JPH03186628A - Air damper for conveying apparatus - Google Patents

Abstract

PURPOSE:To obtain a sure damper effect without a spring and an oil seal material by providing two air reservoirs, at least one of which is air-tight, on both sides of a piston in a cylinder chamber and disposing a labyrinth groove on the outer peripheral surface of the piston. CONSTITUTION:A piston 15 of a piston side member 11 is internally fitted in a cylinder tube 2 of a cylinder side member 1. A piston rod 12 screw-engaged with the piston 15 is pierced through a rod cover 8 to be connected to a knuckle 18. A labyrinth groove 23 is provided on the outer peripheral surface of the piston 15. In a cylinder chamber 24, an air reservoir 24a between the piston 15 and a head cover 5 is of an air-tight structure, and an air reservoir 24b between the piston 15 and a rod cover 8 is not of an air-tight structure. When both members are relatively moved to compress the air in the air-tight air reservoir, the fluid resistance is increased by the labyrinth grove so as to obtain a strong air cushion effect. Furthermore, a maintenance work is not required because a spring and an oil seal are not used.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention is used to reduce the impact that a conveyance device that moves guided by a guide rail receives when it is stored or stopped at a fixed position by a stopper. This invention relates to an air damper for use in a conveying device.

(Prior Art and its Problems) For example, a conveyance movable body movably supported along a guide rail and a leading trolley disposed in front of the conveyance movable body are connected by a load par, and the In a conveyance device in which the conveyance moving body is propelled by engaging a movable dog provided on the trolley with a pusher on the drive conveyor chain side, a stopper causes the movable dog of the leading trolley to engage with the pusher on the drive conveyor chain side. The movable dog of the leading trolley is detached from the pusher by a cam provided at the rear end of the conveying movable body stopped at the storage line, or when the movable conveyance body is stopped at a fixed position by detaching from the storage line. When the following conveyance movable bodies are sequentially stopped, a large impact acts on the conveyance movable bodies. In order to eliminate or alleviate various inconveniences caused by this impact, such as damage to various parts of the transport device, adverse effects on the transported objects, noise, etc.
As described in Japanese Utility Model Application Laid-Open No. 64-30773, it has been considered to interpose a buffer damper in the load bar that connects the leading trolley and the conveyance moving body.

However, as described in the above-mentioned publication, a conventional damper for a conveyance device has a spring interposed between a cylinder-side member and a piston-side member fitted therein, and the biasing force of the spring is applied to both the cylinder-side member and the piston-side member. This is a so-called spring damper in which the members are held in a neutral state, and when an impact force in the axial direction is applied, both the members contract and move against the biasing force of the spring.

When using such a conventional spring damper, if the biasing force of the spring is too strong, the two members will not be stabilized in a contracting state against the biasing force of the spring, and the repulsive force of the spring will cause Since both members are extended again and the conveying movable body moves backward, the stopping position of the conveying movable body is not constant.

In addition, in the storage line, each conveying moving body that has already stopped vibrates back and forth every time a subsequent conveying moving body collides with the rear end of the line, causing damage to the transported objects. Negative effects occur.

On the other hand, if the biasing force of the storage is too weak, the desired shock-absorbing effect cannot be obtained, making it extremely difficult to select a spring and making it difficult to put it into practical use.

Of course, in order to eliminate the above-mentioned inconvenience, a ura is enclosed in the cylinder chamber, and as the piston moves, oil is transferred from one side of the oil reservoir on both sides of the piston to the other via a small diameter oil passage provided in the piston. It is also known to use a so-called oil damper that allows oil to flow, but this requires an oil-tight structure to eliminate oil leakage, which not only complicates the structure and increases cost. Maintenance work such as periodic inspections for oil leaks, etc. is also required. Furthermore, the viscosity of the oil may change depending on the ambient temperature at the place where it is used, and the desired shock-absorbing effect may not be obtained, which limits the places where it can be used.

(Means for Solving the Problems) In order to solve the conventional problems as described above, the present invention has the following features:
A piston provided at the inner end of the piston side member is fitted into a cylinder chamber provided in the cylinder side member so as to be able to reciprocate in the axial direction, and a spring is not interposed to bias both members in the extension direction or compression direction. At least one of the two air pockets on both sides of the piston in the cylinder chamber is configured to be airtight, and no sealing material for maintaining airtightness is fitted on the outer peripheral surface of the piston, and air pockets are formed at appropriate intervals in the axial direction. The present invention proposes an air damper for a conveyance device that has a labyrinth groove formed therein.

(Example) An example of the present invention will be described below based on the attached illustrative drawings.

In FIGS. 1 and 2, l is a cylinder side member, which includes a cylinder tube 2 and a head cover 5 airtightly connected to one end of the cylinder tube 2 via a screw fitting part 3 and a cylinder gasket 4. , a rod cover 8 airtightly connected to the other end of the cylinder tube 2 via a screw fitting part 6 and a cylinder gasket 7, and a set screw 9 fitted externally to the free end of the rod cover 8.
The protective cover 10 is connected with the protective cover 5, and the connecting hole 5a is provided in the protective cover 5.

Reference numeral 11 denotes a piston side member, which includes a piston rod 12 that passes through the inside of the rod cover 8, and is fitted into the cylinder tube 2 and connected to the inner end of the piston rod 12 with a screw fitting part 13 and a set screw 14. and a knuckle 18 that is connected to the outer end of the piston rod 12 via a screw fitting part 16 and a set screw 17. A bushing 19 that guides the coil scraper 20 at a position adjacent to the outside of the bushing 19.
is fitted. Further, a stopper ring (collar) 21 is loosely fitted to the piston rod 12 between the knuckle 18 and the rod cover 8, and a connecting hole 18 is provided in the knuckle 18.
A is provided.

As shown in FIG. 3, the piston 15 is configured so that the gap 22 between it and the inner circumferential surface 2a of the cylinder tube 2 is as narrow as possible within the range in which the piston 15 can smoothly reciprocate without any hindrance. and on its outer peripheral surface 15a,
A plurality of labyrinth grooves 23 are formed at appropriate intervals in the axial direction.

FIG. 1 shows a state in which the cylinder side member l and the piston side member 11 have moved relative to each other in the axial direction to the contraction limit position. The piston 15 is located at the end of the cylinder chamber 24 formed by the cylinder tube 2, the head cover 5, and the rod cover 8 on the head cover 5 side.

FIG. 2 shows a state in which the cylinder side member l and the piston side member 11 have moved relative to each other in the axial direction to the extension limit position, and in this state, the piston 15 is moved toward the rod cover 8 side in the cylinder chamber 24. The inner end of the piston 15 is in contact with the inner end of the rod cover 8 .

That is, the cylinder side member 1 and the piston side member ll are
It can expand and contract in the axial direction as the piston 15 moves within the cylinder chamber 24, but the head cover 5 side of the cylinder chamber air reservoir 24a between the piston I5 and the head cover 5 has an airtight structure as described above. Therefore, when an external force is applied between the members 1 and 11 so that the members 1 and 11 rapidly contract from the extended state shown in FIG. 2 to the contracted state shown in FIG. Accumulation 2
The air in 4a flows to the cylinder chamber air reservoir 24b between the piston 15 and the rod cover 8 via the gap 22 between the outer circumferential surface 15a of the piston 15 and the inner circumferential surface 2a of the cylinder tube 2. It turns out.

At this time, the gap 22 is formed to be sufficiently narrow, and the air flowing through the gap 22 repeatedly expands within each labyrinth groove 23 and flows while being accompanied by a pressure change. The air flow resistance of the entire air passage (gap 22) is extremely large. Therefore, the air in the air reservoir 24a is rapidly compressed and functions as an air cushion, and then, as the air flows through the gap 22 to the air reservoir 24b, both members 1.11 slowly move. This results in a contraction movement.

Note that the rod cover 8 side of the cylinder chamber air reservoir 24b between the piston 15 and the rod cover 8 does not have a special airtight structure, so it can be moved from the contracted state shown in FIG. 1 to the extended state shown in FIG. 2. When an external force acts between both members 1.11 so that both members 1.11 rapidly extend, most of the air in the air reservoir 24b escapes to the outside from the space surrounding the piston rod 12. Air is sucked from the air reservoir 24b side through the gap 22 into the air reservoir 24a which is not compressed and has a negative pressure. Therefore, both members l.

In the direction in which 11 extends, almost no air cursion effect is obtained. However, a suitable airtight sealing material is interposed between the piston rod 12 and the rod cover 8]
7. Preliminary statement? If the rod cover 8 side of the air reservoir 24b also has an airtight structure, it is possible to obtain the same air traction effect in the direction in which both members 1.11 extend as in the direction in which they contract.

Of course, depending on the application, it is also possible to configure the structure so that the air traction effect is obtained only in the direction in which both members 1.11 extend.

Next, an example of the use of the air damper will be explained based on FIGS. 4 and 5.

25, the conveyed object support stand 26 is connected to a pair of front and rear trolleys 27.
．． 28, which is movably supported on the guide rail 29, and the front and rear trolleys 27 and 28 are connected to the leading trolley 3 via load pars 30 and 31, respectively.
2 and the rear end trolley 33 are connected, and the leading trolley 32
is provided with a movable dog 35 that can swing up and down around a support shaft 34 and is stabilized at the lower limit position by its own weight. The movable dog 35 is connected to its tip cam driven part 3.
A cam 36 for stopping the subsequent moving body is provided which is moved upward via the cam 5a.

However, below the guide rail 29, a conveyor chain for driving is provided with pushers 37 at appropriate intervals.
Guide rails 38 for guiding via the trolley are arranged in parallel, and by engaging the pusher 37 with the movable dog 35, the conveyance moving body 25 can be propelled.

In the above-mentioned conveyance device, the leading trolley 32
The air damper 39 is incorporated into the load par 30 that connects the air damper 39. That is, as shown in FIG. 4, a cylindrical body 42 having a U-shaped connecting member 41 at one end that fits into the connected portion 32a on the leading trolley 32 side and is connected by a joint bolt 40 is provided with a cylindrical body 42 having a U-shaped connecting member 41 at one end. As shown, the air damper 39
The cylinder side member I and the cylindrical body 42 are connected by a joint bolt 43 passed through the cylindrical body 42 and the connection hole 5a of the herad cover 5, and the cylinder The U-shaped connecting member 44 attached to the front trolley 27 of the transport moving body 25 is fitted onto the knuckle 18 of the piston side member 11 protruding from the free end of the body 42, and the attachment is done through the hole 18.
The two are connected by a joint bolt 45 passing through a.

In addition, as shown in FIG.
and a fitted portion 46 having a slightly larger diameter than the outer diameter of the protective cover 1O and finished with an inner diameter that allows the rod cover 8 to fit tightly therein.
is formed over an appropriate length from the free end of the cylindrical body 42, so that the air damper 39 is reliably supported concentrically with respect to the cylindrical body 42 by tight fitting between the fitted portion 46 and the rod cover 8. Therefore, when compressive force is applied to the load par 30, the cylindrical body 42 and the air damper 39
The joint bolt 43 is configured to be prevented from being bent using the joint bolt 43 as a fulcrum.

By incorporating the air damper 39 into the load par 30 as described above, a tensile force is applied to the load par 30 when the pusher 37 is propelling the transport moving body 25, so that the cylinder side member l of the air damper 39 and the piston side A tensile force also acts between the member ll,
As shown in FIG. 2, the air damper 39 is in an extended state to the maximum extension position. At this time, the leading trolley 32
The traction force acting on the cylinder body 42 → joint bolt 43 → air damper 39 head cover 5 → cylinder tube 2 → rod cover 8 → piston I5 → piston rod 12 → knuckle 18 → joint bolt 45 → front trolley 2
7 will be reliably transmitted.

However, as is well known in the art, a movable dog 3 is provided with a stopper that can move in and out and has the same function as the cam 36 for stopping the following moving body.
5, the movable dog 35
When the conveyance movable body 25 is stopped at a fixed position by moving upward and separating from the pusher 37, a part of the movable stopper collides with the leading trolley 32; The axial compressive force will act rapidly. Also, in the storage line, when sequentially stopping the conveying moving bodies 25 using the subsequent moving body stopping cam 36, the 2nd delusion of 9q in front of the stop-1,7LN Last name Toro +1-33 and the leading trolley 32 of the rear transportation moving body 25 that is stopped
This results in a collision, and at this time as well, an axial compressive force is rapidly applied to the load par 30 as described above.

When the axial compressive force suddenly acts on the load par 30 as described above, the axial compressive force also acts on the air damper 39, causing the cylinder side member 1 and the piston side member 11 to move to the contraction limit position in the axial direction. At this time, as described above, the air damper 39 absorbs the shock caused by the sudden axial compressive force, and the transport moving body 25 can be stopped with less shock.

In addition, as explained above, when the air damper 39 is configured so that the air traction effect can be obtained even against the axial tensile force, the air damper 39 is lowered to start the stopped transport moving body 25. Movable dog 35 returned to the limit position
The impact caused when the pusher 37 is engaged can also be absorbed by the air damper 39.

As described above, according to the air damper for a conveyance device of the present invention, a spring that biases the cylinder side member and the piston side member in the extension direction or the compression direction is not interposed. , at least one of the two air pockets on both sides of the piston in the cylinder chamber is configured to be airtight, and when the two members move relative to each other in a direction that compresses the air in the air pocket of this airtight structure, the piston When the air in the air reservoir escapes to the opposite side of the piston through the gap between the outer peripheral surface of the piston and the inner peripheral surface of the cylinder, the air in the air reservoir is compressed by the flow resistance, thereby creating an air traction. Therefore, the air cursion effect can reliably alleviate the impact when an external force in the axial direction in the direction of compressing the air in the air pocket of the airtight structure is suddenly applied between the two members. Nevertheless, both the members can be finally stabilized in a contracted state to the contraction limit position or in an extended state to the extension limit position.

Moreover, since springs and oil are not used, maintenance work such as inspection, replacement, and repair of these springs, oil, and oil-tight sealing materials is completely unnecessary, and it can be maintained as expected for a long period of time in any environment. It is possible to reliably obtain a damper effect.

In addition, the gap between the outer peripheral surface of the piston and the inner peripheral surface of the cylinder chamber, which serves as an air passage, must be made as narrow as possible, but there are limitations in processing technology, and it is difficult to maintain the necessary air flow resistance in the gap. Although it is very difficult to obtain this, according to the present invention, by forming labyrinth grooves on the outer peripheral surface of the piston at appropriate intervals in the axial direction, it is possible to increase the air flow resistance of the entire gap. In other words, even if the gap is as wide as can be reasonably realized from the viewpoint of processing technology, it is possible to produce the same air flow resistance as when the gap is made narrower, so it is easy to manufacture. However, it is possible to exert a strong and reliable air traction effect.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional plan view in a contracted state, Fig. 2 is a partial cross-sectional plan view in an expanded state, and Fig. 3 is an enlarged cross-sectional plan view of the same main part.
FIG. 4 is a side view showing an example of the state of use, and FIG. 5 is a partially longitudinal side view illustrating the main parts thereof. DESCRIPTION OF SYMBOLS 1... Cylinder side member, 11... Piston side member 12... Piston rod, 15... Piston, 22
... Gap, 23... Labyrinth groove, 24... Cylinder chamber, 24a, 24b... Air pool.

Claims (1)

[Claims] A piston provided at the inner end of the piston side member is fitted into a cylinder chamber provided in the cylinder side member so as to be able to reciprocate in the axial direction, and a spring is not interposed to bias both members in the extension direction or compression direction. At least one of the two air pockets on both sides of the piston in the cylinder chamber is configured to be airtight, and no sealing material for maintaining airtightness is fitted on the outer peripheral surface of the piston, and air pockets are formed at appropriate intervals in the axial direction. An air damper for conveyance equipment that has a labyrinth groove formed therein.