JPH0140795Y2 - - Google Patents

Description

[Detailed description of the invention] (Technical field) The invention consists of an internal transmission with a coaster brake,
Specifically, between a gear frame and a hub shell that are interlocked with a ring gear having a high-speed transmission pawl via a planetary gear, there is provided a low-speed transmission body that transmits power to the hub shell when the gear frame rotates in the forward direction, and a low-speed transmission body that operates to transmit power to the hub shell when the gear frame rotates in the forward direction. The present invention relates to an internal transmission with a coaster brake, which is provided with a brake roller that performs a braking action on the hub shell during reverse rotation.

(Prior technology) Conventionally, as a coaster brake,
As shown in Publication No. 33277, a roller-shaped transmission body and a brake roller held by a holding cylinder are disposed between the drive body and the hub shell, and the drive body is provided with a brake roller when the drive body rotates in the normal direction. It is known to include a cam surface that presses the transmission body against the hub shell to interlock it, and a cam surface that displaces the brake roller toward the hub shell when the drive body rotates in reverse.

When the coaster brake is incorporated into an internal transmission, both cam surfaces are provided on a gear frame driven by a drive body, and these cam surfaces actuate the roller-shaped transmission body and the brake roller relative to the hub shell. Then, when driving at high speed,
Driving force is transmitted from a planetary gear provided in the gear frame to the hub shell via a high-speed transmission pawl of a ring gear, and during low-speed operation, the driving force is transmitted from the ring gear via the planetary gear and through the gear frame. , the power is transmitted from the transmission body to the hub shell.

However, when the bicycle is moved backwards, the reverse rotation of the hub shell is transmitted from the ring gear to the gear frame via the medium and high-speed transmission claws, and the gear frame rotates in reverse. According to
There has been a problem in that the brake roller performs a braking action on the hub shell on the cam surface, causing the bicycle to stop moving backward.

Therefore, in order to solve this problem, the roller-shaped transmission body is pressed against the hub shell even when the gear frame is rotated in reverse, so that the transmission body is interlocked with the hub shell when the bicycle is moving backward, Therefore, it is conceivable to eliminate the transmission of reverse rotational force from the medium/high speed transmission pawl to the gear frame so that the brake roller is in a non-operating state with respect to the hub shell.

However, when riding a bicycle, I stopped pedaling,
Even when the hub shell is in a state of free rotation, the transmission body is always in contact with the hub shell, and a contact load due to the interlocking of the transmission body is applied to the hub shell, resulting in a problem that the free rotation of the hub shell becomes heavy.

Therefore, in order to solve the above problem, as shown in the above-mentioned publication, a transmission pawl is used instead of the roller-shaped transmission body, the transmission pawl is held on the drive body, and the transmission pawl is held on the hub shell. It is conceivable to provide a ratchet with which the engaging pawl engages to transmit power to the hub shell when the driving body rotates in the normal direction.

However, in this case, when a forward rotational force is applied to the driving body with the braking roller operating in pressure contact with the hub shell, the transmission pawl is in a state where it is just meshed with the ratchet without any play. , there is a problem that the brake roller cannot operate to separate from the hub shell and becomes locked,
Fundamentally, it cannot be solved.

(Purpose of the invention) The object of the invention is to use a transmission pawl as a low-speed transmission body that transmits driving force from a gear frame to a hub shell, to hold the transmission pawl in a holding cylinder of a brake roller, and to hold the transmission pawl in a holding cylinder of a brake roller. The gear frame supports the gear frame so that they can rotate relative to each other within a certain range, and when the brake roller is pressed against the hub shell and is driven in the forward rotation direction, the brake roller is always reliably released from the hub shell. When you drive your bicycle backwards while shifting at medium or high speeds,
To provide an internal transmission with a coaster brake that can hold a brake roller in a non-operating state relative to a hub shell, ensure that the bicycle can be driven backwards, and that can lighten the free rotation of the hub shell when pedaling is stopped while riding the bicycle. be.

(Structure of the invention) The structure of the invention has a planetary gear between a gear frame interlocked with a ring gear having a high-speed transmission claw via the planetary gear and the inner peripheral surface side of the hub shell, when the gear frame is reversed. A braking roller that is displaced toward the inner circumferential surface of the hub shell is provided, and a holding cylinder that holds the roller is supported so as to be rotatable relative to the gear frame within a certain range. Holds the low-speed transmission claw that transmits power,
When the brake roller is driven in the forward direction while being in pressure contact with the hub shell, the brake roller can be operated to separate from the hub shell regardless of the engagement state of the low-speed transmission pawl with the hub shell. It is something.

(Example) Hereinafter, an example of the present invention will be described based on the drawings.

The one shown in Fig. 1 is intended to be applied to an internal bicycle transmission that performs three-stage shifting of high speed, medium speed, and low speed, and its basic structure consists of a drive body 1 and a a ring gear 3 having a first high-speed transmission pawl D ₁ that rotates and transmits transmission to the hub shell 2;
a gear frame 5 having a planetary gear G ₂ that meshes with the inner teeth 31 of the ring gear 3 and the sun gear G ₁ of the hub shaft 4, and a gear frame 5 having a low-speed transmission pawl D ₂ that transmits transmission to the hub shell 2; 4, a second rotary member that rotates in conjunction with the drive body 1 and transmits power to the gear frame 5;
A relay body 6 having a high-speed transmission pawl D ₃ is slidably supported, and the first and second high-speed transmission pawls D ₁ ,
An operating means 7 is provided which can switch D ₃ between a transmission state and a non-transmission state to change the speed between high speed, medium speed and low speed. Further, the driving body 1 is provided with a braking pawl _D4 that transmits the force to the ring gear 3 when the driving body 1 rotates in reverse, so that the reverse rotational force of the driving body 1 is transferred from the ring gear 3 to the gear via the planetary gear _G2 . The power is transmitted to the frame 5 to rotate the gear frame 5 in the reverse direction. A coaster brake 8 is provided between the gear frame 5 and the hub shell 2, and the low speed transmission body D ₂ and the coaster brake 8 are connected to the hub shell 2.
It is intended to operate reversibly by rotating the driving body 1 in the forward and reverse directions.

Specifically, on one side of the hub shaft 4, the driving body 1 having a chain gear _G3 is pivotally supported via a bearing _B1 , and the hub shell 2 is connected to the driving body 1 and the hub shaft. 4.The other side of the bearing
It is pivotally supported via B ₂ and B ₃ .

Then, in the hub shell 2, the relay body 6 is fitted into the drive body 1 side of the hub axle 4 so as to be freely rotatable and freely movable in the axial direction, and the gear frame 5 is relayed to the drive body 1. The ring gear 3 is fitted into the opposite side of the body 6 so as to be rotatable and immovable in the axial direction, and the ring gear 3 is fitted along the inner surface of the hub shell 2.
It is freely rotatably arranged from the drive body 1 side, through the relay body 6, and around one side of the gear frame 5.

The drive body 1 has a transmission body (not shown) that meshes with the ring gear 3 to transmit driving force when the drive body 1 is driven in the forward direction, and a transmission body (not shown) that meshes with the ring gear 3 when the drive body 1 is driven in the reverse direction. The braking pawl transmits driving force by
D ₄ is provided in the circumferential direction and is spline-coupled to the relay body 6 so that driving force can be transmitted at all times.

Further, the ring gear 3 has the inner teeth 31 formed on the inner surface on the gear frame 5 side, and on the drive body 1 side, the first high speed transmission claw
A ratchet R ₁ is provided on the opposing inner surface of the hub shell ₂ to support the transmission pawl D ₁ and engage the transmission pawl D ₁ in the upright position to transmit driving force to the ring gear 2. A biasing claw spring 3b is provided.

Further, the gear frame 5 is provided with a large diameter portion that is enlarged with respect to the hub shaft 4 on the ring gear 3 side, and this large diameter portion is fitted into the ring gear 3 up to the inner part of the inner surface teeth 31. A ratchet _R2 for the second high-speed transmission pawl _D3 is formed on the inner surface on the tip side of the large diameter portion.

Further, the sun gear _G1 is formed on the hub shaft 4 corresponding to the base side of the large diameter portion of the gear frame 5, and the sun gear G1 is connected to the large diameter portion of the gear frame 5 via a pivot 5a. ₁ and the planetary gear _G2 meshing with the inner teeth 31 of the hub shell 2.

Next, the relay body 6 is provided with a large diameter portion that is enlarged with respect to the hub shaft 4 on the gear frame 5 side, and the large diameter portion is attached to the hub shaft on the large diameter tip side in the gear frame 5. The second high-speed transmission pawl D can be fitted freely in four directions, and at this fitting portion, the second high-speed transmission pawl D can be freely engaged with and disengaged from the ratchet _R2 formed on the tip side of the inner surface of the gear frame 5 by the pawl shaft 6a. A pawl spring 6b is provided which supports the transmission pawl _D2 and biases the transmission pawl _D2 in the upright direction.

The operating means 7 includes an operating rod 71 that is inserted from the left side of the hub shaft 4 to actuate the actuating body 7a in the axial direction, as shown in FIG.
1 from the state shown in the figure to the right, the second
The first and second clutches C 1 and C _{2 sequentially} operate the high-speed transmission pawl D ₃ and the first high-speed transmission pawl D ₁ to fall down, and the relay body 6 is connected to the first clutch C ₁ and the hub shaft on the driving body 1 side. 4, and a spring 72 which is elastically supported between the operating rod ₇₁ and the operating rod ₇₁ from the state shown in FIG. By operating the gear in the prone position, the gears can be changed to high speed, medium speed, and low speed, respectively.

Then, when the driving body 1 is rotated in the reverse direction with the speed changed to high speed, medium speed, and low speed as described above,
Even in high speed, medium speed and low speed conditions, the reverse rotational force is transmitted to the gear frame 5 through the ring gear 3.
With the reverse rotation of the gear frame 5, the low speed transmission body is transmitted to the hub shell 2 as described later.
_D2 becomes inactive, and the coaster brake 8 is switched to an active state.

Therefore, the present invention basically provides a coaster which is disposed between the gear frame 5 and the inner circumferential surface of the hub shell 2 and which is displaced toward the inner circumferential surface of the hub shell 2 when the gear frame 5 is reversed. A braking roller 81 of the brake 8 is provided, and a holding cylinder 82 holding the braking roller 81 is supported so as to be rotatable relative to the gear frame 5 within a certain range.
A pawl is used as D ₂ (hereinafter referred to as low-speed transmission pawl D ₂ ), and this low-speed transmission pawl D ₂ is held in the holding cylinder 82 .

The coaster brake 8 shown in FIG.
The bearing B ₃ provided on one side of the hub shell 2 is supported on the hub axle 4 by a brake cone 83, and a second and second bearing B ₃ is provided between the hub shell 2 and the brake roller 81 inside the bearing B 3 As shown in Fig. 3, brake shoes 84 are arranged such that a pair of semi-cylindrical shoes are cylindrically opposed to each other so that the diameter can expand freely, and the brake shoes 84 are biased in the direction of semi-radial expansion by a spring 85. One side of the brake shoe 84 is non-rotatably engaged with the brake cone 83.

Then, when the gear frame 5 rotates in reverse (in the direction of the arrow in FIG. 3), the brake roller 81 is brought close to the corresponding part of the brake roller 81 in the gear frame 5 with respect to the inner peripheral surface of the hub shell 2, The cam surface 5 is also non-approachable during forward rotation (in the direction of the arrow in Figure 2).
1, and the brake roller 81 is interposed between the cam surface 51 and the inner circumferential surface of the brake shoe 84 so as to be clamped by the spring 85. Further, the holding cylinder 82 of the brake roller 81 is
As shown in FIGS. 2 and 3, a plurality of teeth a, for example, five teeth a, are provided around the axially intermediate portion of the inner peripheral surface at equal intervals, and the gear frame 5 is provided with a plurality of teeth a, for example, five teeth a.
Teeth b... that engage freely over a certain range between a are provided at regular intervals, and a holding portion 82a of the brake roller 81 is provided on one side of this holding cylinder 82, and a holding portion 82a of the brake roller 81 is provided on the other side. Raise the low speed transmission claw _D2 ,
A concave support portion 82b is formed to support the folding operation. The low-speed transmission pawl D ₂ is supported on this support portion 82b, and biased in the upright direction by the spring 5b.
A ratchet R3 is formed on the inner surface of the hub shell 2 corresponding to _D2 , with which the low speed transmission pawl _D2 engages when raised, and _the low speed transmission pawl _D2 is connected to the ratchet _R3 .
The gear frame 5 is engaged with the hub shell 2 during forward rotation, and is engaged and disengaged during reverse rotation.

However, in the above configuration, the driving body 1
When operating with forward rotation, the gear frame 5
Regardless of the gear shifting state, the hub shell 2
The brake roller 81 is rotated in the same direction as the cam surface 51 and in the opposite direction of the arrow, and the brake roller 81 is held at a position where the cam surface 51 does not approach the brake shoe 84. As a result, the brake shoe 84 ,
It is in an inoperative state where it is separated from the inner circumferential surface of the hub shell 2. At this time, the holding cylinder 8
2, the teeth a and b mesh with each other with respect to the gear frame 5, so that the low speed transmission pawl _D2 becomes a ratchet.
In contrast to R ₃ , the hub shell 2 engages and disengages from the gear frame 5 during high-speed and medium-speed shifts due to high-speed rotation, and engages with and drives during low-speed shifts.

In the above operation, when the driving body 1 is rotated in the reverse direction, the gear frame 5 is rotated in the clockwise direction of the arrow shown in FIG. 3, which is the opposite direction to the hub shell 2, regardless of the speed change state. , the brake roller 81 is connected to the brake shoe 84 on the cam surface 51.
As a result, the brake shoe 84 is brought into pressure contact with the inner peripheral surface of the hub shell 2. At this time, the holding cylinder 82 reversely rotates with a slight delay with respect to the gear frame 5, and as a result, the teeth a of the holding cylinder 82 rotate in the reverse direction from the meshing position with the teeth b of the gear frame 5, as shown in FIG. The low speed transmission pawl _D2 supported by the holding cylinder 82 engages and disengages from the ratchet _R3 which rotates in the forward direction.

Next, when the bicycle is moved backwards, the reverse rotation of the hub shell ₂ transfers the planetary gear G 2 from the ring gear ₃ in the high-speed and medium-speed shifting states in which the first high-speed transmission pawl D 1 is engaged with the ratchet R ₁ . Although the speed is transmitted to the gear frame 5 through the gear frame 5 to operate the coaster brake 8, the reverse rotation of the hub shell 2 causes the low speed transmission pawl _D2 to act on the coaster brake 8.
The transmission is then transmitted to the gear frame 5 through the holding cylinder 82 without being decelerated, thereby destroying the transmission function of the first high-speed transmission pawl _D1 . As a result, the gear frame 5
The cam surface 51 acts on the hub shell 2 via the braking roller 81 so that the brake shoe 84 is inactive against the hub shell 2, and the brake shoe 84 is activated on the hub shell 2 as shown in FIG. Even in this state, by applying a backward force to the bicycle, the brake shoe 84 is separated from the hub shell 2, and the bicycle can be moved backward.

Furthermore, when a positive rotational force is applied to the driving body 1 with the coaster brake 8 in operation as shown in FIG. , said low speed transmission claw D ₂
When the brake shoe ₈₄ is in a locked state in which the brake shoe 84 remains in pressure contact with the hub shell 2, as shown in FIG. Therefore, the gear frame 5 can rotate forward until the teeth a and b mesh with the holding cylinder 82, and this forward rotation allows the brake shoe 84 to be reliably separated from the hub shell 2, allowing operation to resume. It is.

In the above description, the present invention was intended to be applied to a three-speed transmission, but it goes without saying that it is also applicable to a two-speed transmission, high speed and low speed.

(Effects of the invention) As described above, according to the invention, by using the transmission pawl as a low-speed transmission body that transmits driving force from the gear frame to the hub shell, when the bicycle is moving backwards, the reverse rotation of the hub shell transfers the low-speed transmission pawl to the hub shell. As a result, the high-speed transmission pawl is in a non-transmission state in which it engages and disengages from the hub shell. Therefore, it is possible to reliably prevent the brake shoe from operating on the hub shell, and the bicycle can be operated without any trouble. Moreover, when pedaling is stopped while riding the bicycle, the free-rotating hub shell becomes in an unloaded state because the low-speed transmission pawl is disengaged, and the free rotation can be reduced.

In addition, since the holding tube that holds the low-speed transmission pawl is supported so that it can rotate relative to the gear frame within a certain range, when a forward rotational force is applied to a bicycle that is stopped in a braking state where the brake shoe is in pressure contact with the hub shell. The gear frame to which this forward rotational force is transmitted can rotate forward with respect to the holding cylinder regardless of the engagement state of the low-speed transmission claw with the hub shell, and this forward rotation causes the brake shoe to be separated from the hub shell, thereby preventing any trouble. You can resume riding your bicycle without any problems.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; FIG. 1 is an explanatory cross-sectional view, FIGS. 2 and 3 are cross-sectional views taken along line X-X in FIG. 1, and FIG. FIG. 3 shows a state in which the driver is rotated in the opposite direction and the brake is activated. 2...Hub shell, 3...Ring gear, 5...
Gear frame, 81...braking roller, 82...holding cylinder,
G ₂ ... Planetary gear, D ₁ ... High speed transmission pawl, D ₂ ... Low speed transmission pawl.

Claims (1)

[Scope of utility model registration request] A braking roller is provided between a gear frame having a planetary gear and interlocking with a ring gear having a high-speed transmission pawl via the planetary gear and the inner circumferential surface of the hub shell, and which is displaced toward the inner circumferential surface of the hub shell when the gear frame is reversed. At the same time, a holding cylinder that holds the roller is supported so as to be rotatable relative to the gear frame within a certain range, and the holding cylinder holds a low-speed transmission claw that transmits power from the gear frame to the hub shell. An internal transmission with a coaster brake featuring: