WO2011057843A1

WO2011057843A1 - Air conditioning compressor for a vehicle and vehicle

Info

Publication number: WO2011057843A1
Application number: PCT/EP2010/063859
Authority: WO
Inventors: Bjoern Noack
Original assignee: Robert Bosch Gmbh
Priority date: 2009-11-12
Filing date: 2010-09-21
Publication date: 2011-05-19
Also published as: EP2499366A1; US20120315170A1; DE102009046649A1; CN102667155A

Abstract

The invention relates to an air conditioning compressor (1) for a vehicle (24), in particular a motor vehicle (25), having a compression chamber (18) having an inlet (7) for a cooling medium to be compressed and an outlet (8) for the compressed cooling medium, wherein a wall of the compression chamber (18) is formed at least in sections by a translationally displaceable piston (3). According to the invention, the end of the piston (3) facing away from the compression chamber forms at least one wall region of a control pressure chamber (19). The invention further relates to a vehicle having an air conditioning apparatus.

Description

description

title

Air conditioning compressor for a vehicle, vehicle

The invention relates to an air conditioning compressor for a vehicle, in particular motor vehicle, having a compression chamber which has an inlet for a cooling medium to be compressed and a drain for the compressed cooling medium, wherein a wall of the compression chamber is at least partially formed by a translationally displaceable piston.

Furthermore, the invention relates to a vehicle, in particular a motor vehicle, with a drive device and an air conditioning compressor having an air conditioning compressor.

State of the art

Air compressors and vehicles of the type discussed here are known from the prior art. In order to increase the comfort in vehicles, in particular with regard to the vehicle interior temperature, it is known to provide air conditioning devices which provide for a cooling of the interior. For this purpose, such air conditioning devices have at least one air conditioning compressor, which ensures the air conditioning enabling compression of a gas and / or vapor refrigerant in a cycle of the air conditioning device. In this case, air compressors are known, which are based on the principle of a piston pump and to have a translationally displaceable piston, which is used for compressing a gas and / or vaporous cooling medium located in a compression chamber. The piston forms at least one wall region of the compression chamber, so that the volume of the compression chamber is reduced by displacing the piston and the cooling medium located therein is compressed. Known air conditioning compressors are designed such that they are mechanically driven by a belt or chain drive of a crankshaft of an internal combustion engine. As a result, the drive device of such a vehicle, however, energy is taken, which lacks the vehicle to feed and beyond also in the pollutant emissions (C0 ₂ emissions) noticeable.

Disclosure of the invention

The air conditioning compressor according to the invention is driven to reduce without the performance of a drive device and requires, compared to known air conditioning compressors, a relatively small space. This air compressor is characterized by the features of the current claim 1. Accordingly, the air conditioning compressor is designed such that the piston at its end remote from the compression chamber forms at least one wall region of a control pressure chamber of the air conditioning compressor. Thus, an air-conditioning compressor is provided which has an axially displaceable piston which cooperates with the compression chamber on one side or with one end and with the control pressure chamber on the other side or with the other end. Due to the pressure difference between the control pressure chamber and the compression chamber, the piston is displaced axially. The pressure in the control pressure chamber can be controlled, as the name implies, so that a compression process in the compression chamber is adjustable by increasing and decreasing the pressure in the control pressure chamber. By increasing the pressure in the control chamber, the piston is moved into the compression chamber or the volume of the compression chamber is reduced. By reducing the pressure in the control pressure chamber, the piston is moved out of the compression chamber, so that in the compression chamber cooling medium nachströmt and optionally sucked. Thus, the air conditioning compressor according to the invention is not operated mechanically, but preferably hydraulically. In this case, a connection of the air conditioning compressor to an existing hydraulic system can take place. The advantageous air conditioning compressor thus does not remove any energy required for driving / feeding a drive device of a motor vehicle. Advantageously, the inlet and / or the outlet of the compression chamber are arranged or formed on a piston region remote from the end of the compression chamber. This ensures that the largest possible volume of the compression chamber for conveying and compressing cooling medium is available. In the simplest case, the inlet and / or the drain are formed as a bore / s in a housing forming the compression chamber.

Preferably, a check valve is assigned to the inlet and / or the drain. The check valves are designed and / or arranged such that at elevated pressure in the compression chamber closes the inlet associated check valve and the flow associated check valve opens so that the compressed in the compression chamber cooling medium is expelled under high pressure from the compression chamber when the piston moves into the compression chamber. If the piston moves in the opposite direction due to a lower pressure in the control pressure chamber, then the non-return valve assigned to the outlet closes the previously released flow cross-section and the check valve assigned to the inlet releases a flow cross-section so that gas and / or vaporous cooling medium flow into the compression chamber can. The check valves thus ensure a pressure build-up in the compression chamber and a separation between a high-pressure section and a low-pressure section of the cooling medium leading cooling circuit.

Conveniently, the piston is associated with at least one return spring. Here, the rear part is to be understood as the displacement of the piston out of the compression chamber. In other words, the return spring serves to increase the volume of the compression chamber by moving the piston. This has the advantage that the (sub) pressure to be set in the control pressure chamber for displacing the piston in the direction of the control pressure chamber can be reduced. The return spring permanently ensures safe operation of the air conditioning compressor by applying a spring force to the piston in the direction of the control pressure chamber. Furthermore, it is provided that the return spring is designed as a helical spring and arranged in the compression chamber. The return spring thus acts as a compression spring and is optionally biased between the facing to the compression chamber end face of the piston and a said end face of the piston opposite housing wall of the compression chamber.

It is further provided that the control pressure chamber in a hydraulic circuit, in particular a drive device of a motor vehicle is einbindbar. For this purpose, the control pressure chamber corresponding connections, which allow easy integration into such a hydraulic circuit. Conveniently, material and material thickness of the control pressure chamber forming housing are selected according to the high pressure requirements. Among other things, this leads to the fact that the control pressure chamber is designed as a hydraulic chamber and the air compressor as a hydraulically controlled air conditioning compressor.

For this purpose, the control pressure chamber preferably has a high-pressure connection and a low-pressure connection for the hydraulic circuit. Due to the high-pressure connection, hydraulic fluid is fed into the control pressure chamber so that the piston is displaced into the compression chamber. For this purpose, a pressure must expediently be present at the high-pressure connection, which is sufficient to displace the piston for compressing the gaseous and / or vaporous cooling medium located in the compression chamber.

Finally, it is provided that the low-pressure and / or high-pressure port is assigned in each case a switchable valve. As a result, it is not only possible to set the operating frequency of the air conditioning compressor in a simple manner, but also the compression pressure acting in the compression chamber. By opening the switchable valve associated with the high pressure port, hydraulic fluid flows under high pressure into the control pressure chamber. The low pressure valve is suitably closed. Due to the high pressure of the hydraulic fluid, the piston is displaced into the compression chamber and the cooling medium located there is compressed. At the latest when the pressure in the compression chamber corresponds to the pressure in the control chamber which acts on the piston-that is to say including the spring force of the return spring- the valve associated with the high pressure port is closed and the valve associated with the low pressure is opened so that the hydraulic fluid flows out of the control pressure chamber and is reset by the pressure loss in the control pressure chamber of the piston.

The vehicle according to the invention is characterized by an air conditioning compressor, as described above. Conveniently, the air compressor is incorporated in a hydraulic circuit of the drive device, wherein advantageously the low pressure port is connected to a low pressure section of the hydraulic circuit and the high pressure port to a high pressure section of the hydraulic circuit. By appropriate actuation of the switchable valves, the cooling capacity of the air conditioning device can now be controlled or regulated in a simple manner. Since a mechanical drive of the air conditioning compressor is omitted, the drive device is not taken for the energy required for the feed, so on the one hand, the performance of the drive device can be fully used for propulsion and on the other pollutant emissions are reduced.

In the following, the invention will be explained in more detail with reference to the drawing. Show this

Figure 1 shows an air compressor in a simplified sectional view and

2 shows a vehicle with an air conditioning device.

FIG. 1 shows, in a simplified representation, a longitudinal section through an air-conditioning compressor 1, for an air-conditioning device, in particular of a vehicle or motor vehicle. The air conditioning compressor 1 has a housing 2, which is preferably at least substantially kreiszylinderför- mig. In the housing 2, a piston 3 is arranged axially displaceable - that is, in the direction of its longitudinal axis. On its outer shell surface, two sealing elements 4 in the form of O-rings 5 are arranged on the piston 3, sealing the gap between the piston 3 and the inside of the housing 2 in a sealing manner. At the same time, the sealing elements 4 can also serve to guide the piston 3 in the housing 2. Conveniently, however, the guide further, not shown here, for example, in Form of guide webs and / or grooves provided which serve in particular to minimize friction when moving the piston 3 in the housing 2 and prevent jamming tilting of the piston 3 in the housing 2.

The housing 2 of the air conditioning compressor 1 further comprises in a first region 6 an inlet 7 and a drain 8, which are each formed in the jacket wall of the housing 2. In the present case, the inlet 7 and the outlet 8 are aligned substantially radially with respect to the housing 2. The inlet 7 has a first check valve 9 and the outlet 8 a second check valve 10. The design and function of check valves is well known, so that it should not be discussed in detail here on the exact design of the check valves 9 and 10.

At its end region 11 opposite the end region 6, the housing 2 of the air conditioning compressor 1 has a high-pressure connection 12 and a low-pressure connection 13, which in the present case are likewise formed in the jacket wall of the housing 2. The high-pressure port 12 and the low-pressure port 13 are each assigned a switchable valve 14 and 15, respectively. By means of the connections 12 and 13, the air conditioning compressor 1 can be integrated in the hydraulic circuit of a drive device of the above-mentioned motor vehicle. By means of the switchable valves 14 and 15 can be closed or release at the respective port 12,13 a corresponding flow cross-section. Optionally, the flow cross sections are infinitely adjustable. The check valves 9, 10 and / or the valves 14, 15 may each be formed at least in regions integrally with the housing 2 or as separate attachments.

The displaceably mounted in the housing 2 piston 3, which is sealed against the inner wall of the housing 2 by means of the sealing elements 4, divides the housing 2 into two chambers 16 and 17. The chamber on the inlet 7 and the outlet 8 having side of the housing 2 forms a compression chamber 18 for a cooling medium of the air conditioning device of the motor vehicle having the air conditioning compressor 1. The chamber 17 located on the opposite side of the piston 3 forms together with the piston Control pressure chamber 19 which controls the movement of the piston 3 by switching the valves 14 and 15 substantially.

In the compression chamber 18, a return spring 20, which is presently designed as a helical spring 21, is advantageously arranged. The return spring 20 acts together with the free end face of the piston 3 and the opposite end of the piston, closed end side of the housing 2 in the end region 6. Optionally, the return spring 20 is arranged under bias between the piston 3 and the housing 2, so that it always acts on the piston 3 in the direction of the control pressure chamber 19 with a spring force. So that the piston 3 is not completely introduced into the control pressure chamber 19, stops are expediently provided on the housing inner wall in this case, which prevent over-penetration of the piston 3 into the control pressure chamber 19. The control pressure chamber 19 and the compression chamber 18 are thus each formed by the walls of the housing 2 and by a respective free end face of the piston 3.

In the following, the function of the air conditioning compressor 1 will be explained: The inlet 7 is fed to a gas and / or vaporous cooling medium of the cooling circuit of the air conditioning unit to be compressed. The check valves 9 and 10 ensure that the cooling medium to be compressed, although in the compression chamber 18, but not out of it can flow out again, provided that the pressure in the compression chamber does not exceed a critical pressure. For a compression process, first the valve 14 is opened, so that hydraulic fluid from the hydraulic circuit of the drive device flows into the control pressure chamber 19, while the valve 15 is closed. As a result, pressure builds up in the control pressure chamber 19, which ensures that the piston 3 moves in the direction of the compression chamber 16 or in the direction of the end region 6, as indicated by an arrow 22. The return spring 20 is thereby tensioned and compressed in the compression chamber 16 located gas and / or vapor cooling medium, wherein the pressure in the compression chamber 18 is increased.

The remaining liquid phase is forced against the check valve 10 of the outlet 8, whereby this is opened when the critical pressure is reached and the now liquid, compressed cooling medium is discharged through the outlet e into the cooling circuit. at least as long as the pressure in the control pressure chamber is higher than the pressure in the compression chamber 18. At the latest when a pressure equalization between the compression chamber 18 and the control pressure chamber 19 has taken place, the valve 14 of the high pressure port 12 is closed and the valve 15 of the Low pressure port 13 is opened. This relaxes the hydraulic fluid in the control pressure chamber 19 and flows through the valve 15 and the low pressure port 13 back into the hydraulic circuit of the drive device. The return spring 20 and the now existing pressure difference between the control pressure chamber 19 and the compression chamber 18 ensure that the piston 3 is moved back, as indicated by an arrow 23, to its original position. In this case, the remaining in the compression chamber 18 refrigerant evaporates again, and by the resulting suction is additionally sucked via the check valve 9 gaseous and / or vaporous cooling medium in the compression chamber 18, while the check valve 10 is closed again. Here begins the process described above to repeat. By adjusting the valves 14 and 15, the speed of the piston 3 and the path of movement of the piston 3 can be influenced.

2 shows a simplified representation of an advantageous embodiment of a vehicle 24, which is designed as a motor vehicle 25 and to a drive device 26 includes, which includes an internal combustion engine and / or one or more electrical machines. The drive device 26 is associated with a hydraulic unit 27, which has, inter alia, means for generating a pressure for a liquid hydraulic medium. The hydraulic unit is connected via a first hydraulic circuit 28 with components of the drive device 26 and via a second hydraulic circuit 29 with the above-described air conditioning compressor 1. Here, a high pressure portion of the hydraulic circuit 29 is connected to the high pressure port 12 of the control pressure chamber 19 and a low pressure portion of the hydraulic circuit 29 is connected to the low pressure port 13. The compression chamber 18 is integrated with its inlet 7 and its outlet 8 in a cooling circuit 30 of an air conditioning device 31 and thus part of the air conditioning device 31st In the cooling circuit 30, a capacitor 32 is further incorporated, which is flowed through by ambient air, optionally with the aid of a blower 33, such as indicated by arrows 34. The air conditioning device 31 advantageously further comprises - not shown here - a sump for the cooling medium, a temperature-controlled switch for switching on and off the air conditioning compressor 1, in particular in the form of a two-point controller, a switch associated with the temperature sensor, an expansion valve and an evaporator with switchable Evaporator fan to provide the cooling capacity.

Overall, the air compressor 1 thus provides a particularly simple way a compression option for the cooling medium without a drive device 26 of the motor vehicle 25 power must be withdrawn. In addition, the present air compressor 1 offers a particularly compact and cost-effective design. In addition, air conditioning is easily possible even during a motor stall, which in particular in modern hybrid drive concepts, which have as drive components in addition to a classic internal combustion engine, such as gasoline or diesel engine, one or more electrical machines.

In order to prevent contamination between the hydraulic fluid and the cooling medium in the air-conditioning compressor 1, in another exemplary embodiment, which is not shown here, an "atmospheric intermediate part" is provided between the compression chamber 18 and the control pressure chamber 19. For example, in the housing 2 one or more It is also conceivable to provide the compression chamber 18 and the control pressure chamber 19 in different, substantially separate housing parts, while a partial piston is displaceably mounted in each of the housing parts, and the partial pistons in turn via a corresponding mechanism connected to each other.

Claims

claims

1 . An air-conditioning compressor (1) for a vehicle (24), in particular motor vehicle (25), having a compression chamber (18) which has an inlet (7) for a cooling medium to be compressed and a discharge (8) for the compressed cooling medium, wherein a wall the compression chamber (18) is at least partially formed by a translationally displaceable piston (3), characterized in that the piston (3) at its end facing away from the compression chamber forms at least one wall region of a control pressure chamber (19).

2. Air compressor according to claim 1, characterized in that the inlet (7) and / or the outlet (9) on a piston (3) far end region (6) of the compression chamber (18) are arranged / formed.

3. Air compressor according to one of the preceding claims, characterized in that the inlet (7) and / or the outlet (8) is associated with a respective check valve (9,10).

4. Air compressor according to one of the preceding claims, characterized in that the piston (3) is assigned at least one return spring (20).

5. Air compressor according to one of the preceding claims, characterized in that the return spring (20) as a helical spring (21) and arranged in the compression chamber (18) is arranged.

6. Air compressor according to one of the preceding claims, characterized in that the control pressure chamber (19) in a hydraulic circuit (29), in particular a drive device (26) of a motor vehicle (25) is einbindbar.

7. Air compressor according to one of the preceding claims, characterized in that the control pressure chamber (19) has a high-pressure connection (12) and a low-pressure connection (13) for the hydraulic circuit (29).

8. Air compressor according to one of the preceding claims, characterized in that the low-pressure and / or the high-pressure port (12,13) is assigned in each case a switchable valve (14,15).

9. vehicle (24), in particular motor vehicle (25), with a drive device (26) and an air conditioning compressor (1) having air conditioning device (31), characterized in that the air conditioning compressor (1) is designed according to one or more of the preceding claims ,

10. Vehicle according to claim 9, characterized in that the control pressure chamber (19) in a hydraulic circuit (29) of the drive device (26) is integrated.