JPS6224637Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an automatic transmission device for a bicycle. In more detail, the chain is automatically changed according to the bicycle's running speed, and the gears arranged in multiple gears are changed according to the number of gears, and the changing operation at each stage is changed depending on the slight change in speed. This invention relates to an automatic transmission device for a bicycle that can securely maintain gears in each gear without unexpectedly or unintentionally shifting.

Conventionally, various transmission devices have been considered to change the gear ratio of a bicycle and obtain a gear ratio suitable for the running speed, but they can be roughly divided into multiple transmission devices arranged on the rotating shaft of the wheel corresponding to the number of gears. Two types of transmissions have been implemented: a manual stepped transmission in which the chain is changed between gears by operating a manual lever, and an automatic continuously variable transmission in which the gear changes automatically and steplessly in response to the bicycle's running speed. However, each of the above two types of transmission devices has advantages and disadvantages as listed below. In other words, the former type of manual stepped transmission has a simple mechanism and has the advantage of being operated by the driver himself, but if he operates it himself, he must operate with one hand while driving, and it is necessary to select when to operate the lever. When stopping normally, the vehicle often stops without changing gears. However, this gear change can only be done while the bicycle is running, so when starting, the bicycle must be started in the high gear that was used for high-speed riding before stopping, which requires strong force. It is. In particular, starting up an uphill slope was often extremely difficult. Therefore, automatic gear shifting has been considered as a means of resolving the problems of manual gear shifting systems. However, when the gears are automatically changed according to the driving speed, the gears are continuously variable. This has the advantage that the optimum gear ratio can always be obtained because the gear ratio suitable for the traveling speed is automatically changed, but it has the disadvantage that the structure becomes complicated and expensive.

The present invention was developed in view of the above-mentioned points, and its gist is that the chain corresponds to the running speed of the bicycle, and the number of gears arranged coaxially with the rotation axis of the wheel corresponds to the number of gears. In a bicycle equipped with a transmission that sequentially changes gears by operating levers on multiple gears, there is a vehicle speed detecting means for detecting the speed of the bicycle, and a speed detecting means that is driven by the rotational force of the vehicle speed detecting means and is proportional to the number of rotations. a hydraulic pump that generates a discharge amount, a piston cylinder having a piston that moves forward and backward according to the discharge amount of the hydraulic pump; An automatic transmission device for a bicycle consisting of a gear switching section that slides and maintains its forward and backward positions, and a gear changing device that is connected to the gear switching section via a wire, and its intended purpose. The mechanism is simple and can be manufactured at low cost, and the chain can be automatically changed to a gear appropriate for the vehicle speed. Furthermore, it can be easily applied to bicycles that have an off-the-shelf chain changing device that allows gears to be changed by manually operating a lever. To provide an automatic transmission device for a bicycle which can be attached, which can reliably switch between gears, and which can be firmly held after switching.

Next, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

In the figure, 1 is the bicycle body, and the rotating shaft 3 of the rear wheel 2 has three gears 4a, 4b, 4 with different numbers of teeth.
c is installed. A chain 6 for transmitting the rotational force of the pedal 5 is changed over the three gears 4a, 4b, and 4c by a changing means 10 comprising a chain guide 7, a spring 8, and a wire 9. Conventionally, the chain guide 7 is positioned by pulling or loosening the wire 9 using a lever (not shown), and the chain 6 is changed to the gears 4a, 4b, 4c. The chain 6 is connected to the gears 4a, 4b, 4 according to the running speed of the bicycle.
It is configured as follows so that it can be automatically replaced with c. That is, the speed of the bicycle body 1 is detected by the vehicle speed detection means 11. This vehicle speed detecting means 11 has a rotating gear 11a that rotates together with the rear wheel 2 on the rotating shaft 3 of the rear wheel 2, and a detection gear 11b is meshed with the rotating gear 11a to increase the rotational speed of the rotating gear 11a. It is designed to detect. Next, 12 is a hydraulic pump, and the drive shaft 12a of the hydraulic pump 12 and the detection gear 11b are connected via a flexible shaft 13. This hydraulic pump 12 is connected to a piston cylinder 14 through a tube 15, and the oil O pressurized by the hydraulic pump 12 is
pushes the piston 16 of the piston cylinder 14 in the direction of arrow A in FIG. 2 through this tube 15. On the other hand, the piston 16 is pressed by the spring 8 in the direction of arrow B in FIG. Further, the inner wall 17 of the piston cylinder 14 is formed in a stepped shape, the number of which corresponds to the number of gears. The oil O sent from the hydraulic pump 12 to this cylinder 14 is applied to the pressure receiving plate 16a of the piston 16 and the stepped inner walls 17a, 17b, 1.
7c, and then through the tube 15 disposed at the rear of the cylinder to the oil tank 12.
It returns to Next, 18 is the piston 1
6, and pin holes 19a, 19b, 19c are formed along the sliding direction on its circumferential surface in a number corresponding to the number of gears. A pin 20 is pushed upwardly in FIG. 2 by a spring 21 so that it is selectively fitted into one of these pin holes 19a, 19b, and 19c within a range that allows sliding of the actuating rod 18. It is arranged while being energized by. A support base 22 accommodates the pin 20 and spring 21 in a housing groove 22a so as to be vertically movable, and supports the actuation rod 18 so as to be slidable in the directions of arrows A and B in FIG. The above operating rod 18, pin holes 19a, 19
b, 19c, the pin 20, the spring 21, and the support base 22 constitute a gear switching section 23, and the gear switching section 23 changes the forward and backward movement of the piston 16 into the gears in a stepwise manner for each predetermined range of the number of gears. The information is transmitted to the changing device 10. This gear switching portion 23 allows the pin 20 to fit into any of the pin holes 19a, 19b, and 19c while being biased by the spring 21 when the forward and backward force of the piston 16 fluctuates somewhat around the gear switching speed. The resulting engagement force suppresses this slight variation and prevents unexpected gear changes. A transmission rod 24 is connected to the rear of the operating rod 18.
The transmission rod 24 is connected to a bifurcated portion of the crank 25 by an engagement pin 26. Next, the other end 25a of the crank 25 and the chain guide 7 are connected by the wire 9.

Next, the operation will be explained based on the above configuration.

First, a state in which the bicycle main body 1 is stopped will be explained. In this stopped state, the rotary gear 11a of the vehicle speed detection means 11 is not rotating, so pressurized oil O is not sent from the hydraulic pump 12 to the piston cylinder 14. For that purpose piston 16
and the actuating rod 18 is moved to the second position by the spring 8.
The pin 20 is pushed fully in the direction of arrow B in the figure, and is in a position where it is fitted into the pin hole 19a as previously set. Therefore, since the transmission rod 24 is moving in the direction of arrow B in FIG.
is fully rotated in the direction of arrow C in FIG. For this reason, the chain guide 7 is pressed in the direction of arrow R in FIG. 3, and the chain 6 is applied to the gear 4a having the largest number of teeth. That is, when the bicycle main body 1 is in a stopped state, the chain 6 is always engaged with the gear 4a having the largest number of teeth, as in the conventional case. Next, when this bicycle starts, the rotating gear 11a disposed on the rotating shaft 3 of the rear wheel 2 is rotated, and the torque of this rotating gear 11a is detected by the detection gear 11b.
The drive shaft 12a of the hydraulic pump 12, which is connected via the flexible shaft 13, is rotated to operate the hydraulic pump 12. Oil O pressurized by this hydraulic pump 12 is sent to the piston cylinder 14 through the tube 15. The oil O sent to the piston cylinder 14 passes through the gap between the pressure receiving plate 16a and the inner wall 17a of the piston cylinder 14 while pressing the pressure receiving plate 16a of the piston in the direction of arrow A in FIG. The oil tank 1 is then passed through the return tube 15 installed at the rear of the oil tank 1.
Return to 2b. The amount of oil O sent to the piston cylinder 14 is proportional to the rotation speed of the drive shaft 12, that is, the rotation speed of the rotating gear 11a. For this reason, as the speed of the bicycle body 1 increases, the hydraulic pump 1
The amount of oil O sent from 2 to the hydraulic cylinder 14 also increases. As the inflow of oil O increases, the pressure receiving plate 1
6a and the inner wall 17a of the piston cylinder, so at this time, the pressure receiving plate 16a and the piston 16 overcome the pressing force of the spring 8 and the engaging force of the pin 20 fitted in the pin hole 19a. Move in the direction of arrow A in Figure 2. That is, the pressure receiving plate 16a resists the force of the spring 8.
the piston 16 to a position where it corresponds to the inner wall 17b.
is moved in the direction of arrow A in FIG.
6a and the inner wall 17b are balanced, the movement of the pressure receiving plate 16a and the piston 16 is stopped, and the stopped state is achieved when the pin 20 is fitted into the pin hole 19b of the actuating rod 18 according to a predetermined setting. It is maintained by matching. As mentioned above, the pressure receiving plate 16a, the piston 16 and the actuating rod 18
When the transmission rod 24 moves by the distance a between the pin holes 19a and 19b, the transmission rod 24 also moves by the same distance a. Therefore, the crank 25 rotates by an angle θ ₁ in the direction of arrow D in FIG. Through this rotation, the crank 25 extends the wire 9 connected to the other end 25a by the length c between the gear 4a with the largest number of teeth and the next gear 4b as shown in FIG. Pull in the direction of the middle arrow L to move the chain guide 7 onto the axis of the gear 4b. In this way, the chain guide 7 is moved from the axis of the gear 4a to the gear 4a.
By moving the chain 6 onto the axis b, the chain 6 is changed from the gear 4a to the gear 4b. That is, as the speed of the bicycle main body 1 increases, the gear changes from a gear 4a for low-speed traveling to a gear 4b for medium-speed traveling.
This means that the change was automatically made. Then, when the speed of the bicycle body 1 increases further,
The discharge amount of the hydraulic pump 12 also increases proportionally. For this reason, the amount of oil flowing into the hydraulic cylinder 14 exceeds the amount of oil flowing out from the gap between the pressure receiving plate 16a and the inner wall 17b, and at that point, as described above,
Overcoming the pressing force of the spring 8 and the engaging force of the pin 20 fitted into the pin hole 19b, the pressure receiving plate 16
a and the piston 16 are further moved in the direction of arrow A in FIG. That is, the piston 16 is moved against the force of the spring 8 to a position where the pressure receiving plate 16a corresponds to the inner wall 17c, and as described above, at this position, the amount of oil flowing into the hydraulic cylinder 14 and the pressure receiving plate 16 and the inner wall are The amount of flow flowing out through the gap between the pistons 17c is balanced, and the movement of the piston 16 is stopped, and as predetermined, the stopped state is achieved by fitting the pin 20 into the pin hole 19c of the actuating rod 18. Retained. At this time, the chain 6 is switched from the gear 4b for medium speed travel to the gear 4c for high speed travel. Next, when the bicycle body 1 decelerates, the discharge amount of the hydraulic pump 12 also decreases, so the piston 16 is moved in the direction of arrow B in FIG. 2 by the pressing force of the spring 8. Therefore, the chain 6 is replaced by an operation opposite to that when the bicycle body 1 is raised.

In this embodiment, a three-speed gear shift is described in detail, but it goes without saying that other gears can be used. In addition, the gear switching section 23 has pin holes 19a, 19
Although the pin 20 is fitted into one of the pistons 19b and 19c, it can slide stepwise in accordance with the number of gears as the piston 16 advances and retreats, and can maintain the advanced and retreated positions. It can also be used as a means of Furthermore, although the pump 12 and the piston cylinder 14 are shown as separate bodies, the objective effects of the present invention can be similarly achieved even if they are integrated.

As detailed above, the present invention allows the chain to be sequentially shifted to multiple gears corresponding to the number of gears, which are arranged coaxially with the rotating shaft of the wheel, by operating a lever in accordance with the running speed of the bicycle. A bicycle with a transmission includes a vehicle speed detecting means 11 for detecting the speed of the bicycle 1, and a hydraulic pump 12 that is driven by the rotational force of the vehicle speed detecting means 11 and generates a discharge amount proportional to its rotation speed. , the hydraulic pump 12
a piston cylinder 14 having a piston 16 that moves forward and backward according to the discharge amount of the piston 16; The bicycle automatic transmission device is composed of a gear switching section 23 for holding the gear switching section 23, and a gear changing device 10 connected to the gear switching section 23 via a wire 9, so the mechanism is simple and can be manufactured at low cost. Moreover, the chain is connected to a gear 4a for low-speed running and a gear 4 for medium-speed running, which are suitable for the running speed of the bicycle body 1.
b. It can be changed sequentially by the number of gears as the high-speed running gear 4c, and it can be easily installed on a bicycle that has an off-the-shelf chain changing device that changes gears by manually operating a lever; The present invention has various advantages, such as providing an automatic bicycle transmission device that can reliably shift gears and that can be held securely after shifting.

[Brief explanation of the drawing]

The accompanying drawings show an embodiment of the present invention, and FIG. 1 is a plan view, FIG. 2 is a system diagram of the transmission, and FIG. 3 is an explanatory diagram of the operation of the transmission. In the figure, 1...bicycle, 4a, 4b, 4c...
Gear, 6...Chain, 9...Wire, 10...
...Changing device, 11...Vehicle speed detection means, 11a
... Rotating gear, 12 ... Hydraulic pump, 14 ... Piston cylinder, 16 ... Piston, 18 ...
Actuation rods, 19a, 19b, 19c...pin holes, 20...pins are shown.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) In response to the running speed of the bicycle, the chain is sequentially moved to multiple gears corresponding to the number of gears disposed coaxially with the rotating shaft of the wheel by operating levers. In a bicycle with a transmission to be replaced, a vehicle speed detection means 11 for detecting the speed of the bicycle 1;
a hydraulic pump 12 that is driven by the rotational force of the vehicle speed detection means 11 and generates a discharge amount proportional to its rotational speed; a piston cylinder 14 having a piston 16 that moves forward and backward in accordance with the discharge amount of the hydraulic pump 12; A gear switching part 23 connected to the piston 16 and sliding in stages corresponding to the number of gears as the piston 16 advances and retreats, and for maintaining the advanced and retreated positions, and the gear switching part 23 and a wire. An automatic transmission device for a bicycle, characterized in that it comprises a gear changing device 10 connected via a gear shifter 9. (2) The gear changing section 23 consists of an actuating rod 18 having pin holes 19a, 19b, 19c formed at predetermined intervals equal to the number of gears along the sliding direction, and a piston 16. Insert the above operating rod 18 into one of the pin holes depending on the forward or backward movement.
The automatic transmission device for a bicycle according to claim 1, characterized in that the automatic transmission device for a bicycle is comprised of a pin 20 that engages within a range that allows sliding. (3) The vehicle speed detection means 11 is connected to the rotating shaft 3 of the rear wheel 2.
and a detection gear 11b for detecting the number of rotations of the rotating gear 11a.
An automatic transmission device for a bicycle according to claim 1, characterized in that it comprises the following.