JPS63111B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention comprises a casing having compressed air inlet and outlet nozzles and a passageway connecting the compressed air inlet to a compressed air outlet; a manually operable control valve governing passage through the passageway; This control valve is equipped with a safety valve connected in series, and is configured so that the passage is blocked by the safety valve when dynamic pressure exceeding a limit value occurs downstream of this safety valve. This invention relates to a type of compressed air spray gun.

Compressed air spray guns of this type are used for cleaning tools and workpieces during machining operations in factories, in particular for blowing away cutting debris and blowing through drilled holes.

The casing of the compressed air spray gun has a compressed air inlet and an outlet nozzle and a passage connecting the compressed air inlet and the compressed air outlet. The compressed air passing through this passage is controlled by a manually operable control valve, for which elements such as gun grips, hammers (or triggers), etc. can be used, among others.

The control valve is pretensioned in the closed position and is opened more or less widely by the operator when attempting to eject a stream of compressed air from the outlet nozzle. The control valve makes it possible to connect and disconnect the compressed air flow and to adjust its intensity.

A safety valve can be provided in the housing of the compressed air spray gun, which is connected in series with the control valve and located in the flow path of the compressed air. The purpose of this safety valve is to prevent a powerful jet of compressed air from being directed at impact surfaces, such as the workpiece to be cleaned or parts of the operator's body, damaging them or causing injury. The goal is to avoid doing so.

This safety valve is configured to limit the working pressure of the compressed air spray gun to a relatively low value, ie a value of approximately 2.5 bar according to current safety standards. Furthermore, the safety valve is configured to interrupt the compressed air flow in such operating conditions so as to preclude operation by the compressed air spray gun in close proximity to the impact surface.

To achieve this purpose, a safety valve is connected in the compressed air stream before or after the control valve. If a dynamic pressure exceeding a predetermined limit value occurs downstream of the safety valve, the passage leading to the compressed air is blocked by the safety valve.

Known compressed air spray guns of this type require considerable manufacturing engineering waste, since their individual parts have to be shaped differently, and the shape of their external contours depends on the requirements during operation. cannot be satisfied satisfactorily.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to eliminate these drawbacks and provide a compressed air spray gun that is particularly ergonomically excellent and that can be easily and inexpensively manufactured and assembled.

In order to solve this problem, the invention provides a compressed air spray gun of the type mentioned at the outset, in which the casing is made of three plastic parts that can be inserted into one another, and that also has a grip that can be gripped by hand. one axial end having a region and an opening for a compressed air inlet on the end side and bent at an angle of about 90° to this;
an L-shaped shell having another axial end defining the direction of the compressed air outlet; a valve insert fitted within the shell to define a flow path for the compressed air; On the outlet side,
a nozzle head adjacent to the valve insert and accommodating the outlet nozzle, said plastic parts accommodating all valve elements and operating members between the parts;
They are pinned to each other through holes drilled during assembly.

Further advantageous embodiments of the invention are indicated in the claims 2 to 12.

Next, the present invention will be described in detail based on embodiments shown in the accompanying drawings.

Compressed air spray guns have a casing made entirely of plastic.
The main idea of the invention is to construct all the casing parts in such a way that manufacturing from plastic can be achieved without difficulty and at the same time assembly can be carried out quickly with only a few operations.

To this end, the casing consists of three plastic parts that can be fitted into each other.

The first casing part is configured as an L-shaped shell 1, which forms the outer wall of the compressed air spray gun over a large area and defines the basic shape of the spray gun. It's on. One axial end of the outer shell 1 is an end surface 2,
It is configured as a substantially cylindrical hollow body 3 curved into a hemispherical shape. This hollow body 3 forms the grip area of the compressed air spray gun, which can be held in the hand.

An operating member 4 for controlling the control valve 5 is installed within this grip area. The end face 2 of the hollow body 3 is provided with an opening 6 for a compressed air inlet. Into this opening 6 is inserted a connecting tube 7 which can be constructed, for example, as a standardized hose coupling or as part of a quick-connection connection unit and which provides a connection to a source of compressed air.

The other axial end 8 of the shell 1 is bent at an angle of approximately 90 DEG to the grip area of the spray gun. This axial end 8 defines the assembly position of the outlet nozzle 9 and the direction of the compressed air outlet, that is to say in a direction extending approximately at right angles to the grip area with the actuating element 4.

The compressed air is thus deflected by approximately 90° as it passes through the casing, and the jet of compressed air is directed approximately at right angles to this grip area.

Such an arrangement is extremely advantageous and facilitates operation, for example, when blowing out a perforation. This is because the spray gun can be held perfectly and conveniently.

A valve insert 10 is fitted into the inner chamber of the outer shell 1 and forms a flow path for compressed air. The valve insert 10 is an L-shaped hollow profile that is open on both sides and has an inlet bushing 11 in the region of the compressed air connection.

This inlet bushing 11 has a substantially cylindrical shape, and its open end faces toward the opening 6 of the outer shell 1. The internal dimensions of the inlet bushing 11 are approximately equal to the diameter of the opening 6, and the inside of the inlet bushing 11 is configured to supply pressurized air to the valve insert 1.
A connecting tube piece 7 leading into the 0 is engaged in a fitting manner.

The end face of the connecting tube 7 rests on a shoulder 12 of the inlet bushing 11, and the diameter of the inlet bushing 11 is reduced in the area of this shoulder 12. The connecting tube piece 7 is sealed inside the inlet bushing 11 by an O-ring 13, and is held in its installed position by two insertion pins 14 so as not to be lost.

The inlet bushing 11 has a first tube section 15 of the valve insert 10 at its axial extension.
is integrally molded. This pipe portion 15 extends substantially parallel to the longitudinal direction of the hollow body 3 through the center of the hollow body 3 forming the grip area of the compressed air spray gun, and extends through the valve chamber 16 of the control valve 5 . It opens inwardly, in particular above the valve element 17, which is pretensioned into the closed position.

The valve chamber 16 is surrounded by a sleeve-shaped valve insert extension 18 which is directed towards the first tube section 15 . This additional part 18 fits onto a nipple 19 which is integrally molded with the outer shell part 1. The nipple 19 is generally cylindrical and has a once stepped external contour. An O-ring 20 is fitted onto the outer circumferential surface of the nipple 19 so as to come into contact with a step in the circumferential direction of the nipple 19 .

The valve insert 10 is placed over the nipple 19 by means of the open end face of the extension 18, with the
The enlarged diameter section in the appendage 18 is O
It is in close contact with the letter ring 20. Valve insert 1
0 is at the same time fixed in the clamping seat of the shell part 1 and closely connected to the shell part 1 in this way.

The bottom of the cylindrical extension 18 is tapered and forms a valve seat 21 for the valve element 17 which likewise has a tapered sealing element. This valve element 17 is
It is located positively in the valve seat 21 and in this position is loaded by the force of a pressure spring 22, which in this embodiment is a helical spring.

This pressure spring 22 is fitted onto the axial guide extension of the valve element 17 and is supported on the flange of the valve element 17. The other end of the push spring 22 is guided into the nipple 17.

Therefore, the valve element 17 is attached to the nipple 19.
A substantially cylindrical ring-shaped notch 23 is provided that tapers slightly toward the front. This ring-shaped notch 23 is arranged as a bag-shaped notch in the center in the axial direction, and is arranged as a bag-shaped notch in the center in the axial direction.
2 is supported on the bottom surface of this bag-shaped cutout.

In order to save on materials and simplify manufacturing, the axial central region of the nipple 19 is also
Again, a hollow chamber 24 is formed which is open towards the valve element 17. The nipple 19 thus ends up having two ring walls coaxially surrounding each other, and the pressure spring 22 is supported between these ring walls.

The valve element 17 is lifted from the valve seat 21 by a push rod 25. The push rod 25 is axially slidably supported in a guide bush 26 integrally formed on the valve insert 10. The guide bush 26 is coaxial with the extension 18 and protrudes from the face of the valve insert opposite to the extension 18 . Therefore,
This guide bushing 26 is oriented perpendicular to the longitudinal direction of the grip portion of the spray gun.

One end face of the push rod 25, which is closely supported within the guide bush 26, is connected to the valve element 1.
7 and the other end 27 of the push rod 25
protrudes from the guide bush 26. This end 27 has a spherical bevel and is loaded by an actuating member 4 which is pivotably mounted on the housing of the compressed air spray gun.

The valve element 17 is lifted by this actuating element 4 to a variable extent from the valve seat 21, thereby creating a more or less large flow cross section for the compressed air. Therefore,
At the outlet nozzle 9 a jet stream of adjustable intensity can be obtained.

Compressed air passes from the valve chamber 16 into the second tube section 28 of the valve insert 10 .

This tube section 28 is parallel to the first tube section 15 and offset in the direction towards the outlet nozzle 9. That is, it extends in the longitudinal direction of the grip portion.

The first tube section 15 opens into the valve chamber 16 upstream of the valve element 17, whereas the second tube section 28 opens into the valve chamber 16 downstream of and below the valve element 17. It extends from the starting point.

This second tube portion 28 abuts against the base of the safety valve 30 in the valve chamber 29 . Valve chamber 2
9 is formed by an extension 31 of the valve insert 10 which is bent at an angle of approximately 90° from the second tube part 28 and which terminates in the axial direction as an opening bushing 32. There is.

Valve chamber 16 of control valve 5 and safety valve 3
The valve chamber 29 of No. 0 is located on opposite sides of the valve insert 10 and substantially parallel to the axis.

Bent extension 31 of valve insert 10
has a concentric ring-shaped notch 33 that is open on the outlet side, and this notch 33 also has a
It is also configured as a bag-shaped cutout.

The ring-shaped recess 33 is bounded on the radially outer side by the wall of the opening bushing 32, whereas on the radially inner side there is a gap between the ring-shaped cutout 33 and the central flow channel 34 for compressed air. , one tube piece 35 remains. This tube piece 35 serves as a guide and a valve seat for a valve element 36 in the safety valve 30.

The valve element 36 has a central perforated disc-shaped base block 37, at one axial end of which a guide collar 3 of decreasing diameter is provided.
8 is integrally molded.

The valve element 36 is axially slidably fitted over the tube piece 35 via this guide collar 38 . In this case, the base block 37 abuts the tube piece 35 with its inner circumferential surface and the wall of the opening bushing 32 with its outer circumferential surface. At this opening bush 32, the base block 37 is sealed by a circumferential tongue.

Therefore, the space of the ring-shaped cutout 33 is
It is hermetically separated from the compressed air flow path and is depressurized towards the outside air via a load relief passage (not shown).

The adjustment spring 3 is located inside the ring-shaped notch 33.
9 is provided. One end of the adjusting spring 39 rests on the bottom surface of the annular recess 33, and the other end loads the valve element 36. This adjustment spring 39 is connected to the guide collar 39.
The base block 37 is wrapped around the outer peripheral surface of the base block 37.
It is in contact with the axial end face of.

The dimensions of the ring-shaped cutout 33 and the valve element 36 are suitably matched to each other; in particular, the outer diameter of the guide collar 38 and the inner diameter of the ring-shaped cutout 33 are approximately equal in their bottom region.

The inner diameter of this ring-shaped notch 33 is
Now, there is a gap between this step 40 and the front edge of the guide collar 38 which is reduced to the dimensions of the through-bore of the valve element 36 and which ensures a sufficient axial adjustment stroke for the valve element 36. remains.

A closing part 41 that covers the opening of the tube piece 35 is integrally molded into the base block 37. Advantageously, this closure 41 projects into the tube piece 35 with a tapered centering point 42 . In close contact with this tube piece 35, the tube piece 35 forms a sealing seat of the closure 41, which is suitable for blocking the flow path 34 for compressed air.

This closed position is obtained by axially sliding the valve element 36 on the tube piece 35 or by increasing the dynamic pressure exerted by the outlet nozzle 9 above a predetermined value. This is due to the deformation of the valve element 36 as it rotates.

This can best be understood by considering the forces acting on valve element 36.
The valve element 36 is initially pretensioned into the open position by the adjusting spring 39, and the closure 41 is lifted from the tube piece 35 in this open position, opening the flow path to the outlet nozzle 9. There is.

Due to the atmospheric pressure created in the annular cutout 33, the forces acting on the sealed base block 37 of the valve element 36 act in the same direction. The closing part 41 of the valve element 36 located within the area of the tube piece 35 then forms a piston surface which receives the operating pressure of the compressed air flowing in through the control valve 5 .

It is the vertical projection of the valve element 36 in the area of the opening of the tube piece 35 that is to be considered as the effective surface of this pressure load. All of the resulting forces thus far tend to slide the valve element 36 on the tube piece 35 into an open position in which compressed air can flow towards the outlet nozzle 9.

Therefore, the safety valve is always open under normal conditions. However, when the compressed air spray gun is held in close proximity to the workpiece to be cleaned or other impingement surface, a dynamic pressure is created on the outlet side by the valve element 36. .

This dynamic pressure loads the outlet side of the base block 37 and the closing part 41, and when the resulting force exceeds the force acting in the opening direction, the valve element 36 moves axially over the tube piece 35. It is slid and the flow path 34 is blocked.

By appropriately setting the dimensions of the valve element 36 and the adjustment spring 39, it is possible to adjust the energy balance at the dynamic pressure safety limit value that can also be tolerated from the outlet nozzle 9 side. Become. When this dynamic pressure limit value is exceeded, the flow of compressed air is interrupted.

Between the second tube part 28 of the valve insert 10 and the tube piece 35 of the safety valve 30, a compressed air deflection of approximately 90 DEG takes place. In a valve insert 10 which is particularly simple in terms of manufacturing technology, it is possible to provide the conduit in the second tube section 28 through the wall of the valve insert 10, with the result that the The opening is closed by a plug 43.

This plug 43 is glued to the valve insert 10. For effective flow deflection, it is advantageous for the plug 43 to be provided with a suitable end face 44 which deflects the air flow in the direction towards the safety valve 30.

The outlet nozzle 9 of the compressed air spray gun according to the invention is housed in a nozzle head 45 which, like the shell 1 and the valve insert 10 previously described, is made of plastic.

This nozzle head 45 adjoins the valve insert 10 on the outlet side and has a tubular end 4
6 through the opening bushing 3 of the valve insert 10
2 and sealed against the opening bushing 32 by an O-ring 47. This O-ring 47 is located between the circumferential tube pieces on the outer wall of the nozzle head 45 or opening bushing 32.

O-ring 47 limits the insertion depth of nozzle head 45 into aperture bushing 32 in this installed position.

The nozzle head 45 has a projection 48 that engages with the end side edge of the shell 1 for connection with other casing parts. Furthermore, this nozzle head 45 has on its outer circumferential surface a cover plate 49 that engages with the opening bush 32 from the outside. This opening bushing 32 is thus located between the tubular end 46 of the nozzle head 45 and the cover plate 49, so that a particularly stable and reliable fixation is achieved.

In the installed state of the nozzle head 45, the tubular end 46, which projects into the opening bushing 32, forms a stop that limits the axial stroke of the valve element 36.

The pipe-like extension 50 of the nozzle head 45, which is used as a stopper, also holds an O-ring 47 on its outer circumferential surface. This pipe-shaped extension 50 rests on the end side against the base block 37 of the valve element 36 and engages on the closing part 41 of the valve element 36 and surrounds the valve element 36 in the open state of the safety valve 30. Forms a casing that allows the flow of water.

An axial connecting channel 51 is connected downstream of the tubular extension 50 in the nozzle head 45, which leads into a housing opening 52 having a larger diameter. The contour of the housing opening 52 is adapted to the outlet nozzle 9 which is fixed within this housing opening 52.

The outlet nozzle 9 has a central feed flow hole 53.
This feed flow hole 53, which is in communication with the axial connecting passage 51 via the outlet nozzle 9, converges towards the tip 54 of the outlet nozzle 9 and reaches a nozzle passage 55, which , to focus the main stream of compressed air so that it can be released.

Furthermore, at least one cut-off passage 56 branches from the supply flow hole 53 toward a circumferential groove 57 provided on the outer peripheral surface of the outlet nozzle 9. A lateral air flow is emitted from around the tip 54 of the outlet nozzle 9 via this circumferential groove 57, which lateral air flow provides fluid-technological advantages and at the same time the outlet nozzle 9. It also has the function of preventing contamination.

Molded in the free end of the nozzle head 45 is a second grip 58 oriented transversely to the outlet nozzle 9.

This second grip 58 extends approximately parallel to the grip area on the shell 1 and is provided to enable comfortable handling of the compressed air spray gun according to the invention with both hands. In order to save material and reduce weight, the grip 58 is constructed as a hollow body, the hollow space of which is designated by the reference numeral 59.

The three casing parts according to the invention made of plastic, namely the shell 1, the valve insert 10 and the nozzle head 45, are fitted into each other in a form-locking manner during assembly so as to be able to fit into each other in a telescoping manner so as to be clamped together. Fixed.

The desired sealing between the respective casing parts is provided by O-rings 13, 20, 47, respectively. These casing parts accommodate all the valve elements and the actuating member 4 between the parts. Moreover, no special fastening means are then required for these parts. Rather, all these casing parts are loosely engaged in and out of each other and brought into their respective functional position when assembled as a casing.

After such parts are assembled,
The shell 1 as a plastic casing element, the valve insert 10 and the nozzle head 45 are drilled and pinned together. A fixation point suitable for using a pin is indicated at 60.

A particular advantage of such a casing construction according to the invention is that material and manufacturing waste is reduced.
The reason is that it is kept to a minimum.

The operating member 4 is supported on a cover plate 49 which projects from the nozzle head 45. Therefore, the free end of the cover plate 49 is formed into a tongue shape that is bent and chamfered into a spherical shape. The actuating member 4 is designed as an L-shaped piece, with a tongue 6 at the end of the longer leg 62.
1, and the tip of this end is tapered.

The longer leg 62 extends from this attachment point to the outer shell 1.
The shorter leg 64 projects obliquely towards the grip area, and from the point of its maximum protrusion 63
is retracted toward the outer shell part 1 at an obtuse angle. The operating member 4 can be lowered into the casing opening of the shell 1 by means of this shorter leg 64 . In this case, the push rod 25 of the control valve 5 is carried away. The push rod 25 abuts the longer leg 62 approximately in its central part via a bulbous end 27.

In its installed state, the actuating element 4 is held securely between the tongue 61 of the cover plate 49 and the edge 65 of the associated housing opening. The shorter leg 64 enters the interior of the shell 1 during the pivoting movement of the operating member 4 . The necessary movement clearance in this case is ensured by the shape of the valve insert 10.

The first pipe section 15 in the valve inserter 10 is
Being located at a sufficient distance from the wall of the grip area ensures that the short leg 64 of the actuating element 4 occupies a position in the hollow body 3. The operating member 4 and thus the control valve 5 are infinitely adjustable by hand.

According to a further embodiment of the invention, it is also possible to provide a device for locking the actuating member 4 in a more or less open control valve or valves flow position. In that case, a stream of pressurized air can thus be ejected continuously from the spray gun. A suitable locking device for this purpose is formed, for example, as a push button.

[Brief explanation of the drawing]

The figure is a longitudinal sectional view showing an embodiment of a compressed air spray gun according to the present invention. DESCRIPTION OF SYMBOLS 1... Outer shell part, 2, 44... End face, 3... Hollow body, 4... Operating member, 5... Control valve, 6...
Opening portion, 7... Connection tube piece, 8... Axial end, 9
... Outlet nozzle, 10 ... Valve insert, 11 ... Inlet bush, 12 ... Shoulder, 1
3, 20, 47... O-ring, 14... Insertion pin, 15... First pipe section, 16, 29... Valve chamber, 17, 36... Valve element, 18, 31
...Additional part, 19...Nipple, 21...Valve seat, 22...Press spring, 23, 33...Ring-shaped notch, 24, 59...Hollow chamber, 25...
Push rod, 26...Guide bush, 27...
... Spherical end, 28 ... Second pipe section, 30 ... Safety valve, 32 ... Opening bush, 34 ... Flow passage, 35 ... Tube piece, 37 ... Base block, 3
8...Guide collar, 39...Adjustment spring, 40...
...Stepped portion, 41...Closing portion, 42...Centering tip, 43...Plug, 45...Nozzle head, 46...Tubular end, 48...Protrusion, 4
9...Cover plate, 50...Pipe-shaped additional part, 51...Connection passage, 52...Casing opening, 53...Supply flow hole, 54...Point, 55...
...Nozzle passage, 56...Cut-off passage, 57...
... Circumferential groove, 58 ... Second grip, 60 ... Pin fixing point, 61 ... Tongue, 62 ... Longer leg, 63 ... Maximum protrusion, 64 ... Shorter leg , 65...edge.

Claims (1)

[Scope of Claims] 1. A casing having a compressed air inlet, an outlet nozzle, a passage connecting the compressed air inlet to the compressed air outlet, a manually operable control valve for controlling passage in the passage, and a control valve for controlling the passage. This type is equipped with a safety valve connected in series, and when dynamic pressure exceeding a limit value occurs downstream of this safety valve, the passage is blocked by the safety valve. A spray gun for compressed air, in which the casing is provided with three plastic parts that can be inserted into one another, in particular with a grip area that can be grasped by hand, and with an opening 6 for the compressed air inlet on the end side. One axial end is bent about 90 degrees with respect to this,
an L-shaped shell 1 having another axial end 8 defining the direction of the compressed air outlet; and a valve insert fitted into the shell 1 and forming a flow path for the compressed air. It consists of a body 10 and a nozzle head 45 adjoining this valve insert 10 on the outlet side and receiving the outlet nozzle 9, said plastic parts 1, 10, 45 being connected to all valve elements. A compressed air spray gun characterized in that an operating member 4 is housed between the parts and fixed to each other with a pin through a hole drilled during assembly. 2. The valve insert 10 has an L-shape and is integrally molded with the inlet bushing 11 with an axial extension, and above the valve element 17 the valve chamber 1 of the control valve 5
A first conduit 15 opening into the first conduit 15 and a safety valve 30 extending below the valve element 17 starting from said valve chamber 16 parallel to and offset from the first conduit 15 It is characterized by comprising a second pipe portion 28 that abuts the base of the valve chamber 29 which is bent by about 90 degrees in the valve chamber 29, and an opening bushing 32 that is integrally molded on the axially extending portion of the valve chamber 29. A compressed air spray gun according to claim 1. 3 The valve chamber 16 of the control valve 5 is connected to each pipe portion 1.
5, 28 and is surrounded by a sleeve-like extension 18 of the valve insert 10 which is oriented transversely to the nipple 1 and which is integrally formed with the outer shell 1. 19. The compressed air spray gun according to claim 2, wherein the compressed air spray gun is fitted on the compressed air spray gun 19. 4. It is noted that the nipple 19 has a cylindrical ring-shaped cutout 23 in which a spring 22 is housed to pretension the control valve 5 in the closing direction. A compressed air spray gun according to claim 3. 5 Valve chamber 16 of control valve 5 and safety valve 3
The compressed air spray gun according to any one of claims 2 to 4, wherein the valve chambers 29 and 29 of the valve insert body 10 are bent toward opposite sides of the valve insert body 10. 6. Claims 2 to 5, characterized in that the conduit in the second pipe section 28 passes through the wall of the valve insert 10 and can be closed by a plug 43. The compressed air spray gun according to any of the above. 7. The compressed air spray gun according to claim 6, wherein the plug 43 is bonded to the valve insert 10. 8 Nozzle head 45 with tubular end 46
is insertable into the opening bushing 32 of the valve insert 10, and a cover plate 49 is provided on the outer peripheral surface of the nozzle head 45 to cover the outside of the opening bushing 32. A compressed air spray gun according to any one of claims 1 to 7. 9. A compressed air sprayer according to claim 8, characterized in that the operating member 4 is supported on a tongue-like piece 61 which is bent and rounded into a spherical shape at the end of the cover plate 49. gun. 10 The operating member 4, via the push button,
The compressed air spray gun according to any one of claims 1 to 9, characterized in that the control valve 5 is lockable at at least one communication position. 11 The safety valve 30 has an axially slidable valve element 36 and the valve element 3
A stroke of 6 is 1 at the nozzle head 45.
Compressed air spray gun according to any one of claims 1 to 10, characterized in that it is limited by two stop positions. 12. On the free end of the nozzle head 45, a second grip 58 is integrally molded, which is oriented transversely to the outlet nozzle 9 and extends approximately parallel to the grip area of the shell 1. A compressed air spray gun according to any one of claims 1 to 11.