JPS6223175B2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field]

The present invention provides a hub with a coaster brake, for example, which is comprised of a clutch cone screwed by a drive body equipped with a sprocket wheel, and a cone-shaped clutch surface formed on the inner periphery of the hub body. This invention relates to an improvement in a clutch device that transmits the rotational force of a drive body to a hub body by pressing a clutch cone against a clutch surface, while allowing the hub body to rotate freely by separating a clutch cone from a clutch surface.

[Prior art and problems to be solved by the invention]

The present inventor previously discovered that in a hub with a coaster brake, etc., the cone-shaped outer surface of the clutch cone screw-fed by the drive body and the cone-shaped inner surface of the clutch cone on the inner periphery of the hub body rub against each other. The so-called cone clutch, which is configured to transmit the driving force that is connected, has conventionally had a narrow taper opening angle, which caused the two clutch surfaces to bite into a wedge shape when the clutches are connected. By increasing the opening angle of the taper and forming pawl teeth in opposite directions on both clutch surfaces, the above-mentioned biting can be eliminated, and at the same time, when driving force is transmitted, the pawl teeth on both clutch surfaces engage and lock the clutch. proposed a clutch device that completely eliminates slippage (see Japanese Patent Application No. 1983-37803). The present invention also proposes a bicycle unit hub in which the improved clutch device as described above is applied as a one-way clutch in place of a so-called freewheel (Japanese Patent Application No. 58-42943 and Japanese Patent Application No. 58-46942). (see issue). The present invention further improves the clutch device proposed by the inventor as described above so that the clutch disengages more smoothly, thereby further expanding the applications of this clutch device. When the clutch device according to the present invention is applied to the hub of a bicycle as shown in FIG. 1, which can be driven forward by reversing the pedals, it becomes possible to put this bicycle into practical use for the first time. The principle of this bicycle is as follows. A pair of free wheels 2 and 3 are arranged in parallel to the hub 1, and the free gears are configured such that the free gear cannot rotate relative to the hub 1 in the normal direction, but can rotate in the relative reverse direction. A chain C is attached to the wheels 2 and 3 as shown in the figure. The freewheels 2 and 3 described above, like ordinary freewheels, are equipped with a ratchet mechanism, which is a one-way clutch, between a core and a free gear body rotatably supported by the core. In the figure, when the pedals are rotated in the forward direction, the chain C travels in the direction A, and only the freewheel 2 rotates in the forward direction, transmitting the driving force of the chain to the hub 1, and the bicycle moves forward. At this time, the freewheel 3 is freely rotating. On the other hand, when the pedals are rotated in the reverse direction, the chain C travels in the direction B, and only the freewheel 3 rotates in the forward direction to transmit the driving force of the chain C to the hub 1, so that the bicycle moves forward in this case as well. At this time, the other freewheel 2 freely reverses. Therefore, this bicycle moves forward both when the pedals are rotated forward and backward. By setting the numbers of teeth of the two freewheels to be different, a bicycle with a two-speed transmission function can be achieved in which the running speed of the bicycle changes depending on when the pedals are rotated in the forward direction and when the pedals are rotated in the reverse direction. It is also possible to create something unique in that the row does not rotate, but moves forward in a rocking motion like a seesaw. However, if you don't give any consideration to the hub of a bicycle like this, you won't be able to make the bicycle go backwards.
A problem arises. In other words, when the bicycle is reversed and the hub is reversed, the two freewheels mentioned above are designed so that their free gear bodies can rotate relative to the core in reverse, but cannot rotate forward relative to the core, so the two freewheels will not be able to rotate forward relative to the core. The child tries to reverse both the two free gear bodies. However, as is clear from the way the chain is engaged as shown in the figure, it is virtually impossible for the two free gears to rotate in the same direction, so as a result, it is impossible to turn this bicycle around.
For example, assuming that a parked bicycle is pulled out to the rear, it is clear that this bicycle cannot be put to practical use unless the above problems are solved. In order to solve the above problems with the bicycle shown in FIG. 1, it is necessary to allow the hub body to freely rotate independently of the two freewheels when the bicycle is stopped. However, if the hub body rotates freely without regard to the freewheel while the vehicle is running, normal running will not be possible, so a power transmission path between the freewheel and the hub body must be secured while the vehicle is running. This is where the clutch device of the present invention can be applied within the hub.
When the clutch device improved according to the present invention is applied to the hub of the bicycle shown in FIG. 1, the above-mentioned problems of this bicycle are successfully solved, and the bicycle can be put into practical use for the first time. That is, an object of the present invention is that when the hub body rotates in the forward direction when the drive body is stopped, the power transmission path between the drive body and the hub body is completely cut off, and at this time, the hub body rotates in the forward and reverse directions with respect to the drive body. To provide a clutch device that can freely rotate in both directions, and connects the drive body and the hub body when the drive body rotates in the forward direction, so that the rotational force of the drive body is transmitted to the hub body. That's true.

[Means to solve the problem]

In order to achieve the above object, the present invention takes the following technical measures. That is, the present invention includes: a hub axle; and a rotatably supported hub axle at one end thereof;
A drive body having a sprocket on the outside and a screw shaft on the inside; a drive body rotatably supported on the inner circumference of both ends by the other end of the hub shaft and the outer periphery of the drive body; A hub body having a conical inner surface with a conical inner surface whose diameter increases inwardly, and a hub body is screwed onto the helical shaft portion so as to be threaded toward the inner surface of the clutch when the helical shaft portion rotates in the normal direction, A bicycle unit hub or a hub with a coaster brake, etc., which has at least the following: a clutch cone having a conical outer clutch outer surface that can be tightly joined to the inner surface; , is characterized in that engaging protrusions with smooth tops that can engage with each other are provided.

[Action and effect]

When the drive body is rotated in the normal direction (clockwise rotation with respect to the hub axle when viewed from the right side of the bicycle is called normal rotation, and counterclockwise rotation is called reverse rotation. The same applies hereinafter), the screw shaft of this drive body rotates. The clutch cone is moved toward the inner surface of the clutch on the hub body, and the outer surface of the clutch is joined to the inner surface of the clutch on the hub body, and the engaging protrusions on both clutch surfaces engage with each other, ensuring that the driving force of the drive body is transferred to the hub. convey to the body. On the other hand, when the pedal is stopped and the rotation of the drive body is stopped while riding, the hub body is rotating in the forward direction due to the coasting of the bicycle, so the engaging protrusion on the inner surface of the clutch is In order to forcibly rotate the clutch cone in the forward direction by engaging the engagement protrusion of the clutch cone, the clutch cone is sent away from the inner surface of the clutch on the screw shaft of the drive body, and the clutch cone is moved away from the inner surface of the clutch on the screw shaft of the drive body. Even if the clutch cones are disengaged, the clutch cone will slightly overrun, ensuring that the power transmission from the clutch device is interrupted. When the power transmission from the clutch device is cut off, the hub body can freely rotate not only in the forward direction but also in the reverse direction. In addition, in order to reliably transmit driving force to the hub body, cone clutches conventionally used in hubs with coaster brakes, etc., narrow the opening angle of the cone's taper to reduce the wedge effect when the clutch is connected. However, due to its structure, it was not possible to simultaneously satisfy both reliability of drive transmission and good clutch disengagement. When the clutch device of the invention is applied to a hub with a coaster brake, reliability of drive transmission can be satisfied. Among the above-mentioned technical means of the present invention, the unique effect of smoothing the tops of the engaging protrusions to be provided on both clutch surfaces will be made clear in the following description of the embodiments.

[Explanation of Examples]

Hereinafter, one embodiment of the present invention will be specifically described with reference to the drawings. The drawings illustrate the use of the invention in a unit hub specifically constructed for use in the bicycle drive shown in FIG. In FIGS. 2 and 3, 11 is a hub body;
Reference numeral 12 denotes a drive body having a pair of freewheels 2 and 3 having different numbers of teeth attached to its outer part, and a right-handed screw shaft portion 13 extending into the inside of the hub body 11. Reference numeral 14 denotes a screw shaft of the drive body 12. A clutch cone is shown which is screwed onto the portion 13 and is movable back and forth in the direction of the hub shaft 15 as the drive body 12 rotates. The pair of freewheels 2 and 3 are preferably aligned in the axial direction and have their cores 17 and 18 screwed to the screw shaft portion 16 formed on the outer part of the drive body 12. The axial length of the core 18 of the wheel 3 is made longer than the screw shaft portion 16 of the drive body 12,
First, after screwing the freewheel 3 onto the screw shaft 16, the attachment 19, which has a screw shaft having the same diameter as the screw shaft 16, is attached to the core 1 of the freewheel 3.
8, and the core 17 of the freewheel 2 is screwed into this attachment 19, so that the freewheel 2 can be connected to the outside of the freewheel 3 as appropriate. These freewheels 2 and 3 may be of a known structure in which a gear body is rotatably supported in only one direction relative to a core by interposing a ratchet mechanism. The drive body 12 includes a wand 20 formed on its outer inner periphery and a ball pusher 21 screwed to the hub shaft 15.
By interposing a plurality of rollable steel balls 22 between the hub shaft 15 and the hub shaft 15, it is possible to rotate the hub shaft 15. Further, the hub body 11 is formed between the one 23 provided on the inner periphery of the left end thereof and the ball receiving member 24 screwed to the left side of the hub shaft 15, and on the inner periphery of the right end of the hub body 11. By interposing a plurality of rolling steel balls 27 and 28 between the ball receiver 25 and the ball receiver surface 26 formed on the inner shoulder of the drive body 12, the hub axle 15 is It is possible to rotate relative to both the drive body 12 and the drive body 12. The hub body 11 is connected to the drive body 1 by a clutch device 29 of the present invention, which will be described next.
When the drive body 2 attempts to drive in the forward direction, this driving force ensures that the drive body 1 rotates in the forward direction.
2 is released, or when the driving force of the driving body 12 is released.
When it is stopped, it can rotate freely not only in the forward direction but also in the reverse direction. The clutch device 29 has an inwardly expanding cone-shaped clutch inner surface 3 having an engaging protrusion 30 with a smooth top on the inner circumferential surface of the right end of the hub body 11.
1 and the helical shaft portion 13 of the drive body 12.
It is constructed by forming a cone-shaped clutch outer surface 33 having an engaging protrusion 32 with a smooth top that can be joined to the clutch inner surface 31 on the outer periphery of the clutch cone 14 screwed to the clutch cone 14,
Furthermore, in this embodiment, by interposing a friction member between the clutch cone 14 and the hub shaft 15, the hub shaft 15 of the clutch cone 14 is
The clutch cone 14 is provided with a configuration in which a constant frictional resistance is applied to the relative rotation with respect to the clutch cone 14, and the clutch cone 14 is always elastically urged in a direction away from the clutch inner surface 31. The clutch inner surface 31 and the clutch outer surface 33
The smooth engaging protrusions 30 and 32 provided on the
For example, as detailed in FIG.
It can be similar to a ratchet tooth having a cross-sectional shape in which a gentle ascending slope 34 and a somewhat steep descending slope 35 are connected by a smooth apex having an arcuate cross-section. However, it is not possible to have tooth tips that stand out at an acute angle, such as ratchet teeth, and it is important that the shape of the ridges be gentle with an acute angle. As shown in FIG. 6, the engaging protrusion 30 on the clutch inner surface 31 and the engaging protrusion 32 on the clutch outer surface 33 may be formed in the same shape, but their directions are reversed so that they can come into close contact with each other. It is becoming. Moreover, when the clutch cone 14 transmits the driving force to the hub body 11, the steep slopes 35 of the clutch cones 14 join together. These engaging protrusions 30 and 32 do not necessarily have to be formed as shown in the illustrated example, but may have various shapes such as triangular, trapezoidal, or round cross-sections, or a combination of these. can do. In addition, in the illustrated example, the clutch inner surface 3
The engaging protrusions 30 of the clutch outer surface 33 are formed continuously and the engaging protrusions 32 of the clutch outer surface 33 are formed intermittently. The portions 30 may be formed intermittently, or both may be formed continuously or intermittently. Furthermore, in the clutch device 29 of this embodiment,
The clutch cone 14 is always attached to the clutch inner surface 31.
In the illustrated example, the second
The elastic force is applied in the Q direction in the figure, and this can be configured, for example, as follows. A space 37 is formed between the axial inner hole 36 in the helical shaft portion 13 of the drive body 12 and the hub shaft 15, and a compression coil spring 38 is inserted into the space 37 so as to be inserted into the hub shaft 15. The clutch cone 1 is inserted using the compression coil spring.
4 is elastically biased. The outer end of the compression coil spring 38 is brought into contact with, for example, the inner end wall of the cone spring 21 and is slightly reduced in diameter so as to be wound around the hub axle 15.
It is engaged with an engaging portion of a donut disc-shaped locking plate 39 that is slidably fitted into the lock plate 5 . Furthermore, the inner wall of the outer peripheral part of this locking plate 39 is connected to the clutch cone 1.
The retaining ring 40 is fitted into the inner periphery of the retaining ring 40 and is brought into contact with the outer wall of the retaining ring 40. Thus, the locking plate 39, which is constantly pushed in the direction of arrow Q in FIG. 2 by the elasticity of the compression coil spring 38, moves the retaining ring 40 in the direction of arrow Q in FIG.
As a result, the clutch cone 14 is always elastically urged in the direction of arrow Q in FIG. 2. The outer end of the compression coil spring 38 may be wound around the hub axle 15 as described above, or an appropriate engagement portion may be provided on the ball pusher 21 and engaged therewith. In addition, as a means for elastically biasing the clutch cone, in the illustrated example, a compression coil spring is interposed on the right side of the locking plate 39 to push the locking plate in the direction Q in FIG. Of course, the locking plate 39 may be pulled in the direction Q in FIG. 2 by interposing a tension spring (not shown) on the left side of the locking plate 39. Furthermore, in the clutch device 29 of this embodiment, a certain amount of frictional resistance is applied to the relative rotation of the clutch cone 14 with respect to the hub shaft 15.
In the illustrated example, the inner circumference is attached to a shaft portion 41 formed inside the ball receiver 24 fixed to the hub shaft 15, and the outer circumference is attached to the inner circumference of the clutch cone 14. It is constructed by interposing a spiral spring 42 that makes elastic sliding contact. In addition,
If the elasticity of the compression coil spring 38 is increased to a certain extent, a certain degree of sliding resistance can be obtained between the locking plate 39 and the retaining ring 40, so in this case, the spiral spring 42 can be omitted. can do. In addition, as means for imparting resistance to the relative rotation of the clutch cone with respect to the hub shaft, there are various other means such as filling the gap between the clutch cone 14 and the hub shaft 15 with a resin friction block (not shown). is possible. It should be noted that one or both of the threaded portion of the clutch cone 14 and the screw shaft portion 13 of the drive body may be coated with a fluororesin coating to reduce frictional resistance in order to smooth the feeding of the clutch cone 14. It is preferable to take the following measures. Next, the operation of this embodiment will be explained. It is assumed that a chain C is attached to a pair of freewheels 2 and 3 attached to a driving body 12, similar to the bicycle schematically shown in FIG. When the pedal is pedaled in the forward direction, the outer freewheel 2 rotates the drive body 12 in the forward direction. At this time, the inner freewheel 3 freely rotates in the opposite direction and generates a ratcheting sound. When the drive body 12 rotates in the forward direction, the clutch cone 14 is difficult to rotate relative to the hub shaft 15, so the drive body 12 does not rotate.
The clutch is fed to the feed screw 13 and moves in the direction of arrow P in FIG. When the clutch outer surface 33 joins the clutch inner surface 31, the clutch cone 14 cannot move any further in the direction of arrow P, so it begins to rotate together with the drive body 12, and the normal rotation of the drive body 12 is transmitted to the hub body 11. be done. Therefore, the force of pedaling is transmitted to the forward rotation of the hub body 11, and the bicycle moves forward. The joined state of the clutch outer surface 33 and the clutch inner surface 31 at this time is shown in FIG. 5a. At this time, since the engaging protrusions 30 and 32 on both clutch surfaces engage with each other, there is no relative slippage at all, and therefore the rotational driving force of the drive body 12 is reliably transmitted to the hub body 11. It is possible. When the pedal is pedaled in the reverse direction, the inner freewheel 3 rotates in the normal direction, which causes the driving body 12 to rotate in the normal direction.
At this time, the outer freewheel 2 rotates freely in the opposite direction, generating ratcheting noise. In this case as well, the drive body 12 is driven to rotate in the normal direction, so the hub body 11 is rotated in the normal direction in the same manner as described above.
However, in the illustrated example, the outer freewheel 2
Since the freewheel 3 has a larger diameter than the inner freewheel 3, a larger force can be transmitted to the hub body 11 when the pedals are pedaled in the forward direction. On the other hand, when the pedal rotation is stopped while the vehicle is running, the rotation of the driving body 12 is also stopped. However, since the bicycle is traveling forward due to inertia, the hub body 11 is rotating in the forward direction. The clutch cone 12 is forcibly rotated in the forward direction as the engaging protrusion 32 on the outer surface 33 of the clutch is hooked on the engaging protrusion 30 on the inner surface 31 of the clutch on the hub body 11 side. 13 in the direction of arrow Q in FIG. The situation at this time is shown in FIGS. 5b and 5c. This clutch cone 12 is to some extent arrow Q
As the clutches are moved in the direction, both clutch surfaces 3
The protrusions 31 and 32 of 1 and 33 are no longer caught, and the connection between the hub body 11 and the clutch cone 14 or the drive body 12 is completely cut off, so that the hub body 11 can move not only in the forward direction but also in the reverse direction. It will also be possible to rotate freely. This means that it is possible to coast the bicycle with the pedals stopped, and it is also possible to back the bicycle. It was previously explained that in the bicycle shown in FIG. 1, the driver 12 cannot be reversed. Therefore, when the hub body 11 is reversed in the case of backing up, etc., the reverse rotation of the hub body 11 must not be inadvertently transmitted to the clutch cone or the drive body 12. It will be understood. In the present invention, the engaging protrusions 30, 3 of both clutch surfaces 31, 33
By making the top part 2 have a smooth shape, the above-mentioned inconveniences can be effectively avoided. That is, clutch cone 14
When it is hooked to the engaging protrusion 30 of the hub body 11 and rotated as described above, Q until the possibility of it being caught on the engaging protrusion 30 is completely eliminated due to its own inertial rotation. Shift in direction. Then, from this state, Clutchcorn 14
Even if some kind of external force is applied to the handlebars, causing them to return slightly in the direction of arrow P, and the tops of both engaging protrusions 30 and 32 come into contact with each other, the tops of these engaging protrusions will remain in a smooth shape. Therefore, mutual engagement does not occur, and the reversing force of the hub body 11 is not transmitted to the clutch cone 14. Note that even if the clutch cone 14 is not particularly biased in the direction of arrow Q in FIG. 2 as in this embodiment, both engaging projections 30,
Just by making the top of 32 smooth,
When the hub body 11 is reversed, both engaging protrusions 3
Needless to say, it is possible to avoid careless multiplication of 0 and 32. As explained above, the clutch device of the present invention allows the hub body to freely rotate in both forward and reverse directions when the drive body is stopped, and when the drive body rotates forward, the clutch device reliably transfers the driving force to the hub body when the drive body is stopped. Since it can be transmitted to the body, it can be applied, for example, as a clutch for use in a bicycle hub as shown in FIG. Further, the present invention provides the first
If used as a one-way transmission clutch in the hub of not only a special bicycle as shown in the figure but also a normal bicycle, the conventional freewheel equipped with a ratchet mechanism can be omitted. Also in this case, since the pedals do not rotate in the opposite direction when backing up the bicycle, it is convenient to pull out one's own bicycle from a bicycle parking lot where neighboring bicycles are parked closely on the left and right. Furthermore, the clutch device of the present invention can of course be used in place of a cone clutch in a hub with a coaster brake, which transmits the rotational force of the driving body to the hub body and releases the transmission of the driving force. .

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of the drive unit of an example of a bicycle to which the clutch device of the present invention is advantageously applied;
The figure is a longitudinal sectional view of one embodiment of the present invention, and FIG.
Fig. 2 is a perspective view showing the components in an exploded state; Fig. 4a is a partial sectional view of the clutch cone; Fig. 4b is a partial sectional view of the hub body; Fig. 4c
5A is a partial sectional view of the driving body, FIG. 5A is a sectional view taken along the - line in FIG. 2, and FIG. 5B corresponds to FIG. Figures 6a, 6b and 6c are detailed views of the inner and outer surfaces of the clutch and their functions. DESCRIPTION OF SYMBOLS 11... Hub body, 12... Drive body, 13... Screw shaft part, 14... Clutch cone, 15... Hub shaft, 30... Engagement protrusion, 31... Clutch inner surface,
32... Engagement protrusion, 33... Clutch outer surface.

Claims (1)

[Claims] 1. A hub axle; rotatably supported at one end of the hub axle;
A drive body having a sprocket on the outside and a screw shaft on the inside; a drive body rotatably supported on the inner circumference of both ends by the other end of the hub shaft and the outer periphery of the drive body; A hub body has a conical inner surface of the clutch whose diameter increases inwardly, and the helical shaft is connected to the helical shaft when the helical shaft rotates in the normal direction, that is, when the helical shaft rotates the drive body to which the driving force is transmitted. a clutch cone having a conical outer surface that is screwed so as to be threaded toward the inner surface of the clutch when the clutch rotates in the same direction as the clutch cone, and that has a conical outer surface that can be tightly joined to the inner surface of the clutch; A unit hub or a hub with a coaster brake, etc., characterized in that both the inner surface of the clutch of the hub body and the outer surface of the clutch of the clutch cone are provided with engaging protrusions having smooth tops that can engage with each other. Clutch device for unit hubs or hubs with coaster brakes, etc.