JP2011122635A - Torsional damper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a torsional damper, capable of effectively damping various torsional vibrations with different amplitudes or frequency bands. <P>SOLUTION: The torsional damper 1 includes a main cylinder 2 connected to one rotator 301 of an input-side rotator 301 and an output-side rotator 303 which are twisted by relative rotation; a main piston 3 provided slidably within the cylinder 2 and connected to the other rotator 303; a through-hole 3a formed in the main cylinder 3; and a fluid 7 filled in the main cylinder 2, in which torsional vibration is damped by a flowing resistance force in passage of the fluid 7 through the through-hole 3a. The torsional damper further includes a sub-cylinder 4 formed within the main piston 3, a sub-piston 5 provided slidably within the sub-cylinder 4 and connected to the other rotator 303, and a damping force adjustment mechanism 10 which regulates relative movement between the main piston 3 and the sub-piston 5 according to torsion and centrifugal force. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a torsional damper that is attached to a rotating member and attenuates torque fluctuation or torsional vibration.

  For example, a spring or pendulum is attached to the vibration system of a rotating member that generates torque fluctuation or torsional vibration caused by torque fluctuation, such as a crankshaft of a vehicle engine or an input shaft or drive shaft of a transmission. Damper devices such as torsional dampers and dynamic dampers that absorb or attenuate vibrations of the vibration system are widely used.

  One example thereof is described in Patent Document 1. The dynamic damper described in Patent Document 1 includes an annular damper case that is attached to a rotating body so as not to be relatively rotatable, a damper chamber that is a sealed space formed in the damper case, and a diameter of the damper chamber. And a weight member installed so as to partition in the direction. The damper chamber is partitioned by the weight member so as to be adjacent to the inner side in the radial direction of the weight member and sealed with a predetermined compressive fluid, and adjacent to the outer side in the radial direction of the weight member. And an outer space in which a predetermined compressive fluid is sealed is formed, and the weight member is configured such that its center of gravity is held movably in the radial direction by centrifugal force.

  In Patent Document 2, the first rotating body and the second rotating body provided so as to be relatively rotatable around a common axis, and the circumferential direction with respect to each of the first rotating body and the second rotating body. An intermediate member provided so as to be relatively displaceable, a pair of elastic bodies disposed between the intermediate member and the first rotating body and the second rotating body so as to sandwich the intermediate member, and a first rotating body, Friction generating means for generating friction with respect to the relative rotation between the second rotating body, a release position that allows relative rotation between the rotating body of either the first rotating body or the second rotating body and the intermediate member; It has a connecting member that can move between one rotating body and a connecting position that connects the intermediate member so as not to be relatively rotatable, and when the centrifugal force acting on the connecting member is large, the connecting member is moved to the connecting position. When the centrifugal force is small, release the connecting member A coupling switching mechanism for moving each of which describes a damper device provided in location.

  Further, Patent Document 3 discloses a damper mount for connecting a damper device of a vehicle suspension to a vehicle body. The damper mount is disposed between the damper device and the vehicle body, and one side is connected to the damper device, and the other side is connected. A damper mount having a rubber bush connected to a vehicle body and an actuator that elastically deforms the rubber bush to change the apparent spring constant of the rubber bush is described.

JP 2008-115914 A JP 2009-150471 A JP 2009-227200 A

  In the damper device described in Patent Document 1, centrifugal force acts on the weight member of the damper device when the rotating body rotates, and the weight member moves to the outer peripheral side in the radial direction by the centrifugal force. When the weight member moves in the radial direction and the position of the center of gravity changes, the spring constant of the dynamic damper changes, and as a result, the natural frequency of the dynamic damper changes. Therefore, according to the damper device described in Patent Document 1, the natural frequency of the dynamic damper can be appropriately changed according to the rotational speed of the rotating body, that is, according to the magnitude of the acting centrifugal force. Even a rotating body having a wide rotation speed range can effectively suppress vibration.

  However, in the damper device described in Patent Document 1, when the rotational speed of the rotating body varies, the natural frequency of the damper apparatus can be changed according to the rotational speed of the rotating body. The vibration absorption performance or vibration damping performance of the device is uniform. Therefore, the vibration absorbing performance or vibration damping performance of the damper device may not be sufficient for torsional vibration in a specific frequency range that occurs in a specific rotation speed range of the rotating body.

  Further, for example, in a conventional damper device provided with a lock-up clutch in a torque converter of a vehicle equipped with an automatic transmission, for example, as shown in FIG. 6, the damper has a low spring constant and low hysteresis (see FIG. 6). (Solid line), the vibration transmission sensitivity of the drive system becomes lower in the low-rotation operating range of the engine compared to a damper having a high spring constant (broken line in FIG. 6), and so-called engine noise can be suppressed. . On the other hand, when the damper has a low spring constant and low hysteresis, the primary resonance frequency of the drive system is lower and the vibration transmission sensitivity of the drive system is higher than that of a damper with a high spring constant. When the engine speed fluctuates, a transient shock tends to occur.

  As described above, in the conventional damper device for the torsional vibration of the rotating body, there is still room for improvement in order to absorb or attenuate the torsional vibration of the rotating body more effectively corresponding to a wide range of rotational speeds. .

  The present invention has been made paying attention to the above technical problem, and an object thereof is to provide a torsional damper capable of effectively absorbing or attenuating various torsional vibrations having different amplitudes and frequency ranges. To do.

  In order to achieve the above object, the invention according to claim 1 is directed to a main cylinder coupled to one of an input side rotating body and an output side rotating body that is twisted by relative rotation, and the inside of the main cylinder. The main piston is slidably provided so as to divide the interior into two chambers, and is connected to either one of the rotating bodies, and the main piston is formed so as to communicate with the two chambers. A torsional damper having a through hole formed therein and a fluid filled in the main cylinder, the flow resistance acting when the fluid flows through the through hole acting as a resistance against the relative rotation A sub-cylinder formed inside the main piston, a sub-piston slidably provided inside the sub-cylinder and connected to the other rotating body, and the torsional magnitude And it is characterized in that it comprises a damping force adjusting mechanism for restricting the relative movement between the main piston and the secondary piston in response to the magnitude of the centrifugal force acting spare.

  The invention according to claim 2 is the invention according to claim 1, wherein the damping force adjusting mechanism causes the centrifugal force to be larger when the twist is larger than a predetermined displacement or larger than a predetermined force. It includes means for restricting the relative movement when force is applied.

  The invention of claim 3 is characterized in that, in the invention of claim 2, the damping force adjusting mechanism includes means for strongly restricting the relative movement as the centrifugal force increases.

  According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the damping force adjusting mechanism has a rotation center of the rotating body on a pressure receiving surface of the sub piston facing the ceiling surface of the sub cylinder. The distance from the ceiling surface becomes narrower from the side toward the outer peripheral side, and the relative movement is restricted by abutting the ceiling surface when the twist is larger than a predetermined displacement set in advance. And the taper surface is enclosed between the ceiling surface and the taper surface in the sub cylinder, and the larger the centrifugal force, the more the outer peripheral side moves and abuts both the ceiling surface and the taper surface. And a mass body for restricting the relative movement.

  According to the first aspect of the present invention, the mechanism for absorbing the torsional vibration by the main cylinder and the main piston and the mechanism for absorbing the torsional vibration by the subcylinder and the subpiston are divided into the magnitude of the torsional vibration and the magnitude of the acting centrifugal force. It can be switched and functioned accordingly. Therefore, it is possible to effectively absorb or attenuate various torsional vibrations having different amplitudes and frequency ranges.

  According to the invention of claim 2, when the torsional vibration increases beyond a predetermined displacement or when the centrifugal force acting on the torsional damper exceeds a predetermined force, the gap between the main piston and the sub piston is increased. Relative movement is restricted, and the mechanism that absorbs torsional vibrations functions by the main cylinder and the main piston. As a result, for example, when a torsional vibration having a large displacement or amplitude occurs, or when a large centrifugal force acts on the torsional damper, that is, when the rotating body rotates at a high rotational speed, the sub cylinder and the sub piston relatively move. The main cylinder and the main piston can absorb the torsional vibration, which has higher vibration damping performance than the case of absorbing the torsional vibration. Therefore, in accordance with various torsional vibrations with different amplitudes and frequency ranges, the torsional vibrations can be absorbed or attenuated appropriately and effectively.

  According to the invention of claim 3, when the centrifugal force acting on the torsional damper exceeds a predetermined force, the relative movement between the main piston and the sub-piston becomes stronger as the centrifugal force increases. Regulated by Therefore, the torsional vibration generated at that time can be appropriately absorbed or attenuated according to the magnitude of the acting centrifugal force, that is, according to the number of rotations of the rotating body.

  According to the invention of claim 4, when the displacement of the generated torsional vibration is small and the acting centrifugal force is small, the mass body in the sub cylinder is closer to the rotation center of the rotating body, that is, the sub cylinder. Since the distance between the ceiling surface of the cylinder and the pressure receiving surface of the auxiliary piston is located on the wide side, the relative movement between the main piston and the auxiliary piston is permitted or weakly restricted, and the torsional vibration is absorbed by the auxiliary cylinder and the auxiliary piston. The mechanism is ready to function. On the other hand, when the displacement of the generated torsional vibration is large, or when the acting centrifugal force is large, the mass body in the sub cylinder is close to the outer periphery of the rotating body, that is, the pressure received by the ceiling surface of the sub cylinder and the sub piston. Since the space between the main piston and the sub-piston is located on the side where the distance between the main piston and the sub-piston is narrow, the main cylinder and the main piston function to absorb the torsional vibration. Therefore, various torsional vibrations having different amplitudes and frequency ranges can be appropriately absorbed and attenuated with a simple configuration without performing complicated control or the like.

It is a schematic diagram for demonstrating an example of a structure of the torsional damper which concerns on this invention. It is a schematic diagram for demonstrating the other structural example of the torsional damper which concerns on this invention. It is sectional drawing which shows the structure of the torque converter which applies the torsional damper which concerns on this invention, and a damper mechanism. It is a front view which shows the structure of the damper mechanism which applies the torsional damper which concerns on this invention. It is a schematic diagram for demonstrating the state which installed the torsional damper which concerns on this invention in the damper mechanism. It is a figure for demonstrating the relationship between the vibration transmission characteristic of the conventional torsional damper, and a vibration frequency.

  Next, the present invention will be described based on specific examples. The torsional damper according to the present invention is a damper device that is installed between two rotating bodies that are twisted by rotating relative to each other, and absorbs or attenuates torsional vibration generated between them. For example, as shown in FIGS. 3, 4, and 5, the torsional damper of the present invention can be applied to the damper mechanism 300 that is provided in the torque converter 100 together with the lockup clutch 200.

  In FIG. 3, a torque converter 100 has the same configuration as a known general torque converter, and is integrated with a front cover 101 and driven by a power source such as an engine, and the pump impeller 102 includes Mainly composed of turbine runners 103 arranged opposite to each other, and a stator 104 arranged between a fluid outflow part in the turbine runners 103 and a fluid inflow part in the pump impeller 102 to change the flow direction of the fluid. Has been.

  Therefore, in this type of torque converter 100, fluid is present in torque transmission, so that the power transmission efficiency is lower than that of a clutch that mechanically fastens the input / output member, such as a friction clutch or a meshing clutch. To do. For this reason, for example, a lockup clutch 200 is provided that mechanically fastens the input side member and the output side member of the torque converter 100 during high-speed / low-load traveling so that the torque amplification operation by the torque converter 100 is not necessary. Yes.

  The lock-up clutch 200 is disposed between the front cover 101 integrated with the pump impeller 102 of the torque converter 100 and the turbine runner 103, and is pressed against the front cover 101 by, for example, hydraulic pressure to thereby press the front cover 101 and the turbine runner. 103 is directly connected, and torque is transmitted between the front cover 101 and the turbine runner 103.

  Further, when the lockup clutch 200 is engaged, a damper mechanism 300 is provided for absorbing or damping engine torque fluctuations, torsional vibrations and the like resulting from the torque fluctuations. 3 and 4, the damper mechanism 300 includes an annular drive plate 301, a damper spring 302 formed by a compression coil spring, and a driven plate 303 that sandwiches the drive plate 301 and holds the damper spring 302. And the main constituent. Then, when the drive plate 301 and the driven plate 303 rotate relatively, that is, a twist occurs between the plates 301 and 303, the damper spring 302 is compressed by the plates 301 and 303, and the damper springs are compressed. The elastic force 302 absorbs the twist or attenuates the vibration caused by the twist.

  In the conventional damper device using the compression coil spring as described above, the vibration damping performance when absorbing or damping the torsional vibration depends on the characteristics of the compression coil spring to be applied. Therefore, there is a case where the vibration damping performance cannot be effectively exhibited when the frequency range of vibration changes. In addition, as described above, even if it is configured to change the natural frequency of the damper device according to the rotational speed of the rotating body, the vibration damping performance itself by the spring, pendulum, etc. does not change uniformly. The vibration damping performance may not be sufficient for torsional vibrations in a specific frequency range. Therefore, the torsional damper 1 of the present invention is provided together with the damper mechanism 300 using the compression coil spring. That is, as shown in an enlarged view in FIG. 5, the torsional damper 1 of the present invention is an inner peripheral portion of the damper spring 302 in the damper mechanism 300, and is between the drive plate 301 and the driven plate 303 that rotate relative to each other. Is arranged.

  Specifically, as shown in FIG. 1, the torsional damper 1 includes a main cylinder 2 connected to a drive plate 301 that is a rotating body on the input side of the damper mechanism 300, and a cylinder chamber 2 a of the main cylinder 2. A main piston 3 slidably disposed in the main piston 3, a sub cylinder 4 formed inside the main piston 3, a sub piston 5 slidably disposed in a cylinder chamber 4a of the sub cylinder 4, A piston rod 6 that connects the piston 3 and the sub piston 5 to a driven plate 303 that is a rotating body on the output side of the damper mechanism 300 is provided.

  In this configuration example, the main cylinder 2 is connected to the drive plate 301 of the damper mechanism 300 and the piston rod 6 is connected to the driven plate 303 of the damper mechanism 300 as described above. 2 may be connected to the driven plate 303 of the damper mechanism 300, and the piston rod 6 may be connected to the drive plate 301 of the damper mechanism 300.

  The main cylinder 2 is formed in a hollow cylindrical shape, for example. That is, the hollow portion of the inner peripheral portion of the main cylinder 2 is the cylinder chamber 2a, and the sliding portion between the opening 2b of the cylinder chamber 2a and the piston rod 6 is sealed, and the airtightness or liquid of the cylinder chamber 2a is sealed. Denseness is maintained. In the cylinder chamber 2a, the main piston 3 is accommodated and the fluid 7 is filled. For the fluid 7, for example, a fluid having a predetermined viscosity and fluidity such as oil and gas can be applied. In this configuration example, oil 7 is filled in the cylinder chamber 2 a as the fluid 7. One end 2 c of the main cylinder 2, specifically, the end 2 c opposite to the opening 2 b of the main cylinder 2 is connected and fixed to the drive plate 301 of the damper mechanism 300.

  The main piston 3 is formed in a cylindrical shape, for example, corresponding to the shape of the cylinder chamber 2a of the main cylinder 2 described above. Further, the main piston 3 is formed with a through hole 3a that penetrates the inside of the main piston 3 in the axial direction (left-right direction in FIG. 1). That is, the main piston 3 is slidably disposed in the cylinder chamber 2a so as to divide the cylinder chamber 2a into two chambers, and communicates the two chambers of the cylinder chamber 2a divided by the main piston 3. Thus, a through hole 3 a is formed in the main piston 3. In the cylinder chamber 2a, the through hole 3a is also filled with oil 7.

  Therefore, when the main piston 3 relatively moves in the main cylinder 2, the through hole 3a becomes a so-called orifice, and a flow resistance force is generated when the oil 7 flows through the through hole 3a. That is, the torsional damper 1 is configured to absorb or attenuate torsional vibrations using the flow resistance force of the oil 7 generated when the oil 7 flows through the through-hole 3a as described above. Yes.

  The through-hole 3a functions as an orifice as described above, and it is sufficient that at least one through-hole 3a is provided in the main piston 3. However, depending on the desired vibration damping performance or in the main cylinder 2, the main piston 3 may be provided. In consideration of the balance when the two are relatively moved, a plurality of them can be provided in the circumferential direction of the main piston 3. Further, by adjusting the hole diameter and quantity of the through hole 3a, it is possible to adjust the vibration damping performance when the main cylinder 2 and the main piston 3 absorb vibration.

  Further, the inside of the main piston 3 is formed hollow and serves also as the sub cylinder 4. That is, the inside of the main piston 3 is a sub cylinder 4, and the inner peripheral part of the sub cylinder 4 is a cylinder chamber 4a. Similar to the cylinder chamber 2a, the sliding portion between the opening 4b of the cylinder chamber 4a and the piston rod 6 is sealed, so that the air tightness or liquid tightness of the cylinder chamber 4a is maintained. The cylinder chamber 4a accommodates the sub piston 5 and is filled with a fluid 8. A fluid having a predetermined viscosity and fluidity, such as oil and gas, can be applied to the fluid 8 in the same manner as the fluid 7 described above. For example, the oil 7 similar to the fluid 7 may be used, or a gas such as air or an inert gas may be used. In short, the fluid 7 and the fluid 8 are applied by appropriately selecting a fluid having a predetermined viscosity and fluidity, such as oil and gas, according to the desired vibration damping performance.

  The sub-cylinder 4 is formed in the inner peripheral portion of the main piston 3 as described above, and the inner end surface of the cylinder chamber 4a opposite to the opening 4b is a ceiling surface 4c. In other words, the ceiling surface 4c can be rephrased as the bottom surface 4c of the cylinder chamber 4a. In short, as described above, the ceiling surface 4c is an inner end surface of the cylinder chamber 4a opposite to the opening 4b. It is an inner wall surface facing the pressure receiving surface 5a of the sub piston 5 described later in 4a.

  The sub piston 5 is formed in a columnar shape, for example, corresponding to the shape of the cylinder chamber 4a of the sub cylinder 4 described above. The piston rod 6 is integrally fixed to one end surface 5 b of the sub-piston 5, and the end surface 5 b of the piston rod 6 and the end portion 6 a that is not fixed are connected to the driven plate 303 of the damper mechanism 300. Is fixed. Therefore, the secondary piston 5 is connected to the driven plate 303 via the piston rod 6, and the main piston 3 is connected to the driven plate 303 via the secondary piston 5 and the piston rod 6.

  Further, the other piston end face of the sub-piston 5, that is, the end face opposite to the side of the sub-piston 5 where the piston rod 6 is fixed, receives the pressure received by the sub-piston 5 facing the ceiling surface 4c in the cylinder chamber 4a. A tapered surface 5a that is inclined at a predetermined angle with respect to the ceiling surface 4c is formed on the surface 5a. Specifically, in a state where the sub piston 5 is housed in the sub cylinder 4, the distance between the pressure receiving surface 5a and the ceiling surface 4c facing each other in the cylinder chamber 4a is the rotation center side of the damper mechanism 300 (in FIG. The pressure-receiving surface 5a of the secondary piston 5 is formed as a tapered surface 5a that is gradually narrowed from the lower side to the outer peripheral side (upper side in FIG. 1).

  In the space between the ceiling surface 4c and the tapered surface 5a in the cylinder chamber 4a, a ball 9 which is a mass body having a specific gravity larger than the fluid 8 in the cylinder chamber 4a and having a predetermined weight and rigidity is enclosed. Has been. In the configuration example shown in FIG. 1, the ball 9 is movable in a space between the ceiling surface 4c and the tapered surface 5a in the cylinder chamber 4a. Therefore, the ball 9 is rotated on the side of the rotation center of the damper mechanism 300 in the space between the ceiling surface 4c and the tapered surface 5a in the cylinder chamber 4a when the damper mechanism 300 rotates and centrifugal force acts. It moves to the outer peripheral side. In other words, the ball 9 moves to the outer peripheral side as the centrifugal force acting by the rotation of the damper mechanism 300 increases. As a result, the ball 9 comes into contact with the ceiling surface 4c and the tapered surface 5a, and the main piston 3 and the sub piston The relative movement to 5 is restricted.

  Thus, in the torsional damper 1, according to the magnitude of the relative rotational displacement, that is, the twist between the drive plate 301 and the driven plate 303 of the damper mechanism 300, and according to the magnitude of the acting centrifugal force, The relative movement between the main piston 3 and the sub piston 5 is restricted. That is, when a twist larger than a predetermined displacement set in advance by design or experiment occurs, the secondary piston 5 moves toward the ceiling surface 4c of the secondary cylinder 4 via the piston rod 6, and as a result, The relative movement between the main piston 3 and the sub piston 5 is restricted by the taper surface 5a of the sub piston 5 and the ceiling surface 4c coming into contact with each other. Further, when a centrifugal force larger than a predetermined force set in advance by design or experiment is applied to the torsional damper 1, the ball 9 moves from the rotation center side to the outer periphery side in the cylinder chamber 4a of the sub cylinder 4. As a result, the ball 9 abuts on both the ceiling surface 4c and the tapered surface 5a, in other words, the ball 9 is sandwiched between the ceiling surface 4c and the tapered surface 5a, whereby the main piston 3 and the sub piston 5 The relative movement between is restricted. Therefore, the ceiling surface 4c of the sub cylinder 4, the tapered surface 5a of the sub piston 5 and the ball 9 constitute the damping force adjusting mechanism 10 in the present invention.

  Although not shown, a positioning mechanism such as a key and a key groove or a cotter and a cotter groove is provided between the main cylinder 2 and the main piston 3 and between the sub cylinder 4 and the sub piston 5. Is provided. That is, a positioning mechanism is provided between the main cylinder 2 and the main piston 3 and between the sub-cylinder 4 and the sub-piston 5, and relative rotation in the circumferential direction is restricted. Therefore, the taper surface 5a of the sub-piston 5 is always narrower as the distance between the pressure receiving surface 5a and the ceiling surface 4c facing each other in the cylinder chamber 4a goes from the rotation center side to the outer periphery side of the damper mechanism 300 as described above. It is held in an inclined posture.

  FIG. 2 shows another configuration example of the present invention. In the example shown in FIG. 1 described above, the ball 9 corresponding to the mass body of the present invention is movably enclosed in the cylinder chamber 4a of the sub cylinder 4 without being fixed to any member. However, in the torsional damper 1 shown in FIG. 2, the ball 9 enclosed in the cylinder chamber 4a of the sub cylinder 4 is fixed or held in the cylinder chamber 4a by a stretchable elastic member 11. .

  That is, in FIG. 2, one end of the elastic member 11 is fixed to the sub cylinder 4 in the space between the ceiling surface 4c in the cylinder chamber 4a of the sub cylinder 4 and the tapered surface 5a of the sub piston 5, The other end of the member 11 is connected to the ball 9.

  The elastic member 11 can be made of an elastic material such as a compression coil spring or rubber, for example. One end of the cylinder chamber 4a is fixed to the sub-cylinder 4 so that it can expand and contract in the radial direction (vertical direction in FIG. 2) of the damper mechanism 300 at a position close to the ceiling surface 4c of the cylinder chamber 4a. The ball 9 is connected and fixed to the other end not fixed to the sub cylinder 4. In addition, the structure by which the ball | bowl 9 is rotatably hold | maintained at the other edge part of the elastic member 11 may be sufficient.

  As described above, the ball 9 in the configuration example shown in FIG. 2 is fixed to the sub-cylinder 4 in the cylinder chamber 4a via the elastic member 11, and the elastic member 11 causes the rotation center side (in FIG. It is always urged from the lower side to the outer peripheral side (upper side in FIG. 2). Therefore, when the secondary piston 5 moves more than a predetermined stroke toward the ceiling surface 4c in the axial direction (left and right direction in FIG. 2) with respect to the secondary cylinder 4, the ball 9 has a cylinder as shown in FIG. The chamber 4a is always held in contact with both the ceiling surface 4c and the taper surface 5a to restrict relative movement between the main piston 3 and the sub piston 5. The sub piston 5 moves back and forth in the axial direction relative to the sub cylinder 4 to move up and down in the radial direction in the cylinder chamber 4a.

  Further, when the damper mechanism 300 is rotating and centrifugal force acts on the ball 9, both the urging force and centrifugal force by the elastic member 11 act on the ball 9, and as a result, the main piston 3. And the relative movement between the secondary piston 5 are strongly restricted.

  Therefore, in the torsional damper 1 having the configuration shown in FIG. 2, the main piston 3 and the sub piston are adjusted by adjusting the elastic force of the elastic member 11 that urges the ball 9, for example, by adjusting the spring constant of the coil spring. The state which controls the relative movement between 5 can be adjusted as appropriate. For example, by making the spring constant of the coil spring used as the elastic member 11 relatively low, the relative movement between the main piston 3 and the sub-piston 5 can be weakly restricted, and on the contrary, it is used as the elastic member 11. By relatively strengthening the spring constant of the coil spring, the relative movement between the main piston 3 and the sub-piston 5 can be more strongly regulated.

  As described above, according to the torsional damper 1 of the present invention, when the displacement of the generated torsional vibration is small and the acting centrifugal force is small, the ball 9 in the cylinder chamber 4a of the sub cylinder 4 is Since it is located on the side close to the rotation center of 300, that is, on the side where the space between the ceiling surface 4c of the sub cylinder 4 and the taper surface 5a of the sub piston 5 is wide, relative movement between the main piston 3 and the sub piston 5 is allowed. Is done. Or the relative movement is weakly regulated. As a result, the mechanism that absorbs torsional vibrations functions by the sub cylinder 4 and the sub piston 5.

  On the other hand, when the displacement of the generated torsional vibration is large, or when the acting centrifugal force is large, the ball 9 in the cylinder chamber 4a of the sub cylinder 4 is closer to the outer periphery of the damper mechanism 300, that is, the sub cylinder 4 Since the space between the ceiling surface 4c and the tapered surface 5a of the sub piston 5 is located on the narrow side, the relative movement between the main piston 3 and the sub piston 5 is strongly restricted. As a result, the main cylinder 2 and the main piston 3 function to absorb the torsional vibration.

  For example, when the torsional vibration increases beyond a predetermined displacement, or when the centrifugal force acting on the torsional damper 1 increases beyond a predetermined force, the relative movement between the main piston 3 and the sub piston 5 is increased. By being restricted, the main cylinder 2 and the main piston 3 are in a state in which a mechanism for absorbing torsional vibrations functions. Further, when the centrifugal force acting on the torsional damper 1 increases beyond a predetermined force, the relative movement between the main piston 3 and the sub-piston 5 is more firmly restricted as the centrifugal force increases.

  Accordingly, for example, when a torsional vibration having a large displacement or amplitude occurs, or when a large centrifugal force acts on the torsional damper 1, that is, when the torsional damper 1 rotates at a high rotational speed, the sub cylinder 4 is relatively moved. In addition, the main cylinder 2 and the main piston 3 can absorb the torsional vibration, which has higher vibration damping performance than the case where the subpiston 5 absorbs the torsional vibration.

  Thus, the mechanism for absorbing torsional vibrations by the main cylinder 2 and the main piston 3 and the mechanism for absorbing torsional vibrations by the sub-cylinder 4 and the sub-piston 5 are divided into the magnitude of the torsional vibration and the magnitude of the acting centrifugal force. The function can be switched according to the function. Therefore, various torsional vibrations having different amplitudes and frequency ranges can be appropriately absorbed and attenuated with a simple configuration without performing complicated control or the like.

  DESCRIPTION OF SYMBOLS 1 ... Torsional damper, 2 ... Main cylinder, 3 ... Main piston, 3a ... Through-hole, 4 ... Sub cylinder, 4c ... Ceiling surface, 5 ... Sub piston, 5a ... Tapered surface, pressure receiving surface, 7 ... Oil (fluid) ), 9... Ball (mass body), 10. Damping force adjusting mechanism, 300... Damper mechanism, 301... Drive plate (input side rotating body), 303.

Claims (4)

A main cylinder connected to either the input-side rotator or the output-side rotator that is twisted by relative rotation, and a slidably provided inside the main cylinder so that the interior is divided into two chambers And a main piston connected to one of the rotating bodies, a through hole formed through the main piston so as to communicate with the two chambers, and a fluid filled in the main cylinder In a torsional damper that acts as a resistance force against the relative rotation, the flow resistance force when the fluid flows through the through hole,
A sub-cylinder formed inside the main piston;
A sub-piston that is slidably provided in the sub-cylinder and connected to the other rotating body;
A torsional damper comprising: a damping force adjusting mechanism that restricts relative movement between the main piston and the sub-piston according to the magnitude of the twist and the magnitude of the acting centrifugal force.   The damping force adjusting mechanism includes means for restricting the relative movement when the twist greater than a predetermined displacement set in advance or when the centrifugal force greater than a predetermined force is applied. The torsional damper according to claim 1.   The torsional damper according to claim 2, wherein the damping force adjusting mechanism includes means for strongly restricting the relative movement as the centrifugal force increases. The damping force adjusting mechanism is
The pressure-receiving surface of the sub-piston facing the ceiling surface of the sub-cylinder is formed such that the distance from the ceiling surface becomes narrower from the rotation center side to the outer peripheral side of the rotating body, and from a predetermined displacement set in advance A taper surface that restricts the relative movement by contacting the ceiling surface when a large twist occurs,
Enclosed between the ceiling surface and the tapered surface in the sub-cylinder, the larger the centrifugal force is, the more the outer peripheral side moves and the relative movement is brought into contact with both the ceiling surface and the tapered surface. The torsional damper according to claim 1, further comprising a mass body to be regulated.

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