Membrane fastening method on driving device of metering pump

Abstract

The present invention relates to a metering pump comprising: (i) a diaphragm return device comprising a tie rod; and (ii) a diaphragm kit comprising a mechanically driven elastic diaphragm having a flexible region between a clamping surface at the edge of the diaphragm for sealing the delivery chamber and a diaphragm core for transmitting force, generating pressure and connecting to the tie rod, characterized in that the diaphragm has a flexible region between the clamping surface and the diaphragm core; the diaphragm set and the pull rod are connected by means of a hook-type connection, a plug-type connection, or a clamping connection.

Description

Technical Field

[0001] The invention relates to a fastening method of a diaphragm of a metering pump on a driving device of the metering pump. Background Art

[0002] In the prior art, various types of pumps are known by different names, which are named according to their technical structure or their function, such as piston pump, metering pump, diaphragm pump, etc.

[0003] For example, in reciprocating piston pumps, a mechanically driven piston is used which runs in a cylinder. Here, the piston is combined with an inlet and an outlet which are each closed by a valve. In the first stroke, i.e. during suction, the piston moves in such a way that the volume in the cylinder increases and thus the delivery fluid flows into the cylinder when the inlet valve is opened. Subsequently, the inlet valve is closed and the outlet valve is opened, and the piston moves in the cylinder in such a way that the volume in the cylinder decreases again and thus the delivery fluid is discharged from the outlet valve.

[0004] In contrast, a hydraulically driven diaphragm pump has a delivery chamber with a suction connection and a pressure connection, and a hydraulic chamber which is separated from the delivery chamber by a diaphragm. To convey the medium, the diaphragm is moved back and forth in an oscillating manner between a first position and a second position in such a way that the hydraulic chamber is filled with a hydraulic fluid which is subjected to an oscillating pressure by the piston. The two positions of the diaphragm are generally referred to as the compression stroke position and the suction stroke position.

[0005] The pressure interface is usually connected to the delivery chamber via a pressure valve designed as a check valve, while the suction interface is connected to the delivery chamber via a suction valve also designed as a check valve. When the diaphragm moves from the first position to the second fixed position, that is, in the so-called suction stroke, the volume of the delivery chamber increases, thereby causing the pressure in the delivery chamber to drop. Once the pressure in the delivery chamber is lower than the pressure in the suction line connected to the suction interface, the suction valve opens and the medium to be delivered is sucked into the delivery chamber via the suction interface. Once the diaphragm moves from the second position toward the first position again (the so-called compression stroke), the volume in the delivery chamber decreases and the pressure in the delivery chamber increases. The suction valve is closed to prevent the medium to be delivered from flowing back into the suction line. Once the pressure in the delivery chamber exceeds the pressure in the pressure line connected to the pressure interface, the pressure valve is opened so that the delivery medium in the delivery chamber can be pressed into the pressure line.

[0006] The application of an oscillating pressure to the hydraulic fluid thus results in an oscillating movement of the diaphragm and, associated therewith, in an oscillating pumping process of the conveying fluid from the suction line into the pressure line.

[0007] Hydraulically driven diaphragm pumps are preferably used for conveying conveying fluids under high pressure, since the hydraulic fluid results in a uniform loading of the diaphragm and thus a longer service life of the diaphragm.

[0008] The diaphragm can have a diaphragm return device in the form of a tie rod which assists in the direction of the suction stroke position.

[0009] In the case of hydraulically driven diaphragm pumps, the term "pull rod" has been used for the diaphragm return device. In the case of mechanically driven diaphragm pumps, the term "push rod" is often used for the corresponding component, because the diaphragm is pushed during the compression stroke.

[0010] The diaphragm itself generally comprises multiple layers, usually two layers of polytetrafluoroethylene (PTFE) surrounding a fabric layer in a sandwich structure.

[0011] The diaphragm further comprises a diaphragm core having a receptacle for the tie rod. The diaphragm core is generally made of metal, but may also be made of a suitable plastic.

[0012] Usually, together with the diaphragm retaining disk and the clamping screws which secure the above-mentioned layers and are mounted on the end of the tie rod, a so-called diaphragm kit is formed.

[0013] In order to connect the diaphragm set to the tie rod (or push rod), various solutions are described in the prior art. Thus, for example, it is known that the diaphragm set has a threaded projection, which is screwed into the tie rod until it encounters a fixed stop. In this case, a sliding key prevents the tie rod from rotating together.

[0014] A disadvantage of this solution is that the threads may break in the event of improper installation. A further disadvantage is that special tools must be used, which can damage the diaphragm itself during assembly. A further disadvantage is that additional components are required to prevent the tie rod from rotating together. Furthermore, the threaded counterpart (shaft / core) made of metal can corrode in aggressive pumping environments and is then difficult to release.

[0015] The reverse variant of the threaded connection is also known from the prior art. Here, the diaphragm kit does not have a threaded projection, but the threaded projection is provided by a tie rod. However, this known embodiment also does not overcome the above-mentioned disadvantages of the threaded connection formed by the diaphragm kit. Here, too, a special tool must be used to screw the diaphragm kit onto the threaded projection.

[0016] Documents which disclose fastening a diaphragm assembly to a tie rod by means of a screw connection are, for example, DE 102019 109283 A1, DE 3931516 C2, DE 10 2005 039772 A1, DE 10 2011105000 A1 and WO 2011 / 101118 A1.

[0017] Furthermore, it is known from the prior art to fasten the metering diaphragm to the tie rod by means of a coupling device (DE 1653586 C3). The additional coupling device makes the pump more expensive.

[0018] Another option is to connect the metering diaphragm to the tie rod by means of a ball connection, a hook connection or a T-slot connection which is integrated into the tie rod and the diaphragm core. However, due to the high precision requirements, this type of connection is very expensive. In addition, the diaphragm must be mounted laterally. However, in many delivery units, even a lateral diaphragm mounting is not possible due to the small cutout in the drive housing.

[0019] Alternatively, it is also known from the prior art that the diaphragm layer is held directly by the diaphragm disk and the tie rods, without the diaphragm kit comprising a clamping screw. In this case, the tie rods also assume the function of the clamping screws. This solution requires that when the diaphragm is replaced, either the tie rods must be replaced at the same time, or the diaphragm kit must be professionally clamped, glued and provided with a release agent on site.

[0020] In addition, plug-in connections, rotational connections or bayonet connections between diaphragms and tie rods are also known from the prior art (for example, from DE 10 2004 035651 A1). Here, it is difficult to achieve an angular positioning of the diaphragm. In addition, the precision requirements for the components are also very high.

[0021] In addition, clamping connection methods are widely used in the technical field. Documents DE 20 2015 103406 U1 and EP3660380 A1 disclose application examples. The disadvantages of these connection methods in the prior art are their complexity, high space requirements and complex assembly. Summary of the invention

[0022] Therefore, the purpose of the present invention is to overcome the shortcomings of the prior art and in particular to provide a reliable connection method for a diaphragm kit and a pull rod, which connection method is suitable for situations where no screwing is required, does not require complicated assembly, can achieve easy angular positioning of the diaphragm and, in the case of this connection method, minimizes the risk of damage to the diaphragm during assembly.

[0023] This object is achieved by a diaphragm pump having a diaphragm kit and a diaphragm return device including a tie rod, wherein the connection between the diaphragm kit and the tie rod is achieved by means of (i) a hook connection device, or (ii) a plug connection device, or (iii) a special clamping connection device.

[0024] In this case, the diaphragm is connected to the tie rod by axial or oblique lateral introduction and rotation.

[0025] In a first embodiment, the diaphragm kit and the pull rod are connected by a hook-type coupling device.

[0026] The subject matter of the invention is therefore, on the one hand, a metering pump comprising a mechanically driven elastic diaphragm having a flexible region between a clamping surface at the edge of the diaphragm for sealing a delivery chamber and a diaphragm core for transmitting force, generating pressure and for connecting to a tie rod, wherein

[0027] The diaphragm core is provided with a preferably cylindrical sleeve in the direction of the tie rod, which sleeve preferably carries two plates arranged opposite to one another at the end.

[0028] The tie rod is provided with an axial bore at the end for receiving the socket plate, and

[0029] The tie rod is equipped with a coupling sleeve which has a radial transverse slot-like opening, wherein the opening serves to allow the socket plate to be inserted through and subsequently rotated.

[0030] By rotating the membrane, the plates of the screw-in socket are locked relative to the connecting sleeve and are connected together in a non-detachable manner.

[0031] Hook-type couplings usually have an axial play of at most 0.05 mm in the connection. By means of the inclined (1° to 3°) plate surfaces, the connection can be clamped and thus free of play. This free of play is necessary for a perfect diaphragm function and to avoid losses in the stroke length of the pump. At the same time, a free of play connection ensures that the two surfaces cannot move relative to one another and therefore cannot wear out.

[0032] The non-detachable fastening of the coupling sleeve on the tie rod can be established, for example, by crimping, clinching (reshaping), pressing, pinning, screwing, welding or gluing, preferably by crimping or screwing. During operation of the pump, the fastening of the coupling sleeve on the tie rod can loosen. Therefore, the tie rod and the coupling sleeve are particularly preferably not manufactured as separate parts and then connected to each other, but are either produced in one piece from metal by machining or in one piece from a suitable plastic by injection molding.

[0033] In one embodiment, the coupling sleeve and the tie rod are thus made as a whole (embodiment 1a). Preferably, the production is carried out here from metal, preferably from quenched and tempered steel (such as material number 1.7225), case-hardened steel (such as material number 1.7147) or stainless steel (such as material numbers 1.4462, 1.4122 or 1.4305) by machining. However, it is particularly preferred that the one-piece combination of coupling sleeve and tie rod is made of plastic or a composite structure consisting of steel and plastic. In this composite structure, the tie rod is preferably made of metal, preferably one of the above-mentioned steel materials, and the coupling sleeve is made of plastic. The plastic typically used here is polyphenylene sulfide (PPS) reinforced with glass fibers, wherein the glass fiber content typically accounts for about 40% of the total mass of the plastic. The processing of the plastic is preferably carried out by injection molding. However, other processing technologies can also be used.

[0034] In another embodiment, the coupling sleeve is connected to the pull rod by crimping (embodiment 1b).

[0035] In a further embodiment, the coupling sleeve is screwed directly to the tie rod (embodiment 1c).

[0036] In a further embodiment, the coupling sleeve is fastened to the tie rod by means of screws (embodiment 1d).

[0037] The force transmission to the diaphragm core takes place in a positively locking manner during the compression stroke via the tie rod and the end face of the coupling sleeve, and during the suction stroke via the surface of the connecting plate facing the tie rod and the shoulder of the coupling sleeve.

[0038] In the case of a diaphragm coupled to a sensor region (plate) for rupture signaling (e.g. diaphragms according to EP 2 180 185 A2 or EP 1 384 891 A1), an exact correlation of the angular position of the diaphragm plate relative to the socket plate can be ensured very easily during diaphragm production. During pump assembly, the diaphragm plate is positioned precisely and without problems below the sensor. Compared to a directly screwed diaphragm, the hooked-in diaphragm core can compensate for larger radial angular errors of the diaphragm plate and thus facilitate the angular positioning of the diaphragm.

[0039] Since the diaphragm connection is achieved by axial plugging and rotation, the diaphragm no longer needs to be assembled sideways as in the conventional hook-type connection. Therefore, the invention can also be used for small conveying units and small diaphragm retaining plates. The diaphragm retaining plate is an adapter plate mounted on the drive device (pull rod) so that diaphragms of different sizes can be assembled.

[0040] In a further embodiment, the diaphragm kit and the tie rod are connected via a plug-in connection.

[0041] A further subject of the invention is therefore a metering pump comprising a mechanically driven elastic diaphragm having a flexible region between a clamping surface at the edge of the diaphragm for sealing the delivery chamber and a diaphragm core for transmitting force, generating pressure and for connecting to a tie rod, wherein

[0042] The diaphragm core is provided with a preferably cylindrical coupling means in the direction of the tie rod, wherein the coupling means has a groove.

[0043] The tie rod is provided with a first (axial) opening at the end side for accommodating the coupling mechanism, and

[0044] The tie rod has a second (radial) opening which is used to secure the coupling mechanism.

[0045] The force transmission to the diaphragm core is achieved in a positively locking manner during the compression stroke via the end face of the tie rod and during the suction stroke via the laterally hooked-in face of the coupling. The hooked-in diaphragm core can be twisted radially and thus enables an angular positioning of the diaphragm.

[0046] "Old-style" diaphragms provided with threaded holes can also be equipped with this coupling mechanism, making them also suitable for the coupling technique according to the invention.

[0047] The coupling mechanism is preferably connected with the diaphragm core by a screwed mode. However, the diaphragm core and the coupling mechanism can also be made in one piece.

[0048] When removing the diaphragm, the fastening of the coupling mechanism is released. The coupling mechanism and the diaphragm core can then be pulled out.

[0049] In a preferred embodiment (embodiment 2a), the coupling mechanism is fixed by means of a displaceable component arranged in the pull rod, which is "locked" into a groove of the coupling mechanism by the pressure of a compression spring. The force of the compression spring causes the displaceable component to always move upward. After the component is engaged, the coupling mechanism is locked. Then, by turning the diaphragm, a sensor area (plate) that may be present on the diaphragm for emitting a rupture signal is aligned. Disassembly is carried out in the reverse order: the displaceable component is displaced downward by means of a pin that is inserted from the outside by the installer through a hole in the diaphragm retaining plate (or in the drive housing); so that the coupling mechanism is released and can be pulled out.

[0050] In a further preferred embodiment (Embodiment 2b), the fixation of the coupling mechanism is achieved by means of a clamp-type coupling device consisting of two spring-clamped clamp halves. The clamp-type coupling device is assembled on two parallel transverse grooves of the pull rod. Then, the diaphragm is rotated to align a possible sensor area (lamella) for emitting a break signal on the diaphragm. For disassembly, a flat-head screwdriver is inserted into the slot of the clamp-type coupling device and the flat-head screwdriver is rotated by approximately 90° to open the clamp-type coupling device. Then, the diaphragm kit is pulled out of the pull rod. The clamp-type coupling device remains on the pull rod.

[0051] In a further preferred embodiment (Embodiment 2c-1), a spring-loaded sphere, for example an elastomeric compression member conforming to a standard, is introduced, preferably screwed, into a radial transverse hole of the pull rod. The coupling mechanism has a laterally extending groove with a variable depth. The coupling mechanism and the pull rod are connected by means of an interlocking plug and subsequent rotation in opposite directions. During rotation, the sphere sinks into a recess until it is snapped into its final position and the coupling mechanism is fixed. For disassembly, the coupling mechanism and the pull rod are rotated in opposite directions, where the sphere is pressed into its compression member (spring) and the fixation is released.

[0052] In an alternative preferred embodiment (Embodiment 2c-2), the compression member (spring) is not introduced into the pull rod but into the coupling mechanism, and the pull rod, instead of the coupling mechanism, has a wide transverse groove. The mode of operation in this embodiment corresponds to the mode of operation of Embodiment 2c-1.

[0053] In a further preferred embodiment (Embodiment 2d), flat-head bolts (threaded pins conforming to DIN 913 standard) are screwed into one or more radial transverse holes of the pull rod respectively. The coupling mechanism has a radially surrounding groove for receiving the bolt tips. For assembly, the coupling mechanism is inserted into the push rod until it abuts against a stop, and the diaphragm is rotated to align a possible sensor area (lamella) for emitting a break signal on the diaphragm. Then, for example, with an Allen key, one or more flat-head bolts are tightened, where one or more tips of the one or more screws fix the diaphragm core to the pull rod without play. Disassembly is achieved by removing the flat-head bolts.

[0054] The play-free nature of the connection given by this Embodiment 2d is beneficial for the proper functioning of the diaphragm and for avoiding losses in the stroke length of the pump. The play-free connection also ensures that the clamped surfaces do not move relative to each other and thus no wear occurs.

[0055] In a further embodiment, the diaphragm kit and the pull rod are connected by a special clamping connection device.

[0056] Therefore, another subject matter of the present invention is a metering pump, which comprises a mechanically driven elastic diaphragm, which has a flexible area between a clamping surface at the edge of the diaphragm for sealing the delivery chamber and a diaphragm core for transmitting force, generating pressure and for connecting to a tie rod, wherein the diaphragm core is provided with a screwable clamping sleeve in the direction of the tie rod, and the tie rod is provided with a clamping connection device, which has a first clamping hub and an optional second clamping hub, wherein the first clamping hub is machined into the tie rod itself, and the optional second clamping hub forms a separate component according to the embodiment, which is preferably fastened by screwing.

[0057] The clamping connection is preferably designed in accordance with DIN 32676 (so-called Tri-Clamp clamping connection), which makes the connection less complex and more cost-effective.

[0058] The force transmission to the diaphragm is achieved without play; in the compression stroke, this is achieved via the end face of the tie rod in a form-fitting manner, and in the suction stroke, this is achieved via a clamping connection. The hooked-in diaphragm core can be twisted radially before it is clamped, thus enabling an angular positioning of the diaphragm.

[0059] The clamping socket is either produced as an integral component with the diaphragm core or it can be introduced, preferably screwed, into an existing diaphragm as an “adapter bolt” with a socket.

[0060] The clamping connection has a clamping angle of preferably about 20° (according to DIN 32676). Thus, although the diaphragm must be introduced from the side, it is only introduced slightly tilted compared to conventional hook connections. The clamping connection according to the invention can therefore also be used for small diaphragm retaining plates.

[0061] In a preferred embodiment (embodiment 3a), the clamping connection has a second radially displaceable clamping hub. For diaphragm assembly, the diaphragm core provided with the clamping sleeve is introduced into the clamping groove of the tie rod, the diaphragm is aligned and then the second clamping hub is moved in the groove until it hits a stop and is fixed with a screw (clamping screw). For disassembly, the clamping screw is loosened, whereby the clamping connection is uncoupled and the diaphragm can be removed.

[0062] In a further preferred embodiment (embodiment 3b), the clamping connection has an axially displaceable coupling sleeve which is displaced in the direction of the diaphragm core so that the clamping sleeve is clamped in a clamping groove formed in the tie rod. In addition, a spring-loaded ball, for example a ball conforming to Standard elastic pressure piece. A corresponding recess for accommodating the ball is present in the coupling sleeve. For diaphragm assembly, the diaphragm core with the clamping sleeve is introduced into the clamping groove of the tie rod, the diaphragm is aligned and the coupling sleeve is then displaced until the ball engages in the recess and thus secures the connection. For disassembly, the coupling sleeve is pushed back, whereby the clamping connection is uncoupled and the diaphragm can be removed. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] Further features and advantages of the invention emerge from the following exemplary embodiments, in which the invention is explained by way of example with the aid of schematic drawings without the invention being restricted thereby.

[0064] In the attached picture:

[0065] Figure 1a-1 to Figure 1a-3 : A perspective view showing an embodiment 1a of a metering pump according to the present invention;

[0066] Figure 1b , Figure 1b-A and Figure 1b-B : A perspective view showing an embodiment 1b of a metering pump according to the present invention;

[0067] Figure 1c : A perspective view showing an embodiment 1c of a metering pump according to the present invention;

[0068] Figure 1d : A perspective view showing an embodiment 1d of a metering pump according to the present invention;

[0069] Figure 1e : A perspective view showing a diaphragm according to one of embodiments 1a to 1d;

[0070] Figure 2a-1 to Figure 2a-6 : A perspective view showing an embodiment 2a of a metering pump according to the present invention;

[0071] Figure 2b and Figure 2b-1 : A perspective view showing an embodiment 2b of a metering pump according to the present invention;

[0072] Figure 2c-1 : A perspective view showing an embodiment 2c-1 of a metering pump according to the present invention;

[0073] Figure 2c-2 : A perspective view showing an embodiment 2c-2 of a metering pump according to the present invention;

[0074] Figure 2d : A perspective view showing an embodiment 2d of a metering pump according to the present invention;

[0075] Figure 3a: A perspective view showing an embodiment 3a of a metering pump according to the present invention; and

[0076] Figure 3b : A perspective view showing an embodiment 3b of a metering pump according to the present invention. DETAILED DESCRIPTION

[0077] Figure 1a-1 to Figure 1a-3 The embodiment 1a of the metering pump according to the invention is shown as an example, a combination of a coupling sleeve 7 and a tie rod 3, which is manufactured as a whole. The tie rod is provided with an axial bore 6 for accommodating a socket plate at the end. The coupling sleeve 7 is made of plastic and is applied to the tie rod by injection molding. Alternatively, the coupling sleeve and the tie rod are made in one piece, for example, by machining from metal or by injection molding. The coupling sleeve is equipped with a radial transverse groove opening 8, which is used to allow the socket plate to be inserted and then rotated. Figure 1a-2 An enlarged top view of the coupling sleeve is shown. Figure 1a-3 A perspective view of a tie rod-coupling sleeve combination according to embodiment 1a is shown by way of example. At the end of the component, a radial transverse slot-like opening 8 can be seen for the insertion and subsequent rotation of the socket plate 5 .

[0078] Figure 1b An embodiment 1b of the metering pump according to the invention is shown by way of example. The coupling sleeve and the tie rod are firmly connected by crimping. During the crimping, a fold 9 is formed.

[0079] Figure 1b The structural cross sections marked with AA and BB are schematically shown in Figure 1b-A (Section AA) and Figure 1b-B (Section BB).

[0080] Figure 1b-A The cross section is shown at the transverse groove opening 8 of the coupling sleeve 7. The axial guide of the socket 4 and the socket plate 5 after the rotation of the diaphragm 1 and the diaphragm core 2 are shown schematically.

[0081] Figure 1b-B A section through the coupling sleeve 7 is shown. Also shown are the socket 4 and the socket plate 5. The surface of the socket plate 5 facing the diaphragm is inclined by 1° to 3°, which ensures axial play-freeness (not shown).

[0082] exist Figure 1c An embodiment 1c of a metering pump according to the invention is shown by way of example in . The coupling sleeve 7 and the tie rod 3 each have a thread 10 on their inner side or outer side and are screwed directly to one another.

[0083] exist Figure 1dDetailed description of an embodiment 1d of a metering pump according to the invention is shown in FIG.

[0084] exist Figure 1e 2 shows a perspective view of an assembled diaphragm according to one of the embodiments 1a to 1d. The diaphragm core 2, the connection sleeve 4 and the connection sleeve plate 5 can be seen.

[0085] exist Figure 2a-1 and Figure 2a-2 , a cross section marked with AA of an embodiment 2a of a metering pump according to the invention is shown by way of example, wherein the diaphragm core 2 is provided with a preferably cylindrical coupling means 12 in the direction of the tie rod 3, wherein the coupling means has a groove 13. The tie rod is provided with a first (axial) opening 14 at the end side for accommodating the coupling means 12 and a second (radial) opening 15 for accommodating a component 16 intended for fixing the coupling means 12. The coupling means 12 is fixed by means of a displaceable component 16, which is "locked" into the groove 13 of the coupling means by means of a hook 44 of a half-moon design under the pressure of a compression spring 17.

[0086] Figure 2a-1 The structure before the coupling mechanism 12 is engaged is shown. Figure 2a-2 The structure is shown after this snap-in process.

[0087] exist Figure 2a-3 and Figure 2a-4 The schematic diagrams show the Figure 2a-1 or Figure 2a-2 The cross section through the longitudinal axis of the tie rod 3 and the coupling mechanism 12 is marked with CC, DD and EE. It can also be seen that the coupling mechanism is disassembled by means of a pin 18, which the installer inserts from the outside through a hole (not shown) in the diaphragm retaining plate (or in the drive housing). The displaceable member 16 is then displaced downwards, so that the coupling mechanism 12 is released and can be pulled out. Figure 2a-3 and Figure 2a-4 1 and 2. It is also shown that in order to align the displaceable member 16 in a manner parallel to the tie rod axis, the structure has a cylindrical pin 40. The cylindrical opening 41 of the member 16 must be aligned with the axis of the tie rod 3 in order to enable axial plugging of the coupling mechanism 12. Without the cylindrical pin 40, the position of the opening 41 in the member 16 would not be determined.

[0088] Figure 2a-5 A perspective view schematically shows an assembled diaphragm of an embodiment 2a of a metering pump according to the invention.

[0089] Figure 2a-6Different perspective views and the associated sections marked AA and BB of the displaceable component 16 of an embodiment 2a of a metering pump according to the invention are shown. The opening 43 for the pin 40 can be seen.

[0090] exist Figure 2b 2b of an embodiment of a metering pump according to the invention is shown by way of example, wherein

[0091] The diaphragm core 2 is provided with a cylindrical coupling means 12 in the direction of the tie rod 3, wherein the coupling means has a groove 13. The tie rod 3 is provided at the end side with a first axial opening 14 for accommodating the coupling means 12 and two radial grooves 22 for accommodating the clamp-type coupling device 19. The coupling means 12 is fixed by means of the anti-twist clamp-type coupling device 19.

[0092] exist Figure 2b The structural cross section marked with AA is schematically shown in Figure 2b-1 middle.

[0093] Figure 2b-1 It is shown that the clamp-type coupling 19 consists of two clamp halves clamped by springs 20. The clamp-type coupling 19 is mounted on two parallel transverse grooves 22 of the tie rod 3. The surfaces 21 of the two transverse grooves are used as anti-rotation parts of the clamp-type coupling 19.

[0094] exist Figure 2c-1 2c-1 of the metering pump according to the invention is shown by way of example. The tie rod 3 has a radial transverse hole 23, into which a spring-loaded ball 24 is introduced, for example in accordance with Standard elastic compression piece. The coupling mechanism 12 has an obliquely extending transverse groove 13 with variable depth. The coupling mechanism 12 and the tie rod 3 are connected by staggered plugging and then turning in opposite directions. During the rotation, the ball 24 sinks into the groove 13 until it is locked into its final position and the coupling mechanism is fixed.

[0095] exist Figure 2c-2 A variant of the above-mentioned embodiment 2c-1 of the metering pump according to the invention is shown in FIG. 2c-2. Here, the coupling mechanism 12 has a radial transverse hole 23, into which a spring-loaded ball 24 is introduced, for example, in accordance with Standard elastic pressure piece. The pull rod has a transverse groove 25. The working method in this embodiment 2c-2 corresponds to the working method in embodiment 2c-1. The ball is snapped into the groove 25. The width of the groove 25 determines the torsion angle for aligning the diaphragm.

[0096] exist Figure 2d2d of the metering pump according to the invention is shown by way of example. The tie rod has one or more radial transverse holes 26, into which flat head bolts 27 (screws in accordance with DIN 913) are screwed respectively. The coupling mechanism 12 has a radially circumferential groove 28 for accommodating the bolt tips.

[0097] exist Figure 3a 3a of the metering pump according to the present invention is shown by way of example, the metering pump comprising a diaphragm 1 and a diaphragm core 2, wherein

[0098] The diaphragm core 2 is provided with a screwable clamping socket 29 in the direction of the tie rod 3, a clamping groove 35 is machined into the tie rod 3, and the end side of the tie rod 3 is provided with a clamping connection device 30 driven by a compression spring 39. The clamping connection device has a first clamping hub 31 and a second clamping hub 32, wherein the first clamping hub 31 is machined into the tie rod itself, and the second clamping hub 32 is radially displaceable and fixable. Preferably, the fixing is carried out using a screw 33 with a thread 42.

[0099] exist Figure 3b 3b of an embodiment of a metering pump according to the invention is shown by way of example, wherein

[0100] The diaphragm core 2 has a screwable clamping socket 29 in the direction of the tie rod 3, and the end side of the tie rod 3 has an axially displaceable coupling sleeve 34, which is displaced in the direction of the diaphragm core so that the clamping socket 29 is clamped in a clamping groove 35 machined into the tie rod. In addition, a spring-loaded ball 37 is introduced into the radial transverse hole 36 of the tie rod 3, for example in accordance with Standard elastic pressure piece. In the coupling sleeve 34 there is a corresponding recess 38 for accommodating the ball.

[0101] The features of the invention disclosed in the above description, the claims and the drawings may be essential both individually and in any arbitrary combination for the realization of the invention in its various embodiments.

Claims

1. A metering pump, comprising: (i) a diaphragm return device including a pull rod (3); and (ii) a diaphragm kit comprising a mechanically driven elastic diaphragm (1) having a flexible region between a clamping surface at the edge of the diaphragm for sealing the delivery chamber and a diaphragm core (2) for transmitting force, generating pressure and for connecting to the tie rod, characterized in that The diaphragm kit and the pull rod are connected by means of a hook-type connection, a plug-type connection or a clamping connection.

2. The metering pump according to claim 1, characterized in that The metering pump has a hook-type connection device, The diaphragm core (2) is provided with a preferably cylindrical sleeve (4) in the direction of the tie rod (3), which sleeve preferably carries two plates (5) arranged relative to each other at the end. The pull rod (3) is provided with an axial bore (6) on the end side for accommodating the socket plate (5), and The tie rod (3) is equipped with a coupling sleeve (7) having a radial transverse slot-like opening (8), wherein the opening is used for the insertion and subsequent rotation of the socket plate.

3. The metering pump according to claim 2, characterized in that The connecting sleeve (7) and the pull rod (3) are made in one piece.

4. The metering pump according to claim 3, characterized in that The connecting sleeve (7) and the pull rod (3) are made of metal.

5. The metering pump according to claim 3, characterized in that: The coupling sleeve (7) and the tie rod (3) are made of plastic, or the coupling sleeve is made of plastic and the tie rod is made of metal.

6. The metering pump according to claim 2, characterized in that: The connecting sleeve (7) is connected to the pull rod (3) by means of crimping.

7. The metering pump according to claim 2, characterized in that: The connecting sleeve (7) is directly screwed to the pull rod (3) via a thread (10).

8. The metering pump according to claim 2, characterized in that: The connecting sleeve (7) is fastened to the pull rod (3) by means of bolts (11).

9. The metering pump according to claim 1, characterized in that: The metering pump has a plug-in connection. The diaphragm core (2) is provided with a preferably cylindrical coupling means (12) in the direction of the tie rod (3), wherein the coupling means has a groove (13). The pull rod (3) is provided with a first axial opening (14) at the end side for accommodating the coupling mechanism (12), and The tie rod has a second radial opening (15) which is used to fix the coupling mechanism (12).

10. The metering pump according to claim 9, characterized in that In order to fix the coupling mechanism (12), a displaceable component (16) is arranged in the pull rod (3), which is snapped into a groove (13) of the coupling mechanism (12) in a pressure-locking manner by a compression spring (17).

11. The metering pump according to claim 9, characterized in that In order to fix the coupling mechanism (12), a clamp-type coupling device (19) is arranged on the pull rod (3), which consists of two clamp halves clamped by springs (20) and is mounted on two parallel transverse grooves (22) of the pull rod (3).

12. The metering pump according to claim 9, characterized in that In order to fix the coupling (12), a spring-loaded ball (24) is introduced, preferably screwed, into a radial transverse hole (23) of the tie rod (3), and the recess (13) in the coupling is a transverse groove extending obliquely and having a variable depth.

13. The metering pump according to claim 1, characterized in that The metering pump has a plug-in connection. The diaphragm core (2) is provided with a preferably cylindrical connecting mechanism (12) in the direction of the tie rod (3). The pull rod (3) is provided with a first axial opening (14) at the end side for accommodating the coupling mechanism (12). The tie rod has a transverse groove (25), and In order to fix the coupling, a spring-loaded ball (24) is introduced, preferably screwed, into a radial transverse bore (23) of the coupling.

14. The metering pump according to claim 9, characterized in that In order to fix the coupling (12), a flat-headed screw (27) is screwed into one or more radial transverse holes (26) of the tie rod (3), and the coupling has a radially circumferential groove (28) for accommodating the screw tip.

15. The metering pump according to claim 1, characterized in that The metering pump has a clamping connection. The diaphragm core (2) is provided with a clamping sleeve (29) that can be screwed in the direction of the pull rod (3), a clamping groove (35) is machined into the pull rod (3), and the end side of the pull rod (3) is provided with a clamping connection device (30), which has a first clamping hub (31) and an optional second clamping hub (32), wherein the first clamping hub (31) is machined into the pull rod (3) itself and the optional second clamping hub (32) forms a separate component, which is preferably fastened by screwing.

16. The metering pump according to claim 15, characterized in that The clamping connection (30) has a radially displaceable second clamping hub (32), wherein the second clamping hub (32) can be fixed.

17. The metering pump according to claim 15, characterized in that The clamping connection device (30) has an axially displaceable connecting sleeve (34), which is displaced in the direction of the diaphragm core (2) so that the clamping sleeve (29) is clamped in a clamping groove (35) machined into the pull rod, a spring-loaded ball (37) is introduced and preferably screwed into a radial transverse hole (36) of the pull rod (3), and a corresponding recess (38) for accommodating the ball (37) is present in the connecting sleeve.

18. The metering pump according to claim 12, 13 or 17, characterized in that The spring-loaded ball (24, 37) is in accordance with Standard elastic compression parts.

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