JP2009110750A - Multiple optical-axis photoelectric sensor and assembling method for multiple optical-axis photoelectric sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a multiple optical-axis photoelectric sensor capable of simple assembling. <P>SOLUTION: Flange sections arranged on both sides of an optical unit are stored together with a front cover in a storage groove arranged on a main body case. A linear seal member is also stored in a space formed by being surrounded with the storage groove, the flange section, and the front cover, and then, a cross section of the seal member is increased. For example, the cross section of the linear seal member is lessened by extending the linear seal member at the time of its storage, and it is preferable to remove extending force in the seal member after storing it. The seal member fixes the optical unit and the front cover by pushing the optical unit and the front cover against the storage groove. The optical unit is automatically sealed since the optical unit is pushed by the seal member. Consequently, the multiple optical-axis photoelectric sensor can be assembled simply by simultaneously performing fixing and sealing of the optical unit and the front cover without using a screw, a double-faced adhesive, a resin case, or the like. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  In the present invention, a photoelectric element (light emitting element) that emits light and a photoelectric element (light receiving element) that detects light are combined to form a plurality of optical axes. The present invention relates to a multi-optical axis photoelectric sensor to be detected.

  If a photoelectric element (light emitting element) that emits light and a photoelectric element (light receiving element) that detects light are combined and monitored while the light emitted from the light emitting element is detected by the light receiving element, the light is projected. It is possible to immediately detect whether or not an object blocks the optical axis between the element and the light receiving element. Using this principle, a plurality of light projecting elements arranged in a row and a plurality of light receiving elements arranged in a row are combined to form a monitoring region composed of a plurality of optical axes, and the monitoring region is an object. After that, a monitoring system that can immediately detect this is widely used. Such a monitoring system includes a light projecting device that houses a plurality of light projecting elements arranged in a row and emits light, or a light receiving device that houses a plurality of light receiving elements arranged in a row and receives and detects light. The light projecting device and the light receiving device are commonly referred to as “multi-optical axis photoelectric sensors”.

  The multi-optical axis photoelectric sensor is roughly composed of three parts: a main body case, an optical unit, and a front cover. In the optical unit, a plurality of light projecting elements (or light receiving elements) are arranged in a line, and a converging lens is provided corresponding to each light projecting element (or light receiving element). The light emitted from the light projecting element is converted into parallel light by the converging lens, and is converged on the light receiving element by the converging lens and detected on the light receiving device side. The main body case is a long case formed of a rigid member such as metal, and the optical unit is accommodated therein. A large opening window is provided on one side surface of the main body case in the longitudinal direction, and the optical unit housed in the main body case can project or receive light through the opening window. The front cover is made of a transparent material such as acrylic resin and is provided so as to cover the opening window. For this reason, it is possible to prevent a foreign object from jumping from the opening window and damaging the converging lens, the light projecting element (or the light receiving element), etc. of the optical unit.

  When assembling such a multi-optical axis photoelectric sensor, it is necessary not only to assemble the optical unit and the front cover to the main body case, but also to assemble so that the optical unit is sealed in a watertight or oiltight state. This is to avoid such a situation since water, oil, or the like enters the optical unit, so that the converging lens, the light projecting element, the light receiving element, the electronic component, and the like are likely to deteriorate or fail. Corresponding to this, various techniques have been proposed for assembling the optical unit and the front cover to the main body case and keeping the optical unit sealed. For example, after inserting the optical unit into the main body case, the optical unit is screwed from the outside of the main body case in a state where it is applied to the opening window of the main body case. At this time, a seal is provided between the optical unit and the main body case. There has been proposed a technique that enables fixing and sealing of an optical unit at the same time by screwing in a state where a member is sandwiched (Patent Document 1). Alternatively, in order to easily realize the sealing of the optical unit, a technique has been proposed in which the entire optical unit is accommodated in a transparent resin case, and the resin case is mounted in the main body case (Patent Document 2). ).

JP 2000-251595 A JP 2001-155597 A

  However, the proposed conventional technique has a problem that it is still difficult to easily assemble a multi-optical axis photoelectric sensor. That is, in the proposed technique, it is necessary to screw the optical unit to the main body case or to store the optical unit in a transparent resin case, which not only requires time for that, but also increases the number of parts. Further, the front cover needs to be fixed to the main body case by some method such as screwing to the main body case or bonding with a double-sided tape separately from the optical unit. For this reason, in the prior art, it is still not easy to assemble a multi-optical axis photoelectric sensor, and there is a demand for development of a technique that makes it possible to assemble a multi-optical axis photoelectric sensor more easily.

  The present invention has been completed in view of the above circumstances, and an object thereof is to provide a multi-optical axis photoelectric sensor that can be assembled more easily.

In order to solve at least a part of the problems described above, the multi-optical axis photoelectric sensor of the present invention employs the following configuration. That is,
A transparent front cover is provided on one side of a long main body case, and a multi-optical axis photoelectric housing a long optical unit in which a plurality of photoelectric elements are arranged in a row in the main body case. In the sensor
A pair of flange portions provided integrally with the optical unit over the entire length on both sides in the longitudinal direction of the optical unit;
A pair of storage grooves provided in the longitudinal direction inside the mutually facing wall surfaces of the main body case, and formed so as to be able to store the flange portion of the optical unit and the front cover;
Each of the storage grooves includes a linear seal member provided in a state surrounded by the storage groove, the flange portion, and the front cover, and formed of an elastic material.
The pair of storage grooves regulates the optical unit and the front cover so as not to be separated from each other by storing the flange portion of the optical unit and the front cover.
The optical unit and the front cover are fixed to the main body case by being pressed against the storage groove by pressure received from the seal member that increases the cross-sectional area of the optical unit and the front cover.

  In such a multi-optical axis photoelectric sensor of the present invention, flanges are provided on both sides of the optical unit over the entire length of the optical unit, and a pair of storage grooves are provided on the inner side of the mutually opposing wall surfaces of the main body case. In this storage groove, the flange portion of the optical unit and the front cover can be stored. When assembling the multi-optical axis photoelectric sensor, the flange portion and the front cover of the optical unit are stored in the storage groove of the main body case. At this time, the space formed by the storage groove, the flange portion, and the front cover is surrounded. A linear seal member made of an elastic material is also accommodated together. In this manner, after the flange portion, the front cover, and the seal member of the optical unit are stored in the storage groove, the cross-sectional area of the seal member is increased. For example, at the time of storage, the linear seal member is extended and stored in a state where the cross-sectional area is reduced, and then the sealing member tries to return to the original length if the extension force is removed. The cross-sectional area of the seal member can be increased. Alternatively, a chemical reaction is initiated when heat is applied or electromagnetic waves are applied, and a sealing member is formed using an intumescent material that increases in volume, along with the flange portion and the front cover of the optical unit. After the seal member is stored in the storage groove, the cross-sectional area of the seal member may be increased. As described above, since the seal member is stored in a state surrounded by the flange, the front cover, and the storage groove of the optical unit, when the cross-sectional area of the seal member increases, the optical unit and the front cover Is pressed against the storage groove and fixed to the main body case.

  If the multi-optical axis photoelectric sensor is assembled in this way, the seal member is housed in the housing groove of the main body case together with the flange portion of the optical unit and the front cover, and thereafter the cross-sectional area of the seal member is increased. The optical unit and the front cover can be assembled to the main body case only. Further, since the sealing member is strongly pressed against the flange portion, the front cover, and the storage groove of the optical unit, the optical unit is in a sealed state. In the end, in addition to the optical unit, the front cover, and the sealing member, fixing the optical unit and the front cover and sealing the optical unit at the same time without using any special members such as screws, double-sided tape, and resin cases. It can be done easily.

  In addition, since the housing case is provided with storage grooves inside the wall surfaces facing each other, and the optical unit is provided with flanges on both sides, the optical unit is assembled in a state where the multi-optical axis photoelectric sensor is assembled. Is pressed with almost the same force from the seal members on both sides. For this reason, a long optical unit can be automatically positioned with respect to the main body case.

  In such a multi-optical axis photoelectric sensor of the present invention, until the optical unit and the front cover are fixed to the main body case, a tensile force is applied to both ends of the seal member to keep the cross-sectional area reduced. It is particularly desirable to fix the optical unit and front cover to the body case by removing the tensile force.

  In such a method, for example, a seal member can be formed using a proven material whose sealing performance has been sufficiently demonstrated, such as a material used for an O-ring or the like. For this reason, it is possible to easily and surely remove the possibility that the sealing performance is lowered while the multi-optical axis photoelectric sensor is used and the operation of the multi-optical axis photoelectric sensor becomes unstable or breaks down. It becomes.

  In addition, when adopting a method of storing the seal member in the storage groove together with the optical unit and the front cover in a state where the cross-sectional area is reduced by applying a tensile force to both ends of the seal member, Alternatively, a lubricant film may be formed.

  When the seal member is assembled in a state where it is stretched by applying a tensile force to both ends, the optical unit and the optical unit can be obtained by utilizing the fact that the cross-sectional area increases when the seal member tries to return to the original length by removing the tensile force. The front cover is pressed and fixed with a seal member. Therefore, if a lubricant film is formed on the surface of the seal member, the surface of the seal member becomes slippery. Therefore, even if the seal member becomes long, the length of the seal member remains the same over the entire length. You can go back. For this reason, the cross-sectional area can be increased in the same manner at all points, and as a result, the optical unit and the front cover can be pressed uniformly over the entire length of the seal member, and the optical unit can be securely It becomes possible to seal.

  Further, in the multi-optical axis photoelectric sensor of the present invention described above, a protruding wall is provided in the housing groove of the main body case, and the housing groove is divided into a first housing groove and a second housing groove that are parallel to each other. May be. The front cover is housed in the first housing groove, the flange portion of the optical unit is housed in the second housing groove, and the seal member is a space surrounded by the front end portion of the projecting wall, the flange portion, and the front cover. Then, the optical unit and the front cover may be assembled by increasing the cross-sectional area of the seal member.

  As described above, the protruding wall is provided to divide the storage groove into the first storage groove and the second storage groove, the front cover is provided in the first storage groove, and the flange of the optical unit is provided in the second storage groove. If the unit is accommodated, the front cover and the optical unit can be easily accommodated even if the overall length of the multi-optical axis photoelectric sensor is increased. In addition, since a gap corresponding to the thickness of the protruding wall is secured between the front cover and the flange portion of the optical unit, the seal member can be easily accommodated. As a result, the multi-optical axis photoelectric sensor can be easily assembled, which is preferable.

Further, in the present invention, in view of the fact that the front cover and the optical unit of the multi-optical axis photoelectric sensor are assembled to the main body case by a special method, the present invention grasps as a method for assembling the multi-optical axis photoelectric sensor. Is also possible. That is, the assembly method of the multi-optical axis photoelectric sensor of the present invention is:
A transparent front cover is provided on one side of a long main body case, and a multi-optical axis photoelectric housing a long optical unit in which a plurality of photoelectric elements are arranged in a row in the main body case. In the assembly method of the sensor,
The optical unit in which a pair of flange portions are formed over the entire length on both sides in the longitudinal direction, the front cover, the flange portions of the optical unit, and a pair of storage grooves that can store the front cover face each other. Preparing the main body case provided on the inner side and a linear sealing member formed of an elastic material;
A state in which the seal member is housed in each of the housing grooves of the main body case in a state where the cross-sectional area is reduced by applying a tensile force to both ends of the seal member;
With the tensile force applied to the seal member, the flange portion and the front cover are stored in the storage groove, so that the seal member in the storage groove has the storage groove, the flange portion, and the front surface. A step of being surrounded by a cover;
Removing the tensile force applied to the seal member, and fixing the optical unit and the front cover to the main body case.

  In the method of assembling the multi-optical axis photoelectric sensor of the present invention, each of the storage grooves provided in the main body case is stored with a seal member in which a tensile force is applied to both ends and the cross-sectional area is reduced. To do. In order to achieve such a state, the seal member may be stored in the storage groove with a tensile force applied to both ends, or after being stored in the storage groove, a tensile force is applied to both ends of the seal member. It is good also as giving. Next, the flange portion and the front cover are housed in the housing groove while applying a tensile force to the seal member. At this time, the front cover and the flange portion are stored in the storage groove so that the seal member is surrounded by the storage groove, the flange portion, and the front cover. Finally, the optical unit and the front cover are fixed to the main body case by removing the tensile force applied to the seal member. That is, since the sealing member is in a state where the tensile force is applied and the cross-sectional area is reduced, when the tensile force is removed, the cross-sectional area of the sealing member tends to increase. As a result, the optical unit and the front cover are pressed against the storage groove and fixed to the main body case.

  When the multi-optical axis photoelectric sensor is assembled in this way, the optical unit and the front cover can be attached to the main body case and the optical unit can be sealed at a time. Therefore, the multi-optical axis photoelectric sensor can be easily assembled. Is possible. In addition, in such a method, since the seal member can be formed using a material having a proven record, such as a material such as an O-ring, the optical unit can be reliably sealed.

Hereinafter, in order to clarify the contents of the present invention described above, examples will be described in the following order.
A. Overview of multi-axis photoelectric sensor:
B. Structure of the multi-optical axis photoelectric sensor of this example:
C. Assembling method of the multi-optical axis photoelectric sensor of this embodiment:
D. Variations:
D-1. First modification:
D-2. Second modification:

A. Overview of the multi-axis photoelectric sensor:
FIG. 1 is an explanatory diagram showing a rough external shape and usage of a multi-optical axis photoelectric sensor. As shown in the figure, the multi-optical axis photoelectric sensor has a roughly long box shape, and in principle, two multi-optical axis photoelectric sensors 100 and 200 are used in pairs. One of these is used as a multi-optical axis photoelectric sensor 100 that projects light, and the other is used as a multi-optical axis photoelectric sensor 200 that receives light.

  The multi-optical axis photoelectric sensor 100 on the light projecting side includes a main body case 110 having a substantially U-shaped cross section formed by extruding a metal material such as aluminum, and a front cover provided on an opening side surface of the main body case 110. 120, an optical unit 150 housed in the main body case 110, and the like. In the optical unit 150, a plurality of photoelectric elements (light projecting elements) of a type that emits light when supplied with power are arranged in a line at equal intervals. The front cover 120 is made of a transparent material such as acrylic resin. When power is supplied to the optical unit 150, the light emitted from the light projecting element is converged into a beam shape and projected outside the multi-optical axis photoelectric sensor 100 through the front cover 120. ing.

  The multi-optical axis photoelectric sensor 200 on the light receiving side also has substantially the same configuration as the multi-optical axis photoelectric sensor 100 on the light projecting side. That is, the optical unit is housed inside the extruded body case, and a transparent front cover is provided on the opening side surface of the body case. However, the optical unit housed in the multi-optical axis photoelectric sensor 200 on the light receiving side is only incorporated with a photoelectric element (light receiving element) of a type that electrically detects whether or not light is received. It is very different.

  The light-emitting side multi-optical axis photoelectric sensor 100 and the light-receiving side multi-optical axis photoelectric sensor 200 are provided at positions facing each other. A plurality of optical axes are formed between the light receiving elements mounted on the multi-optical axis photoelectric sensor 200 on the side. FIG. 1 shows a state in which a plurality of optical axes L1 to L14 are formed between the multi-optical axis photoelectric sensor 100 on the light projecting side and the multi-optical axis photoelectric sensor 200 on the light receiving side.

  Further, the multi-optical axis photoelectric sensor 100 on the light projecting side and the multi-optical axis photoelectric sensor 200 on the light receiving side are each connected to the control device 10. The control device 10 first activates the optical axis L1, projects light from the light projecting element provided in the multi-optical axis photoelectric sensor 100 on the light projecting side, and provides it on the multi-optical axis photoelectric sensor 200 on the light receiving side. In the received light receiving element, the presence or absence of light is detected. Such an operation is performed in order of the optical axis L1, the optical axis L2, the optical axis L3,... And the optical axis L14 is validated. By repeatedly performing the operation of sequentially enabling the optical axis L1 to the optical axis L14 in this way, monitoring is performed between the multi-optical axis photoelectric sensor 100 on the light projecting side and the multi-optical axis photoelectric sensor 200 on the light receiving side. Form a region. When the object passes through this monitoring area, the light receiving element having the activated optical axis cannot detect light. In the control device 10, it is possible to monitor the presence / absence of an object passing through the monitoring region by determining whether or not light is detected by the light receiving element having the validated optical axis.

  The multi-optical axis photoelectric sensors 100 and 200 are used in a state where the optical axis is formed by facing the light-emitting side multi-optical axis photoelectric sensor 100 and the light-receiving side multi-optical axis photoelectric sensor 200 in this manner, In the multi-optical axis photoelectric sensor 100 on the light projecting side, it is necessary to assemble the optical unit 150 and the front cover 120 in a state of being fixed to the main body case 110. In addition, in order to avoid the optical unit 150 being contaminated with water or oil and deteriorating or failing, the optical unit 150 needs to be assembled in a sealed state in a watertight state or an oiltight state. Such a situation is exactly the same for the multi-optical axis photoelectric sensor 200 on the light receiving side. Therefore, in order to allow the optical unit and the front cover to be easily assembled to the main body case while assembling the optical unit in a sealed state, the multi-optical axis photoelectric sensors 100 and 200 of the present embodiment are as follows. Structure is adopted. As described above, the multi-optical axis photoelectric sensor 100 on the light projecting side and the multi-optical axis photoelectric sensor 200 on the light receiving side differ only in the types of optical elements incorporated in the optical unit. Accordingly, in the following description, the multi-optical axis photoelectric sensor 100 on the light projecting side will be described as an example, but the same description applies to the multi-optical axis photoelectric sensor 200 on the light receiving side.

B. Structure of the multi-optical axis photoelectric sensor of this example:
FIG. 2 is an explanatory diagram showing a rough structure of the optical unit 150 housed in the multi-optical axis photoelectric sensor 100 of the present embodiment. FIG. 2A shows the external shape of the optical unit 150, and FIG. 2B conceptually shows the cross-sectional shape of the optical unit 150. As shown in FIG. 2, the optical unit 150 includes a plurality of photoelectric elements 154 (light projecting elements in this case) mounted on a long substrate 152 at equal intervals, and a light guide on the photoelectric elements 154. The optical member 156 is assembled. The light guide member 156 incorporates a converging lens 156L at a position facing each of the photoelectric elements 154, and converges the light emitted from the photoelectric element 154 (in this case, the light projecting element) as parallel light. It is possible to project. Further, as shown in FIG. 2B, flange portions 156 </ b> F project from the side surfaces on both sides of the light guide member 156.

  FIG. 3 is an explanatory diagram showing the structure of the multi-optical axis photoelectric sensor 100 of the present embodiment. FIG. 3A shows a cross-sectional shape of the main body case 110 in which the optical unit 150 described above with reference to FIG. 2 is incorporated, and FIG. 3B shows the optical unit 150 in the main body case 110. 1 is a cross-sectional view of the multi-optical axis photoelectric sensor 100 configured by incorporating the front cover 120 and the front cover 120. As shown in FIG. 3A, the main body case 110 has a substantially U-shaped cross-sectional shape, and a pair of storage grooves 112 are provided on the inner wall surfaces at positions facing each other. The housing groove 112 accommodates the flange portion 156F of the optical unit 150 and the front cover 120. As described above with reference to FIG. 2, the flange portion 156F is provided so as to protrude from the side surface of the optical unit 150. Therefore, when the optical unit 150 and the front cover 120 are stored in the storage groove 112, FIG. As shown in (b), a space penetrating from the near side to the far side is formed in a portion surrounded by the flange portion 156F, the side surface of the optical unit 150, the front cover 120, and the storage groove 112. The multi-optical axis photoelectric sensor 100 of the present embodiment has a structure in which a linear seal member 170 made of an elastic material such as rubber is provided in this space. Since such a structure is employed, the multi-optical axis photoelectric sensor 100 according to the present embodiment makes it very easy to attach the optical unit 150 and the front cover 120 to the main body case 110 in a state where the optical unit 150 is sealed. It can be assembled. Hereinafter, a method of assembling the multi-optical axis photoelectric sensor 100 by assembling the optical unit 150 and the front cover 120 to the main body case 110 will be described.

C. Assembling method of the multi-optical axis photoelectric sensor of this example:
When assembling the multi-optical axis photoelectric sensor 100, first, the linear seal member 170 is passed through the storage groove 112 provided in the main body case 110, and then a tensile force is applied to the seal member 170 from both sides. I will do it. As described above, since the seal member 170 is formed of an elastic material such as rubber, when a tensile force is applied from both sides, the seal member 170 is stretched to have a reduced cross-sectional area. FIG. 4 shows a state where the seal member 170 is provided in the housing groove 112 of the main body case 110 in a state where the seal member 170 is extended from both sides.

  With the seal member 170 extended and provided in the storage groove 112, the flange portion 156F of the optical unit 150 is inserted into the storage groove 112, and then the front cover 120 is also inserted into the storage groove 112. At this time, since the seal member 170 is stretched to reduce the cross-sectional area, the seal member 170 is formed between the wall surface of the storage groove 112, the flange portion 156F, the side surface of the optical unit 150, and the front cover 120. It is stored in a narrow space. FIG. 5 conceptually shows a state in which the optical unit 150 and the front cover 120 are inserted into the storage groove 112 in a state where the seal member 170 is extended.

  Thus, when the flange portion 156F of the optical unit 150 and the front cover 120 are completely inserted into the housing groove 112 of the main body case 110, the tensile force applied to the seal member 170 is removed. Then, the seal member 170 that has been stretched tries to return to its original length, and the cross-sectional area increases accordingly. However, as described above, the seal member 170 is housed in a narrow space formed between the wall surface of the housing groove 112, the flange portion 156F, the side surface of the optical unit 150, and the front cover 120. The member 170 cannot return to its original cross-sectional area, and presses the flange portion 156F and the front cover 120 against the storage groove 112 to fix the optical unit 150 and the front cover 120 to the main body case 110. In FIG. 6, by removing the tensile force applied to the seal member 170, the cross-sectional area of the seal member 170 increases, and as a result, the seal member 170 presses the front cover 120 and the optical unit 150 against the main body case 110 and fixes them. The state of doing is conceptually shown.

  As described above, the multi-optical axis photoelectric sensor 100 according to the present embodiment is housed in the housing groove 112 in a state where the seal member 170 is stretched by applying a tensile force, and then the optical unit 150 and the front cover 120 are also housed in the housing groove 112. Then, the optical unit 150 and the front cover 120 can be fixed to the main body case 110 only by removing the tensile force applied to the seal member 170. In addition, as shown in FIG. 6, the seal member 170 is strongly pressed against the front cover 120, the wall surface of the storage groove 112, the side surface of the optical unit 150, and the flange portion 156 </ b> F. Therefore, by fixing the optical unit 150 and the front cover 120 to the main body case 110, it is possible to assemble the optical unit 150 into the main body case 110 in a sealed state at the same time.

  In a state where the optical unit 150 is assembled to the main body case 110, the optical unit 150 is pressed by the seal member 170 from both sides with the same force. For this reason, in the multi-optical axis photoelectric sensor 100 of the present embodiment, the optical unit 150 is automatically positioned with respect to the main body case 110, and it is possible to save the trouble of positioning the optical unit 150. Yes.

  In the above-described multi-optical axis photoelectric sensor 100 of the present embodiment, the optical unit 150 and the front cover are utilized by utilizing the fact that the cross-sectional area increases when the stretched seal member 170 returns to the original length. 120 is fixed to the main body case 110, and the optical unit 150 is in a sealed state. Therefore, it is desirable to cover the surface of the seal member 170 with a lubricant so that the movement of the stretched seal member 170 to return to the original length is not hindered. As the lubricant, for example, a fixed lubricating material such as a molybdenum compound may be coated, but most simply, by applying a thin lubricating oil based on silicon or the like on the surface of the seal member 170, It is good also as forming the film of a lubricant. If the lubricant film is formed on the surface of the seal member 170 in this manner, the movement of the stretched seal member 170 to return to the original length is not hindered, so that the seal member 170 becomes longer. However, the cross-sectional area increases uniformly at all locations, and as a result, sufficient sealing performance can be ensured over the entire length of the sealing member 170.

  Further, in the above-described embodiment, it has been described that the cross-sectional area is increased by extending the seal member 170 to reduce the cross-sectional area and removing the tensile force. However, as long as the cross-sectional area of the seal member 170 can be increased, the seal member 170 is not limited to being stretched, and other methods can be used. For example, the linear seal member 170 is formed using a thermal expansion material that starts a chemical reaction and increases in volume when heated to a predetermined temperature. Then, after the seal member 170 is incorporated into the storage groove 112 together with the optical unit 150 and the front cover 120, the seal member 170 may be warmed and volume-expanded. Alternatively, not only the volume expansion but also the seal member 170 whose length is reduced by a chemical reaction and the cross-sectional area is increased accordingly may be used. Further, the seal member 170 is not limited to the case where the chemical reaction is started by heating, but the seal member 170 is formed using a material that starts the chemical reaction by, for example, being exposed to ultraviolet rays or touching a specific gas. Also good. In any case, after the seal member 170 is incorporated into the storage groove 112 together with the optical unit 150 and the front cover 120, the cross-sectional area of the seal member 170 is increased, and the optical unit 150 and the front cover 120 are stored by the seal member 170. By pressing the groove 112, the multi-optical axis photoelectric sensor 100 can be easily assembled.

D. Modified example:
Various modifications exist in the above-described multi-optical axis photoelectric sensor 100 of the present embodiment. Hereinafter, these modifications will be briefly described.

D-1. First modification:
In the above-described embodiment, the description has been given on the assumption that the outer corner portion of the protruding end (the side facing the front cover 120) of the flange portion 156F has an L-shaped shape. If the flange portion 156F has such a shape, when the flange portion 156F and the front cover 120 are housed in the housing groove 112, a space is created in the corner that is cut out in an L shape, and the seal member 170 is placed at this position. Can be stored. However, the shape of the flange portion 156F is not limited to such a shape, and may be various shapes.

  FIG. 7 is an explanatory view illustrating the shape of the flange portion 156F that can be taken by the optical unit 150 of the first modification. The shape of the flange portion 156F may be, for example, a shape obtained by shaving the outer corner on the side facing the front cover 120 substantially obliquely. FIG. 7A shows a state in which the optical unit 150 having the flange portion 156F having such a shape is assembled to the main body case 110 together with the front cover 120. Even when the flange portion 156F has such a shape, if the seal member 170 tries to increase the cross-sectional area, the front cover 120 and the optical unit 150 are pressed to fix them, and the optical unit 150 is fixed. Can be sealed. Further, even when assembled in this way, the optical unit 150 is pressed with substantially the same force from both sides by the seal member 170, so that the optical unit 150 can be automatically positioned. Furthermore, as shown by the white arrow in FIG. 7A, the seal member 170 comes into contact with the front cover 120, the main body case 110, and the optical unit 150 at three locations. One contact point is reduced. Accordingly, the pressing force at each contact point increases, so that the optical unit 150 can be more reliably sealed.

  Alternatively, the flange portion 156F is not recessed, and the outer corner portion on the lower surface side (the side in contact with the flange portion 156F) of the front cover 120 is formed into an L-shaped shape. FIG. 7B shows a state in which the front cover 120 having such a shape is assembled to the main body case 110 together with the flange portion 156 </ b> F of the optical unit 150. As described above, even when the front cover 120 is depressed, if the seal member 170 attempts to increase the cross-sectional area, the front cover 120 and the optical unit 150 are pressed. The optical unit 150 can be sealed while being fixed.

  At this time, the lower surface side of the flange portion 156F (the side opposite to the side facing the front cover 120) may be tapered. FIG. 7C shows a state in which the optical unit 150 in which the lower surface side of the flange portion 156F is tapered is assembled to the main body case 110 together with the front cover 120. In this way, if the lower surface side of the flange portion 156F is tapered, even if the optical unit 150 does not receive a lateral force from the seal member 170, the optical unit 150 is guided into the tapered shape. Can be positioned.

D-2. Second modification:
In the above-described embodiments and modifications, the main body case 110 is provided with the storage groove 112 having a simple cross-sectional shape, and the flange portion 156F of the optical unit 150 and the front cover 120 are stored in the storage groove 112. It was explained as being. However, the cross-sectional shape of the storage groove 112 is not limited to such a simple shape, and can be a more complicated cross-sectional shape.

  FIG. 8 is an explanatory diagram showing a multi-optical axis photoelectric sensor 100 of a second modification example in which the storage groove 112 is formed in a complicated cross-sectional shape. FIG. 8A shows a cross-sectional shape of the main body case 110 in the second modification. As shown in the drawing, in the main body case 110 of the second modified example, a protruding wall 112C is provided at the approximate center of the storage groove 112, whereby the storage groove 112 is connected to the first storage groove 112A and the second storage groove 112A. It is divided into the storage groove 112B.

  FIG. 8B shows a state in which the front cover 120 and the optical unit 150 are assembled to the main body case 110 of the second modified example. As shown in the drawing, in the second modification, the front cover 120 is stored in the first storage groove 112A divided by the projecting wall 112C, and the flange portion 156F of the optical unit 150 is stored in the second storage groove 112B. Stored. Further, the seal member 170 is housed in a space surrounded by the front end portion of the protruding wall 112C, the front cover 120, the flange portion 156F, and the optical unit 150. If the cross-sectional area of the seal member 170 is increased in a state where the front cover 120, the optical unit 150, and the seal member 170 are housed in this manner, the front cover 120 and the optical unit 150 are pressed against the main body case 110. The optical unit 150 can be sealed while being fixed. Further, when the front cover 120 and the optical unit 150 are stored, they can be stored by being guided by the first storage groove 112A and the second storage groove 112B, respectively. Even if the overall length of the unit 150 is increased, the multi-optical axis photoelectric sensor 100 can be assembled more easily.

  In the second modification described above, the cross-sectional shape of the storage groove 112 can be made more complicated. For example, as shown in FIG. 8C, it goes without saying that the depth of the storage groove 112 is different in the middle, and a cross-sectional shape in which a protruding wall 112C is provided in this portion may be used. .

  While various embodiments of the present invention have been described above, the present invention is not limited thereto, and is not limited to the wording of each claim unless it departs from the scope described in each claim. Improvements based on the knowledge that a person skilled in the art normally has can also be added as appropriate to the extent that those skilled in the art can easily replace them.

It is explanatory drawing which showed the outline | summary of the external appearance shape and usage of a multi-optical axis photoelectric sensor. It is explanatory drawing which showed the rough structure of the optical unit 150 accommodated in the multi-optical axis photoelectric sensor 100 of a present Example. It is explanatory drawing which shows the structure of the multi-optical axis photoelectric sensor 100 of a present Example. It is explanatory drawing which showed notionally the mode that the sealing member 170 was accommodated in the main body case 110 in the state extended from both sides. It is explanatory drawing which showed notionally the mode that the optical unit 150 and the front cover 120 were accommodated in the place where the seal member 170 was extended and accommodated. FIG. 6 is an explanatory view showing a state where the front cover 120 and the optical unit 150 are assembled to the main body case 110 by removing the tensile force applied to the seal member 170. It is explanatory drawing which illustrated the shape of the flange part 156F which the optical unit 150 of a 1st modification can take. It is explanatory drawing which shows the multi-optical axis photoelectric sensor 100 of the 2nd modification in which the accommodation groove | channel 112 was formed in the complicated cross-sectional shape.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Control apparatus, 100 ... Multi-optical axis photoelectric sensor, 110 ... Main body case,
112 ... Storage groove, 112A ... First storage groove, 112B ... Second storage groove,
112C ... Projection wall, 120 ... Front cover, 150 ... Optical unit,
152 ... Substrate, 154 ... Photoelectric element, 156 ... Light guide member,
156F ... Flange, 156L ... Converging lens, 170 ... Seal member,
200: Multi-optical axis photoelectric sensor

Claims (5)

A transparent front cover is provided on one side of a long main body case, and a multi-optical axis photoelectric housing a long optical unit in which a plurality of photoelectric elements are arranged in a row in the main body case. In the sensor
A pair of flange portions provided integrally with the optical unit over the entire length on both sides in the longitudinal direction of the optical unit;
A pair of storage grooves provided in the longitudinal direction inside the mutually facing wall surfaces of the main body case, and formed so as to be able to store the flange portion of the optical unit and the front cover;
Each of the storage grooves includes a linear seal member provided in a state surrounded by the storage groove, the flange portion, and the front cover, and formed of an elastic material.
The pair of storage grooves regulates the optical unit and the front cover so as not to be separated from each other by storing the flange portion of the optical unit and the front cover.
The multi-optical axis, wherein the optical unit and the front cover are fixed to the main body case by being pressed against the storage groove by pressure received from the seal member which is intended to increase its own cross-sectional area. Photoelectric sensor. The multi-optical axis photoelectric sensor according to claim 1,
The sealing member is
Prior to fixing the optical unit and the front cover, a tensile force is applied to both ends of the seal member to reduce the cross-sectional area, and the periphery is surrounded by the storage groove, the flange portion, and the front cover. Is stored in the position,
The multi-optical axis photoelectric sensor is a member that presses and fixes the optical unit and the front cover against the storage groove by restoring the cross-sectional area of the seal member when the tensile force is removed. The multi-optical axis photoelectric sensor according to claim 2,
A multi-optical axis photoelectric sensor, wherein a lubricant film is formed on a surface of the sealing member. The multi-optical axis photoelectric sensor according to any one of claims 1 to 3,
A protruding wall that protrudes from each of the storage grooves and divides the storage groove into a first storage groove and a second storage groove that are parallel to each other;
The front cover is stored in the first storage groove, and the flange portion is stored in the second storage groove.
The multi-optical axis photoelectric sensor according to claim 1, wherein the seal member is provided in each of the storage grooves in a state surrounded by a front end portion of the protruding wall, the flange portion, and the front cover. A transparent front cover is provided on one side of a long main body case, and a multi-optical axis photoelectric housing a long optical unit in which a plurality of photoelectric elements are arranged in a row inside the main body case. In the assembly method of the sensor,
The optical unit in which a pair of flange portions are formed over the entire length on both sides in the longitudinal direction, the front cover, and a wall surface where the pair of storage grooves capable of storing the flange portion of the optical unit and the front cover face each other. Preparing the main body case provided on the inner side and a linear seal member formed of an elastic material;
A state in which the sealing member is housed in each of the housing grooves of the main body case in a state where the cross-sectional area is reduced by applying a tensile force to both ends of the sealing member;
With the tensile force applied to the seal member, the flange portion and the front cover are stored in the storage groove, so that the seal member is in the storage groove, the storage groove, the flange portion, and the front surface. A step of being surrounded by a cover;
Removing the tensile force applied to the seal member, and fixing the optical unit and the front cover to the main body case.

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