JP6993631B2 - Food tray transport device with tray detection function - Google Patents

Description

The present invention relates to a food tray transport device having a function of transmitting a sensor signal through a food tray separated from a laminated state and detecting whether or not there is only one tray.

The dish-shaped food tray has an upward slope on the entire circumference of the bottom, which is partially or wholly flat, and the entire circumference of the upper end of the slope is outside the entire circumference of the bottom when viewed from above. The dish-shaped food tray is made of PET resin and is transparent. Typical examples are trays and foam trays made of foamed resin with a white or colored pattern. From the balance of cost and functions such as strength and heat insulation, 0.2 to 1 mm for transparent trays and 1 for foam trays. Most of them have a thickness of ~ 5 mm. In addition, for the purpose of improving space saving during storage and reducing transportation costs, the height dimension when two sheets are stacked by their own weight in the direction in which the upper end of the slope is upward and the peripheral shape of the upper end of the slope is aligned is one. In many cases, the height is less than twice the height of the tray, and more specifically, the height is 1.5 times or less. Such trays are generally laminated with about 20 to 100 sheets. It will be delivered in the form of a package in a bag.

When taking out the trays in this laminated state from the bag, the trays may be so close to each other that the trays connected below do not fall even if the upper part of the laminated body is lifted by hand. It is difficult to separate each sheet accurately. Therefore, separation may fail and the tray may not be supplied to the next process, or two or more trays may be separated and supplied to the next process while they are in close contact with each other. It is indispensable to confirm.

Conventionally, a transmissive or reflective optical sensor is arranged in the lateral direction (for example, from the front to the back of a tray transported from right to left) to detect the tray separately and transported on a substantially horizontal plane. The method of doing was common. With this method, the presence or absence of trays can be reliably detected, but it is difficult to detect whether there is one tray or two or more trays are overlapped. The difficult factors are (1) when producing while switching trays with various height dimensions, when the height dimension of one tray A and the height dimension when two trays B are in close contact are almost the same. The difference cannot be detected, and (2) the tray is very lightweight, about a few grams compared to its size, so it shakes when landing on the tray cradle after separation and tends to float from the tray cradle during transportation. For example, the upper end position in the height direction is not stable.

In order to solve these problems, detection using image processing can be considered, but although the solution can be expected, it is expensive and requires a large installation space, and the usage environment of the device is limited, such as not being exposed to water or oil. Therefore, it is not used easily, and in many cases, it is confirmed visually by the operator whether or not there is only one tray.

Japanese Unexamined Patent Publication No. 2004-024165

The problem to be solved is when the food tray transport device separated from the laminated state is produced while switching trays of various height dimensions, or when the posture is not stable due to the tray shaking. It is a point that it cannot be stably detected that there is only one tray.

In a food tray transport device, a transmissive optical sensor or a transmissive ultrasonic sensor is used so that a signal is transmitted from the front side or the back side of the tray separated from the stacked state and the signal transmitted through the tray is received on the opposite side. It has a function of arranging and detecting that there is only one tray at the detection position , and the signal axis of the transmission type optical sensor or the transmission type ultrasonic sensor is arranged so as to be inclined with respect to the vertical direction. The most important feature is that a cover body having an area covering at least the signal transmitting portion or the signal receiving portion of the sensor head when viewed from above vertically is provided above the sensor head arranged below the tray. do.

It is preferable to have an adjusting means for setting the relationship between the received amount and the determination with one tray at the detection position, and the adjusting means is operated by the touch panel provided on the food tray transport device. It is preferable to do so.

It is preferable to dispose the transmission type sensor in the transport path from immediately after the tray is separated from the laminated state to immediately before the food is supplied into the tray .

It is preferable to provide a robot that grips the tray and transports it in the air, and sets the detection position at a position in the middle of the air transport path .

In the food tray transport device of the present invention, since the transmission type sensor is arranged in the stacking direction of the trays, the tray is not affected by the difference in the dimensions of each part such as the height of the tray and the disturbance such as shaking motion. There is an advantage that it can be stably detected as a sheet.

It is a front view of the food tray transporting apparatus of this invention. It is a top view of FIG. It is a top view when the tray smaller than FIG. 2 is used. It is a figure which shows the relationship between the reception amount of a sensor, and the determination of detection. It is a front view which shows an example of the tray in a laminated state.

In the food tray transport device, the purpose of the tray is to detect that there is only one tray without being affected by the dimensions of each part including the height of the tray and the turbulence such as the shaking movement of the tray at the time of detection. By arranging the transmissive sensors in the overlapping direction, it was realized at low cost and space saving.

FIG. 1 is a front view of the food tray transport device of the present invention. Specifically, continuous minced meat sent by a belt conveyor (not shown) arranged above the tray 2 is cut into a fixed size and the tray 2 is used. It is a tray transfer device in the minced meat overlaying device to be supplied inside. The tray 2 is a substantially rectangular shape with rounded corners when viewed from above, and has a dish shape with a slope on the entire circumference of the bottom, which is mostly flat, and the upper end of the slope is substantially on the same plane parallel to the bottom. be. The tray 2 separated from the laminated state by a tray separating device (not shown) is conveyed to the detection position indicated by the thin two-dot chain line in FIG. 2 and stopped. Sensor heads of the transmissive optical sensor 1 are arranged on the front surface side, which is the upper side of the tray 2, and the back surface side, which is the lower side of the tray 2. In this embodiment, the optical sensor of visible light is used by comprehensively judging the availability, cost, and the ease of adjusting the signal axis, and the signal axis of the sensor 1 shown by the thin alternate long and short dash line is the tray 2. The substantially central portion of the bottom portion of the bottom portion was arranged so as to be inclined with respect to the vertical direction and transmitted.

Since the tray 2 is carried on the tray cradle 3 and 4, the cradle 3 and 4 are provided with an opening 7 so as not to block the signal axis of the sensor 1 as shown in FIG. In this embodiment, the cradle 3 also serves as a cover for covering the lower sensor head when viewed from above vertically, and protects the lower sensor head and the signal axis near the sensor head from falling objects such as food. It is preferable in order to avoid erroneous detection due to damage to the sensor head and obstruction of the signal axis by a falling object.

Further, in this embodiment, even if the dimensions of each part of the tray 2 are different, the tray side guide 5 and the side guide of the tray separating device (not shown) are provided so that the central portion of the tray 2 viewed from the upper surface is always in the same position. Because of the configuration, the sensor 1 is convenient because it is in a fixed position even when trays 2 having various dimensions are used. FIG. 3 shows a top view when the tray 2 has a size smaller than that of FIG.

When the tray 2 is conveyed to the detection position and stopped, the number of trays 2 is determined from the received amount of the sensor 1 by a control means (not shown). FIG. 4 shows the relationship between the reception amount of the sensor 1 and the determination after dividing the determination area for the reception amount of the sensor 1 into three. When two or more trays 2 are overlapped, the reception amount of the sensor 1 is significantly attenuated, and when the tray 2 is not at the detection position, the reception amount of the sensor 1 is not attenuated. There is a clear gap between these received amounts and the received amount when there is only one tray 2. For example, the tray 2 is transported in a cycle of 20 to 150 times per minute, and the turbulence such as shaking continues even after the tray 2 is stopped. Even if the received amount varies, it does not exceed the gap, so that it is possible to stably detect that there is only one tray 2.

The cause of the variation in the received amount may be a difference depending on the tray manufacturer and type, but in this example, a foam tray for minced meat molded from PSP (polystyrene paper) having a foaming rate of about 10 times is used. Therefore, there is no big difference in the thickness of foam trays for minced meat for the same purpose, even if the manufacturers and varieties are different, for the purpose of giving the same strength and heat insulating performance to competing products and for the convenience of cost. Since the foaming rate and the thickness are close to each other, the signal attenuation of the sensor 1 is also close to each other regardless of the product type. It is possible to stably detect that there is only one tray.

In the visible light sensor used in this embodiment, the amount of attenuation differs greatly between when the tray is light-colored such as white or wood grain and when it is dark-colored such as black. In this case, it is preferable to change the relationship between the received amount and the determination for each tray type by the control means. Therefore, in this embodiment, the touch panel switch provided on the apparatus with one tray at the detection position. An adjustment means for setting the relationship between the received amount and the judgment is provided by pressing. If conditions such as cost and installation space are satisfied, an invisible light sensor may be used to reduce the effect of color, or an ultrasonic sensor may be used to eliminate the effect of color, regardless of the control means. It is also good to use. Further, if an optical sensor is used for a transparent tray, the amount of attenuation is small and the detection stability may be lacking. In such a case, it is effective to use an ultrasonic sensor.

In the apparatus of this embodiment, in order to correspond to trays having different dimensions of each part, the position where the tray is stopped is set between immediately after the tray is separated from the laminated state and immediately before the food is supplied into the tray. The sensor was placed so that the signal axis passes through the center of the tray bottom as the detection position, but in a device where the dimensions of the tray used are substantially constant, the signal axis is not only at the tray bottom but also at the surrounding slopes. It suffices to dispose the sensor so that it penetrates from the front side or the back side to the opposite side, including the guide. It is also possible to move the sensors together and arrange the sensors so that the signal axis passes through a certain position with respect to the tray side. In these cases, it may be detected after the supply is supplied into the tray.

In this embodiment, the tray is detected when it is stopped, but the advantage of the present invention is that it can be stably detected even when the tray is shaking. Therefore, for example, the tray is conveyed at a speed of 100 to 8000 mm per second. It is also good to detect when it is in a moving state. As a means of transporting the tray, in this embodiment, the trays placed on the tray cradle 3 and 4 are pushed by the tray feed claws 6, but the trays are used for various robots such as vertical articulated robots and horizontal articulated robots. It is also possible to grip the robot and transport it in the air without a tray cradle, and set a tray detection position in the middle of the transport to detect the tray. Further, in this embodiment, the case where the feed to the tray is minced meat is shown, but in addition to this, meat such as sliced meat and diced meat, and other foods such as fresh fish and prepared foods in a tray package are supplied. It can also be a thing.

1 Transmission type optical sensor 2 Tray 3 Tray cradle that doubles as the upper cover for the lower sensor 4 Tray cradle 5 Tray side guide 6 Tray feed claw 7 Sensor signal transmission opening of the tray cradle

Claims (5)

It has an upward slope on the entire circumference of the bottom, which is partly or wholly flat, and is dish-shaped with the entire circumference of the upper end of the slope outside the entire circumference of the bottom when viewed from above, with a thickness of 0.2 to 5 mm. In a device for transporting a food tray whose height dimension is less than twice the height dimension of one sheet when two sheets are stacked by their own weight in a direction in which the upper end of the slope is upward and the circumferential shape of the upper end of the slope is aligned. A transmissive optical sensor or a transmissive ultrasonic sensor is arranged so that a signal is transmitted from the front surface side or the back surface side of the tray separated from the stacked state and the signal transmitted through the tray is received on the opposite surface side. It has a function to detect that there is only one sheet at the detection position , and the signal axis of the transmissive optical sensor or transmissive ultrasonic sensor is arranged so as to be inclined in the vertical direction and below the tray. A food tray transport device, characterized in that a cover body having an area covering at least a signal transmitting portion or a signal receiving portion of the sensor head when viewed from vertically above is provided above the sensor head arranged in the above . The food tray transport device according to claim 1, further comprising an adjusting means for setting a relationship between a received amount and a determination in a state where one tray is present at the detection position. The food tray transport device according to claim 2, wherein the adjusting means is operated by a touch panel provided on the food tray transport device. The food tray transport device according to claim 3, wherein a transmission type sensor is provided in a transport path from immediately after the tray is separated from the laminated state to immediately before the food is supplied into the tray. The food tray transport device according to any one of claims 1 to 4, further comprising a robot that grips the tray and transports the tray in the air, and the detection position is set at a position in the middle of the air transport path.

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