CN113165152A

CN113165152A - Striking working machine

Info

Publication number: CN113165152A
Application number: CN201980078438.2A
Authority: CN
Inventors: 山田英贵; 大久保贵启
Original assignee: Hitachi Koki Co Ltd
Current assignee: Koki Holdings Co Ltd
Priority date: 2018-11-29
Filing date: 2019-10-25
Publication date: 2021-07-23
Anticipated expiration: 2039-10-25
Also published as: JPWO2020110539A1; WO2020110539A1; CN113165152B; DE112019005160T5; JP7331864B2

Abstract

Minimize the number of components installed in the power transmission system of a strike machine with multiple operation modes. The hammer drill (1A) includes a rotatably driven intermediate shaft (25), and a rotational force transmission system (40) that transmits the rotational force of the intermediate shaft (25) to the tip tool (2). The rotational force transmission system (40) includes a sleeve (41) provided on the intermediate shaft (25) so as to be movable forward and backward along the intermediate shaft (25). When the sleeve (41) moves forward, the sleeve (41) engages with the intermediate shaft (25) to transmit the rotational force to the tip tool (2), and when the sleeve (41) moves backward, the sleeve is released (41) The engagement with the intermediate shaft (25) prevents the rotational force from being transmitted to the tip tool (2).

Description

Striking working machine

Technical Field

The present invention relates to a hammering machine including a tool bit that applies one or both of a hammering force and a rotational force.

Background

There is known a striking work machine having a plurality of switchable operation modes. Examples of the operation modes of the conventional striking work machine include a "rotation mode", a "striking mode", and a "rotation-striking mode". The "rotation mode" is an operation mode in which a rotational force is applied to the front end tool, and is sometimes referred to as "power drill mode". The "striking mode" is an operation mode in which striking force is applied to the front end tool, and is sometimes referred to as a "hammer mode". The "rotation-striking mode" is an operation mode in which striking force and rotational force are applied to the tip tool, and is sometimes referred to as a "hammer drill mode".

In order to switch between the plurality of operation modes as described above, it is necessary to transmit and block the driving force output from the driving source to the tip tool. Therefore, the conventional hammering machine is provided with a rotary shaft that is rotationally driven by a driving force output from a driving source, and can switch between a state in which the rotation of the rotary shaft is transmitted to the tool bit and a state in which the rotation of the rotary shaft is not transmitted to the tool bit. Specifically, a gear and a coupling member are disposed on the rotating shaft. The coupling member is always engaged with the rotary shaft and rotates integrally with the rotary shaft. On the other hand, the gear is not engaged with the rotation shaft and is movable along the rotation shaft. When the gear moves in the predetermined direction along the rotational axis, the gear engages with the coupling member and the rotation of the rotational axis is transmitted to the gear via the coupling member, and finally transmitted to the tip tool. On the other hand, when the gear moves in the direction opposite to the predetermined direction, the engagement between the gear and the coupling member is released, and the rotation of the rotary shaft is not transmitted to the gear.

Documents of the prior art

Patent document

Patent document 1: international publication No. 2017/073236

Disclosure of Invention

Problems to be solved by the invention

Conventionally, in order to transmit and block the rotation of the rotary shaft rotationally driven by the drive source to the tip tool, a plurality of members including the above-described gears, coupling members, and the like are required.

However, the greater the number of components constituting the power transmission system, the more complicated the structure becomes, and the number of assembly steps also increases. Further, the increase in the number of components of the power transmission system causes an increase in size, cost, weight, and the like of the striking work machine including the power transmission system, and also causes a reduction in operability of the striking work machine.

The purpose of the present invention is to suppress the increase in cost and the improvement in operability of a striking work machine having a plurality of operation modes.

Means for solving the problems

The striking work machine of the present invention includes a driving source, a tip tool disposed in front of the driving source and applying one or both of a striking force and a rotational force, a rotary shaft rotationally driven by the driving source with a center axis extending in a front-rear direction as a center, and a rotational force transmission system transmitting the rotational force of the rotary shaft to the tip tool, wherein the rotational force transmission system includes a sleeve provided to be movable in the front-rear direction on the rotary shaft. When the sleeve moves forward, the sleeve engages with the rotary shaft and can transmit the rotational force to the tip tool, and when the sleeve moves backward, the engagement between the sleeve and the rotary shaft is released and the rotational force cannot be transmitted to the tip tool.

Effects of the invention

According to the present invention, it is possible to suppress the increase in cost and the improvement in operability of a striking work machine having a plurality of operation modes.

Drawings

Fig. 1 is a sectional view showing the overall structure of a hammer drill.

Fig. 2(a) and (b) are partially enlarged sectional views showing the structure around the intermediate shaft.

Fig. 3(a) is a partial cross-sectional view showing the positions of the clutch member and the sleeve when the drill mode is selected, (b) is a partial cross-sectional view showing the positions of the clutch member and the sleeve when the hammer drill mode is selected, and (c) is a partial cross-sectional view showing the positions of the clutch member and the sleeve when the hammer mode is selected.

Fig. 4 is an exploded perspective view showing constituent elements of the operation mechanism.

Fig. 5 is an explanatory diagram showing a relationship between the rotational position of the dial and the forward and backward positions of the slider, the clutch member, and the sleeve when the hammer drill mode is selected.

Fig. 6 is an explanatory diagram showing a relationship between a rotational position of the dial and front and rear positions of the slider, the clutch member, and the sleeve when the drill mode is selected.

Fig. 7 is an explanatory diagram showing a relationship between the rotational position of the dial and the forward and backward positions of the slider, the clutch member, and the sleeve when the hammer mode is selected.

Fig. 8(a) to (c) are partial sectional views showing other embodiments of the hammer drill.

Detailed Description

Hereinafter, an example of an embodiment of the striking work machine according to the present invention will be described in detail with reference to the drawings. The hammering machine according to the present embodiment is a hammer drill having a plurality of switchable operation modes. The operation modes of the hammer drill according to the present embodiment include at least three operation modes, i.e., "a rotation mode (power drill mode)", "a striking mode (hammer mode)", and "a hammer drill mode (rotation-striking mode)". When the drill mode is selected, a rotational force is applied to the tip tool, and when the hammer mode is selected, a striking force is applied to the tip tool. When the hammer drill mode is selected, two forces, i.e., a turning force and a striking force, are applied to the tip tool. An example of a tip tool attached to a hammer drill and applying one or both of a striking force and a rotational force is a drill. Drill bits are used, for example, for drilling holes in concrete, stone, etc. However, the tool bit attached to the hammer drill is not limited to the drill bit, and is appropriately replaced according to the target object, the type of work to be performed on the target object, and the like.

< integral Structure >

As shown in fig. 1, the hammer drill 1A of the present embodiment includes a housing 10, a handle 11 provided on one end side of the housing 10, and a sub-handle 12 provided on the other end side of the housing 10.

A motor 20 as a driving source of the front end tool 2, a striking force transmission system 30 that converts a driving force (rotational force) output from the motor 20 into a striking force and transmits the striking force to the front end tool 2, and a rotational force transmission system 40 that transmits the driving force (rotational force) output from the motor 20 to the front end tool 2 are provided in the housing 10. In the following description, the striking force transmission system 30 and the rotational force transmission system 40 may be collectively referred to as a "power transmission system".

The electrode 20 has a stator, a rotor, and an output shaft 21. The output shaft 21 penetrates the rotor and extends in the longitudinal direction of the housing 10. In the present embodiment, the longitudinal direction of the housing 10, i.e., the direction of the output shaft 21, is defined as the front-rear direction. The side on which the sub-handle 12 is provided is defined as "front", and the side on which the handle 11 is provided is defined as "rear". The tool 2 is disposed in front of the motor 20 as a driving source if this definition is adopted.

The output shaft 21, which penetrates the rotor and extends in the front-rear direction, is rotatably supported by two

bearings

22a, 22 b. The bearing 22a rotatably supports the front side (front end side) of the output shaft 21, and the bearing 22b rotatably supports the rear side (rear end side) of the output shaft 21. The front end of the output shaft 21 passes through the bearing 22a and protrudes forward of the bearing 22 a. A gear (pinion gear 23) is provided at the tip of the output shaft 21 projecting forward of the bearing 22 a.

The motor 20 operates based on the operation of a trigger 11a provided on the handle 11. Specifically, when the trigger 11a is pulled by the operator, electric power is supplied to the motor 20 to rotate the output shaft 21. On the other hand, when the trigger 11a is released from being pulled by the operator, the power supply to the motor 20 is cut off, and the rotation of the output shaft 21 is stopped. Further, a cooling fan 24 is attached to the output shaft 21. The cooling fan 24 rotates integrally with the output shaft 21, and generates cooling air mainly for cooling the motor 20. Further, a drive circuit including a switching element, a control circuit including a hall element, and the like are disposed around the motor 20, and these circuits are also cooled by cooling air generated by the cooling fan 24.

The rotary shaft 25 and the cylinder 31 are disposed in parallel with the output shaft 21 in the housing 10. The front end of the rotary shaft 25 is rotatably supported by a bearing 25a, and the rear end of the rotary shaft 25 is rotatably supported by a bearing 25 b. A driven gear 26 that engages with the pinion gear 23 provided at the front end of the output shaft 21 is provided at the rear end of the rotary shaft 25 that penetrates the bearing 25b and protrudes rearward of the bearing 25 b. When the electric drill mode or the hammer drill mode is selected, the rotation of the output shaft 21 is transmitted to the cylinder 31 through the rotary shaft 25. That is, the rotary shaft 25 is one of the power transmission elements interposed between the output shaft 21 and the cylinder 31. Therefore, in the following description, the rotary shaft 25 may be referred to as an "intermediate shaft 25".

Striking force transmission system

As shown in fig. 1, a conversion mechanism 32 that converts the rotational motion of the intermediate shaft 25 into the reciprocating motion is provided on the intermediate shaft 25 and in front of the bearing 25 b. The conversion mechanism 32 is composed of an inner ring, an outer ring, a rotor, and a connecting rod, and is also referred to as a "linear bearing". The inner ring is supported to be rotatable relative to the intermediate shaft 25, the outer ring is disposed around the inner ring, and the rolling element is interposed between the inner ring and the outer ring. Further, the connecting rod extends from the outer peripheral surface of the outer ring to the radially outer side of the outer ring. Grooves having an arc-shaped cross section are formed in the outer peripheral surface of the inner ring and the inner peripheral surface of the outer ring, respectively. The rotor is interposed between the inner ring and the outer ring in a state where a part of the rotor is fitted in a groove formed in the inner ring and the other part of the rotor is fitted in a groove formed in the outer ring. In other words, the inner ring and the outer ring are coupled to each other so as to be relatively rotatable via a rotor.

A clutch member 33 that can move forward and backward along the intermediate shaft 25 is provided on the intermediate shaft 25 and in front of the conversion mechanism 32. The clutch member 33 is always engaged with the intermediate shaft 25, and is movable to an engagement position at which the rotation of the intermediate shaft 25 is transmitted to the conversion mechanism 32 and a non-engagement position at which the rotation of the intermediate shaft 25 is not transmitted to the conversion mechanism 32.

When the clutch member 33 is retracted to the engagement position along the intermediate shaft 25, the intermediate shaft 25 and the shift mechanism 32 are connected by the clutch member 33, and power is transmitted from the intermediate shaft 25 to the shift mechanism 32. Specifically, a claw provided at the rear end of the clutch member 33 that rotates integrally with the intermediate shaft 25 engages with a claw provided at the front end of the inner ring of the conversion mechanism 32, and the rotation of the intermediate shaft 25 is transmitted to the inner ring through the clutch member 33.

On the other hand, when the clutch member 33 moves forward along the intermediate shaft 25 to the non-engagement position, the connection between the intermediate shaft 25 and the conversion mechanism 32 is released, and the power transmission from the intermediate shaft 25 to the conversion mechanism 32 is interrupted. Specifically, the clutch member 33 engaged with the inner race is separated from the inner race to cut off the power transmission from the intermediate shaft 25 to the inner race.

The movement of the clutch member 33 as described above is realized by an operation of switching the operation mode by an operator. When the intermediate shaft 25 rotates when the clutch member 33 is at the engagement position, the inner ring rotates. Then, the outer ring rotates along the surface of the inner ring, and the connecting rod swings back and forth along with the rotation.

The coupling rod that swings as described above is rotatably coupled to the back surface of the cup-shaped piston 34 housed in the cylinder 31. The cylinder 31 accommodates a striking element 35 and an intermediate element 36 in addition to the piston 34. The pistons 34, the hammers 35, and the intermediate members 36 are arranged in a row from the rear to the front in this order, and an air chamber 37 is provided between the pistons 34 and the hammers 35. A retainer sleeve 38 as a holding portion is provided in front of the cylinder 31. The retainer sleeve 38 is integrally formed on the front end side of the cylinder 31, and the cylinder 31 and the retainer sleeve 38 are connected to each other so as not to be rotatable relative to each other. The retainer sleeve 38 is inserted into the root portion of the tip tool 2, and the retainer sleeve 38 linearly holds the root portion of the inserted tip tool 2 within a predetermined range.

When the connecting rod connected to the piston 34 swings, the piston 34 reciprocates back and forth in the cylinder 31. Here, when the intermediate shaft 25 rotates and the connecting rod swings back and forth when the clutch member 33 is at the engagement position, the above-described operation is performed. That is, the conversion mechanism 32 converts the rotational motion of the intermediate shaft 25 into the reciprocating motion of the piston 34.

When the piston 34 reciprocates in the cylinder 31, the pressure of the air chamber 37 fluctuates. When the pressure in the air chamber 37 varies, the striker 35 is driven in accordance with the pressure variation, the intermediate member 36 is struck by the striker 35, and the tool bit 2 is struck by the intermediate member 36. As a result, a striking force is applied to the tip tool 2 held by the retainer sleeve 38.

In this way, the intermediate shaft 25 is rotationally driven by the motor 20 with the center axis extending in the front-rear direction as the center. The rotational force of the intermediate shaft 25 is converted into a striking force by a striking force transmission system 30 including a cylinder 31, a conversion mechanism 32, a clutch member 33, a piston 34, a striking element 35, an intermediate member 36, an air chamber 37, a retainer sleeve 38, and the like, and is transmitted to the front end tool 2.

< rotational force transmitting System >

As shown in fig. 1, a sleeve 41 that is movable forward and backward along the intermediate shaft 25 is provided on the intermediate shaft 25 and in front of the clutch member 33. More specifically, the sleeve 41 is disposed between the clutch member 33 and the bearing 25 a. As described above, the conversion mechanism 32 is disposed in front of the bearing 25b, and the clutch member 33 is disposed in front of the conversion mechanism 32. That is, the switching mechanism 32, the clutch member 33, and the sleeve 41 are arranged between the two

bearings

25b and 25a in this order from the rear to the front. In other words, the intermediate shaft 25 passes through the shift mechanism 32, the clutch member 33, and the sleeve 41 in this order.

As shown in fig. 2(a) and (b), an inner gear 42 is formed on the inner circumferential surface of the sleeve 41, and an outer gear 43 is formed on the outer circumferential surface of the sleeve 41. On the other hand, an intermediate gear 27 engageable with the inner gear 42 is formed integrally with the intermediate shaft 25 on the outer peripheral surface of the intermediate shaft 25 penetrating the sleeve 41.

Here, the clutch member 33, which is engaged with the intermediate shaft 25 so as to transmit power even at any one of the engagement position and the non-engagement position, is always engaged with the gear 28 formed on the outer peripheral surface of the intermediate shaft 25, like the intermediate gear 27. The gear 28 is a gear formed on the outer peripheral surface of the intermediate shaft 25 simultaneously with the intermediate gear 27. Specifically, a series of gears are formed on the outer peripheral surface of the intermediate shaft 25, and then the gears are divided into front and rear parts, one part of which is an intermediate gear 27 and the other part of which is a gear 28 that is always engaged with the clutch member 33. In this way, by forming the intermediate gear 27 engaged with the sleeve 41 and the gear 28 engaged with the clutch member 33 on the intermediate shaft 25 at the same time, the manufacturing cost of the intermediate shaft 25 can be reduced.

When the sleeve 41 shown in fig. 2(a) moves in a direction (front direction/right side of the paper) away from the clutch member 33, the inner gear 42 formed on the sleeve 41 is fitted to the intermediate gear 27 formed on the intermediate shaft 25, and the inner gear 42 is engaged with the intermediate gear 27, as shown in fig. 2 (b). On the other hand, when the sleeve 41 shown in fig. 2(b) moves in a direction (rearward/left side in the drawing) to approach the clutch member 33, the inner gear 42 formed on the sleeve 41 is separated from the intermediate gear 27 formed on the intermediate shaft 25 as shown in fig. 2(a), and the engagement between the inner gear 42 and the intermediate gear 27 is released. That is, when the sleeve 41 moves forward, the sleeve 41 engages with the intermediate shaft 25, and when the sleeve 41 moves backward, the engagement between the sleeve 41 and the intermediate shaft 25 is released.

In the following description, the position of the socket 41 shown in fig. 2(b) (the position where the socket 41 is engaged with the intermediate shaft 25 and the rotational force can be transmitted to the tip tool 2 (fig. 1)) may be referred to as a "coupling position". The position of the socket 41 shown in fig. 2(a) (the position at which the engagement between the socket 41 and the intermediate shaft 25 is released and the rotational force cannot be transmitted to the tip end tool 2 (fig. 1)) may be referred to as a "non-coupling position".

As shown in fig. 2(a), an annular groove 44 is formed inside the sleeve 41 to accommodate the intermediate gear 27 when the sleeve 41 moves to the non-coupling position. In other words, the sleeve 41 is retracted to the non-coupling position, and the intermediate gear 27 is accommodated in (disengaged from) the annular groove 44, whereby the engagement between the sleeve 41 and the intermediate shaft 25 can be released. When the sleeve 41 and the intermediate shaft 25 are disengaged, the intermediate shaft 25 rotates idly relative to the sleeve 41. That is, the annular groove 44 receives the intermediate gear 27 without engaging with the intermediate gear 27.

Reference is again made to fig. 1. A cylinder gear 45 that engages with an outer gear 43 formed on the sleeve 41 is formed around the cylinder 31. The cylinder gear 45 is an annular gear formed on the entire circumference of the cylinder 31, and is spline-coupled to the outer gear 43. Therefore, when the sleeve 41 moves to the coupling position and the sleeve 41 is engaged with the intermediate shaft 25 so as to be able to transmit power, the rotational force of the intermediate shaft 25 is transmitted to the cylinder 31 through the outer gear 43 and the cylinder gear 45, and the cylinder 31 rotates. Then, the rotational force is transmitted to the tip tool 2 coupled to the cylinder 31 via the retainer sleeve 38. On the other hand, when the sleeve 41 moves to the non-coupling position and the engagement between the sleeve 41 and the intermediate shaft 25 is released, the transmission of the rotational force to the cylinder 31 is cut off, and the transmission of the rotational force to the tip tool 2 is also cut off.

In this way, the intermediate shaft 25 is rotationally driven by the motor 20 about a central axis extending in the front-rear direction. The torque of the intermediate shaft 25 is transmitted to the tip tool 2 through a torque transmission system 40 including the socket 41 (the inner gear 42 and the outer gear 43), the cylinder 31 (the cylinder gear 45), the retainer socket 38, and the like.

< position of clutch member and sleeve in each operating mode >

It will be appreciated from the foregoing description that the operating modes are switched by moving the clutch member 33 and sleeve 41 along the intermediate shaft 25 to a predetermined position. Fig. 3 shows the positions of the clutch member 33 and the sleeve 41 in each operation mode. Fig. 3(a) shows the positions of the clutch member 33 and the sleeve 41 when the drill mode is selected. Fig. 3(b) shows the positions of the clutch member 33 and the sleeve 41 when the hammer drill mode is selected. Fig. 3(c) shows the positions of the clutch member 33 and the sleeve 41 when the hammer mode is selected.

For the sake of convenience of explanation, first, the positions of the clutch member 33 and the sleeve 41 (fig. 3(b)) when the hammer drill mode is selected will be described. As shown in fig. 3(b), an elastic body 70 that urges the clutch member 33 and the sleeve 41 in a direction to separate from each other is provided around the intermediate shaft 25. The elastic body 70 in the present embodiment is a coil spring wound around the intermediate shaft 25. The coil spring 70 is disposed between the clutch member 33 and the sleeve 41 in a compressed state. Therefore, the coil spring 70 always urges the clutch member 33 rearward and the sleeve 41 forward.

As shown in fig. 3(b), when the hammer drill mode is selected, the clutch member 33 is held at the engagement position and the sleeve 41 is held at the coupling position by the biasing force of the coil spring 70. As a result, the rotational force of the intermediate shaft 25 is converted into the striking force and transmitted to the tip tool 2 (fig. 1), and the rotational force of the intermediate shaft 25 is transmitted to the tip tool 2 (fig. 1). That is, both the striking force and the rotational force are applied to the tip tool 2 shown in fig. 1.

As shown in fig. 3(a), when the operation mode is switched from the hammer drill mode to the electric drill mode, the clutch member 33 moves forward to the non-engagement position against the biasing force of the coil spring 70, while the position of the sleeve 41 is not changed. That is, the clutch member 33 moves to the non-engagement position, while the sleeve 41 stops at the connection position. As a result, the striking force is not applied to the tip tool 2 shown in fig. 1, and only the rotational force is applied.

As shown in fig. 3(c), when the operation mode is switched from the hammer drill mode to the hammer mode, the sleeve 41 is retracted to the non-coupling position against the biasing force of the coil spring 70, and the position of the clutch member 33 is not changed. That is, the sleeve 41 moves to the non-coupling position, while the clutch member 33 stops at the engagement position. As a result, only the striking force is applied to the tip tool 2 shown in fig. 1 without applying the rotational force.

< operating mechanism for switching action mode >

Next, a mechanism for switching the operation mode by moving the clutch member 33 and the sleeve 41 as described above will be specifically described.

The hammer drill 1A shown in fig. 1 is provided with an operating mechanism for switching the operation mode by moving the clutch member 33 and the sleeve 41. The operation mechanism is constituted by the operation portion 50, the slider 60, and the like shown in fig. 4. The operation unit 50 is provided on a side surface of the housing 10 (fig. 1) and operated by an operator. The slider 60 is provided inside the housing 10 (fig. 1), and moves in accordance with the operation of the operation unit 50, thereby moving the clutch member 33 and the sleeve 41 forward and backward. Specifically, the operation unit 50 is rotated by the operator, and the slider 60 slides back and forth on the intermediate shaft 25 in accordance with the rotation of the operation unit 50. Therefore, in the following description, the operation unit 50 may be referred to as a "dial 50".

The dial 50 shown in fig. 4 is rotatably supported by the housing 10 (fig. 1) via a support shaft (not shown). A handle 51 is formed on the front surface of the dial plate 50, and a movable member 52 is provided on the rear surface of the dial plate 50 in a protruding manner. The movable member 52 is provided at a position radially outward from the rotation center of the dial 50. That is, the movable member 52 is eccentric with respect to the rotation center of the dial 50, and moves in the front-rear direction in accordance with the rotation of the dial 50. That is, the movable member 52 in the present embodiment is an eccentric pin that is provided protruding from the back surface of the dial plate 50.

The slider 60 has a base plate 61, a front plate 62, and a rear plate 63. The substrate 61 is formed in a substantially rectangular shape with the front-rear direction being the longer direction. The front plate 62 and the rear plate 63 are connected to both ends of the base plate 61 in the longitudinal direction, respectively, and face each other in the front-rear direction. A strip-shaped guide plate 64 parallel to the base plate 61 is provided at the front end of the front plate 62. The guide plate 64 is inserted into a guide groove provided in the interior of the housing 10 to guide the forward and backward movement of the slider 60. Further, the slider 60 is urged rearward by the elastic body 71. The elastic body 71 in the present embodiment is a coil spring sandwiched between the slider 60 and the housing 10.

A window 61a into which the pin 52 protruding from the rear surface of the dial 50 is fitted is formed in the substrate 61. A substantially circular opening 62a through which the sleeve 41 is inserted is formed in the front plate 62, and a cutout 63a that follows the outer shape of the clutch member 33 is formed in the rear plate 63. In fig. 4, the outer gear 43 formed on the outer peripheral surface of the sleeve 41 is not shown.

As shown in fig. 2(b), the slider 60 is disposed around the clutch member 33 and the sleeve 41 so as to straddle these members. Specifically, the slider 60 is disposed around the clutch member 33 and the sleeve 41 such that the front plate 62 is positioned in front of the flange 41a formed on the sleeve 41 and the rear plate 63 is positioned behind the flange 33a formed on the clutch member 33. That is, the

flanges

33a, 41a of the clutch member 33 and the sleeve 41 are sandwiched between the rear plate 63 and the front plate 62 of the slider 60. As a result, the back surface of the front plate 62 faces the front surface of the flange 41a of the sleeve 41, and the front surface of the rear plate 63 faces the back surface of the flange 33a of the clutch member 33.

Reference is again made to fig. 4. As described above, the slider 60 moves forward and backward on the intermediate shaft 25 in accordance with the rotational operation of the dial 50. Specifically, when the dial 50 is rotated, the pin 52 fitted into the window 61a of the base plate 61 is displaced, and the slider 60 moves forward and backward in accordance with the displacement. More specifically, when the dial 50 is rotated forward, the pin 52 abuts on the front inner surface of the window 61a, and the slider 60 is pressed forward. On the other hand, when the dial 50 is rotated rearward, the slider 60 moves rearward as the pin 52 moves rearward by the biasing force of the coil spring 71.

< dial rotation position and front-rear position of slider, clutch member and sleeve >

Fig. 5 to 7 show the relationship between the rotational position of the dial 50 and the front and rear positions of the slider 60, the clutch member 33, and the sleeve 41. Fig. 5 shows the positional relationship of the above-described components when the hammer drill mode is selected. Fig. 6 shows the positional relationship of the above-described components when the drill mode is selected. Fig. 7 shows the positional relationship of the above-described members when the hammer mode is selected.

As shown in fig. 5, when the operation mode is switched to the hammer drill mode, the dial 50 is rotated so that the handle 51 is perpendicular or substantially perpendicular to the intermediate shaft 25. In other words, when the dial 50 is rotated so that the handle 51 is perpendicular or substantially perpendicular to the intermediate shaft 25, the operation mode is switched from the other mode to the hammer drill mode. At this time, the pin 52 provided on the dial 50 presses the slider 60 forward against the biasing force of the coil spring 71. Thus, the slider 60 is in the neutral position shown. When the slider 60 is in the neutral position, the front plate 62 of the slider 60 does not abut against the flange 41a of the sleeve 41, and the rear plate 63 of the slider 60 does not abut against the flange 33a of the clutch member 33. Therefore, the clutch member 33 and the sleeve 41 receive only the biasing force generated by the coil spring 70, the clutch member 33 is held at the engagement position, and the sleeve 41 is held at the coupling position.

As shown in fig. 6, when the operation mode is switched to the power drill mode, the dial 50 is rotated forward until the handle 51 is parallel or substantially parallel to the intermediate shaft 25. In other words, when the dial 50 is rotated so that the handle 51 is parallel or substantially parallel to the intermediate shaft 25, the operation mode is switched from the other mode to the power drill mode. At this time, the pin 52 provided on the dial 50 abuts against the front inner surface of the window 61a, and presses the slider 60 forward. Thereby, the slider 60 moves to the illustrated advanced position. When the slider 60 moves from the neutral position (fig. 5) to the forward position (fig. 6), the rear plate 63 located behind the flange 33a of the clutch member 33 abuts against the flange 33a, and the clutch member 33 is pushed forward against the action of the coil spring 70. On the other hand, the front plate located forward of the flange 41a of the sleeve 41 is separated from the flange 41 a. That is, the clutch member 33 moves forward, while the sleeve 41 does not move. As a result, the clutch member 33 moves from the engagement position to the non-engagement position, while the sleeve 41 is held at the connection position.

As shown in fig. 7, when the operation mode is switched to the hammer mode, the dial 50 is rotated rearward until the handle 51 is parallel or substantially parallel to the intermediate shaft 25. In other words, when the dial 50 is rotated before the handle 51 is parallel or substantially parallel to the intermediate shaft 25, the operation mode is switched from the other mode to the power drill mode. At this time, the pin 52 provided on the dial 50 retreats, and the slider 60 is urged by the coil spring 71 and moves rearward in accordance with the retreat. Thereby, the slider 60 moves to the illustrated backward position. When the slider 60 moves from the neutral position (fig. 5) to the rearward position (fig. 7), the pin 52 abuts on the flange 41a, and presses the sleeve 41 rearward against the action of the coil spring 70. On the other hand, the rear plate 63 located rearward of the flange 33a of the clutch member 33 is separated from the flange 33 a. That is, the sleeve 41 moves rearward, while the clutch member 33 does not move. As a result, the sleeve 41 moves from the coupling position to the non-coupling position, while the clutch member 33 is held at the engagement position.

As shown in fig. 4, a concave portion 62b into which a convex portion 41b formed on the front surface of the flange 41a can be fitted is formed on the inner periphery of the opening portion 62a of the front plate 62. Therefore, when the front plate 62 abuts on the flange 41a, the convex portion 41b is fitted into the concave portion 62b, and the unnecessary rotation of the sleeve 41 is restricted.

As described above, in the torque transmission system 40 provided in the hammer drill 1A according to the present embodiment, the transmission of the rotational force from the intermediate shaft 25 to the cylinder 31 is performed only by the sleeve 41 directly engaged with the intermediate shaft 25. Further, if the engagement between the intermediate shaft 25 and the sleeve 41 is released, the transmission of the rotational force from the intermediate shaft 25 to the cylinder 31 is interrupted. That is, the power transmission element interposed between the intermediate shaft 25 and the cylinder 31 is only the sleeve 41 linearly operating along the intermediate shaft 25, and the number of components of the torque transmission system 40 is reduced as much as possible.

The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention. For example, in the above embodiment, the inner gear 42 is formed on the end portion of the rear plate of the sleeve 41. However, the inner gear 42 may be formed at the front end of the sleeve 41.

Fig. 8(a) to (c) show the positions of the clutch member 33 and the sleeve 41 in each operation mode in the hammer drill 1B having the sleeve 41 with the inner gear 42 formed at the front end. Fig. 8(a) shows the positions of the clutch member 33 and the sleeve 41 when the drill mode is selected. Fig. 8(b) shows the positions of the clutch member 33 and the sleeve 41 when the hammer drill mode is selected. Fig. 8(c) shows the positions of the clutch member 33 and the sleeve 41 when the hammer mode is selected.

As shown most clearly in fig. 8(c), an inner gear 42 is formed on the inner peripheral surface of the front end portion of the sleeve 41. Note that, the intermediate gear 27 shown in fig. 8(c) is formed integrally with the intermediate shaft 25 in the same manner as in fig. 3(c), but is provided closer to the front end of the intermediate shaft 25 than the intermediate gear 27 shown in fig. 3 (c). The sleeve 41 shown in fig. 8(c) is not provided with the annular groove 44 provided in the sleeve 41 shown in fig. 2(a) and (b).

However, when the operation mode is switched from the hammer mode (fig. 8 c) to the power drill mode (fig. 8 a) or the hammer drill mode (fig. 8 b), the sleeve 41 moves forward, and the sleeve 41 engages with the intermediate shaft 25, in the same manner as in the above-described embodiment. When the operation mode is switched from the power drill mode (fig. 8 a) or the hammer drill mode (fig. 8 b) to the hammer mode (fig. 8 c), the sleeve 41 moves rearward to release the engagement between the sleeve 41 and the intermediate shaft 25, which is similar to the above embodiment.

In other words, when the hammer drill mode and the electric drill mode are selected, the sleeve 41 is positioned forward as compared to the hammer mode, which is the same as the above-described embodiment. Note that, when the hammer mode is selected, the sleeve 41 is positioned rearward in comparison with when the drill mode and the hammer drill mode are selected, similarly to the above-described embodiment.

The striking work machine according to the present invention is not limited to the striking work machine having the above-described three operation modes (electric drill mode, hammer drill mode). For example, the hammering machine according to the present invention includes a hammering machine having only two operation modes, i.e., a hammer mode and a hammer drill mode. In the hammering machine having only two operation modes, i.e., the hammer mode and the hammer drill mode, the clutch member 33 in the above embodiment is omitted.

The striking work machine of the present invention is not limited to the hammer drill. The present invention can provide the same or substantially the same operational effects as described above even when it is applicable to a percussion working machine other than a hammer drill.

Description of the symbols

1A, 1B-hammer drill, 2-front end tool, 10-housing, 11-handle, 11A-trigger, 12-sub-handle, 20-motor, 21-output shaft, 22a, 22B, 25a, 25B-bearing, 23-pinion, 24-cooling fan, 25-rotation shaft (intermediate shaft), 26-driven gear, 27-intermediate gear, 30-striking force transmission system, 31-cylinder, 32-conversion mechanism, 33-clutch member, 33a, 41A-flange, 34-piston, 35-striking member, 36-intermediate member, 37-air chamber, 38-retainer sleeve, 40-rotation force transmission system, 41-sleeve, 41B-protrusion, 42-inner gear, 43-outer gear, 44-annular groove, 45-cylinder gear, 50-operation portion (dial), 52-movable member (pin), 60-slider, 61-base plate, 61A-window, 62-front square plate, 62 a-opening, 62 b-recess, 63-rear plate, 64-guide plate, 70, 71-elastic body (coil spring).

Claims

1. A strike machine, comprising:

drive source;

A front end tool that is arranged in front of the above-mentioned driving source and applies one or both of the striking force and the rotational force;

A rotating shaft that is centered on a central shaft extending in the front-rear direction and is rotationally driven by the above-mentioned driving source; and

a rotational force transmission system for transmitting the rotational force of the above-mentioned rotating shaft to the above-mentioned tip tool,

The above-mentioned rotational force transmission system includes, on the above-mentioned rotating shaft, a sleeve provided so as to be movable in the forward and backward directions,

When the sleeve moves forward, the sleeve engages with the rotating shaft, and can transmit the rotational force to the tip tool.

When the sleeve moves rearward, the engagement of the sleeve with the rotating shaft is released, and the rotational force cannot be transmitted to the tip tool.

2. The striking machine according to claim 1, characterized in that,

An inner gear is formed on the inner peripheral surface of the sleeve,

An outer gear is formed on the outer peripheral surface of the sleeve,

When the sleeve moves forward, the inner gear engages with the intermediate gear formed on the outer peripheral surface of the rotating shaft.

When the sleeve moves rearward, the engagement between the inner gear and the intermediate gear is released.

3. The striking machine according to claim 2, characterized in that,

The said inner gear is formed in the edge part of the rear side of the said sleeve.

4. The striking machine according to claim 2, characterized in that,

The said inner gear is formed in the edge part of the front side of the said sleeve.

5. The strike machine according to any one of claims 2 to 4, wherein

An annular groove is formed on the inner side of the sleeve, and when the sleeve moves backward, the annular groove accommodates the intermediate gear without engaging with the intermediate gear.

6. The strike machine according to any one of claims 1 to 5, wherein

having a striking force transmission system that converts the rotational force of the rotating shaft into striking force and transmits it to the tip tool,

The above strike force transmission system includes:

A conversion mechanism that converts the rotational motion of the above-mentioned rotating shaft into a reciprocating motion; and

A clutch that is movably provided on the rotating shaft in the front-rear direction and moves to an engaged position where power is transmitted from the rotating shaft to the switching mechanism, and a non-engaging position that does not transmit power from the rotating shaft to the switching mechanism part,

The clutch member is engaged with the rotating shaft so as to be able to transmit power even in any of the engagement position and the non-engagement position.

7. The strike machine of claim 6, wherein

having two bearings rotatably supporting the above-mentioned rotating shaft,

The conversion mechanism, the clutch member, and the sleeve are arranged between the two bearings in this order.

8. The strike machine according to claim 6 or 7, characterized in that:

The above-mentioned striking force transmission system further includes a cylinder and a piston accommodated in the cylinder,

The above-mentioned conversion mechanism converts the rotary motion of the above-mentioned rotating shaft into the reciprocating motion of the above-mentioned piston,

The said rotational force transmission system further includes the cylinder block gear provided in the periphery of the said cylinder block and engaged with the said outer side gear formed in the said sleeve.

9. The striking machine according to any one of claims 6 to 8, characterized in that:

have:

an operating unit operated by an operator; and

A movable member that moves in accordance with the operation of the operating portion and moves the sleeve in the front-rear direction.

10. The strike machine of claim 9, wherein

an elastic body provided around the rotating shaft and urging the clutch member and the sleeve in a direction away from each other,

The movable member moves the sleeve backward against the action of the elastic body.

11. The strike machine according to any one of claims 8 to 10, characterized in that:

having a motor as the above-mentioned drive source,

A driven gear that engages with a pinion provided at one end of the output shaft of the motor is provided at one end of the rotating shaft,

The output shaft, the rotating shaft, and the cylinder block are arranged in parallel with each other.