JPS5856338B2 - reaction injection molding equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a reaction injection molding apparatus for foam molding a foamable synthetic resin.

Conventionally, in this type of reaction injection molding equipment, a foamable synthetic resin is injected into the mold, but since the viscosity of this foamable synthetic resin is generally about 1000 to 2000 CP, it takes a lot of effort when injecting it into the mold. It is often injected with air entrained in it.

When molded in such a case, the air causes bubbles to be formed on the surface of the molded product, resulting in a problem that a defective product may be molded.

The present invention was made in view of the above points, and involves applying vibration to the mold when injecting the foamable synthetic resin into the mold, and injecting the foamable synthetic resin while vibrating the mold. This provides a reaction injection molding apparatus that can prevent the entrainment of air and prevent molding of defective products caused by air.

Next, one embodiment of the present invention will be described with reference to the accompanying drawings.

1 is a base body, a support 2 is fixed to the upper part of this base body 1, a shaft 3 is fixed between the upper end of one side of this support 2,
One side of a horizontal portion 4a of a machine frame 4 formed in a substantially U-shape is rotatably mounted on this shaft body 3.

Further, a cylinder 5 is fixed to one end of the base body 1, a horizontal shaft 7 is rotatably connected to the tip of a piston rod 6 of the cylinder 5, and both ends of the horizontal shaft 7 are connected to the machine frame 4. A joint 8 fixed in the middle of the horizontal part 4a of
It is attached to the shaft.

The machine frame 4 is normally held by the shaft body 3 and the piston rod 6 of the cylinder 5, and the piston rod 6 is expanded and contracted by the movement of the cylinder 5, so that the machine frame 4 can be rotated around the shaft body 3. It has become.

Next, a drive shaft 9 and a rotation shaft 10 are attached to a bearing body 1 at the upper end of a vertical portion 4b protruding from both sides of the machine frame 4.
1, and support frames 12 in the form of horizontally long rectangular plates are fixed to the inner ends of the drive shaft 9 and rotation shaft 10, respectively.

Further, guide shafts 13 are fixed to each of the four corners between the opposing support frames 12, and a plate-shaped balance weight 14 is attached to one end of each guide shaft 13 by inserting its four corners so that it can move forward and backward. A pair of mold supporting die plates 16 and 1 support the mold 15 from both sides on each guide shaft 13 at a predetermined position inside the balance weight 14.
7 are inserted through its four corners and are attached to each other so that they can move forward and backward.

Therefore, the weight of the balance weight 14 and the mold 15
and the weight ratio of the pair of die plates 16 and 17 and the holding mechanism that holds them are approximately the same.

Further, mounting recesses 18 and 19 are formed at both ends of the balance weight 14 in the width direction and at both ends of the one die plate 16 in the width direction.
8. A cylinder 20 is provided in the 19, and the cylinder 20 is installed and fixed in one of the mounting recesses 19, and the tip of the piston rod 21 of this cylinder 20 is attached to both ends of the other die plate 17 in the width direction. It is fixed.

The movement of the cylinders 20 on both sides causes the other die plate 17 to move forward and backward relative to the fixed die plate 16 via the piston rod 21, thereby loading and unloading the mold 15 and clamping the mold. ing.

Further, a servo actuator 22 as a vibration generator is fixed to approximately the center of the balance weight 14,
A vibration receiving plate 24 is fixed to the tip of the drive shaft 23 of the servo actuator 22, and one end of a vibration receiving rod 25 is fixed to both ends of the vibration receiving plate 24. It is fixed to one of the die plates 16.

Further, guide holes 26 are provided at both ends of the balance weight 14.
are formed, and cylinders 27 are formed in the guide holes 26 on both sides.
is mounted, and one end of this cylinder 27 is attached to the vibration receiving plate 24.

Also, the piston rod 2 at the other end of this cylinder 27
An extrusion plate 30 slidably attached to the vibration receiving rod 25 is fixed to the tip of the extrusion plate 9, and one end of an extrusion pin 31 for extruding the molded product is fixed to the center of the extrusion plate 30. The other end of this extrusion pin 31 is slidably inserted into a sliding hole 32 bored in one of the die plates 16.

Further, a locking body 33 is fixed to each of the guide shafts 13 on both sides between the balance weight 14 and one tie plate 16, and the center of the first link plate 34 is attached to the locking body 33 as a rotation fulcrum. It is rotatably mounted on a support shaft 35.

Also, one end of the second and third link plates 36 and 37 are attached to the shaft 38 at both ends of the first link plate 34.
．． The other end of the second link plate 36 is rotatably connected to the balance weight 14 at a shaft 40, and the other end of the third link plate 37 is rotatably supported at a shaft 40. The shaft 4 is attached to one die plate 16.
They are rotatably connected at 1.

Further, a rack (not shown) is formed at the outer end of the drive shaft 9, and a pinion attached to the piston rod of the cylinder 42 is engaged with this rack. The drive shaft 9 is driven through the mold 15 at an angle of approximately 45 degrees.
can be rotated.

Next, the operation of the above configuration will be explained.

The mold 15 is installed between a pair of die plates N6.17, the cylinders 20 on both sides are operated, and the piston rod 21
is expanded and contracted to move the other die plate 17 to the one die plate 16 side, and the mold 15 is held between this pair of die plates N6.17.

Next, a foamable synthetic resin of a predetermined viscosity is injected into the mold 15. In this case, when the servo actuator 22 is driven, it is poured into one of the die plates 16 via the drive shaft 23, the vibration receiving plate 24, and the vibration receiving rod 25. The vibrations are applied, and the molds 15 held therebetween are also subjected to vibrations.

Therefore, when injecting the foamable synthetic resin into the mold 15, the foamable synthetic resin is injected into the mold 15 under conditions suitable for moldability without entraining air, and air bubbles appear on the surface of the molded product. This will prevent this from occurring.

In addition, in the above case, the reaction force from the mold 15 of the servo actuator 22 which imparts vibration to the mold 15 will have a large effect on the aircraft body, floor surface, etc. 22 is the balance weight 14 and the mold 1
5, and is structured so that the weight ratio of the balance weight 14 and the mold 15 and the holding mechanism that holds it is balanced, so that the reaction force of the vibration against the mold 15 caused by the servo actuator 22 is The balance weights 14 cancel each other out and balance each other, so that the reaction force from the mold 15 is reliably prevented from being transmitted as vibrations to the aircraft body, floor surface, etc.

When injecting foamable synthetic resin into the mold 15, the cylinder 5 is operated in advance, its piston rod 6 is extended, and the machine frame 4 is rotated about the shaft body 3 as shown, for example, by the chain line in FIG. In some cases, the mold 15 held by the first link plate 3 is tilted at a predetermined angle or placed in various positions.
Reference numeral 4 denotes second and third link plates (36) that rotate around the support shaft 35 of the locking body 33 in the direction of rotation of the machine frame 4, and are pivotally supported at both ends of the first link plate 34. ．．
37 are simultaneously rotated in conjunction with each other, and as the second and third link plates 36 and 37 rotate, the balance weight 14 and the mold 15, which are pivotally attached to the second and third link plates 36 and 37, are supported. Since it is rotated, the balance weight 14, the mold 15, and its holding mechanism are always balanced by the link mechanism, so that the mold 15 and balance weight 14 are always located at symmetrical positions with the servo actuator 22 at the center. Therefore, the reaction force from the mold 15 caused by the servo actuator 23 is
No vibration is transmitted to the aircraft body, floor, etc. without being affected by the position of 5.

To further explain the above relationship with reference to FIGS. 4 and 5, the weight of the balance weight 14 and the mold 1
5 and the first to third link plates 34, 36.
The relationship with the length of 37 is the following % formula %: S (S, +82): Total stroke of servo actuator S,: Stroke of mold weight S2: Stroke of balance weight m1: Mold weight m2: Balance weight weight 11 : Length of the link on the m1 side 12 : Length of the link on the m2 side Therefore, when the above relationship is satisfied, the balance weight 14, the mold 15, and the link mechanism are always balanced.

In the above embodiments, the balance weight may be a mold for producing the same molded product, or may be another mold or other heavy object as long as it has the same weight.

According to the present invention, vibration is imparted to the mold supported by the die plate by a vibration generator, and foamable synthetic resin is injected into the mold while vibrating the mold, without entraining air. The foamable synthetic resin can be foam-molded, so there is no fear that air bubbles will be formed on the surface of the molded product, and it is possible to prevent defective products from being molded due to the inclusion of air.

In addition, a balance weight composed of a weight that balances the weight of the mold and a pair of Goui plates that supported it is provided at a position symmetrical to the mold, and this balance weight and one Goui plate are rotated in the middle. Since they are connected by a link mechanism with a dynamic fulcrum, when vibration is applied to the mold by the vibration generator, the reaction force generated by the vibration is reliably canceled and balanced by the balance weight, and the It is possible to reliably prevent vibrations from being directly transmitted as vibrations to the aircraft body or the like.

[Brief explanation of drawings]

The figures show one embodiment of the present invention, in which Fig. 1 is a front view of a reaction injection molding apparatus, Fig. 2 is a partially cutaway plan view of the same, Fig. 3 is a side view of the same, and Fig. 4 is a side view of the same. and FIG. 5 is an explanatory diagram of the same link mechanism. 4... Machine frame, 13... Guide shaft, 16.
17...Pair of die plates, 14...
・Balance weight, 15...Mold, 22...
... Servo actuator as a vibration generator,
34, 36. 37... link mechanism, 35...
...Rotation fulcrum.

Claims (1)

[Claims] 1 A pair of die plates supported on a machine frame via a plurality of guide shafts, a mold supported between the pair of die plates for molding a foamable synthetic resin, and at least one die that supported this mold. a vibration generator connected to the plate and imparting vibration to the mold when foaming synthetic resin is injected into the mold; A balance weight composed of a weight that balances the weight of the die plate, and a link mechanism that connects the balance weight and one of the die plates and has a rotation fulcrum in the middle thereof. Reaction injection molding equipment.