JPH0313060Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention is an automatic freewheel hub clutch equipped with a manual locking means, which prevents incorrect rotation of the knob in the automatic state without increasing the number of parts. Regarding the hub clutch that can be used.

[Conventional technology and problems]

As a conventional freewheel hub clutch (hereinafter referred to as a hub clutch), there is a so-called automatic freewheel hub described in Japanese Utility Model Application No. 60-7227. This vehicle has a structure in which the front wheels and the drive shaft are automatically connected by setting a transfer provided in the transmission section to a four-wheel drive state. However, in this case, there was a risk that the drive shaft and the front wheels would become disconnected when the vehicle moved forward or backward, making it impossible to quickly drive on rough roads. Therefore, there is an idea of adding a manual type mechanism to constantly maintain the connection using a manual type, such as that disclosed in Japanese Utility Model Application Publication No. 121239/1983, but this hub clutch is It has an operation knob for switching between free and lock modes, and a check mechanism disposed at a sliding portion between the operation knob and the opening of the housing which is rotatably supported. This check mechanism consists of a check ball, a spring that biases the check ball, and a recess into which the check ball is biased by the spring and removably fitted, and the knob can be moved between the free position and the lock position. They are each configured to detect that they have been set.

However, when such a check mechanism is used, a special part such as a check ball is used as a check mechanism to detect whether the operating knob is set to the free position or the lock position, which increases the number of parts. However, there are problems in terms of manufacturing cost, ease of assembly, etc., and there is also the disadvantage that the axial length increases by the space in which the check mechanism is disposed. Furthermore, an increase in the number of parts may cause a shortage of parts, and an increase in axial space may cause problems with vehicle width regulations.

In order to avoid various occurrences due to the use of such special parts for checking,
There is a hub clutch described in Publication No. 60-9736. This hub clutch consists of a check recess formed on the cam surface of the operating knob, a retainer that moves along the cam surface, and a shift spring when the clutch ring is engaged with the drive gear by rotating the knob. It has a check mechanism that presses the retainer against the cam surface using a return spring that releases the clutch connection.

However, this hub/clutch check mechanism is possible because the shift spring and return spring are arranged in series, so that a pressing force is applied only in one direction.
This method could only be applied to manual hub clutches, and it was impossible to apply it directly to the check mechanism of hub clutches equipped with an auto-lock mechanism.

[Means and actions for solving problems]

The present invention was made in view of the above, and is an auto freewheel with a manual lock mechanism that does not require special parts for a check mechanism for manual operation and does not require an increase in axial space. A cylindrical case is fixed to the wheel hub and has a spline on the inner periphery and an opening on the outer end surface, and an opening in the case. A knob for manual operation has a boss part that is rotatably attached to the shaft and has a cam surface that slopes from the inside to the outside in the axial direction, and a knob for manual operation that is fixed to the outer periphery of the tip of the ax shaft and has a spline on the outer periphery. a drive gear; a cam member that is spline-engaged with the outer periphery of the drive gear so as to be movable in the axial direction and has a protruding cam portion on the inner side in the axial direction; and a cam of the cam member whose rotation is suppressed by a fixing system. an outer brake having a grooved cam portion and a friction surface that engages with the portion;
a groove-shaped first cam portion that has a brake surface that engages with a friction surface of the outer brake to generate a braking force and that engages with a protruding cam portion of the cam member; and the groove-shaped first cam. a cam ring having a second cam part connected to both sides of the cam ring; and a cam ring that is slidably supported by the spline on the inner periphery of the case and is clutched with the spline on the outer periphery of the drive gear when displaced outward in the axial direction. a clutch ring, a return spring stretched between the cam member and a stepped portion on the outer periphery of the drive gear to press the cam member axially inward; and a return spring that slides on the axially outer surface of the cam member. a shift spring that is stretched between the retainer and the clutch ring and presses the retainer against the cam member; When the knob is set in the auto position, the claws of the retainer are not engaged with the cam surface of the boss portion of the knob,
When the knob is rotated in the manual locking direction, the pawl enters the cam surface of the knob from the inside in the axial direction, moves outward in the axial direction along the cam surface, reaches the lock position, and the pawl portion When the clutch ring and the cam member are in the lock position, the retainer positions the clutch ring and the cam member axially outward, and a check protrusion is provided at the axially outer end of the cam surface of the knob, and an opening of the case is provided. A check cam part is formed in the knob to lock the check protrusion when the knob is set in the auto position.

〔Example〕

Hereinafter, the hub clutch of the present invention will be explained in detail.

1 to 6 a to 6 d show an embodiment of the present invention, in which the hub clutch is attached to the axle shaft 1.
A drive gear 2 having a first spline 3a and a second spline 3b for clutch connection on the outer periphery which are fixedly spline-coupled on the outer periphery of the distal end of the drive gear 2.
and a cam member 4 which is spline-coupled to the second spline part 3b so as to be movable in the axial direction and has a V-shaped cam part 4a protrudingly formed on the inner edge in the axial direction.
Then, the V-groove cam part 7a, which is prevented from rotating by a fixing system (consisting of a spindle, a lock nut, etc.) and into which the thick part on the outer diameter side of the cam part 4a of the cam member 4 is fitted, is attached to the axially outer end. A plurality of outer brakes 8 are provided on the edge, and a first cam portion 9 has a V-shaped groove shape and the inner diameter thick portion of the cam portion 4a fits into the outer edge in the axial direction.
a and second cam portions 9b located on both sides of the first cam portion 9a, and the axially inner outer circumferential surface slides on the axially outer surface of the outer brake 8 via the friction plate 10 to achieve the desired effect. A cam ring 9 that generates a braking force, a friction plate 10 that is disposed between the outer brake 8 and the cam ring 9 and that generates a braking force, and a friction plate 10 that is fixed to a wheel hub (not shown) with a bolt 20 and attached to an inner circumferential surface. A case 24 has a spline 22 and an opening 23 at its end surface, a spline 25a that engages with the spline portion 22 of the case 24 in an axially movable manner on the outer periphery, and a first spline of the drive gear on the inner periphery. a ring clutch 25 having a spline 25b that clutches on and off with the ring clutch 3a; a retainer arm 26a whose rotation is suppressed by the spline 22; and a retainer 26 having a bent portion 26b radially inward on the axially inner side of the retainer arm 26a. A spring holder 4b contacts the inner diameter portion of the cam member 4 and supports the inner circumferential surface of the bent portion 26b of the retainer (the spring holder 4 protrudes further axially outward than the bent portion 26b and serves as a return spring at its end surface). between the stepped portion 3c having the first spline 3a carved on the outer periphery of the drive gear 2 and the end surface of the spring holder 4b (including the end surface of the retainer). The return spring 27 is tensioned, and the shift spring 2 is tensioned between the bent portion 26b of the retainer and the inner wall surface of the ring clutch 25 in the axial direction and urges the ring clutch 25 axially outward (in the direction of clutch engagement).
It consists of 8. A knob 30 is attached to the opening 23 of the case 24 so as to be rotatable manually. A positioning member 1a attached to the tip of the axle shaft is positioned on the inner circumferential surface of the drive gear 2, and a bearing 29 is attached between the positioning member and the inner circumference of a boss portion 32 of the knob, which will be described later. The inner diameter portion of the bearing 29 is locked by the positioning member 1a, while the outer diameter portion is locked by the boss portion 3 of the knob 30.
2 is rotatably supported. Reference numeral 2a denotes a protrusion on the outer periphery of the drive gear, which is separate from the drive gear 2 and fixed with a circlip through spline engagement, and has a positional relationship that allows it to engage with a protrusion 9d inside the cam ring.

As shown in FIG. 1, the axially outer end of the retainer arm 26a of the retainer 26 is bent inward to form a claw portion 26c. The knob 30 has an axially inner boss portion 32, and a cam surface 32a is formed on the outer peripheral surface of the boss portion 32. The cam surface 32a is a surface that is continuously inclined from the inside to the outside in the axial direction, and is configured to be engageable with the claw portion 26c of the retainer 26. The axially inner side of the cam surface 32a is open so that the claw portion 26c can enter and exit, and a recess 32b as a lock position is formed on the axially outer side of the cam surface 32a.
When the claws 26c of the retainer 26 move axially inward along the cam surface 32a by the rotation of the knob 30 and the claws 26c are out of engagement with the cam surface 32a, the state shown in FIG. As shown in FIGS. 5a and 6c and d, the automatic state is reached, and when the pawl portion 26c moves axially outward along the cam surface and is locked in the lock position 32d, as shown in FIGS. 5b and 6d. Figure 6a
As shown in the figure, it is configured to be in a manual lock state.

Reference numeral 32c is a check protrusion formed at the axially outer end of the cam surface 32, and is located on the inner wall surface of the housing 24 corresponding to the check protrusion 32c, and when the knob 30 is set to the auto position. A check cam portion 24a is formed at the location where the check protrusion 32c is located.
The check cam part 24a has a stopper protrusion 24.
b and a small protrusion 24c for preventing return (almost on the same surface as the cam surface 32a). Then, it is seated and locked in the check cam part 24a.

In the above configuration, the operation for transitioning from the clutch-off state shown in FIGS. 2a and 3 to the clutch-on state shown in FIGS. 2b and 4 will be described. First, when the knob 30 is set to the auto position, when driving force from the engine is transmitted to the axle shaft 1, the drive gear 2
Then, the cam member 4 starts rotating integrally. At this time, the cam member 4 presses the cam ring 9 inward in the axial direction, so that the cam ring 9 presses the friction plate 10 against the outer brake 8, thereby braking the clutch ring 9. In the clutch-off state, the cam member 4
The cam surface 4a is the groove-shaped cam portion 7 of the outer brake 8.
a and the first cam surface 9a of the cam ring 9 at the same time, but when the cam member 4 starts rotating due to the rotation of the axle shaft 1, an outward thrust in the axial direction is generated on each cam surface. The force causes the cam portion 4a to be displaced axially outward along each cam surface of each cam portion 7a and 9a. After the cam portion 4a passes over the grooved cam portions 7a and 9a, it then rides on the second cam portion 9b of the cam ring and is displaced axially outward along this. When the meturn spring 27 is deflected by the axial movement of the cam member 4, the ring clutch 25 is moved against the shift spring 28.
is displaced axially outward by the spline 25b.
and the spline 3a are completely engaged (Fig. 2b, Fig. 4). When the clutch is fully engaged, the protrusion 2 fixed to the outer circumference of the drive gear
a engages with a protrusion 9d on the inner periphery of the cam ring 9 and directly rotates the cam ring 9, thereby transmitting rotational torque.

Next, when changing from a four-wheel drive state to a two-wheel drive state, the return spring 27 Due to the expansion force, the cam portion 4a of the cam member 4 is separated from the stopper 9c and displaced inward in the axial direction along the cam portion 9b, and finally the cam portion 7a of the outer brake 8 and the cam of the cam ring 9 It falls into part 9a. In this way, a clutch-off condition is achieved. In the process of axially inward displacement of the cam member 4, the splines 25b of the clutch ring 25 are disengaged from the splines 3a.

At this time, when the knob 30 is set to the auto state, the check protrusion 32c of the knob climbs over the small protrusion 24c and falls into the check cam part 24a of the housing. Unless the check projection 32 is turned in the manual lock direction (manual lock direction), there is no risk that the check protrusion 32 will separate from the check cam portion 24a (processes shown in FIGS. 6b to 6c and d). Therefore, the automatic state (the state in which the claw portion 26c is at the dotted line position in FIG. 6c) can be reliably maintained.

If this check mechanism did not exist, the check mechanism of the knob would be lost when the auto locks, and the knob would become rotatable relative to the case and retainer, and could rotate due to impact or when the auto is free. There is a risk that the retainer may engage with the cam surface of the knob, making it impossible to shift to the free state. When it is difficult to free automatically, there is no other way but to free manually, which is inconvenient. There are cases where the automatic transition to free is not possible, in which case the hub clutches of both wheels lock, and in cases where only one wheel locks. In the case of both wheels being locked, the wheels are rotated in the order of front wheel axle, front differential, and front propeller shaft, resulting in increased running resistance and reduced fuel efficiency. In the case of a single-wheel lock, reverse drive is performed from the outside from the lock side wheel to the lock side axle to the front differential. As a result, differential rotation occurs within the front differential, and there is a risk of seizure due to lack of lubricant.

Further, the pressing force of the return spring 27 is transmitted to the knob 30 through the route shown by the arrow in FIG. Therefore, the engagement between the check protrusion 32c and the check cam portion 24a is held even more firmly.

In the manual lock state shown in FIGS. 5b and 6a, the drive gear 2 and the clutch ring 25 are in a completely connected state at all times, and even if the vehicle body is repeatedly moved forward and backward, the splines 3a and
5a will not come off. In addition, ratcheting does not occur when the splines 3a and 25a mesh with each other, causing wear of the spline portions. Therefore, complete four-wheel drive can be maintained even when starting on a steep slope or the like.
In other words, depending on the road conditions, you can choose between automatic four-wheel drive and manual full four-wheel drive. In addition to starting on a steep slope, for example, when a wheel falls into deep mud and the vehicle body is moved back and forth in an attempt to escape, the splines 3a and 25a are activated each time the automatic four-wheel drive is advanced in reverse. A non-meshing state occurs and a state in which driving force is not transmitted to the wheel makes it difficult to quickly escape.If the knob is set in the locked state, this problem will not occur.

[Effect of idea]

As described above, according to the hub clutch of the present invention, when the knob is set in the auto position, the claw portion of the retainer is in a state of disengagement with the cam surface of the boss portion of the knob, and the knob is moved in the manual lock direction. When the knob is rotated to , the pawl enters the cam surface of the knob from the inside in the axial direction and moves outward in the axial direction along the cam surface to reach the lock position, and when the pawl is in the lock position. The retainer positions the clutch ring and the cam member outward in the axial direction, and a check protrusion is provided at the outer end of the cam surface of the knob in the axial direction, and a check protrusion is provided in the opening of the case. Since the check cam part is formed to lock the check protrusion when the knob is set in the auto position, there is no need to use special parts for the check mechanism, and the knob can be moved easily in the auto position. erroneous rotation can be prevented.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of the entire configuration of an embodiment of the present invention, Figs. 2 a and b are explanatory diagrams of the engaged state of each cam part, and Figs. 3 and 4 are drive diagrams when the clutch is off and on. An explanatory diagram of the engagement state between the gear protrusion and the cam ring protrusion. Figures 5a and b are explanatory diagrams showing the automatic locking state and manual locking state. Figures 6a, b, and c are explanatory diagrams showing the engagement state of the knob. FIG. 6D is a developed explanatory view showing the state of engagement between the check protrusion and the check cam portion of the case, and FIG. 6d is a sectional view showing the state of engagement between the check protrusion and the check cam portion of the case during auto-lock. Explanation of symbols, 1...Axle shaft, 2...
Drive gear, 3a, 3b...spline part, 4
...Cam member, 4a...Cam part, 7a...Cam part, 8...Outer brake, 9...Cam ring,
9a, 9b...cam part, 9c...stopper, 10
... Friction plate, 20 ... Bolt, 22 ... Spline, 23 ... Opening, 24 ... Case, 24a ...
...Check cam portion, 24b... Stopper projection, 24c... Small projection, 25... Ring clutch, 25a, 25b... Spline, 26... Retainer, 26a... Retainer arm, 26b...
Bent part, 26c...Claw part, 27...Return spring, 28...Shift spring, 29...Bearing, 30...Knob, 32...Boss part, 32a...
Cam surface, 32b...Lock position, 32c
...Protrusion for checking.

Claims (1)

[Claims for Utility Model Registration] A cylindrical case fixed to a wheel hub and having a spline on the inner periphery and an opening on the outer end surface; a manual operation knob having a boss portion formed with a cam surface slanting from the inside to the outside; a drive gear fixed to the outer periphery of the tip of the axle shaft and having a spline on the outer periphery;
a cam member that is spline-engaged to the outer periphery of the drive gear so as to be movable in the axial direction and has a protruding cam portion on the axially inner side; and a cam member that is prevented from rotating by a fixing system and is engaged with the cam portion of the cam member. an outer brake having a groove-shaped cam portion and a friction surface; and a groove-shaped groove having a brake surface that engages with the friction surface of the outer brake to generate a braking force and engages with the projecting cam portion of the cam member. a cam ring having a first cam portion and a second cam portion connected to both sides of the groove-shaped first cam portion; a clutch ring that engages with a spline on the outer periphery of the drive gear when the clutch is displaced in the direction; and a return that is stretched between the cam member and a stepped portion on the outer periphery of the drive gear and presses the cam member inward in the axial direction. a spring, a retainer having a claw portion that is in sliding contact with the axially outer surface of the cam member and can be engaged with the cam surface of the knob; and a retainer that is stretched between the retainer and the clutch ring. a shift spring that presses the retainer against the cam member; a check protrusion protrudes from the axially outer end of the cam surface of the knob; 1. A hub clutch characterized in that a check cam portion is formed that locks the check protrusion when set in the hub clutch position.