JPS61249720A - Mold for injection molding - Google Patents

Abstract

PURPOSE:To contrive to simplify a mold and to improve injection molding efficiency, enabling the cleaning, repair or replacement of the mold to be achieved by removing only a main mold by a method in which a gate is provided between a runner and a cavity, and a clamping plate is fitted to the outer periphery of the empty chamber into which the main mold is inserted, thereby fixing the main mold undetachably. CONSTITUTION:The clamping plate 9 inhibitting the detachment of a main mold 5 has the connecting part 39 connected to the fixing part 51 provided at the periphery of the main mold 5 in the front part, and is fixed to a stop part 33 provided at the periphery of the empty chamber into which the main mold 5 is inserted, whereby the main mold 5 having been inserted into the empty chamber, is fixed to the pedestal mold I. During injection molding, when the defect in the mold occurs or the cleaning of the mold becomes necessary, only the defective main mold 5 is removed from the empty chamber of the pedestal mold I, leaving the pedestal mold I as it is, or only the main mold 5 having the necessity of cleaning is removed and another main mold 5 is fitted instead of said main mold, and then molding is continued again. In said period, the main mold 5 is repaired or cleaned.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] This invention relates to an injection mold used for manufacturing synthetic resin products. . ,.

[Technical background of the invention and its problems]

Conventional injection molds have an upper mold/mold (generally a female mold) attached to a fixed plate on the main wheel heating cylinder side, and a movable plate on the mold clamping side that reciprocates toward the upper mold. It consists of a lower mold (generally a male mold), a clasp, a parting line at the 9th seam between the mold and the lower mold, forming a key to form the target molded product, and an upper mold. A sprue connected to the cylinder nozzle is installed in the mold, a runner is installed on the sprue, and a gate is installed between the runner and the cavity, and the resin injected into the cavity is cooled to a temperature close to the mold temperature. After curing, the lower mold is separated from the upper mold by retreating, and the ejector plate of the lower mold is pushed forward with a ram, and the molded product attached to the lower mold is ejected outward with the ejector pin provided on the ejector plate. was. In addition, a multi-cavity mold is also used for injection molding, in which a set of molds has multiple cavities, a runner is installed close to each cavity from the sprue, and a gate is provided from the runner to each cavity. has been done.

Regardless of the type of injection mold, the mold becomes dirty and worn out in proportion to the number of injections, and failures also occur. At that time, the mold had to be cleaned or repaired while attached to the injection machine, or the mold had to be removed from the injection machine, disassembled, and cleaned or repaired and replaced. However, when cleaning or repairing the mold while it is attached to the injection machine, there is a disadvantage that the injection machine must be stopped during that time, and when the mold is removed from the injection machine for repairs, etc., the repair cannot be performed. There was an inconvenience in that the injection machine had to be stopped until the molding process was completed, or another mold had to be attached to perform the molding.

[Purpose of the invention]

Therefore, this invention consists of an injection mold consisting of a base mold consisting of a fixed base mold and a movable base mold, and a main mold that can be attached to and detached from the base mold, so that only the main mold can be removed for cleaning, repair or replacement. The purpose of this invention is to simplify mold molding and improve injection molding efficiency.

[Summary of the invention]

The injection mold of the present invention has at least two or more empty chambers at the separation line between a fixed base mold having a sprue and a movable base mold having a rear plate that moves back and forth in the mold clamping direction. It consists of an alloy mold whose chamber is perpendicular to the mold clamping direction, a main mold that is inserted into the empty space of the platinum mold, and a fixing plate that fixes the main mold in the empty space. The fixed base mold and the movable base mold of the mold can be moved back and forth by the guide pin, and the base plate of the alloy mold has a base return pin that penetrates the movable base mold and comes into contact with the fixed base mold, an extrusion pin that reaches the empty chamber, and a sprue lock. The main mold is equipped with pins and installed in an empty space, and consists of a fixed mold that is installed on a fixed base mold, and a movable mold that is installed on a movable base mold. A plate is provided at the rear of the movable mold, which forms a cavity and is movable back and forth, equipped with a return pin that penetrates the movable mold and contacts the fixed mold, and a protruding pin that reaches the cavity. A runner is installed close to the cavity of the main mold, and a gate is installed between the runner and the opening, and a fixing plate is installed on the outer circumference of the empty space into which the main mold is inserted, fixing the main mold so that it cannot be removed. It is something to do.

[Embodiments of the invention]

Below, the structure of the injection mold according to the present invention will be explained based on the drawings of the embodiments.
It is an alloy type consisting of a fixed base mold 1 that is attached to the mold clamping ram C, and a movable base mold 2 that is attached to the movable platen of the mold clamping ram C. The fixed base mold 1 has a sprue S in the center and is inserted into the movable base mold 2 on the outer periphery. A guide pin 12 is provided to fix the fixed base □ type 1 by the guide pin 12.
The movable platform mold 2, which reciprocates toward the fixed platform mold 1, is guided so as to precisely match the fixed platform mold 1. 3- is a vacant space provided at the separation line between the fixed platform mold 1 and the movable platform mold 2, and two or more vacant chambers 3 are provided evenly, and each vacant chamber 3 is It opens toward the outer periphery so as to form a right angle, and has a protrusion 31 forming a chevron toward the outer periphery at the deep part of the cavity 3, that is, the abutment surface 30 on the inner peripheral side of the cavity 3. 3 vacant rooms to 2
In the case of the alloy type ■ with a chamber, the empty chambers 3°3 are provided vertically or horizontally symmetrically around the sprue S4, and in the alloy type ■ with three empty chambers 3, with the sprue S as the center. te12
In alloy type I, in which the cavities 3 are provided in the radial direction at intervals of 0 degrees, and four cavities 3 are provided, the cavities 3 are provided symmetrically vertically and horizontally with the sprue S as the center. All vacant rooms 3 are fixed platform type 1
The raised portion 31 provided on the abutting surface 30 of the empty chamber 3 is also provided astride both the platform molds 1 and 2. The movable table mold 2 constituting the table mold ■ is equipped with a table hem 21 on the outer periphery of the rear part, or a spacer that becomes the table hem 21 on the rear outer part, and a table that reaches the outer periphery of the vacant room 3 at the center of the rear part. A plate loose fitting part 20 is formed, a mounting plate 22 is fixed to the rear of the base base part 21, and the loose fitting part 20 is formed in the center of the mounting plate 22.
A through hole 23 is provided in communication with the movable base mold 2, and the base plate is guided in the mold clamping direction by a support 40 that protrudes rearward from the movable base mold 2 in the base plate loose fitting part 20, and a guide pin 44 that is inserted into the movable base mold 2 from the mounting plate 22. A base plate 4 is provided, and the base plate 4 includes a sprue lock pin 41 that reaches the sprue S, a base return pin 42 that penetrates the movable base mold 2 and comes into contact with the fixed base mold 1, and an extrusion pin that reaches the empty space 3. 43, and these pins 41, 42, 43, 44 and the support 40 enable the base plate 4 to slide back and forth in the mold clamping direction,
The base plate 4 is retracted to the mounting plate 22 in the mold clamping state by the base return pin 44 that comes into contact with the fixed base mold 1, and the extrusion pin 43 protrudes into the empty space 3 as the base plate 4 that has been retreated moves forward. The head of the table return pin 42 protrudes forward from the movable table mold 2. Reference numeral 5 denotes a main mold to be installed in the empty space 3 of the base mold 1, and the main mold 5 includes a fixed mold 6 to be installed to the fixed base mold 1 of the base mold ■, and a movable mold 7 to be installed to the movable base mold 2. The separation line of the joint between the front and rear molds 6 and 7 is provided so as to coincide with the separation line of the base mold (■), and the cavity 15 of the product P is formed at the separation line of the main mold 5, The insertion side of the mold 5 has an inclined recess 50 corresponding to the protrusion 31 provided in the inner part of the empty chamber 3, and the locking part 5 is provided on the outer circumferential side.
1. The movable mold 7 of the main mold 5 is provided with a hem 71 on the outer periphery of the rear part, or a spacer that becomes the hem 71 is attached,
A plate loose fitting part 70 is provided in the center of the rear part that reaches at least the formation range of the cavity 15, and a plate 8 is provided in the plate loose fitting part 70 to be guided in the mold clamping direction by a support 80 that projects rearward from the movable mold 7. A return pin 82 passes through the movable mold 7 on the plate 8 and comes into contact with the fixed mold 6.
and a protruding pin 83 that reaches the cavity 15,
Both pins 82 and 83 and the support 80 allow the plate 8 to slide back and forth in the mold clamping direction, and the return pin 82 in contact with the fixed mold 6 allows the plate 8 to move rearward of the plate loose fitting part 70 in the mold clamping state. As the plate 8 moves forward, the projecting pin 83 projects into the cavity 15, and the head of the return pin 82 projects forward from the movable mold 7. After the mold is opened, the base plate 4 provided on the base plate loose fitting part 20 of the movable base mold 2 is moved forward by a ram C that is pushed forward from the fixed platen B on which the movable base mold 2 is attached, that is, the ram C is attached to the mounting plate. 22 through the through-holes 23 to reach the base plate loose fitting part 20, contact the base plate 4 which is retreating in the base plate loose fit part 20, and slide the base plate 4 forward in the mold clamping direction, Each pin 41, 42, 43 provided on the base plate 4 projects forward. As for the plate 8 provided in the plate loose fitting part 70 of the movable mold 7, the base plate 4 of the movable mold 2 is advanced by the ram C, and the extrusion pin 43 provided on the base plate 4 protrudes into the empty chamber 3. In other words, the extrusion pin 43 of the movable mold 2 protrudes toward the plate loose fitting part 70 of the movable mold 7 attached to the empty chamber 3, and comes into contact with the receding plate 8 in the plate loose fitting part 70. , the plate 8 is slid forward in the mold clamping direction, and each pin 82, 83 provided on the plate 8 is projected forward.
10 is a spring that presses the base plate 4 of the base mold ■ and the plate 8 of the main mold 5 in the backward direction, and 9 is a fixing element that makes the main mold 5 inserted into the empty space 3 of the base mold I irremovable. The fixed plate 9 consists of a front fixing plate 19 that draws and fixes the fixed mold 6 to the fixed base mold 1, and a rear fixing plate 29 that draws and fixes the movable mold 6 to the movable base mold 2. 9 has an engaging part 39 on the front part that engages with the engaging part 51 provided on the outer periphery of the main mold 5, and a bolt is attached to the stopping part 33 provided on the outer periphery of the empty chamber 3 into which the main mold 5 is inserted. A fixed pressure is applied at 35, and the main mold 5 inserted into the empty chamber 3 is fixed to the base mold ■. 25 is a heat insulating plate attached in front of the fixed base mold 1 and after the movable base mold mounting plate 22, and 11 is a cooling water channel provided in the base mold I for mold cooling.

Since the injection mold of the present invention has the above-mentioned structure, there is one set of the base mold (■) in which several empty spaces 3 are provided in advance, and several sets that can be installed in the empty spaces 3 of the base mold (■). A fixing plate 9 is formed to irremovably fix the main mold 5 and the main mold 5 inserted into the empty chamber 3.・When installing the mold of the present invention on an injection machine,
First, fixing plate type 1 of alloy type I is fixed plate B of heating cylinder.
Attach the movable base mold 2 to the movable platen of the mold clamping ram C, then insert the main mold 5 from the outer periphery into the empty space 3 of the base mold ■, and insert the fixed plate 9 into the rear part of the main mold 5. First, the main mold 5 is installed in the empty chamber 3 of the alloy type I, and then the base mold I is installed on the cylinder fixed platen B and the ram movable platen.

The main mold 5 attached to the empty chamber 3 of the base mold I is inserted into the empty chamber 3 of the base mold ■, so it cannot be removed from the inner circumference in the center direction and to the left or right in the insertion direction. At the same time, the fixing plate 9 attached to the rear part of the main mold 5 makes it impossible to separate in the outer circumferential direction, and the raised part 31 provided on the abutment surface 30 of the empty chamber 3 and the main mold abutted against the raised part 31 5, and a locking portion 51 provided on the outer periphery of the main mold 5;
The fixed mold 6 of the main mold 5 is pulled and fixed to the fixed base mold 1 by the fixed plate 9 that is engaged with the movable mold 7.
The fixed mold 6 of the main mold 5 constitutes a part of the fixed base mold 1, and the movable mold 7 constitutes a part of the movable base mold 2.

When the mold of the present invention installed in the injection machine as described above is clamped,
The base plate 4 is inserted into the base plate loose fitting portion 20 of the movable base mold 2 by the base return pin 42 that comes into contact with the fixed base mold 1.
is retracted, and the extrusion pin 4 is moved by the retracted base plate 4.
3 is inserted into the movable platform mold 2 from the empty room 3. The plate 8 of the main mold 5 installed in the empty chamber 3 is retracted by the return pin 82 that comes into contact with the fixed mold 6, and the retracted plate 8
The protruding pin 83 moves from the cavity 15 to the movable mold 7.
Immerse yourself inside. By clamping, the separation line of the base mold ■ and the separation line of the main mold 5 installed in the empty chamber 3 of the base mold I are aligned, and the sprue S provided in the base mold I and the cavity of the main mold 5 are aligned. 15 communicates with the runner R via the gate G.

In this mold clamping state, from sprue S to runner R and gate G.
The molten resin is injected into the cavity 15 through the hole, and when the resin has cooled and hardened appropriately in the cavity 15, the base mold I is
When the mold is opened, that is, the movable base mold 2 is moved back, the fixed mold 6 of the main mold 5 is attached to the fixed base mold 1, and the movable mold 7 is attached to the movable base mold 2, so that the main mold 5 is attached to the movable base mold 2. The movable mold 7 of the mold 5 is retreated from the fixed mold 6 together with the movable mold 2.

After opening the mold, if the mold clamping ram C is advanced and the base plate 4 is pushed out to be inserted into the base plate loose fitting part 20 of the movable base mold 2, the base return pin 42 and the sprue lock pin 4 are attached to the base plate 4.
1. and an extrusion pin 43, these pins 41, 42, 43 slide forward and protrude as the base plate 4 is extruded. Among them, sprue lock pin 4
1 extrudes the resin part formed on the sprue S to the outside of the mold, and the extrusion pin 43 protrudes into the cavity 3 and pushes forward the receding plate 8 of the main mold 5 installed in the cavity 3. put out. When the plate 8 of the main mold 5 is pushed forward by the extrusion pin 43 of the base mold (■), the ejection pin 83 provided on the plate 8
protrudes into the cavity 15, and injects the product P attached to the cavity 15 to the outside of the mold.

After the product P is injected, if the mold is clamped again, the base return pin 42 of the base mold ■ will protrude forward from the movable base mold 2 due to the base plate 4 pushed forward, and the return pin of the main mold 5 will be Since the pin 82 also protrudes forward from the movable mold 7 due to the advanced plate 8, both return pins 42,
82 comes into contact with the fixed base mold 1 and the fixed mold 6, and each pin 42.
The plates 4 and 8 to which 82 are attached are moved back, and the ejector pins 43 that were protruding into the empty chamber 3 are moved into the movable table mold 2 and the protrusions that were protruding into the cavity 15 are removed from the retracted plates 4 and 8. The pin 83tr is slid backward into the movable mold 7.

By repeating the above operations, the product P is continuously injection molded. If a failure occurs due to the mold during injection molding or the mold needs to be cleaned, leave the base mold I as it is and remove only the malfunctioning main mold 5 from the empty space 8 of the base mold I, or Remove only the main mold 5 that requires cleaning,
Instead, another main mold 5 is attached and molding is continued again, during which time the main mold 5 is repaired or cleaned.

The main mold 5 to be installed in the empty space 3 of the base mold I is the 1 of the base mold ■
Since it is small in size, about 1/3 to 1/6, it can be replaced simply by attaching and detaching the fixing plate 9 attached to the outer periphery of the main mold 5, that is, fixing the fixing plate 9 and attaching and detaching several bolts 35. obtain.

Incidentally, the injection mold according to the present invention is not limited to the above-mentioned embodiment, and for example, a concavo-convex portion for mold matching is provided at the separation line between the fixed mold 6 and the movable mold 7 that constitute the main mold 5. 6a, 7
a, or if the main mold 5 is provided with a support 80 corresponding to the support 40 of the base mold I and a pin in the grain corresponding to the guide pin 44, the accuracy of the product P can be further improved.
Concave and convex portions 9a and 9b that fit into each other are provided at the separation line between the front fixing plate 19 for attaching the fixed mold 6 to the fixed base mold 1 and the rear fixing plate 29 for attaching the movable mold 7 to the movable base mold 2. Ba,
The attachment of the fixing plate 19.29 becomes more stable. In addition, the fixed base mold 1 and the movable base mold 2 that constitute the base mold I, the empty space 3 provided in the base mold ■, the fixed mold 6 and the movable mold 7 of the main mold 5 installed in the empty space 3, and the main mold The shape and structure of the fixing plate 9 for fixing the mold 5 to the empty space 3 of the base mold I can be changed as appropriate as long as it does not go against the gist of the present invention." [Effects of the Invention] Therefore, in molding synthetic resin products. By using the injection mold according to the present invention, you only need to install the heavy base mold once on the molding machine, and from then on, you can use the light main mold with less than 1/3 of the base mold to produce the product. You can replace it accordingly, so 1
．． It is extremely easy to replace molds, and even if different products are molded using different molds, alloy molds can be used in common, so we only provide small and lightweight main molds that match the product. Bye. As a result, it becomes easier to manufacture molds,
It is also possible to provide molds at low cost. In addition, the main mold is inserted from the outer periphery into the empty space of the base mold so as to form a right angle to the mold clamping direction, and a fixing plate is bolted to the rear of the main mold.

Since the main mold is installed by holding the main mold in place, the means for attaching and removing the main mold is extremely simple and easy. Furthermore, multiple main molds are attached to a base mold, so even if one of them breaks down or becomes dirty, only that main mold can be replaced with another main mold and molding can continue. Since the main mold can be repaired and the dirty main mold can be cleaned, the downtime of the molding machine due to mold failure or cleaning can be significantly shortened, and the molding machine can be used more efficiently. The injection mold of the invention has the above-mentioned features of simplifying mold replacement and improving molding efficiency, and has a significant practical effect on improving the production of synthetic resin products.

[Brief explanation of the drawing]

Fig. 1 is a vertical cross-sectional view showing the main structure of an injection mold according to the present invention, Figs. 2 and 3 are longitudinal cross-sectional views showing an example of its use, and Fig. 4 is a vertical cross-sectional view showing an example of forming a cavity. Longitudinal cross-sectional view of the base mold, No. 5
The figure is a vertical cross-sectional view showing the main structure of the main mold, Figure 6 is a vertical cross-sectional view of the main mold in the open state, Figures 7 (a) and (b) are vertical cross-sectional views of similar main molds, FIG. 8 is a partially cutaway side view of the fixed plate, and FIGS. 9 and 10 are front views of a movable platform type showing an example of forming a vacant chamber. ■... Base mold, 1... Fixed base mold, 2... Movable base mold, 22... Mounting plate, 3... Vacant room, 5... Main mold,
6... Fixed platform type 7... Movable platform type, 15... Carriage tee, 20, 70... Plate loose fitting part, 21.71.
・・Hem part, 4, 8... Plate, 40° 80... Support, 41... Sprue lock pin, 42.82...
・Return pin, 43... Ejection pin, 83... Ejection pin, 44... Guide pin, 9, 19, 29... Fixed plate, 12... Guide pin, 10... Spring, B
...Fixed platen, C...Mold clamping ram, D...Movable platen, S
...Sprue, R...Runner, G...Gate-16
= ωto

Claims (1)

[Claims] 1) At least two or more chambers are provided at the separation line of the joint between the fixed base mold 1 having the sprue S and the movable base mold 2 having a base plate 4 at the rear that moves back and forth in the mold clamping direction. The empty chamber 3 is provided perpendicular to the mold clamping direction, and the table plate is provided with a table return pin 42 that penetrates at least the movable table mold and comes into contact with the fixed table mold, and an extrusion pin 43 that reaches the empty chamber. A base mold for injection molding, characterized in that a runner R is connected to the vacant space through a sprue of the base mold, and an ejector pin can be moved in and out of the cavity by a base plate that moves back and forth. 2) Fixed mold 6 attached to fixed base mold 1 having sprue S
The separation line of the joint of the movable mold 7 to be attached to the movable mold 2 having the base plate 4 that moves back and forth in the mold clamping direction is provided so as to coincide with the separation line of the base mold, and the separation line is A return pin 82 forming the cavity 15 and at the rear of the movable mold passes through at least the movable mold and abuts against the fixed mold.
A main mold for injection molding is characterized in that a plate 8 equipped with a protruding pin 83 that reaches the cavity is provided so as to be movable back and forth, and a runner R and a gate G are provided which communicate from the cavity to the sprue of the base mold.