Device for conserving power in a piston compressor

Abstract

A device for conserving power is provided in a piston compressor, in particular a piston-compressor for generating compressed air in a motor vehicle and having a piston delimiting a compression chamber for generating compressed air, which, originating from the ambient environment, arrives in the compression chamber for compression by way of at least one suction connection formed on a cylinder head cover and an intake valve array arranged on a valve plate. For the purpose of conserving power, a pressure-dependently acting idling device is provided for the intake valve array having a dedicated suction lamella, which can be rotated by an actuator between a working position overlapping at least one suction opening and an idling position unblocking, at least in part, the at least one suction opening. The actuator actuates the suction lamella in a coordinated manner such that in the idling position, the suction lamella unblocks the at least one suction opening in the valve plate, at least partially, while simultaneously blocking adjacent pressure valve cross-sections, at least partially, and locks the suction connection at the cylinder head cover by a slider in order to form an increased dead space in the area of the cylinder head.

Claims

1. A power conservation device in a piston compressor that generates compressed air for a vehicle, the piston compressor being equipped with a piston delimiting a compression chamber for generating compressed air which, originating from an ambient environment enters the compression chamber by way of at least one suction port formed on a cylinder head cover and an intake valve array arranged on a valve plate, the power conservation device comprising: a pressure-dependent acting idling device configured for the intake valve array, the pressure-dependent acting idling device having an associated suction lamella; and an actuator configured to rotate the suction lamella between a working position overlapping at least one suction opening and an idling position exposing, at least in part, the at least one suction opening, wherein the actuator actuates the suctions lamella in a coordinated manner such that, in the idling position, the lamella unblocks the at least one suction opening in the valve plate while simultaneously blocking adjacent pressure valve cross sections, at least partially, and blocks the at least one suction port on the cylinder head cover by way of a slider in order to form an increased dead space in a region of the cylinder head.

2. The power conservation device according to claim 1, wherein the actuator is a pneumatically controlled actuator comprising an actuating piston guided substantially parallel to a plane of the valve plate in the region of the cylinder head cover, the actuating piston being subjected to a control pressure.

3. The power conservation device according to claim 2, wherein the actuating piston is guided in a bore in the cylinder head cover.

4. The power conservation device according to claim 2, further comprising a return spring configured to bias the actuating piston into an initial position corresponding to a working position of the piston compressor when the control pressure is not acting on the actuating piston.

5. The power conservation device according to claim 2, wherein the actuating piston acts via a driver pin coupled thereto on a pivoted lever spindle, the pivoted lever spindle rotating the suction lamella between the working position and the idling position, and the actuating piston acting via the driver pin coupled thereto on the slider which closes the at least one suction port.

6. The power conservation device according to claim 3, wherein the actuating piston acts via a driver pin coupled thereto on a pivoted lever spindle, the pivoted lever spindle rotating the suction lamella between the working position and the idling position, and the actuating piston acting via the driver pin coupled thereto on the slider which closes the at least one suction port.

7. The power conservation device according to claim 1, wherein the slider that closes the at least one suction port is configured as a pivoted slider that is pivotally attached to the cylinder head cover.

8. The power conservation device according to claim 1, wherein the slider is provided with a minimum air valve in the region that closes the at least one suction port.

9. The power conservation device according to claim 8, wherein the minimum air valve is configured as a reed valve, the reed valve comprising a minimum air valve stop, formed as an aperture at an end of the slider, the aperture having a valve reed interacting therewith.

10. The power conservation device according to claim 1, wherein the at least one suction opening in the valve plate is a plurality of suction openings formed in the valve plate which are arranged in a circular ring shape and interact with the suction lamella, which is configured as a disc-shaped rotary lamella having apertures and openings.

11. The power conservation device according to claim 10, wherein the adjacent pressure valve cross sections are a plurality of pressure valve cross sections formed in the valve plate which are also arranged in a circular ring shape and interact alternately with the disc-shaped rotary lamella in a valve manner.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a schematic illustration of a piston compressor with a device for conserving power interacting therewith;

(2) FIG. 2 is a perspective view of a piston compressor cylinder head comprising a valve plate and a cylinder head cover, with an integrated device for conserving power;

(3) FIG. 3 is a perspective view of an actuator of the device for conserving power (from below), said actuator interacting with the valve plate (shown in section);

(4) FIG. 4 is a perspective view of the actuator of the device for conserving power (from above), said actuator interacting with the valve plate (shown in section);

(5) FIG. 5 is a plan view of the valve plate with the actuator for the device for conserving power, in a working position;

(6) FIG. 6 is a plan view of the valve plate with actuator for the device for conserving power, in an idling position;

(7) FIG. 7 is a section view taken along line V-V in FIG. 6, showing actuator situated within the cylinder head, in the idling position;

(8) FIG. 8 is a section view taken along line IV-IV in FIG. 5, showing actuator situated within the cylinder head, in the working position; and

(9) FIG. 9 is a schematic illustration of a twin cylinder design of a piston compressor with a device for conserving power interacting therewith.

DETAILED DESCRIPTION OF THE DRAWINGS

(10) According to FIG. 1, a piston compressor for generating compressed air essentially comprises a piston 100, which is pivotally attached to a driven crankshaft 300 by a connecting rod 200. The crankshaft 300 is mounted for rotation in a crankcase 400. The crankcase 400 contains a cylinder which, together with the piston 100, forms a compression chamber 500, which is provided at the end with a cylinder head 600shown here only schematicallyhaving a device for conserving power integrated therein.

(11) The cylinder head 600 comprises a slider 7, which operates as a 2/2-way valve, controls a suction port 1 of the piston compressor and has an integrated minimum air valve 8. The ambient air drawn in via the suction port 1 passes via the slider 7 within the cylinder head 600 into an intake chamber 18, which is formed therein and serves as a selectable dead space. In the direction of the compression chamber 500, the intake chamber 18 opens in the cylinder head 600 via a valve platenot shown specificallyinto suction openings 3 that are formed.

(12) The suction openings 3 are controlled by way of a 2/2-way valve configuration designed as a suction lamella 4 in order, in the valve position shown, which corresponds to the working position of the compressor, to prevent compressed air from flowing back into the intake chamber 18 by way of a check valve function and to expel the compressed air produced via at least one pressure bore 5, likewise formed in the valve plate, with a downstream pressure valve unit 9. More specifically, as shown here, in the absence of a control pressure S applied to the actuator for the device for conserving power, the mechanism is pushed into the working position by the spring force of a return spring 12. When there is a control pressure S applied, in the other operating position (not shown here) of the suction lamella 4, the pressure bores 5 are at least partially closed and the suction openings 3 are opened. The piston 100 then only performs compression into the now closed intake chamber 18.

(13) Any leakage losses which flow past the piston 100, for example, are compensated by the check valve function of the minimum air valve 8. The minimum air valve 8 of the slider 7 also serves to ensure a reduced delivery rate in the case of a mechanism locked in the closed position and, to this extent, provides a safety function.

(14) According to FIG. 2, the cylinder head 600 essentially comprises, in the external view, a valve plate 2, on which an intermediate plate 20 for the extended accommodation of the device for conserving power is mounted. The intermediate plate 20 is adjoined by a cylinder head cover 21. An opening for the supply of the control pressure S for the actuator, accommodated within the cylinder head 600, for the device for conserving power is arranged in the cylinder head cover 21.

(15) The suction lamella 4, which is designed as a disk-shaped rotary lamella, is arranged on the underside of the valve plate 2. Here, the suction lamella 4 is in the working position, whereinas in FIG. 1the pressure bores 5 introduced into the valve plate 2 in a circular ring arrangement are open, while suction openings 3 (not visible) concealed by the suction lamella 4 and likewise arranged in a circular ring shape in the valve plate 2 are covered here.

(16) In contrast to the external view described above, FIG. 3 illustrates a partially sectioned bottom view of the device for conserving power, omitting the intermediate plate 20 and the cylinder head cover 21 while providing a detailed illustration of the actuator for the device for conserving power in the working position.

(17) The pneumatically controlled actuator comprises an actuating piston 11, which is guided parallel to the plane of the valve plate 2 and can be subjected to the control pressure S. The actuator is in the initial position free from control pressure. In this arrangement, a driver pin 17 coupled to the actuating piston 11 acts via a pivoted lever 10 with a pivoted lever spindle 14 for actuation on the suction lamella 4 in order to switch the latter between the working position and the idling position. At the same time, the driver pin 17 of the actuating piston 11 actuates the slider 7, which serves to control the suction port 1not shown specificallywhich, being pivotally attached by way of a pivot bearing 13, is designed as a pivoting slider. In the region which closes the suction port 1, the slider 7 is provided with a minimum air valve 8a, 8b.

(18) In the working position shown, the suction lamella 4 closes the suction openings 3 formed in the valve plate 2, whereas adjacent pressure valve cross sections 5 are simultaneously exposed by way of apertures 6 in the suction lamella 4. The pressure valve cross sections 5 interact with a pressure valve unit 9a-9c, which form a check valve toward the delivery side.

(19) FIG. 4 is a plan view of the mechanism shown in FIG. 3, wherein the reference signs used above in connection with FIG. 3 apply, using the above detailed description. Here, the functional position of the actuator of the device for conserving power is thus illustrated graphically. Moreover, it can be seen that the slider 7 is provided at the end associated with the suction port 1not shown specifically herewith a minimum air intake opening 15 of the minimum air valve 8not shown specifically here.

(20) According to FIG. 5, the device for conserving power is shown in the working position, using the component designations in accordance with the preceding detailed description. Here, the suction lamella 4 mounted on the valve plate 2 conceals the suction openings 3 formed in the valve plate 2, and the adjacent pressure valve cross sections 5 of the valve plate 2 are open via the apertures 6 in the suction lamella 4. At the same time, the suction port 1 in the cylinder headnot shown specificallyis in the open position because of the slider 7 having been pivoted away therefrom. This working position is reached in the state of the actuating piston 11 in which it is free from control pressure, the piston being pushed into the initial position by a return spring 12.

(21) In FIG. 6, in contrast, the actuating piston 11 is subject to control pressure, with the result that the device for conserving power is in the idling position. Here, the suction openings 3 in the valve plate 2 are opened by openings 16 in the suction lamella 4, whereas the pressure valve cross sections 5 are closed since they do not coincide with the corresponding apertures 6 in the suction lamella 4. At the same time, the suction port 1 in the cylinder headnot shown specifically hereis closed by the end of the slider 7, with the result that air can flow only via the minimum air valve 8, through the minimum air intake opening 15, into the intake chamber 18not shown here.

(22) FIG. 7 is a sectioned view taken along line V-V in FIG. 6 and illustrates the device for conserving power in the idling position. As is evident, the actuating piston 11 of the actuator for the device for conserving power is guided in a corresponding bore 22 in the cylinder head cover 21 to form a piston-cylinder unit, which is subjected to the control pressure. The driver pin 17 arranged on the outer circumference of the actuating piston 11 extends through a slotted opening in the cylinder head cover 21 into the slider 7, which is designed as a pivoted lever.

(23) The driver pin 17 is furthermore used to actuate the pivoted lever 10, which actuates the suction lamella 4 via the pivoted lever spindle 14. The pressure valve unit, which interacts with the pressure valve cross sections 5 in the valve plate 2, comprises a pressure valve stop 9a, a pressure valve spring 9b and a pressure valve reed 9c, which is here arranged in the region of the intermediate plate 20 of the cylinder head. In respect of the remaining reference signs, the above detailed description otherwise applies.

(24) FIG. 8 is a sectioned view taken along line IV-IV in FIG. 4 and illustrates the device for conserving power in the working position. Here too, in respect of the reference signs used, the above detailed description otherwise applies.

(25) FIG. 9 shows a twin-cylinder design of a piston compressor, in which the same intake chamber 18 is used by both cylinders. There is only one slider 7 since there is only one suction port 1 in this embodiment too. Each compression chamber 500 and 500a is assigned a dedicated pivotable suction lamella 4 and 4a respectively. In the idling phase, one piston 100 then displaces the air via the intake chamber 18 into the other compression chamber 500a, which, with a 180 phase displacement, has a downward-moving piston 100a at precisely this moment, i.e. is exerting suction. Owing to the large open cross section of the suction openings 3, 3a and the possibility of free flow through the intake chamber 18, only very low throttling losses occur. Here too, the cylinder pressure can be configured in such a way, by means of the size of the exposed suction passage cross sections, that sufficient backpressure remains to avoid oil transfer.

LIST OF REFERENCE SIGNS

(26) 1 suction port 2 valve plate 3 suction opening 4 suction lamella 5 pressure valve cross section 6 aperture 7 slider 8 minimum air valve 9 pressure valve unit 10 pivoted lever 11 actuating piston 12 return spring 13 pivot bearing 14 pivoted lever spindle 15 minimum air intake opening 16 opening 17 driver pin 18 intake chamber 19 pressure chamber (delivery side) 20 intermediate plate 21 cylinder head cover 22 bore 100 piston 200 connecting rod 300 crankshaft 400 crankcase 500 compression chamber 600 cylinder head S control pressure

(27) The foregoing disclosure has been set forth merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof.