JPH039535Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a coil spring formed by winding a spring wire into a coil shape.

[Prior Art] In a device that displaces a movable member against the biasing force of a coil spring, when loads of different magnitudes are applied to different positions of the movable member,
It may be necessary to have approximately the same amount of spring deflection at each position of the movable member.

For example, as shown in FIG. 5a, in an elastic support device 6 in which a pressing plate 5 is supported on a base 4 via a coil spring, biases of different magnitudes are generated at points A and G of the pressing plate 5. Loads Fα and Fβ (Fα
>Fβ. ) is added, point A and G
It may be necessary to equalize the displacement of the pressure plate 5 at the points.

In this case, in the conventional device, as shown in FIGS. 5a and 5b, coil springs 1 to 3 having different spring constants are interposed between the base 4 and the pressing plate 5, and the spring constants of the coil springs 1 to 3 are By appropriately setting the springs 1 and 3 at points A and B, respectively,
The deflection loads required to deflect the same amount by the same amount are Fα and Fβ, respectively.

[Problem to be solved by the invention] As described above, in the conventional elastic support device 6 using a coil spring, when a bias load Fα is applied to a specific position A of the device and Fα is applied to another position G,
In order to obtain approximately the same amount of deflection at each position when bias loads Fβ having different magnitudes are applied, it was necessary to use a combination of a plurality of coil springs 1 to 3 having different spring constants. As a result, there were problems in that the number of parts increased and the device became larger.

The purpose of the present invention is to provide a coil spring that can be independently applied to applications where it is necessary to equalize the amount of deflection at each location when bias loads of different magnitudes are applied to different locations. It's about doing.

[Means for Solving the Problems] The present invention has a coil winding body formed by winding a spring wire with a constant cross-sectional area into a coil, and the outer periphery of each turn of the spring wire in a predetermined region in the circumferential direction. A feature is that the cross-sectional area of the spring wire of each turn in the predetermined region is made smaller than the cross-sectional area of the spring wire of each turn in the other region by cutting the side portion or the inner circumference side portion. That is.

[Operation] As described above, each turn in the predetermined region is cut by cutting the outer circumference side part or the inner circumference side part of the spring wire of each turn in a predetermined area in the circumferential direction of the coil winding body. When the cross-sectional area of the spring wire is made smaller than the cross-sectional area of the spring wire of each turn in other regions, the spring constant in a predetermined region in the circumferential direction of the coil can be made smaller than the spring constant in other regions. I can do it. Therefore,
When bias loads of different magnitudes are applied to a specific position G in a predetermined area in the circumferential direction of the coil and a specific position A in another area, the amount of deflection of the spring at each position G and A is approximately equal. It becomes possible to do so. Therefore, when it is necessary to equalize the amount of deflection at each location when bias loads of different magnitudes are applied to different locations, there is no need to use multiple coil springs.
Can be applied alone.

Furthermore, as described above, by cutting the outer circumferential side or the inner circumferential side of the spring wire of each turn in a predetermined area of the coil winding body, regions with different spring constants can be formed. Since the coil winding body can be formed from spring wires having a constant cross-sectional area and then processed to form regions having different spring constants, manufacturing can be facilitated.

[Example] Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

Figures 1a and 1b show a coil spring 11 according to a first embodiment of the present invention. A body 13 is formed, and the outer peripheral side portion 14a of the spring wire 14 of each turn is cut in a predetermined region in the circumferential direction of the coil wound body 13, so that the spring wire of each turn in the predetermined region is cut. The cross-sectional area of the wire is smaller than the cross-sectional area of the spring wire of each turn in other regions.

In the illustrated example, after a spring wire having a constant cross-sectional area is wound into a coil shape to form a coil-wound body 13,
A region from a position D that is displaced 90 degrees in the circumferential direction with respect to a specific position A in the circumferential direction of the coil wound body to another specific position G that is displaced 180 degrees with respect to the specific position A is defined as a predetermined region, In this predetermined region, the outer peripheral side portion 14a of the spring wire of each turn is shaved off. As a result, the spring constant at a specific position G in a predetermined area is changed to a specific position A in another area.
(In the illustrated example, it is 180 degrees away from the specific position G.)
The spring constant is smaller than the spring constant at .

The spring constant here refers to the ratio F/x between the force F applied to a certain position in the circumferential direction of the coil spring 11 and the amount of deflection x of the coil spring generated at the position where the force F is applied.

In the above-mentioned coil spring, the biasing load required to obtain the same amount of deflection at different circumferential positions A to G (see FIG. 1a) changes as shown in FIG. 2. In other words, a large bias load is applied to point A.
The amount of deflection when Fγ is applied is approximately equal to the amount of deflection when a bias load Fδ smaller than Fγ is applied to point G.

3a and 3b show a second embodiment of the present invention, in which a spring wire with a constant cross-sectional area is wound into a coil shape to form a coil-wound body 13; , the area from a position D displaced 90 degrees in the circumferential direction with respect to a specific position A in the circumferential direction of the coil wound body to another specific position G displaced 180 degrees with respect to the specific position A is defined as a predetermined area. In this predetermined area, the inner peripheral side portion 14b of the spring wire of each turn is shaved off. In this case as well, the spring constant at a specific position G within a predetermined area is smaller than the spring constant at a specific position A within another area, similar to the embodiment shown in FIG.

By reducing the diameter of the spring wire of each turn in a predetermined region in the circumferential direction of the coil winding body, the cross-sectional area of the spring wire of each turn in the predetermined region can be made smaller than that of each turn in other regions. It is conceivable to make it smaller than the cross-sectional area of the spring wire. However, in order to do this, before forming the coil winding body, a special spring wire in which large diameter parts and small diameter parts are arranged alternately at intervals commensurate with the winding diameter of the coil spring is manufactured in advance. Therefore, preliminary processing of the spring wire becomes extremely troublesome. In addition, in this case, it is necessary to prepare spring wires with different spacing between the large diameter part and the small diameter part for each coil spring with a different winding diameter. It cannot be manufactured efficiently.

On the other hand, if the cross-sectional area of each spring wire in a predetermined region is reduced by cutting the outer circumferential side or inner circumferential side of each turn of the coil winding body as described above, Since the cutting process can be performed after forming the coil winding body, there is no need to perform complicated preliminary processing on the spring wire, and regardless of the winding diameter of the coil spring, it can be cut in a predetermined area in the circumferential direction. It is possible to manufacture a coil spring in which the cross-sectional area of the spring wire is smaller than other regions.

Next, an application example of the above coil spring will be explained with reference to FIG. In the example shown in FIG. 4, a coil spring 1 according to the present invention is attached to an elastic support device c for attaching a processing tool a such as a welding torch to its drive device main body b.
This is an example in which 1 is applied.

The illustrated elastic support device c has a cylindrical frame f
A disc-shaped pressing plate g is slidably fitted into the frame f. Only one coil spring 11 according to the present invention is inserted into the frame f, and the coil spring 11 is arranged between the pressing plate g and the base e provided to close the opening of the frame f. There is. One seat portion 12 of the coil spring 11 is fitted into a groove provided in a pressing plate g, and is prevented from rotating by a stopper d. Also coil spring 1
The other seat portion 12 of the base plate 1 is fitted and positioned within a recess provided in the base e, and is prevented from rotating by a stopper d.

One end of an L-shaped support arm h is fixed to the pressing plate g, and a processing tool a is fixed to the other end of the support arm h.

The frame f and the base e are the main body of a drive device that moves the processing device with the processing tool a positioned downward and the axis of the coil spring 11 directed in the horizontal direction, as shown in the figure. It is fixed at b. In addition, in this state, the coil spring 11 is moved such that a specific position G in a predetermined area in the circumferential direction of the coil spring 11 is located above, and another specific position A, which is 180 degrees away from the specific position G, is located below. Positioned.

A detector (not shown), for example, a limit switch, is further housed in the frame f, and this detector is fixed to the base e, and is activated when the pressing plate g is displaced by a predetermined amount toward the base e. It's becoming like that.

The above elastic support device c is used, for example, to cushion the processing tool a when it collides with an obstacle or the like, and to stop the drive device to prevent damage to the processing tool a.

That is, the processing tool a is driven by the drive device main body b and moves in the direction of the arrow γ or δ shown in the figure to perform a predetermined processing, but if the processing tool a collides with an obstacle during its movement, the pressing plate g is displaced, so
A detector inside the frame is activated, and the detector gives a stop command to the drive device to stop the movement of the processing tool a.

In the above elastic support device c, when an external force Fγ′ in the direction of arrow γ is applied to the processing tool a at the tip of the support arm h, the external force is mainly applied to the coil spring 11 due to the structure.
It will act on a specific position A below. Also, at this specific position A, the dead weight W of the processing tool a is an external force
It has a positive effect on Fγ′. Therefore, the sum of the force acting on the external force Fγ' and the force acting on the processing tool a due to its own weight W acts as the bias load Fγ at the specific position A.

Further, when an external force Fδ' is applied to the processing tool a at the tip of the operating member h from the direction of the arrow δ, the external force mainly acts on a specific position G above the coil spring 11 due to the structure. Further, at this specific position G, the dead weight W of the processing tool a acts negatively on the external force Fδ'. Therefore, at the specific position G, a force obtained by subtracting the force applied by the dead weight W of the processing tool a from the force applied by the external force Fδ' acts as the bias load Fδ.

Therefore, in the above elastic support device c, if the magnitudes of the external force Fγ′ and external force Fδ′ acting on the processing tool a are equal, the self-weight W of the processing tool a is added to the external force Fγδ′.
acts positively, and the self-weight W acts negatively on the external force Fδ', so the biasing load Fγ acting on the specific position A of the coil spring 11 is large, and the biasing load Fδ acting on the specific position G of the coil spring 11 is small. Become.

In such a case, the coil spring 1 according to the present invention
1, the spring constant is large at a specific position A where a large bias load Fγ acts, and a small bias load
Since the spring constant is smaller at the specific position G where Fδ acts, the amount of deflection of the coil spring at the specific positions A and G can be made approximately equal.
Therefore, even when an external force Fγ' in the direction of arrow γ is applied to processing tool a, the arrow δ having the same magnitude as Fγ'
Even when an external force Fδ' in the direction is applied, the coil spring 11 can be deflected by the same amount to operate a detector such as a limit switch. That is, the detection sensitivity can be made equal no matter which direction an external force acts on the processing tool a.

[Effects of the invention] As described above, according to the invention, the outer peripheral part or the inner peripheral part of the spring wire of each turn is cut in a predetermined area in the circumferential direction of the coil wound body. Since the cross-sectional area of the spring wire of each turn in a predetermined region is smaller than the cross-sectional area of the spring wire of each turn in other regions, the spring constant in a predetermined region in the circumferential direction of the coil is It can be made smaller than the spring constant of the region, and when bias loads of different magnitudes are applied to a specific position G in a predetermined region in the circumferential direction of the coil and a specific position A in another region, each The amount of deflection of the spring at positions G and A can be made approximately equal. Therefore, when bias loads of different magnitudes are applied to different parts of a device using coil springs, it is necessary to make the amount of deflection at each part approximately equal, without using multiple coil springs. , can be applied independently and can contribute to simplifying the structure of the device and reducing costs.

Furthermore, in the coil spring of the present invention, by cutting the outer circumferential side or the inner circumferential side of the spring wire of each turn in a predetermined region of the coil wound body, regions with different spring constants are formed. After forming the coil-wound body, processing for forming regions having different spring constants can be performed, and manufacturing of the coil spring can be facilitated.

Furthermore, according to the present invention, since it is sufficient to perform the cutting process after forming the coil-wound body, there is also the advantage that a coil spring with an arbitrary winding radius can be manufactured efficiently and at low cost.

[Brief explanation of the drawing]

1A and 1B are a plan view and a vertical cross-sectional view showing the first embodiment of the present invention, respectively, and FIG. A graph showing the magnitude of the bias load applied to a position, Figures 3a and 3b are a plan view and a vertical sectional view respectively showing the second embodiment of the present invention, and Figure 4 is a graph showing the elasticity of the coil spring according to the present invention. FIGS. 5A and 5B are a longitudinal sectional view and a plan view, respectively, showing a conventional elastic supporting device using a coil spring. 11... Coil spring, 12... Seat, 13...
...Coil winding body, 14... Spring wire, 14a...
Outer circumference side portion of spring wire, 14b...Inner circumference side portion of spring wire, A, G...Specific position.

Claims (1)

[Scope of utility model registration request] The outer or inner portion of the spring wire of each turn is cut in a predetermined region in the circumferential direction of a coil wound body formed by winding a spring wire with a constant cross-sectional area into a coil shape. A coil spring characterized in that the cross-sectional area of the spring wire of each turn in a predetermined region is smaller than the cross-sectional area of the spring wire of each turn in other regions.