JP7455479B2 - combination scale - Google Patents

Description

The present invention relates to a combination scale for weighing objects of a predetermined weight.

As shown in Patent Document 1, for example, there is a semi-automatic combination weigher in which articles are manually fed and articles are automatically discharged. In the combination scale of Patent Document 1, objects to be weighed are manually fed to a plurality of weighing conveyors arranged horizontally in parallel, and a predetermined weight range is determined by a combination calculation based on the weight of the fed objects to be weighed. A combination of multiple weighing conveyors is selected, and the objects to be weighed on the selected weighing conveyor are sent to a collection conveyor that transports them along the row of weighing conveyors, and this collection conveyor transports the objects to be weighed in a predetermined weight range to a packaging machine, etc. The equipment is then transported to the next stage of equipment.

Japanese Patent Application Publication No. 2018-66600

Combination scales that weigh food are regularly cleaned, but during this cleaning, the control box that houses the load sensor and electrical components must have a sealed structure to prevent cleaning water from entering. On the other hand, it is necessary to prevent a difference between the internal pressure of the control box and the outside air pressure so as not to reduce the measurement accuracy of the load sensor inside the control box.

Therefore, in the past, a vent was provided in a place where cleaning water would not come into contact with the control box, such as the bottom of the control box, to prevent cleaning water from entering and to prevent a difference between the internal pressure of the control box and the outside air pressure. I have to.

However, with a waterproof structure that has ventilation holes on the bottom of the control box, etc., it is impossible to satisfy the IP (International Protection) rating specified by the IEC (International Electrotechnical Commission), which is IPX6, which does not have harmful effects even from strong direct jets. However, it cannot satisfy IPX7, which is a higher grade and does not allow water to enter even if submerged under water for a specified pressure and time.

The present invention has been made with attention to these points, and an object of the present invention is to provide a combination scale that does not create a difference between the internal pressure of the control box and the external pressure, and has a high waterproof rating. do.

In order to achieve the above object, the present invention is configured as follows.

(1) The present invention is a combination weigher comprising an apparatus main body including a control box with a closed structure housing a load sensor, and an operation setting display connected to the control box of the apparatus main body,
The apparatus has a ventilation passage communicating with the control box to equalize the pressure inside the control box and the outside air pressure, and the ventilation opening of the ventilation passage is located above the main body of the apparatus.

According to the present invention, the internal pressure of the control box and the external air pressure can be made equal to each other by the air passage communicating with the control box, so that highly accurate measurement is possible without being affected by the pressure difference between the inside and outside.

In addition, even if the main body of the device is submerged in water, the water level will not reach the vents in the air passages located above the main body of the device, and even if the main body of the device, including the control box, is submerged under water at a specified pressure and for a certain amount of time, Water does not infiltrate and satisfies the waterproof rating of IPX7.

(2) In a preferred embodiment of the present invention, the upper end is sealed and the large diameter ventilation pipe is erected at a height exceeding the height of the device main body, and the large diameter ventilation pipe is smaller in diameter than the large diameter ventilation pipe. a small diameter ventilation pipe led out from the control box and inserted into the large diameter ventilation pipe from below, an upper end of the small diameter ventilation pipe communicating with the inside of the upper end of the large diameter ventilation pipe; The inside of the upper end of the ventilation tube communicates with an air passage formed by the inner peripheral surface of the large diameter ventilation pipe and the outer peripheral surface of the small diameter ventilation pipe, and a vent at the lower end of the ventilation passage communicates with the outside air.

According to this embodiment, the upper end of the small diameter ventilation pipe led out from the control box communicates with the inside of the upper end of the large diameter ventilation pipe that is erected at a height exceeding the height of the equipment main body. Even if the control box is submerged in water, the water will not reach the upper end of the small diameter ventilation pipe inside the upper end of the large diameter ventilation pipe, and water will not enter into the control box.

(3) In one embodiment of the present invention, the ventilation port at the lower end of the ventilation path communicates with the inside of a downwardly opened ventilation cover provided on the outer surface of the control box.

According to this embodiment, even if cleaning water falls on the ventilation cover during cleaning, the cleaning water will not penetrate into the interior of the ventilation cover.

In addition, the ventilation cover functions as a mounting base for supporting the base of the large diameter ventilation pipe on the control box, and the structural members can be used for multiple purposes.

(4) In another embodiment of the present invention, the operation setting display device is connected and supported at the upper end of the large diameter ventilation pipe.

According to this embodiment, since the large-diameter ventilation pipe forming the ventilation path connects and supports the operation setting display, it is possible to reduce costs by using the same as a member.

In addition, since the small diameter ventilation pipe is inserted into the large diameter ventilation pipe that connects and supports the operation setting display, it is possible to provide a ventilation structure that exhibits a high waterproof function while maintaining an appearance similar to conventional ones.

(5) In still another embodiment of the present invention, the mounting base of the operation setting display is externally fitted from above to the upper end of the large diameter ventilation pipe whose upper end is open, and is sealed.

According to this embodiment, there is no need for a dedicated lid member for sealing the upper end opening of the large-diameter ventilation pipe and its attachment, and costs can be reduced accordingly.

(6) In one embodiment of the present invention, the device main body includes a plurality of weighing conveyors arranged in parallel, and a collection conveyor that conveys the objects to be weighed carried out from the weighing conveyors along the weighing conveyor row. The load on the weighing conveyor is detected by the load sensor housed in the control box.

According to this embodiment, by making the control box housing the load sensor ventilated with the outside via the ventilation path, it is possible to avoid a difference between the internal pressure of the control box and the outside air pressure, and Highly accurate measurement can be performed based on the detection output of the load sensor without being affected by pressure differences.

(7) In another embodiment of the present invention, the weighing conveyor row and the control boxes for each weighing conveyor row are arranged on both sides of the collecting conveyor, and the control box on one side is arranged on both sides of the collecting conveyor. The control box has the ventilation path that equalizes the pressure inside the control box and the outside air pressure, and the control box on one side and the control box on the other side are connected to each other by a communication pipe.

According to this embodiment, by equipping the control box on one side with a ventilation path that equalizes the internal pressure and the external pressure, ventilation can be performed in both control boxes via the communication pipe, and both control boxes can be Manufacturing costs can be reduced compared to the case where a ventilation path is provided.

As described above, according to the combination weigher according to the present invention, there is no difference between the internal pressure of the control box in which the load sensor is housed and the external atmospheric pressure, so that the weighing accuracy does not deteriorate. Furthermore, even if the main body of the apparatus is submerged in water, water does not enter into the control box, satisfying the waterproof grade IPX7.

FIG. 1 is a perspective view of a combination weigher according to an embodiment of the present invention. FIG. 2 is a plan view of the combination weigher shown in FIG. 1. FIG. 3 is a front view of the combination scale of FIG. 1. FIG. 4 is a side view of the combination weigher of FIG. 1. FIG. 5 is a perspective view of the combination weigher with the protective cover opened. FIG. 6 is a plan view of the combination weigher with the protective cover opened. FIG. 7 is a perspective view of the combination scale with the weighing conveyor removed. FIG. 8 is a longitudinal side view showing the waterproof ventilation structure. FIG. 9 is an exploded perspective view of the main parts of the control box and waterproof ventilation structure.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view of a combination weigher 1 according to an embodiment of the present invention, FIG. 2 is a plan view thereof, FIG. 3 is a front view thereof, and FIG. 4 is a side view thereof.

This combination weigher 1 is a semi-automatic combination weigher in which an operator manually supplies objects to be weighed and automatically carries out the objects to be weighed so that the total weight falls within a predetermined weight range.

This combination scale 1 includes a collection conveyor 2 consisting of a belt conveyor on which objects to be weighed are placed and transported in a fixed direction A, and a collection conveyor 2 that is arranged in parallel along the transport direction A on both sides of the collection conveyor 2. a weighing conveyor 3 consisting of a plurality of belt conveyors (7 on each side, 14 in total), and a touch panel type operation setting display 4 for setting operation control parameters and displaying the operating status of the combination weigher 1. , and a base 5 that supports them.

The collection conveyor 2 transports the objects to be weighed selected by the combination calculation and discharged from the weighing conveyor 3 in the direction of arrow A, and discharges them to, for example, a next-stage packaging machine (not shown). It will be packed in a bag.

The weighing conveyors 3 are linearly arranged in two rows on both sides of the collecting conveyor 2 along the conveying direction of the collecting conveyor 2. The conveying direction of each weighing conveyor 3 is a direction perpendicular to the conveying direction A of the collection conveyor 2, as indicated by arrow B.

At the upper part of the base 5, a plurality of load measuring units 6 are installed in parallel on both sides of the collecting conveyor 2, and a weighing conveyor 3 is mounted and supported on each load measuring unit 6, respectively. The weight of the entire weighing conveyor on which the objects to be weighed are placed is detected by a load sensor such as a load cell built into the load measuring section 6, and the weight of the weighing conveyor 3 is subtracted as a tare weight from the detected weight. The weight of the object to be weighed is measured.

During operation, a worker standing in front of the three rows of weighing conveyors manually supplies the objects to be weighed to the empty weighing conveyor 3 that is stopped, and selects objects to be weighed within a predetermined weight range through combination calculations. The objects to be weighed on the plurality of weighing conveyors 3 are fed into the collection conveyor 2, and the objects to be weighed within a predetermined weight range are discharged from the terminal end of the collection conveyor 2 and fed into the packaging machine.

In the following explanation, in order to facilitate understanding of the structure, the upper side of the conveyor direction A in the collection conveyor 2 will be referred to as the front, the lower side will be referred to as the rear, and the horizontal direction perpendicular to the conveyance direction A will be referred to as the left and right direction. I decided to do it.

A control box 7 with a sealed structure containing a power supply board, an arithmetic control board, etc. is disposed outside and below the three rows of weighing conveyors and is supported by a base 5, and the lower part of the collection conveyor 2 is largely open. . A long protective cover 8 is provided on the top of the control box 7, which covers the top of the control box 7 from above and from the outside to prevent workers from inadvertently approaching the starting end of the weighing conveyor 3 or its drive unit. It is designed to prevent people from coming into contact with them.

FIG. 5 is a perspective view of the combination weigher 1 with the protective cover 8 open, and FIG. 6 is a plan view of the combination weigher 1 with the protective cover 8 opened.

As shown in FIG. 6, the protective cover 8 is rotatably supported on the upper part of the control box 7 via a plurality of hinges 9. As shown in FIGS. 1 to 4, the protective cover 8 is swung upward in a closed position, and as shown in the imaginary line in FIG. 3, and as shown in FIGS. It is possible to switch to an open position in which it is swung outward, which is the direction in which it moves (away from you).

The hinge 9 is a torque hinge that provides appropriate resistance to cover rotation, and can be stably held in the closed and open positions without requiring any special locking operation.

Further, on the upper surface of the protective cover 8, an indicator light 10 is provided corresponding to each weighing conveyor 3, and an emergency stop button 11 for stopping the operation is provided. The indicator light 10 is used, for example, to inform a worker that the object to be weighed supplied onto the weighing conveyor 3 is out of the appropriate weight range, and to prompt the operator to replace the object. The indicator light 10 and the emergency stop button 11 are waterproofed and connected to the control box 7.

During normal operation, the protective cover 8 is held in a closed position, but during cleaning work, the protective cover 8 must be opened and the weighing conveyor 3 must be removed to wash away fragments and slag of the objects to be weighed. .

Although the detailed structure is not shown, each weighing conveyor 3 is detachably attached to and supported by the respective load measuring section 6 via pin engagement means, and as shown in FIG. Then, the weighing conveyor 3 is removed from the load measuring section 6 for cleaning, maintenance, etc. In addition, a conveyor drive gear driven by an internal motor is installed on the outside of the load measuring section 6, and when the weighing conveyor 3 is positioned and loaded into the load measuring section 6, The passive gear automatically interlocks with the conveyor drive gear.

The load measuring section 6 itself is configured to be waterproof and accommodates a load sensor, and is connected to the upper part of the control box 7 in a ventilated manner. is housed within. Furthermore, the internal pressure of the load measuring section 6 and the internal pressure of the control box 7 are maintained at the same level. A dehumidifier is installed in the control box 7 to prevent condensation.

In the combination scale having the above configuration, it is necessary to prevent a difference between the internal pressure of the control box 7 with which the load measuring section 6 communicates and the external pressure so that the measurement accuracy at the load measuring section 6 does not deteriorate.

In addition, since the combination scale of this embodiment weighs food, regular cleaning is required, and the parts such as the weighing conveyor 3 and the load measuring section 6 below, which come into direct contact with food, are Because of the strong adhesion of debris and sludge, a higher waterproof grade is desired. In this embodiment, the device is configured to meet IPX7, which prevents water from entering even if the main body of the device, excluding the operation setting display 4, is submerged in water.More specifically, the device satisfies dustproof and waterproof class IP67. .

Note that the operation setting display 4, which only performs operation and display, does not require a high waterproof grade like the main body of the device other than this operation setting display 4, and has the same waterproof grade as the conventional one. It also satisfies IPX5, which means it is not subject to any harmful effects, and more specifically, it satisfies dustproof and waterproof rating IP65.

The combination weigher of this embodiment is characterized by a waterproof and ventilated structure of the device body other than the operation setting display 4, and the details will be described below with reference to the drawings.

FIG. 8 is a longitudinal side view showing the waterproof ventilation structure, and FIG. 9 is an exploded perspective view of the main parts of the control box and the waterproof ventilation structure.

The two control boxes 7, which are arranged to face each other with a large distance between them with the collection conveyor 2 in between, are communicated with each other through a pair of front and rear communication pipes 20 so as to be able to ventilate each other. The internal pressures of all the load measuring sections 6 are kept the same.

The waterproof ventilation structure is installed in one of the two control boxes 7 (on the left side in the front view of FIG. 3). As shown in FIG. 9, the control box 7 is formed into a box shape with a shallow depth that is completely opened laterally and outwardly, and various electrical components constituting the power supply section, control section, etc. are mounted on support plates. 30 and housed in the control box 7. The horizontal opening of the control box 7 is sealed in a watertight manner by a lid cover 22 which is screwed together via a packing 21.

A stay 23 is provided protruding from the rear side of one of the control boxes 7 having a waterproof ventilation structure, and a downwardly opened ventilation cover 24 is connected thereto with a screw. A packing 25 is interposed at the joint between the ventilation cover 24 and the rear side surface of the control box 7, and only the lower end of the ventilation cover 24 is opened and communicated with the outside.
The lower end of a large-diameter ventilation pipe 26 made of, for example, a stainless steel pipe is inserted into the rear surface of the ventilation cover 24 and is fixed upright by welding the entire circumference.

In addition, a small-diameter ventilation pipe 27 made of, for example, a tube bent into an L shape is inserted into the rear side of the control box 7 in a watertight manner through a waterproof grommet 28, and as shown in FIG. A small diameter ventilation pipe 27 is inserted along the large diameter ventilation pipe 26 to near the upper end of the large diameter ventilation pipe 26. The upper end of the large-diameter ventilation pipe 26 extends to a position higher than the level L of the upper surface of the apparatus main body excluding the operation setting display 4.

The large-diameter ventilation pipe 26 is also used as a mounting support for the operation setting display 4, and a large-diameter ventilation pipe 26 is attached to the mounting boss 4b with an upper base provided on the mounting seat 4a of the operation setting display 4. The upper end of the trachea 26 is inserted from below, and a seal ring 29 is interposed at the rear end of the fitting to seal the upper end opening of the large diameter ventilation pipe 26.

Therefore, the ventilation path s formed inside the small-diameter ventilation pipe 27 extends to a high place near the upper end of the large-diameter ventilation pipe 26, so that the inner peripheral surface of the large-diameter ventilation pipe 26 and the outer peripheral surface of the small-diameter ventilation pipe 27 It is connected to a cylindrical ventilation path s' formed between the A lower end portion of the large diameter ventilation pipe 26 forming the ventilation path s' communicates with the inside of the ventilation cover 24. That is, the ventilation paths s and s' that communicate the control box 7 with the outside air are guided to a lower position by making a large detour to a higher place, and communicate with the outside air within the ventilation cover 24 that is opened downward.

Although not shown, the power supply and communication cable for the operation setting display 4 connected to a predetermined circuit section in the control box 7 is inserted into the ventilation cover 24 from the rear side of the control box 7 through a waterproof grommet. It is inserted and led out, and further extends upward through a ventilation path s' between the large diameter ventilation pipe 26 and the small diameter ventilation pipe 27. This power supply and communication cable is connected to the operation setting display 4 via a waterproof grommet provided at the upper bottom of the mounting boss portion 4b of the mounting seat portion 4a. Further, the control boxes 7 separated from each other on the left and right sides are electrically connected by cables inserted through the communication pipe 20.

The waterproof ventilation structure of the control box 7 is configured as described above, and during normal operation, the control box 7 is connected to the inside of the ventilation cover 24 at a low position via the ventilation paths s and s' that detour through a high place. This allows ventilation between the control box 7 and the outside. Therefore, the internal pressure of the control box 7 and the load measuring section 6 connected thereto is maintained at the same level as the external pressure.

Since the vent opening to the outside of the ventilation path s' is located inside the ventilation cover 24, there is no risk of infiltration into the ventilation path s' even if washing water is poured from above during cleaning. Furthermore, as shown in FIGS. 4 and 8, even if the device main body is submerged in water up to the level L of the top surface, the water surface that enters the large diameter ventilation pipe 26 does not reach the upper end of the small diameter ventilation pipe 27. The control box 7 will not be submerged in water. In addition, the indicator light 10 and emergency stop button 11 provided on the protective cover 8 on the control box 7 are waterproofed and connected to the control box 7, so even if the main body of the device including the control box 7 is submerged in water. , it is possible to meet IPX7, which prevents water from entering the main body of the device including the control box 7.

That is, with level L on the top surface of the device main body excluding the operation setting display 4 as the boundary, the device main body below the level L satisfies the waterproof class IPX7, more specifically, the dustproof and waterproof class IP67. Further, the operation setting display 4 above level L on the top surface of the device main body satisfies the same waterproof class IPX5 as in the past, more specifically, the dustproof and waterproof class IP65.

As described above, according to the present embodiment, the internal pressure of the control box 7 and the external pressure can be made equal to each other by the air passages s and s' communicating with the control box 7. Highly accurate measurement is possible without any problems.

In addition, even if the main body of the device except for the operation setting display 4 is submerged in water, the water level will not reach the vent at the upper end of the ventilation path s′ located above the main body of the device, and the water level will not reach the vent at the upper end of the air passage s′, which is located above the main body of the device. Even if the device is submerged in water, water will not enter the main body of the device including the control box 7. That is, it is possible to satisfy the high waterproof grade IPX7.

[Other embodiments]
The present invention can also be implemented in the following forms.

(1) In the above embodiment, the air passage communicating with the control box was bent downward by making a large detour to a height exceeding the height of the device. , a vent communicating with the outside air may be provided.

For example, the upper end of the small-diameter ventilation pipe 27 may be exposed to the outside air via the operation setting display 4 to serve as a ventilation hole, and this ventilation hole may be covered with a ventilation cover or the like.

(2) It is also possible to implement a specification in which three groups of weighing conveyors are arranged in parallel only on one side of the collecting conveyor 2.

(3) Each of the plurality of control boxes 7 may be provided with a waterproof ventilation structure.

(4) Combination scales are not limited to the above-mentioned semi-automatic combination scales that manually supply and discharge objects to be weighed, but also manual scales that manually supply and discharge objects to be weighed. It is possible to apply the present invention to a combination scale or an automatic combination scale that automatically supplies and discharges objects to be weighed.

1 Combination scale 2 Collection conveyor 3 Weighing conveyor 4 Operation setting display 4a Mounting seat 6 Load measurement section 7 Control box 24 Ventilation cover 26 Large diameter ventilation pipe 27 Small diameter ventilation pipe

Claims (7)

A combination weigher comprising: a device main body including a control box that accommodates a load sensor and has a closed structure other than a portion communicating with a ventilation path ; and an operation setting display connected to the control box of the device main body. ,
a ventilation passage communicating with the control box to equalize the pressure inside the control box and the outside air pressure, the ventilation opening of the ventilation passage being located above the main body of the apparatus;
A combination scale characterized by: a large diameter ventilation pipe whose upper end is sealed and which is erected at a height exceeding the height of the device main body;
a small diameter ventilation pipe having a smaller diameter than the large diameter ventilation pipe, led out from the control box, and inserted into the large diameter ventilation pipe from below;
The upper end of the small diameter ventilation pipe is communicated with the inside of the upper end of the large diameter ventilation pipe, and the inside of the upper end of the large diameter ventilation pipe is formed by the inner peripheral surface of the large diameter ventilation pipe and the outer peripheral surface of the small diameter ventilation pipe. communicated with an air passage, and a vent at a lower end of the air passage communicated with outside air;
The combination weigher according to claim 1. The ventilation port at the lower end of the ventilation path communicates with the inside of a downwardly opened ventilation cover provided on the outer surface of the control box.
The combination weigher according to claim 2. The operation setting display device is connected and supported at the upper end of the large diameter ventilation pipe.
The combination weigher according to claim 2 or 3. A mounting pedestal for the operation setting display is externally fitted from above to the upper end of the large diameter ventilation pipe whose upper end is open, and the upper end of the large diameter ventilation pipe is sealed.
The combination weigher according to claim 4. The device main body includes a plurality of weighing conveyors arranged in parallel, and a collection conveyor that conveys the objects to be weighed carried out from the weighing conveyors along a weighing conveyor row,
detecting the load of the weighing conveyor by the load sensor housed in the control box;
A combination weigher according to any one of claims 1 to 5. The weighing conveyor row and a control box for each weighing conveyor row are arranged on both sides of the collecting conveyor,
The control box on one side has the ventilation path that equalizes the pressure inside the control box on the one side and the outside air pressure, and the control box on the one side and the control box on the other side are connected to each other by a communication pipe. has been,
The combination weigher according to claim 6.

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