METHOD FOR CONTROLLING AND REGULATING A MACHINE TOOL

Description

[0001] The present invention relates to a method for controlling and regulating a machine tool, in particular a chisel hammer, comprising a drive, a control device, a sensor device, a transmission device and a handle device, wherein the handle device includes a lever element with a signal transmitter which is pivotable relative to the sensor device.

[0002] Furthermore, the present invention relates to a handle device on a machine tool, in particular a chisel hammer, comprising a drive, a control device, a transmission device, wherein the handle device includes a lever element which is pivotable relative to a housing of the machine tool.

[0003] A chisel hammer, according to the state of the art, is used for working (i.e., breaking, splitting, or chiseling) mineral materials such as concrete, brick, or the like. The chisel hammer can also be called a demolition, dismantling, or breaker hammer. The chisel hammer has a drive mechanism that transmits impacts to a chisel tool (also called a chisel) via a transmission mechanism. This drive mechanism can be an electric motor or an internal combustion engine. The transmission mechanism can also be called a striking mechanism.

[0004] A chisel hammer typically has two handles positioned on opposite sides of the housing. At least one of the handles incorporates an activation switch for turning the chisel hammer on. The handles are usually positioned at an obtuse angle to the longitudinal axis of the housing. To use the chisel hammer, the activation switch is pressed, activating the hammer so that impacts are transmitted from the drive mechanism to the chisel.

[0005] Such chisel hammers are known, for example, from EP 2 058 089 A1 and DE 10 2011 080 374 A1, which disclose a method according to the preamble of claim 1.

[0006] One problem with a chisel hammer according to the state of the art is that after activation (i.e., switching on), the drive usually operates at a relatively high or even maximum speed, and consequently, the chisel hammer runs at full power. If the user does not yet have sufficient control of the chisel hammer at this point—that is, if the user has not yet positioned both hands on the respective handles and is not holding the chisel hammer firmly—the chisel hammer is inadequately guided, and adequate and safe work is not possible. Furthermore, there is the general problem that the activation (i.e., switching on) of the chisel hammer and the delivery of blows can surprise the user, since, although the user is already holding the chisel hammer firmly, they have not yet anticipated the activation (i.e., switching on) and the delivery of blows.

[0007] It is therefore an object of the present invention to solve the aforementioned problem and to provide a method for controlling and regulating a machine tool, in particular a chisel hammer, wherein the sensitivity of the handle device can be adjusted by a user to individual needs.

[0008] The problem is solved by the subject matter in claim 1.

[0009] The problem is solved by a method for controlling and regulating a machine tool, in particular a chisel hammer, with a drive, a control device, a sensor device, a transmission device and a handle device, wherein the handle device includes a lever element with a signal transmitter which is pivotable relative to the sensor device, comprising the following method steps: Detection of a first and second position of the signal transmitter by the sensor device; determination of a distance traveled by the signal transmitter from the first position to the second position by the control device; and setting the drive from a deactivation mode to an activation mode by the control device when the determined distance traveled reaches a first predetermined threshold.

[0010] According to the invention, the predetermined threshold for the measurable distance can be variably adjusted via an input device. This allows the sensitivity of the handle device, i.e., the starting point after moving the lever element, to be adjusted by the user to individual needs.

[0011] According to an advantageous embodiment of the present invention, it is possible for the second position of the signal transmitter to be arranged in a direction below the first position of the signal transmitter, so that the path traveled by the signal transmitter in that direction can be determined. This ensures that a downward movement of the handle device, i.e., in the direction of the tool, activates the drive.

[0012] Further advantages become apparent from the following description of the figures. The figures illustrate various embodiments that facilitate understanding of the method according to the invention.

[0013] In the figures, identical and similar components are numbered with the same reference symbols. They show: Figure 1 is a schematic front view of a machine tool in the form of a chisel hammer with a handle; Figure 2 is a detailed view of the handle in a first position according to a first embodiment; Figure 2 is a detailed view of the handle in a second position according to the first embodiment; Figure 2 is a detailed view of the handle in a third position according to the first embodiment; Figure 3 is a detailed view of the handle in a first position according to a second embodiment; Figure 3 is a detailed view of the handle in a second position according to the second embodiment; Figure 3 is a detailed view of the handle in a third position according to the second embodiment;Figure 4a shows a detailed view of the handle device in a first position according to a third embodiment; Figure 4b shows a detailed view of the handle device in a second position according to the third embodiment; and Figure 4c shows a detailed view of the handle device in a third position according to the third embodiment. Examples of implementation:

[0014] Figure 1 Figure 1 shows a machine tool in the form of a chisel hammer. However, the machine tool 1 can also be designed in the form of a rotary hammer, a drill, a saw, a grinding machine, or the like.

[0015] As in Figure 1As indicated, the machine tool 1, designed as a chisel hammer, essentially comprises a housing 2, a drive 3, a control device 4, a first and second handle device 5, a transmission device 6, a power supply device 7 and a tool holder 8.

[0016] The drive 3, the control unit 4, and the transmission unit 6 are essentially located inside the housing. The drive 3 is designed as an electric motor. This electric motor can be a brushless electric motor.

[0017] The tool holder 8 is positioned at one lower end of the housing 2 of the machine tool 1. A tool 9 can be picked up and held using the tool holder 8. In the figures, the tool 9 is designed as a chisel.

[0018] Furthermore, the power supply unit 7 is provided on the first side wall 2a of the housing 2 of the machine tool 1. In the example given for the machine tool 1, the power supply unit 7 consists of a mains connection and a mains cable. A free end of the mains cable can be connected to a mains connection (also called a socket). With the help of the power supply unit 7, the machine tool 1 and in particular the drive 3, which is designed as an electric motor, can be supplied with energy, for example, electrical energy.

[0019] According to an alternative design of the machine tool 1, the power supply unit 7 can also be designed as a single accumulator or as several accumulators: With the help of one or more battery interfaces, the single or multiple accumulators are positioned on or in the housing 2 of the machine tool 1.

[0020] As mentioned above, the drive 3 in the present embodiment of the machine tool 1 is designed as an electric motor. Alternatively, the drive 3 can also be an internal combustion engine. In this case, the energy supply unit 7 is designed as a fuel tank.

[0021] According to another alternative embodiment of the machine tool 1, the drive 3 can also be designed in the form of a pneumatic drive or compressor. In this case, the energy supply device 7 can be a compressed air connection or compressed air reservoir on or in the machine tool 1.

[0022] The drive 3, designed as an electric motor, serves to generate torque. With the aid of the transmission device 6, the torque generated by the drive 3 can be transmitted in the form of (hammer) blows to the tool holder 8 and finally to the tool 9, designed as a chisel. The transmission device 6 can also be referred to as a percussion mechanism. The higher the frequency of the blows, the more impact energy is generated.

[0023] The control unit 4 is connected to the first and second handles 5 and to the drive 3. Signals and communication data can thus be sent and received between the handles 5, the drive 3, and the control unit 4. The control unit 4 serves to control and regulate the various functions of the machine tool 1 and, in particular, to set the parameters or operating parameters of the drive 3. With the aid of the control unit 4, the speed of the drive 3, which is designed as an electric motor, can specifically be set as a parameter or operating parameter.

[0024] The first handle device 5 is movably positioned on a first side wall 2a of the housing 2, and the second handle device 5 is movably positioned on a second side wall 2b of the housing 2. As shown in Figure 1 and 2As shown, both the first and second handle devices 5 each contain a lever element 10 and a handle 11. The respective lever element 10 of the first and second handle devices 5 is pivotably mounted about a corresponding first pivot point D1 in the direction of rotation C or D. The first and second handle devices 5 serve to hold and guide the machine tool 1 by a user. The user is not shown in the figures.

[0025] In the Figures 3a to 3c The handle device 5 is shown in the form of a first embodiment. The handle device 5 according to the first embodiment essentially comprises a lever element 10, a handle 11, an activation element 12, a sensor device 13 and a signal transmitter 14.

[0026] The activation element 12, designed as an actuating switch, serves to activate the drive 3 of the machine tool 1. The activation element 12 can be reversibly moved from a first position to a second position by applying a force in direction S. Figure 3a The activation element 12 is shown in the first position, i.e., in an unpressed state. The first position corresponds to the uppermost position. The drive 3 is activated as soon as the activation element 12 is moved from the first position to the second position. Figure 3b and 3cThe activation element 12 is shown in its second position, i.e., in a pressed state. The activation element 12 is connected to the control unit 4 in such a way that signals can be exchanged between the two. The connection between the activation element 12 and the control unit 4 is not shown in the figures. The respective position, i.e., the first or second position, of the activation element 12 is transmitted to the control unit 4 by means of a corresponding signal. When the activation element 12 is in the second position, only the drive 3 of the machine tool 1 is activated. The transmission device 6, designed as a percussion device, is not only activated or started by pressing the activation element 12 in the direction of arrow S.

[0027] The sensor device 13 is connected to the control device 4 in such a way that signals, data and information can be exchanged between the sensor device 13 and the control device 4.

[0028] The lever element 10 is essentially designed as an elongated lever arm with a first end 10a and a second end 10b, as well as upper and lower surfaces 10c and 10d. The lever element 10 is mounted to the housing 2 of the machine tool 1 via a first pivot point D1, allowing it to pivot reversibly in a direction of rotation C or D. When a force in direction A is applied to the upper surface 10c of the lever element 10, the lever element 10 pivots about the pivot point D1 in the direction of rotation C. When no force is applied to the upper surface 10c of the lever element 10, the lever element 10 pivots about the first pivot point D1 back to its initial position in the direction of rotation D by means of a first spring element 15. The first spring element 15 can be designed in the form of a coil spring or a torsion bar spring.

[0029] The signal transmitter 14 is permanently connected to the lever element 10 and is designed in the form of a magnet. The magnet can be a permanent magnet. As shown in the Figures 3a to 3c The signal transmitter 14, designed as a magnet, is shown positioned on the lever element 10. By positioning it on the lever element 10, the signal transmitter 14 can be moved relative to the housing 2 of the machine tool 1.

[0030] The sensor assembly 13 is positioned on the first side wall 2a of the housing 2 of the machine tool 1 and essentially comprises a first, second and third Hall sensor 16a, 16b, 16c. As shown in the Figures 3a to 3cAs shown, the three Hall sensors 16a, 16b, 16c are positioned one below the other in direction A on the housing 2 of the machine tool 1. The Hall sensors 16a, 16b, 16c are positioned on the housing 2 of the machine tool 1 such that at least one of the three Hall sensors 16a, 16b, 16c can always detect the position of the signal transmitter 14, which is designed as a magnet, when the lever element 10 is pivoted in the direction of rotation C or D.

[0031] According to an alternative design, more or fewer than three Hall sensors can also be provided.

[0032] As mentioned above, in Figure 3aThe activation element 12 is not pressed in direction A, and the handle 5 is not pivoted in direction C by the application of a force. The first (i.e., uppermost) Hall sensor 16a of the sensor device 13 detects the proximity of the signal transmitter 14, which is designed as a magnet. The sensor device 13 sends a corresponding signal to the control device 4 to inform the control device 4 that no force is being applied to the handle 5. In this state, neither the drive 3 nor the transmission device 6 is activated. Consequently, no impact energy is transferred to the tool 9. For example, a tool change could be carried out safely in this state.

[0033] In Figure 3bA first force is exerted in direction A on the activation element 12 and the handle device 5. This moves the activation element 12 from the first position to the second position. The drive 3 is then activated. Simultaneously, the force exerted in direction A pivots the handle device 5, and thus the lever element 10, about the first pivot point D1 in the direction of rotation C. Figure 3bSufficient force is exerted on the handle 5 and the lever element 10 to place the handle 5 in a neutral position. The signal transmitter 14, designed as a magnet, is positioned so that the second (central) Hall sensor 16b of the sensor unit 13 can detect the magnet. The sensor unit 13 thus detects that the handle 5 is in a neutral position. When the sensor unit 13 detects the neutral position of the handle 5 with the aid of the second Hall sensor 16b, a corresponding signal is sent to the control unit 4. This signal informs the control unit 4 that a medium force is being exerted by the user on the handle 5.The control unit 4 controls the drive 3, which is designed as an electric motor, such that a first speed for the drive 3 is set depending on the average force applied to the handle 5. This first speed transfers an initial amount of impact energy from the transmission device 6 to the tool 9.

[0034] In Figure 3c A second force is exerted on the handle device 5 in direction A. The second force is greater than the first force. As in Figure 3c The activation element 12 is clearly still in the second (i.e., pressed) position. The drive 3 remains activated by pressing the activation element 12 in direction S. By applying the second (i.e., increased) force in direction A to the handle device 5, the lever element 10 is moved further than in Figure 3bThe lever element 10 is pivoted in the direction of rotation C. The lever element 10 is pivoted until the signal transmitter 14, positioned on the lever element 10, is at the level of the third (i.e., lowest) Hall sensor 16c. The sensor device 13 thus detects that maximum pressure is being exerted on the handle 5 and that the handle 5 is in a lower (i.e., lowest) position. When the sensor device 13, with the aid of the third Hall sensor 16c, detects the lowest position of the handle 5, a corresponding signal is sent to the control device 4. This signal informs the control device 4 that the user is exerting maximum force on the handle 5. The control device 4 then controls the drive 3, which is designed as an electric motor, such that a second speed for the drive 3 is set depending on the maximum force exerted on the handle 5.The second rotational speed is higher than the first. This second rotational speed transfers a second value of impact energy from the transmission device 6 to the tool 9. This second value of impact energy is higher than the first value of impact energy.

[0035] In the Figures 4a to 4c The handle device 5 is shown in the form of a second embodiment. The handle device 5 according to the second embodiment essentially comprises a lever element 10, a handle 11, an activation element 12, a sensor device 13, and a signal transmitter 14.

[0036] As in the Figures 4a to 4cIn contrast to the handle device 5 according to the first embodiment, in the second embodiment the activation element 12 and the signal transmitter 14 are positioned on a connecting element 17. The connecting element 17 is essentially elongated and has a first and second end 17a, 17b. The activation element 12 is positioned at the first end 17a and the signal transmitter 14 is positioned at the second end 17b of the connecting element 17.

[0037] Additionally, a pivot bearing is provided at the first end 17a of the connecting element 17, so that the connecting element 17 can be pivoted about a second pivot point D2 in the direction of rotation E or F. By applying a force in direction A to the activation element 12, the connecting element 17 is pivoted or rotated about the pivot point D2 in the direction of rotation E.

[0038] When the connecting element 17 is pivoted about the pivot point D2 in the direction of rotation E, the signal transmitter 14 positioned at the second end moves in the direction of A. The signal transmitter 14, which is designed as a magnet, is thus moved past the three Hall sensors 16a, 16b, 16c of the sensor device 13.

[0039] As mentioned above, the sensor device 13 detects the position of the signal transmitter 14, which is designed as a magnet. The angle of the handle 5 and the force with which the handle 5 is pressed in direction A can be determined from the position of the signal transmitter 14 relative to the sensor device 13. As also mentioned above, the rotational speed of the drive 3, and thus the delivery of impact energy from the transmission device 6 to the tool 9, is adjusted depending on the position of the signal transmitter 14 or the position of the lever element 10 relative to the sensor device 13 or the housing 2 of the machine tool 1.

[0040] When no force or pressure is exerted on the activation element 12 in direction A, the activation element 12 moves back to its starting position in direction B with the aid of a second spring element. The connecting element 17 is pivoted around pivot point D2 in the direction of rotation F with the aid of the second spring element. The second spring element is not shown in the figures.

[0041] In the Figures 2a to 2c The handle device 5 is shown in the form of a third embodiment. The handle device 5 according to the third embodiment essentially comprises a lever element 10, a handle 11, an activation element 12, a sensor device 13, and a signal transmitter 14.

[0042] The design of the handle device 5 according to the third embodiment is similar to that of the handle device 5 according to the first embodiment. The handle device 5 according to the third embodiment differs from the handle device 5 according to the first embodiment in that the sensor device 13 contains only one 3D sensor instead of a first, second, and third Hall sensor 16a, 16b, 16c. Alternatively, the sensor device can also contain more than one 3D sensor.

[0043] The 3D sensor can also be referred to as a TOF camera (= Time Of Flight camera) and / or PMD sensor (= Photomixing detector).

[0044] In order for the control unit 4 to switch the drive 3 from a deactivation mode to an activation mode, the sensor unit 13 must detect a sufficiently large pivoting movement of the lever element in the direction of rotation C relative to the housing 2 of the machine tool 1. An insufficiently large pivoting movement of the lever element in the direction of rotation C relative to the housing 2 of the machine tool 1 will not activate the drive 3.

[0045] As described above, applying a force in direction S moves the lever element 10 downwards. The signal transmitter 14, positioned on the lever element 10, moves past the sensor device 13. The sensor device 13 detects the first and second positions of the signal transmitter 14. These detected positions are sent to the control device 4. The control device 4 uses the position data of the signal transmitter 14 relative to the sensor device 13 to determine the distance between the first and second detected positions. If this distance corresponds to at least a predetermined threshold, the drive 3 is activated with a starting rotational speed. The control device 4 compares the determined distance with the predetermined threshold.

[0046] The predetermined threshold values ​​for the determined distance between the two detected positions are stored in the control unit 4 using a look-up table. Reference symbol list

[0047] 1 Machine tool 2 Housing 2 First side of housing 2b Second side of housing 3 Drive 4 Control device 5 Handle device 6 Transmission device 7 Power supply device 8 Tool holder 9 Tool 10 Lever element 10 First end of lever element 10b Second end of lever element 10c Top of lever element 10d Bottom of lever element 11 Handle 12 Activation element 13 Sensor device 14 Signal transmitter 15 First spring element 16a First Hall sensor 16b Second Hall sensor 16c Third Hall sensor 17 Connecting element 17a First end of connecting element 17b Second end of connecting element

Claims

1. Method for controlling and regulating a machine tool (1), in particular a chipping hammer, comprising a drive (3), a control device (4), a sensor device (13), a transmission device (6), and a handle apparatus (5), the handle apparatus (5) containing a lever element (10) having a signal transmitter (14), which lever element is pivotable relative to the sensor device (13), comprising the method steps of - detecting a first and second position of the signal transmitter (14) by the sensor device (13); - determining a distance traveled by the signal transmitter (14) from the first position to the second position by the control device (4); and - adjusting the drive (3) from a deactivation mode to an activation mode by the control device (4) when the determined distance traveled reaches a first predetermined threshold, characterized in that the predetermined threshold for the determinable distance traveled can be variably adjusted via an input device.

2. Method according to claim 1, characterized in that the second position of the signal transmitter (14) is arranged, in a direction (A), below the first position of the signal transmitter (14), so that the distance traveled by the signal transmitter (14) in the direction (A) can be determined.