JPS6326739Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a transmission mechanism for transmitting a load applied to a weighing platform to a load cell in a load cell scale.

A disadvantage of load cell scales that use a load cell with a resistance wire strain gauge attached to a strain-generating body is that it is weak against horizontal swinging loads in the front, rear, left and right directions. However, in scales in which a vehicle or conveyed object is driven onto the weighing platform, such as a vehicle weighing machine or a platform scale with a roller conveyor, a horizontal load is applied when the weighing machine is loaded onto the weighing platform. In addition, there are many scales other than these that are subject to horizontal loads.

When a horizontal load as described above is applied to the load cell, an unnecessary load is applied to the load cell, causing deformation such as twisting of the load cell, which not only reduces accuracy but also poses a risk of damage.

For this reason, as described in Japanese Utility Model Publication No. 37-32181, a suspension ring has been connected to the upper pin connected to the load cell and the lower pin connected to the weighing platform to connect both pins, and each pin and the suspension ring have been connected to each other. The transmission mechanism is configured such that the connecting surface is arcuate, and the horizontal load is absorbed by the swinging of the suspension ring via the arcuate connecting surface.

However, in this transmission mechanism, the upper and lower pins are directly fixed to the load cell and weighing platform.
Since the above-mentioned horizontal load is absorbed only by the swinging of the hanging ring, the absorption effect is not smooth and sufficient, and a large horizontal load is sometimes applied to the load cell.

In addition, load cell scales are also vulnerable to overload. In other words, while a safety factor of 5 to 6 times or more was normally set for conventional mechanical scales, in the case of load cells, the strain of the strain generating body must be increased, and the change in resistance output must be increased.
Generally, the safe overload is about 150%, and it is vulnerable to overload. In particular, when the object to be weighed is hung by a crane or the like and placed on the weighing platform, the impact load can be two to three times the actual weight. In addition, depending on the hanging method, most of the load of the object to be weighed may be concentrated at one point when it is placed on the weighing platform. In such a case, an extremely large overload may act on one of the multiple load cells, causing it to break.

In conventional mechanical scales, the lever undergoes elastic deformation in response to impact loads, and the distortion alleviates the impact, but load cell scales often receive the load directly, and there are no parts that can cause mechanical distortion, so it is difficult to use a load cell. The applied shock becomes abnormally large. That is, impact energy is absorbed by the distortion of the object that receives it, but when there is no distortion, the impact energy becomes infinite and the load cell is damaged.

In view of the above-mentioned drawbacks of conventional load cell scales, this invention was developed in the transmission mechanism of a conventional load cell scale in which the upper and lower pins are connected by a hanging ring with an arcuate connection surface. A circumferential groove with an arcuate cross section is formed on both sides of the load cell, and a circumferential groove with an arcuate cross section is formed on both sides of the suspension ring, and a circumferential groove with an arcuate cross section is formed in the center of the upper pin. The annular hook is locked so that the load applied to the upper pin is transmitted to the load cell, and the legs on both sides of the bracket provided at the bottom of the weighing platform are placed on both ends of the lower pin, and the lower pin and the legs are placed in contact with each other. The contact surface is arcuate so that the load of the weighing platform is received by the lower pin, and the lower pin is made of a material that is easily elastically deformable.

With this configuration, horizontal loads applied to the weighing platform can be handled not only by the arcuate connection surfaces between the upper and lower pins and the suspension ring, but also by the arcuate connection surfaces of the hook and the upper pin, and the legs and the lower pin. Absorption action is also performed on the surface (contact surface). In other words, the upper and lower pins are
The absorbing effect is similar to that of the rollers in a so-called rolling bearing, which can move freely relative to the suspension ring, hook, or leg. Incidentally, in the above-mentioned prior art, since the upper and lower pins are directly fixed to the load cell and the leg, the absorption is performed by the action of a so-called sliding bearing.

Furthermore, when an impact load or overload is applied, the lower pin bends and does not transmit the impact or overload to the load cell.

The details of this invention will be explained below based on the attached drawings.

In the figure, reference numeral 1 denotes a weighing platform, and brackets 2 are fixed to the four corners of the lower part of the weighing platform.

3 is a pit excavated to an appropriate depth from the floor 4,
The weighing table 1 is fitted onto the pit 3 with an appropriate gap left, and the load cell support stands 5 are fixed near the four corners of the bottom of the pit 3.
The 6 ends of the load cell fixed above and the bracket 2
and are connected by a transmission mechanism.

7 is an upper pin with a circular cross section, 8 is a lower pin with a circular cross section, the upper pin 7 has three circumferential grooves 9 with an arcuate cross section, and the lower pin 8 has two circumferential grooves with a circular arc cross section. A circumferential groove 10 is formed.

The upper pin 7 has its central circumferential groove 9 engaged with an annular hanging hook 11 fixed to the end of the load cell 6, and the upper ends of hanging rings 12 are engaged with the circumferential grooves 9 on both sides. This suspension ring 12 has a circular cross section, and the circumferential grooves 10 on both sides of the lower pin 8 engage with its lower end.

In this way, when each of the circumferential grooves 9, 10 has an arc-shaped cross section, the suspension ring 12 has a circular cross section, and the hook 11 is annular, the upper and lower pins 7, 8 are connected to the suspension ring 12 and the hook 11.
1 through their mutual arc-shaped surfaces.

A pair of left and right legs 13 are integrally formed on the bracket 2, and both ends of the lower pin 8 are engaged with a semicircular recess 14 formed at the lower end of each leg 13.
Due to the arcuate cross section of the lower pin 8 and the semicircular shape of the recess 14, the lower pin 8 is brought into contact with the leg 13 on an arcuate surface, and the lower pin 8 is made of a material such as spring steel that is prone to distortion due to elastic deformation. It is manufactured using materials.
Further, the same material may be used for the upper pin 7 as well.

This device has the above structure, and when an object to be weighed is placed on the weighing table 1, the load is transferred to the bracket 2.
is applied from the legs 13 to both ends of the lower pin 8. Therefore, the load of the lower pin 8 is applied to the lower part of the suspension ring 12, and both suspension rings 12 pull down both sides of the upper pin 7, applying a downward load to the end of the load cell 6 via the suspension hook 11. An output signal proportional to is transmitted.

Now, for example, a vehicle is approaching weighbridge 1 from the right side of Figure 3.
When a person climbs onto the platform and applies a horizontal force in the direction of the arrow, that is, in parallel to the axis of the load cell 6, the weighing platform 1 moves in the direction of the arrow. 12, the hanging ring 12 simply tilts as shown in FIG. 3 by rolling on the arcuate connection surface (contact surface) with the leg 13, and almost no horizontal load is applied to the load cell 6.

Furthermore, when a horizontal force in a direction perpendicular to the axis of the load cell 6 is applied to the weighing platform 1 as shown in FIG.
Both suspension rings 12 are inclined laterally as shown in FIG. 4 to prevent horizontal loads from being applied to the load cell 6.

Furthermore, when an abnormally large load such as an impact load is applied to the weighing platform 1, the left and right legs 1 of the bracket 2
The lower end of the lower pin 3 pushes both ends of the lower pin 8 downward, causing the lower pin 8 to curve downward as shown in FIG. Therefore, the impact is relaxed and transmitted to the load cell 6 via the pin 7 and the hook 11. In addition, at this time, if the upper pin 7 is also made of an elastically deformable material, the upper pin 7
Since it also bends to provide a buffering effect, the buffering effect becomes even greater.

In addition, in the event of damage to the lower pin 8, etc., the weighing platform 1
A stopper is provided to prevent the weighbridge from falling below a certain level so as not to damage the load cell 6.

This invention is constructed as described above, and in response to the horizontal load applied to the weighing platform, not only the arcuate connection surface between the upper and lower pins and the hanging ring, but also the hook and upper pin,
Since the arcuate connecting surfaces of the legs and the lower pins also have an absorbing effect, the absorbing effect is carried out smoothly and there is no fear that a horizontal load will be applied to the load cell.

Furthermore, since the lower pin is made of a material that is easily elastically deformed, such as spring steel, even if an impact load or overload is applied, the lower pin only bends and does not transmit the impact or overload to the load cell.

Therefore, according to this invention, the load cell is not twisted or damaged, and highly accurate measurement can be performed for many years.

[Brief explanation of the drawing]

Fig. 1 is a partially longitudinal front view of the transmission mechanism of this invention, Fig. 2 is a partially longitudinal side view, Fig. 3 is a partially longitudinal front view of the same operating state, and Fig. 4 is also a partially longitudinal side view. FIG. 6... Load cell, 7... Upper pin, 8... Lower pin, 9, 10... Circumferential groove, 11... Hanging hook, 12... Hanging ring, 13... Leg.

Claims (1)

[Scope of utility model registration request] An upper pin and a lower pin, each having a circumferential groove with an arcuate cross section on both sides, are connected by a hanging ring with a round cross section that engages with the circumferential groove, so that the load applied to the upper pin is transmitted to the load cell, and a weighing platform is used. In the transmission mechanism of a load cell type scale in which the load is received by the lower pin, a circumferential groove with an arcuate cross section is formed in the center of the upper pin, and a circular hook fixed to the end of the load cell is engaged with this circumferential groove. The load applied to the upper pin is transmitted to the load cell, and the legs on both sides of the bracket provided at the bottom of the weighing platform are placed on both ends of the lower pin, and the abutting surfaces of the lower pin and the legs are circularly shaped. A transmission mechanism for a load cell type scale, characterized in that the lower pin has an arc shape so that the load of the weighbridge is received by the lower pin, and the lower pin is made of a material that is easily elastically deformed.