TWI613139B - Load detector - Google Patents

Abstract

A load detector includes: a holding unit including: an inner ring portion holding a shaft for supporting a load; and a plurality of mounting holes formed by surrounding the inner ring portion and being formed at intervals in a circumferential direction by a locking member And fixed to the outer ring portion of the mounting member; and an elastic portion connected to the outer ring portion with an elastic portion end extending radially outward from the inner ring portion; and a displacement detection portion that detects the inner ring generated by the load The displacement of the part. The peripheral edge portion of the mounting hole has a mounting fixing portion, that is, a joint surface of the locking member with the outer ring portion. The outer ring portion has a low rigidity portion formed between the mounting hole and the end of the elastic portion, and the bending rigidity in the circumferential direction of the low rigidity portion is lower than the bending rigidity of other portions of the outer ring portion.

Description

Load detector

The present invention relates to a load detector suitable for a tension detector, which detects the tension of a roll of paper, cloth, film, metal foil, or the like, or a wire such as a cable.

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.

A load detector is used to detect the load acting on the drum. However, if the natural frequency of the load detector is low, the above-mentioned processing process cannot be speeded up due to the vibration caused by the transfer of the coil. Therefore, a load detector with a high natural frequency is preferred. For example, a load detector is known in which an elastic body that bears a load is set as a one-sided support beam, and the neutral axis of the bending moment of the one-sided support beam is slightly aligned with the center of the load, thereby increasing the natural frequency of the load detector. (For example, refer to Patent Document 1).

[Prior technical literature] [Patent Literature]

Patent Document 1: Japanese Patent Laid-Open Publication No. 3-246433 (Figure 2)

Although the above-mentioned load detector can increase the natural frequency of the load detector itself, it does not consider the influence of the load detector on the installation performance of the mounting member to the detection performance.

As for the detection performance having a large influence due to the mounting, for example, an increase in the hysteresis of the detection performance and a decrease in the natural frequency accompanying the increase in the hysteresis can be mentioned.

The present invention was developed by the inventor to solve the above-mentioned problems, and an object thereof is to provide a load detector with a high natural frequency, easy installation of a mounting member, and low hysteresis.

The load detector of the present invention includes: a holding unit including an inner ring portion holding a shaft for supporting a load; the inner ring portion is provided to surround the inner ring portion, and a plurality of lock ring members are formed through the circumferential direction with an interval therebetween. The mounting portion is locked to the outer ring portion of the mounting member; the elastic portion connected to the outer ring portion with an elastic portion end extending radially outward from the inner ring portion; and the displacement detecting portion detects the load due to the load The displacement of the aforementioned inner ring portion; the peripheral edge portion of the mounting hole has a mounting fixing portion, that is, the aforementioned lock The joint surface of the fixed member to the outer ring portion; the outer ring portion is formed between the mounting hole and the end of the elastic portion, and a low rigidity portion is formed; The bending rigidity of other parts.

According to the load detector of the present invention, a low rigidity portion is formed between the mounting hole of the outer ring portion and the end of the elastic portion, and the bending rigidity in the circumferential direction of the low rigidity portion is compared with the bending rigidity of other portions of the outer ring portion The lower is lower, and it can provide a load detector structure with high natural frequency, easy installation, and low hysteresis in detection performance. Therefore, it has a significant effect of further improving the detection accuracy of the load detector and expanding the scope of application of the detector.

1‧‧‧ roll material (detection object)

2a, 2b, 2c‧‧‧ roller

3‧‧‧Drum axis

4‧‧‧bearing

5‧‧‧Load Detector

6‧‧‧ spacer

7‧‧‧Mounting 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

11a‧‧‧Mounting holes

11b‧‧‧Mounting and fixing part

11c‧‧‧Low rigidity

11d‧‧‧Tester fixing part

11e‧‧‧Outer ring recess

11f‧‧‧ flat

11g‧‧‧Side

12‧‧‧ Elastic Section

12a‧‧‧Flexible end

12b‧‧‧ flat

12c‧‧‧side

13a‧‧‧stop

13b‧‧‧ Outer ring inner peripheral surface

14‧‧‧ Strain gauge (deformation detection section)

15‧‧‧shell

A‧‧‧ Center

B, C, D, P, Q, R, S‧‧‧ points

F‧‧‧Load

T‧‧‧ tension

W‧‧‧ Weight

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

Figure 2 is a sectional view taken along the arrow II-II of Figure 1.

Figure 3 is a front view of the load detector of Figure 1.

Fig. 4 is a perspective view showing the holding unit of Fig. 1.

FIG. 5 is an enlarged front view showing a modified example of the low-rigidity portion in FIG. 3.

FIG. 6 is an enlarged front view showing a modified example of the low-rigidity portion in FIG. 3.

FIG. 7 is an enlarged front view showing a modified example of the low-rigidity portion in FIG. 3.

FIG. 8 is an enlarged front view showing a modified example of the low-rigidity portion in FIG. 3.

Fig. 9 is an enlarged front view showing a modified example of the low-rigidity portion of Fig. 3;

FIG. 10 is an enlarged front view showing a modified example of the low-rigidity portion in FIG. 3.

FIG. 11 shows a modification of the load detector of FIG. 1 and a front view of the load detector including a mechanism for preventing damage to the elastic portion.

Fig. 12 is an enlarged view showing a mechanism for preventing damage to the elastic portion of Fig. 11.

Fig. 13 shows a modification of the load detector shown in Fig. 3, and shows a front view of the load detector having a different structure of the elastic portion.

Fig. 14 shows a modification of the load detector shown in Fig. 3, and shows a front view of the load detector having a different structure of the elastic portion.

Fig. 15 shows a modification of the load detector shown in Fig. 3, and shows a front view of the load detector having a different detection structure.

FIG. 16 is a front view showing a spacer for mounting the load detector of FIG. 1. FIG.

Fig. 17 is a side view showing a mounting structure of a load detector using the spacer of Fig. 16;

Fig. 18 is a front view of the load detector of Fig. 1 composed of a plurality of parts.

Fig. 19 is an exploded front view showing the load detector of Fig. 18.

FIG. 20 is a front view of a load detector according to a second embodiment of the present invention; Illustration.

Fig. 21 is an enlarged view showing the elastic portion of Fig. 20.

Fig. 22 is a front view of a load detector according to a third embodiment of the present invention.

Fig. 23 is an explanatory diagram illustrating a bending moment acting on the load detector of Fig. 22;

FIG. 24 is an explanatory diagram illustrating a bending moment acting on the load detector of FIG. 22.

Fig. 25 is a front view showing a load detector according to a fourth embodiment of the present invention.

Fig. 26 is a front view showing a load detector according to a fifth embodiment of the present invention.

Hereinafter, the load detectors according to the embodiments of the present invention will be described based on the drawings. However, the same or equivalent components and parts in each drawing are denoted by the same reference numerals for explanation.

Implementation type 1

FIG. 1 is a diagram showing a mounting structure of a load detector 5 according to a first embodiment of the present invention. FIG. 2 is a cross-sectional view of an arrow along a line II-II in FIG. A front view of the load detector 5, and FIG. 4 is a perspective view showing the holding unit 8 of FIG.

The X-axis direction in FIG. 1 is set to the width direction of the load detector 5, the Y-axis direction is set to the high direction of the load detector 5, and the Z-axis direction is set to the depth direction of the load detector 5. The same symbols are used in the figure number. The load detected by the load detector 5 acts in the -Y direction.

The load detector 5 according to this embodiment is fixed to the mounting member 7 and detects a load F acting in the Y-axis direction of the load detector 5 via the drum axis 3.

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) / 2cos θ (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.

The roll 1 of the detection target such as paper, cloth, film, metal foil is wound around the first roll 2a, the second roll 2b, and the 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. A load detector 5 is mounted on each bearing 4 and mounted on the mounting member 7.

The load detector 5 includes a holding unit 8 that receives a load F from the drum axis 3 in the Y-axis direction, and a differential transformer 9 that is a displacement detecting unit that measures the displacement of the components of the holding unit 8 due to the load F. .

The holding unit 8 includes: an inner ring portion 10 which is fitted in the bearing 4 and receives a load from the drum shaft center 3; and an outer ring portion 11 which is formed in an annular shape fixed to the mounting member 7 on the outside of the inner ring portion 10 And an elastic portion 12 extending radially in two places to connect the inner ring portion 10 and the outer ring portion 11.

The inner ring portion 10 includes a ring-shaped load support portion 10 a and an iron core fixing portion 10 b extending from the load support portion 10 a in the X-axis direction.

The outer ring portion 11 includes: mounting holes 11a formed at three equally spaced intervals for mounting of bolts and the like fixed to the mounting member 7; and a mounting fixing portion 11b located 1 mm to 10 mm from the periphery of the mounting hole 11a. The range; the low rigidity portion 11 c is formed between the elastic portion ends 12 a of the connecting portion of the outer ring portion 11 and the elastic portion 12; and the measuring device fixing portion 11 d is a planar shape in which the differential transformer 9 is provided. The low-rigidity portion 11c reduces the radial thickness of the outer ring portion 11 by a notch. That is, the radial thickness of the low-rigidity portion 11 c is smaller than the radial thickness of the other portions of the outer ring portion 11. Thereby, compared with the other parts of the outer ring part 11, the bending rigidity of the low rigidity part 11c in a circumferential direction is low.

The flexural rigidity herein refers to a value obtained by multiplying the Young's coefficient E of the material of the outer ring portion 11 by the quadratic moment of inertia (also referred to as area moment of inertia) I in the circumferential direction.

The holding unit 8 is connected to the inner ring portion 10 and the outer ring portion 11 by an elastic portion 12 extending in a radial direction from the load supporting portion 10a. In order to withstand the first roll 2a, the second roll 2b, and the third roll according to the roll 1 In the installation method of 2c, the load in either of the + Y direction and the -Y direction is a line-symmetric shape with respect to a straight line passing through the load F center A in the X-axis direction, except for the iron core fixing portion 10b. The center of the inner ring hole 10c in which the inner ring portion 10 of the bearing 4 is mounted coincides with the load center A.

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 11d of the outer ring portion 11 to measure the differential change The relative displacement in the Y-axis direction between the voltage transformer coil 9a and the differential transformer core 9b.

The load detector 5 receives the load F in the Y-axis direction acting from the drum axis 3 via the bearing 4 through the bearing 4 through the bearing support portion 10a, and measures the bending of the elastic portion 12 with the differential transformer 9 provided on the measuring device fixed portion 11d. The displacement generated in the iron core fixing portion 10b.

In this load detector 5, since the displacement of the measuring instrument fixing portion 11d to which the differential transformer coil 9a is fixed is much smaller than the displacement of the coil fixing portion 10b, the measured displacement of the differential transformer 9 can be regarded as the Y axis of the iron core fixing portion 10b. Directional 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 the load F is different before and after the loading of the load F. The main cause of the hysteresis is the slight deviation of the joint surface generated when the load F is loaded, and the load F has not completely recovered to its original state.

As described above, the mounting of the load detector 5 usually uses bolts. However, if there is a slight deviation in the joint surface of the mounting and fixing portion 11b under load, the frictional force acting on the joint surface of the mounting and fixing portion 11b After the load is removed, the offset is maintained and the hysteresis occurs.

The slight offset generated in the mounting and fixing portion 11b is due to the bending moment acting on the mounting and fixing portion 11b due to the load F in the Y-axis direction. Therefore, in order to reduce the hysteresis, it is important to reduce the bending moment acting on the mounting and fixing portion 11b.

In the load detector 5 of the implementation form 1, the bending moment from the load supporting portion 10a to the elastic portion end 12a due to the load F in the Y-axis direction has low rigidity. The portion 11c occurs at the mounting and fixing portion 11b. However, since the bending rigidity of the low rigidity portion 11c is smaller than that of the other portions of the outer ring portion 11, the low rigidity portion 11c is deformed first, thereby reducing the bending acting on the mounting and fixing portion 11b. Moment.

Therefore, it is possible to reduce the displacement of the joint surface generated in the mounting and fixing portion 11b and reduce the hysteresis.

In addition, since the displacement of the joint surface such as bolt locking can be reduced, the load detector 5 having a high natural frequency can be manufactured.

In the load detector 5 shown in FIG. 3, there are three mounting holes 11a, which are evenly arranged in the circumferential direction of the outer ring portion 11. However, if the load detector 5 can be fixed to the mounting member 7, the mounting holes 11a There are no particular restrictions on the number and location of

The low-rigidity portion 11c is not limited to the shape shown in FIG. 5 but may have a shape as shown in FIGS. 6 to 10. FIG. 5 is a quadrangular notch provided in the outer ring portion 11 from the inner peripheral side or the outer peripheral side of the outer ring portion 11 so as to reduce the width of the outer periphery of the outer ring portion and reduce the bending rigidity compared to other parts of the outer ring portion. small. Fig. 6 shows a part of the notch in Fig. 5 as an arc-shaped low-rigidity portion. Fig. 7 shows a low-rigidity portion formed by providing a round hole at the tip of a slit, and the stress at the tip of the slit is relieved by the round hole. concentrated. FIG. 8 is a low-rigidity portion formed by providing a circular hole in the outer ring portion 11, and the processing cost can be reduced because only the hole-forming processing is performed. FIG. 9 is a low rigidity portion formed by providing a cutout in the outer ring portion 11 from the inner peripheral side and the outer peripheral side of the outer ring portion 11, and FIG. 10 is a low rigidity portion formed by providing a plurality of slits.

In addition, the low-rigidity portion 11c can be made thinner in the Z-axis direction.

If the bending rigidity in the circumferential direction of the low-rigidity portion 11c is lower than that of the outer ring portion 11, Other parts are small, and there are no particular restrictions on their number, shape, etc.

In manufacturing, as shown in FIG. 3, the bending rigidity can be effectively reduced by reducing the width of the outer periphery of the outer ring portion 11 corresponding to the low rigidity portion.

In addition, the inventors of the present application have experimentally learned that when the bending rigidity in the circumferential direction of the outer ring portion 11 of the low-rigidity portion 11c is 1/8 or less relative to the bending rigidity of other portions of the outer ring portion 11, the load detection can be significantly improved. Device 5 hysteresis. For example, when the bending rigidity in the circumferential direction of the low-rigidity portion 11 c is 1/8 of the bending rigidity of the other portions of the outer ring portion 11, the hysteresis is about half of the case where no low-rigidity portion is provided in the outer ring portion 11.

FIG. 11 shows a modified example of the load detector 5 of FIG. 1 and a front view of the load detector 5 including a stopper 13 a as a mechanism for preventing the elastic portion 12 from being damaged. FIG. 12 shows a stop of FIG. 11. Enlarged view of piece 13a.

The stopper 13 a has a base end portion fixed to the outer ring portion 11. The front end portion of the stopper 13 a is directed toward the load center A and faces the outer peripheral surface of the inner ring portion 10, and a gap is formed with the inner ring portion 10.

The other components are the same as those of the load detector 5 shown in FIG. 3.

In this load detector 5, when the load is less than the allowable load of the load detector 5, the load supporting portion 10a does not contact the stopper 13a, but when a load exceeding the allowable load acts, the outer periphery of the load supporting portion 10a contacts the stopper. The member 13 a suppresses deformation of the elastic portion 12, thereby preventing damage to the elastic portion 12.

The material and shape of the stopper 13a are not particularly limited if it has a function of preventing the elastic portion 12 from being damaged. For example, if a bolt such as a captive screw is used As the stopper 13a, the clearance between the front end of the stopper 13a and the outer periphery of the load supporting portion 10a can be easily adjusted.

FIGS. 13 and 14 are modified examples of the load detector 5 of FIG. 3 and are front views of the load detector 5 having different structures of the elastic portion 12.

If the elastic portion 12 of the implementation form 1 is a structure capable of generating a non-destructive displacement required to detect the bending of the elastic portion 12 due to the bending moment generated by the load F in the Y-axis direction, the core fixing portion 10 b of the inner ring 10 can be detected. , The shape, number of branches, symmetry, etc. are not particularly limited.

The example in FIG. 13 has two elastic portions 12 connecting the outer ring portion 11 and the inner ring portion 10 in parallel. With the truss structure, the displacement variation of the core fixing portion 10b is approximately parallel to the load direction, so the load can be detected. The linearity is good.

The example in FIG. 14 has an elastic portion 12 connecting one of the outer ring portion 11 and the inner ring portion 10. The elastic portion 12 is more likely to be bent due to the bending moment acting on the elastic portion 12 due to the load F in the Y-axis direction. The displacement of the iron core fixing portion 10b can be increased.

Therefore, the detection output is increased, and the load detector 5 that is not easily affected by external interference can be realized.

If the elastic portion 12 has a line-symmetric structure with respect to a straight line passing through the X-axis direction of the load center A, even if the direction of the load F is reversed, the iron core fixing portion 10b has the same displacement change before and after the reversal. Load detector 5 with good symmetry in load detection.

In addition, the bending moment generated at the elastic portion end 12a due to the load F is proportional to the distance in the X-axis direction from the load center A, so if the elasticity When the portion 12 is located at a position that increases the distance in the X-axis direction from the load center A, the bending of the elastic portion 12 increases, and the displacement of the core fixing portion 10b can be increased.

Therefore, the detection output is increased, and the load detector 5 that is not easily affected by external interference can be realized.

The position and shape of the fixing portion 10b belonging to the displacement measurement portion are not particularly limited, but in order to increase the displacement generated in the core fixing portion 10b due to the bending of the elastic portion 12, the core fixing portion 10b and the differential transformer iron The core 9b is preferably provided at a position away from the elastic portion end 12a in the X-axis direction.

FIG. 15 is a front view showing another detection structure of the load detector 5 according to the first embodiment.

The load detector 5 in FIG. 3 uses a differential transformer 9 to measure the displacement generated in the iron core fixing portion 10 b and detects the load F. However, this variation is based on attaching a strain gauge 14 to the elastic portion 12 instead of the differential transformer. 9. The strain gauge 14 is a deformation detection unit that detects a deformation amount of the elastic portion 12 deformed by the load F, that is, a strain amount of the elastic portion 12. The load F is detected based on the amount of deformation measured by the strain gauge 14.

The other structure is the same as that of the load detector 5 shown in FIG.

In this modification, since the strain gage 14 having high sensitivity in detecting the deformation of the elastic portion 12 is used, the load F can be detected even if the displacement generated in the inner ring portion 10 is small. That is, the bending rigidity of the elastic portion 12 can be increased, the inner ring portion 10 can be stably supported, and the load detector 5 having a high natural frequency can be realized.

In addition, if the differential transformer 9 is deleted, it is not necessary to perform the inner ring section 10 separately. Compared with the load detector 5 shown in FIG. 3, the processing of the fixed fixing portion 10b of the iron core fixing portion 10b and the measuring fixing portion 11d of the outer ring portion 11 can be simplified.

FIG. 16 is a front view showing the spacer 6 used for mounting the load detector 5 of FIG. 1, and FIG. 17 is a side view showing a mounting structure of the load detector 5 using the spacer 6 of FIG. 16.

In this example, the front and back surfaces of the load detector 5 are sandwiched by spacers 6 as shown in FIG. 16, and the load detector 5 is fixed to the mounting member 7 via the housing 15. Thereby, both end surfaces of the holding unit 8 in the axial direction are covered by the case 15. In addition, the housing 15 is disposed 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 body 12 from contacting other members such as the mounting member 7 in a mounted state to prevent the deformation of the inner ring portion 10 and the elastic body 12 from being affected by the load F. Interference caused by friction with other components.

In addition, as long as the inner ring portion 10 and the elastic portion 12 do not contact other members in the mounted state, the structure of the spacer 6 is not particularly limited.

In addition to the portion through which the roller shaft center 3 passes, the casing 15 covering the entire surface of the X-axis and the Y-axis of the holding unit 8 is attached to each of the spacers 6 as shown in FIG. 17. On the outside, the load detector 5 is isolated from dust, contact, and the like from the outside.

In addition, if the housing 15 has a structure that contacts only the outer ring portion 11 and does not contact the inner ring portion 10 and the elastic portion 12, the spacer 6 is not required, thereby improving workability due to a reduction in the number of parts.

The thickness of the inner ring portion 10 and the elastic portion 12 in the Z-axis direction is increased. When the degree is smaller than the outer ring portion 11 to prevent contact, the spacer 6 may not be needed.

Fig. 18 is a front view showing the load detector 5 of Fig. 1 composed of a plurality of parts. Fig. 19 is an exploded front view showing the load detector 5 of Fig. 18.

The holding unit 8 shown in FIG. 3 is constituted by a single part, however, in this example, it is constituted by a plurality of parts.

The load detector 5 is a separate component of the outer ring portion 11, the inner ring portion 10 and the elastic portion 12. As shown in FIG. 19, the outer ring portion 11 and the elastic portion 12 are aligned with the flat portion 12b of the elastic portion end 12a and the flat portion 11f of the outer ring recessed portion 11e and fixed with bolts or the like.

If the fixing between the outer ring portion 11 and the elastic portion 12 is possible, the fixing method is not particularly limited.

If the side surface 12c of the elastic portion end 12a and the side surface 11g of the outer ring recessed portion 11e are fitted, the position of the elastic portion 12 can be aligned, and the fixing position of the elastic portion 12 can be easily determined.

Even if a single part with a complicated structure is divided into a plurality of parts, the structure of the divided part can be simplified, and it can be manufactured by extrusion molding and punching to reduce manufacturing costs.

In addition, the structure in which the Z-axis thickness of the inner ring portion 10 and the elastic portion 12 is smaller than that of the outer ring portion 11 can be easily produced by extrusion molding. This eliminates the need for the spacer 6 for mounting, and thus contributes to reduction in the number of parts and workability. In addition, by increasing the width of the annular recessed portion 11e provided outside the fixed elastic portion end 12a, not only the fixed elastic portion end 12a, but also a structure including the low rigidity portion 11c.

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.

The holding unit 8 shown in FIG. 18 is a simple shape that is extruded in the Z-axis direction. Therefore, it can be extruded. Especially when an aluminum alloy is used, the production efficiency can be improved. Lightweight.

Implementation type 2

FIG. 20 is a front view of the load detector 5 according to the embodiment 2 of the present invention, and FIG. 21 is an enlarged view of the elastic portion 12 of FIG. 20.

As shown in FIG. 20, the load detector 5 of the second embodiment is provided with two L-shaped elastic portions 12 symmetrical to a straight line passing through the load center A in the X-axis direction. The elastic portion 12 extends radially outward from the outer peripheral portion of the load supporting portion 10 a, is bent at a point B of the bending point of the elastic portion 12, is L-shaped, and is connected to the outer ring portion 11. A gap is formed between the elastic portion 12 and the outer ring inner peripheral surface 13 b in the radial direction of the outer ring portion 11. Thereby, the interval between the outer ring inner peripheral surface 13b of the outer ring portion 11 and the surface of the elastic portion 12 facing the outer ring inner peripheral surface 13b between the outer ring portion 11 and the elastic portion 12 is constant. region.

The other components are the same as those of the load detector 5 shown in FIG. 3.

According to the load detector 5 of this embodiment, the bending moment generated by the elastic portion 12 due to the load F in the Y-axis direction is proportional to the distance in the X-axis direction from the load center A. Therefore, if the distance is larger, Then, a large bending moment acts on the bending point B of the elastic portion 12 and deforms the elastic portion 12.

As the distance a in the X-axis direction of the load center A and the point B of the bending point of the elastic portion 12 is increased, the displacement generated in the core fixing portion 10b is increased, and the differential transformer 9 installed in the core fixing portion 10b is detected. The output is increased, and a load detector 5 that is less susceptible to external interference can be obtained.

In addition, when the size of the gap between the elastic portion 12 and the outer ring inner peripheral portion 13b is adjusted to a load equal to or lower than the allowable load of the load detector 5, the elastic portion 12 does not contact the outer ring inner peripheral surface 13b and exceeds the allowable amount. When the load acts on the load, the elastic portion 12 contacts the outer ring inner peripheral portion 13b, thereby suppressing the deformation of the elastic portion 12 when the load exceeds the allowable load, and preventing the elastic portion 12 from being damaged.

Therefore, as shown in FIG. 12, it is not necessary to separately provide a stopper 13 a for preventing damage to the elastic portion 12, and the number of parts of the load detector 5 can be reduced to improve assembly workability.

In addition, as shown in FIG. 20, the outer ring inner peripheral surface 13 b of the outer ring portion 11 and the surface of the elastic portion 12 facing the outer ring inner peripheral surface 13 b have a constant interval.

Therefore, when a load exceeding the allowable load is applied to the load detector 5, the contact area is larger in a contact area than a contact between dissimilar shapes because the contact is made in a region having a constant interval. Therefore, the contact stress is reduced, and damage to the contact portion can be suppressed.

Implementation type 3

Fig. 22 is a front view of the load detector 5 according to the third embodiment of the present invention.

The load detector 5 of the embodiment 3 is an outer ring portion 11 and an inner ring portion 10 and the elastic portion 12 are separate parts, and have two L-shaped elastic portions 12 structure.

The elastic portion 12 extends radially outward from the outer peripheral portion of the load supporting portion 10 a, is bent at a point B of the bending point of the elastic portion 12, is L-shaped, and is connected to the outer ring portion 11.

The elastic portion end 12 a is provided at a position where the distance b between the flat portion 12 b of the elastic portion 12 and the load center A in the X-axis direction is small. The elastic portion end 12 a is fitted into the outer ring recess 11 e and fixed with a bolt or the like to constitute the holding unit 8.

If the fixing between the outer ring portion 11 and the elastic portion 12 is possible, the fixing method is not particularly limited. As for the position of the elastic portion end 12a, when the distance b between the flat portion 12b of the elastic portion end 12a and the load center A in the X-axis direction is small, the load F in the Y-axis direction acts on the bending of the elastic portion end 12a. The torque becomes smaller and better.

In addition, in the load detector 5 shown in FIG. 22, the outer ring recessed portion 11e of the fixed elastic portion end 12a is enlarged to provide not only the fixed elastic portion end 12a, but also the outer ring recessed portion 11e with a low rigidity portion 11c.

In addition, the outer ring portion 11 and the elastic portion 12 have a structure in which a gap is formed between the outer ring inner peripheral surface 13 b and the elastic portion 12 in the radial direction of the outer ring portion 11 in a fixed state. The clearance is when a load exceeding the allowable load acts, and the elastic portion 12 contacts the outer ring inner peripheral portion 13b to suppress deformation of the elastic portion 12, thereby having a function of preventing damage to the elastic portion. The center of the inner ring hole 10c in which the inner ring portion 10 of the bearing 4 is mounted coincides with the load center A.

According to the load detector 5 in FIG. 22, although the bending moment at the point B acting on the elastic portion 12 due to the load F in the Y-axis direction can be increased, However, by reducing the distance b between the flat portion 12b of the elastic portion 12 and the load center A in the X-axis direction, the bending moment acting on the elastic portion end 12a can be reduced.

That is, as the bending of the elastic portion 12 becomes larger, the displacement generated in the iron core fixing portion 10b can be increased, and the displacement of the joint surface between the elastic portion end 12a and the outer ring recessed portion 11e can be reduced, which can be reduced. It is smaller than the hysteresis generated between the elastic portion 12 and the mounting and fixing portion 11 b of the outer ring portion 11. In particular, when the distance b is 0, the bending moment acting on the end 12a of the elastic portion is minimized, so that the hysteresis is minimized. In addition, since the displacement of the joint surface can be reduced, the natural frequency of the load detector 5 can be increased.

Next, using FIGS. 23 and 24 illustrating the bending moment acting on the elastic portion end 12a, the bending moment of the outer ring recessed portion 11e can be reduced by reducing the distance b.

The tie beam shown in FIG. 23 extends along the X-axis direction and the Y-axis direction. A load W in the -Y direction is applied to the point P, and the point S is completely fixed.

FIG. 24 is a beam obtained by rotating the beam of FIG. 23 counterclockwise by θ. As in FIG. 23, a load W in the −Y direction is applied to the point P, and the point S is completely fixed.

The points P, Q, R, and S of the beams of FIGS. 23 and 24 correspond to points D, C, B, and the elastic end 12a of FIG. 22, respectively.

Point C is the junction between the load support portion 10a and the elastic portion 12, and point D is the intersection of the straight line passing through the load center A in the Y-axis direction and the load support portion 10a. The bending moment M generated by the load F at the point S in FIGS. 23 and 24 is expressed by the following formula.

M = F (L1-L2) (2)

From this, it can be seen that the bending moment acting on the point S corresponding to the end 12a of the elastic portion is not related to the angle of the beam, but is proportional to the distance (L1-L2) from the point P to the point S in the direction perpendicular to the direction of the load. When the torque system distance (L1-L2) is zero, it becomes the minimum.

In addition, the holding unit 8 of the load detector 5 of the embodiment 2 shown in FIG. 20 has a long and thin gap between the inner peripheral surface 13b of the outer ring and the elastic portion 12, and has a complicated structure. In the load detector 5 shown in this embodiment, since the outer ring portion 11, the inner ring portion 10, and the elastic portion 12 of each component constituting the holding unit 8 have a simple structure, they can be formed by extrusion or punching. The manufacturing cost can be suppressed by manufacturing such as processing.

In addition, if the thickness in the Z-axis direction of the inner ring portion 10 and the elastic portion 12 is smaller than the thickness of the outer ring portion 11, in the mounted state, the inner ring portion 10 and the elastic portion 12 are not connected to other members such as the mounting member 7 Since the contact is made, the deformation of the inner ring portion 10 and the elastic portion 12 is not affected by interference due to friction with other members, and the spacer 6 is not required.

In addition, the two elastic portions 12 have a structure in which a line is symmetrical to a straight line passing through the X-axis direction of the load center A as shown in FIG. 22, and even if the direction of the load F is reversed, the core fixing portion 10b is reversed before and after the reverse. For the same displacement variation, a load detector 5 with good symmetry in load detection can be realized.

Implementation type 4

Fig. 25 is a front view of the load detector 5 according to the fourth embodiment of the present invention.

In the load detector 5 of the fourth embodiment, the two elastic portions 12 are arranged to connect the inner ring portion 10 and the outer ring portion 11, and the line is symmetrical to the passing load. A straight line in the Y axis direction of the center A.

The pair of elastic portions 12 are bent by a bending moment caused by a load F in the Y-axis direction, and the displacement generated in the core fixing portion 10b is measured by a differential transformer 9 provided in the measuring device fixing portion 11d.

The iron core fixing portion 10 b and the differential transformer 9 are provided on a straight line passing through the load center A in the direction of symmetry of the elastic portion 12. If the elastic portion 12 is line-symmetric to a straight line passing through the Y-axis direction of the load center A, the structure, the number of supports, and the like are not particularly limited.

In the load detector 5 shown in the implementation modes 1 to 3, when the elastic portion 12 is deformed by the bending moment caused by the load F in the Y-axis direction, the core fixing portion 10b at the displacement measurement position is arc-shaped. Therefore, compared with the case where the displacement is linear, the linearity of the displacement measured with respect to the load is reduced.

In contrast, in the load detector 5 shown in FIG. 25, the elastic portion 12 is a line symmetrical to a straight line passing through the Y-axis direction of the load center A. When the load F acts, the iron core fixing portion 10b takes a straight line. Because of this, the linearity of the measurement displacement is good, and the detection accuracy of the load can be improved.

In addition, the holding unit 8 according to the fourth embodiment may be composed of a plurality of parts instead of a single part.

Implementation type 5

Fig. 26 is a front view of the load detector 5 according to the fifth embodiment of the present invention.

The load detector 5 of this embodiment 5 is shown in FIG. 26. The outer ring portion 11, the inner ring portion 10, and the elastic portion 12 are separate parts, and are provided with points. The structure of two L-shaped elastic portions 12 symmetrical to the load center A.

The elastic portion 12 according to the fifth embodiment has the same mechanism as that of the elastic portion 12 according to the third embodiment shown in FIG. 22 except that the point is symmetrical to the load center A.

According to the load detector 5 of the fifth embodiment, similarly to the load detector 5 of the fourth embodiment, when the load F in the Y-axis direction acts on the load support portion 10a, the core fixing portion 10b changes linearly. Therefore, the linearity of the measured displacement is better than that of the circular arc, and the detection accuracy of the load can be improved.

In addition, the elastic portion 12 takes a larger distance a in the X-axis direction from the load center A and the point B of the elastic portion 12 to increase the bending moment acting on the point B of the elastic portion 12. The distance b in the X-axis direction between the flat portion 12b of the elastic portion 12 and the load center A reduces the bending moment acting on the elastic portion end 12a.

Therefore, the displacement generated in the core fixing portion 10b can be increased, and the hysteresis caused by the displacement of the joint surface between the elastic portion end 12a and the outer ring recessed portion 11e can be reduced.

In addition, since the displacement of the joint surface between the elastic portion end 12a and the outer ring recessed portion 11e can be reduced, the natural frequency of the load detector 5 can be increased.

In addition, the structure in which the pair of elastic portions 12 of the implementation type 5 are 12 points symmetrical to the load center A, so that even if the direction of the load F is reversed, the core fixing portion 10b has the same displacement before and after the reverse. The load detector with good symmetry can be realized.

In addition, the holding unit 8 according to the fifth embodiment may have a single component structure.

In the load detector 5 of each of the above embodiments, the object to be wound around the rollers 2a to 2c is described using the coil 1 as an example, 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. For example, the roll material 1 may be installed in the reverse direction to the rollers 2a to 2c.

In addition, if the drum 2a can be supported, it is not necessary to support the load detector 5 with only one end of the drum shaft center 3, and the other end becomes a free end without supporting the load detector 5.

In addition, a bolt is used as a fixing member for fixing the mounting member 7 of the load detector 5. However, this is only an example, and a locking member such as a screw may be used. At this time, the mounting and fixing portion 11 b becomes a portion where a force for fixing the load detector 5 to the mounting member 7 is applied. It should be noted that the strain gauge 14 is applicable not only to the first embodiment but also to the elastic portion 12 of the second to fifth embodiments.

5‧‧‧Load Detector

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

11a‧‧‧Mounting holes

11b‧‧‧Mounting and fixing part

11c‧‧‧Low rigidity

11d‧‧‧Tester fixing part

12‧‧‧ Elastic Section

12a‧‧‧Flexible end

Claims (13)

A load detector includes: a holding unit including: an inner ring portion holding a shaft for supporting a load; and a plurality of mounting holes formed by surrounding the inner ring portion and being formed at intervals in a circumferential direction by a locking member And is fixed to the outer ring portion of the mounting member; and an elastic portion connected to the outer ring portion with an elastic portion end extending radially outward from the inner ring portion; and a displacement detection portion that detects the occurrence of the load The displacement of the inner ring portion; the peripheral edge portion of the mounting hole has a mounting and fixing portion, that is, the joint surface of the locking member to the outer ring portion; the outer ring portion is between the mounting hole and the end of the elastic portion A low rigidity portion is formed therebetween, and the bending rigidity in the circumferential direction of the low rigidity portion is lower than the bending rigidity of other portions of the outer ring portion. A load detector includes: a holding unit including: an inner ring portion holding a shaft for supporting a load; and a plurality of mounting holes formed by surrounding the inner ring portion and being formed at intervals in a circumferential direction by a locking member And fixed to the outer ring portion of the mounting member; and an elastic portion connected to the outer ring portion with an elastic portion end extending radially outward from the inner ring portion; and a deformation detection portion that detects deformation due to the load The deformation amount of the elastic portion; the peripheral edge portion of the mounting hole has a mounting and fixing portion, that is, a joint surface of the locking member with the outer ring portion; The outer ring portion has a low rigidity portion formed between the mounting hole and the end of the elastic portion, and the bending rigidity in the circumferential direction of the low rigidity portion is lower than the bending rigidity of other portions of the outer ring portion. The load detector according to item 1 of the scope of patent application, wherein the outer ring portion is a different part from the elastic portion and the inner ring portion. The load detector according to item 2 of the scope of patent application, wherein the outer ring portion is a different part from the elastic portion and the inner ring portion. The load detector according to any one of claims 1 to 4, wherein the elastic portion is provided with two or more pieces, and each of the elastic portions is linearly symmetrical with and perpendicular to the center of the inner ring portion. Placed in the direction of the load line. The load detector according to any one of claims 1 to 4, wherein the elastic portion is provided with two or more branches, and each of the elastic portions is linearly symmetric to pass through the center of the inner ring portion and along the Configure the way of the line extending in the load direction. The load detector according to any one of claims 1 to 4, wherein the elastic portion is provided with two or more branches, and each of the elastic portions is point-symmetrical to the center of the inner ring portion with the elastic portion. Way configuration. The load detector according to any one of claims 1 to 4, wherein the elastic portion passes through a bending point from the inner ring portion and is connected to the outer ring portion by the elastic portion end. Before passing For a distance in which the straight line in the load direction of the center of the inner ring portion is a vertical direction, the distance from the straight line to the bending point is greater than the distance from the straight line to the end of the elastic portion. The load detector according to item 8 of the scope of patent application, wherein the interval between the inner peripheral surface of the outer ring having the outer ring portion and the surface of the elastic portion opposite to the inner peripheral surface of the outer ring is fixed. region. The load detector according to any one of claims 1 to 4, which includes a stopper, the base end portion of which is fixed to the aforementioned outer ring portion, and the front end portion facing each other with a gap therebetween. Toward the outer peripheral surface of the inner ring portion. The load detector according to any one of claims 1, 3, and 4, wherein the displacement detecting section is a differential transformer, and the differential transformer is provided with a differential transformer fixed to the outer ring section. A coil; and a differential transformer core fixed to the inner ring portion and performing relative displacement on the differential transformer coil. The load detector according to any one of claims 1 to 4, wherein the radial thickness of the low-rigidity portion is smaller than the radial thickness of other portions of the outer ring portion. The load detector according to any one of claims 1 to 4, wherein the axial end surfaces of the holding unit are covered with a housing, and the housing is connected to each of the inner ring portion and the elastic portion. Arranged across a gap.