JP2015004741A - Air cover - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air cover which is compact and reliably prevents dust and the like from being attached to a glass by preventing occurrence of vortex flow.SOLUTION: An air cover 10 is attached to an attaching object 61 to surround a glass 63 of the attaching object 61 and has a casing having an opening 12 at an end opposite to the attaching object 61. The air cover 10 has a glass-side ventilation channel 51 provided between the glass 63 and the opening 12 in the casing and extending from the opening 12 side toward the glass 63 side obliquely in a direction crossing an axis line Lc of the casing, and an opening-side ventilation channel 55 provided on the opening 12 side in the casing and extending from the glass 63 side toward the opening 12 side obliquely in a direction crossing the axis line Lc of the casing.

Description

  The present invention relates to an air cover that prevents foreign matter from adhering to glass such as a monitoring camera and a laser transmitter.

  Conventionally, various dustproof mechanisms have been proposed in order to prevent foreign substances such as oil mist, dust, and fluid powder from adhering to glass.

  Patent Document 1 describes a dust-proof camera housing that includes a housing body that houses a camera device therein and a blower that sends air into the housing body. In this camera housing, air is allowed to flow inside the housing body from the rear to the front of the camera device, and the air is discharged through the opening, thereby preventing dust and dirt from adhering to the camera lens. . However, the camera housing is increased in size because the front space portion is provided in addition to the rear space portion that houses the camera device therein.

  Therefore, in Patent Document 2, a transparent plate is provided in front of the camera installed inside the camera case, and the air discharged from the air discharge port is separated from the outer surface and the air layer traveling along the outer surface of the transparent plate. A dust-proof mechanism is described that prevents dust from adhering to the transparent plate by forming an air layer that advances in the direction.

  This dust-proof mechanism can be downsized because it only discharges air to the transparent plate, but the air discharged from the air discharge port travels in parallel with the transparent plate at a predetermined interval from the transparent plate. There is a risk that eddy currents will be generated near the surface of the glass, sucking in dust, etc., and sticking to the transparent plate.

JP-A-6-167670 Japanese Patent Laid-Open No. 7-72541

  The present invention has been made in view of the above-described conventional problems, and it is an object of the present invention to provide an air cover that is miniaturized and that reliably prevents dust and the like from adhering to glass by preventing the generation of eddy currents. And

In order to solve the above-described problem, an air cover according to the present invention includes:
In an air cover including a casing that is mounted on the mounted body so as to surround the glass of the mounted body and that has an opening provided at an end opposite to the mounted body.
A glass-side air passage provided between the glass of the casing and the opening and extending obliquely in a direction intersecting the axis of the casing from the opening side toward the glass side;
An opening-side air passage provided on the opening side of the casing and extending obliquely in a direction intersecting the axis of the casing from the glass side toward the opening side;
Have

  By the said structure, the gas discharged toward the glass from the glass side ventilation path reflects with glass, and advances to the direction spaced apart from glass. Therefore, it is possible to prevent the vortex from being generated on the surface of the glass and to prevent the dust sucked into the vortex from adhering to the glass. Further, since the gas is blown directly onto the glass, even if dust adheres to the glass, it can be removed by the gas. Furthermore, by discharging gas from the opening-side air passage toward the outside of the opening, it is possible to prevent dust from flowing inward from the outside of the casing through the opening and to prevent dust from adhering to the glass. . Since the casing is mounted on the mounted body so as to mainly surround the glass, the air cover can be reduced in size as compared with the configuration in which the casing covers the entire mounted body.

The casing is
An outer casing to be mounted on the mounted body;
An inner casing fitted into the outer casing;
A cover member fitted into an end of the outer casing opposite to the mounted body;
Consists of
The glass-side air passage is provided between an annular wall that projects inward from the inner surface of the outer casing and positions the mounted body, and an end of the inner casing on the glass side,
It is preferable that the opening-side air passage is provided between an inner surface of the cover member and an end portion of the inner casing on the cover member side.

The glass side air passage is
An outer casing-side inclined surface that is formed on the inner periphery of the annular wall and reduces in diameter from the opening side of the outer casing toward the glass side;
An inner casing-side first inclined surface that is formed on the outer periphery of the glass-side end of the inner casing and has a diameter that decreases from the opening side of the outer casing toward the glass side and faces the outer casing-side inclined surface;
It is preferable to be provided between.
By the said structure, the structure of a glass side ventilation path can be simplified and manufacturing cost can be reduced.

It is preferable that the said glass side ventilation path is provided in the perimeter around the axis line of the said casing.
Thereby, gas can be sprayed uniformly on glass and generation | occurrence | production of the eddy current by the atmospheric | air pressure becoming non-uniform | heterogenous can be suppressed.

The opening side air passage is
A cover member-side inclined surface formed on the inner surface of the cover member and having a diameter reduced from the glass side toward the opening side of the outer casing;
An inner casing side second inclined surface that is formed on the outer periphery of the end portion of the inner casing on the cover member side, and that is reduced in diameter from the glass side toward the opening side of the outer casing and is opposed to the cover member side inclined surface;
It is preferable to be provided between.
By the said structure, the structure of a glass side ventilation path can be simplified and manufacturing cost can be reduced.

The opening-side air passage is preferably provided on the entire circumference around the axis of the casing.
Thereby, gas can be sprayed uniformly on glass and generation | occurrence | production of the eddy current by the atmospheric | air pressure becoming non-uniform | heterogenous can be suppressed.

The inner casing is preferably arranged to be movable in the axial direction.
By moving the inner casing, the distance between the outer casing side inclined surface and the inner casing side first inclined surface constituting the glass side air passage, and the cover member side inclined surface and the inner casing constituting the opening side air passage The distance between the side second inclined surface can be adjusted. Accordingly, it is possible to adjust the flow rate and the wind pressure of the gas discharged from the glass side air passage and the opening side air passage.

  According to the present invention, the gas discharged from the glass side air passage toward the glass is reflected by the glass and proceeds in a direction away from the glass. Therefore, it is possible to prevent the vortex from being generated on the surface of the glass and to prevent the dust sucked into the vortex from adhering to the glass. Further, since the gas is blown directly onto the glass, even if dust adheres to the glass, it can be removed by the gas. Furthermore, by discharging gas from the opening side air passage toward the outside of the opening, dust is prevented from flowing from the outside of the outer casing to the inside through the opening, and dust is prevented from adhering to the glass. it can.

The exploded sectional view of the air cover concerning the embodiment of the present invention. Sectional drawing which shows the state which mounted | wore the mounting body to the air cover which concerns on embodiment of this invention. The partial expanded sectional view of FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

  As shown in FIG. 1, the air cover 10 according to the present embodiment includes an outer casing 11, an inner casing 31 fitted into the outer casing 11, and a cover member 41 fitted into an end of the outer casing 11 on the opening 12 side. And. The outer casing 11, the inner casing 31, and the cover member 41 constitute a casing. Hereinafter, the direction (indicated by arrow A in FIG. 1) in which the inner casing 31 and the cover member 41 are fitted into the outer casing 11 is referred to as the back side, and the direction opposite to the back side is referred to as the front side.

  As shown in FIG. 2, the outer casing 11 is mounted on the mounted body 61 so as to surround the glass 63 of the mounted body 61. Here, the mounted body 61 is, for example, a surveillance camera. The mounted body 61 includes a cylindrical casing 62 and a glass 63 disposed at an end of the casing 62, and takes an image through the glass 63. The mounted body 61 is not limited to a monitoring camera, and may be a laser transmitter, a sensor or tank, a furnace viewing window, or the like. The casing 62 is not limited to a cylindrical shape as long as the outer casing 11 can be mounted, and may be a hollow quadrangular prism or a hollow polygonal shape.

  Returning to FIG. 1, the outer casing 11 has a cylindrical shape, throttle valve mounting holes 14 b and 14 a and an annular wall 17 formed in this order from the opening 12 on the near side toward the back end on the opposite side of the opening 12. And an inner circumferential groove 21 and a screw hole 24.

  The throttle valve mounting holes 14a and 14b are formed at equal intervals at three locations around the circumference, respectively. Throttle valves 15a and 15b for sending gas to the inside of the outer casing 11 are mounted in the throttle valve mounting holes 14a and 14b, respectively.

  The annular wall 17 is provided at a substantially central portion in the longitudinal direction of the outer casing 11 and protrudes inward from the inner surface of the outer casing 11. On the inner periphery of the annular wall 17, an outer casing-side inclined surface 18 that is reduced in diameter from the near side toward the far side (arrow A direction) is formed.

  The inner circumferential groove 21 is formed on the entire inner surface of the outer casing 11 and is fitted with an O-ring 22 made of an elastic member. When the outer casing 11 is mounted on the mounted body 61, the O-ring 22 seals between the inner surface of the outer casing 11 and the outer surface of the housing 62 of the mounted body 61.

  The screw holes 24 are formed at equal intervals at four locations around the circumference. A screw 26 for fixing a fixing piece 25 for removably fixing the mounted body 61 to the inner periphery of the outer casing 11 is screwed into the screw hole 24.

  The inner casing 31 has a cylindrical shape with a smaller diameter than the outer casing 11. The inner casing 31 includes a flange 32 formed at one end on the near side, an inner casing side first inclined surface 33 formed at the other end on the back side, and a protruding wall 36 formed at a substantially central portion in the longitudinal direction. It has.

  The flange portion 32 is formed at the front end portion of the inner casing 31 and protrudes outward. On the outer periphery of the front side end portion of the collar portion 32, the inner casing side second diameter is reduced from the back side toward the front side (the direction opposite to the arrow A direction) and is opposed to a cover member side inclined surface 42 described later. An inclined surface 34 is formed.

  The inner casing side first inclined surface 33 is formed on the outer periphery of the inner side end portion of the inner casing 31 and is reduced in diameter from the near side toward the inner side (arrow A direction). Opposite.

  The protruding wall 36 has a ring shape that protrudes outward from the outer surface of the inner casing 31. The outer diameter of the protruding wall 36 coincides with the inner diameter of the outer casing 11.

  The cover member 41 has a ring shape that is smaller in diameter than the outer casing 11 and larger in diameter than the inner casing 31. The cover member 41 includes a cover member side inclined surface 42 formed on the inner surface and an outer peripheral groove 45 formed on the outer surface.

  The cover member-side inclined surface 42 is reduced in diameter from the back side toward the front side (the direction opposite to the arrow A direction) and faces the guide member-side second inclined surface 34. The outer peripheral groove 45 is formed on the entire outer surface of the cover member 41, and is mounted with an O-ring 46 made of an elastic member. When the cover member 41 is fitted into the outer casing 11, the O-ring 46 seals between the inner surface of the outer casing 11 and the outer surface of the cover member 41.

  Hereinafter, a method for assembling the air cover 10 will be described.

  First, the inner casing 31 is fitted into the outer casing 11 through the opening 12 from the front side to the back side (in the direction of arrow A) until the inner casing side first inclined surface 33 faces the outer casing side inclined surface 18. Move. At this time, a shim (not shown) is sandwiched between the outer casing side inclined surface 18 and the inner casing side first inclined surface 33, and between the outer casing side inclined surface 18 and the inner casing side first inclined surface 33. A predetermined interval L1 is provided. Then, the inner casing 31 is fixed to the outer casing 11 with screws, and the shim is pulled out. Thereby, as shown in FIG. 3, the glass side ventilation path 51 which has the space | interval L1 between the outer casing side inclined surface 18 and the inner casing side 1st inclined surface 33 is formed. Thus, the structure of the glass side ventilation path 51 can be simplified and the manufacturing cost of the air cover 10 can be reduced. The interval L1 is preferably 0.1 mm to 3 mm, and is 0.4 mm in the present embodiment. This is because if the distance L1 is smaller than 0.1 mm, the gas hardly flows in the glass-side air passage 51. On the other hand, if the distance L1 is larger than 3 mm, the flow rate of the gas discharged from the glass side air passage 51 becomes slow, and the effect of blowing off the dust decreases. The glass-side air passage 51 is provided at a predetermined angle θ1 with respect to the direction in which the axis Lc extends. The angle θ1 is preferably 10 degrees to 30 degrees, for example, and is about 19 degrees in the present embodiment. This is because if the angle θ1 is smaller than 10 degrees, the gas flux hardly flows into the central portion of the glass 63, and the effect of blowing off dust in the central portion of the glass 63 is reduced. On the other hand, if the angle θ1 is greater than 30 degrees, a vortex may be generated between the outer peripheral surface of the glass 63 and the airflow discharged from the glass-side air passage 51.

  Further, between the inner periphery of the outer casing 11 and the outer periphery of the inner casing 31, a first gas that guides the gas sent from the throttle valve 15 a to the glass side air passage 51 between the annular wall 17 and the protruding wall 36. A gas supply chamber 52 is formed.

  Next, the cover member 41 is fitted between the inner periphery of the outer casing 11 and the outer periphery of the inner casing 31 at the end of the outer casing 11 on the opening 12 side, and the cover member-side inclined surface 42 and the inner casing-side second portion are fitted. The inclined surface 34 is opposed. At this time, a shim (not shown) is sandwiched between the cover member side inclined surface 42 and the inner casing side second inclined surface 34, and between the cover member side inclined surface 42 and the inner casing side second inclined surface 34. A predetermined interval L2 is provided. Then, the cover member 41 is fixed to the outer casing 11 with a screw, and the shim is pulled out. As a result, an opening-side air passage 55 having a distance L2 is formed between the cover member-side inclined surface 42 and the inner casing-side second inclined surface 34. The interval L2 is preferably 0.1 mm to 3 mm as in the case of the interval L1, and is 0.4 mm in this embodiment. The opening-side air passage 55 is provided at a predetermined angle θ2 with respect to the direction in which the axis Lc extends. The angle θ2 is preferably, for example, 30 degrees to 60 degrees, and is about 45 degrees in the present embodiment. If the angle θ2 is smaller than 30 degrees, the gas flux discharged from the opening-side air passage 55 is less likely to collect in the central portion of the opening 12, and the effect of preventing dust from flowing from the opening 12 is reduced. is there. On the other hand, when the angle θ2 is greater than 60 degrees, the amount of airflow directed outward from the opening 12 is reduced, and the effect of preventing dust from flowing from the opening 12 is reduced.

  Further, between the inner periphery of the outer casing 11, the outer periphery of the inner casing 31, and the cover member 41, the gas sent from the throttle valve 15 b is provided between the protruding wall 36 and the cover member 41 to the opening-side air passage 55. A guiding second gas supply chamber 56 is formed.

  The inner casing 31 and the cover member 41 are fixed to the outer casing 11 and the inner casing 31 and the cover member 41 are moved along the axis Lc in the outer casing 11 to adjust the distances L1 and L2. The flow rate and wind pressure of the gas discharged from the glass side air passage 51 and the opening side air passage 54 can be adjusted.

  Then, the throttle valve 15a and the throttle valve 15b are mounted in the throttle valve mounting hole 14a and the throttle valve mounting hole 14b of the outer casing 11, respectively, so that the gas can be sent to the first gas supply chamber 52 and the second gas supply chamber 56. Like that.

  Finally, the housing 62 of the mounted body 61 is mounted on the opposite side of the opening 12 from the annular wall 17 of the air cover 10. When the mounted body 61 is positioned in contact with the annular wall 17, the mounted body 61 is prevented from being detached from the outer casing 11 by the fixing piece 25. Thus, since the air cover 10 is mainly mounted on the mounted body 61 so as to surround the glass 63, the air cover 10 can be reduced in size as compared with the configuration in which the outer casing covers the entire mounted body.

  After the air cover 10 is mounted on the mounted body 61, the gas is sent from the throttle valve 15 a to the first gas supply chamber 52. The gas is, for example, air or an inert gas, but is not particularly limited. The gas in the first gas supply chamber 52 is discharged obliquely from the glass side ventilation path 51 toward the glass 63 toward the axis Lc. The discharged gas is reflected by the glass 63 and moves away from the glass 63 in the direction of the opening 12. Therefore, it is possible to prevent the vortex from being generated on the surface of the glass 63 and to prevent the dust sucked into the vortex from adhering to the glass 63. Further, since the gas is blown directly onto the glass 63, even if dust adheres to the glass 63, it can be removed by the gas. Since the glass-side air passage 51 is provided over the entire circumference around the axis Lc, the gas can be uniformly blown onto the glass 63, and the generation of eddy current due to the non-uniform pressure can be suppressed.

  Similarly, gas is sent from the throttle valve 15 b to the second gas supply chamber 56. This gas is discharged obliquely toward the axis Lc to the outside of the opening 12 from the opening-side air passage 55 extending in a direction obliquely intersecting the opening 12. By discharging the gas from the opening-side air passage 55, dust can be prevented from flowing from the outside of the outer casing 11 to the inside through the opening 12, and the dust can be prevented from adhering to the glass 63. Since the opening-side air passage 55 is provided over the entire circumference around the axis Lc, gas can be uniformly blown to the outside of the opening 12, and the generation of vortex flow due to non-uniform air pressure can be suppressed. However, the flow rate of the gas discharged from the opening side air passage 55 is smaller than the flow rate of the gas discharged from the glass side air passage 51. When the flow rate of the gas discharged from the opening side air passage 55 is large, the pressure inside the inner casing 31 becomes lower than the pressure outside the opening 12, and an air flow from the outside of the opening 12 to the inside of the inner casing 31 is generated. This is because dust from the outside may be sucked into the inner casing 31.

  In addition, this invention is not limited to the said embodiment, A various deformation | transformation is possible. With respect to the casing, in the above-described embodiment, the casing is composed of three members including the outer casing 11, the inner casing 31, and the cover member 41. However, the present invention is not limited to this. For example, the casing may be formed of two members by forming the cover member 41 integrally with either the outer casing 11 or the inner casing 31. Further, it is possible to adopt a configuration in which only one glass-side air passage 51 and only the opening-side air passage 55 are provided in this casing.

  Moreover, although the gas discharged from the opening side ventilation path 55 was discharged diagonally toward the axis Lc outside the opening 12, it is not limited to this. A groove or a rib may be provided on the inner surface of the opening side air passage 55 so as to extend obliquely from the front side to the back side in a plane parallel to the opening side air passage 55. Thereby, the swirl | vortex flow which goes to the axis line Lc can be discharged to the outer side of the opening 12, turning around the axis line Lc from the opening side ventilation path 55. FIG.

10 Air cover 11 Outer casing (casing)
12 opening 17 annular wall 18 outer casing side inclined surface 31 inner casing (casing)
33 Inner casing side first inclined surface 34 Inner casing side second inclined surface 41 Cover member (casing)
42 Cover member side inclined surface 51 Glass side ventilation path 55 Opening side ventilation path 61 Attachment object 63 Glass

Claims (7)

In an air cover including a casing that is mounted on the mounted body so as to surround the glass of the mounted body and that has an opening provided at an end opposite to the mounted body.
A glass-side air passage provided between the glass of the casing and the opening and extending obliquely in a direction intersecting the axis of the casing from the opening side toward the glass side;
An opening-side air passage provided on the opening side of the casing and extending obliquely in a direction intersecting the axis of the casing from the glass side toward the opening side;
An air cover characterized by comprising: The casing is
An outer casing to be mounted on the mounted body;
An inner casing fitted into the outer casing;
A cover member fitted into an end of the outer casing opposite to the mounted body;
Consists of
The glass-side air passage is provided between an annular wall that projects inward from the inner surface of the outer casing and positions the mounted body, and an end of the inner casing on the glass side,
The air cover according to claim 1, wherein the opening-side air passage is provided between an inner surface of the cover member and an end portion of the inner casing on the cover member side. The glass side air passage is
An outer casing-side inclined surface that is formed on the inner periphery of the annular wall and reduces in diameter from the opening side of the outer casing toward the glass side;
An inner casing-side first inclined surface that is formed on the outer periphery of the glass-side end of the inner casing and has a diameter that decreases from the opening side of the outer casing toward the glass side and faces the outer casing-side inclined surface;
The air cover according to claim 2, wherein the air cover is provided between the air covers.   The air cover according to any one of claims 1 to 3, wherein the glass-side air passage is provided on an entire circumference around an axis of the casing. The opening side air passage is
A cover member-side inclined surface formed on the inner surface of the cover member and having a diameter reduced from the glass side toward the opening side of the outer casing;
An inner casing side second inclined surface that is formed on the outer periphery of the end portion of the inner casing on the cover member side, and that is reduced in diameter from the glass side toward the opening side of the outer casing and is opposed to the cover member side inclined surface;
The air cover according to claim 2, wherein the air cover is provided between the air covers.   The air cover according to any one of claims 1 to 5, wherein the opening-side air passage is provided on an entire circumference around an axis of the casing.   The air cover according to claim 2, wherein the inner casing is disposed so as to be movable in an axial direction.

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