JP2012197862A - Rotary damper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotary damper capable of inhibiting communication between one chamber and the other chamber via an outer circumference of a shaft and suppressing wear and frictional force in a packing.SOLUTION: The rotary damper includes: an annular recessed part 11 provided in a casing 2 and facing both of a pressure chamber and an outer circumference of a shaft 1; a side seal 9 housed in the annular recessed part and forming a back pressure chamber P1 between itself and a packing 7; and a discharge passage communicating the back pressure chamber to the one chamber and the other chamber. The side seal receives the pressure of a chamber at a higher pressure in the one chamber and the other chamber and communicates the chamber in the higher pressure to the back pressure chamber, and is pressed by the pressure of the back pressure chamber to tightly adhere to a circumferential side face of the annular recessed part and to an axial end face 1c of a diameter-enlarged part 1b, thereby sealing a gap between the casing and the shaft, blocking communication between the one chamber and the other chamber via the outer circumference of the shaft. The discharge passage releases the pressure of the back pressure chamber to a chamber with a lower pressure in the one chamber and the other chamber and suppresses pressure retention in the back pressure chamber.

Description

  The present invention relates to an improvement of a rotary damper.

  Conventionally, in a rotary damper, a shaft, a pair of side panels that pivotally support the shaft while allowing rotation in the circumferential direction, and a case that is sandwiched between these side panels to form a pressure chamber therein. The vane is provided on the shaft and divides the pressure chamber into one chamber and the other chamber.

  Then, for example, when a rotational force is applied to the shaft from the outside, the rotary damper operates to reduce the one chamber while the vane moves in the pressure chamber with the rotation of the shaft, and expands the other chamber. A damping force that suppresses the rotation of the shaft is exhibited by applying resistance to the flow of oil moving from the one chamber to the other chamber with a damping valve (see Patent Document 1).

  In the above rotary damper, the one chamber and the other chamber are partitioned by the vane, but are interposed between the side surface between the vane of the shaft and the case, between the vane and the side panel, and further between the side panel and the shaft. If one chamber communicates with the other chamber, the pressure in the high-pressure chamber escapes to the low-pressure chamber, the flow rate passing through the damping valve decreases, and the desired damping force cannot be achieved. The case is provided with a seal that slides on the side surface between the vanes of the shaft, and the vane is provided with a seal that slides on the case and the side panel. By sliding the seal end of the bearing to the end of the bearing, the communication between the one chamber and the other chamber is cut off except for the passage provided with the damping valve (see Patent Document 1).

JP-A-10-122287

  In such a rotary damper, it is difficult to seal around the shaft with only the bearing, and finally the oil around the shaft is sealed with an oil seal provided outside the bearing. Since the one chamber and the other chamber communicate with each other through a minute gap between the shaft and the shaft, it is difficult to prevent pressure leakage from the high-pressure side chamber to the low-pressure side chamber with the above structure, and external torque is applied to the shaft. There is a delay in the generation response of the damping force with respect to the input, and if the rotational speed of the shaft is low, the damping force may be insufficient.

  In addition, since oil passes through a minute gap between the bearing and the shaft, a packing is provided between the shaft and the side panel to prevent leakage of the rotary damper outward from the bearing. However, the gap between the bearing and the packing may enter the gap between the bearing and the shaft, and the gap may be accumulated, resulting in excessive pressure acting on the packing. When the structure is such that the tension force on the shaft is increased, the packing is excessively pressed against the shaft by the pressure and wears, and the frictional force generated between the packing and the shaft increases. There's a problem.

  Therefore, the present invention was devised to improve the above-described problems, and the object of the present invention is to prevent the communication between the one chamber and the other chamber through the outer periphery of the shaft and wear the packing. And a rotary damper capable of reducing the frictional force generated between the packing and the shaft.

  In order to solve the above-mentioned problems, the problem-solving means of the present invention includes a shaft provided with an enlarged diameter part in the middle, and supports the shaft while allowing rotation in the circumferential direction and forms a pressure chamber therein. Between the casing and the shaft, and a vane that is provided on the outer periphery of the enlarged diameter portion of the shaft and is slidably inserted into the casing to partition the pressure chamber into one chamber and the other chamber. A rotary damper provided with an annular packing that prevents leakage of working fluid to the outside of the casing, an annular recess provided in the casing and facing both the pressure chamber and the outer periphery of the shaft; A side seal that is housed in an annular recess and forms a back pressure chamber with the packing, and a discharge passage that communicates the back pressure chamber to the one chamber and the other chamber. The side seal receives the pressure on the high pressure side of the one chamber and the other chamber so that the chamber on the high pressure side communicates with the back pressure chamber, and is pressed by the pressure of the back pressure chamber, so that the peripheral side surface of the annular recess And close contact with the axial end surface of the diameter-enlarged portion to seal between the casing and the shaft to cut off the communication between the one chamber and the other chamber through the outer periphery of the shaft, The pressure of the chamber is released to the low pressure side of the one chamber and the other chamber to suppress the back pressure chamber from being crushed.

  According to the rotary damper of the present invention, in addition to preventing the communication between the one chamber and the other chamber through the outer periphery of the shaft and suppressing the wear of the packing, the frictional force generated between the packing and the shaft is reduced. Can be reduced.

It is a longitudinal cross-sectional view of the rotary damper in one embodiment. It is a cross-sectional view of the rotary damper in one embodiment. It is a top view of one side panel of the rotary damper in one embodiment. It is AA longitudinal cross-sectional view of one side panel and side seal of the rotary damper in one embodiment. It is a top view of the other side panel of the rotary damper in one embodiment. It is BB longitudinal cross-sectional view of the other side panel and side seal of the rotary damper in one embodiment. It is a perspective view of the side seal of the rotary damper in other embodiments. It is a perspective view of the side seal of the rotary damper in one modification of other embodiments. It is a top view of the side panel of the rotary damper in other modifications of other embodiments. It is a partial expanded perspective view of the shaft of the rotary damper in the other modification of other embodiment.

  The present invention will be described below based on the embodiments shown in the drawings. As shown in FIGS. 1 to 6, a rotary damper D according to an embodiment includes a shaft 1 and a casing that supports the shaft 1 while allowing the shaft 1 to rotate in the circumferential direction and forms a pressure chamber R therein. 2, a vane 6 provided in the shaft 1 and slidably inserted into the casing 2 to partition the pressure chamber R into one chamber R1 and the other chamber R2, and the casing 2 and the shaft 1 U packings 7 and 8 as annular packings that seal the gap and prevent leakage of the working fluid to the outside of the casing 2, and face both the pressure chamber R and the outer periphery of the shaft 1 provided in the casing 2. Annular recesses 11 and 12, side seals 9 and 10 housed in the annular recesses 11 and 12 to form back pressure chambers P 1 and P 2 between the packings 7 and 8, and the back pressure chamber 1, the pressure in the P2 is constituted by a discharge passage 13, 14 for discharging the low-pressure side of the hand chamber R1 and the other chamber R2. The rotary damper D exhibits a damping force that suppresses the rotation of the shaft 1 when the shaft 1 is rotated in the circumferential direction with respect to the casing 2.

  Hereinafter, each part of the rotary damper D will be described in detail. First, the shaft 1 includes a serration 1a that is provided at the tip and can be connected to a joint or the like (not shown), an enlarged diameter portion 1b that is larger in diameter than other portions provided in the middle, and an outer periphery of the enlarged diameter portion 1b. And a pair of vanes 6 and 6 provided with a phase of 180 degrees in the circumferential direction, and opened from the side portion between the vanes 6 and 6 of the enlarged diameter portion 1b and communicated between the opposite vanes 6 and 6 and each other. Two communication holes 15 and 16 that do not cross in the axial direction are provided. In addition, in the place mentioned above, although the serration 1a is provided for the coupling | bonding to the coupling etc. outside a figure, the connection method is not limited to this.

  As will be described in detail later, the casing 2 includes a case main body 3 having a hollow portion 31 and side panels 4 and 5 that are stacked and fixed on the case main body 3 in FIG. A pressure chamber R is formed inside, the shaft 1 is rotatably supported by the side panels 4 and 5, and the vanes 6 and 6 are inserted into the pressure chamber R so as to pass through the pressure chamber R. It is divided into one chamber R1 and the other chamber R2.

  The vane 6 has an arcuate surface at the tip, and slides on the upper end in FIG. 1 that contacts the side panel 4 in the casing 2, the tip that contacts the inner surface of the case body 3 in the casing 2, and the side panel 5 in the casing 2. A U-shaped seal 17 is attached to the lower end in FIG. 1, and this seal 17 is in sliding contact with the case body 3 and the side panels 4 and 5 in the casing 2 to seal between the vane 6 and the casing 2. is doing.

  The case body 3 includes a shell 30 having a hollow portion 31 forming a pressure chamber R, a valve block 32 provided on a side portion of the shell 30, and an upper end of the shell 30 in FIG. 1 and a plurality of screw holes 34 provided at intervals on the same circumference at the lower end of the shell 30 in FIG. 1.

  A side panel 4 is laminated above the case body 3 in FIG. 1, and a side panel 5 is laminated below the case body 3 in FIG. 1, and the shaft 1 is connected to the case body 3, the side panels 4, 4. When these are integrated while being inserted through 5, the hollow portion 31 of the shell 30 is sealed to form two fan-shaped pressure chambers R. These two pressure chambers R are each divided into a space L1 and a space L2 by a vane 6 provided on the shaft 1, and for example, fluid such as hydraulic oil is enclosed therein. Note that O-rings 41 and 42 surrounding the outer periphery of the hollow portion 31 are mounted between the shell 30 of the case body 3 and the side panels 4 and 5, and between the case body 3 and the side panels 4 and 5. Is sealed.

  In FIG. 2, the space L1 is defined on the left side of the vane 6 when viewed from the axis of the shaft 1, and the space L2 is defined on the right side of the vane 6 when viewed from the axis of the shaft 1. When the shaft 1 rotates clockwise, the spaces L1 are enlarged and the spaces L2 are reduced by the vanes 6. On the other hand, when the shaft 1 rotates counterclockwise in FIG. Is reduced and each space L2 is enlarged.

  Then, the spaces L1 in which the volumes are both expanded or reduced with the rotation of the shaft 1 are communicated with each other by the communication hole 15 of the shaft 1 to be one chamber R1, and similarly, the volumes are both increased with the rotation of the shaft 1. The space L2 to be expanded or contracted is communicated with the communication hole 16 of the shaft 1 to form the other chamber R2, and the one chamber R1 and the other chamber R2 are partitioned by the vane 6 as can be understood from the above description. The Further, the opening position of the communication hole 15 is provided at the root of the vane 6 so that the one chamber R1 is maintained in a communication state by the communication hole 15 even when the shaft 1 rotates. The other chamber R2 is provided at the base of the vane 6 so that the other chambers R2 are maintained in communication with each other even if the shaft 1 rotates.

  Returning, a damping passage 35 is provided from the shell 30 of the case body 3 to the valve block 32 to communicate the one chamber R1 and the other chamber R2, and the valve block 32 is disposed in the middle of the damping passage 35. A damping valve 36 that resists the flow while allowing only the flow of hydraulic oil from one chamber R1 to the other chamber R2, and a damping passage 35 that is disposed in parallel with the damping valve 36 and that is disposed from the other chamber R2 to the one chamber R1. A check valve 37 that allows only the flow of hydraulic fluid to be directed, and a hydraulic valve that is disposed in series with respect to the damping valve 36 in the middle of the attenuation passage 35 and only allows flow of hydraulic fluid from the other chamber R2 to the one chamber R1. However, a damping valve 38 that provides resistance to the flow, a check valve 39 that is disposed in the damping passage 35 in parallel with the damping valve 38 and allows only the flow of hydraulic oil from the one chamber R1 to the other chamber R2, And the accumulator 40 is provided which is connected between the middle and a in the damping valve 36 damping valve 38 of 衰通 passage 35.

  Therefore, when the shaft 1 rotates clockwise and the vane 6 compresses the other chamber R2, the hydraulic oil pushed out from the other chamber R2 passes through the damping valve 38 and the check valve 37 and expands through the damping passage 35. The damping valve 38 gives resistance to the flow of the hydraulic oil, causing a differential pressure between the other chamber R2 and the one chamber R1, thereby suppressing the rotation of the shaft 1. Demonstrate power.

  On the other hand, when the shaft 1 rotates counterclockwise and the vane 6 compresses the one chamber R1, the hydraulic oil pushed out from the one chamber R1 passes through the damping valve 36 and the check valve 39 and expands through the damping passage 35. It will move to the other chamber R2, and the damping valve 36 gives resistance to the flow of the hydraulic oil, so that a differential pressure is generated between the one chamber R1 and the other chamber R2, and the rotation of the shaft 1 is suppressed. Demonstrates damping force.

  A U-shaped seal 43 is attached to the upper and lower ends of the shell 30 on the inner periphery of the shell 30 of the case body 3 and in contact with the outer periphery of the enlarged diameter portion 1 b of the shaft 1. The seal 43, the seal 17 provided on the vane 6, the O-rings 41 and 42, and the side seals 9 and 10 accommodated in the annular recesses 11 and 12 of the side panels 4 and 5, other than the damping passage 35. One chamber R1 and the other chamber R2 do not communicate with each other.

  In the rotary damper D, the volume of the expansion or contraction of the one chamber R1 due to the rotation of the shaft 1 is equal to the volume of the contraction or expansion of the other chamber R2, so that the linear motion composed of the cylinder, piston and piston rod Unlike a single rod type damper, it is not necessary to compensate for the volume change in the cylinder. However, since it is necessary to compensate for the volume change of the fluid due to the temperature change, in this case, the volume change of the hydraulic oil, the accumulator 40 is installed. The volume change due to the temperature change of the hydraulic oil is compensated. In addition, the accumulator 40 applies a predetermined pressure to the sealed hydraulic fluid, and increases the apparent rigidity of the hydraulic fluid to improve the damping force generation response.

  Next, in this embodiment, as shown in FIGS. 1 to 4, the side panel 4 has a cylindrical shape, a shaft holding portion 4a through which the upper end of the shaft 1 is inserted, and a shaft holding portion 4a. A flange-shaped cap portion 4b provided on the outer periphery of the lower end in FIG. 1, a plurality of bolt insertion holes 4c provided in the cap portion 4b so as to coincide with the screw holes 33 of the shell 30 in the case main body 3, and a shaft holding An annular recess 11 provided on the inner periphery of the case body side of the portion 4a, a one-chamber passage 26 leading to the annular recess 11 from a portion facing the one chamber R1 at the case body-side end of the cap portion 4b, and a cap portion 4b, the other chamber passage 27 communicating with the annular recess 11 from the portion facing the other chamber R2 on the case body side end. The side panel 4 is laminated above the case body 3 in FIG. 1, and the bolts 44 passed through the bolt insertion holes 4 c are screwed into the screw holes 33 so that they are integrated. The number of bolts 44 required for strength may be used, and the number of bolt insertion holes 4c and screw holes 33 corresponding to the number of bolts 44 may be provided.

  Further, on the inner periphery of the shaft holding portion 4a, a cylindrical bearing 18 that is slidably contacted to the upper side in FIG. 1 relative to the enlarged diameter portion 1b of the shaft 1 is mounted. An annular U-packing 7 as a packing that is slidably contacted with the outer periphery of the shaft 1 and an annular U-packing 7 disposed on the side opposite to the casing main body than the U-packing 7 are provided on the side opposite to the case main body in FIG. A dust seal 19 is attached, and an annular side seal 9 and a side opposite to the case main body 9 than the side seal 9 are disposed in an annular recess 11 provided on the case main body side below the bearing 18 in FIG. An annular taper ring 20 provided on the disc ring 21 and a disc spring 21 as a spring member that presses the taper ring 20 toward the side seal 9 are accommodated.

  And the annular recessed part 11 has faced both the pressure chamber R and the outer periphery of the said shaft 1, and the side seal 9 is accommodated inside. The side seal 9 abuts on the peripheral side surface 11 a of the annular recess 11 and the upper end surface 1 c of the enlarged diameter portion 1 b to form a back pressure chamber P 1 in the annular recess 11. The back pressure chamber P <b> 1 is disposed between the side seal 9 and the U packing 7 as a packing, and the pressure in the back pressure chamber P <b> 1 also acts on the U packing 7.

  Further, the U packing 7 can tightly seal the outer periphery of the shaft 1 by the inner peripheral lip 7a being pressed against the outer periphery of the shaft 1 by the action of the pressure in the back pressure chamber P1.

  The side seal 9 is provided with an inner peripheral tapered surface 9 a on the inner periphery so that the inner diameter of the end portion on the tapering side is large, and the taper ring 20 is located in the annular recess 11 and from the side seal 9. Provided on the back pressure chamber P1 side is provided with an outer peripheral tapered surface 20a on the outer periphery so that the outer diameter of the side seal side end is small, and the inner peripheral tapered surface 9a of the side seal 9 and the outer periphery of the taper ring 20 are provided. The taper surface 20a faces and is slidably contacted.

  Further, a disc spring 21 is interposed between the opposite side seal side end of the taper ring 20 and the bottom surface 11b of the annular recess 11, and presses the taper ring 20 toward the side seal 9 side.

  The biasing force of the disc spring 21 is pressed against the peripheral side surface 11a of the annular recess 11 against the side seal 9 because the inner peripheral tapered surface 9a of the side seal 9 and the outer peripheral tapered surface 20a of the tapered ring 20 are in contact with each other. It acts on the direction and the direction pressed against the upper end surface 1c of the enlarged diameter portion 1b. Further, when the pressure in the one chamber R1 or the other chamber R2 becomes larger than the back pressure chamber P1 and the side seal 9 retreats against the biasing force of the disc spring 21, the side seal 9 and the enlarged diameter portion 1b. The back pressure chamber P1 communicates with the one chamber R1 or the other chamber R2, and the pressure on the high pressure side of the one chamber R1 and the other chamber R2 is increased in the back pressure chamber P1. It has come to be guided.

  When the pressure on the high pressure side of the one chamber R1 and the other chamber R2 acts in the back pressure chamber P1, the back pressure (pressure in the back pressure chamber P1) 11a and the direction of pressing against the upper end surface 1c of the enlarged diameter portion 1b. Therefore, the outer periphery of the side seal 9 is tightly contacted with the peripheral side surface 11a of the annular recess 11 by being pressed by the back pressure. In FIG. 4, the side surface of the case main body, which is the lower surface, is in close contact with the upper end surface 1 c of the enlarged diameter portion 1 b of the shaft 1, seals between the casing 2 and the shaft 1, and the one chamber R 1 and the other chamber R 2 around the shaft 1. To prevent communication. The taper ring 20 and the disc spring 21 as a spring member are provided in advance for positioning and preloading the side seal 9 in the annular recess 11, and the rotary damper D is slow even if the rotational speed of the rotary damper D is slow. The first chamber R1 and the other chamber R2 can be reliably prevented from communicating with each other by sealing the shaft 1 from the beginning of the operation. However, these can be omitted, and in this case, the inner circumference of the side seal 9 can be omitted. The tapered surface 9a need not be provided. Further, the spring member is not limited to the disc spring 21, and a wave washer or other spring or elastic body can be used.

  In turn, in the case of this embodiment, the opening on the one chamber R1 side of the one chamber passage 26 is a one-side relief provided with a one-side plate-like valve body 28b screwed to the cap portion 4b of the side panel 4 by a screw 28a. The valve 28 opens and closes. One side plate-like valve body 28b is given an initial deflection, and a valve opening pressure is set. The opening on the annular recess 11 side of the one-chamber passage 26 communicates with the back pressure chamber P1 formed by the side seal 9, and the one-side relief valve 28 controls the pressure in the back pressure chamber P1 to the pressure in the one chamber R1. When the pressure difference exceeds the valve opening pressure, the one chamber passage 26 is opened to release the pressure in the back pressure chamber P1 to the one chamber R1, but the flow from the one chamber R1 to the back pressure chamber P1 is prevented. Thus, only the flow from the back pressure chamber P1 toward the one chamber R1 is allowed. The one-side relief valve 28 is provided outside the movable range of the vane 6, that is, outside the range in which the vane 6 swings in the pressure chamber R as the shaft 1 rotates (the range indicated by the oblique lines in FIG. 3). Therefore, even if the shaft 1 rotates, the one-side relief valve 28 does not come into contact with the vane 6 so that the rotation of the shaft 1 is not hindered.

  In the case of this embodiment, the opening on the other chamber R2 side of the other chamber passage 27 is the other-side relief valve provided with the other-side plate-like valve body 29b that is screwed to the cap portion 4b of the side panel 4 with a screw 29a. 29 is opened and closed. The other side plate-shaped valve body 29b is given an initial deflection and a valve opening pressure is set. The opening on the annular recess 11 side of the other chamber passage 27 communicates with a back pressure chamber P1 formed by the side seal 9, and the other side relief valve 29 causes the pressure in the back pressure chamber P1 to be equal to the pressure in the other chamber R2. When these differential pressures reach the valve opening pressure, the other chamber passage 27 is opened to release the pressure in the back pressure chamber P1 to the other chamber R2, but the flow from the other chamber R2 toward the back pressure chamber P1 is prevented. Thus, only the flow from the back pressure chamber P1 toward the other chamber R2 is allowed. The other side relief valve 29 is also provided outside the movable range of the vane 6, that is, outside the range in which the vane 6 swings in the pressure chamber R as the shaft 1 rotates (the range indicated by the oblique lines in FIG. 3). Thus, even if the shaft 1 rotates, the other-side relief valve 29 does not come into contact with the vane 6 so that the rotation of the shaft 1 is not hindered.

  In the one-side relief valve 28, the pressure in the back pressure chamber P1 into which the pressure in the other chamber R2 on the high-pressure side is introduced is high in the one-chamber R1 and the other chamber R2. When the differential pressure between the back pressure chamber P1 and the one chamber R1 reaches the valve opening pressure, the pressure in the back pressure chamber P1 is released to the one chamber R1 and the back pressure chamber P1 is prevented from being overwhelmed. The opening pressure of the one-side relief valve 28 is set to such an extent that the pressure acting on the U-packing 7 by the rotary damper D is not excessive, and the valve is opened when the rotational speed of the shaft 1 is low and from the other chamber R2. By preventing the pressure from escaping to the chamber R1, it is possible to prevent the back pressure chamber P1 from crushing while preventing a delay in the generation response of the damping force. Similarly, in the other side relief valve 29, the pressure in the back pressure chamber P1 into which the pressure in the one chamber R1 on the high pressure side is introduced while the other chamber R2 is on the low pressure side among the one chamber R1 and the other chamber R2. When the pressure increases and the differential pressure between the back pressure chamber P1 and the other chamber R2 reaches the valve opening pressure, the pressure in the back pressure chamber P1 is released to the other chamber R2, and the back pressure chamber P1 is restrained from being crushed. Even if the opening pressure of the other-side relief valve 29 is set, the pressure that the rotary damper D acts on the U-packing 7 is set so as not to be excessive, and the shaft 1 is opened when the rotational speed of the shaft 1 is low. By preventing the pressure from escaping to the other chamber R2, it is possible to prevent the back pressure chamber P1 from crushing while preventing a delay in the generation response of the damping force. That is, the one-chamber passage 26 and the one-side relief valve 28, and the other-chamber passage 27 and the other-side relief valve 29 form the discharge passage 13. In this embodiment, the discharge passage 13 is In this way, the pressure in the back pressure chamber P1 is released to the low pressure side of the one chamber R1 and the other chamber R2, thereby suppressing the back pressure chamber P1 from being crushed.

  The one-side relief valve 28 and the other-side relief valve 29 open as soon as the valve opening pressure is reached and release the pressure in the back pressure chamber P1, but can exhibit the above-described operation to prevent the opposite flow. Although it is not limited to this, the side relief valve 28 and the side relief valve 29 are provided with plate-like valve bodies 28b and 29b that are screwed to the side panel 4 by screws 28a and 29a. Compared to a relief valve structure in which a valve body is provided inside the meat of the panel 4, there is an advantage that the side panel 4 can be made thinner and lighter and the complexity of the shape can be avoided. is there.

  In the case of this embodiment, the side panel 5 has a shaft holding portion 5a through which the bottom end in FIG. 1 of the shaft 1 is inserted, as shown in FIGS. 1, 2, 5 and 6, and A flange-shaped cap portion 5b provided on the outer periphery of the upper end in FIG. 1 of the shaft holding portion 5a, a plurality of bolt insertion holes 5c provided in the cap portion 5b so as to coincide with the screw holes 34 of the case body 30 described above, An annular recess 12 provided on the inner periphery of the shaft holding portion 5a on the case body side, a one chamber passage 51 communicating with the annular recess 12 from a portion facing the one chamber R1 on the case body side end of the cap portion 5b; It is provided with the other chamber passage 52 communicating with the annular recess 12 from a portion facing the other chamber R2 on the case body side end of the cap portion 5b. The side panel 5 is laminated below the case body 3 in FIG. 1, and the bolts 45 passed through the bolt insertion holes 5 c are screwed into the screw holes 34 so that they are integrated. The number of bolts 45 required for strength may be used, and the number of bolt insertion holes 5c and screw holes 34 corresponding to the number of bolts 45 may be provided.

  Further, on the inner periphery of the shaft holding portion 5a, a cylindrical bearing 53 that is in sliding contact with the lower side in FIG. 1 than the enlarged diameter portion 1b of the shaft 1 is mounted. An annular U-packing 8 as a packing slidably contacting the outer periphery of the shaft 1 is mounted on the side of the case opposite to the lower side in FIG. 1 from the bearing 53, and the case in the upper side in FIG. In the annular recess 12 provided on the main body side, an annular side seal 10, an annular taper ring 55 provided on the side opposite to the case main body from the side seal 10, and the taper ring 55 facing the side seal 10 side. A disc spring 56 as a spring member to be pressed is accommodated.

  And the annular recessed part 12 has faced both the pressure chamber R and the outer periphery of the said shaft 1, and the side seal 10 is accommodated inside as mentioned above. The side seal 10 abuts on the peripheral side surface 12 a of the annular recess 12 and the lower end surface 1 d of the enlarged diameter portion 1 b to form a back pressure chamber P <b> 2 in the annular recess 12. The back pressure chamber P <b> 2 is disposed between the side seal 10 and the U packing 8 as a packing, and the pressure in the back pressure chamber P <b> 2 also acts on the U packing 8.

  The side seal 10 is provided with an inner peripheral tapered surface 10 a on the inner periphery so that the inner diameter of the end portion on the tapering side is large, and the taper ring 55 is located in the annular recess 12 and more than the side seal 10. Provided on the back pressure chamber P2 side is provided with an outer peripheral tapered surface 55a on the outer periphery so that the outer diameter of the side seal side end is small, and the outer peripheral taper surface 55a and the inner peripheral tapered surface 10a of the side seal 10 The taper surface 55a is opposed to be slidable. A disc spring 56 is interposed between the opposite side seal side end of the taper ring 55 and the bottom surface 12b of the annular recess 12 to press the taper ring 55 toward the side seal 10 side.

  Furthermore, in the case of this embodiment, the opening on the one chamber R1 side of the one chamber passage 51 is a one-side relief valve provided with a one-side plate-like valve body 57b that is screwed to the cap portion 5b of the side panel 5 with a screw 57a. The door is opened and closed at 57. In the case of this embodiment, the opening on the other chamber R2 side of the other chamber passage 52 is the other-side relief valve 58 provided with the other-side plate-like valve body 58b screwed to the cap portion 5b of the side panel 5 by the screw 58a. It is designed to be opened and closed.

  Then, when the pressure in the back pressure chamber P2 exceeds the pressure in the one chamber R1 and the differential pressure reaches the valve opening pressure, the one side relief valve 57 opens the one chamber passage 51 to reduce the pressure in the back pressure chamber P2. Although it escapes to the one chamber R1, the flow from the one chamber R1 to the back pressure chamber P2 is prevented, and only the flow from the back pressure chamber P2 to the one chamber R1 is allowed. When the pressure in the back pressure chamber P2 exceeds the pressure in the other chamber R2 and the differential pressure reaches the valve opening pressure, the other side relief valve 58 opens the other chamber passage 52 to reduce the pressure in the back pressure chamber P2. Although escaped to the other chamber R2, the flow from the other chamber R2 toward the back pressure chamber P2 is prevented, and only the flow from the back pressure chamber P2 toward the other chamber R2 is allowed.

  Therefore, the annular recess 12, the side seal 10, the one chamber passage 51, the other chamber passage 52, the one side relief valve 57, and the other side relief valve 58 of the side panel 5 are respectively connected to the annular recess 11, The side seal 9, the one-chamber passage 26, the other-chamber passage 27, the one-side relief valve 28, and the other-side relief valve 29 are provided with the same configuration and exhibit the same actions and operations, respectively.

  Therefore, the pressure on the high pressure side of the one chamber R1 and the other chamber R2 is guided into the back pressure chamber P2, and the pressure in the back pressure chamber P2 causes the side seal 10 to be connected to the peripheral side surface 12a and the enlarged diameter portion 1b of the annular recess 12. Can be pressed against the lower end surface 1d to seal between the casing 2 and the shaft 1 and prevent communication between the one chamber R1 and the other chamber R2 around the shaft 1. Further, in the one-side relief valve 57, the pressure in the back pressure chamber P2 into which the pressure in the other chamber R2 on the high pressure side is introduced is high in the one chamber R1 and the other chamber R2. When the differential pressure between the back pressure chamber P2 and the one chamber R1 reaches the valve opening pressure, the pressure in the back pressure chamber P1 is released to the one chamber R1, and the pressure of the back pressure chamber P2 is suppressed, and the other side relief valve 58 is released. Similarly, out of the one chamber R1 and the other chamber R2, the other chamber R2 is on the low pressure side, and the pressure of the back pressure chamber P2 into which the pressure of the one chamber R1 on the high pressure side is introduced is increased, When the differential pressure between the back pressure chamber P2 and the other chamber R2 reaches the valve opening pressure, the pressure of the back pressure chamber P2 is released to the other chamber R2, and the back pressure chamber P2 is prevented from being overwhelmed.

  That is, the one-chamber passage 51 and the one-side relief valve 57, and the other-chamber passage 52 and the other-side relief valve 58 form the discharge passage 14. In this embodiment, the discharge passage 14 is In this way, the pressure in the back pressure chamber P2 is released to the low pressure side of the one chamber R1 and the other chamber R2, thereby suppressing the back pressure chamber P2.

  As described above, in the rotary damper D, the back pressure chambers P1 and P2 are formed by the side seals 9 and 10 accommodated in the annular recesses 11 and 12, and when the shaft 1 drives the rotary damper D, That is, when the shaft 1 rotates with respect to the casing 2, the pressure on the high pressure side compressed in the one chamber R1 and the other chamber R2 is introduced into the back pressure chambers P1, P2, and the back pressure chamber P1, One side chamber around the shaft 1 can be tightly sealed between the casing 2 and the shaft 1 by pressing the side seals 9 and 10 against the side panels 4 and 5 and the shaft 1 with pressure introduced into the P2. Communication between R1 and the other chamber R2 can be prevented.

  Further, when the pressure introduced into the back pressure chambers P1, P2 increases, the one-side relief valves 28, 57 or the other-side relief valves 29, 58 are opened so that the one-chamber passages 26, 51 or the other-chamber passages 27, 52 are opened. Since the pressure is released to the low pressure side of the one chamber R1 and the other chamber R2 through the pressure, it is possible to eliminate the crushing that the back pressure chambers P1, P2 are maintained at an excessively high pressure. That is, when the pressure in the back pressure chambers P1 and P2 becomes a high pressure that causes excessive pressure to act on the U packings 7 and 8, the discharge passages 13 and 14 reduce the pressure in the back pressure chambers P1 and P2 to the one chamber R1. The pressure is released to the low pressure side of the other chamber R2.

  As a result, while the side seals 9 and 10 prevent the communication between the one chamber R1 and the other chamber R2 through the outer periphery of the shaft 1, excessive pressure is applied to the one chamber R1 and the other chamber R2 in the discharge passages 13 and 14. By releasing the pressure to the low pressure side, it is possible to prevent the U packings 7 and 8 from continuing without being canceled while excessive pressure is applied to the U packings 7 and 8. It is possible to prevent the U-packings 7 and 8 from being strongly rubbed and worn significantly when the shaft 1 is rotated by being strongly tightened to the outer periphery of the shaft 1 by excessive pressure. Therefore, the rotary damper D of the present invention can suppress the wear of the U packings 7 and 8 as the packing while preventing the communication between the one chamber R1 and the other chamber R2 through the outer periphery of the shaft 1. . Moreover, since the wear of the U packings 7 and 8 as the packing can be suppressed, the life of the U packings 7 and 8 is extended. In addition, since the U packings 7 and 8 are prevented from being strongly tightened to the outer periphery of the shaft 1 by excessive pressure, the frictional force generated between the U packings 7 and 8 and the shaft 1 is reduced. be able to.

  In addition, in the place mentioned above, although the discharge passages 13 and 14 are comprised by the one chamber passages 26 and 51, the other chamber passages 27 and 52, the one side relief valves 28 and 57, and the other side relief valves 29 and 58, respectively. Instead of providing these, as shown in FIG. 7, grooves 9c (10c) are provided along the axial direction on the annular concave contact surface 9b (10b) which is the outer periphery of the side seal 9 (10). 9c (10c) forms a discharge passage, and when the outer periphery of the side seal 9 (10) contacts the peripheral side surface 11a (12a) of the annular recess 11 (12), the groove 9c (10c) functions as an orifice. You may make it leave. It is necessary to provide at least two grooves 9c and 10c for communicating the back pressure chambers P1 and P2 in both the one chamber R1 and the other chamber R2, but the side seals 9 and 10 are also rotated by the rotation of the shaft 1. Even so, the installation positions and the number of installations are geometrically optimized in accordance with the number of the spaces L1 and L2 so that the back pressure chambers P1 and P2 can be communicated with both the one chamber R1 and the other chamber R2. It is good to set to.

  By doing so, the side seals 9 and 10 are retreated in the annular recesses 11 and 12 by the pressure on the high pressure side of the one chamber R1 and the other chamber R2, and high pressure is introduced into the back pressure chambers P1 and P2. The operation is the same as the operation of the side seals 9 and 10 of the rotary damper D according to the embodiment described above. Therefore, even in the rotary damper D1 in this other embodiment, the pressure on the high pressure side of the one chamber R1 and the other chamber R2 is introduced into the back pressure chambers P1 and P2, and the back pressure chamber The side seals 9, 10 can be pressed against the side panels 4, 5 and the shaft 1 by the pressure introduced into the P 1, P 2 to tightly seal between the casing 2 and the shaft 1. The grooves 9c and 10c are arranged so that the back pressure chambers P1 and P2 are located on the low pressure side of the one chamber R1 and the other chamber R2 even if the outer periphery of the side seals 9 and 10 is in close contact with the peripheral side surfaces 11a and 12a of the annular recesses 11 and 12. However, since these grooves 9c and 10c function as orifices, the decrease in the pressure in the back pressure chambers P1 and P2 is first-order delayed from the pressure on the low pressure side of the one chamber R1 and the other chamber R2, When the rotation direction of the shaft 1 is alternately switched and a difference occurs between the pressures of the one chamber R1 and the other chamber R2, the pressure on the high pressure side is always introduced into the back pressure chambers P1 and P2, so that the sealing performance is impaired. Absent.

  When the rotary damper D1 stops operating, the pressure in the back pressure chambers P1 and P2 escapes to the one chamber R1 or the other chamber R2 through the grooves 9c and 10c, so that the back pressure chambers P1 and P2 have excessively high pressure. It is possible to eliminate the crushing that is maintained. That is, the grooves 9c and 10c function as discharge passages, and during the operation of the rotary damper D1, the pressure in the back pressure chambers P1 and P2 becomes a high pressure that causes excessive pressure to act on the U packings 7 and 8. However, when the operation is stopped, the pressure in the back pressure chambers P1, P2 is released to the one chamber R1 and the other chamber R2, so that this state is canceled while excessive pressure is applied to the U packings 7, 8. The U-packings 7 and 8 are strongly tightened to the outer periphery of the shaft 1 with excessive pressure, and the U-packings 7 and 8 are rubbed strongly during the rotation of the shaft 1 so that they are significantly worn. Can be prevented. Therefore, even in the rotary damper D1 of the present invention, the wear of the U packings 7 and 8 as packing is suppressed while preventing the communication between the one chamber R1 and the other chamber R2 through the outer periphery of the shaft 1. be able to.

  The grooves described above can be provided in addition to the outer periphery that is the annular recess contact surfaces 9b, 10b of the side seals 9, 10, for example, as shown in FIG. 8, the expansion of the shaft 1 of the side seal 9 (10). A groove 9e (10e) may be provided in the enlarged-diameter contact surface 9d (10d), which is a surface that contacts the diameter portion, or the annular recess contact surface 9b (10b) and the enlarged-diameter contact surface 9d. (10d) may be provided for both. Further, instead of providing the side seals 9 and 10, as shown in FIG. 9, a groove 11c (12c) may be provided on the peripheral side surface 11a (12a) of the annular recess 11 (12), as shown in FIG. As described above, the groove 1e (1f) may be provided in the upper end surface 1c (lower end surface 1d) which is the side seal contact surface of the enlarged diameter portion 1b of the shaft 1. As in the grooves 9c and 10c, at least two grooves 9e and 10e are required to communicate the back pressure chambers P1 and P2 in both the one chamber R1 and the other chamber R2. Depending on the number of spaces L1 and L2, the back pressure chambers P1 and P2 can be communicated with both the one chamber R1 and the other chamber R2 even if the seals 9 and 10 are rotated. It is better to set it to be optimal. When the grooves 11c and 12c are provided on the peripheral side surfaces 11a and 12a of the annular recesses 11 and 12, if a groove communicated with the one chamber R1 and a groove communicated with the other chamber R2 are provided outside the movable range of the vane 6, respectively. Good. Further, when the grooves 1e (1f) are provided in the upper end surface 1c (lower end surface 1d) which is the side seal contact surface of the diameter-expanded portion 1b of the shaft 1, as shown in FIG. By providing the grooves 1e and 1e respectively, the back pressure chamber P1 (P2) can be reliably transferred to the one chamber R1 and the other chamber R2 via the grooves 1e (1f) and 1e (1f) even if the shaft 1 rotates. Can communicate.

  Further, in the above description, the valve body 32 is provided in the case body 3 and the damping valves 36 and 38 are provided in the valve block 32. However, the damping passage, the check valve, and the damping valve are provided in the vane 6, and the accumulator is connected to the shaft. It is possible to eliminate the valve block by, for example, providing it within the shaft 1, and when there is no need to change the damping characteristic (the damping force characteristic with respect to the rotational speed of the shaft 1) in the rotational direction of the shaft 1, The damping force may be exerted by two damping valves.

  Furthermore, although the two vanes 6 are provided as described above, the number of installations may be one or three or more, and as long as an appropriate number is installed according to the specifications of the rotary dampers D and D1. Good. Moreover, in this Embodiment, although the case main body 3 is formed with the single components, you may be comprised with several components.

  This is the end of the description of the embodiment of the present invention, but the scope of the present invention is of course not limited to the details shown or described.

  The present invention can be used for a rotary damper for various purposes, for example, a rotary damper used for a vehicle suspension or the like.

DESCRIPTION OF SYMBOLS 1 Shaft 1b Expanded part 1c Upper end surface 1d of expanded part Lower end surface 1e, 1f, 9c, 9e, 10c, 10e, 11c, 12c Groove 2 Casing 3 Case main body 4, 5 Side panel 6 Vane 7, 8 U-packings 9 and 10 as packings Side seals 9a and 10a Inner circumferential tapered surfaces 9b and 10b Annular recess contact surfaces 9d and 10d Expanded-diameter contact surfaces 11 and 12 Annular recesses 11a and 12a Circumferential side surfaces 13 and 14 Discharge passage 20, 55 Taper rings 20a, 55a Peripheral tapered surfaces 21, 56 Disc springs 28, 57 as spring members One side relief valves 29, 58 The other side relief valves 28b, 57b One side plate valves 29b, 58b The other side plate valves D Rotary damper P1, P2 Back pressure chamber R Pressure chamber R1 One chamber R2 The other chamber

Claims (6)

A shaft provided with an enlarged diameter portion in the middle, a casing that supports the shaft while allowing rotation in the circumferential direction and forms a pressure chamber therein, and is provided on the outer periphery of the enlarged diameter portion of the shaft and the above A vane that is slidably inserted into the casing and divides the pressure chamber into one chamber and the other chamber, and an annular shape that seals between the casing and the shaft to prevent leakage of working fluid to the outside of the casing. In a rotary damper provided with a packing, an annular recess provided in the casing and facing both the pressure chamber and the outer periphery of the shaft, and a back pressure chamber disposed between the packing and received in the annular recess. A side seal to be formed; and a discharge passage for discharging the pressure in the back pressure chamber to the low pressure side of the one chamber and the other chamber. By receiving the pressure on the high pressure side of the other chamber, the chamber on the high pressure side is communicated with the back pressure chamber and is pressed by the pressure of the back pressure chamber to the peripheral side surface of the annular recess and the axial end surface of the enlarged diameter portion. Close contact and seal between the casing and the shaft to cut off the communication between the one chamber and the other chamber through the outer periphery of the shaft, and the discharge passage is configured to reduce the pressure of the back pressure chamber to the one chamber and the other chamber. A rotary damper characterized in that it escapes to the low pressure side of the chamber and suppresses the back pressure chamber from being crushed. A taper ring that is provided in the annular recess and closer to the back pressure chamber than the side seal, and has an outer peripheral tapered surface on the outer periphery so that the outer diameter of the side seal side end portion is a small diameter, and in the annular recess And a spring member that presses the tapered ring toward the side seal side, and an inner circumferential tapered surface is provided on the inner circumference of the side seal so that the inner diameter of the end portion on the tapered ring side is large. An inner circumferential tapered surface of the seal and an outer circumferential tapered surface of the taper ring are brought into contact with each other, and the pressure of the back pressure chamber is transmitted to the side seal through the taper ring so that the side seal is disposed on the circumferential side surface of the annular recess and 2. The rotary damper according to claim 1, wherein the rotary damper is pressed toward an end face in an axial direction of the enlarged diameter portion. The discharge passage is provided in the one-side chamber passage that communicates the back-pressure chamber and the one chamber, the other-chamber passage that communicates the back-pressure chamber and the other chamber, and the back-pressure chamber. A one-side relief valve that allows only the flow from the chamber toward the one chamber, and the other-side relief valve that is provided in the other chamber passage and allows only the flow from the back pressure chamber to the other chamber. The rotary damper according to claim 1 or 2, characterized by the above-mentioned. The one-side relief valve includes a one-side plate-like valve body that is fixed to the casing and opens and closes the outlet end on the one-chamber side of the one-chamber passage, and the other-side relief valve is fixed to the casing and The other-side plate-like valve body that opens and closes the outlet end on the other-chamber side of the other-chamber passage is provided, and the one-side plate-like valve body and the other-side plate-like valve body are provided outside the movable range of the vane. The rotary damper according to claim 3. 3. The rotary according to claim 1, wherein the discharge passage is a groove functioning as an orifice formed in one or both of an annular concave contact surface and an enlarged diameter contact surface of the side seal. damper. 3. The rotary according to claim 1, wherein the discharge passage is a groove functioning as an orifice formed in one or both of a peripheral side surface of the annular recess and a side seal contact surface of the enlarged diameter portion. damper.

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