JP2002370180A - Tool holding device for impact tools - Google Patents

Abstract

(57) [Problem] An object of the present invention is to insert a tip tool into a front cover without the necessity of providing a cutting portion on a front cover and increasing the size of a ball serving as a locking member. The tip tool can be securely and accurately held,
An object of the present invention is to provide a tool holding device for an impact tool that can be reduced in size and weight. SOLUTION: An annular member 5 receiving the urging force of a first spring 8 as urging means is provided, and a hole 5b extending in the radial direction of the tip tool 1 is provided in the annular member 5, and a hole 5b is provided in the hole 5b. A plate 6 is provided, which is mounted in the through hole 2a and can contact the ball 3 as a locking member.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tool holding device for holding a tip tool of an impact tool such as an electric hammer and a hammer drill.

[0002]

2. Description of the Related Art There is a conventional tool holding device for an impact tool as disclosed in Japanese Patent Publication No. 3-43003.

In this conventional tool holding device, a through hole is provided in a front cover for storing a tool bit, and a locking member movable in the axial direction of the tool bit and in the radial direction of the tool bit is provided in the through hole. A sliding sleeve is provided on the outer periphery of the front cover, which is movable in the axial direction of the tool bit, restricts the movement of the locking member in the radial direction, and projects the locking member into the front cover. A spring for urging the locking member to be located at a position protruding into the front cover, and a thin plate ring positioned between the spring and the locking member, wherein a tip tool is provided in the front cover. Can be attached only by inserting the tool.

[0004] In detail, when the tip tool is inserted into the front cover, the end of the tip tool comes into contact with a locking member that is positioned so as to protrude into the front cover by the sliding sleeve, and the locking member is a spring. The tip tool moves in the axial direction of the tip tool against the urging force, and the movement of the locking member releases the restriction of the movement of the tip tool in the radial direction by the sliding sleeve. The end portion moves radially outward of the tool bit and does not protrude into the front cover. At this time, the locking member is constantly urged to move radially inward of the tool bit by the urging force of the spring and the shape of the thin plate ring,
When the recess of the tool bit is located below the locking member, the locking member is moved in the through hole again in the axial direction of the tool bit by the biasing force of the spring, and protrudes into the front cover by the sliding sleeve. And the recess of the tip tool engages with the locking member.

[0005]

In the above-mentioned conventional tool holding device for an impact tool, the spring for biasing the locking member disposed in the through hole of the front cover is provided on the outer periphery of the front cover. However, a thin plate ring located between the spring and the locking member and biasing the locking member by receiving the urging force of the spring is provided on the outer periphery of the front cover, and the thin ring is brought into contact with the locking member on the outer periphery of the front cover. In order to transmit the urging force of the spring to the locking member, the locking member must always protrude from the outer periphery of the front cover.
In this configuration, a cutting portion is provided on the front cover so that the radial dimension of the tip tool in the through-hole portion is reduced. For this reason, the thickness of the front cover is reduced by providing the cutting portion on the front cover, and the front cover is damaged if the impact force is large and the impact load applied to the locking member at the time of impact or the like becomes a large impact tool. It had a drawback of fear. In addition, if the diameter of the front cover is increased in order to improve the strength of the front cover, the outer diameter of the holding portion of the tool bit becomes large and the weight cannot be reduced. Was.

If the portion of the locking member that the thin ring contacts is not near the center of the tip tool in the radial direction, the urging force of the spring cannot be accurately transmitted to the locking member, and the thin ring deforms. The thin plate ring and the locking member may bite, and there may be a case where the thin plate ring is positioned above the locking member and the locking member does not return to the predetermined position. For this reason, it is necessary to make the vicinity of the center position of the locking member protrude to the outer periphery of the front cover, and it is necessary to make the size of the locking member relatively large.

[0007] When the tip tool is held by a plurality of locking members, the same number of cutting portions as the number of locking members must be provided on the front cover. It is not practical because the thickness becomes thin. That is, in the conventional tool holding device for an impact tool, the position of the center axis of the tip tool in the front cover cannot be set (centered) by the plurality of locking members, and the plurality of locking members cannot be set. The configuration in which the tip tool is held by the member cannot disperse the impact load applied to one locking member.

It is conceivable to increase the outer diameter of the locking member more than necessary so that the front cover does not need to be provided with a cut portion. In this configuration, however, the through hole of the front cover is enlarged. In this case, the thickness of the front cover is reduced as in the above-described configuration, and the outer diameter of the tool holding portion is increased.

An object of the present invention is to eliminate the above-mentioned disadvantages of the prior art, and to hold the tip tool only by inserting the tip tool into the front cover without limiting the size and shape of the locking member and the front cover. It is intended to provide a tool holding device for an impact tool, which can reduce the size and weight of the impact tool.

[0010]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an annular member which is located between an urging means and a locking member and which receives the urging force of the urging means. This is achieved by providing a radially extending hole and providing a plate mounted in the hole and located in the through hole and capable of contacting the locking member.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a tool holding device for an impact tool according to the present invention will be described below with reference to FIGS. 1 is an enlarged longitudinal sectional view of an essential part showing an embodiment of a tool holding device for an impact tool of the present invention, FIG. 2 is a sectional view taken along line AA of FIG. 1, and FIG. 3 is an impact tool of the present invention shown in FIG. FIG. 4 is a longitudinal sectional view showing a state of the tool holding device when the tip tool is inserted, and FIG. 4 is a longitudinal sectional view showing a state of the tool holding device of the impact tool of the present invention shown in FIG. 1 when the tip tool is removed.

FIG. 1 shows a state in which a tip tool 1 is held,
As shown in the figure, the front cover 2
The ball 3, which is a locking member provided in the through hole 2a so as to be movable in the axial direction of the tool bit 1 and movably in the radial direction of the tool bit 1, is restricted by the holder 4 from moving in the radial direction. It projects into the front cover 2, whereby the tip tool 1 is held in the front cover 2.

As shown in FIG. 2, a ball 3 which is a locking member
Are provided. Similarly, three through holes 2a for holding the balls 3 are provided in the front cover 2.

The holder 4 located on the outer periphery of the front cover 2 is provided with an inner peripheral portion 4b having an inner diameter substantially the same as the outer periphery of the front cover 2, and the ball 3 is located below the inner peripheral portion 4b. At this time, the movement of the tip tool 1 in the radial direction of the ball 3 is restricted, and the ball 3 projects into the front cover 2. The shape of the through hole 2a prevents the ball 3 from falling off the through hole 2a.

A grip 12 is provided on the outer periphery of the front cover 2 and the holder 4 so as to be movable in the axial direction of the tool bit 1.
When the grip 12 moves in the direction away from the end 2b of the front cover 2, the holder 4 and the grip 12 move so that the holder 4 moves away from the end 2b in conjunction with the grip 12. Is the engaging portion 4
c and 12b are provided.

The opposite end 2b of the front cover 2 of the holder 4
An annular member 5 located on the outer periphery of the front cover 2 is provided on the side, and the annular member 5 is constantly urged toward the holder 4 by a first spring 8 as urging means. As shown in FIG. 2, the annular member 5 is provided with three holes 5b extending radially around the axis of the tool bit 1, and a plate 6 is mounted in each of the holes 5b. . Each hole 5b is provided with a step 5c formed so that the size of the hole 5b is increased radially outward of the tool bit 1 so as to be located at a target position, and is mounted in the hole 5b. The plate 6 has a step 6a that contacts the step 5c.
Is provided so that the plate 6 in the hole 5b does not fall into the front cover 2.

The three plates 6 attached to the annular member 5 are provided with through holes 2 provided in the front cover 2 respectively.
The ball 3 protrudes from the ball 3 in the front end 2b toward the opposite end 2b.

On the outer circumference of the ring member 5, on the outer circumference of each plate 6, there is provided a holder 4 and a second spring 9 serving as an urging means.
And the holder 4 receiving the urging force of the second spring 9
Is provided on the end 2b side of the front cover 2 at all times. The sleeve 7 is made of a ring member 5.
And is always positioned above the plate 6 mounted in the hole 5b, and also functions as a retaining member for the plate 6.

As shown in the drawing, when the tip tool 1 is held in the front cover 2, the annular member 5 moves toward the holder 4 by the urging force of the first spring 8 and contacts the holder 4. The holder 4 and the grip 12 are moved to the end 2b side of the front cover 2 by the urging force of the first spring 8 and the urging force of the second spring, and are moved to the end 2b by the tome 11 attached to the front cover 2. The holder 4 is in contact with the washer 10 which is prevented from being pulled out to the side, or the grip 12 is in contact with the cap 13 attached to the front cover 2 via the washer 10 so as to cover the end 2b of the front cover 2. Is maintained in. The ball 3 located in the through hole 2a of the front cover 2 has the inner peripheral portion 4b of the holder 4 positioned above to restrict the movement of the tip tool 1 in the radial direction, and
The range of the axial movement of the tool bit 1 in the direction away from the end 2b is limited by the plate 6 located in a. Note that the movement range of the ball 3 at this time is limited such that the upper end surface of the ball 3 is in contact with the inner peripheral portion 4b of the holder 4 even if the ball 3 is located at a position farthest from the end 2b. desirable.

Next, the operation for mounting the tip tool 1 in the front cover 2 will be described.

When the tip tool 1 is not inserted into the front cover 2, the ball 3, the holder 4, the annular member 5, and the grip 12 are located at the same positions as those shown in FIG. When the tip tool 1 is inserted into the front cover 2 from this state, the end of the flange portion 1b of the tip tool 1 comes into contact with the ball 3 protruding into the front cover 2, and the ball 3 interlocks with the tip tool 1 to form a through hole 2a. Move inside the plate 3
Abut. When the tip tool 1 is further inserted against the biasing force of the first spring 8 applied to the tip tool 1 via the ball 3 and the plate 6, the upper surface of the ball 3 becomes the inclined surface 4 a of the holder 4 as shown in FIG. And the ball 3 comes into contact with the inclined surface 5 a of the annular member 5, and the ball 3 gets over the flange portion 1 b of the tool bit 1.

When the tip tool 1 is further inserted from the state shown in FIG. 2 and the flange 1 b of the tip tool 1 passes below the ball 3, the ball 3 applies the urging force of the first spring 8 to the annular member 5. By receiving through the inclined surface 5a, it moves toward the inside of the front cover 2, and then contacts the plate 6 to move toward the end 2b side in the through hole 2a by the urging force of the first spring 8, as shown in FIG. As shown, the ball 3 is located below the inner peripheral portion 4b of the holder 4. As a result, the ball 3 is formed inside the front cover 2 by the small-diameter
The movement of the ball 3 in the radial direction of the tip tool 1 is restricted in the state where the tip tool 1 is located inside the front cover 2, and the tip tool 1 is held in the front cover 2.

Next, the operation of removing the tip tool 1 from the state in which the tip tool 1 is held in the front cover 2 as shown in FIG. 1 will be described.

The grip 12 is pulled from the state shown in FIG. 1 to move the grip 12 axially away from the end 2 a of the front cover 2. Grip 12 and holder 4
The holder 4 also moves in the axial direction in a direction away from the end 2a in conjunction with the axial movement of the grip 12 because the engaging portions 12a and 4c are engaged. At this time, the urging force of the second spring 9 applied via the sleeve 7 and the urging force of the first spring 8 applied via the annular member 5 act on the holder 4, and the grip 12 Is pulled, the grip 12 is pulled against the urging force of the first spring 8 and the urging force of the second spring 9.

By pulling the grip 12 as described above, the state shown in FIG. 1 is changed to the state shown in FIG. 4, and the tip tool 1 can be removed from the front cover 2. That is, in the state shown in FIG. 1, the inner peripheral portion 4b of the holder 4 is located above the ball 3 held in the through hole 2a in the front cover 2, and the radial movement of the tip tool 1 of the ball 3 is restricted. The ball 3 is projected in the small-diameter portion 1a of the tool bit 1 in the front cover 2, but the grip 12 and the holder 4 move axially away from the end 2a as shown in the figure. By doing
The recess 4 d of the holder 4 is located above the ball 3
The tip tool 1 can be moved in the radial direction, and the tip tool 1 can be removed from the front cover 2. As shown in FIG. 4, the recess 4d provided in the holder 4 has an inner diameter dimension that can accommodate a part of the ball 3 so that the ball 3 does not protrude into the front cover 2, and the opposite end of the recess 4d. On the 2b side, an inclined surface 4 that is inclined away from the end 2b toward the front cover 2
e from the front cover 2 to the tip tool 1
When the front cover 2 is removed, the ball 3 is bitten by the holder 4 and the inner wall on the end 2b side of the through hole 2a.
The phenomenon that the ball 3 does not protrude inside is suppressed.

As described above, the annular member 5 receiving the urging force of the first spring 8 as the urging means is provided, and the annular member 5 is provided with the hole 5b extending in the radial direction of the tip tool 1,
By providing a plate 6 attached to the hole 5b and located in the through hole 2a and capable of contacting the ball 3 serving as a locking member, a cutting portion is provided in the front cover 2 as in the prior art. There is no need to increase the size of the ball 3 serving as a stop member, and the tip tool 1 is placed in the front cover 2.
Thus, it is possible to provide a tool holding device for an impact tool, which can reliably and accurately hold the tip tool 1 only by inserting the tool, and can reduce the size and weight.

Further, the size of the ball 3 as a locking member can be made relatively small, and the shape of the through hole 2a provided in the front cover 2 can be suppressed to a relatively small size. Since there is no need to provide a cutting portion, it is possible to hold the tip tool 1 with a plurality of locking members without increasing the size of the front cover 2, and only to insert the tip tool 1 into the front cover 2. The holding device capable of holding the tool bit 1 is small and lightweight, and the front cover is configured to hold the tool bit 1 with a plurality of locking members, particularly three or more locking members. A tool holding device for an impact tool that automatically suppresses centering of the tip tool 1 by suppressing radial deflection of the tip tool 1 in the tool 2 can be provided. Note that the centering function of the tip tool 1 is useful when the tip tool 1 has the circular small-diameter portion 1a as shown in the above embodiment. But,
The tool holding device for an impact tool according to the present invention includes the above-described tip tool 1.
However, the present invention is not limited to this, and it is possible to employ even a tip tool having a concave portion on a part of the outer periphery as described in Japanese Patent Publication No. 3-43003 described in the related art, The same operation and effect as the above embodiment can be obtained.

In the above-described embodiment, the ball 3 is used as the locking member. However, a substantially cylindrical locking tool extending in the axial direction of the tip tool 1 generally used as the locking member is used. It may be a member.

In the above embodiment, the sleeve 7 for transmitting the urging force of the second spring 9 to the holder 4 is located on the outer periphery of the annular member 5 and is mounted in the hole 5b of the annular member 5 by the sleeve 7. Although the plate 6 is prevented from falling off, for example, the plate 6 may be press-fitted into the hole 5b of the annular member 5 and is a member different from the sleeve 7. The plate 6 attached in the hole 5b of the annular member 5 may be prevented from falling off by a member for preventing the plate 6 from coming off.

In the above embodiment, in order to mount the tip tool 1 in the front cover 2, the tip tool 1 is inserted into the front cover 2, and the tip tool 1 is
In order to relatively increase the load applied to the tool bit 1 when the locking member 3 and the annular member 5 are moved in the axial direction against the urging force of The pressure of the spring of the spring 8 is set to be higher. By increasing the load applied to the tip tool 1 at the time of mounting the tip tool 1 in this manner, the operator can insert the tip tool into the front cover 2. 1 can be reliably detected as being attached. That is, when the tip tool 1 is inserted into the front cover 2 and the locking member 3 gets over the flange portion 1 b of the tip tool 1, the locking member 3 and the annular member 5 are moved by the biasing force of the first spring 8. 2
Is moved to the end 2b side, and the movement completes the mounting of the tool bit 1 in the front cover 2. When the mounting of the tool bit 1 is completed, the operator attaches the first spring 8 In addition to allowing the load due to the force to stop being applied to the tool bit 1,
At the same time, when the attachment of the tip tool 1 is completed, the locking member 3 falls into the through hole 2a of the front cover 2 and the annular member 5
This is to make the contact sound generated when the member comes into contact with the holder 4 via the plate 7 relatively large so that the worker can sense it.

The above-described tool holding device for an impact tool according to the present invention is assembled by the following procedure.

First, the first spring 8 and the annular member 5 are positioned on the outer periphery of the front cover 2, and then the annular member 5 is moved to the end 2 b of the front cover 2 so as to resist the urging force of the first spring 8. From the hole 5b of the annular member 5.
The plate 6 is inserted into each of the holes 5b of the annular member 5 in a state where is positioned on the through hole 2a of the front cover 2.

Thereafter, the annular member 5 is held against the urging force of the first spring 8, and the through-hole 2a of the front cover 2 is held.
The ball 3, which is a locking member, is inserted therein. When the ball 3 is thus inserted into the through hole 2a, the ball 3 is moved by the biasing force of the first spring 8 transmitted through the annular member 5 to the end portion between the plate 6 and the through hole 2a. The ball 3 is pinched by the inner wall on the 2b side so that the ball 3 does not fall out of the through hole 2a.

With the ball 3 inserted into the through hole 2a, the second spring 9 is positioned on the outer periphery of the first spring 8 and abuts on the outer periphery of the annular member 5 with the end face of the second spring 9. A sleeve 7 serving as a retaining member for the plate 6 inserted into the hole 5b of the annular member 5 is located.

Further, the holder 4 and the grip 12 located on the outer periphery of the holder 4 are located on the outer periphery of the front cover 2, and the first spring 8 and the second spring 9 are in a state where the holder 4 is in contact with the sleeve 7. Grip 1 against the urging force of
2 is moved axially away from the end 2 b of the front cover 2. Thereafter, the washer 10 is positioned on the outer periphery of the front cover 2 and the
1 is engaged, and the front cap 13 is attached to the end 2b of the front cover 2 via the washer 10, whereby the assembling work of the tool holding device of the impact tool of the present invention is completed.

As described above, the tool holding device of the impact tool according to the present invention includes a member excluding the plate 6 for assembling the vicinity of the ball 3 which is a locking member for attaching the tip tool 1 to the front cover 2. Are all cylindrical members, which can be assembled only by being located on the outer periphery of the front cover 2, so that the assembly workability can be improved. Also, at the time of assembling work, the first tool which generates the action of attaching and detaching the tip tool 1 is generated.
It is necessary to perform the work against the urging force of the first and second springs 8 and 9. However, the member for maintaining the state against the urging force of the first spring 8 and the second spring 9 is cylindrical. Since this member is used, this point can also be performed without lowering workability. Also, the through hole 2a of the front cover 2
The plate 6, which is a member that regulates the axial movement of the ball 3, is located inside the ring member 5 with the hole 5 b of the ring member 5 positioned on the outer periphery of the through hole 2 a of the front cover 2. Since the assembling can be performed only by inserting the hole into the hole 5b, the assembling operation can be easily performed.

[0037]

According to the present invention, an annular member is provided between the urging means and the locking member and receives the urging force of the urging means. An extended hole is provided, and a plate attached to the hole and located in the through hole and capable of contacting with the locking member is provided, so that a cutting portion is provided in the front cover, and the size of the ball as the locking member is increased. Provided is a tool holding device for an impact tool that can surely and accurately hold the tip tool only by inserting the tip tool into the front cover without the necessity of reducing the size and weight. Will be able to do it.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional side view showing an embodiment of a tool holding device for an impact tool of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG. 1;

3 is a longitudinal sectional view showing a state of the tool holding device of the impact tool of the present invention shown in FIG. 1 when a tip tool is inserted.

FIG. 4 is a longitudinal sectional view showing a state when the tip tool of the tool holding device of the impact tool of the present invention shown in FIG. 1 is removed.

[Explanation of symbols]

1 is a tip tool, 1a is a small diameter portion, 1b is a flange portion, 2 is a front cover, 2a is a through hole, 2b is an end portion, 3 is a locking member, 4 is a holder, 4a is an inclined surface, and 5 is a ring. Member, 5a
Is an inclined surface, 5b is a hole, 5c is a step, 6 is a plate, 6
a is a step, 7 is a sleeve, 8 is a first spring, 9 is a second spring, 10 is a washer, 11 is a tomewa, and 12 is a grip.

Claims (7)

[Claims] A front cover for storing a tip tool having a concave portion, and a through hole provided in the front cover, the front cover being movably arranged in the axial direction of the tip tool and movably in the radial direction. A locking member that protrudes into and engages with the recess of the tip tool, and a holder that restricts and releases the radial movement of the locking member, and projects the locking member into the front cover during the restriction. Biasing means for biasing the locking member so that the holder is positioned at a position where the locking member protrudes into the front cover. A ring member that is located between the lock member and the locking member and receives the urging force of the urging unit; and a hole that extends in a radial direction of the tip tool is provided in the ring member. Mounted on A tool holding device for an impact tool, further comprising a plate located in the through hole and capable of contacting the locking member. 2. A tool holding device for an impact tool according to claim 1, wherein a plurality of said locking members, said holes, and said plates are provided. 3. The tool holding device for an impact tool according to claim 1, wherein at least three or more of the locking member, the hole, and the plate are provided. 4. A tool holding device for an impact tool according to claim 1, further comprising a retaining member located on the outer periphery of said annular member on the outer periphery of said plate. 5. The apparatus according to claim 1, wherein said urging means has a first urging means for urging said annular member and a second urging means for urging said holder. A tool holding device for an impact tool according to claim 4. 6. The stopper member is located between the holder and the second urging means, and is a sleeve for transmitting the urging force of the second urging means to the holder. The tool holding device for an impact tool according to claim 5, wherein 7. The tool holding device for an impact tool according to claim 1, wherein a step is provided to abut on the inside of the hole of the annular member and the plate.