JPH05164624A - Sheathed thermocouple device and cartridge heater device - Google Patents

Abstract

PURPOSE:To improve reactivity by attaching a heat transfer member to the tip part of a sheath so that the member can be freely attached and removed, and enhancing the heat transfer property of the sheath. CONSTITUTION:A thermocouple 1 is inserted into a hole 12 formed in a metal mold 11 through the tip part of a sheath 3. At this time, a heat transfer member 2, which is attached to the tip part of the sheath 3, is inserted into the hole 12 together with the sheath 3, and the outer surface of the member 2 comes in to close contact with the inner surface of the hole 12. The base end part of the sheath 3 is located at the outside of the hole 12. The leads, which are extending from the base end, are connected to the conductor wires of a measuring circuit. The heat of the metal mold 11 is transferred to a heat sensitive end 4a of a thermocouple element 4 through the inner surface of the hole 12, the sheath 3 and insulating powder 5. At this time, the member 2 is in tight contact with the inner surface of the hole 12. Therefore, the sufficient quantity of the heat of the metal mold 11 quickly transfers to the sheath 3 and reaches the heat sensitive end 4a. Thus, the reactivity of the thermocouple 1 is improved, and the temperature close to the true temperature of the metal mold 11 can be measured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheath type thermocouple device and a cartridge heater device.

[0002]

2. Description of the Related Art A sheath type thermocouple has a thermocouple element inserted into a sheath whose distal end is closed and whose proximal end is open, with its thermosensitive end positioned at the distal end of the sheath, and inside the sheath. It is configured by incorporating an insulator that supports the. This type of thermocouple is used, for example, by inserting it into a hole formed in a resin mold and measuring the temperature of the mold.

The cartridge heater is constructed by incorporating a heating element and an insulator for supporting the heating element inside a sheath whose distal end is closed and whose proximal end is open, and the lead of the heating element is drawn out from the proximal end opening of the sheath. It is a thing. This heater is used, for example, for heating the mold by inserting it into a hole formed in a mold for resin molding due to its characteristic features.

[0004]

[Problems to be Solved by the Invention] The sheath type thermocouple has the following problems.

In the sheath type thermocouple, the heat transmitted from the outside of the sheath to the inside of the sheath via the sheath is sensed by the thermosensitive end of the thermocouple element located at the distal end of the sheath to measure the temperature. Further, in order to improve the measurement accuracy, it is required that the heat transfer property at the distal end of the sheath is high. Therefore, when the sheath type thermocouple is used by inserting it into the hole of the mold as described above, it is preferable that the outer surface of the sheath is in close contact with the inner surface of the hole in order to enhance the heat transfer property of the distal end portion of the sheath. ..

A sheath type thermocouple is manufactured by rolling a sheath incorporating a thermocouple element and an insulator. However, the outer diameter of the sheath obtained by this rolling process is limited to some extent for economic reasons. For this reason, it is difficult to properly match the outer diameter of the sheath with various types of inner diameters of the holes of the mold with high accuracy. Therefore, a standard product having an outer diameter of the sheath smaller than the inner diameter of the hole is used. Therefore, when the sheath thermocouple is inserted into the hole of the mold, there is a gap between the outer surface of the sheath and the inner surface of the hole. Therefore, this gap hinders the direct transfer of heat of the mold to the distal end portion of the sheath, which causes a decrease in heat transferability at the distal end portion of the sheath. The cartridge heater has the following problems.

Since the cartridge heater radiates the heat generated by the heating element to the outside through the sheath for heating, it is required to have high heat transferability from the sheath to the outside. Therefore, when the cartridge heater is used by inserting it into the hole of the mold as described above, it is necessary to bring the outer surface of the sheath into close contact with the inner surface of the hole in order to enhance the heat transfer property of the sheath. However, in this case, when the heating element generates heat,
There is a drawback that the sheath expanded by being heated by this heat is firmly combined with the hole of the mold and cannot be removed from the hole.

Therefore, when the cartridge heater is heating the die, if the heating element is broken and the cartridge heater needs to be replaced, the cartridge heater should be immediately removed from the die hole. Cannot be replaced, making replacement difficult. Therefore, generally, the outer diameter of the sheath is set to be smaller than the inner diameter of the hole so that a gap is provided between the sheath and the hole to escape the thermal expansion of the sheath. In this case, the heat transferability in transferring heat from the sheath to the mold is low.

In order to improve the heat transfer of the sheath,
There is a heater in which the lead of the heating element is pulled out from both ends of the sheath to be folded in two to have elasticity, and the folded two is inserted into the hole and brought into contact with the inner surface of the hole. The cartridge heater becomes extremely expensive. The problems of the sheath thermocouple and the cartridge heater described above cause the same problems.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a sheath type thermocouple device and a cartridge heater device having improved heat transferability in a sheath at low cost.

[0011]

In order to achieve the above-mentioned object, a sheath type thermocouple device of the present invention comprises a thermocouple element having a heat-sensitive end at the inside of a sheath whose front end is closed and whose base end is open. A sheath-type thermocouple that is inserted at the tip of the sheath and that incorporates an insulator that supports the thermocouple element inside the sheath, and has a shape that surrounds the outside of the tip of the sheath And a heat transfer member that can be attached.

In order to achieve the above object, a cartridge heater device of the present invention is a cartridge heater in which a heating element and an insulator for supporting the heating element are incorporated inside a sheath whose front end is closed and whose base end is open, and the sheath. And a flexible heat transfer member provided so as to surround the outside thereof.

[0013]

When the sheath type thermocouple device is used by inserting it into the hole of the article, a heat transfer member having an outer diameter of a size close to the inner surface of the hole is attached to the tip of the sheath. Then, when the sheath is inserted into the hole of the article, the outer surface of the heat transfer member attached to the sheath comes into close contact with the inner peripheral surface of the hole. As a result, the heat of the article is sufficiently transferred to the distal end portion of the sheath via the heat transfer member. Therefore, the heat transfer property at the distal end portion of the sheath is enhanced.

When the sheath type thermocouple device is used for measuring the temperature of a fluid, a heat transfer member having fins or the like is attached to the tip of the sheath. This can enhance the heat transfer property at the distal end portion of the sheath.

When the cartridge heater device is inserted into the hole of an article for use, a flexible heat transfer member surrounding the sheath contacts the inner surface of the hole to transfer the heat of the heating element from the sheath. Fully transmitted to the article through the member. Therefore, the heat transfer property at the distal end portion of the sheath is enhanced. And, it is not necessary to use a sheath having an outer surface that closely contacts the inner surface of the hole of the article.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the sheath type thermocouple device according to the first invention of the present application will be described with reference to FIGS. 1 and 2 show one embodiment. This embodiment is an example in which a sheath type thermocouple is used to measure the temperature of a resin mold.

In the figure, 1 is a sheath type thermocouple (hereinafter abbreviated as thermocouple) and 2 is a heat transfer member. As shown in FIG. 2, the thermocouple 1 is a metal sheath 3 having a closed distal end and an open proximal end, a thermocouple element 4 inserted into the sheath 3, and a thermocouple filled in the sheath 3 to form a thermocouple. It is composed of heat-resistant insulating powder 5 that supports the element 4. Sheath 3
The base end opening of is closed with a moisture-proof seal (not shown). The thermocouple element 4 is formed by connecting a pair of wires at one end, and the connecting ends of these wires are the heat-sensitive ends 4a. The thermosensitive end 4a of the thermocouple element 4 is located at the tip of the sheath 3,
A lead (not shown) connected to the other end of each wire of the thermocouple element 4 is drawn out from the proximal end opening of the sheath 3. Then, the heat transfer member 2 is provided on the outer surface of the distal end portion of the sheath 3.
A threaded portion 6 for mounting the is formed. The outer diameter of the sheath 3 is smaller than the inner diameter of the hole 12 of the mold 11 described later.

As shown in FIG. 1, the heat transfer member 2 has a cylindrical shape with its tip closed, and the outer diameter of the heat transfer member 2 is such that the outer surface is in close contact with the inner surface of the hole 12 of the mold 11 described later. That is, the inner diameter of the heat transfer member 2 is large enough to insert the sheath 3, and the length of the heat transfer member 2 is large enough to cover the distal end portion of the sheath 3. On the inner surface of the heat transfer member 2, a screw portion 7 that is screwed into the screw portion 6 of the sheath 3 is formed. The heat transfer member 2 is made of a metal having a good heat transfer property, and is machined with a lathe or the like and finished with high dimensional accuracy. The heat transfer member 2 is fitted to the distal end portion of the sheath 3 of the thermocouple 1, and is detachably attached to the sheath 3 by screwing the screw portion 6 and the screw portion 7.

A case will be described in which the temperature of the mold used for resin molding is measured using the thermocouple device having the above-described structure. As shown in FIG. 1, the mold 11 is provided with a hole 12 for a thermocouple device. The inner diameter of the hole 12 is such that the outer surface of the heat transfer member 2 is in close contact with the inner surface of the hole 12. As shown in FIG. 1, the thermocouple 1 is inserted into the hole 12 from the tip of the sheath 3. The heat transfer member 2 attached to the distal end of the sheath 3 is inserted into the hole 12 together with the sheath 3, and the outer surface of the heat transfer member 2 comes into close contact with the inner surface of the hole 12.
The base end portion of the sheath 3 is located outside the hole 12, and the lead protruding from the base end of the sheath 3 is a lead wire (not shown) of a measurement circuit.
Connect to.

The heat of the mold 11 is transferred from the inner surface of the hole 12 to the heat transfer member 2, then from the heat transfer member 2 to the tip of the sheath 3 of the thermocouple 1, and further from the sheath 3 to the insulating powder 5. After that, it is transmitted to the heat-sensitive end 4a of the thermocouple element 4. in this case,
Since the heat transfer member 2 is in close contact with the inner surface of the hole 12 so as to surround the distal end of the sheath 3, the heat transfer member 2 and the hole 12 are different from the conventional case.
As compared with the case where there is a gap between the inner surface and the inner surface, the heat of the mold 11 is transferred to the sheath 3 in an extremely sufficient amount and quickly, and reaches the heat sensitive end 4a of the thermocouple element 4. Therefore, thermocouple 1
Is improved, and a temperature close to the true temperature of the mold 11 can be measured.

The heat transfer member 2 has a simple structure.
The structure for attaching the heat transfer member 2 to the sheath 3 is also simple,
Further, the heat transfer member 2 can be easily manufactured. Then, the thermocouple 1 can be manufactured in a conventional manner.

The inner diameter of the hole 12 formed in the mold 11 may vary depending on the specifications of the mold 11. Therefore, the hole 12
A plurality of types of heat transfer members 2 having different outer diameters are manufactured and prepared in advance according to the type of inner diameter, and the heat transfer member 2 having an outer diameter suitable for the inner diameter of the hole 12 to be used is selected to perform thermoelectric conversion. It is used by attaching it to the sheath 3 of the pair 1. With this configuration, one type of thermocouple 1 can handle a plurality of types of holes 12 having different inner diameters.

The thermocouple device can also be used for temperature measurement in applications other than mold temperature measurement. In this case, a heat transfer member suitable for measuring the temperature is prepared and attached to the distal end portion of the sheath 3.

FIG. 3 shows an embodiment in this case. This embodiment is applied when measuring the temperature of a fluid such as gas flowing through the pipe 13. The thermocouple 1 is arranged inside the pipe 13 through which gas flows and is attached to the pipe 13. A heat transfer member 8 is attached to the tip of the sheath 3 of the thermocouple 1. The heat transfer member 8 is made of a metal having a good heat transfer property, and is formed of a cylindrical portion 8a and a plurality of fin portions 8b formed on the outer peripheral portion of the cylindrical portion 8a, and a screw is formed on the inner surface of the cylindrical portion 8a. The portion 8c is formed. The heat transfer member 8 is fitted to the distal end portion of the sheath 3, and is attached by screwing the screw portion 8c of the cylindrical portion 8a and the screw portion 6 of the sheath 3. Due to the presence of the fin portion 8b, the heat transfer member 8 makes contact with the gas flowing through the pipe 13 in a large area, and can transfer the heat of the gas to the sheath 3 sufficiently and quickly, and further to the thermocouple element 4. . An embodiment of the cartridge heater device according to the second invention of the present application will be described with reference to FIGS. 4 and 5. This embodiment is applied to an example in which a cartridge heater is used for heating a resin mold.

In the figure, 21 is a cartridge heater, and 22 is a wire mesh which is an example of a heat transfer member. The cartridge heater 21 includes a metallic sheath 23 having a closed distal end and an open proximal end, and the heating wire 2 inserted into the sheath 23.
4. The insulating powder 25 is filled in the sheath 23 and has heat resistance to support the heating wire 24. The outer diameter of the sheath 23 is smaller than the inner diameter of the hole 32 of the mold 31 into which the cartridge heater 21 is inserted. The proximal end opening of the sheath 23 is closed by a moisture-proof seal (not shown). Exothermic line 2
Leads 26 connected to both ends of No. 4 are drawn out to the outside through a moisture-proof seal at the base end opening of the sheath 23.

The wire mesh 22 has a rectangular shape, and a pair of opposing sides has a length equal to the length of the sheath 23 of the cartridge heater 21, and another pair of opposing sides surrounds the sheath 23. It has a length that can be wound. The number of the wire nets 22 wound around the sheath 23 is set according to the size of the inner diameter of the hole 32 of the mold 31 into which the cartridge heater 21 is inserted. The wire net 22 is formed by weaving a metal wire having excellent heat transfer properties, and has flexibility as a whole. Then, one of a pair of sides of the wire net 22 having a length equal to the length of the sheath 23 is abutted on the outer peripheral portion of the sheath 23 along the axial direction thereof and fixed by welding. The wire net 22 is loosely wound around the sheath 23. The other side of the wire net 22 having a length equal to the length of the sheath 23 is not fixed, for example.

A case will be described in which the temperature of a mold used for resin molding is measured by using the cartridge heater device having the above-described structure. As shown in FIG. 5, a hole 31 for a cartridge heater device is formed in the mold 31.

As shown in FIG. 5, the cartridge heater 21
The sheath 23 is inserted into the hole 32 of the mold 31 from the tip end, and the lead 26 protruding from the base end of the sheath 23 is connected to a lead wire of a power supply circuit (not shown). The wire mesh 22 wound around the sheath 23 is provided with a hole 32 together with the sheath 23.
Inserted inside. Due to its flexibility, the wire netting 22 is positioned so as to overlap the gap between the outer surface of the sheath 23 and the inner surface of the hole 12. That is, the innermost peripheral portion of the wire net 22 is the sheath 2
3, the outermost peripheral part of the wire mesh 22 contacts the inner surface of the hole 12, and the innermost peripheral part, the outermost peripheral part of the wire mesh 22 and the parts located between them overlap and contact each other. There is.

When the heating wire 24 of the cartridge heater 21 is energized to generate heat, the heat is transferred to the sheath 23 via the insulating powder 25. Next, the heat is transferred from the innermost peripheral portion of the wire net 22 to the outermost peripheral portion through the intermediate portion of the wire nets 22 overlapping each other, and further to the inner surface of the hole 32 which is transferred to the outermost peripheral portion. Therefore, the heat of the heating wire 24 of the cartridge heater 21 can be directly transferred to the mold 31 by the metal net 22 to sufficiently heat the mold 31.

Further, the sheath 2 of the cartridge heater 21
3 is the hole 3 of the mold 31 even if expanded by the heat of the heating wire 24.
It does not become difficult to pull out the two closely. Therefore, when the heating wire 24 is broken while the die 31 is being heated by the cartridge heater 21, the cartridge heater 21 can be extracted from the hole 32 and replaced with a new cartridge heater 21.

Further, the number of the wire nets 22 wound around the sheath 23 is set according to the inner diameter of the hole 32 of the die 31 into which the cartridge heater 21 is inserted. 21 can accommodate a plurality of types of holes 32 having different inner diameters.

The first invention and the second invention of the present application are not limited to the above-described embodiments, but can be implemented by being modified in various ways, and the respective embodiments can be used mutually. Is also possible.

[0033]

As described above, according to the first invention of the present application, a heat transfer member is detachably attached to the distal end portion of the sheath of the sheath type thermocouple to enhance the heat transferability of the sheath, thereby providing a response. It is possible to obtain a sheath-type thermocouple device which is improved in performance and is particularly suitable when the sheath-type thermocouple is inserted into a hole formed in an object and used.

According to the second aspect of the present invention, the cartridge heater is provided with a flexible heat transfer member such as a wire mesh surrounding the sheath of the cartridge heater to enhance the heat transfer property of the sheath. It is possible to reliably transfer heat from the heater to the object to be heated, and it is possible to obtain a cartridge heater device particularly suitable for use when the cartridge heater is inserted into a hole formed in the object.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of a usage state of a sheath type thermocouple device according to the first invention of the present application.

FIG. 2 is a cross-sectional view showing the same sheath type thermocouple.

FIG. 3 is a cross-sectional view showing another embodiment of the sheath type thermocouple device in use.

FIG. 4 is a perspective view showing an embodiment of a cartridge heater device according to the second invention of the present application.

FIG. 5 is a cross-sectional view showing a usage state of the cartridge heater device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Sheath type thermocouple, 2 ... Heat transfer member, 21 ... Cartridge heater, 22 ... Wire mesh.

Claims (2)

[Claims] 1. An insulation for supporting a thermocouple element inside the sheath, the thermocouple element being inserted with the thermosensitive end located at the tip of the sheath, inside the sheath with the distal end closed and the proximal end open. A sheath type thermocouple with a built-in object,
A sheath type thermocouple device comprising a heat transfer member which is detachably attached to the distal end portion of the sheath and has a shape surrounding the outer end portion of the sheath. 2. A cartridge heater in which a heating element and an insulator for supporting the heating element are incorporated in a sheath whose distal end is closed and whose proximal end is open, and a flexibility which is provided around the outer side of the sheath. A cartridge heater device comprising a heat transfer member having the same.