JPH0852765A - Cassette type injection mold apparatus - Google Patents

Abstract

PURPOSE:To simplify the constitution in order to reduce the cost of an injection molded product in the cassette type injection mold apparatus. CONSTITUTION:The pin tip part of one of a plurality of runner lock pins 10, 11 is positioned at the runner part 5c formed to the anti-cavity surface 5b of the cassette mold 5 mounted on the base plate 4 of a fixed mold P. The runner lock pins 10, 11 are energized by a compression spring 12 and the pin tip part of the other pin is in elastic contact with the anti-cavity surface 5b of the cassette mold 5. At the time of the replacement with a cassette mold having a different runner part, the runner part crosses the pin tip part of the other runner lock pin and the pin tip part protrudes into the runner part to lock a runner. The pin tip part of one runner lock pin becomes the elastic contact state with the anti-cavity surface 5b. As a result, it becomes unnecessary to provide an escape hole allowing the pin tip part of a preparatory runner lock pin to escape toward the cassette mold and, therefore, the production cost of the cassette mold can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cassette type injection molding die device.

[0002]

2. Description of the Related Art Since a mold apparatus has a high specific gravity in the cost of an injection molded product, a so-called cassette type in which only a mold having a different cavity for each different molded product is replaced as a means for cost reduction. An injection mold device is used (for example, Japanese Utility Model Publication No. Sho 58-4210).
No. 0). The cassette type injection molding die device has a basic configuration in which a detachable cassette die is attached to each of a fixed side die and a movable side die. The feature of this device is that when you try to mold different molded products, you only have to convert it to a cassette mold that has a cavity corresponding to it, and the base mold is always attached to the molding machine body It has excellent economic efficiency because it can be used in common. Further, the automation of the cassette die replacement has been advanced, and since it has become possible to switch the molded product with almost no manpower, the cost of the injection molded product can be reduced.

As shown in FIG. 3, in the fixed side mold P, a sprue bush 37 fitted with a nozzle of a molding machine main body and supplied with molten resin includes a fixed side mounting plate 31 and a runner projecting plate 32. The sprue 37a is provided so as to penetrate therethrough, and the tip of the sprue 37a is configured to be able to supply the resin to the cavity via the runner portion 35c and the sub-runner portion 35d that vertically cuts the cassette mold 35. A gate portion 35e is provided at the tip of the sub-runner portion 35d.

In the runner portion 35c, the resin of the gate portion 35e is cut when the die is opened, and the fixed side base plate 34 and the cassette die 35 are attached to the spacer plate 33.
A runner lock pin 40 for supporting the resin runner and the sub-runner on the runner portion 35c when being separated from is provided, and the runner lock pin 40 allows the resin runner and the sub-runner to remain in the stationary mold. .

The runner lock pin 40 has a rear end portion 40b.
Are fixed by a fixed side mounting plate 31 and a sprue bush 37, and runner projecting plate 32 and spacer plate 33 pass through an insertion hole provided in mounting plate 31.
And the tip portion 40a projects to the front surface side of the spacer plate. The tip end portion 40a of the runner lock pin is formed with a tapered projection portion having a thick tip end so that the solidified runner resin does not come off during mold opening.

Here, in order for the runner lock pin 40 to perform the above-mentioned function, the tip end portion 40a must be arranged so as to intersect the runner portion 35c formed on the anti-cavity surface 35b of the cassette mold 35. I have to. However, the runner lock pin 40 is always the same one even if the cassette mold 35 is replaced, and it is impossible to change its position as long as the same mold is used. When manufacturing the mold, always set the position of the runner 35c to the tip 4 of the runner lock pin.
There is a constraint that it must be provided so as to intersect with 0a. Therefore, depending on the shape of the cavity provided in the cassette mold, there may be a case where the tip of the specific runner lock pin cannot be crossed. Therefore, as a countermeasure against this, normally, a plurality of spare runner lock pins 41 are provided, and the tip end portion 41a of one of the runner lock pins intersects the runner portion 35c, and the remaining runner lock pins do not function. I am allowed to do so. However, the rear end of the runner lock pin is fixed to the fixed side receiving plate 31, and the tip 41a of the runner lock pin projects to the front surface of the spacer plate 34. Therefore, the presence of the tip 41a interferes when the cassette mold is mounted. become. Therefore, in order to escape the front end portion 41a, an escape hole portion 35e for accommodating the front end portion 41a is provided at the rear end portion of the cassette mold 35.

[0007]

As described above, all the cassette molds to be replaced are provided with an escape hole for accommodating the tip portion of the runner lock pin, which is unnecessary for the cassette molds. Processing becomes complicated,
This is a cause of increasing the manufacturing cost of injection molded products.

Therefore, an object of the present invention is to reduce the cost of an injection-molded product by eliminating the need to form an escape hole in a cassette mold for accommodating the tip of a runner lock pin.

[0009]

To achieve the above object, the present invention comprises a fixed side mold and a movable side mold, and both molds have different cavities for molding different molded products. In a cassette-type injection molding die apparatus in which one or more sets of cassette dies are replaceably attached to the cassette dies, a fixed-side die is provided with a plurality of runner lock pins at positions where the cassette dies are attached. , At least one of the plurality of runner lock pins is provided so that the pin tip portion can intersect the runner portion provided on the anti-cavity surface of the cassette mold, and each runner lock pin is
Runners that are slidably supported in the mounting direction of the cassette mold and are biased by the biasing members to the anti-cavity surface of the cassette mold, and intersect the runner section when the mold is closed. The lock pin is characterized in that the tip end portion is located in the runner portion, and the runner lock pin that does not intersect the runner portion is provided so as to be retracted against the biasing member by being pushed by the cassette mold.

[0010]

[Function] Since the plurality of runner lock pins provided so as to correspond to each cassette mold are biased forward by the biasing members, the runner lock pins are located at positions intersecting the runner portion of the cassette mold. Has a tip portion located in the runner portion. The tip of the runner lock pin that does not intersect with the runner part retreats against the biasing force of the biasing member,
It is in elastic contact with the anti-cavity surface of the cassette mold.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows the overall construction of an embodiment to which the present invention is applied. Further, FIG. 2 is an enlarged view of a main part of FIG. 1, and shows the one in which the present invention is applied at the same position as a part of the fixed side mold shown in the description of the prior art (see FIG. 3). ing.

As shown in FIG. 1, a cassette type injection molding die apparatus according to the present invention comprises a fixed side die P and a movable side die Q, and each time a molded product is formed in each die. A plurality of cassette molds having different cavities are replaceably mounted.

As shown in FIGS. 1 and 2, the fixed mold P is
Fixed side mounting plate 1 mounted on the molding machine body (not shown)
The runner projecting plate 2 is provided on the front surface (left side) and the spacer plate 3 is provided on the front surface. A fixed-side base plate 4 is provided on the front surface of the spacer plate 3, and the four storage recesses 4 provided on this base plate.
A cassette mold 5 is attached to each a.

The cassette mold 5 is provided at its front end with a brim portion 5a formed in a wide brim shape so that the back surface of the brim portion abuts on the front surface of the fixed side base plate 4 so that it does not enter further. is there.

A fixed key 6 is provided at the rear end portion of the cassette mold 5, that is, the engaging portions formed on both sides of the anti-cavity surface 5b.
The engaging portions of the cassette die are engaged with each other, so that the cassette mold 5 cannot be removed from the storage recess 4a of the fixed-side base plate 4. A runner portion 5c is formed on the anti-cavity surface 5b of the cassette mold. The front end portion of the runner portion 5c intersects with the rear end portion of the sub-runner portion 5d formed of a tapered hole provided so as to vertically cut the cassette mold. A gate portion 5e is provided at the tip of the sub-runner portion 5d.

A sprue bush 7 is fitted in the central portion of the fixed-side mounting plate 1, and this sprue bush penetrates the runner projecting plate 2 and the tip thereof is the runner projecting plate 2.
It is flush with the front of the. The sprue bush 7 is fixed to the fixed side mounting plate 1 by a locate ring 8. The sprue bush 7 is provided on the tip end side thereof with a sprue 7a having a tapered hole with a large front portion.

A recess 3a for a runner plate is provided in the center of the spacer plate 3, and this recess has
The runner plate 9 fixed to the central portion of the back surface of the fixed-side base plate 4 is located. Runner plate 9
Is formed between the runner plate and the receiving plate 3 at the center position of the groove formed on the back surface intersecting with the sprue 7a in a T shape, and bifurcated in two directions at the tips of the grooves extending on both sides. It communicates with a runner portion 5c formed on the anti-cavity surface 5b of the cassette mold via a passage.

The runner section 5c is provided with two runner lock pins 10 and 1 for each cassette mold.
One pin tip portion 10a of 1 (two in this embodiment for the sake of explanation; a large number can be considered as other embodiments) is located. The pin tip portion 10a of the runner lock pin 10 is located on the extension of the sub-runner portion 5d so that the resin sub-runner can be easily removed from the cassette mold 5 when the mold is opened.

Two runner lock pins 10 and 11 are provided for each cassette mold, and flanges 10b and 11b are retractably housed in holes 1a and 1a provided in the fixed side mounting plate 1. There is. Flange parts 10b, 11b
The sliding portion extending forward from is slidably supported by through holes provided in the fixed side mounting plate 1, the runner protruding plate 2 and the spacer plate 3. Behind the two runner lock pins are compression springs 12, which are biasing members,
12 are provided. Each compression spring 12 is housed in a compressed state by a stopper 13, 13 screwed to the opening of the hole 1a provided at the rear end of the mounting plate. By thus biasing the runner lock pins 10 and 11 toward the anti-cavity surface 5b, the spacer plates 3 can be projected forward.

The runner lock pins 10 and 11 restrict the amount of protrusion of the pin tip portions 10a and 11a into the runner portion 5c by restricting the forward movement by the flange portions 10b and 11b. The pin tip end portion 10a of one runner lock is arranged so as to intersect the runner portion 5c, while the pin tip end portion 11a of the other runner lock pin is arranged opposite the cavity surface 5b of the cassette mold 5.
Is in contact with In this way, one runner lock pin 10 projects into the runner, while the other runner lock pin 10 retracts by that amount, but this retraction causes the compression spring 12 to be compressed. Therefore, it is not necessary to provide a relief hole for the spare runner lock pin as in the prior art.

The movable die Q is a front surface (right side in the drawing) of a movable mounting plate 14 fixed to a cylinder block (not shown).
Is provided with a spacer block 15, and a movable side receiving plate 16 is provided on the front surface thereof. A movable base plate 17 is provided on the front surface of the movable support plate 16. The movable base plate 17 is provided with a storage recess 17a for the cassette mold 18, and each cassette mold is fixed to the movable base plate 17 by a fixed key 19 so as not to fall off.

A first projecting plate 21 is provided in the space formed in the spacer block 15 so as to be movable back and forth.
A plurality of first protruding pins 22 are fixed to this. The first projecting pins 22 can project to the front surface of the movable side receiving plate 16 through the insertion holes provided in the movable side receiving plate 16, respectively.

A second projecting mechanism 23 is provided on each movable cassette mold 18. The second projecting mechanism 23 includes a second projecting plate 24 and a plurality of second projecting pins 25 fixed to the second projecting plate 24. These second projecting pins 25 can project into the cavity 18b and the parting line surface through the insertion holes provided in the template 18a. The second projecting mechanism 23 is the first projecting mechanism 20.
When moves forward, it moves forward accordingly and is in a protruding state. When the cylinder in which the first protrusion mechanism 20 has advanced moves backward, the first protrusion mechanism 20 returns to its original position by a return spring (not shown). According to this, the second
The projecting mechanism 23 can also be returned to its original position by a return spring (not shown).

The fixed-side mold P is provided with a pair of support shafts 26 and guide shafts 27, and the movable-side mold Q can be moved forward and backward by these shafts.

Next, the operation will be described.

When the movable side mold Q advances along the support shaft 26 and the guide shaft 27 and enters the mold closing process, the movable side cassette mold 18 and the fixed side cassette mold 5 come into contact with each other and the parting line. A cavity is formed on the surface. Next, the resin is supplied from the sprue 7a to the cavity via the runner portion 5c. When the movable side mold Q is retracted after the predetermined curing time is taken, the molded product solidified in the cavity retracts together with the movable side mold. At this time, the molded product and the resin runner are cut at the gate 5e. Furthermore, in the process in which the movable mold Q retracts,
The second protruding mechanism 23 ejects the molded product left in the cavity 18b and collects it. In parallel with this, the stationary side base plate 4 is moved forward by a mold opening mechanism (not shown). Along with this, the fixed-side cassette mold 5 and the runner plate 9 also move forward, so that the resin runner fixed by the runner portion 5c also tries to move forward, but due to the pin tip portion 10a of the runner lock pin 10. It is prevented from moving and remains on the front surface of the spacer plate 3.

Next, when the spacer plate 3 is moved forward, the resin runner separates from the tip of the molding machine nozzle in the semi-contact state and drops. When the cassette die 5 moves forward together with the fixed side base plate 4, the other runner lock pin 11 is released, so that the pin tip portion 10a thereof is released.
Protrudes to the same position as one lock pin 10. Next, in the mold closing process again, the other lock pin 11 is retracted by the cassette mold 5 and returns to the original state.

Next, when the cassette mold 5 formed so that the position of the runner portion 5c is different is mounted, the pin tip portion 1 of the runner portion and the other runner lock pin 11 is mounted.
1b intersects each other, and one of the lock pins 10 is in a state in which the front end thereof is in contact with the rear end of the cassette mold 5. The operation is the same as in the case described above, and thus the description is omitted.

The present invention can be applied to various cassette type injection molding die devices other than the structure shown in this embodiment.

[0031]

According to the present invention, since the runner lock pin can be retracted by the biasing member, the tip end of the lock pin that does not intersect the runner portion is retracted by the rear end of the cassette mold, so that the cassette mold It is not necessary to provide an escape hole at the rear end. Therefore, it is possible to reduce the number of processing steps of the cassette mold used in large numbers, and thus it is possible to reduce the cost of the injection molded product. In addition, due to the reduction in man-hours, it is possible to shorten the construction period of the cassette mold.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part of an embodiment of the present invention.

FIG. 2 is an enlarged view of part A in FIG.

FIG. 3 is a cross-sectional view of a main part of a conventional technique.

[Explanation of symbols]

 P Fixed-side mold Q Movable-side mold 4 Fixed-side base plate 5 Fixed-side cassette mold 5b Anti-cavity surface 5c Runner part 10,11 Runner lock pin 10a, 11a Pin tip part 12 Energizing member

Claims (1)

[Claims] 1. A fixed mold and a movable mold, wherein at least one set of cassette molds is replaceable with a cassette mold having different cavities for molding different molded products. In the installed cassette type injection molding die device, a plurality of runner lock pins are provided at a position where the cassette die is mounted on the fixed side die, and at least one of the plurality of runner lock pins is provided. The pin tip is provided so as to intersect the runner portion provided on the anti-cavity surface of the cassette mold, and each of the runner lock pins is rotatably supported in the mounting direction of the cassette mold. The runner lock pin, which is urged by the urging member to the anti-cavity surface of the cassette mold and intersects the runner part when the mold is closed, has a tip part. The cassette type injection molding die device, wherein the runner lock pin located in the runner portion and not intersecting with the runner portion is pushed by the cassette die and can retreat against the biasing member. .