JP5096547B2 - Piston temperature measuring device - Google Patents

Description

  The present invention relates to a piston temperature measuring device.

Conventionally, the temperature of the piston has been measured using a hardness method or a thermocouple method. However, the hardness method has problems that it takes a test time, a measurement error is large, and only a maximum history temperature can be estimated. In addition, the thermocouple method requires a lot of man-hours to manufacture the measuring device, the cylinders that can be measured are limited, it is difficult to measure for a long time, and the thermocouple breaks frequently during measurement, There was a problem such as.
Thus, attempts have been made to put the electromagnetic induction method to practical use in piston temperature measuring devices (for example, Patent Documents 1 and 2).
The measurement principle of the electromagnetic induction method will be described with reference to FIGS.
The transmission coil 2a and the reception coil 2b are spaced apart from each other in the coil axis direction, and when the piston 1 reaches bottom dead center, the resonance coil is positioned in the vicinity of the intermediate position between the transmission coil 2a and the reception coil 2b in the vertical direction. 3a is arranged, and the resistance temperature measuring element 5 is connected to the resonance coil 3a so as to form a series closed circuit. When a high-frequency current from a high-frequency transmitter / receiver is passed through the transmission coil 2a, an induction current is generated in the reception coil 2b and the resonance coil 3a. Also changes. Therefore, by measuring the peak value of the output voltage of the receiving coil 2b with a voltage measuring instrument such as an oscilloscope, the temperature of the resistance temperature measuring element 5 can be calculated.
Thus, an electromagnetic induction type piston temperature measuring method has already been established.

However, when actually measuring the temperature of the piston, the motion side module 3 on which the resonance coil 3a is mounted is installed on the mechanism side such as the piston 1 that moves at a high temperature and high speed. Therefore, the motion side module 3 needs to have enough strength to withstand the inertial force due to the motion of the piston 1 under a high temperature condition.
In addition, the fixed-side module 2 having the transmission coil 2a, the reception coil 2b, and the ferrite core 2c around which the transmission coil 2a and the reception coil 2b are wound is installed at a location that receives high temperature and vibration of the engine. Must be strong enough to withstand.
Further, the resonance coil 3a of the moving side module 3 reaches around the ferrite core 2c of the fixed side module 2 at and near the bottom dead center of the piston 1. By ensuring a sufficient and accurate clearance between the three, the measurement accuracy can be improved, and the reliability of the temperature sensor can be improved.
Therefore, the structure of the moving side module and the stationary side module of the piston temperature measuring device is important in order to perform piston temperature measurement.

JP 09-292287 A JP 09-292288 A

  An object of the present invention is to provide a piston temperature measuring device using an electromagnetic induction method, in which the strength of the fixed side module and the motion side module is ensured.

The present invention for achieving the above object is as follows.
(1) It has a stationary module and an exercise module,
The stationary module, pressing the ferrite core, a stay with a hole ferrite core hole and the ferrite core setscrew is inserted, the side surfaces of the ferrite core is screwed for locking screw hole of the stay A set screw, and an adhesive provided in a gap between the ferrite core and the stay ,
The said set screw is a piston temperature measuring device which has a piston temperature measuring sensor which has pressed the side surface of the said ferrite core from the both sides of this ferrite core .
(2) The fixed side module includes a transmission coil, a reception coil, an external wiring disposed outside the fixed side module, and a relay element provided between the transmission coil and the reception coil. A piston temperature measuring device having the piston temperature measuring sensor according to (1).
(3) The ferrite core of the fixed side module has the transmitting coil and the receiving coil attached thereto,
The stay of the fixed side module holds the ferrite core,
The piston temperature measuring device having the piston temperature measuring sensor according to (2), wherein the relay element of the stationary module is disposed on an upper surface of the stay.

In the piston temperature measuring device of the above (1), the fixed-side module includes a set screw that presses the side surface of the ferrite core and an adhesive provided in a gap between the ferrite core and the stay. Can be fixed. For this reason, it is difficult for the ferrite core to come out of the stay even if it is affected by engine vibration or the like.
In the piston temperature measuring device of the above (2), since the stationary module includes the relay element, it is possible to prevent the wiring from being disconnected as compared with the case where the relay element is not provided.
In the piston temperature measuring device of the above (3), since the relay element is arranged on the upper surface of the stay, the thickness of the relay element is made smaller than the thickness of the external wiring, so that the motion side module and the fixed side module are The coil wiring can be taken out with a wide vertical clearance.

It is sectional drawing which shows the piston temperature measuring device of this invention Example 1, and its vicinity. It is the top view and partial sectional view of a fixed side module of the piston temperature measuring device of Example 1 of the present invention. It is a side view of the stationary side module of the piston temperature measuring device of Example 1 of this invention. It is the sectional view on the AA line of FIG. It is a partial expanded sectional view which shows the ferrite core of the stationary side module of the piston temperature measuring device of Example 1 of this invention, and its vicinity. It is a partial expanded sectional view which shows the clamping part and its vicinity of the 2 division | segmentation structure stay of a stationary-side module of the piston temperature measuring device of Example 1 of this invention. It is a top view of the movement side module of the piston temperature measuring device applicable to this invention Example 1 and Example 2. FIG. It is the ABCDEF line sectional view of FIG. It is a side view of the movement side module of the piston temperature measuring device applicable to this invention Example 1 and Example 2. FIG. It is a bottom view of the movement side module of the piston temperature measuring device applicable to this invention Example 1 and Example 2. FIG. It is a side view when the positioning pin of the movement side module of the piston temperature measuring device applicable to this invention Example 1 and Example 2 is attached to the pin attachment hole. It is a top view of the coil bobbin of the movement side module of the piston temperature measuring device applicable to this invention Example 1 and Example 2. FIG. It is the side view and partial sectional view of a coil bobbin of a movement side module of a piston temperature measuring device applicable to the present invention Example 1 and Example 2. It is a bottom view of the movement side module of the piston temperature measuring device applicable to this invention Example 1 and Example 2. FIG. It is sectional drawing which shows the piston temperature measuring device of this invention Example 2, and its vicinity. It is a top view of the stationary side module of the piston temperature measuring device of Example 2 of this invention. It is a side view of the fixed side module of the piston temperature measuring device of Example 2 of this invention. It is sectional drawing of the stationary side module of the piston temperature measuring device of Example 2 of this invention. It is a partial expanded sectional view which shows the ferrite core of the stationary-side module, and its vicinity of the piston temperature measuring device of Example 2 of this invention. It is sectional drawing which shows the conventional piston temperature measuring device and its vicinity. It is a partial expanded sectional view of the conventional piston temperature measuring device.

FIGS. 1-14 has shown the piston temperature measuring device of Example 1 of this invention, and FIGS. 15-19 has shown the piston temperature measuring device of Example 2 of this invention. However, FIGS. 7 to 14 are also applicable to the second embodiment of the present invention.
Portions common to the first and second embodiments of the present invention are denoted by the same reference numerals throughout the first and second embodiments of the present invention.
First, portions common to the first and second embodiments of the present invention will be described with reference to FIGS. 1 to 4, 8, and 10 to 14.
As shown in FIG. 1, a piston temperature measuring device 10 according to an embodiment of the present invention is a device that measures the temperature of a piston 1 of an internal combustion engine using an electromagnetic induction method. The piston temperature measuring device 10 includes a piston temperature measuring sensor 10 a, a high frequency transmission / reception device 52, a recording device 53, a voltage measuring device 54, and an arithmetic device 55.
The piston temperature measurement sensor 10 a includes a fixed side module 20, a motion side module 30, a positioning mechanism 40 (see FIG. 11), an external wiring 50, and a resistance temperature measurement element 51.

  As shown in FIG. 3, the stationary module 20 includes one or more transmitting coils 21 and receiving coils 22 described later, and the exercise module 30 includes one or more of the following described as illustrated in FIG. 8. A plurality of resonance coils 31 are provided, and one set of the transmission coil 21, the reception coil 22, and the resonance coil 31 forms a sensor for one channel. In FIG. 1, only one set of the fixed side module 20 and the exercise side module 30 is shown, and a case where three sets of coil units are provided for one set of modules is shown. However, depending on the mounting conditions, the piston temperature measuring sensor 10a can be mounted with a plurality of module sets for one cylinder, or an arbitrary number of coil units can be mounted with one set of modules. .

The fixed side module 20 is fixed by a screw 20a to a place where the internal combustion engine such as an engine block does not move. The fixed-side module 20 moves when there is no place where the moving parts such as the crankshaft connected to the piston 1 moving in a cylinder, the counterweight of the crankshaft, the connecting rod, or the moving parts do not contact. In a place where parts are shaved and are not in contact with each other, they are attached to a cylinder block or the like of an internal combustion engine via a support member 20b when direct or direct is impossible.
As shown in FIG. 2 or 4, the stationary module 20 includes a transmission coil 21, a reception coil 22, a ferrite core 23, a stay 24, a relay element 25, a coil wiring 26, a protection member 27, A set screw 28.

The transmission coil 21 and the reception coil 22 are wound and supported (attached) to the ferrite core 23 as shown in FIG. The transmission coil 21 and the reception coil 22 are arranged at intervals in the vertical direction of the ferrite core 23. A high-frequency current from the high-frequency transmitter / receiver 52 (see FIG. 1) flows through the transmission coil 21. Thereby, a magnetic field is formed, and an induced current is generated in the corresponding receiving coil 22 under the electromagnetic induction action.
The ferrite core 23 extends in the vertical direction. The ferrite core 23 is held by the stay 24 at least at the lower end. The upper end portion of the ferrite core 23 is located above the upper surface of the stay 24.

The stay 24 is made of a material that does not affect the magnetic field generated by electromagnetic induction, such as resin. As shown in FIG. 2, the stay 24 is formed with a mounting screw portion 24a through which the screw 20a (see FIG. 1) is inserted. A metal collar 24b is fitted to the mounting screw portion 24a.
The relay element 25 is made of a flexible substrate or the like. The relay element 25 is fixed to the stay 24. As shown in FIG. 4, the relay element 25 is provided between the external wiring 50 disposed outside the fixed-side module 20 and the transmission coil 21 and the reception coil 22. The relay element 25 has a thin plate shape, and the thickness thereof is smaller than the thickness of the external wiring 50.
The coil wiring 26 is provided between the relay element 25 and the transmission coil 21 and the reception coil 22.

The protection member 27 protects the coil wiring 26. The protective member 27 is made of a shrink tube, a cover, an adhesive, or the like. The protection member 27 is provided on the outer periphery of the ferrite core 23 located above the upper surface of the stay 24. When the protective member 27 is made of a shrinkable tube or a cover, it is difficult to attach the protective member 27 near the base of the ferrite core 23. In this case, it is desirable to use an adhesive 27a. Also, when the coil wiring 26 is passed through the outer wall surface of the stay 24 such as the upper surface of the stay 24, it is desirable to protect the coil wiring 26 using an adhesive.
As shown in FIG. 2, the set screw 28 is screwed into a set screw hole 24 c formed in the stay 24. The set screw 28 is inserted into the set screw hole 24 c from the side surface of the stay 24 and presses the side surface of the ferrite core 23 from both sides of the ferrite core 23.

  As shown in FIG. 1, the motion side module 30 is fixed to the bottom surface of the piston 1 in the cylinder by screws 30a. However, the motion side module 30 may be fixed to the piston 1 by, for example, welding, adhesion, fitting, or the like. As illustrated in FIG. 8 or FIG. 13, the exercise side module 30 includes a resonance coil 31, a bobbin body 32, a coil bobbin 33, a terminal 34, and a bobbin cover 35.

  As shown in FIG. 13, the resonance coil 31 is wound and supported (attached) to a coil bobbin 33. The resonance coil 31 is arranged coaxially with the transmission coil 21, the reception coil 22, and the ferrite core 23 of the fixed side module 20. When the piston 1 reaches the bottom dead center, the resonance coil 31 is fitted to the ferrite core 23 from the outside, and is located below the transmission coil 21 and above the reception coil 22.

The bobbin body 32 is made of a material that does not affect the magnetic field generated by electromagnetic induction, such as resin. The bobbin body 32 is fixedly attached to the piston 1. When the bobbin body 32 is attached to the piston 1 by the screw 30a, the bobbin body 32 is formed with an attachment screw portion 32a through which the screw 30a is inserted, as shown in FIG. A metal collar 32b is fitted to the mounting screw portion 32a.
The bobbin body 32 has a coil bobbin hole 32c opened upward. The coil bobbin 33 is disposed in the coil bobbin hole 32c. The shape of the coil bobbin hole 32c is the same as or substantially the same as the outer shape of the coil bobbin 33. When the coil bobbin 33 is disposed in the coil bobbin hole 32c, the coil bobbin 33 does not rattle in the hole 32c. ing. An opening (coil bobbin insertion port) 32 d above the coil bobbin hole 32 is closed by the piston 1 when the bobbin body 32 is attached to the piston 1.

The coil bobbin 33 is built in the coil bobbin hole 32c. The coil bobbin 33 is sandwiched between the mounting surface of the piston 1 and the bobbin body 32, and prevents the coil bobbin 33 and the resonance coil 31 from being damaged by the inertial force generated by the reciprocating motion of the piston 1. The cross-sectional shape of the coil bobbin 33 is not a complete cylindrical shape such as an elliptical shape or a barrel shape.
A gap between the coil bobbin 33 and the bobbin body 32 is filled with an adhesive 33a.

  The terminal 34 is attached to the coil bobbin 33 as shown in FIGS. The terminal 34 is inserted into a terminal mounting hole 33 b formed in the coil bobbin 33. The resonance coil 31 is taken out of the bobbin body 32 through the terminal 34. The connection side 34a of the terminal 34 to the resonance coil 31 is located very close to the winding portion of the resonance coil 31, and the wiring of the resonance coil 31 is prevented from being disconnected by shortening the wiring. The side 34b of the terminal 34 opposite to the connection side 34a to the resonance coil 31 extends to the outside of the bobbin body 32, and the resistance temperature measuring element 51 (see FIG. 1) is connected to the connection side 34b.

  The resistance temperature measuring element 51 is a thermistor. As shown in FIG. 1, the resistance temperature measuring element 51 is embedded in each temperature measuring portion of the piston 1, and each resistance temperature measuring element 51 forms a series closed circuit with each corresponding resonance coil 31. ing. However, when the resistance value of each resistance temperature measuring element 51 changes with temperature, the induced current of each resonance coil 31 changes. Accordingly, the peak value of the AC voltage waveform of each receiving coil 22 through which each resonance coil 31 passes changes due to the electromagnetic induction action between both coils 31 and 22. For this reason, a voltage measuring device 54 such as an oscilloscope and a recording device 53 such as a personal computer are connected to each corresponding receiving coil 22, and the output value is monitored and recorded. By converting, it is possible to know the temperature of each resistance temperature measuring element 51, that is, the temperature of each temperature measuring section.

  The bobbin cover 35 is disposed on the upper surface of the coil bobbin 33 as shown in FIG. The bobbin cover 35 is attached to the coil bobbin 33 and is disposed between the terminal 34 and the piston 1. The bobbin cover 35 prevents the terminal 34 from jumping upward from the terminal mounting hole 33b. As a result, the terminal 34 is prevented from coming into contact with conductive parts such as the piston 1, and the circuit formed by the resistance temperature measuring element 51 is prevented from being short-circuited.

When the fixed side module 20 and the moving side module 30 are attached to the internal combustion engine, the positioning mechanism 40 changes the relative positional relation between the modules 20 and 30 so that the ferrite core 23 and the coil bobbin 33 are coaxial. To be provided.
When the stationary module 20 and the motion module 30 are attached to the internal combustion engine, the relative positional relationship between the modules 20 and 30 must be such that the ferrite core 23 and the coil bobbin 33 are coaxial. It is. This is because if the coaxiality is out of order, the ferrite core 23 and the coil bobbin 33 come into contact with each other, causing problems such as damage to the stationary module 20 or the moving module 30.
As shown in FIGS. 10 and 11, the positioning mechanism 40 includes a positioning pin 41, a pin mounting hole 42 provided on one of the fixed side module 20 and the motion side module 30, and a fixed side module. 20 and an insertion hole 43 (see FIG. 2) provided in the other of the movement side module 30 and into which the positioning pin 41 is inserted.

The positioning pin 41 is detachably attached to the pin attachment hole 42. The positioning pin 41 is detachably attached to the pin mounting hole 42 by, for example, forming a screw in the positioning pin 41 and the pin mounting hole 42 and screwing the positioning pin 41 into the pin mounting hole 42. The positioning pin 41 is attached to the pin attachment hole 42 when the modules 20 and 30 are attached to the internal combustion engine, and is removed from the pin attachment hole 42 at the time of measurement. The positioning pin 41 tapers toward the tip.
When both modules 20 and 30 are attached to the internal combustion engine, the coaxiality of the ferrite core 23 and the coil bobbin 33 is maintained by attaching the modules 20 and 30 to positions where the positioning pins 41 are inserted into the insertion holes 43.

Here, the operation of the portion common to the first and second embodiments of the present invention will be described.
(A) Since the stationary module 20 includes the protection member 27 that protects the coil wiring 26, the protection member 27 can protect the coil wiring 26. Further, since the protective member 27 is provided around the ferrite core 23, it is possible to prevent the transmission coil 21 and the reception coil 22 from being unwound from the ferrite core 23.
(B) Since the positioning mechanism 40 is provided, the relative positions of the stationary module 20 and the motion module 30 can be determined. As a result, it is possible to prevent the piston temperature sensor 10a from being damaged due to contact between the stationary module 20 and the moving module 30.

(C) Since the coil bobbin 33 is disposed in the coil bobbin hole 32c in which the coil bobbin insertion port 32d is closed by the piston 1, it is possible to prevent the resonance coil 31 attached to the coil bobbin 33 or the coil bobbin 33 from being damaged.
(D) The cross-sectional shape of the coil bobbin 33 is non-circular, and the shape of the coil bobbin hole 32c is the same as or substantially the same as the outer shape of the coil bobbin 33. Therefore, the coil bobbin 33 rotates with respect to the bobbin body 32. Can be prevented. As a result, the coil bobbin 33 and the terminal 34 attached to the coil bobbin 33 can be prevented from being damaged.
(E) Since the adhesive 33a is filled in the gap between the bobbin body 32 and the coil bobbin 33, it is possible to prevent the coil side bobbin 33 from vibrating with respect to the bobbin body 32 and damaging the motion side module 30.
(F) The connection side 34a of the terminal 34 to the resonance coil 31 is located very close to the winding portion of the resonance coil 31, and the wiring of the resonance coil 31 can be prevented from being disconnected by shortening the coil wiring. .
(G) Since the movement side module 30 includes the terminal 34 and the terminal 34 is inserted into the terminal mounting hole 33b of the coil bobbin 33, it is possible to prevent the wiring from being disconnected due to the vibration of the terminal 34.
(H) Since the motion side module 30 includes the bobbin cover 35, it is possible to prevent the circuit from being short-circuited due to the terminal 34 coming into contact with the piston 1 which is a conductive component.

(I) Since the collar 24 b is provided on the mounting screw portion 24 a of the stay 24, it is possible to prevent the screw 20 a from being loosened due to thermal expansion or swelling of the resin stay 24 and the mounting force of the stay 24 from being reduced.
(J) Since the collar 32 b is provided on the mounting screw portion 32 a of the bobbin body 32, it is possible to prevent the screw 30 a from loosening due to thermal expansion and swelling of the resin bobbin body 32 and a decrease in the mounting force of the bobbin body 32.
(K) Since the fixed module 20 includes the relay element 25, it is possible to prevent the coil wiring 26 from being disconnected as compared with the case where the relay element 25 is not provided.

Next, parts unique to each embodiment of the present invention will be described.
[Example 1] (FIGS. 1 to 14)
In the first embodiment of the present invention, as shown in FIG. 2, the stay 24 of the stationary module 20 has a two-divided structure 24d, 24e, and sandwiches and holds (fixes) the ferrite core 23. The stays 24d and 24e having a two-part structure are fixed with screws 24f. As shown in FIG. 6, at least one of the sandwiching portions 24g and 24h that sandwich the ferrite core 23 of the stays 24d and 24e having a two-divided structure is a triangular surface. When only one of the sandwiching portions 24g and 24h is a triangular surface, the other of the sandwiching portions 24g and 24h is a flat surface. A gap between the sandwiched portions 24g and 24h and the ferrite core 23 is filled with an adhesive 24i.
The relay element 25 is arranged between the stays 24d and 24e divided into two.

  In the first embodiment of the present invention, the ferrite core 23 is fixed by being sandwiched between the two-divided structure stays 24d and 24e, and the ferrite core 23 is prevented from coming off the stay 24 due to the influence of engine vibration or the like. The ferrite core 23 is fixed by the force by which the fixed-side module 20 is fixed to the support member 20b by the mounting screw portion 24a and the screw 20a, the tightening force of the screw 24f, and the clamping force by the set screw 28. Further, the fixing of the ferrite core 23 may be assisted by filling an adhesive (not shown) between the two-split structure stays 24d and 24e.

Since the ferrite core 23 is sandwiched and held by the two-divided structure stays 24d and 24e, as compared with a case where a ferrite core insertion hole is provided in a one-part structure stay and the ferrite core is inserted into the hole to hold the ferrite core. The ferrite core 23 is difficult to be removed from the stay 24 even if it is affected by engine vibration or the like.
Since at least one of the sandwiching portions 24g and 24h sandwiching the ferrite core 23 of the stays 24d and 24e having a two-divided structure is a triangular surface, both sandwiching portions 24g and 24h are flat surfaces. As compared with the above, the ferrite core 23 can be securely fixed, and the axial center position is fixed with high accuracy.
Since the gap between the sandwiched portions 24g and 24h and the ferrite core 23 is filled with the adhesive 24i, the ferrite core 23 is less likely to come off from the stay 24 than when the adhesive is not filled.

  The coil wiring 26 of the transmitting coil 21 and the receiving coil 22 is taken out so that a gap is formed between the two-divided structural stays 24d and 24e when the ferrite core 23 is sandwiched between the two-divided structural stays 24d and 24e. The relay element 25 is installed between the two-divided structure stays 24d and 24e. By connecting the coil wiring 26 to the external wiring 50 using the relay element 25, the external wiring 50 does not pass through the upper surface of the stay 24, and the motion-side module 30 and the fixed-side module are as much as the diameter of the external wiring 50. 20 can be secured widely, and it is possible to prevent the movement side module 30 and the external wiring 50 from coming into contact with each other and disconnecting the wiring. Moreover, since the coil wiring 26 does not go outside, the disconnection of the coil wiring 26 can be prevented.

[Example 2] (FIGS. 7 to 19)
In the second embodiment of the present invention, the ferrite core 23 is inserted (inserted) into a ferrite core hole 24j formed in the stay 24 as shown in FIG. The ferrite core hole 24j has a circular cross section. A gap between the ferrite core 23 and the stay 24 is filled with an adhesive 24k. The relay element 25 is disposed on the upper surface of the stay 24.

In the second embodiment of the present invention, since the gap between the ferrite core 23 and the stay 24 is filled with the adhesive 24k, the ferrite core 23 is less likely to come out of the stay 24 than when the adhesive is not filled. .
Since the relay element 25 is disposed on the upper surface of the stay 24, the external wiring 50 does not pass through the upper surface of the stay 24. Therefore, by making the thickness of the relay element 25 smaller than the thickness of the external wiring 50, a wide vertical clearance can be secured between the exercise side module 30 and the fixed side module 20. It is possible to prevent contact and disconnection.

DESCRIPTION OF SYMBOLS 1 Piston 10 Piston temperature measuring device 10a Piston temperature sensor 20 Fixed side module 20a Screw 20b Support member 21 Transmitting coil 22 Receiving coil 23 Ferrite core 24 Stay 24a Mounting screw part 24b Collar 24d, 24e 2 divided structure stays 24g, 24h 2 divided Structure stay sandwiching portions 24i, 24k Adhesive 25 Relay element 26 Coil wiring 27 Protective member 28 Set screw 30 Motion side module 30a Screw 31 Resonant coil 32 Bobbin body 32a Mounting screw portion 32b Collar bobbin hole 32d Coil bobbin hole Coil bobbin insertion Port 33 Coil bobbin 33a Adhesive 34 Terminal 35 Bobbin cover 40 Positioning mechanism 41 Positioning pin 42 Pin mounting hole 43 Insertion hole 50 External wiring 51 Resistance temperature measuring element 52 High frequency transmission / reception device 53 recording device 54 the voltage measuring device 55 calculating unit

Claims (3)

Having a stationary module and a moving module,
The stationary module, pressing the ferrite core, a stay with a hole ferrite core hole and the ferrite core setscrew is inserted, the side surfaces of the ferrite core is screwed for locking screw hole of the stay A set screw, and an adhesive provided in a gap between the ferrite core and the stay ,
The said set screw is a piston temperature measuring device which has a piston temperature measuring sensor which has pressed the side surface of the said ferrite core from the both sides of this ferrite core .   The fixed-side module includes a transmission coil, a reception coil, an external wiring disposed outside the fixed-side module, and a relay element provided between the transmission coil and the reception coil. A piston temperature measuring device having the piston temperature measuring sensor according to claim 1. The ferrite core of the fixed side module has the transmitting coil and the receiving coil attached thereto,
The stay of the fixed side module holds the ferrite core,
The piston temperature measuring device having a piston temperature measuring sensor according to claim 2, wherein the relay element of the fixed side module is disposed on an upper surface of the stay.

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