JPH09292293A - Human power detector of manufal type electric wheelchair - Google Patents

Abstract

PROBLEM TO BE SOLVED: To precisely detect only a circumferential human powder added to an input member. SOLUTION: In a human power detector for detecting the human power added to a hand rim (input member) 12 in a manual type electric wheelchair, the relative rotation of the hand rim 13 is transmitted to a rotating displacement transmitting member 21 radially engaged by slot with the hand rim 13, the relative rotation of the rotating displacement transmitting member 21 and a wheel 2 is converted into the axial displacement of a core 23 by a cam mechanism, the axial displacement of the core 23 is converted into the change quantity of self inductance of coils 24, 25 provided on the fixed side, whereby the human power is detected. Since the hand rim 13 is radially engaged by slot with the rotating displacement transmitting member 21, the axial displacement of the core 23 forming a differential transformer has no influence of a disturbance such as a horizontal force added to the hand rim 13, and only the circumferential human power added to the hand rim 13 can be precisely detected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a human power detection device for a manual electric wheelchair that applies auxiliary power corresponding to the amount of human power applied to the left and right wheels to each wheel to drive them to rotate.

[0002]

2. Description of the Related Art A manual electric wheelchair has been conventionally proposed as an intermediate existence between a manual wheelchair and an electric wheelchair. This manual electric wheelchair detects the human power applied to the left and right wheels intermittently and applies auxiliary power according to the detected human power to each wheel to reduce the physical burden on the occupant who cannot walk. According to this, the occupant can operate it like a manual wheelchair.

By the way, in such a manual electric wheelchair, for example, a hand rim which is an input member is elastically supported so as to be relatively rotatable bidirectionally with respect to a wheel, and a relative rotation amount between the hand rim and the wheel is connected by a wire. By transmitting it to a detecting means such as a potentiometer to detect it,
It detected the magnitude and direction of human power applied to the hand rim.

[0004]

However, in the above-mentioned conventional manual electric wheelchair, a detection means such as a potentiometer for detecting the relative rotation amount between the hand rim and the wheel is provided on the fixed side, and the hand rim and the wheel are separated from each other. Since the relative rotation amount was detected via the wire, the lateral force applied to the hand rim is also detected at the same time, and only the circumferential force (force to rotate the wheels) applied to the hand rim by the occupant is accurately detected. I couldn't.

The present invention has been made in view of the above problems, and an object of the present invention is to detect, with high precision, only human force in the circumferential direction (force to rotate a wheel) applied to an input member. (EN) Provided is a human power detection device for a manual electric wheelchair that can perform

[0006]

In order to achieve the above object, the invention according to claim 1 elastically supports an input member so as to be relatively rotatable bidirectionally with respect to a wheel, so that the human power input to the input member is In the human power detection device provided in a manual electric wheelchair, which detects based on the relative rotation amount of the input member and the wheel, and applies auxiliary power corresponding to the detected human power to the wheel to drive the rotation, Rotation of the core is transmitted to a rotational displacement transmitting member that engages with the input member in a radial hole, and relative rotation between the rotational displacement transmitting member and the wheel is converted into an axial displacement of the core by a cam mechanism. It is characterized in that human power is detected by converting the axial displacement into the amount of change in the self-inductance of the coil provided on the fixed side.

According to a second aspect of the present invention, in the first aspect of the present invention, the cam mechanism engages with the cam groove formed in the rotational displacement transmitting member and the cam groove provided in the core. It is constituted by a pin member and a dead zone in the circumferential direction is formed at the neutral point of the cam groove.

According to a third aspect of the present invention, in the first or second aspect of the invention, two coils are provided, and the human power is detected based on the difference in the amount of change in the self-inductance of the coils. .

According to a fourth aspect of the invention, in the invention of the third aspect, either the outer surface or the inner surface of the core is
A pair of salient poles are formed at positions separated from each other in the axial direction, and two coils are arranged so as to face each salient pole,
It is characterized in that the amount of change in the self-inductance of the two coils in each axial displacement of the core is such that one increases and the other decreases.

Therefore, according to the first or second aspect of the present invention, since the input member and the rotational displacement transmitting member are engaged with each other in the radial direction through the elongated holes, the axial displacement of the core constituting the differential transformer is prevented. Does not include the influence of disturbance such as lateral force applied to the input member, and can detect only the human force in the circumferential direction (force to rotate the wheel) applied to the input member with high accuracy.

According to the second aspect of the invention, since the dead zone is mechanically formed in the axial displacement of the core in the vicinity of the neutral point, the differential formed by the core and the coil is formed. The zero point of the transformer can be easily adjusted.

Further, according to the third or fourth aspect of the present invention, the amount of change in the self-inductance of the coil with respect to the axial displacement of the core constituting the differential transformer is amplified and detected, and is therefore added to the input member. The magnitude of human power can be detected with high sensitivity and high accuracy.

[0013]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a side view of a manual electric wheelchair equipped with a human power detecting device according to the present invention, and FIG. 2 is a plan view of the wheelchair.
3 is a rear view of the wheelchair, FIG. 4 is a front view showing a state in which a cover of a wheel hub portion of the wheelchair is removed, FIG. 5 is a cross-sectional view taken along the line AA of FIG. 4, and FIG. FIG. 7 is a detailed sectional view of a differential transformer constituting the human power detection device, FIG. 7 is a circuit configuration diagram of the human power detection device according to the present invention, FIG. 8 is a rear view of a hub portion of a wheel of a manual electric wheelchair, and FIG. Sectional drawing which shows the relative positional relationship of the core and the coil in a transformer, FIG.
FIG. 11 is a diagram showing a change of the self-inductance of the coil with respect to the core displacement amount, and FIG. 11 is a diagram showing a relationship of the core displacement amount with respect to the relative rotation amount between the hand rim and the wheel.

Manual electric wheelchair 1 according to the present embodiment
Is configured by detachably attaching wheels 2 that are drive wheels to the left and right of the body of an existing folding manual wheelchair, and the front and rear parts of a pipe frame-like frame 3 thereof are moved by a pair of left and right casters 4 and wheels 2. It is supported freely.

A cloth seat 5 (see FIGS. 2 and 3) on which an occupant should sit is stretched at the center of the frame 3. As shown in FIG. 3, the frame 3 has a pair of front and rear cross members 3a, and the two X-shaped cross members 3a are pivotally connected at their intersections by a shaft 6.

Further, a pair of left and right back pipes 3b are provided upright on the rear portion of the frame 3, and each back pipe 3b is provided.
The upper end of is bent backward, and a grip 7 for a helper is attached to the bent portion.

A pair of left and right elbow pipes 3c extending horizontally from the intermediate height position of the back pipe 3b of the frame 3 to the front of the vehicle body are bent at substantially right angles at their front ends to extend vertically downward, and their lower ends. The caster 4 is rotatably supported by the main switch 8 on the right side (right side for the occupant seated on the seat 5) of the elbow pipe 3c which is bent at a right angle (the upper part of the vertical part). ing. The front portion of the pair of left and right seat pipes 3d arranged below the elbow pipe 3c extends obliquely downward toward the front of the vehicle body, and a pair of left and right step 9 is formed at the extending end (front end portion). Is attached.

By the way, as shown in FIG. 5, each of the pair of left and right wheels 2 is rotatably supported via a ball bearing 12 on an axle 11 supported by a boss portion 10 welded to the frame 3. The outside of each wheel 2 is
A ring-shaped hand rim 13 is provided for the occupant to turn it by hand. The hand rim 13 is attached to a disc 14 rotatably supported by a boss 2a-1 formed on the hub 2a of the wheel 2 by means of bolts 16 via three spokes 15, Therefore, the hand rim 13 can rotate independently of the wheel 2. still,
In the present embodiment, as shown in FIG. 5, a seal ring 17 made of an elastic body is interposed between the hub 2a of the wheel 2 and the disc 14, and the disc 14 is bonded to this. It is covered by the cover 18. The seal ring 17 has a sealing function as well as a friction damper that suppresses vibration in the circumferential direction due to inertia of the disk 14.

The hand rim 13 is elastically supported by the structure shown in FIG. 4 so that the hand rim 13 is rotatable relative to the wheel 2 in both directions.

That is, as shown in FIG. 4, holes 14a having the same shape and the same size are formed at three positions of the disk 14, and springs 19 are compressed in the respective holes 14a. Each spring 19 is prevented from falling off by a holding member 20 fixed to the hub 2a. Therefore, the hand rim 13 attached to the disk 14 is elastically supported so as to be rotatable relative to the wheel 2 in both directions as described above.

Next, the human power detecting device according to the present invention will be described.

Since the relative rotation amount between the hand rim 13 and the wheel 2 is proportional to the magnitude of the human power (torque) applied to the hand rim 13, the human power detecting device according to the present invention is
The rotation of the hand rim 13 is transmitted to the rotational displacement transmitting member 21 shown in FIG.
The relative rotation between the wheel 1 and the wheel 2 is converted into an axial displacement of the cylindrical core 23 by the cam mechanism 22 shown in FIG. 6, and the axial displacement of the core 23 is divided into two coils (core and (Composed of a bobbin) 24 and 25 are converted into change amounts of self-inductances L1 and L2 and detected,
By calculating the difference, the amount of human power (torque) applied to the hand rim 13 is detected. Here, the core 23 and the coils 24 and 25 are composed of a core and a bobbin, these constitute a differential transformer, and the core 23 is composed of a ferromagnetic material.

Here, details of the configuration of the human power detection device are shown in FIG.
It will be described with reference to FIG.

As shown in FIG. 5, the rotational displacement transmitting member 21 is rotatably fitted and held on the outer periphery of the boss portion 2a-2 of the hub 2a of each wheel 2.
As shown in FIG. 6, cam grooves 26 are formed at two positions 1 and pins 27 attached to the core 23 are engaged with the respective cam grooves 26. Here, the cam groove 26 and the pin 27
Constitutes the cam mechanism 22, and the cam groove 26 is constituted to include grooves 26a and 26b formed obliquely in the axial direction, and a dead zone 26c in the circumferential direction is formed at its neutral point. ing.

On the other hand, as shown in FIGS. 4 and 5, a substantially ring-shaped plate 29 is rotatably fitted and held on the disk 14, and the plate 29 is formed at two positions in the circumferential direction. It is fixed to the disk 14 with a screw 30 through the long hole 29a. Then, as shown in FIG.
Two substantially rectangular holes 14b are formed at two positions of No. 4, and a long hole 29b in the radial direction formed in a part of the outer periphery of the plate 29 and a nut portion 29c are formed in the disk 14. It projects into the hole 14b.

The rotational displacement transmitting member 21 is engaged with the disk 14 through the plate 29 in a long hole and rotates integrally with the disk 14. That is, plate 2
A pin 31 protruding from a part of the outer periphery of the rotational displacement transmitting member 21 is tightly engaged in the elongated hole 29b formed in the circumferential direction with a large clearance in the radial direction. There is. The pin 31 can freely move in the radial direction with respect to the long hole 29b.

As shown in FIG. 4, an adjusting bolt 33 is screwed into the nut portion 29c formed on the plate 29 so that the adjusting bolt 33 can move forward and backward, and the tip portion of the adjusting bolt 33 is formed on the disk 14. It abuts on one inner wall of the formed hole 14b. By adjusting the adjusting bolt 33, the positional relationship between the disk 14 and the plate 29 in the circumferential direction is adjusted, and by this adjustment, the zero point of the human power detecting device is adjusted.
Then, after adjusting the zero point, the plate 29 and the disk 14 are fixed with the screw 30.

On the other hand, the core 23 is slidable in the axial direction (left and right direction in FIG. 5) on the outer periphery of the boss portion 2a-2 of the hub 2a of the wheel 2 and the rotational displacement transmitting member 21, and the wheel 2 (boss). It is fitted and held so as to rotate integrally with the portion 2a-2),
As shown in detail in FIG. 6, two recesses 23 are formed on the outer periphery thereof.
a are formed at appropriate intervals in the axial direction. Therefore, a convex portion 23b having a predetermined width is formed at the axially central portion of the outer periphery of the core 23.
Are formed relatively. The core 23 is biased inward (leftward in FIG. 5) by a spring (not shown) that is compressed between the core 23 and the rotational displacement transmitting member 21.

As shown in FIGS. 5 and 6, on the outer peripheral side of the core 23, the coils 24 and 25 arranged in two rows in the axial direction have a proper gap between them. It is provided and arranged. That is, the fixed plate 41 described later,
As shown in FIG. 5, a cylindrical holding member 34 is attached so as to cover the boss portion 2 a-2 of the hub 2 a of the wheel 2, and the coils 24 and 25 are provided on the inner peripheral side of the holding member 34. It is arranged and held in two rows in the direction.

FIG. 7 shows the configuration of a human power detection circuit including a differential transformer composed of the core 23 and the coils 24 and 25. In FIG. 7, 35 is a CPU built in a controller 42 described later, 36 is a transistor amplifier, 37 is a differential amplifier circuit, 38 is a sample hold circuit (S / H), and R1 and R2 are resistors.

By the way, as shown in FIGS. 5 and 8, a disc-shaped fixing plate 41 is attached to the axle 11 on the inner side in the vehicle width direction of each hub 2a of the pair of left and right wheels 2 and is fixed thereto. A controller 42, which constitutes a control means, is attached to the inside surface of the plate 41 in the vehicle body. Then, as shown in FIG. 8, a drive motor 43 and a wheel side coupler 44 are attached to the outer surface of the vehicle body of the fixed plate 41.

Further, a space surrounded by the fixed plate 41 is formed inside the hub 2a of each wheel 2, and the space is divided into a chamber S1 and a chamber S2 by a ring-shaped partition 44A. The controller 42 is housed in the chamber S1.

Thus, the auxiliary power generated by the drive motor 43 is transmitted to the wheels 2 via the power transmission means, which is the belt transmission mechanism G1 and the gear G.
2, G3 is included.

The human power detection device, the controller 42, the drive motor 43 and the power transmission means described above constitute an auxiliary power system. The auxiliary power system is the hub 2a of each wheel 2.
The wheels 2 are collectively arranged around the axle 11 in the radial direction and the axial direction, and the wheels 2 formed by arranging the auxiliary power system on the hub 2a have the same structure on the left and right sides. Each wheel 2 is detachably attached to the vehicle body.

By the way, in the manual electric wheelchair 1 according to the present embodiment, as shown in FIGS. 1 to 3, the battery holder 71 is fixed to the fixing plate 41 of the wheel 2 on the right side. A battery 45 is detachably attached to the battery holder 71, and a wire harness 46 is installed on the vehicle body (frame 3) side.

As described above, since the left and right wheels 2 have the same structure except the battery holder 71,
When these are attached to the vehicle body, they are arranged in a positional relationship that is point-symmetrical around the center of the vehicle body in the front-rear direction.

After the left and right wheels 2 are attached to the vehicle body, the coupler 44 attached to the fixed plate 41 of each wheel 2 is connected to the coupler 46A of the wire harness 46 installed on the vehicle body side ( (See FIG. 8), power is supplied from the battery 45 arranged on the right wheel 2 to the drive motor 43 and the controller 42 provided on the left wheel 2 via the wire harness 46.

Next, the operation of the manual electric wheelchair 1 will be described.

When the occupant applies a force to the pair of left and right hand rims 13 to rotate the wheel rims 13 to move the wheelchair 1 forward, the spring 1 interposed between the disk 14 and the hub 2a of the wheel 2 is rotated.
9 is compressed and deformed, and the compression reaction force of the spring 19 is transmitted to the hub 2a, so that human power is transmitted to the wheels 2.

Then, the rotation of the hand rim 13 is transmitted to the rotational displacement transmitting member 21 via the pin 31 engaging with the long hole 29b formed in the disc 14 and the plate 29,
The rotational displacement transmitting member 21 rotates relative to the wheel 2 (hub 2a) by an angle corresponding to the amount of compressive deformation of the spring 19, and the rotational displacement transmitting member 21 rotates relative to the cam mechanism 22.
Is converted into an axial displacement of the core 23. That is, as shown in FIG. 6, in the cam mechanism 22, the pin 27 is engaged with the dead zone 26c of the cam groove 26 from the neutral state (the state where no human power is input to the hand rim 13), and the hand rim 13 is moved forward. When rotated to the right, the oblique portion 26a of the cam groove 26 formed in the rotational displacement transmission member 21 is moved to the pin 2
A core 23 formed by attaching a pin 27 to engage with 7.
Moves in the direction of arrow a in FIG. 6, and the amount of movement (displacement amount) is proportional to the amount of human power applied to the hand rim 13.

When the occupant applies a force to the pair of left and right hand rims 13 to rotate the hand rims 13 in the opposite direction in order to move the wheelchair 1 backward, the rotation of the hand rims 13 causes the rotation displacement transmitting member 21 to rotate.
And the rotational displacement transmission member 21 is transmitted to the spring 19
Is rotated relative to the wheel 2 (hub 2a) in the opposite direction by an angle commensurate with the amount of compressive deformation, and the relative rotation of the rotational displacement transmitting member 21 is converted into an axial displacement of the core 23 by the cam mechanism 22. That is, as shown in FIG. 6, from the neutral state in which the pin 27 is engaged with the dead zone 26c of the cam groove 26 in the cam mechanism 22 (the state in which no human power is input to the hand rim 13), the hand rim 13 is moved backward. When rotated, the oblique portion 26b of the cam groove 26 formed in the rotational displacement transmitting member 21 engages with the pin 27, so that the core 23 formed by attaching the pin 27 moves in the direction of arrow b in FIG. The amount of movement (the amount of displacement) is proportional to the amount of human power applied to the hand rim 13.

Now, detection of human power by the human power detection device according to the present invention will be described.

In the neutral state where no human power is input to the hand rim 13, as shown in FIG.
The protrusions 23c and 23d formed at both axial ends of the coil 3 are located symmetrically with respect to the two coils 24 and 25.
The cores 4 and 25 and the convex portions 23c and 23d overlap each other in the axial direction by the same amount δ.

When moving forward, the core 23 is the coil 2
4, 25 in the direction of arrow a in FIG. 6 by a maximum of δ, at this time, as shown in FIG.
The amount of overlap with one convex portion 23d of the core of No. 25 is 2δ, and the amount of overlap with the other convex portion 23c is 0.

When the vehicle is moving backward, the core 23 has coils 24, 2
6 moves in the direction of arrow b in FIG. 6 by a maximum of δ, and at this time, as shown in FIG. 9 (c), the amount of overlap with one convex portion 23d of one of the cores of the coils 24 and 25 becomes 0. The amount of overlap with the other convex portion 23c is 2δ.

When the core 23 moves in the axial direction as described above in accordance with the amount of relative rotation between the hand rim 13 and the wheel 2 (magnitude of human power) during forward and backward movements, the self-inductance L1 of the coils 24 and 25 is increased. , L2 changes the transient currents i1, i2 shown in FIG. 7, and accordingly the resistors R1, R2.
The voltage drop (output voltage) due to 2 changes as shown by the broken line in FIG. Therefore, the magnitude of human power can be detected by detecting the output voltage of at least one of the coils 24 and 25, but in the present embodiment, the output voltage of both coils 24 and 25 is detected. There is.

By the way, in the present embodiment, one of the self-inductances L1 and L2 of the coils 24 and 25 in each axial displacement of the core 23 increases and the other decreases, so that the convex portions 23c and 23d of the core 23 are located. Are formed.

That is, the self-inductances L1 and L2 of the coils 24 and 25 respectively change with respect to the amount of displacement of the core 23, but the self-inductances L1 and L2 show mutually opposite characteristics. That is, L1 increases and L2 decreases as the displacement amount of the core 23 increases when moving forward, and L1 decreases and L2 increases when moving backward, so that each coil 2
The difference between the output voltages of 4 and 25 shows the amplified characteristics as shown by the solid line in FIG. Therefore, each coil 24, 25
If the difference in the output voltage of the core 23 is detected, the displacement of the core 23 and, by extension, the magnitude of the human power applied to the hand rim 13 are highly sensitive,
In addition, it can be obtained with high accuracy.

In the actual detection, in the detection circuit shown in FIG. 7, the CPU 35 outputs a rectangular pulse signal of a predetermined frequency to the transistor amplifier 36, and the transistor amplifier 36 amplifies the pulse signal and the coils 24 and 25.
A voltage that fluctuates periodically is applied to. Then, the transient currents i1 and i2 corresponding to the self-inductances L1 and L2 (see FIG. 10) determined with respect to the displacement of the core 23 flow in the coils 24 and 25, and the differential amplifier circuit 37 causes the voltage i1 × R1. , I2 × R2 difference (i1 × R1-i
A signal corresponding to 2 × R2) is output. This signal is sampled at a predetermined cycle by the sample hold circuit 38 and held during that cycle. The sample hold circuit 38 performs sampling according to the clock signal output from the CPU 35.

The signal held by the sample hold circuit 38 is then input to the CPU 35. Then
The CPU 35 determines the magnitude and direction of the human power applied to the hand rim 13 based on the signal proportional to the difference between the outputs of the self-inductances L1 and L2 of the coils 24 and 25.

In the human power detection described above, since the plate 29 rotating with the disk 14 and the rotational displacement transmitting member 21 are engaged in the long hole in the radial direction, the axial direction of the core 23 constituting the differential transformer is determined. Hand rim 13 for displacement
Does not include the effect of disturbance such as lateral force applied to
Only the human force in the circumferential direction (the force to rotate the wheel 2) applied to the hand rim 13 can be detected with high accuracy.

In the present embodiment, the zero adjustment at the neutral point of the differential transformer formed by the core 23 and the coils 24 and 25 is performed by rotating the adjustment bolt 33 shown in FIG. However, since the dead zone 26c in the circumferential direction is formed at the neutral point in the cam groove 26 that configures the cam mechanism 22, as shown in FIG. 11, it is proportional to the human power. Core 2 with respect to the amount of relative rotation between hand rim 13 and wheel 2
In the axial displacement of 3, the dead zone is mechanically formed near the neutral point, so that the zero point adjustment of the differential transformer can be easily performed.

When the human power is calculated by the CPU 35 as described above, the controller 42 sends a control signal corresponding to the magnitude of the human power to a power unit (not shown) to detect the human power (torque). The corresponding electric power (current) is supplied to the drive motor 43, and the drive motor 43 is rotationally driven to generate the required auxiliary power.

When the drive motor 43 is driven as described above, its rotation is transmitted to the wheel 2 through the power transmission means including the belt electric mechanism G1 and the gears G2 and G3, and the wheel 2 is manually operated. The wheelchair 1 is moved forward by a driving force of a magnitude obtained by adding auxiliary power to the wheelchair 1, and the occupant can comfortably operate the wheelchair 1 with a small human power, for example, about 1/2 of the total driving force. .

[0056]

As is apparent from the above description, claim 1
According to the invention described in claim 2, since the input member and the rotational displacement transmitting member engage with each other in the elongated hole in the radial direction, the axial displacement of the core forming the differential transformer is in the lateral direction applied to the input member. It is possible to obtain an effect that only the human force in the circumferential direction (the force to rotate the wheel) applied to the input member can be detected with high accuracy without including the influence of the disturbance such as the force.

Further, according to the second aspect of the present invention, since the dead zone is mechanically formed in the axial displacement of the core near the neutral point, the differential zone constituted by the core and the coil is formed. The effect that the zero point of the transformer can be easily adjusted is obtained.

Further, according to the third or fourth aspect of the present invention, since the amount of change in the self-inductance of the coil with respect to the axial displacement of the core constituting the differential transformer is amplified and detected, it is added to the input member. The effect that the magnitude of human power can be detected with high sensitivity and high accuracy can be obtained.

[Brief description of drawings]

FIG. 1 is a side view of a manual electric wheelchair including a human power detection device according to the present invention.

FIG. 2 is a plan view of a manual electric wheelchair including the human power detection device according to the present invention.

FIG. 3 is a rear view of a manual electric wheelchair including the human power detection device according to the present invention.

FIG. 4 is a front view showing a state in which a cover of a hub portion of a wheel of a manual electric wheelchair including a human power detection device according to the present invention is removed.

5 is a cross-sectional view taken along the line AA of FIG.

FIG. 6 is a detailed cross-sectional view of a differential transformer included in the human power detection device according to the present invention.

FIG. 7 is a circuit configuration diagram of a human power detection device according to the present invention.

FIG. 8 is a rear view of the hub portion of the wheel of the manual electric wheelchair including the human power detection device according to the present invention.

FIG. 9 is a sectional view showing a relative positional relationship between a core and a coil in a differential transformer.

FIG. 10 is a diagram showing a change in an output voltage of a coil with respect to a core displacement amount.

FIG. 11 is a diagram showing the relationship between the amount of core displacement and the amount of relative rotation between the hand rim and the wheel.

[Explanation of symbols]

 1 Manual Electric Wheelchair 2 Wheel 13 Hand Rim (Input Member) 19 Spring 21 Rotational Displacement Transmission Member 22 Cam Mechanism 23 Core 23a Core Recess 23b Core Convex 24, 25 Coil 26 Cam Groove 26c Cam Groove Dead Zone 27 Pin ( Pin member) 29 plate 29b long hole 31 pin L1, L2 coil self-inductance

Claims (4)

[Claims] 1. An input member is elastically supported so as to be rotatable relative to a wheel in both directions, and a human force input to the input member is detected based on a relative rotation amount between the input member and the wheel. A device provided in a manual electric wheelchair that applies auxiliary power according to human power to a wheel to drive the wheel in rotation, wherein the relative displacement of the input member is rotationally displaceable to engage the input member in a radial hole. To the member, the relative displacement between the rotational displacement transmitting member and the wheel is converted into an axial displacement of the core by a cam mechanism, and the axial displacement of the core is converted into a change amount of the self-inductance of the coil provided on the fixed side. A human power detection device for a manual electric wheelchair, which detects human power by converting. 2. The cam mechanism comprises a cam groove formed in the rotational displacement transmitting member and a pin member provided in the core and engaged with the cam groove, and a neutral point of the cam groove. The human power detection device for a manual electric wheelchair according to claim 1, wherein a dead zone in the circumferential direction is formed on the circumference. 3. The manual electric wheelchair according to claim 1, wherein two coils are provided, the amount of change in self-inductance of the coils is detected, and the human power is detected based on the difference. Human power detection device. 4. A pair of salient poles are formed at positions axially separated from each other on either the outer surface or the inner surface of the core, and two coils are arranged so as to face each salient pole. The human power detection device for a hand-operated electric wheelchair according to claim 3, wherein one of the two coils has a larger amount of change in self-inductance in each axial displacement, and the other has a smaller amount of change.