JPS6143219B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hub clutch that eliminates the need to go outside the vehicle to operate it.

In a two-wheel drive driving state of a four-wheel drive vehicle, non-driven wheels, for example, front wheels, come into contact with the road surface and receive driving force from the road surface. In this driven state, the driving force is also transmitted to the various mechanisms attached to the front wheels, which reduces running efficiency due to bearing resistance and oil agitation, and causes unnecessary rotation of the drive shaft and gears. This will cause unnecessary wear on them. Therefore, in order to improve these problems, there is a need for a device that limits the driving force received from the road surface to only the wheels and prevents it from being transmitted to subsequent elements.

Examples of hub clutches developed to meet this type of requirement include the following.

FIG. 1 is a schematic structural explanatory diagram (longitudinal sectional view) of a hub clutch that has already been filed by the present applicant (for example, Utility Model Application No. 52-166772 (Utility Model Application No. 54-91547) )reference). The feature of this hub clutch is that the case 110 is attached to the hub 11.
The shaft portion 112a of the bolt 112 connected to the drive clutch 113 is exposed on the inner peripheral surface of the case 110, and the shaft portion 112a of the bolt is slidably inserted into the groove 114 formed on the outer periphery of the driven clutch 113 which can be freely connected to the drive clutch 115. The rotation of the driven clutch is directly transmitted to the bolt through the groove 114, and then to the hub 111 by the bolt 112. Therefore, there is no need for the case 110 itself to have a torque transmission function, and it is therefore possible to use a lightweight material with low strength, such as a light alloy, for the case 110, thereby reducing the weight of the hub clutch. Furthermore, since there is no need to form a spline on the inner circumferential surface of the case 110, it is easy to process the spline, and since the inner diameter of the driven clutch 113 can be made large, it is easy to attach other parts inside it. Various effects can be obtained, such as being able to greatly shorten the overall length of the hub clutch. However, the disadvantage of this hub clutch is that the driver must get out of the vehicle and manually turn the knob 120 when the clutch is engaged or disconnected, that is, when switching from 4-wheel drive to 2-wheel drive or from 2-wheel drive to 4-wheel drive. It must not happen.

Figures 2A and 2B are US Patent No.
2884101 is a longitudinal cross-sectional view and a cross-sectional view of the wheel hub clutch disclosed in No. 2884101. This clutch includes a cylindrical cam (or sleeve) 220 fixed to the drive shaft 212 and having a regular polygonal cross section;
Cylindrical case 228 placed outside this cam
(fixed to the hub part 271 with bolts 276), and a plurality of rollers 224 located between the cam 220 and the case 228 and positioned at equal intervals by a retainer (or roller cage) 226.
and a spring 234. Unless an external force is applied clockwise or in the opposite direction to the retainer 226, this weak contact state is maintained by the spring and no power is transmitted.By switching the select lever from two-wheel drive to four-wheel drive, the drive shaft or The cam rotates, but the retainer does not rotate because the attached friction member is in contact with the fixed system, and the rollers are sandwiched between the cam and the case, and power is transmitted. When the select lever is switched to two-wheel drive, the drive shaft does not rotate, so the retainer returns to its original position due to the spring, cutting off power transmission. In this way, by changing the relative position of the cam and retainer, this hub clutch moves the roller slightly to perform hub clutch switching operations, making it easy and reliable to engage and disengage the hub clutch. It can be carried out.

However, although this hub clutch is called automatic, (a) engine braking does not work. In order to apply engine braking when driving off-road, the driver gets out of the car, turns the manual operation part (switching lever) 270, engages the engaging parts 225 and 271, and directly applies the power from the drive shaft via the guide rod 229. It is necessary to transmit the power to the hub and lock it (power is not transmitted from the roller 224). (b) The structure including the lock mechanism is extremely complex. (c) Lack of durability. (d) It has drawbacks such as being heavy.

In addition, there is also a freewheel hub device disclosed in Japanese Patent Application Laid-Open No. 54-42728. In this device, when the drive shaft rotates,
A thrust force is generated by the resistance between a friction shoe that obtains resistance from a fixed system and a cam ring having a cam surface that engages with a cam surface provided on the shoe, and the cam ring moves in the axial direction. As a result, the clutch ring is pressed in the clutch-on direction via the disc spring, and while compressing the return spring, the outer spline, the inner spline of the body, and the inner spline of the body attain a clutch-on state.

In other words, in this device, the cam section itself functions only to deflect the disc spring 12. Therefore, in such a device, the shift spring (disc spring) and return spring are arranged in series at both ends of the clutch ring, which not only requires a large number of parts but also requires consideration of the axial length. Since the axial width of the clutch ring is restricted, the clutch ring itself tends to fall down, so there is a risk that it will not mesh smoothly with the internal spline portion of the body. Further, since it is difficult to make the spring highly accurate, the biasing force by the spring tends to be unevenly applied, which may encourage the clutch ring to fall. In addition, although the shaft and body are centered using the spacer on the outer periphery of the shaft tip, providing the spacer at such a position may further increase the axial length of the entire device. There is. In particular, with this configuration, it is necessary to protrude at least the outer diameter side of the spacer or the body, so there is a problem that the body becomes large and heavy.

In view of the above points, the present invention is designed to transmit torque in any direction such as engine braking without requiring the driver to get out of the car and perform switching operations when the hub clutch is engaged or disengaged, and is simple in construction, lightweight, durable and reliable. This provides a hub clutch that is superior in terms of performance.

In order to achieve the above object, the hub clutch of the present invention includes a drive clutch whose shaft center is fixedly supported on the outer periphery of a drive shaft, and a spline engaged with the outer periphery of the drive clutch so as to be movable in the axial direction. A slide clutch having a toothed portion and a pin protruding from the outer periphery; the slide clutch is disposed on the outer diameter side of the slide clutch and is integrated with a hub; a cylindrical driven clutch having a tooth profile that connects and disconnects with the tooth profile; an inner circumferential surface of the drive clutch is slidably supported by the outer circumferential surface of the drive clutch; The slide clutch is in dynamic contact and its rotation is braked by the fixed shaft via a brake, and the pin of the slide clutch protrudes inward to engage the arcuate guide groove in a slidable manner, which protrudes outward in the axial direction. and a retainer formed on the overhanging portion.

The present invention will be described in detail below with reference to the drawings.

FIG. 3A is an explanatory view of the configuration of a hub clutch according to an embodiment of the present invention, and is a longitudinal cross-sectional view showing a state in which the hub clutch is disengaged.

A drive clutch 3 fixed to a drive shaft 5 engages with a slide clutch 2 via a spline. The slide clutch 2 has toothed portions 2b on its outer peripheral surface. Driven clutch 1
The slide clutch 2 has a toothed portion 1a on its inner circumferential surface that engages with the gear portion 2b of the slide clutch 2, and its outer circumferential portion is fixed to the hub 12 with bolts 13. A pin 2a, which is a driven member, is driven into the slide clutch 2 in its radial direction. 4 is a snap ring. A brake 8 for braking the rotation of the retainer 6 is mounted on a cylindrical fixed shaft 10 disposed outside the drive shaft 5.
1 so as to be slidable in the rotational direction. 7 is a brake garter spring.

In FIG. 3A, a cam portion that is integrated with the retainer 6 and protrudes to the right is held at a predetermined distance from the outer peripheral surface of the slide clutch 2 radially outward. This retainer 6 is provided with an arcuate cam groove 6a, as shown in a perspective view in FIG.
The arcuate cam groove 6a shown in FIG. 4 is formed in a projecting portion 6b that integrally projects outward in the axial direction from the retainer 6, and the arch stems at both circumferential ends of the arch cam groove 6a extend outward in the axial direction. are located on the inside in the axial direction, and extend in the circumferential direction, and the part connecting them forms an inclined part. Note that the arcuate guide groove (arcuous cam groove) 6a includes not only a through-hole shape as shown in the figure but also a "groove-like" one. A pin 2a driven into the slide clutch 2 is configured to move in this cam groove. In the hub clutch disengaged state shown in FIG. 3A, the pin 2a is at position A shown in FIG. 4. In this state, the slide clutch 2 is located at the rightmost axially outer end of its axial travel path and is therefore not engaged with the toothed portion 1a of the driven clutch 1. The slide clutch 2 rotates with the rotation of the drive shaft 5 and drive clutch 3.
As the pin 2a moves from the position A to the position B or B' shown in FIG. It is configured to engage with the toothed portion 1a. 4, 9 and 14 are snap springs.

The toothed portion 2b of the slide clutch 2, which is pushed leftward (toward the clutch-on side) by the pin 2a moving in the cam groove 6a, meshes with the toothed portion 1a of the driven clutch arranged on its outer periphery. FIG. 3B shows the state when the pin 2a is at position B or B' shown in FIG. 4, that is, when the hub clutch is fully engaged. At this time, as shown in the drawing, the tooth profile 2 of the slide clutch 2
b is completely engaged with the toothed portion 1a of the driven clutch 1. This provides hub clutch engagement, ie four-wheel drive.

FIG. 5 shows another hub clutch according to the invention.
FIG. 5 is an explanatory view of the structure of the hub clutch in a case where the direction of the arcuate cam groove shown in FIG. 4 is reversed, that is, the arched portion of the cam groove is directed outward; In this case, when slide clutch 2 moves to the left, driven clutch 1
is disengaged to provide hub clutch disengagement, and when moved to the right, it engages with driven clutch 1 to provide hub clutch engagement.

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

(1) When switching to four-wheel drive When switching to four-wheel drive by operating a switching lever (not shown) located at an appropriate location on the driver's seat, when the drive shaft 5 is rotated, The drive clutch 3 and slide clutch 2 rotate together with the drive shaft 5. On the other hand, the rotation of the retainer 6 is suppressed by the action of the brake 8. Therefore, relative rotation occurs between the retainer 6 and the slide clutch 2, and the arcuate cam 6
The pin 2a driven into the slide clutch 2 by the action of a moves from the position A shown in Fig. 4 to the position B or
Move to position B′. That is, the slide clutch 2 moves to the left. Therefore, the drive shaft 5 and the driven clutch 1 are coupled to provide four-wheel drive.

(2) When switching to two-wheel drive When switching from four-wheel drive to two-wheel drive by operating the switching lever, first cut off the power to the drive shaft 5 and move the driven clutch 1 in the opposite direction. Rotate (this operation is accomplished by moving the car slightly with the drive wheels in the opposite direction of the car's previous travel direction). The slide clutch 2 and drive shaft 5 are rotated by the driven clutch 1, but the retainer 6 is rotated by the brake 8.
It does not rotate due to resistance. Therefore, relative rotation occurs between the retainer 6 and the slide clutch as in the case of switching to four-wheel drive, and the action of the arcuate cam 6a moves the pin 2a from the position B or B' shown in FIG. Move to the position. Therefore,
The slide clutch 2 moves to the right in the axial direction, disengages from the driven clutch 1, the drive shaft 5 stops, and only the driven clutch 1 idles, providing two-wheel drive.

Further, as shown in FIG. 5, if the cam groove 6a of the retainer 6 has a configuration in which the arched portion of the retainer 6 is directed to the right side, the situation is reversed to that described above, and the slide clutch 2 is
When moving to the left, the hub clutch disengages, thus two-wheel drive, and when moving to the right, the hub clutch engages.
Four-wheel drive is thus obtained.

As described above, the present invention provides a slide clutch that is disposed between the drive shaft and the driven clutch and is moved in the axial direction by an arcuate cam that is interlocked with the brake, and the movement of the slide clutch connects and disconnects the driven clutch. This eliminates the need for the driver to get out of the car and perform switching operations when switching between four-wheel drive and two-wheel drive, that is, when the hub clutch is engaged or disconnected. Torque in any direction, such as engine braking, can be transmitted, and the configuration can be changed. It can be made simple. It also has excellent operational reliability and durability.

Further, the hub clutch of the present invention is disclosed in the above-mentioned Japanese Unexamined Patent Publication No. 54
When compared with the freewheel hub device described in Publication No. 42728, it is superior in the following points.

(a) The cam part (consisting of a cam ring and the cam surface of the friction shoe) of the device described in the above publication serves to deflect a disk spring (shift spring), whereas the hub clutch of the present invention uses an arcuate guide. The pin 2a is projected and engaged in a groove (including a through hole), and the slide clutch 2 is directly moved in the axial direction by the arcuate guide groove (cam part) to turn the clutch on and off. has been done. Therefore, it is not necessary to arrange shift and return springs on both sides of the clutch ring as in the cited example, and there is a great advantage in that two springs can be omitted. Further, by omitting both springs, a sufficient axial length of the slide clutch 2 can be ensured, and as a result, the slide clutch can be prevented from collapsing and the clutch can operate satisfactorily.

(b) Since the device described in the above publication has a shift spring and a return spring arranged at both ends of the clutch ring in the axial direction, pressure on the clutch ring tends to be uneven, causing the clutch ring to fall when it moves in the axial direction. It becomes easier. The collapse of the clutch ring becomes a hindrance to engagement and disengagement during engagement. On the other hand, in the hub clutch of the present invention, the axial movement (clutch on-off) of the slide clutch 2 is realized exclusively by guiding the pin 2a by the arcuate guide groove (arcuous cam groove), so the shift and There is no need for a return spring at all, and the axial length of the slide clutch 2 can be increased accordingly. This prevents the slide clutch from collapsing, and eliminates poor engagement and disengagement when the clutch is turned on and off.

(c) In the case described in the above publication, each member is centered using a spacer at the tip of the drive shaft, so the number of parts increases accordingly, and the outer diameter side of the spacer Since it is necessary to extend the body to this extent, the body may become larger and heavier, and the amount of axial protrusion may also increase. In contrast, in the present invention, the centering of each component is performed via the retainer 6 (which does not move in the axial direction), and at the same time, the retainer 6 also serves as the spacer and cam ring of the above publication. Therefore, it is possible to reduce the size and weight of the driven clutch 1, reduce its axial length, and reduce costs by reducing the number of parts.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the configuration of a conventional hub clutch.
FIG. 2A is a longitudinal cross-sectional view of another conventional hub clutch, FIG. 2B is a cross-sectional view taken along the arrow A-A shown in FIG. 2A, and FIG. A schematic vertical cross-sectional diagram showing a broken hub clutch state;
3B is a longitudinal sectional view showing the state in which the hub clutch is engaged as shown in FIG. 3A, FIG. 4 is a perspective view of the cam shown in FIGS. 3A and 3B, and FIG. 5 is another embodiment according to the present invention. FIG. 1... Drive clutch, 2... Slide clutch, 3... Drive clutch, 4, 9, 14...
...Snat spring, 5...Driveshaft, 6
... Retainer (cam), 7 ... Brake garter spring, 8 ... Brake shoe, 10 ...
Fixed system shaft, 11... Nut, 12... Hub, 13
……bolt.

Claims (1)

[Scope of Claims] 1. A drive clutch whose axis is fixedly supported on the outer periphery of a drive shaft; a spline engagement with the drive clutch so as to be movable in the axial direction on the outer periphery of the drive clutch, and a toothed portion on the outer periphery; A slide clutch having a pin protruding from the top thereof; and a slide clutch disposed on the outer diameter side of the slide clutch and integrated with the hub, and connected to and disconnected from the toothed portion of the slide clutch by axial movement of the slide clutch. a cylindrical driven clutch having a tooth profile, an inner circumferential surface of which is slidably supported by an outer circumferential surface of the drive clutch, and an outer circumferential surface of which is in sliding contact with the inner circumferential surface of the driven clutch; Moreover, the rotation is braked by the fixed system shaft via the brake, and an arcuate guide groove in which the pin of the slide clutch protrudes inward and engages in a slidable manner is formed in the axially outward projecting part. A hub clutch comprising a retainer.