JPH0318166Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The invention involves colliding and mixing multiple liquid plastic raw materials (hereinafter referred to as stock solutions) at high pressure, feeding them into a mold, and creating plastic products through a chemical reaction. This invention relates to a measuring attachment for a reaction injection molding machine for molding.

[Conventional technology]

Conventionally, in reaction injection molding machines, before starting the molding operation, it is necessary to measure the amount of each stock solution discharged from the mixing head in order to set the amount of supply of multiple stock solutions to the mixing head used for molding in advance. . As a means for measuring these stock solutions, a technique is known in which a metering valve is provided in the middle of a pipe that supplies the stock solution from a stock solution tank to a mixing head, and the stock solution is measured by this metering valve.

However, since this type of metering technology requires expensive equipment, a metering nozzle 2 is installed on the spool 5 of the mixing head 1, as shown in FIGS. 5 to 7.
0 is detachably attached, and a plurality of stock solutions discharged from the mixing head 1 when the spool 5 is operated are individually sent to a measuring container through the measuring nozzle 20 and measured.

As shown in FIGS. 5 to 7, the metering nozzle 20 includes a nozzle body 23 and a nozzle body 23.
It consists of tube bodies 22a, 22b attached to the nozzle body 23, and a valve stem 25 provided inside the nozzle body 23.
The nozzle body 23 is formed to have approximately the same diameter as the spool 5 of the mixing head 1, and has a valve rod 25 inserted therein to define flow paths 26a and 26b to separate and separate each stock solution. The nozzle body 23 is attached to the spool 5 by the male screw 25a and the nut 29, and each flow path 26 defined in the nozzle body 23 is attached to one end side of the nozzle body 23.
Communication holes 27a and 27b are formed which communicate with the jet nozzles 6a and 26b and which face the injection nozzles 6a and 6b of the mixing head 1 when the spool 5 is retracted. Each of the tubes 22a, 22b is attached to the other end of the nozzle body 23 as shown in FIG. 8, each base end communicates with each of the channels 26a, 26b, and each tip is provided with a metering point for each stock solution. A metering device (not shown) is connected.

In order to measure the stock solution with this metering nozzle 20, a hydraulic cylinder (not shown) is actuated from the state shown in FIG. Move the spool 5 to the position indicated by the two-dot chain line in Figure 5.
(Measuring nozzle 20) is moved back, and each stock solution is sprayed through the injection nozzles 6a, 6b → communication holes 27a, 27b → flow path 2.
6a, 26b → sent to the measuring device via tube bodies 22a, 22b. In this case, each stock solution is not mixed due to the presence of the valve stem 25 and is supplied separately to the metering device.

[Problem that the invention attempts to solve]

However, in the structure in which the metering nozzle 20 is attached to the spool 5 of the mixing head 1 as described above, a large inertial force due to the total weight of the metering nozzle 20 is exerted on the valve stem 25 when the spool 5 starts and stops operating. Male thread 25a and female thread 5a of spool 5
There is a problem that it acts on the threaded part of the

That is, when the diameter of the spool 5 is large, the diameter of the male screw 25a can also be made large, and the mounting rigidity of the metering nozzle 20 can be increased, so that it is possible to withstand the above-mentioned inertial force. It is. However, even if the diameter of the spool 5 becomes small to some extent (for example, less than 14 mm in diameter), it is not possible to reduce the weight and size of the metering nozzle 20 in proportion to this, so the mounting rigidity of the metering nozzle 20 with respect to the spool 5 increases. As a result, the installation of the metering nozzle 20 could not withstand the above-mentioned inertial force and was damaged, resulting in a problem in that it was virtually unusable.

Furthermore, even if the thickness t of the valve stem 25 is reduced to make the metering nozzle 20 lighter and smaller, the filler-containing stock solution is injected into the channels 26a and 26 through the injection nozzles 6a and 6b.
There is also the problem that when injecting toward the direction b, the injected parts Y1 and Y2 of the valve rod 25 that the undiluted solution collides with are worn out and damaged early.

Even if the spool has a small diameter, the mounting rigidity of the part that guides the stock solution to the metering device is high, it can withstand inertia, and it prevents damage to each part, making it highly durable. The purpose is to provide a metering attachment for molding machines.

[Means for solving problems]

The metering attachment of this invention includes an attachment body that is detachably attached to the tip of the mixing head body in the injection direction, and a spool sliding hole in the mixing head body when the attachment body is attached to the mixing head body. A guide hole is formed in the attachment body so as to communicate on substantially the same central axis, and a guide hole is fitted into the guide hole so as to be slidable in the axial direction, and a plurality of flow paths are defined within the guide hole. and a valve body that is detachably attached to the spool, and a plurality of flow paths that are communicated with the plurality of flow paths defined in the guide hole by the valve body and that supply the liquid plastic raw material to the metering device. It is composed of a supply hole.

[Effect]

When measuring the stock solution, the attachment body of the metering attachment is attached to the mixing head body, the valve body is attached to the spool of the mixing head, and the mixing head is operated. When the valve body is moving forward together with the spool of the mixing head, the injection nozzle of the mixing head is blocked by the spool and each stock solution is not supplied to the metering attachment side, but the mixing head is activated and the valve body is moved together with the spool. When the spool is retracted, a circuit is formed for the undiluted liquid from the injection nozzle to the flow path in the guide hole defined by the valve body to the supply hole in the attachment body to the metering device. By measuring the supplied amount, it is possible to know the injection amount of each stock solution during molding. When the measurement of the stock solution is completed, the measuring attachment is removed from the head body, and the process moves on to the molding process in which the stock solution is mixed and injected into a mold.

〔Example〕

1 to 3 show one embodiment of the metering attachment of this invention attached to a mixing head 1 of a reaction injection molding machine. First, the mixing head 1 will be explained.

The mixing head 1 has a main body 1a formed with a sliding hole 2 whose tip end serves as a mixing chamber 2a. This sliding hole 2 has a spool 5 integrally provided at the tip (the left side in the illustrated example; the same applies hereinafter) of the rod 4 of a hydraulic cylinder (not shown).
is fitted in a liquid-tight manner and slidable in the axial direction. A female thread 5a is formed at the tip of the spool 5 for attaching a valve stem 41 of a metering attachment 40 as described later. Further, the head body 1a is provided with injection nozzles 6a and 6b for the stock solution through fixed throttles 6a ₁ and 6b ₁ , respectively, with their tips facing the mixing chamber 2a, and bypass passages 7a and 7b are provided in the head body 1a. One end is connected to the injection nozzles 6a, 6b, and the other end is formed so as to be exposed to the circulation grooves 4a, 4b of the rod 4 when the stock solution is not being injected. Also, this head body 1
In a, the above-mentioned circulation grooves 4a and 4b are provided when the stock solution is not injected.
Return holes 10a and 10b are formed that communicate with the.

That is, as shown in FIG. 1, when the stock solution is not injected, the mixing chamber 2a is closed by the spool 5, and each stock solution tank (not shown)→injection nozzles 6a, 6b→bypass paths 7a, 7b→ Circulation groove 4
A, 4b→return holes 10a, 10b and a circulation path returning to each stock solution tank is formed. Further, when injecting the stock solutions, as shown in FIG. 2, the spool 5 is moved back, and the stock solutions collide and mix in the mixing chamber 2a, and are injected into the mold.

Next, the metering attachment 40 attached to the mixing head 1 will be explained below.

At the tip of the head body 1a of the mixing head 1 on the side in the injection direction of the stock solution, a measuring attachment 40 is installed.
Recess 4 on the rear end side of the attachment body 40a
A convex portion 1 formed at the tip of the head body 1a at 0b.
At the same time, a bolt (not shown) is inserted through the mounting hole 40c formed in the metering attachment 40, and is screwed into a screw hole (not shown) in the head body 1a to be detachably attached. There is.

This attachment body 40a has a valve stem 41.
a guide hole 42 that guides the slider and has approximately the same diameter as the sliding hole 2, and a supply hole 44 that communicates with the guide hole 42.
a and 44b are formed. The attachment body 40a is the attachment body 4.
0a attached to the head body 1,
The head main body 1a is arranged such that the guide hole 42 communicates with the sliding hole 2 and their central axes are substantially coincident with each other.
is attached to. The above supply holes 44a, 44
b is formed in the same vertical direction as each injection nozzle 6a, 6b, and this supply hole 44a, 44b
At the outlet, there is a pipe 5 for supplying the stock solution to the metering device.
0a and 50b are arranged in series.

The valve stem 41 is composed of a plate-shaped partition portion 41a and closing portions 41b ₁ and 41b ₂ having circular cross sections at both ends, and both portions are liquid-tight to the inner wall of the guide hole 42 and close to the guide hole. 42 so as to be slidable in the axial direction. Between the partition portion 41a and the guide hole 42 or the inner wall of the sliding hole 2, flow paths 48a and 48b for the stock solution are formed. The length of these channels 48a, 48b is
The distance is set approximately equal to the distance between the injection nozzles 6a, 6b and the supply holes 44a, 44b. Also,
The closed portion 41b ₁ at the rear end of the valve stem 41 has a male thread 41.
A valve rod (valve body) 41 is detachably attached to the spool 5 by screwing the male screw 41c into the female screw 5a of the spool 5.

In addition, when not measuring, as shown in FIG.
A, 4b→return holes 10a, 10b and a circulation path returning to each stock solution tank is formed. In addition, at the time of measurement, as shown in FIG.
10b is blocked by the rod 4 and no circulation path is formed, but a circuit is formed from the injection nozzles 6a and 6b to the flow paths 48a and 48b to the supply holes 44a and 44b to the metering device. There is.

In the mixing head constructed as above,
To measure the stock solution, first attach the measuring attachment 40 to the head body 1a of the mixing head 1. To install, attach the attachment body 40a.
The concave part 40b of the valve head body 1a is fitted into the convex part 1b of the head body 1a, and the valve stem 4 is fixed with a bolt.
The valve rod 41 is attached to the spool 5 by screwing the male thread 41c of the valve rod 41 into the male thread 5a of the spool 5.

Next, actuate a hydraulic cylinder (not shown),
As shown in FIG. 2, the spool 5 (valve stem 41) is moved back by a predetermined distance. Then, the injection nozzles 6a, 6b, the flow paths 48a, 48b, and the supply holes 44a, 44b communicate with each other, and each stock solution is sent to the metering device without being mixed. Then, the stock solution is supplied to the measuring device for a predetermined period of time, and after the predetermined period of time, the spool 5 is advanced to the forward end to complete the measurement. Based on this measured value, the flow rate of each component is adjusted and corrected to match the target value. When the attachment main body 40a and the valve stem 41 are finally removed after the adjustment is completed, the stock solution is always supplied into the mold at a constant ratio and at a constant flow rate. The discharge amount is increased or decreased by setting the timer.

In this way, when measuring the stock solution, the valve stem 41 is the only movable part attached to the spool 5, so the movable part can be made much smaller and lighter than the conventional metering nozzle 20.
Therefore, the inertial force that acts on the attachment portion of the valve stem 41 to the spool 5 at the time of stopping and starting the reciprocating motion can be reduced. Therefore, not only when the diameter of the spool 5 is large, but even when the diameter of the spool 5 is small, the metering attachment 40 having the above structure can sufficiently withstand the inertial force of the valve stem 41, which is a movable part. This makes it possible to increase the durability of the weighing attachment 40.

In addition, since the movable parts can be sufficiently lightened as described above, the thickness of the sprayed parts Y1 and Y2 of the partition part 41a where the stock liquid collides with the partition part 41a of the valve rod 41 from the injection nozzles 6a and 6b There is no need to make it thin, and therefore the durability of the sprayed portions Y1 and Y2 can be increased by providing a sufficient thickness.

In the above embodiment, the structure of the mixing head 1 shown in FIGS. 1 to 3 was taken as an example, and a structure in which the measuring attachment 40 is attached was explained, but the mixing head 1 is not limited to these. Instead, it may have a structure as shown in FIG. 4, for example. In FIG. 4, 60 is a mixing head, 61 is a sliding hole in the head body 60a, and 6 is a mixing head.
2 is a spool, 62a, 62b are circulation grooves, 63
A and 63b are injection nozzles, 64a and 64b are return holes, and their respective functions are the same as those of the above embodiment.

[Effect of idea]

In the metering attachment for the reaction injection molding machine of this invention, the attachment body is detachably attached to the mixing head body, and a guide hole is formed in the attachment body, and
The valve body, which is removably attached to the spool of the mixing head, is slidably and fluid-tightly fitted into the guide hole, so the structure is simple and the movable parts can be made lighter and smaller. can. For this reason, even if the diameter of the mixing head spool is large, but especially if it is small,
The mounting rigidity of the valve body can be increased, and the structure for mounting the valve body can have sufficient durability against the inertial force of the valve body. Further, there are excellent effects such as being able to improve the durability of the valve body itself.

[Brief explanation of the drawing]

Figures 1 to 3 show one embodiment of this invention; Figure 1 is a vertical sectional view of the mixing head in which the stock solution is being circulated, and Figure 2 is the mixing head in the state where the stock solution is being measured. 3 is a longitudinal cross-sectional view of - of Fig. 2.
FIG. 4 is a partial vertical sectional view showing a modification of the mixing head. Figures 5 to 7 show conventional examples.
The figure shows the state in which the metering nozzle is attached to the spool, and is a partially cutaway plan view, FIG. 6 is a view taken along the - line in FIG. 5, and FIG. 7 is a front view of the metering nozzle. 1...Mixing head, 2...Sliding hole, 2a...Mixing chamber, 5...Spool, 40...Measuring attachment, 40a...Attachment body, 41...
Valve body, 42... Guide hole, 44a, 44b... Supply hole, 48a, 48b... Channel.

Claims (1)

[Scope of utility model registration request] An attachment body is detachably attached to the tip of the mixing head body in the injection direction, and when this attachment body is attached to the mixing head body, the attachment body is attached to the spool sliding hole of the mixing head body on approximately the same central axis. A guide hole is formed in the attachment body so as to communicate with each other, and a guide hole is fitted into the guide hole so as to be slidable in the axial direction. On the other hand, the valve body is provided with a detachable valve body and a plurality of supply holes that are communicated with a plurality of channels defined in the guide hole by the valve body and supply liquid plastic raw materials to the metering device. A measuring attachment for a reaction injection molding machine characterized by: