DE102021134629B4 - Pump head for a diaphragm pump - Google Patents

Abstract

Pump head (1) for a diaphragm pump (20), - wherein the pump head (1) comprises a connection part (21) and a diaphragm (3), and - wherein the diaphragm (3) forms a working space (4) with the connection part (21), - wherein the pump head (1) has a fixing element (2) with which an internal quick-release fastener (22) with a lifting element (16), in particular with a connecting rod (16), of the diaphragm pump (20) can be formed in the diaphragm pump (20), characterized in that - the diaphragm (3) and the connection part (21) are materially connected to one another at at least one contact point (23) by plastic welding, and - that the diaphragm is formed from a material which has a polymer base which has the polymer base of a contacting material.

Description

The invention relates to a pump head for a diaphragm pump, wherein the pump head comprises a connecting part and a diaphragm and wherein the diaphragm forms a working chamber with the connecting part. The working chamber can also be referred to as a pump chamber.

The invention further relates to two methods for producing such a pump head.

The invention further relates to a diaphragm pump comprising a motor driving a lifting element and a pump head as described above.

Such pump heads, diaphragm pumps and methods for producing a pump head are widely used in practice. For example, such diaphragm pumps can be used during operations on patients to pump out smoke from organs or other fluids from the patient. After an operation, it is currently necessary to sterilize the entire pump, which is complex and expensive.

EN 102 95 375 T1 describes a suction pump capable of pumping solids, liquids and gases. Attached to the bottom of a three-chamber vessel is a mounting base which is used to mount the vessel and its associated hoses onto the drive housing or a docking device connected to the drive housing. The mounting base is also used to attach or secure a diaphragm to the bottom of the three-chamber vessel.

DE 20 2017 004 425 U1 describes a pump head for diaphragm pumps comprising a valve receiving body with several inlet and outlet valves and several pump chambers, wherein the pump chambers are formed on the top side in the valve receiving body, a pump diaphragm which is arranged above the pump chambers of the valve receiving body and seals them leak-free, a swash plate, an eccentric disk which is arranged above the swash plate, and a frame with several preferably circular frame openings for receiving several tappets which are arranged on the underside of the swash plate, characterized in that the pump head is formed separately from a drive and is thus individually replaceable and forms a hermetically sealed unit.

EP 2 528 637 B1 describes a pump cassette comprising a pump body having a pump chamber, an inlet valve in fluid communication with the pump chamber, and an outlet valve in fluid communication with the pump chamber; a diaphragm coupled to the pump body such that the diaphragm is movable to change a volume in the pump chamber; and an identifier configured to store one or more characteristics of the pump cassette such that the identifier can be read by an automated reader to determine the one or more characteristics.

CH 711 436 A1 describes a replaceable pump cartridge for a diaphragm pump. This has a base body and a cover body. A pump diaphragm is arranged between the base body and the cover body. Assembly can be carried out by placing the pump diaphragm, the inlet valve flap and the outlet valve flap in the base body and then placing the cover body on top and connecting it to the base body, e.g. by laser welding or a snap connection.

WO 2019 / 113 033 A1 describes a diaphragm assembly having a flexible diaphragm and a puller. The diaphragm has a front side and an opposite rear side, and an upper opening formed through the diaphragm and a lower opening. The puller has a diaphragm end, a cam end, a puller body extending between the diaphragm end and the cam end along a puller longitudinal axis, and a first retaining bar extending laterally from the puller body with respect to the puller longitudinal axis. The puller body is disposed through the upper opening, with the diaphragm disposed between the diaphragm end and the first retaining projection, with the diaphragm end disposed at the front side and the first retaining projection disposed at the rear side.

US 2008 / 0 292 477 A1 describes a diaphragm pump for pumping shower wastewater, comprising a diaphragm housing, a diaphragm removably held in the diaphragm housing, an openable cover on the diaphragm housing for access to the diaphragm, an electric motor, a connecting element arranged in the diaphragm housing and movable by the electric motor, and a threadless twist and lock closure which releasably engages the diaphragm with the connecting element.

The invention is based on the object of creating a diaphragm pump which is suitable for clinical medical applications on patients, is particularly cost-effective to produce and easy to handle, and meets the strict requirements for sterility and cleanliness.

To solve this problem, the invention proposes the features of claim 1. In particular, in a pump head of the type described at the outset, the invention proposes that the pump head has a fixing element with which an internal quick-release fastener with a lifting element of the diaphragm pump can be formed in the diaphragm pump. The lifting element is preferably a connecting rod.

Such a fixing element allows the pump head to be coupled to and detached from the drive mechanism of the diaphragm pump quickly and with just a few simple steps.

A quick-release fastener can be characterized in that the pump head can be detached from the pump housing and attached to it in one or a few simple steps. The quick-release fastener can be designed as a bayonet fastener, for example. The fixing element then has at least one bayonet claw and/or at least one bayonet lug.

The quick-release fastener can be designed as a positive and/or non-positive connection. The quick-release fastener can also be designed as a snap-in connection, for example.

The solution according to the invention has the advantage that the pump head can be easily removed. This brings with it particular advantages in clinical use. In this way, only those areas of a pump that come into contact with the fluids from a patient are contaminated. These are therefore the connections and the working area of the pump. It is therefore sufficient to sterilize the pump head.

The simple exchangeability of the pump head made possible by the invention now allows the pump head to be easily removed. The pump head can now be sterilized or, preferably, it is completely replaced. Especially in medical applications, the use of a new, already sterilely packaged disposable pump head is particularly preferred. In particular, the simple exchangeability of the pump head means that it can only be intended for single use as a disposable product. For this purpose, the pump head is preferably made only from inexpensive parts. The pump drive can also be designed for a long service life.

In an advantageous embodiment, it can be provided that the fixing element is connected to the membrane in a form-fitting and/or material-fitting manner. For the form-fitting connection, the fixing element is preferably at least partially covered by the membrane. The form-fitting connection can be achieved, for example, by putting the membrane over the fixing element. For this purpose, the fixing element can be designed to be head-like, i.e. widening on the covering side. The creation of a material-fitting connection can be achieved, for example, by means of a two-component injection molding process. For this purpose, the material for the fixing element can first be injected into a tool, then the tool can be adjusted and the material of the membrane can be injected into the tool. Due to the high processing temperature, the two materials form a material-fitting connection, which significantly improves the hold of the fixing element. Preferably, both a form-fitting and a material-fitting connection are provided.

For smaller pump heads, it can be advantageous if the membrane and the fixing element are made in one piece. For this purpose, a corresponding tool mold can be produced and the combined membrane-fixing element part can then be manufactured by injection molding. If a thermoplastic elastomer is used for this combined part, it will be a soft material and/or a material that is softer than the material of the connecting part. In order to achieve the quick-release fastener, undercuts can be cut into the combined part, which can be removed by forced demolding. With low forces, which occur with a correspondingly small pump, the undercut will be sufficient to hold the membrane to the fixing counterpart during operation, so that the positive connection holds. The positive connection may not be able to withstand greater forces due to the soft material. However, this can also be useful because the internal quick-release fastener can then be detached from the lifting element by manually pulling the pump head out, which is even easier than, for example, releasing it with a rotating movement.

The previously mentioned designs of the connection of the membrane with the fixing element and the one-piece design have in common that during operation a movement of the fixing element moves the membrane and changes the working space due to the movement caused. When the pump head is used in a diaphragm pump, the fixing element is mechanically connected to the lifting element, in particular the connecting rod. During operation, the lifting element performs a linear movement, which is not perfect with an eccentric drive, since a tilting movement occurs without joint guides. The movement is preferably a lifting movement. During operation, the diaphragm therefore performs an oscillating movement, which periodically reduces and enlarges the working space. The pumping effect can be achieved in this way by means of valves arranged in the pump head. The pumping effect is achieved during operation by enlarging the working space, creating a negative pressure in it and therefore fluid flows into it. In a subsequent counter stroke, the fluid is compressed, creating excess pressure. The inlet valve closes and the outlet valve opens, so that the fluid is pumped out of the working chamber via the outlet.

It can be provided that the fixing element has a locking element. The locking element is preferably a bayonet claw or a bayonet lug. The aforementioned quick-release fastener is then a bayonet fastener.

It can be provided that the connection part comprises a connection element which has an inlet and an outlet, which are each fluidically connected to the working space, and that the connection part has an intermediate element which is arranged between the connection part and the membrane. The intermediate element preferably delimits the working space. A wall of the working space is therefore formed by a surface of the intermediate element. Furthermore, it is preferably provided that an inlet valve and an outlet valve are arranged between the connection element and the intermediate element.

The connection element is preferably designed as a connection plate. Likewise, the intermediate element is preferably designed as an intermediate plate. The connection plate and/or the intermediate plate and/or the membrane can in particular be layered on top of one another.

It can be provided that the inlet valve and the outlet valve are connected to each other in one piece.

The inlet valve and the outlet valve can be made of the same material. For example, the valves can be made of an elastomer, a thermoplastic elastomer and/or a silicone.

The inlet valve can be arranged in an inlet chamber and preferably only partially fills this at least on the downstream side. Accordingly, the outlet valve can be arranged in an outlet chamber and preferably only partially fill this at least on the downstream side. The two chambers are preferably formed between the connection element and the intermediate element.

In order to create a pump head that is as cost-effective as possible, it can be designed to be made entirely of plastic.

It can be provided that the connection part, in particular the connection element and/or the intermediate element, the valves, the membrane and/or the fixing element and/or the clamping device are made of plastic. The plastics used in each case can be the same or different for different parts. Preferably, however, the plastics of at least two of the parts of the pump head are different. Which plastics and plastic combinations can be particularly advantageous is explained in more detail elsewhere.

In order to create a stable and tight pump head, the invention provides that the membrane and the connecting part are materially connected to one another at at least one contact point.

According to the invention, the material-locking connection is created by plastic welding. A preferred welding method for plastics is the laser welding method. Such a plastic welding method is generally a preferred welding method within the scope of this invention. However, other plastic welding methods are also possible and can lead to very good results, such as a mirror welding method.

Preferably, the aforementioned material-locking connection is formed between the aforementioned intermediate element of the connecting part and the membrane.

Likewise, it can be provided that the connecting element and the intermediate element are connected to one another in a material-locking manner at at least one contact point. This material-locking connection is also preferably created by laser welding.

The material-locking connections have the advantage, among other things, that the pump head can be removed from the diaphragm pump as a one-piece assembly and can therefore be easily removed. can be replaced without having to replace several individual parts.

The connection element is preferably made of a thermoplastic. The thermoplastic is particularly preferably polypropylene. The connection element is particularly preferably transparent in a frequency range of a laser radiation. The connection element can therefore be passed through by the laser during laser welding.

It can be provided that the diaphragm has a spring which, when installed, protrudes into a notch in a pump housing of the diaphragm pump. The spring and notch are preferably designed to run all the way around. This allows a secure fit and positioning of the diaphragm. By pre-tensioning the spring when assembled, tolerances in the structure can be compensated.

In a further advantageous embodiment of the pump head, the pump head can have a clamping device with which the pump head can be clamped to a pump housing of the diaphragm pump. Preferably, an external quick-release fastener can be formed with the clamping device and the pump housing. The quick-release fastener is particularly preferably a bayonet fastener. Such pump head designs are particularly advantageous because they can be replaced quickly and easily in just a few steps thanks to the double quick-release fastener, one on the inside for fastening the pump head to the diaphragm drive and one on the outside for fastening the pump head to the pump housing of the diaphragm pump. To replace the pump head, a design is recommended in which the clamping device is first loosened and removed and then the pump head is removed from the lifting element. A new, preferably sterile, pump head can then be attached to the lifting element using the internal quick-release fastener and then attached to the pump housing using the external quick-release fastener and the clamping device.

Preferably, the clamping device can be releasably attached to the connecting part.

The quick release fastener is preferably a bayonet fastener, but can also be designed in another way, such as a snap fastener.

In a particularly advantageous embodiment of the pump head, it can be provided that the membrane and the connection part have materials at at least one contact point with the membrane, for example at the previously mentioned at least one contact point, which can be welded together by plastic welding, preferably by laser welding. The membrane and the connection part are then connected to one another in a materially bonded and germ-tight manner. Preferably, the membrane and the previously mentioned intermediate element of the connection part have materials at the at least one contact point with the membrane which can be welded together by plastic welding, preferably laser welding.

It can be provided that a material of the membrane, for example the material mentioned above, is a thermoplastic elastomer. If the membrane is manufactured together with the fixing element in a 2K injection molding process, the material of the fixing element preferably contains a material that is harder than the material of the membrane. Polypropylene, for example, can be used as a hard component. Normally and in the prior art, the membrane consists of a rubber. Thermoplastic elastomers appear disadvantageous at first glance because they are less mechanically resilient than pure elastomers such as rubber. A pure elastomer in itself seems to optimally fulfill the desired properties of a membrane. The applicant has recognized here for the first time that thermoplastic elastomers as a membrane material are particularly advantageous for short-term applications, since this material makes it possible to create stable and replaceable pump heads at particularly low cost. For example, this material is ideally suited to plastic welding because it can be plastically deformed when exposed to heat.

The connection element, the intermediate element and/or the fixing element preferably have the same base material. The base material is preferably a thermoplastic. The same material base has the advantage that the melting temperatures and the chemical properties will be identical or similar, so that an optimal result can be achieved when welding plastic. The entire connection part can contain the same plastic base.

The membrane is preferably made of a material that has a similar melting point to a material of an adjacent part, such as a material of the intermediate element. By similar is meant that plastic welding is possible and leads to a material-tight connection. For example, the melting temperatures can differ by a maximum of 10°C, preferably by a maximum of 5°C.

Furthermore, the membrane is preferably made of a material that has a polymer base that is the same as the polymer base of a contacting material, such as in particular a material of the intermediate element. For example, the intermediate element can be made of the thermoplastic polyolefin and the membrane can be made of a thermoplastic elastomer based on olefin, such as in particular TPE-O or TPE-V. Materials that are similar in this way can form particularly stable connections when plastic is welded.

In a further advantageous embodiment of the pump head, it can be provided that a material of the connection part, such as the previously mentioned material of the connection part, is a thermoplastic at at least one contact point with the membrane, for example at the previously mentioned contact point. The thermoplastic is preferably polypropylene. A material of the intermediate element at the contact point with the membrane is preferably a thermoplastic. Particularly preferably, the membrane is made of a thermoplastic elastomer as mentioned above and the connection part or the intermediate element is made of a thermoplastic. This material combination is well suited to plastic welding and results in a stable, tight and cost-effective pump head.

In an advantageous embodiment, it can be provided that the membrane or the connecting part is transparent to light in a frequency range at at least one contact point with the membrane, for example at the previously mentioned contact point. Preferably, the previously mentioned intermediate element of the connecting part or the membrane is permeable to light in the frequency range. The other part is then preferably laser-absorbent at the contact points. For laser welding, either the membrane or the connecting part or the intermediate element is preferably transparent and the other part is laser-absorbent.

To create a laser-absorbing part, an inherently transparent material can be colored, for example by adding masterbatch.

In an advantageous embodiment, it can be provided that the connection element and the intermediate element have materials at at least one contact point, for example at the at least one contact point mentioned above, which can be welded to one another by plastic welding, preferably laser welding. Advantageous materials have already been mentioned above.

The connecting element and/or the intermediate element and/or the membrane are preferably manufactured by injection molding. The valves are preferably manufactured as stamped parts, but can also be manufactured by injection molding.

The connecting element and the intermediate element are preferably made of a thermoplastic polypropylene. The connecting element is preferably transparent to laser light used for laser welding, while the intermediate element absorbs the laser light.

A fluid can be a gas or a liquid.

The pump head is preferably designed as a pump head for a gas or liquid pump. The pump head can also be designed for a diaphragm pump designed for pumping a gas-liquid mixture.

To achieve the above object, the features of the independent claim 13 are provided according to the invention, which is directed to a diaphragm pump. The counter-fixing element preferably has a bayonet claw and/or a bayonet lug.

The lifting element can be mechanically connected to a motor shaft of the motor via an eccentric. The lifting element can perform an oscillating lifting movement.

In an advantageous embodiment of the diaphragm pump, it can be provided that the pump housing has a closure element which forms an external quick-release fastener, for example the previously mentioned external quick-release fastener, with a clamping device of the pump head. The closure element preferably has a bayonet claw and/or a bayonet lug.

If the internal quick-release fastener is also designed as a bayonet lock, the pump head can be removed and reattached in two steps. To remove, first turn the clamping device and then unscrew the remaining part of the pump head from the lifting element. To reattach, this is done in the opposite order.

To achieve the above-mentioned object, the features of the independent claim 15 directed to a method for producing a pump head are provided according to the invention. In particular, to achieve the above-mentioned object, it is proposed according to the invention in a method for producing a pump head that the pump head is produced according to the invention, in particular as described above and/or according to a of claims 1 to 12 directed to a pump head, and that the membrane is permanently connected to the connection part and/or sealingly connected to the working chamber by laser welding. Preferably, the membrane is permanently connected to the intermediate element of the connection part and/or sealingly connected to the working chamber by plastic welding.

To achieve the stated object, the features of the further independent claim 16 directed to a further method for producing a pump head are provided according to the invention. In particular, to achieve the stated object, the invention proposes in a method for producing a pump head that the pump head is designed according to the invention, in particular as described above and/or according to one of the claims 1 to 12 directed to a pump head, and that the connection part comprises a connection element and an intermediate element and that the connection element is permanently connected to the intermediate element by plastic welding and/or is sealingly connected to valve chambers formed between the connection element and the intermediate element. The valve chambers are preferably the inlet and outlet chambers already mentioned above.

Of the processes described above, the preferred plastic welding method is laser welding.

The invention will now be described in more detail using a few exemplary embodiments, but is not limited to these few exemplary embodiments. Further variants of the invention and exemplary embodiments arise by combining the features of individual or multiple claims with one another and/or with individual or multiple features of the exemplary embodiments and/or the previously described variants of devices and methods according to the invention.

• 1 eine Membranpumpe mit einem auswechselbaren Pumpenkopf gemäß 2,
• 2 einen erfindungsgemäßen Pumpenkopf,
• 3 den in 2 gezeigten Pumpenkopf, der an einer Pumpe befestigt ist.

It shows:

• 1 a diaphragm pump with a replaceable pump head according to 2 ,
• 2 a pump head according to the invention,
• 3 the in 2 shown pump head attached to a pump.

In the following description of various embodiments of the invention, elements which correspond in their function are given the same reference numbers even if they have a different design or shape.

1 shows an embodiment of a diaphragm pump 20 designed according to the invention. The diaphragm pump 20 has a motor unit 29 with a motor 30 and an electrical connection 31 for supplying the motor 30 with electricity. The motor unit 29 is connected to a gear unit 32, which converts the rotational movement generated by the motor 30 via an eccentric arranged in the pump housing 17 into an oscillating linear stroke movement of a lifting element 16 designed as a connecting rod. A part of the lifting element 16 is in 3 shown.

In alternative embodiments, the lifting element 16 can also be moved by another drive with or without a gear, such as by a linear drive.

An easily replaceable pump head 1 is screwed onto the pump housing 17 of the gear unit 32. This is in 2 and 3 shown in more detail. The pump head 1 and its connection to the rest of the diaphragm pump 20 is designed in such a way that it can be replaced with simple hand movements by means of rotating movements. Some useful applications have already been described above.

The pump head 1 comprises a fixing element 2, a membrane 3, an intermediate element 5 designed as an intermediate plate, a connection element 6 designed as a connection plate, an inlet valve 11 and an outlet valve 12.

A working space 4 is defined by the membrane 3 and the intermediate element 5.

The volume of the working space 4 is variable. In pumping mode, the fixing element 2 is moved up and down. The membrane 3 pulled onto the fixing element 2 then also oscillates in an up and down movement, so that the working space 4 alternately shrinks and enlarges.

The fixing element 2 is at least partially covered by the membrane 3. The membrane 3 can be put over the fixing element 2. The membrane 3 can also be connected to the fixing element 2 in a material-locking manner. The material-locking connection can be achieved, as described above, for example by means of a two-component injection molding process. In the installed state, the fixing element 2 is connected to the lifting element 16 by means of a quick connection. This quick connection is referred to as an internal quick connection because it is formed inside the membrane pump 20. In the embodiment shown, the quick connection is designed as a bayonet lock, in which the fixing element 2 has several bayonet claws 27 and the Counter-fixing element 19 may have a plurality of bayonet lugs 28 of corresponding number.

The connecting part 21 comprises the connecting element 6 and the intermediate element 5.

The connection element 6 has an inlet 7 and an outlet 8. The inlet 7 is connected to the working chamber 4 via an inlet channel 9. The outlet 8 is connected to the working chamber 4 via an outlet channel 10.

An inlet chamber 13 is formed in the inlet channel 9 and houses an inlet valve 11. The inlet chamber 13 has a diameter that narrows in the direction of flow. The inlet valve 11 is arranged in the area with a wider diameter.

An outlet chamber 14 is formed in the outlet channel 10 and houses an outlet valve 12. The outlet chamber 14 has a diameter that narrows in the direction of flow. The outlet valve 12, like the inlet valve, is arranged in the region in which the diameter of the outlet chamber 14 is not narrowed.

The area of the diaphragm pump 20 to be sterilized comprises in particular the inlet channel 9, the outlet channel 10 and the working chamber 4.

The inlet valve 11 and the outlet valve 12 are made of the same material. This can be an elastomer and/or a silicone. The inlet valve 11 and the outlet valve 12 can be made in one piece or in multiple parts.

The membrane 3 further comprises a preferably circumferential spring 15, which projects into a circumferential notch 34 of the pump housing 17.

The membrane 3 is materially connected to the intermediate element 5 at several contact points 23. The material connection is achieved by plastic welding, in the case described here by laser welding. For this purpose, the membrane 3 is made of a transparent thermoplastic elastomer and the intermediate element 5 is made of a laser-absorbing thermoplastic such as polypropylene.

The intermediate element 5 is materially connected to the connecting element 6 at several contact points 33. The material connection was also achieved by plastic welding, in this case by laser welding. For this purpose, the connecting element 6 is made of a thermoplastic that is transparent to the laser, such as transparent polypropylene.

The inlet channel 9, the working chamber 4 and the outlet channel 10 form a tight and sterile arrangement, which is advantageous for tasks in the surgical-medical field.

The pump head 1 can be packaged sterile, preferably in a blister.

The pump head 1 is connected to the lifting element 16, which is designed as a connecting rod, via the internal quick-release fastener 22, which is designed as a bayonet fastener. The pump head 1 is also connected to the pump housing 17 via the external bayonet fastener by means of the clamping device 18. For this purpose, the fastener 26 formed on the pump housing 17 has bayonet claws 27, into which bayonet claws 28 formed on the clamping device 18 can engage.

The pump head 1 is thus designed as a two-part overall arrangement, with a first part of the pump head 1 being formed by the clamping device 18 and the rest of the pump head 1 forming the other part. As previously described, the pump head 1 can be removed from the pump housing 17 and screwed onto it by means of a two-stage rotary movement of preferably 90° each.

For this purpose, the clamping device 18 is placed over the pump head 1 and then clamped to the pump housing 17 with a rotational movement. This quick-release fastener can be referred to as an external or external quick-release fastener 24, since it is located on the outside or outside of the diaphragm pump.

The invention relates to a pump head 1 for a diaphragm pump 20, wherein the pump head 1 comprises a connection part 21 and a diaphragm 3 and wherein the diaphragm 3 forms a working chamber 4 with the connection part 21. The pump head 1 is characterized in that it has a fixing element 2 with which an internal quick-release fastener 22 with a lifting element 16, in particular a connecting rod 16, of the diaphragm pump 20 can be formed in the diaphragm pump 20.

List of reference symbols

1

Pump head

2

Fixing element

3

membrane

4

working space

5

Intermediate element

6

Connection element

7

inlet

8th

Outlet

9

Inlet channel

10

Exhaust channel

11

Inlet valve

12

outlet valve

13

Inlet chamber

14

Outlet chamber

15

Feather

16

Lifting element

17

Pump housing

18

Clamping device

19

Counter-fixing element

20

Diaphragm pump

21

Connection part

22

internal quick release fastener

23

Contact point between 3 and 5

24

external quick release

26

Locking element

27

Bayonet claw

28

Bayonet lug

29

Motor unit

30

engine

31

electrical connection

32

Gear unit

33

Contact point between 5 and 6

34

score

Claims (16)

Pump head (1) for a diaphragm pump (20), - wherein the pump head (1) comprises a connection part (21) and a diaphragm (3), and - wherein the diaphragm (3) forms a working space (4) with the connection part (21), - wherein the pump head (1) has a fixing element (2) with which an internal quick-release fastener (22) with a lifting element (16), in particular with a connecting rod (16), of the diaphragm pump (20) can be formed in the diaphragm pump (20), characterized in that - the diaphragm (3) and the connection part (21) are materially connected to one another at at least one contact point (23) by plastic welding, and - that the diaphragm is formed from a material which has a polymer base which has the polymer base of a contacting material. Pump head (1) according to the preceding claim, characterized in that the fixing element (2) is connected to the membrane (3) in a form-fitting and/or material-fitting or integral manner and/or that the fixing element (2) has a locking element (27, 28), in particular a bayonet claw (27) and/or a bayonet lug (28). Pump head (1) according to one of the preceding claims, characterized in that the connecting part (21) comprises a connecting element (6) which has an inlet (7) and an outlet (8), which are each fluidically connected to the working chamber (4), and in that the connecting part (21) has an intermediate element (5) which is arranged between the connecting part (21) and the membrane (3), in particular wherein the intermediate element (5) delimits the working chamber (4) and/or wherein an inlet valve (11) and an outlet valve (12) are arranged between the connecting element (6) and the intermediate element (5). Pump head (1) according to one of the preceding claims, characterized in that the pump head (1) is made entirely of plastic. Pump head (1) according to one of the Claims 3 or 4 , characterized in that the membrane (3) and the intermediate element (5) are materially connected to one another at at least one contact point (23), in particular by plastic welding. Pump head (1) according to one of the Claims 3 until 5 , characterized in that the connecting element (6) and the intermediate element (5) are materially connected to one another at at least one contact point (33), in particular by plastic welding. Pump head (1) according to one of the preceding claims, characterized in that the pump head (1) has a clamping device (18) with which the pump head (1) can be clamped to a pump housing (17) of the diaphragm pump (20), in particular wherein an external quick-release fastener (24), preferably a bayonet fastener, can be formed with the clamping device (18) and the pump housing (17). Pump head (1) according to one of the preceding claims, characterized in that the membrane (3) and the connecting part (21) have materials at at least one or at the at least one contact point (23) to the membrane (3). which can be welded together by plastic welding, in particular by laser welding. Pump head (1) according to one of the preceding claims, characterized in that one or the material of the membrane (3) is a thermoplastic elastomer, in particular wherein the material of the membrane (3) additionally contains a polypropylene. Pump head (1) according to one of the preceding claims, characterized in that one or the material of the connection part (21), in particular one or the material of the intermediate element (5), at at least one or at the at least one contact point (23) to the membrane (3) is a thermoplastic, in particular polypropylene. Pump head (1) according to one of the preceding claims, characterized in that the membrane (3) or the connection part (21) is transparent to light in a frequency range at at least one or at the at least one contact point (23) to the membrane (3). Pump head (1) according to one of the Claims 3 until 11 , characterized in that the connection element (6) and the intermediate element (5) have materials at at least one or the at least one contact point (33) which can be welded to one another by plastic welding, in particular by laser welding. Diaphragm pump (20) comprising - a pump housing (17), - a motor (30) which drives a lifting element (16), - a pump head (1) and - a clamping device (18), - which can be detached from the pump head (1) and - with which the pump head (1) can be clamped to the pump housing (17), - wherein the pump head (1) comprises a connecting part (21) and a diaphragm (3) and wherein the diaphragm (3) forms a working space (4) with the connecting part (21), - wherein the pump head (1) has a fixing element (2) with which an internal quick-release fastener (22) with a lifting element (16) of the diaphragm pump (20) can be formed in the diaphragm pump (20), - wherein the lifting element (16) has a counter-fixing element (19) which connects the internal quick-release fastener (22) with the fixing element (2) in the diaphragm pump (20). trained. Diaphragm pump (20) according to the preceding claim, characterized in that an external quick-release fastener (24), preferably a bayonet fastener, is formed with the clamping device (18) and the pump housing (17). Method for producing a pump head (1), - wherein the pump head (1) is manufactured according to one of the Claims 1 until 12 is designed, characterized in that - the membrane (3) is permanently connected to the connecting part (21) and/or the working space (4) in a sealing manner by plastic welding, in particular by laser welding. Method for producing a pump head (1), - wherein the pump head (1) is manufactured according to one of the Claims 1 until 12 is designed, characterized in that - the connecting part (21) comprises a connecting element (6) and an intermediate element (5) and - that the connecting element (6) is connected by plastic welding, in particular by laser welding, - in a non-detachable manner to the intermediate element (5) and/or - sealingly connected to valve chambers (13, 14) formed between the connecting element (6) and the intermediate element (5).