JP3236554B2 - Rotation speed sensor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotation speed sensor for detecting a rotation speed of a rotating body and the like, and more particularly to an ABS for an automobile or the like.
The present invention relates to a rotation speed sensor suitable for detecting a rotation speed of a wheel in an (Anti-lock Brake System).

[0002]

2. Description of the Related Art A rotational speed sensor used for detecting a rotational speed of a wheel in an ABS mounted on an automobile is, for example, provided near a gear rotating with the wheel, a tooth tip of the gear and a rotational speed sensor. The sensing surfaces are fixed so as to face each other, and a detection signal corresponding to the rotation speed of the wheel is output by detecting a change in magnetic flux accompanying rotation of the gear.

As a rotational speed sensor of this type, the applicant has
The two-pole piece type rotational speed sensor 41 shown in FIGS. 6A, 6B and 7 has already been developed. As shown in FIG. 6, the rotational speed sensor 41 includes a sensor main body 47 integrally fixed with the resin 5 at the time of insert molding, and the fixing bracket 4. Sensor body 4
Reference numeral 7 denotes a magnet part 42 and a winding part 4 as shown in FIG.
3 is provided.

[0006] As shown in FIGS. 6 and 7, the magnet part 42 is composed of a columnar insertion part 42 a and a disk-shaped lid part 42 b. In this case, the insertion portion 42a is a resin-made pole piece at the time of insert molding. It is integrally formed by a cover 44, and is press-fitted into an insertion hole 46 described later formed in the winding part 43. On the other hand, grooves 24, 24 for determining the mounting angle when the rotation speed sensor 41 is mounted are formed in the lid 42b.

As shown in FIG. 1, the winding part 43 includes a reel 45 formed of resin and the coil 32 wound around the reel 45. The reel 32 includes the coil 32
And two cables 33 in the signal cable 6
a, 33b (hereinafter referred to as “cable 3
3 ").
a, 34b (only the terminal 34a is shown in the figure) is fixed. In addition, the reel 45 includes a cable 33.
Cable holder 3 that holds the cable while restricting the pull-out direction
6 and an insertion hole 46 for press-fitting the insertion portion 42a of the magnet portion 42 from the direction of arrow A in FIG.

In this rotational speed sensor 41, after winding the coil 32 around the reel 45, one end of the coil 32 is soldered to one end of the terminal 34a, and the coil 32
Is soldered to one end of the terminal 34b to form a winding part 43. Next, the cable 33a is connected to the terminal 34a.
And the cable 33b is connected to the other end of the terminal 34b.
Crimp to the other end. Next, the insertion part 4 of the magnet part 42
After the sensor main body 47 is formed by press-fitting the cable 2a into the insertion hole 46, as shown in FIG.
By fitting the cable 3b into the groove of the cable holder 36, the cable 33a and the cable 33b are held while regulating the drawing direction X of the cable 33a and 33b in a predetermined direction. This prevents a break in the crimped portion of the cable 33 due to excessive routing. The angle H between the drawing direction X of the cable 33 and the width direction of the magnet piece 21 of the magnet section 42 shown in FIG. 4B is determined by the signal cable 6 contacting the chassis of the automobile or the sensing surface S described later. It is determined in advance for each type of vehicle so that the signal cable 6 does not enter the inside. For this reason, in the rotational speed sensor 41, if the magnet part 42 is press-fitted into the insertion hole 46 of the reel 45 formed using a mold corresponding to the vehicle type, the direction of the magnet part 42 with respect to the drawing direction X in the width direction becomes an angle. H is uniquely determined. Next, the sensor main body 47 and the fixing metal fitting 4 temporarily fixed to a predetermined position with respect to the sensor main body 47 are insert-molded, so that the sensor main body 47 and the fixing metal fitting 4 are integrally fixed by the resin 5. You.

Next, a method of attaching the rotational speed sensor 41 to an automobile will be described. First, the rotation speed sensor 41 is temporarily mounted by temporarily tightening a bolt inserted through the mounting hole 4a of the fixing bracket 4 into a screw hole formed in advance in the vicinity of the gear to be detected of the rotation speed. Next, FIG.
As shown in (a), the grooves 24, 24 of the rotational speed sensor 41
Is fixed by bolts while adjusting the direction of the rotation speed sensor 41 so that the lengthwise direction of the gear G and the width direction of the gear G to be rotation speed detected are parallel to each other. In this state, the gear G
4B is located at the center of the sensing surface S, and the width direction of the magnet piece 21 is also parallel to the width direction of the groove 24 as shown in FIG. It becomes parallel to the face width direction of G.

After installation, if the car runs,
The rotation of the gear G together with the wheels causes the peaks GH and the valleys GL of the gear G to alternately face the sensing surface S. At this time, the rotation speed sensor 4 is connected via the signal cable 6.
A constant current of alternating current is supplied to the coil 32 in 1 in advance.
In this state, the magnetic flux of the sensor main body 47 changes in accordance with the peak GH or the valley GL of the gear G facing the sensing surface S. Therefore, by detecting the voltage value at the AC constant current supply source, Mountain G of gear G per unit time
The rotation speed of the gear G can be detected based on the number of times H or the valley GL faces. In the two-pole piece type rotational speed sensor 41, when the rotational speed sensor 41 is mounted such that the width direction of the magnet piece 21 and the tooth width direction of the gear G are parallel to each other, the change in magnetic flux is most reduced. It is configured to be able to detect accurately.

[0009]

However, the rotational speed sensor 41 already developed by the applicant has the following points to be improved. In other words, the rotation speed sensor 41 needs to set the direction of the insertion hole 46 of the winding part 43 with respect to the drawing direction X of the signal cable 6 to an angle H that is predetermined for each type of vehicle to be mounted.
5 molds must be manufactured for each model. Therefore, if the number of types of vehicles increases, it is necessary to manufacture a die suitable for each type of vehicle, so that the production cost increases due to the die cost. For this reason, the rotational speed sensor 41 already developed by the applicant has an improvement that the manufacturing cost should be reduced.

On the other hand, it is conceivable that the cable 33 is pulled out directly behind the sensor main body 47 or drawn out in an arbitrary direction during insert molding without being fixed by the cable holder 36. However, in the former case,
As described above, the signal cable 6 may come into contact with the chassis of the automobile, and in the latter case, the cable 33
As a result, a load is applied to the crimping portion of
There is a problem that it may be deviated from the number 4.

The present invention has been made in view of such improvements, and has as its main object to provide a rotational speed sensor capable of reducing manufacturing costs.

[0012]

According to a first aspect of the present invention, there is provided a rotational speed sensor having a winding portion in which a coil connected to a sensor signal output cable is wound and an insertion hole is formed. And the insertion part and insertion
Magnet consisting of a lid integrated with the inlet
And press-fit the insertion part into the insertion hole.
In the rotation speed sensor in which the wire portion and the magnet portion are integrated , the insertion hole and the insertion portion are configured so that the insertion portion can be inserted into the insertion hole at an arbitrary rotation angle with respect to the insertion direction into the insertion hole , Insert the magnet into the magnet
And fix both sides of the magnet piece
Two pole pieces are integrated with resin
Silicon is embedded in the lid and the lid is
A groove is formed by recessing a part of the recon .

According to a second aspect of the present invention, there is provided a rotational speed sensor.
In the rotation speed sensor described above, the insertion portion is formed in a columnar shape.

According to a third aspect of the present invention, there is provided a rotational speed sensor according to the first aspect.
Alternatively, in the rotational speed sensor according to 2, the insertion hole is formed in a round hole.

In the rotation speed sensor according to the first to third aspects,
The winding part is manufactured by the mold for the winding part, and the magnet part is manufactured by the mold for the magnet part. Next, the insertion part of the magnet part is inserted into the insertion hole formed in the winding part, and both parts are integrally fixed. At this time, by inserting the insertion portion in the posture into the insertion hole in a state where the magnet portion is rotated at an arbitrary rotation angle with the insertion direction into the insertion hole as the virtual rotation axis, the magnet portion with respect to the winding portion is The direction of attachment can be arbitrarily determined. Therefore,
For example, when a rotational speed sensor is mounted on an automobile, the mounting direction of the magnet unit with respect to the winding unit can be determined so as to match the vehicle type. For this reason, it is not necessary to manufacture a mold for the rotation speed sensor for each vehicle type, and only by manufacturing two kinds of molds for the winding part and the magnet part, various kinds of predetermined signal cables can be used. It becomes possible to manufacture a rotational speed sensor suitable for the pull-out direction. This makes it possible to significantly reduce the manufacturing cost. In addition, silicon is embedded in the lid of the magnet
As a result, the gears that are to be detected
The magnetic show caused by the adhesion of iron powder generated by
Can be prevented from being triggered.

Further , it is necessary to fix the insertion portion and the insertion hole to each other so that the insertion portion inserted into the insertion hole does not rattle. In this case, various methods such as adhesion and welding can be considered as a method of fixing, but in such a method, it is necessary to perform a heat treatment for applying or welding the adhesive, and the manufacturing cost is reduced. Soar. On the other hand, in this rotational speed sensor, for example, by inserting an insertion portion formed slightly thicker than the hole diameter of the insertion hole into the insertion hole, the winding portion and the magnet portion are fixed to each other. This makes it possible to manufacture the rotation speed sensor by easily and quickly integrating the winding portion and the magnet portion without the need for applying an adhesive or performing a heat treatment. Therefore, the manufacturing cost is
It is possible to further reduce.

[0017]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a rotational speed sensor according to the present invention;
An embodiment applied to an S sensor will be described. Note that the same components as those of the rotational speed sensor 41 that have already been developed by the applicant are denoted by the same reference numerals, and redundant description will be omitted.

As shown in FIG. 2, the rotational speed sensor 1
A pole piece type sensor body 7 and a fixing bracket 4 which are integrally fixed by, for example, a nylon resin 5 (hereinafter, referred to as “resin 5”) during insert molding.
It is comprised including. Also, as shown in FIG.
The sensor main body 7 includes a magnet unit 2 and a winding unit 3.

As shown in FIGS. 1 and 2, the magnet portion 2 is composed of a cylindrical insertion portion 2a formed in the winding portion 3 and press-fitted into an insertion hole 35 described later, and a disk-shaped lid portion 2b. ing. In this case, the insertion portion 2a is formed by, for example, a nylon resin 23 ( Hereinafter, it is integrated by the “resin 23”) and the diameter thereof is formed slightly larger than the diameter of the insertion hole 35. When insert molding, the resin 23
Thereby, the lid 2b is formed integrally with the insertion portion 2a.
In addition, the center part of the surface of the lid part 2b (that is, the sensing surface S)
In this case, silicon is buried so as not to induce a magnetic short circuit due to the adhesion of iron powder generated due to wear of gears and the like, and a part of the silicon is depressed in parallel with the width direction of the pole pieces 22, 22. Groove 2
4 are formed. In this case, the grooves 24 are used to determine the mounting angle when the rotational speed sensor 1 is mounted.

The winding portion 3 is formed in a cylindrical shape as a whole and has a reel 31 for winding a coil 32. One side of the reel 31 has a circular shape capable of press-fitting the insertion portion 2a. A hole insertion hole 35 is formed. On the other side, a cable holder 36 for holding the cable 33a, 33b while regulating the drawing direction and two terminals 34a, 34b are provided. In this case, both terminals 34a and 34b are connected to both ends of the coil 32 and the two cables 33a and 3 in the signal cable 6 (see FIG. 3).
3b. The terminal 34a (and 34)
b) is partially buried in the resin when the reel 31 is molded, and the two terminals 34a, 34a (and 34b, 34b) in the separated state shown in FIG. And are connected to each other within the reel 31.

When assembling the rotational speed sensor 1,
First, after the magnet piece 21 sandwiched between the pole pieces 22 and 22 is set in a mold, a resin 23 is poured into the mold to perform insert molding. Thereby, the lid 2a and the insertion part 2b are formed integrally. Next, the magnet part 2 is formed by embedding silicon in the center part of the surface of the lid part 2a. Next, after winding the coil 32 around the reel 31 manufactured by insert molding, one end of the coil 32 is soldered to one end of the terminal 34a,
The other end is soldered to one end of the terminal 34b. Subsequently, the cable 33a is crimped to the other end of the terminal 34a, and the cable 33b is crimped to the other end of the terminal 34b.
As shown in (a), by fitting both cables 33a, 33b into the groove of the cable holder 36, the cables 33a, 33b are held while regulating the drawing direction X of the cables 33a, 33b in a predetermined direction. Thereby, the winding part 3 is formed.

Next, the insertion hole 3 of the winding part 3 after molding is formed.
5 shows the insertion part 2a of the magnet part 2 from the direction A shown in FIG.
Press-fit. At this time, as shown in FIG. 5 (b), the angle H between the drawing direction X of the cable 33 and the width direction of the magnet piece 21 of the magnet unit 2 is set to an angle predetermined for each vehicle type. The insertion part 2a of the magnet part 2 is press-fitted into the insertion hole 35 of the winding part 3 while making adjustments as described above. Thereby, the winding part 3 and the magnet part 2 are integrated, and the sensor main body 7 is assembled.

Next, after the sensor main body 7 and the fixing fitting 4 temporarily fixed at a predetermined position with respect to the sensor main body 7 are set in a mold, a resin is poured into the mold to perform insert molding. Thereby, the sensor main body 7 and the fixing bracket 4 are integrally fixed. At the same time, as shown in FIG.
The magnet part 2 and the winding part 3 are fixed to each other by the resin 5. Next, for example, when attaching to a chassis of an automobile, it is attached in the same manner as the conventional rotational speed sensor 41. At this time, as shown in FIG. 4 (a), when the longitudinal direction of the groove 24 of the rotational speed sensor 1 and the tooth width of the gear G to be rotational speed detected become parallel to each other, the signal cable 6 Is drawn out in a predetermined direction, and the width direction of the magnet piece 21 is also parallel to the width direction of the groove 24 as shown in FIG.
Becomes parallel to the tooth width direction.

As described above, according to the rotational speed sensor 1, the insertion portion 2 of the magnet portion 2 is inserted into the insertion hole 35 of the winding portion 3.
By press-fitting a, the mounting direction of the magnet portion 2 with respect to the winding portion 3 can be arbitrarily determined at that time, and the magnet portion 2 and the winding portion 3 can be easily integrated. As a result, it is possible to manufacture the rotational speed sensor 1 suitable for various types of vehicles having different cable withdrawing directions only by using two types of molds for manufacturing the magnet unit 2 and the winding unit 3. Therefore, as a result of reducing the cost of the mold, the rotation speed sensor 1
Manufacturing cost can be reduced.

Note that the present invention is not limited to the configuration shown in the embodiment of the present invention. For example, in the embodiment of the present invention, the lid portion 2b of the magnet portion 2 is formed in a disk shape, but the magnet portion 2 is formed in a columnar shape, and the grooves 24, 24 are formed in an end surface on one end side. You can also.
Further, in the embodiment of the present invention, the insertion hole 35 is formed in a round hole, and the insertion portion 2a is formed in a columnar shape. However, the present invention is not limited to this, and the insertion portion 2a is inserted so that the insertion portion 2a can be inserted. The hole may be formed in a square hole, or the insertion portion may be formed in a square shape or a polygonal shape so that the insertion portion can be inserted into the round insertion hole 35. Further, in the embodiment of the present invention, the insertion portion 2
Although the diameter of “a” is slightly larger than the diameter of the insertion hole 35, the diameter of the insertion portion 2 a may be smaller than the diameter of the insertion hole 35. In this case, for example, the insertion hole 3
A plurality of protrusions protruding toward the center of 5 may be formed along the circumferential direction of the inner wall of the insertion hole 35. With this configuration, when inserting the insertion portion 2a, the insertion portion 2a itself is inserted while crushing the plurality of protrusions, so that the insertion portion 2a and the insertion hole 35 are completely adhered to each other. be able to. In addition, it is also possible to form the folds by continuously forming the protrusions.

In the embodiment of the present invention, the rotational speed sensor 1 is formed by integrating the magnet portion 2 and the winding portion 3 and then performing insert molding. However, the present invention is not limited to this. After the unit 3 and the fixing bracket 4 are integrated by insert molding, the insertion hole 35 of the reel 31 is formed.
By press-fitting the insertion part 2a of the magnet part 2 into
The magnet part 2 and the winding part 3 can be integrated. Furthermore, the rotation speed sensor according to the present invention is not limited to the detection of the rotation speed of the wheels, and can be applied to various uses. Even when mounted on an automobile, it can be directly mounted on a chassis or a disk brake flange. Of course, and it is a matter of course that the mounting position is not limited.

[0027]

As it is evident from the foregoing description, according to the rotation speed sensor mounting according to claim 1, by the insertion portion is insertably arranged in any rotational angle with respect to the insertion hole, winding unit By simply fabricating two types of molds for the magnet part in advance, various rotational speed sensors suitable for the mounting direction of the magnet part and the drawing direction of the sensor signal output cable can be manufactured. This eliminates the need to manufacture a plurality of dies corresponding to the direction in which the sensor signal output cable is pulled out, and thus can significantly reduce the manufacturing cost of the dies. In addition, since the winding part and the magnet part can be used in common for various types of rotational speed sensors, the manufacturing cost of the rotational speed sensor can be significantly reduced.
In addition, silicon is embedded in the lid of the magnet
This means that, for example, the gears to be
Magnetic short-circuit due to adhesion of iron powder generated by wear
Can be prevented. Also, part of the silicon
By forming the groove by the
The mounting angle when mounting the sensor can be determined.

According to the rotational speed sensor of the second and third aspects, the insertion hole is formed in a round hole or the insertion portion is formed in a columnar shape, so that the winding portion and the magnet portion can be simplified. Can be manufactured. Further, when the insertion hole is formed in a round hole and the insertion portion is formed in a columnar shape, the two are in planar contact with each other, so that the two can be surely integrated without play.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a rotational speed sensor according to an embodiment of the present invention before assembly.

FIGS. 2A and 2B are cross-sectional views illustrating an internal structure of a rotational speed sensor according to an embodiment of the present invention after assembly, where FIG. 2A is a vertical cross-sectional view and FIG. It is.

FIG. 3 is an external perspective view of the rotational speed sensor according to the embodiment of the present invention after assembly.

FIG. 4 is an explanatory diagram of a rotational speed sensor according to an embodiment of the present invention and a rotational speed sensor that has already been developed by the applicant, and (a) is an explanatory diagram showing a relationship between a sensing surface and a gear; (B) is an explanatory view showing the relationship between the magnet pieces and the grooves.

FIG. 5 is a diagram of a rotational speed sensor according to an embodiment of the present invention and a rotational speed sensor already developed by the applicant;
(A) is a rear view of the rotational speed sensor before the insert molding of the rotational speed sensor showing the cable drawing direction X, and (b) is a rotational speed sensor of the rotational speed sensor before the insert molding showing the angle H between the magnet piece and the cable drawing direction. It is the front view which cut out a part.

FIGS. 6A and 6B are cross-sectional views showing the internal structure of the rotational speed sensor that has already been developed by the applicant after assembly, in which FIG. 6A is a vertical cross-sectional view and FIG. 6B is a radial cross-sectional view. It is.

FIG. 7 is an exploded perspective view of a rotational speed sensor that has already been developed by the applicant before assembly.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rotation speed sensor 2 Magnet part 2a Insertion part 3 Winding part 6 Signal cable 21 Magnet piece 23 Resin 31 Reel 32 Coil 35 Insertion hole

────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Kozo Ogino 8000 Nakase, Hamakita City, Shizuoka Prefecture Inside of Nisshinbo Industries, Ltd. Hamakita Seiki Factory JP-A-159685 (JP, A) JP-A-7-113812 (JP, A) JP-A-60-159610 (JP, A) JP-A-6-294803 (JP, A) JP-A-2-296307 (JP, A) (4) Field surveyed (Int. Cl. ⁷ , DB name) G01P 3/488 G01D 5/245 G01P 1/02

Claims (3)

(57) [Claims] A coil connected to a sensor signal output cable is wound, and a winding portion having an insertion hole formed therein, an insertion portion including a magnet piece, and an integral portion with the insertion portion.
And a magnet section consisting of a lid formed
By press-fitting the insertion portion into the insertion hole,
In a rotation speed sensor in which a winding part and the magnet part are integrated , the insertion hole and the insertion part may be inserted into the insertion hole at an arbitrary rotation angle with respect to a direction of insertion into the insertion hole. insertably constructed respectively, the insertion portion in the magnet part, the the magnet
And fix both sides of the magnet piece.
Two pole pieces are integrated with resin
Configured Te, the silica together with the lid, is embedded silicon
A rotation speed sensor, wherein a groove is formed by depressing a part of a capacitor . 2. The rotational speed sensor according to claim 1, wherein the insertion portion is formed in a column shape. 3. The rotation speed sensor according to claim 1, wherein the insertion hole is formed in a round hole.