JPH0244672B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a compressed air driver having a driver motor configured as a compressed air motor and a device for sucking and holding a screw with suction air generated by an ejector action. The present invention relates to a device having a probe and holding sleeve surrounding the screw-in tool, to which a negative pressure passage connected to an ejector nozzle is connected.

PRIOR ART A driver of the above type is known from US Pat. No. 2,570,164. In this driver, the ejector nozzle is connected to a chamber containing supply air via a branched auxiliary air passage on the compressed air supply side to the driver motor. In this case, both the exhaust air from the negative pressure passage and the exhaust air from the driver motor are blown out to the side from the compressed air driver through the same opening. In this case, the intake air exhaust and the driver motor exhaust directly face each other, so that the two exhaust streams flow in opposite directions. The prevailing exhaust flow of the driver motor creates a damming pressure during screw-driving operation, so that the screw that has been sucked falls out. Moreover, when the compressed air type driver configured as described above is operated, the noise generated is large, and the movement of air generated during operation causes discomfort to the operator.

Furthermore, according to Japanese Utility Model Publication No. 41-12714, it is known to connect the exhaust air of a driver motor to an ejector nozzle to generate a suction air flow to attract screws. However, when the ejector action is generated by the exhaust of the driver motor, it is necessary to operate the compressed air driver empty for some time before the compressed air driver can suction the screw, and compressed air is wasted. It will be consumed. Also, since the screw-driving tool is already rotating at a relatively high speed when the screw is sucked, it becomes difficult for the screw slit to engage with the screw-driving tool.
Furthermore, exhaust gas with reduced pressure cannot generate a sufficient ejector action. Moreover, even in this compressed air type driver, the exhaust is performed to the side of the compressed air type driver, so the movement of air caused by the exhaust causes discomfort to the operator. Furthermore, in this case an air connection is provided on the outside of the casing of the compressed air driver in order to connect the exhaust part of the driver motor with the ejector nozzle of the probe and holding sleeve, so that said air connection is connected to this compressed air. This will interfere with work using a screwdriver.

Problems to be Solved by the Invention The problems to be solved by the present invention are to improve the compressed air type driver mentioned at the beginning so that even when the driver motor rotates, the attached screws do not fall out. The amount of compressed air consumed by the compressed air driver is reduced, and the groove of the screw is easily engaged with the screwing tool when tightening the screw, and the exhaust from the compressed air driver causes discomfort to the worker. The objective is to prevent this from happening and to make it easier to work with a compressed air driver.

Means for Solving the Problem The means for solving the problem according to the invention is that in a compressed air driver of the type mentioned at the outset, a negative pressure passage passes through a probe and holding sleeve in the casing of the compressed air driver. The supply air connection of the driver motor extends from the ejector nozzle to the ejector nozzle, and the supply air connection of the driver motor has an auxiliary air passage through which the compressed air flows into the ejector nozzle and through which the air flowing out from the ejector nozzle is adapted to be exhausted via an exhaust connection provided in the rear casing part located at a distance from the probe-and-holding sleeve, and the air directed to the ejector nozzle for producing the ejector action. The air flow and the suction air flow generated by the ejector action are routed to the exhaust connection of the driver motor via a common connection passage, and a check valve is arranged in the negative pressure passage. The purpose of the check valve is to allow the suction air to flow through without being obstructed, but to block backflow air generated from the exhaust side of the driver motor during rotation of the driver motor.

Effects of the Invention In the compressed air driver according to the present invention,
Since the exhaust of the driver motor is cut off from the negative pressure passage that generates the suction airflow, the exhaust of the driver motor no longer forms a damming pressure against the suction airflow, preventing the screws from falling out and preventing the ejector action. The supply air connection of the driver motor has an auxiliary air passage through which the compressed air flows into the ejector nozzle, so that the screw is closed before the driver motor rotates. The compressed air consumption of a compressed air driver is significantly lower than when the ejector action is generated by the exhaust of the driver motor, and the screw is attracted before the screw-driving tool rotates at high speed. ,
The groove of the screw that has been sucked becomes easier to engage with the screwing tool. Furthermore, since a negative pressure passage for generating suction air is provided inside the casing of the compressed air driver, there is no pipe line protruding from the casing of the compressed air driver, making it easier to work with this compressed air driver. It becomes easier to do. Moreover, in the configuration of the compressed air driver according to the invention, the air exiting from the ejector nozzle is
Since the air is evacuated via the exhaust connection provided in the rear casing part, the exhaust of the suction air does not result in air movements that could cause discomfort to the operator. Moreover, the exhaust from the driver motor and the exhaust from the intake air can be guided to a common exhaust connection.

Embodiments Advantageous embodiments of the invention are defined in claim 2.
It is described in paragraphs 9 through 9. It is particularly advantageous to provide the exhaust connection of the driver motor with a silencer or to connect this exhaust connection to a central suction device.

Embodiment In the embodiment shown in FIG. 1, the casing 1 of the compressed air driver contains a driver motor 2, and the rear casing part 3 has a valve 4, an ejector nozzle 5, a check valve 6, and a shutoff valve. A valve 7 is provided. An air supply connection 8 and an exhaust connection 9 are fixed to the rear housing part 3 .
The exhaust opening of the ejector nozzle 5 opens into a connecting channel 10 to the exhaust connection 9 . The exhaust connection 9 is formed by a muffler 11 in the exemplary embodiment shown. A coupling casing 12 connects the casing 1 with a probe and holding sleeve 13 . In this case, the coupling housing 12 is sealed to the housing 1 by a sealing disc 14 . The sealing disc 14 is connected to the negative pressure passage 1 in the casing 1.
6 with the inner chamber of the coupling casing 12
5. The connecting casing 12 is the driving body 1
7, the drive body 17 itself forming a receiving device 18 for a screw-in tool 19.
This drive body 17 can be driven by a driver motor 2 in a known manner (not shown). The valve 4 has a nozzle opening 20 for the supply air of the driver motor 2, an auxiliary air passage 21 and a hole 22.
A supply air connection 8 is screwed into the bore 22 . Before screwing in the supply air connection 8, a ball 23 and a pressure spring 24 are inserted into the hole 22. Said pressure spring 24, of which the supply air connection 8 is used as a spring catch, presses the ball 23 against the conical outlet of the hole 22 opening into the nozzle opening 20. The auxiliary air passage 21 is not closed off by the ball 23. The auxiliary air passage 21 opens into an air passage 25 of an adjacent ejector nozzle 5, which itself reaches a nozzle opening 26. This nozzle opening 26
is connected to a nozzle hole 27, and a nozzle hole 28 is connected to the nozzle hole 27. This nozzle hole 2
8 communicates with the negative pressure channel 16 via an interior chamber which receives the ball 29 of the check valve 6 . Nozzle hole 2 of valve 4
A pin 30 projects into the housing 1, the remaining part of which is guided in a hole 31 in the casing 1. One end of the pin 30 is in contact with the ball 23. The pin 30 detects the vertical movement of the screwing tool 19 when a screw is inserted into the corresponding screw hole, and the ball 2
3 from the conical seat and open the supply air opening to the driver motor 2. As the shutoff valve 7, a screw 32 having a sealing plate capable of closing the nozzle hole 27 is used.

If you want to suction and hold the screw with negative pressure,
Shutoff valve 7 is opened (FIG. 1). Supply air connection 8
The air supplied via the auxiliary air channel 21 and an air channel 25 with a nozzle opening 26 flows through the nozzle opening 27 into the connecting channel 10 . At this time, the air is entrained through the nozzle hole 28, so that a suction air flow is created in the negative pressure passage 16, the connecting casing 12 and the searching and holding sleeve 13. Once a screw has been sucked, it is pushed with the screw-in tool 19 into the hole provided for screwing it. This pressing force overcomes the force of the pressing spring 24 and opens the nozzle opening 20 for the supply air that drives the driver motor 2.
open. When the exhaust gas of the driver motor 2 exits, an overpressure is created in the connecting channel 10 , which acts on the ball 29 in the check valve 6 via the nozzle holes 27 and 28 . This ball 29 closes the opening to the vacuum passage 16. When the screwing process is finished and the screwdriver is released from the screw, the pressure spring 24 closes the nozzle opening 20 with the ball 23 again. The air then flows again through the auxiliary air channel 21 to the connecting channel 10 and the suction process can be started anew.

In the embodiment of FIG. 2, the isolation valve 7 is replaced by another valve structure. This valve structure has a sealing cone 34 at the inner end and an operating knob 35 at the outer end.
It has a rod 33 that holds the. This rod 33 is guided in a hole 36 in a closure lid 37 that closes off the housing 1 on the back side. Operation knob 3
5 and the closing lid 37
attempts to keep the sealing cone 34 in contact with the sealing seat of the air passage 25 at all times.

In order to generate a suction air flow in this embodiment, the operating knob 35 must be pushed towards the closure lid 37. The subsequent mode of operation is as described in the embodiment of FIG.

[Brief explanation of the drawing]

The drawings show a plurality of embodiments of the compressed air driver according to the present invention, and FIG. 1 is a longitudinal sectional view of the first embodiment of the compressed air driver of the present invention;
2 is a partial sectional view of the rear casing portion of the compressed air driver of FIG. 1; FIG. DESCRIPTION OF SYMBOLS 1...Casing, 2...Driver motor, 3...Casing part, 4...Valve, 5...Ejector nozzle, 6
...Check valve, 7...Shutoff valve, 8...Supply air connection, 9
...exhaust connection part, 10...connection passage, 11...silencer,
12... Connection casing, 13... Exploration and holding sleeve, 14... Seal disk, 15... Opening, 16... Negative pressure passage, 17... Drive body, 18... Receiving device, 19... Screw-in tool, 20... Nozzle opening, 21... Sub-air passage, 22... Hole, 23... Ball, 24... Pressing spring, 25
...Air passage, 26... Nozzle opening, 27, 28... Nozzle hole, 29... Ball, 30... Pin, 31... Hole, 32
...Screw, 33...Rod, 34...Seal cone, 35
...operation knob, 36...hole, 37...closing lid, 38...pressing spring.

Claims (1)

[Scope of Claims] 1. A compressed air driver having a driver motor configured as a compressed air motor and a device for suctioning and holding a screw with suction air generated by an ejector action, which is capable of removing a screwing tool. In the case of a type having an enclosing probe and holding sleeve, to which a vacuum passage connected to the ejector nozzle is connected, the vacuum passage 16 probes and carries the inside of the casing 1 of the compressed air driver. Extending from the retaining sleeve 13 to the ejector nozzle 5 , the supply air connection 8 of the driver motor 2 has an auxiliary air channel 21 via which compressed air flows into the ejector nozzle 5 . The air exiting from the ejector nozzle 5 is exhausted via an exhaust connection provided in the rear casing part 3, which is located at a distance from the probe and holding sleeve 13, so that the ejector action ejector nozzle 5 to generate
The airflow sent to the airflow and the suction airflow generated by the ejector action are sent to the exhaust connection 9 of the driver motor 2 via a common connection path 10, and the negative pressure path A check valve 6 is disposed in the interior of the driver motor 16, and the check valve 6 allows the suction air to flow through without being obstructed, but blocks backflow air generated from the exhaust side of the driver motor 2 while the driver motor 2 is rotating. A compressed air driver characterized by: 2. The device according to claim 1, further comprising manually operable valves 7, 33 to 35 for blocking the air flow branched off from the supply air for the driver motor 2 and thus the suction air flow. Compressed air driver. 3. Compressed air driver according to claim 2, wherein the valve is configured as a screw valve 7. 4 said valve 34 is held in the closed position by the action of a spring 38 and a handle 35 for opening said valve 34;
A compressed air driver according to claim 2, which is coupled to a push rod 33 having a push rod. 5. A driver casing 1 incorporating a driver motor 2, an ejector nozzle 5, and a valve for regulating air supplied to the driver motor 2 is connected to the exploration and holding sleeve 13 via a connection casing 12. The compressed air driver according to any one of the ranges 1 to 4. 6. Claim 5, wherein a negative pressure passage for suction air is formed in the driver casing 1, and the connecting casing 12 and the searching and holding sleeve 13 are used as a whole as the suction air passage. The compressed air driver described. 7. A seal disk 14 is interposed between the driver casing 1 and the connection casing 12, and the seal disk 14 connects the negative pressure passage 16 in the driver casing 1 with the inner chamber of the connection casing 12. The compressed air type driver according to claim 5 or 6, having an opening 15 for. 8. The compressed air driver according to claim 1, wherein a muffler is disposed at the exhaust connection portion of the driver motor. 9. The compressed air driver according to any one of claims 1 to 8, wherein the exhaust connection of the driver motor can be connected to a central suction device.