EP3440355B1 - Compressor having an energy saving apparatus, and method for relieving the compressor - Google Patents

Description

The present invention relates to a compressor for generating compressed air for a commercial vehicle and a method for relieving a compressor, the compressor having a housing with a piston chamber and a clearance, and a valve device for separating the clearance from the piston area.

Auxiliary units of commercial vehicles such as rail vehicles, trucks or buses are often operated with compressed air, which is usually supplied by a compressed air system operated in the vehicle. Compressed air systems of this type work with compressors, which are usually driven directly by the drive unit of the vehicle, such as an internal combustion engine. The compressor is often driven as long as the drive unit of the commercial vehicle is in operation. At times when there is no air requirement or the compressed air storage of the commercial vehicle is completely filled, the compressor can usually be relieved by means of an energy saving device in order to reduce the energy consumption of the compressed air system.

Various energy saving devices are known. Such devices are often activated by means of a pneumatic pressure signal from an air treatment unit arranged downstream. What such devices have in common is that, in the activated state, they permanently open the compression chamber of the compressor to a harmful chamber in the cylinder head, which is specially designed for this purpose, and / or to the air inlet in order to increase the thermodynamic work which is carried out during a crank revolution to reduce.

From the published application DE 10 2008 005 435 A1 an energy-saving device is known which has a valve element which moves to relieve the pressure on the compressor in the direction of the compression chamber of the compressor. The proposed design has a support plate arranged on the valve element for absorbing the reaction forces of a return spring. To assemble this To enable the support plate, however, a two-part valve element is required. In addition, the support plate disrupts the air flow between the piston chamber and the harmful chamber and thus causes energy losses when the energy saving device is activated. Another disadvantage of this known energy-saving device is that an opening in the cylinder head of the compressor is required for mounting the two-part valve element. After the valve device has been installed, this opening is to be closed, for example by means of a closure plate, and appropriately sealed. This is complex and expensive and also represents a quality risk because of the risk of leakage.

Other compressors for generating compressed air for a commercial vehicle are known, for example, from US Pat JP H10 9141 A (which discloses the features of the preamble of claim 1) and the DE 37 83 092 T2 ,

The present invention is therefore based on the object of providing an improved compressor and an improved method for relieving a compressor for generating compressed air for a commercial vehicle.

This is achieved according to the invention by the teaching of the independent claims. Advantageous refinements and developments of the invention are the subject of the dependent claims.

To achieve the object, a compressor for generating compressed air for a commercial vehicle is proposed, which has a housing with a piston chamber in a crankcase and a clearance, which is at least partially formed in a cylinder head of the compressor. The compressor also has a valve device with a valve element which has an actuating section and a shut-off body for separating the harmful space from the piston chamber, the shut-off body for opening the valve device being liftable from a valve seat formed on a valve plate in the direction of the piston chamber. The valve element is formed in one piece with the actuating section and the valve plate is designed such that the valve element with the actuating section through the valve plate in the direction of Cylinder head can be guided until the shut-off body on the valve seat and the actuating section are arranged in the cylinder head.

The housing of the compressor has a crankcase, in which at least one piston chamber extends with a piston moving therein, and a valve plate, which is arranged opposite the at least one piston chamber on the crankcase, a cylinder head in which at least one valve element of at least one valve device is mounted and, in some embodiments, a holding plate arranged in the area between the valve plate and the cylinder head, through which the at least one valve element extends. A damaged space extends at least partially in the area of the cylinder head.

The at least one valve element has an actuating section arranged in the cylinder head and a shut-off body arranged in the valve plate for separating the harmful chamber from the piston chamber. The shut-off body sits in the closed state of the valve device - in particular during the generation of compressed air - on a valve seat arranged in the valve plate, from which the shut-off body can be lifted off by an axial movement of the valve element in the direction of the piston chamber in order to prevent the air from flowing into the harmful space enable. Compression of the air is largely avoided by the volume of the piston chamber which is increased in this way, as a result of which the thermodynamic work of the compressor is greatly reduced. This relieves the load on the compressor and reduces the power output.

The valve element according to the invention has an actuating section which is formed in one piece with it and which has an active device which can be acted upon by energy for causing the valve element to move along its longitudinal axis. The valve element can thus be moved axially in the direction of the piston chamber by means of the active device of the actuating section. An additional actuating element known from the prior art, which is in particular fixedly mounted on the valve element in particular through an opening in the cylinder head and within the cylinder head, can thus be dispensed with. Within the scope of the invention a valve element is considered to be in one piece, which already forms a fixed unit before assembly on the compressor, which is not separated for the assembly of the valve element. Such a valve element has an active device which is formed in one piece with the valve element and is used to actuate the valve device. For example, for manufacturing reasons or if different materials are used, it may be necessary to construct the valve element from two or more components, which are in particular firmly or non-positively connected to one another and form a unit that is already present in the compressor before the valve element is installed , so that the valve element is installed as "one part" in the compressor. In this case, the valve element can form a unit from, for example, welded, soldered, pressed, screwed or otherwise firmly connected components, so that it is considered as a one-piece valve element in the sense of the invention described here.

The valve plate and a holding plate of the compressor provided according to the invention are designed such that the valve element can be guided in the direction of the cylinder head during its assembly, in particular through or in openings or recesses around the valve element arranged in the valve plate and / or in the holding plate to bring it into its functional position, that is, until the shut-off body of the valve element is arranged on the valve seat and the actuating section is arranged in the cylinder head. In this functional position, the valve element extends through the valve plate and through the holding plate, in particular perpendicular to the direction of the maximum extension of the valve plate or holding plate.

The holding plate can be designed as a so-called intermediate plate, which is arranged between the valve plate and the cylinder head and extends over a part or over the entire cross section of the compressor in this area. In this case, the holding plate is suitably designed to seal against leakage of the compressor. In another embodiment, the holding plate can also be arranged, for example, in a suitable recess, in particular between the valve plate and cylinder head of the compressor, or in another way in the region between the valve plate and cylinder head, in particular to Record valve element and, if necessary, provide other suitable devices for the function of the valve device.

The described design of the compressor, in particular the valve element, the valve plate and the holding plate, enables a one-piece design of the valve element without requiring an assembly opening in the cylinder head for the assembly of components of a multi-part valve element, in particular after the cylinder head has been put on, thereby closing and sealing one such an opening after installation of the valve element is omitted. Likewise, the risk of leakage of the seal is eliminated in the proposed design.

In the compressor according to the invention, a holding plate is arranged in the area between the valve plate and the cylinder head, through which the valve element extends after it has been installed. To make this possible, the holding plate has a holding plate recess, the cross section of which has at least the cross section of the valve element in a region between the shut-off body and the actuating section. The holding plate recess is laterally open, so that the valve element can be received by lateral insertion in the holding plate recess. Due to the fact that the cross section of the holding plate recess is in particular slightly larger than the cross section of the valve element in the area which is received in the holding plate recess, the holding plate can be used as a bearing element for a or in the area of the valve element, in particular in the area around the valve element. serve in the region of the cross section of the valve element arranged on the holding plate valve closing device.

In order to enable insertion and guiding of the valve element together with the actuating section through the valve plate and also through or to the holding plate, it is expedient if an opening or a space is provided in the holding plate or adjacent thereto, the cross section of which is at least as large as a Possibly inclined cross section of the actuating element in the area of its greatest extent, so that the actuating element can be suitably moved for its assembly in the cylinder head. One way of assembling the valve element is to compare it to the later one Functional position inclined with the fastening section ahead of the holding plate recess to lead through the valve plate into the cylinder head and tilt the valve element as soon as the shut-off body reaches the valve seat into the functional position. When the valve element is tilted, the valve element then enters the holding plate recess. In this embodiment, it is advantageous that the valve element together with the actuating section can be guided into the cylinder head by an assembly process. After the cylinder head has been put on, the valve element and the actuating section are then mounted in the cylinder head so as to be movable in the longitudinal direction and thus already in the functional direction.

In one embodiment of the compressor, the valve element is movably mounted in a valve chamber in the cylinder head along the axis of the valve element, the valve chamber being delimited by the cylinder head on the side facing away from the piston chamber. Since the valve element reaches the valve chamber from the side facing the piston chamber when the cylinder head is installed, an installation opening in the cylinder head of the compressor, in particular on the side facing away from the piston chamber, can be dispensed with. The time-consuming closing of the assembly opening is thus eliminated, as is the associated risk of leakage.

In an alternative design, the compressor is designed in such a way that the valve chamber on the side facing away from the piston chamber is delimited by an intermediate plate arranged in the cylinder head. Even with such a design, there is no need for a mounting opening, which is particularly difficult to seal, on the side facing away from the piston chamber in the cylinder head, as a result of which there is also no elaborate closing of the mounting opening as well as the associated risk of leakage.

In one embodiment of the compressor, a valve closing device is arranged on the valve element, by means of which the shut-off body for closing the valve device can be moved in the opposite direction to the piston chamber to the valve seat. The valve closing device can be supported on the valve plate or a holding plate provided for this purpose. For example, such valve closing devices are at least one suitable spring, for example one or more spiral springs, which are designed in particular as a compression spring, disc springs or other suitable devices.

The valve closing device is supported directly on the valve element, for example on at least one projection formed thereon, on which the valve closing device can be arranged or fastened by means of suitable devices during assembly on the valve element. It is also possible to support the valve closing device on at least one additional holding element, such as, for example, in a form-fitting manner, for example on a locking washer connected to the valve element after the valve closing device has been arranged, or on another, in particular subsequently, for example on a projection, in a groove, in a bore or the like of the valve element suitable securing elements can be arranged.

In an embodiment of the holding plate in which the valve element with its actuating section can be guided through a holding plate opening or adjacent to the holding plate recess, the holding plate recess in the holding plate is designed such that a valve closing device is supported on a sufficiently large area of the holding plate after mounting on the valve element can. In particular, configurations are available here in which the valve element with the actuating element, which usually has a larger diameter than the region of the valve element, which moves in the region of the holding plate when the compressor is in operation and during operation of the compressor, through the valve plate in one region is guided, which is arranged somewhat offset from the later operating location of the valve element. The valve element is only moved into the operating position when sections with a larger diameter, such as in particular the actuating section, have already passed the holding plate. In this way, sufficient support of the valve closing device, which is mounted on the valve element after the valve element has been passed through the valve and holding plate, can be achieved on the holding plate. An additional support plate, which is known from the prior art and is arranged directly on the valve plate and supports the valve closing device in the direction of the piston chamber, is not necessary in the proposed design.

In a further development, the valve closing device is a spring, in particular a spiral spring, which has a conical shape, for example. With this design, the spring in the support area on the valve or holding plate has a larger diameter than on the support on the valve element, as a result of which a larger supporting surface on the valve or holding plate is possible. On the other hand, this spring can be designed in such a way that it surrounds the valve element in a sufficiently tight manner adjacent to a protrusion molded onto it or retrofitted.

In one embodiment, the smallest diameter of a conical spring is smaller than the diameter of the section of the valve element against which the spring is supported and over which the spring is to be guided during assembly. With such a design of the spring and valve element, suitable assembly devices can be used during assembly, by means of which the windings of the spring, which have a diameter that is smaller than the diameter of the section of the valve element, against which the spring is supported after assembly, expanded and managed through this section. Such designs of the spring and valve element enable the mounting of a valve closing device designed in the form of a spring on a one-piece valve element.

In a further development, the shut-off body of the valve element can be lifted from the valve seat in the direction of the piston chamber by directly applying pneumatic, electromagnetic or mechanical energy to the active device of the actuating section of the valve element. Here, the actuating section - as well as the corresponding valve chamber in the cylinder head and possibly other additionally required devices - is designed in such a way that applying a suitable energy to the active device leads to actuation of the valve element in the direction of the piston chamber in order to open the valve device. For example, when using pneumatic energy, the valve chamber is designed as a piston chamber, in which compressed air can flow to actuate the valve element. The actuating section of the valve element has the shape of a pneumatic piston which is in particular designed to seal against the valve chamber in the cylinder head, and correspondingly moves axially towards the piston chamber when compressed air is applied to the valve chamber due to the pneumatic energy. This creates a connection between the piston chamber and the harmful chamber, which relieves the compressor.

When using electromagnetic energy, a suitable electromagnet, for example, is arranged on the valve chamber, with which a magnetic field can be induced in the valve chamber, which applies an axial force to a conductor arranged therein. The actuating section of the valve element is mounted in the valve chamber and has a conductor as an active device. Applying an electromagnetic field to the active device of the actuating section leads to an axial movement of the actuating section and thus of the valve element, as a result of which the valve device can be opened and thus a connection can be established between the piston chamber and the harmful chamber. In this embodiment, the active device as an element of the actuating section can be made of a different material than the other sections of the valve device. However, since the valve element also forms a unit in this case, which is already present before assembly on the compressor, such a valve element, as already stated above, is also considered to be in one piece within the scope of the invention described here.

In another embodiment, the actuating section has a shape as an active device, via which mechanical energy can be transferred to the actuating section in the direction of the actuating axis by means of a positive connection. The actuating section in the cylinder head can be in contact with a device which transfers mechanical energy to the active device of the actuating section in order to move the shut-off body of the valve element from the valve seat in the direction of the piston chamber. In a further embodiment, the actuating section, as an active device, has a projection in the form of a shoulder, via which mechanical energy can be transmitted to the actuating section by means of a positive connection. In another embodiment, the actuating section has a spindle groove as the active device. In this embodiment, mechanical energy can be directed towards the valve element via a drive element connected to a spindle drive the actuation axis are transmitted. Since the valve element is also formed in one piece with the actuating element in these designs, such a valve element is also considered in one piece within the scope of the invention described here.

In a further development, the shut-off body does not extend beyond the valve plate into the piston chamber when the valve element is open. The upper reversal point of the piston can be provided in the piston chamber in the immediate vicinity of the valve plate. As a result, a high compression performance is possible without there being a risk of the piston colliding with the shut-off body, which necessitates a recess for immersing the shut-off body when the compressor is unloaded.

In another development, the compressor has at least one further valve device with at least one further valve element and at least one further piston chamber. Depending on the power requirement and embodiment, compressors with two or more cylinders can also be used in addition to single-cylinder compressors, it being possible to provide a further valve device with at least one further valve element and at least one further clearance to relieve the compressor.

In a further embodiment, the piston chamber and the at least one further piston chamber are connected to one another via at least one damage chamber when the valve device and the at least one further valve device are open. By connecting the piston chamber to another piston chamber via the dead space, pressure build-up during a relief phase of the compressor is largely prevented, since the air can be pumped back and forth between the piston chamber and the further piston chamber. Alternatively, a further damage chamber can be provided, which can be connected to the further piston chamber via the further valve device. Another harmful space enables the piston chambers to be relieved independently of one another. In particular, one or more harmful spaces can be provided, which are coupled to the atmosphere via the intake line of the compressor. Coupling with the atmosphere enables a further reduction in the peak pressures that occur during unloaded operation, which further reduces the energy consumption of the compressor.

Furthermore, the invention relates to a commercial vehicle with a compressor according to the invention.

The invention further relates to a method for relieving a compressor for generating compressed air for a commercial vehicle according to claim 10, having a compressor which has a housing with a piston chamber in a crankcase and a damage chamber which is at least partially formed in a cylinder head. The compressor also has a valve device with a valve element which is formed in one piece with an actuating section and a shut-off body for separating the harmful space from the piston chamber, the shut-off body for opening the valve device being liftable in the direction of the piston chamber from a valve seat, in particular formed on a valve plate , The method has the method step that, when the compressor is operating, the valve device is opened by directly applying pneumatic, electromagnetic or mechanical energy to the actuating section of the valve element in order to relieve the pressure on the compressor.

The elements of the compressor described with the method are understood in the sense of the above description. The method can be carried out with a device of the type described above and the developments described above.

An advantage of the described method is that by opening the valve device, the air flowing into the piston chamber can at least partially flow out into at least one harmful chamber during the compression phase of the piston, which reduces the compression of the air in the piston chamber and this during the suction phase of the piston can flow back into the compression space, whereby thermodynamic work can be recovered. This relieves the load on the compressor and reduces its energy consumption. Because the valve element is formed in one piece with the actuating element, it is not necessary to mount an especially additional actuating element through an opening of the cylinder head on the valve element.

Fig. 1

zeigt eine Schnittansicht durch einen beispielhaften erfindungsgemäßen Kompressor.

Fig. 2a und Fig. 2b

zeigen jeweils eine dreidimensionale Ansicht von zwei beispielhaften erfindungsgemäßen Halteplatten.

Figuren 3a bis 3d

zeigen eine Abfolge einer beispielhaften erfindungsgemäßen Montage eines Ventilelements an Ventil- und Halteplatte.

Figuren 4a bis 4c

zeigen eine Abfolge einer beispielhaften erfindungsgemäßen Montage einer Feder am Ventilelement.

Fig. 4d

zeigt eine Darstellung der beispielhaften erfindungsgemäßen Feder aus den Figuren 4a bis 4c.

Fig. 5

zeigt eine weitere beispielhafte erfindungsgemäße Ventileinrichtung mit unterschiedlicher Feder sowie Sicherungseinrichtung am Ventilelement.

Fig. 6

zeigt eine weitere beispielhafte erfindungsgemäße Ventileinrichtung, welche mittels elektromagnetischer Energie betätigt wird.

Fig. 7

zeigt eine Schnittansicht durch einen weiteren beispielhaften erfindungsgemäßen Kompressor.

Fig. 8

zeigt eine Schnittansicht eines Ausschnitts von einem weiteren beispielhaften erfindungsgemäßen Kompressor.

Fig. 9

zeigt eine Schnittansicht eines Ausschnitts von einem weiteren beispielhaften erfindungsgemäßen Kompressor.

Further advantages, features and possible uses of the present invention result from the following description with reference to the attached figures.

Fig. 1

shows a sectional view through an exemplary compressor according to the invention.

Fig. 2a and Fig. 2b

each show a three-dimensional view of two exemplary holding plates according to the invention.

Figures 3a to 3d

show a sequence of an exemplary assembly of a valve element according to the invention on the valve and holding plate.

Figures 4a to 4c

show a sequence of an exemplary assembly of a spring according to the invention on the valve element.

Fig. 4d

shows a representation of the exemplary spring according to the invention from the Figures 4a to 4c ,

Fig. 5

shows a further exemplary valve device according to the invention with a different spring and securing device on the valve element.

Fig. 6

shows another exemplary valve device according to the invention, which is actuated by means of electromagnetic energy.

Fig. 7

shows a sectional view through a further exemplary compressor according to the invention.

Fig. 8

shows a sectional view of a section of a further exemplary compressor according to the invention.

Fig. 9

shows a sectional view of a section of a further exemplary compressor according to the invention.

Fig. 1 shows a sectional view through an exemplary compressor 10 according to the invention. This has a housing 11 with a piston chamber 16 in a crankcase 15, in which a piston 30 movable in the piston chamber 16 is arranged, which is driven via a connecting rod 34 by a crankshaft, not shown. The housing 11 also has a valve plate 12, a holding plate 13 designed as an intermediate plate and a cylinder head 14. A harmful space 18 extends in the holding plate 13, the valve plate 12 and the cylinder head 14.

The compressor 10 also has a valve device 20 with a valve element 21 which extends through the holding plate 13 and is formed in one piece with a shut-off body 22 and an actuating section 23. The actuating section 23 is designed such that it supports the valve element 21 in the cylinder head so as to be axially movable. The valve device also has a valve seat 24 which is formed in a recess 26 of the valve plate 12 which is connected to the piston chamber 16. In the illustration shown, the piston 30 of the compressor 10 is located precisely at the upper reversal point in the piston chamber 16, at which it bears almost on the valve plate 12.

The valve element 21 is movably mounted in a valve chamber 17 formed in the cylinder head 14 along the axis A of the valve element 21. The valve chamber 17 is delimited on the side facing away from the piston chamber 16 by the cylinder head 14 without having an assembly opening or the like. On this side, the valve chamber 17 of the exemplary embodiment has a supply opening 19 for compressed air. The actuating section 23 of the in Fig. 1 The exemplary embodiment shown has the shape of a pneumatic piston and is designed to seal against the wall of the valve chamber 17. To operate the valve device 20, compressed air is supplied to the valve chamber 17 through the supply opening 19. The valve element 21 is actuated directly by the pneumatic energy and moves along its axis A against the restoring force of the spring 27 supported on the holding plate 13 in the direction of the piston chamber 16, as a result of which the shut-off body 22 lifts off the valve seat 24. In this way, a connection between the harmful space 18 and the piston space 16 can be released to relieve the load on the compressor, through which the air can flow from the piston space 16 into the harmful space 18.

Fig. 2a shows a three-dimensional view of an exemplary holding plate 13 according to the invention. The holding plate has a holding plate opening 13a, through which in the assembled state in the compressor 10 of the embodiment of FIG Fig. 1 the harmful space 18 extends. Furthermore, the holding plate opening 13a is designed such that the valve element 21 together with the actuating section 23 can be guided through the holding plate 13 during assembly. In addition, the holding plate opening 13a is designed in such a way that there is sufficient support surface for the spring 27 in the area around the valve element 21 (shown here by the axis A) after being installed in the operating position. In the exemplary embodiment, this is achieved in that the valve element 21 is guided in an inclined manner through the area of the holding plate opening 13a with a large opening cross section during assembly with the actuating section 23. In the later, in Fig. 1 In the vertical operating position, the valve element 21 extends through the holding plate in a section in which it has a small diameter. This small-diameter section is located in the operating position in a recess 13b at the edge of the holding plate opening 13a, so that the spring 27 rests on the holding plate 13 in a large area around the valve element 21.

Fig. 2b shows a three-dimensional view of a further exemplary holding plate 13 according to the invention. The holding plate 13 points opposite the holding plate 13 Fig. 2a only a small extent and is arranged in a recess between the valve plate 12 and the cylinder head 14. The holding plate 13 is designed such that it does not have a holding plate opening 13a through which the valve element 21 would have to be guided during assembly. The holding plate 13 has a holding plate recess 13b which is designed such that there is sufficient support surface for the spring 27 in the region around the valve element 21 which is in the operating position after assembly (also indicated here by the axis A). In the exemplary embodiment, this is achieved in that the valve element 21 is guided past the holding plate 13 in an inclined manner during assembly with the actuating section 23. In the later operating position, the valve element 21 extends through the holding plate recess 13b. A spring 27 arranged around the valve element 21 by way of example thus lies on the holding plate 13 in a large area around the valve element 21.

The Figures 3a to 3d show a sequence of an exemplary assembly of an exemplary valve element 21 according to the invention on the valve plate 12 and the holding plate 13, which is designed in the form of an intermediate plate. The actuating section 23 of the valve element 21 is protected by a mounting cap 25 during this assembly. During assembly, the valve element 21 is guided with the fastening section 23 ahead of the later operating position, through the recess 26 in the valve plate 12 to the holding plate opening 13a ( Fig. 3a ). The upper area of the valve element is then passed through the valve plate 12 and the holding plate opening 13a ( Fig. 3b ) until the actuating section 23 or the section of the valve element 21 which has a larger diameter than the region of the valve element 21 which extends through the holding plate 13 in the operating position has passed through the holding plate opening 13a and the shut-off body 22 Recess 26 is located in the valve plate 12. In addition to the actual actuation area 23, the valve element 21 can also have other areas with an enlarged diameter, depending on the type of actuation and mounting of the valve element 21. The valve element 21 is then brought into its operating position in which the shut-off body 22 rests on the valve seat 24.

In Fig. 3c the valve element 21 is in the operating position in which it extends in the valve plate 12 and the holding plate 13 and the shut-off element 22 rests on the valve seat 24. In Figure 3d the valve element is in the same position as in Fig. 3c , but here the spring 27 is already mounted between a shoulder 21a on the valve element 21 and the holding plate 13. As can be clearly seen, in the valve element 21 the mounting cap 25, which protects the actuating section 23 during assembly, has been removed from the fastening section 23.

The Figures 4a to 4c show a sequence of an exemplary assembly of a spring 27 on the valve element 21 in its operating position. The already during the in the Figures 3a to 3c The illustrated implementation of the valve element 21 through the valve plate 12 and the holding plate 13 on the actuating section 23 arranged mounting cap 25 rests at its lower end on the shoulder 21a on the valve element 21 and points in this area at least the same outer diameter as the paragraph 21a. In the upper area, the mounting cap 25 has a conical section, on which in the illustration in FIG Fig. 4a the likewise conical spring 27 is seated.

As in Fig. 4a is shown, an assembly tool 40 can be placed on the assembly cap 25, by means of which the spring is pushed onto the assembly cap 25 by axial pressure. In particular, the diameter of the turns of the spring 27, which is originally smaller than the outer diameter of the shoulder 21a, is expanded when the spring is pushed onto the mounting cap 25.

In Fig. 4b the end of the assembly situation is shown, in which the spring 27 has already been pushed with the aid of the assembly tool 40 over the assembly cap 25 and the shoulder 21a of the valve element 21. As in Fig. 4c is shown, the upper turns of the spring 27 return to their original smaller diameter after crossing the mounting cap 25 and can thus be supported on the shoulder 21a on the valve element 21. The lower turns of the spring 27 are supported on the holding plate 13, so that an axial force F acts on the valve element 21 due to a longitudinal compression of the spring between the shoulder 21a and the holding plate 13. In this way, the shoulder 21a is acted on away from the holding plate 13 and the shut-off body 22 is held on the valve seat 24.

Fig. 4d shows a representation of the exemplary spring 27 according to the invention from the Figures 4a to 4c , It can be clearly seen that the spring is conical. The upper turns, which are supported after assembly on the shoulder 21a, consequently have a smaller diameter than the lower turns, which are supported on the holding plate 13 after assembly. Since the recess 13b at the edge of the holding plate opening 13a is only open in an area which is necessary for the lateral insertion of the valve element 21 ( Figs. 2a, 2b ), the spring 27 can be supported in the exemplary embodiment on a sufficiently large area of the holding plate 13.

Fig. 5 shows a further exemplary valve device 20 according to the invention with a cylindrical spring 28 and a locking washer 29, which on Valve element 21 is attached. In the Fig. 5 The valve device 20 shown differs from the valve device 20, which is shown in the previous figures, essentially in that a groove 29a is formed on the valve element 21 instead of the shoulder 21a for receiving a locking washer. In this exemplary embodiment, after the valve element 21 has been passed through the holding plate opening 13a or into the holding plate recess 13b, a cylindrical spring 29, the inner diameter of which is larger than the outer diameter of the actuating section 23 of the valve element 21, is guided over the valve element 21 and by means of the in the groove 29a inserted locking washer 29 supported on the valve element 21.

Fig. 6 shows a further exemplary valve device 20 according to the invention, which can be actuated by means of electromagnetic energy. The valve element 21 has an actuating section 23 with a magnetically conductive active device, which is mounted in the region of an electromagnet 35 arranged on the cylinder head 24 and can be moved in the direction of the axis A of the valve element 21 by exposure to electromagnetic energy. In the embodiment shown, the valve device 20 is opened by acting on the actuating section 23 of the valve element 21 and, in the absence of electromagnetic energy, is closed by the restoring force of the spring 27. The valve element 21 out Fig. 6 In addition to the actuating section 23, it has a bearing section 21b, by means of which the valve element 21 is mounted in the valve head 17 in the cylinder head 14.

Fig. 7 shows a sectional view through a further exemplary compressor 10 according to the invention Fig. 7 The compressor 10 shown differs from the compressor 10 shown in FIG Fig. 1 is shown in that the valve plate 12 is flat, so that the harmful space 18 does not extend into the valve plate 12. This embodiment of the compressor 10 has a so-called supercooling plate as an intermediate plate, which also serves as a holding plate 13. In this embodiment, the harmful space 18 is formed in the holding plate 13 and in the cylinder head 14. The shape of holding plate opening 13a with holding plate recess 13b corresponds to that in FIG Fig. 7 Embodiment shown essentially from the shape of the holding plate opening 13a with holding plate recess 13b Fig. 2a ,

Fig. 8 shows a sectional view of a section of a further exemplary compressor 10 according to the invention. The holding plate 13 of this compressor 10 has a U-shape and is arranged in recesses in a flat valve plate 12. Analog to the embodiments of Figures 1 to 7 the valve element 21 is inclined with respect to the later functional position (in Fig. 8 shown) through the valve plate 12 and the holding plate opening 13a of the holding plate 13 and then tilted into the functional position shown, the valve element 21 entering the holding plate recess 13b. After inserting the valve element 21 into the valve plate 12, the spring 27, as in the Figures 4a to 4c is shown, mounted on the valve element 21. The cylinder head 14 is then mounted on the compressor, the actuating section 23 of the valve element 21 being guided into an actuating element 32. The actuating element 32 is mounted in the valve chamber 17 of the cylinder head 12 and is designed such that the actuating section 23 of the valve element can be accommodated and stored in the center thereof. The actuating element 32 can lie loosely on the actuating section 23 (as in FIG Fig. 8 ) and transmit mechanical energy to the valve element 21 by a positive connection with the valve end or the shoulder 21a on the valve element 21 as an active device. It is also possible for the valve element to be screwed into a thread formed in the actuating element 31, a corresponding external thread then being provided on the actuating section 23 of the valve element 21 as an active device. By actuating the valve chamber 17 with compressed air, the actuating element 32 is accelerated in the direction of the piston chamber 16, as a result of which mechanical energy is applied to the actuating section 23 of the valve element 21. In this way, the valve element 21 is actuated and lifted off the valve seat 24 as a result of the shut-off body 22. In the embodiment shown, the actuating force can be increased due to the enlarged surface of the actuating element 32.

Fig. 9 shows a sectional view of a section of a further exemplary compressor 10 according to the invention Fig. 9 differs from the compressor 10 Fig. 8 only in that there is no holding plate 13 is provided. In this exemplary embodiment, the spring 27 is supported directly on the valve plate 12.

All of the illustrated embodiments have in common that the cylinder head 14 is mounted on the valve element or on the holding plate 13 or the valve plate 12 after the assembly of the spring 27, 28. The valve element 21 is guided along its axis A with the actuating section 23 and optionally with a bearing section 21b into the valve chamber 17 formed in the cylinder head 14. Since the valve device 20 is already installed before the cylinder head 14 is put in place, there is no need for an installation opening on the cylinder head 14 via which the valve device 20 is accessible from the outside. The valve chamber 17 can therefore be designed on the side facing away from the piston chamber 16, that is to say the outside of the cylinder head 14, bounded by the cylinder head.

LIST OF REFERENCE NUMBERS

10

compressor

11

casing

12

valve plate

13

Retaining plate

13a

Retaining plate opening

13b

Recess on the edge of the holding plate opening

14

cylinder head

15

crankcase

16

piston chamber

17

valve chamber

18

dead space

19

feed

20

valve means

21

valve element

21a

Heel on the valve element

21b

bearing section

22

shut-off

23

actuating section

24

valve seat

25

mounting cap

26

Recess in the valve plate

27

feather

28

feather

29

lock washer

29a

Groove on the valve element

30

piston

32

actuator

34

pleuel

35

electromagnet

40

assembly tool

Claims (10)

1. Compressor (10) for producing compressed air for a utility vehicle, the compressor (10) having the following features:

   - a housing (11) with a crankcase (15), a cylinder head (14), a piston space (16) in the crankcase (15) and a dead space (18) which is formed at least partially in the cylinder head (14) of the compressor (10),

   - a valve device (20) with a valve element (21) comprising an actuating section (23) and a blocking element (22) for separating the dead space (18) from the piston space (16), such that to open the valve device (22) the blocking element (22) can be lifted clear of a valve seat (24) formed in a valve plate (12) in the direction towards the piston space (16),

   - wherein the valve element (21) is made integrally with the actuating section (23) and the valve plate (12) is designed such that the valve element (21) with the actuating section (23) can be passed through it in the direction towards the cylinder head (14), until the blocking element (22) contacts the valve seat (24) and the actuating section (23) is in the cylinder head (14),

   characterised in that
   in the area between the valve plate (12) and the cylinder head (14) there is arranged a holding plate (13), which has a holding plate recess (13b) with a cross-section that corresponds at least to the cross-section of the valve element (21) in an area between the blocking element (22) and the actuating section (23), and which is made open at the side so that when the valve element (21) is guided in the direction towards the cylinder head (14) it can be accommodated by the holding plate recess (13b) by being introduced from the side, so that in the area between the blocking element (22) and the actuating section (23) the valve element (21) extends through the holding plate (13).
2. Compressor according to Claim 1,
   characterised in that
   the valve element (21) is fitted in a valve space (17) of the cylinder head (14) so that it can move along the axis (A) of the valve element (21), the said valve space (17) being delimited on the side facing away from the piston space (16) by the cylinder head (14).
3. Compressor according to Claim 1,
   characterised in that
   the valve element (21) is fitted in a valve space (17) of the cylinder head (14) so that it can move along the axis (A) of the valve element (21), the said valve space (17) being delimited on the side facing away from the piston space (16) by an intermediate plate.
4. Compressor according to any of the preceding claims,
   characterised in that
   on the valve element (21) there is arranged a valve closing device (27, 28), by means of which, to close the valve device (20), the blocking element (22) can be moved in the direction away from the piston space (16) towards the valve seat (24), and the valve closing device (27, 28) is supported on the holding plate (13) or the valve plate (12).
5. Compressor according to Claim 4,
   characterised in that
   the valve closing device (27, 28) is supported on the valve element (21) on the side opposite to the holding plate (13) and/or the valve plate (12).
6. Compressor according to Claims 4 or,
   characterised in that
   the valve closing device (27, 28) is a spring (27) of conical shape, such that the smallest diameter of the spring (27) is smaller than the diameter of a section (21a) of the valve element (21), against which the spring (27) is supported and over which the spring (27) can be guided during assembly.
7. Compressor according to any of the preceding claims,
   characterised in that
   the blocking element (22) can be lifted clear of the valve seat (24) in the direction towards the piston space (16) by acting upon the actuating section (23) of the valve element (21) directly with pneumatic, electromagnetic or mechanical energy.
8. Compressor according to any of the preceding claims,
   characterised in that
   the compressor comprises at least one further valve device (20) with at least one further valve element (21) and/or at least one further piston space (16).
9. Compressor according to Claim 8,
   characterised in that
   the piston space (16) and the at least one further piston space (16) are preferably connected with one another by way of at least one dead space (18), when the valve device (20) and the at least one further valve device (20) are opened.
10. Method for relieving a compressor (10) for the production of compressed air for a utility vehicle,
    the compressor (10) having:

    - a housing (11) with a crankcase (15), a cylinder head (14), a piston space (16) in the crankcase (15) and a dead space (18) formed at least partially in the cylinder head (14),

    - a valve device (20) with a valve element (21), which extends through a holding plate (13) and is made integrally with an actuating section (23) and a blocking element (22) for separating the dead space (18) from the piston space (16), wherein to open the valve device (20) the blocking element (22) can be lifted clear of a valve seat (24) formed in a valve plate (12) in the direction towards the piston space (16),

    - wherein the holding plate (13) is located in the area between the valve plate (12) and the cylinder head (14) and has a holding plate recess (13b) with a cross-section that corresponds at least to the cross-section of the valve element (21) in an area between the blocking element (22) and the actuating section (23), and which is made open at the side so that when the valve element (21) is guided in the direction towards the cylinder head (14), it can be accommodated by the holding plate recess (13) by being introduced from the side, so that in the area between the blocking element (22) and the actuating section (23) the valve element extends through the holding plate (13),

    the said method comprising the following step:

    - opening of the valve device (20) by acting directly upon the actuating section (23) of the valve element (21) with pneumatic, electromagnetic or mechanical energy, in order to relieve the compressor (10).

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