DE20104603U1 - Fluid dispensing valve - Google Patents

Description

ABITZ

European Patent Attorneys European Trademark Attorneys Patent attorneys Abitz & Partner Patent attorneys European Patent and Trademark Attorneys Register Court

Munich PR 18

Postal Address PO Box 86 01 09 D-81628 Munich

16 March 2001 33562-en

Loctite Germany GmbH
Arabellastrasse 17

81925 Munich
Federal Republic of Germany

Valve for dispensing a fluid

Description

The invention relates to a valve for dispensing a fluid.
The valve has a housing in which there is a channel and a
The channel has a passage for the fluid that opens into or crosses it. In the channel, a valve body is positioned between two positions
arranged slidably. By pneumatic pressure
the valve body can be moved from one position to the other
Position, whereby in one position it allows the passage
closes and releases it in the other position.

&iacgr;&ogr; Generally, the invention relates to a device for dispensing
of a fluid, with a device for receiving a channel
and a culvert opening into or crossing the canal
for the fluid and with a device that is in the
Channel is arranged to be displaceable between two positions and is controllable by pneumatic pressure, the device serving to close the passage in one position and to open it in the other position.

Such valves and dispensing devices are generally known, e.g. from DE-A-37 42 221 and US-A-4,989,792.

A similar, but magnetically controlled valve is known from WO 00/62941.

Cleaning is particularly difficult for valves used to dispense highly viscous liquids and adhesives. Sometimes it is necessary to disassemble the valve.

The invention is based on the object of creating a valve for dispensing a liquid, in which the cleaning and maintenance effort is eliminated or significantly reduced. 15

According to the invention, this object is achieved in that a tubular element is inserted into the channel of the housing and that the valve body is arranged to be movable back and forth in the tubular element.

Generally speaking, this problem is solved by inserting a tubular device into the channel and by arranging the device for opening and closing it in the tubular device.

Simple injection-molded disposable components can be used as the pipe element and housing, so that cleaning is not necessary. The pipe element can in particular be a commercially available cartridge, to the end of which protruding from the housing a cartridge adapter with a compressed air connection for the pneumatic control of the valve can be attached by means of a bayonet connection.

Preferably, the valve body is pressed into one of its two positions by a spring and moved into the other position by compressed air. The valve can be designed in such a way that the valve body is pressed into the

closed position, as well as being pushed or pulled into the open position.

The passage for the fluid is opened and closed by the movement of the valve body. The passage can cross the channel. In a cylindrical housing, for example, the channel can be provided coaxially in the housing, in which case both the inlet part and the outlet part of the passage are arranged radially. It is also possible to provide only the inlet part radially in the housing and to have the outlet part of the passage run coaxially inside the tubular element.

The valve body is generally a cylindrical piston with a control-side end and a product-side end. The spring acts on the control-side end of this valve body and the valve body is pressurized with the compressed gas or the compressed gas is supplied from this side. By moving the valve body, the product-side end can open or close the passage for the product (fluid). A conical valve head is coaxially inserted at the product-side end of the valve body, which is pressed against a valve seat to close the passage and is lifted off the valve seat to open the passage.

The valve seat can be located inside or outside the tubular element. If it is located inside the tubular element, at least the inlet or outlet part of the passage also penetrates the tubular element. In a particularly preferred embodiment of the invention, the tubular element extends over the entire length of the housing and the valve seat and the outlet part are formed at one end of the tubular element. The outlet part can be a simple pipe socket, the inner end of which forms the valve seat.

The spring is generally a tension spring which is arranged on the control side of the valve body. The valve seat can be arranged in such a way that the valve body closes the valve by the spring, or in such a way that the valve body closes the valve by the

Spring opens the valve. The compressed air is connected to the control end of the pipe element and fills the entire cross-section of the pipe.

It is also possible to press the valve body to the product-side end of the housing using a compression spring and to lift it to the control-side end of the housing using the compressed gas. In this case, the compressed gas is fed through a connection piece, a central bore in the valve body and

β a transverse bore into an annular space surrounding the valve body. The valve body is designed as a differential or stepped piston, with the end with the larger diameter facing away from the valve seat, so that the valve body is pressed by the pneumatic pressure against the force of the spring towards the control-side end of the housing.

When using the valve to dispense highly viscous compounds and adhesives, particularly cyanoacrylates, anaerobic adhesives, UV-curing adhesives and acrylates, cleaning the product passage, which is partly in the valve housing and partly in the tubular element, is sometimes very difficult. These parts are therefore not cleaned but only used once. Cleaning the valve body, which consists of a piston and a valve head, is easy. After opening the bayonet lock, the cylinder cap with the spring adapter, the spring and the valve body attached to it can be pulled out of the tubular element. The housing with the inserted tubular element is discarded and replaced with new parts.

Embodiments of the invention are explained below with reference to the drawing.

Fig. 1 shows the first embodiment of the valve in section;

Fig. 2 the first embodiment in a spatial section;

Fig. 3 the second embodiment of the valve in section/

Fig. 4 the second embodiment of the valve in a spatial section;

Fig. 5 the third embodiment of the valve in section;

&iacgr;&ogr; Fig. 6 the third embodiment of the valve in

a spatial section;

Fig. 7 shows the fourth embodiment of the valve in a spatial section;

Fig. 8 the fourth embodiment of the valve in

a spatial section;

Fig. 9 the cartridge adapter for the compressed air connection in a side view;

Fig. 10 the bayonet closure with the cartridge adapter of Fig. 9 in an axial view from the valve housing in the open state and

Fig. 11 the bayonet lock of Fig. 10 in the closed

Condition.

The valve 10 shown in section in Fig. 1 has a valve housing 12 with a passage 15 for a liquid product, the passage 15 being controlled by means of a valve body which is arranged displaceably in a cylindrical channel 20 of the housing 12. The valve body 18 is under the action of a tension spring 22 and is controlled pneumatically.

The valve housing 12 is cylindrical with a product-side end 24 and a control-side end 26. At the product-side end 24 is the passage 15 for the product. This

consists of a radial inlet part 14 and an axial outlet part 16. At the entrance of the inlet part 14 there is an internal thread 28 for product supply. The inlet part 14 opens into the axial channel 20 and continues into an axial outlet part 16, which is coaxial to the channel 20 and exits from the housing 12 at the product-side end face. A valve seat 30 is located in the transition from the inlet part 14 to the outlet part 16.

A tubular element 32 is inserted into the axial channel 20, which protrudes from the control-side end of the channel 20 and extends to the point where the inlet part 14 opens into the channel 20. The tubular element 32 is relatively thin-walled and is made of plastic. Its nominal diameter is slightly larger than the inner diameter of the channel 20, so that it is inserted into the channel 20 with a press fit. The valve body 18 moves within the tubular element 32 and is sealed by two circumferential seals 34, 36 in the tubular element 32. The end of the tubular element protruding from the valve housing 12 has wing-like or flange-like radial projections 38. These projections are encompassed by a cartridge adapter 40, which together with the projections 38 forms a bayonet connection and is used to connect the valve 10 to a compressed air source. The cartridge adapter 40 has an axial plug-in nipple 42 onto which a compressed air hose can be pushed. The end 46 of the cartridge adapter 40 facing the valve housing 12 is tubular and is received by the tubular element 32 with a small amount of play. O-rings seal the outside of the tubular end 46 against the inside of the tubular element 32. A spring adapter 48, also tubular, is screwed into the end 46 of the cartridge adapter 40. The tension spring 22 is suspended from a cross bolt 50 in the spring adapter 48 and another cross bolt 52 in a recess 54 at the control-side end of the valve body 18, so that the valve body 18 is pulled towards the control-side end of the valve housing 12.

VY:

The valve seat 30 is formed by a conical narrowing 56 on both sides of the channel 20 between the mouth of the inlet part 14 and the outlet part 16, namely by the conical surface of this narrowing facing the product-side end. A mushroom-shaped valve head 60 is screwed into the product-side end of the valve body 18, the widened head of which has a conical surface facing the valve seat 30. This conical surface is pulled against the valve seat 3 by the tension spring 22, so that the valve 10 is normally closed.

&iacgr;&ogr; The spring 22 is not shown with its individual turns in all figures, but only by its envelope. By supplying compressed air via the cartridge adapter 40, the valve body 18 can be moved against the force of the spring 22 to the product-side end 24, the valve then opening so that the product, e.g. a highly viscous adhesive, is dispensed from the outlet part 16 via the inlet part 14, past the valve seat 30. In the area of the outlet part 16, the channel 20 is widened in stages and a screw 62 is screwed into the widened area, which has a central bore 64 into which a dispensing nozzle 66 is screwed from the outside. This screw 62 is also used to adjust the end position of the valve body of the opened valve 10. This makes it possible to adjust the dosing rate and the amount of product to be dispensed that is sucked back.

To maintain and clean the valve 10, the adjusting screw 62 is unscrewed with the outlet nozzle 66. In order to be able to pull out the valve body 18 by opening the bayonet lock on the control end of the valve 10, the valve head 60 is first unscrewed from the valve body 18. Cleaning the inlet part 14 and the valve seat 30 is laborious and the valve housing 12 with the pipe element 32 seated therein is therefore not reused. These are simple injection-molded parts with low manufacturing costs. The other parts that come into contact with the product, such as the product-side end of the valve body 18, the valve head 60, the adjusting screw 62 and the outlet nozzle

66 can be cleaned without any problem, since all passages are easily accessible from the outside. The other parts of the valve 10, in particular the control-side end of the valve body and the tension spring 22, do not come into contact with the product, so that cleaning is not necessary here anyway. These parts are therefore inserted into a new valve housing 12 with a pressed-in pipe element 32 and secured by means of the bayonet lock. The valve head 60 is then screwed on and the adjusting screw 62 and the output nozzle 66 are screwed in.

3 and 4 show a second embodiment in longitudinal section, which differs from the embodiment of Fig. 1 and 2 in that both the inlet part 14 and the outlet part 16 of the passage 15 run radially to the axis of the valve housing 12. The inlet part 14 and the outlet part 16 are offset along the axis of the valve housing 10, so that the inlet part 14 opens into or leaves the channel 20 on one side and the outlet part 16 on the other side of the valve seat 30. In this embodiment too, the channel 20 is widened in stages at the end on the product side and a screw 62 is screwed in here, although there is no central hole in the second embodiment. Here too, the dosing rate and the amount of product to be dispensed can be adjusted using the screw 62.

Fig. 5 and 6 show a third embodiment in longitudinal section, which differs from the embodiments of Fig. 1 to 4 in that the pipe element 32 extends over the entire channel 20. The passage 15 therefore also penetrates the pipe element 32 and the valve seat 30 is formed in the pipe element 32, for which purpose the inside of the pipe narrows conically towards the discharge nozzle 66. This valve 10 is normally open.

For maintenance, only the bayonet lock needs to be opened, whereupon the cartridge adapter 4 0 with the

Spring adapter 48 and the valve body 18 hanging thereon by the tension spring 22 can be pulled out of the valve housing 12 and the tubular element 32.

Fig. 7 and 8 show a fourth embodiment, which is normally closed and is opened by supplying compressed air. The passage 15 is designed in the same way as in the third embodiment. In order for the valve 10 to be closed in the resting state, the valve body 18 is

Î a compression spring 22 is pressed against the valve seat 30. The compression spring 22 is supported against the inner edge of the cartridge adapter 40. A spring adapter is not provided here. The compressed air is fed into an axial plug nipple 70 at the control-side end of the valve body 18 and exits the valve body 18 laterally into an annular space 78 between the valve body 18 and the tubular element 32. The control-side end of the valve body 18 is sealed against the inside of the tubular element 32. Towards the product side, the diameter of the valve body 18 decreases gradually up to the valve head 60, which is cylindrical overall and is screwed axially into the piston at the product-side end. The valve head 60 is sealed against the valve head 60 and the inside of the pipe element 32 by means of a ring 72 and O-rings 74, 76 on the inside and outside of the ring 72. When compressed air is supplied through the plug nipple 70 into the annular space 78 between the valve body 18 and the pipe element 32, the valve body 18, which acts here as a differential piston, is displaced on the control side so that the valve head 60 lifts off the valve seat 30 and the passage 15 to the discharge nozzle is opened.

When servicing the valve 10 shown in Fig. 7 and 8, the cartridge adapter 40 is removed. The tension spring 22 then falls out and the valve body can be pulled out using the compressed air hose pushed onto the plug nipple 70. The ring 72 remains hanging on the valve head 60 or is pulled out of the tubular element 32' by means of a needle angled at the front end.

The cartridge adapter 40 is shown in a side view in Fig. 9 and Fig. 10 and 11 show the bayonet closure in the open and closed state from below. The cartridge adapter 40 has an oval cross plate 80 with two pockets 82, each open in the same direction of rotation, at the ends of the longer cross dimension. The lugs 38 on the control-side end of the tubular element 32 are also part of an oval cross plate 84 when viewed in the axial direction. As can be seen in Fig. 10, the cross plate 84 with its smaller dimension fits between the pockets 82. By rotating through 90°, the lugs 38 are received in the pockets 32, whereby the cartridge adapter 40 is locked onto the end of the tubular element 32.

The pipe element 32 and the cartridge adapter 40 are simple injection-molded parts made of plastic. The various O-rings are made of EPDM. The remaining components of the valve 10 can be injection-molded or turned/milled parts.

A particular advantage of the valve according to the invention is that it can be manufactured largely from commercially available components. A cartridge such as that offered by GTL Gesellschaft für Löttechnik mbH, D-75173 Pforzheim, under order numbers 5109, 5110, 5111, 5112, 5113 can be used as the pipe element 32. A cartridge adapter 40 from the same company can be used, such as that offered under order numbers 1000Y5148 to 1000Y5152. In the first two embodiments (Fig. 1 to 4), the end of the cartridge on the product side is cut off. The type N-M5-PK-3 or -4 from Festo AG & Co. can be used as the plug nipple 70.

With the materials specified in the following list of reference symbols, the valve 10 according to the invention is compatible with the following adhesives:

Cyanoacrylate

11 anaerobic adhesives UV-curing adhesives Acrylates

12

List of reference symbols

with material information for the respective components (Sp=injection molding; D/F=turned/milled part)

10 Valve

12 valve housing (POM, D/F or Sp)

14 Inlet part

15 Passage

16 Outlet part

18 Valve bodies (POM, D/F or Sp)

20 Channel

22 Spring (spring steel)

24 Product end

26 tax side end

28 internal thread

30 Valve seat

32 Pipe element (PP, Sp, disposable, EFD + GLT)

34 seals (PTFE/steel)

3 6 Seals (EPDM)

38 approaches (PP)

40 cartridge adapters (PC, Sp, reusable, EFD + GLT)

42 . Plug nipple (PC)

44 O-ring (EPDM)

46 tubular end

48 spring adapter (aluminum, D/F)

50, 52 Cross bolt (VZA)

54 recess

56 Constriction

60 Valve head (POM, D/F or Sp)

62 Screw (POM, D/F or Sp)

64 Hole (POM)

66 Discharge nozzles (PP)

70 plug nipples (galvanized steel, reusable, Festo)

72 Ring (POM, D/F or Sp)

74, 76 O-ring (EPDM)

78 Annular space

80 Cross plate (PC)

82 Bag

84 Cross plate (PC)

Claims (8)

1. Valve for dispensing a fluid, with a housing ( 12 ) in which there is a channel ( 20 ) and a passage ( 15 ) for the fluid which opens into the channel or crosses it, with a valve body ( 18 ) which is arranged so as to be displaceable in the channel ( 20 ) between two positions and is controllable by pneumatic pressure, wherein in one position it closes the passage ( 15 ) and in the other position it opens it, characterized in that a tubular element ( 32 ) is inserted into the channel ( 20 ) and that the valve body ( 18 ) is arranged in the tubular element ( 32 ). 2. Valve according to claim 1, characterized in that the valve body ( 18 ) is loaded by a spring ( 22 ) and is displaced by the pneumatic pressure against the force of the spring ( 22 ). 3. Valve according to claim 1 or 2, characterized in that the channel ( 20 ) has a conical constriction which forms a valve seat ( 30 ), that the valve body ( 18 ) consists of a piston and a mushroom-shaped valve head ( 60 ), the piston being arranged on one side of the constriction and the widened valve head ( 60 ) on the other side of the constriction and that the inlet part ( 14 ) of the passage ( 15 ) opens into the channel ( 20 ) in the region of the constriction. 4. Valve according to claim 1 or 2, characterized in that the tubular element has a conical constriction which forms the valve seat ( 30 ), the inlet part ( 14 ) of the passage ( 15 ) opening into the channel ( 20 ) at the constriction through the tubular element ( 32 ). 5. Valve according to one of the preceding claims, characterized in that a cartridge adapter ( 40 ) can be detachably fastened to the end of the tubular element ( 32 ) and that the spring ( 22 ) is fastened to the cartridge adapter ( 40 ) as a tension spring, so that the valve body ( 18 ) can be pulled out of the tubular element ( 32 ) by the spring ( 22 ) by means of the cartridge adapter ( 40 ). 6. Valve according to one of claims 1 to 4, characterized in that the spring ( 22 ) is a compression spring and that the compressed gas used to control the valve is supplied via an axial channel of the valve body ( 18 ) and exits into an annular space between the valve body ( 18 ) and tubular element ( 32 ) and that the valve body ( 18 ) is designed as a stepped piston so that it can be lifted off the valve seat ( 30 ) by supplying compressed gas against the force of the spring ( 22 ). 7. Valve according to one of claims 1 to 6, characterized in that the tubular element ( 32 ) extends over the entire length of the channel ( 20 ). 8. Device for dispensing a fluid, - with a device ( 12 ) for receiving a channel ( 20 ) and a passage ( 15 ) for the fluid opening into or crossing the channel and - with a device ( 18 ) which is arranged in the channel ( 20 ) so as to be displaceable between two positions and which is controllable by pneumatic pressure, the device serving to close the passage ( 15 ) in one position and to open it in the other position, characterized, - that a tubular device ( 32 ) is inserted into the channel ( 20 ) and - that the opening and closing device ( 18 ) is arranged in the tubular device ( 32 ).