Driving tool

Abstract

The present invention provides a driving tool. For a driving tool that performs driving on the condition that both the trigger and the contact arm are triggered and operated, when it is picked up and carried while maintaining the trigger operation, even if the contact arm interferes with other parts, an accidental driving action will not be performed. For the setting of a predetermined time from the trigger operation of the trigger to the locking of the trigger operation of the contact arm, if a rotary damper filled with silicone oil or the like is used, it will be affected by the surrounding heat. The present invention is not affected by heat and ensures a stable time. The predetermined time for the contact limiting member (23) to reach the locking position from the unlocking position is set by the inertial force generated by the rotation of the flywheel (43) rather than by a rotary damper. The rotation action of the flywheel (43) is increased in speed significantly by a multi-stage gear train (30) and made high-speed. The inertial force of the flywheel (43) is used as the acting resistance for the contact limiting member (23) to set the predetermined time.

Description

Technical Field

[0001] The present disclosure relates to driving tools such as nailers. Background Art

[0002] For example, in the case of a nailer powered by compressed air, the driving action is performed by the tool main body on the condition that both an operation of pressing the contact arm provided at the tip of the head of the driving machine against the material to be driven and moving it relatively upward with respect to the ejection port (trigger operation of the contact arm) and an operation of pulling the operation trigger with a fingertip (trigger operation of the trigger) are performed. If only one trigger operation is performed, the driving action is not performed, thereby avoiding an accidental driving action.

[0003] In addition, such a driving tool can perform various driving actions such as aiming driving and swinging driving. Among them, aiming driving is performed by first pressing the contact arm against the material to be driven to trigger the operation and then pulling the operation trigger. Swinging driving is performed by shaking the driving tool up and down while keeping the trigger pulled to trigger and untrigger the contact arm. In the case of the former aiming driving, after the driving action, the next driving action (single-shot driving) cannot be performed without temporarily untriggering the trigger. In contrast, in the case of the latter swinging driving, the driving action (continuous firing driving) can be continuously performed by repeatedly triggering and untriggering the contact arm while keeping the trigger pulled.

[0004] In Patent Document 1, a technique is disclosed in which an electronically controlled solenoid valve is used to operate a head valve that switches between supplying and cutting off compressed air to a driving unit. In Patent Documents 2 and 3, a driving tool having a structure that uses an electronically controlled solenoid valve to switch between continuous firing driving and single-shot driving is disclosed. By using an electronically controlled solenoid valve (starting valve), driving actions such as single-shot driving and continuous firing driving are appropriately controlled. However, the techniques disclosed in Patent Documents 1 to 3 use compressed air as part of the power source for moving the valve stem of the starting valve, and thus there is a problem that the opening and closing actions of the starting valve require time and the rapid firing performance of the driving action is poor.

[0005] In Patent Document 4, a mode switching technique is disclosed, which has the following configuration: a microswitch is used to independently detect the trigger operation of the contact arm and the trigger operation of the trigger, and a timer measures the elapsed time after the trigger operation of the contact arm. According to the mode switching technique disclosed in Patent Document 4, in the single-shot firing mode, before the elapse of a predetermined time after the trigger operation of the contact arm, the firing action is executed by triggering the trigger. The prohibited state of consecutive firing actions after one firing action is reset by the non-trigger operation of the trigger. In the continuous firing mode, before the elapse of a predetermined time after the trigger operation of the trigger, the reset of the timer and the firing action can be repeated on the condition that the trigger operation of the contact arm is executed. When the trigger operation of the contact arm is not executed within the predetermined time measured by the timer, subsequent trigger operations become invalid and the firing action is prohibited. Alternatively, by engaging the locking pin with the contact arm and locking the contact arm in the non-trigger position, the firing action is also prohibited. According to this mode switching technique, for example, in the continuous firing mode, when the handle part is held and the trigger operation is kept unchanged and the contact arm is accidentally brought into contact with other parts, accidental firing actions can be avoided.

[0006] According to the technique disclosed in Patent Document 4, since a manually operated starting valve is used, there is no problem of poor rapid firing performance. However, there is the following problem: when the remaining battery power decreases and the power supply to the microswitch, the controller that receives the input signal of the microswitch and operates, etc. is interrupted or the power supply is cut off, the firing action cannot be executed at all, so the operation has to be aborted. This is also the case for the techniques disclosed in Patent Documents 1 to 3. If the power supply stops, the starting valve does not operate first, so the firing action cannot be performed at all.

[0007] Regarding this point, according to the driving tool disclosed in Patent Document 5, it is a structure that uses a mechanical timer mechanism to prevent accidental trigger operations of the contact arm, so the driving operation can be performed even in an environment without power supply.

[0008] Patent Document 1: US Patent No. 5732870 Specification

[0009] Patent Document 2: US Patent Publication No. 2014 / 0110450 Gazette

[0010] Patent Document 3: US Patent Publication No. 2014 / 0110452 Gazette

[0011] Patent Document 4: Japanese Patent No. 3287172 Gazette

[0012] Patent Document 5: Japanese Unexamined Patent Application Publication No. 2018 - 144122 Gazette Summary of the Invention

[0013] However, the timer mechanism disclosed in Patent Document 5 has a structure using a rotary damper filled with silicone oil, so there is a problem that the operating speed is unstable due to heat influence. In the present disclosure, the timer mechanism is not affected by heat and operates at a stable operating speed.

[0014] According to the features of the present disclosure, the driving tool has a tool main body portion, and the tool main body portion performs a driving action on the condition that both the movement of the trigger to the trigger actuation position and the movement of the contact arm to the arm actuation position are executed. The driving tool is provided with a timer mechanism, and the timer mechanism starts to operate when the contact arm remains in the non-trigger position of the arm and the trigger moves to the trigger actuation position. The timer mechanism has a flywheel that rotates due to the movement of the trigger to the trigger actuation position. The timer mechanism has a contact restricting member that can move between an unlocked position that allows the movement of the contact arm to the arm actuation position and a locked position that restricts the movement of the contact arm to the arm actuation position. The predetermined time required for the movement action of the contact restricting member from the unlocked position to the locked position due to the movement of the trigger to the trigger actuation position is defined by the inertial force generated by the rotation of the flywheel.

[0015] Therefore, when the trigger is in the non-trigger position of the trigger, the contact restricting member is in the unlocked position. In a state where the contact restricting member is in the unlocked position, the movement of the contact arm to the contact actuation position is allowed. When the trigger is moved to the trigger actuation position, the contact restricting member of the timer mechanism takes a predetermined time to move from the unlocked position to the locked position. In a state where the contact restricting member is in the locked position, the movement of the contact arm to the arm actuation position is restricted. Thereby, an accidental driving action of the tool main body portion is avoided. The predetermined time for the contact restricting member to move from the unlocked position to the locked position is defined by the inertial force generated by the rotation of the flywheel. Therefore, it is possible to eliminate the heat influence in the case of the conventional structure that sets a predetermined time using a rotary damper filled with silicone oil, and ensure the stable operating speed of the timer mechanism.

[0016] According to another feature of the present disclosure, there is a support member that supports the flywheel so as to be rotatable. The flywheel has a support shaft whose both end portions are supported by the support member. At least one of the both end portions of the support shaft is conical with a diameter decreasing toward the support member. Therefore, the rotational resistance of the flywheel with respect to the support member can be reduced. Thereby, it is possible to increase the inertial force by increasing the speed of the flywheel.

[0017] According to another feature of the present disclosure, the support member has a first support wall that rotatably supports the first end of the support shaft of the flywheel, and a second support wall that rotatably supports the second end of the support shaft. The first support wall and the second support wall are elastically connected via a connecting portion. The first support wall elastically abuts against the first end of the support shaft by the elastic force of the connecting portion. The second support wall elastically abuts against the second end of the support shaft by the elastic force of the connecting portion. Thus, the rotational resistance of the first end and the second end of the support shaft with respect to the first support wall and the second support wall is reduced. Thereby, the stabilization of the predetermined time of the contact restricting member from the unlocked position to the locked position is achieved.

[0018] According to another feature of the present disclosure, the timer mechanism has a multi-stage gear train that speeds up the rotational movement that is forced and performed due to the movement of the trigger to the trigger actuation position and transmits it to the flywheel. By speeding up the gear train, a larger inertial force can be generated with a smaller flywheel.

[0019] According to another feature of the present disclosure, there is a mechanism housing that encloses and houses the flywheel and the gear train. There is a sealing member that seals between the support portion that extends and protrudes from the mechanism housing of the contact restricting member and the mechanism housing. Thus, dust prevention (prevention of foreign matter from entering) of the flywheel and the gear train is achieved. Thereby, the stabilization of the predetermined time defined by the inertial force of the flywheel is achieved.

[0020] According to another feature of the present disclosure, at least two gears in the gear train are coaxially arranged. Thus, the compactification of the gear train is achieved.

[0021] According to another feature of the present disclosure, there is a clutch mechanism provided in the power transmission path of the gear train. Thus, by using the clutch mechanism to cut off the power transmission path of the gear train, the trigger can quickly return to the non-trigger position without being affected by the inertial force of the flywheel.

[0022] According to another feature of the present disclosure, the clutch mechanism is a one-way clutch. Thus, for a predetermined time defined by the inertial force of the flywheel, a simple structure is used to ensure an appropriate time and quickly return the trigger to the non-trigger position.

[0023] According to another feature of the present disclosure, there is a gear train base that supports the gear train and is composed of a single component. Thus, the multi-stage gear train is assembled on the gear train base with stable accuracy. Thereby, the stabilization of the predetermined time defined by the inertial force of the flywheel is achieved.

[0024] According to another feature of the present disclosure, the mechanism housing has a shielding wall portion that shields the contact limiting member from the side. A window portion for visually observing the contact limiting member from the side is provided in the shielding wall portion. Thus, the operation state of the timer mechanism can be quickly confirmed. The dust-proof state inside the mechanism housing (no malfunction caused by the intrusion of foreign objects, etc.) can be indirectly confirmed by visually observing the operation state of the contact limiting member through the window portion. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a left view of the driving tool.

[0026] Figure 2 is a right view of the driving tool.

[0027] Figure 3 is a longitudinal sectional view of the tool main body portion.

[0028] Figure 4 is a perspective view of the timer mechanism.

[0029] Figure 5 is Figure 4 the view in the direction V in [figure number], which is the front view of the timer mechanism.

[0030] Figure 6 is Figure 5 the sectional view taken along the line VI-VI in [figure number].

[0031] Figure 7 is an exploded perspective view of the timer mechanism.

[0032] Figure 8 is the front view of the timer mechanism.

[0033] Figure 9 is Figure 8 the sectional view taken along the line IX-IX in [figure number].

[0034] Figure 10 is a perspective view of the timer mechanism. This figure shows the initial state where the contact limiting member is in the unlocked position.

[0035] Figure 11 is a perspective view of the gear train base.

[0036] Figure 12 is an exploded perspective view of the flywheel and the spacing limiting member disassembled from the gear train base.

[0037] Figure 13 is Figure 4 the view in the direction XIII in [figure number], which is a perspective view of the timer mechanism observed from the lower right obliquely. In this figure, the contact limiting member is shown in the unlocked position, and the contact limiting member cannot be visually observed through the window portion.

[0038] Figure 14 This is a perspective view of the timer mechanism observed from the lower right obliquely. In this figure, the movement of the contact limiting member towards the locking position is shown, and the state of the contact limiting member can be visually observed through the window portion.

[0039] Figure 15 This is a perspective view of the timer mechanism observed from the upper left obliquely. This figure shows the initial state of the starting device, showing the non-triggered state of the trigger and the non-triggered state of the contact arm.

[0040] Figure 16 This is a perspective view of the timer mechanism observed from the lower right obliquely. This figure shows the initial state of the starting device, showing the non-triggered state of the trigger and the non-triggered state of the contact arm.

[0041] Figure 17 This is a perspective view of the timer mechanism observed from the lower right obliquely. This figure shows the non-triggered state of the trigger and the triggered operation state of the contact arm.

[0042] Figure 18 This is a perspective view of the timer mechanism observed from the lower right obliquely. This figure shows the triggered operation state of the trigger and the triggered operation state of the contact arm.

[0043] Figure 19 This is a perspective view of the timer mechanism observed from the upper left obliquely. This figure shows the triggered operation state of the trigger and shows the locked state in which the triggered operation of the contact arm is restricted.

[0044] Figure 20 This is a perspective view of the timer mechanism observed from the lower right obliquely. This figure shows the triggered operation state of the trigger and shows the locked state in which the triggered operation of the contact arm is restricted.

[0045] Explanation of Reference Numerals

[0046] W... Material to be driven in; T... Driving piece; 1... Driving tool; 2... Tool main body; 2a... Head valve; 2b... Compression spring; 3... Handle part; 3a... Accumulator chamber; 4... Driving machine head; 5... Driving piece magazine; 6... Contact arm; 6a... Contact part; 6b... Extension part; 6c... Actuating part; 6d... Locking part; 7... Trigger lock lever; 8... Base part; 10... Starting device; 11... Starting valve; 11a... Valve rod; 11b... Compression spring; 12... Trigger; 12a... Torsion spring; 12b... Restriction release part; 13... Piston; 14... Impact driver; 15... Cylinder; 15a... Return air chamber; 15b... Vent hole; 16... Piston upper chamber; 17... Starting base; 17a... Shielding wall part; 17b... Holding recess; 17c... Guide groove part; 17d... Window part; 18... Support shaft; 19... Idler gear; 19a... Support shaft; 20... Timer mechanism; t... Predetermined time; 21... Mechanism housing; 21a... Right side wall part; 23... Contact restriction part; 23a... Support part; 23b... Restriction part; 23c... Release receiving part; 24... Cover part; 24a... Fixing screw; 25... Gear train base; 25a... Left side wall part; 25b... Right side wall part; 25c... First support wall (left side); 25d... Second support wall (right side); 25e, 25f... Holding recesses; 25g... Connecting part; 25h... Limit claw part; 26... Support shaft; 27... Sealing part; 28... First gear; 28a... Support part; 28b... Spring engaging part; 29... Torsion spring; 30... Gear train; 31... First row shaft; 32... Second row shaft; 33... Second gear; 34... Third gear; 35... Clutch mechanism (one-way clutch); 36... Compression spring; 37... Fourth gear; 38... Fifth gear; 40... Sixth gear; 41... Seventh gear; 42... Eighth gear; 43... Flywheel; 45... Spacing holding part; 45a... Gear anti-interference part; 45b... Shaft anti-interference part; 45c... Flywheel anti-interference part; 46... Support shaft; 46a... First end; 46b... Second end. Detailed implementation mode

[0047] Next, based on Figures 1 to 20 the implementation mode of the present invention will be described. As Figures 1 to 3 shown, in this implementation mode, as an example of the driving tool 1, a compressed air-driven nail gun is exemplified. The driving tool 1 has a tool main body 2, and a piston 13 that reciprocates up and down in the cylinder 15 with compressed air as the power source is installed in the tool main body 2. A handle part 3 is provided in a state of protruding laterally from the side part of the tool main body 2. A driving machine head 4 is provided at the lower part of the tool main body 2. The driving machine head 4 extends downward (the driving direction of the driving piece T). The driving tool 1 is provided with a driving piece magazine 5, and the driving piece magazine 5 is equipped to straddle between the driving machine head 4 and the handle part 3 and can be loaded with many driving pieces.

[0048] In the following description, the driving direction of the driving piece T is denoted as the lower side, and the opposite direction of the driving direction is denoted as the upper side. The user of the driving tool 1 holds the handle portion 3 behind the driving tool 1 ( Figure 1 the right side in)

[0049] A contact arm 6 is supported at the top end of the driving machine head 4, and the contact arm 6 is capable of moving relatively up and down. Pressing the contact arm 6 against the material W to be driven and moving it relatively upward is one of the conditions for performing the driving action. The contact arm 6 extends in the range from near the top end of the driving machine head 4 to near the trigger 12. A ring-shaped abutting portion 6a is provided at the lower part of the contact arm 6. The abutting portion 6a is located at the top end of the driving machine head 4 and is located around the ejection port. As Figure 2 shown, a strip-shaped extension portion 6b is joined to the abutting portion 6a. The extension portion 6b extends upward. As Figure 3 shown, an operating portion 6c is provided at the upper part of the extension portion 6b. The operating portion 6c reaches near the lower side of the trigger 12. The contact arm 6 having the integral abutting portion 6a, extension portion 6b, and operating portion 6c is supported so as to be able to move up and down within a certain range along the driving machine head 4.

[0050] Near the base of the handle portion 3 and on the side portion of the tool main body portion 2, the starting device 10 of the present embodiment is arranged. By the starting operation of the starting device 10, the starting valve 11 is opened. When the starting valve 11 is opened, compressed air is supplied to the piston upper chamber 16 of the tool main body portion 2. When compressed air is supplied to the piston upper chamber 16, the piston 13 moves downward in the cylinder 15, and the driving action is performed. A long rod-shaped impact driver 14 is mounted on the lower surface of the piston 13. The impact driver 14 moves downward in the driving machine head 4 (driving passage) as the piston 13 moves downward, and thereby one driving piece T is ejected from the top end (ejection port) of the driving machine head 4. The driving pieces T are successively supplied from the driving piece magazine 5 into the driving machine head 4 in linkage with the driving action.

[0051] As Figure 1 shown, a trigger locking lever 7 is provided on the side of the starting device 10. In the state where the trigger locking lever 7 is rotated downward as Figure 1 shown, the upward pulling operation of the trigger 12 can be performed. In the state where the trigger locking lever 7 is rotated counterclockwise (upward) in Figure 1 by about 90°, a trigger locking state where the upward pulling operation of the trigger 12 cannot be performed is formed. The trigger locking lever 7 is switched to the upper locking position, thereby preventing the unintentional pulling operation of the trigger 12 and avoiding the accidental driving action of the driving tool 1.

[0052] The starting device 10 of the present embodiment has features that have not been present in the past. The basic structure of the driving tool 1 does not require special changes in the present embodiment, and thus a detailed description thereof is omitted. The starting device 10 has a function of opening the starting valve 11 on the condition that both the trigger operation of the trigger 12 and the trigger operation of the contact arm 6 are performed. The starting device 10 of the present embodiment includes the above-described starting valve 11, trigger 12, and timer mechanism 20. As Figure 3 shown, the starting valve 11 is housed in the lower surface on the base side of the handle portion 3. The lower portion of the valve stem 11a projects toward the trigger 12. The valve stem 11a of the starting valve 11 is supported so as to be movable up and down (movable to the trigger position and the non-trigger position). The valve stem 11a is urged by a compression spring 11b in the direction of moving toward the lower non-trigger position. Figure 3 The state in which the valve stem 11a is located at the non-trigger position is shown. The valve stem 11a moves upward from this non-trigger position against the urging force of the compression spring 11b, thereby opening the starting valve 11.

[0053] When the starting valve 11 is opened, due to the air pressure acting downward, the head valve 2a is displaced downward to open. When the head valve 2a is opened, the compressed air accumulated in the pressure accumulation chamber 3a in the handle portion 3 is supplied to the piston upper chamber 16. When the valve stem 11a returns downward due to the spring urging force, the starting valve 11 closes. When the starting valve 11 closes, the head valve 2a is displaced upward due to the air pressure acting upward and the urging force of the compression spring 2b, whereby the piston upper chamber 16 is closed with respect to the pressure accumulation chamber 3a. The piston upper chamber 16 is closed and opened to the atmosphere at the same time. In addition, the compressed air flowing into the return air chamber 15a acts on the lower surface side of the piston 13 that has moved downward via the vent hole 15b. Due to the compressed air acting on the lower surface side, the piston 13 that has moved downward returns to the top dead center (initial position).

[0054] As a condition for starting the above series of driving operations (conditions for the moving operation for moving the valve stem 11a of the starting valve 11 to the trigger position), a trigger operation of the trigger 12 to the trigger position and a trigger operation of the contact arm 6 to the arm trigger position are required. First, the trigger operation of the contact arm 6 is performed, and then the trigger operation of the trigger 12 is performed, thereby performing so-called single-shot driving (aimed driving). On the other hand, in the case where the contact arm 6 remains in the arm non-trigger position, the trigger operation of the trigger 12 is first performed, and the trigger operation of the contact arm 6 is performed within a predetermined time, and the driving operation is also performed. In this case, while maintaining the state in which the trigger 12 has been triggered, the trigger operation of the contact arm 6 is repeatedly performed within a predetermined time, thereby enabling so-called continuous firing driving (swinging driving). The predetermined time t from the trigger operation of the trigger 12 to the locking of the trigger operation of the contact arm 6 in the latter case where the trigger operation of the trigger 12 is first performed is set by the timer mechanism 20 to be described below.

[0055] The details of the starting device 10 are as follows Figures 4 to 7 as shown. The starting device 10 is supported by a pedestal portion 8 provided on the rear side of the tool main body portion 2. The starting device 10 includes a starting base 17, a trigger 12, and a timer mechanism 20. The trigger 12 and the timer mechanism 20 are supported by the starting base 17. The starting base 17 is coupled to the pedestal portion 8. As Figure 7 , Figure 13 , Figure 14 shown, a shielding wall portion 17a is provided on the left side portion of the starting base 17, and the shielding wall portion 17a shields the contact limiting member 23 from other components. The shielding wall portion 17a is used to prevent interference of other components with the contact limiting member 23. Thereby, malfunction of the timer mechanism 20 is avoided in advance. In addition, the shielding wall portion 17a is used to achieve dust prevention of the contact limiting member 23. This also avoids malfunction of the contact limiting member 23 in advance. A guide groove portion 17c is provided along the shielding wall portion 17a on the starting base 17. The guide groove portion 17c guides the contact arm 6, mainly the operating portion 6c, up and down. The operating portion 6c moves upward in the guide groove portion 17c and the contact arm 6 is triggered.

[0056] The trigger 12 is supported on the upper portion of the starting base 17. The trigger 12 is supported so as to be able to be operated to rotate up and down by means of a support shaft 18. The trigger 12 is pulled upward by the fingertips of the hand holding the grip portion 3. The position where the pulling operation reaches the upper side is also the position where the starting valve 11 can be opened, which corresponds to the trigger position (trigger position of the trigger) of the trigger 12. The trigger 12 is biased by a torsion spring 12a in the direction of rotating toward the non-trigger position on the lower side.

[0057] The idle pulley 19 is supported so as to be able to rotate up and down by means of a support shaft 19a on the back side (upper surface side) of the trigger 12. The idle pulley 19 is biased by a torsion spring (not shown in the figure) provided around the support shaft 19a in the direction of displacing its rotating end side (front side) upward. Due to the biasing force of the torsion spring, the idle pulley 19 is in a state of always pressing against the top end of the valve stem 11a of the starting valve 11.

[0058] When the trigger 12 is pulled upward (to the trigger - actuated position) and the contact arm 6 is triggered upward (to the arm - actuated position), the rotation - end side of the idler wheel 19 is pushed upward by the actuating portion 6c of the contact arm 6, restricting the downward displacement. As a result, the valve stem 11a is pushed upward, and the starting valve 11 is opened. The upper position where the starting valve 11 can be opened corresponds to the arm - actuated position of the contact arm 6. After the contact arm 6 is triggered to the arm - actuated position, in a state where the trigger 12 is not pulled, the support - shaft 19a side of the idler wheel 19 does not displace, so the starting valve 11 is not opened. After that, by pulling the trigger 12, the starting valve 11 is opened, and single - shot driving is performed. After the trigger 12 is pulled, in a state where the contact arm 6 is not triggered, the rotation - end side of the idler wheel 19 is not pushed upward, so the starting valve 11 is not opened. After that, by triggering the contact arm 6 within a predetermined time, the starting valve 11 is opened, and the driving action is performed.

[0059] As Figure 16 shown, a locking portion 6d for engaging a contact - restricting member 23 described below is formed in a stepped shape on the actuating portion 6c of the contact arm 6. In a state where the contact - restricting member 23 is located above the locking portion 6d, the triggering operation of the contact arm 6 is restricted, becoming a state where the driving action is prohibited.

[0060] A timer mechanism 20 for defining the above - mentioned predetermined time is provided below the trigger 12. The actuating portion 6c of the contact arm 6 is configured to be able to displace vertically along the right - hand side of the starting base 17. The timer mechanism 20 is arranged below the trigger 12. The timer mechanism 20 includes a contact - restricting member 23 and a multi - stage gear train 30. The gear train 30 is housed inside the mechanism housing 21. The mechanism housing 21 is integrally formed on the front - surface side of the starting base 17. The contact - restricting member 23 is arranged outside the mechanism housing 21. The mechanism housing 21 has a rectangular box shape with an open front. The front opening of the mechanism housing 21 is blocked by a cover portion 24. The cover portion 24 is fastened to the mechanism housing 21 with a single fixing screw 24a. The mechanism housing 21 is closed by the cover portion 24, ensuring dust - proofness inside.

[0061] As Figure 6 、 Figure 7As shown, the contact limiting member 23 and the gear train 30 are modularized in a gear train base 25. The contact limiting member 23 and the gear train 30 are installed inside the mechanism housing 21 in a state of being modularized in a gear train base 25. The gear train base 25 is a component formed by performing sheet metal processing such as punching and bending on a steel plate. The contact limiting member 23 is supported by a support shaft 26 so as to be rotatable back and forth on the right side of the gear train base 25. The left end portion of the support shaft 26 is held by the left side wall portion 25a of the gear train base 25. The right end portion of the support shaft 26 is held by a holding recess 17b provided in the shielding wall portion 17a of the starting base 17. The holding recess 17b opens forward. By inserting the right end portion of the support shaft 26 into the holding recess 17b from the front, the operability when assembling the contact limiting member 23 and the gear train 30 to the starting base 17 is ensured. In addition, after modularizing the contact limiting member 23, the gear train 30, and the flywheel 43 in a gear train base 25 and then assembling them to the starting base 17, there is no need to make special changes to the tool main body portion 2 for applying the timer mechanism 20 of this example.

[0062] The contact limiting member 23 includes a cylindrical support portion 23a and a limiting portion 23b protruding radially from the right end portion of the support portion 23a. The support portion 23a penetrates the right wall portion of the mechanism housing 21 and protrudes to the outside. The limiting portion 23b is integrally provided on the protruding end side. A sealing member 27 is provided between the support portion 23a and the right side wall portion 21a of the mechanism housing 21. Thereby, the sealing property (dust prevention property) of the support portion of the contact limiting member 23 supported by the mechanism housing 21 is ensured.

[0063] A first gear 28 is supported on the left side of the support shaft 26. A cylindrical support portion 28a is integrally formed on the first gear 28. The first gear 28 is supported by the support portion 28a so as to be rotatable back and forth. A torsion spring 29 is provided around the support portion 28a. As Figure 8 , Figures 16 to 18 shown, one end side of the torsion spring 29 is engaged with the spring engaging portion 28b of the first gear 28. Although not shown, the other end side of the torsion spring 29 is hooked on the gear train base 25. Therefore, the first gear 28 is biased in the direction of rotating backward by the biasing force of the torsion spring 29.

[0064] The support portion 28a of the first gear 28 and the support portion 23a of the contact limiting member 23 are rotationally integrated with each other. Therefore, both the first gear 28 and the contact limiting member 23 are biased in the direction of rotating backward (contact locking side) by the biasing force of the torsion spring 29. The contact limiting member 23 is biased by the torsion spring 29 toward the locking position side that restricts the movement of the operating portion 6c of the contact arm 6 to the trigger position.

[0065] As Figure 16 , Figure 17As shown, an integral restriction release portion 12b is provided at the front portion (rotation support side) of the trigger 12. In a state where the trigger 12 is in the lower non-trigger position due to the biasing force of the torsion spring 12a, the restriction release portion 12b engages with the release receiving portion 23c of the contact restriction member 23. Thereby, the contact restriction member 23 is held in the forward unlocking position against the torsion spring 29 ( Figure 16 , Figure 17 is pushed upward). In a state where the contact restriction member 23 is in the unlocking position, the movement of the contact arm 6 to the arm trigger position (trigger operation) is permitted.

[0066] In contrast, as Figure 19 shown, when the trigger 12 is triggered (trigger operation) upward to the trigger trigger position as shown by the hollow arrow in the figure, the restriction release portion 12b retracts upward. Therefore, the contact restriction member 23 rotates rearward (locking side) due to the biasing force of the torsion spring 29 as shown by the hollow arrow in Figure 20 the figure. When the contact restriction member 23 reaches the locking position, the movement operation of the contact arm 6 to the arm trigger position is restricted. After the trigger 12 is triggered, a predetermined time t until the contact restriction member 23 reaches the locking position is specified by a timer mechanism 20 to be described below.

[0067] As Figure 8 , Figure 10 , Figure 15 shown, the contact restriction member 23 is connected to a multi-stage gear train 30 via a first gear 28. The rotation of the first gear 28 is increased in speed by the gear train 30 and transmitted to the flywheel 43. Thereby, the rotational movement of the flywheel 43 is speeded up. The first row shaft 31 and the second row shaft 32 are arranged parallel to each other across the left side wall portion 25a and the right side wall portion 25b of the gear train base 25. The second row shaft 32 is arranged below the first row shaft 31.

[0068] A rotatable second gear 33 is supported near the center of the first row shaft 31. The second gear 33 meshes with the first gear 28. The second gear 33 is a spur gear having a diameter smaller than that of the first gear.

[0069] The third gear 34 is coaxially arranged to the right of the second gear 33. The second gear 33 and the third gear 34 are supported so as to be able to rotate independently of each other. An engaged clutch mechanism 35 is provided between the second gear 33 and the third gear 34. The clutch mechanism 35 uses a one-way clutch. In the state where the clutch mechanism 35 is engaged, the second gear 33 and the third gear 34 rotate integrally. The clutch mechanism 35 is biased toward the engaged side by a compression spring 36. When the engagement of the clutch mechanism 35 is disengaged against the compression spring 36, the power transmission path between the second gear 33 and the third gear 34 is disconnected. Therefore, the rotational movement of the contact restricting member 23 toward the unlocking side is disconnected from the inertial forces of the gear train 30 and the flywheel 43 and proceeds rapidly. Thereby, the return movement of the trigger 12 to the non-trigger position is performed rapidly.

[0070] The third gear 34 uses a spur gear having a diameter larger than that of the second gear 33. The third gear 34 meshes with the fourth gear 37. The fourth gear 37 uses a spur gear having a diameter smaller than that of the third gear 34. The fourth gear 37 is supported on the second column shaft 32 so as to be able to rotate. A rotatable fifth gear 38 is supported to the left of the fourth gear 37. The fourth gear 37 and the fifth gear 38 are rotationally integrated with each other. The fourth gear 37 and the fifth gear 38 rotate integrally. The fifth gear 38 meshes with the sixth gear 40. The sixth gear 40 uses a spur gear having a diameter smaller than that of the fifth gear 38.

[0071] The sixth gear 40 is supported on the first column shaft 31 so as to be able to rotate. The sixth gear 40 is rotationally disconnected from the second gear 33 and the third gear 34. An integral seventh gear 41 is provided on the sixth gear 40. The sixth gear 40 and the seventh gear 41 rotate integrally. The seventh gear 41 uses a spur gear having a diameter larger than that of the sixth gear 40 and substantially the same diameter as the third gear 34 and the fifth gear 38.

[0072] The seventh gear 41 meshes with the eighth gear 42. The eighth gear 42 uses a spur gear having a diameter smaller than that of the seventh gear 41 and substantially the same diameter as the second gear 33, the fourth gear 37, and the sixth gear 40.

[0073] As Figure 12 shown, the eighth gear 42 is provided integrally with the support shaft 46. A flywheel (inertia wheel) 43 is provided integrally with the support shaft 46 in parallel with the eighth gear 42. The eighth gear 42 and the flywheel 43 rotate integrally with the support shaft 46.

[0074] As Figure 9 、 Figure 11 、 Figure 12As shown, the support shaft 46 is supported across between the first support wall 25c on the left side and the second support wall 25d on the right side provided on the upper side of the gear train base 25. The first support wall 25c and the second support wall 25d are formed in a substantially mountain shape by cutting a part of the gear train base 25. The first support wall 25c on the left side is set to be substantially flush with the left side wall portion 25a of the gear train base 25. Compared with the right side wall portion 25b of the gear train base 25, the second support wall 25d on the right side is arranged closer to the left side wall portion 25a. The rear portions of the first support wall 25c and the second support wall 25d are joined to each other by a connecting portion 25g. Due to the elastic force of the connecting portion 25g, the first support wall 25c on the left side and the second support wall 25d on the right side are elastic in the directions of approaching and separating from each other. The first support wall 25c, the second support wall 25d, and the connecting portion 25g constitute a support member that supports the flywheel 43 so as to be rotatable.

[0075] Hemispherical holding recesses 25e and 25f are respectively provided at the front portions of the first support wall 25c on the left side and the second support wall 25d on the right side. The left and right holding recesses 25e and 25f are recessed in the directions of separating from each other. On the other hand, the first end 46a on the left side and the second end 46b on the right side of the support shaft 46 are respectively formed in a conical shape with the tip tapering in the direction of becoming a small diameter on the tip side. The first end 46a of the support shaft 46 is elastically abutted and held by the left holding recess 25e. In addition, the second end 46b of the support shaft 46 is elastically abutted and held by the right holding recess 25f. By using this conical shaft holding structure, the rotational resistance of the support shaft 46 is greatly reduced.

[0076] A spacer holding member 45 is inserted between the first support wall 25c and the second support wall 25d. The spacer holding member 45 is fixed along the connecting portion 25g. The spacer holding member 45 limits the interval between the first support wall 25c and the second support wall 25d to a certain interval so that this interval will not become too narrow due to the elastic force. As Figure 12 shown, a semicircular gear interference prevention portion 45a for avoiding interference with the eighth gear 42 and a semicircular shaft interference prevention portion 45b for avoiding interference with the support shaft 46 are provided on the front surface side of the spacer holding member 45. It is possible to apply changes to the spacer holding member 45. For example, a structure in which the spacer holding member is installed on the outer surface sides of the first support wall 25c and the second support wall 25d can also be adopted. Thus, the interval between the first support wall 25c and the second support wall 25d is limited to a certain interval to avoid this interval becoming too wide due to the elastic force.

[0077] A flywheel interference prevention portion 45c for avoiding interference with the flywheel 43 is provided between the gear interference prevention portion 45a and the shaft interference prevention portion 45b. In a portion close to the support shaft 46, a spacer holding member 45 is used to maintain the interval between the first support wall 25c and the second support wall 25d, thereby further reliably maintaining the interval from becoming excessively narrower than the appropriate interval. Thus, the variation in the rotational resistance of the support shaft 46 is further reliably suppressed. An engaging claw portion 25h is provided upright at the upper portion of the connecting portion 25g. By means of the engaging claw portion 25h, the positional deviation of the spacer holding member 45 and the detachment of the spacer holding member 45 from between the first support wall 25c and the second support wall 25d are prevented.

[0078] Due to the above conical shaft holding structure, the rotational resistance of the flywheel 43 is extremely small. The rotational resistance of the flywheel 43 is small, so that it can rotate at a higher speed. In addition, the rotational speed of the flywheel 43 is greatly increased by four-stage speed increase through the gear train 30. Thus, the miniaturization of the flywheel 43 is achieved, and a large inertial force is generated by its rotation. The inertial force of the flywheel 43 is used as the resistance for the operation of the contact limiting member 23 to reach the locking position, thereby appropriately defining the predetermined time t. The compactification of the timer mechanism 20 is achieved by the miniaturization of the flywheel 43.

[0079] In the present embodiment, the predetermined time t required for the contact limiting member 23 to reach the locking position from the unlocking position is set to about 3 to 5 seconds. The predetermined time t can be arbitrarily increased or decreased by changing the speed ratio of the gear train 30 or the like to change the inertial force of the flywheel 43.

[0080] In this way, the inertial force of the flywheel 43 is used as the operation resistance when moving to the locking position, thereby setting the predetermined time t for the rotational operation of the contact limiting member 23 from the unlocking position to the locking position. The timer mechanism 20 configured in this way is located between the trigger 12 and the operating portion 6c of the contact arm 6, thereby preventing an accidental driving operation in the trigger operation state of the trigger 12.

[0081] As described above, when the trigger 12 and the contact arm 6 are respectively trigger-operated, the valve stem 11a is pushed upward by the idler gear 19, and the start valve 11 is opened. Since the start valve 11 is opened, compressed air is supplied to the piston upper chamber 16, and the driving operation is performed. In the driving operation mode (continuous firing) in which the trigger 12 is first trigger-operated and then the contact arm 6 is trigger-operated, after the trigger 12 is trigger-operated, after the predetermined time t set by the above timer mechanism 20 has elapsed, the trigger operation of the contact arm 6 is prohibited. The trigger operation prohibition state of the contact arm 6 is reset by releasing the trigger operation of the trigger 12. In addition, in the driving operation mode (single firing) in which the contact arm 6 is first trigger-operated and then the trigger 12 is trigger-operated, there is no time limit caused by the above timer mechanism 20. Hereinafter, the operation state of the timer mechanism 20 will be described for each operation mode.

[0082] Figure 15 and Figure 16 shows the non-trigger state of the trigger 12 and the non-trigger state (initial state) of the contact arm 6. As Figure 16 shown, in this initial state, the release receiving part 23c is pushed forward by the restriction release part 12b of the trigger 12. Therefore, the contact restriction member 23 is in a state of being pushed upward to the unlocked position in the front. In this initial state, as Figure 17 shown, when the operation contact arm 6 is first moved upward, the operation part 6c passes behind the restriction part 23b of the contact restriction member 23 and comes to the trigger position. Thereby, the trigger operation of the contact arm 6 is permitted. When the contact arm 6 is trigger-operated, the rotation end side of the idler wheel 19 is pushed upward by the operation part 6c. Therefore, when the trigger 12 is trigger-operated thereafter, the start valve 11 opens. Thereby, a single-shot firing is performed.

[0083] Next, in order to perform continuous firing, in the initial state shown in Figure 15 and Figure 16 shown, as Figures 18 to 20 shown, when the trigger 12 is first trigger-operated upward, the timer mechanism 20 operates. When the trigger 12 is trigger-operated upward, the restriction release part 12b is displaced upward. Therefore, the release receiving part 23c can be displaced upward. Thereby, the contact restriction member 23 starts to rotate toward the locking side (the rear side in Figures 18 to 20 ) due to the torsion spring 29. When the contact restriction member 23 rotates toward the locking side, the restriction part 23b is displaced rearward (locking side). Thereby, the restriction part 23b enters the guide groove part 17c of the start base 17.

[0084] As Figure 18 shown, before the elapse of a predetermined time t after the trigger 12 is trigger-operated, when the contact arm 6 is trigger-operated, the restriction part 23b of the contact restriction member 23 has not reached the locking position yet, so the operation part 6c goes upward in the guide groove part 17c. Thereby, the contact arm 6 is trigger-operated. The trigger 12 is trigger-operated, and then the contact arm 6 is trigger-operated, whereby the start valve 11 is opened and the firing action is performed.

[0085] If the contact arm 6 is not trigger-operated before the elapse of a predetermined time t after the trigger 12 is trigger-operated, then as Figure 19 and Figure 20As shown, the restricting portion 23b of the contact restricting member 23 enters the locking state within the guiding groove portion 17c. In this locked state, the locking portion 6d of the actuating portion 6c abuts against the restricting portion 23b, restricting further upward displacement of the actuating portion 6c. In this locked state, the triggering operation of the contact arm 6 is restricted, and thus the start valve 11 is not opened. Therefore, the driving action is not performed on the tool main body portion 2. The locked state of the contact arm 6 is reset by releasing the triggering operation of the trigger 12.

[0086] After a single-shot driving, when the triggering operation of the trigger 12 is maintained and the contact arm 6 is not triggered, the contact restricting member 23 becomes a state capable of rotating toward the locking side. In addition, since the triggering operation of the trigger 12 is maintained, the restricting release portion 12b is in a state of moving upward from the release receiving portion 23c and separating from the release receiving portion 23c. Therefore, after a single driving action during single-shot driving, when the contact arm 6 returns to the non-trigger position, the timer mechanism 20 starts to operate. Therefore, thereafter, if the contact arm 6 is triggered again before the elapse of a predetermined time t, continuous driving can be performed. After the elapse of the predetermined time t, the triggering operation of the contact arm 6 is prohibited, whereby an accidental driving action is prohibited. The timer mechanism 20 operates when the trigger 12 is triggered and the contact arm is in the non-trigger state.

[0087] As Figure 13 , Figure 14 shown, a circular window portion 17d is provided in the shielding wall portion 17a of the start base 17. As Figure 14 shown, when the restricting portion 23b of the contact restricting member 23 reaches the locking position after the elapse of the predetermined time t, the window portion 17d is blocked by the restricting portion 23b. Therefore, the user can visually observe the presence of the restricting portion 23b through the window portion 17d. Thereby, the user can confirm the locked state of the contact arm 6. In addition, it is possible to confirm that the contact restricting member 23 operates normally through visual observation. As Figure 13 shown, in a state where the contact restricting member 23 is located at the unlocking position, the window portion 17d is not blocked by the restricting portion 23b. Thereby, the user can confirm the unlocked state of the contact arm 6.

[0088] According to the driving tool 1 configured as described above, during continuous driving performed by first triggering the trigger 12, after the elapse of a predetermined time t after the trigger 12 is triggered, the triggering operation of the contact arm 6 is prohibited. Thereby, an accidental driving action when accidentally holding the driving tool 1 with the trigger 12 held in the depressed state is reliably prevented.

[0089] In addition, in the illustrated timer mechanism 20, the inertial force of the flywheel 43 is used to set a predetermined time t. Therefore, it does not include a structure with an operating portion powered by, for example, compressed air, so the timer mechanism 20 can operate smoothly. In addition, it is not affected by the surrounding heat as in the case of using a rotary damper filled with silicone oil or the like to set a time equivalent to the predetermined time t, so the driving operation is always controlled at a stable predetermined time t.

[0090] Furthermore, according to the illustrated timer mechanism 20, the first end 46a and the second end 46b of the support shaft 46 that supports the flywheel 43 so as to be rotatable are formed into a conical shape with a smaller diameter toward the top end side. The first end 46a and the second end 46b of the support shaft 46 are held in the holding recess 25e of the first support wall 25c and the holding recess 25f of the second support wall 25d. Thereby, the rotational resistance of the flywheel 43 with respect to the first support wall 25c and the second support wall 25d is extremely small. Thereby, the inertial force of the flywheel 43 can be large.

[0091] In addition, according to the illustrated timer mechanism 20, there is a first support wall 25c that supports the first end 46a of the support shaft 46 of the flywheel 43 so as to be rotatable and a second support wall 25d that supports the second end 46b of the support shaft 46 so as to be rotatable. The first support wall 25c and the second support wall 25d are elastically connected via a connecting portion 25g. By the elastic force of the connecting portion 25g, the first support wall 25c elastically abuts against the first end 46a of the support shaft 46. By the elastic force of the connecting portion 25g, the second support wall 25d elastically abuts against the second end 46b of the support shaft 46. Therefore, the rotational resistance of the first end 46a and the second end 46b of the support shaft 46 with respect to the first support wall 25c and the second support wall 25d is reduced. Thereby, the rotational operation of the flywheel 43 is stabilized, and the stabilization of the predetermined time t for the contact restricting member 23 to reach the locking position from the unlocking position is achieved.

[0092] Furthermore, the timer mechanism 20 has a multi-stage gear train 30 that is urged by a torsion spring 29 to rotate due to the movement of the trigger 12 to the trigger position (trigger trigger position). The flywheel 43 is speeded up by the speed increase of the gear train 30. The diameter of the flywheel 43 can be reduced by speeding up, and a large inertial force is generated by its rotational operation.

[0093] In addition, according to the illustrated timer mechanism 20, there is a mechanism housing 21 that encloses and houses the flywheel 43 and the gear train 30. The space between the support portion 23a of the contact restricting member 23 protruding from the mechanism housing 21 and the mechanism housing 21 is sealed by a sealing member 27. Thereby, dust prevention (prevention of foreign matter from entering) of the flywheel 43 and the gear train (timer mechanism 20) is achieved. Thereby, the stabilization of the predetermined time t is achieved.

[0094] The first-stage speed increasing section of the gear train 30 (the meshing section of the first gear 28 and the second gear 33) and the third-stage speed increasing section (the meshing section of the fifth gear 38 and the sixth gear 40) are coaxially arranged on the first column shaft 31. Thereby, the gear train 30 is made compact.

[0095] The gear train 30 has a clutch mechanism 35 in the power transmission path. By using the clutch mechanism 35 to cut off the power transmission path of the gear train 30, the trigger 12 can quickly return to the non-trigger position without being affected by the operating resistance caused by the gear train 30 and the inertial force of the flywheel 43. The clutch mechanism 35 uses a one-way clutch. With the clutch mechanism 35 of a simple structure, an appropriate established time t is ensured, and the trigger 12 quickly returns to the non-trigger position.

[0096] According to the illustrated timer mechanism 20, the gear train 30 is supported by a single gear train base 25. Therefore, the four-stage gear train 30 and the flywheel 43 are assembled on the gear train base 25 with stable precision. Thereby, the rotational movement of the flywheel 43 is stabilized, and a highly accurate and stable established time t is ensured.

[0097] On the shielding wall portion 17a that shields the contact limiting member 23 from the side, there is a window portion 17d for visually observing the contact limiting member 23 from the side (outside the starting device 10). By confirming the presence of the contact limiting member 23 via the window portion 17d, the operating state of the timer mechanism 20 can be quickly confirmed. In addition, by visually observing the operating state of the contact limiting member 23 via the window portion 17d, the dust-proof state inside the closed mechanism housing 21 (no malfunction caused by the mixing of foreign matters, etc.) can be indirectly confirmed.

[0098] Various changes can be made to the embodiments described above. For example, in the timer mechanism 20, a four-stage speed increasing gear train 30 is illustrated, but it can also be changed to a one-stage to three-stage or five-stage or more speed increasing gear train.

[0099] Regarding the support structure of the flywheel 43, a structure in which the first end 46a and the second end 46b of the support shaft 46 are tapered is illustrated, but a structure in which it is supported by the first support wall and the second support wall via bearings such as sliding bearings or rolling bearings can also be adopted.

[0100] As the driving tool 1, a pneumatic nail gun is illustrated, but it can also be similarly applied to other types of driving tools such as an electric nail gun equipped with a contact arm for preventing misoperation.

Claims

1. A driving tool, wherein, the driving tool includes: a tool main body that performs a driving action on the condition that both the movement of the trigger to the trigger triggering position and the movement of the contact arm to the arm triggering position are executed; and a timer mechanism that starts operating when the contact arm remains in the arm non-triggering position and the trigger moves to the trigger triggering position, the timer mechanism has: a flywheel that rotates due to the movement of the trigger to the trigger triggering position; a contact restricting member that can move between an unlocking position that allows the contact arm to move to the arm triggering position and a locking position that restricts the contact arm from moving to the arm triggering position, a predetermined time required for the movement action of the contact restricting member from the unlocking position to the locking position caused by the movement of the trigger to the trigger triggering position is defined by the inertial force generated by the rotation of the flywheel.

2. The driving tool according to claim 1, wherein, the driving tool has a supporting member that supports the flywheel so as to be rotatable, the flywheel has a supporting shaft whose both end portions are supported by the supporting member, at least one of the both end portions of the supporting shaft is conical with a diameter decreasing toward the supporting member.

3. The driving tool according to claim 2, wherein, the supporting member has a first supporting wall that supports the first end of the supporting shaft of the flywheel so as to be rotatable, a second supporting wall that supports the second end of the supporting shaft so as to be rotatable, and a connecting portion that elastically connects the first supporting wall and the second supporting wall, and the first supporting wall elastically abuts against the first end of the supporting shaft by the elastic force of the connecting portion, and the second supporting wall elastically abuts against the second end of the supporting shaft by the elastic force of the connecting portion.

4. The driving tool according to any one of claims 1 to 3, wherein, the timer mechanism has a multi-stage gear train that increases the rotational speed of the rotational action that is forced and performed due to the movement of the trigger to the trigger triggering position and transmits it to the flywheel.

5. The driving tool according to claim 4, wherein, the driving tool includes: a mechanism housing that encloses and houses the flywheel and the gear train; and a sealing member that seals between the supporting portion of the contact restricting member that extends and protrudes from the mechanism housing and the mechanism housing.

6. The driving tool according to claim 4, wherein, at least two gears in the gear train are coaxially arranged.

7. The driving tool according to claim 4, wherein, the driving tool has a clutch mechanism that is provided in the power transmission path of the gear train.

8. The driving tool according to claim 7, wherein, the clutch mechanism is a one-way clutch.

9. The driving tool according to claim 4, wherein, the driving tool has a gear train base that supports the gear train and is composed of a single component.

10. The driving tool according to claim 5, wherein, The mechanism housing has a shielding wall portion that shields the contact limiting member from the side, and a window portion for visually observing the contact limiting member from the side is provided in the shielding wall portion.

Images