JP3268185B2 - Cabin room air conditioner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner in a cabin of a construction machine or a transportation machine such as a hydraulic excavator, a bulldozer and a forklift.

[0002]

2. Description of the Related Art FIG. 2 shows an example of an air conditioning system in a cabin of a construction machine. In FIG. 2, 100 is a cabin room, 10 is an air conditioner in the cabin room 100, 35 is a working engine, 28 is a compressor driven from the engine via a pulley 33 and a magnet clutch 34, 29 is a condenser, Reference numeral 30 denotes a receiver, 16 denotes an evaporator, and 31 denotes an expansion valve.

[0003] Reference numeral 12 denotes an air conditioner 10 in the cabin.
An inside air inlet 13 and an outside air inlet 14 are formed on the upstream side of the casing 12, and a face outlet 20, a defrost outlet 23 and a foot outlet 24 are formed on the downstream side. The inside air suction port 13 and the outside air suction port 14 are switched by an inside / outside air switching damper 15. The face outlet 20, the defrost outlet 23, and the foot outlet 24 are switched by blowing mode switching dampers 25 and 26, respectively.

In the casing 12, the evaporator 16, the heater core 17, and the blower 18 are arranged in this order from the upstream side. The evaporator 16 is connected to the compressor 28, the condenser 29,
The refrigerant circuit 102 is configured by being connected to the receiver 30, the expansion valve 31, and the like. The cooling water of the engine 35 circulates through the heater core 17, and the amount of the circulating water is controlled by a heater hot water valve 36 having a water volume adjusting function.

When the air conditioner constructed as described above is operated, the blower 18 rotates and the inside / outside air switching damper 15
The cabin room air or the outside air is sucked into the casing 12 from the inside air suction port 13 or the outside air suction port 14 selected by switching, and is cooled by passing through the evaporator 16. Next, this air is reheated by passing through the heater core 17 whose heating capacity is adjusted to match the indoor load by the heater hot water valve 36, and becomes conditioned air at a predetermined temperature. The conditioned air is blown into the cabin chamber 100 from one or two of the face outlet 20, the defrost outlet 23, and the foot outlet 24 selected by switching the blowout mode switching dampers 25 and 26.

Reference numeral 11 denotes a control device comprising a microcomputer, which includes an input / output port, a multiplexer, an A /
It has a D converter, a central processing unit (CPU), a read-only memory (ROM), a random access memory (RAM), and the like. 42 is a solar radiation sensor, 43 is an outside air temperature sensor, 4
Reference numeral 4 denotes a room temperature sensor, and detection values from a solar sensor 42, an outside air temperature sensor 43, a room temperature sensor 44, a potentiometer for detecting an opening degree of the heater hot water valve 36, and the like are input to the control device 11.

A control panel 46 installed beside the driver's seat includes an operation switch for the air conditioner 10, a switch for switching the blow-out mode, a switch for switching the inside / outside air damper 15, and a flow rate switch for switching the rotation speed of the blower 18. switch,
AUTO switch for automatically controlling air conditioning control,
A room temperature setting device and the like for setting the temperature in the cabin chamber 100 are provided, and their outputs are also input to the control device 11.

Then, the control device 11 controls the magnet clutch 34 and the blower motor 2 for the blower 18 based on the temperature control command value calculated from the input temperature control calculation element.
1. Control signals are output to the heater hot water valve 36, motor actuators 56, 57, 58 for the dampers 15, 25, 26, and the like, and the cabin chamber 100 is controlled by controlling these.
The inside temperature is controlled within the set temperature range.

Next, the cool down operation will be described. At the start of summer operation, if the auto switch is turned on and the automatic operation mode is operated, it takes a long time for the cabin interior temperature to reach the set temperature set in the room temperature setting device, so this cool down time is reduced. For this reason, by selecting the occupant 101, the mode is switched to the maximum cooling mode, and an operation that exhibits the maximum cooling capacity can be performed.

That is, a maximum cooling mode switching means is provided in the control device 11, and the output of the room temperature setting device is input to this. Then, the set temperature of the room temperature setting device is the lowest temperature (for example, 1
8 ° C.), the maximum cooling mode switching means 6
2 determines switching to the maximum cooling mode, the blower motor 21 is set to the maximum rotation speed (the air volume of the blower 18 is the maximum), and the heater hot water valve 36 is fully closed (the heating capacity of the heater core 17 is set to 0).
(Zero)), and switches the operation of the air conditioner 10 to the operation at which the maximum cooling capacity is exhibited. (Closed), and cool air is blown to the occupant 101 to enhance the cool feeling.

Further, the inside / outside air switching damper 15 is set to the inside air circulation mode (the inside air suction port 13 is fully opened, and the outside air suction port 14 is completely closed), so that a load for cooling the outside air is eliminated and a cooling load on the air conditioner is reduced. ing. In the above-described conventional air conditioning system, a method of controlling the amount of engine cooling water supplied to the heater core 17 by the heater hot water valve 36 has been adopted as a means for controlling the reheating capability of the heater core 17. Thus, an air mix damper is provided between the evaporator 16 and the heater core 17, and the heater core 1
7 may be controlled (the latter is common in general vehicle air conditioners).

In this case, in the maximum cooling mode, the air mix damper is fully closed, the entire air flow is bypassed through the heater core 17, and the heating capacity of the heater core 17 is reduced to zero.
(Zero). In the above conventional air conditioner,
As a means for inputting the switching to the maximum cooling mode to the maximum cooling mode switching means, the set temperature is set to the lowest temperature (for example, 18 ° C. to 32 ° C.) of the room temperature setting range of the room temperature setting device (for example, 18 ° C. to 32 ° C.).
Degrees Celsius).
A dedicated maximum cooling mode selection switch may be separately provided on the control panel and the switch may be turned on.

[0013]

In the conventional air conditioning system for construction equipment as described above, the occupant 101 sets the set temperature of the room temperature setting device in order to reduce the cool down time at the start of operation in summer. Set temperature range (for example, 18 ° C.
By setting the lowest temperature (for example, 18 ° C.) of 32 ° C., the operation mode of this air conditioner can be switched to the maximum cooling mode.

However, in the above conventional air conditioning system, when the cabin room temperature is high due to a stop under the scorching sun or the like, the inside / outside air switching damper 15 is fixed to the inside air circulation mode in the maximum cooling mode. Because
Since the suction temperature is high until the indoor temperature is lowered to some extent after the operation of the air conditioner 10 is started, there is a problem that the blowout temperature is high and the cooling down takes time. Immediately after the start of the operation of the air conditioner, there is also a problem that the hot air is blown to the occupant 101 due to the above-mentioned high blowout temperature.

An object of the present invention is to make the temperature in the cabin room quickly shift to a suitable temperature after starting operation,
It is an object of the present invention to provide an air conditioner for a cabin room in which a cool-down time is shortened and a cabin room can be kept at an appropriate temperature during operation.

[0016]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems. The gist of the present invention is to provide an outside air suction port opening to the outside air, an inside air suction port opening to the cabin chamber for air suction, and a cabin. An evaporator for cooling the air in the cabin chamber and a blower for circulating the cooling air through the evaporator are housed in a casing having an air outlet for blowing out air into the chamber. In an air conditioner provided with an inside / outside air switching damper for switching between opening and closing with a suction port, a temperature control calculation element detecting means for detecting a temperature control calculation element such as a cabin indoor temperature, an outside air temperature, and the like. A room temperature setting means set within the range, a detection signal of the temperature control operation element, and a room temperature set value set in the room temperature setting means, to control the cabinet. An operation mode determining means for determining an operation mode of the air conditioner such that the room temperature becomes the room temperature set value; and a heating capacity of a heating means such as a heater core when the maximum cooling air operation mode is selected. To the maximum cooling operation for reducing the air temperature to zero, and when the detected value of the cabin room temperature exceeds a predetermined reference temperature difference from the detected value of the outside air temperature, the inside / outside air switching damper is caused to take in the outside air suction. A maximum cooling mode switching means for switching to an outside air introduction mode in which the opening is open and the inside air suction port is closed, is provided in the cabin room air conditioner.

According to the above means, when the maximum cooling mode switching means is switched to the maximum cooling mode, the maximum cooling mode switching means blows the air volume of the blower to the maximum, the heating capacity of the heating means such as the heater core to zero, and blows out the air. the mode switching damper is the face air outlet, to the maximum cooling mode operation of the switching obtain a <br/> together, after the start of operation of the inside and outside air switching damper T ₁ -T _0> a
(T ₁ = cabin room temperature, T ₀ = outside air temperature, A = inside /
During the outside reference value, the outside air suction port is opened and the inside air suction port is closed to switch to the outside air introduction mode. Further above maximum cold
The chamber mode switching means closes the outside air suction port when the cabin room temperature T ₁ decreases due to the continuation of operation and T ₁ −T ₀ ≦ A,
Open the inside air suction port and switch to the inside air circulation mode.

Therefore, when heat is trapped in the cabin room and the room temperature is high, at the start of operation, while the room temperature falls to the set temperature level, the outside air having a temperature lower than the room temperature is discharged from the outside air suction port. Is introduced, it is possible to reduce the indoor cooling load. When the cabin indoor temperature decreases and the indoor cooling load decreases, the maximum cooling mode switching means cancels the maximum cooling mode, opens the inside air suction port, closes the outside air suction port, and switches to the inside air circulation. The time required for downtime can be reduced.

In the above means, the maximum cooling mode switching means is provided when the cabin room set temperature input from the room temperature setting means is near the lower limit of the set range, or a changeover switch provided separately from the room temperature setting means. Another specific means of the present invention is that the air conditioner is configured to be operated in the maximum cooling operation mode by an input from the air conditioner.

According to the above means, when the cabin room temperature becomes close to the lower limit of the set compatible temperature range, the maximum cooling mode switching means automatically switches the air conditioner and the inside / outside air switching damper to the maximum cooling operation mode as described above. As a result, the cool-down time is shortened in addition to the first means, and the temperature in the cabin is maintained at a comfortable temperature.

Further, the switching to the maximum cooling operation mode can be performed at any time by a separately provided changeover switch.
Switching to the maximum cooling operation mode can be easily performed even when the room temperature setting means fails, and control operability is improved.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to FIGS. FIG. 1 is a control block diagram in an air conditioning system for construction equipment according to an embodiment of the present invention. Here, the hardware configuration of the air conditioning system according to this embodiment is substantially the same as that of FIG.

In FIG. 1, reference numeral 60 denotes a control device, which comprises an operation mode determining means 61, a maximum cooling mode switching means 62, a set room temperature storage means 47 and an output means 63. 4
Reference numeral 6 denotes a control panel installed in the cabin room 100, which includes a room temperature setting device 471, an AUTO (auto) switch 4
8 and so on. 41 is a potentiometer, 42 is a solar radiation sensor, 43 is an outside air temperature sensor, and 44 is a room temperature sensor.

Set room temperature storage means 47 of controller 60
In the table, an appropriate temperature of the cabin indoor temperature is set within a certain temperature range. Preferably, the room temperature setting unit 471 allows the driver to manually input a temperature (which may be an arbitrary temperature) in a range equivalent to the compatible temperature stored in the set room temperature storage means 47 from the control panel 46. It was done.

Reference numeral 481 denotes a changeover switch which, as will be described later, causes the maximum cooling mode switching means 62 to switch to the maximum cooling operation mode at any time irrespective of the set temperature of the cabin room temperature.

A potentiometer 41, a solar radiation sensor 42,
The temperature control calculation elements from the outside air temperature sensor 43, the room temperature sensor 44, the set room temperature storage means 47, the room temperature setting device 471, the AUTO switch 48, etc. are the operation mode determination means 6 of the control device 60.
1 is input. Then, the operation mode determining means 61 calculates a temperature control command value from the output of these temperature control calculation elements, and based on the temperature control command value, sets the air-conditioning apparatus 10 so that the cabin room temperature becomes the set temperature. Is determined. Therefore, when the AUTO switch 48 is turned ON, the automatic operation mode in the above process is determined, and when each manual switch on the control panel 46 is operated, the selected operation mode is determined. The output of the outside air temperature sensor 43, the room temperature sensor 44, and the output of the room temperature setting unit 471 and the set temperature of the cabin room stored in the set room temperature storage unit 47 are also input to the maximum cooling mode switching unit 62. The maximum cooling mode switching means 62 is provided with the room temperature setting device 471 input thereto.
From the cabin room temperature set in the set room temperature storage means 47 (for example, 18 ° C.
When the temperature is near the lower limit (for example, 18 ° C.), the switching to the maximum cooling mode is determined, and the blower motor 21 is set to the maximum number of revolutions, that is, the air volume of the blower 18 is set to the maximum.
6 is fully closed, and the blowout mode switching dampers 25 and 26 are in face mode (defrost blowout port 23 and foot blowout port 24).
Is closed and the face air outlet 20 is opened), the inside / outside air switching damper 15 is T ₁ −T ₀ > A (T ₁ = cabin room temperature,
T ₀ = outside air temperature, A = inside / outside determination reference value (for example, 3d
eg · ° C)), the outside air introduction mode (inside air suction port 13)
Is closed and the outside air suction port 14 is opened), and when T ₁ −T ₀ ≦ A, it is determined to switch to the inside air circulation mode (close the outside air suction port 14 and open the inside air suction port 13).

The result of this determination is output to the blower motor 21, the heater hot water valve 36, the motor actuators 57 and 58 of the blow-out mode switching dampers 25 and 26, and the motor actuator 56 of the inside / outside air switching damper 15 via the output means 63. 18, the heater hot water valve 36 is fully closed, the blowout mode switching dampers 25 and 26 are switched to the face blowing mode, and the inside / outside air switching damper 15 introduces outside air when T ₁ −T ₀ > A. In the mode, T ₁ -T ₀
When ≤A, the mode is switched to the inside air circulation mode.

The maximum cooling mode switching signal from the maximum cooling mode switching means 62 is also output to the operation mode determining means 61. Upon receiving this output signal, the automatic operation command from the operation mode determining means 61 is stopped. Is done. Thus, when the vehicle is stopped under the scorching sun or the like and the cabin interior temperature is high and the occupant 101 selects the maximum cooling mode at the start of the operation, the air volume of the blower 18 is maximized by the above operation, and the heater hot water valve 36 is completely turned off. When closed, the blowout mode switching dampers 25 and 26 are switched to the face mode as before, but the inside / outside air switching damper 15 is initially in the outside air introduction mode, the room temperature of the cabin chamber 100 decreases, and the room temperature is changed to the outside air temperature and A When the value falls to the sum (T ₀ + A) of the value (the reference value for inside / outside determination, for example, 3 deg ° C.), the mode is switched to the inside air circulation mode.

When the changeover switch 481 is turned on, the maximum cooling mode switching means 62 is switched to the maximum cooling operation mode as described above regardless of the setting of the cabin room temperature from the room temperature setting device 471.

[0030]

The present invention is configured as described above.
According to the present invention, when the cabin room is filled with heat due to a stop under the scorching sun and the room temperature is high, the maximum cooling mode switching unit and the operation mode determining unit cooperate to set the maximum cooling mode operation. After starting operation,
While the cabin interior temperature is lowered and the temperature is reduced to the sum of the outside air temperature and the reference temperature difference, the outside air having a temperature lower than the room temperature is introduced by switching the cabin inside / outside air switching damper. The cooling load can be reduced. Then, when the cabin indoor temperature decreases and the indoor cooling load decreases, the maximum cooling mode switching means cancels the maximum cooling mode operation to the inside air circulation and switches to the inside air circulation, so that the time required for the cool down can be reduced. The cooling sensation for the occupant can be further increased. In addition, immediately after the start of the operation of the air conditioner, outside air having a temperature lower than the cabin room temperature is introduced, so that the outlet temperature is lower than that of the conventional air conditioner. be able to.

According to the second aspect of the present invention, the following effect can be obtained in addition to the above. That is, when the cabin indoor temperature is near the lower limit of the set compatible temperature range, the maximum cooling mode switching means automatically switches the air conditioner and the inside / outside air switching damper to the maximum cooling operation mode as described above.
In addition to the first means, the cool-down time is shortened and the temperature in the cabin is maintained at a comfortable temperature.

Further, the mode can be switched to the maximum cooling operation mode at any time by a separately provided changeover switch.
Switching to the maximum cooling operation mode can be easily performed even when the room temperature setting means fails, and control operability is improved.

[Brief description of the drawings]

FIG. 1 is a control block diagram of a construction machine air conditioning system according to an embodiment of the present invention.

FIG. 2 is a hardware configuration diagram of the air conditioning system for construction equipment.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 air conditioner 11 control device 12 casing 13 inside air suction port 14 outside air suction port 15 inside and outside air switching damper 16 evaporator 17 heater core 18 blower 21 blower motor 25, 26 blowout mode switching damper 28 compressor 36 heater hot water valve 43 outside temperature sensor 44 room temperature sensor 46 Control panel 47 Set room temperature storage means 60 Controller 61 Operation mode determination means 62 Maximum cooling mode switching means 471 Manual room temperature setting device 100 Cabin room

Continuation of the front page (72) Inventor Atsushi Yamakawa 4-10-1, Yoga, Setagaya-ku, Tokyo New Caterpillar Mitsubishi Corporation (56) References JP-A-62-244713 (JP, A) JP-A-59-70219 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) B60H 1/00 101 B60H 1/00 103

Claims (2)

(57) [Claims] An evaporator for cooling air in a cabin chamber in a casing having an outside air suction port opening to the outside air, an inside air suction port opening to a cabin chamber, and an air blowing port opening to a cabin chamber, and the evaporator. Temperature control elements such as a cabin indoor temperature and an outside air temperature in an air conditioner that houses a blower that circulates cooling air through the air conditioner and that has an inside / outside air switching damper that switches between opening and closing of the outside air suction port and the inside air suction port. A temperature control calculation element detecting means for detecting the temperature control element, a room temperature setting means for setting the cabin room temperature within a predetermined temperature range, a detection signal of the temperature control calculation element and a room temperature set value set in the room temperature setting means. Operating mode determining means for determining an operating mode of the air conditioner such that the cabin indoor temperature becomes the room temperature set value; When the large cooling operation mode is selected, the air conditioner is switched to the maximum cooling operation in which the air volume of the blower is maximum and the heating capacity of the heating means such as the heater core is zero, and the detected value of the cabin room temperature is higher than the detected value of the outside air temperature. a maximum cooling mode switching means for switching the inside / outside air switching damper to an outside air introduction mode in which the outside air suction port is opened and the inside air suction port is closed when a predetermined reference temperature difference is exceeded.
Cabin chamber of the air conditioner, wherein the this. 2. The maximum cooling mode switching means, when the cabin room set temperature input from the room temperature setting means is near the lower limit of the setting range, or an input from a changeover switch provided separately from the room temperature setting means. The cabin room air conditioner according to claim 1, wherein the air conditioner is operated in a maximum cooling operation mode.