JP5122203B2 - Combustion type driving tool - Google Patents

Description

  The present invention relates to a combustion type driving tool that operates by burning a combustible gas.

In this type of driving tool, the upper chamber of a piston provided with a driver for hitting a driving tool such as a nail is used as a combustion chamber, and a combustible gas and air are supplied into the combustion chamber and agitated by rotation of a fan. The piston is shockedly lowered by the combustion pressure obtained by igniting with a spark plug and burning (explosion) to obtain impact force. Combustible gas is supplied by a cassette-type gas cylinder and ignited. By supplying power to the plug with a battery pack, its portability and handling are improved.
Conventionally, as a technique related to this type of combustion-type driving tool, for example, those disclosed in the following patent documents are known. These patent documents disclose various techniques for suppressing the impact or inertia at the time of combustion or striking applied to an electric motor for rotating a stirring fan and enhancing its durability. ing. For example, a technique is disclosed in which the electric motor is configured to absorb an impact by supporting the electric motor with a winding spring in a motor housing provided in the cylinder head.
JP 2005-288665 A JP 2005-329533 A JP 2006-281398 A

However, according to the conventional motor support structure using a winding spring, it is necessary to secure a storage space corresponding to a certain length during compression of the winding spring itself, and the shock absorption margin of the electric motor is limited in the limited motor storage portion. It is difficult to ensure a sufficient distance (the same is true hereinafter for the distance that the electric motor can move to absorb the shock), and in this respect, the conventional motor support structure has insufficient motor shock absorption.
The present invention has been made in view of the above-described conventional problems, and in a combustion type driving tool, when a support structure that absorbs an impact applied to a motor by using a winding spring is adopted, a large-sized motor housing portion is provided. The purpose of this invention is to further increase the durability of the motor by ensuring a larger shock absorption margin than the conventional one without incurring a reduction in cost.

Said subject is solved by each following invention.
1st invention is a combustion type driving tool provided with the electric motor for rotating the fan for stirring of the combustible gas supplied to the combustion chamber, Comprising: The accommodation part of an electric motor is provided. This is a driving tool configured to absorb a shock in the driving direction by interposing a frustoconical winding spring having a winding diameter that gradually changes between the wall portion and the electric motor .
According to the first aspect of the present invention , the electric motor is protected from the impact and the like by absorbing and mitigating the impact and the reaction generated when the combustible gas is burned or when the driving tool is driven. A conical spring having a truncated cone shape whose winding diameter gradually changes is used for this winding spring. For this reason, in the most compressed state, the wound spring is in a state of being compressed thinly to a width dimension substantially corresponding to the wire diameter (planar spiral state). On the other hand, when a cylindrical winding spring whose winding diameter does not change is used, an accommodation space having a width corresponding to the number of windings of the wire diameter is required even in the most compressed state. Therefore, by using the conical spring, it is possible to secure a larger shock absorption margin than before without increasing the motor accommodation space, thereby increasing the durability of the electric motor against impact or reaction than before. be able to.
A second invention is the driving tool according to the first invention, wherein a winding spring is interposed between the front and rear wall portions of the motor housing portion in the driving direction and the front portion and the rear portion of the electric motor .
According to the second invention , the impact or reaction is absorbed in both the driving direction and the counter driving direction, so that the electric motor can be protected more reliably.
A third invention is a driving tool according to the second invention, wherein a rear surface protection cap for protecting lead wires is attached to the rear portion of the electric motor, and a winding spring is applied to the rear portion of the electric motor via the rear surface protection cap. .
According to the third invention , the power supply lead wire is drawn out from the rear surface of the electric motor, and the lead wire lead portion is protected by the rear surface protection cap, so that the winding spring expands and contracts due to impact or the like. Even when the electric motor repeatedly moves, damage to the lead portion of the lead wire is prevented.
According to a fourth aspect , in the third aspect , the rear surface protective cap is fixed to the rear portion of the electric motor, and the rear surface protective cap is engaged with the motor housing portion so as to prevent the electric motor from rotating. It is a tool .
According to the fourth aspect of the invention , the rear surface protection cap can have both a lead wire protection function and an electric motor detent function.

Next, an embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows a combustion type driving tool 1 provided with a motor support structure according to the present embodiment. The driving tool 1 includes a main body 10 that includes a piston 2 and a cylinder 3, a handle 20 that extends from the side of the main body 10 to the side, a front end of the handle 20, and a front end of the main body 10. It has a magazine 30 equipped in a hanging state. In the following description, the driving direction of the driving tool will be described below with respect to the direction of each part and each member. In FIG. 1, the lower side is the driving direction.
A cylindrical cylinder 3 is fixed to the inner peripheral side of the main body case 11 of the main body 10. The piston 2 is supported on the inner peripheral side of the cylinder 3 so as to be able to reciprocate. A driving driver 4 is attached to the center of the lower surface of the piston 2. The driver 4 extends long downward from the center of the piston 2, and a tip portion thereof reaches the driver guide 5. The driver guide 5 guides the driver 4 in the driving direction, and is provided so as to extend downward from the lower end of the main body 10. The front end of the magazine 30 in the feed direction is coupled to the driver guide 5. The magazine 30 is loaded with a connected driving tool in which a number of driving tools are connected in parallel. The connecting driving tool loaded in the magazine 30 is pitch-fed to the driver guide 5 side in conjunction with the driving operation of the main body portion 10 through an interlocking mechanism (not shown), whereby the driving tool 1 is inserted into the driver guide 5. Supplied one by one. One supplied driving tool is hit by the driver 4 and driven from the tip of the driver guide 5.
The handle portion 20 is a part that is gripped by the user, and a switch lever 21 that is pulled by the user with a fingertip is disposed at a base portion thereof. When the switch lever 21 is pulled, the ignition switch 22 is turned on and a driving operation is performed. The configuration of the ignition switch 22 and its periphery will be described later.
A rechargeable battery pack 25 is attached to the tip of the handle portion 20. Using this battery pack 25 as a power source, an electric motor 45 for rotating a combustion chamber stirring fan 40 described below is started.

A cylindrical combustion chamber wall 6 is supported on the upper portion of the cylinder 3 so as to be movable up and down. A space portion defined by the cylinder head 7, the combustion chamber wall 6, the piston 2, and the cylinder 3 on the inner peripheral side of the combustion chamber wall 6 is defined as a combustion chamber F. When the combustion chamber wall 6 moves up, the combustion chamber F is closed in an airtight manner so that a combustible gas is supplied and combustion is performed. When the combustion chamber wall 6 moves downward, the combustion chamber F is opened and exhaust is performed.
The configuration around the combustion chamber F is shown enlarged in FIGS. A gas cylinder (not shown) filled with a combustible gas is mounted on the side of the combustion chamber F and between the combustion chamber wall 6 and the handle portion 20. As this gas cylinder, a cassette type that can easily replace a used one with a new one is used. The contact lever 9 provided along the driver guide 5 is brought into contact with the main body 10 by pressing the main body 10 in the driving direction (downward in FIG. 1) by bringing the tip of the driver guide 5 into contact with the driving portion of the driving material W. When the contact lever 9 is moved up relatively, the relative movement of the contact lever 9 causes the combustion chamber wall 6 to move up and the combustion chamber F to be closed in an airtight manner. A combustible gas is injected into the combustion chamber F. The basic configuration of the combustible gas supply mechanism is a conventionally known technique, and no particular change is required in the present embodiment.
The rear side of the cylinder head 7 is closed by a rear case 12 attached to the rear part of the main body case 11.
The combustible gas supplied into the combustion chamber F is mixed with air to obtain a mixture of a certain ratio. In order to efficiently generate this air-fuel mixture and increase the combustion efficiency during combustion, the combustion chamber F is provided with the above-described stirring fan 40. The fan 40 rotates using the electric motor 45 as a drive source. The electric motor 45 has a substantially columnar shape and is held in a cylindrical motor housing portion 8 provided in the cylinder head 7. An output shaft 45a of the electric motor 45 is protruded from the motor accommodating portion 8 into the combustion chamber F through an insertion hole 8b provided in the front wall 8a of the motor accommodating portion 8, and the fan 40 is inserted into the protruding portion. Is attached.
The electric motor 45 is supported in the motor housing 8 so as to be movable in the rotational axis direction (the axial direction of the output shaft 45a). A compression coil spring 46 is interposed between the front wall 8 a of the motor housing 8 and the front surface of the electric motor 45. The electric motor 45 is urged rearward (upward in FIG. 1) by the front compression coil spring 46. A retaining ring 47 for a hole is mounted on the inner periphery of the rear portion of the motor housing portion 8. A compression coil spring 48 is also interposed between the retaining ring 47 and the rear surface of the electric motor 45 (a rear surface protective cap 49 described later). This retaining ring 47 functions as the rear wall of the motor housing 8. The electric motor 45 is biased forward by the rear compression coil spring 48. By the front and rear compression coil springs 46 and 48, the electric motor 45 is supported in a floating state in which the electric motor 45 is elastically urged to both sides in the rotation axis direction in the motor housing 8.
Further, the electric motor 45 is supported by the side wall 8c of the motor housing portion 8 in a state where there is almost no backlash in the radial direction (the direction perpendicular to the rotation axis, the left-right direction in FIG. 1).

As described above, the electric motor 45 is supported in a floating state on both sides in the rotation axis direction, so that an impact at the time of combustion (explosion) or driving reaction is absorbed and is not directly transmitted to the electric motor 45. It has become.
Both compression coil springs 46 and 48 are frustoconical winding springs (so-called conical springs) whose winding diameters gradually change. Both the compression coil springs 46 and 48 correspond to the winding springs described in the claims.
For this reason, when both the compression coil springs 46 and 48 are compressed, the end portions 46b and 48b on the small diameter side sequentially enter the inner peripheral side of the end portions 46a and 48a on the large diameter side to form a planar spiral state. obtain. For this reason, both compression coil springs 46 and 48 can be finally compressed to a width dimension corresponding to the wire diameter. In this regard, in the case of a cylindrical compression coil spring in which the winding diameter does not change, even if it is compressed at the maximum, it is not compressed below the width dimension corresponding to the wire diameter × the number of turns. Therefore, the electric motor 45 can be moved in the motor housing portion 8 having the same size in the rotational axis direction by using the conical springs of the truncated cone shape as the front and rear compression coil springs 46 and 48 as described above. Therefore, the support structure of the electric motor 45 can have a larger shock absorption margin (shock absorption capability) than before without increasing the motor housing portion 8.
A large-diameter end 46 a of the front compression coil spring 46 is in contact with the front wall 8 a of the motor housing 8, and a small-diameter end 46 b is in contact with the front surface of the electric motor 45. The end 46a on the large-diameter side is in direct contact with the front wall 8a, and is in contact with the radial displacement by the side wall 8c. On the other hand, the end 46b on the small diameter side is a front surface of the electric motor 45 in a state in which the boss portion 45b provided on the front surface of the electric motor 45 is fitted to the inner peripheral side without any backlash and the displacement in the radial direction is restricted. It is in contact with. Thereby, the front side compression coil spring 46 is interposed in a state in which the positional deviation from the position that is concentric with the rotation axis of the electric motor 45 is restricted.
In addition, the end 48 a on the large diameter side of the compression coil spring 48 on the rear side is in contact with the retaining ring 47, and the end 48 b on the small diameter side indirectly contacts the rear surface of the electric motor 45 via the rear surface protective cap 49. It is touched. The end 48a on the large diameter side is in contact with the retaining ring 47 in a state in which the positional deviation in the radial direction is restricted by the side wall 8c, like the compression coil spring 46 on the front side. The small-diameter end 48b of the rear compression coil spring 48 is a state in which the boss 49a provided at the center of the rear surface protective cap 49 is fitted to the inner peripheral side without any backlash and the displacement in the radial direction is restricted. Thus, it is in indirect contact with the rear surface of the electric motor 45 via the rear surface protection cap 49. The front and rear compression coil springs 46 and 48 mounted in this way are arranged concentrically with respect to the rotation axis of the electric motor 45.

The rear surface protective cap 49 has an annular shape made of a synthetic resin and has an outer diameter substantially the same as the outer diameter of the electric motor 45, and is supported along the rear surface of the electric motor 45. Two lead wires 45c, 45c of the electric motor 45 are drawn out from the inner peripheral side of the rear surface protective cap 49. The inner peripheral side of the rear surface protective cap 49 is filled with a coating material 49b to prevent damage to both lead wires 45c and 45c.
The rear surface protective cap 49 is provided with an engaging portion 49c protruding to the outer peripheral side. The engaging portion 49 c is inserted into an engaging groove portion 8 d provided on the side wall 8 c of the motor support portion 8. The engagement groove 8d is formed long in a certain range in the rotation axis direction of the electric motor 45. For this reason, when the electric motor 45 moves in the direction of the rotation axis in the motor support portion 8, the rear surface protection cap 49 moves integrally therewith, so that the engaging portion 49c moves in the engaging groove portion 8d in the same direction. Moving.
An annular seal plate 45 d is attached to the output shaft 45 a of the electric motor 45. The seal plate 45d is held at a position that substantially contacts the boss portion 45b. Even when the air-fuel mixture in the combustion chamber F enters the motor support portion 8 through the insertion hole 8b of the front wall 8a by the seal plate 45d, this is shielded by the seal plate 45d and directly output shaft. Intrusion into the motor through the support portion 45a (boss portion 45b) is prevented.
Next, a spark plug 50 for generating a spark in the combustion chamber F is attached to the cylinder head 7. The structure of the spark plug 50 and its periphery is shown enlarged in FIGS. The spark plug 50 includes a plug anode 51 and a plug insulating part 52. The plug anode 51 is covered with a plug insulating part 52 except for its front end and rear part. The spark plug 50 is attached with the tip end portion of the plug anode 51 facing the combustion chamber F side by tightening the attachment screw portion 52a of the plug insulating portion 52 into the attachment screw hole 7a provided in the cylinder head 7.

The plug insulating part 52 of the present embodiment is integrally molded using a resin molding material having high dielectric strength. Specifically, a thermoplastic engineering plastic, such as PPS resin (polyphenylene sulfide), whose dielectric strength is low in temperature dependency is used as a material. Alternatively, PBT resin (polybutylene terephthalate) may be used. Conventionally, the dielectric strength (insulation breakdown strength, voltage that the insulation material can withstand) of plug insulation parts made of nylon resin is usually reduced to about 10 kV / mm at around 100 ° C, but these thermoplastic engineering plastics are used as materials. As a result, it is possible to ensure a dielectric strength of at least about 12 kV / mm at 100 ° C., thereby greatly suppressing current leakage even at high temperatures as compared with the prior art. It is possible to surely spark between the front end of 53.
Further, the creepage distance B (corresponding to the radius of the mounting screw portion 52a of the plug insulating portion 52) shown in FIG. 5 is at least one of the gap (gap, dimension A in FIG. 5) between the plug anode 51 and the plug cathode 53. .5 times (more than 1.5 times the plug gap). As described above, the plug anode 51 is also set by setting the diameter of the plug insulating portion 51 (mainly the screw diameter of the mounting screw portion 52a) with reference to the gap (plug gap) between the plug anode 51 and the plug cathode 53. The spark is surely generated by the discharge between the front end portion and the plug cathode 53, so that the ignition of the combustible gas is ensured.
Conventionally, the material of the plug insulation part is nylon or the wall thickness is not sufficiently thick, so that the insulation resistance of the plug insulation part is insufficient, and current leakage at the plug insulation part occurs at high temperatures. As a result, a sufficient discharge is not generated between the tip of the plug anode and the plug cathode, resulting in an ignition error, and thus a defective driving operation may occur. In this regard, as described above, the plug insulating portion 52 is formed using PPS resin as a material, and the creeping distance B (corresponding to the radius of the mounting screw portion 52a of the plug insulating portion 52) is at least 1.5 times the plug gap A. Therefore, the current leakage of the plug insulating portion 52 is suppressed, and a spark is reliably generated between the tip end portion of the plug anode 51 and the plug cathode 53, thereby reliably igniting the combustible gas. Can be done.
The plug cathode 53 is provided integrally with the cylinder head 7 using aluminum as a material.

Next, a fan switch 15 is disposed on the side of the combustion chamber wall 6, and an ignition switch 22 is disposed near the base of the handle portion 20. The configuration of the fan switch 15 and its surroundings is shown enlarged in FIG. 7, and the configuration of the ignition switch 22 and its surroundings is shown enlarged in FIG.
Both switches 15 and 22 are known microswitches. The switches 15 and 22 are respectively provided with main body portions 15a and 22a, operating buttons 15b and 22b provided on the side portions of the main body portions 15a and 22a, and moving between an on position and an off position, and the main body portions 15a and 15a, Actuating levers 15c and 22c are provided on the side of 22a so as to be tiltable and tilt between an on position and an off position. When the actuating levers 15c and 22c are tilted to the on position, the actuating buttons 15b and 22b are pushed into the switch body portions 15a and 22a. When the switch bodies 15a and 22a are turned on, an on signal is output to the control circuit via the wirings 15d and 22d.
When the contact lever 9 is turned on, the gas cylinder is opened by a conventionally known mechanical means (not shown) and a certain amount of combustible gas is supplied into the combustion chamber F, and the fan switch 15 is turned on in conjunction with this. As a result, the electric motor 45 is activated and the fan 40 starts to rotate. On the other hand, when the ignition switch 22 is turned on, the combustible gas in the combustion chamber F is ignited by the spark of the spark plug 50, so that the piston 2 is moved downward to perform the driving operation.
As described above, the contact lever 9 is provided along the driver guide 5 so as to be relatively movable up and down. When the front end of the contact lever 9 is brought into contact with the driving material and the main body portion 10 is pressed in the driving direction, the contact lever 9 relatively moves upward.
The contact lever 9 is connected to the combustion chamber wall 6 via a connection lever (not shown). For this reason, when the contact lever 9 moves up (turns on) relative to the main body 10, the combustion chamber wall 6 moves up to close the gap between the cylinder head 7 and the combustion chamber. F is hermetically closed. On the other hand, when the pressing operation of the main body portion 10 is released, the contact lever 9 relatively moves down (turns off). When the contact lever 9 is moved down to the off position, the tip end of the contact lever 9 protrudes below the tip end of the driver guide 5 by a certain dimension, and the combustion chamber wall 6 moves down to open the combustion chamber F. It is.

When the combustion chamber wall 6 moves up by closing the contact lever 9 and the combustion chamber F is closed, the fan switch 15 is turned on. An annular seal body 6 a that is airtightly closed by being pressed by the cylinder head 7 is attached to the upper portion of the combustion chamber wall 6 over the entire circumference. The fan switch 15 is disposed on the side of the seal body 6a.
When the seal body 6a is moved up integrally with the combustion chamber wall 6 by the ON operation of the contact lever 9, the operating lever 15c of the fan switch 15 is pushed to the ON position side (right side in FIG. 7) and tilted, thereby operating. The button 15b is pushed into the on position and the fan switch 15 is turned on. On the contrary, when the seal body 6a is moved downward together with the combustion chamber wall 6 by the turning-off operation of the contact lever 9, the seal body 6a is retracted downward from the side of the operation lever 15c. When the seal body 6a is retracted from the side, the operating lever 15c is returned to the off position by the urging force of the operating button 15b, so that the operating button 15b returns to the off position and the fan switch 15 is turned off.
Thus, the moving direction (on / off operating direction) of the operating lever 15c and the operating button 15b of the fan switch 15 intersects at an angle close to or close to the moving direction of the seal body 6a (driving tool driving direction). The mounting posture (direction) of the fan switch 15 is set so as to be in the direction. For this reason, the impact in the vertical direction when the contact lever 9 is turned on and off is not directly applied to the operation button 15b and the switch body 15a via the operation lever 15c, thereby improving the durability of the fan switch 15. Can do.

On the other hand, as shown in FIG. 8, an operating lever portion 21 a is provided above the switch lever 21 so as to protrude upward. An ignition switch 22 is arranged on the side (right side in FIG. 8) of the operating lever portion 21a.
When the user pulls the switch lever 21 upward with a fingertip, the operating lever portion 21a moves upward together with the switch lever 21. When the actuating lever 21a moves upward, the actuating lever 22c of the ignition switch 22 located on the side of the actuating lever 21a is pushed and tilted to the on position side (right side in FIG. 8), thereby pushing the actuating button 22b to the on position. The ignition switch 22 is turned on. On the contrary, when the pulling operation of the switch lever 21 is released, the switch lever 21 is returned to the lower OFF position by the biasing force of the compression spring (not shown). When the switch lever 21 is returned to the OFF position, the operating lever portion 21a moves downward integrally with the switch lever 21 and retracts from the side of the operating lever 22c of the ignition switch 22. For this reason, the operation lever 22c is returned to the off position by the urging force of the operation button 22b, so that the operation button 22b returns to the off position and the ignition switch 22 is turned off.
In this way, the ignition switch 22 is in a direction in which the movement direction (on / off operation direction) of the operation lever 22c and the operation button 22b is orthogonal or intersects at an angle close to the operation direction of the switch lever 21. 22 mounting postures (directions) are set. Therefore, the impact in the vertical direction when the switch lever 21 is turned on / off is not directly applied to the operation button 22b and the switch body 22a via the operation lever 22c, thereby improving the durability of the ignition switch 22. Can do.
As described above, in the driving tool 1 according to the present embodiment, the on / off operation directions of the fan switch 15 and the ignition switch 22 are orthogonal or intersecting with the moving directions of the contact lever 9 and the switch lever 21 that are moved during the driving operation. Therefore, the fan switch 15 and the ignition switch 22 can be protected against an impact generated by the operation.

A restriction bar 23 is provided on the switch lever 21. The restriction bar 23 is supported on the side of the switch lever 21 so as to be rotatable up and down. The restriction bar 23 is inserted through a guide hole 11 a provided in the main body case 11. In the guide hole 11a, the regulation bar 23 is inserted not only in the longitudinal direction but also in the lateral direction so as to be displaceable within a certain range. The front end side of the regulation bar 23 reaches the side portion of the combustion chamber wall 6 through the insertion hole 11 b of the main body case 11.
A restricting plate 16 is attached to the side of the combustion chamber wall 6 at a position facing the tip of the restricting bar 23, and an escape hole 6b is provided.
When the switch lever 21 is pulled upward in the state where the contact lever 9 is turned on and the combustion chamber wall 6 is moved upward, the regulating bar 23 is displaced obliquely upward in the longitudinal direction, and the leading end thereof is moved to the regulating plate. It will be in the state made to approach into the escape hole 6b through 16 below. For this reason, in this state, the downward movement of the combustion chamber wall 6 is restricted, so that the combustion chamber F is kept airtightly closed.
On the other hand, in a state where the contact lever 9 is not turned on (off state) and the combustion chamber wall 6 is opened, the restriction plate 16 is located at a position opposite to the restriction bar 23. 23 is restricted from moving diagonally upward, so that the switch lever 21 cannot be pulled. Accordingly, as a driving operation procedure of the driving machine 1, the driving operation is performed by pulling the switch lever 21 after the contact lever 9 is turned on, and the driving operation is not performed in the reverse operation order. Incorrect operation is prevented.

  According to the driving tool 1 according to the present embodiment configured as described above, the front and rear compression coil springs 46 and 48 expand and contract due to impact or reaction when the driving tool is driven or when combustible gas is burned (explosion). Is absorbed. As the front and rear compression coil springs 46 and 48, conical springs having a truncated cone shape whose winding diameter gradually changes are used. For this reason, both the compression coil springs 46 and 48 can be compressed to the width corresponding to the wire diameter in the most compressed state. On the other hand, in the case of a conventional configuration using a cylindrical winding spring in which the winding diameter does not change for both compression coil springs, the number of turns of the wire diameter in the most compressed state (wire diameter x number of turns) It is compressed only to the width dimension corresponding to. From this, by using conical springs for the front and rear compression coil springs 46 and 48, without increasing the accommodation space in the motor axial direction of the motor accommodating portion 8 (interval between the front wall 8a and the retaining ring 47), A larger shock absorption allowance (distance that the electric motor 45 can move) than before can be ensured, and thus the electric motor 45 can be more reliably protected against the shock.

Various modifications can be made to the embodiment described above. For example, although the configuration using the conical springs 46 and 48 before and after the electric motor 45 is illustrated, a configuration using a normal compression coil spring which is used only for one side and the winding diameter does not change may be used for the other side. Even with such a configuration, it is possible to ensure a larger shock absorption margin than a configuration using a normal compression coil spring in which the winding diameter does not change both in the front and rear directions.
Moreover, although the structure which uses a compression spring as a winding spring was illustrated, it is good also as a structure which uses a tension coil spring. Even in such a configuration, the electric motor 45 is supported in a floating manner in the direction in which the impact is applied, and a larger shock absorption allowance can be ensured than in the past.
The filling of the coating material 49b into the inner peripheral hole of the rear surface protective cap 49 may be omitted. Even if the filling of the coating material 49 b is omitted, the lead-out portions of the lead wires 45 c and 45 c are protected by the rear surface protective cap 49.

It is a longitudinal section of the whole combustion type driving tool concerning this embodiment. It is a longitudinal cross-sectional view of a cylinder head. This figure has shown the state which the electric motor moved below in the motor accommodating part. It is a longitudinal cross-sectional view of a cylinder head. This figure has shown the state which the electric motor moved upwards in the motor accommodating part. It is the top view which looked at the cylinder head from the arrow (4) direction in FIG. It is a longitudinal cross-sectional view of a spark plug and its periphery. It is the top view which looked at the ignition plug and its periphery from the arrow (6) direction in FIG. It is a side view of a fan switch and its periphery. In this figure, the operating lever in the off position is indicated by a solid line, and the operating lever in a state of being moved to the on position is indicated by a two-dot chain line. It is a side view of an ignition switch and its periphery. In this figure, the operating lever in the off position is indicated by a solid line, and the operating lever in a state of being moved to the on position is indicated by a two-dot chain line.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Driving tool 2 ... Piston 3 ... Cylinder 4 ... Driver 5 ... Driver guide 6 ... Combustion chamber wall, 6a ... Sealing body, 6b ... Relief hole F ... Combustion chamber 7 ... Cylinder head 8 ... Motor accommodating part 8a ... Front wall, 8b ... insertion hole, 8c ... side wall, 8d ... engagement groove 9 ... contact lever 10 ... main body part 11 ... main body case, 11a ... guide hole, 11b ... insertion hole 12 ... rear case 15 ... fan switch 15a ... switch main body, 15b Operation button, 15c ... Operation lever, 15d ... Wiring 20 ... Handle portion 21 ... Switch lever 22 ... Ignition switch 22a ... Switch body, 22b ... Operation button, 22c ... Operation lever, 22d ... Wiring 23 ... Restriction bar 25 ... Battery pack 30 ... Magazine 40 ... Fan 45 ... Electric motor 45a ... Output shaft 45b ... Boss part 45c ... Lead wire 45d ... 46a ... large diameter side end, 46b ... small diameter side end 47 ... retaining ring 48 ... compression coil spring (rear side), 48a ... large diameter side end, 48b ... End on the small diameter side 49 ... Rear surface protection cap, 49a ... Boss part, 49b ... Coating material, 49c ... Engagement part 50 ... Spark plug 51 ... Plug anode 52 ... Plug insulation part, 52a ... Mounting screw part 53 ... Plug cathode

Claims (4)

A combustion type driving tool provided with an electric motor for rotating a fan for stirring a combustible gas supplied to a combustion chamber, the electric motor being movable in a rotation axis direction and supported in a floating manner in a motor housing portion. in which, between the front and rear of the driving direction front and rear wall portion and the electric motor of the motor housing portion, the impact of the winding diameter driving direction with intervening coil spring frustoconical gradually changing Driving tool designed to absorb. 2. The driving tool according to claim 1, wherein the large-diameter side end portions of the front and rear winding springs are respectively brought into contact with the motor housing portion side, and the small-diameter side end portions are respectively fitted to the boss portions on the electric motor side. In addition, the driving tool is arranged in a state where the front and rear winding springs are concentric with each other and the positional deviation in the radial direction is restricted . The driving tool according to claim 1 or 2, wherein a rear surface protection cap for protecting lead wires is attached to a rear portion of the electric motor, and a winding spring is applied to the rear portion of the electric motor via the rear surface protection cap. tool. The driving tool according to claim 3, wherein the rear surface protection cap is fixed to a rear portion of the electric motor, and the rear surface protection cap is engaged with the motor housing portion in an uneven manner to prevent rotation of the electric motor. A driving tool.

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