JPH07259878A - Hub clutch - Google Patents

Abstract

PURPOSE:To detect an engaging/disengaging condition without using a sensor by enabling a clutch to hold a slide gear moved to a free position and a lock position by a different air pressure and spring energizing force. CONSTITUTION:When an air pressure is generated Pa, a spring 69 is deflected, and a slide gear 51 is moved with a moving member 55 to a lock position, to lock a hub clutch 19. Here, a pawl 73 of the moving member 55, receiving a differential pressure (Pa-W) between energizing force W of the spring 69 and the air pressure Pa, is moved on the first cam surface 85 to an opposed position of a lock holding part 83, and when the air pressure is decreased to zero, the pawl 73 is held to the lock holding part 83 by the energizing force W, to lock the hub clutch 19. Next, when the air pressure is generate Pb, by a differential pressure (Pb-W), the pawl 73 is moved on the second cam surface 85 to a free switching position 97, and when the air pressure is decreased to zero, the moving member 55 and the slide gear 51 are returned to the free position by the force W, also to hold the pawl 73 to the free position by the second holding part 81, so that the hub clutch 19 is placed in a free condition.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION This invention relates to four-wheel drive (4WD).
The present invention relates to a hub clutch that connects and disconnects an axle and wheels in a vehicle.

[0002]

2. Description of the Related Art Hub clutches 201 and 203 as shown in FIGS. 8 and 9 are described in JP-A-61-238516 and JP-A-60-151103, respectively.
These are clutches 213, 215 for connecting and disconnecting the wheel-side housings 205, 207 and the drive axles 209, 211.
And the clutches 213 and 215 are provided in the air chamber 21.
The wheels are connected by applying air pressure (negative pressure) to 7, 219, and the wheels are driven.

Therefore, in order to keep the hub clutches 201 and 203 in the locked state, it is necessary to constantly apply the air pressure, so that the operation time of the vacuum pump is long and the durability is deteriorated. Further, when the engine is stopped, the vacuum pump also stops and the hub clutches 201 and 203 become free. Furthermore, the seals 221 and 22 are locked during locking.
Since pressure is applied to 3, the seals 221 and 223 are easily worn.
If it wears, it is necessary to increase the pump rotation speed to compensate for air leakage, the load on the vacuum pump increases, and locking becomes impossible when air leakage is severe.

In order to prevent such a situation, there is a hub clutch using a heart cam. This is configured to hold the hub clutch in the locked position and the free position by the position holding function of the heart cam, and to switch between these positions by air pressure.

[0005]

However, in this structure, since the two positions are alternately switched by applying the same air pressure, the hub clutch is locked unless the position sensor of the meshing teeth is used. I can't know if I'm free or not. Also, in this hub clutch, once the air pressure is once made zero and the air pressure is restored, the hub clutch returns to the free position.

Therefore, an object of the present invention is to provide a hub clutch which can hold a locked position and a free position without depending on an operating force and can know a locked or free state without using a sensor. And

[0007]

SUMMARY OF THE INVENTION A hub clutch according to the present invention has a spring urging force W and an air pressure P opposed thereto.
In response to this, a slide gear that can move to a lock position where the drive axle side member and the wheel side member engage with each other and a free position where this engagement is released, a moving member that moves integrally with the slide gear, and an air When the pressure P is zero, the biasing force W holds the claws of the moving member at the free position, the lock holding part at the lock position, and the differential pressure (P _a −W) when the air pressure is P _a. When the air pressure is P _b , the first cam surface that guides the claw to the position opposite to the one holding portion and the differential pressure (P _b
-W) a cam having a second cam surface for guiding to the other holding portion and a third cam surface for guiding the pawl to the other holding portion by the biasing force W from this position. Characterize.

[0008]

The one holding portion will be described as a lock holding portion and the other holding portion will be described as a free holding portion. When the air pressure is set to P _a , the spring bends, the slide gear moves to the lock position together with the moving member, and the hub clutch is locked. At this time, the pressure difference between the biasing force W and P _a of the spring (P _a -W)
In response to this, the claw of the moving member moves on the first cam surface and moves to a position facing the lock holding part. When the air pressure is reduced to zero, W causes the claw to be held by the lock holding part and the hub clutch Keep locked.

From here, when the air pressure is set to P _b , the claw moves to the free switching position on the second cam surface by the differential pressure (P _b -W), and when the air pressure is set to zero, the claw moves to the moving member. The slide gear returns to the free position, the pawl is held at the free position by the second holding portion, and the hub clutch is held in the free state.

As described above, when the air pressure is reduced from P _a to zero, the hub clutch is locked as described above, and the air pressure is changed to P _b.
From 0 to 0, it becomes free, and by repeating this operation, switching between lock and free and holding can be performed.

Thus, even if the air pressure is zero, the state at that time can be maintained. Further, since locking and freeing are performed with different air pressures, for example, if the air pressure is switched by a switch, the state of the hub clutch can be known from the position of this switch without using a position sensor. Furthermore, if locked, you can start in 4WD state even if the engine is turned off while the vehicle is stopped.
Similarly, if the hub clutch freezes while the vehicle is stopped in a cold region, 4W
You can start in the D state.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment will be described with reference to FIGS. 1 to 3 are sectional views of an embodiment, and FIG. 7 shows a power system of a 4WD vehicle using the embodiment. Hereinafter, the left and right directions are the left and right directions in this vehicle and FIGS. 1 to 5. In addition, members and the like without reference numerals are not shown.

As shown in FIG. 7, this power system includes an engine 1, a transmission 3, a transfer 5, a front wheel side driving force connecting / disconnecting device 7 included in the transfer 5, a front wheel side propeller shaft 9, a front differential 11 (front wheel side). Differential device), front axles 13, 15, hub clutches 17, 19 of the embodiment, left and right front wheels 21, 23, rear wheel side propeller shaft 25, rear differential 27 (rear wheel side differential device), rear axle 29, 31, left and right rear wheels 33,
35 and the like.

The driving force of the engine 1 is transmitted from the transmission 3 to the rear differential 27 through the transfer 5 and the propeller shaft 25, and distributed to the left and right rear wheels 29 and 31. When the disconnecting device 7 and the hub clutches 17 and 19 are locked, the driving force is transmitted from the transfer 5 to the front differential 11 via the propeller shaft 9 and distributed to the left and right front wheels 13 and 15 to bring the vehicle into the 4WD state. .
When the connection / disconnection device 7 is freed, the front wheels 21 and 23 are separated from the engine 1, and the vehicle enters the two-wheel drive (2WD) state. At this time, the hub clutches 17 and 19 are also freed to prevent wear, vibration, noise and the like of the front wheel side driving force transmission system due to entrainment.

Next, an embodiment will be described by taking the hub clutch 19 on the right front wheel 23 side as an example. As shown in FIGS. 1 to 3, the wheel hub 37 (wheel-side member) is supported on the inner periphery of the hollow spindle on the vehicle body side through bearings, and the drive axle 39 penetrates the wheel hub 37 and extends toward the front axle 15 side. It is connected. A wheel wheel and a brake drum are fixed to the wheel hub 37, and a bag-shaped housing 41 is fixed via an O-ring 43.

The drive gear 4 is provided at the right end of the drive axle 39.
5 (driving axle side member) is spline-connected, and a retaining ring 47 for preventing falling is attached. The drive axle 39 is supported by the wheel hub 37 via a drive gear 45 and a bearing 49. A slide gear 51, which can be engaged with and disengaged from the drive gear 45, is spline-connected to the inner periphery of the wheel hub 37 so as to be axially movable. 1 shows a state in which the slide gear 51 is in a free position where it does not mesh with the drive gear 45, and FIG. 2 shows a state in which the slide gear 51 is in a lock position where it meshes with the drive gear 45. The right front wheel 23 is separated from the engine 1 when the slide gear 51 is in the free position, and is connected to the engine 1 side in the locked position.

A shift spring 53 (spring) for urging the slide gear 51 from the free position to the lock position is arranged between the slide gear 51 and the bearing 49. Also, as shown in FIG.
The moving member 55 having such a shape is in contact. A fixed member 57 is fastened to the moving member 55 with a nut 59, and an inner edge portion of a diaphragm 61 is sandwiched between the two members 55 and 57. The outer edge of the diaphragm 61 is fixed to the inner circumference of the housing 41. A pressure chamber 63 is formed on the left side of the diaphragm 61, and a chamber 65 is formed on the right side.
Are formed. The compartment 65 is open to the atmosphere via a filter 67.

A return spring 69 (spring) is arranged in the compartment 65, and biases the moving member 55 to the left via the fixed member 57. The moving member slide gears 51 55 move integrally pressed against each other by the biasing force W ₂ of the biasing force W ₁ and the return spring 69 of the shift spring 53. The biasing force W ₂ is larger than the biasing force W ₁ . Further, the wheel hub 37 and the drive axle 3 are provided in the pressure chamber 63.
Air pressure P is supplied from an engine-driven air pump through an air flow path 71 formed between the air passageway 9 and the air passageway 9. Air pressure P is the biasing force W (W ₂ -W ₁₎ of the two springs 53,69 and opposite to move the slide gear 51 to the right. The air pressure P is adjusted by a control valve controlled by the controller.

As shown in FIG. 4, the moving member 55 is provided with three claws 73, which are formed by notching the notches, at equal intervals in the circumferential direction. A cam 79 is rotatably arranged on the inner periphery of the housing 41 between the retaining ring 75 and a bearing 77, and the claw 73 is engaged with the cam 79.
As shown in FIG. 5, the cam 79 includes a free holding portion 81, a lock holding portion 83, first, second and third cam surfaces 85, 87,
89 and.

When the air pressure P is zero, each spring 53, 6
The biasing force W of 9 moves the slide gear 51 to the free position in FIG. At this time, the claw 73 of the moving member 55 is held by the free holding portion 81 of the cam 79 as indicated by the arrow 91, and the hub clutch 19 is kept in the free state.

[0021] Here, the slide gear 51 against the biasing force W Increasing the air pressure P to P _a is moved to the locked position of FIG. At this time, as shown in FIG. 5, the claw 73 moves to the range A on the first cam surface 85 and is guided to the position of the arrow 93 by the rotation of the cam 79. Here, when the air pressure P is set to zero, the pawl 73 is held by the lock holding portion 83 as indicated by an arrow 95 by the urging force W, and the hub clutch 19 is kept in the locked state.

Furthermore, increasing the air pressure P to P _a larger P _b, the slide gear 51 is moved to the free switching position shown in FIG. At this time, the claw 73 moves to the range B on the second cam surface 85 and is guided to the position of the arrow 97 by the rotation of the cam 79. When the air pressure P is set to zero, the pawl 73 moves on the third cam surface 89 by the urging force W and is guided to the free holding portion 81 by the rotation of the cam 79 as shown by an arrow 99.
The hub clutch 19 is held in a free state.

Such adjustment of the air pressure P is performed via the controller by switching the switch 101 shown in FIG. When switched to the locked position depicting the switch 101 in the solid line, the controller to zero after the air pressure P to P _a. By this operation, as described above, the hub clutch 19
Is locked and kept in this state. Also, the switch 101
Is switched to the free position drawn by the broken line, the air pressure P becomes P _b
To zero, the hub clutch 19 is switched to the free state and held.

As described above, the hub clutches 17 and 19 are kept free and locked by the cam 79 even when the air pressure P is zero, so that the load on the seals of the air pump and each part of the pressure system is greatly reduced. The durability is improved. Further, since switching between free and lock is performed with different air pressures, for example, if the position of the switch 101 is seen, the hub clutch 17,
We can know 19 states. Furthermore, if the hub clutches 17 and 19 are locked when stopping on a bad road,
Even if the engine 1 is turned off or the slide gear 51 freezes in a cold region, the vehicle can start in the 4WD state.

It should be noted, by providing the teeth of the slide gear 51 to position the drive gear 45 meshed with the position of FIG. 1 in the above embodiment, as opposed to the embodiment, free small air pressure P _a,
It can be configured to switch to the lock with a large air pressure P _b .

[0026]

According to the hub clutch of the present invention, the slide gear is moved to the free position and the lock position by different air pressures and the biasing force of the spring facing the slide gear, and at the same time, the pawl that interlocks with the slide gear is moved. A cam having a holding portion that holds each position and a cam surface that leads to these holding portions is provided. Therefore, since air pressure is not required to hold each position, the durability of the seal between the air pump and each part of the pressure system is greatly improved, and the locked or unlocked state can be easily confirmed.
In addition, the lock holding function can keep the running performance high when the engine is restarted or during the cold season.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a free state of an embodiment.

FIG. 2 is a cross-sectional view showing a locked state of the embodiment.

FIG. 3 is a cross-sectional view showing a free switching state according to an embodiment.

FIG. 4 is a perspective view of a moving member.

FIG. 5 is a development view of a cam.

FIG. 6 is a drawing of a switch.

FIG. 7 is a skeleton mechanism diagram showing a power system of a vehicle using the hub clutch of the embodiment.

FIG. 8 is a sectional view of a conventional example.

FIG. 9 is a cross-sectional view of another conventional example.

[Explanation of symbols]

 19 Hub Clutch 37 Wheel Hub (Wheel Side Member) 45 Drive Gear (Drive Axle Side Member) 51 Slide Gear 53 Shift Spring (Spring) 55 Moving Member 69 Return Spring (Spring) 73 Claw 79 Cam 81 Free Holding Part 83 Lock Holding Part 85 first cam surface 87 second cam surface 89 third cam surface

Claims (1)

[Claims] 1. A movable member can be moved between a lock position where a driving axle side member and a wheel side member are engaged with each other and a free position where this engagement is released by receiving a biasing force W of a spring and an air pressure P opposed thereto. A slide gear, a moving member that moves integrally with the slide gear, a free holding portion that holds the claw of the moving member at a free position by an urging force W when the air pressure P is zero, and a lock holding that holds at a locked position. And the air pressure is P
and the differential pressure (P _a -W) by a first cam surface for guiding the nail at a position facing the one holding portion when _a, the other holding the differential pressure (P _b -W) when the air pressure is P _b A hub clutch, comprising: a cam having a second cam surface that guides a switching position to the other portion and a third cam surface that guides the pawl to the other holding portion by the urging force W from this position.