JP2003206974A - Rotary oil damper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an oil damper implementing position detecting function with higher accuracy than conventional oil damper using a magnet. <P>SOLUTION: In the rotary oil damper, a shaft member 4 is assembled in a casing C to be relatively rotatable. A photo detector 15 is disposed one of a casing C side or the shaft member 4 side, and a light shielding portion 9 is disposed to the other of the casing side or the shaft member side. A detection optical path of the photo detector is opened or shielded according to a relative rotational position of the casing and shaft member. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary oil damper suitable for detecting the open / closed position of, for example, a toilet seat or a toilet lid.

[0002]

2. Description of the Related Art As a device of this kind, for example, Japanese Patent Laid-Open No. 2001
The rotary oil damper described in Japanese Patent Publication No. 87166 is conventionally known. In this conventional rotary oil damper, a permanent magnet is mounted on a shaft member side that rotates integrally with a toilet seat or a toilet lid of a toilet bowl, and a casing side. The magnetic sensor is built into. Then, the position where the magnetic sensor detects the magnetism of the permanent magnet is detected during the rotation process of the shaft member.

[0003]

Since the conventional rotary oil damper as described above uses the magnetism of the permanent magnet, very high mounting accuracy is required when mounting the permanent magnet on the shaft member. There was a problem that Because the magnetic force of the permanent magnet changes in inverse proportion to the square of the distance, if the mounting error increases, the detection accuracy of the magnetic detector becomes unstable, and in some cases the position cannot be detected. Because there is.

Further, the magnetic force of the permanent magnet has a large temperature gradient such that it weakens as the temperature rises. Therefore, the detection accuracy becomes unstable such that the position for detecting magnetism changes depending on the temperature condition. Further, since the permanent magnet is very brittle, it may be easily broken by a slight vibration or shock. If the permanent magnet is broken during the assembly work, the detection accuracy cannot be obtained, so it must be replaced. In addition to the replacement, in some cases, it may be necessary to redo the assembly work. The purpose of this invention is
It is an object of the present invention to provide a rotary oil damper that has high detection accuracy and is easy to assemble.

[0005]

SUMMARY OF THE INVENTION The present invention is premised on a rotary oil damper having a casing in which a shaft member rotatable relative to the casing is incorporated. And 1st invention provides a photodetector in either one of a casing side or a shaft member side, and provides a light shielding part in the other side, and a photodetector according to the relative rotation position of a casing and a shaft member. It is characterized in that the detection optical path is opened or shielded.

According to a second aspect of the present invention, a support member is provided at a position facing the end surface of the shaft member on the casing side, and the photodetector is provided on one of the facing surfaces of the shaft member and the support member. Is provided, and the light shielding portion is provided on the other surface side. When the light shield is provided on the support member side, the light shield may be provided integrally with the support member.

The third invention is characterized in that another electric system is controlled in accordance with an on / off signal for opening / closing the detection optical path of the photodetector. In the case of a toilet bowl, for example, the other electric system is a heater for heating the toilet seat.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION First Embodiment FIGS. 1 to 7
In the rotary oil damper shown in Fig. 1, the casing C is composed of the case body 1 and the cap 2, but the case body 1 is
A bearing hole 3 is formed in the bottom portion on one side, and the cap 2 is fitted in the opening on the other side. The shaft member 4 is incorporated into the case body 1 thus configured, and the shaft member 4 is formed with the shaft portion 4a, the rotating portion 4b, and the support portion 4c in order from the tip thereof. Then, the supporting portion 4c is rotatably inserted into the bearing hole 3, and the shaft portion 4a penetrates the bearing hole 5 formed in the cap 2 so that its tip is projected to the outside of the case body 1. That is, the shaft member 4 includes the bearing hole 5 on the cap 2 side and the case body 1
It is rotatably supported between the side bearing hole 3.

In the figure, reference numerals 6 to 8 are all seal members, 6 is a seal member between the case body 1 and the cap 2, 7 is a seal member between the bearing hole 5 and the shaft portion 4a, 8
Is a seal member between the bearing hole 3 and the support portion 4c.

In the shaft member 4 incorporated in the case body 1 as described above, the shaft end face inserted into the bearing hole 3 is exposed from the case body 1 to the outside, and the light shield portion 9 is provided on the shaft end face. There is. As shown in FIG. 2, the light shielding portion 9 is composed of a cylindrical convex portion 9a and the cylindrical convex portion 9a.
A notch 9b is formed in a part of a. Then, the cylindrical convex portion 9a is projected to the outside of the bearing hole 3. In the first embodiment, the light shielding portion 9 is formed integrally with the shaft member 4, but it goes without saying that they may be formed by separate members.

The case body 1 is also provided with bearing holes 3
A concave portion 10 having a circular opening shape is provided on the side, and a step portion 11 is formed on the inner circumference of the concave portion 10.
A disc-shaped substrate 12 is fitted into the recess 10 and the substrate 12 is pushed to a position where it abuts against the step 11. In the figure, reference numeral 13 is the recess 1
The anti-rotation convex portion formed in 0 fits into the anti-rotation concave portion (not shown) formed on the substrate 12, and functions to position the substrate 12 and to prevent rotation. Also,
Reference numeral 14 is an axis for stopping the substrate 12.

The photodetector 15 is provided on the inside of the substrate 12 as described above, that is, on the side surface facing the supporting portion 4c.
The photodetector 15 has a pair of leg pieces 15a and 15b opposed to each other, and light output from one leg piece 15a side is received by the other leg piece 15b side. The facing distance between the pair of leg pieces 15a and 15b corresponds to the rotation locus of the cylindrical convex portion 9a of the light shielding portion 9.

Therefore, when the shaft member 4 rotates and the cylindrical convex portion 9a rotates, the convex portion 9a enters between the leg pieces 15a and 15b. In other words, both legs 15
When the notch 9b is located between a and 15b, the detection optical path between both leg pieces 15a and 15b is opened, so that light passes between them. On the other hand, when the tubular convex portion 9a is located between the leg pieces 15a and 15b, the tubular convex portion 9a is located.
As a result, the detection optical path between the two leg pieces 15a and 15b is blocked, so that light does not pass between them.

Thus, according to the rotational position of the shaft member 4,
Light passes through or does not pass through both legs 15a and 15b of the photodetector 15. Whether the detection is turned off when the light passes or the detection is turned off when the light is blocked is determined by the substrate 1
It is determined by the circuit design of 2.

For example, FIGS. 4 (I) to (IV) show the opening / closing state of the toilet lid 16 of the toilet bowl, and FIGS.
(D) shows both leg pieces 15a, 15 when the toilet lid 1 is open.
The case where the cylindrical convex portion 9a is located between b and the detection is turned on is shown. FIGS. 6 (a) to 6 (d) show the cutout portion 9b between the leg pieces 15a and 15b when the toilet lid 1 is opened. Shows the case where is located and the detection is turned off.

That is, in the process shown in FIGS. 5A to 5D, when the toilet lid 16 is closed at 0 degrees, both leg pieces 15 are inserted.
The notch 9b is located between a and 15b, and the photodetector 15
The detection optical path is opened to maintain the detection off state. Then, when the toilet lid 16 is opened to, for example, θII degrees, both leg pieces 15
The cylindrical convex portion 9a enters between a and 15b, blocks the detection optical path of the photodetector 15, and is in the detection ON state. The detection ON state is maintained even when the toilet lid 16 is opened by θIII degrees or more.
On the other hand, after closing the toilet lid 16 from the open state, the toilet lid 1
By rotating 6 to the position of θI degrees, both leg pieces 15a, 15
The notch 9b is located between b, the detection optical path is opened again, and the detection is turned off.

On the other hand, in the process shown in FIGS. 6 (a) to 6 (d), when the toilet lid 16 is closed at 0 °, both leg pieces 15 are inserted.
The cylindrical convex portion 9a enters between a and 15b to block the detection optical path of the photodetector 15 and maintain the detection ON state. Then, when the toilet lid 16 is opened up to θII degrees, both leg pieces 15a, 1
The tubular convex portion 9a comes out from between 5b, and the notch 9
b is located, the detection optical path is opened, and the detection is turned off.
Then, even if the toilet lid 16 is opened by θIII degrees, the detection-off state is maintained. On the other hand, if the toilet lid 16 is closed after it has been opened, both leg pieces 1
The tubular convex portion 9a enters between 5a and 15b, the detection optical path is opened again, and the detection is turned on.

In any case, both leg pieces 1 of the photodetector 15
Whether the detection is turned off or the detection is turned on when the detection optical path between 5a and 15b is blocked depends on the application of the rotary oil damper and the circuit design of the substrate 12, and should be limited to either one. There is no technical necessity.

For example, when the toilet seat of the toilet bowl is heated by electric heat, electricity is applied when the person is sitting on the toilet seat to heat the toilet seat, and the power is turned off when the person is away from the toilet seat. In this way, the power is turned off when the person is away from the toilet seat,
That will save electricity. In the type of FIG. 5, a circuit for turning on the heater of the toilet seat in the detection-off state and turning off the heater in the detection-on state may be used.
In this type, a circuit for turning on the heater of the toilet seat when the detection is on and turning off the heater when the detection is off is sufficient.

Further, the shaft member 4 may be fixed to the controlled object, or the casing C may be fixed to the controlled object. That is, the casing C may be fixed and the shaft member 4 may be rotated, or the casing C may be fixed and the casing C may be rotated. However, when the casing C is fixed to the control target, it is better to provide the photodetector 15 on the end face side of the shaft member 4 and the light shielding portion 9 on the side facing the photodetector 15. This is because the lead wire R has to be pulled out from the photodetector 15 side, so it is better to connect the lead wire R to the non-rotating shaft member 4 side. Further, when the photodetector 15 is provided on the end face side of the shaft member 4 and the light shielding portion 9 is provided on the opposite side, the substrate 1 of FIG.
The second portion is used as a supporting member, and the light shielding portion is provided on this supporting member, and the substrate 12 is provided on the end surface of the supporting portion 4c.

The rotary oil damper according to the first embodiment is not limited in structure for exerting its damper effect, but an example thereof is shown in FIG. . That is, on the inner surface of the case body 1 in which the shaft member 4 is incorporated, partitioning protrusions 17 and 18 are formed on both sides on the diameter line. The tip portions of the partitioning convex portions 17 and 18 come into contact with the rotating portion 4b, and the interior of the case body 1 is partitioned into one fluid chamber 19 and the other fluid chamber 20 with this contact portion as a boundary. .

Further, the rotating portion 4b is provided with control convex portions 21 and 22 on both sides on its diameter line, and the flow concave portion 2 is provided at the tip thereof.
3 and 24 are formed. The control convex portion 2 thus configured
Valve members 25 and 26 having a concave cross-section are covered on 1 and 22. The valve members 25 and 26 have openings 27 and 28 formed on one side surface thereof, and the other side surface is closed without forming an opening portion. The control convex portion 2 thus configured
1, 22 and the valve members 25, 26 divide the fluid chamber 19 into the chamber 1
9a and 19b, and the fluid chamber 20 is divided into the compartments 20a and 2
Partition with 0b.

Now, when the rotating portion 4b rotates clockwise in the drawing, the flow concave portions 23, 24 of the control convex portions 21, 22 and the opening portions 27, 28 of the valve members 25, 26 coincide with each other to allow free flow. A permissible flow path is formed. Therefore, the branch office 19
The fluid in b and 20b flows into the compartments 19a and 20a.
At this time, the rotating portion 4b is in a freely rotating state. In other words, the toilet lid 16 fixed to the shaft portion 4a integrated with the rotating portion 4b is in a freely rotatable state. The situation in which the toilet lid rotates freely is when it is lifted by hand.

When the rotating portion 4b is rotated counterclockwise, the flow recesses 23, 24 are now closed by the valve members 25, 26.
Is blocked by the side of. When the rotating portion 4b further rotates in this state, the fluid in the compartment 19a is pushed out toward the compartment 20b through the gap between the partitioning convex portion 17 and the rotating portion 4b. On the other hand, the fluid in the compartment 20a is pushed out to the compartment 19b side through the gap between the partitioning convex portion 18 and the rotating portion 4b.

As described above, since the fluid passes through the gaps between the partitioning convex portions 17 and 18 and the rotating portion 4b, a pressure loss is generated there, and a damper effect is exerted on the rotation of the rotating portion 4b. The state in which the damper effect is exhibited is, for example, when the lifted toilet lid is lowered. If the damper effect is exerted in this way, the toilet lid 16 will slowly descend even if the hand is released.

In the first embodiment as described above, the rotation position of the shaft member 4 is detected by blocking or opening the detection optical path of the photodetector 15 with the light shielding portion 15 provided on the shaft member 4. Therefore, the detection accuracy can be significantly improved. Further, since the light shield 15 only needs to shield or open the detection optical path, the light shield 15 does not need to have a magnetic or electronic function. Therefore,
The cost can be reduced accordingly.

In the first embodiment, the light shielding portion 9 is composed of the cylindrical convex portion 9a and the cutout portion 9b. However, as shown in FIGS. The light shielding portion 9 is projected, and a shielding surface 9c is provided at a position deviated from the center of the light shielding portion 9. The leg pieces 15a and 15b of the photodetector 15 are located on the center line x so as to sandwich the light shielding portion 9. It may be provided in the. In this case, as shown in FIGS. 9A and 9B, the detection optical path of the photodetector 15 is blocked when the shielding surface 9c is orthogonal to the center line x. Further, as shown in FIGS. 10A and 10B, the detection optical path is opened when the shielding surface 9c becomes parallel to the center line x.

Further, as shown in FIGS. 11 to 13, the light shielding portion 9 is projected at the center of the supporting portion 4c, and the light shielding portion 9 is provided with a chevron-shaped shielding surface 9d, so that the leg piece of the photodetector 15 is provided. 15a and 15b may be located offset from the center line x. Also in this case, FIG.
As shown in (b), when the shielding surface 9d is retracted from the detection optical path, the detection optical path is opened. In addition, FIG.
As shown in (b), when the shielding surface 9d is located on the center line x, the detection optical path is shielded.

In the second embodiment shown in FIG. 14, the bottom side of the case body 1 is completely covered, and the photodetector 15 is provided on the side of the cap 2 fitted on the side opposite to the bottom side. is there. Further, the shaft member 4 incorporated in the case main body 1 has the shaft portion 4a, the rotating portion 4b, and the supporting portion 4c, which is similar to the first embodiment, but a flange is provided between the shaft portion 4a and the rotating portion 4b. The point that the portion 4d is formed is different from the first embodiment. The shaft member 4 has a support portion 4c rotatably supported in a bearing recess 29 formed in the bottom of the case body 1.

A seal member 30 is provided around the flange portion 4d to prevent fluid from leaking from the fluid chambers 19 and 20. On the other hand, the cap 2 has a concave portion 31 formed inside thereof and the cap 2
The shaft portion 4a of the shaft member 4 is passed through the bearing hole 32 formed in the above. Therefore, the shaft member 4 is rotatably supported by the bearing recess 29 and the bearing hole 32.

The substrate 12 is incorporated in the recess 31 of the cap 2 as described above, and the photodetector 15 is provided inside the substrate 12. The photodetector 15 includes a leg piece 15a having a light emitting function and a leg piece 15b having a light receiving function.
Is the same as that of the first embodiment. Further, on the side surface of the flange 4d facing the substrate 12,
The light shield 9 is formed. This light shielding portion 9 also has a cylindrical convex portion 9a and a cutout portion 9b, which is the same as in the first embodiment.

Therefore, when the shaft member 4 rotates, the relative position between the photodetector 15 and the cylindrical convex portion 9a or the notch 9b changes, and the on / off signal is detected in the same manner as in FIG. can do. In addition, also in the second embodiment, the shaft member 4 and the light shielding portion 9 are integrally formed, but as a matter of course, they may be configured by separate members as in the first embodiment. .

Further, similarly to the first embodiment, the shaft member 4
May be fixed to the controlled object, or the casing C may be fixed to the controlled object. That is, the shaft member 4 may be rotated, or the casing C may be rotated. However, when fixing the controlled object to the casing C, it is better to provide the photodetector 15 on the end surface 4f side of the shaft member 4 and the light shielding portion 9 on the side opposite to it. In the case of the first embodiment Is the same as. It is obvious that the end surface of the shaft member in the present invention includes not only the end surface of the entire shaft member 4 but also the portion that appears as a side surface. Further, the photodetector 15 is provided on the end face 4f side of the shaft member 4.
14 is provided and the light shielding portion 9 is provided on the side opposite thereto, the portion of the substrate 12 in FIG. 14 is used as a support member, the light shielding portion is provided on this support member, and the substrate 12 is provided on the end face of the support portion 4c. To be provided.

The third embodiment shown in FIG. 15 has a bearing recess 29 in the bottom of the case body 1 as in the second embodiment.
And the cap 2 is fitted on the side opposite to the bottom. The cap 2 has a boss 2a formed inside, and the boss 2a is fitted and fixed in the opening of the case body 1. Further, an annular convex portion 2b is formed inside the cap 2, and the annular convex portion 2b and the rotating portion 4 are formed.
A spacer 33 is interposed between the spacer 33 and b. Further, seal members 34 and 35 are provided on the outer side and the inner side of the annular convex portion 2b.

A concave portion 36 is provided outside the cap 2.
The substrate 12 is fitted in the opening of the recess, but in this embodiment, the photodetector 15 similar to that of the first embodiment is provided on the outer surface of the substrate 12.

On the other hand, the shaft portion 4a of the shaft member 4 has a substrate 12
The disk-shaped support member 37 facing the is fixed. In this support member 37, just as in the first embodiment,
Light-shielding portion 9 having tubular convex portion 9a and cutout portion 9b
Is provided. In addition, in the third embodiment,
Although the support member 37 and the light shielding portion 9 are integrally provided, it goes without saying that they may be formed by separate members.

In the third embodiment as described above, the rotation of the shaft member 4 causes the photodetector 9 and the photodetector 9 to rotate.
The relative position to the cylindrical convex portion 9a or the notch portion 9b changes, and the on / off signal can be detected in exactly the same manner as in FIG.

The shaft member 4 may be fixed to the controlled object, or the casing C may be fixed to the controlled object. That is, the shaft member 4 may be rotated or the casing C may be rotated, as in the first embodiment. However, when fixing the controlled object to the casing C, it is better to fix the substrate at the position of the support member 37 and the support member at the position of the substrate 12. This is because the lead wire R has to be pulled out from the photodetector 15 side, so it is better to connect the lead wire R to the non-rotating shaft member 4 side.

The fourth embodiment shown in FIGS. 16 and 17 is
The substrate 12 is provided on the casing C side in parallel with the axis, and both leg pieces 15 of the photodetector 15 provided on the substrate 12 are provided.
a and 15b are provided in a direction orthogonal to the axis. The shaft member 4 is further provided with a rotation convex portion 4e from the support portion 4c, and a light shielding portion 9 is provided at the tip of the rotation convex portion 4e. As is clear from FIG. 17, the light shielding portion 9 includes a disc portion 9e and a cutout portion 9f formed by cutting out the disc portion 9e.

The leg piece 15 of the photodetector 15 as described above
The a and 15b are positioned within the rotation locus of the disc portion 9e. Therefore, when the shaft member 4 rotates, the disc portion 9e or the cutout portion 9f is positioned between the leg pieces 15a and 15b. And both leg pieces 15a, 1
When the disc portion 9e is located between the 5b, the detection optical path of the photodetector 9 is blocked, and when the cutout portion 9f is located, the detection optical path is opened. Therefore, according to the fourth embodiment, the on / off signal corresponding to the rotational position of the shaft member 4 is detected, which is the same as the first embodiment.

In the fourth embodiment as well, the shaft member 4 and the light shielding portion 9 are integrally formed, but it goes without saying that they may be constituted by separate members. Further, the shaft member 4 may be fixed to the controlled object, or the casing C may be fixed to the controlled object. That is, the shaft member 4 may be rotated or the casing C may be rotated, as in the first embodiment. However, when the controlled object is fixed to the casing C, the substrate is fixed to the rotation convex portion 4e side and the light shielding portion 9 is fixed to the substrate 12 side.
It is better to fix. This is because the lead wire R has to be pulled out from the photodetector 15 side, so it is better to connect the lead wire R to the non-rotating shaft member 4 side.

The fifth embodiment shown in FIGS. 18 and 19 is
A bearing recess 29 is formed on the bottom of the case body 1, and the cap 2 is fitted on the side opposite to the bottom. The cap 2 has a boss 2a formed inside thereof,
The boss 2a is fitted and fixed in the opening of the case body 1. Further, an annular convex portion 2b is formed inside the cap 2, and a spacer 33 is interposed between the annular convex portion 2b and the rotating portion 4b. Further, seal members 34 and 35 are provided on the outer side and the inner side of the annular convex portion 2b. This point is the same as the second embodiment.

On the casing C side, a substrate 12 parallel to the axis is provided, and a photodetector 15 is provided on the substrate 12. The photodetector 15 has both leg pieces 15a and 15b provided in a direction orthogonal to the axis. On the other hand, the shaft member 4 is provided with a light shielding portion 9 on the shaft portion 4a. As is clear from FIG. 19, the light shielding portion 9 includes a disc portion 9e and a cutout portion 9f formed by cutting out the disc portion 9e.

The leg piece 15 of the photodetector 15 as described above
The a and 15b are positioned within the rotation locus of the disc portion 9e. Therefore, when the shaft member 4 rotates, the disc portion 9e or the cutout portion 9f is positioned between the leg pieces 15a and 15b. And both leg pieces 15a, 1
When the disc portion 9e is located between the 5b, the detection optical path of the photodetector 9 is blocked, and when the cutout portion 9f is located, the detection optical path is opened. Therefore, also in the fifth embodiment, the on / off signal corresponding to the rotational position of the shaft member 4 is detected, which is the same as in the first embodiment.

In the fifth embodiment, the shaft member 4 and the light shield 9 are formed separately, but it goes without saying that they may be integrated. Further, the shaft member 4 may be fixed to the controlled object, or the casing C may be fixed to the controlled object. That is, the shaft member 4 may be rotated or the casing C may be rotated, as in the first embodiment. However, when fixing the controlled object to the casing C, it is better to fix the photodetector to the shaft member 4 side and the light shielding portion to the casing C side. This is because the lead wire R must be pulled out from the photodetector 15 side as in each of the embodiments, so it is better to connect the lead wire R to the non-rotating shaft member 4 side.

The use of each of the embodiments as described above is not limited to the toilet seat of the toilet bowl, etc., as described above.
In short, the oil damper can be applied to any field as long as it controls the electric system of another device according to the moving position of the controlled object that rotates or rotates.

[0047]

According to the oil damper of the present invention, the detection optical path of the photodetector is opened or blocked according to the relative rotational position between the casing and the shaft member.
Even if the facing distance between the photodetector and the shielding unit that opens or shields the detection optical path is slightly different, it does not affect the accurate signal detection. Further, since the detection optical path is only opened or blocked, the detection accuracy does not depend on the temperature environment.

Further, unlike the conventional case where a magnet is used, a measure against brittleness can be taken sufficiently, so that a defect does not occur in detection accuracy during an assembly process or a use process. Furthermore, since other electrical systems can be controlled according to the ON / OFF signal that opens and closes the optical path of the photodetector,
The control accuracy can be improved.

[Brief description of drawings]

FIG. 1 is a sectional view of a first embodiment.

FIG. 2 is a sectional view taken along line II-II in FIG.

FIG. 3 is a side view of the casing with the substrate of FIG. 1 removed.

4 (I) to (IV) show the opening / closing state of the toilet lid of the toilet bowl.

5 (a) to (d) show a case where a tubular convex portion is located between both leg pieces and detection is turned on when the toilet lid is open.

6 (a) to (d) show a case where a notch portion is located between both leg pieces and detection is turned off when the toilet lid is open.

7 is a cross-sectional view taken along line VV of FIG.

FIG. 8 is a perspective view of a main part showing another embodiment of the light shielding part.

9A is a side view showing a state in which a detection optical path is shielded, and FIG. 9B is a sectional view thereof.

10A is a side view showing a state in which a detection optical path is opened, and FIG. 10B is a sectional view thereof.

FIG. 11 is a perspective view of a main part showing another embodiment of a light shielding part.

12A is a side view showing a state in which a detection optical path is opened, and FIG. 12B is a sectional view thereof.

13A is a side view showing a state in which a detection optical path is shielded, and FIG. 13B is a sectional view thereof.

FIG. 14 is a cross-sectional view showing a second embodiment.

FIG. 15 is a cross-sectional view showing a third embodiment.

FIG. 16 is a sectional view showing a fourth embodiment.

FIG. 17 is a side view.

FIG. 18 is a cross-sectional view of the fifth embodiment.

FIG. 19 is a side view.

[Explanation of symbols]

C casing 4 shaft members 9 Light shield 15 Photodetector 37 Support member

Claims (3)

[Claims] 1. A rotary oil damper comprising a shaft member that is rotatable relative to the casing in a casing, wherein a photodetector is provided on either the casing side or the shaft member side, and a photodetector is provided on the other side. A rotary oil damper, which is provided with a shielding portion and is configured to open or shield the detection optical path of the photodetector according to the relative rotational position between the casing and the shaft member. 2. A support member is provided at a position facing the end surface of the shaft member on the casing side, and a photodetector is provided on either one of the facing surfaces of the shaft member and the support member. The light shielding portion is provided on the other surface side.
Rotating oil damper described. 3. The rotary oil damper according to claim 1, wherein another electric system is controlled according to an on / off signal for opening / closing a detection optical path of the photodetector.