JPS6242341Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a temperature sensor for an intake pipe, and more particularly to an intake air temperature sensor device for an automobile in which an element whose electrical characteristics change depending on temperature is a thermistor.

In the conventional intake air temperature sensor, for example, as shown in FIG. 1, a thermistor 2 is housed in a metal case 1 of a closed-end tube, and the output terminal of the thermistor 2 and the external terminal 4 of an external plug 3 are connected with a normal lead wire 5. Connect the wires,
In order to fix and protect the thermistor 2 and lead wire 5, it was filled with silicone 6 or the like.

According to such a conventional sensor, the thermistor 2
In this case, the intake air temperature was measured through the metal case 1, and the response was extremely poor. In addition, the seat temperature of the sensor mounting part is transmitted to the case 1, and external heat is transmitted to the thermistor 2 via the lead wire 5, and the measured value has a large error from the true value. There was a problem.

This invention was devised in view of the above problems, and aims to solve the above problems by providing an intake air temperature sensor device that can improve the responsiveness of temperature detection and reduce measurement errors. That is.

Hereinafter, the intake air temperature sensor device according to the invention will be explained based on an embodiment illustrating the device.

In FIG. 2, the intake air temperature sensor device includes a substantially cylindrical thermistor storage case 7, an ambient temperature measurement space 8 provided near the lower opening end of the case 7, and a thermistor 9 held above the space 8. The main structure includes a thermistor plug 10 formed by the above, and an external plug 10' fitted into the upper open end of the case 7. The storage case 7 is made of resin with high heat insulation, and has a surface around one end.
A device mounting flange 11 is formed at the other end,
A plurality of ventilation through holes 12 are formed at positions corresponding to the space 8 to promote appropriate convection within the space 8. Further, a socket seat 13 into which the thermistor plug 10 is fitted and fixed is formed above the space 8 within the tube. The thermistor plug 10 is made of the same resin as the storage case 7, and is fixed in the case 7 by a fitting protrusion 14 that can fit into the socket seat 13. In this fixed state, the plug 10
An output terminal 15 of the thermistor 9 is locked in a member of the plug 10 so that the thermistor 9 can be held while protruding into the measurement space 8. The external plug 10' is fitted and fixed into the case 7 by a fitting protrusion 14' that can be fitted into the upper open end of the storage case 7, and has a connecting terminal 15' connected to the external lead wire 16 inside the member. It is locked. The respective output terminals 15 and connection terminals 15' of the pair of plugs 10, 10' as described above are connected by conductive wires 17 with high heat insulation, and there is an insulating wire between the two plugs 10, 10'. Gel-like soft resin with low thermal conductivity 1
8 is filled. The conducting wire 17 prevents heat conduction between the thermistor 9 and the external lead wire 16 while providing electrical continuity therebetween. This conductor 17
For example, a thin metal wire processed into a coil shape or a conductive resin processed into a string shape can be used. The soft resin 18 is for protecting the conducting wire 17 from damage due to vibrations, shocks, etc., and various materials such as silicone plastic can be used as long as it has insulating properties and low thermal conductivity.

The intake air temperature sensor device as described above is attached to the intake pipe 19 in the following manner (see FIG. 3).

A mounting hole 20 is bored in the intake pipe 19, and the sensor device is inserted through the mounting hole 20, and the gasket 2
1 to the intake pipe 19. A bolt insertion hole 22 is formed in the flange 11, and the sensor device is fixed to the intake pipe 19 by inserting a fixing bolt 23 into the bolt insertion hole 22 and then screwing it into the intake pipe 19. In this way, the intake air temperature sensor device is extremely simple.
The negative pressure within the intake pipe 19 is also reliably maintained by the gasket 21.

4a and 4b show another example of mounting the intake air temperature sensor device.

In the sensor device, a mounting attachment 24 having a pair of bolt insertion holes 22 is inserted from below into the storage case 7, and an adhesive fastener 24 filled with trapezoidal adhesive is formed at the abutting portion of the mounting flange 11.
5.

In this state, the sensor device
1 and the intake pipe 19 by the fixing bolt 23.
It is screwed on.

5a and 5b show still another example of mounting the sensor device.

Mounting attachment 24' according to this installation example
is the intake pipe 19 relative to the attachment 24.
The mounting flange 11 of the sensor device inserted into the mounting hole 20 of the intake pipe 19 via the gasket 21 is fixed by pressure from above via the packing 26 made of heat-resistant rubber. It is something to do.

Since the storage case 7 for the sensor device mounted in the above manner is made of resin, it blocks the inherent heat of the surrounding members, and the conducting wire 17 also prevents heat conduction from the external lead wire 16. ing. Therefore, the thermistor 9 is thermally independent, and the measurement space 8 provided with the ventilation through hole 12 allows
It is protected from high-speed intake air flow while promoting proper convection.

One embodiment of the intake air temperature sensor device according to this invention is as described above, and has the following excellent effects.

The thermistor is made thermally independent and exposed to the inside of the intake pipe through the measurement space, and the thermistor immediately responds to the detected temperature, resulting in significant improvements in responsiveness and measurement accuracy. Also,
When installing it, it has excellent assemblability, as it can be installed easily and firmly by using simple attachments.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a conventional intake air temperature sensor, FIG. 2 is a sectional view showing an intake air temperature sensor device according to this invention, FIG. 3 is a sectional view showing an example of how the device is installed, and FIG. Figures a and b are a plan view and a side view showing another example of how the device is installed, and Figures 5a and b are a plan view and a side view showing still another example of how the device is installed. 1...Metal case, 2...Thermistor, 3...
External plug, 4... External terminal, 5... Lead wire,
6... Silicone, 7... Storage case, 8... Measurement space, 9... Thermistor, 10... Thermistor plug, 10'... External plug, 11... Mounting flange, 12... Ventilation through hole, 13 ...Socket seat, 14...Mating protrusion, 15...Output terminal, 1
5'... Connection terminal, 16... External lead wire, 17
... Conductor wire, 18 ... Soft resin, 19 ... Intake pipe,
20...Mounting hole, 21...Gasket, 22...
Insertion hole, 23... Fixing bolt, 24, 24'...
Attachment, 25...adhesive fastener, 26...packing.

Claims (1)

[Scope of utility model registration request] In an intake air temperature sensor installed in the intake pipe of an internal combustion engine such as an automobile, a thermistor storage case that can be installed in a substantially cylindrical intake pipe is formed from resin with high thermal insulation. A measurement space and a plurality of ventilation through holes opened in the circumferential direction thereof are provided, a thermistor plug is provided adjacent to the measurement space in the middle part of the thermistor storage case, and the thermistor is supported by the thermistor plug. The thermistor is projected into the ambient temperature measurement space, and an external plug is fitted into the other open end, which has an external terminal connected to an external lead wire, and thermally insulates the output terminal of the thermistor and the external terminal. In addition to connecting with a conductor with a high temperature, both plugs are filled with an insulating gel-like soft resin with low thermal conductivity to thermally isolate the thermistor from the inherent heat of surrounding components. sensor device.