JP2012072823A - Free wheel hub - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably maintain the state of four wheel drive and thereby improve power transmission reliability in a free wheel hub configured so that the state of two wheel drive is maintained by applying a magnetic attraction force by a magnet.SOLUTION: The outer periphery of a diaphragm 13 partitioning the interior of a hub housing 6 into a two wheel drive side negative pressure chamber 21 and a four wheel drive side negative pressure chamber 22 is held from both sides by a sleeve 8 and a diaphragm cover 14. The center part of the diaphragm 13 is held from both sides by an outer reinforcing plate 15 and an inner reinforcing plate 16. The outer reinforcing plate 15 and the inner reinforcing plate 16 are connected to each other by caulking a rivet 17 inserted through the center part. The state of the two wheel drive is maintained by the action in which a magnet 23 mounted on the inner surface of the diaphragm cover 14 attracts the outer reinforcing plate 15. The state of the four wheel drive is maintained by the action in which a magnet 32 fixed on the end surface of a front axle 1 attracts the inner reinforcing plate 16.

Description

  The present invention relates to a freewheel hub for a four-wheel drive vehicle.

  The FR-based four-wheel drive vehicle has a transfer that distributes power from the engine and the transmission to the front propeller shaft and the rear propeller shaft, and by the transfer, two-wheel drive (2WD) and four-wheel drive (4WD) To switch to.

  Here, when the driven side wheel and the driven side axle are in a coupled state during traveling by two-wheel drive, the driven side axle is rotated from the driven side wheel, so that the traveling resistance increases and energy is wasted. Will be consumed.

  In order to eliminate such inconvenience, in the four-wheel drive vehicle described in Patent Document 1, a free wheel hub is provided between the driven wheel and the driven axle, and the transfer is switched to the two-wheel drive. The driven wheel is disconnected from the driven axle and the driven wheel is set free to reduce wasteful running resistance. On the other hand, when the transfer is switched to four-wheel drive, the driven wheel and the driven axle are locked. Thus, the power from the engine is transmitted to the driven wheel.

  In order to switch between two-wheel drive and four-wheel drive, in the free wheel hub described in Patent Document 1, the wheel hub of the driven wheel is provided rotatably on the same axis as the driven axle. A two-wheel drive side negative pressure chamber and a four-wheel drive side negative pressure chamber are formed by incorporating a diaphragm into a hub housing connected to the side end face. It is deformed toward the wheel drive side negative pressure chamber, the slide gear connected to the diaphragm is slid on the driven side axle, the meshing of the slide gear and the outer gear fixed inside the hub housing is released, and the driven The wheel hub is free with respect to the side axle.

  Further, the diaphragm is deformed toward the four-wheel drive side negative pressure chamber by depressurization of the four-wheel drive side negative pressure chamber, and the wheel hub is moved to the driven side axle by meshing the slide gear and the outer gear moving toward the outer gear side. On the other hand, it is locked.

  Here, in order to maintain the two-wheel drive state (free state) or the four-wheel drive state (lock state), the pressure reduction of the two-wheel drive side negative pressure chamber or the four-wheel drive side negative pressure chamber is maintained for a long time. In this case, a large suction force is always applied to the seal member that seals each of the negative pressure chambers and the seal member that seals the negative pressure path communicating with each of the negative pressure chambers, thereby reducing the function of the seal member. , Will reduce durability.

  In order to eliminate such inconvenience, in the above freewheel hub, a magnet is attached to the inner surface of the diaphragm cover that holds the outer peripheral portion of the diaphragm, and the magnet includes a pair of reinforcing plates that sandwich the inner peripheral portion of the diaphragm from both sides. The two-wheel drive state is maintained by the action of adsorbing one outer reinforcing plate.

  Also, a spring is incorporated between the diaphragm cover and the outer reinforcing plate, and the four-wheel drive state is maintained by the action of the spring pressing the diaphragm toward the four-wheel drive side negative pressure chamber. At this time, since the two-wheel drive state cannot be maintained if the magnetic attractive force by the magnet is smaller than the elastic force of the spring, the magnetic attractive force by the magnet is set to a value higher than the pressing force of the spring.

Japanese Patent Laid-Open No. 10-278621

  By the way, in the free wheel hub that maintains the four-wheel drive state by the spring as described above, the slide due to the vibration G occurs when a large axial vibration is loaded on the slide gear in the four-wheel drive state. There is a possibility that the moving force of the gear exceeds the spring load, the spring contracts, and the four-wheel drive state cannot be maintained.

  To prevent this, it is effective to set a large spring load. However, if the spring load is increased, the spring load during two-wheel drive increases and the magnetic force for maintaining the two-wheel drive state is insufficient. As a result, the spring load cannot be increased.

  An object of the present invention is to stabilize the maintenance of a four-wheel drive state and improve the reliability of power transmission in a freewheel hub configured to maintain the two-wheel drive state by a magnetic attractive force by a magnet.

  In order to solve the above problems, in the present invention, a wheel hub of a driven wheel is provided rotatably on the same axis as the driven axle, and the hub hub connected to the outer side end surface of the wheel hub is provided in the hub housing. An outer gear that rotates integrally with the hub housing, and a sleeve is provided on the outer side in the axial direction of the outer gear, and a seal member seals between the sleeve and the opposed surface of the outer gear, and the end of the driven axle that is located inside the hub housing. The outer peripheral part of the diaphragm is slidably fitted to the slide gear and is prevented from rotating, and the outer side end surface of the sleeve and the diaphragm cover having a cylindrical part press-fitted into the outer periphery of the outer end part on the outer periphery Is provided with a two-wheel drive side negative pressure chamber on the outer side in the axial direction of the diaphragm and a four-wheel drive side negative pressure chamber on the inner side in the axial direction. An outer reinforcing plate and an inner reinforcing plate that sandwich the inner peripheral portion of the diaphragm from both sides are coupled by caulking a rivet inserted through the center thereof, and the inner reinforcing plate is connected to the slide gear, and the two wheels Due to the elastic deformation of the diaphragm due to the decompression of the drive side negative pressure chamber, the slide gear is moved in the direction to release the meshing with the outer gear to switch to the two-wheel drive, and the magnet attached to the inner surface of the diaphragm cover magnetically attracts the outer reinforcing plate A free wheel which maintains the switching state to the two-wheel drive by the action and moves the slide gear to the position where it meshes with the outer gear by the elastic deformation of the diaphragm due to the decompression of the negative pressure chamber on the four-wheel drive side. In the hub, a metal moving member that moves toward the four-wheel drive-side negative pressure chamber together with the diaphragm is connected to the four-wheel drive-side negative pressure chamber. Than is adopted the structure in which a suction holding means for holding the switching state of the to four-wheel drive attracted by magnets embedded in.

  In the free wheel hub configured as described above, the diaphragm is elastically deformed into the four-wheel drive-side negative pressure chamber by reducing the pressure on the four-wheel drive-side negative pressure chamber, and the slide gear is moved in the direction of meshing with the outer gear so that the four-wheel drive is achieved. When switched, the four-wheel drive state is maintained by the magnet attracting action of the attracting and holding means.

  As described above, since the maintenance of the four-wheel drive state is based on magnet adsorption, the stability is excellent and the reliability of power transmission can be improved as compared with the case where the four-wheel drive state is maintained by the spring. In addition, since it is not necessary to secure the space for accommodating the spring, the axial length of the freewheel hub can be made compact, and the formation of the spring holding portion required for the diaphragm cover is not required. Therefore, the shape of the diaphragm cover can be simplified.

In the freewheel hub according to the present invention, the one having the following configurations 1 to 4 can be adopted as the suction holding means.
Configuration 1: A configuration in which a magnet is fixed in a magnet housing recess formed on the shaft end surface of the driven-side axle, and an inner reinforcing plate as a moving member is adsorbed by the magnet.
Configuration 2: As a moving member that fixes an annular magnet in an annular groove formed on the shaft end surface of the driven axle and couples and integrates two reinforcing plates by magnetization of a core disposed inside the magnet. A configuration that adsorbs rivets.
Configuration 3: A magnet is fixed to the outer surface of the outer gear, and an outward flange is provided at the opening end of a cylindrical portion formed on the outer peripheral portion of the inner reinforcing plate as a moving member and fitted to the outer diameter surface of the slide gear. The outer flange is configured to be attracted by the magnet.
Configuration 4: The outer gear and the sleeve are integrated, and an annular protrusion is provided on the inner diameter surface of the sleeve portion connected to the outer gear portion, and a magnet is fixed to the outer surface of the annular protrusion, and the inner reinforcement as a moving member A structure in which an outward flange is provided at an opening end of a cylindrical portion formed on the outer peripheral portion of the plate, and the outward flange is adsorbed by the magnet.

  Here, the fixing of the magnet may be performed by adhesion, or may be performed by a molten resin mold with respect to the magnet receiving recess or the annular groove. Moreover, it may be by inward caulking of the opening peripheral portion of the magnet housing recess.

  A cast magnet or a sintered magnet can be adopted as the magnet.

  In the freewheel hub according to the present invention, as described above, the four-wheel drive state is maintained by magnet adsorption, so that the stable four-wheel drive state can be achieved as compared with the case where the four-wheel drive state is maintained by a spring. The wheel drive state can be maintained, and the reliability of power transmission can be improved.

A longitudinal sectional view showing an embodiment of a freewheel hub according to the present invention Sectional view of the four-wheel drive state Sectional drawing which shows the other example of a suction holding means Sectional drawing which shows the other example of a suction holding means Sectional drawing which shows the other example of a suction holding means (I) to (III) are cross-sectional views showing examples of magnet fixing

  Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, a front axle 1 as a driven-side axle and a wheel hub 2 of a front wheel as a driven-side wheel provided outside thereof are arranged coaxially.

  A cylindrical spindle 3 is incorporated between the front axle 1 and the wheel hub 2, and the spindle 3 and the wheel hub 2 are relatively rotatably supported by a bearing 4.

  A hub housing 6 is coupled to the outer end surface of the wheel hub 2 by tightening bolts 5. An outer gear 7 is incorporated in the hub housing 6 and a sleeve 8 is incorporated on the outer side in the axial direction.

  The outer gear 7 has a ring shape, and spline teeth 9 as tooth portions are formed on the inner periphery thereof. Each of the outer gear 7 and the sleeve 8 is fixed to the inner diameter surface of the hub housing 6 by fitting with a spline, and rotates integrally with the hub housing 6. The outer gear 7 and the sleeve 8 are arranged in the axial direction. The opposing surfaces are sealed by incorporating a seal member 10.

  A slide gear 11 is fitted to the shaft end located inside the hub housing 6 of the front axle 1. The slide gear 11 is prevented from rotating around the front axle 1 by fitting of a spline or serration, and is movable in the axial direction. Spline teeth 12 that can mesh with the spline teeth 9 of the outer gear 7 are formed on the outer diameter surface thereof. Is provided.

  A diaphragm 13 is incorporated in the hub housing 6 outside the sleeve 8 in the axial direction. The outer peripheral portion of the diaphragm 13 is sandwiched from both sides by a diaphragm cover 14 having an outer end surface of the sleeve 8 and a cylindrical portion 14a press-fitted to the outer periphery of the outer end portion of the sleeve 8 on the outer periphery.

  The central portion of the diaphragm 13 is sandwiched from both sides by an outer reinforcing plate 15 and an inner reinforcing plate 16, and the outer reinforcing plate 15 and the inner reinforcing plate 16 are coupled and integrated by caulking a rivet 17 that passes through the central portion. Has been.

  The outer reinforcing plate 15 and the inner reinforcing plate 16 are made of a press-formed product of a magnetic metal plate. A cylindrical portion 18 is provided on the outer peripheral portion of the inner reinforcing plate 16, and the opening end of the cylindrical portion 18 is bent inward. Thus, an inner cylinder portion 18a is formed, and the inner cylinder portion 18a is fitted to a cylindrical outer diameter surface 11a formed on the outer periphery of the outer side end portion of the slide gear 11, and is connected to the slide gear 11 in the axial direction. Has been.

  When the inner reinforcing plate 16 and the slide gear 11 are connected in the axial direction, here, a ring groove 19 is formed at the end of the cylindrical outer diameter surface 11 a of the slide gear 11, and a retaining ring 20 fitted in the ring groove 19. The end portion of the inner cylinder portion 18a is engaged.

  By incorporating the diaphragm 13, a two-wheel drive side negative pressure chamber 21 is formed inside the hub housing 6 in the axial direction outside of the diaphragm 13, and a four-wheel drive side negative pressure chamber 22 is formed in the axial direction inside of the diaphragm 13. When the two-wheel drive side negative pressure chamber 21 is depressurized, the diaphragm 13 is deformed toward the two-wheel drive side negative pressure chamber 21, and the slide gear 11 moves in a direction away from the outer gear 7, and the outer gear is moved. 7 is released, and the two-wheel drive state is set.

  Further, by depressurizing the four-wheel drive side negative pressure chamber 22, the diaphragm 13 is deformed toward the four-wheel drive side negative pressure chamber 22, and the slide gear 11 moves toward the outer gear 7 and meshes with the outer gear 7. The four-wheel drive state is set.

  A permanent magnet 23 is attached to the inner periphery of the inner surface of the diaphragm cover 14. The permanent magnet 23 may be annular or discontinuous in the circumferential direction. The permanent magnet 23 attracts the outer reinforcing plate 15 in a two-wheel drive state in which the slide gear 11 is disengaged from the outer gear 7 and maintains the two-wheel drive state.

  FIG. 2 shows a four-wheel drive state in which the slide gear 11 meshes with the outer gear 7, and the four-wheel drive state is held by the suction holding means 30 by attracting the magnet. The suction holding means 30 forms a magnet housing recess 31 on the shaft end surface of the front axle 1, fixes a magnet 32 in the magnet housing recess 31, and sucks the inner reinforcing plate 16 as a moving member with the magnet 32. I have to.

  The magnet 32 may be a cast magnet or a sintered magnet. When the magnet 32 is fixed, the fixing method shown in FIGS. 6 (I) to (III) can be employed. Here, in (I), the magnet 32 is bonded to the closed end face of the magnet housing recess 31. Reference numeral 33 denotes an adhesive. (II) fixes the magnet 32 by inward caulking of the periphery of the opening of the magnet housing recess 31. Reference numeral 34 denotes a caulking piece. (III) molds the magnet 32 by injecting molten resin into the magnet housing recess 31. Reference numeral 35 denotes a resin.

  In FIG. 1, reference numeral 24 denotes a suction path that communicates with the two-wheel drive side negative pressure chamber 21, and reference numeral 25 denotes a suction path that communicates with the four-wheel drive side negative pressure chamber 22. Further, reference numeral 26 denotes a seal member that seals between the suction passage 24 communicating with the two-wheel drive side negative pressure chamber 21 and the suction passage 25 communicating with the four-wheel drive side negative pressure chamber 22.

  The freewheel hub shown in the embodiment has the above-described structure, and the two-wheel drive-side negative pressure chamber 21 is decompressed when traveling by two-wheel drive. Due to the pressure reduction, the diaphragm 13 is deformed toward the two-wheel drive side negative pressure chamber 21, and the slide gear 11 connected to the diaphragm 13 moves away from the outer gear 7, and as shown in FIG. 7 is released, the wheel hub 2 is disconnected from the front axle 1 and becomes free, and the rotation transmission from the wheel hub 2 to the front axle 1 is cut off.

  In the switching state to the two-wheel drive as described above, the magnet 23 attracts the outer reinforcing plate 15. Even if decompression to the two-wheel drive side negative pressure chamber 21 is released by the adsorption, the freewheel hub is maintained in the two-wheel drive state.

  On the other hand, when traveling by four-wheel drive, the four-wheel drive negative pressure chamber 22 is decompressed. Due to the pressure reduction, the diaphragm 13 is deformed toward the four-wheel drive-side negative pressure chamber 22, the slide gear 11 moves toward the outer gear 7, and meshes with the outer gear 7, as shown in FIG. The locked state is coupled to the front axle 1, and the rotation is transmitted from the front axle 1 to the wheel hub 2.

  At this time, since the magnet 32 in the adsorption holding means 30 adsorbs the inner reinforcing plate 16, the diaphragm 13 holds the deformed state toward the four-wheel drive side negative pressure chamber 22, and thus the four-wheel drive side negative pressure chamber. Even if the decompression to 22 is released, the freewheel hub is maintained in the four-wheel drive state.

  Thus, a highly reliable power transmission state can be obtained by maintaining the four-wheel drive state by the action of the magnet 32 attracting the inner reinforcing plate 16.

  In the embodiment shown in FIG. 1, the magnet 32 is fixed to the magnet housing recess 31 formed on the shaft end surface of the front axle 1 as the adsorption holding means 30, and the inner surface of the inner reinforcing plate 16 is adsorbed by the magnet 32. However, the suction holding means 30 is not limited to this.

  3 to 5 show other examples of the suction holding means 30. FIG. In the suction holding means 30 shown in FIG. 3, an annular magnet 37 is fixed in an annular groove 36 formed in the shaft end surface of the front axle 1, and the magnetization of the core 38 disposed inside the magnet 37 A rivet 17 that couples and integrates the outer reinforcing plate 15 and the inner reinforcing plate 16 with the core 38 is adsorbed to maintain the four-wheel drive state.

  In the suction holding means 30 shown in FIG. 4, an annular groove 39 is formed on the inner peripheral portion of the outer surface of the outer gear 7, and an annular magnet 40 is fitted and fixed in the annular groove 39, and the inner reinforcing plate 16 is fixed. An outward flange 18b is provided at an inwardly bent portion of the cylindrical portion 18 formed on the outer peripheral portion of the outer periphery of the magnet. The core 41 is disposed inside the magnet 40 and is magnetized by the magnet 40 to attract the outward flange 18b. Thus, the four-wheel drive state is maintained.

  In the suction holding means 30 shown in FIG. 5, the outer gear 7 and the sleeve 8 shown in FIG. 1 are integrated, and an annular projecting portion 42 is provided on the inner diameter surface of the sleeve portion connected to the outer gear portion. A magnet 43 is fixed to the outer side surface of 42, an outward flange 18 b is provided at an inwardly bent portion of the cylindrical portion 18 formed on the outer peripheral portion of the inner reinforcing plate 16, and the outward flange 18 b is attracted by the magnet 43. Thus, the four-wheel drive state is maintained.

  In any of the suction holding means 30 shown in FIGS. 3 to 5, the four-wheel drive state can be reliably held.

1 Front axle (driven axle)
2 Wheel hub 6 Hub housing 7 Outer gear 11 Slide gear 13 Diaphragm 14 Diaphragm cover 14a Cylindrical portion 15 Outer reinforcing plate 16 Inner reinforcing plate 17 Rivet 18 Cylindrical portion 18b Outward flange 23 Magnet 30 Adsorption holding means 31 Magnet accommodating recess 32 Magnet 33 Adhesion Agent 34 Caulking piece 35 Resin 36 Annular groove 37 Magnet 38 Core 40 Magnet 42 Annular protrusion 43 Magnet

Claims (10)

A wheel hub of a driven wheel is provided rotatably on the same axis as the driven axle, and an outer gear that rotates integrally with the hub housing is connected to an outer side end surface of the wheel hub, and the outer gear A sleeve is provided on the outer side in the axial direction, a seal member seals between the sleeve and the opposed surface of the outer gear, and a slide gear is slidably fitted to the end of the driven axle located inside the hub housing; and The outer periphery of the diaphragm is clamped from both sides by an outer end surface of the sleeve and a diaphragm cover having a cylindrical portion press-fitted into the outer periphery of the outer end portion of the sleeve from both sides, and the outer side in the axial direction of the diaphragm Are provided with a two-wheel drive side negative pressure chamber and an axially inner side of the four-wheel drive side negative pressure chamber. The plate and the inner reinforcing plate are joined by caulking a rivet inserted in the center thereof, the inner reinforcing plate is connected to the slide gear, and the diaphragm is elastically deformed by the pressure reduction of the two-wheel drive negative pressure chamber By moving the slide gear in the direction to release the engagement with the outer gear, the two-wheel drive is switched, and the magnet attached to the inner surface of the diaphragm cover magnetically attracts the outer reinforcing plate to maintain the switching state to the two-wheel drive. A free wheel hub configured to move to a position where the slide gear meshes with the outer gear by elastic deformation of the diaphragm due to the pressure reduction in the negative pressure chamber on the four-wheel drive side, and to switch to four-wheel drive.
Adsorption holding that holds the state of switching to four-wheel drive by adsorbing a metal moving member that moves together with the diaphragm toward the four-wheel drive negative pressure chamber with a magnet incorporated in the four-wheel drive negative pressure chamber A freewheel hub characterized in that means are provided.   2. The freewheel hub according to claim 1, wherein the suction holding means is configured to fix a magnet in a magnet housing recess formed on a shaft end surface of the driven-side axle, and suck the inner reinforcing plate by the magnet.   The attraction holding means is configured to fix an annular magnet in an annular groove formed on an axial end surface of the driven-side axle, and attract the rivet by magnetization of a core disposed inside the magnet. The freewheel hub according to 1.   The attracting and holding means fixes a magnet to the outer surface of the outer gear, and has an outward flange at the opening end of a cylindrical portion formed on the outer peripheral portion of the inner reinforcing plate and fitted to the outer diameter surface of the slide gear. The freewheel hub according to claim 1, wherein the freewheel hub is configured such that an outward flange thereof is attracted by the magnet.   The adsorption holding means integrates the outer gear and the sleeve, provides an annular protrusion on the inner diameter surface of the sleeve portion connected to the outer gear portion, fixes a magnet to the outer surface of the annular protrusion, and The freewheel hub according to claim 1, wherein an outward flange is provided at an opening end of a cylindrical portion formed on an outer peripheral portion of the reinforcing plate, and the outward flange is adsorbed by the magnet.   The freewheel hub according to any one of claims 2 to 5, wherein the magnet is fixed by adhesion.   The freewheel hub according to claim 2 or 3, wherein the magnet is fixed by molding a molten resin to the magnet receiving recess.   The freewheel hub according to claim 2 or 3, wherein the magnet is fixed by inward caulking around an opening portion of the magnet housing recess.   The freewheel hub according to any one of claims 1 to 8, wherein the magnet is a cast magnet.   The freewheel hub according to any one of claims 1 to 8, wherein the magnet is a sintered magnet.

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