JP2020103553A - Contact sensor, seat for seating and wheelchair - Google Patents

Abstract

To provide a contact sensor that can increase durability in the real use, and provide a seat for seating with the contact sensor, and a wheelchair.SOLUTION: A contact sensor 10 is installed under a cushion member. A supporting point mechanism 12 is installed on a plate member 11b, and includes a line shape extending to the Y-direction. A plate member 11a is installed to face the plate member 11b across the supporting point mechanism 12 on the supporting point mechanism 12, and the tilt to the plate member 11b is changed by a seesaw structure using the supporting point mechanism 12 as a supporting point. A switch mechanism 13 is installed in one end 19a of 2-pieces of ends 19a, 19b serving as both ends of the plate members 11a, 11b sandwiching the supporting point mechanism 12 in the X direction, becomes a contact state in an initial state, and becomes a non-contact state when the plate member 11a is tilted to the end 19b side by the seesaw structure.SELECTED DRAWING: Figure 1

Description

The present invention relates to a contact sensor, a seat for seating, and a wheelchair, and, for example, to a technology of a contact sensor, a seat for seating, and a wheelchair used in the medical field, the care field, and the like.

For example, Patent Literature 1 discloses a biological information monitoring system that uses a bed leaving sensor installed under a mattress and monitors the leaving/bed presence of a subject based on each signal. The bed leaving sensor includes two plate-like members that are installed to face each other with an elastic member provided at each of four corners interposed therebetween, and a bed leaving detection switch that is installed in a central portion between the facing plate-like members. When the plate member is pressed, the bed leaving detection switch is turned on, and presence/absence of bed leaving is determined by turning on/off the bed leaving detection switch.

JP, 2017-60710, A

For example, in the medical field, the nursing field, and the like, it is required to detect the user (patient or care recipient) sitting out of a wheelchair. As the method, for example, it is possible to install a sensor as disclosed in Patent Document 1 under a cushion member in a wheelchair. The sensor is installed, for example, under the central portion of the cushion member or the like in order to reliably detect the seated state/seated state. However, in such a sensor, a large load is applied to the sensor in the seated state, which may reduce the durability of the sensor in actual use.

Further, in a sensor of the type that senses a load at the central portion of the seat surface as disclosed in Patent Document 1, the load is applied to the sensor through the cushion member when the user's body remains on even part of the seat surface. It will be. In this case, for example, even if the user's body moves to the front of the seat surface and falls into a dangerous state where it may slip off the seat surface, the danger cannot be sensed and the user's body is seated. Only when it falls off the surface will an abnormality be detected. That is, the sensor does not have a preventive effect even if early detection is possible with respect to slippage from the seat surface.

Therefore, one of the objects of the present invention is to improve the durability in actual use and to prevent the user from slipping off the seat surface, and a seat for seating equipped with the contact sensor. , To provide a wheelchair.

The above and other objects and novel features of the present invention will be apparent from the description of the present specification and the accompanying drawings.

The following is a brief description of the outline of a typical embodiment of the invention disclosed in the present application.

A contact sensor according to one embodiment is installed under a cushion member on which a user sits, and has first and second plate-shaped members, a fulcrum mechanism, and a switch mechanism. The fulcrum mechanism is installed on the first plate-shaped member and has a linear shape extending in the first direction within the plane of the first plate-shaped member. The second plate-shaped member is installed on the fulcrum mechanism so as to face the first plate-shaped member with the fulcrum mechanism interposed therebetween, and is inclined with respect to the first plate-shaped member by a seesaw structure having the fulcrum mechanism as a fulcrum. Changes. The switch mechanism has a first end that is both ends of the first and second plate-shaped members sandwiching the fulcrum mechanism in a second direction that intersects the first direction in the plane of the first plate-shaped member. It is installed at the first end of the second ends and is in a contact state in the initial state, and is in a non-contact state when the second plate member is inclined toward the second end side by the seesaw structure.

According to the one embodiment, in the contact sensor, the durability in actual use can be improved, and the contact sensor can be prevented from slipping off from the seat surface.

(A) is a plan view showing a structural example of the contact sensor according to the first embodiment of the present invention, and (b) and (c) are cross-sectional views showing a structural example between AA' in (a). Is. It is a perspective view showing the example of composition of the wheelchair to which the contact sensor of Drawing 1 (a)-Drawing 1 (c) is applied. (A) is a top view which shows an example of the installation place when installing the contact sensor of FIG. 1 (a)-FIG. 1 (c) in the wheelchair of FIG. 2, (b) and (c) are ( FIG. 7A is a cross-sectional view showing an example of a state around the contact sensor when the user is in a sitting state and a leaving state in a). FIG. 3A is a top view showing an example of an installation place different from that of FIG. 3A, and FIGS. 3B and 3C are views showing a state where the user is in a sitting state and a sitting state in FIG. It is sectional drawing which shows an example of the state around a contact sensor. It is sectional drawing which shows an example of the mounting form of each contact sensor of FIG. It is sectional drawing which shows the structural example different from FIG.1(b) between A-A' in FIG.1(a). (A) is a top view which shows the constructional example of the contact sensor by Embodiment 2 of this invention, (b) and (c) are sectional drawings which show the constructional example between BB' in (a). Is. (A) is a top view which shows an example of the installation location when installing the contact sensor of FIG.7(a)-FIG.7(c) in the wheelchair of FIG. 2, (b) and (c) is ( FIG. 7A is a cross-sectional view showing an example of a state around the contact sensor when the user is in a sitting state and a leaving state in a). (A) is a top view which shows the constructional example of the contact sensor which is a comparative example of this invention, (b) and (c) are sectional drawings which show the constructional example between CC' in (a). is there.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In all the drawings for explaining the embodiments, the same members are denoted by the same reference symbols in principle and their repeated description is omitted.

(Embodiment 1)
<<Structure of Contact Sensor (Embodiment 1)>>
1A is a plan view showing a structural example of a contact sensor according to Embodiment 1 of the present invention, and FIGS. 1B and 1C are AA′ in FIG. 1A. It is sectional drawing which shows the structural example between them. The contact sensor 10 shown in FIGS. 1A to 1C is installed under a cushion member on which a user sits, and includes plate members 11a and 11b, a fulcrum mechanism 12, and a switch mechanism 13. Each of the plate-shaped members 11a and 11b is, for example, a reinforced plastic or the like having a rectangular shape on the XY plane. In the specification, the X direction (length direction) is the in-plane direction (in the XY plane) of the plate-shaped member 11b, and the Y direction (width direction) is the in-plane direction (in the XY plane) of the plate-shaped member 11b. Is the direction intersecting the X direction. Further, the Z direction (height direction) is a direction intersecting with the surface (XY plane) of the plate-shaped member 11b.

The fulcrum mechanism 12 is installed on the plate-shaped member 11b and has a linear shape extending in the Y direction. The plate-shaped member 11a is installed on the fulcrum mechanism 12 so as to face the plate-shaped member 11b with the fulcrum mechanism 12 interposed therebetween, and the inclination with respect to the plate-shaped member 11b changes due to the seesaw structure having the fulcrum mechanism 12 as a fulcrum. It has a structure. Specifically, the fulcrum mechanism 12 includes, for example, a shaft rod 15 extending in the Y direction. The plate-shaped member 11a has a structure rotatable about the shaft rod 15 on the XZ plane. Further, as an example, the size (Ls) in the X direction (length direction) and the size (Ws) in the Y direction (width direction) of the contact sensor 10 are about 5 cm to 8 cm, and the Z direction (height direction). The size (Hs) of) is about 1.5 cm.

The switch mechanism 13 is installed at one end (referred to as a contact end) 19a of two ends 19a and 19b which are both ends of the plate-shaped members 11a and 11b with the fulcrum mechanism 12 interposed therebetween in the X direction. The switch mechanism 13 has two electrodes 17a and 17b installed on the two plate-shaped members 11a and 11b, respectively. The switch mechanism 13 is in a contact state (on state) in the initial state, and is in a non-contact state (off state) when the plate-shaped member 11a is inclined toward the other end (called a non-contact end) 19b by the seesaw structure. .. The two electrodes 17a and 17b are connected to the wirings 18a and 18b, respectively. Further, the contact sensor 10 includes an elastic member 14. The elastic member 14 is, for example, a spring, and is provided at a position between the fulcrum mechanism 12 and the non-contact end 19b and at a position between the plate-shaped members 11a and 11b.

With such a structure, in the plate-shaped member 11a, with the fulcrum mechanism 12 as the boundary 22, the region (XY plane) on the contact end 19a side of the boundary 22 becomes the ON region 20, and the non-contact end 19b side of the boundary 22 is formed. The area becomes the off area 21. As shown in FIG. 1B, when a larger load is applied to the ON region 20 than the OFF region 21 in the Z direction, or when the ON region 20 and the OFF region 21 have the same load, the plate-shaped member is formed. 11a and 11b maintain the initial state (substantially parallel state). As a result, the two electrodes 17a and 17b are brought into contact with each other, and the switch mechanism 13 is turned on.

On the other hand, as shown in FIG. 1C, when a larger load is applied to the off region 21 than the on region 20 in the Z direction, the plate-shaped member 11a has the non-contact end 19b based on the plate-shaped member 11b. Lean to the side. As a result, the two electrodes 17a and 17b are brought into a non-contact state, and the switch mechanism 13 is turned off.

Here, in the contact sensor 10, the distance L2 between the non-contact end 19b and the fulcrum mechanism 12 in the X direction is 1/2 to 5 times the distance L1 between the contact end 19a and the fulcrum mechanism 12, and for example, , And is equal to the distance L1. The contact sensor 10 uses the load difference due to the seesaw structure, and in particular, uses the transition of the switch mechanism 13 from the initial state (on state) to the off state due to the load on the off region 21. It is desirable to secure L2 to some extent.

At this time, if the distance L2 is too short with respect to the distance L1, in FIG. 1(c), the load on the off region 21 necessary for transitioning to the off state may become excessive, or the plate-shaped member 11a may have a large load. The tilt angle may be excessive. On the other hand, if the distance L2 is too long with respect to the distance L1, in FIG. 1C, the load on the off region 21 necessary for the transition to the off state may be too small, and the inclination of the plate member 11a may be too small. The angle may be too small. The ratio between the distance L1 and the distance L2 is determined in consideration of such a trade-off relationship. Further, the elastic member 14 is provided in order to reliably maintain the ON state (contact state) of the switch mechanism 13 in the initial state, and acts in the direction of bringing the electrodes 17a and 17b into contact with each other.

<<Application example of contact sensor to wheelchair>>
FIG. 2 is a perspective view showing a configuration example of a wheelchair to which the contact sensor of FIGS. 1(a) to 1(c) is applied. The wheelchair 25 shown in FIG. 2 has wheels 26 for moving the wheelchair 25, a cushion member 28 on which the user sits, a backrest 29 for supporting the user's back, and a seat surface 27 on which the cushion member 28 is mounted. The contact sensor is installed between the cushion member 28 and the seat surface 27 and detects, for example, when the user stands up from the wheelchair 25 or when the user falls off the wheelchair 25.

FIG. 3A is a top view showing an example of an installation location when the contact sensor of FIGS. 1A to 1C is installed in the wheelchair of FIG. 2, and FIGS. FIG. 3C is a cross-sectional view showing an example of a state around the contact sensor when the user is in a sitting state and a leaving state in FIG. 3A. In the example of FIG. 3A, two contact sensors 10[1] and 10[2] are installed between the cushion member 28 and the seat surface 27. Each of the two contact sensors 10[1] and 10[2] has a structure as shown in the contact sensor 10 of FIGS. 1(a) to 1(c).

In each of the contact sensors 10[1] and 10[2], the contact end 19a is on the outer peripheral side of the cushion member 28 and the non-contact end 19b is on the inner side of the cushion member 28 at a position below the outer peripheral portion of the cushion member 28. It is installed to face. Assuming that the straight traveling direction of the wheelchair is the X(Y) direction, the contact sensors 10[1] and 10[2] are located on both sides of the seat surface 27 of the wheelchair in the Y(X) direction intersecting the X(Y) direction. They are installed respectively, and are installed near the backrest 29 in the X(Y) direction.

As shown in FIG. 3B, when the user 30 is seated, in the switch mechanism 13 of the contact sensor 10, the load in the off region (non-contact end 19b side) is the load in the on region (contact end 19a side). Therefore, it is in an off state (non-contact state). On the other hand, as shown in FIG. 3C, when the user 30 is in the separated state, the switch mechanism 13 of the contact sensor 10 has a load in the off region (non-contact end 19b side) and an on region (contact end 19a side). ), the load is the same, so the state is the same as the initial state (contact state). As a result, the switch mechanism 13 of each of the contact sensors 10[1] and 10[2] in FIG. 3A has the user 30 based on the transition from the off state (non-contact state) to the on state (contact state). The fact that the user has left the cushion member 28 is detected.

Here, for example, it is assumed that the user 30 slightly changes his/her posture while sitting. In this case, the degree of bending of the cushion member 28 may slightly change according to the change in the posture. At this time, the switch mechanism 13 of the contact sensor 10 is in the off state as shown in FIG. 3B to the extent that the degree of flexure of the cushion member 28 slightly changes (the body position slightly changes) due to the seesaw structure. (Non-contact state) is still maintained.

That is, even if the distance between the electrodes (17a, 17b) changes with the change in the degree of bending of the cushion member 28, the switch mechanism 13 of FIG. The transition to the detached state is not detected unless a large change in Then, when the user 20 is completely separated from the wheelchair 25, the switch mechanism 13 is in an on state (contact state) as shown in FIG. 3C, and detects a transition to a sitting state. Thus, the use of the contact sensor 10 can reduce the possibility of erroneous detection due to a slight change in the posture of the user 30.

However, in FIG. 3A, for example, when the user 30 tilts his/her upper body laterally (on the side of the contact sensor 10[2]) while seated, the contact sensor 10[1] is There is a possibility of detecting the transition to the separated state (that is, erroneous detection) due to the on state (contact state) as shown in (c). Therefore, as described above, the contact sensors 10[1] and 10[2] are installed on both sides of the seat surface 27 of the wheelchair, respectively. In this case, at least one of the contact sensors 10[1] and 10[2] can maintain the off state (non-contact state) as shown in FIG.

Further, the contact sensors 10[1] and 10[2] are installed near the backrest 29, as described above. As a result, for example, it becomes possible to early detect a sign that the user 30 is slipping forward (the direction in which the wheelchair 25 advances straight). Specifically, when the sitting state of the user 30 is normal, a load is applied to the normal sitting area 31a shown in FIG. In this case, both of the contact sensors 10[1] and 10[2] can maintain the off state (non-contact state) as shown in FIG.

On the other hand, when the user 30 may move forward of the seat surface 27 and fall off the seat surface 27, a load is applied to the dangerous seating area 31b shown in FIG. In this case, the contact sensors 10[1] and 10[2] can be in the ON state (contact state) as shown in FIG. As a result, it becomes possible to detect a sign when the user 30 slips off the seat surface, and the caregiver and the like can take appropriate measures accordingly to prevent the user 30 slipping off the seat surface. It becomes possible to do.

FIG. 4A is a top view showing an example of an installation place different from that of FIG. 3A, and FIGS. 4B and 4C show that the user sits down in FIG. 4A. It is sectional drawing which shows an example of the state around a contact sensor at the time of a state and a detached state. In the example of FIG. 4A, the contact sensor 10[3] is installed between the cushion member 28 and the seat surface 27. The contact sensor 10[3] has a structure as shown in the contact sensor 10 of FIGS. 1(a) to 1(c).

The contact sensor 10[3] is located below the outer peripheral portion of the cushion member 28, and the contact end 19a is on the outer peripheral side of the cushion member 28, as in the case of the contact sensors 10[1] and 10[2] described above. The non-contact end 19b is installed so as to face the inside of the cushion member 28. When the straight traveling direction of the wheelchair is the X(Y) direction, the contact sensor 10[3] is installed near the middle on the seat surface 27 in the Y(X) direction intersecting the X(Y) direction, and the contact sensor 10[3] is installed in the X(Y) direction. It is installed near the backrest 29 in the direction.

By using the contact sensor 10 [3] installed near the backrest 29, for example, the user 30 is forward (in the straight-ahead direction of the wheelchair 25) as in the case of the contact sensors 10 [1] and 10 [2] described above. It is possible to detect early signs that are falling into the range. However, for example, in the case of a folding wheelchair 25 or the like in which both sides of the seat surface 27 are fixed, when the user 30 sits down, on the backrest 29 side of the seat surface 27, the middle portion thereof is based on both sides. Depression-like bending may occur. In this case, for example, a force in a direction different from the movable direction (a force that bends toward the Y(X) axis direction) is applied to the contact sensor 10[3], which may damage the contact sensor 10[3]. There is.

From the above, for the wheelchair 25, first, as shown in FIG. 3A, the contact sensors 10[1] and 10[2] are provided near the backrest 29 on both sides of the seat surface 27. It is desirable to place them. Further, when the contact sensor 10 has sufficient strength against a force in a direction different from the movable direction as described above, in addition, as shown in FIG. 4A, the contact sensor 10 contacts the backrest 29 side. It is more desirable to arrange the sensor 10 [3].

<<Method of judging the detection result of contact sensor>>
The wirings (18a, 18b) from the contact sensors 10[1] to 10[3] shown in FIGS. 3A and 4A are connected to a control unit (not shown). The control unit determines the on/off state of the switch mechanism 13 of each of the contact sensors 10[1] to 10[3] based on, for example, the presence/absence of current conduction, and the determination result is transmitted via a wireless signal or the like. Notify outside. At this time, the control unit may perform an AND operation on the ON state (that is, the separated state) of the switch mechanism 13 of each of the contact sensors 10[1] to 10[3], and notify the outside of the AND operation result. .. In this case, it is possible to detect that the user 30 has reliably left.

Further, the control unit may perform an OR operation on the ON state (that is, the separated state) of the switch mechanism 13 of each of the contact sensors 10[1] to 10[3], and notify the result of the OR operation to the outside. For example, when only some of the switch mechanisms 13 are in the ON state, the user 30 may have an unnatural posture on the cushion member 28 including a slip. In this case, since the OR operation result is “1” and the AND operation result is “0”, it is possible to detect the sign that the user 30 deviates from the seat surface 27 or the like by the combination.

<<Mounting form of contact sensor>>
FIG. 5: is sectional drawing which shows an example of the mounting form of each contact sensor of FIG. FIG. 5 shows a contact sensor device 35 including two contact sensors 10[1] and 10[2] and a cover member 36 that covers the two contact sensors 10[1] and 10[2]. Be done. The cover member 36 is, for example, a member having flexibility or elasticity, and the distance Wc between the two contact sensors 10[1] and 10[2] is a predetermined value (e.g., equal to the width of the cushion member 28). Specified in. Further, the cover member 36 has a degree of bending that allows the inclination of the plate-shaped member due to the off state (non-contact state) of the contact sensors 10[1] and 10[2]. By using such a contact sensor device 35, the installation of the contact sensors 10[1] and 10[2] as shown in FIG. 3A can be facilitated.

Further, the two contact sensors 10[1] and 10[2] may be integrated in advance under the cushion member 28 in the form of a seating seat with a sensor. The seat for seating is not limited to the wheelchair 25 and can be applied to various chairs used in the fields of medical care, nursing care, and the like. Further, the two contact sensors 10[1] and 10[2] may be integrated in advance on the seat surface 27 in the form of a wheelchair 25 with a sensor.

<<Structure of contact sensor (modification)>>
FIG. 6 is a cross-sectional view showing a structural example between AA′ in FIG. 1A different from FIG. 1B. In the initial state, the plate-shaped member 11a is parallel to the plate-shaped member 11b as shown in FIG. 1(b), or tilted toward the non-contact end 19b side at an angle θ as shown in FIG. Is installed in. If the plate-shaped member 11a is installed so as to incline toward the contact end 19a side instead of the non-contact end 19b side in the initial state, for example, when the user 30 is in the separated state as shown in FIG. Since the load of 28 is not evenly applied and biased toward the non-contact end 19b side, the switch mechanism 13 may not be able to maintain the ON state (contact state).

On the other hand, when the plate member 11a is installed so as to be parallel to the plate member 11b or inclined to the non-contact end 19b side at an angle θ in the initial state, the user 30 is separated as shown in FIG. In the seated state, the load of the cushion member 28 is evenly applied or biased toward the contact end 19a, so that the switch mechanism 13 can maintain the ON state (contact state). However, if the angle θ becomes excessively large, the switch mechanism 13 may not be turned off (non-contact state) in the seated state as shown in FIG. 3B, and the electrode mechanism may not be set in the separated state in FIG. 3C. An excessive force may be applied to (17a, 17b). Therefore, the angle θ is set to, for example, 0°≦θ≦10°.

Here, when the cushion member 28 is mounted on the contact sensor 10 and the angle θ is 10°, it is possible to reliably maintain the ON state (contact state) of the switch mechanism 13. However, the certainty thereof decreases as the angle θ approaches 0° (the plate-like members 11a and 11b become closer to each other in parallel). Therefore, it is useful to provide the elastic member 14 having the reaction force P in the direction of turning on the switch mechanism 13 (contact state). According to the study by the present inventor, for example, the reaction force P required when the angle θ is 10° is 0 [kgf] or more, and the reaction force P required when the angle θ is 0° is 0.1. It is not less than [kgf]. When the relationship between the angle θ (0°≦θ≦10°) and the reaction force P is regarded as a linear relationship, the reaction force P and the angle θ satisfy the relationship of the expression (1).
P≧(0.1−θ/100) (1)

<<Structure and Problems of Contact Sensor (Comparative Example)>>
FIG. 9A is a plan view showing a structural example of a contact sensor as a comparative example of the present invention, and FIGS. 9B and 9C are views between CC′ in FIG. 9A. 3 is a cross-sectional view showing a structural example of FIG. The contact sensor 10′ shown in FIGS. 9A to 9C includes plate members 11a′ and 11b′, a switch mechanism 13′, and an elastic member 14′. The plate-shaped members 11a' and 11b' are installed to face each other with the elastic members 14' provided at the four corners sandwiched therebetween. The switch mechanism 13' includes electrodes 17a' and 17b' installed in the central portion between the plate-shaped members 11a' and 11b' facing each other. As shown in FIG. 3C, when a certain amount of load is applied to the plate-shaped member 11a' from the Z direction, the switch mechanism 13' is brought into contact with the electrodes 17a' and 17b' to be turned on.

Therefore, for example, when the contact sensor 10′ is installed at a position such as the contact sensors 10[1] and 10[2] shown in FIG. 3A, the condition under which the switch mechanism 13′ is in the ON state is The material may vary depending on the material of the cushion member 28. For example, even in the seated state as shown in FIG. 3B, the switch mechanism 13′ is in the ON state (seated state if the load transmitted from the Z direction via the cushion member 28 to the plate member 11a′ is insufficient. It does not become a detected state). Therefore, the contact sensor 10 ′ of the comparative example usually needs to be installed in the central portion of the cushion member 28 in order to improve the detection accuracy.

<<Main effects of the first embodiment>>
On the other hand, the contact sensor 10 of the first embodiment is a method of detecting the magnitude relationship between the load of the on-region 20 and the load of the off-region 21 based on the seesaw structure. In the seated state as shown in FIG. 3B, in the contact sensor 10, the load in at least the off region (non-contact end 19b side) is in the on region (contact end 19a side) regardless of the material of the cushion member 28 and the like. A state larger than the load is established. Along with this, the plate-shaped member 11a is tilted toward the non-contact end 19b, and the switch mechanism 13 is turned off (state where seating is detected). Therefore, unlike the case of the comparative example, the contact sensor 10 of the first embodiment can be installed on the outer peripheral portion of the cushion member 28 as shown in FIG.

As a result, as a first effect, it becomes possible to enhance durability in actual use. More specifically, as described above, the contact sensor 10 can be installed at the outer peripheral portion of the cushion member 28 instead of the central portion as in the comparative example. In the seated state, the load applied to the contact sensor is smaller in the outer peripheral portion than in the central portion, so that the durability can be improved. As a result, the contact sensor 10 can be handled as a durable component rather than a consumable component, and as described in FIG. 5, the contact sensor 10 can be fixedly incorporated into a seat for seating, a seat surface 27 of a wheelchair, or the like. become.

As a second effect, the contact sensor 10 can be arranged on the outer peripheral portion of the cushion member 28, and the dependency of the detection sensitivity on the material of the cushion member 28 and the like can be reduced, so that FIG. 3A and FIG. By appropriately setting the installation location of the contact sensor 10 as described above, it is possible to detect a sign when the user 30 is displaced from the seat surface 27 at low cost. That is, for example, use an expensive analog sensor or the like that detects the degree of load in an analog manner, or use a large number of contact sensors 10' of the comparative example and spread them over the entire seat surface in a matrix. Without this, it becomes possible to prevent the user 30 from slipping off the seat surface 27.

As a third effect, the contact sensor 10 having high versatility can be realized. More specifically, since it is possible to reduce the dependency of the detection sensitivity on the material of the cushion member 28 and the like, the contact sensor 10 can be combined with various types of cushion members 28. Further, since the detection result of the contact sensor 10 is only in the ON state or the OFF state, the control unit that processes the detection result of the contact sensor 10 does not require special processing, and various widely existing control units are used. You can

(Embodiment 2)
<<Structure of Contact Sensor (Second Embodiment)>>
FIG. 7A is a plan view showing a structural example of the contact sensor according to the second embodiment of the present invention, and FIGS. 7B and 7C are BB′ in FIG. 7A. It is sectional drawing which shows the structural example between them. The contact sensor 40 shown in FIGS. 7A to 7C is different from the contact sensor 10 shown in FIGS. 1A to 1C in the following three points. The first difference is that the switch mechanism 43 (the electrodes 47a and 47b) of the contact sensor 40 is initially in a non-contact state (off state), and the plate-shaped member 11a is inclined toward the contact end 19a by the seesaw structure. When it is touched, it becomes a contact state (ON state).

According to the difference in this initial state, as a second difference, the elastic member 44 is provided at a position between the fulcrum mechanism 12 and the contact end 19a and at a position between the plate-shaped member 11a and the plate-shaped member 11b. And the electrodes 47a and 47b do not come into contact with each other. The third difference is that the distance L3 between the non-contact end 19b and the fulcrum mechanism 12 in the X direction is shorter than the distance L1 between the contact end 19a and the fulcrum mechanism 12, and is, for example, 1/2 or less. is there.

As shown in FIG. 7B, when a load larger than that in the on region 20 is applied to the off region 21 in the Z direction, or when the loads in the off region 21 and the on region 20 are equal, the plate-shaped member 11a and 11b maintain the initial state (substantially parallel state). As a result, the two electrodes 47a and 47b are brought into a non-contact state, and the switch mechanism 43 is turned off. Strictly speaking, in the state as shown in FIG. 7B, the plate-shaped member 11a may tilt toward the non-contact end 19b side, and therefore the contact sensor 40 prevents the tilt toward the non-contact end 19b side. It is desirable to separately provide the above mechanism.

On the other hand, as shown in FIG. 7C, when a larger load is applied to the on region 20 than the off region 21 in the Z direction, the plate-shaped member 11a moves toward the contact end 19a side with respect to the plate-shaped member 11b. Lean on. As a result, the two electrodes 47a and 47b are brought into contact with each other, and the switch mechanism 43 is turned on.

Here, as described above, in the contact sensor 40, the distance L3 is, for example, half or less of the distance L1. The contact sensor 40 differs from the contact sensor 10 of FIGS. 1A to 1C in that the switch mechanism 43 is changed from the initial state (OFF state) to the ON state particularly with the load on the ON region 20. It is used to transition to. Therefore, the distance L3 may be short, for example, in order to reduce the size of the contact sensor 40.

<<Application example of contact sensor to wheelchair>>
FIG. 8A is a top view showing an example of an installation location when the contact sensor of FIGS. 7A to 7C is installed in the wheelchair of FIG. 2, and FIGS. FIG. 8C is a cross-sectional view showing an example of a state around the contact sensor when the user is in a sitting state and a leaving state in FIG. 8A. In the example of FIG. 8A, three contact sensors 40[1] to 40[3] are installed between the cushion member 28 and the seat surface 27. Each of the three contact sensors 40[1] to 40[3] has a structure as shown in the contact sensor 40 of FIGS. 7(a) to 7(c).

The three contact sensors 40[1] to 40[3] are installed at the same positions as the contact sensors 10[1] to 10[3] shown in FIGS. 3A and 4A, respectively. However, in each of the three contact sensors 40[1] to 40[3], unlike the case of FIG. 3(a) and FIG. 4(a), the contact end 19a is on the inner side of the cushion member 28 and there is no contact. The end 19b is installed so as to face the outer peripheral side of the cushion member 28.

As shown in FIG. 8B, when the user 30 is seated, the load of the switch mechanism 43 of the contact sensor 40 in the ON region (contact end 19a side) is in the OFF region (non-contact end 19b side). Since it is larger than the above, it is in an ON state (contact state). On the other hand, as shown in FIG. 8C, when the user 30 is in the separated state, the switch mechanism 43 of the contact sensor 40 has the load in the ON region (contact end 19a side) and the OFF region (non-contact end 19b side). ), the load is the same, so the state is the off state (non-contact state) as in the initial state. Thereby, the switch mechanism 43 of each of the contact sensors 40[1] to 40[3] in FIG. 8A is different from the case of FIG. 3A and FIG. 4A in the ON state (contact state). It is detected that the user 30 has left the cushion member 28 based on the transition to the off state (non-contact state).

<<Main Effects of Second Embodiment and Comparison with First Embodiment>>
Similarly to the case of the first embodiment, the contact sensor 40 of the second embodiment is also a method of detecting the magnitude relationship between the load of the on-region 20 and the load of the off-region 21 based on the seesaw structure. In the seated state as shown in FIG. 8B, in the contact sensor 40, the load of at least the on region 20 (contact end 19a side) is off region 21 (non-contact end 19b side) regardless of the material of the cushion member 28 and the like. ) Load is built up. Along with this, the plate-shaped member 11a is tilted toward the contact end 19a, and the switch mechanism 43 is turned on (a state where seating is detected). Therefore, the contact sensor 40 of the second embodiment can also be arranged on the outer peripheral portion of the cushion member 28, as in the case of the first embodiment.

As a result, by using the contact sensor 40 of the second embodiment, the same effects as the first, second and third effects described in the first embodiment can be obtained. However, regarding the dependence of the detection sensitivity on the material and the like of the cushion member 28 described in the second and third effects, the use of the contact sensor 10 of the first embodiment provides a more beneficial effect.

More specifically, the switch mechanism 43 in FIG. 8B has, for example, a gap between the electrodes (47a, 47b) in accordance with a change in the posture of the user 30 in the sitting state (a change in the degree of bending of the cushion member 28). When the distance changes even a little (when the electrodes are apart from each other), the transition to the separated state is detected. Therefore, the switch mechanism 43 detects a transition to the separated state, although temporarily, when using the cushion member 28 that causes some vibration in accordance with a change in the posture of the user 30, for example. There is a possibility (that is, there is a possibility of false detection).

On the other hand, as described above, the switch mechanism 13 of FIG. 3B can be used even when the distance between the electrodes (17a, 17b) changes with the change in the posture of the user 30 (change in the degree of bending of the cushion member 28). , The transition to the separated state is not detected unless a large change occurs such that the electrodes (17a, 17b) come into contact with each other. Therefore, the switch mechanism 13 is less likely to cause erroneous detection even when the cushion member 28 that causes a certain amount of vibration according to the change in the posture of the user 30 is used.

The invention made by the present inventor has been specifically described above based on the embodiments, but the present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the invention. For example, the above-described embodiments have been described in detail in order to explain the present invention in an easy-to-understand manner, and are not necessarily limited to those having all the configurations described. Further, part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. .. Further, it is possible to add/delete/replace other configurations with respect to a part of the configurations of the respective embodiments.

10, 40 Contact sensor 11 Plate member 12 Support mechanism 13,43 Switch mechanism 14,44 Elastic member 15 Shaft rod 17,47 Electrode 18 Wiring 19 End 20 On area 21 Off area 22 Boundary 25 Wheelchair 26 Wheel 27 Seat surface 28 Cushion Member 29 Backrest 30 User 31a Normal sitting area 31b Dangerous sitting area 35 Contact sensor device 36 Cover member

Claims (8)

A contact sensor installed under a cushion member on which a user sits,
The contact sensor is
A first plate-shaped member,
A linear fulcrum mechanism installed on the first plate-shaped member and extending in a first direction within a plane of the first plate-shaped member;
The seesaw structure is installed on the fulcrum mechanism so as to face the first plate-shaped member with the fulcrum mechanism interposed therebetween, and the inclination with respect to the first plate-shaped member changes due to a seesaw structure having the fulcrum mechanism as a fulcrum. A second plate-shaped member,
In the second direction intersecting the first direction within the plane of the first plate-shaped member, both ends of the first plate-shaped member and the second plate-shaped member sandwich the fulcrum mechanism. A case where the first plate is installed at the first end of the first end and the second end, is in a contact state in an initial state, and the second plate-shaped member is inclined toward the second end side by the seesaw structure. A switch mechanism that is in a non-contact state with
Has,
Contact sensor. The contact sensor according to claim 1,
The switch mechanism has a first electrode and a second electrode installed on the first plate-shaped member and the second plate-shaped member, respectively.
Contact sensor. The contact sensor according to claim 1,
In the second direction, the distance between the second end and the fulcrum mechanism is ½ to 5 times the distance between the first end and the fulcrum mechanism.
Contact sensor. The contact sensor according to claim 1,
In the initial state, the second plate-shaped member is installed so as to incline toward the second end side at an angle “θ” with respect to the first plate-shaped member,
The angle “θ” is “0°≦θ≦10°”,
Contact sensor. The contact sensor according to claim 4,
Further, at a position between the fulcrum mechanism and the second end, at a position between the first plate-shaped member and the second plate-shaped member, a direction in which the switch mechanism is brought into the contact state. Equipped with an elastic member with reaction force "P",
The reaction force “P” and the angle “θ” satisfy “P≧(0.1−θ/100)”,
Contact sensor. The contact sensor according to any one of claims 1 to 5,
The contact sensor is installed below the outer peripheral portion of the cushion member such that the first end faces the outer peripheral side of the cushion member and the second end faces the inner side of the cushion member. Detecting that the user has left the cushion member based on a transition of the switch mechanism from the non-contact state to the contact state,
Contact sensor. The cushion member,
The contact sensor according to claim 1, which is installed under the cushion member,
A seat for seating. A seat surface on which the cushion member is mounted,
The contact sensor according to any one of claims 1 to 6, which is installed on the seat surface,
Wheelchair with.

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