JP2005040875A - Combustion power tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a combustion power tool which rationally exhausts combustion gas by a simple structure. <P>SOLUTION: This combustion power tool has: a first combustion chamber 121 and a second combustion chamber 122 in which inflammable gas is filled; an ignition device 131 provided in the first combustion chamber; a bulkhead part 123 for partitioning the first combustion chamber from the second combustion chamber; a communicating hole arranged in the bulkhead part to communicate the first combustion chamber with the second combustion chamber; and a driving part 151 for performing predetermined machining work by utilizing combustion pressure generated by combustion of inflammable gas in the combustion chambers. The combustion gas after combustion in the second combustion chamber is led into the first combustion chamber by moving the bulkhead part onto a second combustion chamber side and reducing volume of the second combustion chamber and is exhausted to the outside together with combustion gas in the first combustion chamber. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a work tool that performs a predetermined machining operation using a high pressure (impact force) when a combustible gas is burned, that is, a rational construction technique of a combustion type work tool.
[0002]
[Prior art]
Regarding a so-called combustion type work tool, Japanese Patent No. 2997581 (Patent Document 1) discloses a specific example in which a piston / cylinder type internal combustion engine is used as a drive source of a work tool such as a nailing machine or a tacker. In Patent Document 1, in an internal combustion engine having a combustion chamber divided into a plurality of chambers in order to improve combustion efficiency, the volume of the combustion chamber is reduced to zero after the combustion stroke (explosion stroke) of the combustible gas in the combustion chamber. A technique has been disclosed in which the combustion gas in the combustion chamber can be rationally discharged to the outside by reducing the pressure to a close state.
[0003]
In the technique disclosed in Patent Document 1, the combustion chamber is divided into a plurality of chambers by two partition walls that can move along the inner wall of the combustion chamber housing, and the piston returns in the exhaust stroke of the combustion gas. By adopting a configuration in which the two partition walls are moved in conjunction with each other, a complete volume reduction in the combustion chamber is realized. However, according to the configuration in which the volumes of the plurality of combustion chambers are reduced to a state close to zero as described above, there is room for improvement in that the structure becomes extremely complicated and the weight increases.
[0004]
[Patent Document 1]
Japanese Patent No. 2997581
[0005]
[Problems to be solved by the invention]
This invention is made | formed in view of this point, and it aims at providing the technique which can be rationally performed, although it is a simple structure, in the combustion type work tool.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the invention described in each claim is configured.
According to invention of Claim 1, the combustion type work tool which has the 1st and 2nd combustion chamber in which combustible gas is combusted is comprised. The first and second combustion chambers are filled with combustible gas. The combustible gas is typically supplied as an air-fuel mixture in which fuel and air are appropriately mixed in a spray form. In the present invention, it is sufficient that at least the first combustion chamber and the second combustion chamber are provided, and a configuration in which a further combustion chamber is separately disposed is also suitably included. The ignition device is provided in the first combustion chamber. The ignition device is typically constituted by a spark plug. The partition wall partitions the first and second combustion chambers. As a utilization form of the plurality of combustion chambers, the first combustion chamber is used as an ignition region for the air-fuel mixture, and the second combustion chamber is used as a region for obtaining large combustion energy necessary for work. Is preferred.
[0007]
In the present invention, the partition wall is provided with a communication hole, and the first combustion chamber and the second combustion chamber communicate with each other through the communication hole. In addition, as "a partition by a partition part", when a partition part partitions between the 1st combustion chamber and the 2nd combustion chamber transversely, both are extendedly connected on the common long axis. It is possible to adopt various forms such as an aspect in which the first combustion chamber is formed or a part in the second combustion chamber that is provided to the first combustion chamber by the partition wall.
[0008]
In the present invention, the combustible gas in the first combustion chamber is burned by the ignition device, and the combustion surface generated in the first combustion chamber is propagated to the second combustion chamber through the communication hole of the partition wall. The combustible gas in the combustion chamber 2 is burned. And the drive part in this invention performs a predetermined | prescribed processing operation by utilizing the combustion pressure which arose by this combustion action. Typically, the “predetermined processing operation” corresponds to an operation tool (such as a nailing machine) for driving nails, staples, or the like into a workpiece.
[0009]
As a characteristic configuration of the present invention, the combustion gas after combustion in the second combustion chamber moves the partition wall toward the second combustion chamber to reduce the volume of the second combustion chamber. In addition to being guided to the combustion chamber, the exhaust gas is discharged together with the combustion gas in the first combustion chamber. According to such a configuration, the combustion gas in the second combustion chamber can be discharged to the outside through the first combustion chamber. That is, in the present invention, the combustion gas is discharged without reducing the volume in the first combustion chamber. Therefore, compared with the conventional technique in which the volume is reduced for all of the plurality of combustion chambers. It is possible to achieve a reasonable exhaust of combustion gas with a simple configuration. Here, the “decrease in volume” includes not only a mode in which the original volume is decreased but also a mode in which the volume is reduced to a state close to zero or a mode in which the volume is completely zero.
[0010]
In addition, the combustion gas introduced from the second combustion chamber to the first combustion chamber or the combustion gas in the first combustion chamber causes the combustion gas in the second combustion chamber to be changed to the first by the volume reduction of the second combustion chamber, for example. It is preferable that a gas flow flowing in a predetermined direction is formed in the first combustion chamber when the gas is introduced into one combustion chamber, and is discharged to the outside by this gas flow. If comprised in this way, since it can exhaust using the gas flow itself of a combustion gas, complication of a structure is avoided and rational exhaust_gas | exhaustion is implement | achieved. Alternatively, the combustion gas in the first combustion chamber can be configured to be actively replaced with outside air by using a scavenging fan, or can be configured to be replaced with outside air through an open / close vent having a sufficient size. is there.
[0011]
(Invention of Claim 2)
According to the second aspect of the present invention, the volume reduction of the second combustion chamber in the combustion-type work tool according to the first aspect is such that the partition wall portion, and the partition wall portion and the second combustion chamber are sandwiched between each other. It is set as the structure performed by the movement operation | movement to the direction which mutually approaches with the piston arrange | positioned in this. The movement of the piston in this case is typically a suction force generated in the second combustion chamber after combustion of the combustible gas, that is, a suction force generated based on a pressure drop caused by cooling in the second combustion chamber. Carried out by. On the other hand, the movement of the partition wall is typically performed by an external operation by an operator via an operation means. In the case of the configuration in which the piston is moved backward by the suction force generated in the second combustion chamber, the mode of the “partitioning portion and piston moving operation” is the state after the piston moving operation is completed. It preferably includes an embodiment performed after returning to the initial position. However, as long as the piston is forcibly retracted using a means other than the suction force, the embodiment is not limited to the above mode, and the mode in which the piston and the partition wall portion move simultaneously, or the movement of the partition wall portion precedes the movement of the piston. Even if it is an aspect to carry out, this is included suitably. According to such a configuration, a combustion type work tool having a simple and rational exhaust system is provided. For example, when the operation tool is a nailing machine, the “operation means” corresponds to a contact arm provided for opening and closing a bleed hole communicating with the combustion chamber and the outside.
[0012]
(Invention of Claim 3)
According to the third aspect of the present invention, the partition wall in the combustion type work tool according to the first or second aspect is formed with an exhaust port that guides the combustion gas in the second combustion chamber to the first combustion chamber. The exhaust port is opened by the movement of the partition wall after combustion in the direction of decreasing the volume of the second combustion chamber, and is closed by the return to the initial position before the movement of the partition wall. “Closing” may be an aspect in which the communication between the second combustion chamber and the first combustion chamber is blocked, or an aspect in which some communication is allowed. According to such a configuration, since the exhaust port can be opened and closed using the movement of the partition wall, the exhaust port opening and closing mechanism can be simplified.
[0013]
(Invention of Claim 4)
According to a fourth aspect of the present invention, in the combustion type work tool according to the first aspect, the combustion gas introduced into the first combustion chamber is directed in a predetermined direction formed in the first combustion chamber. It is configured to be discharged together with the combustion gas in the first combustion chamber by the gas flow.
That is, according to the combustion type work tool according to the fourth aspect, the combustion gas introduced from the second combustion chamber to the first combustion chamber or the combustion gas in the first combustion chamber is the second combustion chamber. When the combustion gas in the second combustion chamber is first guided into the combustion chamber by reducing the volume of the gas, a gas flow that flows in a predetermined direction is formed in the first combustion chamber, and is discharged to the outside by this gas flow. Composed. According to this configuration, exhaust can be performed by the gas flow of the combustion gas, so that the structure is prevented from becoming complicated and rational exhaust is realized.
[0014]
(Invention of Claim 5)
According to the fifth aspect of the present invention, in the combustion type work tool according to any one of the first to fourth aspects, the combustion gas introduced into the first combustion chamber is one of the first combustion chambers. It is configured to flow in an inclined manner from one corner to the other corner. Typically, when the gas gas inlet (exhaust port) is set at the corner of the partition wall that divides the first combustion chamber and the second combustion chamber, the gas flow is changed from the inlet to the gas flow. This corresponds to a flow that crosses the axis of one combustion chamber in an inclined manner toward a corner on the wall surface facing the partition wall, that is, a flow along a diagonal line.
[0015]
According to the present invention, by forming the gas flow as described above in the first combustion chamber, the combustion gas guided from the second combustion chamber to the first combustion chamber, and the combustion gas in the first combustion chamber Can be discharged efficiently and smoothly toward the outside, thereby realizing effective discharge of the combustion gas.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
The whole structure of the nailing machine 101 which concerns on embodiment of this invention is shown by FIGS. 1-3. The nailing machine 101 is an example of the “combustion-type work tool” in the present invention, and the main housing 103, the injection unit 110, the hand grip 105, and the magazine 109 form an outer shell. 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. In addition, a bleed hole 104 is formed at a location in the main housing 103 close to the first combustion chamber 121. The extraction hole 104 allows the first combustion chamber 121 to communicate with the outside (atmosphere).
[0017]
As shown in FIG. 2, the first combustion chamber 121 has a partition wall 123 for partitioning the first combustion chamber 121 from the second combustion chamber 122 and a substantially flat shape located on the opposite side of the second combustion chamber 122. The end wall surface 129 is surrounded by. That is, the partition wall portion 123 includes a flat surface portion 123a on the outer side and a spherical portion 124 that bulges toward the second combustion chamber 122 on the center side, and the flat surface portion 123a is an end portion. When in contact with the wall surface 129, a space surrounded by the spherical portion 124 and the end wall surface 129 is defined as the first combustion chamber 121. The spherical portion 124 is formed in a substantially hemispherical shape with a substantially equal diameter around the ignition portion 133 of the ignition device 131. In the present embodiment, the first combustion chamber 121 is used as an ignition region for an air-fuel mixture, which will be described later, and the second combustion chamber 122 is used as a region for obtaining a large combustion energy necessary for nailing operation. It is configured.
[0018]
A large number of communication holes 125 are formed in the spherical portion 124 of the partition wall 123 in a perforated shape. The first combustion chamber 121 and the second combustion chamber 122 are in communication with each other through the communication hole 125. The partition wall 123 is fixed to the end of the slide sleeve 127 on the first combustion chamber 121 side via a screw 128 so that the nailing machine 101 can move in the long axis direction integrally with the slide sleeve 127. ing.
[0019]
The second combustion chamber 122 is formed as a space surrounded by the piston 155, the slide sleeve 127, and the partition wall portion 123 that is disposed to face the piston 155 that constitute the drive unit. The top surface of the piston 155 (the surface facing the partition wall portion 123) is a spherical recess 155a formed in a similar shape corresponding to the spherical portion 124 of the partition wall portion 123. The slide sleeve 127 is connected to the contact arm 111 via a pantograph link mechanism 113 indicated by a broken line in the drawing. Although not particularly illustrated, the contact arm 111 is normally biased toward the tip side (left side in FIGS. 1 to 3) by a biasing means such as a spring. For this reason, the slide sleeve 127 is moved to the distal end side together with the partition wall portion 123, and is always in communication with the outside through the extraction hole 104 with the first combustion chamber 121 opened. At this time, the partition wall 123 is brought into contact with the end surface of the cylinder 153 and the top surface of the piston 155 substantially in a surface contact state, and thereby the volume of the second combustion chamber 122 is reduced to zero or close to zero. Is done. This state is the initial state of the nailing machine 101 shown in FIG.
[0020]
On the other hand, when the nailing machine 101 is moved toward the workpiece (not shown) and the contact arm 111 is pressed against the workpiece, the contact arm 111 pressed by the workpiece is biased by the urging means. Moved in the opposite direction against the forces. The backward movement of the contact arm 111 is transmitted to the slide sleeve 127 via the pantograph type link mechanism 113. In the pantograph type link mechanism 113, the link ratio is set so that the amount of movement of the contact arm 111 is amplified several times and transmitted to the slide sleeve 127. For this reason, the slide sleeve 127 and the partition wall portion 123 are moved toward the end wall surface 129, and the peripheral edge portion of the partition wall portion 123 contacts the end wall surface 129. This state is shown in FIG. At this time, the second combustion chamber 122 is closed, and communication with the outside through the extraction hole 104 is cut off. That is, the slide sleeve 127 is a member element constituting the side wall surface of the second combustion chamber 122, and communicates the first combustion chamber 121 with the outside through a sliding operation in the major axis direction of the nailing machine 101. It functions as a combustion chamber opening / closing adjustment means for permitting and regulating. The operation of the slide sleeve 127 during the nailing operation will be described later.
[0021]
The ignition device 131 is configured by an ignition plug, and the ignition unit 133 is disposed at a substantially central portion of the end wall surface 129 of the first combustion chamber 121 so as to be substantially flush with the end wall surface 129. The The ignition device 131 is set to perform an ignition operation within approximately 0.3 seconds after fuel injection by a fuel injection device 141 described later. Further, the discharge is set to be performed a plurality of times during one ignition operation.
[0022]
The fuel injection device 141 constitutes “fuel supply means”, and is mainly composed of a pipe-shaped member 145 that extends from the first combustion chamber 121 through the partition wall 123 to the second combustion chamber 122. The pipe-shaped member 145 has a fuel injection hole 143 formed at a suitable position facing each of the combustion chambers 121 and 122. The fuel injection device 141 is connected to a fuel storage unit (not shown) and receives 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.
[0023]
The pipe-like member 145 constituting the fuel injection device 141 has one end fixed to the end wall surface 129 and extends toward the first and second combustion chambers 121 and 122. A through hole 147 for allowing the pipe-like member 145 to extend into the second combustion chamber 122 is formed at one corner of the spherical portion 124 in the partition wall 123. In the present embodiment, this through hole 147 constitutes an exhaust port for guiding the combustion gas in the second combustion chamber 122 to the first combustion chamber 121.
[0024]
That is, the pipe-shaped member 145 is a stepped pipe in which the base side (fixed end side) is a large diameter portion 145a and the tip side is a small diameter portion 145b. When the flat surface portion 123a of the partition wall portion 123 is brought into contact (contact) with the end wall surface 129, the large-diameter portion 145a is located in (inserted into) the through-hole 147 to close the through-hole 147, The through hole 147 is opened when the small-diameter portion 145b is positioned in the through hole 147 or comes out as the partition wall 123 moves toward the piston 155. Thus, the pipe-shaped member 145 not only constitutes a fuel supply means but also constitutes an on-off valve for opening and closing the through hole 147. Said through-hole 147 respond | corresponds to the "exhaust port" in this invention. Further, the position when the partition wall 123 contacts the end wall surface 129 to form the first combustion chamber 121 having a predetermined volume corresponds to the “position before moving the partition wall” in the present invention.
The through hole 147 has a considerably larger opening area than the communication hole 125. In the present embodiment, the area ratio of the through hole 147 with respect to one communication hole 125 is set to about 20 times in the fully opened state where the small diameter portion 145b is pulled out.
[0025]
The drive unit 151 mainly includes a cylinder 153 housed 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. Although not particularly shown, the distal end side of the piston rod 157 is disposed 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 161 for communicating the inside of the bore of the cylinder 153 with the outside of the nailing machine 101. The check valve 161 is configured as a one-way valve that allows the fluid in the bore of the cylinder 153 to flow out while restricting the flow of the external fluid into the bore of the cylinder 153.
[0026]
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 can slide relative to the injection unit 110 in the long axis direction of the injection unit 110 (that is, the long axis direction of the nail driver 101 and corresponds to the left-right direction in FIG. 1). It is normally biased toward the tip side (left side in FIG. 1) by the biasing means. The urging means also serves as the urging means of the slide sleeve 127 described above.
[0027]
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 slide sleeve 127 is moved to the tip side by the biasing force of the biasing means, the first combustion chamber 121 is in communication with the outside, and the partition wall 123 is in contact with the cylinder 153 and the piston 155. The volume of the second combustion chamber 122 is reduced to zero or close to zero. At this time, the pipe-shaped member 145 is pulled out from the through hole 147 of the partition wall 123, and the through hole 147 is opened.
[0028]
In order to perform the nail driving operation using the nail driver 101 in such a state, the contact arm 111 is first brought into contact with the work material, and then the operator applies a pressing force in the direction of the work material. To act on. Then, the contact arm 111 moves backward to the side away from the workpiece while resisting the biasing force by the biasing means. As the contact arm 111 moves backward, the slide sleeve 127 connected to the contact arm 111 via the pantograph link mechanism 113 moves backward by a stroke amount several times that of the contact arm 111. By this retreating operation, the partition wall 123 moves toward the end wall surface 129, and the flat surface 123 a comes into contact with the end wall surface 129 and blocks communication with the outside of the first combustion chamber 121. As a result, as shown in FIG. 2, the volume of the first combustion chamber 121 and the volume of the second combustion chamber 122 are set to a predetermined volume ratio. At this time, the large-diameter portion 145a of the pipe-shaped member 145 is fitted into the through-hole 147 of the partition wall 123, and the through-hole 147 is closed.
[0029]
In this state, when the operator pulls and operates the trigger 107 provided on the hand grip 105, the fuel is injected into the combustion chambers 121 and 122 from the fuel injection holes 143a and 143b (see FIG. 2) provided in the fuel injection device 141. Is injected. 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. The air-fuel mixture corresponds to “combustible gas” in the present invention.
[0030]
In the present embodiment, the ignition device 131 provided in the first combustion chamber 121 is used after a predetermined time has elapsed since the fuel was injected into the first and second combustion chambers 121, 122, for example, approximately 0.3 seconds later. An ignition operation is performed. Further, the ignition device 131 is preferably discharged a plurality of times from the ignition unit 133 in one ignition operation. As a result, the ignition / combustion operation in the first combustion chamber 121 is realized smoothly and with high efficiency.
[0031]
When an ignition operation is performed by the ignition device 131, the air-fuel mixture filled in the first combustion chamber 121 is ignited from the region near the ignition unit 133, and combustion of the air-fuel mixture in the first combustion chamber 121 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, since the partition wall portion 123 is configured as a spherical portion 124 having a substantially equal diameter centered on the ignition portion 133, the combustion surface of the air-fuel mixture emitted from the ignition portion 133 The spherical portion 124 having the same radius with respect to the ignition portion 133 is reached almost simultaneously. For this reason, it is possible to unify the ignition timing of the second combustion chamber 122 by the respective communication holes 125 over the entire boundary surface of the partition wall portion 123, and the combustion start timing in the second combustion chamber 122 is effective. It is possible to control.
[0032]
The air-fuel mixture filled in the second combustion chamber 122 is ignited simultaneously from the entire surface area of the partition wall 123, 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. As a result, as shown in FIG. 3, the piston 155 is slidably moved (moved forward) in the cylinder 153 toward the workpiece.
In addition, 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 is as shown in FIG. Since it is discharged to the outside through the check valve 161, the sliding operation of the piston 155 is not hindered.
[0033]
As the piston 155 slides 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 unit 110 moves toward the work material side at a 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.
[0034]
At the stage where the nail driving operation is completed, a cooling action is generated in the expanded first and second combustion chambers 121 and 122 due to the sliding movement of the piston 155, whereby the piston 155 is removed from the workpiece. The backward movement is automatically started toward the separating side. In addition, by releasing the pressure load on the nailing machine that the operator has acted in the direction of the workpiece, the contact arm 111 that has moved backward relative to the main housing 103 side causes the biasing force of the biasing means to be applied. To move in the tip direction (workpiece direction). As the contact arm 111 moves, the slide sleeve 127 and the partition wall 123 move in the distal direction (piston 155 side). As a result, as shown in FIG. 4, the first combustion chamber 121 is opened, and the first combustion chamber 121 communicates with the outside of the nailing machine 101 through the bleed holes 104 formed in the main housing 103.
[0035]
The movement of the partition wall 123 in the distal direction is governed by the release time of the operator's pressing load in the direction of the workpiece against the nailing machine. This 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 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 in the direction of the workpiece of the nailing machine, the piston 155 completes the retreating operation and moves forward before the moving operation of the partition wall 123 starts. It will return to the initial position before starting the operation.
[0036]
The volume reduction operation of the second combustion chamber 122 is started by the retreating operation of the piston 155 as described above and the moving operation of the partition wall portion 123 toward the front end direction (side toward the piston 155). Then, as shown in FIG. 4, the extraction hole 104 is opened by the movement of the partition wall portion 123 in the distal direction, and the first combustion chamber 121 is communicated with the outside. On the other hand, as shown in FIG. 5, the through-hole 147 is separated from the large-diameter portion 145a of the pipe-shaped member 145 and corresponds to the small-diameter portion 145b, thereby opening the through-hole 147. For this reason, a gas flow from the through hole 147 toward the extraction hole 104 is generated in the first combustion chamber 121. Accordingly, the combustion gas in the second combustion chamber 122 is guided to the first combustion chamber 121 side through the through-hole 147 and is exhausted to the outside through the extraction hole 104 together with the combustion gas in the first combustion chamber 121.
[0037]
A number of communication holes 125 are formed in the partition wall portion 123. Therefore, the combustion gas in the second combustion chamber 122 flows to the first combustion chamber 121 through the communication hole 125. However, the flow is directed toward the center of the combustion chamber (the communication hole 125 penetrates toward the ignition unit 133), and each opening cross-sectional area of the communication hole 125 has an opening cut-off of the through hole 147. It is extremely small compared to the area, and its flow rate is small compared to the flow rate flowing from the through hole 147. For this reason, in the first combustion chamber 121, a flow toward the extraction hole 104 through the through hole 147 is formed as a main gas flow.
The partition wall portion 123 moves to a position where it comes into contact with the piston 155, whereby the volume of the second combustion chamber 122 is reduced to a zero state or a state close to zero. At this point, the small-diameter portion 145b of the pipe-shaped member 145 is completely removed from the through hole 147, and the through hole 147 is fully opened. Thus, the nailing machine 101 returns to the initial state shown in FIG.
[0038]
When exhausting the combustion gas, according to the present embodiment, in the nailing machine 101 of the type in which the combustion chamber is constituted by the first and second combustion chambers 121 and 122, the piston 155 and the partition wall 123 move, The configuration is such that the combustion gas is discharged by reducing the volume of the second combustion chamber 122 which is one of the combustion chambers. Therefore, the combustion gas in the second combustion chamber 122 is pushed out from the through hole 147 to the first combustion chamber 121 with the movement of the piston 155 and the partition wall 123. Thereby, momentum is given to the flow of the combustion gas flowing out to the first combustion chamber 121.
[0039]
On the other hand, a gas flow is formed in the first combustion chamber 121 with the through hole 147 as the inlet and the bleed port 104 as the outlet as described above. That is, a gas flow from the second combustion chamber 122 to the first combustion chamber 121 is formed, and the combustion gas in the second combustion chamber 122 is discharged to the outside together with the combustion gas in the first combustion chamber 121 by this gas flow. In the present embodiment, a through hole 147 is formed at one corner of the spherical portion 124 in the partition wall portion 123 and is arranged on the opposite side of the extraction hole 104 across the axis of the first combustion chamber 121. For this reason, in the first combustion chamber 121, as shown by an arrow in FIG. 1, the combustion gas introduced into the first combustion chamber 121 through the through hole 147 passes through the central portion of the first combustion chamber 121. A flow is formed across to the bleed hole 104. That is, an inclined gas flow from one end to the other end is formed in the first combustion chamber 121. With this gas flow, the combustion gas introduced from the second combustion chamber 122 to the first combustion chamber 121 and the combustion gas in the first combustion chamber 121 are smoothly discharged to the outside through the extraction port 104.
[0040]
Thus, according to the present embodiment, it is possible to efficiently discharge combustion gas while having a simple structure that reduces the volume of one of the two combustion chambers. In the present embodiment, the pipe-shaped member 145 has a function of opening and closing the exhaust through-hole 147, that is, a function of an on-off valve, in addition to the original function of the fuel injection device 141. For this reason, it is possible to reduce the number of parts and simplify the structure.
[0041]
In the present embodiment, the partition wall portion 123 is integrally attached to the slide sleeve 127 and moves with the slide sleeve 127. Further, the opposing surfaces of the partition wall portion 123 and the piston 155 have a similar shape, and the volume of the second combustion chamber 122 is reduced to zero or close to zero when the combustion chamber is open. After combustion of the combustible gas, the combustion gas in the second combustion chamber 122 is released to the atmosphere via the through hole 147 of the partition wall portion 123 by the movement of the slide sleeve 127 and the partition wall portion 123. With this configuration, the combustion gas can be rationally discharged through a small number of moving members.
[0042]
In the present embodiment, the through-hole 147 formed in the partition wall portion 123 is configured to be opened and closed by the pipe-shaped member 145 constituting the fuel injection device 141, but a member different from the pipe-shaped member 147 is used. Thus, the configuration may be changed so that the through hole 147 is opened and closed. In that case, either the structure which inserts in the through-hole 147 and closes the said through-hole 147, or the structure which closes the said through-hole 147 by contacting the partition part 123 per surface may be sufficient.
The bleed hole 104 is formed in the side wall portion of the main housing 103 and is opened and closed by the slide sleeve 127. For example, the bleed hole 104 is formed in the end wall surface 129, and the bleed hole 104 is formed in the partition wall. You may change to the structure opened and closed by the flat surface part 123a of the part 123. FIG.
[0043]
Further, when the combustion gas in the second combustion chamber 122 is led to the first combustion chamber 121 by reducing the volume of the second combustion chamber 122, as a means for forming a gas flow in the first combustion chamber 121, for example, When a movable gas guide plate is arranged in one combustion chamber and the partition wall portion 123 moves in a direction to reduce the volume of the second combustion chamber 122, the first combustion chamber 121 is displaced by displacing the gas guide plate in an inclined manner. The combustion gas introduced into the inside may be guided to the extraction hole 104. If such a configuration is adopted, the through hole 147 can be eliminated.
[0044]
In the present embodiment, since the piston 155 is moved backward by the suction force generated in the first and second combustion chambers 121 and 122, the movement of the partition wall portion 123 is completed after the piston 155 finishes the backward movement. Will be configured to start. However, if the piston 155 is configured to be forcibly retracted using a means other than the suction force, the movement start timing of the partition wall portion 123 is not particularly problematic. That is, there is no problem even if the movement of the partition wall 123 and the piston 155 is performed simultaneously.
[0045]
In view of the gist of the present invention, the following various aspects can be configured.
(Aspect 1)
"The combustion type work tool according to any one of claims 1 to 5,
The partition is integrated with a slide sleeve that is moved to open and close a bleed hole that allows the first combustion chamber to communicate with the outside, and is moved together with the slide sleeve. Work tools. "
According to this aspect 1, the operation of reducing the volume of the second combustion chamber by the partition wall portion can be performed using the moving operation of the slide sleeve. That is, it is not necessary to configure a separate operation system, which is effective for simplifying the mechanism.
[0046]
(Aspect 2)
"The combustion type work tool according to any one of claims 1 to 5,
A spherical portion that bulges toward the surface facing the piston side is formed in the central portion of the partition wall, and a spherical concave portion corresponding to the spherical portion is formed on the piston top surface. Combustion-type work tool characterized by "
According to this aspect 2, when the piston and the partition wall are moved in the direction of decreasing the volume of the second combustion chamber, the opposing surface is formed in a similar shape, so that the volume of the second combustion chamber is reduced to zero. Or can be reduced to zero.
[0047]
(Aspect 3)
The work tool according to claim 3,
The exhaust port of the partition wall is closed by a large-diameter portion formed in a pipe-like member for supplying a combustible gas that is disposed through the exhaust port, and the volume of the second combustion chamber of the partition wall A combustion working tool characterized by being configured to be spaced apart from the large-diameter portion and opened based on movement in a direction to reduce the amount. "
That is, in the aspect 3, the exhaust port is opened and closed by using the partition wall portion that moves to reduce the volume of the second combustion chamber and the pipe-shaped member that is provided for supplying the combustion chamber with the combustible gas. According to such a configuration, there is no need to set an opening / closing member as a separate part, which is effective in simplifying the structure.
[0048]
【The invention's effect】
According to the present invention, a technique capable of rationally performing exhaust of combustion gas in a combustion-type work tool while having a simple structure is provided.
[Brief description of the drawings]
BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a partial cross-sectional view in front view showing the overall configuration of a nailing machine according to an embodiment, showing an initial state.
FIG. 2 is a partial cross-sectional view in front view showing the overall configuration of the nailing machine, showing ignition.
FIG. 3 is a partial cross-sectional view in front view showing the overall configuration of the nailing machine, showing an explosion.
FIG. 4 is a partial cross-sectional view showing an intermediate state from an explosion to an initial state.
FIG. 5 is an enlarged view showing an opening mode of a through hole of a partition wall by a pipe-like member.
[Explanation of symbols]
101 Nail driver (combustion work tool)
103 Main housing
104 extraction holes
105 hand grip
107 trigger
109 magazine
110 Injection unit
111 Contact arm (operating means)
113 Pantograph type link mechanism
121 1st combustion chamber
122 Second combustion chamber
123 Bulkhead
123a Flat surface part
124 Spherical part
125 communication hole
127 slide sleeve
128 screws
129 End wall
131 Ignition system
133 Ignition part
141 Fuel injector
143 Fuel injection hole
145 Pipe-shaped member
145a Large diameter part
145b Small diameter part
147 Through hole (exhaust port)
151 Drive unit
153 cylinder
155 piston
155a Spherical concave
157 Piston rod
159 cushion rubber
161 Check valve

Claims (5)

First and second combustion chambers filled with combustible gas;
An ignition device provided in the first combustion chamber;
A partition wall partitioning the first and second combustion chambers;
A communication hole disposed in the partition wall to communicate the first combustion chamber and the second combustion chamber;
The combustible gas in the first combustion chamber is combusted via the ignition device, and the combustion surface of the combustible gas in the first combustion chamber is propagated to the second combustion chamber through the communication hole of the partition wall. A combustible gas in the second combustion chamber, and a drive unit that performs a predetermined processing operation by using the combustion pressure generated thereby,
Combustion gas after combustion in the second combustion chamber is guided to the first combustion chamber by moving the partition wall toward the second combustion chamber and reducing the volume of the second combustion chamber. A combustion type work tool characterized by being discharged to the outside together with the combustion gas in the first combustion chamber. It is a combustion type work tool according to claim 1,
The volume reduction of the second combustion chamber is performed by a movement operation in the direction in which the partition portion and the piston disposed opposite to each other with the partition portion sandwiched between the second combustion chambers in directions close to each other. Combustion type work tool characterized by that. It is a combustion type work tool according to claim 1 or 2,
The partition wall is formed with an exhaust port that guides the combustion gas in the second combustion chamber to the first combustion chamber, and the exhaust port reduces the volume of the second combustion chamber of the partition wall. A combustion type work tool characterized in that it is opened by movement in a direction to close and closed at an initial position before movement of the partition wall. It is a combustion type work tool according to claim 1,
The combustion gas guided to the first combustion chamber is discharged to the outside together with the combustion gas in the first combustion chamber by a gas flow in a predetermined direction formed in the first combustion chamber. Combustion work tool. It is a combustion type work tool in any one of Claims 1-4,
Combustion-type operation characterized in that the combustion gas guided to the first combustion chamber flows in an inclined manner from one corner to the other corner in the first combustion chamber. tool.

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