EP3801994A1

EP3801994A1 - Setting tool

Info

Publication number: EP3801994A1
Application number: EP19726437.7A
Authority: EP
Inventors: Tilo Dittrich; Norbert Heeb
Original assignee: Hilti AG
Current assignee: Hilti AG
Priority date: 2018-06-06
Filing date: 2019-05-29
Publication date: 2021-04-14
Also published as: JP2021525179A; EP3578306A1; US20210178561A1; AU2019283304A1; WO2019233852A1; TW202012122A

Abstract

The invention relates to a setting tool for driving securing elements into a substrate, comprising a recess which is provided for accommodating a securing element, a drive-in element which is provided to transfer a securing element accommodated in the recess along a setting axis into the substrate, a drive which is provided for driving the drive-in element along the setting axis towards the securing element, wherein the drive has an electrical capacitor which is arranged on the setting axis or about the setting axis.

Description

setting tool

The present invention relates to a setting device for driving fasteners into a substrate.

Such setting tools usually have a receptacle for a fastening element, from which a fastener received therein is conveyed along a setting axis into the ground. A driving element is for this purpose driven by a drive along the setting axis to the fastener.

From US 6,830,173 B2 a setting device with a drive for a driving element is known. The drive has an electrical capacitor and a coil. To drive the driving element, the capacitor is discharged via the coil, whereby a Lorentz force acts on the driving element, so that the driving element is moved towards a nail.

The object of the present invention is to provide a setting device of the aforementioned type, in which a high efficiency and / or a good setting quality is ensured.

The object is achieved in a setting tool for driving fasteners into a substrate, comprising a receptacle, which is intended to receive a fastener, a driving element, which is intended to convey a recorded in the receiving fastener along a setting axis in the ground a drive, which is provided for driving the driving element along the setting axis on the fastening element, wherein the drive comprises an exciting coil, which is fed with current and generates a magnetic field, which accelerates the driving element to the fastening element, and a An abutment member which supports the driving member against movement toward the exciting coil when the driving member is in a setting position, the driving member being spaced apart from the exciting coil in the setting position. The setting tool is preferably handheld used. Alternatively, the setting device can be used stationary or semi-stationary.

A capacitor in the sense of the invention is to be understood as meaning an electrical component which stores electrical charge and the energy associated therewith in an electric field. In particular, a capacitor has two electrically conductive electrodes, between which the electric field builds up when the electrodes are electrically charged differently. Under a fastener according to the invention, for example, a nail, a pin, a clip, a clip, a bolt, in particular threaded bolt or the like to understand.

A preferred embodiment is characterized in that an air gap is formed between the driving element and the exciter coil when the driving element is in a position ready for setting. The air gap preferably has a gap width which is between 0 and 0.5 mm, particularly preferably between 0.01 mm and 0.2 mm, for example between 0.02 mm and 0.1 mm.

A preferred embodiment is characterized in that the stop element has a stop surface facing the receptacle and the drive element has a counter surface facing away from the receptacle, and wherein the stop surface and the counter surface abut each other when the drive element is in a position ready for setting. Preferably, the stop surface and / or the counter surface is arranged on the setting axis or around the setting axis. Also preferably, the stop surface and / or the counter surface is convex, more preferably spherical.

A preferred embodiment is characterized in that a projection of the stop element in the direction of the setting axis is arranged radially within a projection of the exciting coil in the direction of the setting axis. Preferably, the stop element is arranged radially with respect to the setting axis within the exciter coil.

A preferred embodiment is characterized in that the drive comprises a soft-magnetic frame on which the exciter coil is arranged. Preferably, the exciter coil is embedded in the soft magnetic frame. Preferably, the driving element is spaced in the position ready for setting of the soft magnetic frame. Particularly preferably forms between the driving element and the soft magnetic frame from another air gap, when the driving element is in the setting position.

A preferred embodiment is characterized in that the soft magnetic frame is annular, wherein a projection of the stop element in the direction of the setting axis is arranged radially within a projection of the soft magnetic frame in the direction of the setting axis. Preferably, the stop element is arranged radially with respect to the setting axis within the soft magnetic frame.

A preferred embodiment is characterized in that the stop element and / or the driving element comprises a damper, which has the stop surface or the counter surface. Preferably, the damper attenuates an abutment of the driving element to the stop element.

A preferred embodiment is characterized in that the drive comprises an electrical capacitor, which is preferably arranged on the setting axis or around the setting axis, and upon discharge, the exciting coil is traversed by current to generate the magnetic field. A further embodiment is characterized in that the drive has a squirrel cage arranged on the driving, which is penetrated by the magnetic field generated by the field coil.

In the drawings, the invention is shown in several embodiments.

Show it:

Fig. 1 is a setting tool in a longitudinal section and

Fig. 2 is a setting tool in a longitudinal section.

In Fig. 1, a hand-held setting tool 10 is shown for driving fasteners in a substrate, not shown. The setting tool 10 has a receptacle 20 designed as a bolt guide, in which a fastening element 30 embodied as a nail is received in order to be driven into the underground along a setting axis A (in FIG. 1 to the left). For a supply of fastening elements to the receptacle, the setting device 10 comprises a magazine 40 in which the fastening elements are accommodated individually or in the form of a fastener element strip 50 and are transported gradually into the receptacle 20. The magazine 40 has for this purpose an unspecified spring-loaded feed element. The setting tool 10 has a drive-in element 60, which comprises a piston plate 70 and a piston rod 80. The driving-in element 60 is intended to transport the fastening element 30 out of the receptacle 20 along the setting axis A into the ground. Here, the driving element 60 is guided with its piston plate 70 in a guide cylinder 95 along the setting axis A.

The driving element 60 in turn is driven by a drive which comprises a squirrel cage 90 arranged on the piston plate 70, an excitation coil 100, a soft magnetic frame 105, a circuit 200 and a capacitor 300 with an internal resistance of 5 mOhm. The short-circuit rotor 90 consists of a preferably annular, particularly preferably annular element with a low electrical resistance, for example copper, and is fastened on the side facing away from the receptacle 20 side of the piston plate 70 on the piston plate 70, for example, soldered, welded, glued, clamped or positively connected. In embodiments not shown, the piston plate itself is designed as a squirrel-cage rotor. The circuit 200 is intended to cause a rapid electrical discharge of the previously charged capacitor 300 and to guide the discharge current flowing through it through the excitation coil 100, which is embedded in the frame 105. The frame preferably has a saturation flux density of at least 1.0 T and / or an effective electrical conductivity of at most 10 ⁶ S / m, so that a magnetic field generated by the exciter coil 100 amplifies from the frame 105 and suppresses eddy currents in the frame 105 become.

In a setting position of the driving-in element 60 (FIG. 1), the driving element 60 with the piston plate 70 dips into an unspecified annular depression of the frame 105 in such a way that the squirrel-cage rotor 90 is arranged at a small distance with respect to the exciter coil 100. As a result, an exciter magnetic field, which is generated by a change in an electrical exciter current flowing through the excitation coil, passes through the squirrel cage rotor 90 and in turn induces an annular secondary electric current in the squirrel cage rotor 90. This developing and thus changing secondary current in turn generates a secondary magnetic field, which is opposite to the excitation magnetic field, whereby the squirrel cage rotor 90 experiences a repelling of the excitation coil 100 Lorentz force, which drives the driving element 60 on the receptacle 20 and the fastener 30 received therein ,

The setting device 10 further comprises a housing 1 10, in which the drive is accommodated, a handle 120 with a designed as a trigger actuator 130, as a Accumulator-formed electrical energy storage 140, a control unit 150, a trigger switch 160, a pressure switch 170, as designed as a frame 105 arranged on the temperature sensor 180 means for detecting a temperature of the excitation coil 100 and electrical connection lines 141, 161, 171, 181, 201, 301 which connect the control unit 150 with the electrical energy storage 140, the trigger switch 160, the pressure switch 170, the temperature sensor 180, the circuit 200 and the capacitor 300, respectively. In embodiments not shown, the setting tool 10 is supplied instead of the electrical energy storage 140 or in addition to the electrical energy storage 140 by means of a power cable with electrical energy. The control unit comprises electronic components, preferably interconnected on a circuit board to one or more control circuits, in particular one or more microprocessors.

When the setting device 10 is pressed against a substrate (not shown in FIG. 1 on the left), an unspecified contact element actuates the contact pressure switch 170, which thereby transmits a contact signal to the control unit 150 by means of the connecting line 171. Triggered by this, the control unit 150 initiates a capacitor charging process in which electrical energy is conducted from the electrical energy storage 140 to the control unit 150 via the connection line 141 and from the control unit 150 to the condenser 300 via the connection lines 301 in order to charge the capacitor 300 , For this purpose, the control unit 150 comprises a switching converter (not designated in more detail) which converts the electric current from the electrical energy store 140 into a suitable charging current for the capacitor 300. When the capacitor 300 is charged and the driving member 60 is in its set ready position shown in Fig. 1, the setting tool 10 is in a ready to be placed state. Characterized in that the charging of the capacitor 300 is effected only by the pressing of the setting device 10 to the ground, a setting process is only possible to increase the safety of bystanders when the setting tool 10 is pressed against the ground. In embodiments not shown, the control unit initiates the capacitor charging process already when the setting device is switched on or when the setting device is lifted off the ground or at the end of a preceding driving operation.

If the actuating element 130 is actuated when the setting tool 10 is ready for setting, for example by pulling with the index finger of the hand, which encompasses the handle 120, the actuating element 130 actuates the trigger switch 160, which thereby transmits a triggering signal to the control unit 150 via the connecting line 161. From that triggered, the control unit 150 initiates a capacitor discharge, in which in the capacitor 300 stored electrical energy is conducted by means of the circuit 200 from the capacitor 300 to the exciter coil 100 by the capacitor 300 is discharged.

The circuit 200 shown schematically in FIG. 1 for this purpose comprises two discharge lines 210, 220 which connect the capacitor 300 to the exciter coil 200 and of which at least one discharge line 210 is interrupted by a normally open discharge switch 230. The circuit 200 forms an electrical resonant circuit with the exciter coil 100 and the capacitor 300. A swinging back and forth of this resonant circuit and / or a negative charging of the capacitor 300 may have a negative effect on an efficiency of the drive, but can be prevented by means of a freewheeling diode 240. The discharge lines 210, 220 are electrically connected by means of one of the receptacle 20 facing the end face 360 of the capacitor 300 electrical contacts 370, 380 of the capacitor 300, each with an electrode 310, 320 of the capacitor 300, for example by soldering, welding, screwing, jamming or form-fitting. The discharge switch 230 is preferably suitable for switching a discharge current with high current and is designed, for example, as a thyristor. In addition, the discharge lines 210, 220 have a small distance from one another, so that a parasitic magnetic field induced by them is as small as possible. For example, the discharge lines 210, 220 are combined into a bus bar and held together by a suitable means, for example a holder or a clamp. In embodiments not shown, the freewheeling diode is electrically connected in parallel to the discharge switch. In further embodiments, not shown, no free-wheeling diode is provided in the circuit.

To initiate the capacitor discharge process, the control unit 150 closes the discharge switch 230 by means of the connection line 201, whereby a discharge current of the capacitor 300 flows through the exciter coil 100 with high current intensity. The rapidly increasing discharge current induces a field magnetic field, which passes through the squirrel-cage rotor 90 and induces in its squirrel-cage rotor 90, in turn, an annular secondary electric current. This secondary current that builds up in turn generates a secondary magnetic field which is opposite to the excitation magnetic field, whereby the squirrel cage rotor 90 experiences a Lorentz force repelling the exciting coil 100, which drives the driving element 60 onto the receptacle 20 and the fastening element 30 received therein. Once the piston rod 80 of the driving 60th strikes an unspecified head of the fastener 30, the fastener 30 is driven by the driving element 60 into the ground. Excess kinetic energy of the driving element 60 is absorbed by a braking element 85 made of a resilient and / or damping material, such as rubber, by the driving element 60 moves with the piston plate 70 against the brake member 85 and is braked by this to a standstill. Thereafter, the driving-in element 60 is returned to the setting position by an unspecified return device.

The capacitor 300, in particular its center of gravity, is arranged on the setting axis A behind the driving element 60, whereas the receptacle 20 is arranged in front of the driving element 60. With regard to the setting axis A, the capacitor 300 is thus arranged axially offset from the driving-in element 60 and radially overlapping with the driving-in element 60. As a result, on the one hand, a short length of the discharge lines 210, 220 can be realized, as a result of which the resistances thereof can be reduced and thus an efficiency of the drive can be increased. On the other hand, a small distance of a center of gravity of the setting device 10 to the setting axis A can be realized. As a result, tilting moments during a recoil of the setting device 10 during a driving operation are low. In an embodiment, not shown, the capacitor is arranged around the driving element around.

The electrodes 310, 320 are arranged on opposite sides on a carrier film 330 wound around a winding axis, for example by metallization of the carrier film 330, in particular vapor-deposited, the winding axis coinciding with the setting axis A. In embodiments not shown, the carrier foil with the electrodes is wound around the winding axis so that a passage remains along the winding axis. In particular, in this case, the capacitor is arranged for example around the setting axis. The carrier film 330 has a film thickness of between 2.5 μm and 4.8 μm for a charging voltage of the capacitor 300 of 1500 V, and a film thickness of, for example, 9.6 μm for a charging voltage of the capacitor 300 of 3000 V. In embodiments not shown, the carrier film is in turn composed of two or more individual films stacked on top of each other. The electrodes 310, 320 have a sheet resistance of 50 ohms / n.

A surface of the capacitor 300 has the shape of a cylinder, in particular a circular cylinder whose cylinder axis coincides with the setting axis A. A height of this cylinder in the direction of the winding axis is substantially as large as its diameter measured perpendicular to the winding axis. By a low ratio of height to Diameter of the cylinder, a low internal resistance at a relatively high capacitance of the capacitor 300 and not least a compact design of the setting device 10 are achieved. A low internal resistance of the capacitor 300 is also achieved by a large cross-section of the electrodes 310, 320, in particular by a high layer thickness of the electrodes 310, 320, wherein the effects of the layer thickness on a self-healing effect and / or a lifetime of the capacitor 300 are to be considered.

The capacitor 300 is damped by means of a damping element 350 mounted on the other setting tool 10. The damping element 350 damps movements of the capacitor 300 relative to the rest of the setting device 10 along the setting axis A. The damping element 350 is arranged on the end face 360 of the capacitor 300 and covers the end face 360 completely. As a result, the individual windings of the carrier film 330 are uniformly loaded by a recoil of the setting device 10. The electrical contacts 370, 380 protrude from the end face 360 and penetrate the damping element 350. The damping element 350 has for this purpose in each case an exemption, through which the electrical contacts 370, 380 protrude. The connecting lines 301 have to compensate for relative movements between the capacitor 300 and the other setting tool 10 each have a discharge and / or expansion loop, not shown. In non-illustrated embodiments, a further damping element is arranged on the capacitor, for example on its end facing away from the receptacle end face. Preferably, the capacitor is then clamped between two damping elements, that is, the damping elements are applied to the capacitor with a bias voltage. In further embodiments, not shown, the connecting lines have a rigidity which decreases continuously with increasing distance from the capacitor.

In Fig. 2, another embodiment of a hand-held setting tool 410 for driving fasteners along a set axis A 'is shown in a substrate, not shown. Analogous to the setting device 10 shown in FIG. 1, the setting device 410 comprises a receptacle 420 formed as a bolt guide, in which a fastening element 430 designed as a nail is received, a magazine 440 in which the fastening elements are accommodated individually or in the form of a fastener element strip 450 , a driving member 460, which comprises a piston plate 470 and a piston rod 480, a guide cylinder 495, in which the piston plate 470 is guided, a brake member 485 and a stopper member 580th The driving element 460 is driven by a drive which comprises a squirrel cage 490 arranged on the piston plate 470, an exciter coil 500, an annular soft magnetic frame 505, a not shown circuit and a capacitor, also not shown. The setting device 410 further comprises a housing 510, in which the drive is accommodated, a handle 520 with a trained as a trigger actuator 530 and other components not shown, such as an electrical energy storage or power cable, a control unit, a trigger switch, a pressure switch and electrical connection lines which connect the control unit with the electrical energy storage, the trigger switch, the pressure switch, the circuit or the capacitor, and a reset device.

2, the stop element 580 supports the driving element 460 against movement on the excitation coil 500 from. In the position ready for setting of the driving element 460 shown in FIG. In this case, the driving element 460 is spaced apart from the soft magnetic frame 505 to form an air gap 590 with a gap width of 0.05 mm from the excitation coil 500 and with the formation of a further air gap 595 with a gap width of, for example, 0.5 mm. An impact of the driving element 460 on the excitation coil 500 is thereby prevented or mitigated, which is additionally attenuated under certain circumstances by means of an air cushion between the driving element 460 and the exciter coil 500. With the help of the stop element 580 a small gap width and thus a large repulsive force between the exciter coil 500 and the squirrel cage 490 is ensured. The stop element 580 has a receptacle 420 facing convex abutment surface 585, which is arranged on the setting axis A '. The driving-in element 460 has a plane counter surface 465 facing away from the receptacle 420, which is likewise arranged on the setting axis A '. In embodiments not shown, instead of or in addition to the stop surface, the counter surface is convex, in particular convex. 2, the stop surface 585 and the mating surface 465 abut against each other. With respect to the setting axis A ', the stopper member 580 is disposed radially inside the exciting coil 500 and radially inside the soft magnetic frame 505. The stop element 580 comprises a damper 581 which has the stop surface 585 and damps a stop of the driving element 460 against the stop element 580.

The setting device 410 functions essentially the same as the setting device 10 shown in FIG. 1. When the driving element 60 is returned to the setting position by the restoring device, the counter surface 465 lays or strikes the stop surface 585. A mechanical stress of the exciter coil 500 and / or of the soft magnetic frame 505 is reduced due to the respective distance of the excitation coil 500 and the soft magnetic frame to the driving element 460.

Preferably, the piston rod 480 passes through the piston plate 470 and has the mating surface 465. The piston rod 480 is made of an impact-resistant material such as steel, so that a wear of the piston rod 480 is reduced in the recurring impact on the fasteners 430 and / or the likewise recurrent impact on the stop member 580. The piston plate 470 is protected by the inventive arrangement from shocks and consists of a material of low density, such as aluminum, so that a total mass of the driving element 460 and thus an energy required for its acceleration is reduced. The stop element 580 is preferably rod-shaped and is preferably made of an impact-resistant material such as steel and is directly or indirectly, for example by means of a reinforcement 506 of the soft magnetic frame 505 and / or a fastener 507, for example a screw or nut, supported on the housing 510 , in particular fastened.

The invention has been described with reference to a number of illustrated in the drawings and not shown embodiments. The individual features of the various embodiments are individually or in any combination applicable to each other, unless they contradict each other. It should be noted that the setting tool according to the invention can also be used for other applications.

Claims

cLAIMS

1. Setting tool for driving fasteners into a substrate, in particular hand-held setting tool, comprising a receptacle which is intended to receive a fastener, a driving element, which is intended to convey a recorded in the recording fastener along a setting axis in the ground a drive, which is intended to drive the driving element along the setting axis on the fastening element, wherein the drive comprises an exciting coil, which is fed with current and generates a magnetic field, which accelerates the driving element to the fastening element, and a stop element, which supports the driving member against movement on the exciting coil when the driving element is in a setting position, wherein the driving element is spaced in the position ready for setting of the exciting coil.

2. Setting device according to claim 1, wherein an air gap is formed between the driving element and the exciter coil when the driving element is in a position ready for setting.

3. Setting device according to claim 2, wherein the air gap has a gap width which is between 0 and 0.5 mm, in particular between 0.01 mm and 0.2 mm, in particular between 0.02 mm and 0.1 mm.

4. Setting tool according to one of the preceding claims, wherein the stop element has a receiving surface facing the stop and the driving element has a facing away from the receiving counter surface, and wherein the stop surface and the counter surface abut each other when the driving element is in a position ready for setting.

5. Setting tool according to claim 4, wherein the stop surface and / or the counter-surface is arranged on the setting axis or around the setting axis.

6. Setting tool according to one of claims 4 to 5, wherein the stop surface and / or the counter surface is convex, in particular convex.

7. Setting device according to one of the preceding claims, wherein a projection of the stop element in the direction of the setting axis is arranged radially within a projection of the exciting coil in the direction of the setting axis.

8. Setting tool according to claim 7, wherein the stop element is arranged with respect to the setting axis radially within the exciter coil.

9. Setting device according to one of the preceding claims, wherein the drive comprises a soft magnetic frame on which the exciter coil is arranged, wherein the excitation coil is embedded in particular in the soft magnetic frame.

10. Setting tool according to claim 9, wherein the driving element is spaced in the position ready for setting of the soft magnetic frame.

1 1. Setting device according to one of claims 9 to 10, wherein between the driving element and the soft magnetic frame, a further air gap is formed when the driving element is in the setting position.

12. Setting tool according to one of the preceding claims, wherein the soft magnetic frame is annular, and wherein a projection of the stop element is arranged in the direction of the setting axis radially within a projection of the soft magnetic frame in the direction of the setting axis.

13. Setting tool according to claim 12, wherein the stop element is arranged with respect to the setting axis radially within the soft magnetic frame.

14. Setting tool according to one of the preceding claims, wherein the stop element and / or the driving element comprises a damper, which has the stop surface or the counter surface.

15. Setting tool according to claim 14, wherein the damper attenuates an abutment of the driving element to the stop element.