Patent ID: 12186871

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. Throughout the drawings, the same members are denoted by the same reference characters.

A driving machine10illustrated inFIGS.1to5includes a housing11. The housing11includes a cylinder case portion11aaccommodating a cylinder12, and a motor case portion11bintegrated with a front end portion of the cylinder case portion11a. A handle portion11cis integrated with a top portion of the cylinder case portion11aalong the motor case portion11b. A connecting portion11dis integrally provided between a front end portion of the handle portion11cand a front end portion of the motor case portion lib. As described above, the housing11includes the cylinder case portion11a, the motor case portion11b, the handle portion11c, and the connecting portion11d. The housing11includes two housing halves, and the housing11is assembled by fixing the two housing halves to each other. The two housing halves are separately formed of synthetic resin such as nylon or polycarbonate.

A cylindrical cylinder12is accommodated in the cylinder case portion11a, and the cylinder12has a cylinder hole12a. A piston13is provided movably in the cylinder hole12a. An operational direction of the piston13is a direction of a center axis O1of the cylinder12. The cylinder12is integrally formed of a metal material such as aluminum. Assuming that an upper end of the cylinder12illustrated inFIG.8is a top portion140and a lower end of the cylinder12illustrated inFIG.7is a front end portion141, the piston13can reciprocate between the front end portion141and the top portion140of the cylinder12. The top portion140and the front end portion141of the cylinder12are located farthest from each other in the direction of the center axis O1of the cylinder12. The direction of the center axis O1is a direction parallel to the center axis O1, that is, the direction along the center axis O1.

A piston chamber14is formed by a top surface of the piston13. A driver blade15is connected to the piston13. A nose portion16is provided in the cylinder case portion11aof the housing11. An ejection port17is provided in the nose portion16. The driver blade15is supported so as to be capable of reciprocating in the direction of the center axis O1within the ejection port17. The driver blade15is disposed so as to extend from the inside of the cylinder case portion11athrough the ejection port17to the outside of the housing11.

A magazine18accommodating a large number of fasteners82is attached to the housing11. The fasteners82in the magazine18are supplied one by one to the ejection port17. The driver blade15applies driving force to the fastener82supplied to the ejection port17, and drives the fastener82into a workpiece such as wood or a gypsum board. An operator holds the handle portion11cwhen driving the fastener82and makes the center axis O1of the cylinder12perpendicular to a surface of the workpiece.

As illustrated inFIG.2, the motor case portion11bis disposed so as to be shifted to one side in a width direction of the driving machine10with respect to the handle portion11c, and the magazine18is disposed so as to be inclined on an opposite side in the width direction with respect to the motor case portion11b. As illustrated inFIG.1, the magazine18is inclined downward from a rear end portion toward a front end portion. However, the magazine18may be disposed at a right angle to the cylinder12.

As illustrated inFIGS.3,4,6,7, and8, protruding portions21,22, and130protruding from an inner surface of the cylinder case portion11aare provided. The protruding portions21,22, and130are disposed at intervals in the direction of the center axis O1. The protruding portions22and130are disposed between the protruding portion21and the nose portion16in the direction of the center axis O1. The protruding portion130is disposed between the protruding portion22and the nose portion16in the direction of the center axis O1. Each of the protruding portions21,22, and130has an annular shape and is disposed in the cylinder case portion11a. The protruding portion21forms a support hole21a, the protruding portion22forms a support hole22a, and the protruding portion130forms a support hole130a. The support holes21a,22a, and130aare concentrically arranged, and part of the cylinder12in the direction of the center axis O1is disposed in the support holes21a,22a, and130a. An inner diameter of the support hole130ais greater than an inner diameter of the support hole22a. In addition, a support groove132is provided between the protruding portion22and the protruding portion130. The support groove132is annular.

As illustrated inFIGS.3,4, and7, in the cylinder case portion11a, a holder23is provided at a location including the front end portion141of the cylinder12in the direction of the center axis O1. The holder23is connected to the nose portion16, and the cylinder12is connected to the holder23. The location where the holder23is connected to the cylinder12is an end portion of the cylinder12closer to the nose portion16. The holder23includes an end wall portion23aand a cylindrical portion23b. An inner diameter of the cylindrical portion23bis greater than an outer diameter of the cylinder12, and the end wall portion23ahas a through hole24. The driver blade15is disposed so as to be movable into the through hole24.

The holder23is disposed between the protruding portion22and the nose portion16in the direction of the center axis O1. A male thread12bis formed on an outer peripheral surface of the cylinder12, and a female thread23dis formed on an inner peripheral surface of the cylindrical portion23b. The cylinder12and the holder23are screw-coupled and fixed to each other in the direction of the center axis O1. In the direction of the center axis O1, a region where the cylinder12is disposed overlaps with a region where the holder23is disposed, and thus, an overlapping portion X1is formed. The cylinder12and the holder23are screw-coupled to each other at the overlapping portion X1.

A flange131protruding outward in the radial direction is provided on the outer peripheral surface of the cylindrical portion23b. The flange131has an annular shape, and the flange131is disposed in the support groove132. An outer diameter of the flange131is greater than the inner diameter of each of the support holes22aand130a. A vibration damping rubber133is disposed in the support groove132. The vibration damping rubber133is annular and has a U-shaped cross section. The vibration damping rubber133covers the flange131over the entire circumference. The vibration damping rubber133is interposed between the flange131, and the protruding portions22and130. The flange131is engaged with the protruding portions22and130in the direction of the center axis O1via the vibration damping rubber133. That is, the holder23is positioned in the direction of the center axis O1by the protruding portions22and130. In addition, the holder23is positioned in the radial direction by an inner surface of the support groove132.

FIGS.1and3illustrate a state where the driver blade15is driven out by the piston13and the piston13is in an advanced position. The advanced position is a bottom dead center at which the piston13is pressed against the damper25.FIG.4illustrates a state where the piston13is pushed by the driver blade15and the piston13is in a retracted position. The retracted position is a top dead center where the piston13is most distant from the damper25. A recess23cis provided in the end wall portion23a, and the damper25is disposed in the recess23c. The damper25is integrally formed of a rubber-like elastic body or urethane, and a region where the damper25is disposed includes a location where the front end portion141is disposed in the direction of the center axis O1. When the piston13operates and a flange61of the driver blade15collides with the damper25, the damper25attenuates and reduces an impact load.

A rotary disc26is provided for moving the piston13to the retracted position illustrated inFIG.4. A cylindrical accommodating portion137is provided in the cylinder case portion11a, and the rotary disc26is accommodated in the accommodating portion137. The accommodating portion137is continuously integrally formed with the holder23. The rotary disc26is provided on a drive shaft27. As illustrated inFIG.1, the drive shaft27is rotatably supported by bearings28aand28battached to the motor case portion11b. A rack31including a plurality of rack claws31ais attached to the driver blade15, and a plurality of pins32engaged with and disengaged from the rack claws31aare attached to the rotary disc26at intervals in a circumferential direction.

As illustrated inFIGS.1and3, a rotation center axis R of the rotary disc26is shifted in a radial direction of the cylinder12by a distance C with respect to the center axis O1of the cylinder12, and is substantially at a right angle with respect to the center axis O1. InFIG.1, a cross section of a portion around the rotation center axis R and a cross section of a portion around the center axis O1are illustrated. The center axis O1is a virtual line, a center line, or an axis defined from the viewpoint of mechanical engineering, and the center axis O1does not exist as an object.

In order to rotate the rotary disc26, an electric motor33is provided in the motor case portion11b. The electric motor33includes a stator33afixed to the motor case portion11b, and a rotor33brotatably provided in the stator33a. A cooling fan35is attached to a motor shaft34provided on the rotor33b, and cooling air for cooling the electric motor33is generated in the housing11by the cooling fan35. The housing11is provided with an intake hole, not illustrated, for introducing outside air, and a discharge hole, not illustrated, for discharging air which has cooled the motor.

A planetary reduction gear36is provided in the motor case portion11b. An input shaft37aof the reduction gear36is connected to the motor shaft34, and an output shaft37bof the reduction gear36is connected to the drive shaft27. The motor shaft34is rotatably supported by a bearing38aattached to the motor case portion11b. The motor shaft34is connected to the input shaft37a, and a reduction gear holder39is provided in the motor case portion11b. A bearing38bis provided in the reduction gear holder39. The input shaft37ais rotatably supported by the bearing38b. A gear case138is provided in the motor case portion11b, and the reduction gear36is accommodated in the gear case138. The gear case138is fixed to the holder23with a fixing element.

A battery40is attached to the connecting portion11d. The battery40can be attached to and detached from the connecting portion11d, and the battery40supplies power to the electric motor33. The battery40includes an accommodation case40a, and a plurality of battery cells accommodated in the accommodation case40a. The battery cell is a secondary battery such as a lithium-ion battery, a nickel-metal hydride battery, a lithium-ion polymer battery, a nickel-cadmium battery, or the like.

As illustrated inFIG.8, an accumulator41is provided outside the cylinder12in the direction of the center axis O1of the cylinder12. The cylinder case portion11aincludes an opening11e, and the top portion140of the cylinder12in the direction of the center axis O1is disposed outside the cylinder case portion11athrough the opening11e. The accumulator41includes a main body134and a holder139. Both the main body134and the holder139are formed of a metal material. The main body134includes a cylindrical portion44and a top wall portion43continuous with the cylindrical portion44. The holder139includes an annular bottom wall portion42, a protruding portion46extending from the bottom wall portion42in the direction of the center axis O1, and a protruding portion48extending from the bottom wall portion42in the direction of the center axis O1. An outer diameter of the protruding portion46is smaller than an inner diameter of the cylindrical portion44, and the protruding portion46is disposed in the cylindrical portion44. In addition, the protruding portion48and the protruding portion46extend from the bottom wall portion42in opposite directions. An outer diameter of the protruding portion48is smaller than an inner diameter of the protruding portion46.

The top wall portion43faces the top portion of the cylinder12and the bottom wall portion42. A compression chamber45communicating with the piston chamber14is formed inside the accumulator41. The top portion140forms an inner surface of the compression chamber45. As illustrated inFIG.5, the bottom wall portion42is an element having a circular outer peripheral surface. A center O2of the bottom wall portion42is eccentric from the center axis O1of the cylinder12toward the handle portion11cby an amount E of eccentricity. The bottom wall portion42is shifted with respect to the cylinder12in the radial direction. Therefore, the compression chamber45of the accumulator41is eccentric with respect to the center axis O1of the cylinder12.

An outer diameter of the cylindrical portion44of the accumulator41is greater than the outer diameter of the cylinder12. Therefore, compared with a case where the compression chamber45is formed within a projected area of the top portion140of the cylinder12, a length of the driving machine10in the vertical direction including the cylinder12and the accumulator41can be made shorter. The projected area of the top portion140is an area of a circle formed by an outer peripheral edge of the top portion140on a plane perpendicular to the center axis O1. Thus, it is possible to downsize the driving machine10.

As illustrated inFIG.8, a seal member47ais attached to an outer peripheral surface of the protruding portion46. The seal member47ahermetically seals the space between the cylindrical portion44and the protruding portion46. A flange135is provided at an end portion of the cylinder12in the direction of the center axis O1, the end portion being located in the accumulator41. The flange135protrudes radially outward from the outer peripheral surface of the cylinder12. The flange135is annular, and an outer diameter of the flange135is greater than an inner diameter of the protruding portion48. Therefore, when the flange135and the protruding portion48are engaged with each other, movement of the accumulator41with respect to the cylinder12in the direction of the center axis O1is restricted. A seal member47bis attached to the outer peripheral surface of the cylinder12. The seal member47bhermetically seals the space between the cylinder12and the protruding portion48.

A cover51is provided for covering the opening11eand the accumulator41. The cover51is disposed outside the cylinder case portion11a. The cover51includes a cylindrical portion51aand a disc portion51bcontinuous with the cylindrical portion51a. The cover51is integrally formed of a synthetic resin or a metal material. An inner diameter of the cylindrical portion51ais greater than an outer diameter of the accumulator41. An end portion of the cylindrical portion51ain the direction of the center axis O1contacts the cylinder case portion11a.

Furthermore, connecting elements136are provided for connecting the cover51and the accumulator41. The connecting element136is a shaft member, and the connecting element136connects the bottom wall portion42and the disc portion51b. In a state where the cover51and the accumulator41are connected by the connecting elements136, the cover51can move within a predetermined range in the direction of the center axis O1with respect to the accumulator41. The plurality of connecting elements136are provided and disposed radially outside with respect to the cylindrical portion44. Therefore, airtightness of the compression chamber45is not deteriorated by the connecting elements136. Furthermore, a sheet-like vibration damping rubber52is interposed between the disc portion51band the top wall portion43.

Furthermore, an annular vibration damping rubber53is disposed between the protruding portion21and the outer peripheral surface of the cylinder12. An inner diameter of the support hole21ais greater than the outer diameter of the cylinder12, and the vibration damping rubber53is attached in the support hole21a. The vibration damping rubber53prevents the cylinder12from vibrating in a direction crossing the center axis O1, for example, in the radial direction. Each of the vibration damping rubber52,53, and133is integrally formed of a soft material having rubber elasticity, for example, urethane or elastomer. The soft material means a material having rigidity lower than the rigidity of the metal forming the cylinder12.

Air is filled as a gas inside the piston chamber14and the compression chamber45. Air is a compressible gas. As illustrated inFIG.1, in a case where the piston13pressed against the damper25moves toward the compression chamber45, the following control is performed. First, power of the electric motor33is transmitted to the rotary disc26via the reduction gear36, and the rotary disc26rotates in the counterclockwise direction inFIG.3. When the rotary disc26rotates, the pins32sequentially mesh with the rack claws31a, and the piston13rises to an opening end of the cylinder12, that is, the top dead center as illustrated inFIG.4. In this manner, in a stroke in which the piston13rises, compressed air in the piston chamber14enters the compression chamber45. When the piston13reaches the top dead center, pressure of the compressed air in the compression chamber45becomes maximum. After the piston13has reached the top dead center, the rotary disc26rotates, and the pin32and the rack claw31aare disengaged from each other. Then, the piston13moves from the top dead center to the bottom dead center due to the pressure of the compressed air in the compression chamber45. A rotation angle of the rotary disc26is detected by an angle detection sensor, not illustrated.

The nose portion16is provided with a push rod54such that the push rod54can freely reciprocate in the axial direction. The push rod54is also called a contact arm. A compression coil spring55for urging the push rod54is provided. The push rod54is pushed in the direction away from the damper by force of the compression coil spring55, that is, in the downward direction inFIG.1. When the push rod54abuts against the workpiece and the push rod54retracts against force of the compression coil spring55, a pressing detection sensor, not illustrated, detects that the push rod54has been pressed against the workpiece. The handle portion11cis provided with a trigger56, and an operation state of the trigger56is detected by a trigger switch57.

A controller58is provided in the housing11. Detection signals from the angle detection sensor, the pressing detection sensor, and the trigger switch57described above are sent to the controller58. The electric motor33rotates when the trigger56is operated in a state where the piston13is in the advanced position as illustrated inFIGS.1and3, and when the push rod54abuts against the workpiece and the trigger switch57is turned on. A rotary force of the electric motor33is transmitted to the rotary disc26via the reduction gear36, and the piston13moves to the retracted position. When the pin32is disengaged from the rack claw31a, the piston13moves to the advanced position by compressed air in the compression chamber45, and the driver blade15drives the fastener82into the workpiece.

As illustrated inFIGS.3and4, a flange61contacting the damper25is provided at a base end portion of the driver blade15. A connecting portion62protrudes upward from the flange61. When the flange61collides with the damper25, the damper25reduces or attenuates kinetic energy of the piston13and the driver blade15. A recess63is provided in the piston13, and the connecting portion62is disposed in the recess63. A long hole64extending in the direction of the center axis O1is provided in the connecting portion62. A piston pin65is disposed in the long hole64, and a long axis of the long hole64is greater than an outer diameter of the piston pin65. A retaining ring66is attached to the piston13, and the retaining ring66contacts both end portions of the piston pin65. The retaining ring66prevents the piston pin65from coming off from the piston13. A seal member67is attached to an outer peripheral portion of the piston13, and the seal member67seals the space between the piston13and the cylinder hole12a. Note that the flange131is provided outside a range where the seal member67slides on an inner surface of the cylinder12in the direction of the center axis O1. The range where the seal member67slides on the inner surface of the cylinder12means the range where the seal member67slides on the inner surface of the cylinder12when the piston13reciprocates between the top dead center and the bottom dead center.

As described, the driver blade15and the piston13are connected to each other via the piston pin65. Therefore, the driver blade15can move in the radial direction of the piston13with respect to the piston13. Accordingly, even when force in the radial direction of the cylinder12is applied to the driver blade15, the piston13can be prevented from being pressed against the inner surface of the cylinder12.

In order to fill the compression chamber45with compressed air, a filling valve71illustrated inFIG.1is provided. The filling valve71is provided in the bottom wall portion42of the accumulator41. A base end portion of the filling valve71is fixed to the bottom wall portion42with a nut72, and a front end portion of the filling valve71protrudes below the bottom wall portion42, that is, toward a cylinder12side. A joint portion73is provided at a front end portion of the filling valve71. When the compression chamber45is filled with compressed air, a supply port of one of various compressed gas supply means such as a compressor, an inflator, and a gas cylinder is connected to the joint portion73. The filling valve71incorporates a check valve inside. When the supply port of the compressed air supply means is connected to the joint portion73, the check valve is opened, and the compression chamber45is filled with a compressed gas such as compressed air. When the supply port is removed from the joint portion73, the filling valve71is closed by the check valve.

In order to connect the supply port to the joint portion73of the filling valve71, an opening, not illustrated, is provided in the housing11. When the driving machine10is assembled, the compressed air supply means supplies compressed air to the compression chamber45by using the filling valve71. Furthermore, in a case where gas pressure in the compression chamber45lowers, compressed air is supplied to the compression chamber45by the pressure supply means. In contrast, when the cylinder12is taken out from the inside of the housing11, the check valve incorporated in the filling valve71is operated with an operation tool, and the gas in the compression chamber45is discharged to the outside. In addition, an operator can manually operate a relief valve81to discharge the gas in the compression chamber45to the outside of the compression chamber45.

The relief valve81is provided in the bottom wall portion42in order to discharge the compressed air in the compression chamber45to the outside in a case where pressure in the compression chamber45exceeds a set value. This set value is set to the pressure of the compression chamber45necessary for driving the fastener82having the maximum length to be driven by the driving machine10.

As illustrated inFIGS.1and2, the filling valve71and the relief valve81are provided in the bottom wall portion42protruding outward in the radial direction of the cylinder12. Thus, a space below the bottom wall portion42, that is, a space formed on the cylinder12side is used to dispose the filling valve71and the relief valve81. Accordingly, it is possible to prevent a diameter of the cylinder case portion11afrom increasing. Especially, as illustrated inFIGS.1and2, when the filling valve71and the relief valve81are disposed in the space between the handle portion11cand the cylinder12, since the accumulator41is disposed to be shifted toward the handle portion11cwith respect to the center axis O1of the cylinder12, the space below the compression chamber45is effectively used for disposing the filling valve71and the relief valve81in the space.

The magazine18is attached to the nose portion16and the connecting portion11d. The fasteners82are accommodated side by side in the magazine18, and the fastener82is supplied to the ejection port17by spring force.

The reduction gear36illustrated inFIG.1includes a plurality of sets of planetary gear mechanisms. The plurality of sets of planetary gear mechanisms are arranged in a power transmission path between the input shaft37aand the output shaft37b. In addition, the reduction gear36includes a gear case120, and a plurality of planetary gear mechanisms are accommodated in the gear case120. The rotary force of the electric motor33is transmitted to the rotary disc26via the reduction gear36.

Next, a control system of the driving machine10will be described briefly. A wheel angle detection switch is provided for detecting the rotation angle of the rotary disc26. A push rod switch is provided for detecting a position of the push rod54and outputting a signal. A phase detection sensor is provided for detecting a rotation angle and the number of revolutions of the motor shaft34. Signals from the above switches and sensor are input to the controller58, and the controller58controls stop, rotation, and rotation speed of the motor shaft34of the electric motor33.

States of the driving machine10will be sequentially described.

(State in which Driving Machine is not Used)

A state in which the driving machine10is not used is a state where the push rod54is separated from the workpiece and operating force of the trigger56is released. The controller58stops the electric motor33when the driving machine10is in this non-used state described above. That is, the piston13is pushed toward the damper25by air pressure of the compression chamber45, and as illustrated inFIG.9, the flange61is pressed against the damper25, whereby the piston13and the driver blade15are stopped.

In a case where the push rod54is separated from a workpiece W1and the operating force of the trigger56is released, the cylinder12does not receive a load in the direction crossing the center axis O1. In addition, the vibration damping rubber53is pressed against the outer peripheral surface of the cylinder12and is elastically deformed. That is, the vibration damping rubber53has a predetermined tightening allowance in the radial direction of the cylinder12. Furthermore, the vibration damping rubber133is elastically deformed by being sandwiched between the flange131and the inner surface of the support groove132. That is, the vibration damping rubber133has a predetermined tightening allowance in the radial direction of the cylinder12.

Furthermore, in a case where the push rod54is separated from the workpiece W1and the operating force of the trigger56is released, the vibration damping rubber133is sandwiched between the flange131and the protruding portions22and130and is elastically deformed. That is, the vibration damping rubber133has a predetermined tightening allowance in the direction of the center axis O1.

(Operation of Pressing Push Rod Against Workpiece)

When an operator holds the handle portion11cby hand and presses the push rod54against the workpiece W1with a load F1in the direction of the center axis O1as illustrated inFIG.10, reaction force F2against the load F1is generated. The reaction force F2is transmitted to the holder23via the compression coil spring55and the nose portion16. The reaction force F2and the load F1act in opposite directions. As illustrated inFIG.7, the reaction force F2is transmitted to the vibration damping rubber133via the flange131of the holder23. The vibration damping rubber133is elastically deformed, whereby the reaction force F2transmitted to the handle portion11cis reduced. In addition, the holder23and the cylinder12receive the reaction force F2and move by a predetermined amount in the direction of the center axis O1with respect to the housing11. In addition, frictional force is generated between the outer peripheral surface of the cylinder12and the vibration damping rubber53.

In contrast, in a case where the push rod54is pressed against the workpiece W1in a direction inclined with respect to the center axis O1, a load in the direction crossing the center axis O1acts on the cylinder12. The load applied to the cylinder12in the direction crossing the center axis O1includes a load in the radial direction of the cylinder12. When the cylinder12receives the load in the direction crossing the center axis O1, the vibration damping rubbers53and133are elastically deformed, and the load received by the cylinder12is reduced. Note that an inner diameter of the protruding portion21is greater than the outer diameter of the cylinder12, and a gap is set between the outer peripheral surface of the cylinder12and the protruding portion21. The gap is set to a value such that the outer peripheral surface of the cylinder12does not contact the protruding portion21even if the cylinder12moves in the radial direction with respect to the housing11and the vibration damping rubber53is elastically deformed.

Furthermore, the controller58rotates the electric motor33when the push rod54is pressed against the workpiece W1and operating force is applied to the trigger56. The rotary force of the electric motor33is transmitted to the rotary disc26via the reduction gear36. When the rotary disc26rotates in the counterclockwise direction inFIG.3and the pin32meshes with the rack31, the driver blade15rises from the bottom dead center to the top dead center as illustrated inFIG.10, and the air pressure in the compression chamber45rises.

(In Driving of Fastener)

After the driver blade15has moved due to the rotary force of the electric motor33and the driver blade15has reached the top dead center as illustrated inFIG.4, the pin32is separated from the rack31. Then, the driver blade15moves in the direction of the center axis O1from the top dead center to the bottom dead center due to the air pressure of the compression chamber45. Then, the driver blade15collides with the fastener82located at the ejection port17, and the driver blade15drives the fastener82into the workpiece W1as illustrated inFIG.11.

When the driver blade15drives the fastener82with a load F3, reaction force F4against the load F3is transmitted to the driver blade15and the piston13. In addition, part of the reaction force F4is transmitted to the holder23via the nose portion16. The direction of the reaction force F4is opposite to the direction of the load F3.

Therefore, when the driver blade15hits the fastener82, the holder23receives part of the reaction force F4in the direction of the center axis O1. Therefore, the holder23receives a load in the direction of the center axis O1, and the vibration damping rubber133is elastically deformed. Thus, the load is absorbed and relieved, and the cylinder12is kept positioned relative to the housing11in the direction of the center axis O1.

Since this impact is received by the flange131provided on the holder23, a load that causes deformation of the portion of the cylinder12on which the seal member67slides inFIG.6, is not applied. Therefore, air leakage due to deformation of the cylinder12does not occur. In addition, since it is unnecessary to consider deformation of the cylinder12due to the impact force, it is possible to reduce a thickness of the cylinder12, and thus, a weight of the cylinder12can be reduced. In addition, in the above embodiment, the cylinder12and the holder23are separate components, and the cylinder12and the holder23are fixed to each other. However, even if the cylinder12and the holder23are configured to have an integrated structure, a similar effect can be obtained. The integrated structure of the cylinder12and the holder23means that the cylinder12and the holder23are configured to be a single component or are integrally formed.

In addition, when the holder23receives the load in the direction of the center axis O1, frictional force is generated between the outer peripheral surface of the cylinder12and the vibration damping rubber53. Therefore, the cylinder12receives a load in the direction of the center axis O1at only one spot in the direction of the center axis O1, that is, only at a screw-fixing spot between the cylinder12and the holder23. That is, the cylinder12hardly receives a compression load or a tensile load in the direction of the center axis O1.

In addition, when the driver blade15drives the fastener82into the workpiece W1, the driver blade15descends with excessive kinetic energy, and the flange61collides with the damper25. Here, part of the kinetic energy of the driver blade15and the piston13is absorbed by the damper25. However, the remaining kinetic energy unable to be absorbed by the damper25is transmitted to the holder23. That is, the holder23receives a load F5in the direction of the center axis O1illustrated inFIG.7. The direction of the load F5is identical to the direction of the load F3illustrated inFIG.11. When the holder23receives the load F5, the vibration damping rubber133is elastically deformed. Thus, the load F5received by the holder23is absorbed and relieved.

Furthermore, when the holder23receives the load F5in the direction of the center axis O1, frictional force is generated between the outer peripheral surface of the cylinder12and the vibration damping rubber53. Therefore, even if the cylinder12receives a load in the direction of the center axis O1, the load acts on only one spot in the direction of the center axis O1, that is, only the spot connected to the holder23. That is, the cylinder12hardly receives a compression load or a tensile load in the direction of the center axis O1.

Note that, when the fastener82is driven into the workpiece W1and is stopped, the driving machine10floats up due to reaction force applied to the driver blade15as illustrated inFIG.9, the push rod54separates from the workpiece W1, and the push rod54is returned to the original position by force of the compression coil spring55. Furthermore, the driver blade15separates from the fastener82.

As described above, in a case where the push rod54is pressed against the workpiece W1or in a case where the fastener82is driven into the workpiece W1by the driver blade15, the reaction force and the load in the direction of the center axis O1acting on the holder23are received by the housing11via the vibration damping rubber133without being received by the cylinder12. Therefore, it is possible to prevent the cylinder12from receiving the compression load or the tensile load in the direction of the center axis O1. In addition, a load in the radial direction applied to the cylinder12is absorbed or relieved by the vibration damping rubber53and133. Therefore, strength design of the housing11that holds the cylinder12is facilitated, and it is possible to reduce a size or a weight of the driving machine10. In addition, it is possible to relieve the impact load transmitted to the handle portion11cwhich an operator holds by hand, so that the driving machine10with a good feeling of use can be provided.

Furthermore, the accumulator41and the cover51are connected by the connecting elements136as illustrated inFIG.8. When the pressure in the compression chamber45rises, the top wall portion43receives the pressure, and the main body134receives a load F6in a direction away from the protruding portion21in the direction of the center axis O1. Then, part of the load F6is transmitted to the cover51via the vibration damping rubber52. The cover51is pushed away from the protruding portion21in the direction of the center axis O1, and moving force of the cover51is transmitted to the holder139via the connecting elements136. Then, the protruding portion48is engaged with the flange135. In this manner, the accumulator41is positioned in the direction of the center axis O1.

Furthermore, a case will be described where an object contacts the cover51and the cover51receives a load F7in the direction of the center axis O1. The direction of the load F7is opposite to the direction of the load F6. When the cover51receives the load F7, the vibration damping rubber52is elastically deformed. Thus, the impact is absorbed and relieved. In addition, when part of the load F7is transmitted to the main body134via the vibration damping rubber52, the main body134moves toward the protruding portion21in the direction of the center axis O1. Moving force of the main body134is transmitted to the holder139, and the holder139moves toward the protruding portion21in the direction of the center axis O1. Therefore, it is possible to prevent the cylinder12from receiving the load in the direction of the center axis O1. When the accumulator41approaches the protruding portion21in the direction of the center axis O1, the cylindrical portion51aand the cylinder case portion11acontact each other, and the housing11receives a load. Furthermore, impact in driving does not cause the top wall portion43of the accumulator41to collide with the cover51, and damage of the cover51caused by the impact can be prevented.

Next, another example of the structure in which the housing11supports the cylinder12in the direction crossing the center axis O1will be described with reference toFIG.12. A range where the protruding portion21is disposed overlaps with a range where the protruding portion48is disposed in the direction of the center axis O1. The inner diameter of the protruding portion21is greater than the outer diameter of the protruding portion48, and the vibration damping rubber53is provided on an inner periphery of the protruding portion21. The vibration damping rubber53is pressed against an outer peripheral surface of the protruding portion48and is elastically deformed. When the cylinder12receives a load in the direction crossing the center axis O1, the load is transmitted to the vibration damping rubber53via the holder139. The vibration damping rubber53is elastically deformed to absorb and relax the load. Furthermore, when the cylinder12vibrates in the direction of the center axis O1together with the holder23, frictional force is generated at a contact spot between the seal member47band the protruding portion48or a contact spot between the protruding portion48and the vibration damping rubber53.

Here, the correspondence between the configuration described in the present embodiment and the configuration of the present invention will be described. The piston13is an operating member of the present invention. The driver blade15is a striker of the present invention. The cylinder12is a guide member of the present invention. The holder23is a holder of the present invention. The vibration damping rubber133is a first buffer of the present invention. The vibration damping rubber53is a second buffer of the present invention. The opening11eis an opening of the present invention. The vibration damping rubber52is a third buffer of the present invention. The protruding portion48is a protruding portion of the present invention. The protruding portion21is a supporting portion of the present invention. The electric motor33is a motor of the present invention. The pin32is a pinion of the present invention. The rotary disc26is a rotary body of the present invention. The rotary disc26, the rack31, the reduction gear36, and the drive shaft27constitute a power conversion mechanism of the present invention. The top portion140is a first end portion of the present invention. The front end portion141is a second end portion of the present invention.

The driving machine of the present invention is not to be limited to the above embodiment and may be modified in various ways within a scope not deviating from the gist thereof. For example, the driving machine of the present invention may be a driving machine including a compression chamber formed in a bellows, an operating member fixed to an end portion of the bellows, and a cylinder supporting the operating member such that the operating member is movable. Furthermore, the driving machine of the present invention may have a structure in which the operating member is operated by elastic force of a spring. Examples of the spring include a metal spring. Furthermore, examples of the guide member of the present invention include, in addition to the cylinder, a linear rail guiding operation of the operating member, and a linear frame. Examples of the power conversion mechanism of the present invention for moving the operating member from the damper toward the compression chamber include a pulley and a wire in addition to a rack and pinion mechanism. That is, examples of the power conversion mechanism include a structure in which the operating member is operated by pulling force of the wire.

Furthermore, examples of the electric motor described in the embodiment include a DC motor (DC inverter motor) using a battery, which is a DC power supply, as a power source, and a motor (AC inverter motor) using an AC power supply. Furthermore, in lieu of the battery, an AC-DC converter converting an AC power supply to a DC power supply may be used to convert a commercial power supply (AC power supply) to a DC power supply and supply power to the DC motor (DC inverter motor) in the driving machine. Furthermore, as the motor, any of a hydraulic motor, a pneumatic motor, and an internal combustion engine may be used in lieu of the electric motor.

EXPLANATION OF REFERENCE CHARACTERS

10. . . driving machine,11. . . housing,11e. . . opening,12. . . cylinder,13. . . piston,15. . . driver blade,21,48. . . protruding portion,23. . . holder,25. . . damper,26. . . rotary disc,27. . . drive shaft,31. . . rack,32. . . pin,33. . . electric motor,36. . . reduction gear,45. . . compression chamber,52,53,133. . . vibration damping rubber,140,141. . . end portion, O1. . . center axis.