JP4400222B2 - Driving machine - Google Patents

Description

  The present invention relates to a driving machine driven by compressed air, and more particularly to a driving machine with improved driving response.

  2. Description of the Related Art Conventionally, there are driving machines for hitting fasteners such as nails and staplers using compressed air as a power source. Such a driving machine performs an impact by supplying compressed air to a piston upper chamber formed by a cylinder inner surface and a piston and abruptly displacing the piston. The compressed air is supplied from the outside and is temporarily stored in a pressure accumulating chamber formed in the frame of the driving machine. The pressure accumulating chamber and the piston upper chamber communicate with each other through a passage, and one or more valves for switching between communication and blocking are provided in the middle of the passage. These valves are configured to switch communication / blocking of the passage by supplying or discharging compressed air to or from a valve chamber which is a space adjacent to the valve. In general, the first valve is activated due to an external trigger operation, etc., and the next valve chamber is communicated with a passage that can be switched between communication and blockage by that operation, and these valves are generally operated sequentially. Is.

  Particularly in recent years, as described in, for example, Patent Document 1, the valve chamber is operated from a valve having a small capacity to a valve having a large capacity, and regardless of whether the operation of pulling the trigger is slow or slow, Many are configured to operate stably. Since the valve is sequentially operated by compressed air, the hammering is started after the trigger pulling operation and the operation of the push lever which is a contact portion to the driven material are performed in the step of driving the fastener. The time until the time depends greatly on the time required for the valves to operate sequentially.

  In order to shorten this time and increase the response, for example, Patent Document 2 proposes a structure that divides the main valve into two and uses the kinetic energy of the first valve to improve the operating speed of the second valve. Has been.

As another means, in Patent Document 3, by increasing the volume of the main valve chamber, which is the location where the main valve is accommodated, the main valve chamber is compressed when the main valve is raised and accommodated, and the air damper action is performed. A structure has been proposed in which no occurrence occurs.
Japanese Patent Publication No. 58-50833 Japanese Examined Patent Publication No.7-112673 JP 11-33930 A

  However, in the structure in which the main valve is divided into two, only the time for the second valve to move to the maximum displacement after the movement starts is shortened. After performing both the pulling operation of the trigger and the pressing operation of the push lever against the material to be driven, the time for the first valve to operate is not yet shortened, which is insufficient to increase the response.

  In the structure in which the volume of the main valve chamber is increased, the amount of compressed air stored in the main valve chamber increases. For this reason, the time for the compressed air in the main valve chamber to be discharged to the atmosphere becomes long, which hinders improvement in response. Therefore, the conventional driving machine is insufficient to obtain a satisfactory response.

  Also, a trigger valve outer frame portion that forms an outer shell and defines a trigger valve chamber, and the trigger valve outer frame portion and the trigger valve chamber based on the operation of the trigger and the contact of the push lever with the driven material. Trigger valve and main valve with a plunger that slides up and down through the passage and selectively communicates and blocks the passage from the accumulator chamber to the trigger valve chamber and the passage from the trigger valve chamber to the outside. Similarly, in the driving machine described above, there was a problem of response when discharging air from the main valve.

  As another conventional example, the main valve is not provided, but the trigger valve is provided so as to be slidable back and forth within the outer frame of the trigger valve, and one surface of the sliding direction faces the pressure accumulating chamber. There is a driving machine that further includes a valve piston that selectively communicates and blocks a passage that communicates from the piston upper chamber connected to the outer frame portion to the pressure accumulating chamber and a passage that communicates from the piston upper chamber to the atmosphere. With this driving machine, the air passage is selected according to the displacement of the valve piston, and the fastener is driven, etc., but the displacement speed of the valve piston is slow, and other controls are also performed due to the delay of the displacement of this valve piston. There may be a delay.

  Due to the above factors, there is a problem that the time lag from when the operator starts the driving operation to when the fastener is actually driven increases, resulting in poor response and difficulty in working. In addition, there is a problem that it is difficult to perform continuous hitting due to the time lag when it is desired to hit a large number of fasteners continuously in a short time.

  Therefore, an object of the present invention is to provide a driving machine that overcomes the above-described problems and improves the response in driving operation and the continuous quick hitting performance.

  In order to achieve the above object, a frame that internally defines a pressure accumulating chamber that stores compressed air, a cylindrical cylinder provided in the frame, and a piston that is slidably reciprocated in the cylinder, A push lever that contacts the workpiece, a trigger that is an operation input unit, and a cylinder that is slidable in a reciprocating manner. A main valve that alternatively forms a passage to the chamber and a passage to the atmosphere, a main valve chamber defining portion that defines a main valve chamber that houses the main valve, and the main valve from the pressure accumulation chamber A trigger valve that selectively communicates and blocks a passage to the chamber and a passage from the main valve chamber to the atmosphere, and a main valve control passage that extends from the main valve chamber and communicates with the trigger valve. A main valve control passage portion, wherein the trigger valve is provided so as to be slidable back and forth within the trigger valve outer frame portion which is an outer shell of the trigger valve and the trigger valve outer frame portion One surface of the pressure accumulation chamber faces the pressure accumulation chamber, and a passage communicating with the pressure accumulation chamber from the main valve control passage and a passage communicating with the atmosphere from the main valve control passage are selected in the outer frame of the trigger valve. A valve piston that communicates and shuts off in unison, and a plunger that penetrates the trigger valve outer frame and penetrates into the valve piston; and a penetrating portion where the plunger penetrates the trigger valve outer frame A trigger valve control passage is provided in the gap portion of the valve, a trigger valve chamber is defined by the other surface in the sliding direction of the valve piston and the outer frame of the trigger valve, and the plunger is connected to the trigger bar. Through the valve chamber, and slides up and down based on the operation of the trigger and the contact of the push lever with the driven material, and the passage from the pressure accumulation chamber to the trigger valve chamber and the atmosphere from the trigger valve chamber. In the driving machine that selectively connects and disconnects the passage to the main valve control passage, the value obtained by dividing the main valve chamber volume by the cross-sectional area of the main valve control passage is 1.0 or less and the main valve control passage Provided is a driving machine characterized in that a cross-sectional area of a passage passing through a trigger valve and communicating with the atmosphere is equal to or larger than a cross-sectional area of a main valve control passage.

  According to such a configuration, the compressed air is quickly exhausted from the main valve chamber. Further, the exhaust is not hindered in the passage communicating with the atmosphere via the trigger valve control passage. Further, if the value obtained by dividing the volume of the main valve chamber by the cross-sectional area of the main valve control passage is reduced to 0.8 or less or 0.6 or less, exhaust can be made faster.

  Further, a value obtained by dividing the volume of the trigger valve chamber by the cross-sectional area of the trigger valve control passage may be 0.20 or less. According to such a configuration, the exhaust of the compressed air from the trigger valve chamber is accelerated. Further, if the value obtained by dividing the volume of the trigger valve chamber by the cross-sectional area of the trigger valve control passage is reduced to 0.15 or less or 0.10 or less, the exhaust can be made faster.

  Further, the main valve control passage may be provided with a bent portion in the middle of the passage, and the bent portion may be formed in an arc shape or at least two refracting portions. Further, the bending angle of the bent portion may be 100 ° or more. According to such a configuration, the flow resistance in the main valve control passage can be reduced.

  Also, a frame defining a pressure accumulating chamber for storing compressed air, a cylindrical cylinder provided in the frame, a piston slidably reciprocated in the cylinder, and a material to be driven are contacted. A push lever, a trigger that is an operation input unit, a passage from the piston upper chamber to the pressure accumulating chamber, which is provided on the cylinder so as to be reciprocally slidable and defined by the upper surface of the piston and the inner surface of the cylinder, and the atmosphere. A main valve that alternatively forms a passage to the main valve chamber, a main valve chamber defining portion that defines a main valve chamber that houses the main valve, a passage from the pressure accumulation chamber to the main valve chamber, and the A trigger valve that selectively communicates and blocks the passage from the main valve chamber to the atmosphere, and a main valve control that defines a main valve control passage that extends from the main valve chamber and communicates with the trigger valve. The trigger valve includes a trigger valve outer frame portion that forms an outline of the trigger valve and defines a trigger valve chamber therein, an operation of the trigger, and the push Based on the contact of the lever with the material to be driven, it slides up and down through the trigger valve outer frame and the trigger valve chamber, and passes from the pressure accumulation chamber to the trigger valve chamber and from the trigger valve chamber. In a driving machine provided with a plunger that selectively communicates and blocks the passage to the atmosphere, the value obtained by dividing the volume of the main valve chamber by the cross-sectional area of the main valve control passage is 1.0 or less. There is provided a driving machine characterized in that a cross-sectional area of a passage communicating from the main valve control passage through the trigger valve to the atmosphere is equal to or larger than a cross-sectional area of the main valve control passage.

  According to such a configuration, in the driving machine including at least the main valve chamber, the exhaust of the compressed air from the main valve chamber is accelerated. Further, the passage communicating with the atmosphere via the trigger valve control passage has a cross-sectional area larger than the cross-sectional area of the trigger valve control passage, so that exhaust is not hindered by this passage. Further, if the value obtained by dividing the volume of the main valve chamber by the cross-sectional area of the main valve control passage is reduced to 0.8 or less or 0.6 or less, exhaust can be made faster.

  Further, the main valve control passage may be provided with a bent portion in the middle of the passage, and the bent portion may be formed in an arc shape or at least two refracting portions. Further, the bending angle of the bent portion may be 100 ° or more.

  Also, a frame that internally defines a pressure accumulating chamber that stores compressed air, a cylindrical cylinder provided in the frame, a piston that is slidably reciprocated in the cylinder, and a trigger that is an operation input unit And a trigger valve that selectively forms a passage from the piston upper chamber defined by the upper surface of the piston and the inner surface of the cylinder to the pressure accumulating chamber and a passage to the atmosphere. The trigger valve has a trigger valve outer frame portion that is an outer shell of the trigger valve, and is provided in the trigger valve outer frame portion so as to be slidable in a reciprocating manner. A valve piston for selectively communicating and blocking a passage communicating from the piston upper chamber connected to the trigger valve outer frame portion to the pressure accumulating chamber and a passage communicating from the piston upper chamber to the atmosphere; and the trigger valve outer frame Penetrate the part A trigger that is penetrated into the valve piston, and a trigger valve control passage is provided in a gap portion of a penetration portion through which the plunger penetrates the trigger valve outer frame, and the sliding direction of the valve piston A trigger valve chamber is defined by the other surface of the trigger valve and an outer frame portion of the trigger valve, and the plunger penetrates the trigger valve and slides up and down based on the operation of the trigger, from the pressure accumulation chamber to the trigger valve chamber. In the driving machine that selectively communicates and blocks the passage from the trigger valve chamber to the atmosphere, the value obtained by dividing the volume of the trigger valve chamber by the cross-sectional area of the trigger valve control passage is 0.20 or less. A driving machine characterized by the above is provided.

  According to such a configuration, in the driving machine including at least the valve piston, the compressed air is quickly exhausted from the trigger valve chamber. Further, if the value obtained by dividing the volume of the trigger valve chamber by the cross-sectional area of the trigger valve control passage is reduced to 0.15 or less or 0.10 or less, the exhaust can be made faster.

  A pressure accumulating chamber for storing compressed air; a cylindrical cylinder provided in the frame; a piston provided slidably in the cylinder; an upper surface of the piston; A main valve for communicating and blocking a passage from the piston upper chamber defined by the inner surface of the cylinder to the pressure accumulating chamber, and a main valve chamber defining portion for defining a main valve chamber for housing the main valve; A trigger valve that selectively communicates and blocks the passage from the pressure accumulating chamber to the main valve chamber and the passage from the main valve chamber to the atmosphere, and a main valve that extends from the main valve chamber and communicates with the trigger valve A driving valve including a main valve control passage portion defining a control passage, and a value obtained by dividing the volume of the main valve chamber by a cross-sectional area of the main valve control passage is 1.0 or less; To provide a driving machine, wherein the door.

  According to such a configuration, exhaust of compressed air from the main valve chamber is accelerated. Further, if the value obtained by dividing the volume of the main valve chamber by the cross-sectional area of the main valve control passage is reduced to 0.8 or less or 0.6 or less, exhaust can be made faster.

  According to the driving machine of the first aspect, since the time required for the main valve chamber to drop to a predetermined pressure due to the exhausting is reduced, the main valve is pressed after the plunger is pushed based on the operation of the trigger and the push lever. The time required for moving to the maximum displacement can be shortened. Therefore, it is possible to shorten the time from the operation of the trigger and the push lever to the driving operation generated due to the displacement of the main valve.

  According to the driving machine of the second and third aspects, since the cross-sectional area of the passage used for exhaust is further increased with respect to the volume of the main valve chamber, the above effect is further increased.

  According to the driving machine of the fourth aspect, since the time required for the trigger valve chamber to drop to a predetermined pressure due to the exhaust is reduced, the time required for the valve piston to move to the maximum displacement after the plunger is pushed is further increased. Can be shortened. Accordingly, it is possible to further shorten the time from the operation of the trigger and the push lever to the driving operation generated due to the displacement of the trigger valve.

  According to the driving machine of the fifth and sixth aspects, since the cross-sectional area of the trigger valve control passage used for exhaust is further increased with respect to the volume of the trigger valve chamber, the above effect is further increased.

  According to the driving machine of the seventh aspect, since the flow resistance of the main valve control passage is reduced, air is quickly released from the main valve chamber, so that the main valve moves to the maximum displacement after the plunger is pushed. Time can be shortened.

  According to the driving machine of the eighth aspect, since the flow resistance of the main valve control passage is further reduced, the air escape from the main valve chamber is further accelerated, and the main valve is moved to the maximum displacement after the plunger is pushed. The traveling time can be further shortened.

  According to the driving machine according to claim 9, in the driving machine provided with at least the main valve, the time required for the main valve chamber to drop to a predetermined pressure due to exhausting is reduced. Therefore, it is possible to shorten the time for the main valve to move to the maximum displacement after the plunger is pushed. Therefore, it is possible to shorten the time from the operation of the trigger and the push lever to the driving operation generated due to the displacement of the main valve.

  According to the driving machine of the tenth and eleventh aspects, since the cross-sectional area of the passage used for exhaust is further increased with respect to the volume of the main valve chamber, the above effect is further increased.

  According to the driving machine of the twelfth aspect, since the flow resistance of the main valve control passage is reduced, the air is quickly released from the main valve chamber, so that the above effect is further increased.

  According to the driving machine of the thirteenth aspect, since the flow resistance of the main valve control passage is further reduced, the air escape from the main valve chamber is further accelerated, and the above effect is further increased.

  According to the driving machine according to claim 14, in the driving machine provided with at least the valve piston, by increasing the cross-sectional area of the trigger valve control passage used for exhausting with respect to the volume of the trigger valve chamber, Since the time required for the trigger valve chamber to drop to a predetermined pressure is reduced, the time required for the valve piston to move to the maximum displacement after the plunger is pushed can be further shortened. Therefore, it is possible to further shorten the time from the operation of the trigger and the push lever to the driving operation generated due to the displacement of the valve piston.

  According to the driving machine of the fifteenth and sixteenth aspects, since the cross-sectional area of the trigger valve control passage used for exhaust is further increased with respect to the volume of the trigger valve chamber, the above effect is further increased.

  According to the 17th aspect of the present invention, since the time required for the main valve chamber to be lowered to the predetermined pressure due to the exhaust is reduced in the driving machine having at least the main valve, it is based on the operation of the trigger valve. This shortens the time for the main valve to move to the maximum displacement. Therefore, it is possible to shorten the time from the operation of the trigger valve to the driving operation generated due to the displacement of the main valve.

  According to the driving machine of the eighteenth and nineteenth aspects, since the cross-sectional area of the passage used for exhaust is further increased with respect to the volume of the main valve chamber, the above effect is further increased.

  A first embodiment of the driving machine will be described with reference to FIGS. A driving machine 1 shown in FIG. 1 is a driving machine using compressed air as a power source, and a frame 60, a handle 60 </ b> A located at one of the frames 60, and a nose 41 located at the lower end of the frame 60 are integrally provided. It has been. Compressed air from a compressor (not shown) is accumulated in the pressure accumulating chamber 2 formed in the handle 60A and the frame 60 of the driving machine 1 via an air hose (not shown). A cylindrical cylinder 3 is provided in the frame 60. A piston 4a is provided in the cylinder 3 so as to be slidable in the vertical direction. A driver blade 4b is integrally formed on the piston 4a. 5 is to be typed.

  A return chamber 33 for storing compressed air for returning the driver blade 4b to the top dead center is provided on the outer periphery of the lower end of the cylinder 3. A check valve 34 is provided at the center of the cylinder 3 in the axial direction, and an air passage 35 is formed to flow only in one direction from the inside of the cylinder 3 to the return air chamber 33 outside the cylinder 3. An air passage 36 that is always open to the return air chamber 33 is formed.

  A piston bumper 37 is provided at the lower end of the cylinder 3 for absorbing the surplus energy of the driver blade 4b after driving the fastener 5.

  An operating portion 38 is provided at the base of the handle 60A. The operating portion 38 protrudes from the lower end of the nose 41 and the trigger 39 that is operated by the operator, the arm plate 48 that is rotatably attached to the trigger 39, and the nose 41. The push lever 42 extends to the vicinity of the arm plate 48, is urged to the opposite side of the frame 60, and can move along the nose 41. Further, a trigger valve portion 6 described later is provided at a position facing the trigger 39 at the base portion of the handle 60A.

  As is well known, when both the pulling operation of the trigger 39 and the pressing operation of the push lever 42 against the driven material are performed, the trigger mechanism as shown in FIG. The plunger 7 of the valve unit 6 is configured to be pushed up.

  The injection unit 43 provided in association with the nose 41 is provided with a magazine 44 that fills the fastener 5 and a feeding mechanism 45 that sequentially feeds the fastener 5 loaded in the magazine 44 to the injection port 46. ing.

  The trigger valve section 6 shown in FIGS. 1 and 2 includes an outer valve bush 10 and an inner valve bush 11, a valve piston 9, a plunger 7, and a spring 12 as main components. The outer valve bush 10 and the inner valve bush 11 are fixed to the frame 60 as a trigger valve outer frame portion that is an outer shell of the trigger valve. The valve piston 9 is provided in the outer valve bush 10 and the inner valve bush 11 so as to be slidable back and forth. The plunger 7 is provided in the valve piston 9 and the through hole in the outer valve bush 10 so as to be slidable back and forth, and the lower end abuts on the arm plate 48. The spring 12 is provided between the valve piston 9 and the plunger 7 and biases the valve piston 9 upward and biases the plunger 7 downward.

The trigger valve section 6 communicates with a main valve control passage 40 which is a circular pipe extending from a main valve chamber 8 described later. Specifically, the main valve control passage 40 is connected to the outer valve bush 10 and the inner valve. It communicates with the bush 11 and opens in the trigger valve section 6. The main valve control passage 40 is formed so that its cross-sectional area S1 is 3.2 × 10 ⁻⁵ (m ² ).

  An O-ring 17 that always cuts off the communication between the pressure accumulating chamber 2 and the main valve control passage 40 is fitted to the inner valve bush 11, and the main valve control passage 40 and the atmosphere are always cut off from the valve bush 11. An O-ring 25 is fitted.

  One surface of the valve piston 9 in the sliding direction faces the pressure accumulating chamber 2, and the portions related to the inner valve bush 11 and the outer valve bush 10 of the valve piston 9 have the diameters of the inner valve bush 11 and the outer valve bush 9. An O-ring 21 and an O-ring 23 that block the respective passages are fitted into the small-shaped portions that are formed smaller than the hole diameter formed in the one-way valve piston 9.

  Therefore, an air passage 20 communicating from the main valve control passage 40 to the pressure accumulating chamber 2 is formed between the valve piston 9 and the inner valve bush 11, and the main valve control is performed between the valve piston 9 and the outer valve bush 10. An air passage 22 communicating with the atmosphere from the passage 40 is formed. The cross-sectional area of the air passage 22 with respect to the flow direction is formed larger than the cross-sectional area of the main valve passage 40. Therefore, the flow resistance of the air passage 22 is smaller than the flow resistance of the main valve passage 40. These air passage 20 and air passage 22 are alternatively communicated and blocked by the valve piston 9 sliding up and down.

A trigger valve chamber 13 is defined below the valve piston 9 by the other surface in the sliding direction of the valve piston 9 and the outer valve bush 10. The volume of the trigger valve chamber 13 fluctuates because the valve piston 9 is movably accommodated. The maximum value of the volume, that is, the value V2 when the valve piston 9 is at the top dead center is 4.0 × 10 ^{−. 7} (m ³ ). Further, an O-ring 24 that always cuts off the communication between the trigger valve chamber 13 and the air passage 22 is fitted to a portion of the valve piston 9 related to the trigger valve chamber 13.

The plunger 7 passes through the trigger valve chamber 13, and the upper end side faces the pressure accumulating chamber 2. The portion of the plunger 7 related to the valve piston 9 and the outer valve bush 10 is formed such that the diameter of the plunger 7 at that portion is smaller than the diameter of the hole formed in the valve piston 9 and the valve bush 10. An O-ring 15 and an O-ring 18 that block the respective passages are fitted in the places.
Therefore, an air passage 14 communicating from the pressure accumulation chamber 2 to the trigger valve chamber 13 is formed between the plunger 7 and the valve piston 9, and between the plunger 7 and the outer valve bush 10, the trigger valve chamber 13 communicates with the atmosphere. A communicating trigger valve control passage 16 is formed. The air passage 14 and the trigger valve control passage 16 are selectively communicated and blocked when the plunger 7 slides.

The cross sectional area S2 of the trigger valve control passage 16 formed between the outer valve bush 10 and the plunger 7 is formed to be 1.98 × 10 ⁻⁶ (m ² ). Therefore, the value obtained by dividing the volume of the trigger valve chamber 13 by the cross-sectional area of the trigger valve control passage 16 is V2 / S2 = 0.2.

  In the configuration of the trigger valve section 6, when the valve piston 9 is located on the top dead center side, the air passage 20 is opened, the pressure accumulating chamber 2 and the main valve control passage 40 are communicated, and the air passage 22 is closed. Thus, the main valve control passage 40 and the atmosphere are blocked by the O-ring 23. When the valve piston 9 is located on the bottom dead center side, the air passage 20 is closed and the main valve control passage 40 and the pressure accumulating chamber 2 are shut off by the O-ring 21, and the air passage 22 is opened and the main passage is opened. The valve control passage 40 communicates with the atmosphere.

  When the plunger 7 is located on the top dead center side, the trigger valve control passage 16 is opened and the trigger valve chamber 13 communicates with the atmosphere, and the air passage 14 is closed and the pressure accumulation chamber 2 and the trigger valve chamber 13 are closed. Are blocked by the O-ring 15. When the plunger 7 is located on the bottom dead center side, the trigger valve control passage 16 is closed, the trigger valve chamber 13 and the atmosphere are shut off by the O-ring 18, and the air passage 14 is opened to accumulate the pressure accumulation chamber. 2 and the trigger valve chamber 13 communicate with each other.

  A main valve portion 26 is provided on the upper outer periphery of the cylinder 3 shown in FIGS. The main valve portion 26 is installed above the main valve 19, the main valve rubber 27 fitted above the cylinder 3, the main valve spring 28 for urging the main valve 19 toward the bottom dead center, and above the cylinder 3. The exhaust passage 30 is configured to block an air passage 29 for exhausting compressed air in the upper chamber of the piston 4 a by contacting the main valve 19. The air passage 29 communicates with the atmosphere through an exhaust hole 49 provided in the upper portion of the frame 60.

  The main valve 19 is provided so as to be accommodated in a main valve defining portion 61 formed from a part of the frame 60, and this accommodation location becomes the main valve chamber 8 and communicates with the main valve control passage 40.

The main valve chamber 8 is fitted above and near the center of the main valve 19, and the O-ring 31 that always blocks communication between the main valve chamber 8 and the air passage 29, and communication between the main valve chamber 8 and the pressure accumulating chamber 2. Airtightness is maintained by the O-ring 32 that always shuts off. The volume V1 of the main valve chamber 8 fluctuates when the main valve 19 moves up and down, but is shaped so that the maximum value of the volume is 2.56 × 10 ⁻⁵ (m ³ ). Therefore, the value obtained by dividing the volume of the main valve chamber 8 by the cross-sectional area of the main valve control passage 40 is V1 / S1 = 0.8 ≦ 1.0. Further, the bent portion of the main valve control passage 40 is formed in a gentle arc shape between before and after the bending as shown by a portion surrounded by a circle 51 in FIG.

  When the main valve 19 is located on the top dead center side, the main valve 19 comes into contact with the exhaust rubber 30 to close the air passage 29, and the upper chamber of the piston 4a in the cylinder 3 and the atmosphere are shut off. The upper chamber of the piston 4a in the cylinder 3 and the pressure accumulating chamber 2 communicate with each other. When the main valve 19 is located on the bottom dead center side, the main valve 19 comes into contact with the main valve rubber 27 to shut off the upper chamber of the piston 4a and the pressure accumulating chamber 2 in the cylinder 3, and the main valve 19 19 separates from the exhaust bar 30 and opens the air passage 29 to connect the upper chamber of the piston 4a in the cylinder 3 and the atmosphere.

  A driving operation by the driving machine 1 having the above configuration will be described. A state in which compressed air is stored by connecting an air hose (not shown) to the driving machine 1 is shown in FIGS. The compressed air is accumulated in the pressure accumulation chamber 2. At this time, as shown in FIG. 2, since the pressure in the pressure accumulating chamber 2 acts on the upper end surface of the plunger 7, the plunger 7 is located at the bottom dead center in combination with the urging force of the spring 12. Yes. Since the plunger 7 is located at the bottom dead center, the air passage 14 is opened, and the pressure accumulating chamber 2 and the trigger valve chamber 13 communicate with each other. At the same time, since the trigger valve control passage 16 is closed by the O-ring 18, the communication between the trigger valve chamber 13 and the atmosphere is blocked, and a part of the compressed air in the pressure accumulating chamber 2 is triggered via the air passage 14. Air that flows into the valve chamber 13 and has the same pressure as the pressure accumulating chamber 2 is accumulated.

  At this time, the valve piston 9 is located at the top dead center due to the difference between the pressing force of the spring 12 and the pressure receiving area. Since the valve piston 9 is located at the top dead center, the air passage 20 is opened and the pressure accumulating chamber 2 and the main valve control passage 40 are communicated with each other. At the same time, since the air passage 22 is closed, the communication between the main valve control passage 40 and the atmosphere is blocked by the O-ring 23, and a part of the compressed air in the pressure accumulating chamber 2 flows into the main valve control passage 40. In the main valve chamber 8, air having the same pressure as that of the pressure accumulating chamber 2 is accumulated.

  Since a part of the compressed air in the pressure accumulating chamber 2 flows into the main valve chamber 8, it is generated due to the pressure receiving area difference between the lower outer peripheral surface 52 of the main valve 19 and the upper end surface 54 of the main valve 19 as shown in FIG. The main valve 19 is located at the bottom dead center by the downward pressing load and the urging force of the main valve spring 28.

  Since the main valve 19 is located at the bottom dead center, the main valve 19 comes into contact with the main valve rubber 27 and is separated from the exhaust rubber 30 so that the air passage 29 is opened. Therefore, the upper chamber of the piston 4a in the cylinder 3 communicates with the atmosphere, and the upper chamber of the piston 4a is at atmospheric pressure. Further, since the communication between the upper chamber of the piston 4a and the pressure accumulation chamber 2 in the cylinder 3 is blocked, the air from the pressure accumulation chamber 2 does not flow into the upper chamber of the piston 4a. Therefore, the piston 4a is stopped at the top dead center side.

  FIG. 4 shows a state at the moment when both the pulling operation of the trigger 39 and the pressing operation of the push lever 42 against the driven material are performed and the plunger 7 is pushed up to the top dead center. When the plunger 7 is positioned on the top dead center side, the seal of the O-ring 18 becomes invalid, and the trigger valve control passage 16 is opened. As a result, the trigger valve chamber 13 and the atmosphere communicate with each other, so that the inside of the trigger valve chamber 13 is at atmospheric pressure. Further, since the air passage 14 is closed and the communication between the pressure accumulating chamber 2 and the trigger valve chamber 13 is blocked by the O-ring 15, the inflow of air from the pressure accumulating chamber 2 into the trigger valve chamber 13 is stopped.

  Since the inside of the trigger valve chamber 13 is atmospheric pressure, a difference is generated between the pressure received by the pressure accumulating chamber 2 side of the valve piston 9 and the pressure received by the inside of the trigger valve chamber 13, and the valve piston 9 is at the bottom dead center as shown in FIG. Moving.

  Here, the first feature according to the first embodiment will be described. As described above, the value obtained by dividing the volume V2 of the trigger valve chamber 13 by the cross-sectional area S2 of the trigger valve control passage 16 is V2 / S2 = 0.2. This value is set smaller than the conventional driving machine. This is a design philosophy obtained from focusing on the principle that the mass flow rate and the pipe cross-sectional area are proportional to each other in the flow of the pipe. That is, in a driving machine having a valve chamber, it is necessary to increase the cross-sectional area of a passage used for exhaust with respect to the volume of the valve chamber, thereby reducing the valve chamber pressure to a predetermined pressure due to exhaust. It is based on finding that time decreases.

  FIG. 6 shows the relationship between the time T2 and V2 / S2 when the valve piston 9 moves to the maximum displacement after the pressure in the trigger valve chamber 13 starts to decrease. As V2 / S2 is decreased, T2 is also decreased. In the case of the value of the first embodiment: V2 / S2 = 0.2, T2 is about 0.75 ms. If V2 / S2 = 0.15, T2 can be further reduced, and if V2 / S2 = 0.10, it can be further reduced.

  Therefore, by setting the trigger valve chamber 13 volume V2 and the cross-sectional area S2 of the trigger valve control passage 16 to the above values, the compressed air in the trigger valve chamber 13 is quickly released, and the trigger valve chamber 13 becomes atmospheric pressure. Is shortened. Further, when the valve piston 9 is lowered to the bottom dead center, air escape is improved, so that it is difficult to form a so-called air damper in which the pressure in the trigger valve chamber 13 prevents the valve piston 9 from descending. You can move from the dead center to the bottom dead center. The valve piston 9 is urged toward the top dead center by the spring 12, but the spring force of the spring 12 is set to be weaker than the force generated by this pressure difference in advance, so that the operation of the valve piston 9 is affected. Never give.

  As shown in FIG. 5, when the valve piston 9 is located at the bottom dead center, the air passage 20 is closed and the communication between the main valve control passage 40 and the pressure accumulating chamber 2 is blocked by the O-ring 21, 2 stops the flow of air into the main valve control passage 40. Further, the seal of the O-ring 23 becomes invalid, the air passage 22 is opened, and the main valve control passage 40 communicates with the atmosphere. Thereby, the inside of the main valve control passage 40 becomes atmospheric pressure, and the inside of the main valve chamber 8 connected to the main valve control passage 40 also becomes atmospheric pressure.

  When the inside of the main valve chamber 8 is at substantially atmospheric pressure, the main valve 19 is moved as shown in FIG. 7 by the upward pressure generated by the pressure difference between the lower outer peripheral surface 52 of the main valve 19 and the upper end surface 54 of the main valve 19. Move to the top dead center. When the main valve 19 starts to move toward the top dead center side, the pressure accumulating chamber 2 and the upper chamber of the piston 4a in the cylinder 3 communicate with each other, so that the pressure received by the lower end surface 53 of the main valve 19 in addition to the lower outer peripheral surface 52 The main valve 19 suddenly moves to the top dead center, contacts the exhaust rubber 30 and the communication between the pressure accumulating chamber 2 and the upper chamber of the piston 4a and the atmosphere is shut off.

  Here, as described above, the value V1 / S1 = 0.8 obtained by dividing the main valve chamber 8 volume V1 by the main valve control passage 40 sectional area S1. This value is set smaller than the value of the conventional driving machine. Similarly to the above-described design concept, in a driving machine having a valve chamber, by increasing the cross-sectional area of the passage used for exhaust with respect to the volume of the valve chamber, the valve chamber pressure is predetermined by the exhaust. This is based on the design philosophy that the time required for the pressure to decrease is reduced.

  FIG. 8 shows the result of examining the relationship between the time T1 and V1 / S1 when the main valve 19 moves to the maximum displacement point after the pressure in the main valve chamber 8 starts to decrease. As V1 / S1 is decreased, T1 is also decreased. In the case of the value of the first embodiment: V1 / S1 = 0.8, T1 is about 7.0 ms. Further, even when V1 / S1 = 1.0, T1 is about 7.5 ms, which can be sufficiently reduced as compared with the conventional case. Further, by setting V1 / S1 = 0.6, T1 can be further reduced to about 5.0 ms.

  In the first embodiment, the main valve control passage 40 has a bent portion that serves as a flow path resistance. By making this a gentle arc-shaped path, an increase in flow path resistance can be suppressed, and The flow of air flowing through the valve control passage 40 is not obstructed. The air in the main valve chamber 8 is discharged from the main valve control passage 40 to the atmosphere through the air passage 22 of the trigger valve section 6, and at this time, the air passage 22 has a cross-sectional area with respect to the air flow passage. Since the air passage 22 is formed larger than the cross-sectional area of the control passage 40, the air passage 22 does not hinder the flow of air discharged from the main valve chamber 8 to the atmosphere.

  Accordingly, by setting the volume of the main valve chamber 8 and the cross-sectional area of the main valve control passage 40 to the above values, the compressed air accumulated in the main valve chamber 8 is quickly released, and the main valve chamber 8 becomes atmospheric pressure. The time until is shortened. Further, by making the shape of the main valve control passage 40 and the air passage 22 good, the air can be easily removed even when the main valve 19 rises to the top dead center, and a so-called air damper is formed in the main valve chamber 8. The main valve 19 can immediately move from the bottom dead center to the top dead center.

  When the main valve 19 moves from the bottom dead center to the top dead center, the compressed air flows into the upper chamber of the piston 4a from the pressure accumulating chamber 2, and the piston 4a rapidly moves to the bottom dead center side while moving to the piston 4a. The fastener 5 is driven in by the connected tip part 4c. The air below the piston 4 a in the cylinder 3 flows into the return air chamber 33 through the air passage 36, and when the piston 4 a passes through the air passage 35, a part of the compressed air in the upper chamber of the piston 4 a becomes the air passage 35. And then flows back into the return air chamber 33.

  FIG. 9 shows a state at the moment when the trigger 39 is returned or the pushing operation of the push lever 42 against the workpiece is stopped and the plunger 7 is returned to the bottom dead center. The plunger 7 moves to the bottom dead center side by the pressure of the pressure accumulating chamber 2 acting on the upper end portion and the pressing force of the spring 12.

  When the plunger 7 moves to the bottom dead center, the trigger valve control passage 16 is blocked by the O-ring 18, the seal of the O-ring 15 becomes invalid, and the compressed air in the pressure accumulating chamber 2 is triggered via the air passage 14. It flows into the chamber 13.

  When compressed air flows into the trigger valve chamber 13, the valve piston 9 is moved to the top dead center side by the pressing force generated by the difference between the area of the upper end face and the area of the lower end face of the valve piston 9 and the biasing force of the spring 12. Moving.

  The air passage 22 is blocked from the atmosphere by the O-ring 23, the pressure accumulating chamber 2 and the main valve chamber 8 communicate with each other through the air passage 20, and the compressed air flows into the main valve chamber 8. When compressed air flows into the main valve chamber 8, a downward pressing force is generated due to a pressure receiving area difference between the lower outer peripheral surface 52 of the main valve 19, the lower end surface 53 of the main valve 19, and the upper end surface 54 of the main valve 19. To do. The main valve 19 moves to the bottom dead center side by the pressing force and the urging force of the main valve spring 28.

  When the main valve 19 moves to the bottom dead center and comes into contact with the main valve rubber 27, the communication between the pressure accumulating chamber 2 and the upper chamber of the piston 4a is cut off, and when separated from the exhaust rubber 30, the upper chamber of the piston 4a and the atmosphere Communicate. The lower side of the piston 4a is pressed by the compressed air accumulated in the return air chamber 33, and the piston 4a suddenly moves to the top dead center side. The air in the upper chamber of the piston 4a is released to the atmosphere from the exhaust hole 49 through the air passage 29, and the driving machine 1 returns to the initial state shown in FIG.

The above operation will be described in time series. The graph shown in FIG. 10 shows the characteristics of the driving machine 1 according to the first embodiment, and the graph shown in FIG. 11 shows the characteristics of a conventional driving machine as a comparative example. In these graphs, the time is the x-axis, and the pressure change, the main valve displacement, the valve piston displacement, and the piston displacement are each y-axis. Here, the origin (0 ms) of the x-axis is when the pressure in the trigger valve chamber 13 starts to decrease as the plunger 7 is pushed up. The dimensions of the driving machine according to the conventional example are the maximum value V1 ′ = 2.56 × 10 ⁻⁵ (m ³ ) of the main valve chamber volume, and the cross-sectional area S1 ′ = 0.8 × 10 ^{− of the} main valve control passage. ⁵ (m ² ), V1 ′ / S1 ′ = 3.2, the maximum value of the trigger valve chamber volume V2 ′ = 4.0 × 10 ⁻⁷ (m ³ ), and the cross-sectional area S2 ′ = trigger valve control passage 0.465 × 10 ⁻⁶ (m ² ), and V2 ′ / S2 ′ = 0.86. The dimensions of the driving machine according to the first embodiment are the values described above, the maximum value V1 of the main valve chamber 8 volume V1 = 2.56 × 10 ⁻⁵ (m ³ ), and the cross-sectional area S1 of the main valve control passage 40. = 3.2 × 10 ⁻⁵ (m ² ), V1 / S1 = 0.8, maximum value of the trigger valve chamber 13 volume V2 = 4.0 × 10 ⁻⁷ (m ³ ), trigger valve control passage 16 The cross-sectional area S2 = 1.98 × 10 ⁻⁶ (m ² ) and V2 / S2 = 0.2.

  By pushing the plunger 7, the pressure in the trigger valve chamber 13 decreases, and the valve piston 9 starts to be displaced from the top dead center position in conjunction with this pressure change. At this time, the value obtained by dividing the volume of the trigger valve chamber 13 by the cross-sectional area of the trigger valve control passage 16 is the value of the first embodiment: V2 / S2 with respect to the value of the conventional example: V2 ′ / S2 ′ = 0.86. Therefore, the compressed air in the trigger valve chamber 13 is instantaneously discharged into the atmosphere from the trigger valve control passage 16. As a result, it took 11.3 ms for the trigger valve chamber pressure to drop to atmospheric pressure (0 Pa), whereas in the first embodiment, it is possible to reduce the pressure to atmospheric pressure after 3.0 ms. . Further, it took 0.85 ms for the conventional valve piston 9 to reach the bottom dead center position, but in the first embodiment, it reached the bottom dead center position after 0.74 ms.

  When the valve piston 9 starts to be displaced, the seal by the O-ring 23 becomes invalid, the air passage 22 communicates with the main valve control passage 40, and the pressure in the main valve chamber 8 starts to drop. At this time, the value obtained by dividing the main valve chamber 8 volume V1 by the cross-sectional area S1 of the main valve control passage 40 is the value of the first embodiment: V1 with respect to the value of the conventional example: V1 ′ / S1 ′ = 3.2. /S1=0.8, the compressed air in the main valve chamber 8 is instantaneously discharged from the main valve control passage 40 and the air passage 22. As a result, it took 22.4 ms for the main valve chamber pressure to drop to the extreme value and the main valve starts to be displaced from the bottom dead center. On the other hand, in the first embodiment, the main valve pressure is 6.1 ms later. The pressure in the chamber 8 decreases to the extreme value, and the main valve 19 starts to be displaced from the bottom dead center. At this time, the pressure of the main valve chamber 8 temporarily rises due to the displacement of the main valve 19, but since the cross-sectional area of the air passage 22 is smaller than the cross-sectional area of the main valve control passage 40, There is no excessive back pressure. The main valve 19 according to the first embodiment moves to the top dead center after 7.1 ms.

  When the main valve 19 moves to the top dead center, compressed air flows into the upper chamber of the piston 4a from the pressure accumulating chamber 2, and the upper chamber of the piston 4a becomes high pressure. Due to the pressure difference between the upper chamber and the lower chamber of the piston 4a, The piston 4a descends, reaches the bottom dead center, and drives the fastener 5. As a result, the process from when the operator pulls the trigger 39 to when the fastener 5 is driven is completed, whereas in the conventional example, it took 27.1 ms, whereas in the first embodiment, after 11.3 ms. The process until the fastener 5 is driven is finished, and the response of driving is clearly improved.

  After the driving, the plunger 7 is returned to the original position, the trigger valve control passage 16 is closed, the compressed air flows into the trigger valve chamber 13 from the pressure accumulating chamber 2, the valve piston 9 moves to the top dead center, and the valve piston 9 Is moved to the top dead center, the air passage 22 is closed and the seal of the air passage 20 is invalidated, and the compressed air flows into the main valve chamber 8 from the pressure accumulating chamber 2 to cause the main valve 19 to move to the bottom dead center. Move to. When the main valve 19 moves to the bottom dead center, the communication between the pressure accumulating chamber 2 and the upper chamber of the piston 4a is cut off, and the upper chamber of the piston 4a and the atmosphere communicate with each other, so that the pressure in the upper chamber of the piston 4a decreases. Due to the pressure of the compressed air stored in the return chamber 33, the piston 4a rises and returns to the initial state (the state of 0 ms in FIG. 10).

  In addition, as a result of conducting experiments using various driving machines and investigating how much the response is improved, a sufficient effect is recognized, after the pulling operation of the trigger and the pushing operation of the push lever to the driven material, It has been confirmed that when the driving is finished within 12 ms, the response is very good, it is easy to work, and it is easy to hit the fastener continuously. And as the time becomes longer, the response gradually becomes worse, it is difficult to work around 27.1ms of the conventional example, and it has been confirmed that it is difficult to hit many fasteners continuously. Accordingly, the driving machine 1 according to the first embodiment improves the response and improves the work performance.

  In the first embodiment, as shown in FIG. 3, the bent portion surrounded by the circle 51 of the main valve control passage 40 is formed into a gentle arc shape before and after the bending. In addition to this, as shown in FIG. 12, for example, it may be formed by at least two refracting portions. At this time, the angle of the refracting part is preferably 100 ° or more. As a result, the air in the main valve chamber 8 can be discharged without forming excessive flow resistance in the main valve control passage 40.

  Next, a driving machine according to a second embodiment will be described with reference to FIGS. The schematic configuration of the driving machine 101 shown in FIG. 13 is a configuration obtained by removing the valve piston 9 from the driving machine 1 according to the first embodiment. Therefore, detailed description is omitted. The driving machine 101 is a driving machine using compressed air as a power source, and a frame 160, a handle 160 </ b> A located at one of the frames 160, and a nose 141 located at the lower end of the frame 160 are integrally provided, and compressed air Is accumulated in the pressure accumulating chamber 102 formed in the handle 160A and the frame 160 of the driving machine 101 via an air hose (not shown). A cylindrical cylinder 103 is provided in the frame 160. A piston 104a is provided in the cylinder 103 so as to be slidable in the vertical direction. A driver blade 104b is integrally formed on the piston 104a. Is to be typed in.

  A return chamber 133 for storing compressed air for returning the driver blade 104b to the top dead center is provided on the outer periphery of the lower end of the cylinder 103. A check valve 134 is provided at the center of the cylinder 103 in the axial direction, and an air passage 135 is formed to flow only in one direction from the inside of the cylinder 103 to the return air chamber 133 outside the cylinder 103. An air passage 136 that is always open to the return air chamber 133 is formed.

  Further, a piston bumper 137 for absorbing surplus energy of the driver blade 104b after driving the fastener is provided at the lower end of the cylinder 103.

  A trigger 139 operated by an operator is provided at the base portion of the handle 160A, and a trigger valve portion 106 described later is provided at a location facing the trigger 139 at the base portion of the handle 160A.

  As is well known, the plunger 107 of the trigger valve section 106 is pushed up when both the pulling operation of the trigger 139 and the pressing operation of the push lever 142 against the driven material are performed.

  The trigger valve unit 106 shown in FIGS. 13 and 14 includes a valve bush 110, a plunger 107, and a spring 112 as main components. The valve bush 110 is fixed to the frame 160 as a trigger valve outer frame portion that is an outline of the trigger valve. The plunger 107 is provided in a through hole in the valve bush 110 so as to be slidable back and forth, and a lower end abuts on the trigger 139. The spring 112 is provided between the frame 160 and the plunger 107 and biases the plunger 107 downward.

The trigger valve unit 106 extends from a main valve chamber 108 described later, and communicates with a main valve control passage 140 formed of a circular pipe. The main valve control passage 140 is shaped so that its cross-sectional area S1 is 3.2 × 10 ⁻⁵ (m ² ).

  The valve bush 110 is fitted with an O-ring 125 that always shuts off the main valve control passage 140 and the atmosphere. A trigger valve chamber 113 is defined in the space inside the frame 160 and the valve bush 110 fixed to the frame 160.

The plunger 107 passes through the trigger valve chamber 113, and the upper end side can pass through the air passage 120 which is a hole formed in the frame 160. An O-ring 115 that closes the air passage 120 by fitting with the plunger 107 is fitted to the frame 160 in the air passage 120. A location related to the valve bush 110 of the plunger 107 is formed such that the diameter of the plunger 107 at that location is smaller than the diameter of the hole formed in the valve bush 10, and the air passage 116 is formed by this gap. The air passage 116 is formed so that the cross-sectional area with respect to the direction in which the plunger 107 slides is at least 3.2 × 10 ⁻⁵ (m ² ) or more. An O-ring 118 that closes the air passage 116 is fitted to the valve bush 110 in the air passage 116. These air passage 120 and air passage 116 are alternatively communicated and blocked by sliding of the plunger 107.

  A main valve portion 126 is provided on the upper outer periphery of the cylinder 103 shown in FIG. The main valve portion 126 includes a main valve 119, a main valve spring 128 that urges the main valve 119 toward the bottom dead center, and the like. An air passage 129 is formed above the main valve 119 and communicates with the atmosphere through an exhaust hole 149 provided in the upper portion of the frame 160.

  The main valve 119 is provided so as to be accommodated in a main valve defining portion 161 formed from a part of the frame 160, and this accommodation location becomes the main valve chamber 108 and communicates with the main valve control passage 140.

The main valve chamber 108 is kept airtight by an O-ring (not shown) or the like. The main valve chamber 108 is shaped so that the maximum value of the volume is 2.56 × 10 ⁻⁵ (m ³ ), although the volume V1 varies as the main valve 119 moves up and down. Therefore, the value obtained by dividing the volume of the main valve chamber 108 by the cross-sectional area of the main valve control passage 140 is V1 / S1 = 0.8 ≦ 1.0. Further, the bent portion of the main valve control passage 140 is formed into a gentle arc shape before and after the bending.

  A driving operation by the driving machine 101 having the above configuration will be described. A state where compressed air is stored in the pressure accumulating chamber 102 by connecting an air hose (not shown) to the driving machine 101 is shown in FIGS. At this time, as shown in FIG. 14, the plunger 107 is positioned at the bottom dead center by the biasing force of the spring 112. Since the plunger 107 is located at the bottom dead center, the air passage 120 is opened, and the pressure accumulation chamber 102 and the trigger valve chamber 113 communicate with each other. At the same time, since the air passage 116 is closed by the O-ring 118, the communication between the trigger valve chamber 113 and the atmosphere is blocked.

  Further, as shown in FIG. 14, the trigger valve chamber 113 communicates with the main valve control passage 140, so that a part of the compressed air in the pressure accumulating chamber 102 flows into the main valve control passage 140 and enters the main valve chamber 108. Air having the same pressure as the pressure accumulating chamber 102 is accumulated.

  Since the compressed air in the pressure accumulating chamber 102 flows into the main valve chamber 108, as shown in FIG. 13, the downward direction occurs due to the pressure receiving area difference between the lower outer peripheral surface 147 of the main valve 119 and the upper end surface 143 of the main valve 119. The main valve 119 is located at the bottom dead center by the pushing load on the main valve spring and the biasing force of the main valve spring 128.

  Since the main valve 119 is located at the bottom dead center, the main valve 119 comes into contact with the upper end surface of the cylinder 103 and is separated from the frame 160 to open the air passage 129. Therefore, the upper chamber of the piston 104a in the cylinder 103 is opened. And the atmosphere communicate with each other, and the upper chamber of the piston 104a is at atmospheric pressure. Further, since communication between the upper chamber of the piston 104a and the pressure accumulation chamber 102 in the cylinder 103 is blocked, air from the pressure accumulation chamber 102 does not flow into the upper chamber of the piston 104a. Therefore, the piston 104a is stopped at the top dead center side.

  FIGS. 15 and 16 show the state at the moment when both the pulling operation of the trigger 139 and the pressing operation of the push lever 142 against the workpiece are performed and the plunger 107 is pushed up to the top dead center. Since the upper end side of the plunger 107 penetrates into the O-ring 115 in the air passage 120, the trigger valve chamber is blocked from the pressure accumulation chamber 102. Further, when the plunger 107 is positioned on the top dead center side, the seal of the O-ring 118 becomes invalid and the air passage 116 is opened. As a result, the trigger valve chamber 113 communicates with the atmosphere. The cross-sectional area of the air passage 116 with respect to the flow direction is formed larger than the cross-sectional area of the main valve passage 140. Therefore, the flow resistance in the air passage 116 is smaller than the flow resistance in the main valve passage 140. The main valve control passage 140 communicating with the trigger valve chamber 113 is also communicated with the atmosphere, and the inside of the main valve chamber 108 communicating with the main valve control passage 140 is also communicated with the atmosphere and becomes atmospheric pressure.

  When the inside of the main valve chamber 108 becomes substantially atmospheric pressure, as shown in FIG. 16, the main valve chamber 108 has an upward pressure generated by a pressure receiving area difference between the lower outer peripheral surface 147 of the main valve 119 and the upper end surface 143 of the main valve 119. 119 moves to the top dead center side. When the main valve 119 starts to move toward the top dead center side, the pressure accumulating chamber 102 and the upper chamber of the piston 104a in the cylinder 103 communicate with each other, so that the pressure received on the lower end surface 148 of the main valve 119 in addition to the lower outer peripheral surface 147 The main valve 119 suddenly moves to the top dead center side, the upper end of the main valve 119 comes into contact with the frame 160, the exhaust hole 149 is closed, and the communication between the pressure storage chamber 102 and the upper chamber of the piston 104a and the atmosphere is interrupted. Is done.

  Here, features according to the second embodiment will be described. As described above, the value V1 / S1 = 0.8 obtained by dividing the volume V1 of the main valve chamber 108 by the cross-sectional area S1 of the main valve control passage 140. Similarly to the design concept described in the first embodiment, in the driving machine having the valve chamber, the cross-sectional area of the passage used for the exhaust is increased with respect to the volume of the valve chamber, so that the exhaust Therefore, the time required for the valve chamber pressure to drop to a predetermined pressure is reduced.

  The time required for the main valve 119 to move to the maximum displacement point after the pressure in the main valve chamber 108 begins to drop: The relationship between T1 and V1 / S1 is approximately as shown in FIG. In the case of the value of the second embodiment: V1 / S1 = 0.8, T1 is about 7.0 ms. Further, even when V1 / S1 = 1.0, T1 is about 7.5 ms, which can be sufficiently reduced as compared with the conventional case. Further, by setting V1 / S1 = 0.6, T1 can be further reduced to about 5.0 ms. These T1 values are sufficiently smaller than those of the conventional driving machine.

  The air in the main valve chamber 108 is discharged from the main valve control passage 140 to the atmosphere through the air passage 120 of the trigger valve portion 106. At this time, the air passage 120 has a cross-sectional area with respect to the air flow passage. Since it is formed to be larger than the cross-sectional area of the control passage 140, movement to the top dead center of the main valve 119 is not hindered.

  Therefore, by setting the volume of the main valve chamber 108 and the cross-sectional area of the main valve control passage 140 to the above values, the compressed air accumulated in the main valve chamber 108 is quickly released, and the main valve chamber 108 Time to become is shortened. Further, by making the shape of the main valve control passage 140 and the air passage 120 good, the air can be easily removed even when the main valve 119 rises to the top dead center, and a so-called air damper is formed in the main valve chamber 108. Therefore, the main valve 119 can immediately move from the bottom dead center to the top dead center.

  When the main valve 119 moves from the bottom dead center to the top dead center, compressed air flows from the pressure accumulating chamber 102 into the upper chamber of the piston 104a, and the piston 104a is connected to the piston 104a while rapidly moving to the bottom dead center side. The fastener is driven in by the tip 104c. The air below the piston 104 a in the cylinder 103 flows into the return air chamber 133 via the air passage 136, and when the piston 104 a passes through the air passage 135, a part of the compressed air in the upper chamber of the piston 4 a becomes the air passage 135. And then flows back into the return air chamber 133.

  When the trigger 139 is returned or the pushing operation of the push lever 142 to the workpiece is stopped, the plunger 107 moves to the bottom dead center by the pressure of the pressure accumulating chamber 102 applied to the upper end of the plunger 107 and the biasing force of the spring 112. .

  When the plunger 107 moves to the bottom dead center, the air passage 116 is closed via the O-ring 118, the seal of the O-ring 115 is invalidated, and the compressed air in the pressure accumulating chamber 102 is triggered via the air passage 120. It flows into the chamber 113.

  When compressed air flows into the trigger valve chamber 113, the pressure accumulation chamber 102 and the main valve chamber 108 communicate with each other via the main valve control passage 140, and the compressed air flows into the main valve chamber 108.

  When compressed air flows into the main valve chamber 108, a downward pressing force generated by a pressure receiving area difference between the lower outer peripheral surface 147 of the main valve 119, the lower end surface 148 of the main valve 119, and the upper end surface 143 of the main valve 119 is generated. appear. The main valve 119 moves to the bottom dead center side by the pressing force and the urging force of the main valve spspring 128.

  When the main valve 119 moves to the bottom dead center and contacts the upper end surface of the cylinder 103, the communication between the pressure accumulating chamber 102 and the upper chamber of the piston 104a is cut off, and the upper end of the main valve 119 and the frame 160 are separated from each other. The upper chamber of the piston 104a communicates with the atmosphere. The lower side of the piston 104a is pressed by the compressed air accumulated in the return air chamber 133, and the piston 104a suddenly moves to the top dead center side. The air in the upper chamber of the piston 104a is discharged to the atmosphere from the exhaust hole 149 through the air passage 129, and the driving machine 101 returns to the initial state shown in FIG.

  Also in the second embodiment, as in the first embodiment, the bent portion of the main valve control passage 140 is formed in a gentle arc shape between before and after the bend. It may be shaped from more than one refraction part. At this time, the angle of the refracting part is preferably 100 ° or more. As a result, air in the main valve chamber 108 can be discharged without forming excessive flow resistance in the main valve control passage 140.

  Next, a third embodiment will be described with reference to FIGS. The schematic configuration of the driving machine 201 illustrated in FIG. 17 is a configuration in which the main valve unit 26 is omitted from the driving machine 1 according to the first embodiment, and detailed description thereof is omitted. The driving machine 201 is a driving machine using compressed air as a power source, and a handle 260A positioned at one of the frame 260 and the nose 241 positioned at the lower end of the frame 260 is provided integrally with the compressed air. Is accumulated in the pressure accumulating chamber 202 defined in the handle 260A and the frame 260 of the driving machine 201 via an air hose (not shown). A cylindrical cylinder 203 is provided in the frame 260. A piston 204a is provided in the cylinder 203 so as to be slidable up and down. A driver blade 204b is integrally provided in the piston 204a. Configured to be typed in.

  A return chamber 233 for storing compressed air for returning the driver blade 204b to the top dead center is provided on the outer periphery of the lower end of the cylinder 203. A check valve 234 is provided at the center of the cylinder 203 in the axial direction, and an air passage 235 is formed to flow in only one direction from the inside of the cylinder 203 to the return air chamber 233 outside the cylinder 203. An air passage 236 that is always open to the return air chamber 233 is formed. Above the cylinder 203, a piston upper chamber 266 is defined that is an area where the piston 204 a upper chamber defined by the inner surface of the cylinder 203 and the piston 204 a extends into the frame 260. This piston upper chamber 266 is defined. An air passage 262 connected to a trigger valve portion 206 to be described later is extended.

  Further, a piston bumper 237 for absorbing surplus energy of the driver blade 204b after driving a fastener (not shown) is provided at the lower end of the cylinder 203. A trigger 239 operated by an operator is provided at the base portion of the handle 260A, and a trigger valve portion 206 described later is provided at a location facing the trigger 239 at the base portion of the handle 260A. As is well known, the plunger 207 of the trigger valve portion 206 is pushed up when both the pulling operation of the trigger 239 and the pressing operation of the push lever (not shown) against the driven material are performed. The nose 241 is provided with a magazine 244 that is filled with fasteners, and a feeding mechanism (not shown) that sequentially feeds the fasteners loaded in the magazine 244 in response to the reciprocation of the piston 204a to the injection port 246. Yes.

  The trigger valve unit 206 shown in FIGS. 17 and 18 includes a valve bush 210, a valve piston 209, a plunger 207, and a spring 212 as main components.

  The valve bush 210 is fixed to the frame 260 as a trigger valve outer frame portion that is an outline of the trigger valve. The valve piston 209 is provided in the valve bush 210 so as to be able to reciprocate. The plunger 207 is provided in the through hole in the valve bush 210 so as to be slidable back and forth, and the lower end abuts on the trigger 239. The spring 212 is provided between the valve piston 209 and the plunger 207 to bias the valve piston 209 upward and bias the plunger 207 downward.

  An air passage 262, which is a circular pipe extending from the piston upper chamber 266 and defined in the frame 260, communicates with the trigger valve portion 206 and is opened in the trigger valve portion 206. An exhaust pipe 263 defined in the handle 260A and provided with an exhaust hole 249 at the end of the handle 260A is below the trigger valve portion 206 where the air passage 262 communicates with the trigger valve portion 206. The trigger valve portion 206 is open in communication. Then, the valve piston 209 penetrates inside the trigger valve section 206 between a position where the air passage 262 is opened in the trigger valve section 206 and a position where the exhaust pipe 263 is opened in the trigger valve section 206. A valve plate 264 having a hole to be drilled is provided. In addition, a gap formed in a portion of the hole provided in the valve plate 264 where the valve piston 209 penetrates becomes an air passage 222.

  An air passage 220 that communicates the inside of the trigger valve portion 206 and the pressure accumulating chamber 202 is formed at a location where the trigger valve portion 206 of the frame 260 is provided.

  One surface of the valve piston 209 in the sliding direction faces the pressure accumulating chamber 202 through the air passage 220. A valve piston rubber 221 is fitted at the upper end of the valve piston 209 near the opening of the air passage 262. The valve piston rubber 221 is a frame around the air passage 220 when the valve piston 209 is at the top dead center. When the valve piston 209 is at the bottom dead center, it contacts the periphery of the center hole of the valve plate 264.

  An outer diameter of a portion related to the valve bush 210 of the valve piston 209 is formed to be smaller than a hole diameter formed in the valve bush 210, and an O-ring 224 that blocks each passage is fitted into the small formed portion. ing. The valve bush 210 is fitted with an O-ring (not shown) that always blocks the air passage 222 and the atmosphere.

A trigger valve chamber 213 is defined below the valve piston 209 by the other surface in the sliding direction of the valve piston 209 and the valve bush 210. The volume of the trigger valve chamber 213 fluctuates because the valve piston 209 is movably accommodated. The maximum value of the volume, that is, the value V2 when the valve piston 209 is at the top dead center is 4.0 × 10 ^{−. 7} (m ³ ). Further, an O-ring 224 that always blocks communication between the trigger valve chamber 213 and the air passage 222 is fitted to a location related to the trigger valve chamber 213 of the valve piston 209.

  The plunger 207 passes through the trigger valve chamber 213, and the upper end side faces the pressure accumulating chamber 202 through a hole 261 drilled in the central portion of the valve piston 209. The portion of the plunger 207 relating to the valve piston 209 and the valve bushing 210 is formed such that the diameter of the plunger 207 at that portion is smaller than the hole diameter formed in the valve piston 209 and the valve bushing 210, and An O-ring 215 and an O-ring 218 that block the respective passages are fitted.

  Therefore, an air passage 214 communicating from the pressure accumulation chamber 202 to the trigger valve chamber 213 is formed between the plunger 207 and the valve piston 209, and the trigger valve chamber 213 communicates from the trigger valve chamber 213 to the atmosphere between the plunger 207 and the valve bush 210. A trigger valve control passage 216 is formed. The air passage 214 and the trigger valve control passage 216 are selectively communicated and blocked by the sliding of the plunger 207.

The cross-sectional area S2 of the trigger valve control passage 216 formed between the valve bush 210 and the plunger 207 is formed to be 1.98 × 10 ⁻⁶ (m ² ). Therefore, the value obtained by dividing the volume of the trigger valve chamber 213 by the cross-sectional area of the trigger valve control passage 216 is V2 / S2 = 0.2.

  In the configuration of the trigger valve portion 206, the valve piston rubber 221 contacts the frame 260 around the air passage 220 when the valve piston 209 is at the top dead center. At this time, the air passage 220 is closed and the air passage 262 and the pressure accumulating chamber 202 connected to the piston upper chamber 266 are shut off, and the air passage 222 is opened and the air passage 262 connected to the piston upper chamber 266 and the exhaust pipe 263 are connected. Is done. When the valve piston 209 is positioned on the bottom dead center side, the valve piston rubber 221 contacts the valve plate 264. At this time, the air passage 222 is closed, the air passage 262 connected to the piston upper chamber 266 and the exhaust pipe 263 are blocked, the air passage 220 is opened, and the air passage 262 connected to the piston upper chamber 266 and the pressure accumulating chamber 202 are communicated. Is done.

  When the plunger 207 is positioned on the top dead center side, the trigger valve control passage 216 is opened to connect the trigger valve chamber 213 to the atmosphere, and the air passage 214 is closed to close the pressure accumulation chamber 202 and the trigger valve 213. Is blocked by the O-ring 215. When the plunger 207 is located on the bottom dead center side, the trigger valve control passage 216 is closed and the trigger valve chamber 213 and the atmosphere are shut off by the O-ring 218, and the air passage 214 is opened and the pressure accumulation chamber is opened. 202 and the trigger valve chamber 213 communicate with each other.

  A driving operation by the driving machine 201 having the above configuration will be described. A state in which compressed air is stored in the pressure accumulating chamber 202 by connecting an air hose (not shown) to the driving machine 201 is shown in FIGS. At this time, as shown in FIG. 18, the plunger 207 is located at the bottom dead center by the biasing force of the spring 212. Since the plunger 207 is located at the bottom dead center, the air passage 214 is opened, and the pressure accumulation chamber 202 and the trigger valve chamber 213 are communicated with each other. At the same time, since the trigger valve control passage 216 is closed by the O-ring 218 in cooperation with the plunger 207, the communication between the trigger valve chamber 213 and the atmosphere is blocked, and a part of the compressed air in the pressure accumulating chamber 202 is The air flows into the trigger valve chamber 213 through the air passage 214, and air having the same pressure as that of the pressure accumulation chamber 202 is accumulated in the trigger valve chamber 213.

  At this time, the valve piston 209 is located at the top dead center due to the difference between the pressing force of the spring 212 and the pressure receiving area. Since the valve piston 209 is located at the top dead center, the air passage 220 is closed by the valve piston rubber 221 and the pressure accumulation chamber 202 and the air passage 262 are blocked. At the same time, since the air passage 222 is opened, the air passage 262 and the exhaust pipe 263 communicate with each other, the piston upper chamber 266 becomes atmospheric pressure, and the piston 204a is located at the top dead center as shown in FIG.

  FIG. 19 shows a state at the moment when both the pulling operation of the trigger 239 and the pressing operation of the push lever (not shown) against the driven material are performed and the plunger 207 is pushed up to the top dead center. When the plunger 207 is positioned on the top dead center side, the seal of the O-ring 218 becomes invalid and the trigger valve control passage 216 is opened. As a result, the trigger valve chamber 213 communicates with the atmosphere, so that the inside of the trigger valve chamber 213 is at atmospheric pressure. Further, since the communication between the pressure accumulation chamber 202 and the trigger valve chamber 213 is blocked by the O-ring 215, the air passage 214 is closed, and the inflow of air from the pressure accumulation chamber 202 into the trigger valve chamber 213 is stopped.

  Since the pressure inside the trigger valve chamber 213 becomes atmospheric pressure, a difference occurs between the pressure received on the pressure accumulating chamber 202 side of the valve piston 209 and the pressure received on the inside of the trigger valve chamber 213, and the valve piston 209 moves to the bottom dead center.

  The time required for the valve piston 209 to move to the maximum displacement point after the pressure in the trigger valve chamber 213 begins to drop: The relationship between T2 and V2 / S2 is approximately as shown in FIG. In the case of the value of the third embodiment: V2 / S2 = 0.2, the time required for the valve piston to move from the top dead center to the bottom dead center is about 0.75 ms. If V2 / S2 = 0.15, T2 can be further reduced, and if V2 / S2 = 0.10, it can be further reduced. These T2 values are sufficiently smaller than those of the conventional driving machine.

  Therefore, by setting the trigger valve chamber 213 volume V2 and the cross-sectional area S2 of the trigger valve control passage 216 to the above values, the compressed air in the trigger valve chamber 213 is quickly released, and the trigger valve chamber 213 reaches atmospheric pressure. The time required for this operation is shortened and the air escape is improved even when the valve piston 209 is lowered to the bottom dead center. Therefore, it is difficult to form a so-called air damper in the trigger valve chamber 213, and the valve piston 209 is immediately lowered from the top dead center. You can move to the dead center. The valve piston 209 is urged toward the top dead center side by the spring 212, but the spring force of the spring 212 is set to be weaker than the force generated by this pressure difference in advance, so that the operation of the valve piston 209 is affected. Never give.

  As shown in FIG. 19, when the valve piston 209 is positioned at the bottom dead center, the air passage 222 is closed by the valve piston rubber 221 and the communication between the air passage 262 and the exhaust pipe 263 is blocked. At this time, since the seal of the air passage 220 becomes invalid, the pressure accumulation chamber 202 and the air passage 262 communicate with each other so that air flows from the pressure accumulation chamber 202 into the piston upper chamber 266, and the piston upper chamber 266 has the same pressure as the pressure accumulation chamber 202. become. At this time, the pressure in the upper chamber of the piston 204a >> the pressure in the lower chamber of the piston 204a. Therefore, the piston 204a is moved suddenly toward the bottom dead center side, and the fastener is driven by the tip 204c connected to the piston 204a. The air below the piston 204 a in the cylinder 203 flows into the return air chamber 233 through the air passage 236, and when the piston 204 a passes through the air passage 235, a part of the compressed air in the upper chamber of the piston 204 a is air passage 235. And flows back into the return air chamber 233.

  When the trigger 239 is returned or the pushing operation of the push lever (not shown) against the driven material is stopped, the plunger 207 moves to the bottom dead center side by the pressure of the pressure accumulation chamber 202 acting on the upper end portion and the pressing force of the spring 212. .

  When the plunger 207 moves to the bottom dead center, the trigger valve control passage 216 is closed by the cooperation of the plunger 207 and the O-ring 218, the plunger 207 and the O-ring 215 are separated, and the seal of the O-ring 215 becomes invalid. Thus, the compressed air in the pressure accumulating chamber 202 flows into the trigger valve chamber 213 through the air passage 214.

  When compressed air flows into the trigger valve chamber 213, the valve piston 209 is moved to the top dead center side by the pressing force generated by the difference between the area of the upper end face and the area of the lower end face of the valve piston 209 and the biasing force of the spring 212. Moving.

  At this time, the air passage 220 is closed by the valve piston rubber 221 so as to block between the pressure accumulating chamber 202 and the air passage 262, so that the inflow of air from the pressure accumulating chamber 202 to the piston upper chamber 266 is stopped. Further, since the seal of the air passage 222 becomes invalid, the air passage 262 and the exhaust pipe 263 communicate with each other. Thereby, the air accumulated in the piston upper chamber 266 connected to the air passage 262 is discharged to the atmosphere from the exhaust pipe 263 and the exhaust hole 249, and the piston upper chamber 266 becomes atmospheric pressure.

  Therefore, the lower side of the piston 204a is pressed by the compressed air accumulated in the return air chamber 233, the piston 204a is suddenly moved to the top dead center side, and the driving machine 201 returns to the initial state shown in FIG.

FIG. 4 is a detailed cross-sectional view of the driving machine according to the first embodiment. The cross-sectional detail figure of the trigger valve part periphery in the driving machine concerning 1st Embodiment. The cross-sectional detail figure of the main valve part periphery in the driving machine concerning 1st Embodiment. Sectional detail drawing of the state by which the plunger 7 periphery of the trigger valve part in the driving device concerning 1st Embodiment was pushed up. Sectional detail drawing of the state which the valve piston 9 moved to the bottom dead center after the plunger 7 of the trigger valve part periphery in the driving device concerning 1st Embodiment was pushed up. The graph showing the relationship between the trigger valve chamber / trigger valve control channel | path and the time which a valve piston displaces in the driving device concerning 1st Embodiment. Sectional detail drawing of the state which the main valve 19 of the main valve part periphery in the driving machine concerning 1st Embodiment moved to the top dead center. The graph showing the relationship between the main valve chamber / main valve control channel | path in the driving device concerning 1st Embodiment, and the time which a main valve displaces. Sectional detail drawing of the state which the plunger 7 returned to the original position after the valve piston 9 of the trigger valve part periphery in the driving device concerning 1st Embodiment moved to the bottom dead center. The graph showing the relationship between each chamber pressure, main valve displacement, valve piston displacement, piston displacement, and time formed in the driving machine according to the first embodiment. The graph showing the relationship between each chamber pressure, main valve displacement, valve piston displacement, piston displacement and time formed in a conventional driving machine. Sectional detail drawing which concerns on other embodiment of the main valve part periphery in the driving machine concerning 1st Embodiment. Sectional detail drawing in the driving machine concerning 2nd Embodiment. Sectional detail drawing of the trigger valve part periphery in the driving machine concerning 2nd Embodiment. Sectional detail drawing of the state in which the plunger 107 of the trigger valve part periphery in the driving device concerning 2nd Embodiment was pushed up. Sectional detail drawing of the state which the main valve 119 in the driving machine concerning 2nd Embodiment moved to the top dead center. Sectional detail in the driving machine concerning 3rd Embodiment. Sectional detail drawing of the trigger valve part periphery in the driving machine concerning 3rd Embodiment. Sectional detail drawing of the state where the plunger 207 of the trigger valve part periphery in the driving device concerning 3rd Embodiment was pushed up.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Driving machine 2 Accumulation chamber 3 Cylinder 4b Driver blade 4a Piston 4c Tip part 5 Fastening 6 Trigger valve part 7 Plunger 8 Main valve chamber 9 Valve piston 10 Outer valve bush 11 Inner valve bush 12 Spring 13 Trigger valve chamber 14 Air passage 15 O ring 16 Trigger valve control passage 17 O ring 18 O ring 19 Main valve 20 Air passage 20 Air passage 21 O ring 22 Air passage 23 O ring 24 O ring 25 O ring 26 Main valve portion 27 Main valve rubber 28 Main Valve spring 29 Air passage 30 Exhaust rubber 31 O-ring 32 O-ring 33 Return air chamber 34 Check valve 35 Air passage 36 Air passage 37 Piston bumper 38 Operation section 39 Trigger 40 Main valve control passage 41 Nose 43 Injection unit 44 Magazine 45 Feed mechanism 46 Sequential injection port 48 Arm plate 49 Exhaust hole 51 Round 60A Handle 60 Frame 61 Main valve defining unit 63 Exhaust pipe

Claims (19)

A frame that internally defines a pressure accumulating chamber for storing compressed air;
A cylindrical cylinder provided in the frame;
A piston provided in the cylinder so as to be reciprocally slidable;
A push lever in contact with the workpiece,
A trigger that is an operation input unit;
A main valve provided in the cylinder so as to be reciprocally slidable, and alternatively forming a passage from the piston upper chamber defined by the upper surface of the piston and the inner surface of the cylinder to the pressure accumulating chamber and a passage to the atmosphere; ,
A main valve chamber defining section for defining a main valve chamber for housing the main valve;
A trigger valve for selectively communicating and blocking a passage from the pressure accumulation chamber to the main valve chamber and a passage from the main valve chamber to the atmosphere;
A main valve control passage portion extending from the main valve chamber and defining a main valve control passage communicating with the trigger valve;
The trigger valve is provided with a trigger valve outer frame portion which is an outer shell of the trigger valve, and is provided in the trigger valve outer frame portion so as to be capable of reciprocating sliding. One surface of the trigger valve faces the pressure accumulating chamber. A valve piston that selectively connects and disconnects a passage that communicates from the main valve control passage to the accumulator and a passage that communicates from the main valve control passage to the atmosphere with the valve outer frame portion; and the trigger valve outer frame portion. A trigger penetrating into the valve piston, and a trigger valve control passage is provided in a gap portion of the penetrating portion through which the plunger penetrates the trigger valve outer frame, and the valve piston slides. A trigger valve chamber is defined by the other surface of the moving direction and the outer frame of the trigger valve, and the plunger penetrates the trigger valve chamber to move the trigger and cover the push lever. Vertically slide on the basis of the contact to write material, alternatively communicating the passage to the atmosphere from the passage and the trigger valve chamber from accumulating chamber until the trigger valve chamber, the driving machine to be shut off,
The value obtained by dividing the volume of the main valve chamber by the cross-sectional area of the main valve control passage is 1.0 or less, and the cross-sectional area of the passage that passes through the trigger valve from the main valve control passage and communicates with the atmosphere is main. A driving machine characterized by having a cross-sectional area larger than that of the valve control passage.   2. The driving machine according to claim 1, wherein a value obtained by dividing the volume of the main valve chamber by the cross-sectional area of the main valve control passage is 0.8 or less.   The driving machine according to claim 1, wherein a value obtained by dividing the volume of the main valve chamber by the cross-sectional area of the main valve control passage is 0.6 or less.   The driving machine according to any one of claims 1 to 3, wherein a value obtained by dividing the volume of the trigger valve chamber by the cross-sectional area of the trigger valve control passage is 0.20 or less.   4. The driving machine according to claim 1, wherein a value obtained by dividing the volume of the trigger valve chamber by the cross-sectional area of the trigger valve control passage is 0.15 or less.   4. The driving machine according to claim 1, wherein a value obtained by dividing the volume of the trigger valve chamber by the cross-sectional area of the trigger valve control passage is 0.10 or less.   7. The main valve control passage includes a bent portion in the middle of the passage, and the bent portion is formed of an arc shape or at least two refracting portions. The driving machine described.   The driving machine according to claim 7, wherein a bending angle of the bent portion is 100 ° or more. A frame that internally defines a pressure accumulating chamber for storing compressed air;
A cylindrical cylinder provided in the frame;
A piston provided in the cylinder so as to be reciprocally slidable;
A push lever in contact with the workpiece,
A trigger that is an operation input unit;
A main valve provided in the cylinder so as to be reciprocally slidable, and alternatively forming a passage from the piston upper chamber defined by the upper surface of the piston and the inner surface of the cylinder to the pressure accumulating chamber and a passage to the atmosphere; ,
A main valve chamber defining section for defining a main valve chamber for housing the main valve;
A trigger valve for selectively communicating and blocking a passage from the pressure accumulation chamber to the main valve chamber and a passage from the main valve chamber to the atmosphere;
A main valve control passage portion extending from the main valve chamber and defining a main valve control passage communicating with the trigger valve;
The trigger valve is formed based on a trigger valve outer frame portion that forms an outer periphery of the trigger valve and defines a trigger valve chamber, and an operation of the trigger and abutment of the push lever on a workpiece. A plunger that slides up and down through the trigger valve outer frame and the trigger valve chamber, and selectively communicates and blocks the passage from the pressure accumulation chamber to the trigger valve chamber and the passage from the trigger valve chamber to the atmosphere. In a driving machine equipped with
The value obtained by dividing the volume of the main valve chamber by the cross-sectional area of the main valve control passage is 1.0 or less, and the cross-sectional area of the passage that passes through the trigger valve from the main valve control passage and communicates with the atmosphere is main. A driving machine characterized by having a cross-sectional area larger than that of the valve control passage.   The driving machine according to claim 9, wherein a value obtained by dividing the volume of the main valve chamber by the cross-sectional area of the main valve control passage is 0.8 or less.   11. The driving machine according to claim 9, wherein a value obtained by dividing the volume of the main valve chamber by the cross-sectional area of the main valve control passage is 0.6 or less.   12. The main valve control passage includes a bent portion in the middle of the passage, and the bent portion is formed in an arc shape or at least two refracting portions. The driving machine described.   The driving machine according to claim 11, wherein a bending angle of the bent portion is 100 ° or more. A frame that internally defines a pressure accumulating chamber for storing compressed air;
A cylindrical cylinder provided in the frame;
A piston provided in the cylinder so as to be reciprocally slidable;
A trigger that is an operation input unit;
A trigger valve that selectively forms a passage from the piston upper chamber to the pressure accumulating chamber and a passage to the atmosphere defined by an upper surface of the piston and an inner surface of the cylinder,
The trigger valve is provided with a trigger valve outer frame portion which is an outer shell of the trigger valve, and is provided in the trigger valve outer frame portion so as to be capable of reciprocating sliding. One surface of the trigger valve faces the pressure accumulating chamber. A valve piston for selectively communicating and blocking a passage communicating from the piston upper chamber connected to the valve outer frame portion to the pressure accumulating chamber and a passage communicating from the piston upper chamber to the atmosphere; and the trigger valve outer frame portion. A trigger penetrating into the valve piston, and a trigger valve control passage is provided in a gap portion of the penetrating portion through which the plunger penetrates the outer frame of the trigger valve. A trigger valve chamber is defined by the other surface in the moving direction and the outer frame portion of the trigger valve, and the plunger penetrates the trigger valve and slides up and down based on the operation of the trigger. Alternatively communicating passage from the passage and the trigger valve chamber until the trigger valve chamber to the atmosphere, the driving machine to be shut off,
A driving machine characterized in that a value obtained by dividing the volume of the trigger valve chamber by the cross-sectional area of the trigger valve control passage is 0.20 or less.   15. The driving machine according to claim 14, wherein a value obtained by dividing the volume of the trigger valve chamber by the cross-sectional area of the trigger valve control passage is 0.15 or less.   16. The driving machine according to claim 14, wherein a value obtained by dividing the volume of the trigger valve chamber by the cross-sectional area of the trigger valve control passage is 0.10 or less. A frame that internally defines a pressure accumulating chamber for storing compressed air;
A cylindrical cylinder provided in the frame;
A piston provided in the cylinder so as to be reciprocally slidable;
A main valve that communicates and blocks a passage from the piston upper chamber defined by the upper surface of the piston and the inner surface of the cylinder to the pressure accumulating chamber;
A main valve chamber defining section for defining a main valve chamber for housing the main valve;
A trigger valve for selectively communicating and blocking a passage from the pressure accumulation chamber to the main valve chamber and a passage from the main valve chamber to the atmosphere;
A main valve control passage portion extending from the main valve chamber and defining a main valve control passage communicating with the trigger valve;
A driving machine characterized in that a value obtained by dividing the volume of the main valve chamber by the cross-sectional area of the main valve control passage is 1.0 or less.   18. The driving machine according to claim 17, wherein a value obtained by dividing the volume of the main valve chamber by the cross-sectional area of the main valve control passage is 0.8 or less.   The driving machine according to claim 17 or 18, wherein a value obtained by dividing the volume of the main valve chamber by the cross-sectional area of the main valve control passage is 0.6 or less.

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