EP2090405A1 - Pressurised air hammer - Google Patents

Abstract

The hammer (A) has a control body for controlling compressed air path of a compressed annular space for an impact or power stroke and a back stroke of an impact piston (1), and a sound absorber (6) with an air discharge. A valve body (4) and/or the control body are formed as a ring for opening and closing of air intakes (21, 31) for a pressurization of the piston in a cylinder (2) with compressed air in a tubular manner. The air intakes are arranged perpendicular to a movement axis (X) of the piston opposing each other in a direction in the cylinder and in a retaining or holding body (3).

Description

The invention relates to a pneumatic hammer, in particular a hand-held pneumatic hammer, consisting of a holding or gripping part, a controllable compressed air inlet valve, a cylinder with a percussion piston, a valve body or control body for compressed air path control from a pressure ring space for a stroke or stroke a return stroke of the piston and a silencer with exhaust air discharge.

For pneumatic tools, there are a variety of controls for the regular reciprocation of the percussion piston, the invention relates to hammers with air intake control via a valve body and an outlet through the stroke of the working piston. In other words: The opening and closing of the air inlet is done by a simple valve body, the air outlet is released controlled by the percussion piston itself.

An air intake control can alternatively be done by flutter control, full valve control and pipe slide control. The invention is based on the use of a flutter control, in which a valve body between two seats is tossed back and forth while alternately applied to one or the other side of the cylinder with compressed air and terminates the opposite side.

A flutter control can be performed with a ball, flap, disc or plate and annular valve body, wherein a serving for the return stroke pressure line is usually designed as a bore in the cylinder or in the cylinder wall.

State-of-the-art jackhammers can also experience problems with flutter control due to poor maintenance, inadequate compressed air quality and at low temperatures, which may make it difficult to start the hammer or lead to chattering. As further disadvantages of the conventional, in particular hand-operated hammers are their large weight, their elaborate maintenance and the high effort in the production of the same noted.

Here, the invention aims to avoid the disadvantages of the previous embodiments and has set itself the goal of creating a new concept of a pneumatic hammer, by means of which at the same time a simple and safe flutter control with favorable compressed air, a low weight of the hammer and high efficiency and ease of service are present.

This object is achieved in a jackhammer, in particular a hand-held jackhammer of the type mentioned above in that the valve body or control body for opening and closing the air inlets for pressurizing the piston with compressed air in the cylinder is designed as a tubular ring and the respective air inlets substantially are arranged perpendicular to the axis of movement of the piston in a direction opposite one another in the cylinder and in the holding or gripping body.

The advantages achieved with the invention are essentially based on the new system, wherein the components are matched to one another in an advantageous manner. On the input side, this relates to the control body for opening and closing the air inlets in cooperation with a structural design of the compressed air guide. A control body, designed as a tubular ring, is movably guided on the face side between cylinder and grip body in a valve space and has connecting means in the guide area. Of the pressurizable with compressed air annulus are opposite to each other an air inlet into the cylinder for acting on the piston for the stroke on the one hand and on the other hand, a supply line into a pipe system in the handle body, which ultimately serves for Rückhuberstellung arranged. Such a reversing device for the compressed air supply is particularly reliable and of great gas flow kinetic advantage.

A structurally particularly favorable form with high reliability and functional stability of the control body is present when the tubular valve body or control body at least on one of the end faces in Rohraxrichtung Recesses or recesses as a connecting means to the pressure ring space.

Particular advantages in terms of a lower weight of the hammer can be achieved if the cylinder for the percussion piston has a substantially axsymmetrische wall thickness free of longitudinal bores.

In this embodiment, the cylinder, or rather the cylinder wall thickness, has to be designed only according to the mechanical stress, whereby a small wall thickness and thus a weight reduction of the hammer in a favorable manner compared to the prior art is possible.

According to a most advantageous embodiment of the invention can be provided that the muffler for the exhaust air outlet with the holding or gripping body and the cylinder is in operative connection and integrated has a Druckluftleitmittel for acting on the piston for the return stroke. In this way, not only economical production and high service friendliness of the hammer is achieved, but it is also possible weight savings and improved sound insulation.

Further, when the silencer is formed of engineering polyurethane (TPU), and the connections to the holding or gripping body and to the cylinder and the connection of the Druckluftleitmittels are designed as connectors, the soundproofing can further intensified and greatly facilitates installation and / or disassembly and be carried out with high economy.

In the following, the invention will be explained in more detail with reference to drawings showing only one embodiment.

Fig. 1

einen handgeführten Presslufthammer (A) im Schnitt

Fig. 2

Schnittdarstellung ((AA) aus Fig. 1) senkrecht zur Axe im Bereich des Ventilkörpers

Fig. 3

Schnittdarstellung gem. Fig. 2 in Axrichtung

It shows:

Fig. 1

a hand-held pneumatic hammer (A) in section

Fig. 2

Sectional view ((AA) off Fig. 1 ) perpendicular to the axis in the region of the valve body

Fig. 3

Sectional view acc. Fig. 2 in the axial direction

A

Presslufthammer

1

Kolben

2

Zylinder

21

Lufteinlass in den Zylinder

3

Griffkörper

31

Lufteinlass in das Leitmittel im Griffkörper

32

Druckraum

4

Ventilkörper

41

Verbindungsmittel im Ventilkörper

5

Steckverbundteil

51

Druckluftleitmittel

6

Schalldämpfer

61

Abluftaustrag

For a simplified allocation of the parts in the figures, the following list of reference numerals serve:

A

Jackhammer

1

piston

2

cylinder

21

Air intake in the cylinder

3

handle

31

Air inlet in the guide in the handle body

32

pressure chamber

4

valve body

41

Connecting means in the valve body

5

Plug composite part

51

Druckluftleitmittel

6

silencer

61

Abluftaustrag

Fig. 1 shows a pneumatic hammer A according to the invention with resilient in the direction of impact handles for vibration reduction.

A percussion piston 1 is positioned in a cylinder 2, which cylinder 2 has a substantially axsymmetric, small wall thickness without axial bore. A cylinder 2 made of steel is economical in such an embodiment, for example, by turning and by radial drilling, can be produced and may have low weight.

With a cylinder 2 described above, a handle body 3 is connected, which has a controllable compressed air inlet valve, optionally a switchable by means of actuating means on a handle ball valve and a compressed air supply to a pressure chamber 32, formed by handle body 3 and cylinder 2.

In the cylinder 2, an air inlet 21 is formed at the end in the region of the starting position for the stroke of the piston 1 by a radial bore, which or which can be closed by a tubular valve body 4. In one with the Cylinder 2 in the associated handle body 3 is in the radial direction, after a valve body 4 a bore rectified with that 21 in the cylinder wall, so radially, continued and serves as an air inlet into a guide 31 in the handle body. 3

In the handle body 3 is carried out by an opening into the guide means 31, axial bore a diversion of compressed air for a return stroke from the piston 1, wherein in the bore a plug connection part 5 is introduced, which part 5 has a channel as Druckluftleitmittel 51.

Opposite, the composite part 5 is positioned einragend in a PTU silencer 6, in which a compressed air line to the inlets for a return stroke in the cylinder 2 is continued.

The assembly of the parts takes place essentially in a first step by inserting a cylinder 2 with inserted valve body 4 and piston 1 in a preassembled handle part 3, which is provided with a composite part 5. In the following step, securing means must be used, as well as a silencer 6 postponed and brought to a snap.

When disassembling for service work or cleaning a pneumatic hammer according to the invention can be overcome by locking means or solution of securing means in a simple way the PTU silencer 6 removed from the handle body 3 with a composite part 5 and cylinder 2 and handle body 3 are slidingly separated, so that the valve body and the Umsteuerkomponenten 21,31 exposed.

Fig. 2 is a section AA of a pneumatic hammer A according to Fig. 1 shown in principle perpendicular to the hammer length in the area of a valve control.

In the end region forms a recess in a cylinder 2 a clearance or valve space between the cylinder 2 and a handle body 3, in which valve chamber, a valve body 4 is arranged radially displaceable.

In the radial direction with the same axis 3 holes are provided in the valve chamber area as an air inlet 21 in the cylinder 2 and as an air inlet 31 in the handle body.

In a radial displacement of a valve body 4 with an outer diameter smaller than / equal to the outer diameter of the recess in the valve chamber to the handle body 3 and an inner diameter greater than / equal to the outer diameter of the cylinder 2 in the valve chamber can through this alternatively the air inlets 21 and 31 in the cylinder. 2 or be closed or opened in the handle body 3.

As Fig. 3 shows in an axially guided section in the region of the air inlets 21,31, immediately below the valve chamber and connected to this a pressure chamber 32 formed by radial recesses of the cylinder 2 and the handle body 3.

A tubular valve body 4 has in the tube alignment recesses in several places, so that in spite of stimseitigem concern to a radial partial surface of the cylinder 2 in each case a connecting means 41 is given to the pressure chamber 32, which pressure chamber 32 with a controllable compressed air supply ( Fig. 1 ).

Claims (5)

Jackhammer (A), in particular hand-guided jackhammer, consisting of a holding or gripping part, a controllable compressed air inlet valve, a cylinder with a percussion piston, a valve body or control body for compressed air path control from a pressure ring space for a stroke or working stroke and a return stroke the piston and a muffler with exhaust air discharge, characterized in that the valve body (4) or control body for opening and closing the air inlets (21,31) for acting on the piston (1) in the cylinder (2) formed with compressed air tubular as a ring is and the respective air inlets (21,31) substantially perpendicular to the axis of movement (X) of the piston (1) in a direction opposite to each other in the cylinder (2) and in the holding or handle body (3) are arranged. Jackhammer (A) according to claim 1, characterized in that the tubular valve body or control body (4) at least on one of the end faces in Rohraxrichtung recesses or recesses as connecting means (41) to the pressure ring space (32). Jackhammer (A) according to claim 1 or 2, characterized in that the cylinder (2) for the percussion piston (1) has a substantially axsymmetrische wall thickness free of longitudinal bores. Pneumatic hammers (A) according to one of claims 1 to 3, characterized in that the muffler (6) for the exhaust air discharge with the holding or handle body (3) and with the cylinder (2) is in operative connection and a Druckluftleitmittel (51) to act on the piston (1) for the return stroke. Pneumatic jack (A) according to one of claims 1 to 4, characterized in that the silencer (6) is formed from technical polyurethane (TPU), and that the connections to the holding or gripping body (3) and to the cylinder (2) as well as the connection of the Druckluftleitmittels (52) are designed as plug-in connections.

Images