In-vehicle radiant heater control apparatus

Patent metadata

Field	Value
Publication number	US-2016200172-A1
Application number	US-201414912116-A
Country	US
Kind code	A1
Filing date	Jul 1, 2014
Priority date	Aug 27, 2013
Publication date	Jul 14, 2016
Grant date	—

Abstract

An in-vehicle radiant heater control apparatus includes: a temperature detection device for a heater in a vehicle compartment; a first switch element connected in series to the radiant heater between a power supply and a ground; a temperature control device controlling the first switch element that the heater temperature approaches a target temperature; a resistive element having one electrode connected to one electrode of the heater; an inter-electrode voltage detection device for the resistive element; and a resistance calculation device repeatedly obtaining a heater resistance of the radiant heater based on a voltage between the other electrode of the resistive element and the other electrode of the heater, a detected resistance voltage, and a resistance of the resistive element. The temperature detection device obtains the heater temperature based on the heater resistance.

First claim

What is claimed is:

1 . An in-vehicle radiant heater control apparatus comprising:
a temperature detection device that repeatedly obtains heater temperature of a radiant heater for radiating radiant heat to an occupant in a compartment of a vehicle; a first switch element that is disposed between a power supply and a ground, and is connected in series to the radiant heater; a temperature control device that controls the first switch element based on the heater temperature detected by the temperature detection device every time the temperature detection device obtains the heater temperature of the radiant heater, and controls an electric power to be supplied from the power supply to the radiant heater via the first switch element in such a way that the heater temperature of the radiant heater approaches a target temperature; a resistive element that has a first electrode and a second electrode, one of which is connected to one of two electrodes of the radiant heater; an inter-electrode voltage detection device that detects a resistance voltage between the first electrode and the second electrode of the resistive element; and a resistance value calculation device that repeatedly obtains a heater resistance value of the radiant heater based on a voltage between the other of the first electrode and the second electrode of the resistive element and the other of the two electrodes of the radiant heater, the resistance voltage detected by the inter-electrode voltage detection device, and a resistance value of the resistive element, wherein: the temperature detection device obtains the heater temperature of the radiant heater based on the heater resistance value obtained by the resistance value calculation device.

2 . The in-vehicle radiant heater control apparatus according to claim 1 , further comprising:
a constant-voltage circuit that outputs a constant voltage to the radiant heater; a second switch element that is disposed between the constant-voltage circuit and the radiant heater; a first switch control device that controls the first switch element that the radiant heater is disconnected from the power supply; and a second switch control device that controls the second switch element that the radiant heater is connected to the constant-voltage circuit, wherein: the resistive element is disposed between the constant-voltage circuit and the radiant heater, and provides a first resistive element; the inter-electrode voltage detection device detects the resistance voltage between the first electrode and the second electrode of the first resistive element in a state where the first switch control device controls the first switch element to disconnect between the radiant heater and the power supply, and the second switch control device controls the second switch element to connect between the radiant heater and the constant-voltage circuit; and the resistance value calculation device obtains the heater resistance value of the radiant heater based on the resistance voltage detected by the inter-electrode voltage detection device, a first resistance value of the first resistive element, and an output constant voltage of the constant-voltage circuit.

3 . The in-vehicle radiant heater control apparatus according to claim 2 , wherein:
a current path, through which current flows from the power supply to the radiant heater via the first switch element, is arranged independently from a current path, through which current flows from the constant-voltage circuit to the radiant heater via the first resistive element.

4 . The in-vehicle radiant heater control apparatus according to claim 2 , further comprising:
a circuit output voltage detection device that detects the output constant voltage, which is output from the constant-voltage circuit to the first resistive element and the corresponding radiant heater, wherein: the resistance value calculation device obtains the heater resistance value of the radiant heater based on the output constant voltage detected by the circuit output voltage detection device, the resistance voltage detected by the inter-electrode voltage detection device, and the first resistance value of the first resistive element.

5 . The in-vehicle radiant heater control apparatus according to claim 2 , wherein:
the first resistance value of the first resistive element and the output constant voltage of the constant-voltage circuit are controlled in such a way that an amount of temperature increase of the radiant heater due to an electrical power supplied from the constant-voltage circuit to the radiant heater is set to be an amount of temperature increase not to be sensed with a skin on a palm of the occupant in a state where the first switch control device controls the first switch element to disconnect between the radiant heater and the power supply, and the second switch control device controls the second switch element to connect between the radiant heater and the constant-voltage circuit.

6 . The in-vehicle radiant heater control apparatus according to claim 5 , wherein:
the amount of temperature increase of the radiant heater due to the electrical power supplied from the constant-voltage circuit to the radiant heater is equal to or less than 0.1° C.

7 . The in-vehicle radiant heater control apparatus according to claim 1 , further comprising:
a characteristics calculation device that obtains a resistance-temperature characteristic indicative of a relationship for specifying a one-on-one correspondence between the heater temperature of the radiant heater and the heater resistance value of the radiant heater actually mounted in the vehicle, wherein: the temperature detection device obtains the heater temperature of the radiant heater, which is specified by the one-on-one correspondence with respect to the resistance value of the radiant heater obtained by the resistance value calculation device, based on the resistance-temperature characteristic.

8 . The in-vehicle radiant heater control apparatus according to claim 7 , further comprising:
a vehicle compartment air-temperature detection device that detects an air temperature in the compartment of the vehicle; a temperature determination device that determines whether the heater temperature of the radiant heater is equal to the air temperature in the compartment of the vehicle; a calculation device that calculates the heater resistance value of the radiant heater based on the resistance voltage between the first electrode and the second electrode of the first resistive element detected by the inter-electrode voltage detection device, the resistance value of the resistive element, and the output constant voltage of the constant-voltage circuit, when the temperature determination device determines that the heater temperature of the radiant heater is equal to the air temperature in the compartment of the vehicle; and a storage device that stores a theoretical resistance-temperature characteristic indicative of a relationship for specifying a one-on-one correspondence between the heater temperature of the radiant heater and a theoretical heater resistance value of the radiant heater, wherein: when the temperature determination device determines that the heater temperature of the radiant heater is equal to the air temperature in the compartment of the vehicle, the characteristics calculation device: obtains the theoretical heater resistance value of the radiant heater, which is specified by the one-on-one correspondence with respect to a detected air temperature in the compartment detected by the vehicle compartment air-temperature detection device, based on the theoretical resistance-temperature characteristic; obtains a difference between an obtained theoretical heat

Assignees

• Denso Corp

Inventors

• Nakashima Masatoshi
• Kataoka Takuya
• Ishikawa Kimitake
• Sagou Yasuhiro
• Takahashi Asami
• Sakane Hiroyuki
• Oga Akira

Classifications

• B60H2001/2256

  related to the operation of the heater itself, e.g. flame detection or overheating · CPC title

• H05B1/0236 Primary

  for vehicles · CPC title

• B60H1/2226

  Electric heaters using radiation · CPC title

• H05B2203/032

  Heaters specially adapted for heating by radiation heating · CPC title

• B60H2001/224

  automatic operation, e.g. control circuits or methods · CPC title