JP4470696B2 - Electric tool - Google Patents

Description

  The present invention relates to an electric tool, and more particularly to an electric tool provided with a mechanism for transmitting rotation of an electric motor.

  An electric motor is provided in a housing of an electric tool such as a hammer drill, and a cylinder driven by the electric motor is rotatably supported at a tip position of the housing, and a tip tool is attached to the tip of the cylinder. In addition, a speed reduction mechanism portion is provided in the housing, and the rotation of the electric motor is transmitted to the tip tool via the speed reduction mechanism portion.

  The speed reduction mechanism is housed in a mechanism chamber defined by a housing, and includes a rotation transmission mechanism such as a gear or an intermediate shaft. The rotation of the electric motor is transmitted to the intermediate shaft by a gear and is transmitted to the tip tool through the intermediate shaft. Bearings are provided at positions on both ends of the intermediate shaft in the mechanism chamber. The bearing supports the intermediate shaft rotatably.

Lubricants for improving durability and reducing friction loss are applied to the gears and intermediate shafts of the speed reduction mechanism. As the lubricant, for example, grease containing a metal soap base such as Ca and Li and an oil component such as silicone oil is used. This grease has good fluidity and softness so as not to impair lubricity even at low temperatures. This soft grease has a lot of oil components, and has a tendency to increase the fluidity and become separated from the soap base and the oil components at a high temperature. Therefore, a high sealing performance is required for the mechanism chamber so that grease does not flow out of the mechanism chamber. Therefore, the mechanism chamber has a sealed structure using a plurality of types of seal members such as an O-ring, an oil seal, and a sealed (contact type) ball bearing. An electric power tool having such a configuration is described in Patent Document 1, for example.
JP-A-1-316178 (2 pages, FIG. 1 and FIG. 2)

  In the conventional electric power tool, according to the part to be sealed, different types of seal members are used as described above, the mechanism chamber has a sealed structure, and the sealing performance is also different. When the speed reduction mechanism generates heat during use of such a power tool, the temperature in the sealed mechanism chamber rises and the air inside expands. In this case, if the sealing performance is lowered at any one of the different types of sealing members described above, the expanded air flows out of the mechanism chamber together with grease from the position of the sealing member. When such leakage of grease occurs, not only the quality and durability of the product are deteriorated, but also the problem is that the place where the work is performed is soiled.

  In particular, there is a power tool that has a conversion mechanism that converts a rotary motion into a reciprocating motion, and that reciprocates a cylindrical piston provided in a housing by the conversion mechanism. This electric tool is equipped with an impact transmission mechanism in the housing that follows the reciprocating motion of the cylindrical piston to reciprocate the impactor and intermediate, and transmit the impact force to the tip tool. Move back and forth. For this reason, it is necessary to load a relatively large amount of grease with good fluidity in the mechanism chamber. In addition, the pressure in the mechanism chamber is significantly increased due to heat generated by the high-speed reciprocating motion. Therefore, the grease heated by heat generation and having improved fluidity is more likely to flow out from the seal position.

  Therefore, the present invention provides an electric tool that suppresses the expansion of air in the mechanism chamber and prevents the lubricant enclosed in the mechanism chamber from leaking outside the mechanism chamber, thereby improving quality and durability. For the purpose.

In order to achieve the above object, the present invention includes a housing that partially defines a mechanism chamber , and a lubricant sealed inside the mechanism chamber , an electric motor accommodated in the housing, An electric tool provided with a transmission mechanism provided in a mechanism chamber for shifting the rotation of the electric motor, and provided with an inlet provided in the housing and opening to the mechanism chamber and an outlet communicating with the inlet. A communication portion forming portion that forms the communication portion, and a first filter and a second filter that block an entrance / exit direction of the communication portion, and the second filter is provided on the outlet side from the first filter. Provide power tools.

  The electric tool includes a cylinder that is rotatably supported in the housing and can hold a tip tool, a rotation transmission mechanism that transmits the rotation of the electric motor to the cylinder and rotates the cylinder about its axis. May be further provided. This makes it possible to apply not only to a power tool that uses only a rotary motion such as a drill, but also to a power tool that uses a reciprocating motion such as a hammer drill.

  Further, it is desirable that the second filter has a higher filtering performance than the first filter. As a result, it is possible to filter the lubricants in different states such as particle size and viscosity with filters suitable for filtering the lubricants.

  In addition, the first filter and the second filter are preferably made of a felt base material, and a first filter position for fixing a position of the first filter and the second filter to the communication portion. It is desirable that a fixing part and a second filter position fixing part are provided.

  In addition, a communication path forming component that is inserted in the communication portion between the first filter and the second filter and forms a communication path that communicates with the communication portion between the inside and outside of the mechanism chamber is further provided. At least one of the passage forming component and the communication portion forming portion is provided with a collision portion that defines a part of the communication passage, and the air that has flowed into the communication passage from the inlet portion via the first filter. Alternatively, the lubricant may be discharged to the outside of the outlet through the second filter after colliding with the collision portion.

  Further, in the direction from the inlet to the outlet, the inner wall surface of the communicating part may be formed in an uneven shape alternately.

  According to the electric tool of the first aspect of the present invention, the air in the mechanism chamber is discharged outside after passing through the first filter and the second filter. At this time, the spray-like or droplet-like lubricant contained in the air is scraped off by the first filter and the second filter. Accordingly, the lubricant contained in the air discharged from the mechanism chamber to the outside air is removed before passing through the second filter, and is prevented from being discharged to the outside.

  According to the electric tool of the second aspect, the effect according to the first aspect can be obtained not only in the rotational movement but also in the electric tool that performs a reciprocating movement. Therefore, even if it is a hammer drill etc., it will be suppressed that the grease etc. which were enclosed are discharged | emitted outside.

  According to the third aspect of the present invention, only the lubricant having a solid shape, such as a solid lubricant or a droplet lubricant, is scraped off by the first filter. Then, the sprayed or liquid lubricant is scrubbed with the second filter. Thereby, it becomes possible to prevent clogging of the first filter and the second filter and to suitably discharge the air from the communication portion and to suppress the lubricant from being discharged from the communication portion.

  According to the electric tool of the fourth aspect, the thickness of the felt can be easily set, and the filtration performance can be easily changed by changing the thickness, the packing density, and the like. In addition, since the felt can be easily processed such as cutting, workability during manufacturing can be improved.

  According to the electric tool of the fifth aspect, the position of the first filter and the second filter can be easily fixed, and can be fixed at an accurate position.

  According to the sixth aspect of the present invention, the air that has passed through the first filter collides with the collision portion. At this time, the lubricant that has not been removed by the first filter adheres to the collision portion. When the lubricant adheres to the collision portion, the lubricant contained in the air between the first filter and the second filter is removed in the communication path, and the lubricant reaching the second filter can be reduced. It becomes possible. Therefore, it becomes possible to suppress that the filtration performance in a 2nd filter reduces. Moreover, by providing the collision part, the communication path becomes a complicated path such as a bent part in the middle of the path. Therefore, the liquid lubricant can be prevented from propagating through the inner wall of the communication path due to surface tension or the like and leaking outside.

  According to the seventh aspect of the present invention, the unevenness is provided on the inner surface of the communication portion, thereby hindering the lubricant from propagating on the inner surface of the communication portion. Therefore, it is possible to suppress the liquid lubricant from reaching the second filter and further suppress the lubricant from being discharged to the outside.

  A power tool according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 3. As shown in FIG. 1, the electric tool is specifically a hammer drill 1, and a casing is constituted by the handle portion 10, the motor housing 20, and the gear housing 30.

  A power cable 11 is attached to the handle portion 10 and a switch mechanism (not shown) is built therein. A trigger 12 that can be operated by a user is mechanically connected to a switch mechanism (not shown). The power cable 11 connects the switch mechanism to an external power source (not shown) and operates the trigger 12 to switch between connection and disconnection between the switch mechanism and the power source.

  The motor housing 20 is provided on the upper portion of the handle portion 10. The handle portion 10 and the motor housing 20 are integrally formed of plastic. An electric motor (not shown) is accommodated in the motor housing 20. The electric motor includes an output shaft 21 and outputs a rotational driving force.

  The gear housing 30 is a resin molded product provided in front of the motor housing 20. Inside the gear housing 30, a metal support member 30 </ b> A that partitions the gear housing 30 and the motor housing 20 is provided. The gear housing 30 and the support member 30A define a deceleration chamber 30a that is a mechanism chamber that houses a rotation transmission mechanism described later. The gear housing 30 including the speed reduction chamber 30a contains grease, which is a lubricant for reducing friction of gears and the like described later, and is supplied to each sliding portion. This grease has a soap base and an oil component such as silicone oil as main components.

  In the gear housing 30, an intermediate shaft 32 is supported in parallel with the output shaft 21 on the gear housing 30 and the support member 30 </ b> A via bearings 32 </ b> B and 32 </ b> C so as to be rotatable about its axis. Bearings 32B and 32C for supporting the intermediate shaft 32 are made of sealed (non-contact type) ball bearings, are provided at both ends of the intermediate shaft 32, and are supported by a part of the gear housing 30 and the support member 30A. Yes. Further, a side handle 13 is provided in the vicinity of the tool holding portion 35 described later of the gear housing 30.

  A motor pinion gear 22 is provided at the tip of the output shaft 21. A first gear 31 that meshes with the motor pinion gear 22 is coaxially fixed to the end of the intermediate shaft 32 on the electric motor side. A gear portion 32A is formed on the distal end side of the intermediate shaft 32 and meshes with a second gear 33 described later. A casing constituted by the handle portion 10, the motor housing 20, and the gear housing 30 and the support member 30A correspond to the housing.

  A cylinder 34 is provided in the gear housing 30 at a position above the intermediate shaft 32. The cylinder 34 extends parallel to the intermediate shaft 32 and is rotatably supported by the support member 30A. The second gear 33 is fixed to the outer periphery of the cylinder 34, and the cylinder 34 can rotate around its axis by meshing with the gear portion 32A described above.

  The tool holding portion 35 described above is provided on the tip side of the cylinder 34, and the tip tool 60 is detachably attached. The support member 30A is made of metal because it supports the motor pinion gear 22, the intermediate shaft 32, and the cylinder 34, and therefore requires higher mechanical strength than the gear housing 30 and the motor housing 20.

  The intermediate shaft 32 is spline-engaged with a clutch 36 that is biased in the direction of the electric motor by a spring at the intermediate portion. ) And drill mode (position where the clutch 36 has moved in the distal direction). On the side of the electric motor of the clutch 36, a motion conversion unit 40 that converts rotational motion into reciprocating motion is externally mounted on the intermediate shaft 32. The arm 40 </ b> A of the motion converter 40 is provided so as to be able to reciprocate in the front-rear direction of the hammer drill 1 by the rotation of the intermediate shaft 32.

  When the clutch 36 is switched to the hammer drill mode by the change lever 37, the intermediate shaft 32 and the motion conversion unit 40 are coupled by the clutch 36, and the motion conversion unit 40 is connected via the piston pin 41. Thus, it is connected so as to be interlocked with a piston 42 provided in the cylinder 34. The piston 42 is mounted so as to be able to reciprocate in a direction parallel to the intermediate shaft 32 and to be slidable in the cylinder 34. A striking element 43 is housed inside the piston 42, and an air chamber 44 is defined in the cylinder 34 between the piston 42 and the striking element 43. At a position opposite to the air chamber side of the striker 43, an intermediate element 45 is supported in the cylinder 34 so as to be slidable in the direction of movement of the piston 42. A tip tool 60 is located at a position opposite to the striker side of the intermediate element 45. Therefore, the striker 43 strikes the tip tool 60 via the intermediate element 45.

  A rotation output of a motor (not shown) is transmitted from the motor pinion gear 22 to the intermediate shaft 32 via the first gear 31. The rotation of the intermediate shaft 32 is transmitted to the cylinder 34 by the engagement of the gear portion 32 </ b> A and the second gear 33 provided on the cylinder 34, and the rotational force is transmitted to the tip tool 60. When the clutch 36 is moved to the hammer drill mode by operating the change lever 37, the clutch 36 is coupled to the motion conversion unit 40, and the rotational driving force of the intermediate shaft 32 is transmitted to the motion conversion unit 40. In the motion converter 40, the rotational driving force is converted into the reciprocating motion of the piston 42 via the piston pin 41. The air chamber 44 defined between the striking element 43 and the piston 42 by the reciprocating motion of the piston 42 also repeats compression and expansion, and imparts striking force to the striking element 43. The striker 43 moves forward and collides with the rear end surface of the intermediate element 45, and the impact force is transmitted to the tip tool 60 via the intermediate element 45. In this manner, in the hammer drill mode, the turning force and the striking force are simultaneously applied to the tip tool 60.

  When the clutch 36 is in the drill mode, the clutch 36 disconnects the intermediate shaft 32 and the motion converting portion 40, and only the rotational driving force of the intermediate shaft 32 is applied to the cylinder 34 via the gear portion 32 </ b> A and the second gear 33. Communicated. Therefore, only the rotational force is applied to the tip tool 60.

  The speed reduction chamber 30a defined by the gear housing 30 and accommodating the rotation transmission mechanism is sealed with a plurality of types of seal members. These seal members prevent the grease in the gear housing 30 from leaking outside.

  Specifically, an oil seal 71 is provided between the peripheral surface of the cylinder 34 and the gear housing 30, and an O-ring 72 is mounted on the inner surface of the cylinder 34 that supports the intermediate element 45, and the change lever 37 and the gear housing 30. An O-ring 73 is provided at the connection position. Further, an O-ring 74 is provided at a connection position between the support member 30A and the gear housing 30, and a bearing (not shown) for supporting the motor pinion gear 22 is constituted by a sealed (contact type) ball bearing, and a reduction chamber Contributes to the 30a seal.

  As shown in FIGS. 1 and 2, it is a substantially intermediate position between the intermediate shaft 32 of the support member 30A and the cylinder 34. As shown in FIG. 2, the support member 30A is viewed from the tip tool 60 side on the right side. The communication part forming part 30B is provided. As shown in FIG. 3, the communication portion forming portion 30B includes an inlet 30c that is an opening that opens to the deceleration chamber 30a and an outlet 30d that opens into the motor housing 20 that communicates with the outside air. The communication part 30b which connects this entrance 30c and the exit 30d is formed. The inner diameter of the communication portion 30b is slightly larger than the opening diameter of the inlet 30c, and a groove portion 30e is formed in the inner periphery in the vicinity of the outlet 30d.

  A first felt filter 52A having a coarse mesh is inserted on the most entrance side in the communication portion 30b to block the direction of the entrance / exit of the communication portion 30b. The diameter of the first filter 52A is substantially the same as or slightly larger than the inner diameter of the communication portion 30b. Further, the first filter 52A is made thinner than a second filter 52B described later in order to prevent clogging.

  By using felt for the first filter 52A and the second filter 52B described later, the thickness, packing density, and the like can be easily changed. The filtration performance of the filter can be easily changed by changing the thickness, packing density, and the like. In addition, since the felt can be easily processed such as cutting, workability during manufacturing can be improved.

  A communication path forming component 51 is inserted in the communication portion 30b and on the outlet 30d side of the first filter 52A. The communication path forming component 51 communicates in a state where one end abuts the first filter 52A and is smaller than the inner diameter of the communication portion 30b and the other end of the head 51A and is not attached to the communication portion 30b. A body 51D having a diameter larger than the inner diameter of the part 30b, and a flange 51E provided at the other end side position of the body 51D and fitted into the groove 30e, are made of an oil-resistant rubber material.

  Since the communication path forming component 51 is made of a rubber material, the communication path forming component 51 can be deformed and easily press-fitted into the communication portion 30b, and the flange portion 51E can be easily fitted into the groove portion 30e. . Further, even after the communication path forming component 51 is fitted into the communication portion 30b, the trunk portion 51D is in close contact with the inner surface of the communication portion 30b due to the elastic force of the rubber material. Therefore, it is difficult for a gap to be formed between the trunk portion 51D and the communication portion 30b, and it is possible to prevent grease from leaking from the gap, and it is difficult for deviation to occur.

  Further, by inserting the flange 51E into the groove 30e, the communication path forming component 51 can be positioned in the communication portion 30b. As a result, it is possible to make a communication path 53, which will be described later, constituted by the communication path forming component 51 and the inner surface of the communication portion 30b suitable and uniform in size.

  A perforation 51c is provided in the communication path forming component 51 and has an opening on the other end side of the body portion 51D, and is drilled toward the head 51A side to a substantially central portion of the head 51A. In the head portion 51A, a side hole 51b that penetrates the head portion 51A is formed substantially perpendicularly to the perforation 51c from the inside of the perforation 51c toward the inner surface of the communication portion 30b. Therefore, there is a bent portion where the side holes 51b and the perforations 51c are continuous. Since the outer diameter of the head portion 51A is formed smaller than the inner diameter of the communication portion 30b, an annular shape is formed between the inner surface of the communication portion 30b and the head portion 51A from the portion of the head 51A in contact with the first filter 52A. A gap 51a is formed. Since the side hole 51b is opened on the surface facing the inner surface of the communication portion 30b of the head 51A, it communicates with the gap 51a. At this time, since the side hole 51b is opened on the inner surface that defines the gap 51a, there is a bent portion where the gap 51a and the side hole 51b are continuous. A communication path 53 is formed on the downstream side in the order of the side hole 51b and the perforation 51c. Since the communication path forming component 51 is made of rubber as described above, the complicated paths of these communication paths 53 are easily formed.

  Since the trunk portion 51D has a larger diameter than the head portion 51A, there is a step at the boundary between the head portion 51A and the trunk portion 51D. Moreover, since the trunk | drum 51D is contact | abutting with the communication part 30b inner surface, it becomes a bag small path-like body in the level | step-difference part of the boundary of the head 51A and trunk | drum 51D, and this level | step-difference part is prescribed | regulated as the 1st collision part 51B. The fluid flowing in the gap 51a once collides with the vicinity of the first collision portion 51B and then flows into the side hole 51b orthogonal to the flow direction in the gap 51a. A surface of the inner surface of the perforated 51c that faces the opening of the side hole 51b is defined as a second collision portion 51C. The fluid that flows in the side hole 51b collides with the second collision portion 51C, and then the fluid flows in the perforation 51c.

  A second filter 52B is provided in the communication portion 30b and on the outlet 30d side of the communication passage forming component 51 so as to be fitted into the groove portion 30e so as to block the entrance / exit direction of the communication portion 30b. The second filter 52B is made of felt that is thicker and finer than the first filter 52A, and its filtration performance is higher than that of the first filter. Further, since the second filter 52B is fitted in the groove 30e, the communication path forming component 51 is urged and held toward the inlet 30c. Since the head 51A is in contact with the first filter 52A, the first filter 52A is urged and held by the communication portion forming portion 30B around the opening of the inlet 30c.

  Hereinafter, the case where it drills using the hammer drill 1 of the said structure is demonstrated. When drilling with the hammer drill 1, the trigger 12 is pulled while the side handle 13 and the handle portion 10 are held with both hands, and a motor (not shown) is supplied with electric power to be driven to rotate. The power of this motor is transmitted as rotational force to the tip tool 60 by a rotation transmission mechanism such as the motor pinion gear 2, the first gear 31, the intermediate shaft 32, the gear portion 32A, the second gear 33, and the like. At this time, since grease is supplied to each gear and the like, the friction loss of the driving force is reduced, but some friction is generated, which is converted into heat energy to generate heat. Further, the rotational driving force is converted into the reciprocating motion force via the motion conversion unit 40, and the striking force is generated by the piston 42 and the intermediate element 45. In this case, compression heat is generated by the air being compressed in the air chamber 44 in the piston 42, and a part of the kinetic energy at which the striker 43 collides with the intermediate element 45 is converted into heat energy to generate heat.

  Due to these heat generation factors, the inside of the gear housing 30 is heated, and the grease contained therein is also heated. When heated, the grease tends to increase fluidity and easily separate into soap base and oil. Further, since air exists in the gear housing 30, the volume of the air expands when the gear housing 30 is heated. Since each seal portion has airtightness, the heated and expanded air is discharged into the atmosphere through a communication portion 30b having openings in and out of the speed reduction chamber 30a in the gear housing 30.

  The heated air in the gear housing 30 contains a grease component. By passing this air through the first filter 52A, a soap base having a relatively high viscosity and large particles in the form of solid or droplets in the grease is scavenged. Therefore, the oil and air in the grease pass through the first filter 52A.

  The air or the like that has passed through the first filter 52A passes through the communication path 53 and further reaches the second filter 52B. In the communication passage 53, a plurality of bent portions are formed in the middle of the passage structure, and a first collision portion 51B and a second collision portion 51C, which are collision portions, are defined here. Therefore, the air that still contains the grease component that has passed through the first filter 52A collides with the first collision part 51B and the second collision part 51C and the flow is disturbed, and the grease component contained in the air is It adheres to 51B and the 2nd collision part 51C.

  After passing through the communication path 53, air or the like flows into the second filter 52B. Since the second filter 52B uses a felt having higher filtration performance than the first filter 252A, it is also possible to filter oil contained in the air, and the oil that has passed through the communication path 53. Is suppressed and discharged from the second filter 252B to the outside. Therefore, the grease contained in the air discharged from the inside of the deceleration chamber 30a to the outside air is removed before passing through the second filter 52B, and is prevented from being discharged to the outside from the communication portion 30b. In addition, the communication passage 53 suppresses leakage of liquid grease through the inner wall surface of the communication passage 53 due to its fluidity, surface tension, and the like due to a complicated path having bent portions and the like.

  After the use of the hammer drill 1 is stopped, the internal air is also cooled by naturally cooling the deceleration chamber 30a and the like, and the volume thereof is reduced. Thereby, since the inside of the deceleration chamber 30a becomes a negative pressure, the outside air flows from the second filter 52B through the communication path 53 to the deceleration chamber 30a via the first filter 52A. At this time, the grease component adhering to the first filter 52A and the second filter 52B can be reduced into the deceleration chamber 30a together with the inflowing air. Therefore, the first filter 52A and the second filter 52B are less likely to be clogged, and can maintain the filtration performance for a long time.

  Further, the hammer drill 1 is displayed with a mark such as a product name or a trademark on the right side when the support member 30A is viewed from the tip tool 60 side, and the hammer drill 1 is packed with the right side as an upper surface at the time of shipment or the like. It is. Therefore, when the support member 30A is viewed from the end tool 60 side, the communication portion forming portion 30B is provided on the right side to form the inlet 30c, so that the grease contained in the deceleration chamber 30a at the time of shipment passes through the communication passage 53. It is suppressed from being discharged to the outside. Even when the hammer drill 1 is owned by the user, for example, if the hammer drill 1 is not in use, it can be displayed by displaying, for example, “When the hammer drill 1 is not in use, keep the right side up.” It is possible to prevent the grease from being discharged to the outside by invoking a storage method.

  Next, a second embodiment will be described with reference to FIG. Since the hammer drill according to the present embodiment is the same as the first embodiment except for the configuration related to the communication portion forming portion 230B, the description thereof is omitted.

  As shown in FIG. 4, the communication portion forming portion 230B provided on the support member 30A in the gear housing 30 has an inlet 230c that is an opening opening to the deceleration chamber 30a and the motor housing 20 that is in communication with the outside air. An outlet 230d that opens inside is defined, and a communication portion 230b that connects the inlet 230c and the outlet 230d is formed. A groove 230f is formed in the vicinity of the inlet 230c in the communication portion 230b over the inner periphery of the communication portion 230b, and a groove 230e is also formed in the vicinity of the outlet 230d. Between this groove part 230f and the groove part 230e, the uneven | corrugated | grooved part 230g with which the unevenness | corrugation was carved in the circumferential direction of the communicating part 230b was formed.

  A first filter 252A made of felt with a coarse mesh is fitted into the groove 230f, and a second filter 252B is fitted into the groove 230e to block the communication part 230b. The first filter 252A is made thinner than the second filter 252B to prevent clogging. The second filter 252B is made of felt that is thicker and finer than the first filter 252A, and its filtration performance is higher than that of the first filter 252A. The groove 230e and the groove 230f make it easy to fix the positions of the first filter 252A and the second filter 252B and fix them at an accurate position.

  When the air in the deceleration chamber 30a is discharged into the atmosphere through the communication portion 230b due to the pressure increase in the deceleration chamber 30a as described above, first, the air flows into the communication portion 230b from the inlet 230c. Pass 252A. At this time, a soap base having a relatively high viscosity and large particles in the form of solid or droplets in the grease is scraped off. Therefore, the oil and air in the grease pass through the first filter 252A and then flow into the second filter 252B. Since the second filter 252B uses a felt having higher filtering performance than the first filter 252A, it is possible to filter oil contained in the air, and the oil that has passed through the communication portion 230b. Is suppressed and discharged from the second filter 252B. Therefore, the grease component contained in the air discharged from the deceleration chamber 30a to the outside air is removed before passing through the second filter 252B, and is prevented from being discharged to the outside of the communication portion 230b.

  Since the first filter 252A removes only the soap base in the grease and allows the oil to pass therethrough, a coarse felt is used. However, the oil in the reduction chamber 30a gradually permeates and the communication portion There is a case of entering into 230b. In this case, the uneven portion 230g provided on the inner surface of the communication portion 230b prevents oil from propagating through the inner surface of the communication portion 230b. Therefore, it is possible to suppress the oil content in the grease from reaching the second filter 252B and to prevent the grease from being discharged to the outside.

  Next, a third embodiment will be described with reference to FIG. Since the hammer drill according to the present embodiment is the same as the first embodiment except for the configuration related to the communication portion forming portion 330B, the description thereof is omitted.

  As shown in FIG. 5, the communication portion forming portion 330 </ b> B provided in the support member 30 </ b> A in the gear housing 30 has an inlet 330 c which is an opening opening to the deceleration chamber 30 a and the motor housing 20 communicating with the outside air. An outlet 330d that opens inside is defined, and a communication portion 330b that connects the inlet 330c and the outlet 330d is formed. In the vicinity of the outlet 330d in the communication portion 330b, a groove portion 330e is formed over the inner periphery of the communication portion 330b. Further, the opening diameter of the inlet 330c is about half that of the inner diameter of the communication portion 330b.

  A communication path forming component 351 is inserted into the communication portion 330b. The communication path forming component 351 includes a first head 351A-1 having a smaller diameter than the opening diameter of the inlet 330c and one end protruding from the inlet 330c into the deceleration chamber 30a, and the first head 351A-1. A second head 351A-2 that is connected to the end side and has a diameter smaller than the inner diameter of the communication portion 330b and larger than the opening diameter of the inlet 330c is provided. The communication path forming component 351 is further provided with a body 351E having a diameter larger than that of the inside of the communication part 330b and positioned at the other end of the second head 351A-2, and at the other end of the body 351E. A flange portion 351F that is fitted into the groove portion 330e is provided. The communication path forming component 351 including these is made of an oil-resistant rubber material.

  Since the communication path forming component 351 is made of a rubber material, the communication path forming component 351 can be deformed and easily inserted into the communication portion 330b, and the flange portion 351F can be easily fitted into the groove portion 330e. . Even after the communication path forming component 351 is fitted into the communication portion 330b, the body portion 351E is in close contact with the inner surface of the communication portion 330b due to the elastic force of the rubber material. Therefore, it is difficult for a gap to be formed between the trunk portion 351E and the communication portion 330b, and it is possible to suppress the leakage of grease from this point, and it is difficult for deviation to occur.

  Further, the flange portion 351F is fitted into the groove portion 330e, whereby the communication path forming component 351 can be positioned in the communication portion 330b. As a result, a communication path 353, which will be described later, constituted by the communication path forming component 351 and the inner surface of the communication portion 330b can be suitably and uniformly sized.

  A perforation 351c is provided inside the communication path forming component 351 and has an opening on the other end side of the body portion 351E, and is drilled toward the second head portion 351A-2 to the substantially central portion of the second head portion 351A-2. ing. In the second head portion 351A-2, a side hole 351b penetrating the second head portion 351A-2 is bored substantially orthogonally to the bore hole 351c from the inside of the bore hole 351c toward the inner surface of the communication portion 330b. Therefore, there is a bent portion where the side holes 351b and the perforations 351c are continuous. Since the second head 351A-2 is formed smaller than the inner diameter of the communication portion 330b, an annular gap 351a is formed between the inner surface of the communication portion 330b and the second head 351A-2 from the inlet 330c. . Since the side hole 351b is open on the surface facing the inner surface of the communication portion 330b of the second head 351A-2, the side hole 351b communicates with the gap 351a. At this time, since the side hole 351b opens on the inner surface that defines the gap 351a, a bent portion exists at a location where the gap 351a and the side hole 351b are continuous. A communication passage 353 is formed on the upstream side of the gap 351a and in the order of the side hole 351b and the perforation 351c. Since the communication path forming component 351 is made of rubber as described above, complicated paths of these communication paths 353 are easily formed.

  The first head portion 351A-1 projects in the deceleration chamber 30a from the inlet 330c in a state where the communication path forming component 351 is disposed at a predetermined position determined by the fitting of the groove portion 330e and the flange portion 351F. Therefore, the opening cross-sectional area of the inlet 330c is small.

  A first collision portion 351B is defined at a position where the second head 351A-2 intersects with the first head 351A-1, and is colliding when the fluid flowing in from the inlet 330c flows into the gap 351a. Since the trunk 351E has a larger diameter than the second head 351A-2, there is a step at the boundary between the second head 351A-2 and the trunk 351E. Moreover, since the trunk | drum 351E is contact | abutting with the communication part 330b inner surface, it becomes a bag path-like body in the level | step-difference part of the boundary of 2nd head 351A-2 and the trunk | drum 351E, and this level | step-difference part is set to 2nd collision part 351C. Stipulate. The fluid flowing in the gap 351a once collides with the vicinity of the second collision portion 351C and then flows into the side hole 351b orthogonal to the flow direction in the gap 351a. A surface of the inner surface of the hole 351c that faces the opening of the side hole 351b is defined as a third collision portion 351D. The fluid that flows in the side hole 351b collides with the third collision portion 351D, and then the fluid flows in the perforation 351c.

  When the air in the deceleration chamber 30a is discharged into the atmosphere through the communication portion 330b due to the pressure increase in the deceleration chamber 30a as described above, the air first flows into the communication portion 330b from the inlet 330c. At this time, since the opening cross-sectional area of the inlet 330c is small, the flow velocity of the air passing through the inlet 330c is increased. In this state, the flow collides with the first collision portion 351B to disturb the flow, and the grease component contained in the air adheres to the first collision portion 351B to the third collision portion 351E. Therefore, the grease component is suppressed from being discharged to the outside from the communication portion 330b. In addition, the communication path 353 suppresses leakage of liquid grease through the inner wall surface of the communication path 353 due to its fluidity, surface tension, and the like by a complicated path having bent portions and the like.

  Next, a fourth embodiment will be described with reference to FIG. Since the hammer drill according to the present embodiment is the same as the first embodiment except for the configuration related to the communication portion forming portion 430B, the description thereof is omitted.

  As shown in FIG. 6, the communication portion forming portion 430B provided on the support member 30A in the gear housing 30 has an inlet 430c that is an opening opening to the reduction chamber 30a and the motor housing 20 that is in communication with the outside air. An outlet 430d that is opened inside is defined, and a communication portion 430b that connects the inlet 430c and the outlet 430d is formed. The opening diameter of the inlet 430c is set smaller than the opening diameter of the outlet 430d and the inner diameter of the communication portion 430d. Further, in the vicinity of the outlet 430d, a groove 430e is formed in the inner periphery thereof.

  A communication path forming component 451 is inserted into the communication portion 430b. The communication path forming component 451 is substantially cylindrical and has a trunk portion 451A whose outer diameter when not mounted is larger than the inner diameter of the communication portion 430b and an end portion on the outlet 430d side of the trunk portion 451A and is fitted into the groove portion 430e. Part 451D, and is made of an oil-resistant rubber material. Since the communication path forming component 451 is made of a rubber material, the communication path forming component 451 can be deformed and easily inserted into the communication portion 430b, and the flange portion 451D can be easily fitted into the groove portion 430e. . Even after the communication path forming component 451 is fitted into the communication portion 430b, the body portion 451A is in close contact with the inner surface of the communication portion 430b due to the elastic force of the rubber material. Therefore, it is difficult for a gap to be formed between the trunk portion 451A and the communication portion 430b, and it is possible to suppress the leakage of grease from this portion, and it is difficult for deviation to occur.

  Further, the flange portion 451D is fitted into the groove portion 430e, whereby the communication path forming component 451 can be positioned in the communication portion 430b. As a result, a communication path 453, which will be described later, constituted by the communication path forming component 451 and the inner surface of the communication portion 430b can be made suitable and uniform.

  A perforation 451b is formed in the body 451A with an opening at one end surface that is the inlet 430c side end and the other end surface that is the outlet side end. The communication path forming component 451 is inserted into the communication portion 430b so that the projection in the entrance / exit direction of the opening 430c side opening of the perforation 451b and the projection in the entrance / exit direction of the entrance 430c opening do not overlap. In addition, a predetermined gap 451a is formed between one end face of the body 451A and the communication part forming part 430B around the inlet 430c, and the gap 451a and the perforation 451b communicate with each other. Therefore, since the fluid flow direction in the inlet 430c and the fluid flow direction in the gap 451a are substantially orthogonal to each other, a portion where the inlet 430c and the gap 451a are continuous is provided. In addition, since the fluid flow direction in the gap 451a and the flow direction in the perforation 451b are substantially perpendicular to each other, the continuous portion between the gap 451a and the perforation 451b is also provided with a bent portion. A communication path 453 is formed with the gap 451a as the upstream side and the perforation 451b as the downstream side. Since the communication path forming component 451 is made of rubber as described above, complicated paths of these communication paths 453 are easily formed.

  A first collision object 451B is defined at a position facing the inlet 430c on one side surface of the body 451A, and the fluid flowing in from the inlet 430c can collide. A second collision portion 451C is defined on the inner surface of the communication portion 430b that defines the gap 451a in the vicinity of the perforation 451b. When the fluid that has flowed through the gap 451a flows into the perforation 451b, it once collides with the vicinity of the second collision portion 451C and then flows into the perforation 451b.

  When the air in the deceleration chamber 30a is discharged into the atmosphere through the communication portion 430b due to the pressure increase in the deceleration chamber 30a as described above, first, the air flows into the communication portion 430b from the inlet 430c. At this time, since the opening cross-sectional area of the inlet 430c is small, the flow velocity of the air passing through the inlet 430c is increased. In this state, the flow collides with the first collision portion 451B to disturb the flow, and the grease component contained in the air adheres to the first collision portion 451B and the second collision portion 451C. Therefore, it is suppressed that a grease component is discharged | emitted from the communication part 430b outside. In addition, the communication path 453 suppresses leakage of liquid grease through the inner wall surface of the communication path 453 due to its fluidity, surface tension, and the like due to a complicated path having bent portions and the like.

  Although the filter is not used in the fourth embodiment, a filter may be used in the vicinity of the entrance / exit of the communication portion 453 as in the first embodiment. In this case, the grease component is further suppressed from being discharged to the atmosphere.

  Next, a fifth embodiment will be described with reference to FIG. Since the hammer drill according to the present embodiment is the same as the first embodiment except for the configuration related to the communication portion forming portion 530B, the description thereof is omitted.

  As shown in FIG. 7, the communication portion forming portion 530B provided on the support member 30A in the gear housing 30 has an inlet 530c that is an opening that opens to the deceleration chamber 30a and the motor housing 20 that communicates with the outside air. An outlet 530d that is open to the inside is defined, and a communication portion 530b that connects the inlet 530c and the outlet 530d is formed. In the vicinity of the outlet 530d in the communication part 530b, a groove part 530e is formed over the inner periphery of the communication part 530b. Further, the opening diameter of the inlet 530c is about half that of the inner diameter of the communication portion 530b.

  A felt filter 552A having a coarse mesh is inserted on the most entrance side of the continuous pain portion 530b. The filter 552A has a donut shape, and the outer diameter is substantially the same as or slightly larger than the inner diameter of the communication portion 530b, and the inner diameter is substantially the same as the diameter of the first head 551A-1 described later. Further, the filtration performance is such that the soap group in the grease can be filtered, but most of the oil component passes therethrough.

  A communication path forming component 551 is inserted on the outlet 530D side of the filter 552A. The communication path forming component 551 includes a first head 551A-1 having a smaller diameter than the opening diameter of the inlet 530c and one end protruding from the inlet 530c into the deceleration chamber 30a, and the first head 551A-1. A second head portion 551A-2 that is connected to the end side and has a diameter smaller than the inner diameter of the communication portion 530b and larger than the opening diameter of the inlet 530c is provided. The communication path forming component 551 further includes a body portion 551D having a larger diameter than the inside diameter of the communication portion 530b when located on the other end side of the second head portion 551A-2. A flange portion 551E is provided to be fitted into the groove portion 530e. The communication path forming component 551 including these is made of an oil-resistant rubber material.

  Since the communication path forming component 551 is made of a rubber material, the communication path forming component 551 can be deformed and easily inserted into the communication portion 530b, and the flange portion 551E can be easily fitted into the groove portion 530e. . Further, even after the communication path forming component 551 is fitted into the communication portion 530b, the body portion 551D is in close contact with the inner surface of the communication portion 530b by the elastic force of the rubber material. Therefore, it is difficult for a gap to be formed between the body portion 551D and the communication portion 530b, it is possible to suppress the leakage of the grease from this point, and it is difficult for deviation to occur.

  Further, the flange portion 551E is fitted into the groove portion 530e, whereby the communication path forming component 551 can be positioned in the communication portion 530b. As a result, a communication path 553, which will be described later, constituted by the communication path forming component 551 and the inner surface of the communication portion 530b can be made to have a suitable and uniform size.

  Further, since the second head portion 551A-1 abuts against the filter 552A and is urged, the filter 552A is held and displacement is difficult to occur, and a gap or the like is formed between the filter 552A and the communication portion 530b. Being suppressed.

  A perforation 551c is provided inside the communication path forming component 551, and has an opening on the other end side of the body portion 551D. The perforation 551c is drilled toward the second head portion 551A-2 to the substantially central portion of the second head portion 551A-2. ing. In the second head portion 551A-2, a side hole 551b penetrating the second head portion 551A-2 is bored substantially perpendicularly to the bore hole 551c from the inside of the bore hole 551c toward the inner surface of the communication portion 530b. Therefore, a bent portion exists at a place where the side hole 551b and the perforation 551c are continuous. Since the outer diameter of the second head portion 551A-2 is smaller than the inner diameter of the communication portion 530b, the second head portion 551A-2 is annular between the communication portion 530b between the side surface position of the outlet 530d of the filter 552A and the vicinity of the side hole 551b and the communication path forming component 551. The gap 551a is formed. Since the side hole 551b is open on the surface facing the inner surface of the communication portion 530b of the second head 551A-2, the side hole 551b communicates with the gap 551a. At this time, since the side hole 551b is opened on the inner surface that defines the gap 551a, there is a bent portion where the gap 551a and the side hole 551b are continuous. A communication passage 553 is formed in which the gap 551a is the upstream side, and the side holes 551b and the perforations 551c are arranged downstream in this order. Since the communication path forming component 551 is made of rubber as described above, the complicated paths of these communication paths 553 are easily formed.

  The first head portion 551A-1 penetrates the opening of the filter 552A in a state where the communication path forming component 551 is disposed at a predetermined position determined by the fitting of the groove portion 530e and the flange portion 551E, and a part of the first head portion 551A-1 It protrudes from the inlet 530c into the deceleration chamber 30a. As a result, the opening cross-sectional area of the inlet 530c is reduced, and the projection of the inlet 530c opening in the entrance / exit direction does not overlap with the projection of the gap 551a in the entrance / exit direction. Therefore, the fluid that has flowed into the filter 552A is not in the inlet / outlet direction, which is the shortest distance for passing through the filter 552A, in the filter 552A, but in the direction from the downstream opening of the inlet 530c toward the upstream opening of the gap 551a. Will flow. Thereby, the filtration performance in filter 552A increases, and it becomes possible to smear a grease component more suitably.

  Since the outer diameter of the trunk portion 551D is larger than the second head portion 551A-2, there is a step at the boundary between the second head portion 551A-2 and the trunk portion 551D. Further, since the body portion 551D is in contact with the inner surface of the communication portion 530b, a stepped portion at the boundary between the second head portion 551A-2 and the body portion 5D51D forms a bag-like body, and this step portion is connected to the first collision portion 551B. Stipulate. The fluid flowing in the gap 551a once collides with the vicinity of the first collision portion 551B and then flows into the side hole 551b orthogonal to the flow direction in the gap 551a. A surface of the inner surface of the hole 551c facing the opening of the side hole 551b is defined as a second collision portion 351C. The fluid that flows in the side hole 351b collides with the second collision portion 351C, and then the fluid flows in the perforation 351c.

  When the air in the deceleration chamber 30a is discharged into the atmosphere through the communication portion 530b due to the pressure increase in the deceleration chamber 30a as described above, first, the air flows into the filter 552A in the communication portion 530b from the inlet 530c. . By passing this air through the filter 552A, a soap base having a relatively high viscosity and large particles in the form of solid or droplets in the grease is scrubbed. Therefore, the oil and air in the grease pass through the filter 552A.

  Air or the like that has passed through the filter 552A flows into the communication path 553. In the communication passage 553, a plurality of bent portions are formed in the middle of the passage configuration, and a first collision portion 551B and a second collision portion 551C which are collision portions are provided here. Therefore, the air that still contains the grease component that has passed through the first filter 552A collides with the first collision part 551B and the second collision part 551C, and the flow is disturbed. The grease component contained in the air is It adheres to 551B and the 2nd collision part 551C. In addition, the communication passage 553 suppresses leakage of liquid grease through the inner wall surface of the communication passage 553 due to its fluidity and surface tension due to a complicated path having bent portions and the like.

  Next, a sixth embodiment will be described with reference to FIG. Since the hammer drill according to the present embodiment is the same as the first embodiment except for the configuration related to the communication portion forming portion 630B, the description thereof is omitted.

  As shown in FIG. 8, the communication portion forming portion 630B provided on the support member 30A in the gear housing 30 has an inlet 630c that is an opening that opens to the deceleration chamber 30a and the motor housing 20 that is in communication with the outside air. An outlet 630d opened inside is defined, and a communication portion 630b that connects the inlet 630c and the outlet 630d is formed. In the vicinity of the outlet 630d in the communication part 630b, a groove part 630e is formed over the inner periphery of the communication part 630b. Further, the opening diameter of the inlet 630c is about half that of the inner diameter of the communication portion 630b.

  A communication path forming component 651 is inserted into the communication portion 630b. The communication path forming component 651 includes a first head 651A-1 having a smaller diameter than the opening diameter of the inlet 630c and one end protruding from the inlet 630c into the deceleration chamber 30a, and the first head 651A-1. A second head 651A-2 that is connected to the end side and has a diameter smaller than the inner diameter of the communication portion 630b and larger than the opening diameter of the inlet 630c is provided. The communication path forming component 651 is further provided with a trunk 651E having a larger diameter than the inner diameter of the communication part 630b when positioned on the other end of the second head 651A-2, and at the other end of the trunk 651E. A flange 651F is provided to be fitted into the groove 630e. The communication path forming component 651 including these is made of an oil-resistant rubber material.

  Since the communication path forming component 651 is made of a rubber material, the communication path forming component 651 can be deformed and easily inserted into the communication portion 630b, and the flange portion 651F can be easily fitted into the groove portion 630e. . Even after the communication path forming component 651 is fitted into the communication portion 630b, the communication path forming component 651 is in close contact with the inner surface of the communication portion 630b by the elastic force of the rubber material. Therefore, it is difficult for a gap to be generated between the communication path forming component 651 and the communication portion 630b, and it is possible to suppress the leakage of grease from this interval.

  Further, the flange portion 651F is fitted into the groove portion 630e, whereby the communication path forming component 51 can be positioned in the communication portion 630b. As a result, a communication path 653, which will be described later, constituted by the communication path forming component 651 and the inner surface of the communication portion 630b can be made suitable and uniform in size, and misalignment hardly occurs.

  A perforation 651c is provided inside the communication path forming component 651 and has an opening on the other end side of the body portion 651E, and is drilled toward the second head 651A-2 side to a substantially central portion of the second head 651A-2. ing. In the second head 651A-2, a side hole 651b penetrating through the second head 651A-2 is bored substantially orthogonally to the bore 651c from the inside of the bore 651c toward the inner surface of the communication portion 630b. Therefore, a bent portion exists at a place where the side hole 651b and the perforation 651c are continuous. Since the outer diameter of the second head portion 651A-2 is smaller than the inner diameter of the communication portion 630b, an annular gap 651a is formed between the inner surface of the communication portion 630b and the second head portion 651A-2 from the inlet 630c. Yes. Since the side hole 651b opens in a surface facing the inner surface of the communication portion 630b of the second head 651A-2, the side hole 651b communicates with the gap 651a. At this time, since the side hole 651b is opened on the inner surface that defines the gap 651a, there is a bent portion where the gap 651a and the side hole 651b are continuous. A communication passage 653 is formed on the upstream side of the gap 651a and in the order of the side hole 651b and the perforation 651c. Since the communication path forming component 651 is made of rubber as described above, complicated paths of these communication paths 653 are easily formed.

  A part of the first head portion 651A-1 is disposed in a predetermined position determined by the fitting of the groove portion 630e and the flange portion 651F, and a part of the first head portion 651A-1 enters the deceleration chamber 30a from the inlet 630c. Since it protrudes, the opening cross-sectional area of the inlet 630c is small.

  A first collision portion 651B is defined at a position where the second head portion 651A-2 intersects with the first head portion 651A-1, and collides when the fluid flowing in from the inlet 630c flows into the gap 651a. Since the outer diameter of the trunk portion 651E is larger than the second head portion 651A-2, there is a step at the boundary between the second head portion 651A-2 and the trunk portion 651E. Moreover, since the trunk | drum 651E is contact | abutting with the communicating part 630b inner surface, it becomes a bag small path-like body in the level | step-difference part of the boundary of 2nd head 651A-2 and the trunk | drum 651E, and this level | step-difference part is set to the 2nd collision part 651C. Stipulate. The fluid flowing in the gap 651a once collides with the vicinity of the second collision portion 651C and then flows into the side hole 651b orthogonal to the flow direction in the gap 651a. A surface of the inner surface of the hole 651c that faces the opening of the side hole 651b is defined as a third collision portion 651D. The fluid that flows in the side hole 651b collides with the third collision portion 651D, and then the fluid flows in the perforation 651c.

  A filter 652B is fitted into the groove 630e and provided in the communication portion 630b on the outlet 603D side of the communication path forming component 651. The filter 652B is made of a fine felt and has a filtration performance capable of filtering the oil in the grease. In addition, since the filter 652B is fitted in the groove 630e, the communication path forming component 651 is urged and held toward the inlet 630c, and displacement or the like hardly occurs.

  When the air in the deceleration chamber 30a is discharged into the atmosphere through the communication portion 630b due to the pressure increase in the deceleration chamber 30a as described above, first, the air enters the communication passage 653 in the communication portion 630b from the inlet 630c. Inflow. In the communication path 653, a plurality of bent portions are formed in the middle of the path configuration, and a first collision part 651B to a third collision part 651D which are collision parts are provided here. Therefore, the air containing the grease component collides with the first collision part 651B to the third collision part 651D and the flow is disturbed, and the sprayed or droplet-like grease component contained in the air becomes the first collision part 651B. -Adheres to the third collision part 651D.

  After passing through the communication path 653, air or the like flows into the filter 652B. Since the filter 652B uses felt with high filtration performance, it is also possible to filter oil contained in the air. The filter 652B removes oil that has passed through the communication path 653 from the filter 652B. Suppressing discharge to the outside. Therefore, the grease contained in the air discharged from the deceleration chamber 30a to the outside air is removed before passing through the filter 652B, and is prevented from being discharged to the outside from the communication portion 630b. In addition, the communication path 653 suppresses leakage of liquid grease through the inner wall surface of the communication path 53 due to its fluidity, surface tension, and the like due to a complicated path having bent portions and the like.

  In the sixth embodiment, a filter coarser than the filter 652B may be provided in the communication portion 630b in the vicinity of the inlet 630c, and the soap group in the grease component may be removed. In this case, the grease is further suppressed from being discharged to the atmosphere.

  The power tool of the present invention is not limited to the above-described embodiment, and various modifications and improvements can be made within the scope described in the claims. For example, although the communication path forming component is made of rubber, the present invention is not limited to this, and a general resin having oil resistance can be used. In addition to the resin, for example, it may be made of metal. By using metal communication path forming parts, it is only necessary to press-fit when fixing this to the communication part, and it is not necessary to form a groove in the communication part, and the manufacturing process can be simplified. It is.

  The filter is preferably made of felt, but is not limited to this, and any member having filtration performance can be used. In the first embodiment and the second embodiment including the first filter and the second filter, the first filter is provided in the vicinity of the inlet in the communication portion, and the second filter is provided in the vicinity of the outlet. For example, the first filter may be provided on the side wall surface of the deceleration chamber of the communication portion forming portion so as to cover the inlet. Similarly, you may provide a 2nd filter in the motor housing side wall surface of a communication part formation part so that an exit may be covered. In this case, the communication part can be blocked by at least the first filter and the second filter, so that the effect as a filter can be achieved, and a groove for fixing the first filter and the second filter needs to be formed in the communication part. It becomes possible to eliminate the manufacturing process.

  Further, in the first embodiment and the third to sixth embodiments, the communication path is configured to include a gap defined by the communication portion and the communication portion forming component, but is not limited thereto. In addition, it may be constituted only by the perforations formed in the communication part forming component.

1 is an overall cross-sectional view of a hammer drill according to a first embodiment. Sectional drawing showing the II-II cross section of FIG. 1 which concerns on 1st embodiment. Sectional detail drawing showing the III-III cross section of FIG. 2 which concerns on 1st embodiment. Sectional detail surface drawing which concerns on 2nd embodiment. Sectional detail drawing which concerns on 3rd embodiment. Sectional detail drawing concerning 4th embodiment. FIG. 10 is a detailed sectional view according to a fifth embodiment. FIG. 10 is a detailed sectional view according to a sixth embodiment.

Explanation of symbols

1 .. Hammer drill 2... Motor pinion gear 10.. Handle part 11.. Power cable 12. Trigger 13.. Side handle 20 .. Motor housing 21 .. Output shaft 22 .. Motor pinion gear 30. · Support member 30B · · Communication portion forming portion 30a · · Reduction chamber 30b · · Communication portion 30c · · Inlet 30d · · Outlet 30e · · Groove portion 31 · · First gear 32 · · Intermediate shaft 32A · · Gear portion 32B · · Bearing 33 · · Second gear 34 · · Cylinder 35 · · Tool holder 36 · · Clutch 37 · · Change lever 40 · · Motion conversion portion 40A · · Arm 41 · · Piston pin 42 · · Piston 43 · · Batter 44 ·· Air chamber 45 · · Intermediate 51 · · Communication passage forming part 51A · · Head 51B · · First collision part 51C · · · Second collision part 1D ·· Body 51E · · Gutter 51a · · Clearance 51b · · Side hole 51c · · Perforation 52A · · First filter 52B · · Second filter 53 · · Communication passage 60 · · Tip tool 71 · · Oil seal 72-74 ... O-ring

Claims (7)

A housing in which a mechanism chamber is partially defined, and a lubricant is sealed inside the mechanism chamber ;
An electric motor housed in the housing;
A power transmission mechanism provided in the mechanism chamber and configured to change a speed of rotation of the electric motor;
A communication portion forming portion that is provided in the housing and forms a communication portion having an inlet opening to the mechanism chamber and an outlet communicating with the inlet;
A first filter and a second filter that block an entrance / exit direction of the communication portion;
The power tool, wherein the second filter is provided on the outlet side of the first filter. A cylinder rotatably supported in the housing and capable of holding a tip tool;
The electric power tool according to claim 1, further comprising a rotation transmission mechanism that transmits the rotation of the electric motor to the cylinder and rotates the cylinder about its axis.   The power tool according to claim 1, wherein the second filter has higher filtering performance than the first filter.   The electric power tool according to any one of claims 1 to 3, wherein the first filter and the second filter are formed of a felt base material.   The first and second filter position fixing parts for fixing the positions of the first filter and the second filter are provided in the communication part. Item 5. The electric tool according to any one of Items 4. A communication path forming component that is inserted in the communication section between the first filter and the second filter and forms a communication path that communicates with the communication section between the inside and outside of the mechanism;
At least one of the communication path forming component and the communication part forming part is provided with a collision part that defines a part of the communication path, and flows into the communication path from the inlet through the first filter. The electric tool according to any one of claims 1 to 5, wherein the air or lubricant that has collided with the collision portion.   The electric tool according to any one of claims 1 to 5, wherein the communication portion has an inner wall surface formed alternately in an uneven shape in a direction from the inlet toward the outlet.

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