JPH0246893Y2 - - Google Patents

Description

[Detailed description of the invention] Purpose of the invention [Industrial application field] The present invention relates to an electric massaging machine, and in particular, to improve the problem of noise caused by the reciprocating movement of a lever connected to a vibrator. Regarding the electric massaging machine.

[Prior Art] Electric massaging machines have been proposed and used for the purpose of loosening stiffness in various parts of the human body and pressing pressure points. These electric massaging machines install vibrators on both sides of a lever that reciprocates via a drive mechanism, impart vibrations of appropriate strength and quality to the vibrators, and press the vibrators against the affected area. The aim is to obtain a suitable massaging effect.

The present inventor has already proposed such an electric massager, such as the "Electric Massage Machine" published in Utility Model Publication No. 1275/1983, which can be used to suit a wide range of affected areas and symptoms of the human body. Invented a massaging machine. These electric massaging machines have a simple structure, are easy to use, and are excellent in that the desired massaging effect can be easily obtained.

[Problems to be solved by the invention] In these electric massaging machines, which use a small motor as a drive source and apply vibration to a vibrator by converting this rotational force into reciprocating motion of a lever, in order to increase the massaging effect of the vibrator, This, together with the fact that the mass of the vibrator is relatively high, makes it difficult to operate the vibrator without pressing it against the affected area.
In other words, some vibration noise was generated during no-load operation.

However, in recent years, there have been remarkable improvements in the functionality of electrical equipment often used in ordinary households, and customer demands have also become higher.
Electric massaging machines and the like have also come to be desired to be even quieter. Therefore, noise such as vibration noise generated during operation of the electric massaging machine has sometimes become a problem. Furthermore, when massaging the neck muscles, shoulders, etc., an electric massaging device is sometimes used near the ear, and from this aspect as well, it is necessary to avoid generating unnecessary noise.

Therefore, the inventor of the present invention conducted extensive research with the aim of reducing this vibration noise, and found that vibration noise is generated by the force applied to the shaft and bearing of the drive mechanism that drives the lever. They came to the knowledge that this force was being exerted, and devised a structure that could reduce this force and reduce noise.

Structure of the invention [Means for solving the problem] The present invention has the following structure as a means for solving the problem in order to achieve the purpose of reducing noise during operation. That is, in an electric massager in which each vibrator is connected to the tip of a shaft extending from both ends of a lever that reciprocates inside a housing by a drive mechanism to the outside of the housing, the vibration between each vibrator and the housing is A spring is interposed between each spring, and the resultant force applied to the lever by each spring is equal to the inertial force applied to the lever and the sliding friction force generated by the reciprocating movement at both dead centers of the reciprocating movement. This is the configuration of an electric massaging machine characterized in that the specifications of each of the springs are determined so that the springs have opposite directions and substantially the same size with respect to the sum.

[Function] The electric massaging machine of the present invention having the above configuration is subjected to the following forces other than the force that causes the lever to reciprocate during no-load operation.

Inertial force: An object of mass M with acceleration α has inertial force −α·M. Therefore, if the lever and the vibrator are connected to each other and move back and forth, they will be subject to inertial force.

Sliding friction force P: When the shaft supported by the bearing slides, the dynamic friction coefficient μ and the force F applied perpendicular to the shaft
According to the sliding friction force μ・in the opposite direction to the moving direction
Receive F.

Force SP due to spring: The lever and the vibrator receive force from the resultant force of the springs interposed between the housing and the vibrator. This spring is used for both vibrators, so
When the lever is in the center position, the forces of the left and right springs are balanced, and the closer you get to one end, the more force you receive to push it back to the opposite side. If the force of one spring is SPr and the force of the other is SPl, then SP=SPr+SPl.

In the electric massaging machine of the present invention, the above forces have the following relationship. In other words, when the reciprocating lever approaches the dead center on both sides (the point where motion in one direction switches to motion in the opposite direction), the force applied to the combination of the lever and the vibrator becomes almost zero. . Expressing this as a formula, I+S+SP≒0...(1) (However, all forces are expressed as positive in the same direction.) In other words, the force due to the spring is calculated so that formula (1) is satisfied. SP(=-(I
+P)) is determined.

Viewed from the side of the drive mechanism that reciprocates the lever, this means that during no-load operation, as the dead center approaches, the spring force changes to SP, and the inertia force to I.
This means that when the moving direction is reversed, no force is applied other than the force that causes the lever to reciprocate due to the drive mechanism. Therefore, almost no force is applied from the outside to the rotating shaft of the drive mechanism that drives this lever, and no impact noise is generated due to the shaft falling.

Incidentally, in the present invention, the spring interposed between the housing and the vibrator may be externally mounted on the shaft, but there is no problem with interposing it at a position separate from the shaft. In addition, the specifications of this spring need only be determined to satisfy the force balance conditions mentioned above, including the free length of the spring, coil diameter, spring constant, etc.
The number of turns, etc. may be selected and determined in combination as appropriate.

[Example] Hereinafter, an example of the present invention will be described in detail based on the drawings.

FIG. 1 is a partially cutaway front view showing an assembled state of an electric massaging machine according to an embodiment of the present invention, and FIG. 2 is a view taken along the -' arrow. In FIG. 2, gears and the like are not shown in cross-section so as not to hinder understanding.

In the figure, reference numeral 1 denotes a handle of an electric massaging machine, which incorporates a small motor 3 as a driving force source. This small motor 3 is driven by a commercial power source, and a power cord 5 for this purpose is led out from the end of the handle by being held between cord bushes 6.
The small motor 3 can be started and stopped by a switch 8 provided on the side of the handle 1.

Reference numeral 10 denotes a casing forming the head of the electric massaging machine, in which a lever box 12 is built in and fixed.
The lever 14 in the lever box 12 has a worm gear 16 attached to the rotating shaft of the small motor 3 and rotated at the bottom 18 of the lever box 12.
A rotating shaft 20 supported by a bearing 19 provided in
It is configured to be reciprocated by engaging and rotating a wheel gear 22 attached to the wheel gear 22. That is, the rotation of the small motor 3 rotates the wheel gear 22 via the worm gear 16, but the rotational movement of the wheel gear 22 is caused by the rotation of the gear pin 26 which is erected on the wheel gear 22 and covered by the bush 24. The lever 14 functions as a drive mechanism for reciprocating the lever 14 in the left-right direction in the figure through the structure of the rectangular floating hole 28 of the lever 14 that engages with the lever 26 . A buffer member 29 is provided on the inner side of the long side of the floating hole 28 for the purpose of preventing wear caused by sliding of the gear pin 26.

Vibrator shafts 33 and 34 that connect the vibrators 30 and 31 are fixed to the lever 14, and are supported by bearings 36 and 37 installed inside both ends of the lever box 12, and are extended to the outside. ing. A vibrator 30 provided at the tip of the vibrator shafts 33 and 34,
31 has a different shape, and the vibrator 30 on the left side of the figure is
It is larger in shape and mass than the vibrator 31 on the opposite side.

Covers 42 are provided at both ends of the housing 10 in order to prevent the vibrators 30 and 31 from falling off and hair from getting caught.
43 is attached. Therefore, the substantial end of the housing is not visible from the outside.

Springs 50 and 51 are interposed between this end and the vibrators 30 and 31. spring 5
The free lengths of 0 and 51 are each larger than the maximum value of the gap between the vibrators 30 and 31 and the end of the housing 10, and both are used in the compression direction. The repulsive force caused by the springs 50 and 51 will be explained in detail later.

When the switch 8 is closed, the electric massaging machine of this embodiment having the above-mentioned configuration is operated by supplying electric power to the small motor 3. The small motor 3 is started and the worm gear 16 attached to its rotating shaft
When the gear pin 26 rotates, the circumferential movement of the gear pin 26 on the wheel gear 22 that rotates in conjunction with this rotates through the idle hole 28.
The lever 14 is reciprocated through engagement with the lever 14.
Therefore, when the lever 14 moves in one direction, the wheel gear 22 receives a force pushing it in the opposite direction, causing its rotating shaft 20 to fall. When the lever 14 changes its direction of movement at its dead center, the direction of the force exerted on the wheel gear 22 through the engagement of the idler hole 28 and the gear pin 26 also reverses. At this time, the vibrator 30,
When an inertial force or the like acts on the lever 14 to which the rotary shaft 20 is connected, this force is transmitted through the wheel gear 22 and generates a large impact sound as the rotary shaft 20 is tilted. This sound is heard outside as noise.

The electric massaging machine of this embodiment includes a vibrator 30 and a housing 1.
A spring 50 is placed between the oscillator 3 and the outer case.
1 and the outer case of the housing 10.
Each of them is equipped with the following. The force exerted on the lever 14 by the spring 50 is SPl, and the spring 51
The force exerted by SPr is SPr, and the sum is SP (=SPl+
SPr). On the other hand, the lever 14 is connected to the gear pin 26
A reciprocating motion is performed at a speed V by circular motion at a constant speed. Since the circumferential movement is a reciprocating movement, the speed V is greatest even when the lever 14 is at the center, and becomes zero at both dead centers. On the other hand, the acceleration α is zero at the center and maximum at both dead centers. This situation is shown in Figure 3.

The force applied to the lever 14 will be explained below according to the illustration. The inertial force exerted on the lever 14 is given by the total mass including the vibrators 30 and 31 as M=-
It is given as α・M. On the other hand, the frictional force P is given by P=μ·F, where μ is the coefficient of dynamic friction, and F is the force with which the vibrator shafts 33 and 34 are pressed against the bearings 36 and 37 in a direction perpendicular to the shafts.

Therefore, the total power (I + P
+SP) changes as shown in the bottom column of Figure 3.
That is, in the electric massaging machine of this embodiment, the spring 5
The force SP exerted on the lever 14 by 0,51 is
The spring specifications (free length, spring constant, etc.) are determined so that SP=-(I+P) near both dead centers of the lever 14. In particular, the direction of the frictional force P changes when the moving direction of the lever 14 changes, so just before the lever 14 approaches the dead center, SP=-(I+P), that is, the force applied to the lever 14 is balanced. It is desirable to configure it as follows.

4A, B, and C are diagrams conceptually showing the forces exerted by the lever 14, excluding the force exerted by the gear pin 26. FIG. 4A shows the lever 14 passing through approximately the center of its reciprocating stroke from left to right. At this time, the inertial force I and the force SP caused by the springs 30 and 31 are almost zero, and only the frictional force P is being applied.

FIG. 4B shows the lever 14 just before reaching the right-hand dead center of its stroke, at which time the overall force is almost balanced and P+I+SP=0.

Contrary to FIG. 4B, FIG. 4C shows the state immediately before the left dead center of the stroke.

As is clear from the above explanation, the force applied to the lever 14 is balanced near its two dead centers, and in this vicinity the lever 14 to which the vibrators 30 and 31 are connected is affected by the rotation of the gear pin 26. It is moved only by the force generated.
Therefore, at both dead centers, the wheel gear 22 changes the tilting direction of its rotating shaft 20 by its own driving force, and the amount of displacement is within the natural displacement in the floating hole 28 of the gear pin 26, and the inertia The problem of impact noise caused by force, etc. has been fully resolved.

As described in detail above, the electric massager of this embodiment can reduce the vibration generated during operation without impairing the conventional effect of being able to obtain massage effects according to the affected area or symptoms. It was possible to sufficiently reduce noise such as sound. Therefore, even when the electric massager is brought close to the ear, such as when massaging the shoulders, the user can comfortably use the electric massager without worrying about the noise.

Further, in this embodiment, two springs 50, 5
The force balance is achieved using only 1, which has the advantage of being simple in construction and offering a large degree of freedom in design.

Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments in any way, and within the scope of the gist of the present invention, such as using a tension spring as the structure of the spring, etc.
Of course, it can be implemented in various ways.

Effects of the invention As detailed above, according to the electric massager of the present invention, the noise generated during operation can be extremely reduced with a simple configuration without impairing the massage effect of the conventional electric massager. It has excellent effects. Therefore, the electric massaging machine can be used with peace of mind without causing discomfort to the user when used at home or when used on the neck muscles, shoulders, or ears.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway front view showing the structure of an electric massaging machine according to an embodiment of the present invention, Fig. 2 is a sectional view taken along the -' arrow in Fig. 1, and Fig. 3 explains the force applied to the lever 14. The graphs shown in FIGS. 4A, 4B, and 4C are conceptual diagrams illustrating the force applied to each lever 14. 1... Handle, 3... Small motor, 8... Switch, 10... Housing, 12... Lever box, 1
4... Lever, 16... Worm gear, 22...
Wheel gear, 26... Gear pin, 30, 31...
... Vibrator, 33, 34 ... Vibrator shaft, 36, 37
...Bearing, 50, 51...Spring.

Claims (1)

[Claims for Utility Model Registration] An electric massaging machine in which each vibrator is connected to the tip of a shaft extending from both ends of a lever that reciprocates inside a housing by a drive mechanism to the outside of the housing, each of the vibrators and the housing, and the resultant force applied to the lever by each spring is the result of the inertial force applied to the lever and the reciprocating movement at both dead centers of the reciprocating movement. An electric massaging machine characterized in that the specifications of each of the springs are determined so that the sum of the generated sliding frictional forces is opposite in direction and substantially the same in size.