JP2606911Y2 - Shield case - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shield case, and more particularly to an improvement in a seal structure thereof.

[0002]

2. Description of the Related Art For example, in a Fourier transform infrared spectrophotometer, when a deliquescent crystal is used as an interferometer beam splitter, the interferometer or its surroundings are also used to prevent the crystal from being dissolved by water vapor. A method has been adopted in which the optical system including the casing is sealed with a case and the inside of the case is kept at a low humidity. In a shield case that seals the interferometer and the like, the interferometer is mounted on an optical base, and the periphery thereof is conventionally covered with a cover formed by welding a sheet metal. Further, a groove is formed at a position where the cover of the optical base is attached, a single cell sponge string is provided in the groove, and the base and the cover are brought into close contact with the single cell sponge string to improve airtightness in the case. Was. Further, a supply pipe for supplying a purge gas into the case and a discharge pipe for discharging the purge gas are connected to the cover of the case, and the purge gas is provided by opening and closing a gas cock provided on the supply pipe and the discharge pipe. Supply and discharge.

[0003]

However, the conventional shield case has the following problems.
Forming the cover by sheet metal welding and forming a sponge string on the optical base increases the cost. If the cover has a sheet metal welding structure, it is very difficult to process a complicated shape, and the cover cannot be formed along the optical system to be covered, resulting in a large size. Since the sheet metal forming the cover is heavy, the entire apparatus also becomes heavy.

In order to improve the sealing performance of the shield case, the surface of the cover to be attached to the base is formed flat, but when the cover is removed, the attachment surface is inadvertently attached to the floor or the like. If it is placed facing, dust and the like will adhere to the mounting surface, and the sealing property will be reduced. Further, while the shield case has to improve the sealing property, when a large pressure difference occurs between the inside and the outside of the case, the better the sealing property, the greater the pressure applied to the cover and the like. There is also a problem that a material portion having low mechanical strength, such as a measurement light transmission window provided in the above, may be damaged.

Further, the conventional shield case is provided with a gas supply pipe and a gas discharge pipe for gas purging, and performs gas purging by opening and closing gas cocks provided respectively on the two pipes. If the user forgets to do so, the internal parts may be damaged, or the operation of the purge gas flow using the gas cock may be troublesome, resulting in poor workability.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and has as its object to easily form a cover having a shape along an optical system mounted on a base, and to provide a light-weight, good sealing property. It is to provide an inexpensive shield case. Another object of the present invention is to provide a shield case in which dust and the like hardly adhere to a mounting surface of a cover removed from a base, and a case is not damaged even when a pressure difference occurs between the inside and the outside of the case.

[0007]

To achieve the above object, a shield case according to the present invention comprises a base and a seal.
A cover, a cover fixing member, a sealing material, and a gas supply passage.
Vents and gas exhaust vents, relief valve for external pressure,
An internal pressure relief valve.
Here, the base is used for various parts and equipment of an optical measuring instrument.
Place the device. Further, the seal cover is provided on the base.
A tree that is provided detachably on the surface and covers the parts and devices
It consists of a fat molded product. The cover fixing member includes a seal.
Secure the cover to the base. The sealing material is
Is held on the sealing surface of the cover. The gas supply vent
Is provided through the seal cover or the base.
Vent holes for supplying purge gas into the case.
The gas exhaust vents allow the gas inside the case to
It is a vent for discharging. The relief valve for external pressure
The gas supply vent is provided in the gas supply vent, and the case internal pressure is reduced.
Automatically opens when the pressure becomes lower than
The purge gas can be supplied into the source. Lily for internal pressure
The valve is provided in the gas discharge vent, and a case
Automatically starts when the internal pressure exceeds the case external pressure by more than a certain amount
The purge gas in the case can be discharged to the outside.
You. In addition, the external pressure relief through the gas supply vent hole
A gas inlet pipe connected to the valve, and the gas inlet pressure
It is preferable that the relief valve for external pressure is opened by
It is. Use a 0 ring for the sealing material
Are also suitable.

[0008] Further , taking the seal cover into the base.
A plurality of protrusions provided on the attachment portion,
The protrusion provided at a position corresponding to the protrusion is fitted.
And a fitting hole.

[0009]

In the shield case according to the present invention, as described above, since the seal cover for covering the components and devices mounted on the base is made of a resin molded product, the shield case has a complicated shape along the outer periphery of the components and devices. Therefore, the size can be reduced to a necessary minimum and the weight can be reduced. In addition, the seal cover or the base has two through holes.
A vent valve, and a relief valve for internal pressure in one of the vent holes
And a relief valve for external pressure on the other side.
Pressure difference between the inside and outside of the shield case
The relief valve opens to reduce the pressure difference.
To prevent damage to the shield case.
It becomes possible. Also, the gas flow is supplied to the external pressure relief valve.
Since the inlet pipe is connected, the external pressure is
The relief valve opens to supply gas, and the gas supply
When the pressure inside the shield case increases due to
The gas relief valve is opened to discharge gas.
When the gas supply is stopped, the external pressure relief valve
As the case closes and the case internal pressure drops, the internal pressure
The leaf valve is also closed and the gas purge is completed. This
Gas supply and discharge automatically by the relief valve
Is performed, which improves the workability of gas purge.
To prevent internal parts from being damaged due to forgetting to close the gas cock.
It becomes possible.

Further , the seal cover is a resin molded product.
O-ring etc. on the sealing surface of the seal cover
Can easily form a groove for holding the sealing material
Because there is no need to form a groove in the base,
Can be obtained.

[0011] Further , taking the seal cover into the base.
Since the projection is provided on the attachment surface, the seal cover
Even if the mounting surface is placed facing the floor etc.
Only the floor is in contact with the floor and retained on the sealing surface of the seal cover
Clearance between the sealed material and the floor
To prevent dust and dirt from adhering to the sealing material
Becomes possible.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram of a shield case according to an embodiment of the present invention. The shield case shown in FIG. 1 includes a base 12 on which an optical component 10 such as an interferometer is mounted, a seal cover 14 for covering and sealing the optical component 10 from above, and
And an O-ring 18 as a sealing member provided on a sealing surface between the base 12 and the seal cover 14. Further, the seal cover 14 is provided with a window holder 20 in which a measurement light transmitting window is fitted.

The first feature of the present embodiment is that the seal cover 14 is a resin molded product. Since the resin molding has a high degree of freedom in shape, even if the optical component 10 has a complicated shape with many irregularities, it can be easily molded into a shape conforming to the optical component 10 and the cost can be reduced. On the other hand, in the conventional sheet metal welding structure, it is technically difficult to obtain the complicated shape, and there is a limit, and the cost increases. As a result, when the seal cover 14 is made of resin, the volume can be reduced by about 25% and the weight can be reduced by about 60% as compared with the conventional sheet metal welding structure.
The weight could be reduced. Further, by forming the seal cover 14 as a resin molded product, the sealing surface can be formed smoothly and stably, and good sealing properties can be obtained.

A groove is formed in the seal surface of the seal cover 14, and an O-ring 18 having excellent sealing properties is held in the groove. That is, conventionally, the seal cover 1
Since 4 is a sheet metal, the groove for holding the sealing material is formed on the base 1.
It was processed and formed on two sides. However, since the seal cover 14 according to the present embodiment is formed by resin molding having a high degree of freedom as described above, the groove can be formed in the seal cover 14, and the groove is formed on the seal surface of the base 10. The cost can be further reduced without having to perform the operation. A groove is also formed in the portion of the seal cover 14 where the window holder 20 is mounted, and the O-ring 19 is held in the groove to improve the sealing performance of the mounting portion.

Further, the base 1 of the seal cover 14
A plurality of projecting cover legs 22 are formed on the portion to be attached to 2 by making use of the degree of freedom in shape of resin molding. For this reason, when the seal cover 14 is removed from the base 12 and placed on a floor or the like, even if the seal surface of the seal cover 14 faces downward, only the cover legs 22 contact the floor and are held by the seal surface. Clearance is secured between the O-ring 18 and the floor, so that the O-ring 18 does not contact the floor. Therefore, dust, dust, and the like hardly adhere to the seal portion of the O-ring 18, and deterioration of the sealability can be prevented.

A fitting hole is formed in the base 12 at a position corresponding to the cover leg 22, so that the cover leg 22 fits into the fitting hole when the seal cover 14 is attached. Further, the shield case according to the present embodiment has two vent holes 24 in the base 12.
a, 24b are provided, and a relief valve 26 for external pressure is provided inside the case of the ventilation hole 24a, and the ventilation hole 24
An internal pressure relief valve 28 is provided inside the case b.

As described above, the better the sealing performance of the shield case, the better. However, when the pressure difference between the inside and the outside of the case is large, the force applied to the seal cover 14 is large, and the shielding light of the measurement light transmission window and the like is increased. There is a risk of damage to the low strength material. In this embodiment, the external pressure relief valve 26 and the internal pressure relief valve 28 are provided to prevent the internal / external pressure difference of the case from becoming larger than a certain value. The external pressure relief valve 26
Opens when the external pressure becomes higher than the internal pressure of the case by a certain degree or more, and the internal pressure is increased by introducing external air into the case. On the other hand, the internal pressure relief valve 28 is opened when the internal pressure is higher than the external pressure of the case by a certain degree or more, to release the internal air to the outside and reduce the internal pressure.

As described above, when the difference between the internal and external pressures of the shield case becomes equal to or more than a certain value, the external pressure relief valve 26
Alternatively, the internal pressure relief valve 28 is opened to maintain the internal and external pressures evenly, thereby preventing damage to the measurement light transmission window and the like. Furthermore, in this embodiment, the gas purge in the case can be efficiently performed by connecting the gas inflow pipe 30 to the external pressure relief valve 26 through the vent hole 24a.

That is, when the purge gas flows into the gas inflow pipe 30, the external pressure relief valve 26 is opened by the inflow pressure, and the purge gas is introduced into the case. When the purge gas continues to flow into the case, the internal pressure of the case increases, and the internal pressure relief valve 28 opens to perform purging. When the inflow of the purge gas is stopped, the external pressure relief valve 26 closes, then the pressure in the case decreases, and the internal pressure relief valve also closes, completing the shield in the case. As described above, by using the relief valve, the conventional operation of opening and closing the gas cock is unnecessary, and the workability is improved, and damage to the internal parts due to forgetting to close the gas cock can be prevented.

[0020]

As described above, according to the shield case of the present invention, since the seal cover is formed of a resin molded product, the seal cover having a shape suitable for the device mounted on the base can be easily and inexpensively manufactured. Can be molded into In addition, since a projection is provided on the part where the seal cover is attached to the cover,
When the seal cover is removed, the seal member does not come into contact with the floor or the like, so that adhesion of dirt and dust can be prevented. Also,
By providing a relief valve for external pressure and a relief valve for internal pressure, it is possible to prevent the internal / external pressure difference of the case from becoming larger than a certain value, and to improve operability of gas purging by connecting a gas inflow pipe to the relief valve for external pressure. Becomes possible.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a schematic configuration of a shield case according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 12 ... Base 14 ... Seal cover 18 ... O-ring 22 ... Cover leg (projection part) 24 ... Vent hole 26 ... Relief valve for external pressure 28 ... Relief valve for internal pressure 30 ... Gas inflow pipe

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Masami Takigawa 5 Nisshin Bunko Co., Ltd., 2967 Ishikawacho, Hachioji-shi, Tokyo (56) References JP-A-5-133806 (JP, A) JP-A-4 -346499 (JP, A) JP-A-62-57866 (JP, A) JP-A-62-164325 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01J 3/00- 3/52 G01N 21/00-21/73 B65D 53/00-53/10

Claims (4)

(57) [Scope of request for utility model registration] (1)Optical measuring equipmentSeals various parts and equipment
And gas purgeableIn the shield case, a base on which the component and the device are placed, and the component and the device are detachably provided on the base,
A seal cover made of a resin molded product to be covered, and a cover fixing member for fixing the seal cover to a base
A sealing material held on a sealing surface of the seal cover;It is provided through the seal cover or base,
Gas supply vents to supply purge gas into the source
Gas exhaust for exhausting gas inside the case and outside
Pores, The case is provided in the gas supply vent, and the case internal pressure is outside the case.
When the pressure becomes lower than a certain level, it automatically opens,
An external pressure relief valve that can supply purge gas to the The gas exhaust vent is provided in the case, and the case internal pressure is outside the case.
When the pressure becomes higher than a certain level, it automatically opens and
Internal pressure relief valve that can discharge the gas to the outside,  A shield case comprising: 2. The shield case according to claim 1, wherein the gas supply vent is connected to an external pressure relief valve.
A gas inflow pipe connected to the
A pressure relief valve that opens.
Case. 3. The shield case according to claim 1, wherein said seal member is formed by an O-ring.
Case. (4)According to any one of claims 1 to 3,
In the shield case, The seal cover is provided at a portion to be attached to the base.
A plurality of protrusions, The protrusion provided at a position corresponding to the protrusion of the base.
A fitting hole into which the protrusion fits; A shield case comprising: