EP2465643B1 - Bolt setting device and method for operating same - Google Patents

Description

Technical area

The invention relates to a bolt setting device for setting fastening elements in a substrate, with a working piston which is abruptly translationally movable by igniting an ignitable mixture in a combustion chamber to set a fastener such as a bolt or a nail, wherein the volume of the combustion chamber is adjustable. The invention further relates to a method for operating such a bolt setting device.

State of the art

From the German patent DE 199 62 695 B4 a portable combustion-powered bolt gun is known, which has a combustion chamber for receiving an internal combustion mixture, the size of which is variable by an axial displacement of an end combustion chamber wall for adjusting the fuel gas mixture present in her lean or rich. From the German patent application DE 10 2005 000 032 A1 a combustion-powered setting tool with two sub-chambers is known, between which a separating element is arranged, wherein through-openings have an active opening cross-section.

Presentation of the invention

The object of the invention is to improve the operation and / or energy efficiency of a bolt gun according to the preamble of claim 1 on.

The object is in a bolt setting device for setting fasteners in a substrate, with a working piston which is abruptly translationally movable by igniting an ignitable mixture in a combustion chamber to a fastener, such as a bolt or a nail to set, the volume of the combustion chamber is adjustable, achieved in that the bolt setting device comprises a control device which is connected in terms of control with an adjusting device for adjusting the combustion chamber volume and with a metering valve device for metering fuel gas. The bolt gun according to the invention is preferably a portable combustion-powered bolt gun. To set a fastening element, gas, for example from a gas cartridge, is mixed with oxygen or air in the combustion chamber to form an ignitable mixture. When the ignitable mixture is ignited, it expands abruptly to drive the working piston. Due to the combination of the adjusting device with the metering valve device according to the invention, the bolt setting device can cover a large energy range with efficient energy utilization. The load of the bolt gun during operation is significantly reduced, especially in the case of bolting with minimal energy. This prolongs the life of the bolt gun.

A preferred embodiment of the bolt setting tool is characterized in that the adjusting device for adjusting the combustion chamber volume comprises a motor, in particular an electric motor. To adjust the combustion chamber volume, a stepper motor is particularly preferably used. The motor is controlled by the control device.

Another preferred embodiment of the bolt-firing device is characterized in that the engine is coupled via a transmission with an adjustable combustion chamber wall. The transmission is preferably designed so that it remains in its current position when loaded by the combustion chamber pressure by self-locking. In addition, the transmission is preferably designed such that the combustion chamber pressure does not act on the engine. The motor is preferably mounted with the aid of damping elements in the bolt setting device.

A further preferred embodiment of the bolt-firing device is characterized in that the control device is connected to an operating device for energy adjustment and / or a display device which displays energy information. With the help of the operating device can be adjusted by a user or user in a simple manner, a desired amount of set energy. With the help of the display device, the desired amount of set energy can be displayed in a simple manner. In addition, with the help of the display device a minimum and maximum possible amount of energy is displayed. As a result, the ease of use of the bolt gun is significantly increased.

The above object is achieved alternatively or additionally by a method for operating a bolt-firing device described above, wherein both the combustion chamber volume and the metering of the combustion gas supplied to the combustion chamber is adjusted by means of the control device. Thereby, the amount of energy provided in the bolt setting tool for driving fasteners can be set very quickly and efficiently. This makes it possible in particular to collect different fasteners in different substrates without energy is wasted. By adjusting both the combustion chamber volume and the amount of fuel gas supplied, the mixing ratio in the combustion chamber can be optimally adjusted.

A preferred embodiment of the method is characterized in that the current actual combustion chamber volume is detected and compared with a desired target combustion chamber volume. The setting of the combustion chamber volume can be stored in the control device.

A further preferred exemplary embodiment of the method is characterized in that a manipulated variable for the adjusting device for adjusting the combustion chamber volume is determined from deviations between the current actual combustion chamber volume and the desired setpoint combustion chamber volume. The desired combustion chamber volume is specified by the user or user. The determined manipulated variable is used to control the motor, with the help of which the combustion chamber volume is adjusted.

A further preferred embodiment of the method is characterized in that the bolt setting device has a reset function which is triggered by a user interaction and in which the adjustment of the combustion chamber volume and / or the metering of the fuel gas supplied to the combustion chamber is / is calibrated. The reset function is triggered, for example, by inserting a rechargeable battery or a gas cartridge into the bolt setting tool.

A further preferred embodiment of the method is characterized in that the adjusting device for adjusting the combustion chamber volume is moved against a stop during a reset. For example, when the motor is reset, the motor is turned on move a stop. Upon reaching the stop, the engine remains in the approached position, for example by blocking further adjustment or by shutting off the engine.

A further preferred embodiment of the method is characterized in that the current actual combustion chamber volume is detected by means of a sensor device. By comparison with the desired nominal combustion chamber volume, the necessary adjustment of the engine is determined. A reset function for position determination can be omitted.

A further preferred embodiment of the method is characterized in that the metering valve device is normally closed and is opened by the control device for a predetermined time, so that a defined amount of gas flows into the combustion chamber. The gas is taken, for example, a gas cartridge, which is arranged interchangeable in the bolt setting device. By varying the opening time of the metering valve device, the amount of gas can be adjusted.

A further preferred embodiment of the method is characterized in that a desired amount of set energy, a minimum possible set energy amount and / or a maximum possible set energy amount are displayed on the bolt setting device. The respective amount of set energy is preferably displayed with the aid of the previously described display device.

Figur 1

zeigt eine vereinfachte Darstellung eines erfindungsgemäßen Bolzensetzgeräts im Schnitt mit einer Bedieneinrichtung.

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.

FIG. 1

shows a simplified representation of a bolt gun according to the invention in section with an operating device.

embodiments

In FIG. 1 an inventive bolt setting device 1 with a housing 2 is shown in a simplified longitudinal section. The housing 2 comprises a handle 4, on which the bolt setting device 1 can be tacked for driving in a fastening element, which exits from the bolt setting device 1 at a bolt setting end 5 and can be driven into a ground.

The energy required for driving the fastening element into the ground is provided, for example, in a gas cartridge 8 in the interior of the bolt setting device 1. The gas cartridge 8 is connected via an adjustable or controllable metering valve 10 with a combustion chamber or a combustion chamber 12. Into the combustion chamber 12, gas from the gas canister 8 is mixed with air to form a combustible mixture which is ignited to drive a fastener such as a bolt or a nail into the ground.

The combustion chamber 12 is surrounded by a cylinder 14 inside the housing 2. On one side, in particular an end face of the cylinder 14, the combustion chamber 12 is closed by an adjustable combustion chamber wall or combustion chamber wall 15. The combustion chamber wall 15 can be adjusted by means of an electric motor 16 via a control gear 17, as indicated by a double arrow 18. By adjusting the combustion chamber wall 15 in the direction of the double arrow 18, the size of the combustion chamber 12 can be varied in a simple manner.

State variables in the combustion chamber 12 and / or the position of the adjustable combustion chamber wall 15 can be detected with the aid of a sensor device 20. The sensor device 20 is connected via a sensor line 21 to an electrical or electronic control device 25. The control device 25 is connected via a control line 26 in terms of control with the electric motor 16. From an accumulator 28, for example a battery, the control device 25 is supplied with electrical energy. Via a further control line 29, the control device 25 is connected in terms of control with the metering valve 10.

The combustion chamber 12 is closed at its side facing away from the adjustable combustion chamber wall 15, in particular end face by a piston head 32 of a working piston 34. The working piston 34 is guided on the one hand with the piston head 32 in a cylinder and on the other hand at its end remote from the piston head 32 in a guide sleeve. In this case, the working piston 34 extends through a buffer device 38 therethrough. The movement of the working piston 34 when driving a fastener is braked by the fastener and in case of excess kinetic energy by the buffer means 38.

The driving of a fastener is triggered by a trigger 42 which is on the handle 4, for example, with the index finger operable. The bolt setting device 1 according to the invention comprises, in addition to the trigger 42, an operating device 44 with a control element 45.

The bolt setting device 1 according to the invention comprises, in addition to the trigger 42 and the operating device 44, a display device 55 for displaying energy information during operation of the bolt setting device 1. The display device 55 is connected to the electrical or electronic control device 25 and comprises, for example, a display with which the energy information alphanumerically and / or graphically, for example, with icons, can be displayed. Alternatively or additionally, the display device 55 may have a color display.

With the operating element 45, the user or user of the bolt setting device 1 can specify a desired value for the driving energy. The predetermined target value and / or the desired field of application, for example "wood" for low energy amounts, "concrete" for medium energy amounts and "steel" for high energy amounts, is displayed by the display device 55. In addition, the display device 55 displays the maximum and minimum possible driving energy that can currently be output by the bolt setting device 1. Upon reaching over or underload limits, the user is warned by a display element of the display device 55 or by a signal tone.

During operation of the bolt setting device 1, the associated combustion chamber volume and the necessary gas quantity are determined with the aid of the control device 25, preferably taking into account ambient parameters such as the ambient temperature and the ambient pressure, for a desired setpoint driving energy quantity. To set the desired combustion chamber volume, the control device 25 outputs signals to the electric motor 16.

The electric motor 16 is preferably designed as a servo motor and adjusted via the adjusting 17, the combustion chamber wall 15. The actuating mechanism 17 is preferably designed so that it acts at a load by the combustion chamber pressure acting on the actuating mechanism 17 via the combustion chamber wall 15, by self-locking in his current position remains. In addition, the actuating gear 17 is preferably designed so that the combustion chamber pressure does not act on the electric motor 16.

The setting of the desired combustion chamber volume is stored in the electrical control device 25. From a deviation between a setpoint input by the user and a stored or determined position value of the combustion chamber wall 15, a manipulated variable for the electric motor 16 is determined, with which the combustion chamber volume is adapted via the setting mechanism 17.

The bolt gun according to the invention has a reset function in which the combustion chamber volume setting is recalibrated. The reset function is started, for example, by a user interaction. For example, the insertion of the battery 28 or the gas cartridge 8 lead to a reset. During the reset, the combustion chamber volume adjustment, for example the adjusting gear 17 or the combustion chamber wall 15, is moved against a stop.

Two different methods can be used for calibration. On the one hand, the electric motor 16 can be safely driven against a stop with a sufficiently large number of steps. Upon reaching the stop of the electric motor 16 is further charged, but blocked the adjustment. As a result, the electric motor 16 remains in its stop position. Alternatively, a current-voltage characteristic of the electric motor 16 can be detected. As a result of the change in the current-voltage characteristic when reaching the stop of the electric motor 16 is turned off.

According to a further embodiment, the current actual combustion chamber volume is detected with the aid of the sensor 20. By comparison with the desired target combustion chamber volume, a necessary adjustment of the combustion chamber wall 15 can be determined by means of the electric motor 16 via the control gear 17. When using the sensor 20, the previously described reset function can be omitted.

The metering valve 10 is preferably electrically operated and is biased in its closed position. During operation of the bolt setting device 1, the metering valve 10 is actuated by the control device 25 and opened for a predetermined time. With the metering valve 10 open, gas can flow from the gas cartridge 8 into the combustion chamber 12. By varying the opening time, the amount of gas can be adjusted.

Claims (12)

1. Stud setting tool for setting fasteners in place in a substrate, having a working piston (34) which, by the ignition of an ignitable mixture in a combustion chamber (12), can be moved percussively in translation in order to set in place a fastener such as a stud or a nail, the volume of the combustion chamber (12) being adjustable, characterised in that the stud setting tool (1) comprises a control means (25) which is connected in a controlling capacity to an adjusting means for adjusting the combustion chamber volume and to a metering valve means (10) for metering combustible gas.
2. Stud setting tool according to claim 1, characterised in that the adjusting means for adjusting the combustion chamber volume comprises a motor (16) and in particular an electric motor.
3. Stud setting tool according to claim 2, characterised in that the motor (16) is coupled via gearing (17) to an adjustable combustion chamber wall (15).
4. Stud setting tool according to one of the preceding claims, characterised in that the control means (25) is connected to an operating means (44) for setting energy and/or to an indicating means (55) which indicates information on energy.
5. Method of operating a stud setting tool according to one of the preceding claims, characterised in that both the combustion chamber volume and the metering of the combustible gas fed to the combustion chamber (12) are set with the help of the control means (25).
6. Method according to claim 5, characterised in that the current actual combustion chamber volume is sensed and is compared with a desired combustion chamber volume which is aimed for.
7. Method according to claim 6, characterised in that a controlling variable for the adjusting means for adjusting the combustion chamber volume is determined from differences between the current actual combustion chamber volume and the desired combustion chamber volume which is aimed for.
8. Method according to one of claims 5 to 7, characterised in that the stud setting tool (1) has a reset function which is triggered by a user interaction and in which the setting of the combustion chamber volume and/or the metering of the combustible gas fed to the combustion chamber (12) are/is calibrated.
9. Method according to claim 8, characterised in that the adjusting means for adjusting the combustion chamber volume is moved towards a stop in a reset.
10. Method according to claim 8 or 9, characterised in that the current actual combustion chamber volume is sensed with the help of a sensor means (20).
11. Method according to one of claims 5 to 10, characterised in that the metering valve means (10) is normally closed and is opened by the control means (25) for a predetermined time, a defined quantity of gas thus flowing into the combustion chamber (12).
12. Method according to one of claims 5 to 11, characterised in that an amount of setting energy which is aimed for, a minimum possible amount of setting energy and/or a maximum possible amount of setting energy are indicated on the stud setting tool (1).

Images