Electric working machine

Abstract

The present invention provides an electric working machine, which can prevent or suppress the transmission of vibrations equal to or greater than those in the past by using fewer parts and fewer assembly hours than in the past. A hammer drill (1A) has a motor (40) as a driving source, and is equipped with a drill bit (3) driven by a driving force output from the motor (40). The hammer drill (1A) has a main body shell (10) and a handle shell (20) that form at least a part of a housing (2), and the main body shell (10) and the handle shell (20) are connected via an elastomer (30) in a manner that allows relative movement. The elastomer (30) is a part of a continuous resin cover (31) that is formed on the main body shell (10) and the handle shell (20) by double-layer molding and covers the surface of the main body shell (10) and the handle shell (20).

Description

Technical Field

[0001] The present invention relates to an electric working machine, and more particularly to a vibration-proof structure in an electric working machine. Background Art

[0002] Nowadays, various electric working machines using motors as driving sources are known. The rotational motion of the output shaft of the motor provided in these electric working machines is amplified or converted into reciprocating motion and then transmitted to the tool tip.

[0003] Patent document 1 describes a hammer drill as one of the above-mentioned electric working machines. The hammer drill described in patent document 1 has a main body, which includes: a housing that accommodates a motor, a transmission mechanism that transmits the driving force output from the motor to the front end tool, and a handle held by an operator. In addition, an elastic body is provided between the housing and the handle, and the elastic body prevents or suppresses the vibration generated in the housing from being transmitted to the handle. In this way, the handle connected to the housing that accommodates the vibration source via the elastic body for preventing or suppressing the transmission of vibration is sometimes called a "vibration-proof handle".

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2007-331072 Summary of the invention

[0007] Problems to be solved by the invention

[0008] In the hammer drill described in Patent Document 1, vibration transmission is prevented or suppressed by an elastic body provided between the housing and the handle, which is independent of the housing and the handle. Therefore, the number of parts increases, the assembly time also increases, and the structure becomes complicated and the product becomes larger.

[0009] An object of the present invention is to realize an electric working machine which reduces the number of parts and simplifies the structure to achieve a reduction in assembly man-hours and a reduction in size, and prevents or suppresses the transmission of vibrations equal to or greater than those of the related art.

[0010] Solutions to Solve Problems

[0011] In one embodiment of the present invention, an electric working machine comprises a first component and a second component forming at least a portion of a housing, wherein the first component and the second component are connected via an elastic body so as to be relatively movable. The elastic body is a portion of a continuous resin cover formed on the first component and the second component by double-layer molding and covering the surfaces of the first component and the second component.

[0012] In another embodiment of the present invention, the electric working machine has a first component and a second component that form at least a portion of a housing, and the first component and the second component are connected via a connecting portion and an elastic body. The connecting portion includes: a first end portion connected to the first component; a second end portion connected to the second component; and an intermediate portion connecting the first end portion and the second end portion. The first end portion, the second end portion, and the intermediate portion are integrally formed, and the intermediate portion is weaker than the first end portion and the second end portion. The elastic body is a portion of a continuous resin cover that is formed on the first component and the second component by double-layer molding and covers the surfaces of the first component and the second component across the connecting portion.

[0013] Effects of the Invention

[0014] According to the present invention, an electric working machine is realized which reduces the number of assembly steps and reduces the size by reducing the number of parts or simplifying the structure, and prevents or suppresses the transmission of vibrations equal to or greater than those of conventional machines. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a cross-sectional view of the hammer drill according to the first embodiment.

[0016] Figure 2 yes Figure 1 An enlarged cross-sectional view of the portion A surrounded by a single-dot chain line circle.

[0017] Figure 3 yes Figure 1 Another enlarged cross-sectional view of the portion A surrounded by a single-dot chain line circle.

[0018] Figure 4 It is an explanatory diagram showing the molding process of the main body case and the handle case.

[0019] Figure 5 It is an explanatory diagram showing the molding process of the resin cover.

[0020] Figure 6 It is a cross-sectional view of a hammer drill according to a second embodiment.

[0021] Figure 7 yes Figure 6 An enlarged cross-sectional view of the portion B surrounded by a single-dot chain circle.

[0022] Figure 8 yes Figure 6 Another enlarged cross-sectional view of the portion B surrounded by a single-dot chain circle.

[0023] Fig. 9 It is a cross-sectional view showing an example of an electric working machine to which the present invention is applied.

[0024] Fig.10 It is a cross-sectional view showing another example of the electric working machine to which the present invention is applied.

[0025] Fig.11 It is a partial cross-sectional view of a hammer drill according to a third embodiment.

[0026] Fig.12 (a) is Fig.11 (b) is an enlarged cross-sectional view of the C portion surrounded by a dot-dashed circle. (c) is an explanatory view showing another embodiment of the fracture state of the middle portion.

[0027] Fig.13 It is an explanatory diagram showing a modified example of the connection structure between the first member and the second member.

[0028] Fig.14 (a) means along Fig.13 (b) is a diagram showing a cross section along line XX in FIG. Fig.13 An illustration of the cross section taken along line YY in FIG.

[0029] Fig.15 It is an explanatory diagram showing another modified example of the connection structure between the first member and the second member.

[0030] Fig.16 (a) to (d) are explanatory diagrams showing different modified examples of the connection portion. DETAILED DESCRIPTION

[0031] (First Embodiment)

[0032] Hereinafter, an example of an embodiment of the electric working machine of the present invention will be described in detail with reference to the drawings. In the following description, the same reference numerals are used for the same or substantially the same configurations, and duplicate descriptions are appropriately omitted.

[0033] The electric working machine of the present embodiment is a hammer drill having a plurality of switchable action modes. The hammer drill of the present embodiment has at least three action modes, namely, a "drilling mode", a "hammering mode" and a "hammer drilling mode". In the drilling mode, only a rotational force is applied to the front end tool, and in the hammering mode, only an impact force is applied to the front end tool. On the other hand, in the hammer drilling mode, both a rotational force and an impact force are applied to the front end tool.

[0034] As an example of a front end tool mounted on a hammer drill, a drill bit can be cited. The drill bit is used, for example, when drilling a hole in concrete or stone. However, the front end tool mounted on a hammer drill is not limited to the drill bit, and the front end tool mounted on the hammer drill is selected from a plurality of front end tools according to the object, the type of operation on the object, and the like.

[0035] like Figure 1 As shown, the hammer drill 1A of this embodiment includes a main body housing 10 as a first component and a handle housing 20 as a second component, and the main body housing 10 and the handle housing 20 form at least a part of the outer shell 2 of the hammer drill 1A. The main body housing 10 and the handle housing 20 are connected to each other via an elastic body 30 so as to be relatively movable. The connection structure of the main body housing 10 and the handle housing 20 will be described in detail later.

[0036] The main body housing 10 accommodates a motor 40 as a driving source of a tip tool (the drill bit 3 in this embodiment) and a transmission mechanism 41 for transmitting the driving force output from the motor 40 to the drill bit 3. On the other hand, the handle housing 20 forms a handle 21 gripped by an operator.

[0037] A trigger lever 22 is provided at the upper portion of the handle housing 20, and a battery mounting portion 23 is provided at the lower portion of the handle housing 20. When the trigger lever 22 is pulled under a predetermined condition, the battery (battery pack 24) mounted on the battery mounting portion 23 supplies power to the motor 40 to operate the motor 40. That is, the motor 40 outputs a driving force.

[0038] The motor 40 housed in the lower part of the main body housing 10 is a brushless motor, and a cooling fan 42 and a pinion 43 are provided on its output shaft (output main shaft). The pinion 43 meshes with a bevel gear 44 as an input part of the transmission mechanism 41. The transmission mechanism 41 includes an intermediate shaft 45 extending in a direction intersecting the output shaft, and the bevel gear 44 is fixed to the end of the intermediate shaft 45. A conversion mechanism for converting the rotational motion of the intermediate shaft 45 into reciprocating motion is provided on the intermediate shaft 45. The conversion mechanism includes an inner ring, an outer ring, a rolling element, and a connecting rod. The inner ring is fixed to the intermediate shaft 45, and the outer ring is arranged around the inner ring in a manner of surrounding the inner ring. In addition, the rolling element is sandwiched between the inner ring and the outer ring, and the connecting rod protrudes from the outer peripheral surface of the outer ring toward the radial outer side of the outer ring. Cross-sectional arc-shaped grooves that intersect each other are formed on the outer peripheral surface of the inner ring and the inner peripheral surface of the outer ring. A part of the rolling element is fitted into the groove formed in the inner ring, and the other part is fitted into the groove formed in the outer ring. That is, the inner ring and the outer ring are connected to each other via rolling elements so as to be relatively rotatable.

[0039] Furthermore, a clutch is provided on the intermediate shaft 45, and the clutch is switched between an engaged state in which power is transmitted from the intermediate shaft 45 to the conversion mechanism and a released state in which power is not transmitted from the intermediate shaft 45 to the conversion mechanism. The clutch cannot rotate relative to the intermediate shaft 45, and can move forward and backward along the intermediate shaft 45. When the clutch retreats to a predetermined position (approaching the inner ring), the intermediate shaft 45 and the inner ring are connected via the clutch, and power is transmitted from the intermediate shaft 45 to the inner ring. On the other hand, when the clutch advances to a predetermined position (leaving the inner ring), the connection between the intermediate shaft 45 and the inner ring is released, and the power transmission from the intermediate shaft 45 to the inner ring is cut off.

[0040] The movement (switching) of the clutch as described above is achieved by the operator switching the operation mode. When the clutch is in the engaged state, if the intermediate shaft 45 rotates, the inner ring rotates. Then, the outer ring rolls along the surface of the inner ring, and the connecting rod swings back and forth.

[0041] A cylinder 46 is provided above the intermediate shaft 45 and parallel to the intermediate shaft 45. A ring gear is provided on the outer periphery of the cylinder 46, and the ring gear can move forward and backward along the cylinder 46, and switch between a connected state in which the rotation of the intermediate shaft 45 is transmitted to the cylinder 46 and a non-connected state in which the rotation of the intermediate shaft 45 is not transmitted to the cylinder 46. The switching of the ring gear is realized according to the mode switching operation of the operator. In addition, the ring gear switched to the non-connected state rotates idly on the cylinder 46.

[0042] The cylinder 46 contains a piston, an impact piece, and an intermediate piece. The piston, the impact piece, and the intermediate piece are arranged in a row from the rear to the front, and an air chamber is provided between the piston and the impact piece. A retaining sleeve 47 is provided in front of the cylinder 46, and the rear end of the retaining sleeve 47 is fixed to the front end of the cylinder 46 in a manner that cannot rotate relative to each other. The root base of the drill bit 3 is inserted into the retaining sleeve 47, and the retaining sleeve 47 retains the root base of the inserted drill bit 3. Therefore, when the ring gear is switched to the connected state and the rotation of the intermediate shaft 45 is transmitted to the cylinder 46, the retaining sleeve 47 and the drill bit 3 retained by the retaining sleeve 47 rotate.

[0043] The back of the piston is rotatably connected to a connecting rod of a conversion mechanism. When the connecting rod swings back and forth, the piston reciprocates back and forth in the cylinder 46, and the pressure of the air chamber changes. Then, the impact piece is driven by the pressure change of the air chamber, and the impact piece hits the intermediate piece, and the intermediate piece hits the drill bit 3.

[0044] In this embodiment, when the drilling mode is selected by the mode switching operation performed by the operator, the clutch is released and the ring gear is connected. In this state, when the intermediate shaft 45 rotates, the inner ring of the conversion mechanism does not rotate, while the cylinder 46 rotates. Therefore, only the drill bit 3 held by the holding sleeve 47 is given a rotational force.

[0045] On the other hand, when the hammer mode is selected by the operator's mode switching operation, the clutch is in an engaged state and the ring gear is in a non-connected state. In this state, when the intermediate shaft 45 rotates, the inner ring of the conversion mechanism rotates, while the cylinder 46 does not rotate. Therefore, the piston reciprocates in the stationary cylinder 46, and only the drill bit 3 held in the holding sleeve 47 is given an impact force.

[0046] When the hammer drill mode is selected by the mode switching operation performed by the operator, the clutch is engaged and the ring gear is connected. In this state, when the intermediate shaft 45 rotates, the inner ring of the conversion mechanism rotates, and the cylinder 46 also rotates. Therefore, the piston reciprocates in the rotating cylinder 46, and both the rotational force and the impact force are applied to the drill bit 3 held by the holding sleeve 47.

[0047] Next, the connection structure of the main body housing 10 and the handle housing 20 will be described. As described above, the main body housing 10 and the handle housing 20 are connected via the elastic body 30. Figure 1 As shown, the handle housing 20 has two ends, each of which is connected to the main body housing 10 via an elastic body 30. Specifically, the handle housing 20 has an upper end 25 located near (above) the trigger lever 22 and a lower end 26 located near (in front of) the battery mounting portion 23. On the other hand, the main body housing 10 has an upper connecting portion 11 connected to the upper end 25 of the handle housing 20 and a lower connecting portion 12 connected to the lower end 26 of the handle housing 20. In addition, the upper end 25 of the handle housing 20 and the upper connecting portion 11 of the main body housing 10, and the lower end 26 of the handle housing 20 and the lower connecting portion 12 of the main body housing 10 are connected via an elastic body 30, respectively. As a result, the handle housing 20 and the main body housing 10 can move relative to each other. In other words, the handle housing 20 can move within a predetermined range relative to the main body housing 10.

[0048] like Figure 1As shown, the elastic body 30 that connects the handle housing 20 in a manner that allows it to move relative to the main body housing 10 is a part of a continuous resin cover 31 that is formed on the handle housing 20 and the main body housing 10 by double-layer molding and covers the surfaces of the handle housing 20 and the main body housing 10. That is, the upper end 25 of the handle housing 20 is connected to the upper connecting portion 11 of the main body housing 10 via a part of the continuous resin cover 31, and the lower end 26 of the handle housing 20 is connected to the lower connecting portion 12 of the main body housing 10 via another part of the continuous resin cover 31.

[0049] from Figure 1 It can be understood that a portion of the resin cover 31 sandwiched between the upper end 25 of the handle housing 20 and the upper connecting portion 11 of the main body housing 10 is one end of the resin cover 31. In addition, another portion of the resin cover 31 sandwiched between the lower end 26 of the handle housing 20 and the lower connecting portion 12 of the main body housing 10 is the other end of the resin cover 31. In the following description, the end of the resin cover 31 sandwiched between the upper end 25 of the handle housing 20 and the upper connecting portion 11 of the main body housing 10 is sometimes referred to as the "upper end 32", and the other end of the resin cover 31 sandwiched between the lower end 26 of the handle housing 20 and the lower connecting portion 12 of the main body housing 10 is sometimes referred to as the "lower end 33".

[0050] Next, the upper end portion 32 and the lower end portion 33 of the resin cover 31 will be described in detail. However, the upper end portion 32 and the lower end portion 33 have substantially the same shape and structure. Figure 2 , Figure 3 The shape and structure of the upper end portion 32 will be described in detail, and the shape and structure of the lower end portion 33 will also become clear.

[0051] like Figure 2 , Figure 3As shown, the upper end portion 32 includes: an annular clamping portion 32a, which is clamped between the end face 20a of the handle housing 20 and the end face 10a of the main body housing 10, which are opposite to each other; a handle housing side engaging portion 32b, which is located closer to the handle housing 20 side than the clamping portion 32a and engages with the engaging portion 27 formed on the surface of the handle housing 20; and a main body housing side engaging portion 32c, which is located closer to the main body housing 10 side than the clamping portion 32a and engages with the engaging portion 13 formed on the surface of the main body housing 10. In other words, the upper end portion 32 includes an annular clamping portion 32a, a handle housing side engaging portion 32b provided on one side of the clamping portion 32a, and a main body housing side engaging portion 32c provided on the other side of the clamping portion 32a. The handle housing side engaging portion 32b expands from one side of the clamping portion 32a toward the radial outer side of the clamping portion 32a, and then bends rearward by approximately 90 degrees to reach the surface of the handle housing 20. The main body casing side engagement portion 32 c expands from the other side of the interposing portion 32 a toward the radially outer side of the interposing portion 32 a , and then bends forward by approximately 90 degrees to reach the surface of the main body casing 10 .

[0052] The upper end portion 25 of the handle housing 20 is elastically deformed by the upper end portion 32 so as to advance and retreat relative to the main housing 10. More specifically, the upper end portion 25 of the handle housing 20 is elastically deformed by the clamping portion 32a so as to approach or separate the handle housing side engaging portion 32b and the main housing side engaging portion 32c so as to advance and retreat relative to the main housing 10. That is, the upper end portion 25 of the handle housing 20 can move mainly forward and backward relative to the main housing 10.

[0053] As mentioned above, Figure 1 The lower end portion 33 of the resin cover 31 shown has Figure 2 , Figure 3 The upper end 32 shown has substantially the same shape and structure. Figure 1 The lower end 26 of the handle housing 20 shown in the figure is elastically deformed similarly to the upper end 32 of the resin cover 31 and moves forward and backward relative to the main body housing 10. That is, the lower end 26 of the handle housing 20 can move mainly forward and backward relative to the main body housing 10 similarly to the upper end 25.

[0054] As mentioned above, Figure 1The handle housing 20 and the main body housing 10 shown are connected in a relatively movable manner via a portion of a continuous resin cover 31 formed on these housings 20 and 10 by double-layer molding. Therefore, the vibration generated in the main body housing 10 is prevented or suppressed from propagating to the handle housing 20 forming the handle 21. That is, in the hammer drill 1A of this embodiment, a portion of the resin cover 31 covering the surface of the handle housing 20 and the main body housing 10 functions as a vibration-proof component. And, a portion of the resin cover 31 that functions as a vibration-proof component is a resin molded body formed on the handle housing 20 and the main body housing 10 by double-layer molding. Therefore, it is possible to achieve a reduction in assembly man-hours and miniaturization by a smaller number of parts than before and a simplified structure, and to obtain a vibration-proof effect equal to or greater than before.

[0055] In addition, the material of the resin cover 31 in this embodiment is elastic, but the material of the resin cover 31 is not particularly limited. However, from the viewpoint of preventing and suppressing vibration transmission, the resin cover 31 is preferably formed of a material softer than the material of the main body housing 10 and the handle housing 20.

[0056] The resin cover 31 as described above is formed, for example, in the following manner. Figure 4 As shown in FIG. 1 , the material resin is supplied into the mold 50 to simultaneously mold the main body housing 10 and the handle housing 20 (one-time molding). Figure 4 In the figure, only the upper end portion 25 of the handle housing 20 and the upper connecting portion 11 of the main housing 10 are shown, but in fact, Figure 1 The handle housing 20 and the main body housing 10 shown are integrally formed by one-step molding.

[0057] Afterwards, if Figure 5 As shown in FIG. 1 , after the molded handle housing 20 and main body housing 10 are placed in another mold 51, a material resin (e.g., an elastic material) is supplied into the mold 51 in which the handle housing 20 and main body housing 10 are placed, and a resin cover 31 is formed on the handle housing 20 and main body housing 10 (secondary molding). That is, by double-layer molding (sometimes also referred to as "two-color molding"), a predetermined area on the surface of the handle housing 20 and main body housing 10 is covered, and a resin cover 31 having an upper end 32 and a lower end 33 ( Figure 1 ) of a resin cover 31. Figure 5 In the figure, only the upper end portion 32 of the resin cover 31 and its vicinity are shown, but in fact, Figure 1 The entire resin cover 31 shown is formed by secondary molding.

[0058] like Figure 1As shown, the limiting component 60a is sandwiched between the upper end 25 of the handle housing 20 and the upper connecting portion 11 of the main body housing 10. Similarly, a limiting component 60b is sandwiched between the lower end 26 of the handle housing 20 and the lower connecting portion 12 of the main body housing 10. The handle housing 20 is movably connected to the main body housing 10 via the elastomer 30. Therefore, when the movement of the handle housing 20 relative to the main body housing 10 is too large, the elastomer 30 may be damaged. The limiting components 60a, 60b limit the movement of the handle housing 20 relative to the main body housing 10 within a predetermined range to prevent damage to the elastomer 30.

[0059] Here, Figure 1 The limiting members 60a, 60b shown have substantially the same shape and structure. Figure 2 , Figure 3 The shape and structure of the restriction member 60 a interposed between the upper end portion 25 and the upper connecting portion 11 will be described in detail, and the shape and structure of the restriction member 60 b interposed between the lower end portion 26 and the lower connecting portion 12 will also be clarified.

[0060] like Figure 2 , Figure 3 As shown, the limiting member 60a is composed of two metal plates 61 and 62 bent approximately 90 degrees at both ends in the longitudinal direction. Figure 2 As shown, the two metal plates 61 and 62 are arranged to cross the upper end 25 and the upper connecting portion 11 in a back-to-back overlapping state. Moreover, the bent portion 63 provided at one end side of the metal plates 61 and 62 in the length direction passes through the slit 20b formed in the end face 20a of the handle housing 20 and is inserted into the inner side of the handle housing 20, and is locked around the slit 20b. In addition, the bent portion 64 provided at the other end side of the length direction of the metal plates 61 and 62 passes through the slit 10b formed in the end face 10a of the main body housing 10 and is inserted into the inner side of the main body housing 10, and is locked around the slit 10b. That is, the bent portion 63 provided at one end side of the length direction of the metal plates 61 and 62 functions as a disengagement prevention portion relative to the upper end 25 of the handle housing 20, and the bent portion 64 provided at the other end side of the length direction of the metal plates 61 and 62 functions as a disengagement prevention portion relative to the upper connecting portion 11 of the main body housing 10. As a result, the movement amount of the upper end portion 25 of the handle housing 20 relative to the main body housing 10 is limited within the range of the full length of the metal plates 61, 62. More strictly speaking, the movement amount of the upper end portion 25 of the handle housing 20 is limited within the range of the interval D between the bent portion 63 at one end side of the metal plates 61, 62 in the longitudinal direction and the bent portion 64 at the other end side in the longitudinal direction.

[0061] As mentioned above, Figure 1 The limiting member 60b shown has Figure 2 , Figure 3 The limiting member 60a shown is substantially the same shape and structure. Figure 1 The amount of movement of the lower end portion 26 of the handle housing 20 shown is also limited within the range of the entire length of the two metal plates constituting the limiting member 60 b.

[0062] therefore, Figure 1 The amount of movement of the handle housing 20 relative to the main housing 10 is limited within a predetermined range (= Figure 2 In addition, the limiting members 60a and 60b formed of metal plates are in surface contact with the handle housing 20 and the main housing 10, so that the unnecessary movement of the handle housing 20 can be limited. For example, the excessive movement of the handle housing 20 in the vertical direction and the left-right direction relative to the main housing 10 can be limited.

[0063] (Second Embodiment)

[0064] Next, another example of an embodiment of the electric working machine of the present invention will be described in detail with reference to the accompanying drawings. However, the electric working machine of this embodiment has the same structure as the hammer drill 1A ( Figure 1 Therefore, the following mainly describes the differences from the hammer drill 1A of the first embodiment, and the description of the same or substantially the same configuration is omitted as appropriate.

[0065] like Figure 6 As shown, the hammer drill 1B of the present embodiment includes a main body housing 10 as a first member and a handle housing 20 as a second member, and the main body housing 10 and the handle housing 20 are connected via an elastic body 30 so as to be relatively movable.

[0066] Figure 6 The connection structure between the main body housing 10 and the handle housing 20 is shown in FIG. Figure 1 The connection structure of the main body housing 10 and the handle housing 20 shown is the same. That is, Figure 6 The main body housing 10 and the handle housing 20 shown are connected to each other in a relatively movable manner via a part (upper end 32 and lower end 33) of a continuous resin cover 31 formed on these housings 10 and 20 by double molding.

[0067] contrast Figure 1 and Figure 6 The restriction members 60a and 60b included in the hammer drill 1B of the present embodiment are different from the restriction members 60a and 60b included in the hammer drill 1A of the first embodiment. Therefore, the restriction members 60a and 60b included in the hammer drill 1B of the present embodiment will be described in detail.

[0068] but, Figure 6 The limiting members 60a, 60b shown have substantially the same shape and structure. Figure 7 , Figure 8 The shape and structure of the restricting member 60a will be described in detail, and the shape and structure of the restricting member 60b will also be clarified.

[0069] like Figure 7 , Figure 8 As shown, the restricting member 60a is composed of a plurality of metal plates 67 having large diameter portions 65 and 66 at both ends in the longitudinal direction. The metal plates 67 have the same shape and size and are arranged to overlap each other across the upper end portion 25 and the upper connecting portion 11.

[0070] like Figure 7 As shown, long holes 68 are formed in the large diameter parts 65 and 66 of each metal plate 67. The plurality of metal plates 67 are stacked so that the long holes 68 formed in each large diameter part 65 communicate with each other and the long holes 68 formed in each large diameter part 66 communicate with each other.

[0071] like Figure 8 As shown, a long hole 68 ( Figure 7 ) of the connecting pin 28, both ends of which are engaged with the handle housing 20. On the other hand, a long hole 68 ( Figure 7 ) of the connecting pin 14, both ends of which are engaged with the main body housing 10. As a result, the movement of the upper end 25 of the handle housing 20 relative to the main body housing 10 is limited to Figure 7 That is, the movement amount of the upper end portion 25 of the handle housing 20 relative to the main body housing 10 is limited within the range of the distance D between the two long holes 68 provided at both ends of the metal plate 67 in the longitudinal direction.

[0072] As mentioned above, Figure 6 The limiting member 60b shown has Figure 7 , Figure 8 The limiting member 60a shown has substantially the same shape and structure. Figure 6 The movement amount of the lower end portion 26 of the handle housing 20 shown is also limited within the range of the distance between the two long holes provided at both ends in the longitudinal direction of the metal plate constituting the limiting member 60b.

[0073] That is, the handle housing 20 is Figure 6 The movement amount of the main body housing 10 shown is limited within a predetermined range (= Figure 7 within the interval D shown).

[0074] Fig. 9 , Fig.10 1 and 2 show different examples of electric working machines in which the main body housing 10 and the handle housing 20 are connected by a connection structure substantially the same as that of the hammer drill 1B of the present embodiment. Fig. 9 The power work machine shown is a saber saw (sometimes also called a "reciprocating saw"). Fig.10 The electric working machine shown is a circular saw.

[0075] Fig. 9 The saw blade 1C shown in the figure includes a motor 40 as a driving source, and a tip tool (saw blade 3 ) is mounted thereon and is reciprocally driven by a driving force output from the motor 40 . Fig.10 The circular saw 1D shown is provided with a motor (not shown) as a driving source, and a tip tool (saw blade 3) is mounted thereon to be rotationally driven by a driving force output from the motor.

[0076] Fig. 9 The saw blade 1C shown and Fig.10 The circular saw 1D shown has a main body housing 10 and a handle housing 20 forming a housing 2. The main body housing 10 and the handle housing 20 are connected to each other via an elastic body 30 so as to be relatively movable. Although the detailed description of the connection structure between the main body housing 10 and the handle housing 20 is omitted, the elastic body 30 is a part of a resin cover 31 formed on the main body housing 10 and the handle housing 20 by double-layer molding and covering the surfaces of these housings 10 and 20.

[0077] Furthermore, at the connection portion between the main body housing 10 and the handle housing 20 , restricting members 60 a and 60 b are provided for restricting the amount of movement of the handle housing 20 relative to the main body housing 10 within a predetermined range.

[0078] (Third Embodiment)

[0079] Hereinafter, another example of an embodiment of the electric working machine of the present invention will be described in detail with reference to the accompanying drawings. However, the electric working machine of this embodiment has the same structure as the hammer drill 1A ( Figure 1 Therefore, the following mainly describes the differences from the hammer drill 1A of the first embodiment, and the description of the same or substantially the same configuration is omitted as appropriate.

[0080] Fig.111 is a partial cross-sectional view of the hammer drill 1E of the present embodiment. The hammer drill 1E of the present embodiment is similar to the hammer drill 1A of the first embodiment in that the main body housing 10 and the handle housing 20 forming the housing 2 are connected via an elastic body 30. Furthermore, the hammer drill 1E of the present embodiment is similar to the hammer drill 1A of the first embodiment in that the elastic body 30 connecting the main body housing 10 and the handle housing 20 is a part (upper end 32, lower end 33) of a resin cover 31 formed on the housings 10 and 20 by double-layer molding and covering the surfaces of these housings 10 and 20.

[0081] On the other hand, the hammer drill 1E of the present embodiment is different from the hammer drill 1A of the first embodiment in that the body housing 10 and the handle housing 20 are connected via the connection portion 70. That is, the body housing 10 and the handle housing 20 in the hammer drill 1E of the present embodiment are connected via both the elastic body 30 and the connection portion 70.

[0082] Fig.12 (a) is in Fig.11 1 is an enlarged view of the C portion surrounded by a dotted line circle. That is, it is an enlarged view of the connection portion between the upper end portion 25 of the handle housing 20 and the upper connecting portion 11 of the main housing 10. Fig.12 As shown in (a), the connecting portion 70 clamped between the upper end 25 of the handle shell 20 and the upper connecting portion 11 of the main body shell 10 includes: a first end 71 connected to the main body shell 10, a second end 72 connected to the handle shell 20, and an intermediate portion 73 connecting these first end 71 and the second end 72.

[0083] The first end portion 71, the second end portion 72, and the middle portion 73 are integrally formed, but the wall thickness of the middle portion 73 is thinner than the wall thickness of the first end portion 71 and the second end portion 72. In other words, the first end portion 71 extending from the main body shell 10 toward the handle shell 20 and the second end portion 72 extending from the handle shell 20 toward the main body shell 10 are connected via the middle portion 73 which is thinner than them.

[0084] The middle portion 73, which is thinner than the first end portion 71 and the second end portion 72, is a weak portion having lower strength than either the first end portion 71 or the second end portion 72. That is, the upper end portion 25 of the handle housing 20 is connected to the upper connecting portion 11 of the main housing 10 via the elastic body 30 and the connecting portion 70 including the weak portion. Fig.11 The connection portion 70 between the lower end portion 26 of the handle housing 20 and the lower connecting portion 12 of the main housing 10 is provided with Fig.12 That is, like the upper end 25, the lower end 26 of the handle housing 20 is connected to the lower connecting portion 12 of the main housing 10 via the elastic body 30 and the connecting portion 70 including the fragile portion.

[0085] like Fig.11 As shown in FIG. 1 , when a force F1 greater than a predetermined value is applied to the handle housing 20 in a direction that causes the handle housing 20 to approach the main housing 10 or a force F2 greater than a predetermined value is applied to the handle housing 20 in a direction that causes the handle housing 20 to move away from the main housing 10, the connection portion 70 is broken. Specifically, when a force F1 is applied to the handle housing 20, as shown in FIG. Fig.12 As shown in (b), the middle portion 73, which is a fragile portion in the connecting portion 70, is broken. On the other hand, when a force F2 is applied to the handle housing 20, as shown in FIG. Fig.12 As shown in (c), the middle portion 73, which is a fragile portion in the connecting portion 70, is broken.

[0086] Here, if Fig.11 As shown in FIG. 1 , a part of the continuous resin cover 31 covering the surface of the main body housing 10 and the handle housing 20, that is, the elastic body 30, covers the surface of the main body housing 10 and the handle housing 20 across the connecting portion 70. Therefore, a force F1 is applied to the handle housing 20 and the intermediate portion 73 is as shown in FIG. Fig.12 When the elastic body 30 is broken as shown in (b), the elastic body 30 is temporarily collapsed. On the other hand, the force F2 is applied to the handle housing 20 and the intermediate portion 73 is as shown in (b). Fig.12 When broken as shown in (c), the elastic body 30 is temporarily stretched.

[0087] like Fig.11 The intermediate portion 73 ( Fig.12 ) is broken as described above, then thereafter, the main body shell 10 and the handle shell 20 are connected only via the elastic body 30. In other words, the main body shell 10 and the handle shell 20 are connected in a manner that allows relative movement. As a result, the handle shell 20 can mainly move forward and backward relative to the main body shell 10, preventing or suppressing the vibration generated in the main body shell 10 from propagating to the handle shell 20 forming the handle 21.

[0088] The breaking of the intermediate portion 73 may be performed in the factory before the hammer drill 1E is shipped, or may be performed by a user who has purchased the hammer drill 1E after purchase.

[0089] The present invention is not limited to the above-mentioned embodiment, and various changes can be made without departing from the scope of the present invention. For example, the first component and the second component connected in a relatively movable manner via an elastic body are not limited to the main body housing 10 and the handle housing 20 described above. Fig.13 , Fig.14 In the illustrated embodiment, a first member 91 and a second member 92 that form at least a portion of a housing of the electric working machine are connected via an elastic body 30 and a connecting portion 70 so as to be relatively movable. Fig.13 , Fig.14The elastic body 30 shown is the same as the elastic body 30 in each embodiment described above, and is a part of a resin cover 31 formed on the first member 91 and the second member 92 by double-layer molding and covering the surfaces of the first member 91 and the second member 92. Fig.13 , Fig.14 Each of the connecting portions 70 shown has Fig.11 , Fig.12 The connecting portions 70 shown are of substantially the same structure.

[0090] On the other hand, Fig.13 , Fig.14 In the embodiment shown, the handle 21 is formed by both the first component 91 and the second component 92. Fig.13 As shown, the front portion 21 a of the handle 21 is formed by the first component 91 , and the rear portion 21 b of the handle 21 is formed by the second component 92 .

[0091] When Fig.13 When a force F1 greater than or equal to a predetermined value is applied to the second member 92 in a direction that causes the second member 92 to approach the first member 91 or a force F2 greater than or equal to a predetermined value is applied to the second member 92 in a direction that causes the second member 92 to separate from the first member 91, the intermediate portion 73 (refer to the “intermediate portion 73” in FIG. Fig.12 ) is broken. That is, Fig.13 , Fig.14 A number of connections 70 are shown broken.

[0092] If the connecting portion 70 is broken, the first component 91 and the second component 92 are connected only via the elastic body 30. In other words, the first component 91 and the second component 92 are connected in a relatively movable manner. In further other words, the rear portion 21b of the handle 21 can mainly move forward and backward relative to the first component 91 including the front portion 21a of the handle 21. As a result, the vibration generated in the first component 91 is prevented or suppressed from propagating to the rear portion 21b of the handle 21. In addition, the rear portion 21b of the handle 21 is the portion that mainly contacts the palm of the operator holding the handle 21.

[0093] like Fig.15 As shown, only the upper portion of the second component 92 may be connected to the first component 91 via one or more connecting portions 70. In this case, Fig.15 The second member 92 shown is relatively movable (can swing) with respect to the first member 91 with its lower portion serving as a fulcrum after the connection portion 70 is broken.

[0094] The shape of the connection part in the present invention is not limited to the shapes shown in the figures referred to above. The connection part in the present invention only needs to include a first end connected to the first component, a second end connected to the second component, and an intermediate part connecting the first end and the second end which is weaker than the first end and the second end, and its shape is not particularly limited. Therefore, Fig.16 (a) to (d) show several modified examples of the connection portion.

[0095] Fig.16 The connection portion 70 shown in (a) to (d) includes a first end portion 71, a second end portion 72, and an intermediate portion 73. In addition, the intermediate portion 73 connecting the first end portion 71 and the second end portion 72 is thinner than the first end portion 71 and the second end portion 72, or at least includes a portion thinner than the first end portion 71 and the second end portion 72, and is weaker than the first end portion 71 and the second end portion 72 as a whole.

[0096] Fig.16 The connection portion 70 shown in (a) includes an intermediate portion 73 that tapers from the second end portion 72 toward the first end portion 71 , and the apex of the intermediate portion 73 is connected to the first end portion 71 . Fig.16 The connection portion 70 shown in (b) includes an intermediate portion 73 including an arc portion bulging from the second end portion 72 toward the first end portion 71 and an arc portion bulging from the first end portion 71 toward the second end portion 72, and the vertices of the two arc portions are connected to each other. Fig.16 The connection portion 70 shown in (c) includes an intermediate portion 73 that tapers from the first end portion 71 toward the second end portion 72 , and the apex of the intermediate portion 73 is connected to the second end portion 72 . Fig.16 The connection portion 70 shown in (d) includes an intermediate portion 73 including a sharp portion tapering from the second end portion 72 toward the first end portion 71 and a sharp portion tapering from the first end portion 71 toward the second end portion 72, and the vertices of the two sharp portions are connected to each other.

[0097] Explanation of symbols

[0098] 1A, 1B, 1E—hammer drill; 1C—knife saw; 1D—circular saw; 2—housing; 3—drill bit (saw blade); 10—main body shell; 10a, 20a—end surface; 10b, 20b—slit; 11—upper side connecting portion; 12—lower side connecting portion; 13—engaging portion; 14—connecting pin; 20—handle shell; 21—handle; 21a—front portion; 21b—rear portion; 22—trigger lever; 23—battery mounting portion; 24—battery pack; 25—upper side end portion; 26—lower side end portion; 27—engaging portion; 28—connecting pin; 30—elastic body; 31—resin cover; 32—upper end part; 32a—clamping part; 32b—handle shell side snap-in part; 32c—main shell side snap-in part; 33—lower end; 40—motor; 41—transmission mechanism; 42—cooling fan; 43—pinion; 44—bevel gear; 45—intermediate shaft; 46—cylinder body; 47—retaining sleeve; 50, 51—mold; 60a, 60b—limiting part; 61, 62, 67—metal plate; 63, 64—bending part; 65, 66—large diameter part; 68—long hole; 70—connecting part; 71—first end; 72—second end; 73—middle part; 91—first part; 92—second part.

Claims

1. An electric working machine having a motor as a driving source and equipped with a front end tool driven by a driving force output from the motor, The above-mentioned electric working machine is characterized in that: having a first portion and a second portion forming at least a portion of the housing, The first part and the second part are separated from each other and can move relative to each other. The elastic body formed on the housing by double-layer molding is arranged across the first portion and the second portion. The first portion is formed by combining the first portion on one side and the first portion on the other side which can be divided in a predetermined direction, The second portion is formed by combining the second portion on one side and the second portion on the other side which can be divided in the predetermined direction. The above-mentioned elastomer includes: An elastic body on one side, which is formed on the first portion on one side and the second portion on one side by double-layer forming; as well as The other-side elastic body is formed on the other-side first portion and the other-side second portion by double-layer molding.

2. The electric working machine according to claim 1, characterized in that: The first portion is a part of a main body housing, and the main body housing accommodates the motor and a transmission mechanism for transmitting the driving force output from the motor to the front end tool. The second portion is a portion of the handle held by the operator.

3. The electric working machine according to claim 2, characterized in that: The handle has a battery mounting portion on which a battery for supplying electric power to the motor is mounted.

4. The electric working machine according to claim 1, characterized in that: The elastic body is formed on both the first portion and the second portion by double-layer molding.

5. The electric working machine according to claim 1, characterized in that: A first engaging portion that engages with the elastic body is provided on a surface of the first portion near an end portion on the second portion side. A second engaging portion that engages with the elastic body is provided on a surface of the second portion in the vicinity of an end portion on the first portion side.

6. The electric working machine according to claim 2, characterized in that: The handle housing forming the handle has an upper end portion and a lower end portion connected to the main body housing.

7. The electric working machine according to claim 1, characterized in that: A limiting portion is provided, which is interposed between the first portion and the second portion and limits the amount of movement of the second portion relative to the first portion within a predetermined range.

8. The electric working machine according to claim 6, characterized in that: The invention also provides wiring passing through the handle housing and the main body housing, wherein the wiring is covered by the elastic body.

9. The electric working machine according to claim 6, characterized in that: The front end tool strikes with the pressure change caused by the reciprocating motion of the piston in the forward and backward directions. The second portion is movable in the front-rear direction relative to the first portion.

10. The electric working machine according to claim 1, characterized in that: The raw material of the above-mentioned elastomer is elastic material.

11. An electric working machine comprising a motor as a driving source and equipped with a front end tool driven by a driving force output from the motor, The above-mentioned electric working machine is characterized in that: The invention comprises a first member and a second member which are one member forming at least a part of the housing, and a connecting portion connecting the first member and the second member, The first component has a first portion. The second component has a second portion that is separate from and relatively movable to the first portion. The elastic body formed on the outer surfaces of the first component and the second component by double-layer molding is arranged across the first part and the second part. The first portion and the second portion are relatively movable with the connection portion as a fulcrum.

12. An electric working machine comprising a motor as a driving source and equipped with a front tool driven by a driving force output from the motor, The above-mentioned electric working machine is characterized in that: having a first portion and a second portion forming at least a portion of the housing, The first part and the second part are connected via a connecting portion and an elastic body. The connecting part includes: a first end connected to the first portion; a second end connected to the second portion; and an intermediate portion connecting the first end and the second end, The first end, the second end and the middle portion are integrally formed, and the middle portion is weaker than the first end and the second end. The elastic body is a part of a continuous resin cover that is formed on the first portion and the second portion by double-layer molding and covers the surfaces of the first portion and the second portion across the connecting portion.

13. The electric working machine according to claim 12, characterized in that: When a force having a predetermined magnitude or greater is applied to the second portion in a direction in which the second portion approaches the first portion or moves away from the first portion, the intermediate portion breaks.

14. The electric working machine according to claim 12, characterized in that: The thickness of the intermediate portion is thinner than the thickness of the first end portion and the second end portion.

15. The electric working machine according to claim 12, characterized in that: The second portion forms part of a handle held by an operator.

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