JPS6316490Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to an improvement in a raw material mixing head used in reactive injection molding.

(Prior Art) Conventionally, as shown in FIG. 9, a mixing head for reaction injection molding is slidably inserted into a raw material mixing head block 1 and the raw material mixing head block 1.
Circulation grooves 2a and 2b that serve as flow paths during reactive raw material circulation
It consists of a piston rod 2 of a simple monolithic structure, having a In addition, 3 is an upper block, and 4 is a runner leading to the molding die.

When injection molding is not performed, as shown by the solid line arrows in FIG.
The raw material for reactive injection molding supplied through the piston rod 2 is circulated through circulation grooves 2a and 2b provided in the piston rod 2 to the inflow channels 5 and 6 at a portion not shown by the outlet channels 7 and 8. There is.

For example, if the raw materials for reactive injection molding are referred to as liquid A and liquid B, liquid A flows in from the inflow path 5,
It flows out from the outflow path 7 through the circulation groove 2a of the piston rod 2, and circulates to the inflow path 5 at a portion not shown.

On the other hand, liquid B flows in from the inflow path 6, passes through the circulation groove 2b of the piston rod 2, and flows out from the outflow path 8.
It circulates to the inflow path 6 at a portion not shown.

Also, during reaction injection molding, the piston rod 2
is pulled to the position indicated by the two-dot chain line, and as shown by the two-dot chain arrow, liquid A flows in from the inflow path 5 and liquid B flows in from the inflow path 6, and the space formed by the lowering of the piston rod 2. The mixture is mixed and reacted in a section 9, and is injected into a mold, not shown, via a runner 4 while being turned into a resin.

Such a conventional reactive injection molding raw material mixing head molds a single reactive injection molding raw material combination in one injection, and only molded products made from a single reactive injection molding raw material combination. The disadvantage is that it cannot be obtained.

In addition, the conventional reactive injection molding raw material mixing head is a single reactive injection molding raw material mixing head.
This method has disadvantages in that it is not possible to injection mold a plurality of raw material combinations for reactive injection molding in multiple batches, and that it is not possible to self-clean the inside of the raw material mixing head for reactive injection molding.

(Problems to be solved by the invention) This invention has been made in view of the above-mentioned circumstances, and the problems to be solved by the invention are as follows: For reactive injection molding, which allows multiple injection molding raw material combinations to be injection molded in multiple batches, and also allows for self-cleaning of the inside of the raw material mixing head for reactive injection molding. The aim is to provide a raw material mixing head.

(Means for Solving the Problems) In order to solve the above problems, the present invention includes a block having a plurality of sets of inflow passages and a plurality of sets of outflow passages through which raw materials for reaction injection molding pass; an outer piston that is slidably inserted into the outer piston, and an inner piston that is slidably inserted into the outer piston, and the outer piston and the inner piston are
By the relative lowering of each of the outer piston and the inner piston, one of the plurality of sets of inflow passages is connected to a runner in the injection mold, and the other set of inflow passages are connected to the respective inflow passages. It is characterized in that the means is provided with a circulation groove connected to the corresponding outflow passage.

(Function) In this means, when one combination of raw materials for reaction injection molding is injection molded, first, for example, the outer piston is lowered. Then, among the plurality of sets of inflow channels in the block, only the inflow channels leading to the raw materials for reaction injection molding to be combined are connected to the runner. Then, the raw materials for reaction injection molding to be combined mix and react with each other in the outer piston and the space created by the descent, and are supplied to the runner.

On the other hand, other raw materials for reaction injection molding flow from the respective inflow passages through the circulation grooves of the inner piston to the outflow passage, and are circulated back to the inflow passage. After injection molding using the first combination is completed, the outer piston rises to flush out the remaining mixed raw material into the space to perform self-cleaning.

Next, when another combination of raw materials for reaction injection molding is injection molded, the inner piston descends and performs the same action as described above.

(Example) An example of the present invention will be described based on FIGS. 1 to 8. In FIG. 1, a runner 12 is formed between a block 10 and an upper block 11, which is a passage for the mixed raw material into the mold. Inside the block 10, there are provided a plurality of sets of inflow passages and a plurality of sets of outflow passages, which are passages for raw materials for reaction injection molding, which will be described later. An outer piston 13 is inserted into the block 10 so as to be slidable inside the block 10, and an inner piston 14 is inserted into the outer piston 13 so as to be slidable inside the outer piston 13. ing.

The lower portion of the outer piston 13 is mounted within the outer piston block 15, and the bottom portion 13a of the outer piston block 13 can rise or fall within the chamber 15a of the outer piston block 15. Pipes 16 and 17 constituting a hydraulic circuit are connected to the chamber 15a, and when hydraulic pressure is applied to the pipe 16, the bottom part 13a lowers, and when hydraulic pressure is applied to the pipe 17, the bottom part 13a rises. There is. Similarly, the lower portion of the inner piston 14 is mounted within the inner piston block 18, and the bottom portion 14a is moved downward or upward within the chamber 18a by hydraulic pressure from the pipes 19 and 20.

Next, in this example, the raw materials for reaction injection molding are called liquid A, liquid B, liquid C, and liquid D, and the combinations to be mixed and reacted are the combination of liquid A and B, and liquid C and D. In combination with Although not shown in FIG. 1, the block 10 includes a set of inflow passages 21 and 22 and a set of outflow passages 2 for liquids A and B.
3 and 24 are provided in a direction perpendicular to the paper plane of FIG. 1 (see FIGS. 2 and 4). And liquid C,
As for liquid D, as shown in FIG.
8 is provided.

The outer piston 13 and the inner piston 14 have a plurality of inflow passages and outflow passages corresponding to the plurality of sets.
Circulation grooves as shown in FIGS. 2 to 4 are provided. Note that FIGS. 3 and 4 show the case where the raw material liquid is in a circulating state.

For example, the C liquid sent from the inflow path 25 is transferred to the circulation groove 2 provided in the outer piston 13.
9. It flows through the communication path 30 to the circulation groove 31 provided in the inner piston 14, and the outer piston 13
It reaches the outflow path 27 through a communication path 32 and a circulation groove 33 provided in the , and is further fed into the inflow path 25 again at a portion not shown and circulated there.

Similarly, the D liquid sent from the inflow path 26 reaches the outflow path 28 via the circulation groove 34, the communication path 35, the circulation groove 36, the communication path 37, and the circulation groove 38.

On the other hand, the A liquid sent from the inflow path 21 reaches the outflow path 23 via the circulation groove 39 provided in the outer piston 13, and the B liquid sent from the inflow path 21 similarly reaches the circulation groove 40. It has a structure that leads to the outflow path 24 via the.

The operation of the raw material mixing head for reaction injection molding constructed as above will now be described.

First, when mixing and reacting liquids A and B, oil pressure is applied to the piping 16 described above, and the outer piston 13
is lowered to the position shown in Figure 5. Then, liquid A and liquid B, which had been in a circulating state until then,
They mix and react in the space 41 created by the descent of the outer piston 13, and are supplied to the runner 12. At this time, liquid C and liquid D are in a circulating state as shown in FIG. 6 via the above-mentioned circulation groove and communication path. After the mixing and reaction of liquid A and liquid B is completed, hydraulic pressure is applied to the pipe 17 to raise the outer piston 13. Then, the mixed liquid of liquid A and liquid B remaining near the space 41 is transferred to the runner 1 by the outer piston 13.
2, and self-cleaning is performed.

Next, when mixing and reacting liquid C and liquid D,
Hydraulic pressure is applied to the pipe 19 to lower the inner piston 14 to the position shown in FIG. Then, liquid C and liquid D, which had been in a circulating state until then, mix and react in the space 42 created by the lowering of the inner piston 14, and are supplied to the runner 12. At this time, liquid A and liquid B are transferred to the circulation groove 3.
9 and 40, it is in a circulating state as shown in FIG. After the mixing reaction of liquid C and liquid D is completed, self-cleaning of the vicinity of the space 42 is performed by raising the inner piston 14.

With the above operations, the process of dividing liquids A and B and liquids C and D into two parts and injecting them from the same reactive injection molding raw material mixing head is completed, and when switching raw materials for reactive injection molding, the process is completed. This makes it possible to self-clean the raw material mixing head for reactive injection molding.

If you want to further increase the number of combinations of raw materials, you can do so by increasing the diameters of the outer piston and inner piston inserted into the block, and by inserting another piston into the inner piston. It is.

(Effects of the invention) The invention is constructed as described above,
According to the present invention, in a single raw material mixing head for reactive injection molding, it is possible to perform multi-stage injection molding in which multiple combinations of raw materials are injection molded in multiple steps, and self-cleaning within the mixing head is possible. becomes.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing a raw material mixing head for reactive injection molding capable of multi-stage injection according to an embodiment of the present invention, FIG. 2 is a partial plan view of FIG. 1 viewed from the negative direction, and FIG. Figure 2 is a partial sectional view of Figure 2 viewed from the - direction, Figure 4 is a partial sectional view of Figure 2 viewed from the - direction, Figures 5 and 6 are Figures 3 and 4 viewed from the - direction. , Figures 7 and 8 are views showing the state in which the outer piston is lowered as seen from the - direction, Figures 7 and 8 are diagrams in which the inner piston is lowered in Figures 6 and 5, respectively. 1 is a sectional view showing the main parts of a conventional raw material mixing head for reactive injection molding. A, B, C, D...Raw materials for reaction injection molding, 10
...Block, 12...Runner, 13...Outer piston, 14...Inner piston, 21,2
2, 25, 26...Inflow path, 23, 24, 27,
28...Outflow path, 29, 31, 33, 34, 3
6, 38, 39, 40... Circulation groove.

Claims (1)

[Scope of utility model registration request] a block having a plurality of sets of inflow passages and a plurality of sets of outflow passages through which raw materials for reaction injection molding pass; an outer piston that is slidably inserted into the block; and an inner piston that is slidably inserted therethrough, and the outer piston and the inner piston form one set of the inflow passages among the plurality of sets of inflow passages by injection molding by the relative lowering of the outer piston and the inner piston, respectively. A raw material mixture for reactive injection molding capable of multi-stage injection, characterized by comprising a circulation groove connected to a runner in a mold and connecting another set of inflow paths to the outflow path corresponding to each inflow path. Head.