Wheelchair fixing device

Abstract

To provide a wheelchair fixing device capable of avoiding a fixing failure of a wheelchair caused by a malfunction that may occur at the fixing start of the wheelchair.SOLUTION: A wheelchair fixing device 1 in which a wire connected to a hook that is engaged with a wheelchair is taken up by driving motors 22F, 22R, and tension is applied to the wire to fix the wheelchair, includes: motor load detectors 12, 13 that detect the current values of the motors 22F, 22R; and a control unit 14 that executes fixing operation processing on the basis of the detected current values of the motors 22F, 22R. After a monitoring period has elapsed since the start of driving the motors 22F, 22R, if the current values detected by the motor load detectors 12, 13 exceed a threshold, the control unit 14 executes processing as the wheelchair has been properly fixed, and if the current values detected by the motor load detectors 12, 13 exceed the threshold during the monitoring period after the start of driving the motors, the control unit executes processing as the wheelchair has not been properly fixed.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a wheelchair fixing device.

Background Art

[0002] Conventionally, various techniques have been proposed for a wheelchair fixing device for fixing a wheelchair that has been brought into a vehicle such as an automobile (see, for example, Patent Document 1). The wheelchair fixing device described in Patent Document 1 fixes the wheelchair by hooking a hook to which a wire is connected on the wheelchair that has been brought into the vehicle, rotating a drum gear to wind up the wire, and applying tension to the wire. This drum gear rotates by meshing with an intermediate gear driven by a motor. Further, the intermediate gear is provided with a toothless portion on a part of its circumferential surface, and the drum gear is configured to idle with respect to the intermediate gear when facing this toothless portion. That is, since the drum gear rotates even without driving the motor, the user can manually pull out the wire. Thereby, it becomes easier for the user to perform the work of hooking the hook on the wheelchair or removing the hook hooked on the wheelchair.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the wheelchair fixing device described in Patent Document 1, when the drum gear rotates the intermediate gear from the idling state, the tip of the tooth of the intermediate gear and the tip of the tooth of the drum gear at the boundary with the toothless portion interfere with each other, and the intermediate gear and the drum gear may not mesh. In this case, there is a possibility that problems such as each gear not rotating or being difficult to rotate may occur.

[0005] An object of the present invention is to provide a wheelchair fixing device that can avoid poor fixation of a wheelchair due to problems that may occur at the start of fixing the wheelchair.

Means for Solving the Problems

[0006] A wheelchair fixing device according to an aspect of the present invention is a wheelchair fixing device that winds a flexible long member connected to a hook that hooks onto a wheelchair by driving a motor, and applies tension to the long member to fix the wheelchair, a load detection unit that detects the load of the motor, a control unit that can control the process related to the fixation of the wheelchair based on the load of the motor detected by the load detection unit, and includes the control unit has normal-time processing means that, after a predetermined monitoring period has elapsed since the drive of the motor was started, if the load detected by the load detection unit exceeds a predetermined threshold value, executes processing assuming that the wheelchair has been fixed normally, and abnormal-time processing means that, if the load detected by the load detection unit exceeds a predetermined threshold value during the monitoring period after the drive of the motor is started, executes processing assuming that the wheelchair has not been fixed normally.

[0007] A wheelchair fixing device according to an aspect of the present invention is a wheelchair fixing device that winds a flexible long member connected to a hook that hooks onto a wheelchair by driving a motor, and applies tension to the long member to fix the wheelchair, a load detection unit that detects the load of the motor, a control unit that controls the drive of the motor, an intermediate gear that rotates by the motor, a drum gear that rotates by meshing with the intermediate gear and winds up the long member, and includes the intermediate gear has a toothed portion formed with a plurality of teeth and a toothless portion where no teeth are formed along the circumferential direction, When the control unit starts driving the motor to rotate the intermediate gear in a state where the toothless portion faces the drum gear, the motor is driven at a duty ratio larger than the duty ratio in the steady state. When the load detection unit detects a load exceeding a predetermined threshold value, the motor is driven with the duty ratio set to the duty ratio in the steady state.

Advantages of the Invention

[0008] According to the present invention, it is possible to provide a wheelchair fixing device that can avoid defective fixation of a wheelchair due to problems that may occur at the start of fixing the wheelchair.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Embodiments for Carrying Out the Invention

[0010] Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

[0011] FIG. 1 is a diagram showing an example of a state where the wheelchair 10 is fixed by the wheelchair fixing device 1 in the vehicle 100. FIG. 2 is an explanatory diagram showing an example of a state where the wheelchair fixing device 1 is arranged in the vehicle 100. The wheelchair fixing device 1 is a device for fixing the wheelchair 10 to the floor of the vehicle 100 after, for example, a caregiver carries the wheelchair 10 into the vehicle 100, and is installed under the floor of the vehicle 100. FIG. 2 is a plan view of the floor of the vehicle 100 with the upper side of the paper being the front side of the vehicle 100. Members arranged under the floor are shown by dashed lines, and members arranged on the floor are shown by solid lines.

[0012] (Outline of the wheelchair fixing device 1) The wheelchair fixing device 1 has, for example, a hook 5 that hooks onto the wheelchair 10 and a wire 6 connected to the hook 5. The wheelchair fixing device 1 has a total of four hooks 5 and wires 6 each so that the hooks 5 can be hooked onto two places in the front and two places in the rear of the wheelchair 10. The hooks 5 and the wires 6 can be pulled out from the floor of the vehicle 100. Note that what is connected to the hook 5 is not limited to the wire 6, and for example, a rope or the like may be used. The above-mentioned "wire 6" corresponds to the "flexible long member" of the present invention.

[0013] The wheelchair fixing device 1 is provided with a front drive mechanism 2A and a rear drive mechanism 2B that wind up the wire 6. The front drive mechanism 2A is a mechanism that winds up two wires 6 connected to hooks 5 that are hooked on two locations in front of the wheelchair 10. The rear drive mechanism 2B is a mechanism that winds up two wires 6 connected to hooks 5 that are hooked on two locations behind the wheelchair 10. The front drive mechanism 2A and the rear drive mechanism 2B have the same configuration, and each is provided with motors 22F, 22R (see FIGS. 3 and 5 described later). The wheelchair fixing device 1 drives the front drive mechanism 2A and the rear drive mechanism 2B to wind up the wire 6 and applies tension to the wire 6 to fix the wheelchair 10.

[0014] FIG. 3 is a diagram showing an example of the configuration of the front drive mechanism 2A. As described above, since the front drive mechanism 2A and the rear drive mechanism 2B have the same configuration, only the configuration of the front drive mechanism 2A will be described below.

[0015] The front drive mechanism 2A has a base 21 that is fixed under the floor of the vehicle 100. On the base 21, for example, a front motor 22F and a pinion gear 23 are provided. The front motor 22F is a motor that can rotate forward and backward. The pinion gear 23 is, for example, a spur gear, and is connected to the rotation shaft of the front motor 22F and rotates by transmitting the torque of the front motor 22F.

[0016] On the base 21, for example, two intermediate gears 241, 242 are provided. The intermediate gears 241, 242 are, for example, spur gears. The intermediate gear 241 meshes with the pinion gear 23 and rotates, and the intermediate gear 242 meshes with the intermediate gear 241 and rotates.

[0017] FIG. 4(A) is a plan view showing an example of the intermediate gear 241, and FIG. 4(B) is a cross-sectional view taken along line IV-IV of FIG. 4(A). Since the intermediate gears 241, 242 have the same configuration, the intermediate gear 241 will be described here.

[0018] The intermediate gear 241 has a toothed portion 24A formed with a plurality of teeth and a toothless portion 24B without teeth along the circumferential direction. Specifically, the intermediate gear 241 has a plurality of teeth formed along the circumferential direction. And a part of the teeth is configured such that the upper half in the axial direction of the rotation axis (the upper half of the paper surface in Fig. 4(B)) is cut out. This cut-out portion becomes the toothless portion 24B. That is, on the outer peripheral surface of the intermediate gear 241, the toothed portion 24A and the toothless portion 24B are formed in the upper half in the axial direction of the rotation axis, and teeth are formed in the lower half in the axial direction of the rotation axis (the lower half of the paper surface in Fig. 4(B)) without providing a toothless portion.

[0019] With this configuration, the teeth formed in the lower half in the axial direction of the rotation axis (the lower half of the paper surface in Fig. 4(B)) of the intermediate gear 241 mesh with the pinion gear 23 and rotate. Also, the intermediate gears 241, 242 are configured such that the teeth formed in the lower half in the axial direction of the rotation axis mesh with each other and rotate. Thus, even though the intermediate gears 241, 242 have the toothless portion 24B without teeth, the torque of the front motor 22F is transmitted and they rotate without idling.

[0020] Returning to Fig. 3, for example, two drum gears 251, 252 are provided on the base 21. The drum gears 251, 252 are, for example, spur gears. The drum gear 251 meshes with the intermediate gear 241 and rotates, and the drum gear 252 meshes with the intermediate gear 242 and rotates. The drum gears 251, 252 mesh with the teeth in the upper half in the axial direction (the upper half of the paper surface in Fig. 4(B)) of the intermediate gears 241, 242 and do not interfere with the lower half in the axial direction (the lower half of the paper surface in Fig. 4(B)) of the intermediate gears 241, 242. Since the toothed portion 24A and the toothless portion 24B are provided in the upper half in the axial direction of the intermediate gears 241, 242, when the toothed portion 24A faces the drum gears 251, 252, the drum gears 251, 252 mesh with the intermediate gears 241, 242. When the toothless portion 24B faces the drum gears 251, 252, the drum gears 251, 252 do not mesh with the intermediate gears 241, 242.

[0021] Also, when the toothless portion 24B of the drum gear 251 and the intermediate gear 241 face each other, the toothless portion 24B of the drum gear 252 and the intermediate gear 242 also face each other. When the toothed portion 24A of the drum gear 251 and the intermediate gear 241 face each other, the toothed portion 24A of the drum gear 252 and the intermediate gear 242 also face each other. It is not the case that the toothless portion 24B of the drum gear 251 and the intermediate gear 241 face each other and, at the same time, the toothed portion 24A of the drum gear 252 and the intermediate gear 242 face each other. Similarly, it is not the case that the toothed portion 24A of the drum gear 251 and the intermediate gear 241 face each other and, at the same time, the toothless portion 24B of the drum gear 252 and the intermediate gear 242 face each other.

[0022] In this embodiment, a state where the toothless portion 24B of the drum gear 251 and the intermediate gear 241 face each other and the toothless portion 24B of the drum gear 252 and the intermediate gear 242 face each other is defined as the "initial state". In the initial state, the wheelchair 10 is not fixed to the floor of the vehicle 100. Also, in the initial state, torque from the front motor 22F is not transmitted to the drum gears 251, 252, and the user can manually pull out the wire. Then, when the operation receiving unit 11 (see FIG. 5 described later) receives an operation from the user (an operation for fixing the wheelchair 10 to the vehicle 100), the motors 22F, 22R rotate, the wire 6 is wound up, and the wheelchair 10 is fixed to the vehicle 100.

[0023] The drum gears 251, 252 are provided with drums (not shown). The drums are configured such that the rotation axes of the drums and the drum gears 251, 252 are movable axes and they rotate together with the drum gears 251, 252. For example, in FIG. 3, the drums are provided between the base 21 and the drum gears 251, 252. The drums are provided with grooves on their outer peripheral surfaces, and the wire 6 is wound around these grooves. The wire 6 wound by the drums is drawn out onto the floor of the vehicle 100 via the direction changing member 26. The direction changing member 26 functions as a member for changing the moving direction of the wire 6, and for example, a pulley, a cable guide, or the like is used.

[0024] The drum gears 251 and 252 are provided with a spring (not shown). When the wire 6 is sent out from the drum gears 251 and 252, an urging force (elastic force) is accumulated. When the wire 6 is wound around the drum, the accumulated urging force causes the drum gears 251 and 252 to rotate in the winding direction, and the wire 6 is wound around the groove on the outer peripheral surface of the drum, and the drum gears 251 and 252 rotate to the initial position.

[0025] FIG. 5 is an example of a block diagram for explaining the configuration of the wheelchair fixing device 1. The wheelchair fixing device 1 includes a front drive mechanism 2A, a rear drive mechanism 2B, an operation receiving unit 11, motor load detectors 12 and 13, and a control unit 14.

[0026] The front drive mechanism 2A has the configuration described with reference to FIG. 3. The rear drive mechanism 2B has the same configuration as the front drive mechanism 2A. The rear motor 22R provided in the rear drive mechanism 2B is the same as the front motor 22F provided in the front drive mechanism 2A.

[0027] The operation receiving unit 11 receives the operation of the wheelchair fixing device 1 by the user. The wheelchair fixing device 1 may be provided with an operation panel for the user to input an operation, or may be configured to receive an operation signal input by the user with an external device (for example, a portable device).

[0028] The motor load detector 12 detects the load (for example, current value) of the front motor 22F when driving the front drive mechanism 2A. The motor load detector 13 detects the load (for example, current value) of the rear motor 22R when driving the rear drive mechanism 2B. In this specification, for convenience of explanation, the front motor 22F and the rear motor 22R are referred to as motors 22F and 22R.

[0029] The motor load detectors 12 and 13 have current sensors that estimate the load by detecting the current flowing to the motors 22F and 22R. As the current sensor, a Hall effect sensor that detects current using the Hall effect in which the voltage difference generated in a conductor arranged perpendicular to the magnetic field in the current-carrying conductor is proportional to the magnitude of the current can be applied. When a Hall effect sensor is used, it can be a small-sized, high-precision, and high-speed response current sensor. Also, as the current sensor, a shunt resistor, which is a low-resistance resistor connected in series to the current conduction path, may be applied. In this case, the magnitude of the current, that is, the load of the motors 22F and 22R can be detected based on the voltage drop when the current passes through the shunt resistor and the resistance value of the shunt resistor. The above-mentioned "motor load detectors 12 and 13" correspond to the "load detection unit" of the present invention.

[0030] Note that the motor load detectors 12 and 13 are not limited to current sensors. For example, a torque sensor that detects the torque generated by the motors 22F and 22R by attaching a torque sensor to the output shafts of the motors 22F and 22R may be used. Also, the motor load detectors 12 and 13 may be encoders that detect the rotational speed of the motors 22F and 22R. In this case, since the rotational speed decreases as the load of the motors 22F and 22R increases, the load of the motors 22F and 22R can be grasped by detecting the change in the rotational speed with the encoder. Also, the motor load detectors 12 and 13 may be vibration sensors that detect the vibration generated by the motors 22F and 22R. In this case, by attaching the vibration sensor to the motors 22F and 22R and analyzing the change in vibration or the vibration pattern, the load of the motors 22F and 22R can be grasped. Furthermore, the motor load detectors 12 and 13 may be a combination of two or more of the above-mentioned detector elements such as current sensors, torque sensors, encoders, and vibration sensors.

[0031] The control unit 14 controls each functional part of the wheelchair fixing device 1 and executes a fixing operation process for fixing the wheelchair 10 to the floor of the vehicle 100. The control unit 14 includes, for example, a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and a timer, etc. The CPU reads out the program stored in the ROM to the RAM and executes it, thereby controlling each functional part of the wheelchair fixing device 1. Note that the above "fixing operation process" corresponds to the "fixing process" of the present invention.

[0032] (Fixing operation process of the wheelchair 10) The fixing operation process of the wheelchair 10 is started when the operation of the wheelchair fixing device 1 by the user is received. The control unit 14 operates the front drive mechanism 2A and the rear drive mechanism 2B in this order to execute the fixing operation process of the wheelchair 10. However, it is not limited to this, and the fixing operation process of the wheelchair 10 may be executed by operating the rear drive mechanism 2B and the front drive mechanism 2A in this order. Hereinafter, the fixing operation process of operating the front drive mechanism 2A to fix the wheelchair 10 to the vehicle 100 will be described as an example.

[0033] Incidentally, when the fixing operation process of the wheelchair 10 is started, the drum gears 251 and 252 may not mesh well with the intermediate gears 241 and 242. Similarly, the drum gears 252 and 252 may not mesh well with the intermediate gears 242 and 242. For example, taking the front drive mechanism 2A shown in FIG. 3 as an example and describing it in detail, when the fixing operation process is started, the driving of the front motor 22F is started. However, after the driving of the front motor 22F is started in the initial state, if the toothed portions 24A of the drum gears 251 and 252 face and mesh well with the toothed portions 24A of the intermediate gears 241 and 242, the driving force of the front motor 22F is transmitted to the drum gears 251 and 252 via the pinion gear 23 and the intermediate gears 241 and 242. However, when the driving of the front motor 22F is started in the initial state, for example, a tooth adjacent to the tooth missing portion 24B among the plurality of teeth of the toothed portion 24A (hereinafter referred to as "specific tooth 24A1") may interfere with the teeth of the drum gears 251 and 252 (hereinafter, the interference between the specific tooth 24A1 and the teeth of the drum gears 251 and 252 is referred to as "tooth tip interference"). The specific tooth 24A1 corresponds to the tooth that first meshes with the drum gears 251 and 252 when the driving of the front motor 22F is started. In the case of tooth tip interference, the current value of the front motor 22F detected by the motor load detector 12 exceeds a predetermined threshold value, and although the wheelchair 10 is not normally fixed to the floor of the vehicle 100, the control unit 14 may erroneously determine that the fixing is completed. Therefore, in the present embodiment, the processing executed by the control unit 14 can suppress the occurrence of such problems that may occur at the start of the fixing operation process of the wheelchair 10. Note that the same fixing operation process as that of the front drive mechanism 2A is executed for the rear drive mechanism 2B.

[0034] First, the concept of the fixing operation process of the present embodiment will be described with reference to FIGS. 6 and 7. FIG. 6 is a diagram showing an example of the relationship between the elapsed time since the driving of the motors 22F and 22R was started and the current value detected by the motor load detectors 12 and 13 (hereinafter simply referred to as the "current value"), where (A) is a diagram when the fixing operation process of the wheelchair 10 is normally performed, and (B) is a diagram when the fixing operation process of the wheelchair 10 is not normally performed (when an abnormality occurs during the fixing operation process). FIG. 7 is a diagram for explaining the concept of the fixing operation process in the present embodiment. In FIG. 7, an example of each case when the fixing operation process of the wheelchair 10 is normally performed (illustrated by a dashed line) and when the fixing operation process of the wheelchair 10 is not normally performed (illustrated by a solid line) is shown on the same graph. Note that the above "current value" corresponds to the "load of the motor detected by the load detection unit" of the present invention.

[0035] In FIGS. 6(A) and (B), T1 and t1 indicate when the driving of the motors 22F and 22R is started (hereinafter simply referred to as "motor start"). T2 and t2 indicate when the specific tooth 24A1 contacts the teeth of the drum gears 251 and 252 after the motor is started. T3 and t3 indicate when the current value reaches a predetermined threshold. T4 and t4 indicate when a predetermined motor stop condition is satisfied. The motor stop condition corresponds to, for example, the state where a certain time has elapsed after the current value reaches a predetermined threshold.

[0036] Also, the period A shown in FIG. 6(A) indicates the time from when the motor starts until the specific tooth 24A1 contacts the teeth of the drum gears 251 and 252. The period B indicates the time while the toothed portions 24A of the drum gears 251 and 252 and the intermediate gears 241 and 242 are in good mesh and the wire 6 is being pulled in to fix the wheelchair 10. The period C indicates the time while the wheelchair 10 is in a fixed state and the motor 22F and 22R are stopped with a restraint current flowing through them (i.e., in a state where the motors 22F and 22R have a driving force). When the motor stop condition is satisfied, the power supply for driving the motors 22F and 22R is cut off (i.e., the driving force is lost), and the motors 22F and 22R stop.

[0037] Also, in FIG. 6(B), the period a indicates the time from when the motor starts until the specific tooth 24A1 contacts the teeth of the drum gears 251 and 252. The period b indicates the period during which the current value rapidly increases during the process where the tooth tips interfere and the rotation of the intermediate gears 241 and 242 and the drum gears 251 and 252 stops. The period c indicates the time while the wheelchair 10 is not in a fixed state but the motors 22F and 22R are stopped with a restraint current flowing through them (i.e., in a state where the motors 22F and 22R have a driving force). When the motor stop condition is satisfied, the driving force of the motors 22F and 22R is lost, and the motors 22F and 22R stop.

[0038] In FIGS. 6(A) and 6(B), the periods A, B, C, a, b, and c are all simply denoted as A, B, C, a, b, and c.

[0039] As described above, comparing FIG. 6(A) when the fixing operation process of the wheelchair 10 is normally performed with FIG. 6(B) when the fixing operation process of the wheelchair 10 is not normally performed, the length of period B shown in FIG. 6(A) is different from the length of period b shown in FIG. 6(B). Therefore, it seems that after the motor is started, the time until the current value reaches a predetermined threshold can be measured to determine whether the fixing operation process of the wheelchair 10 is normally performed. However, since the rising timing of the current value varies depending on various conditions such as variations in the motor and ambient temperature, even if the time until the current value reaches a predetermined threshold is measured, it may not be possible to accurately determine whether the fixing operation process of the wheelchair 10 is normally performed.

[0040] Therefore, in the present embodiment, as shown in FIG. 7, a monitoring period is provided to determine whether the fixing operation process of the wheelchair 10 is normally performed. The monitoring period is set so as not to overlap with the normal region indicated by hatching in FIG. 7. The normal region is a predetermined period before and after including the timing at which the current value reaches a predetermined threshold when the fixing operation process of the wheelchair 10 is normally performed. That is, the monitoring period starts from the motor start and ends at a timing earlier (more specifically, earlier than the normal region) than when the current value reaches a predetermined threshold assuming that the fixing operation process of the wheelchair 10 is normally performed. Then, when the motor stop condition is satisfied after the monitoring period has elapsed, it is determined that the fixing operation process of the wheelchair 10 is normally performed, and when the motor stop condition is satisfied during the monitoring period, it is determined that an abnormality such as tooth tip interference has occurred. Therefore, it becomes possible to more accurately determine the problems that may occur at the start of fixing of the wheelchair 10.

[0041] (First Embodiment of Fixing Operation Process) Hereinafter, a first embodiment of the fixing operation process of the wheelchair 10 executed by the control unit 14 will be described with reference to FIG. 8. FIG. 8 is a flowchart showing a first embodiment of the fixing operation process of the wheelchair 10 executed by the control unit 14. In the first embodiment, the same process is executed by the front drive mechanism 2A and the rear drive mechanism 2B.

[0042] First, in step S1, the control unit 14 determines whether there is a motor drive instruction. In the process of this step S1, when the operation reception unit 11 receives the operation of the wheelchair fixing device 1 by the user, it is determined as YES as if there is a motor drive instruction. Although not shown in FIG. 8, when there is a motor drive instruction, the driving of the target motor is started. The target motor is the front motor 22F if it is the fixing operation process by the front drive mechanism 2A, and the rear motor 22R if it is the fixing operation process by the rear drive mechanism 2B.

[0043] The control unit 14 repeatedly executes the process of step S1 until a YES determination is made in step S1, and when a YES determination is made in step S1, the process proceeds to step S2.

[0044] In step S2, the control unit 14 executes a monitoring period timer process. This monitoring period timer process is a process for monitoring whether it is within the monitoring period. In the process of this step S2, during the monitoring period, the monitoring period flag is maintained in the ON state. That is, when the monitoring period flag is ON, it indicates that it is within the monitoring period. After executing the process of step S2, the control unit 14 proceeds the process to step S3.

[0045] In step S3, the control unit 14 determines whether the fixing completion determination is established. The fixing completion determination in step S3 does not determine whether the fixing operation process of the wheelchair 10 has been completed normally, but determines whether the current value has reached a predetermined threshold value. Therefore, even if the fixing operation process of the wheelchair 10 has not been completed normally, if the current value has reached the predetermined threshold value, it is determined as YES. In step S3, when the current value has not reached the predetermined threshold value, it is determined as NO, and the control unit 14 returns the process to step S2.

[0046] In step S4, the control unit 14 determines whether the monitoring period flag is ON. When the monitoring period flag is ON, the control unit 14 makes a YES determination and proceeds the process to step S5 assuming that the fixing operation process of the wheelchair 10 has not been completed normally.

[0047] On the other hand, in step S4, when the monitoring period flag is not ON, that is, when the monitoring period flag is OFF, the control unit 14 makes a NO determination and, assuming that the fixing operation process of the wheelchair 10 has been completed normally, transfers the process to step S6. However, it is not essential for the control unit 14 to execute the normal-time process in step S4. When a NO determination is made in step S4, the fixing operation process may be terminated (including the case where other processes different from the normal-time process are executed and then the fixing operation process is terminated). In this case, the user can determine that the fixing operation process has been completed normally based on the fact that the abnormal-time process has not been executed.

[0048] In step S5, the control unit 14 executes the abnormal-time process. The abnormal-time process corresponds to, for example, a process of returning to the initial state where the tooth missing part 24B and the drum gears 251, 252 face each other (that is, a process of rotating the target motor in the reverse direction), a process of stopping the drive of the target motor, etc. Thereby, the user can grasp that the fixing operation process has not been completed normally. In the abnormal-time process, in addition to these processes, other processes may be executed, such as outputting an alarm indicating that the fixing operation process of the wheelchair 10 has not been completed normally. After executing the process in step S5, the control unit 14 terminates the fixing operation process of the wheelchair 10.

[0049] In step S6, the control unit 14 executes the normal-time process. The normal-time process corresponds to, for example, a process of outputting a signal indicating that the fixing operation process has been completed normally to the outside, causing a predetermined light-emitting means (such as a lamp or an LED) to emit light, or outputting voice, etc. Thereby, the user can grasp that the fixing operation process has been completed normally. After executing the process in step S6, the control unit 14 terminates the fixing operation process of the wheelchair 10.

[0050] According to the first embodiment of such a fixing operation process, when the motor stop condition is satisfied after the monitoring period has elapsed, it is determined that the fixing operation process of the wheelchair 10 has been normally performed, and when the motor stop condition is satisfied during the monitoring period, it is determined that an abnormality such as tooth tip interference has occurred. In this way, it becomes possible to determine defects that may occur at the start of fixing the wheelchair, such as tooth tip interference. As a result, it is possible to avoid fixing defects of the wheelchair due to such defects.

[0051] (Second Embodiment of Fixing Operation Process) By the way, according to the first embodiment, although it is possible to provide a monitoring period and determine that an abnormality such as tooth tip interference has occurred when the motor stop condition is satisfied during the monitoring period, there are cases where it is not possible to safely determine whether the fixing operation process of the wheelchair 10 has been normally performed. Such a case will be described with reference to FIG. 9. FIG. 9 is a diagram for explaining the concept of the fixing operation process in the second embodiment. In FIG. 9, an example of each of the case where the fixing operation process of the wheelchair 10 is normally performed (illustrated by a broken line) and the case where the fixing operation process of the wheelchair 10 is not normally performed (illustrated by a solid line) is shown on the same graph.

[0052] As shown in FIG. 9, even if a monitoring period is provided and it is determined that an abnormality such as tooth tip interference has occurred when the motor stop condition is satisfied during the monitoring period, if the period α (simply denoted as α in FIG. 9) is short, there may be a case where it is not possible to safely determine whether the fixing operation process of the wheelchair 10 has been normally performed. Note that the period α corresponds to the time from when the monitoring period ends until the current value reaches a predetermined threshold value when the fixing operation process of the wheelchair 10 is normally performed.

[0053] As described above, the timing of the current value increase varies depending on various conditions such as variations in the motor and ambient temperature. Therefore, if the above time α is short, even though the fixing operation process of the wheelchair 10 is performed normally, there is a possibility that the current value reaches a predetermined threshold before the monitoring period ends. In this case, it may be erroneously determined that the fixing operation process of the wheelchair 10 is not performed normally. Therefore, in the second embodiment of the fixing operation process described later, as shown in FIG. 9, a determination time is provided to suppress the above-described erroneous determination.

[0054] Specifically, when the current value reaches a predetermined threshold within the monitoring period, if the time during which the current value is equal to or greater than the predetermined threshold continues within the monitoring period (hereinafter, this time is referred to as the "current holding time") reaches the determination time, even if the motor stop condition is satisfied, it is determined that an abnormality such as tooth tip interference has occurred. By doing so, it is possible to suppress an erroneous determination that may occur when the current value reaches a predetermined threshold during the monitoring period. The determination time is preferably equal to or longer than the time during which the inrush current flows when the motor is started and shorter than the determination time for the motor stop condition. Note that the above "current holding time" corresponds to the "specific time" of the present invention.

[0055] FIG. 10 is a flowchart showing a second embodiment of the fixing operation process of the wheelchair 10 executed by the control unit 14. FIG. 11 is a flowchart showing an example of the abnormality determination process shown in FIG. 10. This abnormality determination process is called as a subroutine during the execution of the fixing operation process of the wheelchair 10 shown in FIG. 10. In the second embodiment, the same process is executed for the front drive mechanism 2A and the rear drive mechanism 2B.

[0056] As shown in FIG. 10, the control unit 14 first executes an abnormality determination process in step S11. After executing the abnormality determination process, the control unit 14 moves the process to step S12. Hereinafter, before explaining the processes after step S12, the abnormality determination process will be described with reference to FIG. 11.

[0057] As shown in FIG. 11, in the abnormality determination process, the control unit 14 determines, in step S111, whether there is a motor drive instruction. The process of this step S111 is the same as the process of step S1 described in the first embodiment. The control unit 14 repeatedly executes the process of step S111 until a YES determination is made in step S111, and when a YES determination is made in step S111, the process proceeds to step S112.

[0058] In step S112, the control unit 14 activates the monitoring period timer. The monitoring period timer is a timer for measuring the above-described monitoring period. After executing the process of step S112, the control unit 14 proceeds to step S113.

[0059] In step S113, the control unit 14 determines whether the monitoring period has ended. If the monitoring period has ended, the control unit 14 makes a YES determination and proceeds to step S121. On the other hand, if the monitoring period has not ended yet, the control unit 14 makes a NO determination and proceeds to step S114.

[0060] In step S114, the control unit 14 determines whether the current value is equal to or greater than the threshold value. If the current value is equal to or greater than the threshold value, the control unit 14 makes a YES determination and proceeds to step S115. On the other hand, if the current value is not equal to or greater than the threshold value, that is, if the current value is less than the threshold value, the control unit 14 makes a NO determination and proceeds to step S117 described later.

[0061] In step S115, the control unit 14 determines whether the current maintenance timer has been activated. The current maintenance timer is a timer for measuring the above-described current maintenance time. If the current maintenance timer has been activated, the control unit 14 makes a YES determination and proceeds to step S117. On the other hand, if the current maintenance timer has not been activated, that is, if the current maintenance timer has not been started, the control unit 14 makes a NO determination and proceeds to step S116.

[0062] In step S116, the control unit 14 executes a process of starting the current maintenance timer. After starting the current maintenance timer, the control unit 14 transfers the process to step S117.

[0063] In step S117, the control unit 14 determines whether the current maintenance time has elapsed. If the current maintenance time has reached the above-mentioned determination time, a YES determination is made as if the current maintenance time has elapsed. On the other hand, if the current maintenance time has not reached the above-mentioned determination time, a NO determination is made as if the current maintenance time has not elapsed. When the current maintenance time has elapsed (in the case of a YES determination), the control unit 14 transfers the process to step S118. On the other hand, when the current maintenance time has not elapsed (in the case of a NO determination), the process returns to step S113, and the processes after step S113 are executed. Note that when an abnormality occurs in the fixing operation process of the wheelchair 10, that is, when a problem such as a tooth tip abnormality occurs, a YES determination is made in step S117.

[0064] When the control unit 14 determines in step S117 that the current maintenance time has elapsed (in the case of a YES determination), it executes current maintenance timer initialization (step S118) and monitoring period timer initialization (step S119), and then transfers the process to step S120.

[0065] In step S120, the control unit 14 sets the abnormality determination flag to ON. The abnormality determination flag is a flag indicating that the fixing operation process of the wheelchair 10 has not been performed normally, that is, an abnormality such as tooth tip interference has occurred. After executing the process of step S120, the control unit 14 ends the abnormality determination process and transfers the process to step S12 (see FIG. 10).

[0066] Return to step S113. When the control unit 14 determines in step S113 that the monitoring period has ended (in the case of a YES determination), it executes monitoring period timer initialization (step S121) and current maintenance timer initialization (step S122). When no abnormality has occurred in the fixing operation process of the wheelchair 10, a YES determination is made in step S113.

[0067] After the control unit 14 executes the processes of step S121 and step S122, it ends the abnormality determination process and transfers the process to step S12 (see FIG. 10).

[0068] In this way, by executing the process of step S117, it is possible to suppress the misjudgment that the fixing operation process of the wheelchair 10 has not been normally performed even though the fixing operation process of the wheelchair 10 has been normally performed.

[0069] Returning to FIG. 10, the control unit 14 determines in step S12 whether the fixing completion determination is established. The fixing completion determination is determined to be YES if a predetermined time has elapsed after the motor stop condition is established (see T4 and t4 in FIGS. 6(A) and (B)). This predetermined time is not before the monitoring period ends but at the timing after the monitoring period ends. The control unit 14 makes a YES determination when the fixing completion determination is established and transfers the process to step S13. Note that the control unit 14 repeatedly executes the process of step S12 until the fixing completion determination is established.

[0070] In step S13, the control unit 14 determines whether the abnormality determination flag is ON. When the abnormality determination flag is ON, the control unit 14 makes a YES determination and transfers the process to step S14, assuming that the fixing operation process of the wheelchair 10 has not been normally completed.

[0071] On the other hand, in step S13, when the abnormality determination flag is not ON, that is, when the abnormality determination flag is OFF, the control unit 14 makes a NO determination and proceeds with the process to step S15, assuming that the fixing operation process of the wheelchair 10 has been completed normally. However, it is not essential for the control unit 14 to execute the normal-time process in step S15. When a NO determination is made in step S13, the fixing operation process may be terminated (including the case where other processes different from the normal-time process are executed before terminating the fixing operation process). In this case, the user can determine that the fixing operation process has been completed normally based on the fact that the abnormal-time process has not been executed.

[0072] In step S14, the control unit 14 executes the abnormal-time process. In this abnormal-time process, the same process as the abnormal-time process executed in step S5 (see FIG. 8) of the first embodiment is performed.

[0073] In step S15, the control unit 14 executes the normal-time process. In this normal-time process, the same process as the normal-time process executed in step S6 (see FIG. 8) of the first embodiment is performed.

[0074] According to the second embodiment of such a fixing operation process, it is possible to determine defects that may occur at the start of fixing the wheelchair, such as tooth tip interference. In particular, when the current value reaches a predetermined threshold within the monitoring period and the current maintenance time reaches the determination time within the monitoring period, it is determined that an abnormality such as tooth tip interference has occurred. Therefore, it is possible to suppress false determinations that may occur when the current value reaches a predetermined threshold during the monitoring period.

[0075] Note that the normal-time processing executed in steps S6 and S15 corresponds to the processing executed by the "normal-time processing means" of the present invention "assuming that the wheelchair has been fixed normally". However, if the normal-time processing as shown in steps S6 and S15 is not executed, the processing of ending the fixing operation processing when a NO determination is made in steps S4 and S13 corresponds to the processing executed by the "normal-time processing means" of the present invention "assuming that the wheelchair has been fixed normally". In addition, the abnormal-time processing executed in steps S5 and S14 corresponds to the processing executed by the "abnormal-time processing means" of the present invention "assuming that the wheelchair has not been fixed normally".

[0076] (Modification example of the fixing operation processing) In the above-described first and second embodiments, in any of the embodiments, the same processing is executed by the front drive mechanism 2A and the rear drive mechanism 2B. However, the present invention is not limited to this, and different processing may be executed by the front drive mechanism 2A and the rear drive mechanism 2B.

[0077] For example, the front drive mechanism 2A may execute the fixing operation processing described in the first embodiment, and the rear drive mechanism 2B may execute the fixing operation processing described in the second embodiment. Also, the front drive mechanism 2A may execute the fixing operation processing described in the second embodiment, and the rear drive mechanism 2B may execute the fixing operation processing described in the first embodiment.

[0078] Furthermore, the front drive mechanism 2A may execute the fixing operation processing described in the first or second embodiment, and the rear drive mechanism 2B may execute a fixing operation processing different from both the first and second embodiments (including known fixing operation processing conventionally performed). Also, the front drive mechanism 2A may execute a fixing operation processing different from both the first and second embodiments (including known fixing operation processing conventionally performed), and the rear drive mechanism 2B may execute the fixing operation processing described in the first or second embodiment by the front drive mechanism 2A.

[0079] Even when adopting the modified example of the above-described fixing operation process, it is possible not only to determine an abnormality that may occur at the start of the fixing operation process such as tooth tip interference, but also to suppress a false determination that may occur when the current value reaches a predetermined threshold value during the monitoring period.

[0080] Further, when the control unit 14 executes the fixing operation process of the wheelchair 10 (see FIGS. 8 and 10), it is more preferable to execute the following fixing operation start-time process as the motor drive process immediately after the start of the fixing operation process.

[0081] Hereinafter, an example of the fixing operation start-time process of the wheelchair 10 executed by the control unit 14 will be described with reference to FIG. 12. FIG. 12 is a flowchart showing an example of the fixing operation start-time process of the wheelchair 10 executed by the control unit 14.

[0082] First, in step S21, the control unit 14 determines whether there is a motor drive instruction. In the process of step S21, when the operation reception unit 11 receives an operation of the wheelchair fixing device 1 by the user, it is determined as YES as if there is a motor drive instruction. Although not shown in FIG. 12, when there is a motor drive instruction, the drive of the target motor is started. The target motor is the front motor 22F if it is a fixing operation process by the front drive mechanism 2A, and the rear motor 22R if it is a fixing operation process by the rear drive mechanism 2B.

[0083] The control unit 14 repeatedly executes the process of step S21 until a YES determination is made in step S21, and when a YES determination is made in step S21, the process proceeds to step S22.

[0084] In step S22, the control unit 14 starts motor drive. At this time, as shown in FIG. 13, the control unit 14 starts motor drive with a 100% duty ratio. FIG. 13 is a diagram for explaining the concept of the fixing operation start-time process. In FIG. 13, the duty ratio of the motor drive that changes with the passage of time after starting the motor drive is shown.

[0085] In step S23, the control unit 14 determines whether the current value has reached a predetermined threshold. If the current value has reached the predetermined threshold, a YES determination is made, and the control unit 14 transfers the process to step S24. In step S23, if the current value has not reached the predetermined threshold, a NO determination is made, and the control unit 14 repeatedly executes the process of step S23.

[0086] In step S24, the control unit 14 reduces the duty ratio and drives the motor at a duty ratio V1 less than 100%. The duty ratio V1 is the duty ratio in the steady state. The duty ratio V1 in the steady state is, for example, 30%. As shown in FIG. 13, the control unit 14 controls the duty ratio to gradually decrease over time. Thereafter, the control unit 14 ends the process at the start of the fixed operation.

[0087] When the process at the start of the fixed operation ends, the control unit 14 executes the fixed operation process. The fixed operation process performed after the process at the start of the fixed operation ends is the same as that of the first embodiment or the second embodiment, except for the processes overlapping with the process at the start of the fixed operation, such as step S1 (see FIG. 8) and step S111 (see FIG. 11).

[0088] When the intermediate gear 241 starts to rotate slowly in the initial state, the tooth tips of the respective gears may interfere when the respective gears mesh. For this reason, in the process at the start of the fixed operation, when starting the motor drive from the initial state, the motor is driven at a duty ratio of 100% to rotate the intermediate gear 241 vigorously. Thereby, compared with the case where the motor is driven slowly, the tooth tip interference can be suppressed.

[0089] Note that the duty ratio when starting the motor drive in step S22 is preferably 100%, but it is not intended to exclude a duty ratio close to 100% such as 99%. The duty ratio when starting the motor drive in step S22 may be any duty ratio that is greater than the duty ratio V1 in the steady state and can suppress the tooth tip interference.

[0090] Also, in the above example, after the above-described fixed operation start-time process is completed, the same fixed operation process as that of the first embodiment or the second embodiment is executed, but the present invention is not limited thereto. For example, after the above-described fixed operation start-time process is completed, a fixed operation process different from those of the first embodiment and the second embodiment, including a conventional fixed operation process, may be executed.

[0091] As described above, the wheelchair fixing device according to an embodiment of the present invention has been described. The wheelchair fixing device of the above-described embodiment mainly includes the following configuration.

[0092] (1) In a wheelchair fixing device 1 that fixes the wheelchair 10 by driving motors 22F and 22R to wind up a flexible long member (for example, wire 6) connected to a hook that hooks onto the wheelchair 10 and applying tension to the long member (for example, wire 6), a load detection unit (for example, motor load detectors 12 and 13) that detects the load (for example, current value) of the motors 22F and 22R, and a control unit 14 that can control the process related to the fixing of the wheelchair 10 (for example, fixed operation process) based on the load (for example, current value) of the motors 22F and 22R detected by the load detection unit (for example, motor load detectors 12 and 13). The wheelchair fixing device 1 includes: The control unit 14 has a normal-time processing means that, after a predetermined monitoring period has elapsed since the driving of the motors 22F and 22R was started, if the load (for example, current value) detected by the load detection unit (for example, motor load detectors 12 and 13) exceeds a predetermined threshold value, executes a process (for example, normal-time process (step S6, step S15)) assuming that the wheelchair 10 has been fixed normally; and an abnormal-time processing means that, if the load detected by the load detection unit (for example, motor load detectors 12 and 13) exceeds a predetermined threshold value during the monitoring period after the driving of the motor is started, executes a process (for example, abnormal-time process (step S5, step S14)) assuming that the wheelchair has not been fixed normally. Wheelchair fixing device 1.

[0093] According to the wheelchair fixing device 1 of (1) above, if the timing when the load (for example, current value) detected by the load detection unit (for example, motor load detectors 12, 13) exceeds a predetermined threshold value is after a predetermined monitoring period has elapsed, it is considered that the fixing of the wheelchair 10 has been normally performed, and processing (for example, the process of ending the fixing operation process when a NO determination is made in step S4 and step S13) is executed. On the other hand, if the timing when the load (for example, current value) detected by the load detection unit (for example, motor load detectors 12, 13) exceeds a predetermined threshold value is during the predetermined monitoring period, it is considered that the fixing of the wheelchair 10 has not been normally performed (that is, an abnormality has occurred), and processing (for example, abnormality processing (step S5, step S14)) is executed. Therefore, it becomes possible to determine a problem that may occur at the start of fixing the wheelchair 10, such as tooth tip interference (for example, at the start of the fixing operation process). As a result, it is possible to avoid poor fixing of the wheelchair due to such problems.

[0094] (2) Intermediate gears 241, 242 rotated by the motors 22F, 22R, Drum gears 251, 252 that rotate by meshing with the intermediate gears 241, 242 and wind up the long member (for example, wire 6), Comprising, The intermediate gears 241, 242 have a toothed portion 24A formed with a plurality of teeth and a toothless portion 24B without teeth along the circumferential direction, The monitoring period starts when the driving of the motors 22F, 22R is started to rotate the intermediate gears 241, 242 in a state where the toothless portions 24B face the drum gears 251, 252, and ends at a timing before the load (for example, current value) detected by the load detection unit (for example, motor load detectors 12, 13) reaches the predetermined threshold value when it is assumed that the fixing of the wheelchair 10 has been normally performed. The wheelchair fixing device 1 described in (1) above.

[0095] According to the wheelchair fixing device 1 of (2) above, the monitoring period is from when the driving of the motors 22F and 22R starts until the timing before the load (for example, current value) detected by the load detection unit (for example, motor load detectors 12 and 13) reaches a predetermined threshold value when the fixing of the wheelchair 10 is normally performed. Therefore, it is possible to more accurately determine the defects that may occur at the start of fixing the wheelchair 10.

[0096] (3) If, during the monitoring period, the load detection unit continuously detects a load exceeding the threshold value for a predetermined determination time, the control unit executes the processing by the abnormal-time processing means (for example, abnormal-time processing (step S5, step S14)). The wheelchair fixing device 1 according to (1) or (2) above.

[0097] According to the wheelchair fixing device 1 of (3) above, it is possible to determine defects that may occur at the start of fixing the wheelchair 10, such as tooth tip interference. In particular, if, during the monitoring period, the load (for example, current value) detected by the load detection unit (for example, motor load detectors 12 and 13) continues to be detected for a time exceeding a predetermined determination time, it is assumed that the fixing of the wheelchair 10 was not performed normally (that is, an abnormality occurred), and processing (for example, abnormal-time processing (step S5, step S14)) is executed. Therefore, it is possible to suppress misjudgment that may occur when the load (for example, current value) detected by the load detection unit (for example, motor load detectors 12 and 13) reaches a predetermined threshold value during the monitoring period.

[0098] (4) In a wheelchair fixing device 1 that winds up a flexible long member (for example, wire 6) connected to a hook that hooks onto the wheelchair 10 by driving the motors 22F and 22R and applies tension to the long member (for example, wire 6) to fix the wheelchair 10, a load detection unit (for example, motor load detectors 12 and 13) that detects the load (for example, current value) of the motors 22F and 22R, a control unit 14 that controls the driving of the motors 22F and 22R, The drum gears 251 and 252 that rotate by meshing with the intermediate gears 241 and 242 and wind up the long member (for example, the wire 6), comprising, The intermediate gears 241 and 242 have a toothed portion 24A formed with a plurality of teeth and a toothless portion 24B not formed with teeth along the circumferential direction. The control unit 14, When starting the drive of the motors 22F and 22R to rotate the intermediate gears 241 and 242 in a state where the toothless portion 24B faces the drum gears 251 and 252, the motors 22F and 22R are driven at a duty ratio larger than the duty ratio V1 in the steady state. When the load detection unit (for example, the motor load detectors 12 and 13) detects a load (for example, the current value) exceeding a predetermined threshold, the motors 22F and 22R are driven at the duty ratio in the steady state. Wheelchair fixing device 1.

[0099] According to the wheelchair fixing device 1 of the above (4), the motor is started to be driven at a duty ratio larger than the duty ratio V1 in the steady state (for example, 100%), and at the timing when the load (for example, the current value) detected by the load detection unit (for example, the motor load detectors 12 and 13) exceeds a predetermined threshold, it is driven at the duty ratio V1 in the steady state. Thereby, when rotating the intermediate gears 241 and 242 from the state where the toothless portion 24B faces the drum gears 251 and 252, it is possible to suppress the tooth tip interference of each gear.

[0100] The wheelchair fixing device 1 according to the present invention may be configured only with the configuration described in the wheelchair fixing device 1 of the above (1), or may be an arbitrary combination of the configuration described in the above (1) and the configuration described in the above (2) or / and the above (3) within a range where alignment can be achieved. When combining the configuration described in the above (1) and the configuration described in the above (2) or / and the above (3), within a range where alignment can be achieved, all or part of the configuration described in the above (1) and all or part of the configuration described in the above (2) or / and the above (3) can also be combined.

[0101] As described above, those skilled in the art can conceive of various modifications and alterations within the scope of the idea of the present invention. Therefore, it is understood that those modifications and alterations belong to the scope of the present invention. For example, with respect to the above-described embodiments, those obtained by appropriately adding, deleting, or changing the design of components by those skilled in the art, or by adding, omitting, or changing the conditions of processes, are also included in the scope of the present invention as long as they have the gist of the present invention.

Description of Reference Numerals

[0102] 1 Wheelchair fixing device 2A Front drive mechanism 2B Rear drive mechanism 5 Hook 6 Wire 10 Wheelchair 11 Operation reception unit 12 Motor load detector 13 Motor load detector 14 Control unit 21 Base 22 Pinion gear 22F Front motor 22R Rear motor 23 Pinion gear 24A Toothed portion 24B Toothless portion 26 Pulley 100 Vehicle 241 Intermediate gear 242 Intermediate gear 251 Drum gear 252 Drum gear

Claims

1. A wheelchair fixing device that winds up a flexible long member connected to a hook for hooking on a wheelchair by driving a motor and applies tension to the long member to fix the wheelchair, a load detection unit that detects the load of the motor; a control unit that can control the processing related to the fixing of the wheelchair based on the load of the motor detected by the load detection unit; comprising: the control unit: normal-time processing means that, after a predetermined monitoring period has elapsed since the driving of the motor was started, if the load detected by the load detection unit exceeds a predetermined threshold value, executes processing assuming that the wheelchair has been fixed normally; abnormal-time processing means that, if the load detected by the load detection unit exceeds a predetermined threshold value during the monitoring period after the driving of the motor is started, executes processing assuming that the wheelchair has not been fixed normally, a wheelchair fixing device.

2. an intermediate gear rotated by the motor; a drum gear that rotates by meshing with the intermediate gear and winds up the long member; comprising: the intermediate gear has a toothed portion formed with a plurality of teeth and a toothless portion where no teeth are formed along the circumferential direction; the monitoring period starts when the driving of the motor is started to rotate the intermediate gear in a state where the toothless portion faces the drum gear, and ends at a timing earlier than when the load detected by the load detection unit exceeds the predetermined threshold value assuming that the wheelchair has been fixed normally. The wheelchair fixing device according to claim 1.

3. If the load detection unit continuously detects a load exceeding the threshold value for a predetermined determination time during the monitoring period, the control unit executes the processing by the abnormal-time processing means. The wheelchair fixing device according to claim 1 or claim 2.

4. A wheelchair fixing device that winds up a flexible long member connected to a hook for hooking on a wheelchair by driving a motor and applies tension to the long member to fix the wheelchair, a load detection unit that detects the load of the motor; a control unit that controls the driving of the motor; an intermediate gear rotated by the motor; a drum gear that rotates by meshing with the intermediate gear and winds up the long member; comprising: the intermediate gear has a toothed portion formed with a plurality of teeth and a toothless portion where no teeth are formed along the circumferential direction; the control unit: When starting the drive of the motor to rotate the intermediate gear in a state where the tooth missing part faces the drum gear, the motor is driven at a duty ratio larger than the duty ratio in the steady state, and when the load detection unit detects a load exceeding a predetermined threshold value, the motor is driven with the duty ratio set to the duty ratio in the steady state. Wheelchair fixing device.

Images