JP2513768Y2 - Shock absorber - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a shock absorber suitable for, for example, a die cushion of press equipment.

[Prior Art] In the example of the press equipment shown in FIG.
A die cushion d is used below the punch b and the blank presser c. The die cushion d is bent by an axial load applied at the time of pressing, and a repulsive force thereof causes a predetermined wrinkle pressing force or the like.

As the die cushion d, a metal wound spring such as a coil spring or an elastomer spring made of a rubber-like elastic body such as urethane has been usually used.

[Problems to be Solved by the Invention] Since the conventional die cushion using the coil spring has a small load capacity, a large number of coil springs must be used in parallel combination, in which case a mounting space is secured. It may not be easy. Further, since the coil spring alone does not have a damping property, it is difficult to quickly converge the vibration during pressing.

On the other hand, elastomer springs such as urethane tend to be easily set in physical properties, and therefore, when set in repeated use, settling often occurs. Further, there is a defect that deterioration is promoted by an external factor such as an ozone atmosphere and the spring function is impaired.
Moreover, the energy absorption performance is not so great.

Therefore, an object of the present invention is to provide a shock absorber which is compact, has a large load capacity and a large damping property, and does not cause performance deterioration due to external factors.

[Means for Solving the Problems] A shock absorbing device of the present invention developed to achieve the above object is a cylindrical case having an opening at least at one end side, and the shock absorbing device provided in the opening of the case and A pressure member that is movably held in the axial direction of the case and has a plunger portion that projects to the outside of the opening; retaining means that prevents the pressure member from slipping out of the opening of the case; A disc spring unit having a plurality of disc springs housed between the spring seat provided on the other end side and the pressure member and superposed in the thickness direction in the same direction, and a disc spring unit superposed in the opposite direction. It is equipped with.

The case, disc spring, spring seat, pressure member, etc.
Appropriate heat treatment is applied to enhance wear resistance and the like.

[Operation] When a load is applied in the axial direction through the plunger portion of the pressure member, each disc spring of the disc spring unit is pushed in the thickness direction by the pressure member, and the disc spring is pressed between the spring seat and the pressure member. Bends in the thickness direction. Therefore, a reaction force corresponding to the amount of bending is generated, and a damping force is generated due to a frictional force generated between the disc springs or between the disc springs and the pressure member to absorb energy. Therefore, the vibration generated during pressing is also quickly converged. When the load is removed, the pressure member returns to its original position by the repulsive force of the disc spring, and the frictional force generated at that time absorbs energy with hysteresis.

Since the disc spring unit can be housed in a state surrounded by a case, it can be used maintenance-free for a long time by providing an appropriate rust / lubrication means such as grease inside the case. In addition, the case also provides a dustproof effect.

[Embodiment] An embodiment of the present invention will be described below with reference to FIGS. 1 to 5.

As shown in FIG. 1, the shock absorber 1 of this embodiment includes a cylindrical case 2 having both ends open. Case 2
Is made of a metal such as carbon steel or stainless steel. The inner peripheral surface of the case 2 is subjected to heat treatment such as induction hardening or surface treatment such as chrome plating and nitriding treatment.
Wear resistance is enhanced.

A first female screw portion 4 is provided on the inner periphery of the lower end portion of the case 2, and a disc-shaped end member 5 is screwed into the female screw portion 4. The end member 5 is provided with a screw hole 6 penetrating in the axial direction, a screw hole 7 formed in the radial direction, and a male screw portion 8 screwed into the female screw portion 4.

An annular spring seat 10 is superposed on the inner surface of the case of the end member 5. The spring seat 10 has improved wear resistance by appropriate heat treatment or surface treatment. Spring seat
A center hole 11 is provided at the center of 10.

A pressure member 16 is provided in the upper opening 15 of the case 2. The pressure member 16 is held so as to be movable in the axial direction of the case 2. That is, the pressure member 16 has a disk-shaped base 17 located inside the case 2.
And a plunger portion 18 formed integrally with the base portion 17, and the plunger portion 18 projects to the outside of the opening 15 of the case 2. The outer diameter of the base 17 is slightly smaller than the inner diameter of the case 2. The pressure member 16 is also subjected to appropriate heat treatment to have improved hardness, wear resistance and the like.

A second female screw portion 21 is formed on the inner circumference of the opening 15 of the case 2, and a stopper ring 22 as an example of a retaining means for preventing the pressure member 16 from coming off is screwed into the female screw portion 21. Has been. A through hole 23 is provided in the central portion of the stopper ring 22, and the plunger portion 18 of the pressure member 16 is inserted into the through hole 23, and the end surface 18a of the plunger portion 18 projects outward from the end surface of the stopper ring 22. ing. Therefore, this pressure member 16 is
It is possible to reciprocate in the axial direction of the case 2 within the range of the stroke S shown in the figure.

A male screw portion 25 that is screwed into the female screw portion 21 is provided on the outer peripheral portion of the stopper ring 22. This stopper ring
The screw 22 is screwed to a predetermined axial position with respect to the case 2, and then fixed at a predetermined position by a spring pin 30 inserted in the radial direction. The hole 31 formed on the end face side of the stopper ring 22 along the axial direction is used for inserting a jig (not shown) for rotating the stopper ring 22.

Inside the case 2, the spring seat 10 and the pressure member
A disc spring unit 35 is housed between the disc spring 16 and the unit 16. The disc spring unit 35 is composed of a large number of disc springs 36,
These Belleville springs 36 are a plurality of upward Belleville springs 37 in which the central portion side is convex upward, and a plurality of the opposite disc springs are polymerized in opposite directions so that the central portion side is convex downward. The downward disc spring groups 39 are arranged alternately in the axial direction of the case 2.

Each disc spring 36 is provided in a state where an optimum initial deflection (initial setting load) is given by adjusting the screwing amount of the stopper ring 22 as necessary. It should be noted that each disc spring 36 may be housed in the case 2 in a state where no initial bending is applied.

The disc springs 36 have increased wear resistance and sag resistance due to heat treatment. Moreover, the spring characteristics of each disc spring 36 are designed so as to be within the permissible stress range even if the disc spring 36 is bent to a flat shape, and can be repeatedly used.

In addition, the case 2 is filled with grease,
The inner peripheral surface of the case 2, the disc springs 36, the spring seat 10, the pressure member 16 and the like are prevented from being worn and rusted. The grease may be contained in the case 2 when the shock absorber 1 is assembled, but in some cases, the grease may be contained in the case 2.
The grease may be supplied from a grease injection port provided in a part of the above or the end member 5 or the like.

A distribution port 45 is opened on the side wall of the case 2. This flow port 45 is provided inside the case 2 when the pressure member 16 moves in order to prevent the air inside the case 2 from acting as a gas spring when the pressure member 16 moves in the axial direction of the case 2. The air is allowed to go in and out. Therefore, the air flowing when the pressure member 16 moves can also suppress heat generation during movement.
A dustproof means such as a microfilter may be added to the circulation port 45 to withstand use in a dust atmosphere.

The shock absorber 1 having the above-described configuration is fixed to a pedestal 51 for fixing a die cushion such as a press facility by using a screw 50 as shown in FIGS. 3 and 4. Since the disc spring unit 35 is provided between the spring seat 10 and the pressure member 16 in the state where an initial load is applied, when the axial load is applied by a press or the like, as shown in FIG. , After the initial load P1 is exceeded, an apparent bending occurs, and thereafter, the bending increases as the load increases.

Then, in the unloading process in which the load is removed, the deflection decreases with hysteresis, so that energy is absorbed in the process. The disc spring unit 35 has a characteristic that the load is extremely large compared to the amount of bending in the axial direction, so that the allowable load is large even if the size is small in the load direction. Also, from the process of applying a load to the process of unloading,
A large damping force can be obtained by the frictional deformation resistance generated between the disc springs 36, 36 adjacent to each other and between the disc spring 36 and the pressure member 16, or between the disc spring 36 and the spring seat 10, and the like.

In the shock absorber 1 of this embodiment, the disc springs 36 forming the disc spring unit 35 are combined in parallel, that is, each disc spring group 3
Optimum load capacity as required by properly selecting the number of disc springs of 7,39 and the series combination, that is, the number of combinations of the first disc spring group 37 and the second disc spring group 39, etc. Can handle.

As shown in FIGS. 6 and 7, the shock absorber 1 is fixed to the flange member 61 by a bolt 60 screwed into the radial screw hole 7 of the case 2, and
The flange member 61 may be fixed to the pedestal 63 with bolts 62.

A shock absorber 70 according to another embodiment of the present invention shown in FIG.
The coil spring 71 having a rectangular cross section is inserted inside the disc spring 36 (inner diameter portion) so that the load capacity of the shock absorber 70 can be increased. In the case of this embodiment, the second spring seat 72 has the functions of adjusting the load capacity of the coil spring 71 and of positioning it. This coil spring 71 is
It may be made of a wire having a circular cross section, or a coil spring having a cross section other than the above may be adopted.

[Advantage of the Invention] According to the present invention, it is possible to obtain a large load capacity and energy absorption performance in spite of its small size, and to obtain a desired damping characteristic and load-deflection characteristic depending on the stacking direction, number and combination of the disc springs. To be

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of a shock absorber according to an embodiment of the present invention,
2 is a bottom view of the shock absorber shown in FIG. 1, FIG. 3 is a perspective view of the shock absorber shown in FIG. 1, and FIG. 5 and 5 are views showing load-deflection characteristics of the shock absorber shown in FIG. 1, and FIG. 6 is a perspective view showing another example of mounting the shock absorber shown in FIG.
FIG. 7 is a side view showing the shock absorber and the mount shown in FIG. 6 in a partial cross section, FIG. 8 is a vertical cross sectional view of the shock absorber showing another embodiment of the present invention, and FIG. 9 is a die cushion. It is a front view which shows the press equipment provided with in a partial cross section. 1 ... shock absorber, 2 ... case, 10 ... spring seat, 15 ... opening,
16 ... Pressure member, 18 ... Plunger part, 22 ... Stopper ring (prevention means), 35 ... Disc spring unit, 36 ... Disc spring.

Claims (1)

(57) [Scope of utility model registration request] 1. A cylindrical case having an opening at least on one end side, and a case provided in the opening of the case, movably held in the axial direction of the case, and protruding to the outside of the opening. A pressure member having a plunger portion, retaining means for preventing the pressure member from slipping out of the opening of the case, a spring seat provided at the other end of the case, and the pressure member, and A shock-absorbing device, comprising: a plurality of disc springs, which are superposed in the same direction in the thickness direction, and a disc spring unit, which is superposed in the opposite direction.