JP7403484B2 - Article removal device and article inspection system - Google Patents

Description

The present invention relates to an article removal device and an article inspection system, and more particularly to an air blow type article removal device and an article inspection system.

The wind pressure load of compressed air jets (hereinafter simply referred to as air injection pressure) can be used to remove products with poor inspection results from the production line, or to remove products from a specific destination from the product transport line. Air-blow-type article removal devices and article inspection systems that sort and discharge articles to specific delivery lines have been widely used.

In this type of article removal device and article inspection system, air jet pressure cannot be effectively applied to the article to be excluded depending on the shape of the article, transport posture, etc., and accurate removal operation may become difficult.

Therefore, conventional methods have been developed to improve the accuracy of article removal by air injection by estimating the center of gravity of the article while taking into account changes in conveyance interval and orientation due to misalignment of the article on the conveyor. (For example, see Patent Document 1).

In addition, the timing of air injection and the timing of weight measurement are set so that the influence time range in which air injection pressure can affect weight measurement does not overlap with the timing of measurement by the weight measurement unit. There is a device designed to suppress the influence of air injection (for example, see Patent Document 2).

Furthermore, in recent years, the timing of air supply to multiple air nozzles is controlled so that air is injected sequentially from multiple air nozzles adjacent to each other in the conveyance direction. There are methods to ensure exclusion (for example, see Patent Document 3).

Japanese Patent Application Publication No. 2010-179969 Japanese Patent Application Publication No. 2007-136249 JP2018-95327A

However, in the conventional article removal device and article inspection system as described above, while the article to be excluded is being conveyed and passes through a predetermined air blow section on the conveyor, the article is removed by air blow injection from an air nozzle. Because of this, the mainstream method is to start blowing air just before the item to be excluded passes through a predetermined air blow section, and to perform continuous air blowing while the object passes through the predetermined air blow section. , control that utilized the maximum thrust (ejection force) at the start of air blow injection was not performed.

This continuous air blowing tends to cause a drop in pneumatic power from the air source, especially when the supply flow from the air source to other pneumatically operated equipment is large, and in that case, the solenoid valve or regulator for controlling the supply pressure The flow rate of the compressed air passing through the tube tends to become a subsonic flow that does not reach the speed of sound, and even if the supply pressure is at the required pressure level, the flow rate of compressed air supplied to the air nozzle side cannot be secured, and the air blow from the air nozzle There were cases where the ejection force (mass that can be ejected) decreased.

In particular, if the transport speed of the conveyor is slow or depending on the length of the object to be removed, it takes time to pass through the air blow section, so the ejection force from the air blow cannot be efficiently applied to the object to be removed, making it difficult to stabilize the removal operation. This has led to increased costs due to excessive equipment for injecting higher pressure air blow.

The present invention has been made to solve such conventional problems, and it is an object of the present invention to provide an article removal device and an article inspection system that can perform reliable removal operations without increasing costs.

(1) In order to achieve the above object, the article removal device according to the present invention is installed in an article conveyance line, supplies compressed air supplied from an air source to an air nozzle via a solenoid valve, and removes the articles being conveyed. The article removal device removes the article from the article conveyance line by air blow injected from the air nozzle, and opens and closes the solenoid valve in response to a rejection signal inputted to the article to be excluded, and opens and closes the solenoid valve by the opening and closing. The apparatus is characterized by comprising an air blow control means for injecting the air blow to the article to be excluded during a choke flow period in which the compressed air passing therethrough is made sonic.

With this configuration, in the article removal device of the present invention, the period of the article removal operation by air blow is limited to the choke flow period of the solenoid valve, and the pneumatic power (pneumatic energy) supplied from the air source to the article removal device is limited. ) is effectively utilized at a high flow rate, and the drop in flow rate that occurs during continuous air blowing is effectively suppressed. Therefore, under choked flow conditions where the flow rate of the solenoid valve depends on the air pressure supplied from the air source (primary side pressure), sufficient pressure and flow rate of the compressed air flowing from the solenoid valve to the air nozzle are ensured. Therefore, when ejecting compressed air from the air nozzle to remove the object to be excluded from the article conveyance line, the object to be removed can be accurately removed with pneumatic power corresponding to the required ejection force.

(2) In order to achieve the above object, the article inspection system according to the present invention includes a conveyance section that conveys the article along a predetermined conveyance route, and an inspection section that inspects the quality of the article being conveyed according to predetermined inspection conditions. , a sorting unit that removes items to be excluded that correspond to a predetermined inspection result of the inspection unit from among the articles in a direction away from the predetermined conveyance path by air blowing from an air nozzle arranged along the conveyance unit. In the article inspection system, the sorting unit includes a solenoid valve provided between an air source and the air nozzle, and controls opening and closing of the solenoid valve based on a rejection signal according to the inspection result to control the air blow. and a control unit that injects the excluded object to the excluded object during a choke flow period in which the compressed air passing through the solenoid valve is made sonic by opening and closing the solenoid valve. The article may be configured to be injected with the air blow.

With this configuration, in the article inspection system of the present invention, when the sorting section controls the opening and closing of the solenoid valve based on the exclusion signal according to the inspection result of the inspection section and injects air blow to the article to be excluded, the article exclusion operation by air blowing is performed. Since the period is limited to the choke flow period of the solenoid valve, the pneumatic power supplied from the air source to the article removal device is effectively utilized at a high flow rate, and the drop in flow rate that occurs during continuous air blowing is effectively suppressed. be done. Therefore, under choked flow conditions where the flow rate of the solenoid valve depends on the air pressure supplied from the air source, sufficient pressure and flow rate of the compressed air flowing from the solenoid valve to the air nozzle are ensured. Therefore, when ejecting compressed air from the air nozzle to remove articles to be sorted and discharged from the article conveyance line, the articles to be excluded can be accurately removed with pneumatic power corresponding to the required ejection force.

(3) In a preferred embodiment of the present invention, whether or not the time interval between closing the solenoid valve and opening the solenoid valve for eliminating the next article to be excluded has reached a predetermined time. The present invention may be configured to further include a monitoring means for monitoring whether the above-mentioned article is to be excluded, and a transport restriction means for restricting transport of the exclusion target article by the transport section based on the monitoring result of the monitoring means.

In this case, depending on the monitoring result of whether the closing period from when the solenoid valve is closed to when it is opened to remove the next article has reached a predetermined time, the article conveyance by the conveyor section is selectively performed. limited to. Therefore, by setting the predetermined time to be longer than the time required for the article removal operation by air blow and the pneumatic power charge for the next operation, it becomes possible to reliably perform the pneumatic power charge for the next operation for each article removal operation.

(4) In a preferred embodiment of the present invention, the control unit includes condition storage means for storing operating conditions for controlling the timing of opening and closing the solenoid valve according to the mass of the article to be excluded. Good to have.

In this case, using a table or calculation formula stored in the condition storage means, it is possible to quickly and accurately set operating conditions for controlling the timing of opening and closing the solenoid valve according to the mass of the object to be removed, and the object can be removed by air blowing. Even when the period of operation is relatively short, accurate timing settings enable reliable article ejection.

(5) In a preferred embodiment of the present invention, elastic energy is stored in the compressed air immediately after the end of the choke flow period between the air source and the solenoid valve and upstream of the solenoid valve. It is also possible to adopt a configuration in which energy storage means is provided.

In this case, elastic energy can be stored in an energy storage device with a check function upstream of the solenoid valve, such as a long pipe, a filter regulator, or an air tank, as the flow of compressed air stops immediately after the choke flow period ends. , it is possible to exert an effect of extending the choke flow period during the next operation.

(6) A detection sensor that detects the article transported by the transport section upstream of the sorting section, and the control unit controls the timing of opening and closing the solenoid valve based on the detection signal of the detection sensor. It has timing adjustment means for correction.

In this way, the article being transported can be excluded at a more accurate timing as an article to be excluded.

According to the present invention, it is possible to provide an article removal device and an article inspection system that can perform reliable removal operations without increasing costs even if the flow rate of compressed air supplied from an air source fluctuates.

1 is a schematic configuration diagram of an article inspection system including an article removal device according to an embodiment of the present invention. 5 is a timing chart showing the timing of air blow control and air tank filling control when the conveyance interval of articles to be excluded in an air jet sorter in an article inspection system according to an embodiment of the present invention changes. (a) is a graph showing the relationship between air blow time in an air jet sorter and mass that can be sorted and discharged in an article inspection system according to an embodiment, where the vertical axis represents the discharged mass and the horizontal axis represents the air blow time, respectively. (b) is a graph showing the relationship between the air blow time and the air tank filling time for the next operation in the air jet sorter according to one embodiment, where the vertical axis is the air tank filling time and the horizontal axis is the air blow time. Each shows the time. FIG. 3 is a diagram illustrating the difference in air blowing operation time for two types of articles to be excluded with different shapes in the air jet sorter in the article inspection system according to an embodiment of the present invention, (a) is a diagram for excluding a rectangular parallelepiped article; (b) shows the time when an actual product such as a cylindrical product is removed. (a) shows a time change in the upper limit level of the ejection force corresponding to the charge level of the ejection force and the pneumatic power when performing an intermittent air blowing operation with the air jet sorter in the article inspection system according to an embodiment of the present invention. , (b) shows the change over time in the ejection force during continuous air blow operation in the air jet sorter of Comparative Example 1, and (c) shows the ejection force and time during intermittent air blow operation in the air jet separator of Comparative Example 2. It shows the change over time in the upper limit level of ejection force corresponding to the charge level of pneumatic power. (a) is a graph showing a comparison of air blow characteristics of an air jet sorter in an article inspection system according to an embodiment of the present invention under a plurality of different air supply conditions, where the vertical axis represents the supply flow rate and the horizontal axis represents the supply air flow rate. (b) is a graph showing a comparison of the output characteristics of the same air jet sorting machine under different air blowing conditions, the vertical axis is the discharge mass corresponding to the output, and the horizontal axis is the predetermined air pressure. are shown respectively. FIG. 7 is a timing chart showing the timing of air blow control and air tank filling control when the conveyance interval of articles to be excluded in the air jet sorter changes in the article inspection system according to another embodiment of the present invention. FIG.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

1 to 6 show an article inspection system equipped with an article removal device according to an embodiment of the present invention.

First, the configuration will be explained.

As shown in FIG. 1, the article inspection system 1 of this embodiment includes an inspection machine 10 and an air jet sorter 20 that is an article removal device.

The inspection machine 10 includes a conveyance section 11 that conveys a workpiece W, which is an article to be inspected, in a predetermined conveyance direction (X direction in FIG. 1), and an inspection section 12 (article inspection section) that performs a predetermined article inspection. and a control section 13 that controls them.

The conveyance unit 11 is, for example, a belt conveyor type in which an endless conveyor belt is wound around a plurality of rollers, and has a conveyor conveyance path 11a that can convey articles in the X direction.

The inspection section 12 performs, for example, an X-ray inspection, and includes an X-ray generator and an X-ray detector for the inspection. However, the inspection section 12 may perform other inspections, such as metal inspection, mass measurement, shape inspection, etc., or may perform at least one of a plurality of such inspections.

The control unit 13 includes, for example, a transport control means 13a that controls the transport speed and transport interval of the work W by the transport unit 11, and outputs a transport control signal Cb corresponding to the air jet sorter 20, and an output of an X-ray generator. and an inspection control means 13b for controlling the X-ray line detection cycle and inspection period of the X-ray detector according to the conveyance speed of the workpiece W, and various kinds of means for controlling article inspection and article conveyance by both means. An arithmetic control means 13c that calculates control values, a sorting control means 13d that outputs article detection information and inspection results from an article detection sensor (described later) to the air jet sorter 20, and an operation/display that allows operation input and screen display. It includes means 13e.

Specifically, the inspection machine 10 determines whether or not the current workpiece W is being carried in, when a foreign object is detected in the workpiece W by X-ray inspection of the workpiece W being inspected, for example, according to the inspection result in the inspection unit 12. Within a predetermined sorting delay time from the time of detection, a sorting command signal Rj for instructing the sorting and ejection of the work W in which foreign matter has been detected is generated and output to the air jet sorting machine 20 side.

On the other hand, the air jet sorter 20 is installed downstream on the article conveyance line of the inspection machine 10, and has a conveyor section 21 having a conveyor conveyance path 21a located downstream of the conveyor conveyance path 11a of the inspection machine 10. , an air nozzle 22 disposed on the side of the conveyor conveyance path 21a (sorting conveyance path), a solenoid valve 23 that opens and closes the air supply path on the upstream side of the air nozzle 22, and an air nozzle 22 that is supplied to the air nozzle 22 on the upstream side of the solenoid valve 23. A filter regulator 24 (regulator) that controls the pressure of compressed air, that is, the air pressure, to a predetermined pressure, and an air pipe 25 connected to an air source such as an air compressor (not shown) on the upstream side of the filter regulator 24. There is.

Furthermore, the air jet sorter 20 includes a flow meter 26 that detects the flow rate of compressed air supplied from the air source side through the air piping 25, that is, the air supply flow rate Qs, and a flow meter 26 that detects the flow rate of compressed air supplied from the air source side through the air piping 25. A pressure gauge 27 detects the pressure Pj of the compressed air regulated by the filter regulator 24, a sorting command signal Rj from the inspection device 10, and detection information on air supply conditions such as detected values of the flowmeter 26 and pressure gauge 27. A control unit 30 is provided which opens and closes the solenoid valve 23 according to the timing.

The conveyance section 21 is, for example, a belt conveyor type in which an endless conveyor belt is wound around a plurality of rollers, and has a conveyor conveyance path 21a on the right side in FIG. 1 that can convey articles. Of course, this conveyance section 21 is not limited to the belt conveyor type. In addition, on the upstream end side of the conveyance section 21, there is an article detection sensor 32 that detects the leading end of the work W that has been inspected by the inspection machine 10 when it transfers from the conveyor conveyance path 11a onto the downstream conveyor conveyance path 21a. is provided.

The air nozzle 22 is, for example, a flat type, a round type, or a spot type, which is located on the downstream side of the inspection section 12 of the inspection machine 10, and air controlled to a predetermined pressure Pj by a filter regulator 24 is supplied via a solenoid valve 23. When the sorting section Zj is a predetermined conveyance section of the sorting conveyance section 21, an air jet is injected into the sorting zone Zj, so that the workpieces W to be sorted (to be excluded) in the sorting zone Zj are conveyed on the conveyor by the wind pressure load of the air blow. The material is sorted and discharged by blowing it away from the path 21a in the Y direction (downward in FIG. 1) or by slipping it.

When the solenoid valve 23 is opened in response to a valve opening control signal input from the control unit 30, it can allow compressed air supplied from the air source and controlled to a predetermined pressure by the filter regulator 24 to flow into the air nozzle 22. On the other hand, when the valve closes due to no valve opening control signal input from the control unit 30, compressed air supplied from the air source and controlled to a predetermined pressure by the filter regulator 24 can be shut off from the air nozzle 22. ing.

The air piping 25 is connected to an air source such as an air compressor (not shown), and is also connected to a plurality of other devices A and B, each of which has a pneumatic operating part (not shown), and supplies compressed air from the air source to each device. A, B and the article inspection system 1 of this embodiment can be supplied.

The article discharge performance (discharge mass according to pneumatic power) of the air jet sorter 20, which is configured with a pneumatic circuit downstream of the air piping 25, is generally determined according to the supply pressure and flow rate of air. The pressure Ps is set to, for example, 0.4 to 0.9 [MPaG]. In addition, the supply flow rate Qs is a flow rate value (ANR) converted to the atmosphere under standard conditions (20°C, 1 atm, humidity 65%), and is, for example, 400 [L/min], which is a general reference flow level for pneumatic parts. to 500 [L/min] (ANR). Thereby, the air jet sorter 20 supplies compressed air supplied from the air source to the air nozzle 22 via the solenoid valve 23, and removes the work W being transported from the article transport line by air blowing from the air nozzle 22. can be excluded.

The flow meter 26 detects the flow rate of air flowing to the air nozzle 22 side through the filter regulator 24, here the supply flow rate Qs near the branch point of the air piping 25 to the article inspection system 1 side. A device that detects the flow rate by the displacement of a movable pressure-receiving part such as a diaphragm that responds to the differential pressure between the front and rear, or a vortex flowmeter, thermal mass flowmeter, Coriolis flowmeter, etc. placed upstream of the filter regulator 24. be. Note that an air power meter can be used instead of the flow meter 26 and the pressure gauge 27.

When the control unit 13 of the inspection machine 10 inputs a sorting command signal Rj (exclusion signal) corresponding to the inspection result of the inspection unit 12 to the work W to be rejected, the control unit 30 receives the sorting command signal Rj. The electromagnetic valve 23 is configured to be opened and closed by ON/OFF control using a programmable controller, a control board, or the like.

This control unit 30 includes a memory 31 (condition storage means) that stores data tables and calculation formulas for calculating air blow time, which are created based on experimental results in advance according to the mass of the workpiece W to be excluded and transport conditions. The air blowing time required to remove the article is calculated based on the table and calculation formula stored in the memory 31, and the valve opening output corresponding to the air blowing time is applied to the work W up to the sorting section Zj after the inspection. The output is performed at a predetermined timing depending on the conveyance distance and conveyance speed.

Specifically, the control unit 30 first performs an operation for controlling air blow according to the mass of the object to be excluded (for example, M4 in FIG. 3(a)) using a table or an arithmetic expression stored in the memory 31. The air blowing time Ton (sorting operation time) and the air tank filling time Toff, which are the conditions, are set based on tables and calculation formulas stored in the memory 31.

The control unit 30 also inputs a carry-in detection signal from the article detection sensor 32 when each workpiece W is transferred from the conveyor conveyance path 11a of the inspection machine 10 to the conveyor conveyance path 21a of the air jet sorter 20. Alternatively, an article detection signal from an upstream article detection sensor (not shown) that detects article introduction onto the conveyor transport path 11a of the inspection machine 10 is input. Furthermore, when a sorting command signal Rj is input for a workpiece W to be sorted and discharged, the control unit 30 determines the timing at which the workpiece W enters the sorting section Zj on the downstream conveyor transport path 21a and the timing from which the workpiece W enters the sorting section Zj on the conveyor conveyance path 21a on the downstream side. It is now possible to calculate the transport time until exiting the sorting section Zj.

Then, the control unit 30 determines the carry-in detection signal from the article detection sensor 32 or the entry timing of the workpiece W into the sorting zone Zj corresponding to the signal, the sorting delay time Td specific to this system, and the table or table described above. The timing for opening and closing the solenoid valve 23, for example, the valve opening time t12 and the valve closing time t13 in FIG. 2, are set based on the air blow time Ton set by an arithmetic expression or the like.

In addition, the control unit 30 serves as an air blow control means that controls the opening and closing period of the solenoid valve 23 in response to the sorting command signal Rj, and controls the workpieces W to be sorted (to be excluded) in the sorting section Zj to the conveyor conveyance path. When sorting and discharging the workpieces W from above 11a in the Y direction by air blowing, the period of one air blow to the work W to be sorted is limited to a choke flow period during which the compressed air passing through the solenoid valve 23 is made sonic. There is.

The choke flow period referred to here means that the upstream pressure P1 [MPa] of the solenoid valve 23 is higher than the downstream pressure P2 [MPa] of the solenoid valve 23, and the pressure ratio (P2+0.1)/(P1+0. 1) is smaller than the critical pressure ratio, this is the period of the choked flow state in which the flow velocity of air reaches the sonic velocity in the passage inside the solenoid valve 23 which is open.

During this choke flow period, the flow rate of air passing through the internal passage of the solenoid valve 23 depends (proportional) only on the upstream pressure P1 of the solenoid valve 23.

Note that when the pressure ratio (P2+0.1)/(P1+0.1) is larger than the critical pressure ratio, the flow becomes subsonic, and the flow rate of air passing through the inside of the solenoid valve 23 increases not only at the upstream pressure P1 of the solenoid valve 23 but also at the downstream pressure. It also depends on the pressure P2.

Furthermore, the control unit 30 controls the time interval from when the solenoid valve 23 is closed to when the solenoid valve 23 is opened to eliminate the next work W to be excluded, for example, the product pitch equivalent time A1 shown in FIG. A2 and A3 are the required time intervals (for example, the sorting delay time Td + predetermined time in FIG. 2 A w .

Here, the product pitch equivalent times A1 and A2 shown in FIG. In the processing time of , the sorting delay time Td specific to this system starts from the article detection time t11, t21, and the predetermined time necessary for the sorting operation starts from the sorting operation start time t12, t22 after the sorting delay time Td has elapsed. The time is longer than the above-mentioned required time interval, which corresponds to the sum total with time Aw. Therefore, the actual operation permissible times A1' and A2' obtained by subtracting the sorting delay time Td from the required time interval are each longer than the predetermined time Aw, and normal sorting and discharging operation is possible.

Further, as shown in FIG. 2, the predetermined time Aw required for the sorting operation starting from each sorting operation start time t12, t22 is calculated from the sorting operation start time t12, t22 as a reference timing, as shown in FIG. The sorting operation time Ton when starting the sorting operation time Ton, and the tank filling time Toff which is set as the time essential for the supply air pressure power charge of the air source immediately after the sorting operation time Ton (in the figure, the solenoid valve response time & tank filling time time).

Here, the sorting operation time Ton is set to ensure an air blowing time that can ensure an effective choke flow period of the solenoid valve 23 and that can sort and discharge the work W of a predetermined mass to be excluded from the conveyor transport path 21a. This is a possible period, and is calculated based on a data table and calculation formula for air blow time calculation stored in the memory 31 in advance.

In addition, the tank filling time Toff is determined by the pneumatic power supplied from the air source by closing the solenoid valve 23 for each sorting and discharging (article removal) operation in which the solenoid valve 23 is opened for the sorting operation time Ton. This is the pneumatic power charge time to restore the required level, and in this embodiment, the response time of the solenoid valve 23 and the time required to accumulate pressure in the air tank 28 to a predetermined level are based on a data table or calculation formula corresponding to a predetermined filling characteristic. It is calculated as follows. Note that the pneumatic power of the compressed air from the air source side is approximately proportional to the product of the supplied air pressure and the supplied air flow rate at atmospheric temperature, but the kinetic energy of the compressed air in the pneumatic circuit upstream of the solenoid valve 23 is also It can be used for pneumatic power charging to increase the pressure accumulation level of 28.

In this way, the control unit 30 stores in the memory 31 the operating conditions for controlling the timing of opening and closing the solenoid valve 23 according to the mass of the workpiece W to be excluded as a table or arithmetic expression as described below. It serves as a means of storing conditions.

More specifically, it is necessary to blow or slip an ideal rectangular parallelepiped-shaped workpiece W with a discharge mass M [g] in a stationary state by the conveyor belt width Lw [mm] as shown in FIG. 4(a), for example. The air blow time Ton [s] is measured through a preliminary experiment and is stored in the memory 31 as a base characteristic (Ton=xM+y) of the article removal ability by air blow as shown in FIG. 3(a). Note that the Ton characteristic of the mounted product is determined by the test air blow from the inspection machine 10 using this base characteristic.

In addition, as shown in FIG. 4(b), the air blowing time Ton_M[s ] and calculate the following correction coefficient k from the measurement results, the air blow time Ton [s] required for the actual product can be calculated using the actual product characteristics (Ton=xM/k+y ) is relatively corrected as shown by the broken line, and the actual product characteristics of the article removal ability by air blow for each type of workpiece W are used.
k = (Air blow time Ton-y for work mass M of ideal rectangular parallelepiped shape)/(Air blow time Ton_M-y for work mass M of actual product)

Furthermore, for each article removal operation in which the solenoid valve 23 is opened for the sorting operation time Ton, the pneumatic power supplied from the air source side decreases due to the closing of the solenoid valve 23. The pneumatic power charging time required to restore the pneumatic power to the required level was measured through a preliminary experiment, and the results were shown as changes in the air tank filling time Toff according to the air blowing time Ton, as shown in FIG. 3(b). It is stored in the memory 31 as a calculation table or arithmetic expression corresponding to the characteristic. Note that numbers 1, 2, 3, and 4 along the arrows in FIGS. 3(a) and 3(b) indicate the order of data reference. The discharged mass M4 in FIG. 3(a) is, for example, 400 [g], and the filling time Ta3 in FIG. 3(v) is, for example, 0.3 seconds. Furthermore, correction of the Ton characteristic of the sorting operation time in an actual product can be used with or without an air tank.

Therefore, the control unit 30 controls the air blow time Ton corresponding to the sorting operation time Ton and the air tank filling time Toff[ s] can be calculated and set.

In order to perform such a function, the control unit 30 controls the time intervals A1', A2', A3', etc., obtained by subtracting the sorting delay time Td from the product pitch equivalent times A1, A2, A3, to reach a predetermined time Aw. It has the function of a monitoring means to monitor whether or not the system is being monitored.

The function of this monitoring means is the valve closing period ((A1' +Td-T1on), (A2'+Td-T2on)) have reached the predetermined time required to reach the required pneumatic energy storage state ((T1off+Td), (T2off+Td) in FIG. 2). This corresponds to the monitoring function. Note that the predetermined time Aw here changes according to the time T1off, T2off, T3off required for pneumatic power charge (accumulation of pneumatic energy) for the next operation with respect to the article removal operation time T1on, T2on, T3on by air blow. However, since it can be calculated using the table and formula described above, it becomes possible to determine whether or not pneumatic power charging for the next operation can be reliably performed for each article removal operation.

The control unit 30 also functions as a conveyance restriction means that selectively restricts the conveyance of the exclusion target work W by the conveyance units 11 and 21 according to the monitoring results as such a monitoring means.

For example, the control unit 30 determines that the time interval A3' has not reached the predetermined time Aw (A3' is less than Aw), as indicated by "conveyor stop" on the sorting operation time axis in FIG. When the valve closing period from the time t33 when the valve is closed to the time when the valve is opened for the next article removal cannot be secured for a predetermined time Aw, the transport of the work W to be excluded by the transport units 11 and 21 is stopped. ing. Note that, when controlling the conveyance of the work W to be excluded by the conveyance units 11 and 21, the conveyance limiting means may reduce the conveyance speed instead of stopping the conveyance.

Further, the control unit 30 receives a detection signal (“product detection” in FIG. 2) from an article detection sensor 32 that detects the inspected workpiece W on the upstream side of the conveyor conveyance path 21a of the conveyance section 21, and the workpiece W The opening and closing timing of the solenoid valve 23 is adjusted based on setting information such as the product mass value that has been set and input in advance regarding the type of product and the transportation mode such as the packaging style during inspection, and the timing of opening and closing of the solenoid valve 23 is adjusted to adjust the product removal operation time Ton and pneumatic power charge. It also has the function of a timing adjustment means that can correct the required time Toff, and the timing of air blowing to the workpiece W can be corrected according to the transportation form, posture, etc. Of course, the correction table and correction calculation formula can be used.

By the way, in this embodiment, compressed air from an air source on the upstream side of the solenoid valve 23 flows into the air tank 28 via the filter regulator 24, so in cooperation with the filter regulator 24, the air tank 28 23, compressed air immediately after the end of the choke flow period between the air source and the solenoid valve 23 and on the upstream side of the solenoid valve 23 is allowed to flow in and accumulate pressure, thereby accumulating elastic energy. It can function as an energy storage means. However, instead of this air tank 28, by using a long pipe, a pressure accumulator, a filter regulator, etc. as an energy storage means with a check function on the upstream side of the solenoid valve 23, the flow of compressed air immediately after the choke flow period ends. Elastic energy can be accumulated when the valve is stopped, and the choke flow period can be extended during the next operation.

Next, the effect will be explained.

In the article inspection system 1 of the present embodiment configured as described above, during the predetermined time Aw necessary for the sorting operation of each work W to be excluded, not only the air blow time Ton but also the air tank is filled according to the air blow time Ton. By including the time Toff, for each article removal operation for sorting and discharging, the period of article removal operation by air blow from the air nozzle 22 during the sorting operation time Ton is limited to the choke flow period of the solenoid valve 23. In addition, by increasing the flow rate during the Ton time of the solenoid valve 23 and reducing the air consumption according to the operating time ratio (Ton/cycle corresponding to the sorting capacity), a decrease in the supplied pneumatic power is effectively suppressed. Ru.

For example, immediately before the sorting operation start time points t12 and t22 shown in FIG. When the solenoid valve 23 opens, the pressure ratio (P2+0.1)/(P1+0.1) at the gauge pressure becomes smaller than the critical pressure ratio at the sorting operation start time t12 and t22, respectively, and the solenoid valve 23 opens. A choke flow condition occurs in which the air flow velocity reaches the sonic velocity in the internal passage.

During this choke flow period, the flow rate of air passing through the internal passage of the solenoid valve 23 depends (proportional) only on the upstream pressure P1 of the solenoid valve 23, resulting in a substantially constant high flow rate.

Note that the "upper limit level" shown in FIG. 5(a) means that the pneumatic power of the compressed air supplied at the supply flow rate Qs and the supply pressure Ps changes depending on the presence or absence of air blow, and the discharge capacity corresponding to the pneumatic power is determined by the "upper limit level" shown in FIG. This shows that the mass [kg] of the work W to be excluded can vary.

As illustrated in Comparative Example 1 in FIG. 5(b), when continuous air blowing is performed during the sorting operation of the work W to be excluded, the pneumatic power of the compressed air supplied at the supply flow rate Qs and the supply pressure Ps decreases, and the filter Even if the air pressure Pj [MPa] regulated by the regulator 24 is as requested by the setting, for example 0.4 MPa or 0.5 MPa as shown in FIG. Depending on the usage conditions of A and B, the steady air blow flow rate [liter/mm] may range from more than the initial level flow rate qs4 (for example, 400 L/min (ANR)) to a lower flow rate qs3 (for example, 300 L/min (ANR)). ) (indicated by the dotted white circle in FIG. 6(a)).

In addition, when continuous air blowing is performed during the sorting operation of the work W to be excluded, as illustrated as Comparative Example 1 in FIG. 5(b), as shown in FIG. 6(b), air is regulated by the filter regulator 24. Even if the pressure Pj is set to 0.4 MPa or more, the filter regulator 24 restricts the actual flow rate to the solenoid valve 23 side, reducing the air pressure power supplied, and the wind pressure from the air nozzle 22 decreases. The discharged mass according to the load cannot be increased beyond the discharged mass M8 in FIG. 6(b).

Furthermore, as illustrated in Comparative Example 2 in FIG. 5(c), even if the sorting operation time continues for a long time beyond the choke flow period, the sorting operation time ends before the air blow to the next work W to be excluded. Despite this, the tank filling time Toff, which was set as the time essential for charging the supply air pressure power of the air source immediately after the sorting operation time Ton, could not be secured sufficiently to recover the upper limit level, resulting in a decrease in the discharge power. You will end up inviting

In contrast to these Comparative Examples 1 and 2, in this embodiment, the flow meter 26 and the pressure gauge 27 monitor whether the supplied pneumatic power has reached the required level, and the solenoid valve 23 is Under the choked flow condition where the air flow rate depends on the upstream pressure P1 (primary side pressure), the pressure and flow rate of the compressed air flowing from the solenoid valve 23 to the air nozzle 22 are sufficiently ensured.

Therefore, when ejecting compressed air from the air nozzle 22 to remove the workpiece W to be excluded from the conveyor conveyance path 21a, which is the article conveyance line, the workpiece W to be excluded can be accurately removed with pneumatic power corresponding to the required ejection force. A sorting and discharging operation that can be eliminated becomes possible.

Therefore, in this embodiment, unlike Comparative Examples 1 and 2, the flow inside the solenoid valve does not become a subsonic flow and the ejection force decreases, and the ejection force required for removing the article does not decrease. An air blow with a sufficiently large wind pressure load can be generated.

Moreover, in this embodiment, during the predetermined time Aw required for the sorting operation of each work W to be excluded, the solenoid valve 23 is closed immediately after the sorting operation time Ton, and the air is supplied from the air source side to the air jet sorter 20. The pneumatic power generated is charged into the pneumatic circuit on the upstream side of the solenoid valve 23 using the air tank 28 or the like, so that the upper limit level of the ejection force is maintained for each sorting and ejection operation, as shown in FIGS. 5(a) and 6(b). It is possible to increase the ejection force (ejection mass) of intermittent air blow corresponding to the air pressure and air pressure to the required level. As a result, a reliable sorting and discharging operation can be performed within the normal discharging operation time such as the product pitch equivalent times A1 and A2.

In particular, in this embodiment, an air tank 28 having a check function such as a filter regulator 24 is provided between the air piping 25 on the air source side and the solenoid valve 23 and on the upstream side of the solenoid valve 23. , it is possible to store elastic energy in the compressed air immediately after the end of the choke flow period and increase the pneumatic power of the supplied air. Therefore, when opening the solenoid valve 23 corresponding to the sorting operation time Ton of each work W to be excluded, the upstream pressure P1 [MPa] of the solenoid valve 23 is sufficient for the downstream pressure P2 [MPa] of the solenoid valve 23. It is possible to sufficiently secure the period Tch (see FIG. 5(a)) during which the flow rate becomes high and the flow becomes choked in the passage inside the solenoid valve 23, and the flow rate of the solenoid valve 23, which depends on the upstream pressure P1, is sufficient. The flow rate can be set.

Furthermore, in this embodiment, the operating conditions for controlling the opening/closing timing of the solenoid valve 23 can be quickly and accurately set according to the mass of the workpiece W to be excluded, using a table or an arithmetic expression stored in the memory 31. Even though the period of the article ejecting operation by air blowing is limited to the relatively short choke flow time Tch, accurate timing setting makes it possible to reliably eject the articles. Note that the choked flow can be obtained not only by a solenoid valve but also by an air nozzle such as a tapered nozzle or a tapered-divergent nozzle (so-called Laval nozzle) in which the cross-sectional area A of the air nozzle's injection port is sharply reduced. Therefore, the acoustic effect of choked flow can be obtained by either or both of the solenoid valve 23 and the air nozzle 22.

Furthermore, elastic energy is stored in energy storage means with a check function on the upstream side of the solenoid valve 23, such as a long pipe, a filter regulator, an air tank 28, etc., when the flow of compressed air stops immediately after the choke flow period ends. This makes it possible to extend the choke flow period during the next operation. Therefore, this embodiment is useful for the present embodiment in which the inspection section 12 performs X-ray inspection and other inspections described above. It is also useful when the mass is measured based on X-ray transmission density data of an inspection image, instead of using a load sensor.

In addition, the control unit 30 corrects the timing of opening and closing the solenoid valve 23, so that the sorting and discharging operation can be performed at more accurate timing depending on the transportation form of the workpiece W being transported, etc., and a reliable removal operation can be performed. It becomes a possible goods inspection system.

As described above, in this embodiment, even if the supply flow rate Qs of compressed air from the air source fluctuates, the article inspection system 1 includes the air jet sorter 20 that can perform a reliable removal operation without increasing costs. This is something that can be provided.

Note that in this embodiment, the mass of the work W is a known parameter that can be grasped by inputting settings, but if the inspection machine 10 has a mass measurement function, a sorting operation according to the weight value of each work W may be performed. Variable control of the time Ton and tank filling time Toff is possible. The following such embodiment will be described.

(Other embodiments)
FIG. 7 shows the control timing of the air jet sorter in the article inspection system according to another embodiment of the present invention.

The present embodiment is similar to the first embodiment in that the inspection machine 10 includes a transport section 11, an inspection section 12, and a control section 13, but the transport section 11 uses a load (not shown) to calculate the weight of the transported article. The inspection unit 12 is composed of a weighing conveyor that can be applied to a sensor, and has a function of weighing the mass of the workpiece W on the conveyor transport path 11a using the load sensor and determining whether the weighed value is within an allowable range. are doing. In addition, the control unit 13 calculates various control values according to the determination result of whether the weighed value of the workpiece W is within the allowable range and the weighed value, and selectively generates a sorting command signal Rj to perform air jet sorting. It is designed to be output to the machine 20 side. In other respects, it has substantially the same configuration as the above-described one embodiment, so the reference numerals of the corresponding components of one embodiment will be used for the same or similar configurations, and hereinafter mainly one embodiment will be described. The differences from the form will be explained.

In this embodiment, the mass of the workpiece W on the conveyor transport path 11a is measured by the load sensor of the inspection unit 12 via the above-mentioned weighing conveyor, and the measured value is output as the inspection result.

As illustrated in FIG. 7, the product pitch equivalent times A1, A2, A3, and A4 are time intervals based on the product detection time t11 by the article detection sensor on the upstream side of the inspection machine 10, and Aw10 is the product mass Aw20 indicates the allowable product pitch limit for 100g, Aw20 indicates the allowable product pitch limit for product mass 200g, and Aw15 indicates the allowable product pitch limit for product mass 150g. .

The product mass values W10, W20, and W15 are, for example, 100 g, 200 g, and 150 g, respectively, and the corresponding sorting operation times Ton are Ta10, Ta20, and Ta15, respectively, and the corresponding air tank filling time (the solenoid valve response time & Tank filling time) Toff is set to Tb10, Tb20, and Tb15, respectively.

In this embodiment as well, the control unit 30 controls the time interval from when the solenoid valve 23 is closed to when the solenoid valve 23 is opened for eliminating the next work W to be excluded, for example, the product pitch shown in FIG. The corresponding times A1, A2, and A3 are the required time intervals including the predetermined times Aw10, Aw20, and Aw15 necessary for reliable sorting operation (for example, sorting delay time Td+predetermined time Aw10, Aw20, or Aw15 in FIG. 7). It has the function of a monitoring means for monitoring whether the target work W has been reached, and the function of a transport restriction means for restricting the transport of the exclusion target workpiece W by the transport unit 11 based on the monitoring result of the monitoring means.

Here, the product pitch equivalent times A1, A2, and A3 are calculated for each target workpiece W starting from article detection times t11, t21, and t31 when the corresponding workpiece W is carried onto the conveyor transport path 11a of the inspection machine 10, respectively. , the sorting delay time Td specific to this system starts from the article detection time t11, t21, t31, and the sorting operation starts from the sorting operation start time t12, t22, or t32 after the sorting delay time Td has elapsed. The time is longer than the above-mentioned required time interval, which corresponds to the sum of the predetermined time Aw10, Aw20, or Aw15 required for the above. Therefore, when the actual operation permissible time obtained by subtracting the sorting delay time Td from the required time interval is longer than the corresponding predetermined time Aw10, Aw20, and Aw15, normal sorting and discharging operation is possible.

Further, the predetermined times Aw10, Aw20, and Aw15 required for the sorting operation are the sorting operation time Ton when the sorting operation is started from the reference timing, and the sorting operation time t12, t22, and t32 are used as reference timings. It includes the tank filling time Toff which is essential for the supply pneumatic power charge of the air source immediately after the time Ton.

The sorting operation time Ton is set to ensure an effective choke flow period of the solenoid valve 23, and ensure an air blow time that allows the workpieces W of mass W10, W20, or W15 to be excluded to be sorted and discharged from the conveyor transport path 21a. This is a settable period, and is calculated based on a data table and calculation formula for air blow time calculation stored in the memory 31 in advance.

The tank filling time Toff is supplied from the air source by closing the solenoid valve 23 for each sorting and discharging (article removal) operation in which the solenoid valve 23 is opened for the sorting operation time Ta10, Ta20, or Ta15. In this embodiment, the tank filling time Tb10, Tb20, or Tb15 is defined as the response time of the solenoid valve 23 and the tank filling time required for accumulating a predetermined level of pressure in the air tank 28. It is calculated based on data tables and calculation formulas corresponding to the characteristics.

In this embodiment as well, the flow meter 26 and the pressure gauge 27 monitor whether the supplied air pressure power has reached the required level, and during the necessary sorting operation, the air flow rate of the solenoid valve 23 reaches the upstream pressure P1 (primary side pressure). Under the dependent choke flow conditions, sufficient pressure and flow rate of the compressed air flowing from the solenoid valve 23 to the air nozzle 22 is ensured. Therefore, when ejecting compressed air from the air nozzle 22 to remove the workpiece W to be excluded from the conveyor conveyance path 21a, which is the article conveyance line, the workpiece W to be excluded can be accurately removed with pneumatic power corresponding to the required ejection force. A sorting and discharging operation that can be eliminated becomes possible.

Therefore, in this embodiment, it is possible to generate an air blow with a wind pressure load that is sufficiently large relative to the required value of ejection force required for article removal.

That is, in this embodiment, as in the above-described embodiment, not only the air blow time Ton but also the air tank filling time corresponding to the air blow time Ton is added to the predetermined time Aw necessary for the sorting operation of each work W to be excluded. By setting Toff to be included, for each article removal operation for sorting and discharging, the period of article removal operation by air blow from the air nozzle 22 during the sorting operation time Ton is limited to the choke flow period of the solenoid valve 23. At the same time, a decrease in the supplied pneumatic power is effectively suppressed.

Furthermore, the operating conditions for controlling the opening/closing timing of the solenoid valve 23 according to the mass of the workpiece W to be removed can be quickly and accurately set using the table or calculation formula stored in the memory 31 of the control unit 30. Even though the duration of the article ejecting operation is limited to the relatively short choke flow time Tch, accurate timing setting makes it possible to reliably eject the articles.

In addition, the control unit 30 determines the time interval (A4-Td) obtained by subtracting the system-specific sorting delay time Td from the product pitch equivalent time A4, as indicated by "conveyor stop" on the sorting operation time axis in FIG. When the predetermined time Aw15 has not been reached (A4 is less than Aw15) and the valve closing period from the time t43 when the solenoid valve 23 is closed to the time when the valve is opened for removing the next article cannot be secured to be longer than the tank filling time. , the transportation of the work W to be excluded by the transportation units 11 and 21 is stopped.

In this embodiment as well, it is possible to provide an article inspection system 1 having an air jet sorter 20 that can perform a reliable removal operation without increasing costs even if the supply flow rate Qs of compressed air from an air source fluctuates. Can be done.

As described above, the article removal device and article inspection system of the present invention are capable of performing reliable removal operations without increasing costs even if the supply flow rate of compressed air from the air source fluctuates. It is possible to provide an article inspection system. The present invention is useful in general for air blow type article removal devices and article inspection systems that use the wind pressure load of a jet of compressed air.

1 Article inspection system 10 Inspection machine 11 Conveyance section 11a, 21a Conveyor conveyance path (predetermined conveyance path)
12 Inspection section 13 Control section 13a Conveyance control means 13b Inspection control means 13c Arithmetic control means 13d Sorting control means 13e Operation/display means 20 Air jet sorter 21 Conveyance section (sorting conveyance section)
22 Air nozzle 23 Solenoid valve 24 Filter regulator (pressure regulator)
25 Air piping 26 Flow meter 27 Pressure gauge 28 Air tank (energy storage means)
30 Control unit (air blow control means, monitoring means, conveyance restriction means, timing adjustment means)
31 Memory (condition storage means)
32 Article detection sensor A1, A2, A3 Product pitch equivalent time A1', A2', A3' Actual operation allowable time Aw, Aw10, Aw15, Aw20 Predetermined time P1 Upstream pressure (solenoid valve upstream pressure)
P2 Downstream pressure (solenoid valve downstream pressure)
Ps Supply pressure (supply pressure from air source side)
qs1, qs2, qs3, qs4, qs5, qs6 Flow rate Rj Sorting command signal (exclusion signal)
t11, t21, t31 Product detection time (article detection time)
t12, t22, t32 Starting point of sorting operation t13, t23, t33, t43 Point of valve closing Ta10, Ta15, Ta20 Sorting operation time Tb10, Tb15, Tb20 Tank filling time (solenoid valve response time and tank filling time)
Td Sorting delay time Toff, T1off, T2off, T3off Tank filling time (solenoid valve response time and tank filling time)
Ton, T1on, T2on, T3on Sorting operation time (article removal operation time, air blow time)
W10, W15, W20 Mass (product mass value)

Claims (6)

An article removal device that is incorporated in an article conveyance line, supplies compressed air supplied from an air source to an air nozzle through a solenoid valve, and removes the article being conveyed from the article conveyance line by an air blow injected from the air nozzle. And,
Opening and closing the solenoid valve in response to an exclusion signal input to an article to be excluded;
An article removal device comprising an air blow control means for injecting the air blow to the article to be excluded during a choke flow period in which the compressed air passing through the electromagnetic valve is made sonic by opening and closing the solenoid valve. a transport unit that transports the article along a predetermined transport route;
an inspection section that inspects the quality of the article being transported according to predetermined inspection conditions;
a sorting section that excludes articles to be excluded that correspond to a predetermined inspection result of the inspection section from among the articles in a direction away from the predetermined conveyance path by air blowing from an air nozzle arranged along the conveyance section; An article inspection system,
The sorting section is
a solenoid valve provided between an air source that supplies compressed air and the air nozzle;
a control unit that controls opening and closing of the solenoid valve to inject the air blow based on an exclusion signal according to the test result,
The control unit includes:
For the above-mentioned excluded items,
An article inspection system characterized in that the air blow is injected onto the article to be excluded during a choke flow period in which the compressed air passing through the solenoid valve is made sonic by opening and closing the solenoid valve. monitoring means for monitoring whether a time interval from closing the solenoid valve to opening the solenoid valve for removing the next exclusion target article has reached a predetermined time;
3. The article inspection system according to claim 2, further comprising a conveyance restricting means for restricting conveyance of the exclusion target article by the conveying unit based on the monitoring result of the monitoring means. 3. The control unit further comprises condition storage means for storing operating conditions for controlling the timing of opening and closing the electromagnetic valve in accordance with the mass of the object to be excluded. Article inspection system described in . The present invention is characterized in that an energy storage means is provided between the air source and the electromagnetic valve, and on the upstream side of the electromagnetic valve, for storing elastic energy in the compressed air immediately after the end of the choke flow period. The article inspection system according to any one of claims 2 to 4. comprising a detection sensor that detects the article conveyed by the conveyance section upstream of the sorting section;
The control unit includes:
The article inspection system according to any one of claims 2 to 5, further comprising timing adjustment means for correcting the timing of opening and closing the solenoid valve based on the detection signal of the detection sensor.

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