JPH0222660Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a temperature detection device that detects the surface temperature of a rotating body such as a fixing roller or a stationary body in a heat fixing device such as a copying machine.

A temperature detection device for detecting the surface temperature of a rotating body such as a fixing roller in which the surface of a cylindrical roll made of aluminum is coated with Teflon in a heat fixing device of an electronic copying machine uses a temperature sensor directly attached to the surface of the rotating body. The most effective method is to detect the temperature by contacting it with the temperature.
It is disclosed in the publication no.

This is a device in which a heat-sensitive element such as a thermistor is attached to a thin film layer, and this is further held by an elastic body such as a sponge.In this temperature detection device, the heat-sensitive element, which is the temperature sensor, is in close contact with the surface of the rotating body. Accurate temperature detection is possible.

However, in this temperature sensing device, the holder supporting the elastic body is fixed to a support member made of metal or the like in order to elastically press against the surface of the object to be measured, such as a rotating body or a stationary body. Further, this support member is generally supported by a support shaft engaged with a spring and fixed to the main body of the device or the like.

Therefore, the holder, which is composed of a support member, a spring, etc., has a large number of parts and a relatively complicated structure, making the installation work troublesome and causing an increase in costs.

This invention aims to rectify the shortcomings mentioned above.
The purpose of this is to attach a heat-sensitive element to a substrate via an elastic body and cover the heat-sensitive element with a thin film tape to form a unit, which can be elastically and detachably attached to a holder. It is easy to replace and install the unit, and since the lead wire of the thermal element and the leader wire are connected through the board and the leader wire is fixed to the board, wiring and assembly are easy, and the leader wire can be attached to the board. It is an object of the present invention to provide a temperature detecting device which does not have a disconnection from a connecting part and has a simple structure, which can reduce costs.

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows an elastic body 1 that supports a heat-sensitive element 2 such as a thermistor, and is made of an elastic material such as silicone rubber or sponge, and has a recess 1a formed approximately in the center of its surface in which the heat-sensitive element 2 is accommodated. , and two cut grooves 1b communicating from the recess 1a to the outer periphery are formed, into which the lead wires 2a of the heat-sensitive element 2 are inserted. 3 is a filler to be filled into the recess 1a of the elastic body 1 in which the heat-sensitive element 2 is housed, if necessary;
Thereby, the heat-sensitive element 2 is fixed so as to be substantially flush with the surface of the elastic body 1. The filler 3 is preferably a silicone adhesive of the same quality as the elastic body 1, but the material is not limited to this, and any material may be used as long as it is heat resistant, or it may have a relatively high viscosity. Grease is also fine. The point is that the thin film tape 5, which will be described later, is in close contact with the surface formed by the recess 1a of the elastic body 1, and together with this, the thermosensitive element 2 does not move and is heat resistant. It's fine as long as it's something. Furthermore, it is preferable that the filler 3 is buried to such an extent that a part of the heat-sensitive element 2 is exposed, but care must be taken so that it does not protrude significantly from the heat-sensitive surface of the heat-sensitive element 2 or the elastic body 1. . Furthermore, if the filler 3 is made of a material with better thermal conductivity than the elastic body 1, even if the heat-sensitive element 2 is completely buried in the filler 3, there will be no problem in thermal response. It will never come.

4 is a substrate made of synthetic resin such as Bakelite to which the back surface of the elastic body 1 is fixed with an adhesive, and has a hole 4a through which the lead wire 2a of the heat-sensitive element 2 fixed to the elastic body 1 is inserted; Terminal 4 such as a pattern for soldering and fixing the tip of the lead wire 2a
b is formed. Further, engagement protrusions 4c are formed on two opposite sides of the substrate 4, and a drawer having a constricted portion 4d is provided on the remaining side near the terminal 4b where the engagement protrusions 4c are not formed. A wire fixing protrusion 4e is formed.

Reference numeral 5 denotes a thin film tape that covers from the heat-sensitive surface of the elastic body 1 to the substrate 4, and is attached to the back surface of the substrate 4 with an adhesive. The thin film tape 5 is made of a material such as polyimide resin or fluorine resin, and its thickness is suitably about 25 to 200 μm in terms of wear resistance and thermal response. In addition to the above-mentioned materials, if a material containing at least one type of fine powder such as carbon, graphite, molybdenum disulfide, boron nitride, or alumina is added to polyimide resin or fluorine resin, wear resistance and thermal response can be improved. You can further improve your sexuality. Furthermore, a thin film tape made of polyimide resin coated with fluororesin may also be used.

6 is an external lead wire whose one end is soldered to the terminal 4b of the board 4, and 7 is a tube for fixing the external lead wire 6 to the board 4, which is inserted into the lead wire fixing protrusion 4e of the board 4. At the same time, it is prevented from slipping out by the constricted portion 4d.

To explain the procedure for assembling each of the above-mentioned members, first, the back surface of the elastic body 1 is fixed to the substrate 4 with an adhesive or the like, and the heat-sensitive element 2 such as a thermistor is housed in the recess 1a of the elastic body 1. Then, if necessary, the heat-sensitive element 2 is fixed with a filler 3. Then,
Covering the heat-sensitive side of the elastic body 1 with a thin film tape 5,
The end piece is attached to the back surface of the substrate 4 with an adhesive. Furthermore, the lead wire 2a of the heat-sensitive element 2 is inserted into the hole 4a of the substrate 4, and is soldered to the terminal 4b formed on the back surface of the substrate 4.
Solder one end at the same time. Next, tube 7
The external lead wire 6 is inserted therein, and the tube 7 is inserted through the lead wire fixing protrusion 4e of the board 4, and the tube 7 is contracted by applying heat, for example. As a result, the external leader line 6
Since it is fixed to the board 4, even if an external force is applied to the external lead wire 6, it will not be disconnected from the terminal 4b.

The unit assembled as described above is referred to as unit A, and this is holder B, which is fixed near the object to be measured.
The shape of this holder B will be explained below with reference to FIG. 4.

The holder B is made of an elastic metal plate 8 made of stainless steel, iron, or the like, and is made by punching out a part of a thin plate using a press and then bending it. The structure includes a bottom plate part 8a, a side plate part 8b and a front plate part 8c connected to the bottom plate part 8a, and a connecting part 8d extending from the front plate part 8c to the side opposite to the side plate part 8b. Furthermore, it is formed of an elastic support part 8e extending from the connecting part 8d in parallel with the side plate part 8b. Further, the bottom plate portion 8a is provided with a mounting hole 8f for attaching to the main body of the copying machine, and the side plate portion 8b and the elastic support portion 8e are provided with fitting holes 8g and 8h into which the engagement protrusions 4c of the board 4 are fitted. .

To attach the unit A described above to such a holder B, insert and engage one engagement protrusion 4c of the substrate 4 with the surface on which the elastic body 1 is attached facing upward into one fitting hole 8g of the holder B. Then, the other engaging protrusion 4c is inserted and fitted into the fitting hole 8h with the elastic support portion 8e expanded. And elastic support part 8e
When the user releases his or her hand further, the substrate 1 is supported by the elastic support portion 8e.

Note that the height of the front plate portion 8c of the holder B is
If the height is set to be at least half of the height of Therefore, the force applied to the lead wire 2a of the heat-sensitive element 2 can be reduced.

As described above, the present invention consists of an elastic body fixed to a substrate, a heat-sensitive element placed on the surface of the elastic body, and covered with a thin film tape, which can be elastically attached to and detached from a holder. By attaching the heat-sensitive element to the lead wire and fixing the lead wire to the board, unit replacement and installation work becomes easy.Moreover, the lead wire of the heat-sensitive element and the lead wire are connected via the board to which the elastic body is attached. , the wiring and assembly can be easily performed, the leader wire will not be disconnected from the connection part of the board, the direction of the leader wire can be freely selected, and the usage pattern can be varied in various ways. Since it is simple, it has the effect of reducing costs.

[Brief explanation of the drawing]

The figures show an embodiment of the temperature sensing device according to the present invention, in which Figures 1a and b are perspective views and central sectional views of the elastic body, Figure 2 is a perspective view of the unit, and Figure 3 is a back view of the same. , FIG. 4 is a perspective view of the holder, and FIG. 5 is a perspective view of the entire holder. A... Unit, B... Holder, 1... Elastic body, 2... Heat sensitive element, 4... Substrate, 5... Thin film tape, 6... External leader line, 7... Tube.

Claims (1)

[Claims for Utility Model Registration] An elastic body, a substrate holding the elastic body and having a connection part to which a first lead wire is connected, a substrate placed on a surface of the elastic body and having a connection part to which a first lead wire is connected. A unit consisting of a heat-sensitive element having a wire, a thin film tape that covers at least the heat-sensitive surface side of the elastic body so as to cover the heat-sensitive element, and a fitting that elastically engages with a fitting part provided on the substrate. a holder that includes a joint and detachably holds the board; and a second lead wire, one end of which is connected to the connection part of the board, and a portion of a predetermined length from the one end fixed to the board. A temperature sensing device characterized by: