JPH0829205A - Part fixing device - Google Patents

Abstract

PURPOSE:To prevent uneven collapse of an O-ring and resultant incomplete seal due to misalignment of a cylindrical part of unit part against a fixing hole. CONSTITUTION:In a part of circumferential surface of a cylindrical part 1 of a unit part 3 whereto a screw is fastened against the axis connecting the position for fixing a screw part 6 of a flange 2 and the center of a cylindrical part, a projection 9 is provided. The projection 9 crosses perpendicularly to the axis passing the position for fixing a screw part 6 of a flange 2 and the center of a cylindrical part and is formed in the vicinity of the axis passing the center of the cylindrical part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mounting structure for a member mounting device in which a cylindrical member is mounted in a mounting hole, and more particularly to a seal for a mounting portion.

[0002]

2. Description of the Related Art For example, a mounting structure technology for a speed sensor for an automobile is disclosed in Japanese Utility Model Publication No. 5-45976. This prior art speed sensor has a cylindrical sensor body and a mounting flange portion,
The sensor body is fitted in a mounting hole formed in the support member (knuckle arm), and the flange portion is fixed to the support member with a screw. In a general speed sensor, an O-ring is attached to the outer circumference of the sensor body and the gap between the sensor body and the mounting hole is sealed to prevent corrosion and rust inside the sensor body and support members. However, in Japanese Utility Model Publication No. 5-45976, a cylindrical shim is attached to the outer circumference of the sensor, and a ring-shaped protrusion is formed along the peripheral surface of the shim to position the center of the sensor. It is possible to easily remove the sensor even if the shim corrodes.

[0003]

By the way, when fixing a cylindrical unit member to a support member as seen in the case of fixing the above-described sensor device to the support member, the number of parts is reduced and In order to simplify the assembling work, the flange portion of the unit member and the support member are
It is desirable to fix with one screw. Further, in order to facilitate the assembling work, it is desirable that the diameter of the tubular portion of the unit member is made slightly smaller than the diameter of the mounting hole of the support member, and a gap is formed between them. However, if a single screw is tightened to fix the flange portion, the tightening torque may cause the tubular portion of the unit member to be positioned and fixed while being offset to one of the peripheral walls of the mounting hole of the support member. There is. On the outer circumference of the tubular part of the unit member,
An O-ring made of rubber or the like is mounted for the seal, and the O-ring is arranged in the gap between the outer periphery of the cylindrical portion of the unit member and the mounting hole of the support member. If the portion is positioned in a state of being offset with respect to the mounting hole of the support member, the crushed condition of the O-ring becomes uneven. That is, the crushed amount of the O-ring is large in the portion where the gap between the tubular portion of the unit member and the mounting hole of the support member is small, and the crushed amount of the O-ring is small in the portion where the gap is large.
The function of the seal may be incomplete in the portion where the amount of collapse of the O-ring is small. In order to make a reliable seal, it is necessary to dispose the tubular portion of the unit member in the center of the mounting hole of the support member, but it is difficult to perform such positioning work. Further, if the gap is made small, it becomes difficult to insert and remove the unit member into and from the mounting hole of the support member.

Therefore, it is an object of the present invention to secure the seal at the mounting portion and to simplify the mounting work when the member is mounted in the mounting hole.

[0005]

In order to solve the above-mentioned problems, according to the present invention, it is held in a casing having a cylindrical portion (1) and a flange portion (2) larger than the diameter of the cylindrical portion. Unit member (3), a supporting member (5) in which a mounting hole (4) having a diameter slightly larger than the cylindrical portion of the unit member, and a flange portion of the unit member In a member attaching device including a single screw member (6) fixed at a predetermined position above, and a ring-shaped seal member (7) installed on a cylindrical portion of the unit member and made of an elastic body. : With respect to an axis (8) connecting the position of fixing the screw member of the flange portion and the center of the cylindrical portion on the peripheral surface of the cylindrical portion of the unit member or the inner peripheral surface of the mounting hole. , Of the surface located in the direction of tightening the screw member Projections formed on the portion (9); the provision.

The symbols shown in parentheses are reference numerals of corresponding elements in the embodiments described later, but each constituent element of the present invention is a specific element in the embodiments. It is not limited to only.

[0007]

In the present invention, the screw is attached to the shaft (8) connecting the position of fixing the screw member of the flange portion and the center of the cylindrical portion on the peripheral surface of the cylindrical portion of the unit member. A protrusion (9) is formed on a part of the surface located in the direction of tightening the member. When the screw member is tightened to fix the flange portion onto the support member, the tightening torque causes the cylindrical portion to move in the direction of the force.
However, since the protrusion (9) exists on the outer peripheral surface of the cylindrical portion in the moving direction, the protrusion (9) abuts the inner peripheral surface of the mounting hole (4) of the support member, and the cylindrical portion Prevent the movement of. Therefore, the unit member can be positioned and fixed without eccentricity of the cylindrical portion with respect to the position of the mounting hole (4) of the support member. Further, since the protrusion (9) is formed only on the surface of the cylindrical portion of the unit member that is located in the direction in which the screw member is tightened with respect to the shaft (8), the surface in the opposite direction. A gap is formed between and the peripheral wall of the mounting hole of the support member. That is, even if the protrusion (9) is included, the size of the cylindrical portion of the unit member is slightly smaller than the mounting hole (4) of the supporting member.
It is easy to insert and remove the cylindrical part from and to.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings. FIG. 1 schematically shows the appearance of a sensor unit 3 which is a unit member in the present embodiment and a mounting plate 5 on which the sensor unit 3 is mounted, and FIG. 2 is a vertical cross-sectional view of the sensor unit 3 fixed to the mounting plate 5. 3 is a sectional view taken along line III-III of FIG.
4 is an enlarged view of a part of FIG. 3, and FIG. 5 is an enlarged vertical sectional view of a part of FIG. The description of the internal structure of the sensor unit 3 is omitted.

The sensor unit 3 of this embodiment is a speed sensor used to detect the rotational speed of the wheels of an automobile, and is fixed to a mounting plate 5 arranged near the wheels. Therefore, it is inevitable that the exposed portion of the sensor unit 3 gets wet or dirty due to splashing of rainwater, muddy water, or the like from the road surface. However, if water enters the electric circuit inside the sensor unit 3 or the electric circuit of another unit, there is a risk of causing malfunction of the electric circuit due to rusting or corrosion, so that water does not enter the electric circuit portion. It is necessary to surely seal.

In this embodiment, a mounting hole 4 and a screw hole 11 which are circular through holes are formed in the mounting plate 5, and a hole 2a is formed in the flange portion 2 of the sensor unit 3. Therefore, the cylindrical portion 1 of the sensor unit 3 is attached to the mounting hole 4
, The flange portion 2 of the sensor unit 3 is arranged so as to abut the mounting plate 5, the hole 2a of the flange portion 2 and the screw hole 11 are aligned, and the bolt 6 is attached to this portion. As shown in FIG. 2, the sensor unit 3 can be fixed to the mounting plate 5.

In the case of such a mounting structure, it is necessary to surely seal the gap between the mounting hole 4 of the mounting plate 5 and the cylindrical portion 1 of the sensor unit 3. In order to easily insert or remove the cylindrical portion 1 into or from the mounting hole 4, it is essential to make the diameter of the cylindrical portion 1 a little smaller than the diameter of the mounting hole 4 to provide a gap. Must be sealed.

In this embodiment, a rubber O-ring 7 is attached to the groove 1a provided in the cylindrical portion 1 of the sensor unit 3, and the O-ring 7 is used to attach the outer periphery of the cylindrical portion 1 to the mounting hole 4.
It is configured to seal the gap between and.

By the way, in this example, since the sensor unit 3 is fixed to the mounting plate 5 by tightening one place of the flange portion 2 with the bolt 6, when tightening with the bolt 6, the force in the tightening direction is applied to the sensor. Join unit 3. That is, a clockwise torque is applied to the center of the bolt 6, and the cylindrical portion 1 of the sensor unit 3 is attached to the mounting hole 4
Of the position (1) to one side (shifted to the lower side of the shaft 8 in FIG. 3). If the sensor unit 3 is fixed in a state where the cylindrical portion 1 is displaced from the mounting hole 4, the cylindrical portion 1 may be different due to the difference in the circumferential position.
Since the gap between the mounting hole 4 and the wall surface of the mounting hole 4 changes, the crushing condition of the O-ring 7 arranged in the gap also varies depending on the position in the circumferential direction. When the crushing condition of the O-ring 7 is not uniform, the O-ring 7 and the cylindrical portion 1 and the O-ring 7 and the mounting hole 4
There is a possibility that a portion having insufficient contact with the wall surface of the sheet will be formed, which will easily cause a seal failure.

In order to prevent such a seal failure, in this embodiment, the cylindrical portion 1 is devised so as not to shift with respect to the position of the mounting hole 4. That is, the cylindrical portion 1
A protrusion 9 is formed on a part of the peripheral surface of the. The position where the projection 9 is formed is on an axis 12 which is orthogonal to the axis 8 connecting the center of the hole 2a and the center of the mounting hole 4 and passes through the center of the mounting hole 4,
It is a position in the direction in which the bolt 6 is tightened with respect to the shaft 8.
Although it is at the same position, the protrusion 9 may be formed in the vicinity of the circumference passing through the center of the hole 2a and the center of the mounting hole 4. In addition, in this embodiment, the surface of the projection 9 is formed along the peripheral surface of the mounting hole 4, and the width of the projection 9 in the circumferential direction is
The angle θ viewed from the center of the mounting hole 4 is about 40 degrees. Further, the radial thickness of the projection 9 is formed so as to match the difference between the radius of the mounting hole 4 and the radius of the cylindrical portion 1. The dimensions of each member in this embodiment are as follows.

Outer diameter of the cylindrical portion 1 is 24.85 [mm] Diameter of mounting hole 4 is 25 [mm] Thickness of protrusion 9 is 0.075 [mm] Outer diameter of O-ring 7 is 25.7 [mm] (Uncrushed state) When the sensor unit 3 is attached, the cylindrical portion 1 is attached to the mounting plate 5 by the arrow A by the tightening torque of the bolt 6.
Although it tries to move in one direction, a projection 9 is formed on the surface of the cylindrical portion 1 in the A1 direction, and the projection 9 has a wall surface of the mounting hole 4 with the cylindrical portion 1 positioned in the center of the mounting hole 4. The contact of the cylindrical portion 1 is reliably prevented by the protrusion 9. That is, the cylindrical portion 1 is fixed by tightening the bolt 6 while being positioned in the center of the mounting hole 4. Since eccentricity does not occur in the mounting position of the cylindrical portion 1, the gap between the cylindrical portion 1 and the wall surface of the mounting hole 4 becomes uniform, and the crushing condition of the O-ring 7 arranged in this gap is all in the circumferential direction. It becomes even at the position. Therefore, the O-ring 7 and the cylindrical portion 1 and O
The state of close contact between the ring 7 and the wall surface of the mounting hole 4 is improved,
As a result, a reliable seal is realized.

The protrusion 9 is formed only on a part of the peripheral surface of the cylindrical portion 1, and the thickness of the protrusion 9 is half the difference between the diameter of the mounting hole 4 and the diameter of the cylindrical portion 1. So the protrusion 9
The size of the cylindrical portion 1 including is smaller than that of the mounting hole 4, so that the cylindrical portion 1 can be easily inserted into and removed from the mounting hole 4. Although the outer shape of the cylindrical portion 1 including the mounted O-ring 7 is larger than the diameter of the mounting hole 4, the O-ring 7 is made of rubber and has a smaller diameter when crushed by elastic deformation. The mounted cylindrical portion 1 can be inserted into the mounting hole 4.

In this example, the sensor unit 3 case
Thing is made of nylon resin. Inside the casing of the sensor unit 3, an electric circuit for detecting magnetism in the vicinity of the lower end surface 1b and outputting an electric signal according to a magnetic change is provided. An electric cable 13 connected to the electric circuit is drawn out from the vicinity of the upper end surface of the sensor unit 3.

[0018]

As described above, according to the present invention, of the peripheral surface of the cylindrical portion of the unit member, with respect to the axis (8) connecting the position for fixing the screw member of the flange portion and the center of the cylindrical portion. Since the protrusion (9) is formed on a part of the surface located in the tightening direction of the screw member, even if the cylindrical portion is moved due to the tightening torque of the screw member, the protrusion (9) does not fit into the mounting hole of the support member. It abuts the inner peripheral surface of (4) and prevents the cylindrical portion from moving. Therefore, the unit member can be positioned and fixed without eccentricity of the cylindrical portion with respect to the position of the mounting hole (4) of the support member. Further, since the protrusion (9) is formed only on the surface of the cylindrical portion of the unit member that is located in the direction in which the screw member is tightened with respect to the shaft (8), the surface in the opposite direction. A gap is formed between and the peripheral wall of the mounting hole of the support member.
That is, since the size of the cylindrical portion of the unit member is a little smaller than the mounting hole (4) of the supporting member even if the protrusion (9) is included, the cylindrical portion is not inserted into or removed from the mounting hole (4). It's easy.

[Brief description of drawings]

FIG. 1 is a perspective view showing appearances of a sensor unit 3 and a mounting plate 5 on which the sensor unit 3 is mounted.

FIG. 2 is a vertical sectional view showing a state where the sensor unit 3 is fixed to a mounting plate 5.

3 is a sectional view taken along line III-III in FIG.

FIG. 4 is an enlarged view of a portion of FIG.

5 is an enlarged vertical sectional view of a part of FIG. 2. FIG.

[Explanation of symbols]

 1: Cylindrical part 1a: Groove 2: Flange part 2a: Hole 3: Sensor unit 4: Mounting hole 5: Mounting plate 6: Bolt 7: O-ring 8, 12: Shaft 9: Protrusion 11: Screw hole 13: Electric cable -Bull A1: Arrow

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Katsu Shirai Kaika 2-chome, Asahi-machi, Kariya city, Aichi Aisin Seiki Co., Ltd. (72) Inventor Yoshiyoshi Tanaka 1-chome, Toyota-cho, Aichi prefecture Toyota Automobile Co., Ltd.

Claims (1)

[Claims] 1. A unit member held in a casing having a cylindrical portion and a flange portion larger than the diameter of the cylindrical portion, and a mounting hole having a diameter slightly larger than the cylindrical portion of the unit member. A formed support member, a single screw member for fixing one place of the flange portion of the unit member to a predetermined position on the support member, and a ring installed in the cylindrical portion of the unit member and made of an elastic body. In a member mounting device including a cylindrical seal member, the cylindrical surface of the unit member and the cylindrical portion of the inner peripheral surface of the mounting hole to which the screw member is fixed. A member mounting device comprising: a projection formed on a part of a surface located in a direction in which the screw member is tightened, with respect to an axis connecting the center of the portion.