WO2012144568A1 - Impact tool - Google Patents

Abstract

[Problem] To provide an impact tool, the body of which is shortened in the direction of the long axis of a tool bit. [Solution] An impact tool in which a tool bit (119) moves linearly in at least the direction of the long axis thereof, thereby working a workpiece in a prescribed manner. Said impact tool has the following: a tool holder (137) that holds the tool bit (119) so as to allow relative movement in the direction of the long axis thereof; an impactor (143) that moves linearly in the direction of the long axis of the tool bit (119) and applies an impact force thereto; and an impact cylinder (141) that is provided with an air chamber (141a) that causes compressed air to act upon the impactor (143), contains the impactor (143) so as to allow relative movement, and is coupled to the tool holder (137). The tool holder (137) and the impact cylinder (141) extend in the direction of the long axis of the tool bit (119), and the length of the body of the tool in the direction of the long axis of the tool bit (119) is determined by the tool holder (137) and the impact cylinder (141).

Description

Impact tool

The present invention relates to an impact tool that performs a predetermined machining operation on a workpiece by a tool bit moving linearly at least in the long axis direction.

U.S. Pat. No. 4,751,970 discloses an angular attachment that is attached to the tip of a hammer drill and can transmit rotational and linear motion on the hammer drill body side to tool bits oriented in different directions at the output of the attachment. is doing. The angle attachment is set so that the output portion of the tool bit intersects the output portion of the hammer drill main body at an angle of 90 degrees. For this reason, for example, when drilling the inner wall surface of a U-shaped groove (made of concrete) as a drainage groove, the total length of the hammer drill body in the bit long axis direction is longer than the inner dimension of the groove in a normal hammer drill. When the hammer drill cannot be put inside the U-shaped groove, it is possible to perform a drilling operation on the inner wall surface of the U-shaped groove using the angle attachment.

The above prior art is configured to reduce the length of the tool bit in the long axis direction by attaching an angle attachment to the output portion of the hammer drill, and transmission of rotational motion and linear motion to the tool bit is not efficient. It does not realize a reduction in the tool body length in the tool bit long axis direction.

US Pat. No. 4,751,970

The present invention has been made in view of the above, and an object of the present invention is to provide an impact tool in which the tool body length in the long axis direction of the tool bit is shortened.

In order to solve the above-described problems, according to a preferred embodiment of the present invention, an impact tool that performs a predetermined machining operation on a workpiece by configuring a tool bit to move linearly at least in the long axis direction is configured. The striking tool is connected to a tool holder that holds the tool bit so as to be relatively movable in the long axis direction, a striking element that linearly moves in the long axis direction of the tool bit and applies a striking force to the tool bit, and a tool holder. The driving element is housed so as to be relatively movable, and has a striking cylinder provided with an air chamber that applies a compressive force to the striking element, and a tool main body that houses the tool holder and the striking cylinder. The tool holder and the impact cylinder are both extended in the longitudinal direction of the tool bit, and the length of the tool body in the longitudinal direction of the tool bit is defined by the tool holder and the impact cylinder. Yes.

According to a preferred form of the impact tool according to the present invention, the length dimension of the tool body in the long axis direction of the tool bit is defined by the tool holder and the impact cylinder. As a result, the length of the tool bit in the long axis direction of the tool bit can be shortened compared to the conventional impact tool defined by not only the tool holder and impact cylinder but also the mechanism that fluctuates the air chamber pressure. And can be suitably used for processing operations in a limited space. Further, unlike the conventional angle attachment, the striking force of the striker can be transmitted linearly to the tool bit, so that power can be transmitted without waste.

According to a further aspect of the impact tool according to the present invention, the impact tool further includes a compressed air supply cylinder for supplying compressed air to the air chamber of the cylinder. The compressed air supply cylinder extends in a direction different from the extending direction of the striking cylinder. Here, “extending in different directions” means that the compressed air supply cylinder extends in a direction perpendicular to the extending direction of the striking cylinder or in an angled direction. It corresponds to.

In the case of an impact tool, a tool holder for holding the tool bit, an impact chamber for applying impact force to the tool bit, and an air chamber for allowing compressed air to act on the impact bit are provided in the major axis direction of the impact bit. In general, a striking cylinder, a piston for generating compressed air in an air chamber, and a driving mechanism thereof are arranged in series in the longitudinal direction of the tool bit. According to this aspect, the compressed air supply cylinder that supplies compressed air to the air chamber of the striking cylinder is configured to extend in a direction different from the extending direction of the striking cylinder. The length dimension of the impact tool in the axial direction can be shortened.

According to the further form of the impact tool according to the present invention, the impact tool has a handgrip connected to the tool body and gripped by the operator to operate the impact tool, and the width direction of the handgrip is the extending direction of the impact cylinder. It is set to become. Note that the “handgrip width direction” here intersects with the extending direction of the grip part, for example, in the case of a handgrip having a region in which the grip part gripped with a finger extends linearly. This is the direction.
According to this embodiment, since the width direction of the handgrip is set to be the extending direction of the hitting cylinder, when the handgrip is gripped with a finger, the extending direction of the arm (forearm) is the hitting cylinder. Extending direction, that is, a direction crossing the long axis direction of the tool bit. In other words, because the direction of the arm intersects the long axis direction of the tool bit, for example, when working on the inner wall surface of the U-shaped groove (made of concrete) as a drainage groove, hold the handgrip so that the arm does not get in the way. Can carry out machining operations.

According to the further form of the impact tool which concerns on this invention, it sets so that the major axis direction of a tool bit, the extension direction of a compressed air supply cylinder, and the extension direction of a handgrip may all cross | intersect.
According to this aspect, by using the above-described configuration, it is possible to provide an impact tool that realizes an overall compact arrangement.

According to the further form of the impact tool which concerns on this invention, it further has a motion conversion mechanism which generates compressed air in the air chamber of the impact cylinder by converting rotational motion into linear motion. The rotation shaft of the motion conversion mechanism is arranged in parallel with the striking cylinder in a predetermined region in the extending direction of the striking cylinder. In this case, it is preferable that the rotating shaft of the motion conversion mechanism intersects the extending direction of the striking cylinder.
According to this aspect, the motion conversion mechanism that generates compressed air in the air chamber is arranged in parallel to the striking cylinder. For this reason, in the long axis direction of the tool bit, the length dimension of the hitting tool in the long axis direction of the tool bit is compared with the conventional case where the motion conversion mechanism is disposed at a position deviated from the long axis direction region of the hitting cylinder. It can be shortened.

According to the further form of the striking tool according to the present invention, the striking tool has a hand grip to be operated by the operator, and the extending direction of the striking cylinder and the extending direction of the hand grip are set parallel to each other. ing.
According to this aspect, since the extending direction of the hand grip is matched with the extending direction of the striking cylinder, when the hand grip is gripped with a finger, the extending direction of the arm (forearm) is the extending direction of the striking cylinder. The current direction, that is, the direction intersecting the long axis direction of the tool bit. In other words, since the direction of the arm intersects the long axis direction of the tool bit, for example, when working on the inner wall surface of the U-shaped groove, it is possible to carry out the machining work by grasping the hand grip in such a way that the arm does not get in the way. it can.

According to the present invention, an impact tool in which the tool body length in the long axis direction of the tool bit is shortened is provided.

It is a plane sectional view showing the whole hammer drill composition concerning a 1st embodiment of the present invention. FIG. 2 is a sectional view taken along line AA in FIG. 1. FIG. 3 is a sectional view taken along line BB in FIG. It is sectional drawing which shows the modification regarding gear arrangement | positioning. It is sectional drawing which shows the modification regarding supply of compressed air. FIG. 6 is a cross-sectional view taken along the line CC of FIG. It is sectional drawing which shows the further modification regarding supply of compressed air. FIG. 8 is a sectional view taken along line DD of FIG. It is sectional drawing which shows the further modification regarding supply of compressed air. It is sectional drawing which shows the whole structure of the hammer drill which concerns on the 2nd Embodiment of this invention. It is an expanded sectional view showing a motion conversion mechanism, and shows the state where the piston was moved back. It is the figure which looked at the motion conversion mechanism from the side. FIG. 13 is a cross-sectional view showing a cross-sectional shape of an impact cylinder cut along line FF in FIG. 12. It is sectional drawing which shows the modification of 2nd Embodiment. It is an expanded sectional view showing the motion conversion mechanism of the modification, and shows the state where the piston was moved backward.

(First embodiment of the present invention)
Hereinafter, a first embodiment of the present invention will be described in detail with reference to FIGS. This embodiment is described using an electric hammer drill as an example of a work tool. As shown in FIG. 1 and FIG. 2, the hammer drill 101 according to the present embodiment is generally viewed from the main body 103 that forms the outline of the hammer drill 101, and the long axis direction of the main body 103 (the left and right in FIG. 1). Direction) and a handgrip 109 as a main handle formed on the opposite side of the hammer bit 119 in the main body 103. It is configured as.

The hammer bit 119 is defined as a direction in which the major axis direction intersects the major axis direction (left and right direction in FIG. 1) of the main body 103, and the hammer bit 119 is moved in the major axis direction by a hollow tool holder 137 as a tool holding member. It is held so as to be capable of relative linear movement. Therefore, the tool holder 137 extends in the direction intersecting the major axis direction of the main body 103, that is, in the width direction of the main body 103. The main body corresponds to the “tool main body” in the present invention, and the hammer bit 119 corresponds to the “tool bit” in the present invention.

The main body 103 accommodates the outer housing 105 including a motor housing that accommodates the drive motor 111, the motion conversion mechanism 113, the compression device 114, the striking element 115, and the power transmission mechanism 117, and covers most of the outer housing 105. A gear housing 107 as an inner housing is mainly used.

The hand grip 109 has a grip portion 109 a gripped by an operator extending in the vertical direction intersecting the major axis direction of the main body portion 103, and upper and lower ends of the grip portion 109 a are connected to the outer housing 105. It is configured as a D-shaped handle. The hammer bit 119 extends in the horizontal direction in which the major axis direction intersects the major axis direction of the main body 103 and the extending direction of the hand grip 109.

Further, as shown in FIG. 1, the hammer drill 101 is provided with a side grip 110 as a sub handle separately from the hand grip 109. The side grip 110 is a rod-like member that extends in a direction intersecting the major axis direction of the hammer bit 119, and one end in the major axis direction is removed from the outside of the substantially cylindrical barrel portion 107 a that houses the tool holder 137. A fixed position in the circumferential direction around the major axis of the hammer bit 119 is attached so as to be adjustable. The barrel portion 107a is provided as a region exposed through the side surface of the outer housing 105 of the gear housing 107.

As shown in FIG. 2, the drive motor 111 is arranged so that the rotation axis is in the vertical direction (vertical direction in FIG. 2) that is substantially orthogonal to the long axis direction of the main body 103. The rotational power of the drive motor 111 is converted into a linear motion via the motion conversion mechanism 113 and then drives the compression device 114. The compressed air generated by the compression device 114 is supplied to the striking cylinder 141 to drive the striking element 115, and the hammer bit 119 passes through the striking element 115 in the long axis direction (vertical direction in FIG. 1). Generates an impact force.

The rotation output of the drive motor 111 is transmitted to the hammer bit 119 via the tool holder 137 after the rotation speed is reduced by the power transmission mechanism 117, and the hammer bit 119 is rotated in the circumferential direction. The drive motor 111 is energized and driven by a pulling operation of a trigger 147 as an operation member disposed on the handgrip 109, and the rotation direction is switched by a sliding operation of a forward / reverse switching switch 149 disposed near the trigger 147. It is possible. The slide operation direction of the forward / reverse switching switch 149 can be arbitrarily set.

As shown in FIG. 2, the motion conversion mechanism 113 is formed on the motor shaft 111a of the drive motor 111, and is driven to rotate in a horizontal plane. The driven gear 123 is engaged with and engaged with the drive gear 121. A crankshaft 125 that rotates integrally with the driven gear 123, a crankpin 126 that is eccentrically provided on the crankshaft 125, a crank arm 127 that is connected loosely to the crankpin 126, and a connecting shaft 128 connected to the crankarm 127. The main component is a piston 129 as a driver attached. The motor shaft 111a and the crankshaft 125 are arranged in parallel to each other and side by side. The crank shaft 125, the crank pin 126, the crank arm 127, and the piston 129 constitute a crank mechanism.

The piston 129 is slidably disposed on the bore inner wall of the air compression cylinder 131, and the piston 129 and the air compression cylinder 131 constitute a compression device 114. The air compression cylinder 131 corresponds to the “compressed air supply cylinder” in the present invention. The air compression cylinder 131 has a compression chamber 131 a partitioned by the gear housing 107 and the piston 129. The piston 129 generates compressed air by reducing (reducing) the volume of the compression chamber 131 a, and the generated compressed air passes through the air passage 133 formed in the gear housing 107 to the air chamber 141 a of the striking cylinder 141. Supply. The air compression cylinder 131 extends in the same direction as the major axis direction of the main body 103, and intersects the major axis direction of the hammer bit 119 and the extension direction of the hand grip 109. That is, the major axis direction of the hammer bit 119, the extending direction of the air compression cylinder 131, and the extending direction of the handgrip 109 are all set to intersect.

The striking element 115 is striker 143 as a striking element slidably disposed on the bore inner wall of the striking cylinder 141, and is slidably disposed on the tool holder 137, and the kinetic energy of the striker 143 is transferred to the hammer bit 119. And an impact bolt 145 serving as an intermediate for transmitting to the main body. The striking cylinder 141 has an air chamber 141 a that extends in the longitudinal direction of the hammer bit 119 and is partitioned by a striker 143 and an inner wall surface 107 b of the gear housing 107 facing the striker 143. When the compressed air generated by moving the piston 129 in the direction of decreasing the volume of the compression chamber 131a (left side in FIGS. 1 and 2) is supplied to the air chamber 141a of the striking cylinder 141, the striker 143 is moved forward by the compressed air to collide (hit) the impact bolt 145, and transmits the striking force to the hammer bit 119 via the impact bolt 145.

When the piston 129 is moved in the direction of increasing the volume of the compression chamber 131a, the pressure in the air chamber 141a of the striking cylinder 141 becomes negative, and the striker 143 is sucked by the negative pressure and moved toward the inner wall surface 107b. To return to the retracted position. In order to prevent the striker 143 from colliding with the inner wall surface 107b facing the striker 143 during the returning operation, and to ensure a predetermined gap between the striker 143 and the inner wall surface 107b, A buffer spring 144 is attached.

In the present embodiment, one end of the air passage 133 is opened at the bottom of the compression chamber 131a of the air compression cylinder 131, and the other end of the air passage 133 faces the head portion of the air chamber 141a of the striking linder 141 (opposing the striker 143). The compressed air is fed in the major axis direction of the striking cylinder 141. In the present embodiment, the impact cylinder 141 is formed by an extended portion of the tool holder 137 in the long axis direction. However, the tool holder 137 and the striking cylinder 141 may be changed to a configuration in which the tool holder 137 and the striking cylinder 141 are separately formed and coupled.

The striking cylinder 141 and therefore the tool holder 137 are rotated from the drive motor 111 via the power transmission mechanism 117. As shown in FIG. 2, the power transmission mechanism 117 includes a first intermediate gear 151 that meshes and engages with the drive gear 121 driven by the drive motor 111, a second intermediate gear 153 that meshes and engages with the first intermediate gear 151, A small bevel gear 155 that rotates integrally with the second intermediate gear 153 and a large bevel gear 157 that meshes with and engages with the small bevel gear 155 are mainly configured. The first intermediate shaft 152 provided with the first intermediate gear 151, the second intermediate gear 153, and the second intermediate shaft 154 provided with the small bevel gear 155 are arranged in parallel with the motor shaft 111a of the drive motor 111, respectively. The gear housing 107 is rotatably supported. A large bevel gear 157 whose rotational axis is orthogonal to the small bevel gear 155 is attached to the outer periphery of the impact cylinder 141 so as to be relatively rotatable, and is connected to the impact cylinder 141 via a torque limiter 159 (see FIG. 1). .

The torque limiter 159 has clutch teeth 159a that mesh with the clutch teeth 157a of the large bevel gear 157, and is always attached in a direction in which the clutch teeth 157a and 159a mesh with each other by an urging spring (compression coil spring) 161. It is energized. The torque limiter 159 moves away from the large bevel gear 157 against the urging force of the urging spring 161 when the repulsive torque acting on the hammer bit 119 reaches a set value, and both clutch teeth The meshing engagement of 157a and 159a is released, and the rotation transmission from the large bevel gear 157 to the striking cylinder 141 is cut off. The motor shaft 111a, the crankshaft 125, and the first and second intermediate shafts 152 and 154 are arranged on the same straight line P in the major axis direction of the main body 103 as shown in FIG.

The hammer drill according to the present embodiment is configured as described above. Therefore, when the drive motor 111 is energized and driven by pulling the trigger 147, the motion conversion mechanism 113 is driven. Therefore, the piston 129 is slid linearly in the air compression cylinder 131 to compress the air in the compression chamber 131a, and the compressed air passes through the air passage 133 to the air chamber of the striking cylinder 141. 141a. As a result, the striker 143 moves forward in the impact cylinder 141 and collides with the impact bolt 145, thereby transmitting the kinetic energy to the hammer bit 119.

On the other hand, the rotational output of the drive motor 111 is transmitted to the striking cylinder 141 via the power transmission mechanism 117. Therefore, the hammering cylinder 141, the tool holder 137, and the hammer bit 119 held by the tool holder 137 are integrally rotated. Thus, the hammer bit 119 performs a linear motion in the axial direction and a rotational motion in the circumferential direction, thereby performing a drilling operation on the workpiece.

In the present embodiment, in the hammer drill 101 configured to drive the striker 143 by compressed air in the air chamber 141a of the impact cylinder 141, an air compression cylinder 131 is provided separately from the impact cylinder 141. The striker 143 is driven by supplying the compressed air generated in the compression chamber 131 a of the air compression cylinder 131 to the air chamber 141 a of the striking cylinder 141. The air compression cylinder 131 is disposed so as to extend in a direction intersecting with the extending direction of the striking cylinder 141. As a result, the striking direction length of the tool body 103 with respect to the longitudinal length of the hammer bit 119 accommodates the tool holder 137 that holds the hammer bit 119 and the striker 143 that imparts striking force to the hammer bit 119. The striking cylinder 141 is defined by the extension length of the striking cylinder 141 provided with an air chamber 141a that allows compressed air to act on the striker 143.

Therefore, according to the present embodiment, the hammer bit 119 is hit as compared with the conventional hammer drill configured to drive the striker 143 by the pressure fluctuation of the air chamber 131a due to the linear movement of the piston 129 in the hit cylinder 141. The length of the tool body 103 with respect to the direction can be shortened. For this reason, for example, in the case where a drilling operation is performed on the inner wall surface of a U-shaped groove (made of concrete) as a drainage groove, the tool body 101 is placed in a U shape so that the major axis direction of the hammer bit 119 is the groove width direction. The hole can be drilled by inserting it into the groove.

Also, the hammer drill 101 according to the present embodiment is configured such that the striking force of the striker 143 is transmitted linearly to the hammer bit 119. For this reason, compared with the structure which attaches an angle attachment to the front-end | tip of a hammer drill and transmits the strike force of a striker to a hammer bit, the strike force of the striker 143 can be transmitted to the hammer bit 119 without a loss.

During the drilling operation, the operator operates the hammer drill 101 by grasping the hand grip 109 as the main handle and the side grip 110 as the sub handle. In the present embodiment, the width direction of the hand grip 109, that is, the direction intersecting with the extending direction of the grip portion 109a is set to be the extending direction of the striking cylinder 141. For this reason, when the grip part 109a of the handgrip 109 is gripped by a finger, the extending direction of the arm (forearm) is in a direction intersecting with the extending direction of the striking cylinder 141, for example, on the inner wall surface of the U-shaped groove It is possible to perform the machining operation by holding the hand grip 109 in such a way that the arm does not get in the way when the machining operation is performed.

Further, in the present embodiment, assuming that the side grip 110 is difficult to use or does not include the side grip 110, the end region on the rear side in the striking direction of the outer housing 105 is pressed by the entire palm. It is set as a possible subgrip 163 (see FIG. 1). Thus, the operator can perform the drilling operation while holding the hand grip 109 with one hand and pressing the sub grip 163 in the striking direction with the other hand.

Incidentally, the size (outer diameter) of the drive motor 111 dominates the outer dimension of the motor housing portion 105 a that covers the drive motor 111 in the outer housing 105. In the present embodiment, as shown in FIG. 3, the drive gear 121, the driven gear 123 of the motion conversion mechanism 113, and the first intermediate gear 151 of the power transmission mechanism 117 are the second intermediate gear 153 (small bevel gear 155). It is arranged in series on a straight line P extending in the radial direction through the center and parallel to the rearward side surface 105b (the major axis direction of the piston 129) of the outer housing 105. Such an arrangement of the gears prevents the motor housing portion 105a of the outer housing 105 from protruding beyond the rear side surface 105b in the striking direction of the outer housing 105 if the size (outer diameter) of the drive motor 111 is small. Therefore, as a result, there is no problem in shortening the length of the tool main body 103 in the striking direction.

However, if the size (outer diameter) of the drive motor 111 is large, the motor housing portion 105a of the drive motor 111 protrudes rearward from the rear side surface 105b of the outer housing 105 in the striking direction, and the tool body 103 is long in the striking direction. This will hinder the shortening of length. Therefore, a modification shown in FIG. 4 is provided to prevent the motor housing portion 105a from protruding when the size (outer diameter) of the drive motor 111 is large.

In the modification, the drive gear 121, the driven gear 123 of the motion conversion mechanism 113, and the first intermediate gear 151 of the power transmission mechanism 117 extend in the radial direction through the center of the second intermediate gear 153 (small bevel gear 155). The motor housing portion 105a is disposed on a straight line P1 that is offset by a predetermined amount E in the striking direction with respect to the straight line P parallel to the striking direction rear side surface 105b of the outer housing 105. It is possible to eliminate protruding backwards.

Next, a modified example regarding the compressed air supply passage in the present embodiment will be described with reference to FIGS. In the embodiment described above, the compressed air is supplied to the air chamber 141a from the head side of the impact cylinder 141. However, in this modification, the air passage 133 for supplying the compressed air is provided on the side wall of the impact cylinder 141. The compressed air is supplied to the radial direction of the air chamber 141a from the side intersecting the long axis direction of the impact cylinder 141. For this reason, compared with the structure supplied from the head side, it is possible to further reduce the striking direction length of the tool body 103 corresponding to the dimension for setting the air passage 133.

Also, in this modification, the air passage 133 is directly connected to the striking cylinder 141, and therefore cannot be rotated. Therefore, the impact cylinder 141 is formed separately from the tool holder 137 and is fixed to the gear housing 107. On the other hand, the tool holder 137 has an extension portion 137a that is externally fitted to the striking cylinder 141 so as to be relatively rotatable, and the large bevel gear 157 is attached to the extension portion 137a so as to rotate integrally. Accordingly, the rotation output of the drive motor 111 can be transmitted to the tool holder 137 holding the hammer bit 119 while having a structure in which the striking cylinder 141 is fixed.

Next, a further modification regarding the compressed air supply passage will be described with reference to FIGS. In this modification, a ring-shaped member 165 that is attached to the outer periphery of the impact cylinder 141 so as to be relatively rotatable and has an annular groove 165 a extending in the circumferential direction on the inner peripheral surface, and a compression chamber 131 a of the air compression cylinder 131. And the connecting pipe 167 that communicates with the annular groove 165 a of the ring-shaped member 165 constitutes an air passage 133. Further, the annular groove 165a communicates with the air chamber 141a via a plurality of vent holes 169 in the circumferential direction formed in the wall portion of the impact cylinder 141. Therefore, according to this modification, in the configuration (integrated structure) in which the impact cylinder 141 rotates together with the tool holder 137, the compressed air of the air compression cylinder 131 is laterally intersected with the major axis direction of the impact cylinder 141. It becomes possible to supply to the air chamber 141a. For this reason, the impact direction length of the tool main body 103 can be further shortened similarly to the modification shown in FIG.

Next, a further modification regarding the compressed air supply passage will be described with reference to FIG. In this modification, the air compression cylinder 131 is disposed in an inclined shape in which the major axis direction is inclined at a predetermined angle with respect to the major axis direction of the main body 103 and is provided so as to protrude from the bottom of the compression chamber 131a. The distal end of the tubular portion 171 is connected to the gear housing 107. On the other hand, an internal passage 173 communicating with the air chamber 141a is formed by making the head side end portion of the striking cylinder 141 face the inner wall surface of the gear housing 107 with a predetermined gap, and this internal passage 173 is formed in the gear housing. 107 is configured to communicate with the compression chamber 131 a of the air compression cylinder 131 via a tubular portion 171 connected to the air pressure chamber 107.

According to this modified example, as in the modified examples shown in FIGS. 7 and 8, in the configuration in which the impact cylinder 141 rotates together with the tool holder 137 (integrated structure), the compressed air of the air compression cylinder 131 is used as the impact cylinder 141. It is possible to supply the air chamber 141a from the side intersecting the major axis direction of the tool, and the length of the tool body 103 in the striking direction can be further shortened.

(Second embodiment of the present invention)
Next, a second embodiment of the present invention will be described with reference to FIGS. In addition, about 2nd Embodiment, it demonstrates centering on difference so that duplication description with 1st Embodiment may be avoided, and it attaches | subjects and demonstrates the same code | symbol about the same component. As shown in the figure, in this embodiment, a piston 129 that performs linear motion among the constituent members constituting the motion conversion mechanism 113 is slidably disposed in the bore of the striking cylinder 141. Therefore, the striker 143 is driven via the pressure fluctuation of the air chamber 141a accompanying the sliding movement of the piston 129, and collides (hits) with the impact bolt 145 slidably disposed on the tool holder 137, and the impact bolt. The striking force is transmitted to the hammer bit 119 via 145. In other words, the air compression cylinder in the first embodiment is omitted. The striking cylinder 141 has a structure divided with respect to the tool holder 137, and is fitted to the tool holder 137 so as to be relatively rotatable on the same axis and is fixed to the gear housing 107.

In the drive motor 111, the motor shaft 111 a extends in the same direction as the major axis direction of the main body 103, and thus intersects with the major axis direction of the hammer bit 119 (extension direction of the tool holder 137 and the hitting cylinder 141). Is arranged. In the present embodiment, the motion conversion mechanism 113 that converts the rotational output of the drive motor 111 into a linear motion is arranged in parallel with the striking cylinder 141 in a predetermined region on the long axis direction of the striking cylinder 141. ing. In other words, the motion conversion mechanism 113 is disposed so as to overlap with each other when viewed from the direction intersecting the major axis direction of the hammer bit 119 (the major axis direction of the main body 103) with respect to the impact cylinder 141. In addition, the rotation axis of the crankshaft 125 intersects the extending direction of the striking cylinder 141. The crankshaft 125 corresponds to the “rotary shaft” in claim 5 of the present invention.

In the motion conversion mechanism 113, the crank arm 181 is formed of a substantially U-shaped member. An escape groove 183 for disposing the crank arm 181 is formed on the peripheral wall (side wall) of the striking cylinder 141. A U-shaped bottom region 181a (see a two-dot chain line in FIG. 12) of the crank arm 181 is formed in a circular cross section. The crank arm 181 has one end connected to the connecting shaft 128 of the piston 129 and the other end connected to the crank pin 126 in a state where the bottom region 181 a is escaped and disposed in the groove 183. The escape groove 183 is set to have a lateral width and an axial length that allow the crank arm 181 to move in the long axis direction of the striking cylinder 141 while performing a swinging motion with the connecting shaft 128 as a fulcrum. ing.

As described above, in the present embodiment, the crank arm 181 is formed in a U shape, and the crank arm 181 moves in the escape groove 183 formed on the peripheral wall of the striking cylinder 141. The motion conversion mechanism 113 can be arranged in parallel in the extending direction region (long-axis direction region) of the striking cylinder 141. Thereby, the striking direction length of the tool main body 101 with respect to the longitudinal direction length of the hammer bit 119 is such that the tool holder 137 holding the hammer bit 119 and the striking cylinder 141 in which the piston 129 and the striker 143 are accommodated are extended. Defined by length. For this reason, the striking direction length of the tool body 103 can be shortened as compared with the conventional hammer drill in which the motion conversion mechanism 113 is disposed at the rear position away from the long axis direction region of the striking cylinder 141.

In the hammer drill 101 configured as described above, for example, in the case of performing a drilling operation on the inner wall surface of the U-shaped groove, the major axis direction of the hammer bit 119 is the groove width as in the case of the first embodiment. The tool body 103 can be inserted into the U-shaped groove so as to be oriented, and the drilling operation can be performed. In this case, since the striking force of the striker 143 is linearly transmitted to the hammer bit 119, the striker 143 has a configuration in which a square attachment is attached to the tip of the hammer drill and the striking force of the striker 143 is transmitted to the hammer bit. The striking force can be transmitted to the hammer bit 119 without loss.

The hand grip 109 is a direction in which the grip portion 109a gripped by the operator intersects with the long axis direction of the main body portion 103, and extends in parallel with the extending direction of the striking cylinder 141. The upper and lower ends of 109 a are configured as D-shaped handles connected to the outer housing 105. For this reason, it can comprise so that the said hand grip 109 may be settled in the range of the striking direction length of the hammer drill 101. FIG.

The handgrip 109 is provided with a trigger 147 and a forward / reverse changeover switch 149 for driving and stopping the drive motor 111. In this embodiment, the trigger 147 and the forward / reverse selector switch 149 are arranged on the front side in the striking direction (the lower side in FIG. 10) in the extending direction of the handgrip 109. That is, in this embodiment, the shape of the hand grip 109 is set to a grip shape in which the thumb and forefinger are forward in the batting direction.

Further, an end region on the rear side in the striking direction of the outer housing 105 is set as a sub grip 163 that can be pressed by the entire palm. Accordingly, the operator can perform the drilling operation while holding the hand grip 109 with one hand and pressing the sub grip 163 in the striking direction with the other hand.

In the present embodiment, the power transmission mechanism 117 for transmitting the rotational output of the drive motor 111 to the hammer bit 119 is such that the rotation of the intermediate gear 185 that meshes with and engages with the drive gear 121 driven by the drive motor 111. The rotation of the intermediate shaft 186 is transmitted from the small bevel gear 188 to the tool holder 137 via the large bevel gear 189 engaged with and engaged with the small bevel gear 188. It is set as the structure. The small bevel gear 188 is integrally provided at the axial end of the intermediate shaft 186. The large bevel gear 189 is spline-fitted to the outer periphery of the tool holder 137 and is configured to rotate integrally with the tool holder 137. That is, the power transmission mechanism 117 according to this embodiment has a simple structure compared to the power transmission mechanism 117 of the first embodiment having a single intermediate shaft and a double intermediate shaft. .

Next, a modification of the second embodiment will be described with reference to FIGS. In this modification, the crank arm 191 is formed by a linear bar-like member or plate-like member. On the other hand, the connecting shaft 128 of the piston 129 has an extension 128 a that extends to the outside of the striking cylinder 141 through the escape groove 183, and the extension 128 a is connected to the crank arm 191. Therefore, according to this modification, as in the case of the second embodiment, the length in the striking direction of the tool body 101 can be shortened as compared with the conventional hammer drill.

In this modified example, a trigger 147 and a forward / reverse switching switch 149 for driving and stopping the drive motor 111 are arranged on the rear side (upper side in the drawing) of the handgrip 109 in the extending direction. That is, in this modification, the hand grip 109 has a grip shape in which the thumb and forefinger are behind in the batting direction.

In the above-described embodiment, the hammer drill 101 is described as an example of the impact tool. However, the hammer bit 119 can be applied to a hammer that performs only a linear motion in the major axis direction.

In view of the gist of the invention, the following aspects can be configured.
(Aspect 1)
“The tool bit is a striking tool that performs a predetermined machining operation on a workpiece by moving linearly at least in the long axis direction,
A tool holder that holds the tool bit so as to be relatively movable in the long axis direction, a striking element that linearly moves in the long axis direction of the tool bit and applies a striking force to the tool bit, and connected to the tool holder The impactor has a striking cylinder having an air chamber that allows compressed air to act on the striking element, and a tool main body that houses the tool holder and the striking cylinder.
The tool holder and the striking cylinder are both extended in the long axis direction of the tool bit,
A striking tool characterized in that a length dimension of the striking tool in the long axis direction of the tool bit is defined by the tool holder and the striking cylinder. "

(Aspect 2)
“A striking tool according to aspect 1,
It further has a compressed air supply cylinder for supplying compressed air to the air chamber of the blow cylinder, and the compressed air supply cylinder extends in a direction different from the extending direction of the blow cylinder. An impact tool characterized by that. "

(Aspect 3)
“A striking tool according to aspect 1 or 2,
It has a hand grip connected to the tool body and gripped by an operator to operate the impact tool, and the width direction of the hand grip is set to be the extending direction of the impact cylinder. Blow tool. "

(Aspect 4)
“A striking tool according to aspect 3,
A striking tool characterized in that a long axis direction of the tool bit, an extending direction of the compressed air supply cylinder, and an extending direction of the hand grip are all intersected. "

(Aspect 5)
“A striking tool according to aspect 1,
A motion conversion mechanism for generating compressed air in the air chamber of the striking cylinder by converting rotational motion into linear motion;
The impact tool, wherein the rotation shaft of the motion conversion mechanism is arranged in parallel with the impact cylinder in a predetermined region in the extending direction of the impact cylinder. "

(Aspect 6)
“A striking tool according to aspect 5,
The impact tool according to claim 1, wherein the rotating shaft intersects with an extending direction of the impact cylinder. "

(Aspect 7)
“A striking tool according to aspect 5 or 6,
It has a handgrip connected to the tool body and gripped by an operator to operate the impact tool, and the extension direction of the impact cylinder and the extension direction of the handgrip are set parallel to each other. Characteristic impact tool. "

(Aspect 8)
“A striking tool according to aspect 2,
An air passage for supplying the compressed air generated by the compressed air supply cylinder to the air chamber of the striking cylinder; and the air passage extends from the head side of the striking cylinder in a major axis direction of the air chamber. A striking tool configured to supply compressed air. "

(Aspect 9)
“A striking tool according to aspect 2,
An air passage for supplying compressed air generated by the compressed air supply cylinder to an air chamber of the striking cylinder, the air passage from a lateral region of the striking cylinder in a radial direction of the air chamber; A striking tool configured to supply compressed air. "

(Aspect 10)
“A striking tool according to any one of aspects 1 to 9,
A tool body, a motor housed in the tool body, and an intermediate gear housed in the tool body and transmitting the rotational output of the motor to the tool bit,
The motor and the intermediate gear are arranged such that their respective rotation axes are parallel to each other and intersect with the long axis direction of the tool bit,
In the tool main body, the strike direction rear side surface of the striker extends substantially intersecting with the strike direction,
The rotation axis of the motor is offset to the front side in the striking direction of the striking element with respect to a straight line extending in parallel with the rear side surface in the striking direction through the center of the intermediate gear. Blow tool. "

(Aspect 11)
“A striking tool according to aspect 7,
A motor that drives the tool bit; and an operation member that is provided on the hand grip and operates to drive and stop the motor.
The said operation member is arrange | positioned in the striking direction back side of the said striker in the extension area | region of the said handgrip, The striking tool characterized by the above-mentioned. "

(Aspect 12)
“A striking tool according to aspect 7,
A motor that drives the tool bit; and an operation member that is provided on the hand grip and operates to drive and stop the motor.
The said operation member is arrange | positioned in the striking direction front side of the said striker in the extension area | region of the said handgrip, The striking tool characterized by the above-mentioned. "

101 Hammer drill (blow tool)
103 Main body portion 105 Outer housing 105a Motor housing portion 105b Stroke direction rear side surface 107 Gear housing 107a Barrel portion 107b Inner wall surface 109 Hand grip 109a Grip portion 110 Side grip 111 Drive motor 111a Motor shaft 113 Motion conversion mechanism 114 Compression device 115 Stroke element 117 Power transmission mechanism 119 Hammer bit (tool bit)
121 Drive gear 123 Driven gear 125 Crank shaft 126 Crank pin 127 Crank arm 128 Connecting shaft 128a Extension portion 129 Piston 131 Air compression cylinder 131a Compression chamber 133 Air passage 137 Tool holder 137a Extension portion 141 Stroke cylinder 141a Air chamber 143 Strike ( Striker)
144 Buffer spring 145 Impact bolt 147 Trigger 149 Forward / reverse selector switch 151 First intermediate gear 152 First intermediate shaft 153 Second intermediate gear 154 Second intermediate shaft 155 Small bevel gear 157 Large bevel gear 157a Clutch teeth 159 Torque limiter 159a Clutch teeth 161 Spring 163 Subgrip 165 Ring member 165a Annular groove 167 Connection pipe 169 Vent hole 171 Tubular portion 173 Internal passage 181 Crank arm 181a U-shaped bottom region 183 Relief groove 185 Intermediate gear 186 Intermediate shaft 187 Torque limiter 188 Small bevel gear 189 Large Bevel gear 191 crank arm

Claims (7)

An impact tool that performs a predetermined machining operation on a workpiece by moving a tool bit linearly at least in the long axis direction,
A tool holder that holds the tool bit so as to be relatively movable in the long axis direction, a striking element that linearly moves in the long axis direction of the tool bit and applies a striking force to the tool bit, and connected to the tool holder The impactor has a striking cylinder having an air chamber that allows compressed air to act on the striking element, and a tool main body that houses the tool holder and the striking cylinder.
The tool holder and the striking cylinder are both extended in the long axis direction of the tool bit,
The impact tool according to claim 1, wherein a length dimension of the tool body with respect to a major axis direction of the tool bit is defined by the tool holder and the impact cylinder. The impact tool according to claim 1,
It further has a compressed air supply cylinder for supplying compressed air to the air chamber of the blow cylinder, and the compressed air supply cylinder extends in a direction different from the extending direction of the blow cylinder. An impact tool characterized by that. The impact tool according to claim 2,
It has a hand grip connected to the tool body and gripped by an operator to operate the impact tool, and the width direction of the hand grip is set to be the extending direction of the impact cylinder. Blow tool. The impact tool according to claim 3,
A striking tool characterized in that a long axis direction of the tool bit, an extending direction of the compressed air supply cylinder, and an extending direction of the hand grip are all intersected. The impact tool according to claim 1,
A motion conversion mechanism for generating compressed air in the air chamber of the striking cylinder by converting rotational motion into linear motion;
The impact tool, wherein the rotation shaft of the motion conversion mechanism is arranged in parallel with the impact cylinder in a predetermined region in the extending direction of the impact cylinder. The impact tool according to claim 5,
The impact tool according to claim 1, wherein the rotating shaft intersects with an extending direction of the impact cylinder. The striking tool according to claim 5 or 6,
It has a handgrip connected to the tool body and gripped by an operator to operate the impact tool, and the extension direction of the impact cylinder and the extension direction of the handgrip are set parallel to each other. Characteristic impact tool.

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