JP3429377B2 - Weighing conveyor - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to improvement of a weighing conveyor used in a production line for various products.

[0002]

2. Description of the Related Art In an automatic production line for merchandise in which goods are weighed to a certain weight and packaged, in the final step, it is checked whether or not the packaged goods have the above-mentioned certain weight. Sometimes a weighing conveyor is used.

This measuring conveyor is, for example, an actual flat plate 5-6.
As disclosed in Japanese Patent No. 6528 and Japanese Utility Model Laid-Open No. 6-25731, a conveyor unit including a motor that drives a roller while winding a belt between a pair of rollers is placed on a load cell, While the article is conveyed by the conveyor unit or the conveyance is temporarily stopped, the weight of the conveyor unit and the goods on the unit is measured by the load cell, and the weight of the known conveyor unit is subtracted from the measured value. Thus, the weight of the article on the unit is measured.

By the way, in this type of weighing conveyor, in order to ensure the required weighing accuracy, it is necessary to mount the conveyor unit on the load cell so that the load is correctly applied to the load cell.

That is, the conveyor unit is relatively bulky, and the rigidity as a whole is not always sufficient, and the conveyor unit is easily bent or deformed due to its own weight or the weight of an article to be conveyed. Therefore, when such a conveyor unit is firmly coupled and placed on the load cell, an eccentric load, a torsional load, or the like acts on the load cell due to the deflection of the unit, which causes a decrease in weighing accuracy. .

In order to deal with this problem, the above-mentioned actual Kaihei 5-
In the weighing conveyor disclosed in Japanese Patent No. 66528, the first load cell is arranged on the side surface on the carry-in side of the gantry, and the second and third load cells are arranged on the side surface on the carry-out side. The load cell of the second load cell is provided with three protrusions corresponding to the load cell, and the load surface of the second load cell is provided with a cylindrical restricting body. The U-shaped restriction bodies corresponding to the above are provided respectively.

According to this, the entire conveyor unit is supported at three points while allowing its deflection and deformation, and the deterioration of the weighing accuracy due to the deflection of the unit is avoided. .

In the weighing conveyor disclosed in Japanese Utility Model Laid-Open No. 6-25731, load cells are arranged at the loading and unloading side ends of the gantry, and bar members extending in the gantry width direction are attached to these load cells. The carrying-in end of the conveyor unit is rotatably supported by the bar member on both sides via a horizontal shaft extending in the pedestal width direction, and the carrying-out side end has anti-vibration rubber on both sides. It is configured to be supported by the bar member via.

Therefore, also by this measuring conveyor, the conveyor unit is supported in a state where the conveyor unit is allowed to bend, especially at the end portion on the unloading side, and the deterioration of the measuring accuracy due to the deflection or the like can be avoided.

[0010]

However, in the case of the former weighing conveyor, the three units provided on the lower surface of the conveyor unit.
Of the two protrusions, one is placed on the load surface of the load cell and its horizontal movement is not restricted, and the other one is engaged with the U-shaped restrictor. The movement in the groove direction is not regulated, and the movement is regulated in any direction only by the protrusion engaged with the cylindrical regulation body.
Therefore, when the gantry is tilted when the weighing conveyor is moved, or when a horizontal load is applied to the conveyor unit on the gantry, depending on the tilt and the direction of the load, the entire conveyor unit is cylindrical. Since it is necessary to support only by the regulation body and the projection engaged with the regulation body, there is concern about the support strength of the conveyor unit in such a case.

Further, in the latter case of the weighing conveyor, in particular, the end of the conveyor unit on the carry-in side is rotatably supported by a bar member fixed to the load cell via a horizontal shaft. When removing the conveyor unit, it is necessary to pull out the horizontal shaft and disassemble the supporting portion, which is troublesome.

Therefore, according to the present invention, as a weighing conveyor of this kind, while the support of the conveyor unit to the pedestal or the load cell is strong, its bending and deformation can be effectively absorbed and high weighing accuracy can be secured. Is
Moreover, it is an object to provide a weighing conveyor in which the conveyor unit can be easily attached to and detached from the gantry.

[0013]

In order to solve the above problems, the weighing conveyor according to the present invention is characterized in that it is constructed as follows.

First, the invention according to claim 1 of the present application (hereinafter,
The first invention) includes a gantry, a pair of load cells respectively arranged on the pedestal upper surface near both ends in the longitudinal direction, and a conveyor unit placed on each of the load cells via a conveyor receiving member. Then, in the weighing conveyor for weighing the weight of the articles on the conveyor unit by the pair of load cells, the conveyor receiving member,
The central portion is fixed to the movable rigid portion of the load cell and extends on both sides in the width direction of the gantry, and notches that are concave when viewed in the gantry width direction are provided at the upper ends of both ends of the gantry. It is characterized in that a total of four elastic members which are engaged with the respective notches from above are provided on the inner surface sides of the lower portions of the side frames on both sides of the unit, which are close to both ends in the longitudinal direction.

Further, the invention according to claim 2 (hereinafter referred to as the second invention) has the side frames on both sides constituting the conveyor unit in the first invention, and both frames at both longitudinal ends of the lower part of these frames. The elastic members according to the first aspect of the present invention are connected to each other by connecting shafts provided therebetween, and each of the connecting members is formed of a tubular body fitted to both ends of the connecting frame so as to be located on the inner surface side of the side frame. It is characterized by having done.

Further, the invention according to claim 3 (hereinafter, referred to as the third
In the first invention or the second invention, the elastic member provided on the inner surface side of the side frame of the conveyor unit has a notch provided at both ends of the conveyor receiving member. It is characterized in that it is dimensioned to engage with a gap in the direction.

On the other hand, the invention according to claim 4 (hereinafter referred to as the fourth invention) includes a pair of load cells according to the first to third inventions, wherein the longitudinal direction of the pair of load cells coincides with the longitudinal direction of the gantry and the longitudinal direction of the gantry. It is characterized in that the fixed rigid body portion is arranged near the center and the movable rigid body portions are arranged near both ends in the longitudinal direction of the gantry.

The invention according to claim 5 (hereinafter referred to as the fifth
The invention) refers to fixing the lower surface of the fixed rigid body portion in the pair of load cells to the upper plate of the pedestal via a spacer that creates a required gap below the movable rigid body portion, and to the upper surface of the movable rigid body portion. It is characterized in that the central portion of the conveyor receiving member is directly fixed.

[0019]

According to the above construction, according to any of the first to fifth aspects, the weight of the conveyor unit and the weight of the articles on the unit are distributed and loaded on the pair of load cells through the conveyor receiving members. become.

In this case, the conveyor receiving member has a structure in which the central portion is fixed to the movable rigid body portion of the load cell and extends to both sides in the pedestal width direction, and notches are provided in the upper portions of both end portions thereof. Elastic members provided on both side frames of the conveyor unit are engaged with the notches from above, so that the conveyor unit is placed on the pair of load cells. Therefore, the conveyor unit can be attached to and detached from the pair of load cells or the conveyor receiving member without requiring special assembling work or disassembling work. The four corners are supported by the four elastic members.

Since the notch is concave when viewed in the pedestal width direction, the position of the conveyor unit in the longitudinal direction relative to the pedestal or load cell is stabilized by engaging the notch with the elastic member. . Further, since the elastic member is provided on the inner surface sides of the side frames on both sides of the conveyor unit, both ends of the conveyor receiving member provided with the notches for engaging with the elastic member and the side frame are arranged in the gantry width direction. Since they are adjacent to each other, the widthwise position of the conveyor unit with respect to the gantry is also stabilized.

In particular, since the engagement between the conveyor unit and the conveyor receiving member is performed via the elastic member as described above, the bending and deformation of the conveyor unit is absorbed by the elastic member, and the load cell is accommodated. The effects of unbalanced load and torsional load are blocked.

Further, according to the second aspect of the invention, since the side frames on both sides of the conveyor unit are connected by the connecting shafts provided between the frames at both ends in the longitudinal direction, the rigidity of the conveyor unit as a whole is increased. Becomes higher. Then, cylindrical elastic members are fitted to both ends of these connecting shafts so as to be located on the inner surface side of the side frame, and are engaged with the notches in the conveyor receiving member, so that a pair of load cells The effects of an unbalanced load and a torsional load on the are more effectively avoided.

Further, according to the third aspect of the invention, the size of the cutouts at both ends of one of the conveyor receiving members is
Since the elastic member on the conveyor unit side is dimensioned to be engaged with a gap in the longitudinal direction of the gantry, while ensuring the stability of the position in the longitudinal direction of the conveyor unit, The dimensional changes will be absorbed by this gap, avoiding any effect on the load cell.

Further, according to the fourth invention, since the pair of load cells are arranged so that the longitudinal direction thereof coincides with the longitudinal direction of the gantry, the conveyor unit is supported symmetrically in the width direction. As a result, it is possible to prevent the measurement accuracy from deteriorating due to the asymmetry.

Further, these load cells are arranged so that the fixed rigid body portion is located near the longitudinal center of the gantry and the movable rigid body portions are located near both longitudinal ends of the gantry, so that the load cell is compact as a whole. However, the distance between the support positions of the load cells with respect to the conveyor unit in the longitudinal direction becomes wide, and the support of the conveyor unit becomes stable.

According to the fifth aspect of the invention, the lower surface of the fixed rigid body portion of the pair of load cells is fixed to the upper plate of the pedestal through the spacer, and the upper surface of the movable rigid body portion has the center of the conveyor receiving member. Since the parts are directly fixed to each other, members such as brackets that are usually used for these fixed parts are not necessary, and the number of parts is reduced.

[0028]

EXAMPLES Examples of the present invention will be described below.

As shown in FIG. 1, a weighing conveyor 1 according to this embodiment has a pair of load cells 20, 2 on a pedestal 10.
0 is arranged, and a conveyor unit 40 is placed on these load cells 20, 20 via conveyor receiving members 30, 30.

The pedestal 10 is provided with legs 12 ... 12 at four corners of a lower surface of a main body 11 formed in a box shape by a frame member, and upper plates 13 and 13 are provided at both longitudinal end portions of the upper surface of the main body 11. The structure is arranged.

The pair of load cells 20 and 20 have the same structure, and the flexure element as the main body thereof has a fixed rigid body portion 21 and a movable rigid body portion 22 at both ends and the upper and lower beam portions 2.
3 and 24 are formed in a hollow quadrangular shape, and flexible portions 25 ... 25 having a thin wall pressure are provided at the connecting portions of the upper and lower beam portions 23 and 24 with both the rigid body portions 21 and 22. Strain sensors (not shown) such as strain gauges are provided on the flexible portions 25 ... 25.

When a load is applied to the movable rigid body portion 22 with the fixed rigid body portion 21 fixed, the movable rigid body portion 22 is
Is relatively downwardly displaced with respect to the fixed rigid body portion 21, whereby compressive strain or tensile strain is generated on the surface of each of the flexible portions 25 ... 25, and this is detected by each of the strain sensors. The load applied to the movable rigid body portion 22 is measured.

Here, these load cells 20, 20
Has its longitudinal direction aligned with the longitudinal direction of the gantry 10,
It is arranged on the center line along the longitudinal direction of the gantry 10 (see FIG. 2), and the fixed rigid bodies 21 and 21 are attached to the gantry 10.
The movable rigid body portions 22, 2 are located at the center side in the longitudinal direction of the
A spacer 14 for ensuring a required space below 2,
Bolts 15 placed on the gantry top plates 13, 13 via 14 and tightened from the lower surface side of the top plates 13, 13.
It is fixed by 15.

The movable rigid members 22, 22 of the load cells 20, 20 have the conveyor receiving member 30,
30 is attached.

These conveyor receiving members 30, 30 are
As shown in FIGS. 3 to 5 in an enlarged manner, the frame member 31 is composed of an upper opening groove-shaped frame member 31 and a pair of receiving plates 32 and 32 fixed to both ends thereof. It is arranged so as to extend in the width direction of the gantry 10, and the central portion thereof is attached to the upper surface of the movable rigid body portion 22 of the load cell 20 by the bolt 3
3 ... 33. In addition, the receiving plate 3
2, 32 are bolts 34 ... 3 with both ends of the frame member 31 fitted in the frame member 31 at the bottom.
Notches 32a that are fixed to each other by 4 and extend upward from the inside of the frame member 31 and have a concave shape when viewed in the width direction of the gantry 10 are provided on the upper side portions thereof.

On the other hand, as shown in FIGS. 1 and 2, the conveyor unit 40 includes a pair of left and right side frames 41, 41 extending in the longitudinal direction of the gantry 10 and these side frames at both ends in the longitudinal direction of the gantry 10. Drive roller 42 and driven roller 43 rotatably supported between 41 and 41, a belt 44 wound around these rollers 42 and 43, and a belt disposed between the side frames 41 and 41. Top plate 45 that supports the upper surface running part of 44
And guide rollers 46, 46, etc. for guiding the lower surface running portion of the belt 44.

A motor 47 is attached to one of the side frames 41 so as to be housed between the upper surface traveling portion and the lower surface traveling portion of the belt 44, and the rotation of the motor 47 drives the motor 47 through the chain 48. The roller 42 is adapted to rotate.

Further, in this conveyor unit 40, as shown in FIGS. 3 to 5, a pair of connecting shafts 50, 50 for connecting the side frames 41, 41 on both sides are provided near the lower ends in the longitudinal direction. In addition, at both ends of the connecting shafts 50, 50, the cylindrical elastic members 51, so as to contact the inner surfaces of the side frames 41, 41, respectively.
51 is fitted.

These elastic members 51 ... 51 are respectively located at the four corners of the lower part of the conveyor unit 40, and their positions are provided on the receiving plates 32 ... 32 of the conveyor receiving members 30, 30. 4 notches 32a in total
The elastic members 51 ... 51 are located at positions corresponding to 32a.
Are engaged with the notches 32a ... 32a, respectively.

As shown in FIG. 5, the dimensions of the notches 32a ... 32a of the receiving plate 32 in the one receiving member 30 are such that the elastic members 51, 5 have a gap x in the longitudinal direction of the gantry.
1 is sized to be engaged.

It should be noted that, as shown in FIG. 1, an electric circuit or a motor 47 for inputting a signal from a strain sensor in the load cells 20, 20 into the center of the upper surface of the gantry 10 and converting it into a load.
A control box 60 in which the control device of FIG.

Further, as shown by a chain line in FIG. 4, below the both ends of the frame member 31 in each conveyor receiving member 30, stoppers 61 for restricting downward displacement and inclination of the receiving member 30 by a constant amount are provided. , 61, and covers 62, 62 for covering both left and right sides of the conveyor unit 40.
Is provided.

Next, the operation of the measuring conveyor 1 will be described.

As shown in FIG. 1, the conveyor receiving member 3 is mounted on the pair of load cells 20, 20 arranged on the frame 10.
When the motor 47 in the unit 40 is operated while the conveyor unit 40 is placed via the 0 and 30, the drive roller 42 is rotated via the chain 48, so that the drive roller 42 and the driven roller 43. The belt 44 wound between and runs, and the article X carried on the belt 44 is conveyed in the A direction, for example.

The weight of the conveyor unit 40 and the weight of the article X are determined by the conveyor receiving members 30 and 30, respectively.
The load is distributed to the pair of load cells 20, 20 via the load cells, the distributed weights are weighed respectively, and the known weight of the conveyor unit 40 is subtracted from the total weight, whereby the article X is Is obtained.

On the other hand, the weighing conveyor 1 has a pair of load cells 20, 2 arranged on the gantry 10 as described above.
The conveyor unit 40 is mounted on the conveyor receiving members 30 and 30 via the conveyor receiving members 30 and 30. Specifically, the receiving plates 32 at both ends of the conveyor receiving members 30 and 30 ...
32 a total of four notches 32 a ... 32 a, side frames 41 on both sides of the conveyor unit 40,
51 are also engaged from above, the conveyor unit 40 is supported on the pair of load cells 20, 20, so that the conveyor unit 40 is A pair of load cells 2
This means that the four corners can be stably supported at a total of four locations of 0 and 20.

In that case, the conveyor unit 40 is
32a is supported by simply engaging the elastic members 51 ... 51 from above with the notches 32a.
Load cells 20, 20 or conveyor receiving members 30,
The attachment / detachment with respect to 30 can be easily performed.

The cutouts 32a ... 32a are concave when viewed in the pedestal width direction.
By engaging the elastic members 51, ..., 51 with the 2a, ..., 32a, the position of the conveyor unit 40 in the longitudinal direction with respect to the gantry 10 or the load cells 20, 20 becomes stable. The dimensions of the notches 32a, 32a at both ends of 30 are such that the elastic members 51, 51 on the conveyor unit 40 side are engaged with each other with a gap x formed in the pedestal longitudinal direction. While maintaining the stability of the position in the longitudinal direction, the change in the dimension in the longitudinal direction due to the deflection of the unit 40 is absorbed by the gap x.

Since the elastic members 51 ... 51 are provided on the inner surfaces of the side frames 41, 41 on both sides of the conveyor unit 40, the notches 32a ... 32a with which the elastic members 51 ... 51 engage are provided. Support plate 32 ...
32 and the side frames 41, 41 are adjacent to each other in the pedestal width direction, whereby the widthwise position of the conveyor unit 40 with respect to the gantry 10 is also stabilized.

In this case, as shown in FIGS. 3 and 4, by setting the dimensional relationship such that the receiving plates 32 ... 32 and the side frames 41, 41 are adjacent to each other with a gap y therebetween, the conveyor unit is constructed. The deformation of 40 in the width direction is also absorbed.

In particular, the engagement between the conveyor unit 40 and the conveyor receiving members 30, 30 is performed via the elastic members 51 ... 51 as described above, so that the conveyor unit 40 may be bent or deformed. Elastic member 51 ... 5
1 is absorbed by itself, and in combination with the action of the gaps x and y, adverse effects due to an unbalanced load and a torsional load on the load cells 20, 20 are effectively eliminated.

In this embodiment, since the pair of load cells 20, 20 are arranged on the center line of the gantry 10 with the longitudinal direction thereof aligned with the longitudinal direction of the gantry 10, the conveyor unit 10 has a width. Since they are supported symmetrically with respect to the direction, deterioration of the weighing accuracy due to the asymmetry of these is prevented.

Further, these load cells 20, 20 are
Fixed rigid body portions 21 and 21 near the center in the longitudinal direction of the gantry 10.
However, the movable rigid body portion 2 is provided near both ends in the longitudinal direction of the gantry 10.
Since the load cells 2 and 22 are arranged so as to be positioned respectively, the load cells 20 and 20 can be compactly arranged on the pedestal 10 and the distance between the support positions relative to the conveyor unit 40 in the longitudinal direction can be widened. The support of the unit 40 will be stable.

Further, the lower surfaces of the fixed rigid body portions 21 and 21 of the load cells 20 and 20 are the spacers 14 and 1, respectively.
It is fixed to the upper plates 13 and 13 of the pedestal 10 via 4 and the central portions of the frame members 31 and 31 forming the conveyor receiving members 30 and 30 are directly fixed to the upper surfaces of the movable rigid bodies 22 and 22. Therefore, a member such as a bracket for fixing them is unnecessary.

[0055]

As described above, according to the weighing conveyor of the present invention, the conveyor unit mounted on the load cell is specially assembled to the load cell or the conveyor receiving member attached to the load cell. It can be easily attached and detached without requiring work or disassembly work, and in the attached state, it can be stably placed on the load cell with the four corners being supported.

In this case, the elastic member provided on the inner surface side of the side frames on both sides of the conveyor unit is engaged with the notch formed in the conveyor receiving member in the cradle width direction as viewed in the width direction. Thereby, the position in the longitudinal direction and the width direction of the conveyor unit with respect to the gantry or the load cell is stabilized, the deflection and deformation of the conveyor unit are absorbed by the elastic member, and the action of the eccentric load or the torsion load on the load cell is prevented. Will be.

In this way, the conveyor unit can be easily attached and detached, the conveyor unit is firmly supported in the attached state, and high weighing accuracy is ensured even when the unit is bent or deformed. A weighing conveyor will be realized.

According to the second aspect of the invention, since the side frames on both sides of the conveyor unit are connected by the connecting shaft, the rigidity of the conveyor unit as a whole is increased, and therefore high weighing accuracy is more effectively ensured. In addition, according to the third aspect of the invention, the stability of the position of the conveyor unit in the longitudinal direction is ensured, and the deterioration of the weighing accuracy due to the change in the dimension in the longitudinal direction due to the deflection of the unit is prevented. Become.

Further, according to the fourth aspect of the invention, since the conveyor unit is supported symmetrically in the width direction, a decrease in weighing accuracy due to the asymmetric support state is prevented, and the overall structure is compact. However, a wide support interval in the longitudinal direction with respect to the conveyor unit is obtained, and the support of the conveyor unit is further stabilized.

According to the fifth aspect of the invention, the load cell, the gantry and the conveyor receiving member are connected with a simple structure, and the number of parts is reduced.

[Brief description of drawings]

FIG. 1 is a front view of a weighing conveyor according to an embodiment of the present invention.

FIG. 2 is a plan view of the weighing conveyor.

FIG. 3 is an enlarged plan view of an essential part taken along the line aa in FIG.

FIG. 4 is an enlarged side view of an essential part taken along line bb in FIG.

FIG. 5 is an enlarged front view of an essential part taken along line cc in FIG.

[Explanation of symbols]

1 weighing conveyor 10 mounts 13 Upper plate 14 Spacer 20 load cell 21 Fixed rigid body 22 Movable rigid body 30 Conveyor receiving member 32a cutout 40 conveyor units 41 side frame 50 connecting shaft 51 Elastic member

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Claims (5)

(57) [Claims] 1. A gantry, a pair of load cells respectively disposed on both sides of a top surface of the gantry in the longitudinal direction, and a conveyor unit mounted on each of the load cells via a conveyor receiving member, A weighing conveyor for weighing the weight of articles on a conveyor unit by the pair of load cells, wherein the conveyor receiving member has a central portion fixed to a movable rigid body portion of the load cell and extending on both sides in the width direction of the gantry, and both ends thereof. It is configured such that a notch forming a concave shape when viewed in the pedestal width direction is provided in the upper part of the section, and on the inner surface side of the lower ends of the side frames on both sides of the conveyor unit near the both longitudinal ends, A weighing conveyor characterized in that each notch is provided with a total of four elastic members which are engaged from above. 2. The side frames on both sides of the conveyor unit are connected by connecting shafts installed at both ends of the lower part of these frames in the longitudinal direction, and the elastic members are connected by the connecting shafts. At both ends, so that it is located on the inner surface side of the side frame,
The weighing conveyor according to claim 1, wherein each of the weighing conveyors is configured by a cylindrical body fitted to each other. 3. The notches provided at both ends of either one of the conveyor receiving members are engaged with an elastic member provided on the inner surface side of the side frame of the conveyor unit with a gap in the longitudinal direction of the gantry. The weighing conveyor according to claim 1, wherein the weighing conveyor is sized. 4. The pair of load cells have a longitudinal direction coinciding with the longitudinal direction of the gantry, a fixed rigid body portion is located near the longitudinal center of the gantry, and a movable rigid body portion is located near both longitudinal ends of the gantry. The weighing conveyor according to any one of claims 1 to 3, wherein the weighing conveyor is arranged as follows. 5. The lower surface of the fixed rigid body portion of the pair of load cells is fixed to the upper plate of the pedestal via a spacer that creates a required gap below the movable rigid body portion, and on the upper surface of the movable rigid body portion, The measuring conveyor according to any one of claims 1 to 4, wherein the central portion of the conveyor receiving member is directly fixed.