JP2531975B2 - Optical sensor for preventing rear-end collision of transport vehicle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention provides a light projecting portion and a light receiving portion at a front portion of a transportation vehicle body supported by guide rails, and a reflector at a rear portion thereof. The vehicle body for transportation is provided with the light beam from the light projecting portion reflected by the reflector of the preceding vehicle body for transportation, the reflected light is received by the light receiving portion, and the vehicle body for transportation is preceded based on the received reflected light. The present invention relates to an optical sensor for preventing a rear-end collision of a transportation vehicle body that detects a distance between the vehicle and the vehicle.

[Conventional technology]

In such an optical sensor used to prevent a rear-end collision of a transport vehicle body, a circular light beam is projected from a light projecting portion provided in the front portion of the transport vehicle body to advance the transport vehicle body. The return reflection light and diffuse reflection light from the reflector provided in the rear part are received by the light receiving part in the front part of the vehicle body, and the distance to the preceding transport vehicle body is detected based on the received reflected light. Was common.

[Problems to be Solved by the Invention]

However, in the above-described conventional optical sensor, since the projection beam from the projection unit spreads in a circular shape, the projection intensity must be increased when the distance from the preceding transport vehicle body increases to some extent. However, the desired distance cannot be detected, the projection unit itself becomes expensive, and the driving cost becomes high.

In order to eliminate this drawback, it is conceivable to reduce the diameter of the projection beam to the smallest possible diameter. In that case, in consideration of the positional deviation from the preceding transport vehicle body, the reflection beam provided at the rear of the transport vehicle body should be considered. As a body, a reflector having a considerably large area is required, and not only the reflector itself becomes expensive, but it may not be possible to provide a reflector with a large area at the rear part depending on the structure and shape of the transportation vehicle body. , There was room for improvement in this respect.

The present invention has been made in view of such a situation, and increases the cost of the light projecting portion, the reflector, etc. by considering the peculiarities of the transportation vehicle body and effectively utilizing the peculiarities. It is an object of the present invention to provide an optical sensor for preventing a rear-end collision of a transportation vehicle body that can reliably detect the distance from the preceding transportation vehicle body without doing so.

[Means for solving the problem]

A first characteristic configuration of a rear-end collision prevention optical sensor according to the present invention is a lateral direction in which the reflector has a width smaller than a vertical height of a rear portion of a transportation vehicle body and a length smaller than a lateral width of a rear portion of the transportation vehicle body. The strip-shaped reflector in the lateral direction is attached to the rear part of the vehicle body for transportation in a state of including the center in the lateral width direction of the rear part in a laterally distributed manner.
The light projecting unit is configured to project the light projecting beam in a strip shape in a direction orthogonal to the reflector, which is elongated in the lateral direction.

A second characteristic configuration is that the reflector is a diffuse reflection type reflector, and the light receiving unit includes a focusing unit that focuses the reflected light from the reflector in a spot shape, and the spot-shaped focusing is performed. That is, a position detection unit that detects the position of the preceding transport vehicle body with respect to the reflector based on light is provided.

A third characteristic configuration is that the light receiving unit is configured to detect the intensity of the reflected light from the reflector.

[Work]

According to the first characteristic configuration of the present invention, the reflector is formed in a strip shape having a width smaller than the vertical height of the rear portion of the transportation vehicle body and smaller than the width thereof in the lateral direction. Needless to say, the reflector can be attached to the rear part, and the total area of the reflector can be reduced to reduce the cost of the reflector.

In addition, this laterally elongated strip-shaped reflector is attached to the rear part of the transport vehicle body in a left-right distributed manner with the center of the rear part in the lateral width direction included, so it is sufficient for positional deviation of the transport vehicle body. Can correspond to. That is, in the transporting vehicle body that is supported and moved by the guide rails, since it is supported by the guide rails, the vertical position shift is relatively small, but at the place where the guide rails are curved, There is a large lateral displacement. However, since the reflector is a strip that is long and narrow in the lateral direction and is attached in a left-right distribution manner including the center of the rear portion of the vehicle body in the lateral width direction, the total area is reduced as described above, but the lateral direction is reduced. It is possible to reliably deal with the positional deviation of.

Further, the light projecting portion is configured so that the projected light beam projects in the lateral direction in the shape of an elongated strip that is orthogonal to the elongated reflector. Therefore, the projected light can be received without extremely increasing the intensity of the projected light. It is possible to maintain the received light intensity at a portion above a predetermined value, and it is possible to sufficiently cope with a small vertical displacement of the transport vehicle body.

According to the second characteristic configuration, the reflector is a diffuse reflection type reflector, the light receiving unit includes a focusing unit that focuses the reflected light in a spot shape, and the position detecting unit is based on the spot-shaped focused light. Since the position of the preceding transport vehicle body with respect to the reflector is detected, the distance to the preceding vehicle body can be detected more reliably without extremely increasing the light projection intensity from the light projecting unit.

According to the third characteristic configuration, since the light receiving unit detects the intensity of the reflected light from the reflector, the preceding vehicle body is detected based on the detected intensity of the reflected light without requiring a special position detecting unit or the like. The distance to can be detected.

〔The invention's effect〕

As described above, according to the present invention, even if the distance from the preceding transport vehicle body is large, a reflector having a comparatively small area is sufficient, and the light projecting section can also provide the light projecting intensity. There is no need to make it extremely large, and while reducing the overall cost, and by effectively utilizing the special characteristics of the transport vehicle body, the distance from the preceding transport vehicle body can be maintained even at the curved portion of the guide rail. We have come to obtain an optical sensor that can detect reliably the rear-end collision of the vehicle body for transportation.

〔Example〕

An embodiment of an optical sensor for preventing a rear-end collision of a transportation vehicle according to the present invention will be described below with reference to the drawings.

As shown in FIGS. 3 and 4, a plurality of vehicle bodies (V) for transportation having a pair of front and rear traveling wheels (1) are movably supported by guide rails (R). The vehicle body (V) is driven by a linear motor so that articles can be conveyed.

The guide rail (R) has a substantially U-shaped cross section, and a groove (2) into which the traveling wheel (1) is inserted is provided in the lower surface of the inner wall of the guide rail (R). A power supply unit (K) for supplying power to the vehicle body (V) on the lateral side surface of the inner wall.
Is provided. Further, a secondary conductor (3) of the linear motor is formed on the lower surface side of the guide rail (R).

The carrying vehicle body (V) is composed of a support frame (4), a main frame (5), and an article support section (6).

The pair of traveling wheels (1) is attached to an intermediate portion in the up-down direction of the support frame (4), and the pair of left and right guide rollers (7) includes an upper end portion of the support frame (4) and the traveling wheels ( It is provided on both front and rear sides of 1). Therefore, the vehicle body (V) is movably supported by the guide rail (R). In addition, (8) in the figure
Is a current collector for the power supply unit (K).

A primary coil (9) is provided on the upper part of the main frame (5) at a position facing the secondary conductor (3). Therefore, the vehicle body (V) can run along the guide rail (R).

Although not described in detail, the article support portion (6) is provided so as to be able to move up and down with respect to the main frame (5), and also, by opening and closing the hanger (10), the article to be conveyed (C) is locked and engaged. It is configured so that it can be freely released.

A main body (S) of an optical sensor is provided at the front end of the main frame (5), and the rear end of the main frame (5) is higher than the vertical height of the rear part of the vehicle body (V). A narrow strip-shaped diffuse reflection type reflector (11) having a small width and a length smaller than the lateral width of the rear portion of the vehicle body (V) has its longitudinal direction along the lateral width direction of the vehicle body, and further, the vehicle body (V). It is attached so as to be divided into right and left parts including the center in the lateral width direction of the rear part.

The main body (S) of the optical sensor will be further described. As shown in FIG. 2, the projector (12) for projecting light onto the reflector (11) of the preceding vehicle body (V) and the reflector. (11)
And a light receiving section (13) for receiving the reflected light from.

The light projecting portion (12) is formed from a cylindrical lens (15) for projecting the light emitting element (14) and its light projecting beam (T) onto the reflector (11) of the preceding vehicle body (V) in the form of a narrow strip. Has become. The longitudinal direction of the projection beam (T) is configured to be vertical. That is, as shown in FIG. 1, the projection beam (T) and the reflector (11) are arranged to cross each other in a cross shape.

The light receiving section (13) is composed of a focusing lens (16) for focusing the diffusely reflected light from the reflector (11) in a spot shape and a position detecting section (17) for detecting the position of the spot light. . That is, the focusing lens (16) corresponds to the focusing unit.

The position detecting section (17) is composed of a position detecting element applying a silicon photodiode, and is configured to detect the one-dimensional position of the received light spot.

That is, the reflector (11) is located at a relatively short distance (A).
In the case of, the light spot is formed at the point (a), and at the position of the long distance (B), the light spot is formed.

Therefore, the distance to the reflector (11), that is, the preceding vehicle body (V) can be detected by detecting the spot position on the position detecting element.

Then, when it is detected that the distance to the preceding vehicle body (V) becomes smaller than the set value, the brake is operated to stop.

Therefore, it is possible to prevent each vehicle body (V) for transportation from colliding with the preceding vehicle body (V).

[Another embodiment]

In the above embodiment, the reflected light is focused in a spot shape and the position of the spot light is detected, but the intensity of the reflected light may be detected. In that case, the reflector (11) may be a diffuse reflection chamber or a recursive reflection type.

Further, in the above-mentioned embodiment, the cylindrical lens (15) is used to make the projection beam (T) into an elongated strip shape, but the constitution of each part such as to make the light emitting element (14) scan vertically Various changes can be made.

It should be noted that reference numerals are added to the claims for convenience of comparison with the drawings, but the present invention is not limited to the structures of the accompanying drawings by the entry.

[Brief description of drawings]

The drawings show an embodiment of an optical sensor for preventing rear-end collision of a transporting vehicle according to the present invention. FIG. 1 is an explanatory view showing the relationship between a projection beam and a reflector, and FIG. 2 shows the structure of an optical sensor. 3 is a side view of the transfer facility, and FIG. 4 is a rear view of the same. (11) …… Reflector, (12) …… Projector, (13) …… Receiver, (16) …… Focusing section, (17) …… Position detector, (T)
...... Light projection beam, (R) …… Guide rail, (V) …… Transport vehicle body.

Claims (3)

(57) [Claims] 1. A light projecting portion (12) and a light receiving portion (13) are provided at a front portion of a transporting vehicle body (V) supported by a guide rail (R), and a reflector (11) is provided at a rear portion thereof. ) Is provided, the projection beam (T) from the light projecting section (12) is reflected by the reflector (11) of the preceding vehicle body (V), and the reflected light is received by the light receiving section (13). What is claimed is: 1. An optical sensor for preventing rear-end collision of a vehicle body for transportation, which receives light and detects a distance to a preceding vehicle body (V) based on the received reflected light, wherein the reflector (11) is a vehicle body for transportation. (V) A narrow strip in the lateral direction having a width smaller than the vertical height of the rear portion and a length smaller than the lateral width of the rear portion of the transport vehicle body (V), and the strip-shaped reflector (11) extending in the lateral direction. The rear part of the vehicle body (V) for transportation is attached in a left-right distribution manner including the center of the rear part in the lateral width direction, and the light projecting part is provided. 12), the projection beam (T) transverse to the elongated said reflector (11) and the transport vehicle collision prevention optical sensor is arranged to projecting the elongated strip in a direction perpendicular. 2. A converging part (16) for converging the reflected light from the reflector (11) in a spot shape, wherein the reflector (11) is a diffuse reflection type reflector. And a position detecting section (17) for detecting the position of the preceding vehicle body (V) with respect to the reflector (11) based on the spot-shaped focused light. Optical sensor to prevent rear-end collision of the vehicle body. 3. The light receiving section (13) is configured to detect the intensity of light reflected from the reflector (11).
An optical sensor for preventing the rear-end collision of the transportation vehicle body described.