JP6865988B1 - Weight sensor unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a weight sensor unit which can be attached to an object. SOLUTION: This weight sensor unit 1 is a weight sensor unit including a load cell unit 1A which is connected to an arithmetic control unit which arithmetically processes a detection signal from a load cell 2 by a connection line and is attached to an object. The load cell unit 1A in which the load cell 3 including the strain-causing body 3A is incorporated, and the attachment layer 6 provided on the load cell unit 1A to attach the load cell unit 1A to the object are provided at least. The load cell unit 1A is attached to the object by the attachment layer 6, and the presence or absence or weight of the object is detected by the load cell unit 1A. [Selection diagram] Fig. 1

Description

The present invention relates to a weight sensor unit, and more particularly to a weight sensor unit that can be attached to an object to be measured and detected.

Generally, a weight sensor is known as a load cell in which a strain-causing body that deforms under a load and a strain gauge are combined. This weight sensor is built into various weight scales including, for example, an electronic weight scale.
For example, Patent Document 1 discloses an example of an electronic weight scale using the load cell described above.
In this electronic weight scale 30, a spacer member 32 for securing an upward swinging space of the strain-causing body is welded, adhered, etc. on the back side of the four corners of the mounting plate 31 formed in a rectangular shape as shown in FIG. It is fixed by the fixing means of. Further, as shown in FIG. 12, the load cell 33 is fastened to the spacer member 32 by the screw 34, and the leg portion 36 is further attached to the lower surface of the strain generating body 37 forming the load cell 33 by the screw 35. It is attached and fixed via.

In this case, a metal collar 40 is mounted between the lower surface of the head of the screw 35 that connects the leg portion 36 to the strain generating body 37 and the screw hole 39 provided in the leg portion 36. It is configured so that an excessive load (pressure contact force) is not applied to the concave hole 41 on the leg portion 36 side that is received via the hard ball 38.

As a result, as shown in FIG. 12, the hard ball 38 is accommodated in the concave hole 41 of the leg portion 36, the collar 40 and the screw 35 are inserted into the insertion hole 42 of the strain generating body 37, and the screw 35 is inserted into the leg portion 41. By screwing into the screw hole 39, the leg portion 36 can be attached and fixed to the strain generating body 37, and the hard ball 38 can be held in a form supported by the concave hole 41 on the leg portion 36 side.

Although not shown, the electronic weight scale 30 has a calculation control unit (CPU), which is a calculation means for totaling the load signals detected by the load cell 33, and a calculation control unit exposed on the surface side of the mounting plate 31. It is provided with a display unit which is a display means for digitally displaying the calculation result (measured value) of the (CPU).

As described above, in the electronic weight scale (weight scale) disclosed in Patent Document 1, the load cell, the arithmetic control unit (CPU) which is the arithmetic means for totaling the load signals detected by the load cell, and the arithmetic control unit (CPU). A load cell is attached to the back side of the mounting plate via a spacer member, and a leg portion is attached and fixed to the load cell.
Then, by placing the object to be measured (object) on the mounting plate, the load signal detected by the load cell is calculated and processed, and the measured value is digitally displayed.

Japanese Unexamined Patent Publication No. 2003-149038

By the way, there are various kinds of objects to be measured. For example, some objects are so large that they cannot be placed on the weight scale. In addition, the object may be very heavy and difficult to transport to the weighing scale.
Furthermore, there are various ways to use the results of weight measurement, and it is sufficient if the presence or absence (presence or absence) of an object can be detected, and detailed weight measurement may not be required, or weight display may not be required.

To give a concrete example, if the weight of the liquid in the plastic tank can be measured while the plastic tank is placed in place (without placing it on an existing weighing scale), unnecessary transfer work for measurement is unnecessary. Become.
Further, if a weighing scale can be used to detect the object in the carrying basket and the carrying case, the presence / absence (presence / absence) of the object in the basket and the case can be detected. In this case, the weight scale must be large enough to fit in the basket or case, and it may not be necessary to measure the weight in detail.

Furthermore, if a scale can be used to detect the presence or absence of an object housed in the case, such as a precious metal, or an object placed on a shelf, such as a book, the object in the case or on the shelf. The presence or absence (presence or absence) of an object can be detected.
The weigh scale in this case must be large enough to fit in a basket, case, or placed on a shelf, and may not even require detailed weight measurement.

Further, if a weighing scale can be used to detect whether or not a person has left the bed, the presence or absence of a person on the bed can be detected. Again, detailed weight measurement is not required.
And, in the above-mentioned detection of the presence or absence of various objects, a display means for displaying the weight may not be required.

As described above, although there are various requests from the user for the weighing scale, the conventional weighing scale is completed as one measuring device in which the load cell, the arithmetic control unit (CPU), and the display unit are incorporated as described above. There is a technical problem that the above-mentioned requirements cannot be satisfied because the device is made of a device.

Therefore, the present inventor solves the above technical problems by separately forming a load cell, an arithmetic control unit (CPU), and a display unit, and forming a weight sensor unit including the load cell so that it can be attached to an object. We found that it could be solved and came up with the present invention.

An object of the present invention is to provide a weight sensor unit that can be attached to an object.

The weight sensor unit made to solve the above-mentioned problems is a load cell unit in which a load cell including a strain-causing body is incorporated, and a sticking layer provided on the load cell unit and for sticking the load cell unit to the object. And a connection line connecting to an arithmetic control unit that arithmetically processes a detection signal from the load cell, the load cell unit is attached to an object by the attachment layer, and the presence or absence or weight of the object is determined. In the weight sensor unit detected by the load cell unit, the load cell unit comes into contact with a load cell built-in base in which a load cell containing a strain-causing body is incorporated and a part of the load cell incorporated in the load cell built-in base, and the object is described. A grounding member made of a resin material, a spherical protrusion formed on the straining body made of a metal material, and a grounding member provided on the grounding member, which flexes the straining body by applying a load of an object to the straining body. It has a metal push plate that presses the spherical protrusion and a through hole through which the grounding member is inserted to project the grounding surface of the grounding member to the outside, and is attached to the load cell built-in base to form the load cell and the load cell. A cover case that covers a part of the grounding member is provided, the attachment layer is provided on the load cell built-in base, and the load cell built-in base is attached to the object by the attachment layer, and the object is attached. When the ground contact member retracts into the through hole due to the load, the strain generating body is flexed via the metal push plate and the spherical protrusion provided on the ground contact member, and the object is more than a predetermined value. In the case of weight, the ground contact surface of the ground contact member retracts into the through hole, and the lower bottom surface of the cover case touches the ground to receive a part of the load and reduce the load acting on the straining cell. It is characterized by doing.

As described above, in the present invention, since the operation control unit that performs arithmetic processing of the detection signal from the load cell is connected by the connection line, the arithmetic control unit (CPU) and the display unit required by the user are selected. It can be connected to a predetermined arithmetic control unit (CPU) and display unit. Then, the existence or weight of the object required by the user can be displayed.
In particular, since the load cell unit in which the load cell containing the strain-causing body is incorporated is formed so that it can be attached to the object, the object is too large to be placed on a weighing scale, and the object is also subject. The weight can be measured even when the object is very heavy and it is difficult to transport it to the weight scale.
Further, since the load cell unit is formed so as to be attached to an object, a housing such as a weight scale is not required.

Here, the load cell unit comes into contact with a load cell built-in base in which a load cell including a strain-causing body is incorporated and a part of the load cell incorporated in the load cell built-in base, and the load of the object is applied to the strain-causing body. It has a grounding member that bends the strain-causing body by giving it, and a through hole through which the grounding member is inserted to project the grounding surface to the outside, and by being attached to the load cell built-in base, the load cell and the grounding member A cover case that covers a part of the load cell is provided, and the attachment layer is provided on the load cell built-in base, and the load cell built-in base is attached to the object.

In this way, the load cell unit is attached to the load cell built-in base, the grounding member that applies the load of the object to the strain generating body of the load cell, and the load cell built-in base, and covers a part of the load cell and the grounding member. It is unitized with and.
Then, the unitized weight sensor unit is configured so that it can be attached to the object by the above-mentioned attachment layer.
The load cell unit of this weight sensor is easy to assemble, and mechanical parts such as the load cell including the strain-causing body are covered by a cover case provided in each load cell unit to provide a well-formed weight sensor unit. be able to.

Further, when the object has a weight equal to or greater than a predetermined weight, the ground contact surface of the ground contact member retracts into the through hole, so that the cover case receives a part of the load.
In this way, since the grounding member is arranged in a state of being inserted into the through hole formed in the cover case, when a load exceeding a predetermined value is applied from the object, the lower bottom surface of the cover case is grounded and described above. It acts to receive a part of the load, and it is possible to solve the problem that the strain-causing body of the load cell is permanently deformed by receiving an excessive load.
Further, it includes a spherical protrusion formed on the load cell side and a metal push plate provided on the grounding member to press the spherical protrusion.

Here, the strain-causing body includes an outer frame and a tongue-shaped portion connected to the outer frame via a slit, the outer frame is held by the load cell built-in base, and a grounding member is attached to the tongue-shaped portion. It is desirable that a part of the strain is brought into contact with the strained body to add bending.

Further, in a state where the cover case is attached to the load cell built-in base, an insertion portion of a connection line communicating with each of the load cell built-in base and the cover case is formed, and the connection line is connected to the load cell through each of the communication insertion portions. It is desirable that the connecting line be derived from the cover case.

It is desirable that the object includes a mounting plate on which the object is mounted, and the load cell unit is attached to the mounting plate by the sticking layer.
As described above, the load cell unit may be attached not only to the case where the load cell unit is directly attached to the object by the attachment layer, but also to be attached to the mounting plate to detect or measure the object.
Further, it is desirable that the load cell built-in base is provided with a cover case mounting portion that covers the entire back surface of the mounting plate.

According to the present invention, it is possible to obtain a weight sensor unit that can be attached to an object.

It is an exploded perspective view which shows typically the 1st Embodiment of the weight sensor unit which concerns on this invention. It is a top view of the weight sensor unit shown in FIG. Similarly, it is a vertical cross-sectional view of the weight sensor unit. It is a vertical sectional view in the direction orthogonal to FIG. 2B. Similarly, it is a front view of the weight sensor unit as viewed from the cord opening side. It is a vertical sectional view which shows the case cover of a weight sensor unit. It is a vertical sectional view in the direction orthogonal to FIG. 3A. It is a top view which shows the load cell built-in base of a weight sensor unit. It is a vertical sectional view of the load cell embedded base. It is a schematic diagram which showed an example of the use state of the weight sensor unit which concerns on this invention. It is a schematic diagram which showed an example of the use state of the weight sensor unit which concerns on this invention. It is a schematic diagram which showed an example of the use state of the weight sensor unit which concerns on this invention, and is the schematic diagram which shows the form which attached the weight sensor unit to the back surface of the mounting plate. It is sectional drawing for demonstrating the use state which places | place the mounting plate shown in FIG. It is a top view which shows typically the 2nd Embodiment of the weight sensor unit which concerns on this invention. It is a vertical sectional view of the weight sensor unit shown in FIG. 8A. It is a vertical sectional view in the direction orthogonal to FIG. 8B. It is a schematic diagram which shows the mounting plate using the weight sensor unit of FIG. It is a schematic view which shows the back surface of the mounting plate of FIG. It is a perspective view of the bottom side which showed an example of the conventional weight scale (electronic weight scale). Similarly, it is an exploded perspective view of the load cell attachment part of the conventional weight scale.

An embodiment of the weight sensor unit according to the present invention will be described with reference to FIGS. 1 to 4, and an example of using the weight sensor unit will be described with reference to FIGS. 5 to 7.

(Structure of weight sensor unit)
The weight sensor unit 1 shown in FIG. 1 includes a load cell unit 1A, and the load cell unit 1A includes a load cell built-in base 2, a load cell 3, a grounding member 4, and a cover case 5.
In the load cell unit 1A, the cover case 5 is detachably attached to the load cell built-in base 2, so that a part of the load cell 3 and the grounding member 4 is housed in the load cell unit 1A, and the load cell unit 1A becomes a load cell unit 1A. It is unitized.

In the load cell unit 1A, a sticking layer 6 (see FIGS. 2B to 2D) is formed on the back surface (attachment surface to the object) of the load cell built-in base 2.
Further, a connection line 7 for connecting the load cell unit 1A to the calculation control unit (CPU) 11 (see FIGS. 5 to 7), which is a calculation means for totaling the load signals detected by the load cell 3, is provided, and the weight is provided. It is referred to as the sensor unit 1 (see FIG. 2A).
The arithmetic control unit (CPU) 11 is selected according to the purpose of the user. Further, in the state of the weight sensor unit 1 as a single item, it is desirable that the sticking layer 6 can be stored in a state of being covered with an isolation paper (not shown).

The load cell 3 includes a strain generating body 3A formed of a metal material and two strain gauges 3B attached to a part of the strain generating body 3A.
The strain-causing body 3A includes an outer frame 3a and a pair of tongue-shaped portions 3c connected to the outer frame 3a via a slit 3b, and the step portion 2b in which the outer frame 3a is formed on the load cell built-in base 2. In addition to being supported in the above, a part of the grounding member 4 described later abuts on the pair of tongue-shaped portions 3c, and acts to apply bending due to a load to the strain generating body 3A.

That is, by applying the bending to the connecting portion between the outer frame 3a of the strain-causing body 3A and the pair of tongue-shaped portions 3c, one of the two strain gauges 3B is given a traction action, and the other is contracted. Action is given. By detecting the change in the electrical resistance of the two strain gauges 3B due to this, the load applied to the strain generating body 3A is detected.

The grounding member 4 is preferably made of a resin material, and a cylindrical body 4c having a grounding surface 4b is formed on one side with a flange portion 4a in the center, and a pair of tongue-shaped parts 3c of the strain generating body 3A on the other side. A pair of contact portions 4d (see FIGS. 2B and 2C) that are in contact with each other are formed.
Then, the cylindrical body 4c of the grounding member 4 is inserted into the through hole 5a formed in the cover case 5, and the grounding member 4 is formed by the cover case 5 in a state where the grounding surface 4b is projected to the outside of the cover case 5. It is retained (see FIGS. 2B and 2C).
As a result, a part of the load cell 3 and the grounding member 4 described above is covered with the cover case 5.

The cover case 5 covers the four sides of the load cell built-in base 2, and the engaging protrusions 5b of the cover case 5 are locked to the engaging recesses 2d (see FIG. 4B) of the load cell built-in base 2. It can be attached and detached (see FIG. 2B).
As a result, the unitized load cell unit 1A is assembled.

At this time, as shown in FIG. 3A, the load cell pressing rib 5c formed in the cover case 5 comes into contact with the outer frame 3a of the strain-causing body 3A in the load cell 3 housed in the load cell built-in base 2, and the load cell 3 It is fixedly arranged at a predetermined position in the load cell built-in base 2 by the pressing rib 5c (see FIG. 2B).
At the same time, the rectangular notch 5d (see FIG. 3A) formed on the side surface of the cover case 5 communicates with the notch 2c (see FIG. 3B) formed in the load cell built-in base 2. As a result, the insertion portion (cord port) 5e of the connection line 7 to the load cell 3 can be formed (see FIG. 2D).

(Example of installation state (use state) of weight sensor unit)
Next, a usage example of the weight sensor unit 1 will be described.
First, FIG. 5 shows an example of detecting the presence / absence or weight of the liquid in the plastic tank (object) 10.
As shown in FIG. 5, as described above, the weight sensor unit 1 is attached to the load cell unit 1A in which the load cell 3 including the strain generating body 3A is incorporated and the load cell unit 1A to be attached to the object 10. It has a layer 6.

Further, the weight sensor unit 1 includes a connecting line 7. The weight sensor unit 1 is connected by the connection line 7 to a calculation control unit (CPU) 11 which is formed separately from the weight sensor unit 1 and is a calculation means for aggregating load signals detected by a load cell.
Further, the calculation control unit (CPU) 11 is connected to a display unit 12 which is a display means for digitally displaying the calculation result (measured value).

Then, the weight sensor unit 1 (load cell unit 1A) is attached to the bottom surface of the plastic tank 10 by the attachment layer 6, and the presence or absence or weight of the liquid in the plastic tank 10 is detected by the load cell unit 1A.

Here, the arithmetic control unit (CPU) 11 and the display unit 12 required by the user are selected depending on whether the presence or absence of the liquid in the plastic tank 10 is detected or the weight is detected, and the weight sensor unit 1 is designated. It is connected to the arithmetic control unit (CPU) 11 and the display unit 12.
When detecting the presence or absence of the liquid in the plastic tank 10, it is sufficient if it is possible to detect the remaining amount below the predetermined amount or the remaining amount above the predetermined amount, and it is not necessary to measure the remaining amount in detail. Further, the display unit does not need to display a detailed remaining amount, and a display unit capable of displaying the presence or absence of a predetermined remaining amount, for example, an LED may be blinked.

Since the weight sensor unit 1 can be attached to the plastic tank 10 in this way, the liquid in the plastic tank 10 is kept in place (without being transported to the existing weight scale and placed). The weight can be measured, and unnecessary transportation work for measurement becomes unnecessary. Further, since the weight sensor unit 1 and the arithmetic control unit (CPU) 11 are formed separately and connected by a connecting line, a housing unlike a conventional weight scale is not required.

Although not shown, a transmission means may be connected to the arithmetic control unit (CPU) 11 to transmit the detection result of the weight sensor unit 1 to a distant person.

Next, FIG. 6 shows an example of use for detecting the presence or absence of a person on the bed or the position of the person on the bed.
The weight sensor unit 1 (load cell unit 1A) is attached to each of the bottom surfaces of the four feet 13a of the bed 13 by the attachment layer 6, and the load applied to the four feet 13a is applied to the weight sensor unit 1 (load cell unit 1). ) Is detected.
That is, the presence or absence of a person on the bed 13 is detected by the load cell unit 1A. It is also possible to detect the position of a person on the bed 13 by detecting the weights applied to the four feet 13a of the bed 13 and analyzing the loads.
The user selects the required arithmetic control unit (CPU) 11 and display unit 12 depending on whether the presence or absence of a person on the bed 13 is detected or the position of the person on the bed 13 is detected. Connects the weight sensor unit 1 to a predetermined arithmetic control unit (CPU) 11 and display unit 12.

By attaching the weight sensor unit 1 to the foot portion 13a of the bed 13 in this way, it is possible to detect the presence or absence of a person on the bed 13 and the position of the person on the bed 13.

Next, FIG. 7 shows an example of detecting the presence or absence of a mounted object on the mounting plate. 7A shows an example in which the weight sensor units of FIGS. 1 to 4 are attached to the back surface of the mounting plate, and FIG. 7B is a diagram showing a state in which the mounting object M is mounted on the mounting plate. ..
Examples of the objects in this example include baskets, products (commodities) housed in cases or placed on shelves, such as precious metals, foods, books, and the like.
Then, the weight sensor unit is attached to the mounting plate, the weight of the mounting plate and the mounted object is measured, and the presence / absence (presence / absence) of the mounted object on the mounting plate is detected.

The mounting plate 14 shown in FIG. 7A has a flat plate 14a formed of a metal material or a resin material. Then, as the back surface of the mounting plate 14 (plate 14a), the weight sensor units 1 shown in FIG. 1 are attached to the vicinity of the four corners of the back surface.
In this case, with the release paper covering the sticking layer 6 of the weight sensor unit 1 removed, four weight sensors 1 are attached by using the sticking layer 6 as shown in FIG. 7A.

Also in the embodiment shown in FIGS. 7A and 7B, although not shown, the connection line 7 led out from each weight sensor unit 1 is located at the center of the back surface of the plate 14a, as in the usage examples shown in FIGS. It is connected to the attached arithmetic control unit 11. Then, the load information is output from the arithmetic control unit 11 to the display unit 12.
The calculation control unit 11 does not necessarily have to be attached to the back surface of the plate 14a, and may be provided outside the plate 14a.

Then, the ground contact surface 4b of the ground contact member 4 protruding from the weight sensor unit 1 is positioned on the horizontal plane 15, for example, on the basket, the bottom surface of the case, or on the shelf.
After that, the load information from the four weight sensor units 1 can be obtained by placing the object M on the upper surface of the plate 14a and applying a load.
In this case, the total load information of the plate 14a and the mounted object M is obtained, but the weight of the mounted object M or the like can be obtained by subtracting the load of the plate by the arithmetic processing unit 11.
Then, from the predetermined arithmetic control unit (CPU) and display unit connected to the weight sensor unit 1, it is possible to display the presence / absence or the weight of the object M required by the user.

Although the mounting plates 14 shown in FIGS. 7A and 7B can be used alone, a large number of mounting plates 14 are arranged side by side in a section on a horizontal plane having a relatively large area such as a warehouse, and the mounting plates 14 are placed. By weighing the entire product mounted on the plate 14, it can be used for product inventory management and the like.
Further, in the above-mentioned mounting plate 14, four weight sensor units 1 are used, but the number may be increased or decreased to 2, 6, or 8 as needed.

(Second Embodiment of Weight Sensor Unit)
A second embodiment of the weight sensor unit 1 will be described with reference to FIGS. 8A-8C. In the weight sensor of the second embodiment, the members corresponding to the weight sensor unit of the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted as appropriate.

As shown in the figure, the weight sensor unit 1 includes a load cell built-in base 2, a load cell 3, and a grounding member 4, and a spherical protrusion 3d is formed on the load cell 3 incorporated in the load cell built-in base 2.
On the other hand, in the grounding member 4, a metal push plate 8 that abuts on the spherical protrusion 3d of the load cell 3 and presses the spherical protrusion 3d is arranged in parallel with the grounding surface 4b of the grounding member 4.
An adhesive layer 6 is formed on the back surface of the load cell built-in base 2, and four screws are used to fasten the load cell built-in base 2 to the cover case 5 at four corners of the surface opposite to the laying side of the adhesive layer 6. The boss 2e is erected.

According to the weight sensor unit 1 shown in FIGS. 8A to 8C, the metal push plate 8 arranged on the grounding member 4 side abuts on the spherical protrusion 3d on the load cell 3 side to apply a load to the strain generating body 3A. Acts to add the corresponding deflection.
According to this configuration, the eccentric load acting on the load cell 3 is effectively absorbed by the spherical protrusion 3d described above, which can contribute to improving the output accuracy of the load information by the load cell 3.
Further, according to the weight sensor unit 1, the load cell built-in base 2 is provided with a mounting portion for the cover case 5 that covers the entire back surface of the plate 14a, that is, four screw fixing bosses 2e, so that the cover case 5 is provided. The weight sensor unit 1 can be easily attached to the bottom surface of the.

(Example of mounting state (using state) of the weight sensor unit of the second embodiment)
In the mounted state (used state) of the second embodiment of the weight sensor unit 1, as shown in FIGS. 9 and 10, a through hole formed in the back surface of the cover case 5 that covers the entire back surface of the plate 14a. The ground surface 4b of each weight sensor 1 is assembled so as to protrude from the cover case 5 via 5a, and the upper surface thereof is used by using the adhesive layer 6 provided on the load cell built-in base constituting each weight sensor unit 1. A configuration in which a plate 14a is attached to the surface is adopted.

As shown in FIG. 9, the weight sensor unit 1 used for the mounting plate 14 is provided with a load cell built-in base 2, a load cell 3, and a grounding member 4, and is formed in a cover case 5 that covers the entire back surface of the mounting plate 14. In the through hole 5a, the grounding surface 4b of the grounding member 4 is attached in a state of protruding from the cover case 5.
In this embodiment, a screw fixing boss 5f is formed at an appropriate position on the inner surface of the lower bottom portion of the cover case 5 so that the load cell built-in base 2 can be fastened with the screw 16.
Therefore, with the four sets of weight sensor units 1 fastened to the cover case 5 with screws 16, the mounting plate 12 is attached to the upper surface of the adhesive layer 6 provided on the back surface of each load cell built-in base 2. Then, the mounting plate 14 can be assembled.

Further, in the cover case 5 used for the mounting plate 14, a storage space 5A for a circuit board, a battery, or the like is formed at an end portion in the longitudinal direction, and the storage space 5A is closed by the lid body 5B. .. Further, a battery lid 5C is detachably attached to the lid 5B. In addition, only the connection line 7 may be arranged in the accommodation space 5A of the mounting plate 14, and the circuit board and the battery may be provided outside the mounting plate 14 without arranging the circuit board and the battery.

According to the mounting plate 14, as shown in FIG. 10, the entire back surface of the mounting plate 14 is covered by the cover case 5, and the grounding surface 4b of the grounding member 4 protrudes near the four corners of the cover case 5. It is composed.
Therefore, according to the mounting plate 14, it is possible to provide a mounting plate 14 having a good appearance.

Then, the grounding member 4 is arranged in a state of being inserted into the through hole 5a formed in the cover case 5 that covers the entire back surface of the mounting plate. Therefore, when an excessive load is applied, the grounding member 4 is placed under the cover case 5. It acts so that the bottom surface touches the ground and receives a part of the load.
Therefore, the same effect as that of the weight scale of the first form can be obtained in that the strain-causing body 3A of the load cell 3 can be prevented from being permanently deformed.

In the mounting plate 14 of the second form shown in FIG. 9, for example, a tempered glass plate is used as the plate 14a, and a display for displaying the measured value of the load obtained by the load cell 3 on the back surface of the tempered glass plate. It is possible to realize a configuration including. According to this configuration, for example, the mounting plate 14 can be used as an electronic weight scale used in a general household or the like.

1 Weight sensor unit 1A Load cell unit 2 Load cell built-in base 2b Step part 2c Notch 2d Engagement recess 3 Load cell 3A Distortion body 3B Strain gauge 3a Outer frame 3b Slit 3c Tongue-shaped part 3d Spherical protrusion 4 Grounding member 4b Grounding surface 4d Contact part 5 Cover case 5a Through hole 5b Engagement protrusion 5d Notch part 5e Connection line insertion part (cord port)
6 Adhesive layer 7 Connection line 8 Metal push plate 10 Poly tank 11 Calculation control unit 12 Display unit 13 Bed 14 Mounting plate 14a Plate

Claims (5)

A load cell unit in which a load cell including a strain-causing body is incorporated, a sticking layer provided on the load cell unit to attach the load cell unit to the object, and an arithmetic control unit that arithmetically processes a detection signal from the load cell. With at least a connecting line to connect to,
In the weight sensor unit in which the load cell unit is attached to an object by the attachment layer and the presence or absence or weight of the object is detected by the load cell unit.
The load cell unit
A load cell built-in base that incorporates a load cell containing a strain generator,
A grounding member made of a resin material that abuts a part of the load cell incorporated in the load cell built-in base and applies a load of the object to the strain-causing body to add bending to the strain-causing body.
Spherical protrusions formed on the strain-causing body of a metal material,
A metal push plate provided on the grounding member and pressing the spherical protrusion,
A cover case that covers a part of the load cell and the grounding member by having a through hole through which the grounding member is inserted and projecting the grounding surface of the grounding member to the outside and being attached to the load cell built-in base.
With
The sticking layer is provided on the load cell built-in base, and the load cell built-in base is stuck to the object by the sticking layer.
Due to the load of the object, the grounding member retracts into the through hole, so that the strain-causing body is bent through the metal push plate and the spherical protrusion provided on the grounding member.
When the object weighs more than a predetermined weight, the ground contact surface of the ground contact member retracts into the through hole, and the lower bottom surface of the cover case touches the ground to receive a part of the load and cause strain. A weight sensor unit characterized by reducing the load acting on the body. The strain-causing body includes an outer frame and a tongue-shaped portion connected to the outer frame via a slit, the outer frame is held by the load cell built-in base, and a part of a grounding member is attached to the tongue-shaped portion. The weight sensor unit according to claim 1, wherein the weight sensor unit is brought into contact with the material to cause bending of the strain-causing body. In a state where the cover case is attached to the load cell built-in base, an insertion portion of a connection line connecting the load cell built-in base and the cover case is formed.
The weight sensor unit according to claim 1, wherein a connecting line to the load cell is led out from the cover case through the respective insertion portions that communicate with each other. The object includes a mounting plate on which the object is placed.
The weight sensor unit according to any one of claims 1 to 3, wherein the load cell unit is attached to the mounting plate by the attachment layer. The weight sensor unit according to claim 4, wherein the load cell built-in base is provided with a mounting portion of a cover case that covers the entire back surface of the mounting plate.

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