JP5649900B2 - Weight weighing device - Google Patents

Description

  The present invention relates to a weight weighing apparatus.

  A weight weighing device in which a plurality of load cells are interposed between a loading portion on which a weighing object is loaded and a base portion, and is loaded with a cylindrical shaft-shaped pin type load cell with an axis extending in a horizontal direction. A combination of a metal fitting on the part side and a metal fitting on the base side is known. Since this structure can suppress the dimension in the height direction, it is also used as an on-vehicle weight weighing device in a vehicle such as a garbage truck (see Patent Documents 1 to 3).

  The shaft-shaped elastic body (columnar shape) of the shaft-shaped pin load cell and the holding hole (round hole) of the metal fitting are assembled with a clearance. When this gap is large, for example, for in-vehicle use, the impact load acts on the shaft-shaped elastic body of the shaft-shaped pin type load cell due to the vertical vibration of the loading platform and the cargo box when the vehicle is running, and there is a problem in terms of durability. . On the other hand, when this gap is small, the load between the load part and the base part due to the deformation of the load part (loading platform or cargo box) due to the weight of the load, the twist of the base part (vehicle body), the difference in thermal expansion between the base part and the load part, etc. There is a problem that relative displacement cannot be absorbed, and a large lateral load acts on the shaft-shaped elastic body of the shaft-shaped pin type load cell, resulting in a large measurement error.

JP 2004-299847 A JP 2007-139511 A JP 2009-35426 A

  In a weight weighing device that measures the weight of a weighing object with a plurality of shaft-shaped pin type load cells arranged in a posture in which the axis extends in the horizontal direction, loading is performed while ensuring durability in an operating environment in which vertical vibrations act. It is an object to improve the measurement accuracy by absorbing the relative displacement between the base and the base.

The present invention provides a plurality of weighing units each including a shaft-shaped pin type load cell that is interposed between a loading unit on which a weighing object is loaded and a base that supports the loading unit, and that has an axial line extending in a horizontal direction. Each weighing unit includes a mounting base side metal fitting fixed to the stacking part and a base side metal fitting fixed to the base part, and both end sides of the shaft-shaped pin type load cell are the loading parts. Supported by a hole wall of a holding hole provided in one of the side metal fitting and the base side metal fitting, and the central side of the shaft-shaped pin type load cell is provided on the other of the stacking part side metal fitting and the base side metal fitting. Supported by the hole wall of the holding hole , and in at least one of the plurality of measuring parts, the holding hole of at least one of the stacking part side metal fitting and the base part side metal fitting is a long hole , this being the rest of the holding hole and round hole Characterized, to provide a weighing device.

  For example, the measuring device includes a pair of measuring units arranged so that the axes of the axial pin type load cell extend in parallel with each other and are aligned in a horizontal direction perpendicular to the axis, On the other hand, at least one of the holding portion side metal fitting and the base side metal fitting is the elongated hole.

  Specifically, the holding hole, which is the elongated hole, includes a linear lower hole wall that extends perpendicularly to the axis of the axial pin type load cell and extends in the horizontal direction, and the lower hole wall. An upper hole wall located above, and a front hole wall and a rear hole wall that connect both ends of the lower hole wall and the upper hole wall, respectively.

  More specifically, the length of the lower and upper hole walls is not less than 0.04 times and not more than 0.2 times the diameter of the axial pin type load cell, and the axial pin type load cell and the upper side or The gap between the upper hole wall is 0.001 to 0.02 times the diameter of the axial pin type load cell.

  In the weight weighing device of the present invention, in at least one of the plurality of weighing units interposed between the loading unit and the base, the shaft-shaped pin type load cell is held for at least one of the loading unit side metal fitting and the base side metal fitting. The holding hole is a long hole. Therefore, the measurement accuracy can be improved by absorbing the relative displacement between the loading portion and the base portion while ensuring the durability under the usage environment in which the vertical vibration acts. Specifically, since a sufficient gap is secured between the front hole wall and the rear hole wall of the elongated hole and the shaft-shaped pin type load cell, deformation of the loading portion, twisting of the base portion, The relative displacement between the loading part and the base part due to the difference in thermal expansion is absorbed, and a large lateral load does not act on the shaft-shaped pin type load cell. As a result, the weighing accuracy is improved. In addition, the gap between the shaft-shaped pin type load cell supported by the long hole and the upper hole wall or the lower hole wall of the long hole is set to the minimum necessary for assembly. Excessive impact load due to the vertical vibration of the loading part does not act on the shaft-shaped pin type load cell, and durability can be secured.

1 is a schematic side view of a vehicle including an on-vehicle weight weighing device according to an embodiment of the present invention. 1 is a schematic plan view of a vehicle including an on-vehicle weight weighing device according to an embodiment of the present invention. The typical perspective view which shows arrangement | positioning of a measurement unit. The typical side view of a vehicle body, a loading platform, and a measurement unit. Sectional drawing in the VV line | wire of FIG. The typical perspective view of a measuring unit (a body side metal fitting is a round hole and a loading platform side metal fitting is a long hole). Schematic side view of the weighing unit (the body-side bracket is a long hole and the loading platform bracket is a round hole). A typical side view of a measuring unit (both body side metal fittings and cargo bed side metal fittings are long holes). The typical perspective view of a measuring unit (both a vehicle body side metal fitting and a loading platform side metal fitting are round holes). The typical partial expanded side view which shows the relationship between an axial pin type load cell and a long hole. The side view for demonstrating a lateral load. The side view of an axial pin type load cell. The partial expanded sectional view of the XI-XI line of FIG. The typical perspective view which shows arrangement | positioning of the measurement unit in a modification. The typical perspective view which shows arrangement | positioning of the measurement unit in another modification.

  FIG.1 and FIG.2 shows the vehicle 2 provided with the vehicle-mounted weight weighing apparatus 1 to which this invention is applied. On the vehicle body (base) 3 of the vehicle 2, a loading platform (loading portion) 4 on which a weighing object is loaded is disposed (a loading box 5 may be disposed on the loading platform 4 or instead of the loading platform 4). . The type of the vehicle 2 is, for example, a garbage truck, sludge suction or the like, but is not particularly limited. Further, a dump mechanism may be provided.

3 to 5 together, a total of four measuring units (measuring units) 7F and 7R are interposed between the loading platform 4 and the vehicle body 3 that supports the loading platform 4 in this embodiment. . Specifically, two weighing units 7F and 7F are arranged on the front side of the vehicle body 3 so as to be arranged in a line in the vehicle width direction (left and right direction), and 1 on the rear side of the vehicle body 3 in the vehicle width direction. Two weighing units 7R and 7R are arranged in a line.

  Each of the weighing units 7F and 7R includes a vehicle body side metal fitting 11, a cargo bed side metal fitting 12, and an axial pin type load cell 13.

  As shown in FIGS. 6A to 7, the vehicle body side metal fitting 11 includes a seat portion 11a fixed to the upper surface of the vehicle body 3, and a pair of plate-like support portions 11b extending in parallel upward from both ends of the seat portion 11a. 11b. Each support part 11b is provided with a holding hole 11c so as to penetrate in the thickness direction. The loading platform side metal 12 has a plate shape whose upper portion is fixed to the lower surface of the loading platform 4, and is provided with a holding hole 12 a so as to penetrate in the thickness direction. The loading platform side metal fitting 12 is disposed between the pair of support portions 11 b and 11 b of the vehicle body side metal fitting 11. The generally cylindrical cylindrical elastic body 14 provided in the shaft-shaped pin type load cell 13 passes through the two holding holes 11c, 11c of the vehicle body side metal fitting 11 and the one holding hole 12a of the cargo bed side metal fitting 12. Has been placed. The shaft-like elastic body 14 of the shaft-shaped pin load cell 13 is held by the holding holes 11c and 11c and the holding hole 12a so that the axis γ extends in the horizontal direction and the vehicle width. Specifically, the shaft-shaped elastic body 14 of the shaft-shaped pin type load cell 13 is held near the both ends by the holding holes 11c and 11c of the vehicle body side metal fitting 11, and the vicinity of the center in the length direction (axis γ direction) is the loading platform. It is held by the holding hole 12 a of the side metal fitting 12.

  As long as it has a holding hole for holding the shaft-like elastic body of the shaft-shaped pin type load cell 13 in a posture in which the axis γ extends in the horizontal direction, the concrete of the vehicle body side metal fitting 11 and the cargo bed side metal fitting 12 of each weighing unit 7F, 7R The structure is not limited to that illustrated. For example, the seat 11a of the illustrated body side metal fitting 11 is fixed to the lower surface of the loading platform 4 and used as a loading platform side metal fitting, and the lower end side of the illustrated loading platform side metal fitting 12 is fixed to the upper surface of the vehicle body 3 as the vehicle body side metal fitting. May be used.

  Referring to FIGS. 10 and 11 together, the shaft-shaped elastic body 14 of the shaft-shaped pin type load cell 13 is provided with a pair of recesses 15A to 15D each having a circular cross section facing each other in the direction orthogonal to the axis γ. , 15B and between the recesses 15C, 15D are provided with strain-generating portions 16A, 16B having a relatively thin disk shape and a reduced cross-sectional area in a direction perpendicular to the axis γ. One of the strain generating portions 16A and 16B is located between one support portion 11b of the vehicle body side metal fitting 11 and the loading platform side metal fitting 12, and the other is between the other support portion 11b of the vehicle body side metal fitting 11 and the loading platform side metal fitting 12. Is located. The strain generating portions 16A and 16B are designed in such a shape that an appropriate shear strain is generated by a load Fv (corresponding to the weight of the weighing object) applied from the loading platform side metal fitting 12 and the vehicle body side metal fitting 11. Strain gauges 17 are attached to both surfaces of the individual strain generating portions 16A and 16B. These strain gauges 17 constitute a Wheatstone bridge circuit so that an electrical signal proportional to the load Fv can be obtained. As long as the shaft-shaped elastic body 14 is cylindrical and the load acting from the loading platform side metal fitting 12 and the vehicle body side metal fitting 11 can be detected, the specific structure of the shaft-shaped pin type load cell 13 is not particularly limited.

  As shown most clearly in FIG. 3, the four weighing units 7F and 7R are all arranged such that the axis γ of the shaft-like elastic body 14 of the shaft-shaped pin type load cell 13 extends in the vehicle width direction (left-right direction). Has been. That is, the four weighing units 7F and 7R are arranged such that the axis γ of the shaft-shaped pin type load cell 13 extends in parallel with each other.

  Referring to FIGS. 3, 4, and 6 </ b> A, in the weighing unit 7 </ b> F on the front side, the holding hole 11 c of the vehicle body side metal fitting 11 is a round hole 20, while the holding hole 12 a of the cargo bed side metal fitting 12 is a long hole 21. Yes. The diameter of the holding hole 11c (round hole 20) is slightly larger than the diameter D (see FIG. 8) of the shaft-shaped elastic body 14 so that the shaft-shaped elastic body 14 of the shaft-shaped pin type load cell 13 can be inserted. It is set.

  Referring to FIG. 8, the holding hole 12 a (the long hole 21) formed in the loading platform side metal 12 is orthogonal to the axis γ of the shaft-shaped elastic body 14 of the shaft-shaped pin type load cell 13 and extends in the horizontal direction. A straight lower hole wall 22 and a straight upper hole wall 23 positioned above the lower hole wall 22 and extending in the horizontal direction in parallel with the lower hole wall 22 are provided. The holding hole 12a (the long hole 21) includes a semicircular arc-shaped front hole wall 24 and a rear hole wall 25 that connect both ends of the lower hole wall 22 and the upper hole wall 23, respectively.

  As shown most clearly in FIG. 8, the shaft-shaped elastic body 14 of the shaft-shaped pin type load cell 13 inserted through the holding hole 12 a (the long hole 21) supports the upper hole wall 23. The length α of the lower hole wall 22 and the upper hole wall 23 is set so that a sufficient horizontal clearance β is secured between the shaft-like elastic body 14 and the front and rear hole walls 24 and 25. Yes.

  For example, the length α of the lower hole wall 22 and the upper hole wall 23 is set in a range of 0.04 to 0.2 times the diameter D of the shaft-shaped elastic body 14 of the shaft-shaped pin type load cell 13. . The length α of the straight lower hole wall 22 and the upper hole wall 23 is larger than the assumed relative deflection of the load carrier 4 and thermal expansion, and relative displacement between the vehicle body side metal 11 and the load side metal 12 caused by twisting. Must be set. When the length α is shorter than the relative displacement, the relative displacement cannot be absorbed and a sufficient function cannot be exhibited. In addition, since the relative displacement may generally move to the plus side and the minus side, the center of the axial pin type load cell 13 is the center of the long hole 21, that is, the straight lower hole wall 22 having a length α. And the center of the upper hole wall 23 must be set. On the other hand, when the condition that the length α is larger than the relative displacement is satisfied but is not sufficiently large, it takes time to position the weighing units 7F and 7R during assembly, and the assembly work efficiency decreases. Generally, the diameter D of the axial pin type load cell 13 incorporated in a large structure is large, and the diameter D of the axial pin type load cell 13 is small for a small structure, and the length α is proportional to the size of the structure. Therefore, the ratio α / D of the length α to the diameter D is generally within a certain range. In consideration of functionality and assembly, the lower limit value of the ratio α / D is set to 0.04, for example. When the ratio α / D is increased, the assemblability is improved, but the bearing size is increased and the processing cost is increased. Therefore, the upper limit value of the ratio α / D is set to 0.2, for example.

  As described above, the shaft-like elastic body 14 supports the upper hole wall 23, and the vertical gap ε between the lower end of the shaft-like elastic body 14 and the lower hole wall 22 is the holding hole 12 a (the long hole 21. ) Is set as narrow as possible within a range in which the shaft-like elastic body 14 can be inserted. For example, the vertical gap ε is set in the range of 0.001 to 0.02 times the diameter D of the shaft-like elastic body 14 of the shaft-shaped pin type load cell 13. This vertical gap ε differs depending on the environment in which the weight weighing device is used, and is set to a small value when there is a vertical vibration or a load condition for lifting the loading portion (loading platform 4 in this embodiment), depending on the dynamic behavior of the loading portion. It is necessary to prevent impact loads. In a static use environment, it is preferable to set the vertical gap ε to be large in consideration of assembly. The ratio ε / D of the vertical gap ε to the diameter D of the axial pin type load cell 13 is generally within a certain range regardless of the size of the structure, and the ratio ε / D is similar to the ratio α / D described above. If it is too small, assembly becomes difficult, so the lower limit is set to 0.001, for example, and the upper limit is set to 0.02, for example, to suppress dynamic behavior.

  3, 4, and 7, in the rear weighing unit 7 </ b> R, the holding hole 11 c of the vehicle body side metal fitting 11 and the holding hole 12 a of the cargo bed side metal fitting 12 are both round holes 20. The hole diameters of the holding hole 11c and the holding hole 12a (round hole 20) are set slightly larger than the diameter D of the shaft-like elastic body 14 so that the shaft-like elastic body 14 of the shaft-like pin type load cell 13 can be inserted. doing.

  Referring to FIGS. 2 and 3, on the right side of the vehicle body 3, a front weighing unit 7 </ b> F and a rear weighing unit 7 </ b> R form a pair facing the vehicle body 3 in the front-rear direction. The unit 7F and the rear weighing unit 7R form a similar pair. Of the two weighing units 7F and 7R constituting each pair, in one (front side) weighing unit 7F, the holding hole 11c of the vehicle body side metal fitting 11 is a round hole 20, but the holding side metal fitting 12 is held. The hole 12a is a long hole 21, and the holding hole 11c of the vehicle body side metal fitting 11 and the holding hole 12a of the cargo bed side metal fitting 12 are both round holes 20 in the other (rear side) measuring unit 7R.

  The advantages of the on-vehicle weight weighing device 1 of the present embodiment having the above configuration will be described below.

  FIG. 9 shows an example in which the holding holes 11c and 12a of the vehicle body side metal fitting 11 and the cargo bed side metal fitting 12 are all round holes 20 in both the front and rear weighing units 7F and 7R. The loading platform 4 may bend due to the load F of the weighing object. In this case, the holding holes 12a of the loading platform side metal fittings 12a of the weighing units 7F and 7R on the front side and the rear side (the axial shape of the axial pin type load cell 13). Distance from the distance L to the distance L ′. On the other hand, the shaft-shaped elastic body 14 of the shaft-shaped pin type load cell 13 is also supported by the holding hole 11c of the vehicle body side metal fitting 11, and the holding hole 11c of the vehicle body side metal fitting 11 is measured on the front and rear weighing units 7F. , 7R does not change in distance. That is, due to the deflection of the loading platform 4 due to the load F of the weighing object, a relative displacement in the horizontal direction occurs between the vehicle body side metal fitting 11 (holding hole 11c) and the loading platform side metal fitting 12 (holding hole 12a). Such a relative displacement in the horizontal direction between the vehicle body side metal fitting 11 (holding hole 11c) and the cargo bed side metal fitting 12 (holding hole 12a) is caused by a difference in thermal expansion between the vehicle body 3 and the cargo bed 4 with respect to a temperature rise. It is also caused by the twist of the vehicle body 3. When the holding holes 11c and 12a are all round holes 20, and the gap between the holding holes 11c and 12a and the shaft-like elastic body 14 is small, the shaft-like elastic body 14 is against the relative displacement in the horizontal direction. Therefore, a large lateral load Fh acts on the axial elastic body 14 of the axial pin type load cell 13 in a direction perpendicular to the axis γ (a direction perpendicular to the axis). This lateral load Fh causes a measurement error.

  On the other hand, in the present embodiment, for the front weighing unit 7F, the holding hole 12a of the loading platform side metal 12 is the long hole 21, and the shaft-shaped elastic body 14 of the shaft-shaped pin type load cell 13 and the front and rear hole walls 24 are used. , 25, a sufficient horizontal clearance β is ensured, and the shaft-like elastic body 14 is in contact with the upper hole wall 23 of the elongated hole 21 and can slide in the horizontal direction. Therefore, the relative displacement in the horizontal direction between the vehicle body side metal fitting 11 (holding hole 11c) and the cargo bed side metal fitting 12 (holding hole 12a) due to the bending of the loading bed 4 or the like is the holding of the loading bed side metal fitting 12 of the measuring unit 7F. The axial elastic body 14 of the axial pin type load cell 13 is absorbed by moving in the horizontal direction in the hole 12a (long hole 21). In other words, the horizontal direction of the shaft-like elastic body 14 with respect to the relative displacement in the horizontal direction between the vehicle body side metal fitting 11 (holding hole 11c) and the cargo bed side metal fitting 12 (holding hole 12a) due to the deflection of the loading platform 4 or the like. Therefore, the lateral load Fh that causes a measurement error is greatly reduced. A lateral load Fh due to friction acts on the shaft-like elastic body 14 that slides in the horizontal direction in contact with the upper hole wall 23 of the long hole 21. This lateral load is a shaft-like elasticity as in the example of FIG. It is much smaller than the lateral load Fh when the horizontal movement of the body 14 is restricted.

  As described above, a sufficient horizontal clearance β is ensured between the front hole wall 24 and the rear hole wall 25 of the long hole 21 and the shaft-shaped elastic body 14 of the shaft-shaped pin type load cell 13. The relative displacement between the loading platform 4 and the vehicle body 3 due to the deformation of the vehicle body 3, the twisting of the vehicle body 3, the difference in thermal expansion between the vehicle body 3 and the loading platform 4, etc. is absorbed, and the large lateral load Fh does not act on the axial pin type load cell 13. As a result, the weighing accuracy is improved.

  As is clear from FIG. 9, the lateral load Fh acting on the axial pin type load cell 13 of the weighing units 7F, 7R paired in the front-rear direction (the direction orthogonal to the axis γ) of the vehicle body 3 is balanced as an internal force. It becomes a state. Therefore, rather than making the holding hole 12a a long hole 21 for both of the weighing units 7F and 7R paired in the front-rear direction, the holding hole 12a can be a long hole 21 for only one of the weighing units 7F and 7R. preferable.

  Next, the lateral load Fh acting on the shaft-like elastic body 14 that contacts the upper hole wall 23 of the elongated hole 21 and slides in the horizontal direction is expressed by the following equation by the law of friction. It is proportional to the normal force acting on the body 14.

  Since the loading platform 4 of the vehicle 2 such as a garbage collection vehicle generally has a center of gravity behind, when comparing the weighing units 7F and 7R paired in the front-rear direction, the shaft of the axial pin type load cell 13 provided in the weighing unit 7F on the front side is compared. The vertical force W acting on the elastic body 14 is small.

  Considering the above points, in the present embodiment, the holding hole 12a is made into the long hole 21 only in the front weighing unit 7F having a small vertical force W among the weighing units 7F and 7R paired in the front-rear direction, and the weighing accuracy is improved. It is further improved. Also, in the rear weighing unit 7R, both holding holes 11c and 12a are round holes 20, thereby restricting the movement of the loading platform 4 relative to the vehicle body 3 when the vehicle 2 is started, stopped or running. doing.

  In the present embodiment, as shown in FIG. 6A, only the holding hole 12 a of the loading platform side metal 12 is a long hole 21. However, if either one or both of the holding hole 12a of the carrier side metal fitting 12 and the holding hole 11c of the vehicle body side metal fitting 11 are long holes, the above-described vehicle body side metal fitting 11 (holding hole 11c) and the carrier side metal fitting 12 (holding hole) The effect of absorbing the relative displacement with respect to 12a) is obtained.

  For example, as shown in FIG. 6B, contrary to the present embodiment, the holding hole 11 c of the vehicle body side metal fitting 11 may be a long hole 21 and the holding hole 12 a of the cargo bed side metal fitting 12 may be a round hole 20.

  Further, as shown in FIG. 6C, both the holding hole 11c of the vehicle body side metal fitting 11 and the holding hole 12a of the cargo bed side metal fitting 12 may be long holes 21. In this case, the shaft-shaped elastic body 14 of the shaft-shaped pin type load cell 13 against the relative displacement in the horizontal direction between the vehicle body side metal fitting 11 (holding hole 11c) and the cargo bed side metal fitting 12 (holding hole 12a) It can be rotated. That is, the horizontal movement of the shaft-shaped elastic body 14 of the shaft-shaped pin type load cell 13 relative to the upper hole wall 23 of the long hole 21 is not sliding but rolling. Since the rolling friction force is considerably smaller than the sliding friction force (see the above formula), the lateral load Fh can be further reduced to further improve the measurement accuracy.

  A vertical gap ε between the lower end of the shaft-like elastic body 14 of the shaft-shaped pin type load cell 13 that supports the upper hole wall 23 of the long hole 21 and the lower hole wall 22 of the long hole 21 is necessary for assembly. Since it is set to the minimum, an excessive impact load due to the vertical vibration of the loading platform 4 on which the weighing object is loaded does not act on the shaft-shaped elastic body 14 of the shaft-shaped pin type load cell 13. As a result, durability can be secured.

  As described above, in the on-vehicle weight weighing device 1 according to the present embodiment, the loading platform side metal fitting 12 and the vehicle body side fitting 11 are provided in at least one of the plurality of weighing units 7F and 7R interposed between the loading platform 4 and the vehicle body 3. By making the holding holes 11c and 12a for holding the shaft-shaped pin type load cell 13 at least one of them into the long holes 21, the measurement accuracy is improved while ensuring durability against vertical vibration.

  12 and 13 show a modification of the present embodiment.

  The in-vehicle weight weighing device 1 of the modified example shown in FIG. 12 includes one weighing unit 7F on the front side of the vehicle body 3, and two (one row) weighing units 7R on the rear side. Among these three weighing units 7F and 7R, for one weighing unit 7F on the front side, the holding hole 12a of the loading platform side metal 12 is a long hole 21 and the holding hole 11c of the vehicle body side metal fitting 11 is a round hole 20. For the two weighing units 7 on the rear side, the holding holes 11c and 12a of the loading platform side metal fitting 12 and the vehicle body side metal fitting 11 are round holes 20.

  In another modification shown in FIG. 13, two (one row) weighing units 7F, 7F are provided on the front side of the vehicle body 3, and four (two rows) weighing units 7R, 7R, 7R ′, 7R ′. For the two weighing units 7F, 7F on the front side and the two weighing units 7R, 7R in the rear front row, the holding hole 12a of the loading platform side metal 12 is a long hole 21, and the holding hole 11c of the body side metal fitting 11 is a round hole. It is set to 20. As for the two weighing units 7R ′ and 7R ′ in the rear rear row, the holding holes 11c and 12a of the carrier side metal fitting 12 and the vehicle body side metal fitting 11 are round holes 20.

  12 and 13 also, one of the measuring unit pairs facing in the front-rear direction of the vehicle body 3 (perpendicular to the axis γ of the axial pin type load cell 13 and in the horizontal direction). Since at least one of the holding holes 12a and 11c of the loading platform side metal fitting 12 and the vehicle body side fitting 11 is a long hole 21, while ensuring durability by preventing impact load due to vertical vibration of the loading platform 4, as in the above-described embodiment, The measurement accuracy can be improved by absorbing the relative displacement between the loading platform 4 and the vehicle body 3.

  Although the present invention has been described by taking the on-vehicle weight weighing device as an example, the present invention is not limited to the on-vehicle weight weighing device, but can be applied to a weight weighing device for other purposes. For example, the present invention can also be applied to a weight measuring device for measuring the weight of a baggage at a baggage collection place or the like and a general stand.

DESCRIPTION OF SYMBOLS 1 In-vehicle weight measuring apparatus 2 Vehicle 3 Car body 4 Cargo bed 5 Cargo box 7F, 7R Weighing unit 11 Car body side metal fitting 11a Seat part 11b Support part 11c Holding hole 12 Cargo side metal fitting 12a Holding hole 13 Axial pin type load cell 14 Axis elastic body 15A to 15D Concave portion 16A, 16B Strain portion 17 Strain gauge 20 Round hole 21 Long hole 22 Lower hole wall 23 Upper hole wall 24 Front hole wall 25 Rear hole wall γ Axis D Diameter α Length β Horizontal gap ε Vertical Direction gap L, L 'distance

Claims (4)

A plurality of weighing units each including an axial pin type load cell that is interposed between a loading unit on which a weighing object is loaded and a base that supports the loading unit and whose axis extends in a horizontal direction,
Each of the weighing units includes a mounting base side metal fitting fixed to the loading part and a base side metal fitting fixed to the base part, and both end sides of the shaft-shaped pin type load cell are the loading part side metal fitting and the Supported by the hole wall of the holding hole provided in one of the base side metal fittings, and the central side of the shaft-shaped pin type load cell is the holding hole provided in the other of the stacking side metal fittings and the base side metal fittings Supported by the hole wall ,
In at least one of the plurality of measuring portions, at least one of the holding portion side metal fitting and the base side metal fitting is a long hole, and the remaining holding holes are round holes . A weight measuring device. The axis of the pin-shaped pin type load cell includes a pair of measuring portions arranged so as to extend in parallel with each other and aligned in a horizontal direction perpendicular to the axis;
The one of the measurement parts constituting the pair, wherein the holding hole of at least one of the stacking part side metal fitting and the base side metal fitting is the elongated hole. Weight weighing device.   The holding hole, which is the elongated hole, has a linear lower hole wall that is orthogonal to the axis of the axial pin type load cell and extends in the horizontal direction, and an upper side that is located above the lower hole wall. 3. The weight measuring device according to claim 1, further comprising a hole wall, and a front hole wall and a rear hole wall that connect both ends of the lower hole wall and the upper hole wall, respectively. . The length of the lower and upper hole walls is not less than 0.04 times and not more than 0.2 times the diameter of the axial pin type load cell,
The gap between the axial pin type load cell and the upper or upper hole wall is 0.001 to 0.02 times the diameter of the axial pin type load cell. 2. The weight measuring device according to 2.

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