JPS6240003B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to waterproof cameras such as all-weather cameras or underwater cameras, and also to waterproof cameras such as waterproof strobes and waterproof radios. The present invention relates to a waterproof device for a pressure valve for regulating pressure inside a case of a small device or instrument, etc., in which a main body is provided.

For example, in a waterproof camera called an all-weather camera, the camera case or housing is sealed to prevent water from entering from the outside, and the parts that are moved by external operations are omitted.
A sealing material such as a ring is used, and the lid, which is opened and closed, is provided with a sealing or locking mechanism so that the inside is airtight when the lid is closed.

However, if a camera with a sealed structure like this is exposed to high temperatures, such as by leaving it on a beach under direct sunlight or placing it near a high heat source, the pressure of the air inside the camera case increases and the air cannot escape and applies its pressure to the inner wall of the camera case. For example, when the temperature rises from 20°C to 70°C, the internal pressure increases by about 0.2 kg/cm ² . Therefore, if the camera case is made of plastic or the like, the air pressure may deform the case, creating a gap between the case and the lid, which may impair the waterproofness, and the deformation of the case may cause the camera to The operation and operation of the system will also be affected.

To deal with this situation, a pressure valve can be installed in a part of the camera case to allow air to escape when the internal pressure of the case increases, and to prevent water from entering from the outside at all times. A pressure regulating device using such a pressure valve has been proposed in Japanese Utility Model Application No. 50-37530 and Japanese Utility Model Application No. 50-37531.

In addition, the applicant has filed a utility model registration application filed on June 29, 1971, for a pressure regulating valve device that eliminates the drawbacks of the conventional device, such as its complicated structure, large number of parts, and poor practicality. is suggesting.

However, in any of these pressure regulating valve devices, there is a possibility that water may infiltrate from the outside of the waterproof case to the pressure regulating valve portion, and the structure is such that once water has entered, it is difficult for it to escape to the outside. If water enters the pressure regulating valve in this way, the pressure regulating valve will not only be unable to perform its intended function, but if the water is of a type such as seawater, it will not be possible to regulate the pressure. Valve components (for example, synthetic rubber membrane members or diaphragms that are opened and closed by internal pressure) are subjected to chemical action, which can change their elastic properties, corrode, or stick.

SUMMARY OF THE INVENTION An object of the present invention is to provide a waterproof structure in the pressure regulating valve device as described above, which prevents water from entering the pressure regulating valve portion from the outside and does not impair the pressure regulating function.

Hereinafter, the present invention will be explained in detail with reference to illustrated embodiments in which the present invention is applied to a camera.

Figures 1A, B and 2 show an embodiment of the present invention.
In the figure, 1 is a plastic molded camera case or camera outer box.
As shown in Publication No. 35782, Design Registration No. 397302, U.S. Patent No. 4041507, or Japanese Patent Application No. 140326/1983, it has a sealed structure, and has a film chamber, shutter mechanism, winding mechanism, Furthermore, a camera mechanism such as a flash device is housed. A circular recess 1a with a diameter of 16 mm is formed in a part of the camera case 1, and a through hole 1b with a diameter of 3.0 mm is provided at the bottom of the recess 1a. 2 is a membrane member or diaphragm made of elastic and durable synthetic rubber such as nitrile rubber, which is provided to cover the entire bottom of the recess, and is mostly a thin membrane with a thickness of about 0.4 mm. It has a circular portion 2a, and its periphery is a thick annular portion 2b. A ventilation hole 2c with a diameter of about 0.8 mm is formed in the approximate center of the membrane part 2a without being deformed.
is open. Reference numeral 3 denotes a valve seat member made of polyacetal material, and as shown in the perspective view from the bottom in FIG. 3d
passes through the upper surface 3b, and the upper surface 3b is a spherical surface so that the membrane part of the membrane member is evenly pressed by its elasticity.
A conical projection 3e that fits into the ventilation hole 2c of the membrane member 2 is formed in the center thereof. Reference numeral 4 denotes a member that presses down the membrane member and also serves as a protective lid for protecting the pressure regulating section consisting of the membrane member 2 and the valve seat member 3;
The pressing member is made of ABS resin material, and the downwardly extending annular portion 4a presses the thick portion 2b of the membrane member downward and compresses the screw 5a,
5b, it is fixed to the camera case. As a result, as long as the ventilation hole 2c of the membrane member 2 is closed by the conical projection 3e of the valve seat member 3, the through hole 1b
Seal the top of the.

On the lower surface of the annular portion 4a of the holding member 4, as shown in FIG. The end 4d extends vertically upward from there and is connected to a vertical hole 4e that opens to the outside of the presser member. As a result, when the annular portion 4a of the presser member 4 presses against the thick wall portion 2b of the membrane member 3, the groove 4b becomes a conduit, and the space between the central lower wall of the presser member 4 and the membrane member 3, i.e. From the valve chamber, the communication portion 4c, the groove 4b,
A ventilation hole is formed that exits through the vertical hole 4e. Here, the cross section from the vertical hole 4e to the communication part 4c is smaller than the size of a water droplet that naturally drips, in other words, the size is such that water droplets cannot enter due to its surface tension, etc., and the cross section is vertical. The length from the outlet of the hole 4e to the communication part 4c changes depending on the water pressure of the air in the conduit part and the valve chamber from the outlet to the communication part when a predetermined water pressure is applied to the outlet of the vertical hole 4e. The length is such that the conduit volume (substantially the sum of the volumes of the vertical hole 4e and the groove 4b) is larger than the volume change.

According to one design example, vertical holes 4e and grooves 4b
The cross-sectional diameter of is 1.0 to 1.5 mm, and the radius of the arc of groove 4b is
6.0mm, the length of the vertical hole 4e is 4.0mm, and the volume of the valve chamber is ^40.0mm3 , while the conduit volume has a cross section of 1.0mm.
When the depth is approximately 30mm ³ , and when it is 1.5mm it is approximately 67mm ³ , and in the former case it is approximately 7.5m, and in the latter case it is approximately 16.7m deep. Most importantly, this is only considering the waterproof effect, and the water pressure and depth at which the entire case can be used must be determined by considering other factors. In addition, the presser member 4
The central lower surface of the valve chamber is shaped to minimize the volume of the valve chamber within a range that allows displacement of the membrane member 3 due to internal air pressure.

Note that FIG. 1A is a sectional view taken along line A--A in FIG. 2.

According to such a configuration, first, the pressure adjustment effect is caused by the internal space 1 of the camera case 1 as the temperature rises.
When the air pressure at hole 3 increases, the air pressure at hole 3 increases.
c and 3d, the membrane part 2a is pushed up against its elasticity to create a gap between the membrane part 2a and the valve seat member upper surface 3a, and the air in the internal space 1c is communicated with the gap and the valve space. part 4c, groove 4b, vertical hole 4
It escapes to the outside through e, and the pressure in the internal space 1c is lowered. As a result, the membrane portion 2a comes into close contact with the upper surface of the valve seat member again, sealing the inside of the camera case.

Next, for example, if the camera case 1 is used in the rain or in a place where it is exposed to water splashes on the coast, and water droplets adhere to or hit the outer surface of the camera case 1,
The cross section of the vertical hole 4e is smaller than a water droplet, and its outlet is sealed by a faucet due to the surface tension of the water, so that water cannot enter through the vertical hole. Further, when the camera case 1 is placed in water at a depth shallower than a predetermined design value, water enters the vertical hole 4e due to the water pressure at that time. However, as mentioned above, the volume of the conduit is larger than the change in the volume of air from the vertical hole to the valve chamber due to the predetermined design value water pressure, so the incoming water is The water pressure from the valve and the compressed air pressure balance, and the water does not travel any further and does not enter the valve chamber. In this way, water ingress into the valve chamber is always prevented. Furthermore, as in the above embodiment, if the conduit does not connect straight to the valve chamber, but is bent in the middle, even if water suddenly enters the conduit, when the water hits the bent part, , the kinetic energy is absorbed at the bent part, and the water does not reach the valve chamber with the force with which it first entered.

FIG. 3 shows a second embodiment of the present invention, and members common to or corresponding to those in the first embodiment are given the same reference numerals as in FIG. 1, and their explanations are omitted. . In the second embodiment, a cover plate 6 is provided on the holding member 4, and a flexible tube 7 is disposed in a spiral shape in a planar manner in the space 8 between the two, and one end 7a of the tube is connected to the holding member 4. The other end 7b is bonded to the ventilation hole 4f of the tube 4, and the other end 7b is bonded to the through hole 6a of the cover plate 6 with an adhesive so that the tube and the peripheral wall of the hole are watertight and airtight. In this embodiment, the outermost cover plate 6 is fixed to the camera case 1 with screws 5a and 5b.

Although two embodiments have been described above, the present invention is not limited to these, and the point is that the valve chamber is connected to the outside through a conduit portion of a predetermined thinness and a predetermined length. For example, instead of storing the tube 7 in a closed space, the tube 7 shown in FIG. In this case, a spiral groove is formed in the concave portion 8 on the upper surface of the presser member from the ventilation hole 4f to the center, and the groove is closed on the upper surface by a cover plate and communicates with the through hole 6a at the center. Various modifications can be made, such as making the upper part of the holding member as shown in Fig. 3 or the modified example of Fig. 3 above, providing a part of the conduit part in the camera case itself, or passing part of the pipe through the camera case. is possible. Furthermore, it goes without saying that the pressure regulating valve is not limited to the illustrated embodiment.

Further, the waterproof case in which the waterproof device of the present invention is installed is not limited to a camera case, but can also be a waterproof case that houses the entire camera, a flash discharge light emitting device, a small radio, a small measuring instrument, etc. Therefore, it can be installed in any device as long as the outer case is sealed and a pressure regulating valve is provided to regulate the internal pressure.

According to the present invention as described above, a waterproof case is provided with a pressure regulating valve that is normally closed and opens when the internal pressure rises to release the air inside, in the air passage communicating between the inside and outside of the waterproof case. Since the air passage from the pressure control valve to the outside of the case has a cross section smaller than the dripping water droplets at least from the outlet to a certain depth, even if water droplets adhere to or hit the outlet, the surface of the water will not be affected. The outlet is sealed by the tension faucet, preventing water from entering the interior, and the length of the small cross section is such that its volume is
This is designed to be larger than the volume change of the air in the air passage from the pressure regulating valve to the vent outlet due to the predetermined external pressure applied to the outlet of the air passage.
Even if the waterproof case is submerged in water, if the water is shallower than the specified water depth, water entering the air passage from the outside will not reach the pressure control valve, and when the waterproof case is taken out of the water, the compressed interior will be removed. The air pushes the water out and the pressure control valve is never wet.

[Brief explanation of the drawing]

FIG. 1A is a longitudinal cross-sectional view of one embodiment of the present invention;
FIG. 2 is a cross-sectional view of the same embodiment, and FIG. 3 is a longitudinal sectional view of another embodiment. 1: Waterproof case, 2, 3: Pressure control valve, 4b,
4c, 4e: ventilation path.

Claims (1)

[Scope of Claims] 1. A pressure regulating valve is provided in the air passage communicating between the inside and outside of the watertight waterproof case, which is closed at all times and opens when the internal pressure rises to release the air inside.
The air passage from the pressure regulating valve to the outside of the case is such that at least a certain depth from its outlet has a cross section smaller than that of the dripping water droplet, and the air passage from the pressure regulating valve to the outlet has a predetermined external pressure applied to the outlet of the air passage. A waterproof device characterized by having a length that has a volume larger than the change in volume of air. 2. A lid member covering the pressure regulating valve is provided, and the lid member is provided with a groove that is to form a ventilation hole portion with a cross section smaller than that of a dripping water droplet and a length that provides a volume larger than the volume change of the ventilation passage due to a predetermined external pressure. A waterproofing device according to claim 1 as formed. 3. The waterproofing device according to claim 2, wherein a part of the vent portion is formed between a groove of the lid member and a pressure regulating valve pressed by the lid member. 4. A portion of the vent portion is formed by a flexible tubular member disposed between a portion of the lid member and a cover member that further covers the lid member from the outside. Waterproofing device as described. 5. The pressure regulating valve is provided with a through hole in the waterproof case that communicates the internal space with the outside, and a membrane member made of an elastic material in which the ventilation hole is formed so that the part where the through hole is provided is connected to the pressure regulating valve. The cover is provided so as to close off the through hole portion except for the ventilation hole, and has an air guide means for allowing air from the case internal space to hit the portion of the membrane member other than the ventilation hole at least during exhaustion. The valve seat member is provided in such a way that the membrane member normally comes into close contact with the valve seat member due to its elastic force and the vent hole is closed. Waterproofing device. 6. The waterproofing device according to claim 5, wherein the case has a vent hole recessed in a circular shape, a valve seat member and a membrane member are provided in the recessed part, and the groove of the lid member is formed in a circular or spiral shape. Device. 7. The waterproof case according to any one of claims 1 to 4, wherein the small cross-sectional area portion of the air passage leading from the pressure control valve to the outside of the case is bent in the middle.