JP4151346B2 - Combustion type driving tool - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a combustion type driving tool that burns and explodes combustible gas to increase pressure and drives a nail.
[0002]
[Prior art]
FIG. 4 shows an example of a combustion type driving tool. In this case, conventional combustion type driving tools of this type are, for example, JP-B-1-34753, JP-B-4-48589, JP-B-3-25307, JP-B-4-11337, and JP-B-64-9149. No. 3 and Japanese Patent Publication No. 3-25307.
[0003]
A housing 14, which forms a main body frame, is accompanied by a handle 11, a tail cover 1, a push lever 21, a magazine 13, and a trigger switch 12. Inside the housing 14, a cylinder 4, a piston 10, a fan 6, and a fan 6 are provided. A motor (not shown) for rotational driving, a plug 9, an injection port (not shown), a gas cylinder 7, a combustion chamber frame 15, a head cover 23, and a head switch 25 are installed.
[0004]
In the housing 14, the cylinder 4 and the head cover 23 are fixed to the housing 14, the combustion chamber frame 15 is guided by the housing 14 and the cylinder 4, and is urged downward by a spring (not shown). It can move in the axial direction. A space closed by the combustion chamber frame 15, the head cover 23, and the piston 10 forms a sealed combustion chamber 5 in which a mixed gas of combustible gas and air burns. The head switch 25 is provided so that the head switch 25 is turned on when the combustion chamber frame 15 forms the sealed combustion chamber 5. A piston 10 is movably installed in the cylinder 4 via a sliding seal member (not shown). An exhaust hole (not shown) is provided below the cylinder 4 and a check valve (not shown) is provided outside the exhaust hole. The combustion chamber 5 has an ignition plug 9 that is ignited when the fan 6, the trigger switch 12 and the head switch 25 that are rotated by the motor provided outside the combustion chamber 5 and above the head cover 23 are turned on. There are an injection port (not shown) for injecting a gas supplied from a gas cylinder 7 containing a combustible gas provided outside the combustion chamber 5, and a rib 24 protruding in a protruding shape. The combustion chamber frame 15 is connected to the push lever 21 via the rod 30. A magazine 13 filled with nails (not shown) below the housing 14 and a tail cover 1 for feeding the nails to the magazine 13 and setting and guiding them below the piston 10 are attached. Further, the handle 11 is provided with an LED 26 for displaying that the battery is attached when the trigger switch 12 and the battery (not shown) are attached.
[0005]
As shown in FIG. 4, when the push lever 21 is pressed against the wood 27, the rod 30 and the combustion chamber frame 15 rise together with the push lever 21. Combustion chamber 5 hermetically sealed with respect to the outside air is formed by ascending combustion chamber frame 15, and thereafter, combustible gas in gas cylinder 7 is injected into combustion chamber 5 from the injection port in conjunction with it. When the combustion chamber frame 15 is raised, the head switch 25 is turned on, the fan 6 is rotated, and the combustible gas and air are mixed and stirred. Here, when the trigger switch 12 is turned on, the spark plug 9 sparks and ignites the mixture of combustible gas and air. The piston 10 is driven downward by the combustion and expansion of the combustible gas, and the nail in the tail cover 1 is driven into the wood 27 by the driver blade 16. When the piston 10 descends to near the bottom dead center, the exhaust hole of the cylinder 4 communicates with the upper chamber of the piston 10, high-temperature and high-pressure combustion gas is exhausted through the check valve, and the pressure in the combustion chamber 5 decreases. At the same time, the heat of the combustion gas is transmitted to and absorbed in the combustion chamber 5 and the inner wall of the cylinder 4 and rapidly cooled, and the pressure in the combustion chamber 5 further decreases. When the pressure drops to atmospheric pressure, the check valve closes and exhaust is no longer possible. In this state, the rapid cooling continues, the upper chamber of the piston 10 becomes negative pressure (referred to as “thermal vacuum”), and the lower surface of the piston 10 is at atmospheric pressure. Return to position. Thereafter, when the tool body is lifted, the push lever 21 is moved away from the wood 27 and the trigger switch 12 is turned off, the combustion chamber frame 15 is also lowered, and the closed and sealed combustion chamber 5 is opened to the atmosphere. Since the fan 6 continues to rotate, the remaining combustion gas in the combustion chamber 5 is scavenged and replaced with fresh air, and the state returns to the initial state where the next nail can be driven.
[0006]
The operation of such a combustion type driving tool will be described with reference to FIGS.
The configuration of the control circuit is the fan drive circuit 205 for driving the fan 6, that is, the motor, the spark ignition circuit 206 that sparks the spark plug 9 to ignite the air-fuel mixture, the microcomputer 203 that is the center of control, and the power source thereof. The battery 200 includes a trigger switch 12 and a head switch 25. When the trigger switch 12 and the head switch 25 are turned on, the microcomputer 203 drives a fan drive circuit 205, a spark ignition circuit 206, for example, a display circuit 204 composed of LEDs.
[0007]
The operation of the microcomputer 203 will be described with reference to FIG.
[0008]
When the battery 200 is mounted on the tool body, the microcomputer 203 is activated to perform initial setting for resetting the fan timer (S200), and the display circuit 204 is displayed (S202). If both the head switch 25 and the trigger switch 12 are in the off state, it is determined whether or not the fan timer has counted up (S208), and if not counted up, the process returns to S204. If the count is up in S208, the fan is stopped and the process returns to S204.
[0009]
When the head switch 25 is turned on (S204), the fan drive circuit 205 is operated to turn on the fan 6 (S212). In this state, if it is determined that the trigger switch 12 is turned on (S214), the spark ignition circuit 206 is turned on (S222), the driving operation is performed, the fan timer is reset and restarted (S224). Thereafter, when both the head switch 25 and the trigger switch 12 are turned off, the exhaust gas in the combustion chamber 5 is scavenged, so the fan 6 is driven until the fan timer counts up (S208), and then the fan 6 is turned off (S210). ).
[0010]
In the above-described configuration, when the battery 200 is attached, if the battery 200 for displaying, for example, the LED of the display circuit 204 is left attached or stored, the battery 200 will be discharged and cannot be used when desired. Or the battery 200 may be overdamaged due to overdischarge. Further, if the trigger switch 12 and the head switch 25 are accidentally turned on when left or stored with the battery 200 attached, a driving operation is performed. From this point, the battery 200 is removed from the tool body. It is desirable to leave it off.
[0011]
Therefore, as disclosed in US Pat. No. 6,012,622, a structure has been proposed in which a spring and a step are provided in the battery insertion portion of the tool body so that the battery can be held in a standby state without contacting the terminal.
[0012]
[Problems to be solved by the invention]
However, leaving the battery in a standby state each time when not working or storing is time-consuming and often forgotten, just like removing it. Further, when the battery is held in a standby state at the insertion slot, there is a problem that it is difficult to determine whether the battery is in a standby state or whether the battery is completely inserted into the insertion slot and is overdischarged.
[0013]
An object of the present invention is to provide a combustion type driving tool that eliminates the above-described problems of the prior art, does not consume batteries, and is safe and does not impair usability.
[0014]
[Means for Solving the Problems]
The above object is achieved by mounting the safety switch on the tool body and turning off the safety switch when the driving tool is not used. Furthermore, if the trigger switch or the head switch is not turned on continuously for a predetermined time or longer, a control unit that automatically turns off the safety switch is provided, so that even if the safety switch is forgotten to be turned off, it is possible to prevent the battery from being consumed. In addition, it is desirable that the safety switch is disposed between the control means and the battery so that the control circuit is not energized when the safety switch is turned off.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a block diagram of a drive control circuit for a combustion type driving tool according to an embodiment of the present invention. The combustion type driving tool includes a battery 100, a trigger switch 12, a head switch 25, and a safety switch 101.
[0016]
Control is performed by the microcomputer 103, the fan 6 is driven by the fan drive circuit 105, and the spark ignition is driven by the spark ignition circuit 106. The display circuits 104a and 104b are for causing the operator to change the state of the tool body by light or sound, and are controlled by the microcomputer 103. The safety switch 101 is installed between the battery 100, the microcomputer 103, the fan drive circuit 105, and the spark ignition circuit 106. In this case, the safety switch 101 is a momentary operation type switch, which is a switch that closes a contact only when it is operated and opens a contact when the operation is stopped. A transistor 102 is connected in parallel with the safety switch 101, and the transistor 102 is turned on / off by the output of the microcomputer 103.
[0017]
The operation of the microcomputer 103 will be described with reference to the flowchart of FIG.
[0018]
When the safety switch 101 is turned on, power is supplied to the microcomputer 103 and initialization is performed (S100). Then, the transistor 102 is turned on and the display circuit 104b is turned on. Since the transistor 102 is turned on, power is continuously supplied from the battery 100 to the microcomputer 103 and the like through the transistor 102 even when the safety switch 101 returns and the contact is released. The display circuit 104b displays that the power is turned on, and continues the display until the display timer counts up (S104).
[0019]
When the head switch 25 is turned on (S110), the display circuit 104a and the fan drive circuit 105 are operated, and the off timer is turned off (S128). The display circuit 104a displays that the preparation operation for the driving operation has been started. In this state, when it is determined that the trigger switch 12 is on (S130), the spark ignition circuit 106 is operated, and the driving operation is performed as described in the prior art (S138). Even if the trigger switch 12 and the head switch 25 are closed in this order, the same operation is performed.
[0020]
Then, the fan timer is reset and restarted (S140). When both the head switch 25 and the trigger switch 12 are turned off, the display circuit 104a is turned off (S114), and when the fan timer is counted up (S124), the fan drive circuit 105 is stopped (S126).
[0021]
Further, when both the trigger switch 12 and the head switch 25 are in the off state, the off timer is counted, and when the count is counted up (S116), the display circuit 104b is turned on and the entire drive control circuit is informed of the shutdown. When the display timer counts up (S120), the transistor 102 is turned off (S122), and the power of the entire drive control circuit is turned off. As a result, even if the battery 100 is left and stored with the battery 100 mounted, the power of the drive control circuit is automatically turned off, so that overdischarge of the battery 100 can be prevented. Further, even if both the trigger switch 12 and the head switch 25 are turned on with some beat in the neglected state, it is possible to prevent the driving operation from being started because the power of the drive control circuit is not supplied. If the user wants to use it again, turning on the safety switch 101 activates the microcomputer 103 to enable the driving operation.
[0022]
Here, the off timer is preferably about 5 to 15 seconds, and the off timer is preferably about 5 to 15 minutes. The display timer is preferably about 1 to 10 seconds.
[0023]
FIG. 2 shows a block diagram of a drive control circuit according to another embodiment of the present invention. In the case of this embodiment, the safety switch 101 ′ has a coil 110, and when the coil 110 is energized, the contact of the safety switch 101 is held in an on state. As in the above embodiment, when the safety switch 101 ′ is turned on and the microcomputer 103 operates, when the transistor 102 is turned on and the coil 110 is energized, the contact of the safety switch 101 ′ is held in the on state. If both the trigger switch 12 and the head switch 25 remain off for a certain time or more, the microcomputer 103 turns off the transistor 102 and the coil 110 is de-energized, so that the contact of the safety switch 101 ′ is opened and the off state. As a result, the power of the drive control circuit drops.
[0024]
Further, if the safety switch 101 is an ordinary on / off alternate operation type switch, the operator can manually perform the on / off operation.
[0025]
【The invention's effect】
As described above, according to the present invention, it is possible to provide a combustion type driving tool that is safe and easy to use without battery consumption.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an embodiment of a drive control circuit for a combustion type driving tool of the present invention.
FIG. 2 is a block diagram showing another embodiment of the drive control circuit for the combustion type driving tool of the present invention.
FIG. 3 is a flowchart for explaining the operation of the microcomputer of FIG. 1;
FIG. 4 is a sectional side view showing an example of a conventional combustion type driving tool.
FIG. 5 is a block diagram showing an example of the drive control circuit in FIG. 4;
6 is a flowchart for explaining the operation of the microcomputer of FIG. 4;
[Explanation of symbols]
100 is a battery, 101 is a safety switch, 12 is a trigger switch, 25 is a head switch, and 103 is a microcomputer.

Claims (7)

Combustible gas is supplied into a sealed combustion chamber formed by pressing the tool body against the workpiece, and the combustion chamber is stirred by a fan rotating in the combustion chamber to mix the combustible gas and air. The combustion chamber is ignited by igniting means, the piston supported to move up and down in the cylinder below the combustion chamber is lowered by the pressure rise due to the combustion explosion, and a nail is driven by a driver bit integrated with the piston. A combustion-type driving tool having a head switch that detects sealing and a trigger switch that is operated by an operator to start a driving operation, and includes a control unit that performs rotation of the fan and ignition of the ignition unit by a battery,
A safety switch is provided, and when the safety switch is on and the trigger switch and the head switch are turned on, the control means can be supplied with power from the battery so that the driving operation is performed. When the safety switch is off, the trigger switch and the head switch are turned on. In such a case, power is not supplied from the battery to the control means so as not to perform the driving operation .
A counter is provided to start counting when both the head switch and the trigger switch are in an off state, and the safety switch is turned off when the head switch and the trigger switch do not operate continuously for a predetermined time or more by the output of the counter. Combustion type driving tool characterized by being in a state . 2. The combustion type driving tool according to claim 1, wherein the safety switch is provided between the battery and the control means. The combustion type driving tool according to claim 1, wherein the counter operates when the safety switch is in an ON state. The combustion type driving tool according to any one of claims 1 to 3, wherein the safety switch is a self-holding type switch. Combustible gas is supplied into a sealed combustion chamber formed by pressing the tool body against the workpiece, and the combustion chamber is agitated by a fan rotating in the combustion chamber to mix the combustible gas and air. The combustion chamber is ignited by ignition means, and the piston supported to move up and down in the cylinder below the combustion chamber is lowered by the pressure rise due to the combustion explosion, and a nail is driven by a driver bit integrated with the piston. A combustion-type driving tool having a head switch that detects sealing and a trigger switch that is operated by an operator to start a driving operation, and includes a control unit that performs rotation of the fan and ignition of the ignition unit by a battery,
A safety switch is provided, and when the safety switch is turned on and the trigger switch and the head switch are turned on, power can be supplied from the battery to the control means so as to perform a driving operation, and when the safety switch is turned off, the trigger switch and While the head switch is turned on, power is not supplied from the battery to the control means so as not to perform the driving operation,
A switch means is connected in parallel with the safety switch, the switch means is turned on at the same time as the safety switch is turned on, and a counter is provided to start counting when the head switch and the trigger switch are not turned on. A combustion-type driving tool which returns the switch means to an off state when the head switch and the trigger switch do not operate continuously for a predetermined time or more by output. 6. The combustion type driving tool according to claim 5, wherein the safety switch is a momentary operation type switch. Combustible gas is supplied into a sealed combustion chamber formed by pressing the tool body against the workpiece, and the combustion chamber is agitated by a fan rotating in the combustion chamber to mix the combustible gas and air. It is ignited by the ignition means and burns and explodes. The piston, which is supported so as to be movable up and down in the cylinder, is lowered, and a nail is driven by a driver bit integrated with the piston. A combustion type driving tool having control means for providing a trigger switch for rotating the fan and igniting the ignition means by a battery,
A safety switch is provided, and when the safety switch is turned on and the trigger switch and the head switch are turned on, power can be supplied from the battery to the control means so as to perform a driving operation, and when the safety switch is turned off, the trigger switch and While the head switch is turned on, power is not supplied from the battery to the control means so as not to perform the driving operation,
When the safety switch is turned on, immediately before it is turned off, or both, a buzzer is sounded, light is emitted, or a vibrator is vibrated to notify the operator that the state changes. Combustion type driving tool.

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