JPS6124614A - Air-conditioner for vehicle - Google Patents

Abstract

PURPOSE:To efficiently perform cooling the interior of a compartment and improve comfortableness by comparing a detected value of the temperature of cool wind, cooled by an evaporator, with two previously set temperature of the least upper bound and controlling operation of a compressor according to the result of said comparison. CONSTITUTION:In the captioned device which supplies refrigerant ejected by a compressor 26 to an evaporator 25 in an air conditioning duct 19 through a condenser 28 and cools air by evaporation of the refrigerant, the temperature of a cool wind cooled by the evaporator 25 is detected by means of a temperature sensor 51, and the detected temperature T is compared with the previously set temperature T1, T2 (T1<T2) of the least upper bound in a control means 52. Then the compressor 26 is controlled to augment capability of cooling in case a result of the above-mentioned comparison is T>=T2, while it is controlled to reduce said capability in case a result of the comparison is T1 <T<T2. Further, in case a result of the comparison is T1<T<T2, if a time N which reduces capability of cooling is above a predetermined time N0, the compressor 26 is controlled to augment capability of cooling until a result T<T0 (temperature of the greatest lower bound) of comparison is attained.

Description

[Detailed description of the invention] (Technical field) The present invention relates to a vehicle air conditioner.

(Prior art) - Generally, in vehicle air conditioners, when controlling the temperature inside the vehicle, the cooling capacity of the air blower is increased or decreased by a compressor, and the temperature of the cold air cooled by the evaporator is adjusted in advance. If the temperature is higher than a preset upper limit temperature, the cooling capacity is increased; if the temperature is between the upper limit temperature and a preset lower limit temperature, the cooling capacity is decreased, and the temperature is lower than the lower limit temperature. In this case, the cooling capacity is set to zero.

Conventional vehicle air conditioners of this type include, for example,
The applicant has already filed an application as shown in Japanese Patent Application No. 57-217510. The vehicle air conditioner shown in Japanese Patent Application No. 57-217510 is equipped with two compressors, and when the cooling capacity of the evaporator is increased, the two are operated.

To decrease the temperature, one machine is operated, and to reduce it to zero, two machines are stopped.However, as shown in Figure 2, the upper limit temperature for machine operation is T, , T2 to prevent chuckling.
(T, < T2), when the temperature T of the cold air cooled by the evaporative lake falls, one machine operates when T≦T, and when the temperature T rises, one machine operates when T≦T2. I'm letting you do it.

However, in such a conventional vehicle air conditioner, once the temperature T reaches the upper limit temperature T, only one unit is operated unless the temperature T becomes higher than the upper limit temperature T2. Therefore, there is a problem in that the temperature inside the vehicle becomes high, making it uncomfortable for the occupants.

(Structure and purpose of the invention) This invention was made by focusing on the above-mentioned problems.
A compressor that compresses the refrigerant from the evaporator lake and supplies the refrigerant to the evaporator via a condenser to increase or decrease the cooling capacity of the evaporator, and a compressor that detects the temperature T of the cold air cooled by the evaporator and displays this temperature T. A temperature sensor outputs a temperature signal to be measured, and upper limit temperatures T1 and T2 (
TI<72), if T≧T2, the compressor is allowed to increase the cooling capacity, and if T1<T<T2, the compressor is allowed to decrease the cooling capacity; If the time N during which the cooling capacity is reduced is longer than the predetermined time No, the temperature T
By comprising a control means for increasing the cooling capacity of the compressor until the temperature falls below a preset lower limit temperature To, and decreasing the cooling capacity of the compressor when the time N is less than a predetermined time No, The purpose is to solve the above problems.

(Example) Hereinafter, one embodiment of the present invention will be described based on the drawings.

In Fig. 3.4, reference numeral 11 denotes a unit body, and a ventilator outlet I2 opening toward the interior of the vehicle is formed at the rear end of this unit body 11. Approximately the center of the inside of the unit body 11 is divided into upper and lower parts by a partition plate 13, and the unit body 1 one above the partition plate 3
1 is provided with a heater core 14, and the unit body 11 below the partition plate 13 serves as a bypass passage 15. An air mix door 16 is rotatably attached to the front end of the partition plate 3, and this air mix door 16 adjusts the ratio between the amount of air passing through the heater core 14 and the amount of air passing through the bypass passage 13. A blower body 18 is disposed in front of the unit body 1, and the blower body 18 and the unit body 11 are connected by a duct 19.

An inside air intake 20 and an outside air intake 21 are provided in the upper part of the blower main body 18 . adjusted. A proafan holder is attached to the lower wall of the blower main body 18, and the proafan 23 can forcefully feed air inside and outside the vehicle interior to the duct H9 side through the inside air intake port 20 and the outside air intake port 21. An evaporator 25 is disposed inside the unit main body 11 on the front side, and this evaporator 25 cools the air pumped by the proa fan 23.

2G is a compressor that can increase or decrease the cooling capacity of the evaporative lake 25, and the refrigerant compressed by this compressor 26 is sent to a condenser 28 via a flow path 27, and the refrigerant liquefied inside this condenser 28 is transferred to the flow path. 29a
, the expansion valve 29b is supplied to the air hole 25, and the air hole 25 (7)
After absorbing the heat of vaporization from the air from the proa fan 23 during evaporation in the inner s, it is transferred to the compressor 2G via the flow path 3o.
An electromagnetic clutch 34 having a coil 33 is interposed on the rotating shaft 32 of the compressor 26, which is attracted by the magnet.The electromagnetic clutch 34 is connected when the coil 33 is energized, and is disconnected when the coil 33 is no longer energized. Ru. A small diameter driven boob IJ 3 is installed on the rotating shaft 32 in front of the electromagnetic clutch 34.
5 and a large diameter driven pulley 36 are fixed. 38 is an engine, and a disk 40 is coaxially fixed to a crankshaft 39 of this engine 38.

A large diameter drive pulley 41 is rotatably attached to the crankshaft 39 in front of the disc 40 via a hair ring 42, and an armature 44 is attached to the rear side surface of the large diameter drive pulley 41 via a spring 43. ing. A coil 45 is provided on the rear side of the disc 40, and when this coil 45 is energized, the armature 44 comes into close contact with the disc 40 against the spring 43, and when it is no longer energized, the armature 44 is brought into contact with the spring 43. By being biased, the disc 4
Separate from 0. A small diameter drive pulley 46 is attached to the crankshaft 39 on the front side of the large diameter drive pulley 41 via a one-way clutch 47. The one-way clutch 47 allows the small-diameter drive pulley 46 to rotate in the same direction as the crankshaft 39, and prevents the small-diameter drive pulley 46 from rotating in the opposite direction. A heald 49 is wound around the large-diameter drive pulley 41 and the small-diameter driven pulley 46, and a heald 50 is wound around the small-diameter drive pulley 46 and the large-diameter driven pulley 36, respectively. 51 is a temperature sensor provided near the evaporator 25;
5, the temperature T of the cooled air is detected, and a temperature signal indicating this temperature T is transmitted to the control device 52. Control bag W
52 is capable of transmitting an excitation signal to the coil 33 and the coil 45 based on the temperature signal. Figure 4 shows the control device 5.
2 shows an electrical circuit diagram of No. 2. In the figure, 54 is a first comparator, and the input side of this first comparator 54 is a resistor 5.
5 and a power supply 57 via a resistor 56, and the output side is connected to a microcomputer 5 via a buffer amplifier 58.
9 person capo ~) is connected to FAI. First comparator 5
4, a variable resistor 60 is connected in parallel, and the first comparator 54
A resistor 6 is connected to the output side of the buffer amplifier 5B and the input side of the buffer amplifier 5B.
A power supply 57 is connected in series via 1.

A variable resistor 62 whose one end is grounded is connected in series to the resistor 55 and the resistor 5G, and this variable resistor 62 tD
The resistance m value changes according to a signal from the microcomputer 59. The first comparator 54 changes the resistance value of the variable resistor 62 to a set value indicating the upper limit temperature T when the temperature T is decreasing, and to a set value indicating the upper limit temperature T when the temperature T is increasing.
It is set to a setting value indicating 2. 64 is a second comparator, and the input side of this second comparator 64 is connected to a resistor 65 and a resistor 6.
6 to the power supply 57, and the output side is connected to the input capo of the microcomputer 59 via the buffer amplifier 67.
Connected to PA2. A variable resistor 68 is connected in parallel to the second comparator 64, and a power supply 57 is connected in series to the output side of the second comparator 64 and the input side of the buffer amplifier 67 via a resistor 69.

A variable resistor 70 whose one end is grounded is connected in series to the resistor 65 and the resistor 66, and the resistance value of the variable resistor 70 is changed by a signal from the microcomputer 59. Due to a change in the resistance value of the variable resistor 70, the second comparator 64 changes to the set value indicating the lower limit temperature To when the temperature T falls, and to the set value indicating the upper limit temperature T when the temperature T rises. Set. 73 is a third comparator;
The input side of the comparator 73 is connected to the power supply 57 via a resistor 74 and a resistor 75, and the output side is connected to the input port PA3 of the microcomputer 59 via a buffer amplifier 76. A variable resistor 77 is connected in parallel to the third comparator 73, and a power supply 57 is connected in series to the output side of the third comparator 73 and the input side of the buffer amplifier 76 via a resistor 78. A variable resistor 80 whose one end is grounded is connected in series with the resistor 74 and the resistor 75, and the resistance value of the variable resistor 80 is changed by a signal from the microcomputer 59. The third comparator 73 changes the resistance value of the variable resistor 80 to a set value indicating the upper limit temperature T1 when the temperature T is decreasing, and to a predetermined temperature Ti' (where T, <T,'<T2). One end of the temperature sensor 5I is the power supply 5
7, and the other end is connected to the first comparator 54 and the second comparator 6
4. Each input side of the third comparator 73 is connected in series to a capacitor 82 and a resistor 83, one end of which is grounded.

Reference numeral 84 denotes an input inverter, and the input side of this inverter 84 is connected to the output side of the second comparator 64 and the buffer amplifier 6.
7, and the output side is connected to the − of transistor 85.
- connected to the bus 86. The emitter 87 of the transistor 85 is grounded, and the collector 8B is connected to the power source 57 via the coil 33 and the power switch 89. A flywheel diode 90 is connected in parallel to the coil 33, and this flywheel diode'
90 circulates the current remaining in the coil 33 in the direction of the arrow when the transistor 85 is turned off, thereby preventing damage to the coil 33. 92 is the power switch 8
This is a power switch that works with 9, and this power switch 9
One end of 2 is connected to the power supply 57, and the other end is connected in series to the input side of the buffer amplifier 93, and to a capacitor 94 and a resistor 95 whose one end is grounded. Buffer amplifier 9
The output side of 3 is a microcomputer 590 input capo)P
Connected to A4. 97 is a transistor, the base 98 of which is connected to the output port PA5 of the microcomputer 59 via a resistor 99, the emitter 100 is grounded, and the collector 98 is connected to the power source 57 via the coil 45. There is. 103 is a flywheel diode 1 connected in parallel to the coil 45.
−′.

Hereinafter, the operation of one embodiment of the present invention will be explained based on Fig. 3.4.5.

First, the operation of the vehicle air conditioner is 1. Then,
In step 110, it is determined whether there is a human input signal of 1 to the input port PA4, that is, whether the power switch 92 and the power switch 89 are ON. (in capo)
When the input signal to PA4 is 0, proceed to step 111;
Set the output signal from output capo-1-P A 5 to O. Therefore, the transistor 97 is turned off and the coil 45
If it is, it will not be energized. Moreover, since the power switch 89 is OFF, the coil 33 is not excited either. Therefore, the armature 43 is separated from the disc 40, and the electromagnetic clutch 34
If it is blocked. As a result, the compressor 26 is stopped. Next, proceed to step knob 112, set N=O, and return to step 110 again. Here, if N, when the temperature T rises, the predetermined value T,' and the upper limit T2
Indicates the time spent between. Therefore, in step 112, the process returns to step 110 again without measuring the time N. On the other hand, when the input signal to the capo PA4 is 1, the process proceeds to step 113.

Next, in step 113, it is determined whether the signal output from the first comparator 54 and input to the input capo-PAL and the signal output from the second comparator 64 and input to the input capo-PA2 are 0. , that is, when the temperature T decreases,
Whether TNT□ or not, when temperature T rises, T
It is determined whether ≧T2. Human capo-1-PAL
and input capo) When the input signals to PA2 are both 0,
Proceeding to step 114, the output signal from output capo-1-PA 5 is set to 1. Therefore, transistor 97 is turned on and coil 45 is excited.

Moreover, the signal output from the second comparator 64 is inverted by the inverter 84 and flows into the base 86. Therefore, 85 is turned on and the coil 33 is excited. Therefore, the electromagnetic clutch 34 is connected and the armature 44
is in close contact with the disc 40. For this reason, the crankshaft 3
9 is transmitted to the rotating shaft 32 via the large-diameter drive pulley 41, the belt 49, and the small-diameter driven pulley 35, and the rotating shaft 32 rotates at a higher speed than the crankshaft 39. As a result, the compressor 26 rotates at high speed, and the cooling capacity of the evaporator 25 increases. Next, step 115
Step 1 again without measuring time N.
Return to 10. On the other hand, when either the input signal of the input capo 1P Al- or the input signal υ of the human capo 1-P A 2- is 1, for example, in this embodiment, the input capo-1 to P
When the input signal to AI is 1 and the input signal to PA2- is 0, that is, when the temperature T is decreasing, T o
<T≦TI, and when T<T≦T2 when ascending, proceed to step 7116. Next, in step 116, when the temperature T is rising, the time N is compared with a predetermined time No. When N≧NO, the process advances to step 117. Next, at the stem knob 117,
It is determined whether the input signal to AL and the input signal to input capo-1-PA2 are both 1. For entering capo
When either the input signal to PAL or the input signal to input port 1 or PA 2 is O, for example, in this embodiment, the input signal to PAL is 1, and the input signal to input port PA2 is 0. When the input signal of is 0, that is, T<T<T2
In this case, the process proceeds to step 118, and the output signal from the output port PA5 is set to 1. Therefore, transistor 97
is 0. H, and the coil 45 is excited. Moreover, the second
Since the 0 signal output from the comparator 64 is inverted by the inverter 84, the 1-run transistor 85 is turned on and the coil 33 is also excited. Therefore, the compressor 26
rotates at high speed, increasing the cooling capacity of the evaporative lake 25. In this way, when the temperature T rises, the cooling capacity of the evaporative lake 25 increases before the temperature T reaches the upper limit temperature T2, so the temperature inside the vehicle decreases before it reaches a high temperature. As a result, the occupant can ride comfortably.

When the compressor 26 continues to rotate at a higher speed, the temperature T
If the temperature falls below the preset lower limit temperature To. Here, the rotation of the compressor 26 is stopped and step 1 is performed again.
Return to 10. -, when the input signals to input capo-1-PA1% and input capo-PA2 are both 1, immediately the temperature T
T≦To when falling, T≦T when rising
1, the process advances to step 119 and output capo-1-P A
Set the output signal from 5 to 0. Therefore, transistor 97 is turned off and coil 45 is no longer excited. Moreover, since the 1 signal outputted from the second comparator 64 is demultiplexed by the inverter 84, the transistor 8
5, it is turned OFF 1, and the coil 33 is no longer excited.

Therefore, the rotation of the compressor 26 is stopped, and the interior of the vehicle is no longer cooled. Next, the process proceeds to step 120, and returns to step 110 again without measuring the time N. Again, in step 11G, when N<No, the process proceeds to step 125, where the input signal to the input port PA 1 is 0, the input signal to the input port PA2 is 0, and the input signal to the input port PA 1, PA 3 is 0. It is determined whether the input signal to is 0 or not. When the input signal to input port I-PAI is 1, the input signal to input port PA2 is 0, and the input signal to input port PA3 is 0, that is, when T1'≦T<T2, proceed to step 126, (output capo) Set the output signal from PΔ5 to O. Therefore, transistor 97 is turned off.
F, and the coil 45 is no longer excited. Moreover, the second
Since the 0 signal output from the comparator 64 is inverted by the inverter 84, the transistor 85 is turned on and the coil 33 is energized. Therefore, the electromagnetic clutch 34
When the armature 44 is connected, the armature 44 is separated from the disc 40.

By the way, the small diameter drive pulley 46 and the crankshaft 39
The crankshaft 3 of the small diameter drive pulley 46 is connected between the
A one-way clutch 47 is interposed to prevent rotation in the opposite direction to the rotation direction. For this reason, the small diameter drive pulley 46
rotates integrally with the crankshaft 39. Therefore, the rotational force of the crankshaft 39 is applied to the small diameter drive pulley 4.
6. The signal is transmitted to the rotating shaft 32 via the belt 50 and the large-diameter driven pulley 36. As a result, the rotation speed of the compressor 26 becomes low, and the cooling capacity of the Evaporator 25 is reduced. On the other hand, the rotational force of the rotating shaft 32 is applied to the small diameter driven pulley 3.
5. It is transmitted to the large diameter drive pulley 41 via the heald 49. However, the armature 44 is separated from the disc 40,
A hair ring 42 is interposed between the large diameter drive pulley 41 and the crank shirt 139.

Therefore, the rotational force of the rotating shaft 32 is applied to the crank shirt 1-
39 is not transmitted. Next, the process proceeds to step 127 to continue measuring the time N, and then returns to step 110 again. On the other hand, input number 4M or 1 of input port PAI-,
Input signal to input port PA2 is 0, input port PA
For example, in this embodiment, when the input signal to input capo 1-PA 1- is not 0, the input signal to input capo-1-PA 1- is 1, and the input signal to input capo-1-PA 2 is O1. L
Input to P A 3 ゛When the signal is 1, that is, T,
When <T<T,', the process proceeds to step 130, and the output signal from the output port PA5 is set to 0. Therefore, transistor 97 is turned off and coil 45 is no longer excited. Moreover, since the 0 signal output from the second comparator 64 is inverted by the inverter 84, the transistor 8
5 is turned on, and the coil 33 is excited. therefore,
The rotation speed of the compressor 26 becomes low, and the evaporator 2
5 cooling capacity is reduced. Next, the process proceeds to step 131, and returns to step 110 again without measuring the time N.

Incidentally, in step 116, when the temperature T is falling, the process proceeds to step 130 without measuring the time N, and the compressor 26 is rotated at a low speed.

Next, the operation of the above-mentioned embodiment will be explained with reference to the attached table and FIG. 3.4.6 when the temperature T decreases and increases.

First, when the power switch 92 is turned off, the input signal to the input port PA4 is O, so the output port 1
) The output signal from A5 is 0. Therefore, transistor 97 is turned off and coil 45 is not excited. Furthermore, the power switch 89 is turned off by interlocking with the power switch 92. For this reason,
Coil 33 is also not energized. Therefore, the compressor 26 is stopped.

Next, when the power switch 92 is turned on, the input port P
The input signal to A4 becomes 1, and the power switch 89 is also turned on.
becomes. Here, in the case of TNT2, the temperature signal output from the temperature sensor 52 is transmitted to the first ratio calibrator 54 and the second comparator 6.
4. It is larger than each set value of the third comparator 73. Therefore, the first comparator 54, the second comparator 64, and the third comparator 73 each have an input port 1-P A 1 and an input port P
A2, the signal input to input port PA3 becomes 0. Therefore, the signal output from the output port PA5 becomes I, and the transistor 97 is turned on. For this reason,
Coil 45 is energized. However, the 0 signal output from the second comparator 64 is inverted by the inverter 84,
It is supplied to the base 86. Therefore, the transistor 85
is turned on, and the coil 33 is also excited. Therefore, the compressor 26 rotates at high speed and the cooling capacity of the evaporator 25 increases.

As the compressor 26 continues to rotate at high speed, the temperature T begins to fall. Here, the first comparator 54, the second comparator 64,
In the third comparator 73, an upper limit temperature TI, a lower limit temperature To, and an upper limit temperature T are set, respectively.

When the temperature T continues to fall and becomes T1 - TST2, the first comparator 54, the second comparator 64, and the third comparator 73
The signals inputted to input port PA1, input port PA2, and input port PA3, respectively, are also 0. Therefore, the signal output from the output capo-1-P A 5 becomes 1, and the coil 45 is excited. Moreover, the 0 signal output from the second comparator 64 is transmitted to the inverter 8.
4 and supplied to the base 86. Therefore, the coil 33 is also excited. As a result, Combreno +2
6 rotates at high speed.

When the temperature T continues to fall further and becomes T o < T ≦ T1, the first comparator 54 , the second comparator 64 , and the third comparator 73 output the input capo-1-PAL and the input capo-1-, respectively.
PA2, input capo) The signal input to PA3 is ■, 0
,・1. Therefore, the signal output from output port PA5 becomes 0. Therefore, the coil 45 is no longer energized.

However, since the 0 signal output from the second comparator 64 is inverted by the inverter 84, the coil 33 is excited. Therefore, the compressor 26 rotates at a low speed,
The cooling capacity of the evaporator 25 is reduced.

When the temperature T continues to fall and becomes T≦To, the input capo-), P A 1 , and input capo-1-P from the first comparator 54, the second comparator 64, and the third comparator 73, respectively. A
2. Input Capo) All signals input to PA3 become 1. Therefore, the signal output from the output capacitor PA5 becomes 0, and the coil 45 is not excited. However, if the signal 1 outputted from the second comparator 64 is
4, the coil 33 is no longer excited. Therefore, rotation of the compressor 26 is stopped.

Next, as the rotation of the compressor 26 is stopped, the temperature T starts to rise. Here, the first comparator 54, the second comparator 6
4. The third comparator 73 respectively sets the upper limit temperature T2, the second limit temperature T, and the predetermined temperature T, '(-T, <T, '<T,
) is set to the setting value to display.

If the temperature T continues to rise and T≦T, the first comparator 54
, second comparator 64. From the third comparator 73, input capo-) PAL, input capo-1 PA2, input capo-1-P A
All signals input to 3 are 1. Therefore, the signal output from the input port PA5 becomes 0, and the coil 45 is not excited. Moreover, since the signal output from the second comparator 64 is inverted by the inverter 84, the coil 33 is not excited either. Therefore, compressor 26 remains stopped.

When the temperature T continues to rise further and becomes T<TNTl', the first comparator 54, the second comparator 64, and the third comparator 73 output the input capo-1-PA1 and input capo-1-P, respectively.
The signals manually inputted to PA 2 and input port 1 are 1.0 and ■, respectively.

Therefore, the signal output from the output capo-1-PA5 becomes O, and the coil 45 is not excited. However, since O outputted from the second comparator 64 is inverted at the inverter 84, the coil 33 is subjected to IJilIIω. Therefore, the rotation speed of the compressor 26 becomes low.

Even if compressor 2G rotates at low speed, evaporator 2
If the cooling capacity of 5 is insufficient, the temperature T will continue to rise, and T'≦T<T2. Therefore, from the first comparator 54, the second comparator 64, and the third comparator 73, the input capo-1, P A 1, input capo-IPA2, and input capo-
1-Signal 4J input to P A 3, each 1.0
．． It becomes 0. Here, the time N during which the temperature T remains in Tl'≦T<T2 is measured, and when the time N exceeds a predetermined time No, the output signal from the output port PA5 is set to 1. Therefore, the coil 45 is forcibly excited.

Furthermore, the O signal output from the second comparator 64 is inverted to 1 by the inverter 84. Therefore, the coil 33 is energized. As a result, the rotation of the compressor 26 increases, and the cooling capacity of the evaporative lake 25 increases. Therefore, before the temperature T reaches the upper limit temperature T2,
The temperature inside the vehicle is cooled, allowing passengers to ride comfortably. The rotation of the compressor 26 is forcibly continued at high speed until the temperature T reaches the lower limit temperature To, and is stopped when the temperature T becomes lower than the lower limit temperature To. On the other hand, before the time N reaches the predetermined time NO, the temperature T decreases and T≦T.
1, the first comparator 54, second comparator 64, and third comparator 73 are again set to the setting values that display the upper limit temperature T1, the lower limit temperature To, and the upper limit temperature T1, respectively. Therefore, the first comparator 54, the second comparator 64, the third
From the comparator 73, each input port PAl input capo)P
The signals input to A2 and input port PA3 are 1.0.1, respectively. Therefore, the signal output from the output port PA5 becomes 0, and the coil 45 is not excited. However, since the 0 signal output from the second comparator 64 is inverted by the inverter 84, the coil 33 is excited. As a result, the compressor 26 rotates at a low speed.

Note that if the temperature T continues to rise and becomes T≧T before the time N reaches the predetermined time NO, the first comparator 54
The signals input from the second comparator 64 and the third comparator 73 to the input port PA1, the input capo (・PA2, and the human-powered boat PA3) are all O. Therefore, the output capo-1-PA5 The signal output from the second comparator 64 becomes 1, and the coil 45 is excited.Moreover, the O signal output from the second comparator 64 is inverted by the inverter 84, so the coil 33 is also excited. , compressor 2
G rotates at high speed, and the cooling capacity of the evaporator 25 increases. Therefore, the temperature T starts to fall, and the compressor 7
The high speed rotation of the sensor is continued until the temperature T reaches the upper limit value T1 again. As a result, the occupant can ride comfortably.

(Effects of the Invention) As explained above, according to the present invention, the temperature signal from the temperature sensor is set in advance for the upper limit temperature T, T2
(Tl<T2), and if T≧T2, the compressor increases the cooling capacity of the evaporator, and T,
When <T<T, the compressor is enabled to reduce the cooling capacity, and when T<T<T2, the time N during which the compressor is allowed to reduce the cooling capacity is greater than or equal to the predetermined time No,
The cooling capacity of the compressor is increased until the temperature T becomes lower than the preset lower limit temperature To, and the cooling capacity is increased for the period of time N.
Since the compressor is equipped with a control means that reduces the cooling capacity when the temperature T is less than NO for a predetermined period of time, the interior of the vehicle is cooled before the temperature T reaches the limit temperature T2, and as a result, the occupants can feel comfortable. The effect of being able to ride the vehicle is obtained.

[Brief explanation of the drawing]

Fig. 1 is a schematic configuration diagram showing the functions of the claimed invention, and Fig. 2 shows the relationship between the temperature T of the cold air cooled by the evaporation lake and the operating number of the compressor in a conventional vehicle air conditioner. 3 is a schematic configuration diagram showing an embodiment of a vehicle air conditioner according to the present invention, FIG. 4 is an electric circuit diagram of a control device used in the embodiment, and FIG. A flow diagram illustrating the operation of the embodiment,
FIG. 6 is a graph showing the relationship between the temperature T of the cold air cooled by the evaporator and the rotation speed of the compressor in the above embodiment. 25-evaporator, 26-compressor, 28-condenser, 51-temperature sensor, 52--control device T, , T2 upper limit temperature, To-IF hot water limit temperature T,'--predetermined temperature, T-- Temperature of cold air cooled by one evaporation, N---Time during which the cooling capacity is reduced when T1<T<T2, NO-Predetermined time.

Claims (1)

[Claims] A compressor that compresses refrigerant from the evaporator and supplies the refrigerant to the evaporator via a condenser to increase or decrease the cooling capacity of the evaporator; and a compressor that detects the temperature T of the cold air cooled by the evaporator; A temperature sensor that outputs a temperature signal that displays the temperature T, and a preset upper limit temperature T_1, T for the temperature signal from the temperature sensor.
Compared with _2 (T_1<T_2), if T≧T_2,
Increase the cooling capacity of the compressor, T_1<T<
In the case of T_2, the compressor is enabled to reduce the cooling capacity, and when T_1<T<T_2, the time N during which the compressor is allowed to reduce the cooling capacity is a predetermined time N_o
In the above case, the temperature T is the preset lower limit temperature T_
a control means for increasing the cooling capacity of the compressor until the cooling capacity becomes equal to or less than o, and decreasing the cooling capacity of the compressor when the time N is less than a predetermined time N_o. harmonization device.