EP3184247A1 - Combustion-driven setting tool and method for operating such a setting tool - Google Patents

Abstract

The invention relates to a combustion-powered setting tool (1) for driving fastening elements into a substrate, having at least one main combustion chamber (6) for a fuel, with a driving piston (10) which can be expanded via expandable gases from the main combustion chamber (6) in the setting direction (15). is drivable, and with an antechamber (25), which is associated with an ignition device (26) and in which before the ignition of a fuel-air mixture in the main combustion chamber (6) acting on the main combustion chamber (6) pressure can be built up, the prechamber (25) is connected or connectable to an environment of the prechamber (25) via at least one passage opening (31, 32), which can be closed by a control device (30). In order to improve the effectiveness and / or the functionality when driving fasteners, the control device (30) is control pressure connected to the main combustion chamber (6).

Description

Technical area

The invention relates to a combustion-powered setting tool for driving fasteners into a substrate, with at least one main combustion chamber for a fuel, with a driving piston, which is drivable by exandierbare gases from the main combustion chamber in the setting direction, and with an antechamber, which is associated with an ignition and in in front of the ignition of a fuel-air mixture in the main combustion chamber, a pressure acting on the main combustion chamber pressure is buildable, wherein the prechamber via at least one passage opening which is closable by a control device, connected to an environment of the prechamber or is connectable. The invention further relates to a method for operating such a combustion-powered setting tool.

State of the art

From the German patent application DE 10 32 035 A1 a combustion-powered setting tool for driving fasteners into a substrate is known, comprising at least one main combustion chamber for a fuel, with a piston mounted in a piston guide drive piston, which is driven by expanding gases from the main combustion chamber in the setting direction, and with a prechamber, in front of the Ignition of a fuel-air mixture in the main combustion chamber, a pressure acting on the main combustion chamber pressure is buildable, wherein the pre-chamber of a remote from the main combustion chamber bottom of the drive piston located in its initial position subsequent space is formed within the piston guide, and wherein the pre-chamber via a Passage with the main combustion chamber at least temporarily in communication, wherein in the main combustion chamber, a means for detecting the pressure is provided, which cooperates with the ignition device for the main combustion chamber.

Presentation of the invention

The object of the invention is the effectiveness and / or functionality when driving fasteners with a combustion-driven setting tool, with at least one main combustion chamber for a fuel, with a drive piston which is drivable via ex-acceptable gases from the main combustion chamber in the setting direction, and with an antechamber in which an ignition acting on the main combustion chamber pressure is buildable prior to the ignition of a fuel-air mixture in the main combustion chamber, wherein the pre-chamber via at least one passage opening which is closable by a control device, with an environment of the prechamber connected or connectable, to improve.

The object is with a combustion-powered setting tool for driving fasteners into a substrate, with at least one main combustion chamber for a fuel, with a driving piston which is drivable via exandierbare gases from the main combustion chamber in the setting direction, and with an antechamber, which is associated with an ignition and in which prior to the ignition of a fuel-air mixture in the main combustion chamber, a pressure acting on the main combustion chamber pressure is buildable, the prechamber via at least one passage opening which is closed by a control device, connected to an environment of the pre-chamber or connected, thereby achieved in that the control device is connected in terms of pressure with the main combustion chamber. Due to the control pressure connection, the control device is actuated during operation of the setting device with the main combustion chamber pressure. When the pressure in the main combustion chamber reaches a certain pressure level, then the at least one passage opening of the antechamber is automatically opened. The pilot pressure connection can be realized in various ways.

A preferred embodiment of the combustion-powered setting tool is characterized in that the control device has at least one control pressure surface, which is acted upon by the main combustion chamber pressure. This provides the advantage that no additional sensor means is needed to detect the main combustion chamber pressure. In addition, the main combustion chamber pressure acting on the control pressure surface, for example via a suitable mechanical coupling, can be used directly to control or effect the opening or releasing and closing of the passage opening of the prechamber.

A further preferred embodiment of the combustion-powered setting tool is characterized in that the control pressure surface of the control device is mechanically coupled to a control sleeve. The control sleeve has, for example, substantially the shape of a straight circular cylinder jacket, which relative to a housing or a cylinder which delimits the antechamber, between an open position in which the passage opening of the antechamber is released or opened, and a closed position, in which the passage opening of the pre-chamber is released, is movable.

A further preferred embodiment of the combustion-powered setting tool is characterized in that the control sleeve is designed and movable relative to the passage opening of the antechamber, that the passage opening of the pre-chamber is released or closed in dependence on the main combustion chamber pressure of the control sleeve. The movement of the control sleeve is advantageously controlled by the main combustion chamber pressure, which acts on the control pressure surface. The movement of the control sleeve between the open position and the closed position is made possible, for example, by a guide of the control sleeve on the housing or the cylinder which delimits the antechamber.

A further preferred embodiment of the combustion-powered setting tool is characterized in that the control pressure surface is mechanically coupled to the control sleeve via a coupling element. The coupling element is, for example, a kind of slider. At one of the main combustion chamber facing the end of the slide is advantageously formed the control pressure surface. At one end of the slide remote from the main combustion chamber, the slide is advantageously coupled to the control sleeve. The slider is advantageously used to transmit a pressure force generated by acting on the control pressure surface main combustion chamber pressure on the control sleeve.

Another preferred embodiment of the combustion-powered setting tool is characterized in that the control pressure surface via at least one spring device is supported on a housing-fixed stop. The housing-fixed stopper is mounted, for example, in the housing or the cylinder which limits the antechamber. By the spring means, the control pressure surface, in particular together with the control sleeve, biased in a closed position, in which the passage opening of the antechamber is closed by the control sleeve.

Another preferred embodiment of the combustion-powered setting tool is characterized in that the control pressure surface is designed as an annular surface and is arranged radially outside a piston guide space. In the piston guide space, the driving piston is guided to and fro movable. In this case, the driving piston can be guided directly in the piston guide chamber. But it is also possible to guide a piston rod or a piston plunger of the drive piston in an additional piston guide within the piston guide chamber. Depending on the design, the piston guide chamber coincides with the prechamber.

A further preferred embodiment of the combustion-powered setting tool is characterized in that the main combustion chamber is associated with a further ignition device. The setting device described above can be operated with only one ignition device, which is assigned to the antechamber. After ignition in the prechamber, reaction gases from the prechamber spread into the main combustion chamber with a progressing flame front. About the propagating into the main combustion chamber flame front then takes place in the main combustion chamber, the ignition of a precompressed air-fuel mixture contained there. The ignition of the fuel-air mixture in the main combustion chamber can also take place via the further ignition device in the main combustion chamber.

In a method for operating a combustion-operated setting tool described above, the above-mentioned object is alternatively or additionally achieved in that the control of the passage opening of the antechamber is effected by the main combustion chamber pressure. This can be realized in a simple manner, a combustion-powered or gas-powered setting tool, which has a much higher energy density. By the measures described above, the control of a venting of the pre-chamber can be realized particularly easily. In this case, an undesirable wear during operation of the setting device can be reduced particularly advantageous. In addition, by controlling the passage opening of the antechamber through the Main combustion chamber pressure a significantly increased life of the setting device can be ensured.

The invention further relates to a control device, in particular a control sleeve and / or a coupling element, for a previously described setting tool. The parts mentioned may be traded separately.

Figur 1

eine vereinfachte Darstellung eines brennkraftbetriebenen Setzgeräts mit einer Steuereinrichtung nach einer Zündung in einer Vorkammer im Längsschnitt;

Figur 2

das Setzgerät aus Figur 1 kurz nach einer Zündung in einer Hauptbrennkammer;

Figur 3

das Setzgerät aus den Figuren 1 und 2 kurz nach der Zündung in der Hauptbrennkammer mit geöffneten Durchtrittsöffnungen der Vorkammer zum Entlüften;

Figur 4

das Setzgerät aus den Figuren 1 bis 3 mit einem Treibkolben in einem unteren Totpunkt;

Figur 5

das Setzgerät aus den Figuren 1 bis 4 mit dem Treibkolben im unteren Totpunkt mit einer geschlossenen Steuerhülse;

Figur 6

das Setzgerät aus Figur 1 gemäß einem weiteren Ausführungsbeispiel mit einer weiteren Zündeinrichtung, die der Hauptbrennkammer zugeordnet ist und

Figur 7

teilweise ein brennkraftbetriebenes Setzgerät mit einer Steuereinrichtung nach einer Zündung in einer Vorkammer im Längsschnitt.

Further advantages, features and details of the invention will become apparent from the following description in which, with reference to the drawings, various embodiments are described in detail. Show it:

FIG. 1

a simplified representation of a combustion-powered setting device with a control device after ignition in an antechamber in longitudinal section;

FIG. 2

the setting tool off FIG. 1 shortly after ignition in a main combustion chamber;

FIG. 3

the setting tool from the FIGS. 1 and 2 shortly after the ignition in the main combustion chamber with open passage openings of the pre-chamber for venting;

FIG. 4

the setting tool from the FIGS. 1 to 3 with a driving piston in a bottom dead center;

FIG. 5

the setting tool from the FIGS. 1 to 4 with the drive piston in bottom dead center with a closed control sleeve;

FIG. 6

the setting tool off FIG. 1 according to a further embodiment with a further ignition device which is associated with the main combustion chamber and

FIG. 7

partly a combustion-powered setting tool with a control device after ignition in an antechamber in longitudinal section.

embodiments

In the FIGS. 1 to 5 is a setting tool 1 greatly simplified in a longitudinal section shown in various operating conditions. That in the FIGS. 1 to 5 Setting device 1 shown can be operated with a fuel gas or with a vaporizable liquid fuel. The setting device 1 comprises a housing 3 with a master cylinder 5, the a main combustion chamber 6 limited. The main combustion chamber 6 can be supplied via an inlet device 8 gas and / or air.

In the housing 3 of the setting device 1 is a driving piston 10 in the FIGS. 1 to 5 moved back and forth down and up. The driving piston 10 comprises a piston rod 11, which starts from a piston head 12. A facing away from the piston head 12 setting end 14 of the piston rod 11 is arranged in a (not shown) bolt guide, which serves to guide fasteners, which are also referred to as bolts. In the Figures 3 . 4 . 5 the setting end 14 of the piston rod 11 of the drive piston 10 is shown cut off.

The bolt guide with the piston rod 11 of the drive piston 10 disposed therein is also referred to as a setter. About the network, a fastener, such as a nail, bolts or the like, are driven into a (not shown) underground. Before setting a fastener, the setting tool 1 is pressed with his pin guide to the ground and triggered. To trigger a setting process, for example, a switch (not shown) is used, which is also called a trigger switch. The switch is provided, for example, on a (also not shown) handle of the setting device 1.

By an arrow 15 is in the FIGS. 1 to 5 a setting direction indicated. When setting a fastener of the driving piston 10 is strongly accelerated with the piston rod 11 in the setting direction 15 to drive the fastener into the ground. During the setting process, the driving piston 10 is out of his in FIG. 1 shown starting position, which corresponds to a top dead center, moved to an end position, for example, in FIG. 4 is shown and corresponds to a bottom dead center.

A movement of the driving piston 10 in the FIGS. 1 to 5 upwards is limited by a housing-fixed piston stop 16. By the piston stop 16, the top dead center of the driving piston 10 is defined. The piston stop 16 may be combined with a magnetic device 17. The magnetic device 17 serves, for example, the driving piston 10 with a predetermined holding force in his in FIG. 1 to keep the initial position shown. A movement of the driving piston 10 down is limited by stop and / or damping elements 28, 29. The stop and / or damping elements 28 are designed, for example, as a buffer.

The piston head 12 comprises a first piston surface 21, which faces the main combustion chamber 6. A second piston surface 22, which faces away from the main combustion chamber 6, delimits an antechamber 25 in a prechamber cylinder 24. The prechamber cylinder 24 is part of the housing 3 of the setting device 1 or rigidly connected to the housing 3.

The prechamber 25 represents a pre-combustion chamber to which an ignition device 26 and an inlet device 27 are assigned. In addition, the stop and / or damping elements 28, 29 are arranged in the antechamber 25. About the inlet means 27 of the pre-chamber or pre-combustion chamber 25, a fuel gas-air mixture is supplied, which is ignited by means of the ignition device 26 in the prechamber 25, as in FIG. 1 is indicated by a symbol 60.

The pre-chamber cylinder 24 comprises two passage openings 31, 32, which allow, for example, the exit of exhaust gases from the pre-chamber 25. The passage openings 31, 32 can be closed by a control device 30 as needed. The control device 30 comprises a control sleeve 34, which has two passage openings 37, 38. If the passage openings 37, 38 of the control sleeve 34 are brought into register with the passage openings 31, 32, then the passage openings 31, 32, as can be seen in the Figures 2 . 3 . 4 sees, open. In the FIGS. 1 and 5 the passage openings 31, 32 are closed by the control sleeve 34. The control sleeve 34 has substantially the shape of a straight circular cylinder jacket and is in the FIGS. 1 to 5 movable downwards and upwards.

Between the prechamber 25 and the main combustion chamber 6, two overflow openings 41, 42 are provided. The overflow openings 41, 42 are each assigned a valve device 43, 44. The valve devices 43, 44 are, for example, valve flaps which are in FIG. 1 are opened to allow passage of the ignited air-fuel mixture from the antechamber 25 in the main combustion chamber 6. In the FIGS. 2 to 5 the valve means 43, 44 are closed.

The control device 30 comprises a control pressure surface 45, which is connected in terms of pressure with the main combustion chamber 6. The control pressure surface 45 is designed as an annular surface 46, which faces radially outside of the prechamber cylinder 24 of the main combustion chamber 6. The control pressure surface 45 is mechanically connected via a coupling element 48 the control sleeve 34 is coupled. The coupling element 48 is designed as a slider 50, which in the FIGS. 1 to 5 down and up and forth to and fro is guided on the pre-chamber cylinder 24. At one in the FIGS. 1 to 5 Upper end 51 of the slider 50 is designed as an annular surface 46 control pressure surface 45 is provided. At one in the FIGS. 1 to 5 lower end 52 of the slider 50, the control sleeve 34 is attached.

The control device 30 further comprises spring devices 54, 55, which are designed, for example, as helical compression springs. The in the FIGS. 1 to 5 lower ends of the spring means 54, 55 are each a fixed housing stop 56, 57 assigned. The housing-fixed stops 56, 57 are provided on the prechamber cylinder 24. The spring devices 54, 55 are clamped between the housing-fixed stops 56, 57 and the upper end 51 of the slider 50 with the control pressure surface 45. Thus, the slider 50 via the spring means 54, 55 supported on the housing-fixed stops 56, 57.

In FIG. 1 the setting tool 1 is shown shortly after the ignition 60 in the pre-chamber 25. The arrows 61, 62 indicate that the ignited mixture passes through the open valve devices 43, 44 through the overflow openings 41, 42 into the main combustion chamber 6. The passage openings 31, 32 of the prechamber 25 are closed by the control sleeve 34.

In FIG. 2 the setting tool 1 is shown shortly after ignition in the main combustion chamber 6. The ignition in the main combustion chamber 6 is indicated by a symbol 65. The ignition 65 in the main combustion chamber 6 is triggered for example via a (not shown) flame front from the pre-chamber 25. Due to the increased pressure in the main combustion chamber 6, the valve devices 43, 44 close. At the same time, the control device 30 opens the passage openings 31, 32 so that exhaust gas can escape from the pre-chamber 25.

The release of the passage openings 31, 32 of the pre-chamber 25 through the control sleeve 34 is triggered by the increased pressure in the main combustion chamber 6, which acts on the control pressure surface 45 and is transmitted via the slider 50 to the control sleeve 34. By a movement of the control sleeve 34 in FIG. 2 down are the Passage openings 37, 38 of the control sleeve 34 with the passage openings 31, 32 brought in the antechamber cylinder 24 to cover.

In FIG. 3 the setting tool 1 is shown shortly after the ignition 65 in the main combustion chamber 6. The main combustion chamber 6 is shortened referred to as the main chamber 6. By arrows 66 and 67 is in FIG. 3 indicated that the increased pressure in or out of the main combustion chamber 6 acts on the in the main combustion chamber 6 facing the first piston surface 21 of the driving piston 10, whereby this in FIG. 3 is moved in the setting direction 15 down. By arrows 68 and 69 is indicated that during the movement of the driving piston 10 in the setting direction 15 down exhaust from the antechamber 25 through the opened passage openings 31, 32 exits.

In FIG. 4 the drive piston 10 is shown in its bottom dead center. The piston head 12 of the drive piston 10 comes to rest on the stop and / or damping elements 28, 29. At bottom dead center of the piston head 12 of the drive piston 10 in FIG. 4 below the opened passage openings 31, 32 of the pre-chamber 25 is arranged. Arrows 71, 72 indicate that exhaust gases or hot gases escape from the main combustion chamber 6 via the opened passage openings 31, 32.

In FIG. 5 the drive piston 10 is still in its bottom dead center. When the hot gases escape, the pressure in the main combustion chamber or main chamber 6 drops. The falling pressure in the main combustion chamber 6, together with the spring force of the spring devices 54, 55 of the control device 30, causes the control sleeve 34 to close the passage openings 31, 32 in the prechamber cylinder 24. The return of the drive piston 10 is thermally (not shown) in the connection by the cooling of the hot gases in the main combustion chamber 6, wherein a negative pressure in the main combustion chamber is formed.

In FIG. 6 is a similar combustion-powered setting device 74 as in the FIGS. 1 to 5 shown. The setting device 74 differs from that in the FIGS. 1 to 5 Setting device 1 shown, the main combustion chamber 6 is additionally associated with a valve device 75 and a further ignition device 76.

The valve device 75 makes it possible to vent the main combustion chamber 6, for example for flushing purposes. About the further ignition device 76, a gas mixture in the Main combustion chamber 6 are ignited regardless of whether an ignition in the antechamber 25 has already taken place. As a result, further operating modes of the setting device 74 are made possible. Otherwise, the setting tool 74 differs in FIG. 6 not of that in the FIGS. 1 to 5 illustrated setting device 1.

In FIG. 7 is a setting device 101 as a further embodiment partially shown, which is operated with a fuel gas or with a vaporizable liquid fuel. The setting device 101 comprises a master cylinder 105 which is rigidly connected to various elements which are shown with the same hatching as the master cylinder 105. In the master cylinder 105, a driving piston 110 is reciprocally movable downwardly and upwardly in a setting direction 115 , The drive piston 110 comprises a piston rod 111, which starts from a piston head 112.

When setting a fastener of the drive piston 110 with the piston rod 111, starting from the in FIG. 7 illustrated starting position, in the setting direction 115 greatly accelerated to drive a non-illustrated fastener in a likewise not shown substrate. A downward movement of the drive piston 110 is damped by a buffer 128. A piston stop 116 for limiting the travel of the drive piston 110 upwards has a magnetic device 117, which the drive piston 110 with a predetermined holding force in his in FIG. 7 illustrated initial position holds.

A main combustion chamber 106 is essentially delimited by the piston head 112 (in the setting direction 115), a rear wall plate 170 (counter to the setting direction 115) and by a combustion chamber sleeve 180 (transverse to the setting direction 115). The main combustion chamber 106 can be flushed by moving the combustion sleeve 180 relative to the master cylinder 105 and the rear wall plate 170 in the direction of setting 115 with fresh air. In FIG. 7 a closed position of the combustion chamber sleeve 180 is shown, in which the annular scavenging ports are closed and sealed by means of sealing rings 171, 172. A fan 173 driven by a fan motor 174 serves for fresh air purging as well as turbulence or turbulence generation within the main combustion chamber 106.

An antechamber 125 is essentially delimited by the piston head 112 (counter to the setting direction 115), an unillustrated end wall of the master cylinder 105 (in the setting direction 115) and by the master cylinder 105 (transverse to the setting direction 115).

The pre-chamber 125 represents a pre-combustion chamber, which is associated with an ignition device, not shown, and also not shown inlet device for fuel. In addition, the buffer is disposed in the prechamber 125.

The master cylinder 105 comprises two passage openings 131, 132, which allow, for example, the exit of exhaust gases from the antechamber 125. The passage openings 131, 132 can be closed by a control device 130 as needed. The control device 130 comprises a control sleeve 134 which has two passage openings 137, 138. When the passage openings 137, 138 of the control sleeve 134 are brought into register with the passage openings 131, 132, the passage openings 131, 132 are opened. In FIG. 7 the passage openings 131, 132 are closed by the control sleeve 134. The control sleeve 134 has substantially the shape of a straight circular cylinder jacket and is in FIG. 7 movable downwards and upwards.

Between the pre-chamber 125 and the main combustion chamber 106, two, not shown, provided with valve means overflow openings are provided to allow passage of the ignited air-fuel mixture from the prechamber 125 into the main combustion chamber 106.

The control device 130 comprises a control pressure surface 145, which is pressure-controlled connected to the main combustion chamber 106. The control pressure surface 145 is designed as an annular surface, which faces within the master cylinder 105 by means of one or more bores 175 in the master cylinder 105 of the main combustion chamber 106 and is exposed to an overpressure in the main combustion chamber 106. The control pressure surface 145 is coupled mechanically via coupling element 148, in particular rigidly with the control sleeve 134. The control pressure surface 145 and the bores 175 are arranged radially inside the combustion chamber sleeve and in particular of the sealing ring 171.

The control device 30 further comprises, not shown, spring means for biasing the control sleeve 134 and the control pressure surface 145 in the respective in FIG. 7 shown position.

The mode of operation of the control device 130 essentially corresponds to the mode of operation of the control device 30 of the first embodiment ( FIGS. 1 to 5 ).

Claims (10)

Internal combustion setting device (1; 74) for driving fastening elements into a substrate, having at least one main combustion chamber (6) for a fuel, with a driving piston (10) which can be driven via expandable gases from the main combustion chamber (6) in the setting direction (15) , and with an antechamber (25), which is associated with an ignition device (26) and in which prior to the ignition of a fuel-air mixture in the main combustion chamber (6), a pressure acting on the main combustion chamber (6) pressure is buildable, the prechamber (25) via at least one passage opening (31,32) which is closed by a control device (30), connected to an environment of the pre-chamber (25) or connectable, characterized in that the control device (30) in terms of pressure control with the main combustion chamber ( 6) is connected. Internal combustion setting device according to claim 1, characterized in that the control device (30) has at least one control pressure surface (45), which is acted upon by the main combustion chamber pressure. Internal combustion setting device according to claim 2, characterized in that the control pressure surface (45) of the control device (30) is mechanically coupled to a control sleeve (34). Internal combustion setting device according to claim 3, characterized in that the control sleeve (34) designed and movable relative to the passage opening (31,32) of the prechamber (25), that the passage opening (31,32) of the prechamber (25) in dependence is released or closed by the main combustion chamber pressure from the control sleeve (34). Internal combustion setting device according to claim 3 or 4, characterized in that the control pressure surface (45) via a coupling element (48) is mechanically coupled to the control sleeve (34). Internal combustion setting device according to one of claims 2 to 5, characterized in that the control pressure surface (45) via at least one spring means (54,55) on a housing-fixed stop (56,57) is supported. Internal combustion setting device according to one of claims 2 to 6, characterized in that the control pressure surface (45) designed as an annular surface (46) and is arranged radially outside of a piston guide space. Internal combustion setting device according to one of the preceding claims, characterized in that the main combustion chamber (6) is associated with a further ignition device (76). Method for operating a combustion-powered setting device (1; 74) according to one of the preceding claims, characterized in that the control of the passage opening (31, 32) of the prechamber (25) is effected by the main combustion chamber pressure. Control device (30), in particular control sleeve (34) and / or coupling element (48), for a setting device (1; 71) according to one of the preceding claims.

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