Valve device for operation with refrigerant

Abstract

The invention relates to a valve arrangement for operation with a refrigerant, in particular for operation with a refrigerant in a motor vehicle heat pump system, having a valve body bushing (1) with a first axial section (1.1) provided for insertion into a valve block (2), in which valve body bushing a valve body chamber (3) is formed, the valve body chamber has a valve needle (4) axially guided therein; a spindle drive having a magnetized rotor shaft (5) supported by anti-friction bearings (6) and coupled to the valve needle (4) such that rotation of the rotor shaft (5) causes axial movement of the valve needle (4) in the valve body bushing (1); and a capsule element (7) which is open on one side, in which the spindle drive and the second axial section (1.2) of the valve body bushing (1) are received, the capsule element (7) being securable to the valve block (2) by means of an actuator (8) for driving the rotor shaft (5) which receives the capsule element, such that the first axial section (1.1) is received in the valve block (2) in a fluid-tight manner.

Description

Technical Field

[0001] The invention relates to a valve device for operation with a refrigerant, in particular for operation in a heat pump system of a motor vehicle air conditioning system, in which system carbon dioxide, CO2 (R744) or 2,3,3,3-tetrafluoropropene (R1234yf) is used as refrigerant. Background Art

[0002] Compared with vehicles with classic internal combustion engines, there is no similar continuous heat source available for vehicle air conditioning in electric vehicles. Therefore, in order to control the temperature of a purely electrically operated vehicle, it is necessary to utilize the available electrical energy, which in the case of a vehicle operated with battery power, especially when large temperature differences must be overcome, can lead to a significant reduction in vehicle mileage. Compared with conventional electric heaters, heat pump systems with a refrigerant circuit help to improve the utilization of available electrical energy. The two-way operation of such a system enables heating in winter and cooling in summer. Heat pump systems that can be operated with carbon dioxide (R744) as a refrigerant are particularly preferred because R744 has a very low global warming potential. However, the operation of a heat pump system with R744 as a refrigerant is associated with increased design requirements because larger or more robust components are required due to higher operating pressures. Therefore, the high pressure on the control element, particularly the two-way valve, correspondingly requires a high moving force, which can only be handled by an actuator with greater power.

[0003] The measure for reducing the high displacement forces on the valve device is based on the use of a counter-pressure device. From DE 10 2016 013492A1, a valve is known, which can be operated bidirectionally and in which the system back pressure is used to assist, so as to allow less workload for moving the control element. The valve known from DE 102016 013 492A1 is a combined expansion stop valve, which has a pressure bypass to the valve chamber in the closed state, in which the valve needle is guided. The pressure bypass leads to a pressure balance, which reduces the pressure force required for the valve needle regulation. A relatively large flow diameter can be ensured between the medium inlet of the valve in both flow directions. The valve advantageously allows a bidirectional refrigerant flow and the function of the expansion valve in respective opposite directions.

[0004] In the field of motor vehicles, compact solutions are preferred, as a result of which several valves are usually accommodated and arranged in a narrow space in a common valve block or valve module to affect the flow path. For example, up to eight valves of a heat pump system can be assembled in a valve block. So far, individual valve components, especially sealing seats with seals, have been directly designed in the valve block or positioned in the valve block. These individually designed valve components only cooperate with other components of the valve as a functional unit in the assembled state. However, the disadvantage caused by this is that in the case of maintenance or in the case of replacing an individual valve, the entire valve block device must be disassembled because the maintenance of the individual valve unit becomes more difficult due to the compact structure. In addition, it has been found that the valves of the currently known designs have a relatively high hysteresis in the flow curve, which may have an adverse effect on the operating process. Finally, due to the relatively high leakage potential, especially the leakage potential when using R744 refrigerant, it is also necessary to improve the structure of the valves for heat pump systems in motor vehicles. Summary of the invention

[0005] Technical issues

[0006] The object of the present invention is therefore to propose a valve device for operation with a refrigerant, in particular for operation with carbon dioxide (CO2 (R744)) in a heat pump system of a motor vehicle, with which the disadvantages known from the prior art can be reduced or avoided.

[0007] Technical Solution

[0008] According to the concept of the present invention, the main components of the valve device are received by the capsule element or are integrated in the capsule element, so that the valve device is formed as a complete functional unit without the need for valve components separately assembled in the valve block. The valve device according to the present invention can advantageously be assembled or disassembled separately without replacing the entire valve block or valve module. In the context of the present invention, a valve block or valve module should be understood to mean a body that receives several valves or valve devices and has several connectors and channels through which the flow of fluid is regulated. For simplicity, the term valve block is used uniformly below. The valve device is configured to operate with a refrigerant, in particular for operating with a refrigerant in a motor vehicle heat pump system.

[0009] The valve device according to the invention has a valve body bushing having a first axial section arranged to be inserted into a valve block. The first axial section of the valve body bushing is received in the valve block. A valve body chamber is formed inside the valve body bushing, the valve body chamber having a valve needle guided axially therein. As another valve component, the valve device according to the invention comprises a spindle drive having a magnetized rotor shaft, the rotor shaft being supported by an anti-friction bearing and coupled to the valve needle, so that the rotation of the rotor shaft causes the axial movement of the valve needle in the valve body bushing. The axial movement causes the valve device to open or close, depending on the direction of rotation of the rotor shaft. In addition, the valve device according to the invention comprises a capsule element, which is open on one side and in which the spindle drive and the second axial section of the valve body bushing are received, wherein the capsule element can be fastened to the valve module by means of an actuator for driving the rotor shaft that receives the capsule element, so that the first axial section is received in the valve block in a fluid-tight manner.

[0010] The opening of the capsule element can have a stepped edge in the form of a radially outwardly directed collar, which, for the purpose of fastening the capsule element, interacts with a sleeve element supported or supported on the collar. Various means can be used to fasten the sleeve element guided on the capsule element, such as clamping means, snap-fit ​​means or threaded connections. With the aid of the fastening means, the collar end face is pressed against the opposite valve block surface for sealing the valve component received in the capsule element.

[0011] According to a particularly preferred design of the valve device of the invention, which is particularly provided for use with the refrigerant R744, it is advantageous that the threaded ring is used as a sleeve element. The threaded ring is in the form of a cylindrical ring with an opening, through which the capsule element is guided and thereby received by the threaded ring. In doing so, the threaded ring is supported on the capsule element collar with its side facing the valve block. On the radial outer surface, the threaded ring has an external thread for screwing into the valve block. In order to fasten the capsule element, the threaded ring is guided on the capsule element and can be screwed to the internal thread formed in the valve block while being supported on the collar of the capsule element. In this case, a seal, preferably a metal convex seal, is arranged between the end face formed in the axial direction of the capsule element collar and the end face of the valve block or the valve block facing the end face of the capsule element collar. In addition, the threaded ring has an engagement device for a tool so that the threaded ring is screwed to the valve block using a tool. The engagement device for the tool can be formed axially and / or radially on the threaded ring. For example, the threaded ring can have a toothed ring as an engagement device. By means of a threaded connection with a threaded ring in the valve block, a defined contact pressure can be generated, which in combination with the metal bead seal contributes to a particularly good seal. The use of a metal bead seal advantageously reduces the risk of leakage. This is advantageous in heat pump systems which have to operate at high operating pressures due to the use of R744 as refrigerant.

[0012] According to another advantageous design of the valve device according to the invention, which is preferably provided for operation with a refrigerant, the refrigerant 2,3,3,3-tetrafluoropropene (R1234yf) or the refrigerant dichlorotrifluoroethane (R134a), a fastening plate can be used as a sleeve element, which is guided on the capsule element for fastening the capsule element and can be fastened to the valve block in a manner supported on a collar of the capsule element. Therefore, the fastening plate has at least one opening so that the fastening plate can receive the capsule element, wherein the cross section of the opening is designed so that the fastening plate is supported on the collar of the capsule element. On the side facing the valve block, the fastening plate can have a supporting stud, through which the at least one opening is formed. The end face of the supporting stud is formed to be supported on the collar of the capsule element. The supporting stud can also have a collar, which is oriented radially outwards and whose collar end face is preferably supported on the collar of the capsule element in a form-fitting manner. Furthermore, the fastening plate can have at least two screw passages, through which screws can be screwed into the valve block, wherein a contact pressure is exerted on the fastening plate which is supported or mounted on the capsule element collar.

[0013] A corrosion protection element in the form of an O-ring may be arranged between the fastening plate and the valve module. The O-ring may be arranged at the shank end of the support stud of the fastening plate.

[0014] For the actuator, the fastening plate preferably serves as a limiter and a retainer. For the fastening of the connection between the actuator and the capsule element, the actuator may also have a screw passage corresponding to the screw passage of the fastening plate, so that the screw can be screwed into the valve block receiving the valve device through the screw passage of the actuator and through the screw passage of the fastening plate. In this way, the capsule element with the valve component arranged therein and the actuator can be fastened to the valve block together at the same time.

[0015] The anti-friction bearing that receives and supports the rotor shaft of the spindle drive in the valve body bushing can be formed as a ball bearing or a roller bearing. According to an advantageous design, the anti-friction bearing is received in the valve body bushing in the region of the second axial section and is preferably fixed in the valve body bushing by an edge flange. For simplicity, the edge flange of the upper edge of the valve body bushing can be formed to fix the anti-friction bearing at a specific position, for example at two, three or four positions. Due to the reduced frictional resistance, the rotation of the rotor shaft is absorbed by the anti-friction bearing in a smoother running manner, so that less driving force must be consumed overall. The frictional resistance reduced by the anti-friction bearing advantageously contributes to the reduction of flow hysteresis.

[0016] In order to further stabilize the bearing of the rotor shaft, a sliding bearing can be additionally received in the capsule element. The sliding bearing can preferably be positioned on the capsule element bottom, wherein the shank end or pin of the rotor shaft is received by the sliding bearing. Furthermore, the sliding bearing can be provided as an integral part of the capsule element.

[0017] The second section of the valve body bushing can be axially inserted into the capsule element so that only the first axial section of the valve body bushing, which is arranged to be inserted into the valve module, protrudes from the capsule element. For this purpose, the valve body bushing can have a stop rib formed on the outer circumference. Inserted into the capsule element, the stop rib ensures the correct and accurate positioning of the valve body bushing in the capsule element and thereby limits the axial insertion depth of the second section of the valve body bushing. The stop rib forms a lip that can be radially merged into the end face of the collar at the capsule element opening. In this way, a sealing effect relative to the capsule element is ensured. Preferably, the outer diameter of the valve body bushing corresponds to the inner diameter of the capsule element.

[0018] The valve needle guided in the valve body bushing and axially movable back and forth can have at least one groove extending around the outer circumference, the at least one groove having a seal for internal sealing relative to the valve body bushing. This seal, which can also be referred to as a valve needle seal, is formed as a combined seal with an O-ring and an outwardly pointing polytetrafluoroethylene (PTFE) ring arranged on the O-ring, especially for use with the refrigerant R744.

[0019] In the first section, preferably in the region of the head end, the valve body bushing can have at least one groove extending around the outer circumference, the at least one groove having a seal for internal sealing relative to the valve block. The seal is preferably formed as a sealing ring or an O-ring. Furthermore, it can be provided that the valve body bushing has different shank diameters in the first section, wherein each shank diameter has at least one groove extending around the outer circumference, the at least one groove having a seal for internal sealing relative to the valve block. According to a design of a valve device according to the invention, which is particularly provided for operation with refrigerant R1234yf or refrigerant R134a, the valve body bushing inserted into the capsule element in the second axial section can have at least one groove extending around the outer circumference, the at least one groove having a seal for internal sealing relative to the capsule element.

[0020] The valve needle can have a cylindrical shape in some areas, wherein the receiving part in the valve body bushing is also formed in a cylindrical manner. At least the upper shank end of the valve needle can have a recess corresponding to the cross-sectional geometry of the valve body bushing in order to prevent rotation. The cross-sectional geometry of the valve body bushing forms a guide for the valve needle. Alternatively, a guide disk can be provided, which is pressed into the valve body bushing. The guide disk has an open cross-section corresponding to the cross-sectional geometry of the upper shank end of the valve needle, which prevents rotation of the valve needle. Therefore, the guide disk can be pressed into the valve body bushing, wherein the guide disk has an open cross-section for receiving the valve needle and guides the valve needle axially. The use of the guide disk proves to be advantageous for the assembly of the valve needle in the valve body bushing, because the valve needle is first positioned in the valve body bushing and the guide disk is subsequently pressed into the valve body bushing.

[0021] For further sealing, a seal in the form of a sealing ring may be arranged between the capsule element and the actuator.

[0022] The valve body bushing and the valve needle can be formed so that in the closed state of the valve device there is a pressure bypass to the valve body chamber. In this case, in particular when using the refrigerant R744, the free diameter in the pressure bypass for pressure equalization can be increased. The size of the free diameter of the pressure bypass required to provide pressure equalization depends on the refrigerant used and the size of the valve device.

[0023] It may be provided that the valve needle diameter for use with the refrigerant R744 is dimensioned to be smaller than the valve needle diameter for use with the refrigerants R1234yf or R134a.

[0024] The main advantage of the valve device according to the invention is that all valve components required for valve operation are brought together in a common component arrangement received by the capsule element. Therefore, no valve components remain in the valve block. Therefore, the valve device according to the invention can be completely assembled and disassembled as a functional unit. This is also advantageous for maintenance, since there is no need to disassemble the entire valve block. The additional implementation of a pressure compensation system reduces the required movement forces with the help of a pressure bypass, so that the actuator components can be implemented to be smaller in size. Therefore, pressure compensation relieves the valve device, which increases the robustness of the entire system.

[0025] The invention is intended for operation with a refrigerant, in particular for operation in a heat pump system of a motor vehicle air conditioning system, in which system carbon dioxide (CO2 (R744)) or 2,3,3,3 tetrafluoropropene (R1234yf) is used as refrigerant. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Further details, features and advantages of the design of the present invention will become apparent from the following description of exemplary embodiments with reference to the associated drawings, in which:

[0027] Figure 1 : A schematic cross-sectional view showing an exemplary embodiment of a valve device according to the present invention,

[0028] Figure 2 : A schematic diagram showing an exemplary embodiment of a valve needle of a valve device according to the present invention is shown in a three-dimensional view,

[0029] Figure 3a : a schematic representation of a perspective view showing a combination of a rotor shaft and a valve body bushing of a valve device according to the invention,

[0030] Figure 3b : shows a schematic diagram of a metal convex seal,

[0031] Figure 3c : A schematic diagram showing a guide disc of a valve device according to the present invention,

[0032] Figure 4 : A schematic cross-sectional view showing the interaction between the capsule element and the valve block of the valve device according to the present invention,

[0033] Figure 5a to Figure 5l : shows the assembly steps for assembling the valve device according to the present invention,

[0034] Figure 6a : A schematic diagram showing the design of the valve device according to the present invention in an assembled state without an actuator,

[0035] Figure 6b : It shows that the Figure 6a The design of the valve device of the actuator shown in

[0036] Figure 6c : Shows Figure 6a A schematic cross-sectional view of a design of a valve device according to the invention is shown in FIG.

[0037] Figure 7 : shows a schematic cross-sectional view of a valve device according to the present invention, wherein components of a capsule element and a valve body bushing are operatively connected to a valve block, and

[0038] Figures 8a to 8n : Shown for assembly Figure 6a The assembly steps of the design of the valve device according to the invention are shown in FIG.

[0039] Recurring features are identified in the drawings by the same reference numerals. DETAILED DESCRIPTION

[0040] Figure 1 A schematic cross-sectional view of an exemplary embodiment of a valve device according to the invention for operation with the refrigerant R744 is shown. The valve device comprises a valve body bushing 1 in which a valve body chamber 3 is formed, the valve body chamber 3 having a valve needle 4 axially guided therein. A first axial section 1.1 of the valve body bushing 1 is provided for insertion into a valve block 2 (see Figure 4 ). A second axial section 1.2 of the valve body bushing 1 is received to be inserted in the capsule element 7. The axial insertion depth of the valve body bushing 1 is limited by a stop rib 1.3 formed on the outer circumference of the valve body bushing 1. The stop rib 1.3 forms a common contact surface with a stepped edge in the form of a radially outwardly directed collar 7.1 formed on the capsule element 7. In addition, a spindle drive with a magnetized rotor shaft 5 is received in the capsule element 7, which is supported by an anti-friction bearing 6 in the form of a ball bearing positioned in the valve body bushing 1. The rotor shaft 5 has a threaded shank 5.1, which is screwed into the internal thread of the valve needle 4, so that the rotation of the rotor shaft 5 causes the axial movement of the valve needle 4 guided in the valve body bushing 1. The rotation of the rotor shaft 5 is generated by a magnetic actuator (not shown) that receives the capsule element 7. For this purpose, the rotor shaft 5 is injection molded with a magnet 5.2. A sliding bearing 12 is arranged on the capsule element bottom of the capsule element 7. The slide bearing supports a pin 5 . 3 of the rotor shaft 5 .

[0041] The valve device is fastened to the valve block 2 ( Figure 4). In order to fasten the capsule element 7, the threaded ring 14 is guided on the capsule element 7 so that the threaded ring 14 can be screwed to the internal thread 23 formed in the valve block 2 while being supported on the capsule element collar 7.1. For sealing purposes, a threaded ring 14 is arranged between the end face of the capsule element collar 7.1 formed in the axial direction of the capsule element 7 and the valve block 2. Figure 3b The metal convex seal 19 presented in FIG.

[0042] The valve needle 4 has a radial through hole 10, which forms a pressure bypass to the valve body chamber 3. In order to prevent the valve needle 4 from rotating in the valve body bushing 1, a guide disk 11 is pressed into the valve body bushing 1. Figure 3c A possible design of the guide disk 11 is explained in more detail in FIG. In addition, the valve needle 4 has a groove 4.1 formed on the outer circumference with a combined seal 9, Figure 2 The valve needle 4 is explained in more detail in FIG, wherein the valve needle 4 is presented separately. A further seal 13.1 is arranged at the head end of the valve body bushing 1 in a groove 13 located on the outer circumference. The seal 13.1 is formed as an O-ring. The first axial section 1.1 of the valve body bushing 1 forms a shank with different diameters, wherein the central part of the shank, which tapers toward the center of the shank, has a smaller diameter than the head end of the valve body bushing 1, which has a groove 13 with a seal 13.1.

[0043] In order to position the capsule element 7 relative to the actuator 8 (see Figure 5l ) seal, a sealing ring 15 is arranged on the outer circumference of the capsule element 7. The surrounding sealing ring 15 can also be called an actuator seal.

[0044] Figure 2 A schematic representation of an exemplary embodiment of a valve needle 4 of a valve device according to the invention is shown in a perspective view. Figure 2 The valve needle 4 presented in FIG. 4 is particularly provided for use in a valve device for operation with the refrigerant R744. On the outer circumference, the valve needle 4 has a groove 4.1 for receiving a composite seal 9. The composite seal 9 comprises two components, namely a PTFE ring 9.1 and an O-ring 9.2, wherein the PTFE ring is arranged as a sliding seal in the groove 4.1 above the O-ring 9.2, so that the PTFE ring 9.1 points radially outwards.

[0045] Figure 3aA schematic representation of a perspective view of a combination of a rotor shaft 5 and a valve body bushing 1 of a valve device according to the invention is shown. The rotor shaft 5 has a magnet 5.2 for driving the rotor shaft 5. At the upper end, a pin 5.3 is formed for being received in a sliding bearing 12 of a capsule element 7. The ball bearing 6 supporting the rotor shaft 5 is pressed into the valve body bushing 1, wherein the fixing of the ball bearing 6 in the valve body bushing 1 is achieved by flanging the upper edge of the valve body bushing 1 at the arrow position.

[0046] Figure 3b The design of a metal bead seal 19 is shown, which is used, for example, for sealing between the end face of the capsule element collar 7.1 of the capsule element 7 and the valve block surface in order to ensure a fluid-tight seal of the valve arrangement relative to the environment. In the example shown, the metal bead seal 19 has three lugs for fixing, wherein more or fewer fixing lugs are conceivable. By using the metal bead seal 19, surface defects can be advantageously compensated, so that an improved seal can be ensured.

[0047] exist Figure 3c , the design of the guide disk 11 is shown, which is press-fitted in order to prevent rotation and to achieve axial guidance of the valve needle 4 in the valve body bushing 1. The opening cross section of the guide disk 11 is designed corresponding to the geometry of the upper shank of the valve needle 4. The corresponding geometry prevents the valve needle 4 from rotating in the cylindrically formed valve body bushing 1, so that the rotation of the threaded shank 5.1 of the rotor shaft 5 only causes an axial movement of the valve needle 4 in the valve body bushing 1.

[0048] Figure 4 A schematic cross-sectional view showing the interaction of the capsule element 7 and the valve block 2 of the valve device according to the present invention is shown, which is designed with a threaded connection for fastening the capsule element 7 to the valve block 2. For better illustration, in Figure 4 Other components of the valve device are not presented. For fastening purposes, a threaded ring 14 is guided on the capsule element 7, wherein the threaded ring 14 can be screwed into an internal thread formed in the valve block 2 while being supported on the collar 7.1 of the capsule element 7. In order to fasten the valve device to the valve block 2, an external thread 22 of the threaded ring 14 is screwed into an internal thread 23 formed in the valve block 2. An axial end face of the threaded ring 14 forms an annular surface that is at least partially supported on the capsule element collar 7.1. The end face of the capsule element collar 7.1 formed in axial alignment of the capsule element 7 forms a sealing surface relative to a supporting surface on the valve block 2, wherein a sealing surface of the capsule element collar 7.1 and a supporting surface of the valve block 2, which is not presented here, is arranged. Figure 3bThe metal bead seal 19 shown in FIG. 1 is provided. The threaded connection exerts the contact pressure of the capsule element collar 7.1 on the supporting surface of the valve block 2. It can be provided that the threaded ring 14 is tightened with a torque of 100 Nm. The combined force between the capsule element 7 and the valve block 2 compresses the metal bead seal 19, wherein the metal bead seal 19 compensates for surface defects in order to seal the valve device against the external environment.

[0049] Figure 5a to Figure 5l The assembly steps for assembling the valve device according to the invention according to the present design are shown.

[0050] Figure 5a A first assembly step of the valve device according to the invention is shown, wherein a sliding bearing 12 is introduced into the capsule element 7 such that the sliding bearing 12 is arranged at the bottom of the capsule element 7. The sliding bearing 12 is preferably formed of a material having low sliding friction.

[0051] Figure 5b A second assembly step of the valve device according to the invention is shown, wherein the ball bearing 6 is positioned on the rotor shaft 5 so that the rotor shaft 5 can be assembled with the ball bearing 6 as a unit.

[0052] Figure 5c The assembly of the combined seal 9 on the valve needle 4 is shown. As presented, the assembly is carried out in the direction of the arrow so that first the O-ring 9.2 is pushed from the lower shank side in the direction of the groove 4.1 and positioned there. Subsequently, the PTFE ring 9.1 is pushed over the cylindrical shank of the valve needle 4 and positioned in the groove 4.1 above the O-ring 9.2.

[0053] Next, the following is Figure 5d The fourth assembly step of the valve device according to the invention is presented in . This step comprises the positioning of the valve needle 4 in the valve body bushing 1. The assembly of the valve needle 4 is carried out in the direction of the arrow.

[0054] exist Figure 5e In the fifth step presented in , the guide disc 11 is pressed into the valve body bushing 1. The cross-sectional opening of the guide disc 11 receives the shank end of the valve needle 4, thereby preventing the valve needle 4 from rotating in the valve body bushing 1.

[0055] exist Figure 5f In the following sixth step shown in FIG. 1 , the valve needle 4 is screwed into the inner thread 23 according to the second step ( Figure 5b )The rotor shaft 5 of the preassembled spindle drive is combined with the valve body bushing 1.

[0056] also, Figure 5gA seventh assembly step of the valve device according to the invention is shown, wherein the ball bearing 6 is fixed in the valve body bushing 1 by means of the edge flanges marked at the positions of the arrows.

[0057] exist Figure 5h In the following eighth step shown in FIG. 5 , magnetization of magnets 5 . 2 arranged on rotor shaft 5 takes place.

[0058] exist Figure 5i FIG. 8 shows a ninth assembly step of a valve device according to the present invention. In the ninth step, Figure 5h The pre-assembled arrangement shown in FIG. 1 is inserted from the valve body bushing 1 and the spindle drive into the capsule element 7, wherein the insertion depth is limited by the stop ribs 1.3 formed on the outer circumference of the valve body bushing 1. Figure 5i As shown in the cross-sectional view of FIG. 5 , a part of the rotor shaft 5 , namely the upper pin 5 . 3 , is received by the sliding bearing 12 , so that the rotor shaft 5 is supported at two locations.

[0059] exist Figure 5j In the following tenth step presented in , the metal bead seal 19 is positioned on the sealing surface on the end face of the collar 7.1 of the capsule element 7, wherein a protective sleeve 20 is used for positioning, which is guided on the first axial section 1.1 of the valve body bushing 1. After the metal bead seal 19 is positioned, the protective sleeve 20 is removed again. In addition, the threaded ring 14 is positioned, which is pushed on the capsule element 7 and receives the capsule element collar 7.1 or is supported on the capsule element collar 7.1 in the process. The threaded ring 14 has an engagement element 24 for a tool. The engagement element 24 is formed as a tooth pointing radially outwards and serves to transmit torque forces from the tool to the threaded ring 14 when the threaded ring 14 is screwed into the valve block 2 (not shown).

[0060] Figure 5k An eleventh assembly step of the valve device according to the invention is shown, wherein a seal 13 . 1 in the form of an O-ring is positioned on a groove 13 formed at the head end of the valve body bushing 1 .

[0061] Finally, if Figure 5l As shown in FIG. 1 , the actuator 8 is first assembled by guiding the sealing ring 15 on the capsule element 7. Then, the capsule element 7 is pushed into the actuator 8. The actuator 8 is fastened to the valve block 2 by means of screws 8.1 screwed into threads formed in the valve block 2 (see FIG. 1 ). Figure 4 ).

[0062] Figure 6aA schematic diagram of the design of a valve device according to the present invention for operation with the refrigerant R1234yf without an actuator 8 and a valve block 2 is shown. The valve device comprises a valve body bushing 1 having a first axial section 1.1 and a second axial section 1.2, wherein the second axial section 1.2 of the valve body bushing 1 is covered by a capsule element 7 receiving the second axial section 1.2. The first axial section 1.1 is provided for insertion into Figure 6a The valve block 2 not shown in the figure. The first axial section 1.1 includes an upper groove 17 with an upper seal 17.1 formed at the outer circumference. Another seal 13.1 is arranged in another groove 13 formed at the outer circumference at the head end of the valve body bushing 1. The second axial section 1.2 of the valve body bushing 1, which is covered due to being received in the capsule element 7, is inserted into the capsule element 7. In addition, the spindle drive is received in the capsule element 7 and is coupled to the valve needle 4 guided in the valve body bushing 1, so that the rotor shaft 5 of the spindle drive is coupled to the valve needle 4 - see Figure 6c ——The rotation of the valve needle 4 causes the axial movement of the valve needle 4 in the valve body bushing 1. In order to fasten the valve device to the valve block 2, a fastening plate 16 supported on the collar 7.1 of the capsule element 7 is provided, wherein four screw passages 16.1 are formed on the outer edge of the fastening plate 16. Figure 6b , screws guided through two diagonally opposite screw passages 16.1 can be screwed into the valve block 2 in order to fasten a fastening plate 16 to the valve block 2, wherein the capsule element 7 receives the fastening plate 16. The two remaining diagonally opposite screw passages 16.1 corresponding to the screw passages of the actuator 8 can be used to fix the actuator 8 to the fastening plate 16 by inserting a clamp element through the respective corresponding screw passages. Reference numeral 15 denotes an actuator seal, which is guided on the capsule element 7 as a sealing ring.

[0063] Figure 6b The three-dimensional diagram shows Figure 6aThe design of the combination of the valve device of the invention and the actuator 8 receiving the capsule element 7 shown in FIG. As can be seen, the fastening plate 16 additionally serves as a retainer or axial limiting element for the actuator 8. In order to fasten the actuator 8, the actuator 8 has a screw passage corresponding to the screw passage 16.1 of the fastening plate 16. Two screws 8.1 can be guided through diagonally opposite screw passages and screwed into the valve block 2, wherein the desired contact pressure for sealing the valve device according to the invention relative to the environment is achieved. It can be provided that the actuator 8 is positioned to be fixed on the fastening plate 16 by a clamp element, wherein the clamp element is inserted into the corresponding screw passage 16.1 of the fastening plate 16 through two diagonally opposite screw passages of the actuator 8. The clamp element fixes the actuator 8 to the fastening plate 16, so that the actuator 8 and the fastening plate 16 together with the capsule element 7 received in the actuator 8 form a component unit even before assembly with the valve block 2.

[0064] On the surface facing the valve block 2 , the fastening plate 16 has a stud on which a corrosion protection ring 18 is positioned.

[0065] Figure 6c A cross-sectional view of a valve device according to the invention for operation with the refrigerant R1234yf is shown. The valve device has a valve body bushing 1 having a valve body chamber 3 formed therein, in which a valve needle 4 is guided to be able to move axially back and forth. The back and forth movement is performed by a spindle drive comprising a magnetized rotor shaft 5, which is supported by an anti-friction bearing 6 received in the valve body bushing 1. In this case, the threaded shank 5.1 of the rotor shaft 5 is screwed into the internal thread of the valve needle 4, so that a rotation of the rotor shaft 5 causes an axial movement of the valve needle 4 in the valve body bushing 1, depending on the direction in which the rotor shaft 5 rotates.

[0066] A sliding bearing 12 is arranged at the bottom of the capsule element 7, which supports the pin 5.3 of the rotor shaft 5. The rotor shaft is thus supported by the ball bearing 6 and the sliding bearing 12. The rotor shaft 5 also has a magnet 5.2, by means of which the rotor shaft 5 can be set into a rotational movement from the outside by the action of an actuator 8 (not shown here).

[0067] The valve body bushing 1 has a first axial section 1.1 and a second axial section 1.2. The valve needle 4 is received in the first axial section 1.1. The first axial section 1.1 is provided for insertion into the valve block 2 not presented here, for which purpose the portion protrudes out of the capsule element 7. The second axial section 1.2 of the valve body bushing 1 is received for insertion into the capsule element 7, wherein the axial insertion depth of the valve body bushing 1 is limited by a stop rib 1.3 formed on the outer circumference of the valve body bushing 1. The valve needle 4 has a circumferential groove 4.1 in which a combined seal 9 is arranged, as shown in FIG. Figure 2 As shown in .

[0068] In the first axial section 1.1, the valve body bushing 1 has an upper groove 17 extending around the outer circumference and having an upper seal 17.1 in the form of an O-ring. The upper seal 17.1 is used for the upper sealing of the valve body bushing 1 relative to the valve block 2. In addition, a circumferential groove 13 is formed at the head end of the valve body bushing 1, wherein a sealing ring 13.1 is arranged in the groove 13. The sealing ring 13.1 is also used to seal the valve body bushing 1 relative to the valve block 2. When the first axial section 1.1 is inserted into the valve block 2, the outer circumferential sealing ring 13.1 of the valve body bushing 1 and the outer circumferential sealing ring 17.1 can cooperate with the valve block 2 by Figure 7 Come to understand.

[0069] On the side facing the valve block 2, the fastening plate 16 has a support stud 16.2 extending from the opening of the fastening plate 16 for receiving the capsule element 7. The end face of the support stud 16.2 is formed to be supported on the capsule element collar 7.1. In this case, the support stud 16.2 also has a radially outwardly oriented collar 16.2.1, the collar end face of which is supported on the capsule element collar 7.1 in a form-fitting manner.

[0070] The support stud 16.2 receives a corrosion protection element 18 in the form of a corrosion protection ring. On the side of the fastening plate 16 facing the valve block 2, a sealing ring 15 is arranged around the capsule element 7.

[0071] Figure 7A schematic cross-sectional view of a valve device is shown, in which the capsule element 7 and the components of the valve body bushing 1 are operatively connected to the valve block 2. In this illustration, for better illustration, the other components of the valve needle 4, the spindle drive and the fastening plate 16 are not presented. In this design, the second axial section 1.2 of the valve body bushing 1 has an additional groove 21 with a sealing ring 21.1 on the outer circumference, which is provided for sealing the valve body bushing 1 relative to the capsule element 7 receiving it. The capsule element 7 receiving the second axial section 1.2 of the valve body bushing 1 is supported on the countersunk surface formed in the valve block 2 by the end face formed by the collar 7.1, so that the first axial section 1.1 of the valve body bushing 1 is arranged in the stepped hole formed in the valve block 2. The axial depth of insertion into the capsule element 7 is limited by the stop rib 1.3 formed on the outer circumference of the valve body bushing 1. Therefore, the axial insertion depth corresponds to the length of the second axial section 1.2. The stop rib 1.3 and the end face of the collar 7.1 together form a contact surface for contacting the valve block 2. In the first axial section 1.1, the upper shank end of the valve body bushing 1 has an upper groove 17 extending around the outer circumference with an upper seal 17.1 in the form of an O-ring. In addition, a circumferential groove 13 is formed at the head end of the valve body bushing 1, wherein a sealing ring 13.1 is arranged in the groove 13.

[0072] Figures 8a to 8n Shown for assembly Figure 7 Schematic diagram of assembly steps for a design of a valve device according to the invention is shown in FIG.

[0073] exist Figure 8a In a first step shown in FIG. 1 , the sliding bearing 12 is inserted into the capsule element 7 and positioned on the capsule element base, as shown in the cross-sectional view.

[0074] exist Figure 8b In a second step shown in FIG. 1 , a ball bearing 6 is positioned on the rotor shaft 5 . Figure 8c The third assembly step is shown, in which the combined seal comprising an O-ring 9.2 and a PTFE ring 9.1 is positioned in a groove 4.1 formed on the outer circumference on the valve needle 4. First the O-ring 9.2 is placed in the groove 4.1 and then the PTFE ring 9.1 is arranged in the groove 4.1 above the O-ring 9.2 so that the PTFE ring 9.1 points radially outwards.

[0075] also, Figure 8d A fourth assembly step is shown, in which the valve needle 4 is pushed into the valve body bushing 1 in the direction of the arrow and positioned in the first axial section 1 . 1 of the valve body bushing 1 . Reference numeral 1 . 3 denotes a stop rib on the valve body bushing 1 .

[0076] In the following, Figure 8eAs shown in FIG. 1 , the guide disc 11 is pressed into the valve body bushing 1 so that the cross section of the upper shank of the valve needle 4 is received by the opening cross section of the guide disc 11 to prevent the valve needle 4 from rotating in the valve body bushing 1 . Figure 8e The cross-sectional view of the valve body bushing 1 shows the press-fit arrangement of the guide disc 11 in the valve body bushing 1. Figure 8f The following sixth step is shown in . This step is provided for arranging a sealing ring 21 . 1 in the form of an O-ring in a groove 21 formed in the second axial section 1 . 2 . The arrangement starts in the direction of the arrow from the direction of the second axial section 1 . 2 .

[0077] Figure 8g A seventh assembly step is shown, wherein: Figure 8b The preassembled rotor shaft 5 shown in the figure is assembled with the valve needle 4 of the valve body bushing 1. The assembly is achieved by screwing the threaded shank 5.1 of the rotor shaft 5 into the internal thread of the valve needle 4. In the process, the ball bearing 6 is positioned on the bearing seat formed in the valve body bushing 1.

[0078] like Figure 8h As shown in FIG. 1 , the ball bearing 6 positioned in the valve body bushing 1 is fixed at the arrow position by the edge flange of the upper edge of the valve body bushing 1 so as to avoid rotation or displacement.

[0079] like Figure 8i The next step shown in , can provide for the magnetization of the magnets 5 . 2 formed on the rotor shaft 5 . This method step is not absolutely necessary at this point and can be performed at another point in the assembly sequence.

[0080] Figure 8j The tenth method step for assembling the valve device according to the invention is shown, wherein the valve component arrangement preassembled from the components of the spindle drive and the valve body bushing 1 is received in the capsule element 7. As shown in the cross-sectional view, the end of the rotor shaft 5 is received by the sliding bearing 12 arranged on the bottom of the capsule element, so that the rotor shaft 5 is then rotatably supported by two bearing positions. The insertion depth of the valve body bushing 1 reaches the circumferentially formed stop rib 1.3, so that the first axial section 1.1 of the valve body bushing 1 protrudes out of the capsule element 7.

[0081] Figure 8k An eleventh assembly step is shown, in which a fastening plate 16 is guided on the capsule element 7. For this purpose, the fastening plate 16 has a centrally formed opening, and on the side facing the valve block 2, the fastening plate 16 has a support stud 16.2, which is provided for supporting or bearing the fastening plate 16 on the collar 7.1 of the capsule element 7. The support stud 16.2 additionally serves as a spacing element and for the transmission of forces.

[0082] also, Figure 8l A twelfth assembly step of the valve device according to the invention is shown, in which seals 13 . 1 and 17 . 1 in the form of O-rings are arranged in grooves 13 and 17 provided for this purpose in the first axial section 1 . 1 .

[0083] Next, as in Figure 8m As shown in FIG. 1 , the sealing ring 15 is inserted into the structure of the actuator 8 receiving the capsule element 7. Finally, Figure 8n , which shows that the capsule element 7 is received in the structure of the actuator 8. It is clear that the fastening plate 16 also serves as a stop plate or holder for the actuator 8. The actuator 8 has a screw passage corresponding to the screw passage 16.1 of the fastening plate 16, so that the screw 8.1 can be screwed into the valve block 2 through the screw passage of the actuator 8 and the screw passage 16.1 of the fastening plate 16.

[0084] Industrial Applicability

[0085] The invention relates to a valve device for operation with a refrigerant, in particular for operation in a heat pump system of a motor vehicle air conditioning system, in which system carbon dioxide, CO2 (R744) or 2,3,3,3-tetrafluoropropene (R1234yf) is used as refrigerant.

Claims

1. A valve device for operating with a refrigerant, in particular for operating with a refrigerant in a heat pump system of a motor vehicle, the valve device comprising: a valve body bushing (1), the valve body bushing (1) having a first axial section (1.1) arranged to be inserted into a valve block (2), a valve body chamber (3) being formed in the valve body bushing (1), the valve body chamber (3) having a valve needle (4) axially guided therein; a spindle drive, the spindle drive having a magnetized rotor shaft (5), the rotor shaft (5) being supported by an anti-friction bearing (6) and coupled to the valve needle (4), so that rotation of the rotor shaft (5) causes axial movement of the valve needle (4) in the valve body bushing (1); and a capsule element (7), the capsule element (7) being open on one side, the spindle drive and a second axial section (1.2) of the valve body bushing (1) being received in the capsule element (7), wherein, The capsule element (7) can be fastened to the valve block (2) by means of an actuator (8) receiving the capsule element (7) for driving the rotor shaft (5), so that the first axial section (1.1) is received in the valve block (2) in a fluid-tight manner.

2. The valve device according to claim 1, characterized in that The opening of the capsule element has a stepped edge in the form of a capsule element collar (7.1) pointing radially outwards, which cooperates with the superimposed sleeve element (14, 16) for fastening the capsule element (7).

3. The valve device according to claim 2, characterized in that The sleeve element is a threaded ring (14) with an external thread (22), which is guided on the capsule element (7) and can be screwed to an internal thread (23) formed in the valve block (2) while being supported on the capsule element shaft ring (7.1) of the capsule element (7) in order to fasten the capsule element (7), wherein a seal, preferably a metal convex round seal (19), is arranged between the axially aligned end face of the capsule element shaft ring (7.1) and the valve block (2).

4. The valve device according to claim 2, characterized in that A fastening plate (16) having at least two screw passages (16.1) can be used as the sleeve element, which is guided on the capsule element (7) for fastening the capsule element (7) and can be screwed to the valve block (2) while being supported on the shaft ring (7.1), wherein a corrosion protection element (18), preferably in the form of an O-ring, is arranged between the fastening plate (16) and the valve block (2).

5. The valve device according to claim 4, characterized in that The fastening plate (16) serves as a retainer for fastening the actuator (8).

6. Valve device according to any one of the preceding claims, characterized in that The anti-friction bearing (6) is received in the valve body bushing (1) and is preferably fixed by edge flanging.

7. Valve device according to any one of the preceding claims, characterized in that The capsule element (7) has a sliding bearing (12) which serves as an additional bearing for the rotor shaft (5).

8. Valve device according to any one of the preceding claims, characterized in that The valve body bushing (1) has a stop rib (1.3) which is formed on the outer circumference and which limits the axial insertion depth into the capsule element (7).

9. Valve device according to any one of the preceding claims, characterized in that The valve needle (4) has at least one groove (4.1) formed on the outer circumference and having a seal for internal sealing relative to the valve body bushing (1).

10. Valve device according to the preceding claim, characterized in that At least one of the seals is formed as a combined seal (9) having an O-ring (9.2) and a PTFE ring (9.1), the PTFE ring (9.1) being arranged on the O-ring (9.2) and pointing radially outwards.

11. Valve device according to any one of the preceding claims, characterized in that The valve body bushing (1) has at least one groove (13, 17) in the first axial section (1.1), preferably in the area of ​​the head end, which is formed on the outer circumference and has a seal (13.1, 17.1) for internal sealing relative to the valve block (2).

12. Valve device according to any one of the preceding claims, characterized in that The valve body bushing (1) has different shank diameters in the first axial section (1.1), wherein each shank diameter has at least one groove (13, 17), which is formed on the outer circumference and has a seal (13.1, 17.1) for internal sealing relative to the valve block (2).

13. Valve device according to any one of the preceding claims, characterized in that The valve body bushing (1) has at least one groove (21) in the second axial section (1.2), the at least one groove (21) being formed on the outer circumference and having a sealing ring (21.1) for internal sealing relative to the capsule element (7).

14. Valve device according to any one of the preceding claims, characterized in that A guide disk (11) is pressed into the valve body bushing (1), wherein the guide disk (11) has an opening cross section for receiving the valve needle (4) and axially guides the valve needle (4).

15. Valve device according to any one of the preceding claims, characterized in that A seal in the form of a sealing ring (15) is arranged between the capsule element (7) and the actuator (8).

16. Valve device according to any one of the preceding claims, characterized in that The valve body bushing (1) and the valve needle (4) are formed so that a pressure bypass to the valve body chamber (3) exists in the closed state of the valve device.

17. Valve device according to the preceding claim, characterized in that When using the refrigerant R744, the free diameter for pressure equalization in the pressure bypass increases.

18. Valve device according to any one of the preceding claims, characterized in that The diameter of the valve needle for use with refrigerant R744 is dimensioned to be smaller than the diameter of the valve needle for use with refrigerant R1234yf / R134a.

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