JP4374125B2 - Temperature control device for mold - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a temperature control device for a mold.
[0002]
[Prior art]
Conventionally, the following is known as a temperature control device for this type of mold. A mold having a liquid passage, a temperature controller having a heater and a liquid passage, and a liquid circulation pump, which constitute a liquid circulation path, are applied to the liquid circulation path at a predetermined pressure. It is known that a liquid supply source for supplying pressurized room-temperature liquid is connected via a liquid supply conduit and a drain pipe having an open / close valve interposed in the middle of the liquid circulation path. Yes.
[0003]
[Disadvantages of the prior art]
The conventional temperature control device for molds has the following drawbacks.
When the normal temperature liquid is supplied into the liquid circulation path from the liquid supply source while the on-off valve is opened to discharge the liquid in the liquid circulation path, the discharged high-temperature liquid (for example, 100 degrees Celsius to 120 degrees Celsius). Liquid), the scale component contained in the liquid separates from the vapor and adheres to the valve seat and valve body of the on-off valve, which prevents the on-off valve from closing completely. There was a drawback.
[0004]
[Means for eliminating the above-mentioned drawbacks]
The present invention employs the following means in order to eliminate the above disadvantages.
The invention of claim 1 includes a mold having a liquid passage, a temperature controller having a heater and a liquid passage, and a liquid circulation pump, which constitute a liquid circulation path. A liquid supply source for supplying a normal temperature liquid pressurized at a predetermined pressure to the circulation path is connected via a liquid supply conduit, and a drain pipe having an on-off valve interposed in the middle of the liquid circulation path. In the mold temperature control apparatus, the drain pipe upstream of the on-off valve and the liquid supply conduit are connected by a throttle passage.
[0005]
【The invention's effect】
The present invention has the following effects by the configuration as described above.
According to the first aspect of the present invention, when the on-off valve is opened, the liquid at normal temperature (from the liquid supply source) is mixed into the high-temperature liquid in the liquid circulation path through the throttle passage, and the on-off valve Since the temperature of the liquid passing through the valve is reduced to prevent generation of vapor, it is possible to prevent the scale components from adhering to the valve seat and valve body of the on-off valve, and as a result, the on-off valve is completely closed. The trouble of disappearing can be prevented.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below.
The temperature controller 2 includes a return conduit 7 having a rod-shaped heater 67 inside, and an outward conduit 6 having a rod-shaped heater 67 inside.
[0007]
The outlet of the return conduit 7 and the suction port 72 of the liquid circulation pump 71 are connected by a conduit 68, and the inlet of the outward conduit 6 and the discharge port 73 of the liquid circulation pump 71 are connected by a conduit 69.
[0008]
A float chamber 11 is connected to the return conduit 7 via a conduit 19, and a float switch 12 is provided in the float chamber 11.
The float switch 12 includes a guide bar 14 provided vertically in the float chamber 11, and a float 15 that can be raised and lowered along the guide bar 14.
A magnet (not shown) is provided on the float 15, and a switch (not shown) such as a reed switch that is actuated by the magnet of the float 15 when the float 15 is located at the uppermost position is provided on the upper portion of the guide rod 14. Yes.
With such a configuration, it is possible to know that the float 15 is pushed up by the liquid in the “ON” state and located at the uppermost position or in the vicinity thereof, while the float 15 is in the liquid state when the switch is “OFF”. It is possible to know that it has fallen out of the uppermost position or its vicinity. This makes it possible to know that the liquid in the return conduit 7 has decreased. An alarm is issued when the switch is in the “OFF” state.
[0009]
An outbound conduit 25 having a check valve 24 (which prevents the flow toward the outbound conduit 6) in the middle of the outlet of the outbound conduit 6 and an inlet of a resin molding die 26 having a liquid passage (not shown). Connected through.
The float chamber 11 and the outlet of the mold 26 are connected via a return conduit 27.
With such a configuration, a liquid circulation path (hereinafter simply referred to as a liquid circulation path) including the liquid circulation pump 71, the forward conduit 6, the mold 26, and the return conduit 7 is configured.
[0010]
A side of the outward conduit 25 closer to the outward conduit 6 than the check valve 24 is connected to the return conduit 27 via a bypass conduit 29. A variable flow control valve 30 is provided in the middle of the bypass conduit 29.
The bypass conduit 29 adjusts the amount of liquid flowing into the mold 26 by causing a flow rate corresponding to the degree of opening of the flow rate adjusting valve 30 to be short-circuited from the forward conduit 25 to the return conduit 27.
[0011]
A liquid supply source 43 that supplies a liquid at room temperature pressurized at a predetermined pressure is connected to the float chamber 11 via a liquid supply conduit 42. An open / close valve 38 (including an electromagnetic open / close valve) is interposed in the conduit 42. The on-off valve 38 is always open during normal operation.
A relief valve 44 is connected to the conduit 42 between the on-off valve 38 and the float chamber 11 to release the pressure when the pressure in that portion becomes an abnormal pressure higher than a set value.
[0012]
A drainage pipe 51 whose downstream side is open to the atmosphere is connected to the float chamber 11, and an opening / closing valve 49 having an inlet 49 a and an outlet 49 b is interposed in the drainage pipe 51. The drainage pipe 51 upstream of the on- off valve 49 ( drainage pipe 51 between the on-off valve 49 and the float chamber 11) and the conduit 42 between the on-off valve 38 and the float chamber 11 pass through the throttle passage 46. It has connected via the conduit | pipe 45 which has. With such a configuration, the normal pressure liquid from the liquid supply source 43 is guided to the inlet 49 a side of the on-off valve 49 through the on-off valve 38 that is always open during normal operation.
[0013]
A pressure air source 83 is connected to the forward conduit 25 downstream of the check valve 24 (on the mold 20 side) via a conduit 82 having an on-off valve 80 and a check valve 81 on the way. The check valve 81 prevents the flow toward the pressurized air source 83.
[0014]
Method of using the embodiment of the invention
Next, a method of using the embodiment of the invention will be described.
First, an operation for starting operation, that is, an operation for filling the liquid circulation path with liquid will be described.
The on-off valve 80 is closed. Further, the flow control valve 30 is opened a little.
In this state, when the on-off valve 38 and on-off valve 49 are opened, the liquid is supplied from the liquid supply source 43 to the liquid circulation path through the on-off valve 38 and the float chamber 11.
The air in the liquid circulation path is discharged from the drain pipe 51 through the float chamber 11 and the on-off valve 49. When the liquid circulation path is almost filled with the liquid, the liquid circulation pump 71 is operated in the above state, and the liquid is discharged from the drain pipe 51 together with the air.
Then, when the float 15 stops moving up and down, it is known that the liquid is filled in the liquid circulation path.
Thereafter, the on-off valve 49 is closed. The on-off valve 38 is held open.
[0015]
After such preparation, the rod-shaped heater 67 is turned “ON” and the injection molding machine is operated to stabilize the product quality, and then the main operation (normal operation) is performed. The liquid circulates in the liquid circulation path by the liquid circulation pump 71. If necessary, a predetermined flow rate can be short-circuited from the forward conduit 25 to the return conduit 27 by adjusting the degree of opening of the flow control valve 30.
[0016]
During normal operation (during normal operation), even if liquid leaks from the liquid circulation path, it is automatically supplied from the liquid supply source 43 via the on-off valve 38 and the float chamber 11 without performing special control. Thus, the liquid circulation path can be always filled with liquid.
When the temperature of the liquid in the liquid circulation path has risen too much, the on-off valve 49 is opened to supply the room temperature liquid from the liquid supply source 43 while discharging the liquid in the liquid circulation path. At that time, the normal temperature liquid from the liquid supply source 43 is mixed with the high temperature liquid (about 100 degrees Celsius to about 120 degrees Celsius) discharged from the liquid circulation path through the throttle passage 46, and thus passes through the on-off valve 49. The temperature of the liquid can be lowered so that no vapor is generated.
[0017]
[Variations]
A description will be given below of modifications and the like.
(1) The on-off valve 38 and the on-off valve 49 may be manual on-off valves.
(2) The throttle passage 46 may be capable of adjusting the flow rate.
(3) A strainer or the like may be used as necessary.
(4) The heater is not limited to a rod shape. Further, at least one heater may be used.
[Brief description of the drawings]
FIG. 1 is a system diagram showing an embodiment of the present invention.
[Explanation of symbols]
2 Temperature controller 26 Mold 42 Liquid supply conduit 43 Liquid supply source 49 On-off valve 51 Drain pipe 67 Bar heater 71 Liquid circulation pump

Claims (1)

A mold having a liquid passage, a temperature controller having a heater and a liquid passage, and a liquid circulation pump, which constitute a liquid circulation path, are applied to the liquid circulation path at a predetermined pressure. Temperature for a mold in which a liquid supply source for supplying pressurized room-temperature liquid is connected via a liquid supply conduit and a drain pipe having an on-off valve interposed in the liquid circulation path is connected In the adjusting device, a temperature adjusting device for a mold, wherein a drain pipe upstream of the on-off valve and a liquid supply conduit are connected by a throttle passage.

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