JP4605292B2 - Valve timing adjustment device - Google Patents

Description

  The present invention relates to a valve timing adjusting device that adjusts the valve timing of a valve that opens and closes a camshaft by torque transmission from a crankshaft in an internal combustion engine.

  2. Description of the Related Art Conventionally, there is known a valve timing adjusting device that adjusts a relative phase between a crankshaft and a camshaft that determines valve timing (hereinafter referred to as “engine phase”) according to a brake torque generated by an actuator. As such a valve timing adjusting device, Patent Literature 1 discloses a device that adjusts an engine phase by generating a brake torque by a fluid actuator.

  Specifically, the apparatus of Patent Document 1 uses an actuator that variably controls the viscosity of the magnetorheological fluid by applying a magnetic field to the magnetorheological fluid that is enclosed in a fluid chamber inside the housing and contacts the brake rotating body. It has been. According to this actuator, the brake torque corresponding to the viscosity of the magnetorheological fluid is input to the brake rotating body that supports the casing, and the engine phase is adjusted according to the brake torque by the phase adjusting mechanism that is linked to the brake rotating body. is there.

  In particular, in the actuator of the device of Patent Document 1, the fluid chamber inside the housing partially filled with the magnetorheological fluid is communicated with the outside of the housing so that at least gas can be circulated. According to this, in the fluid chamber, the partially filled magnetorheological fluid and the remaining air expand and contract (hereinafter also referred to as expansion and contraction) due to a temperature change, and the internal pressure of the fluid chamber increases and decreases accordingly. Since air enters and exits outside the casing, the increase / decrease width of the internal pressure can be reduced to avoid a decrease in durability due to deformation of the casing and the brake rotating body. Here, as a temperature change that causes an increase or decrease in the internal pressure of the fluid chamber, not only a change in the environmental temperature but also a temperature change caused by heat generated by braking of the brake rotating body by the input of the brake torque can be considered. . Therefore, since the increase / decrease in the internal pressure of the fluid chamber becomes abrupt according to the temperature change, it is important to reduce the increase / decrease width in order to avoid a decrease in durability.

JP 2008-51093 A

  However, since fresh air outside the housing flows into the fluid chamber inside the housing partially filled with the magnetorheological fluid in the actuator of the device of Patent Document 1, every time the temperature drops, Degradation such as oxidation is likely to occur in the contacted magnetorheological fluid. When the magnetorheological fluid deteriorates in this way, the input characteristics of the brake torque by the fluid, and hence the engine phase adjustment characteristics, change, leading to a decrease in reliability.

  The present invention has been made in view of these problems, and an object of the present invention is to provide a valve timing adjusting device that ensures both durability and reliability.

  The invention according to claim 1 is a valve timing adjusting device that adjusts the valve timing of a valve that opens and closes a camshaft by torque transmission from a crankshaft in an internal combustion engine, wherein a fluid chamber isolated from the outside is provided inside And a magnetorheological fluid that is sealed in a fluid chamber and changes its viscosity when a magnetic field is applied, and the viscosity of the magnetorheological fluid is variable by applying a magnetic field to the magnetorheological fluid in the fluid chamber. A viscosity control means for controlling, a brake rotating body that is rotatably supported by the housing and is in contact with the magnetorheological fluid in the fluid chamber, and receives a brake torque according to the viscosity of the magnetorheological fluid; A phase adjustment mechanism that links and adjusts the engine phase according to the brake torque input to the brake rotating body, and is supported movably by a housing or the brake rotating body. Exposed to the body chamber, characterized in that it comprises a movable body to increase or decrease the volume of the fluid chamber by movement in accordance with increase or decrease of the internal pressure of the fluid chamber.

  According to the invention described in claim 1, in the fluid chamber formed inside the casing and enclosing the magnetorheological fluid, the magnetorheological fluid expands and contracts due to a temperature change, and the internal pressure increases or decreases. The movable body exposed to the fluid chamber moves to increase or decrease the volume. According to such volume increase / decrease, the increase / decrease width of the internal pressure of the fluid chamber is reduced, so that deformation of the casing and the brake rotating body can be avoided. Moreover, since the increase / decrease width of the internal pressure of the fluid chamber can be reduced without introducing external air into the fluid chamber isolated from the outside of the housing, the magneto-rheological fluid in the fluid chamber is deteriorated by oxidation or the like. Is less likely to occur. Therefore, the engine that is adjusted according to the brake torque by the input characteristics of the brake torque input to the brake rotating body according to the viscosity of the magnetorheological fluid variably controlled by the application of the magnetic field, and by the phase adjusting mechanism linked to the brake rotating body. Regarding the phase adjustment characteristic, it is possible to avoid a change due to fluid deterioration. As described above, according to the first aspect of the present invention, it is possible to ensure both durability and reliability.

  According to the second aspect of the present invention, the brake rotating body has a rotating shaft that penetrates the housing inward and outward and is linked to the phase adjustment mechanism outside the housing, and the housing is located between the rotating shaft and the rotating shaft. It has a seal part to seal. As described above, in the configuration in which the rotating shaft of the brake rotating body that comes into contact with the magnetorheological fluid in the fluid chamber inside the housing passes through the housing inside and outside and is linked to the phase adjustment mechanism outside the housing, If the internal pressure of the fluid chamber exceeds the pressure resistance value of the seal portion that seals between the two, the magnetic viscous fluid may be leaked out of the housing. Such leakage of the magnetorheological fluid is undesirable because it changes the input characteristics of the brake torque and reduces the reliability. In order to increase the pressure resistance of the seal, it is conceivable to increase the tightening force of the seal against the rotating shaft, but in this case, the tightening force causes wear on the seal and the rotating shaft, resulting in a decrease in durability. There are concerns about other problems. However, when the internal pressure increase / decrease width of the fluid chamber is reduced by the action of the movable body as described above, the pressure resistance value of the seal portion is lowered within a range that does not cause a change in the input characteristics of the brake torque, and the seal portion with respect to the rotating shaft It is possible to suppress the wear by weakening the tension. Therefore, it can contribute to ensuring reliability and durability.

  According to the invention described in claim 3, the magnetorheological fluid is partially filled in the fluid chamber. In the fluid chamber of such an invention, as the magnetorheological fluid in the partially filled state or the remaining gas expands / contracts and the internal pressure increases / decreases, the movable body moves to increase / decrease the volume. Thus, deformation of the casing and the brake rotating body can be avoided. Furthermore, in the fluid chamber, even if the isolation from the outside should be insufficient, the remaining gas with a small flow resistance among the magnetorheological fluid in the partially filled state and the remaining gas is more likely to leak first. In addition, a change in brake torque input characteristics due to leakage of the magnetorheological fluid can be suppressed. According to the above, it can contribute to ensuring durability and reliability.

  According to the fourth aspect of the present invention, the casing or the brake rotating body that supports the movable body forms an outside air chamber into which air outside the casing flows in and out, and the movable body has the internal pressure and fluid chamber of the outside air chamber. It moves according to the pressure difference between the internal pressures. In such an invention, the internal pressure of the outside air chamber that is formed in the housing supporting the movable body or the brake rotating body and into which the air outside the housing flows in and out is substantially equal to the atmospheric pressure. Therefore, by moving the movable body according to the differential pressure between the atmospheric pressure that is the internal pressure of the outside air chamber and the internal pressure of the fluid chamber, the movement is accurately followed by the increase and decrease of the internal pressure of the fluid chamber. The volume can be increased or decreased. By such a follow-up action, the increase / decrease width of the internal pressure of the fluid chamber can be reliably reduced, and the effect of ensuring durability can be exhibited.

  According to the invention described in claim 5, the movable body is an elastically deformable diaphragm that isolates the outside air chamber and the fluid chamber, and deforms according to the differential pressure between the inside pressure of the outside air chamber and the inside pressure of the fluid chamber. . In such an invention, the elastically deformable diaphragm that separates the outside air chamber and the fluid chamber from each other as a movable body performs a deformation motion according to the differential pressure between the internal pressure of the outside air chamber and the internal pressure of the fluid chamber, The volume increase / decrease of the fluid chamber can be made to follow sensitively with respect to the internal pressure increase / decrease. Therefore, the increase / decrease width of the internal pressure of the fluid chamber can be made sufficiently small to enhance the durability ensuring effect.

  According to the sixth aspect of the present invention, the housing supports the fluid chamber partition member that partitions the fluid chamber together with the diaphragm as a movable body, and the diaphragm sandwiched between the fluid chamber partition member. An outside air chamber partitioning member that partitions the outside air chamber between the opposite side and the diaphragm. In such an invention, the diaphragm as a movable body that partitions the fluid chamber in which the magnetorheological fluid is sealed together with the fluid chamber partition member of the housing easily secures a large pressure receiving area for receiving the internal pressure of the fluid chamber. In addition, since the outside air chamber partition member of the housing partitions the outside air chamber on the opposite side of the fluid chamber from the diaphragm that partitions the fluid chamber, the differential pressure between the internal pressure of the outside air chamber and the internal pressure of the fluid chamber Accordingly, the diaphragm can be reliably deformed and moved. According to the above, the effect of ensuring the high durability by reducing the internal pressure increase / decrease width by the follow-up action of the increase / decrease in volume with respect to the internal pressure increase / decrease can be firmly established. In addition, the diaphragm that partitions the outside air chamber between the outside air chamber partition member on the side opposite to the fluid chamber that is partitioned together with the fluid chamber partition member is supported by being sandwiched between the partition members, so that The fluid chamber can be reliably isolated from the outside air chamber through which air flows in and out regardless of the deformation motion. Accordingly, it is possible to improve the reliability by avoiding a situation in which fresh air outside the casing flows into the fluid chamber from the outside air chamber and degrades the magnetorheological fluid.

  According to the invention described in claim 7, the outside air chamber partition member has a bottomed cylindrical shape with the bottom wall portion facing the diaphragm as the movable body with the outside air chamber interposed therebetween, and the diaphragm contacts the bottom wall portion. This regulates the deformation movement of the diaphragm. According to such an invention, the bottomed cylindrical outside air chamber partition member regulates the deformation movement of the diaphragm by the diaphragm as a movable body facing the outside air chamber being in contact with the bottom wall portion. It is possible to avoid a decrease in durability by deforming the diaphragm within a range that does not reach the limit.

  According to the invention described in claim 8, the outside air chamber partition member has a bottomed cylindrical shape with the bottom wall portion facing the diaphragm as the movable body with the outside air chamber interposed therebetween, and air outside the housing with respect to the outside air chamber. Are formed in the outer peripheral edge of the bottom wall. According to such an invention, the bottomed cylindrical outside air chamber partitioning member that faces the diaphragm as the movable body across the outside air chamber has a vent hole formed in the outer peripheral edge of the bottom wall portion. Therefore, while securing the air inflow / outflow path with respect to the outside air chamber, the protection area of the diaphragm by the bottom wall portion can be ensured to be large other than the outer peripheral edge portion, and the durability can be enhanced.

  According to the ninth aspect of the present invention, the movement suppressing member that suppresses the movement of the movable body toward the brake rotating body is provided between the brake rotating body and the movable body. According to such an invention, since the movement suppressing member is provided between the brake rotating body and the movable body and suppresses the movable body from moving toward the brake rotating body, the movable body reduces the internal pressure of the fluid chamber. Accordingly, the movable body can be brought into contact with the motion suppressing member so as not to come into contact with the brake rotator when greatly moving toward the brake rotator. Therefore, since the movable body can be prevented from coming into contact with the brake rotating body, which is a rotating object, undesired changes in valve timing due to damage to the movable body and generation of brake loss torque can be avoided.

  According to the tenth aspect of the present invention, the motion suppressing member for suppressing the movement of the diaphragm toward the brake rotating body is provided between the brake rotating body and the diaphragm, and the movement suppressing member is provided at least in the central portion of the diaphragm. They are arranged so as to overlap. In general, such a diaphragm deforms and moves in accordance with the differential pressure between the internal pressure of the outside air chamber and the internal pressure of the fluid chamber, so that the central part away from the movable part is greatly deformed toward the brake rotor. become. Therefore, according to the tenth aspect of the present invention, since at least the motion suppressing member overlaps the central portion of the diaphragm, the diaphragm can be reliably brought into contact with the motion suppressing member so as not to contact the brake rotating body efficiently. .

  According to the eleventh aspect of the present invention, a communication passage is formed around the motion suppression member or the motion suppression member to communicate the diaphragm side of the fluid chamber sandwiching the motion suppression member and the brake rotor side of the fluid chamber. . According to such an invention, the space on the diaphragm side of the fluid chamber located so as to sandwich the motion suppressing member and the space on the brake rotating body side of the fluid chamber are connected by the communication path. Despite the existence, both of the spaces can be moved back and forth through the communication path, and the behavior of the fluid is not greatly hindered. Thereby, the apparatus which can transmit the internal pressure fluctuation | variation of a fluid chamber appropriately to a diaphragm, and can avoid the damage of a diaphragm is obtained.

  According to the twelfth aspect of the present invention, the outside air chamber partition member is a member having a higher thermal conductivity than the fluid chamber partition member. In general, when the internal pressure of the fluid chamber increases due to a temperature rise, the diaphragm pressed against the outside air chamber partition member is thermally deformed when the state in which the heat of the fluid chamber is hardly released to the outside continues. Therefore, according to the twelfth aspect of the present invention, the heat of the fluid chamber is transmitted to the outside air chamber partition member having higher thermal conductivity than the fluid chamber partition member via the diaphragm and the outside air chamber, and is easily released to the outside. Therefore, the diaphragm is cooled. Therefore, the thermal deformation of the diaphragm can be reduced, and the deformation characteristics of the diaphragm following the volume increase / decrease of the fluid chamber can be maintained.

  According to a thirteenth aspect of the present invention, the outside air chamber partition member includes fins that radiate the heat of the outside air chamber to the outside. According to such an invention, as in the invention of the twelfth aspect, the heat of the fluid chamber is released to the outside from the fin formed in the outside air chamber partition member via the diaphragm and the outside air chamber. Cooling can be promoted. Therefore, the thermal deformation of the diaphragm can be reduced, and the deformation characteristics of the diaphragm following the volume increase / decrease of the fluid chamber can be maintained.

  According to the fourteenth aspect of the present invention, the movable body is a piston that can reciprocate between the outside air chamber and the fluid chamber, and reciprocates according to the differential pressure between the internal pressure of the outside air chamber and the internal pressure of the fluid chamber. In such an invention, the piston that can reciprocate between the outside air chamber and the fluid chamber reciprocates according to the pressure difference between the inside pressure of the outside air chamber and the inside pressure of the fluid chamber as a movable body, thereby increasing or decreasing the inside pressure of the fluid chamber. On the other hand, the volume increase / decrease of the fluid chamber can be made to follow sensitively. Therefore, the increase / decrease width of the internal pressure of the fluid chamber can be made sufficiently small to enhance the durability ensuring effect.

  According to the invention described in claim 15, the brake rotating body has a rotating shaft that penetrates the housing inward and outward and is linked to a phase adjusting mechanism outside the housing, and the rotating shaft has a piston as a movable body. Cylinder holes that slidably support along the penetrating direction in the housing and partition the outside air chamber and the fluid chamber are formed on both sides sandwiching the piston. In such an invention, the cylinder hole of the rotating shaft linked to the phase adjusting mechanism outside the housing supports the piston as the movable body in sliding contact along the penetrating direction of the rotating shaft passing through the housing in and out. It is easy to ensure a long reciprocating stroke in the penetration direction. Moreover, since the cylinder hole partitions the outside air chamber and the fluid chamber on both sides of the piston, the piston can be reliably reciprocated according to the differential pressure between the inside pressure of the outside air chamber and the inside pressure of the fluid chamber. According to the above, the effect of ensuring the high durability by reducing the internal pressure increase / decrease width by the follow-up action of the increase / decrease in volume with respect to the internal pressure increase / decrease can be firmly established.

  According to a sixteenth aspect of the present invention, the seal member for sealing between the piston and the cylinder hole is provided. According to such an invention, the cylinder holes communicating with the outside air chamber and the fluid chamber on both sides sandwiching the piston are sealed with the piston by the sealing member. The fluid chamber can be reliably isolated from the chamber regardless of the reciprocating motion of the piston. Therefore, reliability can be improved by avoiding a situation in which fresh air outside the casing flows from the outside air chamber into the fluid chamber through the cylinder hole and degrades the magnetorheological fluid.

It is sectional drawing which shows the valve timing adjustment apparatus of 1st embodiment. It is sectional drawing which shows the actuator of FIG. FIG. 3 is a sectional view taken along line III-III in FIG. 1. It is IV-IV sectional drawing of FIG. It is a VV arrow line view of FIG. It is sectional drawing which shows another operation state about the actuator of FIG. It is a figure which shows the actuator of the valve timing adjustment apparatus of 2nd embodiment, Comprising: It is sectional drawing corresponding to FIG. It is a VIII-VIII arrow line view of FIG. It is a modification of FIG. It is a figure which shows the actuator of the valve timing adjustment apparatus of 3rd embodiment, Comprising: It is sectional drawing corresponding to FIG. It is a XI-XI arrow line view of FIG. It is a figure which shows the actuator of the valve timing adjustment apparatus of 4th embodiment, Comprising: It is sectional drawing corresponding to FIG. It is sectional drawing which shows another operation state about the actuator of FIG.

  A plurality of modes for carrying out the present invention will be described below with reference to the drawings. In each embodiment, parts corresponding to the matters described in the preceding embodiment may be denoted by the same reference numerals, and redundant description may be omitted. When only a part of the configuration is described in each mode, the other modes described above can be applied to the other parts of the configuration. Not only combinations of parts that clearly show that combinations are possible in each embodiment, but also a combination of the embodiments even if they are not clearly shown unless there is a problem with the combination. It is also possible.

(First embodiment)
FIG. 1 shows a valve timing adjusting apparatus 1 according to a first embodiment of the present invention. The valve timing adjusting device 1 adjusts the valve timing of a valve that opens and closes the camshaft 2 by torque transmission from a crankshaft (not shown) in an internal combustion engine. The valve timing adjusting device 1 is mounted on a vehicle and installed in a transmission system that transmits engine torque from a crankshaft of an internal combustion engine to a camshaft 2. Here, the camshaft 2 shown in FIG. 1 mainly opens and closes an intake valve (not shown) in the “valve” of the internal combustion engine, and the valve timing adjusting device 1 controls the valve timing of the intake valve. Adjust it.

(Basic part)
First, the basic part of the first embodiment will be described. The valve timing adjusting device 1 according to the first embodiment includes an actuator 100, an energization control circuit 200, a phase adjusting mechanism 300, and the like, and adjusts the engine phase as a relative phase of the camshaft 2 with respect to the crankshaft, thereby enabling an internal combustion engine. The valve timing suitable for is realized.

(Actuator)
As shown in FIGS. 1 and 2, the actuator 100 is an electric fluid brake, and includes a housing 110, a brake rotating body 130, and a solenoid coil 150.

  The casing 110 has a hollow shape as a whole, and includes a fixing member 111 and a fluid chamber partition member 112. The fixing member 111 is formed of a magnetic material into an annular plate shape, and is fixed to a chain case (not shown) that is a fixing node of the internal combustion engine. The fluid chamber partition member 112 is formed of a magnetic material into a bottomed cylindrical shape, and is coaxially disposed at a location on the opposite side of the phase adjustment mechanism 300 with the fixing member 111 interposed therebetween. The fluid chamber partition member 112 is screwed to the fixing member 111, thereby forming a fluid chamber 114 between the fluid chamber partition member 112 and the fixing member 111 inside the housing 110.

  The brake rotating body 130 is formed by mutually fixing a shaft member 131 and a magnetic rotating member 132. The shaft member 131 is formed of a metal in a shaft shape and penetrates the housing 110 in and out. The fixing member 111 through which the shaft member 131 passes in the housing 110 is provided with a bearing portion 115 formed of a radial bearing, and the shaft member 131 is rotatably supported by the bearing portion 115. One end 131 a of the shaft member 131 extending to the outside of the housing 110 is connected to the external phase adjustment mechanism 300. As a result, the brake rotating body 130 rotates counterclockwise in FIGS. 3 and 4 when the engine torque output from the crankshaft is transmitted from the phase adjusting mechanism 300 during operation of the internal combustion engine.

  As shown in FIG. 2, the magnetic rotating member 132 is made of a magnetic material and has a shaft portion 133 and a rotor portion 134. The cylindrical shaft portion 133 is concentrically fitted and fixed to an end portion 131 b opposite to the end portion 131 a connected to the phase adjustment mechanism 300 in the shaft member 131, and the inner side of the housing 110 with respect to the bearing portion 1115. Adjacent to. A seal portion 113 made of an oil seal is provided on the fixing member 111 on the outer peripheral side of the shaft portion 133, and the space between the housing 110 and the shaft portion 133 is sealed by the seal portion 113.

  An annular plate-shaped rotor portion 134 is provided concentrically on the outer peripheral side of the shaft portion 133, and is located in the fluid chamber 114 inside the housing 110 at a position opposite to the bearing portion 115 with the seal portion 113 interposed therebetween. Contained. Thereby, in the fluid chamber 114, the portion sandwiched between the rotor portion 134 and the fixing member 111 forms the magnetic gap 120, and the portion sandwiched between the rotor portion 134 and the bottom wall portion 112 a of the fluid chamber partition member 112 is A magnetic gap 122 is formed.

  In this manner, the magnetorheological fluid 140 is enclosed in the fluid chamber 114 forming the magnetic gaps 120 and 122 together with air in a partially filled state. Here, the magnetorheological fluid 140 is a kind of functional fluid, and is formed by suspending magnetic particles in a liquid base material. As the base material of the magnetorheological fluid 140, a liquid non-magnetic material such as oil is used, and more preferably, the same type of oil as the lubricating oil of the internal combustion engine is used. As the magnetic particles of the magnetorheological fluid 140, for example, a powdered magnetic material such as carbonyl iron is used. In the magnetorheological fluid 140 having such a component structure, the apparent viscosity increases and changes in accordance with the strength of the applied magnetic field, and the shear viscosity is proportional to the viscosity and inversely proportional to the size of the space where the magnetorheological fluid 140 exists. The characteristic of increasing stress appears.

  The solenoid coil 150 is formed by winding a metal wire around the outer periphery of a cylindrical bobbin 152 and is concentrically disposed on the outer periphery of the rotor portion 134. The solenoid coil 150 is held by the fixing member 11 and the fluid chamber partition member 112 via the bobbin 152 and the spacer 154. The solenoid coil 150 is excited by energization to generate a magnetic field so as to form a magnetic flux that sequentially passes through the fixed member 111, the magnetic gap 120, the rotor part 134, the magnetic gap 122, and the fluid chamber partition member 112.

  Therefore, when the solenoid coil 150 generates a magnetic field during the rotation of the brake rotating body 130, the magnetorheological fluid 140 is attracted and flows into the magnetic gaps 120 and 122 and receives the generated magnetic field. As a result, between the elements 110 and 130 that are in contact with the magnetorheological fluid 140 of the magnetic gaps 120 and 122, the brake torque that brakes the rotor portion 134 by shear stress proportional to the viscosity of the magnetorheological fluid 140 to which a magnetic field is applied. Occurs in the clockwise direction of FIGS. As described above, in the present embodiment, the energized solenoid coil 150 generates a magnetic field, so that the brake torque corresponding to the viscosity of the magnetorheological fluid 140 is input to the brake rotating body 130.

(Energization control circuit)
The energization control circuit 200 shown in FIG. 1 is mainly composed of a microcomputer, and is arranged outside the actuator 100 and is electrically connected to the solenoid coil 150 and the vehicle battery 4. While the internal combustion engine is stopped, the energization control circuit 200 is in a state where the energization to the solenoid coil 150 is cut off by the interruption of the power supply from the battery 4. Therefore, at this time, no magnetic field is generated by the solenoid coil 150, and the brake torque input to the brake rotating body 130 is lost.

  On the other hand, during operation of the internal combustion engine, the energization control circuit 200 generates a magnetic field to be applied to the magnetorheological fluid 140 by controlling the energization current to the solenoid coil 150 while supplying power from the battery 4. Therefore, at this time, the viscosity of the magnetorheological fluid 140 is variably controlled, and the brake torque input to the brake rotating body 130 is set to increase or decrease following the energization current to the solenoid coil 150.

(Phase adjustment mechanism)
As shown in FIG. 1, the phase adjustment mechanism 300 includes a drive rotator 10, a driven rotator 20, an assist member 30, a planet carrier 40, and a planetary gear 50.

  The drive rotator 10 is formed by screwing together a gear member 12 and a sprocket 13 which are both cylindrical. The inner peripheral portion of the gear member 12 forms a drive side internal gear portion 14. The sprocket 13 is linked to the crankshaft by an annular timing chain being spanned between the plurality of teeth 16 on the outer peripheral portion thereof and the plurality of teeth on the crankshaft. Therefore, when the engine torque output from the crankshaft during operation of the internal combustion engine is input to the sprocket 13 through the timing chain, the drive rotor 10 is interlocked with the crankshaft in the counterclockwise direction of FIGS. Rotate.

  As shown in FIG. 1, the driven rotor 20 has a cylindrical shape and is concentrically disposed on the inner peripheral side of the sprocket 13. An outer peripheral portion of the driven rotor 20 forms a driven side internal gear portion 22. The inner peripheral portion of the driven rotating body 20 forms a connecting portion 24 that is coaxially fixed to the camshaft 2 by bolts. Accordingly, the driven rotator 20 can be rotated counterclockwise in FIG. 4 in conjunction with the camshaft 2, and can be rotated relative to the drive rotator 10.

  As shown in FIG. 1, the assist member 30 is formed of a torsion coil spring and is disposed concentrically on the inner peripheral side of the sprocket 13. One end 31 of the assist member 30 is locked to the sprocket 13, and the other end 32 of the assist member 30 is locked to the connecting portion 24. The assist member 30 is twisted between the rotating bodies 10 and 20 to generate assist torque, and bias the driven rotating body 20 toward the retard side with respect to the driving rotating body 10.

  As shown in FIGS. 1, 3, and 4, the planetary carrier 40 has a cylindrical shape as a whole. In the planetary carrier 40, a transmission portion 41 to which brake torque is transmitted from the brake rotating body 130 of the actuator 100 is formed by an inner peripheral portion. The transmission part 41 arranged concentrically with respect to the rotary bodies 10 and 20 and the brake rotary body 130 has a plurality of fitting groove parts 42, and via joints 43 fitted into these fitting groove parts 42. The planet carrier 40 is connected to the shaft member 131 of the brake rotating body 130. As a result, the planet carrier 40 can rotate integrally with the brake rotator 130 and can rotate relative to the drive rotator 10.

  The planetary carrier 40 has an eccentric portion 44 that is eccentric with respect to the transmission portion 41 formed by an outer peripheral portion. The eccentric portion 44 is fitted concentrically on the inner peripheral side of the planetary gear 50 via a planetary bearing 45. Thereby, the planetary carrier 40 supports the planetary gear 50 so as to be capable of planetary movement according to the relative rotation of the planetary carrier 40 with respect to the driving-side internal gear portion 14. Here, the planetary motion refers to a planetary motion in which the planetary gear 50 revolves around the eccentric center line of the eccentric portion 44 and revolves in the rotation direction of the planet carrier 40.

  The planetary gear 50 has a cylindrical shape and is disposed concentrically with the eccentric portion 44. That is, the planetary gear 50 is arranged eccentrically with respect to the gear portions 14 and 22. The outer peripheral portion of the planetary gear 50 includes a drive-side external gear portion 52 that meshes with the drive-side internal gear portion 14 on the eccentric side with respect to the gear portions 14 and 22, and a driven gear that meshes with the driven-side internal gear portion 22 on the eccentric side. The side outer gear portion 54 is formed coaxially.

  The phase adjustment mechanism 300 having the above configuration adjusts the engine phase in accordance with the balance between the brake torque input to the brake rotating body 130, the assist torque of the assist member 30, and the fluctuation torque acting on the camshaft 2.

  Specifically, when the brake rotator 130 rotates at the same speed as that of the drive rotator 10 by holding the brake torque or the like and the planet carrier 40 does not rotate relative to the drive-side internal gear portion 14, the planetary gear 50 is It rotates with the rotators 10 and 20 without moving. Therefore, at this time, the engine phase is maintained.

  On the other hand, when the brake rotator 130 rotates at a lower speed than the drive rotator 10 due to an increase in brake torque or the like and the planet carrier 40 rotates relative to the retard side with respect to the drive-side internal gear portion 14, the planetary gear 50 moves in a planetary motion. As a result, the driven rotator 20 rotates relative to the drive rotator 10 toward the advance side. Therefore, at this time, the engine phase is advanced.

  On the other hand, when the brake rotator 130 rotates at a higher speed than the drive rotator 10 due to a decrease in brake torque or the like, and the planetary carrier 40 rotates relative to the advance side with respect to the drive-side internal gear portion 14, the planetary gear 50 rotates to the planetary gear. The driven rotator 20 moves and rotates relative to the drive rotator 10 toward the retard side. Therefore, at this time, the engine phase is retarded.

(Characteristic part)
Next, the characteristic part of 1st embodiment is demonstrated in detail. The actuator 100 of the first embodiment shown in FIGS. 1 and 2 is provided with a diaphragm 160 exposed to the fluid chamber 114 inside the housing 110 in which the magnetorheological fluid 140 is enclosed.

  As shown in FIG. 2, the diaphragm 160 is formed in a circular thin film shape by an elastically deformable material, and is coaxially disposed on the opposite side of the fixed member 111 across the bottom wall portion 112 a of the fluid chamber partition member 112. Yes. The outer peripheral edge of the diaphragm 160 is supported by the peripheral portion of the exposed window 112b that is formed in the annular plate-like bottom wall 112a of the fluid chamber partition member 112 and exposes the fluid chamber 114. Yes. Thereby, the diaphragm 160 isolates the fluid chamber 114 partitioned together with the fluid chamber partition member 112 and the fixing member 111 from the outside of the housing 110.

  The elastically deformable material forming the diaphragm 160 may be any material that is resistant to the magnetorheological fluid 140 of the fluid chamber 114 partially formed in the exposed window 112b. A material obtained by vapor-depositing a rubber material is used. The thickness of the diaphragm 160 can be appropriately set according to required elastic deformation characteristics, a forming material, and the like, but is set to about 0.5 mm to 1.5 mm, for example.

  In the actuator 100 of the first embodiment, as shown in FIGS. 1 and 2, an outside air chamber partition member 116 is provided in the housing 110.

  As shown in FIGS. 2 and 5, the outside air chamber partition member 116 is formed of a metal and has a bottomed cylindrical shape, and is coaxially disposed on the opposite side of the diaphragm 160 with respect to the bottom wall portion 112 a of the fluid chamber partition member 112. Has been. A flange portion 116b provided in the opening on the opposite side of the bottom wall portion 116a in the outside air chamber partition member 116 is fitted and fixed to the bottom wall portion 112a of the fluid chamber partition member 112. Thus, the outside air chamber partition member 116 supports the outer peripheral edge portion of the diaphragm 160 between the flange portion 116b and the fluid chamber partition member 112, and also supports the diaphragm 160 and the bottom wall portion 116a opposite thereto. A sandwiched outside air chamber 118 is formed. Further, in the outside air chamber partitioning member 116, vent holes 119 are formed through the outer peripheral edge of the bottom wall portion 116a at a plurality of locations at equal intervals in the circumferential direction. Accordingly, each vent hole 119 is opened outside the housing 110, and the outside air can flow into and out of the outside air chamber 118.

  The outside air chamber partitioning member 116 configured as described above has an outside air chamber 118 that is isolated from the fluid chamber 114 inside the housing 110 and communicates with the outside of the housing 110 through a plurality of vent holes 119, on the side opposite to the fluid chamber 114. And is partitioned between the diaphragm 160. As a result, in the first embodiment, the diaphragm according to the differential pressure between the internal pressure of the outside air chamber 118 that is substantially maintained at atmospheric pressure by the inflow and outflow of air outside the housing 110 and the internal pressure of the fluid chamber 114. 160 will be deformed.

  Specifically, when the magnetorheological fluid 140 in the partially filled state and the remaining air in the fluid chamber 114 expand due to temperature rise and the internal pressure of the fluid chamber 114 increases, the differential pressure between the internal pressures of the chambers 114 and 118 also increases. Increase. As a result, the diaphragm 160 exposed to the chambers 114 and 118 swells toward the bottom wall portion 116 a of the outside air chamber partition member 116 while allowing the air in the outside air chamber 118 to flow out from the vent holes 119. Therefore, at this time, the volume of the fluid chamber 114 increases as shown in FIG. 6, and an excessive increase in the internal pressure of the fluid chamber 114 is suppressed. In particular, when the diaphragm 160 swelled toward the bottom wall 116a comes into contact with the bottom wall 116a as shown in FIG. 6, the deformation movement of the diaphragm 160 is restricted. In such a first embodiment, the distance d (see FIG. 2) between the diaphragm 160 and the bottom wall portion 116a sandwiching the fluid chamber 114 is such that the internal pressure of the fluid chamber 114 does not always exceed the pressure resistance value of the seal portion 113. Deformation movement that does not reach the elastic limit at the time of contact with the bottom wall portion 116a is set by the diaphragm 160 so as to be realized.

  On the other hand, when the magnetorheological fluid 140 in the partially filled state and the remaining air in the fluid chamber 114 contract due to a temperature drop and the internal pressure of the fluid chamber 114 decreases, the differential pressure between the internal pressures of the chambers 114 and 118 also decreases. As a result, the diaphragm 160 exposed in each of the chambers 114 and 118 causes air to flow into the outside air chamber 118 from each vent hole 119 while restoring to the side opposite to the bottom wall portion 116a of the outside air chamber partition member 116. Therefore, at this time, the volume of the fluid chamber 114 decreases as shown in FIG. 2, and the internal pressure of the fluid chamber 114 returns to the atmospheric pressure side.

  In the fluid chamber 114 of the first embodiment described so far, as the magnetorheological fluid 140 and air expand and contract due to temperature changes and the internal pressure increases and decreases, the diaphragm 160 reliably deforms and the volume increases and decreases. Here, in particular, the volume increase / decrease of the fluid chamber 114 is realized by using elastic deformation of the diaphragm 160 according to the differential pressure between the atmospheric pressure of the outside air chamber 118 and the internal pressure of the fluid chamber 114. It will follow the increase and decrease accurately and sensitively. Moreover, since the substantial pressure receiving area of the diaphragm 160 with respect to the internal pressure of each chamber 118, 114 is defined by the exposed window 112b of the bottom wall portion 112a that can be largely formed in the fluid chamber partition member 112 of the housing 110, the fluid chamber The followability between the internal pressure increase / decrease 114 and the volume increase / decrease is increased. According to such a follow-up action, an excessive increase in the internal pressure of the fluid chamber 114 is suppressed and the increase / decrease width of the internal pressure is surely and sufficiently small, so that deformation of the casing 110 and the brake rotating body 130 can be avoided. Durability can be increased.

  Furthermore, the diaphragm 160 according to the first embodiment comes into contact with the bottom wall portion 116a of the outside air chamber partition member 116 in the casing 110 that supports the diaphragm 160, so that the deformation motion is regulated within a range that does not reach the elastic limit. It has become. Moreover, the diaphragm 160 is protected in a large area by a portion other than the outer peripheral edge portion that forms the vent hole 119 in the bottom wall portion 116a of the outside air chamber partitioning member 116 facing the diaphragm 160. For these reasons, damage to the diaphragm 160 can be avoided and durability can be enhanced.

  In the first embodiment, the fluid chamber 114 is isolated from the outside of the housing 110 and the outside air chamber 118 into which air flows from the outside. Therefore, the problem that air outside the casing 110 flows into the casing 110 and the magnetorheological fluid 140 in the fluid chamber 114 is deteriorated due to oxidation or the like is hardly caused. Moreover, even if the fluid chamber 114 is insufficiently isolated, the latter, which has a lower flow resistance, leaks out first in the partially filled magnetorheological fluid 140 and the remaining air in the fluid chamber 114. It is easy to do. From these, regarding the input characteristics of the brake torque according to the viscosity of the magnetorheological fluid 140 and the adjustment characteristics of the engine phase according to the brake torque, the reliability of the magnetorheological fluid 140 is suppressed by suppressing changes due to deterioration or leakage. It can be increased.

  In addition, as described above, in the first embodiment in which the increase / decrease width of the internal pressure of the fluid chamber 114 is small, the input characteristics of the brake torque due to leakage of the magnetorheological fluid 140 due to the deformation of the seal portion 113 are not generated. The pressure resistance value of the seal portion 113 can be set low. Therefore, not only the reliability is improved, but also the pressure of the seal portion 113 against the shaft portion 133 of the brake rotating body 130 is weakened, and the occurrence of wear due to the frictional resistance between the seal portion 113 and the shaft portion 133 is suppressed. Since it can, durability can also be improved. Further, by reducing the tightening force of the seal portion 113, the rotation loss of the camshaft 2 corresponding to the torque cross caused by the frictional resistance between the seal portion 113 and the shaft portion 133 can be reduced when the brake torque disappears, and the internal combustion engine This will also improve the fuel economy.

  As described above, according to the first embodiment, both high durability and high reliability can be ensured at the same time, and the fuel efficiency can be improved. In the first embodiment described above, the solenoid coil 150 and the energization control circuit 200 jointly constitute the “viscosity control means” described in the claims, and the diaphragm 160 is the “movable” described in the claims. Corresponds to "body". Further, in the first embodiment, among the brake rotating body 130, the magnetic material sealed between the housing 110 by the shaft member 131 that penetrates the housing 110 inward and outward and is linked to the phase adjustment mechanism 300 and the seal portion 113. The shaft portion 133 of the rotating member 132 jointly constitutes the “rotating shaft” described in the claims.

(Second embodiment)
As shown in FIG. 7, the second embodiment of the present invention is a modification of the first embodiment. The actuator 100A of the second embodiment includes a motion suppressing member 170 that suppresses the movement of the diaphragm 161 toward the brake rotating body between the brake rotating body 130 and the diaphragm 161 with respect to the actuator 100 of the first embodiment. Is different. Hereinafter, differences from the first embodiment will be described.

  The diaphragm 161 is a plate-like elastically deformable member formed of an elastically deformable material and having a circular thin film-like bottom portion 161a. The diaphragm 161 is exposed to the fluid chamber 114, and is disposed coaxially on the opposite side of the fixed member 111 across the bottom wall portion 112 a of the fluid chamber partition member 112. The outer peripheral edge portion of the diaphragm 161 that is radially expanded from the peripheral edge portion of the bottom portion 161a is formed on the annular plate-like bottom wall portion 112a of the fluid chamber partition member 112, and is a peripheral portion of the exposed window 112b that exposes the fluid chamber 114. And the flange portion 116b of the outside air chamber partition member 116, and is supported over the entire circumference. Thereby, the diaphragm 161 isolates the fluid chamber 114 partitioned together with the fluid chamber partitioning member 112 and the fixing member 111 from the outside of the housing 110. Therefore, the diaphragm 161 is deformed according to the differential pressure between the internal pressure of the outside air chamber 118 and the internal pressure of the fluid chamber 114 which are substantially maintained at atmospheric pressure by the inflow and outflow of air outside the housing 110. . Further, the outer peripheral edge portion of the diaphragm 161 has a bottom portion in a state where the internal pressure of the fluid chamber 114 is equal to the internal pressure of the external air chamber 118, that is, in a state where the bottom portion 161a is not deformed so as to swell toward the fluid chamber partition member 112. It is located closer to the fluid chamber partition member 112 than 161a.

  The elastically deformable material forming the diaphragm 161 may be any material that is resistant to the magnetorheological fluid 140 in the fluid chamber 114 partially formed in the exposed window 112b. A material obtained by vapor-depositing a rubber material is used. Further, the thickness of the diaphragm 161 can be appropriately set according to required elastic deformation characteristics, a forming material, and the like, but is set to, for example, about 0.5 mm to 1.5 mm.

  The motion suppressing member 170 is a thin plate portion that extends inward from the bottom wall portion 112 a of the fluid chamber partition member 112 to the shaft portion side of the brake rotating body 130, and is formed integrally with the fluid chamber partition member 112. The movement suppressing member 170 is disposed substantially parallel to the bottom 161a of the diaphragm 161 with a predetermined distance. The motion suppressing member 170 is a member that crosses the fluid chamber 114 in a plane orthogonal to the axial direction of the brake rotator 130, and bisects the fluid chamber 114 in the axial direction of the brake rotator 130. The space divided into two is a space formed on the diaphragm side of the fluid chamber 114 and the brake rotating body side of the fluid chamber 114, and is formed so as to sandwich the motion suppressing member 170.

  As shown in FIG. 8, the motion suppressing member 170 is disposed so as to overlap at least the central portion of the diaphragm 161. The central portion of the diaphragm 161 is a portion located farthest inward from the outer peripheral edge of the diaphragm 161 supported by the peripheral portion of the exposure window 112b. The central part of the diaphragm 161 is, for example, the center part of a circle when the diaphragm 161 is circular, and the diagonal line at the farthest position from the outer peripheral part when the diaphragm 161 is a polygonal shape such as a quadrangle. is there. When the central portion of the diaphragm 161 is deformed and moved toward the brake rotating body in accordance with the differential pressure between the internal pressure of the fluid chamber 114 and the internal pressure of the external air chamber 118, the central portion of the diaphragm 161 comes into contact with the tongue-like motion suppressing member 170. The amount of deformation is regulated.

  As shown in FIG. 8, the movement suppressing member 170 extends in a tongue shape from the bottom wall portion 112 a to at least the central portion of the diaphragm 161. The peripheral edge portion 171 of the movement suppressing member 170 formed in a tongue shape is separated from the bottom wall portion 112a of the portion excluding the starting point of the movement suppressing member 170, and the separated portion around the movement suppressing member 170 is In addition, a communication path that connects the diaphragm side of the fluid chamber 114 and the brake rotor side of the fluid chamber 114 is configured.

  Further, the movement suppressing member 170 may have a form like the movement suppressing member 170A shown in FIG. The motion suppressing member 170A is a circular thin plate member that extends inward from the bottom wall portion 112a and forms the fluid chamber 114 in a cross section perpendicular to the axial direction of the brake rotating body 130. And is integrally formed. Furthermore, a plurality of communication holes 172 penetrating in the thickness direction are formed in the motion suppressing member 170A at equal intervals. The communication hole 172 constitutes a communication path that connects the diaphragm side of the fluid chamber 114 formed so as to sandwich the motion suppressing member 170 and the brake rotor side of the fluid chamber 114. The fluid that forms the internal pressure of the fluid chamber 114 (the liquid phase component and the gas phase component of the magnetorheological fluid 140) moves between the diaphragm side of the fluid chamber 114 and the brake rotor side of the fluid chamber 114 via the communication hole 172. Can be done. The movement suppressing member 170 </ b> A has no communication hole 172 at a position at least overlapping with the central portion of the diaphragm 161. The central portion of the diaphragm 161 is a portion where the communication hole 172 of the motion suppressing member 170A is not formed when the diaphragm 161 is deformed and moved toward the brake rotating body according to the differential pressure between the internal pressure of the fluid chamber 114 and the internal pressure of the external air chamber 118. The amount of deformation is regulated by contact.

  The outside air chamber partition member 116 is preferably a member having a higher thermal conductivity than the fluid chamber partition member 112. The heat conductivity here is a value obtained by dividing the amount of heat flowing per second in a unit area perpendicular to the heat flow by the temperature difference of the unit length. That is, the outside air chamber partition member 116 is configured so that the amount of heat flowing per second in a unit area perpendicular to the heat flow with respect to the temperature difference of the unit length is larger in the outside air chamber partition member 116 than in the fluid chamber partition member 112. The material etc. are comprised. Since the outside air chamber partition member 116 has a higher thermal conductivity than the fluid chamber partition member 112, the heat equally applied to the outside air chamber partition member 116 and the fluid chamber partition member 112 is directed toward the outside air chamber partition member 116. Since it is transmitted quickly, it is easier to flow to the outside air chamber partition member 116 than to the fluid chamber partition member 112. The fluid chamber partition member 112 is made of an iron-based member (low carbon steel such as S10C) in order to form a magnetic circuit. Therefore, as a constituent member of the outside air chamber partition member 116, for example, aluminum, magnesium, copper, an alloy thereof, or the like having a higher thermal conductivity than the iron-based member is used.

  In the actuator 100A, when the magnetorheological fluid 140 partially filled in the fluid chamber 114 and the remaining air expand due to temperature rise and the internal pressure of the fluid chamber 114 increases, the differential pressure between the internal pressures of the chambers 114 and 118 also increases. To do. As a result, the diaphragm 161 exposed to the respective chambers 114 and 118 swells toward the bottom wall portion 116 a side of the outdoor air chamber partition member 116 while allowing the air in the outdoor air chamber 118 to flow out from the respective vent holes 119. Therefore, at this time, the volume of the fluid chamber 114 is increased, and an excessive increase in the internal pressure of the fluid chamber 114 is suppressed. Further, when the diaphragm 161 swelled toward the bottom wall 116a comes into contact with the bottom wall 116a, the deformation motion of the diaphragm 161 is restricted.

  On the other hand, when the magnetorheological fluid 140 in the partially filled state and the remaining air in the fluid chamber 114 contract due to a temperature drop and the internal pressure of the fluid chamber 114 decreases, the differential pressure between the internal pressures of the chambers 114 and 118 also decreases. As a result, the diaphragm 161 exposed in each of the chambers 114 and 118 is restored to the side opposite to the bottom wall portion 116a of the outside air chamber partition member 116, and air flows into the outside air chamber 118 from each vent hole 119. At this time, the volume of the fluid chamber 114 decreases, and the internal pressure of the fluid chamber 114 returns to the atmospheric pressure side. When the degree of decrease in the internal pressure of the fluid chamber 114 increases, a portion deformed to the opposite side of the diaphragm 161 may come into contact with the brake rotating body 130. When the engine operates in such a contact state, the diaphragm 161 may be worn and damaged due to friction with the rotating brake body 130 rotating. In addition, if brake loss torque is excessively generated at this time, the valve timing is changed, leading to deterioration of drivability and fuel consumption.

  According to the second embodiment, the diaphragm 161 is restricted in deformation motion within a range not reaching the elastic limit by contacting the motion suppressing member 170 interposed between the diaphragm 161 and the brake rotator, and the brake rotator. Contact with 130 is prevented. Therefore, the diaphragm 161 is protected in a large area by the bottom wall portion 116a of the outside air chamber partitioning member 116 facing the bottom portion 161a on the outside air chamber partitioning member 116 side, and at the center of the bottom portion 161a on the brake rotating body 130 side. It is protected by the opposing movement suppression member 170. Therefore, the actuator 100A is configured to avoid the damage of the diaphragm 161 due to the elastic limit or wear and to enhance the durability.

  As described above, according to the second embodiment, both high durability and high reliability can be ensured while contributing to improvement in fuel consumption. In the second embodiment described above, the diaphragm 161 corresponds to a “movable body” recited in the claims.

  Further, the motion suppressing member 170 is provided so as to overlap at least the central portion of the diaphragm 161 in the axial direction. The diaphragm 161 that deforms and moves in accordance with the differential pressure between the internal pressure of the outside air chamber 118 and the internal pressure of the fluid chamber 114 is largely deformed particularly toward the brake rotator 130 side at the central portion away from the movable portion. The diaphragm 161 can be reliably brought into contact with the motion suppressing member 170, and the wear preventing effect of the diaphragm 161 can be efficiently realized.

  In addition, a fluid chamber having the motion suppression member 170 sandwiched by a space between the peripheral edge portion 171 of the motion suppression member 170 and the bottom wall portion 112a of the body chamber partition member 112 or a communication hole 172 formed in the motion suppression member 170A. A communication path that connects the diaphragm side of 114 and the brake rotor side is formed. As a result, the space on the diaphragm side of the fluid chamber 114 and the space on the brake rotator side are connected, so that the fluid constituting the internal pressure of the fluid chamber 114 can travel back and forth between the two spaces, contributing to the formation of the internal pressure. The behavior of is not greatly hindered. Therefore, it is possible to obtain an actuator that can simultaneously transmit the internal pressure fluctuation of the fluid chamber 114 to the appropriate diaphragm 161 and protect the diaphragm 161 due to the presence of the motion suppressing member.

  When the outside air chamber partition member 116 is formed of a member having a higher thermal conductivity than that of the fluid chamber partition member 112, the heat transferred from the liquid phase component and the gas phase component of the magnetorheological fluid 140 to the diaphragm 161 is outside air. It is transmitted to the chamber partition member 116 quickly, and is easily discharged to the outside from the outer surface of the outside air chamber partition member 116. When the internal pressure of the fluid chamber 114 increases as the temperature rises, the diaphragm 161 is deformed toward the outside air chamber partition member 116, and when this degree is large, the diaphragm 161 is pressed against the bottom wall portion 116a of the outside air chamber partition member 116. It will be. The diaphragm 161 in contact with the bottom wall portion 116a continues contact with the bottom wall portion 116a while the transferred heat of the fluid chamber 114 is not released to the outside but is stored in the inside, and is finally fatigued by thermal deformation. And then hesitates.

  The heat of the diaphragm 161 flows from the site to the inside of the outside air chamber partition member 116 faster than the fluid chamber partition member 112 supporting the diaphragm 161 to the outside air chamber partition member 116 with which the diaphragm 161 is in contact. The partition member 116 is discharged to the outside from the outer surface in contact with the outside air. Thereby, the heat of the diaphragm 161 is positively taken away to the outside air chamber partition member 116 side, so that the cooling of the diaphragm 161 is promoted. Therefore, sag due to thermal deformation of the diaphragm 161 can be suppressed, and the function and characteristics of the diaphragm 161 can be maintained for a long time.

(Third embodiment)
The third embodiment of the present invention is a modification of the second embodiment. The actuator 100B of the third embodiment is different from the actuator 100A of the second embodiment in that a fin 116c that radiates heat of the outside air chamber 118 to the outside is provided on the outside air chamber partition member 116A. According to the fin 116c, in the second embodiment, the outside air chamber partition member 116 is configured with a member having a higher thermal conductivity than the fluid chamber partition member 112, and the same effect of cooling the diaphragm 161 is obtained. is there. Hereinafter, differences from the second embodiment will be described.

  As shown in FIGS. 10 and 11, in the actuator 100B, a plurality of fins 116c are provided in the outside air chamber partition member 116A. Each fin 116c is a flat plate-like portion projecting a predetermined length outward from the outer surfaces of the bottom wall portion 11a and the flange portion 116b of the outside air chamber partition member 116A, and a plurality of fins that cross the outer surface of the outside air chamber partition member 116A. It has a rail shape. The rail-shaped fins 116c are parallel to each other and arranged at equal intervals. Each fin 116c may be made of the same material or a different material with respect to the outside air chamber partition member 116A, but is made of a material having a small heat conduction loss from the outside air chamber partition member 116A.

  According to the third embodiment, the heat transferred from the liquid phase component and the gas phase component of the magnetorheological fluid 140 to the diaphragm 161 is transferred to the outside air chamber partition member 116A, and the surface area of the outer surface of the outside air chamber partition member 116 is increased. The fins are actively released to the outside air. In particular, when the internal pressure of the fluid chamber 114 increases as the temperature rises, the diaphragm 161 is deformed to the outside air chamber partition member 116A side. When this degree is large, the diaphragm 161 is placed on the bottom wall portion 116a of the outside air chamber partition member 116A. Pressed. The heat transferred to the diaphragm 161 in contact with the bottom wall portion 116a is transferred from the contacted portion to the outside air chamber partition member 116A, and is conducted to the inside of the outside air chamber partition member 116A, except for the fins 116c and fins 116c. The outside air chamber partition member 116A in contact with the outside air is radiated to the outside.

  As a result, the heat of the diaphragm 161 is taken away from the diaphragm 161 by an amount of the heat radiation area increased by the fins 116c, and the cooling of the diaphragm 161 is promoted. Therefore, sag due to thermal deformation of the diaphragm 161 can be suppressed, and the function and characteristics of the diaphragm 161 can be maintained for a long time. Therefore, by reducing the thermal deformation of the diaphragm 161, the deformation characteristics of the diaphragm 161 that appropriately follow the internal pressure fluctuation of the fluid chamber 114 can be maintained for a long time.

  Further, the fin 116c is not limited to the rail shape shown in FIGS. 10 and 10 as long as the surface area of the portion integrated with the outside air chamber partitioning member 116A is increased. For example, the fin 116c may have a lattice shape, an annular shape, or the like. Good. According to this, since the air cooling effect of the outside air chamber partition member 116A is enhanced, the amount of heat radiation to the outside is increased, and the durability of the diaphragm 161 can be further improved.

  The outside air chamber partition member 116A may be formed of a member having a higher thermal conductivity than the fluid chamber partition member 112, as in the second embodiment. According to this, in addition to the increase in the heat radiation area by the fins 116c, an effect of positively transferring the heat of the diaphragm 161 to the outside air chamber partition member 116 side can be obtained.

(Fourth embodiment)
As shown in FIG. 12, the fourth embodiment of the present invention is a modification of the first embodiment. The actuator 500 of the fourth embodiment is not provided with the diaphragm 160 and the outside air chamber partition member 116. Instead, in the actuator 500, a magnetic gap is formed between the bottom wall portion 512 a of the fluid chamber partition member 512 in which the cap 512 c is fitted and fixed to the window 512 b and the fixing member 111 that forms the casing 510 together with the partition member 512. A fluid chamber 514 forming 120 and 122 is defined. Further, the actuator 500 is configured such that the piston 560 is supported by the shaft member 531 of the brake rotating body 530.

  Specifically, a cylindrical shaft hole 537 having a bottomed cylindrical hole extending in the penetrating direction is concentric with the metal shaft member 531 that penetrates the housing 510 inward and outward and is linked to the phase adjustment mechanism 300 outside the housing 510. Formed on top. One end 537 a of the cylinder hole 537 is open to the end surface of the shaft member 531 inside the housing 510.

  The shaft member 531 is further formed with a cylindrical vent hole 539 that is bent in an L shape. One end portion of the vent hole 539 opens on the inner peripheral surface of the cylinder hole 537 on the side of the bottom end portion 537b that is opposite to the opening end portion 537a. On the other hand, the other end of the vent hole 539 opens to the outer peripheral surface of the shaft member 531 outside the housing 510.

  The piston 560 is formed of a metal in a cylindrical shape, and is fitted concentrically with the cylinder hole 537. As a result, the piston 560 is slidably supported in a reciprocating manner along the penetrating direction of the shaft member 531 in the housing 510. A part of the fluid chamber 514 in which the magnetorheological fluid 140 is sealed in a partially filled state is formed in the cylinder hole 537 closer to the opening end 537a than the piston 560, and the piston 560 is exposed to the fluid chamber 514. ing. On the other hand, an outside air chamber 538 that communicates with the outside of the housing 510 through a vent hole 539 is formed in the cylinder hole 537 that is closer to the bottom end portion 537 b than the piston 560, and the piston 560 is exposed to the outside air chamber 538. Yes. As a result, air outside the casing 510 can flow into and out of the external air chamber 538 through the vent hole 539, and the internal pressure of the external air chamber 538 can be maintained at atmospheric pressure.

  O-rings 535 formed in an annular shape with rubber are respectively fitted and fixed to a plurality of annular groove portions 560a that continuously open in the circumferential direction on the outer peripheral surface of the piston 560. These O-rings 535 seal the space between the piston 560 and the cylinder hole 537, thereby isolating the fluid chamber 514 from the outside of the housing 510 and the outside air chamber 538.

  With the above configuration, the piston 560 reciprocates between the fluid chamber 514 and the outside air chamber 538 defined on both sides of the piston 560 according to the differential pressure between the internal pressures of the chambers 514 and 538. It becomes.

  Specifically, when the partially filled magnetorheological fluid 140 and the remaining air expand in the fluid chamber 514 due to temperature rise and the internal pressure of the fluid chamber 514 increases, the differential pressure between the internal pressures of the chambers 514 and 538 also increases. Increase. As a result, the piston 560 exposed to the chambers 514 and 538 moves toward the bottom end portion 537b of the cylinder hole 537 while allowing the air in the outside air chamber 538 to flow out of the vent hole 539. Therefore, at this time, the volume of the fluid chamber 514 increases as shown in FIG. 13, and an excessive increase in the internal pressure of the fluid chamber 514 is suppressed.

  On the other hand, when the magnetorheological fluid 140 in the partially filled state and the remaining air contract in the fluid chamber 514 due to a temperature drop and the internal pressure of the fluid chamber 514 decreases, the differential pressure between the internal pressures of the chambers 514 and 538 also decreases. As a result, the piston 560 exposed in the chambers 514 and 538 allows air to flow into the outside air chamber 538 from the vent hole 539 while moving toward the opening end 537a of the cylinder hole 537. Therefore, at this time, the volume of the fluid chamber 514 decreases as shown in FIG. 12, and the internal pressure of the fluid chamber 514 returns to the atmospheric pressure side.

  In the fluid chamber 514 of the second embodiment described so far, as the magnetorheological fluid 140 and air expand and contract due to temperature changes and the internal pressure increases and decreases, the piston 560 reliably reciprocates and the volume increases and decreases. Here, in particular, the volume increase / decrease of the fluid chamber 514 is realized by using a piston motion corresponding to the differential pressure between the atmospheric pressure of the outside air chamber 538 and the internal pressure of the fluid chamber 514, so And it will be sensitively following. Moreover, the cylinder hole 537 slides and supports the piston 560 along the penetrating direction of the shaft member 531 in the casing 510, so that the follow-up of the volume increase / decrease with respect to the internal pressure increase / decrease of the fluid chamber 114 is not hindered. A reciprocating stroke can be secured long in the penetration direction. According to such an action, an excessive increase in the internal pressure of the fluid chamber 514 is suppressed, and the increase / decrease width of the internal pressure is surely and sufficiently small. Therefore, the casing 510 and the brake rotator 530 are prevented from being deformed and durable. It can improve the sex.

  Furthermore, in the fourth embodiment, the fluid chamber 514 is isolated by the O-ring 535 between the piston 560 and the cylinder hole 537 from the outside of the housing 510 and the outside air chamber 538 into which air flows from the outside. Therefore, the problem that external air flows into the housing 510 forming the fluid chamber 514 and the magnetorheological fluid 140 in the fluid chamber 514 deteriorates due to oxidation or the like is hardly caused. Therefore, the change in the input characteristic of the brake torque, and hence the change in the engine phase adjustment characteristic according to the brake torque is suppressed, and the reliability is improved.

  Therefore, according to the fourth embodiment, both high durability and high reliability can be secured at the same time. In the fourth embodiment described above, the piston 560 corresponds to the “movable body” recited in the claims, and the O-ring 535 corresponds to the “seal member” recited in the claims. In the fourth embodiment, among the brake rotating body 530, the shaft member 531 penetrating the housing 510 in and out and connecting to the phase adjusting mechanism 300 and the magnetic seal sealed between the housing 510 by the seal portion 113 are used. The shaft portion 133 of the rotating member 132 jointly constitutes the “rotating shaft” described in the claims.

(Other embodiments)
Although a plurality of embodiments of the present invention have been described above, the present invention is not construed as being limited to these embodiments, and can be applied to various embodiments without departing from the scope of the present invention. .

  Specifically, in each of the first to fourth embodiments, the magnetorheological fluid 140 may be sealed in the fluid chambers 114 and 514 inside the casings 110 and 510 in a completely filled state. Further, in the first embodiment, according to the fourth embodiment, the diaphragm 160 is supported by the shaft member 531 of the brake rotating body 530, and inside the hole 537 on the opposite side to the fluid chamber 514 across the diaphragm 160, An outside air chamber 538 communicating with the vent hole 539 may be formed. Furthermore, in the fourth embodiment, in accordance with the first embodiment, the fluid chamber partition member 112 having a thick bottom wall portion 112a is supported by the piston 560, and the piston 560 is sandwiched between and opposite to the fluid chamber 514. On the side, the outside air chamber 118 communicating with the vent hole 119 may be partitioned by the outside air chamber partition member 116.

  In addition, in each of the first to fourth embodiments, the phase adjustment mechanism 300 is configured such that the rotating body 10 rotates in conjunction with the camshaft 2 and the rotating body 20 rotates in conjunction with the crankshaft. It is good. In addition to the planetary gear mechanism (differential gear mechanism) as described above, the phase adjusting mechanism 300 may be any of various types as long as the engine phase can be adjusted according to the rotation state of the brake rotating body 130 with respect to the rotating body 10. A mechanism can be used.

  In addition to the device that adjusts the valve timing of the intake valve, the present invention provides a device that adjusts the valve timing of the exhaust valve as a “valve”, and a device that adjusts the valve timing of both the intake valve and the exhaust valve. It can also be applied.

  The motion suppressing member 170 or the motion suppressing member 170A described in the second embodiment only needs to be formed with a wall portion that can contact the diaphragm 161 at a portion facing the central portion of the diaphragm 161. It is not limited to the shape described in the above. Further, the communication passage formed around the motion suppressing member 170 or in the motion suppressing member 170A has a cross-sectional shape (a cross-sectional shape orthogonal to the axial direction of the brake rotating body 130) in the shape described in the second embodiment. It is not limited. Further, the communication hole 172 formed in the motion suppressing member 170A is not limited to a circular shape, or may be a single communication hole.

DESCRIPTION OF SYMBOLS 1 Valve timing adjustment apparatus, 2 cam shaft, 10 Drive rotary body, 20 Driven rotary body, 30 Assist member, 40 Planet carrier, 50 Planet gear, 100,500 Actuator, 110,510 Housing | casing, 111 Fixing member, 112,512 Fluid chamber partition member, 112a, 512a Bottom wall portion, 112b Exposed window, 113 Seal portion, 114, 514 Fluid chamber, 115 Bearing portion, 116, 116A Outside air chamber partition member, 116a Bottom wall portion, 116b Flange portion, 116c Fin, 118,538 Outside air chamber, 119,539 Vent hole, 120,122 Magnetic gap, 130,530 Brake rotating body, 131,531 Shaft member (rotating shaft), 132 Magnetic rotating member, 133 Shaft portion (rotating shaft), 134 Rotor Part, 140 magnetorheological fluid, 150 solenoid carp (Viscosity control means), 160, 161 Diaphragm (movable body), 170, 170A Motion suppressing member, 172 communication hole (communication path), 200 energization control circuit (viscosity control means), 300 phase adjustment mechanism, 535 O-ring (seal) Member), 537 cylinder hole, 537a end / open end, 537b bottom end, 560 piston (movable body), 560a annular groove

Claims (16)

A valve timing adjusting device for adjusting a valve timing of a valve that opens and closes a camshaft by torque transmission from a crankshaft in an internal combustion engine,
A housing that forms a fluid chamber isolated from the outside;
A magnetorheological fluid enclosed in the fluid chamber and having a viscosity that changes when a magnetic field is applied;
Viscosity control means for variably controlling the viscosity of the magnetorheological fluid by applying a magnetic field to the magnetorheological fluid in the fluid chamber;
A brake rotating body that is rotatably supported by the housing and is in contact with the magnetorheological fluid in the fluid chamber, to which a brake torque according to the viscosity of the magnetorheological fluid is input;
A phase adjustment mechanism that is linked to the brake rotator and adjusts the relative phase between the crankshaft and the camshaft in accordance with the brake torque input to the brake rotator;
A movable body that is supported by the casing or the brake rotating body so as to be movable and exposed to the fluid chamber, and that moves according to an increase or decrease of the internal pressure of the fluid chamber, thereby increasing or decreasing the volume of the fluid chamber;
A valve timing adjusting device comprising:   The brake rotating body has a rotation shaft that penetrates the housing in and out and is connected to the phase adjustment mechanism outside the housing, and the housing includes a seal portion that seals between the rotation shaft and the rotation shaft. The valve timing adjusting device according to claim 1, comprising:   The valve timing adjusting device according to claim 1, wherein the magnetorheological fluid is partially filled in the fluid chamber.   The casing or the brake rotator that supports the movable body forms an outside air chamber through which air outside the casing flows in and out, and the movable body is between the internal pressure of the outside air chamber and the internal pressure of the fluid chamber. The valve timing adjusting device according to any one of claims 1 to 3, wherein the valve timing adjusting device moves according to a differential pressure.   The valve timing adjusting device according to claim 4, wherein the movable body is an elastically deformable diaphragm that isolates the outside air chamber and the fluid chamber, and deforms according to the differential pressure. The housing is
A fluid chamber partition member that partitions the fluid chamber together with the diaphragm;
An outside air chamber partition member that supports the diaphragm sandwiched between the fluid chamber partition member and partitions the outside air chamber between the diaphragm and the diaphragm on the opposite side of the fluid chamber;
The valve timing adjusting device according to claim 5, comprising:   The outside air chamber partitioning member has a bottomed cylindrical shape with a bottom wall facing the diaphragm across the outside air chamber, and restricts deformation movement of the diaphragm by contacting the diaphragm with the bottom wall. The valve timing adjusting device according to claim 6.   The outside air chamber partitioning member has a bottomed cylindrical shape with a bottom wall facing the diaphragm across the outside air chamber, and has a vent hole that allows air outside the housing to flow into and out of the outside air chamber. The valve timing adjusting device according to claim 6 or 7, wherein the valve timing adjusting device is formed on an outer peripheral edge portion of the wall portion.   9. A motion suppressing member that suppresses the movement of the movable body toward the brake rotating body is provided between the brake rotating body and the movable body. The valve timing adjusting device according to item. Between the brake rotator and the diaphragm, a motion suppressing member that suppresses the movement of the diaphragm toward the brake rotator is provided.
The valve timing adjusting device according to any one of claims 5 to 8, wherein the motion suppressing member is disposed so as to overlap at least a central portion of the diaphragm.   A communication path is formed around the motion suppressing member or the motion suppressing member to communicate the diaphragm side of the fluid chamber sandwiching the motion suppressing member with the brake rotating body side of the fluid chamber. The valve timing adjusting device according to claim 10.   The valve timing adjustment device according to any one of claims 6 to 8, wherein the outside air chamber partition member is a member having a higher thermal conductivity than the fluid chamber partition member.   The valve timing adjustment device according to any one of claims 6 to 8, wherein the outside air chamber partition member includes a fin that radiates heat of the outside air chamber to the outside.   The valve timing adjusting device according to claim 4, wherein the movable body is a piston that can reciprocate between the outside air chamber and the fluid chamber, and reciprocates according to the differential pressure.   The brake rotating body has a rotation shaft that penetrates the housing inward and outward and is linked to the phase adjustment mechanism outside the housing, and the rotation shaft extends the piston along a penetration direction in the housing. 15. The valve timing adjusting device according to claim 14, wherein a cylinder hole that slidably supports and defines the outside air chamber and the fluid chamber is formed on both sides sandwiching the piston.   The valve timing adjusting device according to claim 15, further comprising a seal member that seals between the piston and the cylinder hole.

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