WO2019021384A1

WO2019021384A1 - Load detector

Info

Publication number: WO2019021384A1
Application number: PCT/JP2017/027025
Authority: WO
Inventors: 雅也瀬良; 治彦角谷; 要寺田; 修一熊本; 公一井岡; 健治武原
Original assignee: 三菱電機株式会社
Priority date: 2017-07-26
Filing date: 2017-07-26
Publication date: 2019-01-31
Also published as: TW201910738A; JPWO2019021384A1; CN110998268A; CN110998268B; JP6504327B1; TWI675195B

Abstract

This load detector 5 is provided with: a holding unit 8 having an inner ring 10 which holds a shaft for supporting a load, the holding unit 8 also having an outer ring 11 which is provided surrounding the inner ring 10 and which is fastened to an installation member by fastening members passing through a plurality of installation holes 11a1, 11a2 formed at circumferential intervals, the holding unit 8 further having two springs 12 which connect the inner ring 10 and the outer ring 11; a differential transformer 9 for detecting the displacement of the inner ring 10 caused by a load; and recesses 13 formed in outer ring-side spring ends, i.e. the ends of the springs 12, which face the outer ring, and comprising first recesses 13a and second recesses 13b, the first and second recesses 13a, 13b constituting the springs 12. The load detector 5 is further provided with: first low rigidity sections 11c which are formed by the first recesses 13a, are located between the outer ring-side spring ends and the installation hole 11a1, and have bending rigidity lower than that of the remaining portion of the outer ring; and second low rigidity sections 11d which are formed by second recesses 13b, are located between the outer ring-side spring ends and the installation holes 11a2, and have bending rigidity lower than or equal to that of the first low rigidity sections 11c.

Description

Load detector

The present invention relates to a load detector which detects tension acting on a wire such as web, cable or the like such as paper, cloth, film or metal foil as a load acting on a roll on which these are wound.

In the winding, printing, and processing steps of a web such as paper, cloth, film, metal foil, etc., it is necessary to control the tension acting on the web in order to prevent defects such as wrinkles, deflection, and printing deviation. The control of tension is performed by detecting the tension acting on the web as a load acting on the roll wound by the web. A load detector is used to detect the load acting on the roll, and the load detector is often attached to an outer wall or the like using a bolt. When a load detector is mounted on an outer wall or the like using a bolt, there is a problem that hysteresis, which is one of detection performances, is increased. Therefore, in the load detector described in Patent Document 1, the hysteresis is reduced by providing a portion having a bending rigidity smaller than that of the periphery between the spring portion bent due to the detected load and the installation hole.

Patent No. 6104 487

By the way, in the load detector of the above-mentioned patent documents 1, load is detected by displacement which arises in the load detector concerned, and since detection output becomes small if displacement is small in this method, detection output is a disturbance such as noise Affected, detection performance is prone to decline. Although it is conceivable to increase the length of the spring portion in order to secure the necessary strength for the spring portion while increasing the displacement, in the load detector of Patent Document 1, the size of the load detector is changed. Instead, if the spring portion is to be elongated, the spring portion needs to be folded back, which complicates the structure and increases the manufacturing cost. Further, there is a limit to the reduction of the hysteresis by simply providing a portion having a bending stiffness smaller than that of the surroundings between the spring portion and the mounting hole.

The present invention has been made in view of the above, and an object of the present invention is to provide a load detector that is resistant to disturbances and can further reduce hysteresis with a structure that can be manufactured at low cost.

The load detector according to the present invention is fastened to the mounting member by the fastening member through the inner ring portion holding the shaft supporting the load, and a plurality of mounting holes provided surrounding the inner ring portion and formed at intervals in the circumferential direction. A holding unit having a plurality of spring portions connecting an outer ring portion and an inner ring portion and an outer ring portion, a displacement detection portion detecting a displacement of the inner ring portion caused by a load, and an outer ring portion which is an end of the spring portion on the outer ring portion side And a recess formed at the end of the side spring portion.

According to the present invention, it is possible to provide a compact load detector that is resistant to disturbances and can further reduce hysteresis with a low-cost and manufacturable structure.

FIG. 2 is a diagram showing an installation configuration of a load detector according to Embodiment 1. It is arrow sectional drawing along the I-I line of FIG. It is arrow sectional drawing which shows the load detector which followed the II-II line of FIG. It is an explanatory view explaining a relation of displacement of a spring part, and stress. FIG. 8 is an enlarged cross-sectional view showing a modification of the recess of the load detector according to the first embodiment. FIG. 14 is an enlarged cross-sectional view showing another modification of the recess of the load detector according to the first embodiment. FIG. 16 is an enlarged cross-sectional view showing another modification of the recess of the load detector according to the first embodiment. It is a modification of the load detector which concerns on Embodiment 1, Comprising: Sectional drawing which shows a modification provided with a stopper. It is an expanded sectional view of FIG. It is a modification of the load detector concerning Embodiment 1, and a sectional view of the structure where a spring part does not cross straight line B. It is a modification of the load detector concerning Embodiment 1, and is a sectional view showing the modification from which detection structure differs. It is a front view which shows an example of the spacer used for installation of the load detector which concerns on Embodiment 2. FIG. FIG. 7 is a cross-sectional view showing an example of an installation configuration of a load detector according to Embodiment 2. FIG. 10 is a cross-sectional view showing a load detector in accordance with a third embodiment. FIG. 14 is a cross-sectional view showing a load detector according to a fourth embodiment. FIG. 16 is an enlarged cross-sectional view showing a stopper of a load detector according to a fourth embodiment. FIG. 21 is a cross-sectional view showing a modification of the recess of the load detector according to the fourth embodiment. It is a modification of the load detector concerning Embodiment 4, and is a sectional view showing a load detector using a plurality of displacement detection parts. It is a modification of the load detector concerning Embodiment 4, and is a sectional view showing a load detector which has four installation holes. FIG. 14 is a cross-sectional view showing a load detector according to Embodiment 5;

Embodiment 1
FIG. 1 is a view showing an installation configuration of a load detector 5 according to Embodiment 1 of the present invention, FIG. 2 is a sectional view taken along the line II of FIG. FIG. 2 is an arrow sectional view showing a load detector 5 taken along line II-II in FIG. The X-axis direction in FIG. 1 is the width direction of the load detector 5, the Y-axis direction is the height direction of the load detector 5, the Z-axis direction is the depth direction of the load detector 5, and the same applies to the following figures. Use the code. The load detected by the load detector 5 acts in the ± Y direction.

The web 1 to be detected, such as paper, cloth, film, metal foil, etc., is wound around and transported by the first roll 2a, the second roll 2b, and the third roll 2c. Bearings 4 are fitted to both ends of the roll axis 3 which is the axis of the first roll 2a. A load detector 5 mounted on the fixing member 7 is attached to each bearing 4.

The load detector 5 of the first embodiment detects the load F in the Y-axis direction acting on the load detector 5 from the roll axis 3 via the bearing 4.

The load F acting on the load detector 5 is a total force of the tension T of the web 1 as shown in FIG. 2, and the tension T is expressed by the following equation.

T = (F−W) / 2 cos θ (1)
Here, θ is the holding angle shown in FIG. 2 and W is the weight of the roll 2a. By measuring the load F, the tension T can be obtained from the equation (1).

Since a proportional relationship is established between the load F and the displacement, and between the load F and the strain, the load F can be detected by measuring the displacement or strain generated in the component members of the load detector 5 . For example, a differential transformer is used for detecting displacement, and a strain gauge, for example, is used for detecting strain.

The load detector 5 is a holding unit 8 that receives a load F acting in the Y-axis direction from the roll axis 3 via the bearing 4, and a displacement detection unit that measures displacement generated in the components of the holding unit 8 by the load F. A differential transformer 9 is provided.

The holding unit 8 includes an inner ring portion 10 which receives a load from the roll axis 3 in an inner ring hole 10 c into which the bearing 4 into which the roll axis 3 is inserted is fitted, and the inner ring portion 10 so as to surround the inner ring portion 10. And an annular outer ring portion 11 fixed to the fixing member 7 and a plurality of (two in this example) spring portions 12 connecting the inner ring portion 10 and the outer ring portion 11. The thickness in the Z-axis direction of the holding unit 8 is uniformly formed.

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

The spring portion 12 connects the inner ring portion 10 and the outer ring portion 11 and is a joint portion of the spring portion 12 and the outer ring portion 11 and is an end of the outer ring portion side spring portion which is an end of the spring portion 12 on the outer ring portion side. An inner ring portion side spring portion end 12 b which is a connecting portion between the spring portion 12 and the inner ring portion 10 and which is an end on the inner ring portion side of the spring portion 12 is provided. The spring portion 12 is formed in a straight line from the outer ring portion side spring portion end 12 a to the inner ring portion side spring portion end 12 b.

Further, in the outer ring portion 11, the mounting hole 11a1 closest to the outer ring portion side spring portion end 12a among the outer ring portion side spring portion end 12a and a plurality of (three in this example) mounting holes 11a1, 11a2 and 11a2 described later. And a first recess 13a is formed adjacent to the spring portion 12, and the first recess 13a constitutes one surface which is one surface of the spring portion 12. Similarly, in the outer ring portion 11, a spring portion is formed between the outer ring portion side spring portion end 12a and the installation hole 11a2 closest to the outer ring portion side spring portion end 12a among the three installation holes 11a1, 11a2, 11a2. A second recess 13 b is formed to be adjacent to 12, and the second recess 13 b constitutes the other surface which is the surface on the opposite side to the one surface of the spring portion 12.

By the way, assuming that a portion corresponding to the opening end of the first recess 13a and the second recess 13b of the spring portion 12 is a spring portion forming end 12c, the spring portion forming end 12c has a pair of recess portions 13 formed in the outer ring portion 11. If not, it corresponds to the outer ring spring portion end.

The outer ring portion side spring portion end 12a and the inner ring portion side spring portion end 12b are on the opposite side to a straight line B in the Y direction passing through the center A of the inner ring hole 10c, and the spring portion 12 crosses the straight line B. Further, the inner ring portion side spring portion end 12 b is provided at a position farthest in the X axis direction of the load support portion 10 a of the inner ring portion 10 from the outer ring portion side spring portion end 12 a. The longitudinal direction of the spring portion 12 is perpendicular to the direction of the detected load, and the two spring portions 12 are parallel to each other.

The outer ring portion 11 is provided with mounting holes 11a1, 11a2, 11a2 for mounting bolts or the like formed at a plurality of locations (three locations in this example) at equal intervals in the circumferential direction for installation in the fixing member 7; Mounting fixing portions 11 b around the mounting holes 11 a 1, 11 a 2 and 11 a 2 on which a force (for example, a fastening force by a bolt) for installing the motor acts, the outer ring side spring end 12 a and the outer ring side spring end 12 a The first low-rigidity portion 11c configured with the first recess 13a located between the closest installation hole 11a1, the outer ring portion side spring portion end 12a, and the second set installation hole closest to the outer ring portion side spring portion end 12a A second low rigidity portion 11d having a bending rigidity equal to or lower than the first low rigidity portion 11c and a measuring instrument fixing portion 11e which is a mounting portion of the differential transformer coil 9a of the differential transformer 9 are provided between 11a2. The That.

The bending rigidity of the first low rigidity portion 11c is the smallest between the outer ring portion side spring portion end 12a and the mounting hole 11a1 closest to the outer ring portion side spring portion end 12a. Specifically, the thickness in the radial direction of the first low-rigidity portion 11c is the smallest between the outer ring portion side spring portion end 12a and the mounting hole 11a1 closest to the outer ring portion side spring portion end 12a, and further the outer ring portion side A second low rigidity portion 11d is provided between the spring portion end 12a and the second closest installation hole 11a2 such that the radial thickness of the outer ring portion 11 is equal to or less than the thickness of the first low rigidity portion 11c. Here, the bending rigidity means a value obtained by multiplying the Young's modulus E of the material of the outer ring portion 11 and the cross-sectional second moment I in the circumferential direction. When the load detector 5 is installed with a bolt, the installation fixing portion 11b is a range in which the fastening force of the bolt mainly acts. When the load detector 5 is installed on the fixing member 7 with a bolt, assuming that the diameter of the bolt head used for installation is d and the thickness of the holding unit 8 in the Z-axis direction is t, the size of the installation fixing portion 11b is, for example, , And a circle of diameter d + 2t around the mounting hole 11a.

Since the holding unit 8 receives a load in both the + Y direction and the -Y direction depending on the attachment method of the first roll 2a, the second roll 2b, and the third roll 2c to the web 1, the core fixing portion 10b Except for, it is formed in line symmetry with respect to a straight line in the X-axis direction passing through the center A of the inner ring hole 10c.

The differential transformer 9 has a differential transformer core 9 b fixed to the core fixing portion 10 b of the inner ring portion 10 and a differential transformer coil 9 a fixed to the measuring instrument fixing portion 11 e of the outer ring portion 11. The relative displacement of the differential transformer coil 9a and the differential transformer core 9b in the Y-axis direction is measured. In the differential transformer 9, the differential transformer coil 9a and the differential transformer core 9b detect displacement without contact. While a differential transformer uses a contact type sensor as a strain gauge used for strain detection, the differential transformer coil 9a and the differential transformer coil 9b, which are detection points, are noncontact types, so impact and vibration are caused. Etc. has the advantage of being strong against such loads. Also, unlike a strain gage used for strain detection, the differential transformer can be fixed with a bolt or the like, and there is no need to worry about the deterioration of the adhesive, so detection accuracy under temperature and humidity conditions is better than detection with a strain gage. It is easy to secure the long-term reliability of Further, since the differential transformer can easily make the detection output larger than that of the strain gauge, it can be used as a detection device to obtain a load detector that is resistant to disturbances such as electrical noise.

The load detector 5 receives the load F in the Y-axis direction acting from the roll axis 3 via the bearing 4 at the load support portion 10a, and the displacement generated in the core fixing portion 10b by bending the spring portion 12 is measured. It measures with the differential transformer 9 installed in fixed part 11e. In this load detector 5, 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 core fixing portion 10b, so the measurement displacement by the differential transformer 9 is the core fixing portion It can be regarded as displacement of 10b in the Y-axis direction.

Next, the hysteresis that greatly affects the detection performance of the load detector 5 will be described. Hysteresis is a phenomenon in which the detection output of load F differs before and after load F, and the minute displacement of the joint surface that occurs when load F is applied does not completely return after removal of load F. Is the main cause of outbreaks.

As described above, the load detector 5 is often installed using a bolt, but when a slight displacement occurs in the installation fixing portion 11b at the time of load application, it is affected by the frictional force acting on the joint surface of the installation fixing portion 11b. Even after the load is removed, the displacement remains and hysteresis occurs.

The minute displacement of the joint surface generated in the mounting and fixing portion 11b is caused by the bending moment acting on the mounting and fixing portion 11b by the load F in the Y-axis direction, and the distortion occurs in 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 and to reduce the distortion of the outer ring portion 11 generated in the mounting and fixing portion 11b. In particular, as the installation hole closer to the outer ring portion side spring portion end 12a is affected by the bending moment, the strain generated in the installation fixing portion 11b tends to be large. Therefore, the installation fixing portion 11b closest to the outer ring portion side spring portion end 12a It is important to reduce the strain generated in the

In the case where the load detector 5 does not have the recess 13 (the first recess 13a and the second recess 13b), when the load F acts on the load detector, the outer ring portion side spring portion end 12a and the outer ring portion side spring portion end 12a are most On the line connecting the near mounting holes 11a1, distortion larger than the surrounding occurs.

In that point, in the load detector 5 according to the first embodiment, the recess 13 is formed on a line connecting the outer ring portion side spring portion end 12a and the installation hole 11a1 closest to the outer ring portion side spring portion end 12a. By providing the concave portion 13a), the above-mentioned strain can be shut off. 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 spring portion end 12a and the installation hole 11a1 closest to the outer ring portion side spring portion end 12a, The first low rigidity portion 11c is preferentially deformed, and the influence of the bending moment of the installation and fixing portion 11b can be reduced. Therefore, it is possible to reduce the distortion generated in the installation fixing portion 11b closest to the outer ring portion side spring portion end 12a and to reduce the hysteresis.

Further, in the first low rigidity portion 11c in which the thickness in the radial direction of the outer ring portion 11 is smaller than that of the periphery, a large strain locally occurs compared to the other portions of the outer ring portion 11, but the load of the first embodiment In the detector 5, the first low rigidity portion 11c is located at the most distant position from the mounting hole 11a1 between the outer ring portion side spring portion end 12a and the mounting hole 11a1 closest to the outer ring portion side spring portion end 12a. Do. Therefore, it is possible to reduce the influence of the strain locally generated in the first low rigidity portion 11c on the mounting hole 11a1 and the mounting fixing portion 11b in the periphery thereof, thereby reducing the hysteresis.

The bending rigidity of the outer ring portion 11 applied to the second closest installation hole 11a2 from the outer ring portion side spring portion end 12a is not particularly limited, but as in the load detector 5 of the first embodiment, the first low rigidity portion 11c or less If the second low rigidity portion 11d having bending rigidity is provided, the second low rigidity portion 11d is deformed to be larger than the first low rigidity portion 11c, and the influence of the bending moment can be further reduced. As a result, the strain generated in the installation fixing portion 11a1 closest to the outer ring portion side spring portion end 12a is further reduced, leading to further reduction of the hysteresis. Although distortion of the first low rigidity portion 11c or more occurs in the second low rigidity portion 11d, the second low rigidity portion 11d is separated from the second closest installation hole 11a2 from the outer ring portion side spring portion end 12a. If provided, it is possible to reduce the influence of the local strain generated in the second low rigidity portion 11d on the mounting and fixing portion 11b, and to reduce the hysteresis.

Further, the recess 13 not only reduces the hysteresis but also forms a part of the surface of the spring portion 12 by providing the recess 13, so that the spring portion 12 can be elongated without requiring additional processing. Since the spring portion 12 can be made longer, the displacement generated in the core fixing portion 10b can be increased, the detection output can be increased, and a load detector resistant to disturbance can be obtained.

Here, the influence of the length and thickness of the spring portion 12 on the displacement and stress will be described with reference to FIG. FIG. 4 is a cantilever that simulates one spring portion 12 with one end completely fixed and the other end free. The longitudinal direction of the cantilever with no load applied is taken as the X-axis direction, and a load F is applied to the free end in the -Y-axis direction. Assuming that the length of the cantilever in the X-axis direction is L, the thickness in the Y-axis direction is h, and the width in the Z-axis direction is b, the displacement δ at the free end and the maximum stress σ generated on the cantilever are as follows It is expressed by a formula.

δ = 4 FL ³ / (Ebh ³ ) ∝ L ³ / h ³ ··· (2)
σ = 6 FL / (bh ² ) ∝ L / h ² (3)
Here, E is the elastic modulus of the cantilever, and ∝ means proportional. From this, δ / σ, which is the ratio of δ and σ, is expressed by the following equation.

δ / σ = 2L ² / (3Eh) ∝ L ² / h (4)
In order to increase the displacement δ with respect to the stress σ generated in the cantilever beam, δ / σ may be increased. From the equation (4), δ / σ is proportional to the square of the length L and proportional to the power of h, so the stress σ can be obtained by increasing the length L rather than reducing the thickness h. Can effectively increase the displacement δ. That is, in the load detector 5, the displacement can be effectively increased with respect to the stress by increasing the length of the spring portion 12 rather than reducing the thickness of the spring portion 12. That is, it is possible to increase the detection output and obtain a load detector that is resistant to disturbances, while securing the required strength.

In the load detector 5 according to the first embodiment, there are three mounting holes 11a1, 11a2 and 11a2, which are equally arranged in the circumferential direction of the outer ring 11, but the load detector 5 is fixed to the fixing member 7 If possible, the number and position of the mounting holes 11a1, 11a2, 11a2 are not particularly limited.

Further, like the recess 13 (the first recess 13 a and the second recess 13 b) included in the load detector 5 of the first embodiment, the gap between the spring 12 and the inner ring 10 or the spring 12 and the outer ring 11 If the width of the recess 13 is made larger than the width of the gap, the recess 13 can be processed using the same tool as the processing of the gap, so that tool replacement is unnecessary, the processing time is shortened, and the load detector 5 is manufactured. Cost can be reduced.

5 to 7 are enlarged cross-sectional views showing modifications of the first recess 13a of the load detector 5 of the first embodiment. The first recess 13a is not limited to the shape shown in FIG. 3, and may have, for example, the shape shown in FIGS. Specifically, in FIG. 5, the first recess 13 a 1 having a semicircular tip from the inner peripheral side to the outer peripheral side of the outer ring portion 11 is provided in the outer ring portion 11 to form a first low rigidity portion 11 c 1. By making the tip of the first concave portion 13a1 into a semicircular shape, stress concentration of the first low rigidity portion 11c1 can be relaxed. If the width of the first recess 13a1 is increased, the radius of curvature of the tip of the first recess 13a can be increased, so that the stress concentration can be further alleviated. Further, if the curvature radius of the tip is increased, the first low rigidity portion 11c1 which is large in the circumferential direction of the outer ring portion 11 is formed, so the amount of deformation in the first low rigidity portion 11c1 becomes large, and the bending moment is fixed by installation The influence exerted on the portion 11 b can be effectively reduced. Therefore, distortion generated in the mounting fixing portion 11b is reduced, and the hysteresis can be further reduced. FIG. 6 shows the first concave portion 13a2 having a square end, and a portion having a bending rigidity smaller than that of the first low rigidity portion 11c1 of FIG. 5 can be largely provided in the circumferential direction. The first recess 13a3 in FIG. 7 is a circular hole. As long as the roll center 3 can be supported by the inner ring portion 10 via the bearing 4, the first recess 13 a 3 may rest on the inner ring portion 10 as shown in FIG. 7. By putting the first recess 13a3 on the inner ring portion 10, the diameter of the circular hole can be increased. Further, since the first recess 13a3 is a round hole, it can be easily processed by a lathe.

The spring portion 12 is on the opposite side of a straight line B in the Y direction passing the center A of the inner ring hole 10c between the outer ring portion side spring portion end 12a and the inner ring portion side spring portion end 12b. The shape and the number thereof are not particularly limited as long as they cross, but as with the load detector 5 of the first embodiment (including its modification), it passes through the center A of the inner ring hole 10c and against the straight line in the X direction. Assuming that the spring portion 12 is axisymmetric, the spring portion 12 takes symmetrical displacement regardless of the load acting in the ± Y direction, so that the same detection is possible for the load in either positive or negative direction. Become. Further, the inner ring portion side spring portion end 12b is provided at the position of the load support portion 10a farthest away from the outer ring portion side spring portion end 12a in the X-axis direction, and the spring portion 12 and the inner ring portion 10 are joined. Can increase the length of As a result, a large displacement can be secured with respect to the stress, so that the detection output can be increased, and a load detector resistant to disturbance can be obtained. Further, if the longitudinal direction of the spring portion 12 is perpendicular to the detection load, the spring portion 12 is largely bent by the bending moment due to the detection load, and the displacement generated in the inner ring portion 10 can be increased. Further, if the width of the gap between the inner ring portion 10 forming the spring portion 12 and the spring portion 12 and the width of the gap between the outer ring portion 11 and the spring portion 12 are increased, foreign matter can be prevented from clogging the gap. Therefore, the displacement generated in the inner ring portion 10 and the spring portion 12 is not suppressed by the foreign matter, and the reliability of the detection performance is improved.

FIG. 8 is a modification of the load detector 5 according to the first embodiment, and is a cross-sectional view showing the load detector 5 having the stopper 14 which is a mechanism for preventing damage to the spring portion 12. It is an enlarged view which shows the stopper 14 of FIG. The load detector 5 of FIG. 8 enlarges a portion of the outer ring portion 11 of the load detector 5 of FIG. 3 (specifically, the portion facing the inner ring portion side spring portion end 12 b of the spring portion 12) inward. The stopper 14 is provided to reduce the gap between the outer ring portion 11 and the spring portion 12. The other configuration is the same as that of the load detector 5 of FIG.

In the load detector 5 of FIG. 9, by adjusting the size of the gap between the stopper 14 and the inner ring portion side spring portion end 12b of the spring portion 12, the spring with a load equal to or less than the allowable load of the load detector 5 Although the portion 12 does not contact the stopper 14, the outer peripheral surface of the spring portion 12 can be brought into contact with the stopper 14 when a load exceeding an allowable load is applied. Thereby, since deformation of the spring portion 12 is suppressed, damage to the spring portion 12 can be prevented.

If the function of preventing damage to the spring portion 12 is provided, the shape or position of the stopper 14 is not specified, but if the distance between the surface of the stopper 14 and the surface of the spring portion 12 is made constant, the distance Since the contact is made in a region where the spring force 12 is constant (where the spring portion 12 and the outer ring portion 11 have the same shape), the contact area is larger than in the case of the different shape contact. Therefore, the contact stress is reduced, and the deformation and damage of the contact portion can be suppressed.

Further, if the stopper 14 is provided so that the outer ring portion 11 and the spring portion 12 contact each other at a position where the displacement of the spring portion 12 is large as in the vicinity of the inner ring portion side spring portion end 12 b, the stopper 14 and the spring portion 12 The slit width with can be increased. Therefore, the influence of the processing error of the slit width on the load at which the spring portion 12 and the stopper 14 contact is reduced, and the spring portion 12 can be brought into contact with the stopper 14 with a specified load with high accuracy. The location where the stopper 14 contacts is not limited to the spring portion 12, and the deformation of the spring portion 12 may be suppressed by bringing the stopper 14 and the inner ring portion 10 into contact.

Also, adjust the gap between the inner ring portion 10 forming the spring portion 12 and the spring portion 12 and / or the gap between the outer ring portion 11 and the spring portion 12, and adjust the allowable load of the load detector 5. If a portion of the inner ring portion 10 and the spring portion 12 or a portion of the outer ring portion 11 and the spring portion 12 contact with each other when a load exceeding the above is applied, a portion of the outer ring portion 11 as shown in FIG. It is not necessary to separately provide the stopper 14 enlarged inside.

The position and shape of the core fixing portion 10b which is a displacement measurement point is not particularly limited, but in order to increase the displacement generated in the core fixing portion 10b due to the bending of the spring portion 12, the outer ring portion side spring portion 12a It is desirable to provide the core fixing portion 10b and the differential transformer core 9b at the same position.

In the load detector 5 (including its modification) of the first embodiment, the holding unit 8 is composed of a single part, but may be composed of a plurality of parts. For example, the outer ring portion 12 may be separate from the inner ring portion 10 and the spring portion 12, and the thickness of the outer ring portion 11 may be larger than that of the inner ring portion 10 and the spring portion 12.

The material of the holding unit 8 is, for example, iron-based materials such as carbon steel, high tensile steel, rolled steel, stainless steel, structural alloy steel, and plated steel using them as base materials, or aluminum, magnesium, titanium, Materials and alloy materials such as brass and copper may be used.

FIG. 10 is a cross-sectional view of a structure in which the spring portion does not cross the straight line B, which is a modification of the load detector 5 (including its modification) according to the first embodiment.

The outer ring portion side spring portion end 12a and the inner ring portion side spring portion end 12b may be on the same side with respect to a straight line B in the Y direction passing through the center A of the inner ring hole 10c, in other words, the spring portion 12 is a straight line It does not have to cross B. The other structure is the same as that of FIG. By shortening the spring portion 12, the stress generated in the spring portion 12 by the detection load can be reduced, and the strength reliability of the spring portion 12 can be improved.

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

In the load detector 5 of FIG. 3, the load F is detected by measuring the displacement generated in the core fixing portion 10 b using the differential transformer 9, but in this modification, a spring portion is used instead of the differential transformer 9. The strain gauge 16 is attached to 12. The strain gauge 16 is a deformation detection unit that detects the amount of deformation of the spring portion 12 deformed by the load F, that is, the strain of the spring portion 12. The load F is detected based on the amount of deformation measured by the strain gauge 16. The other configuration is the same as the load detector 5 shown in FIG.

In this modification, by using the strain gauge 16 having high detection sensitivity to the deformation of the spring portion 12, the load F can be detected even if the displacement generated in the inner ring portion 10 is reduced. That is, since the bending rigidity of the spring portion 12 can be increased, the inner ring portion 10 can be firmly and stably supported, and the load detector 5 having a high natural frequency can be realized. Further, since the differential transformer 9 is not used, the processing of the core fixing portion 10b of the inner ring portion 10 and the measuring instrument fixing portion 11e of the outer ring portion 11 becomes unnecessary, and the holding unit is compared with the load detector 5 shown in FIG. The structure of 8 can be simplified. The position at which the strain gauge 16 is attached is not particularly limited, but if it is attached in the vicinity of the end of the spring portion 12 of the outer ring portion side spring portion end 12a or the inner ring portion side spring portion end 12b, the detected output is large because the strain is large. it can.

Second Embodiment
12 is a front view showing an example of the spacer 6 used for installation of the load detector 5A of the second embodiment, and FIG. 13 is an installation configuration using the spacer 6 of FIG. 11 of the load detector 5A of the second embodiment. It is a side view showing an example of.

In the second embodiment, the load detector 5A is fixed to the fixing member 7 via the case 15 by sandwiching the front and back of the load detector 5A with the spacer 6 shown in FIG. Thus, both axial end surfaces of the holding unit 8 are covered by the case 15. Also, the case 15 is disposed with a gap between each of the inner ring portion 10 and the spring portion 12.

The spacer 6 plays a role of preventing the inner ring portion 10 and the spring portion 12 from contacting other members such as the fixing member 7 in the installed state, and when the load F acts, deformation of the inner ring portion 10 and the spring portion 12 causes other members to To prevent being blocked by friction with The structure of the spacer 6 is not specified unless the inner ring portion 10 and the spring portion 12 come into contact with other members in the installed state, but as shown in FIG. If only the action portion 6a is enlarged and the connecting portion 6b connecting the force acting portions 6a is reduced, the influence of the contact with the concave portion 11c of the connecting portion 6b or the second low rigidity portion 11d can be reduced. Further, the spacer 6 is not limited to a single part, and the force acting part 6a may not be coupled by the connecting part 6b, and the force acting part 6a may be a plurality of parts.

The case 15 covers the entire surface of the holding unit 8 that is stretched by the X axis and the Y axis except where the roll axis 3 passes, and is attached to the outside of each spacer 6. By providing the case 15, the load detector 5A can be protected from external contact and foreign matter. In addition, if the case 15 is provided with a step or the like so as to contact only the outer ring portion 11 and not contact the inner ring portion 10 and the spring portion 12, the spacer 6 can be omitted. It can improve. Further, if the thickness in the Z-axis direction of the inner ring portion 10 and the spring portion 12 is smaller than that of the outer ring portion 11, contact between the inner ring portion 10 and the spring portion 12 and the case 15 can be prevented without using the spacer 6. Therefore, the spacer 6 can be eliminated and the number of parts can be reduced.

Third Embodiment
FIG. 14 is a cross-sectional view showing a load detector 5B according to Embodiment 3 of the present invention.
In the third embodiment, as shown in FIG. 14, the spring portion 12 is bent at the spring portion forming end 12c. Specifically, the spring portion 12 includes a portion from the inner ring portion side spring portion end 12b of the spring portion 12 to the spring portion forming end 12c, and a recess 13 (a first recess 13a and a second recess 13b) of the spring 12 The extending direction is different in a portion from the spring portion forming end 12c which is a portion corresponding to the opening end to the outer ring portion side spring portion end 12a. The portion of the spring portion 12 from the spring portion forming end 12c to the outer ring portion side spring portion end 12a is an outer ring portion side spring portion end with respect to the nearest installation hole 11a1 with the recess portion 13 with the spring portion forming end 12c as a base point. It is bent and formed so that 12a may separate. A first low rigidity portion 11c is formed in the outer ring portion 11 by the first recess 13a, and a first low rigidity portion 11c is formed between the outer ring portion side spring portion end 12a and the mounting hole 11a1 closest to the outer ring portion side spring portion end 12a. The bending rigidity of the low rigidity portion 11c is the smallest. Further, in the outer ring portion 11, a second low rigidity portion 11d is formed by the second concave portion 13b, and between the outer ring portion side spring portion end 12a and the installation hole 11a2 closest to the outer ring portion side spring portion end 12a. The second low rigidity portion 11 d has a bending rigidity equal to or less than the first low rigidity portion 11 c. The other configuration is the same as the load detector 5 shown in FIG.

With the above-described structure, the outer ring portion side spring portion end 12a can be separated from the mounting hole 11a1 closest to the spring portion forming end 12c. Therefore, distortion generated in the mounting hole 11a1 can be reduced and hysteresis can be reduced. In addition, by changing the position where the recess 13 is provided in the outer ring portion 11, the thickness of the portion of the spring portion 12 from the spring portion forming end 12c to the outer ring portion side spring portion end 12a can be easily adjusted. The stress generated at the spring end 12a can be easily reduced. The bending rigidity of the outer ring portion 11 applied to the second closest installation hole 11a2 from the outer ring portion side spring portion end 12a is not particularly limited, but the bending rigidity of the first low rigidity portion 11c or less as in the load detector 5B of FIG. If the second low rigidity portion 11d is provided, the second low rigidity portion 11d is deformed more than the first low rigidity portion 11c. Thereby, the distortion generated in the installation fixing portion 11b1 closest to the outer ring portion side spring portion end 12a can be further reduced, and the hysteresis can be further reduced. Further, the shape of the recess 13 is not particularly limited. Moreover, although the load detector 5 of FIG. 14 is not provided with a stopper, for example, as in the load detector 5 of FIG. 9, a stopper may be provided by bringing a part of the outer ring portion close to the spring portion 12 .

Embodiment 4
FIG. 15 is a cross-sectional view showing a load detector 5C according to Embodiment 4 of the present invention, and FIG. 16 is an enlarged view showing the stopper of FIG.
In the load detector 5C according to the fourth embodiment, like the load detector 5B according to the third embodiment (FIG. 14), the portion from the inner ring portion side spring portion end 12b of the spring portion 12 to the spring portion forming end 12c The spring portion forming end 12c to the outer ring portion side spring portion end 12a are bent at the spring portion forming end 12c, and the extending direction is different.

Further, in the load detector 5C of the fourth embodiment, the spring portion 12 is partially formed in a circular arc shape from the spring portion forming end 12c to the inner ring portion side spring portion end 12b. Embodiment 1 to 3 Like the load detectors 5 to 5B (including the modified example), the difference is that they are not formed linearly from the spring portion forming end 12c to the inner ring portion side spring portion end 12b.

Specifically, the load detector 5C includes an elongated hole 17a forming an outer surface of the spring portion 12, an elongated hole 17b forming an outer surface of the inner ring portion 11 and an inner surface of the spring portion 12, and the differential transformer 9 And a differential transformer attachment hole 17c for attaching the Among these, since the long hole 17a and the long hole 17b are partially formed in an arc shape, a part of the spring portion 12 configured by the long hole 17a and the long hole 17b is also formed in an arc shape. There is. The long hole 17a and the long hole 17b are connected to the differential transformer attachment hole 17 by a slit.

The spring portion 12 is coupled to the inner ring portion 10 at the inner ring portion spring portion end 12b provided at the position of the load support portion 10a farthest away from the outer ring portion side spring portion end 12a in the X-axis direction. It is formed in parallel with the X-axis direction from the end portion 12b to a point where the Y-direction straight line B passing through the spring portion 12 and the center A of the inner ring hole 10c intersects.

In the spring portion 12, the portion from the spring portion forming end 12c to the outer ring portion side spring portion end 12a is a direction in which the outer ring portion side spring portion end 12a separates from the installation hole 11a1 closest to the spring portion forming end 12c. It is formed of the first recess 13a and the longitudinal end of the elongated hole 17a having a width in the radial direction. The radial width of the long hole 17a and the long hole 17b and the circumferential width of the first recess 13a are equal. The other configuration is the same as the load detector 5 shown in FIG.

The load detector 5C can increase the length of the spring portion 12 by providing the inner ring portion side spring portion end 12b at a position most distant from the outer ring portion side spring portion end 12a in the X-axis direction. In addition, by forming a part of the spring portion 12 in an arc shape, the length of the inner ring portion 10 can be increased because the length of the spring portion 12 can be made longer than straight. That is, the detection output can be increased, and a load detector 5C resistant to disturbance can be obtained. In addition, at a portion where the longitudinal direction of the spring portion 12 is perpendicular to the load direction, the spring portion 12 is effectively bent by the bending moment by the load, and the displacement of the inner ring portion 10 can be obtained.

In addition, since a part of the elongated hole has an arc shape, when the elongated hole 17a and the elongated hole 17b are processed, the moving distance of the tool can be made smaller than the linear movement. In particular, by making the center of the arc shape of the long hole 17b coincident with the center A of the inner ring hole 10c, the moving distance of the processing tool can be reduced while securing the space of the inner ring hole 10c into which the bearing 4 is inserted. Since the processing time of the

long holes

17a and 17b can be shortened, the manufacturing cost of the load detector 5C can be reduced. Further, one surface of the spring portion 12 applied from the spring portion forming end 12c to the outer ring portion side spring portion end 12a is formed at a longitudinal end of the elongated hole 17a having a width in the radial direction. No other processing is required. Therefore, the moving distance of the tool can be reduced, leading to cost reduction of the load detector 5C. In addition, since the spring portion 12 is bent at the spring portion forming end 12c, the outer ring portion side spring portion end 12a can be separated from the mounting hole 11a1 closest to the spring portion forming end 12c, so strain generated in the mounting hole 11a1 Can be reduced to reduce the hysteresis.

The width of the long hole 17a and the long hole 17b in the radial direction and the width of the first recess 13a are not particularly limited, but as in the load detector 5C of the fourth embodiment, the width of the long hole 17a and the long hole 17b in the radial direction If the width of the first concave portion 13a is equalized, machining can be similarly performed with the same tool, so that tool replacement is not necessary. Therefore, processing time can be shortened and the cost of the load detector 5C can be reduced. Further, if the radial width of the elongated holes 17a and the elongated holes 17b is increased, foreign matter is generated between the inner ring portion 10 and the spring portion 12 forming the spring portion 12 and between the outer ring portion 11 and the spring portion 12. It is hard to get stuck. Therefore, the displacement generated in the inner ring portion 10 and the spring portion 12 is not suppressed by the foreign matter, and the reliability of the detection performance is improved.

By adjusting the size of the slit connecting the long hole 17a and the differential transformer attachment hole 17c, the spring portion 12 does not contact the outer ring portion 11 with a load less than the allowable load of the load detector 5C, but the allowable load The outer peripheral surface of the spring portion 12 can be brought into contact with the outer ring portion 11 when a load exceeding the above acts. Thereby, since deformation of the spring portion 12 is suppressed, damage to the spring portion 12 can be prevented.

Although the position of the slit connecting the long hole 17a and the differential transformer attachment hole 17c is not specified, if the slit is provided on a straight line connecting the center A of the inner ring hole 10c and the installation hole 11a, the width and length of the long hole 17a Even if the length is increased, securing of the installation fixing portion 11b is facilitated. In addition, if the slit is provided in the vicinity of the inner ring portion side spring portion end 12c where the displacement of the spring portion 12 becomes large, the width of the slit can be increased. Therefore, the influence of the processing error of the width of the slit on the load that the outer ring portion 11 and the spring portion 12 contact with each other is reduced, and the spring portion 12 can be brought into contact with the outer ring portion 11 with high accuracy.

The bending rigidity of the outer ring portion 11 applied to the second closest installation hole 11a2 from the outer ring portion side spring portion end 12a is not particularly limited, but as in the load detector 5C of FIG. If the radial thickness of the outer ring portion 11 applied to the second closest installation hole 11a2 from the outer ring portion side spring portion end 12a is reduced by 17a, the second low rigidity portion has a bending rigidity equal to or less than the first low rigidity portion 11c. 11 d can be provided in a wide range with respect to the outer ring portion 11. By providing the second low rigidity portion 11d in a wide range, the amount of deformation of the second low rigidity portion 11d becomes large, which leads to a further reduction of the influence of the bending moment due to the detected load. That is, it is possible to reduce the distortion generated in the mounting fixing portion 11b and to further reduce the hysteresis. In the case where the first recess 13a is not provided by providing the first recess 13a in order to increase the length of the spring portion and reduce the hysteresis as in the load detector 5C of FIG. The hysteresis is reduced to about 0.6 times with respect to. Furthermore, the first concave portion 13a is provided by providing the second low rigidity portion 11d having a bending rigidity smaller than that of the first low rigidity portion 11c between the second lower mounting portion 11a2 and the second outer ring portion side spring portion end 12a. It has been measured that the hysteresis can be reduced to about 0.4 times as compared to the case where no such phenomenon occurs.

FIG. 17 is a cross-sectional view showing a modification of the first recess of FIG. The size of the first recess 13a is not particularly limited, but the length of the spring portion 12 can be further increased by enlarging the first recess 13a in the radial direction as in the load detector 5C of FIG. The bending rigidity of the low rigidity portion 11c may be reduced to reduce the hysteresis.

FIG. 18 is a cross-sectional view showing a load detector using a plurality of displacement detectors, which is a modification of the load detector of FIG. The number of displacement detectors 9 for detecting displacement is not specified. For example, as shown in FIG. 18, the core fixing portion 10b is provided on a straight line C in the X direction passing through the center A of the inner ring hole 10c,
The two displacement detectors 9 may be attached so as to be line symmetrical with respect to the straight line C. By using the sum of the absolute values of the outputs of the displacement detectors 9 or the average of the absolute values of the outputs as the output of the load detector, a load detector that is more resistant to disturbances can be obtained. Also, a displacement detection unit and a deformation detection unit such as a strain gauge may be used in combination.

FIG. 19 is a cross-sectional view showing a modification of the load detector of FIG. 15 and which is installed with four mounting holes. The position and the number of the mounting holes 11a are not particularly limited, and a load detector 5C as shown in FIG. 19 may be used.

The load detector 5C in FIG. 19 has mounting holes 11a1, 11a1, 11a2 at positions symmetrical with respect to a straight line B in the Y direction passing through the center A of the inner ring hole 10c and a straight line C passing in the X direction. , 11a2 are provided four. In this load detector 5C, in order to provide the outer ring portion side spring portion end 12a at a position separated from the mounting hole 11a1, the spring portion 12 has a circular arc shape and extends to the vicinity of the straight line C. A spring portion forming end 12c which is a bending point of In the outer ring portion 11, a first low rigidity portion 11c is formed between the outer ring portion side spring portion end 12a and the installation hole 11a1 closest to the outer ring portion side spring portion end 12a, and the outer ring portion side spring portion end 12a A second low rigidity portion 11d is provided between the outer ring portion side spring portion end 12a and the second closest installation hole 11a2. The bending stiffness of the first low rigidity portion 11c is the smallest between the outer ring portion side spring portion end 12a and the installation hole 11a1 closest to the outer ring portion side spring portion end 12a. The bending rigidity of the second low rigidity portion 11 d is not particularly limited, but it is desirable that the bending rigidity is equal to or less than the bending rigidity of the first low rigidity portion 11 c.

In the load detector 5C, the load detector 5C can be firmly mounted on the fixing member 7 by increasing the mounting holes 11a1 and 11a2. Further, by increasing the number of the mounting holes 11a1 and 11a, the necessary fastening force can be secured, so a bolt with a small diameter may be used, and the diameter of the mounting hole 11a can be reduced. Further, since the outer ring portion side spring portion end 12a is provided in the vicinity of the straight line C, the spring portion 12 can be made long and the detection output can be increased.

In addition, since the installation hole 11a can be separated from the outer ring portion side spring end 12a by reducing the installation hole, the distortion of the installation fixing portion 11b can be reduced and the hysteresis can be easily reduced.

Fifth Embodiment
FIG. 20 is a cross-sectional view showing a load detector 5D according to Embodiment 5 of the present invention.
In this load detector 5D, two spring portions 12 linearly extending in the radial direction from the inner ring portion 10 to the outer ring portion 11 are provided on the same side with respect to the straight line C in the X direction passing through the center A of the inner ring hole 10c. The two spring portions 12 are symmetrical with respect to a straight line B in the Y direction passing through the center A of the inner ring hole 10c. The spring portion 12 forms an angle θs with the straight line C (X axis), and a part of the surface of the spring portion 12 is formed by the first concave portion 13a. Further, the bending rigidity of the first low rigidity portion 11c formed in the outer ring portion 11 by the first recess portion 13a is between the outer ring portion side spring portion end 12a and the mounting hole 11a1 closest to the outer ring portion side spring portion end 12a. It is smaller than the bending rigidity of the outer ring portion 11 in the above. The bending rigidity of the outer ring portion 11 between the outer ring portion side spring portion end 12a and the mounting hole 11a2 which is the second closest to the outer ring portion side spring portion end 12a is not particularly limited, but the bending rigidity of the first low rigidity portion 11c or less It is desirable to provide a second low rigidity portion 11 d having Although the positions and the number of the mounting holes 11a1 and 11a2 are not specified, in this example, three positions are provided at equal intervals in the circumferential direction of the outer ring portion 11, and the mounting holes 11a1 are on the straight line B. Although there is no particular limitation on the mounting position of differential transformer 9, in this load detector 5D, from the viewpoint of securing mounting space for differential transformer 9, the opposite side to spring portion 12 with respect to straight line C and on straight line B The core fixing portion 10b is provided to attach the differential transformer core 9b. The other configuration is the same as the load detector 5 shown in FIG.

The spring portion 12 is not particularly limited as long as it is line symmetrical with respect to the straight line B.

By making the spring portion 12 line-symmetrical with respect to the straight line B, the trajectory of displacement of the inner ring portion 10 does not become arc-shaped, but becomes a straight line parallel to the load direction (Y-axis direction). A load detector with good linearity can be obtained. Further, in the tension detector 5D of FIG. 20, the distance between the mounting hole 11a and the outer ring portion side spring portion end 12a can be easily adjusted by changing the angle θs.

Incidentally, the linearity is an index representing the magnitude of deviation of the measured value from an ideal straight line where the output of the differential transformer (displacement of the inner ring portion 10) is proportional to the detected load.

In the load detectors 5 to 5D (including the variations thereof) of the above-described embodiments, the web 1 has been described as an object to be applied to the rolls 2a to 2c, but a wire such as a cable may be used.

Further, the configuration of the web 1 and the rolls 2a to 2c is not specified, and for example, the web 1 may be attached in the reverse direction to the rolls 2a to 2c.

If the roll 2a can be supported, only one end of the roll axis 3 is supported by the load detectors 5 to 5D (including its modification), and the other end is not supported, and the free end is supported. You may

Further, although the load detectors 5 to 5D (including the modified example) are fixed to the fixing member 7 using the bolt which is a fastening member, this is an example and may be a fastening member such as a screw. In that case, the installation and fixing portion 11b is a portion to which a force for fixing the load detectors 5 to 5D (including the modification thereof) to the fixing member 7 acts. Furthermore, the strain gauge may be applied not only to the first embodiment but also to the spring portion 12 of the second to fifth embodiments.

DESCRIPTION OF SYMBOLS 1 web (detection object), 2a, 2b, 2c roll, 3 roll axial center, 4 bearing, 5, 5A, 5B, 5C, 5D load detector, 6 spacer, 6a force acting part, 6b connecting part, 7 fixing member , 8 holding unit, 9 differential transformer (displacement detection unit), 9a differential transformer coil, 9b differential transformer core, 10 inner ring portion, 10a load support portion, 10b core fixing portion, 10c inner ring hole, 11 outer ring portion, 11a1 , 11a2 mounting hole, 11b mounting fixing portion, 11c first low rigidity portion, 11d second low rigidity portion, 11e measuring device fixing portion, 12 spring portion, 12a outer ring portion side spring portion end, 12b inner ring portion side spring portion end, 12c Spring forming end, 13 recesses, 13a first recesses, 13b second recesses, 14 stoppers, 15 cases, 16 strain gauges, 17a, 7b slot, 17c differential transformer mounting holes.

Claims

An inner ring portion holding a shaft supporting a load, an outer ring portion fastened to a mounting member by a fastening member through a plurality of mounting holes provided surrounding the inner ring portion and formed at intervals in the circumferential direction, and the inner ring portion A holding unit having a plurality of spring portions connecting the outer ring portion;
A displacement detection unit that detects displacement of the inner ring portion caused by the load;
A recess which is formed on the outer ring portion side spring portion end which is an end on the outer ring portion side of the spring portion, and which constitutes the spring portion;
Load detector with.
An inner ring portion holding a shaft supporting a load, an outer ring portion fastened to a mounting member by a fastening member through a plurality of mounting holes provided surrounding the inner ring portion and formed at intervals in the circumferential direction, and the inner ring portion A holding unit having a plurality of spring portions connecting the outer ring portion;
A deformation detection unit that detects a deformation amount of the spring unit that is deformed by the load;
A recess which is formed on the outer ring portion side spring portion end which is an end on the outer ring portion side of the spring portion, and which constitutes the spring portion;
Load detector with.
The recess is constituted by a first recess which constitutes one surface which is one surface of the spring portion, and a second recess which constitutes the other surface which is the surface opposite to the one surface of the spring portion. The load detector according to item 1 or 2.
The concave portion is constituted by a first concave portion constituting one surface which is one surface of the spring portion, and an elongated hole which constitutes the other surface which is a surface opposite to the one surface of the spring portion. The load detector according to 1 or 2.
The other portion of the outer ring portion is formed between the outer ring portion side spring portion end and the installation hole closest to the outer ring portion side spring portion end among the plurality of installation holes, which is formed by the first concave portion in the outer ring portion. The load detector according to claim 3 or 4, further comprising a first low rigidity portion having a bending rigidity smaller than that of the first low rigidity portion.
The first low rigidity is formed in the outer ring portion by the second recessed portion, and between the outer ring portion side spring portion end and the installation hole closest to the outer ring portion side spring portion end of the plurality of installation holes. The load detector according to claim 5, wherein a second low rigidity portion having a bending rigidity equal to or less than a portion is provided.
The first low rigidity portion is formed by the elongated hole in the outer ring portion, and between the outer ring portion side spring portion end and the installation hole closest to the outer ring portion side spring portion end of the plurality of installation holes. The load detector according to claim 5 provided with the 2nd low rigidity part which has the following bending rigidity.
The load detector according to any one of claims 1 to 7, wherein the spring portion is formed to pass through the center of the inner ring portion and to cross a straight line parallel to a load direction which is a load application direction.
A portion of the spring portion from the outer ring portion side spring portion end to the spring portion forming end corresponding to the opening end of the recess is a plurality of the spring portions starting from the spring portion forming end. The load detector according to any one of claims 1 to 8, wherein the load detector is bent so as to be separated from the mounting hole closest to the outer ring side spring portion end of the mounting hole.
The spring portion and the inner ring portion are connected at a position where the distance in the direction perpendicular to the load direction, which is the direction in which the load acts from the outer ring portion side spring portion end, is the largest. The load detector according to any one of the preceding claims.
In the spring portion, a portion from the spring portion forming end corresponding to the opening end of the recess in the spring portion to the inner ring portion side spring portion end as the end on the inner ring portion is formed in a straight line The load detector according to any one of the preceding claims.
The load detector according to any one of claims 1 to 11, wherein at least a part of the spring portion is formed in a direction perpendicular to a load direction which is a direction in which the load acts. .
The load detector according to any one of claims 1 to 12, wherein at least a part of the spring portion is formed in an arc shape.
At least two of the radial width of the gap between the spring portion and the outer ring portion, the radial width of the gap between the spring portion and the inner ring portion, and the circumferential width of the recess are The load detector according to any one of claims 1 to 13, which is formed to have the same width.
The spring portion is disposed so as to be axisymmetric with respect to a straight line which passes through the center of the inner ring portion and is perpendicular to a load direction which is a direction in which a load acts. The load detector according to any one of the preceding claims.
The displacement detection unit is a differential transformer provided with a differential transformer coil fixed to the outer ring portion and a differential transformer core fixed to the inner ring portion and displaced relative to the differential transformer coil. The load detector according to any one of claims 3 to 15, wherein a certain claim 1 and a claim 1 are cited.