JPH01224537A - Spring gear - Google Patents

Abstract

PURPOSE:To realize negative characteristic and constant load characteristic except positive characteristic of a spring, by providing a spring, a magnet, a moving member which moves in the working range of the spring, and a limiting member having a magnetic substance and provided at the moving end of the moving member. CONSTITUTION:At the starting end of movement of a moving member 2 and in a prescribed range of movement from this end, magnetic attraction does not act, and a total spring gear has positive characteristic which the load increases according to increase of the deflection. Next, when a magnet 5 becomes close to a limiting member 3 as further movement of the moving member 2, and magnetic attraction acts between them, the total gear has positive characteristic combined with magnetic attraction characteristic. As both characteristics have reversely positive and negative gradient, deflection of a spring 1 can be performed with a constant additional pressure in the total gear by properly selecting the spring 1. When the magnet 5 is close to the limiting member 3 by continuing the additional pressure, the magnetic attraction between them increases with a steep slope, and as the result, the total gear has negative characteristic which the load decreases even with increase of the spring deflection.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a spring device that embodies properties other than the positive properties of a spring.

[Prior art and its problems] Generally, the relationship between spring load and deflection is expressed by a spring constant. With some exceptions, this spring constant has a positive characteristic in that as the deflection increases, the load also increases, and springs are assembled into various industrial equipment by taking advantage of this positive characteristic. The negative characteristic, that is, the characteristic that the load decreases as the deflection increases, cannot be obtained by a spring alone, and it has been impossible to embody the negative characteristic and put it to industrial use. However, in disc springs or springs with snap action, negative characteristics occur within a very limited range of the entire operating stroke, but this range is not only extremely narrow, but also when used beyond this range. Since the spring will not return to its original position, it cannot be put to practical use at all.

Therefore, the present invention is a novel method that embodies the negative characteristics and constant load characteristics of springs other than the positive characteristics, and also makes it possible to adjust the characteristics, thereby making it possible to effectively utilize the characteristics in a wide range of fields. The purpose of the present invention is to provide a spring device.

[Means for Solving the Problems] In order to achieve the above object, the present invention includes a spring, a moving member having a magnet and moving within the operating range of the spring, and a moving member having a magnetic body and moving the moving member at the end of the movement of the moving member. It is characterized by comprising a restriction member provided in the.

[Function] In the above configuration, when the movable member approaches the limiting member, a magnetic attraction force acts between them, and this magnetic attraction force and the load for the deflection of the spring are combined, so that the entire device is corrected. operates with characteristics other than those of .

[Example] FIG. 1 is a side view showing an embodiment of the present invention.

A spring device includes a spring 1 made of a compression spring, a moving member 2 provided at the upper end of the spring 1, and a limiting member 3 provided at the lower end of the spring 1. The spring 1 is wound at a uniform pitch. The moving member 2 includes a main body 4 having a flange portion 4b abutted against the spring 1, and a magnet 5 attached to the main body 4. The main body 4 has a cylindrical leg 4a that hangs down within the spring l, and a magnet 5.
is fitted into this cylindrical leg portion 4a. Further, the upper surface of the main body 4 is a pressure-receiving part, and when force is applied to this upper surface, a pressing force is applied to the spring 1 from the flange portion 4b of the main body 4, so that the spring 1 is bent in the direction of the pressing force. There is. Therefore, when the movable member 2 is pressurized, the movable member 2 moves in the pressurizing direction while bending the spring 1. In this case, the lower end of the leg portion 4a of the main body 4 is open, and the magnet 5 is exposed. The limiting member 3 is provided at the lower end of the spring 1, supports the lower end of the spring 1, and the spring receiver also serves as a seat and serves as the end of the movement of the moving member 2. The entirety or at least the portion of the limiting member 3 facing the moving member 2 is made of a magnetic material, and the moving member 2
When the moving member 2 approaches the moving member 2, a magnetic attraction force acts between the moving member 2 and the magnet 5. Since the direction of the load is opposite to the direction of the load due to the deflection of the magnetic attraction spring 1, the characteristics of the entire device in which these are combined can be other than positive characteristics.

Next, the operation will be explained.

The amount of deflection of the compression spring 1 increases or decreases in proportion to the pressing force from the moving member, and as the amount of deflection increases, the biasing force (that is, the restoring force) against the load increases. Further, the magnetic attraction force between the magnet 5 of the moving member 2 and the limiting member 3, which is a magnetic material, is inversely proportional to the distance between them. In this embodiment, the moving member 2 is provided so that no attractive force is applied at the start end of its movement, and the magnetic attractive force is applied from the middle of the movement of the moving member 2. FIG. 2 shows these characteristic diagrams, and the characteristic curve A is the deflection-load curve of the compression spring 1, and its slope is the spring constant (positive). The characteristic curve B is a curve of the magnetic attraction force acting between the magnet 5 of the moving member 2 and the limiting member 3. In this case, since the magnet 5 is inserted into the compression spring 1 and provided within its operating range, when the compression spring 1 is deflected, the moving member 2
moves in the direction of the limiting member 3, and the distance between them decreases. Therefore, the amount of deflection of the spring, which is the horizontal axis, is at the same time the limiting member 3, which is a magnetic material, and the moving member 2, which has the magnet 5.
It is the distance. In this case, the spring force against the deflection of the donkey spring l due to the movement of the moving member 2 is in the upward direction, while the magnetic attraction force between the magnet 5 of the moving member 2 and the limiting member 3 is in the downward direction. A characteristic curve C, which is a composite of these forces, is the characteristic of the entire device. Further analysis of this characteristic curve shows that no magnetic attraction force acts at the starting end of the movement of the moving member 2 and within a predetermined movement range, and only the spring force with respect to the deflection of the spring 1 is the characteristic of the entire device. Therefore, until the magnetic attraction force is applied, the device as a whole has the same characteristics as characteristic curve A, that is, a positive characteristic in which the load increases as the deflection increases. Next, when the moving member 2 moves, the magnet 5 approaches the limiting member 3, and a magnetic attraction force acts between them, the entire device aligns the characteristic curve A of the spring l with the magnetic attraction characteristic curve B. It has a unique characteristic. And these characteristic curves A and B
Since the gradient is opposite in positive and negative, the entire device branches from the characteristic curve A to form a characteristic region C3. Here, if an approximate characteristic curve is obtained from the characteristic curve B and a spring 1 having an opposite slope with the same absolute value as the slope of this characteristic curve is adopted and used, the characteristic area of the characteristic C of the entire device is CI has constant load characteristics where the load is constant. Therefore, in the entire device, the spring 1 can be deflected with a constant pressing force. When this pressurization is further continued to bring the magnet 5 and the restricting member 3 closer together, the magnetic attraction between them increases at a steep gradient, so the load on the device as a whole decreases even if the amount of deflection of the spring increases. It shows negative characteristics. Characteristic region C2 shows this negative characteristic.

In the above-described operation, the characteristics of the entire device can be adjusted as desired by appropriately changing the magnetic attraction force of the magnet 5 and the spring constant of the spring 1, and the device can be applied according to the application equipment.

FIG. 3 is a characteristic diagram in which a compression spring with two unequal pitches is used as the spring 1. As the compression spring with the unequal two-stage pitch, one whose spring constant has the same absolute value as the approximate characteristic curve obtained from the magnetic attraction force characteristic curve B can be selected. That is, with respect to the characteristic parts D1 and D2 of the characteristic curve B, there is a coil part (characteristic part AI) having a spring constant having a slope opposite to that of the characteristic part RI, and a coil having a spring constant having a slope opposite to that of the characteristic part D2. By using a spring having a portion (characteristic portion A2), it is possible to obtain a device having constant load characteristics in which the characteristic curve C as a whole is flat. In addition, in the case of springs having not only such an unequal two-step pitch but also an unequal three-step pitch or other pitches, it is possible to make the device have constant load characteristics by the same means as described above, and also The accuracy of constant load characteristics can be improved by increasing the number of pitches.

Note that the present invention is not limited to the above-described embodiments, and various modifications can be made. Spring Instead of a compression spring, it is also possible to use a torsion spring or a spiral spring, in which case the limiting element is arranged at the end of the spring's action end.

[Effects of the Invention] As explained above, the present invention includes a magnet in a moving member that moves within the operating range of a spring, and a magnetic body at the end of the movement of the moving member to prevent the spring from responding to these magnetic attraction forces and deflections. By combining the loads of be able to. Furthermore, the pattern of the characteristic curve can be changed as appropriate, making it possible to create a spring device that exhibits characteristics that can be applied over a wide range of applications.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an embodiment of the present invention, FIG. 2 is a deflection-load characteristic diagram thereof, and FIG. 3 is a deflection-load characteristic diagram of another embodiment. 1... Spring, 2... Moving member, 3... Limiting member, 5... Magnet. Patent applicant NHK Spring Co., Ltd. Agent Patent attorney Hide Sato Showa 3

Claims (1)

[Claims] A spring device comprising: a spring; a moving member having a magnet and moving within an operating range of the spring; and a limiting member having a magnetic body and provided at a movement end of the moving member.