JP2022022574A - Hub unit and wheelchair having the same - Google Patents

Abstract

To provide a hub unit in which a delay in initial motion until locking is reduced to the minimum so as to prevent a shock and the like at the time of stop.SOLUTION: A backing prevention unit 100 which is a hub unit provided to a vehicle shaft of a wheelchair, includes: a hub plate 110 to which a spoke of a driving wheel is connected; and an operation plate 130 to which a hand rim is connected. When a reverse rotation torque from the driving wheel acts on the hub plate 110, the operation plate 130 relatively moves in a rotation direction, and first and second planetary gears inside come into an engagement state for locking. On the other hand, when an operation force is applied to the hand rim, the engagement state of the gears is released and the operation force is transmitted to the driving wheel. By providing return means 137 for urging the operation plate 130 at all times toward an initial position in the rotation direction, a delay in initial motion until locking operation can be made small and stable.SELECTED DRAWING: Figure 4

Description

The present invention relates to a hub unit having a reverse rotation prevention function for drive wheels and a wheelchair provided with the hub unit.

The manual wheelchair is configured so that the user can perform driving operations such as forward, reverse, left turn, and right turn by operating the left and right drive wheels (main wheels) with his / her own hands. In such a wheelchair, a taggle brake is provided, for example, in order to prevent a fall accident when a user transfers. Further, a wheelchair for the purpose of more stable parking lock has also been proposed (see, for example, Patent Document 1).

However, with conventional wheelchairs, for example, it is not possible to ensure sufficient safety when climbing up and down the slope on its own, and especially for elderly people with weakened strength, the help of a caregiver is required so that the vehicle body does not move backward in the middle. Is. In relation to this problem, in recent years, a special power transmission mechanism (hub unit) that mechanically locks the drive wheels when a reverse rotation torque acts on the drive wheels of a wheelchair has been proposed (see, for example, Patent Document 2). ).

Japanese Unexamined Patent Publication No. 2019-17659 Japanese Patent No. 5105256

The power transmission mechanism provided with the reverse rotation prevention function according to the above patent is provided with rotation restricting means for allowing the axes of the first planetary gear member and the second planetary gear member to rotate relatively in close directions. ing. Specifically, the rotation regulating means is provided in the notch provided in the first carrier member in which the first planetary gear member is arranged and in the second carrier member in which the second planetary gear member is arranged, and the inside of the notch is provided. It consists of freely moving regulatory pins. When the drive wheel of the wheelchair starts to rotate backward, the regulation pin moves in the notch and the axes of the first planetary gear member and the second planetary gear member come close to each other. At this time, the first planetary gear member and the second planetary gear member are engaged with each other, and the rotation is locked.

Due to the structure of the power transmission mechanism having such a mechanism, there is a difference until the drive wheels lock (initial movement delay) depending on the position where the regulation pin of the rotation regulating means is in the notch. In the case of a wheelchair, if the lock timing differs between the left and right drive wheels, the vehicle body may make a sharp turn with the drive wheel on the side that stopped first as the fulcrum. Further, if the initial movement delay of the lock is large, shock or knocking may occur when the drive wheels are stopped, which is not preferable.

The present invention has been made to solve such a problem that has become apparent in the process of developing a wheelchair, and by taking improvement measures such as making the initial movement delay of the lock as small as possible or making the delay constant. It is an object of the present invention to provide a hub unit and a wheelchair equipped with the hub unit so as to eliminate problems such as unintentional turning and shock of the vehicle body at the time of locking.

In order to solve the above-mentioned problems, the present invention comprises an axle member whose reference axis is its own axis, and a sun gear fixed to the axle member so that the reference axis and the axis of the axle member are aligned with each other. A hub plate pivotally supported by the axle member in a manner rotatable about the reference axis, and a hub pivotally supported by the axle member in a manner rotatable about the reference shaft center. An operation plate arranged parallel to and facing the plate and pivotally supported by the hub plate in a manner rotatable around a first axis parallel to the reference axis, with the reference axis as the center. The first planetary gear arranged on the circumference of the first revolution radius and the reference axis are pivotally supported by the operation plate so as to be rotatable around the second axis parallel to the reference axis. The reference axis is provided with a second planetary gear that is arranged on the circumference of a second revolution radius smaller than the first revolution radius centered on the center and meshes with the sun gear and the first planetary gear, respectively. The line connecting the reference axis and the axis of the second planetary gear is tilted at a predetermined angle in the reverse rotation direction of the hub plate and the operation plate with respect to the line connecting the axis of the first planetary gear and the axis of the first planetary gear. The shaft member of the second planetary gear is formed in the hub plate and is penetrated through a shaft relief hole having an inner diameter larger than the outer diameter of the shaft member, so that the operation plate is formed with respect to the hub plate. The allowable angle range in which the wheel can rotate relative to each other is defined, and the meshing state between the first planetary gear and the second planetary gear changes according to the relative rotation position of the operation plate with respect to the hub plate. Further, the operation plate is constantly urged to rotate relative to the hub plate toward the initial position in the forward rotation direction in which the distance between the axes of the first planetary gear and the second planetary gear becomes smaller. It is a hub unit equipped with an initial position return means.

Further, in the present invention, a chair-type vehicle body frame, a drive wheel rotatably provided on the vehicle body frame via the hub unit according to claim 1, and a hand rim for operating the drive wheel are provided. The wheelchair is a wheelchair in which the axle member is supported and fixed to the axle mounting portion of the vehicle body frame, the spokes of the drive wheels are connected to the hub plate, and the hand rim is connected to the operation plate.

According to the present invention, it is possible to reduce the initial movement delay of the lock when a reverse rotation torque is applied to the hub unit, so that it is possible to prevent shock and knocking when the lock is stopped. In addition, the initial movement delay of the lock can be made constant by the left and right drive wheels, and it is possible to avoid a situation in which the vehicle body turns unintentionally when stopped.

It is a side view of the wheelchair by one Embodiment of this invention. It is a front view of the wheelchair of FIG. It is a top view which shows the mounting structure of the reverse movement prevention unit which is one Embodiment of the hub unit of this invention. It is an external perspective view of the reverse movement prevention unit seen from the front outside. It is the external perspective view which looked at the reverse movement prevention unit from the front inside. It is an external perspective view of the reverse movement prevention unit seen from the outside substantially front. It is a side view which shows by disassembling the reverse movement prevention unit. It is a side view which shows the internal structure of the reverse movement prevention unit. It is a figure for demonstrating the gear arrangement structure of the reverse movement prevention unit. (A) is a side view of the outer hub plate, and (b) is a gear mounting surface view of the outer hub plate. (A) is a gear mounting top view of the inner hub plate, and (b) is a side view of the inner hub plate. It is sectional drawing of the spacer part which joins the outer hub plate and the inner hub plate. (A) is a diagram for explaining the operation of the reverse movement prevention unit when a forward operation force is applied, and (b) is a diagram for explaining the operation of the wheelchair corresponding to the operation. (A) is a diagram for explaining the operation of the reverse movement prevention unit when a reverse movement operation force is applied, and (b) is a diagram for explaining the operation of the wheelchair corresponding to the operation. (A) is a diagram for explaining the operation of the reverse rotation prevention unit when the reverse rotation torque is applied, and (b) is a diagram for explaining the operation of the wheelchair corresponding to the operation.

Hereinafter, preferred embodiments of the wheelchair according to the present invention and the hub unit attached to the main wheel of the wheelchair will be described in detail. First, the configuration of a wheelchair according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2. The wheelchair described below is a general one, and the implementation of the present invention is not limited to the wheelchair having this configuration. Further, in the present specification, the "user" means a person who gets on a wheelchair unless otherwise specified.

(Explanation of wheelchair)
FIG. 1 is a side view of a wheelchair 1 according to an embodiment of the present invention, and FIG. 2 is a front view thereof. The wheelchair 1 includes a body frame 10 assembled in a chair shape and a main wheel 20 which is a pair of left and right driving wheels.

The vehicle body frame 10 includes left and right side frames 11 and 11 and an X-shaped crossbar member 19 that connects the side frames 11 and 11. The crossbar member 19 has a folding mechanism that allows the left and right side frames 11 and 11 to approach and separate from each other in order to allow the wheelchair 1 to be compactly folded and stored. A seating seat 41 is provided between the left and right side frames 11 and 11.

The side frame 11 basically has a rigid frame structure in which the front vertical frame 12, the back frame 13, the upper horizontal frame 14, and the lower horizontal frame 15 are rigidly joined. A caster wheel 30 is provided at the lower end of the front vertical frame 12. The caster wheel 30 prevents the wheelchair 1 from tipping over, and is steered so that the wheelchair 1 faces the traveling direction by turning around the vertical axis of the front vertical frame 12.

A back support (backrest portion) 42 is stretched between the left and right back frames 13 and 13. Further, the upper portion of the front vertical frame 12 is a bent portion that bends horizontally toward the rear, and the arm support frame 16 is joined so as to pass between the bent portion and the back frame 13. An arm support (accoudoir portion) 18 is provided on the horizontal portion of the arm support frame 16. The reinforcing frame 17 may be joined between the lower portion of the upper horizontal frame 14 and the front vertical frame 12.

Further, the rear end portion of the lower horizontal frame 15 extending rearward from the back frame 13 is a tipping lever 45. The tipping lever 45 is a lever for the caregiver to step on when riding on the caster 30 on a step or the like. A flip-up type foot support (footrest portion) 43 is provided in front of the lower part of the front vertical frame 12.

A grip portion 44 held by a caregiver for operating the wheelchair 1 from the rear is formed in a portion of the upper part of the back frame 13 that bends backward. The grip portion 44 includes a brake operation lever 45A for performing an operation for restricting the rotation of the main wheel 20, and a reverse lock release operation lever 45B for performing an operation for releasing the reverse lock of the reverse movement prevention unit 100 described later. Is provided.

The main wheel 20, which is the drive wheel of the wheelchair 1, rotates to the axle mounting portion at the lower part of the back frame 13 via the reverse rotation prevention unit (also referred to as “reverse rotation prevention unit”) 100, which is a hub unit. It is provided as possible. The spokes 21, 21, ... Of the main wheel 20 are connected to the outer hub plate 110 and the inner hub plate 120 of the reverse movement prevention unit 100, which will be described later. On the outside of the main wheel 20, a hand rim 22 is provided for the passenger of the wheelchair 1 to apply an operating force to the main wheel 20 to perform a traveling operation. In a general wheelchair, the hand rim is directly connected to the rim of the main wheel, but in the wheelchair 1 according to the present embodiment, the hand rim 22 is attached to the outer operation plate 130 of the reverse movement prevention unit 100 via three rigid spokes 23. The connection is fixed.

(Explanation of reverse movement prevention unit)
Next, the configuration of the reverse rotation prevention unit 100, which is the hub unit according to the present invention and has a function of automatically locking the reverse rotation of the main wheel 20, will be described in detail. The reverse movement prevention unit 100 attached to the axle of the wheelchair 1 has a symmetrical structure, but in this specification, the reverse movement prevention unit 100 provided on the right side of the vehicle body will be described as an example of the structure.
Further, in the following description, "forward rotation" means rotation or rotation of the wheel 20, hub plates 110, 120, etc. in the direction corresponding to the forward movement of the wheelchair, and "reverse rotation" means reverse rotation of the wheelchair. They shall refer to their rotation or rotation in a direction.

Here, FIG. 4 is an external perspective view of the reverse movement prevention unit 100 as viewed from the front outside, FIG. 5 is an external perspective view of the reverse movement prevention unit 100 as viewed from the front inside, and FIG. 6 is an abbreviation for the reverse movement prevention unit 100. It is an external perspective view seen from the front. Note that FIG. 6 shows a part of the internal gear structure with the cover 160 removed.

The reverse movement prevention unit 100 includes an axle member 150 that is supported and fixed to the axle mounting portion of the wheelchair 1, and an outer hub plate 110 that penetrates the axle member 150 and is rotatably supported around the axis of the axle member 150. The inner hub plate 120, which also penetrates the axle member 150 and is rotatably supported around the axis of the axle member 150 and is arranged parallel to and facing the outer hub plate 110, and the outer hub plate. The sun gear 161, the first planetary gear 162, 162, 162 and the second planetary gear 163, 163, 163 arranged between the 110 and the inner hub plate 120 are penetrated through the axle member 150, and the axis of the axle member 150 is passed through. The outer operation plate 130, which is rotatably supported in the center and is arranged further outside the outer hub plate 110 in parallel and facing the outer hub plate 110, and the axle member 150 are also penetrated through the axle member. The basic configuration is an inner operation plate 140 that is rotatably supported around the axis of the 150 and is arranged inside the inner hub plate 120 in parallel and facing the inner hub plate 120. It is an element.

(Gear arrangement structure)
First, referring to FIGS. 7 to 9, the sun gear 161 and the first planetary gear 162, 162, 162 and the spur gears of the same module, which are arranged between the outer hub plate 110 and the inner hub plate 120, are the first. 2 The gear arrangement structure of the planetary gears 163, 163, 163 will be described. The sun gear 161 is fixed to the axle member 150 with its axis aligned with the axle member 150. Here, the axis of the axle member 150 and the axis of the sun gear 161 corresponding thereto are defined as the "reference axis".

The three first planetary gears 162, 162, 162 are outer hubs in such a manner that they can rotate around the axes of the respective shaft members 162a, 162a, 162a (these are referred to as "first revolution axes"). It is pivotally supported by a bearing portion 1102 formed on the gear mounting surface 110A of the plate 110 and a bearing portion 1202 formed on the gear mounting surface 120A of the inner hub plate 120. Each of the first revolution axes of the first planetary gears 162, 162, 162 is parallel to the reference axis of the axle member 150 and is on the circumference of the first revolution radius centered on the reference axis. They are arranged at equal intervals of 120 ° from each other (see FIG. 9).

Further, the three second planetary gears 163,163,163 are the axes of the shaft core members 164, 164, 164 penetrating the centers of the shaft members 163a, 163a, 163a, respectively (these are referred to as "second revolution shaft centers"). ) Is rotatable around the bearing portion 1302 formed on the outer operation plate 130 and the bearing portion 1402 formed on the inner operation plate 140. The second revolution axis of each of the second planetary gears 163, 163, 163 is parallel to the reference axis of the axle member 150 and is on the circumference of the second revolution radius centered on the reference axis. They are arranged at equal intervals of 120 ° from each other.

Further, the shaft members 163a, 163a, 163a (including the shaft core members 164, 164, 164) of the second planetary gears 163, 163, 163 include the shaft relief holes 1103, 1103, 1103 and the inner hub plate of the outer hub plate 110. It is pivotally supported by the outer operation plate 130 and the inner operation plate 140 via the shaft escape holes 1203, 1203, 1203 of the 120. Here, the inner diameters of the shaft relief holes 1103 and 1203 have a clearance slightly larger than the outer diameter of the shaft member 163a of the second planetary gear 163. Within the slight permissible angle range defined by the clearance, the outer operating plate 130 and the inner operating plate 140 are made rotatable relative to the outer hub plate 110 and the inner hub plate 120 about the reference axis. ing.

Further, as shown in FIG. 9, the second revolution radius of the second planetary gear 163 is smaller than the first revolution radius of the first planetary gear 162. That is, the first planetary gear 162 meshes with the second planetary gear 163, and the second planetary gear 163 meshes with the sun gear 161 and the first planetary gear 162. Further, the reference axis and the second revolution axis of the second planetary gear 163 are connected to the first revolution radius line connecting the reference axis of the sun gear 161 and the first revolution axis of the first planetary gear 162. The second revolution radius line is tilted by a slight predetermined angle in the reverse rotation direction (counterclockwise direction in FIG. 9).

(Outer hub plate)
Next, the configuration of the outer hub plate 110 will be described. 10 (a) is a side view of the outer hub plate 110, and FIG. 10 (b) is a view showing a gear mounting surface 110A (a surface on the side facing the inner hub plate 120) of the outer hub plate 110. The outer hub plate 110 is a die-cast member obtained by press-fitting an aluminum alloy such as ADC 12 into a substantially disk shape. An axle hole 1101 for fitting a bearing 111 that pivotally supports the axle member 150 is formed in the central portion of the outer hub plate 110. Further, the bearing portions 1102, 1102, 1102 for rotatably receiving the shaft member 162a of the first planetary gear 162 are 120 each other on the circumference of the first revolution radius centered on the reference axis of the axle hole 1101. It is formed at three predetermined locations with an interval of °. Further, on the gear mounting surface 110A, shaft escape holes 1103, 1103, 1103 through which the shaft member 163a of the second planetary gear 163 penetrates are on the circumference of the second revolution radius centered on the reference axis of the axle hole 1101. They are formed at equal intervals of 120 ° from each other at predetermined positions.

Further, on the gear mounting surface 110A of the outer hub plate 110, columnar large-diameter spacer portions 1104, 1104, ... Are formed at a plurality of locations (six locations in the present embodiment). A concave fitting portion 1104a is formed at the tip portion of the large diameter spacer portion 1104. The concave fitting portion 1104a is formed in a dimensional shape that can be fitted in a state of being abutted against the tip portion (convex fitting portion 1204a) of the corresponding small diameter spacer portion 1204 of the inner hub plate 120.

Further, the outer hub plate 110 is provided with a key escape hole 1105 for inserting and removing the unlock key member 211 of the unlocking mechanism portion 200, which will be described later, and a leg portion of the unlocking key plate 210 of the unlocking mechanism portion 200. Key plate support holes 1106 and 1106 for supporting are formed. Further, a plurality of screw holes 1107 for fixing the spoke support plate 112 with bolts 136 are formed on the peripheral portion of the outer hub plate 110.

For example, the spoke support plate 112 shown in FIG. 4 is an annular metal plate member, and the spoke connection holes 112a for connecting the ends of the spokes 21, 21, ... Of the main wheel 20 are provided on the peripheral portion thereof. Multiple are formed. The spoke support plate 112 is detachably fixed by bolts 136 so as to overlap the outer peripheral edge of the outer hub plate 110.

(Inner hub plate)
Next, the configuration of the inner hub plate 120 will be described. 11 (a) is a view showing the gear mounting surface 120A (the surface on the side facing the outer hub plate 110) of the inner hub plate 120, and FIG. 11 (b) is a side view of the inner hub plate 120. Like the outer hub plate 110, the inner hub plate 120 is a die-cast member obtained by press-fitting an aluminum alloy such as ADC 12 into a substantially disk shape.

An axle hole 1201 for fitting a bearing 121 that pivotally supports the axle member 150 is formed in the central portion of the inner hub plate 120. Further, the bearing portions 1202, 1202, 1202 that rotatably receive the shaft member 162a of the first planetary gear 162 are 120 ° to each other on the circumference of the first revolution radius centered on the reference axis of the axle hole 1201. It is formed at predetermined three locations with an interval. Further, on the gear mounting surface 120A, shaft relief holes 1203, 1203, 1203 for passing through the shaft member 163a of the second planetary gear 163 are provided at predetermined positions on the circumference of the second revolution radius centered on the reference axis. They are formed at equal intervals of 120 ° from each other.

Further, on the gear mounting surface 120A, columnar small-diameter spacer portions 1204, 1204, ... Are formed at a plurality of locations (six locations in the present embodiment). A convex fitting portion 1204a is formed at the tip portion of the small diameter spacer portion 1204. The tip portion (convex fitting portion 1204a) of these small diameter spacer portions 1204 is fitted in a state of being abutted against the tip portion (concave fitting portion 1104a) of the corresponding large diameter spacer portion 1104 of the outer hub plate 110. It is formed in a possible size and shape. Further, the tip portion of the small diameter spacer portion 1204 can be appropriately shaped so as to have, for example, a stepped portion or a tapered portion, as long as it can be fitted in close contact with the tip portion of the large diameter spacer portion 1104.

As shown in FIG. 12, a screw hole 1204b is screwed into the convex fitting portion 1204a which is the tip portion of the small diameter spacer portion 1204. The concave fitting portion 1104a of the large diameter spacer portion 1104 and the convex fitting portion 1204a of the small diameter spacer portion 1204 are fitted, and the bolt 113 is inserted into the bolt hole 1104b of the large diameter spacer portion 1104 and screwed into the screw hole 1204b. By matching them, the large-diameter spacer portion 1104 and the small-diameter spacer portion 1204 can be joined in a butted state.

The bolt 113, the bolt hole 1104b, and the screw hole 1204b are joining means for joining the outer hub plate 110 and the inner hub plate 120 at regular intervals via the large diameter spacer portion 1104 and the small diameter spacer portion 1204. It is an element that constitutes.

Work to incorporate a hub unit with a complicated gear structure in which a sun gear and multiple planetary gears are incorporated between two hub plates into the hub of the main wheel while simultaneously performing axis alignment (shaft alignment) of all gears. Is not easy. However, according to the reverse movement prevention unit 100 of the present embodiment, only the tip portions of the large-diameter spacer portion 1104 on the outer hub plate 110 side and the small-diameter spacer portion 1204 on the inner hub plate 120 side are butted against each other and fitted to each other. The shaft centering of at least three planetary gears 162, 162, 162 can be performed simultaneously and easily, and the relative alignment of the outer hub plate 110 and the inner hub plate 120 can be easily performed.

Further, as shown in FIGS. 10 and 11, the large-diameter spacer portions 1104, 1104, ... And the small-diameter spacer portions 1204, 1204, ... Have predetermined radii centered on the reference axis of the axle hole 1101. It is preferable that they are arranged and formed on the circumference of the. As a result, after aligning the outer hub plate 110 and the inner hub plate 120 with the reference axis at the center of the axle member 150 (sun gear 161), the relative rotation positions of the large diameter spacer portion 1104 and the small diameter spacer portion 1204 are aligned. At least three planetary gears 162, 162, 162 can be centered at the same time. Furthermore, it is preferable that the intervals on the circumferences of the large-diameter spacer portions 1104, 1104, ... And the small-diameter spacer portions 1204, 1204, ... Are uneven. By doing so, it is possible to prevent an assembly error such that the relative rotational positional relationship between the outer hub plate 110 and the inner hub plate 120 is mistaken.

The inner hub plate 120 also has a key escape hole 1205 for inserting and removing the unlock key member 211 of the unlock mechanism unit 200, which will be described later, and a leg of the unlock key plate 210 of the unlock mechanism unit 200. Key plate support holes 1206, 1206 for supporting are formed. Further, a plurality of screw holes 1207 for fixing the spoke support plate 122 with bolts 126 are formed in the peripheral portion of the inner hub plate 120.

For example, the spoke support plate 122 shown in FIG. 5 is an annular metal plate member, and the spoke connection holes 122a for connecting the ends of the spokes 21, 21, ... Of the main wheel 20 are provided on the peripheral portion thereof. Multiple are formed. The spoke support plate 122 is detachably fixed by bolts 126 in such a manner that it overlaps the outer peripheral edge of the inner hub plate 120.

(Outer operation plate)
Next, the configuration of the outer operation plate 130 will be described. The outer operation plate 130 is a die-cast member obtained by press-fitting an aluminum alloy such as ADC12 into a star-shaped substantially disk shape. As shown in FIG. 7, for example, an axle hole 1301 for fitting a bearing 131 that pivotally supports the axle member 150 is formed in the central portion of the outer operation plate 130. Further, on the gear mounting surface (the surface facing the outer hub plate 110) of the outer operation plate 130, a bearing portion 1302 that rotatably receives the shaft member 162a of the second planetary gear 163 is provided on the outer hub plate 110. It is formed at three locations corresponding to the shaft escape holes 1103. A shaft core member 164 is slidably and rotatably penetrated inside the shaft member 162a of the second planetary gear 163, and the end portion of the shaft core member 164 is fixed by a bolt 132 inside the bearing portion 1302. ing.

On the outer surface of the outer operation plate 130 (the surface opposite to the gear mounting surface), for example, as shown in FIGS. 3 and 4, three rigid spokes 23, 23, 23 of the hand rim 22 are bolted 133, 133. The bases 130a, 130a, 130a for fixing with the bases 130a, 130a, 130a are integrally formed radially.

(Inner operation plate)
Next, the configuration of the inner operation plate 140 will be described. The inner operation plate 140 is a die-cast member obtained by press-fitting an aluminum alloy such as ADC12 into a substantially disk shape. As shown in FIG. 7, an axle hole 1401 for fitting a bearing 141 that pivotally supports the axle member 150 is formed in the central portion of the inner operation plate 140. Further, on the gear mounting surface (the surface facing the inner hub plate 120) of the inner operation plate 140, a bearing portion 1402 that rotatably receives the shaft member 162a of the second planetary gear 163 is provided on the inner hub plate 120. It is formed at three locations corresponding to the shaft escape hole 1203. The end portion of the shaft core member 164 that slidably and rotatably penetrates the shaft member 162a of the second planetary gear 163 is fixed to the inside of the bearing portion 1402 by a bolt 142.

The inner operation plate 140 has a cam hole (not shown) that engages with the unlock key member 211 of the unlock mechanism portion 200 described below, and a leg portion of the unlock key plate 210 of the unlock mechanism portion 200. A through hole (not shown) is formed to allow the through hole (not shown).

(Explanation of unlocking mechanism)
As shown in FIG. 3, for example, the unlock mechanism unit 200 has an unlock key plate 210, an unlock key member 211 fixed to the unlock key plate 210, and an unlock lever for moving the unlock key plate 210. It is configured to have 202. The unlock key plate 210 has a through hole 210a formed in the center thereof so as to slidably penetrate the axle member 150 (see FIG. 5), and approaches and separates the inner operation plate 140 along the axle member 150. It is provided so that it can be moved in the direction of movement.

A wire 201 is connected to the base end of the lock release lever 202, and the wire 201 is connected to the reverse lock release operation lever 45B (see FIG. 1). That is, when the caregiver of the wheelchair 1 grips the reverse lock release operation lever 45B, the wire 201 is pulled and the lock release lever 202 rotates, and the lock release key plate 210 is attached to the tip of the lock release lever 202. It is pushed and moves toward the inner operation plate 140. As the unlock key plate 210 moves, the wedge-shaped unlock key member 211 enters the cam hole (not shown) of the inner operation plate 140 described above, and rotates the inner operation plate 140 to the unlock position. ..

The "unlocked position" here means the counterclockwise rotation direction of the second revolution radius line of the second planetary gear 163 centered on the reference axis within the range allowed by the shaft relief hole 1203 (counterclockwise in FIG. 9). It means the relative rotation position of the outer operation plate 130 and the inner operation plate 140 with respect to the outer hub plate 110 and the inner hub plate 120, which are slightly moved in the clockwise direction). At this unlocked position, backlash between the first planetary gear 162 and the second planetary gear 163 is ensured, so that the first planetary gear 162 and the second planetary gear 163 centering on the sun gear 161 revolve and rotate. You will be free to move. As a result, the reverse lock of the main wheel 20 can be released.

(Explanation of initial position return means)
The reverse movement prevention unit 100 of the present embodiment sets the relative rotation position of the outer operation plate 130 and the inner operation plate 140 with respect to the outer hub plate 110 and the inner hub plate 120 to the initial position (also referred to as “neutral position”). It is equipped with an initial position return means for returning. The "initial position" or "neutral position" here means that the outer operation plate 130 and the inner operation plate 140 rotate relative to the outer hub plate 110 and the inner hub plate 120 in the forward rotation direction, and the second position is used. 1 means a relative rotation position where the axes of the planetary gears 162 and the second planetary gears 163 are close to each other and the backlash between these gears becomes zero or substantially zero. That is, the initial position returning means is an allowable angle range defined by the clearance between the inner diameters of the shaft relief holes 1103 and 1203 of the outer hub plate 110 and the inner hub plate 120 and the outer diameter of the shaft member 163a of the second planetary gear 163. Within, the outer operating plate 130 and the inner operating plate 140 are configured to be constantly urged to rotate relative to the outer hub plate 110 and the inner hub plate 120 toward the above-mentioned initial position.

For example, FIG. 4 illustrates three coil springs 137, 137, 137 as initial position return means. The coil spring 137 is provided so as to be stretched elastically and spanned between the bracket 115 planted in the outer hub plate 110 and the bracket 135 planted in the outer operation plate 130. In this case, the tensile elastic force of the coil spring 137 acts on the outer hub plate 110 so as to constantly rotate the outer operation plate 130 toward the forward rotation direction (clockwise in FIG. 4).

Further, as another aspect of the initial position return means, the shaft member 163a of the second planetary gear 163 is penetrated by interposing an elastic cushion material in the shaft relief holes 1103 and 1203 of the outer hub plate 110 and the inner hub plate 120. You may let me. Even with such a cushion material, the shaft member 163a can be held in the neutral position.

By providing such an initial position return means in the reverse movement prevention unit 100, the time and quantitative delay (lag) until the lock is activated when the wheelchair 1 is in reverse rotation (when the main wheel 20 is rotating in the reverse direction) is reduced. Moreover, such an initial movement delay can be made constant by the left and right main wheels 20. As a result, it is possible to prevent problems such as turning and shock of the vehicle body, which are likely to occur at the time of locking, and the vehicle body can be stopped smoothly.

(Operation explanation of the reverse movement prevention unit and the wheelchair equipped with it)
The operation of the wheelchair 1 provided with the reverse movement prevention unit 100 and the reverse movement prevention unit 100 on the hub of the main wheel 20, which is an embodiment of the hub unit according to the present invention, will be described below.

As described above, the reverse movement prevention unit 100 according to the present embodiment has the first planetary gear 162 according to the relative rotation positions of the outer operation plate 130 and the inner operation plate 140 with respect to the outer hub plate 110 and the inner hub plate 120. It is configured to change the meshing state between the second planetary gear 163 and the second planetary gear 163. The angle range that allows these relative rotations is the clearance between the inner diameters of the shaft relief holes 1103 and 1203 of the outer hub plate 110 and the inner hub plate 120 and the outer diameter of the shaft member 163a of the second planetary gear 163. Limited by.

In the reverse movement prevention unit 100 having such a configuration, first, a case where the forward operation force Ff is applied to the outer operation plate 130 will be described with reference to FIG. The forward operating force Ff applied to the outer operating plate 130 moves the axis of the second planetary gear 163 (shaft member 163a) in a direction that brings it closer to the axis of the first planetary gear 162 (shaft member 162a). At that time, each of the first planetary gear 162 and the second planetary gear 163 rotates around their own axis so that their pitch points are separated from each other. At the same time, each of the first planetary gear 162 and the second planetary gear 163 revolves around the sun gear 161. As a result, the forward operating force Ff is the outer hub plate 110 and the inner hub plate that pivotally support the first planetary gear 162. It is transmitted to 120 and converted into a forward driving force Tf that causes the hub plates 110 and 120 to rotate in the forward direction (see FIG. 13A).

In the wheelchair 1 of the present embodiment, the forward operating force Ff given via the hand rim 22 is converted into the forward driving force Tf by the reverse movement prevention unit 100 to rotate the main wheel 20 in the forward direction. Therefore, the hand rim 22 can be operated in the same manner as a general wheelchair to move the vehicle body forward (see FIG. 13 (b)).

Next, a case where the reverse operation force Fr is applied to the outer operation plate 130 of the reverse movement prevention unit 100 will be described with reference to FIG. The reverse operation force Fr applied to the outer operation plate 130 moves the axis of the second planetary gear 163 (shaft member 163a) in a direction away from the axis of the first planetary gear 162 (shaft member 162a). As a result, the backlash between the first planetary gear 162 and the second planetary gear 163 increases, and the respective planetary gears 162 and 163 revolve around the sun gear 161 while rotating around their own axis. As a result, the reverse operation force Fr is transmitted to the outer hub plate 110 and the inner hub plate 120 that pivotally support the first planetary gear 162, and is transmitted to the reverse drive force Tr that reversely rotates each of the hub plates 110 and 120 in the reverse direction. It will be converted (see FIG. 14 (a)).

In the wheelchair 1 of the present embodiment, the reverse operation force Fr given via the hand rim 22 is converted into the reverse drive force Tr by the reverse movement prevention unit 100 to rotate the main wheel 20 in the reverse direction. Therefore, the hand rim 22 can be operated in the same manner as a general wheelchair to move the vehicle body backward (see FIG. 14 (b)).

Next, with reference to FIG. 15, a case where a reverse rotation torque Wr that reversely rotates the outer hub plate 110 and the inner hub plate 120 of the reverse rotation prevention unit 100 acts in the reverse direction will be described. When the reverse rotation torque Wr acts on the outer hub plate 110 and the inner hub plate 120, the axis of the first planetary gear 162 (shaft member 162a) approaches the axis of the second planetary gear 163 (shaft member 163a). The relative rotation positions of the outer hub plate 110 and the inner hub plate 120 with respect to the outer operation plate 130 and the inner operation plate 140 are shifted. As a result, the reference pitch circles of the first planetary gear 162 and the second planetary gear 163 overlap each other, that is, the gears are engaged with each other, and the rotation of those gears is locked (FIG. 15 (FIG. 15). a) See).

Such reverse rotation torque Wr is often generated, for example, when the wheelchair 1 is on the slope or when the user transfers the weight to the wheelchair 1. In the wheelchair 1 of the present embodiment, even if the reverse rotation torque Wr acts on the main wheel 20, the rearward movement of the vehicle body is mechanically locked (see FIG. 15B). Therefore, even if the user releases his / her hand from the hand rim 22 on the slope, the wheelchair 1 does not move backward and is safe, and it is not necessary to continue the climbing operation until the slope is completely climbed. In addition, since the reverse movement is automatically mechanically locked, the user can safely transfer to the wheelchair 1.

1 Wheelchair 10 Body Frame 20 Main Wheel 21 Spoke 22 Hand Rim 23 Rigid Spoke 100 Reverse Prevention Unit 110 Outer Hub Plate 110A Gear Mounting Surface 112 Spoke Support Plate 113 Bolt 120 Inner Hub Plate 120A Gear Mounting Surface 122 Spoke Support Plate 130 Outer Operation Plate 137 Coil spring 140 Inner operation plate 150 Axle member 161 Sun gear 162 1st planetary gear 162a Shaft member 163 2nd planetary gear 163a Shaft member 200 Unlocking mechanism 210 Unlocking key plate 211 Unlocking key member 1101 Axle hole 1102 Bearing 1103 Hole 1104 Large Diameter Spacer 1107 Screw Hole 1201 Axle Hole 1202 Bearing 1203 Shaft Escape Hole 1204 Small Diameter Spacer 1301 Axle Hole 1302 Axle 1401 Axle Hole 1402 Axle Ff Forward Operation Force Fr Reverse Operation Force Tf Forward Drive Tr Reverse Drive Force Wr reverse rotation torque

Claims (2)

Axle members whose reference axis is their own axis,
A sun gear fixed to the axle member with the reference axis and the axis of the axle member aligned with each other.
A hub plate pivotally supported by the axle member in a manner rotatable about the reference axis, and
An operation plate pivotally supported by the axle member and arranged parallel to and facing the hub plate in a manner rotatable about the reference axis.
A first planetary that is pivotally supported by the hub plate in a manner rotatable around a first axis parallel to the reference axis and is arranged on the circumference of a first revolution radius centered on the reference axis. With gear,
A circumference of a second revolution radius that is pivotally supported by the operation plate and is smaller than the first revolution radius around the reference axis in a manner rotatable around the second axis parallel to the reference axis. It is provided with a second planetary gear that is arranged on top and meshes with the sun gear and the first planetary gear, respectively.
With respect to the line connecting the reference axis and the axis of the first planetary gear, the line connecting the reference axis and the axis of the second planetary gear is predetermined in the reverse rotation direction of the hub plate and the operation plate. Tilt at the angle of
The shaft member of the second planetary gear is formed in the hub plate and penetrates through a shaft relief hole having an inner diameter larger than the outer diameter of the shaft member, so that the operation plate rotates relative to the hub plate. The allowable angle range that can be moved is specified,
It is configured so that the meshing state between the first planetary gear and the second planetary gear changes according to the relative rotation position of the operation plate with respect to the hub plate.
Further, an initial stage in which the operation plate is constantly urged to rotate relative to the hub plate toward an initial position in the forward rotation direction in which the distance between the axes of the first planetary gear and the second planetary gear becomes smaller. A hub unit equipped with a position return means. A wheelchair including a chair-shaped body frame, drive wheels rotatably provided on the body frame via the hub unit according to claim 1, and a hand rim for operating the drive wheels. A wheelchair in which the axle member is supported and fixed to the axle mounting portion of the vehicle body frame, the spokes of the drive wheels are connected to the hub plate, and the hand rim is connected to the operation plate.

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