JP5698035B2 - Electric tool - Google Patents

Description

  The present invention relates to an electric power tool, and more particularly to an electric power tool provided with a safety lock mechanism capable of restricting / releasing the operation of the trigger lever in order to prevent erroneous operation of the trigger lever for starting a drive source.

  2. Description of the Related Art Conventionally, there is known an electric tool provided with a safety lock mechanism capable of restricting / releasing the operation of the trigger lever in order to prevent erroneous operation of the trigger lever that activates the drive source. For example, Patent Literature 1 below discloses a brush cutter used for cutting grass such as turf and weed. In this brush cutter, a trigger lever (with respect to a grip portion provided at one end of a handle is used. Power switch) and safety button (safety switch) are provided, and by simultaneously holding the trigger lever (power switch) and safety button (safety switch) by hand, the motor that is the driving source rotates. It is configured.

Japanese Patent No. 4071242

  However, the conventional electric power tool represented by the above-mentioned Patent Document 1 has many points to be improved. For example, the safety button (safety switch) described in Patent Document 1 is installed at a position where the operator always presses the grip, which is the grip, so that the motor can be safely rotated while holding the grip. It is not possible to respond to the request to stop. Therefore, it can be said that the safety lock mechanism described in Patent Document 1 has an insufficient configuration.

  Further, in the case of the brush cutter described in Patent Document 1, since a plurality of relatively large switches are installed with respect to the shape of the grip, there is a difficulty in operability.

  Furthermore, in the case of the brush cutter described in Patent Document 1, the safety lock mechanism based on the safety button (safety switch) is configured by an electrical circuit. However, in order to improve safety, a physical safety lock is provided. It is preferable to employ a mechanism. However, in the prior art, there is no safety lock mechanism with high safety and high operability.

  The present invention has been made in view of the problems existing in the above-described prior art, and an object thereof is to provide an electric tool including a safety lock mechanism with high safety and operability.

  The present invention will be described below. In addition, in order to make an understanding of this invention easy, the reference number of an accompanying drawing is attached in parenthesis writing, However, This invention is not limited to the form of illustration by it.

The power tool (10) according to the present invention is capable of regulating / releasing the trigger lever (41) for starting the drive source and the operation of the trigger lever (41) to prevent erroneous operation of the trigger lever (41). The safety lock mechanism (51) is a power tool (10) provided in the grip portion (40), and the safety lock mechanism (51) always protrudes from the surface of the grip portion (40). with a freely safety button pushing with a finger of the operator (52), the safety button (52) operatively driven in response to the, the Ru member der bar-shaped extending along the trigger lever (41) the lock plate in (54), and when the safety button (52) is in a normal state protruding from the surface of the grip portion (40), (41) and the lock plate (54) are brought into contact with each other, so that the operation of the trigger lever (41) is restricted, and when the operator pushes the safety button (52) with a finger, the trigger When the contact state between the lever (41) and the lock plate (54) is released, the operation restriction of the trigger lever (41) is released, and the safety button (52) is supported by the trigger lever (41). And a finger hook portion (41b) in which a contact portion (54b) of the lock plate (54) with the trigger lever (41) is a power point of the trigger lever (41). provided in the vicinity of) the inside of the grip portion (40), a plurality of guide walls for guiding the driving movement of the lock plate (54) ( 5, 45 a), and at least one of the plurality of guide walls (45, 45 a) has the trigger lever (41) restricted in operation so that the trigger lever (41) and the lock plate (54) In the contact state, the lock plate (54) is formed at a position capable of supporting the pressing force applied to the contact portion .

  In the electric tool (10) according to the present invention, one of the safety button (52) and the lock plate (54) is inclined with respect to the pushing direction (X) of the safety button (52). In addition to the inclined surfaces (53a, 53b), one of the other includes engaging sliding portions (55a, 55b) that engage with the inclined surfaces (53a, 53b), and the inclined surfaces (53a, 53b) and the The lock plate (54) is configured to be driven in a direction (Y) substantially orthogonal to the pushing direction of the safety button (52) by the action of the engagement sliding portions (55a, 55b). Can be.

  Moreover, in the electric tool (10) according to the present invention, the inclined surfaces (53a, 53b) are two opposing surfaces inside the hook shape (52b) of the safety button (52) or the lock plate (54). The engagement sliding portions (55a, 55b) are respectively formed on the lock plate (54) or the safety button (engaged with the hook shape (52b)). 52) formed on the engaging portion (54a), the inclined surfaces (53a, 53b) formed as a pair of opposing surfaces, and the engagement formed on the engaging portion (54a). The sliding portions (55a, 55b) can be engaged with each other in a slidable state.

  Furthermore, in the electric tool (10) according to the present invention, the lock plate (54) constantly receives the elastic force from the elastic member (56) installed in the grip portion (40), and the elastic member ( 56) is applied to the safety button (52) via the lock plate (54), so that the safety button (52) protrudes from the surface of the grip portion (40) in a normal state. Can be.

  Furthermore, in the electric tool (10) according to the present invention, the lock plate (54) and the trigger lever (41) when the operation of the trigger lever (41) is regulated by the lock plate (54). The contact surface of the contact portion may be configured as a surface parallel to the drive direction of the lock plate (54).

  Furthermore, in the electric tool (10) according to the present invention, the lock plate (54) and the trigger lever (41) when the operation of the trigger lever (41) is regulated by the lock plate (54). The contact surface of the contact portion may be configured as a surface having an inclination angle (θ) with respect to the driving direction of the lock plate (54).

  ADVANTAGE OF THE INVENTION According to this invention, an electric tool provided with the safety lock mechanism of high safety | security and operativity can be provided.

It is an external appearance perspective view for demonstrating the whole structure of the brush cutter which concerns on this embodiment. It is an external appearance perspective view of the holding part which concerns on this embodiment, and draws the left side surface at the time of seeing a holding part from diagonally left back. It is an external view which shows the back side surface of the holding part which concerns on this embodiment. It is a figure for demonstrating the internal structure of the holding part which concerns on this embodiment, and removes the right half member of the holding part comprised by right-and-left half structure, and when the inside of a holding part is seen from the right side FIG. It is the external appearance perspective view which showed the safety button which is a structural member of the safety lock mechanism which concerns on this embodiment. It is the external appearance perspective view which showed the lock plate which is a structural member of the safety lock mechanism which concerns on this embodiment. It is the schematic for demonstrating the arrangement | positioning relationship between the trigger lever which concerns on this embodiment, and a safety lock mechanism. It is a figure for demonstrating operation | movement of the safety lock mechanism which concerns on this embodiment, and is the figure which showed the mode inside the holding part of a safety lock mechanism especially while showing the state which locked the trigger lever. It is a figure for demonstrating operation | movement of the safety lock mechanism which concerns on this embodiment, and is the figure which extracted and drawn only the safety lock mechanism while showing the state which locked the trigger lever especially. It is a figure for demonstrating operation | movement of the safety lock mechanism which concerns on this embodiment, and is the figure which showed the mode inside the holding part of a safety lock mechanism while showing the state which especially locked the trigger lever. It is a figure for demonstrating operation | movement of the safety lock mechanism which concerns on this embodiment, and is the figure which extracted and drawn only the safety lock mechanism while showing the state which especially unlocked the trigger lever. It is the figure which showed an example of the various deformation | transformation form which the safety lock mechanism which concerns on this embodiment can take.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments for carrying out the invention will be described with reference to the drawings. The following embodiments do not limit the invention according to each claim, and all combinations of features described in the embodiments are not necessarily essential to the solution means of the invention. Moreover, in the following embodiment, the case where the electric tool which concerns on this invention is comprised as a brush cutter is illustrated and demonstrated.

  FIG. 1 is an external perspective view for explaining the overall configuration of the brush cutter according to the present embodiment. In the following description, for convenience of description, a direction corresponding to the usage state of the brush cutter 10 is defined. That is, as shown in FIG. 1, the side on which the cutting blade portion 13 is installed is “front”, the driving portion 11 side is “rear”, the side on which the grip portion 40 is installed is “right”, and the left grip 21 The side will be called “left”.

  The brush cutter 10 according to the present embodiment includes an operating rod 12 formed in a shaft shape extending in the longitudinal direction, a cutting blade portion 13 installed on the front side that is one end side of the operating rod 12, and an operating rod 12 Are provided on the rear side, which is the other end side, and include a drive unit 11 provided with a motor as a drive source therein, and a handle 14 installed at an intermediate portion in the longitudinal direction of the operation rod 12.

  The operation rod 12 is constituted by a hollow rod-like pipe member, and a driven shaft (not shown) is housed in a rotatable state therein. A cutting blade portion 13 is attached to the front end of the operation rod 12, and the holder 13a of the cutting blade portion 13 is made of a disk-shaped metal having a plurality of saw blade-shaped blade portions formed on the outer peripheral surface. The cutting blade (not shown) can be attached in a rotatable state. Since the holder 13a rotates in accordance with the rotational movement of the driven shaft, the cutting blade (not shown) rotates by the rotation of the holder 13a so that the grass and the like can be cut off. In addition, a protective cover 13b is provided in the immediate vicinity of the back of the cutting blade so as to cover part of the cutting blade. Is secured. For cutting blades (not shown), all types of cutting blades can be used, such as disc-shaped metal, ceramics, and multiple strings extending radially from the center of rotation. It has become.

  A handle 14 having a grip 40 and a left grip 21 is attached to an intermediate portion in the longitudinal direction of the operation rod 12. In addition, a hook 15 to which a shoulder belt (not shown) can be attached is installed behind the position where the handle 14 is installed in the operating rod 12. The operator stably operates the brush cutter 10 by holding the grip portion 40 and the left grip 21 included in the handle 14 with both hands and by hanging a shoulder belt attached to the hook 15 around the shoulder. It is possible. The installation position of the handle 14 can be set to an arbitrary position of the operation rod 12, but the balance between the drive unit 11 storing a heavy object such as a motor and the cutting blade unit 13 having a relatively light weight. In consideration of the above, it is desirable to install the handle 14 on the rear side of the intermediate portion of the operation rod 12.

  Heretofore, the overall configuration of the brush cutter 10 according to the present embodiment has been described. Next, the structure of the grip part 40 which is a significant feature of the brush cutter 10 according to the present embodiment will be described. Here, FIG. 2 is an external perspective view of the gripping portion according to the present embodiment, and depicts the left side when the gripping portion 40 is viewed from the diagonally left rear. FIG. 3 is an external view showing a rear side surface of the grip portion according to the present embodiment. Further, FIG. 4 is a diagram for explaining the internal configuration of the gripping portion according to the present embodiment, in which the right half member 40b of the gripping portion 40 configured by the left and right half-split structure is removed and the gripping portion 40 is removed. It is a figure at the time of seeing the inside of from the right side.

The grip portion 40 according to the present embodiment is configured to have a substantially vertically long outer shape, and has a configuration in which halved members 40a and 40b that can be divided into left and right are stacked. Two half-split elements 40a, the 40b, (in the present embodiment, the left half member 40a) either one screw groove 40a ₁ is formed, in the other one (in this embodiment, the right half members screw holes 40b ₁ to 40b) are formed, by screwing the screw into the screw groove 40a ₁ through screws (not shown) with respect to the screw hole 40b _1, half member 40a, by integrating 40b is gripped The unit 40 is configured. The grip portion 40 configured in this way is configured as a grip portion whose rear center portion indicated by an arrow G receives grip from an operator, and the grip portion 40 includes a motor as a driving source. The trigger lever 41 for activating is installed in a state in which it can be tilted with respect to the front of the grip portion G.

  As shown in detail in FIG. 4, the trigger lever 41 of the present embodiment includes a support shaft 41 a serving as a tilting center (fulcrum) of the tilting operation, and a finger hooking portion 41 b serving as a power point that receives a force from the operator's finger. It is comprised. In addition, a trigger coil spring 42 that exerts an elastic force on the trigger lever 41 is installed at a position between the support shaft 41a and the finger hanging portion 41b. The trigger coil spring 42 exerts an elastic force so as to push the trigger lever 41 in the direction in which the trigger lever 41 is always protruded from the grip portion 40, that is, the right side in FIG.

  Further, the trigger lever 41 is formed with a switch pressing piece 41c at a position opposite to the position where the finger hanging portion 41b is formed with respect to the support shaft 41a. When the trigger lever 41 performs a tilting operation with the support shaft 41a as the center of tilting, the switch pressing piece 41c moves along with the tilting operation, thereby turning on the micro switch 43 installed in the grip portion 40. Is configured to do. Since the micro switch 43 and a motor (not shown) installed in the drive unit 11 are electrically connected by a wiring cord, the trigger lever 41 is operated to operate a trigger source 41 (not shown). The motor can be started.

  Therefore, the operator arranges the palm of the right hand with respect to the grip part G, hangs the middle finger, ring finger, little finger, etc. of the right hand on the finger hook part 41b of the trigger lever 41, and the trigger lever 41 is gripped by the grip part G with the finger. The trigger lever 41 tilts about the support shaft 41a as the center of tilt while resisting the elastic force of the trigger coil spring 42 and moves to the inside of the grip portion 40. Then, with this tilting operation, the switch pressing piece 41c moves and the micro switch 43 is turned on, so that a motor (not shown) that is a driving source is activated and the brush cutter 10 can be operated. It has become.

  A protrusion 41 d that defines the end of the movement stroke in the direction protruding from the grip 40 is formed at the lowest position of the trigger lever 41. Since the protrusion 41d is configured to abut against a part of the inner wall of the grip 40, the protrusion 41d always receives the elastic force from the trigger coil spring 42 in the direction protruding from the grip 40. In the normal state of the trigger lever 41, the protrusion 41d exhibits the function of positioning the trigger lever 41.

  Now, in order to prevent erroneous operation of the trigger lever 41, a safety lock mechanism 51 that can freely restrict / release the operation of the trigger lever 41 is installed in the grip portion 40 according to the present embodiment. A specific configuration of the safety lock mechanism 51 will be described with reference to FIGS. 5 is an external perspective view showing a safety button that is a component of the safety lock mechanism according to the present embodiment. FIG. 6 shows a lock plate that is a component of the safety lock mechanism according to the present embodiment. It is the external appearance perspective view shown. FIG. 7 is a schematic view for explaining the arrangement relationship between the trigger lever and the safety lock mechanism according to the present embodiment. 8A to 9B are diagrams for explaining the operation of the safety lock mechanism according to the present embodiment. 8A and 8B show a state where the trigger lever 41 is locked, and FIGS. 9A and 9B show a state where the trigger lever 41 is unlocked. 8A and 9A are views showing the inside of the grip 40 of the safety lock mechanism 51 according to the present embodiment, and FIGS. 8B and 9B are only the safety lock mechanism 51 according to the present embodiment. It is the figure which extracted and drew.

  The safety lock mechanism 51 according to the present embodiment includes a safety button 52, a lock plate 54, and a lock coil spring 56.

  As shown in FIG. 2 and the like, the safety button 52 is installed in a state protruding from the surface of the grip portion 40 in a normal state. The safety button 52 has a configuration that can be pushed in by an operator's finger. As shown in FIG. 5, the shape of the safety button 52 includes a button portion 52a that receives an operation from the operator, and a hook portion 52b that is formed in a hook shape so as to be connected to the button portion 52a. Has been. The hook portion 52b is formed with two button-side inclined surfaces 53a and 53b as a pair of opposing surfaces formed with respect to two opposing surfaces on the inner side in the hook shape. These two button-side inclined surfaces 53a and 53b are formed as inclined surfaces having an inclination angle of 45 degrees with respect to the pushing direction of the safety button 52 (direction of the symbol X), as shown in FIGS. 8B and 9B. Yes.

  On the other hand, the lock plate 54 is a rod-like member extending along the trigger lever 41, and an engagement portion 54 a that engages with the hook portion 52 b of the safety button 52 is formed above the lock plate 54. The engaging portion 54a has a gate shape and has an opening, and the opening of the engaging portion 54a fits in a slidable manner with respect to the hook shape of the hook portion 52b. It is configured to be able to. Further, plate-side inclined surfaces 55a and 55b formed as a pair of non-opposing surfaces are formed inside and above the gate-shaped opening of the engaging portion 54a. The plate-side inclined surfaces 55a and 55b formed as a pair of non-facing surfaces are configured as inclined surfaces opposed to the button-side inclined surfaces 53a and 53b of the safety button 52, respectively. It has a function as an engagement sliding part engaged with button side slope 53a, 53b formed as follows.

  Accordingly, the button-side inclined surface 53a formed on the hook portion 52b of the safety button 52 and the plate-side inclined surface 55a formed on the engaging portion 54a of the lock plate 54 are disposed to face each other. A button-side slope 53b formed on 52b and a plate-side slope 55b formed on the engaging portion 54a of the lock plate 54 are disposed to face each other. All of these four inclined surfaces 53a, 53b, 55a, 55b are configured to have an inclination angle of 45 degrees with respect to the pushing direction of the safety button 52 (the direction of the symbol X in FIGS. 8B and 9B). Therefore, when the safety button 52 moves in the push-in direction (the direction of the symbol X), the lock plate 54 is configured to perform a relative movement in a direction orthogonal to the push-in direction (the direction of the symbol X). .

  The lock plate 54 has an abutting portion 54b at the end opposite to the portion where the engaging portion 54a is formed. The contact portion 54b regulates the operation of the trigger lever 41 by being in contact with the trigger lever 41, and restricts the operation of the trigger lever 41 by releasing the contact state with the trigger lever 41. It is a part which cancels.

  Further, the lock plate 54 is provided with a locking coil spring 56 and has a spring locking convex portion 54 c at a position where the elastic force from the locking coil spring 56 is received. By installing the locking coil spring 56 to the spring locking projection 54c, the lock plate 54 can reliably receive the elastic force exerted from the locking coil spring 56. Yes.

  The safety button 52, the lock plate 54, and the lock coil spring 56 described above are installed in combination with each other with respect to the inside of the grip portion 40, as shown in FIG. 2, FIG. 4, FIG. Thus, the safety lock mechanism 51 is configured. Specifically, as shown in FIG. 2, the safety button 52 protrudes the button portion 52a to a place where the thumb is positioned when the operator holds the grip portion 40 with the right hand. Has been placed. The safety button 52 is engaged with an engaging portion 54 a of a lock plate 54 with respect to a hook portion 52 b of the safety button 52. The lock plate 54 that engages with the safety button 52 is disposed at a position along the trigger lever 41, and is locked between the spring locking convex portion 54 c of the lock plate 54 and the rib inside the grip portion 40. A coil spring 56 is installed. Therefore, the lock plate 54 always applies a pressing force to the safety button 52 by the action of the coil spring 56 for locking. The direction of this pressing force is a force directed upward in the drawing in FIGS. 4 and 7, but the lock plate 54 and the safety button 52 are inclined surfaces formed in a direction of 45 degrees with respect to this pressing force direction. Since it is in an engaged state via 53a, 53b, 55a, 55b, the upward pressing force from the lock plate 54 is converted into the orthogonal direction by the action of the inclined surfaces 53a, 53b, 55a, 55b, and the safety button 52 is gripped. The pressing force is received in a direction protruding from the surface of the portion 40.

  In the normal state of the safety lock mechanism 51 described above, the contact portion 54b formed on the lock plate 54 is in contact with the trigger lever 41, so that the movement of the trigger lever 41 is restricted and cannot be operated. (See FIG. 8A). The contact surface of the contact portion between the contact portion 54b of the lock plate 54 and the trigger lever 41 when the operation of the trigger lever 41 is regulated by the lock plate 54 is relative to the drive direction of the lock plate 54. It is configured as parallel surfaces. Therefore, the contact portion 54 b of the lock plate 54 can reliably receive the pressing force exerted from the trigger lever 41.

  In order to release the lock state of the trigger lever 41, the operator may press the safety button 52 with a finger. That is, when the operator pushes the safety button 52 with a finger to move the hook portion 52b of the safety button 52, the lock plate 54 of the safety button 52 is moved by the action of the button side slopes 53a and 53b and the plate side slopes 55a and 55b. It is driven in a direction orthogonal to the pushing direction (downward direction in FIG. 4 and FIG. 7). When the lock plate 54 moves downward in FIG. 4 and FIG. 7, the contact state between the trigger lever 41 and the lock plate 54 is released, so that the operation restriction of the trigger lever 41 is released and the trigger lever 41 is operated. Is possible, that is, a state in which the brush cutter 10 can be activated (see FIG. 9A).

  In the safety lock mechanism 51 according to the present embodiment, the safety button 52 is provided in the vicinity of the support shaft 41a that is the fulcrum of the trigger lever 41, and the contact portion of the lock plate 54 with the trigger lever 41 (that is, The contact portion 54 b) is provided in the vicinity of the finger hook portion 41 b that is the power point of the trigger lever 41. The reason why such a configuration is adopted is that a reliable locked state cannot be realized unless the pressing force for the safety lock is applied to a place close to the power point. For example, when the contact portion 54b is disposed at a position close to the fulcrum of the trigger lever 41 where the safety button 52 is easy for the operator to operate, the pressing force for safety lock operates the trigger lever 41 by the lever principle. Since it loses the force to do, it will become impossible to maintain a locked state reliably. However, if the contact portion 54b is arranged at a position close to the power point of the trigger lever 41 as in the present embodiment, the pressing force for operating the trigger lever 41 can be reliably received, and the safety lock Therefore, the pressing force for the trigger lever 41 is not defeated by the pressing force for operating the trigger lever 41, so that the locked state of the trigger lever 41 can be reliably maintained.

  Note that various configurations are added to the safety lock mechanism 51 according to the present embodiment to enhance operability and safety. For example, a plurality of guide walls 45 are formed inside the grip portion 40 in order to guide the drive operation of the lock plate 54 that is driven in the vertical direction in FIG. The guide wall 45 is a member that also functions as a rib for increasing the strength of the grip portion 40.

  Further, the guide wall 45a formed in the vicinity of the contact portion 54b of the lock plate 54 is controlled when the operation of the trigger lever 41 is restricted and the trigger lever 41 and the lock plate 54 are in contact. For example, even when the trigger lever 41 is pressed regardless of the locked state, the pressing force applied to the contact portion 54b of the lock plate 54 is reduced. The upper guide wall 45a can be reliably received via the lock plate 54. Therefore, the guide wall 45a exhibits a function of helping to maintain a reliable locked state and realize a stable operation of the safety lock mechanism 51.

Furthermore, the grip portion 40 according to the present embodiment is a member configured by combining the half members 40a and 40b with fastening means, but the guide wall 45a described above is provided so as to be close to the fastening means installation position. ing. That is, in this embodiment, the two half-split elements 40a, 40b are formed a thread groove 40a ₁ is in one of, the other one has screw holes 40b ₁ are formed, with respect to the screw holes 40b ₁ not by screwing the screw into the screw groove 40a ₁ through the illustrated screw, half-split elements 40a, although 40b is configured such that the grip portion 40 are integrated, thus thread groove 40a ₁ and screw installation position of the fastening means consists of holes 40b ₁ and the screw or the like, has a portion having a higher strength than elsewhere grip portion 40. It is preferable to install the guide wall 45a as described above so as to be close to a portion having such a high strength because the pressing force applied to the contact portion 54b of the lock plate 54 can be more reliably received.

  In addition, about the guide wall 45 formed in multiple inside the holding | grip part 40, it is preferable that the height dimension of the guide wall 45 is formed larger than the width dimension of the lock plate 54. FIG. By making the height dimension of the guide wall 45 larger than the width dimension of the lock plate 54, the assemblability of the safety lock mechanism 51 with respect to the inside of the grip portion 40 is improved, so that the productivity is improved and the manufacturing cost is reduced. Can be obtained.

  Further, regarding the lock plate 54 of the present embodiment, a meat stealing shape 54 d is formed in a direction facing the plurality of guide walls 45. By forming the meat stealing shape 54d, the cross-sectional shape of the lock plate 54 becomes substantially H-shaped (or substantially n-shaped), and the strength can be improved. Further, by forming the meat stealing shape 54d, the moldability of the lock plate 54 is improved, and the manufacturing cost can be reduced by reducing the defective rate during molding. Furthermore, since the material for forming the lock plate 54 can be reduced by adopting the meat stealing shape 54d, the material cost can be reduced and the weight can be reduced. Furthermore, since the meat stealing shape 54d of the present embodiment is formed in a direction facing the plurality of guide walls 45, the contact state between the lock plate 54 and the guide walls 45 is not a surface contact but a more contact area. Point contact with less. Therefore, the lock plate 54 according to the present embodiment in which the meat stealing shape 54d is adopted has high slidability and can realize a stable driving operation.

  The configuration of the safety lock mechanism 51 included in the brush cutter 10 of the present embodiment has been described above. Next, with reference to FIGS. 8A to 9B, the operation method and operation of the gripping unit 40 according to the present embodiment including the safety lock mechanism 51 will be described.

  In the normal state, the grip portion 40 according to the present embodiment is in a state where the operation of the trigger lever 41 is restricted by the lock plate 54 as shown in FIGS. 8A and 8B. When the operator presses the safety button 52 with his / her finger from such a normal state, the hook portion 52b of the safety button 52 moves in the direction of X. When the hook portion 52b is moved in the direction of the symbol X, the button side inclined surfaces 53a and 53b are also moved in the direction of the symbol X. Therefore, the engaging portion 54a engaged with the hook portion 52b is opposed to the button side inclined surface 53a. , 53b and the plate-side inclined surfaces 55a, 55b move downward in the drawing. That is, the state shown in FIG. 8B is shifted to the state shown in FIG. 9B. As a result, the lock plate 54 is driven in a direction orthogonal to the pushing direction of the safety button 52 (the downward direction in FIG. 8A and FIG. 9A), so that the trigger as shown in FIG. The contact state between the lever 41 and the lock plate 54 is released, and the contact portion between the trigger lever 41 and the lock plate 54 is shifted as shown in FIG. The operation of the trigger lever 41 is released by fitting into the groove of the trigger lever 41. In the state shown in FIG. 9A in which the lock is released, the contact portion 54b of the lock plate 54 is formed in the groove of the trigger lever 41 even if the operator pushes the safety button 52 away from the safety button 52. Since it fits in the hole, the trigger lever 41 can be continuously pushed in.

  After that, when the operator releases the push of the trigger lever 41 to stop the brush cutter 10, the contact portion 54 b of the lock plate 54 fitted in the groove of the trigger lever 41 extends from the groove of the trigger lever 41. The lock plate 54 that has received the elastic force of the locking coil spring 56 is driven in the upward direction in FIG. 8A and FIG. 9A. Then, contrary to the previous case, the engaging portion 54a of the lock plate 54 presses the hook portion 52 of the safety button 52 in the direction of the symbol Y in FIGS. 8B and 9B (upward in the drawing in FIGS. 8B and 9B). Will do. The safety button 52 that has received a pressing force in the direction of the symbol Y (the upward direction in FIG. 8B and FIG. 9B) is affected by the action of the plate-side inclined surfaces 55a and 55b and the button-side inclined surfaces 53a and 53b. It will move to the left side of the page in 9B. That is, the state shown in FIG. 9B is shifted to the state shown in FIG. 8B. As a result, the safety button 52 returns to the normal state, and the lock state of the trigger lever 41 by the lock plate 54 is realized.

  As mentioned above, although preferred embodiment of this invention was described, the technical scope of this invention is not limited to the range as described in the said embodiment. Various modifications or improvements can be added to the embodiment.

  For example, in the above-described embodiment, the contact surface of the contact portion between the contact portion 54 b of the lock plate 54 and the trigger lever 41 when the operation of the trigger lever 41 is regulated by the lock plate 54 is the lock plate 54. It was comprised as a surface parallel to the drive direction. However, the contact surface of the contact portion between the contact portion 54b of the lock plate 54 and the trigger lever 41 when the operation of the trigger lever 41 is regulated by the lock plate 54 is relative to the drive direction of the lock plate 54. It is also possible to configure it as a surface with an inclined angle. Specifically, as shown in FIG. 10, the abutting surface is inclined so that the pressing force from the trigger lever 41 presses the lock plate 54 upward in the drawing, and the inclination angle θ is set to several degrees to 10 degrees. By setting the degree, the movement direction of the lock plate 54 at the time of locking (downward on the paper surface in FIG. 10) and the action direction of the pressing force from the trigger lever 41 (upward on the paper surface in FIG. 10) are reversed. Thus, the unlocking operation of the safety lock mechanism 51 while pushing the trigger lever 41 becomes difficult. That is, by providing the contact surface with the inclination angle θ, it is possible to prevent the locked state from being immediately shifted to the activated state, so that a highly safe power tool (the brush cutter 10) can be realized. It becomes possible.

  In addition, for the four slopes 53a, 53b, 55a, and 55b that face each other in a slidable state, a solid lubricant is applied by applying a lubricant or performing a surface treatment to improve the slidability. Or form a linear bearing structure formed by interposing rolling elements such as balls and rollers in a rolling path formed by a pair of opposed half grooves. Can be.

  Furthermore, in the above-described embodiment, the button-side inclined surfaces 53a and 53b are formed as inclined surfaces on the safety button 52 side, and the plate-side inclined surfaces 55a and the engagement sliding portion are formed on the lock plate 54 side. The case where 55b was formed was described as an example. However, in the present invention, it is possible to adopt a configuration in which the engagement sliding portion is formed on the safety button side and the inclined surface is formed on the lock plate side.

  Further, the engaging sliding portions formed as the plate-side inclined surfaces 55a and 55b do not necessarily have to be formed as inclined surfaces, and are related to the inclined surfaces such as the button-side inclined surfaces 53a and 53b of the present embodiment. It is only necessary to have a slidable shape. That is, the shape of the engagement sliding portion is, for example, a shaft body in addition to the shape in surface contact with the inclined surface such as the plate-side inclined surfaces 55a and 55b formed as a pair of non-opposing surfaces exemplified in the present embodiment. It can also be made point-contact with the inclined surface by being formed as a shape.

  Furthermore, in the above-described embodiment, the case where the features of the present invention are applied to the brush cutter 10 is described as an example. However, the feature of the present invention is not limited to the brush cutter 10 but the gripping portion of the present invention. The present invention can be applied to any type of electric tool that can be installed.

  Furthermore, in the above-described embodiment, the case where the inclination angles of the four inclined surfaces 53a, 53b, 55a, and 55b are set to 45 degrees has been described as an example. However, the inclined surfaces according to the present invention (the button-side inclined surface and the plate-side inclined surface). Various inclination angles can be changed. For example, by adopting a slope with an inclination angle (for example, 60 degrees) that is more than 45 degrees with respect to the pushing direction of the safety button 52 (the direction of X in FIGS. 8B and 9B), the safety button 52 It is possible to increase the amount of movement of the lock plate 54 with respect to the pushing amount of 52. With this configuration, the locked state can be realized even when the pressing amount of the safety button 52 is small compared to the case of the present embodiment described above.

  It is apparent from the description of the scope of claims that embodiments with such changes or improvements can be included in the technical scope of the present invention.

DESCRIPTION OF SYMBOLS 10 Brush cutter, 11 Drive part, 12 Operating rod, 13 Cutting blade part, 13a Holder, 13b Protective cover, 14 Handle, 15 Hook, 21 Left grip, 40 Gripping part, 40a, 40b Half member, 40a ₁ screw groove , 40b ₁ screw hole, 41 trigger lever, 41a support shaft, 41b finger hooking part, 41c switch pressing piece, 41d protrusion, 42 trigger coil spring, 43 micro switch, 45 guide wall, 45a (near lock plate contact part) Guide wall, 51 Safety lock mechanism, 52 Safety button, 52a Button part, 52b Hook part, 53a, 53b Button side slope, 54 Lock plate, 54a Engagement part, 54b Contact part, 54c Spring lock Convex part, 54d meat steal shape, 55a, 55b plate side slope, 56 coil spring for locking, G Grip part.

Claims (6)

In an electric tool provided with a gripping portion, a trigger lever that activates a drive source and a safety lock mechanism that can freely restrict / release the operation of the trigger lever in order to prevent erroneous operation of the trigger lever,
The safety lock mechanism is
A safety button that is always protruding from the surface of the gripping part and can be pushed in by an operator's finger;
Wherein it is driven according to the operation of the safety button, and the lock plate Ru member der bar-shaped extending along the trigger lever,
Comprising
When the safety button is in a normal state protruding from the surface of the grip portion, the trigger lever and the lock plate are brought into contact with each other, so that the operation of the trigger lever is restricted, and the operator presses the safety button. When pushed with a finger, the operation restriction of the trigger lever is released by releasing the contact state between the trigger lever and the lock plate ,
The safety button is provided in the vicinity of a support shaft that is a fulcrum of the trigger lever, and the contact portion with the trigger lever in the lock plate is provided in the vicinity of a finger hooking portion that is a force point of the trigger lever .
A plurality of guide walls are formed inside the grip portion to guide the drive operation of the lock plate,
At least one of the plurality of guide walls is in a position capable of supporting the pressing force applied to the contact portion of the lock plate when the operation of the trigger lever is restricted and the trigger lever and the lock plate are in contact. An electric tool characterized by being formed . The power tool according to claim 1,
One of the safety button and the lock plate has an inclined surface with an inclination angle with respect to the pushing direction of the safety button, and the other has an engagement sliding portion that engages the inclined surface. Prepared,
The power tool is configured such that the lock plate is driven in a direction substantially orthogonal to the pushing direction of the safety button by the action of the inclined surface and the engagement sliding portion. In the electric tool according to claim 2,
The inclined surfaces are a pair of opposing surfaces formed with respect to two opposing surfaces inside the hook shape of the safety button or the lock plate,
The engaging sliding portion is formed with respect to an engaging portion formed on the lock plate or the safety button that engages the inside of the hook shape,
An electric tool characterized in that the inclined surfaces formed as a pair of opposing surfaces and the engaging sliding portion formed in the engaging portion are engaged and arranged in a slidable state. In the electric tool according to any one of claims 1 to 3,
The lock plate always receives an elastic force from an elastic member installed in the grip portion, and the elastic force from the elastic member is exerted on the safety button via the lock plate, whereby the safety button Projecting from the surface of the gripping part in a normal state. In the electric tool according to any one of claims 1 to 4,
The contact surface of the contact portion between the lock plate and the trigger lever when the operation of the trigger lever is regulated by the lock plate is configured as a surface parallel to the drive direction of the lock plate. An electric tool characterized by having In the electric tool according to any one of claims 1 to 4,
The contact surface of the contact portion between the lock plate and the trigger lever when the operation of the trigger lever is regulated by the lock plate is a surface that is inclined with respect to the drive direction of the lock plate. It is comprised, The electric tool characterized by the above-mentioned.

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