JP2003214903A - Rotation detecting sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotation detecting sensor obtaining stable detection accuracy without increasing production cost. <P>SOLUTION: This rotation detecting sensor 31 is equipped with a cylindrical sensor case 33 with bottom; a sensor housing 37 to which a rotation detecting means 35 is assembled; and a sensor cover 39 sealing the sensor case 33 in which the sensor housing 37 is housed in the specified position. The sensor cover 39 is welded to an insertion opening part 50 of the sensor case 33 while the sensor housing 37 is pressed and energized in the insertion direction with a pressing projection 39b formed on the inner surface of the sensor cover 39. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotation detection sensor such as a rotation detection semiconductor pickup sensor for detecting the rotation speed of a gear used in an automobile engine or a mission.

[0002]

2. Description of the Related Art As a rotation detecting sensor for detecting the number of rotations of a gear used for an automobile engine or a mission,
A semiconductor pickup sensor for rotation detection shown in FIGS. 5 to 7 is known. The rotation detection sensor 10 shown in FIG.
Is disclosed in, for example, Japanese Patent Application Laid-Open No. 2001-264350, and the rotation detecting means 3 is assembled through the pair of terminals 9 and 9, and the rotation detecting means 3 and the pair of terminals. A sensor case 1 formed in a cylindrical shape with a bottom and made of synthetic resin so as to accommodate and cover the parts of the 9, 9 excluding the base end side, and the sensor case 1 so as to be exposed outside the upper end of the sensor body 5. A pair of lead wires 1 in which each core wire 14a is connected to each base end of the formed pair of terminals 9, 9.
4, 14 and a flexible waterproof cap 7 penetrating each lead wire 14 and fitted on the upper end of the sensor body 5.

The rotation detecting sensor 10 shown in FIG.
As shown in FIG. 3, the tip of the rotation detecting means 3 housed on the bottom portion 1b side of the sensor case 1 is fixed by fixing the mounting flange portion 1a protruding on the outer periphery of the sensor case 1 to the gear case 21. The parts are installed in a state of being separated from the outer periphery of the gear 23 by a predetermined distance.

Rotation detecting means 3 in the sensor case 1
Is a structure in which a rotation detecting element such as a Hall IC known as a semiconductor type rotation detecting element is combined with a capacitor or the like, and a magnet formed by a magnet and a gear 23 built in the Hall IC at the tip portion. The rotation of the gear 23, which is the object to be detected, is detected from the change in the magnetic flux of the circuit.

As shown in FIG. 6, the sensor main body 5 has a pair of terminals 9 to which the rotation detecting means 3 is connected at the tip,
9 and a housing 12 made of synthetic resin for supporting the intermediate portions of these terminals 9, 9. A pair of terminals 9,
9 is integrated with the housing 12 by insert molding. Further, the hood portion 12a of the housing 12
The core wires 14a of the pair of lead wires 14, 14 connected to the rotation measuring device are connected to the base ends of the pair of lead terminals 9, 9 projecting from the core terminals 14a by soldering or the like.

As shown in FIG. 6, when the sensor main body 5 is inserted into the peripheral edge of the insertion opening 17 of the sensor case 1, it abuts against a butting surface 12b formed on the outer periphery of the lower surface of the housing 12. A protrusion 18 for welding is formed. Therefore, in the sensor body 5, as shown in FIG. 7, the abutting surface 12b of the housing 12 is brought into contact with the welding projection 18 of the sensor case 1 and welded by a welding method such as ultrasonic welding or orbital vibration welding. As a result, the sensor case 1 is fixed.

In the waterproof cap 7, after the lead wire 14 is hermetically inserted into each electric wire through hole 7b having a waterproof structure,
By fitting the fitting groove 7a formed on the lower surface into the hood portion 12a of the housing 12, the base end of each terminal 9 protruding to the upper end of the sensor body 5 and the core wire 14a of each lead wire 14 are electrically connected. Maintains continuity and waterproof reliability.

[0008]

By the way, in the conventional rotation detecting sensor 10 as described above, the position of the bottom portion 1b of the sensor case 1 in the gear case 21 is such that the mounting flange portion 1a contacts the outer surface of the gear case 21. By bringing them into contact with each other, they are positioned at proper positions.

However, due to the variation in the amount of fusion between the abutting surface 12b fixed by welding and the protrusion 18 for welding, the gap S between the bottom 1b of the sensor case 1 and the tip of the rotation detecting means 3 varies. The variation in the gap S causes variation in the separation distance H between the tip of the rotation detecting means 3 in the rotation detecting sensor 10 attached to the gear case 21 and the gear 23, resulting in a decrease in detection accuracy.

Therefore, the abutting surface 12b when the housing 12 of the sensor body 5 is fixed to the sensor case 1 by welding.
In order to prevent variations in the amount of fusion between the welding protrusions 18 and the welding protrusions 18, the abutting surface 12b and the welding protrusions 18
It is necessary to improve the molding accuracy of
There was a problem that the manufacturing cost increased.

Further, the rotation detecting sensor 10 as described above.
When assembling the sensor body 5 into the sensor case 1,
The rotation detecting means 3 which is previously filled with an adhesive and housed in the sensor case 1 is fixed. Therefore, in order to prevent the adhesive agent filled in the sensor case 1 from leaking out during the welding work, the welding work must be performed in a posture in which the sensor case 1 is installed below (the posture shown in FIG. 7). I won't.

Therefore, the sensor body 5 has the lead wire 1
Welding work for the sensor case 1 must be performed in a state where the lead wires 4, 14 are drawn out upward, and the lead wires 1
There is also a problem in that the welding work is troublesome and the productivity is lowered because the wires 4 and 14 interfere with the lowering operation of the welding jig such as the welding horn. Therefore, an object of the present invention is to solve the above problems, and to provide a rotation detection sensor that can obtain stable detection accuracy without increasing the manufacturing cost.

[0013]

The above object of the present invention is to provide a sensor case having a bottomed cylindrical shape, a sensor housing in which rotation detecting means is assembled, and a sensor case in which the sensor housing is housed at a predetermined position. And a sensor cover that seals the sensor cover, wherein the sensor cover is configured to press the sensor housing in the insertion direction by a pressing protrusion that is provided on the inner surface of the sensor cover, This is achieved by a rotation detection sensor characterized by being welded to the insertion opening of the case.

According to the above construction, after the sensor housing is housed at a predetermined position in the sensor case, the sensor cover presses and urges the sensor housing in the inserting direction, and the sensor cover opens the insertion opening of the sensor case. Is welded to seal the inside of the sensor case. Therefore, the sensor housing itself, which is positioned at a predetermined position by abutting a predetermined portion in the sensor case, does not have a portion welded to the sensor case, and the positioning position with respect to the sensor case does not vary.

Further, since the sensor housing housed at a predetermined position in the sensor case is held in a state of being pressed and biased in the insertion direction by the pressing protrusion of the sensor cover, there is no rattling. Therefore, the gap between the bottom of the sensor case and the tip of the rotation detecting means assembled to the sensor housing is always maintained at an appropriate value regardless of the variation in the melting amount between the sensor case and the sensor cover, so that stable detection can be performed. Accuracy can be obtained.

Preferably, a case side terminal to which a lead wire is connected is insert-molded in the sensor case,
In addition, the sensor housing is provided with a sensor-side terminal that is connected to the rotation detecting means and is connectable to the case-side terminal.

In this case, when the sensor housing is housed in the sensor case, the sensor-side terminal mounted on the sensor housing is connected to the case-side terminal mounted on the sensor case so that the sensor housing is mounted on the sensor case side. The lead wire is connected to the rotation detecting means.

Therefore, when the sensor cover is put on the sensor case which has been housed in the sensor housing and the sensor cover is welded to the sensor case, the leads connected to the rotation detecting means housed in the sensor case. Since the wire is led out from the sensor case and is not led out above the sensor cover, it does not interfere with the lowering operation of the welding jig such as the welding horn.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION A rotation detecting sensor according to an embodiment of the present invention will be described in detail below with reference to the accompanying drawings.
The rotation detection sensor 31 according to the present embodiment is a rotation detection semiconductor pickup sensor that detects the number of rotations of a gear used in an engine or a mission of an automobile, like the rotation detection sensor 10 shown in FIG.

As shown in FIG. 1, the rotation detecting sensor 31 of the present embodiment has a sensor housing 33 in which a bottomed cylindrical sensor case 33 and rotation detecting means 35 are assembled.
And a sensor cover 39 that seals the inside of the sensor case 33 in which the sensor housing 37 is housed at a predetermined position.

The sensor case 33 has a bottomed cylindrical portion 41 for accommodating the sensor housing 37 and the bottomed cylindrical portion 41.
The mounting flange portion 42 formed in a flange shape at the opening edge of the insertion opening portion 50 is integrally formed of synthetic resin. By fixing the mounting flange portion 42 with the lower surface 42a in contact with the outer surface of the gear case 21 or the like, as shown in FIG. 4, the protruding length L of the bottomed tubular portion 41 into the gear case is L. The bottom portion 41a of the bottomed tubular portion 41 is installed in a state of being separated from the outer periphery of the gear (not shown) whose rotation is to be detected by a certain distance.

A case-side terminal 47, to which a lead wire 45 is connected, is insert-molded on the bulging portion (right side in FIG. 1) 42b of the mounting flange portion 42. These lead wires 45 and the case side terminals 47 are to be connected to the pair of sensor side terminals 57, 57 of the rotation detecting means 35 assembled in the sensor housing 37, and are provided as a pair at intervals in the circumferential direction. There is.

The lead wire 45 is inserted in a rubber bush 49 for ensuring waterproofness, and the case side terminal 4 is inserted.
After being connected to No. 7, it is insert-molded together with the rubber bush 49 on the mounting flange portion 42. Therefore, the lead wire 45 is led out from the mounting flange portion 42 of the sensor case 33 in the radial direction.

The case-side terminal 47 is a bus bar formed by press-molding a metal plate and has an electric wire connecting portion 47b at one end to which the core wire 45a of the lead wire 45 is electrically connected by welding or soldering. The sensor side terminal 57 is provided at the end.
The terminal connection portion 47a is electrically hung.

An opening 50 for inserting the sensor case 33.
Includes a positioning step portion 52 for positioning the sensor housing 37 inserted in the bottomed tubular portion 41 at a predetermined position, and a welding step portion 53 located above the positioning step portion 52. Is provided.

The sensor housing 37 has a lower surface abutting against the positioning step 52 and a case fitting portion 55a fitted into the insertion opening 50, and a housing for supporting the assembled rotation detecting means 35. The main body 55b and the main body 55b are integrally formed. The case fitting portion 55a and the housing main body 55b are provided with the sensor side terminal 5 made of a metal plate and connected to the rotation detecting means 35.
7 is insert-molded, and the end portion of the sensor-side terminal 57 projects outward in the radial direction from the outer surface of the case fitting portion 55a.

At the end of the sensor side terminal 57 protruding from the case fitting portion 55a, the sensor housing 37 is inserted into the sensor case 33 as shown in FIG. 3, and the case fitting portion 55a is positioned at the positioning step. When seated on the portion 52, the through hole formed is fitted into the terminal connecting portion 47 a of the case-side terminal 47. In this state, the sensor side terminal 5
The end of 7 is electrically connected to the terminal connecting portion 47 a of the case-side terminal 47 by soldering or the like.

The rotation detecting means 35 has, for example, a Hall IC 35a known as a semiconductor type rotation detecting element in combination with a capacitor 35b and the like, and a magnet built in the Hall IC 35a at the tip and a gear to be detected. The rotation of the gear, which is the object to be detected, is detected from the change in the magnetic flux of the magnetic circuit formed by (not shown).

Then, the rotation detecting sensor 31 of the present embodiment.
Then, as shown in FIG. 3, the sensor housing 37 is inserted in a state where the bottomed tubular portion 41 of the sensor case 33 is filled with the adhesive 61, and the sensor side terminal 57 is attached by soldering or the like.
And the case side terminal 47 are electrically connected to each other, and then the sensor cover 3 is inserted into the insertion opening 50 of the sensor case 33.
9 is fitted.

As shown in FIG. 3, the sensor cover 39 covers the insertion opening 50 from above the sensor housing 37 housed in the sensor case 33, and water drops, dust, etc., into the sensor case 33. To prevent the intrusion of. As shown in FIG. 2, the sensor cover 39 is a synthetic resin integrally molded product, and has a pressing projection 39b and a welding rib 39c on the inner surface of a top plate 39a that covers the insertion opening 50.
And are projected.

The pressing protrusion 39b has a tip end which presses and biases the upper surface of the case fitting portion 55a and presses the sensor housing 37 against the positioning step portion 52 so as to position the center portion of the top plate 39a. It is provided at a near position so as to project in a substantially U-shape. Further, the rib 3 for welding
9c is provided so as to project in an annular shape along the peripheral edge of the top plate 39a so that when the sensor cover 39 is covered from above the sensor housing 37, the tip portion contacts the welding step portion 53. .

The pressing protrusions 39b and the welding ribs 39c are set to such heights that the tips of the pressing protrusions 39b abut the upper surface of the case fitting portion 55a and the welding step portion 53 at substantially the same time. The tip portion of the pressing protrusion 39b is also appropriately melted by ultrasonic vibration when the welding rib 39c of the sensor cover 39 is welded, so that it can be set slightly higher.

The rotation detecting sensor 31 of this embodiment described above.
In the above, the sensor housing 37 is attached to the sensor case 33.
And insert the case fitting portion 55a into the positioning step portion 5
The sensor cover 39 is put on the sensor housing 37 from above the sensor housing 39 after the sensor cover 39 is housed in a predetermined position by being seated on the seat 2.
Then, as shown in FIG. 4, the pressing cover 39b presses the sensor housing 37 in the inserting direction to weld the welding ribs 39c to the welding step portion 53, whereby the sensor cover 39 is attached to the sensor case. It is integrated in a state of covering the insertion opening 50 of 33 and seals the inside of the sensor case 33.

Therefore, the case fitting portion 55 is attached to the positioning step portion 52 which is a predetermined portion in the sensor case 33.
The sensor housing 37 itself, which is brought into contact with a and is positioned at a predetermined position, does not have a portion welded to the sensor case 33, and thus the positioning position with respect to the sensor case 33 does not vary.

The sensor housing 37 housed at a predetermined position in the sensor case 33 has a sensor cover 39.
Since it is held in a state of being pressed and urged in the inserting direction by the pressing protrusion 39b, there is no rattling.
The tip portion of the pressing protrusion 39b is attached to the sensor cover 39.
By ultrasonic vibration when welding the welding rib 39c of
The ribs 39c are appropriately melted according to the melting amount of the ribs 39c, but the positioning accuracy of the sensor housing 37 is not affected.

That is, the gap between the bottom portion 41a of the bottomed tubular portion 41 of the sensor case 33 and the tip of the rotation detecting means 35 assembled to the sensor housing 37 is the welding step portion 53 and the welding rib 39c. Irrespective of the variation in the mutual melting amount, it is determined only by the contact state between the positioning step portion 52 and the case fitting portion 55a,
It is always maintained at a proper value. Therefore, the rotation detection sensor 31 of the present embodiment can obtain stable detection accuracy. Therefore, the rotation detection sensor 31 of the present embodiment does not require a measure to increase the molding accuracy of the welding step portion 53 and the welding rib 39c and the accuracy of the welding jig and tool, which causes a cost increase, and the manufacturing cost. Can suppress the rise of.

Further, in the rotation detecting sensor 31 of the present embodiment, when the sensor housing 37 is housed in the sensor case 33, the sensor side terminal 57 provided in the sensor housing 37 is provided in the sensor case 33. By electrically connecting to the terminal connecting portion 47a of the terminal 47, the lead wire 45 mounted on the sensor case 33 side
Is connected to the rotation detecting means 35.

Therefore, with the sensor case 33 filled with the adhesive 61 facing downward, the sensor cover 39 is put on the sensor case 33 in which the sensor housing 37 has been housed, and the sensor cover 39 is inserted into the insertion opening 50. 4, the lead wire 45 connected to the rotation detecting means 35 housed in the sensor case 33 is led out to the side of the sensor case 33 as shown in FIG. It is not led out above 33. Therefore, the conventional problem that the lead wire 45 interferes with the welding operation can be solved, and the productivity can be improved by speeding up the welding operation.

The specific configurations of the sensor case, the rotation detecting means, the sensor housing, the sensor cover, the pressing protrusions, and the like in the rotation detecting sensor of the present invention are not limited to the configurations of the above embodiment, It goes without saying that various forms can be adopted based on the spirit of the invention.

[0040]

As described above, according to the rotation detecting sensor of the present invention, after the sensor housing is housed at the predetermined position in the sensor case, the pressing housing urges the sensor housing in the inserting direction. Meanwhile, the sensor cover is welded to the insertion opening of the sensor case to seal the inside of the sensor case. Therefore, the sensor housing itself, which is positioned at a predetermined position by abutting a predetermined portion in the sensor case, does not have a portion welded to the sensor case, and the positioning position with respect to the sensor case does not vary.

Further, since the sensor housing housed at a predetermined position in the sensor case is held in a state of being pressed and biased in the insertion direction by the pressing protrusion of the sensor cover, there is no rattling. Therefore, the gap between the bottom of the sensor case and the tip of the rotation detecting means assembled in the sensor housing is always maintained at an appropriate value regardless of the variation in the melting amount between the sensor case and the sensor cover, so that stable detection is possible. Accuracy can be obtained. Therefore, it is possible to suppress an increase in manufacturing cost without the need to take measures to increase the molding accuracy of the welded portions of the sensor case and the sensor cover and the accuracy of the welding jig, which causes an increase in cost.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a state where a rotation detection sensor according to an embodiment of the present invention is disassembled.

FIG. 2 is an enlarged perspective view showing an inner surface of the sensor cover shown in FIG.

FIG. 3 is a vertical cross-sectional view showing a state where a sensor housing is attached to the sensor case shown in FIG.

FIG. 4 is a vertical cross-sectional view of a state in which the rotation detection sensor shown in FIG. 1 is assembled.

FIG. 5 is a vertical cross-sectional view illustrating a mounting state of a conventional rotation detection sensor on a detected portion.

6 is a vertical cross-sectional view of the rotation detection sensor shown in FIG. 5 in an exploded state.

7 is a vertical cross-sectional view of the sensor case shown in FIG. 6 in which a sensor body is assembled.

[Explanation of symbols]

31 rotation detection sensor 33 sensor case 35 Rotation detecting means 37 sensor housing 39 sensor cover 39b Pressing protrusion 45 lead wire 47 Case side terminal 50 Insertion opening 57 Sensor side terminal

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Claims (2)

[Claims] 1. A rotation having a bottomed cylindrical sensor case, a sensor housing to which rotation detection means is assembled, and a sensor cover for sealing the inside of the sensor case in which the sensor housing is accommodated at a predetermined position. A detection sensor, wherein the sensor cover is welded to an insertion opening of the sensor case while pressing and urging the sensor housing in an insertion direction by a pressing protrusion provided on an inner surface of the sensor cover. A rotation detection sensor characterized by. 2. A sensor-side terminal to which a lead wire is connected is insert-molded in the sensor case, and the sensor housing is connected to the rotation detecting means and is connectable to the case-side terminal. The rotation detection sensor according to claim 1, wherein a side terminal is provided.