JP2006000956A - Combustion type working tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a combustion type working tool which is formed such that a combustion chamber wall forming combustion chambers is movable, wherein the combustion type working tool achieves rational and efficient power supply to ignition sections arranged on the combustion chamber wall. <P>SOLUTION: The combustion type working tool is formed of: the combustion chambers 121, 122; the combustion chamber wall 126 forming the combustion chambers, the ignition sections 133a, 133b each having an ignition region facing the combustion chamber; a power supply section 138 for supplying electric power to the ignition sections; a cylinder 153 connected to the combustion chambers; and a piston member 155 slidably housed in the cylinder. The combustion type working tool is comprised of energization control sections 134, 135 electrically connected to the power supply section and arranged so as to be spaced away from the ignition sections. The energization control sections allow the power supply section to energize the ignition sections when the energization control sections make contact with the ignition sections according to movement of the combustion chamber wall to a combustion performing location, whereas the energization control sections inhibit the power supply section from energizing the ignition sections when the combustion chamber wall is moved to a location other than the combustion performing location, by separating them away from the ignition sections. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an ignition technique for a work tool that performs a predetermined machining operation using a high pressure (impact force) when a combustible gas is burned, that is, a combustion type work tool.

  Regarding a so-called combustion type work tool, a specific example using a piston / cylinder type internal combustion engine as a drive source of a work tool such as a nailing machine or a tacker is disclosed in Japanese Patent Laid-Open No. 2003-260674 (Patent Document 1). Yes. In Patent Document 1, an operation switch is provided that is activated by pressing a contact arm disposed at a tip of a tool body against a workpiece, and the trigger is operated by operating a trigger in a state in which the operation switch is activated. A configuration is disclosed in which, when a switch is operated, power from a power supply unit is supplied to an ignition unit, thereby igniting combustible gas in a combustion chamber. As described above, conventionally, the power supply unit and the ignition unit are connected by a cord (wiring) intervening the operation switch operated by the contact arm and the trigger switch operated by the trigger, and the contact arm is processed. This is a configuration that enables ignition only when pressed against the material.

By the way, some combustion-type work tools have a configuration in which a combustion chamber wall constituting the combustion chamber is moved in order to introduce fresh air into the combustion chamber or to discharge exhaust gas after combustion. When the combustion chamber having such a configuration is provided, the ignition unit (ignition plug) disposed in the combustion chamber moves together with the combustion chamber wall. Therefore, in the configuration in which the power supply unit and the ignition unit are connected by wiring, a configuration in which a slack portion for allowing movement of the ignition unit is set in the wiring is necessary, and the slack portion of the wiring is accommodated on the housing side. However, there is still room for improvement in that it is necessary to secure a storage space for doing so.
Japanese Patent Laid-Open No. 2003-260674

  The present invention has been made in view of the above points, and contributes to rational power supply to the ignition unit arranged on the combustion chamber wall in the combustion type work tool configured to move the combustion chamber wall constituting the combustion chamber. The purpose is to provide technology.

In order to achieve the above object, the invention described in each of the claims is configured.
According to the first aspect of the present invention, a combustion chamber, a combustion chamber wall that constitutes the combustion chamber, an ignition unit having an ignition region facing the combustion chamber, a power supply unit that supplies power to the ignition unit, and a combustion A combustion type work tool having a cylinder connected to the chamber and a piston member slidably accommodated in the cylinder is configured. The combustion chamber wall is configured to move to introduce air into the combustion chamber or to discharge exhaust gas. The movement of the combustion chamber wall is typically disposed on the tip side of the tool body that accommodates the combustion chamber, and is always biased toward the tip side by the biasing means and pressed against the workpiece. By means of a contact arm which is moved backward relative to the tool body. When the combustion chamber wall is moved to a combustible position that allows combustion of the combustible gas in the combustion chamber, the combustible gas in the combustion chamber is burned by the ignition region of the ignition unit. The piston member is moved forward by the combustion pressure generated by the combustion action of this, thereby performing a predetermined machining operation. Typically, the “predetermined processing operation” corresponds to an operation for driving nails, staples, or the like into a workpiece. Further, the “combustible position” in the present invention typically corresponds to one end of the stroke in the movement stroke of the combustion chamber wall, but is not limited to the end of the stroke, and a position in the vicinity thereof is preferably used. Include.

In the combustion type work tool according to the present invention, as a characteristic configuration, an energization control unit that is provided on the tool body, is electrically connected to the power supply unit, and is spaced apart from the ignition unit. Have In the state where the combustion chamber wall is moved to the combustible position, the energization control unit allows the energization from the power supply unit to the ignition unit by contacting the ignition unit with the movement of the combustion chamber wall, and the combustion In a state where the chamber wall has moved to a position other than the combustible position, the energization from the power supply unit to the ignition unit is regulated by being separated from the ignition unit. Here, as a mode in which “the power supply unit is in contact with the ignition unit”, a mode in which a conductive piece connected to the electrode is set and a contact is made with this electrode as well as a mode in which the power supply unit directly contacts the electrode constituting the ignition region. Are also preferably included. In addition, “allowing energization” refers to a state where power can be supplied from the power supply unit to the ignition unit, and “regulating energization” refers to a state where power cannot be supplied. Say. The “power supply unit” typically corresponds to a piezoelectric element that generates high-voltage power by operating an ignition operation means (trigger).
According to the present invention, between the power supply unit and the ignition unit, an energization control unit that allows energization from the power supply unit to the ignition unit by contacting the ignition unit and regulates the energization by separating the power supply unit and the ignition unit. Since the configuration is such that the energization control unit ignites in a state of being in contact with the ignition unit, the ignition unit can be moved significantly without being restricted by the cord. Further, according to the present invention, energization of the ignition unit is permitted at a time when the combustible gas is filled in the combustion chamber and the combustible gas can be burned, and it is ensured at a time when ignition is required. Can be ignited.

(Invention of Claim 2)
According to the second aspect of the present invention, the energization control unit in the combustion type work tool according to the first aspect is movable in the same direction as the movement direction of the combustion chamber wall and is moved together with the combustion chamber wall. A movable member that is separated from or in contact with the igniting portion and an urging member that constantly urges the movable member toward the igniting portion, and each of the movable member and the urging member is formed of a conductive material. The configuration is The “movable member” preferably includes a ball made of metal or carbon material, a columnar member, a cylindrical member, or the like. The “biasing member” typically corresponds to a metal coil spring. According to the present invention, the movable member and the urging member formed of the conductive material can be operated to follow the moving operation of the ignition unit for a part of the moving region of the ignition unit. It is possible to stabilize the power feeding action by reducing the impact and to reduce the impact at the time of contact between the ignition part and the movable member.

(Invention of Claim 3)
According to the third aspect of the present invention, the combustion type work tool according to the first or second aspect is disposed on the distal end side of the tool main body that houses the combustion chamber, and is always biased toward the distal end side. And a contact arm that is moved backward relative to the tool body by being pressed against the workpiece, and an ignition operation means that operates ignition of the ignition unit. Then, the combustion chamber wall is moved to the combustible position by the retreating operation of the contact arm based on the pressing of the contact arm against the workpiece, and thereby the ignition operation by the ignition operation means in a state where the energization control unit is in contact with the ignition unit. Therefore, the power of the power supply unit is supplied to the ignition unit.
According to the above configuration, only when the contact arm is pressed against the workpiece and is retracted, the energization control unit contacts the ignition unit and can be energized. In other words, in a state where the contact arm is not pushed in, the ignition unit and the power supply unit are separated, and even if the ignition operation means is ignited, the supply of electric power can be regulated.

(Invention of Claim 4)
According to a fourth aspect of the present invention, in the combustion type work tool according to any one of the first to third aspects, the partition wall that partitions the combustion chamber into a first combustion chamber and a second combustion chamber is provided. The ignition portion is disposed in the first combustion chamber, and the partition wall is disposed on the spherical portion centering on the ignition portion, and the spherical portion, and communicates the first combustion chamber and the second combustion chamber. When the combustible gas in the first combustion chamber is combusted by the ignition unit, the combustion surface of the combustible gas in the first combustion chamber reaches the communication holes almost simultaneously. It is configured to Here, the “combustion surface” refers to a boundary surface between the burned portion and the unburned portion when the combustible gas burns, and typically corresponds to the “flame surface (flame surface)”. Note that the arrival timing of the combustion surface of the combustion gas does not need to be exactly the same in each communication hole, and the “spherical portion” of the partition wall is not only a mode in which the curvature at the corresponding portion of the partition wall is constant, An aspect with a slightly different curvature, that is, a spherical surface with an elliptical cross section is also preferably included. In other words, it is not necessary that the entire area of the spherical portion is exactly the same diameter around the ignition part. In addition, the partition wall may be spherical throughout, or only a part of the partition wall may be spherical.

  According to the present invention, since the partition wall is configured as a spherical part having a substantially equal diameter centered on the ignition part, the combustion surface of the air-fuel mixture emitted from the ignition part in the first combustion chamber is the ignition part. To the communication holes of the spherical portion having the same radius with respect to each other. For this reason, the combustible gas in the second combustion chamber is ignited uniformly and simultaneously from the peripheral region of the partition wall, thereby transferring the combustion energy in the second combustion chamber to the piston member side in a balanced manner. It is possible to do. In other words, the combustible gas in the second combustion chamber is less likely to vary in the timing of starting combustion through each communication hole of the partition wall, so that the combustion controllability in the second combustion chamber and thus the combustion efficiency are improved. It becomes possible.

  According to the present invention, in the combustion-type work tool configured to move the combustion chamber wall that constitutes the combustion chamber, a technique that contributes to rational power supply to the ignition unit disposed on the combustion chamber wall is provided. .

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
An overall configuration of a nailing machine 101 according to an embodiment of the present invention is shown in FIGS. 1 to 5, and a peripheral portion of a combustion chamber is shown as an enlarged view in FIGS. 8 is a cross-sectional view taken along the line IIX-IIX in FIG. The nailing machine 101 is an example of the “combustion-type work tool” in the present invention. As shown in FIGS. 1 to 5, the main housing 103, the injection unit 110, the hand grip 105, and the magazine 109 form an outer shell. Has been. The main housing 103, the injection unit 110, the hand grip 105, and the magazine 109 constitute a “tool body” in the present invention. In the main housing 103, a first combustion chamber 121, a second combustion chamber 122, an ignition device 131, a fuel injection device 141, and a drive unit 151 are accommodated. That is, the nailing machine 101 according to the present embodiment is configured to have a plurality of combustion chambers including the first combustion chamber 121 and the second combustion chamber 122. In the following description, the injection unit 110 side will be described as the front side (left side in FIGS. 1 to 5), and the opposite side (right side in FIGS. 1 to 5) as the rear side.

  In the present embodiment, the combustion chamber is partitioned into a first combustion chamber 121 and a second combustion chamber 122 in the major axis direction (that is, the major axis direction of the nail driver 101). The second combustion chamber 122 is configured to be used as a region for obtaining a large combustion energy necessary for the nail driving operation. The first combustion chamber 121 corresponds to the “first combustion chamber” in the present invention, and the second combustion chamber 122 corresponds to the “second combustion chamber” in the present invention.

  The first combustion chamber 121 includes a partition wall 123 having a circular outer shape for partitioning the first combustion chamber 121 from the second combustion chamber 122, and a substantially flat end located on the opposite side of the second combustion chamber 122. It is surrounded by a circular slide end plate 129 having a wall surface. That is, the partition wall portion 123 has a flat surface portion 123a on the outer peripheral side and a spherical portion 123b that bulges toward the second combustion chamber 122 side on the center side, and the flat surface portion 123a slides. The end plate 129 is fixed in close contact with the end wall surface. Said partition part 123 respond | corresponds to the "partition wall" in this invention. The spherical portion 123b of the partition wall portion 123 is formed in an approximately equal diameter and hemispherical shape with the ignition portion of the ignition device 131 as the center. A large number of communication holes 125 are formed in the spherical portion 123b of the partition wall portion 123 (see FIG. 8). The first combustion chamber 121 and the second combustion chamber 122 are in communication with each other through the communication hole 125. That is, the distance from the ignition unit to each communication hole 125 is set to be equal, and when the air-fuel mixture in the first combustion chamber 121 is ignited and burned by the ignition unit of the ignition device 131, the first The combustion surface (flame surface) in one combustion chamber 121 is configured to reach each communication hole 125 almost simultaneously. The ignition unit is composed of two electrodes 133a and 133b that are arranged to face each other with a predetermined gap therebetween. This will be described later.

  The second combustion chamber 122 is formed as a space surrounded by a piston 155 that constitutes a drive unit, a cylindrical slide sleeve 127, and a partition wall 123 that is disposed to face the piston 155. The piston 155 corresponds to the “piston member” in the present invention. The top surface of the piston 155 (the surface facing the partition wall 123) is a spherical recess 155a formed in a similar shape corresponding to the spherical portion 123b of the partition wall 123. The partition wall 123, the slide sleeve 127, and the slide end plate 129 are fastened and fixed to each other by a plurality of screws 128 arranged in the circumferential direction, and the cylindrical combustion chamber wall 126 whose front end is opened by these three members. Is configured. That is, the slide sleeve 127 constitutes the peripheral wall surface of the second combustion chamber 122, the partition wall portion 123 constitutes the end wall surface of the second combustion chamber 121 and the spherical wall surface of the first combustion chamber 121, and the slide end plate 129. Constitutes an end wall surface of the first combustion chamber 121. The combustion chamber wall 126 constitutes a “movable member”.

  The combustion chamber wall 126 is movable in the long axis direction (front-rear direction) of the nail driver 101 and is connected to the contact arm 111. The contact arm 111 is normally urged forward (forward) by a spring 112 as urging means, and the combustion chamber wall 126 is also moved forward. This state is the initial state of the nailing machine 101 shown in FIG. 1, and the volume of the second combustion chamber 122 has been reduced to zero or close to zero.

  On the other hand, when the nailing machine 101 is moved toward the workpiece W (see FIG. 2) and the contact arm 111 is pressed against the workpiece, the contact arm 111 pressed by the workpiece is moved by the spring 112. It is moved in the opposite direction against the biasing force. The backward movement of the contact arm 111 is transmitted to the slide sleeve 127. For this reason, the combustion chamber wall 126 is moved to the fixed end plate 175 side constituting the end wall surface of the atmospheric chamber 171 described later, and the end portion of the slide end plate 129 contacts the fixed end plate 175. This state is shown in FIG.

  As the combustion chamber wall 126 moves in the front-rear direction, the volume of the second combustion chamber 122 decreases or increases. As described above, the second combustion chamber 122 is configured to change in volume as the combustion chamber wall 126 moves, but is formed by the partition wall portion 123 and the slide end plate 129 that are fixed to each other and move together. The first combustion chamber 121 is configured to have a steady volume whose volume does not change. That is, the combustion chamber includes a first combustion chamber 121 whose volume does not change even when the combustion chamber wall 126 moves back and forth, and a second combustion chamber 122 whose volume changes.

  A small diameter portion 127 a having a small inner peripheral diameter is formed at the front end portion (opening end side) of the slide sleeve 127 in the combustion chamber wall 126. When the combustion chamber wall 126 is located at the rear end, the small diameter portion 127a has a circular flange portion 153a formed on the outer periphery of an end portion of a cylinder 153 described later and an O-ring 154 on the outer peripheral surface. It is set as the structure which seals the 2nd combustion chamber 122 by sealing via. When the combustion chamber wall 126 is moved forward, the small diameter portion 127a is separated from the flange portion 153a (O-ring 154) soon after the movement starts, and the outer periphery of the O-ring 154 and the inner peripheral surface of the slide sleeve 127 A gap 127b is formed between the inner space 104 of the housing 103 (the gap between the housing 103 and the outer peripheral surface of the cylinder 153, and communicates with the outside of the nail driver 101 through the gap 127b. ).

  An air chamber 171 is formed on the opposite side (rear side) of the first and second combustion chambers 121 and 122 across the slide end plate 129. The atmospheric chamber 171 is a space surrounded by a cylindrical fixed sleeve 177, a slide end plate 129 that is slidably fitted in the fixed sleeve 177, and a fixed end plate 175 that is disposed to face the slide end plate 129. Formed as. The fixed end plate 175 and the fixed sleeve 177 are integrally formed. The fixed end plate 175 constitutes the end wall surface of the atmospheric chamber 171, the fixed sleeve 177 constitutes the peripheral wall surface of the atmospheric chamber 171, and the cylindrical atmospheric chamber wall 173 whose front end portion is opened by these two members is constituted. ing. The sliding surfaces of the fixed sleeve 177 and the slide end plate 129 are sealed through an O-ring 179.

  The fixed end plate 175 is fastened together with a housing cap 106 having a large number of ventilation holes 106b whose outer peripheral edge portions are arranged at the rear end portion of the main housing 103 by fastening with screws (not shown). . Thus, the atmospheric chamber 171 is a space that is separated and fixed from the first and second combustion chambers 121 and 122, and moves with the movement of the combustion chamber wall 126, directly with the movement of the slide end plate 129. It is set as a space where the volume changes. That is, when the slide end plate 129 moves (advances) in the direction of decreasing the volume of the second combustion chamber 122, the volume of the atmospheric chamber 171 increases and moves in the direction of increasing the volume of the second combustion chamber 122 ( When retreating, the volume of the atmospheric chamber 171 is reduced. The maximum volume of the atmospheric chamber 171 is set larger than the total volume of the first and second combustion chambers 121 and 122 when the volume of the second combustion chamber 121 is maximized.

  The fixed end plate 175 in the atmosphere chamber wall 173 includes a space 106a (substantially the atmosphere, hereinafter referred to simply as “atmosphere”) surrounded by the fixed end plate 175 and the housing cap 106, and an atmosphere chamber. An intake port 161 communicating with 171 is provided, and an intake valve 163 is provided in the intake port 161. The intake valve 163 is configured as a check valve that opens and closes the intake port 161 to suck atmospheric air into the atmospheric chamber 171, and is disposed on the atmospheric chamber 171 side. The intake valve 163 is configured to allow the flow of air from the atmosphere to the atmosphere chamber 171 by elastically deforming to the atmosphere chamber 171 side based on the pressure difference between the inside and the outside of the atmosphere chamber 171 and to restrict the reverse flow. It is said. The intake port 161 and the intake valve 163 constitute a “first valve unit”.

  The slide end plate 129 is formed with an intake port 165 that communicates the atmospheric chamber 171 and the first combustion chamber 121, and an intake valve 167 is provided at the intake port 165. The intake valve 167 is configured as a check valve that opens and closes the intake port 165 in order to suck the air in the atmospheric chamber 171 into the first combustion chamber 121, and is disposed on the first combustion chamber 121 side. The intake valve 167 is elastically deformed toward the first combustion chamber 121 based on the pressure difference between the first combustion chamber 121 and the atmospheric chamber 171 to allow the air flow from the atmospheric chamber 171 to the first combustion chamber 121. However, the reverse flow is regulated. The intake port 165 and the intake valve 167 constitute a “second valve means”.

  The fixed end plate 175 in the atmosphere chamber wall 173 is provided with a rod-shaped seal member 169 that projects into the atmosphere chamber 171 with a predetermined length. The seal member 169 is disposed so as to face the combustion chamber intake port 165, and when the combustion chamber wall 126 is positioned at the backward end (rear end side stroke end), the combustion chamber intake port The intake port 165 is sealed by being fitted in the 165, and the front end surface is in contact with the back surface (rear surface) of the intake valve 167 in the fitted state.

  The ignition device 131 includes an ignition plug 133 and a piezoelectric element 138 that supplies a high-voltage current to the ignition plug 133. The ignition part of the ignition plug 133 is mainly composed of two electrodes (anodes) 133a and 133b arranged in opposition, one electrode 133a constituting a center electrode, and the other electrode 133b constituting a ground electrode. To do. Note that the opposing ends of the two electrodes 133a and 133b arranged in an opposing manner correspond to the “ignition region” in the present invention. One electrode 133 a is disposed at the center of the slide end plate 129 that constitutes the end wall surface of the first combustion chamber 121, and the front end is substantially flush with the mounting surface of the slide end plate 129. Is set. The other electrode (cathode) 133b is disposed at a position away from the center portion of the slide end plate 129 and extends toward the center portion side of the first combustion chamber 121, and the tip (front end) of one electrode 133a. Are opposed to each other with a predetermined gap. The ignition part of the spark plug 133 corresponds to the “ignition part” in the present invention, and the piezoelectric element 138 corresponds to the “power supply part” in the present invention.

  One electrode 133 a is electrically connected to the piezoelectric element 138 through a conductive material (metal) ball (steel ball) 134 provided on the fixed end plate 175, a conductive material (metal) spring 135, and an electrical wiring 136. Connected. The ball 134 and the spring 135 constitute a part of the ignition circuit. The ball 134 is disposed so as to face the rear end of one electrode 133a, and is brought into contact with or separated from the one electrode 133a as the combustion chamber wall 126 moves forward or backward. That is, one electrode 133a is electrically connected by contacting the ball 134 when the combustion chamber wall 126 is moved to a position where the volume of the second combustion chamber 122 is near the maximum (near the retreat end). When energization (ignition) is permitted and the combustion chamber wall 126 moves in the direction of decreasing the volume of the second combustion chamber 122, the electrical connection is cut off by separating from the ball 134, thereby restricting energization (ignition). It is set as the structure. The ball 134 and the spring 135 constitute the “energization control unit” in the present invention. The position where the volume of the second combustion chamber 122 is close to the maximum corresponds to the “combustible position” in the present invention.

  The ball 134 is movably fitted in a hole 137a of a holding member 137 made of an electrically insulating material provided on the fixed end plate 175, and is urged toward the electrode 133a by a spring 135. Thus, when the combustion chamber wall 126 is moved rearward, the ball 134 comes into contact with the rear end of the electrode 133a when the combustion chamber wall 126 approaches the retracted end (stroke end). It moves backward while maintaining the contact state. Thus, the spring 135 biases the ball 134 and the electrode 133a so as to stably hold the contact state over a predetermined range. The ball 134 corresponds to the “movable member” in the present invention, and the spring 135 corresponds to the “biasing member” in the present invention. The ignition operation of the igniter 131 is performed by deforming the piezoelectric element 138 by the drawing / retracting operation of the trigger 107 disposed on the handgrip 105 and discharging a high-voltage current generated thereby between the electrodes 133a and 133b. The The other electrode 133b is grounded to the slide end plate 129. The trigger 107 corresponds to the “ignition operation means” in the present invention.

  The fuel injection device 141 is mainly configured by a pipe-shaped member 145 that extends from the first combustion chamber 121 through the partition wall 123 to the second combustion chamber 122, and the pipe-shaped member 145 includes each combustion chamber. A fuel injection hole 143 is formed in a perforated shape at appropriate positions facing the 121 and 122. The fuel injection device 141 is connected to a fuel container (fuel cylinder) 149 and receives supply of fuel. The fuel injection amount by the fuel injection device 141 is individually set according to the effective volumes of the first combustion chamber 121 and the second combustion chamber 122.

  The pipe-shaped member 145 constituting the fuel injection device 141 is fixed to the slide end plate 129, and one end (tip) side is along the inner peripheral surface of the spherical portion 123 b of the partition wall portion 123 constituting the first combustion chamber 121. And extends through the central portion of the spherical portion 123b to the second combustion chamber 122. That is, the protruding tip portion 145 a of the pipe-shaped member 145 that protrudes into the second combustion chamber 122 through the spherical portion 123 b has a center line of the protruding tip portion 145 a passing through the center of the second combustion chamber 122. Are arranged on a center line extending in the long axis direction. As shown in FIG. 8, a plurality of fuel injections penetrating in the radial direction (radial), that is, in a direction substantially perpendicular to the major axis direction, are injected into the projecting tip 145 a as shown in FIG. 8. A hole 143 is provided. When the combustion chamber wall 126 moves in the direction of decreasing the volume of the second combustion chamber 122, the projecting tip portion 145a of the pipe-shaped member 145 is accommodated in a storage space 155b formed at the center of the top surface of the piston 155. Thus, the volume of the second combustion chamber 122 can be reduced to zero or close to zero.

  Further, as clearly shown in FIG. 7, the pipe-shaped member 145 has at least one injecting fuel into the first combustion chamber 121 in the curved portion 145 b disposed along the inner peripheral surface of the spherical portion 123 b. A fuel injection hole 143 is provided. The combustion injection hole 143 is set so as to inject fuel toward the ignition unit of the ignition device 131. Of the electrodes 133a and 113b constituting the ignition unit of the ignition device 131, the other electrode 133b is disposed in a projecting manner in the first combustion chamber 121, and a predetermined gap (plug gap) is provided in the one electrode 133a. In order to face each other, it is bent into an L shape and extends. In the present embodiment, in order to prevent the fuel from directly falling between the plug gaps, the pipe-shaped member 145 is arranged so as to inject the fuel toward the back side of the other electrode 133b. That is, the pipe-shaped member 145 is arranged so that the fuel injected from the fuel injection hole 134 of the curved portion 145b is injected toward the one electrode 133a across the extending portion of the other electrode 133b.

  The other end (base end) side of the pipe-shaped member 145 extends between the outer peripheral surface of the slide sleeve 127 and the inner peripheral surface of the fixed sleeve 177 and guides the fuel supplied from the fuel container 149. The fuel passage constituting member 146 is inserted into the fuel supply passage 147 and slides in the fuel supply passage 147 as the combustion chamber wall 126 moves. The fuel supply from the fuel container 149 is performed in conjunction with the operation of pressing the contact arm 111 against the workpiece W.

  The drive unit 151 mainly includes a cylinder 153 accommodated in the main housing 103, a piston 155 slidably disposed in the cylinder 153, and a piston rod 157 integrally connected to the piston 155. Is done. The distal end side of the piston rod 157 is arranged in the injection unit 110 and connected to an injection device for driving a nail (not shown) forward. A cushion rubber 159 for absorbing and reducing the impact of the piston 155 driven at high speed and receiving the piston 155 is appropriately disposed on the tip side inside the cylinder 153. Further, the cylinder 153 is provided with a check valve 113 for opening and closing a vent 114 communicating with the interior space 104 of the housing 103 in the bore 153 a of the cylinder 153. The check valve 113 allows the gas in the bore 153a of the cylinder 153 to flow into the internal space 104, while restricting the gas in the internal space 104 from flowing into the bore 153a of the cylinder 153. It is configured as.

The magazine 109 is attached to an injection part 110 formed on the front end side of the main housing 103 of the nailing machine 101 and accommodates a large number of nails connected to each other and makes the nail to be driven face the injection part 110. . Since the configuration of the magazine 109 itself is well known, detailed description thereof is omitted for the sake of convenience.
The above-described contact arm 111 is disposed at the tip of the injection unit 110. The contact arm 111 slides relative to the injection unit 110 in the long axis direction of the injection unit 110 (that is, the long axis direction of the nailing machine 101 and corresponds to the left-right direction in FIGS. 1 to 5). It can be moved and is normally urged by the spring 112 toward the tip side (left side in FIGS. 1 to 5). The spring 112 also serves as the biasing means for the slide sleeve 127 described above.

  The nailing machine 101 according to the present embodiment is configured as described above. Next, the operation of the nailing machine 101 will be described. The nailing machine 101 always has the initial state shown in FIG. In this initial state, the combustion chamber wall 126 is moved forward by the biasing force of the spring 112, the volume of the second combustion chamber 122 is reduced to the minimum (a state of zero or close to zero), and the volume of the atmospheric chamber 171 is reduced. Has been increased to the maximum. The piston 155 is located at the top dead center. Also, one electrode 133a of the ignition plug 133 is separated from the ball 134, and the electrical connection between the piezoelectric element 138 and the electrode 133a is cut off, thereby restricting the ignition of the plug.

  In order to perform the nail driving operation using the nail driver 101 in such a state, as shown in FIG. 2, the contact arm 111 is first brought into contact with the workpiece W, and then the operator moves the workpiece in the direction of the workpiece. The nail driver 101 is made to act on the nailing machine 101. Then, the contact arm 111 moves backward toward the side away from the workpiece W while resisting the urging force of the spring 112. As the contact arm 111 moves backward, the combustion chamber wall 126 connected to the contact arm 111 moves backward. By the retreating operation of the combustion chamber wall 126, the volume of the second combustion chamber 122 is increased and the volume of the atmospheric chamber 171 is decreased. The movement of the combustion chamber wall 126 is regulated by the outer peripheral rear end portion of the slide end plate 129 coming into contact with the outer peripheral front end surface of the fixed end plate 175 of the atmospheric chamber wall 173. At this time, the volume of the second combustion chamber 122 is maximized, and the volume of the atmospheric chamber 171 is minimized. Further, the volume of the first combustion chamber 121 and the volume of the second combustion chamber 122 are set to a predetermined volume ratio.

  Further, when the combustion chamber wall 126 moves backward and approaches the retracted end, one electrode 133a comes into contact with the ball 134 and is electrically connected to the piezoelectric element 138 via the ball 134, the spring 135 and the electric wiring 126. It becomes the state. Furthermore, the seal member 169 fits into the intake port 165 for the combustion chamber for sealing, and the tip of the seal member 169 contacts the back surface of the intake valve 167.

  Further, when the combustion chamber wall 126 is retracted, fuel is supplied from the fuel container 149 when the combustion chamber wall 126 approaches the retracted end, and the fuel is fed through the fuel supply passage 147 and the pipe-shaped member 145. Then, the fuel is injected into the combustion chambers 121 and 122 from the fuel injection hole 143 provided in the pipe-shaped member 145 (see FIG. 7). In this case, in the present embodiment, in the first combustion chamber 121, the fuel is injected from the fuel injection hole 143 of the curved portion 145 b of the pipe-shaped member 145 into the spark plug in order to enhance the ignition effect at the time of ignition performed thereafter. It is set as the structure injected toward the center, ie, an ignition part. On the other hand, in the second combustion chamber 122, fuel is injected radially into the second combustion chamber 122 from the fuel injection hole 143 of the projecting tip 145a. The amount of fuel supplied to the first and second combustion chambers 121 and 122 is set according to the volume of each combustion chamber 121 and 122, respectively. The injected fuel is mixed with the air in the combustion chambers 121 and 122, whereby the combustion chambers 121 and 122 are filled with the air-fuel mixture. This air-fuel mixture corresponds to the “combustible gas” in the present invention.

  After the retracting operation of the contact arm 111, when the operator pulls and operates the trigger 107 provided on the hand grip 105, an ignition operation is performed by the ignition device 131 provided in the first combustion chamber 121. As a result, the ignition / combustion operation in the first combustion chamber 121 is realized smoothly and with high efficiency.

  When the ignition device 131 performs an ignition operation, as shown in FIG. 3, the air-fuel mixture filled in the first combustion chamber 121 is ignited from the vicinity of the ignition unit, and the air-fuel mixture in the first combustion chamber 121 is combusted. Is started. The combustion action of the air-fuel mixture is explosive, and the combustion surface (flame surface) of the air-fuel mixture reaches the partition wall 123 in a very short time. At this time, in the present embodiment, the partition wall portion 123 is configured as a spherical portion 123b having a substantially equal diameter centered on the ignition portion, so that the combustion surface of the air-fuel mixture emitted from the ignition portion is the ignition portion. To the spherical portion 123b having the same radius with respect to each other at the same time. For this reason, it is possible to unify the ignition timing of the second combustion chamber 122 in each communication hole 125 over the entire boundary surface of the partition wall 123, and the combustion start timing in the second combustion chamber 122 is effective. It is possible to control.

  The air-fuel mixture filled in the second combustion chamber 122 is simultaneously ignited from the entire surface area of the partition wall portion 123 through the communication holes 125, and combustion of the air-fuel mixture in the second combustion chamber 122 is started. The volume of the second combustion chamber 122 is set larger than the volume of the first combustion chamber 121, and a large combustion pressure is generated by the combustion of the air-fuel mixture in the second combustion chamber 122. Thereby, the piston 155 is moved (moved forward) in a sliding manner in the cylinder 153 toward the workpiece.

  When the piston 155 slides in the cylinder 153, the internal space of the cylinder 153 on the piston rod 157 side is reduced along with the sliding operation, but the air in the space passes through the check valve 113 to the outside. Since it is discharged into the (internal space 104 of the housing 103), the sliding movement of the piston 155 is not hindered. Further, when the first combustion chamber 121 is combusted, the inside of the first combustion chamber 121 is in a considerably high pressure state. In the present embodiment, the intake valve is provided by the seal member 169 inserted into the intake port 165 for the combustion chamber. 167 supports the back surface of the 167, thereby protecting the intake valve 167 from being deformed or damaged by a high pressure during combustion, improving the durability of the intake valve 167, and allowing the gas in the first combustion chamber 121 to flow into the intake port. Outflow from 165 to the atmospheric chamber 171 can be prevented in advance.

  In conjunction with the sliding movement of the piston 155 in the cylinder 153, the piston rod 157 moves linearly in the direction of the work material, so that the nail set on the injection portion 110 moves toward the work material side at high speed. It is injected and driven in. At this time, the piston 155 that has moved at high speed in the direction of the workpiece in the cylinder 153 comes into contact with the cushion rubber 159, and its kinetic energy is absorbed and relaxed to stop. That is, the piston 155 reaches the bottom dead center and stops. This state is shown in FIG. When the piston 155 passes through the check valve 113 during the movement to the bottom dead center of the piston 155, the exhaust gas in the first and second combustion chambers 121 and 122 used for the forward movement of the piston 155 is It is discharged out of the room (inner space 104 of the housing 103) through the check valve 113.

At the stage where the nail driving operation is completed, the exhaust gas is discharged from the check valve 113, and a contraction cooling action is generated in the first and second combustion chambers 121 and 122. As a result, a negative pressure is generated in the first and second combustion chambers 121 and 122, and a suction action is generated. For this reason, the piston 155 automatically starts moving backward toward the side away from the workpiece W. At this time, in this embodiment, since the combustion chamber intake port 165 is sealed by the seal member 169, air is prevented from flowing into the first combustion chamber 121 from the atmospheric chamber 171 and the piston 155 is It is possible to reliably return to the initial position.
Further, by releasing the pressure applied to the nailing machine 101 that the operator has acted in the direction of the workpiece, as shown in FIG. Then, it moves forward (in the direction of the workpiece) via the biasing force of the spring 112. As the contact arm 111 moves forward, the combustion chamber wall 126 moves forward (piston 155 side). Accordingly, the small diameter portion 127a of the slide sleeve 127 of the combustion chamber wall 126 is separated from the flange portion 153a of the cylinder 153, and a gap 127b is generated between the inner peripheral surface of the slide sleeve 127 and the outer peripheral surface of the flange portion 153a. The two combustion chambers 122 are communicated with the outside (the internal space 104 of the housing 103) through the gap 127b.

  By the way, the forward movement of the combustion chamber wall 126 toward the front end is governed by the release time of the operator's pressing load in the direction of the workpiece against the nailing machine 101. The forward movement is performed after the backward movement of the piston 155 is completed. That is, the backward movement of the piston 155 is instantaneously performed by the suction force (negative pressure) accompanying the cooling action generated in the first and second combustion chambers 121 and 122. Therefore, as long as the operator normally releases the pressing load of the nailing machine 101 in the direction of the workpiece, the piston 155 finishes the retreating operation at a stage before the advancement operation of the combustion chamber wall 126 is started. Thus, the initial position (see FIG. 4) before starting the forward movement is returned. At this time, as described above, since the combustion chamber intake port 165 is sealed by the seal member 169, the inflow of air from the atmospheric chamber 171 to the first combustion chamber 121 is suppressed, and thereby the first and The negative pressure state of the second combustion chambers 121 and 122 can be maintained, and the piston 155 can be reliably returned to the initial position.

  As shown in FIG. 4, the forward movement of the combustion chamber wall 126 reduces the volume of the second combustion chamber 122, and the gap 127b between the inner peripheral surface of the slide sleeve 127 and the outer peripheral surface of the flange portion 153a. Then, the second combustion chamber 122 is communicated with the outside. Then, the exhaust gas in the second combustion chamber 122 is discharged to the outside through the gap 127b as the volume of the second combustion chamber 122 is reduced. On the other hand, the forward movement of the combustion chamber wall 126 causes the slide end plate 129 to move away from the fixed end plate 175, and as a result, the volume of the atmospheric chamber 171 increases, and the seal member 169 comes out of the intake port 165 for the combustion chamber, The intake port 165 is opened. Further, one electrode 133a is separated from the ball 134, and the electrical connection to the piezoelectric element 138 is cut off.

  When the volume in the atmospheric chamber 171 is increased, the pressure in the atmospheric chamber 171 decreases accordingly. As a result, due to the pressure difference between the pressure in the atmospheric chamber 171 and the atmospheric pressure in the housing cap 106, the air in the housing cap 106 is sucked from the air inlet 161 for the atmospheric chamber by pushing away the suction valve 163. At this time, the combustion chamber intake valve 167 is in close contact with the peripheral edge of the combustion chamber intake port 165 to prevent the exhaust gas in the first combustion chamber 121 from flowing out (leaking) into the atmosphere chamber 171. . When the combustion chamber wall 126 reaches the forward end (stroke end), the volume of the second combustion chamber 122 becomes minimum (zero), and the exhaust gas in the second combustion chamber 122 is discharged to the outside. The volume of the atmospheric chamber 171 is maximized, and fresh air is stored in the atmospheric chamber 171. That is, the initial state shown in FIG. 1 is restored. At the time of returning to the initial state, the tip protruding portion 145 a of the pipe-like member 145 protruding into the second combustion chamber 122 is accommodated in the storage space 155 b provided in the piston 155.

  When the contact arm 111 is subsequently pressed against the workpiece W to perform the nailing operation, the combustion chamber wall 126 is moved backward as described above. This state is shown in FIG. By the retreating operation of the combustion chamber wall 126, the volume of the second combustion chamber 122 is increased and the volume of the atmospheric chamber 171 is decreased. Therefore, the air in the atmospheric chamber 171 is compressed and the intake air for the combustion chamber is compressed. The suction valve 167 is pushed away from the port 165 and forced into the first combustion chamber 121. By the forced pushing of the air into the first combustion chamber 121, the exhaust gas remaining in the first combustion chamber 121 is pushed out to the second combustion chamber 122 through the communication hole 125, and further through the gap 127b. It is discharged outside. That is, the exhaust gas remaining in the first combustion chamber 121 is pushed out to the second combustion chamber 122 by the air flowing in from the atmospheric chamber 171 and then released to the outside, and the first and second combustion chambers 121, 122, so-called scavenging is performed. In this case, since a large number of communication holes 125 are arranged in the spherical portion 123 b of the partition wall 123, the air flows substantially uniformly throughout the second combustion chamber 122. Thus, in the first and second combustion chambers 121 and 122, the replacement of the exhaust gas with the air is smoothly performed, and the residual amount of the exhaust gas is reduced. As a result, particularly in the case where the nail driving operation is performed continuously, it is effective in optimizing the mixing ratio of the fuel and air injected into the first and second combustion chambers 121 and 122 next time. Become.

  When the combustion chamber wall 126 reaches the retracted end (state shown in FIG. 2), the first and second combustion chambers 121 and 122 are filled with fresh air. In this case, in the present embodiment, the maximum volume of the atmospheric chamber 171 is set larger than the maximum total volume of the first and second combustion chambers 121 and 122. For this reason, air having a volume exceeding those volumes is sent into the first and second combustion chambers 121 and 122, and the exhaust gas in the first and second combustion chambers 121 and 122 is reliably discharged to the outside. It can be discharged and replaced with fresh air.

  When the combustion chamber wall 126 reaches the retracted end, the electrode (anode) 133a comes into contact with the ball 134 and is electrically connected to the piezoelectric element 138 via the ball 134, the spring 135 and the electric wiring 126, and the ignition is performed. Operation is allowed. In addition, the seal member 169 is inserted into the combustion chamber intake port 165 to seal the intake port 165, and abuts against the back surface of the intake valve 167 to prepare for a high pressure action on the intake valve 167. Further, the inner peripheral surface of the small diameter portion 127a of the slide sleeve 127 is in sliding contact with the outer peripheral surface of the flange portion 153a of the cylinder 153 via the O-ring 154, thereby closing the gap 127b. Thereby, the 2nd combustion chamber 122 is made into sealed space. In this state, when the trigger 107 is pulled and drawn, the above-described operation is repeated and the nail driving work is performed.

As described above, according to the present embodiment, the combustion chamber wall 126 is moved back and forth in the combustion chamber structure having the first combustion chamber 121 whose volume does not change and the second combustion chamber 122 whose volume changes. By changing the volume of the atmospheric chamber 171 and exhausting the exhaust gas in the second combustion chamber 122 to the outside, the air taken into the atmospheric chamber 171 is forcibly sent into the first combustion chamber 121. Thus, the exhaust gas remaining in the first combustion chamber 121 is discharged from the first combustion chamber 121 to the outside through the second combustion chamber 122. As a result, the exhaust gas in the first and second combustion chambers 121 and 122 is efficiently discharged to the outside without changing the volume of the first combustion chamber 121, and the first and second combustion chambers 121 and 122 are discharged. It becomes possible to fill the inside with fresh air.
That is, in the present embodiment, in the nailing machine 101 in which the combustion chamber is composed of the first and second combustion chambers 121 and 122, the ignition plug 133 is connected to the first combustion chamber 121 in order to increase the combustion efficiency of the air-fuel mixture. In addition, the partition wall portion 123 is centered on the ignition portion so that the combustion surface of the air-fuel mixture ignited by the ignition portion in the first combustion chamber 121 reaches the communication hole 125 of the partition wall portion 123 almost simultaneously. The configuration has a spherical portion 123b having a radius. In such a configuration, it becomes difficult to change (decrease) the volume of the first combustion chamber 121 and exhaust the exhaust gas, but according to the present embodiment, the first combustion chamber 121 to the second combustion chamber. In order to improve the combustion efficiency of the air-fuel mixture by efficiently performing the flame injection to 122, the exhaust gas is discharged while maintaining the configuration in which the shape of the partition wall 123 forming the first combustion chamber 121 is formed in a hemispherical shape. The action can be performed effectively.

  In this case, since the maximum volume of the atmospheric chamber 171 is set to be larger than the total volume of the first and second combustion chambers 121 and 122, the first and second combustion chambers 121 and 122 have capacities exceeding those volumes. By sending in air, it is possible to reliably replace the exhaust gas and air. When the nailing operation is continuously performed, that is, when the volume of the second combustion chamber 122 is repeatedly reduced and increased within a short time, the exhaust gas discharged from the second combustion chamber 122 is reduced. It may exist around the exit. Then, when the volume of the second combustion chamber 122 is increased, the exhaust gas may be sucked into the combustion chamber again, that is, may flow backward. In the present embodiment, since the so-called backflow prevention means is configured by sending air having a volume exceeding those volumes to the first and second combustion chambers 121 and 122, the combustion chambers for exhaust gas. It is possible to reliably prevent backflow to the. Further, in the present embodiment, since the first combustion chamber 121 has a steady configuration in which the volume does not change, the ignition device 131 or the fuel supply pipe-like member 145 is provided in the center of the first combustion chamber 121. The bending portion 145b can be arranged and set. Thereby, the flame (combustion surface of the combustible gas) generated in the first combustion chamber 121 can be evenly and efficiently injected into the second combustion chamber 122.

  Further, in the present embodiment, the ball 134 electrically connected to the piezoelectric element 138 is disposed so as to face the one electrode 133a that constitutes the ignition unit, and the combustion chamber wall 126 moves to the vicinity of the backward end. When the electrode 133a is moved, the electrode 133a is allowed to be energized, and in a state where the combustion chamber wall 126 is positioned in front of the retreat end, the electrode 133a is separated from the electrode 133a. It is set as the structure which regulates the electricity supply with respect to. By adopting such a configuration, in the nailing machine 101 configured to move the combustion chamber wall 126 in order to introduce air into the first and second combustion chambers 121 and 122 or exhaust the exhaust gas, ignition is performed. It is possible to rationally supply power to the ignition part while making cordless to the part possible. In the nailing machine 101 configured to move the combustion chamber wall 126, if the piezoelectric element 138 and the electrode 133 a of the ignition unit are directly connected by electric wiring, the movement of the combustion chamber wall 126 is allowed to the electric wiring. It is necessary to set a slack portion necessary for the housing, and to secure an accommodation space for accommodating the slack portion of the electric wiring on the other side of the housing. However, according to the present embodiment, such a problem can be solved, and the ignition part, and thus the combustion chamber wall 126 can be moved significantly without being restricted by the cord.

  Further, in the present embodiment, when the combustion chamber wall 126 moves to the vicinity of the retracted end, that is, the first and second combustion chambers 121 and 122 are filled with the combustible gas, and the combustible gas can be burned. In this state, the electrode 133a is allowed to be energized in the state of being set, so that the ignition in the first combustion chamber 121 can be reliably performed at the time when ignition is required. In this embodiment, the ball 134 and the spring 135 that urges the ball 134 are used as energizing members, respectively, and the ball 134 is configured to follow the predetermined range together with the electrode 133a in a state where the ball 134 is in contact with the electrode 133a. As a result, the energization region can be widened, and the power feeding operation can be stabilized. Further, the impact at the time of contact between the electrode 133a and the ball 134 can be absorbed by the elastic deformation of the spring 134, and the power feeding function can be maintained even if wear progresses.

In the present embodiment, the inner wall surface (end slide plate 129) in the long axis direction of the first combustion chamber 121 is configured by a flat surface, and the ignition unit is disposed at the center, but the ignition unit is disposed. For example, a tapered or curved concave portion is formed so as to go toward the piston 155 toward the peripheral edge of the inner wall surface with the central position as a reference position, and the concave portion substantially faces the ignition portion. One, that is, a substantially flat surface may be formed. According to such a configuration, the ignition portion that actually ignites the combustible gas is connected to the concave portion of the inner wall surface in a flush manner, so that the combustion surface of the combustible gas has a concave inner wall surface from the start of ignition. Can be smoothly guided to the partition wall 123 side (that is, the piston 151 side).
Further, although the present embodiment has been described in the case of the nailing machine 101 having a configuration in which the combustion chamber is partitioned into the first and second combustion chambers 121 and 122, the nailing machine having a configuration formed from a single combustion chamber. You may apply to. In the present embodiment, the energization control unit is configured by the ball 134 and the spring 135 made of a conductive material. Instead, for example, a ring-shaped or sleeve-shaped energization member is provided, and the electrode 133a is inserted into these energization members. By doing so, it is possible to adopt a configuration that allows energization. In the present embodiment, the ball 134 is in direct contact with the electrode 133a so that the ignition portion is allowed to be energized. As an example, a conductive piece having one end connected to one electrode 133a is set directly on the slide end plate 129 of the combustion chamber wall 126 or via an appropriate bracket, and a terminal is connected to the other end of the conductive piece. This is a configuration in which the terminal and a current-carrying member such as a ball are arranged to face each other, and energization to the ignition unit is permitted or restricted by contact or separation between the terminal and the current-carrying member. Further, although the present embodiment has been described in the case of a nail driver, it can be applied to a tacker used for a so-called stable driving operation.

1 is a partial cross-sectional view in front view showing the overall configuration of a nailing machine according to the present embodiment, showing an initial state where a piston is located at a top dead center. Similarly, it is a front sectional view showing the overall configuration of the nailing machine, and shows a state in which the volume of the second combustion chamber is increased to the maximum by retreating the combustion chamber wall. Similarly, it is a partial sectional view in front view showing the overall configuration of the nailing machine, and shows a nail driving completion state in which the piston is moved to the bottom dead center. Similarly, it is a front view partial sectional view showing the entire configuration of the nailing machine, and shows the exhaust state of exhaust gas in the second combustion chamber. Similarly, it is a front sectional view showing the entire configuration of the nailing machine, and shows the exhaust state of residual exhaust gas in the first combustion chamber. It is an expanded sectional view of a combustion chamber peripheral part, and shows the halfway state where the volume of the 2nd combustion chamber decreases (or increases). It is an expanded sectional view of a combustion chamber peripheral part, and shows the state where the volume of the 2nd combustion chamber was increased to the maximum. It is the IIX-IIX sectional view taken on the line of FIG.

Explanation of symbols

101 Nail driver (combustion work tool)
103 Main housing 104 Internal space 105 Hand grip 106 Housing cap 106a Space 106b Vent hole 107 Trigger 109 Magazine 110 Injection part 111 Contact arm 113 Check valve 114 Vent 121 121 First combustion chamber (first combustion chamber)
122 2nd combustion chamber (2nd combustion chamber)
123 Partition (partition wall)
123a Flat surface portion 123b Spherical portion 125 Communication hole 126 Combustion chamber wall 127 Slide sleeve 127a Small diameter portion 127b Gap 128 Screw 129 Slide end plate 131 Ignition device 133 Ignition plug 133a One electrode (ignition portion)
133b The other electrode (ignition part)
134 balls (energization controller)
135 Spring (energization controller)
136 Electrical Wiring 137 Holding Member 138 Piezoelectric Element (Power Supply Unit)
141 Fuel injection device 143 Fuel injection hole 145 Pipe-shaped member 145a Projection tip 145b Curved portion 146 Fuel passage component member 147 Fuel supply passage 149 Fuel container 151 Drive portion 153 Cylinder 153a Flange portion 154 O-ring 155 Piston (piston member)
155a Spherical recess 155b Storage space 157 Piston rod 159 Cushion rubber 161 Air chamber inlet 163 Suction valve 165 Combustion chamber air inlet 167 Suction valve 169 Air chamber 173 Air chamber wall 175 Fixed end plate 177 Fixed sleeve 179 O-ring

Claims (4)

A combustion chamber;
A combustion chamber wall constituting the combustion chamber;
An ignition unit having an ignition region facing the combustion chamber;
A power supply unit for supplying power to the ignition unit;
A cylinder connected to the combustion chamber;
A piston member slidably accommodated in the cylinder,
The combustion chamber wall is configured to introduce air into the combustion chamber or move to discharge exhaust gas,
In a state where the combustion chamber wall has been moved to a combustible position that allows combustion of combustible gas in the combustion chamber, the combustible gas is combusted by the ignition unit in the combustion chamber, and the combustion pressure generated thereby A combustion-type work tool that performs a predetermined machining operation by moving the piston member forward to the tip side,
The power supply unit is electrically connected, and has an energization control unit disposed separately from the ignition unit,
In the state where the combustion chamber wall is moved to the combustible position, the energization control unit is configured to energize the ignition unit from the power supply unit by contacting the ignition unit as the combustion chamber wall moves. In a state where the combustion chamber wall is moved to a position other than the combustible position, energization from the power supply unit to the ignition unit is regulated by being separated from the ignition unit. Combustion work tool. It is a combustion type work tool according to claim 1,
The energization control unit is movable in the same direction as the movement direction of the combustion chamber wall, and a movable member that is separated from or in contact with the ignition unit that moves together with the combustion chamber wall, and the movable member is ignited. A combustion type work tool characterized in that the movable member and the biasing member are each formed of a conductive material. It is a combustion type work tool according to claim 1 or 2,
A contact arm that is disposed on the distal end side of the tool body, is normally biased toward the distal end side, and is moved backward relative to the tool body by being pressed against the workpiece;
Ignition operation means for operating ignition of the ignition unit,
The ignition operation is performed in a state in which the combustion chamber wall is moved to the combustible position by the retreating operation of the contact arm based on the pressing of the contact arm against the workpiece, whereby the energization control unit is in contact with the ignition unit. A combustion-type work tool characterized in that the electric power of the power supply unit is energized to the ignition unit by an ignition operation by means. It is a combustion type work tool in any one of Claims 1-3,
The partition has a partition that divides the combustion chamber into a first combustion chamber and a second combustion chamber, and the ignition unit is disposed in the first combustion chamber, and the partition has a spherical shape with the ignition unit as a center. And a plurality of communication holes that are disposed in the spherical portion and communicate with the first combustion chamber and the second combustion chamber, and the igniter causes the combustible gas in the first combustion chamber to flow. A combustion-type work tool characterized in that when combusted, the combustion surface of the combustible gas in the first combustion chamber reaches the communication holes almost simultaneously.

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