JP3236551B2 - 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 rotational speed sensor 71 shown in FIGS. 6 and 7 has already been developed.
As shown in FIG. 6, the rotational speed sensor 71 includes a sensor main body 72 and a fixing fitting 5 integrally fixed by a resin 6 at the time of insert molding .

[0004] As shown in both figures, the sensor main body 72 includes a reel 73 formed of resin and the coil 32 wound around the reel 73. As shown in FIG. 7, each of the two ends of the coil 32 and the signal cable 4
5, two terminals 43a and 43b (terminals 4a and 4b in FIG. 1) for relay connection with two cables 42a and 42b (hereinafter, also referred to as "cable 42" when not distinguished).
3a is fixed). Further, the reel 73 is formed with a cable holder 46 for holding the cable 42 while regulating the drawing direction of the cable 42 and an insertion hole 33 for press-fitting the core 2 from the direction of arrow A in FIG. The core part 2 is a magnet piece 2 formed in a flat shape.
1, stainless steel plate pole pieces 22, 22 fixed to sandwich both side surfaces of the magnet piece 21, and a groove 2 for determining a mounting angle when the rotation speed sensor 71 is mounted.
4 and 24 are integrally formed with the resin-made lid portion 23 formed.

In this rotational speed sensor 71, after winding the coil 32 around the reel 73, one end of the coil 32 is soldered to one end of the terminal 43a, and the coil 32
Is soldered to one end of the terminal 43b. Next, the cable 42a is crimped to the other end of the terminal 43a, and the cable 42b is crimped to the other end of the terminal 43b. Next, after press-fitting the core portion 2 into the insertion hole 33, FIG.
As shown in FIG. 7, by fitting both cables 42a and 42b into the groove of the cable holder 46,
a and 42b are held while being restricted in a predetermined direction. This prevents disconnection at the crimped portion of the cable 42 due to excessive routing. In addition,
The angle H between the width direction of the magnet piece 21 of the core 2 and the drawing direction X of the cable 42 shown in FIG.
Is determined in advance for each type of vehicle so that the signal cable 45 does not abut on the chassis of the vehicle or enter the sensing surface S described later. For this reason, in the rotation speed sensor 71, the insertion hole 33 of the reel 73 formed using a mold corresponding to the type of vehicle is used.
When the core portion 2 is press-fitted into the core member 2, the direction of the core portion 2 with respect to the drawing direction X in the width direction is uniquely determined by the angle H. Next, the sensor main body 72 and the fixing metal 5 temporarily fixed to a predetermined position with respect to the sensor main body 72 are insert-molded, so that the sensor main body 72 and the fixing metal 5 are integrally fixed by the resin 6. You.

Next, a method of attaching the rotation speed sensor 71 to an automobile will be described. First, the rotation speed sensor 71 is temporarily mounted by temporarily tightening a bolt inserted through the mounting hole 5a of the fixing metal fitting 5 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 71
Is fixed by bolts while adjusting the direction of the rotation speed sensor 71 so that the long direction of the gear and the face 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 the vehicle has been mounted,
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, an AC constant current is supplied to the coil 32 in the rotation speed sensor 71 via the signal cable 45 in advance. In this state, the magnetic flux of the sensor main body 72 changes as the peak portion GH or the valley portion GL of the gear G faces the sensing surface S. Therefore, by detecting the voltage value at the AC constant current supply source, The rotational speed of the gear G can be detected based on the number of times the peak G or GL of the gear G faces per unit time. In this rotational speed sensor 71, when the rotational speed sensor 71 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 can be detected most accurately. Is configured.

[0008]

However, the rotational speed sensor 71 already developed by the applicant has the following points to be improved. That is, the rotation speed sensor 71 is connected to the sensor main body 7 in the drawing direction X of the signal cable 45.
Since the direction of the second insertion hole 33 must be set to an angle H which is predetermined for each vehicle model to be mounted, the die of the sensor main body 72 must be manufactured for each vehicle 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 manufacturing cost increases due to the die cost. For this reason, the rotational speed sensor 71 already developed by the applicant has an improvement that the manufacturing cost should be reduced.

On the other hand, the overall shape of the core portion 2 is formed in a cylindrical shape, and the insertion hole 33 is also formed in a round hole into which a cylindrical magnet piece can be press-fitted. It is also possible to arbitrarily change the angle H between the signal cable 45 and the drawing direction X. In this case, since the direction of the magnet piece 21 may be adjusted when the core portion is press-fitted, the sensor body 72 can be used in common even if the vehicle type is different, so that only one type of die is required. However, when a reel having the same outer diameter as the reel 73 in the rotation speed sensor 71 is used, by forming a cylindrical insertion hole, the reel becomes thinner and thus weaker in strength. Therefore, in order to secure the strength of the reel, the diameter of the reel must be increased. For this reason, it is extremely difficult to employ a rotational speed sensor having such a structure under the current situation where downsizing is required due to the mounting space.

It is also conceivable that the cable 42 is pulled out directly behind the sensor main body 72, or drawn out in an arbitrary direction during insert molding without being fixed by the cable holder 46. However, in the former case,
As described above, the signal cable 45 may come into contact with the chassis of the vehicle, and in the latter case, the cable 4
There is a problem that the cable 42 may come off from the terminal 43 as a result of the burden on the crimping portion 2.

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 the manufacturing cost while maintaining the miniaturization.

[0012]

According to a first aspect of the present invention, there is provided a rotational speed sensor comprising:
It has two pole pieces that are fixed as if sandwiched
A sensor unit for outputting a detection signal for detecting the rotation speed of the rotating body from a signal output unit, a signal cable for outputting a detection signal to an external device, and a signal output unit for the sensor unit. e Bei and a terminal portion having a connection terminal for electrically connecting the sensor unit and the terminal
Parts are rotational speed sensors formed separately from each other.
One of the sensor section and the terminal section is
Equipped with a mating shaft, one of the sensor and the terminal
Has a fitting hole in which the fitting shaft can be press-fit in any direction.
Sensor part and terminal part
The angle between the magnet piece and the width direction is predetermined.
The fitting shaft is pressed into the fitting hole so that
Therefore, it can be integrated and the core part is a magnet piece
And a lid, wherein a groove is formed in the lid . Note that on the terminal unit, the signal cable and the signal output unit of the sensor unit may be directly connected, or a connector for connecting the signal cable and the signal output unit of the sensor unit may be provided in the terminal unit. The signal cable and the signal output unit of the sensor unit may be indirectly connected via the connector.

According to a second aspect of the present invention, there is provided a rotational speed sensor.
The rotation speed sensor described above is characterized in that the mounting direction of the sensor unit with respect to the rotating body is regulated, and the pull-out direction with respect to the sensor unit is regulated by fixing the signal cable.

According to a third aspect of the present invention, there is provided a rotational speed sensor according to the first aspect.
Or the rotational speed sensor according to 2, wherein the sensor unit includes a winding unit including a reel and a coil wound on the reel.

In the rotational speed sensor according to any one of the first to third aspects, the sensor unit is manufactured by using the mold for the sensor unit, and the terminal unit is manufactured by using the mold for the terminal unit. Thus, separate sensor units and terminal units are manufactured respectively. Next, the two parts are integrally fixed to each other. At this time, since both parts are separate,
The mounting direction of the sensor unit with respect to the terminal unit can be arbitrarily determined. In this case, first,
Determining the direction of attachment of the subsection. Next, the sensor section
Or the terminal part) to the fitting shaft for fitting.
Into the fitting hole formed in the part (or sensor part)
No. As a result, the two parts are oriented in a predetermined direction with respect to each other.
It is precisely integrated as it is. So, for example,
When a rotational speed sensor is attached to an automobile, the orientation of attachment of the sensor unit to the terminal unit can be determined so as to match the type of the vehicle. For this reason, it is not necessary to manufacture a mold for the rotation speed sensor for each vehicle type, and only two kinds of molds for the sensor unit and the terminal unit are manufactured in advance. It becomes possible to manufacture a rotational speed sensor suitable for the pull-out direction.

[0016]

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 71 that have already been developed by the applicant are denoted by the same reference numerals, and redundant description will be omitted.

As shown in FIGS. 1 and 2, the rotational speed sensor 1
Is configured to include a core unit 2 and a winding unit 3 corresponding to a sensor unit in the present invention, and a terminal unit 4. Similarly to the rotation speed sensor 71, the core portion 2 includes a magnet piece 21 formed in a flat plate shape, pole pieces 22, 22 made of stainless steel fixed so as to sandwich both sides of the magnet piece 21, Resin lid 2 in which grooves 24 for determining the mounting angle when mounting sensor 1 are formed.
3 are integrally formed. In this case, silicon is buried in the central part of the surface of the lid part 23 (that is, the sensing surface S) 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, A groove 24 is formed by partially recessing the pole pieces 22, 22 in the width direction. The winding portion 3 has a cylindrical shape as a whole and includes a reel 31 for winding the coil 32. One side of the reel 31 has an insertion surface for press-fitting the core portion 2. A hole 33 is formed, and a fitting shaft 34 formed in a cylindrical shape is formed on the other side surface.

On the other hand, the terminal portion 4 is provided with a terminal portion main body 41, and the terminal portion main body 41
4 and a cable 42a,
A cable holder 46 for holding the cable 42b while restricting the pull-out direction of the cable 42b is formed. Also, the terminal section 4 has 2
One terminal 43a, 43b is formed integrally with the terminal body 41, and both terminals 43a, 43b are connected to both ends of the coil 32 (these correspond to a signal output unit in the present invention) and a signal cable 45 ( 3) is used for relay connection between the two cables 42a and 42b. The terminal 43a (and 43b) has a part thereof.
The two terminals 43a, 43a (and 43b, 4) which are buried in the resin at the time of molding and are separated as shown in FIG.
3b) is actually one piece, and the terminal body 4
1 are connected to each other.

When assembling the rotational speed sensor 1,
First, the core piece 2 is formed by integrating the magnet piece 21 and the lid 23 sandwiched between the pole pieces 22 and 22 by bonding. Next, the coil part 32 is wound around the reel 31 to manufacture the winding part 3, and the core part 2 is pressed into the insertion hole 33 of the winding part 3 from the direction A in FIG. Thereby, the sensor unit is assembled. Next, the cable 42a is connected to the terminal 43.
a, and the cable 42 b is connected to the terminal 43.
After crimping to one end of the cable b, the two cables 42a and 42b are fitted into the groove of the cable holder 46 to restrict the pull-out direction X of the two cables 42a and 42b in a predetermined direction as shown in FIG. And hold it. Subsequently, the fitting shaft 34 of the winding part 3 is pressed into the fitting hole 44 of the terminal part 4 in the direction of arrow B shown in FIG. At this time, FIG.
As shown in (b), the angle H between the drawing direction X of the cable 42 and the width direction of the magnet piece 21 of the core part 2 is formed.
Then, the winding portion 3 is press-fitted into the fitting hole 44 while being adjusted so as to have a predetermined angle for each vehicle type. Next, one end of the coil 32 is soldered to the other end of the terminal 43a, and the other end of the coil 32 is connected to the terminal 43b.
Solder to the other end. Thereby, the winding part 3 and the terminal part 4 are integrated.

Next, after the integrated winding part 3 and terminal part 4 and the fixing metal fitting 5 temporarily fixed at a predetermined position with respect to these are set in a mold, resin is poured into the mold to perform insert molding. I do. Thereby, the winding part 3, the terminal part 4, and the fixing metal member 5 are integrally fixed by the resin 6, and the rotation speed sensor 1 is completed.

Next, for example, when it is mounted on the chassis of an automobile, it is mounted in the same manner as the conventional rotational speed sensor 71. At this time, as shown in FIG. 4 (a), if 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 45 Is pulled out in a predetermined direction,
As shown in FIG. 3B, the width direction of the magnet piece 21 is also parallel to the width direction of the groove 24, and consequently, becomes parallel to the tooth width direction of the gear G.

As described above, according to the rotational speed sensor 1, by fitting the fitting shaft 34 into the fitting hole 44,
At this time, the direction of attachment of the sensor unit to the terminal unit 4 can be arbitrarily determined, and the winding unit 3 and the terminal unit 4 formed separately 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 winding portion 3 and the terminal portion 4. Therefore, as a result of reducing the cost of the mold, it is possible to reduce the manufacturing cost of the rotational speed sensor 1 while maintaining the miniaturization.

The present invention is not limited to the configuration shown in the embodiment of the present invention. For example, in the present embodiment, the fitting shaft 34 is formed in the winding part 3 and the fitting hole 44 is formed in the terminal part 4, but the fitting hole is formed in the winding part 3 and the terminal part 4 is formed.
May be formed with a fitting shaft. However, in this case, the length of the reel 31 is increased in order to avoid contact between the core portion 2 press-fitted into the insertion hole 33 of the winding portion 3 and the fitting shaft. For this reason,
It is preferable to adopt the configuration of the rotation speed sensor 1 shown in the embodiment of the present invention. Further, the fitting shaft 34 and the fitting hole 4
Instead of forming the wire 4, the winding portion 3 and the terminal portion 4 can be integrated by bonding or welding with an adhesive. Furthermore, the winding part 3 and the terminal part 4 are not limited to the shapes shown in the embodiment of the present invention, and can be appropriately changed.

Further, the sensor section in the present invention is not limited to the configuration of the core section 2 and the winding section 3, but may be configured using a magnetoresistive element such as an MR element or a Hall element.
In addition, the rotation speed sensor according to the present invention is not limited to the detection of the rotation speed of the wheel, and can be applied to various uses. Of course, and it is a matter of course that the mounting position is not limited.

[0025]

As described above, according to the rotational speed sensor according to the first to third aspects, the sensor section and the terminal section are formed separately, and one of the sensor section and the terminal section is provided.
Has a fitting shaft for fitting, and has a sensor section and a terminal section.
On the other hand, the fitting shaft can be press-fitted in any direction.
With a mating hole, the sensor section and terminal section are
The angle between the drawing direction and the width direction of the magnet
Press the fitting shaft into the fitting hole so that the angle is
Since it is configured to be integrated by being inserted, only two types of molds for the sensor unit and the terminal unit are manufactured in advance, and the mounting direction of the sensor unit to the rotating body and the signal cable Various rotational speed sensors that comply with the restrictions on the direction in which the terminal portion is pulled out can be manufactured. Accordingly, it is not necessary to manufacture a plurality of dies corresponding to the drawing direction of the signal cable and the like, and the sensor portion and the terminal portion can be used in common, so that the manufacturing cost of the dies can be significantly reduced. . As a result, it is possible to significantly reduce the manufacturing cost while keeping the rotation speed sensor small.

Also, the core part is composed of a magnet piece and a lid.
Equipped with a groove in the lid, for example, automatic
When installing on the car chassis, the long direction and rotation speed of the groove
Make the tooth width of the gear to be detected parallel to
By attaching the magnet piece, the width direction of the magnet piece is
Can be parallel.

[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.

FIG. 2 is a cross-sectional view of the rotational speed sensor according to the embodiment of the present invention after assembly.

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.

FIG. 6 is a cross-sectional view showing an internal structure of a rotational speed sensor that has been already developed by the applicant after assembly.

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 Core part 3 Winding part 4 Terminal part 31 Reel 32 Coil 34 Fitting shaft 44 Fitting hole 45 Signal cable G Gear

Continuing from the front page (72) Inventor Kozo Ogino 8000 Nakase, Hamakita City, Shizuoka Prefecture Nisshinbo Industries, Inc. Hamakita Seiki Factory (56) References JP-A-8-43415 (JP, A) JP-A-2-232579 ( JP, A) JP-A-60-159610 (JP, A) JP-A-6-294803 (JP, A) JP-A-8-194006 (JP, A) JP-A-2-296307 (JP, A) Hei 6-87871 (JP, U) Actually open Hei 4-7367 (JP, U) (58) Fields studied (Int. Cl. ⁷ , DB name) G01P 3/488 G01D 5/245

Claims (3)

(57) [Claims] (1) so as to sandwich both side surfaces of a magnet piece;
With a core part having two pole pieces
And a sensor unit for outputting a detection signal for detecting the rotation speed of the rotating body from a signal output unit, a signal cable for outputting the detection signal to an external device, and the signal output unit of the sensor unit. e Bei and a terminal portion having a connection terminal for connecting the sensor unit and before
The rotation speed sensors are separately formed
A is either one of the sensor portion and the terminal portion, the fitting
A fitting shaft for the sensor, the other of the sensor portion and the terminal portion,
The fitting shaft is provided with a fitting hole that can be press-fitted in an arbitrary direction, and the sensor unit and the terminal unit are provided in the signal cable.
Angle between the pull-out direction and the width direction of the magnet piece
So that the fitting shaft is positioned at a predetermined angle.
Press-fit into the fitting hole to enable integration.
The core portion includes the magnet piece and a lid portion,
A rotation speed sensor, wherein a groove is formed in the lid . 2. The rotation according to claim 1, wherein an attachment direction of the sensor unit with respect to the rotating body is regulated, and a pull-out direction with respect to the sensor unit is regulated by fixing the signal cable. Speed sensor. 3. The rotation speed sensor according to claim 1, wherein the sensor unit includes a winding unit including a reel and a coil wound on the reel. .