JPH09131766A - Mold for injection molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attach composing parts in one unit and make them detachable by providing, at a fixed-side mold, a positioning mechanism for positioning an interval between a cavity block and a member at the fixed-side mold and detachably fixing the cavity block to the member at the fixed-side mold from a parting face. SOLUTION: An injection molding die is formed of a movable-side mold and a fixed-side mold and a fixed-side positioning mechanism is formed of a positioning hole 46a of a cavity block 46 of the fixed-side mold and a knock pin 50. The pin 50 is fitted in the positioning hole 46a and a mounting screw 49 is clamped, so that the block 46 is attached to a retainer plate 45 by registering with a high precision. At the cavity block 46, a positioning pin 56 which forms a block positioning mechanism is provided. A protrusion 56b of the pin 56 is fitted in a positioning hole 72a of a positioning bush 72 arranged at a core block 61, so that mold registering of a core block 61 and the cavity block 46 is done with a high precision.

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 injection molding dies for solidifying to obtain molded products, especially, only the cavity block or core block with the fixed side mold or the movable side mold attached to the 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 producing a molded product, but conventionally, for example, maintenance and repair of a cavity block or the like is generally required to maintain the accuracy of the molded product. In the case of, or when it becomes necessary to replace the injection molding die in order to produce another molded product, it is necessary to remove the entire die from the injection molding machine. Then, the entire mold after repairing the cavity block, etc., or another 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. 6 shows a work procedure for repairing a mold during production of a molded product. First, production is stopped (S1), injection molding is stopped (S2), and then division is performed. The fixed-side mold and the movable-side mold that have been formed are overlapped, and both molds are fixed by 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 that is repaired through such working steps, there is, for example, one shown in FIG. FIG. 5 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 are fastened with mounting screws that are inserted from the back side opposite to the parting surface.When repairing or replacing the mold, it is necessary to remove the entire mold including the cavity block and core block from the injection molding machine. there were. Therefore, as described above, since all the work steps shown in FIG. 6 have to be performed, not only the production efficiency of the molded product is poor, but also much work is required for repairing and exchanging the dies, and the work efficiency is poor. There were challenges.

The present invention has been made in view of such conventional problems, and a cavity block forming a part of a mold without attaching / removing the entire mold to / from an injection molding machine. Or, one unit of the component called core block or a unit close to it is attached.
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]

The injection mold of the present invention has at least one of a fixed side mold and a movable side mold in order to solve the above-mentioned problems and the like and to achieve the above object. A fixed-side positioning mechanism for positioning between the cavity block and the fixed-side mold side member, or a movable-side positioning mechanism for positioning between the core block and the movable-side mold side member, and a cavity block provided with the positioning mechanism, or The core block is characterized in that it is detachably fixed to the member on the fixed side mold side or the member on the movable side mold side from the parting surface side by the fixing means.

According to the present invention, which is configured as described above, each cavity block or core block can be attached / detached, and the die can be easily repaired / replaced.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 4 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 an explanatory view showing a cross section of a main part of a movable side mold of the injection molding mold shown in FIG. 2, and FIG. 4 is an injection molding shown in FIG. It is sectional drawing which expands and shows the cavity block of a movable side die | dye and the core block of a fixed side die | dye in a metal mold | die.

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 fastened 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 can move a distance from the bottom of the escape hole 48c to the head of the male screw member 48b, 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 detachably fastened and fixed by the mounting screw 49 screwed from the parting surface side which is the front side. That is, as shown in an enlarged view of the main part of FIG. 2 in FIG. 4, pin holes and screw holes having a smaller diameter than the pin holes are concentrically provided at a plurality of locations on the fixed-side template 45, and A cylindrical knock pin 50 whose outer peripheral surface has a sufficiently high accuracy is press-fitted and fixed in the pin hole. This knock pin 5
Corresponding to 0, a plurality of positions of the cavity block 46 are provided with a positioning hole 46a into which the knock pin 50 is removably fitted and a screw hole having a smaller diameter than the positioning hole 46a.

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.
3 to the cavity block 46, the sprue 52 which penetrates these and communicates with the cavity 51 whose tip forms the outer surface of the molded product formed in the cavity block 46.
Is provided. A sprue bush 53 facing the injection nozzle 36 of the injection device 30 is fitted to the fixed side mounting plate 43 side which is the base end of the sprue 52, and an annular locate ring 54 is fixed to the outside thereof. There is.

Further, the cavity block 46 is provided with a positioning pin 56 which constitutes one of the block positioning mechanisms 55 for precise alignment with the core block 61. The positioning pin 56 includes a fixed portion 56a housed in a concave portion 46b opened on the front surface side where the cavity 51 of the cavity block 46 is opened, and a concave portion 46b continuous from one side in the axial direction of the fixed portion 56a. It is composed of a protruding portion 56b protruding. Then, the fixing screw 5 screwed from the fixed side template 45 side which is the back side
It is fixed to the cavity block 46 by 7.

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. In this embodiment, two sets of the fixed-side template 45 and the cavity block 46, and the movable-side positioning mechanism and the positioning pin 56 related to them are provided. Therefore, the core block and the core described later are provided. Similarly, two sets of block units are provided.

As shown in FIGS. 2 and 3, the movable side die 41 has a core block 61, a back plate 62, a movable side receiving plate 63, a spacer block 64, and a movable side mounting plate 65. A core plate 60 forming the inner surface of the molded product is fixed to the front surface of the block 61. The movable-side receiving plate 63 is arranged on the front surface of the movable-side mounting plate 65 via the spacer block 64. The movable-side receiving plate 63 constitutes a movable-side mold side member, and the back plate 62 is arranged on the front surface of the movable-side receiving plate 63.
Further, the core block 61 is arranged on the front surface of the back plate 62. The movable side mounting plate 65 and the movable side receiving plate 63, and the back plate 62 and the core block 61 are mounted on the rear side of the mounting screws 66 and 67, respectively.
It is detachably fastened and fixed by.

On the other hand, the core block assembly 69, in which the core block 61 and the back plate 62 are fastened together by the mounting screws 67 and assembled integrally, is fixed by being inserted from the core block 61 side which is the front side. It is detachably fastened and fixed to the movable side receiving plate 63 by a mounting screw 68 showing a specific example of the means. That is, as shown in FIG. 3 and FIG. 4 in which the main part of FIG. 2 is enlarged, pin holes 69a penetrating the core block 61 and the back plate 62 at a plurality of positions and a diameter larger than the pin hole 69a. Counterbore 6
9b and 9b are provided concentrically.

Pin holes 69 of this core block assembly 69
Cylindrical knock pins 70 are press-fitted and fixed to a plurality of positions of the movable side receiving plate 63 corresponding to a. The shaft diameter of the portion of the knock pin 70 projecting to the front surface of the movable side receiving plate 63 is formed to be smaller than the inner diameter of the pin hole 69a.
A disc spring 7 showing a specific example of an elastic member between the knock pin 70 and the mounting screw 68 while providing a slight gap therebetween.
By interposing 1, the followability of the core block assembly 69 with respect to the displacement of the cavity block 46 is secured. The mounting screw 68 is inserted into the hole of the knock pin 70, and the screw shaft portion at the tip is screwed into the screw hole portion of the movable side receiving plate 63 to be tightened, so that the core block assembly 69 is caused by the spring force of the disc spring 71. Are pressed and supported by the movable side receiving plate 63.

Further, a positioning bush 72, which constitutes the other side of the block positioning mechanism 55, is attached to the core block 61. The positioning bush 72 is accommodated in a bush accommodating hole 73 opened on the front surface side from which the core plate 60 of the core block 61 projects, and on the front surface side, a positioning pin 56 provided on the cavity block 46.
A positioning hole 72a into which the protrusion 56b is fitted is provided. Positioning hole 72a of the positioning bush 72
By fitting the protrusion portion 56b to the core block 61 and the cavity block 46, the core block 61 and the cavity block 46 can be accurately matched with each other to precisely position the blocks 46, 61.

The positioning bush 72 is screwed and fixed to the screw block 75 by a mounting screw 74 screwed from the opposite side of the positioning hole 72a.
It is attached to the core block 61 via. The back plate 62 disposed on the back side of the core block 61 prevents the core block 61 from coming off. Further, the back plate 62 includes a plurality of mounting screws 7 screwed from the back side.
It is detachably fastened and fixed by 6.

Thus, the front surface of the cavity block 46 and the front surface of the core block 61 form a parting surface 79, and the parting surface 79 is abutted to close the cavity block 46 and the core block 61, whereby the cavity 51 is closed. The core plate 60 is inserted therein, and a molding space having a predetermined shape for a molded product is formed between the cavity 51 and the core plate 60.

The core block assembly 69 having the above-described structure is provided with through holes penetrating in the front-rear direction, and the ejector pin 77 is provided in one of the through holes.
Is slidably inserted, and a connection bolt 78 for connecting the ejector plate 80 is slidably inserted into the other through hole. Fixing portions 77a and 78a each having an outer diameter larger than that of the shaft portion are provided at one end of each shaft portion of the ejector pin 77 and the connecting bolt 78. Plate 80
By sandwiching the ejector pin 77 with a and 80b,
Also, the connection bolt 78 is fixed to the ejector plate 80.

The first plate 80a and the second plate 80b of the ejector plate 80 are detachably fastened and fixed by a plurality of mounting screws 95 screwed from the back side. The ejector plate 80 slidably connected to the core block assembly 69 via the connecting bolts 78 and the like is housed in a recess 81 provided so as to open to the front side of the movable side receiving plate 63. The core block assembly 69 can be moved toward and away from the core block assembly 69.

The ejector pin 77 and the connecting bolt 7
8 is an upper plate 80a and a back plate 62, respectively.
The core block 61 and the core plate 60 are penetrated, and the respective tip surfaces are exposed on the parting surface 79 side. Therefore, the respective tip surfaces of the ejector pin 77 and the connection bolt 78 form a part of the inner surface of the molded product. Further, the connecting bolt 78 is attached to the tip surface of the connecting bolt 78.
A wrench hole 78b for rotating is provided, and a screw shaft portion 78c projecting toward the lower plate 80b is provided on the opposite side of the fixed portion 78a. The tip end portion of the ejector rod 82 that penetrates the movable-side receiving plate 63 from the back side is screwed into the screw shaft portion 78c of the connection bolt 78.

Further, a bush hole 83 is penetrated through the ejector plate 80, and a guide pin 85 is slidably inserted through a guide pin bush 84 fitted and fixed in the bush hole 83. One end of the guide pin 85 is press-fitted and fixed to the back plate 62, and the other end faces the bottom surface of the recess 81. Therefore, the ejector plate 80 is guided by the guide pin 85 to move forward or backward, and the movement at the time of the backward movement is limited by the stopper 87 fixed to the bottom surface of the recess 81 by the mounting screw 86.

The ejector plate 80 and the ejector pin 77 protruding toward the cavity by the forward movement of the ejector plate 80 constitute a core side protruding mechanism for separating the molded product from the core block 61. And
The core block assembly 69 and the ejector plate 80, which are integrated via the connecting bolt 78 and the guide pin 85, constitute a core block unit that can be independently attached to and detached from the movable side receiving plate 63. .

Further, as shown in FIGS. 2 and 3, a projecting plate 88 is arranged in the space surrounded by the spacer block 64 on the rear side of the movable side receiving plate 63 and the movable side mounting plate 65. The fixed portion 82a of the ejector rod 82 is fixed to the protruding plate 88. The projecting plate 88 is composed of a first projecting plate 88a and a second projecting plate 88b that are overlapped with each other, and both projecting plates 88a and 88b are detachably fastened by a plurality of mounting screws 89 screwed from the back side. It is fixed. Then, the fixed portion 82 of the ejector rod 82
The a is provided with a protrusion 82b protruding outward in the radial direction, and the protrusion 82b is engaged with the engagement groove of the first guide plate 88a to prevent the ejector rod 82 from rotating. .

The protruding plate 88 is slidably guided by a guide screw 90 screwed and fixed to the movable side receiving plate 63. That is, the first protruding plate 88a of the protruding plate 88 is provided with a hole through which the shaft portion of the guide screw 90 is slidably inserted, and the second protruding plate 88b is provided with a head portion of the guide screw 90. Is provided so as to be slidably inserted. The protruding plate 88 is attached to the shaft of the guide screw 90.
A return spring 95 for urging the movable support plate 63 away from the movable side receiving plate 63 is attached. Therefore, the protruding plate 88
Can move back and forth between the head of the guide screw 90 and the movable side receiving plate 63.

Further, a mounting screw 9 is provided on the rear side of the protruding plate 88.
The ejector block 92 is fixed by 1.
The ejector block 92 is housed in a through hole 93 provided in the movable side mounting plate 65, and an outer surface of the ejector block 92 is provided with a tip of a projecting rod 94 provided in the injection molding machine and capable of advancing and retracting. Facing. Therefore,
By moving the projecting rod 94 forward and backward to move the ejector rod 82 forward and backward, the core-side projecting mechanism advances and retracts integrally with this, and the ejecting operation of the molded product by the ejector pin 77 is executed. The projecting rod 94, the ejector block 92, the projecting plate 88, and the ejector rod 82 constitute a main projecting mechanism for operating the core-side projecting mechanism.

Although not shown, the cavity block 46 and the core block 61 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 the passages provided in the plate 45 and the back plate 62.
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.
1 and the fixed-side mold 42 are capable of forced cooling, 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. The movable side die 41 constituting the other side has its movable side mounting plate 65, spacer block 64, and movable side receiving plate 63 fixed in advance to the movable platen 23 of the injection molding machine.

Therefore, when repairing the cavity block 46 or the core block 61 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 movable. In the mold 41, only the core block unit separated from the eject rod 82 is to be replaced.

First, the mounting operation of the cavity block 46 of the fixed mold 42 will be described. As shown in FIGS. 2 and 4, when the cavity block 46 is removed from the fixed-side mold plate 45, the mounting screw 49 fixing the cavity block 46 to the fixed-side mold plate 45 is attached to the front parting surface 79 side. Just remove it from

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 79
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 with 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. As shown in FIGS. 2 and 3, when removing the core block unit from the movable side receiving plate 63, first, the connection between the connecting bolt 78 and the ejector rod 82 is released to separate the core block unit from the projecting plate 88. Let That is, from the front parting surface 79 side, the front end of the wrench is engaged with the wrench hole 78b of the connection bolt 78 and rotated in a direction of loosening. In this case, the ejector rod 82 screw-connected to the screw shaft portion 78c of the connection bolt 78 is provided by the rotation stopping mechanism in which the protrusion 82b provided on the fixing portion 82a is engaged with the groove of the first protruding plate 88a. Since it is non-rotatable, the ejector rod 82 is not rotated together with the rotation of the connection bolt 78, and only the connection bolt 78 can be rotated to release the screwed state.

When the connecting bolt 78 is rotated in the releasing direction as described above, the core block assembly 69 forming one of the core block units and the ejector plate 80 forming the other of the core block unit, the connecting bolt 78, the ejector pin 77 and the guide. The ejector plate 80 is slidably connected to the core block assembly 69 via the pin 85, and the ejector plate 80 moves toward the core block assembly 69 by the rotation of the connection bolt 78. Therefore, only by rotating the connecting bolt 78, the screw shaft portion can be removed from the screw hole of the ejector rod 82 to release the screwed state of the both.

Next, the mounting screw 68 fixing the core block assembly 69 of the core block unit to the movable side receiving plate 63 is loosened, and this mounting screw 68 is removed together with the disc spring 71. As a result, the tightening force of the core block assembly 69 is released and becomes free. Therefore, by pulling out the core block assembly 69 along the knock pin 70, the core block unit is easily removed from the movable side receiving plate 63. 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 the core plate 60 is repaired or modified, the core block assembly 69 is pulled out from the ejector plate 80 to separate the core block unit into the core block assembly 69 and the ejector plate 80. As a result, the core block 61 can be repaired or modified in units of the core block assembly 69.

Therefore, also for the core block 61, as in the case of the cavity block 46, the movable side receiving plate 6 is provided.
It is very easy to remove from 3. Moreover, the ejector plate 80 can be separated from the core block assembly 69 only by pulling it out, and the core block assembly 69 is not connected to other parts such as the movable side mounting plate as in the conventional case. Core block assembly 69
Since it can be handled as a unit, it is possible to proceed to the repair / remodeling work as it is, and it is possible to improve the work efficiency of the repair / remodeling etc. by enabling a quick work.

When the work of repairing or modifying the core block assembly 69 is completed, the ejector plate 8 is
The 0 side is combined to form a core block unit.
In this case, the tip of the connecting bolt 78 standing on the ejector plate 80 is installed in the bolt hole of the core block assembly 69, and the ejector pin 77 standing on the ejector plate 80 is installed in the pin hole of the core block assembly 69. Tip
Further, the tips of the guide pins 85 provided upright on the core block assembly 69 are respectively aligned with the holes of the guide pin bushes 84 fitted into the bush holes 83 of the ejector plate 80, and these are pushed in to push the core block assembly. The core block unit is configured by combining 69 and the ejector plate 80.

On the other hand, when attaching the core block unit to the movable side receiving plate 63, first, the ejector plate 80 of the core block unit is aligned with the concave portion 81 of the movable side receiving plate 63, and the core block assembly 6 is placed.
The back side of the pin hole 69a of 9 is aligned with the knock pin 70 planted in the movable side receiving plate 63. Next, while inserting the ejector plate 80 into the concave portion 81,
The core block assembly 69 is pushed along the knock pin 70. Then, the disc spring 71 is inserted into the counterbore hole 69b of the core block assembly 69, the shaft portion of the mounting screw 68 is inserted through the hole of the disc spring 71 and the hole of the knock pin 70, and the screw shaft portion at the tip is inserted. The movable side receiving plate 63 is screwed into the screw hole and fixed by tightening.

Next, the connecting bolt 78 is turned to the tightening side and screwed into the screw hole of the ejector rod 82, and the connecting bolt 7
By tightening 8, the ejector plate 80 is connected and fixed to the ejector rod 82. As a result, the core block unit is fixed to the movable side receiving plate 63. Therefore, the work of mounting the core block unit can be easily and quickly executed.

Next, the mold matching of the cavity block 46 and the core block 61 will be described. As shown in FIG. 4, when the core block 61 is brought close to the cavity block 46 by operating the injection molding machine and moving the movable platen 23, the positioning bush 72 attached to the core block 61 is attached to the cavity block 46. As the positioning pin 56 is approached, the protrusion 56b thereof enters into the positioning hole 72a of the positioning bush 72.

In this case, as shown in FIG. 3, the core block assembly 69 of the core block unit is fixed by the mounting screw 68 via the disc spring 71, and the spring force of the disc spring 71 is the core block unit. Is set so as not to shift due to its own weight. Moreover, the knock pin 70 whose base portion is press-fitted into the movable side receiving plate 63 for attaching and detaching the core block unit is formed such that the outer diameter thereof is larger than the pin hole 69a of the core block assembly 69 and a slight gap is set. There is. Therefore, the core block assembly 69
Is an external force acting in the direction of the parting surface 79,
Since the disc spring 71 is interposed, the disc spring 71 has a degree of freedom that allows the disc spring 71 to move slightly in the plane direction.

Therefore, since the positioning pin 56 of the block positioning mechanism 55 for positioning between the cavity block 46 and the core block 61 and the positioning bush 72 do not coincide with each other, the protrusion 56b is formed in the positioning hole 72a.
Even if a force in the direction of the parting surface 79 is generated in the core block assembly 69 by inserting the core block assembly 69 into the core block assembly 69, the core block assembly 69 moves following the cavity block 46 so as to reduce the force. Therefore,
When the mold is closed, the cavity block 46 and the core block 61 can always be precisely positioned at a predetermined position and the mold can be closed. Therefore, it is possible to manufacture a molded product with little burr or no burr without the risk of manufacturing a molded product in a state where the mold is displaced.

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 4 is moved forward, the protruding rod 94 abuts against the ejector block 92 and pushes it out, and the protruding plate 88 connected to the ejector block 92 is advanced against the biasing force of the return spring 95. As a result, the ejector rod 82, the base of which is fixed to the protruding plate 88, moves forward, and the connecting bolt 78 connected to the ejector rod 82 and the ejector plate 80 integral with the connecting bolt 78 are guided by the guide pin 85 to move forward. As a result, the ejector plate 80 is moved forward to eject the ejector pin 77.
Project from the core plate 60, and the ejector pin 7
The molded product attached to the core block 61 is peeled off and ejected by 7.

Next, when the projecting rod 94 is retracted, the pressing force of the ejector block 92 is released, so that the projecting plate 88 and the ejector rod 82 are retracted by the urging force of the return spring 95, and together with this, the ejector rod 8 is released.
The ejector plate 80 is retracted by being pulled by 2. Therefore, the ejector pin 77 and the connecting bolt 78 are pulled back into the core block assembly 69, which enables the mold closing with the cavity block 46.

As a result, the injection molding machine is operated as described above, the movable side mold 41 is aligned with the fixed side mold 42 and the mold is closed, and the preparation for the next injection molding is completed.

As described above, the present invention is not limited to the above-described embodiment, and 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 is used. Can
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. As a structural example of a mold for injection molding, a cold runner type mold has been described in the above embodiment, but it can be applied to a hot runner type or a semi-hot runner type mold.

Further, in the above 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 in order to secure the degree of freedom of the movable-side die 41, the movable-side die 4 is attached by a mounting screw 68 via a disc spring 71.
The example in which 1 is tightened and fixed has been described, but
In contrast to this, the movable side mold 41 may be provided with a positioning mechanism, and the fixed side mold 42 may be provided with a disc spring 71 or the like for ensuring the degree of freedom. Then, as an example of the elastic member 71, the example in which the disc spring 71 is applied has been described, but other types of springs (for example, coil springs, spring washers, etc.) as well as rubber-like elastic bodies and the like are applied. You can also

Further, although the example applied to a tape cassette such as a compact cassette or a video cassette as a molded product has been described, the present invention is not limited to the tape cassette and various casings such as a compact disk cartridge and a floppy disk cartridge can be used. Of course, it can be used as an injection molding die for manufacturing various molded products other than the housing. Thus, the present invention can be variously modified without departing from the spirit thereof.

[0069]

As described above, according to the present invention,
With the mold for injection molding attached to the injection molding machine, the cavity block of the movable side mold or the core block of the fixed side mold can be attached and detached from the parting surface, making installation and removal work extremely easy and quick. It is possible to provide an injection molding die that can be performed and can significantly reduce the time required for maintenance and repair. In addition, the mold can be exchanged by replacing the cavity block and core block units, and the types of molded products can be easily switched. Moreover, one mold can simultaneously mold multiple types of molded products. Therefore, it is possible to provide an injection molding die that can be used for production of different production types (for example, small-lot production of various types and large-scale production of small types).

Further, since one of the cavity block and the core block unit is provided with a highly accurate positioning mechanism so that the other block can move following the one block, one of the reference blocks is displaced. Even if it is attached, since the other block moves so as to follow, the mold matching is performed,
It is possible to prevent the cavity block and the core block from being damaged by the displacement of the mold.

[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 sectional view showing a main part of the injection molding die shown in FIG.

FIG. 4 is an enlarged cross-sectional view showing a cavity block and a core block unit of the injection molding die shown in FIG.

FIG. 5 is a cross-sectional view showing a conventional injection molding die.

FIG. 6 is a block diagram for explaining a general work of replacing a mold for injection molding.

[Explanation of symbols]

 40 Injection Mold 41 Movable Side Mold 42 Fixed Side Mold 46 Cavity Block 49 Mounting Screw 50 Knock Pin 55 Block Positioning Mechanism 56 Positioning Pin 60 Core Plate 61 Core Block 63 Movable Side Support Plate 68 Mounting Screw (Fixing Means) 69 Core Block Assembly 70 Knock pin 71 Disc spring (elastic member) 72 Positioning bush 78 Connection bolt 79 Parting surface 80 Ejector plate 81 Recessed portion 82 Ejector rod 88 Projection plate 90 Guide screw

Claims (4)

[Claims] 1. A fixed side mold having a cavity block forming an outer surface of a molded product and a movable side mold having a core block forming an inner surface of the molded product, wherein the fixed side mold and the movable side mold are provided. In the injection-molding mold that is detachable on the parting surface, at least one of the fixed-side mold and the movable-side mold is
A fixed side positioning mechanism for positioning between the cavity block and the fixed side mold member or a movable side positioning mechanism for positioning between the core block and the movable side mold side is provided, and the positioning mechanism is provided. The cavity block or the core block is removably fixed to the fixed-side mold member or the movable-side mold member from the parting surface side by a fixing means. . 2. The injection-molding die according to claim 1, wherein the movable side mold protrudes the molded product molded in a cavity formed by the cavity block and the core block from the core block. An injection-molding die, comprising: a core-side projecting mechanism for peeling; and a main projecting mechanism that is detachably connected to the core-side projecting mechanism to operate the core-side projecting mechanism. 3. The injection molding die according to claim 1, wherein an elastic member is interposed between the core block of the movable side mold and the fixing means, and the core is generated by a spring force of the elastic member. An injection mold, wherein the block is clamped and fixed to a member on the movable side of the mold. 4. The injection molding die according to claim 1, wherein a block positioning mechanism for positioning both blocks is provided on the cavity block of the fixed side mold and the core block of the movable side mold. A mold for injection molding, which is characterized in that