JPH0513710U - Mold temperature controller - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a mold temperature control device capable of automatically performing overload protection of a pump. [Structure] Feeding line 2 for heat medium through a pump 2c
And a temperature controller 3, 4 for cooling or heating the heat medium flowing through the feeding pipeline,
Since the pressure control valve 7 that holds the discharge pressure at a value lower than the overload pressure is provided on the discharge side of the pump 2c, even if the pressure loss of the mold to be temperature-controlled is large, the pump 2c is overloaded. Operates at a discharge pressure lower than the pressure, pump 2c
In addition, it is possible to reliably prevent failure and damage of temperature control equipment.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a mold temperature adjusting device that adjusts the temperature of a mold by sending a temperature-controlled heat medium to the mold.

[0002]

[Prior Art]

 As a mold temperature adjusting device of this type, there is one shown in FIG. This mold temperature control apparatus includes a movable box-shaped apparatus main body 1, a feeding pipe 2 for a heat medium (for example, water) arranged in the apparatus main body 1, and a feeding pipe 2 It is composed of a cooler 3 for cooling the heat medium flowing through, a heater 4 for heating the heat medium flowing through the feed pipe line 2, an outflow header 5, and an inflow header 6.

The feed line 2 has an inlet 2a and an outlet 2b protruding from the back surface of the apparatus main body 1, and a pump 2c is interposed near the outlet 2b. In addition, the middle of the pipeline is branched into two (2e, 2f) via a switching valve 2d, one branch pipeline 2e has a cooling chamber 2g, and a heating chamber 2h is provided upstream of the pump 2c. is doing.

The cooler 3 comprises a compressor 3a, a condenser 3b, an expansion valve 3c and an evaporation pipe 3d, and the evaporation pipe 3d is arranged in a cooling chamber 2g. Further, a blower 3e for cooling is arranged opposite to the condenser 3b. Further, the heater 4 comprises an electric heating heater 4a and a power source 4b, and the electric heating heater 4a is arranged in the heating chamber 2h.

The outflow header 5 has a plurality of (four in the figure) outflow ports 5 a, and is connected to the outlet 2 b of the feeding pipeline 2 and arranged on the back surface of the apparatus main body 1. Further, each of the outlets 5a is provided with a manual opening / closing valve 5b. Further, the inflow header 6 has a plurality (four in the figure) of inflow ports 6a, is connected to the inflow port 2b of the feeding pipeline 2, and is disposed on the back surface of the apparatus main body 1. Further, each of the outlets 5a is provided with a manual on-off valve 5b.

The mold temperature controller described above heats the outflow port 5 a of the outflow header 5 and the inflow port 6 a of the inflow header 6 in the temperature control passages 11 b formed in both mold plates 11 a of the mold 11. It is used by connecting through the adjusting line 12. The opening / closing valves 5b and 6b of both headers 5 and 6 are opened and closed as appropriate depending on the connection status of the temperature control conduit 12.

When heating the die 11 in the pre-stage of molding, the switching valve 2d may be switched to the side of the branch pipe 2f to operate the heater 4 and the pump 2c, and the heating chamber 2h is heated to a desired temperature. The heat medium thus separated is divided in the outflow header 5 and is sent from each outlet 5a to the temperature control passage 11b of both template plates 11a via the temperature control pipes 12. After passing through the temperature control passage 11b, the heat medium returns to the inflow port 6a of the inflow header 6 via the temperature control pipe 12, merges in the inflow header 6 and is heated and circulated again in the heating chamber 2h.

Further, when cooling the mold 11 at the time of molding, it is sufficient to switch the switching valve 2d to the side of the branch line 2e to operate the cooler 3 and the pump 2c, and the cooling chamber 2g cools down to a desired temperature. The heat medium is divided in the outflow header 5 and is sent from each outlet 5a to the temperature control passage 11b of both template plates 11a via the temperature control pipes 12. The heat medium after passing through the temperature control passage 11b returns to the inflow port 6a of the inflow header 6 via the temperature control pipe 12, merges in the inflow header 6 and is cooled and circulated again in the cooling chamber 2g.

[0009]

[Problems to be solved by the device]

 By the way, the discharge pressure of the pump 2c in the above-mentioned device largely fluctuates due to the pressure loss (passage resistance) of the temperature control passage 11b of the mold 11. FIG. 5 shows the relationship between pump capacity and die pressure loss. In the figure, T1 and T2 are pressure loss curves of dies having different specifications, and N1 is a capacity curve of the pump 2c. The pressure loss of the pump 2c is at the intersection A with the capacity curve N1 in the mold having a pressure loss of T1, and at the intersection B with the capacity curve N1 at the mold of T2 having a larger pressure loss. The larger the mold, the higher the operating point and the higher the discharge pressure of the pump 2c.

However, the pump usually has an upper limit that can be cut off as the discharge pressure, and if the pump is operated beyond this, there is a high risk of causing an overload and causing a failure. That is, in FIG. 5, when the overload pressure of the pump 2c is Pa, the operation at the operating point B exceeding the pressure Pa is a complete overload operation.

The present invention has been made in view of the above problems, and an object thereof is to provide a mold temperature control device capable of automatically performing overload protection of a pump.

[0012]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, the present invention provides a mold temperature provided with a heat medium feed pipe through which a pump is interposed, and a temperature controller for cooling or heating the heat medium flowing through the feed pipe. In the adjusting device, a pressure control valve for maintaining the discharge pressure at a value lower than the overload pressure is provided on the discharge side of the pump.

[0013]

[Action]

 According to the mold temperature controller of the present invention, even if the pressure loss of the mold to be temperature controlled is large and the discharge pressure of the pump exceeds the overload pressure due to the pressure loss, the pressure control valve The discharge pressure can be automatically lowered by the operation of and can be maintained at a value lower than the overload pressure. Further, since the discharge pressure of the pump is maintained at a value lower than the overload pressure, the flow rate of the heat medium sent to the mold can be maximized.

[0014]

【Example】

 1 to 3 show an embodiment of the present invention, which is a structural diagram of the mold temperature control device of FIG. 1, FIG. 2 is a sectional view of a pressure control valve, and FIG. 3 is a pump capacity and a mold pressure loss. It is a figure which shows the relationship of. In the present embodiment, the same reference numerals are used for the parts having the same configurations as those of the conventional example shown in FIG. 2, and the description thereof will be omitted.

The mold temperature control device shown in FIG. 1 includes a device main body 1, a feed pipe line 2, a cooler 3, a heater 4, an outflow header 5, an inflow header 6, and a pressure control valve. 7 and a bypass line 8. Each structure of the apparatus main body 1, the feeding pipe line 2, the cooler 3, the heater 4, the outflow header 5 and the inflow header 6 is the same as the conventional one shown in FIG.

As shown in FIG. 2, the pressure control valve 7 has a casing 7a, an inlet 7b, an outlet 7c, and a bypass port 7d which are communicated with each other, and a piston 7e capable of opening and closing the bypass port 7d. Prepared inside. The piston 7e is urged toward the bypass port 7d by a coil spring 7f to close the bypass port 7d, and the strength of the coil spring 7f can be adjusted by a pressure adjusting screw 7g. The pressure control valve 7 is provided on the discharge side of the pump 2c, the feed conduit 2 is connected to the inlet 7b and the outlet 7c, and one end of the bypass conduit 8 is connected to the bypass port 7d. ing.

In the pressure control valve 7, the heat medium sent into the inlet 7b can be sent out from the outlet 7c through the periphery of the piston 7e. When the pressure of the heat medium sent to the inlet 7b exceeds a predetermined value specified by the strength of the coil spring 7f, the piston 7e is pushed to open the bypass port 7d, and part of the bypass port 7d is opened from the bypass port 7d. It can be returned to the vicinity of the inlet of the feeding pipeline 2 through the ipas pipeline 8.

The bypass line 8 is connected to a position slightly downstream of the bypass port 7 d of the pressure control valve 7 and the inlet 2 a of the feed line 2. Although the bypass line 8 is shown to be long in the illustrated example, it is actually used with a short length.

The mold temperature controller described above heats the outlet 5 a of the outflow header 5 and the inlet 6 a of the inflow header 6 in the temperature control passages 11 b formed in both mold plates 11 a of the mold 11. The opening / closing valves 5b and 6b of both the headers 5 and 6 are used by being connected through the temperature control line 12, and are appropriately opened and closed depending on the connection state of the temperature control line 12. The heating and cooling of the die 11 are performed by switching the switching valve 2d and operating the heating machine 4 or the cooling machine 3 and the pump 2c in the same manner as in the conventional case.

FIG. 3 shows the relationship between the pump capacity and the mold pressure loss. In the figure, T3 is the pressure loss curve of the mold 11, N2 is the capacity curve of the pump 2c, and Pa is the overload pressure of the pump 2c. is there. When the pump 2c is operated with a T3 mold having a large pressure loss, the intersection C between the pressure loss curve T3 and the broken line is the operating point of the pump 2c in the conventional case, and the operating point C exceeds the overload pressure Pa. As a result, the pump 2c is completely overloaded. However, in the above-mentioned device, even if the pressure loss of the mold to be temperature-controlled is large and the discharge pressure of the pump 2c exceeds the overload pressure Pa due to the pressure loss, the pressure control valve 7 can be operated. Therefore, the discharge pressure can be automatically lowered. Specifically, the piston 7e is pushed by the pressure of the heat medium sent from the pump 2c to the inlet 7b of the pressure control valve 7, the bypass port 7d is opened, and a part of it is sent out from the bypass port 7d to the bypass pipe line 8. As a result, the discharge pressure decreases, and the discharge pressure is maintained at a value lower than the overload pressure Pa. That is, the operating point of the pump 2c is C'which is lower than the overload pressure Pa.

As described above, according to the mold temperature controller described above, the pump 2c can be operated at a discharge pressure lower than the overload pressure Pa thereof even if the pressure loss of the mold to be temperature-controlled is large. Unlike the conventional case, the pump is not operated in an overloaded state, and the pump 2c and the temperature control device can be reliably prevented from being damaged or damaged. Further, since the discharge pressure of the pump 2c is maintained at a value lower than the overload pressure Pa, the flow rate of the heat medium sent to the mold can be secured to the maximum and the temperature can be controlled well.

FIG. 6 is a cross-sectional view of essential parts showing another embodiment of the pressure control valve. The pressure control valve 17 has an inlet 17b and a bypass port 17c which are in communication with each other in a casing 17a so as to face each other, and a piston 17d capable of opening and closing the inlet 17b is provided therein. The piston 17d is urged toward the inlet 17b by a coil spring 17e to close the inlet 17b. The pressure control valve 7 is interposed in the middle of the bypass pipe 18, and the bypass pipe 18 is connected to the inlet 17b and the bypass port 17c.

In the pressure control valve 17, when the pressure of the heat medium sent to the inlet 17b exceeds a predetermined value defined by the strength of the coil spring 17e, the piston 17d is pushed to open the inlet 17b, and a part of it is opened. Can be returned from the bypass port 7d to the vicinity of the inlet of the feeding pipeline 2 through the bypass pipeline 18. The obtained effect is similar to that of the above-mentioned embodiment.

The pressure control valve illustrated in the embodiment may be of another type as long as it has the same function.

[0025]

[Effect of the device]

 As described in detail above, according to the present invention, the pump can be operated at a discharge pressure lower than the overload pressure even when the pressure loss of the mold to be temperature-controlled is large. The pump and temperature control equipment can be reliably prevented from being damaged or damaged without being operated in this state. Further, since the discharge pressure of the pump is maintained at a value lower than the overload pressure, the flow rate of the heat medium sent to the mold can be secured as much as possible and good temperature control can be performed.

[Brief description of drawings]

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

FIG. 2 is a sectional view of a pressure control valve,

FIG. 3 is a diagram showing a relationship between pump capacity and die pressure loss.

FIG. 4 is a block diagram of a mold temperature control device showing a conventional example.

FIG. 5 is a diagram showing the relationship between pump capacity and die pressure loss.

FIG. 6 is a sectional view showing another embodiment of the pressure control valve.

[Explanation of symbols]

2 ... Feed line, 2c ... Pump, 3 ... Cooler, 4 ... Heater, 7, 17 ... Pressure control valve.

Claims (1)

[Scope of utility model registration request] 1. A heat medium feed conduit having a pump interposed therebetween,
In a mold temperature controller equipped with a temperature controller that cools or heats a heat medium flowing through a feeding pipe line, a pressure control valve for maintaining a discharge pressure at a value lower than an overload pressure on a discharge side of a pump. The mold temperature control device is characterized in that.