JP7090437B2 - Spherical joint and damping device using this - Google Patents

Description

The present invention relates to a spherical joint used when a damping device such as a rotary inertia mass damper is attached to a structure such as a building.

As a damping device for quickly converging the vibration acting on the structure, as disclosed in Patent Document 1, a device using a ball screw device is known. This damping device has a rod having a spiral male screw and one end of which is connected to the structure, a nut member screwed to the rod, and a holding that rotatably supports and fixes the nut member to the structure. It includes a cylinder and a rotary weight that is given rotation by the nut member. The rod and the nut member constitute a ball screw device, and when the rod advances and retreats in the axial direction, the nut member rotates around the rod.

In such a damping device, when relative vibration generated in the structure due to an earthquake or the like is input between the rod and the holding cylinder, axial relative acceleration is generated in the rod along with the vibration, and the shaft thereof. The directional relative acceleration is converted into the angular acceleration of the nut member screwed into the rod. The nut member and the rotary weight integrally form a rotating body, and the rotational torque generated in the rotating body is represented by the product of the moment of inertia of the rotating body and the angular acceleration. Then, this rotational torque is reversely converted by the nut member and the rod each time the axial relative acceleration of the rod is reversed, and acts as an axial reaction force on the rod.

A spherical joint (ball joint) is provided at one end of the rod in order to allow the attitude (mounting angle) of the damping device to change with respect to the structure, and the damping device is connected to the structure via the spherical joint. Has been done. The spherical joint includes a spherical portion provided at the end of the rod and a bracket that rotatably holds the spherical portion and is fixed to the structure.

Further, in order to prevent the rod from being rotated by the rotational torque acting on the nut member, the spherical joint allows the precession movement of the rod while preventing the rotational movement in the axial direction. A stop mechanism is provided. This detent mechanism is composed of an elongated hole formed in the spherical surface of the spherical portion along the axial direction of the rod, and a regulation bolt having a tip portion inserted into the elongated hole through the bracket. ing.

JP-A-2017-26074

However, the detent mechanism of the spherical joint disclosed in Patent Document 1 allows the precession of the rod by moving the tip of the restricting bolt in the elongated hole formed in the spherical portion. The tip of the restricting bolt needs to be loosely fitted to the elongated hole, and it is difficult to eliminate the gap between the elongated hole and the restricting bolt in the rotation direction of the rod. Therefore, every time the rotation direction of the nut member changes, the restricting bolt collides with the inner wall of the elongated hole, which is disadvantageous in terms of strength. Further, since the elongated hole for inserting the tip of the regulation bolt is provided in the spherical portion, it is also disadvantageous in terms of strength in this respect.

Further, when the regulation bolt collides with the inner wall of the elongated hole, a sudden change in pulsed angular acceleration with respect to the rotation of the rotating body occurs with each collision, and the rotational torque of the rotating body is accompanied by this. Will fluctuate. Due to this sudden change in rotational torque, a sudden axial reaction force acts on the rod, and there is also a problem that the vibration generated in the structure cannot be smoothly damped.

The present invention has been made in view of such a problem, and an object of the present invention is that a damping device using a ball screw device can be easily connected to a structure, and the present invention is huge. It is an object of the present invention to provide a spherical joint which is advantageous in terms of strength in transmitting rotational torque.

That is, the spherical surface joint of the present invention has a spherical surface portion to which one end of the shaft member is fixed, and a holder having a concave spherical surface fixed to the structure and sliding in contact with the spherical surface portion of the spherical surface portion to wrap the spherical surface portion. It is provided with a detent member arranged between the spherical portion and the holder to lock the rotation of the spherical portion about the axis of the shaft member. The detent member has a first support shaft and a second support shaft that are orthogonal to the axis of the shaft member and exist on a plane passing through the rotation center of the spherical portion. The first support shaft and the second support shaft are provided along the radial direction of the spherical portion and their axes are orthogonal to each other, and the first support shaft is fitted into the first locking hole provided in the holder. On the other hand, the second support shaft is fitted in the second locking hole provided in the spherical portion. Then, in response to the precession of the shaft member centered on the spherical portion, the detent member swings with respect to the holder around the first support shaft, while the spherical portion swings with respect to the holder. Swings around the shaft with respect to the detent member

According to the spherical joint of the present invention, the detent member and the spherical portion swing with respect to the holder with the first support shaft and the second support shaft whose axes are orthogonal to each other as the center of rotation. It is possible to lock the rotary motion around the axis of the shaft member while allowing the differential motion, and it is possible to easily connect the damping device using the ball screw device to the structure.

Further, the first support shaft is fitted into the first locking hole of the holder, while the second support shaft is fitted into the second locking hole of the spherical portion, and these supports are fitted to these holders and the spherical portion. Since it is not necessary to provide an elongated hole into which the shaft is loosely fitted, it is advantageous in terms of strength in transmitting a huge rotational torque.

It is a schematic diagram which shows the mounting example of the damping device using the spherical joint of this invention. It is a perspective view which shows the 1st Embodiment of the damping device attached using the spherical joint of this invention. It is a perspective view which shows an example of embodiment of the spherical joint of this invention. It is a perspective view which shows an example of the detent member provided between a sphere part and a holder. It is a figure which shows the detail of the 1st locking hole provided in a holder. It is a partial cross-sectional view which shows the state which the detent member swings with respect to a holder. It is a partial cross-sectional view which shows the state which the sphere part oscillated with respect to the detent member. It is a perspective view which shows the 2nd example of the detent member provided between a sphere part and a holder. It is a perspective view which shows the 3rd example of the detent member provided between a sphere part and a holder. It is a schematic diagram which shows the 2nd Embodiment of the damping device attached using the spherical joint of this invention.

Hereinafter, the spherical joint of the present invention will be described in detail with reference to the accompanying drawings, and the damping device that can be attached to the structure using the spherical joint will be described in detail.

FIG. 1 shows an example of mounting an damping device using the spherical joint of the present invention on a structure. This dampening device is a first connecting portion 10 and a first fixed to separate parts (first structure S1 and second structure S2) in the system including structures such as buildings, towers, bridges and the like. The two connecting portions 11 are provided. The system including the structure means to include the foundation ground to which the structure is fixed. For example, except when the damping device is arranged inside the structure, the first connecting portion 10 is attached to the structure. , The second connecting portion 11 includes the case where it is fixed to the foundation ground.

A spherical joint 2 is provided in each of the first connecting portion 10 fixed to the first structure S1 and the second connecting portion 11 fixed to the second structure S2. As a result, the damping device 1 can freely adjust the connection angle with respect to the first structure S1 and the second structure S2, and the first structure S1 and the second structure S2 can be freely adjusted. When a relative vibration acts between them, the damping device 1 expands and contracts between the first structure S1 and the second structure S2 in response to the vibration. In FIG. 1, a pair of spherical joints 2 are provided at both ends of the damping device 1 in the longitudinal direction. For example, when both structures are not relatively displaced in the axial orthogonal direction of the damping device 1, the longitudinal direction is used. It is also possible to provide the spherical joint 2 only at one end and fix the other end directly to the first structure S1 or the second structure S2.

FIG. 2 is a perspective view showing a first embodiment of the damping device that can be attached to a structure using the spherical joint of the present invention, and is drawn by cutting out a part so that the internal structure can be grasped. The damping device 1 is a so-called rotary inertial mass damper, and has a fixed cylinder 12 having a hollow portion and formed in a cylindrical shape, and a spiral thread groove inserted into the hollow portion of the fixed cylinder 12 and having a spiral thread. The formed rod 13, the nut member 14 screwed into the thread groove of the rod 13 via a large number of balls, and the nut member 14 rotatably supported by the fixed cylinder 12 and coupled to the nut member 14. A cylindrical bearing housing 15, a cylindrical fly wheel 16 fixed to the bearing housing 15, and a rotor member rotatably supported by the fixed cylinder 12 and coupled to the fly wheel 16. It is equipped with 17. The rod 13 and the fixed cylinder 12 are connected to the structure via the spherical joint 2 and are restrained from rotating around the axis.

A bearing (not shown) is provided between the fixed cylinder 12 and the bearing housing 15, and the bearing housing 15 is rotatably supported with respect to the fixed cylinder 12. Further, the nut member 14 is fixed to one end of the bearing housing 15 in the axial direction, and when the nut member 14 rotates, the bearing housing 15 rotates with respect to the fixed cylinder 12 together with the nut member 14. It is configured in.

The rod 13 and the nut member 14 form a so-called ball screw device. The nut member 14 has an infinite circulation path for the large number of balls, and these balls roll in a spiral thread groove formed in the rod 13. As a result, it is possible to mutually convert the linear motion in the axial direction and the rotational motion around the rod 13 between the rod 13 and the nut member 14, and it is possible to mutually convert the linear motion in the axial direction with respect to the rod 13. When a linear motion is applied, the nut member 14 causes a rotary motion around the rod 13, while when a rotary motion is applied to the nut member 14, the rod 13 causes a linear motion in the axial direction.

A cylindrical flywheel 16 is provided on the outside of the bearing housing 15. The flywheel 16 is fixed to the bearing housing 15 and is configured to rotate integrally with the nut member 14 and the bearing housing 15. Further, since the bearing housing 15 can freely rotate with respect to the fixed cylinder 12, the flywheel 16 can also freely rotate with respect to the fixed cylinder 12.

On the other hand, the rotor member 17 is provided around the fixed cylinder 12. The rotor member 17 is supported on the outer peripheral surface of the fixed cylinder 12 via a rotary bearing and is coupled to the flywheel 16 via an end plate 18, and the fixed cylinder is connected with the rotation of the flywheel 16. It is configured to rotate around twelve. The inner peripheral surface of the rotor member 17 faces the outer peripheral surface of the fixed cylinder 12 via a slight gap, and the gap is a closed space for the viscous fluid. Therefore, when the rotor member 17 rotates, a shear resistance force acts from the viscous fluid between the outer peripheral surface of the fixed cylinder and the inner peripheral surface of the rotor member, and the energy of the rotational motion of the rotor member 17 is attenuated. It has become like.

Then, in the damping device 1 of the first embodiment, when a relative vibration acts between the first structure S1 and the second structure S2, the rod 13 is shafted with respect to the fixed cylinder 12. The damping device 1 expands and contracts in the direction, and the flywheel 16 and the rotor member 17 repeatedly invert around the fixed cylinder 12. When the flywheel 16 is reversed, a large rotational torque is generated by the rotational inertia of the flywheel 16, and this rotational torque acts as a reaction force with respect to the axial movement of the rod 13. Further, a shearing resistance force acts from the viscous fluid on the rotation of the rotor member 17, and this shearing resistance force also acts as a reaction force on the axial movement of the rod 13. As a result, the vibration acting between the first structure S1 and the second structure S2 is damped by the rotational inertia mass damper.

FIG. 3 is an exploded perspective view showing an example of a spherical joint to which the present invention is applied, and is drawn by cutting out a part to show the internal structure.

The spherical joint 2 encloses a spherical portion 21 having a through hole 20 into which a shaft member (not shown) fits, and the spherical surface of the spherical portion 21, and has a fixing bolt to form the first structure S1 or the second structure. It is provided with a holder 22 to be fastened to a structure such as the body S2. Further, the holder 22 includes a base member 23 having a bolt mounting hole 23a, and a lid member 24 fixed to the base member 23 and covering the spherical portion 21. An opening 24a is provided in the center of the lid member, and the shaft member is fitted into the through hole 20 of the spherical portion 21 through the opening 24a. The opening 24a limits the swing range of the shaft member with respect to the structure. The lid member 24 is fastened to the base member 23 using a fixing bolt (not shown), whereby the holder 22 is completed, but the means for integrating the lid member 24 and the base member 23 is bolt fastening. Not limited to this, welding or the like can also be used.

In this embodiment, the through hole 20 for fixing the shaft member is provided to the sphere portion 21, but the sphere portion and the shaft member are integrally formed without providing the through hole 20. A ball stud may be provided and the spherical portion of the ball stud may be wrapped in a holder.

Each of the base member 23 and the lid member 24 is provided with concave spherical surfaces 23b and 24b to which the spherical surface of the spherical surface portion 21 is in sliding contact. When the base member 23 and the lid member 24 are integrated with a coupling bolt (not shown), the spherical surface 21 is sandwiched between the concave spherical surface 23b of the base member 23 and the concave spherical surface 24b of the lid member 24, and the spherical surface 21 is the spherical surface portion 21. It is wrapped in the holder 22 and can rotate freely with respect to the holder 22.

An annularly formed detent member 25 is provided between the spherical portion 21 and the holder 22. The detent member 25 is orthogonal to the axis of the shaft member (indicated by a alternate long and short dash line in FIG. 3) fitted to the through hole 20 of the sphere portion 21 and is overlapped on a plane passing through the center of the sphere portion 21. It is provided and covers the vicinity of the equator of the sphere portion 21, that is, the maximum outer diameter portion of the sphere portion 21 from the outside. Further, the inner diameter of the detent member 25 is formed to be slightly larger than the maximum outer diameter of the sphere portion 21, and there is a slight gap between the inner peripheral surface of the detent member 25 and the spherical surface of the sphere portion 21. Is provided.

FIG. 4 is a perspective view showing the detent member 25. As shown in the figure, the detent member 25 is a metal flat plate formed into an annular shape, and a pair of first support shafts 26 are provided on the outer peripheral surface, while a pair of first support shafts 26 are provided on the inner peripheral surface. A second support shaft 27 is provided. The pair of first support shafts 26 and the pair of second support shafts 27 are provided along the radial direction of the spherical portion 21, and the axis of the first support shaft 26 and the axis of the second support shaft 27 are They are orthogonal to each other. The first support shaft 26 and the second support shaft 27 may be integrally formed with the detent member 25, or may be integrated with the detent member by screwing, welding, or the like.

The holder 22 is provided with a first locking hole 28 into which the first support shaft 26 is fitted, and the detent member 25 swings with respect to the holder 22 with the first support shaft 26 as the center of rotation. It is movable. Further, the spherical portion 21 is provided with a second locking hole 29 into which the second support shaft 27 is fitted, and the spherical portion 21 has the rotation prevention member 25 centered on the second support shaft 27. It is rotatable with respect to.

FIG. 5 is a diagram showing details of the first locking hole 28 provided in the holder 22. The first locking hole 28 is formed in an elongated hole shape with respect to the lid member 24 of the holder 22, and by fixing the lid member 24 to the base member 23, the first locking hole 28 is formed. 28 is closed, and the spacer 28a and the first support shaft 26 are contained inside the first locking hole 28. The spacer 28a, in combination with the first locking hole 28, encloses the first support shaft 26, whereby the first support shaft 26 is held in the first locking hole 28 in a rotatable state. Instead of providing the spacer 28a, the divided surfaces of the base member 23 and the lid member 24 of the holder 22 are aligned with the axis center of the first support shaft 26, and both the base member 23 and the lid member 24 are provided. A semi-cylindrical first locking hole may be provided.

FIG. 6 is a cross-sectional view showing the swing of the detent member 25 about the first support shaft 26 as the center of rotation. As shown in the figure, the holder 22 is provided with an annular groove 30 for accommodating the detent member 25. The annular groove 30 exists between the concave spherical surface of the base member 23 and the concave spherical surface of the lid member 24, and the groove width thereof is formed wider than the width of the detent member 25. When the detent member 25 swings with respect to the holder 22 with the first support shaft 26 as the center of rotation, the detent member 25 moves in the annular groove 30. That is, the groove width of the annular groove 30 limits the swing range of the detent member 25 with respect to the holder 22.

On the other hand, FIG. 7 is a cross-sectional view showing the swing of the spherical portion 21 with the second support shaft 26 as the center of rotation. As shown in the figure, the spherical portion 21 swings with respect to the detent member 25 with the second support shaft 27 as the center of rotation. The swing of the spherical portion 21 occurs independently of the swing of the detent member 25 centered on the first support shaft 26.

Therefore, as shown in FIG. 3, the axial direction of the through hole 20 of the spherical portion 21 is the Z direction, the axial direction of the first support shaft 26 is the X direction, and the axial direction of the second support shaft 27 is the Y direction. In this case, the detent member 25 swings with respect to the holder 22 with the X direction as the rotation center, while the spherical portion 21 swings with respect to the detent member 25 with the Y direction as the rotation center. By overlapping the movements of the detent member 25 and the spherical portion 21, the spherical portion 21 can freely swing in the X direction and the Y direction with respect to the holder 22, and the spherical portion 21 can be freely swung. It is possible to connect the shaft member to the structure while allowing the precession of the shaft member fitted in the through hole 20 of the above. At this time, since the spherical surface of the spherical surface 21 is in sliding contact with the concave spherical surfaces 23b and 24b provided on the holder, the load acting on the spherical surface 21 is directly applied by the holder 22 without going through the detent member 25. Is loaded.

On the other hand, since the first support shaft 26 and the second support shaft 27 are provided along the radial direction of the spherical portion 21 and surround the axis of the shaft member (the alternate long and short dash line in FIG. 3). The rotation of the spherical portion 21 around the axis is locked by the first support shaft 26 and the second support shaft 27. That is, even if a rotational torque acts on the shaft member connected to the spherical portion 21, the rotational torque is loaded by the first support shaft 26 and the second support shaft 27, and the shaft member rotates around the Z axis. It is connected to the holder 22 without any exercise.

Further, the first support shaft 26 fits into the first locking hole 28 provided in the holder 22 without moving with respect to the holder 22, while the second support shaft 27 fits into the spherical portion 21. Since it is fitted in the second locking hole 29 provided in the spherical portion 21 without moving with respect to the shaft member, even if a rotational torque that repeatedly reverses is applied to the shaft member, the first support shaft 26 and the shaft member 26 are fitted. The holder 22, the second support shaft 27, and the spherical portion 21 do not repeatedly collide with each other, and the bearing capacity is increased and the strength is increased as compared with the conventional spherical joint in which the spherical portion 21 has an elongated hole. It is advantageous in terms of.

When the damping device 1 is installed between the first structure S1 and the second structure S2 using the spherical joint 2 configured in this way, the shaft end of the rod 13 or the fixed cylinder 12 The shaft end of the sphere is fitted into the through hole of the spherical portion.

As shown in FIG. 1, when the above-mentioned damping device 1 is installed between the first structure S1 and the second structure S2 using a pair of spherical joints 2, the first structure S1 and the first structure S1 are installed. When a relative vibration acts between the two structures S2, the rod 13 causes a translational motion in the axial direction with respect to the fixed cylinder 12. A rotational torque acts on the nut member 14 screwed to the rod 13 with this translational motion, and as a reaction thereof, the rotational torque acting on the nut member 14 is the same as that of the rod 13. The rotational torque in the opposite direction acts.

At this time, the spherical joint 2 allows the precession of the rod 13 or the fixed cylinder 12 while locking the rotation of the rod 13 or the fixed cylinder 12 around the axis, so that the nut member 14 can be used. Rotation will occur according to the amount of movement of the rod due to the translational motion. As a result, in the damping device 1, rotation is transmitted from the nut member 14 to the flywheel 16 and the rotor member 17, and the vibration of the second structure S2 with respect to the first structure S1 is forcibly damped.

Then, in this spherical joint, in order to enable the precession of the rod 13 or the fixed cylinder 12, it is necessary to form an elongated hole in the spherical portion 21 or the holder 22 as in the conventional spherical joint. It is advantageous in terms of strength in the transmission of a huge rotational torque.

FIG. 8 is a perspective view showing a second example of the detent member, and FIG. 8 is a perspective view showing a third example of the detent member. As long as the detent member has the first support shaft 26 and the second support shaft 27, it does not need to be formed in an annular shape as in the detent member 25 shown in FIG. The detent member 25A shown in FIG. 8 has a pair of first support shafts 26 and a pair of second support shafts 27, and is formed in a substantially C shape. Further, the detent member 25B shown in FIG. 9 has one first support shaft and one second support shaft, and the detent members 25B are arranged in pairs so as to sandwich the spherical portion. In short, if the first support shaft 26 becomes the rotation center of the detent members 25A and 25B with respect to the holder 22, and the second support shaft 27 becomes the rotation center of the spherical portion 21 with respect to the detent members 25A and 25B. The shapes of the detent members 25, 25A, and 25B that support the first support shaft 26 and the second support shaft 27 can be arbitrarily changed in design.

FIG. 10 is a cross-sectional view showing a second embodiment of the damping device that can be attached to a structure using the spherical joint of the present invention.

This damping device 3 shows a damping device using a ball screw device as in the damping device 1 shown in FIG. 2, but does not have the flywheel 16 as described above, and has only the shear resistance force due to the viscous fluid. Damping the vibration acting between the first structure S1 and the second structure S2 is performed. The damping device 3 is formed in a cylindrical shape having a rod 31 having a male screw on the outer peripheral surface and having one end in the axial direction connected to the first structure S1 via the spherical joint 2, and a hollow portion. The fixed cylinder 32 connected to the second structure S2 via the spherical joint, screwed into the male screw of the rod 31 via a large number of balls, and rotatably supported by the fixed cylinder. It includes a nut member 33 and a cylindrical rotor member 34 that is housed in a hollow portion of the vessel fixing cylinder 32 and has the nut member 33 fixed to one end in the axial direction.

When the rod 31 advances and retreats in the axial direction with respect to the nut member 33 due to the vibration acting between the first structure S1 and the second structure S2 in the previous term, the nut member 33 moves back and forth with respect to the nut member 33. The axial motion of the member 31 is converted into a rotary motion, and the rotor member 34 fixed to the nut member 33 is repeatedly inverted with the rotational motion of the nut member 33.

The gap between the inner peripheral surface of the fixed cylinder 32 and the outer peripheral surface of the rotor member 34 is a viscous fluid accommodating chamber 35, and when the rotor member 34 rotates, the inner peripheral surface of the fixed cylinder 32 and the said. Shear resistance acts from the viscous fluid between the rotor member 34 and the outer peripheral surface. Since this shear resistance force acts as a reaction force with respect to the axial movement of the rod 31, the vibration acting between the first structure S1 and the second structure S2 is damped by the damping device 3. ..

Also in the damping device of the second embodiment, by connecting to the first structure S1 and the second structure S2 by using the spherical joint 2, the performance of the damping device using the ball screw device can be improved. It is possible to fully exert the effect and prevent damage to the damping device due to a large earthquake.

1 ... Damping device, 13 ... Rod, 14 ... Nut member, 2 ... Spherical joint, 21 ... Sphere part, 22 ... Holder, 25 ... Anti-rotation member, 26 ... First support shaft, 27 ... Second support shaft, 28 ... 1st locking hole, 29 ... 2nd locking hole

Claims (5)

A spherical part to which one end of the shaft member is fixed,
A holder that has a concave spherical surface that is fixed to the structure and is in sliding contact with the spherical surface of the spherical surface and that surrounds the spherical surface.
A detent member arranged between the sphere portion and the holder and locking the rotation of the sphere portion about the axis of the shaft member is provided.
The detent member exists on a plane orthogonal to the axis of the shaft member and passes through the center of rotation of the sphere portion, is provided along the radial direction of the sphere portion, and has a first support shaft whose axes are orthogonal to each other. And has a second support shaft,
The holder is provided with an annular groove that divides the concave spherical surface into two, and the detent member is housed in the annular groove.
A first locking hole into which the first support shaft is fitted is provided in the annular groove to communicate with the annular groove, while a second locking in which the second support shaft is fitted is provided in the spherical portion. A hole is provided,
In response to the precession of the shaft member centered on the spherical portion, the detent member swings with respect to the holder with respect to the first support shaft, while the spherical portion swings in the annular groove. A spherical joint characterized in that it swings with respect to the detent member about a second support shaft. The claim is characterized in that the detent member is formed in an annular shape surrounding the spherical portion, and the first support shaft is erected on the outer peripheral surface, while the second support shaft is erected on the inner peripheral surface. Item 1. The spherical joint according to item 1. The spherical joint according to claim 1, wherein the spherical portion has a through hole into which the shaft member is fitted. The spherical joint according to claim 1, wherein the spherical portion is provided integrally with the shaft member to form a ball stud. A rod in which a spiral thread groove is formed on the outer peripheral surface and at least one shaft end is connected to the first structure.
A nut member that is rotatably held with respect to the second structure, is screwed into the thread groove of the rod, and reciprocates in response to vibration of the second structure with respect to the first structure.
A damping means connected to the nut member to attenuate the reciprocating rotation of the nut member,
A spherical joint that connects the shaft end of the rod to the first structure is provided.
The spherical joint is
A spherical part to which one end of the rod is fixed, and
A holder that has a concave spherical surface that is fixed to the first structure and that is in sliding contact with the spherical surface of the spherical surface portion and that surrounds the spherical surface portion.
A detent member, which is arranged between the sphere and the holder and locks the rotation of the sphere about the axis of the rod, is provided.
The detent member exists on a plane orthogonal to the axis of the rod and passes through the center of rotation of the sphere, is provided along the radial direction of the sphere, and has a first support axis whose axes are orthogonal to each other. Has a second support shaft,
The first support shaft is fitted into the first locking hole provided in the holder, while the second support shaft is fitted into the second locking hole provided in the spherical portion.
In response to the precession of the rod centered on the spherical portion, the detent member swings with respect to the holder around the first support shaft, while the spherical portion is centered on the second support shaft. A damping device characterized by swinging with respect to the detent member.

Images