JP2009234440A - Air cell drive and seat device for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air cell drive can stop a driving electric current when an air pump comes to be in a constrained state without attaching a breaker element of a PTC thermistor, etc. to a pump motor and can easily achieve other necessary controlling processes by linking them to stopping control of the driving electric current, and a seat device for a vehicle. <P>SOLUTION: The air cell drive is furnished with the air pump 12 to supply air to an air cell and an ECU 20 to supply the driving electric current to a motor 12A of the air pump. An excess current detection circuit 24 to carry out excess current detection against wiring to which the driving electric current is made to flow is provided on the ECU 20 and a micro computer 21 perform control to stop the driving electric current in accordance with a detection signal of this excess current detection circuit 24. The seat device for the vehicle is also provided. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an air cell driving device for supplying air to an air cell, and a vehicle seat device incorporating the air cell.

Conventionally, there is a vehicle seat in which an air cell is built in a seat so that the air cell can be inflated or deflated by a switch operation or the like. In a general air pump, when the air supply destination is full or the air discharge hole is clogged and the air pump is in a restrained state, excessive drive current continues to flow to the pump motor in the restrained state. For example, as shown in FIG. 4, for example, a temperature monitoring breaker such as a PTC (positive temperature coefficient) thermistor Rp is usually attached to the motor M (for example, Patent Document 1).
JP 2007-191045 A

  In various apparatuses using an air pump, there is a case where a request for applying a general-purpose DC motor to the pump motor may be made. In such a case, in order to realize the stopping operation of the drive current in a restrained state using a PTC thermistor or the like as described above, a general-purpose DC motor is modified and a temperature monitoring breaker sensor is attached to the DC motor. There is a need.

  Further, in the configuration in which the drive current stop operation is realized by the temperature monitoring breaker, it is difficult to detect the shutdown of the temperature monitoring breaker in the control device (for example, the electronic control unit (ECU) of the vehicle seat) that controls the operation of the air pump. Therefore, there is a problem that it is difficult to execute various control processes necessary when the pump motor is restrained by the control device.

  The present invention can prevent a situation in which an excessive drive current continues to flow to the pump motor while the air pump is in a restrained state without attaching a sensor such as a PTC thermistor to the motor, and the air pump is in a restrained state. An object of the present invention is to provide an air cell driving device and a vehicle seat device that can easily execute various control processes that are sometimes required.

In order to achieve the above object, the invention according to claim 1
An air pump for supplying air to the air cell;
A control unit connected to the motor of the air pump via a wiring to supply a drive current;
In an air cell driving device comprising:
The control unit includes
A control circuit for controlling the driving of the air pump;
A drive circuit for outputting a drive current to the motor of the air pump according to an instruction of the control circuit;
An overcurrent detection circuit for detecting that the drive current is overcurrent;
Is provided,
The control circuit includes:
When the overcurrent detection circuit detects an overcurrent, control is performed to stop the output of the drive circuit.

The invention according to claim 2 is the air cell driving device according to claim 1,
The air pump is
It is connected to supply air to the air cell through a joint having a pressure prevention hole,
The control unit includes
A disconnection detection circuit for detecting disconnection of the wiring is provided together with the overcurrent detection circuit.

The invention described in claim 3
A seat body with a built-in air cell;
A vehicle seat device comprising the air cell driving device according to claim 1.

  According to the present invention, since the control circuit performs stop control of the drive current based on the detection of the overcurrent by the overcurrent detection circuit, this may cause the air pump to be in a restrained state and continue to flow an excessive current to the pump motor. Avoided.

  Also, with this configuration, the control circuit can easily recognize that the air pump is in a restrained state, so that various control processing (for example, error processing and maintenance notification processing, etc.) associated with the occurrence of the restraint state can be performed. ) Can be easily realized by linking with the stop process of the drive current.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a diagram showing a configuration of an air cell and a driving unit thereof built in a vehicle seat according to an embodiment of the present invention.

  The vehicle seat according to the embodiment of the present invention is, for example, a seat such as a driver's seat, a passenger seat, or a rear seat of the vehicle, and one or a plurality of air cells are provided in the cushion of the seat surface or the backrest. 11 is provided. The vehicle seat includes an air pump 12 that supplies air to the air cell 11, a solenoid (solenoid actuator) 13 that discharges air from the air cell 11, an air cell 11, and an air pump 12, for example, on the back side of the seat surface. Further, a joint 14 for connecting the solenoid 13 and an ECU (electronic control unit) 20 (see FIG. 2) for controlling the driving of the air pump 12 and the solenoid 13 are provided. The air pump 12 and the air cell 11 are connected to the joint 14 via, for example, air tubes 15a and 15b. Moreover, ECU20, the air pump 12, and the solenoid 13 are electrically connected through the wiring of a harness.

  The air cell 11 is inflated by increasing pressure by injecting air, or squeezed by discharging air. And the hardness and shape of a sheet | seat change because the air cell 11 swells or squeezes in a sheet | seat.

  The air pump 12 incorporates a pump motor 12A made of, for example, a DC motor, and supplies air by exerting a pump action by the rotation of the pump motor 12A.

  The solenoid 13 opens or closes an exhaust hole 14a provided in the joint 14, for example. The solenoid 13 is in a state where no drive current flows, and the plunger 13b protrudes and closes the exhaust hole 14a by the action of the spring 13a. However, when the drive current flows, the plunger 13b retracts to open the exhaust hole 14a. As a result, air in the air cell 11 is released.

  The joint 14 is for sending air from the air pump 12 to the air cell 11, and a backflow prevention valve 14 b is provided in the middle so that the air in the air cell 11 does not flow back to the air pump 12 side. Further, a pressurization prevention hole 14c is provided on the connection side of the air pump 12 with respect to the backflow prevention valve 14b, and even when the air cell 11 becomes full, the air is released and the air pump 12 is in a restrained state (the pump motor 12A) The pump motor 12A is prevented from rotating even when the drive current flows.

  FIG. 2 is a block diagram showing the connection configuration of the ECU 20 and its periphery.

  The ECU 20 performs ground fault detection on the microcomputer 21 that performs the control operation, the drive circuit 22 that outputs the power supply voltage E2 supplied from the battery to the pump motor 12A, and the harness wiring connected to the pump motor 12A. A ground fault detection circuit 23 and an overcurrent & disconnection detection circuit 24 that performs disconnection detection and overcurrent detection on the harness wiring are provided. In addition, a drive circuit 25 for supplying the power supply voltage E2 supplied from the battery to the solenoid 13, a ground fault detection circuit 26 for the harness wiring connected to the solenoid 13, and an overcurrent & disconnection detection circuit 24 are provided.

  The ECU 20 is connected to an air up switch 17 and an air down switch 18 provided on the vehicle side via a harness. The air up switch 17 is a switch for inflating the air cell 11 in the seat, and the air down switch 18 is a switch for extracting air from the air cell 11.

  The microcomputer 21 includes a non-volatile memory storing a control program and control data, a CPU (Central Processing Unit) that executes the control program, and the like, and drive control processing of the pump motor 12A and the solenoid 13 by control processing by the CPU. Is supposed to run.

  The drive circuit 22 receives a command signal from the microcomputer 21 and supplies a drive current to the pump motor 12A based on the command signal or stops the drive current.

  The ground fault detection circuit 23 detects, for example, the voltage of the supply wiring for the drive current to the pump motor 12A. When the voltage falls below a predetermined threshold value, the ground fault detection circuit 23 notifies the microcomputer 21 that a ground fault has occurred. Is output.

  The overcurrent & disconnection detection circuit 24 detects disconnection of the harness connecting the ECU 20 and the pump motor 12A, or detects that the drive current output to the pump motor 12A is excessive, and according to these detections. A disconnection detection signal or an overcurrent detection signal is output to the microcomputer 21. For example, the detection of the disconnection is configured to detect a current flowing through the drive current supply wiring via a detection resistor or the like, and to output a disconnection detection signal when the detected value of this current becomes zero. Alternatively, when two currents are arranged in parallel with the pump motor 12A separately from the drive current supply wiring and a minute current is passed through the loop wiring, the current is cut off. It is also possible to adopt a configuration in which a disconnection detection signal is output based on the determination of disconnection. In the case of the former configuration, when the drive current is stopped, the state is the same as the disconnection detection. Therefore, for example, the microcomputer 21 inputs the disconnection detection signal only when the drive current is output, and stops the drive current. In such a case, the disconnection detection signal may be ignored.

  In addition, the configuration for detecting the overcurrent includes, for example, a detection resistor that converts a current flowing in the drive current supply wiring into a voltage, a filter circuit that removes noise from the voltage of the detection resistor, and a voltage of the detection resistor from which noise has been removed. And a comparator or the like that compares a predetermined threshold voltage. The threshold voltage is set to such a value that does not exceed when the normal pump motor 12A is driven and exceeds when the pump motor 12A is in a restrained state.

  A drive circuit 25, a ground fault detection circuit 26, and an overcurrent & disconnection detection circuit 27 corresponding to the solenoid 13 have substantially the same configuration as that of the pump motor 12A. The threshold value for detecting the overcurrent of the overcurrent & disconnection detection circuit 27 is set to a value corresponding to the current value when the coil of the solenoid 13 is short-circuited, for example.

  Next, the control operation of the vehicle seat configured as described above will be described.

  FIG. 3 shows a flowchart of the drive control process of the air cell 11 executed by the CPU (central processing unit) of the microcomputer 21.

  When the drive control process of the air cell 11 is started, the CPU of the microcomputer 21 first repeatedly executes the switch input process and the branch process according to the switch input by the loop process of steps S1 to S3. That is, the input port to which the air up switch 17 and the air down switch 18 are connected is confirmed (step S1), and if there is an ON signal of the air up switch 17, the process branches to a step for supplying air (step S2). If there is an ON signal of the air down switch 18, the process branches to a step for discharging air (step S3). If there is no switch ON signal input, the loop processing of steps S1 to S3 is repeated.

  If there is an ON signal of the air up switch 17 and the process branches to Yes in step S2, first, the CPU of the microcomputer 21 checks the value of the pump abnormality flag set in the nonvolatile memory or the like (step S4). This pump abnormality flag is a flag that is set to a value of “true” when a ground fault or disconnection is detected in the harness connected to the pump motor 12A, or when an output of an excessive drive current is detected. If the value of the pump abnormality flag is “true”, it is determined that the pump motor 12A cannot be driven, and the drive control process is terminated and the process proceeds to an error process.

  On the other hand, if the value of the pump abnormality flag is “false”, first, an ON signal is sent to the drive circuit 22 to supply a drive current from the drive circuit 22 to the pump motor 12A (step S5). As a result, the air pump 12 is activated and air is supplied to the air cell 11. When the supply of the drive current is started, a loop process including confirmation of the presence / absence of an overcurrent detection signal (step S6) and confirmation of elapse of a predetermined cycle time (for example, 1 second) (step S7) is then repeatedly performed. . If no overcurrent detection signal is input during this cycle time, the drive current is stopped after the elapse of this cycle time (step S8), and the process returns to step S1 again.

  Conversely, if the input of the overcurrent detection signal is confirmed during the above cycle time, the value of the pump abnormality flag is rewritten to “true” (step S9), and the drive current is immediately stopped (step S8). Return to step S1 again.

  For example, when the air up switch 17 is kept on by the processing in steps S1 to S9 described above, the driving current is continuously supplied for a predetermined cycle time in steps S5 to S8, whereby the air cell 11 is continuously sent to the air. In the meantime, for example, when the air cell 11 is full and the pressure prevention hole 14c is clogged with dust or the like and the air pump 12 is in a restrained state, an excessive current flows to the pump motor 12A. This is detected by the current & disconnection detection circuit 24, and an overcurrent detection signal is output to the microcomputer 21. The supply of drive current is immediately stopped by this overcurrent detection signal, and even if there is a subsequent ON operation of the air up switch 17, the drive current is not flowed by checking the pump abnormality flag, for example, The system is shifted to error processing in which notification of maintenance is required.

  In the loop processing of steps S1 to S3 in FIG. 3, if the ON signal of the air down switch 18 is confirmed, the process branches to Yes in the determination processing of step S3. First, a drive current is output to the solenoid 13 (step S10), the drive current is stopped after a predetermined cycle time (for example, 1 second) elapses (steps S11 and S12), and then again to step S1. Return.

  By the processing of steps S3, S10 to S12, the solenoid 13 is driven by the ON operation of the air down switch 18, and the air of the air cell 11 is released.

  As described above, according to the vehicle seat and the air cell drive device (air pump 12 and ECU 20) of this embodiment, the ECU 20 is provided with the overcurrent & disconnection detection circuit 24, and the drive current of the pump motor 12A is excessive in the ECU20. Therefore, when the air pump 12 is in a restrained state without incorporating a breaker element such as a PTC thermistor into the pump motor 12A. It is possible to prevent a disadvantage that an excessive drive current continues to be output.

  Further, the overcurrent detection by the overcurrent & disconnection detection circuit 24 allows the microcomputer 21 to easily recognize that the air pump 12 is in a restrained state. Therefore, there is an effect that other necessary control processing associated with the air pump 12 being in the restrained state can be easily realized by linking with the stop control of the drive current.

  Moreover, since the ECU 20 is usually provided with a disconnection detection circuit, a configuration for detecting an overcurrent can be added by adding a small number of parts by using this circuit. For example, the current detection resistor connected to the wiring for supplying the drive current to the pump motor 12A and the noise removal circuit are shared, and a comparator for comparing the voltage with the threshold for overcurrent detection is added. A current detection configuration can be added.

  The present invention is not limited to the above-described embodiment, and various modifications can be made. For example, in the above-described embodiment, once an overcurrent to the pump motor 12A is detected, if the maintenance is performed and the value of the pump abnormality flag is not reset, then the control content is such that the pump motor 12A cannot be driven. However, the control content may be such that the drive current is stopped as soon as an overcurrent to the pump motor 12A is detected, and the drive current can be supplied again after a while from the stop. As a result, for example, even when the overpressure is detected due to clogging of the pressure prevention hole 14c, after the air cell 11 is removed by driving the solenoid 13, the air pump 11 is driven again to activate the air cell 11. Air can be supplied until it is full.

  In addition, the detailed configuration shown in the embodiment can be changed as appropriate without departing from the spirit of the invention.

It is a partial sectional view showing the composition of the air cell built in the vehicular seat of the embodiment of the present invention, and its drive part. It is the block diagram which showed connection structure of ECU and its periphery. It is a flowchart which shows the drive control process of the air cell performed by CPU in a microcomputer. It is a figure which shows the circuit structure of the motor for the conventional air pump.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Air cell 12 Air pump 12A Pump motor 13 Solenoid 14 Joint 14c Pressure prevention hole 17 Air up switch 18 Air down switch 20 ECU
21 Microcomputer (control circuit)
22 Drive circuit 23 Ground fault detection circuit 24 Overcurrent & disconnection detection circuit

Claims (3)

An air pump for supplying air to the air cell;
A control unit connected to the motor of the air pump via a wiring to supply a drive current;
In an air cell driving device comprising:
The control unit includes
A control circuit for controlling the driving of the air pump;
A drive circuit for outputting a drive current to the motor of the air pump according to an instruction of the control circuit;
An overcurrent detection circuit for detecting that the drive current is overcurrent;
Is provided,
The control circuit includes:
An air cell drive device that performs control to stop the output of the drive circuit when the overcurrent detection circuit detects an overcurrent. The air pump is
It is connected to supply air to the air cell through a joint having a pressure prevention hole,
The control unit includes
2. The air cell driving device according to claim 1, further comprising a disconnection detection circuit that detects disconnection of the wiring together with the overcurrent detection circuit. A seat body with a built-in air cell;
A vehicle seat device comprising the air cell driving device according to claim 1.

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