EXPANSION VALVE

Abstract

The invention relates to an expansion valve (10), for controlling a fluid flow, having a valve means housing (12) and at least one valve means (16), which is movably arranged in a valve means housing (12), and an actuator housing (14), in which the electrical drive of the expansion valve (10) is arranged, wherein the valve means housing (12) is formed substantially at least in part of a metal, in particular of aluminum, and wherein the actuator housing (14) is formed substantially at least in part of plastic and wherein the actuator housing (14) is secured on the valve means housing (12) by means of at least one connection element (40). According to the invention, the connection element (40) is formed at least in part as a latching element and/or clip element.

Description

BACKGROUND OF THE INVENTION

The invention is based on an expansion valve.

It is already known to arrange an actuator housing on a valve means housing in an expansion valve by means of a screw connection. Such a connection is however subject to a plurality of space-induced restrictions.

The invention is based on an expansion valve for controlling a fluid flow, having a valve means housing and at least one valve means which is movably arranged in the valve means housing, and an actuator housing in which the electric drive of the expansion valve is arranged, wherein the valve means housing is substantially formed at least partly of a metal, in particular of aluminum, and wherein the actuator housing is substantially formed at least partly of plastic, and wherein the actuator housing is secured on the valve means housing by means of at least one connecting element. It is proposed that the connecting element is formed at least partly as a latching element and additionally or alternatively as a clip element.

SUMMARY OF THE INVENTION

The expansion valve according to the invention has the advantage that a simple and economic connection can be established between the actuator housing and the valve means housing. The actuator housing can be mounted on the valve means housing particularly easily by means of the connecting element according to the invention. Furthermore, the installation space necessary for the connection may be reduced. The connecting element according to the invention here allows a connection of different expansion valve variants without additional adaptation. The connecting element according to the invention is here advantageously able to provide a simple and secure connection between two components of different materials.

In an expansion valve of the type concerned here, the fluid is at least partially present in a gaseous phase in the through-flow region of the valve means housing, wherein high pressures may prevail in the range between 1-30 bar and briefly up to 100 bar. Because of these thermodynamic peripheral conditions, such a valve means block is made of a metal, preferably aluminum or an aluminum alloy. It is however also conceivable that at least one housing part of the valve means housing has a plastic body with a diffusion-inhibiting barrier layer containing metal. Such a valve means housing can be produced simply and economically in comparison with an aluminum block housing. At the same time, because of the gas-tightness of the expansion valve according to the invention, it may be used in fluid circuits in which the fluid is at least partially present in a gaseous phase. The actuator housing in which the electric drive is arranged is subjected to different peripheral conditions with respect to tightness and functionality, so that this is made at least partially of plastic.

A fluid of the type concerned here is a heat transfer medium which circulates within the fluid circuit. In particular, the fluid is a natural refrigerant, such as for example hydrocarbons, carbon dioxide, ammonia, propane, butane, propylene, water, or a synthetic refrigerant such as for example fluorochlorohydrocarbons or partly halogenated fluorochlorohydrocarbons.

The measures outlined in the subclaims give advantageous refinements and improvements of the independent features.

An advantageous refinement of the invention proposes that the connecting element has at least a first portion and at least a second portion, wherein the first portion at least partly engages in the valve means housing, and wherein the second portion at least in portions latches to the actuator housing, and wherein the second portion has a firtree-like toothing on its outer casing surface.

In the context of the present invention, a firtree-like toothing means an outer contour of the connecting element which has a plurality of teeth. The teeth or protrusions of the firtree-like toothing advantageously latch or catch in the receiver on the actuator housing, so that a particularly simple and secure connection of the housing can be provided. Because the actuator housing is made of plastic, the actuator housing deforms on insertion of the firtree-like toothing so that a captive connection can be provided.

According to an advantageous refinement of the invention, it is provided that the first portion of the connecting element is configured so as to be elastic in the circumferential direction. Such a connecting element which is elastic in the circumferential direction may be introduced particularly easily into the valve means housing under pretension, so that the connecting element is held in the housing because of the return force. A particularly simple and robust solution may be provided if the first portion is formed as an at least partly slotted sleeve.

According to an advantageous refinement of the invention, the second portion extends substantially in the axial direction, wherein the second portion is configured so as to be substantially flat and has an inlet chamfer on its free end facing away from the first portion. Such an inlet chamfer allows particularly simple insertion of the second portion in the actuator housing. In the context of the present invention, the axial direction of such an expansion valve means in particular the extent direction of the valve shaft on which the valve means is arranged.

According to an advantageous refinement of the invention, the connecting element engages around the valve means housing and the actuator housing in the axial direction. Preferably, here the connecting element is configured as a clamping element. By means of such a clamping element applied under pretension, a particularly simple and compact connection can be created between the actuator housing and the valve means housing.

A particularly simple and compact connecting element may be provided in particular if the connecting element is configured so as to be substantially U-shaped and has at least two legs, wherein the legs are arranged substantially parallel to one another. Preferably, the legs of the connecting element furthermore each have a free end, wherein clamping protrusions are arranged on each free end of the connecting element. In mounted state, these clamping protrusions may engage in corresponding undercuts which are provided on the valve means housing and alternatively or additionally also on the actuator housing.

A particularly economic connecting element may be provided in particular if the connecting element is configured as one piece, in particular as a punched bent part.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings depict exemplary embodiments of the expansion valve and connecting element which are explained in more detail in the description which follows. The drawings show:

FIG. 1 a perspective, exploded illustration of an expansion valve according to a first embodiment,

FIG. 2 a perspective illustration of a connecting element configured as a clamping element,

FIG. 3 a perspective illustration of a valve means housing and connecting elements arranged on the valve means housing,

FIG. 4 a perspective illustration of a connecting element according to the embodiment shown in FIG. 3.

DETAILED DESCRIPTION

In the various embodiment variants, the same parts carry the same reference signs.

FIG. 1 shows a first exemplary embodiment of an expansion valve 10 in an exploded illustration. As can be clearly seen in FIG. 1, the expansion valve 10 comprises an actuator housing 14 and a valve means housing or valve housing 12. At least one valve means or valve member 16 is arranged inside the valve means housing 12. The valve means 16 is configured so as to be movable, in particular rotatable relative to the valve means housing 16. Furthermore, the first valve means housing 12 has a through-flow region through which a fluid flows. A fluid of the type concerned here is a heat transfer medium which circulates within the fluid circuit. In particular, the fluid is a natural refrigerant, such as for example hydrocarbons, carbon dioxide, ammonia, propane, butane, propylene, water, or a synthetic refrigerant such as for example fluorochlorohydrocarbons or partly halogenated fluorochlorohydrocarbons.

The valve means housing 12 has at least two first openings 20, 22 which form an inlet and an outlet respectively for the fluid in the valve means housing 12. Because of the view selected, FIG. 1 shows only one of the two first openings 20, 22. In the embodiment of the invention shown in FIG. 1, the two openings 20, 22 are arranged inside the valve means housing 12 perpendicularly to an axial direction 18 of the expansion valve 10. The valve means housing 12 may in particular be configured as a valve means block which is configured so as to be substantially gas-tight under the thermodynamic conditions present in an expansion valve 10.

In an expansion valve 10 of the type concerned here, the fluid is at least partially present in a gaseous phase in the through-flow region of the valve means housing 12, wherein high pressures may prevail in the range between 1-30 bar and briefly up to 100 bar. Because of these thermodynamic peripheral conditions, such a valve means block 12 is made of a metal, preferably aluminum or an aluminum alloy. It is however also conceivable that at least one housing part of the valve means housing 12 has a plastic body with a diffusion-inhibiting barrier layer containing metal. Such a valve means housing 12 can be produced simply and economically in comparison with an aluminum block housing. At the same time, because of the gas-tightness of the expansion valve 10 according to the invention, it may be used in fluid circuits in which the fluid is at least partially present in a gaseous phase.

As FIG. 1 shows, an actuator housing 14 is arranged on the valve means housing 12. According to the embodiment of the invention shown in FIG. 1, the actuator housing 14 comprises two actuator housing parts 24, 26, inside which an electric drive (not shown here) is arranged. Such an electric drive may be configured in particular as a stepper motor, a brushless motor or a brush motor. The actuator housing 14 is formed substantially at least partly of plastic. In particular, the actuator housing 14 is produced by means of injection molding processes.

As well as the electric drive, according to an advantageous embodiment of the invention, a gear mechanism is arranged inside the actuator housing 14 which transmits the motion of the electric drive to a corresponding valve shaft 30. Furthermore, the actuator housing 14 contains motor electronics for controlling the electric drive. The corresponding valve means is arranged on the valve shaft 30. The valve shaft 30 passes through an opening 32 of the valve means housing 12 and extends substantially in the axial direction 18.

To seal the through-flow region of the fluid, a housing element 34 formed as a cover is arranged on the second opening 32. The housing element 34 here has a bore which is concentric to the axial direction 18 and through which the valve shaft 30 protrudes into the valve means housing 12.

According to the invention, it is now provided that the actuator housing 14 is secured to the valve means housing 14 by means of at least one connecting element 40, which is configured at least partly as a latching element and alternatively or additionally as a clip element. FIGS. 1 and 2 each show a first embodiment of such a latching or clip element.

As FIG. 1 shows, the connecting element 40 according to the embodiment of the invention shown here engages around the valve means housing 12 and the actuator housing 14 in the axial direction 18, and is configured as a clamping element. At one of its free ends 42b, the clamping element 40 has a clamping protrusion 44, and a further clamping protrusion 45 is formed by the arcuate segment 60. Preferably, the arcuate segment is part of the free end 42a, in particular the leg 58. The clamping protrusions 44, 45 engage in corresponding undercuts 46, 47 of the valve means housing 12 or actuator housing 14.

According to the embodiment of the invention shown in FIG. 1, the undercut 46 of the valve means housing 12 is configured as a recess in the valve means housing 12, extending substantially in the radial direction. Preferably, the side face 48 of the undercut 46 facing the actuator housing 14 extends substantially perpendicularly to the axial direction 18. This side face 48 in mounted state acts as an axial stop for the connecting element 40.

According to the embodiment of the invention shown in FIG. 1, at least one radially extending protrusion 50 is arranged on the actuator housing 14, and the undercut 47 of the actuator housing 14 is at least partly formed on said protrusion. On mounting of the connecting element 40, usually firstly the first clamping protrusion 44 is placed in the undercut 46 of the valve means housing 12, and then the second clamping protrusion 45 is inserted into the corresponding undercut 47 of the actuator housing 14. In order to facilitate the insertion or pressing of the second clamping protrusion 45 into the undercut 47 on the actuator housing 14, the protrusion 50 of the actuator housing 14 preferably has an inlet chamfer 52.

According to the embodiment of the invention shown in FIG. 1, the expansion valve 10 has two connecting elements 40 which are arranged on opposite sides of the expansion valve 10. Evidently however, the number and arrangement of the connecting elements 40 may vary.

FIG. 2 shows the connecting element 40 from FIG. 1 in enlarged scale. According to the embodiment of the invention shown in FIG. 2, clamping element 40 is configured so as to be substantially U-shaped, having a first middle portion 56 and legs 58, 59 which are arranged on either side of the middle portion 56 and each form the free ends 42a, b of the connecting element 40. According to the embodiment of the invention shown in FIG. 2, the legs 58, 59 of the clamping element 40 are arranged substantially parallel to one another and in mounted state extend substantially in the radial direction. In the embodiment shown in FIG. 2, the middle portion 56 of the clamping element 40 is formed flat at least in portions, and in mounted state extends substantially in the axial direction 18.

The clamping element 40 with its legs 58, 59 spans the edge region between the mutually abutting valve means housing 12 and actuator housing 14. As already explained, the clamping element comprises clamping protrusions 44, 45, which in mounted state engage in the respective undercuts 46, 47 on the valve means housing 12 and actuator housing 14. The clamping protrusion 45, which in mounted state engages in the actuator housing 14, is bent by an acute angle β with respect to the extent direction of the assigned leg 58. Suitably, the clamping protrusion 45 has an arcuate segment 60 extending in the axial direction 18, which on mounting slides over the inlet chamfer 52 before engaging in the corresponding undercut 47. The leg 59, which in mounted state engages in the valve means housing 12, is designed so as to be substantially arcuate, wherein in mounted state, the free end 42b of the arcuate leg 59 bears on the side wall 48 of the undercut 46 of the valve means housing 12. In this way, on mounting, an adequate pretension can be applied to the clamping element 40.

The connecting element 40 shown in FIG. 2 is configured as one piece. Such a connecting element 40 can be produced particularly easily by means of punching-bending processes.

The free end 42b of the clamping element 40 forms the clamping protrusion 44.

According to an advantageous refinement, the clamping element 40 has a bend over its width in the region 49. Optionally, a bend is also formed over the width in the middle portion 56. The optional bend in the region 49 is preferably reversed with respect to the optional bend in the region 56.

The end faces 51 of the free ends 42a, b have edges and/or corners which are preferably not rounded or angled. At the end faces 51, the free ends 42a, b are formed with edges and/or corners. There is no tapering towards the free ends 42a, b. The clamping protrusion 44 and the free end 42b have no taper in width. The clamping protrusion 44 and the free end 42b have edges and/or corners. The clamping protrusion 44 and the free end 42b preferably have no roundings.

The end faces 51 of the free ends 42a, b are formed rectangular. Preferably, the edges are sharp and not rounded.

Preferably, the width of the clamping element 40 is substantially constant over its entire length.

According to an advantageous refinement, the end face 51 of the free end 42b forming the clamping protrusion 44 has a concave course over its width. The two opposing edges of the end face 51 of the free end 42b, which do not point towards the middle portion 56, protrude beyond the middle in the axial direction. Preferably, in mounted state, the edges engage first in the undercut 46. This prevents for example a shifting of the clamping element 40 with respect to the actuator housing 14 along the undercut 46.

Preferably, the middle portion 56 has no kink in the axial direction.

The free end 42b forms the clamping protrusion 44. A further clamping protrusion 45 is formed by the leg 58 or the further free end 42a, in particular the arcuate segment 60.

The normal vector of the end face 51 of the free end 52b points substantially in the axial direction 18.

FIGS. 3 and 4 each show a second embodiment of a connecting element 40. FIG. 3 shows a perspective illustration of the valve means housing 12 of the expansion valve 10. As clearly evident in FIG. 3, the valve block has at least two first openings 20, 22 through which the fluid may flow in and out. Furthermore, the valve means housing 12 has a second opening 32 through which the valve shaft 30 passes. The valve means housing 12 has a substantially flat contact face 35 on which the actuator housing 14 is arranged in mounted state.

As clearly evident from FIG. 3, the connecting element 40 has at least a first portion 70 and a second portion 72 for connecting the valve means housing 12 to the actuator housing 14. The first portion 70 here at least partly engages in a corresponding bore 80 of the valve means housing 12. The second portion 72 on its outer casing surface has a firtree-like toothing 74. As clearly evident from FIG. 2, the second portion 72 of the connecting element 40 extends substantially in the axial direction 18. The first portion 70 of the connecting element 40 is configured so as to be elastic in the circumferential direction, and is held in the valve means housing 12 because of its spring force and friction. On mounting of the actuator housing 14, the second portion 72 with its firtree-like toothing 74 engages in the actuator housing 14 and latches or catches there, which allows a secure connection between the valve means housing 12 and the actuator housing 14.

According to the embodiment of the invention shown in FIG. 3, for connecting the actuator housing 14 to the valve means housing 12, two connecting elements 40 are provided, wherein the two connecting elements 40 are arranged twisted by 45° relative to one another in the circumferential direction.

Evidently however, the number and arrangement of the connecting elements 40 may vary.

FIG. 4 shows in enlarged scale a connecting element according to the embodiment shown in FIG. 3. As clearly evident from FIG. 4, the connecting element 40 has a first portion 70 and a second portion 72. The connecting element 40 extends substantially in the axial direction 18. In mounted state, the first portion 70 engages at least partly in the valve means housing 12, and the firtree-like toothing 74 arranged on the outer casing surface of the second portion 72 latches into the actuator housing 14. As already stated, the first portion 70 is configured so as to be elastic in the circumferential direction. According to the embodiment of the invention shown in FIG. 4, the second portion 70 is to this end configured as a slotted sleeve.

As shown in FIG. 4, both the slot 88 and the passage opening 90 of the slotted sleeve 70 here extend substantially in the axial direction 18. On mounting, the slotted sleeve 70 is compressed and inserted in the bore 80 of the valve means housing 12 extending in the axial direction 18. Because of the return force of the elastic sleeve, it is pressed against the bore wall of the valve means housing 12 and held there.

As is clearly evident from FIG. 4, the second portion 72 is arranged on an end face 92 of the sleeve 70. Preferably, the second portion 72 lies radially opposite the slot 88. The second portion 72 extends substantially in the axial direction 18 and is formed so as to be substantially flat. On its outer casing surface, it has the firtree-like toothing 74. According to the embodiment of the invention shown in FIG. 4, the firtree-like toothing is formed by three teeth 74 arranged on each side of the second portion. Preferably, the tooth size of the teeth 94 diminishes with decreasing distance from the first portion 70. As clearly evident in FIG. 4, at its free end facing away from the first portion, the second portion 72 has an inlet chamfer 96 which facilitates mounting of the actuator housing 14 on the valve means housing 12. The connecting element 40 shown in FIG. 4 is configured as one piece. Such a connecting element 40 can be produced particularly easily by means of punching-bending processes.

Claims

1. An expansion valve (10) for controlling a fluid flow, having a valve housing (12) and at least one valve member (16) which is movably arranged in the valve housing (12), and an actuator housing (14) configured to house an electric drive of the expansion valve (10), wherein the valve housing (12) is substantially formed at least partly of a metal, and wherein the actuator housing (14) is substantially formed at least partly of plastic, and wherein the actuator housing (14) is secured on the valve housing (12) by at least one connecting element (40) formed at least partly as a latching element and/or clip element.

2. The expansion valve (10) as claimed in claim 1, characterized in that the connecting element (40) has at least a first portion (70) and a second portion (72), wherein the first portion (70) at least partly engages in the valve housing (12), and wherein the second portion (72) at least in portions latches to the actuator housing (14), and wherein the second portion (72) has a firtree-like toothing (74) on an outer casing surface of the second portion.

3. The expansion valve (10) as claimed in claim 2, characterized in that the first portion (70) of the connecting element (40) is configured so as to be elastic in a circumferential direction.

4. The expansion valve (10) as claimed in claim 2, characterized in that the second portion (72) extends substantially in an axial direction (18), wherein the second portion (72) is configured so as to be substantially flat and has an inlet chamfer (96) on a free end facing away from the first portion (70).

5. The expansion valve (10) as claimed in claim 1, characterized in that the connecting element (40) engages around the valve housing (12) and the actuator housing (14) in an axial direction (18).

6. The expansion valve (10) as claimed in claim 1, characterized in that the connecting element (40) is configured so as to be substantially U-shaped and has at least two legs (58, 59), wherein the legs (58, 59) are arranged substantially parallel to one another.

7. The expansion valve (10) as claimed in claim 6, characterized in that the legs (58, 59) of the connecting element (40) each have a free end (42a, b), wherein clamping protrusions (44, 45) are arranged on each free end (42a, b) of the connecting element (40).

8. The expansion valve (10) as claimed in claim 7, characterized in that an undercut (46, 47), in which the corresponding clamping protrusion (44, 45) of the connecting element (40) engages, is arranged on the valve housing (12) and/or the actuator housing (14).

9. The expansion valve (10) as claimed in claim 1, characterized in that the connecting element (40) is configured as one piece.

10. The expansion valve (10) as claimed in claim 1, characterized in that the valve housing (12) has at least two first openings (20, 22), wherein the valve member (16) is movably arranged inside the valve housing (12), and a fluid flow through the openings (20, 22) is definable and changeable depending on the position of the valve member (16) with respect to the openings (20, 22).

11. The expansion valve (10) as claimed in claim 10, wherein the valve member (16) is configured to be moved by the electric drive.

12. The expansion valve (10) as claimed in claim 1, wherein the valve housing (12) is substantially formed at least partly of aluminum.

13. The expansion valve (10) as claimed in claim 2, characterized in that the first portion (70) of the connecting element (40) is configured so as to be elastic in a circumferential direction as an at least partly slotted sleeve.

14. The expansion valve (10) as claimed in claim 1, characterized in that the connecting element (40) engages around the valve housing (12) and the actuator housing (14) in an axial direction (18), wherein the connecting element (40) is configured as a clamping element.

15. The expansion valve (10) as claimed in claim 1, characterized in that the connecting element (40) is configured as one piece as a punched bent part.