JP2000221205A - Apparatus for detecting rotational speed - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify a recovery work when a sensor fails in a rotational speed- detecting apparatus. SOLUTION: A rotational speed-detecting device 6 has a pulsar ring 10 and a sensor 20. The sensor 20 is set to a use object via a supporting annular body 40. At least two planned areas 47 for setting sensors are provided in a circumferential direction of the supporting annular body 40, which are opened by applying an external force. In this case, in a form for setting the sensor 20 to the supporting annular body 40, the areas 47 are opened thereby forming sensor pockets, and the sensor 20 is fitted in the sensor pockets. When the sensor 20 fails as it is used, a cord wire 21 of the sensor 20 is cut and left without being separated from the supporting annular body 40, and planned different area 47 for setting sensors are opened to the supporting annular body 40 in the same manner as above, so that a fresh sensor 20 can be mounted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotation speed detecting device for detecting a rotation speed of a rotating member. This rotation speed detecting device is used, for example, as information input means in an antilock brake system (ABS) of an automobile.

[0002]

2. Description of the Related Art Generally, in the above-mentioned ABS, a rotational speed detecting device is mounted on a hub unit of a vehicle in order to detect a rotational speed of a wheel.

[0003] There are two types of this rotational speed detecting device, a so-called passive type and an active type, depending on the type of detection. Both types have a configuration in which a pulsaring and a sensor are combined.

There are two types of hub units to which the rotation speed detecting device is mounted, one for a drive axle and one for a driven axle. In each case, a pulsar ring is provided on the rotating side member of the hub unit. Further, the sensor is attached to the non-rotational side member of the hub unit.

Incidentally, a pulsaring device and a sensor having different structures and functions are used between the passive type and the active type of the rotational speed detecting device as described below.

In the case of the passive type, the pulsaring is
In this configuration, a plurality of windows are provided at equal intervals in the circumferential direction of a cylindrical or annular plate-shaped magnetic material, and the sensor includes a magnet and a detection coil that detects a change in magnetic flux density.
In this case, when the relative position with respect to the sensor changes with the rotation of the pulsar ring, the magnetic flux density of the magnet of the sensor periodically changes due to this change, and the periodic change of the magnetic flux density is detected by the detection coil. I do.

In the case of the active type, the pulsaring has a configuration in which magnetic poles having different polarities are provided alternately in the circumferential direction, and the sensor is composed of a Hall element for detecting the direction of a magnetic field (lines of magnetic force). In this case, when the relative position with respect to the sensor changes one by one with the rotation of the pulsaring, the direction of the magnetic field passing through the sensor is periodically inverted by the change. Then, the sensor detects the above-described periodic reversal of the direction of the magnetic field, and outputs a pulse signal having a frequency corresponding to the rotation speed of the pulsaring. This pulse signal is
The signal is input to a signal processing circuit of an ABS (not shown), and the signal processing circuit recognizes the rotation speed of the wheel based on a pulse signal input from the sensor 40 and information input in advance such as a diameter of the wheel. It has become.

Incidentally, any of the above-described sensors is indirectly attached to the non-rotating side member via a support ring. In addition, the sensor is fixed to the support ring.

[0009]

In the above prior art, since the sensor is fixed to the supporting ring, if the sensor may fail suddenly or due to its life, it is necessary to replace the sensor. It is necessary to remove it, but in that case, it is not possible to remove only the sensor, it is necessary to remove it together with the support ring, which is troublesome.

On the other hand, in order to enable the detachment of the sensor alone, for example, as shown in JP-A-6-308145 and JP-A-9-263221, the sensor is attached to and detached from the support ring. It is conceived to be able to attach as possible.

In these examples, an engaging portion is provided on a part of the support ring attached to the non-rotating side member, and an elastic locking piece is provided on the main body of the sensor. On the other hand, it is hooked in a snap fit state. Thus, the sensor can be prevented from easily coming out of the support ring, and the sensor alone can be removed. In addition,
When removing the sensor, the operator may pinch and bend the elastic locking piece of the sensor with his / her finger so that the elastic locking piece is pulled out while the hooking of the elastic locking piece to the engaging portion is released.

By the way, in the above conventional example, when the sensor is removed from the support ring, a person has to perform a work of bending the elastic locking piece of the sensor, so that the work is not only troublesome, but also in a narrow place or the like. It is pointed out that it is difficult to work.

In view of such circumstances, an object of the present invention is to make it possible to simplify the repair work in the event of a sensor failure in a rotational speed detecting device.

[0014]

According to a first aspect of the present invention, there is provided a rotational speed detecting apparatus for detecting a rotational speed of a member on a rotating side of a cylindrical body and a shaft which are concentrically arranged so as to be relatively rotatable. A pulsar ring attached to the rotating side member, and a pulsar ring attached to the non-rotating side member in a state in which the pulsar ring is in non-contact and opposed to a required position in the circumferential direction of the pulsar ring and detects a change in a relative position due to rotation of the pulsar ring A sensor, and the sensor is attached to the non-rotating side member via a supporting ring attached to the non-rotating side member in a non-contact and facing state with the pulsar ring, and the supporting ring In at least two places in the circumferential direction, there are provided sensor mounting scheduled areas that are opened by application of external force related to sensor mounting.

According to a second aspect of the present invention, there is provided a rotational speed detecting device, wherein the supporting ring of the first aspect has a cylindrical portion concentric with at least the axis of the rotating member, and the sensor mounting portion is attached to the cylindrical portion. A scheduled area is provided.

According to a third aspect of the present invention, there is provided a rotational speed detecting device, wherein a groove or a slit is provided in a contour portion of the sensor mounting area according to the first or second aspect.

According to a fourth aspect of the present invention, in the rotational speed detecting device according to any one of the first to third aspects, the pulsar ring is provided with magnetic poles having different polarities alternately in the circumferential direction. A change in a magnetic field corresponding to a change in a relative position accompanying rotation of the pulsaring is detected.

In short, according to the present invention, in order to mount the sensor on the supporting ring, a sensor pocket is formed by applying an external force by pressing one of the sensor mounting areas on the supporting ring to apply an external force. Then, the sensor is fitted here. When the sensor breaks down due to the use of the sensor, the sensor is cut off, the cord is cut off, and the sensor is not removed from the support ring. The sensor may be opened and a new sensor may be attached.

As for the repair work related to the sensor failure as described above, it is only necessary to leave the failed sensor without removing it from the support ring and attach a new sensor to another place of the support ring. Work can be done very easily and quickly. In addition, by leaving the failed sensor without removing it, the sensor pocket there can be kept closed, so that the sealing performance is also ensured.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described based on embodiments shown in the drawings.

First, the configuration of a hub unit as an object to be used by the rotation speed detecting device of the present invention will be described. FIG.
FIG. 2 is a longitudinal sectional view showing a hub unit equipped with the rotation speed detecting device of FIG. 1. In the figure, 1 is a hub unit, 2 is a drive axle of an automobile, and 3 is an axle case of the automobile.

The hub unit 1 is of a type attached to a drive axle 2 of an automobile, and includes a hub wheel 4 and a bearing device 5.

The hub wheel 4 has an annular plate portion 4a to which wheels (not shown) are attached, and a shaft portion 4b to which the drive axle 2 is spline-fitted at the shaft center. A bearing device 5 is provided on the outer peripheral surface of the shaft portion 4b of the hub wheel 4.

The bearing device 5 is composed of a double-row outward-facing angular ball bearing using the outer peripheral surface of the shaft portion 4b of the hub wheel 4 as one inner ring, and is a single-row externally press-fitted outer periphery of the shaft portion 4b. , An outer ring 5b having two rows of raceways, a plurality of balls 5c arranged in two rows, and two crown retainers 5d, 5d. The outer ring 5b
A radially outward flange 5e is provided on the outer periphery of the axle 3, and is fixed to the axle case 3 via the flange 5e. That is, the bearing device 5 is used in a form in which the outer ring 5b is not rotated and the inner ring 5a is rotated.

The rotation speed detecting device 6 according to the present invention is attached to one shaft end portion of the bearing device 5 of the hub unit 1.

FIGS. 1 to 3 show a rotation speed detecting device according to an embodiment of the present invention. FIG. 1 is an exploded perspective view of a rotation speed detecting device, FIG. 2 is a perspective view showing a main part of a second support ring, and FIG. 3 is an explanatory view showing an operation of attaching a sensor to the second support ring. .

The rotation speed detecting device 6 includes a pulsaring 10
And a sensor 20. In this embodiment, a so-called active type is employed.

The pulsar ring 10 is made of a plastic magnet provided with magnetic poles having different polarities alternately in the circumferential direction. This plastic magnet is a well-known one, but is made of a magnetic metal material such as an injection molded product of synthetic resin mixed with magnetic powder or a sintered ferrite as a base material, and its S pole is alternately formed in a required angular direction in the circumferential direction. It is manufactured by magnetizing the N pole.

The sensor 20 is a well-known Hall IC. Although not shown in detail, the Hall IC has a structure in which an IC chip is molded with a protective cover made of a synthetic resin. In this embodiment, the shape of the protective cover of the sensor 20 is formed in a rectangular parallelepiped shape, and the code wire 21 is drawn out from the upper end thereof. Further, in the sensor 20, an IC chip is embedded so that a required area on one surface is used as a sensor surface, and a mark (not shown) indicating the sensor surface is written in the area serving as the sensor surface. .

The pulsar ring 10 is attached to the outer peripheral surface of the shaft end of the inner ring 5a of the bearing device 5, and the sensor 20 is mounted on the outer peripheral surface 5b of the bearing device 5 in the circumferential direction of the pulsar ring 10. It is attached to the position in a state of non-contact facing from the axial direction. These pulsaring 1
The attachment of the sensor 20 to the sensor 0 is performed indirectly via first and second support rings 30 and 40 described below.

The first support ring 30 has an upper half cross section substantially L
It consists of a ring-shaped iron plate press-formed in a letter shape. In the first support ring 30, the cylindrical portion 31 is press-fitted onto the outer peripheral surface of the shaft end of the inner ring 5a of the bearing device 5, and the pulsar ring 10 is attached to the outer surface of the annular plate portion 32 along the radial direction. Is done.

The second support ring 40 is formed of a ring-shaped iron plate press-formed in a plurality of stages. The second support ring 40 includes a small-diameter cylindrical portion 41 press-fitted on the inner peripheral surface of the shaft end of the outer ring 5b of the bearing device 5, and a first annular plate portion rising from the small-diameter cylindrical portion 41 outward in the radial direction. 42, a large-diameter cylindrical portion 43 connected to the outer end of the first annular plate portion 42, a radially inwardly falling from the large-diameter cylindrical portion 43, and the inner and outer rings 5 of the bearing device 5.
a second annular plate portion 44 for closing an annular space between a and 5b;
A cylindrical flange portion 45 is provided on the inner periphery of the second annular plate portion 44 and has a rubber lip 46 adhered to the inner peripheral surface thereof so as to be in contact with the outer peripheral surface of the drive axle 2. In addition, a rectangular sensor mounting area 47 is provided at two locations in the circumferential direction of the large-diameter cylindrical portion 43 and is opened by application of an external force. In order to easily open the sensor mounting area 47 by applying an external force, as shown in FIG. 2, a rectangular ring-shaped groove 48 is provided in the contour of the sensor mounting area 47 to make it thin.

When the sensor mounting area 47 of the second support ring 40 is opened, a rectangular sensor pocket 49 is formed, and the sensor 20 is fitted into the sensor ring 49 in the first annular shape. It is held in a state sandwiched by the gap between the plate portion 42 and the second annular plate portion 44. In order to enable such a holding form, the first annular plate portion 42
The width of the gap between the sensor and the second annular plate portion 44 is set to be substantially the same as the width of the rectangular sensor 20.

The procedure for attaching the sensor 20 to the second support ring 40 will now be described. That is, as shown in FIG. 3A, the sensor 20 is applied to the sensor mounting scheduled area 47 in the second support ring 40 from the outer diameter side, and the sensor 20 is pressed radially inward. As a result, as shown in FIG. 3B, the sensor mounting area 47 is cut off from the position of the groove 48 in the contour and becomes a fragment 47a and falls off to the inner diameter side. Are opened to form a sensor pocket 49, into which the sensor 20 is fitted. The sensor 20 is provided on the first and second annular plates 4 of the second support ring 40.
Since it is held in a state sandwiched between 2, 44, it does not easily fall off. The broken piece 47a separated from the sensor mounting area 47 is located in the space between the end face of the inner ring 5a and the second annular plate portion 44 of the second support ring 40, so that there is no problem.

The attachment of the sensor 20 is performed in the second
It does not matter whether the support ring 40 is mounted on the bearing device 5 or after.

Here, for example, in a state where the pulsar ring 10 and the sensor 20 are mounted on the bearing device 5 via the first and second support rings 30 and 40, the sensor surface of the sensor 20 is oriented in the axial direction with respect to the pulsar ring 10. It is necessary to face the sensor 20 from the second support ring 4
When the sensor 20 is attached to the sensor 20, it is necessary to carefully position the sensor 20 using the mark described on the protective cover of the sensor 20 as a mark.

Next, the operation of the active type rotational speed detecting device 6 will be described.

When the pulsar ring 10 rotates synchronously with the rotation of the hub wheel 4, each magnetic pole of the pulsar ring 10
The non-rotating sensor 20 is sequentially faced.
Here, the directions of the magnetic fields (lines of magnetic force) generated between the plural pairs of magnetic poles of the pulsar ring 10 are alternately opposite in the circumferential direction.
The direction of the magnetic field passing through is sequentially reversed at a cycle corresponding to the rotation speed. Therefore, the sensor 20 detects the above-described periodic reversal of the direction of the magnetic field, and outputs a pulse signal having a frequency corresponding to the rotation speed of the pulsar ring 10. This pulse signal is input to an ABS signal processing circuit (not shown), and based on the pulse signal input from the sensor 20 and the information such as the diameter of the wheel previously input, the hub wheel 4 It recognizes the rotation speed of the wheels attached to the vehicle.

Here, the sensor 20 of the rotation speed detecting device 6
If the sensor suddenly or fails due to its life, the sensor 20 needs to be replaced. In this embodiment, the following measures are taken.

That is, the code line 21 of the failed sensor 20 is cut and left without being detached from the second support ring 40, and the other sensor mounting area 47 in the second support ring is set in the above-mentioned manner. Similarly, a new sensor 20 may be attached by opening the opening.

As described above, when the sensor 20 fails, the sensor 20 is left without being detached from the second support ring 40, and the new sensor 20 is moved to another place of the second support ring 40. Since the repair is performed in the form of attachment, the repair work can be performed much simpler and easier than the trouble of removing the sensor 20 and attaching a new sensor 20 as in the conventional example. Become. If such a repair, especially sensor 2
This is advantageous because even if the periphery of the location where the 0 is arranged is narrow, it can be performed without any trouble.

It should be noted that the present invention is not limited to only the above embodiment, and various applications and modifications are conceivable.

(1) In the above embodiment, the second support ring 4
0, two sensor mounting areas 47 are provided.
Any two or more locations may be provided.

(2) In the above-described embodiment, the sensor 20 is inserted into the sensor pocket 49 of the second support ring 40 and is held between the first and second annular plates 42 and 44. Although the example described above is given, it is also possible to use an adhesive to hold the sheet.

(3) In the above embodiment, the second support ring 4
In order to be able to open the sensor mounting scheduled area 47 at 0 by applying an external force, a square ring-shaped groove 48 is formed. However, as shown in FIG. May be provided with a through hole 48a. Further, although not shown, the groove 48 may be perforated or a slit leaving only one place. In these cases, the external force applied when opening the sensor attachment scheduled area 47 can be reduced, and the attachment work of the sensor 20 can be performed more easily. Even when the through-hole 48a is provided, if the opening size is reduced, the invasion of moisture can be prevented.

(4) In the above embodiment, the second support ring 4
In the case where the sensor 20 is mounted on the second support ring 40, the sensor mounting area 47 in the second support ring 40 is completely separated as a fragment 47a. It can be left connected to the two supporting rings 40. For example, as shown in FIG. 6 and FIG.
It may be formed in a U-shape. In this way, if only the sensor mounting area 47 is cut and raised and kept connected to the second support ring 40, the falling place of the debris 47a separated from the sensor mounting area 47 as in the above-described embodiment does not interfere. This eliminates the restriction of specifying a part that does not exist.

(5) In the above embodiment, the second support ring 4
Although the sensor 20 is mounted in the radial direction with respect to the sensor 0, the sensor 20 may be mounted in the axial direction (not shown).

(6) In the above embodiment, an example is described in which the sensor 20 is made to face the pulsar ring 10 in the axial direction. However, although not shown, the sensor 20 is made to face in the radial direction. Is also good. In this case, both the pulsar ring 10 and the first support ring 30 are formed in a cylindrical shape,
The pulsar ring 10 needs to be adhered to the outer peripheral surface of the first support ring 30, and the sensor surface of the sensor 20 needs to be positioned radially downward.

(7) In the above embodiment, the pulsaring 1
0 is attached to the first support ring 30 and attached to a use target site. For example, as shown in the embodiment shown in FIG. 8, a sealing device in which a seal member 51 and a slinger 52 are combined with a bearing device 5. In the case of mounting the device 50,
The slinger 52 can be used as a substitute for the first support ring 30. In this case, the first support ring 30 can be made unnecessary, which can contribute to cost reduction.

(8) In the above embodiment, an example is described in which the rotational speed detecting device 6 is used for the hub unit 1 for the drive axle of an automobile. Can be used. In other words, although no specific examples are given, in short, the rotation speed detection device 6 of the present invention is configured such that the rotation speed of the rotating member of the cylindrical body and the shaft body that are concentrically arranged so as to be relatively rotatable, such as an industrial machine. Can be used where needed to be detected.

(9) In the above embodiment, a Hall element is used as the sensor 20, but a magnetoresistive element can be used.

[0052]

According to the rotation speed detecting device of the present invention, when the sensor breaks down with use, the code line of the sensor is cut and left without being removed from the support ring. In this case, it is possible to perform repair by opening another sensor mounting area in the support ring and mounting a new sensor. As described above, the repair work is extremely simple, and the work can be performed easily and quickly. As described above, since the repair work related to the sensor failure is simplified, even if the rotation speed detecting device according to the present invention is used in a narrow area, it can be performed without any trouble, which is advantageous.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing a rotation speed detecting device according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a main part of a second support ring in FIG. 1;

FIG. 3 is an explanatory view showing an operation of attaching a sensor to a second support ring.

FIG. 4 is a longitudinal sectional view showing a hub unit equipped with the rotation speed detecting device of FIG. 1;

FIG. 5 shows another example of the second support ring and corresponds to FIG.

FIG. 6 is a diagram corresponding to FIG. 2, according to still another example of the second support ring.

FIG. 7 is a plan view of the second support ring of FIG. 6;

FIG. 8 is a partially enlarged cross-sectional view showing an example in which the pulsar ring of the rotation speed detecting device of the present invention is attached to a sealing device.

[Explanation of symbols]

 Reference Signs List 1 hub unit 2 drive axle 3 axle case 4 hub unit hub wheel 5 hub unit bearing device 6 rotation speed detection device 10 rotation speed detection device pulser ring 20 rotation speed detection device sensor 21 sensor code line 40 second support ring Body 47 Sensor mounting area of second support ring 48 Groove of second support ring 49 Sensor pocket of second support ring

Claims (4)

[Claims] 1. A rotation speed detecting device for detecting a rotation speed of a member on a rotating side of a cylindrical body and a shaft body concentrically arranged so as to be relatively rotatable, wherein the pulsar ring is attached to the rotating side member. And a sensor attached to the non-rotating side member in a state of non-contact and opposing to a required position in the circumferential direction of the pulsar ring and detecting a change in a relative position due to rotation of the pulsar ring, a sensor for the non-rotating side member Is mounted via a supporting ring attached to the non-rotating side member in a state of non-contacting opposition to the pulsar ring. At least two circumferential positions of the supporting ring are related to sensor mounting. A rotational speed detecting device, wherein a sensor mounting area which is opened by application of an external force is provided. 2. The rotation speed detecting device according to claim 1, wherein the support ring has at least a cylindrical portion concentric with the axis of the rotating member, and the sensor mounting area is provided in the cylindrical portion. And a rotation speed detecting device. 3. The rotation speed detecting device according to claim 1, wherein a groove or a slit is provided in a contour portion of the sensor mounting scheduled area. 4. The rotation speed detecting device according to claim 1, wherein the pulsar ring is provided with magnetic poles having different polarities alternately in a circumferential direction, and the sensor is configured to detect a relative rotation caused by rotation of the pulsar ring. A rotation speed detecting device for detecting a change in a magnetic field according to a change in position.