JPH0130506B2 - - Google Patents

Description

[Detailed description of the invention] (Technical field) The present invention relates to electric razor blades.

(Background Art) Conventionally, as shown in FIG. 12, an inner cutter blade 23 is attached to an inner cutter base 24 via a push-up spring 26 that presses the inner cutter blade 23 against an outer cutter 22 in which a hair introduction hole 21 is formed. , motor 28 fixed to main body 27
In the electric shaver blade in which the rotational motion of the motor shaft 28a is transmitted to the inner cutter base 24, as shown in FIG. , inner blade 2
Engagement groove 24 of the inner cutter base 24 that allows the blade 3 to move up and down
Usually, the point of application is supported on the lower surface of a. In addition, Fig. 13 shows the inner cutter base 2.
4 as viewed from below. At this time, the push-up spring 26 is displaced according to the amount of downward depression of the inner blade 23, and the return force generated by the displacement generates a push-up force that presses the inner blade 23 against the outer cutter 22. However, in this type of method, the relationship between the displacement of the push-up spring 26 and the spring load is proportional as shown in FIG. 14, and as the displacement δ increases, the spring load P also increases accordingly. However, after carefully examining the cutting quality, blade load, etc., the optimum displacement amount δ is determined.
Even if set and mass-produced, the push-up spring 2 will usually change due to variations in component dimensions, etc., if the installation condition is observed.
The displacement amount of 6 usually varies within the range of δ _nio to δ _nax . Therefore, as shown in FIG. 14, the upward force of the inner blade 23 that presses the outer cutter 22 changes in the range of P _nio to P _nax , and at P _nio , the outer cutter 22 and the inner blade 23 are not in close contact. In P _nax , the contact pressure between the outer blade 22 and the inner blade 23 is too large, which increases the rotational load on the motor and shortens the life of the battery. There were some drawbacks.

In addition, as in other conventional examples shown in FIGS. 15 and 16, a first push-up spring 26A that pushes up the radially inner side of the inner cutter blade 23 and a second push-up spring 26B that also pushes up the outside of the inner blade 23 are used. By forming different spring shapes and material thicknesses, the second push-up spring 26B acts more strongly than the first push-up spring 26A, and the inner cutter blade 23 is always biased radially inward. There is. In this conventional example,
During use, the tendency of the inner blade 23 to fall radially outward due to the centrifugal force caused by the rotation of the inner blade base 24 is offset, and the inner blade 23 is brought into almost uniform contact with the outer blade 22 over almost the entire length. However, due to the strong push-up force of the second push-up spring 26B, the inner blade 23 is installed at an angle as shown in FIG. 17, and the inner cutter blade 23 and outer cutter 22 are Until the inner blades 23 are completely assembled as shown in FIG. 15, the inner blade 23 is caught on the inner surface of the engagement groove 24a, making it difficult to move up and down. As a result, the adhesion between the inner cutter blade 23 and the outer cutter 22 deteriorated, resulting in drawbacks such as a feeling of tension when cutting beards.

(Object of the Invention) The present invention has been proposed in view of the above points, and its purpose is to improve the adhesion between the outer cutter and the inner cutter blade by maintaining appropriate contact pressure without variation, and An object of the present invention is to provide an electric razor blade that has improved cutting quality and stabilized quality and load performance.

(Disclosure of invention) The present invention will be explained below with reference to the drawings.

1 to 5 relate to the first embodiment of the present invention. In FIG. 1, on the inner surface of the outer cutter 2 in which the hair introduction hole 1 is formed, a plurality of The inner cutter blades 3 are each pressed by push-up springs 6 made of wire rods or the like, one end of which is latched to the support portion 3a (see FIG. 2). The motor shaft 8a of the attached motor 8 is engaged, and the rotation of the motor 8 is transmitted. Further, a spring support stand 5 is fixed to the inner cutter base 4 below the inner cutter base 4, and each push-up spring 6 is attached to this spring support stand 5.

Next, the mounting state of the push-up springs 6 will be explained based on FIG. The other end of each of the inner cutter blades 3 is arranged on a slot 5c which can receive the support part 3a of the inner cutter blade 3. Also, below the substantially central portions of the push-up springs 6 in the length direction, spring fulcrum portions 5a each having a substantially triangular planar shape are provided on the upper surface of the spring support base 5. These spring fulcrum parts 5a each have an inclined ridge line 5b on both sides of the upper surface, and the push-up spring 6 is configured to move slightly along the inclined ridge line 5b.

Then, the inner cutter base 4 and the spring support base 5 are combined so that the end of the push-up spring 6 is inserted into the elongated hole of the support part 3a of the inner cutter blade 3 attached to the inner cutter base 4, Thus, it constitutes the inner blade body.

In the first embodiment configured as described above, when the distance H ₁ between the spring support 5 and the outer cutter 2 is large as shown in FIG. 4A due to variations in parts, the push-up spring 6 The spring fulcrum part 5 does not displace much.
The contact point A of the push-up spring 6 on the inclined ridgeline 5b of a is located above, and the distance l ₁ to the push-up spring action point B becomes small. Conversely, as shown in Fig. 4B, the spring support stand 5
When the distance _H2 to the outer cutter 2 is small, the displacement amount of the push-up spring 6 becomes large, and the contact point A between the push-up spring 6 and the spring support portion 5a slides downward on the inclined ridge line 5b, and the contact point A and Distance to point of action B of push-up spring 6
l ₂ will be longer. In addition, with the movement of the push-up spring 6,
Its tip portion moves within the elongated hole of the support base 3a of the inner cutter blade 3, so that the push-up spring 6 is not bent in the direction of rotation of the inner cutter body. Further, in FIG. 4, the inner cutter base 4 is omitted for convenience.

As described above, one feature of the present invention is that the increase in the push-up load due to the increase in the displacement of the push-up spring 6 is alleviated by increasing the distance from the contact point A to the point of action B. It is.

The relationship between the displacement of the push-up spring 6 and the load at this time is:
As shown in FIG. 5, it can be seen that the spring constant (P/δ), that is, the slope, is large up to a certain displacement δ ₀ and becomes small beyond that. Therefore, if the optimal mounting position of the push-up spring 6 is set at a location larger than δ ₀ , for example, the set displacement of the push-up spring 6 will vary from δ _nio to δ _nax due to component dimensions and assembly errors. Tsutsumo inner blade 3
The force pushing up changes only from P _nio to _{P nax} , and the contact pressure between the outer blade 2 and the inner blade 3 changes compared to the conventional spring structure (which changes greatly from P' _nio to P' _nax ). This means that the variation in the values will be small and stable.

As described above, in this first embodiment, the push-up spring 6 is constructed so that the spring constant is large when the amount of displacement is small, and the spring constant is small when the amount of displacement is large. By configuring the inner cutter blade 3 to be in sliding contact with the outer cutter 2 at the position of the outer cutter, even if there are variations in the dimensions of each component or variations in the displacement of the push-up spring 6 during assembly, the outer cutter 2 and the inner cutter The change in the contact pressure of the blade 3 is stable and not large, and there is no disadvantage that the contact pressure decreases and the cutting quality deteriorates, or that the contact pressure increases, resulting in a large load and shortened battery life. This ensures taste and load performance.

Next, FIGS. 6 and 7 show a second embodiment of the present invention. In this embodiment, a bifurcated push-up spring 6A is provided on the lower surface of the inner cutter base 4A at an angle of approximately 120 degrees.
Attach three pieces, and attach the inner cutter base 4A by the tip of each.
The individual push-up springs 6A are composed of a first push-up spring 6A ₁ and a second push-up spring 6A ₂ , and each push-up spring 6A is a spring that can support approximately the center portion in the length direction of the second push-up spring 6A ₂ . A fulcrum portion 5a' is provided below. As shown in detail in FIG. 6, this spring fulcrum portion 5a' has a substantially arcuate upper surface.

In this embodiment, when the second push-up spring _6A2 is bent to a certain extent, it comes into contact with the upper surface of the spring fulcrum portion 5a', and the spring length is apparently shortened and the spring constant is increased. The spring constant of push-up spring 6A ₂ is small when the displacement is small, that is, when the outer cutter 2 is not attached, and when the displacement is large, that is, when the outer cutter 2 is attached, the spring constant is small. It is set nonlinearly so that the constant becomes large.

FIGS. 8 and 9 show the relationship between the displacement of the push-up springs 6A ₁ and 6A ₂ and the spring load in this embodiment, and either characteristic may be used. In other words, when the inner cutter blade 3 and the outer cutter 2 are combined, the setting is made so that the position is at or above point C in the figure, and as shown in FIG. ₁ spring constant k ₁ is the second push-up spring 6
The spring constant k ₂ of A ₂ is larger than k ₃ , and k ₂ is
k ₃ or, as shown in FIG. 9, set k ₁ =k ₂ up to point C and then set the spring constant of the second push-up spring 6A ₂ to k ₃ . Note that, experimentally, better results have been obtained with the former method in which k ₂ is set smaller than k ₁ .

According to this embodiment, the spring constant k ₃ of the second push-up spring 6A ₂ is made larger than the spring constant k ₁ of the first push-up spring 6A ₁ to increase the load on the outer peripheral side of the inner cutter blade 3. Therefore, regardless of the centrifugal force when the inner cutter rotates, good adhesion between the inner cutter blade 3 and the outer cutter 2 can be maintained, and the vertical movement of the inner cutter blade 3 can be performed smoothly. It is difficult for the inner blade 3 to escape downward during cutting,
Therefore, the sharpness can be improved. Furthermore, if the upper surface of the spring fulcrum portion 5a' is made into a gently curved surface as shown in FIG. 6, and the second push-up spring _6A2 is configured to gradually come into contact with the top surface, as shown in FIGS.
The relationship between the displacement and load of the push-up springs 6A ₁ and 6A ₂ shown in the figure changes in a curved manner.

Next, FIG. 10 shows a third embodiment of the present invention, in which the push-up spring 6A ₁ of the second embodiment,
In addition to 6A ₂ , the outer cutter 2B is attached to the outer cutter frame 2A, which has vertical space provided in the outer cutter holding part 2A', and the outer cutter 2B itself can float in the vertical direction. In a state where the skin is not pressed against the outer cutter 2B, the outer cutter 2B moves upwards due to the push-up load of the inner cutter blade 3, and operates with a smaller push-up load on the inner cutter blade 3. , when pressed against the skin, the outer blade 2B
The structure is such that the inner cutter blade 3 is moved downward and the push-up load on the inner cutter blade 3 is increased. In this structure, when the skin is not pressed against the outer cutter 2B, the displacement of the push-up spring is set to point D in Fig. 11, and when the skin is pressed, it is set to point E, and when the skin is pressed, the push-up load of the push-up spring is increased, and the displacement of the push-up spring is increased during cutting. This prevents the escape of the blade 3 and the increase in the gap between the inner and outer blades, thereby preventing poor cutting quality such as a feeling of tension in the beard, providing an electric razor with good cutting ability, and providing an electric shaver with good sharpness. The blade sliding load can be reduced and the life of batteries or rechargeable batteries can be extended.

(Effects of the Invention) As described above, according to the present invention, there is an outer cutter having a hair introduction hole, an inner cutter blade that slides on the inner surface of the outer cutter, and an inner cutter blade that is pressed against the inner surface of the outer cutter. In the electric shaver blade equipped with a push-up spring, since the spring fulcrum section is configured to support approximately the intermediate position between the support position of the push-up spring and the push-up position of the inner cutter blade, dimensional variations in the component parts can be avoided. Even in such cases, the contact pressure between the outer cutter and the inner cutter blade can be maintained appropriately to ensure that they are in close contact with each other, which has the effect of improving cutting quality and stabilizing quality and load performance.

[Brief explanation of drawings]

Figures 1 to 5 show the first embodiment of the present invention, with Figure 1 being a longitudinal sectional view, Figures 2 and 3 being perspective views of essential parts, and Figures 4 A and 4 explaining the operation. 5 is a characteristic diagram, and FIGS. 6 to 9 show a second embodiment of the present invention. FIGS. 6 and 7 are explanatory diagrams of the inner cutter base, and FIGS. 10 and 11 show a third embodiment of the present invention, FIG. 10 is a half-sectional view, FIG. 11 is a characteristic diagram, and FIG. 12 is a sectional view showing a conventional example. , FIG. 13 is a perspective view of the inner cutter base, FIG. 14 is a characteristic diagram, FIG. 15 is a half sectional view showing another conventional example, and FIG. 16 is a bottom view of the inner cutter base. FIG. 17 is also an explanatory diagram. 1... Beard introduction hole, 2, 2B... Outer blade, 3...
Inner cutter blade, 4, 4A... Inner cutter base, 5... Spring support, 5a, 5a'... Spring fulcrum, 5b...
Inclined ridgeline, 6, 6A, 6A ₁ , 6A ₂ ... push-up spring.

Claims (1)

[Claims] 1. An electric shaver blade comprising an outer cutter having a hair introduction hole, an inner cutter blade that slides on the inner surface of the outer cutter, and a push-up spring that presses the inner cutter blade against the inner surface of the outer cutter, wherein the inner cutter A spring support is provided on the inner blade base to which the blade is attached, and the spring support can support a position approximately halfway between the support position of the push-up spring and the push-up position of the inner blade along the ridgeline of the upper surface of the spring support. An electric shaver blade characterized in that the push-up spring has a characteristic that when the amount of displacement is small, the spring constant is large, and when the amount of displacement is large, the spring constant is small.