JP3175468B2 - Load detector and tension detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a load detector and a tension detector for detecting the tension of a wire such as a web or a cable such as paper, cloth, film or metal foil.

[0002]

2. Description of the Related Art FIG. 5 is a front view showing a conventional tension detector disclosed in, for example, JP-A-61-28834.
In the figure, 1 is a load detector, 2 is a roll, 3 is a pillow block, 4 is a fixed part, 5 and 6 are rolls for applying a load (tension) to the load detector 1, and 7 is a web or a wire.

Next, the load detector 1 shown in FIG. 5 will be described with reference to FIG. This load detector 1 enables a base 10 for attaching a pillow block to a support member 9 at one end of a plate 8 so as to be able to minutely rotate around the A of a cross spring 11, and through a leaf spring 12 for transmission when a load is applied. The first leaf spring 13 is deflected, and its displacement is detected by the differential transformer 1 as a displacement detecting unit.
4, the load, that is, the tension is detected.

[0004] In such a load detector 1, as shown in the compression force diagram of FIG. 7, the first leaf spring 13 and the mounting portion 9 a of the support member 9 apply a load moment to the first leaf spring 13.
Between the mounting member 9 and the mounting portion 9a of the supporting member 9 in the horizontal direction.
Works, causing a gap between the two.

FIG. 7 is a compressive force diagram of a portion between the first leaf spring 13 and the mounting portion 9a of the support member 9 when a downward load is applied to the base 10. Further, the first leaf spring 13 and the support member 9 are tightened by screws 16.

Next, when an upward load acts on the base 10 contrary to the above, the force changes from compression to tensile force, and the first leaf spring 13 and the mounting portion 9a of the support member 9 move in the opposite direction. Shift occurs. This shift is called hysteresis.

[0007]

Since the conventional load detector is constructed as described above, if the hysteresis is large or if the hysteresis is reduced, the entire apparatus must be large, and there is a problem in durability. It was something that became. Further, if the mechanical accuracy (error / full scale = stroke) is to be maintained due to large hysteresis, the full scale (stroke) must be increased, and as a result, the spring thickness is reduced and the spring constant is reduced. Had to be reduced in natural frequency.

Further, for this reason, the conventional tension detector using this load detector has a low natural frequency and cannot operate a printing machine or the like at high speed.

The present invention has been made in order to solve such a problem, and an object of the present invention is to provide a small-sized load detector having a small hysteresis and excellent durability with a simple structure.

Another object of the present invention is to provide a tension detector which enables high-speed operation of a printing machine or the like by increasing the natural frequency of a load point.

[0011]

According to a first aspect of the present invention, there is provided a load detector, comprising: a base for receiving a load; an H-shape viewed from the side in a direction in which the load is applied; A leaf spring is fixed to the supporting rigid body at the end portion as a supporting portion and receives the load via the base at the other end , and the base is loaded outside the supporting portion of the leaf spring.
It is connected to the supporting rigid body with elasticity so that it can rotate in the direction of
And a displacement detector for detecting displacement of the leaf spring due to the load.

According to a second aspect of the present invention, there is provided a load detector, wherein a base for receiving a load, a horizontal T-shape viewed from the side with respect to a direction in which the load is applied, and one end of the horizontal T-shape is supported. a plate spring for receiving the load through the base at the end of the other is fixed to the support rigid with the supporting portion as a part, the plate
Place the base outside the spring support in the direction in which the load is applied.
Auxiliary plate bar that is rotatably and elastically connected to the supporting rigid body
And a displacement detector for detecting displacement of the leaf spring due to the load.

[0013] tension detector according to the invention of claim 3, wherein
Item 1 uses the load detector according to item 1 .

[0014] tension detector according to the invention of claim 4 is one using a load weight detector according to claim 2, wherein.

[0015]

According to the first or second aspect of the present invention, one end of the H-shaped leaf spring or the horizontal T-shaped leaf spring has one end.
One end of the U-shape is used as a supporting portion, and the supporting portion is fixed to the supporting rigid body at this supporting portion and the load is received at the other end via the base. Ri a small generated hysteresis, also, the leaf spring
The auxiliary leaf spring is located outside the support part of
And the supporting rigid body can be rotated in the direction in which the load is applied.
Small loads with excellent durability
Obtain a double detector .

According to the third aspect of the present invention, hysteresis is provided.
The use of a load detector with small
High-speed operation of machines.

According to the fourth aspect of the present invention, since a load detector having a small hysteresis is used, the natural frequency is increased and the machine can be operated at a high speed.

[0018]

[Embodiment 1] One embodiment of the load detector according to the present invention will be described with reference to FIG. FIG. 1 is a front view, and the same or corresponding parts as those of the conventional one are denoted by the same reference numerals and description thereof will be omitted. In the figure, reference numeral 17 denotes a housing as a supporting rigid body to which the differential transformer 14 is attached, and 18 denotes a housing 17.
A leaf spring fixed on the upper left base 17a by screws 19, has an H-shape when viewed from the side in the direction in which a load is applied, and has one end of the H-shape as a support portion 18a. And fix the other end 1
At 8b, it contacts the lower surface of the base 10. 20 is a leaf spring 18
The base 10 and the housing 17 are elastically coupled to each other so as to be rotatable in a direction in which a load is applied by an auxiliary leaf spring disposed outside the supporting portion 18a.

Next, the operation will be described. The base 10 whose vertical direction is regulated by the auxiliary leaf spring 20 is rotated around the point C of the auxiliary leaf spring 20 by the load acting on the base 10 in the vertical direction, and the leaf spring 18
Flex in the direction of 1. When the core 14a of the differential transformer 14 is displaced relative to the coil 14b by the displacement due to the rotation of the base 10, a voltage proportional to the relative displacement is output. This voltage, that is, the load is detected.

As described above, the leaf spring 18 is formed in an H-shape, and the support portion 18a formed at one end of the
When fixed on 7a, the hysteresis generated between the support portion 18a of the leaf spring 18 and the base 17a of the housing 17 is reduced.

This will be described in detail with reference to a compression force diagram shown in FIG. In FIG. 2, the direction of the line indicates the principal stress direction, and the size of the line indicates the magnitude of the principal stress. FIG.
As is clear from FIG. 7, the stress component in the X-axis direction is
It can be seen that the force is alleviated toward the tip of the housing 17 and greatly attenuated at the interface between the housing 17 and the base 17a. Therefore, the shearing force in the X-axis direction acting on the interface between the support portion 18a of the leaf spring 18 and the base 17a of the housing 17 is small, and the movement of the support portion 18a of the leaf spring 18 is completely reduced by the screw tightening force in the Y-axis direction. You can stop it. Therefore, the load detector has excellent hysteresis characteristics.

Embodiment 2 FIG. One embodiment of the load detector according to the second aspect of the present invention will be described with reference to FIG. In FIG. 3, reference numeral 22 denotes a leaf spring which replaces the leaf spring 18 in the first embodiment. 22a, the supporting portion 22a is fixed on the base 17a of the housing 17 and the other end 22a.
Although not shown in b, it contacts the lower surface of the base 10.

Since the leaf spring 22 is fixed on the base 17a of the housing 17 by the support portion 22a similarly to the leaf spring 18 in the first embodiment, the support portion 22
a and the hysteresis generated between the base 17a of the housing 17 is reduced, and the same effect as in the first embodiment can be obtained.

When the leaf spring 22 is formed in a horizontal T-shape as in the second embodiment, the effect that the cost and size are more advantageous than the H-shaped leaf spring 18 of the first embodiment is obtained. can get. That is, the H-shaped leaf spring 18 has high accuracy but is slightly higher in cost, and the horizontal T-shaped leaf spring 22 is slightly lower in accuracy but is advantageous in cost.

[0025] In the above SL Examples 1 and 2, the central idea is provided an auxiliary leaf spring 20 fixed by both screws 23 as shown in FIG. 1, the base 10 is the point C by a thin auxiliary leaf spring 20 The base 1
The degree of freedom of 0 can be restricted from the two degrees of freedom of rotation of the leaf spring 18 or 22 and the vertical direction to one degree of rotation in the direction of rotation of the auxiliary leaf spring 20, thereby stabilizing the output. And further downsizing is possible.

Embodiment 3 FIG. In the above embodiment, the differential transformer 14 is shown as a displacement detecting unit for detecting displacement due to a load on the housing 17, but the same effect can be obtained by using a displacement detecting element such as a PSD (position detector). As shown in FIG. 4, the same effect can be obtained by bonding the strain gauges 24 above and below the leaf spring 18 to form a bridge circuit and connecting the output to the amplifier 25 in the housing 17.

Embodiment 4 FIG. One embodiment of the tension detector according to the third and fourth aspects of the present invention will be described. The load detector 1 of the tension detector shown in FIG.
Is used instead of

Since the load detector thus replaced has a small hysteresis, in FIG.
The displacement at the load point of the tension acting in the direction perpendicular to zero becomes smaller.
Therefore, the accuracy of the mechanical accuracy (error / stroke) is improved by reducing the error when the spring stroke is the same as the conventional one. If the accuracy is the same as the conventional one, the stroke can be reduced. That is, since the spring constant can be increased by increasing the spring thickness, the natural frequency of the tension detector increases, and the machine can be operated at high speed.

[0029]

As described above, according to the first aspect of the present invention, the hysteresis is reduced and the durability is reduced due to the simple structure of fixing the H-shaped leaf spring to the housing with the support portion consisting of one end thereof. A small load detector with excellent resistance is obtained , and an auxiliary leaf spring is arranged outside the support part of the leaf spring.
Output stabilization and further downsizing
There is an effect that it becomes possible .

According to the second aspect of the present invention, by forming the leaf spring in a horizontal T-shape, it is possible to obtain an advantage that it is advantageous in terms of cost and size , and to provide an auxiliary plate outside the supporting portion of the leaf spring.
By arranging the spring, the output can be stabilized and
Further miniaturization becomes possible .

According to the third aspect of the present invention, the natural vibration of the load point is provided.
Enables high-speed operation of printing machines, etc. by increasing the number
Thus, an effect of obtaining a tension detector that is suitable for use is obtained.

According to the fourth aspect of the present invention, there is an effect that a tension detector capable of operating a printing machine at high speed can be obtained by increasing the natural frequency of the load point.

[Brief description of the drawings]

FIG. 1 is a front view showing a first embodiment of the present invention.

FIG. 2 is a compression force diagram in FIG.

FIG. 3 is a front view of a main part showing Embodiment 2 of the present invention.

FIG. 4 is a front view showing a third embodiment of the present invention.

FIG. 5 is a front view showing a conventional tension detector.

FIG. 6 is a front view showing a conventional load detector.

FIG. 7 is a compression force diagram in FIG.

[Explanation of symbols]

 Reference Signs List 10 Base 14 Differential transformer 17 Housing 17a Housing base 18 H-shaped leaf spring 18a H-shaped leaf spring support 20 Auxiliary leaf spring 22 Lateral T-shaped leaf spring 22a Support for horizontal T-shaped leaf spring

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G01L 1/14 G01L 1/26 G01L 5/04-5/10 G01G 21/24 G01G 3/08

Claims (4)

(57) [Claims] 1. A base which receives a load, forms an H-shape when viewed from the side with respect to the direction in which the load is applied, and has one end of the H-shape as a supporting portion, and is fixed to a supporting rigid body by the supporting portion. A leaf spring receiving the load via the base at an end of the leaf spring, and loading the base outside the supporting portion of the leaf spring.
Resiliently connected to the supporting rigid body so that it can rotate in the direction of weight
And a displacement detecting section for detecting displacement of the leaf spring due to the load. 2. A base for receiving a load, a T-shape viewed from the side in the direction in which the load is applied, and one end of the T-shape serving as a support portion, which is fixed to a supporting rigid body by the support portion. A leaf spring that receives the load via the base at the other end, and the base is provided outside a supporting portion of the leaf spring.
Into a rigid support body with elasticity so that it can rotate in the direction in which load is applied.
A load detector , comprising: an auxiliary leaf spring to be coupled; and a displacement detection unit for detecting displacement of the leaf spring due to the load. 3. A tension detector using the load detector according to claim 2 . 4. A tension detector characterized by using a load weight detector according to claim 1, wherein.