JP6794828B2 - Air duster structure and driving tool - Google Patents

Description

The present invention relates to an air duster structure for ejecting air from an ejection port using compressed air supplied from the outside, and a driving tool having an air duster structure.

Conventionally, an air duster gun or an air duster attached to a driving tool has been used to blow off fine wood chips and the like before driving a nail. For example, Patent Document 1 discloses a driving tool with an air duster. In the invention described in Patent Document 1, air is ejected from the ejection port by pressing an operation button for opening and closing the discharge valve. The operation buttons of the air duster are urged in the closing direction by a spring to prevent air leakage during non-operation.

Japanese Patent No. 3966080

In the conventional structure as described above, since it is necessary to operate the operation buttons against the spring force while using the air duster, there is a problem that the operating fingers hurt and easily get tired.

The operating load can be reduced by reducing the spring force for returning the operation button or by taking measures to weaken the spring force. However, when the spring force is weakened, the force for returning the operation button is also weakened, so that there is a possibility that air leakage during non-operation cannot be prevented. Therefore, there is a limit to weakening the spring force.

Therefore, it is an object of the present invention to provide an air duster structure capable of reducing the operating load without weakening the spring force for returning the operating portion and reducing the pain and tiredness of the operating finger. And.

The present invention has been made to solve the above-mentioned problems, and is characterized by the following.

The invention according to claim 1 is an air duster structure that ejects compressed air from an ejection port, and comprises a valve body that can move according to an external operation and a valve body urging member that urges the valve body in a closing direction. An operating unit that can be pushed against the urging force of the valve body urging member, a first pressure accumulator chamber and a second pressure accumulator chamber that are operably provided on the valve body, and the second pressure accumulator. A first throttle portion arranged upstream of the chamber and a second throttle portion arranged downstream of the second accumulator chamber are provided, and the movement of the valve body causes the first throttle portion or the first throttle portion or The amount of compressed air ejected from the ejection port can be adjusted by changing the flow rate of compressed air passing through the second throttle portion, and the valve body has a pressure receiving area in the first accumulator chamber. while being configured to be pushed in the opening direction by the difference of, in the second accumulation chamber is configured to be pushed in the closing direction by a difference in pressure receiving area, the flow passage area of the second diaphragm portion, said The valve body changes with the movement of the valve body, and the valve body is configured to pass through a predetermined switching position in which the magnitude relationship of the flow path area between the first throttle portion and the second throttle portion is reversed. From the closed position to the predetermined switching position, the flow path area of the first throttle portion is larger than the flow path area of the second throttle portion. the valve body, passes through the said predetermined switching position, by a flow passage area of the second diaphragm portion is larger than the flow passage area of the first throttle portion, said second accumulation chamber is depressurized It is characterized in that the load in the closing direction of the valve body is reduced.

The invention according to claim 2 is an air duster structure that ejects compressed air from an outlet, and has a valve body that can move according to an external operation and a valve body urging member that urges the valve body in a closing direction. An operation unit that can be pushed against the urging force of the valve body urging member, a first pressure accumulator chamber and a second pressure accumulator chamber that are operably provided on the valve body, and the second pressure accumulator chamber. A first throttle portion arranged upstream of the pressure accumulator chamber and a second throttle portion arranged downstream of the second pressure accumulator chamber are provided, and the first throttle portion is moved by the movement of the valve body. Alternatively, the flow rate of compressed air passing through the second throttle portion can be changed to adjust the amount of air ejected from the ejection port, and the valve body receives pressure in the first accumulator chamber. It is configured to be pushed in the opening direction due to the difference in area, and is also configured to be pushed in the closing direction due to the difference in pressure receiving area in the second accumulator chamber, and the flow path resistance of the second throttle portion is The valve body changes with the movement of the valve body, and the valve body is configured to pass through a predetermined switching position in which the magnitude relationship of the flow path resistance between the first throttle portion and the second throttle portion is reversed. The flow path resistance of the second throttle portion is larger than the flow path resistance of the first throttle portion until the valve body reaches the predetermined switching position from the closed position. said valve body, passes through the said predetermined switching position, the flow path resistance of the second narrowed portion is smaller than the flow path resistance of the first throttle portion, said second accumulation chamber is vacuum Therefore, the load in the closing direction of the valve body is reduced.

The invention according to claim 3 is provided with the second accumulator chamber downstream of the first accumulator chamber, in addition to the feature points of the invention according to claim 1 or 2 , wherein the first accumulator chamber is provided. The throttle portion is characterized in that the first accumulator chamber and the second accumulator chamber are provided so as to communicate with each other.

The invention according to claim 4 has an operating load that momentarily increases immediately before the valve body passes through the predetermined switching position, in addition to the feature points of the invention according to any one of claims 1 to 3. It is characterized in that it is configured to do so.

The invention according to claim 5 is provided with the air duster structure according to any one of claims 1 to 4 , and is characterized in that a fastener is punched out using the compressed air.

The invention according to claim 1 or 2 is as described above, and the valve body is configured to be pushed in the opening direction in the first accumulator chamber and in the closing direction in the second accumulator chamber. When the body passes through a predetermined switching position while moving from the closed position to the fully open position, the second accumulator chamber is configured to depressurize and reduce the load in the valve body closing direction. ..

According to such a configuration, when the valve body is closed, the sealing property can be enhanced by the force in the closing direction and the spring force received by the valve body in the second accumulator chamber. Further, as the valve body opens, the second throttle portion becomes larger, and when the amount of air flowing out from the second throttle portion exceeds the amount of air flowing in from the first throttle portion, the second throttle portion is used. The amount of air flowing into the accumulator chamber cannot keep up with the amount of air flowing out of the accumulator chamber, and as a result, the pressure in the second accumulator chamber is reduced. In this way, when the predetermined switching position is passed, the second accumulator chamber is depressurized and the load in the direction of closing the valve body is reduced. Therefore, when the valve body is open and passes through a predetermined switching position, the operating load can be reduced by reducing the force received by the valve body in the closing direction in the second accumulator chamber. In other words, the operating load can be reduced without weakening the spring force for returning the operating portion, and the pain and tiredness of the operating finger can be reduced.

Since the spring force increases in proportion to the pushing amount (compression amount), the maximum operating load should be reduced by reducing the load received by the valve body in the closing direction in the latter half of the opening of the valve body. Can be done. Further, once the operation unit is pushed all the way in, the operation load becomes lighter, so that problems such as finger pain and tiredness caused by continuing to push the operation part can be effectively solved.

Further, the invention according to claim 1 is as described above, and the magnitude relationship between the flow path areas of the first throttle portion and the second throttle portion is reversed before and after the valve body passes through the predetermined switching position. To do. According to such a configuration, the pressure balance can be changed by changing the flow path area. Specifically, when the valve body opens from the closed position, the air flow is throttled by the second throttle portion until it moves to the predetermined switching position, so that it is upstream from the second throttle portion. The pressure in the second accumulator chamber in is not easily affected by the air flow. On the other hand, when the valve body is further opened from the predetermined switching position, the air flow is throttled by the first throttle portion, so that the amount of air flowing out is larger than the air flowing into the second accumulator chamber. As a result, the pressure in the second accumulator chamber decreases, and the force acting in the direction of closing the valve body decreases.

Further, the invention according to claim 2 is as described above, and the magnitude relationship of the flow path resistance between the first throttle portion and the second throttle portion is reversed before and after the valve body passes through the predetermined switching position. To do. According to such a configuration, the pressure balance can be changed by changing the flow path resistance. Specifically, when the valve body opens from the closed position, the air flow is throttled by the second throttle portion until it moves to the predetermined switching position, so that it is upstream from the second throttle portion. The pressure in the second accumulator chamber in is not easily affected by the air flow. On the other hand, when the valve body is further opened from the predetermined switching position, the air flow is throttled by the first throttle portion, so that the amount of air flowing out is larger than the air flowing into the second accumulator chamber. As a result, the pressure in the second accumulator chamber decreases, and the force acting in the direction of closing the valve body decreases.

Further, the invention according to claim 3 is as described above, the second accumulator chamber is provided downstream of the first accumulator chamber, and the first throttle portion is the first accumulator chamber and the second accumulator chamber. It is provided so as to communicate with the accumulator chamber. According to such a configuration, when the valve body opens from the closed position, the air flow path is throttled by the second throttle portion until it moves to the predetermined switching position, so that the second throttle portion The first accumulator chamber and the second accumulator chamber located upstream of the pressure chamber have almost the same pressure. On the other hand, when the valve body is further opened from the predetermined switching position, the air flow path is throttled by the first throttle portion, so that the air pressure in the upstream first accumulator chamber is higher than that in the second accumulator chamber. .. Therefore, the air pressure in the first accumulator chamber becomes relatively high at a certain point, and the force can be applied in the direction of opening the valve body.

Further, the invention according to claim 4 is as described above, and the operating load is configured to increase momentarily immediately before the valve body passes a predetermined switching position. According to such a configuration, the operating load is momentarily increased, so that the user can recognize the passage of the predetermined switching position. That is, since the user can prepare his / her mind, it is possible to prevent the operating load from suddenly becoming light and over-operating.
Further, the invention according to claim 5 is as described above, and a driving tool having an air duster structure can be provided.

It is a right side view of a driving tool provided with an air duster structure. It is a left side view of the driving tool provided with an air duster structure. It is a cross-sectional view of AA of a driving tool. It is a left side view of the driving tool which removed the tip cover member and the side cover member. It is (a) a perspective view seen from the back side and (b) a perspective view seen from the front side of the tip cover member. It is a perspective view which looked at the driving tool from the bottom. It is sectional drawing of the flow rate adjustment mechanism, and is the figure of the state in which the operation part is not operated. It is sectional drawing of the flow rate adjustment mechanism, and is the figure of the state in which the operation part was operated halfway. It is sectional drawing of the flow rate adjustment mechanism, and is the figure of the state in which the operation part was operated all the way. It is a graph which shows the reduction effect of an operating load. It is sectional drawing of the flow rate adjustment mechanism which concerns on modification 1. FIG. It is a partially enlarged cross-sectional view of the flow rate adjustment mechanism which concerns on modification 1, (a) the figure in which the operation part was operated halfway, and (b) the figure in the state where the operation part was operated all the way. It is a graph which shows the reduction effect of the operation load which concerns on modification 1. It is sectional drawing of the flow rate adjustment mechanism which concerns on modification 2. FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiment, as an example of using the air duster structure, a driving tool 10 having an air duster structure is given as an example, but the present invention is not limited to this, and the air duster structure according to the present embodiment is applied to other tools and the like. May be good. For example, the air duster structure according to the present embodiment may be applied to the air duster gun.

The driving tool 10 according to the present embodiment uses compressed air supplied from the outside to launch a fastener, and has an air duster structure that ejects air from the ejection port 17b using the compressed air supplied from the outside. It has. By providing the driving tool 10 with an air duster structure in this way, it is possible to perform driving with a fastener and cleaning with an air duster without having to change the tool.

As shown in FIG. 1, the driving tool 10 is operably provided on a tool body 11 having a striking mechanism inside, a grip 12 provided so as to project in a direction orthogonal to the tool body 11, and a grip 12. The trigger 13 is provided, the nose portion 14 is provided so as to protrude from the tip of the tool body 11, the magazine 15 is connected to the rear of the nose portion 14, and the air duster structure can be pressed to operate. The operation unit 30 is provided.

The striking mechanism built into the tool body 11 operates the driver by utilizing the force of compressed air. The driver is movable in the direction of the nose portion 14 in order to launch the fastener, and moves in the driving direction of the fastener when the striking mechanism generates an impact force. The driver who has moved in the driving direction launches the fastener set in the nose portion 14. The fastener punched out by the driver is ejected from the injection port 14a opened at the tip of the nose portion 14.

When the driving tool 10 is used, the grip 12 is gripped and gripped, the injection port 14a is pressed against the driving member, and then the trigger 13 is pulled. By this operation, the striking mechanism described above is activated and the fastener is launched.

A connecting fastener is housed in the magazine 15, and the leading fastener of the connecting fastener is sequentially supplied in the direction of the nose portion 14 (directly below the driver before the driving operation).

The compressed air for operating the striking mechanism and the air duster structure described above is supplied from an air supply source such as an air compressor. Specifically, an air supply air hose connected to a compressor or the like is connected to an end cap portion 16 provided at the rear end of the grip 12, and compressed air is supplied via the air hose. The compressed air supplied from the end cap portion 16 passes through the air supply path formed inside the grip 12 and is supplied to the striking mechanism or the air duster structure.

In the striking mechanism, when the trigger 13 is operated, compressed air is supplied into the striking cylinder, and this compressed air acts on the striking piston to drive the striking piston, and the driver coupled to the striking piston pushes the nail. Hit.

In the air duster structure, when the operation unit 30 is operated, compressed air is ejected from the ejection port 17b that opens near the nose portion 14. As shown in FIG. 1, the operation unit 30 according to the present embodiment is arranged at a position where the operator can operate the grip 12 by the hand holding the grip 12. Specifically, when the grip 12 is gripped by the right hand, it is arranged at a position where it can be operated by the thumb of the right hand.

As shown in FIGS. 3 and 4, the above-mentioned air duster structure includes a flow rate adjusting mechanism provided inside the housing of the tool body 11. An air outlet 40 for taking out air to the outside of the housing is provided on the downstream side of the flow rate adjusting mechanism. A duster pipe 42 extending in the direction of the tip of the tool body 11 (that is, the direction of the nose portion 14) is connected to the air outlet 40. More specifically, the duster pipe 42 is connected to the air outlet 40 via a joint component 41 rotatably provided.

The air outlet 40 is arranged on the side surface of the tool body 11 on the side opposite to the operation unit 30. The duster pipe 42 and the joint component 41 connected to the air outlet 40 are arranged outside the housing of the tool body 11, but as shown in FIG. 2, the tip cover member 17 covering the tip of the tool body 11 , And a side cover member 18 arranged at a position covering the air outlet 40.

As shown in FIG. 5, a pipe holding portion 17a for holding the tip portion 42a of the duster pipe 42 is provided on the back surface side of the tip cover member 17, so that the tip portion 42a of the duster pipe 42 covers the tip portion 42a. It is fixed by the member 17. Since the duster pipe 42 is a flexible tube made of resin or the like and can be elastically deformed, it can be easily assembled to the pipe holding portion 17a.

Further, as shown in FIGS. 5 and 6, an air ejection port 17b is opened on the surface side of the tip cover member 17. The air ejection port 17b communicates with the above-mentioned pipe holding portion 17a. By providing the tip cover member 17 with an air ejection port 17b communicating with the duster pipe 42 in this way, air is ejected from the ejection port 17b when the operation unit 30 is operated. ..

The above-mentioned flow rate adjusting mechanism is for adjusting the amount of air ejected from the ejection port 17b, and as shown in FIGS. 7 to 9, a pipeline forming portion forming a pipeline 23 for circulating air. 20 and a movable valve body 31 arranged in the pipeline 23, an operation unit 30 operably arranged at the tip of the valve body 31, and a valve body urging to urge the valve body 31 in the protruding direction. A member 36 is provided. This flow rate adjusting mechanism can introduce compressed air from the upstream side, and when an air supply source such as an air compressor is connected, compressed air is always supplied to the upstream side. Further, an air outlet 40 to which the duster pipe 42 (joint component 41) can be connected is opened on the downstream side of the flow rate adjusting mechanism.

The pipeline forming portion 20 has a hollow portion forming the pipeline 23, and is configured to take compressed air into the pipeline 23 from the upstream opening 21 that opens on the upstream side. Specifically, the compressed air flowing in from the upstream opening 21 passes through the two openings of the first inflow port 25 and the second inflow port 26 and flows into the periphery of the valve body 31. The compressed air that has flowed into the pipeline 23 from the second inflow port 26 passes through the tapered opening 27, which will be described later, and flows to the air outlet 40.

The tapered opening 27 is provided on the downstream side of the upstream opening 21, and when the valve body 31 moves, the clearance amount between the pipeline 23 and the valve body 31 is gradually changed to change the pipeline 23. It is for controlling the flow rate of the air inside. The tapered opening 27 is formed in a tapered shape in which the opening gradually increases toward the downstream side, and is configured to increase the clearance amount when the valve body 31 moves in the direction of opening the pipeline 23. ing.

The valve body 31 is configured to slide in conjunction with the pressing operation of the operation unit 30. In the natural state, the valve body 31 is urged in the protruding direction by the valve body urging member 36, but when the operation unit 30 is pushed in against the urging force of the valve body urging member 36. , The valve body 31 moves in the direction of opening the pipeline 23. In the present embodiment, a tip sealing member 32 formed of an O-ring or the like is attached to the tip of the valve body 31, and in a natural state, the tip sealing member 32 abuts on the tapered opening 27 described above. The pipeline 23 is in a closed state. Further, when the valve body 31 moves in the direction of opening the pipeline 23, a clearance is generated between the tip seal member 32 and the tapered opening 27, and this clearance controls the flow rate of air in the pipeline 23. It has become. Then, when the valve body 31 opens the pipeline 23, air is discharged from the air outlet 40, and air is ejected from the ejection port 17b. In this embodiment, since the valve body 31 and the air outlet 40 are arranged along the pushing direction of the operation unit 30, it is not necessary to arrange the duster pipe 42 inside the housing. There is.

By the way, inside the pipeline forming portion 20, as shown in FIGS. 7 to 9, a first pressure accumulator chamber R1 operably provided on the valve body 31 and a first pressure accumulator chamber R1 operably acting on the valve body 31. A second throttle chamber R2 provided downstream of the pressure accumulator chamber R1, a first throttle portion S1 for communicating the first accumulator chamber R1 and the second accumulator chamber R2, and a second accumulator chamber R2. A second throttle portion S2 arranged downstream is provided.

In the present embodiment, the second accumulator chamber R2 is provided downstream of the first accumulator chamber R1, and the first throttle portion S1 is the first accumulator chamber R1 and the second accumulator chamber R2. However, the embodiment of the present invention is not limited to this. For example, as shown in FIG. 14, the space divided by the first inflow port 25 can be defined as the first accumulator chamber R1. In this case, the first accumulator chamber R1 and the second accumulator chamber R2 are not in an upstream-downstream relationship, and the first throttle portion S1 connects the first accumulator chamber R1 and the second accumulator chamber R2. It is not something that can be communicated.

The first accumulator chamber R1 is a space provided between the upstream opening 21 and the first throttle portion S1. The first accumulator chamber R1 includes a first inflow port 25. In other words, the compressed air in the first accumulator chamber R1 passes through the first inflow port 25 and flows into the periphery of the valve body 31. Therefore, the pressure of the compressed air in the first accumulator chamber R1 acts on the valve body 31.

The first accumulator chamber R1 adjusts the area where the compressed air acts on the valve body 31, so that the difference in the pressure receiving area of the valve body 31 in the first accumulator chamber R1 when the compressed air is introduced. The valve body 31 is configured to be pushed in the opening direction. In other words, the valve body 31 is configured to be pushed in the opening direction due to the difference in the pressure receiving area when the compressed air is introduced into the first accumulator chamber R1.

Specifically, in the first pressure accumulator chamber R1, the diameter of the intermediate seal member 33 is made larger than the diameter of the base seal member 34, so that the valve body 31 opens in the opening direction (using the difference in pressure receiving area between the two). The load is received in the downward direction of FIGS. 7 to 9.

The second accumulator chamber R2 is a space provided between the first throttle portion S1 and the second throttle portion S2. The compressed air in the second accumulator chamber R2 passes through the second inflow port 26 and flows into the periphery of the valve body 31, so that the pressure of the compressed air in the second accumulator chamber R2 is the valve. It is designed to act on the body 31. The second accumulator chamber R2 is separated from the first accumulator chamber R1 by an intermediate seal member 33 attached to the outer periphery of the valve body 31. In other words, the first accumulator chamber R1 and the second accumulator chamber R2 are arranged adjacent to each other on the outer peripheral surface of the valve body 31 with the intermediate seal member 33 interposed therebetween.

The second accumulator chamber R2 adjusts the area in which the compressed air acts on the valve body 31, so that the difference in the pressure receiving area of the valve body 31 in the second accumulator chamber R2 when the compressed air is introduced. The valve body 31 is configured to be pushed in the closing direction. In other words, the valve body 31 is configured to be pushed in the closing direction due to the difference in the pressure receiving area when the compressed air is introduced into the second accumulator chamber R2.

Specifically, in the second pressure accumulator chamber R2, by making the diameter of the intermediate seal member 33 larger than the diameter of the tip seal member 32, the valve body 31 is closed in the closing direction (using the difference in pressure receiving area between the two). The load is received in the upward direction of FIGS. 7 to 9.

The first throttle portion S1 is provided at the entrance portion of the second accumulator chamber R2, and is throttled so that the flow path area is smaller than that of the first accumulator chamber R1 and the second accumulator chamber R2. It has a shape. In the present embodiment, the second inflow port 26 forms the first throttle portion S1, and the first throttle portion S1 is provided between the first accumulator chamber R1 and the second accumulator chamber R2. ing.

The second throttle portion S2 is provided at the outlet of the second pressure accumulator chamber R2, and in the present embodiment, the second throttle portion S2 is provided by the clearance formed by the tip seal member 32 and the taper opening 27 described above. The throttle portion S2 is formed. Therefore, the second throttle portion S2 is configured so that the clearance amount is variable.

The first throttle portion S1 and the second throttle portion S2 described above are the first until the valve body 31 passes a predetermined switching position (until the operation amount (movement amount) of the valve body 31 reaches a predetermined amount). The flow path area of the throttle portion S1 of 1 is configured to be larger than the flow path area of the second throttle portion S2, and after the valve body 31 has passed a predetermined switching position, the flow path area of the first throttle portion S1 The flow path area is configured to be smaller than the flow path area of the second throttle portion S2.

Here, the predetermined switching position is a predetermined position through which the valve body 31 passes from the closed position to the completely open position, and the size of the throttle (flow path area) as described above is large or small. This is the position of the valve body 31 at the timing when the relationship is reversed.

Explaining in detail the change when the valve body 31 passes through the predetermined switching position, as shown in FIG. 8, until the valve body 31 reaches the predetermined switching position from the closed position as shown in FIG. The flow path area of the first throttle portion S1 is larger than the flow path area of the second throttle portion S2. Therefore, the first throttle portion S1 can flow more air than the second throttle portion S2, and the air flow is most throttled in the second throttle portion S2. .. In this state, the first accumulator chamber R1 and the second accumulator chamber R2 have substantially the same pressure, and the load for pushing the valve body 31 in the opening direction by the compressed air in the first accumulator chamber R1 and the load. The load for pushing the valve body 31 in the closing direction by the compressed air in the second accumulator chamber R2 is substantially the same.

On the other hand, when the valve body 31 passes through the predetermined switching position, as shown in FIG. 9, the flow path area of the second throttle portion S2 increases, so that the flow path area of the first throttle portion S1 becomes the second. It is smaller than the flow path area of the throttle portion S2 of. Therefore, the air flow is most throttled in the first throttle portion S1. In this state, the pressure in the second accumulator chamber R2 on the downstream side of the first throttle portion S1 is reduced, so that the pressure becomes lower than the pressure in the first accumulator chamber R1, that is, the valve body 31 is pushed in the opening direction. The load of is larger than the load for pushing the valve body 31 in the closing direction.

According to such a configuration, as shown in FIG. 10, when the predetermined switching position (P) is passed, the air pressure for moving the valve body 31 in the opening direction increases, so that the operating load is reduced. In the conventional structure not provided with such a configuration, as shown in the “conventional” graph of FIG. 10, the spring load increases in proportion to the operation amount, so that when the operation unit 30 is operated to the innermost part. The operating load peaks at.

According to the present embodiment, when the valve body 31 opens from the closed position, the air flow path is throttled by the second throttle portion S2 until it moves to the predetermined switching position, so that the second throttle The first accumulator chamber R1 and the second accumulator chamber R2 located upstream of the portion S2 have substantially the same pressure. On the other hand, when the valve body 31 is further opened from the predetermined switching position, the air flow path is throttled by the first throttle portion S1, so that the upstream first pressure accumulator chamber R1 is larger than the second pressure accumulator chamber R2. The air pressure rises. Therefore, when the operation unit 30 is operated, the pressure balance between the first accumulator chamber R1 and the second accumulator chamber R2 suddenly changes at a certain point. Specifically, the air pressure in the first accumulator chamber R1 becomes relatively high at a certain point, and a force acts in the direction of opening the valve body 31.

According to such a configuration, the pushing force in the opening direction of the valve body 31 is weak before passing through the predetermined switching position, and the pushing force in the opening direction of the valve body 31 is strong after passing through the predetermined switching position. Loads can be applied to act. Therefore, when the valve body 31 is close to the closed position, the sealing property can be improved without canceling the spring force, and when the valve body 31 is close to the open position, the spring force can be canceled to reduce the operating load. In other words, the operating load can be reduced without weakening the spring force for returning the operating unit 30, and the pain and tiredness of the operating finger can be reduced.

Since the spring force acting in the closing direction of the valve body 31 increases in proportion to the pushing amount (compression amount), the operating load increases as the valve body 31 is opened. Therefore, the maximum value of the operating load can be reduced by configuring the load acting in the direction of closing the valve body 31 to decrease in the latter half of the opening of the valve body 31. Further, once the operation unit 30 is pushed all the way in, the operation load becomes lighter, so that problems such as finger pain and tiredness caused by continuing to push the operation unit 30 can be effectively solved.

In the above embodiment, before and after the valve body 31 passes through the predetermined switching position, the magnitude relationship of the flow path area between the first throttle portion S1 and the second throttle portion S2 is reversed. As a result, the pressure balance between the first accumulator chamber R1 and the second accumulator chamber R2 is changed rapidly, but the present invention is not limited to this. For example, by adjusting the relative length and opening shape of the first throttle portion S1 and the second throttle portion S2, the first throttle portion S1 before and after the valve body 31 passes through the predetermined switching position. The magnitude relationship between the flow path resistance and the second throttle portion S2 may be reversed.

Further, the operating load may be momentarily increased immediately before the valve body 31 passes through the predetermined switching position. For example, as shown in FIGS. 11 and 12, a protrusion 24 may be provided in the pipeline 23 so that the protrusion 24 is overcome when the valve body 31 passes through a predetermined switching position. It is needless to say that the protrusion 24 is only an example, and various configurations such as a known snap-fit shape can be used as a configuration for instantaneously increasing the operating load. According to such a configuration, as shown in FIG. 13, the operating load momentarily increases when passing through the predetermined switching position (P), so that the user is made to recognize the passage of the predetermined switching position. Can be done. That is, since the user can prepare his / her mind, it is possible to prevent the operating load from suddenly becoming light and over-operating.

10 Driving tool 11 Tool body 12 Grip 13 Trigger 14 Nose part 14a Injection port 15 Magazine 16 End cap part 17 Tip cover member 17a Piping holding part 17b Piping port 18 Side cover member 20 Pipeline forming part 21 Upstream opening 23 Pipe Road 24 Protrusion 25 1st inflow port 26 2nd inflow port 27 Tapered opening 30 Operation part 31 Valve body 32 Tip sealing member 33 Intermediate sealing member 34 Base sealing member 36 Valve body urging member 40 Air outlet 41 Joint part 42 Duster Piping 42a Tip R1 First accumulator chamber R2 Second accumulator chamber S1 First throttle S2 Second throttle

Claims (5)

It has an air duster structure that ejects compressed air from the outlet.
A valve body that can be moved according to an external operation, a valve body urging member that urges the valve body in the closing direction, and an operation unit that can be pushed in against the urging force of the valve body urging member. A first accumulator chamber and a second accumulator chamber operably provided on the valve body, a first throttle portion arranged upstream of the second accumulator chamber, and a downstream of the second accumulator chamber. With a second diaphragm located in
The flow rate of compressed air passing through the first throttle portion or the second throttle portion is changed by the movement of the valve body, so that the amount of ejection from the ejection port can be adjusted.
The valve body is configured to be pushed in the opening direction due to the difference in the pressure receiving area in the first accumulator chamber, and is pushed in the closing direction due to the difference in the pressure receiving area in the second accumulator chamber. ,
The flow path area of the second throttle portion changes with the movement of the valve body,
The valve body is configured to pass through a predetermined switching position in which the magnitude relationship of the flow path area between the first throttle portion and the second throttle portion is reversed.
From the closed position to the predetermined switching position, the flow path area of the first throttle portion is larger than the flow path area of the second throttle portion.
Said valve body, passes through the said predetermined switching position, by a flow passage area of the second diaphragm portion is larger than the flow passage area of the first throttle portion, said second accumulation chamber is vacuum The air duster structure is characterized in that the load in the closing direction of the valve body is reduced. It has an air duster structure that ejects compressed air from the outlet.
A valve body that can be moved according to an external operation, a valve body urging member that urges the valve body in the closing direction, and an operation unit that can be pushed in against the urging force of the valve body urging member. A first accumulator chamber and a second accumulator chamber operably provided on the valve body, a first throttle portion arranged upstream of the second accumulator chamber, and a downstream of the second accumulator chamber. With a second diaphragm located in
The flow rate of compressed air passing through the first throttle portion or the second throttle portion is changed by the movement of the valve body, so that the amount of ejection from the ejection port can be adjusted.
The valve body is configured to be pushed in the opening direction due to the difference in the pressure receiving area in the first accumulator chamber, and is pushed in the closing direction due to the difference in the pressure receiving area in the second accumulator chamber. ,
The flow path resistance of the second throttle portion changes with the movement of the valve body,
The valve body is configured to pass through a predetermined switching position in which the magnitude relationship of the flow path resistance between the first throttle portion and the second throttle portion is reversed.
From the closed position to the predetermined switching position, the flow path resistance of the second throttle portion is larger than the flow path resistance of the first throttle portion.
Said valve body, passes through the said predetermined switching position, the flow path resistance of the second narrowed portion is smaller than the flow path resistance of the first throttle portion, said second accumulation chamber is vacuum The air duster structure is characterized in that the load in the closing direction of the valve body is reduced. The second accumulator chamber is provided downstream of the first accumulator chamber.
The air duster structure according to claim 1 or 2 , wherein the first throttle portion is provided so as to communicate the first accumulator chamber and the second accumulator chamber. The air duster structure according to any one of claims 1 to 3 , wherein the operating load is instantaneously increased immediately before the valve body passes through the predetermined switching position. A driving tool comprising the air duster structure according to any one of claims 1 to 4 , wherein the fastener is punched using the compressed air.

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