JP4174726B2 - Air nailer - Google Patents

Description

  The present invention relates to an air nailing machine (hereinafter simply referred to as a nailing machine) driven by compressed air, which reduces exhaust noise and pressure.

  In order to reduce the exhaust pressure and exhaust noise of pneumatic tools driven by compressed air, a method of reducing the pressure by expanding the compressed air in the expansion chamber, a method of reducing the pressure by restricting the flow rate of the compressed air with a throttle valve, and porous There are a method of reducing the pressure by the passage resistance of a muffler made of a quality material, a method of rectifying and reducing turbulent flow such as a vortex, and a method of reducing and reducing sound by canceling the opposite wavelengths together.

  In general, nailer exhaust includes exhaust of compressed air above the piston of the cylinder at the bottom dead center of the piston, exhaust of compressed air supplied to and discharged from the head valve chamber to operate the head valve, and head valve. There is exhaust of compressed air supplied to and discharged from the valve piston lower chamber in the trigger valve in order to operate.

  In the nailing machine having a structure as shown in Japanese Patent Laid-Open No. 8-336766 shown in FIG. 5, the pressure accumulating chamber is in the body 40 and the handle 18. The compressed air above the piston 7 of the cylinder 5 flows into the expansion chamber 10 provided on the upper side surface and the outer periphery of the nailing machine 1 via the exhaust valve 9 of the head valve 8 and is decompressed. Further, the pressure is reduced and the exhaust passes through a muffler made of a porous material or the like (not shown) and is discharged out of the nail driver 1. The compressed air in the head valve chamber 19 flows into the outer periphery of the valve piston 26 via the air passage 25, and then flows into the expansion chamber 10 via the exhaust valve 27 of the valve piston 26, and thereafter the compressed air above the piston. Similarly, it is discharged out of the nailing machine 1. The compressed air in the valve piston lower chamber 20 in the trigger valve 3 is directly discharged out of the nailing machine 1 through the exhaust valve 41 of the plunger 28.

  In the nailing machine shown in FIG. 6, the compressed air above the piston 7 of the cylinder 5 flows into the expansion chamber 10 provided in the top cover 42 via the exhaust valve 9 of the head valve 8 and is decompressed. After passing through a muffler 31 (not shown), the pressure is further reduced and rectified, and the sound is reduced and discharged to the outside of the nailer 1. The top cover 42 is provided so as to be rotatable in the circumferential direction as in, for example, registered utility model No. 2576553, and the exhaust direction can be arbitrarily changed. In addition, a click mechanism 39 is provided at the rotating portion of the top cover 42 and the exhaust cover 16 so that the exhaust direction is not changed by the exhaust pressure. The compressed air in the head valve chamber 19 flows into the outer periphery of the valve piston 26 through the air passage 25 and is directly discharged out of the nail driver 1 through the exhaust valve 27 of the valve piston 26. The compressed air in the valve piston lower chamber 20 in the trigger valve 3 is directly discharged out of the nailing machine 1 through the exhaust valve 41 of the plunger 28.

  In the nailing machine disclosed in Japanese Patent Laid-Open No. 8-39454 shown in FIG. 7, the compressed air above the piston 7 of the cylinder 5 is sent to the exhaust string at the rear end of the handle 18 via the exhaust valve 9 and the air passages 17 and 43 of the head valve 8. 30 is discharged from the inside of the nail driver 1 from the inside. As with the top cover 42 of the nailer shown in FIG. 6, the exhaust string 30 is provided so as to be rotatable in the circumferential direction, and the exhaust direction can be arbitrarily changed. The compressed air in the head valve chamber 19 flows into the trigger valve 3 through the air passage 25 and is then discharged from the exhaust string 30 to the outside of the nail driver 1 through the air passage 43.

  An air tool such as an air impact wrench shown in FIG. 8 flows into the air motor chamber 45 from the pressure accumulation chamber 4 through the variable flow rate trigger valve 3 and the air passage 44 and rotates the air motor 46 and then the outer periphery of the trigger valve 3. And is discharged out of the air tool through the air passage 47. The exhaust string 30 is provided with a muffler 31 that is rotatable in the circumferential direction for rectifying turbulent flow such as vortex, and the exhaust direction can be arbitrarily changed. The trigger valve 3 only connects / disconnects the pressure accumulating chamber 4 and the air passage 44, and does not discharge compressed air. In addition, since the air tool of FIG. 8 changes the flow rate by narrowing the passage area from the pressure accumulation chamber 4 to the air passage 44, the air passage 44 is decompressed compared to the pressure accumulation chamber 4. Further, the air motor 46 is rotated to reduce the pressure and discharged out of the air tool. Therefore, the exhaust pressure is lower than that of the nailer shown in FIGS. 5 to 7, and there is no problem only with the muffler 31 that rectifies some passage resistance and turbulent flow such as vortex. Is not provided.

JP-A-8-336766

Registered Utility Model No. 2576553 JP-A-8-39454

  According to the configuration of FIG. 5, since the expansion chamber 10 is provided on the upper side surface and the outer periphery of the nailing machine, there is a problem that the upper outer diameter of the nailing machine increases and the cornering performance deteriorates. Also, if the compressed air passage area of the throttle valve is made extremely small, or the passage resistance of the porous material of the muffler is made extremely large, it will take time to exhaust, making it impossible to drive continuously, or freezing due to adiabatic expansion of the compressed air. This could cause clogging and make it unusable.

  According to the configuration of FIG. 6, since the expansion chamber 10 and the muffler are provided in the top cover 42, securing a sufficient expansion chamber volume and muffler volume increases the height of the nailer and does not enter a narrow space. There was a problem. Further, as in FIG. 5, if the passage resistance of the muffler is extremely increased, exhaust time may be required, and continuous driving may not be possible, or it may become frozen due to adiabatic expansion of compressed air and become unusable due to clogging. . Further, since the compressed air in the head valve chamber 19 and the valve piston lower chamber 20 is exhausted while the pressure is high, there is a problem that it is uncomfortable.

  According to the configuration of FIG. 7, since there is an air passage 43 in the trigger valve 3 part of the handle 18, the compressed air in the handle 18 part of the pressure accumulating chamber is squeezed so that it does not flow easily to the body part of the pressure accumulating chamber. There was a problem of not coming out. Further, since the exhaust is at the end of the handle, if a sufficient expansion chamber volume and muffler volume are ensured, there is a problem that the length of the nailer becomes long and handling becomes worse. Further, as in FIG. 5, when the passage resistance of the muffler is extremely increased, it takes time for exhaustion, and it is impossible to continuously drive in, or it may become clogged due to freezing due to adiabatic expansion of compressed air, and may become unusable. .

  An object of the present invention is to eliminate the above-described problems of the prior art, to optimize the configuration of the expansion chamber and the throttle valve, and to provide a lightweight and compact nailing machine.

To achieve the above object, the present invention relates to a cylindrical cylinder, a piston slidably provided in the cylinder, a driver blade formed integrally with the piston, and a peripheral wall of the cylinder. In the air nailing machine, the expansion chamber is provided with a handle formed so as to extend substantially vertically and an expansion chamber provided in an exhaust passage communicating with the atmosphere on the upper side of the piston in the cylinder. Is composed of first and second expansion chambers extending substantially perpendicular to the peripheral wall of the cylinder, and a partition wall partitioning the first and second expansion chambers. The expansion chamber is formed so as to communicate with the longitudinal direction of the handle, the partition wall is provided with a first throttle hole, and the partition wall and the discharge port are provided with a second throttle hole, The area of the second throttle hole is set to be equal to that of the first throttle hole. It has one of the features that have less than the product.

  According to the present invention, the exhaust gas is discharged from the rear end of the handle through the exhaust expansion chamber formed in the longitudinal direction of the handle, so that the upper outer diameter and height of the nailing machine can be reduced, and the pressure accumulation chamber is restricted. Since there is no location, the compressed air in the pressure accumulating chamber can be used efficiently. Further, since the compressed air in the head valve chamber and the valve piston lower chamber is discharged to the expansion chamber, the exhaust pressure and volume can be reduced.

  The expansion chamber is divided into at least two, and a throttle hole is provided between the expansion chambers and after the subsequent expansion chamber, and the exhaust pressure is gradually reduced by gradually reducing the area of the throttle hole toward the discharge port. As a result, exhausting time is not required, and continuous driving cannot be performed, or freezing due to adiabatic expansion of the compressed air causes clogging, and it becomes impossible to use.

  The best mode for carrying out the present invention will be described in detail below.

  1 to 4 show an embodiment of the nail driver 1 of the present invention, and the overall configuration will be described based on this embodiment.

  Compressed air from a compressor (not shown) passes through outer peripheries of an air hose, an air plug 51, an air pipe 2, and a trigger valve 3 (not shown) and is accumulated in the pressure accumulating chamber 4. A cylindrical cylinder 5 is provided in the main body of the nail driver 1, and a piston 7 in which a driver blade 6 for driving a nail is integrated is provided in the cylinder 5 so as to be slidable up and down. The pressure accumulating chamber 4 is provided around the upper half of the cylinder 5. A head valve 8 is provided on the upper side of the cylinder 5. When the head valve 8 is raised, the upper end of the cylinder 5 is opened and the exhaust valve 9 is closed. The pressure accumulating chamber 4 and the upper side of the piston 7 in the cylinder 5 communicate with each other. The lower end of the cylinder 5 closes and the exhaust valve 9 opens, and the upper side of the piston 7 in the cylinder 5 communicates with the atmosphere through the expansion chamber 10 constituting the present invention. A return air chamber 11 for storing compressed air for returning the piston 7 to the top dead center is provided on the lower outer periphery of the cylinder 5. As is well known, the return air chamber 11 is located at a position where it passes during the reciprocating stroke of the piston 7. The cylinder 5 communicates with the inside of the cylinder 5 through a large number of holes 13 and a check valve 12. A number of holes 14 for returning the compressed air in the return air chamber 11 into the cylinder 5 are provided at the lower end of the cylinder 5. Furthermore, a piston bumper 15 is provided at the lower end of the cylinder 5 to absorb the surplus energy of the piston 7 after nail driving. The piston bumper 15 is made of a flexible material such as rubber and transforms surplus energy into heat and sound by being deformed.

  The exhaust cover 16 that houses the head valve 8 is provided with an air passage 17 that connects the exhaust valve 9 and the handle 18. Almost the entire interior of the handle 18 is formed to constitute the expansion chamber 10. That is, the expansion chamber 10 is constituted by an inner space of a substantially cylindrical handle cap 50 attached to a rear end of the handle 18 by means such as a screw (not shown) and an inner space excluding the air pipe 2 of the handle 18.

  A partition wall 22 is provided in the vicinity of the trigger valve 3 of the handle 18, and a throttle hole 22 a is provided in the approximate center of the partition wall 22. The expansion chamber 10 is divided into a first expansion chamber 21 and a second expansion chamber 23 by the partition wall 22. The second expansion chamber 23 communicates with the atmosphere through a hole 52 provided in the longitudinal direction of the handle cap 50, a throttle hole 53 provided in the flange of the handle cap 50, and a muffler 31 provided in the exhaust string 30. Yes. The exhaust string 30 is rotatably supported between the handle 18 and the handle cap 50, and the exhaust direction can be arbitrarily changed by rotating. A click mechanism 39 is provided at the rotating portion of the exhaust string 30 and the handle cap 50 so as to prevent the exhaust string 30 from rotating freely by the exhaust pressure. The area of the throttle hole 53 is set smaller than the area of the throttle hole 22a. As described above, the expansion chamber 10 includes the first expansion chamber 21, the throttle hole 22a, the second expansion chamber 23, the throttle hole 53, and the like, and repeatedly reduces the pressure by repeatedly limiting the expansion and the flow rate of the compressed air. ing. In addition, the pressure is gradually reduced and the flow rate is restricted due to the area difference between the throttle holes 22a and 53.

  The upper end of the trigger valve 3 communicates with the expansion chamber 10, that is, the first expansion chamber 21, and the compressed air in the head valve chamber 19 flows into the outer periphery of the valve piston 26 through the air passage 25, and causes the exhaust valve 27 of the valve piston 26 to flow. Through the first expansion chamber 21. The compressed air in the valve piston lower chamber 20 in the trigger valve 3 flows into the first expansion chamber 21 through the exhaust valve 29 of the plunger 28.

  Next, the operation of the nailing machine 1 configured as described above will be described with reference to FIGS.

  FIG. 1 shows a state where compressed air is stored in the pressure accumulating chamber 4. The compressed air flows into the head valve chamber 19 through a passage (not shown) of the air pipe 2 and the trigger valve 3 and also flows into the valve piston lower chamber 20 through the air passage 31 in the trigger valve 3.

  The head valve 8 blocks the pressure accumulating chamber 4 and the cylinder 5, and the upper side of the piston 7 of the cylinder 5 communicates with the atmosphere via the air passage 17 and the expansion chamber 10. The piston 7 is located at the top dead center.

  Next, FIG. 2 shows a state where the trigger 33 and the push lever 34 are operated and the plunger 28 of the trigger valve 3 is pushed up. The valve piston lower chamber 20 is blocked from the pressure accumulating chamber 4 and communicates with the first expansion chamber 21, and the compressed air in the valve piston lower chamber 20 is exhausted to the first expansion chamber 21. The exhaust is depressurized through the throttle hole 22a, the second expansion chamber 23, and the throttle hole 53, passes through the muffler 31, is further depressurized, rectified, reduced in sound, and discharged to the atmosphere.

  FIG. 3 shows a state where the compressed air in the valve piston lower chamber 20 is discharged and the valve piston 26 is lowered. When the valve piston lower chamber 20 becomes almost atmospheric pressure by the operation of FIG. 2, the valve piston 26 is lowered by the pressure difference between φA and φB. When the valve piston 26 descends, the air passage 25 and the pressure accumulating chamber 4 are blocked and the air passage 25 and the expansion chamber 10 communicate with each other. The compressed air in the head valve chamber 19 is exhausted to the first expansion chamber 21. The The compressed air in the head valve chamber 19 is depressurized in the throttle hole 22a, the second expansion chamber 23, and the throttle hole 53 in the same manner as the compressed air in the valve piston lower chamber 20, passes through the muffler 31, and is further depressurized and rectified. Sounded and discharged into the atmosphere.

  FIG. 4 shows a state where the head valve 8 is raised. The head valve 8 rises rapidly, the compressed air in the pressure accumulating chamber 4 flows into the cylinder 5 and pushes down the piston 7, and the nail 35 is driven into the driven material such as wood or outer wall material at the tip of the driver blade 6. Excess energy after driving is transformed into heat or sound by deforming the piston bumper 15.

  The air below the piston 7 of the cylinder 5 is gradually compressed and flows into the return air chamber 11 through the hole 14 at the lower end of the cylinder 5. When the piston 7 descends and passes through the hole 13, the compressed air above the piston 7 of the cylinder 5 flows into the return air chamber 11.

  Next, when the trigger 33 or the push lever 34 is released, the initial state shown in FIG. 1 is restored. The plunger 28 of the trigger valve 3 is lowered by the pressure difference between φC and φD and the pressing force of the plunger spring 36. The valve piston lower chamber 20 and the expansion chamber 10 are blocked, and the valve piston lower chamber 20 and the pressure accumulation chamber 4 communicate with each other. The compressed air in the pressure accumulating chamber 4 flows into the valve piston lower chamber 20. The compressed air flowing into the valve piston lower chamber 20 causes a pressure difference of φE and φF, and the valve piston 26 rises together with the pressing force of the plunger spring 36.

  When the valve piston 26 rises, the air passage 25 and the expansion chamber 10 are blocked, the air passage 25 and the pressure accumulation chamber 4 communicate with each other, and the compressed air in the pressure accumulation chamber 4 flows into the head valve chamber 19. A pressure difference of φG and φH is generated by the compressed air flowing into the head valve chamber 19, and the head valve 8 is lowered with the pressing force of the head valve spring 37.

  When the head valve 8 is lowered, the exhaust valve 9 is opened, and the compressed air on the upper side of the piston 7 of the cylinder 5 is the air passage 25 and the excess compressed air after returning the piston 7 of the return air chamber 11 to the top dead center is the upper end of the cylinder 5. The air flows into the first expansion chamber 21 through the air passage 38 and the air passage 25. The compressed air passes through the throttle hole 22a, the second expansion chamber 23, and the throttle hole 53 in order and is reduced in pressure, flows into the exhaust string 30, passes through the muffler 31, is further reduced in pressure, rectified and reduced in sound, and discharged to the atmosphere. Is done.

  In the above-described embodiment, the pressure accumulating chamber 4 is provided around the upper half of the cylinder 5, and the compressed air is supplied by the air pipe 2 through the trigger valve 3. For this reason, unlike conventional air nailers, compressed air is smoothly supplied without a constricted portion like a root of the handle, and the compressed air in the pressure accumulating chamber 4 is efficiently supplied into the cylinder 5. Will be introduced. As a result, the compressed air in the pressure accumulating chamber 4 can immediately flow into the cylinder 5 and the striking force can be improved. In addition, compressed air is supplied into the pressure accumulating chamber 4 from the rear end of the handle in the same manner as in a normal nailer, and the form of the hose does not change, so that the operability is not lowered.

  In the above-described embodiment, the expansion chamber 10 is divided into the two expansion chambers 21 and 23 and the two throttle holes 22a and 53 are provided. However, the number of these can be arbitrarily set.

The partial cross section side view which shows one Embodiment of this invention nailing machine. The partial cross section side view which shows the state which pushed up the plunger from FIG. FIG. 3 is a partial cross-sectional side view showing a state where the valve piston is lowered from FIG. 2. The partial cross section side view which shows the state which the piston fell to the bottom dead center from FIG. The partial cross section side view which shows an example of the conventional nailing machine. The partial cross section side view which shows the other example of the conventional nailing machine. The partial cross section side view which shows another example of the conventional nailing machine. The partial cross section side view which shows an example of the conventional air tool.

Explanation of symbols

1 is a nailing machine, 3 is a trigger valve, 10 is an expansion chamber, 18 is a handle, 21 is a first expansion chamber, 22a and 53 are throttle holes, 23 is a second expansion chamber, 30 is an exhaust string, 31 is a muffler is there.

Claims (3)

A cylindrical cylinder, a piston slidably provided in the cylinder, a driver blade formed integrally with the piston, and formed so as to extend substantially perpendicular to the peripheral wall of the cylinder. And an expansion chamber provided in an exhaust passage communicating with the atmosphere above the piston in the cylinder, the expansion chamber is substantially perpendicular to the peripheral wall of the cylinder. The first and second expansion chambers that extend and a partition wall that partitions the first and second expansion chambers, and the first and second expansion chambers communicate with each other in the longitudinal direction of the handle. The first restrictor hole is provided in the partition wall, the second restrictor hole is provided between the partition wall and the discharge port, and the area of the second restrictor hole is set to the first restrictor hole. An empty space that is smaller than the area of the aperture hole Nailing machine. In Claim 1, The said 1st throttle hole is provided in the partition wall between the said 1st expansion chamber and the 2nd expansion chamber so that compressed air may distribute | circulate to the longitudinal direction of the said handle | steering-wheel. Air nailer characterized by that. In Claim 1, The said 2nd throttle hole is provided between the said partition wall and the said exhaust port, and it is provided so that compressed air may be distribute | circulated in the direction parallel to the longitudinal direction of the said handle | steering_wheel. Air nailer to do.

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