DE3003869C2 - Suction and pressure valve arrangement - Google Patents

Description

characterized in that as an annular body (12, 13) one containing the intake duct (17) or the intake ducts (17); or more restrictive annular insert housing body (12) and an axially adjoining, each separate annular one Valve seat body (13) are arranged, which at least one of the intake duct (17) or the intake ducts (17) with the working space (8) connecting passage (13 ") and one with a radial one Distance from the central tube (14) arranged valve seat, and that the on the working space side End of the central tube (14) for producing a self-centering, contactless sealing Guiding with the interposition of a narrow annular gap (23) sleeve-like suction valve body with sliding bearings (19) interacts with the valve seat with only one sealing surface.

2. Arrangement according to claim 1, characterized in that the central tube (14) at its dem Pressure chamber (9) or the pressure line facing end has a narrow collar (14 '), which of a corresponding end-face recess of the insert housing body (12) is added.

3. Arrangement according to one of claims 1 or 2, characterized in that the valve seat body

(13) by means of radial webs (13 ') on the central tube

(14) is centered and the passages (13 ") remain free between the centering webs (13 '), which are in communication with the intake ducts (17) passing through the insert housing body (12).

4. Arrangement according to one of claims 1 to 3, characterized in that the central tube (14) is hardened.

5. Arrangement according to one of claims 1 to 4, characterized in that the valve seat body (13) is hardened.

6. Arrangement according to one of claims 1 to 5, characterized in that the intake channels (17) between the insert housing body (12) and the

Valve seat body (13) are arranged.

7. Arrangement according to one of claims 1 to 6, characterized in that the insert housing body (12) is shrunk onto the central tube (14).

8. Arrangement according to one of claims 1 to 7, characterized in that the valve seat body (13) is shrunk onto the central tube

9. Arrangement according to claims 7 and 8, characterized in that the valve seat body (13) with less oversize than the insert housing body (12) is shrunk onto the central tube (14)

10. Arrangement according to one of claims 1 to 9, characterized in that the annular gap (23) has a Has gap width between 0.005 mm and 0.02 mm

11. Arrangement according to one of claims 1 to 10, characterized in that the suction valve body (19) is connected to the valve seat body (19) for control the passage of the conveying medium has cooperating conical sealing surface

12. Arrangement according to one of claims 1 to 11, characterized in that the suction valve body (19) has a radial thickness that decreases in the direction of the pump working space (8) or the like

13. Arrangement according to one of claims 1 to 12, characterized in that the suction valve body (19) is hardened

14. Arrangement according to one of claims 1 to 13, characterized in that the pressure valve body (24) a guide extension (24 ″) projecting into the central tube (14) and centering on the inner wall of the tube (14) has sliding webs (24 ')

15. Arrangement according to one of claims 1 to 14, characterized in that the pressure chamber (9) or a corresponding pressure line facing side of the housing body (12) a Cap (11) is arranged, which surrounds the pressure valve, the valve body (24) by means of a valve spring (25) is stretched against the cap in the closing direction

16. Arrangement according to one of claims 1 to 15, characterized in that the suction valve body (19) is secured by a plate (21) attached to the end of the central tube (14), which serves as an abutment serves for a valve spring (20) which acts on the suction valve body in the closing direction

17. Arrangement according to one of claims 1 to 16, characterized in that the valve housing (7), which central tube (14), insert housing body (12) and valve seat body (13), designed as a unit that can be preassembled with suction and pressure valves which can be pushed into a bore (3) of a pump housing (1) or the like

The invention relates to a suction and pressure valve arrangement with a valve housing, which od in a pump housing. The like. Subjected to pressure changes between Working space and a pressure space or a pressure line can be used and an annular body with one inserted therein as an axial channel, the working space with the pressure space or the pressure line connecting, essentially smooth-surfaced central tube, a pressure valve, which the through

flow between the axial channel and the pressure chamber or controls the pressure line and its valve body with the pressure chamber side arranged as a valve seat or pressure line-side end of the central tube cooperates, and a suction valve, which the Flow between at least one intake duct arranged radially outside the central tube in the annular body and controls the working space and its ring-shaped, coaxially arranged to the central tube The valve body interacts with a valve seat formed on the end of the annular body on the working space side

A corresponding suction and pressure valve arrangement is known from US-PS 33 09 013 the suction valve has an annular plate-shaped valve body, which is formed with an annular body on the one-piece flat valve seat interacts This valve seat is penetrated by intake channels, which arranged at a radial distance from the axial channel in the ring body at an angle to its longitudinal axis are in such a way that the ends of the intake channels facing away from the valve seat form the outer circumferential surface of the annular body push through.

A perfect seal of the suction valve is only guaranteed if the annular plate-shaped valve body both radially inside the mouths the intake ducts as well as radially outside the same rests exactly on the flat valve seat. This can, however can no longer be reliably guaranteed even with slight contamination of the pumped medium. In addition, the ring body is slightly deformed in accordance with the pressure changes in the working space so that at least when using the suction and pressure valve arrangement in pronounced high pressure pumps there is no exact planarity of the valve seat relatively significant leaks occur. A hardening of the ring body to avoid it or reduction of deformations during pressure changes as well as a reduction in wear of the valve seat is difficult due to the complicated shape of the ring body.

Finally, the intake ducts, which are arranged several times in the ring body, can be used in the event of strong alternating loads of the ring body form the starting point of cracks.

It is therefore the object of the invention to provide a suction and pressure valve arrangement which is particularly suitable for high pressure pumps to create that avoids the risk of cracks and breakage even with strong pressure changes and at the same time enables the valve arrangement to be manufactured easily

This object is achieved in that an annular body containing the intake duct or ducts or comprehending annular insert housing body and an axially adjoining this, however separate annular valve seat body are arranged, which at least one of the intake duct or the intake channels with the working space connecting passage and a radial distance from the central pipe arranged valve seat, and that on the workspace-side end of the central tube for generating a self-centering contactless sealing guide with the interposition of a Narrow annular gap sleeve-like suction valve body with sliding bearings and only one sealing surface with the valve seat cooperates.

Due to the subdivision of the ring body in the insert housing body and Valve seat bodies are particularly effective in avoiding cross-sections at risk of cracking. In particular can in the transition area between the insert housing body and the valve seat body of the suction valve no tension occurs, as the separate parts are allowed to work against each other. Because of Due to its simple ring shape, the valve seat body can be hardened easily.

ίο Between the valve seat and valve body can be a high Tightness can be guaranteed because the Ventükörper only with a sealing surface with the radial distance arranged by the central tube valve seat cooperates so that the two parts even if necessary occurring deformations rest on one another on a closed annular area. the Sealing between the valve seat and valve body is further promoted by the fact that the valve body on the Central tube is guided exactly, opposite which it is contactless with the interposition of the narrow annular gap This Ringsps' is sealed, narrows at strong on the outer peripheral surface de: sleeve-shaped Valve body acting pressure forces, so that in addition to a contact-free self-centering of the valve body an extreme throttling effect of the annular gap can be achieved

Features of preferred embodiments of the suction and pressure valve assembly according to the invention go from the subclaims.

An embodiment according to claim 2 ensures a secure axial support of the central tube in the insert housing body, on the other hand, the narrow collar cannot cause any destructive notch stresses cause, since the central tube is only exposed to low alternating stress in this area is.

According to claim 3, the valve seat body can be particularly simple and therefore for high loads have suitable shape.

A hardening of the central tube and the valve seat body according to claims 4 and 5 leads to a honing wear resistance and reduces the risk deformation of these parts. Because of the simple shape of the parts, hardening is easy possible.

As a rule, the intake ducts are through the insert housing body led, d. H. by the part that is subject to the least alternating stress according to the invention. However it is also possible to design the intake ducts according to claim 6. The insert housing body have radial grooves on the face that form the intake ducts. If necessary, can also between the housing body and the valve seat body a .Distanzteil od. The like. Be inserted in such a way that a The suction path leading to the passages of the valve body remains free.

A design of the valve arrangement according to claims 7 or 8, preferably according to the combined features of both claims, enables in a simple manner joint processing and joint installation of the interconnected parts as well as a pressure-tight connection between these parts.
The features of claim 9 take into account the different strength requirements of the connections between the central tube and the valve seat body or the central tube and the insert housing body.
Claims 10 to 13 relate to particularly preferred

Referred embodiments of the suction valve. So is one Valve design according to claim 10 as a result of the mounting of the valve body with the interposition of a narrow annular gap with a gap width of 0.005 to 0.02 mm, particularly low-wear and low-noise, because the valve body - especially if the features of claim 12 are also present - on the one hand under the effect of high pressure differences can deform on its radial outside and inside so that a high pressure to low pressure end ι ο a narrowing sealing gap is created, which causes the valve body to self-center without contact, on the other hand, however, it is designed so tightly that only a small amount of leakage occurs even when the valve is closed passes through the throttling annular gap. The conical valve seat surface according to claim 11 is significantly less sensitive to contamination and the resulting leaks in comparison to flat surfaces.

According to claim 14, this can be the seat of the pressure valve forming central tube also serve to guide the pressure valve body, so that on the pressure side of the suction and pressure valve assembly according to the invention a simple structural design is achieved.

The claims 15 and 16 relate to simple ways, the abutment of the valve springs on To arrange valve housing.

This makes it possible to preassemble the suction and pressure valve arrangement according to claim 17 as a complete unit and, if necessary, to keep it in stock, see above that the valve assembly can be replaced quickly.

The invention is explained below with reference to a preferred exemplary embodiment shown in the drawing. It shows

1 shows an axial longitudinal section through a suction and pressure valve arrangement according to the invention,

Fig. 2 eirf section according to the section line II-II in Fig. 1 and

3 shows a sectional view according to the cutting line IH-III 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, a movement to the left representing the suction stroke and a movement to the right representing the pressure stroke

The pump housing 1 has a stepped bore 3, the part 3 'of which has a larger diameter, an annular recess 4 connected to an inlet channel 5' and an outlet extending in the radial direction. laßkanal 5 "has, which leads to a not shown Pressure line leads At its right end (in the drawing) the bore 3 is sealed by a closure piece 6 closed, which, as shown, can be flanged to the pump housing 1.

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

The valve housing 7 consists of an annular eo 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. The valve seat body is open the central tube 14 by means of radial webs 13 '(cf. F i g. 2) centered, between which passages 13 ″ remain free. The interior of the central tube 14 forms a central axial channel 15, which the pump work Space 8 connects to the pressure space 9 or a pressure line. The central tube has 14 at the right end a collar 14 ', which is received in a corresponding recess of the insert housing body 12 and that Central tube 14 holds axially immovable in the insert housing body 12.

The valve housing 7 abuts with a shoulder on the one hand against the step 8 'between the Buhrungteil 3' with a larger diameter and the bore part 3 ″ with a smaller diameter; on the other hand, the valve housing 7 is supported against the closure piece 6. For this purpose a pressure screw 10 is sealingly inserted into the closure piece 6, which against a cup-shaped, on Insert housing body 12 attached cap 11 with radial openings 1Γ presses.

The valve housing 7 is sealed off from the bore part 3 ′ by sealing rings 16 ′ and 16 ″ which are arranged in annular grooves on the valve seat 13 and the insert housing body 12 on both sides of the recess 4.

From the annular space 4 'connected to the inlet channel 5' and delimited by the recess 4 and the insert housing body 12, one or more suction channels 17 lead at an angle to the longitudinal axis of the Ventilgehäuscs 7 through the insert housing body 12 to an end-roped annular recess 18 on the insert housing body 12, which on 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 comprises the sleeve-shaped suction valve body 19 which is arranged in a sliding fit on the central tube 114 and which is pressed against the valve seat body 3 by means of a spring 20 in the closing direction of the valve a spring plate 21 which is fastened to the left end of the tube 14 by means of a, for example, split ring 22

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

On its right end face (in the drawing), the suction valve body 19 has a cloister-shaped sealing surface, which cooperates with a corresponding conical annular surface on the valve seat body 13, 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 in this way that the tube 14 serves to guide the pressure valve body 24. 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, soft with a corresponding conical annular surface on the pressure valve body 24 cooperates. 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 against its seat.

During the suction stroke of the pump piston « 2, ie with the pressure valve closed and the suction valve open, a pumped medium is drawn into the pump ar-

workroom 8 sucked in. During the subsequent pressure stroke, the suction valve closes, while the pressure valve closes opens, and the delivery medium flows from the pump working space 8 through the central axial channel 15, the interior of the cap U, its openings 11 'and the s Pressure chamber 9 in the outlet channel.

During this pressure stroke, the outer circumferential surfaces of the suction valve body 19 become strong Pressure forces are applied, so that the suction valve body 19 reduces its diameter and elastically the gap 23 narrows. Within the gap 23 there is from the pump working space 8 to the passages 13 "towards a pressure gradient, so that the pressure forces acting on the outer circumferential surfaces of the suction valve body 19 only at the left end of the suction valve body. pers 19 by corresponding counter-pressure forces acting on the inner annular surface of the suction valve body 19 be compensated, while the suction valve body 19 at its right end facing the valve seat body 13 practically the full pressure in the pump working room 8 must accommodate. This creates a gap 23 narrowing in the direction of the valve seat body 13, which leads to the self-centering of the suction valve body and the during the pressure stroke of the pump piston Operating pressure throttles.

So that the gap 23 is deformed in a certain way, the thickness of the suction valve body 19 increases in the direction of the pressure drop in the gap 23. It can be done without further achieve that the amount of leakage through the gap. ' 23 flows less than 1% of the volume displaced during the pressure stroke

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Claims (1)

Patent claims:
1. Suction and pressure valve assembly with - A valve housing which is inserted into a pump housing od. The like. Between a (strong) pressure change subject work space and a Pressure chamber or a pressure line can be used and an annular body with a therein used as an axial channel, connecting the working space with the pressure space or the pressure line, has essentially smooth-surfaced central tube, - A pressure valve, which the flow between controls the axial channel and the pressure chamber or the pressure line and its valve body with the pressure side or pressure line side arranged as a valve seat The end of the central tube cooperates, and - A suction valve, which the flow between controls and controls at least one intake duct arranged radially outside the central tube in the ring body and the working chamber its annular, coaxially arranged valve body with a central tube working space-side end of the annular body formed valve seat cooperates,