EP3184255A1 - 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 a 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.

In order to improve the effectiveness and / or functionality when driving fasteners, the drive piston (10) is associated with a detection device (180), which is connected to an electronic control (184) to a starting position of the drive piston (10) before a To record settlement.

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 via expandable gases from the main combustion chamber in a setting direction, and with an antechamber, which is associated with an ignition device and in which a pressure acting on the main combustion chamber pressure before the ignition of a fuel-air mixture in the main combustion chamber is buildable.

State of the art

From the German patent application DE 42 43 36 17 A1 is a portable, combustion-powered equipment, in particular a setting device for fasteners known, with a cylindrical combustion chamber for combustion of an air-fuel mixture, whereby a plunger is driven by a piston guided through the combustion chamber cylinder, wherein a remote from the combustion chamber bottom surface of the piston in Compound pre-chamber is provided, in which an ignition-induced combustion process of an air-fuel mixture can be triggered for substantially isentropic compression of the air-fuel mixture in the combustion chamber.

Presentation of the invention

The object of the invention is the effectiveness and / or functionality in driving fasteners with a combustion-powered setting tool, with at least one main combustion chamber for a fuel, with a driving piston, which is driven via expandable gases from the main combustion chamber in a setting direction, and with a Prechamber, which is associated with an ignition device and in which a force acting on the main combustion chamber pressure before the ignition of a fuel-air mixture in the main combustion chamber can be built 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 can be driven via expandable gases from the main combustion chamber in a setting direction, and with an antechamber, which is associated with an ignition device 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 can be built up, solved in that the driving piston is associated with a detection device, which is connected to an electronic control system to control a starting position of the driving piston to record a settlement. With the aid of the detection device, a faulty state of the drive piston can be detected in a simple manner, if the drive piston is not exactly in a defined starting position. The control connection between the detection device and the electronic control allows the transmission of sensor signals and / or control signals. The control connection may optionally be wireless. With the aid of the electronic control, an injection quantity can be adjusted during operation of the combustion-powered setting device according to a current position or a piston level or piston malfunction of the driving piston.

A preferred embodiment of the combustion-powered setting tool is characterized in that the detection means associated with the driving piston comprises a piston end position sensor. The piston end position sensor can be arranged in the region of a setting end of the setting device, that is to say on a so-called tool tip. However, the piston end sensor can also be arranged in the region of a magnetic device, which serves to represent a magnetic retention for the driving piston. The detection device can also comprise a piston travel sensor at the setting end or in the tool tip of the setting device.

Another preferred embodiment of the combustion-powered setting tool is characterized in that the piston end sensor comprises a proximity switch, a contact switch and / or an inductive switch. Depending on the design, an existing piston end position sensor can also be used in the setting device in order to together with the help of the electronic control to adjust the dosage in the operation of the setting device.

A further preferred embodiment of the combustion-powered setting tool is characterized in that the detection means associated with the driving piston comprises a piston position sensor. The piston position sensor provides the advantage that it can be used to detect the current position of the driving piston regardless of whether the driving piston is near one of its end positions or far away. The piston position sensor does not necessarily have to be able to detect the entire piston displacement path. It may be sufficient to detect critical positions of the piston.

A further preferred embodiment of the combustion-powered setting tool is characterized in that the piston position sensor comprises a Hall sensor, the grooves are assigned to the driving piston. The grooves are preferably provided on a piston rod of the drive piston, which starts from a piston head or piston head of the drive piston. The Hall sensor is preferably arranged in the region of the setting end or in the tool tip of the setting end.

A further preferred embodiment of the combustion-powered setting tool is characterized in that the control device comprises a control device, via which the set energy is determined from a differential pressure between the main combustion chamber and an ambient pressure. The pre-chamber comprises at least one passage opening which can be closed by the control device. The pre-chamber can be connected to the environment via the opened passage opening. In addition, 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.

A further preferred embodiment of the combustion-powered setting tool is characterized in that the electronic control is connected in terms of control with a sensor device for detecting environmental conditions of the setting device. The sensor device comprises, for example, a temperature sensor, a Pressure sensor, an acceleration sensor, a speed sensor and / or a sensor for detecting a height in which the bolt gun is currently located.

In a method for operating a combustion-operated setting tool described above, the above-mentioned object is alternatively or additionally achieved by controlling an injection quantity of fuel gas into the pre-chamber and / or into the main combustion chamber as a function of the starting position of the drive piston. If a piston malfunction of the driving piston detected with the aid of the detection device is small enough, that is to say if the piston malfunction does not exceed a predefined limit value in order to operate the setting device in the usual manner, then normal injection is effected into the pre-chamber and into the main combustion chamber , Although the piston malfunction of the drive piston detected by the detection device is small enough to operate the setting device in the usual manner, but exceeds a critical limit, then the injection quantity in at least one of the chambers, ie the prechamber and / or the main combustion chamber , customized.

A further preferred embodiment of the method is characterized in that fuel gas is injected and ignited only in the main combustion chamber, if a piston malfunction exceeds a predetermined limit. If it is detected with the aid of the detection device that a piston malfunction of the drive piston is too large, then an appropriate amount of gas is injected only in the main combustion chamber. Then it is not injected into the prechamber. After injection, the fuel-air mixture in the main combustion chamber is ignited to perform a low energy setting. The setting with the low energy is used advantageously to return the driving piston back into a defined starting position, for example by means of thermal piston return, in which the cooling of the fuel gas after settling creates a negative pressure, which retracts the piston. Thereafter, a normal setting operation can be performed.

An alternative embodiment of the method is characterized in that fuel gas is injected and ignited only in the pre-chamber, if a piston malfunction exceeds a predetermined limit. If it is detected with the aid of the detection device that a piston malfunction of the drive piston is too large, then an appropriate amount of gas is injected only in the antechamber. Then is not injected into the main combustion chamber. After injection, the fuel-air mixture in the pre-chamber is ignited to return the driving piston back to a defined starting position. Thereafter, a normal setting operation can be performed.

An alternative embodiment of the method is characterized in that fuel gas is injected into the pre-chamber and into the main combustion chamber and ignited with a time difference, wherein the time difference is calculated on the basis of sensor signals. Thereafter, a normal setting operation can be performed.

The invention also relates to a computer program product with a program code for performing a method described above, in particular when the program is executed in the control of the setting device.

• Figur 1 ein brennkraftbetriebenes Bolzensetzgerät in einem nicht angepressten Ausgangszustand bei einer Spülung einer Hauptbrennkammer in der Draufsicht;
• Figur 2 das Bolzensetzgerät aus Figur 1 im Längsschnitt;
• Figur 3 das Bolzensetzgerät aus den Figuren 1 und 2 in einem angepressten Zustand mit geschlossener Hauptbrennkammer in der Draufsicht;
• Figur 4 das Bolzensetzgerät aus Figur 3 im Längsschnitt;
• Figur 5 das Bolzensetzgerät aus den Figuren 3 und 4 in einer perspektivischen Darstellung;
• Figur 6 das Bolzensetzgerät aus den Figuren 1 bis 5 bei einer Zündung in der Hauptbrennkammer im Längsschnitt mit geöffneten Entlüftungsverbindungen;
• Figur 7 das Bolzensetzgerät aus den Figuren 1 bis 6 im Längsschnitt bei einer thermischen Rückführung eines Treibkolbens mit geschlossenen Entlüftungsverbindungen;
• Figur 8 eine perspektivische Darstellung einer Steuereinrichtung des Bolzensetzgeräts aus den Figuren 1 bis 6;
• Figur 9 die Steuereinrichtung aus Figur 8 in der Draufsicht;
• Figur 10 eine perspektivische Darstellung einer Rückschlagventileinrichtung, welche in die Steuereinrichtung der Figuren 8 und 9 integriert ist;
• Figur 11 eine perspektivische Darstellung der Steuereinrichtung aus den Figuren 8 und 9 ohne die Rückschlagventileinrichtung, die in Figur 10 alleine dargestellt ist, und
• Figur 12 die gleiche Darstellung wie in Figur 2 mit einer dem Treibkolben zugeordneten Detektionseinrichtung zur Dosiermengenanpassung.

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 combustion-powered bolt setting device in a non-pressed initial state at a flushing of a main combustion chamber in plan view;
• FIG. 2 the bolt gun off FIG. 1 in longitudinal section;
• FIG. 3 the bolt gun from the FIGS. 1 and 2 in a pressed state with the main combustion chamber closed in plan view;
• FIG. 4 the bolt gun off FIG. 3 in longitudinal section;
• FIG. 5 the bolt gun from the Figures 3 and 4 in a perspective view;
• FIG. 6 the bolt gun from the FIGS. 1 to 5 in an ignition in the main combustion chamber in longitudinal section with open vent connections;
• FIG. 7 the bolt gun from the FIGS. 1 to 6 in longitudinal section in a thermal recycling of a drive piston with closed vent connections;
• FIG. 8 a perspective view of a control device of the bolt setting from the FIGS. 1 to 6 ;
• FIG. 9 the controller off FIG. 8 in the plan view;
• FIG. 10 a perspective view of a check valve device which in the control device of FIGS. 8 and 9 is integrated;
• FIG. 11 a perspective view of the control device of the FIGS. 8 and 9 without the check valve device which is in FIG. 10 is shown alone, and
• FIG. 12 the same representation as in FIG. 2 with a drive piston associated with the detection device for Dosiermengenanpassung.

embodiments

In the FIGS. 1 to 7 is a setting device 1 greatly simplified in a longitudinal section in various operating conditions and views shown. That in the FIGS. 1 to 7 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, which limits a main combustion chamber 6. The main combustion chamber 6 can be supplied via an inlet device 8 gas and / or air. In addition, the main combustion chamber 6 is assigned an ignition device 9.

In the housing 3 of the setting device 1 is a driving piston 10 in the FIGS. 1 to 7 guided back and forth. The driving piston 10 comprises a piston rod 11, which starts from a piston head 12. A the piston head or piston plate 12 facing away from setting 14 of the piston rod 11 is arranged in a bolt guide, which serves to guide fasteners, which are also referred to as bolts. In FIG. 7 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 7 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 illustrated initial position corresponding to an upper or rear dead center, moved to an end position corresponding to a lower or front dead center.

A movement of the driving piston 10 in the FIGS. 1 to 7 to the right 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 to the left is limited by stop and / or damping elements 28, 29. The stop and / or damping elements 28 represent a buffer 110.

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 an antechamber cylinder 24.

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 device 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 pre-chamber 25.

The pre-chamber cylinder 24 comprises 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, the passage openings 37, 38 has.

If the passage openings 37, 38 of the control sleeve 34 are brought into coincidence with the passage openings 31, 32, then the passage openings 31, 32, as can be seen in FIG FIG. 6 sees, open. In the FIGS. 1 to 5 and 7 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 FIG. 11 shown in detail.

Between the antechamber 25 and the main combustion chamber 6 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 allow passage of a ignited air-fuel mixture from the prechamber 25 into the main combustion chamber 6.

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 coupled to the control sleeve 34 via a coupling element 48.

The coupling element 48 is designed as a slider 50, which in the FIGS. 1 to 7 in the horizontal direction movable back and forth on the antechamber cylinder 24 is guided. At one in the FIGS. 1 to 7 right 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 7 left 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 7 Left ends of the spring means 54, 55 is associated with a housing fixed stop 56, 57 respectively. 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 right 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 the FIGS. 1 and 2 the bolt gun 1 is shown in a non-pressed state. Not pressed state means that the setting end 14 of the drive piston 10 is not acted upon by a bolt or a fastener with a compressive force which is to be driven into a subsoil. When pressing the bolt setting tool 1 is pressed with a tool tip of the bolt setting tool 1 against the ground.

The main combustion chamber 6 is bounded by a combustion chamber sleeve 84 which is displaceable in the axial direction limited to allow flushing of the main combustion chamber 6. In the main combustion chamber 6, a fan 80 is arranged.

In FIG. 2 is the position of the combustion chamber sleeve 84 so that the fan 80 indicated by arrows air flow 81, 82 of the rear of the device, ie the in FIG. 2 right side, generated by the main combustion chamber 6 in the environment. By the air flow 81, 82 exhaust gases are transported out of the main combustion chamber 6 after a setting process. In addition, the air flow 81, 82 ensures cooling of the main combustion chamber 6.

In the FIGS. 3 to 6 the bolt gun 1 is shown in the pressed state. In the pressed state, the setting end 14, which is also referred to as a tool tip, is pressed against a fastening element. By the pressing movement, the combustion chamber sleeve 84 to the rear, ie in FIG. 4 to the right, moved, as in FIG. 4 is indicated by an arrow 83. By the movement 83 of the combustion chamber sleeve 84 to the rear, the main combustion chamber 6 is closed from the environment.

In the following, fuel gas is injected via the inlet device 27 into the prechamber 25 and via the inlet device 8 into the main combustion chamber 6. When injecting the fuel gas into the prechamber 25 and into the main combustion chamber 6, the fan 80 rotates in the main combustion chamber 6.

The ignition of the gas mixture is initiated by the ignition device 26 associated with the pre-chamber 25 in the vicinity of the buffer 110. After the ignition of the gas mixture in the pre-chamber 25, a laminar flame front spreads, which migrates from the side of the buffer 110 in the direction of the main combustion chamber 6, ie in FIG. 4 to the right. In this case, the propagating laminar flame front pushes unburned air / fuel mixture into the main combustion chamber 6 at a high pressure.

The overflow from the pre-chamber 25 in the main combustion chamber 6 via the overflow openings 41, 42 with open valve means 43, 44th Die Valve means 43, 44 are, for example, designed as check valves which release the overflow openings 41, 42, which are also referred to as overflow openings, during spreading of the laminar flame front.

When the flame front has reached the check valves of the valve means 43, 44, the flame can over-ignite via the check valves in the main combustion chamber 6, whereby the main chamber combustion is introduced into the main combustion chamber 6. In FIG. 6 is indicated by a symbol 86, the main chamber ignition in the main combustion chamber 6.

In the main chamber ignition 86, the pressure in the main combustion chamber 6 increases and the control sleeve 34 is against the force of the spring means 54, 55, which are supported on the housing-fixed stops 56, 57, moved forward, ie in FIG. 6 to the left, as indicated by arrows 87, 88. By the movement 87, 88 of the control sleeve 34 forward two pressure relief connections 108, 109 of the pre-chamber 25 are opened.

The prechamber pressure escaping from the prechamber 25 via the opened vent connections 108, 109 is in FIG. 6 indicated by arrows 91 to 94. The pressure relief connections 108, 109 are also referred to as exhaust ports. Via the pressure relief connections or exhaust openings 108, 109, the pre-chamber pressure at the main chamber ignition 86 can escape. The driving piston 10 sets in the main chamber ignition 86 at high speed in motion and executes a settlement.

In FIG. 7 the bolt setting device 1 is shown in a longitudinal return at a thermal return of the drive piston 10. After the driving piston 10 reached the lower or front piston turning point on the buffer 110, a main chamber residual pressure was blown off via the pressure relief connection 109. This has the consequence that the main combustion chamber pressure in the main combustion chamber 6 drops to ambient pressure and the control sleeve 34 pressure-controlled the exhaust ports or pressure relief connections 108, 109 closes again.

By a cooling of the bolt setting device 1 after setting arises in the main combustion chamber 6, a negative pressure. This negative pressure in the main combustion chamber 6 causes the driving piston 10 is sucked back into its original position or sucked back becomes. This is done by a Vorkammereinlass 140 at the in FIG. 7 24 fresh air sucked or sucked into the antechamber 25 of the bolt setting device 1. The intake of fresh air is in FIG. 7 indicated by an arrow 141.

The Vorkammereinlass 140 is advantageously associated with a one-way check valve. For example, the check valve includes a relatively large leaflet which, while allowing fresh air to be drawn into the prechamber 25, but in the reverse direction, prevents undesirable outflow of pressurized fuel and air mixture from the prechamber 25 into the environment.

When lifting the bolt gun 1 with the setting end 14, the FIG. 7 is shown cut off, from the ground, the combustion chamber sleeve 84 is again shifted so that the main combustion chamber 6 can be flushed with ambient air, as in FIG. 2 indicated by the arrows 81 and 82. Subsequently, a new setting cycle can be started.

In the FIGS. 8 to 11 For example, the controller 30 is shown alone in various views. The control device 30 comprises the control sleeve 34, which is connected via the coupling element 48 with a coupling sleeve 100. At a free end of the coupling sleeve 100, so in FIG. 9 right end of the coupling sleeve 100, which is designed as an annular surface 46 control pressure surface 45 is provided.

The coupling sleeve 100 is fixedly connected to a connecting flange 105 via slide rods 101, 102, 103, which partially represent the slider 50. The connecting flange 105 connects the control sleeve 34 with the slide rods 101 to 103. On the other side, the slide rods 101 to 103 are connected to the coupling sleeve 100 via a connecting flange 98.

Each slide rod 101 to 103 is associated with a spring device 54, 55 designed as a compression spring. The spring devices 54, 55 are clamped in the installed state of the control device 30 between the connecting flange 98 and the housing-fixed stops 56, 57 on the prechamber cylinder 24.

The control sleeve 34 serves to the passage openings 31, 32; 117, 118 release in the pre-chamber cylinder 24 as needed, as in FIG. 6 is indicated by the arrows 91 to 94. For this purpose, the control sleeve 34, the passage openings 37, 38; 117, 118, for opening the vent connections 108, 109 with the Through openings 31, 32; 111, 112 are brought into the pre-chamber cylinder 24 to cover.

In FIG. 10 it can be seen that the check valve device 120 comprises valve elements 121 to 123, which are interconnected by a connecting ring body 124. Each of the valve elements 121 to 123 comprises two closing elements 127, 128, the passage openings 37; 118 of the two pressure relief connections 108; 109 are assigned.

The valve elements 121 to 123 with the closing elements 127, 128 are integrally formed from spring steel. The production of the valve elements 121 to 123 with the closing elements 127, 128 takes place, for example, by laser beam cutting. The connecting ring body 124 may also be made by laser cutting from a spring steel material.

This in FIG. 12 Bolt setting tool 1 shown is additionally equipped with a detection device 180, which serves to detect a position, a starting position or a piston malfunction of the driving piston 10 before a settlement. The detection device 180 is indicated only by a rectangle and arranged, for example, between an inner housing and an outer housing of the setting device 1.

The detection device 180 comprises piston end position sensors 181, 182 and is connected to an electronic control unit 184 in terms of control. The control connections are indicated by dashed lines.

The piston end sensor 181 is arranged on one of the main combustion chamber 6 opposite end of the prechamber cylinder 24. The piston end sensor 182 is combined with a magnetic device 17 which provides magnetic restraint for the driving piston 10 in its in FIG. 12 represents initial situation shown.

The setting device 1 is also equipped with a sensor device 185. The sensor device 185 is used to detect environmental influences, such as an ambient temperature or an ambient pressure. The sensor device 185 is also connected to the electronic control unit 184 in terms of control.

The electronic control unit 184 is also connected to an injection device 187 via a control line 186 in terms of control. The injection device 187 is part of the inlet device 27, via which fuel gas is injected into the pre-chamber 25. The electronic control 184 is moreover control-wise via a control line 188 connected to an injector 189. The injection device 189 is part of the inlet device 8, via which fuel gas is injected into the main combustion chamber 6.

The piston end sensor 182 is designed, for example, as a proximity switch or contact switch. With the piston end sensor 182 can be detected in a simple manner, whether the driving piston 10 is in its defined starting position, the in FIG. 12 is shown.

The piston end position sensor 181 can advantageously also be embodied as a piston position sensor or as a sensor for detecting the piston travel of the drive piston 10. As a piston position sensor, the sensor 181 can detect whether the drive piston 10 has more or less than a predetermined error. For example, it can be detected with the sensor 181 whether the driving piston 10 has a fault of more or less than, for example, thirty percent.

If the sensor 181 is designed as a sensor for detecting the piston travel, then with the sensor 181, the initial position of the piston can be detected. For this purpose, the sensor 181 is designed, for example, as a Hall sensor and interacts with sensors with grooves which are provided on or in the piston rod 11 of the driving piston 10.

With the aid of the electronic control unit 184, it is distinguished how large a piston malfunction detected by the detection device 180 is. If the piston malfunction is small enough to operate the setting tool 1 in the usual way, then an injection takes place in both chambers 25, 6 and the ignition takes place initially only in the antechamber 25. The ignition in the pre-chamber 25 is through the Ignition 26 triggered, which is associated with the pre-chamber 25.

Although the piston malfunction detected by the detection device 180 is small enough to operate the setting tool 1 in the usual way but exceeds a certain first limit value, the injection quantity is adapted in at least one of the chambers 25, 6. For example, at a rather low piston malfunction, in which the driving piston 10 has stopped at a certain distance from the rear piston stop, a little more fuel gas is injected into the main combustion chamber 6 and correspondingly a little less gas in the pre-chamber 25. By this measure, the fuel remains Air mixture in both chambers 25, 6 approximately stoichiometric and can be ignited well.

If the piston malfunction detected with the detection device 180 is too great, that is to say exceeds a predetermined second limit which is greater than the first limit value, then the setting device 1 is ignited only in the main combustion chamber 6. Before that, an appropriate amount of fuel gas is injected into the main combustion chamber 6. In the antechamber 25 is not injected at a too large piston malfunction.

Following the injection into the main combustion chamber 6, only the main combustion chamber 6 is ignited, via the main combustion chamber 6 associated ignition device 9. Then, the setting device 1 is indeed operated with a lower energy, but the driving piston 10 comes after setting with less energy back to its defined starting position, which in FIG. 12 is shown. Thereafter, a normal setting cycle with an injection into both chambers 25, 6 take place.

This in FIG. 12 Setting device 1 shown provides the following advantages over the known prior art: higher reliability, because the in FIG. 12 setting device ensures that the pre-chamber and the main chamber combustion is reliable by the stoichiometric mixture preparation. There are no ignition failures or weak burns, which ultimately lead to lower energy. In the setting device 1 in FIG. 12 it is ensured that the unit energy remains constant by controlling the injection quantity. Of course, this does not apply to the case when ignited for piston failure elimination only in the main combustion chamber 6.

In addition, that delivers in FIG. 12 Setting tool 1 shown the advantage that a larger piston malfunction is detected automatically. Then it can be triggered automatically with less energy and only with a main chamber ignition. As a result, the driving piston 10 comes in its defined starting position and the setting tool 1 works normally again at the next setting cycle.

Claims (13)

Internal combustion setting device (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 driven via expandable gases from the main combustion chamber (6) in a setting direction (15), and with an antechamber (25), which is associated with an ignition device (26) and in which a pressure acting on the main combustion chamber (6) before the ignition of a fuel-air mixture in the main combustion chamber (6) can be built up, characterized in that the drive piston (10) is associated with a detection device (180) which is connected in terms of control with an electronic control (184) to detect a starting position of the drive piston (10) before a settlement. Internal combustion setting device according to Claim 1, characterized in that the detection device (180) assigned to the drive piston (10) comprises a piston end position sensor (182). Internal combustion setting device according to claim 2, characterized in that the piston end position sensor (182) comprises a proximity switch, a contact switch and / or an inductive switch. Internal combustion setting device according to one of the preceding claims, characterized in that the detection means (180) associated with the driving piston (10) comprises a piston position sensor (181). Internal combustion setting device according to claim 4, characterized in that the piston position sensor (181) comprises a Hall sensor, the grooves are assigned to the driving piston (10). Internal combustion setting device according to one of the preceding claims, characterized in that the setting device (1) comprises a control device (30) via which the setting energy from a differential pressure between the main combustion chamber (6) and an ambient pressure is determined. Internal combustion setting device according to one of the preceding claims, characterized in that the electronic control unit (184) is connected in terms of control to a sensor device (185) for detecting environmental conditions of the setting device (1). Internal combustion setting device according to one of the preceding claims, characterized in that an ignition device is arranged in the prechamber and / or in the main combustion chamber. Method for operating a combustion-powered setting tool (1) according to one of the preceding claims, characterized in that an injection quantity of fuel gas in the pre-chamber (25) and / or in the main combustion chamber (6) in dependence on the initial position of the driving piston (10) is controlled , A method according to claim 9, characterized in that only in the main combustion chamber (6) fuel gas is injected and ignited if a piston malfunction exceeds a predetermined limit. A method according to claim 9, characterized in that only in the antechamber (25) fuel gas is injected and ignited if a piston malfunction exceeds a predetermined limit. A method according to claim 9, characterized in that in the pre-chamber (25) and in the main combustion chamber (6) fuel gas is injected and ignited with a time difference, wherein the time difference is calculated based on sensor signals. Computer program product with a program code for performing a method according to one of claims 9 to 12, in particular when the program is executed in the electronic control of the setting device (1).

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