CN106270770B

CN106270770B - Hand-held reciprocating saw

Info

Publication number: CN106270770B
Application number: CN201610499716.XA
Authority: CN
Inventors: A·D·尼科兰托尼奥
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2015-06-29
Filing date: 2016-06-29
Publication date: 2020-12-25
Anticipated expiration: 2036-06-29
Also published as: CN106270770A; DE102015212079A1

Abstract

The invention relates to a hand-held reciprocating saw (10) having a saw blade (14) and a sensor (35) for sensing a deflection (38) of the saw blade (14), in particular a deflection of the saw blade (14) in a saw cut (16), and having at least one actuator (37). It is proposed that the actuator (37) counteracts deflection (38) of the saw blade (14), in particular deflection of the saw blade (14) in the sawing means (16).

Description

Hand-held reciprocating saw

Technical Field

The present invention relates to a hand-held jigsaw.

Background

Hand-held reciprocating saws have been disclosed, for example in the form of jig saws or saber saws. In order to keep the cutting work low and the reciprocating saw compact, a typically flexible saw blade is implemented narrower. This disadvantageously promotes uncontrolled and undesired deflection of the saw blade in the workpiece to be machined.

A hand-held reciprocating saw with a working device embodied as a saw blade and with a sensor for sensing the deflection of the saw blade in the saw cut is already known from DE 69023132T 2. The device is visual to the user with the saw bit off tracking, and the user can then carry out corresponding rectification action when the guide reciprocating saw.

A reciprocating saw is also known from DE 102008002066 a1, which is provided with a displaceable transverse guide in order to avoid wandering.

Disclosure of Invention

The invention relates to a hand-held reciprocating saw having a working device embodied as a saw blade and having a sensor for sensing deflection of the saw blade in a saw cut and having at least one actuator.

It is proposed here that: the at least one actuator counteracts deflection of the saw blade, in particular deflection of the saw blade in the sawing object. A hand-held reciprocating saw is to be understood as meaning, for example, a jigsaw, a saber saw, a garden saw, a pruning saw or other saws in which the working device performs primarily a reciprocating linear movement. The hand-held reciprocating saw is driven by a motor, such as an internal combustion engine or a motor. A sensor is understood to mean, for example, singly or in combination, at least one inductive sensor, force sensor, strain gauge sensor, optical sensor, laser sensor or resistance sensor, rotational speed sensor and/or other sensor which detects the deflection of the saw blade at least indirectly. The sensor may be disposed on a component of the reciprocating saw or on an attachment. But it may also be an external sensor, wired to the blade, and/or connected via wireless data technology. An actuator is understood to mean, for example, at least one actuator which operates piezoelectrically, hydraulically, pneumatically, linearly, servomotors, electromagnetically and/or electromechanically. Off tracking is understood to mean an undesired sawing situation of the saw blade in which the saw blade is bent elastically substantially transversely to the sawing direction, so to speak like a bent beam clamped on one side. In addition, the saw blade may twist when running off the track. In the deflected state, the saw blade is displaced by a greater distance relative to a vertical axis extending through the saw blade receiving device or the reciprocating device, as the distance from the clamping or receiving point increases.

The cutting quality can advantageously be increased by means of actuators which counteract deflection. By sensing the off-tracking with the sensor and causing a correction to the off-tracking with the actuator, the saw blade can react to the starting off-tracking as early as possible. Wear, which is usually caused by deflection, on the reciprocating saw or on parts of the reciprocating saw, in particular on the saw blade, the blade receiver or the drive train, is avoided. The scrap and scrap of the sawn objects is advantageously reduced and the quality of the cut is improved.

In one embodiment of the invention, the following are proposed: the sensor detects deflection of the saw blade, in particular in the saw blade in the drive train of the reciprocating saw, in particular within the transmission and/or the motor of the drive train, and/or directly in or on the saw blade. The drive train is preferably understood to mean all components of the reciprocating saw which generate or transmit a rotary motion, an oscillating motion or a reciprocating linear motion. These components may be, for example, motors, transmissions, clutches, pendulous devices or reciprocating linear devices, etc. For example, a rotation angle or rotational speed measuring sensor can be arranged on the motor shaft or on the transmission shaft for torque reception, a force sensor can be arranged on the reciprocating lever of the reciprocating linear motion device or on the receiving part of the wobble feed device, and the like. "arranged directly in or on the saw blade" is understood to mean, for example, that the saw blade is integrated with sensors which receive, for example, a twist and/or a bend or a deflection of the saw blade, for example, by means of strain gauges. Reference may be made to document DE 102006007616 a1 by the expert of sensors with regard to possible arrangements in the tool and potential use. The solutions proposed therein as well as the sensor arrangement and the actuator arrangement should likewise be understood to belong to the disclosure of the present invention. However, sensors can also be arranged in the blade receiver, in the base plate or in the pivoting guide of the reciprocating saw, which sensors can sense the deflection of the saw blade, for example, in a contact-type manner, inductively and/or by means of force measurement.

The sensor may be more advantageously received in a secure package and reduce the risk of accidental damage, particularly for otherwise open sensors. For this purpose, sensors that are already present at times, for example torque sensors in the drive train, can be used, so that costs can be saved. The sensor can also be provided particularly advantageously by a control or regulating device of the reciprocating saw, for example, by sensing the current consumption and/or calculating the current torque or drive force therefrom, comparing it with a setpoint value, in order to indirectly detect a deviation of the saw blade in the saw work if there is a deviation of the setpoint value from the actual value. It is also proposed: the at least one actuator is configured to cause, either alone or in combination, tilting of the reciprocating linear motion device relative to the reciprocating saw shoe, tilting of the entire reciprocating saw, and/or tilting of the reciprocating saw body of the reciprocating saw. "provided" is to be understood as specially designed and/or implemented and/or equipped. The clamped saw blade thus advantageously obtains an orientation, in particular a counter-orientation or an inclination, which compensates for the deflection.

It is furthermore proposed that the at least one actuator is provided for displacing the reciprocating saw, individually or in combination, relative to the saw cut to be sawn, the reciprocating saw body relative to the base plate and/or the reciprocating linear motion device within the reciprocating saw transversely to the vertical axis of the reciprocating saw. In the case of a displacement of the reciprocating saw relative to the sawing object to be sawn, the reciprocating saw has, for example, on its base plate, actuators, such as wheels, feet, arms and the like, which are supported, potentially in particular, displaceably, on the workpiece. The actuator preferably has a surface relative to the workpiece that adheres better than a base plate surface that is more slippery. In the case of a displacement of the reciprocating saw body relative to its base plate, the base plate can be fixed on the reciprocating saw body, for example, by means of a joint and the like, so as to be at least laterally displaceable. In the case of a displacement of the reciprocating linear motion device, the displacement is effected relative to a reciprocating saw housing which at least partially contains the reciprocating linear motion device. This also advantageously corrects and/or prevents deflection.

Furthermore, it is proposed that the at least one actuator is provided for twisting the reciprocating saw relative to the saw piece to be sawn, the reciprocating saw body relative to the base plate and/or the reciprocating linear motion device within the reciprocating saw, in particular about a vertical axis of the reciprocating saw. This also advantageously corrects and/or prevents deflection. Depending on the severity and type of the deflection, it is thus possible to react appropriately to the deflection, for example only in the transverse direction and/or in the event of a twisting or twisting of the tool being introduced.

The invention also proposes: the at least one actuator introduces a force and/or a moment on the saw blade via at least one blade cross guide configured on the reciprocating saw. Transverse guides are to be understood as meaning, for example, at least blocks, jaws, rollers, actuating and/or guide elements, etc. They are capable of guiding the saw blade substantially transversely with respect to the sawing direction and/or of rotating the saw blade about its longitudinal axis. They act on the saw blade as close as possible to the workpiece to be machined. For example, the actuator can move hard metal blocks and the like arranged on the side of the saw blade: so that the hard metal block exerts a transverse force on the saw blade which serves to guide the saw blade back to its initial position. The transverse guide can also limit play of the saw blade in the transverse direction and/or in the longitudinal direction. The transverse guidance can directly or indirectly cause the saw blade to rotate. In this way, for example, an actuator acting on the wobble guide and/or the wobble roller can displace and/or rotate the saw blade. This advantageously makes it possible to apply a simple and directly acting deflection stabilization to the saw blade. The actuator can also preferably have a sensor. The sensor and the actuator formed by the transverse guide in this way can represent a cost-effective variant for preventing and/or compensating deflection on the reciprocating saw blade.

In another aspect of the invention, there is provided: the at least one actuator resists bending of the saw blade caused by deflection by affecting the bend line of the saw blade. For example, sensors and actuators may sense the bend line of the blade either internally or externally of the blade and resist deflection of the blade. This may be, for example, a piezoelectric sensor and/or an actuator. Inductive sensors are also contemplated. This advantageously allows undesired or desired deflection to be influenced and/or controlled in a targeted manner. For example, side cuts by deflection can be produced or avoided, in particular in certain cutting zone regions and/or saw blade regions. These sensors and/or actuators are preferably electrically connected to the control or regulating device of the hand-held reciprocating saw.

It is also proposed: the at least one actuator is configured for causing a change of at least one operating parameter of the reciprocating saw, in particular by changing the oscillation, the sawing or feed speed, the cutting volume and/or the number of reciprocations of the oscillating device. An alteration is understood to mean an increase or decrease, or an increase or decrease. Such an actuator can be embodied, for example, as a brake, in particular as a brake acting on the drive train and/or on the saw blade, as an activatable drive or as an inertial mass to be coupled.

Furthermore, it is proposed that: the hand-held reciprocating saw is a semi-automatic hand-held reciprocating saw. The semi-automatic reciprocating saw is at least provided with: the desired cutting line, in particular the cutting line marked on the workpiece, is followed by itself and is pushed in the main feed direction only by the user. The object of the invention is advantageously to improve the cutting quality, in particular the quality of curved cuts, precisely on a semiautomatic reciprocating saw.

Multiple actuators, acting in the same and/or different, may also be used to avoid or reduce wandering of the reciprocating saw.

Drawings

Embodiments of the invention are illustrated in the drawings and described in detail in the following description. The drawings, the description and the claims contain a number of features in combination. The expert can consider and generalize these features individually to other combinations of significance according to the destination.

The figures show:

figure 1 is a schematic view of a reciprocating saw of the present invention in the form of a jigsaw,

fig. 2 is a schematic view of a reciprocating saw according to the invention in the form of a jigsaw during a sawing operation, wherein the reciprocating saw lies flat on a workpiece and the saw blade is drawn in a normal state and in an undesirably deflected state,

fig. 3 is another schematic view of a reciprocating saw according to the invention in the form of a jigsaw, in which the different operating principles of at least one actuator for correcting deflection are shown,

fig. 4 is a schematic detail of the reciprocating saw according to fig. 3 in a further exemplary embodiment, wherein the detail shows the saw blade received by the tool receiver and the workpiece and shows a further operating principle of the at least one actuator.

Detailed Description

Fig. 1 shows in schematic side view a reciprocating saw 10 of the present invention in the form of a jigsaw 12. The jigsaw 12 has a saw blade 14, which is provided for producing a cut in a workpiece or workpiece 16 (compare fig. 2) in a feed direction 18. To this end, the saw blade 14 executes an alternating reciprocating linear movement 20 at least substantially along a reciprocating or vertical axis 22 in a known manner. Furthermore, the reciprocating linear motion 20 can also at least partially superimpose the oscillating motion introduced by the oscillating device 21 in the feed direction 18 in a known manner. In order to produce a substantially vertical cut in the workpiece 16 in a cutting plane (not shown) which is extended by the feed direction 18 and the vertical axis 22, the saw blade 14 is arranged either perpendicular to the underside of the base plate 24 or perpendicular to the workpiece support surface, or the vertical axis 22. To produce the desired oblique cut or the desired side cut, the jigsaw body or machine housing 26 of the jigsaw 12 can be pivoted manually relative to the base plate 24 in a known manner transversely to the feed device 18 or about the feed direction axis. The jigsaw 12 also has a drive train 28 which includes at least one reciprocating linear motion device 30 which is preferably driven by a motor 32 and a force transmitting element such as a transmission 33. Piezoelectric direct drive of the reciprocating linear motion device and the like are also possible. The saw blade 14 is coupled to the linear reciprocating device 30 via a tool receiver 34 and is driven in an oscillating or alternating manner by the linear reciprocating device. Furthermore, one or more sensors 35 and/or actuators 37 according to the invention are arranged on the jigsaw 12.

Fig. 2 shows a schematic front view of the jigsaw 12. The jigsaw 12 is placed with its base plate 24 on the workpiece 16. The blade 14 of the jigsaw 12 is shown in a normal condition 36 and a deflected condition 38. The condition of the saw blade 14 is monitored by a sensor 35 (compare fig. 1). In the deflected state 38, the saw blade 14 is bent transversely with respect to a cutting plane of the saw blade 12, which is not shown. And may also be twisted. The resulting cut deviation 38 is either undesirably curved. In the proper or normal state 36, the inlet 40 of the saw blade 14 when it enters the workpiece 16 on the workpiece upper side 42 facing the jigsaw 12 and the outlet 44 of the saw blade 14 when it exits the workpiece 16 on the workpiece lower side 46 facing away from the jigsaw 12 are on a straight line connecting the inlet 40 and the outlet 44, preferably on a vertical line connecting the inlet 40 and the outlet 44 and passing through the workpiece 16 on an extension of the vertical axis 22. While in the deflected condition 38, the exit 48 of the saw blade 14 is displaced an amount 50 in a transverse direction relative to the cutting plane. The greatest deflection of the deviating saw blade 14 preferably occurs at the exit opening 48 or at the exit point of the saw blade 14 from the workpiece 16 on the workpiece underside 46 facing away from the jigsaw 12. Similarly, a deflection can also occur at the breaking cut in such a way that the saw blade 14 is also bent in a transverse direction in relation to the then inclined cutting plane, here in particular at the exit opening 48 of the saw blade when it emerges from the workpiece 16. The run-off effect increases in a known manner as the thickness of the workpiece increases, as the swing strength of the saw blade 14 increases during a curved cut and/or as the feed speed increases. Furthermore, deflection can also mean a curling or twisting 54 of the saw blade 12 about the vertical axis 22, which increases the displacement effect and further reduces the cutting quality. The deflection 38 can be corrected or compensated for by means of the actuator 37 (compare fig. 1). To simplify the description of the next step, a coordinate system 56 is also shown in fig. 2. The X-axis points in the direction of the feed direction 18 and the Z-axis points in the direction of the vertical axis 22, wherein the X-axis and the Z-axis extend the cutting plane and the Y-axis runs transversely to the cutting plane.

Fig. 3 likewise shows the jigsaw 12 in a schematic front view. The jigsaw 12 rests with the workpiece support surface or bed 24 on an upper side 42 of the workpiece 16. The saw blade 14 or machine housing 26 is oriented perpendicularly relative to the workpiece support surface of the base plate 24. The jigsaw 12 is thus configured to produce a vertical cut in the workpiece 16 with respect to the upper or lower workpiece sides 42, 46. In order to detect and correct a deviation 38 (compare fig. 2), a sensor 35 and an actuator 37 (compare fig. 1 here) are provided. Furthermore, the sensor 35 can also be arranged separately from the jigsaw 12, for example on a table, and be connected to the saw blade 12 by wire or wirelessly, for example via the WLAN 58. In the present case, the sensor 35 is embodied as a camera for taking a picture of the saw blade emerging from the workpiece underside 46 and for example measuring an angle 60 between the orientation of the saw blade 14 and the workpiece underside 46. The following shows different operating principles for correcting a deviation 38 (compare fig. 2). For example, the vertical axis 22 or the linear reciprocating device 30 and/or the tool receiver 34 and/or the entire jigsaw 12 can be displaced in the direction of the double arrow 62 parallel to the base plate 24 or in the direction of the Y axis. This movement is preferably performed against the direction of off tracking of the saw blade 14. Thus, if the saw blade 14 is off tracking in the positive Y-axis direction, the vertical axis 22 or the reciprocating linear motion device 30 and/or the tool receiver 34 and/or the jigsaw 12 is displaced in the negative Y-axis direction. Alternatively and/or in combination, it is also possible to pivot or tilt the vertical axis 22 or the linear reciprocating device 30 and/or the machine housing 26 relative to the base plate 24 and/or the entire jigsaw 12 together with the base plate 24 about the X axis in the direction of the double arrow 64. The resulting effect is illustrated by the schematically inclined or displaced vertical axis 66. The pivoting or tilting preferably takes place counter to the running direction. In addition, or in combination with the pivoting, it is at least possible to rotate 68 the reciprocating linear motion device 30 and/or the tool receiver 34 and/or the pivoting device 21 (compare fig. 1) and/or the machine housing 26 relative to the base plate 24 and/or the entire jigsaw 12 about the Z-axis or vertical axis 22, at least in order to compensate or reduce the deflection 38. Preferably, the rotation 68 likewise takes place counter to the direction of deflection. If, for example, the saw blade 12 is deflected in the negative Y-axis direction, the saw blade 12 is rotated in the clockwise direction about the Z-axis until the saw blade 36 again cuts in the normal state 36. The individual or combined displacement movements and/or pivoting movements and/or twisting movements are advantageously matched in terms of their strength to the degree of deviation, preferably in an adjustable manner, for example in the three modes of light, normal or strong correction and/or slow, normal or fast correction. In principle the corrective movement is relatively small. The displacement is preferably in the millimeter range or in the tenth millimeter range, and the oscillation and/or torsion is preferably in the one digit angular range or in the tenth angular range. The control or regulation of the actuator can be effected by a not shown central control or regulating device of the hand-held reciprocating saw, which can advantageously also analyze the measurement signals of the sensor and preferably compare them again with a nominal value list stored in a not shown memory of the hand-held reciprocating saw.

Fig. 4 shows a schematic detail of a further exemplary embodiment of a hand-held jigsaw 10 in the form of a jigsaw 12, wherein the detail shows a further operating principle of the saw blade 14, the workpiece 16 and the at least one actuator 37, which are received by the tool receiver 34. The coordinate system 56 according to fig. 2 and 3 is also shown. The actuator 37 is formed by four individual actuators 37a, b, c, d. The actuators 37a, b, c, d likewise comprise four individual sensors 35a, b, c, d. The actuators 37a, b, c, d are arranged diagonally on both sides of the saw blade 14 or cutting plane, respectively. The actuators 37a, c arranged in pairs in this way and the further actuators 37b, d arranged in pairs are also vertically offset relative to one another in the Z-axis direction. The actuator 37 or the actuators 37a, b, c, d act on a transverse guide 70 or four corresponding guide elements 70a, b, c, d for guiding the saw blade 14. The transverse guides 70 are embodied, for example, as hard metal blocks, pins, rollers and the like. They are capable of receiving and supporting lateral forces and/or moments generated by the saw blade 14 or by the running rails 38. The transverse guides 70a, b, c, d are connected at least indirectly to the machine housing 26 or the base plate 24 and are supported thereon. The sensors 35a, b, c, d can also sense forces, in particular lateral forces and/or moments, acting on the actuator 37. By means of the actuators 37a, b, c, d, it is advantageously possible to introduce reaction forces and/or torques into the saw blade 14, which counteract the deflection 38 already described.

Claims

1. Hand-held reciprocating saw (10) having a saw blade (14) and having a sensor (35) for sensing a deflection (38) of the saw blade (14), and having a control or regulating device for evaluating a sensor signal and for actuating at least one actuator (37) which counteracts a deflection (38) of the saw blade (14), characterized in that: at least one further actuator (37) actuated by the control or regulating device is designed to change the oscillation, the sawing speed and/or the number of reciprocating linear movements of the oscillating device (21) in order to counteract a deflection (38) of the saw blade (14).

2. The hand held reciprocating saw (10) as set forth in claim 1, wherein: the sensor (35) detects a deflection (38) of the saw blade (14) in a drive train (28) of the reciprocating saw (10) or by means of a motor (32) of the drive train (28) and/or directly in or on the saw blade (14).

3. A hand held reciprocating saw (10) as defined in claim 1 or 2 wherein: the actuator (37) is provided for causing tilting of the reciprocating linear motion device (30) relative to the base plate (24) of the reciprocating saw (10), tilting of the entire reciprocating saw (10) and/or tilting of the reciprocating saw body (26) of the reciprocating saw (10).

4. A hand held reciprocating saw (10) as defined in claim 1 or 2 wherein: the actuator (37) is provided for displacing the reciprocating saw (10) relative to a work piece (16) to be sawed, the reciprocating saw body (26) relative to the base plate (24) and/or the reciprocating linear motion device (30) within the reciprocating saw (10) or the reciprocating saw body (26) transversely to the vertical axis (22) of the reciprocating saw (10).

5. A hand held reciprocating saw (10) as defined in claim 1 or 2 wherein: the actuator (37) is provided for rotating the reciprocating saw (10) relative to the work piece (16) to be sawn, the reciprocating saw body (26) relative to the base plate (24) and/or the reciprocating linear motion device (30) within the reciprocating saw (10).

6. A hand held reciprocating saw (10) as defined in claim 1 or 2 wherein: the actuator (37) introduces forces and/or torques onto the saw blade (14) via at least one transverse guide (70) of the saw blade (14) formed on the reciprocating saw (10).

7. A hand held reciprocating saw (10) as defined in claim 1 or 2 wherein: the actuator (37) counteracts a bending of the saw blade (14) caused by the deflection (38) by influencing the bending line of the saw blade (14).

8. A hand held reciprocating saw (10) as defined in claim 1 or 2 wherein: the hand-held jigsaw (10) is a semi-automatic hand-held jigsaw.

9. The hand held reciprocating saw (10) as set forth in claim 1, wherein: the deflection (38) of the saw blade (14) is the deflection of the saw blade (14) in the sawing material (16).

10. The hand held reciprocating saw (10) as set forth in claim 2, wherein: the sensor (35) detects deflection (38) of the saw blade (14) within the transmission (33).

11. The hand held reciprocating saw (10) as set forth in claim 5, wherein: the actuator (37) is provided for rotating the reciprocating saw (10) relative to the work piece (16) to be sawed, the reciprocating saw body (26) relative to the base plate (24) and/or the reciprocating linear motion device (30) within the reciprocating saw (10) about a vertical axis (22) of the reciprocating saw (10).