DE102011116110A1 - Air conditioning apparatus for motor car, has signal generation unit assigned to air conditioning unit to actuate compressor with advance signal around time displacement immediately before starting of motor car - Google Patents

Abstract

The apparatus has a refrigerant circuit (K) connected with a compressor (11) i.e. swashplate compressor, having variable piston displacement, and an air conditioning unit (17) for actuating a drive signal (A) for adjusting the piston displacement of the compressor. A signal generation unit (31) is assigned to the air conditioning unit to actuate the compressor with an advance signal (V) around a time displacement immediately before starting of a motor car, where a predetermined minimum piston displacement at the compressor is more adjustable with the advance signal.

Description

The invention relates to an air conditioner for a vehicle according to the preamble of claim 1 and a method for controlling such an air conditioner.

In vehicle air conditioners, swash plate compressors with variable displacement are usually used. The swash plate compressor is u. a. controlled by the climate control unit as a function of the desired vehicle interior temperature and as a function of further input parameters.

From the DE 101 35 727 A1 a generic air conditioning system for a vehicle is known, in the refrigerant circuit, a swash plate compressor is connected. The swash plate compressor has a compressor shaft, which is in known manner with the internal combustion engine of the vehicle in driving connection and is therefore offset from the engine start time in rotation. On the compressor shaft sits a tilt-adjustable swash plate, which drives at least one reciprocating piston of the compressor for refrigerant compression. Depending on the inclination angle of the swash plate adjusts a stroke volume of the reciprocating piston. The swashplate is tilt-adjustable between a vertical end position without stroke volume and an end position inclined at a maximum inclination angle with maximum displacement. Such a swash plate compressor is roughly schematically in the 2 shown. As a result, the swash plate inclination angle can be adjusted by pressurizing a compressor crank chamber in which the swash plate is arranged with a control pressure. The control pressure may in turn be varied depending on the degree of opening of a compressor control valve, which may be a solenoid valve. In the de-energized state, that is, when the vehicle is parked, the control valve is in an open position, in which a pressure equalization between the crank chamber, the pressure side and the suction side of the compressor is made. In this case, the swash plate assumes a pressure compensation position. In the pressure equalization position, the swash plate is inclined by a small inclination angle.

In the above, from the DE 101 35 727 A1 known compressor results in the following starting behavior when starting the engine: Thus, the standing with the internal combustion engine in drive connection compressor shaft is set immediately after engine start in rotation. As a result, centrifugal forces act on the co-rotating swash plate. The swash plate is therefore centrifugally displaced by its pressure compensation position in which the swash plate occupies a minimum angle of inclination, moved to the vertical end position in which the associated reciprocating piston has no stroke volume. Starting from this vertical end position is then carried out in dependence on the control signal of the climate control unit, a tilt adjustment of the swash plate. The drive signal is often only with a switch-on delay of 2 to 4 seconds after the engine has been started by the climate control unit to the compressor. Accordingly, this reduces the responsiveness of the compressor. The response is also impaired if there is no gas phase in the compressor, but rather liquid refrigerant. As a result, the compressor can be regulated only in a strongly delayed response time of up to 2 minutes.

The object of the invention is to provide an air conditioner for a vehicle and a method for driving such an air conditioner in which the responsiveness of the air conditioner after engine startup is improved.

The object is solved by the features of claim 1. Preferred embodiments of the invention are disclosed in the subclaims.

The invention relates to an air conditioner with a compressor connected in the refrigerant circuit, the displacement of which is variable. The compressor is controlled in the current air conditioner operation by means of a drive signal, which is generated by the climate control unit. According to the characterizing part of claim 1, the climate control unit is additionally assigned a signal generation unit. With the signal generating unit, the compressor can already be controlled by a time offset before the engine start time with a lead signal. With the flow signal, a predetermined minimum displacement is set at the compressor, with which the compressor promotes refrigerant immediately after engine start without delay. The air conditioning can thus start with almost no time delay after engine start.

The above-described control with the flow signal already before the engine start is particularly advantageous in swash plate compressors: A swash plate compressor has in principle a compressor shaft and a tilt-adjustable, but rotatably mounted swash plate on it. The compressor shaft is in driving connection, such as belt connection, with the internal combustion engine of the vehicle, so that the compressor shaft is already driven immediately after engine start. The swash plate seated thereon can be tilt-adjusted between an end position, which is vertical to the compressor shaft, without a stroke volume and an end position, which is inclined at a maximum inclination angle, with a maximum displacement. The swash plate in turn drives an axially adjustable Reciprocating piston whose displacement varies depending on the swash plate inclination angle.

The swash plate inclination angle can be adjusted by pressurizing a compressor crank chamber in which the swash plate is arranged with a control pressure. The control pressure can in turn be varied depending on the degree of opening of a compressor control valve. The control valve may have an inlet for connection to the compressor pressure side, a first outlet for connection to the crank chamber and a second outlet for connection to the compressor suction side. The control valve is in parked vehicle in its open position in which between the crank chamber, the pressure side and the suction side of the compressor, a pressure equalization is established. In this rest position, the swash plate assumes a pressure compensation position in which the swash plate is inclined by a small inclination angle. In the closed position, on the other hand, the control valve can close the second outlet to the suction side. In this case, the suction side of the crank chamber is fluidically decoupled, while the pressure side and the crank chamber remain connected.

According to the invention, the signal generating unit can control the control valve before the engine start time with the flow signal, ie spend in a closed position.

With the control of the control valve with the flow signal already before the engine start, the fact is made use of the fact that the swash plate at not yet driven, d. H. stationary compressor shaft assumes the above-mentioned pressure equalization position. In the pressure equalization position, the swash plate is already inclined by an inclination angle. By closing the control valve before the engine starts, the crank chamber can already be acted upon at the engine start time with a certain control pressure. As a result, the inclination angle of the swash plate existing in the pressure compensation position is determined. At the engine start time, therefore, the swash plate is not adjusted back to its vertical end position without stroke volume due to the attacking centrifugal forces. Rather, the angle of inclination remains unchanged, whereby directly at the engine start time of the reciprocating can promote refrigerant with a minimum displacement.

After the engine has started, the control valve of the swash plate compressor is further controlled during operation as a function of input parameters, such as the desired outlet temperature or the evaporator temperature.

The signal generation unit may have a detection device, with which an imminent engine start can be detected, on which basis the advance signal can be generated. The detection device may detect, for example, an engine start operation of the driver. By way of example, the vehicle may have an ignition lock that can be rotationally actuated with the aid of an ignition key. By turning operation of the ignition in an end position takes place in a conventional manner, the engine start. With the detection device, an intermediate position can be detected even before reaching the end position, in which the flow signal is generated and according to the invention can be controlled before the engine start.

The advantageous embodiments and / or further developments of the invention explained above and / or reproduced in the subclaims can be used individually or else in any desired combination with one another, except, for example, in the case of clear dependencies or incompatible alternatives.

The invention and its advantageous embodiments and further developments and advantages thereof are explained in more detail below with reference to drawings.

Show it:

1 a highly simplified block diagram of an air conditioner in a vehicle;

2 in a side sectional view of a swash plate compressor;

3 a compressor control valve of the swash plate compressor from the 2 ; and

4 a diagram illustrating the control of the compressor and the engine start is illustrated.

In the 1 is roughly schematically illustrated an air conditioner for a motor vehicle. The air conditioning system has a person Ausströmer in the vehicle interior 1 opening, dashed lines shown air flow channel 3 on, through which a stream of air 5 in the vehicle interior 1 to be led. In the air flow channel 3 is a heating heat exchanger 7 a not shown coolant circuit 8th and an evaporator 9 arranged. The evaporator 9 is part of a refrigerant circuit K, in which in a known manner, a compressor 11 , a liquefier 13 as well as an expansion organ 15 are connected in series. In addition, the air conditioner has a climate control unit 17 on, with the current air conditioner operation, a drive signal A is generated, with which the stroke volume H ( 2 ) of the compressor 11 in dependence of Input parameter is set. Exemplary are in the 1 shown as input parameters, a blow-out temperature T ₁ and an evaporator temperature T ₂ . The climate control unit 17 is in signal communication with a parent electronic controller 19 , With the electronic control device 19 Beyond the climate control unit 17 , other accessories not shown (light, fuel pump, windscreen wiper, etc.) and the engine control unit 21 the internal combustion engine 23 controlled by the vehicle. The internal combustion engine 23 is in a known manner with the ancillary units in drive connection. Is exemplary in the 1 a belt drive 25 hinted that with the in the 1 and 2 shown compressor shaft 27 with the internal combustion engine 23 is in drive connection.

According to the 1 can by turning the ignition 26 in an end position E an engine start, in which via the electronic control device 19 and the engine control unit 21 the internal combustion engine 23 is put into operation. In addition, during the rotary operation of the ignition 26 by means of a sensor 29 detects an intermediate position Z of the ignition key, with which a corresponding activation signal to a signal generating unit 31 is directed. The signal generation unit 31 is in the 1 one from the climate control unit 17 separate electronic program block. Alternatively, the program block 31 also in the climate control unit 17 be integrated. With the signal generation unit 31 and the sensor 29 Therefore, an imminent engine start can already be detected before the end position E is reached. The signal generation unit 31 generates on this basis a flow signal V, with which the air conditioning compressor 11 by a time offset Δt ( 4 ) is already activated before the engine start time t _M. With the advance signal V is a predetermined minimum stroke volume H _min ( 2 ) on the compressor 11 adjustable.

The starting behavior of the compressor 11 is below on the basis of 2 and 3 specifically described a swash plate compressor 11 affect. The structure and operation of the swash plate compressor 11 are based on the 2 and 3 shown and described only to the extent necessary to understand the invention. Further details on the structure and operation of the swash plate compressor 11 are the DE 101 35 727 A1 removable.

According to the 2 has the swash plate compressor 11 the already mentioned compressor shaft 27 on that in drive connection 25 with the internal combustion engine 23 is. That is, from the engine start timing t _M, the compressor shaft 27 is driven. In addition, sits a swash plate 33 non-rotatable, but tilt-adjustable, on the compressor shaft 27 , The swash plate 33 drives an axially movable piston 34 on, which can promote H with a variable displacement H refrigerant. The swash plate 33 is between one to the compressor shaft 27 vertical end position I without stroke volume H and one with maximum inclination angle inclined end position 11 with maximum stroke volume H _max tilt-adjustable.

The swash plate tilt angle is by applying a compressor crank chamber 35 in which the swash plate 33 is arranged with a control pressure p ( 2 ) adjustable. The tilt adjustment of the swash plate 33 required Verstellmimik and their pressure-tight limitation of the crank chamber 35 are in the 2 omitted for clarity. The one in the crank chamber 35 prevailing control pressure p is dependent on an opening degree of a compressor control valve 37 variable. The control valve 37 is in the 3 executed as a solenoid valve, the before the engine start time t _M from the signal generating means 31 with the advance signal V or after engine start time t _M , ie during operation, from the climate control unit 17 is driven with the drive signal A.

According to the 3 has the control valve 37 an inlet 38 for connection to a compressor pressure side 39 ( 2 ), a first outlet 41 for connection to the crank chamber 35 and a second connection 43 for connection to the compressor suction side 47 on. In the 3 is the control valve 37 in the de-energized state, ie when the vehicle is parked, shown in which a closing element of the control valve 37 is pressed with a spring force in the open position. In the open position, pressure equalization takes place between the crank chamber 35 , the print side 39 as well as the suction side 47 , This will take the swash plate 33 a pressure compensation position III ( 2 ), which is located between the two end positions I, II. In the pressure compensation position III is the swash plate 33 inclined by a certain inclination angle, with which a minimum displacement H _min of refrigerant can be conveyed. In contrast, in a closed position of the control valve 37 the second outlet 43 to the suction side 47 closed. The suction side 47 is in this case from the crank chamber 35 fluidically decoupled while the pressure side 39 and the crank chamber 43 stay connected.

When controlling the control valve 37 with the flow signal V, the control valve goes 37 already before the engine start time t _M in the closed position on. The control valve 37 is therefore closed before the compressor shaft 27 starts to turn. The swash plate 33 Therefore, in contrast to the prior art no more due to centrifugal force are shifted to their vertical end position I (no stroke volume). Rather, the swash plate 33 already loaded at the engine start time t _M with a certain control pressure p, with the swash plate 33 already held at the beginning of the compressor shaft rotation in their pressure compensation position III. Therefore, already with the beginning of the compressor shaft rotation promotes the compressor 11 without delay with the, the pressure equalization position III associated minimum stroke volume H _min . From the engine start point in time t _M , the control valve is actuated therein by means of the drive signal A, which is generated by the climate control device 17 is generated as a function of the already mentioned input parameters. This fact is in the diagram of 4 roughly schematically reproduced, in which a solid line, a waveform of the feed / drive signal V, A is shown. The dashed line shows the engine start, while the dotted line shows the exhaust air temperature T _{2 of} the air flow detected by the dot-dash line 5 is shown.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 10135727 A1 [0003, 0004, 0023]

Claims (10)

Air conditioning system for a vehicle with a compressor connected in a refrigerant circuit (K) ( 11 ) with variable displacement (H), and with a climate control unit ( 17 ), which is the compressor ( 11 ) for adjusting the compressor stroke volume (H) with a drive signal (A), characterized in that the climate control unit ( 17 ) a signal generation unit ( 31 ) is assigned to the compressor by a time offset (.DELTA.t) immediately before an engine start of the vehicle ( 11 ) with a supply signal (V), with which a predetermined minimum displacement (H _min ) at the compressor ( 11 ) is adjustable. Air conditioning system according to claim 1, characterized in that the compressor ( 11 ) is a swash plate compressor, which is a compressor shaft ( 27 ) connected to a vehicle drive unit ( 23 ) in operational connection ( 25 ) is low starting from the engine start of the vehicle drive unit ( 23 ), and a swash plate ( 33 ) between one to the compressor shaft ( 27 ) vertical end position (I) without stroke volume (H) and a maximum inclination angle inclined end position (II) with a maximum displacement (H _max ) is tilt-adjustable. Air conditioning system according to claim 2, characterized in that the swash plate inclination angle by applying a compressor crank chamber ( 35 ), in which the swash plate ( 33 ) is adjustable, with a control pressure (p) is adjustable, which control pressure (p) in dependence on the opening degree of a compressor control valve ( 37 ) and that the signal generation unit ( 31 ) for driving with the flow signal (V) in signal communication with the control valve ( 37 ). Air conditioning system according to claim 3, characterized in that the control valve ( 37 ) an inlet ( 38 ) for connection to a compressor pressure side ( 39 ), a first outlet ( 41 ) for connection to the crank chamber ( 35 ) and a second outlet ( 43 ) for connection to the compressor suction side ( 47 ) having. Air conditioning system according to claim 4, characterized in that in a rest position the control valve ( 37 ) in an open position, in which a pressure equalization between the crank chamber ( 43 ) and the print side ( 39 ) as well as the suction side ( 47 ) and in which the swash plate ( 33 ) occupies a pressure equalization position (III) between its two end positions (I, II), in which pressure compensation position the swash plate ( 33 ) is inclined by an inclination angle with which a minimum displacement volume (H _min ) can be conveyed. Air conditioning system according to claim 4 or 5, characterized in that the control valve ( 37 ) in a closed position the second outlet ( 43 ) to the suction side ( 47 ) closes, so that the suction side ( 47 ) from the crank chamber ( 35 ) is decoupled while the print side ( 39 ) and the crank chamber ( 35 ) remain connected. Air conditioning system according to claim 5 or 6, characterized in that the control valve ( 37 ) transitions to the closed position by application of the advance signal (V) before the engine start, so that at the engine start time (t _M ) the swash plate inclination is set to the inclination in the pressure equalization position (III) with that already at the engine start time (t _M ) the minimum stroke volume (H _min ) is eligible. Air conditioning system according to one of claims 2 to 7, characterized in that from the engine start the control valve ( 37 ) in dependence on input parameters starting from the pressure equalization position (III) the inclination of the swash plate ( 33 ) regulates. Air conditioning system according to one of the preceding claims, characterized in that the signal generating unit ( 31 ) a detection device ( 29 ), which detects an imminent engine start and generates on this basis of the flow signal (V). Air conditioning system according to claim 9, characterized in that the vehicle is an ignition lock ( 26 ), which is rotatably actuated by means of an ignition key, and that the detection device ( 29 ) detects an intermediate position (Z) before reaching an ignition position (E), in which the flow signal (V) is generated.

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