JP6871976B2 - How to adjust the impact force of the chisel urging mechanism, chisel holder, and impact tool - Google Patents

Description

The present invention relates to a chisel urging mechanism attached to an impact tool, a chisel holder for attaching the chisel, and a method for adjusting the impact force of the impact tool.

Conventionally, the chisel attached to the tip of the impact tool can be moved up and down within a predetermined range, and is held by the chisel holder so as not to come off from the impact tool during work. Such a chisel holder is disclosed in, for example, Patent Document 1 and Patent Document 2.

Japanese Unexamined Patent Publication No. 2004-174610 Japanese Unexamined Patent Publication No. 2006-159376

By the way, when a heavy chisel is used, it can be moved up and down by the chisel holder and is held so that it will not come off, but it may be lowered by the weight of the chisel and the hammer may be hit empty. There was a problem.

The present invention has been made in view of the present situation, and an object of the present invention is to provide a chisel urging mechanism capable of solving the problem of a hammer hitting idle.

Another object of the present invention is to provide a chisel holder capable of properly holding a chisel regardless of the type of chisel.

Another object of the present invention is to provide a method for adjusting the impact force of an impact tool, which can adjust the impact force applied to the work.

The present invention is a chisel urging mechanism provided in a chisel holder for attaching a chisel downward to an impact tool having a built-in hammer that reciprocates in the vertical direction, and the chisel is attached to the impact tool. In this state, the hammer can repeatedly collide with the chisel, and when the hammer repeatedly collides with the chisel, the chisel moves to a predetermined standby position and a position moved downward from the standby position. The chisel holder includes a spring that supports the chisel from below and a spring support surface portion that supports the spring from below, and the hammer collides with the chisel located at the standby position. Occasionally, when the chisel moves downward and the spring is in a contracted state and the hammer retracts from the chisel, the chisel resists its own weight to the standby position based on the urging force of the spring. It is a chisel urging mechanism characterized by returning to the ground.

In such a configuration, since the chisel mounted downward is urged by the spring so as to be positioned at a predetermined standby position, the hammer does not hit idle and the impact force of the hammer is appropriately applied. Can be transmitted to the chisel.

In the present invention, the chisel holder is provided with a first shaft member inserted from below into a first through hole provided in the vertical direction, and a spring is provided at the upper end of the first shaft member. A coil spring support surface portion as a support surface portion is formed, and further, the first shaft member is provided with a second through hole formed so as to penetrate in the left-right direction, and the second through hole is also provided. And, the first shaft member is held at a predetermined fixed position in the first through hole by being inserted into the third through hole provided in the chisel holder in the left-right direction and communicating with the first through hole. A shaft member is provided, and a coil spring as the spring is inserted into the first through hole with the vertical direction as the axial direction, and the coil spring is supported by a coil spring support surface portion of the first shaft member. The first configuration is proposed.

Further, the spring is composed of a plurality of partial springs arranged in parallel along the outer peripheral surface of the chisel, and the partial spring is repeated so that at least one wire is partially U-shaped. A second configuration is proposed, which is a plan-view pulse wave spring that is bent in the axial direction to form a split cylinder as a whole.

By adopting the first configuration or the second configuration as described above, the chisel can be positioned while being suitably urged to the standby position.

By the way, if the tip of the chisel is wide with respect to the main shaft, for example, a so-called scaling chisel for fishing, the tip of the chisel cannot be passed through the insertion hole formed in the chisel holder, which is a general purpose. There is a problem that the chisel holder cannot be used or the chisel holder becomes large.

Therefore, a main body portion that surrounds the upper end portion of the chisel is provided, and the main body portion is composed of a plurality of divided bodies, and the chisel is sandwiched from the left and right directions in a state where the chisel is attached to the impact tool. A chisel holder is proposed, which is characterized by being made of.

In such a configuration, since the chisel holder is composed of a plurality of divided bodies, it is not necessary to insert, for example, a wide chisel tip into the chisel holder, and the chisel can be properly held.

Further, the present invention is characterized in that the impact force of the impact tool is changed by changing the urging force of the spring by exchanging the spring and changing the spring constant of the spring. This is the impact force adjustment method.

With such a configuration, the impact force of the impact tool can be adjusted to a desired size. Specifically, increasing the urging force reduces the impact force, and decreasing the urging force increases the impact force.

The chisel urging mechanism of the present invention has an excellent effect that the hammer does not hit idle.

Further, the chisel holder of the present invention has an excellent effect of being able to properly hold a chisel having a large diameter at the tip.

Further, the impact force adjusting method of the impact tool of the present invention has an excellent effect that the impact force can be appropriately adjusted.

It is a front view which shows the state which the chisel is held by the impact tool which concerns on Example 1. FIG. The first division body of the chisel holder which concerns on Example 1 is shown, (a) is the front view which shows the inside, (b) is the back view which shows the outside. The first division of the chisel holder according to the first embodiment is shown, FIG. 2A is a plan view, FIG. 2B is a sectional view taken along line AA of FIG. 2A, and FIG. 2C is FIG. 2 (c). It is sectional drawing of BB line of a). The first shaft member according to the first embodiment is shown, (a) is a perspective view, (b) is a front view, and (c) is a sectional view taken along line CC of FIG. 4 (b). FIG. 5 is a vertical cross-sectional view of a cut surface including an axis of the chisel and an axis of a first shaft member, showing a state in which the hammer does not collide with the chisel in the first embodiment. FIG. 5 is a vertical cross-sectional view of a cut surface which is orthogonal to the cut surface of FIG. 5 and includes an axis of the first shaft member, showing a state in which the hammer does not collide with the chisel in the first embodiment. FIG. 5 is a vertical cross-sectional view of a cut surface including an axis of the chisel and an axis of a first shaft member, showing a state in which a hammer collides with a chisel in the first embodiment. The partial spring according to the second embodiment is shown, (a) is a perspective view, (b) is a plan view, (c) is a rear view, and (d) is a right side view. It is a perspective view which shows the state which attached the partial spring to a chisel. It is a vertical cross-sectional view which shows the state which the hammer does not collide with the chisel in Example 2. FIG. FIG. 5 is a vertical cross-sectional view showing a state in which a hammer collides with a chisel in the second embodiment.

Embodiments of the present invention will be described with reference to the following examples.

[Example 1]
As shown in FIG. 1, the chisel holder 1 has a function of being attached to the tip (lower end) of an air-driven or electric impact tool 2 and holding the chisel 3 downward on the impact tool 2. ..

The chisel 3 has a tip portion (lower end portion) wider than the main shaft portion, and a so-called scaling chisel is adopted.

More specifically, as shown in FIG. 1, the chisel holder 1 is formed by combining a first division body 11 and a second division body 12 such that the cylinder is vertically divided into two along the axis, and the first division is performed. The main body 10 is composed of the body 11 and the second divided body 12. Since the first divided body 11 and the second divided body 12 have the same shape as each other, only the first divided body 11 is shown in FIGS. 2 and 3, and the details of the second divided body 12 are omitted.

As shown in FIGS. 2 and 3, a ring into which C rings 21, 22, 23 (see FIG. 1) as fixing means are fitted on the outer peripheral surface of the first divided body 11 (second divided body 12). Grooves 25, 26, 27 are formed along the circumferential direction.

On the other hand, an impact tool locking groove 14 for locking the tip of the impact tool 2 is formed in the circumferential direction at the upper end of the inner peripheral surface of the first divided body 11 (second divided body 12). .. On the other hand, a reduced diameter portion 16 having an inner diameter smaller than that of the upper end portion is formed at the lower end portion on the inner peripheral surface, and the large diameter portion 4 of the chisel 3 is fitted so as not to be pulled out as described later. It has a matching shape.

Further, as shown in FIG. 3, at the reduced diameter portion 16 of the first divided body 11 (second divided body 12) at a position deviated from the axis, the first through hole 31 penetrates along the vertical direction. It is provided. Further, a third through hole 33 is provided in the wall portion of the first divided body 11 (second divided body 12) along the left-right direction (radiation direction of the chisel holder 1), and the third through hole 33 is provided. Communicates with the first through hole 31.

Further, a pin-shaped first shaft member 40 as shown in FIG. 4 is inserted into the first through hole 31. Here, the upper end portion of the first shaft member 40 is a coil spring support surface portion 41 as a spring support surface portion that supports the lower end portion of the coil spring 60, which will be described later.

Further, the first shaft member 40 is provided with a second through hole 42 provided so as to penetrate in the left-right direction.

Next, the holding structure of the chisel 3 by the chisel holder 1 will be described.
As shown in FIGS. 1, 5, 6, 6 and the like, the first divided body 11 and the second divided body 11 and the second are arranged so that the large diameter portion 4 having a collar shape formed in the substantially middle part of the chisel 3 is located inside the chisel holder 1. The chisel holder 1 is fixed to the impact tool 2 by being sandwiched by the split body 12 from the left-right direction, and the tip convex portion 5 of the impact tool 2 is engaged with the impact tool locking groove portion 14 of the chisel holder 1. Further, the C rings 21, 22, and 23 are fitted into the ring grooves 25, 26, and 27 of the chisel holder 1, and the first divided body 11 and the second divided body 12 are fixed so as not to be separated.

Further, the first shaft member 40 is inserted into the first through hole 31 of the first divided body 11, and the second through hole 42 of the first shaft member 40 and the third through hole 33 of the first divided body 11 are inserted. Then, the rod-shaped second shaft member 50 is inserted. As a result, the first shaft member 40 is held at a predetermined fixed position in the first through hole 31.

Further, a coil spring (spring) 60 having an axial direction in the vertical direction is inserted into the first through hole 31. The lower end of the coil spring 60 is supported by the coil spring support surface 41 of the first shaft member 40 described above, and the upper end of the coil spring 60 is pressed against the large diameter portion 4 of the chisel 3 from below to form the chisel 3. Is supported from below.

Although not shown, a fitting concave groove and a fitting convex portion (not shown) are formed on the contact surfaces that come into contact with each other when the first divided body 11 and the second divided body 12 are butted against each other. When the first divided body 11 and the second divided body 12 are attached to the impact tool 2 while holding the chisel 3, the fitting concave groove and the fitting convex portion are fitted to each other and rattle. Both divided bodies 11 and 12 are fixed without any problem.

Here, the chisel urging mechanism according to the present invention is configured by the first through hole 31, the third through hole 33, the first shaft member 40, the second shaft member 50, and the coil spring 60 of the chisel holder 1.

As described above, with the chisel 3 attached to the impact tool 2 by the chisel holder 1, a hammer arranged in the impact tool 2 and repeatedly moving up and down can repeatedly collide with the rear end (upper end) of the chisel 3. It has become. Here, as shown in FIG. 5, when the hammer 6 does not collide with the chisel 3, the chisel 3 is supported by the coil spring 60 from below and is pushed upward (arrow in FIG. 5) to be predetermined. It is located in the standby position of. Then, when the hammer 6 collides with the upper end of the chisel 3 in this standby state, the chisel 3 moves downward and the coil spring 60 is in the elastic state as shown in FIG. 7. On the other hand, when the hammer 6 retracts relative to the chisel 3, as shown in FIGS. 5 and 6, the chisel 3 resists the weight of the chisel 3 at the standby position based on the urging force of the coil spring 60. To return.

In the configuration described so far, since the chisel holder 1 is composed of the first divided body 11 and the second divided body 12 that sandwich the chisel 3 from the left and right, the chisel 3 having a large tip and a heavy tip is preferably held. Can be done. Further, since the chisel 3 can be properly returned to the standby position, so-called blank hitting is eliminated, and the impact force can be transmitted to the chisel 3 without waste.

In the above-mentioned chisel urging mechanism, the impact force of the impact tool 2 can be adjusted. That is, the impact force applied to the work can be adjusted by replacing the coil spring 60 with a different one and changing the spring constant. Specifically, when the spring constant is increased to increase the upward urging force, the chisel 3 is likely to be forcibly returned to the standby position, and the impact force on the work is reduced. On the other hand, if the spring constant is reduced to reduce the upward urging force, the impact force on the work is increased.

Further, by appropriately changing the position of the coil spring support surface portion 41 of the first shaft member 40 and changing the reaction force of the coil spring 60, the urging force with respect to the chisel 3 can be changed without changing the coil spring 60 itself. be able to.

Next, Example 2 will be described. In the second embodiment described below, those having the same configuration as that of the first embodiment are designated by the same reference numerals, and the description thereof will be omitted.

[Example 2]
In the second embodiment, a partial spring (spring) 80 as shown in FIG. 8 is used.
The partial spring 80 has a plan-view pulse wave shape in which one metal wire is repeatedly bent along the axial direction so as to be partially U-shaped, and becomes a divided cylindrical shape as a whole.

Specifically, in the partial spring 80, the substantially straight vertical straight portions 81, 82, 83, 84 and the arc-shaped curved horizontal curved portions 85, 86, 87, 88, 89 are alternately and continuously. It has a connected shape.

Then, the partial springs 80 are prepared in pairs, and as shown in FIG. 9, they are arranged in parallel so as to face each other along the outer peripheral surface of the chisel 90 below the large diameter portion 94 of the chisel 90. It is inserted into the chisel holder 70, which will be described later. As described above, the pair of partial springs 80, 80 can be attached from the radial direction (side) to the outer peripheral surface of the chisel 90, unlike the conventional one in which the shaft of the chisel 90 is inserted. As a result, even if the chisel 90 has a large-diameter portion at the tip portion and the proximal end portion, a spring can be appropriately attached between the tip end portion and the proximal end portion.

Further, as shown in FIG. 10, the chisel holder 70 includes the first divided body 71 and the second divided body 72 as in the first embodiment. A spring support surface portion 75 is formed on each of the first divided body 71 and the second divided body 72. Therefore, when the chisel 90 and the partial spring 80 are arranged in the chisel holder 70, the partial spring 80 is supported from below on the spring support surface portion 75, and the chisel 90 is supported from below by the upper end portion of the partial spring 80. It is supported.

Here, as shown in FIG. 10, when the hammer 6 does not collide with the chisel 90, the chisel 90 is supported by the partial spring 80 from below and is pushed upward to be positioned at a predetermined standby position. ing. From this state, when the hammer 6 collides with the chisel 90, as shown in FIG. 11, the chisel 90 moves downward and the partial spring 80 is in a contracted state. When the hammer 6 is retracted from the chisel 90, the chisel 90 returns to the standby position based on the urging force of the partial spring 80 against the weight of the chisel 90, as shown in FIG. As a result, the hammer 6 is eliminated from the blank shot, and the impact force can be transmitted to the chisel 3 without waste.

Also in this embodiment, the impact force applied to the work can be adjusted by replacing the partial spring 80 with a different one and changing the spring constant.

The spring support surface portion 75 of the chisel holder 70 and the partial springs 80 and 80 constitute the chisel urging mechanism according to the present invention.

In Examples 1 and 2 described above, the dimensions and shape of each part can be freely selected as appropriate.
Further, for example, in the first embodiment, the second divided body 12 may be provided with a chisel urging mechanism in the same manner as the first divided body 11, and the chisel 3 may be supported from below by two coil springs 60. ..
Further, the number of divided bodies constituting the main body of the chisel holders 1, 70 is not limited to two, and may be, for example, three or more.
Further, the third through hole 33 may not be formed along the radial direction of the chisel holder 1. For example, it may be provided parallel to the division surface of the first division body 11 and the second division body 12. In this case, the second shaft member 50 can be removed while the chisel holder 1 holds the chisel 3, and the first shaft member 40 and the coil spring 60 can be easily replaced.
Further, the shape of the partial spring 80 is not limited to that shown in the second embodiment as long as it can be attached to the chisel 90 from the radial direction of the outer peripheral surface. Further, the number of the partial springs 80 to be adopted is not limited to two, and may be three or more.

1,70 Chisel holder 2 Impact tool 3,90 Chisel 6 Hammer 10 Main body 11 First split body 12 Second split body 31 First through hole 33 Third through hole 40 First shaft member 41 Coil spring support surface (spring support) Face)
42 Second through hole 50 Second shaft member 60 Coil spring (spring)
71 Spring support surface 80 Partial spring (spring)

Claims (3)

A chisel urging mechanism provided in the chisel holder for attaching the chisel downward to an impact tool with a built-in hammer that reciprocates in the vertical direction.
With the chisel attached to the impact tool, the hammer can repeatedly collide with the chisel, and when the hammer repeatedly collides with the chisel, the chisel is placed in a predetermined standby position and the standby position. It is a configuration that converts the position from to the position moved downward,
The chisel holder
A spring that supports the chisel from below and a spring support surface portion that supports the spring from below are provided.
When the hammer collides with the chisel located in the standby position, the chisel moves downward and the spring is in a contracted state, and when the hammer retracts from the chisel, the chisel moves to the spring. Based on the urging force, it returns to the standby position against the weight of the chisel.
A first shaft member inserted from below into a first through hole provided in the chisel holder in the vertical direction is provided, and a coil spring support surface portion as the spring support surface portion is formed at the upper end portion of the first shaft member. Further, the first shaft member is provided with a second through hole formed so as to penetrate in the left-right direction.
Further, the first shaft member is inserted into the second through hole and the third through hole provided in the chisel holder in the left-right direction and communicating with the first through hole to form a predetermined first shaft member in the first through hole. Equipped with a second shaft member that holds in a fixed position
A coil spring as the spring is inserted into the first through hole with the vertical direction as the axial direction, and the coil spring is supported by the coil spring support surface portion of the first shaft member. Chisel urging mechanism featuring. A chisel holder provided with the chisel urging mechanism according to claim 1.
A main body that surrounds the upper end of the chisel is provided.
The main body is composed of a plurality of divided bodies, and the chisel is sandwiched from the left-right direction in a state where the chisel is attached to the impact tool.
A chisel holder that features that. The method for adjusting the impact force of an impact tool provided with the chisel urging mechanism according to claim 1.
By exchanging the spring and changing the spring constant of the spring, the urging force of the spring is changed to change the impact force of the impact tool.
A method of adjusting the impact force of an impact tool.

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