JP2010076060A - Combustion type nailing machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a combustion type nailing machine capable of reliably returning a piston to a top dead center by promoting the return of the piston after driving a nail. <P>SOLUTION: The combustion type nailing machine comprises a housing, a cylinder provided in the housing, a piston supported in the cylinder in a vertically movable manner, a combustion chamber provided above the cylinder, and an exhaust port formed in a side surface of the cylinder. A combustion gas inflow port and a passage for communicating the exhaust port with the combustion gas inflow port are formed in the side surface of the cylinder. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a combustion nailing machine.

  A conventional combustion nailing machine will be described. 4 and 5, a nail driver 1 is a combustion type nailer that drives a nail using gas as a fuel, and has a housing 2 as an outer shell. A cylinder 7 is fixed below the inside of the housing 2. An exhaust port 16 is provided on the side surface below the cylinder 7. The cylinder 7 accommodates the piston 8 integrated with the driver blade 9 so as to be movable up and down, and further forms a combustion chamber 20 in the upper part thereof. A push lever 6 is provided below the housing 2, and the fuel gas is supplied to the combustion chamber 20 from the gas cylinder 12 built in the housing 2 by pressing the push lever 6 against the material to be driven. Further, when the push lever 6 is pressed against the driven material to a predetermined position, a sensor (not shown) detects the motor 10 and the fan 11 rotates. Thereby, the air in the combustion chamber 20 and the fuel gas are mixed. By pulling the trigger 21, a spark is generated in the combustion chamber 20, and the mixed gas in the combustion chamber 20 burns and explodes to drive the piston 8 downward. Then, a driver blade 9 integrated with the piston 8 drives a nail.

  In the conventional combustion nailing machine described above, after the nail is driven, when the combustion gas is cooled by heat conduction on the inner wall of the cylinder, the pressure on the upper side of the piston becomes negative with respect to the outside air, and the atmospheric pressure on the lower side of the piston causes the piston to return to the initial state. Return to position. However, if the push lever is moved away from the material to be driven immediately after nail driving, the pressure on the upper side of the piston does not drop sufficiently due to the air flowing into the combustion chamber from the atmosphere, and the piston cannot be returned to the initial position. There was a thing.

In order to solve the above problems, a housing, a cylinder provided in the housing, a piston supported in the cylinder so as to be movable up and down, a combustion chamber provided above the cylinder, and a side surface of the cylinder In the combustion nailing machine provided with an exhaust port provided in the cylinder, a combustion gas inlet and a passage communicating the exhaust port and the combustion gas inlet are provided on a side surface of the cylinder.

  According to the present invention, the exhaust port provided on the side surface of the cylinder is provided with a passage connected from the upper side of the piston to the lower side of the piston so that the combustion exhausted from the exhaust port when the piston returns to the initial position. Gas is sent below the piston. Thereby, the combustion gas which flowed into the lower side of the piston helps the piston to return to the initial position, and can reliably return the piston to the initial position.

  A nailing machine according to the present invention will be described with reference to FIGS.

  The nailing machine 1 is a combustion type nailing machine in which nails are driven using gas as fuel, and has a housing 2 as an outer shell. The nailing machine 1 mainly includes a housing 2, a head 4, a handle 3, a magazine 13, a cylinder 7, a gas cylinder storage portion 12a, and an injection portion 14.

  The head 4 is provided in the upper part in the housing 2. The head 4 supports a motor 10 and a spark plug, and a fan 11 is attached to the rotating shaft of the motor 10. In the head 4, a fuel gas passage 24 that connects the gas cylinder nozzle 12 b and the combustion chamber 20 is formed. A head cover 27 is provided so as to cover the top of the head 4. The head cover 27 forms the upper end portion of the housing 2. The head 4 is provided with a head seal portion 4 a and has a structure for sealing with a combustion chamber frame 5 described later. A gas cylinder storage portion 12 a is provided on the side of the housing 2.

  A gas cylinder 12 that stores fuel gas and includes a gas cylinder nozzle 12b is stored in the gas cylinder storage portion 12a. The gas cylinder nozzle 12 b is provided so as to be selectively conductive to the fuel gas passage 24 of the head 4. When the push lever 6 positioned at the lower end of the nailing machine 1 is pressed against the driving material, the cam receiving the push-up force of the push lever 6 pushes the gas cylinder 12. Then, the gas cylinder 12 is inclined toward the housing 2, and the gas cylinder nozzle 12b is pushed by this inclination. As a result, the fuel gas is injected from the gas cylinder 12 into the combustion chamber 20 through the gas cylinder nozzle 12 b through the fuel gas passage 24. A handle 3 extends from the gas cylinder storage portion 12a.

  A trigger 21 is attached to the handle 3 so as to be operable with an operator's finger, and a spark switch 22 connected to a spark plug is provided in the handle 3. A detachable battery 23 is mounted on the free end portion side of the handle 3, and the battery 23 is connected to the spark switch 22 and the motor 10 through wiring.

  The lower end of the housing 2 is loaded with an injection portion 14 that forms a passage that allows the driver blade 9 to pass therethrough in order to transmit the power of the driver blade 9 to the nail, and a nail that is struck by the driver blade 9. In addition, a magazine 13 for supplying nails to the passage of the injection unit 14 is provided.

  The magazine 13 has one end connected to the injection portion 14 and the other end connected to the handle 3, and the handle 3 and the magazine 13 are fixed by a connecting member and have a strong structure. The magazine 13 is provided with a feeding member that urges the nail toward the injection portion 14. The feeding member urges the nail toward the injection unit 14 so that the nail is always supplied to the injection unit 14.

  A cylinder 7 is fixed to the lower part in the housing 2. A cylinder seal portion 7 a is formed on the outer peripheral surface on the upper end side of the cylinder 7. A piston 8 is provided in the cylinder 7 so as to be movable up and down. A driver blade 9 for driving a nail into the driven material extends from the piston 8 toward the lower end side of the housing 2.

  Further, an exhaust port 16 is provided on the side surface near the lower end of the cylinder 7 for exhausting combustion gas generated after driving the nail to the outside. The exhaust port 16 is provided with a check valve 17 that discharges combustion gas only in the direction from the cylinder 7 to the outside. The check valve 17 is covered with a cover 25, and a passage 18 is formed between the cover 25 and the side surface of the cylinder 7. The cover 25 is made of stainless steel and is a member formed by pressing. The check valve 17 and the upper end of the cover 25 are provided with holes for passing screws. Therefore, the check valve 17 and the cover 25 are screwed to the cylinder 7. On the side surface of the cylinder 7, a combustion gas inlet 26 is provided further below the exhaust port 16. The combustion gas inlet 26 is located below the position of the bottom dead center of the piston 8. The end of the cover 25 that is not screwed, that is, the lower end is in contact with the lower surface of the combustion gas inlet 26. Therefore, when the piston 8 is located at the bottom dead center, the upper side of the piston 8 is connected to the lower side of the piston 8 via the exhaust port 16, the passage 18, and the combustion gas inlet 26.

  In the housing 2, a combustion chamber frame 5 that is movable in the vertical direction is provided by being guided by a cylinder 7. Depending on the movement position of the combustion chamber frame 5, the inner peripheral surface is sealed by the head seal portion 4a and the cylinder seal portion 7a. When the combustion chamber frame 5 moves upward in the housing 2 and contacts the head 4, the combustion chamber 20 is formed by the head 4, the combustion chamber frame 5, and the piston 8. The spark plug and the open end of the fuel gas passage 24 face the combustion chamber 20. A fan 11 fixed to the rotating shaft of the motor 10 is disposed in the combustion chamber 20 so as to be rotatable by the motor 10. The fan 11 has a function of taking air into the combustion chamber 20 from an intake port (not shown) provided in the head cover 27, stirring the combustion gas and air, exhausting the combustion gas, and cooling the cylinder 7. ing.

  Next, the operation of the nailing machine of the present invention will be described. In FIG. 1, when the push lever 6 is not pressed against the material to be driven, the combustion chamber frame 5 is at the bottom dead center. At this time, the combustion chamber frame 5 is not sealed with the head seal portion 4a and the cylinder seal portion 7a, and the space in the combustion chamber frame 5 is connected to the outside air. The combustion chamber frame 5 is in contact with the cylinder seal portion 7 a at a portion formed in a rib shape of the combustion chamber frame 5. Therefore, the combustion chamber frame 5 is not sealed with the cylinder seal portion 7a.

  In FIG. 2, when the push lever 6 is pressed against the material to be driven, the combustion chamber frame 5 moves upward in conjunction with the movement of the push lever 6, and the combustion chamber frame 5 includes the head seal portion 4 a and A combustion chamber 20 is formed which is sealed from the outside air by the combustion chamber frame 5, the head 4, and the piston 8 by sealing with the cylinder seal portion 7a. Further, when the combustion chamber frame 5 rises to a predetermined position, a sensor (not shown) detects it, and drives the motor 10 to rotate the fan 11. When the push lever 6 is pressed against the material to be driven, the gas cylinder 12 tilts toward the housing 2 and the gas cylinder nozzle 12b is pressed, so that fuel gas is injected from the gas cylinder 12 into the combustion chamber 20 through the fuel gas passage 24. Is done. Thereby, the inside of the combustion chamber 20 is filled with a mixed gas of air and fuel gas.

  When the push lever 6 is pressed against the material to be driven and the trigger 21 is pulled in a state where the combustion chamber frame 5 is at the top dead center, that is, the combustion chamber 20 is formed, the spark switch 22 is turned on and the spark is discharged from the spark plug. appear. Since the tip of the spark plug faces the combustion chamber 20, the mixed gas is ignited in the combustion chamber 20, and the mixed gas burns and explodes to drive the piston 8 downward. Therefore, the driver blade 9 hits the nail in the injection portion 14, and the nail is driven into the driven material.

  When the mixed gas in the combustion chamber 20 burns and explodes, the volume expands, and the upper side of the piston 8 is in a high temperature / high pressure state. When the piston 8 descends and passes through the exhaust port 16, the combustion gas on the upper side of the piston 8 flows into the lower side of the piston 8 through the exhaust port 16 having a check valve, the passage 18, and the combustion gas inlet 26. Thereafter, the piston 8 descends and contacts the bumper 19.

  The combustion gas on the upper side of the piston 8 is hot immediately after combustion, but is then cooled by heat conduction on the inner wall of the cylinder 7. As a result, the upper side of the piston 8 is in a negative pressure state lower than the atmospheric pressure. When the upper side of the piston 8 is in a negative pressure state, the check valve 17 is closed, so that the combustion gas on the upper side of the piston 8 flows into the lower side of the piston 8 for a short time. Further, since there is a gap between the housing 2 and the injection portion 14, the lower side of the piston 8 eventually returns to atmospheric pressure.

  The piston 8 passes through the exhaust port 16, the passage 18, and the combustion gas inlet 26 at a short time until the atmospheric pressure below the piston 8 and the upper side of the piston 8 change from a high pressure state to a negative pressure state. It is pushed up by the force of the combustion gas flowing into the side. Therefore, when the upper side of the piston 8 becomes negative pressure, the piston 8 can surely return to the top dead center.

  Thereafter, when the trigger 21 is turned off, the main body is lifted, and the push lever 6 is separated from the material to be driven, the push lever 6 and the combustion chamber frame 5 return downward. When the combustion chamber frame 5 returns to the bottom dead center, the combustion chamber frame 5 does not seal with the cylinder seal portion 7a and the head seal portion 4a. Therefore, the space in the combustion chamber frame 5 is connected to the outside air. Further, the fan 11 is controlled to rotate for a predetermined time by a circuit (not shown) even after nailing. As a result, air is taken into a space in the combustion chamber frame 5 from an inlet (not shown) provided in the head cover 27 through a gap between the head seal portion 4 a and the combustion chamber frame 5. Further, the combustion gas remaining in the space in the combustion chamber frame 5 is discharged to the outside air from below the housing 2 through the gap between the combustion chamber frame 5 and the cylinder seal portion 7 a by the rotation of the fan 11. Further, the fan 11 rotates, and the air passes through the gap between the combustion chamber frame 5 and the cylinder seal portion 7a, and is exhausted through a passage formed by the inner wall of the housing 2 and the outer wall of the cylinder 7, whereby the cylinder 7 Is cooled.

  According to the present invention, a part of the combustion gas after driving the nail flows into the lower side of the piston 8 through the exhaust port 16, the passage 18 formed by the cover 25 and the side surface of the cylinder 7, and the combustion gas inlet 26. To do. The part of the combustion gas that has flowed in helps the piston 8 to return to the top dead center due to the pressure difference between the negative pressure on the upper side of the piston and the atmospheric pressure on the lower side of the piston. Thereby, even when the push lever 6 is quickly released from the driven material, the piston 8 can surely return to the top dead center.

  As mentioned above, although one Embodiment of this invention was described, various changes in the range which does not deviate from the content of invention are possible. For example, in the present invention, the passage 18 is formed by the cover 25 and the outer wall of the cylinder 7. However, the same effect can be obtained by forming the passage 18 by connecting the exhaust port 16 and the combustion gas inlet 26 with a pipe. .

Overall sectional view of the nailing machine of the present invention Sectional drawing of the state which pressed the push lever of the nailing machine of this invention Sectional drawing of the state which pressed the push lever of the nailing machine of this invention Cross-sectional view of a conventional nailer Cross-sectional view of a conventional nailer with the push lever pressed

Explanation of symbols

1: Nailer 2: Housing 3: Handle 4: Head 4a: Head seal portion 5: Combustion chamber frame 6: Push lever 7: Cylinder 7a: Cylinder seal portion 8: Piston 9: Driver blade 10: Motor 11: Fan 12 : Gas cylinder 12a: Gas cylinder storage part 12b: Gas cylinder nozzle 13: Magazine 14: Injection part 16: Exhaust port 17: Check valve 18: Passage 19: Bumper 20: Combustion chamber 21: Trigger 22: Spark switch 23: Battery 24: Fuel Gas passage 25: Cover 26: Combustion gas inlet 27: Head cover

Claims (2)

A housing, a cylinder provided in the housing, a piston supported in the cylinder so as to be movable up and down, a combustion chamber provided above the cylinder, and an exhaust port provided on a side surface of the cylinder; A combustion type nailing machine comprising: a combustion gas inlet and a passage communicating the exhaust port and the combustion gas inlet on a side surface of the cylinder. 2. The combustion type nailing according to claim 1, wherein the exhaust port is above the bottom dead center of the piston and the combustion gas inlet is below the bottom dead center of the piston. Machine.

Images