JP2010058223A - Air pressure type screw driving machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To secure an exhaust passage, and to prevent a noise reducing effect of exhaust noise from being impaired even if a filter is frozen. <P>SOLUTION: An air pressure type screw driving machine operates a striking mechanism of a drive screw and an air motor 7 for tightening a driven drive screw by compressed air, and discharges exhaust air from the striking mechanism and exhaust air from the air motor 7 from the rear of the air motor 7 through an exhaust pipe 17 arranged at the side part of the air motor 7. In the air pressure type screw driving machine, the exhaust pipe 17 of the exhaust air is formed between the side of the air motor 7 and a motor housing 14, the outlet of the exhaust pipe 17 is formed between the rear of the air motor 7 and the rear of the motor housing 14, and a first filter 21 having a cross section smaller than the cross section of the exhaust pipe 17 is arranged inside the exhaust pipe 17. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention is a pneumatic screw driving machine that is driven by an air motor and then tightened by driving a driving screw. The present invention relates to a pneumatic screw driving machine capable of securing exhaust air.

  In general, a pneumatic screwing machine operates a hammering mechanism with compressed air in an air chamber provided in a screwing machine body to drive a driving screw into a material to be driven to a certain depth, and then the above air chamber. The compressed screw passing through another path is rotated by an air motor to tighten the driving screw.

By the way, although the compressed air which actuated the striking mechanism and the compressed air which actuated the air motor are exhausted to the outside, the compressed air which actuated the striking mechanism has been exhausted from the upper end of the screwdriver main body. Since the exhaust part is close to the grip of the screwdriver, the exhaust air compressed during exhaust is blown out near the operator's wrist, and the exhaust noise at that time is slightly loud. There has been proposed a pneumatic screwing machine that discharges together with the discharged air (see Patent Document 1). The air motor is disposed below the grip, and the discharged air is discharged from the rear of the air motor, so that it is not blown onto the operator's arm or the like.
Japanese Patent No. 3520444

  However, according to the above-described exhaust structure, when tightening is performed in a low sound environment or in a high humidity environment, the filter filled in the exhaust pipe may freeze due to adiabatic expansion and the exhaust pipe may be blocked. . If the exhaust pipe is blocked, exhaust failure occurs, so that problems such as the striking piston of the striking mechanism not returning, the rotational force of the air motor weakening, and the tightening of the driving screw become loose.

  Further, since the exhaust air from the striking mechanism and the exhaust air from the air motor pass through the same exhaust pipe, the exhaust pressure increases, and the exhaust noise generated from the exhaust pipe increases. Moreover, when the filter filled in the exhaust pipe freezes, the exhaust sound from the air motor is transmitted to the housing of the air motor through the filter, and the motor housing vibrates and generates a large noise.

  The present invention solves the above problems, and even if the filter freezes when working in a bad environment, it is possible to secure an exhaust passage, and a pneumatic screw that does not greatly impair the sound reduction effect of the exhaust sound. The challenge is to provide a hammering machine.

  In order to solve the above-mentioned problem, the invention according to claim 1 is directed to a striking mechanism for striking a driving screw by a compressed air from an air chamber so that the head is lifted, and to further rotate the driving screw that has been driven. A pneumatic screw driving machine that operates an air motor to be tightened and exhausts exhaust air from the striking mechanism and exhaust air from the air motor through an exhaust pipe provided in a side portion of the air motor from behind the air motor. An exhaust pipe for the exhaust air is formed between the side portion of the air motor and the motor housing, and an outlet of the exhaust pipe is formed between the rear part of the air motor and the rear part of the motor housing. A first filter having a cross-sectional area smaller than the cross-sectional area of the exhaust pipe line is arranged inside the path.

  The invention according to claim 2 is characterized in that, in claim 1, a second filter is attached to the inner surface of the exhaust pipe and a third filter is arranged at the outlet of the exhaust pipe.

  According to a third aspect of the present invention, in the first or second aspect, the first filter is formed by bending a metal net having a filter material disposed therein, and an end portion on the exhaust gas upstream side of the filter material is disposed on the metal net. It protruded from the end of the.

  According to the first aspect of the present invention, since the exhaust air discharged from the exhaust port of the air motor passes through the first filter when passing through the exhaust pipe, the exhaust sound generated by the air motor is generated by the first filter. Since the sound is absorbed and reduced, the exhaust sound can be made quieter.

  An exhaust pipe for the exhaust air is formed between the side of the air motor and the motor housing, and an outlet of the exhaust pipe is formed between the rear part of the air motor and the rear part of the motor housing. Since the first filter having a cross-sectional area smaller than the cross-sectional area of the exhaust pipe line is disposed inside the path, a space for allowing air to pass is formed between the exhaust pipe line and the first filter. The Therefore, even if the first filter freezes when working in a low-humidity or high-humidity environment, the exhaust passage can be secured. Therefore, exhaust failure, striking piston return failure, air motor rotation, etc. Problems such as power loss are resolved.

  Further, by arranging the first filter as described above, even if the filter freezes, the first filter is smaller than the cross-sectional area of the exhaust pipe. Since it is difficult to transmit to the housing, the sound from the motor housing can be kept small.

  According to the invention of claim 2, since the second filter is attached to the inner surface of the exhaust pipe and the third filter is disposed at the outlet of the exhaust pipe, the first filter is frozen. Since the second filter and the third filter are difficult to freeze, the exhaust noise generated from the exhaust pipe can be effectively reduced.

  According to the third aspect of the present invention, the first filter is formed by bending a metal mesh having a filter material disposed on the inside thereof, and has an end on the upstream side of the filter material protruding from the end of the metal mesh. Therefore, the part protruding by the discharge air is compressed and swells more than the end of the metal mesh, and this swelled part is caught by the end of the metal mesh and does not enter the interior of the metal mesh, so it is compressed in the longitudinal direction. This phenomenon does not occur. Therefore, it is possible to solve the problem that the filter is compressed by the exhaust air and the original sound reduction effect cannot be obtained.

  FIG. 1 and FIG. 2 show a cross section of the main part of the screw driving machine, and this screw driving machine is provided with an impact mechanism and a screw tightening mechanism provided in the screw driving machine main body A. FIG. The striking mechanism has a striking cylinder 1, a striking piston 2 slidably provided in the striking cylinder 1, and a driver bit 3 integrally coupled to the striking piston 2. The main valve 4 is operated to open, and compressed air is supplied from the air chamber 5 (connected to the air supply source) that stores compressed air into the striking cylinder 1 to drive the driver bit 3 having a polygonal cross section. It is something to be made.

  The screw tightening mechanism includes a drive gear 6c, an intermediate gear 6b, and an air motor 7 fitted to the driver bit 3, and transmits the power of the air motor 7 to the drive gear 6c to drive the driver bit 3 to rotate. Thus, it operates almost simultaneously with the start of the operation of the striking mechanism and rotates the driver bit 3 around its axis, thereby tightening a driving screw (not shown) driven by the driver bit 3.

  The driver bit 3 hits the driving screw by the driving mechanism and drives the driving screw so that the head of the driving screw floats against the material to be driven, and then tightens the driving screw by the screw tightening mechanism. The striking mechanism and the screw tightening mechanism are known mechanisms as known from Japanese Patent Laid-Open Nos. 9-141571 and 9-29037.

  A cylindrical space 9 is formed between the air chamber 5 and the striking cylinder 1. When the air chamber 5 is opened to the striking cylinder 1, the compressed air in the air chamber 5 passes through the annular space 9. It is comprised so that it may be supplied to the striking cylinder 1 via.

  A main valve 4 is disposed around the head portion of the impact cylinder 1. The main valve 4 is formed in an annular shape, and its lower end surface is provided so as to be able to engage with the upper end seal portion 8 on the inner wall of the air chamber 5 by sliding in the vertical direction. At the time of standby, compressed air is supplied from the trigger valve 10 to the valve upper chamber 12 as shown in FIG. 2, the main valve 4 is lowered to the bottom dead center by the air pressure of the compressed air and the pressure of the spring 11, and the lower end of the air is at the lower end. The upper end seal portion 8 of the inner wall of the chamber 5 is engaged, thereby closing the air chamber 5 with respect to the striking cylinder 1.

  On the other hand, when the screw is driven, the trigger 13 is pulled and the trigger valve 10 is operated to discharge the compressed air in the valve upper chamber 12, so that the compressed air in the air chamber 5 is discharged as shown in FIG. The main valve 4 is moved upward against the spring 11 by the air pressure to open the air chamber 5 to the striking cylinder 1, supply compressed air to the striking cylinder 1 to drive the striking piston 2, and A driving screw (not shown) is driven to a certain extent.

  Compressed air is supplied from the air chamber 5 to the striking cylinder 1, and is supplied into the motor housing 14 from the air supply port 15a on the front end wall of the motor housing 14 of the air motor 7 through the air passage 20 in FIG. Acts on the rotor 16 to rotate it. As shown in FIG. 1, this rotational force is transmitted from the tip gear 6a of the rotor 16 to the drive gear 6c via the intermediate gear 6b to rotate the driver bit 3 and tighten the driving screw. After the compressed air is discharged from the exhaust port 15 b of the air motor 7, the compressed air passes through the exhaust pipe 17 provided between the side portion of the air motor 7 and the motor housing 14 shown in FIG. 4 and passes through the rear portion of the air motor 7 and the motor housing 14. It is discharged from the pipe outlet 18 at the rear end of the discharge space 18a formed between the rear portion and the rear portion.

  When the driving screw reaches a predetermined screw tightening depth, a stop valve (not shown) is operated to shut off the air passage 20 and stop the air motor 7.

  After the tightening of the screw, when the trigger 13 is released and the main valve 4 is moved to the bottom dead center by the trigger valve 10, it is supplied into the striking cylinder 1 to drive the striking piston 2, as shown in FIG. The compressed air passes through the exhaust passage 17a, passes through a passage 17b formed continuously on the exhaust upstream side of the exhaust pipe 17 of the air motor 7 shown in FIG. 4, and merges with the exhaust air from the air motor 7 to form the exhaust pipe. 17 is discharged.

  By the way, a sponge-like filter is arranged inside the exhaust pipe 17 so that the sound generated from the air motor 7 is reduced.

  That is, the first filter 21 is disposed inside the exhaust pipe 17 and is supported by appropriate support means. As shown in FIGS. 6A and 6B, the first filter 21 is formed by disposing the filter material 25 inside the metal mesh 24 and bending the metal mesh 24 into a U shape. Note that the exhaust gas upstream end 25 a of the filter material 25 protrudes from the end of the metal mesh 24.

  The first filter 21 is formed to be smaller than the cross-sectional area of the exhaust pipe line 17. Preferably, the air motor 7 is provided near the exhaust port 15b. As a result, as shown in FIG. 5, a space S is formed in the exhaust pipe 17 between the upper and lower portions of the first filter 21 and the inner surface of the motor housing 14.

  According to the above configuration, the exhaust air discharged from the exhaust port 15b of the air motor 7 passes through the first filter 21 when passing through the exhaust pipe line 17, so that the exhaust sound generated by the air motor 7 is the first filter. Since the sound is absorbed and reduced at 21, exhaust sound can be made quieter.

  By the way, since the exhaust air exhausted from the exhaust port 15b of the air motor 7 rapidly expands in the exhaust conduit 17, the temperature in the exhaust conduit 17 decreases due to adiabatic expansion, and the first filter 21 freezes. Such a tendency becomes more conspicuous when the sound is low or in a humid environment. However, as shown in FIG. 5, the first filter 21 is smaller than the cross-sectional area of the exhaust pipe line 17, and there is a space S between the upper and lower portions of the first filter 21 and the inner surface of the motor housing 14. These space portions S serve as exhaust air passages. Therefore, even if the first filter 21 freezes when working in a low-humidity or high-humidity environment, the exhaust passage can be secured. Therefore, exhaust failure, striking piston return failure of the striking mechanism, air motor Problems such as reduced rotational force are eliminated.

  Further, by arranging the first filter 21 as described above, even if the filter freezes, the first filter 21 is smaller than the cross-sectional area of the exhaust pipe line 17, so that the sound generated by the air motor 7 is filtered. Therefore, the sound from the motor housing 14 can be kept small.

  Further, the exhaust air from the striking mechanism and the exhaust air from the air motor 7 move from the left upstream side to the right downstream side in FIGS. 4 and 6, so that the first filter 21 is compressed in the longitudinal direction. . If the first filter 21 is compressed, the exhaust pipe 17 is clogged or the sound absorption effect is reduced. However, the exhaust gas upstream end 25a of the filter material 25 has a structure protruding from the end of the metal mesh 24, and the protruding portion is compressed by the exhaust air and swells more than the end of the metal mesh 24. The end 24 a of the metal net 24 bites into the filter material 25. For this reason, even if the pressure of compressed air acts on the end of the filter material 25, the filter material 25 is caught by the end of the metal mesh 24 and does not enter the inside of the metal mesh 24, so it is compressed in the longitudinal direction. This phenomenon does not occur. Therefore, the problem that the first filter 21 is compressed by the exhaust air and the original sound reduction effect cannot be obtained can be solved.

  In addition, the metal net | network 24 and the filter material 25 are not limited to the example bent in a U shape. For example, it may be a “no” shape or an O shape.

  Next, it is preferable to arrange the second filter 22 on the inner wall of the motor housing 14 as shown in FIG. According to this configuration, even if the first filter 21 is frozen, the exhaust sound generated by the air motor 7 is absorbed by the second filter 22 and the exhaust sound is directly transmitted to the motor housing 14. Since it becomes difficult, exhaust sound is sufficiently reduced.

  Note that the first filter 21 and the second filter 22 do not have to be separate. As shown in FIG. 8, they may be integrated. Also in this case, only the first filter 21 freezes, and the second filter 22 can absorb the exhaust sound.

  Furthermore, it is preferable to arrange a third filter 23 at the outlet of the exhaust pipe 17 as shown in FIG.

  According to the above configuration, since the second filter 22 and the third filter 23 are added to the first filter 21, the sound reduction effect of the exhaust sound is sufficiently increased. And since the 2nd filter 22 and the 3rd filter 23 become difficult to freeze because the 1st filter 21 freezes intensively, the exhaust sound generated from the exhaust line 17 can be reduced effectively. it can.

Vertical section of pneumatic screwdriver Sectional drawing of the principal part which shows the state at the time of the completion | finish of driving | running | working of the said screw driving machine (and standby) Sectional drawing of the principal part which shows the state at the time of driving of the said screw driving machine Sectional view on the XX line of FIG. Sectional view on the YY line of FIG. (A) (b) is a side view and a cross-sectional view of the first filter Cross-sectional view showing a state in which the second filter is attached in the same cross section as FIG. The cross-sectional view which shows the state which integrated the 1st filter and the 2nd filter with the same cross section as FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Stroke cylinder 2 Stroke piston 3 Driver bit 5 Air chamber 7 Air motor 14 Motor housing 17 Exhaust pipe 21 1st filter 22 2nd filter 23 3rd filter 24 Metal mesh 25 Filter material

Claims (3)

Operates the striking mechanism that strikes the driving screw by the compressed air from the air chamber to the extent that the head is lifted, and the air motor that rotates and tightens the driving screw that is driven further, and discharges from the striking mechanism. In a pneumatic screw driving machine that exhausts air and exhaust air from the air motor through an exhaust pipe provided on the side of the air motor and exhausts it from the rear of the air motor.
The exhaust air exhaust line is formed between the side of the air motor and the motor housing, and the outlet of the exhaust line is formed between the rear part of the air motor and the rear part of the motor housing, A pneumatic screw driving machine characterized in that a first filter having a cross-sectional area smaller than the cross-sectional area of the exhaust pipe is disposed inside.   The pneumatic screw driving machine according to claim 1, wherein a second filter is attached to the inner surface of the exhaust pipe line, and a third filter is disposed at the outlet of the exhaust pipe line.   The first filter is formed by bending a metal net having a filter material disposed therein, and an end of the filter material on the exhaust upstream side protrudes from an end of the metal net. The pneumatic screwdriver according to 1 or 2.

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