JP2008025408A - Valve timing adjustment device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a valve timing adjustment device suppressing ununiformness of an intermediate phase accomplished at the starting of an engine. <P>SOLUTION: The valve timing adjustment device has a torque generation means for generating control torque in a setting direction; and an input rotation body input with the control torque from the torque generation means. A phase variation mechanism for varying a relative phase between a crank shaft and a cam shaft by rotating the input rotation body according to torque balance in the input rotation body; and an urging means for varying urging torque T<SB>u</SB>in a step form when the relative phase of the cam shaft relative to the crank shaft becomes an intermediate phase P<SB>m</SB>between the latest angle phase P<SB>r</SB>and the most advancement angle phase P<SB>a</SB>are provided. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a valve timing adjusting device for an internal combustion engine that adjusts the valve timing of at least one of an intake valve and an exhaust valve whose camshaft opens and closes by torque transmission from a crankshaft.

  Conventionally, the relative phase between the crankshaft and the camshaft that determines the valve timing when the internal combustion engine is started (hereinafter referred to as “engine start”), in order to ensure both startability of the internal combustion engine and improvement in fuel consumption and output. 2. Description of the Related Art There is known a valve timing adjusting device that can hold (hereinafter referred to as “engine phase”) in an intermediate phase between the most retarded angle phase and the most advanced angle phase.

For example, in the apparatus disclosed in Patent Document 1, an intermediate phase is realized by generating a brake torque that balances the biasing torque generated by the restoring force of the elastic member when the engine is started.
JP 2005-146993 A

  However, in the apparatus disclosed in Patent Document 1, the biasing torque due to the restoring force of the elastic member is linearly changed with respect to the engine phase throughout the engine phase. Therefore, for example, when the brake device changes its characteristics and the brake torque varies, the intermediate phase realized by the balance between the brake torque and the biasing torque also varies as shown in FIG. This is also a phenomenon that occurs in the same manner, for example, when the elastic member changes its characteristics and the urging torque varies. For this reason, the apparatus disclosed in Patent Document 1 may not obtain a desired intermediate phase when the engine is started.

  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 suppresses variations in the intermediate phase that is realized when the engine is started.

  According to the first aspect of the present invention, the urging torque for urging the input rotator in the direction opposite to the control torque in the setting direction input from the torque generating means to the input rotator of the phase change mechanism has an engine phase of When the intermediate phase is reached, it is changed stepwise by the biasing means. As a result, a step of the urging torque is generated in the intermediate phase. Even if the control torque and the urging torque vary, the balance point that balances the control torque in the urging torque is shifted within the width of the step, for example. be able to. That is, since the variation in the applied torque to the input rotator can be absorbed by the step of the urging torque, the torque balance in the input rotator is held at the intermediate phase and the variation in the intermediate phase is suppressed when the engine is started. be able to. The “change in a step shape” may be a change that generates a step of the energizing torque on both sides of the intermediate phase, and the change may be realized substantially only in the intermediate phase. The change may be realized in a phase region sandwiching the intermediate phase (for example, a region slightly widened with respect to the intermediate phase).

  According to the second aspect of the present invention, the biasing means sets the width of the step of the biasing torque that changes stepwise in the intermediate phase to be larger than the variation width of the control torque. Can be absorbed reliably. Therefore, the effect of suppressing the variation in the intermediate phase is promoted.

  During operation of the internal combustion engine including when the engine is started (hereinafter referred to as “engine operation”), the camshaft fluctuation torque is normally transmitted to the phase change mechanism. Therefore, in order to adjust the engine phase with high accuracy, it is effective to consider not only the balance between the braking torque and the urging torque but also the balance between these torques and the average torque of the fluctuation torque. In general, the average torque of the variable torque tends to vary depending on various factors such as the friction generated in the cam of the camshaft, the type of oil that lubricates the internal combustion engine, and the environmental temperature.

  Therefore, according to the third aspect of the present invention, the sum of the average torque of the varying torque that is transmitted from the camshaft to the phase change mechanism and acts on the input rotator when the engine is started and the biasing torque is defined as the balance target torque. To do. Under this definition, the control torque that the torque generating means acts on the input rotor when starting the engine is larger than the upper limit of variation of the balance target torque on the most retarded angle phase side and the most advanced angle phase side relative to the intermediate phase. In addition, it is set smaller than the variation lower limit value of the balance target torque on the other side of the most retarded angle phase and the most advanced angle phase with respect to the intermediate phase. According to this setting, even if variations occur in the average torque and the energizing torque of the fluctuation torque, the point that balances the control torque in the balance target torque that is the sum of these torques is the step of the energizing torque that changes stepwise. Can fit within the width of the step. Therefore, when the engine is started, the average torque of the control torque, the urging torque, and the variable torque acting on the input rotating body can be balanced in the intermediate phase, so that the accuracy of realizing the intermediate phase is improved.

  According to the fourth aspect of the present invention, the biasing means is configured to adjust the biasing torque in the intermediate phase so that the difference between the variation upper limit value and the variation lower limit value of the balance target torque is larger than the variation width of the control torque. Set the width of the step. According to this setting, the point that balances with the control torque in the balance target torque can be surely contained within the width of the step of the urging torque. Therefore, the effect of improving the accuracy of realizing the intermediate phase is promoted.

  According to the fifth aspect of the present invention, the fluctuation torque from the camshaft acts on the input rotating body in the reverse direction of the control torque on average. That is, since the average torque of the variable torque is a torque in the direction opposite to the control torque, even if an abnormality occurs in the biasing means, the input rotator is balanced by the balance between the control torque in the input rotator and the average torque. It is possible to adjust the engine phase by rotating.

  According to the sixth aspect of the present invention, the urging means raises the urging torque in the intermediate phase with respect to one value of the most retarded angle phase side and the most advanced angle phase side with respect to the intermediate phase and the intermediate phase. Relative to the other value on the most retarded angle phase side and the most advanced angle phase side. According to this, since the engine phase when the urging torque changes in a step shape can be suppressed from spreading to both sides of the intermediate phase, as described above, the intermediate phase realized by the torque balance of the input rotating body is as follows. It becomes more difficult to vary. It should be noted that “one value on the most retarded angle phase side and the most advanced angle phase side relative to the intermediate phase”, which is the starting point of the rising as the energizing torque, may be “0” or greater than “0”. It may be a value.

  According to the seventh aspect of the present invention, the elastic member of the urging means is attached by engaging the phase change mechanism at one of the intermediate phase and the most retarded angle phase side and the most advanced angle phase side of the intermediate phase. A restoring force that provides at least a part of the force torque is generated. On the other hand, the elastic member on the other side of the most retarded angle phase and the most advanced angle phase with respect to the intermediate phase regulates the contribution of the restoring force to the urging torque by separating from the phase change mechanism. According to such an elastic member, the elastic member rises sharply with respect to the value on the side of the most retarded angle phase side and the most advanced angle phase side of the intermediate phase from which the elastic member leaves the phase change mechanism, and the elastic member is in phase. The biasing torque that falls sharply with respect to the value on the side engaged with the change mechanism can be provided with a simple configuration.

  According to the eighth aspect of the present invention, the elastic member is engaged with the input rotating body at one of the intermediate phase and the most retarded angle phase side and the most advanced angle phase side from the intermediate phase, and the most retarded angle from the intermediate phase. The other side of the phase side and the most advanced angle phase side leaves the input rotator. As a result, when the elastic member is engaged with the input rotator, the restoring force of the elastic member acts directly on the input rotator to give the urging torque, so that the desired urging torque is generated. It is possible to reduce the necessary restoring force as much as possible. Therefore, it is possible to reduce the size of the elastic member by using an elastic member having a low spring constant, and thus to reduce the size of the apparatus.

  According to the ninth aspect of the present invention, since the elastic member is a winding spring, the size necessary for securing the restoring force in the predetermined rotation direction as the urging torque is made possible in the axial direction and the axial direction as much as possible. Can be made smaller. The “winding spring” means a spring having a shape in which a spring material is wound with a constant curvature or a variable curvature, and may be, for example, a torsion coil spring or a spiral spring. The same applies to the “winding spring” according to the twelfth aspect of the present invention.

  According to the invention described in claim 10, the urging means has the second elastic member in addition to the first elastic member as the elastic member. Here, the second elastic member generates a restoring force that applies at least a part of the urging torque by engaging with the phase change mechanism in the entire region between the most retarded angle phase and the most advanced angle phase. Therefore, on the side where the first elastic member is engaged with the phase change mechanism among the most retarded angle phase side and the most advanced angle phase side with respect to the intermediate phase, it is energized by the sum of the restoring forces of the first and second elastic members. Torque can be applied, and biasing torque can be applied by the restoring force of only the first elastic member on the side where the first elastic member separates from the phase change mechanism. Accordingly, it becomes possible to apply an urging torque larger than “0” to the input rotating body on both sides of the intermediate phase, so that the range of the adjustable engine phase is widened by the balance between the urging torque and the control torque. The adjustment accuracy can be increased.

  According to the eleventh aspect of the invention, the urging means changes the engine phase from the intermediate phase side to the side of the most retarded angle phase side and the most advanced angle phase side where the first elastic member engages the phase change mechanism. The more the energizing torque is increased linearly with respect to the engine phase. Further, the energizing torque decreases linearly with respect to the engine phase as the engine phase changes from the intermediate phase side to the most retarded phase side and the most advanced phase side from which the first elastic member leaves the phase change mechanism. Let Such linear decrease and increase of the biasing torque can be accurately expressed by elastic deformation of the member that contributes to generation of the biasing torque among the first and second elastic members. In addition, the control torque that balances with the energizing torque has a linear relationship with the engine phase in a range where the energizing torque linearly decreases or increases, so that the control torque for realizing the desired engine phase Can be easily and accurately determined.

  According to the twelfth aspect of the present invention, since the second elastic member is a winding spring, the size necessary for securing the restoring force in the predetermined rotation direction as the biasing torque can be set in the axial direction and the axial direction. It can be made as small as possible.

  According to the thirteenth aspect of the present invention, since the elastic member generates a restoring force that gives all of the urging torque, the number of parts required for generating the urging torque can be reduced.

  According to the invention described in claim 14, since the electric brake device of the torque generating means generates a brake torque as a control torque, the torque balance of the input rotating body, and consequently the valve timing according to the engine phase is controlled by the electric control of the brake torque. It can be adjusted with high accuracy.

  According to the fifteenth aspect of the present invention, the electric motor of the torque generating means generates two rotational torques including the control torque. Therefore, the valve according to the torque balance of the input rotating body and thus the engine phase is controlled by the electric control of the rotational torque. The timing can be adjusted with high accuracy.

  Hereinafter, a plurality of embodiments of the present invention will be described with reference to the drawings. In addition, the overlapping description is abbreviate | omitted by attaching | subjecting the same code | symbol to the corresponding component in each embodiment.

(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 is provided in a transmission system that transmits engine torque from a crankshaft (not shown) of the internal combustion engine to the camshaft 2. The valve timing adjusting device 1 is a combination of the torque generating system 4 and the phase changing mechanism 8 and adjusts the valve timing of the intake valve of the internal combustion engine by changing the engine phase. In this embodiment, the engine phase is defined as the relative phase of the camshaft 2 with respect to the crankshaft.

First, the torque generation system 4 will be described. The torque generation system 4 includes an electric brake device 5 and an energization control circuit 6. The electric brake device 5 is a so-called electromagnetic brake that generates a brake torque applied to the rotary shaft 7 as a control torque _Tc by energization. The energization control circuit 6 includes a microcomputer or the like, and is disposed outside and / or inside the electric brake device 5 and is electrically connected to the electric brake device 5. The energization control circuit 6 controls energization to the electric brake device 5 during engine operation. In response to this controlled energization, the electric brake device 5 holds or increases or decreases the control torque _Tc applied to the rotating shaft 7.

  Next, the phase change mechanism 8 will be described. The phase change mechanism 8 includes a driving side rotating body 10, a driven side rotating body 20, elastic members 30 and 32, a planetary carrier 40, and a planetary gear 50.

  As shown in FIGS. 1 and 2, the drive-side rotating body 10 is formed by screwing a cylindrical gear member 12 and a sprocket 13 together. An inner peripheral portion of the gear member 12 forms a drive side internal gear portion 14. The sprocket 13 is provided with a plurality of teeth 16 projecting outward. The sprocket 13 is connected to the crankshaft by winding an annular timing chain between the teeth 16 and the plurality of teeth of the crankshaft. Therefore, when the engine torque output from the crankshaft is input to the sprocket 13 through the timing chain, the drive-side rotator 10 rotates while maintaining a relative phase with respect to the crankshaft in conjunction with the crankshaft. At this time, the rotation direction of the drive-side rotator 10 is the clockwise direction in FIG.

  The driven side rotating body 20 has a cylindrical shape and is concentrically disposed on the inner peripheral side of the sprocket 13. The outer peripheral portion of the driven side rotating body 20 forms a concentric driven side outer gear portion 22 on the inner peripheral side of the drive side inner gear portion 14. The inner peripheral portion of the driven side rotating body 20 forms a connecting portion 24 that is coaxially fixed to the camshaft 2 and is connected to the camshaft 2. With this connection, the driven-side rotator 20 can rotate while maintaining a relative phase with respect to the camshaft 2 in conjunction with the camshaft 2 and can rotate relative to the drive-side rotator 10. . As shown in FIG. 2, the relative rotation direction in which the driven-side rotator 20 advances with respect to the drive-side rotator 10 is the direction X, and the driven-side rotator 20 is delayed with respect to the drive-side rotator 10. The angular relative rotation direction is direction Y.

  As shown in FIGS. 1 and 3, the first elastic member 30 is formed of a spiral spring as a “winding spring”, and is arranged in a form in which the spring material extends with a variable curvature on the outer peripheral side of the planet carrier 40. One end 34 of the first elastic member 30 is always engaged with the gear member 12 via the pin member 18. As shown in FIG. 4, the other end portion 35 of the first elastic member 30 engages with one of the stopper portion 19 of the gear member 12 and a stopper portion 46 of the planetary carrier 40 described later, and disengages from the other.

  As shown in FIG. 1, the second elastic member 32 includes a torsion coil spring as a “winding spring”, and is concentrically disposed on the inner peripheral side of the sprocket 13. One end 38 of the second elastic member 32 is always engaged with the sprocket 13, and the other end 39 of the second elastic member 32 is always engaged with the driven-side rotating body 20.

As shown in FIGS. 1 and 3, the planet carrier 40 has a cylindrical shape, and an input portion 41 to which a control torque T _c is input from the rotating shaft 7 of the electric brake device 5 is formed by an inner peripheral portion. A plurality of groove portions 42 are opened in the input portion 41 concentric with the rotating bodies 10, 20 and the rotation shaft 7, and the planetary carrier 40 is connected to the rotation shaft 7 through a joint 43 fitted to the groove portions 42. It is connected. By this connection, the planetary carrier 40 can rotate integrally with the rotating shaft 7 and can rotate relative to the drive-side rotating body 10.

  As shown in FIG. 1, the planetary carrier 40 is formed with an eccentric portion 44 that is eccentric with respect to the gear portions 14 and 22 by an outer peripheral portion on one end side. The eccentric portion 44 is fitted on the inner peripheral side of the center hole portion 51 of the planetary gear 50 via a bearing 45. By this fitting, the planetary gear 50 can realize a planetary motion that revolves around the eccentric center of the eccentric portion 44 and revolves in the rotation direction of the eccentric portion 44. As shown in FIGS. 1 and 3, the planetary carrier 40 forms a stopper portion 46 by a through hole 47 that penetrates the end portion on the opposite side to the eccentric portion 44 in the radial direction.

  As shown in FIGS. 1 and 2, 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 planetary gear 50 meshes with the gear portions 14 and 22 at different locations. Specifically, the outer peripheral portion of the planetary gear 50 forms a drive-side external gear portion 52 that meshes with the drive-side internal gear portion 14 on the eccentric side. The number of teeth of the drive side external gear portion 52 is set to be smaller than the number of teeth of the drive side internal gear portion 14. In the planetary gear 50, an inner peripheral portion adjacent to the center hole portion 51 forms a driven side internal gear portion 54 that meshes with the driven side external gear portion 22 on the side opposite to the eccentric side. The number of teeth of the driven side internal gear portion 54 is set to be smaller than the number of teeth of the driving side external gear portion 52 and larger than the number of teeth of the driven side external gear portion 22.

With the above configuration, the differential gear portion 60 is formed that transmits the planetary carrier 40 by decelerating and transmitting the rotation of the planetary carrier 40 to the camshaft 2 by the planetary gear 50 meshing with the gear portions 14 and 22 performing planetary motion. According to the phase change mechanism 8 provided with the differential gear portion 60, when the planetary carrier 40 does not rotate relative to the drive-side rotator 10 by holding the control torque _{Tc or} the like, the planetary gear 50 is rotated by the gear portions 14 and 22. Rotating integrally with the rotating bodies 10 and 20 while maintaining the meshing position. Therefore, the engine phase does not change and the valve timing is kept constant accordingly.

On the other hand, when the planetary carrier 40 rotates relative to the drive side rotor 10 in the direction Y due to an increase in the control torque _{Tc or} the like, the planetary gear 50 makes a planetary motion while changing the meshing position with the gear portions 14 and 22. As a result, the driven-side rotator 20 rotates relative to the drive-side rotator 10 in the direction X. Therefore, the engine phase changes toward the advance side, and the valve timing advances according to the change.

On the other hand, when the planetary carrier 40 rotates relative to the drive side rotor 10 in the direction X due to a decrease in the control torque _{Tc or} the like, the planetary gear 50 changes the meshing position with the gear portions 14 and 22 and performs planetary motion. As a result, the driven-side rotator 20 rotates relative to the drive-side rotator 10 in the direction Y. Accordingly, the engine phase changes to the retard side, and the valve timing is retarded accordingly.

  Next, the characteristic part of 1st embodiment is demonstrated.

(Control torque _Tc )
The control torque _Tc generated by the electric brake device 5 applies a brake to the planet carrier 40 that rotates during engine operation. Therefore, the control torque _Tc is a torque in a direction Y (see FIG. 3) in which the engine phase is advanced among the relative rotation directions of the planetary carrier 40 with respect to the drive-side rotator 10.

(Average torque T _{ave of} fluctuating torque)
During engine operation, the fluctuation torque generated by the driving reaction force of the intake valve is transmitted from the cam shaft 2 to the phase change mechanism 8, and the fluctuation torque acts on the planet carrier 40 through the differential gear portion 60. As shown in FIG. 5, this fluctuating torque fluctuates between a positive torque for retarding the engine phase and a negative torque for advancing the engine phase. Here, in particular, the fluctuation torque of the present embodiment has a tendency that the maximum value T ₊ of the positive torque tends to be larger than the minimum value T _{− of the} negative torque, and hence the average torque (hereinafter referred to as “average fluctuation torque”). .) T _ave is biased to the positive side. Therefore, the average fluctuation torque T _ave acting on the planet carrier 40 is a torque in the direction X (see FIG. 3) that retards the engine phase in the relative rotation direction of the planet carrier 40 with respect to the drive side rotor 10.

(Biasing torque T _u )
As shown in FIG. 4, the stopper portions 19 and 46 with which the first elastic member 30 engages are switched according to the engine phase. Specifically, the intermediate phase (hereinafter, referred to as "start phase".) To allow engine starting when P _m and than to achieve the most advanced angle phase P _a side of the engine phase, as shown in FIG. 4 (b), ( As shown in c), the end portion 35 of the first elastic member 30 engages with the stopper portion 46 and separates from the stopper portion 19. Therefore, in the starting phase P _m and the phase range of the most advanced angle phase P _a side thereof, by applying a restoring force to the first elastic member 30 is generated by the elastic deformation of the winding direction to the planet carrier 40, a planetary The carrier 40 is energized. Here, in the present embodiment, the direction in which the planetary carrier 40 is urged is set to the direction X that retards the engine phase in the relative rotation direction of the planetary carrier 40 with respect to the drive-side rotator 10, and therefore by urging. The planetary carrier 40 is given a torque in the direction X. On the other hand, when realizing the most retarded angle phase P _r side of the engine phase than the starting phase P _m, as shown in FIG. 4 (a), the end portion 35 of the first elastic member 30 is engaged with the stopper portion 19 In addition, it is detached from the stopper portion 46. Therefore, in the phase range of the most retarded angle phase P _r side of the starting phase P _m, biasing the planet carrier 40 by restoring force of the first elastic member 30 is restricted. In the following, a phase range of the most retarded angle phase P _r side of the starting phase P _m "first phase range R _1", the starting phase P _m and the phase range of the most advanced angle phase P _a side thereof This is referred to as “second phase range R ₂ ”.

  As shown in FIG. 1, the second elastic member 32 that is always engaged with the driven-side rotator 20 causes the driven-side rotator 20 to act on the driven-side rotator 20 with a restoring force generated by elastic deformation in the winding direction. 20 is energized. In this embodiment, the direction in which the driven-side rotator 20 is urged is set to the direction Y (see FIG. 3) that retards the engine phase in the relative rotation direction of the driven-side rotator 20 with respect to the drive-side rotator 10. Yes. Therefore, the torque acting on the planet carrier 40 from the energized driven rotor 20 through the differential gear section 60 is the direction X for retarding the engine phase in the relative rotation direction of the planet carrier 40 with respect to the drive rotor 10. (See FIG. 3).

From the above, the first and second elastic members 30, 32 in the second phase range R ₂ urges the planet carrier 40 together, the urging torque T _u is the planet carrier by their both restoring force of the elastic members 30, 32 40 directions X will be given. Here, the restoring force of each of the elastic members 30 and 32 increases linearly with respect to the change of the engine phase toward the advance angle side. Therefore, in the second phase range R ₂ shown in FIG. There more changes from the starting phase P _m side to the most advanced angle phase P _a side, the urging torque T _u is linearly increased. On the other hand, in the first phase range R ₁ where the biasing of the planetary carrier 40 by the first elastic member 30 is restricted and only the second elastic member 32 biases the planetary carrier 40, the biasing by only the restoring force of the elastic member 32 is applied. The force torque _Tu is applied in the direction X of the planet carrier 40. Here, the restoring force of the second elastic member 32 is adapted to linearly decrease with respect to the change in the retard side of the engine phase, hence the first phase range R ₁ shown in FIG. 6, the engine phase is starting phase more changes from P _m side to the most retarded angle phase P _r side, the urging torque T _u is linearly decreased.

Generating form each phase range R ₁ of the thus biased torque T _u, are different in R _2, and because the first elastic member 30 is present initial load, starting phase as shown in FIG. 6 P _m , The biasing torque T _u changes in a step shape, and a step ΔT of the torque T _u is generated. In particular, in this embodiment, the number of elastic members that contribute to the generation of the urging torque T _u increases or decreases with the start phase P _m as a boundary, so that the urging torque T _u is slightly retarded at the start phase P _m . rising sharply to the value of the phase P _r side, it falls sharply relative to and slightly most advanced angle phase P _a-side value. As a result, the engine phase when the urging torque T _u changes stepwise is unlikely to spread to both sides of the starting phase P _m , so that the step ΔT of the urging torque T _u can be accurately formed in the starting phase P _m. it can. In the present embodiment, the restoring force of the first elastic member 30 that creates the step ΔT due to the initial load directly acts on the planet carrier 40 so that the differential gear portion 60 is not subjected to the deceleration action. Therefore, the restoring force necessary to obtain the step ΔT having the desired width can be made as small as possible. Therefore, for example, the apparatus 1 can be downsized by using a small spring with a low spring constant as the first elastic member 30.

(Torque balance)
Engine to the planet carrier 40 during operation, and it, as well as the control torque T _c direction Y acts average variable torque T _ave and the urging torque T _u of the reverse X, the drive side of the planet carrier 40 by the balance of their torque The relative rotational position with respect to the rotating body 10 and the engine phase are determined. Particularly in this embodiment Therefore, in order to hold the engine phase to the starting phase P _m at the time of engine startup of the time of engine operation (e.g., when cranking up the internal combustion engine complete explosion), the average variation of the control torque T _c The torque T _ave and the biasing torque _Tu are appropriately balanced. In the following description, the sum of the average variable torque T _ave and the urging torque T _u to balance and control torque T _c will be referred to "balance target torque T _b '.

More specifically, as to the step ΔT appearing in balance target torque T _b as shown in FIG. 7 due to the step change of the urging torque T _u, generates a control torque T _c falling within its width, electric The energization of the brake device 5 is controlled by the energization control circuit 6 in an open loop.

Preferably, the energization of the electric brake device 5 is controlled in an open loop so as to generate a control torque _Tc that satisfies both the following conditions (1) and (2) within the width of the step ΔT as shown in FIG. Further, in this case, it is more preferable to set the width of the step ΔT in advance by adjusting the load of the elastic members 30 and 32 so that the following condition (3) is satisfied as shown in FIG. In FIG. 7, the solid line graph represents the lower limit of the variation of the balance target torque T _b, the broken line graph indicates the upper limit of the variation of the balance target torque T _b.
(1) It is larger than the upper limit value T _bmax of the variation of the balance target torque T _b in the first phase range R ₁ .
(2) It is smaller than the lower limit value T _bmin of the variation of the balance target torque T _b in the second phase range R ₂ .
(3) The difference between the upper limit value T _bmax of the variation of the balance target torque T _b in the first phase range R ₁ and the lower limit value T _bmin of the variation of the balance target torque T _b in the second phase range R ₂ is the control torque larger than the width? T _c of the variation of T _c.

Here, the variation of the balance target torque T _b in the first phase range R ₁ is a variation of the average variable torque T _ave to be expected at the time of engine startup, the restoring force of the second elastic member 32 to provide a biasing torque T _u And the expected variation. Variations in the balance target torque T _b in the second phase range R ₂ is a variation of the average variable torque T _ave to be expected at the time of engine starting, per restoring force of the elastic members 30, 32 to provide a biasing torque T _u prediction It is calculated in consideration of the variation that is made. The variation in the control torque _Tc is determined in consideration of, for example, a variation in the energization amount predicted immediately after the start of energization of the electric brake device 5 due to engine start.

As described above, according to the first embodiment, within the width of the step ΔT that is pinpointed at the starting phase P _m by the generation of the characteristic biasing torque _Tu that changes stepwise, the balance target torque T _b A point that balances with the control torque _Tc can be accommodated. Therefore, even if the acting torques T _c , T _b (T _ave , T _u ) on the planetary carrier 40 vary, the variation can be absorbed by the step ΔT to realize a desired starting phase P _m . In particular, the control torque T _c is the condition (1), when to meet (2) the average variable torque T _ave and biasing torque T _u constituting the balance target torque T _b is within the expected range even it varies arbitrarily, since the independent control torque T _c is with the variation can be accommodated within the width of the step [Delta] T, the variation of the starting phase P _m can be suppressed. Further, when the condition (3) is satisfied, even if the control torque T _c varies arbitrarily within the predicted range, the control torque falls within the width of the step ΔT larger than the variation width δT _c. securely videos T _c, it is possible to sufficiently suppress the variation in the start-up phase P _m.

According to the first embodiment, in each of the first and second phase ranges R ₁ and R ₂ , the urging torque _Tu that is larger than “0” and linearly changes with respect to the engine phase is generated. Can do. Therefore, after the engine is started, the control torque T _c to be balanced with the balance target torque T _b including the urging torque _Tu is easily set in both the phase ranges R ₁ and R ₂ , that is, in the entire engine phase. Therefore, it is possible to adjust the engine phase that changes in accordance with the torque balance point, and thus the valve timing, with high accuracy.

  In the first embodiment described above, the torque generation system 4 including the electric brake device 5 and the energization control circuit 6 corresponds to “torque generation means”, the planetary carrier 40 corresponds to “input rotator”, and The first and second elastic members 30 and 32 together constitute “biasing means”.

(Second embodiment)
As shown in FIG. 8, the second embodiment of the present invention is a modification of the first embodiment, and the second elastic member 32 is reduced. Therefore, in the second phase range R _2, by one of the elastic member 30 is engaged with the planet carrier 40, all of the urging torque T _u direction X to linearly increase with respect to the engine phase, as shown in FIG. 9 The restoring force of the elastic member 30 is given. On the other hand, in the first phase range R _1, the elastic member 30 is not engaged with the planet carrier 40, as shown in FIG. 9, bias torque T _u with given to the planet carrier 40 becomes "0".

As described above, also in the second embodiment, the generation form of the urging torque _Tu is different in each of the phase ranges R ₁ and R ₂ , and the initial load is present on the elastic member 30, as shown in FIG. in, so that the urging torque T _u produce a step ΔT is obtained by abrupt step change in the startup phase P _m. Therefore, when the engine is started, the biasing torque T _u applied to the planetary carrier _40, it is possible to balance the average variable torque T _ave and control torque T _c by the same method as the first embodiment, the start-up phase P _m It can be obtained with high accuracy.

In the second embodiment, the average fluctuation torque T _ave and the control torque T _c are balanced in order to obtain the engine phase within the first phase range R ₁ after the engine is started. Therefore, the second embodiment is effective when, for example, the average fluctuation torque T _ave is large.

  In the second embodiment described above, the elastic member 30 corresponds to “biasing means”.

(Third embodiment)
As shown in FIG. 10, the third embodiment of the present invention is a modification of the first embodiment, and an electric motor 100 is provided instead of the electric brake device 5. The electric motor 100 is, for example, a brushless motor that generates rotational torques in two directions X and Y applied to the rotating shaft 7 by energization. In the present embodiment, the torque in the direction Y in which the engine phase is advanced among the torque generated by the electric motor 100 is applied to the planetary carrier 40 as the control torque _Tc .

In such a third embodiment, at the time of engine start, the control torque T _c of the average variable torque T _ave and the urging torque T _u and balance to direction Y generated by the electric motor 100. At this time, by appropriately by the same method as the first embodiment the torque balance in the planet carrier 40, can be obtained starting phase P _m with high accuracy.

  In the case of the third embodiment, the valve timing is maintained by maintaining the rotational torque of the electric motor 100, etc., and the valve timing is advanced by increasing the rotational torque in the direction Y, etc. The valve timing is retarded due to an increase in the angle.

  In the third embodiment described above, the torque generation system 4 including the electric motor 100 and the energization control circuit 6 corresponds to “torque generation means”.

(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. it can.

For example, for the step change of the urging torque T _u, in addition to generating the first intermediate phase P _m between the most retarded angle phase P _r and the most advanced angle phase P _a as described above also, a plurality of intermediate phase You may make it produce in. Thereby, intermediate phase stopping at a plurality of locations can be realized without requiring complicated control. When the urging torque _Tu is changed stepwise in a plurality of intermediate phases, it engages with the components of the phase change mechanism 8 within a predetermined phase range, for example, according to the elastic member 30, and outside the range. A countermeasure such as adding an elastic member to be detached from the element is taken.

The width of the step ΔT biasing torque T _u, it is preferable to set as the condition (3) is satisfied, the torque T _c, T _ave, comparable to the sum of the variation width of T _u or You may set so that it may become larger. Here, in the case where it is approximately equal to the sum of the variation widths, for example, it is possible to reduce the size of the device 1 using a small elastic member 30 with a low spring constant, and when the sum is larger than the sum of the variation widths. In addition, robustness due to variation absorption is increased. In addition to the above, the width of the step ΔT, the torque T _c, T _ave, may be set smaller than the sum of the variation width of T _u, in this case, most of the variation is absorbed by the step ΔT Thus, it is possible to prevent the engine phase from greatly deviating from the starting phase.

  As the elastic member 30, besides the spiral spring described above, a torsion coil spring or other types of springs may be employed. The elastic member 30 may generate a restoring force that changes nonlinearly with respect to the amount of elastic deformation according to the engine phase. Furthermore, the end portion 35 of the elastic member 30 may be switched between engagement and disengagement between the driving side rotating body 10 and the driven side rotating body 20.

  As the elastic member 32, a spiral spring or other types of springs may be employed in addition to the torsion coil spring described above. The elastic member 33 may generate a restoring force that changes nonlinearly with respect to the amount of elastic deformation according to the engine phase. Furthermore, the end 39 of the elastic member 32 may be always engaged with the planet carrier 40 by changing the arrangement position of the elastic member 32 or the like.

As the “torque generating means”, for example, a hydraulic motor or the like may be employed in addition to the above-described electric brake device 5 and the electric motor 100. Further, the direction of the control torque _Tc generated by such “torque generation means” may be set in the direction opposite to the above-mentioned direction Y. In this case, the direction of the biasing torque _Tu is also set in the direction opposite to the direction X described above.

As the phase change mechanism 8, mechanisms having various configurations can be adopted as long as the effects of the present invention can be obtained, in addition to the above-described differential gear unit 60. Further, the average torque T _ave of the fluctuating torque transmitted to the phase change mechanism 8 may be applied to the planet carrier 40 in the direction opposite to the direction X described above.

  In addition to the above-described device for adjusting the valve timing of the intake valve, the present invention is applied to a device for adjusting the valve timing of the exhaust valve and a device for adjusting the valve timing of both the intake valve and the exhaust valve. Can do.

It is a cross-sectional schematic diagram which shows the valve timing adjustment apparatus by 1st embodiment. It is the II-II sectional view taken on the line of FIG. It is the III-III sectional view taken on the line of FIG. It is sectional drawing for demonstrating the action | operation of the valve timing adjustment apparatus of FIG. It is a schematic diagram for demonstrating a fluctuation | variation torque. It is a schematic diagram which shows the characteristic of the valve timing adjustment apparatus of FIG. It is a schematic diagram which shows the characteristic of the valve timing adjustment apparatus of FIG. It is a cross-sectional schematic diagram which shows the valve timing adjustment apparatus by 2nd embodiment. It is a schematic diagram which shows the characteristic of the valve timing adjustment apparatus of FIG. It is a cross-sectional schematic diagram which shows the valve timing adjustment apparatus by 3rd embodiment. It is a schematic diagram which shows the characteristic of the conventional valve timing adjustment apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Valve timing adjustment apparatus, 2 Cam shaft, 4 Torque generation system (torque generation means), 5 Electric brake device (torque generation means), 6 Current supply control circuit (torque generation means), 7 Rotating shaft, 8 Phase change mechanism, 10 Drive side rotating body, 14 Drive side internal gear part, 18 Pin member, 19, 46 Stopper part, 20 Driven side rotary body, 22 Driven side external gear part, 30 First elastic member / elastic member (biasing means / winding spring) ), 32 Second elastic member (biasing means / winding spring), 40 planet carrier (input rotating body), 41 input portion, 47 through hole, 50 planetary gear, 52 driving side external gear portion, 54 driven side internal gear portion , 60 differential gear unit, 100 electric motor (torque generating means), _{P m} start phase, _{R 1} first phase range, _{R 2} the second phase _{range, T ave} average variable torque (average torque), _{T b-balanced} torque , T _bmax upper limit (the variation upper _{limit), T bmin} lower limit (the variation lower limit value), _{T c} control torque, urging torque with _{T u,} [Delta] T step,? T _c width (variation width)

Claims (15)

A valve timing adjustment device for an internal combustion engine that adjusts the valve timing of at least one of an intake valve and an exhaust valve whose camshaft opens and closes by torque transmission from a crankshaft,
Torque generating means for generating a control torque in the setting direction;
A relative phase between the crankshaft and the camshaft by rotating the input rotator in accordance with a torque balance in the input rotator; A phase change mechanism that changes
An urging means for generating an urging torque that urges the input rotating body in a direction opposite to the control torque, wherein the relative phase of the camshaft with respect to the crankshaft is a most retarded angle phase and a most advanced angle phase. Energizing means for changing the energizing torque stepwise when the intermediate phase is between,
A valve timing adjusting device comprising:   2. The valve timing adjusting device according to claim 1, wherein the biasing unit sets a width of a step of the biasing torque that changes stepwise in the intermediate phase to be larger than a variation width of the control torque. . When the sum of the average torque of the variable torque transmitted from the camshaft to the phase change mechanism and acting on the input rotating body at the start of the internal combustion engine and the biasing torque is defined as a balance target torque,
The torque generating means applies the control torque to be applied to the input rotating body at the start of the internal combustion engine to the balance target torque on one of the most retarded angle phase side and the most advanced angle phase side with respect to the intermediate phase. The variation upper limit value is set to be smaller than a variation lower limit value of the balance target torque on the other side of the most retarded angle phase side and the most advanced angle phase side with respect to the intermediate phase. 3. The valve timing adjusting device according to 1 or 2.   The biasing means sets the width of the step of the biasing torque that changes stepwise in the intermediate phase so that the difference between the variation upper limit value and the variation lower limit value is larger than the variation width of the control torque. The valve timing adjusting device according to claim 3, wherein   5. The valve timing adjusting device according to claim 3, wherein the fluctuation torque acts on the input rotating body in a direction opposite to the control torque on average.   The biasing means raises the biasing torque in the intermediate phase with respect to one value of the most retarded angle phase side and the most advanced angle phase side relative to the intermediate phase, and more than the intermediate phase. The valve timing adjusting device according to any one of claims 1 to 5, wherein the valve timing adjustment device falls with respect to the other value on the most retarded angle phase side and the most advanced angle phase side.   The urging means engages with the phase change mechanism on one of the intermediate phase and the most retarded angle phase side and the most advanced angle phase side of the intermediate phase, thereby at least part of the urging torque. And restoring the force to the urging torque by separating from the phase change mechanism on the other side of the most retarded phase and the most advanced phase with respect to the intermediate phase. The valve timing adjusting device according to claim 6, further comprising an elastic member that regulates the valve timing.   The elastic member is engaged with the input rotator on one of the intermediate phase and the most retarded phase side and the most advanced angle phase side from the intermediate phase, and the most retarded phase side from the intermediate phase. The valve timing adjusting device according to claim 7, wherein the valve timing adjusting device is separated from the input rotating body on the other side of the most advanced angle phase side.   The valve timing adjusting device according to claim 7 or 8, wherein the elastic member is a spiral spring.   The urging means engages with the first elastic member as the elastic member and the phase change mechanism in the entire region between the most retarded angle phase and the most advanced angle phase, thereby at least one of the urging torques. The valve timing adjusting device according to any one of claims 7 to 9, further comprising a second elastic member that generates a restoring force for providing a portion.   As the relative phase changes from the intermediate phase side to the side where the first elastic member engages the phase change mechanism among the most retarded phase side and the most advanced angle phase side from the intermediate phase side, The biasing torque is linearly increased with respect to the engine phase, and the first elastic member is separated from the phase change mechanism from the intermediate phase side to the most retarded phase side and the most advanced angle phase side. The valve timing adjusting device according to claim 10, wherein the bias torque is linearly decreased with respect to the engine phase as the relative phase changes.   The valve timing adjusting device according to claim 10 or 11, wherein the second elastic member is a spiral spring.   The valve timing adjusting device according to any one of claims 7 to 9, wherein the elastic member generates a restoring force that gives all of the biasing torque.   The valve timing adjusting device according to any one of claims 1 to 13, wherein the torque generating means includes an electric brake device that generates a brake torque as the control torque.   The valve timing adjusting device according to any one of claims 1 to 13, wherein the torque generating means includes an electric motor that generates a rotational torque in two directions including the control torque.

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