Quadricycle

Abstract

To guarantee safety for fall protection, offer ease of pedaling, and stabilize a left and right balance and a forth and back balance.SOLUTION: A power-assisted quadricycle 1 includes two front wheels 42, two rear wheels 52, cranks 64a and 64b that transmit power to the rear wheels 52 and rotate about crank shafts, a seat 71 on which a driver is seated, and a hip support member 72 that supports the hip of the driver who is seated on the seat 71. A fore-and-aft direction distance L from the center of the crank shaft to the rearmost end of the seat is larger than a vertical direction distance H orthogonal to the fore-and-aft direction from the center of the crank shaft to a seat uppermost end.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an electrically assisted four-wheel bicycle that can be driven safely and securely by elderly people and the like. [Background technology]

[0002] Conventionally, there have been tricycle-type bicycles for the elderly, and more specifically, there are those with one front wheel and two rear wheels (one front wheel, two rear wheels) (see, for example, Patent Document 1), and those with two front wheels and one rear wheel (two front wheels, one rear wheel). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 9-263289 Summary of the Invention [Problem to be solved by the invention]

[0004] Generally, for electric tricycles, it is preferable to position the seat as low as possible so that the rider's legs can touch the ground, from the perspective of safety and preventing falls when used by elderly people, etc. However, in this case, the height distance between the pedals and the seat becomes small, which creates a problem in that the rider's legs cannot be extended when turning the pedals, making it difficult to pedal.

[0005] Therefore, for example, one possible method is to make the pedals easier to pedal by increasing the distance from the pedals to the seat in the front-to-back direction while shortening the distance from the pedals to the seat in the up-to-down direction.

[0006] However, in this case, the distance between the driver's body position and the steering wheel becomes large, which causes a new problem of unstable balance in the left-right and front-rear directions.

[0007] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a four-wheeled bicycle that is safe and prevents tipping over, is easy to pedal, and provides stable balance in the left-right and front-rear directions. [Means for solving the problem]

[0008] In order to achieve the above-mentioned object, the four-wheeled bicycle of the present invention comprises two front wheels, two rear wheels, a crank that rotates around a crankshaft and transmits power to the rear wheels, a seat for a rider, and a waist support member that supports the waist of the rider seated on the seat, and is characterized in that the front-to-rear distance L from the center of the crankshaft to the rearmost end of the seat is greater than the up-to-down distance H perpendicular to the front-to-rear direction from the center of the crankshaft to the topmost end of the seat.

[0009] the above H <L By doing this, even if the seat is lowered so that the rider's feet touch the ground, the pedals will not be too close in height to the seat, making pedaling difficult. However, in this case, the distance between the user's body and the handlebars will be too great, which can lead to unstable left-right and front-to-back balance. Therefore, in this invention, by using a four-wheeled bicycle instead of a three-wheeled bicycle and by providing a waist support member behind the seat, the above problem is solved, stabilizing left-right and front-to-back balance and enabling stable pedaling. Therefore, the four-wheeled bicycle of the present invention can prevent falls when used by elderly people and others, eliminates the difficulty of pedaling and makes it easier to start pedaling, and stabilizes the balance from side to side and front to back when riding and driving, allowing for safe and secure riding. [Effects of the Invention]

[0010] According to the present invention, it is possible to achieve safety in terms of preventing falls, ease of pedaling, and stable balance. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a front view of an electrically assisted tricycle showing an embodiment of the present invention. [Figure 2] FIG. 2 is a perspective view of a frame structure in the same embodiment. [Figure 3] FIG. 2 is a perspective view of a front wheel rocking mechanism in the embodiment. [Figure 4] FIG. 2 is an enlarged view of a battery mounting portion in the embodiment. [Figure 5] FIG. 4 is an enlarged view of a waist support portion in the same embodiment. [Figure 6] FIG. 2 is an enlarged view of a drive unit in the same embodiment. [Figure 7] FIG. 2 is an enlarged view of a differential gear portion in the same embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] An embodiment of the present invention will now be described with reference to the drawings. This embodiment is a four-wheeled bicycle that allows the frame to lean in a manner similar to that of a conventional two-wheeled bicycle, particularly when turning, and that makes it easier for elderly people who have difficulty riding conventional two-wheeled bicycles to start pedaling at low speeds.

[0013] In this embodiment, the four-wheel bicycle according to the present invention will be described using an example in which the four-wheel bicycle is an electrically assisted four-wheel bicycle, but the present invention can also be applied to a four-wheel bicycle without electrically assisted power.

[0014] In the following description, the left-right direction in FIGS. 1 and 2 is defined as the front-rear direction (horizontal direction), the up-down direction is defined as the up-down direction, the front in the drawings is defined as the right, and the back is defined as the left.

[0015] <Overall structure> The electrically assisted four-wheel bicycle 1 (four-wheel bicycle 1) mainly comprises a body frame 2, a front frame 3, a rear frame 4, two front wheels 42, two rear wheels 52, a handlebar 11, and a seat 71.

[0016] The front frame 3 has a front upper stay 22 and a front lower stay 23 .

[0017] The front upper stay 22 has a suspension bracket 31 at its front lower end. The suspension bracket 31 connects to a swing arm 41 at the center in the left-right direction so that it can swing left and right. The swing arm 41 rotatably supports a pair of left and right front wheels 42 via a pair of left and right knuckle arms 61a, 61b. The swing arm 41 slidably supports a pair of left and right dampers 43 (springs). That is, the dampers 43 are arranged on the left and right of the swing arm 41 to connect the suspension bracket 31 of the front frame 3 and the swing arm 41 so that it can tilt left and right.

[0018] The suspension bracket 31 supports a bearing 13 at the center position in the left-right direction, and the bearing 13 rotatably supports the steering shaft 12. The steering shaft 12 is also supported by an upper handle bracket 33 and a lower handle bracket 34 provided on the front upper stay 22. The steering shaft 12 has a handle 11 at its upper part. The handle 11 has brake levers 56a, 56b.

[0019] The steering shaft 12 is slidably supported by knuckle arms 61a, 61b via a tie rod 62. As a result, the operation of the steering wheel 11 is transmitted to the front wheels 42, and the steering shaft 12 steers the front wheels 42.

[0020] The brake levers 56a, 56b transmit the input braking operation to the front brake device 44 and the rear brake device 45. The front brake device 44 is attached to the knuckle arm 61b. The rear brake device 45 is attached to the axle housing 93 (FIG. 7).

[0021] A lock 78 for locking the electrically assisted four-wheel bicycle 1 is attached to a predetermined position on the steering shaft 12.

[0022] The front upper stay 22 has a front carrier 75. The front carrier 75 attaches a front basket 76 and a headlight 83 to the front upper stay 22. In particular, the front carrier 75 (front frame 3) supports the front basket 76 so that it is positioned above the center of rotation of the front wheel 42.

[0023] The front upper stay 22 has a battery stay 32 that supports a base battery 81a. The battery 81 drives the motor 21 that provides power for the electrically assisted four-wheel bicycle 1. In other words, the battery 81 is a driving battery that drives the rear wheel 52 via the cranks 64a, 64b. The battery 81 is detachable from the base battery 81a. As a result, when the electrically assisted four-wheel bicycle 1 is driven by the motor 21, the battery 81 is disposed between the steering shaft 12 and the crank shaft 65 and attached to the front upper stay 22.

[0024] The body frame 2 has a motor bracket 24, a seat tube 25, a seat bracket 35, and a rear pivot 36.

[0025] The motor bracket 24 mounts the motor 21 to the body frame 2 via bolts. The motor 21 is connected to the cranks 64a and 64b via the crankshaft 65, and rotates the cranks 64a and 64b. The motor 21 has a control function (not shown) that prevents the driving force of the rear wheel 52 from exceeding a set value.

[0026] The cranks 64a, 64b rotate around the crankshaft 65 and transmit power to the rear wheel 52. The cranks 64a, 64b have pedals 63a, 63b at their tips. The pedals 63a, 63b transmit rotational power from the rider to the cranks 64a, 64b. The cranks 64a, 64b are connected to the front sprocket 54.

[0027] The seat tube 25 has a front end that is roughly aligned vertically with the cranks 64a, 64b connected to the motor bracket 24, and a rear end that extends rearward and upward from the front end. The seat tube 25 (body frame 2) has a horizontal portion 25a that extends parallel to the front-to-rear direction between the crankshaft 65 and the seat 71. The horizontal portion 25a is a section of a fixed length extending from the front end to the rear end.

[0028] The seat bracket 35 is attached to the rear end of the seat tube 25. The seat bracket 35 attaches a rider seat (saddle) 71 and a lumbar support member 72 to the seat tube 25 via a seat frame 73. The seat frame 73 is fixed to the seat bracket 35 with bolts or the like via elongated holes that extend longitudinally in the front-to-rear direction. By fixing the seat frame 73 to the seat bracket 35 at a desired position in the elongated holes, the positions of the seat 71 and the lumbar support member 72 relative to the seat bracket 35 can be adjusted forward and backward.

[0029] Here, in the electrically assisted four-wheel bicycle 1 of this embodiment, as shown in Figure 1, the seat 71 and the body frame 2 are configured so that the longitudinal distance L from the center of the crankshaft 65 to the rearmost end of the seat 71 is greater than the vertical distance H, which is perpendicular to the longitudinal direction, from the center of the crankshaft 65 to the topmost end of the seat 71.

[0030] The rear pivot 36 connects the rear frame 4 to the body frame 2 .

[0031] The rear frame 4 supports a rear wheel 52 and a rear sprocket 53. The rear sprocket 53 is connected to the hub of the rear wheel 52.

[0032] Chains 55a, 55b are stretched between front sprocket 54 and rear sprocket 53. Chains 55a, 55b are connected by a counter sprocket 92. Chains 55a, 55b also have required chain tensioners 91a, 91b. Chains 55a, 55b transmit the resultant force of the rotational force input from the rider via pedals 63a, 63b and the rotational force input from motor 21 to rear wheel 52 via rear sprocket 53.

[0033] The rear wheels 52 are supported by the rear frame 4 via axle shafts 94. The axle shafts 94 are housed in axle housings 93. A differential gear 95 is attached to the middle portions of the left and right axle shafts 94.

[0034] <Effects of this embodiment> The present embodiment configured as above provides the following effects. That is, as shown in Figure 1, the electrically assisted four-wheel bicycle 1 is configured so that the longitudinal distance L from the center of the crankshaft 65 to the rearmost end of the seat 71 is greater than the vertical distance H from the center of the crankshaft 65 to the topmost end of the seat 71.

[0035] As a result, even if the position of the seat 71 is lowered so that the rider can sit with his / her feet on the ground, the distance between the pedals 63a, 63b and the seat 71 will not be too close, making it difficult to pedal.

[0036] Furthermore, if the longitudinal distance L is greater than the vertical distance H as described above, for example, depending on the rider's physique, the distance between the rider and the handlebars 11 may become too great, which could lead to unstable left-right and front-to-back balance. Therefore, in this embodiment, the bicycle 1 is configured as a four-wheeled bicycle 1 with four wheels rather than a three-wheeled bicycle, and by including a waist support member 72, the above problem is resolved, the left-right and front-to-back balance is stabilized, and stable pedaling is possible. Therefore, the four-wheeled bicycle 1 of the present invention can prevent falls when used by elderly people and others, eliminates the difficulty of pedaling and makes it easier to start pedaling, and stabilizes the left-right and front-to-back balance when riding and driving, allowing for safe and secure riding.

[0037] In this embodiment, the front frame 3 and the swing arm 41 are connected to the left and right of the swing arm 41 so that they can tilt left and right. This allows the entire vehicle body to remain neutral when stationary. This eliminates the need to hang the electrically assisted four-wheel bicycle 1 on a stand to secure the electrically assisted four-wheel bicycle 1. This allows elderly people to handle the electrically assisted four-wheel bicycle 1 comfortably.

[0038] In this embodiment, the position of the seat 71 can be adjusted in the front-rear direction, which allows the position of the seat 71 to be adjusted to suit the driver's body type.

[0039] In particular, in this embodiment, by arranging the battery 81 between the steering shaft 12 and the crankshaft 65, the center of gravity of the vehicle body is positioned forward, improving riding stability. This allows even elderly people to ride the electrically assisted four-wheel bicycle 1 safely and securely.

[0040] In addition, in this embodiment, in particular, the front basket 76 is located above the rotation center of the two front wheels 42, which further improves running stability when loaded. This allows even elderly people to drive safely and securely.

[0041] The present invention is not limited to the above-described embodiment, and various modifications are possible within the scope of the spirit and technical concept of the present invention.

[0042] Furthermore, in the above description, when the external dimensions or sizes are described as "same," "equal," or "different," these descriptions are not used in their strict sense. In other words, "same," "equal," and "different" mean "substantially the same," "substantially equal," or "substantially different," allowing for design and manufacturing tolerances and errors.

[0043] In addition to the above, the methods according to the above embodiments and modifications may be used in appropriate combination.

[0044] Although not specifically illustrated, the present invention can be implemented with various modifications within the scope of the invention. [Explanation of symbols]

[0045] 1 Electrically assisted four-wheel bicycle 2 Body frame 3 Previous Frame 4 Rear frame 12 Steering shaft 25a horizontal part 41 Swing arm 42 front wheel 52 rear wheel 64a, 64b crank 65 crankshaft 71 seats 72 Waist support member 76 Front basket 81 Battery H Vertical distance L Anteroposterior distance

Claims

1. A seat for a driver to sit on, a vehicle body frame that supports the seat; two front wheels disposed on the front side of the body frame; two rear wheels disposed on the rear side of the body frame; a crank that rotates around a crankshaft and transmits power to the rear wheel; a waist support member for supporting the waist of the driver seated in the seat, a distance L in the front-to-rear direction from the center of the crankshaft to the rearmost end of the seat is greater than a distance H in the up-down direction perpendicular to the front-to-rear direction from the center of the crankshaft to the uppermost end of the seat, The waist support member is The seat is supported by the vehicle body frame via a seat frame so that its lower end is spaced above the upper end of the seat and its left-right position is located between the left-right positions of one of the two rear wheels and the other rear wheel. A four-wheeled bicycle characterized by:

2. The four-wheel bicycle according to claim 1, a swing arm that rotatably supports the front wheel; a front frame that connects the swing arm to the center in a left-right direction perpendicular to the front-rear direction and the up-down direction of the four-wheeled bicycle so that the swing arm can tilt left and right. A four-wheeled bicycle characterized by:

3. The four-wheeled bicycle according to claim 1 or 2, The seat is adjustable in position in the front-rear direction. A four-wheeled bicycle characterized by:

4. The four-wheeled bicycle according to any one of claims 1 to 3, a steering shaft for steering the front wheels; a drive battery that is disposed between the steering shaft and the crankshaft and drives the rear wheels via the crank. A four-wheeled bicycle characterized by:

5. The four-wheeled bicycle according to any one of claims 1 to 4, The vehicle body frame is A horizontal portion extending parallel to the front-rear direction between the crankshaft and the seat is provided. A four-wheeled bicycle characterized by:

6. The four-wheeled bicycle according to any one of claims 1 to 5, Front basket and a front frame that supports the front basket above the rotation center of the front wheel. A four-wheeled bicycle characterized by:

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