JP2006162014A - Sealing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sealing device 1 equipped with a sensor function for detecting an oscillating angle and rotation speed of a shaft 3 in addition to a sealing function for sealing a gap between a housing 2 and a shaft 3. <P>SOLUTION: A sealing device 1 for sealing a gap between a housing 2 and a shaft 3 passing through the shaft hole 2a of the housing 2 is equipped with a shaft operation detector 5 for detecting an oscillating angle and rotation speed of the shaft 3. The shaft operation detector 5 is provided with a magnetic encoder 6 mounted in one of the sealing device 1 and the shaft 3, and a magnetic sensor 7 mounted in the other and detecting magnetism of the magnetic encoder 6 as detection elements. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a sealing device according to a sealing technique, and more specifically, a seal portion (sealing device main body) for sealing between a housing and a shaft, and a sensor portion (shaft operation) for detecting a swing angle or a rotational speed of the shaft. It is related with the sealing device which consists of a combination with a detection part. The sealing device of the present invention is used, for example, as a steering dust seal in a vehicle such as an automobile, or in addition, it is necessary to detect the rotation angle at a position where the swinging motion is required or at a position where the rotational motion is required. Used for parts.

  Conventionally, a steering dust seal 51 shown in FIG. 5 is known, and this dust seal 51 is attached to an inner periphery of a shaft hole 52a of a housing (front dash panel) 52, a bellows portion 54, and a damper portion 55. And a seal lip portion 57 that is slidably in close contact with the peripheral surface of the shaft (steering shaft) 56 (see Patent Document 1 or 2).

  When the shaft 56 is decentered in the left-right direction in the drawing, the dust seal 51 moves along with the annular damper portion 55 disposed on the outer periphery thereof, and the bellows portion 54 is elastically deformed along with this, and the seal lip portion 57. Is kept in close contact with the peripheral surface of the shaft 56 over the entire circumference, so that it is possible to exhibit excellent sealing performance. The dust seal 51 detects the swing angle of the shaft 56. No sensor function is provided.

  Therefore, according to the above prior art, when it is necessary to detect the swing angle of the shaft 56, a sensor mechanism must be separately provided in addition to the dust seal 51. Therefore, the structure is complicated, the number of parts and This causes inconveniences such as an increase in cost.

JP-A-9-112704 Japanese Patent Laid-Open No. 9-159031

  In view of the above, an object of the present invention is to provide a sealing device having a sensor function for detecting a swing angle or a rotational speed of a shaft in addition to a sealing function for sealing between a housing and a shaft. .

  In order to achieve the above object, a sealing device according to claim 1 of the present invention is a sealing device for sealing between a housing and a shaft inserted through a shaft hole of the housing, wherein the swing angle or the number of rotations of the shaft. The shaft operation detection unit detects, as a detection element, a magnetic encoder attached to one of the sealing device and the shaft, and a magnetic encoder attached to the other and the magnetism of the magnetic encoder. And a magnetic sensor for detection.

  According to a second aspect of the present invention, there is provided a sealing device according to the first aspect, wherein the sealing device has a bellows portion that is elastically deformed in accordance with the eccentricity of the shaft, and one detection element is provided by the bellows portion. It is characterized by holding.

  According to a third aspect of the present invention, there is provided the sealing device according to the first aspect, wherein the sealing device has a damper portion that moves according to the eccentricity of the shaft, and the damper portion causes one of the detection elements to move. It is characterized by holding.

  According to a fourth aspect of the present invention, there is provided a sealing device according to the first, second or third aspect, wherein the sealing device integrally includes a mounting portion, a bellows portion, a damper portion and a seal lip portion. A main body and a detection element holding portion for holding one detection element, the detection element holding portion being fixed to an inner peripheral side of the mounting portion of the steering dust seal main body, a bellows portion And a damper part, and one of the detection elements is held by the damper part in the detection element holding part.

  Furthermore, the sealing device according to claim 5 of the present invention is the sealing device according to claim 4, further comprising an axial displacement suppression means for suppressing the axial displacement of the damper portion of the detection element holding portion with respect to the shaft. It is characterized by having.

  In the sealing device according to claim 1 of the present invention having the above-described configuration, a shaft operation detection unit that detects the swing angle or the number of rotations of the shaft is provided, and the shaft operation detection unit is used as a detection element thereof. Because it has a magnetic encoder attached to one of the shafts and a magnetic sensor that is attached to the other and detects the magnetism of the magnetic encoder, the latter magnetic sensor detects the magnetism of the former magnetic encoder. By doing so, it becomes possible to detect the swing angle or the rotational speed of the shaft.

  The magnetic encoder is a magnetic body with multiple magnetic poles so that the north and south poles of the magnet are alternately arranged on the circumference, and the pulse signal is read by the magnetic sensor at the time of relative oscillation or rotation. It is used for detecting the swing angle and the rotational speed. A magnetic encoder is generally one in which a magnetic powder such as ferrite is kneaded into a rubber-like elastic body and magnetized to form a large number of magnetic poles. On the other hand, the magnetic sensor is generally provided at one place on the circumference so as to face the magnetic encoder, and is connected to the control unit through wiring or the like. The sensor mechanism itself comprising a combination of the magnetic encoder and the magnetic sensor is a conventionally known technique.

  When the shaft operation detector is provided in the sealing device as described above, when the shaft may be greatly decentered, the detection element attached to the shaft moves in the radial direction together with the shaft. There is a concern that the distance between them changes, and this causes a decrease in magnetic force, magnetic disturbance, and the like, which makes it difficult to stably supply magnetism.

  Therefore, in the sealing device according to claim 2 of the present invention, one detection element is held by a bellows portion that is elastically deformed in accordance with the eccentricity of the shaft, and thereby, the one detection element follows the eccentricity of the shaft. did. When the sealing device has a damper portion that moves according to the eccentricity of the shaft, one of the detection elements may be held by the damper portion.

  In addition, when the sealing device is a steering dust seal that integrally includes a mounting portion, a bellows portion, a damper portion, and a seal lip portion, a detection element holding portion is provided in addition to these components, and the holding portion holds In this case, the steering dust seal takes charge of the sealing function, and the detection element holding portion holds one of the detection elements and takes charge of the sensor function. The detection element holding part preferably has a unique mounting part, bellows part and damper part. By holding one detection element by this damper part, one detection element is made to follow the eccentricity of the shaft. (Claim 4).

  In addition, when an axial displacement suppression unit that suppresses axial displacement of the damper portion in the detection element holding portion with respect to the shaft is provided, the one detection element held in the damper portion is attached to the other side of the shaft. It is possible to prevent the detection element from being displaced in the axial direction and becoming unable to detect the magnetism.

  The present invention has the following effects.

  That is, in the sealing device according to the first aspect of the present invention, a shaft operation detection unit for detecting the swing angle or the rotation speed of the shaft is provided, and this shaft operation detection unit serves as a detection element of either the sealing device or the shaft. Since it has a magnetic encoder attached to one and a magnetic sensor attached to the other and detecting the magnetism of the magnetic encoder, the latter magnetic sensor detects the magnetism of the former magnetic encoder, It is possible to detect the swing angle or the number of rotations. Therefore, in addition to the basic sealing function as the sealing device, it is possible to provide a sealing device having a sensor function for detecting the swing angle or rotational speed of the shaft. Further, as compared with the case where the seal portion and the sensor portion are provided separately, the structure can be simplified and the number of parts and the cost can be reduced.

  Further, in the sealing device according to claim 2 or 3 of the present invention, one detection element is held by the bellows portion that is elastically deformed according to the eccentricity of the shaft or the damper portion that follows the eccentricity of the shaft. In addition, one detection element can be made to follow the eccentricity of the shaft. Therefore, it is possible to suppress the occurrence of a decrease in magnetic force or magnetic disturbance due to a change in the distance between the magnetic sensor and the magnetic encoder, thereby providing a sealing device that exhibits a stable sensor function.

  Further, in the sealing device according to claim 4 of the present invention, even when the sealing device is a steering dust seal, the function and effect of the first, second or third aspect can be obtained. Therefore, in addition to the basic dust seal function as a steering dust seal, it is possible to provide a steering dust seal with a sensor function that detects the swing angle of the steering shaft and the like, and a steering dust seal that exhibits a stable sensor function. Can be provided.

  Furthermore, in the sealing device according to claim 5 of the present invention, since the damper part in the detection element holding part is provided with the axial displacement suppressing means for suppressing the axial displacement with respect to the shaft, the damper part is provided. It is possible to prevent one detection element held in the direction of the axial displacement with respect to the other detection element attached to the shaft side so that magnetic detection is impossible. Therefore, also from this point, it is possible to provide a steering dust seal that exhibits a stable sensor function.

  The present invention includes the following embodiments.

(1) A steering angle can be detected by a combination of a seal of a portion that performs a swinging motion and a magnetic rubber having multiple magnetic poles. Moreover, since the detection result can be processed with a digital signal, it can be detected even when there is no rotation. Since the member to be magnetized is a rubber material, it can be molded into various shapes.

(2) The steering angle can be detected by combining a multi-pole rubber with the steering dust seal. Since the shaft is highly eccentric, a bellows is added so that the sensor always keeps a certain distance from the magnetic rubber, and a magnetic rubber is attached to the tip (so that the magnetic rubber follows the eccentricity of the shaft). A damper is provided so that the sensor always keeps a certain distance from the magnetic rubber.

(3) The steering angle can be controlled by combining the steering dust seal with a rubber material having multiple magnetic poles. In addition, by combining magnetic rubber with the seal, the seal part and the sensor part can be integrated, so that simplification of the structure (reducing space), reduction in the number of parts and cost can be expected. Also, by adding a bellows and attaching a magnetic rubber to the tip of the bellows, the magnetic rubber and the sensor can maintain a certain distance, and a stable supply of magnetism becomes possible.

  Next, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows a half-cut section of a sealing device 1 according to an embodiment of the present invention. The sealing device 1 according to the embodiment is used as a vehicle steering dust seal and is configured as follows.

  That is, first, a rubber-like elastic material that seals a gap between a peripheral surface of a shaft hole 2a provided in the front dash panel 2 that is a housing and a peripheral surface of a steering shaft 3 that is a shaft inserted through the shaft hole 2a. A steering dust seal body 4 is provided, and a shaft operation detector 5 for detecting the swing angle of the steering shaft 3 is combined with the steering dust seal body 4.

  The shaft operation detector 5 includes, as detection elements, a magnetic encoder 6 attached to the peripheral surface of the steering shaft 3 and a magnetic sensor 7 attached to the steering dust seal body 4 side. A detection element holding portion 8 for holding the sensor 7 is assembled to the steering dust seal body 4. The arrangement of the magnetic encoder 6 and the magnetic sensor 7 may be reversed, that is, the magnetic encoder 6 may be attached to the steering dust seal body 4 side and the magnetic sensor 7 may be attached to the steering shaft 3 side.

  The steering dust seal main body 4 includes a cylindrical attachment portion 9 with a flange 9a fitted to the inner periphery of the shaft hole 2a of the front dash panel 2, an annular bellows portion 10 integrally formed on the inner periphery thereof, An annular damper portion 11 integrally formed on the peripheral side and an annular seal lip portion 12 integrally formed on one axial end thereof and slidably in close contact with the peripheral surface of the steering shaft 3 are integrally provided. Metal mounting rings 13 and 14 are embedded in the mounting portion 9 and the damper portion 11, respectively.

  The detection element holding portion 8 includes an annular attachment portion 15 fitted on the inner peripheral side of the attachment portion 9 of the steering dust seal body 4, an annular bellows portion 16 integrally formed on the inner peripheral side, and an inner periphery thereof. An annular damper portion 17 integrally formed on the side is integrally provided, and a metal reinforcing ring 18 is embedded in the attachment portion 15.

  In addition, a concave portion 19 for holding the magnetic sensor 7 is provided at the tip end portion in the axial direction of the damper portion 17 so as to open in one place on the circumference and radially inward. A magnetic sensor 7 is attached in 19 toward the inside in the radial direction. The recess 19 may be formed in an annular shape.

  On the other hand, an annular recess 20 is provided on the peripheral surface of the steering shaft 3 so as to face the magnetic sensor 7, and the magnetic encoder 6 is attached in the annular recess 20.

  As shown in FIG. 2, the magnetic encoder 6 is an annular body, and is multi-pole so that the N pole 21 and the S pole 22 of the magnet are alternately arranged on the circumference. By reading the pulse signal, it is used for detecting the swing angle of the steering shaft 3 or the like. The magnetic encoder 6 is generally formed by kneading and magnetizing magnetic powder such as ferrite in a rubber-like elastic body, and has flexibility, so that a cut portion 23 is provided at one place on the circumference. Thus, the steering shaft 3 can be hugged and attached.

  The magnetic encoder 6 and the magnetic sensor 7 are combined with each other to form a sensor unit for detecting the swing angle of the steering shaft 3. When the magnetic encoder 6 swings together with the steering shaft 3, the pulse signal is transmitted. The swing angle is detected by reading the magnetic sensor 7. For detection, a backup device such as a sensor control unit is separately used.

  According to the sealing device 1 having the above configuration, the steering dust seal body 4 performs a basic dust seal function, and the shaft operation detection unit 5 including a combination of the magnetic encoder 6 and the magnetic sensor 7 detects the swing angle of the steering shaft 3. Since the sensor function is achieved, the sealing device 1 having a sensor function for detecting the swing angle of the steering shaft 3 as well as a basic sealing function can be provided as intended.

  Further, as compared with the case where the seal part and the sensor part are provided separately, the structure can be simplified, and the number of parts and the cost can be reduced.

  Further, according to the sealing device 1 having the above-described configuration, the magnetic sensor 7 is held by the damper portion 17 that follows the eccentricity of the steering shaft 3, so that the magnetic sensor 7 can follow the eccentricity of the steering shaft 3. Is possible. Therefore, it is possible to prevent the magnetic force from being reduced or the magnetism from being disturbed by the distance between the magnetic sensor 7 and the magnetic encoder 6 being changed, and thus the sealing device 1 that exhibits a stable sensor function. Can be provided.

  In the above embodiment, the magnetic sensor 7 is held by the damper portion 17 of the detection element holding portion 8. However, if a holding portion in place of the damper portion 17 is provided at the inner peripheral end of the bellows portion 16. Even without the damper portion 17, the magnetic sensor 7 can be held by the bellows portion 163.

  In the above embodiment, since the bellows portion 16 is thin and flexible, if the damper portion 17 supported by the bellows portion 16 is displaced in the axial direction with respect to the steering shaft 3, the magnetic sensor There is a concern that 7 will not face the magnetic encoder 6, thereby hindering the sensor function. Therefore, in order to prevent this, it is preferable to provide the axial displacement suppression means 24 that suppresses the damper portion 17 from being axially displaced with respect to the steering shaft 3, and an embodiment thereof will be described below.

  That is, first, in the example of FIG. 3, two metal retaining rings 25 and 26 having an L-shaped cross section are combined to form an annular groove-like space 27 inside thereof, and outward in the radial direction. The magnetic encoder 6 is mounted in the open space 27, and a damper portion 17 holding the magnetic sensor 7 is housed in a relatively rotatable manner.

  One holding ring 25 has a cylindrical portion 25a fitted to the peripheral surface of the steering shaft 3, and a flange portion 25b is integrally formed radially outward at one axial end of the cylindrical portion 25a. Molded. The other holding ring 26 has a cylindrical portion 26a fitted to the outer peripheral side of the cylindrical portion 25a of the one holding ring 25, and radially outward at the other axial end of the cylindrical portion 26a. The flange portion 26b is integrally formed toward the front. Therefore, the space between the flange portions 25b, 26b of the holding rings 25, 26 is defined as the space 27, the magnetic encoder 6 is attached to the outer peripheral side of the cylindrical portion 26a of the other holding ring 26, and the space 27 On the other hand, the inner peripheral part of the damper part 17 is inserted from the outer peripheral side.

  A slight axial gap is set between the pair of upper and lower flange portions 25b, 26b and the damper portion 17, so that the damper portion 17 can be displaced between the flange portions 25b, 26b. Larger displacement than that is limited because the damper portion 17 abuts on any of the flange portions 25b and 26b. Therefore, the damper portion 17 is prevented from being greatly displaced in the axial direction with respect to the steering shaft 3, so that the magnetic sensor 7 always faces the magnetic encoder 6.

  Further, in the example of FIG. 4, one metal holding ring 28 is fitted to the outer periphery of the steering shaft 3, and the magnetic encoder 6 is attached to the inner peripheral side, and the damper portion 17 is attached to the holding ring. Axial displacement suppression means 24 is configured by the contact.

  The holding ring 28 has a small-diameter cylindrical portion 28a fitted to the peripheral surface of the steering shaft 3, and a large-diameter cylindrical portion 28c is connected to the cylindrical portion 28a via a step portion 28b. It is integrally molded. Since a radial space is formed on the inner peripheral side of the large-diameter cylindrical portion 28c with the peripheral surface of the steering shaft 3, this space is used as a mounting space for the magnetic encoder 6, and the large-diameter cylindrical portion 28c. A magnetic encoder 6 is attached to the inner peripheral surface of the.

  Further, the damper ring 17 can be brought into contact with the holding ring 28 from the lower side in the figure with respect to the tip end portion of the large-diameter cylindrical portion 28c. 3 is restrained from being displaced in one axial direction (A direction in the figure). Therefore, according to this example, the displacement of the damper portion 17 in the axial direction with respect to the steering shaft 3 is suppressed, although only the displacement in one axial direction is limited. According to this example, the magnetic sensor 7 detects magnetism in such a manner that the magnetism of the magnetic encoder 6 passes through the holding ring 28.

Sectional drawing which shows the mounting state of the sealing device based on the Example of this invention Single item perspective view of magnetic encoder Sectional drawing which shows the example of an axial direction displacement suppression means Sectional drawing which shows the other example of an axial direction displacement suppression means Half-cut sectional view showing a sealing device according to a conventional example

Explanation of symbols

1 Sealing device 2 Front dash panel (housing)
2a Shaft hole 3 Steering shaft (shaft)
4 Steering dust seal body 5 Axis operation detector 6 Magnetic encoder (detection element)
7 Magnetic sensor (detection element)
8 Detection element holding part 9, 15 Mounting part 9a Flange 10, 16 Bellow part 11, 17 Damper part 12 Seal lip part 13, 14, 18 Reinforcement ring 19 Recessed part 20 Annular recessed part 21 N pole 22 S pole 23 Cut part 24 Axial direction Displacement suppression means 25, 26, 28 Retaining ring 25a, 26a, 28a, 28c Cylindrical part 25b, 26b Flange part 27 Space 28b Step part

Claims (5)

A sealing device (1) for sealing between a housing (2) and a shaft (3) inserted through a shaft hole (2a) of the housing (2),
A shaft operation detector (5) for detecting a swing angle or a rotational speed of the shaft (3);
The shaft operation detector (5) has, as its detection element, a magnetic encoder (6) attached to one of the sealing device (1) and the shaft (3), and the magnetic encoder (6) attached to the other. And a magnetic sensor (7) for detecting magnetism. The sealing device of claim 1.
The sealing device (1) has a bellows (16) that is elastically deformed according to the eccentricity of the shaft (3), and holds one detection element (7) by the bellows (16). Sealing device. The sealing device of claim 1.
The sealing device (1) has a damper portion (17) that moves in accordance with the eccentricity of the shaft (3), and holds one detection element (7) by the damper portion (17). apparatus. The sealing device according to claim 1, 2 or 3,
The sealing device (1) includes a steering dust seal body (4) integrally including a mounting portion (9), a bellows portion (10), a damper portion (11) and a seal lip portion (12), and one detection element (7 And a detection element holding part (8) for holding
The detection element holding portion (8) includes a unique attachment portion (15), a bellows portion (16), and a damper portion (17) fixed to the inner peripheral side of the attachment portion (9) of the steering dust seal body (4). And have
One sealing element (7) is hold | maintained by the damper part (17) in the said detection element holding part (8), The sealing device characterized by the above-mentioned. The sealing device of claim 4.
A sealing device comprising axial displacement restraining means (24) for restraining the damper portion (17) in the detection element holding portion (8) from being axially displaced with respect to the shaft (3).

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