JPH0355702B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to improvements in shock absorbers used for stopping moving parts or moving objects in various machines.

<Conventional Examples and Problems> Conventionally, this type of shock absorber basically has a main body with a fluid chamber and an actuation rod that receives external force. Receive it at the tip of the
It uses the viscous resistance of liquid or gas and the squared resistance of velocity to absorb the moving energy of the colliding object and bring it to a soft stop.

In this case, as a means to return the reciprocating actuating rod to the position before external force is applied, a spring return method (Fig. 3) in which a spring S is mounted inside the main body, or a spring return method (Fig. An air return method (FIG. 4) is known in which an air cylinder 100 and a piston 110 are attached to the piston and an actuating rod is connected to the piston.

However, according to the former method, the spring force acting on the actuating rod 130 upon return becomes a reaction force that is generated immediately after the external force disappears and pushes back the stopped object, and the object often cannot be stopped at the set position. Particularly, if the object is a free-flow moving object, a separate mechanism such as a stopper to prevent back movement after stopping is required.

On the other hand, according to the latter method, the actuating rod 130
The return timing of the air cylinder 100 can be adjusted arbitrarily by controlling the operation of the air cylinder 100. However, since the piston rod 120 connected to the actuating rod 130 is inserted into the main body, an extra precision sealing member is required, and the movable parts are This increases the cause of fluid leakage.

Furthermore, the following problems are common to both.

That is, there is no problem when the direction of action of the external force coincides with the axial direction of the reciprocating actuating rod 130, but there is no problem when the direction of action is not strictly regulated, such as in the case of a free-flow transfer object. In this case, there will be more variation in the angle of impact with the tip of the actuating rod.

If the angle at which the external force is applied due to this collision is different from the direction of the proper reciprocating motion of the actuating rod, that is, the axial direction (hereinafter referred to as the "deviation angle"), the bending moment stress will be applied to the actuating rod. However, the actuating rod is bent and deformed, making it impossible to reciprocate, and the sealing portion between the actuating rod and the fluid chamber is damaged, resulting in malfunction of the shock absorber. In particular, in the case of small-sized shock absorbers, the operating rod is also thin, making the shock absorber less durable against the action of external forces at eccentric angles.

<Means for Solving the Problems> The present invention was proposed in order to eliminate the above-mentioned drawbacks, and its purpose is to adopt an air return method that can control the return timing of the actuating rod, and to The object of the present invention is to provide a shock absorber that is not connected to an actuating rod within the shock absorber, that is, does not require an extra seal structure.

Another object of the present invention is to provide a shock absorber capable of preventing the action of external bending moments on the actuating rod.

A further object of the present invention is to provide a shock absorber that allows adjustment of the stroke length of the actuating rod.

Still another object of the present invention is to provide a shock absorber capable of regulating external forces so that external forces other than the set maximum stroke length of the actuating rod do not act on it.

The object of the present invention is to provide an air return type shock absorber which is provided to receive external force from an actuating rod that protrudes outward from the main body and is capable of reciprocating movement.
It is a hollow cylindrical body with a threaded part formed on the outer periphery of the main body and both ends are open, and has a female threaded part for screwing on the inner wall thereof, and has an air vent penetrating from the outer peripheral surface to the inner wall. A guide member is provided to be able to be screwed into the main body at the female threaded portion, and a guide member is provided to be slidably inserted loosely into the guide member so that a part of the guide member can be protruded and retracted from the outside of the guide member, and a connection member is provided. a transmission rod connected to the actuation rod through a member, and an air return type shock absorber which is provided so that the actuation rod and the transmission rod can be returned to each other by air pressure supplied within the guide member. It will be achieved.

<Example> Next, the present invention will be explained in more detail according to an example shown in FIGS. 1 and 2.

Reference numeral 1 designates an air return type shock absorber body that utilizes the viscous resistance of the liquid sealed inside, and a threaded portion 11 is provided on the outer periphery of the shock absorber body.
Reference numeral 2 denotes an actuating rod inserted into the body 1 from one end thereof so as to be able to reciprocate. Reference numeral 21 denotes a pin hole formed through the vicinity of the tip of the actuating rod 2. Reference numeral 3 designates a guide member, which is formed into a hollow cylindrical body with both ends open, and is capable of being screwed into the main body 1 at a female threaded portion 32 formed on its inner wall. An air passage hole 31 is provided near the inner end. 4 is a transmission rod;
The guide member 3 is slidably inserted loosely into the guide member 3, and a portion of the guide member 3 protrudes and retracts from the opening of the guide member 3 so as to be able to reciprocate. Reference numeral 41 designates a pin hole drilled at a suitable location in the transmission rod 4, and has a slightly smaller diameter than the pin hole 21 of the actuating rod. 5 is a connecting pin, which is formed into a slightly tapered shape.
Numeral 6 is a nut that is screwed onto the threaded portion 11 of the main body 1 and locked at an arbitrary position.

FIG. 2 shows an assembly of the above-mentioned components. In this assembly, connecting pin 5
While press-fitting the rod into the pin hole 41, press the pin hole 2 of the actuating rod.
By inserting the rod into the rod 1, the actuating rod 2 and the transmission rod 4 are connected. Since the connecting pin 5 has a smaller diameter than the pin hole 21, the actuating rod 2 is connected with a slight degree of freedom, and under normal conditions, the transmission rod 4 has a tip portion near the outside of the guide member 3. It assumes a posture of protruding toward the direction and waiting for a collision with an object.
In the figure, reference numeral 7 denotes a ring-shaped stopper mounted on the inner surface of the guide member 3 in order to limit the limit of the intrusion stroke of the transmission rod 4. In addition, the connecting pin 5
It is an embodiment included in the present invention that the actuating rod 2 be connected to the transmission rod 4 by a known means such as by directly screwing the actuating rod 2 to the transmission rod 4 without using a connecting pin.

Here, when the object W or W' collides with the top of the transmission member 4 in the direction of the arrow, the transmission rod 4 receives the external force and slides downward, pressing the actuation rod 2 and pushing it down. At this time, the transmission rod 4 is guided by the guide member 3 so that its sliding direction always coincides with the axial direction of the actuating rod 2, so it will not collide with the object W' at an eccentric angle. The bending moment occurring in the transmission rod 4 is therefore not transmitted to the actuating rod 2.

Moreover, in this embodiment, the transmission rod 4
Since the actuating rod 2 and the actuating rod 2 are connected through the connecting pin 411 with a slight degree of freedom, the bending moment due to the eccentric angle collision does not affect the actuating rod 2 at all.

Therefore, regardless of the collision posture of the object, only the pressing force in the axial direction acts on the actuating rod 2, which prevents bending deformation of the actuating rod 2 and stress that has an adverse effect on the seal structure within the main body. This ensures proper reciprocating motion without any occurrence.

Further, by adjusting the screwing position between the guide member 3 and the main body 1, the protrusion length of the transmission rod 4, that is, the stroke length of the transmission rod 4 can be made shorter than the stroke length of the actuating rod 2. The nut 6 is used to securely hold and lock this screwed position. Due to this adjustment, even if an object collides with an excessive external force, the object will be stopped by the top end of the guide member 3 and will not press the transmission rod 4 any further. Therefore, the guide member 3 also has the function of preventing damage or deformation of the internal mechanism of the actuation rod 2 and the main body 1.

Next, after the stopped object W or W' is moved to another location by a transfer mechanism (not shown) or the like, when air is supplied into the guide member 3 at an appropriate pressure from the air vent 31, the transmission rod 4 is pushed up and returns to the position shown in FIG. 2, taking the position of waiting for the next object to collide.

<Effects> According to the present invention, the above-mentioned objects can be well achieved, and in addition to being easy to apply to an existing shock absorber and having high usability, there is also the advantage that the mechanism is simple and can be manufactured at low cost.

[Brief explanation of drawings]

Fig. 1 is an exploded perspective view of a shock absorber according to an embodiment of the present invention, Fig. 2 is a central longitudinal cross-sectional view showing its use, and Fig. 3 is a partially sectional front view showing a conventional example using a spring return method. FIG. 4 is a central vertical sectional view showing a conventional example using an air cylinder system. DESCRIPTION OF SYMBOLS 1... Main body, 2... Operating rod, 3... Guide member, 4... Transmission rod, 5... Connection pin, 31
...Air vent.

Claims (1)

[Scope of Claims] 1. An air return type shock absorber that is provided to receive external force by an actuating rod that protrudes outward from the main body and is capable of reciprocating motion, comprising: a threaded portion formed on the outer periphery of the main body; and a hollow portion that is open at both ends. A cylindrical body having a female threaded part for screwing on its inner wall, and an air hole penetrating from the outer circumferential surface to the inner wall, and the female threaded part is provided so as to be able to be screwed with the main body. a guide member; a transmission rod that is slidably inserted loosely into the guide member so that a portion of the rod can protrude and retract outside the guide member; and a transmission rod that is connected to the actuating rod via a connecting member; An air return type shock absorber which is provided so that the actuating rod and the transmission rod can be returned to their original positions by air pressure supplied into the guide member.