DE102007020300A1 - Piston pump for a high-pressure cleaner - Google Patents

Abstract

The invention relates to a piston pump for a high-pressure cleaner, with at least one pump chamber, in which a reciprocable piston dips and connected via a suction valve with a suction line for sucking liquid and a pressure valve with a pressure line for discharging pressurized liquid is, wherein the at least one piston is slidably supported on a piston guide. In order to further develop the piston pump in such a way that the risk of jamming of a piston is reduced, it is proposed according to the invention that the piston pump has a piston chamber for each piston, in which a piston guide is arranged with two guide surfaces aligned in alignment with one another, against which the respective piston slidably rests ,

Description

The The invention relates to a piston pump for a high-pressure cleaner with at least one pump room, in which a back and forth movable Plunger plunges and the via a suction valve with a suction line for sucking in liquid and via a pressure valve with a pressure line for dispensing pressurized fluid is connected, wherein the at least one piston on a piston guide is held displaceable.

Such piston pumps are from the DE 198 01 146 C1 known. With their help, a liquid, preferably water, sucked, placed under pressure and then discharged. An accessory device can be connected to the pressure line, for example a high-pressure hose which carries at its free end a dispensing device, in particular a spray lance or spray nozzle.

to Guide the piston is usually a piston guide used, which is designed as a separate component and between the piston pump and a pump drive is positioned. The piston pump usually has a plurality of pistons, preferably three Pistons, each immersed in a pumping chamber and together are held displaceably on the separate piston guide. The Piston guide must be aligned exactly with the pumping chambers to prevent the pistons from tilting. The production The pumping chambers and the piston guide must have very low manufacturing tolerances done and the assembly of the piston guide on the piston pump must be done very carefully and by experienced personnel. Even with proper installation of the piston guide At the piston pump there is still the danger that during the current operation of the piston pump a piston jammed due to different thermal expansion of the piston guide and the area of the piston pump surrounding the respective pumping chamber.

task The present invention is a piston pump of the above so-called type such that the risk of jamming of a piston is reduced.

These Task is in a piston pump of the generic Art solved according to the invention that the piston pump has a piston chamber for each piston, in which a piston guide is arranged with two in alignment aligned guide surfaces, on where the respective piston slidably rests.

The inventive piston pump has for Each piston has a piston chamber in which a piston guide is arranged. Each piston is a separate piston guide assigned, and the respective piston guide is in one Piston chamber of the piston pump positioned. A common piston guide for all the piston of the piston pump can thus omitted. Instead, comes for each piston a separate Piston guide for use in the respective piston chamber is integrated. Each piston guide has two guide surfaces on, which are aligned with each other and where the respective Plunger slidably applied. It has been shown that by doing the danger jamming a piston can be significantly reduced. Also including the manufacture and assembly of the piston pump the piston guide is designed relatively easy and can with larger tolerances within be carried out shortly. Because of their positioning within the piston chamber, the piston guide has practical the same temperature as the area surrounding the respective pump room the piston pump. As a result, even during during operation, mechanical stresses that cause jamming could lead the piston, kept very low can be.

From Advantage is when the piston guide two in the piston chamber comprises fixed guide elements, each one Form guide surface for the piston. The two guide elements can be axially spaced be arranged to each other. However, it can also be provided that the two guide elements lie directly against each other. This will be explained in more detail below.

Cheap it is when at least one guide element in the piston chamber is glued. Preferably, both guide elements glued into the piston chamber. This facilitates the assembly of Piston guide. Alternatively, for example, provided be that at least one guide element in the piston chamber is pressed.

Prefers is at least one guide element as the piston in the circumferential direction surrounding guide ring designed. The guide ring can easily inserted back into the piston chamber and he defines a surrounding the piston in the circumferential direction Guide surface on which the piston slidably rests.

In a preferred embodiment, at least one sealing ring is arranged between the two guide surfaces, which surrounds the piston in the circumferential direction. The sealing ring can be designed in the form of an oil seal. Preferably, the sealing ring comprises at least one sealing lip, which rests sealingly on the outer circumference of the piston. It is particularly favorable when the sealing ring is two V-shaped comprises mutually aligned sealing lips, each sealingly against the outer circumference of the piston.

at a preferred embodiment opens between the two guide surfaces a drainage hole into the piston chamber. About the drainage hole can in case of leakage liquid from the piston chamber be led out.

conveniently, is at least one guide surface of a guide element the piston guide is formed, the a piston in the circumferential direction surrounding sealing ring supported in the axial direction. The Guide element thus not only serves the leadership of the piston, but it also forms a support for a sealing ring. The sealing ring can, for example be designed in the form of a high-pressure seal, with the pump room is sealed against the piston chamber. It can also be provided that the sealing ring formed as an oil seal is that prevents the penetration of oil into the piston chamber.

Preferably is at least one sealing ring between a constriction of the piston chamber and clamped a guide element of the piston guide. The constriction may be in the form of a step. It can also be provided that the constriction is a conical or rounded Form has.

through the constriction and at a distance from this arranged guide element can a seal in a structurally simple way axially in the piston chamber be determined.

It can also be provided that a sealing ring between two guide elements is clamped, each having a guide surface train for the piston. Such a design has the advantage that a constriction of the crank chamber for supporting of the sealing ring can be omitted.

at A particularly preferred embodiment of the invention is the Assembly of the piston guide simplified by that Piston guide an insert which can be inserted into the piston chamber formed with two spaced-apart guide surfaces, where the piston is slidably engaged. The insert can according to Art a cartridge designed to be inserted into the piston chamber can be. The insert can be glued to the piston chamber. It is advantageous if the insert in addition to the both guide surfaces at least one sealing ring has, which surrounds the piston in the circumferential direction.

Preferably The insert includes a front and a rear insert, the in each case a guide element with a guide surface educate and connect with each other. The inserts can be formed sleeve-shaped, for example.

Preferably are the two inserts via a plug connection connected with each other. For example, it may be provided that one of the insert parts comprises a collar which fits into the other insert part is pluggable.

The both inserts are in a preferred embodiment latched together.

Between the two inserts is in an advantageous embodiment arranged a sealing ring of the invention. The sealing ring can be attached to a retaining ring fixed, which in turn fixed to at least one insert is. The retaining ring can be made of a metal, for example his or from a plastic material, for example a polyamide material.

From Advantage is it, if at the front insert the rear insert part turned away a sealing ring is held. The sealing ring can be used as a high-pressure seal be formed, which the pump space opposite the piston chamber seals. For this purpose, the sealing ring at least one sealing lip have, preferably obliquely to the longitudinal axis of the piston is inclined in the direction of the pumping chamber.

The following description of preferred embodiments The invention is in connection with the drawing of the closer Explanation. Show it:

1 a sectional view of a piston pump according to the invention with a first embodiment of a piston guide used in a piston chamber;

2 : A sectional view of a second embodiment of a piston guide for the piston pump 1 ;

3 : A sectional view of a third embodiment of a piston guide for the piston pump 1 and

4 : A sectional view of a fourth embodiment of a piston guide for the piston pump 1 ,

In 1 schematically is a piston pump according to the invention 10 shown. This can be placed in a conventional manner on a not shown in the drawing, per se known pump drive, which includes a swash plate on abut the piston explained in more detail below.

The piston pump 10 has several reciprocating pistons 12 on, each a piston chamber 14 go through and into a pump room 16 plunge. By the reciprocal movement of the pistons 12 can the volumes of pump rooms 16 be changed periodically. The pump rooms 16 each have a suction valve 18 with a suction line 20 in connection, via which a liquid, preferably water, can be sucked from a supply. There are also the pump rooms 16 each via a pressure valve 22 and all the pump rooms 16 common central check valve 24 with a pressure line 26 in fluid communication, in a control chamber 28 opens. To the control chamber 28 closes in the flow direction of the pressurized liquid, a connecting line 30 put in one of a discharge nozzle 32 formed outlet pipe 34 opens, to which, for example, a high-pressure hose can be connected.

Immediately downstream of the central check valve 24 branches from the pressure line 26 a bypass line 36 from, in a known per se and therefore only schematically illustrated in the drawing bypass valve 38 is arranged. The bypass line 36 connects the pressure line 26 with the suction line 20 ,

In the control chamber 28 is a control piston 40 slidably held in one piece with an injector 42 connected is. The injector 42 dives into the connection line 30 and in the usual way has a cross-sectional constriction, from which a supply line 44 branches off via a transverse bore. Via the supply line 44 and a subsequent to this connecting piece 46 For example, a chemical may be added to the pressurized fluid.

The injector 42 is on the pressure line 26 remote end face of the control piston 40 arranged. On his the pressure line 26 facing rear carries the spool 40 one parallel to the injector 42 and offset to this arranged shift rod 48 , with their free end a through hole 50 be upheld. By means of the shift rod 48 can be actuated a known per se and therefore not shown in the drawing switching device by the shift rod 48 is moved. By means of the switching device, the pump drive can be switched on and off. For this purpose, the control piston 40 frontally with the in the supply line 44 prevailing pressure and back with the upstream of the injector 42 prevailing pressure acted upon. In normal operation of the piston pump 10 becomes the injector 42 flows through pressurized liquid.

Here, the cross-sectional constriction of the injector leads 42 for generating a negative pressure in the supply line branched off from the injector 44 , The negative pressure is on the front side of the control piston 40 transferred, which is acted upon at the rear with the pressure prevailing upstream of the injector. The thus on the control piston 40 acting pressure difference has the consequence that this occupies a forward position in which the over the shift rod 48 with the control piston 40 coupled switching device remains unactuated and thus the drive of the pump is not interrupted. If the delivery of pressurized fluid is interrupted, for example by closing one to the pressure line 26 via a high-pressure hose connected dispensing device, in particular a jet pipe or a spray lance, so builds due to the first still working piston pump 10 in the pressure line 26 a very high pressure and at the same time prevents a flow through the injector 42 , so that no dynamic pressure reduction occurs in this area. This results on both sides of the control piston 40 the same pressure. As with the pressure of the supply line 44 acted upon end face of the control piston is selected to be greater than that with the pressure upstream of the injector 42 acted on back of the spool 40 , the spool becomes 40 at identical pressures pushed so far back that the switching device from the shift rod 48 is pressed. This will be the drive of the piston pump 10 switched off and a permanent high pressure load of the piston pump is avoided.

To promote the liquid, the pistons 12 driven to a float. For axial guidance of the pistons 12 In each case a piston guide is used, in the respective piston chamber 14 is arranged.

In 1 is a first embodiment of a piston guide with the reference numeral 52 busy. It comprises a first guide element in the form of a first guide ring 54 and a second guide element in the form of a second guide ring 56 , The two guide rings 54 . 56 are axially spaced from each other and support on their respective end face, the pump room 16 facing, a first sealing element 58 or a second sealing element 60 from. The first sealing element 58 is designed in the form of a high-pressure seal, the pump room 16 opposite the piston chamber 14 seals. The second sealing element 60 is designed in the form of an oil seal, which prevents the penetration of oil into the piston chamber 14 prevented. For this purpose, it has two V-shaped protruding sealing lips 61 . 62 on, on the outer circumference of the piston 12 lie sealingly.

The first sealing element 58 lies on a conical narrowing 64 the piston chamber 14 on and the second sealing element 60 is due to a gradual narrowing 65 the piston chamber 14 at. Between the first guide ring 54 and the second guide ring 56 is the piston 12 inside the piston chamber 14 from an annulus 67 Surrounded by a drainage hole 68 opens.

The two guide rings 54 and 56 each define a guide surface 70 respectively. 71 for the piston 12 that is at the guide surfaces 70 . 71 slidably applied. The guide surfaces 70 and 71 are aligned with each other. The guide rings 54 and 56 can be used for mounting the piston pump 10 at the back into the piston chamber 14 be used. For axial fixing of the guide rings 54 and 56 can this with the piston chamber 14 be glued.

In 2 a second embodiment of a piston guide is shown, in total with the reference numeral 74 is occupied. The piston guide 74 is designed in the form of a preassembled insert and includes a front insert part 75 and a rear insert 76 , which are connected to each other via a plug connection and together back into the piston chamber 14 can be used. The front insert part 75 forms at its front end a guide ring 78 out with a guide surface 79 and the rear insert 76 forms at a distance to the front guide ring 78 a rear guide ring 81 out with a rear guide surface 82 , At the two guide surfaces 79 and 82 can the piston 12 Sliding abut.

To the front guide ring 78 closes the rear insert part 76 turned away in one piece a support ring 84 on, at which the first sealing element 58 can support, with this in the direction of the pump chamber 16 is biased. The rear insert part 76 dives with a collar 86 in the front insert part 75 one in the distance to the collar 86 a step 88 having. The stage 88 forms a narrowing of the front insert part 75 out. Between the stage 88 and the front of the collar 86 is a retaining ring 90 clamped, which is a sealing ring 91 carries with two V-shaped aligned sealing lips 92 and 93 , The retaining ring 90 is made of metal, whereas the sealing ring 91 made of a plastic material.

The front insert part 75 points to the support ring 84 opposite side of the front guide ring 78 a transverse bore 95 on, after the one put the piston guide 74 into the piston chamber 14 with the drainage hole 68 the piston chamber 14 flees.

In 3 is a third embodiment of a total reference numeral 98 occupied piston guide shown, as well as in 4 illustrated piston guide is formed substantially identical to that in 2 illustrated piston guide 74 , For identical components are therefore in the 3 and 4 the same reference numerals as in 2 , With respect to these components, reference is made to the above explanations to avoid repetition.

In the 3 illustrated piston guide 98 differs from the piston guide 74 in that the two insert parts 75 and 76 at the piston guide 98 butt against each other, without a plug connection is used. The two insert parts 75 . 76 are glued together and take between them a retaining ring 99 on, on which a sealing ring 100 with V-shaped aligned sealing lips 101 . 102 is held.

In 4 is a fourth embodiment of a total reference numeral 106 occupied piston guide, in which also two interconnected via a plug connection insert parts 75 . 76 be used. At the piston guide 106 forms the step 88 of the front insert 75 in combination with the front of the collar 86 of the rear insert 76 a dovetail-shaped receptacle for a retaining ring 107 on which a sealing ring 108 with two V-shaped aligned sealing lips 109 and 110 is fixed.

The piston guides 52 . 74 . 98 and 106 make it possible in a structurally simple way, the pistons 12 the piston pump 10 reliable to perform in the axial direction without the risk that the piston 12 tilt. The assembly of the piston guides 52 . 74 . 98 and 106 makes it very easy by pushing from behind into the piston chamber 14 the piston pump 10 can be used.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 19801146 C1 [0002]

Claims (14)

Piston pump for a high-pressure cleaner with at least one pump chamber in which a reciprocating piston is immersed and which is connected via a suction valve with a suction line for sucking liquid and a pressure valve with a pressure line for discharging pressurized liquid, wherein the at least a piston is held displaceably on a piston guide, characterized in that the piston pump ( 10 ) for each piston ( 12 ) a piston chamber ( 14 ), in which a piston guide ( 52 ; 74 ; 98 ; 106 ) is arranged with two aligned mutually aligned guide surfaces ( 70 . 71 ; 79 . 82 ), at which the respective piston ( 12 ) slidingly abuts. Piston pump according to claim 1, characterized in that the piston guide ( 52 ; 74 ; 98 ; 106 ) two in the piston chamber ( 14 ) fixed guide elements ( 54 . 56 ; 78 . 81 ), each having a guide surface ( 70 . 71 ; 79 . 82 ) for the piston ( 12 ) train. Piston pump according to claim 2, characterized in that at least one guide element ( 54 . 56 ; 78 . 81 ) into the piston chamber ( 14 ) is glued. Piston pump according to claim 2 or 3, characterized in that at least one guide element as the piston ( 12 ) circumferentially surrounding guide ring ( 54 . 56 ; 78 . 81 ) is configured. Piston pump according to one of the preceding claims, characterized in that between the two guide surfaces ( 70 . 71 ; 79 . 82 ) at least one sealing ring ( 60 ; 91 ; 100 ; 108 ) is arranged, the piston ( 12 ) surrounds in the circumferential direction. Piston pump according to one of the preceding claims, characterized in that between the two guide surfaces ( 70 . 71 ; 79 . 82 ) a drainage hole ( 68 ) into the piston chamber ( 14 ). Piston pump according to one of the preceding claims, characterized in that at least one guide surface ( 70 . 71 ; 79 . 82 ) of a guide element ( 54 . 56 ; 78 . 81 ) of the piston guide ( 52 ; 74 ; 98 ; 106 ) is formed, wherein the guide element ( 54 . 56 ; 78 . 81 ) a the piston ( 12 ) circumferentially surrounding sealing ring ( 58 . 60 ; 91 ; 100 ; 108 ) is supported in the axial direction. Piston pump according to claim 7, characterized in that at least one sealing ring ( 58 . 60 ) between a narrowing ( 64 . 65 ) of the piston chamber ( 14 ) and a guide element ( 54 . 56 ) of the piston guide ( 52 ) is clamped. Piston pump according to claim 7 or 8, characterized in that a sealing ring ( 91 ; 100 ; 108 ) between two guide elements ( 78 . 81 ), each having a guide surface ( 79 . 82 ) for the piston ( 12 ) train. Piston pump according to one of the preceding claims, characterized in that the piston guide ( 74 ; 98 ; 106 ) into the piston chamber ( 14 ) usable insert forms with two spaced apart guide surfaces ( 79 . 82 ), on which the piston ( 12 ) slidingly abuts. Piston pump according to claim 10, characterized in that the insert a front and a rear insert part ( 75 . 76 ), each having a guide element ( 78 . 81 ) with a guide surface ( 79 . 82 ) and are connected to each other. Piston pump according to claim 11, characterized in that the two insert parts ( 75 . 76 ) are connected to each other via a plug connection. Piston pump according to claim 11 or 12, characterized in that between the two insert parts ( 75 . 76 ) a sealing ring ( 91 ; 100 ; 108 ) is arranged. Piston pump according to claim 11, 12 or 13, characterized in that on the front insert part ( 75 ) the rear insert part ( 76 ) facing away from a sealing ring ( 58 ) is held.