JP2016153282A - Free wheel hub - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stabilize the maintenance of a two-wheel drive state to improve reliability of power transmission, in a free wheel hub which maintains the two-wheel drive state by magnetic attraction.SOLUTION: A slide gear 11 is moved at the shaft end part of a front side axle 1 rotatably supported to a position of engagement with and release from an outer gear 8 that rotates integrally with a hub housing 7 by the deformation of a diaphragm 13 that forms a two-wheeled drive side negative pressure chamber 23 and a four-wheeled drive side negative pressure chamber 24 in the hub housing. A magnet 32 is mounted on the inner face of a diaphragm cover 14 to maintain a switching state to two-wheeled drive where engagement of the slide gear and the outer gear 8 is released by the action of the magnet to attract an outside reinforcement plate 15 provided outside the diaphragm. A gap 21 is provided between the engagement faces of the cylindrical part 18 of an inside reinforcement plate 16 to prevent the outside reinforcement plate from being released from attraction of the magnet with an inclination generated by absorbing the run-out of the shaft end part of the front side axle by the gap.SELECTED DRAWING: Figure 1

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 the power from the engine and the transmission to the front propeller shaft and the rear propeller shaft, and the two-wheel drive (2WD) and four-wheel drive (4WD) are transferred by the transfer. Switching is performed.

  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 below, a free wheel hub is provided between the driven wheel and the driven axle, and the transfer is switched to two-wheel drive. The driven wheel is separated from the driven axle, and the driven wheel is set in a free state so as to reduce useless running resistance. On the other hand, when the transfer is switched to four-wheel drive, the driven wheel and the driven axle are locked, and 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, and the outside of the wheel hub. 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. Deform toward the wheel drive side negative pressure chamber, slide the slide gear connected to the diaphragm on the driven side axle, release the mesh with the outer gear fixed inside the hub housing, and move it to the driven side axle On the other hand, the wheel hub is in a free state.

  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 a slide gear that moves toward the outer gear side is engaged with the outer gear so that the wheel hub is engaged with the driven side axle. 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. If so, a large suction force is always applied to the sealing member that seals each of the negative pressure chambers and the sealing seal member of the suction path that communicates with each negative pressure chamber, and the function of the sealing member is reduced, Durability will be reduced.

  In order to eliminate such inconvenience, in the above free wheel hub, a magnet is attached to the inner surface of the diaphragm cover that holds the outer periphery of the diaphragm, and the magnet adsorbs an outer reinforcing plate provided outside the diaphragm. The two-wheel drive state is maintained.

  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 conventional freewheel hub, a bush is incorporated in the inside end which is the fixed end of the cylindrical spindle, and the driven axle is rotatably supported by the bush. There is a guide gap between the mating surfaces of the side axles, and there is a possibility that the end of the driven side axle will run around within the range of the guide gap. There are still points to be improved.

  In other words, when a swing occurs at the end of the driven axle in a two-wheel drive state where the slide gear is disengaged from the outer gear, the slide gear supported by the shaft end of the driven axle also swings in the same manner. become. At this time, since the inner reinforcing plate is connected to the slide gear, and the inner reinforcing plate is in a state of sandwiching the diaphragm from both sides with the outer reinforcing plate, the inner reinforcing plate is inclined together with the inner reinforcing plate due to the swing of the slide gear. Is generated, and the holding of the outer reinforcing plate by the magnet is lowered and released, and the two-wheel drive state cannot be maintained.

  An object of the present invention is to stabilize the maintenance of a two-wheel drive state and improve the reliability of power transmission in a freewheel hub that magnetically attracts an outer reinforcing plate with a magnet to maintain the two-wheel drive state. .

  In order to solve the above-described problems, in the first invention, the driven-side axle is rotatably supported by the bush incorporated in the inside end portion of the cylindrical spindle, and is supported rotatably about the spindle. A hub housing that covers the shaft end of the driven-side axle is connected to the outside end of the wheel hub, and an outer gear is provided in the hub housing so as to be integrally rotatable. The driven-side axle is connected to the outer gear. The outer periphery of the diaphragm is supported by the end surface of the sleeve provided on the outer side of the outer gear and the outer periphery of the diaphragm cover connected to the outer side end of the sleeve. The two-wheel drive side negative pressure chamber on the outer side in the axial direction of the diaphragm and the four-wheel drive side negative on the inner side in the axial direction. And a cylindrical portion connected to the slide gear on the outer peripheral portion of the inner reinforcing plate for sandwiching the inner peripheral portion of the diaphragm with the outer reinforcing plate from both sides, and reducing the pressure of the two-wheel drive side negative pressure chamber Due to the elastic deformation of the diaphragm, 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 to the two-wheel drive. In the freewheel hub that maintains the switching state, a guide clearance formed between the cylindrical portion of the inner reinforcing plate and the fitting surface of the slide gear is formed between the driven axle and the bushing fitting surface. Within this range, a configuration was adopted in which a gap having a size capable of absorbing the vibration when the swinging of the slide gear occurred together with the shaft end portion of the driven-side axle was adopted.

  As in the first aspect of the present invention, a gap having a size capable of absorbing the swing of the slide gear when the whirling occurs on the driven axle between the cylindrical portion of the inner reinforcing plate and the fitting surface of the slide gear is provided. As a result, even when the end of the driven axle is swung around the slide gear within the range of the guide gap formed between the fitting surfaces with the bush in the two-wheel drive state in which the magnet attracts the outer reinforcing plate, The vibration is absorbed by a gap formed between the cylindrical portion of the inner reinforcing plate and the fitting surface of the slide gear. For this reason, the outer reinforcing plate is not tilted by the swinging of the shaft end portion of the driven-side axle, and the attracted state is maintained by the magnet and the two-wheel drive state is maintained.

  Here, the outside end surface of the slide gear is formed into an arc surface centered on the swing center of the driven side axle in a state where the slide gear is disposed at the switching position of the two-wheel drive, so that the driven gear and the driven side axle are combined. When the slide gear swings around, the precession is performed while maintaining the state in which the arc surface of the slide gear is in contact with the inner surface of the inner reinforcing plate, and the tilting of the outer reinforcing plate can be prevented more reliably.

  In order to solve the above-mentioned problems, in the second invention, a bush for rotatably supporting the driven axle in the outside end portion of the spindle is provided instead of the formation of the vibration absorbing gap of the first invention. The built-in configuration was adopted.

  As in the second aspect of the invention, by incorporating a bush in the outside end portion of the spindle, the driven-side axle is rotatably supported by two bushes provided at intervals in the axial direction. Therefore, the driven-side axle is smoothly rotated and the occurrence of swinging at the shaft end portion is suppressed, and the outer reinforcing plate is not inclined. As a result, the two-wheel drive state can be reliably maintained.

  Here, when the bush in the outside side end portion of the spindle is a press-molded product, the cost can be reduced as compared with the case where the bush is manufactured by turning. In addition, by using a sintered oil-impregnated bearing as the bush, seizure at the rotation support portion can be prevented, and the driven axle can be smoothly rotated and supported.

  Both the first invention and the second invention can prevent the outer reinforcing plate from tilting in the two-wheel drive maintaining state in which the magnet attracts the outer reinforcing plate, and the two-wheel driving state. It is possible to stabilize the maintenance of the power and improve the reliability of power transmission.

A longitudinal sectional view showing an embodiment of a freewheel hub according to the present invention Sectional drawing which expands and shows a part of FIG. Sectional view showing the four-wheel drive state of the freewheel hub A longitudinal sectional view showing another embodiment of the freewheel hub according to the present invention Longitudinal sectional view showing still another embodiment of the freewheel hub according to the present invention

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

  A cylindrical spindle 3 is incorporated between the front axle 1 and the wheel hub 2. The spindle 3 has a flange 3a at an end on the inside side, and the flange 3a serves as a fixed support. A bush 4 is incorporated in the inside end portion of the spindle 3, and the front axle 1 is rotatably supported by the bush 4.

  A bearing 5 is incorporated on the outer periphery of the spindle 3, and the wheel hub 2 is rotatably supported by the bearing 5.

  A hub housing 7 is connected to the outside end surface of the wheel hub 2 by tightening bolts 6 screwed into the wheel hub 2. An outer gear 8 and a sleeve 9 are incorporated in the hub housing 7 on the outer side in the axial direction.

  The outer gear 8 has a ring shape, and spline teeth 8a as tooth portions are formed on the inner periphery thereof. Each of the outer gear 8 and the sleeve 9 is fixed to the inner diameter surface of the hub housing 7 by fitting with a spline so as to rotate integrally, and a seal member is provided between the axially opposed surfaces of the outer gear 8 and the sleeve 9. Sealed by 10 built-ins.

  A slide gear 11 is fitted to a shaft end portion located inside the hub housing 7 of the front axle 1. The slide gear 11 is prevented from rotating on the front axle 1 by fitting a spline or serration, and is supported so as to be movable in the axial direction. A spline tooth 11a that can mesh with the spline teeth 8a of the outer gear 8 on its outer diameter surface. Is provided.

  A diaphragm 13 is incorporated in the hub housing 7 outside the sleeve 9 in the axial direction. The outer peripheral portion of the diaphragm 13 is sandwiched from both sides by an outer side end surface of the sleeve 9 and a diaphragm cover 14 having a cylindrical portion 14a on the outer periphery of the sleeve 9 that is press-fitted to the outer periphery of the outer side end portion of the sleeve 9. Yes.

  The central portion of the diaphragm 13 is sandwiched between the outer reinforcing plate 15 and the inner reinforcing plate 16 from both sides, and the outer reinforcing plate 15 and the inner reinforcing plate 16 are coupled and integrated by caulking a rivet 17 inserted through the center hole. ing.

  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. The inner cylinder portion 18a is formed, and the inner cylinder portion 18a is fitted to a cylindrical outer diameter surface 11b formed on the outer periphery of the outside side end portion of the slide gear 11 so as to be axially connected to the slide gear 11. It is connected.

  When connecting the inner reinforcing plate 16 and the slide gear 11 in the axial direction, here, a ring groove 19 is formed at the end of the cylindrical outer diameter surface 11 b 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.

  A gap 21 is provided between the cylindrical outer diameter surface 11b of the slide gear 11 and the fitting surface of the inner cylinder portion 18a. The size δ of the gap 21 is such that the swing of the slide gear 11 when the slide gear 11 swings together with the shaft end portion of the front axle 1 within the range of the guide gap 22 formed between the front axle 1 and the bush 4. It is supposed to be a size that can absorb.

  By incorporating the diaphragm 13, a two-wheel drive-side negative pressure chamber 23 is formed inside the hub housing 7 in the axial direction outside of the diaphragm 13, and a four-wheel drive-side negative pressure chamber 24 is formed inside the diaphragm 13 in the axial direction. Has been.

  A ring member 25 is fitted to the outside side end portion of the spindle 3, and the cylindrical portion 25a provided at the outside side end portion of the ring member 25 and the open end portion of the hub housing 7 are opposed to each other in the radial direction. The space between the opposing portions is sealed by the incorporation of the seal member 26.

  The flange 3 a at the inner side end of the spindle 3 and the opposed portion of the wheel hub 2 are sealed by incorporating a pair of seal members 27. Further, the radial facing portions of the front axle 1 and the flange 3 a are also sealed by incorporating the seal member 28.

The flange 3a of the spindle 3, the first port _{P 1} and the second port _{P 2} is provided. The first port P ₁ communicates with the two-wheel drive-side negative pressure chamber 23 via a first suction path 29 formed between the inner periphery of the wheel hub 2 and the outer periphery of the spindle 3 and on the inner diameter surface of the hub housing 7. is two-wheel drive-side negative pressure chamber 23 is depressurized by sucking the first port P _1.

On the other hand, the second port P ₂ communicates via a second suction path 30 provided between the outer periphery of the front axle 1 and the inner periphery of the spindle 3, and sucks the second port P ₂ to thereby drive the four-wheel drive side. The negative pressure chamber 24 is depressurized.

  As shown in FIG. 2, a spring 31 and a magnet 32 are incorporated inside the diaphragm cover 14. The spring 31 urges the slide gear 11 toward the outer gear 8 through the diaphragm 13 and holds the slide gear 11 in a state of meshing with the outer gear 8.

  On the other hand, when the magnet 32 is fixed to the inner surface of the end plate of the diaphragm cover 14 and the diaphragm 13 is deformed toward the negative pressure chamber 23 on the two-wheel drive side, the slide gear 11 is disengaged from the outer gear 8. The outer reinforcing plate 15 is magnetically attracted to hold the slide gear 11 in the disengaged state.

  The freewheel hub shown in the embodiment has the above-described structure. FIGS. 1 and 2 show a traveling state by two-wheel drive, and as shown in FIG. The slide gear 11 is in a state of releasing meshing with the outer gear 8.

In the running state by the two-wheel drive shown in FIGS. 1 and 2, when applying a suction force to the second port P _2, four-wheel drive-side negative pressure chamber 24 is depressurized, the diaphragm 13 is 4-wheel drive-side negative pressure chamber 24 Elastically deforms toward

  Due to the elastic deformation of the diaphragm 13, the slide gear 11 moves toward the outer gear 8 and meshes with the outer gear 8 as shown in FIG. 3, and the wheel hub 2 is in a locked state coupled to the front axle 1. The rotation is transmitted from the front axle 1 to the wheel hub 2.

At this time, the slide gear 11 is held in mesh with the outer gear 8 by the spring 31. Therefore, even when releasing the suction to the second port P _2, locking hubs is maintained in the running state of the four-wheel drive.

Upon switching from the running state of the four-wheel drive shown in FIG. 3 to the running state of the two-wheel drive, it depressurizes the first port P ₁ of the suction force is applied to the two-wheel drive-side negative pressure chamber 23. Due to the reduced pressure, the diaphragm 13 is elastically deformed toward the two-wheel drive-side negative pressure chamber 23, and the slide gear 11 connected to the diaphragm 13 moves away from the outer gear 8, and as shown in FIG. It is disposed at the two-wheel drive switching position where the meshing with the outer gear 8 is released, the wheel hub 2 is disconnected from the front axle 1 and is in a free state, and the rotation transmission from the wheel hub 2 to the front axle 1 is cut off. become.

In the state of switching to the two-wheel drive, the magnet 32 provided in the diaphragm cover 14 attracts the outer reinforcing plate 15. When you break the suction for the first port P ₁ by its adsorption, locking hubs are maintained in the two-wheel drive state.

  In the two-wheel drive maintenance state by the magnet 32 as described above, the guide gap 22 exists between the front axle 1 and the bush 4 that rotatably supports the front axle 1, and therefore, within the range of the guide gap 22. As shown by the arrow a in FIG. 1, a swing occurs at the shaft end of the front axle 1 around a point O that is approximately bisected in the axial length of the bush 4.

  At this time, the slide gear 11 disposed on the shaft end portion of the front axle 1 also swings with the front axle 1, and when the outer reinforcement plate 15 together with the inner reinforcement plate 16 tilts due to the swing, the outer reinforcement plate 15 by the magnet 32. The suction holding becomes unstable and switches to the suction release state, and the two-wheel drive state cannot be maintained.

  However, in the embodiment, as shown in FIG. 2, the front axle is provided between the fitting surface of the cylindrical outer diameter surface 11 b of the slide gear 11 and the inner cylindrical portion 18 a provided on the cylindrical portion 18 of the inner reinforcing plate 16. Since the gap 21 having a size δ capable of absorbing the swing of the slide gear 11 that swings around with the shaft end of the shaft 1 is provided, the swing of the slide gear 11 is absorbed by the gap 21 and the outer reinforcing plate 15 is inclined. It never happens. For this reason, the outer reinforcing plate 15 is held in the attracted state by the magnet 32, and the two-wheel drive state is maintained.

  Here, as shown in FIG. 4, in the state in which the slide gear 11 is disposed at the two-wheel drive switching position, the outside end face 33 of the slide gear 11 is swung around the center O of the front axle 1 shown in FIG. When the slide gear 11 is swung around together with the front axle 1, the arc surface 33 of the slide gear 11 precesses while maintaining a state in contact with the inner surface of the inner reinforcing plate 16. become. For this reason, it is possible to more reliably prevent the outer reinforcing plate 15 from being inclined.

  FIG. 5 shows another embodiment of the freewheel hub. This embodiment is different from the free wheel hub shown in FIG. 1 in that a bush 34 for rotatably supporting the front axle 1 is incorporated in the outside end portion of the spindle 3. For this reason, the same components as those shown in FIG.

  As shown in FIG. 5, by incorporating the bush 34 into the outside end of the spindle 3, the front axle 1 rotates with the two bushes 4, 34 of the bush 4 incorporated into the inside end of the spindle 3. Since it is supported freely, the front axle 1 is smoothly rotated to prevent the shaft end portion from swinging, and the outer reinforcing plate 15 is not tilted. As a result, the two-wheel drive state is reliably maintained, and a highly reliable power transmission state can be obtained.

  Here, if each of the pair of bushes 4 and 34 incorporated in both ends of the spindle 3 is a press-molded product, the cost can be reduced as compared with the case where the bushes are manufactured by turning. Further, if the bushes 4 and 34 are sintered oil-impregnated bearings, seizure at the bushes 4 and 34 that support the front axle 1 can be prevented, and the front axle 1 can be smoothly rotated and supported.

1 Front axle (driven axle)
2 Wheel Hub 3 Spindle 4 Bush 7 Hub Housing 8 Outer Gear 9 Sleeve 11 Slide Gear 13 Diaphragm 14 Diaphragm Cover 15 Outer Reinforcement Plate 16 Inner Reinforcement Plate 18 Cylindrical Part 21 Gap 22 Guide Clearance 23 Two-wheel Drive Side Negative Pressure Chamber 24 Four-wheel Drive Side negative pressure chamber 32 Magnet 33 Arc surface 34 Bush

Claims (5)

A wheel hub that rotatably supports a driven-side axle (1) by a bush (4) incorporated in an inside-side end of a cylindrical spindle (3), and that is rotatably supported around the spindle (3). A hub housing (7) that covers the shaft end of the driven axle (1) is connected to the outside end of (2), and the outer gear (8) can be integrally rotated inside the hub housing (7). A slide gear (11) that can mesh with the outer gear (8) is slidably supported on the shaft end of the driven-side axle (1), and is provided on the outside side of the outer gear (8). The outer peripheral portion of the diaphragm (13) is sandwiched from both sides by the end surface of the sleeve (9) and the outer peripheral portion of the diaphragm cover (14) connected to the outer side end portion of the sleeve (9) A two-wheel drive side negative pressure chamber (23) is provided on the axially outer side of the diaphragm (13), and a four-wheel drive side negative pressure chamber (24) is provided on the inner side in the axial direction, and the inner peripheral portion of the diaphragm (13) is arranged on the outer side. A cylindrical portion (18) connected to the slide gear (11) is provided on the outer periphery of the inner reinforcing plate (16) sandwiched from both sides by the reinforcing plate (15), and the two-wheel drive side negative pressure chamber (23) The magnet is attached to the inner surface of the diaphragm cover (14) by moving the slide gear (11) in a direction to release the meshing with the outer gear (8) by elastic deformation of the diaphragm (13) due to the reduced pressure of the diaphragm cover (14). In the freewheel hub in which (32) maintains the switching state to the two-wheel drive by the action of magnetically attracting the outer reinforcing plate (15),
A guide gap formed between the fitting surface of the driven axle (1) and the bush (4) between the fitting surface of the cylindrical portion (18) of the inner reinforcing plate (16) and the slide gear (11). A freewheel hub characterized in that a gap (21) having a size capable of absorbing the swing of the slide gear (11) when the driven axle (1) swings within the range of (22) is provided.   A circular arc centering on the swing center (O) of the driven axle (1) with the slide gear (11) disposed at the two-wheel drive switching position with the outside end face of the slide gear (11). The freewheel hub according to claim 1, wherein the surface is a surface. A wheel hub that rotatably supports a driven-side axle (1) by a bush (4) incorporated in an inside-side end of a cylindrical spindle (3), and that is rotatably supported around the spindle (3). A hub housing (7) that covers the shaft end of the driven axle (1) is connected to the outside end of (2), and the outer gear (8) can be integrally rotated inside the hub housing (7). A slide gear (11) that can mesh with the outer gear (8) is slidably supported on the shaft end of the driven-side axle (1), and is provided on the outside side of the outer gear (8). The outer peripheral portion of the diaphragm (13) is sandwiched from both sides by the end surface of the sleeve (9) and the outer peripheral portion of the diaphragm cover (14) connected to the outer side end portion of the sleeve (9) A two-wheel drive side negative pressure chamber (23) is provided on the axially outer side of the diaphragm (13), and a four-wheel drive side negative pressure chamber (24) is provided on the inner side in the axial direction, and the inner peripheral portion of the diaphragm (13) is arranged on the outer side. A cylindrical portion (18) connected to the slide gear (11) is provided on the outer periphery of the inner reinforcing plate (16) sandwiched from both sides by the reinforcing plate (15), and the two-wheel drive side negative pressure chamber (23) The magnet is attached to the inner surface of the diaphragm cover (14) by moving the slide gear (11) in a direction to release the meshing with the outer gear (8) by elastic deformation of the diaphragm (13) due to the reduced pressure of the diaphragm cover (14). In the freewheel hub in which (32) maintains the switching state to the two-wheel drive by the action of magnetically attracting the outer reinforcing plate (15),
A freewheel hub comprising a bush (34) for rotatably supporting the driven axle (1) in an outside end of the spindle (3).   The freewheel hub according to claim 3, wherein the bush (34) in the outer side end of the spindle (3) is a press-formed product.   The freewheel hub according to claim 3, wherein the bush (34) in the outer side end of the spindle (3) is a sintered oil-impregnated bearing.

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