JP3098963B2 - Switching mechanism for rotating tools - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mechanism for switching the operation of a rotary tool, and more particularly to a switching mechanism for a rotary tool capable of switching between a drill mode, a hammer drill mode, and a hammer mode.

[0002]

2. Description of the Related Art [First Conventional Example] As a rotary tool, there is a rotary tool capable of switching between three modes of a drill mode, a hammer mode, and a hammer drill mode. The drill mode is a mode in which the tool portion at the tip is rotated, and the hammer mode is a mode in which the tool portion is reciprocated in the axial direction to perform a striking operation. The hammer drill mode is a mode in which the tool portion is simultaneously rotated and reciprocated in the axial direction to perform a striking operation.

As a rotary tool having the three-mode switching function, there is a technique disclosed in Japanese Patent Application Laid-Open No. Hei 6-210507. FIGS. 11 and 12 show the switching function of the rotary tool. As shown in FIG. 11, the rotational drive of the motor is transmitted to the gear 9 via the pinion 16. The gear 9 is integrally fixed to the intermediate shaft 60,
The intermediate shaft 60 rotates with the rotation of.

[0004] A clutch 61 is spline-coupled to the intermediate shaft 60. That is, the clutch 61 is
, And is slidably held in the directions of arrows 90 and 91. Fitting recesses 63 and 64 (FIG. 11B) are formed at both ends of the clutch 61. A transmission gear 66 is rotatably attached to the intermediate shaft 60. The final gear 6 is meshed with the transmission gear 66, and the rotation of the final gear 6 causes the tool to rotate.

The transmission gear 66 has a transmission-gear-side fitting projection 67.
The transmission gear side fitting protrusion 67 can be engaged with the fitting recess 63 formed in the clutch 61 described above. FIG. 11A shows a drill mode, in which the clutch 61 moves in the direction of the arrow 91 and the fitting recess 63 and the transmission gear side fitting projection 67 of the transmission gear 66 are engaged.

In the state shown in FIG. 11A, the transmission gear 66 also rotates in response to the rotation of the intermediate shaft 60 and the clutch 61. The rotation of the transmission gear 66 rotates the final gear 6, and the tool part rotates to operate in the drill mode.

The boss 3 is rotatably mounted on the intermediate shaft 60. The boss 3 has a boss-side fitting projection 6.
5 is formed, and can be engaged with the fitting concave portion 64 of the clutch 61. When the boss 3 is rotated, the rotation is transmitted to the arm 17 as a reciprocating movement in the directions of arrows 90 and 91, and the reciprocating movement of the arm 17 performs a striking operation on the tool portion.

FIG. 11C shows a hammer mode, in which the clutch 61 moves in the direction of arrow 90 and the fitting recess 64 and the boss-side fitting projection 65 of the boss 3 are engaged. In the state shown in FIG. 11C, the boss 3 rotates in response to the rotation of the intermediate shaft 60 and the clutch 61. The arm 17 reciprocates by the rotation of the boss 3, and the tool performs a striking operation to operate in a hammer mode.

FIG. 11B shows a hammer drill mode. The clutch 61 is located at an intermediate position between FIGS. 11A and 11C, and both the transmission gear 66 and the boss 3 rotate according to the rotation of the clutch 61. As a result, the impact operation is transmitted to the tool portion together with the rotation operation, and the tool portion performs an impact while rotating, and operates in a hammer drill mode.

As described above, the clutch 61 is connected to the intermediate shaft 60.
By controlling the movement in the directions of arrows 90 and 91 above,
Perform mode switching. FIG. 12 shows a mechanism for moving the clutch 61 in the axial direction. A groove 62 is formed in the center of the clutch 61 in the circumferential direction. The head 68a of the eccentric pin 68 is fitted in the concave groove 62. The eccentric pin 68 is housed in a sleeve 73, and the eccentric pin 68 and the sleeve 73 are held in a bottomed hole 72 of the change lever body 71.

The change lever body 71 is rotated by operating a knob of the change lever located outside the housing. Since the eccentric pin 68 is provided at an eccentric position with respect to the rotation center of the change lever main body 71, the eccentric pin 6
8 moves in the directions of arrows 90 and 91. That is, by operating the knob of the change lever, the clutch 61 can be controlled to move in the directions of arrows 90 and 91,
As shown in FIG. 11, a drill mode, a hammer drill mode and a hammer mode can be selected.

As shown in FIG. 12, a change lever body 71 has a bottomed hole 72 between a sleeve 73 and
O-rings 69 and 70 are interposed. This O-ring 6
9 and 70, the fitting concave portion 63 or the fitting concave portion 64 of the clutch 61 is formed by the transmission gear side fitting convex portion 67 and the boss side fitting convex portion 65.
The shock at the time of fitting into the device can be absorbed, and the mode can be switched smoothly.

[Second Conventional Example] FIGS. 13 and 14 show a second conventional example. This second conventional example is a rotary tool that switches between two modes, a drill mode and a hammer drill mode. As shown in FIG. 13A, the rotation drive from the motor is transmitted to the gear 9. The gear 9 is integrally fixed to the intermediate shaft 60, and the intermediate shaft 60 rotates with the gear 9. A pinion 83 is formed integrally with the intermediate shaft 60, and a gear for rotational driving always meshes with the pinion 83 to transmit a rotational operation to the tool portion.

A clutch 87 is rotatably mounted on the intermediate shaft 60. The clutch 87 is movable on the intermediate shaft 60 in the directions of arrows 90 and 91. The boss 3 is rotatably attached to the intermediate shaft 60, and the boss 3 transmits the rotating operation to the arm 17 as a reciprocating movement in the directions of arrows 90 and 91 to hit the tool portion.

FIG. 13B shows details of the intermediate shaft 60. Splines 81 and 82 are formed on the intermediate shaft 60. On the other hand, as shown in FIG. 14E, splines 74 and 75 are formed on the inner periphery of the clutch 87. In addition,
FIG. 14C is a cross-sectional view in the XIC-XIC direction shown in FIG. 14E, and FIG. 14D is a cross-sectional view in the XID-XID direction shown in FIG. 14E.

FIGS. 14A and 14B show the intermediate shaft 60 and the clutch 87.
Indicates the positional relationship. Clutch 87 is spring 8
9 (FIG. 13A) is constantly urged in the direction of arrow 90. In the hammer drill mode, the clutch 87 is located on the intermediate shaft 60 in the state shown in FIG. 14A. That is, the clutch 87 is pressed in the direction of arrow 90 by the spring 89, and the spline 74 of the clutch 87,
75 and the splines 81 and 82 formed on the intermediate shaft 60 are engaged with each other, and the clutch 87 rotates according to the rotation of the intermediate shaft 60.

FIG. 13A shows one end of the clutch 87.
, A reciprocating bearing claw 85 is formed at the end of the boss 3. When the clutch 87 is in the state shown in FIG. 14A, the clutch pawl 86 of the clutch 87 and the reciprocating bearing pawl 85 of the boss 3 are engaged with each other. As a result, the rotation of the intermediate shaft 60 is controlled by the clutch 8
The arm 17 reciprocates and the striking operation is transmitted to the tool portion.

Since the rotation of the intermediate shaft 60 is constantly transmitted to the tool via the pinion 83 as described above, FIG.
When the clutch 87 is located in the state shown in FIG. 4A, it operates in the hammer drill mode.

On the other hand, in the case of the drill mode, the clutch switching lever 88 (FIG. 13A) is rotated. The rotation of the clutch switching lever 88 causes the lever pin 84 to move in the direction of the arrow 91.
The lever pin 84 is fitted in a clutch recess 76 formed in the clutch 87, and the clutch 87 compresses the spring 89 by the pressing of the lever pin 84, and the arrow 9.
Move in one direction.

The movement of the clutch 87 causes the clutch pawl 86 and the reciprocating bearing pawl 8 formed on the boss 3 to move.
5, the rotation of the intermediate shaft 60 is not transmitted to the boss 3, and only the rotation operation is transmitted to the tool portion. Thus, the operation in the drill mode is performed.

FIG. 14F shows a working process of the clutch 87. The above-described spline 7 is provided in the clutch 87.
4 and 75, the clutch 87
A machining spline 77 is formed over the entire length of the inside of the inside, and then the central portion of the machining spline 77 is removed to remove the spline 7.
4, 75 are obtained.

[0022]

The above conventional rotary tool has the following problems. First, in the first conventional example shown in FIGS.
It is spline-coupled to 0 and is always rotating with the intermediate shaft 60. The head 68a of the eccentric pin 68 is fitted in the concave groove 62 of the clutch 61. For this reason, there is a problem that the wear of the head 68a of the eccentric pin 68 is remarkable due to the clutch 61 that is always rotating, and the durability is lacking.

Further, there is also a problem that a friction noise is generated due to the contact between the head 68a and the groove 62 of the clutch 61 which is always rotating. Further, the concave groove 62 of the clutch 61
The eccentric pin 68 generates heat due to frictional heat between the eccentric pin 68 and the head 68a, and this heat is transmitted to the change lever main body 71, and the switching lever formed of resin or the like may be deformed. In addition, there is a problem that the safety of the work is reduced due to the heat generated by the switching lever.

In the second conventional example, in the hammer drill mode, the clutch 87 moves in the direction of the arrow 90 under the pressure of the spring 89, and the lever pin 84
Are positioned so as not to contact the clutch 87. And
In the drill mode, as shown in FIG. 13A, the lever pin 84 presses the clutch 87 to move the clutch 87 in the direction of arrow 91, the engagement between the clutch 87 and the intermediate shaft 60 is released, and the clutch 87 rotates. It will be in a state where it does not.

As described above, the lever pin 84 does not come into contact with the rotated clutch 87, and the problem as in the first conventional example does not occur. However, the second conventional example is a two-mode switching between the drill mode and the hammer drill mode, and cannot be applied to a mechanism for switching the three modes of the drill mode, the hammer drill mode, and the hammer mode.

Therefore, the present invention can improve the durability of the switching member in a rotary tool capable of switching between three modes of a drill mode, a hammer drill mode, and a hammer mode, and further, does not generate frictional noise during driving. It is another object of the present invention to provide a rotary tool operation switching mechanism capable of avoiding deformation and heat generation of a resin lever or the like of a switching member due to frictional heat and capable of ensuring work safety.

[0027]

According to a first aspect of the present invention, there is provided an operation switching mechanism for a rotary tool, wherein the operation switching mechanism is mounted on an intermediate shaft which rotates by being driven by a driving unit, and moves in the axial direction of the intermediate shaft. Thereby, the first transmission member, which is located in an engaged state that rotates with the intermediate shaft or a released state that is rotatable with respect to the intermediate shaft, is attached to the intermediate shaft,
By moving in the axial direction of the intermediate shaft, the second transmission member and the first transmission member are positioned in an engaged state in which the intermediate transmission rotates with the intermediate shaft or in a released state in which the intermediate transmission becomes rotatable with respect to the intermediate shaft. And, the impact driving member that converts the rotating operation into a striking operation and transmits it to the tool portion, rotates with the second transmitting member,
A switching member that directly or indirectly abuts a rotation driving member that transmits the rotation operation to the tool portion, or one of the first transmission member and the second transmission member, wherein the switching member is connected to the first transmission member. The switching member comes into contact with the second transmission member directly or indirectly to move the second transmission member by directly or indirectly contacting the first transmission member to move the first transmission member from the engaged state to the release state. In this way, the state is changed from the engaged state to the released state, and the switching member does not abut on either of the first transmitting member and the second transmitting member, so that both the first transmitting member and the second transmitting member are brought into the engaged state. It is characterized by

A rotary tool operation switching mechanism according to a second aspect of the present invention is the rotary tool operation switching mechanism according to the first aspect, further comprising a lock member that is movable in the axial direction of the intermediate shaft and is not rotatable. A lock member that meshes with the second transmission member at the reference position when the second transmission member is switched from the engaged state to the released state, and a biasing member that biases the lock member toward the reference position. It is characterized by:

According to a third aspect of the present invention, the operation switching mechanism for a rotary tool rotates upon receiving a drive from a driving unit, is mounted on an intermediate shaft having an engaging portion, and moves in the axial direction of the intermediate shaft. By this, the first transmission member, which is located in the engaged state that rotates with the intermediate shaft, or the release state that is rotatable with respect to the intermediate shaft, rotates with the first transmission member, and turns the rotation operation into a striking operation. A rotary drive member that is located in an impact drive member that converts and transmits to the tool portion, an engagement state that rotates with an engagement portion of the intermediate shaft, or a release state that is rotatable with respect to the engagement portion of the intermediate shaft. And a switching member that directly or indirectly abuts the rotation driving member that transmits the rotation operation to the tool portion when located in the engaged state, either the first transmission member or the rotation driving member, The switching member is a first transmission unit Directly or indirectly, and moving the first transmission member to change the engagement state to the release state, wherein the switching member directly or indirectly contacts the rotation drive member to move the rotation drive member. The state is changed from the engaged state to the released state, and the switching member does not come into contact with either of the first transmission member and the rotation drive member, thereby bringing both the first transmission member and the rotation drive member into the engagement state. It is characterized by.

According to a fourth aspect of the present invention, there is provided a rotary tool operation switching mechanism according to the third aspect, wherein the rotary driving member is moved in the axial direction of the rotary shaft to release the engaged state. State, and is a lock member that is movable in the axial direction of the rotation drive member and that cannot rotate. When the rotation drive member switches from the engaged state to the release state, the rotation drive is performed at the reference position. A lock member that meshes with the member and a biasing member that biases the lock member toward the reference position are provided.

[0031]

In the operation switching mechanism for a rotary tool according to the first aspect, the switching member comes into direct or indirect contact with the first transmission member, and is released from the engaged state by moving the first transmission member. State. Further, the switching member directly or indirectly abuts the second transmission member, and the second transmission member is moved to change the engagement state to the release state. Then, the switching member does not come into contact with either the first transmission member or the second transmission member, so that both the first transmission member and the second transmission member are engaged.

That is, when the first transmission member is released by the switching member, only the second transmission member is engaged, and the rotation operation is transmitted to the tool portion via the rotation driving member (rotation operation). Operation function). Further, when the second transmitting member is released by the switching member, only the first transmitting member is engaged, and the striking operation is transmitted to the tool portion via the striking driving member (stripping operation function). .

Further, when the switching member does not come into contact with either the first transmission member or the second transmission member, both the first transmission member and the second transmission member are engaged, and each of the tool portions is rotated. The rotation operation and the impact operation are transmitted to the tool portion via the drive member and the impact drive member (impact rotation operation function).

As described above, by performing the switching operation of the switching member, the rotating operation function, the striking operation function, or the striking rotating operation function can be selected.

When the switching member comes into direct or indirect contact with the first transmission member or the second transmission member, the first transmission member and the second transmission member move and are switched from the engaged state to the released state. . That is, the first transmission member and the second transmission member are rotatable with respect to the intermediate shaft, and do not rotate with the intermediate shaft.

Therefore, the durability of the switching member can be improved without abrasion of the switching member that directly or indirectly contacts the first transmission member and the second transmission member. Further, since the first transmission member and the second transmission member do not rotate, the frictional noise does not occur during driving due to the contact of the switching member. Further, the switching member does not generate heat due to frictional heat. For example, a resin lever or the like connected to the switching member is not deformed and does not generate heat, so that work safety can be achieved.

In the operation switching mechanism for the rotary tool according to the second aspect, the lock member meshes with the second transmission member at the reference position when the second transmission member switches from the engaged state to the released state. And this lock member cannot rotate. Therefore, the rotation of the second transmission member located in the release state is stopped and locked, and the unexpected rotation of the tool portion can be reliably prevented.

The lock member is movable in the axial direction of the intermediate shaft. For this reason, in a state where the rotation angle of the second transmission member is deviated from the engagement angle with the lock member,
When the transmission member is switched from the engaged state to the released state, the lock member is pressed by the second transmission member and moves in the axial direction of the intermediate shaft. Therefore, even when the rotation angle of the second transmission member deviates from the engagement angle with the lock member, the switching member can be switched, and the second transmission member can be switched from the engaged state to the released state. Can be.

Further, the lock member is engaged with the second transmission member at the reference position, and the lock member is urged toward this reference position by the urging member. Therefore, the lock member can be always held at the reference position. Further, even when the lock member is pressed and moved by the shift of the meshing angle of the second transmission member, the lock member immediately returns to the reference position when the shift of the meshing angle is eliminated, and the second transmission member is moved. Can be engaged.

In the operation switching mechanism for a rotary tool according to the third aspect, the switching member directly or indirectly abuts the first transmission member, and the first transmission member is moved to switch from the engaged state to the released state. I do. Further, the switching member directly or indirectly abuts the rotary drive member, and the rotary drive member is moved to change the engagement state to the release state. Further, the switching member does not come into contact with either the first transmission member or the rotation driving member, so that both the first transmission member and the rotation driving member are engaged.

That is, when the first transmission member is released by the switching member, only the rotation driving member is engaged, and the rotation operation is transmitted to the tool portion (rotation operation function). Also, when the rotation driving member is released by the switching member, only the first transmission member is in the engaged state, and the striking operation is transmitted to the tool portion via the striking driving member (stripping operation function).

Further, when the switching member does not come into contact with either the first transmission member or the rotary driving member, both the first transmission member and the rotary driving member are engaged, and the rotating operation and the hitting operation are performed on the tool portion. Is transmitted (stroke rotation operation function).

As described above, by performing the switching operation of the switching member, the rotating operation function, the striking operation function, or the striking rotating operation function can be selected.

When the switching member comes into direct or indirect contact with the first transmission member or the rotary drive member, the first transmission member and the rotary drive member move and are switched from the engaged state to the released state. That is, the first transmission member and the rotation driving member are rotatable with respect to the intermediate shaft and the engaging portion of the intermediate shaft, respectively, and are not rotated with the intermediate shaft and the engaging portion of the intermediate shaft.

Therefore, the durability of the switching member can be improved without abrasion of the switching member that directly or indirectly contacts the first transmission member and the rotary drive member. In addition, since the first transmission member and the rotation drive member are not rotated, no friction noise is generated by the contact of the switching member. Further, the switching member does not generate heat due to frictional heat. For example, a resin lever or the like connected to the switching member is not deformed and does not generate heat, so that work safety can be achieved.

In the operation switching mechanism for a rotary tool according to the fourth aspect, the rotary driving member is switched between the engaged state and the released state by moving in the axial direction of the rotary shaft.
The lock member meshes with the rotation drive member at the reference position when the rotation drive member switches from the engaged state to the release state. And this lock member cannot rotate. Therefore, the rotation of the rotation drive member located in the release state is stopped and locked, and the unexpected rotation of the tool portion can be reliably prevented.

The lock member is movable in the axial direction of the rotary drive member. For this reason, when the rotation angle of the rotation drive member is shifted from the engagement state to the release state in a state where the rotation angle of the rotation drive member is shifted from the engagement angle with the lock member, the lock member is pressed by the rotation drive member in the axial direction. Moving. Therefore, even when the rotation angle of the rotation drive member is deviated from the engagement angle with the lock member, the switching member can be switched, and the rotation drive member can be switched from the engaged state to the released state. .

Further, the lock member is engaged with the rotary drive member at the reference position, and the lock member is urged toward this reference position by the urging member. Therefore, the lock member can be always held at the reference position. Further, even when the lock member is pressed and moved due to a shift in the meshing angle of the rotary drive member, the lock member immediately returns to the reference position and meshes with the rotary drive member when the shift in the meshing angle is resolved. can do.

[0049]

BEST MODE FOR CARRYING OUT THE INVENTION

[First Embodiment] A first embodiment of an operation switching mechanism for a rotary tool according to the present invention will be described with reference to the drawings. FIG. 1 is a side sectional view of the entire hammer drill according to the present embodiment. As shown in FIG. 1, the hammer drill is provided with a motor 15 as a drive unit.
5 drives the pinion 16 to rotate.

The pinion 16 meshes with the gear 9, and the gear 9 is integrally fixed to the intermediate shaft 2. The intermediate shaft 2 has both ends supported by bearings and is attached to the housing 10.

FIG. 2 is a detailed drawing of the vicinity of the intermediate shaft 2. An intermediate shaft spline portion 2T is formed at the center of the intermediate shaft 2. A second clutch 5 as a second transmission member is attached to the intermediate shaft 2. This second
The clutch 5 is slidably held in the axial direction of the intermediate shaft 2 (directions of arrows 90 and 91).

The second clutch 5 includes a second clutch engaging portion 5
M (see FIG. 2B) is formed, and the second clutch engagement portion 5M is engageable with an intermediate shaft spline portion 2T formed on the intermediate shaft 2. When the second clutch engaging portion 5M is engaged with the intermediate shaft spline portion 2T (engaged state), the second
The clutch 5 rotates with the rotation of the intermediate shaft 2.

On the other hand, the second clutch 5 has an arrow 91
When the second clutch 5 is moved in the direction and the engagement between the second clutch engagement portion 5M and the intermediate shaft spline portion 2T is released (disengaged state), the second clutch 5 becomes rotatable with respect to the intermediate shaft 2. The second clutch 5 is always urged in the direction of arrow 90 by the spring 12.

The second clutch 5 is provided with a second clutch gear 5G. As shown in FIG. 1, the second clutch gear portion 5G meshes with a final gear 6 as a rotary drive member. Arrow 90 of the second clutch 5,
Regardless of the movement in the 91 direction, the second clutch gear portion 5
G and the final gear 6 always maintain the meshing relationship.
It rotates with the clutch 5.

The final gear 6 is mounted on a tool holder 25. The final gear 6 and the tool holder 25 are connected by a clutch mechanism by the elastic force of the disc spring 19. The disc spring 19 is a washer 21,
The final gear 6 is attached by a retaining ring 20 to provide elasticity.

The second clutch 5 moves in the direction of arrow 90,
When engaged with the intermediate shaft spline portion 2T of the intermediate shaft 2 (FIG. 2A), the second clutch 5 rotates with the intermediate shaft 2, and the final gear 6 rotates accordingly. Then, according to the final gear 6, the tool holder 25
Rotates, and the bit 24 as a tool part performs a rotating operation.

When a certain load is applied to the bit 24 during the operation, the clutch mechanism between the final gear 6 and the tool holder 25 is disengaged against the elasticity of the disc spring 19, and the bit 24
The rotation is not transmitted to the motor. Thereby, the safety of the work is achieved and the load on the motor 15 is avoided.

A locking gear 13 as a locking member is fixed to the housing 10 by bolts 14. When the second clutch 5 moves in the direction of arrow 91 and is in the released state, the locking gear 13 engages with the locking spline portion 5K (see FIG. 2B) of the second clutch 5, and the second clutch 5 To a locked state where it cannot rotate.

A boss 3 as a striking drive member is provided on the intermediate shaft 2.
Is rotatably mounted. The boss 3 is provided with an arm 17, and when the boss 3 rotates, the rotation is reciprocated in the directions of arrows 90 and 91 (strike operation).
And transmitted to the piston cylinder 18. The reciprocating motion of the piston cylinder 18 is transmitted to the bit 24 via the first hammer 22 and the second hammer 23, and the bit 24 performs a striking operation.

The intermediate shaft 2 has a first transmission member as a first transmission member.
A clutch 4 is rotatably mounted. This first
Similarly to the second clutch 5, the clutch 4 also has a first clutch engagement portion 4M (see FIG. 2C) formed by an arrow 91.
When it moves in the direction, it is designed to engage with an intermediate shaft spline portion 2T formed on the intermediate shaft 2. When the first clutch engaging portion 4M is engaged with the intermediate shaft spline portion 2T (engaged state), the first clutch 4 rotates with the rotation of the intermediate shaft 2.

On the other hand, the first clutch 4 is set to the arrow 90
When the first clutch 4M moves in the direction and the engagement between the first clutch engaging portion 4M and the intermediate shaft spline portion 2T is released (disengaged state), the first clutch 4 becomes rotatable with respect to the intermediate shaft 2. A spring 11 is provided between the boss 3 and the first clutch 4.
Is provided, and the first clutch 4 is always urged in the arrow 91 direction.

As shown in FIG. 2A, the boss 3 has a boss engaging portion 3G, while the first clutch 4 has a first clutch spline portion 4G spline-coupled to the boss engaging portion 3G. Is formed. Regardless of the movement of the first clutch 4 in the directions of the arrows 90 and 91, the first clutch spline portion 4G and the boss engaging portion 3G always maintain the coupling relationship, and the boss 3 rotates with the first clutch 4. It has become.

As shown in FIG. 2, a pin 7 serving as a switching member is provided near the intermediate shaft 2 below the intermediate shaft spline portion 2T.
Is located. The pin 7 is fixed to a switching lever 8, and the switching lever 8 projects outside the housing 10 (FIG. 1). The switching lever 8 can be rotated from outside. The switching lever 8 and the pin 7 are omitted in FIG.

FIG. 3 shows details of the switching lever 8 and the pin 7. FIG. 3A is a plan view, and FIG.
It is arrow sectional drawing from IB direction. As shown in FIG. 3A, the pin 7 is fixed at an eccentric position with respect to the rotation center of the switching lever 8, and moves to the position P1, P2 or P3 by rotating the switching lever 8.

[0065] Further, as shown in FIG. 3B, if the pin 7 is moved to the position P 3, the flange portion 4F of the first clutch 4
To come into contact with. Note that the pin 7 is located at the position P 2
, The pin 7 similarly comes into contact with the flange portion 5F of the second clutch 5 (not shown).

Next, the mode switching operation in this embodiment will be described. FIG. 2A shows a state of the hammer drill mode. In this case, the switching lever 8 is moved to the position shown in FIG.
Is located at the position P1 shown in FIG. At this time, the pin 7 is located in a state where it does not contact either the first clutch 4 or the second clutch 5. Since the pin 7 does not contact the first clutch 4 and the second clutch 5, the first clutch 4 and the second clutch 5
12 to engage with the intermediate shaft spline portion 2T formed on the intermediate shaft 2 (engaged state).

Thus, both the first clutch 4 and the second clutch 5 rotate with the rotation of the intermediate shaft 2. That is, a rotation operation is transmitted to the bit 24 via the final gear 6 and the tool holder 25 by the rotation of the second clutch 5. In addition, by the rotation of the first clutch 4, a striking operation of reciprocating in the axial direction is transmitted to the bit 24 via the boss 3 and the arm 17. In this manner, the bit 24 operates in a hammer drill mode in which a hit is performed while rotating.

FIG. 2B shows a state of the hammer mode. When switching to hammer mode, switch lever 8
Is rotated to move the pin 7 from the position P1 shown in FIG.
Move to Thereby, as shown in FIG. 2B, the pin 7 presses the flange portion 5F of the second clutch 5 in the direction of the arrow 91, and the second clutch 5 moves against the elastic force of the spring 12.

Then, the engagement between the second clutch engaging portion 5M of the second clutch 5 and the intermediate shaft spline portion 2T of the intermediate shaft 2 is released, and the second clutch 5 is rotatable with respect to the intermediate shaft 2. The state, that is, the free state in which the intermediate shaft 2 does not rotate. Since the second clutch 5 is in the free state, the rotation operation is not transmitted to the bit 24. In this case,
As in the case of FIG. 2A, since the first clutch engaging portion 4M is engaged with the intermediate shaft spline portion 2T, the first clutch 4 is transmitted to the bit 24 and operates in the hammer mode.

As shown in FIG. 2B, when the second clutch 5 moves in the direction of the arrow 91, the locking spline portion 5K formed on the outer periphery of the flange portion 5F of the second clutch 5
Meshes with the lock gear 13 shown in FIG. 1 and enters a locked state in which rotation is impossible. Thereby, the bit 24 can be prevented from rotating unexpectedly during the operation in the hammer mode, and work safety can be improved.

In the case of the hammer mode, the hammer mode bit 24 is attached, but there are cases where the angle of the bit 24 needs to be manually adjusted. In this case, the switching lever 8 is rotated to position the pin 7 on the range H1 between the positions P1 and P2 (chisel-free mode).

As a result, the second clutch 5 is positioned between the state shown in FIG. 2A and the state shown in FIG. 2B. That is, the second clutch 5 is disengaged from the intermediate shaft spline portion 2T of the intermediate shaft 2, and the locking spline portion 5K
Are not engaged with the lock gear 13. Then, the angle of the bit 24 can be easily manually adjusted without receiving a load on the intermediate shaft 2.

FIG. 2C shows a state of the drill mode. When switching to drill mode, switch lever 8
Is rotated to move the pin 7 from the position P1 shown in FIG. 3A to P3. Thereby, as shown in FIG. 2C, the pin 7 presses the flange portion 4F of the first clutch 4 in the direction of the arrow 90, and the first clutch 4 moves against the elastic force of the spring 11.

Then, the engagement between the first clutch engaging portion 4M of the first clutch 4 and the intermediate shaft spline portion 2T of the intermediate shaft 2 is released, and the first clutch 4 is rotatable with respect to the intermediate shaft 2. That is, a free state in which the rotation is not accompanied by the intermediate shaft 2 is established. Since the first clutch 4 is in the free state, the striking operation is not transmitted to the bit 24. In this case, since the second clutch 5 is engaged with the intermediate shaft spline portion 2T of the intermediate shaft 2 as in the case of FIGS. Is transmitted to perform the operation in the drill mode.

As described above, the mode is switched by rotating the switching lever 8 and moving the position of the pin 7. Here, in the hammer drill mode shown in FIG. 2A, the pin 7 does not abut on either the first clutch 4 or the second clutch 5.

In the hammer mode shown in FIG. 2B,
The pin 7 comes into contact with the second clutch 5, but the second clutch 5
Is in a state in which the intermediate shaft 2 is disengaged from the intermediate shaft spline portion 2T and thus does not rotate. Further, in the drill mode shown in FIG. 2C, the pin 7 abuts on the first clutch 4, but also in this case, the first clutch 4 is in a state where the engagement with the intermediate shaft spline portion 2T of the intermediate shaft 2 is released. Because it is not rotating.

As described above, the pin 7 does not come into contact with the first clutch 4 and the second clutch 5 that rotate in any mode, so that the pin 7 is not worn by the rotational contact and the durability of the pin 7 can be improved. . Friction noise between the rotating first clutch 4 and second clutch 5 and the pin 7 does not occur. Further, since the pin 7 does not generate heat due to frictional heat, the switching lever 8 is not deformed due to the heat generation, and the work safety can be improved.

Note that the first clutch 4 and the second clutch 5 in the present embodiment have shapes as shown in FIGS. For this reason, in the processing steps of the first clutch 4 and the second clutch 5, it is not necessary to remove the central part of the inner working spline unlike the conventional clutch 87 shown in FIG. 14F, for example, and the inner diameter L1 (FIG. 14
The dimension control of E) is not difficult.

In the present embodiment, the pin 7 directly contacts the first clutch 4 and the second clutch 5 to move them. However, the pin 7 is indirectly contacted and moved by interposing other members. You may.

[Second Embodiment] Next, a second embodiment of the rotary tool operation switching mechanism according to the present invention will be described with reference to FIGS. FIG. 4 is a side sectional view of the entire hammer drill according to the present embodiment, and FIG.
6A, 6B, and 6C are all sectional views taken in the direction of arrows VI-VI shown in FIG.

In this embodiment, a locking spline portion 5K is formed on the outer periphery of the flange portion 5F of the second clutch 5, as in the first embodiment. In this embodiment, a lock plate 50 is provided instead of the lock gear 13 shown in the first embodiment (see FIGS. 5 and 6). The lock plate 50 is formed with a groove 50K that meshes with the locking spline portion 5K of the flange portion 5F of the second clutch 5.

As shown in FIG. 5, two bolts 51 and 52 penetrate through the lock plate 50, and are not rotatable by being supported by the two bolts 51 and 52. The bolts 51 and 52 are fixed to the housing 10 (see FIG. 6).

The lock plate 50 is provided movably in the directions of arrows 90 and 91 along the bolts 51 and 52. A compression coil spring 53 (FIG. 6) is attached to the bolt 51, and the lock plate 50
Biased in the direction. In this embodiment, the bolt 51 is used.
The compression coil spring 53 is attached to only the bolt 52, but the compression coil spring may be attached to the bolt 52 as well.

As described in the first embodiment, when switching to the hammer mode, the switching lever 8 is rotated to move the pin 7 from the position P1 shown in FIG. 3A to P2. As a result, the pin 7 presses the flange portion 5F of the second clutch 5 in the direction of the arrow 91, and the second clutch 5 moves against the elastic force of the spring 12 (see FIG. 4).

When the second clutch 5 moves in the direction of the arrow 91, the locking spline portion 5K formed on the outer periphery of the flange portion 5F of the second clutch 5
(See FIG. 6C). The engagement of the two causes the second clutch 5 to enter a locked state in which it cannot rotate.

As a result, unexpected rotation of the bit 24 during operation in the hammer mode can be reliably prevented, and work safety can be improved. The position of the lock plate 50 shown in FIGS. 6A and 6C (the position of the lock plate 50 that can mesh with the second clutch 5) is the reference position of the lock plate 50 in the present embodiment.

By the way, the rotation angle of the second clutch 5 about the intermediate shaft 2 is adjusted by the groove 50K of the lock plate 50.
May deviate from the meshing angle with respect to. If the lock plate 50 is fixed to the reference position shown in FIG. 6A when the two are not smoothly engaged with each other, the second clutch 5
It is blocked by 0 and cannot move in the arrow 91 direction.

In this embodiment, the lock plate 50 is movable in the direction of arrow 91 along the bolts 51 and 52.
Therefore, even when the rotation angle of the second clutch 5 is deviated from the meshing angle of the lock plate 50 with the groove 50K, as shown in FIG.
Is compressed, and the lock plate 50 allows the second clutch 5 to move.

Since the through holes formed in the lock plate 50 are formed slightly larger than the bolts 51 and 52, they receive the movement of the second clutch 5 as shown in FIG. Can be positioned obliquely with respect to.

Further, since the lock plate 50 is constantly urged in the direction of arrow 90 by the compression coil spring 53, the lock plate 50 immediately returns to the reference position when the shift of the meshing angle is eliminated, and the second clutch 5 Can be engaged. For example, from the state shown in FIG.
When the second clutch 5 slightly rotates due to the influence of the rotation of the intermediate shaft 2, vibration, or the like, the lock plate 50 immediately returns to the reference position shown in FIG. Mesh.

The other configuration of the hammer drill according to this embodiment is the same as that of the first embodiment.

[Third Embodiment] Next, a third embodiment of the rotary tool operation switching mechanism according to the present invention will be described with reference to FIGS. As in the first embodiment, the intermediate shaft 2 is provided with a first clutch 4 and a boss 3. Then, the first clutch 4 rotates by engaging with the intermediate shaft spline portion 2T, whereby the arm 17 transmits a striking operation to the bit 24.

In this embodiment, an intermediate shaft gear 30 is formed integrally with the intermediate shaft 2. The final gear 6 (rotation drive member) meshes with the intermediate shaft gear 30. As shown in FIG. 7, a steel ball 32 and a spring 33 are provided at the end of the intermediate shaft 2 to prevent the intermediate shaft 2 from rattling. In addition,
A bearing can be provided at the end of the intermediate shaft 2 as in the first embodiment, and the first embodiment can be provided with the steel ball 32 and the spring 33 in the present embodiment.

The tool holder 25 is provided with a tool holder spline portion 42 in which a gear holder 36 is formed.
The gear holder spline portion 40 is coupled, and the gear holder 36 is slidably held in the directions of arrows 90 and 91. The final gear 6 is rotatably provided on the gear holder 36 with the friction plate 35 interposed therebetween. The gear holder 36 is further provided with a nut 39 via a disc spring 37, and the final gear 6 is integrally rotated by friction with the gear holder 36. In addition, nut 39
Has a brake plate 31 fitted therein. The gear holder 36 is urged in the direction of arrow 90 by a spring 34.

FIG. 10 shows details of the brake plate 31. The brake plate 31 has a hole 45, which is shown in FIG.
The support shaft 46 shown in FIG. The support shaft 46 is fixed in the housing 10, and the brake plate 31 is movable along the support shaft 46 in the directions of arrows 90 and 91. 7 to 9, the support shaft 46 is not shown.

In this embodiment, a switching lever 43 is attached to the side of the housing 10. The switching lever 43 is provided with two first pins 43a and second pins 43b. The first pin 43a and the second
The pin 43b is a switching member in the present embodiment,
Both are provided side by side on a line passing through the rotation center of the switching lever 43 (FIGS. 7 to 10).

As shown in FIG. 10, the first pin 43a is longer than the second pin 43b and is located near the center of the switching lever 43. When the switching lever 43 is operated to rotate, as shown in FIG.
Abuts on the protruding piece 47 of the brake plate 31 and presses the brake plate 31 in the direction of arrow 91.

When the switching lever 43 is rotated from the position shown in FIG. 7 to the position shown in FIG.
3a contacts the first clutch 4 and presses the first clutch 4 in the direction of arrow 90. In this case, the second pin 43b is
Since it is provided shorter than the pin 43a, it does not come into contact with the first clutch 4.

As described above, the first pins 43a having different lengths are provided.
By providing the second pin 43b at a position different from the rotation center of the switching lever 43, the movement lengths of the brake plate 31 and the first clutch 4 can be controlled. The other mechanisms in the present embodiment are the same as those in the first embodiment.

Next, the mode switching operation in this embodiment will be described below. FIG. 7 shows a state of the hammer drill mode. In this case, the first clutch 4 is engaged with the intermediate shaft spline portion 2T of the intermediate shaft 2 (engaged state), and a striking operation is transmitted to the bit 24 via the boss 3 and the arm 17. The final gear 6 is meshed with the intermediate shaft gear 30 (engaged state), and a rotation operation is transmitted to the bit 24 via the tool holder 25. In this manner, the bit 24 operates in a hammer drill mode in which a hit is performed while rotating.

FIG. 8 shows a state of the hammer mode. When switching to the hammer mode, the switching lever 43 is rotated clockwise from the state shown in FIG. 7 to the state shown in FIG. As a result, the second pin 43b presses the brake plate 31 in the direction of arrow 91, and accordingly the entire gear holder 36 on which the final gear 6 is supported moves in the direction of arrow 91 against the elastic force of the spring 34.

As a result, the engagement between the final gear 6 and the intermediate shaft gear 30 is released (disengaged state), the rotation operation is not transmitted to the bit 24, and the bit 24 performs only the striking operation. Perform the operation. In this case, the final gear 6 meshes with the locking gear 41 serving as a locking member, and a locked state in which rotation is impossible. Thereby, the bit 24 can be prevented from rotating unexpectedly during the operation in the hammer mode, and work safety can be improved.

FIG. 9 shows the state of the drill mode.
When switching to the drill mode, the switching lever 43 is rotated counterclockwise from the state shown in FIG. 7 to the position shown in FIG. As a result, the first pin 43a
The clutch 4 is pressed, and the first clutch 4
Moves in the direction of arrow 90 against the elastic force of the spring 11.

By the movement of the first clutch 4, the engagement between the intermediate shaft spline portion 2T of the intermediate shaft 2 and the first clutch 4 is released (disengaged state).
4 is not transmitted as a hitting operation, the bit 24 performs only a rotation operation, and operates in a drill mode.

The final gear 6 is released from the intermediate shaft gear 30 by setting the rotation angle of the switching lever 43 at an intermediate position between the state shown in FIG. 7 and the state shown in FIG. The bit 24 can be positioned in a non-meshing state, and the angle of the bit 24 can be manually adjusted (chisel-free mode).

As described above, the mode is switched by rotating the switching lever 43 and moving the positions of the first pin 43a and the second pin 43b. here,
In the hammer drill mode shown in FIG. 7, the first pin 43a and the second pin 43b are connected to the brake plate 31, the first clutch 4
Do not touch any of

In the hammer mode shown in FIG. 8, the second pin 43b abuts on the brake plate 31, but the final gear 6 does not rotate because the engagement of the intermediate shaft 2 with the intermediate shaft gear 30 is released. It is in a state. In the drill mode shown in FIG. 9, the first pin 43a is
In this case as well, the first clutch 4 does not rotate since the engagement with the intermediate shaft spline portion 2T of the intermediate shaft 2 is released.

As described above, the first pin 43a and the second pin 4
3b is in contact with the non-rotating brake plate 31, so that it is not worn due to rotational contact, and the durability can be improved. Also, the first pin 43a, the second pin 43b and the brake plate 3
No fricative noise is generated. Furthermore, since the first pin 43a and the second pin 43b do not generate heat due to frictional heat, the switching lever 43 is not deformed due to the heat generation, and the work safety can be improved.

In the present embodiment, the first pin 43a is moved directly in contact with the first clutch 4, but it may be moved indirectly by contacting another member. Further, the second pin 43b is indirectly brought into contact with the final gear 6 via the brake plate 31 or the like and is moved.
You may make it contact the final gear 6 directly.

[Fourth Embodiment] Next, a fourth embodiment of the rotary tool operation switching mechanism according to the present invention will be described. In the present embodiment, the lock plate 50 described in the second embodiment is applied to the hammer drill described in the third embodiment. That is, a lock plate 50 (FIGS. 5 and 6) is provided (not shown) instead of the lock gear 41 (FIGS. 7 to 9) of the third embodiment. The lock plate 50 is formed with a gear groove that meshes with the final gear 6.

The lock plate 50 is supported by bolts 51 and 52, and the lock plate 50 is urged in the direction of arrow 90 by a compression coil spring 53 attached to the bolt 51 (see FIGS. 5 and 6). Thereby, even if the rotation angle of the final gear 6 is deviated from the meshing angle of the lock plate 50 with the gear groove,
The compression coil spring 53 is compressed, and the lock plate 50 allows the movement of the second clutch 5 (see FIG. 6B).

Further, since the lock plate 50 is constantly urged in the direction of the arrow 90 by the compression coil spring 53, the lock plate 50 immediately returns to the reference position when the deviation of the meshing angle is eliminated, and the lock gear 50 is connected to the final gear 6. Can be interlocked. For example, when the final gear 6 slightly rotates from the state shown in FIG. 6B due to the influence of the rotation of the intermediate shaft 2, vibration, or the like, the lock plate 50 immediately returns to the reference position under the urging of the compression coil spring 53 and returns to the final position. It meshes with the gear 6 (see FIG. 6C).

The other configuration of the hammer drill according to the present embodiment is the same as that of the third embodiment.

[Other Embodiments] The operation switching mechanism of the rotary tool according to the present invention is not limited to the above embodiments. That is, the switching member comes into direct or indirect contact with the first transmission member, moves the first transmission member from the engaged state to the released state, and the switching member directly or indirectly contacts the second transmission member. The first transmission member and the second transmission member are brought into contact with each other by moving the second transmission member to change the engagement state from the engagement state to the release state. Other configurations may be employed as long as both of the transmission members are in the engaged state.

Further, it is movable in the axial direction of the intermediate shaft,
The non-rotatable lock member engages with the second transmission member at the reference position when the second transmission member switches from the engaged state to the released state, and the urging member applies the lock member toward the reference position. Other configurations may be employed as long as they are active.

Further, the switching member directly or indirectly abuts the first transmission member, and the first transmission member is moved to change the engagement state to the released state, and the switching member is directly or indirectly contacted with the rotary drive member. The contact member is moved from the engaged state to the released state by moving the rotary drive member, and the switching member does not contact any of the first transmission member and the rotary drive member. Other configurations may be employed as long as both are engaged.

Further, it is movable in the axial direction of the intermediate shaft,
The non-rotatable lock member meshes with the rotary drive member at the reference position when the rotary drive member switches from the engaged state to the released state, and the biasing member biases the lock member toward the reference position. Other configurations can also be employed.

[Brief description of the drawings]

FIG. 1 is an overall side sectional view of a hammer drill showing a first embodiment of a rotary tool operation switching mechanism according to the present invention.

FIG. 2 is a detailed view of the vicinity of the intermediate shaft shown in FIG. 1, wherein A indicates a hammer mode, B indicates a hammer mode, and C indicates a drill mode.

FIG. 3 is a diagram showing details of a switching lever shown in FIG. 2;

FIG. 4 is a side sectional view of a hammer drill showing a second embodiment of the operation switching mechanism of the rotary tool according to the present invention.

FIG. 5 is a sectional view taken in the direction of arrows VV shown in FIG. 4;

6 is a sectional view taken along the line VI-VI shown in FIG.

FIG. 7 is a side cross-sectional view of a hammer drill showing a third embodiment of the operation switching mechanism of the rotary tool according to the present invention;
13 shows a hammer drill mode.

FIG. 8 is a side sectional view of a hammer drill showing a third embodiment of the operation switching mechanism of the rotary tool according to the present invention;
This shows the hammer mode.

FIG. 9 is a side sectional view of a hammer drill showing a third embodiment of the operation switching mechanism of the rotary tool according to the present invention;
Shows the drill mode.

FIG. 10 is a view showing details in the vicinity of the brake plate shown in FIGS. 7 to 9;

FIG. 11 is a diagram showing a first conventional example, in which A indicates a drill mode, B indicates a hammer drill mode, and C indicates a hammer mode.

FIG. 12 is a diagram showing a clutch moving mechanism in the first conventional example shown in FIG. 11;

FIG. 13 is a diagram showing a second conventional example.

FIG. 14 is a view showing details of the clutch shown in FIG. 13;

[Explanation of symbols]

 2 ····· Intermediate shaft 3 ······ Boss 4 ····· First clutch 5 ······ Second clutch 6 ····· Final gear 7 ···· Pin 8 43 switching lever 13, 41 locking gear 15 motor 17 arm 31 braking plate 43a first pin 43b ... second pin 50 ... lock plate 53 ... compression coil spring

Claims (4)

(57) [Claims] An intermediate shaft which is attached to the intermediate shaft and rotates in response to the driving of the drive unit, and is engaged with the intermediate shaft so as to rotate along with the intermediate shaft by moving in the axial direction of the intermediate shaft; A first transmission member located in a released state in which it is rotatable with respect to the intermediate shaft; an engagement state in which the first transmission member is attached to the intermediate shaft and rotates with the intermediate shaft by moving in the axial direction of the intermediate shaft; A second transmission member that is positioned in a released state where the second transmission member is rotatable with respect to the first transmission member, and converts a rotation operation into a percussion operation and transmits it to a tool portion; A rotation drive member that rotates with the rotation and transmits the rotation operation to the tool portion; and a switching member that directly or indirectly abuts on one of the first transmission member and the second transmission member. Direct to the first transmission member The switching member contacts the second transmission member directly or indirectly to move the second transmission member by contacting or indirectly contacting the first transmission member to move the first transmission member from the engaged state to the release state. In this way, the state is changed from the engaged state to the released state, and the switching member does not come into contact with any of the first transmitting member and the second transmitting member, so that both the first transmitting member and the second transmitting member are brought into the engaged state. An operation switching mechanism for a rotary tool. 2. The operation switching mechanism for a rotary tool according to claim 1, wherein said lock member is movable in the axial direction of said intermediate shaft and is not rotatable, and said second transmission member is moved from an engaged state. An operation switching mechanism for a rotary tool, comprising: a lock member that meshes with the second transmission member at a reference position when the state is switched to the release state; and a biasing member that biases the lock member toward the reference position. . 3. An intermediate shaft having an engaging portion, which rotates in response to the drive of the driving portion, is attached to the intermediate shaft, and is rotated along with the intermediate shaft by moving in the axial direction of the intermediate shaft. A first transmission member positioned in an engaged state or in a released state in which the first transmission member is rotatable with respect to the intermediate shaft; A rotating drive member that is positioned in an engaged state that rotates with the engaging portion of the intermediate shaft or in a released state that is rotatable with respect to the engaging portion of the intermediate shaft, the tool being located in the engaged state; A rotation driving member that transmits a rotation operation to the unit, a switching member that directly or indirectly abuts on either the first transmission member or the rotation driving member, wherein the switching member is directly or in contact with the first transmission member. Indirect contact, the first transmission The switching member is brought into the released state from the engaged state by moving the material, and the switching member abuts directly or indirectly on the rotary drive member, and the rotary drive member is moved from the engaged state to the release state. The operation switching mechanism of a rotary tool, wherein both the first transmission member and the rotation driving member are engaged by not contacting either the first transmission member or the rotation driving member. 4. The rotary tool operation switching mechanism according to claim 3, wherein the rotary drive member is switched between an engaged state and a released state by moving in the axial direction of the rotary shaft. A lock member movable in the direction and non-rotatable, wherein the lock member meshes with the rotary drive member at the reference position when the rotary drive member switches from the engaged state to the released state. A biasing member for biasing the rotary tool toward a position;