JPS6030003Y2 - Vibration reduction mechanism for reciprocating tools - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a vibration reduction mechanism in a reciprocating tool such as a jigsaw or a saber saw.

Generally, reciprocating tools are equipped with a balance mechanism to prevent vibrations caused by reciprocating motion, but conventional balance mechanisms maintain balance by arranging balance weights that respond in opposite directions to the cutting part. was adopted.

FIG. 1 is a sectional view of a main part of an electric jigsaw equipped with a conventional balance mechanism.

A motor is installed inside the main body cover of the electric jigsaw 1,
When the pinion 2 directly connected to the rotating shaft rotates, the gear 3 rotates around the spindle 5.

The gear 3 has a circular eccentricity 3a, and this eccentricity 3
A balance weight 11 having the shape shown in FIG. 2 is fitted into the hole a.

The balance weight 11 has a horizontally long circular hole at an eccentric position, and is supported by guide pins 12a and 12b so as to be movable up and down, so when the eccentric amount 3a rotates within the horizontally long circular hole, the balance weight 11 reciprocates up and down. do.

FIG. 2 is a front view showing the fitted state of the balance weight and eccentricity in FIG. 1, which corresponds to the left side view in FIG. 3a shows a state in which the balance weight 11 is pushed down to the lowest position.

FIG. 3 is a front view showing the position of the balance weight when the gear has rotated 180 degrees from the state shown in FIG. 2, and the eccentricity 3a pushes the balance weight 11 to the uppermost position.

That is, each time the gear 3 rotates once, the balance weight 11
is caused to reciprocate up and down a distance twice the eccentricity 3a.

Note that the guide pins 12a and 12b are screwed into the main body fixing frame shown in FIG. 1, and fit into the vertical holes of the balance weight 11 to move the balance weight 11 only in the vertical direction. A pin hole for the weight holder 4 is provided in the portion 3a to prevent the balance weight 11 from jumping out from the eccentricity 3a.

In FIG. 1, a weight holder 4 is locked at the tip of the spindle 5, and a stop pin 14 is driven into the pin hole of the eccentricity 3a.

Therefore, the balance weight 11 is supported between the weight holder 4 and the gear 3 so as to be movable up and down.

The weight holder 4 also has a needle roller 13 at its tip.
A pin 6 to which a pin 6 is attached is fixed, and is fitted into a connector 7 via a needle roller 13.

The connector 7 is a groove-shaped member having a U-shaped cross section, and is fixed to the plunger 8.

The plunger 8 is supported movably in the vertical direction by support parts 9a and 9b, and has a saw blade 10 attached to its lower end.

Therefore, when the gear 5 rotates, the weight holder 4 also rotates, causing the saw blade 10 to reciprocate up and down together with the pull plunger 8.

The balance mechanism of the electric jigsaw 1 configured as described above is such that the pin 6 and the stop pin 14 are installed on opposite sides of the spindle 5, so that in the state shown in FIG.
is at the highest position, and the balance weight 11 is at the lowest position.

When the gear 3 rotates 1000 times, the saw blade 10 is at the lowest position, the balance weight 11 is at the highest position, and they reciprocate in opposite phases via the pin 6 to perform balanced motion.

This was effective in reducing vibrations of the electric jigsaw 1.

However, since the centers of the plunger 8 and the balance weight 11 are separated by a distance d, a rotational moment is generated when they move in opposite directions, and the electric jigsaw 1
It makes the whole thing vibrate.

FIG. 4 is an explanatory diagram of the cause of vibration in the electric jigsaw shown in FIG.
If 6 is used as a fulcrum, a rotational moment will be generated that moves the rear part of the body from point A to point B in the case of the solid line arrow, and moves it to point 0 in the case of the broken line arrow, and when cutting at high speed, the bundle It had the drawback of generating vibrations that could be felt even in the hand holding the 15.

The purpose of this invention is to provide a vibration reduction mechanism for reciprocating tools suitable for suppressing vibrations during operation, and its features include an auxiliary weight placed between the balance weight and the opposite side of the cutting part. The auxiliary weight is provided and configured to reciprocate in synchronization with the same direction as the cutting part.

FIG. 5 is a sectional view of a main part of an electric jigsaw which is an embodiment of the present invention, and the same parts as in FIG. 1 are given the same reference numerals.

In this case, an auxiliary weight 18 is fitted into an eccentric seat of a gear 20 that meshes with a pinion 2 driven by a motor.
Guide pins 12a and 12b screwed into the main body fixing frame are inserted into the vertical groove holes of the auxiliary weight 18.

Therefore, when the gear 20 rotates, the auxiliary weight 18 reciprocates in the vertical direction.

Further, a stop pin 14 is installed on the eccentric seat of the gear 20,
A weight holder 21 fitted to the spindle 5 is locked to a gear 20 by a stop pin 14.

This weight holder 21 is eccentric in a direction opposite to the eccentric direction of the eccentric seat of the gear 20, and the balance weight 21 is fitted around it.

Note that the tips of the guide pins 12a and 12b are inserted into a pair of elongated holes provided in the balance weight 19 in the diametrical direction.

A pin 6 is placed on the opposite side of the weight holder 21 from the stop pin 14.
This pin 6 is engaged with the connector 7 via the needle roller 13 as in the case of FIG.

The balance mechanism constructed in this manner operates as follows.

First, when the eccentric seat of the gear 20 is located at the top as shown in Fig. 5, the auxiliary weight 18 fitted thereon is at the uppermost position, and the weight holder 21 that rotates with the gear 20 is eccentric downward. , and the balance weight 19 fitted thereto is at the lowest position.

Further, at this time, the plunger 8 is at the highest position.

That is, the weight holder 21 is lowered, and the plunger 8 and the auxiliary weights 18 arranged on the left and right sides thereof are raised.

Such a positional relationship becomes completely opposite when the gear 20 rotates half a rotation.

FIG. 6 is an explanatory diagram of the electric jigsaw of FIG. 5 in a vibration reduced state.

The solid line arrows indicate the positions of the plunger 8, the balance weight 19, and the auxiliary weight 18 in FIG. 5, and the broken line arrows indicate the state when the gear 20 has made a half rotation.

In this way, the plunger 8 and the auxiliary weight 18 on both sides of the balance weight 19 move in the opposite direction to the balance weight 19 during reciprocation, so they are almost balanced, and the rotation that moves A at the rear of the electric jigsaw 1 up and down. The moment is cancelled.

That is, the vibration and noise of the electric jigsaw 1 are significantly reduced.

In the electric jigsaw of this embodiment, an eccentric part is formed on a gear rotated by a motor, an auxiliary weight is fitted to this eccentric part, and a balance weight is attached to the outer periphery of a weight holder that rotates together with the gear and forms an eccentric part. The plunger and the auxiliary weight are caused to reciprocate in the opposite direction to the weights of the balun by fitting them together and further engaging the plunger with a pin installed in the weight holder.

Therefore, the balance during the back and forth movement is maintained, and vibration and noise can be significantly reduced.

Furthermore, the reduction in the automatic vibration of the electric jigsaw 1 has the advantage of reducing discomfort to the operator who grips and operates the bundle 15, and improving the cutting accuracy of the saw blade 10.

Note that such a vibration reduction mechanism can be applied not only to electric jigsaws but also to general reciprocating tools such as saber saws.

The vibration reduction mechanism for a reciprocating tool of the present invention has the effect of significantly reducing vibration during operation by simply adding an auxiliary weight.

[Brief explanation of drawings]

Figure 1 is a sectional view of the main parts of an electric jigsaw equipped with a conventional balance mechanism, Figure 2 is a front view showing the fitted state of the balance weight and eccentric dust in Figure 1, and Figure 3 is the same as in Figure 2. A front view showing the position of the balance weight when the gear rotates 180' from the state, Figure 4 is an explanatory diagram of the cause of vibration in the electric jigsaw of Figure 1, and Figure 5 is an electric jigsaw that is an embodiment of the present invention. FIG. 6 is a cross-sectional view of a main part of the jigsaw, and is an explanatory diagram of the electric jigsaw shown in FIG. 5 in a vibration-reduced state. 1...Electric jigsaw, 2...Zenion,
3,20...Gear, 4.21...Weight holder, 5...Spindle, 6...
Zen, 7...Connector, 8...Plunger, 9...Support part, 10...Saw blade, 11.19... Balance weight, 12...
...Guide pin, 13...Needle roller,
14...-locking pin, 18...auxiliary weight.

Claims (1)

[Scope of utility model registration request] A reciprocating machine in which a cutting part that reciprocates to cut the workpiece material and a balance weight that reciprocates in the opposite direction corresponding to this cutting part are installed side by side, and the cutting part and the balance weight constitute a balance mechanism. A vibration reduction mechanism for a reciprocating tool, characterized in that an auxiliary weight that reciprocates in synchronization with the same direction as the cutting section is provided on the opposite side of the cutting section, sandwiching the balance weight.