GB1573278A

GB1573278A - Electromagnetically-operated valve

Info

Publication number: GB1573278A
Application number: GB1842577A
Authority: GB
Original assignee: Danfoss AS
Current assignee: Danfoss AS
Priority date: 1976-05-05
Filing date: 1977-05-03
Publication date: 1980-08-20
Also published as: NL7704873A; CH617253A5; DE2619772B2; DK190177A; DE2619772A1; DE2619772C3

Abstract

The solenoid valve, which is designed as a three-way valve, contains a solenoid plunger (10) which interacts with a coil (5) and has continuous longitudinal grooves (19, 21) on the circumference, of which two, diametrically opposite longitudinal grooves (19), serve to accommodate return springs (20) which are supported at the bottom by a supporting ring (14). Two further, diametrically opposite longitudinal grooves (21) serve as flow channels. Since it is possible to form these longitudinal grooves (19, 21) integrally during the production of the solenoid plunger, there is no need for subsequent machining and, as a result, manufacture is simpler and cheaper. <IMAGE>

Description

(54) AN ELECTROMAGNETICALLY-OPERATED VALVE (71) We, DANFOSS A/S., a Danish company, of DK-6430 Nordborg, Denmark, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to an electromagnetically-operated valve.

The present invention provides an electromagnetically-operated valve comprising an axially movable plunger armature which has a valve closure member at at least one end, and means for guiding the armature; wherein the armature is provided with two axially extending grooves in its outer periphery, each groove housing a spring which extends between a magnetic member for effecting movement of the armature and arranged at one end of the armature and a support arranged on the other end of the armature.

In such a valve the grooves can be formed during manufacture of the plunger armature. A subsequent machining operation is, therefore, not necessary. There are several possible ways of applying the support to the armature, for example by beading or spot welding, not involving machining of the armature which can be difficult, if as is usual it is made of chromium steel.

Since the grooves extend over the entire length of the plunger armature and because they are open to the outside they can have a larger crosssection than if holes are machined in the armature for receiving the springs as in a known construction. Adequate space is therefore available for the springs so that the latter can have a lower specific loading and tolerance differences are less noticeable. Depending on the selected method of manufacture, the surface quality of the longitudinal grooves can be considerably better than with a machining operation. Consequently, less friction will also result in a longer life for the return springs.

In the case of a three-way valve, the plunger armature preferably has four axially extending grooves, two of the grooves being opposed and receiving the said springs, and the other grooves serving as fluid flow passages of the valve. Two of the grooves will then serve different purposes from the other two grooves but all of them can be formed in the same way during manufacture of the plunger armature.

If the support is provided on a common supporting ring, further simplification is obtained in that only one securing operation is required.

In particular, the supporting ring may have radially outwardly extending arms, each of which arms provides a respective one of the said supports, the ring being held in position on the armature by tumed-over portions of the end of the plunger armature, which portions lie between the arms.

Preferably, the closure member is disposed in a recess in an end of the armature and the supporting ring overlaps the rim of the recess to hold the closure member in position. The supporting ring therefore has the additional function of retaining the closure member.

Further, it is recommended that each spring is coiled tightly at both its ends, and each end of the spring is ground flat. The springs are securely held in the grooves by the guide means (which is preferably a tube). The end of each spring projecting from its respective groove is so stiff that the gap between the plunger armature and the magnetic member (which is preferably a plug closing one end of the guide tube) remains constant when the coil is not energised.

Since the other end of the spring is of the same construction it can be mounted in its respective groove by inserting either end into that groove.

Further, each support may be shaped to provide proper location of its respective spring.

This facilitates location of the spring in its groove.

Numerous known methods are suitable for the manufacture of the armature. In particular, the armature may be a cast or moulded member, the grooves being formed during casting or moulding. This permits various other projections and recesses to be formed at the same time as the grooves. However, the plunger armature may also be formed by a drawing and/or pressing process. This will result in a particularly good surface quality. Further, the plunger armature may be sintered from metallic powder.

An electromagnetically operable valve constructed in accordance with the present invention will now be described, by way of example only, with reference to the accompanying drawing, wherein: Figure 1 is a part-sectional side elevation of the valve; Figure 2 is a plan view of the plunger armature of the valve; and Figure 3 is a part-sectional side elevation of the plunger armature taken from the right-hand side in Figure 1.

Referring to the accompanying drawing, the valve comprises a valve housing 1 with an inlet connection 3 and a first outlet connection 2.

A plastics housing 4 comprises a portion 5 housing an electromagnetic coil unit (not shown).

Arranged in the central bore of the coil is a guide element 6 (of non-magnetic material) in the form of a guide tube which is closed at one end by a magnetic plug 7. The latter is provided with a passage 8 leading to a second outlet connection 9. A plunger armature 10 is arranged in and guided for reciprocal movement within the guide element 6. At its lower end the armature 10 carried a valve closure member 11 which co-operates with a valve seat 12 connected to the inlet connection 3. This closure member 11 is disposed in a recess or depression 13 of the plunger armature 10 and is retained by a supporting ring 14, the inner peripheral edge portion of which overlaps the rim of the depression.A closure member 16 is arranged in a depression or recession or recess 15 at the upper end of the armature 10 and coperates with a valve seat 17 connected to the second outlet connection 9. The closure member is retained by a flanged edge portion or lip 18.

The plunger armature 10 has in its periphery four longitudinal grooves extending between its ends; two diametrically opposed longitudinal grooves 19 for receiving return springs 20 in the form of helical compression springs and two diametrically opposed longitudinal grooves 21 serving as flow passages. Support means 22 are provided at the lower end of each of the longitudinal grooves 19, the support means being constituted by two radially outwardly extending arms of the supporting ring 14.

The end portions 25 and 26 of each return spring 10 is tightly coiled so that there is no gap between adjacent coil turns; the end of the spring is then ground flat. The portion 25 of the spring 20 projecting from the top of the plunger armature 10 is therefore stiff. In this respect it is immaterial whether the end 25 or 26 is uppermost when the spring is installed.

WHAT WE CLAIM IS:- 1. An electromagnetically-operated valve comprising an axially movable plunger armature which has a valve closure member at at least one end, and means for guiding the armature; wherein the armature is provided with two axially extending grooves in its outer periphery, each groove housing a spring which extends between a magnetic member for effecting movement of the armature and arranged at one end of the armature and a support arranged on the other end of the armature.

2. A valve as claimed in claim 1, in which the plunger armature has four axially extending grooves, two of the grooves being opposed and receiving the said springs, and the other grooves serving as fluid flow passages of the valve.

3. A valve as claimed in claim 1 or claim 2, in which each support is provided on a common supporting ring.

4. A valve as claimed in claim 3, in which the supporting ring has radially outwardly extending arms, each of which arms provide a respective one of the said supports, the ring being held in position on the armature by turned-over portions of the end of the plunger armature, which portions lie between the arms.

5. A valve as claimed in claim 3 or claim 4, in which the closure member is disposed in a recess in an end of the armature and the supporting ring overlaps the rim of the recess to hold the closure member in position.

6. A valve as claimed in any one of claims 1 to 5, in which each spring is coiled tightly at both its ends, and each end of the spring is ground flat.

7. A valve as claimed in any one of claims 1 to 6, in which each support is shaped to provide proper location of its respective spring.

8. A valve as claimed in any one of claims 1 to 7, in which the armature is a cast or moulded member, the grooves being formed during casting or moulding.

9. A valve as claimed.in any one of claims 1 to 7, in which the armature has been formed by a drawing and/or pressing process.

10. A valve as claimed in any one of claims 1 to 7, in which the armature has been sintered from metallic powder.

11. A valve as claimed in any one of claims 1 to 10, in which the guide means is in the form ofatube.

12. A valve as claimed in claim 11, in which the magnetic member is in the form of a plug closing one end of the tube.

13. An electromagnetically-operated valve substantially as hereinbefore described, with reference to and as illustrated by the accompanying drawing.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. and recesses to be formed at the same time as the grooves. However, the plunger armature may also be formed by a drawing and/or pressing process. This will result in a particularly good surface quality. Further, the plunger armature may be sintered from metallic powder. An electromagnetically operable valve constructed in accordance with the present invention will now be described, by way of example only, with reference to the accompanying drawing, wherein: Figure 1 is a part-sectional side elevation of the valve; Figure 2 is a plan view of the plunger armature of the valve; and Figure 3 is a part-sectional side elevation of the plunger armature taken from the right-hand side in Figure 1. Referring to the accompanying drawing, the valve comprises a valve housing 1 with an inlet connection 3 and a first outlet connection 2. A plastics housing 4 comprises a portion 5 housing an electromagnetic coil unit (not shown). Arranged in the central bore of the coil is a guide element 6 (of non-magnetic material) in the form of a guide tube which is closed at one end by a magnetic plug 7. The latter is provided with a passage 8 leading to a second outlet connection 9. A plunger armature 10 is arranged in and guided for reciprocal movement within the guide element 6. At its lower end the armature 10 carried a valve closure member 11 which co-operates with a valve seat 12 connected to the inlet connection 3. This closure member 11 is disposed in a recess or depression 13 of the plunger armature 10 and is retained by a supporting ring 14, the inner peripheral edge portion of which overlaps the rim of the depression.A closure member 16 is arranged in a depression or recession or recess 15 at the upper end of the armature 10 and coperates with a valve seat 17 connected to the second outlet connection 9. The closure member is retained by a flanged edge portion or lip 18. The plunger armature 10 has in its periphery four longitudinal grooves extending between its ends; two diametrically opposed longitudinal grooves 19 for receiving return springs 20 in the form of helical compression springs and two diametrically opposed longitudinal grooves 21 serving as flow passages. Support means 22 are provided at the lower end of each of the longitudinal grooves 19, the support means being constituted by two radially outwardly extending arms of the supporting ring 14. The end portions 25 and 26 of each return spring 10 is tightly coiled so that there is no gap between adjacent coil turns; the end of the spring is then ground flat. The portion 25 of the spring 20 projecting from the top of the plunger armature 10 is therefore stiff. In this respect it is immaterial whether the end 25 or 26 is uppermost when the spring is installed. WHAT WE CLAIM IS:-

1. An electromagnetically-operated valve comprising an axially movable plunger armature which has a valve closure member at at least one end, and means for guiding the armature; wherein the armature is provided with two axially extending grooves in its outer periphery, each groove housing a spring which extends between a magnetic member for effecting movement of the armature and arranged at one end of the armature and a support arranged on the other end of the armature.