DE1675427A1 - PRESSURE LIMITER, IN PARTICULAR OVERFLOW VALVE FOR HYDRAULIC LINES UNDER HIGH PRESSURE - Google Patents

Description

Eat the J5O. December 1967 (29 936 / fr / tti)

Patent registration of the company
HOUILtERES DU BASSIN DU NORD
ET DU PAS-DE-CALAIS
20, rue des Minimes
DOUAI (North) France

Pressure limiter, especially overflow valve for hydraulic lines under high pressure.

We already know different types of pressure limiters with an outlet opening through which pressure medium flows off, as soon as its pressure exceeds a certain value. The drain is usually displaced or deformed a closure member achieved.

The training of these previously known is quite general Arrangements are quite complicated and a large number of individual parts are required for their construction. Since they are in The rest of the work with mechanical organs results in a certain inertia. Apart from that, have a

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whole series of these devices a quite fragile locking member on BEZW. an occlusive organ, which is very must be carefully inserted into the housing of the device.

The invention aims to remedy this situation and to design a device of this type in such a way that its structure is very simple and is robust, with the smallest possible number of individual parts required and even under harsh operating conditions the operational safety should be very high.

To solve this problem, the invention proposes a To design a pressure limiter, in particular an overflow valve for hydraulic lines under high pressure, in such a way that that a housing with an inlet and an outlet opening and a constricted closure member arranged therein with at least one passage connecting the two housing openings to one another, furthermore through one Part of the closure member surrounding chamber within the housing, in which a standing under a taring pressure Control medium can be fed in, so that according to the ratio of this taring pressure to that in the passage of the closure member prevailing pressure, which is equal to the pressure in the hydraulic line to be controlled, a release or a Closure of the passage can be achieved.

The closure member is preferably elastically deformable Body formed and has one passage or several parallel to the axis of symmetry of the organ Passages on. The closure member can rest with its one end on a shoulder in the housing and on be held in place by a housing cover at the other end

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or also held at both ends by a housing cover expediently screwed into the housing will. In order to be able to include the control medium in the chamber of the housing, a. Filling and closing organ provided so that the pressure limiter according to the invention works completely automatically.

In a preferred embodiment, there is the closure member from an elastically deformable block. The term "constricted" means that the cross-section of the passage or the passages of this closure organ, for example, similar to the central area of its own Cross-section is narrowed in a single passage extending in its axis of symmetry.

The area of application for the pressure limiter according to the invention is in particular an overflow valve for hydraulic rams thought.

To simplify the design, improve the operating characteristics, and most importantly, uncontrollable deformations Preventing the occlusive organ in the areas near its free surfaces is essential for supply the housing chamber with the control medium and for the inclusion of the same in this chamber with an automatic valve pierced valve body provided, the bore of which is in a channel of the briefly used for this purpose The working medium opens and is pushed back onto its seat by the elastic axial pressure of the constricted closure organ is, the bore of this valve body with at least one of the passages of the constricted closure organ flees.

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Appropriately, such a closure member is assigned a rigid reinforcing part, which at least rests against part of its free surface, however a contact of the working medium. and the control medium should be possible with this free area.

If it is an external free area, Such a reinforcement part preferably consists of at least one generally circular ring-shaped Organ. In detail, this reinforcing member can be formed by two half-shells, which are in the longitudinal direction although they are rigid, they can be spread apart when the Versohlußorganes expands.

If it is an inner surface, such a reinforcement part consists of a mandrel, which is extends over the entire length of this free inner surface.

According to a variant, such a reinforcing dome have at least one frustoconical elevation, which belongs to the outer part of the housing or a corresponding cover thereof and into a homologous end of the closure member, which has a correspondingly frustoconical recess.

The mandrel can be formed, for example, by a full needle which, on the side of the outlet of the working medium, has a deformation which is outside the passage and which offers a passage for this working medium. Such a mandrel can also consist of a cylindrical extension of a frustoconical elevation on the side of the inlet of the working medium, which on this side has an axial inlet blind bore and one of the

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has an outlet blind bore coming from the other side, these two blind bores in the central area of this dome on both sides of a full part of the same with the External surface of this dome are connected by transverse bores.

A more detailed explanation of the invention emerges from the following description of some preferred embodiments with reference to the accompanying drawings; show it:

Figure 1 is a longitudinal section through an inventive Pressure limiter in a schematic representation;

FIG. 2 shows a longitudinal section through a pressure limiter in a somewhat modified design;

Figure 3 shows a pressure limiter with a reinforcing member for the outer surface of the closure member, also in longitudinal section;

FIG. 4 shows a section through FIG. 5 along the line IV-XV; FIG. 5 shows another variant with an axial needle; and

FIG. 6 shows a further variant with a mandrel connected to the one housing cover.

The main area of application of the pressure limiter according to the invention is, for example, an overflow valve for hydraulic Stamp thought through which the breakage of mechanical parts of the same is prevented. The device consists of one Housing l with a cylindrical inner chamber 2, which of goes through top to bottom. In this chamber, a closure member 3 made of an elastically deformable material is arranged.

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This organ points in its axis of symmetry, which with the Axis of the chamber 2 coincides, a single passage on, the cross section of which can be changed by constriction of the organ 3. The working medium, its overpressure is to be prevented, therefore normally does not flow into the passage 4, while it flows through this passage, as soon as its pressure exceeds a limit value at which the constriction of the closure member 3 does not sufficient to close the passage 4.

This constriction results from the pressure of a control medium which, in the exemplary embodiment described, is formed by a gas and is located in the circular ring 5 which forms a widened part of the cylindrical chamber 2. This circular ring 5 is delimited on the outside by the housing 1 and on the inside by the closure member 3. The axial length of the ring corresponds practically to a region 4a of the passage 4 with a small cross-section. The upper and lower areas 4b of the passage 4 have a progressively increasing cross section from the cross section of the area 4a. In the same way, the cross section of the organ 3 grows from its central region 3 ^a to the two end regions 3 b, where its side surfaces are supported against the wall of the housing 1 which delimit the chamber 2.

A cover 6 with a central bore 7 running coaxially with the passage 4 is screwed into a corresponding axial bore of the housing 1 and rests on the outer end of the organ 3, the lower end of which rests only on the extension 10. The bore 7 of this cover 6 serves as an inlet opening for the working medium to be controlled and an outlet opening 8 running coaxially to the passage 4 enables this medium to flow out. For connection to one of the working

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medium-containing space or a corresponding line an internal thread 9 in the cover 6 is used.

In the embodiment described, the circular ring Space 5 via a bore 11 with a filling and closing element 12 in connection. The latter exists from a ball valve 13, one part of which is in a recess l4 of the housing 1 and its other part is screwed into the housing by means of a thread 15. A External thread on ball valve 12 enables connection to a filling device.

The sealing of the annular chamber 5 is achieved or in the simplest possible way by the closure member also by arrangements known per se or by a combination thereof. The pressure of the control medium is fixed. the Switching limit for the automatic response of the invention The device can therefore easily be changed by lowering the pressure of the control medium or lower it with the aid of the fill and seal assembly 12.

Such a pressure limiter works as follows: the working medium enters the cover 6 in 7 via the connection line, not shown, and flows from there into the passage 4, initially in its section #b.

If the pressure of the working medium is below the switching

limit lies, i.e. below the pressure of the in the circular ring-shaped Space 5 enclosed gas, the elastic member 3 constricts the section 4a of the passage 4.

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However, as soon as the pressure of the working medium rises and exceeds the switching limit set by the control medium, this pressure equalizes and exceeds the control medium, so that the passage 4 opens and reduces the overpressure of the working medium. As soon as the pressure drops again, the passage 4 closes again under the influence of the fixed pressure prevailing in the annular space 5.

This already shows that the device according to the invention is very simple, extremely reliable, one W forms a very handy block and an easily changeable, i.e. to one that corresponds to the respective operating requirements Switching value is adjustable.

It is clear that the above-described training can be deviated without further ado, the closure member in particular not necessarily needing to have a circular cross-section. The passage through this closure member can be cylindrical or have an elongated or even circular cross-section and, for example, in the latter case it can accommodate an inner mandrel. The chamber formed in the housing can also have different shapes and be closed by one or two covers W. In addition, the above-described arrangement can be used to stop the flow of a working medium if its pressure falls below a certain value.

The closure member, which again is supported in the previously described example with its end faces on a shoulder in the housing and on a lid and on the other with its side surfaces on the inner walls of the ^G ehäuses

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is present, can also deal with a in a corresponding manner support the recessed end face on an elevation, which rests on the approach of the housing or on the cover, the side surfaces of the closure member then no longer rest on the inner walls of the housing.

In the modified embodiment of the invention shown in Figure 2, the pressure limiter consists of one Housing l with a chamber 2, in the interior of which an element 3 made of a plastically deformable material is arranged, which is preferably elastic and has a passage 4, which by means of a gaseous control medium which is introduced into the chamber 2 outside the element 3 can be closed by constriction.

At one end of this element 3 there is a closure member 16 used, which consists of a semi-rigid elastic material and inserted into one end of the element 3 is and rests tightly on the corresponding paragraph of the chamber 2, while a short guide approach in the outlet channel 8 protrudes.

The chamber 2 is filled with gas via the corresponding opening 8 of the housing 1, in order to prevent this from flowing out To prevent gas through the central bore 4, a removable plug 17 is temporarily inserted there, which is removable and protrudes with a centering in the locking bore l6 and carries a handle end, which in the Bore 8 protrudes. This plug 17 can slide in the outlet channel 8.

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The working medium is used to operate this pressure limiter introduced through the inlet bore 7, through the connection 9, while the outlet bore 8 to a container is connected to take up the working medium.

In addition to this simplification of the embodiment described with reference to FIG omitted for the chamber 2, further improvements and modifications can be made to the passage features and even to 'control the functioning of the locking device.

For example, to avoid any bending of the element 3 in To prevent the chamber 2 of the housing 1, as shown in Figures 3 and 4, the middle part 3a this element is reinforced by a rigid metal organ 13, which consists, for example, of two half-shells, which are applied from both sides to this middle part 3a. The particular advantage of such an arrangement is that the deformable element 3 is flawless is held and the flow of the working medium to be controlled in its pressure both via the connection 9 and via the opposite terminal 19 can be done.

A To take this improvement even further by adding the Cross-section of the passage for the working medium to be controlled in the deformable element 3 is of considerable length is expanded, according to the invention, as shown in Figure 5, in the housing 1, a hollow plug 20 on the Screwed in the side of the connection 19, which carries a mandrel 21. This mandrel 21, which has the shape of a full needle possesses, protrudes with ample play in the opening of the body 1 adjoining the opening 19, the lower part

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this needle is in communication with the hollow part of the stopper 20 via radial bores 22. The working medium to be controlled is admitted through the bore 7 of the housing cover 6 and, when the pressure of this working medium reaches the value at which the inner passage 4 of the element just remains open, an annular shape is created between the inner wall of this passage 4 and the needle 21 Space, the passage cross-section of which is very important for a slight deviation of the central area J>& of the element 3. After passing through this circular passage, the working medium flows through the radial bores 22 into the interior of the hollow plug 20 and from there into a suitable e'-older or a suitable line.

In the embodiment shown in Figure 6, a cover 23 is screwed from the inlet side of the chamber 2 into the housing 1 of the pressure limiter, which has a mandrel 23a in the middle, which merges into the lower part of this housing cover via a frustoconical elevation 23b. The mandrel 23a. and the elevation 23b are introduced into the passage 4 of the deformable element 3, the elevation engaging a corresponding frustoconical recess on the inlet side of this passage. From the connection 9 and the adjoining inlet channel 7, a blind hole 24 runs through the frustoconical elevation 23b and the mandrel 23a, which is separated by a short separator 25 from a second hole 2.6 which opens to the other end of this dome 23. These two blind bores are with the outside of this dome by radial bores 27 respectively. 28 in connection.

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In this training, the adjustable Elejaent5 is counteracted under the action of the control medium in the annular space 5 pressed the mandrel 23 and closes in this way the radial bores 27 and 28.

As soon as the pressure of the working medium is the intended If the set pressure is exceeded, this overpressure at the mouth of the bores 27 pushes the central area 5a of the element 5 apart so that the inner surface of the passage 4 from Mandrel 25a is lifted off and, as a result, the working medium can flow to the inlet of the bores 28 and from there via the blind bores 26.

It goes without saying that the various possibilities for improvement can be found in a pressure limiter of the type under discussion here combine with each other, especially those to simplify the introduction of the control medium with those of the rigid guide elements for the closure member or even both. On every pail, and especially when If the control medium is a gas, it is desirable to determine the value of the ratio between the volume of the chamber, which this control medium contains and the content of the passage through the closure organ the special operating conditions adapt.

Furthermore, the closure member should be as "small as possible." Dimensions are given taking into account the operating conditions and at the same time the largest possible contact area with the housing and its approaches, in order to achieve the best possible heat dissipation for the heat that passes through the friction of the working medium occurs on the inner surface of the passage through the closure member.

Expectations:

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Claims (1)

1. Pressure limiter, especially overflow valve for hydraulic lines under high pressure, characterized by a housing (l) with an inlet (9, 7) and an outlet opening (8) and a constricted closure member (3) arranged therein at least one of the two housing openings with one another connecting passage (4), further through a part of the closure member surrounding chamber (5) within the Housing into which a control medium under a taring pressure can be fed, so that according to the Ratio of this taring pressure to the pressure prevailing in the passage of the closure member, which is equal to the Pressure in the hydraulic line to be controlled, a release or a closure of the passage can be achieved is. 2. Pressure limiter according to claim 1, characterized in that the closure member (3) is formed as ^an elastically deformable body and its passage (4) or its passages run parallel to its axis of symmetry. 3. Pressure limiter according to claim 1 or 2, characterized in that that the closure member (3) with its one end rests on a shoulder (10) in the housing (l) and on the other End is held by a housing cover (6). 4. Pressure limiter according to claim 1 or 2, characterized in that the closure member (3) through at both ends a housing cover (6) is held in the housing (l). 209881/0068 / τ 5. Pressure limiter according to claim 3 or 4, characterized characterized in that at least one end of the closure member (3) is on an increase in the approach (10) of the housing (l) or the housing cover (6). 6. Pressure limiter according to one of claims 1-5 *, characterized in that the closure member (3) itself laterally on the inner walls (2) of the housing (l). 7 pressure limiter according to one of claims 1-6, characterized in that at least one passage (4) of the closure member (3) is a having constant rectilinear cross-section in the direction of its length. 8. Device according to one of claims 1-6, characterized in that at least one passage (4) of the Locking organs (3) have a variable cross-section (4b, 4c, 4b) in the direction of its length when at rest having. 9. Pressure limiter according to one of claims 1-8, characterized in that a closure and filling member (12) encloses the control medium with a certain variable taring pressure. ^{λ v} 10. Pressure limiter according to claim 8, characterized? shows that the closure organ (3) and its passage (4) or its passages in the central area (3a and 4a) have a narrowed cross section and this corresponds essentially to the axial length of the pressure chamber (5). 2098817 0068 1675-27 11. Pressure limiter according to one or more of the claims 1-10, characterized in that to fill the pressure chamber (5) with the control medium and to hold it back in the chamber an automatic valve (l6) with itself in a briefly used for this purpose Channel of the working medium opening perforated valve body is provided and this valve body through the elastic axial pressure of the constricted closure member (3), on which it is supported, on its seat (10) is pushed back, the bore of this valve body with at least one of the channels (4) of this closure member flees. 12. Pressure limiter according to one or more of claims 1-11, characterized in that the constricted Closure element (3) is assigned to at least one rigid reinforcement element (18 or 21 or 23) and the latter rests against at least part of a free surface of the closure member without access to this part of the surface for the appropriate medium to hinder. 15. Pressure limiter according to claim 12, characterized in that that the rigid reinforcing member (l8) for a free outer surface of the closure member (3) by at least an annular body is formed. 14. Pressure limiter according to claim 13, characterized in that that the reinforcing member consists of two half-shells (18, 18). 15. Pressure limiter according to claim 12, characterized in that the rigid reinforcing part (21 and 23 respectively) for a free inner surface of the closure member (3) '2 09881/0068 a mandrel is formed which extends at least over the entire length of this free inner surface. l6. Pressure limiter according to claim 15, characterized in that that the inner reinforcement part (23) has at least one frustoconical elevation (23b), which belongs to an outer part of the housing (1) or a corresponding cover (6) thereof and penetrates into a homologous end of the passage (4) of the closure member (3), which for this purpose a has corresponding frustoconical recess. 17- pressure limiter according to claim 15, characterized in that that the mandrel is designed as a full needle (21) which is on the side of the outlet of the working medium has a deformation lying outside the passage (4) and a channel for this medium forms. ; 18. Pressure limiter according to claim 15, characterized in that the mandrel (23) on the side of the inlet opening (9) of the hydraulic line to be controlled has a frustoconical elevation (23b) and this a cylindrical extension (23a) with a blind hole (24) opening from the inlet side and outlets (27) emerging laterally at the end and a second one from the outlet side of the hydraulic line Bears a blind bore (26) with transverse channels (28) also arranged at the end. Patent attorney Dr. W. Andreevsky. 209881/0068 Blank page