WO2012041833A1

WO2012041833A1 - Hand tool comprising a rotary drive and a brake

Info

Publication number: WO2012041833A1
Application number: PCT/EP2011/066734
Authority: WO
Inventors: Jan Sitzler; Dieter Kaiser
Original assignee: Schmid & Wezel Gmbh & Co.
Priority date: 2010-09-27
Filing date: 2011-09-27
Publication date: 2012-04-05
Also published as: EP2621684B1; SI2621684T1; PL2621684T3; EP2621684A1; EP2621684B8; ES2573130T3; DE202010013939U1

Abstract

The invention relates to a hand tool (10), comprising a housing (12), a rotor (32), which is rotatably mounted in the housing (10) and non-rotatably coupled to a tool holder (14), a valve (45), which is equipped to control a supply of a pressure fluid driving the rotor (32), a brake, which is equipped to decelerate the rotor (32), and an actuating element, which is equipped to actuate the valve (45) and the brake in a coordinated manner such that the brake decelerates the rotor (32) in a closed position of the valve (45) which interrupts the supply of the pressure fluid. The hand tool (10) is characterized in that the actuating element is a rotatable control sleeve (18), which is equipped to control the brake and the pressure fluid supply in a coordinated manner such that the valve (45) is opened at the same time as the brake is released, and wherein a characteristic brake-adjustment travel-rotary angle curve (114) of the control sleeve (18) in a first rotary angle range in the vicinity of the closed position of the control sleeve (18) is steeper than in a second rotary angle range further removed from the closed position.

Description

Handwerkzeug mit einem Drehantrieb und einer BremseHand tool with a rotary drive and a brake

The present invention relates to a hand tool according to the preamble of claim 1. Such a hand tool is known from DE 201 03 600 U1.

The known hand tool is a compressed air tool with a rotatably mounted in a housing turbine. The turbine has a rotor which is adapted to be driven by compressed air and which is non-rotatably coupled to a tool holder. The hand tool further includes a valve configured to control a supply of compressed air to the rotor, a brake configured to brake the rotor, and an actuator configured to coordinate the valve and the brake so to actuate that the brake brakes the rotor in a closing position of the valve which interrupts the supply of compressed air.

The actuator of the known hand tool is a slide switch in the form of a sliding sleeve which is slidably mounted on a tubular portion of a compressed air leading part of the hand tool. The tubular portion has an end pneumatically connected to the rotor and an end adapted for connection to an external compressed air supply. The two ends are pneumatically separated within the tubular portion, but have radially outwardly facing compressed air channels which pierce an outer surface of the tubular portion and which are sealed by the sliding sleeve against the environment. The resulting openings on the outer surface of the tubular portion have an axial distance in the direction of a tube axis of the tubular portion, so that there is no connection between its two ends within the tubular portion.

The sliding sleeve has in its inner surface an annular groove whose axial extent is at least as large as the axial distance of said openings. In order to allow compressed air supply to the rotor, the sleeve is axially displaced so that the annular groove connects the openings of the radially outwardly facing channels of the two ends of the tubular portion with each other. In order to stop a compressed air supply to the rotor, the sleeve is displaced so that the annular groove is at least not more than two openings, so that the openings are no longer connected via the annular groove. The control and Absteuern the compressed air supply is thus carried out via a displacement of the sleeve, which corresponds to a clearance of the opening of a radial compressed air channel. In relation to the total displacement of the sliding sleeve, this clear width is relatively small, so that the Aufsteuern and Absteuern more similar to a digital switching on and off the compressed air supply as a gradual take-off and Absteuern.

The brake of the known hand tool has an annular friction lining, which is connected via coaxial with the axis of rotation of the rotor arranged control pins translationally rigid with the sliding sleeve. The rotor itself has an annular end configured as a contact surface for the friction lining. To slow down the rotor, the sliding sleeve is pressed manually in the direction of the ring end. The braking force is applied by the manual operation. Without manual operation of the sliding sleeve no braking force is generated.

During the transition from a standstill of the rotor with switched off compressed air supply to a state with the compressed air supply switched on, the slide switch is pushed away from the rotor. Then the friction lining is first lifted off the annular face while the compressed air supply is still closed. This is followed by a free travel, in which the sliding sleeve is moved translationally, without causing a take place via the annular groove pneumatic connection of the two ends of the tubular portion. Subsequently, the compressed air supply is opened by a displacement of the sliding sleeve, which corresponds to a clearance of the opening of the radial compressed air ducts in the direction of displacement.

The object of the invention is to specify a hand tool of the type mentioned, which is characterized by better handling during operation.

This object is achieved with the features of claim 1. The present invention is distinguished over the above-mentioned prior art in that the actuating element is a rotatable control sleeve which is adapted to coordinate the brake and the pressure fluid supply controlled so that the valve is opened in parallel to a release of the brake and wherein a brake displacement-rotational angle characteristic of the control sleeve in a first rotation angle range in the vicinity of the closed position of the control sleeve is steeper than in a second, further from the closed position remote rotation angle range.

The realization of the actuating element as a rotary sleeve has the advantage that a rotational movement for the adjustment of the hand tool mentioned above is subjectively perceived as ergonomic. The interaction of adjusting torque and the torque of the hand tool causes in the rotatable control sleeve with respect to the translationally moving sliding sleeve better and more sensitive haptic feedback, as superimposed on the manually applied adjusting torque with a resulting change in torque of the hand tool. The better haptic feedback in particular improves the controllability of small changes in the drive power, which improves handling by improving the metering.

The control of the compressed air supply, which takes place in parallel with releasing the brake, permits an expansion of the adjustment path of the actuating element during the metering of the compressed air supply, which likewise leads to an improvement in the meterability and thus also in the handling.

Characterized in that a brake-displacement-rotational angle characteristic of the control sleeve in a first rotation angle range in the vicinity of the closed position of the control sleeve is steeper than in a second, further away from the closed position rotation angle range, is a fast separation of the brake when opening and a late Successful closing the brake when Absteuern the compressed air supply ensured. Due to the steeper course, the opening of the brake when opening the compressed air supply takes place early and quickly, that is, over only a small rotational angle range of the sleeve. Similarly, the closing of the brake is late and fast. Overall, despite the parallel operation of the valve and the brake taking place under the influence of a compressed air drive rubbing the friction surfaces of the brake largely avoided, so that improved metering of compressed air supply is not at the expense of the life of the brake.

A preferred embodiment is characterized in that the control sleeve is adapted to allow a control and Absteuerung the compressed air supply over a larger rotation angle range done as a release and actuation of the brake. The control takes place in particular via a rotation angle range of the control sleeve, which extends beyond a rotational angle, in which the brake is already completely dissolved.

This avoids, on the one hand, that large torques become effective when the brake is not yet fully released, which could lead to premature wear of the brake. On the other hand, there is the advantage that a large angle of rotation for an up and down control of the compressed air supply is available, which improves the one aspect of the handling formability dosing.

Further advantages will be apparent from the dependent claims, the description and the attached figures.

It is understood that the features mentioned above and those yet to be explained below can be used not only in the particular combination given, but also in other combinations or in isolation, without departing from the scope of the present invention.

drawings

Embodiments of the invention are illustrated in the drawings and are explained in more detail in the following description. Show, in schematic form:

Figure 1 is a perspective view of a hand tool according to the invention;

Figure 2 is a plan view of a pressure-connection part of the hand tool of Figure 1;

FIG. 3 shows a longitudinal section through the hand tool according to the invention from FIG. 1;

Figure 4 is a perspective view of a control sleeve;

Figure 5 is a plan view of a front side of the control sleeve;

Figure 6 shows a longitudinal section through the control sleeve;

FIG. 7 shows a cross section of the control sleeve through a guide track of a valve pin;

Figure 8 is a schematic representation of a preferred embodiment of various components of a brake of the hand tool;

Figure 9 is another view of the article of Figure 8; and

FIG. 10 shows adjustment-rotational angle characteristics of the brake and the valve actuation of an embodiment of a hand tool according to the invention.

1 shows an embodiment of a hand tool 10 according to the invention. The hand tool 10 has a housing 12 designed as a handle part, from the front end of which a tool holder 14 protrudes. The tool holder 14 is rotatably connected to a rotor which is rotatably mounted in the housing 12 and is driven by a pressurized fluid. Compressed air is in particular compressed air in question. The compressed air is supplied to the hand tool 10 via a connecting part 16, which has a valve for controlling the compressed air supply. The actuation of the valve via a rotatable control sleeve 18, which is arranged at a rear end 20 of the housing 12 between the housing 12 and the connecting part 16. The control sleeve 18 has a front end 22 and a rear end 24.

The housing 12 is a preferred embodiment 80 to 120 mm long and has at its front end 15 a comparatively small diameter of 15 to 25 mm and at its rear end 20 a comparatively large diameter of 25 to 35 mm.

By these dimensions, the hand tool 10 is well suited to be held in one hand, the front end can be held in particular like a pen. This particularly good handling allows a very fine working with the hand tool 10, in particular in conjunction with the improved metering of the compressed air supply.

FIG. 2 shows a plan view of the connection part 16 from FIG. 1. The connection part 16 has a central supply air opening 26 and a plurality of peripherally arranged exhaust air openings 27.

Figure 3 shows a longitudinal section through the hand tool 10 along the line III-III of Figure 2. In the illustrated embodiment, the housing has an inner sleeve 28 and an outer sleeve 30, which are fitted into each other and tightly joined together. The inner sleeve 28 is preferably made of metal, in particular a light metal such as aluminum and gives the housing 12 the required strength.

The execution of the inner sleeve of light metal keeps the weight of the hand tool 10 low, which also contributes to a good handling and fatigue-free work, especially in fine work.

The outer sleeve 30 is preferably made of a compared to the metal of the inner sleeve 28 poor heat conductive plastic.

This has the advantage that the cooling occurring during the relaxation of the compressed air in the hand tool 10 during manual handling does not lead to an annoying cooling of the gripping surface of the outer sleeve 30

In the inner sleeve 28, a rotor 32 is rotatably mounted in bearings 34, 36. The rotor 32 is at its end, which protrudes from the front end 15 of the housing 12, rotatably connected to a tool holder 14. The tool holder is in one embodiment, a collet 38, which is connected via a pliers spindle 40 with the rotor 32. The other end of the rotor 32 is configured as a hollow spindle 42 whose central cavity 44 is pneumatically connected to the compressed air supply when the compressed air valve 45 is open and the compressed air supply connected to the connection part 16.

On an outer surface of the spindle 42 are preferably n mutually equal radial turbine modules 46, 48, 50, 52 are arranged, where n may be equal to two or in principle any number greater than 1. In a preferred embodiment, n is less than or equal to eight. Particularly preferred is an embodiment with n = 4 radial turbines. By the successive arrangement of n radial turbines, which have a comparatively small diameter, the same torque can be generated, as by a single radial turbine, which has a comparatively large diameter. A hand tool with a single radial turbine with a comparatively large diameter is known from the aforementioned DE 201 03 600 U1.

The preferred sequential arrangement makes it possible to make the housing 12 substantially slimmer than is the case with the subject matter of DE 201 03 600 U1. The slimmer design of the housing 12 improves the handling of the hand tool 10. The series connection thus improves the handling in particular in an indirect manner and in particular develops together with the features of claim 1, which relate to a coordinated control of the compressed air supply and the brake and also improve the handling , a combinatorial effect.

The radial turbines 46, 48, 50, 52 are flowed over in the axial direction along the spindle 42 offset openings 54, 56, 58, 60 from the cavity 44 of the spindle 42 from the inside with compressed air. In this case, three openings are preferably provided for each module of the radial turbine, which are distributed uniformly over the circumference of the portion of the spindle 42 which is within the respective radial turbine module. After flowing through the radial turbines, the expanded air escapes radially outward, from where it flows out of the hand tool 10 via a silencer 62 having exhaust air duct 64. The radial turbines 46, 48, 50, 52 are rotatably coupled to the spindle 42 of the rotor 32 and therefore drive the rotor 32 at. In the illustrated embodiment, the non-rotatable coupling by axial clamping of the radial turbines 46, 48, 50, 52 with the spindle 42 by a clamping nut 66 follows.

In operation, the turbine speeds can reach min ^-1 in an order of 100 000th When switching off the compressed air supply, it then continues to run for, for example, about 30 seconds. This results in a safety and injury risk during handling. In order to reduce these risks, the hand tool 10 has a brake which is partially visible in FIG. 3 as a pairing of a friction plate 68 and a pressure plate 70 and which will be explained in more detail below.

The compressed air valve 45 in the illustrated embodiment is a ball valve having a ball 72 which is urged by a resilient member 74, for example a spring, onto a circular supply port of a compressed air channel 76 to close that opening. The compressed air channel 76 is preferably a central channel in a valve body 77. To open the valve 45, a valve pin 78 is provided. The valve pin 78 has a first end 80 facing the ball 72 and a second end 82 which is guided in a recess in the inner surface of the control sleeve 18 that is shaped as a valve guide track 84.

The valve pin 78 itself is guided substantially radially in a guide within the valve body 77. With respect to a longitudinal axis 86 of the hand tool 10, the distance of that control surface of the valve guide track 84, which faces the second end 82 of the valve pin 78, of the longitudinal axis 86 of the hand tool from the rotation angle of the control sleeve 18 is dependent. This means that the inward and outward movement of the valve pin 78 is controllable by a rotation of the control sleeve 18.

Figure 3 shows a closed position of the valve 45. To open the valve 45, the control sleeve 18 is rotated about the axis 86 around. Due to the design of the guide track 84, the valve pin 78 is initially pressed radially inwardly against the ball 72. Upon further rotation of the control sleeve 18 of the valve pin 78 then pushes the ball 72 laterally (ie in the figure 3 upward) out of the closed position, so that compressed air can flow over the central air inlet opening 26 on the ball 72 in the compressed air passage 78.

Figure 4 shows a perspective view of a control sleeve 18. The control sleeve 18 has distributed over its outer circumference recesses 88, which facilitate the adhesion in a manual operation and thus also contribute to improved handling.

The axially extending recess 90 opens the valve guide track 84 to the front end 22 of the control sleeve 18 and thus allows an axial relative movement between the valve pin 78 and the control sleeve eighteenth., In the control sleeve 18, the above-mentioned, realized as a recess valve guide track 84 for the valve pin 78th During assembly and / or disassembly of the hand tool 10. In addition, the control sleeve 18 has two open towards its front end 22 brake pin guide tracks 92, 94, which are also realized as depressions in the inner surface of the control sleeve 18.

Figure 5 shows a plan view of the front end 22 of the control sleeve 18 and serves primarily to illustrate the position of the longitudinal section, which is shown in the figure 6. FIG. 6 illustrates, in particular, the position of the cross section, which is shown in FIG. Figures 5 and 7 are mirror images of each other. In the drawing plane of FIG. 7, the valve guide track 84 lies in particular. A comparison of these FIGS. 5 and 7 shows in particular that the actuation of the brake and the actuation of the compressed-air valve 45 take place in parallel. wherein the control and Absteuerung the compressed air supply over a further rotation angle range away takes place as a releasing and / or braking operation of the brake.

FIG. 8 shows, in a schematic form, an embodiment of a brake, as it is actuated by the control sleeve 18 in connection with the hand tool 10 according to the invention. The brake has for each brake pin guide track 92, 94 of the control sleeve 18 on a brake pin 96 which is guided in the valve body 77 substantially perpendicular to the longitudinal axis 86 of the hand tool 10 movable. For this purpose, the valve body 77 guides 98, in which the brake pins are guided translationally displaceable.

The brake pin 96 has an end facing the control sleeve 18 and a control sleeve 18 facing away from the end 102. At this end 102, the brake pin 96 has an inclined plane 104. A substantially coaxial and in particular coaxial with the longitudinal axis 86 of the hand tool 10 lying brake axis 105 has a recess with an inclined plane 106. The inclined planes 104 of the brake pin 96 and the brake axle 105 have the same inclination and are arranged and arranged to slide on each other.

During the opening rotation of the control sleeve 18, the brake pin 96 is pressed down in FIG. 11 and thereby presses the brake axis 105 to the right via the inclined planes 104 and 106. As a result, a pressure plate 108 is lifted by the action of brake springs 110 from a friction plate 112, which is rotatably coupled to the rotor 32. This releases the brake.

In other words: the hand tool 10 is adapted to press the brake pin 96 inwardly during the opening rotation of the control sleeve 18 and thereby the brake axis 105 will be wegzubwegen over the inclined planes 104 and 106 of a non-rotatably coupled to the rotor 32 friction plate 112 of the brake, such that a pressure plate 108 coupled to the brake axle is lifted off the friction plate 112 by the action of brake springs 110. The brake springs also push the brake axles away with the pressure plate.

Conversely, the brake is activated when the control sleeve 18 is rotated in a direction abscursing the compressed air supply and thus closing direction. In this case, the brake pin 96 slides in the figure 11 upwards, or outwards, and allows the brake springs 110 to press the pressure plate 108 against the friction lining 112.

The brake is thus realized as a spring brake in which the braking force is applied by springs and is released against the force of the springs. This has the advantage that the closing rotation of the control sleeve 18 is automatically braked, even if no manual force is applied when the control sleeve 18 is closed.

A manual hold the brake is therefore not required. This also improves the handling and the reliability. On the other hand, the brake springs but also do not cause automatic adjustment of the control sleeve 18, since the reaction forces of the springs 110 are not sufficient to overcome the self-locking frictional forces in the operation of the control sleeve 18.

FIG. 9 shows the object of FIG. 8 in a representation rotated through 90 ° about the longitudinal axis 86.

By the two offset by 180 ° brake axes 105 tilting when operating the brake is effectively prevented. In addition, the displacement of the brake axes 105 by 180 ° has the advantage that the brake axes 105 can be distributed around the circumference, so that the central compressed air supply to the rotor can be maintained. The bolts 92 and 94 are preferably mounted so that they move against each other in an anti-parallel operation: The bolt 96 is perpendicular to the plane of the drawing, while the bolt 100 is suspended vertically below the plane of the drawing.

Fig. 10 shows for a preferred embodiment of a control sleeve 18, the path 114 of a brake axis 105 in millimeters, plotted against the rotation angle of the control sleeve 18 in degrees. The curve 116 shows the path of the valve pin 78 of the compressed air valve 45 also in dependence on the angle of rotation of the control sleeve 18 in degrees. FIG. 10 thus shows, in particular, that the rotatable control sleeve 18 is configured to control the brake and the pressurized fluid supply in such a way that the compressed-air valve 45 is opened in parallel to release of the brake, and wherein a brake displacement-rotational angle characteristic 114 the control sleeve 18 in a first rotation angle range, which extends in the figure 10 approximately to the angle 32 °, is steeper than in a second, further away from the closed position rotation angle range.

The closed position corresponds to the object of the figure 10, the rotation angle 0 of the control sleeve 18. The second rotation angle range is the range between about 32 and about 110 °, in which the characteristic 114 is not only less steep, but in the illustrated case even without inclination. The course of the characteristic curve 116 shows how the entire angle of rotation range of 0 ° to 110 ° of the control sleeve 18 is used to regulate the supply of compressed air. This results in the already mentioned improved meterability.

Both

characteristic curves

114, 116 have different angular ranges for the angle of rotation of the control sleeve, in which the respective characteristic has a non-zero slope. Each of the two angular ranges can be mentally divided into a first half and a second half, wherein the first half contains the closed position and the second half of the open position of the air valve, or the brake.

The characteristic curve 114 is preferably distinguished by the fact that in the first half or at least in a partial area of its first half it becomes progressively steeper, preferably a continuously steeper course and overall monotonically increasing course. In addition, the characteristic 114 is characterized in that it has a course with decreasing slope, preferably with continuously decreasing slope, at least in a partial area of its second half. The characteristic curve 114 is therefore distinguished in a preferred embodiment by a continuously increasing profile with a change of curvature. The characteristic curve 116 is preferably characterized in that in its first half or at least in a partial area of its first half it has a steeper course, preferably a continuously steeper course and an overall monotonically increasing course. The slope of the characteristic 116 is on average between its closed position and its open position smaller than the slope of the characteristic 114 between the closed position and the open position.

Claims

A hand tool (10) having a housing (12) and a rotor (32) rotatably mounted in the housing (10) and non-rotatably coupled to a tool receptacle (14) having a valve (45) adapted to receive a supply controlling a pressurized fluid driving the rotor (32), a brake adapted to brake the rotor (32), and having an actuator configured to actuate the valve (45) and brake in a coordinated manner; in that the brake brakes the rotor (32) in a closed position of the valve (45) interrupting the supply of the pressurized fluid, characterized in that the actuating element is a rotatable control sleeve (18) arranged to coordinate the brake and the pressurized fluid supply so controlling that the valve (45) is turned on in parallel with a release of the brake, and wherein a brake displacement-rotational angle characteristic (114) of the control sleeve (18) in a first rotation angle range in the vicinity of the closing Positioning of the control sleeve (18) is steeper than in a second, further away from the closed position rotation angle range.
Hand tool (10) according to claim 1, characterized in that the control sleeve (18) is adapted to allow a control and Absteuerung the pressure fluid supply over a larger rotation angle range done as a release and actuation of the brake.
Hand tool (10) according to one of the preceding claims, characterized in that the housing (12) has an inner sleeve (28) which consists of metal.
Hand tool (10) according to claim 6, characterized in that the housing (12) has an outer sleeve (30) which consists of a compared to the metal of the inner sleeve (28) poor heat conductive plastic.
Hand tool (10) according to one of the preceding claims, characterized in that the housing (12) is 80 to 120 mm long and has at its front end (15) a comparatively small diameter of 15 to 25 mm and at its rear end (20). has a comparatively large diameter of 25 to 35 mm.
Hand tool (10) according to any one of the preceding claims, characterized in that the hand tool (10) n successively arranged radial turbines (46, 48, 50, 52), wherein n is a number greater than or equal to two and less than or equal to eight, in particular equal four is.
Hand tool (10) according to one of the preceding claims, characterized in that the hand tool has a spring-loaded brake.
Hand tool (10) according to claim 7, characterized in that brake is actuated by the control sleeve (18), wherein the brake for each brake pin guide track (92, 94) of the control sleeve (18) has a brake pin (96) in a valve body ( 77) is guided movably substantially at right angles to the longitudinal axis (86) of the hand tool (10).
Hand tool according to claim 8, characterized in that the valve body (77) guides (98), in which the brake pins (96) are guided translationally displaceable.
Hand tool (10) according to claim 9, characterized in that the brake pin (96) has a control sleeve (18) facing the end and the control sleeve (18) facing away from the end (102) with an inclined plane (104).
Hand tool according to claim 10, characterized in that a substantially coaxial, in particular coaxial with the longitudinal axis (86) of the hand tool (10) lying brake axis (105) has a recess with an inclined plane (106), wherein the inclined planes (104) of Brake pin (96) and the brake axle (105) have the same inclination and are arranged and arranged to slide on each other.
Hand tool (10) according to claim 11, characterized in that it is adapted to press the brake pin (96) inwardly during the opening rotation of the control sleeve (18) and thereby deflect the brake axis (105) over the inclined planes (104) and (14). 106) is moved away from a friction plate (112) of the brake which is non-rotatably coupled to the rotor (32), so that a pressure plate (108) coupled to the brake axis is lifted off the friction plate (112) by the action of brake springs (110).
A hand tool (10) according to claim 12, characterized in that it is arranged to allow the brake pin 96 to slide outwardly upon a closing rotation of the control sleeve (18), thereby allowing the brake springs (110) to contact the pressure plate (108) to press the friction lining (112).
Hand tool (10) according to one of claims 7 to 13, characterized in that it comprises two by 180 ° about the circumference of a pressure plate (108) of the brake offset brake axes (105).
Hand tool (10) according to one of claims 7 to 14, characterized in that the brake comprises two brake pins (92) and (94) which are mounted in the valve body (77) so that they are actuated by the control sleeve (18). move antiparallel to each other.