HK1235351B - De-coring vibrator or pneumatic hammer for de- coring of foundry castings with aluminium alloy jacket - Google Patents

Description

Decoring vibrator or pneumatic hammer with aluminum alloy housing for decoring sand castings

Technical Field

The present invention relates to pneumatic vibrators, also known in the industry as pneumatic hammers, which are used to decoreer castings made of aluminum, steel, and ferrous alloys.

Background Art

For the purposes of this specification, the term "decoring" generally refers to the removal of sand material from a foundry casting.

Also, for the purpose of this specification, the term "casting" refers to a part/object obtained by casting metal in a suitable mold.

Patent WO2007006936 describes an air hammer or a decoring vibrator.

The vibrator or hammer consists of a housing with holes for the entry and exit of compressed air. Within the housing is a mechanical assembly comprising a cylinder in which a piston slides under the influence of compressed air. The piston comes into contact with an impactor, which in turn strikes the casting to be decored.

The hammer includes an attachment flange that allows the hammer to be anchored to the decoring machine by fasteners such as socket head screws.

The casing of the prior art hammer is made of cast iron to ensure the required strength characteristics.

In particular in the field of high-performance decoring hammers, hammers are not known in which the casing is made of a material other than cast iron.

The housing is produced as a single-piece casting.

The use of cast iron significantly increases the overall weight of the hammer and requires more milling work and therefore more labor to produce the hollow bore for accommodating the mechanical components.

The use of cast iron also presents certain limitations in terms of stress tolerance due to the stiffness of the material and the resulting poor damping of vibrations, which can be transmitted to the decoring machine associated with the hammers or vibrators.

It is also known that these hammers are used in hostile environments with very high temperatures. In such working conditions, the operator must perform his or her tasks quickly. Therefore, there is a need for a decoring hammer that can be easily connected to and removed from the decoring machine, such as the one described in patent EP1995002A2.

The solution according to the prior art proves difficult to implement, since the individual compressed air inlet and outlet circuits are arranged in different areas, thus requiring more effort to connect and disconnect the individual air circuits.

Furthermore, the hammer must operate at high temperatures and there is a risk that the mechanism generating the piston movement may be expanded when compressed air is admitted, resulting in increased friction between the components, with the result that the hammer becomes less efficient and requires periodic maintenance.

Decoring hammers require high performance in terms of applied force and piston vibration frequency in order to ensure fast and accurate decoring of metal or alloy castings.

The performance of the hammer is mainly checked by constantly monitoring the pulse frequency of the air leaving the cylinder. This type of check is cheap, but there are many uncertainties.

There are other detection methods that can monitor the vibration frequency of the striking body in the cylinder. This detection is achieved by means of sensors located on the surface of the casing. Usually, the sensors are connected to a processing circuit located outside the hammer.

The sensor is not protected and can therefore be subject to damage, for example by impact, when the hammer is removed.

There are currently no hammers in the art that include an integrated sensor protected against impact; in fact, there is no protection for such a sensor since the casing is made in one single piece and its shape is dictated by standards imposed by the manufacturers of the machines to which such hammers must be applied.

Summary of the Invention

The present invention aims to solve one or more of the above-mentioned technical problems by providing an improved decoring vibrator or hammer having a hammer housing made of a special aluminum alloy in order to achieve the purpose of reducing the total weight of the hammer while keeping the mechanical properties of the hammer substantially unchanged.

One aspect of the invention relates to a hammer having the features as set out in this application.

BRIEF DESCRIPTION OF THE DRAWINGS

Various features and advantages of the hammer will become apparent from the following description of at least one exemplary and non-limiting embodiment of the hammer and from the accompanying drawings, in which:

1A and 1B show different views of a hammer or vibrator according to the invention; in particular, FIG. 1A shows a hammer with an associated measurement circuit, and FIG. 1B shows a side view of a decoring vibrator or hammer according to the invention;

2A and 2B illustrate the hammer or vibrator of FIG. 1 , in particular, FIG. 2A is an exploded view, and FIG. 2B is a side sectional view along a vertical plane;

FIG3 shows a side view of the housing of the hammer or vibrator of FIG2A and FIG2B ;

Figures 4A to 4D show some rear views of the housing of Figure 3; in particular, Figure 4A is a sectional view along plane 4A-4A, Figure 4A shows the connection between the outlet opening and the discharge duct; Figure 4B is a sectional view along plane 4B-4B, Figure 4B shows the discharge duct, the housing for the measuring circuit, and the measuring duct; Figure 4C is a sectional view along plane 4C-4C, Figure 4C shows the connection between the discharge duct, the discharge chamber and the channel for the communication line; Figure 4D is a view of the rear part of the housing, in which the holes for the various circuits are visible.

DETAILED DESCRIPTION

With reference to the figures listed above, the air hammer or the decoring vibrator 2 is suitable for decoring the foundry casting.

The hammer 2 comprises a housing 3 which in turn comprises an inner chamber 32 , an inlet circuit 4 for admitting compressed air and an outlet circuit 5 for discharging compressed air.

Said hammer 2 further comprises, by way of non-limiting example, a connection flange 36, by means of which the hammer 2 can be connected to a decoring machine. Preferably, said connection flange 36 is included in the casing 3 as an integral piece.

One example of an embodiment of the sleeve is shown by way of example in FIG. 3 and FIG. 4A to FIG. 4D .

The hammer 2 further includes a motion mechanism 7 for generating a reciprocating vibration motion under the action of compressed air.

The casing 3 of the hammer 2 according to the invention is made of an aluminum-based alloy.

In an exemplary but non-limiting embodiment, the movement mechanism is arranged so that it can move linearly between the retracted position and the working position along the axis "Z" - which is preferably the longitudinal axis of the hammer 2 itself - under the action of compressed air.

As can be seen, for example, in the exemplary embodiment in FIGS. 2A-2B , the movement mechanism 7 is arranged in the inner chamber 32 of the housing 3 .

The hammer or vibrator 2 also comprises an impactor or beater 6 connected to said movement mechanism 7 and intended to come into contact with the casting to be decored. Said impactor or beater 6 constitutes a first end of the hammer 2.

The movement mechanism 7 is suitable for imparting a vibrating movement to the impactor or beater 6 for the purpose of achieving an optimal decoring effect.

Said movement mechanism 7 is also suitable for moving said impactor 6 at least in a linear manner along said axis “Z”.

The hammer or vibrator 2 further comprises: at least one closing element 62 so that the movement mechanism 7 is retained in the inner chamber 32 of the housing 3; and at least one bushing 64 for maintaining the connection between the impactor or striker 6 and the movement mechanism 7.

The closing element 62 is preferably a plate that is fastened to the first end of the housing 3. The closing element 62 includes a through hole 622. In an exemplary but non-limiting embodiment, the closing element 62 includes a plurality of small holes or nozzles (not shown). The holes are suitable for directing air jets towards the impactor or beater 6. Air from a dedicated supply device flows through the holes and removes sand and dirt from the hammer, thereby preventing early degradation of the hammer. The holes or nozzles are preferably arranged around a circumference with the through hole 622 as the center. Moreover, the holes or nozzles can be shaped so as to produce an air jet that is angled relative to the axis "Z" for directing air towards the cylinder 72. The hammer 2 including the closing element as described above is particularly suitable for application in a rotary core remover.

By way of non-limiting example, the movement mechanism 7 comprises a head 71 for appropriately directing the air flow, a cylinder 72, and a striking body 73 adapted to slide within an inner cavity 722 of the cylinder 72. The movement mechanism comprises an elastic element 74, such as a coil spring.

The elastic element 74 is suitable for exerting a force on the movement mechanism 7 so that the movement mechanism 7 is maintained in either the retracted position or the working position according to the movement of compressed air, as is well known to those skilled in the art. The impactor or striker 6 is connected to the first end of the cylinder 72. At the connection position, at least one bushing 64 is provided. The cylinder 72 passes through the hole 622 included in the closing element 62. When the cylinder 72 moves along the axis "Z" to switch between the retracted position and the working position, the cylinder 72 slides in the hole 722. The shape of the hole 622 is set so that the hole 622 prevents any undesirable tilting of the cylinder relative to the axis "Z" of the cylinder 72 when the hammer 2 is in operation.

The head 71 at the second end of the cylinder 72 is adapted to direct a portion of the air into the inner cavity 722 of the cylinder 72 to move the striking body 73. The movement of the striking body 73 within the cylinder 72 generates a vibratory motion of the cylinder 72. As known to those skilled in the art, the vibratory motion is transmitted to the impactor or striker 6.

As the air introduced into the interior 32 of the housing 3 for moving the movement mechanism 7 is exhausted by means of the outlet circuit 5 , the air is discharged from the interior 32 of the housing 3 through the outlet openings 51 included in the outlet circuit 5 .

The air that has entered the inner cavity 722 of the cylinder 72 is exhausted from the inner cavity 722 through the exhaust through-hole 724 formed in the cylinder 72 .

Since the movement mechanism 7 is well known to those skilled in the art, the movement mechanism 7 is not described in further detail herein.

In a preferred embodiment, the bushing 64 is formed of two assembleable half shells, such as shown in Figure 2 A. Furthermore, the bushing is made of a polyester fiber rubber material such as adiprene.

In an exemplary but non-limiting embodiment, the hammer 2 itself comprises a measuring circuit 8 for measuring the vibration frequency of the movement circuit 7 .

Describing the construction in more detail, the casing 3 is made in a single piece, which preferably includes the connecting flange 36. The casing is made by using a die casting or chill casting process.

As mentioned above, in the hammer 2 according to the present invention, the housing 3 is made of aluminum alloy.

The specific gravity of the aluminum alloy is higher than or equal to 2.60 kg/dm ³ (kilograms per cubic decimeter). The specific gravity of the aluminum alloy is lower than or equal to 2.85 kg/dm ³ .

This unique specific gravity range of the alloy according to the invention is much lower than the characteristic specific gravity of cast iron, which is approximately 7 kg/dm ³ and is the material used in the prior art for manufacturing the casing. This alloy reduces the total weight of the hammer 2 by approximately two thirds.

The alloy has at least 83% by weight aluminum.

The alloy has less than 98% by weight of aluminum.

In summary, the specific gravity of the alloy is comprised between 2.64 kg/dm ³ and 2.86 kg/dm ³ , preferably between 2.65 kg/dm ³ and 2.85 kg/dm ^3. Also, the weight percentage of aluminum is comprised between 83% and 98%, preferably between 91% and 96%.

Preferably, the alloy comprises at least one alkaline earth chemical element, such as magnesium.

Additionally, the alloy preferably includes a semiconductor chemical element, such as silicon.

In a preferred embodiment, silicon is used as the semiconductor material and magnesium is used as the alkaline earth element in the aluminum alloy used to produce the housing 3 according to the invention.

The alloy includes aluminum, silicon and magnesium.

In one possible embodiment, the weight percentages of the alloy are as follows:

Aluminum 91.2%-95.8%

Silicon 4%-8%

Magnesium 0.2%-0.8%.

In summary, in an exemplary embodiment of the aluminum alloy, the percentage of silicon is comprised between 4% and 8%, and the percentage of magnesium is comprised between 0.2% and 0.8%.

The aluminum alloy used to make the casing 3 according to the present invention may include one or more metal elements such as copper, manganese, titanium and zinc in combination with or in place of silicon or magnesium.

Some possible percentages by weight of each metal that can be used in one possible embodiment of the alloy are as follows:

Copper 0.8%-1.5%

Manganese 0.3%-0.75%

Titanium 0.1%-0.18%

Zinc 0.1%-0.75%

The percentages of the various components can vary depending on physical properties such as the specific gravity to be achieved. By way of non-limiting example, a reduction in silicon content will reduce the specific gravity of the alloy. Conversely, adding metals to the alloy will increase the specific gravity of the alloy.

In addition, silicon improves the casting properties of the alloy and reduces the coefficient of expansion of the alloy. Manganese increases the mechanical strength and corrosion resistance of the alloy.

In a preferred but non-limiting embodiment, the alloy comprises aluminum, silicon, magnesium and titanium in the following weight percentages relative to the weight of the alloy:

Between 91.87% and 93.1% aluminum;

Between 6.5% and 7.5% silicon;

Between 0.3% and 0.45% magnesium;

• Between 0.1% and 0.18% titanium.

The specific gravity of the alloy thus obtained was 2.66 kg/dm ³ .

In an alternative embodiment, percentages comprised between 0.1% and 1.5%, preferably between 1% and 1.5%, of copper are added.

For the purposes of the present invention, it is considered that the total impurities contained in the alloy other than iron and titanium are comprised between 0.03% and 0.2%, preferably 0.1%.

In an alternative embodiment, manganese is added in a percentage between 0.1% and 0.1%, preferably between 0.3% and 0.75%.

In an alternative embodiment, zinc is added in a percentage between 0.1% and 10%, preferably not more than 0.75%.

According to another alternative embodiment of the present invention, the aluminum alloy comprises aluminum, copper, magnesium, and silicon, and the weight percentages of these components relative to the weight of the alloy are as follows:

Between 92.35% and 94.1% aluminum;

Between 4.5% and 5.5% silicon;

Between 0.4% and 0.65% magnesium;

Between 1% and 1.5% copper.

This embodiment of the alloy has a specific gravity of 2.71 kg/dm ³ .

According to another alternative embodiment of the present invention, the aluminum alloy comprises aluminum, copper, magnesium, and silicon, and the weight percentages of these components relative to the weight of the alloy are as follows:

Between 91.62% and 92.9% aluminum;

Between 6.5% and 7.5% silicon;

Between 0.5% and 0.7% magnesium;

• Between 0.1% and 0.18% titanium.

This embodiment of the alloy has a specific gravity of 2.66 kg/dm ³ .

According to another alternative embodiment of the present invention, the aluminum alloy comprises aluminum, magnesium, silicon and manganese in the following weight percentages relative to the weight of the alloy:

Between 92.95% and 94.65% aluminum;

Between 4.2% and 5.5% silicon;

Between 0.6% and 0.8% magnesium;

Between 0.55% and 0.75% manganese.

This embodiment of the alloy has a specific gravity of 2.65 kg/dm ³ .

The aluminum alloy according to the present invention also has the following mechanical properties:

a unit breaking load comprised between 170 N/ ^mm² and 350 N/ ^mm² , preferably between 180 N/ ^mm² and 340 N/ ^mm² , more preferably between 180 N/ ^mm² and 340 N/ ^mm² ;

a yield load comprised between 90 N/ ^mm² and 350 N/ ^mm² , preferably between 220 N/ ^mm² and 280 N/ ^mm² ;

strain according to UNI specifications, the strain being comprised between 2.5% and 12%, preferably between 4% and 9%;

The Brinell hardness, determined by means of a spherical indenter, is comprised between HB=50 and HB=140, preferably between HB=80 and HB=100.

As is well known to those skilled in the art, the mechanical properties mentioned above vary depending on the alloy manufacturing process, in particular the physical state of the casting, which may be sand or chill casting, and the aging and hardening treatments to which it is subjected.

The solidification and melting range of the aluminum alloy according to the present invention is 550 degrees Celsius to 640 degrees Celsius, preferably in the range of 550 degrees Celsius to 625 degrees Celsius.

As mentioned above, the housing 3 comprises an inlet circuit 4 and an outlet circuit 5 .

The inlet circuit 4 comprises an inlet connector 41 which allows the hammer 2 to be connected to a compressed air circuit.

Said inlet connector 41 is located at a second end of the hammer 2 opposite to the end where the impactor or striker 6 is located, and at a second end of the casing 3 opposite to the end where the impactor or striker 6 is located.

Said outlet circuit 5 comprises an outlet connector 54 for connecting the hammer 2 to an air recovery circuit.

In a preferred, but non-limiting embodiment of the hammer 2 according to the invention, said outlet connector 54 is located adjacent to the inlet connector 41 at the second end of the hammer 2 .

The outlet circuit 5 comprises an outlet opening 51 formed in the cylinder 3, through which the air is discharged when the movement mechanism 7 is activated, and a discharge duct 52 extending from the outlet opening 51 upwards to the second end of the hammer 2, in particular to the second end of the housing 3. The outlet opening 51 and the discharge duct 52 are formed in the housing 3 itself, in particular in the edge of the housing 3 that delimits the inner chamber 32. In particular, the discharge duct 52 is incorporated into the housing 3 in a manner that is difficult to access.

Preferably, the discharge duct 52 is shaped so as to at least partially surround the interior 32 of the housing 3 with respect to a plane perpendicular to its longitudinal extension, so that the discharge duct 52 serves as a cooling circuit for the housing 3 and/or for the movement mechanism 7 arranged in the interior 32 of the housing 3.

In one possible embodiment, the cross section of the discharge duct 52 is shaped like a portion of a circular crown. One embodiment of the shape of the discharge duct 52 is shown in Figures 4A to 4D.

In an exemplary embodiment (not shown), the discharge duct can have a circular cross section, so that it only serves as a discharge duct, which, however, is still integrated in the housing 3 .

Preferably, the outlet circuit 5 includes a first chamber 510 for placing the outlet opening 51 in fluid communication with the exhaust pipe 52 by combining the outlet opening 51 with the exhaust pipe 52. The first chamber 510 may be a closed chamber or recess formed adjacent to the outlet opening 51, such that the first chamber 510 connects the outlet opening 51 to the exhaust pipe 52. In an exemplary and non-limiting embodiment, the first chamber is a tapered pipe portion adapted to connect the outlet opening to the exhaust pipe.

The outlet circuit 5 further comprises a discharge chamber 53 for fluidly connecting the discharge pipe 52 to the outlet connector 54. The discharge chamber allows the discharge pipe 52 to be connected to the outlet connector 54. In a preferred embodiment, the discharge chamber has at least one rounded portion that allows the outlet connector to be fastened to the outlet circuit 5, for example, by means of a threaded member. In an exemplary but non-limiting embodiment, the discharge chamber 53 is a tapered pipe portion that connects the discharge pipe to the outlet connector 54.

Said outlet connector 54 is preferably a separate element connected to a hole formed in the housing 3, for example by means of a screw thread.

FIG. 2B shows an exemplary embodiment of the movement mechanism 7 , wherein a person skilled in the art can intuitively see the flow of compressed air, which enters through the inlet circuit to move the hammer 2 and is discharged through the outlet circuit 5 .

As can be clearly seen, the compressed air fed into the inlet connector 41 enters the inlet chamber 42. Said inlet chamber has a variable volume depending on the movement of the movement mechanism 7 within the internal chamber 32 of the housing 3 between the retracted position and the working position.

When compressed air enters the air inlet chamber 42 , the compressed air exerts a thrust on the motion mechanism 7 , thereby switching the motion mechanism 7 from the retracted position toward the working position.

The compressed air is introduced into the inner chamber 722 of the cylinder 72 through an air intake duct included in the head 71, thereby causing the striking body to oscillate within the cylinder 72, as is well known to those skilled in the art.

The oscillations of the movement mechanism 7 and in particular of the striking body 73 cause the air to be directed towards the outlet circuit 5 .

In particular, there is an outlet opening 51 allowing compressed air to escape from the inner chamber 32 of the casing 3 .

The air guided by the outlet opening 51 is carried through the exhaust duct towards the air recovery circuit.

Said discharge chamber 53 is present between the outlet connector, which allows the hammer to be connected to an air recovery circuit (not shown), and the discharge duct 52 .

As mentioned above, in a preferred but non-limiting embodiment, the hammer 2 according to the invention comprises a measurement circuit 8 for measuring the vibration frequency of the movement 7 .

The measuring circuit 8 comprises at least one sensor for measuring the vibration frequency of the motion circuit 7 .

In one possible embodiment, the measuring circuit 8 is suitable for measuring the pressure inside the inner chamber 32 of the housing 3 .

In a preferred embodiment, the measuring circuit 8 is adapted to detect the sliding movement of the striking body 73 in the cylinder 72. This measurement can be performed directly by means of a position sensor or a sliding sensor. This measurement can also be performed indirectly by means of a sensor capable of detecting the pressure changes caused by the movement of the striking body 73 in the cylinder 72. A preferred embodiment employs an elongation sensor capable of detecting the deformation of the electrical conductor caused by the alternating air flow induced by the sliding movement of the striking body 73 in the cylinder 72. A possible embodiment of the measuring circuit 8 and of the method for acquiring the measurement data is described, for example, in Italian patent application RN2005A000024.

The measuring circuit 8 includes a processing circuit (not shown) and a supply line 82. The processing circuit is encapsulated in a protective shell 84 and is used to receive the electrical signal transmitted by the at least one sensor. The supply line 82 is used to conduct the electrical signal from the measuring circuit 8 and/or conduct the electrical signal to the measuring circuit 8.

The supply line 82 allows the measurement circuit 8 to be connected to an external control circuit (not shown), to which a communication line can transmit the acquired data.

The hammer according to the invention comprises a channel 37 formed in the casing 3 and opening towards the second end of the hammer 2 , in particular towards the second end of said casing 3 , and in the vicinity of the inlet connector 41 .

Said supply line 82 can be arranged in said channel 37 for keeping the entire connection of the hammer centered at the second end of the hammer. Said channel 37 is preferably incorporated in an inaccessible manner into the wall defining the interior of the casing 3 .

In the embodiment shown in the figures, the casing 3 of the hammer 2 according to the invention comprises a housing 35 formed in the outer surface of the casing 3 itself, the outer contour of which encapsulates the measuring circuit 8 , in particular the protective shell 84 .

The shape of the housing 35 is complementary to that of the outer protective shell 84 , so that the outer protective shell 84 can be accommodated in the housing 35 .

Said housing 35 has at least one fastening portion therein, which allows the measuring circuit 8 to be fastened to the hammer 2 , in particular to the casing 3 .

The measuring circuit 8 and in particular the outer protective shell 84 are fastened to the hammer by means of fasteners such as screws or bolts.

The housing 35 is formed in the portion of the cylinder 3 from which the connecting flange 36 extends.

Even more preferably, said housing 35 is formed at the initial flat portion of the connecting flange 36 where it begins to protrude from the contour of the casing 3 , as can be seen for example in FIGS. 1A , 1B , 2A , 3 and 4B .

Preferably, a channel 37 originates from the housing 35 , in which a supply line 82 for the measuring circuit 8 can be arranged.

Furthermore, at said housing 35 , the casing 3 comprises a measuring duct 34 , via which the measuring circuit 8 can carry out measurements in order to determine the vibration frequency of the movement 7 .

Said duct 34 brings the external environment into communication with the interior 32 of the housing 3. The sensors of the measuring circuit 8 are arranged in the vicinity of said measuring duct 34.

In a preferred embodiment, the sensor is positioned on the measuring pipe 34 , more preferably at a position where the channel 34 is separated from the housing 35 .

In particular, the sensor is arranged on the bottom surface of a protective shell 84 encapsulating the processing circuit, and the air jet generated by the oscillation of the striking body 73 in the cylinder 72 can act on the sensor through a suitable orifice.

The shape of the housing is complementary to the protective shell 84 of the measuring circuit 8 .

In a preferred embodiment, said housing 35 has a parallelepiped shape, said housing 35 being particularly suitable for receiving a protective shell 84 of the measuring circuit 8 which also has a parallelepiped profile.

The housing 35 is suitable for enclosing at least five sides of a protective shell 84 of the measurement circuit 8 .

In a preferred but non-limiting embodiment, said casing 3 has a generally cylindrical shape with a rhomboid cross section, as can be observed for example in Figures 4A to 4D.

The particular aluminum alloy described above provides the overall structure of the casing 3 with better stress resistance and better damping properties against undesirable vibrations.

The hammer according to the invention offers good operating characteristics due to the fact that both the pneumatic and the electrical connections are located in the rear part of the hammer, at the second end of the hammer, in particular at the second end of the casing 3 .

Since the supply line 82 , for example an electrical cable, can be connected to an extension cable by means of a connector, the measuring circuit can be installed on and removed from the hammer 2 according to the invention quickly.

Furthermore, the air outlet circuit 5 has been designed to ensure better cooling of the internal components, in particular of the movement 7 .

A particularly important aspect of the invention relates to the measuring circuit 8 and in particular to a sensor, preferably an elongation sensor, for detecting the operating frequency of the hammer 2, in particular the vibration frequency of the striking body. In the hammer 2 according to the invention, the measuring circuit 8 is arranged in a suitable housing to protect it from shocks and prevent it from falling.

The connecting flange 36 includes a plurality of holes 361 through which fasteners, such as socket head screws, can be inserted for removably fastening the hammer to the decoring machine.

The connecting flange 36 comprises a separating element 362 for separating the fastening areas. Such a separating element 362 is also shaped to abut against the heads of fasteners such as screws and bolts conforming to ISO standards.

Due to the structure and materials of the hammer or vibrator 2 according to the invention, which are specifically designed and analyzed for the stresses involved, the hammer or vibrator 2 is very effective and robust.

Reference numerals

Decoring vibrator or hammer 2

Case 3

Inner Room 32

Measuring pipe 34

Housing (sensor) 35

Connecting flange 36

Connection hole 361

Separator 362

Channels (sensor cables) 37

Inlet circuit 4

Inlet connector 41

Intake chamber 42

Exit loop 5

Exit opening 51

Room 1, 510

Discharge pipe 52

Discharge chamber 53

Outlet connector 54

Impactor or striker 6

Closure element 62

Hole 622

Bushing 64

Movement mechanism 7

Head 71

Cylinder 72

Lumen 722

Exhaust 724

Elastic element 74

Strike 73

Measuring circuit 8

Supply lines 82

Protective case 84

Claims (9)

1. A core-removing pneumatic hammer (2) for removing cores from sand-cast parts, The air hammer (2) includes: -Shell (3), the shell (3) comprising: ○Inner room (32); ○Inlet circuit (4) for compressed air intake; and ○Outlet circuit for compressed air discharge (5); - Motion mechanism (7), which is used to generate vibration motion under the action of compressed air, and the mechanism is disposed in the inner chamber (32) of the housing (3); - An impactor or striker (6), which is connected to the motion mechanism (7) for contacting the casting to be cored; The air hammer (2) is characterized in that the casing (3) is made of an alloy comprising aluminum, silicon, and magnesium, wherein: - The specific gravity of the alloy is between 2.64 kg/ ^dm³ and 2.86 kg/ ^dm³ . The weight percentage of the alloy is as follows: - Aluminum: Between 91.2% and 95.8%; - Silicon: Between 4% and 8%; - Magnesium: Between 0.2% and 0.8%. 2. The pneumatic hammer according to claim 1, wherein the aluminum alloy comprises one or more metallic elements selected from the group consisting of silicon or magnesium, combined with or replacing silicon or magnesium: ·copper; ·manganese; ·titanium; Zinc. 3. The pneumatic hammer according to claim 2, wherein the weight percentage of the metal element is: Copper content: 0.8% to 1.5%; • Manganese 0.3% to 0.75%; • Titanium 0.1% to 0.18%; Zinc 0.1% to 0.75%. 4. The pneumatic hammer according to any one of claims 1 to 3, wherein the alloy comprises: • Aluminum content between 91.87% and 93.1%; Silicon content between 6.5% and 7.5%; • Magnesium content between 0.3% and 0.45%; • Titanium content between 0.1% and 0.18%; The specific gravity of the alloy is 2.66 kg/ ^dm³ . 5. The pneumatic hammer according to any one of claims 1 to 3, wherein the alloy comprises: • Aluminum content between 91.62% and 92.9%; Silicon content between 6.5% and 7.5%; • Magnesium content between 0.5% and 0.7%; • Titanium content between 0.1% and 0.18%; The specific gravity of the alloy is 2.66 kg/ ^dm³ . 6. The pneumatic hammer according to any one of claims 1 to 3, wherein the alloy comprises: • Aluminum content between 92.35% and 94.1%; Silicon content between 4.5% and 5.5%; • Magnesium content between 0.4% and 0.65%; • Copper content between 1% and 1.5%; The specific gravity of the alloy is 2.71 kg/ ^dm³ . 7. The pneumatic hammer according to any one of claims 1 to 3, wherein the alloy comprises: • Aluminum content between 92.95% and 94.65%; Silicon content between 4.2% and 5.5%; • Magnesium content between 0.6% and 0.8%; • Manganese content between 0.55% and 0.75%; The specific gravity of the alloy is 2.65 kg/ ^dm³ . 8. The pneumatic hammer according to any one of claims 1 to 3, wherein the cylinder or the housing is manufactured as a single piece. 9. The pneumatic hammer according to claim 8, wherein the cylinder or the housing is manufactured by using die casting or cold casting processes.