JP3078397B2 - Multi-component synthetic resin mixing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a method of mixing two or more chemically reacting resin components such as polyurethane resin and pressing the mixture into a mold in which a core material such as a glass mat or a reinforcing material is disposed. The present invention relates to an apparatus for mixing a multi-component synthetic resin.

[0002]

2. Description of the Related Art For example, in a molding process of a polyurethane resin, a mixing apparatus is used in which a plurality of chemically reacting resin components are injected into a mixing chamber, mixed, stirred and discharged into a predetermined mold.

As this type of mixing apparatus, a nozzle is provided at an inlet of a mixing chamber, a resin component supply flow path and a resin component return flow path are provided in front of the nozzle, and a resin component return flow path is provided in the resin component return flow path. Is known in which a fully closed valve is provided, and a cleaning rod is provided in the mixing chamber in a reciprocating manner.

[0004] The mixing device, when mixing and discharging the resin component,
The fully closed valve of the resin component return flow path closes to stop the return of the resin component, and the cleaning rod retreats to open the inlet. Thereby, the resin component is injected into the mixing chamber from the injection port through the nozzle, is subjected to collision mixing, and is discharged into the mold. At this time, if a reinforcing material such as a glass fiber mat is present in the mold, it hinders the ejection of the mixed resin component into the mold,
The mixed resin component is pressed into the mold at a high pressure, and a high pressure is applied between the injection port of the mixing chamber and the inside of the mold.

On the other hand, after the press-fitting, the cleaning rod advances to close the nozzle of the injection port, and at the same time, the fully closed valve of the resin component return flow path is opened. Thereby, the resin component flows from the resin component supply flow path to the resin component return flow path before the nozzle without passing through the nozzle, and reaches the respective resin component tanks. The cleaning rod also has the function of cleaning the mixed resin component adhered to the inner peripheral surface of the mixing chamber when the mixed resin component is discharged, when reciprocating.

[0006]

However, in the mixing apparatus described above, since the resin component is sent out from the storage tank by applying pressure to the resin component, when the flow of the resin component is stopped by stopping the apparatus, the resin component is stopped. The pressure in the supply channel, the nozzle, and the entire resin component return channel decreases. Therefore, there is a problem that the resin component adheres to the cleaning rod at the time of press-fitting in the mold, and the resin component located near the injection port of the mixing chamber together with the cleaning rod when the apparatus is stopped enters the nozzle due to the pressure drop near the nozzle and clogs the nozzle. is there.

On-off valves such as fully-closed valves which operate quickly to prevent the adverse effects of prolonged state changes during opening and closing are used. On the other hand, since the cleaning rod reciprocates while sliding on the inner peripheral surface of the mixing chamber, its operation time is usually longer than the operation time of the fully closed valve. Therefore, before the cleaning rod advances and completely closes the injection port, the fully closed valve of the resin component return flow path is opened, and the resin component sent from the resin component supply flow path to the nozzle is filled with the resin component before the nozzle. The flow returns to both of the return flow paths. As a result, the pressure in the nozzle portion temporarily drops, and the mixed resin component once pressurized into the mold at a high pressure instantaneously flows back into the nozzle due to the pressure drop in the nozzle portion and the pressure in the mold, causing the nozzle to flow. There is a risk of clogging.

Accordingly, the present invention relates to a multi-component synthetic resin mixing apparatus for press-fitting a mixed resin component into a mold. The mixed resin component adhered to a cleaning rod does not enter the nozzle when the flow of the resin component is stopped. It is an object of the present invention to provide a mixing device and a mixing device capable of preventing a mixed resin component from entering the nozzle at the end of press-fitting into a mold.

[0009]

According to the present invention, there is provided a cleaning rod which reciprocates in a mixing chamber, an injection port which is opened and closed by the reciprocation of the cleaning rod, and a nozzle provided in the injection port. Has a resin component supply flow path and a resin component return flow path that communicates with the nozzle, and has a fully closed valve in the resin component return flow path, and has two or more types of chemically reacting resin components. In the multi-component synthetic resin mixing apparatus for injecting and mixing into the mixing chamber from the nozzle of the injection port, a check valve is provided in the resin component supply flow path, and a pressure control valve is provided in the resin component return flow path. The present invention relates to an apparatus for mixing a multi-component synthetic resin.

According to the present invention, in addition to the check valve and the pressure regulating valve, after the injection of the resin component is completed, the cleaning rod first closes the injection port of the mixing chamber, and then the fully closed valve is opened. The present invention relates to an apparatus for mixing a multi-component synthetic resin.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a schematic diagram of a multi-component synthetic resin mixing apparatus according to one embodiment of the present invention, FIG. 2 is a cross-sectional view showing different operating states of a mixing head portion in the embodiment in left and right, and FIG.
FIG. 4 is a diagram showing a relationship between operation and pressure in the embodiment. The multi-component synthetic resin mixing apparatus of this embodiment is used for mixing polyurethane resin components.

The mixing apparatus 10 according to this embodiment includes a mixing head 12, nozzles 14 and 16, and a cleaning rod 1.
8, resin component supply channels 20, 22, resin component return channel 2
4, 26, check valves 28, 30, pressure regulating valves 32, 34,
It has pressure switches 36 and 38 and fully closed valves 40 and 42.

The mixing head 12 has a polyol component inlet 46 and an isocyanate component inlet 48 toward the mixing chamber 44, and the nozzles 1 are provided at the inlets 46 and 48.
4, 16 are fitted.

The nozzles 14 and 16 are used to adjust the collision flow rate when the polyol component and the isocyanate component are simultaneously injected into the mixing chamber 44 and subjected to collision mixing, with the tips directed toward the injection ports 46 and 48. Open.

The cleaning rod 18 is connected to the injection port 4.
6, 48 are opened and closed. The cleaning rod 18 has a piston 50 whose rear portion moves forward and backward by hydraulic pressure.
When the piston 50 moves forward and backward, the piston 50 reciprocates while sliding on the inner peripheral surface of the mixing chamber 44 to open and close the injection ports 46 and 48. Reference numeral 49 denotes a switching valve for moving the piston 50 of the cleaning rod 18 forward and backward.

The one resin component supply flow path 20 exits from the polyol component storage tank 52, passes through the liquid supply cylinder 54, passes one nozzle 14, and communicates with the resin component return flow path 24. The resin component return flow path 24 reaches the polyol component storage tank 52. The other resin component supply channel 22 is provided in the isocyanate component storage tank 5.
6, passes through the liquid sending cylinder 58, passes through the other nozzle 16, and communicates with the resin component return flow path 26. The resin component return channel 26 reaches the isocyanate component storage tank 56. In addition, the resin component supply flow path 2
0, 22 and the resin component return flow paths 24, 26 and the nozzles 14, 16 are communicated with each other by flow paths in the mixing head. The resin component supply flow paths 22 and 24 from the mixing head 12 to the storage tanks 52 and 56 and the resin component return flow path 2
Reference numerals 4 and 26 are constituted by pipes.

The resin component supply flow paths 20 and 22 have check valves 28 and 30 near the nozzles 14 and 16, respectively. The check valves 28 and 30 are connected to the nozzle 1 from the check valves 28 and 30.
When the pressure in the series of flow passages reaching the pressure regulating valves 32 and 34 of the resin component return flow passages 24 and 26 via the fronts of the nozzles 4 and 16 increases once, the pressure is reversed, that is, the nozzle 1
There is an action to prevent escape from the vicinity of 4, 16 toward the later-described pressure feeding cylinders 54, 58. Incidentally, it is preferable to the spring pressure of the check valve 28, 30 of the resin supply passage as low as possible, in this embodiment is set to open at 0.5 kg / cm ^2.

The resin component return flow paths 24, 26 have pressure regulating valves 32, 34, pressure switches 36, 38,
Throttle valves 60 and 62 and fully closed valves 40 and 42 are provided. The pressure regulating valves 32 and 34 are formed of known spring-loaded valves near the nozzles 14 and 16. The pressure regulating valves 32, 34
Before the pressure of the resin component between the nozzles 14 and 16 and the pressure regulating valves 32 and 34 increases to a predetermined value, the resin component return flow path is controlled so that the resin component does not flow in any direction. The hardness of the spring is set so that the resin component flows only from the vicinity of the nozzles 14 and 16 to the storage tanks 52 and 56 only when the pressure of the resin component is equal to or higher than a predetermined value. In this example, 20 kg /
cm ² is set.

The pressure switches 36, 38 sense the point in time when the pressures in the resin component return passages 24, 26 reach a predetermined pressure, and actuate the fully closed valve switching valve 43, thereby causing the fully closed valves 40, 42. And a known switch.

The fully-closed valves 40 and 42 are used to return the resin component return passages 24 and 26 when the resin component is mixed and injected (when the resin component is pressed into the mold).
To open the resin component return passages 24 and 26 when the other resin component is circulating (when not press-fitted), and comprises a hydraulic cylinder device or the like, and is opened and closed by a fully closed valve switching valve 43. The throttle valves 60 and 62 are for adjusting the pressure of the resin component so that it is substantially equal between the time of discharge and the time of circulation.

Next, the operation of the mixing apparatus 10 will be described with reference to FIG.
This will be described with reference to FIG. The vertical axis in FIG. 3 indicates the pressure at the fully closed valve 40 in the resin component return flow path 24 on the polyol component side.

First, in the mixing apparatus 10, as shown in the left side of FIG. 2, the cleaning rod 18 is lowered (advanced) to close the injection ports 46 and 48 of the mixing chamber 44 and completely close the resin component return flow path. The valves 40 and 42 are opened. Then, in that state, the liquid sending cylinder 54,
The polyol component and the isocyanate component (resin component) are sent out from the storage tanks 52 and 56 to the resin component supply flow paths 20 and 22 from the respective storage tanks 52 and 56. Resin component supply channel 2
The polyol component and the isocyanate component sent out to the nozzles 0 and 22 do not pass through the nozzles 14 and 16 of the injection ports 46 and 48 because the injection ports 46 and 48 of the mixing chamber 44 are closed by the cleaning rod 18. Flowing into the resin component return flow paths 24 and 26 just before 14 and 16 and stopped by the pressure regulating valves 32 and 34.

The pressure of the resin components accumulated near the pressure control valves 32 and 34 is increased by the resin components sent toward the pressure control valves 32 and 34 thereafter. Then, when the pressure of the resin component in the vicinity of the pressure control valves 32 and 34 reaches a predetermined value, the pressure control valves 32 and 34 are switched to the nozzles 14 and 1.
6 open in the direction of the storage tanks 52, 54. As a result, the resin component starts to flow toward each of the storage tanks 52 and 56, so that the resin component circulates continuously. The pressure of the resin component becomes constant at the time point A when the constant condition is satisfied. The pressure of the resin component is limited by the restrictors 60 and 62 of the resin component return flow path.

At the time point A when the pressure of the resin component becomes constant, the cleaning rod 18 rises (retreats) to open the injection ports 46 and 48 and to close the fully closed valves 40 and 40 in the resin component return flow path. 42 is closed. Thereby,
The polyol component and the isocyanate component are injected into the injection ports 46, 4
8 and injected into the mixing chamber 44 and subjected to collision mixing. Then, the mixed resin component is pressed into the cavity of the mold 64 from the tip of the mixing head 12. During this press-fitting, the pressure of the resin component increases because the resin component return flow path is closed by the fully closed valves 40 and 42. Further, a reinforcing material 66 such as a glass fiber mat is arranged in the cavity in advance, and the pressure of the resin component also increases due to resistance when the mixed resin component is pressed into the reinforcing material 66 or the narrow cavity space. .

Next, at the scheduled end point B of the in-mold injection of the mixed resin component, the cleaning rod 18 is lowered (advanced), the injection ports 46 and 48 of the mixing chamber 44 are closed, and the mixed injection of the resin component is stopped. After that, the resin component is sent by the liquid sending cylinders 54 and 58, and since the fully closed valves 40 and 42 are closed, the pressure of the resin component increases.

It should be noted that it takes a little time for the cleaning rod 18 to completely descend from the start of the descent and close the injection port, during which time the injection ports 46 and 48 remain open. However, since the fully closed valves 40 and 42 are closed, the resin component does not flow to the resin component return channels 24 and 26, and the entire amount passes through the nozzles 14 and 16 and the injection ports 46 and 48.
Flows to As a result, the pressure does not drop at the nozzles 14 and 16, and the mixed resin component once injected into the mold flows backward due to the pressure in the cavity, so that the injection ports 46 and 4 do not flow.
There is no risk of intrusion from nozzle 8 toward nozzles 14 and 16.

When the pressure of the resin component reaches the set pressure C, the pressure switches 36 and 38 of the resin component return passages 24 and 26 are turned on, and the fully closed valves 40 and 42 are opened. As a result, the resin component that has been blocked by the fully closed valves 40 and 42 returns to the storage tanks 52 and 56 through the resin component return channels 24 and 26, and is continuously circulated. As a result, the pressure of the resin component decreases and becomes constant at point D.

At the point D, the advance of the liquid feeding cylinders 54 and 58 is completed, and then the apparatus 10 is stopped. As a result, the flow (circulation) of the resin component gradually stops, and the pressure gradually decreases. At the point E at which the pressure of the resin component has decreased to a preset value, the pressure regulating valves 32 and 34 of the resin component return passages 24 and 26 are operated, and the storage tanks 54 and 56 are again returned from just before the nozzles 14 and 16. Thus, the flow of the entire resin component toward the resin is stopped. As a result, the pressure of the resin component between the check valves 28 and 30 of the resin component supply flow paths 20 and 22 and the pressure regulating valves 32 and 34 of the resin component return flow paths 24 and 26, that is, the pressure near the nozzles 14 and 16 Will be maintained at a constant high value.

At a constant pressure near the nozzle, the mixed resin component adhering to the outer peripheral surface of the cleaning rod 18 when the mixed resin component is pressed into the mold is injected into the nozzles 14 and 1.
6 is prevented from entering.

In the above embodiment, the pressure switch 3
6, 38, but using a timer in place of the pressure switch, and using the injection ports 46, 4 by the cylinder rod 18.
The fully closed valves 40 and 42 may be opened with a predetermined time delay after the closing of the valve 8. The delay time is determined according to the type of the resin component, the size of the cylinder rod, and the like.

In order to confirm the effect of the present invention, the check valves 28, 30 and the pressure regulating valves 32, 34 are eliminated, and the opening of the fully closed valves 40, 42 and the lowering (forward) of the cleaning rod 18 are simultaneously performed. In the case where the
The pressure was measured at the same position as the zero part. FIG. 4 is a view showing the pressure and operation, and corresponds to FIG. A,
b, d, and e correspond to A, B, D, and E in FIG.

As is apparent from FIG. 4, when the opening of the fully closed valve and the closing of the injection port due to the lowering of the cleaning rod are simultaneously started, the injection of the resin component is completed immediately after the completion of the injection mixing of the resin component. The pressure is reduced, and the mixed resin component once pressed into the mold may flow backward and enter the nozzle from the injection port. Further, at point e where the flow of the resin component is completely stopped, the pressure of the resin component becomes zero because there is no check valve and the pressure regulating valve, and the mixed resin component adhering to the cleaning rod outer peripheral surface at the time of press-fitting the mixed resin component is removed. There is a risk of intrusion into the nozzle.

[0033]

As described above, the multi-component synthetic resin mixing apparatus of the present invention is provided with a check valve and a pressure regulating valve, so that the mixed resin adhering to the cleaning rod when the mixed resin component is press-fitted in the mold. This has the effect of preventing components from entering the nozzle when the flow of the resin component stops and clogging the nozzle.

Further, when the fully closed valve provided in the resin component return flow path is opened after closing the injection port with the cleaning rod, the mixed resin component once pressed into the mold immediately after the completion of the press-fitting. This has the effect of preventing backflow and entry into the nozzle and clogging of the nozzle.

[Brief description of the drawings]

FIG. 1 is a schematic view of an apparatus for mixing a multi-component synthetic resin according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing different states of the mixing head unit in the same example on the left and right.

FIG. 3 is a diagram showing a relationship between operation and pressure in the embodiment.

FIG. 4 is a diagram showing the relationship between operation and pressure in a conventional device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 Multi-component synthetic resin mixing device 12 Mixing head 14 Nozzle 16 Nozzle 18 Cleaning rod 20 Resin component supply channel 22 Resin component supply channel 24 Resin component return channel 26 Resin component return channel 28 Check valve 30 Check valve 32 Pressure regulating valve 34 Pressure regulating valve 36 Pressure switch 38 Pressure switch 40 Fully closed valve 42 Fully closed valve 44 Mixing chamber 46 Inlet 48 Inlet

Claims (3)

(57) [Claims] 1. A cleaning rod that reciprocates in a mixing chamber, an injection port that opens and closes by reciprocation of the cleaning rod, and a nozzle provided in the injection port, and a resin component that communicates with the nozzle in front of the nozzle. A supply channel and a resin component return channel, and the resin component return channel has a fully closed valve to allow two or more types of chemically reacting resin components to be mixed from a nozzle of the injection port through a mixing chamber. A multi-component synthetic resin mixing apparatus for injecting and mixing into a multi-component synthetic resin, wherein a check valve is provided in the resin component supply flow path, and a pressure regulating valve is provided in the resin component return flow path. Synthetic resin mixing equipment. 2. The multi-component synthetic resin mixing device according to claim 1, wherein after the injection of the resin component is completed, the cleaning rod first closes the injection port of the mixing chamber, and then fully opens the valve. 3. The multi-component synthetic resin mixing device according to claim 2, wherein a pressure switch for detecting the pressure of the resin component and opening and closing the fully closed valve is provided in the resin component return flow path.