JPH0444936Y2 - - Google Patents

Description

[Detailed Description of the Invention] <<Industrial Application Field>> The present invention relates to a fastening structure in which an insert is screwed into a hole, and in particular, there is a connection between the flat seat of the hole and the insert. The present invention relates to a fastening structure in which an elastic body for sealing is interposed.

《Prior art and its problems》 Generally, when installing an elastic body such as a diaphragm or a bellophragm, these members are attached to a flat seat such as the bottom of a hole, and an insert body that is screwed into the hole. It may be caught between

However, when the elastic body is brought into direct contact with the flat seat and the insert is screwed in, one side of the elastic body tends to be prevented from rotating due to the frictional force between it and the flat seat. The other side of the elastic body tends to be rotated by the frictional force between it and the inserted body.

Therefore, there is a risk that the elastic body may be torsionally deformed and wrinkled, and if the elastic body is tightened with such wrinkles, the elastic body and the flat seat or the insert body may There was a problem in that a gap was formed between the two, impairing the sealing function.

Therefore, in view of the conventional problems, the present invention is
It is an object of the present invention to provide a fastening structure that can prevent torsional deformation of an elastic body even when the elastic body is tightened by an insert body screwed into a hole.

<<Means for Solving the Problems>> In order to achieve the above object, the present invention interposes an elastic body between the flat seat of the storage hole and the insert body that is screwed into the storage hole. In a fastening structure that tightens the elastic body to the flat seat by screwing the body into the flat seat to create a seal between the flat seat and the insert body,
A slide plate is provided between the elastic body and the flat seat, and is engaged with the insert body in the screwing direction and is fitted in the storage hole so as to be relatively rotatable, and the outer periphery of the slide plate and the storage hole are It is constructed by providing a sealing member between the inner periphery and the inner periphery.

<<Operation>> In the fastening structure of the present invention with the above configuration, when the insert is screwed into the storage hole, the slide plate engaged in the screwing direction of the insert rotates together with the insert. The entirety of the elastic body disposed between the insert and the slide plate rotates with the insert.

Therefore, no torsional deformation occurs in the elastic body, and wrinkles are prevented from forming.

Furthermore, by providing a sealing member between the outer periphery of the slide plate and the inner periphery of the storage hole, the space between the slide plate and the storage hole is sealed to enable relative rotation, and as a result, the plane seat A seal between the insert and the insert will be ensured.

<<Example>> Hereinafter, an example of the present invention will be described in detail based on the drawings.

In explaining this embodiment, a clogging alarm switch attached to a valve body of a fuel filter will be described as an example.

That is, FIG. 1 shows a clogging alarm switch 10 showing one embodiment of the present invention, and this clogging alarm switch 10 is incorporated into a filter body 14 of a fuel filter 12 as shown in FIG.

The fuel filter 12 has a cylindrical case 1 with a bottom.
An annular filter element 20 is housed in an internal space 18 whose upper end opening direction is liquid-tightly closed by the filter body 14.
As a result, the internal space 18 is divided into a primary side chamber 18a and a secondary side chamber 18b.

The filter body 14 is formed with a fuel inlet 14a at the peripheral edge and a fuel outlet 14b at the center, and the inlet 14a is connected to the primary side chamber 14.
8a, and the discharge port 14b also communicates with the secondary side chamber 18b via a passage 22a formed inside a center bolt 22 that tightens and fixes the case 16 and the filter body 14.

Further, a storage hole 24 for the clogging alarm switch 10 is formed in the filter body 14, and a first passage 26 communicating with the primary side chamber 18a is formed in the bottom surface 24a of the storage hole 24. A second passage 28 is formed on the side of the discharge port 24, which communicates with the discharge port 14b, that is, the secondary side chamber 18b.

As shown in FIG. 1, the clogging alarm switch 10 includes a case 30 as an insert body housed in the housing hole 24, and a hollow portion 3 of the case 30.
0a, a diaphragm 34 fixed between the case 30 and the bottom surface 24a as a flat seat of the storage hole 24, and the piston 3.
2, a Hall element 38 for detecting movement of the magnet 36, and the like.

A threaded portion 30b is formed on the outer circumference of the case 30, and the case 30 is fixed to the filter body 12 by screwing the threaded portion 30b into the inner circumference of the storage hole 24.

The piston 32 is formed into a cylindrical shape with a bottom that is open at the top in the figure, and the lower end of the piston 32 is brought into contact with the diaphragm 34, and the flange 32a formed on the outer periphery is inserted into the hollow part 30a. It abuts against the step portion 30c from above.

Further, the piston 30 is provided with a lid 4 that closes the flange portion 32a and the upper end opening of the hollow portion 30a.
0 is biased downward in the figure, that is, in the direction of the diaphragm 34.

Furthermore, the magnet 3 is placed inside the piston 32.
6 is fixed.

On the other hand, a cylindrical portion 40a that is inserted between the pistons 32 is formed in the center of the lid 40, and the Hall element 38 is inserted into the cylindrical portion 40a.
As shown in the figure, the piston 32 is housed in the lowermost position and displaced upward in the figure with respect to the magnet 36.

The harness 38a extending from the Hall element 38 is connected to an alarm device (not shown), such as a pilot lamp or an alarm buzzer, and the lid 40 and harness 38a are connected to the case 30 by a filling 44 such as resin. Fixed at the top end.

Further, the Hall element 38 is a non-contact switch, for example, a bipolar digital IC is used,
It has a function of generating (turning on) an electrical signal when magnetic force (magnetic flux) acts on the Hall element 38.

By the way, the peripheral edge of the diaphragm 34 is fastened to the bottom surface 24a of the storage hole 24 through the lower end of the case 30, but in this embodiment, a disk-shaped slide plate 50 is provided between the diaphragm 34 and the bottom surface 24a. The diaphragm 34 is connected to the case 30 and the bottom surface 24 via the slide plate 50.
It is sandwiched between a.

FIG. 3 shows an exploded perspective view of a main part of the joint between the case 30 and the slide plate 50, and as shown in the figure, the slide plate 50 has the case 30
A recess 52 is formed to receive the lower end of the recess 52 , and an undercut groove 54 is formed in the inner circumferential wall of the recess 52 to fit the claw 30 d projecting radially from the case 30 .

Note that the claw 30d is connected to the undercut groove 5.
4, when the pawl 30d is rotated in the screwing direction of the case 30, the pawl 30d is rotated by a predetermined amount.
0d is structured to be locked in the undercut groove 54 in the rotational direction.

Further, a peripheral opening 56 is formed on the outer periphery of the slide plate 50, and a seal ring 58 as a sealing member is fitted into the peripheral opening 56, and the outer periphery of the slide plate 50 and the storage hole 24 are connected to each other via the seal ring 58. The inner periphery of the inner periphery is sealed for relative rotation.

Further, a first through hole 60 communicating with the first passage 26 is formed in the center of the slide plate 50, and a second through hole 62 communicating with the second passage 28 is formed in the side wall of the upper case 30. is formed, and primary side pressure is introduced to one side of the diaphragm 34 via the first passage 26 and the first through hole 60,
Secondary side pressure is introduced above the diaphragm 34 through the second passage 28 and the second through hole 62.

In the clogging alarm switch 10 using the fastening structure of this embodiment with the above configuration, the filter element 20 becomes clogged and the pressure on the secondary side becomes extremely low compared to the pressure on the primary side. In this case, the primary pressure becomes extremely high compared to the total pressure of the spring 42 and the secondary pressure.

Therefore, the diaphragm 34 moves the piston 32 upward from the state shown in FIG. As a result, the Hall element 38
is activated and issues an alarm output.

Note that even if pressure acts in the hollow part 30a of the case 30 through the first and second passages 26 and 28, the diaphragm 34
Since the space between the primary and secondary sides of is closed,
Liquid leakage between the first and second passages 26, 28 is prevented.

Therefore, even if the total amount of fuel filtered by the fuel filter 12 is small, the differential pressure between the primary side and the secondary side is reliably detected as the displacement of the diaphragm 34, and the piston 32 moves according to the differential pressure. will be moved.

Further, the movement of the piston 32 is detected by the Hall element 38 via the magnet 36, and when the piston 32 moves a predetermined amount and the magnet 36 approaches the Hall element 38 as described above, the Hall element 38 is turned on.

By the way, the clogging alarm switch 10 of this embodiment
In this case, the peripheral edge of the diaphragm 34 is tightened to the bottom surface 24 of the storage hole 24 at the lower end of the case 30 that is screwed into the storage hole 24, but a slide plate 50 is interposed between the diaphragm 34 and the bottom surface 24a. The slide plate 50 is rotated together with the case 30 with the claw 30d of the case 30 being engaged with the undercut groove 54.

Therefore, the diaphragm 34 between the case 30 and the slide plate 50 is tightened while rotating together with the case 30, preventing torsional deformation of the diaphragm 34 and ensuring a seal between the case 30 and the slide plate 50.

On the other hand, the slide plate 50 is sealed with the storage hole 24 by a seal ring 58 provided on its outer periphery, and the diaphragm 34 and the seal ring 58 ensure that the primary side pressure and the secondary side pressure are maintained. is blocked by.

Although this embodiment shows a case in which the fastening structure of the present invention is applied to the clogging alarm switch 10 of the fuel filter 12, the fastening structure of the present invention is not limited to this, and may be applied to a general structure in which an elastic body is fastened to a flat seat. It goes without saying that the present invention can be applied to parts to be fixed.

<<Effects of the invention>> As explained above, in the fastening structure of the present invention, when tightening the elastic body between the insert body and the flat seat of the storage hole into which the insert body is screwed, the elastic body Since a slide plate that rotates together with the insert body is provided between and the top view, when the insert body is screwed in, the entire elastic body is rotated and tightened together with the insert body.

Therefore, since no torsional deformation occurs in the elastic body,
A seal between the insert and the slide plate is ensured.

Furthermore, since the space between the slide plate and the flat seat is sealed by the sealing member provided between the outer periphery of the slide plate and the inner periphery of the storage hole, the space between the insert body and the flat seat is sealed by the elastic body. Moreover, the excellent effect of being able to securely seal with the sealing member is achieved.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of essential parts showing an embodiment of the present invention;
FIG. 2 is an overall sectional view showing an embodiment of the present invention, and FIG. 3 is an exploded perspective view of essential parts of an embodiment of the present invention. 10...Clogging alarm switch, 12...Fuel filter, 24...Storage hole, 24a...Bottom surface (flat seat), 30...Case (insert body), 30b...Threaded portion, 34...Diaphragm (elastic body), 50...
Slide plate, 52... recess, 54... undercut groove, 56... peripheral opening, 58... seal ring (sealing member).

Claims (1)

[Scope of utility model registration request] An elastic body is interposed between the flat seat of the storage hole and the insert body that is screwed into the housing hole, and by screwing the insert body, the elastic body is tightened to the above plan view, and the flat seat and In the fastening structure for sealing with the insert, a slide is provided between the elastic body and the flat seat, the slide being engaged with the insert in a screwing direction and being fitted in the storage hole so as to be relatively rotatable. A fastening structure comprising: a plate; and a sealing member provided between the outer periphery of the slide plate and the inner periphery of the storage hole.