JP4968466B2 - Vehicle seat air conditioner - Google Patents

Description

  The present invention relates to a vehicle seat air conditioner, and more particularly to a vehicle seat air conditioner provided with a seat heater.

A seat heater provided on a seat in a vehicle compartment is connected in series with a thermostat and an auxiliary heater as described in Patent Document 1 below, for example. In the component circuit including the seat heater described in Patent Document 1, when the thermostat is heated by the auxiliary heater when the seat heater is energized, and the thermostat reaches a predetermined temperature or more, it is used to prevent overheating that constitutes the thermostat. The bimetal plate is reversed, the energization path of the seat heater is interrupted, and energization to the seat heater is prohibited. For this reason, it is possible to effectively prevent heat generation of the seat when an abnormality occurs in the constituent circuit of the seat heater and the energization path of the seat heater is not cut off.
JP 2003-109721 A

  However, in the configuration circuit including the seat heater described in Patent Document 1, an auxiliary heater is provided as one of means for prohibiting energization of the seat heater. For this reason, the electric power that can be used for the seat heater is reduced by that amount, and it is still insufficient as a configuration that efficiently uses more electric power for heating. This problem has also occurred in the vehicle seat air conditioner including the seat heater.

  The subject of this invention is providing the vehicle seat air conditioner which can use more electric power efficiently for heating.

Means for Solving the Problems and Effects of the Invention

  In order to solve the above problems, a vehicle seat air conditioner according to the present invention includes a seat heater provided in a seat in a vehicle interior, a protection relay that allows or prohibits energization of the seat heater, and energizes the seat heater. A sheet control means for driving, wherein the sheet control means superimposes a check pulse of a constant period on a drive signal for energizing and driving the seat heater and outputs a combined drive signal to the seat heater. And, based on the composite drive signal output by the signal output means, a pulse detection means for detecting a check pulse in the composite drive signal, and the sheet on the condition that the check pulse is not detected by the pulse detection means Switching means for switching off the protection relay so that energization to the heater is prohibited And features.

  In this vehicle seat air conditioner, the signal output means superimposes a check pulse with a constant period on the drive signal for energizing and driving the seat heater, and outputs the combined drive signal to the seat heater. In this case, when an abnormality such as a power supply short circuit does not occur in the seat heater component circuit, for example, a check pulse in the composite drive signal is detected by the pulse detection means. On the other hand, when an abnormality such as a power supply short circuit occurs in the constituent circuit of the seat heater, the check pulse is not detected by the pulse detection means due to the disappearance of the L level of the check pulse. In this case, the protection relay is switched off by the switching means so that energization of the seat heater is prohibited.

  For this reason, when an abnormality occurs in the constituent circuit of the seat heater, the energization of the seat heater is prohibited, so that heat generation of the seat can be effectively prevented. In this case, since it is not necessary to use an auxiliary heater as a configuration for prohibiting energization of the seat heater, the power that can be used for the seat heater is increased by that amount, and more power can be efficiently used for heating. It is.

  In carrying out the present invention, the seat heater and the sheet control means are provided for each of a plurality of sheets, and each of the sheet control means superimposes the check pulse on a drive signal for energizing and driving the corresponding sheet heater. The composite drive signal may be output to the seat heater, and the pulse detection means of each of the sheet control means may be configured to detect the check pulses from each other.

  According to this, check pulses are mutually detected by the pulse detection means of each sheet control means. For this reason, for example, even when an abnormality occurs in one of the sheet control means, the check pulse detection function by the pulse detection means of the normal sheet control means can be secured with a simple configuration.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a block diagram of an embodiment in which the vehicle seat air-conditioning apparatus of the present invention is adopted for a D seat (driver seat) and a P seat (passenger seat). The apparatus includes the seat heater 11 and the D seat ECU 20 in the D seat, and the seat heater 31 and the P seat ECU 40 in the P seat.

  The seat heater 11 heats the seat portion of the D seat, is embedded in the seat portion of the D seat, and has one end connected to the positive terminal of the battery 50 via the D seat ECU 20. The end is connected to the negative terminal of the battery 50.

  The D seat ECU 20 includes a microcomputer 21 including a CPU, a ROM, a RAM, and the like and a drive circuit 22 that drives the seat heater 11 as main components. By turning on the ignition switch IGsw and the seat heater drive switch SHsw, the ROM, etc. 2 is repeatedly executed every predetermined short time, and a control signal corresponding to the execution is output to the drive circuit 22. The drive circuit 22 is connected to the plus terminal of the battery 50 via the power supply line Ld, and energizes and drives the seat heater 31 with a drive signal corresponding to the control signal of the microcomputer 21.

  The seat heater 31 heats the seat portion of the P seat, and is embedded in the seat portion of the P seat. The seat heater 31 is connected to the seat heater 11 in parallel with one end side of the battery 50 via the P seat ECU 40. The other end side is connected to the minus terminal of the battery 50.

  The P seat ECU 40 includes a microcomputer 41 including a CPU, a ROM, a RAM, and the like and a drive circuit 42 that drives the seat heater 31 as main components. By turning on the ignition switch IGsw and the seat heater drive switch SHsw, the ROM, etc. 2 is repeatedly executed every predetermined short time, and a control signal corresponding to the execution is output to the drive circuit 42. The drive circuit 42 is connected to the plus terminal of the battery 50 via the power supply line Ld, and energizes and drives the seat heater 31 with a drive signal corresponding to the control signal.

  An electromagnetic relay 60 is provided on the negative terminal side of the battery 50 of the seat heater 11 and the seat heater 31. The electromagnetic relay 60 (protection relay) includes a contact portion 61 connected in series with the seat heater 11 or the seat heater 31, and a coil portion 62 that opens and closes (turns on and off) the contact portion 61. The coil unit 62 has one end connected to the plus terminal of the battery 50 and the other end connected to the microcomputers 21 and 41 via the coil conducting wire Lc constituting the coil circuit, and the output voltage of the battery 50 is shown in the figure. The voltage is divided to a predetermined voltage level by a resistor to be omitted and is taken into the microcomputers 21 and 41.

  When the ignition switch IGsw and the seat heater drive switch SHsw are normally turned on, the terminals of the microcomputers 21 and 41 to which the other ends of the coil energization lines Lc are connected are set to the L level. As a result, a current flows through the coil conducting wire Lc, the coil portion 62 is in an excited state, and the contact portion 61 is turned on (closed state) as shown by a solid line in FIG. On the other hand, as will be described later, when the constituent circuits of the seat heaters 11 and 31 are abnormal, the terminals of the microcomputers 21 and 41 to which the other ends of the coil energization lines Lc are connected are set to the H level. As a result, no current flows through the coil energization line Lc, the coil portion 62 is in a non-excited state, and the contact portion 61 is switched off (opened) as indicated by a broken line in FIG.

  The drive circuit 22 of the D seat ECU 20 is connected to the microcomputer 21 via the signal lines L1 to L3 and the diode D1, and is connected to the microcomputer 41 via the signal lines L1, L2, L6 and the diode D1, and is driven. The drive signal output from the circuit 22 is input to the microcomputers 21 and 41, respectively.

  Similarly, the drive circuit 42 of the P seat ECU 40 is connected to the microcomputer 41 via the signal lines L4, L2, L6 and the diode D2, and is connected to the microcomputer 21 via the signal lines L4, L2, L3 and the diode D2. The drive signals output from the drive circuit 42 are input to the microcomputers 41 and 21, respectively.

  Next, the operation of the present embodiment configured as described above will be described. The D seat ECU 20 and the P seat ECU 40 repeatedly execute the seat overheat prevention program shown in FIG. 2 every predetermined short time by turning on the ignition switch IGsw and the seat heater drive switch SHsw. When the seat overheat prevention program of FIG. 2 is executed, as described above, the contact portion 61 of the electromagnetic relay 60 is in the on state, and the seat heaters 11 and 31 are both energized and driven. Since the contents of the overheating prevention of the D sheet and the P sheet by the execution of the sheet overheating prevention program are the same, hereinafter, the case where the D sheet is prevented from being overheated when the seat heater 11 is energized and driven by the D sheet ECU 20 will be described. This will be explained as a representative.

  The execution of the seat overheat prevention program is started in step S10, and in step S11, the D seat ECU 20 adds a drive signal to the seat heater 11 as shown in FIG. 10 ms to 20 ms), a check pulse that repeats the H level and the L level is output. In this case, when the drive signal for the seat heater 11 is at the H level and the check pulse is at the H level, the D seat ECU 20 has the combined drive signal at the H level, the drive signal for the seat heater 11 is at the H level, and the check pulse is at the L level. In this case, the composite drive signal is at L level, and when the drive signal of the seat heater 11 is at L level, the composite drive signal is at L level regardless of the level of the check pulse, that is, the composite drive signal. Both output signals are superimposed so that is the logical product of both output signals. Note that the cycle of the check pulse is extremely shorter than the cycle of the driving signal of the seat heater 11 (for example, 1 minute to 2 minutes). Therefore, even if the composite drive signal in which the check pulse is superimposed on the drive signal of the seat heater 11 is output to the seat heater 11, the energization drive of the seat heater 11 is hardly affected.

  Although the seat heater 11 is being energized, if the drive signal to the seat heater 11 is currently at L level, the sheet heater 11 is in a state in which overheating of the D sheet is prevented. And the energization drive to the seat heater 11 is maintained.

  On the other hand, when the drive signal to the seat heater 11 is currently at the H level (“Yes” in step S12), the processing from step S13 is executed. In step S13, it is determined whether or not a check pulse has been detected within a predetermined time in the combined drive signal input via the signal lines L1 to L3 and the diode D1. Here, the certain time is set to a time slightly longer than the certain period Tperiod of the check pulse. When the constituent circuits of the seat heater 11 are normal (for example, when not short-circuited), as shown in FIG. 4, a composite drive signal (signal when the seat heater 11 is operated) output to the seat heater 11 and a signal line The combined drive signal input to the microcomputer 21 via L1 to L3 and the diode D1 has the same waveform shape. Therefore, in this case, the microcomputer 21 always detects the check pulse in the composite drive signal, so that “Yes” is determined in step S13 and the energization drive to the seat heater 11 is maintained.

  On the other hand, when the constituent circuit of the seat heater 11 is abnormal, for example, as shown in part A of FIG. 1, the power supply line Ld to the drive circuit 22 and the drive signal output line are short-circuited due to solder scraps or the like. Or, for example, as shown in part B of FIG. 1, when the power short-circuits between the seat heater 11 and the coil energization line Lc due to the biting of the wire or the like, as indicated by the broken line in the composite drive signal of FIG. As a result, the L level of the check pulse disappears and the composite drive signal shows the H level.

  Therefore, in this case, since the check pulse in the composite drive signal is not detected by the microcomputer 21, “No” is determined in step S13, and the electromagnetic relay 60 is switched off in step S14. That is, the microcomputer 21 sets the terminal to which the other end of the coil energization line Lc is connected to the H level (see FIG. 4). As a result, no current flows through the coil energization line Lc, the coil portion 62 is de-energized, the contact portion 61 is switched off (open state), and the energization drive to the theta heat 11 is stopped.

  As is clear from the above description, in this embodiment, the drive signal for energizing and driving the seat heater 11 (seat heater 31) is constant by the execution of the process of step S11 by the D seat ECU 20 (P seat ECU 40). A cycle check pulse is superimposed and the combined drive signal is output to the seat heater 11 (seat heater 31). In this case, when an abnormality such as a power supply short circuit does not occur in the constituent circuit of the seat heater 11 (seat heater 31), a check pulse in the composite drive signal is detected by the D seat ECU 20 (P seat ECU 40). ("Yes" in step S13). On the other hand, when an abnormality such as a power supply short circuit occurs in the constituent circuit of the seat heater 11 (seat heater 31), a check pulse is generated by the D seat ECU 20 (P seat ECU 40) due to the disappearance of the L level of the check pulse. It is no longer detected (“No” in step S13). In this case, the electromagnetic relay 60 is switched off so that the energization of the seat heater 11 (seat heater 31) is prohibited by the execution of the process of step S14 by the D seat ECU 20 (P seat ECU 40).

  For this reason, when an abnormality occurs in the constituent circuit of the seat heater 11 (seat heater 31), energization to the seat heater 11 (seat heater 31) is prohibited, so heat generation of the D sheet (P sheet) is effective. It is possible to prevent. In this case, since it is not necessary to use an auxiliary heater as a configuration for prohibiting the energization of the seat heater 11 (seat heater 31), the electric power that can be used for the seat heater 11 (seat heater 31) increases correspondingly, and more It is possible to efficiently use electric power for heating.

  Moreover, in the said embodiment, the seat heater 11 and D seat ECU20 are provided corresponding to D seat, and the seat heater 31 and P seat ECU40 are provided corresponding to P seat. Then, in addition to the composite drive signal output from the drive circuit 22 being input to the microcomputer 21 of the D seat ECU 20, the composite drive signal output from the drive circuit 42 of the P seat ECU 40 is input to each composite. The check pulse in the drive signal can be detected. Similarly, in addition to the composite drive signal output from the drive circuit 42 being input to the microcomputer 41 of the P seat ECU 40, the composite drive signal output from the drive circuit 22 of the D seat ECU 20 is input, The check pulse in the combined drive signal can be detected.

  Thereby, for example, even when an abnormality occurs in the microcomputers 21 and 41 and the drive circuits 22 and 42, it is possible to ensure the check pulse detection function by the normal microcomputers 21 and 41 with a simple configuration. .

  In the above embodiment, it is configured to determine whether or not a check pulse is detected within a predetermined time in step S13 of FIG. 2, but instead, for example, a composite drive signal to be output is input. Whether the synthesized drive signal has the same waveform shape, whether the synthesized drive signal to be output and the input synthesized drive signal have the same check pulse generation timing, or a predetermined time The check pulses may be counted to determine whether the number of check pulses matches the required number.

  Moreover, although the said embodiment demonstrated the case where the vehicle seat air conditioner of this invention was employ | adopted as D seat seat (driver's seat) and P seat (passenger seat), for example, only in D seat seat The vehicle seat air conditioner of the present invention may be adopted, or the vehicle seat air conditioner of the present invention is applied to the rear seat in addition to the D seat (driver seat) and the P seat (passenger seat). It may be adopted.

The block diagram which shows one Embodiment of the vehicle seat air conditioner of this invention. The flowchart which shows the seat overheating prevention program performed by D seat ECU and P seat ECU of FIG. Explanatory drawing of the composite drive signal output from D seat ECU and P seat ECU of FIG. The time chart which shows the HL level between the synthetic | combination drive signal at the time of execution of the sheet | seat overheat prevention program of FIG. 2, the microcomputer terminal to which the coil part was connected, and a seat heater operation.

Explanation of symbols

D seat (driver's seat)
P seat (passenger seat)
IGsw Ignition switch SHsw Seat heater drive switch 11, 31 Seat heater 20 D Seat ECU (Seat control means, signal output means, pulse detection means, switching means)
40 P seat ECU (sheet control means, signal output means, pulse detection means, switching means)
21, 41 Microcomputer 22, 42 Drive circuit Ld Power supply line 50 Battery 60 Electromagnetic relay (protection relay)
61 Contact 62 Coil Lc Coil conduction lines L1-L6 Signal lines D1, D2 Diode

Claims (2)

A seat heater provided on the seat in the passenger compartment;
A protective relay that allows or prohibits energization of the seat heater;
Sheet control means for energizing and driving the seat heater,
The sheet control means includes a signal output means for superimposing a check pulse of a constant period on a drive signal for energizing and driving the seat heater and outputting a combined drive signal to the seat heater;
Pulse detection means for detecting a check pulse in the combined drive signal based on the combined drive signal output by the signal output means;
Vehicular seat air conditioning, further comprising: switching means for switching off the protective relay so that energization to the seat heater is prohibited on condition that the check pulse is not detected by the pulse detection means. apparatus.   The seat heater and the sheet control means are provided for each of a plurality of sheets, and each of the sheet control means superimposes the check pulse on a drive signal for energizing and driving the corresponding sheet heater, and a combined drive signal thereof 2. The vehicle seat air conditioner according to claim 1, wherein the pulse detection means of each of the seat control means detects the check pulses from each other.

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