Electric working machine and cord guard

Abstract

To provide a technique for improving bending resistance of a cord guard and a power supply cord.SOLUTION: The electric working machine includes a housing, a motor, a power cord, and a cord guard. The cord guard has an internal space through which the power cord passes. The cord guard includes a connecting portion, an outlet portion, and an intermediate portion. The connection portion is connected to the outlet. The power cord is exposed to the outside from the outlet portion. The intermediate portion is located between the connection portion and the outlet portion, and includes a plurality of large diameter portions and a plurality of small diameter portions. The plurality of small-diameter portions have a smaller outer diameter than the plurality of large-diameter portions. Each of the plurality of large diameter portions has a first length in an extending direction of the cord guard. Each of the plurality of small diameter portions has a second length in the extending direction, and the second length is shorter than the first length.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a cord guard and a technique for improving the bending resistance of a power cord. [Background technology]

[0002] The cord guard of the tool described in Patent Document 1 has a large diameter portion with a large outer diameter and a small diameter portion with a small outer diameter. The large diameter portion and the small diameter portion have the same width and are arranged alternately in the extension direction of the cord guard. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] German Patent Application Publication No. 102010031307 Summary of the Invention [Problem to be solved by the invention]

[0004] The cord guard of the above-mentioned tool is bent at a nearly right angle, so a very large load is placed on the bent part. As a result, when a user uses the tool on a daily basis, stress accumulates on the cord guard and the power cord inside, which can damage or break the cord guard or power cord more quickly than expected.

[0005] One aspect of the present disclosure provides a technique for improving the bending resistance of cord guards and power cords. [Means for solving the problem]

[0006] An electric work machine according to one aspect of the present disclosure includes a housing, a motor, a power cord, and a cord guard. The housing has a drawer opening formed therein. The motor is built into the housing. The power cord is drawn out from the drawer opening and connected to an external power source to supply power from the external power source to the motor. The cord guard has an internal space through which the power cord passes. The cord guard includes a connection portion, an outlet portion, and an intermediate portion. The connection portion is connected to the drawer opening. The power cord is exposed to the outside from the outlet portion. The intermediate portion is located between the connection portion and the outlet portion and includes a plurality of large diameter portions and a plurality of small diameter portions. The plurality of small diameter portions have an outer diameter smaller than that of the plurality of large diameter portions. Each of the plurality of large diameter portions has a first length in the extension direction of the cord guard. Each of the plurality of small diameter portions has a second length in the extension direction, the second length being shorter than the first length.

[0007] In the above-mentioned electric work machine, the second length of the cord guard is shorter than the first length. This prevents adjacent large diameter portions from coming into contact with each other when the cord guard is bent, preventing the radius of curvature from becoming excessively small, improving the bending resistance of the cord guard. As a result, the load on the power cord is reduced, improving the durability of the power cord.

[0008] A cord guard according to another aspect of the present disclosure is attached to a power cord pulled out from the outlet of the housing. The cord guard has an internal space through which the power cord passes. The cord guard includes a connection portion, an outlet portion, and an intermediate portion. The connection portion is connected to the outlet. The power cord is exposed to the outside from the outlet portion. The intermediate portion is located between the connection portion and the outlet portion. The intermediate portion has a plurality of large diameter portions and a plurality of small diameter portions. The plurality of small diameter portions have an outer diameter smaller than that of the plurality of large diameter portions. Each of the plurality of large diameter portions has a first length in the extension direction of the cord guard. Each of the plurality of small diameter portions has a second length in the extension direction, the second length being shorter than the first length.

[0009] The cord guard has the same effects as the electric working machine. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a diagram showing the appearance of an electric operating machine according to an embodiment of the present invention; [Figure 2] 1 is a cross-sectional view of an electric operating machine according to an embodiment of the present invention. [Figure 3] FIG. 2 is a side view showing the appearance of the cord guard according to the present embodiment. [Figure 4] FIG. 2 is a perspective view showing the appearance of the cord guard according to the present embodiment. [Figure 5] 4 is a cross-sectional view of a connection portion of the cord guard according to the embodiment. FIG. [Figure 6] 5 is a schematic diagram showing the lengths of the large diameter portion and the small diameter portion of the cord guard according to the embodiment. FIG. [Figure 7A] 1 is a side view of the cord guard according to the present embodiment when a first load is applied to the cord guard. FIG. [Figure 7B] 10 is an enlarged view of a middle portion of the cord guard according to the present embodiment when a first load is applied to the cord guard. FIG. [Figure 7C] 10 is a cross-sectional view of the middle part of the cord guard when a first load is applied to the cord guard according to the present embodiment. FIG. [Figure 8A] 10 is a side view of the cord guard according to the present embodiment when a second load that is lighter than the first load is applied to the cord guard. FIG. [Figure 8B] 10 is a cross-sectional view of the cord guard according to the present embodiment when a second load is applied to the cord guard. FIG. [Figure 9] 5A and 5B are diagrams showing bending lines of the cord guard according to the embodiment; [Figure 10] Fig. 10A is a diagram showing a state in which the cord guard according to the first reference example is bent, and Fig. 10B is an enlarged view of the underside of the cord guard according to the first reference example. [Figure 11] Fig. 11A is a diagram showing a bent state of the cord guard according to the second reference example, Fig. 11B is an enlarged view of the lower side of the cord guard according to the second reference example, and Fig. 11C is an enlarged view of the upper side of the cord guard according to the second reference example. [Figure 12] FIG. 10 is a cross-sectional view of a cord guard according to a third reference example. DETAILED DESCRIPTION OF THE INVENTION

[0011] [Summary of the embodiment] An embodiment may provide an electric power tool having at least one of the following features: Feature 1: Housing with a drawer opening. Feature 2: Motor built into the housing. Feature 3: A power cord that is pulled out from the outlet and connected to an external power source to supply power from the external power source to the motor. Feature 4: A cord guard with an internal space through which the power cord can pass. Feature 5: The cord guard has a connection part that is connected to the outlet. Feature 6: The cord guard has an outlet portion through which the power cord is exposed to the outside. Feature 7: The cord guard has an intermediate portion located between the connection portion and the outlet portion. Feature 8: The intermediate portion has a plurality of large diameter portions and a plurality of small diameter portions. Feature 9: The plurality of small diameter portions have an outer diameter smaller than that of the plurality of large diameter portions. Feature 10: Each of the large diameter portions has a first length in the extension direction of the cord guard. Feature 11: Each of the plurality of small diameter portions has a second length in the extension direction. · Feature 12: The second length is shorter than the first length.

[0012] In an electric work machine having at least Features 1 to 12, the second length of the cord guard is shorter than the first length. This prevents adjacent large diameter portions from coming into contact with each other when the cord guard is bent, preventing the radius of curvature from becoming excessively small, improving the bending resistance of the cord guard. This in turn prevents damage to the cord guard. Furthermore, this prevents the cord guard from being torn, exposing the power cord, or causing the power cord to break, improving the durability of the power cord.

[0013] Some embodiments may include the following features in addition to or instead of at least one of Features 1 to 13 above. Feature 14: The outlet portion has a first inner diameter, and the first inner diameter increases with increasing distance from the intermediate portion.

[0014] In an electric work machine having at least Features 1 to 14, the inner diameter of the outlet increases with increasing distance from the intermediate section, allowing the power cord to bend flexibly along the inner surface of the outlet. This prevents the power cord from being locally loaded at the outlet, which can cause the power cord to break. Furthermore, the power cord's ability to follow the movement of the electric work machine is improved when working with the electric work machine, allowing the user to use the electric work machine comfortably.

[0015] Some embodiments may include at least one of the following features in addition to or instead of at least one of Features 1 to 14 above. Feature 15: The housing has a protrusion that protrudes from the inner surface of the outlet toward the inside of the outlet. Feature 16: The connecting portion is recessed radially inward of the cord guard and has a recess that engages with the protrusion.

[0016] In an electric work machine having at least Features 1 to 13 and 15 to 16, the cord guard is supported by the protrusion of the housing, which distributes the load of the electric work machine between the cord guard and the housing, improving the bending resistance of the cord guard. This can be particularly effective when the load on the power cord and cord guard is relatively heavy.

[0017] Some embodiments may include the following features in addition to or instead of at least one of Features 1 to 16 above. Feature 17: The large diameter portions and the small diameter portions are arranged near the center of the intermediate portion of the cord guard.

[0018] In an electric operating machine having at least Features 1 to 13 and 17, the large diameter portions and the small diameter portions are arranged close to the center of the middle section, which makes it possible to maintain the strength of the connection portion and the outlet portion of the middle section on which the load of the electric operating machine is applied, thereby maintaining the durability of the cord guard.

[0019] Some embodiments may include at least one of the following features in addition to or instead of at least one of Features 1 to 17 above. Feature 18: The power cord has a first outer diameter. Feature 19: The intermediate portion has a second inner diameter that is larger than the first outer diameter.

[0020] In an electric work machine having at least Features 1 to 13 and 18 to 19, the inner diameter of the middle section is larger than the outer diameter of the power cord, so the cord guard can be detached from the power cord. This means that the cord guard can be replaced when it wears out.

[0021] Some embodiments may include the following features in addition to or instead of at least one of Features 1 to 19 above. Feature 20: The first length is three times the second length.

[0022] In an electric operating machine having at least Features 1 to 13 and 20, the first length is three times the second length, which optimizes the radius of curvature when the cord guard is bent, thereby further improving the bending resistance of the cord guard.

[0023] Some embodiments may include the following features in addition to or instead of at least one of Features 1 to 20 above. Feature 21: The second length is 1 mm or more.

[0024] In an electric working machine having at least Features 1 to 13 and 21, the second length of 1 mm or more can prevent the small diameter portion from being torn apart by the load of the electric working machine, thereby allowing the cord guard to bend flexibly while maintaining its durability.

[0025] Examples of the above-mentioned electric work machines include various types of equipment configured to be used at work sites such as construction, manufacturing, gardening, and civil engineering, specifically, power tools for masonry, metalwork, and woodworking, power tools for gardening, power tools for improving the environment at work sites, fan vests, fan jackets, push carts, electrically assisted bicycles, and air pumps.

[0026] Examples of the power tools mentioned above include electric chainsaws, electric hand saws, electric blowers, electric hammers, electric hammer drills, electric drills, electric screwdrivers, electric wrenches, electric impact drivers, electric impact wrenches, electric grinders, electric circular saws, electric reciprocating saws, electric jigsaws, electric cutters, electric planers, electric nail guns (including tackers), electric hedge trimmers, electric lawn mowers, electric lawn clippers, electric brush cutters, electric cleaners, electric sprayers, electric spreaders, electric dust collectors, electric trowels, electric vibrators, electric rammers, electric compactors, electric pumps, electric pile drivers, electric concrete saws, electric screeds, and electric cut-off saws.

[0027] In one embodiment, a cord guard having at least one of the above features 4 to 21 may be provided.

[0028] In one embodiment, the above features 1 to 21 may be combined in any manner. In some embodiments, any of the above features 1 to 21 may be omitted.

[0029] Specific Exemplary Embodiments Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[0030] <1. Overall structure> An electric working machine 1 according to this embodiment will be described with reference to Figure 1. The electric working machine 1 is an electric drill. A hammer drill is a type of electric tool.

[0031] The electric working machine 1 includes a housing 20. The housing 20 forms the outer shell of the electric working machine 1. The housing 20 includes a main body 21 and a hand grip 22. The main body 21 has a rectangular parallelepiped shape. The main body 21 has a first end and a second end. The first end is one of the two longitudinal ends of the main body 21. The second end is the other of the two longitudinal ends of the main body 21. The hand grip 22 is connected to the first end of the main body 21 and extends from the first end. Hereinafter, the longitudinal direction of the main body 21 will be referred to as the front-rear direction, the extension direction of the hand grip 22 as the up-down direction, and the direction perpendicular to the front-rear direction and up-down direction as the left-right direction.

[0032] As shown in Fig. 2, the electric work machine 1 includes a motor 80 built into the main body 21. The motor 80 is, for example, a three-phase brushless motor or a three-phase brushed motor. The motor 80 receives electric power and rotates.

[0033] The electric work machine 1 includes a tool holder 6. The tool holder 6 is installed at a second end of the main body 21. The tool holder 6 holds a tool tip such as a drill bit. The tool tip receives a driving force generated by the rotation of the motor 80 and moves linearly and / or rotary.

[0034] The electric working machine 1 is equipped with a side handle 40. The side handle 40 is fixed to the rear side of the second end of the main body 21 and extends in the vertical direction. A user uses the electric working machine 1 by holding the hand grip 22 and the side handle 40.

[0035] The electric work machine 1 includes a trigger 30. The trigger 30 is located on the front of the hand grip 22. A user operates the trigger 30 to drive or stop the motor 80. More specifically, when the user pulls the trigger 30, the motor 80 drives. When the user releases the trigger 30, the motor 80 stops.

[0036] The electric work machine 1 includes a power cord 60. The power cord 60 is electrically connected to the motor 80 and is drawn out from a draw-out port 35 formed in the housing 20. As shown in FIG. 2, the draw-out port 35 is formed on the underside of the handgrip 22 and is a generally cylindrical recess. The draw-out port 35 has a circular shape in a plane perpendicular to the up-down direction. The power cord 60 is connected to an external power source and supplies power from the external power source to the motor 80. The external power source is, for example, a single-phase AC commercial power source.

[0037] 3 and 4, the horizontal cross section of the power cord 60 has a circular shape with an outer diameter (diameter) R1. The horizontal cross section is perpendicular to the extension direction of the power cord 60. The horizontal cross section of the power cord 60 is not limited to a circular shape, and may have any shape without corners, such as an elliptical shape. In this embodiment, the outer diameter R1 corresponds to an example of a first outer diameter in summary of the embodiment.

[0038] The housing 20 includes a rib 33. As shown in FIGS. 2 and 5, the rib 33 is disposed on the inside of the housing 20. More specifically, the rib 33 protrudes inward from the inner surface of the outlet 35. That is, the rib 33 protrudes from the inner surface of the outlet 35 toward the opposing inner surface. The rib 33 is disposed around the entire circumferential direction of the inner surface of the outlet 35. Note that in another embodiment, the rib 33 does not need to be disposed around the entire circumferential direction of the inner surface of the outlet 35. For example, the rib 33 may include a plurality of protrusions, which are disposed at predetermined intervals on the inner surface of the outlet 35. In this embodiment, the rib 33 corresponds to an example of a general protrusion of the embodiment.

[0039] The electric work machine 1 is equipped with a cord guard 50. The cord guard 50 has a generally cylindrical shape with an internal space. The cord guard 50 is connected (attached) to the outlet 35 of the housing 20. The power cord 60 passes through the internal space of the cord guard 50. The weight of the electric work machine 1 acts on the power cord 60 near the outlet 35, making the power cord 60 prone to breakage or damage. The cord guard 50 protects the parts of the power cord 60 that are prone to breakage or damage.

[0040] <2. Code Guard Configuration> Next, the configuration of the cord guard 50 according to this embodiment will be described. The cord guard 50 is made of an insulating material. For example, the cord guard 50 may be made of a rubber material such as ethylene propylene diene rubber or urethane rubber, or polyvinyl chloride.

[0041] As shown in FIG. 8B , the cord guard 50 is a generally cylindrical member, and defines an internal space 58. The power cord 60 passes through the internal space 58. The internal space 58 is generally cylindrical. The cord guard 50 has an inner diameter R2, which corresponds to the diameter of the internal space 58. The inner diameter R2 is the diameter of the narrowest point of the internal space 58 and corresponds to the smallest inner diameter of the power cord 60. The inner diameter R2 is larger than the outer diameter R1. Therefore, the cord guard 50 does not adhere to the power cord 60, and a gap exists between the inner surface of the cord guard 50 and the outer surface of the power cord 60. Therefore, the cord guard 50 can be removed from the power cord 60. In this embodiment, the inner diameter R2 corresponds to an example of a second inner diameter.

[0042] The cord guard 50 has a length L1 in the extension direction. The length L1 is at least five times the inner diameter R2. As shown in FIG. 3 , the cord guard 50 includes a connection portion 55, an intermediate portion 57, and an outlet portion 54. The connection portion 55 is the portion closer to the housing 20, and the outlet portion 54 is the portion farther from the housing 20. The intermediate portion 57 is located between the connection portion 55 and the outlet portion 54, and is connected to the connection portion 55 and the outlet portion 54.

[0043] The connecting portion 55 is connected to the outlet 35 of the housing 20. The connecting portion 55 is inserted into the outlet 35 and disposed inside the housing 20. More specifically, the connecting portion 55 has a groove 56. The groove 56 is recessed radially inward from the outer surface of the connecting portion 55. The radial direction corresponds to the radial direction of the cord guard 50. The groove 56 is formed around the entire circumferential direction of the outer surface of the connecting portion 55. As shown in FIGS. 2 and 5 , the groove 56 engages with the rib 33 of the housing 20. The cord guard 50 is fixed to the housing 20 by inserting the connecting portion 55 into the outlet 35 and engaging the groove 56 with the rib 33. In this embodiment, the groove 56 corresponds to an example of a recess in the overall embodiment.

[0044] The outer diameter of the intermediate portion 57 generally decreases as one approaches the outlet portion 54 from the connection portion 55. Specifically, the outer diameter of the intermediate portion 57 decreases as one approaches the outlet portion 54 from the connection portion 55, except for a small diameter portion 511, which will be described later. As shown in FIGS. 7C and 8B , the inner diameter of the intermediate portion 57 is constant. Therefore, the thickness of the material of the intermediate portion 57 generally decreases as one approaches the outlet portion 54 from the connection portion 55. Specifically, the thickness of the material of the intermediate portion 57 decreases as one approaches the outlet portion 54 from the connection portion 55, except for the small diameter portion 511.

[0045] Intermediate portion 57 includes bellows portion 51, first flat portion 53, and second flat portion 52. First flat portion 53 is connected to connecting portion 55. Second flat portion 52 is connected to outlet portion 54. Bellows portion 51 is the center of intermediate portion 57 and is located between first flat portion 53 and second flat portion 52.

[0046] Bellows portion 51 has a plurality of large diameter portions 512 and a plurality of small diameter portions 511. The outer diameter of small diameter portions 511 is smaller than the outer diameter of large diameter portions 512. As shown in Fig. 3, small diameter portions 511 and large diameter portions 512 are arranged alternately.

[0047] Each of the small diameter portions 511 corresponds to a groove recessed radially inward from the outer surface of the cord guard 50. Each of the small diameter portions 511 is formed around the entire circumferential direction of the outer surface of the cord guard 50. The spaces between the grooves formed on the outer surface of the cord guard 50 correspond to large diameter portions 512. No grooves corresponding to the small diameter portions 511 are formed in the first flat portion 53 and the second flat portion 52. That is, the plurality of large diameter portions 512 and the plurality of small diameter portions 511 are arranged toward the center of the intermediate portion 57. In this embodiment, the bellows portion 51 has four small diameter portions 511 and three large diameter portions 512.

[0048] The bellows portion 51 is disposed near the center of the cord guard 50, allowing the cord guard 50 to bend flexibly. As shown in FIG. 6, each of the large diameter portions 512 has a first length (width) W1 in the extension direction of the cord guard 50. Each of the small diameter portions 511 has a second length (width) W2 in the extension direction of the cord guard 50. The second length W2 is shorter than the first length W1. Preferably, the first length W1 is three times the second length W2. This length ratio optimizes the radius of curvature when the cord guard 50 is bent.

[0049] Preferably, the second length W2 is 1 mm or more. If the second length W2 is too short, cracks may occur in the cord guard 50 when the cord guard 50 is bent. By setting the second length W2 to 1 mm or more, tearing of the small diameter portion 511 when the cord guard 50 is bent is suppressed.

[0050] As shown in FIG. 6 , the outer diameters of the multiple large diameter portions 512 decrease from the first flat portion 53 toward the second flat portion 52. The multiple small diameter portions 511 all have the same outer diameter. The multiple small diameter portions 511 have a thickness sufficient to maintain the insulation of the small diameter portions 511. Therefore, the difference in outer surface area between adjacent large diameter portions 512 and small diameter portions 511 decreases from the first flat portion 53 toward the second flat portion 52. In other words, the depth of the groove corresponding to the small diameter portion 511 decreases from the first flat portion 53 toward the second flat portion 52. The small diameter portion 511 adjacent to the first flat portion 53 corresponds to a groove with a depth d1. The small diameter portion 511 adjacent to the second flat portion 52 corresponds to a groove with a depth d2, and the depth d2 is shorter than the depth d1.

[0051] The outlet portion 54 is connected to the second flat portion 52. The power cord 60 is exposed to the outside from the outlet portion 54. As shown in Figures 3 and 8, the inner and outer surfaces of the outlet portion 54 have a trumpet shape that widens as it moves away from the second flat portion 52. That is, the inner and outer diameters of the outlet portion 54 increase with increasing distance from the intermediate portion 57.

[0052] The outlet portion 54 has a first end and a second end. The first end is connected to the second flat portion 52 and has an inner diameter R3. The second end faces the first end, and the power cord 60 is exposed to the outside from the second end. The second end has an inner diameter R4 larger than the inner diameter R3 and an outer diameter R5. The end of the connection portion 55 has an outer diameter R6, which is twice or approximately twice the outer diameter R5. The power cord 60 passes from inside the housing 20 through the cord guard 50 and is guided to the flared inner surface of the outlet portion 54, where it is exposed to the outside.

[0053] <2-1. Bending under heavy load> 7A, 7B, and 7C, the bending of the cord guard 50 when a first load is applied to the cord guard 50 will be described. FIG. 7A shows the bending of the cord guard 50 when the electric work tool 1 is fixed and a first weight is hung from the power cord 60. The first weight has a first load. The first load is relatively large and is approximately the same weight as the electric work tool 1, for example, 4 kg.

[0054] When a first load is applied to the cord guard 50, the load is applied to the side of the cord guard 50 closest to the electric tool 1. In the cord guard 150 according to the first reference example shown in FIGS. 10A and 10B, the length of the small-diameter portion is equal to the length of the large-diameter portion. In this case, the load applied to the cord guard 150 is not distributed across the multiple large-diameter portions but is concentrated locally. Therefore, as shown by the bending line in FIG. 9, the cord guard 150 bends at a steep angle near the electric tool, resulting in an excessively small radius of curvature. As a result, if a user uses the electric tool on a daily basis, the power cord may break sooner than expected. The horizontal axis in FIG. 9 indicates the horizontal distance from the end of the connection portion 55. The vertical axis in FIG. 9 indicates the vertical distance from the end of the connection portion 55. The horizontal direction is the extension direction of the cord guard 50. The vertical direction is the direction perpendicular to the extension direction.

[0055] 11A to 11C, the length of the small diameter portion of the cord guard 250 according to the second reference example is equal to the length of the large diameter portion, and the lengths of the large diameter portion and the small diameter portion are shorter than the lengths of the large diameter portion and the small diameter portion of the cord guard 150 according to the first reference example. Specifically, the lengths of the large diameter portion and the small diameter portion of the cord guard 250 are less than 1 mm. In this case, the load applied to the cord guard 50 is dispersed among the multiple large diameter portions. However, when a load is applied to the cord guard 250, the small diameter portion may tear. In other words, if the small diameter portion is excessively short, the load applied to the cord guard 250 may exceed the tensile strength of the cord guard 250, causing cracks in the cord guard 250.

[0056] The inventors have studied the shape of the cord guard 50 to solve the problems that arise when a relatively heavy load such as that described above is applied to the cord guard 50. As a result of their studies, the inventors have found that by making the second length W2 of the small diameter portion 511 shorter than the first length W1 of the large diameter portion 512, the radius of curvature of the cord guard 50 when it bends can be prevented from becoming excessively small. More specifically, as shown in Figures 7B and 7C, by making the second length W2 shorter than the first length W1, the load applied to the cord guard 50 is distributed among the multiple large diameter portions 512, and adjacent large diameter portions 512 are prevented from coming into contact with each other, preventing the cord guard 50 from bending sharply.

[0057] In particular, as a result of the inventor's investigations, it was found that by making the first length W1 three times the second length W2, the radius of curvature when the cord guard 50 is bent becomes optimal. As a result, it was found that the cord guard 50 can be ideally bent, as shown by the bending line in Fig. 9. More specifically, the position of the cord guard 50 at a distance X1 in the horizontal direction is located at a distance Y1 in the vertical direction, and the distance X1 is approximately equal to the distance Y1.

[0058] Furthermore, as a result of studies by the inventors, it has been found that by setting the second length W2 to 1 mm or more, it is possible to suppress the occurrence of cracks in the small diameter portion 511 even when a relatively heavy load is applied to the cord guard 50. It has also been found that by supporting the connection portion 55 with the rib 33, the load is distributed to the cord guard 50 and the housing 20, improving the bending resistance of the cord guard 50.

[0059] <2-2. Flexibility under light load> 8A and 8B, the bending of the cord guard 50 when a second load is applied to the cord guard 50 will be described. FIG. 8A shows the bending of the cord guard 50 when the electric operating tool 1 is fixed and a second weight is hung from the power cord 60. The second weight has a second load. The second load is relatively small and is smaller than the first load. The second load is, for example, 1 kg.

[0060] When the second load is applied to the cord guard 50, the load is applied to the side of the cord guard 50 farther from the electric work machine 1, that is, to the outlet portion . The cord guard 350 according to the third reference example shown in FIG. 12 has a length L2 in the extension direction. Length L2 is longer than length L1. The cord guard 350 has a long overall length, allowing the entire cord guard 350 to bend flexibly, thereby preventing the power cord from bending sharply at the outlet. Consequently, the long overall length of the cord guard 350 prevents the power cord from breaking at the outlet. However, when the load acting on the cord guard 305 is very light, the entire cord guard 350 does not bend flexibly, as shown by the bending lines in FIG. 9. As a result, the power cord bends sharply at the outlet, making it more susceptible to breakage.

[0061] Furthermore, if the length L2 is long, the storage space required for the electric working machine 1 increases. Consequently, the storage case for the electric working machine 1 also becomes larger. Furthermore, in order to make the cord guard 350 compatible with a relatively heavy electric working machine 1, the connecting portion of the cord guard 350 needs to be thickened. In this case, the cord guard 350 becomes even larger, and the storage space required for the electric working machine 1 also becomes even larger.

[0062] The inventors studied the shape of the cord guard 50 to solve the problems that arise when a relatively light load such as the one described above is applied to the cord guard 50. As a result of their studies, the inventors found that forming the inner surface of the outlet 54 into a trumpet shape corrects the angle of the power cord 60 at the outlet 54 and prevents the power cord 60 from bending at a sharp angle. In other words, they found that by forming the inner surface of the outlet 54 into a shape with an ideal radius of curvature, the power cord 60 bends at an ideal angle along the inner surface of the outlet 54.

[0063] <3. Effects> According to the present embodiment described above in detail, the following effects are achieved. (1) The second length W2 is shorter than the first length W1. This prevents the adjacent large diameter portions 512 from coming into contact with each other when the cord guard 50 is bent, preventing the radius of curvature from becoming excessively small, improving the bending resistance of the cord guard 50. This in turn prevents damage to the cord guard 50. Furthermore, exposure or breakage of the power cord 60 due to damage to the cord guard 50 is prevented, improving the durability of the power cord 60.

[0064] (2) Because the inner diameter of the outlet portion 54 increases with increasing distance from the intermediate portion 57, the power cord 60 bends flexibly along the inner surface of the outlet portion 54. This prevents a load from concentrating locally on the power cord 60 at the outlet portion 54, which can prevent the power cord 60 from breaking. Furthermore, when working with the electric work machine 1, the power cord 60 is able to better follow the movement of the electric work machine 1, allowing the user to use the electric work machine 1 comfortably.

[0065] (3) By supporting the cord guard 50 with the ribs 33 of the housing 20, the load acting on the cord guard 50 is distributed between the cord guard 50 and the housing 20. This improves the bending resistance of the cord guard 50. In particular, when the load acting on the cord guard 50 is relatively heavy, the bending resistance of the cord guard 50 can be improved.

[0066] (4) The multiple large diameter portions 512 and the multiple small diameter portions 511 are arranged close to the center of the intermediate portion 57. This allows the strength of the first flat portion 53 and the second flat portion 52, which are subjected to a load, to be maintained. This in turn allows the durability of the cord guard 50 to be maintained.

[0067] (5) Because the inner diameter R2 of the cord guard 50 is larger than the outer diameter R1 of the power cord 60, the cord guard 50 can be detached from the power cord 60. This means that the cord guard 50 can be replaced when it becomes worn.

[0068] (6) The second length W2 being 1 mm or more can prevent the small diameter portion 511 from being torn by a load applied to the cord guard 50. This allows the cord guard 50 to bend flexibly while maintaining its durability.

[0069] (7) By providing the bellows portion 51 and forming the outlet portion 54 in a trumpet shape, the cord guard 50 can be made compact and can be adapted to both cases where a relatively heavy load is applied to the cord guard 50 and cases where a relatively light load is applied to the cord guard 50.

[0070] (Other embodiments) Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments and can be implemented in various modified forms.

[0071] (a) In the above embodiment, the cord guard 50 includes the bellows portion 51, and the outlet portion 54 is formed in a trumpet shape, but the outlet portion 54 does not have to be formed in a trumpet shape as long as the cord guard 50 includes the bellows portion 51. In other words, the cord guard 50 is only required to withstand cases where a relatively heavy load is applied to the cord guard 50, and does not necessarily have to withstand cases where a relatively heavy load is applied to the cord guard 50.

[0072] (b) In the above embodiment, bellows portion 51 has four small diameter portions 511 and three large diameter portions 512, but the generalization of the embodiment is not limited to this. Bellows portion 51 may have a plurality of small diameter portions 511 and a plurality of large diameter portions 512.

[0073] (c) In the above embodiment, bellows portion 51 is disposed close to the center of intermediate portion 57, but the generalization of the embodiment is not limited to this. For example, bellows portion 51 may be disposed over the entire intermediate portion 57. Furthermore, bellows portion 51 may be disposed close to connection portion 55 of intermediate portion 57. Furthermore, bellows portion 51 may be disposed close to outlet portion 54 of intermediate portion 57.

[0074] (d) In the above embodiment, the external power supply is a single-phase AC power supply, but it may be a three-phase AC power supply.

[0075] (e) Multiple functions possessed by one component in the above embodiments may be realized by multiple components, or one function possessed by one component may be realized by multiple components. Also, multiple functions possessed by multiple components may be realized by one component, or one function realized by multiple components may be realized by one component. Also, part of the configuration of the above embodiments may be omitted. Also, at least part of the configuration of the above embodiments may be added to or substituted for the configuration of another of the above embodiments. [Explanation of symbols]

[0076] 1...electric work machine, 20...housing, 33...rib, 35...pull-outlet, 50, 150, 250, 350...cord guard, 51...bellows portion, 52...second flat portion, 53...first flat portion, 54...outlet portion, 55...connection portion, 56...groove, 57...middle portion, 58...internal space, 60...power cord, 80...motor, 511...small diameter portion, 512...large diameter portion.

Claims

1. a housing having a withdrawal opening; a motor housed in the housing; a power cord that is pulled out from the outlet and connected to an external power source, and that is configured to supply power from the external power source to the motor; a cord guard having an internal space through which the power cord passes, The code guard is a connection portion configured to be connected to the outlet; an outlet configured to expose the power cord to the outside from the outlet; an intermediate portion located between the connection portion and the outlet portion, the intermediate portion having a plurality of large diameter portions and a plurality of small diameter portions having outer diameters smaller than those of the plurality of large diameter portions; Each of the plurality of large diameter portions has a first length in an extension direction of the cord guard, Each of the plurality of small diameter portions has a second length in the extension direction, and the second length is shorter than the first length. Electric work equipment.

2. The outlet portion has a first inner diameter, the first inner diameter increasing with increasing distance from the intermediate portion. The electric operating machine according to claim 1 .

3. the housing includes a protrusion that protrudes from the inner surface of the outlet toward the inside of the outlet, The connecting portion includes a recess that is recessed radially inward of the cord guard and configured to engage with the protrusion. The electric operating machine according to claim 1 or 2.

4. the plurality of large diameter portions and the plurality of small diameter portions are arranged toward the center of the intermediate portion, The electric operating machine according to any one of claims 1 to 3.

5. the power cord has a first outer diameter; the intermediate portion has a second inner diameter greater than the first outer diameter; The electric operating machine according to any one of claims 1 to 4.

6. The first length is three times the second length. The electric operating machine according to any one of claims 1 to 5.

7. The second length is 1 mm or more. The electric operating machine according to any one of claims 1 to 6.

8. A cord guard configured to be attached to a power cord pulled out from an outlet of a housing, An internal space is formed through which the power cord passes, a connection portion configured to be connected to the outlet; an outlet configured to expose the power cord to the outside from the outlet; an intermediate portion located between the connection portion and the outlet portion, the intermediate portion having a plurality of large diameter portions and a plurality of small diameter portions having outer diameters smaller than those of the plurality of large diameter portions; Each of the plurality of large diameter portions has a first length in an extension direction of the cord guard, Each of the plurality of small diameter portions has a second length in the extension direction, and the second length is shorter than the first length. Code Guard.

9. The outlet portion has a first inner diameter, the first inner diameter increasing with increasing distance from the intermediate portion. The cord guard according to claim 8.

10. The outlet includes a protrusion that protrudes radially inward of the cord guard, The connecting portion is recessed radially inward and includes a recess configured to engage with the protrusion.

10. The cord guard according to claim 8 or 9.

11. the plurality of large diameter portions and the plurality of small diameter portions are arranged toward the center of the intermediate portion, The cord guard according to any one of claims 8 to 10.

12. the power cord has a first outer diameter; the intermediate portion has a second inner diameter greater than the first outer diameter; The cord guard according to any one of claims 8 to 11.

13. The first length is three times the second length. The cord guard according to any one of claims 8 to 12.

14. The second length is 1 mm or more. The cord guard according to any one of claims 8 to 13.

Images