equal to that of the ejector pin. Here, "the diameter of the first and second positioning portions 80a is substantially the same as the diameter of the ejector pin" means that "the diameter of the ejector pin is substantially the same as that of the ejector pin and the sliding movement of the ejector pin can be ensured." It means the size with the gap. ” For example, JI
In the S fitting method, of the clearances that always have a "clearance" between the hole and the shaft, those with hole tolerances of H6 and H7 are preferable, but a slightly larger "clearance" is required. It may have one (for example, a hole having a tolerance of about G6 or G7). On the other hand, the diameter of the loose fitting portion 80b is sufficiently larger than the diameter of the ejector pin, and the loose fitting portion 80b has a sufficient "clearance" between itself and the ejector pin.

Further, the inner receiving plate 62 and the movable receiving plate 63
A through-hole 81 is formed through the through hole 81 in the front-rear direction, and a link rod 82 is slidably inserted through the through-hole 81. At both ends of this link rod 82,
Head 8 with each outer diameter thicker than the shaft diameter in the middle
2a and 82b are provided, and one head portion 82b can be configured to be attachable to and detachable from the receiving plates 62 and 63 by being formed of a nut and screwed and fixed.
The head portion 82b may be press-fitted into one end of the link rod 82.

Thus, by providing the link rod 82 which can advance and retreat in the axial direction by a certain distance, the amount of protrusion of the inner receiving plate 62 can be limited. Then, by limiting the protrusion amount of the inner receiving plate 62 with the link rod 82, the inner receiving plate 62 is prevented from falling off from the movable side receiving plate 63. The stroke amount of the link rod 82 is such that the tip of each ejector pin 76, 77 has a corresponding one of the through holes 74, 75 when the inner receiving plate 62 is most protruded.
It is set so as to be located in the second positioning portion 80a.

The movable side receiving plate 63 and the movable side mounting plate 6
5 is a spacer block 64 interposed therebetween,
It is detachably fastened and fixed by a mounting screw 83 screwed from the back side. Then, the movable side receiving plate 63 surrounded by the spacer block 64 and the movable side mounting plate 65.
A projecting plate 78 to which the fixing portions 76a and 77a of the ejector pins 76 and 77 are fixed is arranged in the rear side space portion of the. A shaft portion of a guide shaft 84 screwed and fixed to the movable side receiving plate 63 is slidably inserted into the projecting plate 78, and the projecting plate 78 is slidable by being guided by the guide shaft 84. Is held.

That is, the first plate 78a of the protruding plate 78 is provided with a hole through which the shaft portion of the guide shaft 84 is slidably inserted, and the second plate 78b is provided with the head of the guide shaft 84. A hole is provided through which the part is slidably inserted. A return spring 85 is attached to the shaft portion of the guide shaft 84 so as to bias the protruding plate 78 in the direction of separating it from the movable side receiving plate 63. Further, a stopper block 86 is fastened and fixed to the back surface of the movable side receiving plate 63 by a mounting screw 87, and the stopper block 86 limits the movement of the protruding plate 78 to the front side. Therefore, the protruding plate 78 is provided on the head of the guide shaft 84 and the stopper block 8.
6 can be moved forward and backward with respect to 6, and if it abuts on the link rod 82 before abutting on the stopper block 86,
Since the link rod 82 slides in the axial direction, the link rod 8
The presence of 2 does not hinder the ejection of the ejector pins 76 and 77.

Further, a mounting screw 8 is provided on the rear side of the protruding plate 78.
The ejector block 89 is fixed by 8.
The ejector block 89 is housed in a through hole 90 provided in the movable side mounting plate 65, and the tip of a projecting rod 91 provided in the injection molding machine and capable of advancing and retracting is provided on the outer surface portion of the ejector block 89. Facing. Therefore,
By moving the projecting rod 91 forward and backward to move the projecting plate 78 forward and backward, a plurality of ejector pins 7 are integrally formed with the projecting plate 78.
6, 77 advance and retreat, and the ejecting operation of the molded product is executed. The ejector pins 76, 77, the projecting plate 78, the guide shaft 84, the ejector block 89, and the projecting rod 91 constitute a projecting mechanism.

Although not shown, the cavity block 46 and the core block 60 are provided with cooling passages through which water, which is a specific example of a cooling medium, flows, and these cooling passages are fixed side molds. The fixed-side receiving plate 44 and the movable-side receiving plate 6 are provided through passages provided in the plate 45 and the back plate 61.
Each of the passages 3 is connected to an external cooling device. Therefore, the movable side mold 4 is cooled by the cooling water supplied from the cooling device.
The 1 and the stationary mold 42 are forcibly cooled respectively.

Injection molding die 4 having such a structure
For example, 0 is attached to an injection molding machine as follows and is used for injection molding of a molded product having a predetermined shape.
In this case, in the fixed-side mold 42 that constitutes one of the injection molding dies 40, the fixed-side mounting plate 43, the fixed-side receiving plate 44, and the fixed-side mold plate 45 are fixed to the fixed plate 25 of the injection molding machine in advance. In the movable side mold 41 constituting the other side, the movable side mounting plate 65, the spacer block 64, the movable side receiving plate 63, and the inner side receiving plate 62 are fixed in advance to the movable platen 23 of the injection molding machine.

Therefore, when repairing the cavity block 46 or the core block 60 or exchanging a die for manufacturing another molded product, only the cavity block 46 of the fixed-side die 42 is to be exchanged, and the movable side die 42 is also movable. In the mold 41, only the core block unit 58 is to be replaced.

First, the mounting operation of the cavity block 46 of the fixed mold 42 will be described. In FIG. 2, when the cavity block 46 is removed from the fixed-side mold plate 45, the mounting screw 49 that fixes the cavity block 46 to the fixed-side mold plate 45 only needs to be removed from the front parting surface 55 side.

In this case, the fastening force of the cavity block 46 is released by removing the plurality of mounting screws 49 that fasten and fix the cavity block 46, so that the cavity block 46 is attached to the knock pin 50. The cavity block 46 can be removed from the fixed-side mold plate 45 very easily by pulling out along the same. Moreover, since other components such as the fixed side mounting plate are not coupled to the cavity block 46 as in the conventional case, and the cavity block 46 is removed by itself, it is possible to proceed to repair / remodeling work as it is. It enables quick work and improves work efficiency such as repair and modification.

On the other hand, when the cavity block 46 is attached to the fixed-side mold plate 45, first, the positioning hole 46a opened on the back side of the cavity block 46 is attached to the knock pin 50 planted in the fixed-side mold plate 45. After aligning, align the cavity block 46 with the knock pin 5
Push in along 0. Next, the front parting surface 55
From the side, the mounting screw 49 is inserted into the bolt hole of the cavity block 46, and the threaded portion at the tip thereof is passed through the hole of the knock pin 50 and screwed into the screw hole of the fixed-side template 45. Then, the cavity block 46 is fixed to the fixed-side template 45 by tightening the mounting screw 49.

In this case, since the knock pin 50 having sufficiently high accuracy is planted in the fixed side template 45 at a predetermined position, it is only necessary to align the positioning hole 46a of the cavity block 46 with the knock pin 50. Sufficient positioning accuracy of the cavity block 46 with respect to the template 45 can be ensured.

Next, the mounting operation of the core block unit of the movable side mold 41 will be described. When removing the core block unit 58 from the movable side receiving plate 63, first, from the state shown in FIGS. 4 and 5, remove the plurality of mounting screws 68 that fix the inner side receiving plate 62 to the movable side receiving plate 63. , The contact surface between the inner receiving plate 62 and the movable side receiving plate 63 is made free. Then, as shown in FIG. 6, the inner receiving plate 62 in which the core block unit 58 is fixed is pulled out from the recess 67, and the core block unit 58 and the like are exposed by the movement amount of the link rod 82.

As a result, the inner receiving plate 62 including the core block unit 58 is exposed to the front side of the front surface of the movable side mold plate 66, and the inner side receiving plate 62 is an inner peripheral edge of the movable side mold plate 66. Is supported by the core block unit 58 and is prevented from bending on the core block unit 58 side. Further, the tip ends of the ejector pins 76 and 77 are relatively retracted from the first positioning portion 80a to the second positioning portion 80b by causing the core block unit 58 and the inner receiving plate 62 integral with the core block unit 58 to protrude by the maximum amount. Will move. Therefore, when the core block unit 58 or the like is housed or projected, the tip of each ejector pin 76, 77 is always positioned at either the first or second positioning portion 80a, 80b, and thus there is no rattling. Held in.

Next, the plurality of mounting screws 69 for fixing the core block unit 58 to the inner receiving plate 62 are loosened and removed from the parting surface 55 side. As a result, the tightening force of the core block unit 58 is released and becomes free. Therefore, as shown in FIG. 7, by pulling out along the positioning pin 71, the core block unit 58 is easily removed from the inner receiving plate 62. be able to.

Therefore, when the mold is exchanged to manufacture another molded product, the removed core block unit is replaced with another core block unit as described later. When repairing or modifying the core block 60, in the state of the core block unit 58,
Alternatively, by repairing the core block 60 by removing the plurality of mounting screws 70 connecting the core block 60 and the back plate 61 to separate the core block 60 from the back plate 61. .

Therefore, also with respect to the core block 60, the core block 60 can be extremely easily removed from the movable side receiving plate 63 by the work from the parting surface 55 side, as in the case of the cavity block 46. Moreover, since other parts such as the movable side mounting plate are not coupled to the core block unit 58 as in the conventional case, the core block unit 58 can be handled as one unit, so that repair / remodeling work can be performed as it is. It is possible to improve the work efficiency such as repair and modification by enabling quick work.

When the core block 60 is repaired or modified, the back plate 61 is combined with the core block 60 to form the core block unit 58. Then, the core block unit 58 is attached to the inner receiving plate 62. In this case, first, the positioning pin 71 standing on the inner receiving plate 62 is aligned with the positioning hole opened on the back side of the core block unit 58, and is inserted along the positioning pin 71. Next, a plurality of mounting screws 69 are inserted into the bolt holes of the core block unit 58 from the parting surface 55 side, and the screw shaft portions of the respective mounting screws 69 are screwed into the screw holes of the inner receiving plate 62 to be fixed by tightening. (State of FIG. 6).

Next, the inner block 62 is inserted into the recess 67 of the movable support plate 63 by pushing the core block unit 58 into the movable mold plate 66. Then, the back surface of the inner receiving plate 62 is brought into contact with the bottom surface of the concave portion 67, and the inner receiving plate 62 is fixed to the movable side receiving plate 63 by tightening the plurality of mounting screws 68. This allows
The core block unit 58 is fixed to the movable side receiving plate 63 via the inner side receiving plate 62. Therefore, the work of attaching the core block unit 58 can also be easily and quickly executed.

In this case, as shown in FIG. 6, when the core block unit 58 is fixed to the inner receiving plate 62, the two through holes 74a and 74b forming the through holes 74 and 75 through which the ejector pins 76 and 77 are inserted. Since 75a and 75a are installed concentrically and confronting each other, there is no risk that the tips of the ejector pins 76 and 77 will abut the peripheral edges of the through holes 74a and 75a on the back plate 61 side during insertion, and the through holes 74a and It can be inserted in 75a.
Moreover, the positioning portions 80a, 80b and the loose fitting portions 80c, 8
Since the tapered guide portions 80e and 80f are provided between 0d and 0d, the loose fitting portion 8 having a large "clearance".
Even when the tips of the ejector pins 76 and 77 enter from the 0c and 80d to the positioning sections 80a and 80b having almost no "clearance", they can be smoothly guided by the guide sections 80e and 80f.

Therefore, at the time of assembling the core block unit 58, there is no possibility that the ejector pins 76 and 77 will hit the peripheral edges of the through holes 74a and 75a and be bent or bent, so that the core block unit 58 can be easily and reliably assembled. It can be carried out.

When the core block 60 is aligned with the cavity block 46, the injection molding machine is operated to move the movable platen 23 to bring the core block 60 close to the cavity block 46.
The positioning bush 73 attached to 0 approaches the positioning pin 56 attached to the cavity block 46, and this positioning pin 56 enters into the hole of the positioning bush 73, so that both blocks 46 and 60 are reliably positioned and closed. can do. Therefore, there is no possibility of producing a molded product in which the mold is out of alignment, and a molded product without burr or with a small burr can be manufactured.

Next, the ejecting operation of the molded product will be described. This ejecting operation is performed after the mold is opened after the injection-molded molded product is solidified. Therefore, here, the description will be given from the state where the movable mold 41 is retracted and separated from the fixed mold 42 by the operation of the injection molding machine, and the injection molding mold 40 is opened.

Projecting rod 9 provided in the injection molding machine
When 1 is moved forward, the protruding rod 91 abuts against the ejector block 89 and pushes it out, and the protruding plate 78 connected to the ejector block 89 is advanced against the biasing force of the return spring 85. As a result, the ejector pins 76 and 77 having the fixing portions 76a and 77a fixed to the protruding plate 88 move forward, and the ejector pins 7
The molded product adhered to the core block 60 is peeled off and protruded by 6,77.

Next, when the projecting rod 91 is retracted, the pressing force of the ejector block 89 is released, and the projecting plate 78 is retracted by the urging force of the return spring 85, whereby the ejector pins 76 and 77 are moved to the core. Block 6
It is pulled back to the 0 side, and the mold with the cavity block 46 can be closed. As a result, the injection molding machine is operated as described above, and the movable side mold 41 is aligned with the fixed side mold 42 to close the mold, thereby completing the preparation for the next injection molding.

Although the present invention has been described above, the present invention is not limited to the above-described embodiment. For example, as the structure of the injection molding machine, a plunger type or screw pre-plastic type injection molding machine other than the screw in-line type may be used. Can be
Further, the shape, size, and the like of the cavity block and the core block are not limited to those illustrated. Further, in the above embodiment, an example in which a hydraulic device is used as the mold driving means of the injection molding machine has been described, but a pneumatic device or another driving device can also be used. Further, in the above embodiment, the cavity block 46 and the core block 6 are
Although the example in which both of 0 are removable from the parting surface 55 side has been described, the present invention is not limited to the cavity block 46.
Alternatively, the configuration may be applied to only one of the core blocks 60.

Further, in the above-described embodiment, the fixed side mold 42 is provided with the fixed side positioning mechanism (positioning hole 46a and knock pin 50).
Consists of ) Is provided and the movable side mold 41 is provided with the movable side positioning mechanism (comprising the positioning pin 71 and the positioning hole therefor). However, the configurations of these positioning mechanisms can be reversed. . Furthermore, an example of applying it to a tape cassette such as a compact cassette or a video cassette as a molded product has been described.
The metal mold is not limited to a die for a tape cassette, and it can be used not only for various types of casings such as compact disc cartridges and floppy disc cartridges, but also for injection molding for manufacturing various molded products other than casings. It can be used as a mold.

Furthermore, as an example of the structure of the injection molding die,
In the above embodiment, the example applied to the cold runner type mold has been described, but it can also be applied to the hot runner type and semi-hot runner type molds. Thus, the present invention can be variously modified without departing from the spirit thereof.

[0068]

As described above, according to the present invention,
With the injection molding die attached to the injection molding machine, from the parting surface to the cavity block of the movable side mold,
For fixed side core block or core block unit can be attached / detached, installation / removal work can be performed very easily and quickly, and the time required for maintenance / repair can be greatly shortened. A mold can be provided. In addition, the mold can be replaced by replacing the cavity block, the core block, or the core block unit, and it is easy to switch the type of the molded product, and one mold can be used for a plurality of types. Molded products can be molded at the same time, and production of different manufacturing types (for example, small lot production of various types and mass production of small types)
It is possible to provide an injection-molding die that can handle the above.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing an embodiment of an injection molding machine in which a mold for injection molding of the present invention is used.

FIG. 2 is a cross-sectional view showing an embodiment of the injection molding die of the present invention.

FIG. 3 is an enlarged plan view showing a main part of a movable side mold relating to the injection molding mold shown in FIG.

FIG. 4 is a view showing a movable side mold A of the injection molding mold shown in FIG.
FIG. 4 is a cross-sectional view taken along a line A.

5 is a movable side mold B of the injection molding mold shown in FIG.
FIG. 4 is a cross-sectional view taken along line B.

FIG. 6 is an explanatory view showing an operating state of a movable side die according to the injection-molding die of the present invention, showing a state in which a core block and the like are projected, in a sectional view.

FIG. 7 is an explanatory view showing an operating state of the movable side die according to the injection-molding die of the present invention, showing a state in which the core block unit is removed in section.

FIG. 8 is an explanatory diagram showing a relationship between a through hole of a movable side mold and an ejector pin according to the injection molding mold of the present invention.

FIG. 9 is an explanatory view showing a state in which the tip of the ejector pin passes through the loose fitting portion of the through hole of the movable mold according to the injection molding die of the present invention.

FIG. 10 is an explanatory view showing a state in which the tip of the ejector pin passes through the guide portion of the through hole of the movable mold according to the injection molding die of the present invention.

FIG. 11 is an explanatory diagram showing a state in which the tip of the ejector pin passes through the positioning portion of the through hole of the movable mold according to the injection molding die of the present invention.

FIG. 12 is a cross-sectional view showing a conventional injection molding die.

FIG. 13 is a block diagram for explaining a general work of exchanging a mold for injection molding.

[Explanation of symbols]

 40 Injection Mold 41 Movable Side Mold 42 Fixed Side Mold 45 Fixed Side Mold Plate (Member on Fixed Side Mold Side) 46 Cavity Block 49 Mounting Screw (Fixing Means) 51 Cavity 55 Parting Surface 58 Core Block Unit 60 Core Block 61 back plate 62 inner receiving plate (member on movable side mold side) 63 movable side receiving plate 66 movable side mold plate 67 recessed portion 69 mounting screw (fixing means) 74, 75 through hole 76, 77 ejector pin 78 protruding plate 80a 1 Positioning part 80b Second positioning part 80e, 80f Guide part 82 Link rod

Claims (4)

[Claims] 1. A movable side mold having a core block forming an inner surface of a molded product and a fixed side mold having a cavity block forming an outer surface of the molded product, wherein the movable side mold and the fixed side mold are provided. In the injection molding die in which the parting surface is detachable, at least one of the core block and the cavity block is from the parting surface side to the movable side mold side member or the fixed side mold side member. An injection molding die characterized in that it is detachably fixed by a fixing means. 2. The mold for injection molding according to claim 1, wherein the core block is detachably fixed from a parting surface side to a receiving plate of the movable side mold by a fixing means, and the movable side mold. Is slidably inserted into a through-hole penetrating the receiving plate and opening in the core block, and a front end surface thereof faces a cavity formed by the core block and the cavity block and advances when the mold is opened. A protruding mechanism having an ejector pin for ejecting the molded product molded in the cavity to separate it from the core block is provided, and the diameter of the ejector pin is almost equal to the diameter of the ejector pin at the end of the through hole on the parting surface side. An injection molding die, which is provided with a positioning portion having the same diameter. 3. The injection molding die according to claim 2, wherein the through hole is formed at an end portion on the parting surface side and has a positioning portion having a diameter substantially equal to a diameter of the ejector pin. A loose fitting portion formed on the side opposite to the parting surface side and having a diameter larger than the diameter of the positioning portion, and a tapered guide portion for gently continuing the positioning portion and the loose fitting portion. An injection-molding die characterized by being formed by. 4. The injection molding die according to claim 2, wherein the receiving plate is a movable side receiving plate fixed to a movable side attaching plate for attaching to a movable plate of an injection molding machine, and the movable side receiving plate. An inner receiving plate slidably supported by the plate, and a link rod for restricting the protruding amount of the inner receiving plate is provided between the movable side receiving plate and the inner receiving plate. An injection molding die, wherein a tip of the ejector pin is positioned at a positioning portion provided on the receiving plate of the through hole.