Insertion tool

Abstract

The present invention provides a driving tool. A gas spring driving tool that uses the gas pressure of a pressure storage chamber as a thrust for driving has a drive return mechanism that causes a wheel portion to engage with a rack of a driver and moves an impact piston upward. When the impact piston starts to move downward from the top dead center, a large friction force is applied to the final engaging portion of the wheel portion through the rack. Therefore, it is necessary to improve the wear resistance of the final engaging portion of the wheel portion. When the impact piston (4) moves upward (D) and downward (B) relative to the top dead center, the second engaging portion (33a) that engages with the second rack (13) of the driver (11) is used as a special engaging portion for large friction force. Only the high strength and wear resistance of the second engaging portion (33a) of the second wheel portion (33) are ensured. Accordingly, compared with the case where the wheel mechanism including the first engaging portion (32a) of the first wheel portion (32) is made stronger or more wear-resistant as a whole, it is possible to achieve low cost and improve the maintainability during replacement.

Description

Technical Field

[0001] The present invention relates to a driving tool for driving a driving member such as a nail or a staple into wood or the like. Background Art

[0002] For example, known driving tools include gas spring type and spring type. The gas spring type driving tool disclosed in Patent Document 1 has a driver, a rack and a wheel, wherein the driver impacts the driven part; the rack and the wheel are used to move the driver upward. The rack is provided on the driver, and the driver and the piston are formed as a whole. The wheel rotates to cause the rack, the driver and the piston to retreat, thereby increasing the pressure of the gas in the pressure storage chamber connected to the cylinder. Using the pressure of the gas stored in the pressure storage chamber, the piston and the driver move forward to cause the driver to impact the driven part.

[0003] The wheel portion has a plurality of engaging portions, rollers adjacent to the engaging portions, and a non-engaging circumferential region without an engaging portion in the circumferential direction. When the driver is moved upward, the plurality of engaging portions are engaged with the rack in sequence, and finally the roller engages with the rack. The wheel portion further rotates, and the roller disengages from the rack. Through the non-engaging circumferential region, the wheel portion allows the rack and the driver to move downward. By using the roller, the wheel portion is freed from the rack through less friction. Accordingly, the driver moves smoothly downward through the gas stored in the pressure storage chamber.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Publication No. 6260944 Summary of the invention

[0007] [Technical problem to be solved by the invention]

[0008] However, the force acting on the final engaging part or the roller equivalent to the final engaging part that engages with the rack is larger than that of other engaging parts. For example, when the driver and the rack are moved upward together by the wheel portion, the pressure of the gas in the pressure storage chamber rises. Therefore, the force acting on the final engaging part or the roller equivalent to the final engaging part is larger than that of other engaging parts. Similarly, in the case of a spring type, when the driver and the rack are moved upward together by the wheel portion, the elastic potential energy accumulated by the spring for applying impact force to the driver increases. Moreover, just before disengaging from the rack, only one final engaging part or the roller engages with the rack, and is acted upon by a larger force. Therefore, sometimes the wear of the final engaging part is greater than that of other engaging parts. Therefore, a mechanism in which the final engaging part is not easily worn is required.

[0009] [Technical solutions for solving technical problems]

[0010] According to one feature of the present disclosure, the driving tool has a driver, which is arranged on the housing in a manner that can move up and down, and impacts the driven part by moving downward. There is a driving mechanism, which accumulates driving energy by moving the driver upward. The driver is provided with a first rack and a second rack to enable the driver to move upward. The first wheel portion is engaged with the first rack. The second wheel portion is engaged with the second rack. The first wheel portion has a first engaging circumferential area and a first non-engaging circumferential area, wherein the first engaging circumferential area has a plurality of first engaging portions engaged with the first rack; the first non-engaging circumferential area does not have a first engaging portion and allows the first rack to move downward. The second wheel portion has a second engaging portion engaged with the second rack. The second engaging portion is arranged on the second wheel portion in such a manner as to engage with the second rack in two stages, namely an initial stage of upward movement of the driver and a final stage of upward movement of the driver, wherein, in the initial stage of upward movement of the driver, the second engaging portion engages with the second rack at the same time as or before the first engaging portion of the first wheel portion begins to engage with the first rack; and in the final stage of upward movement of the driver, the second engaging portion disengages from the second rack at the same time as or after the first engaging portion of the first wheel portion disengages from the first rack.

[0011] Therefore, by the rotation of the first wheel portion and the second wheel portion, the driver returns to the upper position. In the initial stage of upward movement of the driver when the first engaging portion of the first wheel portion begins to engage with the first rack, the second engaging portion of the second wheel portion engages with the second rack. In the initial stage of upward movement, the second engaging portion engages with the second rack at the same time or before the first engaging portion of the first wheel portion engages with the first rack. In the stage (the final stage of upward movement of the driver) when the driver returns to the upper dead center (top dead center), the second engaging portion of the second wheel portion engages with the second rack. The second engaging portion of the second wheel portion engages with the second rack according to the two stages of the initial stage of upward movement and the final stage of upward movement. After the driver reaches the upper dead center (top dead center), the second wheel portion rotates, and accordingly, the engaging state of the second engaging portion relative to the second rack is released. In the final stage of the upward movement of the driver, the second engaging portion is disengaged from the second rack at the same time or thereafter when the first engaging portion of the first wheel is disengaged from the first rack. Therefore, the driver impacts the driven part by moving the driving mechanism downward. The second engaging portion of the second wheel is required to have higher durability and wear resistance. Accordingly, compared with the situation of ensuring the overall high strength of the first engaging portion of the first wheel, low cost can be achieved. In addition, in the case of aggravated wear, only the second wheel or only the second engaging portion of the second wheel can be replaced, and the first wheel can be directly continued to be used, so the maintenance cost can be reduced. Moreover, the second engaging portion of the second wheel acts as a common engaging portion, and the common engaging portion has the functions of both the engaging portion at the beginning of the engagement relative to the second rack and the engaging portion when the engagement is released. This can also achieve low cost.

[0012] According to other features of the present disclosure, the first wheel portion is disposed on one side of the driver, and the second wheel portion is disposed on the other side. Therefore, the driver is engaged from both sides by the first wheel portion and the second wheel portion. Accordingly, the driver can be suppressed from being displaced to one side during the upward movement.

[0013] According to another feature of the present disclosure, the first wheel portion and the second wheel portion are arranged on one side of the driver. Therefore, the driving protrusion can be made compact.

[0014] According to another feature of the present disclosure, the second engagement portion of the second wheel portion has a roller body structure that rolls relative to the second rack. Therefore, the wear resistance of the common engagement portion is improved.

[0015] According to another feature of the present disclosure, the rotation speed ratio between the first wheel portion and the second wheel portion is set to an integer ratio. Therefore, the positive motion mechanism can be realized with a simple structure.

[0016] According to another feature of the present disclosure, the rotation speed of the second wheel portion is faster than that of the first wheel portion. Therefore, the second wheel portion can be made compact while ensuring a cooperative relationship with the first wheel portion.

[0017] According to other features of the present disclosure, the second engaging portion of the second wheel portion has a higher strength than the first engaging portion of the first wheel portion. Therefore, the strength (durability, wear resistance) of the first engaging portion of the first wheel portion can be reduced compared to the second engaging portion of the second wheel portion. This can achieve low cost.

[0018] According to other features of the present disclosure, in the final stage of upward movement, the strength of the engaging teeth of the second rack is higher than that of the engaging teeth of the first rack, wherein the engaging teeth of the second rack engage with the second engaging portion of the second wheel portion, and the engaging teeth of the first rack engage with the first engaging portion of the first wheel portion. Therefore, by improving the strength of only the required parts, the overall cost reduction can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a longitudinal sectional view of the driving tool according to the first embodiment. This figure shows the state during driving.

[0020] Figure 2 yes Figure 1 The sectional view along the line II-II is a cross-sectional view of the reduction gear portion.

[0021] Figure 3 yes Figure 1 The sectional view along arrow III-III is a cross-sectional view of the drive return mechanism.

[0022] Figure 4 yes Figure 2 The cross-sectional view taken along the line IV-IV is a longitudinal cross-sectional view of the driving portion.

[0023] Figure 5 It is a perspective view of the drive return mechanism according to the first embodiment.

[0024] Figure 6 It is a perspective view of the actuator according to the first embodiment.

[0025] Figure 7 These are diagrams showing operations (A) to (E) of the drive return mechanism according to the first embodiment.

[0026] Figure 8 It is a longitudinal sectional view of the driving tool according to the second embodiment.

[0027] Fig. 9 yes Figure 8 The sectional view along the line IX-IX is a cross-sectional view of the reduction gear portion.

[0028] Fig.10 yes Figure 8 The sectional view in the direction of XX is the cross-sectional view of the drive return mechanism.

[0029] Fig.11 These are diagrams showing operations (F) to (K) of the drive return mechanism according to the second embodiment.

[0030] Fig.12 It is a longitudinal sectional view of the driving tool according to the third embodiment.

[0031] Fig.13 yes Fig.12 The sectional view taken along the line XIII-XIII is a cross-sectional view of the reduction gear portion.

[0032] Fig.14 yes Fig.12 The sectional view taken along the line XIV-XIV is a cross-sectional view of the reduction gear portion.

[0033] Fig.15 yes Fig.12 The sectional view along the line XV-XV is a cross-sectional view of the first wheel side of the drive return mechanism.

[0034] Fig.16 yes Fig.12 The sectional view along the line XVI-XVI is a cross-sectional view of the second wheel side of the drive return mechanism.

[0035] Fig.17 It is a perspective view of a drive return mechanism according to a third embodiment.

[0036] Fig.18 It is a perspective view of the actuator involved in the third embodiment.

[0037] Description of Reference Numerals

[0038] n: driving part; 1: driving tool; 2: main body shell; 3: cylinder; 3a: pressure storage chamber; 3b: shock absorber; 4: impact piston; 5: driving protrusion; 5a: driving channel, 5b: ejection port; 6: nail magazine; 7: handle; 8: switch operating handle; 9: battery pack; 10: tool body; 11: driver; 12: first rack; 12a: engaging teeth; 13: second rack; 13a: engaging teeth (lower side), 13b: engaging teeth (upper side) side); 20: driving return mechanism; 21: electric motor; 21a: motor housing; 22: reduction gear set; 22a: gear housing; 23: linkage gear set; 24: first linkage gear; 25: second linkage gear; 30: wheel mechanism (first embodiment); 31: wheel mechanism housing; 32: first wheel portion; 32a: first engaging portion; 33: second wheel portion; 33a: second engaging portion; 34: driving shaft; 34a: bearing; 35: Driven shaft; 35a: bearing; 40: wheel mechanism (second embodiment); 41: first wheel portion; 41a: first engaging portion; 42: second wheel portion; 42a: second engaging portion; 43: linkage gear set; 44: drive shaft; 45: driven shaft; 46: first linkage gear; 47: second linkage gear; 48: wheel mechanism housing; 50: wheel mechanism (third embodiment); 51: wheel mechanism housing; 52: drive shaft; 53: first driven shaft; 54: the second driven shaft; 52a, 53a, 54a: bearings; 55: the first wheel portion; 55a: the first engaging portion; 56: the first linkage gear; 57: the second linkage gear; 58: the third linkage gear; 59: the fourth linkage gear; 60: the second wheel portion; 60a: the second engaging portion; 61: driver; 62: the first rack; 62a: the engaging teeth; 63: the second rack; 63a: the engaging teeth (lower side), 63b: the engaging teeth (upper side). DETAILED DESCRIPTION

[0039] Next, according to Figures 1 to 18 The driving tool 1 according to the first to third embodiments of the present disclosure will be described. In the first to third embodiments described below, a gas spring type driving tool is exemplified as the driving tool 1, and the gas spring type driving tool uses the gas pressure of the gas sealed in the pressure storage chamber 3a as the thrust for driving the driving part n. Figure 1 to Figure 4 The driving tool 1 according to the first embodiment is shown. In the following description, the driving direction of the driving part n is referred to as the lower side, and the direction opposite to the driving direction is referred to as the upper side. The driver 11 described below moves downward to drive the driving part n, and after the driving, the driver 11 returns to the upper side. Figure 1 The direction perpendicular to the paper surface is regarded as the width direction of the driving tool 1.

[0040] The driving tool 1 of the first embodiment has a tool body 10, in which a cylinder 3 is installed in a cylindrical main body shell 2. The impact piston 4 is supported in the cylinder 3 in a manner that allows it to reciprocate up and down. A driver 11 for impacting the driving piece n is provided at the center of the lower surface of the impact piston 4. The impact piston 4 and the driver 11 are provided so as to be able to move up and down in the cylinder 3 as a whole. The driver 11 extends downwardly for a long distance. The top end side of the driver 11 enters into the driving channel 5a of the driving protrusion 5 provided on the lower surface side of the tool body 10. The lower end of the driving protrusion 5 becomes an ejection port 5b through which the driving piece n is ejected. Figure 1 to Figure 3 , the state at the stage where the impact piston 4 reaches the lower moving end and the driven part n is ejected from the ejection port 5b is shown. Figures 1 to 3 FIG. 5 shows a state in which the driver 11 moves downward in the driving channel 5a and the top end thereof slightly protrudes from the ejection port 5b.

[0041] A nail magazine 6 loaded with a plurality of driving tools n is combined with the driving protrusion 5. A handle portion 7 for the user to hold is provided on the side of the main body shell 2. A switch operating handle 8 for pressing and operating with the fingertips of the holding hand is provided at the base of the handle portion 7. A battery pack 9 is installed at the top of the handle portion 7 as a power source. The battery pack 9 can be removed for charging and can be used as a power source for other power tools. The main body shell 2, the handle portion 7, the switch operating handle 8, and the battery pack 9 are only Figure 1 It is shown in Figure 2 Illustration will be omitted below.

[0042] The driving protrusion 5 has a driving return mechanism 20 for returning the impact piston 4 and the driver 11 upward as a whole. The impact piston 4 is returned upward by the driving return mechanism 20, thereby increasing the air pressure of the pressure storage chamber 3a on the upper surface side of the impact piston 4. Due to the increased air pressure in the pressure storage chamber 3a, the impact piston 4 moves downward and the driver 11 impacts the driving member n. The structure (driving return mechanism 20) for accumulating driving energy (thrust of the pressure storage chamber 3a) by the upward movement of the driver 11 constitutes the driving mechanism of the driving tool 1. A shock absorber 3b for absorbing the impact at the lower moving end of the impact piston 4 is arranged at the lower part of the cylinder 3.

[0043] The drive return mechanism 20 has an electric motor 21, a reduction gear set 22 and a wheel mechanism 30. The electric motor 21 is started with the electric power of the battery pack 9 as a power source. The electric motor 21 is started by depressing the operating switch operating handle 8. The rotation output of the electric motor 21 is reduced by two groups of reduction gear sets 22 composed of planetary gear trains and output to the wheel mechanism 30. The electric motor 21 is accommodated in a cylindrical motor housing 21a. The reduction gear set 22 is accommodated in a gear housing 22a of the same cylindrical shape. The motor housing 21a is coaxially coupled to the end of the gear housing 22a.

[0044] The wheel mechanism 30 has a wheel mechanism housing 31. Figure 2 As shown, the wheel mechanism housing 31 has a cross-sectional shape of 8 formed by connecting two large and small cylinders. The wheel mechanism housing 31 is integrally provided on the driven protrusion 5. The gear housing 22a is combined with the wheel mechanism housing 31. The details of the wheel mechanism 30 are shown in Figure 5 In Figure 5 The wheel mechanism housing 31 is omitted. The wheel mechanism 30 has a first wheel portion 32, a second wheel portion 33 and a linkage gear set 23 in addition to the wheel mechanism housing 31. The first wheel portion 32, the second wheel portion 33 and the linkage gear set 23 are accommodated in the wheel mechanism housing 31. The drive shaft 34 of the wheel mechanism 30 is combined with the reduction gear set 22.

[0045] like Figure 1 , Figure 4 As shown, the drive shaft 34 is rotatably supported on the wheel mechanism housing 31 through two bearings 34a. The second wheel portion 33 and the second interlocking gear 25 are integrally provided on the drive shaft 34. A driven shaft 35 is provided on the wheel mechanism housing 31 in parallel with the drive shaft 34. The driven shaft 35 is rotatably supported on the wheel mechanism housing 31 through two bearings 35a. The first wheel portion 32 and the first interlocking gear 24 are integrally provided on the driven shaft 35.

[0046] like Figure 3 , Figure 4 As shown, the driving shaft 34 and the driven shaft 35 are arranged at a certain distance on one side and the other side in the width direction of the driver 11. Figure 3 , Figure 4 The first wheel portion 32 and the first interlocking gear 24 are arranged on the right side in the width direction of the driver 11. Figure 3 , Figure 4 The second wheel portion 33 and the second interlocking gear 25 are configured on the left side of the wheel portion 33.

[0047] The second interlocking gear 25 on the driving shaft 34 and the first interlocking gear 24 on the driven shaft 35 are respectively spur gears and mesh with each other. The gear ratio of the first interlocking gear 24 and the second interlocking gear 25 is set to 2:1. Therefore, the rotation of the driving shaft 34 is reduced to 1 / 2 and transmitted to the driven shaft 35. Therefore, the driving shaft 34 rotates 2 times and the driven shaft 35 rotates 1 time.

[0048] The rotation speed ratio of the driving shaft 34 and the driven shaft 35 is set to 2:1, and accordingly, the rotation speed ratio of the first wheel portion 32 and the second wheel portion 33 is set to 1:2. Therefore, when the second wheel portion 33 rotates once, the first wheel portion 32 rotates 1 / 2 of a circle.

[0049] like Figure 3 As shown, there are a total of 8 first engaging parts 32a on the first wheel portion 32. Each first engaging part 32a has a cylindrical shape and is supported at both ends. The 8 first engaging parts 32a are arranged at equal intervals along the same circumference. The 8 first engaging parts 32a are arranged within a range of approximately half a circle around the axis. The circumferential range in which the 8 first engaging parts 32a are provided is equivalent to the first engaging circumferential region. The remaining approximately half a circle in which the first engaging parts 32a are not arranged is equivalent to the first non-engaging circumferential region. When the driver 11 moves downward, the first non-engaging circumferential region faces the engaging teeth 12a of the first rack 12. Accordingly, since the first engaging part 32a of the first wheel portion 32 does not interfere with the engaging teeth 12a of the first rack 12 when the driver 11 moves downward, the driver 11 can move downward smoothly. Accordingly, the thrust of the impact piston 4 can be maintained.

[0050] The second wheel portion 33 has a second engaging portion 33a. The second engaging portion 33a has a cylindrical shape and is supported at both ends. This second engaging portion 33a is equivalent to a common engaging portion that makes the engaging portion at the beginning of upward movement and the engaging portion when the upward movement is released common. The second engaging portion 33a of the second wheel portion 33 has a roller body structure, and the roller body structure supports the roller in a freely rotatable manner through the shaft. In the circumferential area of ​​the second wheel portion 33, a certain range on the circumference of the second engaging portion 33a is configured to be equivalent to the second engaging circumferential area. When the driver 11 moves upward, the second engaging circumferential area is opposite to the second rack 13. The remaining range on the circumference without the second engaging portion 33a is equivalent to the second non-engaging circumferential area. When the driver 11 moves downward, the second non-engaging circumferential area is opposite to the second rack 13. Accordingly, when the driver 11 moves downward, the second engaging portion 33 a of the second wheel portion 33 does not interfere with the engaging teeth 13 a and 13 b of the second rack 13 , and therefore the driver 11 can move downward smoothly.

[0051] like Figure 3 , Figure 5 , Figure 6 As shown in FIG. 1 , the driver 11 is provided with a first rack 12 for meshing with the first wheel portion 32 and a second rack 13 for meshing with the second wheel portion 33. The first rack 12 is provided along a side surface (a side where the first wheel portion 32 is arranged) on one side in the width direction of the driver 11. The first rack 12 has a plurality of ( Figure 3 , Figure 6 The second rack 13 is provided along the side surface of the other side in the width direction of the driver 11 (the side where the second wheel portion 33 is arranged). Figure 3 As shown, the second rack 13 has two engaging teeth 13a and 13b.

[0052] The engaging teeth 13a and 13b of the second rack 13 have improved strength and wear resistance compared to the engaging teeth 12a of the first rack 12. For example, the engaging teeth 13a and 13b can be locally heat treated or surface treated to improve their strength and wear resistance.

[0053] like Figure 6 As shown, the engaging teeth 13a at the lower side of the second rack 13 are arranged at a position offset downward from the engaging teeth 12a at the lowermost portion of the first rack 12. The engaging teeth 13b at the upper side of the second rack 13 are arranged at a position offset upward from the engaging teeth 12a at the uppermost portion of the first rack 12. By the rotation of the first wheel portion 32 and the second wheel portion 33, the meshing positions of the first wheel portion 32 and the second wheel portion 33 relative to the first rack 12 and the second rack 13 are changed, and thus the driver 11 returns upward.

[0054] exist Figure 7 FIG. 4 shows a state where the driver 11 and the impact piston 4 are returned upward by the action of the drive return mechanism 20. Figure 7 In the standby state (initial state) shown in (A), the impact piston 4 is located slightly below the top dead center. The first engaging portion 32a at the rear end of the first engaging circumferential region of the first wheel portion 32 engages with the lowest engaging tooth 12a of the first rack 12 of the driver 11 from the bottom. In addition, the second engaging portion 33a of the second wheel portion 33 engages with the engaging tooth 13a at the lower side of the second rack 13 at the bottom. The first wheel portion 32 and the second wheel portion 33 are respectively engaged with both the first rack 12 and the second rack 13 at the same time.

[0055] In this standby state, when the switch operating handle 8 is pulled, the driving return mechanism 20 starts to operate. When the switch operating handle 8 is pulled to start the electric motor 21, as shown by the arrow in the figure, the second wheel portion 33 rotates in the clockwise direction. In addition, the first wheel portion 32 rotates in the counterclockwise direction through the interlocking gear set 23. The first wheel portion 32 rotates in the opposite direction at half the rotational angular velocity of the second wheel portion 33.

[0056] The first wheel 32 rotates counterclockwise to disengage the first engaging portion 32a from the engaging tooth 12a at the bottom of the first rack 12. As a result, the second wheel 33 rotates clockwise to engage the second engaging portion 33a with the engaging tooth 13a at the bottom of the second rack 13, and the driver 11 and the impact piston 4 move upward. Figure 7 As shown in (B), the impact piston 4 returns to the top dead center. (B) shows the state just before driving (the final stage of the upward movement of the driver 11). In this stage, one driving piece n is supplied from the nail magazine 6 into the driving channel 5a.

[0057] When the impact piston 4 reaches the top dead center, the air pressure in the pressure storage chamber 3a is sufficiently high. Therefore, in this state just before the impact, a large load (thrust of the pressure storage chamber 3a and rotational power of the second wheel 33) is applied to the second engagement portion 33a of the second wheel 33 through the engagement teeth 13a on the lower side of the second rack 13.

[0058] When the impact piston 4 reaches the top dead center, the second wheel portion 33 further rotates clockwise from the position immediately before the impact as shown in (B), thereby disengaging the second engaging portion 33a from the engaging teeth 13a of the second rack 13. As a result, the return action of the driver 11 (engaged state of the second engaging portion 33a) performed by the drive return mechanism 20 is released. At this stage, a large friction force is generated on the second engaging portion 33a. By disengaging the second engaging portion 33a from the engaging teeth 13a of the second rack 13, as shown in FIG. Figure 7 As shown in (C), the impact piston 4 moves downward using the air pressure of the pressure storage chamber 3a as a thrust. As the impact piston 4 moves downward, the driver 11 moves downward in the driving channel 5a. While the driver 11 is moving downward, a driven part n supplied to the driving channel 5a is impacted by the top end of the driver 11. As a result, the driven part n is driven into the driven part W from the ejection port 5b.

[0059] During the downward movement of the impact piston 4, the electric motor 21 is kept in the started state. Therefore, in the drive return mechanism 20, the first wheel portion 32 and the second wheel portion 33 rotate in opposite directions. In the stage of the downward movement of the driver 11, the non-engaging circumferential area of ​​the first wheel portion 32 (the range of approximately half of the circumference where the first engaging portion 32a does not exist) faces the side of the driver 11, and the non-engaging circumferential area of ​​the second wheel portion 33 (the peripheral portion where the second engaging portion 33a does not exist) faces the side of the driver 11. Accordingly, the first engaging portion 32a of the first wheel portion 32 and the second engaging portion 33a of the second wheel portion 33 can be prevented from interfering with the driver 11. Accordingly, the driver 11 is allowed to move downward smoothly.

[0060] While the first wheel portion 32 and the second wheel portion 33 continue to rotate, the impact piston 4 reaches the lower moving end, and the driving action is completed. Figure 7In the driving completion stage shown in (C), the second engaging portion 33a of the second wheel portion 33 is again meshed with the lower side of the engaging teeth 13b on the upper side of the second rack 13. In this way, the second engaging portion 33a of the second wheel portion 33 is disengaged from the engaging teeth 13a on the lower side of the second rack 13, and the impact piston 4 starts to move downward. Thereafter, when the impact piston 4 reaches the lower moving end, the second engaging portion 33a is again engaged with the engaging teeth 13b on the upper side of the second rack 13 from the lower side. Accordingly, the second engaging portion 33a of the second wheel portion 33 functions as a disengaging portion that allows the impact piston 4 to move downward, and functions as a starting engaging portion for starting the upward movement of the driver 11. In addition, the second engaging portion 33a functions as a common engaging portion that has both the functions of an engaging portion at the start of engagement with the second rack 13 and a disengaging portion.

[0061] At the stage (C) when the impact piston 4 reaches the lower moving end, the electric motor 21 is kept in the started state and the driving return mechanism 20 is kept in the action. Figure 7 In the return start stage (initial stage of upward movement of the driver 11) shown in (D), the second wheel portion 33 rotates clockwise in a state where the second engaging portion 33a is engaged from the lower side with the engaging teeth 13b on the upper side of the second rack 13. Accordingly, the driver 11 starts to move upward. In addition, the first wheel portion 32 rotates counterclockwise, and the first engaging portion 32a on the front side of the engaging circumferential region is engaged with the lower side of the engaging teeth 12a of the first rack 12.

[0062] like Figure 7 As shown in (E), the first wheel portion 32 rotates counterclockwise and the second wheel portion 33 rotates clockwise, thereby completing the transition from the engaging state in which the second engaging portion 33a is engaged with the second rack 13 to the engaging state in which the first engaging portion 32a is engaged with the first rack 12.

[0063] After the transition to the engagement state shown in (E), the driver 11 moves upwards through the engagement state in which the first engagement portion 32a of the first wheel portion 32 is engaged with the engagement tooth 12a of the first rack 12, and the impact piston 4 returns to the standby position shown in (A). In conjunction with the counterclockwise rotation of the first wheel portion 32, the second wheel portion 33 rotates clockwise. Accordingly, the second engagement portion 33a of the second wheel portion 33 is again engaged with the lower side of the engagement tooth 13a on the lower side of the second rack 13.

[0064] When the impact piston 4 returns to the standby position shown in (A), the electric motor 21 automatically stops and the driving action is completed. In this standby state, if the operating switch operating handle 8 is pressed again, the driving return mechanism 20 starts to operate, and a series of actions are performed in the order of standby state (A) → driving start (B) → driving completion (C) → return start (D) → wheel transition (E).

[0065] According to the driving tool 1 of the first embodiment described above, the driver 11 returns upward by the rotation of the first wheel portion 32 and the second wheel portion 33. At the stage when the impact piston 4 returns to the upper dead center, the second engaging portion 33a (disengaging portion) of the second wheel portion 33 engages with the second rack 13. After the impact piston 4 reaches the upper dead center, the second wheel portion 33 rotates further, whereby the engaging state of the second engaging portion 33a relative to the second rack 13 is released. Accordingly, the driver 11 moves downward through the driving mechanism (thrust of the pressure storage chamber 3a) to impact the driving member n. In this way, the second engaging portion 33a of the second wheel portion 33, which acts as the engaging portion when the engaging state relative to the second rack 13 is released, is required to have high durability and wear resistance.

[0066] In addition, the second engaging portion 33a of the second wheel portion 33 also has the function of serving as a starting engaging portion, which moves the driver 11 upward when the impact piston 4 returns to the standby position (at the start of return (D)). A relatively large load or friction force is also applied to the second engaging portion 33a at this stage. In this way, by causing a large load or friction force to act on the second engaging portion 33a of the second wheel portion 33 at the start of engagement and when the engagement is released, the load acting on each first engaging portion 32a of the first wheel portion 32 can be reduced. Accordingly, by ensuring the required strength and wear resistance of the second engaging portion 33a of the second wheel portion 33, low cost can be achieved compared to the case where high strength and wear resistance of the entirety including the first wheel portion 32 are ensured. In addition, in the case of increased wear, since only the second engaging portion 33a of the second wheel portion 33 needs to be replaced, and the first wheel portion 32 can continue to be used directly, the maintenance cost can be reduced.

[0067] In addition, according to the first embodiment, the first wheel portion 32 is arranged on one side in the width direction of the driver 11, and the second wheel portion 33 is arranged on the other side in the width direction. Accordingly, since the driver 11 is engaged from both sides in the width direction by the first wheel portion 32 and the second wheel portion 33, it is possible to suppress the driver 11 from being displaced to one side in the width direction during the upward movement action.

[0068] Furthermore, the second engaging portion 33a of the second wheel portion 33 functions as a common engaging portion having both the functions of the engaging start portion and the engaging release portion. This allows for a simplified structure. The second engaging portion 33a uses a roller body structure that supports the roller rotatably via the shaft portion. This further improves the wear resistance of the second engaging portion 33a.

[0069] According to the first embodiment, the rotation speed ratio of the first wheel portion 32 and the second wheel portion 33 is set to 1:2 (integer ratio). Accordingly, the drive return mechanism 20 can be made into a mechanism with high positive motion by a simple structure. In particular, the rotation speed of the second wheel portion 33 is set to twice the rotation speed of the first wheel portion 32. Therefore, the compactness (reduced diameter) of the second wheel portion 33 can be achieved while ensuring the synergistic relationship with the first wheel portion 32.

[0070] In addition, the engagement teeth 13a, 13b of the second rack 13 engaged with the second engagement portion 33a of the second wheel portion 33 are stronger than the engagement teeth 12a of the first rack 12 engaged with the first engagement portion 32a of the first wheel portion 32. Thus, by improving the strength of only the required parts, the overall cost reduction can be achieved.

[0071] Various changes can be made to the above-described embodiments. For example, in the first embodiment, a structure is exemplified in which the speed ratio of the first wheel portion 32 and the second wheel portion 33 is set to 1:2 by the linkage gear set 23. The speed ratio of the first wheel portion 32 and the second wheel portion 33 can be changed within the range of an integer ratio. For example, in Figure 8 to Figure 11 , a driving tool 1 according to a second embodiment is shown, in which the rotation speed ratio of the first wheel portion 41 and the second wheel portion 42 is set to 1:3. The wheel mechanism 40 of the driving return mechanism 20 of the driving tool 1 according to the second embodiment is different from that of the first embodiment. The same reference numerals are used for other components and structures that do not need to be changed, and their descriptions are omitted.

[0072] The drive return mechanism 20 involved in the second embodiment includes: an electric motor 21, which uses the electric power of the battery pack 9 as a power source; and a reduction gear group 22, which reduces the rotation output of the electric motor 21. This is the same as the first embodiment. The output of the reduction gear group 22 is input to the drive shaft 44 of the wheel mechanism 40. The wheel mechanism 40 has a wheel mechanism housing 48 of substantially the same shape as the first embodiment. The first wheel portion 41, the second wheel portion 42 and the interlocking gear group 43 are accommodated in the wheel mechanism housing 48. The first wheel portion 41 and the second wheel portion 42 are separately arranged on one side and the other side in the width direction of the driver 11. This is also the same as the first embodiment.

[0073] The interlocking gear set 43 includes a first interlocking gear 46 and a second interlocking gear 47, each of which is a spur gear. The second interlocking gear 47 is coupled to the drive shaft 44, and the first interlocking gear 46 is coupled to the driven shaft 45. The number of teeth of the first interlocking gear 46 on the driven side is set to three times the number of teeth of the second interlocking gear 47 on the driving side. Therefore, the rotation speed of the driven shaft 45 is set to 1 / 3 of the rotation speed of the drive shaft 44.

[0074] As in the first embodiment, the second wheel portion 42 is coupled to the drive shaft 44, and the first wheel portion 41 is coupled to the driven shaft 45. Therefore, the rotation speed of the first wheel portion 41 is set to 1 / 3 of the rotation speed of the second wheel portion 42. Therefore, during the period when the first wheel portion 41 rotates one circle, the second wheel portion 42 rotates three circles. As in the first embodiment, the drive shaft 44 and the driven shaft 45 are rotatably supported by the wheel mechanism housing 48 through bearings.

[0075] like Fig.10 As shown, the first wheel portion 41 has a total of 7 first engaging portions 41a. Each first engaging portion 41a has a cylindrical shape and is supported at both ends. The 7 first engaging portions 41a are arranged at equal intervals along the same circumference. The 7 first engaging portions 41a cover a range slightly wider than the range of approximately half a circumference around the axis, that is, they are arranged in a range slightly wider than the first wheel portion 32 of the first embodiment. Therefore, the 7 first engaging portions 41a are arranged at intervals larger than the 8 first engaging portions 32a involved in the first embodiment in the circumferential direction. The circumferential range in which the 7 first engaging portions 41a are provided is equivalent to the first engaging circumferential region. The remaining approximately half a circumferential range in which the first engaging portion 41a is not configured is equivalent to the first non-engaging circumferential region. In this way, relative to the 1st wheel portion 32 involved in the first embodiment having a total of 8 first engaging portions 32a, the 1st wheel portion 41 involved in the second embodiment has a total of 7 first engaging portions 41a.

[0076] Since the number and spacing of the first engaging portions 41a (the circumferential range of the first engaging circumferential region) are different from those in the first embodiment, the rotational speed ratio (1:3) between the first wheel portion 41 and the second wheel portion 42 is correspondingly different from the rotational speed ratio (1:2) of the first embodiment.

[0077] The second wheel portion 42 has a second engaging portion 42a. The second engaging portion 42a has a cylindrical shape and is supported at both ends. The second engaging portion 42a is equivalent to a common engaging portion that makes the starting engaging portion and the releasing engaging portion common. The second engaging portion 42a of the second wheel portion 42 has a roller body structure that supports the roller on the shaft portion in a freely rotatable manner. The second wheel portion 42 involved in the second embodiment has the same structure as the second wheel portion 33 involved in the first embodiment.

[0078] like Fig.10As shown, the driver 11 is provided with a first rack 12 for meshing with the first wheel portion 41 and a second rack 13 for meshing with the second wheel portion 42. The first rack 12 is provided along the side surface on one side of the driver 11 (the side on which the first wheel portion 41 is arranged). The first rack 12 involved in the second embodiment has a total of 7 engaging teeth 12a. This is different from the first embodiment in which the first rack 12 involved has a total of 8 engaging teeth 12a. The second rack 13 is provided along the side surface on the other side of the driver 11 (the side on which the second wheel portion 42 is arranged). As shown Fig.10 As shown, the second rack 13 has two engaging teeth 13a and 13b.

[0079] As in the first embodiment, the engaging teeth 13a and 13b of the second rack 13 have improved strength and wear resistance compared to the engaging teeth 12a of the first rack 12. For example, the engaging teeth 13a and 13b can be locally heat treated or surface treated to improve their strength and wear resistance.

[0080] like Fig.10 As shown, the engaging teeth 13a at the lower side of the second rack 13 are arranged at a position offset downward from the engaging teeth 12a at the lowermost portion of the first rack 12. The engaging teeth 13b at the upper side of the second rack 13 are arranged at a position offset upward from the engaging teeth 12a at the uppermost portion of the first rack 12. By the rotation of the first wheel portion 41 and the second wheel portion 42, the meshing positions of the first wheel portion 41 and the second wheel portion 42 relative to the first rack 12 and the second rack 13 change, thereby the driver 11 returns upward. This is also the same as the first embodiment.

[0081] exist Fig.11 2 shows a state where the driver 11 and the impact piston 4 are returned upward by the operation of the rack return mechanism 20 according to the second embodiment. Fig.11 In the standby state (initial state) shown in (F), the impact piston 4 is located slightly below the top dead center. The first engaging portion 41a at the rear end of the first engaging circumferential region of the first wheel portion 41 engages with the lowest engaging tooth 12a of the first rack 12 of the driver 11 from the bottom. In addition, the second engaging portion 42a of the second wheel portion 42 engages with the engaging tooth 13a at the lower side of the second rack 13 at the bottom. The first wheel portion 41 and the second wheel portion 42 are respectively engaged with both the first rack 12 and the second rack 13 at the same time.

[0082] In this standby state (F), when the switch operating handle 8 is pulled, the driving return mechanism 20 starts to operate. When the switch operating handle 8 is pulled to start the electric motor 21, as shown by the arrow in the figure, the second wheel 42 rotates in the clockwise direction. In addition, the first wheel 41 rotates in the counterclockwise direction through the interlocking gear set 43. The first wheel 41 rotates in the opposite direction at 1 / 3 of the rotation speed of the second wheel 42.

[0083] The first wheel 41 rotates counterclockwise to disengage the first engaging portion 41a from the engaging tooth 12a at the bottom of the first rack 12. As a result, the second wheel 42 rotates clockwise to engage the second engaging portion 42a with the engaging tooth 13a at the bottom of the second rack 13, and the driver 11 and the impact piston 4 move upward. Fig.11 As shown in (G), the impact piston 4 returns to the top dead center. (G) shows the state just before driving. In this stage, one driving piece n is supplied from the nail magazine 6 into the driving channel 5a.

[0084] When the impact piston 4 reaches the top dead center, the air pressure in the pressure storage chamber 3a is sufficiently high. Therefore, in this state just before the impact piston 4 is driven, a large load (thrust of the pressure storage chamber 3a and rotational power of the second wheel 42) is applied to the second engagement portion 42a of the second wheel 42 through the engagement teeth 13a on the lower side of the second rack 13.

[0085] When the impact piston 4 reaches the top dead center, the second wheel portion 42 further rotates clockwise from the position immediately before the impact as shown in (G), thereby disengaging the second engaging portion 42a from the engaging teeth 13a of the second rack 13. As a result, the return action of the driver 11 (engaged state of the second engaging portion 42a) performed by the drive return mechanism 20 is released. At this stage, a large friction force is generated on the second engaging portion 42a. By disengaging the second engaging portion 42a from the engaging teeth 13a of the second rack 13, as shown in FIG. Fig.11 As shown in (H), the impact piston 4 moves downward using the air pressure of the pressure storage chamber 3a as a thrust. As the impact piston 4 moves downward, the driver 11 moves downward in the driving channel 5a. While the driver 11 is moving downward, a driven part n supplied to the driving channel 5a is impacted by the top end of the driver 11. As a result, the driven part n is driven into the driven part W from the ejection port 5b.

[0086] During the downward movement of the impact piston 4, the electric motor 21 is kept in the started state. Therefore, in the drive return mechanism 20, the first wheel portion 41 and the second wheel portion 42 rotate in opposite directions. In the stage of the downward movement of the driver 11, the non-engaging circumferential area of ​​the first wheel portion 41 (the range where the first engaging portion 41a does not exist) faces the side of the driver 11, and the non-engaging circumferential area of ​​the second wheel portion 42 (the peripheral portion where the second engaging portion 42a does not exist) faces the side of the driver 11. Accordingly, the first engaging portion 41a of the first wheel portion 41 and the second engaging portion 42a of the second wheel portion 42 can be prevented from interfering with the driver 11. Accordingly, the driver 11 is allowed to move downward smoothly.

[0087] While the first wheel 41 and the second wheel 42 continue to rotate, the impact piston 4 reaches the lower moving end, and the driving action is completed. Fig.11 In the driving completion stage shown in (H), the second engaging portion 42a of the second wheel portion 42 is again engaged with the lower side of the engaging teeth 13b on the upper side of the second rack 13. In this way, the second engaging portion 42a of the second wheel portion 42 is disengaged from the engaging teeth 13a on the lower side of the second rack 13 and the impact piston 4 starts to move downward. Thereafter, at the stage when the impact piston 4 reaches the lower moving end, the second engaging portion 42a is again engaged with the engaging teeth 13b on the upper side of the second rack 13 from the lower side. Accordingly, the second engaging portion 42a of the second wheel portion 42 functions as a disengaging portion that allows the downward movement of the impact piston 4, and functions as a starting engaging portion for starting the upward movement of the driver 11. In addition, the second engaging portion 42a functions as a common engaging portion having both the functions of a disengaging portion and a starting engaging portion.

[0088] When the impact piston 4 reaches the lower moving end (H), the electric motor 21 is kept in the started state and the driving return mechanism 20 is kept in motion. Fig.11 In the return start stage shown in (I), the second wheel portion 42 rotates clockwise in a state where the second engaging portion 42a is engaged from the lower side with the engaging teeth 13b on the upper side of the second rack 13. Accordingly, the driver 11 starts to move upward. In addition, the first wheel portion 41 rotates counterclockwise, and the first engaging portion 41a on the front side of the engaging circumferential region is engaged with the lower side of the engaging teeth 12a of the first rack 12.

[0089] like Fig.11 As shown in (J), the first wheel portion 41 rotates counterclockwise and the second wheel portion 42 rotates clockwise, thereby completing the transition from the engaging state in which the second engaging portion 42a is engaged with the second rack 13 to the engaging state in which the first engaging portion 41a is engaged with the first rack 12.

[0090] After the transition to the engagement state shown in (J), the driver 11 moves upward by the engagement state in which the first engagement portion 41a of the first wheel portion 41 is engaged with the engagement teeth 12a of the first rack 12. Fig.11 The impact piston 4 returns to the standby position shown in (F) through the state shown in (K). The second wheel portion 42 rotates clockwise in conjunction with the counterclockwise rotation of the first wheel portion 41. As a result, the second engaging portion 42a of the second wheel portion 42 is again engaged with the lower side of the engaging tooth 13a on the lower side of the second rack 13.

[0091] When the impact piston 4 returns to the standby position shown in (F), the electric motor 21 automatically stops and the driving action is completed. In this standby state, if the operating switch operating handle 8 is pressed again, the driving return mechanism 20 starts to operate, and a series of actions are performed in the order of standby state (F) → driving start (G) → driving completion (H) → return start (I) → wheel transition (J) → impact piston return (K).

[0092] According to the driving tool 1 of the second embodiment described above, by applying a large load or friction force to the second engaging portion 42a of the second wheel portion 42 at the start of engagement and at the release of engagement with respect to the second rack 13, the load acting on each first engaging portion 41a of the first wheel portion 41 can be reduced. Accordingly, by ensuring the strength and wear resistance required for the second engaging portion 42a of the second wheel portion 42, cost reduction can be achieved compared to the case where high strength and wear resistance of the entirety including the first wheel portion 41 are ensured. In addition, in the case of increased wear, since only the second engaging portion 42a of the second wheel portion 42 needs to be replaced, and the first wheel portion 41 can continue to be used directly, the maintenance cost can be reduced.

[0093] In addition, according to the second embodiment, the rotation speed ratio of the first wheel portion 41 and the second wheel portion 42 is set to 1:3 (integer ratio). Accordingly, the second wheel portion 42 and the second interlocking gear 47 can be miniaturized (reduced in diameter) compared to the second wheel portion 33 and the second interlocking gear 25 involved in the first embodiment. Accordingly, the wheel mechanism 40 can be miniaturized compared to the wheel mechanism 30 involved in the first embodiment. Therefore, the driving tool 1 can be made compact mainly in the width direction.

[0094] Furthermore, in the second embodiment, the first wheel portion 41 is also arranged on one side in the width direction of the driver 11, and the second wheel portion 42 is arranged on the other side in the width direction. Accordingly, since the driver 11 is engaged from both sides in the width direction by the first wheel portion 41 and the second wheel portion 42, it is possible to suppress the driver 11 from being displaced to one side in the width direction during the upward movement.

[0095] Furthermore, the second engaging portion 42a of the second wheel portion 42 functions as a common engaging portion having both the functions of the engaging start portion and the engaging release portion, thereby simplifying the structure. The second engaging portion 42a uses a roller body structure, which supports the roller body in a rotatable manner through an axis member, thereby further improving its wear resistance.

[0096] Further changes can be made to the first and second embodiments described above. For example, in the first and second embodiments, a wheel dual-side configuration structure is adopted, that is, the first wheel portion 32, 41 is configured on one side in the width direction of the driver 11, and the second wheel portion 33, 42 is configured on the other side in the width direction. In contrast, the first wheel portion and the second wheel portion may be centrally configured on one side in the width direction of the driver 11.

[0097] exist Figures 12 to 18 1 shows a third embodiment of a driving tool 1 in which the wheel is arranged on one side. The third embodiment is different from the first and second embodiments in that the wheel mechanism 50 of the driving tool 1 is different. The same reference numerals are used for the same components and structures as those of the first and second embodiments, and their description is omitted.

[0098] The wheel mechanism 50 involved in the third embodiment has a wheel mechanism housing 51. The wheel mechanism housing 51 is combined with the driving protrusion 5. The drive shaft 52, the first driven shaft 53, and the second driven shaft 54 ​​are rotatably supported by the wheel mechanism housing 51 through bearings 52a, 53a, and 54a, respectively. The rotation output of the electric motor 21 is transmitted to the drive shaft 52 via the reduction gear group 22.

[0099] The first wheel portion 55 and the first interlocking gear 56 are coupled to the drive shaft 52. Fig.13 As shown in FIG. 1 , the first interlocking gear 56 is meshed with the second interlocking gear 57. The second interlocking gear 57 is coupled to the first driven shaft 53. Fig.13 , Fig.14 As shown, the second interlocking gear 57 and the third interlocking gear 58 are coupled to the first driven shaft 53. The fourth interlocking gear 59 is meshed with the third interlocking gear 58. The fourth interlocking gear 59 is coupled to the second driven shaft 54. The fourth interlocking gear 59 and the second wheel portion 60 are coupled to the second driven shaft 54.

[0100] Thus, in the third embodiment, the wheel mechanism 50 is arranged to be biased toward one side (one side) in the width direction relative to the driver 61. The rotation speed of the drive shaft 52 is reduced by the first linkage gear 56 to the third linkage gear 58 and transmitted to the second driven shaft 54. In the third embodiment, the number of teeth of each linkage gear 56 to 58 is set in such a manner that the rotation speed of the drive shaft 52 is reduced to 1 / 3 by the first linkage gear 56 to the third linkage gear 58 and transmitted to the second driven shaft 54. Accordingly, in the third embodiment, the rotation speed ratio of the first wheel portion 55 and the second wheel portion 60 is set to 1:3 as in the second embodiment.

[0101] Furthermore, as a result of the interposition of the three first to third interlocking gears 56 to 58, the first wheel portion 55 and the second wheel portion 60 rotate in the same direction. This point is different from the first and second embodiments.

[0102] like Fig.15 As shown, the first wheel portion 55 has seven first engaging portions 55a at equal intervals along the circumferential direction. The range of approximately half of the circumference where the first engaging portions 55a are arranged corresponds to the first engaging circumferential region. The remaining range in the circumferential direction where the first engaging portions 55a are not arranged corresponds to the first non-engaging circumferential region. Fig.16 As shown, the second wheel portion 60 has a second engagement portion 60a. A certain range having the second engagement portion 60a corresponds to the second engagement circumferential region, and the remaining range not having the second engagement portion 60a corresponds to the second non-engagement circumferential region. This is the same as the first and second embodiments.

[0103] like Fig.18 As shown, the driver 61 coupled to the center of the lower surface of the impact piston 4 has a first rack 62 and a second rack 63. As shown in the figure, in the third embodiment, the first rack 62 and the second rack 63 are provided along the side portion of the same side in the width direction of the driver 61. In the third embodiment, the first rack 62 and the second rack 63 are separately arranged on one side and the other side in the thickness direction (direction orthogonal to the width direction) of the driver 61.

[0104] The first rack 62 is Fig.18 The first rack 62 has seven engaging teeth 62a. The seven engaging teeth 62a are arranged at equal intervals in a region substantially on the lower side of the driver 61.

[0105] The second rack 63 is Fig.18 The second rack 63 has two upper and lower engaging teeth 63a and 63b. The lower engaging teeth 63a are repeatedly arranged in the area where the first rack 62 is provided. The upper engaging teeth 63b are separated from the area where the first rack 62 is provided and are arranged at a higher position.

[0106] According to the wheel mechanism 50 according to the third embodiment configured as above, when the electric motor 21 is started and the drive shaft 52 is rotated, the first wheel portion 55 and the second wheel portion 60 rotate in the same direction at a rotation speed ratio of 1:3. Fig.16 As shown in FIG. 1 , when the impact piston 4 reaches the lower moving end and completes the driving, the second engaging portion 60a of the second wheel portion 60 engages with the lower side of the engaging teeth 63b on the upper side of the second rack 63. Fig.16 The driver 61 starts to move upward by rotating in the clockwise direction. Therefore, the second engagement portion 60a functions as a starting engagement portion for starting to move the driver 61 upward. This stage corresponds to the first embodiment. Figure 7 (C) The second embodiment Fig.11 The stage shown in (H).

[0107] When the driver 61 starts to rise from the lower moving end, the first engaging portion 55a of the first wheel portion 55 engages with the engaging teeth 62a of the first rack 62. This stage corresponds to the first embodiment. Figure 7 (D) → (E), the second embodiment Fig.11 The transition stage of the engagement state shown in (I) → (J) in FIG. In this engagement state, the first wheel portion 55 is Fig.15 The driver 61 further moves upwards as the first wheel 55 rotates counterclockwise. When the first wheel 55 rotates about 1 / 3 of a turn and the second wheel 60 rotates about 1 turn, the impact piston 4 moves upwards to the standby position. When the impact piston 4 returns to the standby position, the second engaging portion 60a of the second wheel 60 engages with the lower side of the engaging tooth 63a on the lower side of the second rack 63. This stage corresponds to the first embodiment. Figure 7 (A) and the second embodiment Fig.11 The standby state shown in (F)

[0108] When the standby state is reached, the electric motor 21 stops and the impact piston 4 is kept in the standby position. When the operating switch operating handle 8 is pulled, the electric motor 21 starts to operate the drive return mechanism 20. Accordingly, the driver 61 moves upward and the impact piston 4 moves to the top dead center. By directly maintaining the start state of the electric motor 21 and the driver 61 moving upward, the second engaging portion 60a of the second wheel portion 60 is disengaged from the engaging teeth 63a on the lower side of the second rack 63. Accordingly, the impact piston 4 moves downward by the thrust of the pressure storage chamber 3a to complete the driving action.

[0109] According to the third embodiment constructed as described above, similar to the first and second embodiments, by causing a large load or friction force to act on the second engaging portion 60a of the second wheel portion 60 when the engagement with the second rack 63 is started and when the engagement is released, the load acting on each first engaging portion 55a of the first wheel portion 55 can be reduced. Accordingly, by ensuring the strength and wear resistance required for the second engaging portion 60a of the second wheel portion 60, cost reduction can be achieved compared to the case where high strength and wear resistance are ensured for the entirety including the first wheel portion 55. In addition, in the case of increased wear, since only the second engaging portion 60a of the second wheel portion 60 needs to be replaced, and the first wheel portion 55 can continue to be used as it is, the maintenance cost can be reduced.

[0110] Furthermore, according to the third embodiment, since the wheel mechanism 50 is arranged in a region on one side in the width direction relative to the driver 61, it is possible to further achieve compactness in the width direction of the driving protrusion 5. In addition, similar to the second embodiment, since the rotation speed ratio between the first wheel portion 55 and the second wheel portion 60 is set to 1:3 (integer ratio), it is possible to achieve a smaller diameter of the second wheel portion 60 compared to the case where it is set to 1:2. This also enables compactness of the wheel mechanism 50.

[0111] Further changes can be made to the first to third embodiments described above. For example, instead of a roller body structure that rotatably supports the roller body on the shaft member, the second engaging portion 33a, 42a, 60a of the second wheel portion 33, 42, 60 can be a cylindrical body with high wear resistance.

[0112] Although the gas spring type driving tool 1 using the gas pressure of the gas sealed in the pressure storage chamber 3a as the driving thrust is exemplified, the same can be applied to a mechanical spring type driving tool using the biasing force of a compression spring as the driving thrust.

Claims

1. A driving tool, characterized in that: It has a driver, a driving mechanism, a first rack and a second rack, a first wheel portion, and a second wheel portion, wherein: The driver is disposed on the housing in a manner that it can move up and down, and is used to impact the driven member by moving downward; The driving mechanism accumulates driving energy by moving the driver upward; The first rack and the second rack are arranged on the driver so as to move the driver upward; The first wheel portion has a plurality of first engaging portions engaged with the first rack; The second wheel portion has a second engaging portion engaged with the second rack. The second engaging portion is arranged on the second wheel portion in such a manner that it engages with the second rack only in two stages, an initial stage of upward movement of the driver and a final stage of upward movement of the driver, wherein, in the initial stage of upward movement of the driver, the second engaging portion engages with the second rack at the same time as or before the first engaging portion of the first wheel portion begins to engage with the first rack; and in the final stage of upward movement of the driver, the second engaging portion disengages from the second rack at the same time as or after the first engaging portion of the first wheel portion disengages from the first rack.

2. The driving tool according to claim 1, characterized in that The first wheel portion is arranged on one side of the driver, and the second wheel portion is arranged on the other side.

3. The driving tool according to claim 1, characterized in that The first wheel portion and the second wheel portion are arranged on one side of the driver.

4. The driving tool according to any one of claims 1 to 3, characterized in that: The second engaging portion of the second wheel portion has a roller body structure that rolls relative to the second rack.

5. The driving tool according to any one of claims 1 to 3, characterized in that: The rotation speed ratio between the first wheel portion and the second wheel portion is set to an integer ratio.

6. The driving tool according to any one of claims 1 to 3, characterized in that: The rotation speed of the second wheel portion is faster than the rotation speed of the first wheel portion.

7. The driving tool according to any one of claims 1 to 3, characterized in that: The second engaging portion of the second wheel portion has a strength higher than a strength of the first engaging portion of the first wheel portion.

8. The driving tool according to any one of claims 1 to 3, characterized in that: In the final stage of the upward movement, the strength of the engaging teeth of the second rack is higher than the strength of the engaging teeth of the first rack, wherein the engaging teeth of the second rack engage with the second engaging portion of the second wheel portion, and the engaging teeth of the first rack engage with the first engaging portion of the first wheel portion.

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