JP7183543B2 - driving tool - Google Patents

Description

The present invention relates to driving tools.

Conventionally, driving tools that utilize a mixture of fuel and air have been widely used. In this type of driving tool, after creating a mixture of fuel and air in the combustion chamber, the mixture is ignited and burned to generate high combustion pressure, which drives the piston in the cylinder and is supplied to the nose. The nail is driven out by striking with a driver integrally formed with the piston.

In a typical driving tool, some exhaust gas remains in the combustion chamber after the driving operation. If the next driving operation is performed while the exhaust gas remains in the combustion chamber, there is a problem that the next driving output and the ignition performance of the mixture in the combustion chamber are lowered. Therefore, scavenging is conventionally performed to exhaust the exhaust gas in the combustion chamber to the outside after the driving operation.

For example, U.S. Pat. No. 6,200,000 discloses that as the piston/driver moves, some of the air below the piston/driver is used to actuate an exhaust valve, thereby producing combustion products (exhaust gas) from the combustion chamber. ) is disclosed to the atmosphere.

JP-A-63-28574

However, in the driving tool described in Patent Document 1, it is assumed that scavenging is performed when the piston returns. In such a case, since the movement of the piston is hindered by the air blown to the piston, the return of the piston may be delayed or the piston may not be able to return to its initial position. As a result, there is a problem that the piston becomes an obstacle, making it impossible to supply new nails, or that the next driving operation cannot be stably carried out.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made in view of the above problems, and an object of the present invention is to provide a driving tool that uses fuel and air to perform a stable driving operation by reliably scavenging air. to provide the tools.

A driving tool according to the present invention movably accommodates a combustion chamber to which fuel and compressed air are supplied, and a piston driven by combustion pressure when a mixture of fuel and compressed air filled in the combustion chamber is ignited. a valve for opening and closing a path for supplying compressed air to the combustion chamber; a trigger for activating an ignition device for burning a mixture of fuel and compressed air filled in the combustion chamber; a contact member that makes contact with the driving member to activate the operation of the trigger; and a control unit that controls the valve, wherein the control unit supplies compressed air to the combustion chamber after the contact member is turned on. The valve is controlled to stop the supply of compressed air after a predetermined time has elapsed from the start of supply , and the mixture of compressed air and fuel supplied to the combustion chamber is burned. The valve is controlled to supply compressed air as scavenging air to the combustion chamber after exhaustion from the chamber is started and when it is determined that the return of the piston is completed.

Further, the driving tool according to the present invention can move a combustion chamber to which fuel and compressed air are supplied, and a piston driven by combustion pressure when a mixture of fuel and compressed air filled in the combustion chamber is ignited. a cylinder housed in the combustion chamber, a valve for opening and closing a path for supplying compressed air to the combustion chamber, a fuel injection valve for opening and closing a path for supplying fuel to the combustion chamber, and a trigger that activates an ignition device to burn a mixture of fuel and compressed air; a contact member that contacts the driven member to effect operation of the trigger; and controls the valve and the fuel injection valve. a control unit, wherein the control unit controls the fuel injection valve so as to supply the fuel to the combustion chamber when the contact member is turned on, and the trigger is activated after the contact member is turned on. When it is determined that the contact member is turned off without being turned on, the valve is controlled so as to supply compressed air as scavenging air to the combustion chamber after the exhaust from the combustion chamber is started.

According to the present invention, since the combustion chamber is scavenged after the driving operation is completed, the return failure of the piston can be prevented, and the driving operation can be stabilized.

1 is a perspective view of a driving tool according to one embodiment of the present invention; FIG. It is a sectional view of a driving tool. It is a block diagram which shows an example of the functional structure of a driving tool. It is a flowchart which shows the driving operation|movement in a driving tool. It is a timing chart of each device at the time of driving operation of the driving tool (No. 1). 2 is a timing chart of each device during the driving operation of the driving tool (No. 2); 3 is a timing chart of each device during the driving operation of the driving tool (No. 3); FIG. 9 is a timing chart for explaining the scavenging operation of the driving tool according to the second embodiment of the present invention; FIG. It is a flow chart which shows other scavenging operation in a driving tool (part 1). 2 is a flow chart showing another scavenging operation in the driving tool (No. 2). 3 is a flowchart showing another scavenging operation in the driving tool (No. 3). It is a flowchart which shows the operation|movement at the time of abnormality detection of the driving tool which concerns on the 3rd Embodiment of this invention.

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Note that the dimensional ratios in the drawings are expanded for convenience of explanation and may differ from the actual ratios.

<First embodiment>
[Configuration example of driving tool 10]
1 and 2 show an example of the configuration of a driving tool 10 according to one embodiment of the present invention. 1 and 2, the driving direction of the nail is downward, and the opposite side is upward. 1 and 2, the tool body 12 side is the front side, the battery 70 side is the rear side, the contact arm 52 side is the bottom side, and the cylinder head 30 side is the top side. In addition, in the direction orthogonal to the front-rear direction and the vertical direction of the driving tool 10 , the right side of the driving tool 10 is defined as the right side of the driving tool 10 and the left side thereof is defined as the left side of the driving tool 10 with respect to the front direction.

As shown in FIGS. 1 and 2, a driving tool 10 is a tool for driving fasteners such as nails, staples, pins, etc. into a workpiece such as wood, gypsum board, steel plate, concrete, etc. , a nose 50 , a contact arm 52 , a grip 60 , a trigger 62 , a battery loading section 68 , a gas cartridge storage section 64 and a magazine 54 .

The tool body 12 is formed in an elongated, substantially cylindrical shape, and the tool body 12 accommodates a driving mechanism 20 for driving.

The drive mechanism 20 has a cylinder 22 , a head valve 24 , a sleeve 26 , a spring 28 , a cylinder head 30 , a piston 34 and a driver 36 .

The cylinder 22 has a cylindrical shape with a smaller diameter than the tool body 12 and is arranged inside the tool body 12 . A combustion chamber 32 filled with fuel and compressed air is provided on the upper side within the cylinder 22 . The combustion chamber 32 is a space defined by the inner peripheral surface of the cylinder 22 , the outer peripheral surface of the sleeve 26 and the lower surface of the sleeve 26 .

The piston 34 is located in an initial position inside the cylinder 22 and below the sleeve 26 and is subject to the combustion pressure created when the mixture of fuel and compressed air that fills the combustion chamber 32 is ignited. The cylinder 22 is made slidable in the vertical direction. Here, the initial position of the piston 34 is the position where the piston 34 contacts the lower surface of the sleeve 26 in the cylinder 22, and the piston 34 moves inside the cylinder 22 due to the combustion pressure when the mixture in the combustion chamber 32 is ignited. This is the stop position before moving downwards. The driver 36 is formed integrally with the lower end of the piston 34, and moves the nose 50 as the piston 34 moves to drive the nail supplied from the magazine 54 into the nailed member.

The sleeve 26 is formed of a cylindrical body and arranged within the combustion chamber 32 . The bottom surface of the sleeve 26 is provided with a first opening 26a that communicates with the upper space of the piston 34 . A second opening 26b is provided at the lower end of the cylindrical portion of the sleeve 26 to communicate the combustion chamber 32 and the first opening 26a.

The head valve 24 is composed of a cylindrical body with an open upper end and a closed lower end, and is arranged inside the sleeve 26 and above the piston 34 . Sealing members 38 and 39 for sealing a gap with respect to the sleeve 26 are provided respectively at the upper and lower portions of the outer periphery of the head valve 24 . The seal member 38 radially protrudes more than the seal member 39 . The head valve 24 is configured to be vertically movable within the sleeve 26 by combustion pressure when the mixture is combusted in the combustion chamber 32. Combustion pressure can flow from the inside into the cylinder 22 in which the piston 34 is arranged.

The spring 28 comprises a compression spring and is arranged inside the head valve 24 and coaxially with the driver 36 . The spring 28 has its upper end in contact with the cylinder head 30 and its lower end in contact with the bottom surface of the head valve 24 to urge the head valve 24 downward.

The cylinder head 30 is attached to the upper end of the cylinder 22 so as to block the upper end opening of the combustion chamber 32 . The cylinder head 30 is provided with a fuel injection port (not shown) for injecting fuel into the combustion chamber 32 and an air injection port (not shown) for injecting compressed air into the combustion chamber 32. ing.

The fuel injection valve 130 opens and closes the flow path of the fuel hose 132 and controls the amount of fuel supplied to the combustion chamber 32 . The fuel injection valve 130 is installed in the middle of the fuel hose 132 and arranged on the upper rear side of the cylinder 22 . One end of the fuel hose 132 is connected to the fuel injection port of the cylinder head 30 and the other end of the fuel hose 132 is connected to the gas cartridge storage section 64 .

The air injection valve 140 opens and closes the passage of the air hose 142 and controls the amount of compressed air supplied to the combustion chamber 32 . The air injection valve 140 is installed in the middle of the air hose 142 and arranged in parallel on the upper rear side of the cylinder 22 and on the left side of the fuel injection valve 130 in FIG. By arranging the air injection valve 140 in parallel with the fuel injection valve 130, the overall size of the driving tool 10 can be reduced. Moreover, when holding the grip 60, it does not become an obstacle. Further, since the fuel injection valve 130 and the air injection valve 140 are arranged near the combustion chamber 32 above the cylinder 22, the response when filling the combustion chamber 32 with fuel or compressed air is good. One end of the air hose 142 is connected to the air injection port of the cylinder head 30 and the other end of the air hose 142 is connected to the air plug 144 . The air plug 144 is connected to, for example, an air compressor or an air tank storing compressed air, so that compressed air can be taken into the combustion chamber 32 from the outside of the driving tool 10 .

The nose 50 is formed integrally with the lower end of the tool body 12 . At the center of the nose 50 is provided an injection port 51 that extends vertically and communicates with the inside of the cylinder 22 . The injection port 51 guides the driver 36 (piston 34) along the vertical direction.

The contact arm 52 is attached to the outer peripheral portion of the distal end of the nose 50 and is configured to be movable upward relative to the nose 50 when pressed against a member to be driven. When the contact arm 52 moves to a predetermined position by pressing, the operation of the trigger 62 becomes effective.

The grip 60 has a substantially columnar shape that is easy for the operator to grip, and extends rearward from a substantially central side surface in the vertical direction (longitudinal direction) of the tool body 12 . A battery mounting portion 68 is provided at the rear end portion of the grip 60 . A battery 70 is detachably attached to the battery mounting portion 68 . As the battery 70, for example, a battery containing a secondary battery such as a lithium battery with a voltage of 14.4V can be used.

The trigger 62 is a part for the operator to operate the nail driving operation, and is provided on the front lower surface side of the grip 60 so as to protrude toward the magazine 54 side.

The gas cartridge housing portion 64 is disposed between the grip 60 and the magazine 54 and extends substantially parallel to the grip 60 from the side portion of the tool body 12 . A gas can is detachably attached to the gas cartridge housing portion 64 .

The magazine 54 is attached to the rear side of the nose 50 and is configured so that a plurality of nails can be loaded therein. The magazine 54 communicates with the ejection port 51 of the nose 50 and is configured to supply nails to the nose 50 .

[Block diagram of driving tool 10]
FIG. 3 is a block diagram showing an example of the functional configuration of the driving tool 10 according to the present invention. As shown in FIG. 3, the driving tool 10 has a control section 100 for controlling the operation of the entire tool. The control unit 100 has a CPU, ROM and RAM. The CPU expands the program stored in the ROM into the RAM and executes it, thereby realizing a predetermined driving operation including control of injection timing of fuel and compressed air. More specifically, the control unit 100 starts fuel injection when the contact switch 110 is turned on by pressing the contact arm 52 against the driven member, and the trigger switch 112 is turned on by operating the trigger 62. After that, control is executed to complete the injection of compressed air.

The control unit 100 includes a contact switch 110, a trigger switch 112, a gas can detection switch 114, a temperature sensor 116, pressure sensors 118 and 120, a fuel injection valve 130, an air injection valve 140, an ignition plug 150, and the control unit 100. Each of the batteries 70 that supply power are connected. If the temperature sensor 116 and the pressure sensors 118 and 120 are not used, the driving tool 10 can be configured without these.

The contact switch 110 is connected to the contact arm 52 via a link member, and is turned on when the contact arm 52 is pressed against the member to be driven and moved to a predetermined position with respect to the nose 50, and the contact arm 52 is turned on. to the control unit 100.

The trigger switch 112 is provided in the vicinity of the trigger 62 , turns on when the operator pulls the trigger 62 , and outputs an on signal indicating that the trigger 62 has been turned on to the control unit 100 .

The gas can detection switch 114 is provided on the inlet side of the gas cartridge housing portion 64, and is turned on when the gas canister is attached to the gas cartridge housing portion 64, and an on signal indicating that the gas canister is attached is sent to the control portion 100. output to

The temperature sensor 116 is installed, for example, in the combustion chamber 32 or in the vicinity of the combustion chamber 32 . The temperature sensor 116 detects the mechanical temperature inside the tool body 12 and the environmental temperature around the driving tool 10 and outputs the temperature information to the control unit 100 .

The pressure sensor 118 is installed, for example, on an air hose 142 extending between the air plug 144 and the air injection valve 140 . The pressure sensor 118 detects whether or not an air source such as a compressor is connected to the air plug 144, and detects whether or not there is an abnormality in the air pressure supplied from the air source such as a compressor. is supplied to the control unit 100 .

The pressure sensor 120 is installed, for example, in the combustion chamber 32 or in an air hose 142 extending between the combustion chamber 32 and the air injection valve 140 . Pressure sensor 120 detects an abnormality in the air filling pressure in combustion chamber 32 and supplies information about the detected pressure to control unit 100 . A check valve (not shown) may be provided between the combustion chamber 32 and the pressure sensor 120 .

The fuel injection valve 130 operates (opens and closes) based on a drive signal supplied from the control unit 100 to supply the fuel filled in the metering chamber inside the valve into the combustion chamber 32 .

Air injection valve 140 operates (opens and closes) based on a drive signal supplied from control unit 100 to inject a predetermined amount of compressed air into combustion chamber 32 .

An ignition device switch 152 of the igniter unit is turned on based on a control signal supplied from the control unit 100 to ignite the ignition plug 150 to burn the mixture filled in the combustion chamber 32 .

[Example of Operation of Driving Tool 10]
FIG. 4 is a flow chart showing an example of the operation of the control section 100 when driving the driving tool 10 according to the present invention.

As shown in FIG. 4, in step S100, the control unit 100 determines whether or not the trigger switch 112 is turned off and the contact switch 110 is turned on by pressing the contact arm 52 against the driven member. When the contact switch 110 and the trigger switch 112 are off, the control unit 100 continuously monitors the states of the contact switch 110 and the like. On the other hand, when control unit 100 determines that trigger switch 112 is off and contact switch 110 is on, the process proceeds to step S110.

In step S110, the control unit 100 outputs an ON signal to the fuel injection valve 130 to operate and open the fuel injection valve 130, and closes the fuel injection valve 130 after a predetermined time has elapsed. As a result, a predetermined amount of fuel is injected into the combustion chamber 32 . After step S110 ends, the process proceeds to step S120.

In step S120, the control unit 100 determines whether the contact switch 110 is turned off by the contact arm 52 leaving the workpiece, that is, whether the contact switch 110 is on. If the contact switch 110 continues to be on, the controller 100 proceeds to step S130. On the other hand, when the contact switch 110 is turned off, the controller 100 proceeds to step S170.

In step S130, control unit 100 determines whether both contact switch 110 and trigger switch 112 are on. If the control unit 100 determines that at least one of the contact switch 110 and the trigger switch 112 is off, the process returns to step S120. On the other hand, when the control unit 100 determines that both the contact switch 110 and the trigger switch 112 are on, the process proceeds to step S140.

In step S140, control unit 100 outputs an ON signal to air injection valve 140 to operate air injection valve 140 to open it, and close fuel injection valve 130 after a predetermined time has elapsed. As a result, a predetermined amount of compressed air is injected into the combustion chamber 32, and the inside of the combustion chamber 32 is agitated by the injection of the compressed air, thereby generating a mixture of fuel and compressed air. In this embodiment, the fuel and the compressed air are injected into the combustion chamber 32 in that order, so the fuel and the compressed air are evenly mixed within the combustion chamber 32 . As a result, the unevenness of the mixture ratio in the combustion chamber 32 is eliminated, so that the occurrence of abnormal combustion can be prevented. After step S140 ends, the process proceeds to step S150.

In step S150, control unit 100 further determines whether both contact switch 110 and trigger switch 112 are on before igniting the mixture. When the control unit 100 determines that both the contact switch 110 and the trigger switch 112 are not on, the process proceeds to step S170. In step S180, the control unit 100 performs scavenging for discharging the fuel and mixture remaining in the combustion chamber 32 to the outside, as described above.

On the other hand, when the control unit 100 determines that both the contact switch 110 and the trigger switch 112 are on, the process proceeds to step S160.

In step S160, the control unit 100 activates the ignition device switch 152 to cause the ignition plug 150 to spark and burn the mixture filled in the combustion chamber 32. As shown in FIG. As a result, the head valve 24 opens, and the combustion pressure flowing from the combustion chamber 32 causes the piston 34 to reciprocate within the cylinder 22, thereby performing the driving operation. After step S160 ends, the process proceeds to step S170.

In step S170, the control unit 100 detects the return of the piston 34 when the contact switch 110 is off, detects the return of the piston 34 when the contact switch 110 and the trigger switch 112 are off, or detects the return when the trigger switch 112 is off. or not. The return of the piston 34 can be determined, for example, by whether a predetermined time has elapsed since the trigger 62 was turned on, or whether a predetermined time has elapsed since the spark signal was output to the ignition device switch 152, or the like. The control unit 100 monitors until one of these conditions is satisfied.

On the other hand, when the control unit 100 determines that the contact switch 110 is off and the piston 34 has returned to the initial position, the process proceeds to step S180. In step S180, the control unit 100 executes scavenging for discharging the fuel (mixture) remaining in the combustion chamber 32 and the exhaust gas after combustion from the combustion chamber 32 to the outside. In this embodiment, such processing is repeatedly executed. Note that if step S180 (scavenging) is performed after a predetermined period of time without immediately executing step S180 after the condition of step S170 is satisfied, the fuel and exhaust gas remaining in the combustion chamber 32 before the start of scavenging will is discharged to some extent, and the consumption of air used for scavenging can be suppressed.

[Timing chart during operation of driving tool 10]
FIG. 5 shows an example of a timing chart in each device during the driving operation of the driving tool 10 according to the present invention.

As shown in FIG. 5, when the operator attaches the gas can 66 to the gas cartridge housing portion 64 at time t1, the gas can detection switch 114 switches from high level to low level, turning the gas can detection switch 114 on. do.

At time t2, when the contact arm 52 is pushed into the workpiece by the operator, the contact arm 52 moves upward relative to the nose 50, and the contact switch 110 switches from high level to low level. Contact switch 110 is turned on.

When the contact arm 52 is continuously turned on during the period p1, the drive signal output to the fuel injection valve 130 switches from low level to high level at time t3. As a result, the fuel injection valve 130 is opened, and fuel is injected into the combustion chamber 32 from the fuel injection port of the cylinder head 30 for the injection time calculated in advance.

At time t4, the drive signal supplied to fuel injection valve 130 switches from high level to low level. As a result, the fuel injection valve 130 is closed, and the injection of fuel into the combustion chamber 32 from the fuel injection port of the cylinder head 30 is stopped.

At time t5, when the operator pulls the trigger 62 while the contact arm 52 is on, the trigger switch 112 is switched from high level to low level, and the trigger switch 112 is turned on.

When both the contact switch 110 and the trigger switch 112 are continuously turned on during the period p2, the drive signal supplied to the air injection valve 140 switches from low level to high level at time t6. As a result, the air injection valve 140 is opened, and compressed air is injected into the combustion chamber 32 from the air injection port of the cylinder head 30 for an injection time corresponding to the set output energy. It should be noted that the output energy can be selected from weak, medium, and strong levels by a switch provided near the battery mounting portion 68 .

At time t7, the drive signal supplied to the ignition device switch 152 switches from high level to low level, and voltage boosting to the spark plug 150 is started. At time t9, the boost to the discharge voltage of the ignition plug 150 is completed, and the mixture in the combustion chamber 32 is ignited. The timing of ignition is set in consideration of the time required for the voltage to rise to the discharge voltage of the spark plug 150, and is set so that the mixture in the combustion chamber 32 can be ignited immediately after the injection of the compressed air ends, and the driving operation can be started. be.

At time t8, when a preset air injection time has elapsed, the drive signal supplied to air injection valve 140 switches from high level to low level. As a result, the air injection valve 140 is closed, and the injection of compressed air into the combustion chamber 32 from the air injection port of the cylinder head 30 is stopped.

At time t9, the mixture in combustion chamber 32 ignites. As a result, the mixture in the combustion chamber 32 is combusted immediately after the injection of compressed air is completed, and the head valve 24 is opened by the combustion pressure generated during the combustion, and the combustion pressure flows into the cylinder 22, causing the piston 34 to move into the cylinder. A driving action is performed by moving downward in 22 .

At time t10, when driving the nail into the driven member is completed and the operator's finger is released from the trigger 62, the trigger switch 112 switches from low level to high level, and the trigger switch 112 is turned off.

At time t11, when the contact arm 52 moves away from the driven member and returns to the initial position (the position where the tip protrudes from the nose 50), the contact switch 110 switches from low level to high level, and the contact switch 110 is turned off. .

At time t12 after contact switch 110 is turned off, the drive signal supplied to air injection valve 140 switches from low level to high level. As a result, the air injection valve 140 opens, and compressed air is injected into the combustion chamber 32 from the air injection port of the cylinder head 30 for a preset injection time, thereby exhausting the exhaust gas in the combustion chamber 32. Scavenging is performed. The scavenging is preferably performed after the return of the piston 34 is completed and stopped at the initial position so as not to affect the return operation of the piston 34 . The scavenging that injects compressed air may interfere with the return operation of the piston 34, but if the return of the piston 34 is reliably completed, the return of the piston 34 will not be affected. Further, after the return of the piston 34 is completed, the volume to be scavenged with the exhaust gas is reduced. Therefore, the time required for scavenging and the amount of ejected compressed air can be reduced. Furthermore, the smaller volume to be scavenged can also reduce the likelihood of residual exhaust gases, thereby reducing the impact of exhaust gases on subsequent driving operations.

Note that scavenging can be performed at timings other than those described above. For example, when the temperature in the combustion chamber 32 measured by the temperature sensor 116 exceeds a preset reference temperature, the air injection valve 140 is controlled to open and close to inject compressed air into the combustion chamber 32, thereby A cooling mode for automatically cooling the inside of the chamber 32 and its surroundings may be executed. As the reference temperature, a numerical value set in advance can be used, or an arbitrary numerical value can be set by the operator. Alternatively, the driving tool 10 may be provided with an operation unit for selecting the cooling mode, and the operator may manually execute the cooling mode. In other words, the compressed air may be injected into the combustion chamber 32 by the operator operating the operation unit at any timing.

As described above, according to the first embodiment, after the contact arm 52 is operated to inject the fuel, the trigger 62 is operated to inject the compressed air. The time from turning on the trigger 62 to driving the nail can be shortened, and the trigger response of the driving tool 10 can be improved.

In addition, by linking the start of injection of compressed air with the operation of the trigger 62, there is no need to consume air even when the contact is reconnected for positioning. Quantity can be improved. In addition, when the contact arm 52 is turned on, no compressed air is injected, and the injection of compressed air is completed after the trigger 62 is turned on. Therefore, even if the concentration of the fuel (gas) becomes high, it is possible to prevent the combustion pressure exceeding the specified level from being generated in the combustion chamber 32 . As a result, the driving force can be stabilized by stabilizing the combustion pressure, and the durability of the driving tool 10 can be ensured.

Further, according to the present embodiment, fuel is injected into combustion chamber 32 when contact switch 110 is turned on, and compressed air is injected into combustion chamber 32 when trigger switch 112 is subsequently turned on. Fuel in the combustion chamber 32 can be agitated by the compressed air injected into the combustion chamber 32 . As a result, the fuel and the compressed air are evenly mixed, so that the combustion efficiency can be improved at the spark of the driving operation.

Further, since the ignition timing of the spark plug 150 is set in consideration of the discharge voltage of the spark plug 150, that is, the time for the voltage to rise, the fuel is ignited at the optimum timing (immediately after the injection of compressed air is completed). be able to. As a result, it is possible to improve fuel efficiency and trigger response.

Furthermore, even if the compressed air injection time is adjusted for reasons such as varying the output energy, the fuel can be ignited at the optimum timing immediately after the compressed air injection ends. , combustion efficiency and trigger response can be improved.

[First Modification of First Embodiment]
Next, an example of control when both fuel injection and compressed air injection are performed after the contact switch 110 is turned on will be described. FIG. 6 shows an example of a second timing chart during the driving operation of the driving tool 10 according to the present invention.

As shown in FIG. 6, at time t1, when the contact arm 52 is pushed into the member to be driven by the operator, the contact arm 52 moves upward relative to the nose 50, and the contact switch 110 goes high. to low level, and the contact switch 110 is turned on.

When the contact arm 52 is continuously turned on for a predetermined time, the drive signal output to the fuel injection valve 130 switches from low level to high level at time t2. As a result, the fuel injection valve 130 is opened, and fuel is injected into the combustion chamber 32 from the fuel injection port of the cylinder head 30 for the injection time calculated in advance.

At time t3, the drive signal supplied to fuel injection valve 130 switches from high level to low level. As a result, the fuel injection valve 130 is closed, and the injection of fuel into the combustion chamber 32 from the fuel injection port of the cylinder head 30 is stopped.

At time t4, the drive signal supplied to air injection valve 140 switches from low level to high level. As a result, the air injection valve 140 is opened, and compressed air is injected into the combustion chamber 32 from the air injection port of the cylinder head 30 for an injection time corresponding to the set output energy.

At time t5, when a preset air injection time has elapsed, the drive signal supplied to air injection valve 140 switches from high level to low level. As a result, the air injection valve 140 is closed, and the injection of compressed air into the combustion chamber 32 from the air injection port of the cylinder head 30 is stopped.

At time t6, when the operator pulls the trigger 62 while the contact arm 52 is on, the trigger switch 112 switches from high level to low level, and the trigger switch 112 is turned on.

From time t7 to t8, the driving signal supplied to the ignition device switch 152 switches from high level to low level, and the ignition plug 150 ignites. Thus, the driving operation is performed.

As described above, in the first modification of the first embodiment, the ON of the contact switch 110 is used as a trigger to control both fuel injection and compressed air injection. Even with such control, the driving operation can be performed immediately after the compressed air is injected after the trigger 62 is turned on. 10 can be improved in operability.

[Second Modification of First Embodiment]
Next, an example of control in the case of dividing the injection of compressed air into two times and performing it will be described. FIG. 7 shows an example of a timing chart in each device during the driving operation of the driving tool 10 according to the present invention.

As shown in FIG. 7, when the operator pushes the contact arm 52 into the workpiece at time t1, the contact arm 52 moves upward relative to the nose 50, and the contact switch 110 goes high. to low level, the contact switch 110 is turned on.

When the contact arm 52 is continuously turned on for a predetermined time, the drive signal output to the fuel injection valve 130 switches from low level to high level at time t2. As a result, the fuel injection valve 130 is opened, and fuel is injected into the combustion chamber 32 from the fuel injection port of the cylinder head 30 for the injection time calculated in advance.

At time t3, the drive signal supplied to fuel injection valve 130 switches from high level to low level. As a result, the fuel injection valve 130 is closed, and the injection of fuel into the combustion chamber 32 from the fuel injection port of the cylinder head 30 is stopped.

At time t4, the drive signal supplied to air injection valve 140 switches from low level to high level. As a result, the air injection valve 140 opens, and the first compressed air is injected into the combustion chamber 32 from the air injection port of the cylinder head 30 . For example, in the first injection of compressed air, injection is performed for 1/4 of the entire injection time.

At time t5, when a preset air injection time has elapsed, the drive signal supplied to air injection valve 140 switches from high level to low level. As a result, the air injection valve 140 is closed, and the injection of compressed air into the combustion chamber 32 from the air injection port of the cylinder head 30 is stopped.

At time t6, when the operator pulls the trigger 62 while the contact arm 52 is on, the trigger switch 112 switches from high level to low level, and the trigger switch 112 is turned on.

At time t7, the drive signal supplied to air injection valve 140 switches from low level to high level. As a result, the air injection valve 140 is opened, and compressed air is injected into the combustion chamber 32 from the air injection port of the cylinder head 30 for the second time. For example, in the second injection of compressed air, injection is performed for the remaining 3/4 of the entire injection time.

At time t8, when a preset air injection time has elapsed, the drive signal supplied to air injection valve 140 switches from high level to low level. As a result, the air injection valve 140 is closed, and the injection of compressed air into the combustion chamber 32 from the air injection port of the cylinder head 30 is stopped.

From time t9 to t10, the drive signal supplied to the ignition device switch 152 switches from high level to low level, and the ignition plug 150 is turned on. Thereby, the driving operation is performed.

Thus, in the second modification of the first embodiment, the first compressed air is injected when the contact switch 110 is turned on, and the second compressed air is injected when the trigger switch 112 is turned on. It is controlled to perform injection of Even with such control, the driving operation can be performed immediately after the compressed air is injected after the trigger 62 is turned on. 10 can be improved in operability.

<Second Embodiment>
In the second embodiment, scavenging of the driving tool 10 will be described in detail. Since the basic configuration and operation of the driving tool 10 are common to those of the first embodiment, common constituent elements are denoted by the same reference numerals, and detailed description thereof will be omitted.

[Timing chart during operation of driving tool 10]
FIG. 8 shows a timing chart of each device and a graph of pressure variation in the combustion chamber 32 during the driving operation of the driving tool 10 according to the present invention. In the graph, the vertical axis is pressure and the horizontal axis is time.

As shown in FIG. 8, at time t1, when the contact arm 52 is pushed into the member to be driven by the operator, the contact arm 52 moves upward relative to the nose 50, and the contact switch 110 goes high. to low level, and the contact switch 110 is turned on.

When the contact switch 110 is turned on, the drive signal output to the fuel injection valve 130 switches from low level to high level. As a result, the fuel injection valve 130 is opened, and fuel is injected into the combustion chamber 32 from the fuel injection port of the cylinder head 30 . At time t2, the drive signal supplied to fuel injection valve 130 switches from high level to low level. As a result, the fuel injection valve 130 is closed, and the injection of fuel into the combustion chamber 32 from the fuel injection port of the cylinder head 30 is stopped.

At time t3, when the operator pulls the trigger 62 while the contact arm 52 is on, the trigger switch 112 is switched from high level to low level, and the trigger switch 112 is turned on.

When both the contact switch 110 and the trigger switch 112 are turned on, the drive signal supplied to the air injection valve 140 switches from low level to high level. As a result, the air injection valve 140 is opened, and compressed air is injected into the combustion chamber 32 from the air injection port of the cylinder head 30 .

From time t4 to t5, the ignition device switch 152 is switched from high level to low level, and the ignition device switch 152 is turned on. As a result, voltage boosting to the spark plug 150 is started.

At time t6, when a preset air injection time has elapsed, the drive signal supplied to air injection valve 140 switches from high level to low level. As a result, the air injection valve 140 is closed, and the injection of compressed air into the combustion chamber 32 from the air injection port of the cylinder head 30 is stopped.

As shown in the graph of FIG. 8, when the compressed air is injected into the combustion chamber 32, the pressure inside the combustion chamber 32 gradually increases with the injection amount of the compressed air. go.

When the ignition device switch 152 is turned on at time t4, the voltage rise to the discharge voltage of the ignition plug is completed at time t7, and the mixture in the combustion chamber 32 is ignited. As a result, the mixture in the combustion chamber 32 is combusted, resulting in a sudden increase in pressure. At time t8, which indicates the peak value of the combustion pressure, the head valve 24 opens, and the combustion pressure causes the piston 34 to move downward in the cylinder 22. move to As the piston 34 moves, exhaust of combustion gas in the combustion chamber 32 and the cylinder 22 (above the piston 34) starts.

After time t8, the combustion pressure flows into the cylinder 22 and the pressure in the combustion chamber 32 rapidly decreases.

In the vicinity of time t9, the piston 34 lands and the driven member is driven. At this time, an impact is generated in the driving tool 10, and the pressure in the combustion chamber 32 vibrates up and down accordingly.

At time t10, the piston 34 moves upward within the cylinder 22 and returns to its initial position. That is, the return of the piston 34 to the initial position is completed. After driving, the combustion gas in the combustion chamber 32 and the cylinder 22 is exhausted.

In this embodiment, the control unit 100 determines that the return of the piston 34 is completed when a predetermined time has passed since the trigger 62 was turned on. This is because the injection time of the compressed air, the movement time of the piston 34, and the like can be calculated in advance. In addition, as a method for detecting the return of the piston 34 other than the above, it is determined whether or not a predetermined time has elapsed after the control unit 100 outputs the spark signal to the ignition device switch 152. , acceleration, and strain may be determined based on whether a predetermined time has elapsed since the detection of the acceleration or strain. Further, the position detection means for detecting the completion of the return of the piston 34 to the initial position is composed of, for example, a magnet attached to the piston 34 and a Hall sensor attached to the cylinder 22 or the like. Completion of the return of the piston 34 (completion of the driving operation) may be determined by detecting the change. Also, changes in the pressure in the combustion chamber 32 are detected using a pressure sensor or the like as position detecting means installed in the combustion chamber 32, and the return of the piston 34 is detected based on the pressure change in the combustion chamber 32. Completion can also be determined. Further, the completion of the return of the piston 34 can be determined by detecting the position of the piston 34 using magnetism, laser, or the like as position detecting means. Further, the control unit 100 may determine that the return of the piston 34 is completed after a predetermined time has elapsed since the start of exhaust from the combustion chamber 32 and supply compressed air to the combustion chamber 32 . Whether or not the exhaust has started can be determined, for example, based on the pressure change in the combustion chamber 32 or the cylinder 22 described above, or by detecting a change in the position of the piston 34 .

At time t11, when driving the nail into the driven member is completed and the operator's finger is released from the trigger 62, the trigger switch 112 is switched from low level to high level, and the trigger switch 112 is turned off.

At time t12, when the contact arm 52 moves away from the workpiece and returns to the initial position, the contact switch 110 switches from low level to high level, and the contact switch 110 is turned off.

When the contact switch 110 is turned off, the drive signal supplied to the air injection valve 140 switches from low level to high level at time t13 after a predetermined time has elapsed. As a result, the air injection valve 140 opens, and compressed air is injected into the combustion chamber 32 from the air injection port of the cylinder head 30 for a preset injection time, thereby exhausting the exhaust gas in the combustion chamber 32. Scavenging is performed. Thus, in the present embodiment, when the control unit 100 detects that the contact switch 110 has been turned off and that the piston 34 has returned, that is, after driving the nail into the nailed member is completed, the control unit 100 perform scavenging.

As described above, according to the second embodiment, the combustion chamber 32 is automatically scavenged after the driving operation is completed, and the exhaust gas in the combustion chamber 32 is discharged. A clean state can be obtained, and the output of the next driving operation can be stabilized. In addition, it is possible to improve the ignitability and workability of the mixture.

Moreover, it is fully assumed that the driving tool 10 is lifted by the recoil of driving the nail, and the contact is turned off before the piston 34 returns completely. According to the present embodiment, after the return of the piston 34 is completed, the air injection valve 140 is actuated to perform scavenging. Moreover, since the return operation of the piston 34 is not hindered, a more stable driving operation can be achieved.

In the general driving tool 10, for example, in a low temperature environment, the ignition performance is greatly affected, so more reliable scavenging of the combustion chamber 32 is required. According to the present embodiment, since scavenging can be performed after the driving operation is completed, deterioration of ignition performance can be reliably prevented. Also, by adopting a configuration in which the scavenging time is variable, the amount of air consumption can be reduced.

Further, when it is determined that the return of the piston 34 is completed after a predetermined time has elapsed since the trigger 62 was turned on, detection of the displacement of the piston 34, etc., can be omitted, and the structure of the driving tool 10 can be simplified. can.

In addition, when only the ON operation of the contact arm 52 is performed, the fuel injected into the combustion chamber 32 is discharged, and the mixture remaining in the combustion chamber 32 when misfiring for some reason can also be scavenged. can be done. As a result, the next combustion is performed with an optimum ratio of fuel and air, so that the output of the driving operation can be stabilized and soot generation in the fuel hose 132 and the combustion chamber 32 can be suppressed.

Furthermore, according to this embodiment, scavenging can be performed without using a fan and a motor for driving the same, so the structure of the driving tool 10 can be simplified.

Note that scavenging can also be performed when the contact switch 110 is off and the return of the piston 34 is detected. For example, the control unit 100 may perform scavenging when it detects that the contact arm 52 is turned off without the trigger 62 being turned on after the contact arm 52 is turned on. As a result, scavenging can be performed quickly. Also, when the contact arm 52 is turned on again, excessive fuel will not be supplied into the combustion chamber 32, so combustion can be stabilized.

[First Modification of Second Embodiment]
FIG. 9 is a flow chart showing an example of the scavenging operation when the gas can is attached first and then the air source is attached.

As shown in FIG. 9, in step S200, the control unit 100 determines whether the gas can 66 is attached to the gas cartridge storage unit 64 based on the output of the gas can detection switch 114. As shown in FIG. When the control unit 100 determines that the gas can 66 is not attached to the gas cartridge storage portion 64 , it continues to monitor whether the gas can 66 is attached to the gas cartridge storage portion 64 . On the other hand, when the control section 100 determines that the gas can 66 is attached to the gas cartridge housing section 64, the process proceeds to step S210.

In step S<b>210 , the control unit 100 controls opening and closing of the fuel injection valve 130 to discharge the air preliminarily accumulated inside the fuel hose 132 and inside the fuel injection valve 130 into the combustion chamber 32 . That is, air bleeding from the fuel injection valve 130 is performed. The control unit 100 stops the operation of the fuel injection valve 130 when the air inside the fuel hose 132 and the like is exhausted. After step S210 ends, the process proceeds to step S220.

In step S220, it is determined based on the output of the pressure sensor 118 whether connection of an air source such as an air compressor to the air plug 144 has been detected. When the controller 100 determines that the connection of the air source to the air plug 144 is not detected, it continues to monitor the connection of the air source to the air plug 144 . On the other hand, when the control unit 100 determines that connection of the air source to the air plug 144 has been detected, the process proceeds to step S230.

In step S230, the control unit 100 controls the opening and closing of the air injection valve 140 to inject a predetermined amount of compressed air into the combustion chamber 32 for scavenging. After performing scavenging for a predetermined time, the control unit 100 stops the operation of the air injection valve 140 .

According to this modification, air is removed when the gas can 66 is attached, and scavenging is performed when the air source is attached, so that the inside of the combustion chamber 32 can be kept clean during driving. As a result, a stable driving operation can be performed, and soot generation due to the enrichment of the fuel can be suppressed.

[Second Modification of Second Embodiment]
FIG. 10 is a flow chart showing an example of the scavenging operation when the air source is attached first and then the gas can is attached.

As shown in FIG. 10, in step S300, control unit 100 determines whether an air source such as an air compressor is attached to air plug 144 based on the output of pressure sensor 118. As shown in FIG. If the controller 100 determines that the air source is not attached to the air plug 144 , it continues to monitor whether the air source is attached to the air plug 144 . On the other hand, when the control unit 100 determines that the air source is attached to the air plug 144, the process proceeds to step S310.

In step S310, the control unit 100 controls the opening and closing of the air injection valve 140 to inject a predetermined amount of compressed air into the combustion chamber 32 for scavenging. After performing scavenging for a predetermined time, the control unit 100 stops the operation of the air injection valve 140 . After step S310 ends, the process proceeds to step S320.

At step S 320 , the control unit 100 determines whether the gas can 66 is attached to the gas cartridge housing 64 based on the output of the gas can detection switch 114 . When the control unit 100 determines that the gas can 66 is not attached to the gas cartridge storage portion 64 , it continues to monitor whether the gas can 66 is attached to the gas cartridge storage portion 64 . On the other hand, when the control section 100 determines that the gas can 66 is attached to the gas cartridge housing section 64, the process proceeds to step S330.

In step S330, the control unit 100 controls the opening and closing of the fuel injection valve 130 to discharge the air preliminarily accumulated inside the fuel hose 132 and inside the fuel injection valve 130 into the combustion chamber 32 to remove the air. The control unit 100 stops the operation of the fuel injection valve 130 when the air inside the fuel hose 132 and the like is exhausted. After step S330 ends, the process proceeds to step S340.

In step S340, the control unit 100 controls the opening and closing of the air injection valve 140 to inject a predetermined amount of compressed air into the combustion chamber 32 for scavenging. As a result, the fuel accumulated in the combustion chamber 32 is exhausted to the outside. After performing scavenging for a predetermined time, the control unit 100 stops the operation of the air injection valve 140 .

Also according to this modified example, since air bleeding and scavenging are performed when the gas can 66 is mounted after the air source is mounted, the inside of the combustion chamber 32 can be kept clean during driving. As a result, a stable driving operation can be performed, and soot generation due to the enrichment of the fuel can be suppressed.

[Third Modification of Second Embodiment]
FIG. 11 is a flow chart showing an example of operation when scavenging is performed after both the air source and the gas can are attached.

As shown in FIG. 11, at step S400, the control unit 100 determines whether an air source such as an air compressor is attached to the air plug 144 and whether the gas can 66 is attached to the gas cartridge housing portion 64 or not. If the control unit 100 determines that the air source is attached to the air plug 144 and the gas can 66 is not attached to the gas cartridge storage unit 64, it continues to monitor whether or not they are attached. On the other hand, when the control unit 100 determines that the air source is attached to the air plug 144 and the gas can 66 is attached to the gas cartridge housing portion 64, the process proceeds to step S410.

In step S410, the control unit 100 controls the opening and closing of the fuel injection valve 130 to discharge the air preliminarily accumulated inside the fuel hose 132 and inside the fuel injection valve 130 into the combustion chamber 32 to remove the air. The control unit 100 stops the operation of the fuel injection valve 130 when the air inside the fuel hose 132 and the like is exhausted. After step S410 ends, the process proceeds to step S420.

In step S420, the control unit 100 controls the opening and closing of the air injection valve 140 to inject a predetermined amount of compressed air into the combustion chamber 32 for scavenging. As a result, the fuel accumulated in the combustion chamber 32 is exhausted to the outside. After performing scavenging for a predetermined time, the control unit 100 stops the operation of the air injection valve 140 .

Also according to this modification, air is removed and scavenged when the air source and the gas can 66 are attached, so the inside of the combustion chamber 32 can be kept clean during driving. As a result, a stable driving operation can be performed, and soot generation due to the enrichment of the fuel can be suppressed.

<Third Embodiment>
In the third embodiment, the operation of the machine is controlled based on the state information of the driving tool 10. FIG. Since the basic configuration and functions of the driving tool 10 are common to those of the first embodiment, the same reference numerals are given to the common constituent elements, and detailed description thereof will be omitted.

FIG. 12 is a flow chart showing an example of the operation when determining a mechanical abnormality in the driving tool 10. As shown in FIG. As shown in FIG. 12, in step S500, the temperature sensor 116 detects (obtains) the temperature of the driving mechanism 20 and the like in the tool body 12, and the control unit 100 controls the machine (for example, the driving mechanism 20 and the like) of the driving tool 10 ( mechanism) is obtained from the temperature sensor 116 . After step S500 ends, the process proceeds to step S510.

In step S510, the controller 100 determines whether or not the machine temperature of the driving tool 10 is within a predetermined range of specified values. When the temperature of the machine of the driving tool 10 is within the range of specified values, the control unit 100 determines that the machine of the driving tool 10 is operating normally, and continuously monitors the temperature of the machine of the driving tool 10. do. On the other hand, when the temperature of the machine of the driving tool 10 is not within the range of the specified value, the control section 100 determines that the machine of the driving tool 10 has an abnormality, and proceeds to step S520.

In step S520, the control unit 100 stops mechanical operation of the driving tool 10. FIG. Specifically, the control unit 100 performs control so as not to operate at least one of the fuel injection valve 130, the air injection valve 140, and the spark plug 150, thereby stopping the driving operation. When step S520 ends, the process proceeds to step S530.

At step S530, the control unit 100 notifies the operator that the driving tool 10 has an abnormality. As an example of the notification means, a light-emitting element (light-emitting body) such as an LED that lights in a predetermined color or in a predetermined pattern, or a voice output unit that performs warning sound or voice guidance can be used. Also, for the lighting pattern and the warning sound output pattern, it is possible to set a plurality of different notification patterns corresponding to the content of the abnormality. As a result, the operator can accurately grasp what kind of abnormality has occurred in the driving tool 10 from the warning sound and light emission pattern.

In addition, although the example which used the temperature information of the driving tool 10 as the state information of the driving tool 10 was demonstrated in the example mentioned above, it is not limited to this. For example, the control unit 100 uses at least one information of the pressure value of the compressed air supplied to the driving tool 10, the pressure value in the combustion chamber 32 into which the compressed air is injected, and the voltage value of the battery 70, It is possible to determine whether or not there is an abnormality in the machine based on whether the information is within a preset reference value range. Here, the pressure value of the compressed air supplied to the driving tool 10 can be detected by the pressure sensor 118, the pressure value in the combustion chamber 32 can be detected by the pressure sensor 120, and the voltage value of the battery 70 can be measured by providing a voltage measuring device. can be detected by

As described above, according to the third embodiment, even if the temperature of the machine rises due to continuous use of the driving tool 10, the temperature rise is judged to be abnormal and the driving operation is stopped, thereby stabilizing the driving operation. can be improved. In addition, since it is determined whether the pressure in the combustion chamber 32 or the pressure supplied from the air source is abnormal, damage to the combustion chamber 32, the air injection valve 140, or other machinery can be prevented, and durability can be improved. can be planned. Furthermore, according to the present embodiment, the driving tool 10 can be prevented from operating abnormally, so the safety of the driving tool 10 can be further improved.

Here, there are cases where switch chattering occurs due to impact during the driving operation, resulting in erroneous detection of the switch. In response to this, a hard filter, a soft filter that determines when the high or low signal of the switch continues for a predetermined time or more, a switch is not detected until a predetermined time has passed since the trigger 62 is turned on or an ignition command is output. , it is possible to prevent erroneous switch detection.

It should be noted that the technical scope of the present invention is not limited to the above-described embodiments, and includes various modifications to the above-described embodiments within the scope of the present invention. Also, the processes described in this specification using flowcharts and sequence diagrams do not necessarily have to be executed in the illustrated order. Also, additional processing steps may be employed, and some processing steps may be omitted.

In the embodiment described above, as an example, fuel is injected into the combustion chamber 32 when the contact switch 110 is turned on, and then compressed air is injected into the combustion chamber 32 when the trigger switch 112 is turned on. However, it is not limited to this. For example, when the contact arm 52 is pressed against the driven member and the contact switch 110 is turned on, the air injection valve 140 is opened to inject compressed air into the combustion chamber 32, and then the trigger 62 is pulled. The fuel injection valve 130 may be opened to inject fuel into the combustion chamber 32 when the trigger switch 112 is turned on. According to such control, not only is the above-described operation response improved, but even when the contact arm 52 is repeatedly turned on, fuel is not injected, so it is possible to prevent fuel from being wasted. .

10 driving tool 12 tool body 32 combustion chamber 52 contact arm (contact member)
62 trigger 100 control unit 120 pressure sensor (pressure measurement unit)
130 fuel injection valve 140 air injection valve (valve)
150 spark plug (ignition device)

Claims (8)

a combustion chamber supplied with fuel and compressed air;
a cylinder that movably accommodates a piston that is driven by combustion pressure when a mixture of fuel and compressed air filled in the combustion chamber is ignited;
a valve for opening and closing a path for supplying compressed air into the combustion chamber;
a trigger that activates an ignition device to burn a mixture of fuel and compressed air that fills the combustion chamber;
a contact member that contacts the member to be driven to enable the operation of the trigger;
A control unit that controls the valve,
The control unit
controlling the valve so as to start supplying compressed air to the combustion chamber after an ON operation of the contact member, and stop supplying the compressed air after a predetermined time has elapsed from the start of supply;
After the mixture of compressed air and fuel supplied to the combustion chamber is burned and exhaust from the combustion chamber is started, and when it is determined that the return of the piston is completed, the combustion chamber a driving tool for controlling said valve to supply compressed air as scavenging air to the The driving tool according to claim 1, wherein the control unit determines that the return of the piston is completed after a predetermined time has elapsed since the trigger was turned on. The driving tool according to claim 1, wherein the control unit determines that the return of the piston is completed after a predetermined time has elapsed since exhaustion from the combustion chamber was started. A position detection means for detecting the position of the piston,
The driving tool according to any one of claims 1 to 3, wherein the control section determines that the return of the piston is completed based on the position information obtained by the position detection means. Equipped with a mounting part to which a gas can that supplies fuel is mounted,
The driving according to any one of claims 1 to 4, wherein the control unit controls the valve to supply compressed air to the combustion chamber when it is determined that the gas can is attached to the attachment unit. tool. A temperature measuring unit that measures the temperature of the combustion chamber,
6. The control unit controls the valve to supply compressed air to the combustion chamber when the temperature of the combustion chamber measured by the temperature measurement unit exceeds a predetermined temperature. The driving tool according to item 1. The driving tool according to any one of claims 1 to 6, further comprising an operating portion that opens and closes the valve. a combustion chamber supplied with fuel and compressed air;
a cylinder movably accommodating a piston driven by a combustion pressure when a mixture of fuel and compressed air filled in the combustion chamber is ignited;
a valve for opening and closing a path for supplying compressed air into the combustion chamber;
a fuel injection valve for opening and closing a path for supplying fuel into the combustion chamber;
a trigger that activates an ignition device to burn a mixture of fuel and compressed air that fills the combustion chamber;
a contact member that contacts the member to be driven to enable the operation of the trigger;
a control unit that controls the valve and the fuel injection valve,
The control unit
controlling the fuel injection valve to supply the fuel to the combustion chamber in response to the turning on of the contact member;
After the contact member is turned on, when it is determined that the contact member is turned off without the trigger being turned on, compressed air is supplied to the combustion chamber as scavenging air after the exhaust from the combustion chamber is started. A driving tool that controls the valve.

Images