EP1175563B1 - Membrane pump comprising an inlet opening that is controlled by the membrane - Google Patents

Abstract

A membrane pump (1) having a membrane (24) which can be actuated by a crank drive (32), which membrane bounds, together with a concave pump body surface (8), a pump chamber (38), an inlet channel (4) and an outlet channel (17) which open out at an inlet opening (9) and an outlet opening (20) in the pump body surface (8), the membrane (24) having a membrane core (25) and an elastically deformable membrane ring (26) and the membrane core (26) having a convex surface adapted to the pump body surface (8). The inlet opening (9) is arranged in the region of the pump body surface (8) which the membrane (24) first approaches upon an expulsion stroke of the crank drive (32), and the elastically deformable membrane ring (26) closes the inlet opening (9) before the attainment of top dead center of the crank drive (32).

Description

The invention relates to a diaphragm pump according to the genus Main claim.

From the utility model G 9406216 is a diaphragm pump of the genus Claim 1 known. The diaphragm pump resulting from this utility model has a membrane which can be actuated by a crank drive and which is connected to an outer Membrane annulus is attached to a pump body of a pump housing. Next the outer membrane circular ring, the membrane has a membrane core that over an elastically deformable membrane ring with the outer membrane ring connected is. The membrane closes with one formed on the pump body Pump body area a pump chamber (scoop chamber). Are in the pump body an inlet channel and an outlet channel formed at an inlet opening and a Open the outlet opening in the surface of the pump body. The inlet duct and the Outlet channels are preferably with outside of the pump body Flow direction valves connected, creating a flow direction through the Inlet channel and the outlet channel is predetermined. During an intake stroke of the Crank drive is a pump medium through the inlet channel into the pump chamber is conveyed and in a subsequent ejection stroke of the crank drive that Pump medium is displaced from the pump chamber via the outlet channel.

A disadvantage of the diaphragm pump known from utility model G 9406216 is that during the ejection stroke part of what is in the pump chamber Pump medium is pressed back into the inlet channel or compressed therein. In particular with a compressible pressure medium, the deteriorates Efficiency of the diaphragm pump considerably. Another disadvantage is that the Exhaust opening is throttled depending on the stroke position of the crank drive, the throttling before reaching the top dead center position of the crank drive increases, so that at the end of the discharge stroke the highly compressed pump medium can escape increasingly poorly.

In summary, one can in the known diaphragm pump Compression ratio of the diaphragm pump does not correspond to the amount of pump medium Eject completely from the pump chamber via the outlet opening. Also suitable the known diaphragm pump is only limited for compressible pumping medium such as. Gases.

US 3,947,156 discloses a diaphragm pump according to the preamble of Claim 1.

Starting from this known diaphragm pump, the present invention is the The task is to propose a diaphragm pump that is as large as possible Compression ratio of the pump medium in the pump chamber allowed and on enables reliable closing of the inlet opening by the membrane ring.

The object is achieved by the diaphragm pump according to the invention characteristic features of the main claim solved. Advantageous further training the invention are described in the subclaims.

Due to the peripheral control edge formed in the edge region of the inlet opening, at which the elastically deformable membrane ring closes the inlet opening, the Inlet opening reliably and closed on all sides.

It is advantageous that the center of the inlet opening at least approximately in the Rotation level of the crank of the crank drive is. As a result, the inlet opening of the Inlet duct closed particularly early.

The elastically deformable membrane ring advantageously closes the Inlet opening at a crank rotational position of the crank drive, which is up to 90 ° before top dead center. As a result, the membrane is deflected from a maximum the diaphragm pump reaches a seal.

The elastically deformable membrane ring advantageously closes the Inlet opening at a crank rotational position of the crank drive, which is 20 ° to 90 ° in front of the top dead center. This will seal the inlet opening of the Inlet channel from a maximum deflection of the membrane of the membrane pump reached, with a closed inlet opening of the inlet channel, part of the Crank rotation is available to more compression the To achieve pump medium.

It is advantageous if the inlet valve has a valve plate, which Inlet opening covered. By the valve plate directly at the inlet opening of the Inlet channel is arranged can further reduce the dead volume of the inlet channel become. It is particularly advantageous if the central axis of the inlet channel is oriented perpendicular to the pump body surface. This is the structural Design of the directional valve and the introduction of the valve plate in the Inlet channel simplified.

The outlet opening of the outlet channel is advantageously in a region of the Pump body surface arranged, the diaphragm last approaches and that of the diaphragm is reached at the earliest at the top dead center position of the crank drive is. It is thereby achieved that the pump medium from the pump chamber is as possible can be pumped unthrottled into the outlet channel. It is also achieved that the outlet opening of the outlet channel is not already before reaching the upper one Dead center position of the crank drive is closed.

It is advantageous that the center of the outlet opening of the outlet channel in one inner area of the pump body surface is arranged, the membrane core of the Membrane is opposite. Because in the crank movement of the crank drive Pump medium due to the movement of the membrane core last from an over pumped out the region of the pump chamber arranged in the membrane core of the membrane the outlet opening of the outlet channel is thereby arranged particularly favorably.

Figur 1 einen axialen Schnitt durch ein Ausführungsbeispiel einer erfindungsgemäßen Membranpumpe in der oberen Totpunktstellung des Kurbelantriebs;

Figur 2 das Ausführungsbeispiel bei einer Kurbeldrehstellung, die 50° nach der oberen Totpunktlage liegt;

Figur 3 das Ausführungsbeispiel in der unteren Totpunktlage; und

Figur 4 das Ausführungsbeispiel bei einer Drehkurbelstellung des Kurbelantriebs, der 50° vor der oberen Totpunktlage liegt.

Exemplary embodiments of the invention are shown in simplified form in the drawings and are explained in more detail in the description below. Show it:

Figure 1 shows an axial section through an embodiment of a diaphragm pump according to the invention in the top dead center position of the crank drive;

Figure 2 shows the embodiment in a crank rotational position, which is 50 ° after the top dead center position;

Figure 3 shows the embodiment in the bottom dead center position; and

Figure 4 shows the embodiment with a crank position of the crank drive, which is 50 ° before the top dead center position.

Description of the embodiment

Figure 1 shows an extract according to the invention in a sectional view Diaphragm pump 1. The diaphragm pump 1 can be used in particular as a vacuum pump or as a pressure pump for pumping pump media, e.g. Liquids and gases, be used. However, the diaphragm pump 1 according to the invention is also suitable for other use cases.

The diaphragm pump 1 has a pump body 2 which is connected to a housing element 3 is connected. The pump body 2 has an inlet channel 4, which in this Exemplary embodiment by stepped bores 5a, 5b, 5c and an oblique bore 6 is trained. A central axis 7 of the oblique bore 6 of the inlet channel 4 is there perpendicular to a pump body surface 8 formed on the pump body 2 oriented. The inlet channel 4 opens at an inlet opening 9 in the Pump body surface 8. The inlet opening 9 is in an outer region of the Pump room, i.e. near the clamping of the membrane in the pump body 2 arranged. Furthermore, the center of the inlet opening 9 is advantageously in the plane of rotation or pivoting of the crank 31 of the crank drive 32. It should be noted that the pivot plane of the crank 31 coincides with the sectional plane of Figure 1. By arranging the inlet opening in an outer region of the pump chamber and in the swivel plane of the crank 31, an early closure of the Inlet opening 9 when ejecting the pump medium from the pump chamber through the Membrane achieved. The pump medium is closed as soon as the Inlet opening 9 is no longer conveyed into the pump chamber via the inlet channel 4. The From this point on, the inlet channel is no longer effective as a harmful area. hereby therefore an improvement and optimization of the pumping process is achieved.

In the area of the inlet opening 9, i.e. facing the pump room is a directional or inlet valve arranged. The inlet valve consists in the illustrated Embodiment of a valve plate 10 which in the region of the inlet opening 9 of the Inlet channel 4 is arranged to form the directional valve or inlet valve. in the The area of the inlet opening 9 has the oblique bore 6 of the pump body 2 Pump room directed up to a circumferential pocket that has a larger diameter than the oblique hole has 6. The valve plate 10 is supported on one between the Inclined hole 6 and the pocket formed peripheral edge 11. The valve plate 10 is substantially flush with the pump body surface 8, at least while it is from the membrane is closed, whereby between the circumferential groove in the Inclined bore 6 and the pump body surface 8 results in a control edge 35. With in other words, in the edge region of the inlet opening 9 there is a circumferential and Control edge 35 protruding slightly beyond the valve plate, on which the Membrane closes the inlet opening 9. The circumferential control edge 35 ensures in an advantageous manner that the inlet valve with the valve plate 10 during the exhaust stroke is securely and reliably closed on all sides. The arrangement of the intake valve with the valve plate 10 directly in the area of the inlet opening 9 and the immediate Closing the inlet valve through the membrane during the exhaust stroke reduces the Damage space continues on the exhaust stroke and thus contributes to a further increase in Efficiency and reliability of the pump.

An outlet element 16 is screwed into a thread 15 in the pump body 2, which has stepped bores 18a to 18d, which together with a Outlet recess 19 form an outlet channel 17. The outlet element 16 can also inserted and fastened by screws. The outlet channel 17 opens into one Outlet opening 20 into the pump body surface 8. Between the outlet recess 19 and the bore 18d is formed by a valve plate 21, a directional valve. The Exhaust valve with the valve plate 21 is in the area of the outlet recess 19 for Pump room arranged facing, which further improves the Pump effect is achieved. The outlet opening 20 is from the edge of the pump chamber The center is offset such that the outlet opening 20 during the exhaust stroke is closed as late as possible. In other words, the outlet opening is 20 in an area arranged last from the membrane at the end of the exhaust stroke is covered.

Both the inlet valve with the valve plate 10 and the outlet valve with the Valve plate 21 are advantageously designed as freely movable valves, which at switch the lowest possible pressure differences in order to avoid compression losses and thus causing an indirect increase in the harmful volume. The valves are not biased in any direction by a clamp or tie, thereby additional forces for switching the valves would be necessary, but freely movable educated. However, so that the valves after lifting off their valve seat, i.e. after opening, at the end of the flow process again if possible to be returned stress-free to their respective seat is one accordingly trained valve holding device provided. It is both in the inlet valve also important for the exhaust valve that the clamping of the valve plates 10 and 21 are stress-free, i.e. the valve is near the closed valve position as stress-free as possible, so that small pressure differences for closing or sufficient to open. If the valve is deflected or opened, the valve is created Tensions by which it is biased towards the closed position. in the The present exemplary embodiment includes two bolts for the inlet valve a thin retaining collar is provided on both sides of the inlet opening 9. The Inlet valve has elongated or oval mounting holes through which the bolts protrude. When the valve is opened, the valve plate is thus along the holes flexible and allows bending outwards into the pump chamber. The same applies to the outlet valve through the bore 18d in the outlet element 16 reached. The bore 18d is a preferably circumferential groove, which is in the outlet element 16 directed towards the seat of the valve plate 21 and the valve plate 21 one allows free opening movement away from the pump room.

The membrane has a membrane core 25, an elastically deformable Membrane ring 26 and an outer membrane circular ring 27, the membrane 24th on the outer membrane ring 27 between the pump body 2 and the Housing element 3 is attached. The membrane is in the unclamped state essentially flat and is between the pump body 2 and the Housing element 3 clamped that the membrane towards Pump body surface 8 is biased. For this purpose, the membrane becomes tangential-globular clamped, as can be seen in Figures 1 to 4. For this, the concave Pump body surface 8 also in the area of the clamping of the diaphragm ring 27 continued so that the membrane at least in the outer region, i.e. in the area of the diaphragm ring 27 at the edge regions of the concave pump body surface 8 is applied. This also ensures reliable closing of the inlet valve by the Membrane guaranteed. The tangential-global clamping of the membrane avoids that in known pumps usually in the area of Membrane clamping existing flat annular damage space, which from a insufficient membrane flexibility and pressure build-up in the pump Outlet process and consequently the bulging of the membrane away from the Pump chamber comes from. The diaphragm pump according to the invention is designed so that the compression ratio, i.e. the ratio of maximum to minimum Pump chamber volume is optimized. Since the compression ratio is particularly different from that minimum achievable pump chamber volume is dependent and therefore determined by it is how well the elastic membrane can close off the pump chamber the properties of the diaphragm pump according to the invention described above an optimization has been achieved in this regard. Furthermore, the arrangement and Design of the intake valve and the exhaust valve the volumes in the Flow channels minimized, so that there is a greatly improved pumping effect. In a core 28 is vulcanized into the membrane core 25 of the membrane 24, one plate-shaped section 29 and a cylindrical section 30. about a connecting device 31 is the cylindrical section 30 of the mandrel 28 connected to a crank 31 of a crank drive 32.

As mentioned above, there is a circumferential one in the edge region of the inlet opening 9 Control edge 35 formed on which the elastically deformable membrane ring 26 die Inlet opening 9 closes.

The exemplary embodiment of the diaphragm pump from FIG. 1 is shown in FIGS different crank rotational positions of the crank drive shown. Through the Continuous observation of Figures 1 to 4 can give an impression of that Win the sequence of movements of the diaphragm pump 1. 1 is the Crank rotation position of the diaphragm pump at an upper dead center, in Figure 2 after 50 ° top dead center, in FIG. 3 at bottom dead center and in FIG. 5 50 ° in front of one shown top dead center. Since in Figures 2 to 4, the elements shown with 1 correspond to a repetitive description waived.

In Figure 2, the crank rotational position of the crank drive 32 after a rotation of the Crank drive 32 shown in a direction of rotation 36 by 50 °. This will make the axis 37 of the membrane core 25 with respect to the axis 39 of the concave pump body surface 8 tilted. As a result, the membrane core 25 initially lifts on the side of the Inlet opening 9 from the pump body surface 8, wherein it in the area of Outlet opening 20 initially remains in contact with the pump body surface 8. In this The exemplary embodiment is the inlet opening 9 of the inlet channel 4 in the case of FIG. 2 shown crank rotation position of the elastically deformable membrane ring 26 of the Membrane 24 closed. The membrane ring 26 and / or the pump body surface 8 can also be designed so that the inlet opening 9 of the inlet channel 4 at the in Figure 2 shown crank position of the crank drive 32 is already open. in the general is at a rotary crank position of the crank drive 32, the 90 ° after the top dead center position, the inlet opening 9 of the inlet channel 4 is open. The Membrane 24 is lifted by the rotary crank movement of the crank drive 32 Pump body surface 8, whereby a between the membrane 24 and the Pump body area 8 formed pump chamber 38 enlarged and from the opening of the Inlet opening 9 of the inlet channel 4 a pumping medium from the inlet channel 4 through the Inlet opening 9 is sucked into the pump chamber 38. When sucking in Pump medium flows from the inlet channel 4 into the pump chamber 38, the pump medium by the directional valve formed by the valve plate 10. Likewise, in that Outlet channel 17 through the valve plate 21, a directional valve is formed, so that a the side of the sealing plate 21 facing away from the outlet opening 20 Pump medium does not enter the pump chamber 38 during the intake stroke of the crank drive 32 flowing back.

In Figure 3, the diaphragm pump 1 at a bottom dead center Crank drive 32 shown. Compared to the top dead center position in Figure 1, the Crank drive 32 of the diaphragm pump 1 a rotation in the direction of rotation 36 of 180 ° completed. In this position there is an at least approximately maximum volume of the Pump room 38 given. The membrane 24 is therefore only in the area of the outer Membrane circular ring 27, on which they with the pump body 2 and the housing element 3 is connected to. As a result, the inlet opening 9 of the inlet channel 4 and the Outlet opening 20 of outlet channel 17 fully opened,

The crank rotary position of the diaphragm pump 1 shown in FIG. 3 is included Ejection stroke of the membrane 24, whereby the pump medium in the pump chamber 38 compressed and via the outlet opening 20 of the outlet channel 17 from the Diaphragm pump 1 is ejected. It is achieved by the valve plate 10 that the pump medium from the pump chamber 38 does not flow back into the inlet channel 4.

As the discharge stroke increases, the diaphragm 24 approaches the pump body surface 8. In Figure 4, a rotary crank position of the crank drive 32 is shown, which is 50 ° before The top dead center position of the rotary crank drive 32 shown in FIG. there the axis 37 is tilted relative to the axis 39 of the pump body surface 8, the Tilting opposite to the tilting in Figure 2 takes place. This is approaching the membrane 24 first of the inlet opening 9 of the inlet channel 4, wherein in the shown angular position of the crank drive 32, the inlet opening 9 already from the elastically deformable membrane ring 26 is closed. In addition, the Pump chamber 38 from the inlet opening to the outlet opening 20 of the outlet channel 17 itself widened so that the pump medium from the pump chamber 38 at the further rotary movement of the crank drive 32 preferably in the area of Exhaust opening 20 of the outlet channel 17 collects, causing a complete pumping out of the pump medium from the pump chamber 38 into the outlet channel 17.

By the early closing of the inlet opening 9 of the inlet channel 4 with the Membrane ring 26 is achieved that in the inlet channel 4 on the pump chamber 38th Subsequent dead volume is closed, so that a in the inlet channel 4th existing pumping medium due to the further ejection stroke of the crank drive is further compressed and the exhaust stroke fully to compress the over the pump medium to be pumped out can be used. It is particularly advantageous if the valve plate 10 in the inlet channel 4 is close is positioned at the inlet opening 9, since this already before the Inlet opening 9 with the diaphragm ring 26, the dead volume is reduced. The Outlet opening 20 of the outlet channel 17 is in one in this embodiment Area of the pump body surface 8, which the membrane 24 approaches last and that of the membrane 24 at the earliest at the top dead center position of the Crank drive 32 is reached. It is thereby achieved that the outlet opening 20 only after the ejection stroke of the crank drive 32 can be closed. In order to the outlet opening 20 is not partially from the diaphragm ring 26 of the diaphragm 24 is closed and thus a pump medium flow of the pump medium when pumping out is not throttled in the outlet opening 17, it is particularly advantageous that the center of the outlet opening 20 of the outlet channel 17 in an inner Area of the pump body surface 8 is arranged, the membrane core 25 of the Membrane 24 is opposite.

The invention is not restricted to the exemplary embodiment described.

LIST OF REFERENCE NUMBERS

1

diaphragm pump

2

pump body

3

housing element

4

intake port

5

drilling

6

oblique bore

7

central axis

8th

Pump body surface

9

inlet port

10

valve plate

11

All-round edge

15

thread

16

outlet member

17

outlet channel

18

drilling

19

outlet recess

20

outlet

21

valve plate

24

membrane

25

diaphragm core

26

diaphragm ring

27

Outer membrane circular ring.

28

mold core

29

Plate-shaped section

30

Cylindrical section

32

crank drive

33

connecting device

35

control edge

36

direction of rotation

37

axis

38

pump chamber

39

axis

Claims (8)

1. Membrane pump (1) with a membrane (24), which can be activated by a crank drive (32) and which, together with a concave surface (8) of the pump body, encloses a pump chamber (38); with an inlet channel (4) and an outlet channel (17), which open into an inlet opening (9) and an outlet opening (20) in the surface (8) of the pump body, the membrane (24) providing a membrane core (25) and a resiliently deformable membrane ring (26), and the membrane core (25) providing a convex surface adapted to the surface (8) of the pump body, wherein
   the inlet opening (9) is disposed in the region of the surface (8) of the pump body, which is first approached by the membrane (24) during the expulsion stroke of the crank drive (32),
   and wherein
   the resiliently deformable membrane ring (26) closes the inlet opening (9) before reaching the top-dead-centre position of the crank drive (32),
   characterised in that
   an inlet valve disposed in the inlet channel (4) in the region of the inlet opening (9) is provided, a circumferential control edge (35) being formed in the edge region of the inlet opening (9), against which the resiliently deformable membrane ring (26) closes the inlet valve.
2. Membrane pump according to claim 1,
   characterised in that
   the inlet valve provides a valve plate (10), which covers the inlet opening (9).
3. Membrane pump according to claim 1 or 2,
   characterised in that
   the centre point of the inlet opening (9) is located at least approximately in the rotational plane of the crank (31) of the crank drive (32).
4. Membrane pump according to any one of claims 1 to 3,
   characterised in that
   the resiliently deformable membrane ring (26) closes the inlet opening (9) at a rotational position of the crank drive (32), which is located up to 90° before the top-dead-centre position.
5. Membrane pump according to claim 4,
   characterised in that
   the resiliently deformable membrane ring (26) closes the inlet opening (9) at a rotational position of the crank drive (32), which is located 20° to 90° before the top-dead-centre position.
6. Membrane pump according to any one of claims 1 to 5,
   characterised in that
   the central axis (7) of the inlet channel (4) is orientated perpendicular to the surface (8) of the pump body.
7. Membrane pump according to any one of claims 1 to 6,
   characterised in that
   the outlet opening (20) of the outlet channel (17) is disposed in a region of the surface (8) of the pump body which is approached last by the membrane (24), and which is reached by the membrane (24) at the soonest at the top-dead-centre position of the crank drive (32).
8. Membrane pump according to any one of claims 1 to 7,
      characterised in that,
   the centre point of the outlet opening (20) in the outlet channel (17) is disposed in an inner region of the surface (8) of the pump body, which is located opposite to the membrane core (25) of the membrane (24).

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