JPH01122733A - Hub clutch - Google Patents

Abstract

PURPOSE:To prevent entrance of foreign object and suction of grease by charging and discharging pressure into and from a working chamber so as to extend and retract a piston, and by engaging and disengaging a slide gear to and from a drive gear so as to lock and release a hub clutch. CONSTITUTION:A negative pressure is fed into a vacuum chamber 55 through pressure supply passages 75, 73, 71, 69 from an intake-air manifold of an engine during four-wheel drive operation. Further, a piston 49 is absorbed into the vacuum chamber 55 and is moved leftward overcoming a return spring 61. Simultaneously, a slide gear 33 is moved leftward by means of a shift spring 65 so as to be engaged with a drive gear 3. Thereby a hub clutch is locked to couple an axle 1 with a wheel 14. Meanwhile, upon two wheel drive operation the supply of negative pressure into the vacuum chamber 55 is stopped so that the return spring 61 allows the engagement between the slide gear 33 and the drive gear 3 to be released.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) This invention provides a part-time four-wheel drive vehicle (part-time four-wheel drive vehicle)
This invention relates to hub clutches used in WD vehicles, etc.

(Prior art) For example, in a part-time 4WD vehicle based on a front engine rear drive (FR), when driving in two-wheel drive, the power transmission system such as the propeller shaft, differential device, axle, etc. on the front wheel side is It rotates due to the rotation of the wheel. In order to reduce the accompanying noise, reduced fuel consumption, and shortened lifespan of various parts of the power transmission system, a hub clutch is used to disconnect the front wheels from their power transmission system.

There are means for actuating (connecting and disengaging) this hub clutch that use power, and the one described in Japanese Patent Application Laid-Open No. 61-238516 is one example, and is configured as shown in Fig. 3. .

That is, 101 is a drive gear that engages with the axle 103, 105 is a housing on the wheel hub side, and 107 is a slide gear that moves in the axial direction and engages with the drive gear 101 and the housing 105 to connect them. 109 is a flexible diaphragm that partitions the housing 105 into left and right sections, and 111 is a plate that moves left and right together with the diaphragm 109 and engages with the slide gear 107. Airtight chamber 1 formed on the left side of the diaphragm 109 in FIG.
13 is connected to the intake manifold of the engine via a passage 115, and is switched between a vacuum state and an atmospheric pressure state by a υ1120 valve 117 provided in the middle of the passage 115. When the airtight chamber 113 is in a vacuum state, the diaphragm 109 is attracted, and the plate 111 moves the slide gear 107 to the left against the force of the coil spring 119, thereby connecting the drive gear 101 and the housing 105. Therefore, four-wheel drive is possible. Next, when the airtight chamber 113 is brought to an atmospheric pressure state, the slide gear 10'7 is moved by the coil spring 119.
The drive gear 101 and the hanging 105 are moved to the right by the biasing force, and the connection between the drive gear 101 and the hanging 105 is released, so that the blower shaft [-, etc.] do not rotate around uselessly during two-wheel drive. A ventilation boat 1 is installed in a compartment 121 formed on the right side of the diaphragm 109.
23 is blown to connect compartment 121 to the atmosphere.

(Problems to be Solved by the Invention) As described above, each time the drive gear 101 and the housing 105 are connected, a large negative pressure is applied to the airtight chamber 113, and foreign matter such as dust and water easily enters from each seal portion. . In addition, a drive gear 101, a housing 105, a slide gear 1
Since each sliding portion of 07 is arranged inside the air chamber 113, grease is sucked from the sliding surface each time the airtight chamber becomes negative pressure. Therefore, the durability of these members is reduced due to the foreign matter that has entered and the lack of grease. In addition, water that has entered the compartment 121 from the ventilation boat 123 may freeze during the cold season or solidify mud, which may impede the movement of movable parts such as the diaphragm 109, impairing the function of the hub clutch.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a hub clutch that does not allow foreign matter such as dust or water to enter, thereby improving durability and functionality, and that is easy to maintain and replace.

[Structure of the Invention] (Means for Solving the Problems) The hub clutch of the present invention includes a drive gear on the axle side,
A housing on the wheel hub side that is arranged concentrically with the drive gear, a slide gear that connects the drive gear and the housing by moving to an engagement position, and a bearing that rotationally supports the wheel hub on the fixed side are fastened together. an actuating chamber provided in the nut and in which a piston member is slidably loaded; an urging means for urging the slide gear to a non-engaged position; and a switchable pressure supply device that moves the slide gear to the engagement position via a member.

(Operation) When pressure (positive pressure or negative pressure) is supplied from the pressure supply device, the working chamber expands or contracts, moves the piston member, and moves the slide gear in the axial direction against the biasing force of the biasing means. Move it to one side. When the pressure supply is stopped, the slide gear returns to its original position due to the urging force of the urging means. In this way, the slide gear moves between the engaged position and the released position. When the slide gear moves to the engaged position, the drive gear and the housing are connected, and the hub clutch becomes locked. When the slide gear moves to the release position, the connection between the drive gear and the housing is released, and the hub clutch becomes free. become a state.

Attachment and detachment of the piston member etc. can be performed by operating the nut that fastens the bearing in the same manner as in the conventional case.

(Example) One embodiment will be explained based on FIGS. 1 and 2.

Note that FIG. 1 shows a free state of the hub clutch, and FIG. 2 shows a locked state.

1 is a center shaft, and 3 is a drive gear spline-coupled to the axle 1.

A housing 5 is arranged to surround the axle 1.

The housing 5 consists of a bag-shaped top part 7 and a base part 9 on the right side of the wheel hub 8, which are fixed to each other with bolts 11. The wheel 14 is attached to the hub 8 of the base 9 with the bolt 1.
5 and a nut 17.

The axle 1 is rotatably supported by a spindle portion 19 of a vehicle body frame. Housing 5 has bearings 21.23
The drive gear 3. J: is rotatably supported. Stopper rings 27 and 29 are mounted on the drive gear 3 and the housing 5 to hold the bearing 25. housing 5
A seal 3 is provided between the base 9 of the spindle part 19 and the base of the spindle part 19.
1 is sealed, and the inside of the housing 5 is kept sealed.

The slide gear 1733 is a ring-shaped connecting member, and is slidably engaged with a spline 37 provided on the inner circumferential surface of the housing 5 via a spline 35 provided on the outer circumferential surface.

Furthermore, a spline 41 that engages with three splines provided on the outer circumferential surface of the drive gear 3 is provided on the inner circumferential surface of the slide gear 33 . This slide gear 33 has two positions: a release position on the right where it does not engage with the drive gear 3 (free state shown in FIG. 1) and an engaged position on the left where it engages with the drive gear 3 (lock state shown in FIG. 2). The housing 5 can be reciprocated while sliding on the splines 37 of the housing 5.

A stopper ring 43 and a retaining ring 45 are provided on the inner peripheral surface of the housing 5 to restrict the range of this reciprocating movement of the slide gear 33.
is installed. 47 is a lock nut of the bearing 21.23, which is screwed onto the tip of the spindle portion 19. The lock nut 47 is provided with a recess, and a ring-shaped piston 49 is fitted into the opening of the recess so as to be slidable in the axial direction.
A stopper ring 50 is attached to prevent the stopper ring 9 from falling off. There is an O between the sliding surface of the lock nut 47 and the piston 49.
Rings 51, 53 are attached. In this way,
The concave portion of the lock nut 47 and the piston 49 form a vacuum chamber (airtight chamber) 55 as an operating chamber. A lock nut T-57 for preventing the lock nut 47 from loosening is fitted to the lock nut 47 and the spindle portion 19, and a retaining ring 59 for holding a lock washer 57 is attached to the lock nut 47.

A return spring 61 is disposed inside the vacuum chamber 55, and urges the piston 49 and the slide gear 33, which is in contact with the screw 49 via a needle bearing 63, toward the release position. The needle bearing 63 is attached to the slide gear 33 and held by a stopper ring 64.

A shift spring 65 is disposed between the slide gear 33 and the housing 5, and biases the slide gear 33 toward the engagement position.

Note that when the slide gear 33 and the drive gear 3 are engaged, and the phases of the splines 39 and 41 of both gears do not match, the shift spring 65 acts as a waiting mechanism.

The lock nut 47 is provided with a circumferential groove 67 and a plurality of through holes 69 that communicate the circumferential groove 67 with the vacuum chamber 55.
A through-hole 71 is provided which opens to. There is a gap 73 between the wheel @1 and the spindle part 19, and this gap 73
communicates with the n-hole 71 on the one hand, and is connected to the intake manifold of the engine through an orifice 75 provided at the base of the spindle portion 19 on the other hand. In this way,
A pressure (negative pressure) supply line from the orifice 75 to the n-hole 69 is formed. The pressure supply in this pressure supply line is controlled by the instrument changeover switch or the 2-
It is designed to be switched by a four-way switch or the like, and constitutes a switchable pressure supply device.

Between the axle 1 and the spindle part 19, the spindle part 1
Seven O-rings are arranged at each tip, and a seal 81 and a bush 83 are arranged at the base of the spindle part 19 to make the pressure supply line airtight.

The function of the hub clutch configured as above will be explained.

When the 2-4 changeover switch or lever is operated to switch to four-wheel drive, negative pressure is supplied from the intake manifold to the vacuum chamber 55 through the pressure supply line. The piston 49 is attracted into the vacuum chamber 55 and moves to the left against the urging force of the return spring 61. Along with this, the slide gear 33 slides to the left engagement position by the biasing force of the shift spring 65, and as shown in FIG. and the wheel 14 are connected. In this state, four-wheel drive driving is possible. At that time, if the phases of both splines 39 and 41 do not match,
The holding mechanism of the shift spring 65 operates to enter a preset state, and when both rotate and match the phase, engagement is performed.

In this locked state, relative rotation between the slide gear 33 and the piston 49 is performed smoothly by the needle bearing 63 interposed between them, thereby preventing heat generation and wear. Further, the slide gear 33 is positioned by the stopper ring 43.

When the 2-4 changeover switch or lever is operated to switch to two-wheel drive, the supply of negative pressure is stopped and the vacuum chamber 55
The internal pressure returns to atmospheric pressure, and the return spring 61 slides the slide gear 33 to the right release position against the force of the shift spring 65, releasing the engagement between the slide gear 33 and the drive gear 3. Then, the hub clutch is released and the connection between the axle 1 and the wheel 14 is released.

In this state, the vehicle is running in two-wheel drive.

Also, Volume inside the housing; VO Volume of airtight room: V1 when expanded or deflated Volume change of airtight room ;vI Pressure inside the housing: P.

When the volume of the airtight room changes Pressure inside the housing; PO Then, Po′=Vo÷(Vo+V+)XP.

becomes.

Change in volume of airtight chamber Vl is the volume V of the housing.

Because it is much smaller than VO) ΔV1, In the above equation, Po-=Po.

In this way, the pressure change inside the housing when the hub clutch is activated is minute. Therefore, there is no need for a vent hole to balance the pressure between the inside of the housing 5 and the outside air.

For this reason, foreign substances such as dust, mud, and water do not enter from each seal part, so not only does the function and durability of each sliding part and spline part not deteriorate, but also water, etc. from entering from the ventilation hole. Since there is no intrusion, this will not freeze or solidify and impair the function of the hub clutch.

Furthermore, since the air around the sliding parts and spline parts is not sucked in, grease is not sucked in with the air, resulting in poor lubrication and reduced durability, unlike in conventional hub clutches.

In providing the vacuum chamber (airtight chamber) 55, the lock nut 47, which is a conventional component, is used without adding any special components, so it can be designed compactly, especially short in the axial direction. .

Although the lock nut 47 is a fixed member, it is easy to attach and detach, so it is advantageous in terms of maintenance and replacement of the piston member 49 and the like.

Note that, in addition to gas as in the above embodiment, a liquid may be used as the pressure medium.

Further, the pressure supplied to the working chamber 55 is not limited to negative pressure, and positive pressure may be supplied. In this case, return spring 61
is no longer necessary, and the slide gear 33 is configured to be moved from side to side by the expansion force of the airtight chamber 55 and the biasing force of the shift spring 65.

The relationship between the expansion and contraction of the working chamber 55 and the locked and free states of the hub clutch may be freely selected. For example, if the spline 111 of the slide gear 33, which is provided on the right in the above embodiment, is provided on the left, the airtight chamber 55 will be in a locked state when it expands, and will be in a free state when it contracts, contrary to this embodiment. state.

[Effects of the Invention] As described above, in the hub clutch of the present invention, foreign matter does not enter the inside and grease on the sliding portion is not sucked, so the durability of the sliding portion is improved and normal function is maintained. Furthermore, the seal is simple and compact, and the piston members and the like are easy to maintain and replace.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the present invention in a free state, FIG. 2 is a sectional view showing the same embodiment in a locked state, and FIG. 3 is a sectional view of a conventional hub clutch. 1... Axle 3... Drive gear 8
...Wheel hub 33...Slide gear 47
... Lock nut 49 ... Piston member 55
...Vacuum chamber (operating chamber) 61...Return spring (biasing means) agent
Patent Attorney Tamotsu Miyoshi Male Desire 2

Claims (1)

[Claims] A drive gear on the axle side, a housing on the wheel hub side that is arranged concentrically with the drive gear, a slide gear that connects the drive gear and the housing by moving in the axial direction to an engagement position, and the wheel hub. a working chamber provided in a nut fastened with a bearing for rotational support on the stationary side and in which a piston member is slidably loaded; a biasing means for biasing the slide gear toward a disengaged position; and a positive pressure in the working chamber. Alternatively, a hub clutch comprising a switchable pressure supply device that supplies negative pressure to move the slide gear to an engagement position via the piston member.