Abstract
A method for mounting a valve needle and a bearing bush in an expansion valve for an air conditioning system may including providing a bearing bush and providing a valve needle. The bearing bush may include a circumferential wall. The valve needle may include a mounting groove having two groove flanks and a groove base. The method may also include forming a needle-bush arrangement in which the bearing bush may be received in the mounting groove via one of (i) axial sliding-in the valve needle into the bearing bush and (ii) axial sliding-on the bearing bush onto the valve needle. The method may further include mounting the needle-bush arrangement in a mounting bore of the expansion valve, which may include (i) forming a press fit between the circumferential wall and the mounting bore, and/or (ii) forming a clearance fit between the groove base and the bearing bush.
Claims
1. A method for mounting a valve needle and a bearing bush in an expansion valve for an air conditioning system, comprising: providing the bearing bush, the bearing bush extending in an axial direction and including a circumferential wall in which a slit-like opening is disposed, the slit-like opening extending along the axial direction; providing the valve needle, the valve needle extending along the axial direction, the valve needle including a mounting groove disposed at an axial end portion of the valve needle and extending along a circumferential direction of the valve needle, the mounting groove including two groove flanks disposed opposite one another in the axial direction and a groove base arranged between the two groove flanks; forming a needle-bush arrangement in which the bearing bush is received in the mounting groove of the valve needle via at least one of (i) axial sliding-in the valve needle into the bearing bush and (ii) axial sliding-on the bearing bush onto the valve needle; mounting the needle-bush arrangement in a mounting bore of the expansion valve; and wherein mounting the needle-bush arrangement in the mounting bore includes: forming a press fit between the circumferential wall of the bearing bush and the mounting bore; and forming a clearance fit between the groove base of the mounting groove and the bearing bush.
2. The method according to claim 1, wherein: the bearing bush has a bush outer diameter which is greater than a mounting inner diameter of the mounting bore of the expansion valve; and mounting the needle-bush arrangement in the mounting bore of the expansion valve includes axial pressing-in and forcing the bearing bush with the valve needle along the axial direction into the mounting bore of the expansion valve to form the press fit.
3. The method according to claim 1, wherein: the bearing bush extends in the axial direction over a bush length; the mounting groove of the valve needle extends in the axial direction over a groove width; the groove width is greater than the bush length; and mounting the needle-bush arrangement includes forming an axial play of the valve needle relative to the bearing bush.
4. The method according to claim 3, further comprising: providing the mounting bore of the expansion valve with a preload element; and while mounting the needle-bush arrangement, generating a preload force with the preload element, the preload force axially acting on the valve needle and against which the valve needle is moveable in the axial play relative to the bearing bush.
5. The method according to claim 1, wherein: the valve needle includes a shoulder that defines at least one of the two groove flanks of the mounting groove; the shoulder has a shoulder diameter which is greater than a bush inner diameter of a bush interior delimited by the circumferential wall of the bearing bush; and the at least one of (i) axial sliding-in the valve needle into the bearing bush and (ii) axial sliding-on the bearing bush onto the valve needle, includes pressing-in in the axial direction such that the shoulder, along the axial direction, is forced through the bush interior of the bearing bush.
6. The method according to claim 4, wherein generating the preload force includes introducing the preload force on a ledge of a shoulder of the valve needle facing away from the bearing bush and into the valve needle.
7. The method according to claim 5, further comprising providing an introduction bevel on an axial front side of the bearing bush such that the introduction bevel faces at least one of towards the bush interior and towards an outer lateral surface of the bearing bush.
8. The method according to claim 5, further comprising providing an introduction bevel on the shoulder of the valve needle.
9. The method according to claim 1, further comprising providing an introduction bevel on an edge of the mounting bore edging the mounting bore.
10. The method according to claim 1, further comprising spreading open the slit-like opening of the bearing bush during the at least one of (i) axial sliding-in the valve needle into the bearing bush and (ii) axial sliding-on the bearing bush onto the valve needle.
11. The method according to claim 1, further comprising narrowing the slit-like opening of the bearing bush during the mounting of the needle-bush arrangement in the mounting bore of the expansion valve.
12. The method according to claim 1, further comprising, prior to forming the needle-bush arrangement, widening the bearing bush such that the slit-like opening of the bearing bush is plastically spread open.
13. The method according to claim 1, wherein, during the mounting of the needle-bush arrangement in the mounting bore of the expansion valve, the slit-like opening is completely closed such that in a mounted state of the valve needle and of the bearing bush in the expansion valve the slit-like opening of the bearing bush is completely closed.
14. The method according to claim 1, further comprising providing the mounting bore of the expansion valve on a hollow shaft of a rotor of the expansion valve that is moveable along the axial direction via a driving device and rotatable about the axial direction.
15. The method according to claim 1, wherein the bearing bush is composed of a bush material that includes at least one of (i) a spring steel, (ii) a stainless steel with spring properties, and (iii) a copper alloy with spring properties.
16. An expansion valve, comprising the valve needle and the bearing bush mounted via the method of claim 1.
17. The method according to claim 1, further comprising elastically spreading open the slit-like opening of the bearing bush during the at least one of (i) axial sliding-in the valve needle into the bearing bush and (ii) axial sliding-on the bearing bush onto the valve needle.
18. The method according to claim 1, further comprising elastically narrowing the slit-like opening of the bearing bush during the mounting of the needle-bush arrangement in the mounting bore of the expansion valve.
19. The method according to claim 1, further comprising plastically narrowing the slit-like opening of the bearing bush during the mounting of the needle-bush arrangement in the mounting bore of the expansion valve.
20. A method of mounting a valve needle and a bearing bush in an expansion valve for an air conditioning system, comprising: providing the bearing bush, the bearing bush extending in an axial direction and including a circumferential wall in which a slit-like opening is disposed, the slit-like opening extending along the axial direction; providing the valve needle, the valve needle extending along the axial direction, the valve needle including a circumferential mounting groove disposed at an axial end portion of the valve needle, the mounting groove including two groove flanks disposed opposite one another in the axial direction and a groove base extending between the two groove flanks; arranging a coil spring in a mounting bore of the expansion valve; engaging the bearing bush in the mounting groove of the valve needle to form a needle-bush arrangement via at least one of (i) axial sliding the valve needle into the bearing bush and (ii) axial sliding the bearing bush onto the valve needle; mounting the needle-bush arrangement in the mounting bore of the expansion valve such that the valve needle is disposed with axial play relative to the bearing bush; and wherein mounting the needle-bush arrangement in the mounting bore includes: generating, via the coil spring, a preload force that acts axially on the valve needle; forming a press fit between the circumferential wall of the bearing bush and the mounting bore; and forming a clearance fit between the groove base of the mounting groove and the bearing bush.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] It shows, in each case schematically:
[0028] FIG. 1 shows a flow diagram of an example of a method according to the invention for mounting a valve needle and a bearing bush in an expansion valve for an air conditioning system,
[0029] FIG. 2 shows a snapshot during the carrying out of the method of FIG. 1, exemplarily a sliding-in of the valve needle into the bearing bush or a sliding-on of the bearing bush onto the valve needle,
[0030] FIG. 3 shows a snapshot during the carrying out of the method of FIG. 1, exemplarily a needle-bush arrangement, which is formed as a consequence of the sliding-in or sliding-on shown in FIG. 2,
[0031] FIG. 4 shows a snapshot during the carrying out of the method according to FIG. 1, in a longitudinal section along an axial direction, an expansion valve with a mounting bore for receiving the needle-bush arrangement of FIG. 3,
[0032] FIG. 5 shows a longitudinal section along the axial direction, exemplarily an expansion valve according to the invention with the mounted valve needle and bearing bush after the carrying out of the method according to FIG. 1.
DETAILED DESCRIPTION
[0033] FIG. 1 shows a flow diagram of an example of a method 1 according to the invention for mounting a valve needle 2 and a bearing bush 3 in an expansion valve EV for an air conditioning system. Such an expansion valve EV can be installed for example in an air conditioning system of a motor vehicle.
[0034] In the FIGS. 2 and 3, snapshots during the carrying out of the method 1 according to FIG. 1 are exemplarily shown. Here, a sliding-in of the valve needle 2 into the bearing bush 3 or a sliding-on of the bearing bush 3 onto the valve needle 2 are shown in FIG. 2 and a needle-bush arrangement 10 in FIG. 3, which is formed as a consequence of the sliding-in or sliding-on shown in FIG. 2. As is exemplarily understandable by way of the FIGS. 2 and 3, the bearing bush 3 that can be mounted by means of the method 1 according to the invention extends along an axial direction A and has a circumferential wall 4. The axial direction A can run on a centre longitudinal axis of the bearing bush. From the axial direction A, a radial direction R can extend away perpendicularly. A circumferential direction U can circulate round about the centre longitudinal axis M and extend perpendicularly to the axial direction A and to the radial direction R. In the circumferential wall 4 a slit-like opening 5 is formed, which extends along the axial direction A. According to the examples of FIGS. 2 and 3, the bearing bush 3 can be embodied with a slit-like opening 5 running along the axial direction A, which completely separates the circumferential wall 4 of the bearing bush 3 along the axial direction A. However, the slit-like opening 5 can also be formed so as to only partially sever the circumferential wall 4 of the bearing bush 3 in the axial direction 4, which is not shown. Furthermore, multiple slit-like openings 5 can also be provided in the circumferential wall 4 of the bearing bush 3, which in each case only penetrate one of the front faces 19 of the bearing bush 3. The valve needle 2 likewise extends along an axial direction A. The valve needle 2 comprises an axial end portion 6 in which a mounting groove 7 extending along the circumferential direction U of the valve needle 2 is present. This mounting groove 7 comprises two groove flanks 8a, 8b located opposite one another in the axial direction A. Between the groove flanks 8a, 8b located opposite one another a groove base 9 of the mounting groove 7 is formed.
[0035] According to the example of FIG. 1, the method comprises a first measure a), according to which the bearing bush 3 is provided. In a measure c1), the bearing bush 3 can be expanded so that the slit-like opening 5 of the bearing bush 3 is elastically spread open. Furthermore, the method comprises a measure b) which provides that the valve needle 2 is provided. In a further measure c), an axial sliding-in of the valve needle 2 into the bearing bush 3 or an axial sliding-on of the bearing bush 3 onto the valve needle 2 takes place.
[0036] By means of this sliding-in or sliding-on, which is exemplarily illustrated as snapshot in FIG. 2, a needle-bush arrangement 10 is formed. The axial sliding-in of the valve needle 2 into the bearing bush 3 or the axial sliding-on of the bearing bush 3 onto the valve needle 2 according to measure c) can take place by means of a pressing-in P in the axial direction A. During the axial sliding-in of the valve needle 2 into the bearing bush 3 or during the axial sliding-on of the bearing bush 3 onto the valve needle 2, the slit-like opening 5 of the bearing bush 3 running in the axial direction A can be spread open. Such a spreading-open of the slit-like opening 5 can take place elastically and/or plastically.
[0037] The resulting needle-bush arrangement 10 is exemplarily illustrated in FIG. 3. In the needle-bush arrangement 10, the bearing bush 3 is received in the mounting groove 7 of the valve needle 2.
[0038] According to FIG. 1, the method according to the invention additionally comprises a measure d), according to which the needle-bush arrangement 10 is mounted in a mounting bore 11 of an expansion valve EV provided for this purpose. This means that the valve needle 2 and the bearing bush 3 are jointly mounted in the mounting bore 11.
[0039] According to the measure d), the needle-bush arrangement 10 is mounted so that a mounted state of the expansion valve EV illustrated in FIG. 5 is formed. In this mounted state of the expansion valve EV, a press fit 12 is formed between the circumferential wall 4 of the bearing bush 3 and the mounting bore 11 of the expansion valve EV. Between the groove base 9 of the mounting groove 7 and the bearing bush 3, a clearance fit 13 is formed in the mounted state. The mounting of the needle-bush arrangement 10 in the mounting bore 11 of the expansion valve according to measure d) for creating the mounted state, can take place in the manner of an axial pressing-in P.
[0040] There, corresponding to the example of FIG. 4, the bearing bush 3 can have a bush outer diameter D1, which is greater than a mounting inner diameter D2 of the mounting bore 11 of the expansion valve EV. Accordingly, when carrying out the measure d), the bearing bush 3 together with the valve needle 2 arranged in the bearing bush 3, can be forced along the axial direction A into the mounting bore 11 of the expansion valve EV for forming the press fit 12 between the circumferential wall 4 of the bearing bush 3 and the mounting bore 11. The bearing bush 3 provided in measure a) can extend in the axial direction A over a bush length L. The mounting groove 7 of the valve needle 2 provided in measure b) can extend in the axial direction A over a groove width B. The groove width B can be greater than the bush length L.
[0041] In the FIGS. 4 and 5 it is shown that in the mounting bore 11 of the expansion valve EV a preload element 14 is provided. According to the examples shown, such a preload element 14 can be a coil spring element 15 embodied as coil spring. During the mounting of the needle-bush arrangement 10 according to the measure d), a preload force FV axially acting on the valve needle 2 can be generated by means of the preload element 14. During the mounting of the needle-bush arrangement 10 according to the measure d), an axial play S of the valve needle 2 can be formed relative to the bearing bush 3 as shown in FIG. 5.
[0042] In the mounted state shown in FIG. 5, the valve needle 2 can be moveable in its axial play S relative to the bearing bush 3 against the preload force FV. By means of the preload force FV of the preload element 14, a bringing-into-contact of the valve needle 2 with a valve seatnot shown in the figurescan be cushioned. Such a cushioning can take place over a distance of the play S.
[0043] On the valve needle 2 a shoulder 16 can be present, on which one of the groove flanks 8a, 8b of the mounting groove 7 is arranged. As shown in FIG. 4, the shoulder 16 of the valve needle 2 can be embodied with a shoulder diameter D3. The shoulder diameter D3 can be greater than a bush inner diameter D4 of a bush interior 17 of the bearing bush 3 delimited by the circumferential wall 4 of the bearing bush 3. Accordingly, when carrying out the measure c), the shoulder 18 can be forced along the axial direction A through the bush interior of the bearing bush 3.
[0044] As is evident in FIG. 5, the preload force FV of the preload element 14 can be introduced, during the mounting of the needle-bush arrangement 10 in the mounting bore 11 of the expansion valve EV, on a ledge 18 of the shoulder 16 of the valve needle 2 into the valve needle 2, wherein the ledge 18 of the shoulder 16 can be facing away from the bearing bush 3. In the mounted state, the preload force FV of the preload element 14 can be introduced into the valve needle 2 on the ledge 18 of the shoulder 16 of the valve needle 2 facing away from the bearing bush 3.
[0045] As illustrated in FIG. 4, an introduction bevel 21 can be provided on an axial front side 19 of the bearing bush 3 towards the interior 17. Alternatively or additionally, an introduction bevel 21 can also be provided on the axial front side 19 towards an outer lateral surface 20 of the bearing bush 3. One of the two front sides 19 of the bearing bush 3 can be embodied with an introduction bevel 21 towards the bush interior 17 and the other front side 19 of the bearing bush 3 located opposite can be provided with an introduction bevel towards the outer lateral surface 20 of the bearing bush 3. Alternatively it is also possible to provide an introduction bevel with front sides 19 of the bearing bush 3 both towards the outer lateral surface 20 and also towards the interior 17, which however is not shown in the figures. On the shoulder 16 of the valve needle 2 an introduction bevel 21 can likewise be provided. This introduction bevel 21 on the shoulder 16 of the valve needle 2 can be present on the shoulder 18 of the bevel 16 of the valve needle 2 facing away from the bearing bush 3. On an edge 22 of the mounting bore 11 edging the mounting bore 11 of the expansion valve EV, an introduction bevel 21 can likewise be provided.
[0046] When mounting the needle-bush arrangement 10 in the mounting bore 11 of the expansion valve EV according to measure d), the axially running slit-like opening 5 of the bearing bush 3 can be narrowed, so that the slit-like opening 5 of the bearing bush 3 is narrowed in the mounted state shown in FIG. 5. Such a narrowing of the slit-like opening 5 in measure d) can take place elastically and/or plastically. The bearing bush 3 provided in measure a) can be embodied so that the slit-like opening 5 during the mounting of the needle-bush arrangement 10 in the mounting bore 11 of the expansion valve EV for creating the mounted state can be closed. Here, the slit-like opening 5 can be completely closed. In the mounted state of the valve needle 2 and the bearing bush 3 in the expansion valve EV, the slit-like opening 5 of the bearing bush 3 can be closed. The slit-like opening 5 can be completely closed in the mounted state.
[0047] According to the examples of FIGS. 4 and 5, the mounting bore 11 of the expansion valve EV, into which the needle-bush arrangement 10 is forced according to measure d), can be provided on a hollow shaft 23. This hollow shaft 23 can be provided on a rotor 24 of the expansion valve EV. The rotor 24 with the hollow shaft 23 can be moveable by means of a driving device along the axial direction A and rotatable about the axial direction A. The mounting bore 11 can be a blind hole. The preload element 14 can be axially supported on a base of the mounting bore 11 embodied as blind hole. The preload element 14 can be supported on the base of the mounting bore 11 embodied as blind hole by a sphere. This sphere can have an outer diameter matched to the mounting inner diameter D2 of the mounting bore 11.
[0048] Alternatively to the formation of the mounting bore 11 as blind hole shown in the FIGS. 4 and 5, the mounting bore can also be a through-bore, wherein for axially supporting the preload element 14 a narrowing of the mounting inner diameter D2 can be provided. The bearing bush 3 provided in measure a) can be formed from a bush material. This bush material of the bearing bush 3 can comprise a spring steel or stainless steel with spring properties. Such a spring steel or stainless steel with spring properties can in particular be a steel designated 1.4310 according to DIN EN 10088. Furthermore, the bush material of the bearing bush 3 can alternatively or additionally comprise a copper alloy with spring properties.
[0049] FIG. 5, furthermore, shows as part view an example of an expansion valve EV according to the invention in a longitudinal section along the axial direction A with a valve needle 2 and a bearing bush 3, which are mounted by means of the method one described above.
