JP3629089B2 - Weighing device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a weighing device that performs weighing operations such as combination weighing, and more particularly, to a gate opening / closing mechanism of a hopper equipped therein.
[0002]
[Prior art]
As a device used for automatic weighing of various products, there is a combination weighing device. As shown in FIG. 5, many of these apparatuses have a dispersion table (41) disposed through a vibration exciter (42) in the center of a support base (40) disposed on a machine base (not shown). A plurality of supply troughs (43) are arranged radially around the table (41) via another vibrator (44), and the same number of troughs (43) is provided below the tip of each trough (43). The pool hopper (45) and the weighing hopper (46) are arranged in two stages up and down.
[0003]
The weighing procedure in this device is as follows. That is, first, the dispersion table (41) is vibrated by the vibration exciter (42) so that the objects to be weighed on the table (41) are distributed and flown into the supply troughs (43), and the vibration distribution device (44). Then, the object to be weighed is transported to the downstream side of the trough (43) and dropped from the tip of each trough (43), and is stored in each pool hopper (45) on the upper stage. Next, the pool hopper (45) is selectively opened to supply the weighing item therein to the lower weighing hopper (46), and the weight is measured by a load cell (not shown) individually provided in each weighing hopper (46). Weigh. Next, an optimum combination with the total weight equal to or close to the target value is selected from the combination of the measured values in each weighing hopper (46), and the weighing hopper (46) corresponding to the selected combination is selected. Open and discharge the objects to be weighed all at once. This is collected by an inverted conical collecting chute (47) disposed below the weighing hopper (46) and conveyed to the next step such as a packaging step.
[0004]
FIG. 6 is a structural example of the pool hopper (45) and the weighing hopper (46) described above. As shown in FIG. 5A, these hoppers (45) and (46) are usually rotatable by a rectangular tube-shaped main body (50) and gate shafts (51) and (51) provided on the side surfaces thereof. It is composed of pivoted gates (52) and (52). Both gates (52) swing between a closed position (Fig. A) and an open position (Fig. B) about the gate shaft (51), and close and open the lower opening of the main body (50). Conventionally, such an opening / closing movement of the gate (52) is obtained by converting the forward / backward movement of the air cylinder (54) into a swinging movement by a link mechanism (55) made of a plurality of link members. That is, during the opening operation, the piston rod of the air cylinder (54) is advanced, the pressing portion (57) of the drive link (56) is pressed to open the gate (52), and during the closing operation, the air cylinder (54) The piston rod is retracted and its tip is moved away from the pressing portion (57), and the gate (52) is closed using the elastic force of the spring (58) accumulated during the opening operation.
[0005]
[Problems to be solved by the invention]
By the way, in this type of weighing device, the objects to be weighed are often foods, and periodic cleaning operations are indispensable for food hygiene. For this reason, conventionally, a pool hopper and a weighing hopper are attached so as to be hooked on a frame, and these can be easily removed at the time of cleaning so that individual hoppers and the apparatus main body can be cleaned carefully.
[0006]
However, in the conventional apparatus, when removing the hopper, the hopper side mechanism and the apparatus main body side mechanism are separated between the air cylinder (54) and the drive link (56) driven by the air cylinder (54). For this reason, a large number of link members and springs (58) are attached to the removed hopper, which has a drawback in that it is difficult to perform the hopper cleaning operation.
[0007]
Further, when the hopper is removed, the gate (52) is held in a closed state by the elastic force of the spring (58). Therefore, when cleaning the inner surface of the gate (52), the elastic force of the spring (58) is reduced. Therefore, it is necessary to insert a hand into the main body (50) and clean it while pushing the gate (52) apart, which is troublesome. In particular, when the gate (52) is in the fully closed position, the toggle mechanism (59) in the link reaches the dead point and self-locks (see FIG. 6 (a)), which makes the cleaning operation more difficult. That is, the operator releases the lock by pressing the pressing portion (57) toward the hopper while resisting the elastic force of the spring (58), and inserts a hand into the hopper while maintaining this state, thereby moving the inner surface of the gate. An extremely complicated operation of cleaning is required. Therefore, there were many requests for improvement from the user side.
[0008]
Accordingly, an object of the present invention is to provide a weighing device that can reduce the cleaning effort. Specifically, when the hopper is removed from the main body of the apparatus during cleaning, the link mechanism or spring is not attached to the hopper. The purpose is to provide a weighing device that is free and can be moved freely.
[0009]
[Means for Solving the Problems]
To achieve the above object, according to the present invention, in a weighing device equipped with a hopper having a gate that opens and closes a lower opening of a hopper body, any one of a guide pin and a guide groove that engages with the guide pin so as to be relatively movable is provided. One is provided on the gate, and the other is connected to the drive shaft of the rotary drive source so that the one swings in a direction perpendicular to the opening / closing central axis of the gate, and the gate is opened / closed by driving the drive shaft I tried to make it.
[0010]
In this way, if not only the opening operation of the gate but also the closing operation is performed by the driving force of the rotational drive source, the spring that is essential in the conventional apparatus becomes unnecessary. As a result, when the hopper is removed from the apparatus main body at the time of cleaning, the gate is in a free state in which no elastic force acts, so that it is possible to easily clean the gate, the inner surface of the hopper main body, and the like that have been difficult to clean conventionally.
[0011]
The guide pin is driven by a rotational drive source, and the guide groove is provided in the gate so that the relative movement direction of the guide pin in the groove is parallel to the gate opening / closing central axis. At this time, the guide pin may be revolved.
[0012]
The guide groove is driven by a rotational drive source, and a guide pin is provided on the gate so that its axial direction is parallel to the gate opening / closing central axis. At this time, the guide groove may be swung.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of a weighing device according to the present invention will be described with reference to FIGS. 1 to 6 and 8.
[0014]
In the present invention, a rotational drive source (4: see FIG. 3) such as a motor is used instead of a conventional air cylinder as an open / close drive source of the gate (2) which is a component of the hopper (1). Between the rotation drive source (4) and the hopper (1), a guide pin (7) and a guide groove are provided to convert the driving force of the rotation drive source (4) into the closing operation and the opening operation of the gate (2). A conversion mechanism (3) comprising (11) is provided.
[0015]
The rotational drive source (4) is fixed to a stationary member on the apparatus main body side as will be described later, and a drive shaft (5) extending toward the hopper (1) is coupled to the output shaft thereof as shown in FIG. ing. One end portion of a connecting arm (6) extending in a direction perpendicular to the driving shaft (5) is fixed to the driving shaft (5), and a guide is arranged on the other end portion of the connecting arm (6) in parallel with the driving shaft (5). A pin (7) is attached. When the rotational drive source (4) is activated to rotate the drive shaft (5), the guide pin (7) revolves around the drive shaft (5).
[0016]
A guide groove (11) is provided on the back surface of the gate (2) (the surface of the gate on the apparatus main body side, which faces the guide pin (7)). The guide groove (11) is formed between pin-shaped guide portions (12) and (13) spaced apart in the vertical direction along the axial direction of the opening / closing central axis (9: gate axis) of the gate (2). . The guide pin (7) inserted into the guide groove (11) engages with the guide portions (12) and (13) at the top and bottom thereof, and is slidable along the axial direction of the gate shaft (9). Both guide parts (12) (13) are supported by a pair of brackets (14) mounted on the back surface of the gate (2).
[0017]
The width dimension of the guide groove (11) may be a dimension that allows the guide pin (7) to be inserted, and may be not less than the diameter of the guide pin (7). The diameter is the same as that of the diameter so that no gap is formed between them. The length of the guide portions (12) and (13) is set to be equal to or larger than the revolution diameter of the guide pin (7) so that the revolution motion of the guide pin (7) is not hindered by the bracket (14).
[0018]
The guide pin (7) has a sufficient length so that it can always come into contact with both guide portions (12) and (13) during its revolution. Specifically, regardless of the position of the guide pin (7), the length of the tip of the guide pin (7) reaches the hopper (1) side beyond the swinging locus of the guide portions (12) (13). Set to Further, when the guide pin (7) slides in the guide groove (11) in the gate axis direction, the guide pin (7) relatively moves in the direction orthogonal to the slide direction as the gate (2) opens and closes. In order to allow such relative movement, a sufficient space is also ensured between the tip of the guide pin (7) and the back surface of the gate (2).
[0019]
Further, the guide pin (7) has its gate direction (gate) (9) and upper and lower guide portions (12) so that the pressing force generated by the revolving motion is efficiently converted into the opening / closing motion of the gate (2). It is desirable to arrange as close as possible to the line connecting (13).
[0020]
FIG. 4 shows an example of the mounting structure of the hopper (1). As shown in the figure, a pair of mounting members (20) are fixed to the main body (15) of the hopper (1) so as to be separated from each other in the axial direction of the gate shaft (9) (only one mounting member is shown in the drawing). Is shown). On the other hand, on the apparatus main body side, a support base (21) that supports the rotational drive source (4) is attached to a stationary member of the apparatus main body, for example, a support base (23) in a suspended state via a load cell (22). Yes. A pair of locking members (24) spaced apart in the axial direction of the gate shaft (9) are fixed to the support base (21) in the same manner as the mounting members (20). ) Are formed with notched hole-like engaged portions (25), respectively. Protruding engagement portions (26) and (27) are formed on the side surfaces of both attachment members (20) so as to be spaced apart from each other, and the upper engagement portion (26) is a locking member. The lower engaging portion (27) is engaged with the engaged portion (25) of (24), and the lower end surface of the engaging member (24) is engaged to position the hopper (1) in a predetermined position and posture. keeping.
[0021]
With this mounting structure, all the weights of the support base (21), the rotational drive source (4), the hopper (1), the mounting member (20), and the locking member (24) are loaded on the load cell (22). Therefore, the weight of the object to be weighed can be detected from the difference between the weight and the total weight after the object to be weighed is measured.
[0022]
In the above configuration, when the rotational drive source (4) is activated and the guide pin (7) is revolved clockwise, for example, first, the guide pin (7) is at the lowest position (shown by a solid line and a broken line in FIG. 3). The upper guide portion (12) receives an upward pressing force from the guide pin (7) while moving from the uppermost position to the highest position (indicated by a two-dot chain line). As a result, the gate (2) in the closed position (shown by a solid line) swings in the opening direction about the gate axis (9). Along with this, the guide pin (7) restrained up and down by the guide portions (12) and (13) slides in the guide groove (11) from its center to the left side when viewed from the apparatus main body side, and then reverses. Slide in the direction to return to the center position. When the guide pin (7) reaches the highest position, the gate (2) is fully opened (indicated by a two-dot chain line).
[0023]
Next, when the rotational drive source is started in the same direction and the guide pin (7) at the highest position is revolved to the lowest position, the lower guide portion (13) applies a downward pressing force from the guide pin (7). The gate (2) is swung in the closing direction. At this time, the guide pin (7) slides to the right from the center of the guide groove (11), and eventually slides in the opposite direction to return to the center position. When the guide pin (7) reaches the lowest position, the gate (2) is completely closed. At this time, since the guide pin (7) is in the lowest lowered position, that is, at the dead point and is self-locked, the rotational drive source (4) is temporarily stopped and no driving force is applied to the guide pin (7). However, the gate (2) cannot be pushed open from the inner surface side. Therefore, the gate (2) does not open freely with the weight of the object to be weighed, and a toggle function can be provided without adding any special mechanism. Of course, even after the gate is closed, the same locking function can be provided even if the rotational driving source (4) is driven in the same direction as that immediately before the gate is fully closed to apply rotational torque.
[0024]
The starting and stopping of the rotation drive source (4) can be controlled by reading the rotation speed and rotation angle of the output shaft with a sensor such as an encoder.
[0025]
If the rotational drive source (4) is controlled so as to reduce the closing speed immediately before the gate (2) is completely closed, noise generated by the collision of the gate (2) with the hopper body (15) can be reduced. Can do.
[0026]
In the above description, the guide pin (7) is revolved clockwise, but the same function can be achieved even if it is revolved counterclockwise. Further, the guide pin (7) may revolve in the opposite direction between the stroke from the lowest position to the highest position and the stroke from the highest position to the lowest position.
[0027]
Thus, according to the configuration of the present invention, the gate (2) can be opened and closed without using a link mechanism and a spring, and a toggle function can be easily provided without adding a special mechanism. Therefore, the removed hopper is not attached with a link mechanism, a spring or the like, and the hopper (1) can be efficiently cleaned without being disturbed by the link mechanism or the like. Moreover, weight reduction of the hopper (1) is also achieved.
[0028]
When removing the hopper (1) during cleaning, the hopper (1) is pulled upward as shown in FIG. 4, and the guide pin (7) is pulled out from between the guide portions (12) and (13). At the same time, the upper engaging portion (26) may be allowed to escape from the engaged portion (25). Therefore, the hopper can be separated by an extremely simple operation. At this time, since the notched hole-shaped engaged portion (25) is formed in parallel with the axial direction of the guide pin (7), the engaging portion (26) is removed simultaneously with the removal of the guide pin (7). Thus, the above separation operation can be easily performed. As shown in FIG. 4, the removed gate (2) is in a free state where no external force is applied, and can be moved freely. Therefore, the inner surface of the gate (2) (inside the hopper) The exposed surface) can be easily and reliably cleaned.
[0029]
FIG. 2 shows another configuration example of the guide groove (11). As shown in the figure, the guide groove (11) can also be formed by forming a long hole in a plate material bent into a substantially U-shaped cross section.
[0030]
In the above description, the guide pin (7) is disposed on the driving side and the guide groove (11) is provided on the gate (2) on the driven side, but conversely, the guide pin (7 ) May be provided on the driven side gate (2), and the guide groove (11) may be provided on the driving side. FIG. 7 shows an example of this, and a swinging member is disposed on the back surface of the gate (2) in parallel with the direction of the gate axis (9), and is swingably driven by a rotational drive source (not shown). The guide groove (11) is provided at the swing end of (30). The swing member (30) converts the rotational motion of the drive shaft of the rotational drive source into the swing motion by the cam mechanism (31), and transmits this by the two link members (32) and (33), whereby the pivot shaft It is driven to swing around (34). When the swing member (30) swings, the guide pin (7) engaged with the guide groove (11) receives a pressing force from the swing member (30), and the gate (2) has a solid line position and a two-dot chain line. Open and close movement between positions.
[0031]
1 to 4 and 7, a single-open hopper having one gate (2) is shown, but the same applies to a double-open hopper having two gates as shown in FIG. The configuration of can be applied. In this case, the opening / closing mechanism shown in FIGS. 1 to 4 may be applied to one gate, and the other gate may be connected to the one gate via the connecting link (60) shown in FIG. In addition, the above opening / closing mechanism may be provided independently for each of the two gates. The gate opening / closing mechanism described above can be applied to both the pool hopper (45) and the weighing hopper (46) of the weighing apparatus shown in FIG.
[0032]
【The invention's effect】
Thus, according to the present invention, the gate can be opened and closed without using a link mechanism and a spring, and a toggle function can be easily provided without adding a special mechanism. Therefore, the link mechanism or the spring is not attached to the removed hopper even at the time of cleaning, and the hopper can be efficiently cleaned without being disturbed by the link mechanism or the like. Moreover, since the removed hopper is in a free state where the external force is not applied and can be moved freely, the inner surface of the gate, which was difficult to clean with the conventional apparatus, can be easily and reliably cleaned. Further, the weight of the hopper can be reduced, and since there are no complicated links or springs, the hopper has a clean appearance, dust and the like are less likely to adhere, and the frequency of cleaning is reduced.
[0033]
Further, since the gate is closed by being driven by a rotational drive source such as a motor, it is possible to mitigate the impact sound generated when the gate collides with the hopper body at the moment of closing. That is, in the conventional product, the closing force of the gate is obtained by the elastic force of the spring. Therefore, the closing speed of the gate cannot be controlled, and the gate violently collides with the hopper body due to inertia, resulting in annoying noise. However, in the present invention, since the gate is closed by the rotational drive source, the rotational drive source can be electrically controlled so that the closing speed decreases immediately before closing, and the noise level can be easily reduced.
[Brief description of the drawings]
FIG. 1 is a perspective view of a gate opening / closing mechanism equipped in a weighing device according to the present invention.
FIG. 2 is a perspective view showing another embodiment of the guide groove.
FIG. 3 is a side view of the gate opening / closing mechanism shown in FIG. 1;
4 is a side view of the gate opening / closing mechanism shown in FIG. 1. FIG.
FIG. 5 is a longitudinal sectional view of a general weighing device.
FIG. 6 is a side view of a conventional gate opening / closing mechanism.
FIG. 7 is a side view showing another embodiment of a conversion mechanism.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Hopper 2 Gate 3 Conversion mechanism 4 Rotation drive source 7 Guide pin 9 Opening / closing center axis (gate axis)
11 Guide groove 15 Hopper body

Claims (3)

In a weighing device equipped with a hopper having a gate that opens and closes the lower opening of the hopper body,
Either one of a guide pin and a guide groove that engages with the guide pin so as to be relatively movable is provided on the gate, and the other is rotated so that the one swings in a direction perpendicular to the opening / closing central axis of the gate. A weighing apparatus, wherein the gate is opened and closed by being connected to a drive shaft of a drive source. The guide pin is driven by a rotational drive source, and the guide groove is provided in the gate so that the relative movement direction of the guide pin in the groove is parallel to the gate opening / closing central axis. 1. The weighing device according to 1. 2. The measuring device according to claim 1, wherein the guide groove is driven by a rotational drive source, and the guide pin is provided on the gate such that its axial direction is parallel to the opening / closing central axis of the gate.

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