DE102008053998A1 - Compressor for generating compressed air for a motor vehicle - Google Patents

Abstract

The invention relates to a compressor (10) for generating compressed air, in particular for a motor vehicle, with a dead space valve (12) for relieving the compressor (10) outside a compressed air delivery phase. According to the invention it is provided that the dead space valve (12) is electrically actuated. The invention further relates to a method for operating a compressor.

Description

The The invention relates to a compressor for compressed air generation, in particular for a motor vehicle, with a dead space valve for relief of the compressor outside a compressed air delivery phase.

The The invention further relates to a method for operating a compressor for generating compressed air, in particular for a motor vehicle, wherein to relieve the compressor outside a compressed air production phase a dead space valve is opened.

Compressors for generating compressed air can be relieved of pressure during an air supply phase, while the compressed air is fed into a system downstream of the compressor, in order to save energy. For this purpose, the compressor may include a dead space valve, which connects, for example, a closed dead space with a compression space of the compressor to allow breathing of the compressor in the dead space, or the compression space opens to the environment, to a non-pressurized conveying air into the environment to allow. To control and operate the dead space valve is doing, such as from the DE 39 09 531 A1 known, already used by the compressor compressed air.

Around However, the compressor with the help of compressed air, so a pneumatic Shifting medium, to relieve, is a relative elaborate piping between the compressor and a compressor in a funding phase after ordered compressed air treatment plant necessary to compressed air to operate the dead space valve attributed to the compressor.

Of the Invention is therefore the object of the construction effort and to reduce the stressed space of unloadable compressors.

These The object is achieved with the features of the independent claims solved.

advantageous Refinements and developments of the invention will become apparent the dependent claims.

Of the inventive compressor is based on the generic State of the art in that the dead space valve electrically is operable. By providing an electrical connection, over the dead space valve is electrically actuated, can on an elaborate pipe guide for a pneumatic Pressure medium, for example, processed compressed air, be waived.

Preferably is provided that a relief hole in a valve body the Schadraumventils is provided to the valve body relieve in each switching position of Schadraumventils. Is the Valve body of Schadraumventils in each switching position relieved of the dead space valve, that is, it results no resulting pressure-related forces on the valve body, can the necessary for switching the dead space valve Forces are chosen low, resulting in an electric Pressing the dead space valve to reduce the Energy consumption leads. A pressure relief of the valve body is in particular at an electrical actuation of the dead space valve possible because there are no control surfaces for power transmission from an actuating medium on the valve body necessary. Furthermore, in this way the switching time of Dead space valve can be reduced, which during the the switching occurring undesirable mechanical loads be limited by air inlet and outlet valves of the compressor.

Usefully can be provided that the dead space valve a solenoid and a coil. A combination of a solenoid with a Coil for actuating the dead space valve is a mature and reliable possibility of an electric Controllability of Schadraumventils to realize.

Especially However, it is preferred that the Schadraumventil a piezoelectric actuator includes. The use of a piezoelectric actuator, for example many individual piezocrystals can be constructed, also allowed the realization of an electrical controllability of Schadraumventils. Depending on the design of the piezoelectric actuator, the valve body can the Schadraumventils solely by the piezoelectric actuator without other components, in particular, without a spring, in its open or be held in its closed position. This allows the Construction of a particularly robust dead space valve, which In addition, has very short switching times.

The Invention builds on the generic method in that the dead space valve is electrically actuated becomes.

On This way, the advantages and peculiarities of the invention Compressor also implemented as part of a procedure.

This is usefully further developed by a Valve body of the dead space valve via a relief bore is depressurized in each switching position of Schadraumventils.

Advantageously, it can be provided that a change in current in a coil, a movement of a solenoid is induced upon actuation of the dead space valve.

Especially it is preferred that when actuating the dead space valve a change of an electric field a change in length a piezoelectric actuator is induced.

The Invention will now be described with reference to the accompanying drawings particularly preferred embodiments exemplified.

It demonstrate:

1 a cylinder head housing of a compressor according to the prior art;

2 a cylinder head housing of a compressor according to the invention;

3 a double compressor according to the invention and

4 a system of a drive motor, a compressor according to the invention and a compressed air treatment plant.

In In the following drawings, like reference characters designate the same or similar parts.

1 shows a cylinder head housing of a compressor according to the prior art. The illustrated cylinder head housing 38 is via a connection plate 44 connected to a non-illustrated a piston chamber of the compressor comprehensive housing. The cylinder head housing 38 has an air inlet 28 and an air outlet 30 via which air is sucked in or expelled during a compressed air delivery phase of the compressor. Furthermore, in the cylinder head housing 38 a dead space 40 and a dead space valve 12 with a valve body 14 arranged, wherein the dead space valve 12 designed as a pneumatically actuated lift valve. In the illustrated switching position of Schadraumventils 12 separates the valve body 14 the dead space valve 12 the dead space 40 from a piston chamber, not shown, of the compressor, wherein the valve body 14 close to a valve seat in the connection plate 44 seated. The air is therefore through an air outlet valve during a compression phase 42 and the air outlet 30 pushed out.

2 shows a cylinder head housing of a compressor according to the invention. In contrast to 1 is that in 2 illustrated dead space valve 12 shown in its open switching state, so that the valve body 14 not on his valve seat in the connection plate 44 seated and the compressor in the dead space 40 breathes, with no air over the air intake 28 still sucked over the air outlet 30 is ejected. In contrast to 1 is that in 2 illustrated dead space valve 12 via an electrical connection 36 operable, with a coil 20 the dead space valve 12 induces a magnetic field, leaving one inside the coil 20 arranged lifting magnet 18 in the axial direction of the dead space valve 12 is moved while the dead space valve 12 opens or closes. The valve body 14 is from a guide ring 46 led, who can also perform a sealing function. About a spring 70 becomes the valve body 14 biased so that the dead space valve 12 Usually closed in the de-energized state. The valve body 14 continues to provide discharge relief 16 which ensures that there are no resulting compressive forces in the axial direction on the valve body 14 can act. The feather 70 must therefore not be designed to the valve body 14 in its closed switching position, when a maximum compression pressure is reached in the piston chamber of the compressor. Therefore, for switching the dead space valve 12 necessary force can be chosen relatively small and, for example, be about 20 N. To an efficiently working dead space valve 12 To generate, a holding current reduction can continue to be provided, which the energy consumption of Schadraumventils 12 reduced in its controlled switching state.

3 shows a double compressor according to the invention. The illustrated double compressor 10 is in a housing 32 arranged, which has a piston chamber 26 and another piston chamber 26 ' having in each case a piston 24 or another piston 24 ' periodically move up and down, with both pistons 24 . 24 ' from a common wave 34 are driven. During a compressed air delivery phase, not shown, air is supplied via an air inlet 28 and another air intake 28 ' in the piston chamber 26 or the other piston chamber 26 ' sucked in, compressed and via a common air outlet 30 pushed out. The illustrated compressor 10 further includes a dead space valve 12 , which valve body 14 having a connection between the piston chamber outside a compressed air delivery phase 26 and the other piston chamber 26 ' can produce. The illustrated Schadraumventil 12 is over the electrical connection 36 controllable, and includes a piezoelectric actuator 22 , which may be composed of many individual piezoelectric elements, for example, undergo a change in length under application of an electrical voltage, so that the valve body 14 are movable in the direction of this change in length. Since the individual Piezzoelelmente are usually crystals, the have a high pressure resistance, can be on a separate spring for biasing the valve body 14 be dispensed with in this embodiment. It is also a dead space valve 12 analogous to that in 2 illustrated embodiment conceivable, optionally for each valve body 14 either a separate coil can be provided with a solenoid or both valve body 14 are movable by a common solenoid from a common coil. In an analogous manner can also in the embodiment according to 2 a piezoelectric actuator may be provided instead of the combination of coil and solenoid.

The illustrated embodiments of the compressors according to the invention are to be understood only as examples. In particular, the valve body 14 be realized in the form of a sliding blade, as for example from the DE 39 09 531 A1 is known.

4 shows a system of a drive motor, a compressor according to the invention and a compressed air treatment plant. The illustrated drive motor 48 drives the compressor via a drive train 10 which in turn supplies compressed air via a cooling line 52 to a compressed air treatment plant 54 supplies the compressed air to a first consumer circuit 56 , a second consumer circuit 58 and a third consumer circle 60 distributed. The control of the compressor 10 and the compressed air treatment plant 54 is from a control unit 50 regulated, which via sensors 62 . 64 . 66 and 68 , which determines the control variables relevant to the control. The cooling line 52 The cooling is used by the compressor 10 produced, still highly heated compressed air to a temperature, for example, by 5 ° C is less than the permissible for efficient drying maximum temperature of about 80 ° C. In addition to the dead space valve, in this illustration only on the compressor 10 is indicated, a coupling may also be provided, wherein the control of the clutch can then be synchronized, for example, with the control of the dead space valve.

The in the above description, in the drawings and in the Claims disclosed features of the invention can both individually and in any combination for the To be essential to the realization of the invention.

10

compressor

12

Clearance volume valve

14

valve body

16

relief well

18

solenoid

20

Kitchen sink

22

Piezzoaktor

24

piston

24 '

Another piston

26

piston chamber

26 '

Another piston chamber

28

air intake

28 '

Another air intake

30

air outlet

32

casing

34

wave

36

electrical connection

38

Cylinder head housing

40

dead space

42

air release

44

connecting plate

46

guide ring

48

drive motor

50

control unit

52

cooling line

54

Compressed air treatment plant

56

first consumer circuit

58

second consumer circuit

60

third consumer circuit

62

sensor

64

sensor

66

sensor

68

sensor

70

feather

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 3909531 A1 [0003, 0027]

Claims (8)

Compressor ( 10 ) for compressed air generation, in particular for a motor vehicle, with a dead space valve ( 12 ) to relieve the compressor ( 10 ) outside a compressed air delivery phase, characterized in that the dead space valve ( 12 ) is electrically actuated. Compressor ( 10 ) according to claim 1, characterized in that a relief bore ( 14 ) in a valve body ( 16 ) of the dead space valve ( 12 ) is provided to the valve body ( 16 ) in each switching position of the dead space valve ( 12 ) to relieve. Compressor ( 10 ) according to claim 1 or 2, characterized in that the dead space valve ( 12 ) a lifting magnet ( 18 ) and a coil ( 20 ). Compressor ( 10 ) according to claim 1 or 2, characterized in that the dead space valve ( 12 ) a piezoelectric actuator ( 22 ). Method for operating a compressor ( 10 ) for generating compressed air, in particular for a motor vehicle, wherein to relieve the compressor ( 10 ) outside a compressed air delivery phase, a dead space valve ( 12 ) is opened, characterized in that the dead space valve ( 12 ) is electrically operated. Method according to claim 5, characterized in that a valve body ( 14 ) of the dead space valve ( 12 ) via a relief well ( 16 ) in each switching position of the dead space valve ( 12 ) is depressurized. A method according to claim 5 or 6, characterized in that when actuating the dead space valve ( 12 ) a current change in a coil ( 20 ) a movement of a lifting magnet ( 18 ) is induced. A method according to claim 5 or 6, characterized in that when actuating the dead space valve ( 12 ) a change of an electric field a change in length of a piezoelectric actuator ( 22 ) is induced.