JP6711997B1 - Manufacturing method of mold temperature sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a temperature sensor for a mold, which can reduce the cost as compared with a conventional one, and can reduce the size of a formed temperature sensor. A method for manufacturing a mold temperature sensor according to the present invention includes a step of preparing a sheath thermocouple 2 including thermocouple wires 7 and 8 and an insulating material 9 inside a metal sheath 6, and a sheath thermoelectric element. A step of preparing a fixed body 3 having a through hole 13 into which the pair 2 is inserted and having an outer peripheral surface matching the inner peripheral surface of the holding hole 105 of the mold 100; and inserting the sheath type thermocouple 2 into the through hole 13. After that, the step of fixing the sheath type thermocouple 2 to the fixed body 3 is performed. [Selection diagram] Figure 1

Description

The present invention relates to a method for manufacturing a temperature sensor for a mold, which is used by being attached to a mold.

Conventionally, temperature sensors have been used in various manufacturing fields. The temperature measured by the temperature sensor is used for monitoring whether or not a defect has occurred during manufacturing and for performing various controls during manufacturing.

For example, in an injection molding die in which a cavity into which molten resin is injected is formed, and the molten resin is cooled and hardened in the cavity to have a predetermined shape, a thermocouple consisting of a pair of wires is used. A temperature sensor for a mold is used, which is configured by, and is attached to the mold to measure the temperature. With such a mold temperature sensor, it is possible to measure the temperature of the mold and the temperature of the resin in the mold.

In Patent Document 1 as a mold temperature sensor, two elongated holes are formed at the tip of a support cylinder, and each wire constituting a thermocouple is inserted into each of the holes, and each of the holes is formed at the tip of the support cylinder. Welded wires are shown.

Further, in Patent Document 2, one insertion hole is formed in a fixed cylindrical body and an inclined surface is formed at a tip end portion of the insertion hole, a pair of strands are inserted into the insertion hole, and each strand is welded on the sloped surface. A die temperature sensor is shown.

Japanese Patent No. 4177333 Japanese Patent No. 5503717

By the way, in the temperature sensor for a mold of Patent Document 1, two holes must be provided at the tip of the support cylinder, and each wire must be inserted into each hole. Causing an increase. Further, the cost increases as the number of steps increases. Furthermore, since a tube is used as an insulating material for each wire, it is necessary to reduce the diameter of the tube in order to downsize the temperature sensor. In addition, in this temperature sensor, the compensating lead wire connected to each element wire is also inserted into the support tube. However, the compensating lead wire has a large diameter, which is an obstacle to the miniaturization of the temperature sensor.

Further, in the mold temperature sensor of Patent Document 2, although only one insertion hole is required to be formed in the fixed cylindrical body, this insertion hole has different inner diameters on the proximal end side and the distal end side of the fixed cylindrical body. It will take time to descend. In addition, since the inclined surface must be formed at the tip of the insertion hole, the cost is increased. Furthermore, since the wires that make up the thermocouple are divided into two wires, it is necessary to insert them in the insertion hole in an aligned state, which makes assembly difficult and increases the time required for assembly. Become.

In view of such conventional problems, in the method for manufacturing a mold temperature sensor of the present invention, it is possible to reduce the cost as compared with the conventional method, and to reduce the size of the formed temperature sensor. Is an issue.

The present invention is a method for manufacturing a temperature sensor for a mold, which is attached to a holding hole provided in a mold, wherein a step of preparing a sheath type thermocouple including a thermocouple wire and an insulating material inside a metal sheath, It has a through hole into which the sheath type thermocouple is inserted and a reinforcing member holding hole which is connected in series to the through hole and has an inner peripheral surface larger in diameter than the through hole, and which is adapted to the inner peripheral surface of the holding hole. And a tubular reinforcing member having an outer diameter that can be inserted into the reinforcing member holding hole and an inner diameter that allows the sheath-type thermocouple to be inserted. And a step of inserting the sheath type thermocouple into which the reinforcing member has been inserted into the through hole , and then fixing the sheath type thermocouple to the fixed body , and the reinforcing member into the reinforcing member holding hole. And fixing the reinforcing member to the fixed body .

The present invention is also a method of manufacturing a mold temperature sensor attached to a holding hole provided in a mold, comprising a thermocouple wire and an insulating material inside a metal sheath, the thermocouple wire being provided at one end. A step of preparing a sheath material in which the sheath material is exposed, and a through hole into which the sheath material is inserted, and a reinforcing member holding hole connected to the through hole in series and having an inner peripheral surface larger in diameter than the through hole A step of preparing a fixed body having an outer peripheral surface conforming to the inner peripheral surface of the holding hole; and an inner diameter capable of being inserted into the reinforcing member holding hole and capable of inserting the sheath material. And a step of preparing a tubular reinforcing member, and after inserting the sheath material through which the reinforcing member is inserted into the through hole, weld the one end to the fixed body using a welding material , and A step of inserting a reinforcing member into the reinforcing member holding hole and fixing the reinforcing member to the fixed body .

Here, it is preferable to further include a step of polishing so that the front end surface of the welding material and the front end surface of the fixed body after welding are flush with each other.

According to the method for manufacturing a mold temperature sensor of the present invention, a sheath type thermocouple formed of a sheath material having a thermocouple element wire and an insulating material inside a metal sheath is used, or the sheath material itself is prepared. As it is made to function as a thermocouple when assembling with the fixed body, it becomes unnecessary to use a tube that becomes an insulating material of each element wire or a compensating lead wire connected to each element wire as in the past. It is possible to reduce the size of the temperature sensor. Further, only one through hole is provided in the fixed body, and it is not necessary to provide an inclined surface at the tip of the through hole unlike the conventional temperature sensor. In addition, in the conventional temperature sensor, it was necessary to pass the two wires in the insertion hole while aligning them, but since the thermocouple wire of the present invention is surrounded by the metal sheath and can be handled integrally, it is assembled. The time required for can be reduced. Therefore, the processing man-hours and the assembly man-hours can be suppressed, and the cost can be reduced.

It is a figure showing one embodiment of a temperature sensor for molds according to the present invention. The member which comprises the temperature sensor for metal molds shown in FIG. 1 is shown, (a) is a top view and sectional drawing of a sheath type thermocouple, (b) is a top view and sectional drawing of a fixed body. It is sectional drawing which showed typically the state which attached the temperature sensor for metal molds of FIG. 1 to the metal mold|die.

An embodiment of a method for manufacturing a temperature sensor for a mold according to the present invention will be described below with reference to the accompanying drawings.

First, the mold temperature sensor 1 formed by the manufacturing method of the present embodiment will be described. As shown in FIG. 1, the mold temperature sensor 1 includes a sheath thermocouple 2, a fixed body 3, a reinforcing member 4, and a connector 5.

As shown in FIG. 2( a ), the sheath type thermocouple 2 has a cylindrical metal sheath 6 in which two thermocouple wires 7 and 8 and an insulating material 9 constituting a thermocouple are arranged. The sheath material 10 provided is used as a thermocouple.

The sheath material 10 accommodates two types of metal wire base materials, which are the thermocouple wires 7 and 8, inside a metal pipe that is the base material of the metal sheath 6, and further between the metal pipe and the metal wire base material. It is formed by filling the insulating material 9 and then stretching the metal wire base material together with the metal pipe. The metal sheath 6 and the two thermocouple wires 7 and 8 are separated from each other, and an insulating material 9 is interposed between them to be insulated from each other. As the metal sheath 6, for example, stainless steel is generally used, but other metals such as copper and titanium may be used. Further, various materials can be used for the thermocouple wires 7 and 8 depending on the operating temperature range and characteristics. For example, one is used as a combination of alumel and the other is used as a combination of chromel. As the insulating material 9, aluminum oxide or silicon oxide is used in addition to magnesium oxide.

Then, the thermocouple wires 7 and 8 are electrically connected at one end of the sheath material 10 to function as the sheath thermocouple 2. As shown in FIG. 2A, in the present embodiment, a sheath material 10 in which the end surfaces of the thermocouple wires 7 and 8 are exposed at one end is prepared, and one end of the sheath material 10 is covered with a welding material. Are welded, and thereby the thermocouple wires 7 and 8 are electrically connected to function as the sheath type thermocouple 2. In the present embodiment, the sheath thermocouple 2 is formed by performing welding so that a surplus is formed as shown by an imaginary line and then polishing so that the welded portion becomes flat. .. When the sheath material 10 is made to function as the sheath type thermocouple 2, for example, the insulating material 9 at one end of the metal sheath 6 is removed to expose the tips of the thermocouple wires 7 and 8 a little longer, and then these After joining the tip portions to each other by welding or the like, the metal sheath 6 is filled with the insulating material 9 again to bring the joined portion into an insulating state, and if necessary, one end portion of the metal sheath 6 is sealed by welding or the like. Other methods may be adopted. The sheath type thermocouple 2 is formed with the optimum specifications for measuring the temperature of the molten resin injected into the mold as described later.

The fixed body 3 is formed in a stepped cylindrical shape as a whole as shown in FIG. 2(b), and is located on the tip side of the fixed body 3 when it is finished as the mold temperature sensor 1. 11 and a fixed body base end portion 12 which is connected to the fixed body front end portion 11 in series and whose outer peripheral surface has a larger diameter than the fixed body front end portion 11. Further, inside the fixed body tip portion 11 and the fixed body base end portion 12, a through hole 13 extending from the fixed body tip portion 11 to an intermediate portion of the fixed body base portion 12 and a through hole 13 are connected in series. At the same time, a reinforcing member holding hole 14 whose inner peripheral surface has a diameter larger than that of the through hole 13 is provided. The fixed body tip portion 11 is a portion to be inserted into a holding hole provided in the mold as described later, and the outer peripheral surface of the fixed body tip portion 11 is fit into the inner peripheral surface of the holding hole without a gap. It is finished with high dimensional accuracy.

The reinforcing member 4 has a cylindrical shape in the present embodiment, and is made of metal such as stainless steel. The reinforcing member 4 is formed to have an outer diameter that can be inserted into the reinforcing member holding hole 14 and an inner diameter that allows the sheath thermocouple 2 to be inserted.

The connector 5 is attached to the other end of the sheath thermocouple 2 and is used for connecting the sheath thermocouple 2 to a thermocouple thermometer (not shown). By connecting the connector 5 to the thermocouple thermometer, the temperature can be measured based on the electromotive force generated in the sheath thermocouple 2.

Next, a method of manufacturing the mold temperature sensor 1 according to this embodiment will be described. First, the sheath thermocouple 2 and the fixed body 3 described above are prepared.

Then, the sheath thermocouple 2 is inserted into the through hole 13 of the fixed body 3. In this embodiment, the reinforcing member 4 is inserted from the tip side of the sheath thermocouple 2 in advance, and then the sheath thermocouple 2 is inserted into the through hole 13. Since the sheath type thermocouple 2 uses the metal sheath 6 and is relatively elastic, it can be smoothly inserted into the through hole 13. Further, since the thermocouple wires 7 and 8 used in the sheath-type thermocouple 2 are surrounded by the metal sheath 6, they can be handled integrally, and the wires are arranged in the aligned state. It is easier to assemble than the conventional temperature sensor that had to be passed through. The tip of the sheath type thermocouple 2 inserted into the through hole 13 is located inside the tip of the fixed body tip 11.

After that, as shown in FIG. 1, the welding material 15 is used to weld the tip of the sheath thermocouple 2 and the tip 11 of the fixed body to fix the sheath thermocouple 2 to the fixed body 3. In the present embodiment, as shown by the phantom line in the figure, welding is performed so that the welding material 15 rises from the fixed body tip portion 11, and the sheath thermocouple 2 is reliably welded inside the through hole 13. So that

After that, polishing is performed so that the welding material 15 which becomes an excess is mainly removed, and finishing is performed so that the tip surface of the welding material 15 and the tip surface of the fixed body tip portion 11 after polishing are flush with each other. The tip surface of the welding material 15 and the tip surface of the fixed body tip portion 11 which have become flush with each other after polishing function as the measurement surface of the mold temperature sensor 1. Further, the welded material 15 and the tip end surface of the fixed body tip portion 11 after polishing are finished with high dimensional accuracy so that the length from the end surface 12a of the fixed body base end portion 12 falls within a predetermined dimension.

Then, after inserting the reinforcing member 4 into the reinforcing member holding hole 14, welding is performed at the opening of the reinforcing member holding hole 14 to fix the reinforcing member 4 to the fixed body 3. Since the sheath thermocouple 2 uses the metal sheath 6 and can withstand high temperatures, the reinforcing member 4 and the fixed body 3 are welded together after the measurement surface of the mold temperature sensor 1 is formed as described above. However, it does not affect the measurement surface.

The mold temperature sensor 1 manufactured in this manner can be attached to a mold 100 as shown in FIG. 3 for use. The illustrated mold 100 includes a cavity mold 101 and a core mold 102, and a cavity (cavity) 103 is provided at a joint between the cavity mold 101 and the core mold 102. Further, the cavity mold 101 is provided with a gate 104 for injecting the molten resin into the cavity 103, and the core mold 102 is a holding hole into which the fixed body tip portion 11 of the mold temperature sensor 1 is inserted. 105 is provided. As described above, the outer peripheral surface of the fixed body tip portion 11 is finished with high dimensional accuracy so as to fit into the inner peripheral surface of the holding hole 105 without a gap. As described above, the welded material 15 and the tip end surface of the fixed body tip portion 11 after polishing are finished with high dimensional accuracy so that the length from the end surface 12a of the fixed body base end portion 12 falls within a predetermined dimension. ing. Here, when the fixed body tip portion 11 is inserted into the holding hole 105, the fixed body base end portion 12 is made to contact the end surface 106 of the holding hole 105, and is fixed from the tip surface of the fixed body tip portion 11 described above. The predetermined dimension up to the end surface 12a of the body proximal end portion 12 is the same as the depth of the holding hole 105 starting from the end surface 106 (the depth from the end surface 106 to the cavity 103). Therefore, by inserting the fixed body tip portion 11 into the holding hole 105 to the end, the tip surface of the fixed body tip portion 11 can be aligned with the inner surface of the cavity 103 (same surface).

In forming a resin product with the mold 100, molten resin is injected from the gate 104 to fill the cavity 103 with the molten resin. Here, if the injection amount of the molten resin is larger than the appropriate amount, the internal pressure of the cavity 103 becomes excessively high, the molten resin leaks from the joint between the cavity mold 101 and the core mold 102, and burrs are formed on the resin product. Sometimes. If the injection amount is smaller than the proper amount, the cavity 103 is not filled with the molten resin, which causes a short circuit problem. By the way, the mold temperature sensor 1 described above can measure the temperature of the resin injected into the cavity 103. Therefore, when the cavity 103 is filled with the molten resin and the temperature of the molten resin is measured on the measurement surface of the mold temperature sensor 1, the temperature can be measured by the mold temperature sensor 1 at that time. Since it is possible to detect that a certain amount is filled, it is possible to optimize the injection amount of the molten resin.

Further, as described above, the fixed body tip portion 11 of the mold temperature sensor 1 is fitted into the holding hole 105 without any gap, and the tip surface of the fixed body tip portion 11 is aligned with the inner surface of the cavity 103. Since they are on the same surface, the resin does not flow out from the holding hole 105 to form a burr, and the resin product to be formed has the marks of the holding hole 105 and the mold temperature sensor 1 conspicuously left. There is no.

Further, since the fixed body tip portion 11 has a small diameter and the area of the tip surface is small, the force received from the molten resin filled in the cavity 103 becomes small and the load applied to the mold temperature sensor 1 can be reduced. it can. Further, since the holding hole 105 provided in the mold 100 is also small, the strength of the mold 100 is not significantly impaired. Further, in such a temperature sensor, in general, responsiveness and measurement accuracy are improved by downsizing, so that the mold temperature sensor 1 also has an advantage in this respect.

In addition, when removing the conventional temperature sensor from the mold, a special tool is generally required, but since the mold temperature sensor 1 includes the reinforcing member 4 fixed to the fixed body 3, it is reinforced. The member 4 can be grasped and pulled out from the mold 100.

In the above-described embodiment, the sheath thermocouple 2 is formed from the sheath material 10 and is attached to the fixed body 3. However, even if the sheath material 10 is attached to the fixed body 3 as it is, a mold is used. The temperature sensor 1 for use can be manufactured.

In the manufacturing method of attaching the sheath material 10 to the fixed body 3 as it is, the sheath material 10 in which the end faces of the thermocouple wires 7 and 8 are exposed at one end is prepared. The fixed body 3 is prepared as described above. Furthermore, as in the above-described embodiment, the reinforcing member 4 is inserted from one end of the sheath material 10.

Then, the sheath material 10 in which the end faces of the thermocouple wires 7 and 8 are exposed is inserted into the through hole 13 of the fixed body 3. The distal end portion of the sheath material 10 inserted into the through hole 13 is located inside the distal end portion of the fixed body distal end portion 11.

After that, the welding material 15 is used as in the above-described embodiment to weld the distal end portion of the sheath material 10 and the fixed body distal end portion 11 to fix the sheath material 10 to the fixed body 3. At this time, since the thermocouple wires 7 and 8 are electrically connected by the welding material 15, the sheath material 10 can function as a thermocouple. When welding is performed with the welding material 15, the welding is performed so that the welding material 15 rises from the fixed body tip portion 11 as in the above-described embodiment, and then the tip surface of the welding material 15 and the fixed body tip portion 11 are separated. It is preferable to polish the tip surfaces so that they are flush with each other.

As described above, in the manufacturing method of attaching the sheath material 10 to the fixed body 3, the step of forming the sheath type thermocouple 2 from the sheath material 10 in advance is unnecessary, so that the number of assembling steps is reduced and the time required for assembling is also reduced. Therefore, the cost can be further reduced.

The method for manufacturing the mold temperature sensor according to the present invention has been described above with reference to specific embodiments, but the present invention is not limited to the above-described embodiments, and various modifications are made within the scope of the claims. It also includes those with. For example, the reinforcing member holding hole 14 into which the reinforcing member 4 is inserted may be eliminated, and welding may be performed directly on the base end side of the fixed body 3. Further, the shape of the reinforcing member 4 is not limited to the cylindrical shape, and may have, for example, a C-shaped cross section. The means for fixing the reinforcing member 4 to the fixed body is not limited to welding, and other means such as caulking may be adopted. The reinforcing member 4 does not necessarily have to be provided.

1: Temperature sensor for mold 2: Sheath type thermocouple 3: Fixed body 4: Reinforcing member 5: Connector 6: Metal sheath 7: Thermocouple wire 8: Thermocouple wire 9: Insulating material 10: Sheath material 11: Fixed body tip part 12: Fixed body base end part 12a: End face of fixed body base end part 13: Through hole 14: Reinforcing member holding hole 15: Welding material 100: Mold 101: Cavity mold 102: Core mold 103: Cavity 104 : Gate 105: Holding hole 106: End face

Claims (3)

A method for manufacturing a mold temperature sensor attached to a holding hole provided in a mold, comprising:
A step of preparing a sheath type thermocouple including a thermocouple wire and an insulating material inside the metal sheath;
It has a through hole into which the sheath type thermocouple is inserted and a reinforcing member holding hole which is connected in series to the through hole and has an inner peripheral surface larger in diameter than the through hole, and which is adapted to the inner peripheral surface of the holding hole. A step of preparing a fixed body having an outer peripheral surface to
A step of preparing a tubular reinforcing member having an outer diameter that can be inserted into the reinforcing member holding hole and an inner diameter that allows the sheath type thermocouple to be inserted;
After inserting the sheath type thermocouple into which the reinforcing member is inserted into the through hole, the sheath type thermocouple is fixed to the fixed body , and the reinforcing member is inserted into the reinforcing member holding hole and the reinforcement is performed. And a step of fixing a member to the fixed body . A method for manufacturing a mold temperature sensor attached to a holding hole provided in a mold, comprising:
A step of preparing a sheath material having a thermocouple wire and an insulating material inside the metal sheath and exposing the thermocouple wire at one end;
A through hole into which the sheath material is inserted, and a reinforcing member holding hole which is connected to the through hole in series and has an inner peripheral surface having a larger diameter than the through hole, and which has an outer circumference adapted to the inner peripheral surface of the holding hole. Preparing a fixed body having a surface,
Preparing a tubular reinforcing member having an outer diameter that can be inserted into the reinforcing member holding hole and an inner diameter that allows the sheath material to be inserted;
After inserting the sheath material through which the reinforcing member is inserted into the through hole, weld the one end to the fixed body using a welding material , and insert the reinforcing member into the reinforcing member holding hole. And a step of fixing a reinforcing member to the fixed body . The method for manufacturing a mold temperature sensor according to claim 2, further comprising a step of polishing so that a front end surface of the welding material after welding and a front end surface of the fixed body are flush with each other.

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