Search

DE-102013203702-B4 - Pneumatic drive motor

DE102013203702B4DE 102013203702 B4DE102013203702 B4DE 102013203702B4DE-102013203702-B4

Abstract

A pneumatically operated drive machine (1) for an oscillating saw or file as a tool, comprising a tool housing (3) for a motor housing (17) mounted longitudinally displaceably in the tool housing (3), with a longitudinally oscillating piston (21) inserted therein, having a piston rod (23) attached thereto which can be connected to the tool, and a valve (25) inserted in the tool housing (3) for alternately supplying the two end faces of the piston in the motor housing (17) with supply air, wherein the supply air, after an actuating valve (35) connected to a compressed air source, passes through a cylinder (46) penetrating the rear end of the motor housing (17) in a sealed manner and traversing the rear displacement section (15") for the motor housing (17) in the tool housing (3), with a blind-hole supply air bore (45), directly into the interior of the motor housing. (17) is introduced, wherein both end faces of the engine housing (17) have substantially the same cross-sectional areas and the two displacement sections (15', 15") bounding the end faces of the engine housing (17) are connected to each other, such that the application of pressure to both end faces of the The pressure of the motor housing (17) is essentially identical to the pressure of the exhaust air, so that regardless of the level of the supply and exhaust air pressure, no displacement of the motor housing (17) occurs in the bore (13) of the tool housing (3), and the motor housing (17) is held in a central position by two springs (22, 24) when the operation is interrupted without air supply.

Inventors

  • Stefan Wiedemeier

Assignees

  • SUHNER INTERTRADE AG

Dates

Publication Date
20260513
Application Date
20130305
Priority Date
20120308

Claims (5)

  1. A pneumatically operated drive machine (1) for an oscillating saw or file as a tool, comprising a tool housing (3) for a motor housing (17) mounted longitudinally displaceably in the tool housing (3), with a longitudinally oscillating piston (21) inserted therein, having a piston rod (23) attached thereto which can be connected to the tool, and a valve (25) inserted in the tool housing (3) for alternately supplying the two end faces of the piston in the motor housing (17) with supply air, wherein the supply air, after an actuating valve (35) connected to a compressed air source, passes through a cylinder (46) penetrating the rear end of the motor housing (17) in a sealed manner and traversing the rear displacement section (15") for the motor housing (17) in the tool housing (3), with a blind-hole supply air bore (45), directly into the interior of the motor housing. (17) is introduced, wherein both end faces of the motor housing (17) have substantially the same cross-sectional areas and the two displacement sections (15', 15") bounding the end faces of the motor housing (17) are connected to each other, such that the application of the exhaust air pressure to both end faces of the motor housing (17) is substantially identical, so that regardless of the level of the supply and exhaust air pressure, no displacement of the motor housing (17) occurs in the bore (13) of the tool housing (3), and the motor housing (17) is held in a central position by two springs (22, 24) when the operation is interrupted without air supply.
  2. drive motor according to Claim 1 , characterized in that the pipe section (39) is firmly connected to the housing (3) and is axially guided in a bore (41) in the motor housing (17).
  3. drive motor according to Claim 2 , characterized in that at least two circumferential sealing means (43) are inserted between the pipe section (39) and the bore (41).
  4. Drive motor according to one of the Claims 1 until 3 , characterized in that radially extending holes (47) are formed at the end of the feed air bore (45), which ends between the sealing means (43), which open into a groove (51) which leads into the motor housing (17).
  5. drive motor according to Claim 4 , characterized in that the groove (51) is connected to the valve (25).

Description

The invention relates to a compressed air-operated drive machine for an oscillating saw or file according to the preamble of claim 1. Pneumatic drive machines are known in various designs from the prior art. One such drive machine is used in the EP 1 028 826 B1 The described device comprises a tool housing with a motor housing that is longitudinally displaceable within the tool housing. A piston with a piston rod, which penetrates the motor housing, is oscillating within the motor housing. Compressed air supplied to both sides of the piston is alternately directed to the two cylinder chambers by a reed valve. A file or saw, protruding from the tool housing, is attached to the free end of the piston rod by a fastening device. A compression spring rests against the motor housing at the tool-side end, pressing the motor housing backward, i.e., toward the compressed air supply side. The intended purpose is that, during operation, the motor housing is held in a central position within the cylinder chamber by the supply pressure of the compressed air, which presses against the rear end of the motor housing. During operation, that is, when air is supplied and thus when the piston oscillates in the motor housing, the motor housing can oscillate back and forth in the longitudinal direction within the tool housing in a damped manner, so that the transmission of the oscillating movement of the piston with the tool and thus the vibrations to the tool housing and the worker's hand is greatly dampened, or the movements are decoupled. Due to the one-sided application of the supply pressure to the longitudinally movable motor housing, the position of the motor housing within the tool housing shifts depending on the supply pressure, which is adjustable by the user. Other known drive systems are described in the documents DE 10 2010 015 484 A1 and JP 2007 - 203 446 A to be taken. This reveals the DE 10 2010 015 484 A1 A pneumatic saw or file with a working chamber in which a piston with a shaft is guided in a bushing and can move up and down. To drive the piston, compressed air is alternately directed into an upper and a lower part of the working chamber, the pneumatic motor having a control housing equipped with a reed valve through which this alternating introduction of compressed air is made possible. The JP 2007 - 203 446 A Disclosure reveals a compressed air-driven drive machine with a cylindrical housing in which two pistons are axially movable. A tool mounting element for holding a tool, such as a saw, is provided at a front end of the housing. The drive machine also includes a compressed air supply with a fixed shaft extending through the housing, which has a supply channel or feed air through-bore for supplying compressed air between the first and second pistons. The compressed air supply is connected to the supply channel at a rear end of the shaft and is connected to the supply channel via valves. The DE 698 06 320 T2 , US 2 899 934 A and DE 27 10 920 A1 further reveal drive machines in which it is fundamentally possible to introduce supply air into a motor housing of a compressed air-operated oscillating hand tool by means of a cylinder penetrating the motor housing in order to drive a piston to an oscillating movement. One object of the present invention is to eliminate the disadvantages of the known saw and to create a compressed air-operated drive machine in which the central position of the motor housing within the tool housing can be defined independently of the pressure of the supply air and independently of the pressure of the exhaust air. This problem is solved by a drive machine according to the features of patent claim 1. Advantageous embodiments of the drive machine are described in the dependent claims. The inventive drive motor eliminates the disadvantages of the known machine, solves the stated tasks, and achieves optimal vibration damping. The guide length of the tool holder 9 in the guide 49 increases because the central position of the motor housing remains unchanged. The supply and exhaust pressures can be varied over a wider range, thereby increasing the frequency and stroke ranges. Furthermore, the power of the drive motor, and consequently also of the saw or file, can be increased. The invention is explained in more detail using an illustrated embodiment. The illustrations show: 1 a longitudinal cut through a drive machine for a saw or file, 2 an enlarged section of the central part with the engine housing, the path of the supply air and the exhaust air colored grey, 3 A schematic representation of the engine housing (hatched), with grey underlining the spaces containing exhaust air that act on the end faces of the engine housing. Reference numeral 1 denotes a compressed air-operated drive machine. The drive machine 1 comprises a housing 3, at the rear end 5 of which supply air can be introduced. At the front end 7, a tool holder 9 for a file or saw (both not shown) protrudes from the housing