JPH09187341A - Wrong operation preventing device for wired driving system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To arrest the sudden operation of a driving source by the failure of a signal line, and easily know the failure of the signal line. SOLUTION: A switch operating means 21 is connected to a control device 23 through a required number of common lines L11 -L13 and signal lines L14 -L16 , and the input and output interface 25 of a controller 22 having switching elements u-x independently connected to the common lines and signal lines is input an operation signal from the signal line to the operation switch, the common line and the input and output interface 25 by the input of operation switches S11 -S19 when the signal line is normally operated. When a certain signal line is short-circuited with the common line, a CPU 16 reversely carriers a short-circuit current from the common line to the signal line when the connecting point of the switching element connected to the short-circuited common line is in L-level when this element is ON, whereby the abnormality of the signal line is early detected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to, for example, automatically raising or lowering a seat of an electric chair, or inclining a back plate of a chair at a predetermined angle, and further, furniture such as a floor of a bed or a hanging cabinet. When driving a drive source that raises and lowers to an arbitrary height position by wire operation, a short circuit accident occurs in the signal line wired between the control device that drives and controls the drive source and the switch means that operates this control device. The present invention relates to an improvement in a malfunction prevention device for a wired drive system that immediately stops power supply to stop the drive source when an abnormality such as the above occurs.

[0002]

2. Description of the Related Art Conventionally, for example, a seat of an electric chair, a floor of a bed for a physically handicapped person, and even furniture such as a hanging cabinet can be driven at arbitrary heights by reciprocally driving a drive rod. Electric actuators are widely used as a drive source for moving up and down to a position. The electric actuator is generally a screw shaft that is decelerated by an electric motor through a reduction gear,
A drive rod is connected through a nut member, and the drive rod is configured to be linearly movable by converting the rotational movement of the screw shaft into a linear movement.

Next, the electric actuator is, for example,
An example implemented in an electric bed apparatus used by a bedridden medical person or a physically handicapped person will be described with reference to FIG. In FIG. 5, the bed apparatus 1 is divided into a back floor frame 2, a seat floor frame 3 and a lower floor frame 4 to form a frame body 5, and the back floor frame 2 and the seat floor frame 3 have a back floor and A mat body 6 also serving as a seat floor mat and a lower floor mat body 6a are laid on the lower floor frame 4, respectively, so that the back floor frame 2 and the lower floor frame 4 are individually provided above and below a predetermined distance. It is configured so that it can be raised and lowered at an angle.

The electric bed apparatus 1 has a comfortable bed life for both patients and caregivers.
Further, it is very effective in reducing labor for nursing, and in addition, it is convenient that the bed device can be easily raised and lowered and moved up and down by operating the operation switch with the patient's permission. And as a device for undulating the back floor frame 2 and the lower floor frame 4 of the bed apparatus 1,
Generally, a floor undulation mechanism is provided on the lower side of the bed apparatus 1, and in this example, as shown in FIG. 5, only the back floor undulation mechanism 7 for undulating the back floor frame 2 is shown. This back undulation mechanism 7
In general, an electric actuator 8 for converting the above-mentioned rotational movement into a linear movement is used. For example, as shown in FIG. The tip end side of the drive rod 9 which linearly moves by the rotation of the screw shaft is attached to the mounting body 3 a hung on the seat floor frame 3 to the operating arms 10 attached to the back floor frame 2.

Although not shown in FIG. 5, the electric actuator 8 drives the back floor frame 2, and the lower floor frame 4 is centered around a pivotal support (not shown) of the seat frame 3. When you want to undulate the angle,
At least three bed devices 1 are attached to the bed device 1 including the case where the bed device 1 is vertically moved up and down by a predetermined dimension. In the description of this conventional technique, the backfloor frame 2 is undulated as a typical example. A case where the back undulation mechanism 7 is implemented will be described.

Next, the case of operating the electric actuator 8 for driving the back undulating mechanism 7 will be described. As shown in FIGS. 5 and 6, a switch box 12 for accommodating a switch means 11 for displacing / moving the bed apparatus 1 is disposed at a position on the bed apparatus 1 that can be reached by a patient or a caregiver. On the side of the electric actuator 8 on the floor of the bed apparatus 1, a control device 14 containing a controller 13 for outputting a command signal for supplying drive power to the electric actuator 8 is attached. Further, the switch means 11 and the control device 14 are electrically connected by a plurality of signal lines L _{1 to} L ₇ , as shown in FIG. 7.

Next, the configuration of the switch means 11 and the controller 13 in the control device 14 will be schematically described. In general, electric furniture is basically operated only when the switch is turned on in consideration of safety.
Therefore, in FIG. 7, the switch means 11 is configured to include a required number of, for example, momentary type switches S _{1 to} S ₆ , and each of these switches S _{1 to} S ₆ is individually connected to the signal line L _1. Are connected by L ₆ . Further, L ₇ parallel to the signal lines L _{1 to} L ₆ is derived from the switch means 11 as a common line (ground line) connected in series with each of the switches S _{1 to} S ₆ .

On the other hand, the controller 13 on the control device 14 side
Is composed of an input / output interface (I / O) 15 for exchanging various signals with the switch means 11 via signal lines L _{1 to} L ₆ and a CPU 16 for performing arithmetic processing. A drive circuit 17 for controlling the supply / interruption of drive power to the electric actuator 8 based on a command signal from the CPU 16 is connected to the output end (output end of the controller 13). The control device 14 and the switch means 11 are connected to the signal lines L _{1 to} L via the CPU 16 and the input / output interface 15.
_And a common line L ₇ connected in series with the switches S _{1 to} S ₆ from the switch means 11.
Is led out and is grounded to a portion (not shown) in the control device 14.

[0009]

However, the control device 1 provided on the switch means 11 and the electric actuator 8 side.
4 is electrically connected by a wired system using the signal lines L _{1 to} L ₆ and the common line L ₇ as described above, so that
For example, when the back floor frame 2 of the bed apparatus 1 is raised from the state of FIG. 5 at a predetermined angle shown in FIG.
When the switch S ₁ of No. 1 is turned on, an operation signal is output to the input terminal of the input / output interface 15 via the signal line L ₁ to which the switch S ₁ is connected, and the voltage of the input terminal of the input / output interface 15 changes. (For example, the voltage of the input terminal of the input / output interface 15 to which the signal line L ₁ is connected is normally 5 V changes to 0 V. See FIG. 8A.) Based on this, the operation signal from the switch means 11 is sent. Is sent to the control device 14, and this control device 14
In, the command signal corresponding to the operation signal is output from the CPU 16 of the controller 13 to the drive circuit 17, and the drive power corresponding to the command signal is supplied to the electric actuator 8.
To wake up the back bed frame 2 of the bed apparatus 1.

Next, when the wake-up operation of the back floor frame 2 is stopped, that is, when the drive of the electric actuator 8 is stopped, the switch S ₁ is released from the closed state, and the switch is connected to the signal line L _1. Since the output of the operation signal from the means 11 is canceled, the input / output interface 1
The voltage of the input terminal 5 changes from 0V to 5V again, for example. As a result, the output of the command signal for the drive power supply from the controller 13 is stopped, so that the electric actuator 8 is de-energized to stop the drive and stop the wake-up operation of the back floor frame 2 (see FIG. 8A). ).

Then, in the above state, the signal lines L ₁ to
The L ₆ and the common line L ₇ are damaged for some reason, for example, they are sandwiched in the gap of the drive unit of the bed apparatus 1 or an external force is applied, and further, the insulation of the signal line is deteriorated. Then, for example, when the signal line L ₂ and the common line L ₇ are short-circuited, the short-circuit current flows in the clockwise direction in FIG.
The voltage of the input terminal of the input / output interface to which the signal line L ₂ is connected changes to 0 V as shown in FIG. 8B. This short-circuit phenomenon regardless turned-blocking artificial switch S _2, a state in which the switch S ₂ is substantially turned.

That is, even if the switch S ₂ is not artificially turned on, with the short-circuit phenomenon between the signal line L ₂ and the common line L ₇ , the state becomes substantially the same as when the switch S ₂ is turned on. , The voltage of the input terminal of the input / output interface 15 connected to the signal line L ₂ changes (for example, normally 5
What is V changes to 0V). As a result, the controller 13 determines that the switch S ₂ has been turned on, the command signal is output from the CPU 16 to the drive circuit 17, and the drive power is supplied to the electric actuator 8 which is the drive source to drive the electric actuator 8.

If the switch S ₂ is a switch for returning the back floor frame 2 from the wake-up state to the horizontal state shown in FIG. 5, the back floor frame 2 is operated by an operator (patient or the like).
Rotate in the direction of returning to the horizontal state contrary to the will. Therefore, for example, the betting apparatus 1 leans against the back floor frame 2 and
The patient sitting on the floor may be surprised by the unexpected drive of the back floor frame 2 and may accidentally sandwich a part of the limbs, clothes or the like with the link portion of the bed apparatus 1.

In particular, when the patient is lying on the bed apparatus 1 and the back frame suddenly wakes up or the bed apparatus 1 abruptly ascends and descends, not only the patient on the bed but also the caregiver is surprised. Not only that, there is a risk that the drive unit of the bed apparatus 1 may be caught and damage to a part of the body, luggage, or the like. Further, the signal line L ₁ ~L ₆ because it is connected to the switch individually effort was consuming only one very uneconomical to many present and become the connecting work.

In view of the above problems, the present invention connects each switch of the switch means and a controller for driving and controlling a drive source such as an electric actuator by a plurality of wired signal lines to connect the signal line and the common line. If a wire is stepped on or caught in a gap between devices, and the signal wire connecting the switches and the common wire come into contact with each other to cause a short circuit, a command signal from the control device It is an object of the present invention to provide a malfunction prevention device for a wired drive system, which reliably prevents the drive source from unexpectedly operating.

[0016]

SUMMARY OF THE INVENTION The present invention comprises a switch operating means having a plurality of operation switches, each switch comprising a plurality of operation switches as a set, and a predetermined number of operation switches. One end is connected to the anode of a diode for blocking current backflow provided by the same number as the total number of sets of these operation switches through a lead wire, and the cathode side is connected to the controller in the control device through a common line (common). Connecting. On the other hand, the other end of the operation switch of each set is connected in parallel by using a lead wire for each set, and a signal line is connected to a common connection point of the connection lines connected in parallel and connected to a controller. By doing so, the switch operating means and the controller of the control device are electrically connected.

Further, the controller in the control device has an input / output interface having a built-in switching element for exchanging various signals with each operation switch of the switch operation means, and connected to the input / output interface. C, which monitors the input voltage and outputs a command signal for driving power supply / interruption control to the drive source depending on whether the input voltage is maintained at the set voltage or not.
It is configured to include a PU (Central Processing Unit) and a drive circuit for supplying / disconnecting drive power to / from a drive source based on a command signal from the CPU.

[0018]

According to the present invention, in a plurality of signal lines wired between the switch operating means and the controller of the control device,
Between a certain signal line and a common line that connects each set of operation switches to a switching element in the input / output interface via a diode for blocking the backflow, for example, the signal line and the common line are crushed or conductive. When a short circuit accident occurs due to the invasion of the volatile liquid, the voltage at the input end of the input / output interface to which the short-circuited common line is connected becomes 0V, and the signal line short-circuited with this common line is detected. The input terminal of the input / output interface also becomes 0 V, and the short-circuit current flows to the ground side via the switching element connected to the signal line. At this time, the CPU constantly monitors the voltage at the input end to which each common line and signal line of the input / output interface is connected, and detects that the voltage at the input end drops due to the short circuit of the common line as described above. , It is determined that a short circuit has occurred in the signal line.

As a result, the controller does not operate in response to a command from the CPU, which causes the drive source to operate abruptly, so that the furniture such as the bed device or the hanging cabinet does not operate the operation switch. Therefore, it is possible to surely avoid the adverse effect that it operates.

The present invention also includes a plurality of operation switches.
As a set, one end of each of the operation switches of each set is connected to a diode for backflow prevention through a lead wire, and the diode is connected to a switching element of an input / output interface through a common line. On the input / output interface side of the switch, the signal line is connected to the common connection point of each connection line that individually connects a plurality of operation switches, and is connected to the switching element of the input / output interface. It is possible to connect the switch operating means and the controller with a small number of the signal lines, and the signal line connection work can be performed easily and economically. Further, since the number of signal lines can be set to half or less of the number of operation switches, the connection between the switch operating means and the control device can be simplified.

Further, according to the present invention, when a required operation switch of the switch operation means is operated, an operation signal (current) flowing in a normal state is input from the input / output interface to a signal line → operation switch → lead wire → diode → common line → input. Although it flows to the output interface, when the common line and the signal line are short-circuited, the short-circuit current flows in the order of input / output interface → common line → signal line → input / output interface, contrary to the normal state. That is, since a reverse current blocking diode does not pass and the current flows in the opposite direction to the normal state, a short circuit accident occurs between the switch operating means and the control device easily and reliably by detecting this current. You can figure out that. As described above, since the current (operation signal) flowing in the normal state and the short-circuit current flowing in the short circuit are made to flow bidirectionally between the input / output interface and the switch operating means, the direction in which the current flows is detected. Thus, the short-circuit current can be easily detected, which is convenient.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. It should be noted that the present invention will be described, for example, as an example in which the drive source of the bed apparatus for a physically handicapped person is implemented in a control device that controls the drive by wire as necessary. And, regarding the electric actuator that is the drive source and the bed device that is driven by the electric actuator,
This will be described with reference to FIGS.

In FIG. 1, reference numeral 21 is a switch operating means for driving and operating the electric actuator 8 as a driving source, and 22 is a controller for driving and controlling the electric actuator 8 as a driving source in response to an operation signal from the switch operating means 21. . As shown in FIGS. 5 and 6, the switch operating means 21 is a switch box 12 installed near the bed apparatus 1 at a place where a patient or a caregiver can easily operate.
It is housed so that it can be taken out freely. Also, the controller 22
Similarly, the electric actuator 8 is housed and held in the control device 23 installed on the trailing edge side of the base end portion of the electric actuator 8 shown in FIGS.

Next, the structure of the switch operating means 21 will be described. The switch operating means 21 is, for example, as shown in FIG. 1, a back floor frame 2 of a bed apparatus 1 (see FIG. 5).
And operation switches S _{11 to} S for tilting or raising / lowering the lower floor frame 4 or the bed apparatus 1 itself.
It is configured by arranging the required number of ₁₉ (nine in this example) in a vertically connectable state.

As shown in FIG. 1, the operation switches S _{11 to} S _{19 form a} set of three switches to form first, second, and third switch groups a, b, c, and each switch. One of the groups a to c has a pair of lead wires d, e,
In a state of being individually connected to f, they are connected to the anode side of the backflow preventing diodes D _{1 to} D ₃ . That is, the operation switches S ₁₁ , S ₁₄ , and S ₁₇ of each switch group a, b, and c are connected to the lead wire d, the operation switches S ₁₂ , S ₁₅ , and S ₁₈ are connected to the lead wire e, and the operation switches S ₁₃ and S _{16 are connected.} , S ₁₉ are connected to the lead wire f, respectively. On the other hand, the diodes D ₁ to
The cathode side of D ₃ is connected to the input / output interface (I / I) in the controller 22 via the common lines L _{11 to} L _13.
0) First to third switching elements provided on the input terminal side of 25 (in this example, a grounded-emitter transistor is used)
It is connected to u, v, and w.

As a result, the first switch group a is connected to the first switching element u of the input / output interface 25 through the lead wire d → diode D ₁ → common line L ₁₁ .
Hereinafter, the second switch group b includes the lead wire e → the diode D.
₂ → common line L ₁₂ → switching element v, and third switching group c is lead wire f → diode D ₃ → common line L
₁₃ → Connected to switching elements w, respectively.
The connection points P _{1 to} P ₃ between the _first to third switching elements u to w and the common lines L _{11 to} L ₁₃ are connected to the required constant voltage power supply Vcc (5V) of the power supply device (not shown). Has been done.

[0027] Subsequently, other operation switches S ₁₁ to S _19, i.e., the switch groups a, b, the other c, as shown in Figure 1, for example, three constituting the first switch group a Connection line g derived from each of the operation switches S _{11 to} S _13
1 is connected in parallel, and the signal line L ₁₄ is connected to this connection point.
Hereinafter, the second in the same manner, the third switch group b, the operation switch _{S 14 ~S 16, S 17 ~S} 19 constituting the c are parallel connected respectively with connecting lines g _2, g _3, these Connection line g
_The signal lines L ₁₅ and L ₁₆ are connected to the respective connection points of ₂ and g ₃ . The signal lines L _{14 to} L ₁₆ are individually connected to the switching element x of the input / output interface 25. That is, as shown in FIG. 3, the signal lines L _{14 to} L ₁₆ are connected in parallel to the switching element x via the diodes. As described above, the switch operating means 21 and the controller 22 of the control device 23 are electrically connected to each other by a wire system using the three common lines L _{11 to} L ₁₃ and the signal lines L _{14 to} L ₁₆ in this embodiment. Has been done.

On the other hand, the controller 22 in the controller 23
As shown in FIG. 1, the built-in switching elements u, v, w and x for exchanging required signals with the switch operating means 21 via a common line and signal lines L _{11 to} L ₁₆ . The input / output interface 25 and the common line L based on the input information of the input / output interface 25.
_{11 to} L ₁₃ , signal lines L _{14 to} L ₁₆ and switching elements u to x
(Refer to FIGS. 2 and 3, but the connection points of the common lines L ₁₂ and L ₁₃ are omitted in FIG. 2) The input voltages of P _{1 to} P ₆ are detected (in this case, the switching elements u to x are The CPU 16 outputs the command signal for energizing / stopping the electric actuator 8 by performing arithmetic processing based on this input voltage and sequentially turning on and detecting at a constant cycle). The output terminal of the controller 22 has the CPU
A drive circuit 17 for controlling supply / interruption of drive power based on a command signal from 16 is connected to the drive circuit 17, and the output end thereof is connected to the electric actuator 8 serving as a drive source.

Although not described in this embodiment, the drive circuit 17 for controlling the drive of each of the electric actuators for the electric actuators for driving the lower floor frame 4 and the electric actuators for vertically moving the bed apparatus 1.
However, it goes without saying that the output terminal of the controller 22 is electrically connected to the CPU 16.
Further, in FIG. 2, in the input / output interface 25, the common line L ₁₁ (L ₁₂ and L ₁₃ are omitted) and the switching element u
The details of the connection state with (v and w are omitted) are shown.

Further, in FIG. 3, the signal lines L _{14 to} L _{16 are}
3 shows the details of the connection relation between the switching element x and the switching element x. In the case of FIG. 3, one switching element x is used in comparison with FIG. 1, but in FIG.
Although three switching elements x are shown in the drawing for the purpose of explaining the relationship between the controller 22 and the controller 22, the switching element x shown in FIG.
It goes without saying that it is the same as the switching element x shown by. In FIG. 3, the signal line L ₁₄ ~L ₁₆ and the switching elements each connecting point P ₄ to P and x ₆ are connected through a diode and a resistor to the constant voltage source Vcc of a power supply device (not shown) (5V) ing.

Next, the operation of the present invention will be described. The present invention describes, for example, an example implemented in a drive device of a bed apparatus 1 for a physically handicapped person. Now, for example, as shown in FIG. 5, when the back floor frame 2 is in a horizontal state, the bed apparatus is provided. When a user (patient) of 1 sits on the bed apparatus 1 with the back bed frame 2 standing up on the bed at a predetermined angle, that is, as shown in FIG. When raising at a predetermined angle, for example, the operation switch S ₁₁ is turned on.

When the operation switch S ₁₁ is turned on, the constant voltage power supply Vcc is taken out (flows) as an operation signal to the signal line L ₁₄ to which the switch S ₁₁ is connected, as shown in FIG. That is, the input / output interface 25
Input terminal connected to the signal line L ₁₄ (the connection point P ₄ where L _{14 in} FIG. 3 is connected to the constant voltage power supply Vcc)
The CPU 16 confirms that the voltage detected at is 0V (“L” level) by turning on the operation switch S ₁₁ . In this case, the input terminal of the input / output interface 25 connected to the signal lines L ₁₅ and L ₁₆ (connection point P
_Since the corresponding operation switches S _{14 to} S ₁₉ are not turned on, ₅ and P ₆ ) are at the “H” level even if the signal lines S _{14 to} S ₁₆ are connected to the common switching element x. .

In this way, when the operation switch S ₁₁ is turned on, the CPU 16 causes the common line L _{11 of the} input / output interface.
The voltage at the connection points P ₁ and P ₄ of the input terminals connected to the signal line L ₁₄ is detected by closing the switching elements u and x, and the connection point P ₁ is at the “H” level (5 V) and the connection point P. _When it is confirmed that ₄ is at the “L” level (0 V), the constant voltage power supply Vcc is connected to the connection point P _{4 of the} input / output interface 25.
From the signal line L _{14 to the} connection line g _{1 to the} operation switch S _{11 to the} lead wire d to the backflow prevention diode D _{1 to the} common line L ₁₁ to the input / output interface 25 in the clockwise direction, and the switching element u is released. Since it flows to the outside of the input / output interface 25 when it goes to "L" level by the command of the CPU 16, the CPU 16 can confirm that the signal line L ₁₄ is in a normal state and only the operation switch S ₁₁ is turned on.

At this time, when any one of the operation switches S _{14 to} S ₁₆ or S _{17 to} S ₁₉ is turned on, the connection points P ₂ and P ₃ of the input / output interface 25 are at “L” level,
The CPU 1 confirms that the connection points P ₅ and P ₆ are also at the “L” level.
6 detects the signal line L ₁₅ ,
It goes without saying to confirm that L ₁₆ is normal. In this way, when the CPU 16 of the controller 22 determines that the signal line connecting the operated operation switch is normal, the CPU 16 of the controller 22 outputs a command signal corresponding to the operation signal sent through the signal line L _14. Is output to the drive circuit 17, drive power corresponding to the command signal is supplied to the electric actuator 8,
The back floor frame 2 of the bed apparatus 1 is woken up.

Next, when the driving of the electric actuator 8 is stopped at the inclined position shown in FIG. 6, for example, the operation switch S ₁₁ may be released. When the operation switch S ₁₁ is opened, the input / output interface 25 of the signal line L ₁₄
At the connection point P ₄ of the input terminal of P and the connection point P ₁ of the common line L ₁₁ , the constant voltage power supply Vc is generated when the operation switch S ₁₁ is opened.
This is because c does not flow to the signal line L ₁₄ and the common line L ₁₁ . Therefore, the CPU 16 causes the voltage detected at the connection points P ₁ and P ₄ of the input terminals of the input / output interface 25 to be “H” even when the switching elements u and x are ON.
Since it can be confirmed that it is at the level (5V), the switch S ₁₁ is opened in the normal state of the signal line L ₁₄ .

Therefore, the output of the command signal from the CPU 16 of the controller 22 is stopped, and the electric actuator 8
De-energizes and stops its drive. As a result, as shown in FIG. 6, the backfloor frame 2 stops its wake-up operation when the operation switch S ₁₁ is released. Note that the normal signal line, the common line and the signal line L ₁₄ ~L ₁₆ L ₁₁ ~L ₁₃
And indicate that they are not conductive (short-circuited).

Subsequently, in the above state, of the signal lines L _{14 to} L ₁₆ connecting the switch operating means 21 and the controller 22 of the control device 23 in a wired manner, for example, the signal line L ₁₄ and a common line. A case will be described in which L ₁₁ or L ₁₂ , L ₁₃ is damaged by an external force or the like, which causes the signal line L ₁₄ and, for example, the common line L ₁₁ to be conductive (short-circuited). As described above, when the signal line L ₁₄ and the common line L ₁₁ are short-circuited, the switching element x of the input / output interface 25 is instructed by the CPU 16 of the controller 22.
When the signal is turned on (turned on), the signal line L ₁₄ and the common line L ₁₁ are electrically connected, and therefore the CPU 16 detects that the connection point P ₁ of the common line L ₁₁ is at the “L” level (0 V). To do.

As a result, when the switching element x of the input / output interface 25 is turned on by a command from the CPU 16, the constant voltage power supply Vcc of the CPU 16 prevents reverse current from the connection point P ₁ of the input / output interface 25 by the diode D _1. Then, the common line L ₁₁ → the signal line L ₁₄ which is short-circuited → the route of the switching element x built in the input / output interface 25, that is, it is recognized that it flows out of the input / output interface 25 in the counterclockwise direction. Confirm that the signal line L ₁₄ is “short-circuited”.
In this way, the CPU 16 issues an ON / OFF command to the switching element x at regular intervals, and when it is ON, the common line L
_When the voltage at the connection point P ₁ of the input terminal of the input / output interface 25 to which ₁₁ is connected is detected and the detected voltage is at the “L” level (0 V), the signal line L ₁₄ and the common line L ₁₁ are short-circuited. Can be confirmed.

In the above state, the CPU of the controller 22
16 can not detect the voltage of the "H" level (5V) at the connection point P ₁ to P ₃ of the common line L ₁₁ ~L _13,
At this point, it will be judged as "abnormal". Also in this case, similarly to the above, the CPU 16 of the controller 22 repeats the above-described abnormality determination, for example, eight times to enhance the certainty of the detection accuracy.

Therefore, the CPU 16 of the controller 22
Determines that the signal (data) generated on the signal line L ₁₄ is abnormal, and does not output the corresponding command signal to the drive circuit 17 when the signal is normal, for example, when the operation switch S ₁₂ is turned on. Therefore, regardless of whether the drive source is turned on or off, the drive source maintains the OFF state and the electric actuator 8 as the drive source suddenly drives due to the short-circuit phenomenon of the signal line L _14. Avoid and ensure safety. As a result, the back floor frame 2 of the bed apparatus 1 shown in FIG. 6 abruptly moves in the sunk direction or the rising direction due to the short circuit of the signal line L ₁₄ , and the patient on the bed apparatus 1 is marveled. Bed device 1 for patients
It is possible to surely eliminate problems such as giving discomfort and distrust of.

The mechanism at the time of abnormality in which the drive source does not operate when the signal line L ₁₄ is short-circuited will be described again with reference to the flow chart shown in FIG. As described above, the signal line L
_{When 14} is short-circuited with the common line L ₁₁ , the signal lines L _{14 to} L ₁₆ are shorted.
Since the connection points P _{4 to} P ₆ of the input terminals of the input / output interface 25 are all connected to the constant voltage power supply Vcc as shown in FIG. 3, step S10 of FIG.
1, the connection points P _{4 to} P of the signal lines L _{14 to} L _16
6 becomes "L" level. On the other hand, in the common line L ₁₁ ~L ₁₃ performs data capture in step S102, the connection point P ₁ of the common line L ₁₁ that is shorted to the signal line L ₁₄ Although the "L" level, the common Lines L ₁₂ , L ₁₃
Since the signal line L ₁₄ and the signal lines L ₁₅ and L ₁₆ are not short-circuited, the connection points P ₂ and P ₃ are at the “H” level.

The data fetched in step S102 is collated with the data fetched in step S102 a plurality of times, for example, eight times in order to prevent malfunction, and as a result of the collation in step S103, all of the eight times. If the results are the same, the data is sent to the next step S104. If the data do not match as a result of checking eight times, return to the start point and check again. The data sent from step S103 to step S104 is temporarily stored until the next data is output from step S102 as the current state of the switch operating means 21. Then, it is determined in step S105 whether or not the data sent from step S104 is abnormal data. If it is determined that the data is abnormal data, the common line L ₁₁ and the signal line L ₁₄ are short-circuited and “abnormal”. Then, the electric power supply to the electric actuator 8 is cut off.

On the other hand, if it is different from the data at the time of abnormality, it is judged to be normal in step S105, and the electric power can be supplied to the electric actuator 8 forever. In this case, the short-circuited state between the common line L ₁₁ and the signal line L ₁₄ is eliminated for some reason. However, as described above, since the stored data matches the stored data in step S105, if the CPU 16 determines "necessary", the CPU 16 causes the electric actuator 8 which is the drive source.
Since electric power is not supplied to the patient, it is possible to satisfactorily avoid the problem that the electric actuator 8 suddenly drives and surprises the patient who is resting on the bed 1, the attendant caregiver, or the like and is anxious. .

The signal lines L _{14 to} L ₁₆ and the common lines L _{11 to} L
_{When the} wire ₁₃ is disconnected, the electric actuator 8 does not operate because the input terminals of the input / output interface 25 are fixed at "H" level even if the switch operating means 21 is turned on. Also, between the signal lines L _{14 to} L ₁₆ or the common line L ₁₁
If a short circuit between the ~L _13, input-output interface 25
Since the connection points P _{1 to} P ₃ of the respective input terminals are fixed to the “L” level, the electric actuator 8 does not operate.

Although the present invention has been described with reference to the embodiment in which the electric actuator 8 as the drive source is operated, which is used when the back floor frame 2 of the bed apparatus 1 is raised and lowered, the present invention is not limited to this. 4 can be applied to the electric actuator 8 used for the up-and-down movement of the bed apparatus 4 and the raising / lowering operation of the bed apparatus 1, and can also be applied to an erroneous operation preventing unit of a wire-type drive apparatus for electrically driving each furniture such as an electric chair and an electric hanging cabinet. Needless to say.

[0046]

As described above, according to the present invention, a switch operating means having a plurality of operation switches and a control device having a controller for outputting a drive signal to a drive source have a plurality of signal lines and a backflow prevention. The input / output interface of the controller, which is connected by a plurality of common lines equipped with a diode for use, and which is connected by the plurality of common lines and signal lines, receives an operation signal when the operation switch is turned on: signal line → operation switch → diode → When the signals are input to the controller in the order of the common line and the common line and the signal line are short-circuited,
The short circuit current is provided in the opposite direction from the common line which is short-circuited in the opposite direction, so that the current is not applied to the controller through the signal line. Since it is configured so as to allow the current to flow, the situation of the signal line can be easily grasped by monitoring the direction in which the current flows, which is convenient.

Moreover, when any abnormality (short circuit) occurs in the signal line, the controller does not output the command signal for driving the signal to the drive source regardless of whether the switch operating means is turned on or off. Since the drive source does not drive at all even if an abnormal situation such as a short-circuit accident occurs in the signal line, even if the drive source is, for example, the drive source of a bed apparatus for caring for a physically handicapped person, Since it does not operate, it is possible to surely solve the problem that a part of the bed suddenly operates and gives the patient and the caregiver anxiety and discomfort.

Further, since one signal line for connecting the switch operating means and the control device is provided for each group having a plurality of operation switches, that is, one signal line is provided for each operation switch. Since it is not necessary to provide one by one, connection work between the switch operating means and the control device can be performed easily and economically. Furthermore, by reducing the number of signal lines, it is possible to suppress a short circuit accident with the common line, and thus it is possible to rationally solve the problem caused by the presence of the signal lines.

[Brief description of the drawings]

FIG. 1 is a circuit diagram schematically showing a malfunction prevention device for a wired drive system according to the present invention.

FIG. 2 is a circuit diagram showing details of a connection relationship between a common line and a switching element.

FIG. 3 is likewise a circuit diagram showing details of the connection relationship between the signal line and the switching element.

FIG. 4 is a flowchart illustrating a schematic operation of the malfunction prevention device.

FIG. 5 shows an example in which the device of the present invention is applied to a bed device for nursing care, for example, and is an explanatory diagram when the back floor frame of the bed device is in a horizontal state.

FIG. 6 is likewise an explanatory view showing a state in which the back frame of the bed apparatus stands up at a predetermined angle.

FIG. 7 is an electric circuit diagram schematically showing a conventional wired drive system.

FIG. 8 is a time chart diagram showing an operation state of a conventional wired drive system, in which (a) is a normal state and (b) is an abnormal state.

[Explanation of symbols]

1 Bed Device 2 Back Floor Frame 8 Electric Actuator 9 Drive Rod 10 Actuating Arm 11,21 Switch Means 13,22 Controller 14,23 Control Device 15,25 Input / Output Interface 16 CPU L ₁₁ 〜L ₁₃ Common Line L ₁₄ 〜L ₁₆ Signal line

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toru Yasuda 1 Aichi-cho, Aichi-cho, Kasugai-shi, Aichi Prefectural company (72) Inventor Takayoshi Adachi 1-ichi, Aichi-cho, Kasugai-shi, Aichi Aichi-denki Co., Ltd. ( 72) Inventor Towawa Aichi Electric Power Co., Ltd. 1 Aichi-cho, Kasugai-shi, Aichi

Claims (2)

[Claims] 1. A switch operating means comprising a plurality of operating switches for arbitrarily driving and operating an electrically driven drive device,
A control device having a controller for outputting a command signal for supplying electric power to the drive device is provided by a plurality of signal lines and a common line connected to the signal lines via a switch operating means and a diode for preventing backflow. The input / output interface is provided with a predetermined number of switching elements that are electrically connected and that are connected to the common line and the signal line. The input / output interface further includes an operation switch when the signal line is normal. The operation signal is input to the controller in the order of the signal line, the operation switch, the diode, and the common line, and when the signal line and the common line are short-circuited, the operation is short-circuited in the reverse order regardless of whether or not the operation switch is turned on. Current,
A malfunction prevention device for a wired drive system, comprising means for preventing input to a controller via a common line, a signal line, and a switching element connected to the signal line. 2. The switch operating means comprises a plurality of operating switches as one set, and the operating switches of each set are individually connected in parallel by connecting lines, and the operating of each of the parallel connected sets is performed. 2. The malfunction prevention device for a wired drive system according to claim 1, wherein the switch is connected to the control device by one signal line for each set.