JP3042421B2 - Temperature detecting device, method of using the same, and fixing device using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a temperature detecting device, a method of using the same, and a fixing device using the same, and more particularly to detecting a temperature by contacting a curved object such as a heating roll of the fixing device. The present invention relates to a temperature detecting device of the type, a method of using the same, and an improvement of a fixing device using the same.

[0002]

2. Description of the Related Art Generally, an image forming apparatus such as a copying machine adopting an electrophotographic system is usually provided with a heating type fixing device for fixing a toner image transferred onto a recording sheet (recording material). Conventionally, this type of fixing device includes a heating roll and a pressure roll that rotate while being pressed against each other,
The recording paper on which the unfixed toner image is formed is inserted between these rolls to fix the unfixed toner image.

[0003] In such a fixing device, a method of controlling the temperature of a heating source of a heating roll, for example, so as to keep the fixing conditions uniform so as to keep the fixing temperature constant, is employed. In adopting the technique, a temperature detecting device for detecting the surface temperature of the heating roll is required. In a conventional temperature detecting device, as shown in FIG. 25, for example, a sensor unit 110 that is in contact with a heating roll 101, which is an object to be measured, is attached to a sensor attaching portion of a sensor holder (not shown).
As 10, a hollow elastic body 112 is held by a holding member 111, a thermosensitive element 113 such as a thermistor is disposed on the side of the heating roll 101 of the hollow elastic body 112, and the thermosensitive element 114 is formed by a protective sheet 114 made of polyimide or the like. 11
3 is used (for example, Japanese Patent Publication No. Sho 58-33492). In addition, reference numeral 102 denotes a pressure roll that presses against the heating roll 101, and 103 denotes a heating roll 10.
1 is a heating lamp built in the apparatus.

Further, as another example of a sensor unit 110 of the conventional temperature detecting device, as shown in FIG. 26, a thermosensitive element 113 such as a CA thermocouple or a thermistor is provided on the back side of a thin film sheet 121. , The thin film sheet 121
Surface layer 12 having a low coefficient of friction, such as fluororesin,
2 is provided to smooth the contact with the object to be measured such as the heating roll 101, while a sponge elastic sheet 124 is stretched over a U-shaped channel-like support member 123, and the thin film sheet 121 is placed on the heating roll 101 side. There is one that is elastically pressed against the surface (for example, Japanese Utility Model Publication No. 57-1961).
No. 2).

In such a temperature detecting device, by providing the hollow elastic body 112 and the sheet-like sponge elastic body 124, the surface temperature of the heating roll 101 can be accurately detected, and the change in environmental temperature There is an advantage that it is hardly affected by

[0006]

However, in the conventional temperature detecting device, for example, in the former type, since the hollow elastic body 112 has a space inside, the dimension in the thickness direction is correspondingly reduced. It gets bigger. At this time,
When the heating roll 101 rotates, the heating roll 1
In order to prevent the hollow elastic body 112 from being easily deformed by being pulled down along the rotation direction of the hollow elastic member 01, it is necessary to restrain and hold the side surface of the hollow elastic body 112 with the rigid holding member 111. become. Therefore, the hollow elastic body 1
Since the size of the temperature sensing device 12 itself becomes large and a holding member for holding the size itself is indispensable, it is difficult to reduce the size of the entire temperature detecting device.

When the temperature is detected by the heat-sensitive element 113, the support member (the hollow elastic body 112,
Since the entire holding member 111) loses heat, the detected temperature of the thermosensitive element 113 is not stabilized until the entire temperature detecting device reaches a uniform temperature. However, if the heat capacity of the entire supporting member is large, the detected temperature will be reduced accordingly. Since the time required for the entire temperature detecting device to reach a uniform temperature increases, there is a technical problem that the temperature sensing performance of the thermosensitive element 113 cannot follow a rapid temperature change.

On the other hand, in the latter type of the conventional temperature detecting device, it may be possible to reduce the size of the device itself as compared with the former type.
(A certain amount of thickness is necessary because of the elasticity in the thickness direction), and since the heat capacity of the support member 123 is large,
As in the former type, there is a technical problem that the temperature sensing performance of the thermosensitive element 113 cannot follow a rapid temperature change.

As a means for solving such a technical problem, for example, as shown in FIG. 27, a pair of legs of a U-shaped channel-like support member 131 is constituted as an elastically deformable elastic leg 132, The heat-resistant film 133 on which the heat-sensitive element 113 such as a thermistor is sandwiched is supported by the support member 131.
28, the heat-resistant film 133 is elastically brought into contact with an object to be measured such as the heating roll 101, or as shown in FIG. On the other hand, the leaf spring 142 is cantilevered by a screw, and a heat-resistant film 133 in which a thermosensitive element 113 such as a thermistor is sandwiched between the fixed plate 141 and a free end of the leaf spring 142 is wound. 13
3 is elastically brought into contact with an object to be measured, such as a heating roll 101 (see, for example,
0-181768).

According to this type, the heat-resistant film 13
Reference numeral 3 denotes a heating roll 101 by the elastic action of the elastic leg 132 of the support member 131 or the elastic action of the leaf spring 142.
To the heating roll 1 by the heat-sensitive element 113.
01 can be faithfully detected, and the only member supporting the heat-sensitive element 113 is the heat-resistant film 133. Since the heat-resistant film 133 is thin and has a very small heat capacity, The amount of heat transmitted to the heat-resistant film 133 is very small, and the temperature detection performance of the heat-sensitive element 113 can quickly follow a rapid temperature change.

However, in such a type, when an object to be measured such as the heating roll 101 rotates and an airflow is formed around the object, a situation in which the airflow easily passes through the space 134 occurs. Due to the influence of the airflow, there is a technical problem that the heat of the thermosensitive element 113 is easily taken away, and the temperature detection performance of the thermosensitive element 113 is easily changed by the surrounding environment. In particular, in the case of the above-described type, as shown in FIG.
3 passes through the space 134 between the heat-resistant film 133 and the supporting member 131 as shown by the arrow X. On the other hand, in the type shown in FIG. 28, a part of the heat released to the back side of the thermal element 113 is reflected by the
Although much of the released heat is returned to the side of the heat-resistant film 133 and the space 134 between the support members 141 and 142.
The heat is dissipated inside as shown by the arrow X. For this reason, in the types shown in FIGS. 27 and 28, the responsiveness of the thermal element 113 is inevitably reduced with respect to the heat loss due to the heat radiation.

Incidentally, such a problem is not limited to the temperature detecting device of the fixing device, but occurs, for example, with respect to the entire temperature detecting device for detecting the temperature of a curved object to be measured.

SUMMARY OF THE INVENTION The present invention has been made to solve the above technical problems, and is small in size without damaging an object to be measured and has good temperature followability to a rapid temperature change. It is another object of the present invention to provide a temperature detecting device, a method of using the temperature detecting device, and a fixing device using the same, which can effectively suppress fluctuations due to the surrounding environment.

[0014]

That is, the present invention provides:
As shown in FIG. 1, in a temperature detecting device for detecting a temperature by contacting a curved object 1 to be measured, a support member 2 having an arcuate surface 2a is stretched over both ends of the arcuate surface 2a in the arcuate direction. And a heat-sensitive element 5 provided on a surface of the thin film 4 facing the arcuate surface 2a.

When the temperature detecting device is used, the thin film 4 including the area of the thermosensitive element 5
What is necessary is just to make it contact only a part, and to arrange | position the to-be-measured object 1 and the support member 2 in non-contact.

In such a technical means, in the temperature detecting device according to the present invention, the object to be measured 1 can be any object having a curved surface requiring temperature detection. For example, in the case of a fixing device used in an electrophotographic image forming apparatus, a heating roll having a built-in heating source is usually used, but a pressure roll which presses against the heating roll may be used. Examples of devices other than the fixing device include a shaft of a heater for sending hot air, a connecting shaft between an engine and a generator, and a curved roll or shaft requiring temperature detection.

The support member 2 has an arcuate surface 2a.
May be rigid or elastically deformable, and may be appropriately selected. Here, the arcuate surface 2a is the heat-sensitive element 5
As long as the surface facing the surface has a so-called arcuate shape, a wide variety of shapes (for example, trapezoidal cross-section, etc.) including those with a mountain-shaped cross section, a smoothly curved surface shape, and the like are included. For example, the support member 2 may be formed by bending the plate-like support member 2, but the outer shape of the support member 2 does not necessarily need to be formed in an arc shape. Further, as for the shape of the arcuate surface 2a, the shape of the arcuate surface 2a reflects heat released into the space 3 between the arcuate surface 2a and the thin film 4 irrespective of a symmetrical shape or an asymmetrical shape. It is preferable to appropriately select the heat from the viewpoint of efficiently concentrating heat on the heat-sensitive element 5 of the thin film 4, and in particular, a smooth curved arcuate surface 2 a is preferable. Further, the shape of the arcuate surface 2a may be in at least one direction, but may be in any two or more directions (ultimately, the arcuate surface 2a is formed in any arbitrary direction). So-called bowl-shaped surfaces) are also included. At this time, the arcuate surface 2
Forming a is preferable in that the heat efficiency can be improved because the reflected heat in each direction can be efficiently concentrated on the heat-sensitive element 5 of the thin film 4.

Further, the material of the thin film 4 may be appropriately selected as a material, but it is necessary that the thin film 4 has heat resistance at least in a measurement temperature range of the DUT 1.
Here, from the viewpoint of surely setting the thermosensitive element 5 at an appropriate position with respect to the measured object 1, it is preferable to use an elastic thin film having elasticity in a plane direction as the thin film 4,
In this case, the mounting error of the support member 2 is absorbed by the elastic action of the elastic thin film, and the elastic thin film portion corresponding to the thermosensitive element 5 is always arranged in close contact with the measured object 1. However, instead of the elastic thin film, the arcuate surface 2a of the support member 2
The components may have an elastic action. Then, as the elastic thin film, it is sufficient that the elastic thin film is usually made of an elastic material having heat resistance. However, even if the elastic thin film has no heat resistance, a heat-resistant coating layer may be provided on the surface thereof. . In addition, heat transfer to the thermal element 5 (the thermal element 5
The sensitivity of the thin film 4 is preferably 50 μm or less, the thickness is preferably 25 μm or more in consideration of the strength limit, and the thickness is preferably about 25 to 50 μm in consideration of both.

Further, regarding the arrangement position of the thermal element 5,
What is necessary is just to provide in the location where the reflected heat from the bow-shaped surface 2a efficiently concentrates according to the shape of the said bow-shaped surface 2a.
Here, if the distance of the space 3 between the heat-sensitive element 5 and the arcuate surface 2a of the support member 2 is less than 1 mm, the heat insulation effect of the air layer in the space 3 tends to be insufficient, while If it exceeds 5 mm, the space 3 is too wide and the amount of airflow in the surroundings increases, and the heat of the thermosensitive element 5 is easily taken away by the airflow, so that about 1 to 5 mm is preferable.
However, the space 3 may be formed as a substantially closed space so that airflow does not enter.

The thermosensitive element 5 includes the object 1 to be measured.
As long as the temperature can be detected, a thermocouple, a thermistor, or the like may be appropriately selected. In this case, in order to keep the sensitivity of the thermal element 5 good, it is preferable to make the side surface of the device 1 of the thermal element 5 flat. Further, the thermosensitive element 5 may be attached to the thin film 4 by using an adhesive or a tape, or may be attached to the thin film 4 itself.
May be integrally formed.

From the viewpoint of minimizing the heat radiation from the thermal element 5, it is preferable to cover the space 3 side of the thermal element 5 with a heat conductive sheet such as an aluminum foil.

From the viewpoint of extending the life of the temperature detecting device without sacrificing the responsiveness of the thermal element 5, the thermal element 5 is made of a heat conductive sheet made of, for example, aluminum, phosphor bronze or copper. It is preferable to provide the thin film 4 via a (protective plate).

From the viewpoint of improving the response of the thermosensitive element 5, the heat capacity of the thermosensitive element 5 and the thin film 4 needs to be as small as possible. If there is a metal member (a heat conductive sheet made of aluminum foil, aluminum, phosphor bronze or copper) in contact with the thermosensitive element 5 and the thin film 4 and the thermosensitive element 5 at the contact portion, the total heat capacity including this is 0.04 J /
It is preferable that it is not more than ΔC.

Further, the present invention is also directed to a fixing device having a curved object 1 for temperature detection, in which the temperature detecting device according to the present invention is incorporated. In this case, the temperature detecting device to be incorporated includes all of the various aspects described above.

According to the above-described technical means, when the sensor unit (support member 2, thin film 4, and thermal element 5) is set on the object 1, the thermal element 5 is attached to the object 1.
Only the portion of the thin film 4 including the region is brought into contact with the object 1 to be measured.
And the supporting member 2 may be arranged in a non-contact manner. At this time, the close contact state between the portion of the thermosensitive element 5 and the DUT 1 is kept good, and the heat of the DUT 1 is quickly transmitted to the thermosensitive element 5. In addition, the dimension in the thickness direction of the sensor unit substantially corresponds to the three regions of the space, and by setting the three regions of the space to be narrow to some extent, a conventional type (a type using a hollow elastic body and a holding member) is used. Smaller than required. In addition, since the heat capacity of the thin film 4 in contact with the thermosensitive element 5 is small, the heat of the thermosensitive element 5 is hardly transmitted to the support member 2 through the thin film 4, and the heat taken from the thermosensitive element 5 is accordingly reduced. It is not unnecessarily communicated to the side.

In particular, in the present invention, the support member 2 has an arcuate surface 2a, and the arcuate surface 2a
Since the heat-sensitive element 5 is provided at a position facing to a.
The heat from the back of the thermosensitive element 5 and the heat that has passed through the thin film 4 from the DUT 1 are released into the space 3, and most of the released heat is, as shown by the arrow Z in FIG. After being reflected at 2a, the light is intensively returned to the thermosensitive element 5 again. Therefore, the heat released into the space 3 does not dissipate unnecessarily as it is, and is efficiently used as heat for detecting the temperature of the thermosensitive element 5.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail based on an embodiment shown in the accompanying drawings. First Embodiment FIG. 2 shows a first embodiment of a temperature detecting device of a fixing device to which the present invention is applied. In FIG. 1, the fixing device includes a heating roll 11 that rotates while being pressed against each other, and a pressure roll 12 coated with an elastic body, and a recording paper 13 on which an unfixed toner image is formed is inserted between the rolls 11 and 12. Thus, the unfixed toner image is fixed. Reference numeral 14 denotes a heating lamp (heater) built in the heating roll 11.

FIG. 3 shows details of the temperature detecting device 20 used in the present embodiment. The temperature detecting device 20 according to this embodiment is configured such that a base end of a sensor holder 21 made of a rigid plate is attached to a predetermined fixing portion 15 via a fixture 22, and a sensor unit 23 is provided on the sensor holder 21. It is. In the sensor unit 23 according to this embodiment, an arcuate surface 211 having an isosceles triangular cross section (a mountain shape) is formed in the sensor holder 21, and spaces 24 are secured inside both ends of the arcuate surface 211. The elastic thin film 25 elastically deformable is stretched along the surface direction as shown in FIG.
As shown in (b), the thermosensitive element 26 crushed and flattened, for example, by crushing a CA thermocouple, is applied to a portion of the back surface of the elastic thin film 25 opposite to the vertex (linearly symmetric position) of the arcuate surface 211 by using a heat-resistant adhesive. It is intended to be attached. FIG.
In (a) and (b), reference numeral 261 denotes a lead wire of the thermal element 26.

In the present embodiment, the elastic thin film 2
5 covers the front surface and the back surface (excluding the space portion 24) of the sensor holder 21;
For example, an insertion slit 222 into which the base end of the sensor holder 21 is inserted is formed along, for example, a horizontal direction, and a screw insertion hole 223 is vertically opened through the insertion slit 222 so that the base end of the sensor holder 21 is inserted into the insertion slot. The mounting screw 224 is inserted through the screw insertion hole 223 of the mounting fixture body 221 and the screw insertion hole of the sensor holder 21 so as to be fixed to the predetermined fixing portion 15.

Further, in the present embodiment, as the sensor holder 21, a phosphor bronze plate, a SUS304 CSP plate,
SK5M heat-treated plate, bainite steel plate, other metals in general (including sintered, cast, extruded products), resin plate, ceramic plate and the like can be used. In the present embodiment, for example, a phosphor bronze plate is used. Was.

Examples of the elastic thin film 25 include a polyimide sheet, a Teflon sheet, a Teflon sheet containing glass cloth, a phosphor bronze plate, a SUS304CSP plate, and an SK.
A 5M heat-treated plate having a thickness of 25 μm to 50 μm can be used. In the present embodiment, for example, a polyimide sheet having a thickness of 25 μm to 50 μm is used.

Further, in the present embodiment, the elastic thin film 2
As shown in FIG. 4B, the width d2 of the element 5 is set to be several times larger than the width d1 of the thermosensitive element 26.
Has a heat capacity of 0.04 J / ° C or less.

Such a temperature detecting device is shown in FIG.
As shown in FIG.
Is attached so that the periphery of a certain portion of the thermosensitive element 26 is elastically contacted with the heating roll 11 which is the measured object. At this time, in the present embodiment, the distance s between the heat-sensitive element 26 of the space 24 and the bent portion of the bow-shaped surface 211 is 1 to
It is set to about 5 mm. Further, the elastic thin film 25
Follows the surface shape of the heating roll 11 and elastically expands and deforms. Since the elastic stress is sufficiently small over the entire elastic thin film 25, the reaction force accompanying the elastic deformation of the elastic thin film 25 is The sensor unit 23 does not act so strongly on the heating roll 11 side, and is mounted in a state of being in light contact with the surface of the heating roll 11.

Here, when the performance of the temperature detecting device according to the present embodiment was examined, no flaw was observed on the surface of the heating roll 11 and the temperature followability of the heat sensitive element 26 was good, and furthermore, It was confirmed that the temperature variability due to the environment could be reduced. This is because, as indicated by the arrow Z in FIG. 6, the heat released from the back surface of the thermosensitive element 26 and the heat that has passed through the elastic thin film 25 from the heating roll 11 are reflected by the arcuate surface 211 in the space 24. It is presumed that this is caused by returning intensively to the thermosensitive element 26 again and suppressing the loss of heat given to the thermosensitive element 26 to a small value.

In this embodiment, the heat-sensitive element 2
The method of attaching 6 is not limited to the above-described attachment using the heat-resistant adhesive, and the heat-sensitive element 26 may be attached with a heat-resistant adhesive tape 27, for example, as shown in FIG. Alternatively, as shown in FIG. 7B, when the elastic thin film 25 is formed,
1 may be integrally formed, and the heat-sensitive element 26 may be inserted and held in the housing portion.

Further, in the present embodiment, the heat-sensitive element 2
6 is not limited to the flat type in which the above-described CA thermocouple is crushed. For example, a normal thermocouple may be used as it is.
As shown in (a), a bead-type (including SB-type) thermistor 26a or a thin-film thermistor may be used. In this case, for example, in order to satisfy a demand for using the bead-type thermistor 26a with a little more sensitivity, for example, as shown in FIG. 8B, a bead-type thermistor 26b having a flat surface on the side of the measured object is used. What should I do? As an example of the manufacturing method at this time, for example, when coating glass on a bead type thermistor,
The glass to be coated may be pressed while being melted, and then cooled.

Further, the shape of the sensor holder 21 can be appropriately changed in accordance with the positional relationship between the mounting position and the object to be measured. For example, as shown in FIG. An arcuate surface 211 having an isosceles triangular cross section may be provided on the side, and the elastic thin film 25 may be stretched so that the space 24 is secured in the arcuate surface 211. Incidentally, also in this modification, the elastic thin film 25 is attached to the sensor holder 2.
1 covers the front surface and the back surface (excluding the space portion 24), but in the present modification, a joining piece portion 252 of the elastic thin film 25 is provided on the front side and the back side of the sensor holder 21, and the joining piece portion 252 is attached. The elastic thin film 25 is attached to the sensor holder 21 by joining.

Embodiment 2 FIG. 10 shows Embodiment 2 of the temperature detecting device. Note that components similar to those of the first embodiment are denoted by the same reference numerals as those of the first embodiment, and detailed description thereof is omitted here.
In the figure, the basic configuration of the temperature detecting device is substantially the same as that of the first embodiment, but differs from the first embodiment in that the space portion 24 side of the thermosensitive element 26 is covered with an aluminum foil 41, 26 and an aluminum foil 41 are fixed with a heat-resistant adhesive tape 27.

Therefore, according to the present embodiment, basically the same operation as that of the first embodiment is obtained, but the temperature followability of the heat-sensitive element 26 becomes better than that of the first embodiment. confirmed. This is presumed to be due to the effect that the aluminum foil 41 returns the heat released from the thermosensitive element 26 to the thermosensitive element 26 as radiant heat, and the heat loss from the thermosensitive element 26 is further reduced.

Third Embodiment FIG. 11 shows a third embodiment of the temperature detecting device and is an explanatory diagram similar to the main part of FIG. Note that components similar to those of the first embodiment are denoted by the same reference numerals as those of the first embodiment, and detailed description thereof is omitted here. In the figure, the basic configuration of the temperature detecting device is substantially the same as that of the first embodiment, but is different from the first embodiment. A conductive protection plate 51 is provided, and the heat-sensitive element 26 and the protection plate 51 are fixed with a heat-resistant adhesive tape 27.

Therefore, according to the present embodiment, basically the same operation as that of the first embodiment is obtained, but it has been confirmed that the life of the temperature detecting device is longer than that of the first embodiment. This is because the protection plate 51 prevents the local pressure from being applied to the heat-sensitive element 26, and the life of the heat-sensitive element 26 is extended.

Fourth Embodiment FIG. 12 shows a fourth embodiment of the temperature detecting device, and is an explanatory view similar to the main part of FIG. Note that components similar to those of the second and third embodiments are denoted by the same reference numerals as those of the second and third embodiments, and detailed description thereof is omitted here. In the figure, the basic configuration of the temperature detecting device is a combination of the second and third embodiments,
Is covered with an aluminum foil 41, while a protective plate 5 made of aluminum, phosphor bronze or copper is provided on the measurement object side of the thermal element 26.
1 is provided, and the heat-sensitive element 26, the aluminum foil 41 and the protection plate 51 are fixed by the heat-resistant adhesive tape 27.

Therefore, according to the present embodiment, it has been confirmed that the temperature sensitivity of the thermosensitive element 26 is better and the life of the temperature detecting device is longer than in the first embodiment.

It should be noted that the second to fourth embodiments also include various modifications as in the first embodiment.

Fifth Embodiment FIG. 13 is an explanatory view showing a fifth embodiment of the temperature detecting device. Note that components similar to those of the first embodiment are denoted by the same reference numerals as those of the first embodiment, and detailed description thereof is omitted here. In the figure, the basic configuration of the temperature detecting device is substantially the same as that of the first embodiment, but, unlike the first embodiment, the sensor holder 21 is formed separately in two units, and the first holder unit 21a Is fixed to a predetermined fixing portion 15 via a fixture 22a, while the second holder unit 21b is, for example, an arcuate surface 2 having a mountain-shaped cross section.
11, the base end of which is connected and fixed to the distal end of the first holder unit 21a via a fixture 22b.
Reference numeral 28 in the drawing denotes a positioning boss for preventing rotation, which fits into a positioning recess formed in a predetermined fixing portion. According to this type, since the sensor holder 21 is formed separately in the two holder units 21a and 21b, the first holder unit 21a is securely fixed in a state of being prevented from rotating to the predetermined fixing portion, and Is attached to the first holder unit 21a so that the position of the holder unit 21b can be adjusted. Therefore, the mounting position of the sensor holder 21 can be easily adjusted.

It should be noted that the present embodiment is different from the second to second embodiments.
Of course, the structure of No. 4 may be applied.

Sixth Embodiment FIG. 14 shows a sixth embodiment of the temperature detecting device. Note that components similar to those of the fifth embodiment are denoted by the same reference numerals as those of the fifth embodiment, and detailed description thereof will be omitted.
In the figure, the basic configuration of the temperature detecting device is substantially the same as that of the fifth embodiment, but unlike the fifth embodiment, the sensor holder 21 is not a mountain-shaped cross section, but a trapezoidal cross-sectional surface. 213. It was confirmed that this type also exerts substantially the same operation as the arcuate surface 211 having a mountain-shaped cross section.

Embodiment 7 FIG. 15 is a seventh embodiment of the temperature detecting device. In the figure, the basic configuration of the temperature detecting device is substantially the same as that of the first embodiment, but the configuration and mounting method of the sensor holder 21 of the sensor unit 23 are different from the first embodiment. That is, in the present embodiment, the sensor holder 21 has a smooth curved surface (for example, a semi-elliptical surface) arcuate surface 215 on the distal end side.
On the other hand, a mounting part 216 is formed on the base end side, and the arcuate surface 215 and the mounting part 216 are connected by an inclined connection part 217. Then, the sensor holder 21
The fixing portion 216 is fixed to the predetermined fixing portion 15 with the fixing tool 22 via the holding plate 71, and a part from the arcuate surface 215 to the inclined connecting portion 217 is cut and raised so that a piece 218 is cut and raised. Cut-and-raised piece 218 and inclined connecting part 2
The sensor board 72 is sandwiched and fixed between the sensor board 17 and the sensor board 17, and further pressed down by a part of the holding plate 71 so as to prevent the sensor board 72 from coming off.

In this embodiment, the arcuate surface 21
An elastic thin film 25 that can be elastically deformed is stretched along the surface direction so as to secure a space portion 24 inside the thin film 5, and at the vertex (line-symmetric position) of the arcuate surface 215 on the back surface of the elastic thin film 25. A thermosensitive element 26 is provided at the opposing portion.
And such a temperature detecting device is provided with a sensor unit 2
The third elastic thin film 25 is attached so as to elastically contact a portion around the heat-sensitive element 26 with the heating roll 11 which is a measured object. At this time, in the present embodiment, the distance s between the heat-sensitive element 26 of the space 24 and the bent portion of the arcuate surface 215 is set to about 1 to 5 mm.

In this embodiment, the first embodiment
It has substantially the same effect as (a bow-shaped surface 211 type having a mountain-shaped cross section), but it has been confirmed that the temperature-sensing element 26 has a slightly better temperature following property than the first embodiment.
In the present embodiment, it goes without saying that the structures of the second to fourth embodiments may be applied.

Eighth Embodiment FIG. 16 shows an eighth embodiment of the temperature detecting device. In the figure, the basic configuration of the temperature detecting device is the same as that of the modification of the first embodiment (type of FIG. 9), but different from the type of FIG. The arcuate surface 219 is provided, and the space 2 is provided in the arcuate surface 219.
The elastic thin film 25 is stretched so as to secure 4, and the thermosensitive element 26 is fixed to a portion of the elastic thin film 25 where the heat reflected from the arcuate surface 219 is efficiently returned. Note that the same components as those in FIG. 9 are denoted by the same reference numerals as in FIG. 9 and detailed description thereof is omitted here. It was confirmed that this type also exerts substantially the same operation as the ninth embodiment.

Embodiment 9 FIG. 17 shows a bearing wear tester as another example of a device to which the temperature detecting device according to the present invention is applied. In the figure, a bearing wear tester includes shafts 63 on both support bearings 61 and 62.
(Built-in heater 64) is rotatably supported, while a test bearing 66 is mounted on a housing 65, the shaft 63 is engaged with the test bearing 66, and the shaft 63 is heated to a predetermined temperature. The wear degree of the test bearing 66 is inspected by rotating the shaft 63 by the driving force from the motor 67. In such a device, for example, in order to control the temperature of the shaft 63, a temperature detecting device 20 (Embodiments 1 to 8) in which the present invention is applied to the shaft 63 is incorporated. Therefore, in the first to eighth embodiments, the present invention is applied to temperature detection of a fixing device, but in the present embodiment, the present invention is applied to temperature detection of a bearing wear tester. .

[0053]

【Example】

◎ Example 1 Now, a temperature detecting device according to Embodiment 7 (FIG. 15 type:
A temperature follow-up test and a surrounding environment change test were performed using a smooth curved surface arcuate surface type, s = 3 mm, an aluminum foil 41, and a heat capacity of the thermal element 26 and the elastic thin film 25 of 0.01 J / ° C). First, the test apparatus will be described. As shown in FIG.
In contrast, the temperature detection device 20 (A) according to the present embodiment type
Further, as a comparative example, a non-contact infrared thermometer (B) made by Keyence, a temperature detector (C) directly attached with a CA thermocouple, and a sponge-type temperature detector (D) shown in FIG. Are set, and the heating roll 11 is connected to the heater 14.
And heated. The emissivity of the non-contact infrared thermometer (B) was set by the temperature detector (C).

FIG. 19 is a plot of the temperature change of each of the temperature detecting devices A to D. According to the figure, the infrared thermometer B rises and falls fastest, and then enters the temperature stable region and shows the same temperature as the temperature detecting device C.
This is considered to represent the surface temperature of the heating roll most faithfully from the performance of the thermometer. Next, the temperature detection device A according to the present example started up quickly, entered the temperature stable region, and showed the highest temperature. This means that the infrared thermometer B has the highest performance closest to that of the infrared thermometer B. Note that the temperature in the stable region indicates that the correct temperature is indicated by the CA thermocouple directly attached to the heating roll. The temperature rise characteristics of the thermocouple directly attached type C were slower than those of the type A of this example, and the temperature rise characteristics of the type D with sponge were the slowest. As a result, it is understood that the temperature rising characteristics of the type A of the present embodiment are good, and it is confirmed that the temperature followability is good.

Further, when the temperature reached the temperature stable region, the wind was forcibly sent to the heating roll 11 by means of a fan.
The result as shown in FIG. 20 was obtained. In the same figure, the same result was obtained with the type A of this embodiment and the infrared thermometer type B. However, the thermocouple direct attachment type C showed a change as if swirled by the airflow. In addition, the type D with sponge does not show the change caused by the air flow unlike the thermocouple directly attached type C, but the followability of the temperature change is slower than the type A of this embodiment and the type B of the infrared thermometer. It is confirmed.

Example 2 Next, a temperature detecting device according to Embodiment 2 (FIG. 8 type:
The cross section has a chevron-shaped arcuate surface type, an aluminum foil 41 is used, and the heat capacity of the thermosensitive element 26 and the elastic thin film 25 is 0.01 J / ° C. Was changed, and a temperature follow-up test was performed. However, in the test, the present example type A and the comparative examples B to C under a situation where forced air was sent by a fan
(Infrared thermometer type B, thermocouple direct attachment type C).

Here, the distance s of the type A of this embodiment is 2 mm, 5 mm, 6 mm, and 0 mm (contact state).
When the heating roll 11 is heated by a heater, the rising temperature characteristics of A to C are shown in FIGS. FIG.
According to FIG. 22, it is confirmed that the rising characteristics of the type A of this embodiment are close to those of the infrared thermometer type B. According to FIG. 23, as compared with FIGS. 21 and 22, it is confirmed that the rising characteristics of the type A of this embodiment are far from those of the infrared thermometer type B. When the heating roll 11 was heated by a heater with the distance s of the type A of the present example set to less than 1 mm, the rising characteristics of the type A of the present example were separated from the infrared thermometer type B as in FIG. It was confirmed that. Further, according to FIG. 24, the rising characteristics of the type A of the present embodiment are similar to those of the thermocouple directly attached type C.
Was confirmed to be inferior. Therefore, according to the experimental results, it is understood that the size of the space has an effect on maintaining the temperature tracking performance of the temperature detecting device in a good state, and in the type A of the present embodiment, the temperature tracking property is improved. 1 to keep
It is confirmed that mm ≦ s ≦ 5 mm is preferable.
This tendency (the temperature followability range is good: 1 mm ≦ s ≦ 5 m
About m), it was the same also in Example 1 type.

Example 3 Next, the temperature detecting device according to Embodiment 1 (FIG. 3, type
No aluminum foil 41, thermal element 26 and elastic thin film 2
5, a temperature follow-up test and an ambient environment change test were performed in the same manner as in Example 1. At this time, substantially the same results as those in FIGS. 19 and 20 were obtained, although the temperature followability was slightly reduced as compared with the type 1 of the embodiment 1 (with the aluminum foil 41).

Example 4 Next, a temperature detector according to Embodiment 3 (FIG. 11 type, protective plate 51 made of phosphor bronze, thermal element 26 and heat capacity of elastic thin film 25 of 0.01 J / ° C.) was used. When a temperature follow-up test and a durability test were conducted, it was confirmed that the temperature follow-up property was almost the same as that of the example 3 type as compared with the example 3 type, and that the life of the device was greatly extended.

[0060]

As described above, according to the present invention, a thin film is provided between the support member and the arcuate surface via a space, and a heat-sensitive element is arranged on the space side of the thin film. The thin film is brought into contact with the object to be measured, and the good fit of the thermosensitive element to the object to be measured is maintained. Therefore, it is necessary to use a conventional hollow elastic body and a holding member for holding the hollow elastic body. As a result, the entire temperature detecting device can be reduced in size. Further, since the supporting member for supporting the heat-sensitive element is the thin film itself, a heat insulating effect by the space can be expected, and heat is hardly transferred in the plane direction through the thin film. As compared with the elastic body and the member holding the elastic body, the heat capacity of the member to which the heat from the thermosensitive element is transmitted can be made extremely small. Good followability can be maintained.

In particular, according to the present invention, the support member has a substantially line-symmetrical arcuate surface, and the thermosensitive element is provided at a position facing the arcuate surface on the space side of the thin film. Even if heat from the back surface or heat that has passed through the thin film from the object to be measured is emitted into the space, much of the emitted heat can be intensively returned to the thermosensitive element side again after being reflected by the arcuate surface. . For this reason, the heat for temperature detection to the thermosensitive element can be used efficiently, and even if there is a heat loss from the thermosensitive element due to the influence of the airflow when the measured object rotates, The loss can be effectively compensated for, and the heat loss from the thermal element can be minimized. Therefore, it is possible to effectively prevent a decrease in the temperature following property of the thermosensitive element due to a change in the surrounding environment.

Further, in the present invention, the thin film is an elastic thin film which can be elastically deformed along the surface direction, the deformed portion of the elastic thin film is absorbed in the space, and the resistance to the object to be measured when the elastic thin film is elastically deformed By suppressing the reaction force, the stable contact state between the measured object and the thermosensitive element can be obtained even with a low contact pressure against the measured object. Can be maintained satisfactorily, and damage to the surface of the measured object can be effectively prevented.

Further, in the present invention, by setting the size of the space portion optimally, it becomes possible to suppress the passage of the air flow in the space portion even when a change in the surrounding environment, for example, the air flow occurs. . For this reason, the heat loss of the heat-sensitive element due to the airflow can also be effectively suppressed, so that the temperature following property of the heat-sensitive element can be more effectively prevented from lowering due to a change in the surrounding environment. In particular, in the present invention, the distance between the thermosensitive element and the arcuate surface facing the thermosensitive element is 1 mm to 5 mm.
If the distance is set to mm, it is possible to easily and reliably prevent the temperature following capability of the thermosensitive element from being lowered due to a change in the surrounding environment.

Furthermore, in the present invention, if a smooth curved arcuate surface is used, by optimizing the shape of the arcuate surface, almost the entire area of the arcuate surface can be used as a heat reflecting surface to the thermosensitive element. It can be used effectively. For this reason, it is possible to sufficiently secure the amount of heat returned to the thermosensitive element, and it is possible to more effectively prevent the temperature following property of the thermosensitive element from lowering due to a change in the surrounding environment.

In the present invention, if the space side of the heat-sensitive element is covered with a heat-conductive sheet such as an aluminum foil, the heat radiation from the heat-sensitive element can be further reduced. The responsiveness of the thermal element can be kept better.

In the present invention, if the thermal element is provided on the thin film via a heat conductive sheet made of, for example, aluminum, phosphor bronze or copper, the temperature detection can be performed without sacrificing the response of the thermal element. The life of the device can be further extended.

Further, according to the present invention, it is possible to easily construct a fixing device having a curved object to be measured for temperature detection, in which the temperature detecting device according to the present invention is incorporated.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a configuration of a temperature detecting device according to the present invention.

FIG. 2 is an explanatory diagram illustrating a configuration of a fixing device according to the first embodiment.

FIG. 3 is an explanatory diagram illustrating details of a temperature detection device used in the fixing device according to the first embodiment;

FIG. 4A is an explanatory front view showing a positional relationship between an elastic thin film and a thermosensitive element, and FIG. 4B is a plan view thereof.

FIG. 5 is an explanatory diagram showing an attached state of the temperature detecting device according to the first embodiment.

FIG. 6 is an explanatory diagram showing the function of the arcuate surface of the temperature detecting device according to the first embodiment.

FIGS. 7A and 7B are explanatory views showing different modifications of the mounting structure of the thermosensitive element according to the first embodiment.

FIGS. 8A and 8B are explanatory diagrams showing different modifications of the heat-sensitive element according to Embodiment 1. FIGS.

FIG. 9A is a front explanatory view showing a modification of the temperature detecting device according to the first embodiment, and FIG. 9B is a partially broken plan view thereof.

FIG. 10 is an explanatory diagram illustrating a temperature detection device according to a second embodiment.

FIG. 11 is an explanatory diagram showing a main part of a temperature detecting device according to a third embodiment.

FIG. 12 is an explanatory diagram illustrating a main part of a temperature detection device according to a fourth embodiment.

FIG. 13 is an explanatory diagram showing a temperature detecting device according to a fifth embodiment.

FIG. 14 is an explanatory diagram illustrating a temperature detection device according to a sixth embodiment.

FIG. 15 is an explanatory diagram illustrating a temperature detection device according to a seventh embodiment.

FIG. 16 is an explanatory diagram showing a temperature detecting device according to an eighth embodiment.

FIG. 17 is an explanatory view schematically showing a bearing wear tester according to a ninth embodiment.

FIG. 18 is an explanatory diagram illustrating an example of a test apparatus according to the first embodiment.

FIG. 19 is a graph showing the results of a temperature follow-up test of Example 1 and Comparative Example.

FIG. 20 is a graph showing the results of an ambient environment change test of Example 1 and Comparative Example.

FIG. 21 is a graph showing the results of a temperature follow-up test of Example 2 (s = 2 mm) and Comparative Example.

FIG. 22 is a graph showing temperature follow-up test results of Example 2 (s = 5 mm) and Comparative Example.

FIG. 23 is a graph showing temperature follow-up test results of Example 2 (s = 6 mm) and Comparative Example.

FIG. 24 is a graph showing the results of a temperature follow-up test of Example 2 (s = 0 mm) and Comparative Example.

FIG. 25 is an explanatory diagram showing an example of a conventional temperature detecting device.

FIG. 26 is an explanatory view showing another example of the conventional temperature detecting device.

FIG. 27 is an explanatory view showing still another example of the conventional temperature detecting device.

FIG. 28 is an explanatory view showing still another example of the conventional temperature detecting device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Measurement object, 2 ... Support member, 2a ... Arch surface, 3 ... Space part, 4 ... Thin film, 5 ... Thermal element

Claims (13)

(57) [Claims] 1. A temperature detecting device for detecting a temperature by contacting a curved object to be measured (1), a support member (2) having an arcuate surface (2a), and an arcuate direction of the arcuate surface (2a). A temperature sensing device comprising: a thin film (4) stretched on both ends of the thin film (4); and a thermosensitive element (5) provided at a position of the thin film (4) facing the arcuate surface (2a). 2. A temperature detecting device for detecting a temperature by contacting a curved object to be measured (1), a support member (2) having an arcuate surface (2a), and an arcuate direction of the arcuate surface (2a). A thin film (4) stretched on both ends of the thin film (4); and a heat-sensitive element (5) provided at a position facing the arcuate surface (2a) of the thin film (4). A method for using a temperature detecting device, characterized in that only a thin film (4) portion including a region of a thermosensitive element (5) is brought into contact, and an object to be measured (1) and a support member (2) are arranged in non-contact. 3. The temperature detecting device according to claim 1, wherein
A temperature detecting device, wherein the thin film (4) is an elastic body. 4. The temperature detecting device according to claim 1, wherein
A temperature detecting device, wherein the arcuate surface (2a) of the support member (2) is heat-reflective. 5. The device according to claim 1, wherein the support member (2) is plate-shaped and the arcuate surface (2a) is formed by bending the plate-shaped support member (2). Characteristic temperature sensing device. 6. The temperature detecting device according to claim 1, wherein
A temperature detecting device, wherein the heat-sensitive element (5) is arranged substantially at the center of the thin film (4) facing the arcuate surface (2a) of the support member (2). 7. The temperature detecting device according to claim 1, wherein
A temperature detecting device, wherein the arcuate surface (2a) of the support member (2) is formed in a curved surface shape that changes smoothly. 8. The temperature detecting device according to claim 1, wherein
A temperature detecting device, wherein a bow-shaped surface (2a) side of a thermal element (5) is covered with a heat conductive sheet. 9. The temperature detecting device according to claim 1, wherein
A temperature detecting device, wherein a thermosensitive element (5) is provided on a thin film (4) via a heat conductive sheet. 10. The temperature detecting device according to claim 1, wherein the heat-sensitive element is provided on the thin film via an adhesive sheet. 11. The temperature detecting device according to claim 1, wherein a distance of the space (3) between the thermosensitive element (5) and the arcuate surface (2a) facing the thermosensitive element (5) is 1 to 5 m.
m. 12. The temperature detecting device according to claim 1, wherein the thin film is heat-resistant. 13. A fixing device having a temperature detecting device that comes into contact with a heating roll as an object to be measured (1), the temperature detecting device comprising: a support member (2) having an arcuate surface (2a); A thin film (4) stretched on both ends of the surface (2a) in the bow direction, and a thermosensitive element (5) provided at a position of the thin film (4) facing the bow surface (2a). A fixing device characterized by the above-mentioned.