JP5067095B2 - Gas fired driving tool - Google Patents

Description

  The present invention relates to an improved structure of a combustion chamber of a gas combustion type driving tool.

  In general, as shown in Patent Document 1, a gas combustion type driving tool is provided inside a tool body with a striking cylinder and a cylindrical movable sleeve that can be opened and closed, and the movable sleeve is closed to form a combustion chamber. When the is in a sealed state, flammable gas and fresh air are supplied to the inside, and after the flammable gas and air are stirred and mixed by the rotation of the fan, the mixed gas is ignited and explosively burned. The gas pressure is applied to the striking piston to drive the fastener, and after the driving is completed, the combustion chamber is opened to exhaust the combustion gas to prepare for the next driving operation.

The movable sleeve is arranged at the upper part of the impact cylinder, and has a structure for opening and closing the combustion chamber by moving the movable sleeve up and down. That is, as shown in Patent Document 1, when the movable sleeve moves upward, the movable sleeve is provided on the outer peripheral surface of the cylinder head portion provided above the striking cylinder and the outer peripheral surface of the upper end of the striking cylinder, respectively. The combustion chamber is sealed by contacting the upper seal portion and the lower seal portion, and when the movable sleeve moves downward, the seal with the upper and lower seal portions is removed and the combustion chamber is opened. Yes.
Japanese Examined Patent Publication No. 4-48589

  However, since the size of the movable sleeve in the radial direction is larger than that of the striking cylinder, it protrudes forward and backward and to the left and right accordingly. For this reason, it was not suitable for the operation of driving the fastener in a narrow space, such as when driving the fastener near the wall.

  The present invention eliminates the above-mentioned problems, and provides a gas combustion type driving tool excellent in operability when cornering in a narrow place while maintaining a basic arrangement structure and a predetermined volume in a combustion chamber. The issue is to provide.

  That is, in order to solve the above-mentioned problem, the invention according to claim 1 provides a cylinder head portion above a striking cylinder that slidably accommodates a striking piston, and has a cylindrical shape between the striking cylinder and the cylinder head portion. A gas combustion type in which a combustion chamber formed inside the movable sleeve is opened and closed by the operation of the movable sleeve, the mixed gas is ignited and burned in a sealed state, and exhaust and intake are made in an open state In the driving tool, the movable sleeve is disposed at a biased position behind the hitting cylinder.

  According to the first aspect of the present invention, since the movable sleeve is arranged at a position biased rearward of the striking cylinder, instead of reducing the degree of protrusion of the movable sleeve forward, it protrudes larger rearward or protrudes left and right. Instead of reducing the degree, the rearwardly projecting more greatly maintains the basic arrangement structure of the movable sleeve, ensures the radial size of the movable sleeve, and the degree to which the movable sleeve projects forward or left and right. Can be small. Therefore, since a margin can be obtained for driving the fastener in a narrow place, it is excellent in workability and operability when cornering. In addition, since the volume of the combustion chamber does not become small, the combustion energy does not change and a sufficient driving ability can be exhibited.

  The gas burning type driving tool according to the present invention will be described below with reference to a nailing machine.

  1 and 2, reference numeral 1 denotes a tool body of a gas combustion type driving tool (nailing machine). A grip 2 and a magazine 3 are connected to the tool body 1, and a combustion chamber 4 and a striking piston / cylinder mechanism are provided inside. A nose portion 5 for driving out a nail is provided below the tool body 1. In addition, a storage portion 7 for a fuel gas gas container 6 is provided at the rear of the tool body 1.

  The striking piston / cylinder mechanism is configured such that a striking piston 9 is slidably accommodated in a striking cylinder 8 and a driver 10 is integrally coupled below the striking piston 9.

  By the way, a cylindrical partition wall 11 is provided on the upper extension of the striking cylinder 8, and the upper end of the partition wall 11 is butt-coupled to the lower surface of the cylinder head 12 at the top of the tool body 1. Openings 13 and 14 are formed in the upper and lower portions of the partition wall 11, respectively.

  The cylinder head 12 is provided with a jet nozzle 15, a spark plug 16, and a rotary fan 17 that are connected to the gas container 6 and blow out fuel gas. The spark plug 16 is for igniting and burning the mixed gas of gas fuel and air in the combustion chamber 4, and the rotary fan 17 is for stirring and mixing the gas fuel and air. The rotary fan 17 is disposed at the center of the partition wall 11 so that the gap between the tip of the rotary fan 17 and the partition wall 11 is small, and the rotary fan 17 is positioned at the upper opening 13 of the partition wall 11. It is arranged between the lower opening 14. Reference numeral 18 denotes a motor for driving the rotary fan 17.

  Further, a movable sleeve 20 constituting the combustion chamber 4 is disposed on the upper part of the impact cylinder 8. The movable sleeve 20 is formed in a cylindrical shape, and is disposed between the striking cylinder 8 and the cylinder head portion 12 so as to be slidable in the vertical direction. The combustion chamber 4 configured inside the movable sleeve 20 is opened when it moves down as shown in FIG. 1, and the combustion chamber sealed inside the movable sleeve 20 when it moves up as shown in FIG. 4 is formed.

  That is, the peripheral edge of the cylinder head portion 12 is formed in a circular shape, and the upper O-ring 21 is provided on the outer peripheral edge. Further, an eccentric annular sliding portion 22 is formed on the outer peripheral portion of the upper end of the striking cylinder 8, and an opening groove 19 is scraped off at a predetermined interval below the annular sliding portion 22.

  The movable sleeve 20 is a cylindrical member and is formed with a larger diameter than the striking cylinder 8, and the movable sleeve 20 is disposed at a biased position biased rearward from the striking cylinder 8. In other words, the movable sleeve 20 is disposed so as to protrude more rearward instead of reducing the degree of forward protrusion.

  The upper and lower portions of the movable sleeve 20 are formed with small diameter portions 23 and 25 that are coaxial with the annular sliding portion 22, and the upper end of the upper small diameter portion 23 is formed with a protrusion 24 at a certain interval. Yes. There is a space between the adjacent protrusions 24. A lower O-ring 26 is provided around the inner periphery of the lower small-diameter portion 25.

  The inner surface of the upper small-diameter portion of the movable sleeve 20 is slidably disposed on the upper O-ring 21 on the end surface of the cylinder head portion 12, and the lower O-ring 26 of the lower small-diameter portion of the movable sleeve 20 is The annular sliding portion 22 is slidably disposed on the outer surface.

  With the above configuration, when the movable sleeve 20 moves up as shown in FIG. 1, the combustion chamber 4 is sealed by the upper O-ring 21 and the lower O-ring 26 to be in a sealed state. On the other hand, when it moves downward as shown in FIG. 2, the seal by the upper O-ring 21 of the cylinder head portion 12 is released, and the upper portion of the combustion chamber 4 is opened to the outside through the space between the protrusions 24. Similarly, the seal of the lower O-ring 26 of the movable sleeve 20 is also released, and the lower portion of the combustion chamber 4 is opened to the outside through the opening groove 19 of the annular sliding portion 22 of the striking cylinder 8.

  Further, the partition wall portion 11 constitutes a central combustion chamber 4 a and a combustion chamber 4 b outside the partition wall portion 11.

  The movable sleeve 20 is connected to a contact member 27 slidably provided at the tip of the nose portion 5 via a link member (not shown). The contact member 27 is biased by a spring so as to protrude from the tip of the nose portion 5. Therefore, when the nose portion 5 is pressed against the driven material, the contact member 27 is pushed up and moved up as shown in FIG. 1, so that the movable sleeve 20 is also moved up via the link member and sealed as shown in FIG. The combustion chamber 4 is configured. On the contrary, when the nose portion 5 is separated from the driven material, as shown in FIG. 2, the contact member 27 moves to the original position, so that the movable sleeve 20 also moves downward and the combustion chamber 4 is opened. It is.

  Next, the operation mode of the nailing machine having the above configuration will be described. First, when the nail is driven, when the nose portion 5 is strongly pressed against the workpiece and moved upward relative to the tool body 1, the movable sleeve 20 moves upward together with the contact member 27 in conjunction with this. 1, a sealed combustion chamber 4 is formed by an upper O-ring 21 provided in the cylinder head portion 12 and a lower O-ring 26 provided on the outer periphery of the upper end of the impact cylinder 8. After combustible gas is injected from the injection nozzle into the combustion chamber 4 and the rotating fan 17 is rotated by a motor to mix the combustible gas and air with stirring, the trigger 29 is pulled and the spark plug 16 ignites the mixed gas. And burn it explosively. Thereby, the striking piston 9 is driven, and the nail supplied into the nose portion 5 is driven out.

  On the other hand, after the driving is completed, the striking piston 9 is restored, and the contact arm is moved away from the driven material to move the movable sleeve 20 downward as shown in FIG. And the seal by the lower O-ring 26 is released, the combustion chamber 4 is opened, fresh air enters from the upper opening groove, combustion gas is exhausted from the lower opening groove, and the next driving is prepared.

  As described above, since the center of the movable sleeve 20 is arranged at a position biased rearward of the center of the striking cylinder 8, the movable sleeve 20 can be made movable by projecting it largely backward instead of reducing the degree of projection forward. The basic arrangement structure of the sleeve 20 can be maintained, the size of the movable sleeve 20 can be secured, and the degree to which the movable sleeve 20 protrudes forward can be reduced. Therefore, since the nail can be driven with a margin even at the wall 28 as shown in FIG. 1 or in a narrow place, workability and operability such as cornering are good. Further, since the volume of the combustion chamber 4 does not change, it is possible to sufficiently secure the combustion energy necessary for driving the nail.

  In addition, since the cylindrical partition wall 11 is provided on the extension of the upper end of the impact cylinder 8 and the openings 13 and 14 are formed in the upper and lower portions of the partition wall 11, respectively, the combustion chamber 4 has a combustion chamber inside. 4 through the lower opening 14 from the central portion 4a to the lower portion of the combustion chamber 4b outside the partition wall 11, further from the lower portion to the upper portion of the outer combustion chamber 4b, and from the upper portion of the outer combustion chamber 4b A flow path that passes through to the center of the combustion chamber 4 is formed as shown by an arrow. For this reason, when the gas fuel and air supplied into the combustion chamber 4 are mixed and stirred by the rotary fan 17 at the center of the combustion chamber 4, the mixed gas flows smoothly without staying along the flow path. Therefore, the efficiency of stirring and mixing is high, and therefore, the mixed gas can be reliably burned.

  In the embodiment, it has been described that the combustion chamber 4 is opened and closed by moving the movable sleeve 20 up and down. However, for example, the movable sleeve is rotated to rotate between the combustion chamber and the movable sleeve. Also good. In addition, the cylindrical partition wall 11 is provided on the extension of the upper end of the impact cylinder 8, but the impact cylinder 8 and the cylinder head 12 are fixed to the housing side of the tool body 1 and the partition wall 11 is not provided. A configuration is also possible.

  Further, the means for mixing the gas fuel and the air is not limited to the fan 17.

  Further, as shown in FIGS. 3 and 4, the basic arrangement structure of the movable sleeve 20 is maintained by projecting it more forward rather than reducing the degree of projecting to the left and right. In addition, it is possible to reduce the degree to which the movable sleeve 20 protrudes to the left and right. In this case, a margin is also obtained for driving the fasteners in the left and right narrow places, so that the operability at the time of cornering is excellent. Further, since the grip position is close to the striking cylinder position, operational stability is improved. 3 and 4 indicate the same members as those in FIGS. 1 and 2.

1 is a longitudinal sectional view showing a main part of a gas combustion type nailing machine according to an embodiment of the present invention, and is a longitudinal sectional view showing a state where a combustion chamber is sealed. Longitudinal section of the nailing machine showing the combustion chamber open when nailing It is a longitudinal cross-sectional view which shows the principal part of the gas combustion type nailing machine of other embodiment, and is a longitudinal cross-sectional view of the state in which the combustion chamber is sealed Longitudinal section of the nailing machine showing the combustion chamber open when nailing

A Gas combustion type driving tool 4 Combustion chamber 4
8 Stroke cylinder 9 Stroke piston 20 Movable sleeve

Claims (1)

A combustion chamber formed inside the movable sleeve by providing a cylinder head above the striking cylinder that slidably accommodates the striking piston, and disposing a cylindrical movable sleeve between the striking cylinder and the cylinder head portion. In the gas combustion type driving tool in which the mixed gas is ignited and burned in the sealed state and exhausted and sucked in the open state,
A gas combustion type driving tool characterized in that the movable sleeve is arranged at a biased position behind the hitting cylinder.

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