JP2015009361A - Hand-held machine tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem of reducing a rotating speed of a driving unit, when a load peak is caused, and when an operation parameter reaches a maximum value.SOLUTION: A hand-held machine tool comprises an impact mechanism unit provided for forming an impact to a tip tool, the driving unit provided for driving the impact mechanism unit, a sensor unit for detecting at least one operation parameter and an electronic device having an open loop control and/or closed loop control unit for open loop-controlling and/or closed loop-controlling the driving unit on the basis of the operation parameter detected by the sensor unit. The hand-held machine tool is provided so that the open loop control and/or closed loop control unit adjust the rotating speed of the driving unit to a higher value just before the operation parameter reaches the maximum value on the basis of the operation parameter detected by the sensor unit.

Description

  A hand-held machine tool according to the superordinate concept of claim 1 has already been proposed.

  The present invention detects at least one operating parameter and, in particular, an impact mechanism unit provided to form an impact on the tip tool, at least a drive unit provided to drive the impact mechanism unit And an electronic device having an open loop control and / or a closed loop control unit for performing an open loop control and / or a closed loop control of at least the drive unit based on an operating parameter detected by the sensor unit , Assuming a hand-held machine tool equipped with.

  The open-loop control and / or the closed-loop control unit can at least partially determine the rotational speed of the drive unit based on the operating parameter detected by the sensor unit immediately before the at least one operating parameter reaches a maximum value. Provided to adjust to two higher values. The term “striking mechanism unit” is particularly relevant in the context of the present invention, at least in part, by converting the rotational motion of the drive unit of the hand-held machine tool into linear motion, in particular for the tip tool of the hand-held machine tool. It is to be understood that the unit is provided for creating a blow and / or for driving the tool in rotation in the operating state. The striking mechanism unit comprises, inter alia, at least one piston element, which is advantageously at least partly mechanically coupled to a drive unit that is preferably included in a hand-held machine tool. The piston unit is preferably provided for performing a linear movement in the operating state. The guide element is preferably formed by a hammer pipe, and more preferably is provided for linearly guiding the piston element. In a particularly advantageous embodiment, the striking mechanism unit includes a pneumatic striking mechanism.

  The term “drive unit” is understood in the context of the present invention to be a unit provided to drive a tip tool that is at least partially coupled with a hand-held machine tool in the operating state. I want. The term “provided” means, among other things, specially constructed, designed or equipped. The drive unit advantageously includes at least one electric motor. However, it is also conceivable to configure the drive unit to be driven at least partly pneumatically and / or in a manner that would be meaningful to the person skilled in the art. The term “electronic device” is provided in the context of the present invention, at least in the operating state of the hand-held machine tool, in particular for at least partly open-loop control and / or closed-loop control of the hand-held machine tool drive unit. It should be understood that this is a unit. Advantageously, the electric motor comprises at least one drive unit motor controller. The electronic unit preferably comprises, inter alia, at least one transistor, at least one capacitor, at least one processor, particularly preferably at least one field effect transistor (MOSFET), and / or especially an insulated gate electrode (IGBT). It has an electronic component such as at least one bipolar transistor.

  The term “sensor unit” means in particular in the context of the invention at least in part at least one chemical property and / or advantageously at least one physical property, in order to detect at least one parameter. Unit provided for detecting at least one operating parameter representing and / or comprising and converting it into an analog, binary and / or advantageously digital electrical signal, It should be understood that the unit is provided for supplying an open loop control and / or closed loop control unit of at least one electronic device. The sensor unit is advantageously at least one strain gauge, at least one microelectromechanical system (MEMS) sensor, in particular at least one gyro sensor, at least one piezoelectric sensor plate, and / or meaningful to the person skilled in the art. Other forms of at least one sensor element may be included. The term “operating parameter” is, in the context of the present invention, a parameter that exhibits and / or comprises at least one chemical characteristic and / or advantageously at least one physical characteristic, It should be understood that the parameters are configured based on the operating state of the mechanism unit.

  The term “open-loop control and / or closed-loop control” is used in the context of the present invention, in particular in a process that is at least partly independent of the operating state of the drive unit and / or the electronic unit, in particular at least partly rotation of the drive unit. A process separated from the number, this process at least partly actively affecting the operation of the hand-held machine tool, in particular the operation of the drive unit, and // in order to adapt and / or approximate the operation of the hand-held machine tool, in particular the operation of the drive unit, at least in part to a predetermined sequence and / or in particular dynamically changeable The operating parameters, in particular the operating parameters of the drive unit, preferably according to the algorithm, and It is provided in order to divide actively changed. The open-loop control and / or closed-loop control unit can in particular be at least partly mechanically configured, particularly preferably at least partly electronically configured. The open loop control and / or closed loop control unit preferably additionally comprises a calculation unit, in particular a memory unit in addition to the calculation unit. In the memory unit is stored an open loop control and / or a closed loop control program which is provided to be implemented by the calculation unit.

  The term “based on” means, in the context of the present invention, inter alia at least partly a direct relationship. The term “immediately before” refers, inter alia, in the context of the invention, to the open-loop control and / or the closed-loop control of the drive unit by means of the open-loop control and / or the closed-loop control unit and the reaching of a maximum value of at least one operating parameter. It should be understood that there is a time interval of 5 seconds or less, preferably 1 second or less, preferably 50 milliseconds or less, particularly preferably 10 milliseconds or less.

  The configuration of the hand-held machine tool according to the invention advantageously makes it possible to improve the energy efficiency of the hand-held machine tool and advantageously reduce the power consumption.

  Furthermore, the open loop control and / or the closed loop control unit includes at least one rotational speed control element. This makes it possible for the configuration of the open-loop control and / or the closed-loop control unit of the hand-held machine tool to be advantageously precise and reliable, and advantageously simple and low-cost.

  Furthermore, an open-loop control and / or a closed-loop control unit is provided, at least partly, for increasing the rotational speed of the drive unit just before the at least one operating parameter reaches a maximum value. In a particularly advantageous embodiment, when measuring the rotational speed, the average rotational speed can be calculated by a predetermined number of rotations of the drive spindle of the drive unit, in particular in the electric motor of the drive unit. The rotational speed of the drive unit is preferably accelerated or increased by an approximate and / or fixed predetermined value, which is preferably calculated from previous measurements. This advantageously reduces the difference between the normal operating speed and, in particular, the speed that decreases due to load peaks, or the speed that decreases when at least one operating parameter reaches its maximum value. It can be made smaller. This further advantageously makes it possible to lower the target value for the normal operating speed and thus to reduce the thermal load in at least a partial region of the hand-held machine tool. This further allows the maximum value of the current intensity consumed by the drive unit in the operating state, in particular at the load peak, to be advantageously reduced and kept low. In this way it is possible advantageously to reduce losses. In calculating this loss, the current intensity is taken into account in particular by the square.

  Furthermore, the at least one operation parameter detectable by the sensor unit includes at least a load characteristic amount of the striking mechanism unit. The term “load characteristic quantity” is a parameter of the striking mechanism unit, particularly in the context of the present invention, which acts on the striking mechanism unit in the operating state, and in particular on the driving unit. It should be understood that the parameters are formed directly on the basis of the load. This advantageously allows the configuration of the hand-held machine tool of the present invention to be efficient, reliable and high output.

  Furthermore, the at least one operating parameter detectable by the sensor unit includes at least the striking frequency of the striking mechanism unit. The term “striking frequency” is, in the context of the present invention, among other things, a physical characteristic quantity which is transmitted at least in part by the striking mechanism unit to the tip tool within a predetermined time interval. It should be understood that this is a characteristic quantity representing the number of pulses. This advantageously makes it possible to increase the single striking energy and thus advantageously make the construction of the hand-held machine tool efficient.

  Furthermore, the electronic device has an evaluation unit which is provided for evaluating the transition of at least one operating parameter. The term “evaluation” is used in the context of the present invention to be a process in which at least one operating parameter, or in particular a temporal transition of at least one operating parameter, is checked or processed, in particular open-loop control and / or It should be understood that this is a process that is analyzed based on a closed loop control algorithm. The term “transition” is to be understood in particular in the context of the present invention as a temporal sequence of individual values of at least one operating parameter. This advantageously allows precise open-loop control and / or closed-loop adjustment of the hand-held machine tool, and advantageously improves operational comfort.

  Furthermore, an evaluation unit is provided for at least approximately estimating the time point of the maximum value of the at least one operating parameter before the at least one operating parameter reaches the maximum value. The term “approximately estimated” means, inter alia, in the context of the invention, that the calculated maximum value is notably less than 1 second, preferably less than 50 milliseconds, preferably less than 10 milliseconds, particularly advantageous. Should be understood to be different from the actual maximum point in time by less than 5 milliseconds. This makes it possible to control the hand-held machine tool with particularly precise open-loop and / or closed-loop control.

  Furthermore, an electronic device for a hand-held machine tool according to the invention is proposed.

  The invention further presupposes a method for open-loop control and / or closed-loop control of a drive unit of a hand-held machine tool according to the invention using an open-loop control and / or a closed-loop control unit. The method is based on at least one step of detecting at least one operating parameter by the sensor unit and on the basis of the operating parameter detected by the sensor unit, immediately before the at least one operating parameter reaches a maximum value. At least one additional step of adjusting the number of revolutions to a higher value.

  Furthermore, the method at least partly evaluates the transition of the at least one operating parameter detected by the sensor unit and determines the maximum value of the at least one operating parameter before the at least one operating parameter reaches the maximum value. Having at least one further step of at least approximately estimating the time.

  The hand-held machine tool according to the present invention should not be limited to the application methods and embodiments described above. In particular, the hand-held machine tool of the present invention can have a different number of individual elements, components, units than the number listed herein to achieve the functional scheme described herein.

  Further advantages will become apparent from the following detailed description of the drawings. The drawings illustrate one embodiment of the present invention. The drawings, the description, and the claims include numerous combinations of features. A person skilled in the art could either capture these features individually according to their purpose, or integrate them into another more meaningful combination.

It is a schematic side view of the hand-held machine tool of the present invention. It is a schematic block diagram of a part of the hand-held machine tool of the present invention having an electronic device, a drive unit, and a striking mechanism unit. It is the diagram which illustrated the rough transition of the rotation speed of the drive unit of the hand-held machine tool of this invention. 4 is a schematic flowchart of a method for performing open-loop control and / or closed-loop control of a drive unit of a hand-held machine tool according to the present invention.

  FIG. 1 shows a hand-held machine tool 10 constituted by a drill hammer. However, other forms of hand-held machine tool 10 that would be significant to those skilled in the art are also conceivable, such as impact drills, chipping hammers, dismantling hammers, saver saws or jigsaws. The hand-held machine tool 10 is an electric hand-held machine tool. A tool storage 34 is arranged in the front region of the hand-held machine tool 10 and is provided in particular for receiving the tip tool 14 which is an attachment-type drill or chisel. A sub-hand grip 36 is further arranged in the front area of the hand-held machine tool 10, and a main hand grip 38 is arranged on the side opposite to the front area of the hand-held machine tool 10. It is possible to operate the hand-held machine tool 10 via this. The sub-hand grip 36 is formed in a rod shape. The main hand grip 38 is formed in a U shape. However, other forms of main handgrip and / or subhandgrip that would be meaningful to one skilled in the art are also contemplated. The main hand grip 38 is provided with a switch element 40 that can be operated by an operator. The switch element 40 is provided for operating the drive unit 16. The casing 42 of the hand-held machine tool 10 surrounds a drive unit 16 (not shown in detail) constituted by an electric motor that can be operated using the switch element 40. The drive unit 16 is provided to drive the striking mechanism unit 12 of the hand-held machine tool 10.

  The hand-held machine tool 10 includes an impact mechanism unit 12. The striking mechanism unit 12 is provided to form a striking (impact) against the tip tool 14 held in the tool accommodating portion 34. The striking mechanism unit 12 is provided to drive the tip tool 14 held in the tool accommodating portion 34 of the hand-held machine tool 10 in a translational or striking manner. The striking mechanism unit 12 not shown in detail includes a transmission element constituted by rivets. The transmission element is provided for transmitting a hit to the tip tool 14 in the hammer operating state and in the hit drilling operation state. The striking mechanism unit 12 further includes a guide element not shown in detail. The guide element is provided for guiding at least one transmission element in the operating state of the striking mechanism unit 12. The guide element is constituted by a hammer hole. The guide element is provided to guide the transmission element, the striking element, and the piston element linearly in parallel with the machining axis 44 of the tip tool 14 forming the axial direction 46 of the striking mechanism unit 12. It has been. In the guide element, the piston unit driven by the drive unit 16 is guided in the axial direction 46. The striking element is disposed behind the piston element in the axial direction when viewed from the drive unit 16 toward the tool housing portion 34. The striking element is likewise supported so as to be movable in the axial direction 46 in the guide element.

  The hand-held machine tool 10 further includes an electronic device 18. The electronic device 18 includes a sensor unit 20 for detecting an operation parameter, and an open loop control and / or a control unit for performing an open loop control and / or a closed loop control of the drive unit based on the operation parameter detected by the sensor unit 20. And a closed loop control unit 22 (FIG. 2). The open-loop control and / or closed-loop control unit 22 is constituted by a closed-loop control unit 50 that is provided for closed-loop control of the drive unit on the basis of operating parameters detected by the sensor unit. Additionally, a sensor unit 20 can be provided for detecting one or more other operational parameters of the striking mechanism unit 12 and / or one or more ambient parameters. The sensor unit 20 has a sensor element 48 for detecting operating parameters. The sensor element 48 of the sensor unit 20 is configured by an acceleration sensor. However, other forms of the sensor element 48 of the sensor unit 20 that are meaningful to those skilled in the art are also conceivable. The operation parameters that can be detected by the sensor unit 20 of the electronic device 18 include the load characteristic amount of the striking mechanism unit 12. The operation parameter that can be detected by the sensor unit 20 of the electronic device 18 is configured by the striking frequency of the striking mechanism unit 12. The operating parameters are based on the operating state of the striking mechanism unit 12 and the associated driving unit load. When the striking mechanism unit 12 shifts from the no-load operation to the hammer operation state or the perforation operation state, a load peak occurs in the drive unit 16. In addition, the operating parameters of the striking mechanism unit 12 reach a maximum value. As the load increases at the load peak, the rotational speed of the drive unit 16 decreases.

  The electronic device 18 of the hand-held machine tool 10 further includes an evaluation unit 26. The evaluation unit 26 is electronically connected to the sensor unit 20. An evaluation unit 26 is provided for evaluating the transition of the operating parameters. The evaluation unit 26 is provided for at least approximately estimating when the operating parameter reaches a maximum value. This operating parameter constituted by the striking frequency of the striking mechanism unit 12 is detected by the sensor unit 20 and transferred to the evaluation unit 26. The operating parameters are transferred digitally to the evaluation unit 26. However, it is also conceivable to transfer the operating parameters to the evaluation unit 26 in analog form or in another form that would be meaningful to the person skilled in the art. The operating parameters are transmitted to the evaluation unit 26 via a data cable. However, it is also conceivable to transmit wirelessly, for example via radio, in another form that would be meaningful to those skilled in the art.

  The evaluation unit 26 evaluates the transition of the operation parameter detected by the sensor unit 20 based on the evaluation algorithm stored in the evaluation unit 26. By the evaluation using the evaluation algorithm of the evaluation unit 26, the time when the drive unit 16 reaches the load peak, that is, the time when the operation parameter of the hitting mechanism unit 12 reaches the maximum value, before the operation parameter reaches the maximum value. Can be approximately determined. As soon as the evaluation unit 26 determines when the operating parameter reaches the maximum value, the evaluation unit 26 forwards a signal with corresponding information to the closed-loop control unit 50 of the electronic device 18. For this purpose, the evaluation unit 26 is electronically connected to the closed loop control unit 50. This signal with corresponding information is transferred digitally to the closed loop control unit 50. However, it is also conceivable to transfer this signal with corresponding information to the closed-loop control unit 50 in analog or another form that would be meaningful to those skilled in the art. This signal with corresponding information is transmitted to the closed loop control unit 50 via a data cable. However, it is also conceivable to transmit wirelessly, for example via radio, in another form that would be meaningful to those skilled in the art.

  The closed loop control unit 50 includes a microcontroller. The closed loop control unit 50 of the electronic device 18 is electronically connected to the drive unit 16. The closed loop control unit 50 includes a rotation speed controller 24. The closed loop control unit 50 is provided for performing closed loop control on the rotational speed of the drive unit 16. For this purpose, the closed loop control unit 50 is electronically coupled to the drive unit 16. The closed loop control unit 50 is coupled to the drive unit 16 in both directions. The actual rotational speed value of the drive unit 16 is transmitted from the drive unit 16 to the closed loop control unit 50. In the closed loop control unit 50, the actual rotational speed value of the drive unit 16 is compared with a predetermined target value of the rotational speed of the drive unit 16. The closed-loop control unit 50 calculates a control signal for bringing the actual rotational speed value of the drive unit 16 close to a predetermined rotational speed target value. Thereafter, this control signal for adjusting the value of the rotational speed of the drive unit 16 to the target value of the rotational speed is transferred from the closed loop control unit 50 to the drive unit 16, whereby the drive unit 16 is controlled in a closed loop.

  The control signal and the actual rotational speed value of the drive unit 16 are transmitted digitally between the drive unit 16 and the closed loop control unit 50. However, it is also possible to transmit the control signal and the value of the actual speed of the drive unit 16 between the drive unit 16 and the closed loop control unit 50 in an analog manner or in another form that would be meaningful to those skilled in the art. Conceivable. The control signal and the value of the actual rotational speed of the drive unit 16 are transmitted between the drive unit 16 and the closed loop control unit 50 via a data cable. However, it is also conceivable to transmit wirelessly, for example via radio, in another form that would be meaningful to those skilled in the art. As an alternative or in addition, it is also conceivable for the electronic device 18 to comprise an open-loop control unit provided for open-loop control of the drive unit 16 based on the operating parameters detected by the sensor unit 20. In addition, it is also conceivable to provide a closed loop control unit 50 for manual adjustment, for example using an adjustment button or an adjustment wheel operable by the operator.

  The closed loop control unit 50 is configured to perform the closed loop control of the drive unit 16 immediately before the operation parameter reaches the maximum value based on the operation parameter detected by the sensor unit 20. The closed-loop control unit 50 further adapts the target value for the rotational speed based on a signal sent from the evaluation unit 26 to the closed-loop control unit 50 with corresponding information regarding when the operating parameter reaches its maximum value. In this way, the target value of the rotational speed is increased to the maximum target value immediately before the operating parameter reaches the maximum value, whereby the control signal transmitted from the closed loop control unit 50 to the drive unit 16 is changed to the drive unit 16. The number of revolutions is increased accordingly. The closed loop control unit 50 is provided to increase the rotational speed of the drive unit 16 immediately before the operating parameter reaches the maximum value. When the load peak occurs and when the operating parameter reaches the maximum value, the rotational speed of the drive unit 16 decreases. By previously increasing the rotational speed of the drive unit 16 by means of the closed loop control unit 50, the difference between the rotational speed value, which decreases due to the load peak, and the average operating rotational speed is advantageously kept small. (Fig. 3).

After exceeding the time t _S of the load peak, the rotational speed of the drive unit 16 is raised again, thus the closed-loop control unit 50 may reduce the maximum target value again to the normal target value. The normal target value of the closed loop control unit 50 corresponds to the average operation speed of the drive unit 16. The closed loop control unit 50 further maintains the value of the rotational speed of the drive unit 16 in the operating state of the hand-held machine tool 10 at an average operating rotational speed value at least approximately constant during the period between the two load peaks. Or it is usually provided to maintain the target value.

  Closed loop control of the drive unit 16 of the hand-held machine tool 10 is implemented by a method that includes the step 28 of detecting operating parameters by the sensor unit 20. The method further forwards the operating parameters detected by the sensor unit 20 to the evaluation unit 26, evaluates the transition of the operating parameters detected by the sensor unit 20 by the evaluation unit 26, and determines a maximum value of at least one operating parameter. Another method step 32 is to estimate the time instant at least approximately before the operating parameter reaches the maximum value. This information is transmitted to the closed loop control unit 50. This method has another method step 30 based on the operating parameter detected by the sensor unit 20 to control the drive unit 16 in a closed loop just before the operating parameter reaches its maximum value. In this other method step 30 of the method, the time is determined by the evaluation unit 26 based on the point in time when the operating parameter reaches the maximum value, as well as the predetermined normal target value of the drive unit 16. Based on the maximum target value, the closed loop control unit 50 performs the closed loop control. However, it is also conceivable that this method has alternative or additional steps that would be meaningful to those skilled in the art.

Claims (10)

In particular, a striking mechanism unit (12) provided to form a striking against the tip tool (14);
A drive unit (16) provided to drive at least the striking mechanism unit (12);
A sensor unit (20) for detecting at least one operating parameter, and at least the drive unit (16) based on the operating parameter detected by the sensor unit (20). An electronic device (18) having an open loop control and / or a closed loop control unit (22) for
In a hand-held machine tool comprising
The open-loop control and / or closed-loop control unit (22) is at least partly based on the operating parameter detected by the sensor unit (20) and immediately before the at least one operating parameter reaches a maximum value. In order to adjust the rotational speed of the drive unit (16) to at least one higher value,
Hand-held machine tool characterized by that. The open-loop control and / or closed-loop control unit (22) is provided for increasing the rotational speed of the drive unit (16) at least partly immediately before the at least one operating parameter reaches a maximum value. Being
The hand-held machine tool according to claim 1. The open loop control and / or closed loop control unit (22) includes at least one rotational speed control element (24),
The hand-held machine tool according to claim 1 or 2. The at least one operating parameter detectable by the sensor unit (20) includes at least a load characteristic amount of the hitting mechanism unit (12).
The hand-held machine tool according to any one of claims 1 to 3, wherein: The at least one operating parameter detectable by the sensor unit (20) includes at least a striking frequency of the striking mechanism unit (12);
The hand-held machine tool according to any one of claims 1 to 4, wherein: The electronic device (18) comprises an evaluation unit (26) provided for evaluating the transition of the at least one operating parameter.
The hand-held machine tool according to any one of claims 1 to 5, wherein The evaluation unit (26) is provided for at least approximately estimating the time point of the maximum value of the at least one operating parameter before the at least one operating parameter reaches a maximum value.
The hand-held machine tool according to claim 6.   Electronic device of a hand-held machine tool (10) according to any one of the preceding claims. The drive unit (16) of the hand-held machine tool (10) according to any one of claims 1 to 7 is open-loop controlled and / or closed-loop controlled using an open-loop control and / or closed-loop control unit (22). In the method
At least one step (28) for detecting at least one operating parameter by the sensor unit (20);
Based on the operating parameter detected by the sensor unit (20), at least one adjusting the rotational speed of the drive unit (16) to a higher value immediately before the at least one operating parameter reaches a maximum value. Another step (30);
A method characterized by comprising: A transition of at least one operating parameter detected by the sensor unit (20) is at least partially evaluated by an evaluation unit (26), and the at least one operating parameter is reached before the at least one operating parameter reaches a maximum value. At least one further step (32) for at least approximately estimating the time point of the maximum value of the two operating parameters.
10. The method of claim 9, comprising:

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