DE3003869A1 - High-pressure pump valve assembly - has insert contg. radial inlet and central tube with inlet valve at one, and outlet valve at other end - Google Patents

Abstract

The valve assembly is particularly intended for a high-pressure pump. The valve housing assembly contains a central axial passage between the pump chamber and an outlet chamber and inlet ducts extending in the radial direction. Outlet and inlet valves connect the passage to the outlet chamber and the ducts to the pump chamber respectively. The assembly, which may form a pre-assembled unit, comprises an annular insert which contains the ducts and a central tube forming the passage. The outlet end of this tube may have an annular collar located in a corresponding recess in the insert. The tube and the valve seat ring may be hardened.

Description

"Suction and pressure valve arrangement"

The invention relates to a suction and discharge valve assembly, in particular for high pressure pumps, with -einem in-a-pump housing (or a housing for under similarly working conveying devices) usable valve housing, which is penetrated by a central axial channel, in particular by a The working chamber of the pump (or the like), which is subject to strong pressure changes, becomes a pressure chamber or a pressure line, and one or. several - leading to the work area, Has intake channels arranged radially outside the axial channel, - a pressure valve which the flow between the axial channel and the pressure chamber or a pressure line controls and --a suction valve, which controls the flow between the

controls the intake ducts and the working chamber and an annular, Has suction valve body arranged coaxially to the axial channel.

D.erart-ige-suction and -pressure valve arrangements are for example from known from DE-A5 1 728-245. Suction and pressure valves have a common central axis, being the suction valve in a ring around one of the pump working space to the Pressure valve leading central channel is arranged around. Valve arrangements of this Art require little space and enable a compact design of the valve housing, which is particularly important at higher pressures.

On the other hand, the valve housing is very strong at extremely high pressures Subject to alternating stresses as a result of the multiple perforations of the valve housing for the pressure channel and the intake channels lead to strength problems can lead, which are mainly due to notch effects and the risk of cracking, especially if the sealing parts need to be hardened.

It is therefore the object of the invention to provide a suction and pressure valve arrangement to create that avoids the risk of cracks and breakage even with strong pressure changes and at the same time enables simple manufacture of the valve arrangement.

This object is achieved in that in one of the Initially mentioned type corresponding suction and pressure valve arrangement, the valve housing an annular insert housing body containing or defining the intake passages has, in which a separate, essentially smooth-surfaced central tube is used is, which forms the central axial channel.

According to the invention, the valve housing consists of several parts, which can be optimally designed according to their respective function, whereby the central tube forming the central axial channel, which alternates stresses is particularly exposed to accommodate the to be used in the pump housing Valve insert housing body is smooth-surfaced and particularly simple Notches, which can be the starting point of stress cracks, have an effect as a result the division into central tube and insert housing body only to a limited extent.

Features of preferred embodiments of the suction according to the invention and pressure valve arrangement are based on the further claims and the description emerged.

An execution according to claim 2 ensures a safe axial support of the central tube in the insert housing body, on the other hand, can the narrow collar does not cause any destructive notch stresses, as the central tube is only exposed to low alternating stress in this area.

Claims 5 and 4 relate to a particularly advantageous embodiment of the invention, in which the valve seat body of the suction valve and the suction channels containing EJ.r; -set housing bodies designed as separate components are. The tube, insert housing body and suction valve seat are therefore separate, a three-part Insert unit forming parts that are easy to implement. Let through the subdivision Above all, cross-sections at risk of cracking can be avoided particularly effectively. In particular can in the transition area between the insert housing body and the valve seat body of the suction valve no stresses occur because the parts are separated from each other can work against each other. The parts forming the valve housing, i.e. Central tube, insert housing body and valve seat body largely independent be formed from each other according to their respective function and load.

According to claim 5, the valve seat body can be a particularly simple one and thus have a shape suitable for high loads.

A hardening of the central tube and the valve seat body according to the Claims 6 and 7 lead to a high level of wear resistance and reduce it Risk of deformation of these parts. Because of the simple shape of the parts, the Hardening possible without difficulties.

As a rule, the intake channels are body through the insert housing guided, i.e. through the part subject to the least alternating stress according to the invention. However it is also possible to use the intake duct according to the claim 8 train. For this purpose, the insert housing body can have radial grooves on the face, which form the intake ducts. If necessary, it can also be between the housing body and the valve seat body a spacer or the like. be inserted such that a Suction path rrei leading to the passages of the valve body remains.

An embodiment of the valve arrangement according to claims 9 or 10, preferably according to the combined features of both claims, enables joint processing and joint processing in a simple manner Installation of the interconnected parts as well as a pressure-tight connection between these parts.

The features of claim 11 contribute to the different strength requirements the connections between central tube and valve seat body or central tube and Insert housing body invoice.

Claims 15 to 17 relate to particularly preferred embodiments of the suction valve. So is a valve training according to claim 12 due to the storage of the valve body with the interposition of a narrow annular gap, preferably with a saving width of 0.005 to 0.02 mm, particularly low-noise, because the valve body is on the one hand under the effect of high pressure differences its radial outside and inside can deform so that a from the high pressure end to the low pressure end narrowing sealing gap arises, which is a causes contactless self-centering of the valve body, on the other hand, however can be made so tight that even with the valve closed only a small amount Leakage through the. throttling annular gap passes. Such a valve training also has the advantage that, in contrast to ring valves with two to each other concentric valve seat surfaces, only a single annular valve seat surface is required is and this can thus be designed without difficulty in such a way that under the effect of deformations resulting in uncontrollable leaks in the controlling valve seat surface can be avoided. In particular, a conical steering Valve seat surfaces are provided which, compared to flat surfaces, protect against contamination and the resulting leaks are much less sensitive.

According to claims 17 and 18, the central tube can also be used as a seat and / or serve to guide the valve body of the pressure valve, so that also on the pressure side the suction and pressure valve assembly according to the invention a simple constructive Design is achieved.

Claims 19 and 20 relate to simple ways to arrange the abutments of the valve springs on the valve housing.

This makes it possible to use the suction and pressure valve assembly as a complete To pre-assemble the unit (claim 21) and, if necessary, to keep it in stock, so that the valve assembly can be replaced quickly.

The invention is illustrated below with the aid of one in the drawing preferred embodiment explained.

1 shows an axial longitudinal section through an inventive Suction and pressure valve arrangement, FIG. 2 is a sectional view corresponding to the cutting line II-II in FIG. 1 and FIG. 7 a sectional view corresponding to the section line 111-111 in Fig. 1.

In Fig. 1, 1 denotes the pump housing and 2 denotes the pump piston. This moves back and forth in the direction of the double arrow x, with one Movement to the left represents the suction stroke and a movement to the right represents the pressure stroke.

The pump housing 1 has a stepped bore 9, part of which 3 'with a larger diameter an annular, connected to an inlet channel 5' Depression ii and an outlet channel 5 ″ extending in the radial direction which leads to a pressure line, not shown. At her (in the Drawing) the right end of the bore 3 is tightly closed by a closure piece 6, which, can be flanged to the pump housing 1 as shown.

A valve housing 7 is inserted into the bore 3 of the pump housing 1, with the pump working chamber 8 on the left of the valve housing 7 and the valve housing on the right 7 the pressure chamber 9 remains.

The valve housing 7 consists of an annular insert housing body 12, an annular valve seat body 13 and a central tube 14 on which the Insert housing body 12 and the valve seat body 13 are shrunk on. It is the valve seat body on the central tube 14 by means of radial webs 13 '(see. Fig. 2) centered, between which passages 1 remain free. The interior of the central tube 14 forms a central axial channel 15 which connects the pump working chamber 8 with the pressure chamber 9 or a pressure line connects. The central tube has 14 at the right end a collar 14 ', which is in a corresponding recess of the insert housing body 12 is received and the central tube 14 is axially immovable in the insert housing body 12 holds.

The valve housing 7 abuts with a shoulder on the one hand against the Step 8 'between the bore part 3' with a larger diameter and the bore part 3 "with smaller diameter; on the other hand -is the valve housing 7 supported against the closure piece 6. For this purpose, a pressure screw is in the closure piece 6 10 used sealingly, which against a cup-shaped, on the insert housing body 12 attached cap 11 with radial openings 11 'presses.

Opposite the bore part 3 ', the valve housing 7 is provided with sealing rings 16 'and 16 "sealed in annular grooves on the valve seat 13 and the insert housing body 12 are arranged on both sides of the recess 4.

From the annular space 4 'connected to the inlet channel 5', that of the recess 4 and the insert housing body 12 is limited, lead one or more suction channels 17 at an angle to the longitudinal axis of the valve housing 7 through the insert housing body 12 to an end-face annular recess 18 on the insert housing body 12, the one hand from the outer surface of the central tube 14 and on the other hand from a conical annular surface on the insert housing body 12 is limited.

The recess 18 connects the intake channels 17 with the passages 13 between the centering webs 13 ′ of the valve seat body 13.

The passages 13 "are controlled by the suction valve, which the sleeve-shaped on the central tube 14 in a sliding fit arranged Suction valve body 19 comprises which by means of a spring 20 in the closing sense of the Valve is pressed against the valve seat body 13. As an abutment for the spring 20 is a spring plate 21, which by means of a split ring 22, for example the left end of the tube 14 is attached.

The suction valve body 19 is on the outside of the central tube 14 guided with the interposition of a narrow gap 23 between the central tube 14 and suction valve body 19 a sufficient contactless seal in the entrance explained sense produces, as will also be explained further below.

The suction valve body has on its right end face (in the drawing) 19 a conical sealing surface with a correspondingly conical annular surface cooperates on the valve seat body 15, so that a cone-like valve seat results.

At the right end of the central axial channel 15 is the pressure valve, the valve body 24 of which has an extension 24 "provided with centering webs 24 ', which protrudes into the axial channel 15, such that the tube 14 for guidance of the pressure valve body 24 is used. The valve seat for the pressure valve body 24 is formed by a conical annular surface 24 '' 'at the right end of the central tube 14, Which cooperates with a corresponding conical annular surface on the pressure valve body 24. A valve spring 25 is supported against the cap 11 forming the abutment and presses the pressure valve body 24 in the closing direction of the pressure valve its seat.

During the suction stroke of the pump piston 2, i.e. when the pressure valve is closed and open suction valve, a pumped medium is conveyed through the suction channels 17, the Indentation 18 and the passages 13 ″ sucked into the pump working space 8 the following pressure stroke closes the suction valve while the pressure valve opens, and the delivery medium flows from the pump working space 8 through the central axial channel 15, the interior of the cap 11, its openings 11 'and the pressure chamber 9 in the outlet channel.

During this pressure stroke, the outer circumferential surfaces of the suction valve body 19 acted upon by strong compressive forces, so that the suction valve body l9. his The diameter is elastically reduced and the gap 25 is narrowed. Inside the gap 23 there is a pressure gradient from the pump working space 8 to the passages l) ", so that the act on the outer peripheral surfaces of the suction valve body 19 Pressure forces only at the left end of the suction valve body 19 by appropriate, on the inner annular surface of the suction valve body 19 compensates for acting counterpressure forces will while the suction valve body 19 on its right, the valve seat body 13 facing the end practically absorb the full pressure in the pump working space 8 got to. This creates a gap that narrows in the direction of the valve seat body 13 23, which leads to the self-centering of the suction valve body and during the pressure stroke of the pump piston throttles the operating pressure.

So that the gap 25 is deformed in a certain way, the thickness increases of the suction valve body 19 in the direction of the pressure drop in the gap 23. It can be easily achieve that the amount of leakage flowing through the gap 23 is less than 1% of the volume displaced during the pressure stroke.

Claims (1)

Claims suction and pressure valve arrangement, especially for high pressure pumps, With a valve housing which can be inserted into a pump housing (or the like), which of a central axial channel is penetrated by a particularly strong pressure change subject working space of the pump (or the like.) To a pressure space or a pressure line leads, and one or more leading to the working space, radially outside half of the axial channel arranged intake ducts, - a pressure valve, which the flow between controls the axial channel and the pressure chamber or a pressure line and - a suction valve, which controls the flow between the intake duct or ducts and the working space and an annular, coaxially arranged to the axial channel Has suction valve body, as a result of which the valve housing (7) an annular insert housing body containing or delimiting the intake ducts (17) (12), in which a separate, essentially smooth-surfaced central tube (14) is used, which forms the central axial channel (15). 2. Arrangement according to claim 1, characterized in that the central tube (14) has a narrow end at its end facing the pressure chamber (9) or the pressure line Has collar (14 '), which has a corresponding front recess of the insert housing body (12) is included. 5. Arrangement according to claim 1 or 2, characterized in that the valve housing (7) essentially consists of the central tube (14), one on the central tube pushed-on insert housing body containing or delimiting the suction channels (17) (12) and a valve seat body axially adjoining this but separate from it (13) exists. 4. Arrangement according to claim 3, characterized in that the central tube (14) a to the work space (8) via the Insert housing body (12) also axially led out .End has, on which an annular valve seat body (13) is placed, which has passages (13 ") - which the intake channels (17) Connect to the pump working space (8). 5. Arrangement according to Anspru-ch 4, characterized in that the valve seat body (13) is centered on the central tube (14) by means of radial webs (13 ') and between the centering webs (13 ') leave the passages (13 ") free that connect to the insert housing body (12) penetrating intake channels (17) -are in connection. 6. Arrangement according to one of claims 1 to 5, characterized in that that the central tube (14) is hardened. 7. Arrangement according to one of claims 3 to 6, characterized in that that the valve seat body (13) is hardened. 8. Arrangement according to one of claims 2 to 7, characterized in that that de suction channels (17) between the insert housing body (12) and the valve seat body (13) arranged -are .. 9. Arrangement according to one of claims 1 to 8, characterized in that that the insert housing body (12) is shrunk onto the central tube (14). 10. Arrangement according to one of claims 3 to 9, characterized in that that the valve seat body (13) is shrunk onto the central tube. 11. Arrangement according to claims 9 and 10, characterized in that that the valve seat body (1D) is less oversized than the insert housing body (12) is shrunk onto the central tube (14). 12. Arrangement according to one of claims 1 to 10, characterized in that that the suction valve body (19) on a protruding into the pump working space (8) The end of the central tube (14) is slidably guided. 13. Arrangement according to one of claims 1 to 12, characterized in that that the suction valve body (19) on the central tube (14) to generate a self-centering Contactless sealing guide with the interposition of a narrow annular gap (23), preferably with a gap between 0.005 mm and 0.02 mm, stored is. 14. Arrangement according to claim 15, characterized in that the suction valve body (19) one with the valve seat body (19) for controlling the passage of a conveyed medium having cooperating conical sealing surface. 15. Arrangement according to one of claims 15 or 14, characterized in that that the suction valve body (19) in the direction of the pump working space (8) or the like. having decreasing radial thickness. 16. Arrangement according to one of claims 1 to 15, characterized in that that the suction valve body (19) is hardened. 17. Arrangement according to one of claims 1 to 16, characterized in that that the central tube (14) at its the pressure chamber (9) or a corresponding pressure line facing end at the same time the - preferably conical valve seat (24 "') for the Forms pressure valve body (24). 18. Arrangement according to claim 17, characterized in that the pressure valve body (24) a guide extension (2-4 ") protruding into the central tube with centering, on the inner wall of the tube (14) has sliding webs (24 '). 19. Arrangement according to one of claims 1 to 18, characterized in that that facing the pressure chamber (9) or a corresponding pressure line Side of the housing body (12) a cap (11) is attached, which the pressure valve encloses whose valve body (24) by means of a valve spring (25) against the cap is stretched in the closing direction. 20. Arrangement according to one of claims 1 to 19, characterized in that that the suction valve body (19) attached by one at the end of the central tube (14) Plate (21) is secured, which acts as an abutment for the suction valve body valve spring (20) acting in the closing direction is used. 21. Arrangement according to one of claims 1 to 20, characterized in that that the valve housing (7), which central tube (14), insert housing body (12) and Valve seat body (15) comprised as a preassembled with suction and pressure valve Unit is formed, which in a bore (3) of a pump housing (1) (or the like.) is retractable.