Impact tools

Abstract

To provide a construction technology which contributes to rationalization of an arrangement structure and operability of a member, concerning an impact tool normally performing a striking operation while facing downward due to self-weight.SOLUTION: In an impact tool 100 normally performing a striking operation while facing downward due to self-weight, a second housing 120 is configured to relatively move with respect to a first housing 110 along with a pair of handles 130 through an elastic body 161. Sliding guide members 190 and 200 which guide relative movement operation between the first housing 110 and the second housing 120 are respectively provided at a plurality of places in the first direction D1.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present disclosure relates to an impact tool, known as a large hammer, which normally performs impact work downward while hanging down under its own weight. [Background technology]

[0002] As an impact tool, the configuration of a so-called large hammer driven by a motor is disclosed in, for example, Japanese Patent Laid-Open Publication No. 2015-66628 (Patent Document 1). Patent document 1 discloses the configuration of a large hammer with an anti-vibration handle, in which an elastic body is interposed between the main body, which houses the drive mechanism and motor, and the handle main body, to which the handle is attached, to prevent vibrations from the main body from being transmitted to the handle main body.

[0003] Large hammers are heavy, large in size, and have a large output, so there is a strong demand for streamlining the component layout and operability. In particular, as part of the recent trend of technological development that emphasizes ESG (or SDGs), there is a strong demand for reduced environmental impact, high efficiency, and ergonomic design, and the development of large hammers is no exception.

[0004] In particular, when increasing the output of large hammers to improve efficiency, it is necessary to take effective measures against the strong vibrations that occur as a trade-off. Various proposals have been made for large hammers, but vibration countermeasures are particularly important from the perspective of protecting the functional components installed and reducing the burden on the operator, and there is a strong demand for further rationalization. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-66628 Summary of the Invention [Problem to be solved by the invention]

[0006] In view of the above, an object of the present invention is to provide a construction technique that contributes to rationalizing the arrangement of components and operability of an impact tool, the normal working mode of which is to perform impact work in a downward-facing position due to its own weight. [Means for solving the problem]

[0007] In order to solve the above problems, according to one aspect (aspect 1) of the present disclosure, The impact tool has a long body portion with a tool holder in a tip region, and a pair of handles extending in a second direction, where the longitudinal direction of the body portion is defined as a first direction and the width direction intersecting the first direction is defined as a second direction, and the worker holds the pair of handles in each hand and allows them to hang down under their own weight, allowing impact work to be performed via a tip tool detachably attached to the tool holder.

[0008] This impact tool has a drive mechanism that drives the bit in the first direction, a motor provided with a motor output shaft that drives the drive mechanism, a first housing and a second housing that are constituent members of the main body, and an elastic body that is interposed between the first housing and the second housing, wherein the drive mechanism and the motor are provided in the first housing, the pair of handles are provided in the second housing, and the second housing, together with the pair of handles, is configured to be movable relative to the first housing via the elastic body. Slide guide members for guiding the relative movement between the first housing and the second housing are provided at a plurality of locations in the first direction.

[0009] The impact tool is typically suitably applied to an impact tool that normally performs impact work in a downward position due to its own weight, i.e., a large hammer. In recent years, there has been a strong demand for large hammers to be more efficient by increasing their output, but this requires reliable measures to deal with the strong vibrations that occur as a trade-off. In particular, more effective vibration countermeasures are required from the perspective of protecting the functional components installed and reducing the burden on the operator.

[0010] For this reason, in the impact tool, an elastic body is interposed between a first housing, which is prone to vibration during impact work, and a second housing, which should suppress the transmission of vibration.The second housing, together with the pair of handles, is made movable relative to the first housing via the elastic body, thereby suppressing the transmission of vibration to the pair of handles (i.e., a vibration-proof handle configuration).

[0011] In the impact tool, the sliding guide members for guiding the relative movement between the first housing and the second housing are provided at a plurality of locations in the first direction. By using multiple sliding guide members to guide the sliding in the first direction, input components in directions other than the first direction between the first and second housings, which move relative to each other, are restricted, ensuring stable and smooth relative movement.

[0012] According to the present invention, a construction technique is provided that contributes to improving the arrangement of components and workability for an impact tool that normally performs impact work in a downward-facing position due to its own weight. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a front perspective view (worker's side) showing the overall configuration of an impact tool according to an embodiment of the present invention. [Figure 2] 1 is a rear perspective view showing the overall configuration of an impact tool according to an embodiment of the present invention. [Figure 3] 1 is a plan view of an impact tool according to an embodiment of the present invention; [Figure 4] 1 is a front cross-sectional view of an impact tool according to an embodiment of the present invention. [Figure 5]1 is a cross-sectional side view (right side view) of an impact tool according to the present embodiment. [Figure 6] 2 is an enlarged cross-sectional view of the side (right side) of the impact tool according to the embodiment. FIG. [Figure 7] FIG. 2 is an enlarged front cross-sectional view showing the configuration of an upper part of the impact tool according to the present embodiment. [Figure 8] 2 is a partial cross-sectional plan view showing the configuration of a first sliding guide member of the impact tool according to the present embodiment. FIG. [Figure 9] FIG. 3 is a partial cross-sectional plan view showing the configuration of a second sliding guide member of the impact tool according to the present embodiment. [Figure 10] FIG. 2 is a front right perspective view showing the upper internal structure of the impact tool with the head case removed. [Figure 11] FIG. 2 is a front left perspective view showing the upper internal structure of the impact tool with the head case removed. [Figure 12] FIG. 2 is a top perspective view showing the configuration of the controller case. [Figure 13] FIG. 2 is a bottom perspective view showing the configuration of the controller case. [Figure 14] FIG. 2 is a perspective view showing the configuration of a duct cover. [Figure 15] FIG. 2 is a perspective view of the configuration of the duct cover as viewed from the motor side, which is the attachment member. [Figure 16] FIG. 10 is a partial cross-sectional view of the left side surface showing the mounting configuration of the duct member. [Figure 17] FIG. 10 is a partial cross-sectional view of the left side surface showing the mounting configuration of the duct member. [Figure 18] FIG. 2 is a perspective view showing the configuration of a detection mechanism. [Figure 19] FIG. 4 is a partial cross-sectional view of a right side view showing the configuration of a detection mechanism in a no-load driving state. [Figure 20] FIG. 10 is a right side cross-sectional view showing the operation of the detection mechanism when switching from a no-load driving state to a load driving state. DETAILED DESCRIPTION OF THE INVENTION

[0014] The following exemplary embodiments can be appropriately adopted for the above-described configuration. A plurality of exemplary embodiments can also be appropriately combined and used for the above-described configuration. (Aspect 2) The elastic body may be disposed between the plurality of sliding guide members in the first direction. This, in combination with the first aspect, makes it possible to exert a more stable vibration damping effect. Note that "arranged between" multiple sliding guide members includes a mode in which the elastic body is arranged between the multiple sliding guide members while being spaced apart in the first direction, and a mode in which the elastic body is arranged between the multiple sliding guide members while being partially overlapping.

[0015] (Aspect 3) In the impact tool according to claim 1 or 2, the sliding guide member can be further arranged at a plurality of positions around the first direction. This allows for a more stable vibration damping effect to be achieved. Note that "plurality of locations around the first direction" encompasses both a state in which they are at exactly the same position (at the same height) in the first direction, and a state in which they are at slightly different heights.

[0016] (Aspect 4) the plurality of sliding guide members include a handle-proximate-side sliding guide member disposed close to the handle in the first direction, and a handle-farther-side sliding guide member disposed farther from the handle than the handle-proximate-side sliding member, The handle-proximal side sliding guide member may have a metal component provided on either the first housing or the second housing, and a resin component provided on the other housing that slides relative to the metal component. By placing one of the multiple sliding guide members close to the handle that the worker holds while pressing it, the transmission of vibrations during impact work can be more effectively suppressed, providing stable vibration-damping action. Furthermore, by configuring the handle-proximal side sliding guide member using metal components and resin components, it is possible to ensure the strength required for a sliding guide while also reducing its weight.

[0017] (Aspect 5) The metal component can be configured as a pipe-shaped member provided in the first housing and having a circumferential direction around the first direction, and the resin component can be configured as a bifurcated member provided in the second housing and connected to the metal component, which is the pipe-shaped member. By using a pipe-shaped member, the strength and durability of the sliding guide member can be improved. It is preferable that the pipe-shaped member be hollow to further ensure strength. It is sufficient that the pipe-shaped member has an arc-shaped portion, and it may be, for example, arc-shaped when viewed in the first direction. A bifurcated member can also be defined as a fork-shaped member or a branched member.

[0018] (Aspect 6) The handle-away side sliding guide member may have a convex member provided on either the first housing or the second housing and extending in the first direction, and a concave member provided on the other housing and engaging with the convex member. By utilizing the uneven structure, it is possible to improve the strength and durability of the sliding guide member and eliminate the adverse effects of input components other than those in the sliding guide direction.

[0019] (Aspect 7) A sliding guide made of sheet metal may be interposed between at least one of the convex member and the concave member. This makes it possible to further improve the strength and durability of the sliding guide member. The sheet metal sliding guide only needs to be interposed, and may be attached to either the first housing or the second housing.

[0020] (Aspect 8) The second housing may have a stopper that defines a maximum distance of relative movement of the second housing with respect to the first housing in the first direction. This makes it possible to prevent an incident such as a "bottom hit" that occurs when, for example, large vibrations act, increasing the amount of relative movement between the first and second housings, exceeding the variable amount of the elastic body and causing the first and second housings to come into direct contact with each other.

[0021] (Aspect 9) Furthermore, the second housing may include a buffer member that buffers the relative movement of the second housing when the second housing moves relative to the first housing by a predetermined distance that is less than a maximum movable distance. It is preferable that the buffer member continuously performs buffering from the predetermined distance to the maximum movable distance. The relative movement between the first and second housings is cushioned and received, and the stopper can guide the movement to the maximum movable distance, thereby improving the durability of the sliding guide member as well as its vibration-damping properties and texture.

[0022] (Aspect 10) When the elastic body is defined as a first elastic body, a second elastic body may be provided as an initial movement elastic body interposed between the first housing and the second housing, and the spring force of the second elastic body may be applied when the second housing moves relative to the first housing within a predetermined initial movement distance.

[0023] (Aspect 11) When the second housing moves relative to the first housing beyond the initial movement distance, the biasing forces of both the first elastic body and the second elastic body may act. Preferably, the elastic constant of the second elastic body is set to be smaller than the elastic constant of the first elastic body, thereby more clearly distinguishing the characteristics and roles of the two, such as the first elastic body being for initial action and the second elastic body being for vibration damping. For example, at the initial movement of pressing the second housing against the first housing, the biasing force of the second elastic body is applied, and initial movement detection can be performed using the biasing force of the second elastic body. On the other hand, when the initial movement distance is exceeded and the impact work begins in earnest, the biasing force of the first elastic body can be firmly applied between the first and second housings, and the characteristics and roles of the first elastic body for vibration isolation and the second elastic body for initial movement detection can be differentiated, further streamlining the device configuration and further improving workability.

[0024] (Aspect 12) The second elastic body may be located above the first elastic body, when the direction from the handle to the tool holder is defined as downward and the direction from the tool holder to the handle is defined as upward in the first direction. As a result, the second elastic body, which operates in response to the operator's operation, is positioned closer to the operator, and the first elastic body, which provides vibration-damping functionality, is positioned closer to the source of vibration, such as the cutting tool or drive mechanism, thereby achieving an arrangement that is in line with the functions of both.

[0025] (Aspect 13) The second housing may be provided with a battery mounting section into which a battery for supplying power to the motor can be mounted, and a battery protector that protects at least a portion of the battery's outer casing from external forces when the battery is mounted in the battery mounting section. This makes it possible to mount the battery on the second housing side where vibration input from the first housing is suppressed, and furthermore, the outer casing of the battery can be protected from external forces, thereby improving the protection performance of the battery and the battery mounting section.

[0026] An impact tool 100 according to this embodiment will be described below with reference to FIGS. 1, 2 and 3 show the overall configuration of an impact tool 100 as a front perspective view, a rear perspective view and a plan view, respectively. 4 and 5 show a front cross-sectional view and a side cross-sectional view, respectively, of the impact tool 100, FIG. 6 shows a partially enlarged cross-sectional view of the side of the impact tool 100, and FIG. 7 shows an enlarged front cross-sectional view of the upper structure of the impact tool 100. In this embodiment, for convenience, the side facing the operator is defined as the front of the impact tool 100.

[0027] In this embodiment, for convenience of explanation, the longitudinal direction of the impact tool 100 (also referred to as the longitudinal direction: the vertical direction on the paper in FIG. 1) is defined as a first direction D1. The width direction (also referred to as the left-right direction: the left-right direction on the paper in FIG. 1) intersecting the long axis direction is defined as a second direction D2. The thickness direction of the impact tool 100, which is perpendicular to the first direction D1 and the second direction D2, is defined as a third direction D3. Furthermore, with regard to the first direction D1, the direction toward the bottom of the paper surface in FIG. 1 is defined as D1D, and the direction toward the top of the paper surface is defined as D1U.

[0028] (Overall composition) As shown in FIGS. 1 to 6, the impact tool 100 generally includes a first housing 110 and a second housing 120 in external view. The second housing 120 is connected to the upper side of the first housing 110 in the first direction D1 and is movable relative to the first housing 110. (Configuration of the first housing 110) The first housing 110 is formed in an elongated shape and has an upper drive mechanism accommodating portion 111 , a lower drive mechanism accommodating portion 112 , and a tip region 113 . Further, a side area 114 is formed in the upper drive mechanism accommodating portion 111 and the lower drive mechanism accommodating portion 112 at their portions on the second direction D2 side. The upper drive mechanism housing portion 111, the lower drive mechanism housing portion 112, and the tip region 113 are arranged in this order from top to bottom in a connected manner in the first direction D1.

[0029] The upper drive mechanism housing section 111 mainly houses the motor 210 and the motion conversion mechanism 170. The lower drive mechanism housing section 112 mainly houses the impact mechanism 180. The motion conversion mechanism 170 and the impact mechanism 180 are examples of a configuration corresponding to the "drive mechanism." The motor 210, the motion conversion mechanism 170, and the impact mechanism 180 will be described in detail below. The tip region 113 is provided with a tool holder 240 and a retainer 250 . The tool holder 240 is a tool mounting member used in striking work, and the retainer 250 functions as a retaining member for preventing the tool bit mounted on the tool holder 240 from coming off. For convenience, the tool tip is not shown in the drawings.

[0030] (Configuration of second housing 120) The second housing 120 is provided above the first housing 110 in the first direction D1 and connected to the first housing 110. The second housing 120 has a head case 121, a handle attachment portion 122, and a battery attachment portion 123. Head case 121 forms the outer shell of second housing 120 and mainly houses controller 260 and controller case 270 (see also FIGS. 10 and 11, etc.). A cooling air intake port 127 is provided on the top surface of head case 121 above in the first direction D1U.

[0031] The handle attachment parts 122 are arranged in pairs in the second direction D2, are integrally connected to the head case 121, and have handles 130, which will be described later, attached thereto. The battery mounting parts 123 are provided in pairs in the second direction D2, connected to the handle attachment part 122 on the lower side in the first direction D1D, and each has a battery 150, which will be described later, mounted thereon.

[0032] The battery mounting portion 123 is configured to be disposed in a side region 114 of the first housing 110, in a region 130A of the second housing 120 directly below the handle attachment portion 122 in the first direction D1. The battery mounting section 123 also has a slide guide 124 for when the battery is mounted and a power supply terminal 125 (see FIG. 4). Each battery mounting section 123 also has a battery protector 128 for protecting the outer shell of the battery 150 mounted in the battery mounting section 123 from external forces.

[0033] The head case 121, the handle attachment portion 122, and the battery attachment portion 123 including the battery protector 128 are integrally connected to form the second housing 120, and are configured to be movable integrally relative to the first housing 110 in the first direction D1. The detailed configuration of the relative movement of the second housing 120 with respect to the first housing 110 will be described later.

[0034] (Configuration of handle 130) The handle 130 has a pair of first and second handle portions 131 and 141 that extend from the first housing 110 in the second direction D2 in a protruding manner. Typically, the first handle portion 131 is adapted to be held by an operator's right hand, and the second handle portion 141 is adapted to be held by an operator's left hand. As shown in detail in Fig. 3, the first handle portion 131 has a first handle base portion 132, a first handle grip portion 133, and a free end region 134. A trigger 135 is provided on the first handle grip portion 133. The trigger 135 is normally biased to the OFF position, and can be moved to the ON position against the biasing force toward the OFF position by manually pressing the trigger 135 while gripping the first handle portion 131. Figs. 1 to 4 show the trigger 135 in the OFF position (initial state).

[0035] When the operator releases the pressing operation of the trigger 135, the trigger 135 is returned to its initial state by the biasing force toward the OFF position. As shown in Fig. 4, the trigger 135 is connected to an electric switch 136 provided in the handle attachment part 122. When the trigger 135 moves to the ON position, the electric switch 136 is turned ON, and an ON signal is sent to the controller 260, which will be described later. The second handle portion 141 has a second handle base portion 142 , a second handle grip portion 143 , and a free end region 144 .

[0036] (Configuration of battery 150) As shown in Figures 1 to 3, battery 150 is a generally rectangular cube having a battery front surface 151, a battery top surface 152, a battery bottom surface 153, and a battery rear surface 154, and is configured as a package that houses a battery pack consisting of multiple batteries. Furthermore, an unlocking portion 155 is provided on the battery upper surface portion 152 in an area adjacent to the battery rear surface portion 154. The unlocking portion 155 is manually operated when the battery 150 is to be removed from the second housing 120. 3, the battery 150 is attached to the battery attachment portion 123 of the second housing 120 by sliding it in a battery attachment direction 156. As a result, the battery 150 is electrically connected to the power supply terminal 125 while engaged with the slide guide 124 in the battery attachment portion 123, and is placed in a state in which it can supply power to the impact tool 100.

[0037] The battery mounting direction 156 is defined as a direction that intersects (is perpendicular to) the first direction D1 and the second direction D2 and is aligned with the third direction D3. On the other hand, the battery 150 is removed from the second housing 120 by manually operating the lock release portion 155 and sliding it in the direction opposite to the battery mounting direction 156. In other words, the battery mounting direction 156 and the removal direction (the direction opposite to the battery mounting direction 156) intersect (are perpendicular to) the first direction D1 and the second direction D2.

[0038] The above-mentioned battery protector 128 covers the battery front surface 151, the battery top surface 152, the battery bottom surface 153 (and part of the battery side surfaces) when the battery 150 is attached to the battery attachment portion 123, thereby protecting the battery 150 from external forces. In other words, the battery protector 128 has a configuration as a cover member that covers all or part of the battery front surface 151, the battery top surface 152, and the battery bottom surface 153. 4, an LED light 129 that illuminates the tip region 113 or the tip of the tool bit is provided on the lower surface (downward in the first direction D1D) of the battery protector 128. The LED light 129 is one of the functional members that assists in the performance of the impact work.

[0039] In this embodiment, the battery 150 attached to the battery attachment portion 123 is configured to be positioned, together with the battery protector 128, inside the imaginary line HL connecting the free end regions 134, 144 of the first handle portion 131 and the second handle portion 141 to the tip region 113 of the first housing 110 (on the side closer to the impact tool 100 than the imaginary line HL), as shown in FIG. This prevents the battery 150 and battery protector 128 attached to the battery attachment portion 123 from interfering with the impact work. Furthermore, in the unlikely event that the impact tool 100 falls over, the battery 150 (and battery protector 128) is positioned inside the imaginary line HL, which is assumed to be a ground line, and thus can avoid the impact when the impact tool 100 falls over, thereby further improving protection against external forces.

[0040] (Configuration of motor 210) 5 and 6, the motor 210 is mainly composed of a stator 211, a rotor 212, an output shaft 213 integrally connected to the rotor 212, and a cooling fan 214 integrally connected to the output shaft 213. In this embodiment, a centrifugal fan is used as the cooling fan 214. Each element of the motor 210 is housed in a motor housing 215 and is disposed within the first housing 110 . The output shaft 213 is connected to the first intermediate shaft 171 of the motion conversion mechanism 170 described above on the opposite side from the operator in the third direction D3 so as to be able to transmit rotation at a predetermined reduction ratio, and the rotational output from the motor 210 is transmitted from the output shaft 213 to the motion conversion mechanism 170 via the first intermediate shaft 171. In this embodiment, a brushless motor is used as the motor 210 in order to obtain a relatively large output while maintaining a relatively small size. The structure of a brushless motor is well known, and therefore a detailed description thereof will be omitted in this specification.

[0041] The output shaft 213 is disposed so as to intersect the first direction D1 and the second direction D2 and extend along the third direction D3. In other words, the output shaft 213, which is likely to have the largest dimension among the motor 210, is disposed so as to extend in the third direction D3, which is the thickness direction of the impact tool 100. This allocates the largest dimension of the motor 210 to the third direction D3, and instead ensures a large space for arranging other functional components along the second direction D2, which is the width direction of the impact tool 100.

[0042] 1 and 4, it becomes easier to ensure space in the side region 114 of the first housing 110 in the second direction D2. In this embodiment, the expansion space S ensured in the side region 114 is utilized to provide the battery mounting section 123 as part of the second housing 120, and even when the battery 150 is mounted in the battery mounting section 123 or when the battery protector 128 is arranged, space efficiency is optimized so as not to interfere with work.

[0043] (Configuration of motion conversion mechanism 170) As shown in FIGS. 5 and 6, the motion converting mechanism 170 is mainly composed of a first intermediate shaft 171, a second intermediate shaft 172, a crank mechanism 173, a cylinder 174, a piston 175, an air chamber 176, and a vibration damping mechanism 177. As described above, the first intermediate shaft 171 is connected to the output shaft 213 of the motor 210 so as to be able to transmit rotation, and further the first intermediate shaft 171 is connected to the second intermediate shaft 172 so as to be able to transmit rotation at a predetermined reduction ratio. The second intermediate shaft 172 is integrally connected to the crank mechanism 173 and is connected to the vibration suppression mechanism 177 so as to be able to drive the vibration suppression mechanism 177 .

[0044] The crank mechanism 173 converts the rotational motion of the second intermediate shaft 172 about the third direction D3 into linear motion in the first direction D1, causing the piston 175 to reciprocate linearly in the first direction D1. The linear motion of the piston 175 causes pressure fluctuations in the air chamber 176 in the cylinder 174.

[0045] The vibration suppression mechanism 177 has a counterweight 178 that reciprocates linearly in the first direction D1 along the outer periphery of the cylinder 174. The counterweight 178 is a member that operates in opposition to the impact action of the impact mechanism 180 described below, and suppresses vibrations that occur in the impact tool 100 during impact work.

[0046] (Configuration of the impact mechanism 180) 5 and 6, the striking mechanism 180 is mainly composed of a striker 181 and an impact bolt 182. As described above, when a pressure fluctuation occurs in the air chamber 176 inside the cylinder 174, the striker 181, which is also located inside the cylinder 174 and faces the piston 175 across the air chamber 176, moves linearly in the first direction D1, causing the impact bolt 182 to move linearly in the first direction D1.

[0047] As a result, the impact bolt 182 linearly moves a tool bit (not shown for convenience) attached inside the tool holder 240, and the tool bit performs an impact operation in the first direction D1. The retainer 250 prevents the bit from coming off in the first direction D1. The retainer 250 is movable between a position for preventing the tool bit from coming off (corresponding to FIG. 5) and a release position by rotating about a rotation center 251 in FIG.

[0048] (Configuration of the first sliding guide member 190) As described above, first housing 110 and second housing 120 are configured to be capable of relative movement in first direction D1. In this embodiment, as shown in FIGS. 7 to 9, a first sliding guide member 190 and a second sliding guide member 200 are provided to facilitate the relative movement. The first sliding guide member 190 is provided in a position close to the handle 130 in the first direction D1 (at a height position substantially equal to that of the handle 130). The first sliding guide member 190 has a pipe-shaped member 191, which is a component on the first housing 110 side, and a bifurcated member 192, which is a component on the second housing 120 side. The bifurcated member 192 is a member having paired portions that are literally bifurcated, and is also called a forked member or bifurcated member. The pipe-shaped member 191 is made of metal, has a circular cross section, and is fixedly disposed in the first housing 110 with its major axis facing the first direction D1. The bifurcated member 192 is made of resin, and is fixed integrally with the handle 130 to the handle attachment portion 122 of the second housing 120. The bifurcated member 192 is arranged in a loose fit manner in the pipe-shaped member 191 with the bifurcated portions along the outer circumferential surface of the pipe-shaped member 191, and is configured to be slidably movable relative to the pipe-shaped member 191 in the first direction D1. In this embodiment, a plurality of first sliding guide members 190 are arranged around the first direction D1 (two are arranged in pairs facing each other as shown in FIG. 8).

[0049] (Configuration of the second sliding guide member 200) The second sliding guide member 200 is disposed on the lower side in the first direction D1D than the above-described first sliding guide member 190. Specifically, in relation to the first direction D1, the second sliding guide member 200 is disposed in the vicinity of the battery 150 (at a height position substantially equal to that of the battery 150). The second sliding guide member 200 has a convex member 201 , a concave member 202 , and a sliding guide 203 .

[0050] The convex member 201 is made of resin, is fixedly provided on the first housing 110 side, and is configured to protrude outward in the second direction D2 as shown in FIG. The concave member 202 is made of resin and is provided on the second housing 120 side, and as shown in FIG. 9, is fitted with the convex member 201 in a state in which they are relatively slidable in the first direction D1. The sliding guide 203 is formed by bending a thin metal plate, and as shown in Figure 9, it is welded and fixed to the first housing 110, and is positioned between the convex member 201 and the concave member 202 to guide the relative sliding movement of the convex member 201 and the concave member 202 while providing rigidity reinforcement. Furthermore, in this embodiment, a plurality of second sliding guide members 200 are arranged around the first direction D1 (as shown in FIG. 9, two are arranged in pairs facing each other).

[0051] The second sliding guide member 200 is provided with a buffer member 205. The buffer member 205 is capable of coming into contact with a buffer member abutment seat 126 on the second housing 120 side. The buffer member abutment seat 126 has a wedge-shaped cross section and is formed integrally with the battery mounting portion 123 of the second housing 120. The buffer member 205 is made of an elastic material such as rubber, urethane, or sponge, and is fixedly attached to the first housing 110. Specifically, the buffer member 205 is provided on the back surface side of the convex member 201, as shown in FIG. When the first housing 110 and the second housing 120 move relatively toward each other, the buffer member 205 is compressed by the buffer member abutment seat 126 on the second housing 120 side. This compression buffers the relative movement between the first housing 110 and the second housing 120.

[0052] The impact tool 100 according to this embodiment further includes a stopper 204 . As shown in FIG. 7, the stopper 204 receives the bifurcated member 192 on the second housing 120 side, thereby determining the maximum distance of relative movement (i.e., the movable stroke distance) between the first housing 110 and the second housing 120 in the first direction D1.

[0053] (Arrangement of multiple sliding guide members) In this embodiment, with respect to the first direction D1, the first sliding guide member 190 constitutes the handle-proximal-side sliding guide member, and the second sliding guide member 200 constitutes the handle-distant-side sliding guide member. The relative movement of the first housing 110 and the second housing 120 is supported in the first direction D1 by multiple sliding guide members, thereby ensuring stability of the movement. Furthermore, as shown in Figures 8 and 9, multiple first sliding guide members 190 and multiple second sliding guide members 200 are arranged around the first direction D1, which further ensures stability in the relative movement of the first housing 110 and the second housing 120.

[0054] (Vibration-proof structure) As shown in Figures 4 and 7, the first housing 110 and the second housing 120 are configured to be able to move relative to each other (closer to or farther away from each other) in the first direction D1 with a first elastic body 161 and a second elastic body 162 interposed therebetween when a biasing force is applied. In this embodiment, a metal coil spring is used for each of the first elastic body 161 and the second elastic body 162. Alternatively, for example, a leaf spring, rubber, soft resin, an actuator, or the like can also be used.

[0055] The first elastic body 161 is disposed between the first housing 110 and the second housing 120, on the lower side in the first direction D1D of the handle 130. In this embodiment, the first elastic body 161 is configured as a pair structure. As shown in FIG. 7, the lower end of the first elastic body 161 is attached to a first elastic body mounting seat 120A provided in the upper drive mechanism accommodating portion 111. On the other hand, the upper end of the first elastic body 161 is placed in a free end state with the pressing seat 120C attached thereto. 7, the pressing seat 120C has an L-shaped cross section, and the bottom of the L-shaped cross section is fitted into the upper end of the first elastic body 171. On the other hand, the upper end of the L-shaped cross section is disposed opposite the bifurcated member 192 on the first housing 110 side.

[0056] Before the impact operation is started (initial state), the upper end of the pressing seat 120C and the bifurcated member 192 of the first sliding guide member 190 are disposed opposite each other with a predetermined clearance 190CL between them. In this embodiment, the clearance 190CL is set to two millimeters (2 mm).

[0057] When the first housing 110 moves relatively downward in the first direction D1D and approaches the second housing 120, the bifurcated member 192 first descends along the pipe-shaped member 191 a distance equivalent to the clearance 190CL and abuts against the upper end of the pressing seat 120C of the first elastic body 161.

[0058] Furthermore, as the first housing 110 moves downward in the first direction D1D, the bifurcated member 192 compresses the first elastic body 161 via the pressing seat 120C. As a result, the biasing force of the second elastic body 162, which is generated in response to the compression, acts between the first housing 110 and the second housing 120.

[0059] In this embodiment, the first elastic body 161 is disposed in the first direction D1 between the first sliding guide member 190, which is the handle-proximal-side sliding guide member, and the second sliding guide member 200, which is the handle-remote-side sliding guide member. This allows the biasing force to act in a so-called double-end supported state, and avoids adverse effects of biasing force components other than those in the first direction D1 (such as the generation of a tilting force during relative movement). The first elastic body 161 is disposed in a region directly below the first sliding guide member 190 in the first direction D1, and the vibration damping effect on the handle 130 is improved.

[0060] On the other hand, the second elastic body 162 in this embodiment is disposed between the first housing 110 and the second housing 120, on the upper D1U side of the handle 130 in the first direction. In this embodiment, the second elastic body 162 is configured as a pair structure (also see FIG. 10, etc.). An end portion on one side (upper side in the first direction D1U) of each second elastic body 162 is attached to a second elastic body attachment portion 278 (second housing 120 side) of the controller case 270. The detailed structure of the controller case 270 is also shown in Figures 12 and 13. On the other hand, an end portion on the other side (lower side in the first direction D1D) of each second elastic body 162 is attached to a second elastic body attachment seat 120B (first housing 110 side). Thus, the second elastic body 162 is interposed between the first housing 110 and the second housing 120 .

[0061] When an operator holds the handle 130 and presses it downward in the first direction D1D, the second housing 120 integrated with the handle 130 moves relatively downward in the first direction D1D against the biasing force of the second elastic body 162, and moves closer to the first housing 110.

[0062] The first elastic body 161 and the second elastic body 162 are "Elastic modulus of first elastic body 161>Elastic modulus of second elastic body 162" It is set to be. Specifically, the first elastic body 161 (a coil spring in this embodiment) is determined to have a relatively large elastic modulus to an extent that it can effectively suppress the transmission of vibrations generated on the first housing 110 side during impact work to the second housing 120 side, i.e., to fully ensure the vibration-proof housing structure of the impact tool 100.

[0063] On the other hand, the second elastic body 162 is (1) When no impact work is being performed, it is sufficient to hold the weight of the second housing 120, the functional components attached to the second housing, and the battery 150, in other words, to hold heavy objects on the second housing 120 side away from the first housing 110. and, (2) When starting the impact operation, the elastic constant is set to an extent that the operator can press the handle 130 downward in the first direction D1D to move the second housing 120 relative to the first housing 110, in other words, to an extent that the second housing 120 can be easily pressed manually toward the first housing 110.

[0064] (Internal configuration of the first housing 110 with the head case 121 removed) 10 and 11 show the internal configuration of the upper side of the impact tool 100 with the head case 121 shown in FIG. 1 removed.

[0065] Fig. 10 shows the upper internal structure of the impact tool 100 as viewed from the front right side with the head case 121 removed. On the other hand, Fig. 11 shows the upper internal structure of the impact tool 100 as viewed from the front left side with the head case 121 removed. The second housing 120 connected to the first housing 110 on the upper D1U side in the first direction holds the controller 260, a controller case 270 that holds the controller 260, a main power switch 281, a communication unit 282, and a detection mechanism 290.

[0066] The controller 260 is a component that mainly controls the drive of the motor 210. The controller 260 is configured as an assembly that houses a control board and has heat dissipation fins 261 formed on the upper surface, i.e., a control board assembly. The control board mainly includes a CPU, memory, etc. The main power switch 281, the communication unit 282, and the detection mechanism 290 all constitute a functional member 280 for assisting the impact tool 100 in carrying out the impact work.

[0067] The second housing 120, while holding the above-mentioned components, is connected to the first housing 110 with the second elastic body 162 interposed therebetween. The biasing force of the second elastic body 162 acts on both the first housing 110 and the second housing 120 in the first direction D1.

[0068] Meanwhile, the first housing 110 holds a motor housing 215, which houses the motor 210, at its upper end on the upper D1U side in the first direction. A duct cover 220 is connected to the motor housing 215. As shown in FIG. 6 , the duct cover 220 is connected to the motor housing 215 at an end region of the output shaft 213 of the motor 210 that faces the cooling fan 214, out of both end portions thereof. As shown in FIG. 11, a duct member 230 is connected between the duct cover 220 and the controller case 270.

[0069] The detailed configuration of each component will be described below in order. (Configuration of controller case 270) The detailed configuration of the controller case 270 is shown in Figures 12 and 13. Of these, Figure 12 is a perspective view of the controller case 270 from the top side, and Figure 13 is a perspective view of the controller case 270 from the bottom side. The controller case 270 is mainly composed of a frame 271 with a frame structure that functions as a holder for the controller 260, and the frame 271 is integrally molded with a duct member mounting portion 272, a head case mounting portion 273, a detection mechanism mounting portion 274, a main power switch mounting portion 275, a communication unit mounting portion 276, a wire harness insertion opening 277, and a second elastic body mounting portion 278. Although not specifically shown, lead wires (electrical wires) for electrically connecting the controller 260 to the battery 150, the motor 210, the electric switch 136, etc. are inserted and held in the wire harness insertion opening 277. The lead wires may be either single wires or multiple wires bundled together.

[0070] (Configuration of duct cover 220) The detailed structure of the duct cover 220 is shown in perspective views in FIGS. FIG. 14 is a perspective view of the front side of the duct cover 220, and FIG. 15 is a perspective view of the duct cover 220 as seen from the side of the motor 210, which is the member to be attached. Duct cover 220 has an internal space 221, a motor mounting seat 222, a flange 223, a cooling air guide path 224, and a duct member mounting portion 225. The cooling air that has cooled controller 260 is sent to motor 210 through duct member mounting portion 225 of duct cover 220, cooling air guide path 224, and internal space 221 (also see FIG. 11).

[0071] The duct cover 220 configured in this manner is screwed to the motor housing 215 using the motor mounting seat 222 (see also FIGS. 10 and 11). As shown in Fig. 6, the duct cover 220 is attached to the motor housing 215 at the end (the operator's side) of the output shaft 213 of the motor 210 opposite the end where the cooling fan 214 is attached, in the third direction D3. Therefore, when the cooling fan 214 rotates together with the output shaft 213, the cooling air is sent to the motor housing 215 by the axial flow action of the cooling fan 214 via the duct member attachment portion 225, the cooling air guide path 224, and the internal space 221 in the duct cover 220 shown in Fig. 15, and then circulates within the motor housing 215 along the output shaft 213 in the third direction D3. This cools the motor 210 housed in the motor housing 215.

[0072] (Configuration of duct member 230) 11, 16 and 17 show the details of the duct member 230. Of these, Figure 16 is a cross-sectional view in the second direction of the left side surface cut in the first direction D1 so as to pass through the central axis of the first end 232 of the duct hose 231 in Figure 11, and Figure 17 is a cross-sectional view in the second direction of the left side surface cut in the first direction D1 so as to pass through the central axis of the second end 233 of the duct hose 231 in Figure 11. The duct member 230 is a member for supplying the cooling air that has cooled the controller 260 to the motor housing 215, and is mainly composed of a duct hose 231.

[0073] The duct hose 231 has a first end 232 connected to a duct member mounting portion 272 of the controller case 270 (see also Figures 12 and 13), and a second end 233 connected to a duct member mounting portion 225 of the duct cover 220. As a result, the duct member 230 is disposed between the first housing 110 and the second housing 120 in an intervening manner.

[0074] 16, the first end 232 of the duct hose 231 is directly and fittedly attached to the duct member attachment portion 272 of the controller case 270. In other words, the first end 232 is directly fitted to the duct member attachment portion 272 without using any auxiliary equipment such as an adapter (without using an adapter). 17, the second end 233 of the duct hose 231 is directly and fitted to the duct member mounting portion 225 of the duct cover 220 connected to the motor 210. In other words, the second end 233 is directly fitted to the duct member mounting portion 225 without using any auxiliary equipment such as an adapter (without using an adapter).

[0075] The duct hose 231 in this embodiment is made of a member that applies a biasing force to the contraction side so that the duct hose 231 returns to the initial state when it is stretched from a predetermined initial state. In this embodiment, a hose with a bellows structure is used. In this embodiment, duct hose 231, stretched by a predetermined amount from its initial state, is arranged in a connected state between first housing 110 and second housing 120. Therefore, duct hose 231 is constantly subjected to a biasing force toward the contraction side so as to return to its initial state. As a result, the duct hose 231 always tries to contract, so it does not loosen unnecessarily inside the impact tool 100, and a structure is obtained that can avoid wear due to friction with other components even when the first housing 110 and the second housing 120 move relative to each other. Specifically, by employing a vibration-proof structure, the connection distance between first housing 110 and second housing 120 by duct hose 231 is shortened from the initial state. In this case, if no biasing force toward the contraction side is applied to duct hose 231, unnecessary slack will occur in duct hose 231 due to the shortened connection distance, and this slack will cause friction with other components, etc. In this embodiment, by employing duct hose 231 in which a biasing force acts toward the contraction side so as to return to a predetermined initial state, such problems can be prevented.

[0076] 11, the cross section of first end 232 of duct hose 231, that is, the end portion on the controller case 270 side, which is on the upward first direction D1U side, is a plane formed by second direction D2 and third direction D3. In other words, the central axis of the upper end side of duct hose 231 is configured to be along first direction D1. On the other hand, the cross section of the second end 233 of the duct hose 231, that is, the end portion on the duct cover 220 side, which is on the downward first direction D1D side, is a surface formed by the first direction D1 and the second direction D2. In other words, the central axis of the lower end side of the duct hose 231 is configured to be along the third direction D3.

[0077] As a result, the cross sections of first end 232 and second end 233 are configured to intersect with each other. That is, the central axis of first end 232 is along the first direction, and the central axis of second end 233 is along the second direction D2, so that the central axes intersect (are substantially perpendicular to each other). This configuration is advantageous from the viewpoint of avoiding twisting of duct hose 231 and application of unnecessary tension when duct hose 231 is connected between members whose distance changes relatively, particularly in a vibration-proof structure in which first housing 110 and second housing 120 move relative to each other.

[0078] The first end 232 of the duct hose 231 is configured to be located in an area adjacent to and above the cooling fan 214 of the motor 210 (see also FIGS. 4 and 5). 16 and other figures, cooling air intake port 127A is provided in head case 121 so as to correspond to at least the end portion of controller case 270 facing duct member attachment portion 272. This configuration allows cooling air to flow over a long distance from cooling air intake port 127A to first end 232 of duct hose 231 attached to duct member attachment portion 272 located at the opposite end, thereby improving the cooling effect of controller 260. In this embodiment, cooling air intake port 127 is formed not only at the end portion facing duct member attachment portion 272, but also in the center of the top surface of head case 121, thereby improving the intake efficiency of cooling air. As shown in FIG. 11, the duct hose 231 is placed in a state where the curved shape of the central portion is generally maintained by the duct portion guide rib 116 provided on the motor housing 215.

[0079] (Configuration of functional member 280) In this embodiment, as shown in Figures 3, 10, and 11, a main power switch 281, a communication unit 282, and a detection mechanism 290 are provided as examples of various functional components 280 that assist the impact tool 100 in performing impact work. The main power switch 281 is a start switch for energizing the impact tool 100. When an operator manually turns on the main power switch 281, the controller 260 starts controlling the drive of the impact tool 100 via power supply from the battery 150. When the operator manually switches the main power switch 281 to the ON position, the ON position is basically maintained until the switch is manually operated to return to the OFF position. However, in this embodiment, from the viewpoint of energy saving, etc., if no operation is performed for 60 seconds after the switch is turned on, the switch is automatically set to return to the off position. When the main power switch 281 is turned on, the operation lamp lights up to visually notify the operator that the power is on.

[0080] The communication unit 282 is a member for sending a drive control signal to an attachment member (auxiliary device) that is used together with the impact tool 100 for impact work. In this embodiment, a dust collector is used as the attachment member. Wifi, Bluetooth, etc. are used as communication methods.

[0081] (Configuration of detection mechanism 290) Furthermore, the configuration of the detection mechanism 290, which is one of the components of the functional member 280, will be described. The basic structure of the detection mechanism 290 is shown in FIGS. The detection mechanism 290 has an assembly base 291 , a movable member 292 provided with a magnetic body, a movable member biasing elastic body 293 , and a magnetic sensor 294 . The detection mechanism 290 is attached to a detection mechanism attachment portion 274 of the controller case 270 (see also FIGS. 12 and 13). The detection mechanism 290 is connected to the controller 260 by a wire harness (not shown for convenience) (see FIG. 10, etc.).

[0082] The movable member 292 is movable in the first direction D1 while being held by the assembly body base 291. The movable member biasing elastic body 293 is interposed between the movable member 292 and the assembly body base 291, and constantly applies a biasing force to the movable member 292 downward in the first direction D1D. 19, the lower end of the movable member 292 faces the upper end of the duct cover 220, and is configured to form a predetermined clearance 290CL in the initial state before the striking operation is performed. In this embodiment, the clearance 290CL is set to 1 mm (millimeter).

[0083] In this embodiment, in the initial state, the sensor 294 maintains a state in which it detects the magnetism of the movable member 292. In other words, in a state in which the sensor 294 detects the magnetism on the movable member 292 side, the controller 260 determines that the detection mechanism 290 is in the initial state. On the other hand, as shown in Figure 20, when the first housing 110 and the second housing 120 move relative to each other so as to approach each other, the clearance 290CL disappears as a result of the relative movement, and the lower end of the movable member 292 and the upper end of the duct cover 220 come into contact with each other.

[0084] When the first housing 110 and the second housing 120 further move relative to each other from this state so as to approach each other, the duct cover 220 pushes the movable member 292 upward in the first direction D1U while resisting the biasing force of the movable member biasing elastic body 293. When the movable member 292 moves upward in the first direction D1U, the sensor 294 stops detecting magnetism (no longer detects magnetism), and the controller 260 detects the pressing force of the impact tool 100 through the detection mechanism 290. That is, the detection mechanism 290 functions as a so-called push drive sensor. In this embodiment, the impact tool 100 is switched from an unloaded driving state to a loaded driving state by detecting the pressing force, and the detailed operation of this will be described later.

[0085] (Operational mode of the impact tool 100 according to this embodiment) The operation of the impact tool 100 according to this embodiment will be described below. The impact tool 100 according to this embodiment is configured as a so-called large hammer, and is normally used to perform impact work downward in a state in which the impact tool 100 hangs down due to its own weight. It should be noted that the terms "hanging" and "downward" used here do not only refer to directions that completely coincide with the downward first direction D1D, but can also include other directional components.

[0086] (Motor 210 energized: soft no-load start) When an operator performs impact work using the impact tool 100, he or she first grasps the handle 130 with his or her hand, places the impact tool 100 in a position where it hangs down under its own weight (with the tool holder 240 facing downward in the first direction D1D), and then manually turns on the main power switch 281. Furthermore, the operator manually turns on trigger 135 while holding handle 130. Based on the turning on of main power switch 281 and trigger 135, controller 260 drives motor 210 to rotate at a predetermined first speed (first rotation speed) R1.

[0087] A specific setting value of the first speed R1 is determined, for example, according to an idling setting that allows for a smooth transition to the subsequent normal driving operation (load driving state) while appropriately reducing power consumption. The first speed R1 is set to a relatively low speed range, thereby minimizing vibrations generated in the impact tool 100 via the vibration damping mechanism 177. This point will be described later.

[0088] The reason why the condition for energizing and driving the motor 210 is that both the main power switch 281 and the trigger 135 are turned on is to thoroughly prevent malfunction of the impact tool 100. Also, from the viewpoint of thoroughly preventing malfunction, the motor 210 is set not to be energized and driven even if the trigger 135 is turned on before the main power switch 281 is turned on. In this embodiment, as described above, a brushless motor is used for the motor 210, and when the main power switch 281 and the trigger 135 are turned on, the controller 260 controls the driving of the motor 210 by so-called PWM control.

[0089] (Definition of the no-load driving state of the impact tool 100) In this embodiment, a state in which the motor 210 is driven and the second housing 120 is not being pressed against the first housing 110 is defined as a "no-load driving state." This "no-load driving state" can also be defined as the following state: (1) Initial state before the impact work begins. (2) A state in which no load other than its own weight is acting on the cutting tool, i.e., the cutting tool is not intentionally pressed against the workpiece (other than its own weight) and is driven "without load." or, (3) A state in which the operator is not pressing the handle 130, i.e., a state in which no relative movement is occurring between the first housing 110 and the second housing 120, or a state in which neither the first elastic body 161 nor the second elastic body 162 is compressed. The no-load driving state is also called a "no-load driving state."

[0090] (Operation of the motion conversion mechanism 170) 5 and 6, when the motor 210 is driven to rotate, the rotational output of the output shaft 213 of the motor 210 around the third direction D3 is transmitted to the first intermediate shaft 171 and the second intermediate shaft 172 and converted into linear motion in the first direction D1 by the crank mechanism 173, whereby the piston 175 moves linearly in the first direction D1 within the cylinder 174. Similarly, the vibration suppression mechanism 177, mainly composed of a counterweight 178, moves linearly in the first direction D1 on the outer periphery of the cylinder 174, but in a different phase.

[0091] 5 and 6 moves due to its own weight from the position shown in Figures 5 and 6 toward the tip of the tool holder 240 in the downward first direction D1D, and the striker 181 also moves due to its own weight toward the tip of the cylinder 174 in the downward first direction D1D so as to be connected to the impact bolt 182. In other words, in the no-load driving state, the impact bolt 182 and the striker 181 are placed in a state of hanging down in the downward first direction D1D due to their own weights.

[0092] In this case, because striker 181 is located at the frontmost position within cylinder 174, air chamber 176 within cylinder 174 is open to the outside through vent hole 174A of cylinder 174 shown in Fig. 6, and even though piston 175 is being driven, no pressure fluctuation occurs within air chamber 176, and striker 181 is not actuated. For convenience, Fig. 6 shows the opposite state, in which air chamber 176 is not open to the outside through vent hole 174A, i.e., a load-driven state (described later).

[0093] In this case, as described above, the controller 260 drives the motor 210 to rotate at a predetermined first speed R1. However, since the first speed R1 is set to a relatively low speed range, the driving speed of the vibration damping mechanism 177 is also set to a relatively low speed range, and unnecessary vibrations generated in the impact tool 100 via the vibration damping mechanism 177 are minimized. In this embodiment, with regard to this state, the mode in which the motor 210 is driven at the first speed R1, which is a relatively low speed in the no-load driving state, is defined as a "soft no-load start." The soft no-load start is an operating mode in which the motor 210 is rotated at a low speed while the vibration generated by the vibration suppression mechanism 177 is minimized, thereby improving the response characteristics to the subsequent normal impact work.

[0094] In this embodiment, R1 is set to a predetermined value in the relatively low speed range, but it is also possible to set R1 to zero. In other words, it is also possible to select a setting that does not drive the motor 210 in the no-load driving state. In this case, the setting is focused on energy saving effects and vibration suppression in the no-load driving state, instead of the rise characteristics from the no-load driving state to the driving state.

[0095] When the impact tool 100 is in an unloaded driving state, the following characteristics are present: (1) The first elastic body 161 shown in Fig. 7 is in a non-compressed state, i.e., in a state where no biasing force is applied. A clearance 190CL (2 mm in this embodiment) is secured between the bifurcated member 192 of the first sliding guide member 190 and the pressing seat 120C. (2) The second elastic body 162 shown in FIG. 7 is placed in a non-compressed state, that is, in a state where no biasing force is applied. (3) In the detection mechanism 290 shown in FIG. 19, a clearance 290CL (1 mm in this embodiment) is ensured between the movable member 292 and the duct cover 220.

[0096] (Operational Mode 2 of the Impact Tool 100: Switching from Unloaded Driving State to Loaded Driving State) With the impact tool 100 in the unloaded driving state described above, when an operator presses the handle 130 downward in the first direction D1D, the second housing 120, which is integrated with the handle 130, moves closer to the first housing 110 on the downward D1D side in the first direction. Then, the controller case 270, which is a component of the second housing 120, also moves downward in the first direction D1D, compressing the second elastic body 162 via the second elastic body mounting portion 278 shown in FIG. 7 . The second elastic body 162 in the compressed state applies a biasing force to both the first housing 110 and the second housing 120.

[0097] 7, the first elastic body 161 has a clearance 190CL (2 mm) so that the bifurcated member 192 on the second housing 120 side does not reach the pressing seat 120C on the first elastic body 161 side, and the first elastic body 161 is placed in a non-compressed state, i.e., in a state where no biasing force is applied. In other words, the clearance 190CL defines the "initial movement distance" for the first elastic body 161 to be placed in a state where no biasing force is applied and only the second elastic body 162 applies a biasing force.

[0098] On the other hand, in the detection mechanism 290 shown in Figure 19, when the second housing 120 moves downward in the first direction D1D, the entire detection mechanism 290 moves downward in the first direction D1D by the amount of clearance 290CL (1 mm) between it and the duct cover 220, and the lower end of the movable member 292 abuts against the duct cover 220. Furthermore, when the second housing 120 moves downward in the first direction D1D, the movable member 292 is pushed by the duct cover 220 (which is trying to move relatively closer) and moves upward in the first direction D1U while resisting the biasing force of the movable member biasing elastic body 293. The movement of the movable member 292 upward in the first direction D1U cancels the detection of magnetism by the sensor 294. Based on this, the controller 260 detects the pressing of the second housing 120 against the first housing 110 through the detection mechanism 290, and thereby switches from the no-load drive state to the load drive state.

[0099] (Definition of the Load Driven State of the Impact Tool 100) In this embodiment, a state in which the motor 210 is driven and the second housing 120 is pressed against the first housing 110 is defined as a "load-driven state." This "load-driven state" is (1) A state in which a load other than the weight of the impact tool 100 acts on the bit, that is, a state in which the bit is pressed against the workpiece and driven while a "load" (other than the weight) acts on the bit. (2) It can also be defined as a state in which both the first elastic body 161 and the second elastic body 162 are compressed, or a state in which at least the second elastic body 162 is compressed and pressure is detected by the detection mechanism 290, etc. The load driving state is also called a "load driving state."

[0100] In the load driving state, the controller 260 drives the motor 210 to rotate at a predetermined second speed (second rotation speed) R2 that is set in a higher range than the first speed R1. The second speed R2 is also defined as a normal driving speed for impact work. That is, in this embodiment, based on detection by the detection mechanism 290, the rotation speed of the motor 210 increases (or the motor is switched from a stationary state to a normal rotation state), and the motor is switched from a no-load driving state to a loaded driving state. In other words, the above-mentioned soft no-load is released (canceled) by the detection by the detection mechanism 290, and switching to the normal drive pattern is performed. A specific setting value of the second speed R2 is set by comprehensively determining parameters such as the required output and power consumption during normal driving operation (load driving state) of the impact tool 100, which is a large hammer. The switching from the first speed R1 to the second speed R2 can be appropriately set from a mode of switching immediately, a mode of gradually increasing the speed after setting a certain switching time, a mode of increasing the speed in multiple stages, or a combination of these. In this embodiment, a mode is adopted in which the speed is immediately switched from the first speed R1 to the second speed R2 based on detection of pressure.

[0101] (Operational Mode of the Motion Conversion Mechanism 170 and the Impact Mechanism 180 in a Load-Driven State) When the motor 210 is rotationally driven at the second speed R2 in the loaded driving state, the operation of the motion converting mechanism 170 is substantially the same as when the motor 210 is rotationally driven at the low speed of the first speed R1 in the unloaded driving state, except for the difference in speed. That is, as shown in Figures 5 and 6, the rotational output of the output shaft 213 of the motor 210 around the third direction D3 is transmitted to the first intermediate shaft 171 and the second intermediate shaft 172 and converted into linear motion in the first direction D1 by the crank mechanism 173, thereby linearly moving the piston 175 in the first direction D1 within the cylinder 174. Similarly, the vibration suppression mechanism 177, mainly composed of a counterweight 178, performs linear motion in the first direction D1 on the outer periphery of the cylinder 174.

[0102] When the impact tool 100 is in a load-driving state, the vent hole 174A is in the state shown in FIG. 6, i.e., in a state not facing the air chamber 176, and the air chamber 176 is maintained in an airtight state between the piston 175 and the striker 181. Therefore, in the load driving state, the pressure fluctuation in the air chamber 176 caused by the linear motion of the piston 175 in the cylinder 174 causes the striker 181 in the impact mechanism 180 to move linearly, driving the impact bolt 182. This causes the tool tip (not shown) to perform an impact operation. This operation mode is defined as the hammer mode.

[0103] In this case, as described above, the controller 260 drives the motor 210 to rotate at a predetermined second speed R2, but since the second speed R2 is set to a relatively high speed, it is possible to perform an efficient impact operation. Furthermore, the vibration damping mechanism 177 is also driven at high speed corresponding to the second speed R2, which is faster than the first speed R1, so that the vibration damping effect against the relatively large vibrations that occur on the first housing 110 side when driven under load is maintained at a high level. In other words, vibrations can be effectively suppressed in accordance with the impact work, providing a good working environment.

[0104] (Anti-vibration handle action) In the load-driven state, the worker grasps the handle 130 and presses it downward in the first direction D1D to perform the impact work, but it is anticipated that vibrations will occur on the first housing 110 side due to the impact mechanism 180 or the impact work performed by the tip tool. In this case, the vibration causes relative movement between first housing 110 and second housing 120, and first elastic body 161 shown in FIG. 7 applies a biasing force between first housing 110 and second housing 120, thereby minimizing transmission of the vibration from first housing 110 to second housing 120. As described above, second housing 120 integrally includes handle 130 held by the operator, controller 260 that controls the drive of motor 210, various functional components 280 disposed in controller case 270, battery attachment section 123, and battery 150 attached to battery attachment section 123. This suppression of vibration transmission from first housing 110 to second housing 120 reduces the burden on the operator and thoroughly protects the controller 260, functional components 280, and battery attachment section 123, which are precision equipment.

[0105] In this embodiment, the movable stroke of first elastic body 161 is set to 10 mm (10 millimeters). If strong vibrations that use the entire movable stroke are input, buffer member 205 and stopper 204 described above will function to prevent adverse effects such as first housing 110 and second housing 120 hitting the bottom (see FIG. 7).

[0106] When the vibration isolation function is working under load driving condition, to be precise, (1) The first elastic body 161 exerts a biasing force, (2) The second elastic body 162, which is compressed by the pressure of the operator, also exerts a biasing force. Let it act, (3) Movable member biasing elastic body 293 compressed by the pressure of the worker (See Figure 20 etc.) also exerts a biasing force. These biasing forces (1), (2), and (3) act between the first housing 110 and the second housing 120. However, as described above, the elastic constant of the second elastic body 162 is set to a relatively small value, and furthermore, the elastic constant of the movable member biasing elastic body 293 is set to a minimum value that is sufficient to provide a biasing force for returning the movable member 292 to its initial position (see FIG. 19). Therefore, in this embodiment, the first elastic body 161, which can exert a strong elastic force, plays a major role in the vibration-damping function.

[0107] For example, if a single elastic body is used to detect pressure for switching from a no-load drive state to a loaded drive state and to provide vibration isolation between the first housing 110 and the second housing 120, increasing the elastic constant is effective for vibration isolation but results in the operator's required pressing force being too high. Conversely, decreasing the elastic constant allows the operator's required pressing force to be optimized but reduces the vibration isolation effect. In this embodiment, the "initial action" elastic body (i.e., second elastic body 162) for releasing the soft no-load and the elastic body for vibration damping (i.e., first elastic body 161) are provided separately and optimized for their respective uses, so such problems do not occur.

[0108] (Functions of the first sliding guide member 190 and the second sliding guide member 200) In the impact tool 100 according to this embodiment, (1) As shown in FIG. 7, the relative movement between the first housing 110 and the second housing 120 is guided by sliding at multiple points in the first direction D1 using the first sliding guide member 190 and the second sliding guide member 200, thereby ensuring stable operation. (2) As shown in FIG. 7, the first elastic body 161, which plays the main role of the vibration-damping mechanism, is positioned between the first sliding guide member 190 and the second sliding guide member 200 in the first direction D1, thereby providing a stable vibration-damping effect. (3) As shown in FIGS. 8 and 9, by arranging a plurality of first sliding guide members 190 and a plurality of second sliding guide members 200 around the first direction D1, more stable operation can be ensured. (4) For each component of the first sliding guide member 190 and the second sliding guide member 200, a metal pipe-shaped member 191 with excellent rigidity and a sheet metal sliding guide 203 are used, while the components paired with such high-rigidity members (such as the bifurcated member 192) are made of resin, thereby achieving both strength and light weight. (5) The first sliding guide member 190 and the second sliding guide member 200 not only provide sliding guidance, but also the stopper 204 determines the maximum movable distance of the relative movement, and furthermore, the buffer member 205 continuously buffers the relative movement from a state in which the relative movement has occurred a predetermined distance less than the maximum movable distance to the maximum movable distance, thereby constructing a rational vibration-proof structure. In addition, the stopper 204 and the buffer member 205 can be arranged in at least one of the first sliding guide 190 and the second sliding guide 200, or arranged separately (independently) from the first sliding guide 190 and the second sliding guide 200.

[0109] (Characteristics related to battery attachment, etc.) As described above, in the impact tool 100 according to this embodiment, as shown in Figures 4 to 7, the output shaft 213, which is likely to be the largest in the motor 210, is disposed so as to extend in the third direction D3, which is the thickness direction of the impact tool 100. The large dimension portion of the motor 210 is allocated along the third direction D3, and instead, a large space is secured as the expansion space S, which is formed for arranging other functional components, along the second direction D2, which is the width direction of the impact tool 100. That is, as shown in Figures 1 and 4, a relatively large space for other functional components is secured in the side region 114 of the first housing 110 in the second direction D2. In this embodiment, this makes it possible to position the battery 150, which is relatively heavy, as close as possible to the center of gravity of the impact tool 100 (located on the central axis along the first direction D1) in the second direction D2, thereby significantly reducing the occurrence of unnecessary couple forces in the impact tool 100.

[0110] In addition, the battery mounting direction 156 is set to be along the third direction D3 (see Figure 3), so when mounting the battery 150 in the battery mounting section 123, the expansion space S can be used to perform the mounting work in a large space, improving workability. Furthermore, by setting the battery mounting direction 156 to be along the third direction D3, the battery mounting direction 156 can be made to intersect with the first direction D1, in which vibrations are likely to occur during striking work, and this can prevent problems such as unexpected external forces acting on the battery 150 due to vibrations, causing it to suddenly detach.

[0111] Furthermore, as shown in FIG. 1 etc., by setting a pair of battery attachment sections 123 in the area 130A directly below the handle 130, the operator can hold the handle 130 with one hand and use the other hand to attach the battery 150 on the opposite side, then switch the way the handle 130 is held, and while still holding the handle 130 with the other hand, attach the battery 150 on the opposite side, thereby improving the coordination between holding the handle 130 and attaching the battery 150.

[0112] (Characteristics of detection reliability, etc. in detection mechanism 290) In this embodiment, as shown in Figures 10 to 13, 18 to 20, etc., the detection mechanism 290 is configured to be attached as an assembly to the controller case 270, which is a component of the second housing 120, via a detection mechanism attachment portion 274. The detection mechanism 290 is a member for detecting the relative movement between the first housing 110 and the second housing 120. Therefore, while it is common for the components thereof to be distributed and provided in both the first housing 110 and the second housing 120, in this embodiment, the detection mechanism 290 is distributed to the second housing 120, and the duct cover 220, which is an existing component of the first housing 110, is made to function as the actuating medium for the movable member 292.

[0113] Therefore, each component of the detection mechanism 290 can be integrally arranged on the first housing 110 side as an assembly, which makes it possible to reduce the risk of malfunctions caused by assembly errors of each component, and ultimately, unreliable detection. Furthermore, as shown in Figures 19 and 20, by forming a clearance 290CL between the duct cover 220, which is the operating medium of the movable member 292, assembly errors between the first housing 110 and the second housing 120 can be absorbed, thereby reducing the risk of malfunction and therefore unreliable detection.

[0114] Furthermore, as described above, the detection mechanism 290 constitutes a mechanism for releasing the soft no-load state and switching to the load-driven state, but during the impact operation, there may be cases where the pressing force temporarily decreases due to accidental circumstances such as a change in the worker's gripping posture or a change in the orientation of the impact tool 100 (the tilt angle relative to the first direction D1). In such cases, it would be inconvenient to switch from the loaded drive state to the soft no-load state each time the pressing force decreases, so in this embodiment, even if the pressing force decreases in the loaded drive state, the system is set to maintain the loaded drive state without switching to the soft no-load state until a certain time has passed (for example, one second), which further improves convenience during impact work.

[0115] Furthermore, while it is generally conceivable to detect pressure based on, for example, changes in the load current of the motor, and then release the soft no-load and switch to a load-driven state, there is a concern that, particularly in the case of large hammers characterized by high output, the load current may vary depending on, for example, the material or type of the object being struck, making it impossible to accurately detect pressure. In this embodiment, a configuration is adopted in which pressure is detected using a mechanical detection mechanism, namely, the movable member 292 biased by the movable member biasing elastic body 293, thereby ensuring reliable detection.

[0116] (Characteristics of Controller Case 270) In the impact tool 100 according to this embodiment, a controller 260 for controlling the motor drive is held in a controller case 270, as shown in FIGS. The controller case 270 according to this embodiment has the following features, for example. (1) The configuration holds not only the controller 260 but also various functional components 280, which streamlines and simplifies the device configuration and assembly, contributing to a more compact overall configuration. (2) The frame 271 is the main body and has a lightweight and highly rigid structure. (3) By being disposed in the second housing 120, which is the vibration-isolating side, a seismic isolation structure is achieved against vibrations occurring in the first housing 110. (4) By arranging the wiring harness (wiring) for the motor 210 in the area directly above the motor 210, it is easy to route the wiring harness (wiring) for the motor 210. (5) By arranging the impact tool 100 on the center line in the first direction D1, the wire harness (wiring) can be arranged symmetrically in both the second direction (width direction) D2 and the third direction (thickness direction) D3, which simplifies design and assembly. (6) As described above, in this embodiment, a brushless motor that can be easily miniaturized while maintaining high output is used as motor 210, and its output shaft 213 extends along third direction D3, forming expansion space S in side region 114. However, by arranging controller case 270 in the region directly above motor 210, the expansion space S can be easily used for arranging a wire harness, etc., enabling highly efficient use of the internal space.

[0117] (Cooling characteristics for motors, controllers, etc.) In the impact tool 100 according to this embodiment, the cooling air supply route to the components requiring cooling is, as described above, via the axial flow action of the cooling fan 214 of the motor 210, "air is taken in from the cooling air intake port 127" - "air flows through the inside of the head case 121" - "cools the controller 260" - "first end 232 of the duct hose 231" - "inside the duct hose 231" - "second end 233 of the duct hose 231" - "duct cover 220" - "inside the motor housing 215", thereby cooling the controller 260 and the motor 210 in that order. Furthermore, the cooling air that has cooled the motor 210 passes through the "upper drive mechanism accommodating section 111" and the "lower drive mechanism accommodating section 112" in the first housing 110, cools the motion conversion mechanism 170 and (part of) the impact mechanism 180, and is then discharged to the outside of the impact tool 100. For convenience, detailed illustration of the cooling air passages and the like downstream of the motor 210 is omitted.

[0118] Furthermore, the impact tool 100 according to this embodiment has the following characteristics regarding the cooling performance of the components. (1) Duct hose 231 is arranged in a connected state between first housing 110 and second housing 120 using a member that applies a biasing force toward the contraction side so that when duct hose 231 is extended from a predetermined initial state, it returns to the initial state. This causes duct hose 231 to be constantly biased toward the contraction side so that it returns to its initial state. Therefore, even when first housing 110 and second housing 120 move relative to each other, duct hose 231 does not slacken and come into contact with other components, causing wear, and is less likely to develop excessive tension or twisting, allowing cooling air to be effectively transported between components that move relative to each other.

[0119] (2) As shown in Figures 11, 16, and 17, the cross sections of first end 232 and second end 233 intersect with each other. This makes it easier to avoid twisting of duct hose 231 and unnecessary tension being applied when first housing 110 and second housing 120 move relative to each other, as in (1) above.

[0120] (3) As shown in Figure 16, first end 232 and second end 233 of duct hose 231 are directly fitted and attached to duct member attachment portion 272 of controller case 270 and duct member attachment portion 225 of the duct cover, respectively. In other words, by adopting a structure without an adapter, the device configuration can be simplified.

[0121] (4) As shown in FIG. 16, the first end 232 of the duct hose 231 is located in the upper area adjacent to the cooling fan 214 of the motor 210. This prevents the duct hose 231 from being unnecessarily long, and also makes it easier to avoid problems such as the duct hose being too short and causing unnecessary tension.

[0122] (5) As shown in Fig. 16, cooling air intake port 127A is provided at least at the end of controller case 270 opposite duct member mounting portion 272. Furthermore, in this embodiment, cooling air intake port 127 is provided over the entire top surface of head case 121. This allows the cooling air drawn into impact tool 100 to cool controller 260 over the entire surface, improving cooling efficiency.

[0123] (6) As shown in Figure 11, the duct hose 231 is placed in a state in which the curved shape of the approximate center is maintained by the duct portion guide rib 116 of the motor housing 215. As a result, even when the first housing 110 and the second housing 120 move relative to each other, the mounting shape (approximately L-shaped) of the duct hose 231 is maintained, making it easier to avoid twisting of the duct hose 231 and application of unnecessary tension.

[0124] As described above, according to this embodiment, a construction technique is provided that contributes to rationalizing the arrangement of components and operability of the impact tool 100, which normally performs impact work while facing downward due to its own weight. [Explanation of symbols]

[0125] 100: Impact tools 110: First housing (main body) 111: Upper drive mechanism housing 112: Lower drive mechanism housing 113: Tip area 114: Lateral area 115: Motor housing 116: Duct guide rib 120: Second housing (main body) 120A: First elastic body mounting seat 120B: Second elastic body mounting seat 120C: Pressure seat 121: Head Case 122: Handle attachment part 123: Battery compartment 124: Slide Guide 125: Power supply terminal 126: Buffer member contact seat 127: Cooling air intake 128: Battery protector 129;LED light 130: Handle 131: First handle part (handle R) 132: First handle base 133: First handle gripping portion 134: Free end area 135: Trigger 136: Electric switch 141: Second handle (handle L) 142: Second handle base 143: Second handle gripping portion 144: Free end area 130A: Area directly below the handle 150: Battery 151: Front of battery 152: Top of battery 153: Bottom of battery 154: Rear of battery 155: Unlocking section 156: Battery installation direction 161: First elastic body 162: Second elastic body 170:Movement conversion mechanism 171: First intermediate shaft 172: Second intermediate shaft 173: Crank mechanism 174: Cylinder 174A: Ventilation hole 175: Piston 176:Air chamber 177: Vibration control mechanism 178: Counterweight 180: Impact mechanism 181: Striker 182: Impact bolt 190: First sliding guide member (handle-proximal sliding guide member) 191: Pipe-shaped member (first housing side component) 192: Bifurcated member (second housing side component) 190CL: Clearance 200: Second sliding guide member (handle-separating side sliding guide member) 201: Convex member 202: Concave member 203: Sheet metal sliding guide 204: Stopper 205: Cushioning material 210: Motor 211: Stator 212:Rotor 213: Output shaft 214: Cooling fan 215: Motor housing 220: Duct cover 221:Interior space 222: Motor mounting seat 223: Flange 224: Cooling air guideway 225: Duct component mounting part 230: Duct parts 231: Duct hose 232: First end 233:Second end 240: Tool holder 250: Retainer 260: Controller 261: Heat dissipation fin 270: Controller case 271: Frame 272: Duct component mounting part 273: Head case mounting part 274: Detection mechanism mounting part 275: Main power switch mounting part 276: Communication unit mounting part 277: Wire harness insertion opening 278: Second elastic body mounting part 280: Functional materials 281: Main power switch 282:Communication unit 290:Detection mechanism 291: Assembly base 292: Movable parts 293: Movable member biasing elastic body 294: Sensor 290CL: Clearance D1: 1st direction (long axis direction) D1D: 1st direction downward D1U: 1st direction upward D2: Second direction (width direction) D3: Third direction (thickness direction) AX: Long axis HL: Virtual line MS: Initial distance S: Expansion space

Claims

1. An impact tool comprising: an elongated main body portion provided with a tool holder at a tip region; and a pair of handles extending in a second direction, where a longitudinal direction of the main body portion is defined as a first direction and a width direction intersecting the first direction is defined as a second direction, wherein an operator holds the pair of handles in the left and right hands, respectively, and performs impact work via a tool bit detachably attached to the tool holder in a state in which the handles are hanging down by their own weight, a drive mechanism that drives the tool bit in the first direction; a motor having a motor output shaft for driving the drive mechanism; a first housing and a second housing which are components of the main body; an elastic body interposed between the first housing and the second housing, the drive mechanism and the motor are provided in the first housing, The pair of handles are provided on the second housing, the second housing is configured to be movable relative to the first housing together with the pair of handles via the elastic body, a plurality of sliding guide members for guiding relative movement between the first housing and the second housing are provided at a plurality of locations in the first direction, The impact tool is characterized in that the multiple sliding guide members include a handle-proximal side sliding guide member that is positioned close to the handles in the first direction so that its position in the first direction at least partially overlaps with the pair of handles, and a handle-away side sliding guide member that is positioned farther away from the handles than the handle-proximal side sliding guide member.

2. The impact tool according to claim 1, When the first direction is defined as a direction from the handles to the tool holder as a downward direction and a direction from the tool holder to the handles as an upward direction, at least a portion of the first housing is located above the pair of handles, The impact tool, wherein the second housing covers a portion of the first housing that is positioned above the pair of handles.

3. The impact tool according to claim 1 or 2, The impact tool, wherein at least a portion of the sliding guide member is located between each of the pair of handles and the first housing in the second direction.

4. 4. The impact tool according to claim 1, wherein the elastic body is disposed between the plurality of sliding guide members in the first direction.

5. The impact tool according to claim 1 , wherein the sliding guide members are further arranged at a plurality of positions around the first direction.

6. 6. The impact tool according to claim 1, wherein the handle-proximal-side sliding guide member has a metal component provided on one of the first housing and the second housing, and a resin component provided on the other housing and sliding relative to the metal component.

7. 7. The impact tool according to claim 6, wherein the metal component is provided in the first housing and configured as a pipe-shaped member having a circumferential direction around the first direction, and the resin component is provided in the second housing and configured as a bifurcated member connected to the metal component, which is the pipe-shaped member.

8. 8. The impact tool according to claim 6, wherein the handle-separating-side sliding guide member has a convex member provided on one of the first housing and the second housing and extending in the first direction, and a concave member provided on the other housing and fitting into the convex member.

9. 9. The impact tool according to claim 8, wherein a sliding guide made of sheet metal is interposed between at least one of the convex member and the concave member.

10. 10. The impact tool according to claim 1, further comprising a stopper that defines a maximum distance of relative movement of the second housing with respect to the first housing in the first direction.

11. 11. The impact tool according to claim 10, further comprising a buffer member that buffers the relative movement of the second housing when the second housing moves relative to the first housing by a predetermined distance that is less than a maximum movable distance.

12. 12. An impact tool according to claim 1, wherein, when the elastic body is defined as a first elastic body, the impact tool further comprises, in addition to the first elastic body, a second elastic body as an initial movement elastic body interposed between the first housing and the second housing, and when the second housing moves relative to the first housing within a predetermined initial movement distance, the biasing force of the second elastic body acts.

13. 13. The impact tool according to claim 12, wherein when the second housing moves relative to the first housing beyond the initial movement distance, the biasing forces of both the first elastic body and the second elastic body act.

14. 14. The impact tool according to claim 13, wherein the second elastic body is provided above the first elastic body when the direction from the handle to the tool holder is defined as a downward direction and the direction from the tool holder to the handle is defined as an upward direction, in the first direction.

15. 15. The impact tool according to claim 1, wherein the second housing is provided with a battery mounting portion into which a battery for supplying power to the motor can be mounted, and a battery protector that protects at least a portion of the outer casing of the battery from external forces when the battery is mounted in the battery mounting portion.

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