JPH08164733A - Air-conditioning device for vehicle - Google Patents

Abstract

PURPOSE: To prevent operational failure of refrigerant compressor, even when non/off operation of the compressor is frequent, and reduce power loss of an engine at time of not opening the refrigerating cycle. CONSTITUTION: A refrigerant compressor 16 is driven by a hydraulic motor 23 operated with oil pressure occurring in a hydraulic pump driven by an engine 21. A bypass route 26 for bypassing the hydraulic pump 22 is disposed in a hydraulic circuit 26 leading the occurring oil pressure to the hydraulic motor 23. An opening/closing valve 27 for closing the bypass route 26 only when an air-conditioning switch 31 is on, is disposed in the bypass route 26. When the air-conditioning switch 31 is on, the coolant compressor 16 is controlled in operation by means of on/off of an electromagnetic clutch 32, so that operation failure of the coolant compressor 16 is suppressed. In time of not using the freezing cycle 4, the air-conditioning switch 31 is turned off, so that oil pressure is not led to the hydraulic motor 23, and thus power loss of the engine 21 is suppressed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle air conditioner in which a refrigerant compressor is driven by a hydraulic motor.

[0002]

2. Description of the Related Art There are vehicles, such as work vehicles, in which a space for mounting a refrigerant compressor cannot be secured near the engine and the engine cannot drive the refrigerant compressor directly. In such a vehicle, first, an engine operates a hydraulic pump to generate hydraulic pressure. Then, the hydraulic pressure of the hydraulic pump is sent to a hydraulic motor provided at a site separated by a hydraulic circuit to drive the hydraulic motor. The driving force of the hydraulic motor drives the refrigerant compressor to operate the refrigeration cycle.

The operation control of a conventional refrigerant compressor is disclosed in Japanese Patent Laid-Open No.
It is disclosed in Japanese Patent Publication No. 9-64047. According to this publication, until then, the hydraulic motor was ON / OFF-controlled by opening / closing the bypass passage of the hydraulic motor with an opening / closing valve, and consequently the refrigerant compressor was ON / OFF-controlled. However, the refrigerant compressor frequently turns on due to fluctuations in air conditioning load such as indoor temperature.
-Because it is turned off, the number of times the on-off valve turns on and off becomes large as a result. Then, the on-off valve may malfunction due to dust contained in the oil, and as a result, the refrigerant compressor cannot be turned on and off. Therefore, in the technology disclosed in the publication, instead of turning on and off the refrigerant compressor by switching the hydraulic pressure, an electromagnetic clutch is provided between the hydraulic motor and the refrigerant compressor, and by turning on and off this electromagnetic clutch. Turn on the refrigerant compressor operation-O
FF.

[0004]

In the technique disclosed in the above publication, the hydraulic motor is constantly supplied with hydraulic pressure from the engine side. That is, even when the refrigerant compressor is stopped, the hydraulic motor rotates by receiving the supply of hydraulic pressure. As a result, the hydraulic motor is supplied with hydraulic pressure and rotates even during periods when air conditioning is not performed (for example, in the case of performing only the cooling operation in the refrigeration cycle, autumn, winter, spring, etc.). That is, since the hydraulic motor operates even when the air conditioning is not performed, there is a problem in that the power of the engine is lost by the amount of operation of the hydraulic motor.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances. An object of the present invention is not to cause a malfunction of the refrigerant compressor even if the refrigerant compressor has many ON-OFF operations, and a refrigeration cycle. (EN) Provided is a vehicle air conditioner capable of reducing the power loss of an engine when the engine is not operated.

[0006]

In order to achieve the above object, the vehicle air conditioner of the present invention employs the following technical means. [Means of Claim 1] An air conditioner for a vehicle includes a hydraulic pump driven by an engine to generate a hydraulic pressure, a hydraulic motor generating a rotational output by the hydraulic pressure generated by the hydraulic pump, and a hydraulic motor generated by the hydraulic motor. A refrigeration cycle equipped with a refrigerant compressor that is driven by rotational output and that sucks, compresses, and discharges a refrigerant, an electromagnetic clutch that interrupts the rotational power transmitted from the hydraulic motor to the refrigerant compressor, and an air conditioner in the vehicle compartment. A control circuit for controlling connection / disconnection of the electromagnetic clutch according to a load and a hydraulic circuit for supplying hydraulic pressure from the hydraulic pump to the hydraulic motor are provided. The hydraulic circuit includes a bypass path that bypasses the hydraulic motor and an opening / closing valve that opens and closes the bypass path.

[Means of Claim 2] In the vehicle air conditioner of Claim 1, the control circuit closes the on-off valve when the air conditioning switch is turned on, and when the air conditioning switch is turned off, It is characterized by opening the on-off valve.

[0008]

Action of the Invention and Effect of the Invention

[Operation and Effect of Claim 1] During air conditioning operation using the refrigeration cycle, the on-off valve is closed and the hydraulic motor is operated by the hydraulic pressure generated by the hydraulic pump. On the other hand, during the air conditioning operation using the refrigeration cycle, the control circuit controls the electromagnetic clutch on and off according to the air conditioning load. When the electromagnetic clutch is connected, the hydraulic motor drives the refrigerant compressor to operate the refrigeration cycle. When the electromagnetic clutch is disengaged, the rotational force of the hydraulic motor is not transmitted to the refrigerant compressor and the operation of the refrigeration cycle is stopped.

When the air conditioning operation using the refrigeration cycle is stopped, the opening / closing valve is opened, and the hydraulic pressure generated by the hydraulic pump passes through the bypass passage bypassing the hydraulic motor. For this reason,
The operation of the hydraulic motor is stopped, and the power loss of the engine due to the operation of the hydraulic motor is reduced.

As described above, during air conditioning operation using the refrigeration cycle, the operation of the refrigerant compressor is controlled by the connection and disconnection of the electromagnetic clutch, so that even if a large number of refrigerant compressors are connected and disconnected,
There is no problem that the on-off valve malfunctions. Further, when the air conditioning operation using the refrigeration cycle is stopped, the supply of hydraulic pressure to the hydraulic motor is stopped and the operation of the hydraulic motor is reduced, so the power loss of the engine is reduced.

[Operation and Effect of Claim 2] The opening / closing valve is closed by the control circuit when the air conditioning switch is on, and the opening / closing valve is opened by the control circuit when the air conditioning switch is off. In other words, there is no need to manually operate the on-off valve depending on whether the refrigeration cycle is used or not used,
Since the on-off valve is automatically controlled to open and close during air conditioning operation using the refrigeration cycle and during operation stop, the operability is excellent.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a vehicle air conditioner of the present invention will be described based on the embodiments shown in the drawings. [Configuration of Embodiment] FIG. 1 is a schematic diagram of a vehicle air conditioner mounted on a work vehicle such as a forklift vehicle, a bulldozer vehicle, or an agricultural tillage vehicle. The vehicle air conditioner 1 includes an air conditioning unit 2, a heating device 3, a refrigeration cycle 4,
It is composed of a hydraulic device 5 and a control circuit 6.

The air conditioning unit 2 is, for example, of a package type mounted on a roof covering a vehicle compartment and has a duct 7 for guiding air toward the vehicle compartment. This duct 7
Is a passage of air for introducing the air inside the vehicle interior or the air outside the vehicle interior and guiding it into the vehicle interior. A blower 8 for generating an air flow toward the vehicle interior is provided upstream of the duct 7. Further, inside the duct 7, the refrigerant evaporator 11 of the refrigeration cycle 4 is arranged on the upstream side, and the heater core 12 of the heating device 3 is arranged on the downstream side. Furthermore, in the downstream of the duct 7,
One or more outlets are provided. When multiple outlets are provided, the duct 7 is provided at each part of the occupant.
The air that has passed through is provided so that it can be blown out.

The heating device 3 has a well-known structure, and in addition to the heater core 12 described above, hot water generating means 13 for generating hot water by utilizing combustion of fuel or exhaust heat, and the hot water generating means 13. The hot water is guided to the heater core 12, and the hot water passing through the heater core 12 is returned to the hot water generating means 13 again. The hot water circuit 14 and the flow rate control valve 15 for adjusting the amount of hot water introduced to the heater core 12 are configured.

The refrigeration cycle 4 has a well-known structure,
Refrigerant compressor 16 that sucks, compresses, and discharges refrigerant by receiving the transmission of rotational power, and cools by liquefying and condensing the high-temperature and high-pressure gas refrigerant discharged from refrigerant compressor 16 by exchanging heat with outdoor air. Container 17, receiver 18 for storing the refrigerant liquefied in refrigerant condenser 17, decompression device 19 for decompressing and expanding the liquefied refrigerant supplied from this receiver 18, decompression device 19
The above-mentioned refrigerant evaporator 1 for evaporating the atomized refrigerant depressurized by
The refrigerant composed of 1 and having passed through the refrigerant evaporator 11 is sucked into the refrigerant compressor 16 again. An outdoor fan 20 is provided in the refrigerant condenser 17, and the outdoor fan 20 is operated so that the refrigerant is forcibly cooled by the outdoor air.

The hydraulic device 5 is for driving the refrigerant compressor 16, and is driven by the rotational output of the engine 21 to generate hydraulic pressure, and the hydraulic pump 22.
A hydraulic motor 23 that generates a rotational output by the hydraulic pressure generated by 2 and a hydraulic circuit 25 that guides the oil accumulated in the oil pan 24 to the hydraulic motor 23 via the hydraulic pump 22 and then to the oil pan 24 again. There is.

The hydraulic circuit 25 is provided with a bypass path 26 that bypasses the hydraulic motor 23. The bypass path 26 does not guide the hydraulic pressure generated by the hydraulic pump 22 to the hydraulic motor 23 but directly returns it to the oil pan 24. Further, the bypass passage 26 is provided with an opening / closing valve 27 that opens and closes the bypass passage 26. The opening / closing valve 27 is, for example, a solenoid valve which is closed when energized, and is closed when the air conditioner switch 31 (corresponding to an air conditioning switch) is turned on and opened when the air conditioner switch 31 is turned off.

An electromagnetic clutch 32 is provided between the hydraulic motor 23 and the refrigerant compressor 16 to connect and disconnect the rotational power transmitted from the hydraulic motor 23 to the refrigerant compressor 16. This electromagnetic clutch 32 transmits rotational power from the hydraulic motor 23 to the refrigerant compressor 16 when energized, for example.
When the power supply is stopped, the hydraulic motor 23 causes the refrigerant compressor 16
It blocks the transmission of rotational power to.

The control circuit 6, based on various input signals,
Each of the electric functional parts (the blower 8, the hot water generating means 13, the flow rate control valve 15, the outdoor fan 20, the opening / closing valve 27, the electromagnetic clutch 32) of the vehicle air conditioner 1 is energized and controlled. In addition,
As means for giving an input signal to the control circuit 6, a blower switch 33, an air conditioner switch 31, a temperature setting volume 34, a heating switch (not shown), etc. are provided.

The blower switch 33 is a switch manually operated by an occupant, and is OFF to stop the operation of the blower 8.
It is possible to set a setting, a weak setting with a small amount of blown air, a medium setting with a large amount of blown air, and a strong setting with a large amount of blown air. The control circuit 6 stops energizing the blower 8 when the blower switch 33 is set to OFF, and energizes the blower 8 at a low voltage when the blower switch 33 is set to weak, and the blower switch 33 is set to inside. Then, the blower 8 is energized with a slightly high voltage, and when the blower switch 33 is set to a high voltage, the blower 8 is energized with a high voltage.

The air conditioner switch 31 corresponds to the air conditioner switch as described above, and is manually operated by the passenger. This air conditioner switch 31 is used for the refrigeration cycle 4
Refrigeration cycle 4 with the OFF setting to stop the air conditioning operation by
It is possible to set ON and ON for air conditioning operation. When the air conditioner switch 31 is set to OFF, the control circuit 6 stops energizing the open / close valve 27 (open / close valve 27 →
When the air conditioner switch 31 is set to ON, the opening / closing valve 27 is energized (opening / closing valve 27 → closed).

The temperature setting volume 34 is a manually set temperature setting device, and the air conditioning load (cooling load, heating load) is set by the value set by the temperature setting volume 34. The control circuit 6 increases the energization (power transmission) ratio of the electromagnetic clutch 32 when the air conditioning load is set to be large and the air conditioning load is set to be small when the air conditioning switch 31 is set to ON. Then the electromagnetic clutch 3
The ratio of stopping the energization of 2 (interruption of power transmission) is increased. The control circuit 6 energizes the electromagnetic clutch 32 so that the outdoor fan 20 also operates at the same time.

The heating switch (not shown) is a switch manually operated by an occupant and can be set to an OFF setting for stopping the heating operation and an ON setting for performing the heating operation. The control circuit 6 stops the operation of the hot water generating means 13 when the heating switch is set to OFF, and operates the hot water generating means 13 when the heating switch is set to ON. Control circuit 6 with the heating switch set to ON
Is the flow control valve 1 when the air conditioning load is set to a large value.
5 is increased, and conversely, when the air conditioning load is set small, the opening of the flow rate control valve 15 is decreased.

[Operation of the Embodiment] Next, the operation of the embodiment will be described with reference to the time chart of FIG. The hydraulic pump 22 operates while the engine 21 is operating. While the engine 21 is operating, the blower switch 33 is ON (weak, medium,
When the air conditioner switch 31 is set from OFF to ON (time t in the figure) in the strong state (blower 8 operating state), the on-off valve 27 is energized to be in the closed state and the electromagnetic clutch 32. And the outdoor fan 20 is energized according to the air conditioning load by the temperature setting volume 34. When the electromagnetic clutch 32 is energized, the rotational power of the hydraulic motor 23 is transmitted to the refrigerant compressor 16.

When the on-off valve 27 is closed, the hydraulic pump 2
The hydraulic motor 23 is activated by the generated hydraulic pressure.
Then, the rotational power generated by the hydraulic motor 23 is transmitted to the refrigerant compressor 16 via the electromagnetic clutch 32, and the refrigerant compressor 16 is rotationally driven. As a result, the power consumed by the hydraulic motor 23 changes from 0% to 100%.

When the refrigerant compressor 16 is rotationally driven, the refrigerant compressor 16 sucks, compresses and discharges the refrigerant. The discharged high-temperature and high-pressure refrigerant is guided to the refrigerant condenser 17, and is forcibly cooled by the outdoor air by the operation of the outdoor fan 20 to be liquefied. As for the refrigerant liquefied in the condenser 17, only the liquid refrigerant is taken out by the receiver 18 and decompressed and expanded by the decompression device 19 to become a mist-like refrigerant. The atomized refrigerant is the refrigerant evaporator 11
It is introduced into the interior of the duct 7, takes heat of vaporization from the air flowing in the duct 7 and evaporates, and is then sucked into the refrigerant compressor 16 again. On the other hand, the air passing through the refrigerant evaporator 11 is cooled because the heat of vaporization is removed when the refrigerant evaporates. Then, the cooled air is blown into the vehicle interior from the duct 7 to cool the vehicle interior.

When the outside air temperature is low, such as in autumn, winter, and spring, the cooling operation is not desired, and the air conditioner switch 31 remains almost OFF. That is, the on-off valve 27
Is opened and closed during the summer when air conditioning is desired,
At other times, energization is stopped and the battery is opened. As described above, when the on-off valve 27 is opened, the hydraulic pressure generated by the hydraulic pump 22 passes through the bypass passage 26 that bypasses the hydraulic motor 23. Therefore, the operation of the hydraulic motor 23 is stopped, and the power consumed by the hydraulic motor 23 becomes 0%.

[Effects of Embodiment] In the vehicle air conditioner 1 of this embodiment, as described above, the operation of the refrigerant compressor 16 is controlled by the connection and disconnection of the electromagnetic clutch 32 during the cooling operation. Therefore, even if a large number of refrigerant compressors 16 are intermittently connected during the cooling operation, the malfunction of the opening / closing valve 27 is suppressed, and as a result, the malfunction of the air conditioning operation by the refrigeration cycle 4 is suppressed.

When the cooling operation is stopped, the hydraulic motor 23
The supply of hydraulic pressure to the hydraulic motor 23 is stopped, and the power consumed by the hydraulic motor 23 becomes 0% (in the conventional technique, as shown by the broken line in FIG. 2, even when the cooling operation is stopped, the hydraulic motor 23 is stopped).
A few percent of the power was consumed by rotating.
Therefore, the load on the hydraulic pump 22 becomes very small, and the power loss of the engine 21 is reduced. That is, since the power loss of the engine 21 is reduced for a long period of time when the cooling operation is not performed, the fuel consumption of the engine 21 can be significantly reduced.

Further, in this embodiment, since the opening / closing valve 27 is automatically controlled to open / close, there is no need to manually operate the opening / closing valve 27 depending on whether the air conditioning operation is in use or not, which is very easy to operate. .

[Modification] In the above embodiment, the example in which the air conditioning unit 2 is mounted on the roof is shown, but it may be mounted on other parts such as the front part, the rear part, or the side part of the passenger compartment. Although the refrigerating cycle 4 performs only the cooling operation in the above-described embodiment, the refrigerating cycle 4 may also be provided to perform the heating operation. Then, the opening / closing valve 27 is opened not only during the cooling operation but also during the heating operation.

Although the example in which the opening / closing valve 27 is automatically controlled to open / close has been described, the opening / closing valve 27 may be manually opened when the refrigeration cycle 4 is used. Although the example in which the opening / closing valve 27 is provided in the middle of the bypass passage 26 is shown, it may be provided as a three-way valve provided at the branching portion so as to open / close the bypass passage 26.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a vehicle air conditioner.

FIG. 2 is a time chart showing an operation of a cooling operation.

[Explanation of symbols]

 1 Vehicle Air Conditioner 4 Refrigeration Cycle 6 Control Circuit 16 Refrigerant Compressor 21 Engine 22 Hydraulic Pump 23 Hydraulic Motor 25 Hydraulic Circuit 26 Bypass Path 27 Open / Close Valve 31 Air Conditioner Switch (Air Conditioning Switch) 32 Electromagnetic Clutch

Claims (2)

[Claims] 1. A hydraulic pump driven by an engine to generate hydraulic pressure, a hydraulic motor generating rotational output by hydraulic pressure generated by the hydraulic pump, and a hydraulic motor driven by rotational output generated by the hydraulic motor.
A refrigeration cycle equipped with a refrigerant compressor that sucks, compresses, and discharges refrigerant, an electromagnetic clutch that connects and disconnects the rotational power transmitted from the hydraulic motor to the refrigerant compressor, and the electromagnetic valve that responds to the air conditioning load in the vehicle compartment. In a vehicle air conditioner including a control circuit for controlling engagement and disengagement of a clutch, and a hydraulic circuit that supplies hydraulic pressure from the hydraulic pump to the hydraulic motor, the hydraulic circuit includes a bypass path that bypasses the hydraulic motor. An air conditioner for a vehicle, comprising an opening / closing valve for opening / closing the bypass path. 2. The vehicle air conditioner according to claim 1, wherein the control circuit closes the opening / closing valve when the air conditioning switch is turned on and opens the opening / closing valve when the air conditioning switch is turned off. A vehicle air conditioner.