JP3787569B2 - Temperature sensor - Google Patents

Description

  The present invention relates to a temperature sensor that includes a thermistor made of a semiconductor such as a metal oxide, a metal resistor, or the like as a temperature sensing element, and the temperature sensing element is housed in a metal cap or a metal tube.

  Conventionally, a sheath member in which a temperature sensing element is connected to the front end side and a metal core wire to which a lead wire for connecting an external circuit is connected to the rear end side is insulated and held, and the temperature sensing element is housed inside the sheath member A metal cap joined over the circumferential direction of the member, and a mounting member having a mounting seat that supports the sheath member in a state in which the metal cap and the distal end side portion of the sheath member are exposed to the outside and abuts the sensor mounting position. A temperature sensor is known (Patent Document 1 (FIG. 4), Patent Document 2 (FIG. 1)).

  In addition, a cylindrical metal tube extending in the axial direction with the tip side closed, a temperature sensitive element housed inside the metal tube and whose electrical characteristics change according to temperature, and a state where the tip side portion of the metal tube is exposed to the outside A temperature sensor is known that includes a mounting member that supports a metal tube and has a mounting seat that contacts a sensor mounting position (Patent Document 1 (FIGS. 1 and 2)).

These temperature sensors are used to detect the temperature of a measurement object (exhaust gas, etc.) in a vibrated environment such as in the catalytic converter of an automobile and in an exhaust pipe.
JP 2002-350239 A JP 2000-162051 A

  However, in the conventional temperature sensor, when the frequency band of vibration generated in the sensor installation environment and the resonance frequency (primary resonance frequency) of the sensor overlap, the sensor vibrates greatly due to resonance, and the internal temperature of the sensor is increased. There is a risk of disconnection of the electrical path, breakage of the sheath member (or metal tube), and the like.

  In particular, the longer the tip protrusion dimension in the axial direction from the mounting seat of the mounting member to the tip of the metal cap, the more often the resonance frequency of the sensor overlaps with the frequency band of vibration generated in the sensor installation environment.

  As a method for preventing such disconnection or breakage, for example, the dimension in the axial direction (tip protruding dimension) from the mounting seat of the mounting member to the tip of the metal cap (or metal tube) in the temperature sensor is used. A method of setting it short can be considered.

  However, depending on the sensor installation environment, the distance from the sensor mounting position where the mounting seat abuts to the temperature detection position may be far away, and when used in such applications, the tip protrusion dimension can be shortened. There is a limit, and it is difficult to prevent disconnection or breakage due to resonance.

  Therefore, the present invention has been made in view of such problems, and is a temperature for detecting the temperature of an object to be measured in an environment with intense vibration, such as an exhaust pipe or an intake pipe of an internal combustion engine or a hydrogen distribution pipe of a fuel cell vehicle. An object of the present invention is to provide a temperature sensor that can prevent disconnection or breakage due to resonance even when the sensor is used in an installation environment where the distance from the sensor mounting position to the temperature detection position is long.

  In order to achieve this object, the invention according to claim 1 is characterized in that a temperature-sensitive element whose electrical characteristics change with temperature is connected to the front end side, and a lead wire for external circuit connection is connected to the rear end side. A metal member in which the inner circumference of the rear end side is joined over the circumferential direction of the outer circumference on the front end side of the sheath member in a form in which the sheath member that insulates and holds the metal core wire and the cylindrical shape that extends in the axial direction is housed inside The cap, the metal cap, and the sheath member support the sheath member by surrounding the outer peripheral surface of the sheath member in a state where the distal end side portion is exposed to the outside, and directly or indirectly through another member with respect to the sensor mounting position. And a mounting member having a mounting seat that abuts, and a tip protrusion dimension in the axial direction from the mounting seat of the mounting member to the tip of the metal cap is 2 [Mm] or more, and having an outer diameter smaller than the maximum outer diameter dimension of the mounting seat, a joint portion that surrounds the periphery of the sheath member in the radial direction on the distal end side of the mounting seat, and is joined to the sheath member; A vibration reinforcing portion having an outer diameter larger than the maximum outer diameter size of the mounting seat and smaller than the maximum outer diameter size of the mounting seat, and being disposed surrounding the sheath member in the radial direction between the mounting seat and the joint portion; It is a temperature sensor characterized by including.

  This temperature sensor has a tip projection dimension of 20 mm or more from the mounting seat to the tip of the metal cap, and the tip projection dimension is long. Therefore, the installation environment has a distance from the sensor mounting position to the temperature detection position. Can be used.

  Since the temperature sensor mounting member has a vibration reinforcing portion between the mounting seat and the joint portion, the axial dimension of the region surrounding the sheath member is ensured larger than that of the mounting member having no vibration reinforcing portion. can do.

  And since the outer diameter dimension of a vibration reinforcement part is larger than the largest outer diameter dimension of a junction part, compared with a junction part, thickness is thick and intensity | strength becomes high. For this reason, the attachment member having the vibration reinforcement portion between the attachment seat and the joint portion has a configuration in which the joint portion is simply extended in the axial direction without the attachment member or vibration reinforcement portion having no vibration reinforcement portion. Compared to the member, the overall strength of the attachment member is increased, and the sheath member can be more firmly supported against vibration. As a result, this temperature sensor can improve the vibration resistance of the sensor itself and can set the resonance frequency of the sensor to a different frequency as compared with a temperature sensor having a mounting member that does not have a vibration reinforcing portion. The resonance frequency of the sensor can be set to a frequency band different from the frequency band of vibration generated in the sensor installation environment.

  Further, since the outer diameter of the vibration reinforcing portion is smaller than the maximum outer diameter of the mounting seat, the vibration reinforcing portion does not interfere with the sensor mounting position when the temperature sensor is disposed at the sensor mounting position.

  For this reason, even in the case of using the temperature sensor of the present invention having the vibration reinforcing portion in the same application as the conventional temperature sensor not including the vibration reinforcing portion, the contact portion of the mounting member with the sensor mounting position is Since there is no change from the mounting seat, the arrangement position of the temperature-sensitive element when the temperature sensor is installed can be determined with reference to the mounting seat of the mounting member as in the prior art.

  Therefore, according to the temperature sensor of the present invention, even when used in an installation environment where the distance from the sensor mounting position to the temperature detection position is far away, the resonance frequency of the sensor is a frequency band of vibrations generated in the sensor installation environment. Therefore, it is possible to prevent disconnection due to resonance and breakage of the sheath member.

  The joining means between the joint portion of the attachment member and the sheath member is not particularly limited, and for example, joining means such as caulking joining, laser welding, plasma welding, argon welding, electron beam welding, brazing joining, etc. are adopted. Can do.

  Further, the maximum outer diameter dimension of the joint means the diameter dimension of the maximum circumscribed circle that surrounds the largest cross-sectional shape among the cross-sectional shapes of the joint in the cross section perpendicular to the axial direction. Further, the maximum outer diameter dimension of the mounting seat means the diameter dimension of the maximum circumscribed circle surrounding the largest cross-sectional shape among the cross-sectional shapes of the mounting seat in the cross section perpendicular to the axial direction.

  Next, in the above-described temperature sensor, as described in claim 2, the vibration reinforcing portion is configured such that the length dimension in the axial direction is not less than a value equivalent to 20% of the tip protrusion dimension and not more than a value equivalent to 60%. It is good to be.

  In other words, by forming the vibration reinforcing portion so that the length dimension in the axial direction is equal to or more than 20% of the tip protrusion dimension, the attachment member is reliably increased in strength and the sheath member is more resistant to vibration. It can be firmly supported. A temperature sensor including such a vibration reinforcing portion can reliably set the resonance frequency of the sensor to a different value compared to a temperature sensor not including the vibration reinforcing portion.

  Further, by forming the vibration reinforcing portion so that the length dimension in the axial direction is equal to or less than 60% of the tip protrusion dimension, it is possible to avoid the distance between the mounting member and the temperature sensing element from being shortened, and the temperature sensor It is possible to avoid an increase in the heat capacity in the vicinity of the temperature sensitive element. As a result, even when the temperature of the measurement object changes suddenly, the temperature change of the temperature sensing element is not greatly delayed from the temperature change of the measurement object, and the temperature sensor response is prevented from deteriorating. it can.

  Therefore, according to the temperature sensor of the present invention, the resonance frequency of the sensor can be set to a frequency band different from the frequency band of vibration generated in the sensor installation environment, and it is possible to prevent disconnection due to resonance and breakage damage of the sheath member. It is possible to prevent the responsiveness to the temperature change of the measurement object from being lowered, and to prevent the sensor detection accuracy from being lowered.

  In order to surely avoid an increase in the heat capacity of the temperature sensor in the vicinity of the temperature sensing element, the length dimension in the axial direction of the vibration reinforcing portion is not less than a value equivalent to 20% of the tip protrusion dimension and not more than a value equivalent to 60%. It is preferable to set the sum of the same length dimension of the vibration reinforcing portion and the length dimension in the axial direction of the joint portion to a value equivalent to 70% or less of the tip protruding dimension.

  Next, in the above-described temperature sensor, as described in claim 3, the difference in diameter between the outer diameter of the portion corresponding to the vibration reinforcing portion of the sheath member and the inner diameter of the vibration reinforcing portion is 0 to 0. .3 [mm] is preferable.

  That is, by setting the diameter difference between the outer diameter dimension of the sheath member and the inner diameter dimension of the vibration reinforcement portion to be at least 0.3 [mm] or less, the attachment member can be attached to a portion of the sheath member corresponding to the vibration reinforcement portion. The movable range can be limited within a certain range. Thereby, this temperature sensor can set the resonant frequency of a sensor to a different frequency compared with the temperature sensor which does not have a vibration reinforcement part.

  In particular, when the diameter difference between the outer diameter dimension of the sheath member and the inner diameter dimension of the vibration reinforcing portion is 0 [mm], the inner peripheral surface of the vibration reinforcing portion and the outer peripheral surface of the sheath member are in contact with each other, The attachment member can restrict the movement of the sheath member not only in the joint portion but also in the vibration reinforcing portion, and can reliably support the sheath member.

Next, in the above-described temperature sensor, as described in claim 4, the joint portion and the vibration reinforcing portion may be integrally formed with the mounting member.
As described above, when the joint portion and the vibration reinforcing portion are integrally formed with the mounting member, the cost for molding can be reduced as compared with the case where the joint portion, the vibration reinforcing portion, and the mounting member are individually molded. Can do.

  In addition, when the joint portion and the vibration reinforcing portion are integrally formed with the mounting member, compared to the case where the joint portion, the vibration reinforcing portion, and the mounting member are individually molded and then joined, the mounting member and the vibration reinforcing portion are formed. And the strength between the joint portion and the vibration reinforcing portion can be maintained well.

  Next, the invention according to claim 5 made to achieve the above object is accommodated in a cylindrical metal tube extending in the axial direction and the inside of the tip side of the metal tube, and the electrical characteristics change depending on the temperature. While supporting the metal tube by surrounding the outer peripheral surface of the metal tube with the temperature sensing element and the tip side portion of the metal tube exposed to the outside, the sensor is attached directly or indirectly through another member. And a mounting member having a mounting seat in contact with the mounting member, the tip protruding dimension in the axial direction from the mounting seat of the mounting member to the tip of the metal tube is 20 [mm] or more, and the maximum outer diameter of the mounting seat It has an outer diameter smaller than the dimensions, and is joined to the metal tube by surrounding the metal tube in the radial direction on the tip side of the mounting seat. The outer diameter of the joint portion is larger than the maximum outer diameter size of the joint portion and smaller than the maximum outer diameter size of the mounting seat, and is disposed between the mounting seat and the joint portion so as to surround the periphery of the metal tube in the radial direction. And a vibration reinforcing part.

  In this temperature sensor, the tip protruding dimension from the mounting seat to the tip of the metal tube is 20 mm or more, and the tip protruding dimension is long. Therefore, the installation environment where the distance from the sensor mounting position to the temperature detection position is long. Can be used.

  The mounting member for this temperature sensor has a vibration reinforcing part between the mounting seat and the joint, so that the axial dimension of the region surrounding the metal tube is ensured larger than that of the mounting member that does not have the vibration reinforcing part. can do.

  And since the outer diameter dimension of a vibration reinforcement part is larger than the largest outer diameter dimension of a junction part, compared with a junction part, thickness is thick and intensity | strength becomes high. For this reason, the attachment member having the vibration reinforcement portion between the attachment seat and the joint portion has a configuration in which the joint portion is simply extended in the axial direction without the attachment member or vibration reinforcement portion having no vibration reinforcement portion. Compared with the member, the overall strength of the mounting member is increased, and the metal tube can be more firmly supported against vibration. As a result, this temperature sensor can improve the vibration resistance of the sensor itself and can set the resonance frequency of the sensor to a different frequency as compared with a temperature sensor having a mounting member that does not have a vibration reinforcing portion. The resonance frequency of the sensor can be set to a frequency band different from the frequency band of vibration generated in the sensor installation environment.

  Further, since the outer diameter of the vibration reinforcing portion is smaller than the maximum outer diameter of the mounting seat, the vibration reinforcing portion does not interfere with the sensor mounting position when the temperature sensor is disposed at the sensor mounting position.

  For this reason, even in the case of using the temperature sensor of the present invention having the vibration reinforcing portion in the same application as the conventional temperature sensor not including the vibration reinforcing portion, the contact portion of the mounting member with the sensor mounting position is Since there is no change from the mounting seat, the arrangement position of the temperature-sensitive element when the temperature sensor is installed can be determined with reference to the mounting seat of the mounting member as in the prior art.

  Therefore, according to the temperature sensor of the present invention, even when used in an installation environment where the distance from the sensor mounting position to the temperature detection position is far away, the resonance frequency of the sensor is a frequency band of vibrations generated in the sensor installation environment. Therefore, it is possible to prevent disconnection due to resonance and breakage of the metal tube.

  In addition, the joining means of the junction part of an attachment member and a metal tube is not specifically limited, For example, taking joining means, such as caulking joining, laser welding, plasma welding, argon welding, electron beam welding, brazing joining, is taken. Can do.

  Next, in the temperature sensor including the above-described metal tube, as described in claim 6, the vibration reinforcing portion has a length dimension in the axial direction of 20% or more and 60% or less of the tip protrusion dimension. It is good to be comprised so that it may become.

  In other words, by forming the vibration reinforcing portion so that the length dimension in the axial direction is equal to or more than 20% of the tip protrusion dimension, the mounting member is reliably increased in strength and the metal tube is more resistant to vibration. It can be firmly supported. A temperature sensor including such a vibration reinforcing portion can reliably set the resonance frequency of the sensor to a different value compared to a temperature sensor not including the vibration reinforcing portion.

  Further, by forming the vibration reinforcing portion so that the length dimension in the axial direction is equal to or less than 60% of the tip protrusion dimension, it is possible to avoid the distance between the mounting member and the temperature sensing element from being shortened, and the temperature sensor It is possible to avoid an increase in the heat capacity in the vicinity of the temperature sensitive element. As a result, even when the temperature of the measurement object changes suddenly, the temperature change of the temperature sensing element is not greatly delayed from the temperature change of the measurement object, and the temperature sensor response is prevented from deteriorating. it can.

  Therefore, according to the temperature sensor of the present invention, the resonance frequency of the sensor can be set to a frequency band different from the frequency band of vibration generated in the sensor installation environment, and it is possible to prevent disconnection due to resonance and breakage damage of the metal tube, It is possible to prevent the responsiveness to the temperature change of the measurement object from being lowered, and to prevent the sensor detection accuracy from being lowered.

  In order to surely avoid an increase in the heat capacity of the temperature sensor in the vicinity of the temperature sensing element, the length dimension in the axial direction of the vibration reinforcing portion is not less than a value equivalent to 20% of the tip protrusion dimension and not more than a value equivalent to 60%. It is preferable to set the sum of the same length dimension of the vibration reinforcing portion and the length dimension in the axial direction of the joint portion to a value equivalent to 70% or less of the tip protruding dimension.

  Next, in the temperature sensor including the above-described metal tube, as described in claim 7, the difference in diameter between the outer diameter dimension of the portion corresponding to the vibration reinforcement portion and the inner diameter dimension of the vibration reinforcement portion of the metal tube is 0 to 0.3 [mm].

  That is, by setting the diameter difference between the outer diameter dimension of the metal tube and the inner diameter dimension of the vibration reinforcing portion to be at least 0.3 [mm] or less, the attachment member can be attached to the portion of the metal tube corresponding to the vibration reinforcing portion. The movable range can be limited within a certain range. Thereby, this temperature sensor can set the resonant frequency of a sensor to a different frequency compared with the temperature sensor which does not have a vibration reinforcement part.

  In particular, when the diameter difference between the outer diameter dimension of the metal tube and the inner diameter dimension of the vibration reinforcing portion is 0 [mm], the inner peripheral surface of the vibration reinforcing portion and the outer peripheral surface of the metal tube are in contact with each other, The attachment member can restrict the movement of the metal tube not only at the joint portion but also at the vibration reinforcing portion, and can reliably support the metal tube.

Next, in the above-described temperature sensor, as described in claim 8, the joining portion and the vibration reinforcing portion may be integrally formed with the mounting member.
As described above, when the joint portion and the vibration reinforcing portion are integrally formed with the mounting member, the cost for molding can be reduced as compared with the case where the joint portion, the vibration reinforcing portion, and the mounting member are individually molded. Can do.

  In addition, when the joint portion and the vibration reinforcing portion are integrally formed with the mounting member, compared to the case where the joint portion, the vibration reinforcing portion, and the mounting member are individually molded and then joined, the mounting member and the vibration reinforcing portion are formed. And the strength between the joint portion and the vibration reinforcing portion can be maintained well.

The preferred embodiments of the present invention will be described below.
In addition, this invention is not limited to the following embodiment at all, and it cannot be overemphasized that various forms may be taken as long as it belongs to the technical scope of this invention.

FIG. 1 is a partially broken sectional view showing a structure of a temperature sensor 1 according to an embodiment of the present invention.
The temperature sensor 1 includes a sheath member 8 that insulates and holds a pair of metal core wires 7, a cylindrical metal cap 14 that extends in the axial direction with the distal end closed, and an attachment member 4 that supports the sheath member 8. Has been. The axial direction is the longitudinal direction of the temperature sensor and corresponds to the vertical direction in FIG. Moreover, the front end side in the temperature sensor 1 is a lower side in the figure, and the rear end side in the temperature sensor 1 is an upper side in the figure.

  The temperature sensor 1 includes a thermistor element 2 as a temperature sensing element inside a metal cap 14, and is attached to a distribution pipe such as an intake pipe of an internal combustion engine or a hydrogen distribution pipe of a fuel cell vehicle, for example, This corresponds to a so-called vehicle temperature sensor that can be used for detecting the temperature of the measurement target gas by disposing the element 2 in the flow pipe through which the measurement target gas flows. The thermistor element 2 changes its electrical characteristics (electric resistance value) depending on the temperature.

  The metal core wire 7 has a tip end connected to the electrode wire of the thermistor element 2 by resistance welding, and a rear end connected to the crimping terminal 11 by resistance welding. Thereby, the rear end side of the metal core wire 7 is connected to a lead wire 12 for connecting an external circuit (for example, an electronic control unit (ECU) of a vehicle) via the crimping terminal 11.

  The pair of metal core wires 7 are insulated from each other by the insulating tube 15, and the pair of crimp terminals 11 are insulated from each other by the insulating tube 15. The lead wire 12 is obtained by coating a conductive wire with an insulating coating material. The lead wire 12 is disposed in a state of penetrating the inside of the auxiliary ring 13 made of heat resistant rubber.

  Although not shown in detail, the sheath member 8 is a metal that electrically insulates between a metal outer cylinder, a pair of metal core wires 7 made of a conductive metal, and the outer cylinder and the two metal core wires 7. And an insulating powder for holding the core wire 7.

  The metal cap 14 is made of a corrosion-resistant metal (for example, a stainless alloy such as SUS316), has a cylindrical shape that extends in the axial direction with the front end side 31 closed, and has a configuration in which the cylindrical rear end side 32 is open. ing. The metal cap 14 accommodates the thermistor element 2 and the epoxy anti-vibration material 17 inside the front end side, while the inner peripheral surface of the rear end side 32 is overlapped with the outer peripheral surface of the sheath member 8 and is applied in the circumferential direction. The sheath member 8 is fixed by being fastened and electron beam welded.

In addition, the cap welding part 64 straddling the rear end side 32 of the metal cap 14 and the sheath member 8 (specifically, the outer cylinder of the sheath member 8) is formed by the welding operation.
The metal attachment member 4 includes a hexagonal nut portion 51 protruding radially outward, a screw portion 52 having a thread groove, and a rear end side extending from the rear end of the hexagonal nut portion 51 toward the rear end side in the axial direction. And a sheath portion 42. The attachment member 4 includes an attachment seat 45 formed as a distal end surface of the hexagon nut portion 51, a joint portion 43 joined to the sheath member 8 on the distal end side of the attachment seat 45, and the attachment seat 45 and the joint portion 43. And a vibration reinforcing portion 47 surrounding the periphery of the sheath member 8 in the radial direction.

  The attachment member 4 surrounds the outer peripheral surface of the sheath member 8 and supports the sheath member 8 with at least the metal cap 14 and the distal end portion of the sheath member 8 exposed to the outside.

  The attachment member 4 is fixed to a sensor attachment position formed in the flow pipe in a state where an annular seal ring 48 made of an elastic material (for example, heat resistant rubber) is disposed on the distal end side of the attachment seat 45. At this time, the mounting seat 45 is in contact with the sensor mounting position (sensor mounting surface) indirectly through the seal ring 48 to prevent a gap from being generated between the temperature sensor 1 and the flow pipe, and measurement is performed. Prevent the target gas from leaking outside.

The attachment member 4 is fixed to the sensor attachment position by screwing the screw portion 52 into a screw groove formed around the sensor attachment position. Further, the mounting member 4 is determined by the mounting seat 45 indirectly contacting the sensor mounting position via the seal ring 48, whereby the arrangement position in the insertion direction at the sensor mounting position is determined. Is formed in an annular shape so that the sheath member 8 can be inserted into the sheath member 8 so as to surround the periphery of the sheath member 8 in the radial direction. Further, the thickness of the joint portion 43 (diameter difference between the annular inner diameter dimension and the outer diameter dimension) is set to be thin so that deformation by caulking is possible.

  The rear end side sheath portion 42 is formed in an annular shape, and includes a first step portion 44 located on the front end side and a second step portion 46 having an outer diameter smaller than that of the first step portion 44. It has a shape. Among these, the second step portion 46 is set to have a thin thickness dimension (diameter difference between the annular inner diameter dimension and the outer diameter dimension) so that deformation by caulking is possible.

  Then, after the sheath member 8 is inserted into the attachment member 4, the radially inward caulking operation and the electron beam welding operation are performed on each of the joint portion 43 and the second step portion 46. As a result, the sheath member 8 is supported by surrounding the outer peripheral surface of the sheath member 8. That is, the sheath member 8 is fixed to the attachment member 4 by being bonded to the bonding portion 43 and the second step portion 46.

  The welding operation forms a distal end side welded portion 62 straddling the joint portion 43 and the sheath member 8 (specifically, the outer tube of the sheath member 8), and the second step portion 46 and the sheath member 8 (specifically, the details). , The rear end side welding part 63 straddling the outer cylinder of the sheath member 8 is formed.

  At this time, the relative position of the attachment member 4 and the sheath member 8 is set so that the tip protrusion dimension L1 in the axial direction from the attachment seat 45 of the attachment member 4 to the tip of the metal cap 14 is 45 [mm]. .

  The vibration reinforcing portion 47 is formed in an annular shape through which the sheath member 8 can be inserted, and the sheath member 8 is fixed to the attachment member 4 so as to surround the periphery of the sheath member 8 in the radial direction. Limit the range of movement.

  The inner diameter dimension in the cross section perpendicular to the axial direction of the vibration reinforcing portion 47 is set to 2.6 [mm], and the outer diameter dimension (2.5 [mm] in the cross section perpendicular to the axial direction of the sheath member 8 is set. ]) And larger than 0.1 [mm].

  Moreover, the outer diameter dimension in a cross section perpendicular | vertical to the axial direction of the vibration reinforcement part 47 is 5.0 [mm], is larger than the largest outer diameter dimension (3.2 [mm]) of the junction part 43, and a mounting seat It is set smaller than the maximum outer diameter of 45 (15.0 [mm]).

Further, the vibration reinforcing portion 47 is configured such that its length in the axial direction (hereinafter also referred to as a reinforcing portion dimension L2) is set to 9.0 [mm].
The maximum outer diameter dimension of the mounting seat 45 means the diameter dimension of the maximum circumscribed circle surrounding the largest cross-sectional shape among the cross-sectional shapes of the mounting seat 45 in the cross section perpendicular to the axial direction. This corresponds to the diameter dimension of the maximum circumscribed circle in the cross section perpendicular to the axial direction of the hexagon nut 51. Further, the caulking position of the joint portion 43 is deformed to 3.0 [mm] by the caulking operation.

  Further, a metal tubular joint member 6 is joined to the mounting member 4 on the radially outer side of the first step portion 44 of the rear end side sheath portion 42. Specifically, the joint member 6 is connected to the first step portion 44 of the rear end side sheath portion 42 so that the outer peripheral surface of the first step portion 44 of the rear end side sheath portion 42 overlaps the inner peripheral surface of the joint member 6. The joint member 6 and the first step portion 44 are laser welded in the circumferential direction. By performing this laser welding, a joint welding portion 61 is formed across the first step portion 44 of the rear end side sheath portion 42 and the joint member 6.

  The joint member 6 is a state in which the crimping terminal 11, the insulating tube 15, and the auxiliary ring 13 are accommodated therein, and a portion corresponding to the auxiliary ring 13 is circularly or polygonally crimped inward in the radial direction. While maintaining airtightness between the auxiliary ring 13 and the auxiliary ring 13, it is crimped and joined.

  Then, the external circuit connected to the temperature sensor 1 via the lead wire 12 takes out the electrical characteristics of the thermistor element 2 that changes according to the temperature of the measurement object, and measures the measurement target gas based on the extracted electrical characteristics. Detect the temperature. Thus, the temperature sensor 1 is used for temperature detection by being connected to an external circuit.

  As described above, the temperature sensor 1 has the tip protrusion dimension L1 from the mounting seat 45 to the tip of the metal cap 14 of 45 [mm], and the tip protrusion dimension L1 is formed long. It can be used in an installation environment where the distance from the temperature detection position is long. That is, the temperature sensor 1 can arrange the thermistor element 2 at a substantially central position of the flow pipe even in a flow pipe having a large pipe diameter, and can detect the temperature of the measurement target gas at the substantially central position of the flow pipe. can do.

  In addition, since the attachment member 4 of the temperature sensor 1 includes the vibration reinforcement portion 47 between the attachment seat 45 and the joint portion 43, the sheath member 8 is provided in comparison with the conventional attachment member that does not have the vibration reinforcement portion. A large axial dimension of the surrounding region can be ensured. For this reason, the attachment member 4 can restrict | limit the movable range of the sheath member 8 narrower than before, and can change the vibration characteristic of the sheath member 8. FIG.

  Since the vibration reinforcing portion 47 has an outer diameter dimension larger than the maximum outer diameter dimension of the joint portion 43, the vibration reinforcing portion 47 is thicker and stronger than the joint portion 43. For this reason, the attachment member 4 having the vibration reinforcement portion 47 is an attachment member as compared with an attachment member having no vibration reinforcement portion or an attachment member having a configuration in which the joint portion is simply extended in the axial direction without the vibration reinforcement portion. The overall strength of the sheath member 8 is increased, and the sheath member 8 can be supported more firmly against vibration.

  Thereby, the temperature sensor 1 can set the resonant frequency of a sensor to a different frequency compared with the temperature sensor provided with the attachment member which does not have a vibration reinforcement part. The resonance frequency of the temperature sensor 1 is set to a frequency band different from the frequency band (for example, a band of 0 to 1 [kHz]) of vibration generated in the flow pipe of the present embodiment.

  Further, since the outer diameter of the vibration reinforcing portion 47 is smaller than the maximum outer diameter of the mounting seat 45, the vibration reinforcing portion 47 is used when the temperature sensor 1 is disposed at the sensor mounting position of the flow pipe. There is no interference with the mounting position. For this reason, the temperature sensor 1 can be used for the same application as a conventional temperature sensor that does not include a vibration reinforcing portion.

  Therefore, according to the temperature sensor 1 of the present embodiment, even when used in an installation environment where the distance from the sensor mounting position of the flow pipe to the temperature detection position is long, the resonance frequency of the sensor is generated in the sensor installation environment. Since it can be set to a frequency band different from the frequency band of the vibration to be performed, disconnection due to resonance and breakage and breakage of the sheath member 8 can be prevented.

  In the temperature sensor 1, the inner diameter of the vibration reinforcing portion 47 is set to 2.6 [mm], and the inner diameter of the vibration reinforcing portion 47 and the outer diameter of the sheath member 8 (2.5 [mm] ) Is 0.1 [mm].

  For this reason, the vibration reinforcing part 47 is in a state where the gap dimension between its inner peripheral surface and the outer peripheral surface of the sheath member 8 is 0.05 [mm] (a dimension corresponding to a half of the diameter difference). The periphery of the sheath member 8 in the radial direction can be surrounded, and the movable range of the portion of the sheath member 8 corresponding to the vibration reinforcing portion 47 can be limited within a certain range. In this way, by limiting the movable range of the sheath member 8 within a certain range, the vibration characteristics of the sheath member 8 can be improved as compared with the case where the movable range is not limited, and the vibration resistance of the temperature sensor is reduced. Can be improved.

  Here, an evaluation result of evaluating the strength against vibration using a plurality of temperature sensors having a structure similar to that of the temperature sensor 1 and having the reinforcement portion dimension L2 of the vibration reinforcement portion 47 set to different dimensions will be described. To do.

  The evaluation is performed by applying vibration to the temperature sensor 1 with the metal cap 14 (in other words, the thermistor element 2) heated so that the sensor resistance value of the temperature sensor 1 becomes a resistance value corresponding to 850 ° C. This was carried out by measuring the endurance time (normal operation possible time) during which the sensor 1 can normally detect the temperature. At this time, the vibration applied to the temperature sensor 1 reciprocates between a lower limit value (0 [Hz]) and an upper limit value (3000 [Hz]) in a vibration frequency band of 0 to 3000 [Hz]. The vibration frequency is changed at a rate of 1 [Hz] per second. The acceleration of the vibrator that applies vibration to the temperature sensor 1 was 20 [G].

  In this evaluation, the time required from the time when vibration is applied to the temperature sensor 1 to the time when the electrical path inside the sensor is broken or when the outer cylinder of the sheath member 8 is broken or broken is measured as the normal operation possible time. did. In addition, about the damage of the sheath member 8, it confirmed visually. Regarding disconnection of the electrical path inside the sensor, a thermistor element 2 and a fixed resistor (installed outside the temperature sensor 1) are connected in series to form a voltage dividing circuit. When a voltage of [V] was applied and 5 [V] was output from the voltage dividing point, it was determined that the disconnection occurred.

  Further, the temperature sensors used in this evaluation are two types of temperature sensors having a tip protrusion dimension L1 of 20 [mm] and 45 [mm], respectively, and the reinforcement part dimension L2 of the vibration reinforcing part 47 is the tip protrusion dimension L1. 12 types of temperature sensors set to 0% equivalent value, 10% equivalent value, 20% equivalent value, 40% equivalent value, 60% equivalent value, and 70% equivalent value. Note that the temperature sensor in which the reinforcing portion dimension L2 of the vibration reinforcing portion 47 is equivalent to 0% of the tip protruding dimension L1 is a temperature sensor having only a joint portion that does not include the vibration reinforcing portion, and is evaluated as a comparative example. went.

  Then, based on the evaluation result, when the normal operation possible time is 100 hours or more, ○ mark, when it is 50 hours or more and less than 100 hours, Δ mark, and when it is less than 50 hours, X mark, The strength against vibration of the temperature sensor was determined. The determination results are shown in [Table 1].

  According to the determination result, the reinforcing part dimension L2 of the vibration reinforcing part 47 is equal to or more than 20% of the tip protruding dimension L1 in any temperature sensor having the tip protruding dimension L1 of 20 [mm] and 45 [mm]. In all cases, the determination result is a circle mark, and the strength against vibration is high, and it can be understood that the temperature can be detected appropriately even when used for a long time.

  In addition, when the reinforcing portion dimension L2 of the vibration reinforcing portion 47 is a value corresponding to 10% of the tip protruding dimension L1, the determination result is a △ mark, which cannot be used for a long time exceeding 100 hours. It can be seen that the strength against vibration is higher than that of a conventional temperature sensor that does not include a vibration reinforcement portion (a temperature sensor in which the reinforcement portion dimension L2 is equivalent to 0% of the tip protrusion dimension L1).

  Therefore, according to the determination result based on the evaluation result of this evaluation, the strength against vibration of the temperature sensor can be improved by setting the reinforcing portion dimension L2 of the vibration reinforcing portion 47 to a value equivalent to 20% or more of the tip protruding dimension L1. It can be seen that a temperature sensor that can withstand use over a long period of time can be realized.

  In addition, if the distance between the thermistor element 2 and the attachment member 4 is shortened by setting the reinforcement part dimension L2 of the vibration reinforcement part 47 to be large, the influence of the temperature of the attachment member 4 on the temperature detection of the thermistor element 2 becomes large. There is a possibility that the response speed of the thermistor element 2 to the temperature change of the measurement target gas is slow.

  Therefore, in order to prevent a decrease in response speed in temperature detection, it is desirable to set the distance between the thermistor element 2 and the mounting member 4 to a certain value or more, and the reinforcing portion dimension L2 of the vibration reinforcing portion 47 is set to protrude from the tip. It may be set to 60% or less of the dimension L1.

  That is, the temperature sensor in which the reinforcing portion dimension L2 is set to 60% or less of the tip protrusion dimension L1 can avoid the distance between the mounting member 4 and the thermistor element 2 from being shortened, and the thermistor element 2 of the temperature sensors. It is possible to avoid an increase in the heat capacity in the vicinity of. As a result, even when the temperature of the measurement target gas changes abruptly, the temperature change of the thermistor element 2 is not greatly delayed with respect to the temperature change of the measurement target gas, and the responsiveness of the temperature sensor is prevented from deteriorating. it can.

  In the above-described embodiment (hereinafter referred to as the first embodiment), the temperature sensor configured to include a metal cap that covers the distal end portion of the sheath member has been described. However, the present invention is limited to the above-described embodiment. There is no.

Next, as a second embodiment, a second temperature sensor that includes a metal tube that covers all of the portion of the sheath member that is disposed on the distal end side of the attachment member will be described.
FIG. 2 is a partially broken sectional view showing the structure of the second temperature sensor 101 including a metal tube.

  The second temperature sensor 101 includes a second sheath member 108 that insulates and holds a pair of metal core wires 7, a cylindrical metal tube 114 that extends in the axial direction with the distal end closed, and a second attachment member 104 that supports the metal tube 114. And is configured.

  The second temperature sensor 101 includes the thermistor element 2 as a temperature sensing element inside the metal tube 114. For example, the second temperature sensor 101 is attached to a distribution pipe such as an intake pipe of an internal combustion engine or a hydrogen distribution pipe of a fuel cell vehicle. The thermistor element 2 can be arranged in the flow pipe through which the measurement target gas flows to be used for temperature detection of the measurement target gas. The thermistor element 2 changes its electrical characteristics (electric resistance value) depending on the temperature.

  The metal core wire 7 has a tip end connected to the electrode wire of the thermistor element 2 by resistance welding, and a rear end connected to the crimping terminal 11 by resistance welding. Thereby, the rear end side of the metal core wire 7 is connected to a lead wire 12 for connecting an external circuit (for example, an electronic control unit (ECU) of a vehicle) via the crimping terminal 11.

  The second temperature sensor 101 includes an insulating tube 15, a lead wire 12, an auxiliary ring 13, and a joint member 6, similar to the temperature sensor 1. Among the constituent members of the second temperature sensor 101, the same constituent members as those of the temperature sensor 1 of the first embodiment are denoted by the same reference numerals as those of the first embodiment, and description thereof is omitted.

  Although not shown in detail, the second sheath member 108 has the same configuration as the sheath member 8 of the first embodiment in that it includes an outer cylinder, a pair of metal core wires 7, and insulating powder, but has an outer diameter. About a dimension, it is the structure set larger than the sheath member 8 of 1st Embodiment.

  The metal tube 114 is made of a corrosion-resistant metal (for example, a stainless alloy such as SUS316), has a cylindrical shape extending in the axial direction in which the tube front end 131 is closed by deep drawing of the steel plate, and the cylindrical tube rear end side. 132 is configured in an open form. The metal tube 114 accommodates the thermistor element 2 and the distal end side of the second sheath member 108 on the tube distal end side 131, and the tube rear end side 132 abuts against the inner surface of the second step portion 46 of the second attachment member 104. Thus, the axial direction dimension is set.

  The metal tube 114 accommodates the thermistor element 2 and the cement 110 therein, and the cement 110 is filled around the thermistor element 2 to prevent the thermistor element 2 from swinging.

  The second mounting member 104 includes a hexagonal nut portion 51 projecting radially outward, a screw portion 52 having a thread groove, and a rear end side sheath extending from the rear end of the hexagon nut portion 51 toward the rear end side in the axial direction. Part 42. The second mounting member 104 includes a mounting seat 45 formed as a tip surface of the hexagon nut 51, a second joint portion 143 that is joined to the metal tube 114 on the tip side of the mounting seat 45, and the mounting seat 45. And a second vibration reinforcing portion 147 surrounding the periphery of the metal tube 114 in the radial direction.

  In addition, the 2nd attachment member 104 has set the internal diameter dimension of the through-hole which penetrates own inside to an axial direction larger than the attachment member 4 of 1st Embodiment, and the sheath member 8 of 1st Embodiment. It is comprised so that the metal tube 114 with a larger outer diameter dimension can be inserted.

  The second mounting member 104 supports the metal tube 114 by surrounding the outer peripheral surface on the rear end side of the metal tube 114 with at least the tip of the metal tube 114 exposed to the outside.

  The second mounting member 104 is fixed to a sensor mounting position formed on a flow pipe or the like in a state where an annular seal ring 48 made of an elastic material (for example, heat resistant rubber) is disposed on the distal end side of the mounting seat 45. The

  The second attachment member 104 is fixed at the sensor attachment position by screwing the screw portion 52 into a screw groove formed around the sensor attachment position. Further, the mounting position of the second mounting member 104 in the insertion direction at the sensor mounting position is determined by the mounting seat 45 indirectly contacting the sensor mounting position (sensor mounting surface) via the seal ring 48.

  The second joint portion 143 is formed in an annular shape that allows the metal tube 114 to be inserted therein, and is joined to the metal tube 114 so as to surround the circumference of the metal tube 114 in the radial direction. In addition, the second joint portion 143 is set to have a thin thickness dimension (diameter difference between the annular inner diameter dimension and the outer diameter dimension) so that deformation by caulking is possible.

  The rear end side sheath portion 42 is formed in an annular shape, and includes a first step portion 44 located on the front end side and a second step portion 46 having an outer diameter smaller than that of the first step portion 44. It has a shape. Among these, the second step portion 46 is set to have a thin thickness dimension (diameter difference between the annular inner diameter dimension and the outer diameter dimension) so that deformation by caulking is possible.

  Then, after the metal tube 114 is inserted into the second attachment member 104, the second attachment member 104 is subjected to a radially inward caulking operation and an electron beam with respect to each of the second joint portion 143 and the second step portion 46. By performing the welding operation, the metal tube 114 is supported by surrounding the outer peripheral surface of the metal tube 114. That is, the metal tube 114 is fixed to the second attachment member 104 by being joined to the second joint portion 143 and the second step portion 46.

  In addition, the 2nd front end side welding part 162 ranging over the 2nd junction part 143 and the metal tube 114 is formed by welding operation, and the 2nd rear end side welding part 163 straddling the 2nd step part 46 and the metal tube 114 is formed. It is formed.

  In the second temperature sensor 101, at least the tip side portion of the metal tube 114 is exposed to the outside of the second mounting member 104 and the tip in the axial direction from the mounting seat 45 of the second mounting member 104 to the tip of the metal tube 114. The relative position between the second mounting member 104 and the metal tube 114 is set so that the protruding dimension L1 is 45 [mm].

  The second temperature sensor 101 includes the metal tube 114, the second attachment member 104, and the joint member 6 as a metal surrounding member, and the thermistor element 2 is accommodated in a closed space formed by the metal surrounding member. is there. In the second temperature sensor 101, when the atmosphere enters the inside of the joint member 6 from the outside through the gap inside the lead wire 12, the atmosphere is the joint member 6, the metal tube 114, and the second attachment member 104. Since the inside of the metal tube 114 is formed in a closed space, the metal tube 114 enters the inside.

  Therefore, in the second temperature sensor 101, the ventilation from the inside of the lead wire 12 to the inside of the metal tube 114 is ensured, and even when the metal tube 114 that houses the thermistor element 2 is oxidized, the metal tube 114 is provided. As a result, a decrease in oxygen concentration inside the element can be suppressed, and a change in characteristics of the thermistor element 2 can be suppressed.

  The second vibration reinforcing portion 147 is formed in an annular shape through which the metal tube 114 can be inserted, and the metal tube 114 is fixed to the second mounting member 104 so as to surround the periphery of the metal tube 114 in the radial direction. The movement range of the metal tube 114 is limited.

  In addition, the inner diameter dimension in the cross section perpendicular to the axial direction of the second vibration reinforcing portion 147 is set to 3.4 [mm], and the outer diameter dimension (3.3 in the cross section perpendicular to the axial direction of the metal tube 114 is set. Compared to [mm]), it is formed larger by 0.1 [mm].

  The outer diameter dimension of the second vibration reinforcing part 147 in the cross section perpendicular to the axial direction is 6.0 [mm], which is larger than the maximum outer diameter dimension (4.0 [mm]) of the second joint part 143. It is set to be smaller than the maximum outer diameter (15.0 [mm]) of the mounting seat 45.

Further, the second vibration reinforcing portion 147 is configured such that its length in the axial direction (hereinafter also referred to as a reinforcing portion dimension L2) is set to 9.0 [mm].
In the present embodiment, the maximum outer diameter dimension of the mounting seat 45 corresponds to the maximum outer diameter dimension of the hexagon nut 51. Further, the caulking position of the second joint portion 143 is deformed so that the outer diameter dimension becomes 3.8 [mm] by caulking work.

  Then, the external circuit connected to the second temperature sensor 101 via the lead wire 12 takes out the electrical characteristics of the thermistor element 2 that changes according to the temperature of the measurement target gas, and measures based on the extracted electrical characteristics. Detect the temperature of the target gas. In this way, the second temperature sensor 101 is used for temperature detection by being connected to an external circuit.

  As described above, the second temperature sensor 101 has a long tip protrusion dimension L1 as in the temperature sensor 1 of the first embodiment, so that the distance from the sensor mounting position to the temperature detection position is increased. It is possible to detect the temperature of the measurement target gas at the approximate center position of the flow pipe.

  Further, since the second mounting member 104 of the second temperature sensor 101 includes the second vibration reinforcing portion 147 between the mounting seat 45 and the second joint portion 143, the conventional mounting member having no vibration reinforcing portion. In comparison with this, it is possible to ensure a large axial dimension of the region surrounding the metal tube 114. For this reason, the 2nd attachment member 104 can restrict | limit the movable range of the metal tube 114 narrower than before, and can change the vibration characteristic of the metal tube 114.

  The second vibration reinforcing portion 147 has an outer diameter dimension larger than the maximum outer diameter dimension of the second joint portion 143, so that the second vibration reinforcement portion 147 is thicker and stronger than the second joint portion 143. For this reason, the second attachment member 104 having the second vibration reinforcement portion 147 is compared with an attachment member having a configuration in which the joint portion is simply extended in the axial direction without the attachment member having the vibration reinforcement portion or the vibration reinforcement portion. Thus, the overall strength of the mounting member is increased, and the metal tube 114 can be more firmly supported against vibration.

  Thereby, the 2nd temperature sensor 101 can set the resonant frequency of a sensor to a different frequency compared with the temperature sensor provided with the attachment member which does not have a vibration reinforcement part. And the resonant frequency of the 2nd temperature sensor 101 is set to the frequency band different from the frequency band (for example, 0-1 [kHz] band) of the vibration which generate | occur | produces in the flow pipe of this embodiment.

  In addition, since the outer diameter of the second vibration reinforcing portion 147 is smaller than the maximum outer diameter of the mounting seat 45, the second vibration reinforcing portion 147 is disposed when the second temperature sensor 101 is disposed at the sensor mounting position of the flow pipe. 147 does not interfere with the sensor mounting position of the flow pipe. For this reason, the 2nd temperature sensor 101 can be used for the same use as the conventional temperature sensor which is not provided with a vibration reinforcement part.

  Therefore, according to the second temperature sensor 101 of the present embodiment, even when used in an installation environment where the distance from the sensor mounting position of the flow pipe to the temperature detection position is far away, the resonance frequency of the sensor is made the sensor installation environment. Therefore, it is possible to set a frequency band different from the frequency band of vibrations generated by the vibration, and thus it is possible to prevent disconnection due to resonance and breakage of the metal tube 114.

The second temperature sensor 101 is formed such that the inner diameter dimension of the second vibration reinforcing portion 147 is 0.1 [mm] from the outer diameter dimension of the metal tube 114.
For this reason, the 2nd vibration reinforcement part 147 is the state from which the clearance gap between own inner peripheral surface and the outer peripheral surface of the metal tube 114 will be 0.05 [mm] (dimension equivalent to a half of a diameter difference). Thus, the circumference of the metal tube 114 in the radial direction can be surrounded, and the movable range of the portion of the metal tube 114 corresponding to the second vibration reinforcing portion 147 can be limited within a certain range. As described above, by limiting the movable range of the metal tube 114 within a certain range, the vibration characteristics of the metal tube 114 can be improved and the vibration resistance of the temperature sensor can be improved as compared with the case where the movable range is not limited. Can be improved.

  Therefore, the second temperature sensor 101 can set the resonance frequency of the sensor to a different frequency compared to a temperature sensor that does not have the second vibration reinforcing portion 147, and prevents disconnection due to resonance and breakage of the metal tube 114. can do.

  Similarly to the temperature sensor 1 of the first embodiment, the second temperature sensor 101 sets the reinforcing portion dimension L2 of the second vibration reinforcing portion 147 to a value equal to or greater than 20% of the tip protruding dimension L1. The strength against vibration of the sensor can be improved, and the sensor can withstand long-time use.

  Further, similarly to the temperature sensor 1 of the first embodiment, the second temperature sensor 101 sets the reinforcing portion dimension L2 to a value equal to or less than 60% of the tip protrusion dimension L1, so that the second mounting member 104 and the thermistor element are set. It is possible to avoid the distance from 2 from being shortened. The second temperature sensor 101 configured in this way can prevent the temperature change of the thermistor element 2 from being greatly delayed with respect to the temperature change of the measurement target gas, and prevent the responsiveness in temperature detection from being lowered.

  Next, as a third embodiment, the attachment member is not formed with a screw portion and a hex nut portion, and a member having a screw portion and a hex nut portion is provided separately from the attachment member. The temperature sensor 201 will be described.

FIG. 3 is a partially broken sectional view showing the structure of the third temperature sensor 201.
The third temperature sensor 201 includes a sheath member 8 that insulates and holds a pair of metal core wires 7, a cylindrical metal cap 14 that extends in the axial direction with the distal end closed, a third attachment member 204 that supports the sheath member 8, It is configured with. The third temperature sensor 201 includes a nut member 205 having a hexagonal nut portion 251 and a screw portion 252.

  In addition, since the metal core wire 7, the sheath member 8, the joint member 6, the lead wire 12, and the like provided in the third temperature sensor 201 have the same configuration as in the first embodiment, the same configuration members as in the first embodiment. Are denoted by the same reference numerals and description thereof is omitted.

  The third temperature sensor 201 includes the thermistor element 2 as a temperature-sensitive element inside the metal cap 14. For example, the third temperature sensor 201 is attached to an exhaust pipe of an internal combustion engine, and the thermistor element 2 is placed in an exhaust pipe through which exhaust gas flows. It can be used for exhaust gas temperature detection.

  In addition, the 3rd temperature sensor 201 has accommodated the cement 10 similar to 2nd Embodiment inside the metal cap 14 instead of using the earthquake-proof material 17 like 1st Embodiment. Further, since the metal cap 14 is used in a high temperature environment reaching 1000 [° C.], the shape itself is the same as that of the first embodiment, but the material is made of SUS310S which is a heat resistant metal. Yes.

  The third attachment member 204 includes a projecting portion 241 projecting radially outward, a third vibration reinforcing portion 247 positioned on the distal end side of the projecting portion 241 and extending in the axial direction, and on the distal end side of the third vibration reinforcing portion 247. A third joint portion 243 that is positioned and extends in the axial direction, and a rear end-side sheath portion 42 that is positioned on the rear end side of the projecting portion 241 and extends in the axial direction.

  The third mounting member 204 supports the sheath member 8 by surrounding the outer peripheral surface of the sheath member 8 with at least the metal cap 14 and the distal end portion of the sheath member 8 exposed to the outside.

  The projecting portion 241 is formed in an annular shape having a third mounting seat 245 on the distal end side that has a tapered shape with a reduced diameter toward the distal end side. The third mounting seat 245 has a tapered shape corresponding to a tapered portion having a diameter increasing toward the rear end side at a sensor mounting position of an exhaust pipe (not shown).

  That is, when the third mounting member 204 is disposed at the sensor mounting position of the exhaust pipe, the third mounting seat 245 is in direct contact with the tapered portion of the sensor mounting position, so that the exhaust gas leaks out of the exhaust pipe. It is configured to prevent this.

  The third joint portion 243 is formed in an annular shape through which the sheath member 8 can be inserted, and surrounds the periphery of the sheath member 8 in the radial direction and is joined to the sheath member 8. The third joint portion 243 is set to have a thin thickness dimension (diameter difference between the annular inner diameter dimension and the outer diameter dimension) so that deformation by caulking is possible.

  The rear end side sheath portion 42 is formed in an annular shape, and includes a first step portion 44 located on the front end side and a second step portion 46 having an outer diameter smaller than that of the first step portion 44. It has a shape. Among these, the second step portion 46 is set to have a thin thickness dimension (diameter difference between the annular inner diameter dimension and the outer diameter dimension) so that deformation by caulking is possible.

  Then, after the sheath member 8 is inserted into the third attachment member 204, the third attachment member 204 is subjected to a radially inward caulking operation and an electron beam with respect to the third joint portion 243 and the second step portion 46, respectively. By performing the welding operation, the sheath member 8 is supported by surrounding the outer peripheral surface of the sheath member 8. That is, the sheath member 8 is fixed to the third attachment member 204 by being joined to the third joint portion 243 and the second step portion 46.

  In addition, the 3rd front end side welding part 262 ranging over the 3rd junction part 243 and the sheath member 8 (specifically, the outer cylinder of the sheath member 8) is formed by welding operation, and the 2nd step part 46 and the sheath member 8 are formed. In detail, a third rear end side welded portion 263 is formed to straddle (in detail, the outer cylinder of the sheath member 8).

  At this time, at least the metal cap 14 is exposed to the outside of the third mounting member 204, and the tip protrusion dimension L <b> 1 in the axial direction from the rear end position of the third mounting seat 245 of the third mounting member 204 to the tip of the metal cap 14. The relative position between the third attachment member 204 and the sheath member 8 is set such that the distance is 45 [mm].

  The third vibration reinforcing portion 247 is formed in an annular shape through which the sheath member 8 can be inserted, and the sheath member 8 is fixed to the third attachment member 204 so as to surround the periphery of the sheath member 8 in the radial direction. The movement range of the sheath member 8 is limited.

  The inner diameter dimension in the cross section perpendicular to the axial direction of the third vibration reinforcing portion 247 is set to 2.6 [mm], and the outer diameter dimension in the cross section perpendicular to the axial direction of the sheath member 8 (2.5 Compared to [mm]), it is formed larger by 0.1 [mm].

  Moreover, the outer diameter dimension in the cross section perpendicular to the axial direction of the third vibration reinforcing portion 247 is 5.4 [mm], which is larger than the maximum outer diameter dimension (3.4 [mm]) of the third joint portion 243. It is set to be larger than the maximum outer diameter dimension (10.0 [mm]) of the third mounting seat 245.

Further, the third vibration reinforcing portion 247 is configured such that its length in the axial direction (hereinafter also referred to as a reinforcing portion dimension L2) is set to 9.0 [mm].
The maximum outer diameter of the third mounting seat 245 means the diameter of the maximum circumscribed circle that surrounds the largest cross-sectional shape among the cross-sectional shapes of the third mounting seat 245 in the cross section perpendicular to the axial direction. In the embodiment, this corresponds to the diameter dimension of the maximum circumscribed circle in the cross section on the most rear end side of the tapered surface of the third mounting seat 245. In addition, the caulking position of the third joint portion 243 is deformed to 3.2 [mm] in the outer diameter due to the caulking work.

  In addition, a tubular joint member 6 made of a stainless alloy is joined to the third attachment member 204 on the radially outer side of the first step portion 44 of the rear end side sheath portion 42. Specifically, the joint member 6 is connected to the first step portion 44 of the rear end side sheath portion 42 so that the outer peripheral surface of the first step portion 44 of the rear end side sheath portion 42 overlaps the inner peripheral surface of the joint member 6. The joint member 6 and the first step portion 44 are laser welded in the circumferential direction. By performing this laser welding, a joint welding portion 61 is formed across the first step portion 44 of the rear end side sheath portion 42 and the joint member 6.

  The joint member 6 is a state in which the crimping terminal 11, the insulating tube 15, and the auxiliary ring 13 are accommodated therein, and a portion corresponding to the auxiliary ring 13 is circularly crimped or polygonally crimped inward in the radial direction. While maintaining airtightness between the auxiliary ring 13 and the auxiliary ring 13, it is crimped and joined.

  After the third mounting member 204 is arranged so that the nut member 205 is rotatably fitted around the joint member 6 and the third mounting seat 245 contacts the tapered surface of the sensor mounting position, The screw portion 252 of the nut member 205 is screwed into a screw groove formed around the sensor attachment position, so that the nut member 205 is fixed to the sensor attachment position. That is, the third attachment member 204 is fixed in a state of being sandwiched between the nut member 205 and the tapered surface at the sensor attachment position. Further, the third mounting member 204 is arranged in the insertion direction at the sensor mounting position by the third mounting seat 245 coming into contact with the tapered surface of the sensor mounting position.

  Then, the external circuit connected to the third temperature sensor 201 via the lead wire 12 takes out the electrical characteristics of the thermistor element 2 that changes according to the temperature of the measurement object, and exhausts based on the electrical characteristics taken out. Detect the temperature of the gas. In this way, the third temperature sensor 201 is used for temperature detection by being connected to an external circuit.

  As described above, the third temperature sensor 201 has a long tip protrusion dimension L1 as in the case of the temperature sensor 1 of the first embodiment. Therefore, the distance from the sensor mounting position to the temperature detection position is increased. Can be used in the installation environment.

  In addition, since the third attachment member 204 of the third temperature sensor 201 includes the third vibration reinforcement portion 247, the axial direction of the region surrounding the sheath member 8 compared to the conventional attachment member that does not have the vibration reinforcement portion. Large dimensions can be secured. For this reason, the 3rd attachment member 204 can restrict | limit the movable range of the sheath member 8 narrower than before, and can change the vibration characteristic of the sheath member 8. FIG.

  Since the third vibration reinforcing portion 247 has an outer diameter larger than the maximum outer diameter of the third joint 243, the third vibration reinforcing portion 247 is thicker and stronger than the third joint 243. For this reason, the third attachment member 204 having the third vibration reinforcement portion 247 is compared with an attachment member having a configuration in which the joint portion is simply extended in the axial direction without the attachment member having the vibration reinforcement portion or the vibration reinforcement portion. Thus, the overall strength of the attachment member is increased, and the sheath member 8 can be more firmly supported against vibration.

  Therefore, even when the third temperature sensor 201 is used in an installation environment where the distance from the sensor mounting position of the exhaust pipe to the temperature detection position is far away, the resonance frequency of the sensor is a frequency of vibration generated in the sensor installation environment. Since it can be set to a frequency band different from the band, disconnection due to resonance and breakage damage of the sheath member 8 can be prevented.

  Next, as a fourth embodiment, a description will be given of a fourth temperature sensor 301 that includes a metal tube and includes a member having a screw portion and a hexagonal nut portion separately from the attachment member.

FIG. 4 is a partially broken cross-sectional view showing the structure of the fourth temperature sensor 301.
The fourth temperature sensor 301 includes a second sheath member 108 that insulates and holds a pair of metal core wires 7, a cylindrical metal tube 114 that extends in the axial direction with the distal end closed, and a fourth attachment member 304 that supports the metal tube 114. And is configured. The fourth temperature sensor 301 includes a nut member 205 having a hexagon nut portion 251 and a screw portion 252.

Note that among the constituent members of the fourth temperature sensor 301, the same constituent members as those in the first to third embodiments described above are denoted by the same reference numerals and description thereof is omitted.
The fourth temperature sensor 301 includes the thermistor element 2 as a temperature sensing element inside the metal tube 114. For example, the fourth temperature sensor 301 is attached to an exhaust pipe of an internal combustion engine, and the thermistor element 2 is placed in an exhaust pipe through which exhaust gas flows. It can be used for exhaust gas temperature detection.

  The fourth temperature sensor 301 includes the crimping terminal 11, the insulating tube 15, the lead wire 12, the auxiliary ring 13, and the joint member 6. These components have already been described in the above-described embodiment. Therefore, explanation is omitted.

  The fourth attachment member 304 includes a fourth protrusion 341 that protrudes radially outward, a fourth vibration reinforcement 347 that is positioned on the distal end side of the fourth protrusion 341 and extends in the axial direction, and a fourth vibration reinforcement 347. And a rear end side sheath portion 42 that is positioned on the rear end side of the fourth projecting portion 341 and extends in the axial direction.

  The fourth mounting member 304 has a larger inner diameter dimension of the through hole penetrating the inside of the fourth mounting member 304 in the axial direction than the third mounting member 204 of the third embodiment, and the sheath of the third embodiment. The metal tube 114 having a larger outer diameter than the member 8 can be inserted.

  The fourth mounting member 304 supports the metal tube 114 by surrounding the outer peripheral surface on the rear end side of the metal tube 114 with at least the tip of the metal tube 114 exposed to the outside.

  Note that the metal tube 114 in the fourth temperature sensor 301 is used in a high-temperature environment reaching 1000 [° C.], so the shape itself is the same as in the second embodiment, but the material is SUS310S, which is a heat-resistant metal. Etc.

  The 4th protrusion part 341 is formed in the cyclic | annular form which has the 4th mounting seat 345 used as the taper shape of diameter reduction shape toward the front end side at the front end side. The fourth mounting seat 345 has a tapered shape corresponding to a taper portion having a diameter increasing toward the rear end side at a sensor mounting position of an exhaust pipe (not shown).

  That is, when the fourth mounting member 304 is disposed at the sensor mounting position of the exhaust pipe, the exhaust gas leaks out of the exhaust pipe by the fourth mounting seat 345 being in direct contact with the tapered portion of the sensor mounting position. It is configured to prevent this.

  The fourth joint portion 343 is formed in an annular shape that allows the metal tube 114 to be inserted therein, and is joined to the metal tube 114 so as to surround the circumference of the metal tube 114 in the radial direction. Further, the fourth joint portion 343 is set to have a thin thickness dimension (diameter difference dimension between the annular inner diameter dimension and the outer diameter dimension) so that deformation by caulking is possible.

  The rear end side sheath portion 42 is formed in an annular shape, and includes a first step portion 44 located on the front end side and a second step portion 46 having an outer diameter smaller than that of the first step portion 44. It has a shape. Among these, the second step portion 46 is set to have a thin thickness dimension (diameter difference between the annular inner diameter dimension and the outer diameter dimension) so that deformation by caulking is possible.

  Then, after the metal tube 114 is inserted into the fourth attachment member 304, the fourth attachment member 304 is subjected to a radially inward caulking operation and an electron beam with respect to each of the fourth joint portion 343 and the second step portion 46. By performing the welding operation, the metal tube 114 is supported by surrounding the outer peripheral surface of the metal tube 114. That is, the metal tube 114 is fixed to the fourth attachment member 304 by being joined to the fourth joint portion 343 and the second step portion 46.

  In addition, the 4th front end side welding part 362 straddling the 4th junction part 343 and the metal tube 114 is formed by welding operation, and the 4th rear end side welding part 363 straddling the 2nd step part 46 and the metal tube 114 is formed. It is formed.

  At this time, at least the tip side portion of the metal tube 114 is exposed to the outside of the fourth mounting member 304, and in the axial direction from the rear end position of the fourth mounting seat 345 of the fourth mounting member 304 to the tip of the metal tube 114. The relative positions of the fourth mounting member 304 and the metal tube 114 are set so that the tip protrusion dimension L1 is 45 [mm].

  The fourth vibration reinforcing portion 347 is formed in an annular shape that allows the metal tube 114 to be inserted therein, and the metal tube 114 is fixed to the fourth mounting member 304 so as to surround the radial periphery of the metal tube 114. The movement range of the metal tube 114 is limited.

  The inner diameter dimension in the cross section perpendicular to the axial direction of the fourth vibration reinforcing portion 347 is set to 3.4 [mm], and the outer diameter dimension (3.3 in the cross section perpendicular to the axial direction of the metal tube 114 is set. Compared to [mm]), it is formed larger by 0.1 [mm].

  Further, the outer diameter dimension in the cross section perpendicular to the axial direction of the fourth vibration reinforcing portion 347 is 6.0 [mm], which is larger than the maximum outer diameter dimension (4.0 [mm]) of the fourth joint portion 343. It is set to be smaller than the maximum outer diameter dimension (10.0 [mm]) of the fourth mounting seat 345.

Further, the fourth vibration reinforcing portion 347 is configured such that its length in the axial direction (hereinafter also referred to as a reinforcing portion dimension L2) is set to 9.0 [mm].
The maximum outer diameter dimension of the fourth mounting seat 345 means the diameter dimension of the maximum circumscribed circle surrounding the largest cross-sectional shape among the cross-sectional shapes of the fourth mounting seat 345 in the cross section perpendicular to the axial direction. In the embodiment, this corresponds to the diameter dimension of the maximum circumscribed circle in the cross section on the most rear end side among the tapered surfaces of the fourth mounting seat 345. Further, the caulking position of the fourth joint portion 343 is deformed by the caulking work so that the outer diameter dimension becomes 3.8 [mm].

  In addition, a cylindrical joint member 6 made of a stainless alloy is joined to the outer side in the radial direction of the first step portion 44 of the rear end side sheath portion 42 in the fourth attachment member 304. About the joining aspect of the 4th attachment member 304 and the coupling member 6, since it is the same as that of 3rd Embodiment, description is abbreviate | omitted.

  After the fourth mounting member 304 is arranged so that the nut member 205 is rotatably fitted around the joint member 6 and the fourth mounting seat 345 contacts the tapered surface of the sensor mounting position, The screw portion 252 of the nut member 205 is screwed into a screw groove formed around the sensor attachment position, so that the nut member 205 is fixed to the sensor attachment position. That is, the fourth attachment member 304 is fixed in a state of being sandwiched between the nut member 205 and the tapered surface at the sensor attachment position. Further, the fourth mounting member 304 is arranged in the insertion direction at the sensor mounting position by the fourth mounting seat 345 coming into contact with the tapered surface of the sensor mounting position.

  Then, the external circuit connected to the fourth temperature sensor 301 via the lead wire 12 takes out the electrical characteristics of the thermistor element 2 that changes according to the temperature of the object to be measured, and exhausts based on the electrical characteristics taken out. Detect the temperature of the gas. In this way, the fourth temperature sensor 301 is used for temperature detection by being connected to the external circuit.

  As described above, the fourth temperature sensor 301 has a long tip protrusion dimension L1 as in the temperature sensor 1 of the first embodiment, so that the distance from the sensor mounting position to the temperature detection position is increased. Can be used in the installation environment.

  Further, since the fourth mounting member 304 of the fourth temperature sensor 301 includes the fourth vibration reinforcing portion 347, the axial direction of the region surrounding the metal tube 114 compared to the conventional mounting member having no vibration reinforcing portion. Large dimensions can be secured. For this reason, the 4th attachment member 304 can restrict | limit the movable range of the metal tube 114 narrower compared with the past, and can change the vibration characteristic of the metal tube 114. FIG.

  The fourth vibration reinforcing portion 347 has an outer diameter dimension larger than the maximum outer diameter dimension of the fourth joint portion 343, so that the fourth vibration reinforcing portion 347 is thicker and stronger than the fourth joint portion 343. For this reason, the fourth attachment member 304 having the fourth vibration reinforcement portion 347 is compared with an attachment member having a configuration in which the joint portion is simply extended in the axial direction without the attachment member having the vibration reinforcement portion or the vibration reinforcement portion. Thus, the overall strength of the mounting member is increased, and the metal tube 114 can be more firmly supported against vibration.

  Therefore, even when the fourth temperature sensor 301 is used in an installation environment where the distance from the sensor mounting position of the exhaust pipe to the temperature detection position is far away, the resonance frequency of the sensor is the frequency of vibration generated in the sensor installation environment. Since it can be set to a frequency band different from the band, it is possible to prevent disconnection due to resonance and breakage of the metal tube 114.

As mentioned above, although embodiment of this invention was described, this invention is not limited to the said embodiment, It can take a various aspect.
For example, the diameter difference between the inner diameter dimension of the vibration reinforcing portion and the outer diameter dimension of the sheath member (or metal tube) is not limited to 0.1 [mm], and is set to at least 0.3 [mm] or less. Thus, the movable range of the sheath member (or metal tube) can be limited, and the resonance frequency of the temperature sensor can be changed.

  In addition, the diameter difference between the inner diameter dimension of the vibration reinforcement portion and the outer diameter dimension of the sheath member (or metal tube) is set to 0 [mm], and the inner surface of the vibration reinforcement portion contacts the outer surface of the sheath member (or metal tube). By contacting, the vibration reinforcing portion can limit the movement of the sheath member (or metal tube) and can support the sheath member (or metal tube).

  Next, the tip protrusion dimension L1 is not limited to 45 [mm], and if the tip protrusion dimension L1 is set according to the installation environment (in other words, the distance from the sensor mounting position to the temperature detection position). Good. By applying the present invention to a temperature sensor used in a setting environment in which the distance from the sensor mounting position to the temperature detection position is 20 [mm] or more, a disconnection due to resonance or a sheath member (or It is possible to prevent breakage of the metal tube).

  Furthermore, the aspect of the caulking work can adopt polygonal caulking such as hexagonal caulking, octagonal caulking, round caulking, etc., and an aspect in which two members to be joined can be integrally joined. I just need it.

  In addition, the mounting member having a tapered mounting seat is not limited to one in which the taper angle of the mounting seat is the same as the taper angle of the tapered portion at the sensor mounting position.

  Here, as shown in FIG. 5, the taper angle (opening angle) of the third mounting seat 245 of the third mounting member 204 is defined as α, and the taper angle (opening) of the taper portion 83 at the sensor mounting position 81 of the exhaust pipe 85 is defined. The angle is defined as β. In FIG. 5, for convenience, not only the entire temperature sensor but the third attachment member 204 is shown, and the sensor attachment position 81 of the exhaust pipe 85 is shown as a simplified cross section.

  For example, when the relationship of “α <β” is satisfied, the third mounting member 204 is in contact with the tapered portion 83 of the sensor mounting position 81 at the distal end portion of the tapered surface of the third mounting seat 245. Become. And since this contact | abutting part becomes small in the diameter dimension in a cross section perpendicular | vertical to an axial direction, it needs to set the outer diameter dimension of a vibration reinforcement part small. For this reason, it becomes difficult to ensure a large outer diameter dimension of the vibration reinforcing portion, and it becomes difficult to sufficiently increase the strength of the vibration reinforcing portion.

  On the other hand, when the relationship of “α> β” is satisfied, the third attachment member 204 is located on the rear end side portion of the tapered surface of the third attachment seat 245 with the tapered portion 83 of the sensor attachment position 81. It will abut. And since this contact | abutting part becomes large in the diameter dimension in the cross section perpendicular | vertical to an axial direction, it can ensure the outer diameter dimension of a vibration reinforcement part large.

  Therefore, when the taper angle α of the mounting seat is set to an angle different from the taper angle β of the taper portion at the sensor mounting position, the mounting member is configured so as to satisfy the relationship of “α> β”. The strength of the reinforcing portion can be sufficiently increased, and the resonance frequency of the temperature sensor can be changed.

  Further, the constituent members of the temperature sensor are not limited to those in which the joint portion and the vibration reinforcing portion are integrally formed with the mounting member. After the joint portion and the vibration reinforcing portion are integrally formed, the member is attached to the mounting member. What is joined (for example, welding, brazing, etc.) to the side on which the mounting seat is formed may be used. Alternatively, a joint portion, a vibration reinforcing portion, and an attachment member can be individually formed, and then those members can be appropriately joined (for example, welding or brazing).

  Furthermore, the vibration reinforcing part is not limited to a single-stage structure, and has a multi-stage structure of two or more stages within a range larger than the maximum outer diameter dimension of the joint and smaller than the maximum outer diameter dimension of the mounting seat. May be.

It is a fragmentary sectional view which shows the structure of a temperature sensor. It is a fragmentary sectional view which shows the structure of a 2nd temperature sensor. It is a fragmentary sectional view which shows the structure of a 3rd temperature sensor. It is a fragmentary sectional view which shows the structure of a 4th temperature sensor. It is explanatory drawing which shows taper angle (alpha) of the attachment seat in an attachment member, and taper angle (beta) of the taper part in a sensor attachment position.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Temperature sensor, 2 ... Thermistor element, 4 ... Mounting member, 7 ... Metal core wire, 8 ... Sheath member, 11 ... Clamping terminal, 12 ... Lead wire, 14 ... Metal cap, 43 ... Joint part, 45 ... Mounting seat , 47 ... Vibration reinforcing part, 48 ... Seal ring, 101 ... Second temperature sensor, 104 ... Second mounting member, 108 ... Second sheath member, 114 ... Metal tube, 143 ... Second joint, 147 ... Second vibration Reinforcing part 201 ... third temperature sensor 204 ... third attachment member 243 ... third joint part 245 ... third attachment seat 247 ... third vibration reinforcement part 301 ... fourth temperature sensor 304 ... fourth Mounting member, 343... Fourth joint, 345... Fourth mounting seat, 347.

Claims (8)

A sheath member insulatively holding a metal core wire to which a temperature sensitive element whose electrical characteristics change depending on temperature is connected to the front end side, and a lead wire for external circuit connection is connected to the rear end side;
A metal cap that has a cylindrical shape extending in the axial direction, the inner circumference of the rear end side being joined over the circumferential direction of the outer circumference of the distal end side of the sheath member in a form in which the temperature sensing element is housed inside
The sheath member is supported by surrounding the outer peripheral surface of the sheath member with the metal cap and the distal end portion of the sheath member exposed to the outside, and directly or indirectly through another member with respect to the sensor mounting position. A mounting member having a mounting seat in contact with
A temperature sensor comprising:
The tip protruding dimension in the axial direction from the mounting seat of the mounting member to the tip of the metal cap is 20 [mm] or more,
A joint portion that has an outer diameter smaller than the maximum outer diameter dimension of the mounting seat, and surrounds the periphery of the sheath member in the radial direction on the tip side of the mounting seat, and is joined to the sheath member;
The outer diameter is larger than the maximum outer diameter of the joint and smaller than the maximum outer diameter of the attachment seat, and is disposed between the attachment seat and the joint so as to surround the periphery of the sheath member in the radial direction. A vibration reinforcing portion to be provided,
Temperature sensor. The vibration reinforcing portion has a length dimension in the axial direction that is not less than a value equivalent to 20% of the tip protrusion dimension and not more than a value equivalent to 60%.
The temperature sensor according to claim 1. The difference in diameter between the outer diameter of the sheath member corresponding to the vibration reinforcing portion and the inner diameter of the vibration reinforcing portion is 0 to 0.3 [mm].
The temperature sensor according to claim 1, wherein: The joint and the vibration reinforcement are integrally formed with the mounting member;
The temperature sensor according to any one of claims 1 to 3, wherein: A cylindrical metal tube extending in the axial direction;
A temperature sensitive element housed in the tip side of the metal tube, the electrical characteristics of which change with temperature, and
Mounting that supports the metal tube by surrounding the outer peripheral surface of the metal tube in a state in which the tip side portion of the metal tube is exposed to the outside, and that directly contacts the sensor mounting position directly or through another member A mounting member having a seat;
A temperature sensor comprising:
The tip protruding dimension in the axial direction from the mounting seat of the mounting member to the tip of the metal tube is 20 [mm] or more,
A joint portion that has an outer diameter smaller than the maximum outer diameter dimension of the mounting seat, and that surrounds the periphery of the metal tube in the radial direction on the tip side of the mounting seat and is joined to the metal tube;
The outer diameter is larger than the maximum outer diameter of the joint and smaller than the maximum outer diameter of the mounting seat, and is disposed between the mounting seat and the joint so as to surround the radial circumference of the metal tube. A vibration reinforcing portion to be provided,
Temperature sensor. The vibration reinforcing portion has a length dimension in the axial direction that is not less than a value equivalent to 20% of the tip protrusion dimension and not more than a value equivalent to 60%.
The temperature sensor according to claim 5. The difference in diameter between the outer diameter of the portion corresponding to the vibration reinforcing portion and the inner diameter of the vibration reinforcing portion of the metal tube is 0 to 0.3 [mm].
The temperature sensor according to claim 5 or 6, characterized by the above. The joint and the vibration reinforcement are integrally formed with the mounting member;
The temperature sensor according to claim 5, wherein:

Images