JP5045367B2 - Gas fired driving tool - Google Patents

Description

  The present invention relates to an improvement of a gas combustion type driving tool for supplying gas fuel from a gas can mounted in a tool body to a combustion chamber.

  Generally, a gas combustion type driving tool is provided with a gas pipe line between a gas can and a combustion chamber, and at the time of striking, a certain amount of gas fuel filled in the gas can is ejected with the combustion chamber sealed. The mixture gas supplied from the pipe line and mixed with air is ignited with a spark plug and burned explosively, and the combustion piston drives the impact piston in the impact cylinder and integrates with the impact piston. A fastener is driven out from a nose portion provided at the lower portion of the tool body by a combined driver.

  A metering chamber for storing a certain amount of gas fuel is disposed in the vicinity of the gas fuel jet outlet of the gas can, and an injection valve is provided at the outlet of the metering chamber. Normally, the gas ejected from the gas can is stored in the measuring chamber, and the gas fuel ejection port is blocked by the injection valve. At the time of striking, it is configured to send gas fuel in the measuring chamber from the gas conduit to the combustion chamber by opening the gas conduit by the injection valve in conjunction with the operation of the trigger (blocking the gas can). At the same time, the injection valve shuts off the gas can and the metering chamber so that the gas fuel in the gas can is not supplied to the metering chamber (see Patent Document 1).

By the way, the gas can used has a double structure in order to inject the gas fuel to the end, in order to compress the inner container between the inner container and the outer container containing the gas fuel. It is filled with propellant gas that is higher in pressure than gas fuel. In this structure, the pressure of the propellant gas is applied until the injection valve is closed. When the injection valve shuts off between the metering chamber and the gas can as described above during fuel injection, the propellant gas The pressure does not act and is supplied from the measuring chamber to the combustion chamber only by the vaporization pressure of the gas fuel.
No. 1-334753

  However, when used in a low temperature environment or the like, if the vaporization pressure of the gas fuel decreases, it takes time to flow from the measuring chamber into the combustion chamber or remains in the measuring chamber. Moreover, if the diameter of the gas pipe line between the gas can and the combustion chamber is small, the area where the gas fuel comes into contact with the air is small, so that it takes time to vaporize. Since the gas fuel is vaporized only from the portion of the gas pipe that is in contact with the most advanced air, if the gas pipe is thin, the area in contact with the air is small and vaporization takes time. For this reason, it takes time from when the valve is opened until the vaporized gas is sent into the combustion chamber and ignition is possible, and this causes deterioration in workability.

  The present invention solves the above-mentioned problems, and can supply gas fuel to the combustion chamber stably and reliably by applying pressure to the gas fuel even after the gas fuel injection pipe to the combustion chamber is opened. At the same time, it is an object of the present invention to provide a gas combustion type driving tool capable of shortening the vaporization time and shortening the time from the injection operation to ignition.

In order to solve the above-mentioned problem, the invention according to claim 1 is a gas for supplying a gas fuel from a gas can to a combustion chamber through a gas line and igniting, and driving a striking mechanism by this combustion pressure to eject a fastener. In the combustion type driving tool, a fuel supply valve is provided at an end portion on the combustion chamber side of the gas pipe, and the gas fuel supplied from the gas pipe is placed between a valve stem of the fuel supply valve and a valve cylinder. A metering chamber that can be filled in a fixed amount is formed, and the metering chamber is provided to be selectively openable in the gas pipe or combustion chamber in conjunction with the movement of the valve stem, and the valve stem is moved when the fastener is hit. Thus, the measuring chamber is directly opened to the combustion chamber.

According to the first aspect of the present invention, a certain amount of gas fuel from the gas pipe can be filled between the valve stem of the fuel supply valve provided at the end of the gas pipe on the combustion chamber side and the valve cylinder. A metering chamber is formed, and the metering chamber is provided so as to be selectively openable in the gas conduit or the combustion chamber in conjunction with the movement of the valve stem, and the metering chamber is moved by moving the valve stem when the fastener is hit. since the is configured to open to direct combustion chamber, the metering chamber is opened, the gas fuel in the metering chamber unit is immediately sent to the combustion chamber, the gas fuel regardless when working environment always stably and reliably combusted Can be supplied to the chamber. Even if the diameter of the gas pipeline is small or the vaporization pressure is low, the vaporization time is shortened, and the time from the injection operation to ignition can be shortened.

  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 1a and a magazine 1b are connected to the tool body 1, and a combustion chamber 2 and a striking piston / cylinder mechanism are provided inside. A nose portion 3 for driving out a nail is provided below the tool body 1.

  The striking piston / cylinder mechanism is configured such that a striking piston 5 is slidably accommodated in the striking cylinder 4 and a driver 6 is integrally coupled below the striking piston 5.

  The cylinder head portion 8 is provided with a spark plug 12 and a rotary fan 13. The spark plug 12 is for igniting and burning a mixed gas of gas fuel and air in the combustion chamber 2, and the rotary fan 13 is for stirring and mixing the gas fuel and air. The movable sleeve 15 is disposed at the center. Reference numeral 14 denotes a motor for driving the rotary fan 13.

  In the tool body 1, a storage portion 10 for a gas can 7 is formed behind the impact cylinder 4, and the gas can 7 filled with gas fuel is stored and held in the storage portion 10. The cylinder head portion 8 is opened with a gas conduit 11 for gas fuel that connects the gas can 7 and the combustion chamber 2. As described above, the gas can 7 has a double structure of an inner container containing liquefied gas fuel and an outer container filled with a propellant gas which is a few atmospheres higher than the inner pressure of the inner container. The inner container is pressed by the gas pressure of the propellant gas to eject gas fuel.

  Further, a movable sleeve 15 constituting the combustion chamber 2 is disposed on the outer upper portion of the striking cylinder 4. The movable sleeve 15 is formed in a cylindrical shape, and is disposed between the striking cylinder 4 and the cylinder head portion 8 formed in the upper housing 7 so as to be slidable in the vertical direction. The combustion chamber 2 configured inside the movable sleeve 15 is opened when it moves downward as shown in FIG. 1, and the combustion chamber sealed inside the movable sleeve 15 when it moves upward as shown in FIG. 2 is formed.

  That is, the periphery of the cylinder head portion 8 is formed in a circular shape, and the upper O-ring 16 is provided on the outer periphery. In addition, an annular sliding portion 17 that is bulged and formed on the outer periphery of the intermediate portion of the striking cylinder 4 is formed.

  The movable sleeve 15 is a cylindrical member and has a larger diameter than the striking cylinder 4, and a lower end of the movable sleeve 15 extends downward from an upper opening end of the striking cylinder 4. Small diameter portions 20 and 21 are formed on the upper and lower portions of the movable sleeve 15, and protrusions 20 a are formed on the upper end of the upper small diameter portion 20 at a predetermined interval. An opening groove is formed between the adjacent protrusions 20a. A lower O-ring 18 is provided around the inner periphery of the lower small-diameter portion 21.

  The inner surface of the upper small diameter portion 20 of the movable sleeve 15 is slidably disposed on the upper O ring 16 on the end surface of the cylinder head portion 8, and the lower O ring 18 of the lower small diameter portion 21 of the movable sleeve 15 is hit. It is slidably disposed on the outer surface of the annular sliding portion 17 of the cylinder 4.

  With the above configuration, when the movable sleeve 15 moves downward as shown in FIG. 1, the sealing by the upper O-ring 16 of the cylinder head portion 8 is released, and the upper portion of the combustion chamber 2 is opened to the outside through the opening groove 23. Similarly, the seal of the lower O-ring 18 of the movable sleeve 15 is also released, and the upper and lower portions of the combustion chamber 2 are opened to the outside. On the other hand, when the movable sleeve 15 moves up as shown in FIG. 2, the combustion chamber 2 is sealed by the upper O-ring 16 and the lower O-ring 18 to be in a sealed state.

  The movable sleeve 15 is connected to a contact member 20 slidably provided at the tip of the nose portion 3 via a link member (not shown). The contact member 20 is spring-biased so as to protrude from the tip of the nose portion 3. Therefore, when the nose portion 3 is pressed against the material to be driven, the contact member 20 is pushed and moves upward, so that the movable sleeve 15 also moves upward via the link member, and the combustion chamber 2 sealed as shown in FIG. 2 is configured. Is done. On the contrary, when the nose portion 3 is separated from the workpiece, the contact member 20 moves to the original position, so that the movable sleeve 15 also moves downward and the combustion chamber 2 is opened.

  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 3 is pressed strongly against the workpiece and moved upward relative to the tool body 1, the movable sleeve 15 is moved upward together with the contact member 20 in conjunction with this. 2, a sealed combustion chamber 2 is formed by an upper O-ring 16 provided in the cylinder head portion 8 and a lower O-ring 18 provided on the outer periphery of the upper end of the impact cylinder 4. Gas fuel is injected from a fuel supply valve 22, which will be described later, provided in the gas pipe 11 into the combustion chamber 2, and the rotating fan 13 is rotated by the motor 14 to stir and mix the combustible gas and air. 21 is pulled and ignited by the spark plug 12 to explosively burn. Thereby, the striking piston 5 is driven and the nail supplied into the nose portion 3 is driven out.

  On the other hand, after the driving is completed, the striking piston 5 is restored, and the contact member 20 is moved away from the driven material to move the movable sleeve 15 downward as shown in FIG. 16 and the lower O-ring 18 are released, the combustion chamber 2 is opened, fresh air enters from the upper part, and the next driving is prepared.

  Incidentally, a fuel supply valve 22 is provided at the end of the gas pipe 11 on the combustion chamber side. As shown in FIG. 3, the fuel supply valve 22 has a valve stem 24 slidably provided in the valve cylinder 23, and the upper part of the valve stem 24 is located above the upper wall 25 of the valve cylinder 23. A projecting shaft portion 26 that can be projected and retracted is formed, and three stages of O-rings 27, 28, and 29 are provided around the lower portion of the valve stem 24. Between the valve cylinder 23 and the valve stem 24, a blocking portion 30 having a volume close to zero is formed between the upper first O-ring 27 and the second O-ring 28, and the second O-ring 28. A measuring chamber 31 having a predetermined volume is formed between the first O-ring 29 and the third O-ring 29. The valve stem 24 is always biased so as to move upward by a spring 32.

  A through hole 33 connected to the end of the gas pipe 11 is formed in the lower portion of the side wall of the valve cylinder 23. The through-hole 33 is configured to open to the measuring chamber 31 when the valve stem 24 is always in the upper position so that a certain amount of gas fuel from the gas pipe 11 can be charged. When the valve stem 24 moves downward, the through hole 33 is blocked by the blocking portion 30, but the measuring chamber 31 is opened to the combustion chamber. Thus, the measuring chamber 31 is provided in the gas pipe 11 or the combustion chamber 2 so as to be selectively open in conjunction with the movement of the valve stem 24.

  Next, as shown in FIGS. 1 and 2, the tool body is provided with one end 35 a of a swing link 35 whose center part swings around a shaft 34 provided in the tool body 1, and the contact member 20. And the other end 35b of the link 35 are engaged with the protruding shaft portion 26 of the valve stem 24 of the fuel supply valve 22, respectively.

  According to the above configuration, the valve stem 24 is normally located at the upper position in FIG. 3, and a predetermined volume of gas is filled into the measuring chamber 31 from the through hole 33 through the gas pipe 11 from the gas can 7. . When the nail is driven, the operating rod 36 moves relatively upward together with the contact member 20 by pressing the tool body 1 downward toward the driven material as shown in FIG. 2, the link 35 swings and the other end 35 b of the link 35 descends to move the valve stem 24 of the fuel supply valve 22 downward as shown in FIGS. 2 and 4. The chamber 31 moves downward and is opened to the combustion chamber 2. At this time, the through hole 33 is closed by the sealing portion 30 between the first O-ring 27 and the second O-ring 28. Thereby, the gas fuel in the measurement chamber 31 is supplied to the combustion chamber 2 by the vaporization pressure.

  When the nail driving operation is completed and the rear main body is lifted and separated from the driven material, the contact member 20 moves downward, so that the force that pushes down the protruding shaft portion 26 of the valve stem 24 is released, and the valve The stem 24 moves upward by the force of the spring 32. Thereby, the measuring chamber 31 communicates with the gas pipe 11 again, and the next nail driving is prepared.

  When the measuring chamber 31 is thus opened, the gas fuel inside the measuring chamber 31 is immediately sent to the combustion chamber 2, so that the gas fuel is always supplied to the combustion chamber 2 stably and reliably regardless of the working environment. Can do. Even if the diameter of the gas pipe 11 is small or the vaporization pressure is low, the vaporization time is shortened, and the time from the injection operation to ignition can be shortened.

The longitudinal cross-sectional view which shows the principal part of the gas combustion type nailer of embodiment which concerns on this invention Longitudinal sectional view of the gas fired nailer showing the combustion chamber sealed Cross section of fuel supply valve Operational explanatory diagram of the fuel supply valve

1 Tool Body 2 Combustion Chamber 11 Gas Pipe Line 22 Fuel Supply Valve 23 Valve Cylinder 24 Valve Stem 31 Measuring Chamber

Claims (1)

In the gas combustion type driving tool for supplying the gas fuel from the gas can to the combustion chamber from the gas pipe line and igniting, driving the impact mechanism with this combustion pressure and ejecting the fastener,
A fuel supply valve is provided at the end of the gas conduit on the combustion chamber side, and a certain amount of gas fuel supplied from the gas conduit can be filled between the valve stem of the fuel supply valve and the valve cylinder. A measuring chamber is formed, and the measuring chamber is provided in the gas pipe line or the combustion chamber so as to be selectively open in conjunction with the movement of the valve stem, and the measuring chamber is moved by moving the valve stem when the fastener is hit. A gas combustion type driving tool characterized by opening directly into a combustion chamber.

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