JPH02193708A - Heat-pump type air conditioning and heating equipment for vehicle - Google Patents

Abstract

PURPOSE:To prevent reduction in heating capability by controlling the temperature of a heating medium according to a heating condition such as a high-pressure side refrigerant pressure of a refrigerating cycle detected, the temperature of air that is passed through a first heat exchanger, or the temperature of the heating medium. CONSTITUTION:During heating, a third heat exchanger 33 carries out heat-exchanging of a heating medium that generates heat when a vehicle is driven and a refrigerant to evaporate the refrigerant. As this occurs, a control means variably controls the temperature of the heating medium by means of an electromagnetic proportional relief valve 69 according to a heating condition to be detected by a detecting means, such as a discharge side refrigerant pressure of a refrigerating cycle's high pressure side, or a refrigerant compressor 34, the temperature of air that is passed through a first heat exchanger 31, or the temperature of the heating medium, i.e., that of an operating fluid in a second hydraulic circuit 6. In this manner, the chance of the refrigerating cycle's high pressure side refrigerant pressure reaching a high pressure cutting control area that stops the refrigerating cycle is reduced, inhibiting fluctuation of the temperature of the air that passes through the first heat exchanger, which in turn prevents reduction in heating capability.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a heat pump air-conditioning system for a vehicle that exchanges heat between a heat medium and a refrigerant that generate heat when the vehicle is driven, using a third heat exchanger. It relates to a heat pump air conditioning system for a vehicle that uses hydraulic oil for operating a hydraulic motor or engine cooling water for cooling an engine as a heat medium.

[Prior Art] Japanese Patent Application Laid-open No. 122462/1983 discloses a heat pump air conditioning system for a vehicle that uses hydraulic oil for operating hydraulic equipment as a heat source for heating.

This heating and cooling device includes a first heat exchanger that is disposed in a ventilation duct and functions as a refrigerant evaporator during cooling operation and a refrigerant condenser during heating operation, a second heat exchanger that functions as a refrigerant condenser during cooling operation, and a refrigeration cycle equipped with a third heat exchanger that functions as a refrigerant evaporator for exchanging heat between hydraulic oil and refrigerant during heating operation. Further, this heating and cooling device includes a hydraulic circuit for supplying hydraulic oil to the third heat exchanger during heating operation.

[Problems to be Solved by the Invention] However, in the conventional vehicle heat pump air-conditioning system having the above configuration, the temperature change of the hydraulic oil is large, so the heat absorption load on the third heat exchanger becomes large, and the first heat exchanger There was a risk that the heat dissipation load due to fluctuations in the intake air temperature in the equipment would increase.

For this reason, in the conventional heating and cooling apparatus, as the refrigerant pressure on the high-pressure side of the refrigeration cycle increases, it becomes easier to enter a high-pressure cut control range in which the operation of the refrigeration cycle is stopped.

Therefore, in conventional heating and cooling systems, during heating operation, the amount of heat released by the refrigerant in the first heat exchanger fluctuates drastically by activating the refrigeration cycle or stopping the operation of the refrigeration cycle. Since the temperature of the air passing through the heat exchanger fluctuates drastically, there has been a problem in that the heating capacity is significantly reduced.

An object of the present invention is to provide a heat pump air-conditioning system for a vehicle that is capable of suppressing fluctuations in the temperature of air passing through a fourteenth exchanger during heating operation, thereby reducing a decrease in heating capacity.

[Means for Solving the Problems] A heat pump air conditioning system for a vehicle according to the present invention includes a ventilation duct for sending air toward a vehicle interior, and a ventilation duct disposed within the ventilation duct to evaporate refrigerant during cooling operation. a first heat exchanger that functions as a refrigerant evaporator to condense the refrigerant during heating operation, and a second heat exchanger that functions as a refrigerant condenser that condenses the refrigerant during heating operation; A refrigeration cycle equipped with a third heat exchanger that functions as a refrigerant evaporator that evaporates the refrigerant by exchanging heat between the heat medium and the refrigerant that generate heat when a vehicle is driven; and a variable means for changing the temperature of the heat medium. , comprising a detection means for detecting a heating state such as the refrigerant pressure on the high pressure side of the refrigeration cycle, the temperature of the air passing through the first heat exchanger, or the temperature of the heat medium during heating operation, the detection means and a control means for controlling the variable means so as to change the temperature of the heat medium according to the heating state detected by.

Here, the variable means includes a pressure i control valve that is attached to a flow path that supplies the heat medium to the third heat exchanger and changes the temperature of the heat medium by changing the pressure of the heat medium. Alternatively, it is possible to use a variable aperture that changes the opening area of the flow path. Further, as the variable means, it is possible to use a cooler that is attached to a flow path that supplies the heat medium to the third heat exchanger and cools the heat medium only when the heating load is high. Further, as the variable means, it is possible to use a heater that is attached to a flow path that supplies the heat medium to the third heat exchanger and heats the heat medium only when the heating load is low.

As the detection means, it is possible to use a heat medium temperature sensor that detects the temperature of the heat medium or a heat medium pressure sensor that detects the pressure of the heat medium. The detection means may include an air temperature sensor that detects the temperature of the air sucked into the first heat exchanger, an air temperature sensor that detects the temperature of the air that has passed through the first heat exchanger, or an air temperature sensor that detects the temperature of the air that has passed through the first heat exchanger. It is conceivable to use a refrigerant pressure sensor that detects refrigerant pressure. Furthermore, as the detection means, the first
It is conceivable to use a refrigerant temperature sensor that detects the temperature of the refrigerant that has passed through the heat exchanger or the temperature of the refrigerant that has passed through the third heat exchanger.

[Function] The vehicle heat pump type air-conditioning device of the present invention has the following function due to the above configuration.

During the heating operation, the third heat exchanger exchanges heat between the refrigerant and the heat medium that generates heat when the vehicle is operated, so that the refrigerant absorbs the heat held by the heat medium, thereby evaporating the refrigerant. At this time, the control means controls the heat medium according to the heating state, such as the refrigerant pressure on the high pressure side of the refrigeration cycle, the temperature of the air passing through the first heat exchanger, or the temperature of the heat medium, detected by the detection means. The variable means is controlled to vary the temperature of the temperature. Therefore, the heat absorption coefficient of the refrigerant in the third heat exchanger is maintained at an appropriate value, and fluctuations in the heat radiation amount of the refrigerant in the first heat exchanger are suppressed, so that the refrigerant pressure on the high pressure side of the refrigeration cycle is maintained at an appropriate value. kept under pressure. Therefore, the refrigerant pressure on the high pressure side of the refrigeration cycle is less likely to reach the high pressure cut control range where the operation of the refrigeration cycle is stopped.

[Effects of the Invention] The vehicle heat pump air-conditioning device of the present invention has the following effects due to the above configuration and operation.

Since the refrigerant pressure on the high-pressure side of the refrigeration cycle is less likely to reach the high-pressure cut control range that stops the operation of the refrigeration cycle, fluctuations in the temperature of the air passing through the first heat exchanger can be suppressed, and heating Decrease in ability can be reduced.

[Embodiment] An embodiment of the heat pump air conditioning system for a vehicle according to the present invention will be described based on the drawings.

FIG. 1 shows a heat pump air conditioning system for civil engineering construction machinery vehicles such as crane trucks, which employs one embodiment of the present invention.

1 is a heat pump type air-conditioning system for civil engineering construction machinery vehicles such as crane trucks (hereinafter abbreviated as air-conditioning system)
shows.

The air conditioning system 1 includes a ventilation duct 2, a refrigeration cycle 3, a hydraulic circuit 4, and a control circuit 8 as a control means.

The ventilation duct 2 is for sending air toward the interior of the vehicle. The ventilation duct 2 houses a first heat exchanger 31 of the refrigeration cycle 3 and a fan 21 that generates an air flow toward the vehicle interior. A thermistor 81 is disposed within the ventilation duct 2 on the downstream side of the first heat exchanger 31.

Further, on the most downstream side of the ventilation duct 2, an upper body outlet 22, a foot outlet 23, and a defroster outlet 24 are formed to blow out air into the vehicle interior. Furthermore, the amount of air blown out from the upper body outlet 22 and the amount of air blown out from the foot outlet 23 and the defroster outlet 24 are different from the switching damper 2.
5.

The refrigeration cycle 3 includes a first heat exchanger 31 and a second heat exchanger 3.
2. Third heat exchanger 33, refrigerant compressor 34, receiver 35
, fat expansion valve 36, 37, four-way valve 38, cooling solenoid valve 301
, heating solenoid valve 302, and check valve 303.304.
305.

The first heat exchanger 31 is disposed in the ventilation duct 2 and functions as a refrigerant evaporator that exchanges heat between the refrigerant and the air sucked by the fan 21 to evaporate the refrigerant during cooling operation. The first heat exchanger 31 functions as a refrigerant condenser that exchanges heat between the refrigerant and the air sucked by the fan 21 and condenses the refrigerant during heating operation. A refrigerant pressure sensor 82 is disposed therein.

The second heat exchanger 32 mixes the refrigerant with the fan 32 during heating operation.
The refrigerant 'a1i! exchanges heat with the air blown by 1 and condenses the refrigerant! As a vessel <.

The third heat exchanger 33 functions as a refrigerant evaporator that evaporates the refrigerant by exchanging heat between the refrigerant and the hydraulic oil, which is a heat medium that generates heat when the vehicle is operated, during heating operation. The exchanger 33 is a shell-and-tube type,
A shell 331 forming an outer shell and into which hydraulic oil flows, and a tube 3 housed within the shell 331 through which a refrigerant flows.
32.

The refrigerant pressure [9134 is driven by the hydraulic motor 51 of the hydraulic circuit 4, and compresses the refrigerant into high-temperature, high-pressure refrigerant gas.

The receiver 35 temporarily stores the liquefied refrigerant that has flowed in, and supplies only the necessary amount of liquefied refrigerant to the first heat exchanger 31 or the third heat exchanger 33, which functions as a refrigerant evaporator.

The fat expansion valve 36 and the fat expansion valve 37 adiabatically expand the refrigerant and serve as a refrigerant evaporator.
Atomized refrigerant is supplied to the heat exchanger 33.

The four-way valve 38 switches the flow direction of the refrigerant between cooling operation and heating operation. This four-way valve 38 switches the refrigeration cycle 3 to the heating operation side when the electromagnetic coil 381 is turned on, and switches the refrigeration cycle 3 to the cooling operation side when the electromagnetic coil 381 is turned off.

The cooling solenoid valve 301 closes the solenoid coil 311 during cooling operation.
is turned on, the valve opens, and the electromagnetic coil 31 is turned on during heating operation.
1 is turned off, the valve closes. The heating solenoid valve 302 closes because the electromagnetic coil 312 is turned on during cooling operation, and opens because the electromagnetic coil 312 is turned on during heating operation.

The check valve 303, the check valve 304, and the check valve 305 prevent the refrigerant from flowing back.

The hydraulic circuit 4 supplies hydraulic oil as a heat medium that generates heat when the vehicle is driven to hydraulic equipment mounted on the vehicle. This hydraulic circuit 4 includes a hydraulic motor 51
A first hydraulic circuit 5 controls the rotational speed of the refrigerant, and a second hydraulic circuit 6 supplies hydraulic fluid whose heat is absorbed by the refrigerant in the third heat exchanger 33.

The first hydraulic circuit 5 includes a hydraulic motor 51 and a main hydraulic pump 52.
, a flow controller 53, an oil tank 54 serving as a reservoir for hydraulic oil, a first manual shutoff valve 55, a second manual shutoff valve 56, a hydraulic motor 57, and a check valve 58.

The hydraulic motor 51 is driven at a rotational speed that corresponds to the flow rate of hydraulic oil pumped up by the main hydraulic pump 52. Further, the hydraulic motor 51 compresses the refrigerant l! via the belt 512 wrapped around the pulley 511 and the pulleys 341 and 611. 34 and the auxiliary hydraulic pump 61 of the second hydraulic circuit 6.

The main hydraulic pump 52 is driven by the engine E, and uses hydraulic oil pumped from the oil tank 54 to drive the hydraulic motor 51.
57 is activated.

In the first hydraulic circuit 5, the amount of hydraulic oil pumped from the oil tank 54 of the main hydraulic pump 52, that is, the flow rate, changes depending on the engine rotation speed of the engine E.

For this reason, the flow controller 53 is connected to the hydraulic motor 51
The flow rate is adjusted so that the flow rate of the hydraulic oil flowing into the pump is constant.

The hydraulic motor 57 has a fan 511 for blowing cooling air to the oil cooler 65 provided in the second oil circuit 6.
to drive.

The second hydraulic circuit 6 includes an auxiliary hydraulic pump 61 and a hydraulic pump 62.
, first circulation path 63, second circulation path 64, oil cooler 65
, an electromagnetic switching valve 66, check valves 67, 68, and an electromagnetic proportional relief valve 69 as variable means.

The auxiliary hydraulic pump 61 is driven by the hydraulic motor 51 via a belt 512 and a pulley 611, and pumps up a constant flow of hydraulic oil from the oil tank 54. The hydraulic pump 62 is driven by the engine E via a belt (not shown) and a pulley (not shown), and provides back pressure to the auxiliary hydraulic pump 61.

The first circulation path 63 pumps up the hydraulic oil in the oil tank 54 with the auxiliary hydraulic pump 61 and supplies it into the third heat exchanger 33 via the electromagnetic proportional relief valve 69. This is a flow path (indicated by a solid line arrow in the figure) that returns from the oil tank 54 to the inside of the oil tank 54.

In the second circulation path 64, the hydraulic oil in the third heat exchanger 33 is passed through an electromagnetic switching valve 66 by an auxiliary hydraulic pump 61, and then passed through an electromagnetic proportional relief valve 69 to the third heat exchanger 3.
This is a flow path (indicated by a dashed line arrow in the figure) for circulating the water to No. 3.

The oil cooler 65 is a heat exchanger that exchanges heat between the hydraulic oil pumped by the auxiliary hydraulic pump 61 and the cooling air blown by the fan 571 to cool the hydraulic oil with the cooling air.

The electromagnetic switching valve 66 is a switching means for switching between the first circulation path 1321/8G3 and the second circulation path 64, and is
When the electromagnetic coil 661 is turned on, the hydraulic circuit 4 is switched to the second circulation path 64. Conversely, the electromagnetic switching valve 66 is configured so that the electromagnetic coil 661 is turned off by the control circuit 8.
Then, the second hydraulic circuit 6 is switched to the first circulation path 63.

FIG. 2 shows an electromagnetic proportional relief valve 69 provided in the second hydraulic circuit 6. As shown in FIG. The electromagnetic proportional relief valve 69 adjusts the inlet pressure (relief pressure) according to the air blowing temperature (heating state) from the first heat exchanger detected by the thermistor 81.
This is a pressure control valve that controls the temperature of hydraulic oil by changing the temperature.

This electromagnetic proportional relief valve 69 includes a valve body 71, a hydraulic oil passage 72, an electromagnetic coil 73, and a twenty-one dollar 74 in a valve body 70.
, a rod 15, an adjustment screw 16, a safety valve 17, and a pilot pressure supply path 78.

The valve body 71 moves in the vertical direction within the valve body 70 according to the pilot pressure applied from the pilot pressure supply path 78. Further, by moving the valve body 71 in the vertical direction within the valve body 70, the opening area of the hydraulic oil passage 72 is changed, and relief pressure is applied to the hydraulic oil to be supplied to the third heat exchanger 33. change. Therefore, the temperature of the hydraulic oil passing through the hydraulic oil passage 72 varies according to changes in the relief pressure.

The hydraulic oil passage 72 includes an inflow lower 21 through which the hydraulic oil pressure-fed from the auxiliary hydraulic pump 61 flows into the interior, and an outflow lower 22 through which the hydraulic oil to which relief pressure has been applied by the valve body 71 is sent to the third heat exchanger 33. has.

Further, the electromagnetic proportional relief valve 69 displaces the needle 74 connected to the rod 75 acting as an armature in the left-right direction in the drawing according to the current value supplied to the electromagnetic coil 73 from the control circuit 8. By changing the amount of leakage from the passage 761 formed in the pilot pressure supply path 78, the pilot pressure in the pilot pressure supply path 78 is changed.

79 is a drain boat that returns oil that does not contribute to the pilot pressure to the oil tank 54.

In Figure 3, the horizontal axis represents the current value (mA) supplied from the control circuit 8 to the electromagnetic coil 73, and the vertical axis represents the inlet pressure (relief pressure).
(kgf/cJ) is shown.

4 shows an electric circuit of the heating and cooling system 1, and FIG. 5 shows a controller 100 installed in the driver's seat in the vehicle interior to control the heating and cooling system 1.

A controller 100, relays 111 and 112, and a control circuit 8 are connected to a battery 80 mounted on the vehicle.

The controller 100 controls the electric motor 211 of the fan 21.
A fan switch 101 that turns on and off the fan, and a rotary temperature volume 102 that adjusts the temperature inside the vehicle are coaxially provided, and each type is manually operated independently. In addition, the controller 100 is provided with an air-conditioning/heating changeover switch 103 for switching the air-conditioning/heating device 1 between cooling operation and heating operation. Further, in the controller 100, the cooler lamp 104 lights up during the cooling operation, and the heater lamp 105 lights up during the heating operation.

The battery 80 is also connected to the cooler lamp 104, the heater lamp 105, the electric motor 322 of the fan 321, the electromagnetic coil 381 of the four-way valve 38, the electromagnetic coil 311 of the cooling electromagnetic valve 301, and the heating electromagnetic coil 311 of the cooling electromagnetic valve 301. The electromagnetic coil 312 of the electromagnetic valve 302 is connected.

A current control circuit 87 is connected to the relay 111 . The relay 111 is turned off by the control circuit 8 during cooling operation.
F is turned on by the control circuit 8 during heating operation. The relay 112 includes an electromagnetic coil 661 of the electromagnetic switching valve 66.
is connected. The relays 112 are all turned OFF by the control circuit 8 during cooling operation, and are turned OFF by the control circuit 8 during heating operation.
It is turned on and off by.

The control circuit 8 includes a thermistor 81 as a detection means, a refrigerant pressure sensor 82, a first oil temperature switch 83, a second oil temperature switch 84, and a third oil temperature switch 85, and further includes a comparison circuit 86. .

The thermistor 81 detects the temperature of air blown out from the first heat exchanger 31.

The refrigerant pressure sensor 82 is a normally open switch that detects the refrigerant pressure on the high pressure side of the refrigeration cycle 3. Refrigerant pressure sensor 8
2 is closed when the refrigerant pressure on the high pressure side of the refrigeration cycle 3 reaches the high pressure cut control range (for example, 23 kg/cd).

The first oil temperature switch 83 is disposed within the third heat exchanger 33 and detects the temperature of the hydraulic oil within the third heat exchanger 33 during heating operation. This first oil temperature switch 83 is the third one? j! ! , the temperature of the hydraulic oil in the exchanger 33 is at a temperature that can be used as a heating heat source for the refrigeration cycle 3 (for example, 30°C).
) is opened, and a switching signal for switching from the second circulation path 64 to the first circulation path 63 is sent to the control circuit 8.

The second oil temperature switch 84 is a normally open switch that is disposed in the third heat exchanger 33 and detects the temperature of the hydraulic oil in the third heat exchanger 33 during heating operation. This second oil temperature switch 8
4 is closed when the temperature of the hydraulic oil in the third heat exchanger 33 reaches a predetermined temperature (for example, 50° C.), and the first circulation path 6 is closed.
3 to the second circulation path 64 is sent to the control circuit 8.

The third oil temperature switch 85 is a thermistor that is disposed in the oil tank 54 and detects the temperature of the hydraulic oil in the oil tank 54 . This third oil temperature switch 85 is closed when the temperature of the hydraulic oil in the oil tank 54 reaches a temperature (for example, 30° C.) that can be used as a heat source for heating the refrigeration cycle 3, and the third oil temperature switch 85 is closed.
A switching signal for switching from the circulation path 611 to the first circulation path 63 is sent to the control circuit 8.

The comparison circuit 86 compares the set value of the vehicle interior temperature (1'1°C) set by the occupant with the temperature volume 102 and the blowing temperature of the air blown out from the first heat exchanger 31 (1'1°C) detected by the thermistor 81. 2°C), the blowout temperature (72°C) is near the set value (('rt -'1
”)'C) In case of lower temperature, the electromagnetic proportional relief valve 6
The current control circuit 81 is controlled to increase the current value supplied to the electromagnetic coil 73 of No. 9.

Conversely, when the blowout temperature (72°C) is around the set value ((1
When the temperature is higher than ゛□+'l'')'C), the current control circuit 87 is controlled to reduce the current value supplied to the electromagnetic coil 73 of the electromagnetic proportional relief valve 69.

Here, T'C can be arbitrarily set, for example, 5°C, 10°C, 15°C, etc.

The control circuit 8 also controls the second oil temperature switch 8 during heating operation.
When the switching signal is input from 4, the electromagnetic coil 661 of the electromagnetic switching valve 66 is turned on to switch the second hydraulic circuit 6 from the first circulation path 63 to the second circulation path 64 by turning on the relay 112. do. If the switching signal is not input from the second oil temperature switch 84 during heating operation, the relay 112 is set to 0[E, so that the second oil pressure switch 28
The electromagnetic coil 661 of the electromagnetic switching valve 66 is turned on so that the electromagnetic switching valve 66 is switched from the second circulation path 64 to the first circulation path 63.

FIG. 6 shows an operation flowchart 1 for controlling the temperature of hydraulic oil during heating operation of the control circuit 8 of this embodiment. This control is performed only when the engine E is operating.

It is determined whether or not the air conditioning/heating selector switch 103 has been switched to the heating operation side (step S1). If so (No), the relay 111 is set to 0FFL (step S2), and the temperature control of the hydraulic oil by the control circuit 8 is not executed.

When the air conditioning/heating selector switch 103 is switched to the heating operation side (Yes), the relay 111 is turned on (step S
3). Then, it is determined whether or not the current value supplied from the current control circuit 87 to the electromagnetic coil 73 of the electromagnetic proportional relief valve 69 is read (step S4). If the current value is not read (NO), The current value is 1゜mA.
(step S5), and then proceeds to step S6.

In step S4, the current value is read (Y
es), reads the vehicle interior temperature set value (11° C.) set by the temperature volume 102 (step S6);
Read the air blowing temperature ('1', 'C) from the first heat exchanger 31 detected by the thermistor 81 (step S
7), and the comparison circuit 86 compares the set value and the blowout temperature (step S8).

Next, the blowout temperature (72°C) is around the set value +
(T, -T)' It is determined whether the temperature is lower than C1. In other words, it is determined whether ('I''i-1')'C>1''2°C (step S9), (T1T
) If C > 72° C. (Yes), set the current value to (Io to I)mA (step 510), and set the increased current value (Io to I)mA to I. mA (step 511). Then step 81
Repeat the following control.

In step S9, (T r T ) "C>
If it is not 72°C (No), the blowing temperature (1°2°C
) is higher than the set value <(T1 +T)"C). In other words, ('I゛, + 'I')
”C<'1' Determine whether 2℃ (Step 5)
12). (T+T)'C<72℃ ('i'es
), the current value is (I.

Step 513) Set the current value (Io I) mA to I). Read as mA (step 514), and then repeat the control from step 81 onwards.

In step S12, ('rt +T)"C<72
When it is not ℃, that is, ('I'l-'l') 'C≦1
When 2° C.≦(T,+T)′C (NO), the maintained current value (IomA) is read (step 515).

Thereafter, the control from step 81 onwards is repeated.

Here, ImA is, for example, 50mA, 100mA, 20mA,
It can be set arbitrarily such as 0mA. However, 0≦
(1,-I)mA and (Io+-I)rnA≦800
The range of mA shall be satisfied.

Further, temperature hysteresis control may be performed, and current value control may be performed in multiple stages using a circuit having two or more set current values.

The operation of the air conditioning system 1 of this embodiment will be explained based on FIGS. 1 to 5. The heating and cooling device 1 is operated only when the engine E is operated.

The cooling operation of the heating and cooling device 1 is omitted because it performs the same function as a known device.

When the air conditioning/heating selector switch 103 is switched to the heating operation side, the electromagnetic coil 381 of the four-way valve 38 and the heating electromagnetic valve 30
2 electromagnetic coil 312 and heater lamp 105 are
N is given. Conversely, the electromagnetic coil 31 of the cooling electromagnetic valve 301
1. The electric motor 322 of the fan 321 and the cooler lamp 104 are turned off. In addition, the control circuit 8
Since the relay 111 is turned on, the electromagnetic coil 73 of the electromagnetic proportional relief valve 69 is turned on.

Also, by turning on the fan switch 101,
The electric motor 211 is turned on, and the fan 21 is driven by the rotation of the electric motor.

On the other hand, the main hydraulic pump 52 is driven by the engine E to pump up the hydraulic oil in the oil tank 54. After the flow rate is adjusted by the flow controller 53, the hydraulic oil is supplied to the hydraulic motor 51.

The hydraulic motor 51 to which a constant amount of hydraulic oil is supplied is driven by a belt 512 wound around a pulley 511 and a pulley 341.
．． 611 to the refrigerant compressor 34 and the auxiliary hydraulic pump 6
Drive 1.

Therefore, in the refrigeration cycle 3, the high-temperature, high-pressure refrigerant compressed by the refrigerant pressure m1M34 is discharged toward the first heat exchanger 31, and heating operation is started.

Here, when the temperature of the hydraulic oil in the oil tank 54 detected by the third oil temperature switch 85 has not reached a temperature that can be used as a heating heat source (for example, 30 degrees Celsius), the control circuit 8 112 is turned on. relay 112
When is turned on, the electromagnetic coil 661 is turned on, so
The second hydraulic circuit 6 is switched to the second circulation path 64 by the electromagnetic switching valve 66 . By switching to the second circulation path 64, hydraulic oil that has not reached a temperature (for example, 30° C.) that can be used as a heating heat source is prevented from flowing into the third heat exchanger 33.

The hydraulic oil is then transferred to the second circulation path 64 (auxiliary hydraulic pump 61→electromagnetic proportional relief valve 69) by the auxiliary hydraulic pump 61.
→Third heat exchanger 33→electromagnetic switching valve 66→auxiliary hydraulic pump 61).

At this time, in the third heat exchanger 33, the refrigerant and the hydraulic oil exchange heat, and the refrigerant absorbs the heat possessed by the hydraulic oil, so that the refrigerant evaporates. Then, the evaporated refrigerant is sucked into the refrigerant compressor by the suction force of the refrigerant compressor 34, compressed again, and discharged.

In addition, the compressed high-temperature refrigerant absorbs the heat possessed by the hydraulic oil, and in the first heat exchanger 31, the heat is taken away by the air passing through it, and the refrigerant becomes a low-temperature refrigerant. The air that has absorbed heat from the refrigerant is then blown into the vehicle interior by the fan 21.

At this time, the control circuit 8 controls the temperature of the air blown out from the first heat exchanger 31 detected by the thermistor 81 (
T2℃) and the temperature volume is set to 10 by the crew's operation in advance.
The set value of the vehicle interior temperature (T1° C.) set in step 2 is read and the two are compared.

Then, the control circuit 8 calculates (1゛r 'l')'C>1
When the temperature is 2° C., the current value supplied to the electromagnetic coil γ3 of the electromagnetic proportional relief valve 69 is set to (engine + I) mA.

When the current value is set to (I o + I > mA, the electromagnetic proportional relief valve 69
The pilot pressure within the valve 8 increases, causing the valve body 70 to move downward in the drawing in accordance with the current value. And the hydraulic oil passage 72
Since the opening area of the inlet decreases, the inlet pressure (relief pressure) increases. At this time, when the hydraulic oil pressure-fed from the auxiliary hydraulic pump 61 passes through the hydraulic oil passage 72, the pressure increases.
As the temperature rises, the temperature of the hydraulic oil also rises. By repeating this temperature control of the hydraulic oil, the temperature of the hydraulic oil rapidly rises to a load temperature that corresponds to the set value of the vehicle interior temperature.

Also, ('1', -'1')'C≦1゛2°C≦(T□
+]゛) When the temperature is ℃, the current value is the previous current value■. m
It is kept at A. The current value is I. By maintaining the pressure at mA, the same pressure as the previous time is applied to the hydraulic oil passing through the hydraulic oil passage 72.

Further, the control circuit 8 sets the current value to (Io-I>mA when (TI + T)'C<72°C. When the current value is set to (Io I)mA, the electromagnetic proportional In the relief valve 69, the pilot pressure in the pilot pressure supply path 78 increases, causing the valve body 70 to move upward in the figure in accordance with the current value.Then, the opening area of the hydraulic oil flow path 72 increases, so the inlet The pressure (relief pressure) decreases.At this time, the pressure of the hydraulic oil pumped from the auxiliary hydraulic pump 61 is reduced as it passes through the hydraulic oil passage 12, so the temperature of the hydraulic oil decreases.This operation By repeating oil temperature control, the temperature of the hydraulic oil quickly drops to a load temperature that matches the set value of the vehicle interior temperature.

Hydraulic motor 51, auxiliary hydraulic pump 61 and hydraulic pump 6
2, the temperature of the hydraulic oil in the oil tank 54 gradually rises, and when the temperature of the hydraulic oil in the oil tank 54 reaches, for example, 30°C, an appropriate temperature signal is sent from the third oil temperature switch 85. is sent to the control circuit 288.

Then, the control circuit 8 which receives the appropriate temperature signal from the third oil temperature switch 85 turns off the electromagnetic coil 661 by turning off the relay 112 . Then, the electromagnetic switching valve 66 is closed by OFI' of the electromagnetic coil 661, and the second hydraulic circuit 6 is switched from the second circulation path 64 to the first circulation path 6.
Can be switched to 3.

When switched from the second circulation path 64 to the first circulation path 63,
The oil tank 5 is pumped by the auxiliary hydraulic pump 61.
4 flows into the third heat exchanger 33 through an auxiliary hydraulic pump 61 and six electromagnetic proportional relief valves.

At this time, in the third heat exchanger 33, as described above, the refrigerant absorbs the heat possessed by the hydraulic oil, and the refrigerant compressor 34
It flows into the first heat exchanger 31 through the.

In the first heat exchanger 31, the air that has removed heat from the refrigerant is blown into the vehicle interior by the fan 21.

At this time, the ftd control circuit 8 reads the blowout temperature ('l'2°C) detected by the thermistor 81 and the set value (T'°C), and compares the two. Here, (
'l''l -'1') When ``C>'1''2℃, the operation described above is performed.Also, (T, -T)''C≦T2℃≦
When the temperature is (1', ±]゛)°C, the above-mentioned operation is carried out, and when (TI +T)'C<12°C, the above-mentioned operation is carried out.

Then, the temperature of the hydraulic oil in the third heat exchanger 33 detected by the second oil temperature switch 84 reaches a predetermined temperature (for example, 5
0°C), the control circuit 8 activates the relay 11.
2 is turned ON. When the relay 112 is turned on, the electromagnetic coil 661 is turned on, so the electromagnetic switching valve 66 switches the first circulation path 63 to the second circulation path 64, and the temperature of the hydraulic oil reaches a predetermined temperature (e.g. Prevent the temperature from becoming higher than 50°C.

At this time, the control circuit 8 controls the blowout temperature (1'2°C) detected by the thermistor 81 and the set value (T1°C).
) and compare them. Here, ('l',
When -'l')"C>"1'2°C, the above-mentioned operation is performed, and when (T, -T)'C≦T2°C≦(T1+]゛)°C, the above-mentioned operation is performed. Furthermore, (T1+T)”C
The above-mentioned operation is also carried out at AT, °C.

Therefore, the heat exchange efficiency between the refrigerant and the hydraulic oil in the third heat exchanger 33 can be adjusted by changing the temperature of the hydraulic oil according to the heating state such as the blowout temperature detected by the thermistor 81. can. Therefore, the amount of heat absorbed by the refrigerant from the hydraulic oil in the third heat exchanger 33 is maintained at a proper amount of heat absorbed, so that fluctuations in the amount of heat released from the refrigerant in the first heat exchanger 31 are suppressed.

Therefore, the refrigerant pressure on the high pressure side of the refrigeration cycle 3 is maintained at an appropriate pressure, and the intrusion of the pressure on the high pressure side of the refrigeration cycle 3 into the high pressure cut control area is reduced, so it is not necessary to stop the operation of the refrigeration cycle 3. It disappears. Therefore, since fluctuations in the blowout temperature can be suppressed, a decrease in the heating capacity of the air-conditioning device 1 during heating operation can be reduced.

[Other Examples] In this example, hydraulic oil for driving a hydraulic motor was used as a heat medium, but a heat source such as engine cooling water, engine oil, transmission oil, torque converter oil, etc. could be used as a heat medium. When engine cooling water is used as a heat medium, the engine cooling water is used as a heat medium flow path.

In this embodiment, the present invention was applied to a civil engineering vehicle such as a crane truck, but the present invention can also be applied to a vehicle having a heat medium that generates heat during operation of a vehicle such as a passenger car or bus.

In this embodiment, the refrigerant compressor was driven by a hydraulic motor, but the refrigerant compressor may be driven by an engine mounted on a vehicle. A clutch means may be provided.

In this embodiment, the thermistor 81 is used as the detection means, but an outside temperature sensor that detects the outside temperature can also be used as the detection means.
The heating state of the air-conditioning device may be detected from the heating load using a heating load sensor such as an inside temperature sensor that detects the inside temperature.

[Brief explanation of the drawing]

FIGS. 1 to 6 show an embodiment of a heat pump type air-conditioning system for a vehicle according to the present invention. Figure 1 is a schematic diagram showing a heat pump air conditioning system for civil engineering and construction machinery vehicles, Figure 2 is a sectional view of an electromagnetic proportional relief valve, and Figure 3 is the relationship between current value and inlet pressure in the electromagnetic proportional relief valve. Figure 4 is an electric circuit diagram showing a control device for a beat pump type air-conditioning system for civil engineering and construction machinery vehicles, and Figure 5 is a graph representing control b.
FIG. 6 is a front view showing the position A and FIG. 6 is an operational flowchart of the temperature control of the hydraulic oil during the heating operation of the control circuit. In the diagram: 1... Heat pump air conditioning system for civil engineering and construction machinery vehicles (vehicle heat pump air conditioning system) 2... Ventilation duct 3... Refrigeration cycle 4... Hydraulic circuit 5.
...First hydraulic circuit 6...Second hydraulic circuit 8...Control circuit (control means) 31...First heat exchanger 32...
-Second heat exchanger 33...Third heat exchanger 69...
Electromagnetic proportional relief valve (variable means) 81... thermistor (detection means)

Claims (1)

[Claims] 1) (a) A ventilation duct for sending air toward the vehicle interior; (b) A refrigerant evaporator disposed within the ventilation duct to evaporate refrigerant during cooling operation. , a first heat exchanger that functions as a refrigerant condenser to condense refrigerant during heating operation, a second heat exchanger that functions as a refrigerant condenser to condense refrigerant during cooling operation, and a second heat exchanger that functions as a refrigerant condenser to condense refrigerant during heating operation, and a refrigeration cycle equipped with a third heat exchanger functioning as a refrigerant evaporator that exchanges heat between a heat medium and a refrigerant that generate heat to evaporate the refrigerant; (c) variable means for changing the temperature of the heat medium; (d) ) A detection means for detecting a heating state such as the refrigerant pressure on the high pressure side of the refrigeration cycle, the temperature of the air passing through the first heat exchanger, or the temperature of the heat medium during heating operation, the detection means and a control means for controlling the variable means so as to change the temperature of the heat medium in accordance with the heating state detected by the vehicle.