JPH0717032Y2 - area sensor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to an area sensor including a plurality of light projecting portions or light receiving portions.

(Prior Art) This type of sensor includes a light projector including a plurality of light projecting units in a row, and a light receiver including light receiving units arranged in a line corresponding to each light projecting unit one to one. To be done. The light emitter and the light receiver are installed at a distance from each other, and when an object enters a detection area including a plurality of optical axes from each light emitter to each light receiver,
The presence of an object is detected as one or more optical axes are obstructed by the object. In this configuration, the detection area of the object is determined by the number of optical axes, so it is desirable to be able to increase or decrease the number of optical axes according to the application.

In order to meet such demands, for example, Jitsuko Sho 53-3.
There is a unit combination type area sensor disclosed in Japanese Patent No. 4610. As shown in FIG. 9, this constitutes a sensor unit 2 provided with one light emitting portion or light receiving portion 1, and the sensor units 2 having the required number of optical axes are screwed to the substrate 3, and each sensor unit is attached. The two are connected to each other by a connector 4.

(Problems to be solved by the invention) However, in the above configuration, each sensor unit 2 must be attached to the substrate 3 one by one, and the connector 4 must be connected one by one, so that assembly work and maintenance work are very difficult. It is troublesome.

On the other hand, it is conceivable that the sensor unit is integrally provided with a connector so that the connection and electrical connection of the respective sensor units can be simultaneously performed by the connector. This is because, by simply connecting the sensor units via the connector, the sensor units can be connected and electrically connected at once, and the assembling work is significantly simplified.

However, this tends to result in insufficient mechanical connection strength, so if an object collides with the product during use and receives an impact, or if the sensor unit case expands or contracts due to thermal expansion, a poor electrical contact will occur at the connector. Occurs, which eventually results in malfunction or undetectability, resulting in low reliability. Since this type of sensor is often used, for example, in a safety device of a press machine, such malfunctions will have serious consequences.

The present invention has been made in view of the above circumstances. Therefore, it is an object of the present invention to provide an area sensor which is easy to assemble and has high reliability while being constructed as a combination type of units.

[Structure of the Invention] (Means for Solving the Problems) An area sensor of the present invention comprises a gutter-shaped guide case,
A plurality of sensor units, each of which has a light projecting portion or a light receiving portion, is inserted from the end face side in the longitudinal direction of the guide case and arranged in a column, and end face portions of the plurality of sensor units in the inserting direction into the guide case. Are provided in each
The present invention is characterized in that the sensor unit and the connector unit that are adjacent to each other in the state of being inserted into the guide case are provided with a connector portion that can be electrically connected to each other.

In addition to the above configuration, a translucent front cover that is insertable from the end face side in the longitudinal direction of the guide case and is arranged so as to collectively cover the front faces of the plurality of sensor units, and the guide case. Is detachably provided at both ends in the longitudinal direction, and is retained in the guide case by being constantly urged to the retaining position by the resilient part formed on at least one side in the mounted state. At the same time, it is preferable to provide a pair of cover stoppers provided so as to be movable from the retaining position to the retracted position against the resilient force of the resilient portion.

Further, when a plurality of sensor units are housed in a guide case to form a sensor, the guide case is fixed to the guide case at both ends in the longitudinal direction, and the sensor unit is sandwiched between other sensor units. It is preferable to provide an elastic body.

(Operation) By inserting the sensor unit into the guide case,
The connector portions of each sensor unit are connected to each other. Moreover, since the plurality of sensor units are arranged in a column, but inserted into the gutter-shaped guide case, the holding action of the guide case holds each sensor unit in a connected state, and the connector unit is damaged by an impact or the like. There is no risk of poor contact.

In addition, if a front cover that covers the front surface of each sensor unit is inserted into the guide case from the end face side of the guide case, maintenance is easier than with a structure in which a cover is provided for each light emitter or light receiver. You will be able to do it.

Furthermore, if the sensor unit is fixed to the guide case at both ends of the guide case, and each sensor unit is provided with an elastic body between the sensor unit and other sensor units, variations in the dimensions of the sensor unit and heat Even if there is expansion, the dimensional fluctuation can be absorbed by the elastic body.

(Embodiment) An embodiment in which the present invention is applied to a light receiver of an area sensor will be described below with reference to FIGS. 1 to 8.

The guide case 11 is manufactured by extrusion molding of aluminum, for example, and has a square gutter shape with a U-shaped cross section. Holding grooves 13 for holding the front cover 12 made of a transparent plastic plate are formed on both left and right side wall portions of the guide case 11.
(See FIG. 3) and mounting holes 14 are formed near the upper and lower ends.

Now, FIGS. 1 and 2 show an example of an area sensor having, for example, six optical axes, both of which include a basic unit 15 and a two-channel end unit 16 which correspond to a sensor unit. Combined.

The basic unit 15 is a plastic unit case that can be inserted into the guide case 11 from its end face side.
Four light-receiving elements 19 each of which constitutes a light-receiving portion are mounted on a circuit board 18 provided with the light-receiving element 17. A large-diameter opening 20 is formed on the front surface of the unit case 17 corresponding to each light-receiving element 19, and a condenser lens 21 is mounted in each opening 20. Further, a cover stopper 22 contacting the front cover 12 from below is integrally provided at the lower end portion of the front surface of the unit case 17, and a cable 23 that bundles the power supply line and the signal line is integrally derived from the center portion of the bottom surface. There is. An elliptical surrounding wall portion 24 is integrally provided on the upper surface of the unit case 17, and a female connector portion 26 attached to an auxiliary substrate 25 is provided inside the inner wall in a protruding state (see FIG. 5). ). Further, an elastic body 27 is provided on the outer side portion of the surrounding wall portion 24.
Are provided so as to be sandwiched between the two-channel end unit 16. A nut 28 for fixing to the guide case 11 is embedded in the lower end of the unit case 17 of the basic unit 15 as shown in FIG.

On the other hand, the 2-channel end unit 16 is also provided with a plastic unit case 29 that can be inserted into the guide case 11 from the end face side thereof. Inside the unit case 29, a circuit board 30 on which two light receiving elements 18 each constituting a light receiving portion are mounted is disposed, and a condenser lens 21 is disposed on the front surface portion like the basic unit 15. There is. Further, an elliptic cylindrical portion 31 into which the surrounding wall portion 24 of the unit case 17 can be fitted is projectingly provided on the lower surface portion of the unit case 29 of the two-channel end unit 16, and the outer peripheral surface of the cylindrical portion 31 is provided. O-ring 32 for sealing with the surrounding wall 24
Is provided. A male connector portion connectable to the female connector portion 27 is provided at the lower end of the unit case 29.
33 is provided, and its connecting pin projects into the cylindrical portion 31. Further, the upper end of the unit case 29 is closed, a mounting hole 34 extending in the lateral direction is formed therein, and a pair of guide grooves 35 extending in the front-rear direction (horizontal direction in FIG. 1) is formed on the upper end surface. (See FIG. 4). This guide groove 35 has a plate-shaped plastic cover stopper.
36 is stored so that it can slide back and forth. The cover stopper 36 is integrally formed with a spring piece 37 that is an elastic portion that abuts the guide case 11, and the entire cover stopper 36 is constantly urged in the left direction in FIG. As a result, the cover stopper 36 is biased to the retaining position that prevents the front cover 12 from retaining upward, and the cover stopper 36 resists the elastic force of the spring piece 37.
By moving 36 to the right in FIG. 1, it is possible to retreat from the retaining position to a position that allows the front cover 12 to be removed upward. In order to prevent the cover stopper 36 from moving further to the right in FIG. 1 from the retaining position, as shown in FIG.
Protrusion 36a is provided on 36, and locking protrusion 38 is attached to unit case 29.
Is provided. This 2-channel end unit
As shown in FIG. 1, nuts 39 for fixing to the guide case 11 are embedded in the upper ends of the 16 unit cases 29. Further, hemispherical projections 40 that are in pressure contact with the front cover 12 are provided on the front surfaces of the unit cases 17 and 29.

In order to assemble the area sensor having the above-mentioned configuration, first, the basic unit 15 is inserted into the guide case 11 in which the mounting hole 14 and the like are cut by cutting it to a required length from the end face side thereof, and then this is inserted. Store in place. Then, the two-channel end unit 16 is inserted into the guide case 11 from the end surface side opposite to the basic unit 15 so as to be press-fitted. As a result, the male connector portion 33 of the two-channel end unit 16 is connected to the female connector portion 26 of the basic unit 15 as shown in FIG.
15, 16 are electrically connected. Then, the guide case 11
From the rear side of the unit, screw the setscrew 41 into the nuts 28 and 39 of the unit cases 17 and 29 to attach the units 15 and 16 to the guide case 11.
Securely fix to. Thereafter, the front cover 12 is inserted into the holding groove 13 of the guide case 11 from the end surface on the side of the end unit 16 while pressing the cover stopper 36 provided on the two-channel end unit 16. When the insertion of the front cover 12 is completed, the cover stopper 36 returns to the retaining position by the elastic force of the spring piece 37, and prevents the cover stopper 36 from coming off. Further, when the front cover 12 is attached, the front cover 12 is pressed forward by the projections 40 projecting from the front surfaces of the unit cases 17 and 29. As a result, the front cover 12 is held in the holding groove of the guide case 11. The front cover 12 is pressed against the front edge of the front cover 13 to prevent rattling of the front cover 12.

As described above, according to the present embodiment, each connector portion 2 can be formed by simply inserting each unit 15, 16 into the guide case 11 at a predetermined position.
6,33 are connected. In addition, since each unit 15 and 16 is housed in the guide case 11 and protected from the surroundings, and the connected state of each connector portion 26 and 33 is maintained, an object collides during use. Even if a shock is applied, there is no risk of loosening in the connected state of the connector parts 26, 33. As a result, malfunctions and undetectability due to poor contact in the connector portions 26, 33 can be prevented, and reliability can be greatly improved compared to conventional products. Moreover, particularly in the present embodiment, each sensor unit 15, 16 is fixed by the set screw 41 at both ends of the guide case 11, and
Since the elastic body 27 located between the sensor units 15 and 16 is provided, even if the dimensions between the sensor units 15 and 16 slightly change due to thermal expansion of the unit cases 17 and 29 and the guide case 11, the elastic body 27 is provided. It can be absorbed by 27. As a result, an unreasonable force acts on the unit cases 17 and 29 to prevent an accident such as damage to the joint portion of the condenser lens 21, and the reliability can be improved also from this aspect. Further, since the guide cases 11 at both ends have a gutter shape, the guide cases 11 can be easily manufactured by cutting an extruded aluminum product into a required size.

Further, since many sensors of this type are used at the manufacturing site, the front cover 12 is liable to be contaminated and the cleaning thereof must be done frequently. When the need for such cleaning occurs, the conventional product shown in FIG.
Disassemble each sensor unit 2 and remove the front cover,
There was the annoyance of having to clean each small front cover with as many optical axes as possible. In contrast,
In this embodiment, since the front cover 12 covers both sensor units 15 and 16 collectively, the cover stopper 36 is retracted against the elastic force of the spring piece 37, and then the front surface is removed. The cover 12 may be pulled out from the guide case 11 and one front cover 12 may be cleaned. Further, since the front cover 12 is configured to be attachable to and detachable from the guide case 11 as described above, it is expected that the front cover 12 may rattle with respect to the guide case 11. However, in this embodiment, in view of this point, since the hemispherical projection 40 is provided on the front surface of each unit case 17, 29, the front cover 12 of the holding groove 13 of the guide case 11 by this projection 40. The rattling of the front cover 12 is suppressed by being pressed against the edge portion.

By the way, in this type of area sensor, since the detection area of an object is determined by the number of optical axes, it is desirable to be able to increase or decrease the number of optical axes according to the application. Although FIG. 1 and FIG. 2 exemplify a configuration having six optical axes, in the case of this embodiment, the option unit shown in FIG. 6 to FIG. Either the axis or the 10 optical axes can be configured. For example, to construct an area sensor with four optical axes, the end cap 42 shown in FIGS. 6 and 7 is attached to the upper surface of the basic unit 15. The end cap 42 is formed with a projection 40, a cylinder 43, a mounting hole 44, a guide groove 45, and the like similar to the cylinder 31 of the two-channel end unit 16 described above. With the attached, the female connector portion 27 of the basic unit 15 is covered by the tubular portion 43. Therefore, the guide case 11 having a length corresponding to the basic unit 15 is manufactured, the basic unit 15 is inserted into the guide case 11, and the end cap 42 in which the cover stopper 36 is attached to the guide groove 45 is manufactured.
Attached to the base unit 15
Inserting 12 into the guide case 11 completes the assembly of the 4-channel area sensor.

In addition to the basic unit 15, a 4-channel expansion unit shown in FIG.
46 and the end cap 42 shown in FIG. 6 is used. 4 above
The channel expansion unit 46 also includes a plastic unit case 47 that can be inserted into the guide case 11 from its end face side, and four light-receiving elements (not shown) are arranged in the unit case 47. Correspondingly, four condenser lenses 21 are provided. 2 at the lower end (right end in the drawing)
The channel end unit 16 is provided with a cylindrical portion 48 and a male connector portion 49, and the upper end portion (the left end portion in the drawing) is provided with a female connector portion 50 like the basic unit 15. Therefore, in order to configure an area sensor with 8 optical axes, a guide case 11 having a length corresponding to the total length of the basic unit 15 and the 4-channel expansion unit 46 is manufactured, and the basic unit 15 and 4-channel are provided inside. Insert the extension unit 46, attach the end cap 42 with the cover stopper 36 attached to the guide groove 45 to the 4-channel extension unit 46, and then insert the front cover 12 of a predetermined size into the guide case 11 to attach each unit 15, 46. Assembly is completed by screwing.

In order to configure an area sensor with 10 optical axes, in addition to the basic unit 15, a 4-channel expansion unit shown in FIG.
46 and the 2-channel end unit 16 shown in FIG. 1 are used in combination. That is, first, the above three units 1
A 2-channel end unit 16 in which a guide case 11 having a length corresponding to the total length of 5,46,16 is manufactured, and a basic unit 15, a 4-channel extension unit 46, and a cover stopper 36 in a guide groove 35 are installed therein. Are inserted in order. Then, the front cover 12 having a predetermined size is inserted into the guide case 11, and the two units 15 and 16 on both end sides are screwed to the guide case 11 to complete the assembly. In this case, the 4-channel extension unit 46 existing in the middle portion is not screwed to the guide case 11, but the two units 15 and 16 located at both ends are provided.
Only screw in. As a result, the degree of freedom in the guide case 11 of the 4-channel expansion unit 46 is left, so that even if the units 15, 46, 16 are expanded or contracted due to dimensional variations or thermal expansion, It is possible to prevent them from being absorbed by the elastic deformation of the elastic body 27 located between them and exerting an unreasonable force on each unit case 17, 29, 47.

In addition, in the above-described embodiment, four examples of the area sensor having 4, 6, 8, and 10 optical axes are shown. However, it is a matter of course that the number of optical axes is not limited to this in the present invention. The fixing means of each sensor unit to the guide case is not limited to screwing as in the above-mentioned embodiment, and the sensor units at both ends are indirectly connected to the guide case by separate parts such as end caps fitted and fixed in the guide case. It may be fixed to.
Further, the number of optical axes for each sensor unit may be one, and the invention can be similarly applied to a projector for an area sensor having a light projecting unit instead of a light receiving unit. The present invention is not limited to the example, and various modifications can be made without departing from the scope of the invention.

[Advantages of the Invention] As described above, the present invention is formed integrally with the end faces in the longitudinal direction of each sensor unit by inserting a plurality of sensor units in a gutter-shaped guide case in a vertical state. Since the connector portions are connected to each other and the sensor units are held in the connected state by the holding action of the guide case, the assembling work is very easy, and the contact failure of the connector portions occurs due to impact or the like. It has an excellent effect that reliability is increased without fear.

Further, in the configuration in which the front cover that collectively covers the front surface of each sensor unit is inserted into the guide case from the end face side of the guide case, further cleaning and the like are required as compared with the configuration in which the cover is provided for each light emitting unit or light receiving unit. Maintenance can be performed easily.

In addition, in a configuration in which the sensor unit is fixed to the guide case at both ends of the guide case and each sensor unit is provided with an elastic body positioned between the other sensor units, the dimensional variation and thermal expansion of the sensor unit may occur. Even if there is such a change, the dimensional variation can be absorbed by the elastic body, the reliability can be further enhanced, and an excessive force can be prevented from acting on the sensor unit.

[Brief description of drawings]

1 to 8 show an embodiment of the present invention. FIG. 1 is a vertical sectional view, FIG. 2 is a front view, FIG. 3 is a plan view, and FIG. 4 is a partial vertical sectional view of a cover stopper portion. 5 and 5 are horizontal sectional views of the female connector portion, FIG. 6 is a vertical sectional view of the end cap, FIG. 7 is the same horizontal sectional view, and FIG. 8 is a front view of the 4-channel expansion unit. FIG. 9 is a front view showing a conventional area sensor. In the drawing, 11 is a guide case, 12 is a front cover, 15 is a basic unit (sensor unit), 16 is a 2-channel end unit (sensor unit), 19 is a light receiving part, 26 is a female connector (connector part), and 27 is An elastic body, 33 is a male connector portion (connector portion), 36 is a cover stopper, and 37 is a resilient portion.

Claims (3)

[Scope of utility model registration request] 1. A gutter-shaped guide case, a plurality of sensor units which are provided with a light projecting portion or a light receiving portion and which are inserted in a longitudinal direction from the end face side in the longitudinal direction of the guide case, and a plurality of these sensor units. An area sensor, which is provided on each end face portion of the sensor unit in the insertion direction into the guide case, and includes a connector portion that is electrically connectable to the adjacent sensor units in the insertion state into the guide case. 2. A gutter-shaped guide case, a plurality of sensor units that are provided with a light projecting portion or a light receiving portion, are inserted from the end face side in the longitudinal direction of the guide case, and are arranged in a tandem manner. Connector portions that are respectively provided on the end surface portions of the sensor unit in the insertion direction into the guide case, and that are electrically connectable to the adjacent sensor units in the insertion state into the guide case, and in the longitudinal direction of the guide case. A translucent front cover that is insertable from the end face side and is arranged so as to collectively cover the front faces of the plurality of sensor units; and detachably provided at both ends in the longitudinal direction of the guide case. Is retained in the guide case by being constantly urged to the retaining position by the resilient part formed on at least one side in the mounted state. An area sensor comprising: a pair of cover stoppers provided so as to be movable from the retaining position to the retracted position against the elastic force of the elastic unit. 3. A plurality of sensor units housed in the guide case are fixed to the guide case at both ends in the longitudinal direction of the guide case, and the sensor unit has an elastic body sandwiched between the other sensor units. The area sensor according to claim 1 or 2, further comprising: