JP3016943U - Load detector - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a load detection device that uses a pair of load cell of Roberval structure and can secure weighing accuracy without causing interference between the load cells even on a large platform. [Constitution] A pair of Roberval load cells 3, 3 '
Are attached to the base 1 at appropriate intervals so that the line connecting the centers of the fixed side and the load side is substantially the center line in the longitudinal direction of the mounting table 5, and the rectangular frame 6 is mounted on the lower part of the mounting table. A pair of rotary bearings 7 and 7'are attached to both sides of one end in the longitudinal direction, and their shafts 9 and 9'are fixed to both sides of a connecting metal fitting 4 attached to the load side of one load cell 3, and to both sides of the other end. Attach the pair of rollers 10, 10 'to the fittings 11, 1
A load detecting device configured such that the lower ends of the rollers mounted at 1'contact the upper surfaces of both sides of the connecting fitting 4'mounted on the load side of the other load cell 3 '.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a mounting structure between a load table and a load cell for ensuring weighing accuracy even with a large load table by using two load cells having a Roberval structure.

[0002]

[Prior art]

 Conventionally, there has been a load detection device for a relatively large platform using a strain gauge type load cell of a Roberval structure as shown in FIG. In this figure, one load cell 3 of the Roberval structure has a fixed side attached to the base 1 by a fixture 2 and a load side attached by an H-shaped frame 4 to substantially the center of the mount 5. However, when the platform becomes large, when the object to be weighed is placed on one of the four corners, a torsional stress is generated in the load cell 3, and the magnitude of the torsional stress varies depending on the mounting position, which deteriorates the weighing accuracy. There was a problem. Therefore, Japanese Utility Model Laid-Open No. 6-25731 discloses a structure with a relatively large mount using a pair of load cells. However, in this structure as well, since the vibration-proof rubber 5 between the load-side metal fitting 7 of the load cell and the metal fitting 9B of the mounting table is fixed at their respective connecting portions, there is only escape by loosening the rubber and the orientation of the load cell. Is mounted at a right angle to the longitudinal direction of the conveyor table, an overhang load is applied to a long table, and a weighing error will occur if there is no center of gravity of the object to be weighed between the two load cells. There was a problem that it was easy. Another problem is that it is difficult to adjust the four corners because the center of gravity of the conveyor stand deviates from the load point of the load cell.

[0003]

[Problems to be solved by the device]

 However, the load detecting device having the above-mentioned structure has a problem that a weighing table is relatively large and a weighing error occurs when weighing an object to be subject to an unbalanced load. Therefore, the present invention intends to provide a load detecting device that solves the above-mentioned problems by improving the mounting structure of the load cell and the mounting base while using the load cell of the pair of Roberval structure. It is a thing.

[0004]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, the present invention provides a pair of Roberval structure load cells with fixed sides such that the line connecting the centers of the fixed side and the load side is substantially aligned with the longitudinal center line of the platform. The rectangular frame to the lower part of the platform at the top of the load cell, and a pair of rotary bearings on both ends of the frame in the longitudinal direction. The brackets are fixed to both sides of the fittings attached to the side, and a pair of rollers are attached to the ends of the other end by means of the fittings, and the lower ends of those rollers are attached to the load side of the other load cell. It was configured to contact the upper surfaces of both sides of the metal fitting.

[0005]

[Action]

 Even if the object to be weighed is placed on one of the four corners of the platform of the load detection device of the present invention, the load part rotates around the rotary bearing fixed to the load part of one load cell and its end part is rotated. Since the load will come into contact with the load part of the other load cell and will be loaded, interference will not occur between the two load cells even if the mounting table is distorted.

[0006]

【Example】

 An embodiment of this invention is shown in FIGS. 1A is a plan view, FIG. 1B is a front view, FIG. 2A is a left side view of FIG. 1B, FIG. 2B is a right side view of FIG. 1B, and FIG. 3 is another embodiment in which the mounting direction of the load cell is different. In these figures, 1 is a base of this load detecting device, 2'is a mounting bracket for attaching the fixed side of the load cell to the base 1, 3'is a load cell of a pair of strain gauge type Roberval structures, Numerals 4 and 4'are connecting metal fittings for transmitting a load from the mount 5 mounted on the load side of the load cells 3 and 3 ', and numeral 6 is a frame plate attached to the lower portion of the above-mentioned mount 5. The load cells 3 and 3'are arranged at appropriate intervals such that the line connecting the centers of the fixed side and the load side is substantially aligned with the center line of the mounting table 5 in the longitudinal direction. In FIG. 1B, the fixed sides of the pair of load cells 3, 3'are arranged back to back, but they may be arranged in the same direction as shown in FIG. Further, rotary bearings 7 and 7 ', such as pillow type units, are attached to both sides of one end of the frame plate 6, and brackets 8 and 8'are attached to both sides of the connecting metal fitting 4 below. By inserting the shafts 9 and 9'through the holes of the rotary bearings 7 and 7'and the holes of the brackets 8 and 8 ', the load applied to the mounting table 5 is applied to one of the load cells 3. . On the other hand, the roller mounting brackets 11 and 11 'are attached to both sides of the other end of the frame plate 6, respectively, and the rollers 10 and 10' are attached to the ends thereof by the roller shafts 12 and 12 ', respectively. Since 10 'can freely rotate around the roller shafts 12 and 12' and come into contact with the upper surfaces of both sides of the coupling fitting 4 ', the load applied to the mounting table 5 is the same as the above. The load cell 3'is loaded. Therefore, even if an object to be weighed is placed on one of the four corners of the platform 5, the load part rotates around the shafts 9 and 9'and the opposite side of the shaft is loaded on the load cell in a free state. Even if the table 5 is distorted, there is no fear of causing interference between the load cells. Even if it is extremely loaded on the left end of the mounting table 5, the mounting table 5 is not lifted from the load cell 3'side because the moment on the right side is large.

[0007]

[Effect of device]

 In the load detecting device of the present invention, the load cells of two Roberval structures are arranged in series with an appropriate gap, and one of the load parts of the load cell is a fixed rotating shaft and the other is in contact with a roller. Therefore, it is possible to avoid the interference of the two load cells due to the distortion of the mounting table even on a large mounting table, and it is possible to ensure the weighing accuracy.

[Brief description of drawings]

FIG. 1 is a plan view (A) and a front view (B) of a load detecting device according to an embodiment of the present invention.

FIG. 2 is a left side view (A) and a right side view (B) of FIG. 1B.

FIG. 3 is another embodiment of the present invention in which the mounting direction of the load cell is different.

FIG. 4 is a plan view (A) and a front view (B) of a load detecting device using one load cell of a conventional Roberval structure.

[Explanation of symbols]

 1 Base 2, 2'Fixed-side mounting bracket for load cell 3, 3'Load cell of Roberval structure 4, 4'Load-side coupling bracket for load cell 5 Mounting table 6 Frame plate 7, 7'Rotary bearing 8, 8 'Bracket 9, 9 'Rotary bearing shafts 10, 10' Rollers 11, 11 'Roller mounting brackets 12, 12' Roller shafts

Claims (1)

[Scope of utility model registration request] 1. A load cell having a pair of Roberval structures,
Attach to the base at appropriate intervals so that the line connecting the center of the fixed side and the center of the load side is almost the center line in the longitudinal direction of the mounting table, and attach the rectangular frame plate to the bottom of the above table A pair of rotary bearings are attached to both ends of each of the shafts, and their shafts are fixed to both sides of the coupling fitting attached to the load side of one load cell, and a pair of rollers are attached to both ends of the other end with mounting fittings. The load detecting device, wherein the lower end of the roller is in contact with the upper surfaces of both sides of the connecting fitting attached to the load side of the other load cell.