JP6967914B2 - Load transducer - Google Patents

Description

The present invention relates to a load transducer, and more particularly to a load transducer for converting a load into an electrical signal.

Conventionally, in a weighing device such as a scale, a weighing device using a reverbal type load cell having a reverbal mechanism has been widely known. Such a weighing device has a load transducer for converting a load into an electric signal, and the load transducer has a metal block body used as a reverbal type strain generator. This block body has a hollow symmetrical shape (see, for example, Patent Document 1). Further, the reverbal type load cell is used not only for the measuring device as described above but also for detecting the tension of the wire in the wire saw used in the wire saw method. The wire saw method is a type of cutting method for objects, and is vibration-free, low-noise, and dust-free, with no restrictions on objects and their conditions, such as complex shapes such as reinforced concrete, underwater structures, narrow places, and high places. It is a construction method that can be cut in any direction because there are few machines that can be arranged according to the site conditions. The wire saw method is also used for processing semiconductor ingots and semiconductor wafers.

Japanese Unexamined Patent Publication No. 2001-083024

In recent years, the processing targets of such a wire saw method have expanded to small objects such as semiconductor ingots and semiconductor wafers, and the wire saw used in the wire saw method has also been miniaturized. Therefore, the reverbal type load transducer used for the wire saw is also required to be miniaturized.

With the miniaturization of the reverbal type load converter, the block body becomes thinner, and there is concern about the strength of the block body. In particular, the block body is damaged by the load applied to the block body due to bolting when fixing the block body. There was a risk of doing so. As described above, a structure capable of preventing the occurrence of breakage has been required for the block body of the reverbal type load transducer conventionally used in the wire saw method.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a load transducer capable of preventing damage due to overload even when the size is reduced.

In order to achieve the above object, the load converter according to the present invention includes a block body and a strain gauge attached to the block body, and the block body includes a fixing portion fixed to a support member and the above-mentioned fixed portion. A movable portion that faces the fixed portion and receives a load from the outside, extends between the fixed portion and the movable portion, and is provided between a pair of beam portions facing each other and the movable portion. Each of the pair of beam portions has a fixed portion side straining portion provided on the fixed portion side and a movable portion side raising portion provided on the movable portion side. It has a distorted portion, and the stopper portion is formed so that the stopper protruding portion extending from the fixed portion toward the movable portion side and the stopper protruding portion can be in contact with each other on the pair of beam portions. It has a pair of stopper contact portions, and the pair of stopper contact portions are provided between the fixed portion side straining portion and the movable portion side straining portion of the pair of beam portions. It is characterized by being.

In the load transducer according to one aspect of the present invention, the stopper portion has a stopper accommodating portion for accommodating the stopper protruding portion on the movable portion side, and the stopper accommodating portion is the pair of stopper contact portions. have.

In the load transducer according to one aspect of the present invention, a space is formed in the stopper accommodating portion on the movable portion side of the stopper protruding portion.

In the load transducer according to one aspect of the present invention, the pair of stopper contact portions can contact the tip portion of the stopper protrusion.

In the load transducer according to one aspect of the present invention, the stopper protrusion has a pair of stopper protrusion contact portions that face each other of the pair of stopper contact portions via a gap.

In the load transducer according to one aspect of the present invention, the fixed portion and the movable portion are disk-shaped flanges.

In the load transducer according to one aspect of the present invention, the stopper protrusion is located at a position closer to the fixed portion than the stopper protrusion contact portion in the extending direction of the stopper protrusion. It has a constricted part that is more constricted.

In the load transducer according to one aspect of the present invention, the movable portion is provided with a wire attachment portion to which a wire is attached.

According to the load transducer according to the present invention, damage due to overload can be prevented even when the size is reduced.

It is a front view which shows roughly the structure of the load transducer which concerns on embodiment of this invention. It is a perspective view which shows schematic structure of the load transducer which concerns on embodiment of this invention. It is a partially enlarged view of the stopper part in the load transducer which concerns on embodiment of this invention. It is sectional drawing which shows schematic the structure of the load transducer which concerns on embodiment of this invention in the use state attached to the wire saw. It is a partially enlarged view of the stopper part in the modification of the load converter which concerns on embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a front view schematically showing the configuration of the load transducer 1 according to the embodiment of the present invention, and FIG. 2 schematically shows the configuration of the load transducer 1 according to the embodiment of the present invention. It is a perspective view which shows. As shown in FIGS. 1 and 2, the load transducer 1 according to the embodiment of the present invention includes a block body 2 and a strain gauge 3 attached to the block body 2. The block body 2 has a fixed portion 20 fixed to the support member and a movable portion 30 facing the fixed portion 20 and receiving a load from the outside. Further, the block body 2 extends between the fixed portion 20 and the movable portion 30, and is provided between the pair of beam portions 40 and 50 facing each other and the pair of beam portions 40 and 50 to displace the movable portion 30. It has a stopper portion 60 for regulating. The pair of beam portions 40 and 50 each have a fixed portion side straining portion 41 and 51 provided on the fixed portion 20 side and a movable portion side straining portion 42 and 52 provided on the movable portion 30 side. ing. The stopper portion 60 is a pair of stoppers formed so that the stopper protrusion 70 extending from the fixed portion 20 toward the movable portion 30 side and the pair of beam portions 40 and 50 can be in contact with the stopper protrusion 70, respectively. It has contact portions 81 and 82. The pair of stopper contact portions 81 and 82 are provided between the fixed portion side straining portions 41 and 51 and the movable portion side straining portions 42 and 52 of the pair of beam portions 40 and 50. The load transducer 1 is used, for example, for detecting the tension of a wire in a wire saw used in a wire saw method. Hereinafter, for convenience of explanation, the upper side in FIG. 1 is referred to as the upper side, and the lower side in FIG. 1 is referred to as the lower side. Further, the vertical direction of the paper surface in FIG. 1 is the thickness direction, the left-right direction in FIG. 1 is the length direction, and the vertical direction in FIG. 1 is the width direction. Hereinafter, the configuration of the load converter 1 will be specifically described.

In the block body 2, the fixing portion 20 is, for example, a disk-shaped flange. In the block body 2, the movable portion 30 is, for example, a disk-shaped flange having the same or substantially the same diameter as the fixed portion 20. The fixed portion 20 has a facing surface 21 on the side facing the movable portion 30. The facing surface 21 is a flat surface or a substantially planar surface. Further, the movable portion 30 has a facing surface 31 on the side facing the fixed portion 20. The facing surface 31 is a plane or a substantially planar surface extending parallel to or substantially parallel to the facing surface 21. Further, as will be described later with reference to FIG. 4, the fixing portion 20 is formed with a plurality of bolt holes 22 for fixing the load converter 1 to the support member of the wire saw in which the load converter 1 is used. Further, the movable portion 30 is formed with a bolt hole 32 for fixing the wire mounting portion 90 for mounting the wire of the wire saw described later, and the bolt hole 32 penetrates the movable portion 30.

Further, in the block body 2, the upper beam portion 40, which is one of the pair of beam portions, and the lower beam portion 50, which is the other of the pair of beam portions, have a shape symmetrical or substantially symmetrical to each other. The upper beam portion 40 is a plate-shaped portion extending between the fixed portion 20 and the movable portion 30, and is orthogonal to or substantially perpendicular to the facing surface 21 of the fixed portion 20 and the facing surface 31 of the movable portion 30. It extends orthogonally.

Further, the upper fixed portion side straining portion 41 as the fixed portion side straining portion of the upper beam portion 40 and the upper movable portion side straining portion 42 as the movable portion side straining portion of the upper beam portion 40 are shown in FIG. As shown, they extend parallel to or substantially parallel to each other in the thickness direction, and extend along the facing surface 21 of the fixed portion 20 and the facing surface 31 of the movable portion 30. As shown in FIG. 1, the upper fixed portion side straining portion 41 and the upper movable portion side straining portion 42 have the outer side surface (inner side surface 43) of the upper beam portion 40 facing the lower beam portion 50. It is formed by denting (upper side). The upper fixed portion side straining portion 41 and the upper movable portion side straining portion 42 are, for example, as shown in FIG. 1, a thin portion formed by a surface recessed outward in an arc shape on the inner side surface 43.

The lower beam portion 50 is a plate-shaped portion extending facing the upper beam portion 40 between the fixed portion 20 and the movable portion 30, and the facing surface 21 of the fixed portion 20 and the movable portion 30 face each other. It extends orthogonally or substantially orthogonally to the surface 31. Further, the lower fixed portion side straining portion 51 as the fixed portion side straining portion of the lower beam portion 50 and the lower movable portion side straining portion 52 as the movable portion side straining portion of the lower beam portion 50 are shown in the figure. As shown in 2, it extends parallel to or substantially parallel to each other in the thickness direction, and extends along the facing surface 21 of the fixed portion 20 and the facing surface 31 of the movable portion 30. As shown in FIG. 1, in the lower fixed portion side straining portion 51 and the lower movable portion side straining portion 52, the surface (inner side surface 53) of the lower beam portion 50 facing the upper beam portion 40 is outside. It is formed by denting (lower side). The lower fixed portion side straining portion 51 and the lower movable portion side straining portion 52 are, for example, as shown in FIG. 1, a thin portion formed by a surface recessed outward in an arc shape on the inner side surface 53.

The stopper portion 60 is formed between the upper beam portion 40 and the lower beam portion 50, that is, the stopper protruding portion 70 and the pair of stopper contact portions 81 and 82 are formed between the upper beam portion 40 and the lower side. It is formed between the beam portion 50 and the beam portion 50.

The stopper protrusion 70 extends from the facing surface 21 of the fixed portion 20 along the upper beam portion 40 and the lower beam portion 50, and is the same as the upper beam portion 40 and the lower beam portion 50 as shown in FIG. Alternatively, they have substantially the same thickness (dimensions in the direction perpendicular to the paper surface in FIG. 1). The stopper protrusion 70 does not have to have the same thickness as the upper beam portion 40 and the lower beam portion 50.

Specifically, the stopper protruding portion 70 includes a stopper base 71 protruding from the facing surface 21 of the fixed portion 20 toward the movable portion 30, and a stopper tip portion 72 protruding from the stopper base 71 toward the movable portion 30. Have. As shown in FIGS. 1 and 2, the width of the stopper tip portion 72 is smaller than the width of the stopper base portion 71. The width is a dimension in the distance direction (vertical direction in FIG. 1) between the upper beam portion 40 and the lower beam portion 50.

A pair of stoppers facing each other in the width direction are provided on the tip portion 73 of the stopper protrusion 70, which is a portion extending a predetermined length in the length direction from the tip (tip 72a) of the stopper tip portion 72 to the fixing portion 20 side. The protrusion contact portions 74 and 75 are formed. Further, a constricted portion 76 is formed in the stopper tip portion 72. The constricted portion 76 is located closer to the fixed portion 20 than the pair of stopper protruding portion contact portions 74 and 75 in the extending direction (length direction) of the stopper protruding portion 70, and the pair of stopper protruding portion contact portions 74 and 75. It is a part that is more constricted, that is, a part that is formed to have a smaller dimension in the width direction. Specifically, as shown in FIG. 1, the constricted portion 76 is formed in the stopper tip portion 72 following the tip portion 73 and is connected to the stopper base portion 71. In the tip portion 73, the stopper protrusion contact portions 74 and 75 may be separated from the constricted portion 76, and the stopper protrusion contact portions 74 and 75 may be separated from the tip 72a. good.

The stopper protrusion contact portion 74 faces the upper stopper contact portion 81, which is one of the pair of stopper contact portions, from below, and the stopper protrusion contact portion 75 is a pair of stopper contact portions. It faces the other lower stopper contact portion 82 from above. The upper stopper contact portion 81 and the lower stopper contact portion 82 extend from the facing surface 31 of the movable portion 30 along the stopper protrusion 70, and as shown in FIG. 2, the upper beam portion 40 and the lower beam It has the same or substantially the same thickness as the portion 50. The upper stopper contact portion 81 and the lower stopper contact portion 82 do not have to have the same thickness as the stopper protrusion 70.

Further, the upper stopper contact portion 81 is provided between the upper fixed portion side strain generating portion 41 and the upper movable portion side strain generating portion 42, and the lower stopper contact portion 82 is provided between the upper fixed portion side strain generating portion 41 and the lower stopper contact portion 82. It is provided between the portion 51 and the lower movable portion side straining portion 52. As shown in FIGS. 1 and 2, the stopper portion 60 has a stopper accommodating portion 80 that accommodates the tip portion 73 of the stopper protruding portion 70 in the width direction. The stopper accommodating portion 80 has an upper stopper contact portion 81 and a lower stopper contact portion 82, and a space is formed on the movable portion 30 side so that the tip portion 73 of the stopper protruding portion 70 can be accommodated. There is. Specifically, in the stopper accommodating portion 80, a space 83 is formed on the movable portion 30 side of the tip 72a of the stopper tip portion 72. The space 83 extends in the thickness direction of the stopper accommodating portion 80. Further, the space 83 extends upward beyond the upper stopper contact portion 81 in the width direction, and extends downward beyond the lower stopper contact portion 82. The space 83 communicates with a bolt hole 32 for fixing the wire mounting portion 90, which will be described later, and when the fixing bolt 92 for fixing the wire mounting portion 90 is screwed into the bolt hole 32, the fixing bolt The tip 92a of the 92 can enter the space 83. That is, the space 83 forms an escape space for the fixing bolt 92. As shown in FIG. 1, the movable portion side edge portion 83a, which is the edge portion on the movable portion 30 side of the space 83, is the end portion of the movable portion side straining portions 42, 52 on the movable portion 30 side in the length direction. It is preferable that the fixed portion 20 is located closer to the fixed portion 20 than the end portions 42a and 52a), or is located on the same plane. The space 83 may extend in the width direction so as to form an escape space for the fixing bolt 92, and is outside (upper and lower) beyond the upper stopper contact portion 81 and the lower stopper contact portion 82. It does not have to extend to. However, it is preferable that the space 83 extends outward beyond the upper stopper contact portion 81 and the lower stopper contact portion 82 for wire cutting described later.

More specifically, in the length direction, the stopper protrusion contact portions 74, 75 and the stopper contact portions 81, 82 of the stopper protrusion 70 have the central surface A in the length direction and the movable portion side straining portion 42, It is provided between 52 and 52. The central surface A in the length direction is a surface orthogonal to the length direction in the central portion in the length direction between the fixed portion side straining portions 41 and 51 and the movable portion side straining portions 42 and 52. Further, it is preferable that the center of the stopper protrusion contact portions 74 and 75 in the width direction coincides with or substantially coincides with the center of the block body 2 in the width direction, and the upper stopper contact portion 81 and the lower stopper contact portion 81. It is preferable that the center in the width direction between the portions 82 coincides with or substantially coincides with the center in the width direction of the block body 2. Further, the distance (width W1) in the width direction from the side portion (outer surface 85) of the stopper accommodating portion 80 on the upper beam portion 40 side to the upper stopper contact portion 81 and the lower beam portion 50 of the stopper accommodating portion 80. It is preferable that the distance (width W2) in the width direction from the side portion (outer surface 86) to the lower stopper contact portion 82 is the same or substantially the same, and the width of the tip portion 73 of the stopper protrusion 70. It is more preferable that the dimensions (width W3), width W1 and width W2 in the direction are the same or substantially the same.

FIG. 3 is a partially enlarged view of the stopper portion 60 in the load transducer 1 according to the embodiment of the present invention. As shown in FIG. 3, the upper stopper protrusion contact portion 74 in the tip portion 73 of the stopper protrusion 70 faces the upper stopper contact portion 81 via the gap c, and the tip of the stopper protrusion 70 The lower stopper protrusion contact portion 75 in the portion 73 faces the lower stopper contact portion 82 via the gap c. The size of the gap c is set so that the strain-causing portions 41, 42, 51, and 52 are not damaged by the displacement of the movable portion 30 due to the load. The size of the gap c is set to, for example, a size corresponding to the amount of displacement of the movable portion 30 upward or downward when a load of 150% of the maximum measurable load (rated load) is applied.

The block body 2 is integrally formed of a metal material such as aluminum or iron. That is, the fixed portion 20, the movable portion 30, the beam portions 40, 50, and the stopper portion 60 are each part of the block body 2 integrally formed of the same material. As shown in FIG. 1, the beam portions 40, 50 and the stopper protruding portion 70 may be integrated on the fixed portion 20 side, and the beam portions 40, 50 and the stopper accommodating portion 80 are movable. It may be integrated on the unit 30 side. In this case, as shown in FIG. 1, the inner side surface 43 of the upper beam portion 40, the outer (upper) surface (outer surface 77) of the stopper base 71 and the constricted portion 76, and the outer side (upper side) of the stopper accommodating portion 80. The surface (outer surface 85) forms a space 6 extending in the thickness direction. Further, as shown in FIG. 1, the inner side surface 53 of the lower beam portion 50, the outer (lower) surface (outer surface 78) of the stopper base 71 and the constricted portion 76, and the outer side (lower) of the stopper accommodating portion 80. The side surface (outer surface 86) forms a space 7 extending in the thickness direction.

Further, strain gauges 3 are attached to the strain generating portions 41, 42, 51, 52 from the outside, and the upper beam portion 40 and the strain gauge 3 are resin covers which are resin covers from the outside (upper side). The lower beam portion 50 and the strain gauge 3 are also covered by the resin cover 5 which is a resin cover from the outside (lower side).

FIG. 4 is a cross-sectional view schematically showing a configuration of a load transducer according to an embodiment of the present invention in a state of use attached to a wire saw. The load transducer 1 is bolted to a plurality of bolt holes 22 of the fixing portion 20 in a state where the facing surface 21 of the fixing portion 20 and the back facing surface 23 facing back are in contact with the support member 100 for fixing the load converter 1. The 101 is screwed into the support member 100 and fixed to the support member 100. Further, in the load transducer 1, the fixing bolt 92 is screwed into the bolt hole 32 of the movable portion 30, and the wire mounting portion 90 around which the wire 91 is wound is fixed to the movable portion 30.

The load transducer 1 receives the load F from the wire 91 by applying the load F in the width direction to the wire 91 fixed to the wire mounting portion 90, causes bending, and moves in the width direction. As described above, in the load transducer 1, the fixed portion 20 has a fixed end and the movable portion 30 has a free end, and the load converter 1 is cantilevered and supported by the support member 100.

The load transducer 1 acts as a reverbal type strain-causing body, and the strain-causing portions 41, 42, 51, 52 are deformed by the load received by the load converter 1, and this load is electrically applied via the strain gauge 3. Detected. Specifically, in the load transducer 1, when the load F is received from the wire 91, the movable portion 30 is displaced, and the upper fixed portion side straining portion 41, the upper movable portion side straining portion 42, and the lower fixed portion side raising. Stress is generated in the strained portion 51 and the strained portion 52 on the lower movable portion side, and strain is generated. The strain gauge 3 detects a change in resistance due to strain in the upper fixed portion side straining portion 41, the upper movable portion side straining portion 42, the lower fixed portion side straining portion 51, and the lower movable portion side straining portion 52. Then, a measurement circuit (not shown) such as a bridge circuit can calculate the load applied to the wire 91 by arithmetically processing the change in the resistance of each strain gauge 3.

On the other hand, for example, when the wire attachment portion 90 around which the wire 91 is wound is attached to the movable portion 30 by the fixing bolt 92, the movable portion 30 is displaced so as to cause damage to the strain generating portions 41, 42, 51, 52. Even when a load is applied, the upper stopper contact portion 81 abuts on the stopper protrusion contact portion 74, or the lower stopper contact portion 82 abuts on the stopper protrusion contact portion 75. As a result, the displacement of the movable portion 30 to the extent that the strain-causing portions 41, 42, 51, and 52 are damaged is prevented from being displaced upward or downward, and the load converter 1 can be prevented from being damaged. At this time, the upper stopper contact portion 81 is provided between the upper fixing portion side strain generating portion 41 and the upper movable portion side straining portion 42, and the lower stopper contact portion 82 is provided between the lower fixing portion side strain generating portion 51. By providing the space between the strain gauge 3 and the strain gauge 52 on the lower movable portion side, it is possible to prevent the load transducer 1 from being damaged without lowering the sensitivity of the detected value of each strain gauge 3.

Further, as described above, the tip 92a beyond the movable portion 30 (opposing surface 31) of the fixing bolt 92 enters the space 83 of the stopper accommodating portion 80, and the space 83 provides the escape portion of the tip 92a of the fixing bolt 92. Is forming. As a result, even when a load is applied to the movable portion 30 and the movable portion 30 is displaced, the tip 92a of the fixing bolt 92 does not interfere with the portion of the block body 2, and the upper fixing portion side straining portion 41, It is possible to prevent interference with the deformation of the upper movable portion side distorted portion 42, the lower fixed portion side distorted portion 51, and the lower movable portion side distorted portion 52. Therefore, the detected value of the strain gauge 3 can be made accurate.

Further, the upper beam portion 40, the lower beam portion 50, and the stopper portion 60 in the block body 2 can be formed by forming spaces 6 and 7, and in the stopper portion 60, the stopper tip portion 72 of the stopper protrusion 70 is formed. The stopper accommodating portion 80 can be formed by forming the stopper contact portions 81, 82 and the stopper protruding portion contact portions 74, 75 by wire cutting after forming the space 83. As described above, the production of each part of the block body 2 is easy, and the processing cost can be reduced. In particular, the number of portions formed by wire cutting can be reduced, and the processing cost can be further reduced. If the wire is cut after the constricted portion 76 is formed, the wire cutting process can be further shortened.

Further, as described above, the stopper protrusion contact portions 74 and 75 and the stopper contact portions 81 and 82 are movable by being provided between the central surface A in the length direction and the movable portion side straining portions 42 and 52. The stopper contact portions 81, 82 and the stopper protrusion contact portions 74, 75 can be provided at positions where the displacement amount of the portion 30 is large, the width of the gap c can be widened, the machining accuracy can be improved, and the machining accuracy can be improved. The cost can be reduced and the processing time can be shortened. Further, the movable portion side edge portion 83a of the space 83 is provided on the fixed portion 20 side or on the same plane as the end portions 42a, 52a on the movable portion 30 side of the movable portion side straining portions 42, 52 in the length direction. Therefore, it is possible to reduce the size in the length direction. Further, the width W3 of the tip portion 73 of the stopper protrusion 70, the width W1 of the stopper accommodating portion 80 from the outer surface 85 on the upper beam portion 40 side to the upper stopper contact portion 81, and the lower side of the stopper accommodating portion 80. The width W2 from the outer surface 86 on the beam portion 50 side to the lower stopper contact portion 82 has the same or substantially the same value, so that the tip portion 73 of the stopper protrusion 70 and the stopper contact portions 81, 82 Rigidity can be secured to the same degree. Therefore, it is possible to prevent a large load from being applied to any portion of the stopper portion 60, and it is possible to improve the durability of the stopper portion 60.

As described above, according to the load transducer 1 according to the present invention, it is possible to prevent damage due to overload even when the size is reduced. Further, according to the load transducer according to the present invention, damage due to overload is prevented without lowering the sensitivity of the strain generating portions 41, 42, 51, 52, that is, without lowering the strain detection accuracy. be able to.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments of the present invention, and includes all aspects included in the concept of the present invention and the scope of claims. In addition, each configuration may be selectively combined as appropriate so as to achieve at least a part of the above-mentioned problems and effects. For example, the shape, material, arrangement, size, etc. of each component in the above embodiment can be appropriately changed depending on the specific usage mode of the present invention.

Further, as the load transducer 1, the upper stopper contact portion 81, the stopper protrusion contact portion 74, the lower stopper contact portion 82, and the lower stopper contact portion 82 are provided so that the upper and lower gaps c extend in parallel in the length direction. The embodiment of the present invention has been described by taking the case where the stopper protrusion contact portions 75 are formed in parallel as an example, but the form of the gap c is not limited to this. For example, as shown in FIG. 5, each gap c may extend diagonally outward (upper or lower) from the fixed portion 20 side toward the movable portion 30 side while maintaining a constant interval. That is, the width in the width direction of the portion of the stopper tip portion 72 where the stopper protrusion contact portions 74 and 75 are formed (the tip portion 73 in the present embodiment) is movable from the fixed portion 20 side in the length direction. It is formed in a tapered shape so as to increase toward the portion 30 side. Similarly, the stopper contact portions 81 and 82 are formed in parallel with the stopper protrusion contact portions 74 and 75, respectively, and the stopper contact portions are formed. The distance between 81 and 82 in the width direction may be formed in a tapered shape so as to increase from the fixed portion 20 side to the movable portion 30 side in the length direction. As a result, even when an overload that displaces the movable portion 30 to the extent that the strain-causing portions 41, 42, 51, and 52 are damaged is applied, the upper stopper contact portion 81 is attached to the stopper protrusion contact portion 74. Surface contact is possible, or the lower stopper contact portion 82 can surface contact with the stopper protrusion contact portion 75, and the load on the stopper portion 60 can be dispersed. Further, the upper and lower gaps c may have a non-constant interval in the direction orthogonal to the extending direction over the extending direction from the fixed portion 20 side to the movable portion 30 side. For example, the gaps c may be increased in the extending direction from the fixed portion 20 side to the movable portion 30 side. In this case, since the displacement of the stopper contact portions 81 and 82 is larger as it is closer to the movable portion 30, the contact between the stopper protrusion contact portions 74 and 75 and the stopper contact portions 81 and 82 is more reliably surfaced. Can be in contact.

Further, although the embodiment of the present invention has been described as an example of the case where the stopper protrusion 70 extends from the fixed portion 20 toward the movable portion 30 side as the load transducer 1, the embodiment of the present invention has been described. It may extend toward, and may have a plurality of stopper portions 60.

1 ... load transducer, 2 ... block body, 3 ... strain gauge, 4,5 ... resin cover, 6,7 ... space, 20 ... fixed part, 21 ... facing surface, 22 ... bolt hole, 23 ... back facing surface, 30 ... Movable part, 31 ... Facing surface, 32 ... Bolt hole, 40 ... Upper beam part, 41 ... Upper fixed part side straining part, 42 ... Upper movable part side straining part, 42a ... End part, 43 ... Inner surface , 50 ... lower beam portion, 51 ... lower fixed portion side straining portion, 52 ... lower movable portion side straining portion, 52a ... end portion, 53 ... inner surface surface, 60 ... stopper portion, 70 ... stopper protruding portion, 71. ... Stopper base, 72 ... Stopper tip, 72a ... Tip, 73 ... Tip, 74,75 ... Stopper protrusion contact, 76 ... Constriction, 77, 78 ... Outer surface, 80 ... Stopper accommodating, 81 ... Upper stopper contact portion, 82 ... Lower stopper contact portion, 83 ... Space, 83a ... Movable part side edge portion, 85, 86 ... Outer surface, 90 ... Wire mounting portion, 91 ... Wire, 92 ... Fixing bolt, 92a ... tip, 100 ... support member, 101 ... bolt

Claims (5)

With a block body,
With a strain gauge attached to the block body,
The block body has a fixed portion fixed to a support member, a movable portion facing the fixed portion and receiving a load from the outside, and a pair of beams extending between the fixed portion and the movable portion and facing each other. It has a portion and a stopper portion provided between the pair of beam portions to regulate the displacement of the movable portion.
Each of the pair of beam portions has a fixed portion side straining portion provided on the fixed portion side and a movable portion side straining portion provided on the movable portion side.
The stopper portion includes a stopper protrusion extending from the fixed portion toward the movable portion side, and a pair of stopper contact portions formed so as to be able to contact each other on the pair of beam portions side with respect to the stopper protrusion portion. Have and
The pair of stopper contact portions are provided between the fixed portion side straining portion and the movable portion side straining portion of the pair of beam portions .
The stopper portion has a stopper accommodating portion for accommodating the stopper protruding portion on the movable portion side, and the stopper accommodating portion has the pair of stopper contact portions.
In the stopper accommodating portion, a space is formed on the movable portion side of the stopper protruding portion.
The movable portion is provided with a wire attachment portion to which a wire is attached.
The wire mounting portion is fixed to the movable portion by screwing a fixing bolt into a bolt hole penetrating the movable portion.
The space, the load transducers in which the fixing bolt when screwed into the bolt hole, characterized Rukoto not enter the front end of the fixing bolt. It said pair of stopper contact portion, the load converter according to claim 1, characterized in that the contactable to the tip portion of the stopper protrusion. The load transducer according to claim 1 or 2 , wherein the stopper protrusion has a pair of stopper protrusion contact portions that face each other of the pair of stopper contact portions via a gap. The load transducer according to any one of claims 1 to 3 , wherein the fixed portion and the movable portion are disk-shaped flanges. The stopper protrusion has a constricted portion that is more constricted than the stopper protrusion contact portion at a position on the fixing portion side of the stopper protrusion contact portion in the extending direction of the stopper protrusion. The load transducer according to claim 4.

Images