JP2023118445A - Thin-thickness cylindrical sleeve and torque sensor - Google Patents

Abstract

To maintain joining at a joining side in the case that tension in a peripheral direction acts.SOLUTION: In a thin-thickness cylindrical sleeve 30 in which a thin plate 38 is formed by being bent into a cylindrical shape, joining sides 40 are joined to each other by welding by a plurality of weld parts 50 with both-side end parts of the thin plate 38 in a peripheral direction as the joining sides 40, and into which a stub shaft 87 is pressure-inserted, a shape of a fitment boundary which appears at the both-side joining sides 40 of the thin plate 38 is formed such that folded parts 45 being portions which are inverted in orientations of boundaries by axially folding back are arranged at the joining sides 40, respectively, the folded part 45 of the other joining side 40 is located and joined between one portion of one joining side 40 located in a peripheral direction from the folded part 45 of one joining side 40 and the folded part 45 of one joining side 40, and the weld parts 50 are located in a position in which compression stress is generated at the joining sides 40 when the stub shaft 87 is pressure-inserted into the thin-thickness cylindrical sleeve 30.SELECTED DRAWING: Figure 8

Description

The present disclosure relates to thin-walled cylindrical sleeves and torque sensors.

A torque sensor for detecting torque applied to a rotating body is attached to the rotating body and detects torque by detecting angular displacement in the direction of rotation of the rotating body when rotational torque acts on the rotating body. is possible. For example, in the torque sensor described in Patent Literature 1, a rotor disk to be detected by a detection circuit is attached to a shaft member by a sleeve that is a cylindrical support structure. This allows the torque sensor to detect the angular displacement in the direction of rotation of the shaft member, which is a rotating body, via the rotor disk by means of the detection circuit, thereby detecting the torque acting on the shaft member.

EP-A-2383558

Various methods are conceivable for manufacturing a thin cylindrical sleeve such as a sleeve attached to a shaft member that is a rotating body. A conceivable method is to roll a substantially rectangular thin plate into a cylindrical shape, join the butted portions by laser welding, and form a cylindrical shape. In the torque sensor, the thin cylindrical sleeve is arranged at a desired position on the shaft member by press-fitting the shaft member into the thin cylindrical sleeve formed in this way.

However, when manufacturing by welding and joining butt portions of thin plates rolled into a cylindrical shape, if the strength of the welded portion is low, when the shaft member is press-fitted into the thin-walled cylindrical sleeve, it acts on the thin-plate cylinder at the time of press-fitting. Circumferential tensile stress can cause the weld to break. If the welded portion breaks, the joined portion of the thin cylindrical sleeve comes off, making it impossible to fix the thin cylindrical sleeve to the shaft member. For this reason, there is room for improvement from the viewpoint of maintaining the joints at the joint sides, which are the sides that are joined to each other at both ends of the thin plates, when welding is performed to manufacture a thin cylindrical sleeve.

The present disclosure has been made in view of the above, and an object thereof is to provide a thin-walled cylindrical sleeve and a torque sensor that are capable of maintaining joints at joint edges when tension is applied in the circumferential direction.

The thin cylindrical sleeve of the present disclosure is formed by bending a thin plate into a cylindrical shape, and the joint sides are welded with a plurality of welds using the ends of the thin plate on both sides in the circumferential direction of the cylinder as joint sides. In the thin cylindrical sleeve into which the shaft member is press-fitted, the shape of the fitting boundary appearing on the joint sides on both sides of the thin plate is folded back in the axial direction of the cylinder. each of the joint sides has a folded portion that is a portion in which the directions are opposite to each other, is located at a position in the circumferential direction from the folded portion of one of the joint sides, and is part of one of the joint sides; The folded portion of the other joint side is positioned between and joined to the folded portion of the one joint side, and the welded portion is formed when the shaft member is press-fitted into the thin cylindrical sleeve. It is located at a position where compressive stress is generated on the joint side.

According to this configuration, the welded portion is located at a position where compressive stress is generated at the joint sides when the shaft member is press-fitted into the thin cylindrical sleeve that welds the joint sides of the thin cylindrical sleeves. As a result, even if a force in the circumferential direction is applied to the thin cylindrical sleeve by press-fitting the shaft member into the thin cylindrical sleeve, it is possible to suppress the generation of tensile stress in the welded portion, and the tensile stress causes the welded portion to break. can be suppressed. As a result, it is possible to maintain the joint at the joint side when tension in the circumferential direction is applied.

Desirably, the welded portion is located at the folded portion.

According to this configuration, since the welded portion is positioned at the folded portion, when a force acts on the thin cylindrical sleeve in a direction in which the joint sides are separated from each other in the circumferential direction, compressive stress is generated in the welded portion. . Therefore, even if a force in the circumferential direction is applied to the thin cylindrical sleeve by press-fitting the shaft member into the thin cylindrical sleeve, it is possible to suppress breakage of the welded portion due to tensile stress. As a result, it is possible to maintain the joint at the joint side when tension in the circumferential direction is applied.

As a desirable form, the folded portion has a portion having an inclination angle of 45° or less in the circumferential direction with respect to the axial direction.

According to this configuration, since the angle of inclination of the folded portion in the circumferential direction with respect to the axial direction of the thin cylindrical sleeve is 45° or less, it is possible to suppress the occurrence of a shearing force between the opposing folded portions. It is possible to suppress the occurrence of shear stress and tensile stress in the welded portion located in the region. Therefore, even when a force in the circumferential direction acts on the thin cylindrical sleeve due to the shaft member being press-fitted into the thin cylindrical sleeve, it is possible to prevent the welded portion from breaking due to shear stress or tensile stress. As a result, it is possible to maintain the joint at the joint side when tension in the circumferential direction is applied.

As a desirable form, the joint sides to be joined to each other include a convex side joint side and a concave side joint side, and the convex side joint side is the concave side joint side in a state of being joined to the concave side joint side. has a convex portion that protrudes in a direction approaching the convex portion, and the concave portion side joint side is formed to be concave in a direction away from the convex portion side joint side in a state of being joined to the convex portion side joint side, and the convex portion It has a concave portion into which the convex portion enters when it is joined to the side joint side, and the convex portion and the concave portion are separated when a force is applied in a direction in which the joint sides separate from each other while the convex portion is in the concave portion. has a portion where compressive stress is generated.

According to this configuration, the joint sides to be joined to each other are composed of the convex side joint side having the convex portion and the concave side joint side having the concave portion. There is a portion where compressive stress is generated when a force is applied in the direction in which the joint sides are separated from each other. The welded portion joining the joint sides is applied at a position where a compressive stress is generated in the convex portion and the concave portion. As a result, even if a force in the circumferential direction is applied to the thin cylindrical sleeve by press-fitting the shaft member into the thin cylindrical sleeve, it is possible to suppress the generation of tensile stress in the welded portion, and the tensile stress causes the welded portion to break. can be suppressed. As a result, it is possible to maintain the joint at the joint side when tension in the circumferential direction is applied.

As a desirable form, the convex portion is formed to have a portion whose width in the axial direction is larger than the width in the axial direction at the base of the convex portion, and the joint side of the convex portion is , in the convex portion, the folded portion between the base portion of the convex portion and a portion formed to have a width larger than the width in the axial direction at the position of the base of the convex portion; is formed, the recess is formed to have a portion whose width in the axial direction is larger than the width in the axial direction at the position of the opening of the recess, and the joint side on the recess side is the The folded portion is formed between the opening of the recess and a portion formed with a width larger than the width in the axial direction at the position of the opening.

According to this configuration, when the convex portion enters the concave portion and the joint side of the convex portion and the joint side of the concave portion are joined together, the folded portion on the convex portion side and the folded portion on the concave portion side face each other. Therefore, when a force acts on the thin cylindrical sleeve in a direction in which the joint sides are separated from each other in the circumferential direction, the folded portion on the protruding portion side and the folded portion on the recessed portion side restrict the movement of the other in the circumferential direction. Therefore, it is possible to suppress the projection from coming out of the recess, and it is possible to suppress the joint sides from being separated from each other in the circumferential direction. As a result, it is possible to maintain the joint at the joint side when tension in the circumferential direction is applied.

The torque sensor of the present disclosure includes a shaft member that transmits rotational torque, a thin cylindrical sleeve that is formed in a substantially cylindrical shape and into which the shaft member is press-fitted, and a detection member that is arranged around the thin cylindrical sleeve. and an arithmetic element that detects the rotational torque based on a change in inductance of a detection coil that detects movement of the detection member in the circumferential direction about the shaft member, and the thin cylindrical sleeve has a thin plate with a cylindrical shape. It is formed by bending into a shape and is joined by welding the joint sides with a plurality of welding parts using ends on both sides of the thin plate in the circumferential direction of the cylinder as joint sides. In the shape of the fitting boundary appearing on the joint side, each of the joint sides has a folded portion, which is a portion in which the direction of the boundary is reversed by being folded back in the axial direction of the cylinder, and at a position in the circumferential direction from the folded portion of the joint side of and between a part of one joint side and the folded portion of one joint side, the folded portion of the other joint side The welded portion is located at a position where compressive stress is generated at the joint side when the shaft member is press-fitted into the thin cylindrical sleeve.

According to this configuration, the welded portion is located at a position where compressive stress is generated at the joint sides when the shaft member is press-fitted into the thin cylindrical sleeve that welds the joint sides of the thin cylindrical sleeves. As a result, even if a force in the circumferential direction is applied to the thin cylindrical sleeve by press-fitting the shaft member into the thin cylindrical sleeve, it is possible to suppress the generation of tensile stress in the welded portion, and the tensile stress causes the welded portion to break. can be suppressed. As a result, it is possible to maintain the joint at the joint side when tension in the circumferential direction is applied.

The thin-walled cylindrical sleeve and the torque sensor according to the present disclosure have the effect of being able to maintain the joint at the joint edge when tension in the circumferential direction is applied.

FIG. 1 is a schematic diagram of a steering device according to an embodiment. FIG. 2 is a perspective view of a main portion of the steering device according to the embodiment. FIG. 3 is a perspective view of the torque sensor, stub shaft and pinion gear. 4 is a perspective view of a main part of the constituent members of the torque sensor shown in FIG. 3. FIG. FIG. 5 is an explanatory diagram showing a state where the input side rotor is attached to the stub shaft. 6 is a perspective view of a thin-walled cylindrical sleeve included in the input-side rotor shown in FIG. 5. FIG. 7 is a plan view of a thin plate used to manufacture the thin cylindrical sleeve shown in FIG. 6. FIG. FIG. 8 is a detailed view of part C in FIG. FIG. 9 is a detailed view of part D in FIG. FIG. 10 is a cross-sectional view showing a state where the input side rotor is attached to the stub shaft. FIG. 11 is an explanatory diagram showing a case where a welded portion is located at a position where tensile stress is generated. FIG. 12 is a modification of the thin cylindrical sleeve according to the embodiment, and is an explanatory diagram showing a form in which a set of protrusions and recesses are formed on the joint side. FIG. 13 is a modification of the thin cylindrical sleeve according to the embodiment, and is an explanatory view showing a form in which the projection and the recess are respectively formed in a trapezoidal shape. FIG. 14 is a modification of the thin-walled cylindrical sleeve according to the embodiment, and is an explanatory view showing a configuration in which each of the convex portion and the concave portion is formed in a T shape. FIG. 15 is a modification of the thin-walled cylindrical sleeve according to the embodiment, and is an explanatory view showing a configuration in which the joint side does not have a convex portion and a concave portion and a folded portion is formed.

Hereinafter, the present disclosure will be described in detail with reference to the drawings. The present disclosure is not limited by the following modes for carrying out the invention (hereinafter referred to as embodiments). In addition, components in the following embodiments include those that can be easily assumed by those skilled in the art, those that are substantially the same, and those that fall within a so-called equivalent range. Furthermore, the constituent elements disclosed in the following embodiments can be combined as appropriate.

[Embodiment]
FIG. 1 is a schematic diagram of a steering device 80 according to an embodiment. As shown in FIG. 1, the steering device 80 includes a steering wheel 81, a steering shaft 82, a universal joint 84, a lower shaft 85, a universal joint 86, and a stub shaft in order of transmission of force given by the operator. 87 , a steering gear 88 and tie rods 89 . The steering device 80 also includes a control device (hereinafter referred to as an ECU (Electronic Control Unit)) 90 , a torque sensor 10 and an electric motor 92 . A vehicle speed sensor 91 is provided in the vehicle and outputs a vehicle speed signal V to the ECU 90 through CAN (Controller Area Network) communication.

The steering shaft 82 is connected at one end to the steering wheel 81 and at the other end to a universal joint 84 .

The lower shaft 85 is connected at one end to the universal joint 84 and at the other end to the universal joint 86 . The stub shaft 87 has one end connected to the universal joint 86 and the other end connected to the torque sensor 10 . The torque sensor 10 has one end connected to the stub shaft 87 and the other end connected to the pinion gear 88 a of the steering gear 88 .

Specifically, the stub shaft 87 and the pinion gear 88a are connected via a torsion bar (not shown). The torsion bar has one end connected to the stub shaft 87 and the other end connected to the pinion gear 88a, and the torsion bar transmits rotational torque between the stub shaft 87 and the pinion gear 88a. Torque sensor 10 detects rotational torque transmitted between stub shaft 87 and pinion gear 88a via a torsion bar.

The steering gear 88 includes a pinion gear 88a and a rack bar 88b. The pinion gear 88a is connected to the stub shaft 87 via a torsion bar. One end of the pinion gear 88a is connected to the torque sensor 10, and the driving force of the electric motor 92 can be transmitted from the other end. The rack bar 88b meshes with the pinion gear 88a. The steering gear 88 converts the rotary motion transmitted to the pinion gear 88a into linear motion by the rack bar 88b. The tie rod 89 is connected to the rack bar 88b. That is, the steering device 80 is of rack and pinion type.

FIG. 2 is a perspective view of essential parts in the steering device 80 according to the embodiment. The pinion gear 88a is arranged within a pinion housing 88s. The rack bar 88b is arranged within a rack housing 88h integrally formed with the pinion housing 88s. A motor attachment portion 88m for attaching an electric motor 92 is formed in the pinion housing 88s, and the electric motor 92 is attached to the motor attachment portion 88m. The driving force generated by the electric motor 92 can be transmitted to the pinion gear 88a within the pinion housing 88s. The torque sensor 10 is attached to the pinion housing 88s, and is connected to a stub shaft 87 and a pinion gear 88a arranged inside the pinion housing 88s.

The torque sensor 10 detects the driver's steering force transmitted to the steering shaft 82 via the steering wheel 81 as steering torque. The vehicle speed sensor 91 detects the traveling speed (vehicle speed) of the vehicle in which the steering device 80 is mounted. Electric motor 92 , torque sensor 10 and vehicle speed sensor 91 are electrically connected to ECU 90 .

The ECU 90 controls operation of the electric motor 92 . The ECU 90 also acquires signals from the torque sensor 10 and the vehicle speed sensor 91 respectively. That is, the ECU 90 acquires the steering torque T from the torque sensor 10 and acquires the vehicle speed signal V from the vehicle speed sensor 91 . The ECU 90 is supplied with electric power from a power supply device (for example, an in-vehicle battery) 99 when an ignition switch 98 is on. The ECU 90 calculates an assist steering command value of the assist command based on the steering torque T and the vehicle speed signal V. FIG. Then, the ECU 90 adjusts the electric power value X to be supplied to the electric motor 92 based on the calculated assist steering command value. The ECU 90 acquires, as operation information Y, information about the induced voltage from the electric motor 92 or information output from a rotation detecting device such as a resolver provided in the electric motor 92 .

The operator's (driver's) steering force inputted to the steering wheel 81 is detected by the torque sensor 10 as the steering torque T. FIG. The ECU 90 acquires the steering torque T from the torque sensor 10 and the vehicle speed signal V from the vehicle speed sensor 91 . The ECU 90 then controls the operation of the electric motor 92 . The driving force generated by the electric motor 92 is transmitted to the pinion gear 88a as auxiliary steering torque. That is, to the pinion gear 88 a , the operator's steering force input to the steering wheel 81 is transmitted from the stub shaft 87 via the torsion bar, and the auxiliary steering torque is transmitted from the electric motor 92 . Since the auxiliary steering torque is transmitted from the electric motor 92 to the pinion gear 88a, the force required to operate the steering wheel 81 is reduced.

The steering force transmitted to the pinion gear 88a is transmitted to the tie rod 89 via the steering gear 88 to displace the wheels.

FIG. 3 is a perspective view of the torque sensor 10, the stub shaft 87 and the pinion gear 88a. The stub shaft 87 and the pinion gear 88a connected to the torque sensor 10 are connected to the torque sensor 10 from opposite sides of the torque sensor 10 . That is, the stub shaft 87 and the pinion gear 88a are arranged on opposite sides of the torque sensor 10 and extend in opposite directions.

Among them, the pinion gear 88a is formed with a gear portion 88ag that meshes with teeth (not shown) formed on the rack bar 88b. The pinion gear 88a has a worm wheel (not shown) that meshes with a worm gear (not shown) attached to the output shaft of the electric motor 92 at the end opposite to the end connected to the torque sensor 10. Attached splines 88as are formed. As a result, the pinion gear 88a receives the auxiliary steering torque from the electric motor 92 via the worm gear and the worm wheel.

FIG. 4 is a perspective view of essential parts of the constituent members of the torque sensor 10 shown in FIG. The torque sensor 10 has an input-side rotor 20 attached to the input shaft, which is one of the shaft members connected to the torque sensor 10, and an output-side rotor 70, which is attached to the output shaft which is the other shaft member. , and a printed circuit board 15 on which arithmetic elements 16 are arranged. In this embodiment, the input shaft is a stub shaft 87 and the input side rotor 20 is attached to the stub shaft 87 . The output shaft is a pinion gear 88a, and the output side rotor 70 is attached to the pinion gear 88a.

The input-side rotor 20 has a thin cylindrical sleeve 30 formed in a substantially cylindrical shape, and vane-like members 65 that are arranged around the thin cylindrical sleeve 30 and serve as detection members. The thin cylindrical sleeve 30 is made of a metal material and has an inner diameter approximately equal to the outer diameter of the stub shaft 87 at the position where the input side rotor 20 is attached. Therefore, the input side rotor 20 is attached to the stub shaft 87 by press-fitting the stub shaft 87 into the thin cylindrical sleeve 30 .

The blade member 65 is a thin plate member made of a metal material, and is arranged around the thin cylindrical sleeve 30 so that the thickness direction of the plate corresponds to the axial direction of the thin cylindrical sleeve 30 . The vane-like member 65 has a plurality of vane pieces separated from each other in the circumferential direction of the thin cylindrical sleeve 30 and is formed by arranging the plurality of vane pieces around the thin cylindrical sleeve 30 . The thin cylindrical sleeve 30 and the blade-shaped member 65 are integrally formed by the resin mold 60 made of resin material. That is, the vane-like member 65 is arranged around the thin cylindrical sleeve 30 by the resin mold 60 .

The blade-shaped member 65 of the input-side rotor 20 is arranged near one end of the input-side rotor 20 in the axial direction of the thin cylindrical sleeve 30 . The input-side rotor 20 is attached to the stub shaft 87 so that the side on which the blade-shaped member 65 is arranged is the side on which the output-side rotor 70 is arranged.

The output-side rotor 70 has a substantially cylindrical sleeve portion 71 and blade-shaped members 72 that are arranged around the sleeve portion 71 and serve as detection members. The sleeve portion 71 is made of a metal material, and has an inner diameter approximately equal to the outer diameter of the pinion gear 88a at a position where the output-side rotor 70 is attached. Therefore, the output side rotor 70 is attached to the pinion gear 88 a by press-fitting the pinion gear 88 a into the sleeve portion 71 .

The blade-like member 72 is a thin plate-like member made of a metal material, and is arranged around the sleeve portion 71 so that the thickness direction of the plate corresponds to the axial direction of the sleeve portion 71 . The blade-like member 72 has a plurality of blade pieces that are separated from each other in the circumferential direction of the sleeve portion 71 and is formed by arranging the plurality of blade pieces around the sleeve portion 71 .

In the blade-shaped member 72 of the output-side rotor 70 and the blade-shaped member 65 of the input-side rotor 20, the size of each blade in the circumferential direction and the interval between the blades in the circumferential direction are different. different. In this embodiment, the blade members 72 of the output-side rotor 70 are larger in size in the circumferential direction than the blade-shaped members 65 of the input-side rotor 20. The spacing in the circumferential direction is also large. In the output-side rotor 70, unlike the input-side rotor 20, the sleeve portion 71 and the blade-shaped member 72 are integrally formed as one member made of a metal material.

The blade-shaped member 72 of the output-side rotor 70 is arranged near one end of the output-side rotor 70 in the axial direction of the sleeve portion 71 . The output-side rotor 70 is attached to the pinion gear 88a in such a direction that the side on which the blade-shaped member 72 is arranged is the side on which the input-side rotor 20 is arranged.

The printed circuit board 15 is arranged between the input side rotor 20 and the output side rotor 70 . On the printed circuit board 15, movement of the blade member 65 of the input side rotor 20 in the circumferential direction around the stub shaft 87 and movement of the blade member 65 of the output side rotor 70 in the circumferential direction around the pinion gear 88a are recorded. A detection coil (not shown) for detecting movement of the member 72 is mounted. The detection coils are arranged at positions facing the vane-shaped member 65 of the input side rotor 20 and the vane-shaped member 72 of the output side rotor 70 .

The detection coil is configured such that the inductance changes when the relative position in the circumferential direction between the vane-shaped member 65 of the input side rotor 20 and the vane-shaped member 72 of the output side rotor 70 changes. there is The arithmetic element 16 arranged on the printed circuit board 15 detects the relative relationship between the vane-shaped member 65 of the input side rotor 20 and the vane-shaped member 72 of the output side rotor 70 in the circumferential direction based on the change in the inductance around the detection coil. It is an IC for calculation that calculates displacement. Between the stub shaft 87 to which the input side rotor 20 is attached and the pinion gear 88a to which the output side rotor 70 is attached, rotational torque is transmitted via the torsion bar. The slight twist slightly changes the relative angle between the stub shaft 87 and the pinion gear 88a in the circumferential direction. The inductance around the detection coil mounted on the printed circuit board 15 changes when the relative angle between the stub shaft 87 and the pinion gear 88a changes. A relative angle with the pinion gear 88a is detected to detect the rotational torque. Thereby, the torque sensor 10 can detect the rotational torque transmitted between the stub shaft 87 and the pinion gear 88a.

FIG. 5 is an explanatory diagram showing a state where the input side rotor 20 is attached to the stub shaft 87. As shown in FIG. 5, the blade-shaped member 65 of the input-side rotor 20 is omitted. Further, in the following description, regarding the thin cylindrical sleeve 30 or the input side rotor 20, the axial direction is the axial direction of the cylinder that is the shape of the thin cylindrical sleeve 30, and the circumferential direction is: It is in the circumferential direction of the cylinder which is the shape of the thin cylindrical sleeve 30 . The resin mold 60 of the input-side rotor 20 has a sleeve support portion 60 a that supports the thin cylindrical sleeve 30 and a blade-like member support portion 60 b that supports the blade-like member 65 . The sleeve support portion 60 a is arranged radially outward of the thin cylindrical sleeve 30 and has a support member extending along the outer peripheral surface 32 of the thin cylindrical sleeve 30 in the axial direction of the thin cylindrical sleeve 30 . The sleeve support portion 60a has a plurality of support members, and the plurality of support members are arranged side by side in the circumferential direction.

The blade-shaped member supporting portion 60b is formed in the shape of a flange in the resin mold 60, and is formed over one circumference in the circumferential direction such that the thickness direction of the flange corresponds to the axial direction of the thin cylindrical sleeve 30. . The vane-shaped member 65 is attached to the vane-shaped member support portion 60b formed in this manner and is supported by the vane-shaped member support portion 60b.

In the input side rotor 20, the resin mold 60 is attached to the thin cylindrical sleeve 30 in such a positional relationship that the blade-shaped member supporting portion 60b is located near one end in the axial direction of the thin cylindrical sleeve 30. and the thin cylindrical sleeve 30 are integrally formed.

FIG. 6 is a perspective view of the thin cylindrical sleeve 30 included in the input rotor 20 shown in FIG. The thin cylindrical sleeve 30 is a metal member formed in a substantially cylindrical shape. The thin cylindrical sleeve 30 has a tapered portion 34 formed on the inner peripheral surface 33 at a position near one end 31 in the axial direction of the thin cylindrical sleeve 30 . A tapered portion 34 formed on an inner peripheral surface 33 of the thin cylindrical sleeve 30 is formed so as to taper in a direction in which the plate thickness becomes thinner toward the end portion 31 in the axial direction of the thin cylindrical sleeve 30 . Specifically, the input side rotor 20 is attached to the stub shaft 87 by press-fitting the stub shaft 87 into the thin cylindrical sleeve 30 . It is formed on the inner peripheral surface 33 of the thin cylindrical sleeve 30 on the side where the end portion 31 on the side to be press-fitted is located.

FIG. 7 is a plan view of a thin plate 38 used to manufacture the thin cylindrical sleeve 30 shown in FIG. The thin cylindrical sleeve 30 is formed by bending a thin plate 38 into a cylindrical shape. The thin plate 38 is formed in a belt-like shape, and the thin cylindrical sleeve 30 is formed by bending the thin plate 38 so that the longitudinal direction of the thin plate 38 becomes the circumferential direction of the cylinder. That is, the axial direction of the thin cylindrical sleeve 30 corresponds to the width direction of the thin plate 38 before being bent into a cylindrical shape, and the circumferential direction of the thin cylindrical sleeve 30 corresponds to the direction of the thin plate 38 before being bent into a cylindrical shape. A thin cylindrical sleeve 30 is formed corresponding to the lengthwise direction of the thin plate 38 .

The thin cylindrical sleeves 30 are joined together by circumferentially abutting the thin plates 38 on opposite ends in the longitudinal direction as joining sides 40 and welding the joining sides 40 to each other at a plurality of welding portions 50 . For this reason, in the thin cylindrical sleeve 30 formed in a substantially cylindrical shape, the joint sides 40 of the thin plates 38 that are abutted and joined to each other in the circumferential direction of the cylinder are formed extending in the axial direction of the cylinder. The welded portion 50 that welds the joint side 40 is a welded portion 50 by laser welding in this embodiment, and the joint side 40 is welded by a plurality of welded portions 50 .

The joint sides 40 located on both sides in the length direction of the thin plate 38 are each formed of a straight portion 41 extending in the axial direction of the cylinder, which is in the shape of the thin cylindrical sleeve 30, and curved in the circumferential direction of the cylinder with respect to the axial direction. It is formed by being combined with the curved portion 42 . The joint sides 40 each having a straight portion 41 and a curved portion 42 and joined to each other are composed of a convex side joint side 40a and a concave side joint side 40b. is joined. That is, of the joint sides 40 positioned on both sides in the length direction of the thin plate 38 before being bent into a cylindrical shape, the joint side 40 positioned on the one end side is the convex side joint side 40a, and the joint side 40 on the other end side. The connecting side 40 is a concave side connecting side 40b.

Of the convex-side joint side 40a and the concave-side joint side 40b, the convex-side joint side 40a protrudes in a direction approaching the concave-side joint side 40b in a state where the convex-side joint side 40a is joined to the concave-side joint side 40b. have. That is, the convex portion 43 is curved from the straight portion 41 extending in the axial direction at the joint side 40a on the joint side 40a to the joint side 40b on the side of the concave portion by bending at the curved portion 42 in a direction approaching the joint side 40b on the side of the concave portion. It is formed to be convex in the approaching direction. In other words, when the thin plate 38 is unfolded without being bent into a cylindrical shape, the convex portion 43 of the joint side 40 a is bent at the curved portion 42 of the joint side 40 , thereby bending the thin plate 38 . It is formed so as to protrude toward the side opposite to the side where the recess side joint side 40b is located in the length direction.

The convex portion 43 of the joint side 40a on the convex portion side is formed to be convex in the length direction of the thin plate 38, and the width in the axial direction at the position of the root 43a of the convex portion 43 is greater than the width in the axial direction. It is formed to have a portion where the width at the More specifically, the convex portion 43 has a curved portion 42 that is convex and curved in the axial direction in the direction in which the width of the convex portion 43 increases, between the base 43a of the convex portion 43 and the tip portion 43b of the convex portion 43. have. As a result, the protrusion 43 is wider than the width in the axial direction at the position of the root 43a of the protrusion 43, and the axial center at a predetermined position between the tip 43b of the protrusion 43 and the root 43a of the protrusion 43 is wider than the width at the position of the root 43a of the protrusion 43. It is formed so that the width in the direction is larger.

In this case, the width in the axial direction at the position of the root 43a will be explained. The width at the position 43 a is the distance between the curved portions 42 arranged on both sides in the axial direction at the base 43 a of the projection 43 .

On the other hand, the recess-side joining edge 40b has a recess 44 that is recessed in a direction away from the protrusion-side joining edge 40a when joined to the protrusion-side joining edge 40a. That is, the concave portion 44 is curved from the straight portion 41 extending in the axial direction at the joint side 40b on the joint side 40b at the curved portion 42 in a direction away from the joint side 40a on the convex side. It is recessed and formed in the direction to separate. In other words, when the thin plate 38 is unfolded without being bent into a cylindrical shape, the concave portion 44 of the joint side 40b is bent at the curved portion 42 of the joint side 40 so that the length of the thin plate 38 is increased. In the direction, it is recessed toward the side where the convex side joint side 40a is located.

The recess 44 of the recess-side joint side 40b is recessed in the longitudinal direction of the thin plate 38 and has a width in the axial direction larger than that at the position of the opening 44a of the recess 44 in the axial direction. It is formed with a Specifically, the recessed portion 44 is a curved portion that is recessed and curved in the axial direction in the direction in which the width of the recessed portion 44 increases between the opening portion 44a of the recessed portion 44 and the bottom portion 44b that is the most recessed portion of the recessed portion 44. 42. As a result, the width of the recess 44 in the axial direction at a predetermined position between the opening 44 a of the recess 44 and the bottom 44 b of the recess 44 is greater than the width in the axial direction at the position of the opening 44 a of the recess 44 . is formed to be larger.

Regarding the width in the axial direction at the position of the opening 44a in this case, since the concave portion 44 is connected to the linear portion 41 extending in the axial direction by the curved portion 42, the opening of the concave portion 44 The width at the position 44 a is the distance between the curved portions 42 arranged on both sides in the axial direction at the position of the opening 44 a of the recess 44 .

The convex portion 43 of the joint side 40a on the convex side and the concave portion 44 of the joint side 40b on the concave side formed in this way are formed in substantially the same shape. The convex portion 43 of the joint side 40a on the convex side and the concave portion 44 of the joint side 40b on the concave side are positioned at the same position in the width direction of the thin plate 38, that is, in the axial direction of the cylinder that is the shape of the thin cylindrical sleeve 30. formed by As a result, when forming the thin plate 38 into a cylindrical shape by abutting joint sides 40 located on both sides in the length direction of the thin plate 38, the convex portion 43 formed on the joint side 40a on the convex portion side becomes a concave portion. The joint sides 40 are joined to each other by entering the concave portion 44 formed in the side joint sides 40b.

At that time, the convex portion 43 has a portion that protrudes in a direction in which the width in the axial direction becomes larger than the root 43 a of the convex portion 43 , and the concave portion 44 is axially wider than the opening portion 44 a of the concave portion 44 . It has a portion that is recessed in the direction in which the width in the center direction increases. That is, the portion of the projection 43 that is wider in the axial direction than the root 43 a is wider in the axial direction than the opening 44 a of the recess 44 . Therefore, when the convex portion 43 of the joint side 40a on the convex side enters the concave portion 44 of the joint side 40b on the concave side, the convex portion 43 cannot be removed from the concave portion 44 in the circumferential direction of the thin cylindrical sleeve 30. As a result, the convex portion 43 and the concave portion 44 are combined.

In this embodiment, two sets of the convex portion 43 and the concave portion 44 formed on the joint side 40 are formed. That is, two protrusions 43 are formed on the joint side 40a on the convex side, and the joint side 40b on the joint side 40b has the same position in the axial direction as the two convex parts 43 of the joint side 40a on the convex side. Two recesses 44 are formed at the position. When the joint sides 40 are joined together, the two protrusions 43 of the joint side 40a on the convex side enter and join the two recesses 44 formed on the joint side 40b on the concave side.

Joint sides 40 positioned at both ends in the length direction of the thin plate 38 each have a folded portion 45 . The folded portion 45 is a portion in which the joining side 40 is folded back in the axial direction of the cylinder that is the shape of the thin cylindrical sleeve 30 , so that the direction of the joining side 40 in the axial direction is the opposite direction. The folded portion 45 may be formed by the straight portion 41 , the curved portion 42 , or a combination of the straight portion 41 and the curved portion 42 . The folded portion 45 is formed as a convex-side folded portion 45a on the convex portion 43 on the convex-side joint side 40a, and is formed as a concave-side folded portion 45b on the concave portion 44 on the concave-side joint side 40b.

Specifically, the joint side 40a on the convex portion side is formed to have a larger width than the width in the axial direction at the base 43a of the convex portion 43 and at the position of the base 43a of the convex portion 43. A convex portion side folded portion 45a is formed between the portion where the convex portion is bent. That is, the convex portion 43 has a portion between the tip portion 43b of the convex portion 43 and the root 43a, which is formed so that the width in the axial direction is larger than the width of the portion of the root 43a. The extending direction of the joint side 40a is folded back at a position from the base 43a of the projection 43 toward the tip 43b, or at a position from the tip 43b to the base 43a. At the joint side 40a on the projecting portion side, the projecting portion side folded portion 45a is formed between the root 43a and the tip portion 43b of the projecting portion 43 in this manner.

In addition, in the recessed portion side joint side 40b, a recessed portion side folded portion 45b is formed between the opening portion 44a in the recessed portion 44 and a portion formed with a width larger than the width in the axial direction at the position of the opening portion 44a. is formed. That is, the recessed portion 44 has a portion formed with a width in the axial direction larger than the width of the opening portion 44a between the bottom portion 44b of the recessed portion 44 and the opening portion 44a. The extending direction is folded back at a position from the opening 44a of the recess 44 toward the bottom 44b or from the bottom 44b toward the opening 44a. In this manner, the concave portion side folded portion 45b is formed between the opening portion 44a and the bottom portion 44b of the concave portion 44 at the concave portion side joining edge 40b.

FIG. 8 is a detailed view of part C in FIG. FIG. 9 is a detailed view of part D in FIG. The thin cylindrical sleeve 30, which is formed by bending the thin plate 38 into a cylindrical shape, has the shape of the fitting boundary appearing on the joint sides 40 on both sides of the thin plate 38 in the shape of the thin cylindrical sleeve 30 in the axial direction of the cylinder. By folding back at , each joint side 40 has a folded portion 45 , which is a portion in which the directions of the boundaries in the axial direction are opposite to each other. The joint sides 40 on which the folded portion 45 is formed are positioned in the circumferential direction from the folded portion 45 of one joint side 40 when the joint sides 40 are joined together, and are part of the one joint side 40 . , and the folded portion of one joint side 40, the folded portion 45 of the other joint side 40 is positioned and joined. That is, the joint sides 40 on which the folded portions 45 are respectively formed are engaged with each other in the circumferential direction and joined. In this case, the portion of the joint side 40 that is positioned in the circumferential direction from the folded portion 45 of the joint side 40 is a portion of the joint side 40 that is at the same position in the axial direction as the folded portion 45 . .

More specifically, when joining the convex joint side 40a and the concave joint side 40b, the convex part 43 of the convex joint side 40a is inserted into the recess 44 of the concave joint side 40b. Since the convex portion 43 of the joint side 40a on the convex side and the concave portion 44 of the joint side 40b on the concave side are formed in substantially the same shape, when the convex portion 43 is inserted into the concave portion 44, The convex-side folded portion 45a formed in the convex portion 43 and the concave-side folded portion 45b formed in the concave portion 44 are adjacent to each other.

A portion of the convex-side joining edge 40 a located in the circumferential direction from the convex-side folded portion 45 a (see part E in FIG. 9 ) is a curved portion 42 positioned at the root 43 a of the convex portion 43 . . That is, a part of the joint side 40a on the convex side, which is located at the same position in the axial direction as the folded part 45a on the convex side (see part E in FIG. 9), is the curved part 42 located at the root 43a of the convex part 43 It has become. For this reason, the concave-side folded portion 45b of the concave-side joint side 40b is a curved portion 42 of the root 43a of the convex portion 43, which is a part located in the circumferential direction from the convex-side folded portion 45a of the convex-side joint side 40a. and the projection-side folded portion 45a of the projection-side joint side 40a.

In addition, a portion of the recess-side joint side 40b located in the circumferential direction from the recess-side folded portion 45b (see FIG. 9, part F) is the curved portion 42 located between the opening 44a and the bottom 44b of the recess 44. It has become. That is, a part of the recessed joint side 40b whose position in the axial direction is the same as that of the recessed folded part 45b (see part F in FIG. 9) is located between the opening 44a and the bottom 44b of the recessed part 44. A curved portion 42 is formed. For this reason, the convex-side folded portion 45a of the convex-side joint side 40a is formed by the opening 44a and the bottom portion 44b of the concave portion 44, which are part of the circumferential direction from the concave-side folded portion 45b of the concave-side joint side 40b. It is positioned between the curved portion 42 between and the recess side folded portion 45b of the recess side joint side 40b.

As described above, the joint sides 40 are located between a portion of the convex-side joint side 40a located in the circumferential direction from the convex-side folded part 45a and the concave-side joint side 40b of the concave-side joint side 40b. The folded portion 45b is located, and the convex portion side folded portion 45a of the convex portion side joint side 40a is located between a portion of the concave portion side joint side 40b in the circumferential direction from the concave portion side folded portion 45b and the concave portion side folded portion 45b. are spliced together.

The folded portion 45 of the joint side 40 has a portion where the inclination angle θ in the circumferential direction with respect to the axial direction of the thin cylindrical sleeve 30 is 45° or less. That is, both the convex-side folded portion 45a of the convex-side joint side 40a and the concave-side folded portion 45b of the concave-side joint side 40b have an inclination angle in the circumferential direction with respect to the axial direction of the thin cylindrical sleeve 30. It is formed to have a portion where θ is 45° or less.

For example, when the folded portion 45 is formed by the straight portion 41, the inclination angle θ of the straight portion 41 forming the folded portion 45 in the circumferential direction with respect to the axial direction of the thin cylindrical sleeve 30 is 45° or less. ing. Further, when the folded portion 45 is formed by the curved portion 42, the inclination angle θ of the tangential line of the curved portion 42 forming the folded portion 45 to the axial direction of the thin cylindrical sleeve 30 in the circumferential direction is 45° or less. It has a part that becomes That is, in the folded portion 45, the inclination angle θ of the tangent line of the straight portion 41 forming the folded portion 45 or the curved portion 42 forming the folded portion 45 in the circumferential direction with respect to the axial direction of the thin cylindrical sleeve 30 is 45°. ° or less.

A plurality of welded portions 50 for welding the joint sides 40 are applied at the positions of the folded portions 45 in the state where the joint sides 40 having the folded portions 45 are joined to each other. That is, the convex-side joint side 40a and the concave-side joint side 40b correspond to the convex-side folded part 45a and the concave part in a state where the convex part 43 of the convex-side joint side 40a enters the concave part 44 of the concave-side joint side 40b. The welded portion 50 is positioned and joined to the portion adjacent to the side folded portion 45b. As described above, the plurality of welded portions 50 applied to the joint sides 40 are positioned at the positions of the folded portions 45 in a state in which the joint sides 40 are joined together, and the adjacent folded portions 45 are welded to each other, whereby the joining is performed. The sides 40 are joined so as not to be separated from each other.

Next, a procedure for assembling the stub shaft 87 to the thin cylindrical sleeve 30 of the input side rotor 20 in the torque sensor 10 will be described. The procedure shown below is an example of the manufacturing process, and the order of the manufacturing process can be arbitrarily changed. The thin cylindrical sleeve 30 has a belt-like thin plate 38 with joint sides 40 formed on both ends in the length direction, and a convex portion 43 formed on one joint side 40 by a linear portion 41 and a curved portion 42 , and a joint portion 43 on the other joint side 40 . A recess 44 is formed in the side 40 . Thereby, a folded portion 45 is formed on each of the joint sides 40 . A tapered portion 34 is formed at one end 31 of the thin plate 38 in the width direction.

After the convex portion 43 and the concave portion 44 are formed, and the tapered portion 34 is also formed, the thin plate 38 is mounted so that the length direction of the thin plate 38 becomes the circumferential direction, and the surface on which the tapered portion 34 is formed becomes the inner peripheral surface 33 . are bent into a cylindrical shape, and the convex portion 43 of the joint side 40a on the convex side is inserted into the concave portion 44 of the joint side 40b on the concave side, and the joint sides 40 are brought into contact with each other. By inserting the convex portion 43 of the joint side 40a on the convex side into the recessed portion 44 of the joint side 40b on the concave side, the thin plate 38 does not come off from the concave portion 44 in the circumferential direction. , the relative movement in the direction in which the joint sides 40 are separated from each other in the circumferential direction is regulated.

The convex portion 43 of the joint side 40a on the convex side is inserted into the concave portion 44 of the joint side 40b on the concave side, and the joint sides 40 are joined together in a state in which the folded portions 45 of the joint side 40a on the convex side and the joint side 40b on the concave side are adjacent to each other. After the butting, the joint sides 40 are welded together by a plurality of welding portions 50 . When a force acts on the thin cylindrical sleeve 30 in a direction in which the joint sides 40 are separated from each other in the circumferential direction, the welded portion 50 allows relative movement in the direction in which the joint sides 40 are separated from each other in the circumferential direction. By regulating with , it is applied to a position where a force in the compression direction is generated between the convex portion 43 and the concave portion 44 . That is, the convex portion 43 and the concave portion 44 have a portion where a compressive stress is generated when a force is applied in a direction in which the joint sides 40 are separated from each other while the convex portion 43 is in the concave portion 44. 50 is applied to positions where compressive stress is generated in the convex portion 43 and the concave portion 44 . Specifically, the plurality of welded portions 50 for welding the joint sides 40 are applied to portions where the folded portions 45 are adjacent to each other. In this manner, the thin plate 38 is bent into a cylindrical shape, the joint sides 40 are butted against each other, and the folded portions 45 are welded by a plurality of welding portions 50 to form the substantially cylindrical thin-walled cylindrical sleeve 30 .

FIG. 10 is a cross-sectional view showing a state where the input side rotor 20 is attached to the stub shaft 87. As shown in FIG. After the thin cylindrical sleeve 30 is formed, the thin cylindrical sleeve 30 and the blade-like member 65 manufactured in a separate process are integrally formed by the resin mold 60 . That is, injection molding of the resin mold 60 is performed in a state in which the thin cylindrical sleeve 30 and the blade-shaped member 65 are aligned. Thereby, the input side rotor 20 is manufactured. At this time, the blade-like member 65 integrally formed with the thin cylindrical sleeve 30 by the resin mold 60 is positioned at the end of the thin cylindrical sleeve 30 on the side where the tapered portion 34 is formed on the inner peripheral surface 33 in the axial direction of the thin cylindrical sleeve 30 . It is arranged near the end 31 on the opposite side of 31 . The input-side rotor 20 is attached to the stub shaft 87 by press-fitting the stub shaft 87 into the thin-walled cylindrical sleeve 30 of the input-side rotor 20 manufactured in this way.

The stub shaft 87 is press-fitted into the thin cylindrical sleeve 30 from the end portion 31 side of the thin cylindrical sleeve 30 where the tapered portion 34 is formed on the inner peripheral surface 33 . The stub shaft 87 is formed with a press-fitting portion 87 a having an outer diameter approximately equal to the inner diameter of the thin cylindrical sleeve 30 and being press-fitted into the thin cylindrical sleeve 30 . The press-fitting of the stub shaft 87 into the thin cylindrical sleeve 30 is performed by inserting the press-fitting portion 87a of the stub shaft 87 from the end portion 31 side of the thin cylindrical sleeve 30 where the tapered portion 34 is formed. The stub shaft 87 can be easily inserted into the inner peripheral surface 33 of the thin cylindrical sleeve 30 by inserting it from the end portion 31 side where the tapered portion 34 is formed. Therefore, the stub shaft 87 can be easily press-fitted into the thin cylindrical sleeve 30 .

A plurality of contact portions 31a (see FIG. 6) protruding in the axial direction are formed at intervals in the circumferential direction at the end portion 31 of the thin cylindrical sleeve 30 on the side where the tapered portion 34 is formed. The stub shaft 87 has a stepped portion adjacent to the press-fitting portion 87a at a predetermined position in the axial direction and formed by increasing the diameter of the press-fitting portion 87a. 87b are formed. The stub shaft 87 press-fitted into the thin cylindrical sleeve 30 is inserted into the thin cylindrical sleeve 30 until the stepped portion 87b contacts the contact portion 31a of the thin cylindrical sleeve 30 . As a result, the input side rotor 20 having the thin cylindrical sleeve 30 and the stub shaft 87 are axially positioned and fixed to each other when the stub shaft 87 is press-fitted into the thin cylindrical sleeve 30 .

When press-fitting the thin cylindrical sleeve 30 onto the stub shaft 87, the stub shaft 87 may be inserted into the fixed thin cylindrical sleeve 30, or the thin cylindrical sleeve 30 may be inserted into the fixed stub shaft 87. You can fit them together.

Here, when the stub shaft 87 is press-fitted into the thin cylindrical sleeve 30 , a force acts on the thin cylindrical sleeve 30 to spread in the circumferential direction. When the stub shaft 87 is press-fitted into the thin cylindrical sleeve 30 , the force acting on the thin cylindrical sleeve 30 and spreading in the circumferential direction also acts on the joint side 40 . Since the joint sides 40 located on both sides in the length direction of the thin plate 38 are welded together by a plurality of welding portions 50, the force acting on the thin cylindrical sleeve 30 in the circumferential direction is It also acts on the welds 50 that weld them together.

When a force in the circumferential direction acts on the welded portion 50, the welded portion 50 may easily break depending on how the force acts on the welded portion 50. However, in the present embodiment, the welded portion 50 is thin. The stub shaft 87 is located at a position where compressive stress is generated at the joint side 40 when the stub shaft 87 is press-fitted into the cylindrical sleeve 30 . As a result, even if the stub shaft 87 is press-fitted into the thin cylindrical sleeve 30 , even if a circumferential force acts on the thin cylindrical sleeve 30 , breakage of the welded portion 50 can be suppressed.

FIG. 11 is an explanatory diagram showing a case where the welded portion 50 is located at a position where tensile stress is generated. That is, the thin cylindrical sleeve 30 is formed into a substantially cylindrical shape by bending the thin plate 38 into a cylindrical shape and abutting the joint sides 40 located on both sides in the length direction of the thin plate 38 . When a force that spreads in the circumferential direction acts on the joint sides 40 , tensile stress in the direction in which the joint sides 40 separate from each other is generated at many positions.

For example, at the position of the linear portion 41 extending from the end portion 31 in the axial direction of the thin cylindrical sleeve 30 on the joint side 40, when a force is generated in the thin cylindrical sleeve 30 to spread in the circumferential direction, the opposing linear portion A force acts in the direction that 41 are separated from each other. Therefore, when the welded portion 50 is formed at the position of the straight portion 41 on the joint side 40 as shown in FIG. Tensile stress is generated when a force is generated.

Therefore, for example, when the force in the circumferential direction acting on the joint edge 40 partially increases and the tensile stress generated at the welded portion 50 increases and exceeds the allowable stress of the welded portion 50, the welded portion 50 breaks. There is a possibility of doing so. If the welded portion 50 breaks, the joint side 40 cannot be properly joined by the welded portion 50 .

On the other hand, in the present embodiment, when the stub shaft 87 is press-fitted into the thin cylindrical sleeve 30 that welds the joint sides 40 of the thin cylindrical sleeve 30 to each other, a compressive stress is generated at the joint sides 40 of the welded portion 50 . located in position. As a result, even when the stub shaft 87 is press-fitted into the thin cylindrical sleeve 30 and a force acts on the thin cylindrical sleeve 30 in the circumferential direction, it is possible to suppress the tensile stress from being generated in the welded portion 50 , and the tensile stress causes welding. Breakage of the portion 50 can be suppressed. As a result, it is possible to maintain the joint at the joint side 40 when tension is applied in the circumferential direction.

In addition, the joint sides 40 of the thin cylindrical sleeve 30 are folded back of the other joint side 40 between the folded portion 45 and a part located in the circumferential direction from the folded portion 45 in the circumferential direction of each joint side 40 . A portion 45 is positioned and joined, and the welded portion 50 is positioned at the folded portion 45 . Since the folded portion 45 of the other joint side 40 is positioned between the folded portion 45 and a part of the joint side 40 located in the circumferential direction from the folded portion 45 , the joint sides 40 When a force acts on the thin-walled cylindrical sleeve 30 in a direction away from them, a force acts in the compression direction between the facing folded portions 45 .

Therefore, when the welded portion 50 is positioned at the folded portion 45 and a force acts on the thin cylindrical sleeve 30 in a direction in which the joint sides 40 are separated from each other in the circumferential direction, the welded portion 50 is subjected to compressive stress. occurs. Therefore, even when the stub shaft 87 is press-fitted into the thin cylindrical sleeve 30 and a force acts on the thin cylindrical sleeve 30 in the circumferential direction, it is possible to prevent the welded portion 50 from breaking due to tensile stress. As a result, it is possible to maintain the joint at the joint side 40 when tension is applied in the circumferential direction.

In addition, since the folded portion 45 has a portion where the inclination angle θ in the circumferential direction with respect to the axial direction of the thin cylindrical sleeve 30 is 45° or less, a force is applied in the direction in which the joint sides 40 are separated from each other in the circumferential direction. Even when the force acts on the thin cylindrical sleeve 30, breakage of the welded portion 50 can be suppressed. That is, when the inclination angle θ of the folded portion 45 in the circumferential direction with respect to the axial direction of the thin cylindrical sleeve 30 is greater than 45°, the folded portion 45 receives a force in the direction in which the joint sides 40 are separated from each other in the circumferential direction. When acting on the thin-walled cylindrical sleeve 30 , a shearing force in the extending direction of the folded portions 45 is likely to occur between the opposing folded portions 45 . Therefore, when the inclination angle θ of the folded portion 45 with respect to the axial direction of the thin cylindrical sleeve 30 is larger than 45°, when a force acts on the thin cylindrical sleeve 30 in a direction in which the joint sides 40 are separated from each other in the circumferential direction, , shear stress is likely to be generated also in the welded portion 50 located at the folded portion 45, and it becomes difficult to suppress breakage of the welded portion 50. - 特許庁

On the other hand, when the inclination angle θ of the folded portions 45 in the circumferential direction with respect to the axial direction of the thin cylindrical sleeve 30 is 45° or less, it is possible to suppress the tendency of shear force to be generated between the opposing folded portions 45 . , it is possible to prevent shear stress and tensile stress from easily occurring in the welded portion 50 positioned at the folded portion 45 . Therefore, even when the stub shaft 87 is press-fitted into the thin cylindrical sleeve 30 and a force acts on the thin cylindrical sleeve 30 in the circumferential direction, it is possible to prevent the welded portion 50 from breaking due to shear stress or tensile stress. . As a result, it is possible to maintain the joint at the joint side 40 when tension is applied in the circumferential direction.

The joint sides 40 that are joined together include a convex side joint side 40a having a convex portion 43 and a concave side joint side 40b having a concave portion 44. The convex side joint side 40a and the concave side joint side 40b are formed. are joined with the protrusion 43 entering the recess 44 . The force acting on the thin-walled cylindrical sleeve 30 in the circumferentially expanding direction with respect to the joining edge 40 where the convex portion 43 is inserted into the concave portion 44 to be joined is a force in the direction in which the convex portion 43 is pulled out from the concave portion 44 in the circumferential direction. act as a force.

On the other hand, the protrusion 43 of the joint side 40a on the convex side and the recess 44 of the joint side 40b on the side of the recess are in a direction in which the joint sides 40 are separated from each other in the circumferential direction when the protrusion 43 enters the recess 44. Regulates relative movement to That is, when a force is applied to the thin cylindrical sleeve 30 in a direction in which the joint sides 40 are separated from each other in the circumferential direction, the protrusions 43 and the recesses 44 formed on the joint sides 40 are prevented from moving in the circumferential direction. By restricting, relative movement in the direction in which the joint sides 40 are separated from each other in the circumferential direction is restricted. Therefore, when a force acts on the thin cylindrical sleeve 30 in a direction in which the joint sides 40 are separated from each other in the circumferential direction, the protrusion 43 and the recess 44 are affected by the circumferential force acting on the joint sides 40 . A portion where compressive stress is generated is generated.

At the welded portion 50 that joins the joint sides 40 together, when a force acts on the thin-walled cylindrical sleeve 30 in the direction in which the joint sides 40 are separated from each other in the circumferential direction, a force in the compression direction is applied between the convex portion 43 and the concave portion 44 . It is applied to the position where it occurs. As a result, even when the stub shaft 87 is press-fitted into the thin cylindrical sleeve 30 and a force acts on the thin cylindrical sleeve 30 in the circumferential direction, it is possible to suppress the tensile stress from being generated in the welded portion 50 , and the tensile stress causes welding. Breakage of the portion 50 can be suppressed. As a result, it is possible to maintain the joint at the joint side 40 when tension is applied in the circumferential direction.

Further, the convex portion 43 is formed to have a portion whose width is larger than the width at the position of the base 43 a of the convex portion 43 , and the convex portion-side joint side 40 a is formed at the base of the convex portion 43 in the convex portion 43 . A protrusion-side folded portion 45a is formed between the portion 43a and a portion formed with a width larger than the width at the base 43a of the protrusion 43. As shown in FIG. Further, the recess 44 is formed to have a portion whose width is larger than the width at the position of the opening 44a of the recess 44, and the recess-side joint side 40b is formed between the opening 44a of the recess 44 and the opening 44a. A concave portion side folded portion 45b is formed between the portion formed with a width larger than the width at the position.

As a result, when the convex portion 43 enters the concave portion 44 and the convex-side joint side 40a and the concave-side joint side 40b are joined, the convex-side folded portion 45a and the concave-side folded portion 45b face each other. Therefore, when a force acts on the thin cylindrical sleeve 30 in a direction in which the joint sides 40 are separated from each other in the circumferential direction, the convex-side folded portion 45a and the concave-side folded portion 45b prevent the other from moving in the circumferential direction. Since it is regulated, it is possible to prevent the protrusion 43 from coming off the recess 44 and prevent the joining sides 40 from being separated from each other in the circumferential direction. As a result, it is possible to maintain the joint at the joint side 40 when tension is applied in the circumferential direction.

In addition, since the convex-side folded-back portion 45a and the concave-side folded-back portion 45b are joined to face the convex-side joint side 40a and the concave-side joint side 40b, the joint sides 40 are separated from each other in the circumferential direction. When a force acts, a compressive stress is generated between the convex-side folded portion 45a and the concave-side folded portion 45b. Since the welded portion 50 is formed at the position of the folded portion 45, even if a force acts on the thin cylindrical sleeve 30 in a direction in which the joint sides 40 are separated from each other in the circumferential direction, tensile stress is generated in the welded portion 50. It is possible to suppress breakage of the welded portion 50 due to tensile stress. As a result, it is possible to maintain the joint at the joint side 40 when tension is applied in the circumferential direction.

[Modification]
In the thin cylindrical sleeve 30 according to the above-described embodiment, two sets of the protrusions 43 and the recesses 44 are provided on the joint side 40, but the number of the protrusions 43 and the recesses 44 may be different. may be FIG. 12 is a modification of the thin cylindrical sleeve 30 according to the embodiment, and is an explanatory view showing a configuration in which a pair of projections 43 and recesses 44 are formed on the joint side 40. As shown in FIG. For example, as shown in FIG. 12, one set of the convex portion 43 and the concave portion 44 provided on the joint side 40 may be used. That is, one convex portion 43 having a convex-side folded portion 45a is formed on the convex-side joint side 40a, and one concave portion 44 having a concave-side folded portion 45b is formed on the concave-side joint side 40b. Alternatively, the joining sides 40 may be joined by inserting one protrusion 43 into one recess 44 .

Even if the convex portion 43 and the concave portion 44 provided on the joint side 40 are one set, the convex portion 43 and the concave portion 44 are formed with the folded portion 45 and the welded portion 50 is positioned at the folded portion 45 so that the joining can be performed. Even when a force acts in a direction in which the sides 40 are separated from each other in the circumferential direction, it is possible to suppress the occurrence of tensile stress in the welded portion 50 . Thereby, it is possible to suppress breakage of the welded portion 50 and maintain the joint at the joint side 40 .

In addition, in the thin cylindrical sleeve 30 according to the embodiment described above, the joint side 40 is formed by combining the straight portion 41 and the curved portion 42, but the joint side 40 may be formed in a form other than this. may be FIG. 13 is a modified example of the thin cylindrical sleeve 30 according to the embodiment, and is an explanatory view showing a form in which the convex portion 43 and the concave portion 44 are respectively formed in a trapezoidal shape. FIG. 14 is a modification of the thin cylindrical sleeve 30 according to the embodiment, and is an explanatory diagram showing a form in which the convex portion 43 and the concave portion 44 are formed in a T shape. For example, as shown in FIGS. 13 and 14 , the joint side 40 may be formed by combining straight portions 41 without having curved portions 42 .

When the joint side 40 is formed by combining the linear portions 41, the convex portion 43 and the concave portion 44 are formed in a trapezoidal shape as shown in FIG. , may be formed so as to face the base 43a of the convex portion 43 or the opening portion 44a of the concave portion 44. As shown in FIG. By forming the convex portion 43 and the concave portion 44 in a trapezoidal shape, the oblique side of the trapezoid can be turned into the folded portion 45 . Thus, by positioning the welded portion 50 at the position of the oblique side of the trapezoid between the convex portion 43 and the concave portion 44 formed in a trapezoidal shape, even if a force is applied in a direction separating the joint sides 40 in the circumferential direction. , the occurrence of tensile stress in the welded portion 50 can be suppressed, and breakage of the welded portion 50 can be suppressed.

Alternatively, the projection 43 and the recess 44 are formed in a T-shaped contour shape as shown in FIG. 44a may be formed. By forming the convex portion 43 and the concave portion 44 in a T-shaped contour shape, the contour of the T-shaped portion extending in the horizontal direction is positioned on the side of the base 43a of the convex portion 43 and the opening portion 44a of the concave portion 44. The portion can be a folded portion 45 . As a result, by positioning the welded portion 50 at the portion that becomes the folded portion 45 of the convex portion 43 and the concave portion 44 formed in a T-shaped contour shape, the force in the direction in which the joint sides 40 are separated from each other in the circumferential direction is generated. Even if it acts, it is possible to suppress the occurrence of tensile stress in the welded portion 50 and to suppress the breakage of the welded portion 50 .

In addition, in the thin cylindrical sleeve 30 according to the above-described embodiment, the joint side 40 has the convex portion 43 and the concave portion 44, and the bent portion 45 is formed in the convex portion 43 and the concave portion 44. Alternatively, the convex portion 43 and the concave portion 44 may not be formed. FIG. 15 is a modification of the thin cylindrical sleeve 30 according to the embodiment, and is an explanatory view showing a configuration in which the joint side 40 does not have the convex portion 43 and the concave portion 44 and the folded portion 45 is formed. For example, as shown in FIG. 15 , the joint side 40 is formed in a wavy shape by bending directions of the curved portions 42 alternately in the extending direction of the joint side 40 . may be formed. That is, the wave-shaped joining edge 40 is a folded portion where the extending direction of the joining edge 40 is folded back in the axial direction of the thin cylindrical sleeve 30 by greatly changing the extending direction of the joining edge 40 at the curved portion 42 . 45 may be formed.

Even if the joint side 40 does not have the convex portion 43 and the concave portion 44, the folding portion 45 is formed by greatly changing the extending direction of the joint side 40 at the curved portion 42, and is thus formed. The welded portion 50 may be positioned on the folded portion 45 . As a result, even when a force is applied in a direction in which the joint sides 40 are separated from each other in the circumferential direction, it is possible to suppress the occurrence of tensile stress in the welded portion 50 and to suppress the breakage of the welded portion 50 .

Further, in the above-described embodiment, the torque sensor 10 is connected to the stub shaft 87 and the pinion gear 88a, but the shaft member to which the torque sensor 10 is connected is other than the stub shaft 87 and the pinion gear 88a. good too. The torque sensor 10 may, for example, be connected to the steering shaft 82 and detect torque acting on the steering shaft 82 .

Although preferred embodiments of the present disclosure have been described above, the present disclosure is not limited to those described in the above embodiments. The configurations described as the embodiments and modifications may be combined as appropriate.

REFERENCE SIGNS LIST 10 torque sensor 20 input side rotor 30 thin cylindrical sleeve 31 end 33 inner peripheral surface 38 thin plate 40 joint side 40a convex side joint side 40b concave side joint side 41 straight portion 42 curved portion 43 convex portion 43a base 43b tip portion 44 concave portion 44a opening 44b bottom 45 folded portion 45a raised side folded portion 45b recessed side folded portion 50 welded portion 60 resin mold 70 output side rotor 80 steering device 81 steering wheel 82 steering shaft 85 lower shaft 87 stub shaft 88 steering gear 89 tie rod

Claims (6)

A thin plate is formed by bending a thin plate into a cylindrical shape, and the ends of the thin plate on both sides in the circumferential direction of the cylinder are used as joint sides, and the joint sides are welded to each other by a plurality of welding parts, and the shaft member is A press-fitted thin-walled cylindrical sleeve,
In the shape of the fitting boundary appearing on the joint sides on both sides of the thin plate, a folded portion, which is a portion in which the direction of the boundary becomes opposite by folding back in the axial direction of the cylinder, is formed on each of the joint sides. has in
At a position in the circumferential direction from the folded portion of one of the joint sides, and between a part of the one joint side and the folded portion of one of the joint sides, the folded portion of the other joint side is provided. The part is located and joined,
The welded portion is located at a position where compressive stress is generated at the joint side when the shaft member is press-fitted into the thin cylindrical sleeve. 2. The thin cylindrical sleeve according to claim 1, wherein said welded portion is located at said folded portion. 3. The thin cylindrical sleeve according to claim 1, wherein the folded portion has a portion with an inclination angle of 45 degrees or less in the circumferential direction with respect to the axial direction. The joint sides that are joined to each other are composed of a convex side joint side and a concave side joint side,
The protrusion-side joint side has a protrusion that protrudes in a direction approaching the recess-side joint side in a state of being joined to the recess-side joint side,
The recess-side joint side is recessed in a direction away from the protrusion-side joint side in a state of being joined to the protrusion-side joint side, and a recess into which the protrusion enters when joined to the protrusion-side joint side. has
4. The convex portion and the concave portion each have a portion where a compressive stress is generated when a force is applied in a direction in which the joint sides are separated from each other while the convex portion is in the concave portion. A thin-walled cylindrical sleeve according to item 1. The convex portion is formed to have a portion whose width in the axial direction is larger than the width in the axial direction at the base of the convex portion,
The joint side on the convex portion side is a portion of the convex portion formed to have a larger width than the base portion of the convex portion and the width in the axial direction at the position of the base of the convex portion. The folded portion is formed between
The recess is formed to have a portion whose width in the axial direction is larger than the width in the axial direction at the position of the opening of the recess,
The joint side on the side of the recess has the folded portion formed between the opening of the recess and a portion formed with a width larger than the width in the axial direction at the position of the opening. A thin-walled cylindrical sleeve according to claim 4. a shaft member that transmits rotational torque;
a thin cylindrical sleeve formed in a substantially cylindrical shape and into which the shaft member is press-fitted;
a detection member arranged around the thin cylindrical sleeve;
an arithmetic element that detects the rotational torque based on a change in inductance of a detection coil that detects movement of the detection member in a circumferential direction about the shaft member;
with
The thin cylindrical sleeve is
The thin plate is formed by bending into a cylindrical shape, and the joint sides are joined by welding with a plurality of welding parts, with the ends on both sides of the thin plate in the circumferential direction of the cylinder being the joint sides,
In the shape of the fitting boundary appearing on the joint sides on both sides of the thin plate, a folded portion, which is a portion in which the direction of the boundary becomes opposite by folding back in the axial direction of the cylinder, is formed on each of the joint sides. has in
At a position in the circumferential direction from the folded portion of one of the joint sides, and between a part of the one joint side and the folded portion of one of the joint sides, the folded portion of the other joint side is provided. The part is located and joined,
The torque sensor, wherein the welded portion is located at a position where compressive stress is generated at the joint side when the shaft member is press-fitted into the thin cylindrical sleeve.

Images