JPS6121301Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a semi-automatic overrunning clutch mainly used in the front hub of a four-wheel drive vehicle.

When a four-wheel drive vehicle is in two-wheel drive mode, the non-driven wheels, for example the front wheels, receive a driving force from the road surface due to contact with the road surface.
In this driven state, the driving force is also transmitted to the various mechanisms attached to the front wheels, which reduces the running efficiency due to the resistance of the bearings and the stirring of the oil.
It is necessary to restrict the driving force received from the road surface to the wheels and prevent it from being transmitted beyond that.

On the other hand, even in a two-wheel drive driving state, it may be necessary to transmit the driving force received from the road surface when the front wheels come into contact with the road surface to the drive shaft, thereby applying so-called engine braking.

As devices developed for the purpose of meeting this type of demand, there are the devices filed by the applicant of the present application and the device disclosed in Japanese Patent Publication No. 34-9211.

The former has a cone clutch whose friction surface with the case has a cone shape, and a cone/ball clutch shape and/or a cam clutch shape at the joint part with the drive clutch, and this cone clutch is pressed against the joint part of the drive clutch. The structure includes a spring and a brake that suppresses the rotation of the cone clutch.In two-wheel drive driving, the front wheels are normally rolling freely, but as the driving force of the front wheels increases from the road surface, the driving force decreases. The engine brake is automatically transmitted to the drive shaft to apply engine braking. Furthermore, in a four-wheel drive state, the driving force of the drive shaft is automatically transmitted to the front wheels.

In the latter case, a roller is arranged between a sleeve whose outer peripheral surface is shaped like a polygonal column and which is fixed to the drive shaft, and a case (integrated with the hub). The clutch is basically configured to engage and disengage, and is also provided with means for manually selecting the engagement and disengagement operations.

Furthermore, the freewheel hub device disclosed in Japanese Patent Application Laid-open No. 51-2859 does not have a clutch mechanism in which gears mesh with each other, and the pin is engaged in the recessed part of the cage by operating the operation plate. By doing so, the cage and the body are integrated (locked), and therefore, it is impossible to avoid complexity, size, and cost increase due to an increase in the number of parts. Another problem is that high precision is required for each component during assembly.

Furthermore, since there is no means to actively isolate the rollers from the body, for example, when running in 2WD in winter when the lubricating oil around the rollers solidifies and creates large drag resistance, There is a risk that the drive shaft may be rotated by the rotation of the wheel via the roller and inner wheel. Furthermore, since the component force by which the roller is pressed against the inner circumferential surface of the body by the inner is small, there is a risk that the engagement state may change due to slight fluctuations in frictional force, which negates the uncertainty of rotational torque transmission. Can not do it.

This invention was made in view of the above,
By reducing the number of parts, we aim to reduce size, weight, and cost, and prevent malfunctions in winter, etc.
Furthermore, the purpose is to ensure reliable torque transmission during 4WD.

In order to achieve this purpose, the semi-automatic overrunning clutch of the present invention includes an inner cam whose shaft center is fixedly supported by a drive shaft and has a plurality of grooves extending in the axial direction on the outer circumferential surface, and a semi-automatic overrunning clutch of the present invention. A hollow cylindrical outer cam is located concentrically on the outer diameter side of the drive shaft and has a plurality of grooves extending in the axial direction on the inner circumferential surface of the drive shaft. A plurality of rollers are held in grooves on the outer periphery of the inner cam, are in a non-contact state with the outer cam, and are held in relative positions by a retainer, and are interposed between the retainer and the fixing system. When the inner cam starts rotating, it brakes the rolling of the plurality of rollers rotatably supported by the retainer via the retainer, and a roller rolling restraint force based on the braking is applied to the rollers. a brake that, when the elastic holding force is exceeded, causes the plurality of rollers to float outward from the grooves on the outer periphery of the inner cam, and integrally connects the grooves on the outer periphery of the inner cam and the outer cam with the rollers; , a lock mechanism that transmits rotational torque of the outer cam to the inner cam when the inner cam is not driven, and the lock mechanism includes a first tooth profile provided at an axially outer end of the retainer. and a second tooth profile that is spline-engaged to the inner periphery of the outer cam so as to be movable in the axial direction and that can be combined with the first tooth profile on the axially inner surface, and has different polarities alternately on the outer cam surface in the axial direction. A ring-shaped holding plate has a permanent magnet group consisting of N poles and S poles provided at predetermined intervals in the circumferential direction so that It has a permanent magnet group consisting of N poles and S poles arranged at equal intervals with the permanent magnets on the holding plate so that different polarities alternate, and when the relative position in the rotation direction is changed by manual operation. , by generating an attractive force or repulsive force between the permanent magnets on the retaining plate and moving the retaining plate in the axial direction by the attractive force or repulsive force. It is characterized by consisting of an operation plate that releases or combines the two tooth profiles.

Hereinafter, the present invention will be explained in detail with reference to the drawings.

FIG. 1 is a diagram illustrating the structure of a clutch according to an embodiment of the present invention, and is a longitudinal sectional view of the clutch.

The drive clutch 2 is connected to the drive shaft 1 in a spline structure and secured by a retaining ring 3. Grooves 4 are provided in the axial direction of the drive shaft 1 at approximately equal intervals on the outer circumferential surface of the drive clutch 2. In the same direction as this groove 4, case 5 (screw 14
Grooves 6 are provided at regular intervals on the inner peripheral surface of the hub 13 (which is integrally formed with the hub 13). A roller 7 is installed in the groove 4 of the drive clutch 2 using a retainer 9 and a garter spring 8 so as to be able to roll. The spring 8 presses the roller into the groove 4 on the outer periphery of the drive clutch and holds the roller out of contact with the case 5 when the drive clutch 2 and the case 5 are stationary and when the vehicle is running in 2WD.

In order to better understand the above configuration, it will be explained with reference to FIG. FIG. 3 is an explanatory view of the configuration of the drive shaft 1 as seen in a direction (cross section) perpendicular to the axial direction. In the figure, six grooves 4 are provided at approximately equal intervals along the outer peripheral surface of the drive clutch 2.
It is clearly shown that the grooves 6 are spaced apart along the inner circumferential surface of the case 5. Also,
The cross section of each groove forms part of the circumference, and the roller 7
Compared to the circumference of the groove 4, the circumference of the groove 4 is shown to be large, and that of the groove 6 is shown to be approximately equal.By having such a configuration, the operation of the clutch of the present invention is made smooth. Each roller 7 is positioned by a retainer 9, and is pressed into the groove 4 by a garter spring 8, although not shown in FIG. Since these grooves, rollers, etc. act like a cam as will be described later, the drive clutch 2 will be hereinafter referred to as the inner cam 2 and the case 5 as the outer cam 5.

Another configuration will be described with reference to FIG. 1 again.

The brake 10 is supported by a brake holder fixed to one side of the retainer 9, and is pressed against a fixing system 12 by an annular spring 11. The other side of the retainer 9 passes through the through hole 2a of the inner cam 2, and a toothed structure 15 is fixed to the tip thereof, and a toothed structure 16 is coupled to this. The tooth-shaped structure 16 is fixed to a ring-shaped holding plate 17 installed on the inner peripheral surface of the case 5 with a slidable spline structure 18. A permanent magnet group is fixed to the holding plate 17 via a mounting plate 19. As shown in FIG. 2, the permanent magnets 19N and 19S are embedded and supported in the mounting plate 19 at approximately equal intervals and with alternating magnetic poles. At positions facing these permanent magnets 19N and 19S, there is a group of permanent magnets (not shown, but temporarily referred to as 20N and 20S) embedded and supported in the mounting plate 20. The mounting plate 20 is fixed to the operation plate 21 of the manual operation section 22. The manual operation unit 22 has a mounting structure that is connected to the case 5 through an O-ring 23, and the operation plate 2 is connected to the case 5 in the axial direction of the drive shaft 1.
1 can be rotated clockwise or counterclockwise and can be locked at a desired position.

The operation of the clutch having the above configuration will be explained below.

The manual operation unit 22 is operated using the permanent magnets 19N, 1.
This changes the relative positional relationship between 9S, 20N, and 20S. Figure 1 shows permanent magnets 19N and 19S.
This shows a state in which the different poles of 20N and 20S face each other, the holding plate 17 is pulled to the right by the attraction action of the magnet, and the tooth-shaped structure parts 15 and 16 are disengaged. This state is hereinafter referred to as a one-way clutch.
On the other hand, the same poles of permanent magnets 19N, 19S and 20N, 20S are made to face each other, and the holding plate 1
7 to the left, a state in which the tooth-shaped structures 15 and 16 are joined can also be obtained. This state is hereinafter referred to as a two-way clutch.

In both clutches, when the clutch is at rest, the roller 7 is pressed against the groove 4 by the garter spring 8 as shown in FIG.

Therefore, since the rollers 7 can reliably maintain a non-contact state with the case 5 during 2WD running, there is no fear that the drive shaft 1 will be driven from the wheel side in winter.

First, a one-way clutch will be explained. When the inner cam 2 starts rotating due to the drive of the drive shaft 1, the retainer 9 also rotates at the same time.
Due to the action of the brake 10, a force that resists the rotation of the inner cam 2 acts on the retainer 9, and this force overcomes the pressing force (elastic holding force) of the garter spring 8 and pulls up the roller 7 from the groove 4. . Then, the roller 7 fits into the groove 6 of the outer cam 5, and the inner cam 2 and outer cam 5 fit into the roller 7.
Join via. Therefore, inner cam 2
rotation is transmitted to the outer cam 5. and,
When the inner cam 2 stops rotating, the roller 7
returns to the groove 4 of the inner cam 2 by the pressing force of the garter spring 8.

On the other hand, when the inner cam 2 is stationary and the outer cam 5 rotates, the roller 7 is in the groove 4 and the connection between the inner cam 2 and the outer cam 5 is released, and the toothed structure 15 and 16
The bonds are also broken. Therefore, since there is no external force acting on the retainer 9, there is no change in the position of the roller 7, and the rotation of the outer cam 5 is caused by the rotation of the inner cam 2.
is not transmitted. Therefore, the one-way clutch functions only to transmit the driving force of the drive shaft 1 to the hub (outer cam).

Next, the bidirectional clutch will be explained.

The difference between the two-way clutch and the one-way clutch is that the retainer 7 and the case 5 (inner cam 5) are connected via tooth-shaped structures 15, 16, etc. Even in this state, the transmission of the drive of the drive shaft 1 to the outer cam 5 can be considered in the same way as in the case of a one-way clutch, but when no driving force is applied to the drive shaft 1, the outer cam 5 is rotated, a difference from the one-way clutch occurs.
That is, the rotational force of the outer cam 5 is
5 and 16 to the retainer 9, and the roller 7 is pulled up from the groove 4 and placed in the groove 6 of the outer cam 5.
Therefore, the inner cam 2 and the outer cam 5 are connected via the roller 7. Therefore, the rotation of the outer cam 5 is transmitted to the inner cam 2. In this way, the bidirectional clutch can transmit the driving force of the drive shaft 1 to the hub (outer cam) and the rotation of the hub to the drive shaft.

In the operation of the one-way and two-way clutches, the torque transmission between the inner cam 2 and the outer cam 5 is mostly carried out via the rollers 7, and does not place any burden on other parts, such as the retainer. As explained above in detail, the semi-automatic overrunning clutch according to the present invention includes an inner cam whose shaft center is fixedly supported by the drive shaft, and which has a plurality of grooves extending in the axial direction on the outer circumferential surface, and the inner cam. A hollow cylindrical outer cam is located concentrically on the outer diameter side of the drive shaft and has a plurality of grooves extending in the axial direction on the inner circumferential surface of the drive shaft. A plurality of rollers are held in grooves on the outer periphery of the inner cam, are in a non-contact state with the outer cam, and are held in relative positions by a retainer, and are interposed between the retainer and the fixing system. When the inner cam starts rotating, it brakes the rolling of the plurality of rollers rotatably supported by the retainer via the retainer, and a roller rolling restraint force based on the braking is applied to the rollers. a brake that, when the elastic holding force is exceeded, floats the plurality of rollers from inside the groove on the outer periphery of the inner cam in an outer radial direction and integrally connects the groove on the outer periphery of the inner cam with the outer cam by the rollers; , when the inner cam is not driven,
a lock mechanism that transmits the rotational torque of the outer cam to the inner cam, and the lock mechanism includes a first tooth profile provided at the axially outer end of the retainer and a lock mechanism that is axially movable on the inner periphery of the outer cam. It has a second tooth profile that can be freely spline engaged and can be combined with the first tooth profile on the axially inner surface, and is spaced at a predetermined interval in the circumferential direction so that different polarities alternate on the axially outer surface. N pole provided at
A ring-shaped holding plate having a group of permanent magnets consisting of S poles, and permanent magnets on the holding plate such that different polarities alternate on the surface facing the side surface of the permanent magnets on the holding plate. It has a permanent magnet group consisting of N poles and S poles provided at intervals, and when the relative position in the rotational direction is changed by manual operation, an attractive force or a repulsive force is generated between the permanent magnet group and the permanent magnet group on the holding plate. The first
and an operation plate for releasing or connecting the second tooth profile, the structure is simple and manufacturing is easy. Furthermore, since the roller and the cam make surface contact and form a combined state, durability is also good.

Note that the present invention is not limited to the illustrated embodiment, and design changes may be made arbitrarily within the scope of the technical idea of the present invention.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the structure of a clutch according to an embodiment of the present invention. FIG. 2 is an explanatory diagram of the magnet mounting plate. FIG. 3 is an explanatory diagram of the structure of a clutch according to an embodiment of the present invention. Explanation of symbols, 1...Driveshaft, 2...
Inner cam (drive clutch), 3... Retaining ring, 4... Groove, 5... Outer cam (case),
6...groove, 7...roller, 8...garter spring, 9...retainer, 10...brake, 11...
... Annular spring, 12 ... Fixed system, 13 ... Hub, 14 ... Screw, 15, 16 ... Tooth structure,
17...Retaining plate, 18...Spline structure, 1
9, 20... Magnet mounting plate, 19N, 19S, 20
N, 20S...Permanent magnet, 21...Operation board, 22
...Manual operation section.

Claims (1)

[Scope of Claim for Utility Model Registration] An inner cam whose shaft center is fixedly supported by a drive shaft and has a plurality of grooves extending in the axial direction on its outer circumferential surface, and which are concentric on the outer diameter side of the inner cam. a hollow cylindrical outer cam having a plurality of grooves extending in the axial direction on its inner circumferential surface; and when the drive shaft and the outer cam are at rest, elastic holding force causes the inner cam to be held in the grooves on the outer periphery of the inner cam. a plurality of rollers that are held in a non-contact state with the outer cam and whose relative positions are maintained by a retainer; When starting, the rolling of the plurality of rollers rotatably supported by the retainer is braked through the retainer, and the roller rolling inhibiting force based on the braking exceeds the elastic holding force for the rollers. when the inner cam is driven, the inner cam is driven; a lock mechanism that transmits the rotational torque of the outer cam to the inner cam when the retainer is not in use; A second tooth profile is provided on the inner surface in the axial direction to be spline-engaged so as to be freely movable in the axial direction, and the second tooth profile is connectable to the first tooth profile on the outer surface in the axial direction. A ring-shaped holding plate has a group of permanent magnets consisting of N poles and S poles arranged at a predetermined interval, and different polarities are alternately arranged on the surface of the holding plate that faces the side surface of the permanent magnets. As shown in FIG.
It has a permanent magnet group consisting of poles and south poles, and when the relative position in the rotational direction is changed by manual operation, it generates an attractive force or a repulsive force between it and the permanent magnet group on the holding plate, and the attraction A semi-automatic overrunning tool comprising: an operation plate that releases or connects the first and second tooth profiles by moving the holding plate in the axial direction using force or repulsive force. .