JPH07102599B2 - Mold temperature controller - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold temperature controller for properly controlling the temperature of a mold used in plastic injection molding.

[0002]

2. Description of the Related Art In injection molding of plastics, the temperature of a mold has a great influence on the accuracy of products. for that reason,
Various mold temperature controllers have heretofore been proposed in order to adjust the mold temperature to a predetermined value.

FIG. 5 shows an example of such a conventional mold temperature controller. A conventional mold temperature controller indicated by reference numeral 1 is surrounded by a one-dot chain line, and has a tank 3 containing a heater 2 and a pump unit 4. Here, the cooling water is supplied from the water supply side pipe CW1 of the cooling water pipe system CW,
Water is supplied to the tank 3 via the cooling water supply pipe line L1. The supplied cooling water passes through the tank 3, is heated, and is heated by the mold 5.
The temperature-controlled water for temperature control (referred to as water other than cooling water) is sent to the pump unit 4 via the pipe line L2.
The temperature-controlled water is provided with a head by the pump unit 4 and is sent to the mold 5 through the pipe L3 to heat the mold 5 (at this time, the temperature of the temperature-controlled water decreases), and the pipe L4. It is returned to the tank 3 via. On the other hand, when cooling, the solenoid valve 6 may be opened to connect the drain side pipe CW2 of the cooling water pipe system CW to the pipe line L5. This controls the temperature. Reference numerals 7 and 7 in FIG. 5 are manual valves for closing the pipe lines L3 and L4 when the mold 5 is replaced.

[0004]

However, the temperature-controlled water returned to the tank 3 by the line L4 while the operation of the mold temperature controller 1 is in the steady state, the tank 3 by the line L1.
If it is not sufficiently mixed with the cooling water supplied to, the water temperature of the temperature control water flowing through the pipe L3 will not be constant, and therefore the temperature of the mold cannot be adjusted to a desired value. In addition, after the temperature-controlled water and the cooling water merge, the temperature change on the downstream side is large. That is, the water temperature of the temperature control water flowing through the pipe line L3 is not constant, and the temperature control of the mold becomes defective.

Here, if the tank 3 is enlarged, the temperature fluctuation can be moderated. However, if the size of the tank 3 is increased, the size of the mold temperature controller 1 becomes large, which is contrary to the basic design requirement that the mold temperature controller be compact.

The present invention has been proposed in view of the above-mentioned drawbacks of the prior art, and it is desirable to control the temperature of water to be supplied to a mold without increasing the tank capacity for mixing and hence the size of the entire apparatus. It is an object of the present invention to provide a mold temperature controller that can maintain a constant temperature.

[0007]

A mold temperature controller according to the present invention comprises a tank for temporarily storing temperature-controlled water, a pump unit for supplying the temperature-controlled water to the mold, the tank, a pump unit, A temperature control water pipe system that connects the mold, a cooling water supply pipe line that supplies cooling water from the cooling water pipe system, a cooling water discharge pipe from the tank to the cooling water pipe system, and an automatic temperature control valve on the way. In a mold temperature controller having a cooling water return pipe provided, the temperature control water piping system is a branched flow for bypassing a part of the temperature control water from the pump unit to the tank without passing through the mold. The branch flow pipe is bent downward in the tank, and the temperature control pipe for introducing the temperature control water returning from the mold into the tank is at its end and in the vicinity of the side wall of the tank. A notch and a baffle plate are provided on the cooling water supply line. The tank is configured to be completely agitated by the temperature regulating water means for dispersing is provided with a temperature control water when returning into the tank.

In the mold temperature controller of the present invention,
It is preferable that the temperature-controlled water returned to the tank forms a circulating flow.

In the practice of the present invention, it is preferable that the tank has a cylindrical shape, and that the pipe for returning the temperature-controlled water into the tank is attached so as to be inclined on the outer peripheral surface of the tank.
Since the temperature control water is injected substantially tangentially to the center line of the tank and the circumferential surface of the tank by mounting the pipe in an inclined manner, it promotes complete stirring in the tank. is there.

Further, the temperature-controlled water returned to the inside of the tank by either the temperature-controlled water return conduit or the branch flow conduit is injected in the axial direction of the cylindrical tank or the side portion of the tank is curved. It is preferably injected tangentially to the surface.

Here, the tank is preferably formed in a columnar shape or a prismatic shape, but what kind of shape the tank has as long as complete stirring can be performed by temperature control water returning to the inside of the tank. It may be.

A partition plate is provided in the tank in connection with the generation of the vertical swirling flow, and the upper side and the lower side of the partition side are separated from the upper surface and the bottom surface of the tank, It is also preferable that the inlet for returning the temperature-controlled water to the tank is provided at two or more places. It is also preferable that the two tanks are connected at their upper and lower parts by pipes, and each tank is provided with one or more inlets for temperature control water. This is because a vertical swirling flow is generated in any case.

The mold temperature controller of the present invention may be constructed such that a heater is built in the tank and the mold heats the temperature-controlled water by the heater. A heater may not be built in the tank, and the water temperature of the temperature control water may be lowered by cooling water to cool the mold.

[0014]

Therefore, the cooling water and the temperature-controlled water in the tank are injected as jet energy in a proper direction as the stirring energy for completely stirring the head of the temperature-controlled water returned into the tank, and are used as a backing water. Mixing, that is, complete stirring is performed. Then, the cooling water and the temperature-controlled water are instantly and uniformly mixed without being unevenly distributed in the tank, and the temperature change at the time of mixing becomes gentle. Therefore, the water temperature of the temperature control water supplied to the mold can be maintained at a desired constant value without increasing the size of the tank, and the quality of the product molded by the mold is also improved. Here, the head is a concept including a velocity head and a pressure head.

In the present invention, in the temperature control water piping system, in addition to the temperature control water conduit for introducing the temperature control water returning from the mold into the tank, a part of the temperature control water is transferred from the pump unit to the mold. Since it has a branch flow line that bypasses to the tank without passing through it, it is possible to convert all pressure heads given by the pump unit into high speed heads, and the speed heads effectively agitate the inside of the tank. Therefore, the energy can be effectively used. That is, the branch flow pipe is attached to the outer peripheral portion of the tank at an appropriate position and angle, and the temperature-controlled water flowing therein is returned to the inside of the tank, whereby the complete stirring in the tank is sufficiently performed.

Further, in the present invention, the temperature-controlled water returned to the tank forms a circulating swirling flow, and the swirling flow promotes complete stirring in the tank.

[0017]

Embodiments of the present invention will be described below with reference to the accompanying drawings. In the drawings, the same members are denoted by the same reference numerals.

In FIG. 1, the basic structure of the mold temperature controller 10 of the present invention, which is surrounded by an alternate long and short dash line, is similar to that of the conventional mold temperature controller 1 shown in FIG.

Cylindrical tank 12 of mold temperature controller 10
Includes a heater 14, and cooling water is supplied from a water supply side pipe CW1 of the cooling water pipe system CW through a pipe line 16. The cooling water supplied into the tank 12 is
The temperature-controlled water returned to the inside is uniformly mixed in a manner described later, and if necessary, heated by the heater 14 and sucked into the pump unit 20 as temperature-controlled water via the pipe 18. This temperature-controlled water is provided with the necessary pressure head by the pump unit 20 to heat the mold 24 via the line 22, and is returned to the tank 12 via the line 26.
When the mold temperature controller 10 is used as a cooling water supply mechanism for the mold 24, the heater 14 may be omitted.

The temperature-controlled water that has passed through the pipeline 26 is stored in the tank 12.
It is poured into and stirred inside. On the other hand, the above-mentioned conduit 22 is provided on the protruding side of the pump unit 20,
It branches to 0. Only a predetermined amount, for example, 5% to 15%, of the temperature-controlled water projected from the pump unit 20 flows through the branch flow pipe 30 in the branch flow pipe 30. Then, the temperature-controlled water bypassed by the branch flow pipe 30 is returned to the tank 12 to stir the inside of the tank.

In FIG. 1, reference numerals 36 and 38 respectively denote manual valves. When the mold 24 is replaced, the manual valves 36 and 38 are closed so as to be disconnected from the pipe lines 22 and 26. In this case, if the minimum flow pipe is provided, the mold 24 can be replaced without stopping the operation of the pump unit 20.

The cooling water supplied into the tank by the pipe 16 is instantaneously and uniformly mixed or stirred by the temperature-controlled water returned by the pipe 26 and the branch flow pipe 30 (complete stirring). As a result, the temperature change that occurs when the cooling water and the temperature-controlled water are mixed is moderated, and the temperature of the temperature-controlled water supplied from the conduit 22 to the mold 24 is maintained at a predetermined value. As a result, the dimensional accuracy and quality of the article molded by the mold 24 are improved.

The temperature-controlled water returned from the tank 12 to the drain-side pipe CW2 of the cooling-water pipe system CW flows through the pipe line 38 provided with the automatic temperature control valve 36.

It is also possible to omit the branch flow line 30 in order to achieve complete stirring in the tank 12 only by the temperature-controlled water returning from the line 26. However, the temperature and energy of the temperature control water flowing through the pipe 26 may vary depending on how the mold 24 is. Therefore, in the illustrated embodiment, the branch flow pipe 30 is provided as the minimum flow pipe. This is because the branch flow pipe 30 is provided on the discharge side of the pump unit 20, and the pressure head of the water flowing therethrough is high and easy to use.

In FIG. 1, reference numeral 40 is a temperature sensor. The temperature sensor 40 can be provided not only inside the tank 12 but also in the vicinity of the pipe line 18, the pump unit 20, etc., and it is preferable to provide it near the tank 12 as much as possible.

In order to achieve complete stirring in the tank 12, the manner in which the pipe line 26 and the branch flow pipe line 30 are attached to the tank 12 is important.

FIG. 2 shows in detail how the various pipes are attached to the tank 12.

In FIG. 2, a dispersion plate 156 is attached to the pipe 16 for supplying the cooling water to the tank 12 as a means for dispersing the supplied cooling water in three directions. A similar effect (effect of evenly diffusing in the tank 12) may be achieved by using a means other than the dispersion plate 156.

The temperature-controlled water supplied from the tank 12 to the pump unit 20 (see FIG. 1) via the pipe 18 passes through the mold 24 (see FIG. 1) to the tank 12 via the pipe 26. Will be returned. A cutout 155 is formed at the end of the conduit 26, and a baffle plate 154 is attached. With the cutout portion 155 and the baffle plate 154,
The return-temperature controlled water flows upward in FIG. 2 in the vicinity of the side wall of the tank 12. On the other hand, the tip end portion 153 of the branch flow pipe line 30 faces downward in FIG. Thereby, the temperature-controlled water returned to the inside of the tank 12 through the pipe line 26 and the branch flow pipe line 30 is uniformly stirred in the tank 12, and the water temperature of the temperature-controlled water is maintained at a desired constant value. Can be done.

3 and 4 show a modified example of the tank 12. In this tank, the temperature-controlled water circulates by a swirling flow as indicated by the dotted arrow in FIG.

The invention is not limited to the embodiments described above. For example, in the present invention, the discharge location is from the tank in the embodiment, but it may be anywhere. If cooling water injection is provided in the pipe upstream of the tank, it is not ideal, but not impossible, between that position and the tank. The position of the temperature sensor is preferably the tank or the tank downstream of the tank close to the tank. Further, an oil medium can be used by providing a heat exchanger (for example, a flexible pipe in the tank) for exchanging heat between the cooling water and the oil in the tank or in the upstream.

In addition to this, the tank used in the present invention can be used regardless of the direction such as vertical, horizontal, or diagonal. In addition, it is preferable that the cooling water is injected into the tank or upstream of the tank close to the tank.

[0033]

As described above, according to the present invention,
Since the inside of the tank is completely stirred by the temperature-controlled water returned to the tank and the cooling water supplied to the tank, the temperature of the temperature-controlled water supplied to the mold is also maintained at a predetermined value. Therefore, the temperature of the mold is maintained at a desired value, and the quality of the molded product is improved.

Further, since the line flow does not occur even in a small tank, the temperature of the temperature-controlled water becomes stable.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a mold temperature controller of the present invention.

FIG. 2 is a perspective view illustrating an embodiment of a tank used in the present invention.

FIG. 3 is a front view showing another embodiment of the tank used in the present invention.

FIG. 4 is a side view of the tank shown in FIG.

FIG. 5 is a block diagram of a conventional mold temperature controller.

[Explanation of symbols]

 10 ... Mold temperature controller 12 ... Tank 14 ... Heater 20 ... Pump unit 24 ... Mold CW ... Cooling water piping system 16, 18, 22, 26, 38 ... -Pipe line 30 ... Branch flow line 153 ... Tip part of branch flow line 154 ... Baffle plate 155 ... Notch part 156 ... Dispersion plate

Claims (2)

[Claims] 1. A tank for temporarily storing temperature-controlled water, a pump unit for supplying the temperature-controlled water to a mold, the tank,
Temperature control water pipe system connecting pump unit and mold, cooling water supply pipe line for supplying cooling water from the cooling water pipe system, cooling water is discharged from the tank to the cooling water pipe system, and temperature is adjusted in the middle In a mold temperature controller having a cooling water return pipe line provided with an automatic valve, the temperature control water piping system bypasses a part of the temperature control water from the pump unit to the tank without passing through the mold. Has a branch flow pipe which is bent downward in the tank, and the temperature control water pipe for introducing the temperature control water returning from the mold into the tank is at its end and A notch and a baffle plate are provided near the side wall of the tank.
The cooling water supply pipe is provided with a means for dispersing the cooling water, and when returning the temperature-controlled water into the tank, the temperature-controlled water completely agitates the inside of the tank. A mold temperature controller characterized in that 2. The mold temperature controller according to claim 1, wherein the temperature-controlled water returned to the inside of the tank forms a circulating flow.