JPS61272615A - Plate spring device for fulcrum of balance - Google Patents

Abstract

PURPOSE:To facilitate adjustment of accuracy of the titled device by holding the upper end side and the lower end side of a plate spring between a couple of contact plates respectively and exposing a plate spring part of a beltlike area to be a fulcrum between both couples of the contact plates. CONSTITUTION:The upper end side and the lower end side of the plate spring 11 are held between a couple of the contact plates 12 and 13, and 14 and 15 respectively and holes 12a-15a for inserting the fitting bolts are formed to these plates. Holes 11a and 11b for inserting the bolts are also formed to the upper part and the lower part of the plate spring 11 so as to form a line with these holes and a clearance l1 is provided between both couples of the contact plates 12 and 13, and 14 and 15, and an exposure part 11c of the beltlike plate spring 11 functions as the fulcrum. The inner end parts of the contact plates 12-15 are made the tapered faces 12b-15b and the bending resistance at the fulcrum part 11c of the plate spring 11 is made small. The thickness t1 of the plate spring 11 is reduced sufficiently.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a leaf spring device for a fulcrum (equivalent to a blade or a blade holder) of a scale, for example, a scale that entirely employs a donkey pal mechanism.

[Conventional technology and its problems]

Figure 5 shows a conventional example of a scale that uses a leaf spring as a fulcrum.(1) is a balance, (2) is a fixed part, (3) is an arm protruding inwardly and outwardly from the balance, and (4) is a balance. It is a pair of leaf springs. The upper ends of both leaf springs (4) are fixed to the stationary @ (2) by bolts (6), and the lower ends are fixed to the arm (3) by bolts (6) to support the balance (1). When a load is applied to the important point (5), the balance (11) tilts due to the deflection of the leaf spring (4).
The deflection (4), that is, the mode of bending, varies depending on the magnitude and manner of load and is not constant. This reduces measurement accuracy.

Figures 6 and 7 show details of the leaf spring (4) in Figure 5 (the mounting bolt (6) is omitted).
Attachment holes (4a) (4b) to the fixing part (2) and the arm (3) are formed at the upper and lower ends. Leaf spring (4)
The thickness of is t, and the portion of length t between both ends serves as a fulcrum, and varies between these points. In other words, measurement accuracy is not constant. Or decrease.

In order to cope with this problem, it has been proposed that the leaf spring be shaped as shown in FIGS. 8 and 9.

In other words, reduce the thickness at the center of the leaf spring (7) t'
It is said that Round holes (7a) (7b) at the top and bottom ends
The fixing part (2) and arm (3) as described above are attached by bolts.
This leaf spring (7) is to be completely fixed,
According to such a leaf spring (7), the bending starting point (within the length t') is always constant at the most bendable part (7 [Problem to be solved by the invention]) The present invention solves the above problem. It is an object of the present invention to provide a leaf spring device for a fulcrum in a frame that is easier to process than conventional ones while improving measurement accuracy.

[Means for solving problems]

The above object is characterized in that the upper end side and the lower end side of the leaf spring are respectively held between a pair of backing plates, and the part of the leaf spring in the band-shaped area that is to serve as a fulcrum is exposed between these pairs of backing plates. This is achieved by a leaf spring device for the fulcrum in the scale.

[For production]

The exposed band-shaped region of the leaf spring acts as a fulcrum, and the measurement accuracy can be improved at a constant level. Furthermore, measurement accuracy or sensitivity can be adjusted by changing the length of the contact plate or the mounting position. There is no need to process the plate springs except for the mounting holes, and the backing plate can be made of any thickness and may be made of a material other than the plate spring material as long as it has the appropriate rigidity. Processing becomes easy.

〔Example〕

Hereinafter, a leaf spring device for a fulcrum according to a valley embodiment of the present invention will be described with reference to FIGS. 1 to 4.

1 and 2 show a first embodiment of the present invention. In the figures, the leaf spring device is designated as a whole by C11, and it is assumed that it is applied to a frame as shown in FIG. Fixed part(
2) The bolts for attaching to the arm (3) are not shown in the figure.

The upper and lower end sides of the leaf springs (11, 1) are respectively held by a pair of abutting plates 0203 and σ 弔← EQUIPMENT, and mounting bolt insertion holes (12a) to (15a) are formed in these, respectively. Bolt insertion holes (ila) (tx
b) is formed. (c) and αΦα of both pairs of plates O
A gap t1 is placed between the haiku and the exposed part (11c) of this belt-shaped leaf spring 0]), which acts as a fulcrum. The inner end of the contact plate α4~α@ is a tapered surface (12h)~(15h)
The bending resistance at the fulcrum part (11) of the leaf spring C11) is made small.The thickness tl of the leaf spring 0υ is sufficiently small, and the bending resistance at the fulcrum part (11) of the leaf spring C11) is sufficiently small. The thickness t' of the meat part (7 ri) is equal to z.

The first embodiment of the present invention is constructed as described above, and its effects will now be explained.

This embodiment is applied to the frame shown in FIG.
), but when a load is applied to the important point (5), the leaf spring device (11) always bends at the exposed portion (11), allowing accurate weighing with constant sensitivity.

Sensitivity or accuracy can be easily adjusted by changing the length of the contact plate Q4~0, that is, by changing the length tl of the exposed portion of the leaf spring (11). Using plates @~α, holes (12a)~(15a)
) may be adjusted by shifting it up and down within the range. In any case, it is not necessary to apply any force to the leaf springs Q and l. The material of the backing plate A4~01 also has thickness and 1i
A variety of materials can be used if the property is taken into account,
For example, it is also possible to use JP.P. in this case,
[Add] Select a material that is easy to stretch.

FIGS. 3 and 4 show a second embodiment of the present invention, and the fulcrum leaf spring device is shown as a whole by a canopy. In this case, the plate spring ρl1 (221 and 23
1 (24+), the fulcrum area of the leaf spring (25) is made more reliably constant.

A pair of protrusions (21a) (21b) and (23a) (23b) are formed on one backing plate 1211 (23+), and these are connected to the round holes (25c) (25c) of plate spring (251) (23+).
d) , (25e) (25f) and the other four parts (22a) (22h), (2
4a) (24h).

Between protrusions (21a) (21h) and (23a) (23b)
In between, there is a plate (2+1 f22) as shown by the dotted line in Figure 3.
1 (231 (24+) plate spring (251 mounting hole (25)
a) Bolt insertion holes are formed in alignment with (25h).

Projections (21a') (21h), (23a) (23b
) and the recesses (22a), (22b), (24a), and (24b), the leaf spring (251 is the contact plate f21) ~ (24
It can always be attached in a fixed positional relationship with respect to 1. That is, a fulcrum region (25g) having a predetermined width t1 is reliably formed in the longitudinal direction of the leaf spring (251), and accuracy can be further improved.

Note that in this case as well, the leaf spring (251) has a hole (25
It is only necessary to form a)-(25f), and by simply using a thin leaf spring (25) with a thickness of t, a predetermined sensitivity can be obtained without any thinning process.

Although the embodiments of the present invention have been described above, the present invention is not limited thereto, and various modifications can be made based on the technical idea of the present invention.

For example, in the above embodiment, notches are formed on both side edges of the leaf spring CIυ(g) to reduce the width between both ends, but a simply rectangular leaf spring is used without forming a notch. You can do it like this.

In addition, the cross-sectional shape of the contact plates (6) to (c) is a tapered surface (12b
) to (15h) are formed to have a trapezoidal shape, but it may be replaced with a rectangular shape.

〔Effect of the invention〕

As described above, the fulcrum leaf spring device of the present invention is easier to process than conventional devices, and sensitivity or accuracy can be easily adjusted.

[Brief explanation of the drawing]

Fig. 1 is a side view of a leaf spring device for a fulcrum according to a first embodiment of the present invention, Fig. 2 is a sectional view taken along line ■-■ in Fig. 1, and Fig.
The figure is a cross-sectional side view of a leaf spring device for a fulcrum according to a second embodiment of the present invention, and FIG. 4 is a cross-sectional view along the line IV-IV in FIG.
FIG. 5 is a perspective view of the main parts of a scale showing a conventional example to which the fulcrum leaf spring device of the present invention can be applied, FIG. 6 is a side view of the leaf spring in FIG. 5, and FIG. 7 is a front view of the same. FIG. 8 is a side view of another conventional example of a leaf spring, and FIG. 9 is a front view of the same. In the figure,

Claims (1)

[Claims] A fulcrum in a scale, characterized in that the upper end side and the lower end side of a leaf spring are each held between a pair of backing plates, and the leaf spring portion of a band-shaped area that is to serve as a fulcrum is exposed between these pairs of backing plates. leaf spring device.