JPS645173B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a stay damper used for opening and closing the back doors and engine hoods of automobiles, for opening and closing windows, and for lifting and lowering chairs and tables.

Generally, in automobiles, stay dampers 4, 4 using gas springs are interposed between the car body 1 and the back door 2 or engine hood 3, as shown in Fig. 1. Normally, the spring expands due to the gas pressure and supports the load of the door 2 or hood 3 to maintain the open state.

However, the conventional stay damper 4 for opening and closing the back door or engine hood utilizes repulsive force to maintain the supporting force only by gas pressure when the door 2 or hood 3 is opened. If wind pressure is applied to the door 2 or hood 3 when opened, or when loading or unloading luggage at the back of the car,
If an object collides with the stay damper 4 during other work, the gas sealing inside the stay damper will be rapidly impaired, causing the gas to leak and causing the door 2 and hood 3 to fall under their own weight, creating the risk of getting a part of your body caught. . Furthermore, if the seal becomes defective and gas escapes during long-term use, the door 2 or hood 3 may fall and pinch your hand, or pose a danger to your body. Therefore, the stay damper 4 is required to have a locking function during extension in addition to the rod reaction force caused by the gas pressure.

In addition, at the initial stage when the door 2 or the hood 3 is opened, the door 2 or the hood 3 opens immediately, and the door 2 or the hood 3 opens immediately.
If the door 2 and hood 3 do not decelerate and stop appropriately when they are fully open, the door 2 and hood 3 will rebound, which is dangerous, so a deceleration function is also required when the rod is extended.

Furthermore, the piston rod protrudes from the cylinder when the stay damper 4 expands and contracts, and if it is left exposed, the piston rod may be damaged or dirt may adhere to it, so it is also required to protect the rod.

As a stay damper 4 that satisfies such requirements. For example, the one shown in Fig. 2 is known.

A piston rod 7 is slidably inserted into the cylinder 5 via a piston 6, and the piston rod 7 is fitted with a cushion 8, a seal 9, and a bearing 1.
The cylinder 5 is provided with an oil chamber 11 partitioned by a piston 6 and a gas chamber sealed with gas at a position facing the oil chamber 11. is attached to the vehicle body side via the bracket, and the piston rod 7 is attached to the bracket 12.
It is connected to the back door 2 or the engine hood 3 via.

In this case, in order to satisfy the locking function during extension,
A hook member 13 is provided at the end of the piston rod 7,
When the stay damper 4 is fully extended, it can be locked by being hooked to the cushion 8. Also, in order to satisfy the rod extension deceleration function, the piston 6 is provided with a damping mechanism 14 consisting of an orifice or a valve. A cylindrical cover 15 is attached to the outer periphery to prevent the rod from being scratched and dust from adhering to it.

However, in the above-mentioned stay damper 4, it is necessary to assemble a special mechanism such as a hook member 13 as a means for locking at the most extended position, and since this mechanism is provided inside the cylinder 5, it is difficult to maintain the locked state. It has the disadvantage that it is not possible to confirm the stroke, and it is very difficult to set the damping orifice and valve for decelerating near the end of extension, as well as the pressure of the filled gas and the rod repulsion force.

Furthermore, in the conventional opening/closing device for the back door 2, it is always urged in the extension direction by the repulsive force of the gas spring, and when the back door 2 is unlocked, the piston rod 7 is fully extended by this repulsive force, and the back door 2 is fully opened. do. However, on rainy days, strong winds, etc., it may be better to load and unload cargo with the back door 2 partially open, but there is no known means for meeting such requests with conventional opening/closing devices. . Furthermore, some users prefer to have the back door 2 locked when it is fully open, and some users may prefer to leave it without the lock function because once it is locked, it is troublesome to release the lock when it is closed. However, there are no known conventional back door opening/closing devices that can be used selectively between locking and no locking functions.

Therefore, the object of the present invention is to enable selection of the operating state of locking or no locking function at maximum extension, to decelerate the extension operation near the end of extension, and to prevent stoppage in the middle of the stroke. To provide a stay damper which is suitable for use in opening and closing a back door of an automobile, an engine hood, etc., which has a simple mechanism, can protect a piston rod, can confirm a locked state from the outside, and has a simple mechanism.

In order to achieve this objective, the configuration of the present invention is as follows:
A piston rod is slidably inserted into the cylinder via a piston, and the piston rod is always urged in the direction of extension by a gas spring inside the cylinder.In the stay damper, a cover is attached to the piston rod so that it can rotate freely at its base end. A protrusion is formed in the axially intermediate position of the cover, and a protrusion is formed radially inward at the axially intermediate position of the cover, and a protrusion is formed at an arbitrary angle in the circumferential direction from this protrusion in the direction from the axially intermediate position toward the open end. In addition to forming an inward protruding strip whose degree of protrusion gradually increases as it goes toward the open end, a locking step is formed by bending the end of the inward protruding strip on the cover open end side. On the other hand, the cylinder side has an outer diameter larger than the inner diameter of the locking step, and slides in contact with the inner protrusion to brake the extension movement of the piston rod. An outwardly protruding flange-like locking portion that selectively engages with the piston rod to lock the piston rod is provided, and the outer periphery of the flange-like locking portion has a large diameter groove that allows the passage of the protrusion and a small diameter groove that prevents the passage of the protrusion. is formed at a position shifted by an arbitrary angle in the circumferential direction.

Embodiments of the present invention will be described below with reference to the drawings.

3 to 12 show a stay damper according to a preferred embodiment of the present invention, in which a piston rod 18 is slidably inserted into a cylinder 16 via a piston, and the piston rod 18 is held within the cylinder 16. It penetrates the cushion 19, the seal 20, and the bearing 21 and protrudes to the outside, and the cylinder 1
Two oil chambers are partitioned within 6 by pistons,
A gas chamber filled with gas is defined on one side of the oil chamber through a free piston, etc., and the two oil chambers communicate with each other through a communication hole formed in the piston, and the end of the cylinder 16 and A bracket 45 is fixed to the outer end of the piston rod 18, and a stay damper 46 is interposed between the vehicle body and the back door of the automobile via this bracket 45.

The outer end of the bearing 21 projects outward from the end surface of the cylinder 16, and the outer circumference of the outer end of the bearing 21 is made larger than the outer diameter of the cylinder 16 to form an annular outwardly projecting flange-like locking portion 27. The flange-like locking portion 27 may be formed not on the bearing 21 but on the cylinder 16 itself.

Two small-diameter grooves 22 are formed along the axial direction at opposing positions on the outer periphery of the outwardly projecting flange-like locking portion 27, and the small-diameter grooves 22 can also be formed at arbitrary angles from the small-diameter grooves 22.
For example, opposing large-diameter grooves 23, 23 and 24, 24 are formed at positions shifted by 45 degrees and 135 degrees, respectively.

Further, on the inner end surface of the flange-like locking portion 27, a sliding surface 25 is provided at a position facing the grooves 22, 23, and 24.
25, 26, 26, 28, and 28 are formed in a tapered shape. Similarly, on the outer end surface of the flange-like locking portion 27, there is a horizontal surface facing the groove 22 and at right angles, and a tapered sliding surface 3 is formed at a position facing the grooves 23 and 24.
5 is formed.

Next, for example, a cylindrical cover body 29 is rotatably held near the end of the piston rod 18 to cover the outer circumference of the externally exposed portion of the piston rod 18 to protect the piston rod 18 from being scratched or dirt attached. are doing.

The cover 29 is molded from an elastic material such as metal or synthetic resin, and the inner diameter D ₂ of the proximal cylindrical portion 30 of the cover body 29 is equal to the flange-like locking portion 2 of the bearing.
The outer diameter D ₁ of No. 7 is larger (D ₂ >D ₁ ). The cover body 29 has inwardly convex portions 31, 31 formed along the axial direction in a portion extending from the cylindrical shape 30 toward the open end, with opposing portions formed into a tapered shape. In the vicinity of the open end of the cover 29, locking step portions 32, 32, which are bent at a right angle or slightly inclined and have an L-shaped cross section, are formed. ) is the outer diameter D ₁ of the outwardly protruding flange-like locking portion 27 on the bearing side.
It is formed smaller (D ₂ >D ₁ >L).

A locking step portion 32 is provided on the outer periphery of the mouth end of the cover body 29.
Small protrusions 36, 36 for positioning corresponding to 32 are formed facing inward, and large protrusions 37, 37 for opposing intermediate stops are made to protrude inward on the cylindrical portion 30. 36, 36 and large protrusion 37,
The position 37 is set at a position shifted by 45 degrees on the axis.

The small protrusions 36, 36 are adapted to selectively engage with any of the grooves 22, 23, 24 on the cylinder side by rotation of the cover body 29. That is, groove 2
2, it faces the mark a, and at this time, the perpendicular outer end surface of the flange-like locking part 27 engages with the locking step part 32, enabling locking at the maximum extension, and At the position where the protrusion 36 engages with the groove 24, it faces the mark b, and at this time, the large protrusion 37 faces the groove 22 on the same line, making it possible to stop in the middle, and further at the position where the protrusion 36 faces the groove 23. At this time, the locking step portion 32 and the large protrusion 37 face the grooves 23 and 24, respectively, and can freely extend and contract or release the engagement without having a locking function.

In the present invention, by selectively aligning one of the marks a, b, and c with the small protrusion 36, locking and release at maximum extension, stopping action at an intermediate position, and locking over the entire stroke range are achieved. It is designed so that it can be selectively expanded and contracted without any function. Therefore, the small protrusion 36 itself also serves as a mark, and its shape is not limited to that shown, and other mark means can also be used. At the position where the protrusion 36 is fitted into the groove 22, the locking during extension can be confirmed from the outside, and at the position where the groove 22 and the protrusion 36 are not fitted, the intermediate stop or the lock can be freely released in the telescopic operating state. .

Therefore, the grooves 22, 23, 24 and the protrusion 3 determine whether the lock is in the intermediate stop, no lock function (or released position), or locked position.
This can be easily confirmed from the outside by inspecting the position 6.

Next, we will discuss the operation.

When the back door is closed and the stay damper 46 is in the most compressed state, the bearing side outward protruding flange-like locking portion 27 is attached to the cylindrical portion 3 of the cover body 29.
0, and the cylindrical portion 30 and the flange-like locking portion 27 are not in contact with each other.

Next, align the protrusion 36 with the mark a, and
32 and the groove 22 are on the same straight line, and the large protrusion 3
7 is on the same straight line as the groove 23 (the third
(Fig. 4), if you open the back door from this state,
The piston rod 18 expands due to the reaction force of the gas spring, and the cylinder 16 moves in the direction of arrow Y. At this time, the outer periphery of the flange-like locking part 27 does not come into contact with the inner surface of the cylindrical part 30 of the cover body 29 due to the relationship D ₂ > D ₁ , and therefore, when the extension starts, the cylinder 16 moves smoothly and quickly in the extension direction. Moving. At this time, even if the large protrusion 37 meets the large diameter groove 23 on the way, the large protrusion 37 passes through the groove 23 without being caught because the curvature of the large diameter groove 23 is larger than the curvature of the large protrusion 37. Next, when the cylinder 16 reaches approximately the middle position, the outer periphery of the flange-like locking portion 27 comes into sliding contact with the inner surface of the inner protruding strip 31 of the cover body 29 due to the relationship D ₁ >L. Since the inner diameter becomes smaller toward the mouth end, when the inward protruding portion 31 and the flange-like locking portion 27 come into sliding contact, as it approaches the end of extension, it is braked and decelerated within the range of length l ₁ . List the effects.

When the cylinder 16 further extends and reaches its maximum extension, the sliding surface 25 of the bearing-side locking portion 27 rides on the end of the inner convex strip 31, and the outer end surface of the flange-like locking portion 27 facing the groove 22 As shown in Figs. 4 and 9, the protrusion 36 fits into the inner end surface of the locking step 32 and the groove 22, and at this time, the back door or engine hood connected to the stay damper 46 is kept fully open. be done.

Therefore, when the back door or the like is pressed in the closing direction by an external load while it is fully open, the left end surface of the flange-like locking portion 27 is at a right angle, so this end surface is hooked on the locking step portion 32. This prevents the cylinder 16 and piston rod 18 from moving in the compression direction (FIG. 4), thereby preventing the back door etc. from falling in the closing direction.

On the other hand, when closing a back door etc. from a fully open state,
In other words, when the stay damper 46 is released from its fully extended lock state and compressed again, the cover body 29 is manually rotated 45 degrees relative to the cylinder 16 while remaining in the locked state shown in FIGS. 3 and 6. , by fitting the protrusion 36 into the groove 23 so that the locking step 32 and the protrusion 36 correspond to the mark c, and from this state, by forcibly applying a compressive force in the axial direction to the cylinder 16 via a backdoor etc. , the cover 29 is made of an elastic material, and the groove 23 of the flange-like locking portion 27 is
Since the outer end surface corresponding to
2 expands outward and climbs over the flange-like locking portion 27, the locking state between the locking portion 27 and the locking step portion 32 is easily released, and furthermore, from this state, the cylinder 16
When pressed in the compression direction, the cylinder 16 and the bearing-side outwardly projecting flange-shaped locking portion 27 engage the cover 2.
Since the large protrusion 37 that slides in the direction of the arrow X inside the main body 9 and is located at an intermediate position can also pass through the large diameter groove 24 without engaging it, the stay damper 46 is moved to the maximum compression position.

Furthermore, if the cover main body 29 is rotated 45 degrees and the protrusion 36 is aligned with the mark c from the beginning in the same manner as above, the locking stepped portion 32 will be moved to the flange-like locking portion 27 at the most extended position. sliding surfaces 26, 3 on both end edges of
5, and therefore it is in a relatively free passing state even at the most extended position, and the extension and contraction operations can be performed smoothly. That is, in this position, the locking step portion 32 is connected to the cylinder side outwardly protruding flange-shaped locking portion 2.
7 faces the sliding surfaces 26 and 35 on both end faces, and the large protrusion 37 faces the large diameter groove 24. Therefore, first, during the expansion and contraction operation at the intermediate position, the large protrusion 37 slides against the large diameter groove 24. At the most extended position, the locking step 32 rides on the sliding surface 26 and can pass, and the locking step 32 engages with the other sliding surface 35 as shown in FIG. However, if a force in the compression direction is applied at this time, the locking step 32 can easily pass on the sliding surface 35 in the compression direction, so it cannot be locked and becomes free at any position.

Next, when the cover body 29 is rotated and the protrusion 36 is aligned with the mark b, the large protrusion 37 will face the small diameter groove 22, and when it is extended from this state, the intermediate At this position, the large protrusion 37 is hooked on the small warp groove 22, and the piston rod 18 cannot be extended any further, in other words, the stay damper 46 is stopped at the intermediate position, thereby leaving the back door etc. half open.

Incidentally, FIG. 11 is a perspective view of the case where the cover main body 29 is press-formed and the body portion is spot welded, but it is substantially the same as that shown in FIG. 3.

In the above-mentioned embodiment of the present invention, the cover-side inward convex strip 31 and the cylinder-side outwardly protruding flange-like locking part 27 come into sliding contact with each other during extension, so that the deceleration function near the maximum extension can be satisfied. No orifice or valve required. In addition, at the fully extended position, the right-angled outer end surfaces of the cover-side locking step 32 and the cylinder-side outwardly protruding flange-like locking portion 27 can be fitted and locked, so that the locking function during extension is satisfied, and this locking It is safe because the status can be checked from the outside.

Also, since it is possible to lock the door at an intermediate position, it is convenient to keep the back door or the like half open on rainy days, for example.

Furthermore, since a cover 29 is attached to the piston rod 18, it is possible to prevent the rod from being scratched and from getting dust or the like over its entire protruding length. Furthermore, the locking function is troublesome, and for those who do not like such a function, it is possible to select an operating state without the locking function in order to perform the expansion and contraction operation smoothly, and the use is diverse.

FIG. 13 shows another embodiment of the present invention, in which a part of the cover body 29 is cut as an inward convex strip on the cover body 29 side, and this cut piece 40
is pushed downward to be used as an inward protruding strip, and a locking step 41 is provided at the end of this cut piece 40.
It is folded and made to stand up. In this case, the inwardly protruding strip portion formed by the cut piece 40 has a deceleration function, and the locking step portion 41 has a locking function at the maximum extension.

In the present invention, a rotatable cover part and a cylinder part are used, an inwardly protruding strip part, a locking step part, and a large protrusion are provided on the cover side, and an outer periphery of an outwardly protruding flange part on the cylinder side is provided. By providing these inward convex stripes, the locking step, the locking part that selectively engages with the large protrusion, the sliding surface that allows passage, and the large diameter groove, the rod extension side deceleration function and extension are improved. Time locking function and cover body 29
It has a rod protection and intermediate stop function, and all of these functions can be confirmed from the outside directly or through marks, so it is safe and reliable.Since each member is external, it is easy to attach and detach. The parts are easy to process and repair, the manufacturing cost is low, the structure is simple, and the operation can be performed in either a telescopic operating state with a locking function or a telescopic operating state without a locking function, depending on your preference. By being able to select an intermediate stop at one point when the door is open other than the extended position, it is possible to put in and take out luggage in a garage with a low ceiling, without damaging the exterior of the door, and to prevent luggage on rainy days. It is convenient for taking things in and out.

[Brief explanation of drawings]

Fig. 1 is a front view of an automobile using a conventional stay damper, Fig. 2 is a partially cutaway longitudinal sectional front view of a conventional stay damper, and Fig. 3 is a partially cutaway front view of a stay damper according to an embodiment of the present invention. Fig. 4 is a longitudinal sectional front view of Fig. 3, Fig. 5 is a longitudinal sectional front view of the stay damper in the intermediate stop state of Fig. 3, Fig. 6 is a right side view of the cover body, and Fig. 7 is a right side view of the bearing. Top view, Figure 8 is the left side view of the bearing,
Fig. 9 is a partially longitudinal front view showing the locked state at maximum extension, Fig. 10 is a partially longitudinal front view showing no lock function or unlocked state at maximum extension, and Fig. 11 is a molded product by press working. FIG. 12 is an exploded perspective view of the stay damper, FIG. 12 is a partially enlarged perspective view of the cover and bearing, and FIG. 13 is a partially cutaway perspective view of the stay damper according to another embodiment. 16...Cylinder, 18...Piston rod,
21...Bearing, 22...Small diameter groove, 23,2
4...Large diameter groove, 27...Outward protruding flange-like locking part, 29...Cover, 31...Inward convex strip, 32
...Locking step portion, 37...Protrusion, 40...Notch piece.

Claims (1)

[Claims] 1. A piston rod is slidably inserted into the cylinder via a piston, and the piston rod is always urged in the direction of extension by a gas spring in the cylinder. The cover is rotatably connected on the proximal end side, and a protrusion is formed in the axially intermediate position of this cover, and a protrusion is formed radially inward at a position offset from this protrusion by an arbitrary angle in the circumferential direction. Forming an inward convex strip whose degree of protrusion gradually increases from the intermediate position toward the open end, and
A locking step is bent and formed at the end of the inner protrusion on the cover open end side, and the inner protrusion has an outer diameter larger than the inner diameter of the locking step on the other cylinder side. An outwardly protruding flange-like locking portion is provided which slides in contact with the piston rod to brake the extension movement of the piston rod, and further selectively engages with the protrusion or the locking step to lock the piston rod, and the flange-like locking portion A stay damper in which a large diameter groove that allows the projection to pass therethrough and a small diameter groove that prevents the passage of the projection are formed at positions shifted by an arbitrary angle in the circumferential direction on the outer periphery of the stay damper. 2. The stay damper according to claim 1, wherein the inward convex strip is tapered. 3. The stay damper according to claim 1, in which the inwardly protruding stripes are formed of cut pieces. 4. The stay damper according to claim 1, wherein the protrusion and the inward convex strip are provided at positions shifted by 45 degrees. 5. The stay damper according to claim 1, wherein the flange-like locking portion is formed at the outer end of the bearing. 6. The stay damper according to claim 1, wherein the inwardly protruding strip is provided to face a part of the cover. 7. The stay damper according to claim 1, wherein the grooves of the flange-like locking portion are provided at positions shifted by 45 degrees.