EP2486264B1 - Hand pump for pumping fluids, and filter system for fluids, comprising a hand pump - Google Patents

Description

Technical area

The invention relates to a hand pump according to claim 1.

The invention further relates to a filter system for liquids according to claim 10.

State of the art

Fuel supply systems for internal combustion engines are often provided with generic hand pumps, which serve to facilitate the re-start when empty tank or after replacing a fuel filter. Such hand pumps are often structurally associated with a filter head for connection of the fuel filter. A generic hand pump is from the US 5,362,392 A1 known.

From the US 6,019,890 A For example, a hand pump for delivering fuel in a fuel delivery system is known, wherein the hand pump is structurally associated with a fuel filter. A housing lower part of the fuel pump is formed on a connection head for the fuel filter. On the lower housing part a lid is attached by means of a retaining ring. Between the lower housing part and the lid, the peripheral wall of a membrane is clamped in a holding region, which extends substantially along the inside of the lid. A radially inner region of the membrane is clamped in an attachment area between the lower plate of a knob and a support plate. To pump the knob is pressed against a spring preload and thus reduces the volume of a pump chamber. The attachment area always remains on one side of the holding area, so that the lifting height is correspondingly limited and a large part of the possible stroke volume remains unused.

The invention has the object of providing a hand pump and a filter system with a hand pump of the type mentioned in such a way that the largest possible displacement is realized with the smallest possible space.

Disclosure of the invention

This object is achieved in that the holding region of the pump housing is considered axially to Hubachse between the position of the mounting portion in the rest position and the position of the mounting portion in the operating position.

According to the invention, therefore, the actuating body is moved beyond the retaining area during a stroke with the fastening area. In this way, the freedom of movement of the membrane is optimally utilized and thus maximizing the achievable with a given space displacement. Characterized in that the lifting height is greater than the smallest possible distance between the holding portion and the mounting portion, the gap between a radially inner peripheral side of the pump housing and a radially outer peripheral side of the actuating body is minimized. Preferably, the width of the gap is less than 5 mm. The membrane is optimally supported by the mounting area with the largest possible diameter against changing pressure loads, which has a positive effect on the stroke volume. When sucking in the liquid, a negative pressure prevails in the pump chamber in relation to a pressure in a liquid feed line. When pumping out the liquid from the pump chamber, there is an overpressure against a pressure in a liquid discharge.

In an advantageous embodiment, the holding region of the pump housing may be located centrally between the position of the fastening region in the rest position and the position of the fastening region in the actuating position of the actuating body. In this way, the axial deflection of the actuating body on both sides of the holding area is the same, so that the lifting height can be maximized and the available space is optimally utilized.

Advantageously, the ring portion of the membrane may be curved and everted, in particular the membrane may be a rolling membrane. So It is possible that the ring section can be everted with little effort in the gap between the mounting portion in the holding area when passing the holding portion. A rolling membrane can easily be everted even with minimal gap widths.

The membrane may advantageously be made of an elastomer. Elastomers are flexible, robust and can easily be designed into complex shapes.

Advantageously, the membrane may have a circumferential sealing bead which is clamped between a cover and a housing lower part of the pump housing. In this way, a good seal between the membrane and the pump housing is achieved, so that the escape of liquid is excluded from the holding area.

According to a further advantageous embodiment, the actuating body may comprise an outer cap, on or in which a support cap is arranged, and the membrane may be clamped between the outer cap and the support cap. The membrane can be clamped flat and stable between the outer cap and the support cap in the region of its center. A separate seal in the mounting area is not required. But there is also the possibility that the membrane is designed as a ring element and only a radially inner region of the ring member between the knob and the support cap is tightly clamped. The membrane is optimized in terms of material usage.

Alternatively, advantageously, the actuating body may have a knob and the membrane may be molded onto the knob and designed as a ring element. A ring element is optimized with respect to the material used. The hand pump according to the invention is thus made of fewer parts and is easier to assemble.

Advantageously, the hand pump can be integrated in a filter system for liquids, in particular a filter head. In filter systems, it is particularly advantageous if the components used require as little space as possible. Here, the hand pump according to the invention with an optimal ratio between the stroke volume and space has a particularly favorable.

The technical object is further achieved according to the invention in that, in the case of the hand pump of the filter system, the holding region of the pump housing, viewed axially relative to the lifting axis, lies between the position of the fastening region in the rest position and the position of the fastening region in the actuating position. The above-enumerated advantages of the hand pump according to the invention apply correspondingly to the filter system according to the invention.

Brief description of the drawings

Figur 1

schematisch einen Schnitt einer Handpumpe, die in einem Filterkopf eines Kraftstofffiltersystems integriert ist;

Figur 2

schematisch einen Schnitt der Handpumpe aus der Figur 1 während der Betätigung;

Figur 3

schematisch einen anderen Schnitt der Handpumpe aus der Figur 1.

Further advantages, features and details of the invention will become apparent from the following description in which an embodiment of the invention with reference to the drawings is explained in more detail. Show it

FIG. 1

schematically a section of a hand pump, which is integrated in a filter head of a fuel filter system;

FIG. 2

schematically a section of the hand pump from the FIG. 1 during the operation;

FIG. 3

schematically another section of the hand pump from the FIG. 1 ,

In the figures, the same components are provided with the same reference numerals.

Embodiment of the invention

In FIG. 1 a section of a fuel filter system 10 of an internal combustion engine of a motor vehicle is shown. The fuel filter system 10 comprises a filter head 12 to which a replaceable filter 14 of no further interest is mounted.

In the filter head 12, a hand pump 16 is integrated. The hand pump 16 is used for manual suction of the fuel from a tank, for example, after replacement of the replaceable filter 14 or before a restart of the internal combustion engine at leergefahrenem tank.

In the filter head 12, an intake pipe 18 of the hand pump 16 is arranged. The suction pipe 18 is in the section in the FIG. 3 visible, noticeable. The suction line 18 is connected to a fuel supply line, not shown in the figures, which comes from the tank, and opens into a pump chamber 20 of a pump housing 22 of the hand pump 16. In the suction line 18, an inlet check valve 24 is arranged, which for sucking fuel into the pump chamber 20 opens.

One in the FIGS. 1 and 2 shown pressure line 26 of the hand pump 16 connects the pump chamber 20 with an inlet 28 of the interchangeable filter 14. In the pressure line 26, an outlet check valve 30 is arranged, which opens for pumping fuel from the pumping chamber 20 into the replaceable filter 14.

In the pump housing 22 a generally designated by the reference numeral 32 knob 32 is mounted axially movable to a stroke axis 34. The knob 32 consists of an outer cap 36 and a support cap 38.

The outer cap 36 is a total of approximately cup-shaped. At the free end face of the outer cap 36, a radial flange 40 is integrally formed. The support cap 38 is also approximately cup-shaped. It has at its free end face on a radial counter flange 42, the radially outer edge is bent at right angles from the bottom 44 of the support cap 38 away. The support cap 38 is inserted in the outer cap 36, wherein an approximately cup-shaped, graduated in its peripheral side membrane 46 made of rubber between the support cap 38 and the outer cap 36 is clamped.

A domed ring portion 48 of the diaphragm 46 surrounds a mounting portion 50 of the knob 32 for the diaphragm 46 between the flange 40 and the mating flange 42.

The annular portion 48 has at the radially outer edge of the membrane 46 has a circumferential sealing bead 52. The sealing bead 52 is clamped in a holding region 54 between a cover 56 and an upper edge of a housing lower part 58 of the pump housing 22 and at the same time assumes a sealing function. The pump housing 22 is sealingly closed by beading the lid 56 at the edge.

The provided with the membrane 46 knob 32 protrudes through an opening 60 in the lid 56 to the outside, wherein the radial flange 40 rests inside the lid 56. The ring portion 48 of the membrane 46 extends from the holding portion 54 to the mounting portion 50 and lies in the in FIGS. 1 and 3 shown rest position I of the knob 32 on the lid 56 at.

Starting from the inside of the bottom 44 of the support cap 38, a cylinder portion 62 extends, which is arranged concentrically to the lifting axis 34. The axial extent of the cylinder portion 62 corresponds approximately to the axial extent of the support cap 38.

The lower housing part 58 comprises a cylindrical wall portion 64, at the lower end of a bottom 66 is inserted. The bottom 66, the cylindrical wall portion 64, the diaphragm 46 and the knob 32 define the pump chamber 20, the volume of which by pressing the Knobs 32 and corresponding movement of the diaphragm 46 is variable.

On the floor 66 are in concentric alignment with the cylinder portion 62 of the support cap 38 two guide elements 68. In a limited by the guide elements 68 cylindrical interior is the cylinder portion 62. The guide elements 68 are over their entire extent in the direction of the lifting axis 34 through two passage gaps 70, in the FIGS. 1 and 2 aligned, separated from each other. Through the passage gaps 70, fuel can pass from the region of the pump chamber 20 surrounding the guide elements 68 into the interior.

The guide elements 68 and the cylinder section 62 are surrounded by a helical compression spring 72. The compression coil spring 72 is supported on the one hand on the inside of the bottom 66 of the lower housing part 58 and on the other hand on the inside of the bottom 44 of the support cap 38.

For pumping fuel, the knob 32 with the diaphragm 46 against the force of the compression coil spring 72 from the rest position I in an operating position II, in the FIG. 2 is shown pressed into the pump chamber 20. In the FIG. 1 is the position of the mounting portion 50 in the rest position I indicated by a dashed line 73 and in the operating position II with a dashed line 75. The holding portion 54 of the pump housing 22 is located axially to the stroke axis 34 viewed centrally between the position 73 of the mounting portion 50 in the rest position I and the position 75 of the mounting portion 50 in the operating position II of the knob 32. In this way, the flexibility of the diaphragm 46 is fully utilized and a maximum lifting height, which in the FIG. 1 indicated by a double arrow 77, and so reaches a maximum displacement. The lifting height 77 of the knob 32 is greater than the smallest possible distance between the holding portion 54 and the mounting portion 50 at a stroke FIG. 1 with the double arrow 74 indicated width of the remaining between the holding portion 54 and the mounting portion 50 gap 74 is preferably less than 5 mm.

When the knob 32 is pressed in, the ring section 48 of the diaphragm 46 configured as a rolling diaphragm is everted by means of a rolling change in shape. The volume of the pump chamber 20 decreases and the pressure in the pump chamber 20 increases. This pressure increase causes the exit check valve 30 to open, pumping fuel from the pump chamber 20 through the pressure line 26.

After completion of the downward stroke of the knob 32 and the power application ends by the hand of the operator. Due to the restoring force, the helical compression spring 72 pushes the knob 32 out of the pump chamber 20 until the radial flange 40 rests against the cover 56. In this case, the ring portion 48 of the membrane 46 is everted into its original shape. The volume of the pump chamber 20 increases and it creates a negative pressure. The negative pressure causes opening of the inlet check valve 24, so that fuel flows through the suction line 18 into the pumping chamber 20.

In the above-described embodiment of a fuel filter system 10 and a hand pump 16, the following modifications are possible, inter alia:

The fuel filter system 10, in particular the manual pump 16, is not limited to use in internal combustion engines in the automotive sector. Rather, it can also be used in other types of internal combustion engines, such as industrial engines. However, the fuel filter system 10 and the hand pump 16 can also be used in other technical fields, for example in water technology for filtering or for sucking water.

Instead of being integrated in the filter head 12, the hand pump 16 can also be designed as a separate functional component. The hand pump 16 may also be disposed elsewhere in the fuel filter system 10.

The holding region 54 of the pump housing 22 may also lie closer to one of the positions 73 or 75 instead of centrally between the respective position 73 or 75 of the fastening region 50 in the rest position I and the actuating position II.

The membrane 46 may be made of a different type of flexible material, in particular a different type of elastomer instead of rubber.

The support cap 38 may be plugged into the outer cap 36 and plugged onto this.

According to an embodiment not according to the invention, instead of being clamped between the outer cap 36 and the supporting cap 38, the membrane 46 may also be injection-molded onto a corresponding pommel and designed as a ring element.

Instead of the knob 32 with outer cap 36 and support cap 38 and a different kind particular one-piece knob can be provided.

Instead of the helical compression spring 72 may also be provided a different type of spring or a different kind of elastic element.

Claims (9)

1. Hand pump (16) for pumping liquids, in particular fuel, in particular of a motor vehicle, with a pump housing (22) having an inlet (18) and an outlet (26) for the liquid and an actuating body (32) movably mounted axially therein in relation to a stroke axis (34) as well as a diaphragm (46) with a flexible ring section (48) surrounding the stroke axis (34) and which is attached radially inside in an attachment area (50) of the actuating body (32) and radially outside in a holding area (54) of the pump housing (22), the actuating body (32) being pressed with the diaphragm (46) into the pump housing (22) during a stroke movement against the force of a resilient element (42) from a rest position (I) into an actuating position (II) and again being drawn out into the rest position (I) by means of the resilient element (72) and thus the volume of a pump chamber (20) being capable to be changed, a stroke height (77) of the actuating body (32) being larger than a smallest radial distance (74) during a stroke between the holding area (54) and the attachment area (50), the holding area (54) of the pump housing (22) seen axially in relation to the stroke axis (34) being located between the position (73) of the attachment area (50) in the rest position (I) and the position (75) of the attachment area (50) in the actuating position (II), the actuating body (32) being designed as knob with an outer cap (36) and a support cap (38), the diaphragm (46) being clamped between the outer cap (36) and the support cap (38) inserted therein, and the support cap (38) featuring a bottom (44), from the interior side of which extends a cylinder section (62), characterized in that the pump housing (22) comprises a housing lower part (58) with a bottom (66) and that two guide elements (68) are located on the bottom (66) in concentric alignment in relation to a cylinder section (62) of the support cap (38) which define a cylindrical interior space in which is located the cylinder section (62) and which are separated from each other over their complete extension in the direction of the stroke axis (34) by means of passage gaps (70) and designed in such a way that fuel can reach the interior space through the passage gaps (70) from the area of the pump chamber (20) surrounding the guide elements (68).
2. Hand pump according to claim 1, the guide elements (68) and the cylinder section (62) being surrounded by a coil spring (72), which is, on the one hand, supported by the interior side of the bottom (66) of the housing lower part (58) and, on the other hand, by the interior side of the bottom (44) of the support cap (38).
3. Hand pump according to claim 1 or 2, characterized in that the holding area (54) of the pump housing (22) is located centrally between the position (73) of the attachment area (50) in the rest position (I) and the position (75) of the attachment area (50) in the actuating position (II) of the actuating body (32).
4. Hand pump according to one of the above claims, characterized in that the ring section (48) of the diaphragm (46) is domed and invertible, in particular that the diaphragm (46) is a rolling diaphragm.
5. Hand pump according to one of the above claims, characterized in that the diaphragm (46) is made of an elastomer.
6. Hand pump according to one of the above claims, characterized in that the diaphragm (46) features a circumferential sealing bead (52), which is clamped between a cover (56) and a housing lower part (58) of the pump housing (22).
7. Hand pump according to one of the above claims, characterized in that the actuating body (32) features an outer cap (36), on or in which a support cap (38) is disposed, and that the diaphragm (46) is clamped between the outer cap (36) and the support cap (38).
8. Hand pump according to one of the above claims, characterized in that it is integrated in a filter system (10) for liquids, in particular in a filter head (12).
9. Filter system (10) for liquids, in particular fuel, in particular of a motor vehicle, with a hand pump (16) for pumping the liquids, according to one of the above claims.

Images