JP2001009746A - Rotary impact tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotary impact tool that can not only stop impact functions easily but also change the rotating speed of its spindle to a corresponding lower side automatically, when used as a boring drill. SOLUTION: This rotary impact tool comprises an impact stoppage mechanism for restraining the back movement of a hammer 70 to check any impact of the hammer 70 against an anvil 71, and a transmission mechanism 55 for changing the rotating speed of a spindle 73 between a high speed and a lower one. A switching operation by a changeover switch 60 changes both impact stoppage mechanism and transmission mechanism 55 over in synchronous fashion.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary impact tool called, for example, an impact wrench or an impact driver.

[0002]

2. Description of the Related Art Conventionally, this kind of tool has been used not only for fastening bolts and screws but also frequently for drilling wood. Nevertheless, if a hammer is hit, the hitting sound is noisy and not only the worker but also the surrounding noise becomes a problem. Therefore, in recent years, a rotary impact tool having a configuration for adding a mechanism for stopping a hammer from hitting has been developed, such as that disclosed in Japanese Patent Application Laid-Open No. 2-139182.

[0003] This conventional impact stopping mechanism is disclosed in
It was configured as shown in FIG. That is, an annular concave groove 101 extending over the entire circumference is provided on the outer peripheral surface of the hammer 100, while a cam groove 104 inclined with respect to the axial direction of the spindle 102 is provided on the gear case 103, and the gear case 103 is formed through the cam groove 104. The distal end of the engagement pin 106 protruding inward from the ring-shaped operation handle 105 disposed on the outer peripheral surface is inserted into the concave groove 1.
01. According to this configuration, the operating handle 105 is rotated to move the engagement pin 106 along the cam groove 104, and the engagement pin 10
6 is brought into contact with the side wall on the front side (right side in the figure) of the concave groove 101, so that the hammer 100 can be kept in a state in which the hammer 100 cannot be retracted and is always engaged with the anvil 107. 100 anvils 10
7 could be stopped. Conversely, by rotating the operation handle 105 in the opposite direction, the engagement pin 106
Is moved to the rear side (the left side in the figure) (the state shown in the figure), the hammer 100 can be retracted, so that the operation of applying a rotational impact to the anvil 107 is allowed. Was.

[0004]

However, there has been a conventional rotary impact tool provided with a hitting stop mechanism as described above. However, a hitting possible state and a hitting stop state, that is, the rotary impact tool is not used. The spindle 102 is used in accordance with a case where the spindle 102 is used as an original rotary impact tool and a case where it is used as a simple drill for drilling holes in wood or the like.
Consequently, the rotation speed of the hammer 100 (or the anvil 107) could not be switched.

Here, in general, when the spindle is used as an original rotary impact tool, it is necessary to rotate the spindle at a high rotation speed of about 2000 rpm or more. If the drill is stopped and used as a simple drill, there is a problem that the torque becomes insufficient and a large load is applied to the motor. Therefore, when using this rotary impact tool as a mere drill, it is preferable to change the rotation speed of the spindle to a low rotation speed of about 1000 rpm or less. In this regard, none of the conventional rotary impact tools disclosed in the above publications has a speed change mechanism capable of easily switching the number of revolutions according to the purpose of use, and is not necessarily a practical one in actual use. I couldn't say.

SUMMARY OF THE INVENTION The present invention has been made in view of this problem, and can easily switch the operation or stop of the striking function according to the purpose of use, such as use as an original rotary impact tool or as a simple drill. It is another object of the present invention to provide a rotary impact tool that can easily switch the number of revolutions of the spindle and, consequently, the tool according to the work purpose.

[0007]

Therefore, the present invention provides a hitting stop mechanism for restricting the hammer from retreating to prevent the hammer from hitting the anvil, and a speed change mechanism for switching the rotational speed of the spindle between high speed and low speed. It is characterized by having.

[0008]

According to the above construction, when the rotary impact tool is used as the original rotary impact tool, the impact stop mechanism is released to enable the hammer to retreat, and the transmission mechanism is switched to the high speed side to switch the spindle. Is rotated at a high speed. Accordingly, when the torque required to rotate the object to be tightened becomes larger than the torque of the spindle, the hammer retreats against the urging force of the spring, and at the moment when the engagement with the anvil is released, the urging force of the spring is released. In addition, the anvil moves forward while rotating due to rotational inertia, and gives a rotational impact to the anvil.

On the other hand, when this rotary impact tool is used as a simple drill, the hammer cannot be moved backward by operating the impact stop mechanism, and the spindle is rotated at a low speed by switching the speed change mechanism to the low speed side. State. Thus, the hammer does not hit the anvil and is always engaged, and the spindle rotates at a low speed, so that the rotational torque of the hammer and the anvil increases. Therefore, the drilling operation can be performed without generating a hitting sound and without applying a large load to the motor.

[0010]

1 to 8 show a first embodiment of the present invention.
It will be described based on. FIG. 1 shows a case where the rotary impact tool 1 of this embodiment is in a hitting stopped state, and FIG. 2 shows a case where the hitting is possible.

A motor 3 is built in a rear portion (right end in the figure) of the housing 2. A planetary gear mechanism 4 is mounted on the output shaft of the motor 3, and a transmission mechanism 5 is meshed with the planetary gear mechanism 4. The transmission mechanism 5 is mounted on an intermediate shaft 7 that is supported in a rotatable manner in parallel with the output shaft of the motor 3. A gear 7a is formed at the left end of the intermediate shaft 7 in the figure, and a gear 8 attached to the rear end (the right end in the figure) of the spindle 6 meshes with the gear 7a. The spindle 6 has bearings 9a, 9
b, it is rotatably supported substantially coaxially with the output shaft of the motor 3, and its tip (the left end in the figure) extends into an impact case 10 rotatably attached to the tip of the housing 2. The impact case 10 is a cap-shaped case attached to the tip of the housing 2 and is attached to the housing 2 so as to be rotatable around the axis of the spindle 6. Is secured. As described above, the rotational force of the motor 3 is transmitted to the spindle 6 via the planetary gear mechanism 4 and the speed change mechanism 5. The configuration of the transmission mechanism 5 will be described later.

An anvil 1 is provided at the tip of the spindle 6.
1 is rotatably supported, and the anvil 11 protrudes from the tip of the impact case 10. The sealing property between the anvil 11 and the impact case 10 is also sufficiently ensured. On the other hand, a ring-shaped hammer 12 is mounted on the large diameter portion of the spindle 6 on the rear side (right side in the figure) of the anvil 11 so as to be rotatable and movable in the axial direction. Hitting portion 1 for transmitting rotational force by engaging unevenly with anvil 11
2a is formed. On the inner circumferential surface of the hammer 12, grooves 12b are formed at appropriate positions in the circumferential direction along the axial direction, while at appropriate positions in the circumferential direction of the large diameter portion of the spindle 6 in the axial direction. An inclined groove 6a is formed, and the two grooves 12b and 6a are paired and a steel ball 13 is sandwiched between them. The hammer 12 is connected to the spindle 6 for rotation about an axis by the steel ball 13.

A stepped washer 14 is mounted on the back side (right side in the figure) of the hammer 12, and a spring 15 is mounted between the stepped washer 14 and the hammer 12. The hammer 12 is formed by the spring 15.
Is biased toward the anvil 11 side.

An adjusting member 18 is mounted on the back side of the stepped washer 14 so as to be rotatable around the spindle 6 and movable in the axial direction with a thrust bearing 16 and a collar 17 interposed therebetween. This adjusting member 18
As shown in FIGS. 3 and 4, arms 19, 19 are provided on the outer periphery of a circular substrate having a hole 18a through which the spindle 6 is inserted at the center.
On the opposite side, the adjusting claws 20, 20 are provided to face each other.

At the tip of the arm 19, a locking claw 19a which is folded back toward the outer periphery in the diameter direction is formed so as to protrude. The locking claw 19a is formed inside the impact case 10 as shown in FIG. 1 or FIG. Each is fitted into a groove 10a formed on the peripheral surface. Thus, the adjustment member 18 rotates around the axis of the spindle 6 by rotating the impact case 10.

The tip of the adjusting claw 20 is formed in a semicircular shape.
2 butted against the bottom surface 22a. The adjustment ring 21 is fixed between the outer ring of the bearing 9 b supporting the spindle 6 and the housing 2 so as not to rotate and not move in the axial direction. On the left side of the adjustment ring 21 in the figure,
As shown in FIG. 6, the groove 22 is formed over the entire circumference, and the bottom surface 22a of the groove 22 is formed so as to be inclined every half circumference as shown in FIG. When the adjusting member 18 is rotated with the adjusting claw 20 abutting against the bottom surface 22a formed in this way, the adjusting claw 20 is
2a so that the adjusting member 1
8 moves in the axial direction. A concave groove 22c having a semicircular cross section is formed at a constant interval on the bottom surface 22a. The rotation of the adjusting member 18 is locked by fitting the tip of the adjusting claw 20 into the concave groove 22c. Axial movement is locked.

The hitting stop mechanism in this embodiment is constituted by using the adjusting member 18 and the adjusting ring 21 described above as main members, and the hitting stop mechanism is incorporated in the impact mechanism in the impact case 10. And
When the adjusting member 18 is rotated by rotating the impact case 10, the adjusting member 18 is rotated.
Moves in the axial direction, whereby the amount of compression of the spring 15 is adjusted, and the impact of the hammer 12 is stopped by increasing the amount of compression to a state where the hammer 12 cannot be retracted (the state of FIG. 1). It has become.

Although not shown in the drawings, the housing 2 and the impact case 10 are provided with scales for indicating the amount of rotation of the impact case 10, that is, the relative position of the adjustment member 18 with respect to the adjustment ring 21.
The operator can know the position of the adjusting member 18 through this scale, that is, whether the hammer 12 is in a hittable state or in a stopped state.

Next, the transmission mechanism 5 will be described. A large gear 30 and a small gear 31 are supported on the intermediate shaft 7 so as to be rotatable and movable in the axial direction, respectively. Bearings 34, which support the rear sides of the two gears 30, 31 and the intermediate shaft 7,
Between them, springs 32, 32 are mounted to urge both gears 30, 31 in a direction approaching each other.

A boss 36 having cut grooves 36a, 36a facing each other is formed on the opposing surfaces of both gears 30, 31, and a distance collar 38 is hung on the outer peripheral side of both bosses 36, 36. It is attached as a handbook. A groove 38a is formed over the entire outer peripheral surface of the distance collar 38, and the tip of a switching arm 39 is fitted into the groove 38a as shown in FIG. At the rear end of the switching arm 39, the housing 2 is slidably movable in a direction orthogonal to the plane of FIG.
Is connected to the slide switch 40 supported by
The slide switch 40 is slidable from outside the housing 2.

On the other hand, the boss portions 3 of the two gears 30, 31
6 and 36, a pin 37 is diametrically attached to the intermediate shaft 7.
, And both ends of the pin 37 protrude from the peripheral surface of the intermediate shaft 7 as shown in FIG.

When the slide switch 40 is operated from this configuration, the two gears 30 and 31 move integrally on the intermediate shaft 7 leftward or rightward in FIG. 1 by the urging force of the springs 32 and 32. As a result, the protruding portion of the pin 37 is connected to the large gear 30 or the small gear 3.
When the large gear 30 or the small gear 31 is fitted into the cut groove 36a of the first boss portion 36, the large gear 30 or the small gear 31 is connected to the intermediate shaft 7 for rotation. As shown in FIG. 8, a leaf spring 41 is interposed in a sliding portion between the switching arm 39 and the housing 2 so that a slide switch 40 is provided.
Moderate (about overcoming the biasing force of the spring 32)
Sliding resistance is given, and the switching position of both gears 30, 31 is maintained.

The rotary impact tool 1 of the present embodiment configured as described above is used as follows. First, this tool 1
In order to use as a rotary impact tool for the purpose of screw tightening or the like from the impact stop state shown in FIG. 1 to the hittable state shown in FIG. 2, the impact case 10 may be rotated to the impact side of the scale display. Thereby, the adjusting member 1
8 also rotates, and its adjusting claw 20 is inserted into the groove 2 of the adjusting ring 21.
The adjusting member 18 is moved rearward (to the right in the drawing) by the spring 15. As shown in FIG.
2, the adjusting member 18 reaches the retreating end, and this state is the state where the amount of compression of the spring 15 is the smallest, and therefore the state in which the hammer 12 can retreat with the lightest force, that is, the striking force of the hammer 12 is the most. It becomes a small state. Here, if the amount of rotation of the impact case 10 is made smaller than the above, the amount of compression of the spring 15 increases, and the impact force of the hammer 12 can be increased. As described above, by adjusting the rotation amount of the impact case 10, that is, the position of the adjustment member 18, the impact force of the hammer 12 can be adjusted.

Next, the speed change mechanism 5 is switched to the high speed side.
This is because the slide switch 40 is slid to the left in FIG.
6a. As a result, the small gear 31 is connected to the intermediate shaft 7 for rotation, the rotational force of the motor 3 is transmitted to the spindle 6 via the small gear 31, and the rotation speed of the motor 3 is increased by the small gear 31, so that the 6
Rotates at high speed. In this case, the large gear 30 idles on the intermediate shaft 7.

As described above, the switching to the hittable state is completed by retracting the adjusting member 18 and switching the transmission mechanism 5 to the high speed side. If the motor is rotated by operating the trigger in the hittable state, the tool 1 can be used as a rotary impact tool. The operation as this rotary impact tool is conventional and will not be described in detail.

Next, a case where the tool 1 is used simply as a drill for the purpose of drilling wood, for example, will be described. In this case, the impact case 10 may be rotated in the opposite direction, whereby the adjusting member 18 also rotates, and the adjusting claw 20 moves the groove 22 of the adjusting ring 21 in a shallow direction. 18 moves forward against the spring 15. Thereby, the spring 15 is finally compressed to a position where the hammer 12 cannot be retracted (the state of FIG. 1). As a result, the hammer 12 is pressed against the anvil 11 and is always engaged, so that the hammer 12 is not hit.

Further, the speed change mechanism 5 is switched to the low speed side. That is, the slide switch 40 is slid rightward in FIG. 1, and the pin 37 is fitted into the cut groove 36a on the large gear 30 side. As a result, the large gear 30 is rotationally connected to the intermediate shaft 7, so that the torque of the motor 3 is transmitted to the spindle 6 via the large gear 30. Further, in this case, the rotation speed of the motor 3 is reduced by the large gear 30, so that the spindle 6 rotates at a low speed.

As described above, the anvil 11 is connected to the hammer 12
The tool 1 can be rotated with a high torque without being hit by the tool 1, and the tool 1 can be used in a good state as a drill.

As described above, the rotary impact tool 1 of the present embodiment has a structure in which the hammer 12 has a striking stop mechanism and the speed change mechanism 5, so that the rotary impact tool 1 is in a good state as the conventional rotary impact tool. Of course, you can use
Even when used as a simple drill, the tool (drill) can be rotated with a high torque without overloading the motor 3, and the hammer 12 can be used in a state where the hammer 12 is reliably stopped.

In the hitting stop mechanism, since the hammer 100 is conventionally prevented from retreating by the engagement pin 106, a large force is applied to the engagement pin 106 and the gear case 103 supporting the same. As a result, the strength of the tool and the durability of the tool are problematic. However, the hitting stop mechanism of this embodiment slides the adjusting member 18 to move the spring 1.
Since the retraction of the hammer 12 is regulated by adjusting the compression amount of the hammer 100, the impact of the hammer 12 can be more easily and reliably performed than in the conventional configuration in which the retraction of the hammer 100 is directly restricted by the engagement pin 106. It can be stopped, thus eliminating the conventional strength problems.

Further, in the conventional configuration, the gear case 103
Since the cam groove 104 is formed in the hole, there is a problem that oil leaks or foreign matter enters the impact mechanism through the cam groove 104. However, according to the configuration of this example, the engagement pin 106
It is not necessary to provide the cam groove 104 as in the case of (1), so that the sealing performance of the tool does not deteriorate.

Next, a second embodiment of the present invention will be described with reference to FIG. In the first embodiment described above, the hammer 12
Although the hitting stop mechanism and the speed change mechanism 5 have been described as being operated independently of each other, a configuration in which both mechanisms are linked and one-touch switching is possible as described below.

FIG. 9 shows a rotary impact tool 50 in which the two mechanisms are linked. In the following second embodiment, an angle type in which the spindle is disposed at right angles to the output shaft of the motor will be described as an example.

A motor 52 is built in the housing 51, and its output shaft is connected to a planetary gear mechanism 53.
An intermediate shaft 54 is rotatably supported in parallel with the output shaft of the motor 52, and a speed change mechanism 55 is attached to the intermediate shaft 54. The speed change mechanism 55 has a large gear 56 and a small gear 57 similarly to the speed change mechanism 5 in the first embodiment, and each has a boss portion formed with a notch groove. A distance collar 58 is attached to the outer peripheral sides of the two boss portions in a bridging manner, and the distance between the two gears 56 and 57 is maintained at a constant distance. Pins 59 are attached to the intermediate shaft 54 between the two bosses in the same manner as in the first embodiment, with both ends protruding from the peripheral surface of the intermediate shaft 54. Also, both gears 5
A spring is mounted on the back side of each of the members 6 and 57 and is urged in a direction to approach each other.

On the other hand, a changeover switch 60 is rotatably mounted on the housing 51 below the gears 56 and 57 in the drawing, and a changeover flange 61 is formed integrally with the changeover switch 60. When the changeover switch 61 is rotated to a fixed position, the changeover flange 61 is located behind the hammer 70 (upper part in the figure) as illustrated.
To the hammer 70 and rotate it 180 °.
The switch 60 is formed eccentrically so as to retreat from behind. Therefore, the changeover switch 60
Is rotated so that the switching flange 61 is extended to the rear of the hammer 70, the retraction of the hammer 70 is prevented, whereby the hitting operation on the anvil 71 can be stopped. When the changeover switch 60 is rotated by 180 ° from the impact stop position, the changeover flange 61 is retreated from behind the hammer 70 and the hammer 70
Can be retracted, so that the stoppage of hammering of the hammer 70 is released.

Further, a switching pin 62 is formed on the inner side surface (upper surface in the drawing) of the switching flange 61 so as to protrude inward. The switching pin 62 is located at a position eccentric to the rotation center of the changeover switch 60 by a certain distance as shown in the figure, and on the side opposite to the projecting side of the switching flange 61, between the large gear 56 and the small gear 57. It is formed so as to protrude. As a result, when the changeover switch 60 is rotated to bring the changeover flange 61 to the rear of the hammer 70, that is, the hammer 70 stops hitting (the state shown in the figure), the changeover pin 62 is moved more than the center of rotation of the changeover switch 60. The gears 56 and 57 are slid rightward in the drawing by moving to the right, whereby the large gear 56 is connected to the intermediate shaft 54 for rotation, and the transmission mechanism 55 is switched to the low speed side.

On the other hand, when the changeover switch 60 is turned 180 ° from the above-described hitting stop state and the changeover flange 61 is retracted from behind the hammer 70, that is, the changeover pin 62 is turned on. 60 to the left of the center of rotation of the
6 and 57 are slid to the left in the figure, whereby the small gear 57 side is connected to the intermediate shaft 54 for rotation, and the transmission mechanism 55 is switched to the high speed side.

The intermediate shaft 54 passes through a bevel gear 72,
The intermediate shaft 54 is rotatably connected to a spindle 73 disposed at right angles to the spindle 73, and a hammer 70 is attached to the spindle 73 via a steel ball 74 so as to be rotatable and movable in the axial direction. The spring 75 urges the spindle 73 toward the anvil 71 rotatably supported by the tip of the spindle 73.

According to the above configuration, when the rotary impact tool 50 is used as a simple drill, it is sufficient to simply rotate the changeover switch 60 to the side where the impact is stopped. That is,
When the changeover switch 60 is rotated to the side where the impact is stopped, the changeover flange 61 is switched to the side protruding rearward of the hammer 70, and at the same time, the transmission mechanism 55 is switched to the lower speed side. When the switch is used as an original rotary impact tool, the changeover switch 60 is set at about 180 degrees from the impact stop side.
, The switching flange 61 retreats from behind the hammer 70, and at the same time, the transmission mechanism 55 switches to the high-speed side.

As described above, according to the rotary impact tool 50 of the second embodiment, only by operating the changeover switch 60, the hammer 70 can be switched between hitting stop or canceling, and the spindle 73 can be switched between low speed rotation and high speed rotation. Therefore, as described in the first embodiment, not only can the rotary impact tool function well as a mere drill, but also a more convenient rotary impact tool can be provided.

[0041]

According to the present invention, the hammer can be stopped and the rotation of the spindle can be switched to the low-speed rotation. Therefore, even when the rotary impact tool is simply used as a drill, an overload is applied to the motor. The tool can be rotated with high torque without application, and thus the rotary impact tool can be made sufficiently practical as a drill.

[Brief description of the drawings]

FIG. 1 is a partially broken side view of a rotary impact tool in a hit stop state and a low-speed rotation state according to a first embodiment of the present invention.

FIG. 2 is a partially broken side view of the rotary impact tool in a hittable state and in a high-speed rotation state.

FIG. 3 is a side view of an adjustment member.

FIG. 4 is a plan view of an adjustment member.

FIG. 5 is a sectional view taken along line BB of FIG. 2;

FIG. 6 is a plan view of an adjustment ring.

FIG. 7 is a development view of a half circumference of a groove of the adjustment ring.

FIG. 8 is a sectional view taken along line AA of FIG. 1;

FIG. 9 is a longitudinal sectional view of an angle type rotary impact tool according to a second embodiment of the present invention.

FIG. 10 is a vertical cross-sectional view illustrating a conventional impact stopping mechanism.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Rotation impact tool 2 ... Housing 3 ... Motor 5 ... Transmission mechanism 6 ... Spindle 10 ... Impact case 11 ... Anvil 12 ... Hammer 18 ... Adjustment member 21 ... Adjustment ring 40 ... Slide switch 50 ... Rotation impact tool (angle type) 55 ... Transmission mechanism 60 ... Changeover switch 61 ... Changeover flange 62 ... Changeover pin 100 ... Hammer, 101 ... Concave groove 104 ... Cam groove, 105 ... Operation handle, 106 ... Engagement pin

[Procedure amendment]

[Submission date] July 6, 2000 (200.7.6)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Full text

[Correction method] Change

[Correction contents]

[Document Name] Statement

[Title of the Invention] Rotary impact tool

[Claims]

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary impact tool called, for example, an impact wrench or an impact driver.

[0002]

2. Description of the Related Art Conventionally, this kind of tool has been used not only for fastening bolts and screws but also frequently for drilling wood. Nevertheless, if a hammer is hit, the hitting sound is noisy and not only the worker but also the surrounding noise becomes a problem. Therefore, in recent years, a rotary impact tool having a configuration for adding a mechanism for stopping a hammer from hitting has been developed, such as that disclosed in Japanese Patent Application Laid-Open No. 2-139182.

[0003] This conventional impact stopping mechanism is disclosed in
It was configured as shown in FIG. That is, an annular concave groove 101 extending over the entire circumference is provided on the outer peripheral surface of the hammer 100, while a cam groove 104 inclined with respect to the axial direction of the spindle 102 is provided on the gear case 103, and the gear case 103 is formed through the cam groove 104. The distal end of the engagement pin 106 protruding inward from the ring-shaped operation handle 105 disposed on the outer peripheral surface is inserted into the concave groove 1.
01. According to this configuration, the operating handle 105 is rotated to move the engagement pin 106 along the cam groove 104, and the engagement pin 10
6 is brought into contact with the side wall on the front side (right side in the figure) of the concave groove 101, so that the hammer 100 can be kept in a state in which the hammer 100 cannot be retracted and is always engaged with the anvil 107. 100 anvils 10
7 could be stopped. Conversely, by rotating the operation handle 105 in the opposite direction, the engagement pin 106
Is moved to the rear side (the left side in the figure) (the state shown in the figure), the hammer 100 can be retracted, so that the operation of applying a rotational impact to the anvil 107 is allowed. Was.

[0004]

However, there has been a conventional rotary impact tool provided with a hitting stop mechanism as described above. However, a hitting possible state and a hitting stop state, that is, the rotary impact tool is not used. The spindle 102 is used in accordance with a case where the spindle 102 is used as an original rotary impact tool and a case where it is used as a simple drill for drilling holes in wood or the like.
Consequently, the rotation speed of the hammer 100 (or the anvil 107) could not be switched.

Here, in general, when the spindle is used as an original rotary impact tool, it is necessary to rotate the spindle at a high rotation speed of about 2000 rpm or more. If the drill is stopped and used as a simple drill, there is a problem that the torque becomes insufficient and a large load is applied to the motor. Therefore, when using this rotary impact tool as a mere drill, it is preferable to change the rotation speed of the spindle to a low rotation speed of about 1000 rpm or less. In this regard, none of the conventional rotary impact tools disclosed in the above publications has a speed change mechanism capable of easily switching the number of revolutions according to the purpose of use, and is not necessarily a practical one in actual use. I couldn't say.

SUMMARY OF THE INVENTION The present invention has been made in view of this problem, and can easily switch the operation or stop of the striking function according to the purpose of use, such as use as an original rotary impact tool or as a simple drill. It is another object of the present invention to provide a rotary impact tool that can easily switch the number of revolutions of the spindle and, consequently, the tool according to the work purpose.

[0007]

SUMMARY OF THE INVENTION Accordingly, the present invention provides
The rotary impact tool having the configuration described in each claim was used. Claim
According to the rotary impact tool described in 1, the impact can be stopped or the impact can be performed.
To change the spindle speed according to the operating state
Can be used, making it a simple drill
Can be used in good condition. Only
Also switching operation of the impact stop mechanism and switching of the transmission mechanism
The operation is performed in conjunction with the operation of the changeover switch
Therefore, compared to a configuration in which both mechanisms are switched separately,
You can improve your selfishness.

According to the rotary impact tool of the second aspect, when the rotary impact tool is used as the original rotary impact tool, the impact stop mechanism is released to enable the hammer to retreat, and the transmission mechanism is operated. Switch to the high-speed side to make the spindle rotate at high speed. Accordingly, when the torque required to rotate the object to be tightened becomes larger than the torque of the spindle, the hammer retreats against the urging force of the spring, and at the moment when the engagement with the anvil is released, the urging force of the spring is released. In addition, the anvil moves forward while rotating due to rotational inertia, and gives a rotational impact to the anvil. Off to release the impact stop mechanism
Switching operation and switching operation of the transmission mechanism to the high-speed side are switched off.
Interlocking by operating the switch
Done.

On the other hand, when this rotary impact tool is used as a simple drill, the hammer cannot be moved backward by operating the impact stop mechanism, and the spindle is rotated at a low speed by switching the speed change mechanism to the low speed side. State. Thus, the hammer does not hit the anvil and is always engaged, and the spindle rotates at a low speed, so that the rotational torque of the hammer and the anvil increases. Therefore, the drilling operation can be performed without generating a hitting sound and without applying a large load to the motor. Also in this case, the impact stop side of the impact stop mechanism
To the low-speed side of the transmission mechanism.
Operation is not linked with the changeover switch operation.
Is done. Thus, according to the rotary impact tool of claim 2,
If the impact stop mechanism is switched to the impact stop state,
By switching to the low speed side, it is good as a simple drill
It can be used in good condition,
Switch to a state where shooting is possible and switch the transmission mechanism to the high-speed side
In this way, it can be used in a good condition
And the above-mentioned impact stop mechanism and transmission mechanism
Is changed by the changeover operation of the changeover switch.
Since the rotation impact tool is used in conjunction with
Can be further improved.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Next, the invention (related to the invention) related to the present invention will be described.
The invention will be described with reference to FIGS. Figure 1
FIG. 2 shows a case where the rotary impact tool 1 according to the related invention is in a hitting stopped state, and FIG. 2 shows a case where the hitting is possible.

A motor 3 is built in a rear portion (right end in the figure) of the housing 2. A planetary gear mechanism 4 is mounted on the output shaft of the motor 3, and a transmission mechanism 5 is meshed with the planetary gear mechanism 4. The transmission mechanism 5 is mounted on an intermediate shaft 7 that is supported in a rotatable manner in parallel with the output shaft of the motor 3. A gear 7a is formed at the left end of the intermediate shaft 7 in the figure, and a gear 8 attached to the rear end (the right end in the figure) of the spindle 6 meshes with the gear 7a. The spindle 6 has bearings 9a, 9
b, it is rotatably supported substantially coaxially with the output shaft of the motor 3, and its tip (the left end in the figure) extends into an impact case 10 rotatably attached to the tip of the housing 2. The impact case 10 is a cap-shaped case attached to the tip of the housing 2 and is attached to the housing 2 so as to be rotatable around the axis of the spindle 6. Is secured. As described above, the rotational force of the motor 3 is transmitted to the spindle 6 via the planetary gear mechanism 4 and the speed change mechanism 5. The configuration of the transmission mechanism 5 will be described later.

An anvil 1 is provided at the tip of the spindle 6.
1 is rotatably supported, and the anvil 11 protrudes from the tip of the impact case 10. The sealing property between the anvil 11 and the impact case 10 is also sufficiently ensured. On the other hand, a ring-shaped hammer 12 is mounted on the large diameter portion of the spindle 6 on the rear side (right side in the figure) of the anvil 11 so as to be rotatable and movable in the axial direction. Hitting portion 1 for transmitting rotational force by engaging unevenly with anvil 11
2a is formed. On the inner circumferential surface of the hammer 12, grooves 12b are formed at appropriate positions in the circumferential direction along the axial direction, while at appropriate positions in the circumferential direction of the large diameter portion of the spindle 6 in the axial direction. An inclined groove 6a is formed, and the two grooves 12b and 6a are paired and a steel ball 13 is sandwiched between them. The hammer 12 is connected to the spindle 6 for rotation about an axis by the steel ball 13.

A stepped washer 14 is mounted on the back side (right side in the figure) of the hammer 12, and a spring 15 is mounted between the stepped washer 14 and the hammer 12. The hammer 12 is formed by the spring 15.
Is biased toward the anvil 11 side.

An adjusting member 18 is mounted on the back side of the stepped washer 14 so as to be rotatable around the spindle 6 and movable in the axial direction with a thrust bearing 16 and a collar 17 interposed therebetween. This adjusting member 18
As shown in FIGS. 3 and 4, arms 19, 19 are provided on the outer periphery of a circular substrate having a hole 18a through which the spindle 6 is inserted at the center.
On the opposite side, the adjusting claws 20, 20 are provided to face each other.

At the tip of the arm 19, a locking claw 19a which is folded back toward the outer periphery in the diameter direction is formed so as to protrude. The locking claw 19a is formed inside the impact case 10 as shown in FIG. 1 or FIG. Each is fitted into a groove 10a formed on the peripheral surface. Thus, the adjustment member 18 rotates around the axis of the spindle 6 by rotating the impact case 10.

The tip of the adjusting claw 20 is formed in a semicircular shape.
2 butted against the bottom surface 22a. The adjustment ring 21 is fixed between the outer ring of the bearing 9 b supporting the spindle 6 and the housing 2 so as not to rotate and not move in the axial direction. On the left side of the adjustment ring 21 in the figure,
As shown in FIG. 6, the groove 22 is formed over the entire circumference, and the bottom surface 22a of the groove 22 is formed so as to be inclined every half circumference as shown in FIG. When the adjusting member 18 is rotated with the adjusting claw 20 abutting against the bottom surface 22a formed in this way, the adjusting claw 20 is
2a so that the adjusting member 1
8 moves in the axial direction. A concave groove 22c having a semicircular cross section is formed at a constant interval on the bottom surface 22a. The rotation of the adjusting member 18 is locked by fitting the tip of the adjusting claw 20 into the concave groove 22c. Axial movement is locked.

The hitting stop mechanism of the related invention is constituted by using the adjusting member 18 and the adjusting ring 21 described above as main members, and the hitting stop mechanism is incorporated in the impact mechanism in the impact case 10. When the adjusting member 18 is rotated by rotating the impact case 10, the adjusting member 18 moves in the axial direction, whereby the amount of compression of the spring 15 is adjusted, and the amount of compression of the spring 15 is maximized.
Is set to a state in which the hammer 12 cannot retreat (the state shown in FIG. 1), thereby stopping the hammer 12 from hitting.

Although not shown in the drawings, the housing 2 and the impact case 10 are provided with scales for indicating the amount of rotation of the impact case 10, that is, the relative position of the adjustment member 18 with respect to the adjustment ring 21.
The operator can know the position of the adjusting member 18 through this scale, that is, whether the hammer 12 is in a hittable state or in a stopped state.

Next, the transmission mechanism 5 will be described. A large gear 30 and a small gear 31 are supported on the intermediate shaft 7 so as to be rotatable and movable in the axial direction, respectively. Bearings 34, which support the rear sides of the two gears 30, 31 and the intermediate shaft 7,
Between them, springs 32, 32 are mounted to urge both gears 30, 31 in a direction approaching each other.

A boss 36 having cut grooves 36a, 36a facing each other is formed on the opposing surfaces of both gears 30, 31, and a distance collar 38 is hung on the outer peripheral side of both bosses 36, 36. It is attached as a handbook. A groove 38a is formed over the entire outer peripheral surface of the distance collar 38, and the tip of a switching arm 39 is fitted into the groove 38a as shown in FIG. At the rear end of the switching arm 39, the housing 2 is slidably movable in a direction orthogonal to the plane of FIG.
Is connected to the slide switch 40 supported by
The slide switch 40 is slidable from outside the housing 2.

On the other hand, the boss portions 3 of the two gears 30, 31
6 and 36, a pin 37 is diametrically attached to the intermediate shaft 7.
, And both ends of the pin 37 protrude from the peripheral surface of the intermediate shaft 7 as shown in FIG.

When the slide switch 40 is operated from this configuration, the two gears 30 and 31 move integrally on the intermediate shaft 7 leftward or rightward in FIG. 1 by the urging force of the springs 32 and 32. As a result, the protruding portion of the pin 37 is connected to the large gear 30 or the small gear 3.
When the large gear 30 or the small gear 31 is fitted into the cut groove 36a of the first boss portion 36, the large gear 30 or the small gear 31 is connected to the intermediate shaft 7 for rotation. As shown in FIG. 8, a leaf spring 41 is interposed in a sliding portion between the switching arm 39 and the housing 2 so that a slide switch 40 is provided.
Moderate (about overcoming the biasing force of the spring 32)
Sliding resistance is given, and the switching position of both gears 30, 31 is maintained.

The rotary impact tool 1 according to the related invention configured as described above is used as follows. First, in order to use the tool 1 as a rotary impact tool for the purpose of screw tightening or the like from the hitting stop state shown in FIG. 1 to the hitting possible state shown in FIG. 2, the impact case 10 is rotated to the impact side of the scale display. It should be done. As a result, the adjusting member 18 also rotates, and the adjusting claw 20 is moved to the adjusting ring 21.
The adjusting member 18 is moved rearward (to the right in the drawing) by the spring 15. As shown in FIG.
When the adjusting member 18 reaches the deepest portion of the groove portion 22, the adjusting member 18 reaches the retreating end, and this state is a state in which the amount of compression of the spring 15 is the least, and thus the state in which the hammer 12 can retreat with the lightest force, that is, the striking force of the hammer 12 Is the smallest state. Here, if the amount of rotation of the impact case 10 is made smaller than the above, the amount of compression of the spring 15 increases, and the impact force of the hammer 12 can be increased. As described above, by adjusting the rotation amount of the impact case 10, that is, the position of the adjustment member 18, the impact force of the hammer 12 can be adjusted.

Next, the speed change mechanism 5 is switched to the high speed side.
This is because the slide switch 40 is slid to the left in FIG.
6a. As a result, the small gear 31 is connected to the intermediate shaft 7 for rotation, the rotational force of the motor 3 is transmitted to the spindle 6 via the small gear 31, and the rotation speed of the motor 3 is increased by the small gear 31, so that the 6
Rotates at high speed. In this case, the large gear 30 idles on the intermediate shaft 7.

As described above, the switching to the hittable state is completed by retracting the adjusting member 18 and switching the transmission mechanism 5 to the high speed side. If the motor is rotated by operating the trigger in the hittable state, the tool 1 can be used as a rotary impact tool. The operation as this rotary impact tool is conventional and will not be described in detail.

Next, a case where the tool 1 is used simply as a drill for the purpose of drilling wood, for example, will be described. In this case, the impact case 10 may be rotated in the opposite direction, whereby the adjusting member 18 also rotates, and the adjusting claw 20 moves the groove 22 of the adjusting ring 21 in a shallow direction. 18 moves forward against the spring 15. Thereby, the spring 15 is finally compressed to a position where the hammer 12 cannot be retracted (the state of FIG. 1). As a result, the hammer 12 is pressed against the anvil 11 and is always engaged, so that the hammer 12 is not hit.

Further, the speed change mechanism 5 is switched to the low speed side. That is, the slide switch 40 is slid rightward in FIG. 1, and the pin 37 is fitted into the cut groove 36a on the large gear 30 side. As a result, the large gear 30 is rotationally connected to the intermediate shaft 7, so that the torque of the motor 3 is transmitted to the spindle 6 via the large gear 30. Further, in this case, the rotation speed of the motor 3 is reduced by the large gear 30, so that the spindle 6 rotates at a low speed.

As described above, the anvil 11 is connected to the hammer 12
The tool 1 can be rotated with a high torque without being hit by the tool 1, and the tool 1 can be used in a good state as a drill.

As described above, the rotary impact tool 1 according to the related invention has a structure in which the hammer 12 has a striking stop mechanism and the speed change mechanism 5, so that it is as good as the conventional rotary impact tool as before. Not only can it be used in the state of
The tool (drill) can be rotated at a high torque without overloading the hammer 12, and the hammer 12 can be used in a state where the hammer 12 is securely stopped.

In the hitting stop mechanism, since the hammer 100 is conventionally prevented from retreating by the engagement pin 106, a large force is applied to the engagement pin 106 and the gear case 103 supporting the same. becomes possible, in this order, but these strength is a problem in durability of the result thus the tool in question, related invention illustrated this point
Such a striking stop mechanism is configured to restrict the retraction of the hammer 12 by adjusting the compression amount of the spring 15 by sliding the adjusting member 18, and thus directly restricts the retraction of the hammer 100 by the conventional engagement pin 106. In comparison with the configuration, the impact of the hammer 12 can be stopped without difficulty and reliably, so that the conventional strength problem is eliminated.

Further, in the conventional configuration, the gear case 103
To the cam groove 104 is formed, but foreign matter on the through cam grooves 104 oil leakage and the impact mechanism is a problem entering, as the case with the engaging pin 106 according to the configuration according to the related invention Since there is no need to provide a simple cam groove 104, the sealing performance of the tool does not deteriorate.

Next, an embodiment of the present invention will be described with reference to FIG. In the related invention described above, the hitting stop mechanism of the hammer 12 and the speed change mechanism 5 are exemplified to be operated independently of each other. However, as described below, the structure may be such that both mechanisms can be linked and switched by one touch.

FIG. 9 shows a rotary impact tool 50 in which the two mechanisms are linked. The embodiment described below
In the embodiment, an angle type in which a spindle is disposed at right angles to an output shaft of a motor will be described as an example.

A motor 52 is built in the housing 51, and its output shaft is connected to a planetary gear mechanism 53.
An intermediate shaft 54 is rotatably supported in parallel with the output shaft of the motor 52, and a speed change mechanism 55 is attached to the intermediate shaft 54. This transmission mechanism 55 has a large gear 56 and a small gear 57, similarly to the transmission mechanism 5 in the related invention , and has a boss portion in which a notch groove is formed. A distance collar 58 is attached to the outer peripheral sides of the two boss portions in a bridging manner, and the distance between the two gears 56 and 57 is maintained at a constant distance. A pin 59 is attached to the intermediate shaft 54 between the two bosses, with both ends protruding from the peripheral surface of the intermediate shaft 54 as in the related invention . Also, both gears 5
A spring is mounted on the back side of each of the members 6 and 57 and is urged in a direction to approach each other.

On the other hand, a changeover switch 60 is rotatably mounted on the housing 51 below the gears 56 and 57 in the drawing, and a changeover flange 61 is formed integrally with the changeover switch 60. When the changeover switch 61 is rotated to a fixed position, the changeover flange 61 is located behind the hammer 70 (upper part in the figure) as illustrated.
To the hammer 70 and rotate it 180 °.
The switch 60 is formed eccentrically so as to retreat from behind. Therefore, the changeover switch 60
Is rotated so that the switching flange 61 is extended to the rear of the hammer 70, the retraction of the hammer 70 is prevented, whereby the hitting operation on the anvil 71 can be stopped. When the changeover switch 60 is rotated by 180 ° from the impact stop position, the changeover flange 61 is retreated from behind the hammer 70 and the hammer 70
Can be retracted, so that the stoppage of hammering of the hammer 70 is released.

Further, a switching pin 62 is formed on the inner side surface (upper surface in the drawing) of the switching flange 61 so as to protrude inward. The switching pin 62 is located at a position eccentric to the rotation center of the changeover switch 60 by a certain distance as shown in the figure, and on the side opposite to the projecting side of the switching flange 61, between the large gear 56 and the small gear 57. It is formed so as to protrude. As a result, when the changeover switch 60 is rotated to bring the changeover flange 61 to the rear of the hammer 70, that is, the hammer 70 stops hitting (the state shown in the figure), the changeover pin 62 is moved more than the center of rotation of the changeover switch 60. The gears 56 and 57 are slid rightward in the drawing by moving to the right, whereby the large gear 56 is connected to the intermediate shaft 54 for rotation, and the transmission mechanism 55 is switched to the low speed side.

On the other hand, when the changeover switch 60 is turned 180 ° from the above-described hitting stop state and the changeover flange 61 is retracted from behind the hammer 70, that is, the changeover pin 62 is turned on. 60 to the left of the center of rotation of the
6 and 57 are slid to the left in the figure, whereby the small gear 57 side is connected to the intermediate shaft 54 for rotation, and the transmission mechanism 55 is switched to the high speed side.

The intermediate shaft 54 passes through a bevel gear 72,
The intermediate shaft 54 is rotatably connected to a spindle 73 disposed at right angles to the spindle 73, and a hammer 70 is attached to the spindle 73 via a steel ball 74 so as to be rotatable and movable in the axial direction. The spring 75 urges the spindle 73 toward the anvil 71 rotatably supported by the tip of the spindle 73.

According to the above configuration, when the rotary impact tool 50 is used as a simple drill, it is sufficient to simply rotate the changeover switch 60 to the side where the impact is stopped. That is,
When the changeover switch 60 is rotated to the side where the impact is stopped, the changeover flange 61 is switched to the side protruding rearward of the hammer 70, and at the same time, the transmission mechanism 55 is switched to the lower speed side. When the switch is used as an original rotary impact tool, the changeover switch 60 is set at about 180 degrees from the impact stop side.
, The switching flange 61 retreats from behind the hammer 70, and at the same time, the transmission mechanism 55 switches to the high-speed side.

As described above, the rotational shock of the present embodiment
According to the tool 50, the hammer 70 can only be stopped
Also switch the spindle 73 rotation to low speed rotation
Thus, the rotary impact tool 50 is simply used as a drill.
The motor without overloading it.
Can be rotated with high torque.
This rotary impact tool 50 is the same as the rotary impact tool 1 according to the invention.
Use the tool in a practical condition even as a simple drill.
Can be. Moreover, the rotary impact tool 5 according to the present embodiment
0 is only required to operate the changeover switch 60 and the hammer 7
Switching of hitting stop or release of 0 and lowering of spindle 73
Switching between high speed rotation and high speed rotation is performed in
Rotation that is even easier to use than configurations that operate individually
It can be an impact tool.

[Brief description of the drawings]

FIG. 1 is a partially cutaway side view of a rotary impact tool in a hit stop state and a low-speed rotation state in a technique related to the present invention.

FIG. 2 is a partially broken side view of the rotary impact tool in a hittable state and in a high-speed rotation state.

FIG. 3 is a side view of an adjustment member.

FIG. 4 is a plan view of an adjustment member.

FIG. 5 is a sectional view taken along line BB of FIG. 2;

FIG. 6 is a plan view of an adjustment ring.

FIG. 7 is a development view of a half circumference of a groove of the adjustment ring.

FIG. 8 is a sectional view taken along line AA of FIG. 1;

FIG. 9 is a longitudinal sectional view of an angle type rotary impact tool according to the embodiment of the present invention.

FIG. 10 is a vertical cross-sectional view illustrating a conventional impact stopping mechanism.

[Description of Signs] 1 ... Rotation Impact Tool 2 ... Housing 3 ... Motor 5 ... Transmission Mechanism 6 ... Spindle 10 ... Impact Case 11 ... Anvil 12 ... Hammer 18 ... Adjustment Member 21 ... Adjustment Ring 40 ... Slide Switch 50 ... Rotation Impact Tool (Angle type) 55 ... Transmission mechanism 60 ... Changeover switch 61 ... Changeover flange 62 ... Changeover pin 100 ... Hammer, 101 ... Concave groove 104 ... Cam groove, 105 ... Operation handle, 106 ... Engagement pin

Claims (1)

[Claims] 1. A rotary impact tool having a hammer movable axially with respect to a spindle, connected to the spindle for rotation, and urged to the anvil side by a spring, wherein the hammer is configured to restrict retraction of the hammer. A rotary impact tool comprising: a hitting stop mechanism for preventing the hammer from hitting the anvil; and a transmission mechanism for switching a rotation speed of the spindle between a high speed and a low speed.