Load cell and weighing vehicle

Abstract

To provide a load cell that allows for easy placement of a substrate near a strain gauge, and a vehicle equipped with a weighing function. [Solution] The load cell comprises a load cell body extending in a predetermined direction and subjected to deformation when a load is applied in a direction perpendicular to the predetermined direction, a bottomed cylindrical housing adjacent to the end of the load cell body in the predetermined direction and having an opening, and a substrate housed in the housing. The housing comprises a cylindrical portion and a bottom portion that closes one end of the cylindrical portion, and either the substrate or the bottom portion has a projection, while the other of the substrate or the bottom portion has an insertion hole, and the substrate is fixed to the bottom portion by the projection being inserted into the insertion hole.

Description

Technical Field

[0001] This specification relates to a load cell and a vehicle with a weighing function.

Background Art

[0002] For example, Patent Document 1 below discloses a pin-type load cell including a shaft member and a shear strain gauge (hereinafter also referred to as a strain gauge) adhered to a recess formed in the shaft member.

[0003] A load cell requires a substrate for applying a predetermined voltage to the strain gauge and deriving the load applied to the load cell from the change in the voltage output from the strain gauge. However, Patent Document 1 does not disclose anything about the arrangement of such a substrate. Since the wiring connecting the substrate and the strain gauge is preferably short from the viewpoints of noise suppression and miniaturization of the load cell, it is desirable to arrange the substrate near the strain gauge.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Therefore, the problem is to provide a load cell and a vehicle with a weighing function that can easily arrange a substrate near a strain gauge.

Means for Solving the Problems

[0006] [1] The load cell includes a load cell body extending in a predetermined direction and generating strain when a load is applied in a direction orthogonal to the predetermined direction, and a bottomed cylindrical housing portion having an opening and adjacent to an end portion of the load cell body in the predetermined direction, and The facility comprises a substrate housed in the aforementioned housing section, The housing comprises a cylindrical portion and a bottom portion that closes one end of the cylindrical portion. Either the substrate or the bottom is provided with a projection, and the other of the substrate or the bottom is provided with an insertion hole, and the substrate is fixed to the bottom by inserting the projection into the insertion hole.

[0007] [2] Furthermore, in the load cell described in [1] above, The housing section is equipped with an earth terminal located at its bottom. The ground wire extending from the aforementioned circuit board is connected to the ground terminal. This configuration is also acceptable.

[0008] [3] Furthermore, in the load cell described in [1] above, The bottom portion is provided with the projection made of metal, and the substrate is provided with the insertion hole. This configuration is also acceptable.

[0009] [4] Furthermore, vehicles equipped with weighing functions are A loading section capable of loading cargo, A vehicle section on which the aforementioned loading section is mounted, The system comprises one of the load cells [1] to [3] above, which is positioned between the loading section and the vehicle section. [Brief explanation of the drawing]

[0010] [Figure 1] Overall view of the vehicle with weighing function according to this embodiment [Figure 2] Cross-sectional view illustrating the arrangement of load cells according to this embodiment. [Figure 3] Front view of the load cell according to this embodiment [Figure 4] Figure 3, section view along line IV-IV [Figure 5] Side view of the load cell according to this embodiment [Figure 6]Exploded perspective view of the load cell according to this embodiment [Figure 7] Schematic diagram showing the connection state of the wiring between the battery, the indicator, and each load cell [Figure 8] Functional block diagram for explaining the configuration of the circuit section [Figure 9] Exploded perspective view of the load cell according to another embodiment

Modes for Carrying Out the Invention

[0011] In each drawing, the dimensions of the components may be enlarged or reduced with respect to the actual dimensions for ease of understanding, for example, and the dimensional ratios between the respective drawings may not match. In addition, in each drawing, a part of the components may be omitted for ease of understanding, for example.

[0012] Terms including ordinal numbers such as first, second, etc. are used to describe various components, but this term is used only for the purpose of distinguishing one component from another, and the components are not particularly limited by this term. Note that the number of components including ordinal numbers is not particularly limited, and may be, for example, one. Also, the ordinal numbers used in the following specification and drawings may be different from the ordinal numbers described in the claims.

[0013] Hereinafter, an embodiment of a load cell and a vehicle with a weighing function will be described with reference to FIGS. 1 to 8. The following embodiments are examples for assisting in understanding the configuration of the load cell and the vehicle with a weighing function, and do not limit the configuration of the load cell and the vehicle with a weighing function.

[0014] In the following description and each drawing, the first direction D1 is also referred to as the front-rear direction D1, the second direction D2 is also referred to as the left-right direction D2, and the third direction D3 is also referred to as the up-down direction D3. That is, each of the directions D1 to D3 is the direction as seen from a person (driver) sitting in the driver's seat in the cab 103a of the vehicle 100 with a weighing function when the vehicle 100 with a weighing function is running.

[0015] In the forward / backward direction D1, the direction of the arrow in the diagram is considered the forward direction, and the direction opposite to the direction of the arrow in the diagram is considered the backward direction. In the left / right direction D2, the direction of the arrow in the diagram is considered the left direction, and the direction opposite to the direction of the arrow in the diagram is considered the right direction. In the up / down direction D3, the direction of the arrow in the diagram is considered the up direction, and the direction opposite to the direction of the arrow in the diagram is considered the down direction.

[0016] As shown in Figure 1, the weighing vehicle 100 includes a loading section 101 on which loads can be loaded, a vehicle section 102 on which the loading section 101 is mounted, and a load cell 1 positioned between the loading section 101 and the vehicle section 102.

[0017] The weighing vehicle 100 may be equipped with multiple load cells 1. For example, the weighing vehicle 100 may be equipped with four load cells 1. The weighing vehicle 100 may also be equipped with a battery 105 capable of supplying power to each load cell 1, and an indicator 106 that displays the weighing results output from each load cell 1.

[0018] The loading section 101 may include a cargo box 101a and a subdeck frame 101b. The cargo box 101a may, for example, include a cargo box body 101c having a discharge opening at its rear end, and a tailgate 101d rotatably connected to the cargo box body 101c so as to open and close the discharge opening, as in this embodiment.

[0019] The subdeck frame 101b is a member that reinforces the cargo box 101a and is welded to the bottom wall of the cargo box 101a. The subdeck frame 101b may be, for example, rectangular in shape.

[0020] Furthermore, the loading section 101 may include a transmission section 101e located on the subdeck frame 101b, as shown in Figure 2. The loading section 101 may include, for example, four transmission sections 101e. The four transmission sections 101e are located at the four corners of the rectangular subdeck frame 101b.

[0021] The transmission section 101e transmits the weight of the load to the load cell 1. As shown in Figure 2, the transmission section 101e is a block-shaped member that protrudes from the subdeck frame 101b toward the vehicle section 102 side (downward). The transmission section 101e is equipped with a through hole 101f for the load cell. The inner diameter of the through hole 101f for the load cell is constant, and the load cell 1 is inserted through it.

[0022] The vehicle section 102 may include a vehicle body 103 and a rocking mechanism 104, as shown in Figure 1. The vehicle body 103 may include a driver's cab (also called a "cab") 103a and a chassis frame 103b extending rearward from the driver's cab 103a.

[0023] The rocking mechanism 104 is a mechanism that rocks the loading section 101 relative to the chassis frame 103b. The rocking mechanism 104 may include a main frame 104a fixed to the chassis frame 103b, a deck frame 104b to which the loading section 101 is fixed, a pin 104c that rotatably connects the deck frame 104b to the main frame 104a, and a dumping device 104d that rocks the deck frame 104b relative to the main frame 104a.

[0024] The main frame 104a is a rectangular frame-shaped member that is fixed to the chassis frame 103b. The main frame 104a is a rectangular frame-shaped member that is the same size as the chassis frame 103b and is fixed to the chassis frame 103b in a state where it is superimposed on the chassis frame 103b.

[0025] The deck frame 104b is a rectangular frame-shaped member to which the loading section 101 is fixed. The rear end of the main frame 104a is connected to the rear end of the deck frame 104b, and the connection between the main frame 104a and the deck frame 104b is a hinge structure. In this hinge structure, the pin 104c extends in the left-right direction D2. As a result, the deck frame 104b rotates around the pin 104c as an axis, and the loading section 101 fixed to the deck frame 104b moves between a reference position (position shown in Figure 1) and a dump position (not shown).

[0026] Furthermore, the rocking mechanism 104 may include support parts 104e positioned on the deck frame 104b, as shown in Figure 2. The rocking mechanism 104 may, for example, include four support parts 104e. The four support parts 104e are positioned at the four corners of the rectangular frame-shaped deck frame 104b.

[0027] The support section 104e supports the load cell 1. The support section 104e may include a pair of support blocks 104f arranged on the upper surface of the deck frame 104b at intervals from each other, as shown in Figure 2. The pair of support blocks 104f may be erected on a mounting plate 104h fixed to the deck frame 104b. In the deck frame 104b of this embodiment, the pair of support blocks 104f in the front support section 104e are arranged at an interval in the left-right direction D2, and the pair of support blocks 104f in the rear support section 104e are arranged at an interval in the front-rear direction D1. Figures 2 to 5 show the rear support section 104e, the load cell 1, and the transmission section 101e.

[0028] The four support sections 104e are positioned opposite each of the four corresponding transmission sections 101e. The pair of support blocks 104f are positioned to sandwich the corresponding transmission sections 101e from both sides.

[0029] Each of the pair of support blocks 104f is provided with through-holes 104g for load cells that penetrate in opposite directions. A load cell 1, which is inserted through the load cell through-hole 101f of the transmission section 101e, is inserted through each of the pair of load cell through-holes 104g.

[0030] The vehicle section 102 is configured to mount the loading section 101 by connecting the deck frame 104b and the sub-deck frame 101b such that the deck frame 104b and the sub-deck frame 101b of the loading section 101 overlap. At this time, a gap of vertical D3 is formed between the deck frame 104b and the sub-deck frame 101b so that the weight of the loading section 101 is transmitted to the load cell 1.

[0031] As described above, the loading section 101 and the vehicle section 102 are connected via load cells 1. Specifically, the two transmission sections 101e on the front side of the subdeck frame 101b and the two support sections 104e on the front side of the deck frame 104b are each connected via load cells 1, and the two transmission sections 101e on the rear side of the subdeck frame 101b and the two support sections 104e on the rear side of the deck frame 104b are each connected via load cells 1.

[0032] As shown in Figure 2, the load cell 1 is a cylindrical member extending in the front-rear direction D1, and the magnitude of the load can be measured by detecting the strain caused by the load (in this embodiment, the weight of the load) applied to the load cell 1.

[0033] As shown in Figures 3 and 4, the load cell 1 comprises a load cell body 2 extending in the front-rear direction D1 and subject to deformation when the weight of the load is applied, a bottomed cylindrical housing 3 adjacent to the front-rear end of the load cell body 2 in the front-rear direction D1, and a strain gauge 4 fixed to the load cell body 2 and for detecting the deformation of the load cell body 2.

[0034] Furthermore, the load cell 1 includes a circuit section 5 housed in a housing section 3, and a first wiring 6 extending from the circuit section 5 to the outside of the housing section 3. A cable 107 extending from the battery 105 and the indicator 106 is connected to this first wiring 6 (see Figure 7). In addition, the load cell 1 includes a second wiring 7 connecting the strain gauge 4 and the circuit section 5.

[0035] The load cell body 2 is a substantially cylindrical member made of metal and having a central axis along the front-rear direction D1. The load cell body 2 may include a plurality of small-diameter portions 21 arranged at intervals in the front-rear direction D1, a plurality of large-diameter portions 22 arranged at intervals in the front-rear direction D1, and a connecting portion 23 arranged at one end in the front-rear direction D1. The small-diameter portions 21 are arranged between two large-diameter portions 22. For example, the load cell body 2 may include two small-diameter portions 21 and three large-diameter portions 22.

[0036] Each large-diameter section 22 has an outer diameter corresponding to the inner diameter of the load cell through holes 101f and 104g (see Figure 2). On the other hand, the small-diameter sections 21 and connecting sections 23 have smaller diameters than the large-diameter sections 22. Furthermore, each small-diameter section 21 and connecting section 23 has an outer diameter smaller than the inner diameter of each load cell through hole 101f and 104g.

[0037] A locking groove 23a is formed on the side surface of the connecting portion 23, into which a plate-shaped locking piece 104i (see Figure 2) is locked. The locking piece 104i is fixed to the support block 104f while locked in the locking groove 23a. This prevents rotation and displacement of the load cell 1.

[0038] Furthermore, the load cell body 2 includes a strain gauge chamber 24 in which the strain gauge 4 is housed. The strain gauge 4 is adhesively fixed to the strain gauge chamber 24. The strain gauge chamber 24 is a hole that is recessed radially in the small diameter portion 21. The strain gauge chamber 24 is recessed in the small diameter portion 21, for example, in the left-right direction D2. In the load cell body 2 of this embodiment, a pair of strain gauge chambers 24 are arranged opposite each other in the left-right direction D2 of one small diameter portion 21. The inside of the strain gauge chamber 24 may be subjected to potting, which will be described later.

[0039] Furthermore, the load cell body 2 may have a counterbore 24a that is radially recessed around the entire circumference of the opening of the strain gauge chamber 24, as shown in Figure 4. In Figures 3 and 4, each strain gauge chamber 24 is shown with an opening facing outwards, but in reality, the opening is closed by a lid (not shown), and this lid is placed in the counterbore 24a.

[0040] Furthermore, the load cell body 2 may include a wiring arrangement section 25 extending from the strain gauge chamber 24 to the housing section 3. The wiring arrangement section 25 is a hole in which the second wiring 7 connecting the strain gauge 4 and the circuit section 5 is arranged. The wiring arrangement section 25 is a hole extending in the front-rear direction D1 of the load cell body 2, and connects adjacent strain gauge chambers 24 in the front-rear direction D1, or the strain gauge chamber 24 to the inside of the housing section 3.

[0041] The housing portion 3 is positioned adjacent to the front-rear end D1 of the load cell body 2. Specifically, the housing portion 3 is positioned adjacent to the connection portion 23 of the load cell body 2. The housing portion 3 is a bottomed cylindrical member positioned coaxially with the load cell body 2 and having an opening 3a. The housing portion 3 may include a cylindrical portion 3b, a bottom portion 3c that closes one end of the cylindrical portion 3b, and a notch 3d formed in the cylindrical portion 3b from a part of the opening 3a toward the bottom portion 3c.

[0042] The cylindrical portion 3b is, for example, cylindrical. The bottom portion 3c is, for example, disc-shaped. The bottom portion 3c has a through hole formed continuously with the wiring arrangement portion 25. The notch 3d is, for example, a rectangular notch (see Figure 6).

[0043] The storage section 3 may have insertion holes 3f formed in the bottom 3c. The insertion holes 3f are recesses in the bottom 3c that are recessed in the front-rear direction D1. The storage section 3 may have, for example, two insertion holes 3f.

[0044] Furthermore, the housing section 3 may be equipped with an earth terminal 3g provided at the bottom 3c. The earth terminal 3g is, for example, screwed to the bottom 3c.

[0045] The second wiring 7 connects the strain gauge 4 and the circuit section 5 through the wiring arrangement section 25. The second wiring 7 includes an input line 71 for inputting (applying) a predetermined voltage (applied voltage) output from the circuit section 5 to the strain gauge 4, and an output line 72 for transmitting the voltage output from the strain gauge 4 to the circuit section 5 (see Figure 8).

[0046] The length of each second wire 7 may be greater than or equal to the distance from the strain gauge 4 to the opening 3a of the housing 3. This allows for extra length in the second wires 7, making it easier for the worker to perform connection work (soldering, etc.) between the second wires 7 and the circuit section 5 outside the housing 3.

[0047] Each strain gauge 4 detects the resistance change caused by its expansion and contraction in conjunction with the load cell body 2, converts it into a voltage change, and outputs it. Specifically, when a predetermined voltage is applied to the strain gauge 4, it expands and contracts in conjunction with the load cell body 2, causing the voltage output from the strain gauge 4 to change. The voltage output from the strain gauge 4 is an analog signal.

[0048] As shown in Figures 3 and 4, the circuit section 5 may include a first substrate 51 and a second substrate 52 fixed on top of the first substrate 51. The first substrate 51 and the second substrate 52 are fixed in parallel. The first substrate 51 and the second substrate 52 are arranged along the front-to-back direction D1. That is, the first substrate 51 and the second substrate 52 are arranged along a direction perpendicular to the bottom 3c of the housing section 3. This makes it easy to house the first substrate 51 and the second substrate 52 into the housing section 3 through the opening 3a. It also makes it easy to remove the substrates 51 and 52 from the housing section 3 through the opening 3a. Furthermore, it makes it easy to check the condition of the substrates 51 and 52 from outside the housing section 3 through the opening 3a.

[0049] As shown in Figure 5, the first substrate 51 and the second substrate 52 are arranged such that, when viewed in the direction of the central axis of the housing 3 (in this embodiment, the front-to-back direction D1), the direction D4 perpendicular to the surface of the first substrate 51 and the second substrate 52 is inclined with respect to the direction D5 perpendicular to the outer surface of the cylindrical portion 3b where the notch 3d is formed (in this embodiment, the radial direction of the cylindrical portion 3b). Note that inclination of direction D4 with respect to direction D5 means that direction D4 is not parallel to direction D5, and also includes the case where direction D4 is perpendicular to direction D5. As a result, even when the first wiring 6 is brought out of the housing 3 in a slack state within the housing 3, the load on the first wiring 6 can be reduced compared to when the direction D4 perpendicular to the surface of the first substrate 51 and the second substrate 52 is parallel to the direction D5 perpendicular to the outer surface of the cylindrical portion 3b where the notch 3d is formed. The reason for leaving the first wire 6 slack inside the housing 3 and bringing it out of the housing 3 is that if the first wire 6 were left straight and not slack inside the housing 3, a pulling force would be directly applied to the circuit section 5 and the soldered part of the first wire 6 when the first wire 6 is pulled. By leaving the first wire 6 slack, this pulling force can be mitigated.

[0050] The first substrate 51 may have a projection 51a, as shown in Figure 6. The projection 51a is a convex portion that protrudes laterally from the edge of the first substrate 51. For example, the first substrate 51 has a projection 51a that protrudes in the front-rear direction D1 from the edge.

[0051] The first substrate 51 is provided with, for example, two protrusions 51a. The distance between the two protrusions 51a is the same as the distance between the two insertion holes 3f of the housing 3. Also, the protrusions 51a are smaller than the insertion holes 3f and can be inserted into the insertion holes 3f. As a result, the two protrusions 51a can be inserted into the two insertion holes 3f simultaneously. The first substrate 51 is fixed to the bottom 3c of the housing 3 by the insertion of the two protrusions 51a into the insertion holes 3f.

[0052] As shown in Figures 3 and 4, the second substrate 52 is smaller than the first substrate 51. Furthermore, the first substrate 51 and the second substrate 52 are positioned so that their ends on the opening 3a side coincide in the front-to-back direction D1. This creates a stepped portion 53 between the overlapping first substrate 51 and the second substrate 52. The stepped portion 53 is on the surface of the first substrate 51 facing the second substrate 52 and is located on the side of the second substrate 52. A portion of the second wiring 7 may be housed in this stepped portion 53. Note that a portion of the second wiring 7 may be housed in the stepped portion 53 in a coiled state. This allows a portion of the second wiring 7 to be housed in the remaining space of the circuit section 5 (in this embodiment, the stepped portion 53), eliminating the need to provide separate space for the second wiring 7 and thus saving space.

[0053] As shown in Figure 5, the circuit section 5 may include an earth wire 5g extending from the second board 52. The earth wire 5g is connected to the second board 52, for example, via terminal 5h.

[0054] The first substrate 51 and the second substrate 52 may be fixed in the housing section 3 by potting. Potting is a processing method in which the first substrate 51 and the second substrate 52 are placed in the housing section 3, resin is filled into the housing section 3, and the resin is allowed to solidify to fix the first substrate 51 and the second substrate 52. This allows the first substrate 51 and the second substrate 52 to be removed by scraping out the resin and then repositioned in the housing section 3, even if they are incorrectly fixed in the wrong position.

[0055] As shown in Figure 4, the load cell 1 may include a lid 31 that is detachably provided on the opening 3a of the housing 3, and a fixing member 32 that fixes the lid 31 to the opening 3a. By making the lid 31 detachable from the opening 3a, the first substrate 51 and the second substrate 52 can be easily removed. In addition, the lid 31 can suppress the lifting of the first substrate 51 and the second substrate 52, and can also suppress leakage of the resin during the potting process.

[0056] The fixing member 32 may be a snap ring, for example, as in this embodiment. In this case, a ring groove 3e into which the snap ring is inserted is formed on the inner circumferential surface of the cylindrical portion 3b near the opening 3a of the housing portion 3, as shown in Figures 3 and 4.

[0057] As shown in Figure 8, the circuit unit 5 includes an application unit 5a that applies a predetermined voltage to the strain gauge 4, and a calculation unit 5b that derives the weight applied to the load cell body 2 from the voltage output from the strain gauge 4 and outputs the derived weight as a weight signal.

[0058] The voltage application unit 5a is provided, for example, on the first substrate 51. The voltage application unit 5a applies a voltage to each strain gauge 4 and also applies a voltage to each calculation unit 5b.

[0059] The calculation unit 5b is provided, for example, on the second substrate 52. The second substrate 52 may further include an input unit 5c to which the voltage output from each strain gauge 4 is input, a memory unit 5d for storing the calculation results from the calculation unit 5b, a temperature sensor 5e for detecting the ambient temperature, and an output unit 5f for outputting the weight signal output from the calculation unit 5b to the outside.

[0060] The calculation unit 5b derives the weight applied to the load cell body 2 based on the changes in voltage output from each of the four strain gauges 4, and outputs the derived result as a weight signal. The calculation unit 5b can also correct the derived weight based on the ambient temperature detected by the temperature sensor 5e.

[0061] The memory section 5d is non-volatile memory.

[0062] The output unit 5f outputs the weight derived by the calculation unit 5b to the indicator 106, etc. The output unit 5f converts the weight signal output from the calculation unit 5b into a digital signal and outputs it. The output unit 5f communicates with the indicator 106, etc., for example, via CAN (Controller Area Network).

[0063] The first wiring 6 is a wire that extends from the circuit section 5 (specifically, the application section 5a of the first substrate 51 and the output section 5f of the second substrate 52) to the outside of the housing section 3, and the circuit section 5 is connected to the battery 105 and the indicator 106 by connecting the cable wire 107 (see Figure 7). As shown in Figures 3 and 4, the first wiring 6 extends to the outside of the housing section 3 by passing through the notch 3d of the housing section 3. This makes it easier for the worker to perform the connection work (soldering, etc.) between the first wiring 6 and the circuit section 5 outside of the housing section 3, and then house the circuit section 5 inside the housing section 3 with the first wiring 6 connected. As shown in Figure 4, the first wiring 6 extends to the outside of the housing section 3 by passing through the notch 3d in a direction perpendicular to the strain gauge 4 (in this embodiment, the left-right direction D2).

[0064] The battery 105 supplies power to each load cell 1 (specifically, the circuit unit 5) and the indicator 106 via the cable wire 107.

[0065] The indicator 106 is located in the driver's cab 103a and displays the weight of the load placed on the loading section 101 based on the weight signals output from each load cell 1 (circuit section 5). Furthermore, the indicator 106 may also display the weight applied to each load cell 1, the center of gravity of the load (loading section 101) determined based on the weight applied to each load cell 1, and the like.

[0066] As described above, the load cell 1, as in this embodiment, comprises a load cell body 2 that extends in a predetermined direction (in this embodiment, the front-rear direction) D1 and is subjected to deformation when a load is applied in a direction perpendicular to the predetermined direction D1 (in this embodiment, the up-down direction) D3; a bottomed cylindrical housing portion 3 adjacent to the end of the load cell body 2 in the predetermined direction D1 and having an opening 3a; and substrates (in this embodiment, a first substrate and a second substrate) 51, 52 housed in the housing portion 3. Preferably, the housing portion 3 comprises a cylindrical portion 3b and a bottom portion 3c that closes one end of the cylindrical portion 3b, and either the substrates 51, 52 or the bottom portion 3c (in this embodiment, the first substrate 51) is provided with a projection 51a, and the other of the substrates 51, 52 or the bottom portion 3c (in this embodiment, the bottom portion 3c) is provided with an insertion hole 3f, and the substrates 51, 52 are fixed to the bottom portion 3c by the projection 51a being inserted into the insertion hole 3f.

[0067] With this configuration, the housing section 3, which houses the substrates 51 and 52, is positioned adjacent to the load cell body 2, to which the strain gauge 4 is fixed. This allows the substrates 51 and 52 to be positioned close to the strain gauge 4. Furthermore, since the substrates 51 and 52 can be fixed to the housing section 3 by inserting the projection 51a into the insertion hole 3f, it is easy to align the substrates 51 and 52 with respect to the housing section 3, and the substrates 51 and 52 can be easily positioned.

[0068] Furthermore, in the load cell 1, it is preferable that the housing portion 3 is provided with an earth terminal 3g on the bottom portion 3c, and the earth wire 5g extending from the substrates 51 and 52 is connected to the earth terminal 3g, as in this embodiment.

[0069] With this configuration, the ground wire 5g extending from the circuit section 5 (boards 51, 52) can be shortened. Furthermore, this configuration makes wiring work easier. In contrast, conventionally, the ground wire extending from the circuit section 5 was connected to the chassis frame 103b, which required the ground wire to be long.

[0070] Furthermore, the weighing vehicle 100 is preferably configured as in this embodiment, comprising a loading section 101 capable of loading cargo, a vehicle section 102 on which the loading section 101 is mounted, and a load cell 1 positioned between the loading section 101 and the vehicle section 102.

[0071] With this configuration, substrates 51 and 52 can be easily placed near the strain gauge 4.

[0072] It should be noted that the load cell 1 and the vehicle with weighing function 100 are not limited to the configuration of the embodiment described above, nor are they limited to the effects described above. Furthermore, it goes without saying that the load cell 1 and the vehicle with weighing function 100 can be modified in various ways without departing from the spirit of the present invention. For example, one or more of the configurations and methods described below may be arbitrarily selected and adopted in the configurations and methods of the embodiment described above.

[0073] (A) In the load cell 1 according to the above embodiment, the housing 3 is provided with an earth terminal 3g at its bottom 3c, and the earth wires 5g extending from the substrates 51 and 52 are connected to the earth terminal 3g. However, the load cell 1 is not limited to this configuration.

[0074] For example, as shown in Figure 9, the bottom portion 3c may have a projection 3h made of metal, and the substrates 51 and 52 may have insertion holes 51b. The substrates 51 and 52 may be fixed to the bottom portion 3c by inserting the projection 3h into the insertion holes 51b. This allows the substrates 51 and 52 to be grounded by inserting the projection 3h into the insertion holes 51b. As a result, it is easier to align the substrates 51 and 52 with respect to the housing portion 3, and there is no need to provide a separate ground wire, thus reducing the number of components.

[0075] (B) In the load cell 1 according to the above embodiment, the substrates 51 and 52 are provided with two protrusions 51a, and the bottom 3c of the housing 3 is provided with two insertion holes 3f. However, the load cell 1 is not limited to this configuration. The substrates 51 and 52 may be provided with three or more protrusions 51a, and the bottom 3c of the housing 3 may be provided with three or more insertion holes 3f. Alternatively, the substrates 51 and 52 may be provided with one protrusion 51a, and the bottom 3c of the housing 3 may be provided with one insertion hole 3f. Alternatively, the bottom 3c of the housing section 3 may have a projection, and the substrates 51 and 52 may have insertion holes, with the projection on the bottom 3c of the housing section 3 being inserted into the insertion holes of the substrates 51 and 52. Furthermore, the substrates 51 and 52 and the bottom 3c of the housing section 3 may each have a projection and an insertion hole, with the projections of the substrates 51 and 52 being inserted into the insertion holes of the bottom 3c of the housing section 3, and the projection on the bottom 3c of the housing section 3 being inserted into the insertion holes of the substrates 51 and 52.

[0076] (C) In addition, in the load cell 1 according to the above embodiment, the substrates 51 and 52 comprise a first substrate 51 and a second substrate 52 which is smaller than the first substrate 51 and is fixed on top of the first substrate 51, and a part of the second wiring 7 is housed in a stepped portion 53 formed by the stacked first substrate 51 and second substrate 52. However, the load cell 1 is not limited to this configuration. For example, the first substrate 51 and the second substrate 52 may be the same size, or the second substrate 52 may be larger than the first substrate 51.

[0077] (D) In ​​addition, in the load cell 1 according to the above embodiment, the substrates 51 and 52 are arranged in a direction perpendicular to the bottom 3c of the housing 3. However, the load cell 1 is not limited to this configuration. For example, the substrates 51 and 52 may be arranged along the bottom 3c of the housing 3.

[0078] (E) In addition, in the load cell 1 according to the above embodiment, when viewed in the direction of the central axis of the housing 3, the direction D4 perpendicular to the plate surface of the substrates 51 and 52 is inclined with respect to the direction D5 perpendicular to the outer surface of the cylindrical portion 3b in the portion where the notch 3d is formed. However, the load cell 1 is not limited to this configuration. For example, when viewed in the direction of the central axis of the housing 3, the direction D4 perpendicular to the plate surface of the substrates 51 and 52 is parallel to the direction D5 perpendicular to the outer surface of the cylindrical portion 3b in the portion where the notch 3d is formed.

[0079] (F) In the load cell 1 according to the above embodiment, the substrates 51 and 52 are fixed within the housing 3 by potting. However, the load cell 1 is not limited to this configuration. For example, the substrates 51 and 52 may be fixed within the housing 3 by adhesive.

[0080] (G) Furthermore, the load cell 1 according to the above embodiment is configured to include a lid 31 that is detachably provided on the opening 3a of the housing 3, and a snap ring 32 that fixes the lid 31 to the opening 3a. However, the load cell 1 is not limited to this configuration. For example, the fixing member 32 that fixes the lid 31 to the opening 3a may be a bolt, a clip, or the like.

[0081] (H) In addition, in the load cell 1 according to the above embodiment, the housing section 3 is arranged coaxially with the load cell body 2. However, the load cell 1 is not limited to this configuration. The housing section 3 may be arranged such that its central axis intersects (for example, perpendicular to) the central axis of the load cell body 2.

[0082] (I) In the load cell 1 according to the above embodiment, the circuit section 5 is configured to include two substrates (a first substrate 51 and a second substrate 52). However, the load cell 1 is not limited to this configuration. The circuit section 5 may include one substrate, or it may include three or more substrates.

[0083] (J) In addition, in the load cell 1 according to the above embodiment, the first substrate 51 and the second substrate 52 are arranged in a stacked state. However, the load cell 1 is not limited to this configuration. The first substrate 51 and the second substrate 52 may be arranged separately.

[0084] (K) If the opening in the strain gauge chamber 24 is closed by a lid, potting may not be performed. Conversely, if potting is performed inside the strain gauge chamber 24, the lid may be omitted.

[0085] (L) In the load cell 1 according to the above embodiment, the load cell body 2 extends in the front-rear direction D1. However, the load cell 1 is not limited to this configuration. The load cell body 2 may also extend in the left-right direction D2, for example. Alternatively, the load cell body 2 may extend in a horizontal direction other than the front-rear direction D1 and the left-right direction D2, for example.

[0086] (M) In addition, the weighing vehicle 100 of the above embodiment is configured as a dump truck. However, the weighing vehicle 100 is not limited to this configuration. The weighing vehicle 100 may be a garbage truck, a tank truck, a freight truck, a mixer truck, a powder and granular material transport vehicle, a cargo bed or tailgate lift of a vehicle with a tailgate lift, a container transport vehicle, a vehicle with a detachable body, a washing and suction vehicle, etc. [Explanation of symbols]

[0087] 1...Load cell, 2...Load cell body, 3...Housing section, 3a...Opening, 3b...Cylindrical section, 3c...Bottom section, 3d...Notch, 3e...Ring groove, 3f...Insertion hole, 3g...Ground terminal, 3h...Protrusion, 4...Strain gauge, 5...Circuit section, 5a...Application section, 5b...Calculation section, 5c...Input section, 5d...Memory section, 5e...Temperature sensor, 5f...Output section, 5g...Ground wire, 5h...Terminal, 6...First wiring, 7...Second wiring, 21...Small diameter section, 22...Large diameter section, 23...Connection section, 23a...Locking groove, 24...Strain gauge chamber, 24a...Counterbore section, 25...Wiring arrangement section, 31...Lid, 32...Snap ring (fixing member), 51...First circuit board, 51a...Protrusion, 51b...Insertion hole, 52...Second circuit board, 53...Stepped section, 71...Input wire, 7 2…Output line, 100…Vehicle with weighing function, 101…Loading section, 101a…Cargo box, 101b…Subdeck frame, 101c…Cargo box body, 101d…Tailgate, 101e…Transmission section, 101f…Through hole for load cell, 102…Vehicle section, 103…Vehicle body, 103a…Driver's cab, 103b…Chassis frame, 104…Oscillating mechanism section, 104a…Main frame, 104b…Deck frame, 104c…Pin, 104d…Dumping device, 104e…Support section, 104f…Support block, 104g…Through hole for load cell, 104h…Mounting plate, 104i…Locking piece, 105…Battery, 106…Indicator, 107…Cable wire, D1…Front-rear direction, D2…Left-right direction, D3…Up-down direction

Claims

1. A load cell body extending in a predetermined direction, which is subjected to deformation when a load is applied in a direction perpendicular to the predetermined direction, A bottomed cylindrical housing portion having an opening is adjacent to the end of the load cell body in the predetermined direction, The facility comprises a substrate housed in the aforementioned housing section, The housing comprises a cylindrical portion and a bottom portion that closes one end of the cylindrical portion. A load cell in which either the substrate or the bottom portion is provided with a projection, and the other of the substrate or the bottom portion is provided with an insertion hole, and the substrate is fixed to the bottom portion by the projection being inserted into the insertion hole.

2. The housing section is equipped with an earth terminal located at its bottom. The load cell according to claim 1, wherein the ground wire extending from the substrate is connected to the ground terminal.

3. The load cell according to claim 1, wherein the bottom portion is provided with the projection formed of metal, and the substrate is provided with the insertion hole.

4. A loading section capable of loading cargo, A vehicle section on which the aforementioned loading section is mounted, A vehicle with a weighing function, comprising a load cell according to any one of claims 1 to 3, disposed between the loading section and the vehicle section.

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