JP6576613B2 - Air conditioner for vehicles - Google Patents

Description

  The present invention relates to a vehicle air conditioner, and more particularly to a vehicle air conditioner that takes at least two air conditioning operation states of a cooling operation state and a heating operation state.

As a conventional vehicle air conditioner, Patent Document 1 discloses a compressor that compresses and discharges a refrigerant, an outdoor heat exchanger that performs heat exchange between the refrigerant and outdoor air, and a fan that blows air into the vehicle interior. What has an indoor heat exchanger which performs heat exchange between the ventilation air to be performed is proposed.
In this conventional vehicle air conditioner, the refrigerant absorbed in the indoor heat exchanger is dissipated in the outdoor heat exchanger, and the refrigerant circuit operating in the cooling mode for cooling the blown air is absorbed in the outdoor heat exchanger. The refrigerant circuit operates in a heating mode in which the refrigerant is radiated by the indoor heat exchanger to heat the blown air, and refrigerant circuit switching means including a switching valve that switches the mode of the refrigerant circuit.

In such a vehicle air conditioner, when the refrigerant circuit is switched between the cooling mode and the heating mode, the pressure of the refrigerant passing through the switching valve that constitutes the refrigerant circuit switching means changes. Sound and vibration were generated, which could cause discomfort to the passengers.
For this reason, in the conventional vehicle air conditioner proposed in Patent Document 1, the refrigerant circuit switching means includes a reference high-pressure refrigerant whose discharge-side high-pressure refrigerant pressure is predetermined after the compressor is stopped. The refrigerant circuit switching means switches the refrigerant circuit on condition that the pressure becomes lower than the pressure. As a result, the conventional vehicle air conditioner switches the refrigerant circuit without causing discomfort to the passengers by reducing abnormal noise and vibration due to switching of the refrigerant circuit switching means.

  The refrigerant circuit switching means switches the refrigerant circuit when a predetermined reference stop time has elapsed since the compressor stopped even if the high-pressure side refrigerant pressure is higher than the reference high-pressure side refrigerant pressure. ing. As a result, when it takes time for the high-pressure side refrigerant pressure to drop to the reference high-pressure side refrigerant pressure, the conventional vehicle air conditioner has priority over reducing the operating noise of the refrigerant circuit switching means. The deterioration of the responsiveness of the air conditioning function to the operation was suppressed.

JP 2011-5981 A

  However, what is proposed in Patent Document 1 performs uniform control when switching from the cooling mode to the heating mode and when switching from the heating mode to the cooling mode. There has been a problem that the deterioration of the responsiveness cannot be sufficiently suppressed.

  Therefore, the present invention has been made to solve such a problem, and provides a vehicle air conditioner that can improve the responsiveness of an air conditioning function to an occupant's operation as compared with a conventional one. For the purpose.

A first aspect of the present invention includes a compressor that compresses a refrigerant, and a switching valve that switches a flow path of the refrigerant compressed by the compressor between a plurality of flow paths including at least a cooling flow path and a heating flow path, When the refrigerant flow path is switched from the cooling flow path to the heating flow path by the switching valve, the compressor is stopped and the first predetermined condition is satisfied. When the switching valve is controlled to switch the refrigerant flow path and the refrigerant flow path is switched from the heating flow path to the cooling flow path by the switching valve, the compressor is stopped and set loosely beforehand from the first condition. A switching control unit that controls the switching valve so that the switching to the cooling channel is faster than the switching to the heating channel by switching the refrigerant channel when the second condition is satisfied. Octopus The one in which the features.

  As a second aspect of the present invention, the apparatus further includes a refrigerant pressure sensor that detects a pressure of the refrigerant compressed by the compressor, and the switching control unit determines that the pressure detected by the refrigerant pressure sensor is less than a predetermined first pressure. It is determined that the first condition is satisfied when the second pressure is reached, and it is determined that the second condition is satisfied when the pressure detected by the refrigerant pressure sensor is lower than the second pressure set higher than the first pressure in advance. You may do it.

  As a third aspect of the present invention, a timer for measuring an elapsed time from when the compressor is stopped is further provided, and the switching control unit has a first condition when the elapsed time exceeds a predetermined first time. It may be determined that the second condition is satisfied, and it may be determined that the second condition is satisfied when the elapsed time exceeds a predetermined second time shorter than the first time.

  As a fourth aspect of the present invention, a first air-conditioning mode that blows air-conditioned air toward at least the driver's seat and front passenger seat of the vehicle, and air-conditioning air blows out toward the feet of passengers seated in the driver's seat and front passenger seat. An air conditioning mode selection unit that selects one air conditioning mode from a plurality of air conditioning modes including the second air conditioning mode, and the switching control unit is configured to select the first air conditioning mode by the air conditioning mode selection unit. The second condition may be relaxed compared to when the second air conditioning mode is selected.

  As described above, the first aspect described above has the refrigerant flow path for heating so that the switching to the cooling operation state at the request of the vehicle occupant, which requires a quicker response than the switching to the heating operation state, is made faster. When switching from the flow path to the cooling flow path, the conditions for switching the refrigerant flow path are relaxed compared to switching from the cooling flow path to the heating flow path. For this reason, said 1st aspect can improve the responsiveness of the air-conditioning function with respect to a passenger | crew's operation compared with the conventional one.

  In the second aspect, the refrigerant flow path is switched from the heating flow path to the cooling flow path so that the switching to the cooling operation state, which requires a quicker response than the switching to the heating operation state, is made faster. In this case, the refrigerant pressure is increased as a condition for switching the refrigerant flow path as compared with the case of switching from the cooling flow path to the heating flow path. For this reason, said 2nd aspect can improve the responsiveness of the air-conditioning function with respect to a passenger | crew's operation compared with the conventional one.

  In the third aspect, the refrigerant flow path is switched from the heating flow path to the cooling flow path so as to speed up the switching to the cooling operation state, which requires a quicker response than the switching to the heating operation state. In this case, the elapsed time as a condition for switching the refrigerant flow path is shortened as compared with the case of switching from the cooling flow path to the heating flow path. For this reason, said 3rd aspect can improve the responsiveness of the air-conditioning function with respect to a passenger | crew's operation compared with the conventional one.

  Said 4th aspect makes loose the conditions which switch the flow path of a refrigerant | coolant, when the 1st air conditioning mode from which the quicker response is calculated | required than the 2nd air conditioning mode is selected. For this reason, said 4th aspect can improve the responsiveness of the air-conditioning function with respect to a passenger | crew's operation compared with the conventional one.

FIG. 1 is a configuration diagram showing a main part of a vehicle equipped with a vehicle air conditioner according to an embodiment of the present invention. FIG. 2 is a configuration diagram showing a main part of the vehicle shown in FIG. 1 when the air conditioning operation state is in the cooling operation state. FIG. 3 is a configuration diagram showing a main part of the vehicle shown in FIG. 1 when the air conditioning operation state is in the heating operation state. FIG. 4 is a conceptual diagram showing a map referred to by the vehicle air conditioner according to the embodiment of the present invention. FIG. 5 is a flowchart showing an initialization operation included in the air conditioning operation state switching operation by the vehicle air conditioner according to the embodiment of the present invention. FIG. 6 is a flowchart showing a switching execution operation included in the air conditioning operation state switching operation by the vehicle air conditioner according to the embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
As shown in FIG. 1, the vehicle 1 includes a vehicle air conditioner 2. The vehicle air conditioner 2 includes an air conditioning unit 3 and an ECU (Electronic Control Unit) 4.
In the present embodiment, the air conditioning unit 3 has at least two air conditioning operation states, a cooling operation state in which the vehicle interior is cooled as shown in FIG. 2 and a heating operation state in which the vehicle interior is heated as shown in FIG. It has come to take.

In FIG. 1, the air conditioning unit 3 has an outside air introduction port 10 a that communicates the inside of the air conditioning unit 3 with the outside of the vehicle interior, and an inside air introduction that communicates the inside of the air conditioning unit 3 with the interior of the vehicle interior. A mouth 10b is formed.
The outside air introduction port 10 a is an introduction port for introducing air outside the passenger compartment into the air conditioning unit 3. The inside air introduction port 10b is an introduction port for introducing the air in the vehicle interior into the air conditioning unit 3, that is, the introduction port for introducing the air circulating in the vehicle interior.

  In the air conditioning unit 3, there is provided an introduction port switching door 11 for switching the introduction port of the air blown into the vehicle interior between the outside air introduction port 10a and the inside air introduction port 10b. The introduction port switching door 11 moves between a position where the outside air introduction port 10a is completely closed and the inside air introduction port 10b is completely opened, and a position where the inside air introduction port 10b is completely closed and the outside air introduction port 10a is completely opened. It is rotatably mounted in the air conditioning unit 3 so that it can.

  The introduction port switching door 11 is provided with an actuator 12 for driving the introduction port switching door 11. The actuator 12 controls the position of the introduction port switching door 11 according to control by the ECU 4.

  In addition, the air conditioning unit 3 includes a defroster discharge port 14a that communicates with a defroster discharge port that opens toward the vehicle interior side of the front window glass, and a driver's seat and an assistant. A vent outlet 14b communicated with the vent outlet opened toward the seat and a foot outlet 14c communicated with the leg outlet opened toward the feet of the passenger seated in the driver's seat and the passenger seat. Is formed.

In the air conditioning unit 3, an outlet switching door 16a for opening and closing the defroster outlet 14a and an outlet switching door 16b for opening and closing the vent outlet 14b and the foot outlet 14c are provided.
The outlet switching door 16a is rotatably mounted in the air conditioning unit 3 so as to be movable between a position where the defroster discharge port 14a is completely closed and a position where the defroster discharge port 14a is completely closed.
The blower outlet switching door 16a is provided with an actuator 17a for driving the blower outlet switching door 16a. The actuator 17a controls the position of the outlet switching door 16a in accordance with control by the ECU 4.

The outlet switching door 16b moves between a position where the vent outlet 14b is completely closed and the foot outlet 14c is fully opened, and a position where the foot outlet 14c is completely closed and the vent outlet 14b is fully opened. It is rotatably mounted in the air conditioning unit 3 so that it can.
The blower outlet switching door 16b is provided with an actuator 17b for driving the blower outlet switching door 16b. The actuator 17b is configured to control the position of the outlet switching door 16b in accordance with control by the ECU 4.

  In the air conditioning unit 3, a blower fan 20, an evaporator 21, an air mix door 22, a heater core 23, and an indoor condenser 24 are provided from the air inlet to the outlet.

  The blower fan 20 blows air that is blown into the passenger compartment. The blower fan 20 is provided with a blower fan motor 25 that rotates the blower fan 20. The blower fan 20 is rotated by a blower fan motor 25 to blow air introduced from the inlet toward the outlet. The rotational force of the blower fan motor 25 is changed in accordance with control by the ECU 4 so that the blower fan 20 changes the amount of air blown.

  The evaporator 21 cools and dehumidifies the air passing through the evaporator 21 by performing heat exchange between the air passing through the evaporator 21 and the refrigerant passing through the evaporator 21.

  The air mix door 22 adjusts the flow rate of air passing through the heater core 23 and the indoor condenser 24. Specifically, the air mix door 22 is located between a position where the air passing through the evaporator 21 passes through the heater core 23 and the indoor condenser 24 and a position where the air passing through the evaporator 21 does not pass through the heater core 23 and the indoor condenser 24. Is rotatably mounted in the air conditioning unit 3.

The indoor condenser 24 exchanges heat between the air passing through the indoor condenser 24 and the refrigerant passing through the indoor condenser 24.
The high-pressure and high-temperature refrigerant flowing into the outdoor condenser 32 condenses and releases heat when passing through the indoor condenser 24. Therefore, the indoor condenser 24 functions as a heat source that warms the air blown into the vehicle interior.

The air mix door 22 is provided with an actuator 26 for driving the air mix door 22. The actuator 26 controls the position of the air mix door 22 according to control by the ECU 4.
Specifically, as shown in FIG. 2, when the air conditioning operation state is the cooling operation state, the air mix door 22 causes the air that has passed through the evaporator 21 to be heated by the heater core 23 by the actuator 26 controlled by the ECU 4. And the position which does not pass the indoor capacitor | condenser 24 is taken.
On the other hand, as shown in FIG. 3, when the air-conditioning operation state is the heating operation state, the air mix door 22 causes the actuator 26 controlled by the ECU 4 to cause the air that has passed through the evaporator 21 to pass through the heater core 23 and the indoor condenser. The position which passes 24 is taken.

In FIG. 1, the air conditioning unit 3 is provided with a compressor 30, a switching valve 31, an outdoor capacitor 32, a switching valve 33, and an accumulator tank 34.
The compressor 30 is electrically operated according to control by the ECU 4 and compresses the refrigerant. That is, the compressor 30 compresses the refrigerant so that the refrigerant becomes high pressure and high temperature.

The switching valve 31 is configured by, for example, an electromagnetic three-way valve that operates according to control by the ECU 4. The switching valve 31 passes through the compressor 30 and the indoor condenser 24 and moves the refrigerant flow path toward the outdoor condenser 32 between the flow path provided with the throttle 40 and the flow path not provided with the throttle 40. To switch.
As shown in FIG. 2, when the air conditioning operation state is the cooling operation state, the switching valve 31 is not provided with a throttle 40 as a refrigerant flow path into the outdoor condenser 32 under the control of the ECU 4. A flow path is selected.
On the other hand, as shown in FIG. 3, when the air conditioning operation state is the heating operation state, the switching valve 31 is provided with a throttle 40 as a refrigerant flow path into the outdoor condenser 32 under the control of the ECU 4. The flow path is selected.

In FIG. 1, the switching valve 33 is configured by, for example, an electromagnetic three-way valve that operates according to control by the ECU 4. The switching valve 33 switches the flow path of the refrigerant that has passed through the outdoor condenser 32 between a flow path that goes into the evaporator 21 via the throttle 41 and a flow path that goes into the accumulator tank 34. .
As shown in FIG. 2, when the air-conditioning operation state is the cooling operation state, the switching valve 33 is controlled by the ECU 4 as a flow path through which the refrigerant that has passed through the outdoor capacitor 32 travels through the throttle 41. A flow path toward the inside of the evaporator 21 is selected.
On the other hand, as shown in FIG. 3, when the air conditioning operation state is the heating operation state, the switching valve 33 is controlled by the ECU 4 so that the accumulator tank 34 serves as a flow path for the refrigerant that has passed through the outdoor capacitor 32. The flow path going inward is selected.

In FIG. 1, the outdoor condenser 32 exchanges heat between the air passing through the outdoor condenser 32 and the refrigerant passing through the outdoor condenser 32.
Here, as shown in FIG. 3, since the refrigerant that has passed through the flow path provided with the throttle 40 is expanded by the throttle 40 and has a low pressure and a low temperature, when passing through the outdoor condenser 32, Heat is absorbed from the air passing through the outdoor condenser 32. For this reason, when the air conditioning operation state is the heating operation state, the refrigerant that has absorbed heat from the air passing through the outdoor condenser 32 is sucked into the compressor 30 via the accumulator tank 34.
On the other hand, as shown in FIG. 2, since the refrigerant that has passed through the flow path not provided with the throttle 40 has a high pressure and a high temperature, it condenses by releasing heat when passing through the outdoor condenser 32. To do. For this reason, when the air-conditioning operation state is the cooling operation state, the refrigerant that has dissipated heat to the air passing through the outdoor condenser 32 passes through the throttle 41 and absorbs heat by the evaporator 21, and enters the compressor 30 via the accumulator tank 34. Inhaled.

In FIG. 2, the refrigerant that has passed through the flow path provided with the throttle 41 is expanded by the throttle 41 and has a low pressure and a low temperature. Therefore, when passing through the evaporator 21, the refrigerant absorbs heat from the air passing through the evaporator 21. To do. For this reason, when the air-conditioning operation state is the cooling operation state, the air passing through the evaporator 21 is cooled by removing heat from the refrigerant.
In FIG. 1, the accumulator tank 34 temporarily stores excess refrigerant so that the compressor 30 can suck in refrigerant having a stable pressure.

Thus, when the air conditioning operation state is the cooling operation state, as shown in FIG. 2, the compressor 30, the indoor condenser 24, the switching valve 31, the outdoor condenser 32, the switching valve 33, and the throttle 41 are provided. The flow path, the evaporator 21 and the accumulator tank 34 form a cooling flow path.
On the other hand, when the air conditioning operation state is the heating operation state, as shown in FIG. 3, the compressor 30, the indoor condenser 24, the switching valve 31, the flow path provided with the throttle 40, the outdoor condenser 32, and the switching valve 33. And the accumulator tank 34 forms the flow path for heating.

  In FIG. 1, an ECU 4 is constituted by a computer unit having a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), a flash memory, an input port, and an output port. ing.

  In the present embodiment, the input port of the ECU 4 detects the pressure in the vehicle interior temperature sensor 51 that detects the temperature in the vehicle interior, the outside air temperature sensor 52 that detects the temperature of the outside air, and the pressure of the refrigerant compressed by the compressor 30. Various sensors including the refrigerant pressure sensor 53 to be connected to various controllers including the control panel 55 are connected.

  The control panel 55 includes an air-conditioning switch for switching on / off of the air-conditioning function, an air-conditioning operation state setting switch for setting the air-conditioning operation state, and an air introduction port for the air to be blown into the vehicle interior and the outside air introduction port 10a. Air-conditioning mode selection in which an air-conditioning mode selected from a combination of the ratio of the flow rate of air-conditioning air blown from the defroster outlet, the vent outlet and the foot outlet is selected. Various switches are provided, including a switch, an air volume adjustment switch for setting the flow rate of the conditioned air blown from these outlets (hereinafter also simply referred to as “blow off amount”), and a temperature setting switch for setting the set temperature. It has been.

The air conditioning mode selection switch constitutes an air conditioning mode selection unit 70 that selects one air conditioning mode from a plurality of air conditioning modes including, for example, a differential mode, a vent mode, a foot mode, and a B / L (bilevel) mode.
The differential mode is a mode in which conditioned air is blown from the defroster outlet. The vent mode is a mode in which conditioned air is blown from the vent outlet. The foot mode is a mode in which conditioned air is blown from the foot outlet. The B / L mode is a mode in which conditioned air is blown out from the vent outlet and the foot outlet.

  In the present embodiment, the vent mode and the B / L mode correspond to a first air conditioning mode that blows air-conditioned air toward the driver seat and the passenger seat of the vehicle 1, and the foot mode is seated on the driver seat and the passenger seat. This corresponds to the second air conditioning mode in which the conditioned air is blown toward the feet of the occupant.

  Various control objects such as actuators 12, 17a, 17b and 26, a blower fan motor 25, a compressor 30, and switching valves 31 and 33 are connected to the output port of the ECU 4. The ECU 4 controls various control objects based on information obtained from various sensors, various controllers, and various switches.

  For example, when the air conditioning function is turned on by the air conditioning switch of the ECU 4 and the control panel 55, the temperature of the vehicle interior detected by the vehicle interior temperature sensor 51 and the temperature set by the temperature setting switch of the control panel 55 The actuator 26 and the compressor 30 are appropriately controlled so that they are equal.

Further, in the present embodiment, when the air conditioning operation state is switched between the cooling operation state and the heating operation state by the air conditioning operation state setting switch, the ECU 4 performs the air conditioning operation switched by the air conditioning operation state setting switch. The actuator 26, the compressor 30, and the switching valves 31 and 33 are controlled so as to be in a state.
Specifically, when the air conditioning operation state is switched between the cooling operation state and the heating operation state by the air conditioning operation state setting switch, the ECU 4 stops the compressor 30 and controls the actuator 26 to control the air mix. The position of the door 22 is changed, and the switching valves 31 and 33 are controlled to switch the refrigerant flow path between the cooling flow path and the heating flow path.

  In particular, when switching the refrigerant flow path from the cooling flow path to the heating flow path by the switching valves 31 and 33, the ECU 4 stops the compressor 30 and the refrigerant when the first predetermined condition is satisfied. When the switching valves 31 and 33 are controlled so as to switch the flow path of the refrigerant, and the refrigerant flow path is switched from the heating flow path to the cooling flow path by the switching valves 31 and 33, the compressor 30 is stopped, and the first A switching control unit 71 is configured to control the switching valves 31 and 33 so that the refrigerant flow path is switched when a second condition that is set more loosely than the conditions is satisfied.

  Here, the ECU 4 determines that the first condition is satisfied when the pressure detected by the refrigerant pressure sensor 53 is less than a predetermined first pressure, and the pressure detected by the refrigerant pressure sensor 53 is the first pressure. It is determined that the second condition is satisfied when the pressure is less than a second pressure that is set higher than one pressure in advance.

  Further, the ECU 4 constitutes a timer 72 and measures the elapsed time since the compressor 30 was stopped. The ECU 4 determines that the first condition is satisfied when the elapsed time exceeds a predetermined first time, and the second time when the elapsed time exceeds a predetermined second time shorter than the first time. It is determined that the condition is met.

  In addition, when the first air conditioning mode is selected by the air conditioning mode selection unit 70, the ECU 4 is configured to loosen the second condition than when the second air conditioning mode is selected. That is, when the vent mode or the B / L mode is selected by the air conditioning mode selection switch of the control panel 55, the ECU 4 is configured to make the second condition looser than when the foot mode is selected. .

  In order to configure the ECU 4 as described above, a map as shown in FIG. 4 is stored in the ROM of the ECU 4. In the map shown in FIG. 4, the switching pressure THp and the switching waiting time THt are associated with the combination of the air conditioning operation state and the air conditioning mode.

  In FIG. 4, when the air conditioning operation state is switched from the cooling operation state to the heating operation state, when the air conditioning mode is the differential mode, Ph1 is selected as the switching pressure THp, and the air conditioning mode is the vent mode or the B / L mode. When the air conditioning mode is the foot mode, Ph3 is selected as the switching pressure THp. Here, Ph1, Ph2, and Ph3 satisfy Ph1> Ph2> Ph3.

  Similarly, when the air conditioning operation state is switched from the cooling operation state to the heating operation state, when the air conditioning mode is the differential mode, Th1 is selected as the switching waiting time THt, and the air conditioning mode is the vent mode or the B / L mode. When the air conditioning mode is the foot mode, Th3 is selected as the switching waiting time THt. Here, Th1, Th2, and Th3 satisfy Th1 <Th2 <Th3.

  Further, when the air conditioning operation state is switched from the heating operation state to the cooling operation state, when the air conditioning mode is the differential mode, Pc1 is selected as the switching pressure THp, and the air conditioning mode is the vent mode or the B / L mode. In this case, Pc2 is selected as the switching pressure THp, and Pc3 is selected as the switching pressure THp when the air conditioning mode is the foot mode. Here, Pc1, Pc2, and Pc3 satisfy Pc1> Pc2> Pc3, Pc1> Ph1, Pc2> Ph2, and Pc3> Ph3.

  Similarly, when the air conditioning operation state is switched from the heating operation state to the cooling operation state, when the air conditioning mode is the differential mode, Tc1 is selected as the switching waiting time THt, and the air conditioning mode is the vent mode or the B / L mode. When Tc2 is selected as the switching waiting time THt, Tc3 is selected as the switching waiting time THt when the air conditioning mode is the foot mode. Here, Tc1, Tc2, and Tc3 satisfy Tc1 <Tc2 <Tc3, Tc1 <Th1, Tc2 <Th2, and Tc3 <Th3.

That is, in the present embodiment, Ph1 to Ph3 correspond to the first pressure, Pc1 to Pc3 correspond to the second pressure, Th1 to Th3 correspond to the first time, and Tc1 to Tc3 correspond to the second time. To do.
Further, since Pc1> Ph1, Pc2> Ph2, Pc3> Ph3, Tc1 <Th1, Tc2 <Th2, and Tc3 <Th3 are satisfied, the air conditioning operation state is switched from the cooling operation state to the heating operation state from the first condition. The second condition for switching from the operation state to the cooling operation state is set to be looser.
Further, since Ph2> Ph3, Th2 <Th3, Pc2> Pc3 and Tc2 <Tc3 are satisfied, the first condition and the second condition when the air conditioning mode is the foot mode than when the vent mode or the B / L mode are satisfied. Conditions are set loosely.

  Thus, when the air conditioning operation state is switched between the cooling operation state and the heating operation state by the air conditioning operation state setting switch, the ECU 4 stops the compressor 30 and then displays the map shown in FIG. With reference to this, it is determined whether or not the switching valves 31 and 33 may be controlled to be switched.

The air-conditioning operation state switching operation by the vehicle air conditioner 2 configured as described above according to the embodiment of the present invention will be described with reference to FIGS. 5 and 6. The air-conditioning operation state switching operation described below includes an initialization operation shown in FIG. 5 and a switching execution operation shown in FIG.
Here, the initialization operation starts when the air conditioning operation state is switched by the air conditioning operation state setting switch in a state where the air conditioning function is on. The switching execution operation is repeatedly executed until the refrigerant flow path is switched between the cooling flow path and the heating flow path after the initialization operation is performed.

In the initialization operation shown in FIG. 5, the ECU 4 stops the compressor 30 (step S1), starts the timer 72 from the initial value (step S2), and ends the initialization operation.
In the switching execution operation shown in FIG. 6, first, the ECU 4 determines whether or not the refrigerant pressure detected by the refrigerant pressure sensor 53 is less than the switching pressure THp obtained from the map based on the air conditioning operation state and the air conditioning mode. Is determined (step S11).
If the ECU 4 determines that the refrigerant pressure detected by the refrigerant pressure sensor 53 is less than the switching pressure THp, the ECU 4 switches the switching valves 31 and 33 (step S12) and operates the compressor 30 (step S12). S13), the switching execution operation is terminated.
On the other hand, when it is determined that the refrigerant pressure detected by the refrigerant pressure sensor 53 is not less than the switching pressure THp, the ECU 4 obtains the measurement time of the timer 72 from the map based on the air conditioning operation state and the air conditioning mode. It is determined whether or not the switching waiting time THt is exceeded (step S14).

Here, when it is determined that the measurement time of the timer 72 exceeds the switching waiting time THt, the ECU 4 switches the switching valves 31 and 33 (step S12), operates the compressor 30 (step S13), and switches. The execution operation is terminated.
On the other hand, when determining that the measurement time of the timer 72 does not exceed the switching waiting time THt, the ECU 4 ends the switching execution operation. In this case, the switching execution operation is repeatedly executed until the refrigerant flow path is switched between the cooling flow path and the heating flow path, that is, until steps S12 and S13 are executed.

  As described above, in the present embodiment, the refrigerant flow path is changed from the heating flow path to the cooling flow so that the switching to the cooling operation state, which requires a quicker response than the switching to the heating operation state, is made faster. In the case of switching to the path, the condition for switching the refrigerant flow path is relaxed compared to the case of switching from the cooling flow path to the heating flow path. For this reason, this Embodiment can improve the responsiveness of the air-conditioning function with respect to a passenger | crew's operation compared with the conventional one.

  Note that when the temperature inside the vehicle compartment is higher than the predetermined temperature and when the temperature of the outside air is higher than the predetermined temperature, the ECU 4 is detected by the vehicle interior temperature sensor 51 because the switching to the cooling operation state is urgently required. The second condition may be further relaxed based on at least one of the temperature in the vehicle interior and the temperature in the vehicle interior detected by the outside air temperature sensor 52.

For example, when the refrigerant flow path is switched from the heating flow path to the cooling flow path, the weight w1 that increases as the vehicle interior temperature detected by the vehicle interior temperature sensor 51 increases is used as the switching pressure THp. You may make it attach.
Further, when the refrigerant flow path is switched from the heating flow path to the cooling flow path, a weight w2 that increases as the temperature inside the vehicle compartment detected by the outside air temperature sensor 52 increases is added to the switching pressure THp. You may do it.

Further, when the refrigerant flow path is switched from the heating flow path to the cooling flow path, the weight w3 that decreases as the vehicle interior temperature detected by the vehicle interior temperature sensor 51 increases is changed to the switching waiting time THt. You may make it attach to.
When the refrigerant flow path is switched from the heating flow path to the cooling flow path, the weight w4 that decreases as the temperature inside the vehicle interior detected by the outside air temperature sensor 52 increases is set to the switching waiting time THt. You may make it attach.
Moreover, you may make it attach | subject that the air-conditioning state is turned ON by an air-conditioning switch that it is switching from the heating operation state of FIG. 4 to the cooling operation state. As a result, it can be determined that the vehicle occupant clearly requests cooling.

  Although the embodiments of the present invention have been disclosed above, it is obvious that those skilled in the art can make modifications without departing from the scope of the present invention. All such modifications and equivalents are intended to be included in the claims recited in the claims.

DESCRIPTION OF SYMBOLS 1 Vehicle 2 Air conditioner for vehicles 4 ECU
DESCRIPTION OF SYMBOLS 30 Compressor 31, 33 Switching valve 53 Refrigerant pressure sensor 55 Control panel 70 Air-conditioning mode selection part 71 Switching control part 72 Timer

Claims (4)

A compressor for compressing the refrigerant;
A vehicle air conditioner comprising: a switching valve that switches a flow path of the refrigerant compressed by the compressor between a plurality of flow paths including at least a cooling flow path and a heating flow path,
When the flow path of the refrigerant is switched from the cooling flow path to the heating flow path by the switching valve, the refrigerant is stopped when the compressor is stopped and a first predetermined condition is satisfied. Control the switching valve to switch
When the flow path of the refrigerant is switched from the heating flow path to the cooling flow path by the switching valve, the compressor is stopped, and a second condition that is set more loosely than the first condition is satisfied. The vehicle air conditioner includes a switching control unit that controls the switching valve so that the switching to the cooling channel is faster than the switching to the heating channel by switching the refrigerant channel. . A refrigerant pressure sensor for detecting the pressure of the refrigerant compressed by the compressor;
The switching control unit
Determining that the first condition is satisfied when the pressure detected by the refrigerant pressure sensor is less than a predetermined first pressure;
2. The method according to claim 1, wherein the second condition is determined to be satisfied when a pressure detected by the refrigerant pressure sensor becomes less than a second pressure set higher than the first pressure in advance. Vehicle air conditioner. A timer for measuring an elapsed time from when the compressor is stopped;
The switching control unit
Determining that the first condition is satisfied when the elapsed time exceeds a predetermined first time;
2. The vehicle air conditioner according to claim 1 , wherein the second condition is determined to be satisfied when the elapsed time exceeds a predetermined second time shorter than the first time. A first air-conditioning mode for blowing air-conditioned air toward a driver's seat and a passenger seat of the vehicle;
An air-conditioning mode selection unit that selects one air-conditioning mode from a plurality of air-conditioning modes including a second air-conditioning mode that blows out the air-conditioned air toward the feet of a passenger seated in the driver seat and the passenger seat Prepared,
The switching control unit relaxes the second condition when the first air conditioning mode is selected by the air conditioning mode selection unit than when the second air conditioning mode is selected. The vehicle air conditioner according to any one of claims 1 to 3.

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