EP2376781A1

EP2376781A1 - Device for delivering a gas

Info

Publication number: EP2376781A1
Application number: EP09799249A
Authority: EP
Inventors: Michael Stehle
Original assignee: DOUKAS AG
Current assignee: Illinois Tool Works Inc
Priority date: 2008-12-11
Filing date: 2009-12-11
Publication date: 2011-10-19
Also published as: DE102008061311A1; WO2010066448A1; US20110277877A1; JP2012511655A

Abstract

In a device (P) for delivering a gas out of a pressure chamber (5), in particular into a container (17) for dispensing a sealant (15) from said container into a tire (18) of a vehicle and/or for inflating the tire, wherein a plunger (4) is arranged to be oscillatingly movable in the pressure chamber, a gasket (20) is associated with the plunger and changes the distance thereof from a pressure chamber wall (28) when there is a change in the direction of movement of the plunger.

Description

Device for conveying a gas

The invention relates to a device for conveying a gas according to the features of the preamble of the independent claims 1 and 2.

STATE OF THE ART

From DE 10 2004 042 911 A1 a device for conveying a gas from a pressure chamber, in particular in a container for dispensing a sealant from this container into a tire of a vehicle and for inflating the tire is known. At the disclosed there sealant container, a compressor can be connected. This compressor may also be designed as a diaphragm compressor which compresses air present in the sealing container in order to press sealing means out of the sealant container. A disadvantage of this embodiment is that the air is heated by the compression, but can not be cooled or discharged accordingly. This overheating can lead to failure of the diaphragm pump. Furthermore, it is also disadvantageous that the Membranpumpeπvorrichtung is substantially integrally formed with the sealing container and can not be easily replaced. For example, if the sealing container is empty, the membrane device can be difficult to combine with a new sealing container, which is particularly not environmentally friendly.

TASK

An object of the invention is therefore to provide a device for conveying a gas, which is both environmentally friendly, as well as prevents overheating of the conveyor, is very simple and can be kept small.

SOLUTION OF THE TASK

The object of the invention is achieved by the features of the characterizing part of the independent claims 1 and 2.

Characterized in that the seal by a reciprocating direction of the piston changes its sealing properties, it is possible that the piston sufficient air for compressing and cooling of the piston can be supplied.

Further, the above object is achieved by a device for conveying a gas, characterized in that the piston is associated with a transmission element which converts a rotary movement of a drive shaft of a drive in an oscillating movement.

The simple yet effective design of the transmission element, which acts as a rotation converter, allows the piston to simple and nevertheless, it can be driven in an oscillating manner to move back and forth in an effective manner. This requires no complicated structure, but rather few components that can be easily combined with different drive elements. For example, the drive may be an electric motor, but other drives are also conceivable. It is only essential that the drive element has an output shaft to which the transmission element can be mounted rotationally fixed.

In a preferred embodiment, the seal is a sealing lip which may abut sealingly against a printing cylinder. However, other types of seals are conceivable, it is only essential that the seal is so flexible and elastic that it acts sealingly in an upward movement of the piston and in a downward movement of the piston can solve the sealing effect, so that air can flow past the piston ,

In a preferred embodiment, the seal is eiπstückig formed with the piston. That is, the piston and the gasket are made of the same material, which material must provide a corresponding elasticity, so that the gasket is sufficiently movable, but the piston also has sufficient strength, so that an oscillating motion of a gear means the piston is not damped, but forwarded accordingly.

The piston can be made of rubber. However, other plastics and materials are also conceivable which provide both sufficient flexibility and strength so that the seal can fulfill its sealing and detaching function and the piston can forward the oscillation movement of a transmission element accordingly.

It is also essential that the seal form a peripheral edge which extends to the pressure chamber of the piston, so that a sufficient tightness is provided in the compression step of the piston. in this connection are different forms conceivable, it is only essential that the peripheral edge can form a reversible, airtight connection with the pressure chamber, so that in the upward movement of the piston, the air is compressed. It is essential here that the peripheral edge circumscribes a larger diameter than the diameter of the piston body per se. Because the piston body should have a game to lηnenumfangswand the pressure cylinder, so that air can be sucked in accordance and directed towards the seal.

Further, it is essential that recesses are provided on the seal, which limit the same, so that the function of the suction and compression of the piston is ensured. These Ausπehmungen give the seal its flexibility, so that the seal depending on the direction of movement of the piston can change their sealing effect. The shape of the recess is immaterial. However, it must only be ensured that the recess of the seal of sufficient flexibility and there sufficient air can accumulate, whereby the position of the seal can be changed.

Furthermore, it is essential that below the seal, a further recess in the side circumferential wall of the piston is formed, because this recess has the function that in the downward movement of the piston when new

Air is sucked in, there accumulates air. This air then pushes the

Seal away from the pressure chamber side wall of the pressure cylinder, so that the intake air can flow around the piston body, cool it and accumulate in front of the piston end face of the piston.

The shape of the above recesses is immaterial. It is essential only that the function of pushing away or pressing is ensured by the intake air.

In a preferred embodiment, the recesses are in cross-section substantially drip or U-shaped grooves, one of the Piston end face or on the pressure chamber side wall of the piston are formed substantially circular continuously.

Preferably, the recesses are formed toward the seal with a smaller pitch, wherein the grooves of the side facing away from the seal have a larger curvature / slope, so that a teardrop-shaped groove is formed. In this teardrop-shaped groove, air can accumulate, which is then printed against the seal.

In a preferred embodiment, the lip seal tapers to its Raπdkante preferably such that a substantially V-shaped edge portion is formed.

However, other marginal edge shapes are conceivable as long as it is ensured that the marginal edge rests close to the pressure chamber side wall of the printing cylinder and sealingly or air permeable according to the movement.

In a further embodiment of the invention, the seal is designed as a sealing ring. This results in the advantage that the sealing ring can be replaced when worn in a simple manner.

Preferably, the piston has at least one conical surface. Particularly preferably, the conical surface is provided at a recess on the piston. Particularly preferably, the puncture is provided in an upper region over the entire circumference of the piston. Conveniently, the sealing ring is arranged so that the sealing ring runs during a stroke movement of the piston along the conical surface to the outside until it rests against the pressure chamber wall. As a result, the pressure chamber is advantageously sealed. Preferably, the sealing ring and the conical surface are arranged so that the sealing ring bears against the pressure chamber wall during an upward movement. In a downward movement, when gas, preferably Air, to be sucked into the pressure chamber, the sealing ring is located in an inner region of the recess.

The device of the invention is versatile. Preferably between 10 and 20,000 strokes per minute are possible. More preferably, with the apparatus of the invention, between 20 to 40,000 strokes per minute can be carried out. This is achieved by a very high piston speed. The cam can bsplsw. Be operated 167 revolutions per second. This corresponds to 334 strokes per second and a Kolbengeschwiπdigkeit of 2.34 m / sec.

Preferably, the sealing ring is located in its inner position easily on the pressure chamber wall, but does not take any sealing function. This assists that the sealing ring can assume its sealing position during rapid lifting movements due to frictional forces.

Conveniently, at least one radial groove is provided on the piston. Preferably, the at least one radial groove is provided on a lower surface or inside of the groove. Advantageously, medium, preferably air, flows in the suctioning stroke movement over the radial grooves on the sealing ring.

Advantageously, the piston of this embodiment is not hot in operation. Preferably, the piston is self-lubricating and maintenance-free.

Furthermore, in a preferred embodiment, a force storage element in the form of a compression spring between the piston end face of the piston and the top wall of the impression cylinder is arranged. Preferably, the compression spring is formed of plastic. However, other power storage elements are conceivable, such as elastic rubber stopper. It is essential only that the force storage element provides sufficient force, so that the piston pressed firmly enough against the transmission element of the drive is, so that a constant contact between the piston bottom and transmission element is present.

In a preferred embodiment, the gear member is a double cam having two projections so that the double cam has substantially an elliptical cross-section. However, other Getriebelementformeπ conceivable. For example, that can

Transmission element also be a cam, which has only one projection.

Furthermore, transmission elements with three projections are conceivable. It is essential only that the rotational movement of the drive shaft is converted by the transmission element in an oscillating motion.

The drive is an electric motor in the preferred embodiment. However, other drive elements are conceivable. It is essential only that the output shaft of the drive provides a rotational movement.

In a preferred embodiment, the components of the device are made of plastic.

DESCRIPTION OF THE FIGURES

Further advantages, features and details of the invention will become apparent from the following description of a preferred embodiment and with reference to the drawing; this shows in

Figure 1 is a partial perspective sectional view of an inventive

Apparatus for conveying a gas from a pressure chamber;

Figure 2 is a sectional view of the device of Figure 1 in one

Application;

Figure 3 is a schematic sectional view of another

Embodiment of a piston of a device for conveying a gas from a pressure chamber in a downward movement;

Figure 4 is a schematic sectional view of the other

Embodiment of a piston of a device for conveying a gas from a pressure chamber according to Figure 3 during an upward movement.

As can be seen from FIG. 1, the device P for conveying a gas from a pressure chamber 5 has a drive 1 with an output shaft 2, to which a transmission element 3 is attached in a rotationally fixed manner. The drive 1 is an electric motor in the preferred embodiment.

The transmission element 3 is, as shown in Figure 1, a double cam 3 with a first projection 3.1 and a second projection 3.2. The double cam 3 is mounted on the output shaft 2 such that the two projections 3.1 and 3.2 protrude substantially mirror-symmetrically from the output shaft. The elliptical shape of the double cam 3 converts the rotational movement of the output shaft 2 into an oscillatory motion. The Oscillation movement causes an up and down movement of a piston 4, which is in a pressure chamber 5 (see Figure 2) hm and movably mounted

The piston 4 is biased against the transmission element 3 by means of a force storage element 6, so that the piston is in constant contact with the transmission element 3

The energy storage element 6 is in a preferred embodiment, a helical compression spring, which is used on the one hand in a pocket 7 in the piston 4 and guided by this and on the other hand braced against an upper ceiling wall 29 of the pressure chamber 5

The pressure chamber 5 is defined by a pressure cylinder 25, the pressure chamber ceiling wall 29, which covers the pressure chamber 5 upwards, and a substantially perpendicular to the pressure chamber ceiling wall 29 subsequent pressure chamber side wall 28 which circumscribes the pressure chamber 5 cylindrical and the piston in its retracted position in substantially laterally almost completely surrounds, as seen for example in Figure 2

Furthermore, an outlet opening 9 is formed in the pressure chamber ceiling wall 29 of the pressure cylinder 5, which is formed substantially concentric with the longitudinal center of the pocket 7. The Auslassoffnung 9 is to discharge the compressed air from the piston 4, when a predetermined pressure is built up is one in a Ventilgehause 11 housed check valve 10 is provided which closes the Auslassoffnung 9 until the predetermined pressure in the pressure chamber 5 is constructed by a compression of the air through the piston 4. This pressure is also important for the sealing function of the piston 4 The check valve has one in the valve housing 11 guided valve flap 12, in the middle of a pin 13 is formed, on which a force storage element 14 is attached, which biases the valve flap against the Auslassoffnung 9 The force storage element 14 is in the illustrated embodiment, a spiral compression spring To the valve housing includes a hose connection 30, to which a hose 16, which is shown only schematically in Figure 2, airtight plugged, so that in the pressure chamber 5 compressed gas can be promoted. The hose 16 may either be connected directly to a tire 18 to be inflated at its valve (without reference numeral), or a sealant container 17 may be connected to the hose 16 so that first sealing means 15 and then pumping gas into the tire 18 by means of the device P is pumped. In addition, a connecting line 19, shown only schematically, is connected in an airtight manner to the valve 20 of the tire 18.

The piston is essentially moved between two extreme positions, a retracted position and an extended position. The retraction position shown in FIG. 1 is assumed by the piston 4 when the first or second projection 3.1 / 3.2 of the transmission element 3 is in the position shown in FIGS. 1 and 2. The extended position assumes the piston 4 when the flat portion 3.3 of the transmission element 3 is in contact with the piston. When the piston 4 is moved from the retracted position to the extended position, suction of air and cooling of the piston 4 take place.

When the piston is moved from the extended position to the retracted position, a compression of the sucked air takes place. In this case, a seal 20, which is provided on the piston 4, plays an essential role.

It is bounded by a first recess 21 and a second recess 22. In the preferred embodiment, as shown, the seal 20 is a lip seal 20 that tapers to the pressure chamber side wall 28 of the pressure cylinder 5 and bears against the pressure chamber side wall 28. The first and the second Ausnehmuπg 21, 22 serve that there each air can accumulate and according to the direction of movement of the piston 4, the lip seal 20 either firmly against the Pressure chamber side wall 28 presses so that either air is compressed in front of the piston end face 26, or the lip seal 20 pushes away from the pressure chamber side wall 28, so that air is sucked in front of the Kolbeπstirnfläche 20.

On the piston end face of the piston 4, the first recess 21 is arranged concentrically to the center of the pocket 7, which is substantially riπgfömig and has a substantially groove-shaped cross-section, wherein the wall portion of the groove 21 which faces the lip seal 20, a smaller Has slope or curvature, as the groove portion which extends in the direction of pocket 7. As a result, the first recess 21 has a droplet-like shape which promotes accumulation of air when the piston 4 is moved toward the retracting position.

Air collects increasingly during the upward movement in the first recess 21 and thereby presses the Lippeπdichtung against the pressure chamber side wall 28, whereby the piston automatically seals against the pressure cylinder 25. That the pressure can build up there, is supported by the check valve 10, which only opens when a predetermined pressure is present, which can be adjusted via the force storage element 14 of the check valve 10. When the check valve 10 opens, the compressed air is conveyed via the hose 16, for example, to a tire 18.

Further, a second recess 22 is formed in the pressure chamber side wall of the piston 4, which is similar in cross-section as the first recess, only slightly larger, is formed. The second recess 22 circumscribes the peripheral surface of the piston 4. This second recess 22 serves to move the air through a clearance 23 from the peripheral surface of the piston when the piston is moved in a downward movement toward the extended position by means of the power storage element 6 4 and the inner peripheral wall surface of the pressure space side wall 28 is defined along flows and accumulates in the cross-section teardrop-shaped recess 22, whereby the lip seal 20 is pressed away from the pressure chamber side wall 28, so that the air can flow around the lip seal 20 and accumulate in front of the piston end face of the piston 4. This recirculation simultaneously cools the piston 4, whereby overheating of the entire device can be prevented by the compression process.

The operation of the device for conveying a gas is as follows: Should a tire 18 no longer contain sufficient pressure due to a leak in the hose, the device P can be used for conveying a gas to re-establish a proper pressure in the tire 18.

Further, if the cause of the pressure loss in the tire 18 is a hole in the tube of the tire 18, before inflating with air, a sealant 15 contained in the sealant container 17 may be supplied to the tire. For this purpose, a hose 16 is attached to the bottom end of the sealant container 17, which has a corresponding connection opening. Now, if the drive 1 is set in motion, the drive shaft 2 drives the transmission element 3, which converts the rotational movement of the output shaft 2 in an oscillatory motion by its double cam shape and moves the piston 4 in the pressure cylinder up and down. Here, too, the compression spring 6 plays an essential role, because this pushes the piston back to its original position. This reciprocation of the piston and the design of the lip seal on the piston end face of the piston with the corresponding recesses 21 and 22 causes air to be conveyed to the sealant container 17, which conveys the sealant therein to the leaky tire 18. The sealant spreads due to the pumped gas in the defective hose, seals existing leaks. After the hose is sealed, the hose of the tire 18 is inflated by the device P for conveying a gas. Figures 3 and 4 disclose another embodiment of a device for conveying a gas. This device is constructed analogously to the device of the embodiment described above, but has a different piston 27.1, which is inserted into the pressure cylinder 25 on.

On the piston 27.1, a sealing ring 33 is provided as a seal. For receiving the sealing ring 33, the piston 27.2 has a recess 31. This recess 31 is located in an upper region of the piston 27.1 and extends over the entire circumference of the lateral surface of the piston 27.1.

An inner side of the recess 31 is formed as a conical surface 32. On the opposite inner side or lower surface of the groove, a radial groove 34 is provided. In a further embodiment of the invention, a plurality of radial grooves may be provided on an inner side of the groove.

The operation of this embodiment of the invention is basically analogous to the operation of the embodiment described above. In the following, only the functioning of the seal will be discussed.

FIG. 3 shows the piston 27.1 of the device for conveying a gas during a downward movement in the direction of arrow K. In this case, the sealing ring 33 is located in the groove 31, that gas can be sucked into the pressure chamber 5. In the illustrated embodiment, the sealing ring 33 does not touch the pressure chamber side wall 28 of the pressure cylinder 25.

In a further, not shown embodiment of the invention, the sealing ring may also be arranged so that it rests against the pressure chamber side wall of the printing cylinder in the movement shown in Figure 3, but still does not perform a sealing function. It is still possible that gas is sucked into the pressure chamber. This happens in particular via the grooves.

With or shortly after the beginning of the very rapid upward movement of the piston 27.1 in the direction of arrow G, as shown in Figure 4, the sealing ring 33 changes its position and expands so that it closes a circumferential gap 35 between the pressure cylinder and the piston 27.1. The gas in the

Pressure chamber 5 is then pressed through the outlet opening 9. The expansion is assisted by the fact that the sealing ring runs off the conical surface 32, since it can not follow the speed of the piston due to its inertia and / or because it rests slightly on the inner wall of the pressure cylinder 25 and rubs.

Dres. WEISS & ARAT

Patent Attorneys European Patent Attorπey

Reference: P 3945 / PCT Date: 1 1.12.2009 AM / ST

Claims

claims

1. A device (P) for conveying a gas from a pressure chamber (5) in particular in a container (17) for applying a sealant (15) from this container in a tire (18) of a vehicle and / or for inflating the tire, wherein in the pressure chamber (5) a piston (4) is arranged to oscillate,

characterized,

in that a seal (20) is associated with the piston (4), which changes its distance from a pressure chamber wall (28) when the direction of movement of the piston (4) changes.

2. A device (P) for conveying a gas from a pressure chamber (5) in particular in a container (17) for applying a sealant (15) from this container in a tire (18) of a vehicle and / or for inflating the tire, wherein in the pressure chamber (5) a piston

(4) is arranged oscillatingly movable,

characterized,

that the piston (4) is associated with a transmission element (3) which converts a rotary movement of an output shaft (2) of a drive (1) into an oscillating movement.

3. Apparatus according to claim 2, characterized in that the piston (4) between the transmission element (3) and a force storage element

(6) is arranged, which biases the piston (4) against the transmission element (3).

4. Apparatus according to claim 2 or 3, characterized in that the transmission element is a cam (3) with at least one projection (3.1 / 3.2).

5. Apparatus according to claim 4, characterized in that the cam is a double cam (3) with two projections (3.1, 3.2).

6. Apparatus according to claim 5, characterized in that the double cam (3) is elliptical in cross-section.

7. Device according to one of claims 2 to 6, characterized in that the force storage element between the top wall (29) of the pressure chamber (5), in which the outlet opening (9) is formed, and on the piston end face (26) of the piston (4 ) is arranged.

8. The device according to claim 7, characterized in that the energy storage element (6) on the one hand in a pocket (7) is arranged in the piston end face (26) of the piston (4) and on the other hand on the top wall (29) of the Pressure chamber (5) is supported, in which the outlet opening (9) is formed.

9. Apparatus according to claim 8, characterized in that the force storage element is a compression spring (6).

10.Vorrichtung according to at least one of claims 7 to 9, characterized in that the outlet opening is associated with a check valve (10).

11. The device according to at least one of the claims 2 to 10, characterized in that the pressure chamber (5) from the pressure chamber wall (28) and the pressure space ceiling wall (29) defining a pressure cylinder (25) is defined.

12. The device according to at least one of claims 2 to 11, characterized in that the drive is an electric motor (1)

13. Device according to one of claims 2 to 17, characterized in that the drive (1) has an end wall (8), with which the pressure cylinder (25) is connected.

14. Device according to one of claims 1 to 13, characterized in that the seal is a sealing ring (33).

15. Device according to one of claims 1 to 14, characterized in that the piston (27.1) at least one conical surface

(32).

16. The apparatus according to claim 15, characterized in that the conical surface (32) is provided at a recess (31) of the piston (27.1).

17. The device according to one of claims 14 to 16, characterized in that the sealing ring (33) is arranged so that the sealing ring (33) during a stroke along the conical surface (32) to the outside runs until it at the pressure chamber wall ( 28) is present.

18. Device according to at least one of claims 1 to 13, characterized in that the seal is a lip seal (20).

19. The apparatus according to claim 18, characterized in that the

Seal (20) is integrally formed with the piston (4).

20. Device according to claims 18 or 19, characterized in that the seal (20) is a peripheral edge (24) of the piston (4) to the pressure chamber (5) out.

2 I.Vorrichtung according to claim 20, characterized in that the

Diameter which is circumscribed by the peripheral edge (24) is greater than the outer diameter (A) of the side peripheral wall of the piston (4).

22. Device according to at least one of claims 1 to 21, characterized in that the seal (20) of recesses (21; 22) is limited, which are formed in the piston (4).

23. The device according to claim 22, characterized in that the one recess (21) in the one outlet opening (9) of the pressure chamber (5) facing the piston end face (26) of the piston (4) is formed

24. The device according to claim 22 or 23, characterized in that the other recess (22) in the side circumferential wall of the piston (4) is formed.

25. The device according to at least one of claims 22 to 24, characterized in that the recesses (21, 22) in cross section as substantially U-shaped grooves (21, 22) are formed.

26. The device according to at least one of claims 22 to 25, characterized in that the side of the groove (21, 22) facing the seal (20) has a lower slope / curvature than the side of the groove (21, 22) facing away from the seal.

27. Device according to one of the preceding claims, characterized in that the seal (20) tapers in cross section to the peripheral edge (24).