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DE-102018218381-B4 - Hand-held power tool, in particular jigsaw with blower attachment

DE102018218381B4DE 102018218381 B4DE102018218381 B4DE 102018218381B4DE-102018218381-B4

Abstract

hand-held power tool (10), in particular jigsaw, for producing a cut (115) in a feed direction (V) in a workpiece (15), - comprising a tool holder (40), a cutting area (110), a housing (20), a support device (35) for supporting the hand-held power tool (10) on the workpiece to be machined (15), in particular a base plate (50), and a blowing device (30), - wherein the housing (20) has a housing bottom (135) and a housing front (125), - wherein the tool holder (40) is designed to accommodate an insert tool (80), in particular a saw blade (85), along a mounting axis (75), - wherein the support device (35) can be placed against the workpiece (15) in a guide plane (55), - wherein the receiving axis (75) intersects the guide plane (55) in a cutting area (110), - wherein the blowing device (30) has a first air channel (160) which terminates in a first channel opening (205) which is arranged on the underside of the housing (135) in the feed direction (V) in front of the tool holder (40) and is designed to inject an airflow (330) into the cutting area (110), characterized in that - the blowing device (30) further comprises a conveying unit (175) for generating the airflow and a second air channel (165), - wherein the blowing device (30) has a valve (170) which is switchable between a first valve position and a second valve position, - wherein the valve (170) is fluidically connected on the inlet side to the conveying unit (175) and on the outlet side to the first air duct (160) and the second air duct (165), - and wherein in the first valve position a fluidic connection is established between the conveying unit (175) and the first air duct (160) and in In the second valve position, a fluidic connection is established between the pumping unit (175) and the second air duct (165).

Inventors

  • Thorsten Kuehn
  • Florian Esenwein

Assignees

  • ROBERT BOSCH GMBH

Dates

Publication Date
20260513
Application Date
20181026

Claims (9)

  1. Hand-held power tool (10), in particular a jigsaw, for producing a cut (115) in a workpiece (15) in a feed direction (V), - comprising a tool holder (40), a cutting area (110), a housing (20), a support device (35) for supporting the hand-held power tool (10) on the workpiece (15), in particular a base plate (50), and a blowing device (30), - wherein the housing (20) has a lower housing side (135) and a housing end side (125), - wherein the tool holder (40) is designed, a tool (80), in particular a saw blade (85), is to be mounted along a receiving axis (75), wherein the support device (35) can be placed against the workpiece (15) in a guide plane (55), wherein the receiving axis (75) intersects the guide plane (55) in a cutting area (110), wherein the blowing device (30) has a first air channel (160) which terminates in a first channel opening (205) which is arranged on the underside (135) of the housing in the feed direction (V) in front of the tool holder (40) and is designed to inject an airflow (330) into the cutting area (110), characterized in that the blowing device (30) further comprises a conveying unit (175) for generating the airflow and a second air channel (165), wherein the blowing device (30) has a valve (170) which is switchable between a first valve position and a second valve position is, - wherein the valve (170) is fluidically connected on the inlet side to the conveying unit (175) and on the outlet side to the first air duct (160) and the second air duct (165), - and wherein in the first valve position a fluidic connection is established between the conveying unit (175) and the first air duct (160) and in the second valve position a fluidic connection is established between the conveying unit (175) and the second air duct (165).
  2. Hand tool (10) after Claim 1 , - wherein in the first valve position the first air channel (160) is fluidically connected to the conveying unit (175) and the second air channel (165) is fluidically separated from the conveying unit (175), - wherein in the second valve position the second air channel (165) is fluidically connected to the conveying unit (175) and the first air channel (160) is fluidically separated from the conveying unit (175).
  3. Hand tool (10) according to one of the Claims 1 or 2 , - wherein the valve (170) has a third valve position, - wherein in the third valve position the first air channel (160) and the second air channel (165) are fluidically separated from the conveying unit (175).
  4. Hand tool (10) after Claim 3 , - wherein the blowing device (30) has a venting channel (301), - wherein the venting channel (301) is connected on one side to the valve (170) and opens on another side into an environment (305) of the hand tool (10), - wherein in the third valve position the venting channel (301) is fluidically connected to the conveying unit (175).
  5. Hand-held power tool (10) according to one of the preceding claims, - wherein the conveying unit (175) has a fan wheel (300) arranged non-rotatably on a drive shaft (65) of the drive motor (60), - wherein the valve (170) has a valve housing (270) and a valve body (235) rotatably mounted about the axis of rotation (213) with an annular section (240), - wherein the annular section (240) radially surrounds the fan wheel (300) on its outer side, - wherein the annular section (240) has a first valve opening (260) and a second valve opening (265) arranged circumferentially offset from the first valve opening (260), - wherein in the first valve position the first valve opening (260) has a first overlap with a first valve channel (290) of the valve housing (270) and the annular section (240) closes a second valve channel (295), - wherein the first valve channel (290) is fluidically connected to the first air channel (160) and the second valve channel (295) is fluidically connected to the second air channel (165), - wherein in the second valve position the annular section (240) is arranged rotated circumferentially about the axis of rotation (213) relative to the first valve position, - wherein in the second valve position the first valve opening (260) is spaced apart from the first valve channel (290) and the annular section (240) closes the first valve channel (290), - wherein in the second valve position the second valve opening (265) has a second overlap with the second valve channel (295).
  6. Hand tool (10) after Claim 5 , - wherein the valve housing (270) circumferentially surrounds the ring section (240) with an inner circumferential side (27) and rotatably mounts the ring section (240) about the axis of rotation (213), - wherein the valve body (235) has at least one actuating lever (245, 250) extending radially outwards, - wherein the actuating lever (245, 250) is connected to the ring section (240), - wherein the housing (20) has at least one recess (280, 285), - wherein the recess (280, 285) opens onto an outer circumferential side (255) of the hand tool device (10), - wherein the actuating lever (245, 250) extends through the associated recess (280, 285).
  7. Hand tool (10) after Claim 5 or 6 , - comprising a gearbox (70), - wherein the gearbox (70) is connected on the input side to the drive motor (60) and on the output side to the tool holder (40), - wherein the gearbox (70) is configured to convert a rotary movement of the drive motor (60) into an oscillating movement of the tool holder (40), - wherein the first air channel (160) is guided at least partially around the gearbox (70) on a side of the gearbox (70) facing away from the cutting area (110).
  8. A hand-held power tool (10) according to one of the preceding claims, - comprising a saw blade (85) with a saw section (90) and a shank (95) connected to the saw section (90), - wherein the shank (95) engages in and is connected to the tool holder (40), - wherein the saw section (90) is plate-shaped, and at least one row of teeth (100) of saw teeth (105) is arranged exclusively on a single side surface, - wherein the first air channel (160) is configured to guide the airflow (330) on a side facing the row of teeth (100) substantially parallel to the saw section (90) or inclined obliquely towards the row of teeth (100).
  9. hand-held power tool (10) according to one of the preceding claims, wherein the partial area (210) is arranged at an angle of 0° to 20° to the receiving axis (75).

Description

The invention relates to a hand-held power tool, in particular a jigsaw with a blowing device according to claim 1. State of the art Out of DE 10 338 602 B3 A motor-driven saw is known, comprising a housing, a cutting area, and a motor cooled by a fan. The fan draws air into the housing via an air intake duct system and, after passing the motor, expels it from the housing via an exhaust duct system. In the cutting area, a saw blade attached to the saw cuts a guide plane defined by a guide device, within which the saw can be positioned against a workpiece. The exhaust duct system has an exhaust outlet for supplying air to the cutting area. The exhaust duct system also has a second exhaust outlet on an end face of the housing, located above the cutting area and directed towards the guide plane, over which a curtain of blown air extending transversely to the cutting plane can be stretched. Further solutions for chip removal in hand-held power tools are also known. US 2003 / 0 121 389 A1 and the writing US 4 870 755 A Each reveals a frontal air blower for cleaning the cutting area. The writing DE 10 2008 041 094 A1 shows an alternative device for chip removal. The text WO 2008 / 000 544 A1 describes the routing of an air duct around a gearbox, and the writing EP 0 221 652 A1 reveals a valve for switching between a blowing and a suction function. The purpose of the invention is to provide an improved hand-held power tool. Disclosure of the invention This task is accomplished using a hand-held power tool according to claim 1. Advantageous embodiments are specified in the dependent claims. It was recognized that an improved handheld power tool, in particular an improved jigsaw, for producing a feed-directed cut in a workpiece can be provided by the handheld power tool comprising a tool holder, a cutting area, a housing, a support device for supporting the handheld power tool on the workpiece to be machined, in particular a base plate, and a blowing device. The housing has a lower housing surface and an end housing surface. The tool holder is configured to receive an insert tool, in particular a saw blade, along a receiving axis. The support device can be placed against the workpiece in a guide plane. The receiving axis intersects the guide plane in a cutting area. The blowing device has a first air channel and is configured to provide an airflow. A first channel opening of the first air channel is arranged on the lower housing surface on a side of the housing opposite the cutting area in the feed direction, in front of the tool holder. The first air channel has a sub-section adjoining the first channel opening. This sub-section is arranged perpendicular to the guide plane or inclined at an angle to the guide plane. The first channel opening is designed to direct the airflow into the cutting area. This design has the advantage that any sawdust produced during sawing, which might obstruct the view of the cutting line on the workpiece, is reliably removed from the workpiece by the airflow. Furthermore, it prevents the airflow from being disrupted when it enters the cutting area, for example, by the cutting tool itself. An alternative embodiment of an improved hand-held power tool can be provided by the hand-held power tool having a blowing device, wherein the blowing device has a first air duct and a valve and is configured to provide an airflow, wherein the valve has a valve housing and a valve body rotatably mounted about the axis of rotation between a first valve position and a second valve position, the valve body having an annular section, the annular section having a first valve opening and the valve housing having a first valve duct, wherein in the first valve position the valve duct and the first valve opening have an overlap, and wherein the first valve duct is connected downstream to the first air duct. According to the invention, the blowing device has at least a second air duct and a conveying unit, wherein the conveying unit is configured to convey the airflow during operation. The conveying unit is fluidically connected to the second air duct, the second air duct opening at a distance from the second duct opening towards the cutting area. The second duct opening is arranged on a side of the tool holder facing away from the housing end face. The second air duct is configured to guide at least a portion of a further airflow towards the cutting area during operation of the hand-held power tool. The provision of the two air channels ensures reliable blowing off of the shavings. According to the invention, the blowing device further comprises a valve, wherein the valve has a first valve position and a second valve position. The valve is fluidically connected to the conveying unit on the inlet side. The valve is fluidically connected to the first air channel and the second air channel on the outlet side. In the first valve position, the first air channel is fluidly connected to the conveying unit. In the seco