JPH01186434A - Hub clutch - Google Patents

Abstract

PURPOSE:To prevent intrusion of foreign matter due to sustained negative pressure by temporarily feeding negative pressure into one of a pair of air-tight chambers, the contacting or separating a drive gear at the side of axle with/ from a housing at the side of an axle hub through utilization of pressure difference between the air-tight chambers. CONSTITUTION:Upon switching to 4WD, negative pressure is fed into one air- tight chamber 91 while the other air-tight chamber 93 is opened. Consequently, one air-tight chamber 91 shrinks while the other air-tight chamber 93 expands. Since a moving member 77 moves a slide gear 47 to the right, the slide gear 47 engages with a drive gear to lock a hub clutch. At this time, a check ball 67 engages in a recess 73 and holds the slide gear 47 at a coupling position. Thereafter, the air-tight chamber 91 is opened to the atmosphere. Since negative pressure is applied in the housing 5 only for a short time, intrusion of foreign matters into the housing can be prevented.

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.

When traveling in wheel drive (hereinafter referred to as 2WD), the driven side propeller shaft, differential device, axle, and other power transmission systems rotate in response to the rotation of the driven wheels. 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 driven wheel from its power transmission system.

There are means for actuating (connecting and disengaging) this hub clutch that use power, and the one described in JP-A No. 61-238516 is one example, and is configured as shown in Fig. 4. .

That is, 201 is a drive gear that engages with the axle 203, 205 is a housing on the wheel hub side, and 207 is a slide gear that moves in the axial direction and engages with the drive gear 201 and the housing 205 to connect them. The housing 205 is rotatably supported on the spindle 213 by means of bearings 209,211. 215 is a flexible diaphragm that partitions the housing 205 into left and right sections, and 217 is a plate that moves left and right together with the diaphragm 215 to engage the slide gear 207 as described above. An airtight chamber 219 formed on the left side of the diaphragm 215 in FIG. Can be switched. When the airtight chamber 219 is in a vacuum state, the diaphragm 21
5 is attracted, the plate 217 moves the slide gear 207 to the left against the force of the coil spring 225, and connects the drive gear 201 and the housing 205.

Therefore, four-wheel drive (hereinafter referred to as 4WD) is possible. Next, when the airtight chamber 219 is brought to atmospheric pressure, the slide gear 207 moves to the right by the biasing force of the coil spring 225, and the connection between the drive gear 201 and the housing 205 is released, and the propeller shaft etc. are wasted during 2WD. I don't have to take her around. A ventilation port 229 is provided in a compartment 227 formed on the right side of the diaphragm 215, allowing the compartment 227 to communicate with the atmosphere.

As described above, a large negative pressure is always applied to the airtight chamber 219 during 4WD driving to connect the drive gear 201 and the housing 205, and therefore foreign substances such as dust and muddy water easily enter from each seal portion.

The foreign matter that enters into the connecting portions such as the slide gear 101 and the sliding surfaces of the bearings 209 and 211 deteriorates the function and durability of these members. Also, ventilation port 2
The movement of movable parts such as the diaphragm 215 is obstructed by freezing of water that has entered the compartment 227 from the compartment 29 and solidification of mud. For these reasons, the function and durability of the hub clutch may be impaired.

Additionally, if the negative pressure fluctuates during 4WD driving and the suction force becomes smaller than the biasing force of the coil spring 225, the biasing force may disengage the slide gear 207 and the drive gear 201 and return to the 2WD state. be.

(Problems to be Solved by the Invention) Therefore, this invention prevents foreign matter such as dust and muddy water from entering.
Therefore, it is an object of the present invention to provide a hub clutch that has improved durability, can maintain normal function for a long time, and has a stable position of the slide gear after movement.

[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 or disconnects the drive gear and the housing by moving in the axial direction, and a pair of air holes formed inside the housing. A closed room and
a moving member that moves due to a pressure difference generated between the airtight chambers by supplying pressure to the airtight chamber, and moves the slide gear between the connection position and the release position; and a moving member that moves the slide gear between the connection position and the release position. It is characterized by comprising a positioning check mechanism.

(Function) When pressure (positive pressure or negative pressure) is supplied to either one of the pair of airtight chambers, a pressure difference is created between these airtight chambers, the airtight chamber on the high pressure side expands, and the airtight chamber on the low pressure side expands. contracts to move the moving member and move the slide gear in one direction in the axial direction. Next, when pressure is supplied to the other airtight chamber, the pressure difference between the airtight chambers is reversed, and the slide gear returns to its original position due to movement of the moving member in the opposite direction. In this way, the slide gear moves between the coupled position and the disengaged position.

When the slide gear moves to the connected position, the drive gear and housing are connected and the hub clutch is locked, and when the slide gear is moved to the release position, the drive gear and housing are disconnected and the hub clutch is locked. It will be in a free state.

Further, since the slide gear that has been moved as described above is positioned at the release position and the connection position by the check mechanism, the pressure supply to the airtight chamber can be stopped at that position.

(Example) An example will be explained with reference to FIGS. 1 to 3. This embodiment applies to a part-time 4WD vehicle, and the axle that becomes the driven side when switching to 2WD, for example, the front engine
It is used in the front axle of rear drive-based (FR-based) 4WD vehicles.

Also, the upper half of Figure 1 shows the hub clutch in its free state, the lower half shows its locked state, Figure 2 shows its locked state with the slide gear held in the connected position, and Figure 3 shows the slide gear in its released position. shows the free state held in . Note that in the following explanation, left and right in the vehicle width direction refer to the left and right directions in these figures.

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

A housing 5 is arranged to surround the axle 1 and the drive gear 3. The housing 5 consists of a bag-shaped top part 7 and a base part 11 having a hub part 9. The base 11 is fitted into a part of the spigot provided on the top 7, and these are fixed together with bolts 13. An O-ring 15 is disposed in a part of this inlet. A wheel (not shown) is attached to the hub portion 9. Further, the housing 5 is rotatably supported on the vehicle body spindle 21 by bearings 17, 19.

A lock nut 23 of the bearing 19 is screwed onto the tip of the spindle 21, and the rotation stopper 29 is engaged with a pawl 27 on a spline 25 provided at the tip of the spindle 21.
is fixed to the lock nut 23 with a screw 31. Furthermore, two seals 35, 37 are arranged between the spindle base 33 and the base 11 of the housing 5.

The axle 1 is connected to a constant velocity joint 39, and
It is rotatably supported on the spindle 21 by a bush bearing 40 disposed between the spindle base 33 and the bush bearing 40 . A seal 41 is provided between the axle 1 and the spindle base 33.
is installed.

Further, the axle 1 includes a stopper ring 43 that contacts and slides on the tip of the spindle 21, and a retaining ring 4 of the stopper ring 43.
5 is attached to restrict leftward movement of the axle 1.

The slide gear 47 is a ring-shaped connecting member, and is connected to the housing 5 by a spline 49 provided on the outer peripheral surface.
It is slidably engaged on a spline 51 provided on the inner circumferential surface of the top portion 7 . Furthermore, a gear portion 55 that engages with a gear portion 53 provided on the outer peripheral surface of the drive gear 3 is provided on the inner peripheral surface of the slide gear 47 . In this way,
The slide gear 47 slides on the spline 51 of the housing 5 and engages with the drive gear 3.
and housing 5 (the lower half of FIG. 1 and the locked state shown in FIG. 2), and the unlocked position where the drive gear 3 is not engaged (the upper half of FIG. 1 and the free state shown in FIG. 3). can move back and forth between the states).

A centering member 61 whose inner and outer edges are slidably supported by stopper rings 57 and 59 is disposed between the drive gear 3 and the top 7 of the housing 5, and is arranged between the axle 1 (drive gear 3) and the housing. Centering between 5 and 5 is performed.

This centering member 61 is provided with a plurality of openings 63 that serve as air circulation holes when the hub clutch is operated.

A check ball 67 and a check spring 69 that urges the check ball 67 inward are attached to a through hole 65 provided in the cylindrical wall of the top portion 7 of the housing 5 from the inner circumference side, and a check spring 69 is attached to the outer circumference side. A plug 71, which is a holder of 69, is screwed on. Also, a check ball 6 is provided on the outer peripheral surface of the spline 49 of the slide gear 47.
Two recesses 73, 75 are provided which engage with 7.

The fourth part 73 is a slide gear as shown in FIG.
The recess 75 is provided at a position where it engages with the check ball 67 when the check ball 47 is in the connected position (locked state).
As shown in the figure, it is provided at a position where it engages with the check ball 67 when the slide gear 47 is in the released position (free state). When the slide gear 47 moves, the check ball 67 retreats due to the deflection of the check spring 69 and then engages with the recess 73 or 75 to hold and cover the slide gear A 747 in the connected position or the released position. In this way, the check ball 67, check spring 69, and plug 71 constitute a check mechanism 72 for the slide gear 47.

Reference numeral 77 is a bag-shaped moving member, and its outer edge portion is engaged with a groove 79 provided in the slide gear 47, so that it is integrated with the slide gear 47. A convex portion 83 having a groove 81 is provided on the right side wall of the moving member 77, and a presser plate 85 is engaged with this groove 81. The diaphragm 87 is a flexible diaphragm, and its inner edge is airtightly sandwiched between the holding plate 85 and the moving member 77, and the thick part provided at its outer edge is connected to the top 7 of the housing 5. It is hermetically bonded to the inner circumferential surface. A folding portion 89 is provided on the diaphragm 87 as an allowance for following the movement of the moving member 77. In this way, the interior of the housing 5 is divided into left and right sides by the moving member 77 and the diaphragm 87, forming an airtight chamber 91 on the right side and an airtight chamber 93 on the left side.

A gap 95 is provided between the axle 1 and the spindle 21, and this gap 95 opens into the airtight chamber 93 on the right side, communicates with an orifice 97 provided in the spindle base 33 on the left side, and further communicates with the orifice 97 provided in the spindle base 33. It is connected to the intake manifold side of the engine via a plug 99 provided at the outlet, a passage 101, and a control valve device 104. In this way, a pressure (negative pressure) supply line 103 connecting the intake manifold 106 of the engine and the airtight chamber 93 is formed.

The cylindrical portion of the housing 5 is provided with an air flow path 105 that opens into the airtight chamber 91 on the right side and opens between the seals 35 and 37 on the left side. This air flow path 105 is connected to the orifice 10 provided in the spindle base 33 via a space 107 between the seal 35 and the seal 37.
9 and further communicates with the control valve device 1 via a plug 111 provided at the outlet of the orifice 109 and a passage 113.
04, and then to the intake manifold 106 of the engine via the same passage as the pressure supply line 103. In this way, a pressure (negative pressure) supply line 115 connecting the intake manifold of the engine and the airtight chamber 91 is formed.

Therefore, if a pressure difference is applied between the airtight chambers 91.93, the moving member 77 moves, and one of the airtight chambers 91.93 expands while the other contracts.

The control valve device 104 is provided in the engine room, and has an input side connected to a pipe for supplying negative pressure from the intake manifold side of the engine and an atmosphere opening section, and an output side connected to the passages 101 and 113. There is. This control valve device 1
04 can be operated, for example, by a changeover switch on the driver's seat instrument, or can be operated in conjunction with a 2WD-4WDl;7J changeover operation means (switch or lever, hereinafter referred to as 2-4 changeover switch). That is, as shown in the table below, when switching to 4WD using the 2-4 changeover switch, the control valve device 104 switches the negative pressure output line so that negative pressure is supplied to the pressure supply line 115 of the airtight chamber 91. At the same time as switching, the other pressure supply line 103 is opened to the atmosphere (A), and when the completion of movement of the slide gear 47 is detected by a sensor or the like, the pressure supply line 115 is opened to the atmosphere (B). Next, when switching to 2WD, the control valve device switches the negative pressure output line so that negative pressure is supplied to the pressure supply line 103 of the airtight chamber 93, and at the same time opens the pressure supply line 115 of the airtight chamber 93 to the atmosphere. C), and in the same way, when the completion of movement of the slide gear 47 is detected, the pressure supply line 103
(D) Next, the function of the hub clutch configured as described above will be explained.

When the 2-4 changeover switch switches to 4WD, as described above, negative pressure is supplied from the negative pressure supply line 115 to the airtight chamber 91, and the airtight chamber 93 is opened to the atmosphere through the negative pressure supply line 103. Due to the pressure difference generated between the airtight chambers 91 and 93, the airtight chamber 91 contracts and the airtight chamber 93 expands. Accordingly, the moving member 77 slides the slide gear 47 to the right connecting position. The slide gear 47 is
As shown in the lower half of FIG. 1, the hub clutch is engaged with the drive gear 3 to lock the hub clutch, thereby connecting the axle 1 and the wheel. At this time, as shown in FIG. 2, the check ball 67 engages with the recess 73 of the slide gear 47 to hold the slide gear 47 in this connected position. Thereafter, the airtight chamber 91 is opened to the atmosphere through the pressure supply line 115. In this state, 4WD driving becomes possible.

When switching to 2WD with the 2-4 changeover switch, negative pressure is supplied from the negative pressure supply line 103 to the airtight chamber 93, and the airtight chamber 91 is opened to the atmosphere through the pressure supply line 115, so that the airtight chamber 91.93 is opened to the atmosphere. An opposite pressure difference occurs between them, causing the airtight chamber 93 to contract and the airtight chamber 91 to expand. Accordingly, the moving member 77 disengages the slide gear 47 from the drive gear 3, slides it to the left release position as shown in the upper half of FIG. 1, and sets the hub clutch in a free state. . At that time, as shown in FIG.
is engaged with the recess 75 of the slide gear 47, and the slide gear 4
7 in this release position.

Thereafter, the airtight chamber 93 is opened to the atmosphere through the pressure supply line 103. In this state, the vehicle enters a 2WD driving state.

In this way, when driving in 2WD, it is possible to separate the non-drive side wheel and its power transmission system to improve fuel efficiency, durability, and reduce noise. systems can be connected.

Further, as described above, when switching between the locked state and the free state, negative pressure is applied to each pressure system for only a few seconds required for the slide gear 47 to move.

Therefore, even if the hub clutch is activated while driving in the rain or on a muddy road, muddy water or the like will not enter the housing 5 through the seals or joints. In addition, since each pressure system is vented to the atmosphere in the engine room, etc., the ventilation port 229, which was necessary in the conventional hub clutch with the configuration shown in Fig. 4, to prevent a decrease in responsiveness to pressure supply, is required. No ventilation holes are required, and dust, muddy water, etc. do not enter through the ventilation holes. Therefore, the function and durability of the bearings and sliding parts do not deteriorate due to foreign matter entering, freezing of water, assimilation of mud, etc., and normal functions can be maintained for a long time.

In addition, since negative pressure is not applied except during operation, and no biasing means such as a return spring is used, the position of the slide gear will not change unintentionally due to fluctuations in negative pressure, unlike in conventional models. Moreover, the position of the slide gear 47 is stabilized by the check mechanism 72.

In this invention, the pressure supplied to the airtight chambers 91, 93 is not limited to negative pressure. A pressure source may be separately prepared to supply positive pressure. In addition, by using both positive pressure and negative pressure, airtight chambers 91.93
It may be configured such that positive pressure is supplied to the expansion side and negative pressure is supplied to the contraction side. Note that a liquid may be used as the pressure medium instead of a gas as in the above embodiment.

Instead of using the diaphragm 87, the inner circumferential surface of the housing 5 and the outer circumferential surface of the moving member 77 may be configured to slide against each other, and a normal sealing material may be placed between these sliding surfaces.

The relationship between the moving direction of the slide gear 47 and the locked state and free state of the hub clutch may be freely selected. For example, if the gear part 55, which is provided at the left end of the slide gear 47 in the above embodiment, is provided at the right end, the slide gear A747 will be in a locked state when it moves to the left, contrary to the embodiment, and will move to the right. It becomes free when you move.

[Effects of the Invention] As described above, by using the hub clutch of the present invention, it is possible to improve fuel efficiency and durability during 2WD driving and reduce noise in a part-time 4WD vehicle. In addition, the hub clutch of the present invention maintains normal function for a long time because foreign matter does not enter into the housing, and stable function is obtained because the position of the slide gear after movement is stable.

[Brief explanation of the drawing]

FIG. 1 shows a hub clutch according to an embodiment of the present invention,
The upper half is a sectional view showing a free state and the lower half is a sectional view showing a locked state, FIGS. 2 and 3 are cross-sectional views of the embodiment shown in FIG. FIG. 3 is a partial sectional view showing a free state, and FIG. 4 is a sectional view of a conventional example. 1... Axle 3... Drive gear 5
...Housing 9...Hub part 47...
Slide gear 72... Check mechanism 77... Moving member 91.93... Airtight room agent Patent attorney
Yasuo Miyoshi

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 or disconnects the drive gear and the housing by moving in the axial direction, and the inside of the housing. a pair of airtight chambers formed in the airtight chambers, and a moving member that is moved by a pressure difference generated between the airtight chambers by supplying pressure to the airtight chambers to move the slide gear between a connected position and a disengaged position. A hub clutch comprising: a check mechanism that positions the slide gear between a connected position and a released position.