JP5053487B2 - Dustproof device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention is, for example, attached to the front side of a sensor that measures the surface temperature of an object by receiving infrared rays radiated from the surface of the object through an optical system lens, and prevents dust, dirt, and moisture from being received by the sensor. The present invention relates to a dustproof device for preventing adhesion and removing them.
[0002]
[Prior art]
As a conventional dustproof device, as shown in FIG. 6, one end side is closed by a light transmission member (not shown) such as an optical lens, and the main passage 1 is linearly formed from the one end to the other end. And an introduction path 2 for introducing the gas G into the main passage 1.
[0003]
The dustproof device is, for example, a sensor (not shown) that measures the surface temperature of an object by receiving infrared rays emitted from the surface of the object (not shown) through an optical lens (not shown). Installed on the front side. And it arrange | positions ahead of the said sensor by sending gas G in the main channel | path 1 from the introduction path 2 of the said dustproof apparatus, and setting it as the state where the gas G is flowing from the one end side of the main channel | path 1 to the other end side. The surface of the optical system lens is prevented from adhering dust, dirt and moisture, and the adhering them are removed.
[0004]
[Problems to be solved by the invention]
However, the conventional dustproof device having the above-described configuration cannot sufficiently achieve the effect of effectively preventing the removal of dust, dirt, moisture and the like that hinder the light reception of the sensor. This will be described with reference to FIG. In FIG. 6, the color density represents the occupancy rate of the gas G, and the darker the color, the higher the occupancy rate of the gas G.
[0005]
That is, in the conventional dustproof device, most of the gas G from the introduction passage 2 is opposite to the side (upper side in FIG. 6) to which the introduction passage 2 of the main passage 1 is connected (lower side in FIG. 6). ) And then proceed along the inner wall on the lower side of the main passage 1 to be led out from the other end side of the main passage 1 as it is. Therefore, as shown in FIG. 6, since the gas G from the introduction path 2 did not flow along the center of the surface of the optical system lens, the replacement efficiency near the surface of the optical system lens did not increase, There was a problem that dust, dust, moisture, and the like were not prevented and adhered matter was not sufficiently removed.
[0006]
Further, the gas G from the introduction passage 2 did not pass through the main passage 1 almost uniformly, but most of it flowed along the inner wall on the lower side of the main passage 1, so that it was released to the atmosphere. Air A containing dust, dirt, moisture, etc. flows into the main passage 1 from the other end side of the main passage 1 in a state, and dust, dust, moisture, etc. that hinder the reception of the sensor continue in front of the sensor. There was a problem that it was introduced.
[0007]
In order to solve the above problem, it is conceivable to increase the amount of the gas G introduced from the introduction path 2, but in this case, the running cost increases as the amount of gas used increases. Become. Further, when the dustproof device is carried and used, the gas G is supplied from a portable cylinder or the like. However, as the amount of use of the gas G increases, the time during which the gas G can be used decreases. As a result, the usable time of the sensor is shortened.
[0008]
As another solution, it is conceivable to lengthen the main passage 1 and stabilize the flow of the gas G. In this case, however, the dustproof device becomes long and it is difficult to make it compact. There was a problem.
[0009]
The present invention has been made in consideration of the above-mentioned matters, and its purpose is to prevent adhesion / inflow of dust / dust / moisture that interferes with light reception of the sensor and to prevent adhesion / inflow without increasing the amount of gas used. An object of the present invention is to provide a dustproof device that can reliably remove them and can be made compact.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, the dustproof device of the present invention has one end side closed by a light transmitting member such as an optical lens, while the other end side is open to the atmosphere. A main passage formed linearly up to the end and an introduction passage for introducing gas into the main passage;
A dustproof device in which gas is sent from the introduction path into the main passage, and gas flows from one end side to the other end side of the main passage,
The gas introduced into the main passage from the introduction passage and advanced from the main passage to the other end of the main passage into the atmosphere from the main passage and returns from the other end of the main passage toward the one end of the main passage. A protrusion that forms a flow is provided so as to protrude inward from the inner wall of the main passage ;
Further, the main passage has a portion having a small cross-sectional area on one end side and a portion having a large cross-sectional area on the other end side, and gas is supplied from the introduction path to the cross-sectional area on one end side of the main passage. It is the structure introduced toward a small part (Claim 1).
[0011]
With the above configuration, without increasing the amount of gas used, it is possible to reliably prevent adhesion / inflow of dust, dust, moisture, etc. that interferes with the light reception of the sensor and to remove them. It is possible to provide a dustproof device capable of achieving the above.
[0012]
The dustproof device according to the present invention is attached to the front side of a sensor that measures the surface temperature of an object by receiving infrared rays radiated from the surface of the object through the light transmitting member .
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to reference examples .
FIG. 1A is an explanatory diagram schematically showing a configuration of a dustproof device D of a reference example .
In the dustproof device D, one end side is closed by a light transmitting member 3 that transmits light such as an optical lens, and the one end to the other end are linearly formed, and the gas G is supplied to the main passage 1. And an introduction path 2 for introduction.
[0014]
The dust-proof device D receives light from a specific object such as a sensor that measures the surface temperature of the object by receiving infrared rays emitted from the surface of the object (not shown) through an optical lens. Dust, dust, moisture, etc. that are attached to the front side (the object side) of the sensor S of the type that receives light through the light transmitting member 3 by fitting, screwing, etc. This is for preventing the adhering to the light transmitting member 3 and removing the adhering them.
[0015]
The main passage 1 has a substantially circular cross section, and the cross-sectional area thereof is substantially constant from one end side to the other end side. The other end side of the main passage 1 is open to the atmosphere. It is in a state. In addition, a protrusion 4 that protrudes toward the inside of the main passage 1 is formed near the other end of the main passage 1.
[0016]
As shown in FIG. 2 (A), the protrusion 4 may be provided with an annular longitudinal section along the inner peripheral wall in the vicinity of the other end of the main passage 1, or as shown in FIG. As shown by a solid line in B), a longitudinal section along the position of the inner peripheral wall near the other end of the main passage 1 except for the vicinity of the side to which the introduction path 2 is connected (upper side in FIG. 1). May be provided so as to be substantially C-shaped. 2B, the protruding portion 4 indicated by a solid line is connected to the introduction path 2 on the inner peripheral wall in the vicinity of the other end side of the main passage 1, as indicated by a virtual line in FIG. Along the position in the vicinity of the upper side in FIG. 1, it may also have portions 4 a, 4 a... Protruding at appropriate intervals in the circumferential direction of the inner wall of the main passage 1. When configured, the gas G led out from the main passage 1 to the outside can be rectified.
[0017]
Further, as shown in FIG. 1 (A), the protrusion 4 may be formed so that the cross section thereof is rectangular or square, but as shown in FIG. The surface facing the upstream side (one end side of the main passage 1) may be a tapered surface that becomes narrower toward the downstream side, or conversely, may become a tapered surface that becomes wider toward the downstream side. (Not shown), as shown in FIG. 3B, the cross section may be formed in a mountain shape.
[0018]
Note that the shape of the protruding portion 4 is not limited to the above, and various modifications are possible. For example, even if the cross section thereof is formed into a circular shape, an elliptical shape, or a semicircular shape. Good.
[0019]
Furthermore, the protrusion 4 may be provided along the other end of the main passage 1 as shown in FIG. 1A, or the other of the main passage 1 as shown in FIG. It may be provided at a position spaced from the end to one end side (upstream side). Further, in FIG. 1, the introduction path 2 is shown as being orthogonal to the main path 1, but is not limited thereto.
[0020]
The introduction path 2 is connected to a position slightly spaced from one end of the main passage 1 to the other end side. As a result, the gas G introduced from the introduction passage 2 into the main passage 1 flows in front of the light transmission member 3. The position of the introduction channel 2 is not limited to those described above, for example, before it may be provided substantially equidistant a position of Kinushi passage 1 of the other end and the light transmission member 3 which, main passage 1 may be connected to one end.
[0021]
The gas G introduced into the main passage 1 from the introduction passage 2 is a purge gas made of, for example, an inert gas such as nitrogen or argon, which does not adversely affect the light received by the sensor S.
[0022]
The light transmission member 3 may be an optical system lens serving as a light condensing unit for the sensor S positioned behind the light transmitting member 3, or provided separately from the optical system lens serving as the light condensing unit for the sensor S. It may be a substantially plate-like member made of quartz or the like provided for transmitting light from the substrate.
[0023]
FIG. 1B is an explanatory diagram schematically showing the configuration of the dustproof device D in a state where the gas G is caused to flow from the introduction path 1. Specifically, the gas G is introduced from the introduction path 2 into the main passage 1. As a result, the gas (for example, air) filled in the main passage 1 in the initial state is discharged and replaced with the gas G, but when this replacement is stably in a steady state, It is the figure which confirmed the distribution (replacement) situation of the gas in dustproof device D by calculation. In FIG. 1B, the color density represents the occupation ratio of the gas G in that portion, and the darker the portion, the higher the occupation ratio.
[0024]
In the dustproof device D having the above-described configuration, as shown in FIG. 1B, when the gas G is introduced from the introduction path 2 into the main path 1, most of the introduced gas G is introduced into the main path 1. It collides with the inner wall on the side (the upper side in FIG. 1) to which the path 2 is connected and the opposite side (the lower side in FIG. 1), and then along the inner wall on the lower side of the main path 1, Proceeds to the other end side, collides with the projecting portion 4 provided on the other end side of the main passage 1, a part is led out to the front (external) atmosphere with the upward flow, and a part is It rebounds and flows again to the center side of the main passage 1 and eventually to one end side.
[0025]
Therefore, the gas G flows along the surface of the light transmission member 3 and also flows through the main passage 1 almost uniformly, for example, through the central portion of the main passage 1. Dust, dust, moisture, etc. are prevented from adhering to the main passage 1, and the adhering them are sufficiently removed, and from the other end side of the main passage 1 in a state opened to the atmosphere, The air A containing dust, dirt, moisture or the like does not flow into one end side (inside) of the gas, and a flow is formed that suppresses the entrainment of outside air near the other end of the main passage 1 by the gas G. Become. Therefore, according to the dustproof device D, it is possible to prevent dust, dirt, moisture, or the like that hinders the light reception of the sensor S from being continuously introduced into the front of the sensor S. Therefore, it is possible to reliably prevent and remove dust, dust, moisture, and the like from adhering to the light transmitting member 3.
[0026]
Further, the dustproof device D having the above-described configuration can increase the gas replacement rate in the main passage 1 from the introduction passage 2 by providing the protrusion 4 in the vicinity of the other end of the main passage 1, and a small amount. The gas G can prevent the outside air from entering the main passage 1 from the other end of the main passage 1. Further, even if the main passage 1 is shortened, the replacement efficiency can be improved and the outside air can be effectively prevented, so that the dustproof device D can be made compact and the range of the place where the dustproof device D can be attached. Can also be expanded.
[0027]
FIG. 4A is an explanatory diagram schematically showing the configuration of the dustproof device D ₂ according to one embodiment of the present invention. In addition, about the member of the same structure as what was shown to the said reference example, the same code | symbol is attached | subjected and the description is abbreviate | omitted.
This dustproof device D ₂ differs from the dustproof device D of the reference example in that the cross-sectional area near one end side of the main passage 1 is formed to be smaller than the cross-sectional area near the other end side. .
[0028]
That is, the main passage 1 of the dustproof device D ₂ is subjected other end from one end, the small-diameter portion 1a, and has a tapered portion 1b and the large diameter portion 1c.
[0029]
The small-diameter portion 1a has a substantially circular cross section, and the cross-sectional area is a substantially constant path from one end to the tapered portion 1b. The introduction path 2 is connected to the small diameter portion 1a.
[0030]
The tapered portion 1b is a passage having a substantially circular cross section and a sectional area that decreases from the other end side to the one end side.
[0031]
The large-diameter portion 1c has a substantially circular cross section, and the cross-sectional area is a substantially constant path from the tapered portion 1b to the other end.
[0032]
The diameter of the other end portion of the main passage 1 is arbitrarily determined in consideration of the relationship between the viewing angle of the sensor S and the distance from the sensor S to the other end portion. The same applies to the formation of the small-diameter portion 1a from the above, or the diameter of the small-diameter portion 1a.
[0033]
Other configurations are the same as those of the dustproof device D of the reference example, and thus the description thereof is omitted.
[0034]
FIG. 4B is an explanatory diagram schematically showing the configuration of the dustproof device D _{2 in} a state where the gas G is caused to flow from the introduction path 2. Specifically, the gas G is introduced from the introduction path 2 into the main passage 1. By doing so, the gas (for example, air) filled in the main passage 1 in the initial state is exhausted and replaced with the gas G. diagrams confirming flow of the gas in the dustproof device D ₂ (substituted) status by calculation. In FIG. 4B, the color density represents the occupation ratio of the gas G, and the darker the portion, the higher the occupation ratio.
[0035]
In the dustproof device D _{2 having the} above-described configuration, in addition to the effect obtained by the dustproof device D of the reference example, one end side (upstream side) of the main passage 1 is narrowed down. An effect is obtained that the required amount of the gas G from the introduction path 1 used for removing dust, moisture, and the like can be reduced (for example, about ½).
[0036]
FIG. 5 is an explanatory view schematically showing a specific arrangement method of the dustproof device D of the reference example.
For example, the light transmitting member 3 is held inside a holding portion 5 a having a substantially cylindrical shape. And the dustproof apparatus D is arrange | positioned so that the one end side inner surface of the main channel | path 1 may follow the outer peripheral surface of the said holder 5. FIG. Further, a gap is not formed between the light transmitting member 3 and the holding portion 5a and between the holding portion 5a and the main passage 1.
[0037]
The arrangement method of the light transmissive member 3 may be applied to a dust-proof device D ₂ of the above embodiment.
[0038]
【Effect of the invention】
As described above, according to the present invention configured as described above, without increasing the amount of gas used, it is possible to prevent adhesion / inflow of dust, dirt, moisture, etc., which interferes with light reception of the sensor, and those that have adhered / inflowed. It is possible to provide a dustproof device that can be reliably removed and can be made compact.
[Brief description of the drawings]
FIG. 1A is an explanatory diagram schematically showing a configuration of a dustproof device according to a reference example, and FIG. 1B is an explanatory diagram schematically showing the above-described reference configuration in a state where gas is flowed from an introduction path. It is.
FIGS. 2A and 2B are explanatory views schematically showing configurations of an example of a protrusion and another example in the reference example and the embodiment of the present invention . FIGS.
FIGS. 3A, 3B, and 3C schematically illustrate the configurations of a modified example of the protrusion, another modified example, and still another modified example in the reference example and the embodiment of the present invention. It is explanatory drawing shown.
4A is an explanatory diagram schematically showing the configuration of a dustproof device according to one embodiment of the present invention, and FIG. 4B is a schematic diagram showing the configuration of the above-described embodiment in a state where gas flows from an introduction path. FIG.
FIG. 5 is an explanatory diagram schematically showing a specific arrangement method of the dustproof device according to the reference example.
FIG. 6 is an explanatory view schematically showing a configuration of a conventional dustproof device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Main channel | path, 1a ... Small cross-sectional area part, 1c ... Large cross-sectional area part, 2 ... Introduction path, 3 ... Light transmission member, 4 ... Protruding part, D ... Dust-proof device, G ... Gas.

Claims (2)

One end side is closed by a light transmitting member such as an optical system lens, and the other end side is open to the atmosphere, and the main passage is formed linearly from the one end to the other end. An introduction path for introducing gas into the passage,
A dustproof device in which gas is sent from the introduction path into the main passage, and gas flows from one end side to the other end side of the main passage,
The gas introduced into the main passage from the introduction passage and advanced from the main passage to the other end of the main passage into the atmosphere from the main passage and returns from the other end of the main passage toward the one end of the main passage. A protrusion that forms a flow is provided so as to protrude inward from the inner wall of the main passage ;
Further, the main passage has a portion having a small cross-sectional area on one end side and a portion having a large cross-sectional area on the other end side, and gas is supplied from the introduction path to the cross-sectional area on one end side of the main passage. A dustproof device characterized by being configured to be introduced toward a small portion . The dustproof device according to claim 1, wherein the dustproof device is attached to a front side of a sensor that measures the surface temperature of an object by receiving infrared rays emitted from the surface of the object through the light transmitting member .

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