JP7012782B2 - Automatic seat opening / closing device for vehicle luggage boxes - Google Patents

Description

INDUSTRIAL APPLICABILITY The present invention relates to an automatic seat opening / closing device in a vehicle luggage box, particularly a luggage box mounted on a vehicle body frame and having an opening on the upper surface, and having a predetermined opening position and closing position with respect to the opening. A seat that can be opened and closed between the seats, an electric motor that opens and closes the seat, an energization cutoff means that can cut off the energization of the motor from the battery, and a control device that can control the operation of the energization cutoff means. Regarding an automatic seat opening / closing device equipped with.

The automatic seat opening / closing device is conventionally known, for example, as shown in Patent Document 1.

Japanese Unexamined Patent Publication No. 7-108870

By the way, in the automatic seat opening / closing device, when the load current of the motor rises to a predetermined stop current value (that is, the cutoff current value), the control device is configured to immediately output a power stop command signal to the power cutoff means. Therefore, it is possible to prevent the occurrence of failure such as seizure of the motor and the energizing circuit portion due to the continuous increase of the load current of the motor.

However, in the conventional structure, by setting the stop current value (breaking current value) at the time of starting the motor to be sufficiently higher than the normal inrush current that is instantaneously generated at the time of starting the motor, energization (hence, sheet rotation) is performed due to the inrush current. We are trying to avoid the inconvenience that the dynamic operation) is stopped. For this reason, energization is not stopped until the load current of the motor rises to a higher stop current value, so the load current becomes excessive even temporarily depending on the startup status, and the motor and energization circuit section seize. And may cause a decrease in durability. A technique for switching and setting the stop current value according to the situation has also been proposed, but in that case, there is a problem that the control configuration is complicated by the switching setting of the stop current value.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide an automatic seat opening / closing device for a vehicle cargo box, which can solve the above problems with a simple structure.

In order to achieve the above object, the present invention is mounted on a vehicle body frame and pivotally supported by a packing box having an opening on the upper surface, between a predetermined opening position and a closing position with respect to the opening. It includes a seat that can be opened and closed, an electric motor that drives the seat to open and close, a current cutoff means that can cut off the current from the battery to this motor, and a control device that can control the operation of the current cutoff means. In the automatic seat opening / closing device for a vehicle cargo box, the control device outputs a command signal to stop energization of the motor to the energization cutoff means when the load current of the motor exceeds a predetermined stop current value. The stopping means is provided with a stopping means for controlling the motor, and the stopping means starts the control after a lapse of a set time from the start of energization of the motor, and when the load current of the motor exceeds a predetermined stop current value. The first feature is to measure the duration of the exceeded state and output a command signal to stop the energization to the energization cutoff means when the continuation time becomes a predetermined time or longer .

According to the first feature of the present invention, the control device of the automatic seat opening / closing device sends a command signal to the energization cutoff means to stop energization of the motor when the load current of the motor exceeds a predetermined stop current value. A stop means for controlling output is provided, and the stop means starts the control after a set time has elapsed from the start of energization of the motor. Therefore, even if the stop current value is suppressed to a low level, the load current of the motor increases. Can be reliably suppressed near the stop current value. This effectively prevents seizure of the motor and energization circuit due to excessive current, and it is not necessary to set the stop current value sufficiently higher than the inrush current, so the load current increases excessively. It is possible to reduce the frequency of this and improve the durability of the motor and the like .

Further, the stop means measures the duration of the exceeded state when the load current of the motor exceeds the predetermined stop current value, and energizes the motor according to the duration being longer than the predetermined time. Since a command signal to stop energization is output to the shutoff means, if the above control is set to start execution after the required time has elapsed from the start of energization to the motor to the end of the inrush current, when the motor is started. Even if the inrush current exceeds the stop current value for a predetermined time or longer, the energization of the motor can be prevented from stopping.

A side view showing an embodiment of a dump truck to which the present invention is applied. Rear view of the above dump truck (2 arrow view of FIG. 1) Front view showing an example of a controller for a seat switchgear An electric circuit diagram showing an example of a control circuit that controls the drive of one of the left and right motors (seat open / close control). It is a graph showing the time course of the motor load current during motor rotation. The solid line shows the motor forward rotation (when the seat is open), and the chain line shows the motor reverse rotation (when the seat is closed). It is a graph which shows the time-dependent change when the motor load current suddenly increases at the time of motor rotation, (A) shows the time-dependent change of the output of the addition circuit 27 in the said control circuit, (B) is the time change of the addition circuit 27. The output and the output of the waveform signal generation circuit 29 are compared and shown with time, (C) shows the time change of the output of the comparison circuit 28, and (D) shows the time change of the motor load current.

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

In FIGS. 1 and 2, a packing box 2 having an opening O on the upper surface is pivotally supported on the vehicle body frame 1 of the dump truck V as a vehicle, and the packing box 2 and the vehicle body frame 1 are pivotally supported. A well-known drive mechanism (not shown) that forcibly tilts the packing box 2 backward is interposed. Further, on each of the upper edges of the left and right plates 3 and 3 of the packing box 2, at least a part of the opening O of the packing box 2 (in the embodiment, the left and right outer portions of the opening O) can be opened and closed. Sheet S is attached to each.

The sheet S is composed of a sheet material 4 such as cloth and a square frame-shaped sheet frame 5 that retains the sheet material 4 in a predetermined rectangular shape, and the base end of the sheet frame 5 extending in the front-rear direction. The shaft portion 5a is rotatably supported by a plurality of bearing portions 6 provided at intervals on the upper edges of the left and right plates 3 and 3.

The output shafts of the pair of left and right electric motors M attached to the front end portion of the packing box 2 are interlocked and connected to the base end shaft portion 5a via the reduction mechanism 7. Therefore, when at least one of the left and right motors M is rotationally driven in one direction, the seat S on the same side is hung from the bearing portion 6 and extends from the opening position So extending along the outer surface of the side plate 3 from the bearing portion 6. Forcibly closed and swung to the closed position Sc extending horizontally inward from the bearing portion 6 through the intermediate horizontal position Sh extending horizontally outward and the intermediate standing position Sv standing vertically from the bearing portion 6. Further, when at least one of the left and right motors M is rotationally driven in the other direction, the seat S on the same side can be forcibly opened and swung by the reverse path described above.

The left and right motors M are composed of forward and reverse DC motors having first and second power receiving units Ma and Mb which are input terminals at the time of forward rotation and reverse rotation, respectively. FIG. 4 shows an example of a control circuit C that drives and controls the left and right motors M to control the opening and closing of the left and right seats S, and the circuit description will be described later. As the control circuit C, two sets having the same circuit configuration are provided corresponding to the left and right seats S in order to independently control the opening and closing of the left and right seats S.

Further, the driver's seat of the dump truck V, for example, the instrument panel, is provided with a controller 8 for the operator to arbitrarily open and close the seat S (see FIG. 3). The operation unit of the controller 8 includes a forward / reverse selection switch SWm that can select forward / reverse of each motor M and also serves as a power switch, and a left drive switch SWa and a right drive switch SWa that rotate and drive the left and right motors M individually. Each operation knob of the drive switch SWb is arranged.

The forward / reverse selection switch SWm is composed of a toggle switch that can be switched and held at three positions. Further, the left and right drive switches SWa and SWb are composed of momentary switches that are turned on when the operation knob is pressed once, and then remain on even when the operation knob is released and the operation knob returns to the original position. The on state is turned off by switching the forward / reverse selection switch SWm to the neutral position.

Therefore, when the operation knob of the forward / reverse selection switch SWm is in the neutral position, the power of the controller 8 is turned off and the motor M is held in the stopped state. Further, when the operation knob is in the forward rotation selection position on one side or the reverse rotation selection position on the other side of the neutral position, the power of the controller 8 is turned on and the forward rotation or reverse rotation of the motor M can be selected. Therefore, for example, when the operation knob of the left drive switch SWa is pressed while the forward / reverse selection switch SWm is held at the forward rotation selection position, the control circuit C for the left seat S corrects the left motor M. When the left seat S is rotated to open and the operation knob of the right drive switch SWb is pressed, the control circuit C for the right seat S drives the right motor M in the forward direction to drive the right motor M to the right. The sheet S opens.

Further, when the operation knob of the left drive switch SWa is pressed while the forward / reverse selection switch SWm is held at the reverse selection position, the control circuit C for the left seat S reversely drives the left motor M. When the left seat S is closed and the operation knob of the right drive switch SWb is pressed, the control circuit C for the right seat S reversely drives the right motor M to close the right seat S. Operate.

Next, an example of the control circuit C will be described with reference to FIG. 4. As described above, the control circuit C has the same circuit configuration corresponding to each of the left and right motors M in order to independently control the opening and closing of the left and right seats S. For example, two sets are provided between the vehicle body frames 1).

Next, the circuit configuration of the set will be described below. In the following description, it is not particularly stated whether the motor M or the seat S is left or right.

The control circuit C individually provides the first and second connection paths 11 and 12 interposed in parallel between the battery 10 and the ground 9 and the first connection path 11 provided in series with each other in the first connection path 11. The normally open type first opening / closing means 13 and the first reversing opening / closing means 15 that open / close to each other, and the normally open type that is provided in series with the second connecting path 12 and opens / closes the second connecting path 12 individually. The second forward / reverse opening / closing means 14 and the second reverse rotation opening / closing means 16 are provided, and an electronic control unit U as a control device capable of opening / closing the opening / closing means 13 to 16 thereof is provided.

In addition to the CPU, the electronic control unit U includes a memory associated with the CPU, a hard disk, a timer means T (not shown in FIG. 4 except for the CPU and the timer means T), and a limiting circuit 40 described later. In this embodiment, the controller 8 is built in and is operated by the power from the battery 10.

A first energizing path 21 is provided between the first forward switching opening / closing means 13 and the first reverse rotation opening / closing means 15 of the first connecting path 11, and the second forward turning opening / closing means 14 and the second of the second connecting path 12. The second energizing path 22 is branched from between the reversing opening / closing means 16. The first energization path 21 is connected to the first power receiving unit Ma of the motor M (that is, the terminal on the input side when the motor is reversed), and the second energizing path 22 is the second power receiving unit Mb of the motor M (that is, the motor is positive). It is connected to each terminal on the input side at the time of turning.

Further, in the first current-carrying path 21 and the second current-carrying path 22, the first, which detects the current flowing through the motor M, therefore, the first and second current-carrying paths 21 and 22 (that is, the load current of the motor) when the motor M rotates. The first and second ammeters SE1 and SE2 are provided as the second detection sensor, respectively.

In the present embodiment, as the first and second ammeters SE1 and SE2, from the viewpoint of safety, voltmeters that convert the current flowing through the first and second current paths 21 and 22 into a voltage and detect them are used, respectively. However, even in that case, the increase / decrease change of the current flowing through each of the energization paths 21 and 22 linearly corresponds to the increase / decrease change of the measured value (detection voltage) of the voltmeter. If necessary, it is also possible to directly detect the current flowing through the first and second energization paths 21 and 22 with an ammeter.

The first and second forward rotation opening / closing means 13 and 14 and the first and second reverse rotation opening / closing means 15 and 16 cooperate with each other to form the energization cutoff means X of the present invention, and are electronic control units. The opening / closing control is individually performed based on the energization command signals output from U via the first and second forward conversion signal paths 23 and 24 and the first and second reverse rotation signal paths 25 and 26, respectively. Therefore, each of the opening / closing means 13 to 16 is normally held in an open state to cut off the corresponding connection paths 11 and 12, and an energization command signal (output voltage) is applied to each of the opening / closing means 13 to 16. When it is done, it switches to the closed state and conducts the corresponding connection paths 11 and 12 so that the motor M can be energized.

Further, in the present embodiment, the second forward conversion signal path 24 and the first reverse rotation signal path 25 are connected in parallel to the common signal path 30 extending from the CPU, whereas the first forward conversion signal path 23 and The second reversal signal path 26 is directly connected to the CPU (that is, not via a common signal path).

Then, only when both the output signal from the common signal path 30 (that is, the restriction circuit 40 described later) and the output signal from the first forward conversion signal path 23 are input to the second forward conversion signal path 24, the second is input. The forward rotation opening / closing means 14 is provided with a first AND circuit 31 that outputs an energization command signal. Further, only when both the output signal from the common signal path 30 (that is, the limiting circuit 40 described later) and the output signal from the second reversing signal path 26 are input to the first reversing signal path 25, the first is A second AND circuit 32 that outputs an energization command signal is provided in the reversing opening / closing means 15.

Further, the above-mentioned switches SWm, SWa, and SWb of the controller 8 are connected to the electronic control unit U. The electronic control unit U is powered by the battery 10 and can drive and control the motor M based on the operation inputs to the switches SWm, SWa, and SWb of the controller 8.

For example, when the forward / reverse selection switch SWm is selected and held at the forward rotation selection position and either the left or right drive switch SWa or SWb is pressed and turned on, it corresponds to the pressed drive switch. The CPU of the electronic control unit U outputs a control signal, that is, a constant voltage current command value a to the common signal path 30, and outputs an energization command signal to the first forward conversion signal path 23. In response to this, the energization command signal is output from the first AND circuit 31 to the second forward rotation opening / closing means 14, and the energization command signal is directly output from the CPU to the first forward rotation opening / closing means 13. Both opening / closing means 13 and 14 are closed. As a result, the motor forward diversion circuit from the battery 10 to the ground 9 via the upstream portion of the second connection path 12, the second energization path 22, the motor M, the first energization path 21 and the downstream portion of the first connection path 11 It conducts and drives the motor M in the forward direction.

On the other hand, when either the left or right drive switch SWa or SWb is pressed and turned on while the forward / reverse selection switch SWm is selected and held at the reverse selection position, the electron corresponding to the pressed drive switch is turned on. From the CPU of the control unit U, a control signal, that is, a current command value a having a constant voltage is output to the common signal path 30, and an energization command signal is output to the second reversal signal path 26. In response to this, the energization command signal is output from the second AND circuit 32 to the first reversing opening / closing means 15, and the energizing command signal is directly output from the CPU to the second reversing opening / closing means 16. The opening / closing means 15 and 16 are closed. As a result, the motor reversal circuit from the battery 10 to the ground 9 via the upstream portion of the first connection path 11, the first energization path 21, the motor M, the second energization path 22 and the downstream portion of the second connection path 12 is provided. It conducts and drives the motor M in reverse.

Therefore, when the load current of the motor M exceeds a predetermined stop current value I ₁ when the motor M is driven in the forward or reverse direction, the electronic control unit U sets the duration t of the exceeded state. It is measured by the timer means T in the unit U, and the CPU determines whether or not the duration t is equal to or longer than the predetermined time t ₀ . In this case, as the predetermined time t ₀ , a time (for example, 100 msec) longer than the time when the inrush current at the time of starting the motor exceeds the stop current value I ₁ is set in advance in the CPU. The CPU and the timer means T cooperate with each other to form the stop means 50 of the present invention.

That is, the stop means 50 outputs a signal for stopping the energization (that is, continuing to cut off the energization) to the energization cutoff means X only when the duration t becomes the predetermined time t ₀ or more (in the present embodiment). , The output of the current command value a output from the CPU to the common signal path 30 is stopped, and the output of the energization command signal from the CPU to the first forward / reverse switching means 13 and the second reverse rotation opening / closing means 16 is also stopped). It is possible to exhibit a noise response function that does not immediately stop all energization in response to a short-time increase in load current (noise, for example, inrush current) due to disturbance or the like. Therefore, as will be described later, when the load current exceeds the predetermined stop current value I ₁ for a short time (that is, a time shorter than the predetermined time t ₀ ), the energization to the motor M is completely stopped. Therefore, the opening / closing operation of the seat S is not interrupted.

Further, the electronic control unit U includes a limiting circuit 40 as a limiting means that can be operated so as to intermittently limit the energization of the motor M when the motor M is driven in the forward or reverse direction. In the drive process of the motor M, the limiting circuit 40 approaches a time when the load current of the motor M approaches a predetermined limiting current value I ₃ higher than the stop current value I ₁ (particularly, in the present embodiment, the stop current value I ₁ ). When the limit start current value I ₂ higher than the limit current value I ₃ and lower than the limit current value I 3 is exceeded), the operation state is established. Then, the limiting circuit 40 controls the energization cutoff means X so that the energization to the motor M is intermittently cut off even if the current command value a is in the output state when this is in the operating state (more specifically). In other words, it exerts an energization suppression function that intermittently stops the output of the energization command signal output to the opening / closing means 14, 15.). As the limit current value I ₃ , a current value that is substantially the same as or relatively close to the inrush current normally assumed when the motor M is started is set.

The limiting circuit 40 has a breaking time adjusting function that lengthens the breaking time t _X of energization as the load current of the motor M approaches the limiting current value I ₃ in the above operating state. With this adjustment function, when the load current of the motor M approaches the limit current value I ₃ , the increase in the load current can be suppressed to a current value equal to or slightly lower than the limit current value I ₃ , for example. The inrush current at the time of starting the motor is also suppressed to a current value equal to or slightly lower than the limit current value I ₃ .

Further, as will be described later, the limiting circuit 40 has a control start time for intermittently interrupting the energization of the motor M based on a waveform signal having a constant amplitude and period and a load current (in the present embodiment, the start time is set to the start time). Set the limit start current value I ₂ ) used to determine and the cutoff time t _X of energization.

Next, an example of the limiting circuit 40 will be specifically described. The limiting circuit 40 is provided in the above-mentioned common signal path 30 in the electronic control unit U.

In the middle of the common signal path 30, the measured values output by the ammeters SE1 and SE2 are subtracted from the constant current command value a output from the CPU when the motor M is rotated forward or reverse as described above. An adder circuit 27 is provided. That is, in the present embodiment, the current command value a (constant voltage) output from the CPU to the common signal path 30 when the motor M rotates, and the measured values output by the ammeters SE1 and SE2 (that is, the above-mentioned voltmeter). The voltage obtained by adding the detected voltage) and the negatively inverted voltage is output from the adder circuit 27. Since the current command value a is a value for determining the limit current value I ₃ , the current command is different for each motor for a plurality of models of motors M having different limit current values I ₃ . The value a is set.

Further, the common signal path 30 is provided with a comparison circuit 28 on the downstream side of the addition circuit 27 and on the upstream side of the second forward rotation signal path 24 and the first reverse rotation signal path 25. The comparison circuit 28 adds the output voltage from the waveform signal generation circuit 29, which continues to output a triangular wave-shaped voltage signal as a waveform signal whose amplitude and period (for example, frequency is 10 kHz) are constant when the motor M rotates, and the above addition. Compare with the output voltage from the circuit 27. When the load current of the motor M is relatively small and the voltage of the latter is higher than the voltage of the former, the comparison circuit 28 outputs a predetermined signal to the AND circuits 31 and 32, and the load current of the motor M. When the voltage of the latter drops below the voltage of the former as the voltage increases, the output of the predetermined signal is stopped.

As described above, the limitation circuit 40 of the present embodiment includes at least the waveform signal generation circuit 29 described above, and the addition circuit 27 and the comparison circuit 28 on the common signal path 30.

Thus, the first AND circuit 31 outputs a predetermined energization command signal when both the predetermined signal from the comparison circuit 28 and the output signal from the first forward diversion signal path 23 are input to the predetermined AND circuit 31. Then, the second forward rotation opening / closing means 14 is closed, and if not, the output of the energization command signal is stopped to open and operate the second forward rotation opening / closing means 14 to open the second connection path 12. Cut off. On the other hand, the second AND circuit 32 outputs a predetermined energization command signal when both the predetermined signal from the comparison circuit 28 and the output signal from the second reversal signal path 26 are input to the predetermined signal. The first reversing opening / closing means 15 is closed, and if not, the output of the energization command signal is stopped to open the first reversing opening / closing means 15 to shut off the first connection path 11.

Next, the operation of this embodiment will be described. Now, when the forward / reverse selection switch SWm of the controller 8 is selected and held at the forward rotation selection position and at least one of the left and right drive switches SWa and SWb is pressed and turned on, the pressed drive switch is turned on. From the CPU of the electronic control unit U corresponding to the above, a predetermined current command value a is output to the common signal path 30, and a predetermined energization command signal is output to the first forward conversion signal path 23. When the first and second forward rotation opening / closing means 13 and 14 are closed in response to this, the battery 10, the upstream portion of the second connection path 12, the second connection path 22, the motor M, and the first connection path are closed. The motor forward rotation circuit leading to the ground 9 via the downstream portion of the 21 and the first connection path 11 conducts forward rotation driving the motor M to open the seat S.

An example of the time change of the load current when the forward rotation operation of the motor M is performed from the closed position Sc of the seat S to the open position So is shown in the timing chart (see solid line) of FIG. In this change over time of the load current, the first sudden peak indicates the inrush current at the start of the motor M, and the last peak is the load due to the seat S reaching the opening position So (opening limit). The sudden increase in current indicates a state where it has reached a plateau near the limit current value I ₃ , and the sudden decrease in current immediately after that means that the energization is cut off due to the passage of the above-mentioned duration t ₀ .

On the other hand, when either the left or right drive switch SWa or SWb is pressed and turned on while the forward / reverse selection switch SWm is selected and held at the reverse selection position, the electron corresponding to the pressed drive switch is electronic. The CPU of the control unit U outputs a predetermined current command value a to the common signal path 30, and outputs a predetermined energization command signal to the second reversal signal path 26. When the first and second reversing opening / closing means 15 and 16 are closed in response to this, the battery 10 leads to the upstream portion of the first connection path 11, the first connection path 21, the motor M, and the second connection path. The motor reversing circuit leading to the ground 9 via the downstream portion of the 22 and the second connection path 12 conducts, drives the motor M in the reverse direction, and closes the seat S.

The time change of the load current when the reverse rotation operation of the motor M is performed from the opening position So to the closing position Sc of the seat S is the same at the initial stage and the final stage as in the case of the normal rotation of the motor M. However, the intermediate period is the curve shown by the chain line in FIG.

Then, the load current at the time of forward rotation / reverse rotation of the motor M is measured by the ammeters SE1 and SE2, and the measured value is fed back to the CPU of the electronic control unit U and the limiting circuit 40.

Therefore, during the forward or reverse rotation of the motor M, [1] disturbance, for example, an inrush current is generated, an obstacle such as a stone hits the seat S during its opening and closing, or a gust of wind blows. When the load temporarily increases suddenly, or when [2] the seat S reaches the open position So or the closed position Sc and cannot be opened or closed any more, the load current of the motor M suddenly increases. It changes and exceeds a predetermined stop current value I ₁ .

In that case, the duration t in the state where the load current exceeds the stop current value I ₁ is measured by the electronic control unit U, but in the case of the above [1], the duration t is the predetermined time t ₀ (for example, 100 msec). ), The CPU continues to output the current command value a and the energization command signal to the signal path 23 or 26, so that the energization state to the motor M continues. Further, in the case of the above [2], when the duration t becomes the predetermined time t ₀ (for example, 100 ms) or more, the CPU immediately outputs the current command value a and energizes the signal path 23 or 26. Stops the output of the command signal. As a result, the energization command signal is no longer output from the electronic control unit U to the opening / closing means 14 or 15 during the closing operation, so that the opening / closing means 14 or 15 that has been closed until then is opened to energize the motor M. Will be completely stopped.

The count (measurement) of the duration t is the count time before each time the load current exceeds the stop current value I ₁ (that is, each time the load current exceeds the stop current value I ₁ ). Is reset (that is, the time data counted before that is erased), and then the process is started. For example, if the load current exceeds the stop current value I ₁ again within a short period from the start of counting the duration t and before reaching the predetermined time t ₀ , the count time up to that point is reset and continued. The time t count starts from 0 seconds.

Thus, when the load current of the motor M exceeds the predetermined stop current value I ₁ , it is confirmed that the exceeded state continues for a predetermined time t ₀ , and then the energization cutoff means X energizes the motor M. Since the motor M is completely stopped, it is possible not only to prevent seizure of the motor M and the energization circuit portion due to the continuous increase of the load current of the motor M, but also the load current of the motor M momentarily (because of disturbance or the like (). That is, even if the stop current value I ₁ is exceeded (only for a time shorter than the predetermined time t ₀ ), the inconvenience that the energization to the motor M is immediately stopped completely can be avoided, and the seat S is opened and closed due to the disturbance or the like. Can be effectively prevented from being temporarily interrupted. As a result, the seat S can be smoothly opened and closed while avoiding the continued overload state of the motor M.

By the way, in the electronic control unit U of the present embodiment, when the load current of the motor M exceeds the limit start current value I ₂ which is higher than the stop current value I ₁ and lower than the predetermined limit current value I ₃ , the motor M A limiting circuit 40 that operates to limit the energization to the motor M is provided, and the limiting circuit 40 energizes the motor M when the current limiting circuit 40 is in the operating state, even if the current command value a is in the output state. The current cutoff means X (particularly, the opening / closing means 14 and 15) are controlled so that the current can be cut off intermittently. Moreover, in the operating state of the limiting circuit 40, the cutoff time t _X of the energization is set to become longer as the load current approaches the limiting current value I ₃ , and the increase in the load current is suppressed.

Next, the energization suppression function by the limiting circuit 40 will be described with reference to the timing chart of FIG. In FIGS. 6A to 6D, the load current of the motor M rapidly increases due to the disturbance (for example, reaching the open position So or the closed position Sc of the seat S), and the limit start current value I ₂ is set. When the value is exceeded, the limiting circuit 40 shows a state for a relatively short period before and after starting the energization suppression function that intermittently cuts off the energization of the motor M.

In particular, FIG. 6A shows an added value of the current command value a and the negatively inverted ammeter SE1 and SE2 when the load current of the motor M increases (that is, the addition circuit 27). Output) shows the time change. Further, FIG. 6B shows an image of the process of superimposing and comparing the added value and the triangular wavy signal from the waveform signal generation circuit 29 in the comparison circuit 28. In order to make it easier to understand, as is clear from the figure corresponding to FIG. 5 shown in the lower part of FIG. 6, the time width (horizontal axis) is considerably expanded and the current change (vertical axis) is also drawn considerably exaggerated.

Further, in (C), the energization command signal is intermittently output in a pulse shape from the comparison circuit 28 (hence, and circuit 31 or 32) only when the triangular wavy signal from the waveform signal generation circuit 29 is lower than the above addition value. The opening / closing means 14 and 15 can be intermittently opened / closed based on the output change. Further, (D) shows the change with time of the motor load current (that is, the current flowing through the energization paths 21 and 22) at the same time as (A) to (C).

Therefore, in the intermittent opening / closing control for the opening / closing means 14 and 15 described above, after the load current of the motor M exceeds the stop current value I ₁ (that is, during the timing of the duration t), the limiting current value I ₃ The control is started shortly before reaching (that is, when the triangular wavy signal from the waveform signal generation circuit 29 becomes lower than the above addition value), and therefore, the load current of the motor M at the control start time. The value becomes the limit start current value I ₂ .

In this way, when the load current of the motor M exceeds the limit start current value I ₂ , the period in which the addition value is low and the period in which the addition value is high are alternately repeated in a short cycle with respect to the triangular wavy signal from the waveform signal generation circuit 29. As a result, the non-output state and the output state of the control signal are alternately repeated in a short cycle from the comparison circuit 28 (hence, AND circuits 31, 32), so that the energization to the motor M is interrupted according to the output stop period. Is blocked. In this case, as the load current approaches a predetermined limiting current value I ₃ which is higher than the limiting start current value I ₂ (that is, the added value becomes lower), the added value increases with respect to the triangular wavy signal from the waveform signal generation circuit 29. The low period becomes longer, and the intermittent output stop period of the energization command signal from the comparison circuit 28 (and therefore the AND circuits 31, 32) becomes longer and longer corresponding to this period. Therefore, as the load current of the motor M approaches the limit current value I ₃ , the cutoff time t _X of the energization of the motor M is set longer, and the increase of the load current can be suppressed reasonably and accurately. ..

Thus, even if the limit current value I ₃ is suppressed to a low level, by setting the predetermined time t ₀ longer than the time when the inrush current exceeds the stop current value I ₁ , the situation of power interruption due to the inrush current can be prevented. While avoiding it, it is possible to reliably suppress the increase in the load current of the motor M to the same extent as or slightly lower than the limit current value I ₃ , and for example, the inrush current at the time of starting the motor is also equivalent to the limit current value I ₃ . Or it can be suppressed to a slightly lower level. As a result, it is possible to effectively prevent seizure of the motor M and the energization circuit portion due to the excessive current, and it is not necessary to set the stop current value I ₁ sufficiently higher than the inrush current. The durability of the motor M and the like can be improved by suppressing the frequency at which the load current increases excessively.

Further, as described above, the energization suppression control in which the energization to the motor M is intermittently cut off is executed shortly before the load current reaches the limiting current value I ₃ (that is, when the limiting start current value I ₂ is exceeded). However, in the control process, by lengthening the energization cutoff time t _X as the current limit value I ₃ approaches, the increase in the load current is suppressed so as to reach a plateau immediately before the limit current value I ₃ , so that the motor M is used. The rotation of the motor M (and thus the seat opening / closing operation) can be decelerated before the energization of the motor M is completely stopped, and the shock caused by the sudden change in the seat opening / closing speed can be suppressed.

When it is confirmed that the duration t is equal to or longer than the predetermined time t ₀ during the intermittent suppression of energization of the load current, the energization of the motor M is completely stopped.

The intermittent energization suppression function by the limitation circuit 40 described above is started when the inrush current momentarily exceeds the limitation start current value I ₂ even when the motor M is started. In this case, the inrush current is started. Is suddenly decreased immediately after that, so that the period when the output of the addition circuit 27 (that is, the above addition value) is low with respect to the triangular wavy signal from the waveform signal generation circuit 29 ends in a very short time when the motor is started. Therefore, the energization suppression function by the limiting circuit 40 is completed in a short time. At this time, since the predetermined time t ₀ is set longer than the time when the inrush current exceeds the stop current value I ₁ , the energization to the motor M does not stop.

By the way, the ammeters SE1 and SE2 are arranged in or near the controller 8 in the driver's seat of the dump truck V, and the external wiring connecting the ammeters SE1 and SE2 and the motor M on the packing box 2 side. Is often handled in an exposed state over a wide area on the outer surface of the vehicle body. In particular, in the case of the dump truck V, in order to dump the packing box 2 to the rear, it is necessary to route the external wiring for a long time via the periphery of the dump hinge located at the rear end of the vehicle body.

Therefore, there is a risk that the external wiring will be short-circuited due to damage to the insulation due to contact with other objects. An overcurrent may flow in the connection paths 21 and 22, but the ammeters SE1 and SE2 in the connection paths 21 and 22 on the downstream side of the short-circuited portion cannot detect the overcurrent. For example, if only the first current meter SE1 is provided for detecting the load current of the motor M, it is downstream from the short-circuited portion SP1 or SP2 when the motor M rotates in the normal direction (that is, the opening / closing means 13 and 14 are closed). If the overcurrent cannot be detected, and if only the second current meter SE2 is provided, it will be on the downstream side of the short-circuited portion SP1 or SP2 when the motor M is reversed (that is, the opening / closing means 15 and 16 are closed). There is a risk that the overcurrent cannot be detected.

However, in the present embodiment, since the pair of current meters SE1 and SE2 capable of separately detecting the load current of the motor M are individually provided in any of the first and second connection paths 21 and 22, when the motor rotates in the normal direction. Even if the load current flowing through the motor M is in the opposite direction at the time of reversal, the overcurrent caused by the short circuit of the external wiring connected to the motor M on the vehicle packing box 2 can be accurately detected by either of the current meters SE1 and SE2. It becomes detectable.

Although the embodiments of the present invention have been described above, the present invention can make various design changes without departing from the gist thereof.

For example, in the above-described embodiment, the opening / closing means 13, 14; 15, 16 using the FET (field effect transistor) as the energizing cutoff means X are shown, but the opening / closing means constituting the energization cutoff means X is implemented. The form is not limited, and various electronic components (for example, a relay switch, etc.) that perform the same circuit opening / closing function can be used.

Further, in the above embodiment, the dump truck V is exemplified as a vehicle on which the packing box 2 is mounted, but the present invention can be applied to various vehicles with a packing box other than the dump truck.

Further, in the above embodiment, the seat S is pivotally supported on the left and right side plates 3 of the packing box 2 so as to be openable and closable, but the present invention shows the front plate (for example, the front panel) or the rear of the packing box 2. It can also be applied to a vehicle with a luggage box in which a seat is swingably supported on a plate (for example, a tailgate).

Further, in the above-described embodiment, the controller 8 for arbitrarily operating and inputting the opening and closing of the seat S is arranged in the driver's seat of the vehicle, but the installation location of the controller is not limited to the embodiment and the worker. May be installed in an appropriate place where the vehicle can be arbitrarily operated, for example, the vehicle body frame 1 or the packing box 3. Further, in the above embodiment, the ammeters SE1 and SE2 are provided in or near the controller 8, but the installation location of the ammeter is not limited to the embodiment.

Further, in the above embodiment, in order to simplify the circuit configuration by sharing the limiting circuit 40 with respect to the second forward conversion signal path 24 and the first reverse rotation signal path 25, the second forward conversion signal path 24 and the first are used. Although a limiting circuit 40 is provided in a common signal path 30 for connecting a reverse signal path 25 in parallel to the CPU, in the present invention, the second forward conversion signal path 24 and the first reverse signal path 25 are connected to the CPU. It may be directly connected to (that is, not via the common signal path 30) to link the limiting circuit 40 to each of the signal paths 24 and 25.

Further, in the above-described embodiment, the waveform signal having a constant amplitude / period (that is, the waveform signal generation circuit 29) is set as the limit start current value I ₂ that determines the start timing of the energization suppression control that intermittently cuts off the energization of the motor M. Although the variable set based on the output) and the load current of the motor M is used, in the present invention, the limiting start current value I ₂ is higher than the stop current value I ₁ and the limiting current value I ₃ You may use a constant value lower than.

Further, in the above embodiment, the current command value a, the output waveform signal of the waveform signal generation circuit 29, etc. are set so that the limit start current value I ₂ is higher than the stop current value I ₁ and lower than the limit current value I ₃ . However, in the present invention, the current command value a, the output waveform signal of the waveform signal generation circuit 29, and the like are set so that the limit start current value I ₂ is lower than the stop current value I ₁ . You may. However, even in that case, the load current when the energization of the motor M is completely stopped is set to be higher than the stop current value I ₁ and lower than the limit current value I ₃ .

Further, in the above embodiment, the electronic control unit U is built in the controller 8 as an example, but the installation site of the electronic control unit U is not limited to the embodiment, and the vehicle is in a suitable place outside the controller 8 (for example, the driver's seat, etc.). It may be installed in the packing box, on the vehicle body frame near the packing box, etc.).

Further, in the above embodiment, the waveform signal output from the waveform signal generation circuit 29 is used as a triangular wave signal, but in the present invention, other waveform signals such as a sinusoidal signal or a square wave signal can also be used. Is.

Further, in the above embodiment, in order to reliably detect an overcurrent when the external wiring connected to the motor M on the vehicle packing box is short-circuited, the load current of the motor is applied to the pair of energization paths 21 and 22 sandwiching the motor M. Although the pair of detection sensors SE1 and SE2 that can be detected separately are provided respectively, the present invention may be applied to the one in which the current meters SE1 or SE2 are provided only in one of the energization paths 21 or 22. good.

Further, in the above embodiment, when the load current of the motor M exceeds the predetermined stop current value I ₁ , the duration t of the exceeded state is measured, and the duration t is set to the predetermined time t ₀ or more. However, in the present invention, such control is omitted, that is, the stopping means 50 is used so that the load current of the motor M is a predetermined stop current value. It is also possible to control the power cutoff means X to output a command signal to stop the power supply to the motor M when I ₁ is exceeded.

Further, in the above embodiment, when the load current of the motor M exceeds the predetermined stop current value I ₁ , the stop means 50 responds to the duration t of the exceeded state becoming the predetermined time t ₀ or more. Although the control for outputting the command signal for stopping the energization of the motor M to the energization cutoff means X is executed from the time when the energization to the motor M is started, in the present invention, such control is performed on the motor M. The execution may be started after the energization start time (the control is started after the set time elapses from the energization start of the motor M) . For example, if the above control is set to start execution after the lapse of the required time from the start of energization of the motor M to the end of the inrush current, the inrush current sets the stop current value I ₁ for a predetermined time when the motor starts. Even if it exceeds t ₀ , the energization of the motor M can be prevented from being stopped. As a result, for example, even if the predetermined time t ₀ is set shorter than the time when the inrush current exceeds the stop current value I ₁ , it corresponds to the inrush current while avoiding the stoppage of energization of the motor M due to the inrush current. The excessive current can be suppressed by the limiting circuit 40. Then, the predetermined time t ₀ can be set shorter than the time when the inrush current exceeds the stop current value I ₁ as described above, or the predetermined time t ₀ can be set as the inrush current value I ₁ as in the above embodiment. Since it is possible to set the time longer than the time exceeding the above, the degree of freedom in setting the predetermined time t ₀ is increased accordingly.

Further, in the present embodiment, the limiting circuit 40 as the limiting means is in an operating state when the load current approaches the limiting current value I ₃ (that is, exceeds the limit start current value I ₂ lower than the limit current value I ₃ ). However, in the present invention, the control for intermittently interrupting the energization of the motor M is started, but in the present invention, the energization of the motor M is performed even before the load current approaches the limit current value I ₃ (for example, the energization of the motor M is performed). The limiting means, that is, the limiting circuit 40 may be activated (from the beginning) to start the control for intermittently cutting off the current. In this case, for example, the PWM control for intermittently controlling the energization of the motor M at a constant cycle and a constant energization cutoff time is executed immediately after the start of energization of the motor M, whereby the motor M is operated at a constant maximum speed. When the load current approaches the limit current value I ₃ during the rotation drive, the cutoff time of the energization may be lengthened as the load current approaches the limit current value I ₃ . In the above case, the control for intermittently interrupting the energization can be started without using the limit start current value I ₂ .

Further, in the above embodiment, the duration t in the state where the load current of the motor M exceeds the stop current value I ₁ is measured, and the motor M is energized according to the duration t becoming the predetermined time t ₀ or more. Although the stop means 50 for outputting the stop command signal to the energization cutoff means X (that is, the opening / closing means 13 to 16) is composed of the CPU and the timer means T, in the present invention, the stop circuit is different from the CPU. In addition, the function of determining whether or not the duration t measured by the timer means T has reached the predetermined time t ₀ or more is provided, and as the duration t becomes the predetermined time t ₀ or more, the stop circuit is used. A command signal for stopping the energization may be output to the energization cutoff means X (that is, the opening / closing means 13 to 16). As described above, since the stop means 50 can be configured by using a CPU or by using a stop circuit different from the CPU, the degree of freedom in design can be increased accordingly.

Further, in the above embodiment, the energization cutoff means X (that is, the energization cutoff means X) is used so that the energization of the motor M is intermittently cut off and the cutoff time t _X of the energization becomes longer as the load current approaches a predetermined limit current value I ₃ . Although the limiting means for controlling the opening / closing means 13 to 16) is shown to be configured by the limiting circuit 40 different from the CPU, in the present invention, the limiting circuit 40 is omitted to form the function of the limiting circuit 40. The CPU may be responsible for the same function. As described above, since the limiting means can be configured by using the limiting circuit 40 or by using the limiting circuit 40 in combination, the degree of freedom in design can be increased accordingly.

I ₁ ... Stop current value I ₃ ... Motor limit current value M ... Motor Ma, Mb ... Pair of power receiving units S ... Sheet Sc ... Closed position So ... ... Open position SE1, SE2 ... 1st and 2nd ammeters (1st and 2nd detection sensors)
t ・ ・ ・ ・ ・ Duration t ₀・ ・ ・ ・ Predetermined time t _X・ ・ ・ ・ Cutoff time U ・ ・ ・ Electronic control unit (control device)
V ... Dump truck (vehicle)
X ・ ・ ・ ・ ・ Power cutoff means 1 ・ ・ ・ ・ ・ Body frame 2 ・ ・ ・ ・ ・ Packing box 3 ・ ・ ・ ・ ・ Left and right side plates (side plates)
10 ... Battery 21 and 22 ... 1st and 2nd energization paths (pair of energization paths)
40 ... Restriction circuit (restriction means)
50 ... Stop means

Claims (1)

It is mounted on the vehicle body frame (1) of the vehicle (V) and is pivotally supported by a packing box (2) having an opening (O) on the upper surface, and has a predetermined opening position (So) with respect to the opening (O). From the seat (S) that can be opened and closed between the closed position (Sc), the electric motor (M) that opens and closes the seat (S), and the battery (10) for this motor (M). In an automatic seat opening / closing device in a vehicle cargo box provided with an energization cutoff means (X) capable of cutting off the energization and a control device (U) capable of controlling the operation of the energization cutoff means (X).
When the load current of the motor (M) exceeds a predetermined stop current value (I ₁ ), the control device (U) stops the energization of the motor (M) by the energization cutoff means (X). It is equipped with a stop means (50) that controls the output of a command signal.
The stop means (50) starts its control after a set time has elapsed from the start of energization of the motor (M), and the load current of the motor (M) exceeds a predetermined stop current value (I ₁ ). At times, the duration of the exceeded state is measured, and when the duration exceeds a predetermined time, a command signal for stopping the energization is output to the energization cutoff means (X) . , Automatic seat opening / closing device for vehicle luggage boxes.

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