TWI675195B - Load detector - Google Patents

Abstract

The load detector 5 is provided with a holding unit 8 including an inner ring portion 10 holding a shaft for supporting a load, and an inner ring portion 10 provided around the inner ring portion 10 and formed by a locking member at intervals in the circumferential direction. The plurality of mounting holes 11a1 and 112 are locked to the outer ring portion 11 of the mounting member, and two elastic portions 12 connecting the inner ring portion 10 and the outer ring portion 11; the differential transformer 9 is detected due to the load Displacement of the inner ring portion 10; and the recessed portion 13 is formed at the end of the outer ring portion side elastic portion belonging to the end of the outer ring portion side of the elastic portion 12, and is composed of a first recess portion 13a and a second recess portion 13b constituting the elastic portion Made up. In addition, the load detector 5A has a first low-rigidity portion 11c formed by the first recessed portion 13a, and the bending rigidity between the end of the elastic portion on the outer ring portion side and the mounting hole 11a1 is smaller than that of the outer ring portion. Other parts; and the second low-rigidity portion 11d is formed by the second recessed portion 13b, and has a bending rigidity below the first low-rigidity portion 11c between the end of the outer ring portion side elastic portion and the mounting hole 11a2.

Description

   Load detector   

The present invention relates to a load detector for detecting the tension acting on a coil of wire such as paper, cloth, film, metal foil, or a cable, as a load acting on a roller wound by the coil or wire.

In order to prevent defects such as wrinkles, sagging, and printing offset during the processing of winding, printing, etc. of the roll of paper, cloth, film, metal foil, etc., the tension acting on the roll must be controlled. The control of the tension is performed by detecting the load acting on the roll that winds the roll as the tension acting on the roll. The load acting on the drum is detected using a load detector. Most of the load detectors are bolted to the outer wall. When a load detector is mounted on an outer wall using a bolt, there is a problem that hysteresis, which is one of the detection performances, increases. In contrast, in the load detector described in Patent Document 1 described later, a portion having a bending rigidity smaller than that of the surrounding portion is provided between the elastic portion that is bent due to the detection load and the mounting hole, thereby reducing hysteresis.

    [Prior technical literature]         [Patent Literature]    

Patent Document 1: Japanese Invention Patent No. 6104487

However, the load detector of the aforementioned Patent Document 1 detects the load by the displacement generated by the load detector, and in this way, the detection output becomes smaller because the displacement is small, so the detection output will be affected by interference such as noise. The detection performance is easily reduced. In order to increase the displacement and ensure the required strength of the elastic portion, the length of the elastic portion can be considered. However, in the load detector of Patent Document 1, the elastic portion must be folded when the elastic portion is increased without changing the size of the load detector. Etc., making the structure complicated and increasing the manufacturing cost. In addition, only a portion having a lower bending rigidity than the surrounding portion is simply provided between the elastic portion and the mounting hole, and the reduction in hysteresis is limited.

The present invention has been developed by the present invention in order to solve the above-mentioned problems, and an object thereof is to provide a load detector with a structure that can be manufactured at a low cost, has strong anti-interference performance, and can further reduce hysteresis.

The load detector of the present invention includes a holding unit including a plurality of inner ring portions holding a shaft for supporting a load, a plurality of the ring portions provided around the inner ring portions, and formed by a locking member at intervals in the circumferential direction. Mounting holes for locking the outer ring portion of the mounting member, and a plurality of elastic portions connecting the inner ring portion and the outer ring portion; a displacement detecting portion that detects a displacement of the inner ring portion due to a load; and formed in The recessed part of the elastic part end of the elastic part which belongs to the end of the outer ring part side. The recessed portion is composed of a first recessed portion and a second recessed portion. The first recessed portion constitutes one surface of a surface belonging to one side of the elastic portion. The second recessed portion constitutes the other surface of the elastic portion. The other surface is the same as the one surface. Opposite side.

According to the present invention, it is possible to provide a load detector that can be manufactured at a low cost, has a strong anti-interference performance, and can further reduce hysteresis.

1‧‧‧ roll material (detection object)

2a, 2b, 2c‧‧‧ roller

3‧‧‧Drum axis

4‧‧‧bearing

5, 5A, 5B, 5C, 5D‧‧‧Load Detectors

6‧‧‧ spacer

6a‧‧‧force acting part

6b‧‧‧Connection Department

7‧‧‧Fixed components

8‧‧‧ holding unit

9‧‧‧ Differential transformer (displacement detection section)

9a‧‧‧differential transformer coil

9b‧‧‧ Differential transformer core

10‧‧‧Inner Ring Department

10a‧‧‧Load Support Department

10b‧‧‧ iron core fixing part

10c‧‧‧Inner ring hole

11‧‧‧ Outer Ring Department

11a1, 11a2‧‧‧ Mounting holes

11b‧‧‧Mounting and fixing part

11c, 11c1, 11c2, 11c3‧‧‧ the first low rigidity part

11d‧‧‧Second low rigidity

11e‧‧‧Measurement unit

12‧‧‧ Elastic Section

12a‧‧‧Outer ring side

12b‧‧‧Inner ring part side elastic part end

12c‧‧‧Elastic part forming end

13‧‧‧ recess

13a, 13a1, 13a2, 13a3‧‧‧ first recess

13b‧‧‧Second recess

14‧‧‧stop

15‧‧‧shell

16‧‧‧ Strain gauge

17a, 17b ‧‧‧ long hole

17c‧‧‧ Differential transformer mounting hole

A‧‧‧ Center

B, C‧‧‧Straight

F‧‧‧Load

L‧‧‧ length

T‧‧‧ tension

W‧‧‧ Weight

θs‧‧‧ included angle

Fig. 1 is a diagram showing a mounting structure of a load detector according to a first embodiment of the present invention.

Fig. 2 is a sectional view taken along the arrow I-I of Fig. 1.

Fig. 3 is a sectional view showing the arrow of the load detector taken along the line II-II in Fig. 1.

FIG. 4 is an explanatory diagram illustrating the relationship between the displacement and the stress of the elastic portion.

Fig. 5 is an enlarged sectional view showing a modification example of the shape of the recessed portion of the load detector of the first embodiment.

Fig. 6 is an enlarged cross-sectional view showing another modification of the concave portion of the load detector of the first embodiment.

FIG. 7 is an enlarged cross-sectional view showing another modified example of the concave portion of the load detector of the first embodiment.

FIG. 8 is a cross-sectional view showing a modification example of the load detector according to the first embodiment, and a modification example of the configuration including a stopper.

FIG. 9 is an enlarged sectional view of FIG. 8.

Fig. 10 is a cross-sectional view showing a modified example of the load detector of the first embodiment and showing a structure in which the elastic portion does not cross the straight line B.

Fig. 11 is a sectional view showing a modification example of the load detector according to the first embodiment, and showing a modification example of the configuration having a different detection structure.

Fig. 12 is a front view showing an example of a spacer used for mounting the load detector in the second embodiment.

Fig. 13 is a cross-sectional view showing an example of a mounting configuration of a load detector according to the second embodiment.

Fig. 14 is a sectional view showing a load detector according to the third embodiment.

Fig. 15 is a sectional view showing a load detector of the fourth embodiment.

Fig. 16 is an enlarged sectional view showing a stopper of the load detector of the fourth embodiment.

Fig. 17 is a sectional view showing a modification example of the shape of the recessed portion of the load detector in the fourth embodiment.

FIG. 18 is a cross-sectional view showing a modification example of the load detector according to the fourth embodiment, and showing a load detector using a plurality of displacement detection units.

Fig. 19 is a sectional view showing a modification example of the load detector according to the fourth embodiment, and showing a load detector having four mounting holes.

Fig. 20 is a sectional view showing a load detector according to a fifth embodiment.

(Implementation Mode 1)

Fig. 1 is a diagram showing the mounting structure of the load detector 5 according to the embodiment 1 of the present invention. Fig. 2 is a cross-sectional view of the arrow along the line II of Fig. 1 and Fig. 3 is a diagram along the line II of Fig. 1 -Arrow sectional view of the load detector 5 of line II. The X-axis direction in FIG. 1 is determined as the width direction of the load detector 5, the Y-axis direction is determined as the height direction of the load detector 5, and the Z-axis direction is determined as the depth direction of the load detector 5. The same symbols are used in the figure. The load detected by the load detector 5 acts in the ± Y direction.

A roll 1 as a detection target of paper, cloth, film, metal foil, and the like is wound on a first roll 2a, a second roll 2b, and a third roll 2c and transferred. Bearings 4 are fitted into both ends of the roller shaft center 3 of the shaft of the first roller 2a, respectively. Each bearing 4 is provided with a load detector 5 attached to a fixed member 7.

The load detector 5 of the embodiment 1 detects the load F acting in the Y-axis direction of the load detector 5 from the drum axis 3 through the bearing 4.

The load F acting on the load detector 5 is the total force of the tension T of the roll 1 as shown in FIG. 2, and the tension T can be expressed by the following formula.

T = (F-W) / 2cosθ (1)

Here, θ is an included angle shown in FIG. 2 and W is the weight of the drum 2a. The tension T can be obtained from the formula (1) by measuring the load F.

Since there is a proportional relationship between the load F and the displacement, and between the load F and the deformation, the load F can be detected by measuring the displacement or deformation generated by the constituent members of the load detector 5. Separately, the displacement detection system may use, for example, a differential transformer as the detection device, and the deformation detection system may use, for example, a strain gauge as the detection device.

The load detector 5 is provided with a holding unit 8 that receives a load F from the drum axis 3 in the Y-axis direction via a bearing 4; and a differential transformer 9 as a displacement detection unit that measures the configuration of the holding unit 8 due to the load F The displacement of the component.

The holding unit 8 has an inner ring portion 10, and an inner ring hole 10c receives a load from the roller shaft center 3, and a bearing 4 inserted through the roller shaft center 3 is embedded in the inner ring hole 10c. The ring portion 11 is formed on the outside of the inner ring portion 10 so as to surround the inner ring portion 10 and is fixed to the mounting member 7; and a plurality of (two in this example) elastic portions 12 are connected to the inner ring portion 10. And outer ring section 11. The thickness of the holding unit 8 in the Z-axis direction is the same.

The inner ring portion 10 includes: an annular load support portion 10a; an iron core fixing portion 10b extending from the load support portion 10a in the X-axis direction; and an inner ring hole 10c into which the bearing 4 is fitted.

The elastic portion 12 connects the inner ring portion 10 and the outer ring portion 11 and has: an outer ring portion side elastic portion end 12a, which is a joint portion between the elastic portion 12 and the outer ring portion 11, and is an outer ring portion of the elastic portion 12 An end portion on the side; and an inner ring portion side elastic portion end 12b, which is a joint portion between the elastic portion 12 and the inner ring portion 10, and is an end portion on the side of the inner ring portion of the elastic portion 12. The elastic portion 12 is formed linearly from the outer ring portion side elastic portion end 12a to the inner ring portion side elastic portion end 12b.

In addition, the outer ring portion 11 is installed closest to the outer ring portion side elastic portion end 12a among the outer ring portion side elastic portion end 12a and a plurality of (three in this example) mounting holes 11a1, 11a2, and 11a2 described later. Between the holes 11 a 1, a first recessed portion 13 a is formed so as to be adjacent to the elastic portion 12. The first recessed portion 13 a constitutes one surface that belongs to one side of the elastic portion 12. Similarly, the outer ring portion 11 is located between the outer ring portion side elastic portion end 12a and the three mounting holes 11a1, 11a2, and 11a2, which are the second closest mounting holes 11a2 from the outer ring portion side elastic portion end 12a. Adjacent to the elastic portion 12, a second recessed portion 13 b is formed. The second recessed portion 13 b constitutes another surface, which belongs to a surface opposite to one surface of the elastic portion 12.

Incidentally, if the portions of the elastic portion 12 corresponding to the opening ends of the first concave portion 13a and the second concave portion 13b are set as the elastic portion forming ends 12c, when the pair of concave portions 13 are not formed in the outer ring portion 11, the elastic portion The forming end 12c corresponds to the outer ring portion side elastic portion end.

The outer ring portion-side elastic portion end 12a and the inner ring portion-side elastic portion end 12b are located on opposite sides with respect to the straight line B passing through the center A of the inner ring hole 10c in the Y direction, and the elastic portion 12 is transverse to the straight line B. Further, the inner ring portion side elastic portion end 12b is provided at a position farthest from the outer ring portion side elastic portion end 12a in the X-axis direction of the load supporting portion 10a. The length direction of the elastic portion 12 is perpendicular to the direction of the detection load, and the two elastic portions 12 are parallel to each other.

The outer ring portion 11 includes: mounting holes 11a1, 11a2, and 11a2. A plurality of (three in this example) are formed at regular intervals in the circumferential direction for mounting on the fixing member 7 for mounting bolts, etc .; the mounting fixing portion 11b, It is located around the mounting holes 11a1, 11a2, and 11a2, and bears the force for mounting the load detector (such as the locking force caused by bolts). The first low-rigidity portion 11c is located at the end of the elastic portion on the outer ring portion side. The first recessed portion 13a is formed between 12a and the mounting hole 11a1 closest to the elastic portion end 12a of the outer ring portion side; the second low rigidity portion 11d is located between the elastic portion end 12a of the outer ring portion side and the outer ring portion side Between the second nearest mounting holes 11a2 of the elastic portion end 12a, there is a bending rigidity below the first low rigidity portion 11c; and the measuring device fixing portion 11e is a mounting portion of the differential transformer coil 9a belonging to the differential transformer 9.

Between the outer ring portion side elastic portion end 12a and the mounting hole 11a1 closest to the outer ring portion side elastic portion end 12a, the first low rigidity portion 11c has the smallest bending rigidity. In detail, the diameter of the first low-rigidity portion 11c is the thinnest between the outer ring portion-side elastic portion end 12a and the nearest mounting hole 11a1 of the outer ring portion-side elastic portion end 12a. A second low-rigidity portion 11d having a thickness in the radial direction of the outer ring portion 11 that is equal to or less than the thickness of the first low-rigidity portion 11c is provided between the mounting holes 11a2 of the outer ring-portion-side elastic portion end 12a. In addition, the bending rigidity referred to here is a value obtained by multiplying the Young's coefficient E of the material of the outer ring portion 11 by the second moment of section (also called the moment of inertia) I in the circumferential direction. In addition, when the load detector is mounted with a bolt, the mounting and fixing portion 11b is a range where the locking force of the bolt mainly acts. When the load detector 5 is fixed to the fixing member 7 with bolts, if the diameter of the bolt head for mounting is set to d, and the thickness in the Z-axis direction of the holding unit 8 is set to t, the size of the mounting and fixing portion 11b is determined. For example, a circle having a diameter d + 2t centered on the mounting hole 11a.

The holding unit 8 receives the load in either the + Y direction or the Y direction according to the installation method of the first roller 2a, the second roller 2b, and the third roller 2c with respect to the roll 1. Therefore, in addition to the iron core fixing, Except for the portion 10b, a line-symmetrical shape is formed with respect to a straight line passing through the center A of the inner ring hole 10c in the X-axis direction.

The differential transformer 9 is a differential transformer core 9b having an iron core fixing portion 10b fixed to the inner ring portion 10, and a differential transformer coil 9a fixed to a measuring device fixing portion 11e of the outer ring portion 11, and measures the differential Relative displacement in the Y-axis direction between the transformer coil 9a and the differential transformer core 9b. The differential transformer 9 detects displacement in a non-contact manner with the differential transformer coil 9a and the differential transformer core 9b. In contrast to the strain sensor used to detect deformation as a contact sensor, the differential transformer is a non-contact type of the differential transformer coil 9a and the differential transformer core 9b belonging to the detection site. Therefore, it has resistance to shock or vibration. Advantage of strong load. In addition, the differential transformer is different from the strain gauge used to detect deformation, and can be fixed by bolts without worrying about the deterioration of the adhesive. Therefore, compared with the detection based on the deformation gauge, it is easier to ensure the temperature and humidity environment. Long-term reliability of detection accuracy. In addition, a differential transformer can increase the detection output more easily than a strain gauge. Therefore, if it is used as a detection device, it is possible to obtain a load detector that is resistant to interference such as electrical noise.

The load detector 5 receives the load F in the Y-axis direction from the roller shaft center 3 via the bearing 4 through the load supporting portion 10a, and measures the bending due to the elastic portion 12 with the differential transformer 9 provided in the fixed portion 11e of the measuring device. The displacement generated in the iron core fixing portion 10b. In this load detector 5, since the displacement of the measuring instrument fixing portion 11e to which the differential transformer coil 9a is fixed is smaller than the displacement of the iron core fixing portion 10b, the measured displacement of the differential transformer 9 can be regarded as the one of the iron core fixing portion 10b. Y-axis displacement.

Next, the hysteresis which greatly affects the detection performance of the load detector 5 will be described. Hysteresis refers to the phenomenon that the detection output of load F is different before and after the loading of load F. The main reason for this is the slight deviation of the joint surface generated when the load F is loaded, and the load is not completely restored after removing the load F.

As described above, bolts are often used for mounting the load detector 5. However, if a slight deviation occurs in the mounting and fixing portion 11b when the load is loaded, the influence of the frictional force acting on the joint surface of the mounting and fixing portion 11b will be removed After the load, the offset will also be maintained and the hysteresis will occur.

The slight displacement of the joint surface of the mounting and fixing portion 11b is caused by the load F in the Y-axis direction, which causes a bending moment to act on the mounting and fixing portion 11b, and deforms the mounting and fixing portion 11b. Therefore, in order to reduce the hysteresis, it is necessary to reduce the bending moment acting on the mounting and fixing portion 11b to reduce the deformation of the outer ring portion 11 generated on the mounting and fixing portion 11b. In particular, the mounting hole closer to the outer ring portion side elastic portion end 12a is more affected by the bending moment, and the deformation generated in the mounting fixing portion 11b is likely to increase. Therefore, the elastic portion closest to the outer ring portion side is reduced. The deformation of the mounting and fixing portion 11b of the end 12a is important.

When the load detector does not have the recessed portion 13 (the first recessed portion 13a and the second recessed portion 13b), if the load F acts on the load detector, the outer ring portion side elastic portion end 12a is connected to the outer ring portion side elastic portion end 12a. The line segment of the nearest mounting hole 11a1 is deformed more than the surrounding area.

In this regard, in the load detector 5 of Embodiment 1, a recess 13 is provided in a line segment connecting the outer ring portion side elastic portion end 12a and the mounting hole 11a1 closest to the outer ring portion side elastic portion end 12a (details) The first recess 13a) can block the aforementioned deformation. Furthermore, since the bending rigidity of the first low-rigidity portion 11c is smaller than the bending rigidity of the outer ring portion 11 between the outer ring portion side elastic portion end 12a and the mounting hole 11a1 closest to the outer ring portion side elastic portion end 12a, The first low-rigidity portion 11c is preferentially deformed, and the influence of the bending moment of the mounting and fixing portion 11b can be reduced. Therefore, it is possible to reduce the deformation caused by the mounting and fixing portion 11b closest to the outer ring portion side elastic portion end 12a, and reduce the hysteresis.

In addition, the thickness of the outer ring portion 11 in the diameter direction is smaller than that of the surrounding first low-rigidity portion 11c. Compared with other portions of the outer ring portion 11, a large local deformation occurs. However, in the load detector 5 of the first embodiment, The first low-rigidity portion 11c is located between the outer ring portion side elastic portion end 12a and the mounting hole 11a1 closest to the outer ring portion side elastic portion end 12a, and is located at the position farthest from the mounting hole 11a1. Therefore, it is possible to reduce the deformation locally generated in the first low-rigidity portion 11c to affect the mounting hole 11a1 and the mounting fixing portion 11b around it, and to reduce the hysteresis.

The bending rigidity of the outer ring portion 11 applied to the mounting hole 11a2, which is the second closest to the end 12a of the outer ring portion side elastic portion, is not particularly limited. However, if the load detector 5 of the first embodiment is provided with the first low rigidity If the second low-rigidity portion 11d having a bending rigidity below the portion 11c is deformed, the second low-rigidity portion 11d will be deformed beyond the first low-rigidity portion 11c, and the influence of the bending moment can be further reduced. Thereby, the deformation caused by the mounting and fixing portion 11b closest to the outer ring portion side elastic portion end 12a is further reduced, and the hysteresis is further reduced. In addition, although the second low-rigidity portion 11d is deformed by more than the first low-rigidity portion 11c, if the second low-rigidity portion 11d is provided at a distance from the mounting hole 11a2 which is the second closest to the outer ring portion side elastic portion end 12a, The position can reduce the effect of the local deformation of the second low-rigidity portion 11d on the mounting and fixing portion 11b, and can reduce the hysteresis.

In addition, the recessed portion 13 not only reduces the hysteresis, because the recessed portion 13 is provided as a surface forming a part of the elastic portion 12, the elastic portion 12 can be grown without additional processing. Since the elastic portion 12 can be increased, it is possible to increase the displacement generated in the core fixing portion 10b, increase the detection output, and obtain a load detector with strong anti-interference performance.

Here, the influence of the length and thickness of the elastic portion 12 on the displacement and stress will be described using FIG. 4. Figure 4 simulates a cantilever beam with one end of the elastic portion 12 completely fixed and the other end free. The length direction of the cantilever beam in a state where no load is applied is defined as the X-axis direction, and a load F is applied at the free end in the −Y-axis direction. If the length of the cantilever in the X-axis direction is set to L, the thickness in the Y-axis direction is set to h, and the width in the Z-axis direction is set to b, the displacement δ at the free end and the maximum stress σ generated by the cantilever can be expressed as follows: Expression.

Here, the elastic modulus of the E-series cantilever beam, Refers to ratio. With this, the ratio of δ to σ, that is, δ / σ becomes the next equation.

To increase the displacement δ with respect to the stress σ generated by the cantilever beam, increase δ / σ. According to formula (4), δ / σ is proportional to the square of the length L and proportional to the negative square of h. Therefore, the method of increasing the length is relative to the stress δ compared to the method of reducing the thickness. The displacement σ can be effectively increased. In other words, the load detector 5 can effectively increase the displacement with respect to the stress δ when the length of the elastic portion 12 is increased compared to when the thickness of the elastic portion 12 is decreased. In other words, it is possible to obtain a load detector that ensures the necessary strength while increasing the detection output and obtaining a strong anti-interference performance.

In the load detector 5 according to the first embodiment, the mounting holes 11a1, 11a2, and 11a2 are three and are evenly arranged in the circumferential direction of the outer ring portion 11. However, if the load detector can be fixed to the fixing member 7, the mounting holes 11a1, The number and position of 11a2 and 11a2 are not particularly limited.

Furthermore, as in the recessed portion 13 (the first recessed portion 13a and the second recessed portion 13b) provided in the load detector 5 of Embodiment 1, if the width of the recessed portion 13 is increased to a gap between the elastic portion 12 and the inner ring portion 10, Or the width of the gap between the elastic portion 12 and the outer ring portion 11 is greater than the width, the recess 13 can be processed using the same tool as the processing of the gap. Therefore, it is possible to shorten the processing time and reduce the load of the load detector 5 without changing tools. manufacturing cost.

5 to 7 are enlarged cross-sectional views showing a modification example of the shape of the first recessed portion 13a provided in the load detector 5 according to the first embodiment. The first recessed portion 13 a is not limited to the shape shown in FIG. 3 and may be, for example, the shape shown in FIGS. 5 to 7. Specifically, in FIG. 5, the first recessed portion 13 a will have a direction from the inner peripheral side of the outer ring portion 11 toward the outer periphery. A first concave portion 13a1 with a semicircular front end on the side is provided in the outer ring portion 11 to form a first low-rigidity portion 11c1. The semicircular shape of the front end of the first recessed portion 13a1 can alleviate the stress concentration of the first low-rigidity portion 11c1. If the width of the first recessed portion 13a1 is increased, the radius of curvature of the front end of the first recessed portion 13a1 can be increased, so that stress concentration can be more relaxed. Furthermore, if the radius of curvature of the front end is increased, a large first low-rigidity portion 11c1 is formed in the circumferential direction of the outer ring portion 11, so that the amount of deformation of the first low-rigidity portion 11c1 becomes large, and the bending moment can be effectively reduced. This may affect the mounting and fixing portion 11b. Therefore, the deformation generated in the mounting and fixing portion 11b is reduced, and the hysteresis can be further reduced. FIG. 6 shows the first concave portion 13a2 having a quadrangular tip, and a portion having a bending rigidity smaller than that of the first low-rigidity portion 11c1 in FIG. 5 can be increased in the circumferential direction. The first recessed portion 13a3 in FIG. 7 is a circular hole. If the roller shaft center 3 can be supported by the inner ring portion 10 via the bearing 4, as shown in FIG. 7, the first recessed portion 13 a 3 can also reach the inner ring portion 10. When the first recessed portion 13a3 also crosses the inner ring portion 10, the diameter of the circular hole can be increased. In addition, since the first recessed portion 13a3 is a round hole, it can be easily processed by a lathe.

The outer ring end side elastic part end 12a and the inner ring end side elastic part end 12b of the elastic part 12 are located on the opposite side from the straight line B passing through the center A of the inner ring hole 10c in the Y direction. If the elastic part 12 crosses the straight line B , Its shape or number is not particularly limited, but if the load detector 5 (including a modified example of the form) of the first embodiment, if the elastic portion 12 is a line with respect to a straight line passing through the center A of the inner ring hole 10c in the X direction Symmetry, since the elastic portion 12 is symmetrically displaced regardless of the load acting in any of the ± Y directions, the load can be detected equally in both positive and negative directions. Furthermore, if the inner ring portion side elastic portion end 12b is provided at the position farthest from the load supporting portion 10a of the outer ring portion side elastic portion end 12a in the X-axis direction, and the elastic portion 12 and the inner ring portion 10 are coupled, it is possible to Increase the length of the elastic portion 12. Accordingly, since the displacement can be effectively ensured with respect to the stress, it is possible to increase the detection output and obtain a load detector having a strong anti-interference performance. Furthermore, if the longitudinal direction of the elastic portion 12 is set perpendicular to the detection load, the bending moment caused by the detection load causes the elastic portion 12 to be greatly bent, and the displacement generated by the inner ring portion 10 can be increased. Furthermore, if the width of the gap between the inner ring portion 10 and the elastic portion 12 forming the elastic portion 12 and the width of the gap between the outer ring portion 11 and the elastic portion 12 are increased, it is possible to make it difficult for foreign objects to block the gap. . Therefore, the displacement generated in the inner ring portion 10 and the elastic portion 12 is not suppressed by the foreign matter, and the reliability of the detection performance can be improved.

FIG. 8 shows a modification example of the load detector 5 of the first embodiment, and shows a cross-sectional view of the load detector 5 having the stopper 14 as a mechanism for preventing the elastic portion 12 from being damaged. FIG. 9 is a view of FIG. 8 An enlarged view of the stopper 14. The load detector 5 of FIG. 8 increases a part of the outer ring portion 11 of the load detector 5 of FIG. 3 (in detail, the portion facing the inner ring portion side elastic portion end 12b of the elastic portion 12) to the inside. A stopper 14 is provided to reduce the gap between the outer ring portion 11 and the elastic portion 12, thereby forming a long hole between the elastic portion 12 and the outer ring portion 11. The other configurations are the same as those of the load detector 5 in FIG. 3.

In the load detector 5 of FIG. 9, by adjusting the gap between the stopper 14 and the elastic portion end 12 b of the inner ring portion side of the elastic portion 12, when the load is less than the allowable load of the load detector 5, The elastic portion 12 does not contact the stopper 14, but when a load exceeding an allowable load acts, the outer peripheral surface of the elastic portion 12 can contact the stopper 14. In this way, since deformation of the elastic portion 12 can be suppressed, damage to the elastic portion 12 can be prevented.

In addition, if it has a function of preventing damage to the elastic portion 12, the shape or position of the stopper 14 is not particularly limited, but if the gap between the surface of the stopper 14 and the surface of the elastic portion 12 is set to be fixed, The area where the interval becomes fixed (the portion where the elastic portion 12 and the outer ring portion 11 have the same shape) is in contact, and therefore, the contact area is larger than that in a contact having a different shape. Therefore, the contact stress is reduced, and deformation and damage of the contact portion can be suppressed.

Further, if the stopper 14 is provided so that the outer ring portion 11 contacts the elastic portion 12 at a position where the displacement of the elastic portion 12 near the elastic portion end 12b of the inner ring portion side is large, the stopper 14 can be increased. The width of the slit between the stopper 14 and the elastic portion 12. Therefore, the influence of the processing error of the slit width on the load of the elastic portion 12 and the stopper 14 is reduced, and the elastic portion 12 can be brought into contact with the stopper 14 accurately under a specified load. The contact portion of the stopper 14 is not limited to the elastic portion 12, and the deformation of the elastic portion 12 can be suppressed so that the stopper 14 and the inner ring portion 10 are in contact with each other.

Furthermore, if one or both of the gap between the inner ring portion 10 and the elastic portion 12 forming the elastic portion 12 and the gap between the outer ring portion 11 and the elastic portion 12 are adjusted, the load detector 5 is exceeded. When the load of the permissible load is applied, the inner ring portion 10 and one portion of the elastic portion 12 or the outer ring portion 11 and one portion of the elastic portion 12 are brought into contact with each other, and it is not necessary to separately provide the outer ring portion 11 as shown in FIG. 9. The stopper 14 is partially enlarged inward.

The position and shape of the iron core fixing portion 10b belonging to the displacement measurement portion are not particularly limited, but the bending of the elastic portion 12 will increase the displacement of the iron core fixing portion 10b. Therefore, it is preferable to move away from the X axis direction. The inner ring portion side elastic portion end 12b is provided with an iron core fixing portion 10b and a differential transformer 9b.

The holding unit 8 of the load detector 5 (including a modification example thereof) of the first embodiment is composed of a single component, but may be composed of a plurality of components. For example, the outer ring portion 11 may be a part different from the inner ring portion 10 and the elastic portion 12, and the thickness of the outer ring portion 11 may be increased to be larger than that of the inner ring portion 10 and the elastic portion 12.

As the material of the holding unit 8, for example, iron-based materials such as carbon steel, high-tensile steel, rolled steel, stainless steel, and alloy steel for components, and plated steel using these as base materials, or aluminum, magnesium, Materials such as titanium, brass, copper and alloy materials.

Fig. 10 is a cross-sectional view showing a modification example of the load detector 5 (including a modification example of the configuration) of the first embodiment and a structure in which the elastic portion does not cross the straight line B.

The outer ring portion-side elastic portion end 12a and the inner ring portion-side elastic portion end 12b may also be located on the same side with respect to the straight line B passing through the center A of the inner ring hole 10c in the Y direction. In other words, the elastic portion 12 may not be transected. Straight line B. The other structures are the same as those in FIG. 3. Since the elastic portion 12 is shortened, the stress generated by the elastic portion 12 is reduced due to the detection load, so that the strength and reliability of the elastic portion 12 can be improved.

FIG. 11 is a cross-sectional view showing another detection structure of the load detector 5 (including a modification example of the shape) of the first embodiment.

The load detector 5 in FIG. 3 uses a differential transformer 9 to measure the displacement generated by the iron core fixing portion 10 b to detect the load F. However, in this modification example, a strain gauge 16 is attached to the elastic portion 12 instead of the differential transformer 9. . The strain gauge 16 is a deformation detection portion that detects the deformation amount of the elastic portion 12 deformed by the load F, that is, a deformation detection portion that detects the deformation of the elastic portion 12. The load F is detected based on the amount of deformation measured by the strain gauge 16. The other configurations are the same as those of the load detector 5 shown in FIG. 3.

In this modification of the form, the load F can be detected by using the strain gauge 16 having a higher detection sensitivity with respect to the deformation of the elastic portion 12 even if the displacement generated by the inner ring portion 10 is reduced. In other words, since the bending rigidity of the elastic portion 12 can be increased, the inner ring portion 10 can be firmly supported stably, and the load detector 5 having a high resonance frequency can be realized. Furthermore, since the differential transformer 9 is not used, it is not necessary to process the iron core fixing portion 10b of the inner ring portion 10 and the measuring device fixing portion 11e of the outer ring portion 11, and it is in phase with the load detector 5 shown in FIG. In comparison, the structure of the holding unit 8 can be simplified. The position where the strain gauge 16 is attached is not particularly limited, but if it is affixed near the end portion of the elastic portion 12 of the outer ring portion side elastic portion end 12a or the inner ring portion side elastic portion end 12b, the deformation can be large, so that it can be attached. Increase detection output.

(Embodiment 2)

Fig. 12 is a front view showing an example of the spacer 6 used for mounting the load detector 5A of the second embodiment. Fig. 13 is a side view showing an example of a mounting structure of a load detector 5A of the second embodiment using the spacer 6 of Fig. 11.

In the second embodiment, the front surface and the back surface of the load detector 5A are sandwiched by the spacer 6 shown in FIG. 12, and the load detector 5A is fixed to the fixing member 7 via the casing 15. Thereby, both end surfaces in the axial direction of the holding unit 8 are covered by the case 15. In addition, the housing 15 is arranged with a gap between the inner ring portion 10 and the elastic portion 12 respectively.

The spacer 6 plays a role of preventing the inner ring portion 10 and the elastic portion 12 from contacting other members such as the fixing member 7 in the installed state, and prevents the inner ring portion 10 and the elastic portion 12 from being deformed and caused by the deformation of the inner ring portion 10 and the elastic portion 12 when the load F acts. The friction of the components caused obstacles. The structure of the spacer 6 is not limited as long as the inner ring portion 10 and the elastic portion 12 do not contact other members in the installed state, but as shown in FIG. The force acting portion 6a of the portion in contact with the portion 11b, and reducing the connecting portion 6b connecting the force acting portion 6a can reduce the influence caused by the contact of the connecting portion 6b with the recessed portion 11c or the second low-rigidity portion 11d. In addition, the spacer 6 is not limited to a single component, and the force application portion 6a may not be connected by the connection portion 6b, but the force application portion 6a may be a plurality of components.

Except where the drum axis 3 passes, the housing 15 covers the entire surface of the holding unit 8 that is developed along the X-axis and the Y-axis, and is mounted on the outer side of each spacer 6 respectively. Since the housing 15 is provided, the load detector 5A can be protected from external contact or foreign matter. Furthermore, if a step or the like is provided in the housing 15 and the structure is provided so as to contact only the outer ring portion 11 and not the inner ring portion 10 and the elastic portion 12, since the spacer 6 is not required, the number of parts can be reduced. Improved workability. Furthermore, if the thickness in the Z-axis direction of the inner ring portion 10 and the elastic portion 12 is made smaller than that of the outer ring portion 11, it is possible to prevent the inner ring portion 10 and the elastic portion 12 from contacting the housing 15 without using the spacer 6. Therefore, it is possible to delete the spacer 6 and reduce the number of parts.

(Embodiment 3)

Fig. 14 is a sectional view showing a load detector 5B according to the third embodiment.

In the third embodiment, as shown in FIG. 14, the elastic portion 12 is bent at the elastic portion forming end 12c. Specifically, the elastic portion 12 includes a portion from the inner ring portion side elastic portion end 12b to the elastic portion forming end 12c of the elastic portion 12, and the elastic portion belongs to the recessed portion 13 (the first recessed portion 13a and the second recessed portion). 13b) The portion extending from the elastic portion forming end 12c to the outer ring portion side elastic portion end 12a of the portion corresponding to the open end has a different extending direction. In the elastic portion 12, the portion from the elastic portion forming end 12c to the outer ring portion side elastic portion end 12a is based on the recess portion 13 and the elastic portion forming end 12c is the base point. The outer ring portion side elastic portion end 12a is relatively installed. The hole 11a1 is formed in a curved manner so as to be distant. A first low-rigidity portion 11c is formed in the outer ring portion 11 by the first recessed portion 13a. Between the outer ring portion side elastic portion end 12a and the mounting hole 11a1 closest to the outer ring portion side elastic portion end 12a, the first The low rigidity portion 11c has the smallest bending rigidity. In addition, a second low-rigidity portion 11d is formed in the outer ring portion 11 by the second recessed portion 13b, and the mounting hole 11a2 at the outer ring portion side elastic portion end 12a is the second closest to the outer ring portion side elastic portion end 12a. There is a second low-rigidity portion 11d having a flexural rigidity below the first low-rigidity portion 11c. The other configurations are the same as those of the load detector 5 shown in FIG. 3.

According to the above structure, since the outer ring portion side elastic portion end 12a can be separated from the mounting hole 11a1 closest to the elastic portion forming end 12c, the deformation generated in the mounting hole 11a1 can be reduced and the hysteresis can be reduced. Furthermore, the thickness of the portion of the elastic portion 12 from the elastic portion forming end 12c to the outer ring portion side elastic portion end 12a in the elastic portion 12 can be easily adjusted by changing the position of the recessed portion 13 provided in the outer ring portion 11. The stress generated at the outer ring portion side elastic portion end 12a can be easily reduced. The bending rigidity of the outer ring portion 11 near the mounting hole 11a2 which is the second closest to the outer ring portion side elastic portion end 12a is not particularly limited. However, if the load detector 5B of FIG. 14 is provided, the bending rigidity is the first low. If the second low-rigidity portion 11d is less than the rigid portion 11c, the second low-rigidity portion 11d is deformed beyond the first low-rigidity portion 11c. Thereby, it is possible to further reduce the deformation generated at the mounting and fixing portion 11b1 closest to the outer ring portion side elastic portion end 12a, and further reduce the hysteresis. The shape of the concave portion 13 is not particularly limited. Although the load detector 5 in FIG. 14 is not provided with a stopper, for example, similar to the load detector 5 in FIG. 9, a stopper may be provided with a part of the outer ring portion close to the elastic portion 12.

(Embodiment 4)

Fig. 15 is a sectional view showing the load detector 5C of the fourth embodiment, and Fig. 16 is an enlarged view showing the stopper of Fig. 15.

In the load detector 5C of the fourth embodiment, in the same manner as the load detector 5B (FIG. 14) of the third embodiment, the portion of the elastic portion 12 from the inner ring portion side elastic portion end 12b to the elastic portion forming end 12c, The portion from the elastic portion forming end 12c to the outer ring portion side elastic portion end 12a of the elastic portion 12 is bent at the elastic portion forming end 12c and extends in a different direction.

Furthermore, in the load detector 5C of the fourth embodiment, the elastic portion 12 is partly circularly isolated from the elastic portion forming end 12c to the inner ring portion side elastic portion end 12b, and is different from those of the first to third embodiments. Like the load detectors 5 to 5B (including the modification example), the elastic portion forming end 12c to the inner ring portion side elastic portion end 12b are linear.

Specifically, the load detector 5C has a long hole 17a forming a surface on the outer side of the elastic portion 12, a long hole 17b forming a surface on the outer peripheral surface of the inner ring portion 10 and the inside of the elastic portion 12, and a differential transformer is mounted thereon. 9 differential transformer mounting hole 17c. Among them, a part of the long hole 17a and the long hole 17b is formed in a circular solitary shape. Therefore, a part of the elastic part 12 formed by these long holes 17a and 17b is also formed in an arc shape. In addition, the long hole 17a is connected to the differential transformer mounting hole 17c with a thin slit.

The elastic portion 12 is connected to the inner ring portion 10 at the position of the inner ring portion side elastic portion end 12b provided at the position of the load supporting portion 10a furthest from the outer ring portion side elastic portion end 12a in the X-axis direction, and is connected from the inner ring The portion-side elastic portion end 12b is formed in parallel to the X-axis direction until a portion where the elastic portion 12 meets the line B passing through the center A of the inner ring hole 10c in the Y direction.

Furthermore, the portion from the elastic portion forming end 12c to the outer ring portion side elastic portion end 12a of the elastic portion 12 is the mounting hole facing the outer ring portion side elastic portion end 12a closest to the elastic portion forming end 12c. 11a1 is formed in a direction away from each other, and is constituted by a first recessed portion 13a and an end portion in the longitudinal direction of a long hole 17a having a width in the diameter direction (as shown in FIG. 8 as a modification example of the load detector 5 in Embodiment 1 The second recessed portion is generally formed on the opposite side of the first recessed portion via the elastic portion 12). In addition, the widths in the radial direction of the long holes 17a and 17b and the width in the circumferential direction of the first recessed portion 13a are equal. The other configurations are the same as those of the load detector 5 shown in FIG. 3.

This load detector 5C is provided with the inner ring portion side elastic portion end 12b at the position farthest from the outer ring portion side elastic portion end 12a in the X-axis direction, so that the length of the elastic portion 12 can be increased. In addition, by forming a part of the elastic portion 12 in a circular solitary shape, the elastic portion 12 can be formed longer than a straight shape, and therefore, the displacement of the inner ring portion 10 can be increased. In other words, it is possible to increase the detection output and to obtain a load detector 5C having a strong anti-interference performance. In addition, in a portion where the length direction of the elastic portion 12 is perpendicular to the load direction, the bending moment caused by the load is used to effectively bend the elastic portion 12, and the displacement of the inner ring portion 10 can be obtained.

Moreover, since a part of the long hole is circularly solitary, when the long hole 17a and the long hole 17b are processed, the moving distance of the tool can be smaller than the linear movement. In particular, if the center of the circular solitary shape of the long hole 17b is aligned with the center A of the inner ring hole 10c, the space for inserting the inner ring hole 10c in the bearing 4 can be secured, and the moving distance of the processing tool can be reduced. Since the processing time of the long hole 17a and the long hole 17b can be shortened, the manufacturing cost of the load detector 5C can be reduced. In addition, one side of the elastic portion 12 of the elastic portion forming end 12c to the outer ring portion side elastic portion end 12a is formed by the lengthwise end portion of the long hole 17a having a width in the diameter direction, and no additional processing is required beyond the long hole 17a. . Therefore, the moving distance of the tool can be reduced, and the cost of the load detector 5C can be reduced. In addition, the elastic portion 12 is bent at the elastic portion forming end 12c, and the outer ring portion side elastic portion end 12a can be moved away from the mounting hole 11a1 closest to the elastic portion forming end 12c. Therefore, the deformation generated in the mounting hole 11a1 can be reduced. Reduce hysteresis.

The widths of the long holes 17a and 17b in the diameter direction and the width of the first recessed portion 13a are not particularly limited. However, if the load detector 5C of the fourth embodiment changes the widths of the long holes 17a and 17b in the radial direction and the first The width of one recessed portion 13a is set to be equal, and since the same processing can be performed with the same tool, no tool replacement is required. Therefore, the processing time can be shortened, and the cost of the load detector 5C can be reduced. In addition, if the width in the diameter direction of the long holes 17a and 17b is increased, it is possible to prevent foreign objects from being easily blocked between the inner ring portion 10 and the elastic portion 12 forming the elastic portion 12, and between the outer ring portion 11 and the elastic portion 12. . Therefore, the displacement generated by the inner ring portion 10 and the elastic portion 12 is not suppressed by the foreign matter, and the reliability of the detection performance can be improved.

Adjust the size of the slit connecting the long hole 17a and the installation hole 17c of the differential transformer. When the load is lower than the allowable load of the load detector 5C, the elastic portion 12 will not contact the outer ring portion 11, but the load exceeding the allowable load will act. In this case, the outer peripheral surface of the elastic portion 12 can be brought into contact with the outer ring portion 11. Thereby, deformation of the elastic portion 12 can be suppressed, and damage to the elastic portion 12 can be prevented.

The position of the slit connecting the long hole 17a and the mounting hole 17c of the differential transformer is not particularly limited, but if a slit is provided on a straight line connecting the center A of the inner ring hole 10c and the mounting hole 11a2, even if the long hole 17a is enlarged It is also easy to ensure the width and length of the mounting and fixing portion 11b. Further, if a slit is provided near the inner ring portion side elastic portion end 12b where the displacement of the elastic portion 12 is increased, the width of the slit can be increased. Therefore, the processing error of the width of the slits has a small effect on the load of the outer ring portion 11 and the elastic portion 12 in contact, and the elastic portion 12 can be brought into contact with the outer ring portion 11 with a predetermined load accuracy.

The bending rigidity of the outer ring portion 11 near the mounting hole 11a1, which is the second closest to the end 12a of the outer ring portion side elastic portion, is not particularly limited. However, the load detector 5C in FIG. 15 is used because of the circumferential direction of the outer ring portion. The elongated long hole 17a reduces the thickness of the outer ring portion 11 in the diameter direction near the mounting hole 11a2, which is the second closest to the outer ring portion side elastic portion end 12a, so that the outer ring portion 11 can be provided with a wide range of bending rigidity The second low-rigidity portion 11d is equal to or lower than the bending rigidity of the first low-rigidity portion 11c. When the second low-rigidity portion 11 d is provided in a wide range, the amount of deformation of the second low-rigidity portion 11 d is increased, so that the influence of the bending moment caused by the detection load can be further reduced. That is, it is possible to reduce the deformation occurring in the mounting and fixing portion 11 b and further reduce the hysteresis. As in the load detector 5C of FIG. 15, the inventors of the present invention provided the first recessed portion 13 a in order to increase the length of the elastic portion and reduce the hysteresis. Compared with the case where the first recessed portion 13 a is not provided, the hysteresis can be reduced. As small as about 0.6 times. When the second low-rigidity portion 11d having a bending rigidity smaller than that of the first low-rigidity portion 11c is provided between the mounting holes 11a2, which are closest to the outer ring portion side elastic portion end 12a, the first recessed portion 13a is not provided. In the case, it is found that the hysteresis can be reduced to about 0.4 times.

Fig. 17 is a sectional view showing a modification example of the shape of the first recessed portion in Fig. 15; The size of the first recessed portion 13a is not particularly limited, but the load detector 5C of FIG. 17 can also increase the diameter of the first recessed portion 13a, thereby increasing the length of the elastic portion 12 and reducing the ratio. The bending rigidity of the first low-rigidity portion 11c is intended to reduce the hysteresis.

FIG. 18 is a modification example of the shape of the load detector shown in FIG. 5 and a cross-sectional view of the load detector using a plurality of displacement detection sections. The number of displacement detection units 9 that detect displacement is not limited. For example, as shown in FIG. 18, an iron core fixing portion 10b may be provided on a straight line C passing through the center A of the inner ring hole 10c in the X direction, and two displacement detecting portions 9 may be mounted in a line-symmetrical manner with respect to the straight line C. By averaging the absolute value and the absolute value of the output of each displacement detection section 9 as the output of the load detector, a load detector with stronger anti-interference performance can be obtained. Alternatively, a combination of a displacement detection unit and a deformation detection unit such as a strain gauge may be used.

Fig. 19 is a modification example of the load detector shown in Fig. 15 and is a cross-sectional view of the load detector having four mounting holes. The position and number of the mounting holes are not particularly limited, and may be a load detector 5C as shown in FIG. 19.

The load detector 5C of FIG. 19 has four mounting holes 11a1 and 11a1 located at symmetrical positions with respect to the straight line B passing through the center A in the Y direction and the straight line C passing through the center A in the X direction. , 11a2, 11a2. In this load detector 5C, in order to provide the outer ring portion side elastic portion end 12a at a position away from the mounting hole 11a1, the elastic portion 12 has a circular solitary structure and extends to the vicinity of the straight line C, and has a bend belonging to the elastic portion 12. The elastic portion of the portion forms the end 12c. In the outer ring portion 11, a first low rigidity portion 11c is provided between the outer ring portion side elastic portion end 12a and the mounting hole 11a1 closest to the outer ring portion side elastic portion end 12a, and the outer ring portion side elastic portion A second low-rigidity portion 11d is provided between the end 12a and the mounting hole 11a2, which is the second closest to the end 12a of the outer ring portion side elastic portion. The bending rigidity of the first low-rigidity portion 11c is smallest between the outer ring portion side elastic portion end 12a and the mounting hole 11a1 closest to the outer ring portion side elastic portion end 12a. The bending rigidity of the second low-rigidity portion 11d is not particularly limited, but it is preferably less than or equal to the bending rigidity of the first low-rigidity portion 11c.

In this load detector 5C, the load detector 5C can be firmly attached to the fixing member 7 by increasing the mounting holes 11a1 and 11a2. In addition, since the necessary locking force can be secured by increasing the mounting holes 11a1 and 11a2, the diameter of the mounting hole 11a can be reduced by using a bolt with a smaller diameter. In addition, since the outer ring portion side elastic portion end 12 a is provided near the straight line C, the elastic portion 12 can be increased to increase the detection output.

(Embodiment 5)

Fig. 20 is a sectional view showing a load detector 5D according to the fifth embodiment.

In this load detector 5D, two elastic portions 12 extending linearly in a diametrical direction from the inner ring portion 10 to the outer ring portion 11 are provided on the same side with respect to a straight line C in the X direction passing through the center A of the inner ring hole 10c. The two elastic portions 12 are linearly symmetric with respect to a straight line B in the Y direction passing through the center A of the inner ring hole 10c. The elastic portion 12 forms an angle θs with the straight line C (X axis), and a part of the surface of the elastic portion 12 is constituted by the first concave portion 13a. In addition, the bending rigidity of the first low-rigidity portion 11c formed in the outer ring portion 11 by the first recessed portion 13a is smaller than the mounting hole 11a1 of the outer ring portion side elastic portion end 12a and the closest to the outer ring portion side elastic portion end 12a. The bending of the outer ring portions 11 is rigid. The bending rigidity of the outer ring portion 11 between the outer ring portion-side elastic portion end 12a and the mounting hole 11a2 closest to the outer ring portion-side elastic portion end 12a is not particularly limited, but it is preferable to provide the bending rigidity as The second low-rigidity portion 11d below the first low-rigidity portion 11c. The positions and numbers of the mounting holes 11a1 and 11a2 are not particularly limited, but in this example, three locations are provided at regular intervals in the circumferential direction of the outer ring portion 11, and the mounting holes 11a1 are located on the straight line B. The installation position of the differential transformer 9 is not particularly limited, but in this load detector 5D, from the viewpoint of ensuring the installation space of the differential transformer 9, the differential transformer 9 is installed on the elastic portion with respect to the straight line C The opposite side of 12 is provided with an iron core fixing portion 10b on a straight line B. The other structures are the same as those of the load detector 5 shown in FIG.

The elastic portion 12 is not particularly limited as long as it is linearly symmetric with respect to the straight line B.

Since the elastic portion 12 is linearly symmetric with respect to the straight line B, the trajectory of the displacement of the inner ring portion 10 does not become an arc shape, but a straight line parallel to the load direction (the Y-axis direction). Therefore, it is possible to obtain the detection performance. One is a load detector with good linearity. Furthermore, in the load detector 5D of FIG. 20, the distance between the mounting hole 11a and the outer ring portion side elastic portion end 12a can be easily adjusted by changing the angle θs.

Incidentally, the so-called linearity is an index indicating the magnitude of deviation of the measured value from the output of the differential transformer (the displacement of the inner ring portion 10) from an ideal straight line that is proportional to the detection load.

In addition, in the load detectors 5 to 5D of each of the above-mentioned embodiments (including a modification example of the form), the coil material 1 is described as the object to be wound on the drums 2a to 2c, but it may be a wire such as a cable.

In addition, the configuration of the roll material 1 and the rollers 2a to 2c is not particularly limited, and for example, the roll material 1 may be installed in the opposite direction to the rollers 2a to 2c.

In addition, if the drum 2a can be supported, the load detectors 5A to 5D (including the modification example) can support only one end, and the other end is not supported and is a free end, and does not support both ends of the drum shaft center 3. .

In addition, the load detectors 5A to 5D (including modification examples) use bolts belonging to the locking member for the fixing system of the fixing member 7, but this is only an example, and a locking member such as a screw may be used. In addition, in this case, the mounting and fixing portion 11 b is used to fix the load detectors 5A to 5D (including a modification example of the shape) to the portion where the force of the fixing member 7 is applied. It should be noted that the strain gauge is applicable not only to the first embodiment but also to the elastic portion 12 of the second to fifth embodiments.

Claims (15)

A load detector, comprising: a holding unit, comprising: an inner ring portion holding a shaft for supporting a load; surrounding the inner ring portion, provided by a plurality of locking members formed at intervals in the circumferential direction The mounting hole is locked to the outer ring portion of the mounting member; and a plurality of elastic portions connecting the inner ring portion and the outer ring portion; the displacement detection portion detects the displacement of the inner ring portion due to the load; And a recessed portion formed at the end of the outer ring portion-side elastic portion of the end portion of the elastic portion that belongs to the side of the outer ring portion, and constituting the elastic portion; the recessed portion is composed of a first recessed portion and a second recessed portion, which The first concave portion constitutes a surface belonging to one side of the elastic portion, and the second concave portion constitutes the other surface of the elastic portion, the other surface being the surface opposite to the aforementioned surface. A load detector, comprising: a holding unit, comprising: an inner ring portion holding a shaft for supporting a load; surrounding the inner ring portion, provided by a plurality of locking members formed at intervals in the circumferential direction The mounting hole is locked to the outer ring portion of the mounting member; and a plurality of elastic portions connecting the inner ring portion and the outer ring portion; the deformation detection portion detects the amount of deformation of the elastic portion deformed due to the load; And a recessed portion formed at the end of the outer ring portion-side elastic portion of the end portion of the elastic portion that belongs to the side of the outer ring portion, and constituting the elastic portion; the recessed portion is composed of a first recessed portion and a second recessed portion, which The first concave portion constitutes a surface belonging to one side of the elastic portion, and the second concave portion constitutes the other surface of the elastic portion, the other surface being the surface opposite to the aforementioned surface. The load detector as described in item 1 of the patent application range, wherein the second concave portion is constituted by a long hole constituting the other surface of the elastic portion. The load detector as described in item 2 of the patent application range, wherein the second concave portion is constituted by a long hole constituting the other surface of the elastic portion. The load detector according to any one of claims 1 to 4 includes a first low-rigidity portion formed by the first recessed portion in the outer ring portion, and The bending rigidity between the outer ring portion-side elastic portion end and the mounting holes closest to the outer ring portion-side elastic portion end of the plurality of mounting holes is smaller than other parts of the outer ring portion. The load detector as described in item 5 of the patent application includes a second low-rigidity portion formed on the outer ring portion by the second concave portion and on the outer ring portion side Between the end of the elastic portion and the mounting hole which is the second closest to the end of the elastic portion on the side of the outer ring portion among the plurality of mounting holes, it has bending rigidity equal to or lower than that of the first low-rigidity portion. The load detector according to any one of claims 1 to 4, wherein the elastic portion is formed to be a straight line that crosses the center of the inner ring portion and is parallel to the load direction that belongs to the direction of the load . The load detector according to any one of claims 1 to 4, wherein in the elastic portion, the elastic portion extends from the elastic portion end of the outer ring portion side to the open end belonging to the concave portion in the elastic portion The portion up to the end of the elastic portion of the corresponding portion is curved starting from the end where the elastic portion is formed, and away from the mounting hole closest to the end of the elastic portion on the outer ring side among the plurality of mounting holes. form. The load detector according to any one of claims 1 to 4, wherein the elastic portion and the inner ring portion are away from the end of the outer ring portion side elastic portion with respect to the direction of the load The position where the distance in the vertical direction of the load becomes the largest is connected. The load detector according to any one of items 1 to 4 of the patent application range, wherein the elastic portion is from the elastic portion forming end of the elastic portion belonging to a portion corresponding to the opening end of the concave portion to the The portion of the inner ring portion side end portion up to the inner ring portion side elastic portion end is formed in a linear shape. The load detector according to any one of claims 1 to 4, wherein in the elastic portion, at least a part of the elastic portion is formed in a direction perpendicular to the load direction that belongs to the direction in which the load acts . The load detector according to any one of claims 1 to 4, wherein in the elastic portion, at least a part of the elastic portion is formed in a circular arc shape. The load detector according to any one of claims 1 to 4, wherein the width in the diametrical direction of the gap between the elastic portion and the outer ring portion, between the elastic portion and the inner ring portion At least two of the width in the diameter direction of the gap and the width in the circumferential direction of the recessed portion are the same. The load detector according to any one of claims 1 to 4, wherein the elastic portion is arranged with respect to a straight line that passes through the center of the inner ring portion and is perpendicular to the load direction that belongs to the direction of the load In a position that becomes line symmetrical. The load detector according to item 1 or 3 of the patent application scope, wherein the displacement detection section is a differential transformer having a differential transformer coil and a differential transformer core, the differential transformer coil being fixed to the outer ring section The differential transformer core is fixed to the inner ring and relatively displaced with respect to the differential transformer coil.