JP2004088934A - Hysteresis brake - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To get the large braking torque by an eddy current without incurring the enlargement of the cylinder of hysteresis material. <P>SOLUTION: This hysteresis brake is provided with inner pole teeth 23 and outer pole teeth 24 at the peripheral opposed faces in a pair of a magnetic induction member 22, and the magnetic induction member 22 is attached to a no-rotation member 24. Each pole tooth element of the inner magnetic pole tooth 23 and the outer pole tooth 24 is offset in circumferential direction, and a hysteresis ring 26 coupled with a rotor 18 is interposed between both pole teeth 23 and 24. Braking force is generated by the discrepancy between the direction of an external magnetic field generated between both pole teeth by the excitation of an electromagnetic coil and the direction of the internal magnetic flux of the hysteresis ring 26. Furthermore, conductive materials 40 are fixed as plated films to both inner and outer faces of the hysteresis ring 26, and the conductive materials 40 serve as eddy current generation parts. Here, the generated eddy current becomes braking force geared to the rotational speed. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The invention of this application relates to a hysteresis brake that obtains a braking force by utilizing a magnetic hysteresis characteristic of a hysteresis material.
[0002]
[Prior art]
As this type of brake, for example, there is one described in Japanese Patent Application Laid-Open No. 56-132160.
[0003]
In this brake, a pair of pole teeth forming different magnetic poles by energization of an electromagnetic coil is supported by a fixed block so that mutual pole tooth elements alternate in the circumferential direction, and a hysteresis connected to a rotating shaft is provided. A cylindrical wall of the material is arranged outside the pole teeth group with a predetermined gap. This configuration is a normal hysteresis brake configuration in which a braking force is generated by a deviation between the direction of the magnetic field generated between adjacent pole teeth generated by energization of the electromagnetic coil and the internal magnetic flux of the hysteresis material. Further, a conductive material is fixed to the inner peripheral surface of the cylindrical portion of the hysteresis material facing the pole tooth element. Therefore, in this brake, when the electromagnetic coil is excited, an eddy current is generated in the conductive material portion, and a braking force is also generated as the eddy current brake.
[0004]
In the case of the eddy current brake, the braking torque is almost proportional to the rotation speed of the rotating shaft. Therefore, when the rotating shaft is not rotating or rotating at a low speed, sufficient braking torque cannot be obtained. In the case of the brake, since both functions of the normal eddy current brake and the hysteresis brake are provided, a large braking torque can be obtained by the function of the hysteresis brake even at the time of stop or low-speed rotation.
[0005]
[Problems to be solved by the invention]
However, in the case of the conventional brake, since the conductive material is fixed and becomes the eddy current generating portion only on the inner peripheral side of the cylindrical portion of the hysteresis material, the eddy current generating portion is limited to a narrow range. Unless the diameter of the part is enlarged, it is difficult to obtain a large braking torque due to the eddy current.
[0006]
Therefore, the invention of this application is to provide a hysteresis brake that can obtain a large braking torque by eddy current without increasing the size of the cylindrical portion of the hysteresis material.
[0007]
[Means for Solving the Problems]
As a means for solving the above-mentioned problem, the invention of this application is to provide an inner pole tooth and an outer pole tooth on a peripheral facing surface of a magnetic induction member attached to a non-rotating member, respectively, Each of the pole teeth elements of the teeth and the outer pole teeth are circumferentially offset, and a cylindrical wall of a hysteresis material attached to a rotating member is interposed between the inner and outer pole teeth in a non-contact state, A braking force is generated by a difference between the direction of the external magnetic field generated between the pole teeth by the excitation of the electromagnetic coil and the direction of the magnetic flux inside the hysteresis material, and furthermore, a conductive material is applied to both the inner and outer surfaces of the cylindrical wall of the hysteresis material. The conductive material portions on the inner and outer surfaces were used as eddy current generating portions.
[0008]
In the case of the present invention, when the electromagnetic coil is excited, the braking force of the original hysteresis brake is generated between the pole teeth and the cylindrical wall of the hysteresis material, and the vortex is generated between the conductive material on the inner and outer surfaces of the cylindrical wall and the pole teeth. Generates braking force due to electric current. Therefore, in contrast to the conventional structure in which only the inner peripheral side of the cylindrical wall serves as the eddy current generating section, the outer peripheral side of the cylindrical wall also serves as the eddy current generating section, so that a larger braking torque due to the eddy current can be obtained. It becomes possible. Further, both the inner and outer surfaces of the cylindrical wall of the hysteresis material serve as eddy current generating portions, and a large braking torque can be obtained without increasing the diameter of the cylindrical wall of the hysteresis material.
[0009]
The conductive material is desirably fixed as a plating film on both the inner and outer surfaces of the cylindrical wall. In this case, the conductive material can be easily and thinly fixed to both the inner and outer surfaces of the cylindrical wall. When the conductive material is thinly fixed in the form of a film in this manner, it is possible to bring the respective pole teeth and the hysteresis material sufficiently close to each other, and to reduce the braking torque inherent in the hysteresis brake without causing a large braking by the eddy current. Can be obtained. In addition, the entire device can be downsized as the thickness of the conductive material is reduced.
[0010]
Further, the hysteresis brake includes a driving rotating body that is rotationally driven by a crankshaft of the internal combustion engine, a driven rotating body composed of a camshaft or a separate member coupled to the same shaft, and the driving rotating body and the driven rotating body. An intermediate rotating body that is relatively rotatable with respect to the rotating body, and an assembling angle operating mechanism that relatively rotates the driving rotating body and the driven rotating body by rotating the intermediate rotating body; and In a valve timing control device for an internal combustion engine having a braking mechanism for applying a braking force to perform a turning operation, the braking mechanism may be used.
[0011]
The braking mechanism of this type of valve timing control device is greatly affected by the alternating torque of the camshaft (fluctuation torque caused by the biasing force of the valve spring and the profile of the driving cam) in a range where the engine rotation speed is low. As the engine rotation speed increases, a large braking torque is required to resist the rotation torque of the camshaft. In the case of this hysteresis brake, while the engine speed is low, a sufficient braking torque can be secured by the original braking function of the hysteresis brake, and when the engine speed is increased, an eddy current corresponding to the speed is generated. Since a large braking torque can be obtained, the two requirements of low rotation and high rotation can be simultaneously satisfied.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, an embodiment of the invention of this application will be described based on the drawings.
[0013]
In this embodiment, a hysteresis brake according to the invention of this application is applied to a valve timing control device for an internal combustion engine. In the following, the valve timing control device is described as being applied to an intake-side valve train of an internal combustion engine, but may be similarly applied to an exhaust-side valve train.
[0014]
As shown in FIG. 1, the valve timing control device is rotatable relative to a camshaft 1 rotatably supported by a cylinder head (not shown) of an internal combustion engine, and can rotate relative to the front end of the camshaft 1 as necessary. Ring (drive rotary member) having a timing sprocket 2 on its outer periphery, which is linked to a crankshaft (not shown) via a chain (not shown), and the drive ring 3 and the camshaft 1 1 is arranged on the front side (the left side in FIG. 1) of the assembling angle operating mechanism 4 for operating the assembling angle of the both 3 and 1; FIG. 2 is a diagram showing an operating force applying means 5 for driving the mechanism 4, and a cylinder head (not shown) of the internal combustion engine, which is attached across a front surface of a head cover and covers the front surface and the peripheral area of the assembly angle operating mechanism 4 and the operating force applying means 5. VT outside And it includes a cover, a.
[0015]
The drive ring 3 is formed in a substantially disk shape having a stepped insertion hole 6, and the insertion hole 6 is rotated by a driven shaft member 7 (driven rotation body) coupled to the front end of the camshaft 1. Assembled as possible. As shown in FIG. 2, three radial grooves 8 (radial guides) having parallel side walls facing each other are formed on the front surface of the drive ring 3 (the surface opposite to the camshaft 1). It is formed substantially along the radial direction.
[0016]
As shown in FIG. 1, the driven shaft member 7 has an enlarged-diameter portion formed on an outer periphery of a base portion that abuts on a front end portion of the camshaft 1, and has an outer peripheral surface on a front side of the enlarged diameter portion. Three levers 9 projecting radially are integrally formed and connected to the camshaft 1 by bolts 10 penetrating the shaft core. A base end of a link 11 is pivotally connected to each lever 9 by a pin 12, and a column-shaped projection 13 slidably engaged with each of the radial grooves 8 is integrally formed at a distal end of each link 11. Is formed.
[0017]
Each link 11 is connected to the driven shaft member 7 via the pin 12 in a state where the protrusion 13 is engaged with the corresponding radial groove 8. When displaced along 8, the drive ring 3 and the driven shaft member 7 rotate relative to each other by the action of the link 11 in a direction and an angle corresponding to the displacement of the projection 13.
[0018]
A receiving hole 14 is formed at the distal end of each link 11 and opens forward in the axial direction. The receiving hole 14 has an engaging pin 16 that engages with a spiral groove 15 (a spiral guide) described later. And a coil spring 17 for urging the engagement pin 16 forward (toward the spiral groove 15). In the case of this embodiment, a movable guide portion that can be displaced in the radial direction is configured by the protrusion 13 at the tip of the link 11, the engagement pin 16, the coil spring 17, and the like.
[0019]
On the other hand, an intermediate rotating body 18 having a disk-shaped flange wall is rotatably supported via a bearing 19 in front of the driven shaft member 7 at a position forward of the lever 9. The above-mentioned spiral groove 15 having a semicircular cross section is formed on the rear surface side of the flange wall of the intermediate rotating body 18, and the engaging pin 16 at the tip of each link 11 is guided in the spiral groove 15 so as to freely roll. Is engaged. The spiral of the spiral groove 15 is formed so that its diameter gradually decreases along the engine rotation direction R. Therefore, when the intermediate rotating body 18 relatively rotates in the delay direction with respect to the drive ring 3 in a state where the engaging pin 16 at the tip of each link 11 is engaged with the spiral groove 15, the tip of the link 11 is While being guided by the spiral shape of the spiral groove 15 and moving inward in the radial direction, conversely, when the intermediate rotating body 18 is relatively displaced in the advancing direction, it moves outward in the radial direction.
[0020]
Reference numerals 48 and 49 in the figure denote projections and stoppers that come into contact with each other when the drive ring 3 and the intermediate rotating body 18 rotate relative to each other by more than a set angle, thereby restricting the rotation of the two.
[0021]
The assembling angle operating mechanism 4 includes the radial groove 8, the link 11, the protrusion 13, the engaging pin 16, the lever 9, the intermediate rotating body 18, the spiral groove 15, and the like of the drive ring 3 described above. When the relative rotation operation force with respect to the camshaft 1 is input from the operation force applying means 5 to the intermediate rotating body 18, the operation angle operation mechanism 4 applies the operation force to the spiral groove 15 and the engagement pin 16. The distal end of the link 11 is displaced in the radial direction through the engaging portion, and at this time, relative rotational power is transmitted to the drive ring 3 and the driven shaft member 7 by the action of the link 11 and the lever 9.
[0022]
On the other hand, the operating force applying means 5 includes a mainspring spring 47 for urging the intermediate rotating body 18 in the engine rotation direction R with respect to the drive ring 3, and an operating force applying means 5 for rotating the intermediate rotating body 18 with respect to the drive ring 3 in the engine rotation direction R And a hysteresis brake 20 (hysteresis brake according to the invention of this application) as a braking mechanism for urging in the direction, and by appropriately controlling the braking force of the hysteresis brake 20 according to the operating state of the internal combustion engine. The intermediate rotator 18 is rotated relative to the drive ring 3, or the rotational positions of both are maintained.
[0023]
The mainspring spring 47 has an outer peripheral end coupled to the cylindrical wall 21 extending from the drive ring 3, and an inner peripheral end coupled to the cylindrical base of the intermediate rotating body 18, and is entirely formed of the intermediate rotating body. 18 are arranged in the front space of the flange wall. A sealing wall 50 is integrally connected to the end face of the intermediate rotating body 18 opposite to the camshaft 1, and the outer peripheral surface of the sealing wall 50 is slidably in close contact with the inner surface of the cylindrical wall 21. ing. A pair of connecting pins 53 whose tips project in the direction opposite to the camshaft 1 penetrate the sealing wall 50 and are attached to the intermediate rotating body 18. This connecting pin 53 will be described later.
[0024]
On the other hand, the hysteresis brake 20 is attached to a VTC cover that is a non-rotating member, and has a pair of circumferentially facing magnetic induction members 22 that face each other across a substantially cylindrical gap. The inner pole teeth 23 and the outer pole teeth 24 provided; an electromagnetic coil 25 attached to the magnetic induction member 22 to generate a magnetic field between the inner pole teeth 23 and the outer pole teeth 24; And a cylindrical hysteresis ring 26 inserted between the bipolar teeth 23 and 24 in a state where the electromagnetic coil 25 is connected to the pole teeth 23 and 24. The electromagnetic coil 25 is energized by a controller (not shown).
[0025]
In the case of this embodiment, the hysteresis brake 20 is unitized as shown in FIGS.
[0026]
The magnetic guide member 22 includes an inner tooth ring 27 having inner pole teeth 23 on the outer peripheral surface, an outer tooth ring 28 having outer polar teeth 24 on the inner peripheral surface, and a connection connecting the inner tooth ring 27 and the outer tooth ring 28. And a ring 29. An annular step is provided in the outer peripheral corner of the connecting ring 29 on the side facing the pole teeth 23, 24, and the electromagnetic coil 25 is fitted and mounted on the step.
[0027]
Further, the inner pole teeth 23 and the outer pole teeth 24 each have a plurality of pole tooth elements extending along the axial direction. The pole teeth elements of both pole teeth 23 and 24 are respectively arranged along the circumferential direction, and the pole tooth elements of each pole tooth 23 and 24 are mutually offset in the circumferential direction. Therefore, when the electromagnetic coil 25 is energized, a magnetic field is generated between the two pole teeth 23 and 24 toward the partner pole tooth element having an offset positional relationship.
[0028]
The hysteresis ring 26 is made of a hysteresis material having magnetic hysteresis characteristics, and a metal annular plate 33 (plate member) is fitted and fixed to an end protruding from a gap between the bipolar teeth 23 and 24. I have. The annular plate 33 is integrally connected to a shaft member 36 supported on the inner peripheral surface of the connection ring 29 via bearings 34 and 35. Therefore, the hysteresis ring 26 is rotatably supported by the magnetic guide member 22 via the annular plate 33 and the shaft member 36. A pair of circular recesses 37 are provided on the back surface (the surface on the camshaft 1 side) of the annular plate 33, and the connection pins 53 of the intermediate rotating body 18 are provided in the respective recesses 37 via rubber bushes 38. Mated. Therefore, the annular plate 33 and the hysteresis ring 20 rotate integrally with the intermediate rotating body 18 via the rubber bush 38 and the connecting pin 53.
[0029]
Incidentally, the hysteresis ring 26 is formed in a cylindrical shape as a whole, and a conductive material 40 such as copper is coated on both inner and outer surfaces thereof as a plating film. The film-shaped conductive material 40 is a portion that becomes an eddy current generating portion. When the conductive material 40 traverses magnetic flux from the pole teeth 23 (or 24), an eddy current is generated. Exerts a braking action that hinders the rotation of the hysteresis ring 26 (the intermediate rotating body 18). Therefore, in the case of the hysteresis delay 20, when the electromagnetic coil 25 is excited, the braking action by the eddy current generated in the conductive material 40 simultaneously acts in addition to the braking action by the hysteresis material. However, when the hysteresis ring 26 is stopped, the braking force due to the eddy current does not act.
[0030]
Here, FIG. 5 shows the rotational speed characteristics of the braking torque by the hysteresis material (hereinafter, referred to as “hysteresis torque”) and the braking torque by the eddy current (hereinafter, referred to as “eddy current torque”) in the hysteresis brake 20. This will be described with reference to the characteristic diagram of FIG. FIG. 5 is a characteristic diagram in which the number of rotations of the hysteresis ring is plotted on the horizontal axis and the braking torque is plotted on the vertical axis, where b indicates the hysteresis torque, c indicates the eddy current torque, and a indicates the hysteresis torque. 4 shows a combined torque of b and the eddy current torque c.
[0031]
As is clear from this figure, the hysteresis torque b always has a substantially constant value irrespective of the change in the rotation speed, and the eddy current torque c has a value of 0 when the rotation speed is 0. The value increases in proportion. Then, the resultant torque c becomes the total braking torque of the hysteresis brake 20, and a constant torque by the hysteresis torque is secured even when the rotational speed is 0. In addition, when the rotational speed increases, the eddy current torque is reduced according to the increase. The torque is added.
[0032]
Since the valve timing control device is configured as described above, the excitation of the electromagnetic coil 25 of the hysteresis brake 20 is turned off at the time of starting the internal combustion engine or at the time of idling, whereby the intermediate rotation is performed by the force of the mainspring spring 47. The body 18 is rotated to the maximum in the engine rotation direction R with respect to the drive ring 3 (see FIG. 2). As a result, the rotational phase of the crankshaft and the camshaft 1 (opening / closing timing of the engine valve) is maintained at the most retarded side, so that engine rotation is stabilized and fuel efficiency is improved.
[0033]
Then, from this state, the operation of the engine shifts to the normal operation, and when a command to change the rotation phase to the most advanced side is issued from a controller (not shown), the excitation of the electromagnetic coil 25 of the hysteresis brake 20 is turned on. Then, a braking torque against the mainspring spring 47 is applied to the intermediate rotating body 18. As a result, the intermediate rotating body 18 rotates in the opposite direction with respect to the drive ring 3, whereby the engaging pin 16 at the tip of the link 11 is guided to the spiral groove 15, and the tip of the link 11 is inserted into the radial groove 8. 3, the assembling angle between the drive ring 3 and the driven shaft member 7 is changed to the most advanced angle side by the action of the link 11, as shown in FIG. As a result, the rotation phases of the crankshaft and the camshaft 1 are changed to the most advanced angle side, thereby increasing the output of the engine.
[0034]
When a command is issued from the controller to change the rotation phase to the most retarded side from this state, the excitation of the electromagnetic coil 25 of the hysteresis brake 20 is turned off, and the intermediate rotating body 18 is again actuated by the force of the mainspring 47. Is rotated in the engine rotation direction R. Then, the guide pin 16 guided by the spiral groove 15 causes the link 11 to swing in the opposite direction to the above, and as shown in FIG. 2, the action of the link 11 causes the angle of attachment of the driven shaft member 7 of the drive ring 3 to be reduced. It is changed to the retard side again.
[0035]
The rotation phase of the crankshaft and the camshaft 1 by this valve timing control device is not limited to the two phases of the most retarded angle and the most advanced angle described above, but may be any value determined by controlling the braking force of the hysteresis brake 20. The phase can be changed and the phase can be maintained by the balance between the force of the mainspring 47 and the braking force of the hysteresis brake 20.
[0036]
The control of the valve timing is not limited to the pattern described above, and the control can be variously changed according to the specifications of the internal combustion engine. At this time, for example, when the internal combustion engine is running at a low speed, it is conceivable to change the rotation phase to the advanced side by controlling the hysteresis brake 20, but this hysteresis brake 20 rotates the hysteresis ring 26 as described above. Even when the speed is low or completely zero, a large braking torque due to the hysteresis torque can be obtained. Therefore, it is assumed that the alternating torque of the camshaft 1 during the low engine speed is input to the intermediate rotor 18. However, there is no problem that the intermediate rotating body 18 is pushed against the braking torque by the alternating torque.
[0037]
When the rotation speed of the internal combustion engine increases, the driving torque of the camshaft 1 also increases according to the rotation speed. However, the hysteresis brake 20 increases the eddy current torque component according to the rotation speed. The valve timing can be changed with good responsiveness even when the rotation speed of the engine becomes high, and the changed state can be reliably maintained.
[0038]
In the hysteresis brake 20 used in this device, a magnetic material 40 such as copper is fixed on the inner and outer surfaces of a cylindrical hysteresis ring 26, and eddy currents due to the magnetic fields of the pole teeth 23 and 24 are generated on the inner and outer surfaces of the hysteresis ring 26. As a result, it is possible to obtain a large braking torque due to the eddy current without increasing the diameter of the hysteresis ring 26 as compared with the conventional one in which only the inner peripheral surface side of the hysteresis material serves as an eddy current generating portion. it can. Therefore, by using the hysteresis brake 20, the valve timing control device can improve the response of the valve timing control and increase the phase holding force without increasing the size of the entire device.
[0039]
Further, in the hysteresis brake 20 of this embodiment, since the conductive material 40 is applied as a plating film to both the inner and outer surfaces of the hysteresis ring 26, the conductive material 40 can be easily fixed thinly, and the thickness of the conductive material 40 itself can be reduced. Is extremely thin, the distance from each of the pole teeth 23, 24 to the surface of the hysteresis ring 26 is reduced, and a larger hysteresis torque can be obtained. Further, the outer diameter of the hysteresis brake 20 is reduced by the reduction in the thickness of the conductive material 40.
[0040]
The conductive material 40 fixed to the hysteresis ring 26 by plating or the like is not limited to copper, but may be other materials such as aluminum, gold, and silver. However, copper has a very high conductivity and a material cost. Therefore, it is the most suitable material for achieving both cost and performance.
[0041]
In the above description, the hysteresis brake according to the invention of the present application is applied to the braking mechanism of the valve timing control device. However, the brake can be applied not only to the valve timing control device but also to various other devices.
[0042]
Next, inventions other than those described in the claims that can be grasped from the above-described embodiments will be described below together with their operational effects.
[0043]
3. The hysteresis brake according to claim 2, wherein the conductive material is made of copper.
[0044]
In this case, since copper has good conductivity and easily generates an induced electromotive force, it is possible to generate a large braking torque due to eddy current, and further, since the material cost of copper is easy, the manufacturing cost of the device is reduced. be able to.
[0045]
(B) The assembling angle operating mechanism is provided in a radial direction guide provided on one of the driving rotating body and the driven rotating body, and is provided so as to be rotatable relative to the driving rotating body and the driven rotating body. An intermediate rotating body having a spiral guide on the surface facing the direction guide, a movable guide portion displaceably engaged with the radial guide and the spiral guide, and a driving rotating body and a driven rotating body. The hysteresis brake according to claim 3 or (a), further comprising a link that swingably connects a portion of the other of the other members separated from the rotation center and the movable guide portion. .
[0046]
In this case, the operation friction of the assembling angle operation mechanism becomes extremely small, and the assembling angle between the driving rotating body and the driven rotating body is hardly changed by the fluctuation torque on the camshaft side. Is also smaller. Therefore, the size of the hysteresis brake that can obtain a large braking torque without increasing the size of the device can be further reduced.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing an embodiment of the present application.
FIG. 2 is an exemplary sectional view of the same embodiment taken along line AA of FIG. 1;
FIG. 3 is an exemplary sectional view corresponding to FIG. 2 showing an operation state of the embodiment;
FIG. 4 is an exploded perspective view showing the same embodiment.
FIG. 5 is a torque characteristic diagram of the hysteresis brake of the embodiment.
[Explanation of symbols]
3. Drive ring (drive rotator)
4: Assembling angle operating mechanism 7: Driven shaft member (driven rotator)
18 intermediate rotating body 20 hysteresis brake (braking mechanism)
22 magnetic induction member 23 inner pole teeth 24 outer pole teeth 25 electromagnetic coil 26 hysteresis ring (hysteresis material)
40 ... conductive material

Claims (3)

A magnetic induction member attached to the non-rotating member and having a pair of circumferentially opposed surfaces facing each other with a substantially cylindrical gap therebetween,
On the radially inner surface of the pair of opposing surfaces, a plurality of pole tooth elements are provided with inner pole teeth provided along the circumferential direction,
On a radially outer surface of the pair of opposing surfaces, a plurality of pole tooth elements are provided along a circumferential direction, and each pole tooth element is arranged in a circumferential direction with respect to a pole tooth element of the inner pole tooth. Outer pole teeth arranged offset to the
A hysteresis material attached to the rotating member and having a cylindrical wall interposed in a non-contact state between the inner pole teeth and the outer pole teeth of the magnetic induction member;
An electromagnetic coil that generates a magnetic field between the inner pole teeth and the outer pole teeth,
A hysteresis brake that generates a braking force by a difference between a direction of an external magnetic field generated between the inner pole teeth and the outer pole teeth and a direction of a magnetic flux inside the hysteresis material,
A hysteresis brake, wherein a conductive material is fixed to both inner and outer surfaces of the cylindrical wall of the hysteresis material. 2. The hysteresis brake according to claim 1, wherein said conductive material is fixed on both inner and outer surfaces of a cylindrical wall as plating films. A driving rotating body that is rotationally driven by a crankshaft of an internal combustion engine, a driven rotating body composed of a camshaft or a separate member coupled to the shaft, and a rotatable relative to the driving rotating body and the driven rotating body. An assembling angle operating mechanism having an intermediate rotator for rotating the driving rotator and the driven rotator relative to each other by rotating the intermediate rotator; and a braking force for rotating the intermediate rotator. The hysteresis brake according to claim 1 or 2, wherein the brake mechanism is used in the braking mechanism of a valve timing control device for an internal combustion engine, the braking mechanism including:

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