JP4985221B2 - Combustion type driving machine - Google Patents

Description

  In the present invention, a liquefied gas filled in a gas cylinder is injected into a combustion chamber, and an air-fuel mixture formed by mixing the liquefied gas with air is ignited and burned to generate power for driving a piston. The present invention relates to a combustion type driving machine for driving a fastener such as a nail.

  In this type of combustion type driving machine, the mixed gas containing the fuel injected into the combustion chamber is burned, and the volume expansion of the mixed gas is converted into the driving force of the piston. In order to improve the combustion performance of the air-fuel mixture in the combustion chamber, a fan is provided in the combustion chamber, and fuel and air are uniformly stirred by the rotation of the fan.

  Thus, the fan is driven to rotate by a motor, and this fan generates turbulent flow in the combustion chamber to promote the combustion of the air-fuel mixture, and converts the volume expansion due to explosive combustion into the driving force of the piston in the combustion chamber. Then, a fastener such as a nail is driven by the piston. At this time, the combustion gas in the lower chamber of the piston in the cylinder passes through the exhaust hole below the cylinder and the gap between the driver blade and the cylinder as the piston descends, and is discharged from the exhaust port provided in the housing to the atmosphere. The

  In addition, after combustion of the air-fuel mixture, the fan continues to rotate in order to discharge the combustion gas from the cylinder to the outside of the main body, new air is introduced from the upper part of the main body, and the combustion gas is discharged from the exhaust hole formed below the cylinder. It discharges and scavenging in a cylinder is performed.

  Here, a conventional example of a combustion type nailing machine as one form of such a combustion type driving machine will be described with reference to FIGS.

  4 is a cutaway side view of the combustion type nailer, FIG. 5 is a side view of the combustion type nailing machine, FIG. 6 is a perspective view of a dustproof cover alone, and FIG. 7 is a front view of the combustion nailing machine (FIG. 5). 8 is a plan view of the combustion type nailing machine, and FIG. 9 is a plan view of the combustion type nailing machine with the head cover and head protector removed. In FIG. 9, the handle portion is not shown, and FIG. 9 shows a state where no gas cylinder is attached. In the following description, the nail driving direction is the lower side, and the opposite direction is the upper side.

  The illustrated combustion nailing machine 1 ′ has a housing 2 constituting an outer frame, and a flange portion 2 a is formed below the housing 2. The flange portion 2 a is made of an elastic material. 6, the periphery of the upper end opening of the dust cover 55 molded as shown in FIG. And the dustproof cover 55 is attached to the housing 2 by screws 58 shown in FIG.

  A head cover 3 having an intake port 3 a is attached to the upper portion of the housing 2, and a handle 4 is integrally extended from the side portion of the housing 2. The handle 4 is provided with a trigger switch 5 and a battery 4a is detachably attached thereto. Further, a cylinder chamber 17 is formed inside the handle 4, and a gas cylinder 30 filled with a combustible liquefied gas is detachably accommodated in the cylinder chamber 17. A magazine 6 loaded with nails (not shown) is provided below the handle 4.

  A nose 7 extends from the vicinity of the lower end of the housing 2, and the nose 7 is integrally formed with a cylinder 20 described later, and a tip portion thereof faces the driven material 28. The nose 7 guides the sliding of a driver blade 23a, which will be described later, and the driving of a not-shown nail into the driven material 28. At the lower end 7a of the nose 7, a push lever 9 that abuts against the workpiece 28 is protruded and supported so as to be reciprocally slidable, and the upper end of the push lever 9 is fixed to a combustion chamber frame 10 described later. Are connected to the arm portion 8 shown in FIG. A spring 22 as a biasing member is mounted between the arm portion 8 and the cylinder 20, and the push lever 9 connected to the arm portion 8 is biased downward by the spring 22.

  A cylinder head 11 that covers the upper end opening of the housing 2 is fixed to the upper end of the housing 2. As shown in FIG. 4, a motor 18 is disposed on the opposite side of the combustion chamber 26 of the cylinder head 11, and in the vicinity of the motor 18, the ignition position faces the combustion chamber 26 as shown in FIG. 9. A spark plug 12 is provided.

  A cylindrical motor holding cylinder 13 is elastically supported on the cylinder head 11, and the motor 18 is accommodated and held in the holding cylinder 13. Inside the housing 2, a switch 33 for detecting that the combustion type nailing machine 1 'is pressed against the driven material 28 and the combustion chamber frame 10 is at the upper end of stroke (top dead center). When the push lever 9 is raised to a predetermined position, the switch 33 is turned on and the rotation of the motor 18 is started.

  A fuel passage 25 is formed in the handle 4 side of the cylinder head 11, one end of the fuel passage 25 opens at the lower end surface of the cylinder head 11, and the other end has a gas cylinder connecting portion 25 a connected to the gas cylinder 30. Forming.

  Inside the housing 2, a combustion chamber frame 10 is provided that is movable in the longitudinal direction of the housing 2 and whose upper end can contact the lower end surface of the cylinder head 11. The combustion chamber frame 10 includes a chamber 10a and a chamber head 10b, and is integrally coupled by a bolt or the like (not shown). Since the arm portion 8 is connected and fixed to the combustion chamber frame 10, the combustion chamber frame 10 also moves as the push lever 9 moves.

  Further, a cylinder 20 that contacts the inner peripheral surface of the combustion chamber frame 10 and guides the movement of the combustion chamber frame 10 is fixed in the housing 2, and a plurality of cylinders 20 are disposed in the vicinity of the central portion in the axial direction of the cylinder 20. The exhaust holes 21 are formed, and check valves (not shown) are provided in these exhaust holes 21 so as to selectively close the exhaust holes 21.

  A piston 23 slidable with respect to the cylinder 20 is fitted in the cylinder 20, and the piston 23 defines the inside of the cylinder 20 as a piston upper chamber and a piston lower chamber. A driver blade 23a extends from the lower surface of the piston 23 to the position of the nose 7, and the tip of the driver blade 23a hits a nail (not shown). A bumper 24 made of an elastic material such as rubber is disposed in the lower part of the cylinder 20. Therefore, when the piston 23 moves downward, the piston 13 collides with the bumper 24 at the bottom dead center. At this time, the air below the piston 23 in the cylinder 20 is discharged from the exhaust hole 21 and is discharged out of the housing 2 through a discharge port (not shown) formed below the housing 2.

  Thus, when the upper end of the combustion chamber frame 10 comes into contact with the cylinder head 11, the combustion chamber 26 is defined by the cylinder head 11, the combustion chamber frame 10, and the upper surface of the piston 23. When the combustion chamber frame 10 is separated from the cylinder head 11, a flow path communicating with outside air is formed between the cylinder head 11 and the upper end of the combustion chamber frame 10, and the inner periphery of the combustion chamber frame 10 and the outer periphery of the cylinder 20 are Another flow path is formed between the two. These passages allow combustion gas and fresh air to pass through the outer peripheral surface side of the cylinder 20, and the passed combustion gas and the like are discharged from the exhaust port of the housing 2. The intake port 3a is formed to supply fresh air into the combustion chamber 26. A filter 16 is installed in the vicinity of the intake port 3a, and the combustion in the combustion chamber 26 is performed from the exhaust hole 21. Gas is exhausted.

  The output shaft of the motor 18 faces the combustion chamber 26, and a fan 19 is attached to the lower end thereof. When the fan 19 is rotationally driven by the motor 18, the air and the combustible gas are stirred and mixed in the combustion chamber 26 formed by the combustion chamber frame 10 coming into contact with the cylinder head 11, and an air-fuel mixture is formed. A turbulent flow is generated in the air-fuel mixture and the combustion is promoted. When the combustion chamber frame 10 is separated from the cylinder head 11, the combustion gas in the combustion chamber 26 is scavenged and the cylinder 20 is cooled.

  Next, the operation of the combustion nailing machine 1 'configured as described above will be described with reference to FIG.

  In the non-operating state, the push lever 9 is urged downward by the urging force of the spring 22 and protrudes from the lower end of the nose 7. At this time, since the combustion chamber frame 10 is connected to the push lever 9 via the arm portion 8, the upper end of the combustion chamber frame 10 is separated from the cylinder head 11 and defines the combustion chamber 26 of the combustion chamber frame 10. The portion and the upper end portion of the cylinder 20 are separated from each other. At this time, the piston 23 is stopped at the top dead center position in the cylinder 20.

  When the handle 4 is grasped and the push lever 9 is pressed against the driven material 28 in the above state, the push lever 9 rises against the urging force of the spring 22, and the push lever 9 The connected combustion chamber frame 10 is also raised and the combustion chamber 26 is sealed.

  Further, as the push lever 9 moves, the gas cylinder 30 is tilted toward the cylinder head 11, and the injection rod of the gas cylinder 30 is pressed against the gas cylinder connection portion 25 a of the cylinder head 11, and the combustibility in the gas cylinder 30 is brought into the combustion chamber 26. The liquefied gas is injected only once from the injection port of the fuel passage 25.

  Further, when the combustion chamber frame 10 rises to the stroke end with the movement of the push lever 9, the switch 33 is turned on to supply power to the motor 18, the motor 18 is activated, and the fan 19 starts rotating. Thus, the fan 19 rotates in the combustion chamber 26 which has become a sealed space, so that the injected combustible gas is stirred and mixed with the air in the combustion chamber 26.

  When the trigger switch 5 of the handle 4 is turned on in the above state, the spark plug 12 sparks, and the air-fuel mixture is ignited and combusted and expanded. The combustion / expanded air-fuel mixture moves the piston 23 downward, and the nail in the nose 7 is driven into the driven material 28 by the driver blade 23a until the piston 23 abuts against the bumper 24 at the bottom of the cylinder 20.

  After the nail is driven into the driven material 28, the piston 23 comes into contact with the bumper 24 and stops, and the combustion gas is discharged from the exhaust hole 21 to the outside of the cylinder 20. The combustion gas collides with the inner wall of the dust cover 55 and changes its direction, and is discharged from the opening 54 formed in the dust cover 55 to the outside of the housing 2.

  As described above, a check valve (not shown) is attached to the exhaust hole 21, and the combustion gas is discharged to the outside of the cylinder 20. When the inside of the cylinder 20 and the combustion chamber 26 becomes atmospheric pressure, the reverse is performed. The stop valve is closed.

  The combustion gas remaining in the cylinder 20 and the combustion chamber 26 is at a high temperature because it is after combustion, and the combustion heat is absorbed from the inner wall of the cylinder 20 and the inner wall of the combustion chamber frame 10, so that the cylinder 20 and the like become high temperature. . The absorbed heat is dissipated into the atmosphere from the cylinder 20 and the outer wall surface of the combustion chamber frame 10.

  As described above, when the combustion heat of the combustion gas is absorbed by the cylinder 20 or the like, the combustion gas is rapidly cooled and its volume is reduced, so that the pressure in the closed space above the piston 23 is reduced to below atmospheric pressure. (Thermal vacuum), the piston 23 is pulled back to the initial top dead center position.

  After that, when the trigger switch 5 is turned off to lift the main body and the push lever 9 is separated from the driven material 28, the push lever 9 and the combustion chamber frame 10 are returned downward by the urging force of the spring 22. At this time, the fan 19 continues to rotate by a control unit (not shown) even if the trigger switch 5 is turned off.

  In the state shown in FIG. 4, a flow path is formed above the combustion chamber frame 10, and clean air is taken in from the intake port 3 a provided in the head cover 3 through the filter 16 by generating a flow by the rotation of the fan 19. Then, the air in the combustion chamber 26 is scavenged by discharging the air after combustion from the exhaust port at the lower end of the housing 2. Thereafter, the rotation of the fan 19 is stopped and the initial stationary state shown in FIG. 4 is obtained. It becomes possible to drive the nail again by repeating the above process again after the stationary state.

By the way, this type of combustion nailing machine 1 ′ is often used in places with a lot of dust such as outdoors, and is formed below the housing 2 in order to suppress the penetration of dust into the housing 2. A dustproof cover 55 made of an elastic material is attached so as to cover the through-hole and the exhaust port (see Patent Document 1).
Japanese Patent Laid-Open No. 2005-001110

  Thus, in a normal state, the dust-proof cover 255 is attached in close contact with the housing 202 as shown in FIG. 10, but the dust-proof cover 255 is exposed to combustion gas of hundreds of degrees during operation and is heated. As a result, as shown in FIG. 11, a gap 259 is generated between the dust cover 255 and the housing 202, and dust enters the housing 202 from the gap 259. Also, when the thermal expansion of the dustproof cover 255 progresses by hitting the nail continuously, in the worst case, the dustproof cover 255 is dropped from the housing 202 or even if the dustproof cover 255 is cooled, it is restored to its original shape. Sometimes it disappeared.

  Inside the housing of the combustion type nailer, there is a seal part for forming or opening a combustion chamber and an ignition plug for ignition, and if dust enters the inside of the housing, the nailing machine will fail due to poor sealing or poor ignition. There was a problem that stopped working.

  Therefore, conventionally, dust that has entered the inside of the housing has been removed by disassembling and cleaning the nailing machine, but the work is difficult and troublesome.

  The present invention has been made in view of the above problems, and the object of the present invention is to improve the adhesion of the dust-proof cover to the housing with a simple configuration and ensure high dust-proof performance even under severe usage conditions. An object of the present invention is to provide a combustion type driving machine capable of reliably preventing dust from entering inside.

In order to achieve the above object, the present invention according to claim 1 includes a housing, a cylinder head provided at one end of the housing, a combustion chamber frame that forms a combustion chamber together with the cylinder head,
A motor supported by the cylinder head; a fan for stirring the combustion gas and air in the combustion chamber in the combustion chamber by the motor; and exhaust of a mixed gas of the combustion gas and air provided at the other end of the housing And a dust-proof cover having an opening serving as a mouth, wherein at least a part of the dust-proof cover covers the outer periphery of the housing, and the cover of the dust-proof cover is separated from the housing. The present invention is characterized in that a deformation suppressing means for suppressing deformation is provided.

  According to a second aspect of the present invention, in the first aspect of the present invention, the deformation suppressing means is provided on an outer periphery of the covering portion.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, the deformation suppressing means is a linear steel material.

  According to a fourth aspect of the present invention, in the third aspect of the present invention, the steel material is formed integrally with the dustproof cover.

  The invention according to claim 5 is the invention according to claim 3, wherein a groove is provided on the outer peripheral side of the dust cover, and the steel material is fitted into the groove.

  The invention according to claim 6 is the invention according to any one of claims 1 to 5, wherein the dust-proof cover has a curved shape such that a lower end side thereof is tapered with respect to the covering portion. And

  The invention according to claim 7 is the invention according to any one of claims 1 to 6, characterized in that the dustproof cover has a lower end portion smaller in diameter than the inner diameter on the other end side of the housing.

  The invention according to claim 8 is the invention according to any one of claims 1 to 7, wherein the dustproof cover has an outer wall portion and a tip portion extending from the outer wall portion, and the tip portion is a longitudinal direction of the housing. It extends in the direction substantially orthogonal to.

  According to the first aspect of the present invention, since the deformation suppressing means for suppressing the dust cover from being deformed by the heat of the mixed gas is provided, the adhesion between the dust cover and the housing is improved, and a higher dustproof effect is obtained. Can do.

  According to the second aspect of the present invention, since the deformation suppressing means is provided in the portion covering the housing, the adhesion between the dust-proof cover and the housing is further improved, and a higher dust-proof effect can be obtained.

  According to the invention described in claim 3, since the deformation suppressing means is made of steel, the adhesion between the dustproof cover and the housing can be improved with a simple configuration.

  According to the invention described in claim 4, since the steel material is integrally formed with the dust cover, the number of parts can be reduced, and the adhesion between the dust cover and the housing can be improved with a simple configuration. Can be easily attached to the housing.

  According to the fifth aspect of the present invention, since the steel material is fitted into the groove of the dust-proof cover, the steel material can be properly positioned, and the positional deviation of the steel material can be prevented. Adhesion with can be further increased.

  According to the sixth aspect of the invention, since the dust cover is tapered from the covering portion toward the lower end side, deformation on the other end side can be suppressed.

  According to the seventh aspect of the present invention, since the lower end portion of the dustproof cover is smaller than the inner diameter of the housing, the dustproofness from the lower end portion of the dustproof cover to the inside of the housing can be improved.

  According to the eighth aspect of the present invention, since the tip of the dustproof cover has a shape substantially orthogonal to the housing, the dustproofness from the lower end side of the dustproof cover to the inside of the housing can be improved, and the lower end side of the dustproof cover Can be suppressed.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

<Embodiment 1>
1 is a side view of a combustion nailing machine according to Embodiment 1 of the present invention, and FIG. 2 is a cross-sectional view taken along line AA of FIG. 1, in which these figures are shown in FIGS. The same elements are denoted by the same reference numerals, and description thereof will be omitted below.

  The basic configuration and operation of the combustion type nailing machine 1 according to the present embodiment are the same as those of the conventional combustion type nailing machine 1 ′ shown in FIGS. As shown in FIG. 2, a linear steel material 56 is integrally inserted into the periphery of the upper end opening that is a fitting portion of the dust-proof cover 55 into the flange portion 2a of the housing 2, and the dust-proof cover 55 is inserted into the flange of the housing 2 by the steel material 56. It is characterized by being fixed by crimping to the outer periphery of the portion 2a.

  Here, the dustproof cover 55 is molded by an elastic material such as an elastomer which is a polymer material. At the time of molding, the steel material 56 is set in the mold in advance, and a molten liquid elastic material is poured into the mold. Thus, the steel material 56 is integrally inserted into the dustproof cover 55. In the present embodiment, the dust-proof cover 55 is formed so as to be smaller than the outer peripheral shape of the flange portion 2a of the housing 2 when it is a single unit. It is fitted to the outer periphery of the portion 2 a, is closely fixed to the housing 2 by the elastic force of the linear steel material 56, and two left and right portions thereof are fixed to the housing 2 by screws 58.

  In the present embodiment, a piano wire having a wire diameter of about φ2 mm to φ3 mm is used as the linear steel material 56, and the dustproof cover 55 is formed in a substantially U shape so that it adheres to the housing 2 by the elastic force of the piano wire itself. Has been. Specifically, the piano wire 56 has a shape smaller than the cross-sectional shape of the flange portion 2 a of the housing 2, and is fitted to the outer periphery of the flange portion 2 a of the housing 2 while widening the periphery of the upper end opening of the dust cover 55.

  Thus, when the nailing operation is performed using the combustion nailing machine 1, the high-temperature combustion gas discharged from the exhaust port of the housing 2 of the combustion nailing machine 1 is removed from the inner wall of the dust-proof cover 55. Therefore, the dust cover 55 is thermally expanded.

  However, in the present embodiment, the steel material 56 that is integrally inserted into the dust cover 55 suppresses thermal deformation of the dust cover 55, and does not come into close contact with the housing 2 to generate a gap therebetween. Thus, even if the dustproof cover 55 is thermally expanded, the adhesion of the dustproof cover 55 to the housing 2 is enhanced with a simple configuration, so that high dustproof performance is ensured even under severe usage conditions such as continuous hitting. Intrusion of dust into the housing 2 is reliably prevented. In the present embodiment, since the steel material 56 is integrally inserted into the dust cover 55, the number of parts is reduced and the dust cover 55 can be easily assembled to the housing 2 with good workability.

  In addition, although arbitrary things can be used as the linear steel material 56, the thing of a material with a high elastic force is preferable. Further, the cross-sectional shape of the steel material 56 is arbitrary, and for example, a plate shape can be used. Furthermore, the material of the dust cover 55 is also arbitrary, and more general rubber can be used.

<Embodiment 2>
Next, a second embodiment of the present invention will be described with reference to FIG.

  FIG. 3 is a side view of a combustion chamber nailing machine according to Embodiment 2 of the present invention. In this figure, the same elements as those shown in FIG. Will not be described again.

  This embodiment is characterized in that the peripheral edge of the opening of the dustproof cover 55 is closely fixed to the housing 2 from the outside with a linear steel material 56 which is a separate member. Here, a groove 57 is formed on the outer periphery of the upper end opening portion, which is a fitting portion of the dust cover 55 on the outer periphery of the flange portion 2a of the housing 2, and a linear steel material 56 is fitted and positioned in the groove 57. .

  Therefore, also in the present embodiment, the thermal expansion of the dustproof cover 55 can be suppressed and the adhesion of the dustproof cover 55 to the housing 2 can be improved with a simple configuration as in the first embodiment. Even under severe use conditions such as these, high dustproof performance is ensured and dust can be reliably prevented from entering the housing 2. And in this Embodiment, if only the linear steel material 56 is added, since the existing dustproof cover 55 can be used, high dustproof performance can be ensured, suppressing cost.

  Further, in the present embodiment, since the linear steel material 56 is fitted into the groove 57 formed on the outer periphery of the dustproof cover 55, the steel material 56 is accurately positioned to improve the adhesion of the dustproof cover 55 to the housing 2. . For this reason, deviation of the steel material 56 is prevented, and the dust-proof cover 55 can be securely fixed to the housing 2 by the steel material 56 with good workability, and high dust-proof performance can be secured while suppressing costs. it can.

  Although the present invention has been described with respect to a form in which the present invention is applied particularly to the combustion type nailing machine, the present invention is not limited to any other combustion type driving machine for driving other fasteners such as pins and staples. Of course, the same applies to the above.

  In the above embodiment, the deformation suppressing means is made of steel. However, any other means can be used as long as it can suppress deformation of the dustproof cover due to heat. You may make it suppress a prefectural police by providing a convex part in the part which carries out a heat deformation, for example, a cover part, and raising intensity | strength.

  Furthermore, the dust cover may be configured as a separate member from the housing, and the dust cover may be formed of an elastic material so that the impact is absorbed when an external impact is applied to the main body. Also, if an opening is provided on the side of the outer periphery of the dust cover, the exhaust gas will not directly hit the bottom of the nose, that is, when the combustion gas is exhausted from the opening. Can be prevented.

It is a side view of the combustion type nailer which concerns on Embodiment 1 of this invention. It is the sectional view on the AA line of FIG. It is a side view of the combustion type nailing machine which concerns on Embodiment 2 of this invention. It is a fracture side view of the conventional combustion type nailing machine. It is a side view of the conventional combustion type nailer. It is a perspective view of the dustproof cover single-piece | unit of the conventional combustion type nailer. It is a front view (figure of the arrow B direction of FIG. 5) of the conventional combustion type nailer. It is a top view of the conventional combustion type nailer. It is a top view of the state which removed the head cover and head protector of the conventional combustion type nailing machine. It is a perspective view which shows the state before the protection cover deformation | transformation of the conventional combustion type nailer. It is a perspective view which shows the state after the protection cover deformation | transformation of the conventional combustion type nailer.

Explanation of symbols

1,1 'combustion type nailing machine (combustion type driving machine)
DESCRIPTION OF SYMBOLS 2 Housing 2a Flange part of a housing 3 Head cover 3a Inlet of a head cover 4 Handle 4a Battery 5 Trigger switch 6 Magazine 7 Nose 7a Lower end of nose 8 Arm part 9 Push lever 10 Combustion chamber frame 10a Chamber 10b of combustion chamber frame Chamber head 11 Cylinder head 12 Spark plug 13 Motor holding cylinder 16 Filter 17 Cylinder chamber 18 Motor 19 Fan 20 Cylinder 21 Exhaust hole 22 Spring 23 Piston 23a Driver blade 24 Bumper 25 Fuel passage 25a Gas cylinder connecting portion 26 Combustion chamber 28 Covered Driving material 30 Gas cylinder 33 Switch 54 Dust-proof cover opening 55 Dust-proof cover 56 Linear steel material 57 Dust-proof cover groove 58 Screw

Claims (8)

A housing;
A cylinder head provided at one end of the housing;
A combustion chamber frame that forms a combustion chamber with the cylinder head;
A motor supported by the cylinder head;
A fan that stirs the combustion gas and air in the combustion chamber in the combustion chamber by the motor;
In the combustion type driving machine provided with a dustproof cover provided at the other end of the housing and having an opening serving as an exhaust port for the mixed gas of the combustion gas and air,
Combustion characterized in that at least a part of the dustproof cover covers the outer periphery of the housing, and a deformation suppressing means is provided for suppressing deformation of the cover part of the dustproof cover so as to be separated from the housing. Type driving machine.   The combustion type driving machine according to claim 1, wherein the deformation suppressing means is provided on an outer periphery of the covering portion.   The combustion type driving machine according to claim 1 or 2, wherein the deformation suppressing means is a linear steel material.   The combustion type driving machine according to claim 3, wherein the steel material is formed integrally with the dust cover.   The combustion type driving machine according to claim 3, wherein a groove is provided on an outer peripheral side of the dustproof cover, and the steel material is fitted in the groove.   The combustion type driving machine according to any one of claims 1 to 5, wherein the dust-proof cover has a curved shape such that a lower end side thereof is tapered with respect to the covering portion.   The combustion type driving machine according to any one of claims 1 to 6, wherein the dust cover has a lower end portion that is smaller in diameter than the inner diameter of the other end of the housing.   The dustproof cover has an outer wall portion and a tip portion extending from the outer wall portion, and the tip portion extends in a direction substantially orthogonal to the longitudinal direction of the housing. The combustion type driving machine described in 1.

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