JPS5814933B2 - Nonlinear characteristic spiral spring and rotational force applying mechanism using it - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a nonlinear spiral spring and a rotational force applying mechanism using the same.

Note that the spiral spring here refers to a non-contact type spiral spring.

Conventional spiral springs are made by winding a strip-shaped material with a constant cross section so that its centerline forms a spiral on one plane, and uses the elastic deformation of bending by applying torque to one end of the spring as a spring action. It is.

However, with these conventional spiral springs, that is, springs with a constant spring constant, for example, when opening and closing the trunk lid of a car, the lid is slightly opened (in the initial stage) just by releasing the lock.
Ideally, if you apply an external force in the direction of opening, it will open with a small external force (middle stage), then in the next final stage it will open on its own, and when it is fully opened, the stopper will act to stabilize it. It is unsuitable for obtaining precise opening/closing operations, and the above-mentioned ideal opening/closing operations have often not been achieved due to friction in the mechanism or variations in spring characteristics.

In other words, as shown in Fig. 1, in a rotating member with a general spring constant constant spring and rotating torque port, the springing torque must be made stronger than the rotating torque in the C part of the usage range. Since there is friction, the above spring torque must be designed using a return force that takes friction into account.

On the other hand, in part B of the usage range, the return force of the spring must be designed to be weaker than the rotational torque, but since the return force of the spring is stronger in part C, the reaction causes the rotated member to move in part B. It is extremely difficult for one team to stop.

Therefore, in a typical spring with a constant spring constant, the allowable range of spring variation is relatively small, and if the spring torque is not adjusted individually, it will pose a practical problem, but adjusting the spring torque is extremely detailed.

Furthermore, in general spiral springs, the coils in the middle of the spring rotate while being in contact with each other, so the hysteresis is greater than that of other springs, so it is difficult to maintain the balance between the spring torque and the rotating torque of the rotated member during the return journey of the rotated member. There are some drawbacks that you can't do.

The spring variations referred to here include variations in the spring constant caused by variations in plate thickness, plate, etc., and variations in the free angles of the inner and outer ends of spiral springs, which are generally used after determining the set position. It was used as an inclusive concept.

Therefore, conventionally, a torque rod system as shown in FIG. 2 has been adopted as a mechanism for applying rotational force to the trunk lid of an automobile.

However, according to this torque rod system, the torque rods B and C reduce the effective space of the trunk throughout the entire vehicle inside the trunk, and the rotational force applied when opening and closing the trunk lid A is limited to the torque rods B and C. Therefore, it is difficult to suddenly increase the torque of the torque rods B and C at the final stage of the opening angle when the rotational moment of the trunk lid A becomes high. It had the disadvantage of being difficult to obtain.

Furthermore, in this torque rod method, the friction of the spring itself is very small, but when this method is used as the above-mentioned trunk lid rotational force applying mechanism, the torque rod does not only apply rotational torque, but actually rotates. Since rotational torque is applied while pushing the shaft in one direction, a considerable amount of hysteresis occurs, so when the trunk lid is closed, the balance between the rotational torque of the trunk lid and the spring torque of the torque rod is maintained. It also has the disadvantage that it is difficult to

This drawback can be improved to some extent by using hinges D, D, which are fixed at one end to the back surface of the trunk lid A, as a link mechanism, but this method is still not widely used because of the high cost.

This invention was made in view of the above circumstances, and the section modulus of the spring is changed continuously or stepwise in the longitudinal direction, and the smaller section modulus is set as the inner end, and when tightening, the section modulus is changed from the inner end. The structure is configured so that the effective length of the spring is reduced by closely contacting the winding core, and the spring torque is actively increased rapidly especially in the final stage of tightening, thereby reducing the rotational moment of the rotated member and the spring torque. It is an object of the present invention to provide a spiral spring with nonlinear characteristics that makes it possible to easily obtain an ideal relationship, and a rotational force applying mechanism using the spiral spring.

The present invention will be described in detail below based on Examples.

FIG. 3 is a front view of a non-linear characteristic spiral spring according to the present invention, and the spiral spring 1 is made of a long spring material that is spirally wound multiple times with gaps between them, and can be freely rotated by an appropriate means. It has an inner end hook part 1a that engages with a split groove 2a formed in a core bar 2 bolted to the core bar 2, and an outer end hook part 1b that is fixed to an appropriate fixing member (not shown). As shown in the figure, the width of the spring material is changed in stages, i.e., the narrow part 1C located at the inner end of the spring 1 and the wide part 1 located at the outer end.
It is composed of d.

Therefore, the section modulus of this spiral spring 1 is small on the inner end side and large on the outer end side.

The spring characteristics of this spiral spring 1 exhibit nonlinear characteristics as shown in FIG.

That is, in Fig. 3, the outer end 1b of the spring is fixed to an appropriate fixing member, and the core bar 2 is rotated in the tightening direction of the spring, and Fig. 5 shows the relationship between the deflection angle and torque. be.

As the deflection angle of the spring 1 advances by rotating the core bar 2 in the spring tightening direction, its torque increases approximately linearly, and at a certain deflection angle (the final stage of tightening) a, the inner end side of the spring 1 increases. As the spring 1 comes into close contact with the core metal 2, the effective length of the spring 1 decreases, and the torque of the spring 1 increases rapidly.

The deflection angle a at which the spring torque suddenly increases can be changed as appropriate depending on the composition ratio of the narrow width portion 1c and the wide width portion 1d in the entire spring 1, and is appropriately set according to the purpose of use.

In the above embodiment, the section modulus was changed by changing the plate width stepwise in the longitudinal direction of the spring, but the present invention is not limited to this, and the plate thickness may be changed stepwise. It goes without saying that all means for changing the section modulus can be applied, such as changing the section modulus by.

Therefore, since the nonlinear spiral spring according to the present invention has the above-described spring characteristics, even if the rotational moment of the rotated member increases when the rotated member is attached to the core metal, the torque of the spring will not suddenly increase. Therefore, an ideal relationship between the two can be easily established.

Furthermore, since the nonlinear spiral spring according to the present invention is forcibly brought into close contact with the core metal in sequence from the inner end as described above, the coils in the middle rotate while in contact, as is the case with general spiral springs. As a result, the friction of the spring itself can be reduced, the hysteresis of the spring can be reduced, and the ideal relationship between the rotational force and spring torque on the return path of the rotated member can be easily achieved. It is something that can be done.

Next, a rotational force applying mechanism using the non-linear characteristic spiral spring will be described in detail based on an embodiment.

The spiral spring 1 of the above embodiment will be used as the nonlinear characteristic spiral spring, and will be described using the same reference numerals.

FIG. 6 is a side sectional view of the rotational force applying mechanism, and FIG. 7 is a bottom view thereof.

3 is a core bar consisting of a cylindrical part 3a and a prismatic part 3b, and the cylindrical part 3
A has a split groove 3C and a groove 3e into which the snap ring 11 is fitted, and a prismatic portion 3b has a driving hole 3 for the spring pin 4.
d are formed respectively.

Reference numeral 5 denotes an outer case having a box-like cross section, and has an opening 5b on its upper side for taking out the outer end hook 1b of the spiral spring 1 to the outside. and one end of the opening I11EZ! The tongue piece 5c is bent outward to form a tongue piece 5c to which the hook part 1b on the outer end side of the spring 1 is fixed.

The spiral spring 1 has its inner end hook 1a inserted into the groove 3 of the core metal 3.
c, and the outer end side hook portion 1b is fixed to the tongue piece 5c of the outer case 5 with a rivet or the like.

5d is a screw hole.

Reference numeral 7 denotes a bottom case with a substantially n-shaped cross section that is extremely lower than the outer case 5, and a bearing portion 7 of the core metal 3 with a pusher 8 fitted on its upper side.
a, and grooves 7b, 7b, . . . into which the stopper 9 fits are formed on the outer peripheral edge of the upper side.

Reference numeral 7c is a screw hole, and the outer case 5 and the bottom case 7 are screwed together in alignment with the screw hole 5d of the outer case 5.

Reference numeral 10 denotes a disc-shaped set lever that is inserted into the square column portion 3b of the core metal 3 and moves integrally with the core metal 3, and has projecting sides 10a, 10a that engage with the stopper 9 on its outer periphery.

Therefore, the core metal 3 has a bearing part 5a of the outer case 5 into which the pusher 6 is fitted and a bearing part 7 of the bottom case 7 into which the pusher 8 is fitted.
a through the columnar section 3a, and fit the snap ring 11 into the groove 3e formed at the top of the columnar section 3a, while inserting the sling pin 4 into the hole 3d of the square columnar section 3b via the set lever 10. The axial direction is fixed to the outer case 5 and the bottom case 7.

Therefore, the core bar 3 is held rotatably without any braking action being applied in the winding direction or unwinding direction of the spiral spring 1.

In such a structure, the rotational force applying mechanism rotates the set lever 10 in the tightening direction of the spiral spring 1 to apply an initial torque to the spring 1, and the stopper 9 is inserted into the groove 7a of the bottom case 7.
The projecting piece 10a of the set lever 10 is engaged with the stopper 9 to prevent the core metal 3 and the spring 10 from rotating in the unwinding direction.

The magnitude of the above-mentioned initial torque is appropriately set depending on the rotation moment and rotation range of the rotated member.

When the rotation imparting mechanism is employed in the trunk lid shown in FIG. 2, the hinge D fixed to the trunk lid A,
The end of the core bar 3 of the rotational force applying mechanism, which is fixed in place in the trunk, is fixed to the rotation center of D.

By installing the rotational force applying mechanism in this manner, when the trunk lid A is opened or closed, the core bar 3 is rotated accordingly, and as a result, the torque of the spiral spring is increased or decreased.

FIG. 8 shows the relationship between the rotational moment of the trunk lid of this embodiment and the opening/closing position of the trunk lid.

Here ■ is the rotational moment characteristic of trunk lid A,
β indicates the spring characteristics of spiral spring 1, R indicates the opening/closing range of trunk lid A, S indicates the fully closed position of trunk lid A, and X indicates the set position of spring 1 and the fully open position of trunk lid A, respectively. show.

That is, FIG. 8 shows the relationship between the end of the core bar 3 and the trunk lid A of the rotational force applying mechanism to which an initial torque T is applied by rotating the core bar 3 by a predetermined angle in the winding direction of the spiral spring 1 having the spring characteristic β.
This figure shows the relationship between the rotation moment characteristic (■) of the trunk lid A and the spring characteristic (beta) of the spiral spring 1 when the rotation center of the hinge D is fixedly set at the fully opened position X.

First, in the initial stage R1 when the trunk lid A is slightly opened from the completely closed state (point S), the narrow width portion 1C of the spring 1 is in close contact with the core bar 3, reducing its effective length. As the constant increases, the torque of spring 1 increases rapidly, so the torque of spring 1 becomes larger than the rotational moment of trunk lid A.

In the middle stage R2 in which the opening angle of the trunk lid A is further increased, the torque of the spring 1 is slightly smaller than the rotational moment of the trunk lid A.

At the final stage R3, where the opening angle of trunk lid A is further increased from this stage until it is completely opened, the torque of spring 1 is larger than the rotational moment of trunk lid A because of the initial torque T. .

In other words, when trunk lid A is fully closed and unlocked, it opens slightly due to spring torque and stops near point Y (initial stage R1). It opens with a small external force (
This means that in the middle stage R2) and the next stage (final stage R3), the spring 1 will open on its own due to the initial torque T of the spring 1 and reach a fully opened state without applying any external force. Similar results were obtained in the example.

Note that when closing the trunk lid A, only a relatively small external force is applied at the beginning, since the rotational moment of the trunk lid A and the torque of the spring 1 maintain an appropriate ideal relationship over the entire opening/closing range of the trunk lid. The closing operation is easily completed.

The opening/closing operation described above is ideal for opening/closing the trunk lid of an automobile.

As mentioned above, the nonlinear characteristic spiral according to the present invention. The spring has a section modulus that changes stepwise or continuously in the longitudinal direction, and the smaller section modulus is the inner end, and the inner end is attached to a core metal that is rotatably attached in the tightening and unwinding directions of the spring. Since the structure is configured so that the effective length of the spring is reduced by adhering to the core metal from the inner end side during rotation in the core metal tightening direction, the spring effective length is reduced when the rotational moment of the rotated member is at its maximum. The ideal relationship with the rotational moment can be easily maintained by rapidly increasing the torque of the lever spring, and it can be particularly effective as an element of a rotational force imparting mechanism, and its practical value is low. It is enormous.

Still, using the above-mentioned nonlinear characteristic spiral spring according to the present invention,
The rotational force applying mechanism that applies initial torque to the spring can make the entire mechanism more compact than the conventional torque rod method, so when used as a trunk lid opening/closing mechanism, for example, it has the effect of securing sufficient effective space in the trunk. Not only does it provide excellent performance, it also provides ideal opening/closing operations and is inexpensive, making it of great practical value.

[Brief explanation of the drawing]

Fig. 1 is a characteristic diagram using a conventional spiral spring with a constant spring constant, Fig. 2 is a schematic illustration of a trunk lid using a conventional torque rond method, and Fig. 3 is a front view of a nonlinear characteristic spiral spring according to the present invention. Figure 4 is a plan view of the same as above before roll forming,
FIG. 5 is a spring characteristic diagram of the same as above, FIG. 6 is a side sectional view of the rotational force applying mechanism according to the present invention, FIG. 7 is a bottom view of the same, and FIG. 8 is a characteristic diagram of the same embodiment. 1... Spiral spring, 2, 3... Core metal, 5... Outer case, 7
...Bottom Pose, 9...Stopper, 10...Set lever, A...Trunk lid, B, C...Torque lock.

Claims (1)

[Scope of Claims] 1. A long spring material is wound spirally several times with a gap, its inner end is fixed to a core metal, its outer end is fixed to an appropriate fixing member, and the above-mentioned inner end is fixed to a fixing member. In a non-contact type spiral spring where the effective length of the spring is between the end and the outer end, the spring material whose section modulus changes stepwise or continuously in the longitudinal direction is used, with the smaller section modulus on the inner end side. A spiral spring with nonlinear characteristics, characterized in that when the core metal is rotated in the spring tightening direction, the core metal comes into close contact with the core metal from the inner end side to reduce the effective length. 2. A long spring material is wound spirally several times with gaps, its inner end is fixed to a core metal, its outer end is fixed to an appropriate fixing member, and the inner end and outer end are fixed. In a non-contact type spiral spring where the effective length of the spring is set between When the spring is rotated in the tightening direction of the spring, the inner end comes into close contact with the core metal to reduce the effective length, and when the core metal is rotated in the tightening direction of the spiral spring, an initial torque is applied to the core metal. A rotating force applying mechanism using a non-linear characteristic spiral spring, characterized in that a rotated member is connected to the core metal in a state in which the rotational force is applied. 3. The above-mentioned long material is constructed so that its thickness is constant in its longitudinal direction, its width is changed stepwise or continuously, and its section modulus is changed stepwise or continuously. A spiral spring with nonlinear characteristics as described in Range 1. 4. Claims characterized in that the elongated material is configured such that the thickness is constant in the longitudinal direction, the width of the board is changed stepwise or continuously, and the section modulus thereof is changed stepwise or continuously. Rotational force applying machine 9 using a nonlinear characteristic spiral spring described in Section 2