Driving tool

Abstract

The invention provides a driving tool. The driving tool (10) is provided with a driving device (1e) for driving a driven material. And the piston (1d) is connected with the driver (1e). The air cylinder (1c) generates air pressure through the piston (1d). The cylinder (1c) is made of iron. The cylinder (1c) is located on or near the movement axis (J1) of the piston (1d). And since the cylinder (1c) is made of iron, the weight of the piston (1d) on the movement axis (J1) becomes larger than that of the cylinder (1c) made of aluminum or resin. The reaction to the movement of the piston (1d) and the striking of the driver (1e) can be suppressed by the weight near the movement axis (J1) of the piston (1d). Accordingly, reaction during driving is reduced.

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] The driving tool of Patent Document 1 has a piston that moves up and down in a cylinder and a driver that is integrally connected to the piston. The piston and the driver move in a driving direction by the air pressure of a pressure accumulator. The moving driver strikes the driven part to eject the driven part. In the driving action, a reaction force is generated on the tool body in both cases when the piston moves in the driving direction and when the driver strikes the driven part.

[0003] The reaction force acts in the direction opposite to the driving direction. This reaction force generates a force that rotates the tool body around the handle held by the user. The reaction (recoil) generated each time a driven part is driven becomes a burden to the user. Sometimes the posture of the driving tool is shaken due to the reaction force. As a result, there is a concern that the driven part may be separated from the striking surface of the driving tool or the ejection port may be separated from the driven material, resulting in failure to drive the driven part correctly. [Prior art literature] [Patent Document]

[0004] Patent Document 1: U.S. Patent No. 11224960 Summary of the invention [Technical problem to be solved by the invention]

[0005] Therefore, there has been a need for a driving tool having a small reaction during driving. [Technical solutions for solving technical problems]

[0006] According to one embodiment of the present invention, the driving tool has a driving device for striking the driven part. The piston is connected to the driving device. The cylinder generates air pressure through the piston. The cylinder is made of iron. Therefore, the cylinder is located on the moving axis of the piston, or near the moving axis of the piston. And because the cylinder is made of iron, the weight on the moving axis of the piston becomes larger than when the cylinder is made of aluminum or resin. Therefore, the weight near the moving axis of the piston can suppress the reaction to the movement of the piston and the impact of the driving device. Accordingly, the reaction during driving is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 It is a right side view of the driving tool involved in the first embodiment of the present invention. Figure 2 This is a right side view with the right side cover removed. Figure 3 yes Figure 1 The III-III section view. Figure 4 It is a left side view of the driving tool involved in the second embodiment of the present invention. Figure 5 This is a front view with the cover removed. Figure 6 It is a three-dimensional diagram of a counterweight. Figure 7 yes Figure 4 VII-VII section view. [Explanation of Reference Numerals] 10: driving tool; 11: tool body; 12: handle; 13: trigger; 14: controller; 15: battery installation part; 16: battery pack; 17: drive part housing; 18: nail magazine; 19: switch; 1: housing; 1a: upper part of housing; 1b: lower part of housing; 1c: cylinder; 1d: piston; 1e: driving tool; 1f: pressure storage chamber; 1g: shock absorber; 1h: lower housing; 1j: inner peripheral surface; L: engaged part; L1: lower end rack; 2: machine head; 2a: driving channel; 2b: ejection port; 2c: contact arm; 3: lifter; 3a: Wheel part; 3b: rotating shaft; P: engaging part; P1: rear end pin; 4: driving part; 4a: motor; 4b: reduction gear system; 5: counterweight; 5a: front part; 5b: left part; 5c: bending part; 5d: upper extension part; 5e: upper groove part; 5f: front protrusion; 5g: lower extension part; 5h: lower groove part; 5p: center of gravity; J1: moving axis; J2: center in left-right direction; J3: motor axis; J4: center in front-back direction; 20: driving tool; 21: housing; 21a: upper part of housing; 21c: cylinder; 21k: first rib; 21m: recess; 21n: second rib. DETAILED DESCRIPTION

[0008] According to another embodiment of the present invention, the cylinder has an inner peripheral surface that slidably holds the piston. The inner peripheral surface is not subjected to surface treatment. Since the cylinder is made of iron, the strength of the inner peripheral surface can be ensured even without surface treatment. Thus, the work of surface treatment can be omitted.

[0009] According to another aspect of the present invention, the cylinder is subjected to heat treatment, thereby further improving the strength of the cylinder.

[0010] According to another embodiment of the present invention, the driving tool has a driving device for striking the driven part. The piston is connected to the driving device. The cylinder generates air pressure through the piston. The housing accommodates the cylinder. The housing is cylindrical and extends in the up-down direction. The counterweight is arranged inside the housing. Therefore, the housing is located near the moving axis of the piston. The weight of the housing is increased due to the counterweight. Therefore, the weight near the moving axis of the piston can suppress the reaction to the movement of the piston and the impact of the driving device. Accordingly, the reaction during driving is reduced.

[0011] According to another aspect of the present invention, a counterweight is arranged around the cylinder. The counterweight is located at the upper and lower positions corresponding to the length range of the cylinder. Therefore, the counterweight can be reliably arranged near the moving axis of the piston. Therefore, the counterweight can further suppress the reaction during driving.

[0012] According to another aspect of the present invention, the counterweight is fixed to the inner wall of the housing. Therefore, the counterweight is integrally mounted to the housing. Accordingly, the counterweight does not wobble inside the housing.

[0013] According to another embodiment of the present invention, the handle extends rearward from the housing. The counterweight is arranged so that the center of gravity of the counterweight is located at a position on the front side of the housing relative to the center in the front-rear direction. Therefore, the counterweight is arranged so that the weight on the side opposite to the handle becomes larger when viewed from the housing. Accordingly, it is easy to maintain the weight balance in the front-rear direction. As a result, the shaking in the front-rear direction caused by the reaction during driving can be reduced.

[0014] According to another embodiment of the present invention, the handle extends to the rear of the housing. The lifter moves the driver upward. The lifter is located at a position closer to the first side on either the left or right side than the center of the handle in the left-right direction. The counterweight is arranged in such a manner that the center of gravity of the counterweight is located on the second side opposite to the first side across the center of the handle in the left-right direction. The counterweight is arranged in such a manner that the weight becomes larger on the side opposite to the first side where the lifter is located. Accordingly, it is easy to maintain the weight balance in the left-right direction centered on the handle. As a result, the shaking in the left-right direction caused by the reaction during driving can be reduced.

[0015] Next, based on Figure 1 to Figure 3 An embodiment of the present invention is described below. Figure 1 As shown, the driving tool 10 is, for example, a gas spring type that uses air pressure to drive the driven part. In the following description, the driving direction of the driven part is defined as the downward direction, and the opposite direction of the driving direction is defined as the upward direction. The user holds the driving tool 10 by hand and Figure 1 The center is on the left side. The user's near side is defined as the rear direction (user side), and the depth side is defined as the front direction. The left and right directions are defined based on the user.

[0016] like Figure 1As shown, the driving tool 10 has a tool body 11. The tool body 11 has a roughly cylindrical outer shell 1. A handle 12 for the user to hold is provided at the rear of the upper portion 1a of the outer shell. The handle 12 is roughly cylindrical. The handle 12 extends rearward. A battery mounting portion 15 is provided at the rear of the handle 12. A battery pack 16 is detachably mounted on the rear surface of the battery mounting portion 15. The battery pack 16 is installed by sliding backward and obliquely downward along the rear surface of the battery mounting portion 15. The battery pack 16 can be removed from the battery mounting portion 15 and repeatedly charged for use using a charger prepared separately. The battery pack 16 can be used as a power source for other electric tools. The battery pack 16 acts as a power source for supplying electric power to the drive unit 4 described later.

[0017] like Figure 2 As shown, the battery mounting portion 15 is a box-shaped component extending up and down. A controller 14 is provided inside the battery mounting portion 15. A roughly cylindrical drive unit housing 17 is integrally connected to the lower front surface of the battery mounting portion 15. The drive unit housing 17 extends in the front-to-back direction. The front portion of the drive unit housing 17 is integrally connected to the rear portion of the lower portion 1b of the housing. The drive unit 4 is accommodated inside the drive unit housing 17. The drive unit 4 has a motor 4a as a drive source and a reduction gear train 4b connected to the motor 4a. The motor 4a is accommodated in a manner such that its axis (motor axis J3) faces the front-to-back direction.

[0018] like Figure 2 As shown, a trigger 13 operated by a user's fingertips is provided on the front lower surface of the handle 12. A switch 19 is provided inside the handle 12 located above the trigger 13. By pulling the trigger 13, the switch 19 is pressed upward and becomes an on state. The on-state switch 19 sends a signal to the controller 14. The controller 14 activates the motor 4a based on the sent signal. The rotation output of the motor 4a is decelerated by the reduction gear train 4b and output to the lifter 3 in front.

[0019] like Figure 2 As shown, the upper portion 1a of the housing accommodates an iron cylinder 1c. Figure 3 As shown, the cylinder 1c holds the piston 1d in a slidable manner. The piston 1d can move in the cylinder 1c in the up-down direction. The cylinder 1c is heat-treated. Thus, the cylinder 1c is not easily worn due to the movement of the piston 1d, and the strength can be ensured. Therefore, the inner peripheral surface 1j of the cylinder 1c does not need to be subjected to the surface treatment required when the cylinder 1c is made of aluminum.

[0020] like Figure 3As shown, the upper portion of the cylinder 1c above the piston 1d is connected to the pressure storage chamber 1f. Compressed gas such as air is sealed in the pressure storage chamber 1f. The air pressure in the pressure storage chamber 1f acts as a thrust to move the piston 1d downward (advance in the driving direction). A driver 1e that is longer vertically is connected to the lower surface of the piston 1d. The driver 1e has a plurality of engaged portions L. Each engaged portion L is arranged to extend to the right from the right side of the driver 1e. Each engaged portion L is formed in the shape of a rack tooth. In detail, the seven engaged portions L are arranged at fixed intervals in the length direction (up and down direction) of the driver 1e.

[0021] like Figure 2 As shown, the lower housing 1b accommodates the lower housing 1h. Figure 3 As shown, the lower housing 1h is connected to the lower part of the cylinder 1c. The lower housing 1h covers a part of the lower surface of the cylinder 1c from below. A shock absorber 1g is provided on the connection surface of the lower housing 1h with the cylinder 1c. The shock absorber 1g is arranged at the lower part of the cylinder 1c. The shock absorber 1g is composed of an elastic body.

[0022] like Figure 3 As shown in FIG. 1 , the lower housing 1h accommodates the lifter 3. The lifter 3 is located at the lower right side of the cylinder 1c. The lifter 3 has a drive unit 4 (see FIG. 1 ). Figure 2 ) and the wheel portion 3a supported by the rotating shaft 3b. The rotating shaft 3b is supported by a bearing (not shown) so as to be rotatable relative to the lower housing 1h. The rotating axis of the rotating shaft 3b is aligned with the motor axis J3 (see Figure 2 When the driving unit 4 is in motion, the rotating shaft 3b and the wheel 3a move together in the direction of the arrow R ( Figure 3 The wheel portion 3a is restricted from rotating in the direction opposite to the arrow R. The lifter 3 has a plurality of engaging portions P arranged along the outer periphery of the wheel portion 3a. Each engaging portion P uses a cylindrical shaft member (pin). Each engaging portion P extends in the front-to-back direction. On the wheel portion 3a, 7 engaging portions P are provided in an area of ​​approximately 3 / 4 of the circumference. The remaining 1 / 4 of the circumference is an avoidance area where no engaging portion P is provided.

[0023] Figure 3 This indicates that the driver 1e is set in a standby position before performing a driving action. Figure 3As shown, one engaged portion L is engaged with one engaging portion P. Specifically, the lower rack L1 located at the bottom of each engaged portion L is engaged with the rear end pin P1 located at the rear end of the rotation direction of the wheel portion 3a in each engaging portion P. The rear end pin P1 is engaged with the lower rack L1 from below. By the engagement of the rear end pin P1 and the clockwise rotation restriction of the wheel portion 3a, the lifter 3 supports the driver 1e from below. Accordingly, the driver 1e and the piston 1d overcome the air pressure of the pressure storage chamber 1f and are maintained in the standby position.

[0024] like Figure 3 As shown, the lower part of the driver 1e in the standby position enters the machine head 2. The machine head 2 is a metal component extending in the up-down direction. The machine head 2 is formed of iron. The upper part of the machine head 2 is accommodated in the lower part 1b of the outer shell. The upper part of the machine head 2 is assembled with the lower shell 1h. The lower part of the machine head 2 protrudes downward from the lower part 1b of the outer shell. The machine head 2 has a driving channel 2a extending in the up-down direction inside it. The driving channel 2a passes on the moving axis J1 of the piston 1d. The lower part of the driver 1e enters the driving channel 2a. The driving channel 2a below the driver 1e is filled with a driving part not shown in the figure.

[0025] like Figure 2 As shown, the rear portion of the machine head 2 is engaged with a magazine 18 loaded with a plurality of driving pieces. The driving pieces are supplied one by one from the magazine 18 to the driving channel 2a in a posture extending up and down. The magazine 18 extends toward the rear of the tool body 11 and in a direction toward the left and upward. A contact arm 2c that can slide up and down is provided at the lower portion of the machine head 2. The contact arm 2c is forced to move downward relative to the machine head 2 (disconnected position). The contact arm 2c moves upward relative to the machine head 2, thereby making the pulling operation of the trigger 13 effective (connected position).

[0026] When using the driving tool 10, the user first Figure 2 The user holds the handle 12 in the direction shown. Then, the user presses the contact arm 2c against the material to be driven from above. Accordingly, the contact arm 2c moves upward relative to the machine head 2. When the user pulls the trigger 13 in this state, the controller 14 rotates the motor 4a of the drive unit 4. Accordingly, the rotation of the motor 4a is transmitted to the lifter 3 through the reduction gear train 4b. Then, as shown in FIG. Figure 3As shown, the rotating shaft 3b rotates in the direction of the arrow R. As a result, the wheel portion 3a rotates in the direction of the arrow R. By the rotation of the wheel portion 3a, the rear end pin P1 passes over the lower end rack L1. As a result, the mutual engagement between the rear end pin P1 and the lower end rack L1 is released. As a result, the piston 1d moves downward by the air pressure of the pressure accumulation chamber 1f. As the piston 1d moves downward, the driver 1e also moves downward. The driver 1e is guided to the driving channel 2a. The driver 1e moves downward along the moving axis J1 of the piston 1d.

[0027] The lower end of the driver 1e moving downward strikes a driven part loaded in the driving channel 2a. The struck driven part is ejected from the ejection port 2b provided at the lower end of the machine head 2. The ejected driven part is driven into the driven material. The piston 1d moving downward collides with the shock absorber 1g. As a result, the downward movement of the piston 1d and the driver 1e stops. The shock absorber 1g absorbs the impact of the piston 1d colliding. The shock absorber 1g prevents the piston 1d from being damaged.

[0028] Even after the downward movement of the piston 1d stops, the wheel portion 3a continues to rotate in the direction of the arrow R. Accordingly, the engaging portion P located at the front in the rotation direction of the wheel portion 3a engages with the engaged portion L located at the top from below. Then, as the wheel portion 3a further continues to rotate, the engaging portion P pushes the engaged portion L upward. As the wheel portion 3a rotates, each engaging portion P pushes each engaged portion L upward in sequence. In this way, the lifter 3 pushes the driver 1e and the piston 1d back to the standby position.

[0029] In the above driving operation, when the piston 1d moves downward and the driver 1e strikes the driven object, a reaction force is generated on the tool body 11. The reaction force acts in the upward direction (the direction opposite to the driving direction) along the moving axis J1 of the piston 1d (see Figure 2 ). Therefore, a reaction occurs in which the driving tool 10 rotates backward and upward with the handle 12 held by the user as the rotation center.

[0030] However, in this embodiment, the cylinder 1c is made of iron. Therefore, compared with a structure in which the cylinder 1c is made of aluminum or resin, the weight of the cylinder 1c becomes larger. Therefore, the cylinder 1c can offset the reaction force acting in the upward direction. As a result, the reaction during driving can be reduced. In addition, the cylinder 1c and the battery pack 16 located behind the handle 12 are balanced in weight. Accordingly, it is easy to maintain the weight balance in the front-to-back direction. As a result, it is easy to suppress the shaking in the front-to-back direction caused by the reaction during driving.

[0031] In addition, since the cylinder 1c is heavier, the total weight of the components housed in the housing upper portion 1a is brought closer to the total weight of the components housed in the housing lower portion 1b. As a result, the center of gravity of the tool body 11 is brought closer to the handle 12. As a result, the operability when the user moves the driving tool 10 is improved. In addition, when the driving tool 10 is used with the moving axis J1 facing the horizontal direction, for example, it is easy to obtain a weight balance of the driving tool 10 in the driving direction.

[0032] As mentioned above, Figure 3 As shown, the driving tool 10 has a driving device 1e for striking the driven object. The piston 1d is connected to the driving device 1e. The cylinder 1c generates air pressure through the piston 1d. The cylinder 1c is made of iron. Therefore, the cylinder 1c is located on the moving axis J1 of the piston 1d, or near the moving axis J1 of the piston 1d. In addition, since the cylinder 1c is made of iron, the weight on the moving axis J1 of the piston 1d becomes larger than when the cylinder 1c is made of aluminum or resin. Therefore, the reaction to the movement of the piston 1d and the impact of the driving device 1e can be suppressed by the weight near the moving axis J1 of the piston 1d. As a result, the reaction during driving is reduced.

[0033] like Figure 3 As shown, the cylinder 1c has an inner peripheral surface 1j that slidably holds the piston 1d. The inner peripheral surface 1j is not subjected to surface treatment. Since the cylinder 1c is made of iron, the strength of the inner peripheral surface 1j can be ensured even without surface treatment. Thus, the labor of surface treatment can be saved.

[0034] like Figure 3 As shown in FIG. 1 , the cylinder 1 c is subjected to heat treatment, thereby further improving the strength of the cylinder 1 c.

[0035] Next, based on Figures 4 to 7 A second embodiment of the present invention will be described. A driving tool 20 of the second embodiment has a housing 21 instead of the housing 1 of the first embodiment. The housing 21 has a housing upper portion 21a and a cylinder 21c. In addition, the driving tool 20 has a counterweight 5. In the following description, only the parts different from the first embodiment will be described in detail.

[0036] like Figure 4 , 5 As shown, the cylinder 21c is housed in the housing upper portion 21a. The cylinder 21c is made of aluminum. The inner peripheral surface of the cylinder 21c is subjected to surface treatment such as hard anodizing treatment. This improves the strength and wear resistance of the cylinder 21c.

[0037] like Figure 4 , Figure 5As shown, the driving tool 20 has a counterweight 5 provided inside the housing upper portion 21a. The counterweight 5 is made of iron. The counterweight 5 increases the weight near the moving axis J1 of the piston 1d. The counterweight 5 is arranged on the front side and the left side of the cylinder 21c. The counterweight 5 is arranged in a manner to be accommodated within the range of the vertical length of the cylinder 21c.

[0038] like Figure 6 As shown, the counterweight 5 is a metal component formed by bending a sheet metal member into a roughly L-shaped cross section. The counterweight 5 has a front portion 5a, a left portion 5b and a curved portion 5c. The front portion 5a, the left portion 5b and the curved portion 5c are formed in a continuous shape. The curved portion 5c connects the central portion in the vertical direction of the left side portion of the front portion 5a and the central portion in the vertical direction of the front side portion of the left portion 5b. In addition, the counterweight 5 has an upper extension portion 5d and a lower extension portion 5g extending to the left from the front portion 5a. The upper extension portion 5d is located above the curved portion 5c. An upper groove portion 5e is provided between the upper extension portion 5d and the curved portion 5c. The lower extension portion 5g is located below the curved portion 5c. A lower groove portion 5h is provided between the lower extension portion 5g and the curved portion 5c. In addition, the counterweight 5 has a front protrusion 5f protruding forward from the right side portion of the front portion 5a.

[0039] like Figure 7 As shown, the housing 21 has a first rib 21k protruding to the right from the inner wall on the left side thereof. The first rib 21k has a recess 21m recessed to the left. The lower extension 5g of the counterweight 5 is embedded in the recess 21m. In addition, the upper extension 5d of the counterweight 5 is also embedded in the recess 21m. Accordingly, the counterweight 5 is positioned relative to the housing 21. In addition, the housing 21 has a second rib 21n protruding from the inner wall on the front side thereof. The second rib 21n supports the front protrusion 5f of the counterweight 5 from the right. Accordingly, the counterweight 5 is prevented from falling off in a manner of detaching from the recess 21m. In the above manner, the counterweight 5 is fixed inside the housing 21.

[0040] like Figure 7 As shown, when viewed from the center of the front-to-back direction of the housing 21 (center J4 in the front-to-back direction), the weight of the counterweight 5 arranged on the front side is greater than the weight arranged on the rear side. That is, the center of gravity 5p of the counterweight 5 is located at a position on the front side of the housing 21 relative to the center J4 in the front-to-back direction. Accordingly, the counterweight 5 can achieve weight balance with the components such as the handle 12 located behind the housing 21. Therefore, it is easy to achieve weight balance in the front-to-back direction with the housing 21 as a reference. As a result, the operability of the driving tool 20 can be improved. In addition, it is easy to suppress the shaking in the front-to-back direction caused by the reaction during driving.

[0041] In addition, when viewed from the center of the handle 12 in the left-right direction (center J2 in the left-right direction), the weight of the counterweight 5 arranged on the left side is greater than the weight arranged on the right side. That is, the center of gravity 5p of the counterweight 5 is located at a position further to the left than the center J2 in the left-right direction of the handle 12. Accordingly, the counterweight 5 can achieve weight balance with components such as the lifter 3 and the drive unit 4 that are arranged further to the right than the handle 12. Therefore, it is easy to achieve weight balance in the left-right direction with the handle 12 as a reference. As a result, the operability of the driving tool 20 can be improved. In addition, it is easy to suppress the shaking in the left-right direction caused by the reaction during driving.

[0042] As described above, the driving tool 20 has a driving device 1e for striking the driven object. The piston 1d is connected to the driving device 1e. The cylinder 21c generates air pressure through the piston 1d. The housing 21 accommodates the cylinder 21c. The housing 21 is cylindrical and extends in the up-down direction. The counterweight 5 is arranged inside the housing 21. Therefore, the housing 21 is located near the moving axis J1 of the piston 1d. The weight of the housing 21 is increased due to the counterweight 5. Therefore, the weight near the moving axis J1 of the piston 1d can suppress the reaction to the movement of the piston 1d and the impact of the driving device 1e. Accordingly, the reaction during driving is reduced.

[0043] like Figure 4 , 5 As shown, the counterweight 5 is arranged around the cylinder 21c. The counterweight 5 is arranged at the upper and lower positions corresponding to the length range of the cylinder 21c. Therefore, the counterweight 5 can be reliably arranged near the moving axis J1 of the piston 1d. Therefore, the counterweight 5 can further suppress the reaction during driving.

[0044] like Figure 7 As shown, the weight 5 is fixed to the inner wall of the housing 21. Therefore, the weight 5 is integrally mounted on the housing 21. Accordingly, the weight 5 does not wobble inside the housing 21.

[0045] like Figure 7 As shown, the handle 12 extends backward from the housing 21. The counterweight 5 is arranged in such a manner that the center of gravity 5p of the counterweight 5 is located at a position forward of the center J4 in the front-rear direction of the housing 21. Therefore, the counterweight 5 is arranged in such a manner that the weight becomes larger on the side opposite to the handle 12 when viewed from the housing 21. Accordingly, it is easy to maintain the weight balance in the front-rear direction. As a result, the shaking in the front-rear direction caused by the reaction during driving can be reduced.

[0046] like Figure 7As shown, the handle 12 extends to the rear of the housing 21. The lifter 3 moves the driver 1e upward. The lifter 3 is located at a position on the first side on either side of the left or right side relative to the center J2 of the handle 12 in the left-right direction. The counterweight 5 is arranged in such a manner that the center of gravity 5p of the counterweight 5 is located on the second side opposite to the first side across the center J2 of the handle 12 in the left-right direction. The counterweight 5 is arranged in such a manner that the weight becomes larger on the side opposite to the first side where the lifter 3 is located. Accordingly, it is easy to maintain the weight balance in the left-right direction centered on the handle 12. As a result, the shaking in the left-right direction caused by the reaction during driving can be reduced.

[0047] Various changes can be made to the above-described embodiments. For example, a structure in which a heat treatment is applied to an iron cylinder is illustrated. In addition, the inner peripheral surface of the iron cylinder can also be ground. This can further suppress the wear of the inner peripheral surface.

[0048] As a structure for increasing the weight near the moving axis of the piston, the structure of providing an iron cylinder is exemplified in the first embodiment. In addition, the structure of providing a counterweight around the aluminum cylinder is exemplified in the second embodiment. Instead of this, a counterweight may be provided around the iron cylinder.

[0049] The number, shape, size, etc. of the counterweights are not limited to the counterweight 5 illustrated, and may be appropriately changed. In the second embodiment, a structure in which the counterweights are arranged on the front side and the left side of the cylinder is illustrated. Instead, the counterweights may be arranged on the entire circumference of the cylinder. Other counterweights may be arranged around the cylinder at will. If the counterweight is arranged in the outer shell, it may also be arranged around or inside the lower shell, or around the head of the machine. In addition to iron, the counterweight may also be made of metals such as brass, copper, and aluminum.

[0050] The structure in which the counterweight is inserted into the groove provided on the inner wall of the cylinder is illustrated. Instead, the counterweight may be fixed by being hooked on the claw provided on the inner wall. In addition, the counterweight may be bonded to the inner wall of the housing.

[0051] The lifter may also be located at a position closer to the left side than the center of the left-right direction of the grip. In this case, the center of gravity of the preferred counterweight is located at a position closer to the right side than the center of the left-right direction.

[0052] The driving tool 10 of the embodiment is an example of a driving tool in one embodiment of the present invention. The driving device 1e of the embodiment is an example of a driving device in one embodiment of the present invention. The piston 1d of the embodiment is an example of a piston in one embodiment of the present invention. The cylinder 1c of the embodiment is an example of a cylinder in one embodiment of the present invention.

[0053] The inner peripheral surface 1j of the embodiment is an example of the inner peripheral surface in one embodiment of the present invention.

[0054] The housing 21 of the embodiment is an example of a housing in one embodiment of the present invention. The weight 5 of the embodiment is an example of a weight in one embodiment of the present invention.

[0055] The recessed portion 21 m of the example is an example of an inner wall in one embodiment of the present invention.

[0056] The lifter 3 of the embodiment is an example of a lifter in one embodiment of the present invention.

Claims

1. A driving tool, characterized in that: It has a driver, a piston and a cylinder, wherein: The driver is used to strike the driven piece; The piston is connected to the driver; The cylinder generates air pressure through the piston, The cylinder is made of iron.

2. The driving tool according to claim 1, characterized in that The cylinder has an inner peripheral surface that slidably holds the piston. The inner peripheral surface is not subjected to surface treatment.

3. The driving tool according to claim 1 or 2, characterized in that: The cylinder is heat treated.

4. A driving tool, characterized in that: It has a driver, a piston, a cylinder, a housing and a counterweight, wherein: The driver is used to strike the driven piece; The piston is connected to the driver; The cylinder generates air pressure through the piston; The housing accommodates the cylinder and is in a cylindrical shape extending in the up-down direction; The counterweight is disposed inside the housing.

5. The driving tool according to claim 4, characterized in that The counterweight is arranged around the cylinder and located at corresponding upper and lower positions within the length range of the cylinder.

6. The driving tool according to claim 4 or 5, characterized in that The counterweight is fixed to the inner wall of the housing.

7. The driving tool according to any one of claims 4 to 6, characterized in that: A handle is provided, the handle extending rearwardly from the housing, The counterweight is disposed so that the center of gravity of the counterweight is located forward of the center of the housing in the front-rear direction.

8. The driving tool according to any one of claims 4 to 7, characterized in that: With a handle and a lifter, wherein The handle extends rearwardly from the housing; The lifter moves the driver upward. The lifter is located at a first side on either side of the left and right sides relative to the left-right center of the handle. The weight is arranged so that the center of gravity of the weight is located on a second side opposite to the first side across the center of the handle in the left-right direction.

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