JP2003291074A - Impact tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor-driven impact tool capable of cooling an oil pulse generating mechanism sufficiently. <P>SOLUTION: Inside the outer frame 10 of this impact tool 1, an electric motor 20 having a fan 23 on its output shaft 21, a speed reducing mechanism part 30, and the oil pulse generating mechanism 40 are installed in such a way as facing ahead of the outer frame 10 in the sequence as named. The rotation of the motor 20 is transmitted to the oil pulse generating mechanism 40 through the speed reducing mechanism part 30 and converted into a rotational pulse torque by the oil pulse generating mechanism 40. The outer frame 10 is equipped with a first exhaust hole 11A to exhaust the air from the fan 23 to ahead outward and with fin-shaped projections 10A in a position downstream of the first exhaust hole confronting the oil pulse generating mechanism 40. The air from the fan 23 flows also to the periphery of the oil pulse generating mechanism 40 within the outer frame 10. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an impact tool, and more particularly to an electric impact tool having an oil pulse generating mechanism.

[0002]

2. Description of the Related Art As a so-called impact tool used for tightening screws and the like, a type having an oil pulse generating mechanism has been conventionally known. This type of impact tool includes an outer frame, and an air motor or an electric motor that rotates at a substantially constant speed inside the outer frame. In the case of the air drive type, an air supply mechanism that supplies compressed air for rotating the air motor is provided and connected separately from the impact tool. In the case of the electric type, a power source for supplying electric power for driving the electric motor is provided inside or outside the outer frame. Further, inside the outer frame, a speed reduction mechanism section and an oil pulse generation mechanism are provided.

The oil pulse generating mechanism has an anvil that is substantially rod-shaped and points toward the front of the outer frame, a tubular body that is provided substantially coaxially with the anvil radially outward of the anvil, and a space inside the tubular body. And a blade for partitioning. The space defined by the anvil and the tubular body is filled with oil, and the blades define a plurality of oil chambers.
The tubular body is drivingly connected to the output shaft of the motor through the reduction gear mechanism, and as the motor rotates at a substantially constant speed,
The tubular body rotates at a substantially constant speed that is reduced from the output shaft of the motor. When the tubular body is rotating, the oil in the predetermined oil chamber is compressed, and a pressure difference occurs between the oil chambers. Rotation pulse torque is generated in the anvil as the anvil rotates in an attempt to eliminate this pressure difference.

When the rotating pulse torque is generated in the anvil, heat is generated by sliding a part of the anvil and a part of the cylindrical body which are in contact with each other. Further, as the oil moves from the high pressure oil chamber to the low pressure oil chamber, frictional resistance is generated and heat is generated. If this heat generation is left unattended, the temperature of the oil rises and the viscosity of the oil changes, causing output fluctuations. Further, the oil leaks from the oil pulse generating mechanism due to the thermal expansion of the oil.

In an air type impact tool, compressed air for rotating a motor is used for cooling an oil pulse generating mechanism. The compressed air used to rotate the air motor is adiabatically expanded and cooled. The cold air can be forcedly cooled by flowing it to the outer circumference of the oil pulse generating mechanism after being used for rotation of the air motor.

[0006]

However, the air type impact tool has a drawback that it is inconvenient to handle because it is necessary to provide an air supply mechanism including a compressor, an air hose and the like. On the other hand, an electric impact tool in which a motor is operated by a power source without requiring an air supply mechanism is easy to handle, but unlike the air impact tool, the oil pulse generating mechanism cannot be forcibly cooled by cold air. For example, it is theoretically possible to attach a fan to the output shaft of the electric motor and to cause air to flow around the outer periphery of the oil pulse generating mechanism inside the outer frame of the impact tool by the fan. But,
The air from the fan becomes warm due to the heat generated by the electric motor, and the oil pulse generating mechanism cannot be cooled sufficiently. Therefore, the screw tightening ability is limited to prevent excessive heating, or the work is forcibly interrupted and the work amount is restricted.

Therefore, an object of the present invention is to provide an electric impact tool which can sufficiently cool the oil pulse generating mechanism.

[0008]

In order to achieve the above object, the present invention provides an outer frame, a motor provided inside the rear of the outer frame and having a rotatable output shaft, and an outer frame. Is provided in front of the output shaft, and is provided in front of the reduction mechanism unit in the outer frame and a reduction mechanism unit that is drivingly connected to the output shaft to reduce the rotation of the output shaft. In an impact tool equipped with an oil pulse generating mechanism that is drivingly connected to the speed reducing mechanism section and converts the rotation decelerated by the speed reducing mechanism section into a rotation pulse torque, the output is generated in order to generate an air flow forward. The shaft is provided with a fan, and the outer frame is provided with a first outlet opening forwardly for discharging air from the fan to the outside of the outer frame, on the downstream side of the fan and the oil. Formed at a position upstream of the pulse generation mechanism On the outer peripheral surface of the outer frame facing to the oil pulse generating mechanism, which provides an impact tool in which a plurality of fin-like projection projecting outwardly is provided.

Here, the oil pulse generating mechanism has a cylindrical body in which a compressed fluid is enclosed and which is drivingly connected to the speed reducing mechanism section and is rotatable, and a substantially coaxial arrangement with the cylindrical body and is directed forward. And an anvil that extends between the anvil and the tubular body,
A blade for partitioning the space in the tubular body and defining a plurality of pressure fluid chambers is provided, and a rotation pulse torque is generated from the anvil by a pressure difference between fluids in the plurality of pressure fluid chambers generated by rotation of the tubular body. Fins that are output and project outwardly are provided on the outer peripheral surface of the tubular body, and the tubular body is separated from the inner circumferential surface of the outer frame to thereby An air passage through which air from the fan can pass is formed between the outer frame and the air passing through the air passage at a position downstream of the cylindrical body of the outer frame. It is preferable that a second discharge port for discharging to the front of the frame is formed.

According to the present invention, an outer frame, a motor provided inside the rear of the outer frame and having a rotatable output shaft, and a motor provided in the outer frame and in front of the output shaft, A speed reduction mechanism unit that is drive-coupled to the output shaft to reduce the rotation, and a speed reduction mechanism unit that is provided in the outer frame and in front of the speed reduction mechanism unit and is drive-coupled to the speed reduction mechanism unit to reduce the rotation. In an impact tool equipped with an oil pulse generation mechanism for converting into a rotation pulse torque, a fan is provided on the output shaft to generate a forward airflow, and the oil pulse generation mechanism has a substantially rod shape. An anvil that is directed forward and a tubular body that is provided radially outward of the anvil and that is substantially coaxial with the anvil, the tubular body being drivingly connected to the reduction mechanism unit, the reduction mechanism unit. The tubular body is rotated by Rotational pulse torque is output from the anvil, and a plurality of fins protruding outward and directed in the axial direction of the tubular body are provided on the outer peripheral surface of the tubular body. An air passage through which air from the fan can pass is formed between the cylindrical body and the outer frame by being arranged apart from the inner peripheral surface of the frame, and the cylindrical body of the outer frame is formed. Provided is an impact tool in which a second discharge port for discharging the air passing through the air passage to the front side of the outer frame is formed at a position on the downstream side of the impact tool.

[0011]

DETAILED DESCRIPTION OF THE INVENTION An impact tool 1 according to an embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 1, the impact tool 1 includes a resin housing 11, an aluminum inner cover 12, and a gear cover 1.
3 and a case 14, which are connected to each other to form the outer frame 10. The housing 11 is provided at the rearmost side of the impact tool 1, and an inner cover 12, a gear cover 13, and a case 14 are provided in this order toward the front thereof. As shown in FIG. 4, inside the outer frame 10,
An electric motor 20, a speed reduction mechanism section 30 provided on the front side thereof, and an oil pulse generation mechanism 40 provided on the front side of the speed reduction mechanism section 30 are provided. Electric motor 20
Is fixed in the housing 11. Reduction mechanism unit 30
Are supported in the inner cover 12 and the gear cover 13 by bearings 15 arranged in the inner cover 12 and the gear cover 13, respectively. Oil pulse generator 40
Is located in the case 14. The oil pulse generating mechanism 40 is drivingly connected to the output shaft 21 of the electric motor 20 through the speed reducing mechanism section 30, and the rotation of the electric motor 20 is decelerated and transmitted to the oil pulse generating mechanism 40. There is.

The housing 11 is provided with a power cord 16 for supplying electric power to the electric motor 20 and a switch 17 for switching between starting and stopping the operation of the electric motor 20. Further, an air suction hole (not shown), which is a through hole, is formed at a position rearward of the position where the electric motor 20 is provided, which is a part of the housing 11, and is rotated by a fan 23 described later. Air is allowed to flow into the inside of the outer frame 10 from an air intake hole (not shown). Further, as shown in FIG. 2, a second discharge port 14a composed of two through-holes is formed in a symmetrical position at a position in front of the oil pulse generating mechanism 40 which is a part of the case 14. Therefore, the air can be discharged from the inside of the outer frame 10 via the second discharge port 14a by the rotation of the fan 23 described later. The second outlet 14a
The size is about 2 mm in height and about 10 mm in width.

The electric motor 20 can rotate at a substantially constant speed, and the rotation is output from an output shaft 21 which is provided to face the front of the electric motor 20. A substantially funnel-shaped rotor 22 is coaxially provided around the output shaft 21 in a state in which the output shaft 21 and the front portion of the electric motor 20 are annularly mounted.
The rotor 22 can rotate integrally with the output shaft 21. On the outer peripheral surface of the rotor 22, a fan 23 is provided coaxially with the rotor 22 so as to be integrally rotatable. The fan 23 rotates as the output shaft 21 rotates, and air flows in through the air suction hole (not shown) formed in the outer frame 10 to cause the electric motor 20 to rotate.
Is configured to flow substantially forward along the outer circumference of the fan, pass through the fan 23, and further flow substantially forward.
By operating the electric motor 20, the electric motor 20
However, the air flowing around the outer periphery of the electric motor 20 can effectively cool the electric motor 20.

As shown in FIG. 3, a first outlet 11A is provided at a position downstream of the fan 23 of the outer frame 10, that is, at a position in front of the fan 23. The first outlet portion 11A is provided with a pair of outer walls 11B that protrudes outward in the radial direction of the housing in the vicinity of the front end portion of the housing 11 and faces forward in the axial direction of the housing.
An opening 11a penetrating the thickness of the housing is formed in the front end portion of the housing 11 surrounded by 1B. That is, the base end 11C of the outer wall 11B surrounds a part of the opening 11a, and the other end 11D of the outer wall portion 11B extends to a position in front of the opening 11a and where the housing 11 and the inner cover 12 are connected. There is. With this configuration, the outer wall 11B causes the first outlet 11A to open forward, and the air from the fan 23 passes through the opening 11a and is redirected forward by the outer wall 11B to be discharged. , Inner cover 12, Gear cover 1
3. The case 14 is configured to flow forward along the outer peripheral surface.

A fin-shaped projection 10A is provided on the outer peripheral surface of the outer frame 10 at the opening position of the first discharge port portion 11A. As shown in FIGS. 1 and 2, the fin-shaped projections 10A are provided in a total number of 8 on each of the left and right sides of the outer frame 10, and are integrally provided with the outer frame 10 in a state of protruding outward in the radial direction. . The fin-shaped projections 10A are parallel to each other, and the longitudinal directions thereof are oriented in the front-back direction of the outer frame 10, and the inner cover 12
It is provided from the outer peripheral surface to the predetermined position on the outer peripheral surface of the case 14. As shown in FIG. 3, the fin-shaped projection 10A has a constant height in the portions located on the inner cover 12 and the gear cover 13, but the case 14
It becomes lower toward the front in the upper part and becomes 0 at the tip.

By providing the fin-shaped projections 10A, the surface areas of the inner cover 12, the gear cover 13, and the case 14 which form the outer frame 10 are increased. Therefore, the first
The air discharged from the discharge port portion 11A is configured to pass between the adjacent fin-shaped projections 10A when flowing along the outer peripheral surfaces of the inner cover 12, the gear cover 13, and the case 14 as described above. There is. The first outlet 11
Since the fin-shaped projection 10A is provided on the front side of the opening position of A, the fin-shaped projection 10A closes a part of the opening of the first outlet 11A. The substantial opening area obtained by subtracting the area closed by the fin-shaped projection 10A from the area of the opening is configured to be equal to or larger than the area of the air suction hole (not shown).

Heat is generated in the deceleration mechanism section 30 and the oil pulse generating mechanism 40 provided in the inner cover 12 and the case 14, respectively, and this heat is generated in the inner cover 12,
It is transmitted to the case 14. Fin-shaped projections 10A on the outer peripheral surface of the outer frame 10 from the inner cover 12 to the case 14
Since the surface areas of the inner cover 12, the gear cover 13, and the case 14 are increased by the provision of, the heat dissipation in this portion is facilitated. Furthermore, since the air from the fan 23 flows between the fin-shaped projections 10A, heat dissipation can be promoted in the fin-shaped projections 10A, and the temperature increase in the speed reduction mechanism section 30 and the oil pulse generation mechanism 40 can be effectively suppressed. be able to.

Further, the air from the fan 23 is supplied to the outer wall 11
The direction of the flow is changed forward by B, and at this time, air resistance is generated. If this resistance is too large, the amount of air flowing in the outer frame 10 decreases, and the electric motor 20
Cause insufficient cooling. However, since the substantial opening area obtained by subtracting the area closed by the fin-shaped projection 10A from the area of the opening is configured to be equal to or larger than the area of the air suction hole (not shown), an appropriate amount is set. The air can be flowed, the electric motor 20 can be sufficiently cooled, and the heat generated by the oil pulse generating mechanism 40 and the like and transmitted to the fin-shaped projection 10A can be sufficiently discharged.

The oil pulse generating mechanism 40 is a known mechanism provided for converting the rotation decelerated by the speed reducing mechanism section 30 into a rotating pulse torque, and as shown in FIG. 5, the liner 41 and the liner case. And a substantially rod-shaped anvil 43 for attaching a tip tool (not shown) such as a driver. Liner 4
1 and the liner case 42 both have a cylindrical shape, and the liner 4
1 is coaxially fixed to the inner peripheral surface of the liner case 42. In the oil pulse generating mechanism 40, the liner case 42 is drivingly connected to and supported by the speed reducing mechanism section 30,
Moreover, the bearing 18 arranged in the case 14 supports the anvil 43, so that the anvil 43 is rotatable with respect to the outer frame 10. Therefore, the output shaft 21 of the electric motor 20
Is rotated at a substantially constant speed, the rotation is reduced by the speed reduction mechanism unit 30.
It is decelerated by and transmitted to the liner 41, and the liner case 42 and the liner 41 are integrally rotated at a substantially constant speed.

The inner peripheral surface of the liner 41 has a substantially elliptical shape. On the inner peripheral surface of the liner 41, the major axis and minor axis corresponding positions of the ellipse,
That is, a total of four sealing surfaces 41A protruding inward in the radial direction are provided at the upper, lower, left and right positions in FIG. A substantially rod-shaped anvil 43 is provided in the liner 41 coaxially and rotatably with respect to the liner 41.
The sealed space defined between the anvil 43 and the anvil 43 is filled with oil.

In the anvil 43, a blade insertion groove 43a penetrating in the radial direction is formed over a predetermined length in the axial direction, and two blades 45 are fitted in the blade insertion groove 43a. . A compression spring 46 is provided between the two plates 45.
The two blades 45 are biased outward by the anvil 43 in the radial direction. Therefore, the two blades 45 are configured to always contact the inner peripheral surface of the liner 41. A seal surface 43A protruding outward of the anvil 43 is provided on the outer periphery of the anvil 43 and at a radial position orthogonal to the blade insertion groove 43a. The sealing surface 43A of the anvil 43 is liner 41.
It is configured so as to be capable of sliding contact with the sealing surface 41A.

After attaching an unillustrated tip tool such as a screwdriver to the anvil 43, when the liner 41 is rotated by the operation of the electric motor 20 to tighten the screw, the load of the screw tightening causes the liner 41 to rotate more than the liner 41 rotates. The rotation of the anvil 43 is slowed down, and the anvil 43 rotates relative to the liner 41. At this time, the seal surface 43A of the anvil 43 and the seal surface 41A of the liner 41 temporarily contact, and the space filled with oil is temporarily divided into four oil chambers. Then, as the anvil 43 further rotates, the oil inside the predetermined oil chamber is compressed, and a pressure difference is generated between the oils filled in the oil chambers. Anvil 43 trying to eliminate this pressure difference
The rotation pulse torque is generated in the anvil 43 by rotating in the opposite direction.

A cylinder 44 is fixedly provided to the liner case 42 on the outer periphery of the liner case 42.
A plurality of fin-shaped projections 44A, which are fins that project outward and are oriented in the axial direction of the tubular body, are provided on the outer peripheral surface of the. The fin-shaped projections 44A are arranged at equal intervals over the entire circumference of the outer circumference of the cylindrical body 44 in the circumferential direction. The height of the fin-like protrusion 44A protruding outward is determined so that the distance between the tip of the fin-like protrusion 44A and the inner peripheral surface of the case 14 is 1.5 to 2 mm. A space formed between the outer peripheral surface of the cylindrical body 44 and the case 14 forms an air passage 10a communicating with the second outlet 14a. The fin-shaped projections 4 are formed on the outer peripheral surface of the cylindrical body 44
Since 4A is provided, the oil pulse generation mechanism 40
The surface area of the outer circumference can be increased, and the heat generated by the oil pulse generation mechanism 40 can be effectively released.

As shown in FIG. 4, the outer peripheral surface of the reduction mechanism 30 and the inner cover 1 are located in the lower portion of the outer frame 10.
2, the inner peripheral surface of the gear cover 13, and the housing 1
A space, which is an air passage 10b, is defined between the inner peripheral surface of 1 and the inner peripheral surface of 1. The air passage 10b communicates with the air passage 10a. The air passage 10a communicates with the second discharge port 14a, so that the air from the fan 23 is supplied to the air passage 10a.
It is configured to flow around b and 10a, flow around the cylinder body 44 of the oil pulse generating mechanism 40, and be discharged from the second discharge port 14a (not shown). Therefore, the oil pulse generation mechanism 40 can be cooled by the air from the fan 23, and the oil pulse generation mechanism 40 can be prevented from being heated. Further, since a plurality of fin-shaped projections 44A that project outward and are oriented in the axial direction of the tubular body 44 are provided on the outer peripheral surface of the tubular body 44, it is possible for the tubular body 44 to rotate integrally with the liner 41. Accordingly, the air from the fan 23 flowing around the outer periphery of the cylindrical body 44 is agitated by the fin-shaped protrusions 44A, and the oil pulse generation mechanism 40 can be cooled more effectively. The height of the air passage 10b is 4 mm.
And the width is about 30 mm.

Further, as described above, the height of the protrusion 44A protruding outward is determined so that the distance between the tip of the protrusion 44A and the inner peripheral surface of the case 14 is 1.5 to 2 mm. The passage is relatively narrow because it is located in the area. Therefore, when the air from the fan 23 flows into the air passage 10a which is a narrow space, the flow velocity of the air can be increased. Therefore, the heat accumulated in the case 14 can be effectively discharged from the second discharge port 14a to the outside, and the heat transferred to the surface of the tubular body 44 is also discharged to the outside from the second discharge port 14a. can do.

The operation of the impact tool 1 is as follows. After the user attaches a tip tool such as a driver to the anvil 43, the switch 17 is operated to rotate the electric motor 20 at a substantially constant speed. The rotation of the electric motor 20 is decelerated by the speed reduction mechanism unit 30 and transmitted to the liner 41 of the oil pulse generation mechanism 40, and the liner 41 rotates. The load applied to the anvil 43 by tightening the screws causes the liner 4 to move.
1 rotates relative to the anvil 43. And
When the four sealing surfaces 41A of the liner 41 and the two sealing surfaces 43A and the two blades 45 formed on the outer peripheral surface of the anvil 43 come into contact with each other and slide with each other, two high pressure chambers and two Four chambers consisting of a low pressure chamber are formed. The oil is compressed in the high pressure chamber, and the pressure of the compressed oil is about to be released, so that the anvil 43 is temporarily rotated in the opposite direction to generate the rotation pulse torque. In the oil pulse generating mechanism 40, the screw is tightened by repeatedly compressing and releasing the oil and repeatedly generating the impact torque.

When the striking torque is generated, heat is generated in the oil pulse generating mechanism 40 by the friction when the oil is pushed from the high pressure chamber to the low pressure chamber and the sliding friction between the blade 45 and the liner 41. . When the temperature inside the oil pulse generating mechanism 40 becomes higher than that of the components directly or indirectly connected to the oil pulse generating mechanism 40, heat starts to move from the oil pulse generating mechanism 40 to these components. Specifically, it moves from the liner case 42 to the fin-like protrusions 44A, then from the liner case 42 to the speed reduction mechanism unit 30, and from the speed reduction mechanism unit 30 to the bearing 1.
5 to the inner cover 12, the gear cover 13,
Heat is transferred from the anvil 43 to the case 14 via the bearing 18.

By the way, as the fan 23 rotates with the rotation of the electric motor 20, two air flows are generated inside the outer frame 10. On the other hand, the air flowing from the fan 23 to the outer frame opening 11a hits the outer wall 11B and changes its direction forward, and passes between the fin-shaped projections 10A along the outer peripheral surface of the inner cover 12, the gear cover 13, and the case 14. Is. Due to this flow, heat is transferred from the oil pulse generation mechanism 40 and the temperature of the inner cover 1 is raised.
2. The gear cover 13 and the case 14 are cooled.

The other is a flow that flows along the outer peripheral surface of the oil pulse generating mechanism 40, is agitated by the fin-like projections 44A, and is discharged from the second discharge port 14a. In this flow, the air flows into the air passage 10a, which is a narrow gap, so that resistance is received between the cylindrical body 44 and the case 14. As a result, the pressure in the air passage 10a rises, and the flow velocity increases. Such fast-flowing air is case 1
4 flows one after another, and the heat trapped in the case 14 is the second
At the same time as being discharged to the outside from the discharge port 14a, the heat moving from the inside of the oil pulse generating mechanism 40 to the surface of the cylindrical body 44 is also discharged to the outside from the second discharge port 14a.

Further, these two flows are formed by the air flowing into the outer frame 10 from the air suction hole (not shown). When the inflowing air is sucked by the fan 23, the air flows around the electric motor 20 and the electric motor 20 is cooled.

The impact tool according to the present invention is not limited to the above-mentioned embodiment, and various modifications and improvements can be made within the scope of the claims. For example, in the impact tool 1 according to the present embodiment, the electric motor 20 is operated by the electric power supplied by the power cord 16. However, instead of the power cord 16, electric power is supplied from a battery, a battery, or the like. May be.

[0032]

According to the impact tool of the first aspect, the output shaft is provided with a fan, and the outer frame is provided with a first opening for opening forward and for discharging air from the fan to the outside of the outer frame. 1 fins are formed on the outer peripheral surface of the outer frame facing the oil pulse generating mechanism, and the fins protruding outward are provided on the outer frame. The transferred heat can be effectively released in the outer frame by the air from the fan, and the temperature of the oil pulse generating mechanism that generates heat can be kept within the allowable range.

According to the impact tool of claim 2,
Since the tubular body is arranged away from the outer frame, an air passage through which air from the fan can pass is formed between the tubular body and the outer frame. The outer periphery of the generation mechanism can be cooled, and the oil pulse generation mechanism can be prevented from overheating. Therefore, by the air from the fan,
The outer frame and the outer peripheral surface of the oil pulse generating mechanism can be cooled at the same time. Further, since the plurality of fins are provided on the outer peripheral surface of the tubular body, the heat radiation effect of the tubular body can be enhanced, and in addition to the cooling from the outer surface of the outer frame according to claim 1, a further effect can be obtained. The outer circumference of the oil pulse generating mechanism can be cooled effectively.

According to the impact tool of claim 3,
Since the tubular body is arranged away from the outer frame, an air passage through which air from the fan can pass is formed between the tubular body and the outer frame. The outer circumference of the generating mechanism is directly cooled. Here, since a plurality of fins protruding outward and directed in the axial direction of the tubular body are provided on the outer peripheral surface of the tubular body, a fan that flows around the outer periphery of the tubular body as the tubular body rotates The air from is agitated by the fins, the outer circumference of the oil pulse generating mechanism can be cooled more effectively, and excessive heating of the oil pulse generating mechanism can be prevented.

[Brief description of drawings]

FIG. 1 is a side view showing an impact tool according to an embodiment of the present invention.

FIG. 2 is a front view of the impact tool according to the embodiment of the present invention.

FIG. 3 is a cross-sectional view of main parts taken along the line III-III of FIG.

FIG. 4 is a sectional view of a main part taken along the line IV-IV of FIG.

5 is a cross-sectional view of the oil pulse generation mechanism taken along the line VV of FIG.

[Explanation of symbols]

1 impact tool 10 outer frame 10A Fin-shaped protrusion 10a, 10b Air passage 11 housing 11A First discharge port 11B outer wall 11a opening 12 Innaba 13 gear cover 14 cases 14a Second outlet 20 electric motor 21 Output shaft 23 fans 30 Reduction mechanism 40 Oil pulse generation mechanism 43 Anvil 44 cylinder 44A Fins

Claims (3)

[Claims] 1. An outer frame, a motor provided inside the rear of the outer frame and having a rotatable output shaft, a motor provided in the outer frame and in front of the output shaft, A speed reduction mechanism section that is drivingly connected to reduce the rotation of the output shaft; and a speed reduction mechanism section that is provided in the outer frame and in front of the speed reduction mechanism section.
In an impact tool equipped with an oil pulse generating mechanism that is drivingly connected to the speed reducing mechanism section and converts the rotation decelerated by the speed reducing mechanism section into a rotation pulse torque, the output is generated in order to generate an air flow forward. The shaft is provided with a fan, and the outer frame has a first outlet opening toward the front for discharging air from the fan to the outside of the outer frame, the first outlet being downstream of the fan and the oil. A plurality of fin-shaped projections protruding outward are provided on the outer peripheral surface of the outer frame which is formed at a position upstream of the pulse generation mechanism and faces the oil pulse generation mechanism. Impact tool to do. 2. The oil pulse generating mechanism, wherein a compressed fluid is enclosed inside and is rotatably driven by the speed reduction mechanism portion to be rotatable, and the oil pulse generating mechanism is disposed substantially coaxially with the tubular body and is directed forward. An anvil; and a blade extending between the anvil and the tubular body, partitioning a space inside the tubular body, and defining a plurality of pressure fluid chambers,
Rotational pulse torque is output from the anvil due to the pressure difference between the fluids in the plurality of pressure fluid chambers generated by the rotation of the tubular body, and fins projecting outward are provided on the outer peripheral surface of the tubular body. By arranging the tubular body away from the inner peripheral surface of the outer frame, an air passage through which air from the fan can pass is formed between the tubular body and the outer frame, A second portion for discharging the air passing through the air passage to the front side of the outer frame at a position on the downstream side of the cylindrical body of the outer frame.
The impact tool according to claim 1, wherein a discharge port is formed. 3. An outer frame, a motor provided inside the rear of the outer frame and having a rotatable output shaft, and a motor provided in the outer frame and in front of the output shaft, A reduction mechanism portion that is drive-coupled to reduce the rotation, and is provided in the outer frame and in front of the reduction mechanism portion,
In an impact tool equipped with an oil pulse generating mechanism that is drivingly connected to the reduction mechanism and converts the reduced rotation into rotation pulse torque, a fan is attached to the output shaft to generate a forward airflow. The oil pulse generating mechanism includes an anvil that is substantially rod-shaped and points forward, and a cylindrical body that is provided substantially coaxially with the anvil radially outward of the anvil. A body is drivingly connected to the reduction mechanism, and the reduction mechanism rotates the cylindrical body to output a rotation pulse torque from the anvil. The rotation pulse torque is output outward on the outer peripheral surface of the cylindrical body. A plurality of fins that project and are directed in the axial direction of the tubular body are provided, and the tubular body is arranged away from the inner peripheral surface of the outer frame, so that the tubular body and the outer frame are separated from each other. The air from the fan A passable air passage is formed, and a second portion for discharging the air passing through the air passage to the front of the outer frame is provided at a position on the downstream side of the cylindrical body of the outer frame.
An impact tool that has a discharge port.