INSERT FOR A THERMOSTATIC EXPANSION VALVE, THERMOSTATIC EXPANSION VALVE AND METHOD FOR ASSEMBLING A THERMOSTATIC EXPANSION VALVE

Abstract

The invention relates to an insert (1) for a thermostatic expansion valve as a thermostatic expansion valve (2) comprising such an insert and to a method of assembling such a thermostatic expansion valve (2). The insert (1) comprises an expansion valve element (3) and an expansion valve seat (4). The expansion valve element (3) is held inside the insert (1) by a biasing member (5), wherein the insert (1) is structured and arranged to be inserted into a valve housing (8). The task of the invention is to provide an insert for a thermostatic expansion valve that allows a simple assembly of the valve and also provides an improved functionality. The task is solved in that the insert (1) further comprises a control valve (12), wherein the control valve (12) is located in the same flow path through the insert (1) as the expansion valve seat (4).

Claims

1. An insert for a thermostatic expansion valve comprising an expansion valve element and an expansion valve seat, wherein the expansion valve element is held inside the insert by a biasing member, wherein the insert is structured and arranged to be inserted into a valve housing, wherein the insert further comprises a control valve, wherein the control valve is located in the same main flow path through the insert as the expansion valve seat.

2. The insert according to claim 1, wherein the control valve comprises a solenoid valve.

3. The insert according to claim 2, wherein the control valve further comprises a main valve, wherein the solenoid valve is a pilot valve controlling the opening and closing of the main valve.

4. The insert according to claim 1, wherein the control valve is located upstream of the expansion valve seat in the main flow path.

5. The insert according to claim 4, wherein the insert comprises an insert inlet from which the main flow path leads to the control valve.

6. The insert according to claim 5, wherein the main flow path continues from the control valve to the expansion valve seat, wherein the expansion valve seat also forms an insert outlet.

7. The insert according to claim 1, wherein the expansion valve element 3 comprises an engagement surface that is arranged to be engaged by an actuator that is external to the insert.

8. A thermostatic expansion valve comprising an insert according to claim 1, as well as a valve housing, wherein the valve housing comprises a valve inlet and a valve outlet.

9. The thermostatic expansion valve according to claim 8, wherein the thermostatic expansion valve further comprises an actuator to engage the expansion valve element.

10. The thermostatic expansion valve according to claim 9, wherein the actuator comprises a stem to engage the engagement surface of the expansion valve element.

11. The thermostatic expansion valve according to claim 8, wherein the actuator comprises two pressure chambers separated by a diaphragm, wherein a first pressure chamber is connected to a pressure port of the valve housing and a second pressure chamber is connected to a temperature sensing bulb.

12. A method for assembling a thermostatic expansion valve comprising the steps: Providing a valve housing comprising a valve inlet, a valve outlet as well as an actuator, Providing an insert according to claim 1, Inserting the insert into a predetermined opening of the valve housing, such that the actuator comes into engagement with the expansion valve element in the insert, Fixing the insert to the valve housing.

13. The insert according to claim 2, wherein the control valve is located upstream of the expansion valve seat in the main flow path.

14. The insert according to claim 3, wherein the control valve is located upstream of the expansion valve seat in the main flow path.

15. The insert according to claim 2, wherein the expansion valve element 3 comprises an engagement surface that is arranged to be engaged by an actuator that is external to the insert.

16. The insert according to claim 3, wherein the expansion valve element 3 comprises an engagement surface that is arranged to be engaged by an actuator that is external to the insert.

17. The insert according to claim 4, wherein the expansion valve element 3 comprises an engagement surface that is arranged to be engaged by an actuator that is external to the insert.

18. The insert according to claim 5, wherein the expansion valve element 3 comprises an engagement surface that is arranged to be engaged by an actuator that is external to the insert.

19. The insert according to claim 6, wherein the expansion valve element 3 comprises an engagement surface that is arranged to be engaged by an actuator that is external to the insert.

20. The thermostatic expansion valve comprising an insert according to claim 2, as well as a valve housing, wherein the valve housing comprises a valve inlet and a valve outlet.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Preferred embodiments of the invention will now be described with reference to the Figures, wherein:

[0026] FIG. 1A shows a thermostatic expansion valve according to the state of the art,

[0027] FIG. 1B shows an insert as used in the thermostatic expansion valve according to FIG. 1A,

[0028] FIG. 2 shows an insert according to the invention with closed main and pilot valves,

[0029] FIG. 3 shows a thermostatic expansion valve comprising an insert according to FIG. 2 with a closed main and pilot valve,

[0030] FIG. 4 shows a detail of a thermostatic expansion valve according to FIG. 3,

[0031] FIG. 5 +6 show the thermostatic expansion valve according to FIGS. 3 and 4 with open main and pilot valves.

DETAILED DESCRIPTION

[0032] FIG. 1A and 1B show for comparison the state of the art of an insert 101 as well as a thermostatic expansion valve 102 comprising such an insert 101. The insert 101 comprises an expansion valve element 103 as well as an expansion valve seat 104. The expansion valve element 103 is biased by a biasing member 105 against the expansion valve seat 104, in this case a spring. The insert 101 furthermore comprises an insert inlet 106 as well as an insert outlet 107. The expansion valve seat 104 is in this embodiment arranged at the insert outlet 107. At the insert inlet 106 a strainer 131 is arranged.

[0033] The thermostatic expansion valve 102 furthermore comprises a valve housing 108 in which a valve inlet 109 as well as a valve outlet 110 is arranged.

[0034] The thermostatic expansion valve 102 also comprises an actuator 111 to actuate the expansion valve element 103. The insert 101 furthermore comprises a strainer 131 arranged near the insert inlet 106.

[0035] FIGS. 2 to 6 show the same preferred embodiment of the invention, where FIGS. 2 to 4 show the insert and the expansion valve comprising the insert with a closed control valve while FIGS. 5 and 6 show the same embodiment with an open control valve. Corresponding features will be denoted with the same reference signs.

[0036] According to the invention the insert 1 to be inserted into a thermostatic expansion valve 2 comprises an expansion valve element 3 as well as an expansion valve seat 4. The expansion valve element 3 is biased against the expansion valve seat 4 by a biasing member 5.

[0037] The insert 1 further comprises an insert inlet 6 as well as an insert outlet 7. The insert outlet 7 here is arranged in the same opening in which the expansion valve seat 4 is arranged. At the insert inlet 6 a strainer 31 is arranged.

[0038] In FIGS. 3 to 5 the insert 1 is arranged in a thermostatic expansion valve 2 comprising a valve housing 8. The valve housing 8 comprises a valve inlet 9 as well as a valve outlet 10. Fluid coming from the valve inlet 9 flows to the insert inlet 6 towards a control valve 12. The control valve 12 comprises a solenoid valve 13, which in this case acts as a pilot valve. The solenoid valve 13 comprises a coil 14, an anchor core 15 as well as an armature 16. The armature 16 is connected to a pilot valve element 17 which in all FIGS. 2 to 6 engages a pilot valve seat 18. The control valve 12 furthermore comprises a main valve, comprising a main valve element 19 as well as a main valve seat 20. The pilot valve seat 18 is arranged on one end of a channel leading through the main valve element 19. A servo piston 32 is arranged coaxially around the main valve element 19.

[0039] When the solenoid valve 13 is activated the armature 16 as well as the pilot valve element 17 will be moved downwards and away from the main valve element 19. Thereby a fluid path through the main valve element 19 is opened. Furthermore, a pressure difference is created across the top and bottom side of the servo piston 32. This results in a pressure force that moves the servo piston 32 towards the solenoid valve 13 until the servo piston 32 abuts the main valve element 19 and pulls the main valve element 19 also towards the solenoid valve 13. Thereby, the main valve of the control valve 12 is opened. This situation can be seen in FIGS. 5 and 6.

[0040] If the expansion valve element 3 does not engage the expansion valve seat 4 the fluid can then flow through the expansion valve towards the valve outlet 10 and, for example, towards an external evaporator.

[0041] The thermostatic expansion valve 2 furthermore comprises an actuator 11, which in this case takes the form of a capsule. The actuator 11 comprises a diaphragm 22 which is at its radial outer ends fixed to the valve housing 8. The diaphragm 22 separates a first pressure chamber 23 from a second pressure chamber 24. The first pressure chamber 23 is connected to a pressure port 25 which allows to change the pressure in the first pressure chamber 23 to adjust the opening behavior of the thermostatic expansion valve 2.

[0042] The second pressure chamber 24 is connected to a temperature sensing bulb 26. The temperature sensing bulb 26 can be connected, for example, to an outlet of an external evaporator to readjust the opening degree of the thermostatic expansion valve 2 according to the state of the refrigerant exiting the evaporator.

[0043] The actuator 11 furthermore comprises a spring 27 which acts as a biasing member inside the first pressure chamber 23. The diaphragm 22 is connected both to the spring 27 as well as to a stem 28. The stem 28 engages the expansion valve element 3 at an engagement surface 29.

[0044] When the insert 1 is introduced into the valve housing 8 the expansion valve element 3 is brought into contact with the actuator 11, in particular at the end of the stem 28. At the same time the insert 1 is fixed to the valve housing 8 by a connection geometry 30, for example a screw connection.

[0045] The insert 1 according to the invention consequently allows to assemble a thermostatic expansion valve 2 in a simplified manner while still providing the functionality of a thermostatic expansion valve as well as of a control valve 12 which provides a direct control of the flow through the thermostatic expansion valve 2. Moreover, the invention also provides a simplified method of assembly of a thermostatic expansion valve.

[0046] While the present disclosure has been illustrated and described with respect to a particular embodiment thereof, it should be appreciated by those of ordinary skill in the art that various modifications to this disclosure may be made without departing from the spirit and scope of the present disclosure.