JPH0722258Y2 - Electric wheelchair - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to an electric wheelchair, and more particularly to an electric wheelchair including a drive motor for independently driving and controlling each rear wheel.

[Prior Art] Generally, a suspension system for a vehicle is conceived to have a spring element between a rotating shaft of a tire and a vehicle body for the purpose of improving the riding comfort of the vehicle. Plays an important role.

． Even if the vehicle body moves up and down due to the unevenness of the road surface, the ground pressure of the tire does not change much because of the spring, and stable maneuverability is obtained.

． Since the impact input from the road surface is absorbed by the spring and the damping system, the force transmitted to the vehicle body is reduced, which not only improves the riding comfort but is also advantageous in strength.

Recently, suspension systems of left and right independent suspension systems have been widely used for the purpose of reducing the weight of the entire vehicle and improving the maneuverability even in an electric wheelchair or the like.

A conventional example is shown in FIGS.

In the conventional example shown in FIGS. 4 to 5, the vehicle body is composed of two parts, a seat portion 50 and a so-called underbody 60 supporting the seat portion.

The seat portion 50 is a seat frame that supports a seat for a chair.
51, an underseat cushion 52 attached to a lower portion of the seat frame 51, and a back cushion (see FIG. 3) attached to a rear surface (right side in FIG. 1) of the seat frame 51. There is.

Of these, the seat frame 51 is made of a tubular member, and includes a rectangular portion (not shown) in a horizontal plane for mounting the rectangular underseat cushion 52, and one short side (back side) of the rectangle. Standing part 51a for standing up at a predetermined angle and mounting the back seat cushion
And an elbow hook portion 51b (see FIG. 4) that rises substantially vertically from both left and right long side portions. Further, the four corners of the above-mentioned rectangular portion of the seat frame 51 are respectively provided with feet extending downward. An armrest cushion 53 is fixed to the upper surface of each elbow hook 51b.

The underbody 60 includes a main body frame 61, one left and right front wheel 62, 62 that supports the main body frame 61, and one left and right rear wheel 6 respectively.
It has 3,63 and.

Among them, the main body frame 61 is composed of a frame body in which a tubular member is formed in a rectangular shape. A joint portion 6 including seat frame support portions 64A for supporting the foot portions of the seat frame 51 described above is connected to both left and right front portions of the main body frame 61 while connecting the front and side tubular members to each other.
4 are provided respectively. A steering shaft of a front fork 65 that pivotally supports the front wheel 62 is rotatably mounted on each joint 64.

Seat frame support portions 64B that support the remaining foot portions of the seat frame 51 are provided at both ends of the rear portion of the body frame 61.

In addition, one end of a swing arm 66 serving as a suspension arm is mounted on each of the joint portions 64 described above so as to be rotatable about a fulcrum 66a in the directions of symbols B and B '(see FIG. 4). A shock absorber 67 is mounted between the portion near the other end of the swing arm 66 and the rear portion of the body frame as shown in FIG. The shock absorber 67 is a kind of vibration attenuator and has a function of absorbing vibration.

Further, at the other end of each swing arm 66, the rotary shaft of the rear wheel 63 is
It is equipped with a 63A, a gear box 68 and a drive motor M. A gear mechanism (not shown) for transmitting the rotational driving force of the drive motor M to the rotation shaft is incorporated inside the gear box 68.

With the above-described structure, the rear wheel moves up and down about the rotation fulcrum 66a during traveling, and the repeated vibration is absorbed by the shock absorber 67, so that the grounding property and the cushioning property are ensured. .

[Problems to be solved by the device]

However, the above conventional example, as shown in FIG. 5, the center line C ₂ of the center line C ₁ and the rear wheel 63 of the swing arm 66
Is displaced by a distance F, a "twist" is applied to the main body frame 61 via the swing arm 66 and the joint portion 64 due to the load in the vertical direction, and in the case where the vehicle leans, the rear wheel 63 A large "bending force" was applied to the swing arm 66 and the main body frame 61 due to the partial pressure load from the side surface. Therefore, a relatively thick member is used because it is necessary to have sufficient strength to withstand these twisting force and bending force, which inevitably results in a heavy weight and an expensive product.

[Purpose of device]

The present invention provides an electric wheelchair that improves the inconveniences of the conventional example and, in particular, suppresses the occurrence of twisting of the entire vehicle body, thereby reducing the weight of the entire vehicle body and reducing the cost. Is the purpose.

[Means for Solving the Problems]

According to the present invention, a main body frame that supports a seat for a chair and rotatably holds a steering shaft for a front wheel, one end of which is rotatably supported on the left and right front portions of the main body frame, and the other end of which is the main body frame. A pair of left and right swing arms disposed inside the left and right rear wheels, a drive motor mounted on the other end of each swing arm for individually driving each rear wheel via a gear box, A shock absorber is provided between the other end of the swing arm and the body frame.

The main body frame located between the rear wheels is fixedly equipped with a downward hanging plate, and each drive motor is arranged on the back side of the downward plate.

In addition, at least two connecting rods are arranged horizontally and in parallel with each other on the front side of the left and right ends of the above-mentioned hanging plate, separately with a predetermined interval vertically.

Then, the end portions of each of the two connecting rods arranged on the front surface side of the hanging plate on the rear wheel side are simultaneously lifted and lowered in a plane parallel to the surface of the hanging plate. Allowed and rotatably mounted on the front side of the gear box described above.

At the same time, the end portions of the two connecting rods on the side of the hanging plate described above are respectively rotatable to the hanging plate by allowing the connecting rods to simultaneously rise and fall along the surface of the hanging plate. It is installed on the. This aims to achieve the above-mentioned object.

[Action]

In the present invention, when a swinging moment is applied to the swing arm 2 and the main body frame 61 during traveling, the plate 6 welded to the frame 61 and the bracket 8 fixed to the gear box 68 can rotate two pieces. Since the parallel link mechanism 10 is formed by being connected by the connecting rods 5, 5, the connecting rods 5 rotate in the vertical direction to reduce the influence of the twisting moment. Further, when a bending moment due to a load from the side surface of the rear wheel 63 is received, its influence can be reduced by the tensile stress or compressive stress generated in each connecting rod 5.

[Example of device]

An embodiment of the present invention will be described below with reference to FIGS. Here, the same reference numerals are used for the same components as those of the conventional example described above.

The embodiment shown in FIGS. 1 to 3 is a seat for a chair.
Seat frame 51 that supports 52 and this seat frame
A main body frame 61 which supports 51 and also rotatably holds a steering shaft for a front wheel 62, and one end portion of which is rotatably supported at the left and right front portions of the main body frame 61 and the other end portion of which is behind the main body frame 61 , A pair of left and right swing arms 2, 2 disposed inside the left and right rear wheels 63, and each rear wheel 63 provided at the other end of each swing arm 2 individually through gear boxes 68, 68. Drive motors M, M for driving and a shock absorber 67 provided between the other end of each swing arm 2 and the body frame 61 are provided.

A downward hanging plate 6 is fixedly mounted on a main body ram 61 portion located between the rear wheels. Reference numeral 6A indicates a reinforcing plate for firmly mounting the hanging plate 6 on the main body frame 61. The drive motors M described above are arranged on the back side of the hanging plate 6.

In addition, at least two connecting rods 5, 5 are individually arranged horizontally and in parallel to each other on the front side of the left and right ends of the hanging plate 6 described above, with a predetermined interval therebetween.

The end portions of the two connecting rods 5 arranged on the front surface side of the hanging plate 6 on the rear wheel 63 side are simultaneously undulated in the plane parallel to the surface of the hanging plate 6. Allowing rotation, the gearboxes 68 are rotatably mounted on the front side of the gearboxes 68 via the brackets 8, respectively.

At the same time, the end portions of the two connecting rods 5 located on the above-mentioned hanging plate 6 side allow the connecting rods 5 to oscillate and rotate at the same time along the surface of the above-mentioned hanging plate 6. Each plate 6 is rotatably mounted.

This will be described in more detail. FIG. 1 shows an essential part of this embodiment, and FIG. 2 shows an underbody part of this embodiment.

In FIGS. 1 and 2, the gear box 68 is shown.
Is mounted on one end (right end in FIG. 2) of the swing arm 2. In the inside of the gear box 68, the rotational driving force of the motor M is supplied to the rotary shaft 63 of the rear wheel 63 as in the conventional example described above.
A gear mechanism (not shown) for transmitting to A is incorporated. A bracket 8 having an L-shaped cross section is fixed to the gear box 68 with screws 11A and 11B.

At the rear of the body frame 61, the tire rotation shaft shown in FIG.
The upper end of a flat plate-shaped hanging plate 6 arranged in parallel with 63A and in the vertical direction is welded. In this case, the surface of the hanging plate 6 and one surface of the bracket 8 (the surface not screwed to the gear box) are set to be substantially on the same surface.

In this state, in the present embodiment, the hanging plate 6 and the bracket 8 are connected by two parallel connecting rods 5 and 5 having the same shape and equipped with elbows 4 at both ends as shown in FIG. There is. The connecting rods 5 and 5 are pivotal fulcrums 4A and
It can rotate around 4A. Also, connecting rod
5, 5 and the bracket 8 form a fixed link (a portion between the pivoting fulcrums 4A, 4A of the connecting rod 5 on the hanging plate 6 side) in the vertical plane, whereby the rear wheel 63 as a tire rotating shaft. A parallel link mechanism 10 that moves in a plane parallel to the rotation axis 63A is formed.

The other end (the left end in FIG. 2) of the swing arm 2 is connected to the main body frame via a joint portion 64 so as to be rotatable about the fulcrum 2a in the directions A and A ′ in FIG. Equipped to 61. Further, a shock absorber 67 is provided between the other end of the swing arm 2 and the rear part of the frame 61. Other configurations are the same as those of the conventional example described above.

As described above, in this embodiment, the plate 6 welded to the frame 61 and the bracket 8 fixed to the gear box 68 are connected by the two rotatable connecting rods 5 and 5, and the parallel link mechanism 10 is formed. Since it is formed, even if the vertical load acts and the rear wheel 63 moves up and down, and the twisting moment acts on the swing arm 2 and the main body frame 61, the connecting rods 5 are shown in FIG. The effect of the torsion moment can be mitigated by rotating in the up-down direction around the rotation fulcrum 4A shown. Further, when a bending moment due to a load from the side surface of the rear wheel 63 is received, the influence can be reduced by the tensile stress or the compressive stress generated in each connecting rod 5.

For this reason, it is possible to set the required strength of the members forming the swing arm 2 and the main body frame 61 to a low level, and there is an advantage that the weight and cost can be reduced.

Further, due to the action of the hanging plate 6, the pair of connecting rods 5 can be easily equipped, and the workability therefor is remarkably improved. At the same time, the hanging plate 6 is
The main body frame 61 is also reinforced, and in this respect also, the main body frame 61 portion can be reduced in weight while maintaining its strength.

Further, in the above embodiment, the drive motors for the rear wheels 63, 63 are arranged on the back side of the hanging plate 6 as shown in FIG. Damage can be effectively eliminated, and in this respect, the failure rate of the entire device can be reduced and the durability of the entire device can be increased.

[Effect of device]

Since the present invention is constructed and functions as described above, according to this, even when the swing arm and the body frame are twisted together with the vertical load acting on the tire portion, the hanging plate and the gearbox side are Due to the linking action of the pair of connecting rods installed between them, it is possible to constantly move the tire rotating shaft up and down in the same plane without tilting it with respect to the main body frame, and thus the torsional force acts on the main body frame. It is possible to surely relax, and it is possible to reduce the influence of the stress generated in the connecting rod against the bending moment due to the load from the side surface of the tire. It is possible to reduce the weight and cost of its components while maintaining the required strength, and the function of the hanging plate. This makes it easier to equip a pair of connecting rods, and the workability for that is significantly improved.At the same time, this hanging plate also serves as a reinforcement for the main body frame, and in this respect also the main body frame part It is possible to reduce the weight while maintaining its strength. At the same time, because the drive motor for the rear wheels is placed on the back side of the hanging plate, the drive motor will be damaged by water splashes and flying stones generated during running. Thus, it is possible to provide a practical electric wheelchair that has never been used, in which the failure rate of the entire device can be reduced and the durability of the entire device can be increased.

[Brief description of drawings]

FIG. 1 is a partially omitted front view showing a main part of an embodiment of the present invention, FIG. 2 is an overall configuration diagram including a main body frame seen from the right side of FIG. 1, and FIG. 3 is FIG. 4 is an overall perspective view showing a conventional example, and FIG. 5 is an explanatory view showing a positional relationship between the main body frame and the rear wheels of FIG. . 2 ... Swing arm (suspension arm), 5 ...
… Connecting rod, 6… Hanging plate, 61… Body frame,
63 …… rear wheel, 67 …… shock absorber, 68 …… gearbox, M …… drive motor.

Claims (1)

[Scope of utility model registration request] 1. A body frame for supporting a seat for a chair and rotatably holding a steering shaft for front wheels, and one end portion rotatably supported on the left and right front portions of the body frame, and the other end portion is aforesaid. A pair of left and right swing arms arranged behind the body frame inside the left and right rear wheels, and a drive motor mounted on the other end of each swing arm to individually drive the respective rear wheels via a gear box. And a shock absorber mounted between the other end of each of the swing arms and the main body frame, wherein a downward hanging plate is fixed to a main body ram located between the rear wheels. The drive motors are mounted on the back side of the hanging plate, and the two driving motors are individually connected to the front side of the left and right end portions of the hanging plate and vertically separated by a predetermined distance. Are arranged horizontally and in parallel with each other, and the end portions on the rear wheel side of each of the two connecting rods arranged on the front surface side of the hanging plate are connected to each other in the plane parallel to the surface of the hanging plate. The connecting rods are allowed to rotate up and down at the same time and are rotatably mounted on the gear box side, respectively, and the end portions of the two connecting rods on the hanging plate side are arranged along the surface of the hanging plate. An electric wheelchair, wherein each of the connecting rods is rotatably attached to the hanging plate while allowing the connecting rods to rotate up and down at the same time.