Vehicle air conditioning control system

Abstract

To provide a vehicle air-conditioning control system that can operate an electric heater such as a PCT heater to perform heating of a vehicle interior space, without increasing the size and cost of a DC / DC converter.SOLUTION: A vehicle air-conditioning control system 1 includes an electric heater 2 that can heat an air-conditioning wind, a DC / DC converter 3 for converting the voltage of an electric power of an on-vehicle battery to a predetermined voltage, an engine system temperature sensor 15 for measuring the temperature T12 of an engine 10 or a member 12 relating to the engine, and a control unit 4 for controlling the operation state of the electric heater 2 on the basis of the temperature T12. The control unit 4, when determining based on the temperature T12 that operation of the electric heater 2 is required, performs control for changing an operation state between an operation state of turning on the electric heater 2 and causing the DC / DC converter 3 to output a short-time current and an operation state of turning off the electric heater 2 and causing the DC / DC converter 3 to output a steady-state current.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a vehicle air conditioning control system. [Background technology]

[0002] In hybrid vehicles that run on both an engine and a motor, when heating the interior of the vehicle, the heat from the engine cannot be used, for example, when the engine is started or when the vehicle is running on the motor and the engine is stopped. Therefore, in such cases, a technique is known in which a PTC (Positive Temperature Coefficient) heater is used as a heat source for heating (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-58742 Summary of the Invention [Problem to be solved by the invention]

[0004] In hybrid vehicles and the like, the DC voltage of a high-voltage battery is converted to a lower DC voltage by a DC / DC converter and supplied to various electrical loads such as ECUs (Electric Control Units) and air conditioning equipment (air conditioners). However, because PTC heaters consume a lot of power, a large current must be supplied from the DC / DC converter, which increases the size and cost of the DC / DC converter.

[0005] The present invention has been made in consideration of the above points, and an object of the present invention is to provide a vehicle air conditioning control system that can heat the vehicle interior space by operating an electric heater such as a PTC heater without increasing the size or cost of the DC / DC converter. [Means for solving the problem]

[0006] In order to solve the above problem, one embodiment of the present invention is a vehicle air conditioning control system, an electric heater capable of heating the air conditioning air blown into the vehicle interior; a DC / DC converter that converts the voltage of the vehicle's battery into a predetermined voltage; an engine temperature sensor that measures the temperature of the engine or a component related to the engine; a control unit that controls an operating state of the electric heater based on the temperature measured by the engine temperature sensor; Equipped with the DC / DC converter is capable of switching the output current between a steady-state current and a short-time current which has a higher current value than the steady-state current but can only be output for a predetermined time; When the control unit determines that operation of the electric heater is necessary based on the temperature, it controls the operation state to be switched between an operation state in which the electric heater is turned on and the short-term current is output from the DC / DC converter, and an operation state in which the electric heater is turned off and the steady-state current is output from the DC / DC converter. [Effects of the Invention]

[0007] According to the present invention, it is possible to heat the vehicle interior space by operating an electric heater without increasing the size or cost of the DC / DC converter. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic diagram showing the configuration of a vehicle air-conditioning control system according to first to fifth embodiments. [Figure 2] 5 is a timing chart illustrating how the control unit controls the operating state of the electric heater. [Figure 3] 6 is a timing chart illustrating a control method and the like in the second embodiment. [Figure 4] 10 is a timing chart illustrating a control method and the like in the third embodiment. [Figure 5] 10 is a timing chart illustrating a control method and the like in the fourth embodiment. [Figure 6] 10A is a timing chart illustrating a control method and the like in the fourth embodiment, and FIG. 10B is a timing chart illustrating a control method and the like in the fifth embodiment. [Figure 7] FIG. 10 is a schematic diagram showing the configuration of a vehicle air-conditioning control system according to a sixth embodiment. [Figure 8] 10 is a timing chart illustrating how the temperature of the engine coolant rises more rapidly in the sixth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a vehicle air conditioning control system according to the present invention will now be described with reference to the drawings. The vehicle air conditioning control system according to the present invention is a system to be installed in a hybrid vehicle, etc. When an occupant starts heating while the engine temperature is low, such as when starting the engine, the system uses an electric heater to supplement heating provided by the vehicle's existing air conditioning equipment and raise the temperature of the conditioned air.

[0010] In the following, we will mainly explain what happens when the engine starts, but the same explanation applies when the vehicle is running on the motor and the engine is stopped, or when the engine is started in that state (when the vehicle switches from running on the motor to running on the engine). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A vehicle air conditioning control system according to the present invention will be described below with reference to several embodiments.

[0011] [First embodiment] In this embodiment, the principle of control of the vehicle air-conditioning control system according to the present invention will be described. Fig. 1 is a schematic diagram showing the configuration of the vehicle air-conditioning control system according to this embodiment. The vehicle air conditioning control system 1 includes an electric heater 2, a DC / DC converter 3, and a control unit 4.

[0012] A PTC heater can be used as the electric heater 2. However, the electric heater 2 may be a heater of another type. The electric heater 2 is disposed near a fan or in an air duct of an air conditioning system (not shown) that heats the air taken in by using the exhaust heat of the engine 10 and sends it to the vehicle interior (not shown) to heat the vehicle interior. The electric heater 2 can heat the conditioned air blown out from the air conditioning system into the vehicle interior.

[0013] The DC / DC converter 3 converts the DC voltage (for example, 24 [V] or 36 [V]) of a high-voltage battery (not shown) mounted on the vehicle into a lower predetermined DC voltage (for example, 12 [V]). The converted predetermined DC voltage is then supplied to the electric heater 2 and other electric loads 5 such as various ECUs and air conditioning equipment.

[0014] The DC / DC converter 3 constantly notifies the control unit 4 of the current value it is outputting. In addition, the DC / DC converter 3 is capable of switching the output direct current between a steady-state current (a current equal to or less than the rated current) and a short-time current (a current equal to or less than the rated short-time current) that is greater than the steady-state current but can only be output for a predetermined time Δt1.

[0015] The DC / DC converter 3 is provided with a flow path 33 for cooling water 32 as a converter cooling system 31 for cooling the DC / DC converter 3 . In order to distinguish it from the cooling water 12 of the engine 10 described later, the cooling water 32 of the DC / DC converter 3 will be referred to as the converter cooling water 32 , and the cooling water 12 of the engine 10 will be referred to as the engine cooling water 12 .

[0016] The flow path 33 is provided with a pump 34 for circulating the converter cooling water 32 within the flow path 33 . In addition, the flow path 33 is provided with a temperature T 32 A converter system temperature sensor 35 is provided to measure the temperature, which will be explained later.

[0017] The engine 10 is provided with a flow path 13 for engine cooling water 12 as an engine cooling system 11 for cooling the engine 10 . The flow path 13 includes a pump 14 for circulating the engine cooling water 12 in the flow path 13, and a temperature T 12 and an engine system temperature sensor 15 for measuring the temperature.

[0018] In this manner, in this embodiment, the engine system temperature sensor 15 detects the temperature T 12 The engine temperature sensor 15 is configured to measure the temperature of the engine 10 itself, and the engine coolant 12 corresponds to a member related to the engine. In addition, the engine temperature sensor 15 can also be configured to measure the temperature of an engine room (not shown) or the like. The engine temperature sensor 15 measures the temperature T of the engine coolant 12. 12 is transmitted to the control unit 4.

[0019] The control unit 4 can be configured as an ECU. In this case, the control unit 4 may be configured as a single ECU, or may be constructed within an ECU for a power supply system including the DC / DC converter 3, or within an ECU for an air conditioning system.

[0020] The control unit 4 then calculates the temperature T of the engine coolant 12 measured by the engine temperature sensor 15. 12 The operating state of the electric heater 2 is controlled based on the above. That is, the temperature T of the engine cooling water 12 12is the given temperature T 12 If the temperature is above th and the vehicle is sufficiently warm, the engine 10 is also sufficiently warm, so the vehicle's existing air conditioning equipment can provide sufficient heating without operating the vehicle air conditioning control system 1 according to this embodiment.

[0021] Therefore, the control unit 4 detects the temperature T of the engine coolant 12 measured by the engine temperature sensor 15. 12 is the given temperature T 12 If the temperature is equal to or higher than th, it is determined that the operation of the electric heater 2 is not necessary. After starting to control the operating state of the electric heater 2, which will be described below, the control unit 4 also detects the temperature T 12 is the given temperature T 12 th, the control is also stopped at that point. This is because the vehicle's existing air conditioning equipment can provide sufficient heating, so there is no need to operate the electric heater 2 to assist with heating.

[0022] On the other hand, the control unit 4 detects the temperature T of the engine coolant 12 measured by the engine temperature sensor 15. 12 is the given temperature T 12 If the temperature is less than th, it is determined that the electric heater 2 needs to be operated. When the control unit 4 determines that the electric heater 2 needs to be operated, it controls the electric heater 2 to switch the operating states of the electric heater 2 and the DC / DC converter 3. That is, the control unit 4 controls the switching of the operating state between an operating state in which the electric heater 2 is turned on and a short-term current is output from the DC / DC converter 3, and an operating state in which the electric heater 2 is turned off and a steady-state current is output from the DC / DC converter 3.

[0023] The method of controlling the operating state of the electric heater 2 by the control unit 4 will now be described in detail. 2, it is assumed that the engine 10 is started at time t1 (engine ON), and an operation to start heating is performed by a passenger at time t2 (heating ON). Note that there may be cases where an operation to start heating is performed before the engine 10 is started.

[0024] The control unit 4 detects the temperature T of the engine coolant 12 measured by the engine system temperature sensor 15 at the time when the operation to start heating is performed (time t2). 12 is the given temperature T 12 It is judged whether the value is equal to or greater than th. 12 in represents the initial temperature of the engine coolant 12. In this case, the temperature T 12 is the given temperature T 12 Since the temperature is less than th, the control unit 4 determines that the electric heater 2 needs to be operated.

[0025] Then, the control unit 4 requests the DC / DC converter 3 to transmit information on the time during which a short-term current can be output, i.e., the above-mentioned predetermined time Δt1, and the time Δt2 during which a steady-state current must be output after the short-term current has been output. The DC / DC converter 3 notifies the control unit 4 of the times Δt1 and Δt2. The control unit 4 may have information on the times Δt1, Δt2, etc. in advance. In this case, processing such as a transmission request and notification from the DC / DC converter 3 becomes unnecessary.

[0026] Then, the control unit 4 repeatedly sends to the electric heater 2 a signal (hereinafter referred to as an on signal) that turns on the electric heater 2 for a time Δta and a signal (hereinafter referred to as an off signal) that turns off the electric heater 2 for a time Δtb. The time Δta for turning on the electric heater 2 may be the same as the predetermined time Δt1, or may be set to be shorter than Δt1. The time Δtb for turning off the electric heater 2 may be the same as the predetermined time Δt2, or may be set to be longer than Δt2.

[0027] When an ON signal is sent from the control unit 4, the electric heater 2 is activated and switches to an operating state in which it generates heat. When the electric heater 2 is turned on, the DC / DC converter 3 changes from an operating state in which it outputs a steady current to an operating state in which the current value increases by the amount of the current consumed when the electric heater 2 is on, and the operating state outputs a current that exceeds the rated current for a short period of time.

[0028] When an OFF signal is sent from the control unit 4, the electric heater 2 is switched to an operating state in which activation is stopped. Then, the operating state of the DC / DC converter 3 switches from a state in which it outputs a short-time current to a state in which it outputs a steady-state current.

[0029] Note that Figure 2 and Figure 3 described later show a case where the current value output from the DC / DC converter 3 to other electrical loads 5 (see Figure 1) including air conditioning equipment is 120 [A], and the current value consumed by the electric heater 2 is 60 [A] (total 180 [A]). In this case, the rated current and rated short-time current of the DC / DC converter 3 are, for example, 120 [A] and 190 [A], respectively.

[0030] In this way, the control unit 4 controls the electric heater 2 to switch the operating states of the electric heater 2 and the DC / DC converter 3. The control unit 4 then calculates the temperature T of the engine cooling water 12 measured by the engine system temperature sensor 15. 12 is the given temperature T 12 When th is reached (time t3), the above control is stopped.

[0031] With this configuration, when the electric heater 2 is turned on, the DC current output from the DC / DC converter 3 becomes a short-time current, and even if the current value of the DC current becomes a current value greater than the rated current, the electric heater 2 is turned off after the time Δta has elapsed. Then, the direct current output from the DC / DC converter 3 becomes a steady current equal to or less than the rated current, and this state continues for Δtb, during which the DC / DC converter 3 is sufficiently cooled.

[0032] Therefore, according to the vehicle air conditioning control system 1 of this embodiment, there is no need to increase the size of the converter cooling system 31 for cooling the DC / DC converter 3, such as the flow path 33 of the DC / DC converter 3 and the pump 34, and existing cooling equipment can be used. Therefore, according to the vehicle air conditioning control system 1 of the present invention, it is possible to heat the vehicle interior space (heating to supplement the heating equipment) by operating an electric heater 2 such as a PTC heater without increasing the size or cost of the DC / DC converter 3.

[0033] Furthermore, even if the electric heater 2 is turned on, if the current value of the direct current output from the DC / DC converter 3 is equal to or less than the rated current, the DC / DC converter 3 is sufficiently cooled by the converter cooling water 32 even if the electric heater 2 is not turned off. Therefore, in such a case, it is possible to configure the electric heater 2 to remain on without controlling the on / off switching of the electric heater 2 as described above.

[0034] Furthermore, when the electric heater 2 is switched on and off as described above, the temperature of the conditioned air (heated air) blown into the vehicle interior space fluctuates, which may be uncomfortable for the occupants. Therefore, by configuring the electric heater 2 to be switched on and off repeatedly at short time intervals, it is possible to prevent the passengers from noticing the temperature fluctuations of the conditioned air.

[0035] [Second embodiment] Next, the temperature T of the converter cooling water 32 with respect to the cooling efficiency of the DC / DC converter 3 32 An embodiment of a vehicle air-conditioning control system 1 that takes into consideration the influence of the above will be described. Converter cooling water temperature T32 When Δta is sufficiently low, the efficiency of cooling the DC / DC converter 3 by the converter cooling water 32 is high after the DC / DC converter 3 outputs a current for a short time and then switches to an operating state in which it outputs a steady current. Therefore, even if the time during which the DC / DC converter 3 outputs a current for a short time, i.e., the time Δta during which the electric heater 2 is turned on, is extended, the DC / DC converter 3 is thereafter sufficiently cooled.

[0036] However, the temperature T of the converter cooling water 32 32 When the temperature rises, the cooling efficiency of the DC / DC converter 3 by the converter cooling water 32 decreases after switching to an operating state in which a steady current is output after a short-time current is output. Therefore, the temperature T 32 If is high, the temperature T 32 In this case, it is necessary to shorten the predetermined time during which current is output from the DC / DC converter 3 for a short time, that is, the time Δta during which the electric heater 2 is turned on, compared to when the temperature is low.

[0037] Therefore, the control unit 4 determines the time Δta for turning on the electric heater 2 based on the temperature T 32 It is possible to configure the temperature to change depending on the temperature. For example, when the electric heater 2 is repeatedly switched on and off as described above and a current is repeatedly output from the DC / DC converter 3 for a short time, the temperature T 32 rises.

[0038] Therefore, as shown in FIG. 3, for example, the temperature T 32 When the temperature is low, the time Δta for turning on the electric heater 2 is lengthened. The temperature T of the converter cooling water 32 32 rises to a predetermined temperature T 32 When the temperature reaches th, the time Δta for turning on the electric heater 2 can be shortened.

[0039] With this configuration, at least the temperature T 32 When the temperature is low, the time Δta for turning on the electric heater 2 becomes longer, and the conditioned air blown into the vehicle interior from the air conditioning equipment can be heated by the electric heater 2 for a longer period of time. Therefore, even when the temperature of the engine 10 is low and the temperature of the conditioned air blown into the vehicle interior is low, the electric heater 2 can heat the conditioned air.

[0040] In addition, in Figure 3, the converter cooling water temperature T 32 is shown to rise linearly, but in reality it repeats small rises and falls in response to the on / off of the electric heater 2. This is the same as in Figure 4, which will be described later. Alternatively, instead of varying the time Δta for turning on the electric heater 2, the time Δtb for turning off the electric heater 2 (i.e., the time for outputting a steady current after outputting a short-term current) may be varied. In this case, the temperature T 32 The control is configured so that the time Δtb for turning off the electric heater 2 is lengthened as the temperature rises.

[0041] [Third embodiment] On the other hand, as the electric heater 2, it is also possible to use an electric heater configured so that the heating intensity can be switched between, for example, strong, medium, and weak. The control unit 4 can be configured to switch the heating intensity of the electric heater 2 in addition to switching the electric heater 2 on and off as described above.

[0042] In this case, when the heating intensity by the electric heater 2 is weak, the current value consumed by the electric heater 2 is small, but as the heating intensity increases from medium to strong, the current value consumed by the electric heater 2 may increase. As described above, the temperature T 32 The lower the temperature, the higher the cooling efficiency of the DC / DC converter 3 by the converter cooling water 32.

[0043] Therefore, the control unit 4 calculates the temperature T of the converter cooling water 32 measured by the converter system temperature sensor 35 as shown in FIG. 32 If the temperature is low, the heating intensity when the electric heater 2 is turned on is increased. The temperature T of the converter cooling water 32 32 rises to a predetermined temperature T 32 At the point in time th1 (time t4), the heating intensity when the electric heater 2 is on is changed from strong to medium.

[0044] The temperature T of the converter cooling water 32 32 rises further to a predetermined temperature T 32 At the point in time th2 (time t5), the heating intensity when the electric heater 2 is on is changed from medium to weak. In this way, it is possible to configure the electric heater so that it can be switched on and off while changing the heating intensity.

[0045] With this configuration, at least the temperature T 32 When the temperature is low, the heating intensity of the electric heater 2 increases, and the conditioned air blown into the vehicle interior from the air conditioning equipment can be heated to a higher temperature by the electric heater 2. Therefore, even when the temperature of the engine 10 is low and the temperature of the conditioned air blown into the vehicle interior is low, the electric heater 2 can efficiently heat the conditioned air.

[0046] In addition, Figure 4 and Figure 5 described later show cases where the current values ​​consumed when the heating intensity of the electric heater 2 is strong, medium, and weak are 60 [A], 40 [A], and 20 [A], respectively. In addition, although the case where the heating intensity of the electric heater 2 is switched in the order of strong, medium, and weak has been shown, it is also possible to configure it to be switched in other order, for example, strong and weak, medium and weak, or strong and medium. In the following, a case where the heating intensity or on / off of the electric heater 2 is switched as in this embodiment will be described, but at the same time, it is also possible to configure the device so as to perform control to change the time Δta for turning on the electric heater 2 as described in the second embodiment.

[0047] [Fourth embodiment] In addition, the temperature T 32 When is low, the temperature T 32 When the temperature is high, the rated current of the DC / DC converter 3 may become higher than when the temperature is high. In such a case, the DC / DC converter 3 may be sufficiently cooled by reducing the heating intensity of the electric heater 2 and thereby reducing the current value output from the DC / DC converter 3, without switching the electric heater 2 from on to off.

[0048] Therefore, in such a case, the control unit 4 determines the temperature T 32 Depending on the temperature T of the converter cooling water 32, 32 It is possible to configure the control so that when the temperature is low, the electric heater 2 is not turned off but only the heating intensity is switched. For example, as shown in FIG. 5, the temperature T 32 When the temperature T 32 is the given temperature T 32 During the period from time t2 to time t6, when the temperature is equal to or lower than th3, the heating intensity of the electric heater 2 is switched between high and medium.

[0049] In addition, the temperature T 32 rises and the temperature T 32 is the given temperature T 32 When the temperature T th3 is reached (time t6), the control method is changed so that the heating intensity of the electric heater 2 is switched between high and low. 32 When the temperature is low, the electric heater 2 is not turned off but the heating intensity is changed. The temperature T of the converter cooling water 32 32 rises further and reaches temperature T 32 is the given temperature T 32 When the temperature reaches th4 (time t7), the control method is changed so that the electric heater 2 is switched between ON (heating intensity is medium, for example) and OFF. The heating intensity when ON may be set to low.

[0050] With this configuration, at least the temperature T 32 When the temperature is low, the electric heater 2 can be kept on and generate heat in this embodiment, while the electric heater 2 is turned off in the third embodiment. Therefore, even when the temperature of the engine 10 is low and the temperature of the conditioned air blown into the vehicle interior is low, the electric heater 2 can efficiently heat the conditioned air.

[0051] [Fifth embodiment] In the above-described embodiments, the electric heater 2 is turned on and off and the heating intensity is changed depending on the temperature T 12 is the given temperature T 12 This explains the case where this is done until it reaches th, etc. However, depending on the current value of the direct current output from the DC / DC converter 3, the temperature T 12 is the given temperature T 12 Before reaching th or the like, it may be possible to stop switching the electric heater 2 on and off or stopping the switching of the heating intensity.

[0052] Here, for example, a case where control is performed in the same way as the control of switching on and off of the electric heater 2 or the switching of the heating intensity shown in FIG. 5 will be considered. However, while the current value output from the DC / DC converter 3 to the other electrical load 5 is 120 [A] in Figure 5, let us consider a case where it is 80 [A] here. Note that the current values ​​consumed when the heating intensity of the electric heater 2 is set to strong, medium, and weak are 60 [A], 40 [A], and 20 [A] respectively, and the rated current and rated short-time current of the DC / DC converter 3 are 120 [A] and 190 [A] respectively, as in the above.

[0053] In this case, when control is performed in the same manner as in the case shown in FIG. 5, the heating intensity of the electric heater 2 is switched between high and medium between time t2 and time t6 as shown in FIG. 6(a). In this case, when the heating intensity of the electric heater 2 is high, the current value output from the DC / DC converter 3 to the electric heater 2 is 60 [A], and the current value output to the other electrical load 5 is 80 [A]. Therefore, a short-term current of 140 [A] is output from the DC / DC converter 3.

[0054] Furthermore, when the heating intensity of the electric heater 2 is medium, the current value output from the DC / DC converter 3 to the electric heater 2 is 40 [A], so that the DC / DC converter 3 outputs a steady-state current of 120 [A]. Therefore, a state is created in which the DC / DC converter 3 outputs a current of 140 [A] for a short time and then outputs a steady current of 120 [A].

[0055] Conversely, in this case, if the heating intensity of the electric heater 2 is medium, the direct current output from the DC / DC converter 3 becomes a steady current, so it is sufficient to simply lower the heating intensity of the electric heater 2 to medium. If the DC current output from the DC / DC converter 3 does not become a steady current even when the heating intensity of the electric heater 2 is reduced to medium, the heating intensity of the electric heater 2 must be reduced to low or the electric heater 2 must be turned off.

[0056] Next, as shown in Figure 6(a), if the heating intensity of the electric heater 2 is switched between strong and weak between time t6 and time t7, in this case, the current value output from the DC / DC converter 3 to the electric heater 2 fluctuates between 60 [A] and 20 [A]. Then, let us assume that the average value of the current output from the DC / DC converter 3 to the electric heater 2 during the period from time t6 to time t7 is 40 A. This average value is equal to the current value output from the DC / DC converter 3 to the electric heater 2 when the heating intensity of the electric heater 2 is set to medium.

[0057] In this case, a current of 80 [A] is output from the DC / DC converter 3 to the other electrical loads 5, so that an average current of 120 [A] is ultimately output from the DC / DC converter 3 to the electric heater 2 and the other electrical loads 5. Since this current value is less than the rated current, in this case, a steady-state current of 120 [A] should be output from the DC / DC converter 3.

[0058] Therefore, instead of switching the heating intensity of the electric heater 2 between high and low between time t6 and time t7 as shown in FIG. 6(a), the same heating effect can be obtained by setting the heating intensity of the electric heater 2 to medium during that time as shown in FIG. 6(b). Moreover, in this case, it is sufficient to output a steady current of 120 [A] from the DC / DC converter 3, and it becomes unnecessary for the DC / DC converter 3 to output a current for a short period of time.

[0059] In this way, in the above case, the control unit 4 switches the heating intensity of the electric heater 2 between high and medium from time t2 to time t6, but can stop switching the heating intensity of the electric heater 2 after time t6. That is, at time t3, the temperature T 12 is the given temperature T 12 It is possible to stop switching the heating intensity of the electric heater 2 before the temperature reaches th.

[0060] In addition, Figure 6(b) shows a case where, for the same reason as above, from time t7 to time t3, instead of controlling the electric heater 2 to switch on and off as shown in Figure 6(a), the heating intensity of the electric heater 2 is kept low.

[0061] [Sixth embodiment] As mentioned above, the above control by the vehicle air conditioning control system 1 is intended to assist heating using the electric heater 2 when the temperature of the engine 10 is low and the temperature of the conditioned air blown out from the vehicle's existing air conditioning equipment is low. When the DC / DC converter 3 operates, it generates heat, and the exhaust heat is absorbed by the converter cooling water 32, and the temperature T 32 will rise.

[0062] If the engine 10 can be warmed using the exhaust heat from the DC / DC converter 3, it will be possible to quickly increase the temperature of the conditioned air blown out from the air conditioning equipment. Therefore, it is possible to configure the engine cooling system 11 for cooling the engine 10 and the converter cooling system 31 for cooling the DC / DC converter 3 as the same cooling system.

[0063] That is, it is possible to configure the engine 10 and the DC / DC converter 3 so that they are cooled by a single cooling system. Figure 7 is a diagram showing the configuration of a vehicle air conditioning control system 1 configured in this way. In this embodiment, the components constituting the vehicle air-conditioning control system 1 are the same as those shown in Fig. 1 and therefore will not be described again, but the engine cooling system 11 also functions as the converter cooling system 31. The engine temperature sensor 15 also functions as the converter temperature sensor 35.

[0064] With this configuration, the exhaust heat from the DC / DC converter 3 is absorbed by the engine coolant 12. Therefore, as shown by the solid line in FIG. 8, the temperature T 12 will rise more rapidly.

[0065] Therefore, the engine 10 and the like are rapidly heated by the temperature rise of the engine coolant 12, and the temperature of the conditioned air blown into the vehicle interior space from the air conditioning equipment also rises rapidly. In addition, the temperature T of the engine coolant 12 12 The temperature reaches the specified temperature T 12 th, it becomes possible to complete the control in the vehicle air-conditioning control system 1 in a shorter time than when the cooling systems for the engine 10 and the DC / DC converter 3 are formed separately.

[0066] It goes without saying that the present invention is not limited to the above-described embodiments, and can be modified as appropriate without departing from the spirit of the present invention. For example, in each of the above embodiments, the engine system temperature sensor 15 detects the temperature T 12 However, any device capable of measuring the temperature of the engine 10 and associated components may be used. The converter system temperature sensor 35 may be any sensor that measures the temperature of a component related to the cooling of the DC / DC converter 3, and may measure the temperature T 32 This is not limited to measuring [Explanation of symbols]

[0067] 1. Vehicle air conditioning control system 2 Electric heater 3 DC / DC converters 4. Control Unit 10 Engine 11 Engine cooling system 12 Engine coolant (engine-related parts) 15 Engine temperature sensor 31 Converter cooling system 32 Converter cooling water (components related to cooling of DC / DC converters) 35 Converter temperature sensor T 12 temperature T 12 th specified temperature T 32 temperature Δt1 given time

Claims

1. an electric heater capable of heating the air conditioning air blown into the vehicle interior; a DC / DC converter that converts the voltage of the power of the vehicle battery into a predetermined voltage; an engine temperature sensor that measures the temperature of the engine or a component related to the engine; a control unit that controls an operating state of the electric heater based on the temperature measured by the engine temperature sensor; Equipped with the DC / DC converter is capable of switching the output current between a steady-state current and a short-time current which has a higher current value than the steady-state current but can only be output for a predetermined time; When the control unit determines that operation of the electric heater is necessary based on the temperature, the control unit controls the electric heater to switch between an operating state in which the electric heater is turned on and the DC / DC converter outputs the short-term current, and an operating state in which the electric heater is turned off and the DC / DC converter outputs the steady-state current.

2. 2. The vehicle air conditioning control system according to claim 1, wherein, when the control unit starts controlling the operating state, the control unit stops the control when the temperature measured by the engine temperature sensor reaches a predetermined temperature.

3. a converter system temperature sensor for measuring the temperature of a member related to cooling of the DC / DC converter; 2. The vehicle air conditioning control system according to claim 1, wherein the control unit changes the time for which the electric heater is turned on depending on the temperature measured by the converter system temperature sensor.

4. 2. The vehicle air conditioning control system according to claim 1, wherein the control unit does not control the on / off switching of the electric heater when the value of the current output from the DC / DC converter is equal to or less than a rated current even if the electric heater is turned on.

5. The electric heater is configured to be able to switch the heating intensity, 2. The vehicle air conditioning control system according to claim 1, wherein the control unit switches the electric heater on and off and switches the heating intensity.

6. a converter system temperature sensor for measuring the temperature of a member related to cooling of the DC / DC converter; 6. The vehicle air conditioning control system according to claim 5, wherein the control unit switches the electric heater on and off while changing the heating intensity so as to weaken the heating intensity when the electric heater is on as the temperature measured by the converter system temperature sensor increases.

7. A converter system temperature sensor is provided to measure the temperature of a component related to cooling of the DC / DC converter, 6. The vehicle air conditioning control system according to claim 5, wherein the control unit controls the electric heater so as to only switch the heating intensity without turning off the electric heater according to the temperature measured by the converter system temperature sensor.

8. 8. The vehicle air conditioning control system according to claim 1, wherein an engine cooling system for cooling the engine and a converter cooling system for cooling the DC / DC converter are configured as a same cooling system.

9. 9. The vehicle air conditioning control system according to claim 8, wherein the engine temperature sensor also serves as a converter temperature sensor for measuring the temperature of a member related to cooling of the DC / DC converter.

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