JP7004154B2 - Gas combustion type driving tool - Google Patents

Description

The present invention relates to a gas combustion type driving tool for driving a fastener by the combustion pressure of a combustible gas.

Conventionally, a gas combustion type driving tool for driving a fastener by the combustion pressure of a combustible gas has been known. Further, as a method of improving the output of such a gas combustion type driving tool, there is an idea of launching a fastener by the combustion pressure when igniting a mixture of combustible gas and compressed air. That is, the conventional gas combustion type driving tool mixes the atmosphere and combustible gas, but by using compressed air instead of the atmosphere, a large output is produced by the energy of the compressed air and the thermal energy of the combustion gas. The method of obtaining was considered.

In addition, some methods for adjusting the output of such a gas combustion type driving tool have been proposed.

For example, Patent Document 1 proposes a method of adjusting the output by changing the operation timing of this valve by adjusting the pressure acting on a member (valve) provided between the combustion chamber and the cylinder. ing.

Further, Patent Document 2 proposes a method of adjusting the output by changing the volume of the combustion chamber.

In addition, a method of adjusting the output by using a well-known driving depth adjusting mechanism is also conceivable.

Japanese Unexamined Patent Publication No. 50-15177 Japanese Patent Application Laid-Open No. 63-28874

However, in the configuration described in Patent Document 1 described above, there is a problem that it is difficult to adjust the output because the valve operation timing and the output do not have a linear relationship. Further, in order to reduce the output, it is necessary to operate the valve at a timing when the energy conversion efficiency is poor, and there is a problem that fuel is wasted.

Further, in the configuration described in Patent Document 2 described above, there is a problem that a structure for locking the piston is required in order to change the volume of the combustion chamber, and the structure becomes complicated.

In addition, even in the method using the driving depth adjustment mechanism, there is a problem that fuel is wasted and a heavy load is applied to the bumper and the machine because the structure absorbs excess energy into the bumper or the like. rice field.

Therefore, it is an object of the present invention to provide a gas combustion type driving tool capable of accurately adjusting the output with a simple structure.

The present invention has been made to solve the above-mentioned problems, and is a combustion pressure when compressed air is taken in from the outside and ignited with respect to a mixture of combustible gas and compressed air supplied to the combustion chamber. A gas combustion type driving tool that ejects a fastener by means of an air injection valve that injects compressed air into the combustion chamber, a gas injection valve that injects flammable gas into the combustion chamber, and an upstream side or the air injection valve of the air injection valve. A pressure sensor arranged on the downstream side is provided, and the output related to the launch of the fastener can be adjusted by adjusting the opening time of the air injection valve and the gas injection valve based on the detection result of the pressure sensor. It is characterized by being.

The present invention is as described above, and the air injection valve for injecting compressed air into the combustion chamber, the gas injection valve for injecting flammable gas into the combustion chamber, and the gas injection valve arranged on the upstream side or the downstream side of the air injection valve. A pressure sensor is provided, and the output related to the embossing of the fastener can be adjusted by adjusting the opening times of the air injection valve and the gas injection valve based on the detection result of the pressure sensor . According to such a configuration, the filling pressure of the air-fuel mixture can be changed by adjusting the filling pressure of the compressed air and the filling pressure of the combustible gas. Since the filling pressure of the air-fuel mixture and the output energy are in a proportional relationship, the output can be adjusted accurately. In addition, the combustible gas can be burned in the most energy-efficient state regardless of the output setting, so that fuel is not wasted. Further, since the structure for adjusting the output mechanically is not required, the structure can be simple.

The setting of the filling pressure of the air-fuel mixture may be manually changed by the user of the gas combustion type driving tool .

It is a side view of the gas combustion type driving tool. It is a perspective view of the gas combustion type driving tool. It is a side sectional view of the gas combustion type driving tool. It is a partially enlarged side sectional view of a gas combustion type driving tool. FIG. 3 is a sectional view taken along line AA of a gas combustion type driving tool. It is a side view (partially BB line sectional view) of the gas combustion type driving tool. It is an enlarged side view (partial BB line sectional view) of the gas combustion type driving tool. It is a perspective view which shows the internal structure of a gas combustion type driving tool. It is a timing chart which shows the operation of a gas combustion type driving tool. It is a table which shows an example of an output setting. It is an enlarged side view (partial BB line sectional view) of the gas combustion type driving tool which concerns on a modification. It is a timing chart which shows the operation of the gas combustion type driving tool which concerns on the modification.

An embodiment of the present invention will be described with reference to the drawings. In the following description, as shown in FIG. 1, the launching direction of the fastener will be described as "front" and the opposite direction will be described as "rear". Further, the direction orthogonal to the launching direction of the fastener, the direction of the output unit 11 when viewed from the extending direction of the grip 30, will be described as "up" and the opposite direction will be described as "down".

The gas combustion type driving tool 10 according to the present embodiment is configured to launch a fastener by the combustion pressure when ignited with respect to a mixture of combustible gas and compressed air, and FIGS. 1 and 2. As shown in the above, the output unit 11, the grip 30, the gas can storage unit 37, the magazine 38, and the coupler 40 are provided.

As shown in FIGS. 3 and 4, the output unit 11 has a built-in combustion chamber 12. The combustion chamber 12 is a space for combusting combustible gas, and is for forming a space that can be sealed behind the piston 16 (the counter-launching direction of the fastener), which will be described later. The combustion pressure generated in the combustion chamber 12 acts on the piston 16 and is used to launch the fastener.

Further, a nose portion 18 is attached to the tip of the output portion 11 to guide the fastener to be driven toward the material to be driven. When the trigger operation unit 31 described later is operated to perform the driving operation, the fastener is formed so as to be driven from the injection port 18a opened at the tip of the nose portion 18 to the material to be driven.

The nose unit 18 is configured to be able to be pushed into the output unit 11, and the driving operation is not performed even if the trigger operation unit 31 is operated unless the pushing operation is performed. Specifically, the safety switch (not shown) is turned on by pushing the nose portion 18, and the signal of the trigger switch 32 described later is not valid unless this safety switch is turned on. It is configured in. Therefore, the fastener is not launched unless the nose portion 18 is pressed against the material to be driven, so that safety is ensured.

As shown in FIG. 4, the ignition device 13, the cylinder head 14, the cylinder 15, the piston 16, the driver 17, the cylinder member 20, the movable plug 21, the compression spring 22, and the like are inside the housing of the output unit 11 described above. It is contained.

The ignition device 13 is for generating sparks in the combustion chamber 12, and for example, the voltage of the battery pack 50, which will be described later, is boosted to a high voltage and the high voltage is discharged to generate sparks. It is a spark plug. The ignition device 13 executes an ignition operation at a predetermined timing based on a signal from the control device 33 described later. When the ignition device 13 operates and ignites the mixed gas in the combustion chamber 12, high-pressure combustion gas is generated in the combustion chamber 12, and the combustion pressure is configured to shockably slide the piston 16 described later. ing.

The cylinder head 14 is a member that forms a combustion chamber 12 together with a cylinder 15 described later. The cylinder head 14 is fixed so as to close the rear end portion of the cylindrical cylinder 15. The cylinder head 14 is provided with an air ejection section 44 and a gas ejection section 48, which will be described later, so that compressed air and flammable gas can be introduced into the combustion chamber 12 from the air ejection section 44 and the gas ejection section 48. It has become.

The cylinder 15 is a tubular member arranged along the longitudinal direction of the output unit 11. The cylinder 15 forms two spaces in the front and rear. The space in front is a space that slidably guides the piston 16 described later. Further, the space behind is a space for forming the combustion chamber 12. The two spaces before and after this communicate with each other, and a tubular member 20 described later is attached between them. Further, the two spaces before and after this can be shielded by the movable plug 21 housed in the tubular member 20.

The piston 16 is a member slidably housed inside the cylinder 15. When high-pressure combustion gas is generated in the combustion chamber 12, this combustion gas acts on the piston 16 so that the piston 16 operates forward.

The driver 17 is a member for striking the fastener and is coupled to the front of the piston 16. When the driving operation is executed, the driver 17 slides along the ejection path of the fastener and acts to eject the fastener in the ejection path from the ejection port 18a.

The cylinder member 20 is a cylindrical member fixed to the cylinder 15 in the combustion chamber 12. Inside the tubular member 20, a pressure chamber 20b for operating the movable plug 21, which will be described later, is formed. Further, a first opening 20a for communicating the combustion chamber 12 and the pressure chamber 20b is provided on the side portion of the tubular member 20. Further, a second opening 20c for communicating the combustion chamber 12 and the space behind the piston 16 is provided on the end surface of the tubular member 20 on the piston 16 side.

The movable plug 21 is a columnar member slidably arranged inside the tubular member 20. The movable plug 21 is urged toward the piston 16 by a compression spring 22 and is configured to close the second opening 20c in a natural state. Therefore, in the state before the driving operation, the space between the combustion chamber 12 and the space behind the piston 16 is shielded by the movable plug 21, and the combustion chamber 12 is a closed space.

Further, a groove is formed on the outer periphery of the movable plug 21, and the pressure chamber 20b described above is formed between the groove and the inner peripheral surface of the tubular member 20. In the natural state, the pressure chamber 20b communicates with the combustion chamber 12 and has the same air pressure as that in the combustion chamber 12. Further, a first pressure receiving surface 21a and a second pressure receiving surface 21b are formed on the upper and lower edges of the groove of the movable plug 21, respectively, so that air pressure is received in the pressure chamber 20b. In the present embodiment, the area of the first pressure receiving surface 21a is formed to be larger than the area of the second pressure receiving surface 21b, and the movable plug 21 is configured to operate by the difference in the pressure receiving area. That is, when the air pressure in the pressure chamber 20b increases, a force that tends to slide the movable plug 21 in a direction away from the piston 16 acts, and when the force overcomes the urging force of the compression spring 22, the movable plug 21 Is designed to slide backwards.

Therefore, when the air pressure in the pressure chamber 20b (that is, the combustion chamber 12) exceeds a certain level, the movable plug 21 slides to open the second opening 20c. When the second opening 20c is opened, the combustion chamber 12 and the space behind the piston 16 communicate with each other, so that the air (combustion gas) in the combustion chamber 12 flows into the rear of the piston 16. Specifically, when the combustible gas burns in the combustion chamber 12 and the pressure in the combustion chamber 12 rises, the movable plug 21 slides and the combustion gas flows into the rear of the piston 16, and the combustion pressure causes the piston 16 to move. It is configured to drive.

The grip 30 is a portion connected to the lower surface of the output unit 11, and is arranged so as to be substantially orthogonal to the launching direction of the fastener. The user of the gas combustion type driving tool 10 is formed so that the tool can be stably held by gripping the grip 30.

The grip 30 is provided with a trigger operation unit 31 that can be pulled. The trigger operation unit 31 is arranged at a position where the index finger rests when the grip 30 is gripped. When the trigger operation unit 31 is operated, the trigger switch 32 arranged inside the grip 30 is pressed and turned on. The signal output from the turned-on trigger switch 32 is transmitted to the control device 33 arranged inside the grip 30 and processed. Specifically, the control device 33 executes a predetermined driving operation if both the safety switch and the trigger switch 32 described above are in the ON state (the driving operation will be described in detail later).

Further, a battery mounting portion 34 to which the battery pack 50 can be attached and detached is provided on the lower end surface of the grip 30. Since the gas combustion type driving tool 10 according to the present embodiment is driven by the electric power supplied from the battery pack 50 having a built-in secondary battery, the gas combustion type driving tool 10 is used in a state where the battery pack 50 is mounted on the battery mounting portion 34. In the present embodiment, the battery pack 50 is configured to be slid from the rear and mounted on the battery mounting portion 34. Further, the battery pack 50 is configured to be slid rearward so that it can be removed from the battery mounting portion 34.

The gas can storage unit 37 is a portion for mounting a gas can, which is a source of combustible gas supplied to the combustion chamber 12. As shown in FIG. 3, the gas can storage portion 37 according to the present embodiment is formed in a cylindrical shape and is arranged in front of the grip 30. Further, the gas can storage portion 37 is arranged so that the central axis is substantially parallel to the grip 30.

The gas can storage portion 37 according to the present embodiment is provided on the front side of the cylinder portion 37a for slidably holding the gas can, the connection portion 37b provided at the innermost part of the cylinder portion 37a, and the cylinder portion 37a. It is provided with a closed lid portion 37d.

The connecting portion 37b is a portion for connecting the nozzle of the gas can. The connecting portion 37b is connected to a first gas pipeline 46, which will be described later. By connecting the nozzle of the gas can to the connecting portion 37b, the combustible gas in the connected gas can can be guided to the combustion chamber 12.

The lid portion 37d is attached to the gas can storage portion 37 so as to be openable and closable. Specifically, the lid portion 37d is rotatably supported by the gas can storage portion 37 via a hinge 37c so that the inside of the gas can storage portion 37 can be opened or sealed by rotating. It has become. By opening the lid portion 37d, the gas can housed in the gas can storage portion 37 can be taken out, or the gas can can be inserted into the gas can storage portion 37.

The magazine 38 is for loading a plurality of stampable fasteners, and is connected below the nose portion 18. The fasteners loaded in the magazine 38 are sequentially supplied to the nose portion 18, and the leading fastener supplied to the nose portion 18 is hit by the driver 17 to be launched. The magazine 38 according to the present embodiment can accommodate the connecting fasteners aligned in a straight line.

The coupler 40 is for connecting a hose plug or the like connected to an air supply source such as an air compressor and taking in compressed air from the outside. The coupler 40 is arranged on the lower end side of the grip 30, and more specifically, is arranged below the position of the grip 30 that can be gripped by the user. Further, the coupler 40 is open downward. The gas combustion type driving tool 10 according to the present embodiment sends compressed air supplied from the outside through the coupler 40 to the combustion chamber 12 and is used for driving the fastener.

As shown in FIG. 2, the coupler 40 is provided at a position offset to the side (left side when viewed from the user who grips the grip 30) when viewed from the grip 30. Specifically, it is provided on the side of the gas can storage portion 37. Further, the coupler 40 is arranged so as to be displaced forward from the battery mounting portion 34. In this way, the coupler 40 is arranged offset with respect to the battery mounting portion 34 and the gas can accommodating portion 37, is arranged close to the battery mounting portion 34 and the gas can accommodating portion 37, and is arranged in close proximity to the battery mounting portion 34 and the gas can accommodating portion 37. It is arranged so as not to interfere with the gas can storage portion 37. Therefore, the parts requiring attachment / detachment such as the battery mounting portion 34, the gas can storage portion 37, and the coupler 40 are collectively arranged on the lower end side of the grip 30, and the operability is good. In addition, since these are arranged compactly, the machine does not become large and easy to handle.

Further, as shown in FIG. 1, the coupler 40 is provided so as not to protrude downward from the battery pack 50 mounted on the battery mounting portion 34. Therefore, since the coupler 40 does not protrude from the outline of the tool, the maneuverability of the tool is good when the hose is connected. Further, since the coupler 40 is arranged inside the outline of the tool, the coupler 40 is less likely to come into contact with the ground when the tool is placed on the ground, and dust and the like are less likely to adhere to the coupler 40. It has become.

Next, the introduction path of the compressed air and the combustible gas into the combustion chamber 12 will be described.

The compressed air supplied from the outside is introduced into the tool via the coupler 40 as described above. The gas combustion type driving tool 10 according to the present embodiment includes a pipeline for connecting the coupler 40 and the combustion chamber 12. Specifically, the first air pipeline 42 that constitutes the introduction path from the coupler 40 to the air injection valve 41 (described later) and the second air pipeline that constitutes the introduction path from the air injection valve 41 to the combustion chamber 12. 43 and.

The first air pipeline 42 is a pipe whose upstream end is connected to the coupler 40 and its downstream end is connected to the air injection valve 41. As shown in FIGS. 1 and 8, the first air pipeline 42 is arranged on the upstream side along the side surface of the gas can accommodating portion 37. Further, the downstream side of the first air pipeline 42 is arranged along the side surface of the output unit 11. Since the gas can storage unit 37 and the output unit 11 are connected in a substantially L shape, the first air pipeline 42 is refracted in an L shape at the connection point between the gas can storage unit 37 and the output unit 11. .. The first air pipeline 42 according to the present embodiment is formed of an elastically bendable tube.

Further, the first air pipeline 42 is partially exposed and attached to the outside of the housing of the tool. Specifically, the first air pipeline 42 penetrates the tunnel-shaped pipeline holding portion 37e provided on the side surface of the gas can accommodating portion 37, and extends to the pipeline cover portion 25 provided on the side surface of the output unit 11. It is inserted and the other parts are exposed to the outside. According to such a configuration, since the first air pipeline 42 is inserted from the outside of the housing and assembled, the assembling property is good.

The air injection valve 41 is a solenoid valve that controls the amount of compressed air supplied to the combustion chamber 12. The air injection valve 41 measures the compressed air supplied through the first air pipeline 42 and injects a constant amount of compressed air into the combustion chamber 12. As shown in FIG. 6, the air injection valve 41 according to the present embodiment is arranged so as to be adjacent to the combustion chamber 12. Therefore, the distance of the second air pipe 43, which will be described later, can be set short, and the response of the machine can be improved.

The second air pipeline 43 is a pipe whose upstream end is connected to the air injection valve 41 and whose downstream end is connected to the combustion chamber 12. The second air pipeline 43 is for introducing the compressed air injected by the air injection valve 41 into the combustion chamber 12. As shown in FIGS. 6 and 8, the second air pipeline 43 is arranged so as to wrap around behind the cylinder head 14. As shown in FIGS. 5 and 7, the cylinder head 14 is provided with an air ejection portion 44 for connecting the second air pipeline 43, and the compressed air passing through the second air pipeline 43 is air. It flows into the inside of the combustion chamber 12 through the ejection portion 44.

The second air pipeline 43 according to the present embodiment is formed of an elastically bendable tube. As a result, even if vibration or impact is generated during the driving operation, it is difficult to be damaged or come off.

Further, as described above, the flammable gas in the gas can is introduced via the connecting portion 37b of the gas can accommodating portion 37. The gas combustion type driving tool 10 according to the present embodiment includes a pipeline for connecting the connection portion 37b and the combustion chamber 12. Specifically, the first gas pipe 46 that constitutes the introduction path from the connection portion 37b to the gas injection valve 45 (described later) and the second gas pipe that constitutes the introduction path from the gas injection valve 45 to the combustion chamber 12. A road 47 is provided.

The first gas pipeline 46 is a pipe whose upstream end is connected to the connecting portion 37b and whose downstream end is connected to the gas injection valve 45. As shown in FIG. 3, the first gas pipeline 46 is arranged along the output unit 11.
The gas injection valve 45 is a solenoid valve that controls the amount of combustible gas supplied to the combustion chamber 12. The gas injection valve 45 measures the combustible gas supplied through the first gas pipeline 46 and injects a certain amount of the combustible gas into the combustion chamber 12. As shown in FIG. 4, the gas injection valve 45 according to the present embodiment is arranged so as to be adjacent to the combustion chamber 12. Therefore, the distance of the second gas pipeline 47, which will be described later, can be set short, and the response of the machine can be enhanced.

The second gas pipeline 47 is a pipe whose upstream end is connected to the gas injection valve 45 and whose downstream end is connected to the combustion chamber 12. The second gas pipeline 47 is for introducing the combustible gas injected by the gas injection valve 45 into the combustion chamber 12. As shown in FIGS. 4 and 8, the second gas pipeline 47 is arranged so as to wrap around behind the cylinder head 14. As shown in FIG. 5, the cylinder head 14 is provided with a gas ejection portion 48 for connecting the second gas pipeline 47, and the combustible gas passing through the second gas pipeline 47 is a gas ejection portion. It flows into the inside of the combustion chamber 12 through 48. The second gas pipeline 47 according to the present embodiment is formed of an elastically bendable tube. As a result, even if vibration or impact is generated during the driving operation, it is difficult to be damaged or come off.

Next, the driving operation of the gas combustion type driving tool 10 according to the present embodiment will be described with reference to FIG.

When the trigger operation unit 31 is operated and the driving operation is started, the control device 33 first opens the gas injection valve 45 at the timing shown in FIG. 9A. Then, the gas injection valve 45 is opened until a predetermined time elapses, and when the predetermined time elapses, the gas injection valve 45 is closed at the timing shown in B. As a result, a predetermined amount of flammable gas is supplied into the combustion chamber 12.

Next, the control device 33 opens the air injection valve 41 at the timing shown in C of FIG. Then, the air injection valve 41 is opened until a predetermined time elapses, and when the predetermined time elapses, the air injection valve 41 is closed at the timing shown in D. As a result, a predetermined amount of compressed air is supplied into the combustion chamber 12.

When the combustible gas and the compressed air are introduced into the combustion chamber 12 to generate an air-fuel mixture, the control device 33 operates the ignition device 13 at the timing shown in E of FIG. 9, and ignites the air-fuel mixture. As a result, the pressure in the combustion chamber 12 rapidly increases. When the pressure in the combustion chamber 12 increases, the movable plug 21 operates and the combustion gas flows into the rear of the piston 16. As a result, the combustion pressure acts on the piston 16 to slide it, and the fastener 17 is launched by the driver 17 that slides integrally with the piston 16.

Here, the gas combustion type driving tool 10 according to the present embodiment can adjust the output related to the launching of the fastener by adjusting the filling pressure of the compressed air in the combustion chamber 12 and the filling pressure of the combustible gas. It is configured. Specifically, the output is adjusted by adjusting the opening time of the air injection valve 41 and the gas injection valve 45. The adjustment of the opening time of the air injection valve 41 and the gas injection valve 45 is realized by the control device 33 changing the energization time of the air injection valve 41 and the gas injection valve 45.

In the present embodiment, the user of the gas combustion type driving tool 10 can set the output in multiple stages. For example, as shown in FIG. 10, the output can be selected from three stages of "strong", "medium", and "weak". The gas combustion type driving tool 10 according to the present embodiment is provided with an operation unit 35 (see FIG. 3) such as a button and a knob for changing the output, and by operating this operation unit, user input can be performed. Get the based external parameters. Then, the output is adjusted with reference to this external parameter.

In the present embodiment, "medium" is the normal output, and the opening time of the air injection valve 41 and the gas injection valve 45 when set to "medium" is "1" which is a reference value. .. again,
When set to "strong", the opening time of the air injection valve 41 and the gas injection valve 45 is "1.2", which is 1.2 times the value of "medium". When set to "weak", the opening time of the air injection valve 41 and the gas injection valve 45 is "0.7", which is 0.7 times the value of "medium". As described above, in the present embodiment, both the opening time of the air injection valve 41 and the opening time of the gas injection valve 45 are configured to be longer in proportion to the output. In the present embodiment, the ratio between the opening time of the air injection valve 41 and the opening time of the gas injection valve 45 is configured to be constant regardless of the output, but is not limited to this. The ratio may be arbitrarily set according to the output.
The opening time of the air injection valve 41 and the opening time of the gas injection valve 45 determined in this way are used by the control device 33 for control in the driving operation shown in FIG. That is, after the gas ejection unit 48 is opened at the timing shown in A of FIG. 9, the control device 33 waits until the determined opening time of the gas injection valve 45 elapses, and when the opening time elapses, the control device 33 switches to B. The gas ejection unit 48 is closed at the indicated timing. Further, the control device 33 waits until the determined opening time of the air injection valve 41 elapses after opening the air injection valve 41 at the timing shown in C of FIG. 9, and when the opening time elapses, the control device 33 sets to D. The air injection valve 41 is closed at the indicated timing.

In the present embodiment, the output can be selected from multiple stages, but the present invention is not limited to this, and the output may be selected steplessly.

Further, in the above-described embodiment, the output can be selected from three stages of "strong", "medium", and "weak". May be selectable. Further, the nail to be used and the driving member may be made selectable by the user, and the output may be adjusted based on the preset parameters according to the selected conditions.

Further, the opening time of the air injection valve 41 and the opening time of the gas injection valve 45 according to the output set by the user may be further adjusted with reference to the usage environment of the machine. For example, environmental temperature, mechanical temperature, pressure for supplying compressed air to the air injection valve 41, pressure for supplying gas fuel to the gas injection valve 45, pressure in the pipeline, pressure in the combustion chamber 12, flow rate in the pipeline, etc. One or more factors such as power supply voltage may be obtained, and the opening time may be adjusted according to the result. By doing so, it is possible to always obtain a stable driving force even in different usage environments.

Further, in the present embodiment, an example in which the user changes the output has been described, but the present invention is not limited to this, and the machine may automatically change the output based on the input from the sensor.

For example, as shown in FIG. 11, as a sensor, a pressure sensor 49 may be provided on the downstream side of the air injection valve 41 and the gas injection valve 45. Then, when the pressure in the combustion chamber 12 (inside the pipeline) detected by the pressure sensor 49 reaches a preset predetermined pressure, the control device 33 closes the air injection valve 41 or the gas injection valve 45. You may do it.

In the above example, the pressure sensor 49 is provided on the downstream side of the air injection valve 41 and the gas injection valve 45, but the pressure sensor 49 is not limited to this and is arranged on the upstream side of the air injection valve 41 and the gas injection valve 45. You may.

Further, in the above example, an example in which the pressure sensor 49 is provided as a sensor has been described, but in addition to the pressure sensor 49 or in place of the pressure sensor 49, the air injection valve 41 is arranged in the flow path or gas injection. A flow sensor may be provided in the flow path in which the valve 45 is arranged. Then, when the flow rate detected by the flow rate sensor reaches a predetermined predetermined flow rate set in advance, the control device 33 may close the air injection valve 41 or the gas injection valve 45.

Further, in addition to the pressure sensor 49 and the flow sensor, or instead of the pressure sensor 49 and the flow sensor, a temperature sensor for detecting the environmental temperature may be provided. Then, the control device 33 may control the air injection valve 41 or the gas injection valve 45 to adjust the output by using the environmental temperature detected by the temperature sensor as an input parameter.

Further, in addition to (or instead of) the control as described above, the output may be adjusted by adjusting the supply pressure to the air injection valve 41 or the gas injection valve 45. For example, if the supply pressure to the air injection valve 41 or the gas injection valve 45 is unstable, the output is not stable, so that these supply pressures may be constant.

Specifically, the supply pressure to the gas injection valve 45 may be adjusted by changing the temperature of the gas can which is the supply source of the flammable gas. Since the vapor pressure of the gas fuel rises with the temperature, the supply pressure to the gas injection valve 45 also changes when the temperature of the gas can changes. When it is not desired to cause such a change, the supply pressure to the gas injection valve 45 can be stabilized by keeping the temperature of the gas can accommodating portion 37 constant. Further, the supply pressure to the gas injection valve 45 can be changed by intentionally changing the temperature of the gas can accommodating portion 37.

Further, the supply pressure to the air injection valve 41 may be adjusted by using the pressure reducing valve. Since the supply pressure to the air injection valve 41 depends on the internal pressure of the tank of the air compressor connected to the outside, when the internal pressure of the tank drops due to insufficient remaining amount of compressed air, the supply pressure to the air injection valve 41 also increases. descend. If it is not desired to cause such a change, if the compressed air supplied from the air compressor is supplied to the air injection valve 41 via the pressure reducing valve, the supply pressure can be made constant by the pressure reducing valve. Further, if the pressure reducing valve can be attached and detached, the supply pressure to the air injection valve 41 can be changed. When the pressure reducing valve is removable, for example, the coupler 40 may be provided with a pressure reducing valve attachment / detachment mechanism.

Further, in the above-described embodiment, the output is adjusted by adjusting the opening times of the air injection valve 41 and the gas injection valve 45, but in addition to (or instead of this), to the combustion chamber 12. The output may be adjusted by adjusting the flow path area of the flow path for supplying compressed air or flammable gas. For example, the flow rate of the compressed air or the combustible gas may be adjusted by adjusting the opening amount of the air injection valve 41 or the gas injection valve 45. Specifically, an air injection valve 41 or a gas injection valve 45 whose opening amount can be adjusted is used, and the flow rate is adjusted by adjusting the opening amount of the air injection valve 41 or the gas injection valve 45, whereby the combustion chamber is adjusted. The amount of compressed air or flammable gas supplied to 12 may be adjusted. In addition, the flow rate of compressed air or combustible gas may be adjusted by switching the flow path itself. Specifically, a plurality of pipelines having different areas are provided, and the flow rate is adjusted stepwise by switching which pipeline is to be communicated to the combustion chamber 12, whereby compressed air or combustible is supplied to the combustion chamber 12. The amount of sex gas may be adjusted.

Further, in addition to the control as described above, the output may be adjusted by changing the ignition timing. For example, as shown in FIG. 12, by accelerating the ignition timing (E'), ignition may be performed before the filling pressure in the combustion chamber 12 increases, thereby changing the output.

As described above, according to the present embodiment, the air injection valve 41 for injecting compressed air into the combustion chamber 12 and the gas injection valve 45 for injecting combustible gas into the combustion chamber 12 are provided. According to such a configuration, a large output can be obtained by the energy of the compressed air and the thermal energy of the combustion gas without making the volume of the combustion chamber 12 extremely large. Specifically, it is possible to obtain an output comparable to that of a gunpowder type driving tool with a machine size within a practical range as a hand-held tool. Moreover, unlike the gunpowder type driving tool, it can be used without a special license and maintenance is easy.

Then, by adjusting at least one of the filling pressure of the compressed air and the filling pressure of the combustible gas, the output related to the embossing of the fastener can be adjusted. According to such a configuration, since the filling pressure of the air-fuel mixture and the output energy are in a proportional relationship, the output can be adjusted accurately. In addition, the combustible gas can be burned in the most energy-efficient state regardless of the output setting, so that fuel is not wasted. Further, since the structure for adjusting the output mechanically is not required, the structure can be simple.

10 Gas combustion type driving tool 11 Output part 12 Combustion chamber 13 Ignition device 14 Cylinder head 15 Cylinder 16 Piston 17 Driver 18 Nose part 18a Injection port 20 Cylinder member 20a First opening 20b Pressure chamber 20c Second opening 21 Movable plug 21a 1st pressure receiving surface 21b 2nd pressure receiving surface 22 compression spring 25 pipeline cover part 30 grip 31 trigger operation part 32 trigger switch 33 control device 34 battery mounting part 35 operation part 37 gas can storage part 37a cylinder part 37b connection part 37c hinge 37d Lid 37e Pipe holding part 38 Magazine 40 Coupler 41 Air injection valve 42 First air pipe 43 Second air pipe 44 Air ejection part 45 Gas injection valve 46 First gas pipeline 47 Second gas pipeline 48 Gas ejection Part 49 Pressure sensor 50 Battery pack

Claims (4)

It is a gas combustion type driving tool that takes in compressed air from the outside and launches a fastener by the combustion pressure when igniting the mixture of combustible gas and compressed air supplied in the combustion chamber.
An air injection valve that injects compressed air into the combustion chamber,
A gas injection valve that injects flammable gas into the combustion chamber,
A pressure sensor located on the upstream side or the downstream side of the air injection valve,
Equipped with
A gas combustion type driving tool, characterized in that the output related to the launching of a fastener can be adjusted by adjusting the opening times of the air injection valve and the gas injection valve based on the detection result of the pressure sensor . The invention, wherein the opening time of the air injection valve or the gas injection valve is adjusted by changing the energization time or the amount of power supplied to at least one of the air injection valve or the gas injection valve. The gas combustion type driving tool according to 1 . The gas combustion type driving tool according to claim 1 or 2 , wherein the output is adjusted with reference to an external parameter based on a user input. The gas combustion type driving tool according to claim 3 , further comprising an operation unit for causing a user to input an output related to the punching of a fastener.

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