KR102063579B1 - Sensor Anchor Bolt For Measuring Load Of Freight Loaded On Forklift Using Strain Gage - Google Patents

Abstract

The present invention relates to a sensor anchor bolt for a forklift for measuring load of a cargo loaded on the forklift using a strain gauge, and more specifically, senses the load on a fork pocket of the forklift based on an electrical signal output from the strain gauge provided in the anchor bolt connecting a drive chain of the forklift.

Description

Sensor Anchor Bolt For Measuring Load Of Freight Loaded On Forklift Using Strain Gage}

The present invention relates to a forklift sensor anchor bolt for measuring the load of the cargo loaded on the forklift by using a strain gauge, and more particularly, an electrical signal output from the strain gauge provided in the anchor bolt connecting the drive chain of the forklift On the basis, relates to a sensor anchor bolt for a forklift with a built-in strain gauge for detecting the load applied to the forklift of the forklift.

A forklift truck is a vehicle that loads a relatively heavy weight, transports it to a desired location, and then lifts and descends to a height desired by a worker, and is widely used throughout the industry.

Forklifts have appropriate loading loads for each size and application. However, if the work load exceeds the loading weight, or if the center of gravity of the fork for loading the load due to immature operation or the weight of the load is severely unbalanced, the work may occur due to personal accidents caused by the falling of the forklift, falling of the forklift, or overturning. It may cause a safety hazard.

In order to prevent the falling of the cargo, the falling of the forklift, or the overturning of the forklift, the forklift can calculate the loading weight in real time and analyze the data to provide the prediction result for the present situation or the future situation. It is possible to reduce the overall logistics cost.

As a means for measuring the weight of the cargo loaded on the forklift, the strain gauge is more competitive in terms of price compared to the conventional load cell method has been used a lot. In order to easily install an additional device for measuring the weight of the forklift by using the strain gauge without complicated installation process, the forklift of the forklift is connected to the forklift without limiting the movement during driving. There is a need to develop anchor bolts with sensors that can measure accurate loads.

The present invention provides a forklift sensor anchor bolt for detecting the load applied to the forklift of the forklift based on the electrical signal output from the strain gauge provided in the anchor bolt connecting the drive chain of the forklift. For the purpose of

In order to solve the above problems, the present invention is a sensor anchor bolt that is connected to one end of the drive chain for driving the carriage forklift attached to the forklift, a thread is formed on a portion of the outer peripheral surface can be coupled to the mast of the forklift, A chain coupling part to which the driving chain is coupled; Threaded portion to which the nut can be coupled; A body part positioned between the chain coupling part and the screw thread part; A strain gauge accommodated in an inner hole of the body portion to measure strain; A lead wire exposure hole formed in the body portion to expose the lead wire of the strain gauge; A substrate unit receiving the output signal of the strain gauge and connected to an external device through a connection line; And a substrate protection unit configured to receive and protect the substrate unit, wherein the substrate unit comprises: a gauge signal processing unit for deriving a digital signal based on an output signal of the strain gauge; And a controller which derives the weight of the cargo loaded on the forklift based on the derived digital signal.

In one embodiment of the present invention, the substrate portion has a ring shape surrounding the body portion, and may be electrically connected to the lead wire of the strain gauge exposed through the lead wire exposure hole.

In one embodiment of the present invention, the substrate protection unit, the through hole can accommodate the screw thread and the body portion, the through hole formed through the center of the substrate protection portion; At least one bolt hole formed at a side thereof so that a bolt for fixing the substrate protection part to the body part may be inserted at a side thereof; A gauge wire groove in which a lead wire of the strain gauge can be accommodated and formed in an inner surface of the through hole; And a connection line groove formed at a lower end of the substrate protection part to expose the connection line of the substrate part to the outside from the substrate protection part.

In one embodiment of the present invention, a locking jaw is formed on the upper side of the body portion, the upper side of the substrate protection portion is in contact with the locking jaw, the substrate protection portion and the substrate portion as a whole has a cylindrical shape, in the inner central hole It can surround the body part.

In one embodiment of the present invention, the sensor anchor bolt further comprises an epoxy molding layer disposed under the substrate portion to protect the substrate from the outside, the substrate portion is a space inside the substrate protection portion and the epoxy molding layer Can be placed in.

In one embodiment of the present invention, the gauge signal processing unit, the signal receiving unit for receiving an output signal through the electrical connection of the lead wire of the strain gauge and the substrate portion; A signal converter converting the received output signal; And a signal output unit configured to output the converted output signal to the controller, wherein the signal converter comprises: a low noise amplifying step of amplifying the received output signal of the strain gauge to minimize noise; A high frequency blocking step of blocking high frequency components of the output signal which have passed the low noise amplifying step; And a digital conversion step of converting the output signal through the high frequency blocking step into a digital signal.

In one embodiment of the present invention, the control unit, the initial voltage value measuring step of measuring the initial voltage value of the unloaded state based on the digital signal output from the gauge signal processing unit of the sensor anchor bolt; A reference voltage table correction step of correcting a reference voltage table based on the measured initial voltage value; A load voltage measuring step of measuring a voltage value of a state in which cargo is loaded on the forklift based on the digital signal output from the gauge signal processing unit of the sensor anchor bolt; And a load derivation step of deriving the weight of the loaded cargo according to the voltage value measured based on the corrected reference voltage table.

In one embodiment of the present invention, the control unit, included in the forklift driving device for driving the forklift, receiving the output signal of the two or more sensor anchor bolts, the weight and balance of the load loaded on the forklift Can be derived.

In one embodiment of the present invention, the signal output unit may output the converted output signal to the control unit of the forklift driving device for driving the forklift.

In one embodiment of the present invention, the reference voltage table correction step may correct the reference voltage table according to a linear interpolation method.

According to an embodiment of the present invention, by processing the output signal of the strain gauge of the sensor anchor bolt to derive the weight of the cargo loaded on the forklift, when the load weight of the forklift exceeds or the center of the forklift loading the load is imbalanced It can be effective to prevent dangerous situations such as

According to an embodiment of the present invention, by correcting the reference voltage table, which is a reference for deriving the load by compensating for the disadvantages of the physical characteristics of the strain gauge built into the sensor anchor bolt, the cargo carried on the forklift of the forklift more accurately It can exert the effect of deriving the weight of.

According to an embodiment of the present invention, by fixing the substrate portion for processing the output signal of the strain gauge of the sensor anchor bolt by forming an epoxy molding layer on the substrate protection portion, it is possible to achieve the effect of protecting the substrate portion from external impact. .

According to an embodiment of the present invention, by replacing the anchor bolt used in the forklift with a sensor anchor bolt without having to attach a load sensor to the forklift, an effect of detecting a load applied to the forklift can be exerted.

According to an embodiment of the present invention, the circuit provided with the sensor anchor bolts converts the output signal of the strain gauge into a digital signal, thereby preventing errors occurring during transmission and transmitting the measured information without errors by preventing them from being affected by noise. It can exert an effect.

According to an embodiment of the present invention, the substrate unit for processing the output signal of the strain gauge of the sensor anchor bolt may be provided in the sensor anchor bolt to achieve the effect of processing the output signal.

1 is a view schematically showing a forklift truck.
2 is a diagram schematically illustrating a forklift driving device having a sensor anchor bolt according to an embodiment of the present invention.
FIG. 3 is a three-sided view schematically illustrating a sensor anchor bolt which does not combine a substrate portion and a substrate protection portion according to an embodiment of the present invention.
4 is a perspective view and a plan view schematically showing a substrate unit according to an embodiment of the present invention.
5 is a front view, a bottom view, and a perspective view schematically showing a substrate protection unit according to an embodiment of the present invention.
FIG. 6 is a side view and a cross-sectional view schematically illustrating a sensor anchor bolt combining a substrate unit and a substrate protection unit according to an exemplary embodiment of the present invention.
FIG. 7 is a diagram schematically illustrating components of a strain gauge and a substrate of a sensor anchor bolt according to an embodiment of the present invention.
8 is a diagram schematically illustrating a forklift driving device having a sensor anchor bolt according to an embodiment of the present invention.
9 schematically illustrates an internal configuration of a gauge signal processing unit according to an embodiment of the present invention.
10 schematically illustrates an operation of a signal processor according to an embodiment of the present invention.
11 schematically illustrates an operation step of a control unit according to an embodiment of the present invention.
Figure 12 schematically shows a graph showing the ADC measurement value of the sensor anchor bolt according to the weight of the loaded cargo of the forklift according to an embodiment of the present invention.
FIG. 13 schematically illustrates a graph applying linear interpolation to an output signal of a sensor anchor bolt according to an embodiment of the present invention.
FIG. 14 schematically illustrates a reference voltage table serving as a reference for deriving a weight of a cargo loaded on a forklift truck based on an initial voltage value measured by a controller according to an embodiment of the present invention.

In the following, various embodiments and / or aspects are now disclosed with reference to the drawings. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of one or more aspects. However, it will also be appreciated by one of ordinary skill in the art that this aspect (s) may be practiced without these specific details. The following description and the annexed drawings set forth in detail certain illustrative aspects of the one or more aspects. However, these aspects are exemplary and some of the various methods in the principles of the various aspects may be used and the descriptions described are intended to include all such aspects and their equivalents.

As used herein, “an embodiment”, “an example”, “aspect”, “an example”, etc., may not be construed as having any aspect or design described being better or advantageous than other aspects or designs. .

In addition, the term “or” is intended to mean an inclusive “or” rather than an exclusive “or”. In other words, unless specified otherwise or unambiguously in context, "X uses A or B" is intended to mean one of the natural implicit substitutions. That is, X uses A; X uses B; Or where X uses both A and B, "X uses A or B" may apply to either of these cases. Also, it is to be understood that the term "and / or" as used herein refers to and includes all possible combinations of one or more of the related items listed.

In addition, the terms "comprises" and / or "comprising" mean that such features and / or components are present, but exclude the presence or addition of one or more other features, components, and / or groups thereof. It should be understood that it does not.

In addition, terms including ordinal numbers such as first and second may be used to describe various components, but the components are not limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as the second component, and similarly, the second component may also be referred to as the first component. The term and / or includes a combination of a plurality of related items or any item of a plurality of related items.

In addition, in the embodiments of the present invention, unless otherwise defined, all terms used herein including technical or scientific terms are generally understood by those skilled in the art to which the present invention belongs. Has the same meaning as Terms such as those defined in the commonly used dictionaries should be interpreted as having meanings consistent with the meanings in the context of the related art, and ideally or excessively formal meanings, unless explicitly defined in the embodiments of the present invention. Not interpreted as

1 is a view schematically showing a forklift truck.

As illustrated in FIG. 1, the forklift includes a vehicle body 2000 on which a vehicle driving source such as a motor is mounted, and a forklift driving device 1000 that can be loaded in front of the vehicle body 2000. The forklift driving device 1000 may include a mast 500 disposed in a vertical direction and a carriage 100 capable of lifting up and down along the mast 500. The carriage 100 can be lifted up and down by the drive chain 200 or the like, and a pair of fork lifters 110 for lifting cargo are mounted in front of the carriage 100. In general, such a fork foot 110 is mounted to be adjustable in width can be used to adjust the width of the fork foot 110 according to the type of cargo.

A driver's seat is provided at an upper portion of the vehicle body 2000, and an overhead guard for protecting a driver is provided at the driver's seat. In addition, a front wheel may be mounted to the front of the vehicle body 2000, a rear wheel may be mounted to the rear, and a counter weight may be positioned above the rear wheel. The counter weight is to move the center of gravity of the cargo concentrated in the front of the vehicle body to the rear, to stably transport the cargo.

2 is a view schematically showing a forklift driving device 1000 provided with a sensor anchor bolt 10 according to an embodiment of the present invention.

As shown in Figure 2, the forklift driving device 1000 of the forklift according to an embodiment of the present invention is a forklift 110 is attached to the carriage 100 that can move up and down; A piston for driving up and down; A guide roller 400 connected to the piston to move up and down; A drive chain 200 connected to the carriage 100 via the guide roller 400 to move the carriage 100 up and down by driving the piston; A mast (500) provided with the drive chain (200), the guide roller (400) and the piston therein, and providing a guide when the carriage (100) moves up and down; And a sensor anchor bolt 10 having one end connected to the drive chain 200 and having a screw thread formed on a portion of an outer circumferential surface thereof, which may be coupled to the mast 500 of the forklift.

One end of the driving chain 200 is fixed to the carriage 100 by a sensor anchor bolt 10.1, and the other end thereof is connected to the mast 500 by a sensor anchor bolt 10.2. The anchor bolt 10 is inserted into the through hole provided in the carriage 100 or the mast 500, so that the anchor bolt 10 is not separated from the through hole by a nut 20 coupled to the anchor bolt 10. Can be fixed.

In the embodiment shown in Fig. 2, two sensor anchor bolts 10.1 and 10.2 are fixed by two nuts 21.1, 22.1, 21.2 and 22.2, respectively, so that the carriage 100 and the mast of the forklift truck respectively. It may be fixed to 500.

Strain gauge 140 for measuring the load of the load accommodated in the sensor anchor bolt of the present invention can be easily damaged by an external impact. Therefore, the sensor anchor bolt 10 may be installed at a portion connecting the fork foot 110 and the drive chain 200 of the forklift of FIG. 2 so that precise measurement may be performed without directly affecting the cargo.

The drive chain 200 coupled to the anchor bolt is installed via the guide roller 400. At this time, the guide roller 400 is connected to the piston 300 may move up and down as the piston 300 moves up and down.

As shown in FIG. 2, one end of the drive chain 200 is coupled to a fixed mast 500. At this time, when the guide roller 400 is raised, the drive chain 200 is also raised. However, since one end of the drive chain 200 is fixed by the sensor anchor bolt 10.2, the other end of the drive chain 200 is pulled up. The sensor anchor bolt 10 may be fixed to both ends of the drive chain 200 is also connected to the other fork feet 110 by the sensor anchor bolt. The sensor anchor bolt 10 may sense a load applied to the sensor anchor bolt 10 by the strain gauge 140 accommodated therein. As such, by detecting the load applied to the sensor anchor bolt 10, the load applied to the forklift 110 may be derived.

At this time, the forklift driving device 1000 further includes a controller (not shown) of the forklift driving device, and receives the load sensed by the sensor anchor bolt 10 and is loaded on the forklift 110. The forklift 110 may be controlled to prevent falling of the cargo or falling / overturning of the forklift by the loaded cargo, or the movement of the forklift may be controlled.

3, 4, and 5 schematically show the components of the sensor anchor bolt 10 according to an embodiment of the present invention.

FIG. 3 is a schematic three-dimensional view of the sensor anchor bolt 10 without coupling the substrate unit 160 and the substrate protection unit 170 according to an exemplary embodiment of the present invention.

As shown in FIG. 3, the sensor anchor bolt 10 has one end connected to a driving chain 200 for driving a carriage to which the forklift 100 of the forklift is attached, and a thread is formed on a part of the outer circumferential surface of the forklift. As a sensor anchor bolt 10 that can be coupled to the mast 500,

A chain coupling part 110 to which the driving chain 200 is coupled; Threaded portion 120 to which the nut can be coupled; A body portion 130 positioned between the chain coupling portion 110 and the threaded portion 120; A strain gauge 140 accommodated in the inner hole 190 of the body 130 to measure strain; A lead wire exposure hole 150 formed in the body 130 to expose the lead wire of the strain gauge 140; A substrate unit 160 which receives an output signal of the strain gauge 140 and is connected to an external device through a connection line; It includes; and a substrate protection unit 170 for receiving and protecting the substrate.

Specifically, FIGS. 3A, 3B, and 3C illustrate a front surface of the sensor anchor bolt 10 in which the substrate unit 160 and the substrate protection unit 170 are not coupled to each other according to an embodiment of the present invention. Fig., Side view and plan view.

Referring to FIG. 3A, the sensor anchor bolt 10 that does not couple the substrate 160 and the substrate protector 170 has a chain coupling part 110 and a nut to which the driving chain 200 is coupled. There is shown a threaded portion 120, a chain coupling portion 110 and a body portion 130 positioned between the threaded portion 120 that can be coupled. The threaded portion 120 may include a threaded portion, and may adjust a position at which the drive chain 200 is fixed to the carriage 100 or the mast 500 by changing the engagement position of the nut by rotating the coupled nut. In addition, by changing the position of the nut it is possible to change the relative position of the chain coupling portion 110 of the sensor anchor bolt 10 is connected to the carriage 100 or the mast 500. By changing the position of the chain coupling portion 110, it is possible to adjust the position of the drive chain 200 is connected to the chain coupling portion 110, through which it is possible to adjust the tension applied to the drive chain 200. Alternatively, when the carriage 100 is driven by the piston 300, by adjusting the position of the carriage 100 according to the position of the piston to adjust the driving range of the carriage 100, or the left and right of the carriage 100 You can adjust the balance.

In addition, as shown in (c) of FIG. 3, in one embodiment of the present invention, the inner hole 190 in which the strain gauge 140 is accommodated in the center of the body portion 130 of the sensor anchor bolt 10. Is formed. The strain gage 140 inserted into the inner hole 190 and outputs information about the load applied to the sensor anchor bolt 10 as an electrical signal. Referring to FIG. 3B, a lead wire of one or more strain gauges 140 may be exposed to the outside of the body 130 through the lead wire exposure hole 150 formed in the body 130. The electrical signal output from the strain gauge 140 is output through the lead wire of the strain gauge 140 exposed to the outside of the body 130. Thereafter, the lead wire of the strain gauge 140 may be connected to the substrate unit 160, and the substrate unit 160 may receive an electrical signal output from the strain gauge 140.

In another embodiment of the present invention, one side of the body portion 130 of the sensor anchor bolt 10, the outer groove in which the strain gauge 140 is accommodated; (not shown) may be formed. As shown in FIG. 3, not only the two-row sensor anchor bolt 10 in which one groove is broken in the chain coupling part 110 and the coupling portion is divided into two rows, but also the first-row sensor anchor bolt 10 without grooves, 2. Sensor anchor bolts (10) in which three grooves are coupled and the coupling portion is divided into three rows, and four rows of sensor anchor bolts (10) in which three grooves are coupled and the coupling portions are divided into four rows. The form of (10) is various. In an embodiment of the present invention, when the inner hole 190 is formed in the center of the body portion 130 of the sensor anchor bolt 10 to accommodate the strain gauge 140, a two-row sensor as shown in FIG. The anchor bolt 10 can accommodate the strain gauge 140 through the inner hole 190, but there are no grooves in the chain coupling portion 110 or a plurality of grooves in which a plurality of grooves are broken, such as one row, three rows, four rows, and the like. In the case of the sensor anchor bolt, it may be difficult to form the inner hole 190 for receiving the strain gauge 140. Accordingly, when it is difficult to form the inner hole 190 in the body portion 130 of the sensor anchor bolt 10, the outer groove in which the strain gauge 140 is accommodated on one side of the body portion 130; Strain gauge 140 may be accommodated in the sensor anchor bolt 10 by forming a).

The outer groove formed on one side of the body portion 130; (not shown) when the strain gauge 140 is accommodated, to form an epoxy molding layer for fixing the strain gauge 140, strain gauge 140 is Can be fixed. The lead wires of the fixed one or more strain gauges 140 are exposed to the outside grooves (not shown). The electrical signal output from the strain gauge 140 is output through the lead wire of the strain gauge 140 exposed to the outside of the body 130. Thereafter, the lead wire of the strain gauge 140 may be connected to the substrate unit 160, and the substrate unit 160 may receive an electrical signal output from the strain gauge 140.

4 is a perspective view and a plan view schematically showing the substrate unit 160 according to an embodiment of the present invention.

Specifically, FIG. 4 illustrates a substrate unit 160 that is electrically connected to the lead wires of one or more strain gauges 140 exposed through the lead wire exposure holes 150 described above. The substrate 160 has a ring shape surrounding the body 130 and is electrically connected to the lead wire of the strain gauge 140 exposed through the lead wire exposure hole 150.

4A is a perspective view of the substrate unit 160. As shown in FIG. 4, the substrate unit 160 is configured on an annular substrate surrounding the body 130 of the body of the sensor anchor bolt 10. The substrate unit 160 may be connected by a connection line and connected to an external device. 4B illustrates a plan view of the substrate unit 160. As shown in (b) of FIG. 4, at least one bolt hole 163 is formed in the annular substrate to fix the substrate protecting portion 170 of the sensor anchor bolt 10, and a circuit for measuring the load of the forklift on the substrate. The components of may be arranged.

The substrate unit 160 may convert an output signal of the strain gauge 140 into a digital signal and transmit the digital signal to the outside. As such, by converting the output signal of the strain gauge 140 into a digital signal, an error occurring during transmission can be prevented and the measured information can be transmitted without error by being not affected by noise.

5A, 5B, and 5C are a front view, a bottom view, and a perspective view schematically showing a substrate protection unit 170 according to an embodiment of the present invention.

In detail, the substrate protection unit 170 may include the threading unit 120 and the body unit 130, and a through hole 175 formed through the center of the substrate protection unit 170; At least one bolt hole 171 formed at a side thereof so that a bolt for fixing the substrate protector 170 to the body 130 may be inserted at a side thereof; A gauge wire groove 172 formed on an inner surface of the through hole 175 and capable of accommodating a lead wire of the strain gauge 140; And a connection line groove 173 formed at a lower end of the substrate protection unit 170 to expose the connection line of the substrate unit 160 to the substrate protection unit 170 to the outside.

5A is a front view of the substrate protection part 170. As shown in FIG. 5A, a bolt for fixing the substrate protector 170 to the body 130 of the sensor anchor bolt 10 may be inserted at the side of the substrate protector 170. And at least one bolt hole 171 formed at a side surface thereof and a connection line groove 173 formed at a lower end of the substrate protection unit 170 to expose the connection line connected to the substrate unit 160 to the outside from the substrate protection unit 170. do.

5B is a bottom view of the substrate protection part 170. The substrate protection unit 170 includes one or more bolt holes 174 formed therein so that bolts for fixing the substrate unit 160 to the substrate protection unit 170 can be inserted therein, and the bolts 174 are bolted to the bolt holes 174. By inserting the substrate 160 may be fixed to the substrate protection unit 170. In addition, as shown in FIG. 5B, the substrate protection unit 170 may accommodate the threaded portion 120 and the body portion 130, and the center of the substrate protection unit 170 may be disposed. It includes a through hole 175 formed through.

5C is a perspective view of the substrate protection unit 170. As shown in (c) of FIG. 5, the substrate protection part 170 is formed through a center of the substrate protection part 170 that can accommodate the screw thread 120 and the body 130. 175). The upper side of the substrate protection unit 170 is in contact with the locking step of the body 130.

The substrate protection part 170 and the substrate part 160 have a cylindrical shape as a whole, and the body part 130 through the bolt hole 171 formed at the side so that a bolt for fixing to the body part 130 can be inserted from the side. Can be fixed). In addition, the substrate protection unit 170 may accommodate the lead wire of the strain gauge 140, and includes a gauge wire groove 172 formed on the inner surface of the through hole 175. The lead wires of the strain gauges 140 are exposed to the inside of the substrate protection unit 170 fixed to the body 130, and the lead wires of the strain gauges 140 are accommodated through the gauge wire grooves 172, thereby protecting the substrate. The lead wire of the strain gauge 140 may be exposed without damage to the inside of the 170 to exert an effect of being electrically connected to the substrate 160.

FIG. 6 is a side view and a cross-sectional view schematically illustrating a sensor anchor bolt 10 in which a substrate unit 160 and a substrate protection unit 170 are combined according to an embodiment of the present invention.

Specifically, the sensor anchor bolt 10 may serve as one sensory anchor bolt by assembling the components constituting the sensor anchor bolt 10 described with reference to FIGS. 3, 4, and 5. The above-mentioned components of the sensor anchor bolt 10 are assembled as shown in FIG. Cylindrical substrate protection portion 170 surrounds the body portion 130 of the sensor anchor bolt 10, the annular substrate portion 160 surrounding the body portion 130 is accommodated in the substrate protection portion 170 Can be. A component of a circuit (for example, a semiconductor element) for measuring the load of the forklift may be disposed on the upper surface of the substrate unit 160. The lower surface of the substrate portion may also be a component of the circuit (for example, a semiconductor element). (Not shown) may be disposed.

The substrate 160 stored therein is electrically connected to the lead wire of the strain gauge 140 exposed in the substrate protection unit 170. The substrate 160 receives an output signal of the strain gauge 140, and the substrate unit 160 receives the output signal. It may be output to an external device through a connection line connected to 160. The connection line of the substrate unit 160 is exposed to the outside from the substrate protection unit 170 through the connection line groove 173 formed at the lower end of the substrate protection unit 170.

Subsequently, an epoxy molding layer 180 is disposed below the substrate unit 160 accommodated through the epoxy molding process in order to fix the substrate unit 160. Through this, the substrate unit 160 is fixed to the substrate protection unit 170 in such a way that the circuit of the substrate unit 160 is not damaged, thereby exerting the effect of accurately measuring the load of the forklift without damage caused by external impact. Can be.

Figure 6 (b) shows a cross-sectional view of the sensor anchor bolt 10 completed in this form. The substrate unit 160 is stored and attached to the inside of the substrate protection unit 170 by using a bolt so as to be fixed to the substrate protection unit 170, and the lead wire exposure hole 150 inside the substrate protection unit 170. It may be electrically connected to the lead wire of the strain gauge 140 exposed through. The substrate unit 160 is disposed in an interior space between the substrate protection unit 170 and the epoxy molding layer 180 to protect the substrate unit 160 from an external environment. As shown in FIG. 6B, the connection line of the substrate unit 160 is exposed to the outside from the substrate protection unit 170 through the connection line groove 173 formed at the lower end of the substrate protection unit 170.

Through such a structure, the sensor anchor bolt 10 of the present invention forms the epoxy molding layer 180 on the substrate protection unit 170 by fixing the substrate 160 to process the output signal of the strain gauge 140, The effect which can protect a board | substrate part from an external shock can be exhibited.

7 is a view schematically showing the components of the strain gauge 140 and the substrate portion 160 of the sensor anchor bolt 10 according to an embodiment of the present invention.

Specifically, the strain gauge 140 of the sensor anchor bolt 10 is electrically connected to the lead wire of the strain gauge 140 exposed through the lead wire exposure hole 150 and the substrate 160. Strain applied to the sensor anchor bolt 10 is measured by the strain gauge 140, and the substrate unit 160 derives a digital signal based on an output signal of the strain gauge 140. A gauge signal processing unit 161; And a controller 162 for deriving the weight of the cargo loaded on the forklift based on the derived digital signal.

In addition, the forklift driving device 1000 for driving the forklift includes a control unit (not shown) that receives an output signal processed by the board unit of the two or more sensor anchor bolts 10. Separately from).

In the exemplary embodiment of the present invention, the strain of the sensor anchor bolt 10 is measured by the strain gauge 140 inside the sensor anchor bolt 10, and the strain is measured through the gauge signal processing unit 161 of the substrate unit 160. The output signal of the gauge 140 is processed. Thereafter, the controller 162 derives the weight of the cargo loaded on the forklift based on the digital signal processed and derived from the gauge signal processor 161.

In another embodiment of the present invention, the information on the output signal of the strain gauge or the weight of the cargo derived from each sensor anchor bolt 10 is transmitted to the controller (not shown) of the forklift driving device 1000 to Comprehensive cargo weight information loaded on the forklift 110 and the balance of the loaded cargo of the forklift can be derived. Accordingly, the driver of the forklift can exert an effect that can prevent a dangerous situation such as when the weight of the forklift exceeds the load or when the center of the forklift loading the load is imbalanced.

8 is a view schematically showing a forklift driving device 1000 provided with a sensor anchor bolt 10 according to an embodiment of the present invention.

Specifically, FIG. 8 is a front view of the forklift driving device 1000 as shown in FIG. 2. As shown in FIG. 8, in the exemplary embodiment of the present invention, the forklift 110 is attached to the carriage 100, and the sensor anchor bolt 10 is fixed to the carriage 100. The sensor anchor bolt 10 is connected to one end of the drive chain 200. The drive chain 200 is fixed to the mast 500 via the guide roller 400, the guide roller 400 is fixed to the piston to move up and down, so that the drive chain 200 and the drive chain 200 The connected carriage 100 is moved up and down.

In one embodiment of the present invention, the forklift driving device 1000 may be provided with two or more sensor anchor bolts (10). In this case, output signals processed by the substrate unit 160 of the two or more sensor anchor bolts 10 may be input to a controller (not shown) of the forklift driving device 1000. The sensor anchor bolts 10 may fix the driving chains 200 on the left and right sides to the carriage 100 to derive a load applied to the driving chains 200 connected to each other.

Therefore, the controller (not shown) of the forklift driving device 1000 may receive loads applied to the drive chains 200 on the left and right from two or more sensor anchor bolts 10, respectively. At this time, the control unit (not shown) of the forklift driving device 1000 may add the loads applied to the left and right drive chains 200 to derive the total load applied to the forklift 110, Deriving the difference in the load on the 200 may be derived the left and right balance of the cargo loaded on the forklift 110. For example, if the load sensed on the left sensor anchor bolt (10a) is 800kg, the load detected on the right sensor anchor bolt (10b) is 640kg, the total load of the cargo loaded on the forklift 110 is 1440kg to be. The cargo may be loaded in a form close to the center of gravity on the left side of the fork foot 110. In this case, when the forklift is turning to the right with reference to FIG. 8, since the cargo is centrifugal to the left and the cargo may fall or the forklift may be turned over by the cargo, the speed may be lowered when turning. By controlling or adjusting the height of the forklift 110 may be able to operate safely.

As such, the control unit (not shown) of the forklift driving device 1000 may contact the forklift 110 based on the position information of each sensor anchor bolt 10 and the output signal of each sensor anchor bolt 10. To grasp the information on the weight and balance of the loaded cargo, to control the movement of the forklift 110 or the forklift based on the information on the weight and balance, or to derive a signal informing the user of the danger of falling or overturning. Can be.

9 schematically illustrates an internal configuration of a gauge signal processing unit 161 according to an embodiment of the present invention.

9, the gauge signal processor 161 according to an embodiment of the present invention receives an output signal through an electrical connection between a lead wire of the strain gauge 140 and the substrate 160. A signal receiver 161.1; A signal converter 161.2 for converting the received output signal; And a signal output unit 161.3 for outputting the converted output signal to the control unit 162.

The signal receiver 161.1 receives information on the strain of the sensor anchor bolt 10 measured by the strain gauge 140. To this end, the lead wire of the strain gauge 140 is connected to the signal receiving unit 161.1 of the substrate 160, the electrical signal is transmitted to the signal receiving unit 161.1, the signal receiving unit 161.1 detects the electrical signal Can be received.

The signal converter 161.2 converts the output signal of the strain gauge 140 received by the signal receiver 161.1. The signal converter 161.2 may perform amplification, filtering, and the like to easily extract information on the strain from the output signal of the strain gauge 140. In addition, the signal converter 161.2 converts the converted output signal into a digital signal and transmits the converted signal to the controller 162 of the substrate unit 160 or the controller of the forklift driving device 1000, thereby receiving an error occurring during transmission. It is possible to transmit the measured information without error by preventing the noise and being influenced by the noise.

The signal output unit 161.3 outputs the output signal converted by the signal conversion unit 161.2 to the control unit 162 of the substrate unit 160 or the control unit (not shown) of the forklift driving device 1000. In one embodiment of the present invention, the signal output unit 161.3 transmits the output signal to the control unit 162 included in the substrate unit 160 to load the cargo loaded on the forklift 110 of the forklift in the control unit 162 The weight of can be derived.

In another embodiment of the present invention, the signal output unit 161.3 transmits an output signal to the control unit of the forklift driving device 1000 provided in the forklift to weigh and balance the load loaded on the forklift 110 of the forklift. Can be derived. In FIG. 9, the signal output unit 161.3 is connected to output a signal to the control unit 162 of the substrate unit 160. The signal output unit 161.3 is a control unit of the forklift driving device 1000. It may be connected to output a signal processed by (not shown).

10 schematically illustrates an operation step of the signal conversion unit 161.2 according to an embodiment of the present invention.

In one embodiment of the present invention, the signal conversion unit 161.2 includes: a gauge signal receiving step (S100) for receiving an output signal of the strain gauge 140 from the signal receiving unit 161.1; A low noise amplifying step (S110) of amplifying the received output signal of the strain gauge 140 to minimize noise; A high frequency blocking step (S120) of blocking high frequency components of the output signal passing through the low noise amplifying step (S110); And a digital conversion step (S130) of converting the output signal through the high frequency blocking step (S120) into a digital signal.

Specifically, in step S100, the signal converter 161.2 receives the output signal of the strain gauge 140 from the signal receiver 161.1.

In step S110, the signal converter 161.2 amplifies the output signal of the strain gauge 140 received from the signal receiver 161.1 to minimize noise.

In step S120, the high frequency component of the output signal passed through the low noise amplification step S110 is cut off. In the high frequency component blocking method, a high frequency component may be blocked by implementing a circuit using a low pass filter. In this way, the AC signal can be removed by cutting off the high frequency component.

In step S130, the output signal that has passed through the high frequency blocking step S120 is converted into a digital signal. The signal that has passed through the high frequency blocking step S120 is converted into an analog signal through an analog-to-digital converter.

The strain gauge 140 of the sensor anchor bolt 10 of the present invention can measure the strain due to the load applied to the fork foot 110 of the forklift in which the sensor anchor bolt 10 is installed.

At this time, the signal generated from the strain gauge 140 has a characteristic that only a DC component is output when a constant force is continuously applied. Therefore, when a constant load is applied to the forklift 110, the output of the strain gauge 140 appears only as a DC component, when the forklift raises or lowers the forklift 110, the strain gauge 140 The output of is expressed as the sum of AC and DC components.

At this time, the AC component has a signal having a high frequency characteristic. The signal converter 161.2 may perform a low noise amplification step S110 and a high frequency blocking step S120 in order to detect and filter the AC component of the high frequency characteristic.

11 schematically illustrates an operation step of the controller 162 according to an embodiment of the present invention.

As shown in FIG. 11, the control unit 162 measures an initial voltage value in the unloaded state based on a digital signal output from the gauge signal processing unit 161 of the at least one sensor anchor bolt 10. Initial voltage value measuring step (S200); A reference voltage table correction step (S210) of correcting a reference voltage table based on the measured initial voltage value; A load voltage measuring step (S220) of measuring a voltage value of a state in which cargo is loaded on the forklift based on the digital signal output from the gauge signal processing unit 161 of the at least one sensor anchor bolt 10; A load derivation step (S230) of deriving the weight of the loaded cargo according to the voltage value measured based on the corrected reference voltage table.

Specifically, in step S200, the control unit 162 measures the initial voltage value of the unloaded state based on the digital signal output from the gauge signal processing unit 161 of the at least one sensor anchor bolt (10). The strain gauge 140 accommodated in the inner hole 190 of the body portion of the sensor anchor bolt 10 measures a load each time the forklift is used, and thus repeatedly detects the load. The strain gauge 140 composed of the electrical resistance wire may not be the same as the resistance value of the strain gauge 140 after being repeatedly used and the resistance value of the strain gauge 140 used for the first time due to the environment in which the repetitive stimulus is given. Accordingly, in order to derive a more accurate weight in the process of deriving the cargo loaded on the forklift, it is necessary to recognize the initial voltage value applied to the resistance of the strain gauge 140 in the unloaded state in which no weight is loaded.

Accordingly, the controller 162 measures an initial voltage value applied to the resistance line of the strain gauge 140 in the unloaded state based on the digital signal output from the gauge signal processor 161.

In step S210, the controller 162 corrects the reference voltage table based on the measured initial voltage value. As described above, the strain gage 140 composed of an electrical resistance wire has a resistance value of the strain gage 140 for measuring the weight of a cargo for the first time due to an environment in which repeated stimulation is given, and the strain gage 140 after repeated use. May not be the same. In order to solve the problems caused by the physical characteristics of the strain gauge 140 to more accurately measure the weight of the loaded cargo of the forklift, the reference voltage table according to an embodiment of the present invention is the unloaded state measured in step S200 Is corrected based on the initial voltage value of.

The reference voltage table refers to table-type data that can determine the weight of the cargo based on the voltage value applied to the resistance of the strain gauge 140 that changes as the cargo is loaded on the forklift. Therefore, the controller 162 corrects the reference voltage table as a reference for deriving the weight of the loaded cargo based on the initial voltage value measured in step S200.

In the step S220, based on the digital signal output from the gauge signal processing unit 161 of the one or more sensor anchor bolts 10 measures the voltage value of the load loaded on the forklift. After the reference voltage table is corrected by performing the step S230, the control unit 162 measures the voltage value of the load of the forklift.

In step S230, the weight of the loaded cargo according to the voltage value measured in step S220 is derived based on the reference voltage table corrected in step S210.

In one embodiment of the present invention, the weight of the cargo derived by performing the step S200 to step S230 may be transmitted to the control unit (not shown) of the forklift driving device 1000 connected to the forklift. The controller (not shown) of the forklift driving device 1000 that receives the weight information of the cargo may derive the weight of the total cargo loaded on the forklift based on the weight information, or the cargo loaded on the two forklifts 110. You can also derive the balance of weight.

Figure 12 schematically shows a graph showing the ADC measurement value of the sensor anchor bolt 10 according to the weight of the loaded cargo of the forklift according to an embodiment of the present invention.

Specifically, FIG. 12 measures the voltage value (ADC value) applied to the resistance of the strain gauge 140 while constantly increasing the load at constant velocity at 200 kgf intervals from 0 kgf to 4000 kgf in four different sensor anchor bolts 10. The graph showing the result of performing the experiment is shown.

The graph shows the result of measuring the voltage value (ADC value) by repeating the experiment applying the same load to the four sensor anchor bolts 10 four times, and even if the same sensor anchor bolt 10, the initial voltage value of the four experiments This is shown differently. However, even if the initial voltage value is different, in the case of the same sensor anchor bolt 10, the slope of the graph representing the voltage value (ADC value) according to the weight is similarly shown.

As a result of the graph, it can be predicted that by linearly calibrating data based on initial voltage values that are different from each other, a more accurate weight of cargo loaded on a forklift truck can be derived. Even though the initial voltage value and the slope of the unloaded state are different, the measured values of the four sensor anchor bolts 10 change linearly, so that the sensor anchor bolts 10 of the present invention detect the error of the variation of the initial voltage value and the slope. If calibrated, the result can be used as a load weight sensor with uniform properties.

FIG. 13 schematically illustrates a graph applying linear interpolation to an output signal of a sensor anchor bolt according to an embodiment of the present invention.

The linear interpolation method is a method of linearly calculating along a straight line distance to estimate a value located between end points given a value of an end point. FIG. 13 illustrates an embodiment of a graph to which the linear interpolation method is applied due to the result that the graph excluding the initial voltage value of the sensor anchor bolt 10 changes linearly as shown in FIG. 12. According to the applied weight, the voltage value applied to the resistance of the strain gauge 140 of the sensor anchor bolt 10 changes linearly, and the control unit 162 performing the aforementioned reference voltage table correction step S120 is shown in FIG. 13. By linearly correcting the difference of the voltage value (ADC value) as shown, even if the initial voltage value measured in the no-load state is different, it can exert the effect of accurately deriving the weight of the cargo loaded on the forklift have.

FIG. 14 schematically illustrates a reference voltage table as a reference for deriving a weight of a cargo loaded in a forklift truck based on an initial voltage value measured by the controller 162 according to an embodiment of the present invention.

The controller 162 corrects the reference voltage table based on a linear interpolation method in performing the reference voltage table correction step (S210). As shown in FIG. 13, in deriving the weight of the cargo loaded on the forklift, the reference voltage table is a reference voltage table which is a reference for deriving more accurate weight of the loaded cargo based on the initial voltage value. Can be corrected. The voltage value measured according to the change of the resistance of the strain gauge 140 changes. The reference voltage table is corrected according to the linear interpolation method in order to solve a problem that the initial voltage value of the strain gauge 140 in the unloaded state is difficult to be constant due to the physical characteristics of the strain gauge 140.

According to the change of the resistance of the strain gauge 140 to which the repeated stimulus is applied, as shown in FIG. 13, even if the voltage value (ADC value) of the same value, the load value may be different for each table. The controller 162 adjusts the reference voltage table according to the linear interpolation method based on the initial voltage value measured by measuring the initial voltage value of the unloaded state before the load of each forklift truck is loaded, and based on the corrected reference voltage table. The load applied to the loaded forklift can be derived.

As such, by compensating for the shortcomings according to the physical characteristics of the strain gauge 140 accommodated in the inner hole 190 in the sensor anchor bolt 10, by correcting the reference voltage table as a reference for deriving the load, It can have the effect of deriving the weight of the cargo on the forklift.

In another embodiment of the present invention, a forklift driving device 1000 of the forklift includes a controller (not shown), and may be implemented in a state separated from the substrate unit 160. The control unit (not shown) of the forklift driving device 1000 receives the output signal of the strain gauge 140 of the sensor anchor bolt 10, like the control unit 162 of the substrate unit 160, and the above-described steps S200 to S-step. Step S230 may be performed, or two or more sensor anchor bolts may receive a signal for information on deriving the weight of the cargo loaded on the forklift, and may derive the weight and balance of the cargo loaded on the forklift.

By doing so, the sensor anchor bolt 10 of the present invention derives the weight of the cargo loaded on the forklift, thereby preventing a dangerous situation such as when the load weight of the forklift exceeds or the center of the forklift loading the load is imbalanced. It can be effective.

Although the embodiments have been described by the limited embodiments and the drawings as described above, various modifications and variations are possible to those skilled in the art from the above description. For example, the described techniques may be performed in a different order than the described method, and / or components of the described systems, structures, devices, circuits, etc. may be combined or combined in a different form than the described method, or other components. Or even if replaced or substituted by equivalents, an appropriate result can be achieved. Therefore, other implementations, other embodiments, and equivalents to the claims are within the scope of the claims that follow.

Claims (10)

As a sensor anchor bolt that is connected to the drive chain for driving the carriage attached to the forklift of the forklift, one end is formed on a portion of the outer peripheral surface can be coupled to the mast of the forklift,
A chain coupling part to which the driving chain is coupled;
Threaded portion to which the nut can be coupled;
A body part positioned between the chain coupling part and the screw thread part;
A strain gauge accommodated in an inner hole of the body portion to measure strain;
A lead wire exposure hole formed in the body portion to expose the lead wire of the strain gauge;
A substrate unit receiving the output signal of the strain gauge and connected to an external device through a connection line; And
And a substrate protection unit configured to receive and protect the substrate.
The substrate portion,
A gauge signal processing unit which derives a digital signal based on the output signal of the strain gauge; And
And a controller for deriving the weight of the cargo loaded on the forklift based on the derived digital signal.
The substrate protection unit,
A through hole accommodating the threaded portion and the body portion and formed through a center of the substrate protection portion;
At least one bolt hole formed at a side thereof so that a bolt for fixing the substrate protection part to the body part may be inserted at a side thereof;
A gauge wire groove in which a lead wire of the strain gauge can be accommodated and formed in an inner surface of the through hole; And
And a connection line groove formed at a lower end of the substrate protection part to expose the connection line of the substrate part to the outside from the substrate protection part.
The method according to claim 1,
The substrate portion,
A sensor anchor bolt having a ring shape surrounding the body portion and electrically connected to the lead wire of the strain gauge exposed through the lead wire exposure hole.
delete The method according to claim 1,
A locking step is formed on the upper side of the body part, the upper side of the substrate protection unit is in contact with the locking step,
The substrate protection portion and the substrate portion has a cylindrical shape as a whole, the sensor anchor bolt surrounding the body portion in the inner central hole.
The method according to claim 1,
The sensor anchor bolt further includes an epoxy molding layer disposed under the substrate to protect the substrate from the outside.
The substrate portion sensor anchor bolt is disposed in the space inside the substrate protection portion and the epoxy molding layer.
The method according to claim 1,
The gauge signal processing unit,
A signal receiver configured to receive an output signal through an electrical connection between the lead wire of the strain gauge and the substrate;
A signal converter converting the received output signal; And
And a signal output unit configured to output the converted output signal to the control unit.
The signal conversion unit,
A low noise amplifying step of amplifying the received output signal of the strain gauge to minimize noise;
A high frequency blocking step of blocking high frequency components of the output signal which have passed the low noise amplifying step; And
And a digital conversion step of converting the output signal through the high frequency blocking step into a digital signal.
The method according to claim 1,
The control unit,
An initial voltage value measuring step of measuring an initial voltage value in a no-load state based on a digital signal output from the gauge signal processing unit of the sensor anchor bolt;
A reference voltage table correction step of correcting a reference voltage table based on the measured initial voltage value;
A load voltage measuring step of measuring a voltage value of a state in which cargo is loaded on the forklift based on the digital signal output from the gauge signal processing unit of the sensor anchor bolt;
And a load deriving step of deriving the weight of the loaded cargo according to the voltage value measured based on the corrected reference voltage table.
The method according to claim 7,
The control unit,
Included in the forklift driving device for driving the forklift,
Receiving an output signal of the two or more sensor anchor bolts, to derive the weight and balance of the cargo loaded on the forklift, sensor anchor bolts.
The method according to claim 6,
The signal output unit,
The sensor anchor bolt may be output to the control unit of the forklift driving device for driving the forklift foot converted.
The method according to claim 7,
And the reference voltage table correction step corrects the reference voltage table according to a linear interpolation method.

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