JP2013092233A - Electromagnetic engagement device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electromagnetic engagement device configured to improve energy efficiency by reducing electromagnetic force for setting an engagement/disengagement state.SOLUTION: The electromagnetic engagement device includes: a torque cam mechanism 4 for generating thrust force according to a torque difference between a pair of cam members 15, 16; and an electromagnetic actuator 3 for generating magnetic attraction force to attract an armature 7 toward a yoke 5. The electromagnetic actuator 3 causes the yoke 5 to attract the cam member 16 as an armature 9, thereby increasing the thrust force of the torque cam mechanism 4 to integrate the cam members 15, 16. The armature 7 comprises a first armature 8 arranged to face the yoke 5 and the second armature 9 also serving as the cam member 16. The magnetic path cross-sectional area of a first magnetic circuit C1 formed by the first armature 8 is smaller than the magnetic path cross-sectional area of a second magnetic circuit C2 formed by the second armature 9.

Description

  The present invention relates to an electromagnetic engagement device that performs an engagement / release operation using an electromagnetic attraction force by an electromagnetic force and a thrust generated according to a torque difference between a pair of engagement members.

  2. Description of the Related Art Conventionally, in a power transmission system of a vehicle, an engaging device such as a clutch for connecting / disconnecting a power transmission path and a brake for restricting rotation of a rotating member by engaging / disengaging operations is used. There are various types of the engaging device, and for example, engaging devices such as a meshing type, a friction type, a fluid type, and an electromagnetic type are known. Among them, the electromagnetic engagement device is a device that interrupts power by using an electromagnetic force generated by supplying electric power. The electromagnetic engagement device includes a crimping type, a meshing type, and a gap type using iron powder as a medium depending on a structure for transmitting torque.

  As an example of the electromagnetic engagement device as described above, Patent Document 1 includes a first braking spring that includes an outer armature and an inner armature that are armatures that are magnetically attracted by electromagnetic force, and presses the outer armature. An invention relating to a non-excitation actuating electromagnetic brake provided with a second braking spring for pressing an inner armature is described. In Patent Document 1, when the magnetic attraction force of the magnetic flux is gradually increased by making the spring force of the first brake spring smaller than the spring force of the second brake spring, the outer armature is first separated from the disk, When the inner armature is separated from the disk and the magnetic attractive force of the magnetic flux is gradually reduced in the brake release state, the outer armature is first frictionally engaged with the disk, and then the inner armature is frictionally engaged with the disk 10. Is described.

  In Patent Document 2, a stator provided with an exciting coil, an armature attracted to the stator, a rotating plate connected to a rotating shaft, a braking plate that holds the rotating plate between the armature, The invention relates to an electromagnetic coupling / braking device having a pressing spring for applying a pressing force to an armature, dividing the armature into two layers and laminating a buffer member between the laminated armatures. Further, Patent Document 2 describes a configuration in which the compression spring constant of a buffer member disposed between two layers of armatures is smaller than the spring constant of a pressure spring that applies a pressing force to the armature.

Japanese Utility Model Publication No. 5-62747 JP 11-51089 A

  In the configuration described in Patent Document 1 above, two armatures, an outer armature and an inner armature, are provided, and a brake spring (return spring) is attached to each armature, and each armature has an electromagnetic force. Is magnetically attracted. Therefore, in the configuration described in Patent Document 1, the electromagnetic force for releasing the electromagnetic brake needs to be greater than or equal to the elastic force of the return spring. Therefore, there is a possibility that the electric power consumed for releasing the clutch may increase, and there is still room for improvement in terms of improving the energy efficiency of the engagement device.

  The present invention has been made by paying attention to the above technical problem, and can reduce the electromagnetic force required to set the engaged state or the released state, thereby improving the energy efficiency. Is intended to provide.

  In order to achieve the above object, the invention of claim 1 has a pair of cam members arranged so as to be opposed to each other in the rotation axis direction and relatively rotatable, and according to a torque difference between the cam members. A torque cam mechanism that generates thrust in the direction of the rotational axis and an armature that is arranged to be movable in the direction of the rotational axis by energizing an electromagnetic coil installed in the yoke to generate a magnetic attractive force. An electromagnetic actuator that attracts the electromagnetic wave toward the yoke, and the electromagnetic actuator causes the one of the cam members to be attracted to the yoke as the armature, and the torque difference is increased by the frictional force generated at that time, thereby increasing the thrust. In the electromagnetic engagement device for increasing the engagement force for integrating the cam members, the armature is attached to the yoke. A first armature that is disposed in the direction and is directly attracted to the yoke by the magnetic attraction force, and the first armature is integrally rotated about the rotation axis and is relatively movable in the rotation axis direction. And a second armature that is attracted to the yoke via the first armature by the magnetic attraction force and also serves as the one cam member, and is disposed between the first armature and the second armature A first spring that attracts and contacts the first armature to the second armature, and is installed between the second armature and the yoke to press the second armature and separate it from the yoke. A second spring having a larger elastic force than the first spring, and the first armor When the second armature is attracted to the yoke via the first armature, the magnetic path cross-sectional area of the first magnetic circuit formed in the first armature when the solder is attracted to the yoke The second armature is configured to be smaller than the magnetic path cross-sectional area of the second magnetic circuit formed in the second armature.

  In the electromagnetic engagement device of the present invention, the first armature is attracted to the yoke by energizing the electromagnetic actuator to generate an electromagnetic attractive force that exceeds the elastic force of only the first return spring. That is, by applying a relatively small current to the electromagnetic actuator, it is possible to set an engagement state in which only the first armature is attracted to the yoke. Then, the second armature is attracted to the yoke together with the first armature by increasing the current to be applied to the electromagnetic actuator from that state and generating an electromagnetic attractive force exceeding the elastic force of the second return spring. That is, by applying a relatively large current to the electromagnetic actuator, it is possible to set an engagement state in which the first armature and the second armature are attracted to the yoke. By causing the second armature to be attracted to the yoke via the first armature, the torque difference between the cam members of the torque cam mechanism is increased by the frictional force generated on each attracting surface at that time, and the torque difference depends on the torque difference. The thrust generated by the torque cam mechanism increases. Then, when the thrust generated by the torque cam mechanism increases, the engaging force of each cam member increases, and these cam members are integrated. That is, the electromagnetic engagement device is brought into an engaged state.

  Therefore, according to the electromagnetic engagement device of the present invention, the initial stage of engagement can be performed by applying a low current. Then, after the second armature is attracted to the yoke and the cam members of the torque cam mechanism are integrated, the engagement state of the electromagnetic engagement device can be maintained by the mechanical engagement force of the torque cam mechanism. That is, while the torque difference between the cam members is sufficiently large, the engagement state of the electromagnetic engagement device can be realized only by the mechanical engagement force of the torque cam mechanism. Therefore, power consumption for operating and engaging the electromagnetic engagement device can be reduced.

  Furthermore, in the electromagnetic engagement device of the present invention, the magnetic path cross-sectional area of the first magnetic circuit formed in the first armature when the first armature is attracted to the yoke is such that the second armature passes through the first armature. When attracted to the yoke, the magnetic path cross-sectional area of the second magnetic circuit formed in the second armature becomes smaller. Therefore, the residual magnetism of the first armature when energization to the electromagnetic engagement device is stopped is also reduced. Therefore, the releasing operation of the electromagnetic engagement device can be easily performed. Further, since the residual magnetism is reduced as described above, the return spring for realizing the released state of the electromagnetic engagement device can be made to have a smaller elastic force. Power consumption for realizing the engaged state can be further reduced. As a result, the energy efficiency can be improved while securing the torque capacity of the electromagnetic engagement device.

It is sectional drawing which showed typically the structural example of the electromagnetic engagement apparatus which concerns on this invention, and the open state of the electromagnetic engagement apparatus. It is sectional drawing which showed typically the structural example of the electromagnetic engagement apparatus which concerns on this invention, and the 1st engagement state of the electromagnetic engagement apparatus. It is sectional drawing which showed typically the example of a structure of the electromagnetic engagement apparatus concerning this invention, and the 2nd engagement state of the electromagnetic engagement apparatus. It is sectional drawing which shows the state which looked at the cam surface in the cam mechanism from radial direction. It is a schematic diagram for demonstrating the relationship between the electric current at the time of controlling the electromagnetic engagement apparatus which concerns on this invention, and torque capacity. It is a schematic diagram which shows an example of the hybrid drive device carrying the electromagnetic engagement apparatus which concerns on this invention. It is a schematic diagram which shows the other example of the hybrid drive device carrying the electromagnetic engagement apparatus which concerns on this invention. It is a schematic diagram which shows the other example of the hybrid drive device carrying the electromagnetic engagement apparatus which concerns on this invention.

  Next, the configuration of the present invention will be described with reference to the drawings. An electromagnetic engagement device 1 shown in FIG. 1 generates a magnetic attraction force by an electromagnetic force, and operates between an electromagnetic actuator 3 that operates in the rotation axis direction of the rotation shaft 2 (left and right direction in FIG. 1) and a pair of cam members. And a torque cam mechanism 4 that generates thrust in the direction of the rotation axis when a relative torque difference occurs.

  The electromagnetic actuator 3 is an annular member as a whole, and is fitted into a yoke 5 formed in a U shape whose peripheral section is open in the rotational axis direction, and a U-shaped cross section of the yoke 5. The magnetic coil 6 that generates magnetic flux when energized and the yoke 5 are opposed to the opening-side surface of the yoke 5 and are movable in the direction of the rotation axis on the rotation shaft 2 and are relatively rotated with respect to the rotation shaft 2. It is comprised from the armature 7 arrange | positioned possible.

  The yoke 5 is fixed to a fixing member such as a casing (not shown), for example, and is formed of a material having magnetic properties of a ferromagnetic material and strength and durability against impact and friction. Further, on the surface of the yoke 5 facing the armature 7, when the electromagnet composed of the yoke 5 and the electromagnetic coil 6 attracts the armature 7 by its electromagnetic force, it is in contact with the armature 7 and electromagnetically joined. 5a is formed.

  The armature 7 faces the joint surface 5a of the yoke 5 as described above, and is in direct contact with the joint surface 5a of the yoke 5 when attracted by the electromagnetic force of the electromagnet composed of the yoke 5 and the electromagnetic coil 6. 1 armature 8 and the surface opposite to the yoke 5 of the first armature 8 are opposed to the opposite surface in the rotational axis direction, and rotate integrally with the first armature 8 around the rotational axis of the rotational shaft 2; And it is comprised from two members with the 2nd armature 9 which fits the 1st armature 8 so that a movement to a rotation axis direction is possible.

  The first armature 8 is formed of a material having magnetic properties of a ferromagnetic material and strength and durability against impact and friction. The first armature 8 is a ring-shaped member having a hollow center portion, and an inner peripheral portion thereof is formed as a spline hole 8s. Further, when the first armature 8 is attracted to the electromagnet composed of the yoke 5 and the electromagnetic coil 6 on the surface facing the yoke 5 of the first armature 8, that is, the surface facing the joint surface 5a, the yoke 5 A joint surface 8a is formed that contacts the friction surface 5a and electromagnetically joins. Further, a joint surface 8b that contacts the second armature 9 is formed on the surface opposite to the joint surface 8a of the first armature 8 in the rotation axis direction.

  Similar to the first armature 8, the second armature 9 is formed of a material having magnetic properties of a ferromagnetic material and strength and durability against impact and friction. The second armature 9 is an annular member in which a boss portion 9a having a through-hole through which the rotation shaft 2 can be inserted is formed at the center portion, and the outer peripheral portion of the boss portion 9a is the first armature 8. It is formed as a spline shaft 9s that fits in the spline hole 8s. Further, when the second armature 9 is attracted to the surface facing the first armature 8 of the second armature 9, that is, the surface facing the joint surface 8 b, when the second armature 9 is attracted by the electromagnet composed of the yoke 5 and the electromagnetic coil 6. A joint surface 9b is formed that contacts the friction surface 8b of one armature 8 and electromagnetically joins.

  The first armature 8 and the second armature 9 are spline-fitted. Therefore, the first armature 8 is configured to rotate integrally with the second armature 9 and to be slidable on the outer periphery of the boss portion 9a of the second armature 9 in the rotation axis direction. A movable cam portion 16 that constitutes the torque cam mechanism 4 together with a fixed cam portion 15 and a cam ball 17 to be described later is formed on a surface opposite to the surface of the second armature 9 facing the first armature 8 in the rotational axis direction. Yes.

  Between the first armature 8 and the second armature 9, the first return spring 10 that attracts the first armature 8 toward the second armature 9 in the direction of the rotation axis and makes the first armature 8 abut against the second armature 9. Is installed. That is, one end of the first return spring 10 is fixed to the first armature 8 and the other end is fixed to the second armature 9.

  The first return spring 10 is composed of, for example, a tension coil spring, and the first armature 8 is in a normal state where an external force in the axial direction does not act on the first armature 8 (that is, in a non-energized state where no magnetic attractive force acts). 8 is brought into contact with the second armature 9. In other words, the first armature 8 is separated from the yoke 5. That is, an air gap having a predetermined interval is set between the joint surface 5 a of the yoke 5 and the joint surface 7 a of the armature 7. Therefore, the first armature 8 is subjected to an external force in the rotational axis direction that is larger than the elastic force of the first return spring 10, specifically, a magnetic attraction force of an electromagnet composed of a yoke 5 and an electromagnetic coil 6 as described later. Thus, the second armature 9 is configured to slide on the outer periphery of the boss portion 9 a in the rotation axis direction and be attracted to the yoke 5.

  The first armature 8 abuts against the second armature 9 on at least one of the surface facing the second armature 9 of the first armature 8 and the surface facing the first armature 8 of the second armature 9. In this state, a recess for accommodating the first return spring 10 is formed between the first armature 8 and the second armature 9. In the example shown in FIG. 1, the first armature 8 is formed with a recess that accommodates the first return spring 10.

  Further, between the second armature 9 and the yoke 5, the second armature 9 is pressed in a direction away from the yoke 5 in the direction of the rotation axis, and the second armature 9 is pressed against the fixed cam portion 15 via a cam ball 17 described later. A second return spring 11 is attached. That is, one end portion of the second return spring 11 is fixed to the tip surface of the boss portion 9 a of the second armature 9, and the other end portion is formed on one surface of the boss portion 5 b formed at the central portion of the yoke 5. It is fixed via a thrust bearing 12. Note that the movement of the boss portion 5b in the rotation axis direction is restricted by the snap ring 14 fixed to the rotation shaft 2 via the thrust bearing 13 on the other surface opposite to the rotation axis direction. .

  The second return spring 11 is composed of, for example, a compression coil spring, and is normal when no external force in the axial direction other than the reaction force from the cam ball 17 is applied to the second armature 9 (that is, when no current is applied when no magnetic attractive force is applied). ), The second armature 9 is separated from the yoke 5. Therefore, the second armature 9 is subjected to an external force in the direction of the rotational axis that is larger than the elastic force of the second return spring 11, more specifically, the magnetic attractive force of the electromagnet composed of the yoke 5 and the electromagnetic coil 6 as described later. Thus, the outer periphery of the rotary shaft 2 is slid in the direction of the rotary axis and is attracted to the yoke 5.

  The elastic force of each of the return springs 10 and 11 is set so that the elastic force of the second return spring 11 is larger than the elastic force of the first return spring 10. Therefore, a relatively small magnetic attractive force that is larger than the elastic force of the first return spring 10 and smaller than the elastic force of the second return spring 11 acts, so that the first armature 8 first moves the yoke 5. Sucked into. Then, a relatively large magnetic attractive force that is greater than the elastic force of the second return spring 11 acts, so that the second armature 9 is applied to the yoke 5 together with the first armature 8 that has been previously attracted to the yoke 5. It comes to be sucked.

  As described above, the first armature 8 is made of a magnetic material. Therefore, when the first armature 8 is attracted to the yoke 5 with a relatively small magnetic attraction force as described above, the magnetic circuit C1 is between the yoke 5 and the first armature 8 as shown in FIG. It is formed. Further, the second armature 9 is also formed of a magnetic material, and when the second armature 9 is attracted to the yoke 5 by the action of the magnetic attraction force, the second armature 9 passes through the first armature 8. Abutting on the joint surface 5a of the yoke 5 and electromagnetically joined. Therefore, when the second armature 9 is attracted to the yoke 5 with a relatively large magnetic attraction force as described above, the space between the yoke 5, the first armature 8 and the second armature 9, as shown in FIG. Also, a magnetic circuit C2 is formed.

  As described above, the magnetic circuit cross-sectional area of the magnetic circuit C1 formed between the yoke 5 and the first armature 8 has a magnetic circuit C2 formed between the yoke 5, the first armature 8 and the second armature 9. The yoke 5, the first armature 8 and the second armature 9 are formed so as to be smaller than the magnetic path cross-sectional area. For example, the magnetic path cross-sectional area of the magnetic circuit C1 is changed to the magnetic path cross-sectional area of the magnetic circuit C2 by appropriately designing the shapes and dimensions of the yoke 5, the first armature 8 and the second armature 9 and the magnetic strength of the material. It can comprise so that it may become smaller. As described above, the magnetic circuit C1 has a smaller magnetic path cross-sectional area than that of the magnetic circuit C2, and the magnetic circuit C1 when the energization to the electromagnetic coil 6 is stopped and the magnetic attractive force is lost. Is less than the residual magnetism of the magnetic circuit C2. Therefore, the releasing operation between the yoke 5 and the first armature 8 in the electromagnetic actuator 3 can be easily executed.

  In addition, it is comprised so that the magnetic flux of each above magnetic circuits C1 and C2 may not pass into the fitting part in which the spline hole 8s of the 1st armature 8 and the spline shaft 9s of the 2nd armature 9 were formed. Yes. That is, the first armature 8 and the second armature 9 are configured such that the magnetic circuits C1 and C2 as described above are not formed in the fitting portions thereof. Accordingly, even when the electromagnetic coil 6 is energized to generate an electromagnetic force, the relative movement between the first armature 8 and the second armature 9 is not hindered by the electromagnetic force.

  On the other hand, the torque cam mechanism 4 is fixed to the rotary shaft 2 and rotates integrally with the rotary shaft 2. The torque cam mechanism 4 can rotate relative to the rotary shaft 2 on the rotary shaft 2 and move in the direction of the rotary axis. And the cam ball 17 which is a spherical rolling element sandwiched between the fixed cam portion 15 and the movable cam portion 16.

  The fixed cam portion 15 is a disk-shaped member and is integrally fixed to the rotating shaft 2. Alternatively, it is formed integrally with the rotating shaft 2. A cam surface 15 a that holds the cam ball 17 is formed on the surface of the fixed cam portion 15 that faces the movable cam portion 16. Moreover, the movable cam part 16 is formed in the surface on the opposite side to the opposing surface with respect to the 1st armature 8 of the above-mentioned 2nd armature 9 in a rotating shaft direction. That is, the second armature 9 and the movable cam portion 16 are formed by an integral member. A cam surface 16a that holds the cam ball 17 together with the cam surface 15a is formed on the surface of the movable cam portion 16 facing the fixed cam portion 15, that is, the surface facing the cam surface 15a.

  As shown in FIG. 4, each of the cam surfaces 15a and 16a formed on the fixed cam portion 15 and the movable cam portion 16 has two cam surfaces inclined at a cam angle θ so that the cross section is V-shaped when viewed from the radial direction. It is composed of surfaces. And the torque cam mechanism 4 is comprised by arrange | positioning the fixed cam part 15 and the movable cam part 16 so that the cam ball 17 may be hold | maintained so that rolling between the cam surface 15a and the cam surface 16a is possible.

  As described above, the torque cam mechanism 4 includes the fixed cam portion 15 to which torque is input from the rotary shaft 2, the movable cam portion 16 integrated with the second armature 9, and the cam ball 17. This is a mechanism for engaging the movable cam portion 15 and the fixed cam portion 16 by generating an axial force corresponding to the torque difference between the movable cam portion 16 and the movable cam portion 16. The basic configuration / principle of the torque cam mechanism 4 is well known as described in, for example, Japanese Patent No. 4126986, Japanese Patent Application Laid-Open No. 2010-215079, and the like. .

  Next, the engagement operation and the release operation of the electromagnetic engagement device 1 of the present invention will be described. In a state where the electromagnetic coil 6 of the electromagnetic actuator 3 is not energized, the elastic force of the first return spring 10 that biases the first armature 8 against the second armature 9 and abuts the second armature 9, and the fixed cam portion. The armature 7, that is, the first armature 8 and the second armature 9 are separated from the yoke 5 by the elastic force of the second return spring 11 biased toward the 15 side. In this released state, as shown in FIG. 1, the armature 7 and the yoke 5 are not in contact with each other, and the joint surface 8b of the first armature 8 and the joint surface 9b of the second armature 9 are in contact with each other. In addition, the movable cam portion 16 and the fixed cam portion 15 formed in the second armature 9 are in contact with each other via the cam ball 17.

  When an electric current is passed through the electromagnetic coil 6 in the electromagnetic engagement device 1 in the released state as described above, the electromagnetic coil 6 generates a magnetic flux, and accordingly, the magnetic attraction force acting on the first armature 8 from the yoke 5 causes the first. The armature 8 is sucked into the yoke 5. At this time, since the first armature 8 is urged toward the second armature 9 by the elastic force of the first return spring 10, the magnetic attraction force generated according to the current supplied to the electromagnetic coil 6 counteracts it. When the elastic force of the first return spring 10 is overcome, the first armature 8 moves to the yoke 5 side in the rotation axis direction.

  The first armature 8 that has been attracted by the magnetic attraction force larger than the elastic force of the first return spring 10 and has moved to the yoke 5 side has its joining surface 8a abutting against the joining surface 5a of the yoke 5, The first armature 8 and the yoke 5 are frictionally engaged by the frictional force between the joint surface 8a and the joint surface 5a while being electromagnetically joined. In this engaged state, as shown in FIG. 2, the first armature 8 and the yoke 5 are electromagnetically joined and frictionally engaged, while the second armature 9 and the yoke 5 are still engaged. It is in a state that does not match. This engaged state is defined as a first engaged state.

  The first armature 8 in the first engagement state is frictionally engaged with the yoke 5 by the magnetic attractive force of the electromagnetic actuator 3. Therefore, the first engagement state is maintained while the electromagnetic coil 6 is energized and the magnetic attractive force overcomes the elastic force of the first return spring 10. When the magnetic attractive force is less than the elastic force of the first return spring 10, the first engagement state is released and the state is shifted to the released state.

  The magnetic attractive force of the electromagnetic actuator 3 increases / decreases according to the magnitude of the current supplied to the electromagnetic coil 6. And the torque capacity of this electromagnetic engagement apparatus 1 changes according to the magnitude | size of the electric current supplied to the electromagnetic electromagnetic coil 6, as shown in FIG. Therefore, by controlling the current supplied to the electromagnetic coil 6, the engagement / release state and the torque capacity of the electromagnetic engagement device 1 can be controlled.

The torque capacity of the electromagnetic engagement device 1 in the first engagement state as described above, that is, the brake torque Tb1 when the electromagnetic engagement device 1 is a brake as shown in FIG. When the suction force is Fm, the friction coefficient of the friction engagement surfaces between the first armature 8 and the yoke 5 is μ, and the friction radius (effective diameter) of these friction engagement surfaces is r,
Tb1 = μ ・ r ・ Fm
It can be expressed by the relational expression Therefore, by increasing the current flowing through the electromagnetic coil 6, the brake torque Tb1 can be increased in proportion to the magnitude of the current.

  As described above, since the first engagement state is a state in which only the first armature 8 is attracted to the yoke 5, the electromagnetic coil 6 is in a low current state in which a relatively small current is applied. . A relatively large current larger than the current in the low current state is passed through the electromagnetic coil 6 to overcome the elastic force of the second return spring 11, that is, the magnetic attractive force by the electromagnetic actuator 3 and the cam portions 15, 16 The second armature 9 moves to the yoke 5 side by generating a resultant force with the thrust generated by the torque cam mechanism 4 according to the torque difference between them. That is, when the current energized to the electromagnetic coil 6 is further increased, the magnetic flux of the first magnetic circuit C1 is saturated, and the surplus magnetic flux is released from the first armature 8 to the outside. As a result, a magnetic attractive force that attracts the second armature 9 to the first armature 8 is generated, and when the resultant force of the magnetic attractive force and the thrust by the torque cam mechanism 4 becomes larger than the elastic force of the second return spring 11. The second armature 9 is sucked toward the yoke 5 side.

  When the second armature 9 is attracted to the yoke 5 side, the joint surface of the first armature 8 whose joint surface 9b is already magnetically joined to the yoke 5 and frictionally engaged with the second armature 9 is obtained. 8b is brought into contact with the yoke 5 via the first armature 8 in contact with the armature 8b. That is, the second armature 9 is attracted to the yoke 5 via the first armature 8. As a result, the second armature 9 and the first armature 8 are frictionally engaged by the frictional force generated between the joint surface 9b and the joint surface 8b. In this engaged state, as shown in FIG. 3, the first armature 8 and the yoke 5 are already electromagnetically joined and frictionally engaged, and further, the second armature 9 and the first armature 8 Are electromagnetically joined and frictionally engaged. That is, the yoke 5, the first armature 8 and the second armature 9 are in a state of being frictionally engaged with each other. This engaged state is referred to as a second engaged state.

  The second armature 9 in the second engagement state is frictionally engaged with the yoke 5 by the magnetic attractive force of the electromagnetic actuator 3. Therefore, the second engagement state is maintained while the electromagnetic coil 6 is energized and the magnetic attractive force overcomes the elastic force of the second return spring 11. When the magnetic attractive force is less than the elastic force of the second return spring 10, the second engagement state is released and the first engagement state is entered.

  Even in the second engagement state, the magnetic attractive force of the electromagnetic actuator 3 increases or decreases according to the magnitude of the current supplied to the electromagnetic coil 6. Accordingly, the torque capacity between the second armature 9 and the yoke 5 in the second engagement state changes according to the magnitude of the current supplied to the electromagnetic electromagnetic coil 6. Further, in this second engagement state, when the second armature 9 is attracted by the yoke 5 and the torque capacity between the yoke 5 and the armature 7 increases, the second armature 9, that is, the movable cam portion 16 and the fixed cam portion 15. Torque difference occurs between Specifically, when the second armature 9 is engaged with the yoke 5, the second armature 9 is braked, and the rotational speed thereof is reduced. As the rotation speed of the second armature 9 decreases, a rotation speed difference is generated between the movable cam portion 16 and the fixed cam portion 15, and as a result, torque is generated between the movable cam portion 16 and the fixed cam portion 15. There will be a difference.

  When a torque difference is generated between the movable cam portion 16 and the fixed cam portion 15, the torque cam mechanism 4 operates. That is, in the torque cam mechanism 4, when a torque difference occurs between the movable cam portion 16 and the fixed cam portion 15, thrust in the rotation axis direction is generated according to the torque difference. Specifically, due to a torque difference between the movable cam portion 16 and the fixed cam portion 15, the cam ball 17 rides on the cam surfaces 15 a and 16 a and presses and separates the movable cam portion 16 and the fixed cam portion 15. Torque cam reaction force is generated.

  When the torque capacity between the second armature 9 and the yoke 5 increases and the torque difference between the movable cam portion 16 and the fixed cam portion 15 increases, each cam surface 15a, 16a and cam ball 17 in the torque cam mechanism 4 The torque cam reaction force of the torque cam mechanism 4 increases due to the so-called wedge effect between the two.

  Therefore, even in the second engagement state, the torque capacity of the electromagnetic engagement device 1 changes according to the magnitude of the current supplied to the electromagnetic electromagnetic coil 6 as shown in FIG. In this case, in the second engagement state, as described above, a torque capacity that is mechanically engaged by the torque cam mechanism 4 is added, so that the engagement is performed with a larger torque capacity than in the first engagement state. Will be combined. Eventually, the electromagnetic engagement device 1 can control the engagement / release state and the torque capacity by controlling the current supplied to the electromagnetic coil 6.

The torque capacity of the electromagnetic engagement device 1 in the second engagement state as described above, that is, the brake torque Tb2, is the magnetic attraction force generated by the electromagnetic actuator 3, Fm, the torque cam reaction force in the torque cam mechanism 4 is Fc, When the friction coefficient of the friction engagement surface between the armature 8 and the yoke 5 is μ and the friction radius (effective diameter) of these friction engagement surfaces is r,
Tb2 = μ · r · (Fm + Fc)
It can be expressed by the relational expression Accordingly, even in the second engagement state, the brake torque Tb2 can be increased in proportion to the magnitude of the current by increasing the current supplied to the electromagnetic coil 6.

  Next, an example in which the electromagnetic engagement device 1 of the present invention is applied to a brake in a gear train of a hybrid drive device will be described. The configuration shown in FIG. 6 is a so-called two-motor type hybrid drive device. Briefly describing the configuration, the hybrid drive device is configured to divide the power output from the engine 40 into an output shaft 42 side and a first motor / generator 43 side by a power split mechanism 41. The engine 40 is an internal combustion mechanism such as a gasoline engine or a diesel engine, and an output element such as a crankshaft is connected to a power split mechanism 41.

  In the example shown in FIG. 6, the power split mechanism 41 is configured by a single-pinion planetary gear mechanism, and the sun gear 44 and the ring gear 45 are arranged concentrically, and the pinion gear that meshes with the sun gear 44 and the ring gear 45. Is held by the carrier 46 so that it can rotate and revolve. An output shaft 40 a of the engine 40 is connected to the carrier 46. Therefore, in this example, the carrier 46 is an input element. The first gear / generator 43 is connected to the sun gear 44. Therefore, in this example, the sun gear 44 is a reaction force element. Furthermore, the electromagnetic engagement device 1 of the present invention is connected to the sun gear 44 and the first motor / generator 43 as a brake. Accordingly, by engaging the electromagnetic engagement device 1, the rotation of the sun gear 44 and the first motor / generator 43 can be braked and fixed. A ring gear 45 is connected to the output shaft 42. Therefore, in this example, the ring gear 45 is an output element.

  A second motor / generator 47 is connected to the output shaft 42 via a transmission 48. The transmission 48 is configured by a transmission mechanism that increases or decreases the torque of the second motor / generator 47 and transmits it to the output shaft 42, and the transmission ratio may be fixed to a predetermined value. Alternatively, it may be configured to be switched to a plurality of gear ratios.

  Each of the motor generators 43 and 47 is constituted by, for example, a permanent magnet type synchronous motor. The motor generators 43 and 47 function as a motor by energizing the coil to output torque, and the rotor is forcibly rotated by an external force to generate power. It functions as a machine and is configured to generate power. Each of these motor generators 43 and 47 is electrically connected to a power storage device such as a battery via an inverter (not shown) so that the electric power generated by one motor generator can be supplied to the other motor generator. It is configured. The inverter is connected to an electronic control device (not shown) mainly composed of a microprocessor, and the electronic control device controls the rotational speed, torque, power generation amount, etc. of each motor / generator 43, 47. It is configured. The engine 40 is configured such that the intake air amount, the fuel supply amount, the ignition timing, and the like are electrically controlled, and accordingly the torque and the rotational speed are electrically controlled.

  In the so-called normal hybrid mode in which the power output from the engine 40 is divided into the first motor / generator 43 side on the output shaft 42 side, the first motor / generator 43 is caused to function as a generator, and the torque accompanying the power generation is sun gear. 44 acts as a so-called reaction torque. Along with this, a torque obtained by amplifying the engine torque is generated in the ring gear 45 as an output element. In addition, the electric power obtained by the first motor / generator 43 is transmitted to the output shaft 42 via the transmission 48 by the second motor / generator 47 functioning as a motor. That is, a part of the power output from the engine 40 is transmitted to the output shaft 42 via the power split mechanism 41, and after other power is converted into electric power, it is converted again into mechanical power and output. It is transmitted to the shaft 42.

  Further, when the engine load is gradually reduced, the rotational speed of the sun gear 44, that is, the first motor / generator 43 is reduced. This is for controlling the rotational speed of the engine 40 to a rotational speed with good fuel efficiency. Finally, when the rotation speed of the sun gear 44 is set to zero, the sun gear 44 is fixed by engaging the electromagnetic engagement device 1 instead of generating the reaction torque by the first motor / generator 43. To generate reaction torque. By doing so, it is not necessary to control the torque of the first motor / generator 43, and the energy efficiency of the hybrid drive device can be improved.

  7 and 8 show another configuration example of the hybrid drive device to which the electromagnetic engagement device 1 of the present invention is applied. The electromagnetic engagement device 1 of the present invention includes, for example, a planetary gear mechanism and a hydraulic friction engagement device such as a clutch or a brake, and controls the engagement / release state of the clutch and the brake by hydraulic pressure. Thus, the present invention can also be applied to a conventional automatic transmission for vehicles that performs shift control. That is, the electromagnetic engagement device 1 of the present invention can be used instead of the friction engagement device used in the conventional automatic transmission for vehicles.

  As described above, the electromagnetic engagement device of the present invention is not limited to the above-described embodiment, and can be used as a target in addition to being used as a brake. Further, in the above-described embodiment, the configuration example in which the yoke 5 is fixed to a fixed portion such as a casing and the braking force is applied to the rotating shaft 2 has been described. However, the yoke 5 receives the transmission torque of the rotating shaft 2 and the power transmission system. The structure which transmits a torque to the other rotation member in may be sufficient.

  As described above, according to the electromagnetic engagement device 1 according to the present invention, the initial stage of engagement for attracting the first armature 8 to the yoke 5 can be performed by applying a low current. After the second armature 9 is attracted to the yoke 5 together with the first armature 8 and the fixed cam 15 and the movable cam 16 of the torque cam mechanism 4 are integrated, the electromagnetic force is generated by the mechanical engagement force in the torque cam mechanism 4. The engaged state of the engagement device 1 can be maintained. Therefore, while the torque difference between the fixed cam 15 and the movable cam 16 is sufficiently large, the engagement state of the electromagnetic engagement device 1 can be realized only by the mechanical engagement force of the torque cam mechanism 4. That is, it is possible to configure a so-called self-locking mechanism that maintains the engaged state when there is torque input even in a non-energized state. Therefore, the power consumption for operating and engaging the electromagnetic engagement device 1 by energizing the electromagnetic coil 6 can be reduced. In terms of design, instead of the above self-locking mechanism, it is also possible to configure a so-called self-releasing mechanism that can realize a released state even when there is torque input.

  Then, when the first armature 8 is attracted to the yoke 5, the magnetic path cross-sectional area of the first magnetic circuit C <b> 1 formed in the first armature 8 is the second armature 9 to the yoke 5 via the first armature 8. When attracted, the magnetic path cross-sectional area of the second magnetic circuit C2 formed in the second armature 9 becomes smaller. Therefore, since the magnetic path cross-sectional area of the first magnetic circuit C1 is small, the residual magnetism remaining in the first armature 8 when the energization to the electromagnetic engagement device 1 is stopped is also small. Therefore, the releasing operation of the electromagnetic engagement device 1 can be easily executed.

  Moreover, since the residual magnetism of the 1st armature 8 is small as mentioned above, the 1st return spring 10 for implement | achieving the releasing state of the electromagnetic engagement apparatus 1 can be made into a thing with a smaller elastic force. Therefore, the power consumption for realizing the engagement state of the electromagnetic engagement device 1 can be further reduced.

  DESCRIPTION OF SYMBOLS 1 ... Electromagnetic engagement apparatus, 2 ... Rotary shaft, 3 ... Electromagnetic actuator, 4 ... Torque cam mechanism, 5 ... Yoke, 6 ... Electromagnetic coil, 7 ... Armature, 8 ... 1st armature, 9 ... 2nd armature, 10 ... 1st DESCRIPTION OF SYMBOLS 1 return spring, 11 ... 2nd return spring, 15 ... Fixed cam part, 16 ... Movable cam part, 17 ... Cam ball.

Claims (1)

A torque cam mechanism that has a pair of cam members arranged opposite to each other in the rotation axis direction and capable of relative rotation, and that generates a thrust in the rotation axis direction according to a torque difference between the cam members; and a yoke An electromagnetic actuator that attracts an armature arranged so as to be movable in the direction of the rotation axis by energizing an installed electromagnetic coil to generate a magnetic attractive force, the electromagnetic actuator including the cam One of the members is attracted to the yoke as the armature, and the torque difference is increased by the friction force generated at that time, thereby increasing the thrust and increasing the engagement force for integrating the cam members. In the combined device,
A first armature disposed opposite the yoke and directly attracted to the yoke by the magnetic attractive force; and the first armature is integrally rotated about the rotation axis and in the direction of the rotation axis The second armature that is fitted so as to be relatively movable and is attracted to the yoke via the first armature by the magnetic attraction force, and also serves as the one cam member,
A first spring installed between the first armature and the second armature to attract and abut the first armature to the second armature; and installed between the second armature and the yoke. A second spring that presses the second armature away from the yoke and has a larger elastic force than the first spring;
When the first armature is attracted to the yoke, the magnetic path cross-sectional area of the first magnetic circuit formed in the first armature is attracted to the yoke via the first armature. In this case, the electromagnetic engagement device is configured to be smaller than a magnetic path cross-sectional area of a second magnetic circuit formed in the second armature.

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