JPH0146805B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a weight sorting machine in which a large number of weighing pans are arranged at equal intervals on an endless chain conveyor, and in particular, a load cell is attached to a fixed hammer-rod scale. This method uses a combination of measurement devices.

[Prior art and problems to be solved by the invention] Conventionally, a method of measuring weight using a load cell is widely and generally known, and it is also known that it can be measured at high speed and with high precision. On the other hand, load cells are sensitive to vibrations, so they have the disadvantage of increasing errors caused by vibrations. The machine generates mechanical vibrations, vibrations of the scale itself, and vibrations due to running friction, so it has the disadvantage of not being able to perform highly accurate sorting. The present invention overcomes the above drawbacks by extremely reducing measurement errors caused by vibrations, and
It is an object of the present invention to enable high speed and high precision sorting.

[Means for solving the problems] In order to achieve the above object, the present invention has taken the following technical means.

That is, in the present invention, in a weight sorting machine in which a large number of weighing trays for placing objects to be sorted on an endlessly running and rotating chain are arranged at equal intervals,
A lever scale is provided in a part along the running track of the weighing pan, and the contact traveling member of the weighing pan runs in contact with a lower side in the traveling direction than a fulcrum of the rattle arranged parallel to the traveling direction in the ratchet scale. A measuring rail of a predetermined length is provided in parallel with the lever, and a load cell is installed below the end of the measuring rail to weigh the load applied to the measuring rail and output an electric signal according to the weighed load. and a synchronization switch that outputs a synchronization signal when the contact traveling member of the weighing pan passes a certain point at the terminal end on the measurement rail, and inputs the electric signal and the synchronization signal,
A calculation device is provided to average the electric signals from the time when the synchronization signal is input until a predetermined time has elapsed, calculate the average value as a weight measurement value, and determine the sorting class of the object to be sorted from this weight measurement value, and calculate the judgment result. The apparatus is configured to sort and discharge objects to be sorted and sort them to predetermined discharge positions based on the following.

In addition, in the present invention, the above-mentioned hammer-rod scale may be partially provided with a roberval mechanism, a balance adjustment weight plate, and a vibration prevention damper.

[Example] Hereinafter, the details of the weight sorter according to the present invention will be described with reference to the drawings.

A first embodiment of the structure in which the weighing tray has a Roberval mechanism shown in FIGS. 1 to 3 will be described. Reference numeral 1 denotes a chain, on which a large number of weighing trays 2 for placing objects to be sorted are attached at equal intervals, and it runs and rotates endlessly. Reference numeral 3 denotes a knife-shaped tongue piece as a contact traveling member attached to one end of the lever of the weighing tray 2 that travels and rotates, and the measuring rail 4
Bearings or rollers may be used instead of this knife-like tongue. The measuring rail 4 is designed to reduce contact friction with the knife-like tongue piece 3 by using piano wire, drill rod, etc., but depending on the case, a synthetic resin tape or a flat plate may be used. Reference numeral 5 indicates a hammer rod scale fixedly provided along a part of the traveling track of the weighing tray 2, and is located lower in the traveling direction than the fulcrum 5b of the hammer rod 5a arranged parallel to the traveling direction (transfer direction of the material to be sorted). A measuring rail 4 is provided on the lever 5a in parallel with the lever 5a on the side, and a spring 6 and a screw type adjustment weight 7 are installed on the lever 5a on the opposite side of the measuring rail 4 (upward side in the direction of movement) with respect to the fulcrum 5b. installed. A constant tension is applied to the spring 6 to maintain the horizontal and balanced balance of the lever 5a. In this way, the weighing pan 2
The spring 6 prevents a large initial vibration when the measuring rail 4 is completely rested on the measuring rail 4. 8 is a load cell provided below the end of the measuring rail 4, and the load cell 8 is loaded onto the measuring rail 4 when the knife-shaped tongue piece 3 of the weighing tray 2 runs in contact with the measuring rail 4. The load is weighed and an electrical signal corresponding to the weighed load is output to a calculation device 27, which will be described later. As the knife-shaped tongue piece 3 of the weighing tray 2 that comes in contact with the measuring rail 4 from its starting end advances to the terminal end, the small vibrations of the measuring rail 4 are gradually attenuated. In order to utilize this function, a synchronization switch 9 is provided at an appropriate position to output a synchronization signal to the calculation device 27 when the knife-like tongue piece 3 of the weighing pan 2 passes a certain point at the terminal end on the measurement rail 4. inputs an electric signal corresponding to the weighed load from the load cell 8 and a synchronization signal from the synchronization switch 9, and waits for a predetermined period of time after the input of the synchronization signal (for example, when the knife-shaped tongue piece 3
The electrical signals (up to the upper end) are averaged and the average value is calculated as a weight measurement value, and the sorting class of the object to be sorted is determined from this weight measurement value.

Next, a second embodiment of the structure shown in FIGS. 4 to 7, in which a weighing tray without a Roberval mechanism is provided, will be described. Reference numeral 10 denotes a chain that runs and rotates endlessly, and a large number of weighing trays 11 for placing objects to be sorted are arranged on the chain 10 at equal intervals via hinges 12. 13 shows sliding rollers as contact running members attached to both left and right sides of the lower sliding portion of the weighing tray 11, and a ball bearing, a non-lubricated bearing, or a knife-shaped tongue piece, roller shaft, etc. is used instead of the roller. Although it runs in contact with the measurement rail 14 provided at the bottom of these passages, it is formed so as to reduce the contact friction with the measurement rail 14. The measuring rail 14 is attached to a lever 15a arranged parallel to the traveling direction in a rattle scale 15 fixedly provided along a part of the travel track of the weighing tray 11, and is attached to a rattle 15a for a predetermined length on the lower side in the traveling direction than the fulcrum 15b. (length within a range that does not cause any problem for continuous weighing) is provided in parallel with the lever 15, and the contact surface of the traveling and rotating weighing tray 11 with the sliding roller 13 is provided with a drill rod, synthetic resin tape, flat plate, etc. to prevent contact friction. The structure is designed to minimize the amount of
The spring 16 of the ramrod scale 15 is attached to the ramrod 15a on the side opposite to the measurement rail 14 with respect to the fulcrum 15b of the ramrod 15a, and is applied with a constant tension, and is attached to the ramrod 15a on the same side as the spring 16 with respect to the fulcrum 15b. Together with the screw type adjustment weight 17, the horizontal and balance of the lever 15a is maintained. In this way, the spring 16 prevents large initial vibrations when the weighing tray 11 is completely placed on the measuring rail 14. 18 indicates a load cell;
The load cell 18 is provided below the terminal end of the measurement rail 14, and receives the load of the weighing tray 11 on which the objects to be sorted are placed, which runs on the measurement rail 14, through the lever 15a, and adjusts the load according to the applied load. The electrical signal is output to the arithmetic unit 27.
Then, as the sliding roller 13 at the bottom of the weighing tray 11 transfers to the starting end on the measuring rail 14 and advances to the terminal end, the small vibrations of the measuring rail 14 are attenuated. When the roller 13 passes a fixed point at the end of the measuring rail 14, a synchronization switch 19 outputs a synchronization signal to the arithmetic unit 27. Similarly to the above, the arithmetic unit 27 inputs the electric signal from the load cell 18 and the synchronization signal from the synchronization switch 19, averages the electric signals from the time when the synchronization signal is inputted until a predetermined time elapses, and calculates an average value. is calculated as a weight measurement value, and the sorting class of the object to be sorted is determined from this weight measurement value, thereby reducing measurement errors due to vibrations, disturbances, etc.

Next, a third embodiment of the structure shown in FIGS. 8 and 9 in which the lever scales 15 and 5 are provided with a balance adjusting weight plate 20 and a vibration prevention damper 21 will be described. The lever scales 5 and 15 are equipped with springs 6 and 16 and screw-type adjustment weights 7 and 17 for horizontal maintenance and balance adjustment, respectively, and furthermore, a roberval mechanism is provided on the levers 5a and 15a, Part of it is a weight plate 2 for balance adjustment.
0 is installed, and this balance adjustment weight pan 2
0 is equipped with a weight that is slightly lighter than the smallest object to be sorted to be placed on the weighing pans 2 and 11, and the load cells 8,
This acts to reduce the load applied to 18. Therefore, even if the material to be sorted has a large weight,
If a weight suitable for the object to be sorted is placed on the balance adjustment weight pan 20, the slight difference in weight between the weight and the object to be sorted will be measured by the load cells 8 and 18, so a light and small load cell can be used. It has the advantage that it can be used, and the sensitivity of measurement obtained from the resolution is improved, and highly accurate weighing can be performed. Reference numeral 21 denotes a vibration prevention damper installed to prevent the adverse effects of vibration of the levers 5a and 15a, and the load cells 8 and 18 are lightweight and compact by applying an air damper or an oil damper.
In order to make better use of the sensitive sensitivity of the load cells, the anti-vibration damper prevents minute vibrations, which are the weak point of the load cells 8 and 18, and enables highly accurate measurements.

Next, FIG. 10 showing the configuration of the electric circuit will be explained. From the amplifier 22, the comparison/judgment circuit 23, the class setting circuit 24, and the counting circuit 26 to the arithmetic unit 27
is configured, and the amplifier 22 is connected to the load cell 8,
The electrical signal outputted by 18 in accordance with the weighing load is amplified and sent to the comparison/judgment circuit 23 . The arithmetic comparison/judgment circuit 23 inputs the amplified signal as well as the synchronization signals from the synchronization switches 9 and 19, and waits for a predetermined period of time after inputting this synchronization signal (for example, when the weighing pan 2 (time from when the sliding roller 13 of the knife-like tongue piece 3 or the weighing tray 11 reaches a certain point at the terminal end on the measuring rails 4, 14 until it reaches the terminal end of the measuring rail 4, 14). The measured signals are averaged and the average value is calculated as the weight measurement value, and measurement error factors such as vibration and disturbance contained in the output of the load cells 8 and 18 are removed, and this weight measurement value is used to set the class. The sorting class of the object to be sorted is determined by comparing it with the sorting class classification value set in advance in the circuit 24. Reference numeral 25 indicates an ejection signal shift device, and the ejection signal shift device 25 moves the material to be sorted whose sorting class has been determined to the position of the ejection device of the corresponding class of the ejection device installed at a predetermined position for each class. A discharge signal is output at the timing when the discharge signal is reached to activate the discharge device of the corresponding class, and the material to be sorted is sorted and discharged by the operation of the discharge device. 26 is a counting circuit that counts the number of objects to be sorted that have been determined by class.

[Effects of the Invention] As described above, the present invention provides a measuring rail parallel to the lever on the lower side of the lever in the traveling direction than the fulcrum of the lever, which is arranged parallel to the traveling direction of the weighing scale. A load cell that weighs the load applied to the measurement rail and outputs an electric signal according to the weighed load is installed below the terminal end of the rail, and the load cell and the lever scale are combined to form a contact running member that runs in contact on the measurement rail. A synchronization switch is provided that outputs a synchronization signal when passing a certain point at the end of the measurement rail, and the electrical signal from the load cell and the synchronization signal from the synchronization switch are input, and the time period starts from the time when this synchronization signal is input. The electrical signals are averaged and the average value is calculated as a weight measurement value, and a calculation device is installed to determine the sorting class of the objects to be sorted from this weight measurement value. Since the weighed load when small rail vibrations are attenuated is averaged and measured, load cell measurement errors due to vibration are removed and the high speed and high accuracy of the load cell can be utilized.
This has the effect of allowing highly accurate sorting.

[Brief explanation of drawings]

The attached drawings all show embodiments of the weight sorting machine according to the present invention, and FIG. 1A shows a weighing device in which a chain-driven weighing tray has a roberval mechanism and a load cell is combined with a fixed hammer rod scale. Figure 1 (b) is a side view of the above structure, and Figure 2 is a side view showing the main parts of a weighing device in which the lever receiving tray has a roberval mechanism and a load cell is combined with the lever balance. Figure 3 is a front view of Figure 2, and Figure 4A is a plan view showing the overall structure of a weight sorter that is a weighing device in which a load cell is combined with a lever scale when the weighing pan does not have a Roberval mechanism. figure,
Figure 4B is a side view thereof, Figure 5 is an enlarged plan view of a portion of the weighing pan without the Roberval mechanism shown in Figure 4B, and Figure 6 is the weighing tray without the Roberval mechanism. FIG. 7 is a front view of FIG. 6, and FIGS. 8 and 9 are the same as FIGS. 6 and 2. FIG. 10 is a side view showing a structure in which a balance adjustment weight pan and a vibration prevention damper are attached to the lever scales shown, respectively, and FIG. 10 is a configuration diagram of an electric circuit. 1, 10... Chain, 2, 11... Weighing tray, 3... Knife-shaped tongue piece as a contact traveling member,
4, 14... Measuring rail, 5, 15... Ram balance,
6,16...Spring, 7,17...Screw type adjustment weight, 8,18...Load cell, 9,19...
Synchronous switch, 12... Hinge, 13... Sliding roller as contact running member, 20... Weight plate for balance adjustment, 21... Damper for vibration prevention, 22...
...Amplifier, 23...Arithmetic comparison judgment circuit, 24...
Class setting circuit, 25...Emission signal shift device, 2
6...Counting circuit, 27...Arithmetic device, 5a, 15
a... Ram, 5b, 15b... Fulcrum.

Claims (1)

[Scope of Claims] 1. In a weight sorting machine in which a large number of weighing trays for placing objects to be sorted on an endlessly running and rotating chain are arranged at equal intervals, a part of the weighing trays along the running track is provided with a weighing tray. A rod scale is provided, and a measuring rail of a predetermined length on which the contact traveling member of the weighing tray runs in contact is provided on the lower side in the traveling direction than the fulcrum of the lever arranged parallel to the traveling direction in the rod scale. and below the terminal end of the measuring rail,
A load cell is provided that weighs the load applied to the measurement rail and outputs an electric signal according to the weighed load, and synchronizes when the contact running member of the weighing tray passes a fixed point at the end of the measurement rail. A synchronization switch that outputs a signal is provided, the electrical signal and the synchronization signal are input, the electrical signals are averaged from the time when the synchronization signal is input until a predetermined time has elapsed, and the average value is calculated as a weight measurement value. 1. A weight sorting machine combining a load cell and a lever scale, characterized in that a calculation device is provided to determine the sorting class of objects to be sorted from weight measurement values, and the objects to be sorted are sorted based on the determination result. 2. A combination of the load cell and the hammer rod scale according to claim 1, characterized in that the hammer rod scale is partially equipped with a roberval mechanism, a weight pan for balance adjustment, and a damper for vibration prevention. Weight sorting machine.