JP6131582B2 - Electromagnetic clutch - Google Patents

Description

  The present invention relates to an electromagnetic clutch, and more particularly, to an improvement in technology for transmitting a driving force transmitted to a driving-side rotator to a driven-side rotator via an electromagnetically operated clutch unit.

  As an electromagnetic clutch configured as described above, Patent Document 1 discloses an electromagnetic solenoid (electromagnetic coil in the literature) fitted in a driving side rotating body (in the literature, a driving pulley) and a driven side rotating body (in the literature, a pump shaft). And a clutch plate that rotates integrally therewith.

  In Patent Document 1, a clutch plate is supported on a driven side rotating body via a hub, a plate member, and the like, and a friction material is formed on a side surface of the driving side rotating body at a position facing the clutch plate. As a result, when the electromagnetic solenoid is excited, the clutch plate is attracted and pressed against the friction material to transmit the rotational force of the driving side rotating body to the driven side rotating body.

JP 2010-242623 A

  As described in Patent Document 1, an electromagnetic solenoid is a magnetic body that houses a coil in an annular yoke having a U-shaped cross section, and generates a strong magnetic flux in the yoke by energizing the coil. The magnetic flux is configured to be transmitted to the driving side rotating body.

  For example, in a water pump provided in an engine of a vehicle, it is desired to rotate an impeller that sends cooling water at a high speed. Therefore, as shown in Patent Document 1, the drive side rotating body is configured as a pulley, and in a configuration in which a belt driven by a crankshaft is wound around this pulley, the drive is performed to rotate the impeller at high speed. It is necessary to reduce the radius of the side rotating body.

  However, in order to reliably operate the electromagnetic clutch with the electromagnetic solenoid housed inside the drive-side rotating body, the solenoid portion of the electromagnetic solenoid has a predetermined cross-sectional area and a conductor having a predetermined number of turns, and a predetermined number of turns. It is necessary to use a yoke having a cross-sectional area. For this reason, the volume for accommodating the electromagnetic solenoid is determined, and it is difficult to reduce the diameter of the drive side rotor, and there is room for improvement.

  The objective of this invention exists in the point which comprises rationally the electromagnetic clutch which can make the outer diameter of a drive side rotary body small.

A feature of the present invention is an electromagnetic clutch used in a water pump,
A drive-side rotator is formed by forming a cylindrical outer peripheral wall centered on the rotation axis, an inner peripheral wall on the inner side thereof, and a side wall connected thereto with a magnetic body. In the drive-side rotator, An electromagnetic solenoid fitted in an annular space at a position surrounded by the outer peripheral wall, the inner peripheral wall and the side wall; A clutch unit that transmits the rotational force of the driving side rotating body to the driven side rotating body by being attracted to the side wall; and a solenoid unit that generates a magnetic flux when energized; A yoke made of a magnetic material so as to transmit the magnetic flux to the drive side rotator, and the yoke is in an attitude perpendicular to the rotation axis. A main yoke portion disposed at a position where the main shaft portion is closed, and the main yoke portion includes at least one of an inner peripheral side close to the rotating shaft core and an outer peripheral side spaced from the rotating shaft core as a reference. An extending yoke portion extending in a direction away from the annular space and having a cylindrical shape centering on the rotational axis is provided, and the drive-side rotating body has an auxiliary yoke portion at a position facing the extending yoke portion. Formed of magnetic material ,
An introduction space for guiding cooling water leaked from the water pump is formed between the housing of the water pump and the yoke .

According to this feature, since the extending yoke portion extending in a direction away from the annular space is formed from at least one of the inner peripheral side and the outer peripheral side of the main yoke portion, the inner peripheral wall or the outer periphery of the driving side rotating body is formed. It is not necessary to form a yoke at a position facing the inner surface of the wall. As a specific configuration, for example, in which an extended yoke portion is formed on the outer periphery of the main yoke portion, the wall portion of the yoke that has been conventionally formed at a position facing the inner surface of the outer peripheral wall of the drive-side rotating body. It is possible to configure the yoke so as to have a cross-sectional shape from which is removed. Thereby, it becomes possible to make the inner surface of the outer peripheral wall of the driving side rotating body close to the outer peripheral surface of the coil portion by a distance corresponding to the thickness of the yoke, and the outer diameter of the driving side rotating body can be reduced.
In this configuration, a gap is formed between the extension yoke portion and the auxiliary yoke portion, but the opposing area is widened to reduce the magnetic resistance. For this reason, when the solenoid portion is energized, the magnetic flux is efficiently transmitted from the main yoke portion to the extending yoke portion, and further, the drive side rotating body is passed through the auxiliary yoke portion close to the extending yoke portion. Can communicate efficiently.
Therefore, while changing the yoke constituting the electromagnetic solenoid and the shape of a part of the drive side rotator, the drive side rotator is maintained while maintaining the ability to strongly attract the clutch unit to the drive side rotator. An electromagnetic clutch that can be reduced in diameter is constructed.

In the present invention, the yoke includes the main yoke portion, an inner yoke portion facing the inner peripheral wall, and the extending yoke portion formed with reference to the outer peripheral side of the main yoke portion ,
The housing is formed with a boss-like portion having a cylindrical shape coaxial with the rotational axis,
The introduction space communicates with a space that is partitioned outwardly in a direction along the rotation axis from the seal position of the driven side rotating body in the internal space of the boss-shaped portion, and the housing of the water pump. The main yoke portion and the extended yoke portion may be formed in a region surrounded by the main yoke portion and the extended yoke portion .

  According to this, it becomes possible to comprise a solenoid part with the form which winds a conductor with respect to an inner side yoke part. Further, when the solenoid portion is energized, the magnetic flux flowing through the inner yoke portion and the yoke body can be transmitted to the extending yoke portion. Further, since the yoke is not disposed on the outer peripheral side of the solenoid part, the inner surface of the outer peripheral wall of the drive side rotor can be disposed at a position close to the outer peripheral surface of the solenoid part by a distance corresponding to the thickness of the yoke. Thus, the outer diameter of the drive side rotating body can be reduced.

It is sectional drawing of an electromagnetic clutch. It is an expanded sectional view of the electromagnetic clutch of a transmission state. It is an expanded sectional view of the electromagnetic clutch of another embodiment (a).

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
〔overall structure〕
1 and 2 show a water pump that can be switched between power transmission and interruption by the electromagnetic clutch C of the present invention and circulates the cooling water of the engine E of the vehicle. This water pump has a driving pulley 10 as a driving side rotating body rotatable around a rotation axis X with respect to a pump housing 1 connected and fixed to an engine E of a vehicle, and a shaft 18 as a driven side rotating body. And is supported rotatably.

  The pump housing 1 is formed with an opening 1A centering on the rotation axis X, and a cylindrical boss 1B centering on the rotation axis X is formed at a position continuous with the opening. The shaft 18 (an example of a driven-side rotating body) is disposed at a position penetrating a space from the opening 1A to the boss-like portion 1B, and is rotatable to the inner peripheral portion of the boss-like portion 1B by a ball bearing type shaft bearing 2. It is supported. A mechanical seal 3 is provided between the shaft 18 and the opening 1 </ b> A, and an impeller 4 for water supply is provided at the inner end of the shaft 18.

  A drive pulley 10 (an example of a drive-side rotator) is rotatably supported on an outer peripheral surface of a boss 1B of the pump housing 1 by a ball bearing type pulley bearing 5. With this configuration, the drive pulley 10 and the shaft 18 are rotatable relative to each other about the rotation axis X.

  The driving pulley 10 includes a cylindrical outer peripheral wall 11 centering on the rotation axis X, a cylindrical inner peripheral wall 12 centering on the rotation axis inside the rotation pulley core X, and the rotation axis X connected to them. The side wall 13 in an orthogonal posture is integrally formed using a magnetic material (desirably a ferromagnetic material) such as an iron material or a nickel alloy material. In the drive pulley 10, an annular space 10 </ b> S that opens in the direction of the pump housing 1 is formed in a region surrounded by the outer peripheral wall 11, the inner peripheral wall 12, and the side wall 13, and the electromagnetic solenoid 20 of the electromagnetic clutch C is provided in the annular space 10 </ b> S. It is inserted.

  A belt winding portion 11 </ b> A for winding a V-ribbed belt type driving belt 14 is formed on the outer peripheral surface of the outer peripheral wall 11. The pulley bearing 5 is disposed in a state where the outer race is brought into contact with the surface of the inner peripheral wall 12 facing the direction of the rotation axis X. A clutch surface 13A to which the armature 33 is press-contacted is formed on the outer surface side of the side wall 13 (the outer surface opposite to the pump housing 1). The side wall 13 has a plurality of through holes 13B penetrating the clutch surface 13A in the circumferential direction. Are formed with a gap.

  The driving pulley 10 may have a structure in which a flat belt is wound, or may have a structure in which a timing belt is wound.

  In this water pump, since the drive belt 14 is wound around the output pulley provided on the crankshaft of the engine E and the drive pulley 10, the drive pulley 10 is continuously rotated when the engine E is in operation. The electromagnetic clutch C is controlled by a control device (not shown) that acquires a detection result of a temperature sensor (not shown) that detects the coolant temperature. When it is determined that the coolant temperature is low (immediately after the engine E is started), the control device maintains the electromagnetic clutch C in the disengaged state to accelerate the warm-up. When it is determined that the temperature of the engine E has exceeded the set value, the electromagnetic clutch C is set in the transmission state, and the cooling water is circulated by driving the impeller 4.

[Electromagnetic clutch]
The electromagnetic clutch C includes the electromagnetic solenoid 20 accommodated in the annular space 10S of the drive pulley 10 and the clutch unit 30 that rotates integrally with the shaft 18 as described above. The drive pulley 10 forms a magnetic circuit that causes the magnetic flux from the electromagnetic solenoid 20 to act on the armature 33 of the clutch unit 30, and this drive pulley 10 also constitutes a part of the electromagnetic clutch C.

  The electromagnetic solenoid 20 includes a solenoid portion 21 that is excited by energization (generates a magnetic flux) and a yoke made of a magnetic material such as an iron material or a nickel alloy material so that the magnetic flux from the solenoid portion 21 is transmitted to the drive pulley 10. ing. The yoke integrally forms a main yoke portion 22, an inner peripheral inner yoke portion 23, and an outer peripheral outer extending yoke portion 24. The main yoke portion 22 is disposed at a position that closes the annular space 10 </ b> S in a posture orthogonal to the rotation axis X. The inner yoke portion 23 has a cylindrical shape centering on the rotation axis X on the inner peripheral side close to the rotation axis X of the main yoke portion 22 and faces the inner peripheral surface of the inner peripheral wall 12 with a predetermined distance. Placed in position. The outer extending yoke portion 24 is a cylindrical annular space centered on the rotational axis X on the outer peripheral side of the main yoke portion 22 that is spaced outward from the inner peripheral side with reference to the rotational axis X. It arrange | positions in the form extended in the direction away from 10S.

  In this electromagnetic solenoid 20, the radius to the outer peripheral surface of the solenoid portion 21 with respect to the rotational axis X is made to coincide with the radius to the outer peripheral surface of the outer extending yoke portion 24 with reference to the rotational axis X. . The electromagnetic solenoid 20 is arranged so that the outer peripheral surface of the outer extending yoke portion 24 and the outer peripheral surface of the solenoid portion 21 are present on a common virtual circumferential surface. It is not excluded that the positional relationship between the outer peripheral surface of the extending yoke portion 24 and the outer peripheral surface of the solenoid portion 21 is slightly different in the radial direction.

  The pump housing 1 is formed with a cylindrical portion 1C having a cylindrical shape centering on the rotation axis X on the outer side of the boss-shaped portion 1B. The outer extending yoke portion 24 is formed with respect to the cylindrical portion 1C. The extended end is supported. As a result, the yoke is supported by the pump housing 1 and the position of the electromagnetic solenoid 20 is determined. In order to support the electromagnetic solenoid 20 on the pump housing 1, a configuration in which a yoke is connected to a bracket or the like fixed to the pump housing 1 may be employed.

  Further, an introduction space G surrounded by the outer peripheral side of the boss-like portion 1B, the inner peripheral side of the cylindrical portion 1C, and the main yoke portion 22 of the yoke is formed, and the introduction space G and the shaft are formed in the boss-like portion 1B. A plurality of guide holes 2H connecting the space in which 18 is arranged are formed.

  The solenoid portion 21 has a configuration in which a conducting wire is wound around the bobbin 20A, and is fixed in a positional relationship in which the inner peripheral surface of the bobbin 20A is in close contact with the inner yoke portion 23 and the side surface is in close contact with the main yoke portion 22. Has been. Although not shown in the drawings, a power cable for supplying power from the pump housing 1 to the conducting wire of the solenoid portion 21 is formed along the cylindrical portion 1C.

  Of the outer peripheral wall 11 of the drive pulley 10, the end facing the pump housing 1 is provided with the auxiliary yoke portion 15 facing the outer peripheral surface of the outer extending yoke portion 24 described above. The auxiliary yoke portion 15 is formed of a magnetic material such as an iron material or a nickel alloy material at a position and is attached to the outer peripheral wall 11 of the drive pulley 10, but may be formed integrally with the drive pulley 10.

  Further, the outer peripheral surface of the inner yoke portion 23 constituting the yoke is opposed to the inner peripheral surface of the inner peripheral wall 12 of the drive pulley 10 with a predetermined distance, and the inner peripheral surface of the outer peripheral wall 11 of the drive pulley 10 is set to the solenoid portion. It is made to oppose with respect to the outer peripheral surface of 21 at a predetermined distance. Further, as described above, the relative positional relationship is set so that the outer peripheral surface of the outer extending yoke portion 24 faces the inner peripheral surface of the auxiliary yoke portion 15 with a predetermined distance therebetween. Note that the above-mentioned predetermined distance is desirably a value that makes the magnetic resistance between the opposing elements as small as possible.

  With this configuration, a magnetic circuit is formed by the inner yoke portion 23, the main yoke portion 22, the outer extending yoke portion 24, the auxiliary yoke portion 15, and the outer peripheral wall 11, the side wall 13, and the inner peripheral wall 12 of the drive pulley 10. . In particular, in this magnetic circuit, the inner yoke portion 23 and the inner peripheral wall 12 face each other on a wide surface in a positional relationship close to each other, so that the magnetic resistance at this portion is lowered. Further, since the outer extending yoke portion 24 and the auxiliary yoke portion 15 are opposed to each other in a wide area in a positional relationship close to each other, the magnetic resistance at this portion is also lowered.

  When the solenoid portion 21 is energized, a magnetic flux F (see FIG. 2) having a high magnetic flux density is transmitted to the magnetic circuit, and the magnetic flux F leaking outward at the site of the through hole 13B of the side wall 13 is transmitted to the armature 33. And is attracted to the clutch surface 13A with a strong suction force. In addition, you may comprise so that friction coefficient may be raised by forming lining etc. in this clutch surface 13A, and abrasion may be suppressed.

[Clutch unit]
The clutch unit 30 includes a bush 31 supported on the end of the shaft 18, an annular armature 33, and a plurality of spring plates 34 that separate the armature 33 from the side wall 13 of the drive pulley 10.

  The bush 31 is fitted and connected so as to rotate integrally with the shaft 18. The armature 33 is formed of a magnetic material such as an iron material or a nickel alloy material, and the spring plate 34 is made of an elastically deformable plate material such as spring steel, and has one end connected to the flange portion 31A at the end of the bush 31. The other end is connected to the armature 33. As a result, an urging force is applied in a direction in which the armature 33 is separated from the side wall 13 of the drive pulley 10.

  With this configuration, when the solenoid portion 21 is not energized, the armature 33 is located away from the clutch surface 13A of the side wall 13 as shown in FIG. This state is the disengagement state of the electromagnetic clutch C, and the driving force from the driving pulley 10 is not transmitted to the shaft 18. Next, when the solenoid portion 21 is energized, a magnetic flux F is formed in the magnetic circuit composed of the yoke and the drive pulley 10 as shown in FIG. It leaks outward at the portion 13B and acts on the armature 33, and a strong suction force is applied to the armature 33 to attract it to the clutch surface 13A. This state is an engaged state of the electromagnetic clutch C, and the rotational force of the driving pulley 10 is transmitted from the clutch unit 30 to the shaft 18 to drive the water pump.

  When the solenoid portion 21 is energized, the magnetic flux generated by the main yoke portion 22 and the inner yoke portion 23 is transmitted through the gap between the outer extension yoke portion 24 and the auxiliary yoke portion 15. Since they are opposed to each other on a wide surface and are close to each other and have a low magnetic resistance, the magnetic flux density is not attenuated at this portion, and the electromagnetic clutch C can be kept in a good state.

  In particular, since the sectional shape of the yoke of the electromagnetic solenoid 20 is changed to a shape in which the yoke portion on the outer peripheral side is removed instead of the conventional U-shaped one, the outer diameter of the entire yoke is reduced, and the yoke thickness is reduced. The inner diameter of the outer peripheral wall of the drive-side rotator is brought closer to the outer peripheral surface of the solenoid portion 21 by a distance corresponding to the distance, thereby reducing the outer diameter of the drive-side rotator. Thereby, the outer peripheral diameter of the drive pulley 10 is reduced, and the rotational speed of the impeller 4 is increased.

  The mechanical seal 3 slightly leaks cooling water. When the cooling water leaks, the mechanical seal 3 leads from the guide hole 2H of the boss 1B to the introduction space G and enters the main yoke 22 of the electromagnetic solenoid 20 or the like. By making it contact, it can vaporize with the heat | fever which generate | occur | produces in the electromagnetic solenoid 20. FIG.

[Another embodiment]
The present invention may be configured as follows in addition to the embodiment described above.

(A) As shown in FIG. 3, the yoke of the electromagnetic solenoid 20 is configured by integrally forming a main yoke portion 22, an outer peripheral side yoke portion 25, and an inner extending yoke portion 26. The main yoke portion 22 is disposed at a position that closes the annular space 10 </ b> S in a posture orthogonal to the rotational axis X as in the embodiment. The outer periphery side yoke portion 25 is cylindrical on the outer periphery side of the main yoke portion 22 and is disposed at a position facing the inner peripheral surface of the outer peripheral wall 11 with a predetermined distance from the rotation axis X. The inner extension yoke portion 26 is formed in a cylindrical shape centered on the rotation axis X on the inner peripheral side of the rotation axis X in the main yoke portion 22 and extending in a direction away from the annular space 10S. ing.

  Further, of the inner peripheral wall 12 of the drive pulley 10 as the drive side rotating body, the end facing the pump housing 1 is an iron material or nickel alloy material at a position facing the inner peripheral surface of the inner extending yoke portion 26 described above. An auxiliary yoke portion 15 formed of a magnetic material such as a magnetic material is provided. The auxiliary yoke portion 15 is connected to the drive pulley 10, but can be formed integrally with a member constituting the drive pulley 10.

  In this other embodiment (a), the radius to the inner peripheral surface of the inner extending yoke portion 26 with reference to the rotational axis X and the radius to the inner peripheral surface of the solenoid portion 21 with reference to the rotational axis X The relative positional relationship is set so that and match. With this configuration, the outer diameter of the entire yoke is reduced, and the inner surface of the outer peripheral wall 11 of the driving side rotating body is disposed close to the outer peripheral surface of the solenoid portion 21 by a distance corresponding to the thickness of the yoke, and the outer diameter of the driving side rotating body is set. It is possible to make it smaller. Thereby, the outer peripheral diameter of the drive pulley 10 is reduced, and the rotation speed of the water pump is increased.

(B) With respect to the yoke of the electromagnetic solenoid 20 with respect to the main yoke portion 22 and the outer peripheral side of the main yoke portion 22, the outer extending yoke portion 24 shown in the embodiment and the outer peripheral side of the main yoke portion 22. Thus, the inner extending yoke portion 26 shown in another embodiment (a) is integrally formed. With this configuration, the outer diameter of the entire yoke is further reduced, and the outer diameter of the drive pulley 10 serving as the drive-side rotating body is reduced, so that the rotation speed of the water pump can be increased.

  INDUSTRIAL APPLICABILITY The present invention can be used for an electromagnetic clutch that transmits a driving force of a driving side rotating body to a driven side rotating body by energizing an electromagnetic solenoid.

1 Housing (pump housing)
10 Drive side rotating body (drive pulley)
10S annular space 11 outer peripheral wall 12 inner peripheral wall 13 side wall 15 auxiliary yoke part 18 driven side rotating body (shaft)
20 Electromagnetic solenoid 21 Solenoid part 22 Main yoke part 23 Inner yoke part 24 Extension yoke part (outer extension yoke part)
26 Extension yoke (inner extension yoke)
30 Clutch unit F Magnetic flux X Rotating shaft core

Claims (2)

An electromagnetic clutch used for a water pump,
A drive-side rotator is formed by forming a cylindrical outer peripheral wall centered on the rotation axis, an inner peripheral wall on the inner side thereof, and a side wall connected thereto with a magnetic body. In the drive-side rotator, Comprising an electromagnetic solenoid fitted into an annular space at a position surrounded by an outer peripheral wall, the inner peripheral wall and the side wall;
A clutch which is supported by a driven side rotating body arranged coaxially with the rotating shaft core and transmits the rotational force of the driving side rotating body to the driven side rotating body by being attracted to the side wall when the electromagnetic solenoid is energized. With a unit,
The electromagnetic solenoid includes a solenoid part that generates a magnetic flux when energized, and a yoke made of a magnetic material so as to transmit the magnetic flux from the solenoid part to the driving side rotating body,
The yoke includes a main yoke portion disposed at a position that closes the annular space in a posture orthogonal to the rotation axis; an inner peripheral side of the main yoke portion that is close to the rotation axis; An extending yoke portion extending in a direction away from the annular space on the basis of at least one of an outer peripheral side separated from the rotating shaft core and having a cylindrical shape around the rotating shaft core;
The drive-side rotating body has an auxiliary yoke portion formed of a magnetic material at a position facing the extending yoke portion .
An electromagnetic clutch in which an introduction space for guiding cooling water leaked from the water pump is formed between a housing of the water pump and the yoke . The yoke includes the main yoke portion, an inner yoke portion facing the inner peripheral wall, and the extending yoke portion formed with reference to the outer peripheral side of the main yoke portion ,
The housing is formed with a boss-like portion having a cylindrical shape coaxial with the rotational axis,
The introduction space communicates with a space that is partitioned outwardly in a direction along the rotation axis from the seal position of the driven side rotating body in the internal space of the boss-shaped portion, and the housing of the water pump. The electromagnetic clutch according to claim 1, wherein the electromagnetic clutch is formed in a region surrounded by the main yoke portion and the extending yoke portion .

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