JP4033751B2 - Molding method and mold for resin molded products - Google Patents

Description

[0001]
[Technical field to which the invention belongs]
The present invention relates to a method for molding a resin molded product in which an insert part made of a metal or other material is set in a mold and molded, and a mold used in the method.
[0002]
[Prior art]
One of the resin molded products is an electric fusion joint used to connect resin pipes or a resin pipe and a metal pipe. In this joint, a heating wire is embedded in a coil shape in an insertion port into which the end portion of the resin tube is inserted, and the heating wire is heated by energizing the heating wire to melt the resin around it. As a forming method, a sleeve made of a thermoplastic resin or metal in which a heating die is wound in a coil shape using a fixed die and a movable die that can be opened and closed. There is known a method in which injection molding is performed after the movable mold is closed after the mold is set in the cavity of the fixed mold or the movable mold.
[0003]
For joints that connect metal pipes and resin pipes, and for joints that are inserted with metal connection fittings that connect metal pipes, molding is also possible after setting the connection fittings in the cavity of a fixed mold or movable mold. This is done by closing the mold and injection molding.
[0004]
Setting of such sleeves and connection fittings (hereinafter referred to simply as “insert parts”) such as sleeves, connection fittings and other parts to be inserted into the mold, and taking out the joints that are molded products from the molded molds after molding Is often done automatically by robots, but may also be done manually.
[0005]
[Problems to be solved by the invention]
Taking the above-mentioned joint as an example, the insertion of the insert part into the mold and the removal of the joint from the molded mold are performed after the movable mold is opened. While the robot's movement is limited due to the narrow area, when working manually, the work area is also small, the mold is heated and the working environment near the mold is hot, and the open movable mold There are tie bars, guide bars, etc. between the mold and the fixed mold, the foot is bad and it becomes an obstacle when going back and forth between both molds, so workability is bad and production stability is lacking There was also a problem with safety.
[0006]
Such a problem occurs not only in the above-described joint, but also in the case where the insert part is set in a mold even in a general insert molded product, or the work of taking out the molded product from the mold after molding is performed manually.
The present invention provides a method for molding a resin molded product capable of solving the above-described problems that occur when an insert part is set in a mold or an operation of taking out a molded product from a mold after molding is performed manually, It aims at providing the metal mold | die used by a method.
[0007]
[Means for solving problems]
The mold according to the present invention is a mold for a resin molded product composed of a fixed mold and a movable mold that can be opened and closed, and is detachable from the cavity block, and supports an insert part and a molded article incorporating the insert part. a forming position for forming the support bracket, the work space is slid or pivoted to the retracted position taken sufficiently configured to be switched, and extruding the extrusion means from the mold the support fitting, extruded from the die Supporting means for supporting the supporting metal fitting and guiding it to the retracted position is provided, and the supporting metal fitting is supported on the supporting means and pushed out from the mold together with the supporting means by the pushing means.
[0008]
Here, the extrusion means is not particularly limited as long as it has a function of extruding the support fitting, and examples thereof include a hydraulic cylinder and a pneumatic cylinder.
[0009]
Examples of the support means include a rail, a table, a cradle, and the like. When the support fitting is moved along the moving means, for example, a hydraulic cylinder, a pneumatic cylinder, a rack provided on the support fitting, and the rack A pinion rack mechanism composed of a pinion that is rotationally driven by a motor, an endless chain having both ends connected to a support bracket, and a sprocket that meshes with the chain and is rotationally driven by a motor, and connected to a support bracket. A power device such as a winding device that pulls the support fitting by winding a wire or rope can be used, or it can be pushed and moved manually. When pushing and moving manually, it is desirable to attach a roller or a wheel to the support fitting so that the support means can be moved by rolling so that the movement can be performed smoothly.
[0010]
According to the present invention, among the molds after opening the movable mold, in a state in which either switched to slide or pivot to the retracted position of the support bracket in one or die counterpart, the front support bracket In addition, the workability is improved because there is enough work space and it is less susceptible to the thermal effects of the mold, and if the retreat position is set to a place where there are no obstacles, the workability is further improved and the size and weight are improved. Large insert parts and molded products can be easily attached to and removed from the mold cavity and support metal fittings, improving safety. In addition, when automation is considered, the work area of the robot and the like is widened, and the operation and workability are improved.
[0011]
The insert part used in the present invention may be used by being integrated into a molded product, or after molding, for example, a metal sleeve fitting around a heating wire in a joint, You may take out from a molded article.
[0012]
In the preferred invention, since only the support fitting is switched between the molding position and the retracted position, the power or labor required for switching can be minimized.
The molding method of the present invention is to mold a resin molded product using the above-described mold.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an elbow joint mold according to an embodiment of the present invention will be described.
As shown in FIG. 1, the mold comprises a fixed mold 1 and a movable mold 2 that can be opened and closed. The mold is closed during injection molding and can be opened as shown before and after molding. .
[0014]
The fixed mold 1 is fitted with a mounting plate 3 fixed on a base (not shown), a cavity plate 4 fixed to the mounting plate 3, and flush with the cavity plate 4 in a recess of the cavity plate 4. The cavity block 5 has a trapezoidal shape when viewed from the front (left side in FIG. 1), and a base and a side of a cradle, which will be described later, are detachably fitted under the cavity block 5. A concave groove 6 is formed.
[0015]
The movable mold 2 is movably supported on the base (not shown). Then, it is guided by a tie bar (not shown) connected to the fixed mold 1 so as to advance and retreat toward and from the fixed mold 1 by a hydraulic cylinder. A cavity plate 9 fixed to the mounting plate 8 and a cavity block 10 attached to the cavity plate 9 are provided, and an ejector plate 11 and an extrusion plate 12 are further arranged on the left side of the cavity plate 9 shown in FIG. Has been.
[0016]
These will be described in detail below.
The cavity plate 9 has a pair of insertion holes 15 into which the guide bars 14 projecting in pairs above and below the cavity plate 4 on the fixed side are respectively inserted in the front and rear of FIG. 1 (left and right in FIG. 2). 1 (only the lower side is shown in FIG. 1), and is guided by the guide bar 14 inserted into each insertion insertion hole 15 so as to move forward and backward toward the cavity plate 4 on the fixed side. As shown in FIG. 2, a slide core 16 and a device 17 composed of a hydraulic cylinder that moves the slide core 16 forward and backward in the direction of the arrow are arranged symmetrically on the front, and the left and right slide cores 16 are controlled by a control device (not shown). By controlling the device 17, it advances and retreats synchronously.
[0017]
The cavity plate 9 also has a guide bar 19 that protrudes toward the cavity plate 4 and is inserted into the insertion hole 7 formed in the cavity plate 4, and an extrusion unit that pushes out the cavity block 10. As shown in FIGS. 1 and 2, the extrusion means includes a pair of hydraulic cylinders 20 attached to both sides of the cavity block 10, an extrusion plate 12 connected to the piston rod 21 of both hydraulic cylinders 20, and The pusher plate 21 includes pusher bars 21 projecting laterally on both sides of the lower side of the pusher plate 12. The function of the pusher bar 21 will be described later.
[0018]
Similarly to the cavity block 5, the cavity block 10 is also fixed in the recess of the cavity plate 9 so as to be flush with the cavity plate 9, and a trapezoidal frame-shaped support fitting 23 is fitted around the cavity block 10 although not shown in the figure. A concave portion having a trapezoidal frame shape is formed, and a concave groove 22 facing the concave groove 6 is formed under the cavity block 10 so as to communicate with the concave portion.
[0019]
The support bracket 23 is fixed on the base 24, the base 24 is placed on the receiving base 25 of the support means, and a protrusion 27 protruding from the base 24 is fitted into a rail groove formed in the longitudinal direction of the receiving base 25. As a result, the base 24 can move together with the support fitting 23 only in the longitudinal direction of the cradle 25, and the cradle 25 is further passed through the guide bar 19, and advances and retreats along the guide bar 19. 24 and the support metal fitting 23 together with the recess around the guide block 10 and the groove 22 are detachably mounted. The protruding portion on the right side is fixed when the movable mold 2 is closed and combined with the fixed mold 1. It is fitted and mounted in the concave groove 6 on the mold side.
[0020]
In this way, the support metal fitting 23 is fitted together with the base 24 and the cradle 25 into the recesses and the concave grooves 22 around the cavity block 10, and the above-mentioned push rod 21 hits the base 24 from the side surface and protrudes the base 24 as shown in FIG. 1 is guided by the guide bar 19 and pushed out, and the pushing plate 12 is moved to the left in FIG. 1 by the hydraulic cylinder 20, and the pushing bar 21 is moved back to the left. When the guide bars 14 and 19 are inserted into the fitting insertion holes 7 and 15 and are combined with the fixed mold 1, the base 24 and the right side of the receiving base 25 are first fixed molds. The support metal 23, the base 24, and the right side of the cradle 25 are fitted into the recesses and the recesses 22 around the cavity block 10 on the movable mold side. Yes.
[0021]
The support fitting 23 is formed with a semicircular concave portion 29 into which a metal sleeve 28 is fitted, which is an insert part, on the left and right inclined portions, and a circumferential groove in which the flange 30 of the sleeve 28 is fitted on the peripheral surface of the concave portion 29. 31 (see FIG. 3) is formed, and the sleeve 28 is detachably attached and held. In the figure, reference numeral 33 denotes a support portion that supports the sleeve 28 fitted into the recess 29.
[0022]
Although the ejector plate 11 shown in FIG. 1 is not shown, it has an extruding rod, like the extruding plate 12, and is advanced and retracted by a hydraulic cylinder to slightly extrude the sleeve 28 with the extruding rod, and the sleeve 28 and the joint 32 of the molded product. Is lifted from the recess 29 of the support metal 23 so that it can be easily taken out.
[0023]
Next, a method for forming an elbow joint using the mold will be described.
As shown in FIG. 1, the movable die 2 is opened, the extrusion rod 21 is protruded by the hydraulic cylinder 20, and the support fitting 23 is extruded from the movable die 2 together with the base 24 and the cradle 25. Is pushed in the longitudinal direction of the cradle 25 and pulled away from the movable mold 2 and retracted to the retracted position indicated by the one-dot chain line in FIG.
[0024]
In the retracted position, a pair of sleeves 28 in which heating wires are wound in a coil shape are fitted into the recesses 29 of the support fitting 23 by fitting the flanges 30 to the circumferential grooves 31 respectively, and then the original molding indicated by the solid line in FIG. Push back to position. In the state shown in FIG. 1, the push rod 21 is retracted to the position indicated by the one-dot chain line in FIG. 1 by the operation of the hydraulic cylinder 20, and then the movable die 2 is closed and combined with the fixed die 1 (FIG. 4). In this state, the support metal fitting 23 is fitted into the recess around the cavity block 10 on the movable mold side, and the base 24 and the receiving base 25 are fitted into the recessed grooves 6 and 22 of the fixed mold 1 and the movable mold 2. To do. The sleeve 28 and the support portion 33 are fitted into a recess (not shown) formed in the cavity block 5 on the fixed mold side.
[0025]
Next, the left and right slide cores 16 are projected through the sleeves 28 by means of a device 17 comprising a hydraulic cylinder shown in FIG. Thus, a cavity 34 is formed around the sleeve 28 and the slide core 16 as shown in FIG. In this state, injection molding is performed. After molding, the movable mold 2 is retracted and opened, and the sleeve 28 is slightly pushed out by the ejector rod of the ejector plate 11 so that the joint 32 of the molded product has some play in the support bracket 23. Let it be supported. Next, the extrusion plate 12 and the extrusion rod 21 are moved to the solid line position in FIG. 1 to extrude the support bracket 23 together with the base 24 and the cradle 25. Thereafter, the support fitting 23 is pushed and moved together with the base 24 to the retreat position indicated by the one-dot chain line in FIG. Then, the joint 32 is taken out from the support fitting 23 together with the sleeve 28. FIG. 3 shows a state where the joint 32 is taken out. After taking out the joint 32, a new sleeve 28 around which a heating wire is wound is attached to the support fitting 23, and the above operation is repeated. The sleeve 28 incorporated in the joint 32 is extracted from the joint 32 after the joint is cooled.
[0026]
According to this method, the attachment of the sleeve and the removal of the joint after molding are performed by retracting the support fitting 23 to the retracted position. The retracted position is separated from the fixed mold 1 and the movable mold 2 and the two molds 1 and 2 is less affected by heat, and there are no tie bars, guide bars 14, 19 etc. at the foot as between the molds 1, 2, and a sufficient working space can be secured on the front surface of the support bracket 23. And safety are improved, thereby improving production stability. Moreover, since it is only necessary to push and move the support bracket 23, the labor load can be reduced.
[0027]
The above describes the method of forming an elbow joint using a metal sleeve. However, even when using a resin sleeve, other joints such as socket joints, cheese joints, saddle joints, and other joints are also used. A molded product incorporating another insert part can be molded by the same method, and the same effect can be obtained.
[0028]
【The invention's effect】
According to the first aspect of the present invention, the retracted position can be set at a position where there is no obstacle at the foot and sufficient work space for inserting and removing the insert part and the molded product can be taken, and at least the retracted position. Then, since there is no mold from the molding position, the work space can be afforded, and when automation by a robot or the like is considered, the work area of the robot or the like becomes wider, and the operation workability improves. In addition, even when the work is performed manually, the mold is hardly affected by heat, so that workability and safety are improved, and production stability is also improved. In addition, since the support fitting is pushed out together with the support means, the support fitting can be easily moved in only one direction when the support fitting is switched between the molding position and the retracted position.
[0029]
According to the second aspect of the present invention, since the pushing means pushes out only the support fitting, the power required for pushing can be minimized.
[Brief description of the drawings]
FIG. 1 is a partial cross-sectional side view of a mold showing a state in which a movable mold is opened.
FIG. 2 is a front view of a movable mold to which a support fitting is attached.
FIG. 3 is a front view of a main part of a movable mold that can be switched between a molding position and a retracted position.
FIG. 4 is a view showing a mode when a movable mold is united with a fixed mold.
[Explanation of symbols]
1 .. Fixed mold 2.. Movable mold 3, 8... Mounting plate 4, 9. · Extrusion plates 14 and 19 · · Guide bar 16 · · Slide core 17 · · Hydraulic cylinder device 20 · · Hydraulic cylinder 21 · · Extrusion bar 23 · · Support bracket 24 · · Base 25 · · Base 7 · · Ridge 28, sleeve 29, recess 30, flange 31, circumferential groove 32, joint 34, cavity

Claims (3)

In molds for consisting stationary mold openable and closable movable mold resin molded product, a detachable cavity block, forming position for forming the support bracket for supporting the insert part and or shaped article incorporating the insert part If, configured to be switched by sliding or pivoting in the retracted position work space taken sufficiently retracted the support brackets and extruding the extrusion means from the mold, and support the support bracket extruded from the die A mold for a resin molded product, characterized in that a support means for guiding to a position is provided, and the support fitting is supported on the support means and pushed out from the mold together with the support means by the extrusion means. Extrusion means pushes on the support means the support bracket from the mold according to claim 1 a mold for resin molded article according.   A method for molding a resin molded product using the mold according to claim 1.

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