Air pump silencer, air pump equipped with said air pump silencer, and paint spraying device equipped with at least one air pump

Abstract

To provide a pneumatic pump silencer free from influence of condensation water accumulation and icing, and compact enough to be integrated into a cover of a pneumatic pump.SOLUTION: A pneumatic pump silencer (1) includes a body (6) defining an inner volume (V6) and having at least one wall (62) including an air outlet orifice (64), and an attenuating pad (8) having a face (8A) arranged across from the air outlet orifice (64), where a gap is arranged between the face (8A) of the attenuating pad (8) and an outer face (62A) of the wall (62) including the air outlet orifice (64), the thickness of the gap (10) being between 0.5 mm and 5 mm.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a pneumatic pump silencer comprising a body having at least one wall defining an interior volume and having an air outlet orifice, the pneumatic pump silencer further comprising a damping pad having a surface opposite the air outlet orifice. [Background technology]

[0002] Generally, a pneumatic pump includes an air motor that is powered by compressed air. A pneumatic piston pump generally includes two variable volume chambers arranged around a piston attached to a shaft. These two variable volume chambers are alternately supplied with and exhausted from compressed air, causing the piston to move back and forth. The motion of the piston is transferred to the shaft and used to drive another device, such as a liquid paint pump.

[0003] If the chamber is connected to an air exhaust line, the compressed air exhausted from the air motor is not discharged directly to the outside air, because the sudden expansion of the compressed air would generally cause a loud noise due to the fact that the compressed air has not yet reached atmospheric pressure. It is therefore known to use an exhaust circuit that includes a noise attenuation system called a silencer. Summary of the Invention [Problem to be solved by the invention]

[0004] The principle of some known mufflers is to completely seal the air discharge orifice and to diffuse the compressed air through a porous material, either a cellular foam, or a ceramic material, or a metal or plastic material formed by partially sintered beads. These porous materials can be incorporated into ready-to-use mufflers. However, these mufflers have relatively cumbersome problems and are difficult to integrate into the cover of the air motor part of the air pump.

[0005] That is, the moisture contained in the air may condense and accumulate in the heat collector and silencer due to the cooling caused by the sudden expansion of the compressed air. In particular, when the air pump is continuously used, ice may form on the heat collector and silencer of the air pump, which reduces the cross-sectional area of ​​the air discharge passage and reduces the performance of the air pump.

[0006] The present invention more specifically aims to address the above problems by proposing a pneumatic pump silencer that is not affected by condensate build-up and ice formation, even in the case of continuous use, and that is compact enough to be integrated into the cover of the pneumatic pump. [Means for solving the problem]

[0007] To achieve the above object, the present invention is an air pump silencer having a gap disposed between a surface of a damping pad and an outer surface of a wall containing an air outlet orifice, the gap having a thickness of 0.5 mm to 5 mm. Effect of the Invention

[0008] The pneumatic pump muffler of the present invention allows for better drainage of condensed water towards the outside of the muffler, which prevents the muffler from icing and ensures sustainable reversal performance in case of continuous use, i.e., the exhaust of the pneumatic pump is not hindered, so that clear reversal and better use comfort are guaranteed.

[0009] According to advantageous but optional aspects of the invention, such a pneumatic pump silencer may incorporate one or more of the following features, considered in any technically permissible combination: - The damping pad is made of porous material, whose Shore hardness is not less than 20. the material of the damping pad is elastomer, the Shore hardness is equal to 20-100, preferably 30-40 and even more preferably 35; - The material of the damping pad has a porosity between 0 and 0.75. the damping pad completely covers the air outlet orifice and the area of ​​the face of the damping pad that is positioned opposite the air outlet orifice is at least 120% of the area of ​​the air outlet orifice, preferably at least 150% of the area of ​​the air outlet orifice. - The orientation of the gap allows for gravity drainage of condensate. The damping pad is attached to the body via a support attached to the body, the support defining a side wall including the air outlet orifice and a receiving volume for the damping pad. The damping pad is mounted so that its outer surface can be moved closer to or further away from the surface of the wall containing the air outlet orifice.

[0010] According to another aspect, the present invention relates to a pneumatic pump including an air motor and at least one air discharge orifice. The pneumatic pump includes an air motor having two variable volume chambers separated by a piston, and an air distribution subassembly that distributes air toward and exhausts air from the variable volume chambers, the air distribution subassembly having at least one air discharge orifice, and the pneumatic pump further includes an air pump silencer that is disposed downstream of the air discharge orifice in the direction of exhaust flow of the air distribution subassembly, and an internal volume of the body of the pneumatic pump silencer that covers the air discharge orifice. The pneumatic pump also includes two air discharge orifices and an air pump silencer disposed downstream from each air discharge orifice in the exhaust flow direction, and the internal volume of the body of each pneumatic pump silencer covers the corresponding air discharge orifice. The air distribution subassembly and the pneumatic pump silencer are disposed within an interior volume of a casing which is closed by a layer of open-cell foam, preferably made from polyurethane.

[0011] The invention also relates to a paint spraying device comprising at least one pneumatic pump as described above and a pump for paint driven by said pneumatic pump.

[0012] This paint sprayer provides the same advantages as those discussed above with respect to the pneumatic pump silencer of the present invention.

[0013] The invention will be more clearly understood and other advantages will appear more clearly in the light of the following description of one embodiment of a pneumatic pump silencer, a pneumatic pump and a paint spraying device according to its principle, given by way of non-limiting example only and made with reference to the accompanying drawings, in which: [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a perspective view of an air pressure pump according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a cross-sectional view of the pneumatic pump taken along plane II of FIG. [Diagram 3] FIG. 3 is a partially exploded perspective view of the pneumatic pump of FIGS. 1 and 2, particularly showing an pneumatic pump silencer according to an embodiment of the present invention. [Figure 4] FIG. 4 is a front view of detail IV as seen in the direction of arrow F4 in FIG. [Diagram 5] FIG. 5 is a partial perspective view of a paint spraying device consisting of the pneumatic pump of FIGS. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] It should be noted that each figure shows the same orthogonal coordinate system of axes XYZ, and the "up" and "down" directions for the interpretation of terms such as "up", "down", "upper side", "lower side", "top" and "bottom" are directions to be considered along axis Z, which is the mounting direction of the pneumatic pump or its components.

[0016] An air pump 100 is shown in Figure 1. The air pump 100 is shown here in an installed state, with certain elements omitted from the illustration to facilitate understanding of the operation of the air pump 100.

[0017] The pneumatic pump 100 comprises a pump cylinder 105 having a circular cross section and oriented along an axis Z 105 parallel to the axis Z.

[0018] The pump cylinder 105 is closed at one end by an upper cover 105A and at the other end by a lower cover 105B. The upper cover 105A and the lower cover 105B have a similar structure and are arranged opposite each other at the two ends of the pump cylinder 105. Each cover 105A, 105B includes an inner part 105D, which has a circular cross section and can be inserted into the pump cylinder 105, said insertion being sealed using an O-ring 105J.

[0019] Each cover 105A, 105B further comprises an outer part 105E. The face of each outer part 105E of each cover 105A, 105B, whose normal is parallel to the axis Z and facing away from the pump cylinder 105, has several bosses with holes capable of receiving various fastening elements such as screws. In particular, the bored bosses of the lower cover 105B receive metal rods 107A. These metal rods 107A form a pump chassis for a liquid product pump 204 belonging to a spraying device 200 shown in FIG. 5, apart from the pneumatic pump 100. Besides the pneumatic pump 100 and the liquid product pump 204, the liquid product pump 204 comprises a sprayer 206 and a pipe 208 fluidly connected to the sprayer 206 for transferring the liquid product from the liquid product pump 204 to the sprayer 206.

[0020] The sprayer 206 is suitable for spraying the liquid product on a target surface, not shown, and is, for example, a manual gun as in FIG. 5, or a known automatic sprayer. The sprayer 206 is preferably of the airless type, i.e. capable of spraying the liquid product without adding atomizing air. In this sense, the spraying device 200 is an airless type spraying device. To that end, the pressure of the liquid product supplied to the sprayer 206 by the liquid product pump 204 must be higher, for example, than 30 bar.

[0021] The liquid product pump 204 includes a body 215 having a suction opening or inlet opening 212 for sucking in the liquid product and a discharge opening or outlet 210 for discharging the liquid product through a pipe 208 towards a sprayer 206. The inlet opening 212 is, for example, equipped with a check gate. The inlet opening 212 is also fluidly connected to a liquid product tank 207 via a pipe 209.

[0022] In the main body 215, a piston (not shown) is provided to define a cylindrical compression chamber and is attached so as to slide along an axis parallel to the axis Z. The piston of the liquid product pump 204 is connected and fixed to the piston 104 of the pneumatic pump 100 by the shaft 106. That is, the liquid product pump 204 is driven by the pneumatic pump 100.

[0023] The upper cover 105A and the lower cover 105B are held in place by fastening rods 105C.

[0024] The pneumatic pump 100 also includes a piston 104 located inside the pump cylinder 105. The piston 104 is attached to a shaft 106 having an axis Z105. The shaft 106 further passes through an upper cover 105A and a lower cover 105B, and the shaft 106 is sealed between the upper cover 105A and the lower cover 105B by a sealing member (details of which will be omitted).

[0025] A piston 104 having a circular portion is inserted into a pump cylinder 105, and a seal gasket 104J attached around the piston 104 provides a seal at the contact portion with the pump cylinder 105. A chamber defined by the pump cylinder 105, the piston 104, and the upper cover 105A is referred to as an upper chamber 102A, and similarly, a chamber defined by the pump cylinder 105, the piston 104, and the lower cover 105B is referred to as a lower chamber 102B. The piston 104 is translatable along an axis Z105, and when the position of the piston 104 in the pump cylinder 105 changes, the volumes of the upper chamber 102A and the lower chamber 102B also change. Thus, the upper chamber 102A and the lower chamber 102B are variable volume chambers.

[0026] An upper duct 112A is disposed in the upper cover 105A. One end of the upper duct 112A opens in an inner part 105D of the upper cover 105A in the upper chamber 102A. The other end of the upper duct 112A opens in a direction parallel to the axis X from an outer part 105E of the side surface of the upper cover 105A in a direction away from the axis Z105. Similarly, a lower duct 112B is disposed in the lower cover 105B. One end of the lower duct 112B opens in an inner part 105D of the lower cover 105B in the lower chamber 102B. The other end of the lower duct 112B opens in a direction parallel to the axis X from an outer part 105E of the side surface of the lower cover 105B in a direction away from the axis Z105.

[0027] The contact support 110 is fastened to the outer portion 105E of the upper cover 105A. The contact support 110 is formed in a long and narrow rectangular plate shape, and is arranged such that the long side is along the axis Z, and the contact support 110 is arranged in a direction perpendicular to the axis Y. The contact support 110 includes a lower end portion close to the upper cover 105A and an upper end portion distant from the upper cover 105A.

[0028] The lower contact 110B is fixed near the lower end of the contact support 110, and the upper contact 110A is fixed near the upper end of the contact support 110. The upper contact 110A and the lower contact 110B each include a lever 111 and a bearing roller 111A.

[0029] The pneumatic pump 100 also includes a casing 114. The casing 114 is comprised of a bottom portion 114A, an upper rim 114B and a lower rim 114C. The bottom portion 114A is flat and lies in the plane of the axes Z and Y, i.e. perpendicular to the axis X. The upper rim 114B and the lower rim 114C are opposite each other and extend perpendicular to the bottom portion 114A along the axis X. The bottom portion 114A, the upper rim 114B and the lower rim 114C define a housing, the internal volume of which is designated V114.

[0030] A lower passage 116B is disposed in the bottom 114A of the casing 114 near the lower rim 114C. A tap hole 120 having an axis parallel to the axis X is disposed on both sides of the lower passage 116B in the direction of the axis Y. Similarly, an upper passage 116A is disposed in the bottom 114A of the casing 114 near the upper rim 114B. Further, a tap hole 120 is disposed in the bottom 114A on both sides of the upper passage 116A.

[0031] The pneumatic pump 100 also includes an air supply member 2. The air supply member 2 has a free end 2A adapted to be connected to an external compressed air source, such as a compressor or tank, not shown. Compressed air from the external compressed air source generates a reciprocating motion of the piston 104 and the shaft 106. The air supply member 2 is connected at its other end 2B to a base 4. The base 4 has an overall parallelepiped shape, each face perpendicular to the axes X, Y, and Z, and on one of the faces perpendicular to the axis X, the base 4 has a platen 4A from which several ducts and air passages issue. In this platen 4A, from bottom to top, the lower exhaust duct 43B, the lower air passage 42B, the intake duct 41, the upper air passage 42A, and the upper exhaust duct 43A can be seen.

[0032] The paths of these various ducts and air passages are also shown in Figure 2, in which the base 4 is shown in cross section. In particular, the upper air passage 42A and the lower air passage 42B each have an end that appears on the platen 4A, and the other ends of the upper air passage 42A and the lower air passage 42B on the base 4 are on the opposite side of the platen 4A, i.e., the side facing the casing 114, opposite the base 4 from the upper passage 116A and the lower passage 116B, respectively. The upper exhaust duct 43A and the lower exhaust duct 43B each have an end that extends above the platen 4A, and the other end is an upper exhaust orifice 44A or a lower exhaust orifice 44B, which are respectively positioned above or below the platen 4A in an orientation parallel to the axis Z.

[0033] The intake duct 41 has one end appearing on the platen 4A and the other end appearing on one of the side surfaces of the platen 4A perpendicular to the axis Y.

[0034] The platen 4A further includes holes 4B, the axes of which are parallel to the axis X. The base 4 includes through holes 46 near the upper and lower surfaces, the axes of which are parallel to the axis X.

[0035] An air distributor 12 is disposed opposite the platen 4A. The air distributor 12 has a generally parallelepiped shape with faces perpendicular to the X, Y and Z axes. The air distributor 12 has an unreferenced hole parallel to the X axis and capable of receiving a fastening screw 12A.

[0036] For the sake of clarity of the drawing, the air distributor 6, which is known per se, is shown in outline in FIG.

[0037] In FIG. 2, the piston 104 is in the so-called lower position, ie the piston 104 abuts against the lower cover 105B, the lower chamber 102B has a minimum volume and the upper chamber 102A has a maximum volume.

[0038] The cam 108 is fixed to the shaft 106 and therefore follows the same alternating upward movement along arrow F1 or downward movement along arrow F2 as the shaft 106. In the lower position of the piston 104 as shown in Figure 2, the cam 108 is in contact with the bearing roller 111A of the lower contact point 110B.

[0039] The lower contact 110B and the upper contact 110A have a similar structure, with a bearing roller 111A fastened to a lever 111, which is connected to the body of the upper contact 110A or the lower contact 110B. The upper contact 110A and the lower contact 110B act as valves, allowing the compressed air to pass when the bearing roller 111A moves and blocking the passage when the bearing roller 111A is in the nominal position. Note that the control air circuits of the upper and lower contacts are not shown in the figures of this disclosure. In Figures 1 and 2, the cam 108 moves on the bearing roller 111A of the lower contact 110B.

[0040] As its name suggests, the air distributor 12 distributes air coming from the intake duct 41 toward the upper air passage 42A or the lower air passage 42B, and at the same time connects the upper air passage 42A and the lower air passage 42B to the corresponding exhaust ducts. That is, the upper air passage 42A is connected to the upper exhaust duct 43A, and the lower air passage 42B is connected to the lower exhaust duct 43B. The air distributor 12 is pneumatically controlled by compressed air circuits connected to each of the upper and lower contacts 110A, 110B.

[0041] When the air pressure pump 100 is mounted, the air distributor 12 is fastened to the platen 4A of the base 4 using fastening screws 12A that cooperate with holes 4B arranged in the platen 4A. The air distributor 12 thus mounted on the base 4 and the base 4 together form an air distribution subassembly 14. When the air pressure pump 100 is mounted, the air distribution subassembly 14 is disposed in the internal volume V114 of the casing 114. Also, at this time, the upper air passage 42A is aligned with the upper passage 116A arranged in the bottom 114A of the casing 114 and the upper duct 112A arranged in the upper cover 105A. Similarly, at this time, the lower air passage 42B of the base 4 is aligned with the lower passage 116B of the bottom 114A of the casing 114 of the lower duct 112B of the lower cover 105B. The assembly of the air distribution subassembly 14, the casing 114, the upper cover 105A and the lower cover 105B includes a sealing member capable of providing a sealing connection between the upper air passage 42A, the upper passage 116A and the upper duct 112A on the one hand, and a sealing member capable of providing a sealing connection between the lower air passage 42B, the lower passage 116B and the lower duct 112B on the other hand.

[0042] 1 and 2, the air pressure command sent by the lower contact 110B controls the air distributor 12, so that the intake duct 41 is connected to the lower air passage 42B through the air distributor 12, and the upper air passage 42A is connected to the upper exhaust duct 43A. At this time, the upper chamber 102A is connected by the upper duct 112A from the upper passage 116A and the upper air passage 42A to the upper exhaust duct 43A, and then to the upper exhaust orifice 44A. At this time, the pressure therein is substantially equal to atmospheric pressure.

[0043] Conversely, the compressed air coming from the air supply member 2, passing through the intake duct 41, the air distributor 12, the lower air passage 42B, the lower passage 116B and the lower duct 112B in this order, reaches the lower chamber 102B. The pressure at this time is approximately equal to the pressure of the compressed air supplied by the air supply member 2. Under the influence of the above pressure, the piston 104A moves in the direction of the arrow F1, i.e., upward, along the axis Z105.

[0044] Just before the air distributor 12 reverses, the upper chamber 102A is still under the pressure of the compressed air coming from the intake duct. During the reversal of the air distributor 12, the upper chamber 102A is suddenly connected to the air discharge orifice 44, causing a sudden expansion of the exhaust air, which is reflected in a potentially significant noise and cooling associated with the decompression of the compressed air.

[0045] Compressed air naturally moves from areas of higher pressure to areas of lower pressure. More specifically, when one of the variable volume chambers 102A, 102B, which is initially under pressure, is connected to one of the upper exhaust duct 43A and the lower exhaust duct 43B, the flow of compressed air is performed in the direction of the arrows F3 or F4, respectively, up to the level of the upper exhaust orifice 44A or the lower exhaust orifice 44B. This flow direction defines a downstream direction relative to the upper exhaust orifice 44A or the lower exhaust orifice 44B.

[0046] Thus, after the reversal of the air distributor 12, the piston 104 moves upwards until the cam 108 reaches the bearing roller 111A of the upper contact 110A. Under command of the pneumatic control signal sent by the upper contact 110A to the air distributor 12, the latter reverses itself again. The lower chamber 102B, which was previously connected to the air supply member 2 by the lower duct 112B, the lower passage 116B and the lower air passage 42B, is suddenly connected to the lower exhaust duct 43B, which is connected to the lower exhaust orifice 44B. Conversely, the upper chamber 102A, which was previously in exhaust state, is connected to the air supply member 2 by the various passages mentioned above. Under the effect of the pressure reversal, the piston 104 is pushed in the direction of the arrow F2 and is lowered again until it reaches the lower position, where the cam 108 comes into contact with the bearing roller 111A of the lower contact 110B, which is the state shown in Figs. 1 and 2.

[0047] The cycle of alternating movement of the piston 105 and shaft 106 described above is transmitted to the liquid product pump 204 .

[0048] The air pressure pump further includes a foam layer 20 and a perforated cap 21. The foam layer 20 is formed in a plate shape having a thickness E20.

[0049] The pneumatic pump 100 further includes two pneumatic pump silencers 1 .

[0050] The pneumatic pump silencer 1 comprises a generally cubic body 6, the faces of which are perpendicular to the axes X, Y and Z. The body 6 is hollow and defines an internal volume V6. The internal volume V6 is open on two of the six faces of the body 6, the open faces being adjacent, one of which has a normal parallel to the axis X and facing towards the casing 114, and the other open face has a normal parallel to the axis Z. The body 6 has two side walls 62 which are perpendicular to the axis Y. The outer surface 62A of each side wall 62 is the surface whose normal along the axis Y faces away from the body 6.

[0051] An air outlet orifice 64 is disposed in each side wall 62. That is, the air outlet orifice 64 passes through the side wall 62 and exits from the interior volume V6 to the outside of the main body 6. The air outlet orifice 64 is disposed approximately in the center of the corresponding side wall 62.

[0052] The body 6 further includes a solid wall 65 and a front wall 68. When the body 6 is in a state in which the pneumatic pump 100 is attached, the solid wall 65 is perpendicular to the axis Z, and the front wall is parallel to the axes Y and Z.

[0053] The normal to the front wall 68 is parallel to the axis X and points away from the casing 114. In the front wall 68 two through holes 68A are further arranged, parallel to the axis X, which pass through the body 6 in the thickness of the solid wall 65.

[0054] The side wall 62 is also pierced with bores 66 oriented parallel to the axis Y, which bores 66 also extend through the thickness of the solid wall 65 .

[0055] Each pneumatic pump silencer 1 comprises two damping tabs 8. These damping tabs 8 consist of identical plates of parallelepiped shape, the faces of which are perpendicular to the axes X, Y and Z. Reference E8 denotes the thickness of the damping tab 8 measured along the axis Y. The damping tab 8 has a first face 8A perpendicular to the axis Y, as well as a second face 8B and a third face 8C perpendicular to the axis Z.

[0056] The two through holes 82 are located on the first surface 8A of the damping tab 8 near the corner between the first surface 8A and the second surface 8B of the damping tab. Furthermore, guide cutouts 81 are located on the first surface 8A of the damping tab 8 near the third surface 8C, and these guide cutouts 81 have a rectangular cross section in a plane perpendicular to the axis Y.

[0057] Each pneumatic pump silencer 1 also comprises two identical supports 16. Each support 16 includes a rectangular base 16A oriented perpendicular to the axis Y. At one of the corners of the base 16A parallel to the axis X, the base 16A includes a bearing rim 16B. The bearing rim 16B is parallel to the axes X and Y. At the other corner of the base 16A parallel to the axis X, the support 16 also includes two spacing legs 16C oriented parallel to the axis Y of the base 16A on the same side as the bearing rim 16B.

[0058] The spacing legs 16C have a substantially rectangular cross section in a plane perpendicular to the axis Y. The ends of the bearing rim 16B and the spacing legs 16C are perpendicular to the axis Y and lie in the same plane parallel to the axes X and Z. The bottom 16A of the support 16, its bearing rim 16B and the spacing legs 16C define a receiving volume V16 for receiving the damping pad 8, the reference P16 indicating the depth of the receiving volume V16 in the direction parallel to the axis Y.

[0059] The through holes 16D are arranged parallel to the axis Y in the bottom 16A of each support 16, near the corner between the bottom 16A and the bearing rim 16B, and these through holes 16D are connected to the receiving volume V16.

[0060] Each pneumatic pump silencer 1 further comprises a first thread 18A and a second thread 18B, the first thread 18A being shorter than the second thread 18B.

[0061] When the pneumatic pump silencer 1 is mounted, each damping pad 8 is received in a receiving volume V16 of the support 16. The spacing legs 16C and the guide notches 8B have complementary shapes which cooperate within any assembly play to limit the movement of the damping pads 8 in the receiving volume V16. Movement of the damping pads 8 relative to the support 16 is permitted only in a direction parallel to the axis X.

[0062] When the pneumatic pump silencer 1 is installed, the bearing rim 16B and the spacing legs 16C of its support 16 contact the side wall 62 of its body 6. Furthermore, the through hole 16D of the support 16 is aligned with one of the bores 66 of the body 6, allowing for the placement of a first screw 18A that secures each support 16 to the body 6.

[0063] When the damping pad 8 is inserted into the receiving volume V16 of the support 16, the through-hole 82 of the damping pad 8 is also aligned with the through-hole 16D of this support 16. The diameter of the through-hole 82 is selected to be slightly larger than the diameter of the first screw 18A so as not to restrict the translational movement of the damping pad 8 along the axis of the first screw 18A.

[0064] The depth P16 is strictly greater than the thickness E8 of the damping pad 8. As a result, when the support 16 is fastened to the body 6 by means of the first screw 18A and the damping pad 8 is placed in the receiving volume V16, the damping pad 8 is pressed against the bottom 16A of the support 16 under the effect of the exhaust pressure of the variable volume chambers 102A, 102B and does not come into contact with the adjacent outer surface 62A of the side wall 62 of the body 6. A gap 10 is thus formed between the first surface 8A of the damping pad 8 and the adjacent outer surface 62A of the side wall 62 of the body 6. The symbol E10 denotes a thickness in a direction parallel to the axis Y, which thickness E10 is not zero.

[0065] The pneumatic pump silencer 1 can be constructed by assembling the support 16, the damping pad 8, and the body 6 using the first screw 18A. Furthermore, the pneumatic pump silencer 1 can be assembled into the air distribution subassembly 14 by fastening the second screw 18B through the through hole 68A of the body 6 and the through hole 46 of the base 4, and cooperating with the tapped hole 120 of the casing 114. In this assembled state, as shown in FIG. 2, the body 6 of each pneumatic pump silencer contacts the base 4, and the upper exhaust orifice 44A or the lower exhaust orifice 44B appears in the internal volume V6 of the body 6. In FIG. 2 and FIG. 3, the arrows F3 and F4 indicate the direction of the air exiting the upper exhaust orifice 44A and the lower exhaust orifice 44B. The exhaust air exiting the exhaust orifices 44A and 44B first spreads into the internal volume V6. In other words, the body 6 covers the air discharge orifice 44.

[0066] Each time the pressure is reduced, the sudden cooling of the air promotes condensation of the moisture present in the air and also promotes ice formation inside pump ducts and mufflers designed according to the state of the art.

[0067] The pneumatic pump silencer 1 according to the invention is compact enough to be integrated in the internal volume V114 of the casing 114 above each exhaust orifice 44A, 44B. The exhaust pressure in the internal volume V6 of the body 6 is reduced faster than in the case of collectors according to the state of the art, which allows a cleaner reversal of the air distributor 12 and an increase in the productivity of the pneumatic pump 100. The reduced volume of the pneumatic pump silencer 1 makes it possible to place the pneumatic pump silencer 1 according to the invention at each exhaust orifice 44A, 44B while limiting the volume in the internal volume V114 of the casing 114. This makes it possible to place a second sound-absorbing element consisting of a foam layer 20 and to accommodate the air distribution subassembly 14 covered by the pneumatic pump silencer 1 in the internal volume V114 of the casing 114.

[0068] The foam layer 20 is, in this example, a polyurethane foam plate, which is shaped and held in place by the perforated cap 21. As shown in FIG. 3, various openings are arranged in the foam layer 20 to allow the fasteners of the perforated cap 21 to pass through and the air supply member 2 to pass through. That is, the foam layer 20 surrounding the air distribution subassembly 14 and the pneumatic pump silencer 1 in the casing 114 must allow the exhaust air to escape through the foam layer 20. To this end, the material of the foam layer 20 must have open cells. The foam layer 20 can be made, for example, from an open-cell polyurethane foam.

[0069] When the exhaust air leaves the exhaust orifices 44A, 44B, it reaches the internal volume V6 of the body 6 of the pneumatic pump silencer 1, which covers the exhaust orifices 44A, 44B, and expands to the entire available space of the internal volume V6. The pressure of the exhaust air then exerts a force on the damping pads 8. This pressure is applied perpendicularly to the first face 8A of each damping pad 8. When placed in the receiving volume V16 of the support 16, each damping pad 8 has a certain play and can move in translation, in particular along the axis of the first screw 18A passing through the damping pad 8, as shown by the arrows F8 and F8' in FIG. 4. Since the thickness E8 of the damping pad 8 is strictly smaller than the depth of the support 16, the damping pad 8 is pressed against the bottom 16A of the support 16 under the pressure of the exhaust air. The space between the outer face 62A of the side wall 62 of the body 6 and the first face 8A of the damping pad 8 thus constitutes the gap 10.

[0070] The exhaust air leaving one of the exhaust orifices 44A, 44B passes through the internal volume V6 and then through the gap 10 to reach the internal volume V114 of the casing 114. Any condensation water formed in the internal volume V6 during the sudden decompression of the exhaust air leaving the exhaust orifices 44A, 44B is carried away by the air passing through the gap 10. In addition, the gap 10 is oriented in a vertical plane, i.e. parallel to the axis Z, allowing the flow of condensation water occurring in the internal volume V6 by gravity. Thus, the condensation water is discharged from each pneumatic pump silencer 1 and appears in the internal volume V114 of the casing 114. Condensation water discharge holes 118 are arranged in the lower rim 114C of the casing 114 to avoid the accumulation of condensation water in the casing 114.

[0071] The exhaust air leaving the air exhaust orifice 44 generates sound waves due to the sudden reduction in pressure. The damping pad 8 is made from a porous material that is able to absorb these sound waves.

[0072] The material used to manufacture the damping pad 8 must have sufficient rigidity, because a damping pad 8 made from an excessively soft material would not be able to withstand the repeated shock waves caused by the exhaust air released with each reversal of the air distributor 12. Sufficient rigidity means that the Shore hardness of the material must be at least 20. If an elastomeric material is used for the damping pad 8, the Shore hardness of the material must be within the range of 20 to 100, preferably 30 to 40. Porous materials that satisfy these hardness conditions are, for example, closed-cell polyurethane foam or rubber. In the case of rubber, an example of a Shore hardness that satisfies the present invention is 35.

[0073] In a variant not shown, the damping pad 8 can be made of porous metal, for example partially sintered bronze beads. According to another variant, the damping pad 8 can be made of porous ceramic.

[0074] The porosity of the constituent material of the damping pad 8 can be defined by the ratio between the volume of the free space and the total volume of the porous medium. In practice, this porosity is expressed as: Φ = V pores / V total where Φ is the porosity, V pores is the total pore volume of the porous medium, V total is the total volume of the material, i.e., the sum of the solid volume and the pore volume.

[0075] The porosity Φ is preferably selected from the range of 0 to 0.75.

[0076] According to another definition, the porosity of the constituent material of the damping pad 8 can be defined by the air flow rate through this pad under a given pressure difference expressed in MPa.

[0077] Schematically, the attenuation of the sound waves of the exhaust is achieved by multiple reflections of the sound waves between the outer surface 62A of the side wall 62 of the body 6 and the first surface 8A of the attenuation pad 8 during the passage of the exhaust in the gap 10. An excessively thin gap 10 in thickness E10 is undesirable, since the exhaust cannot escape fast enough and the reversal of the air distributor 12 is hindered. Conversely, if the thickness E10 of the gap 10 is too large, it reduces the effectiveness of the attenuation of the sound waves, since this would result in the exhaust escaping directly to the outside air, i.e., exhaust without any attenuation device.

[0078] In practice, a gap 10 with a thickness E10 smaller than 0.5 mm tends to obstruct the air pressure pump, while a gap 10 with a thickness E10 larger than 5 mm no longer has a damping effect. Therefore, the thickness E10 of the gap 10 is in the range of 0.5 mm to 5 mm. Preferably, the thickness E10 of the gap 10 is satisfactory between 1 and 3 mm. Furthermore, the thickness E10 of the gap 10 is preferably between 1.5 and 2.5 mm. More preferably, the thickness E10 of the gap 10 of 2 mm gives good results.

[0079] Similarly, the length of the gap 10 measured along any direction perpendicular to the axis Y must be sufficient to allow multiple reflections of sound waves between the first surface 8A of the damping pad 8 and the outer surface 62A of the body 6. The air outlet orifice 64 is located approximately in the center of the side wall 62. When viewed in a direction parallel to the axis Y, the damping pad 8 completely covers the air outlet orifice 64, and preferably the damping pad extends well beyond the edge of the air outlet orifice 64. In particular, the area of ​​the first surface 8A of the damping pad 8 arranged opposite the air outlet orifice 64 is at least 120% of the area of ​​the air outlet orifice 64, and preferably at least 150% of the area of ​​the air outlet orifice 64. This means that preferably the coverage of the air outlet orifice 64 by the damping pad 8 is evenly distributed over the entire circumference of the air outlet orifice 64.

[0080] The pneumatic pump 100 of the disclosed embodiment includes two identical pneumatic pump silencers 1, each including two identical damping pads 8. As a variant, it is possible, as a first example, for the pneumatic pump 100 to have only one pneumatic pump silencer, optionally attached to a collector, and, as a second example, for the pneumatic pump to have an pneumatic pump silencer 1 including only one damping pad 8, or conversely, for the pneumatic pump to have an pneumatic pump silencer 1 including three or more damping pads 8.

[0081] In yet another variant, the two damping pads 8 of the pneumatic pump silencer 1 may be different.

[0082] In another variant, the damping pad 8 of the pneumatic pump silencer 1 can be made from a non-porous material, ie a material with a porosity equal to zero.

[0083] The present invention is not limited to paint spraying. The pump 204 can be utilized to move other liquids, such as water, oil, ink, or single or two-component liquid adhesives. Additionally, the pneumatic pump 100 can be used to drive devices other than pumps, such as pneumatic valves.

[0084] The above-described embodiments and modifications can be combined with each other to create new embodiments of the present invention.

Claims

1. a body (6) defining an internal volume (V6) and having at least one wall (62) including an air outlet orifice (64); and a damping pad (8) including a surface (8A) disposed opposite said air outlet orifice, a gap (10) is disposed between a surface (8A) of the damping pad (8) and an outer surface (62A) of a wall (62) containing the air outlet orifice (64); the thickness (E10) of said gap (10) is between 0.5 mm and 5 mm, preferably between 1 mm and 3 mm, more preferably between 1.5 mm and 2.5 mm, and even more preferably equal to 2 mm, The damping pad (8) is attached to the body (6) by a support (16) fastened to the body (6), A pneumatic pump silencer (1), characterized in that the support defines the wall (62) containing the air outlet orifice (64) and a receiving volume (V16) for the damping pad.

2. In the pneumatic pump silencer (1) according to claim 1, The pneumatic pump silencer (1), wherein the damping pad (8) is made of a porous material and has a Shore hardness of 20 or more.

3. In the pneumatic pump silencer (1) according to claim 1 or 2, A pneumatic pump silencer (1), characterized in that the material of said damping pad (8) is an elastomer, the Shore hardness of which is between 20 and 100, preferably between 30 and 40, and even more preferably equal to 35.

4. In the pneumatic pump silencer (1) according to any one of claims 1 to 3, An air pressure pump silencer (1) characterized in that the material of the damping pad (8) has a porosity between 0 and 0.

75.

5. In the pneumatic pump silencer (1) according to any one of claims 1 to 4, The air pressure pump silencer (1), characterized in that the damping pad (8) completely covers the air outlet orifice (64), and the area of ​​the surface (8A) of the damping pad arranged opposite the air outlet orifice is 120% or more of the area of ​​the air outlet orifice, preferably 150% or more of the area of ​​the air outlet orifice.

6. In the pneumatic pump silencer (1) according to any one of claims 1 to 5, An air pump silencer (1), characterized in that the direction of the gap (10) allows gravity flow of condensed water.

7. In the pneumatic pump silencer (1) according to any one of claims 1 to 6, The pneumatic pump silencer (1), characterized in that the damping pad (8) is attached so that the surface (8A) can be moved closer to or farther away from the wall (62) including the air outlet orifice (64).

8. 1. A pneumatic pump (100) comprising an air motor having two variable volume chambers (102A, 102B) separated by a piston (105) and an air distribution subassembly (14) for distributing air to and from said variable volume chambers, The air distribution subassembly has at least one air discharge orifice (44A, 44B); The air pump further comprises an air pump silencer (1) according to any one of claims 1 to 7, the pneumatic pump silencer is disposed downstream of the air discharge orifice (44A, 44B) in a flow direction of the exhaust gas; An air pump (100) characterized in that an internal volume (V6) of the body of the air pump muffler covers the air discharge orifice.

9. 9. The pneumatic pump (100) of claim 8, The pneumatic pump comprises two air discharge orifices (44A, 44B) and an air pump silencer (1) according to any one of claims 1 to 6, which is disposed downstream of each air discharge orifice in the exhaust flow direction, An air pump (100) characterized in that the internal volume (V6) of the body (6) of each air pump muffler covers a corresponding air discharge orifice.

10. A pneumatic pump (100) according to claim 8 or claim 9, The air pump (100) is characterized in that the air distribution subassembly (14) and the air pump silencer (1) are arranged in an internal volume (V114) of a casing (114) closed by a layer (20) of open-cell foam, preferably made from polyurethane.

11. A paint spraying device (200) comprising at least one pneumatic pump (100) and a paint pump (204) driven by the pneumatic pump (100), characterized in that the pneumatic pump (100) is one according to any one of claims 8 to 10.

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