JPH10218526A - Return testing device for hydraulic shock absorber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a return testing device for hydraulic shock absorber, capable of preventing its cable member from disengaging from its lock means during a return test. SOLUTION: A return testing device for a hydraulic shock absorber involves a lock metal fitting 49 arranged at the other end of a rope 8 as a cable member and having a lock hook adapted to be locked on lock means and detachably grasped by the lock means 6. For a return test, the rope 8 is first positioned at its intermediate portion on a guide body 7, with its one end being by a take-up device 5 as draw means for drawing and the other free end being locked on the lock means 6 by means of the metal fitting 49. In that state, the rope 8 is then drawn tight by the take-up device 5 with the use of an electric drill 22 as power means to press a plunger 3 being tested downward to the lowermost position. That setup reliably lowers the plunger 3 to permit a smooth and safe return test.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic shock absorber return test device used for performing a return test of a hydraulic shock absorber installed at the bottom of an elevator shaft or the like.

[0002]

2. Description of the Related Art Generally, in an elevator, a cylinder which is provided upright at the bottom of a hoistway and contains oil, a plunger which is slidably fitted to the cylinder, and a biasing force for extending the plunger. And a hydraulic shock absorber having a return spring. In such an elevator, when a car that moves up and down the hoistway descends beyond a predetermined lower limit position, the car abuts against the tip of the plunger, and the plunger descends, causing collision with the car. The accompanying shock is softened.

Conventionally, a return test device used for performing such a return test of a hydraulic shock absorber includes two latches provided on the outer periphery of a cylinder of the hydraulic shock absorber, and one end of one of the latches. A belt whose intermediate part is wound around the plunger head, a belt winding means to which the other end of the belt is connected, one end connected to the belt winding means, and the other end of which is connected to the other hook. And a connecting body to which the belt is wound, wherein the belt winding means includes a drum for winding the belt, and an operation lever for operating a rotation operation of the drum,
There is a configuration having a ratchet mechanism that allows rotation of the drum in the winding direction, and a stopper that engages with the ratchet mechanism and regulates the rotation of the drum in the rewinding direction.

[0004] When performing a return test of the hydraulic shock absorber using the conventional return test apparatus thus constructed, first, two latches are attached to the outer periphery of the cylinder of the hydraulic shock absorber by bolts, and one end of the belt is connected to the latch. And the intermediate part of this belt is hung over the plunger head,
Next, the belt wrapping means is connected to the other hook via a connecting body, and the other end of the belt is wrapped around the drum of the belt wrapping means. Thereafter, when the operation lever of the belt winding means is reciprocated several tens of times by hand, and the other end of the belt is wound on the drum, the ratchet mechanism and the stopper intermittently engage to rewind the drum. The rotation operation in the direction is prevented, and the other end of the belt is pulled. In response, the head of the plunger is pressed vertically via the belt, and the plunger gradually descends to reach the lower end position. Next, the engagement state between the ratchet mechanism and the stopper is released, and the drum is rotated in the rewind direction to return the plunger by the biasing force of the return spring. To test.

[0005] An example of this type of a hydraulic shock absorber return test device is described in Japanese Patent Publication No. 2-58579.

[0006]

In the above-described conventional hydraulic shock absorber recovery test apparatus, when the belt is wound around the drum of the belt winding means for lowering the plunger, the operating lever is manually operated by several tens of hands. There is a problem that it is necessary to make a reciprocating motion twice, which takes a considerable amount of time and requires labor. In addition, the stopper of the belt winding means is formed in a small plate shape and is always urged by a spring in a direction to engage with the ratchet mechanism, so that the engagement between the stopper and the ratchet mechanism is released. In such a case, it is difficult for the operator to operate with his / her fingers.
Furthermore, when mounting two latches around the cylinder of the hydraulic shock absorber, it is necessary to fasten with a plurality of bolts,
There was a problem that workability was inferior.

Therefore, in order to solve the above-mentioned problem, a guide body which is mounted on the head of the plunger and guides an intermediate portion of the cord-like body, and one end of the cord-like body which is located on one side of the cylinder outer periphery, A pulling means for pulling, an electric means for driving the pulling means, a locking means located on the other side of the cylinder outer periphery facing the locking means and capable of locking the other end of the cord-like body; There has been developed a hydraulic shock absorber return test apparatus including an attaching means for detachably attaching the pulling means and the locking means to the outer periphery of a cylinder.

[0008] However, in this return test device under development, the other end of the cord is gripped by the locking means. Experiments have shown that it deviates from the means.

The present invention has been made in view of such a situation in the prior art, and an object of the present invention is to provide a hydraulic shock absorber return test device capable of preventing a cord from coming off a locking means during a return test. To provide.

[0010]

SUMMARY OF THE INVENTION In order to achieve this object, the present invention provides a cylinder containing oil, a plunger slidably fitted to the cylinder, and a return for urging the plunger in an extending direction. Used in a hydraulic shock absorber provided with a spring, the plunger has a rope having an intermediate portion wound around the head, and after pushing the plunger with the rope, the pressed state is released, In a hydraulic shock absorber return test device that tests whether the return operation of the plunger is normal, a guide body that is mounted on the head of the plunger and guides an intermediate portion of the cord-like body, A tensioning means for pulling one end of the cord-like body, an electric means for driving the tensioning means, and a tensioning means on the outer periphery of the cylinder facing the locking means, The end Locking means that can be stopped, mounting means for detachably mounting the pulling means and the locking means on the outer periphery of the cylinder, and provided at the other end of the cord-like body and locked by the locking means With a locking bend,
And a locking fitting detachably held by the locking means.

According to the present invention constructed as described above, when performing a return test of the hydraulic shock absorber, first, the tension means is attached to one of the outer circumferences of the cylinder via the attachment means, and the locking means is connected to the cylinder. The guide is mounted on the other side of the outer periphery facing the locking means, and the guide body is mounted on the head of the plunger. Then, an intermediate portion of the cord is positioned on the guide body, one end of the cord is made capable of being pulled by the pulling means, and the other end of the cord is engaged with the engaging member via a lock. Engage with the stop means. That is, the locking fitting is gripped by the locking means with the locking bent portion locked by the locking means. Thereafter, the pulling means is driven by the electric means, one end of the cord is pulled, and the plunger is pressed via the cord and the guide to the lower end position. It is released to test whether or not the return operation of the plunger is normal. In this way, the other end of the cord-like body is interlocked with the locking means by the locking bent portion via the locking metal fitting,
Also, since the locking means is securely held by the locking means by the locking means, it is possible to prevent the cord from coming off the locking means during the return test.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a hydraulic shock absorber return test apparatus according to the present invention will be described below with reference to the drawings.

FIG. 1 is a front view showing an embodiment of a return test device for a hydraulic shock absorber according to the present invention, FIG. 2 is a front view showing a state where a plunger is lowered by the return test device of FIG. 1, and FIG.
5 is a front view showing a state where one end of the cord-like body of the return test apparatus of FIG. 1 is opened, FIG. 4 is a plan view of the return test apparatus of FIG.
FIG. 6 is a cross-sectional view taken along line AA of FIG. 3, and FIG.
7 is a cross-sectional view taken along line CC of FIG. 6, FIG. 8 is a front view showing locking means of the return test apparatus of FIG. 1, and FIG. 9 is a return test apparatus of FIG. 10 is a side view of the pulling means viewed from the mounting surface side, FIG. 10 is a front view showing a main part of the mounting means of the return test apparatus of FIG. 1, FIG. 11 is a side view showing a main part of the mounting means of FIG. 12 is a plan view showing a main part of the mounting means of FIG. 10, FIG. 13 is a front view showing another main part of the mounting means of the return test apparatus of FIG. 1, and FIG. 14 is a main part of the mounting means of FIG. FIG. 15 is a plan view showing a main part of the mounting means of FIG. 10, FIG. 16 is a front view showing a lock of the return test apparatus of FIG. 1, and FIG. 17 is a lock of FIG. Side view of the
FIG. 18 is an explanatory view for explaining a procedure of a bow knot applied to the other end of the cord-like body of the return test apparatus of FIG. 1, and FIG. 19 is a work procedure of a return test of the hydraulic shock absorber by the return test apparatus of FIG. It is a flowchart which shows. FIG. 11 shows an arrow P in FIG.
View from a direction indicated by _1, 12 is a view seen from the direction indicated by the arrow P ₂ in FIG. 10, FIG. 14 is a view as viewed from a direction indicated by an arrow to Q ₁ 13, 15 arrows in FIG. 13 is a view from the direction indicated by Q _2.

For example, a bottom 1a in a pit of an elevator shaft
As shown in FIG. 1, a hydraulic shock absorber 1 erected on a cylinder 2 has a cylinder 2 containing oil, a plunger 3 slidably fitted to the cylinder 2, and a plunger 3 extending in a direction in which the plunger 3 extends. There is provided a return spring (not shown) for biasing, a flange portion 2a formed on the upper portion of the cylinder 2 and made of a square plate, and a step portion 2b formed below the flange portion 2a.

As shown in FIGS. 1 to 4, the return test device 4 of the present embodiment is located at one of the outer circumferences of the cylinder 2 and pulls one end of a cord-like body described later, for example, a winding device. 5, locking means 6 which is located on the other side of the outer periphery of the cylinder 2 and which faces the winding device 5, and which locks the other end of the below-described cord-like body, 7, a guide body 7, an intermediate portion of which is guided, and one end thereof is pulled by the winding device 5 and the other end thereof is locked by the locking means 6, for example, a rope 8, and the cylinder 2.
16 and 17, an attaching means 9 for detachably attaching the winding device 5 and the engaging means 6 to the outer periphery of the apparatus, and an engaging bent portion 49a for engaging the engaging means 6 as shown in FIGS. 6 and a locking metal fitting 49 that is detachably gripped by the locking member 6.

The above-mentioned winding device 5 is shown in FIGS.
As shown in the figure, the main body case 5a and the main body case 5a
, A worm wheel 12 attached to the side surface of the winding drum 10 via a bolt 11, and a worm 1 screwed to the worm wheel 12.
3 and a worm shaft 14 to which the worm 13 is fixed
And a support shaft 15 for rotatably supporting the winding drum 10 and the worm wheel 12 via bearings 16 and 16a, respectively, and a U-shape in which both ends of the support shaft 15 are attached to both ends via bolts 17 , A reinforcing frame 19, 19a provided in the main body case 5a, and support frames 20, 20a provided in the main body case 5a and rotatably supporting the worm shaft 14.

In the winding device 5, when the operating body 18 is gripped and pulled downward in FIG. 6 to move the support shaft 15 by the gap G, the worm wheel 12
From each other, the state in which the two mesh with each other is released. Next, when the operating body 18 is pressed upward to return the support shaft 15 to the initial position as shown in FIG. 6, the worm wheel 12 returns to a state in which it is engaged with the worm 13. As shown in FIG. 7, the movement of the worm shaft 14 in the thrust direction is restricted by the collar 34, the rolling wheel 35, and the thrust 36. And the worm 13 is
The worm 13 and the worm shaft 1 are attached to the worm shaft 14 by an attachment member 13a such as a screw.
4 rotates integrally. Further, as shown in FIG. 7, one end of the worm shaft 14 protrudes from the main body case 5a of the winding device 5, and a connection portion 14a is provided at this one end. An electric means, for example, an electric drill 22 as shown in FIGS. 1 to 3 can be connected to the connection portion 14a.
When the electric drill 22 is started with the electric drill 22 connected to the connection portion 14a of the worm shaft 14, the drum 10 is sequentially passed through the worm shaft 14, the worm 13, and the worm wheel 12.
Is driven.

Further, the rope 8 has a round cross section and is made of, for example, polyarylate fiber.
As shown in FIG. 6, one end 8a of the rope 8 is fixed to the drum 10 of the winding device 5 by a fastening band 21, and is wound with the rotation of the drum 10 in the winding direction. ing.

Further, the above-mentioned locking fitting 49 is provided in FIG.
17, a through hole 49b through which the other end 8b of the rope 8 is inserted is provided. Then, after inserting the other end 8b of the rope 8 into the through hole 49b, the other end 8b is tied to the other end 8b by the steps (a), (b), (c), and (d) of FIG. Attach it to the fastener 49. Note that a heart-shaped auxiliary metal fitting 50 is interposed between the rope 8 and the locking metal 49 so that the rope 8 is not damaged by the locking metal 49.

As shown in FIG. 8, the locking means 6 has a movable portion 23 and a fixed portion 24, and a gripping body for gripping a locking fitting 49 provided on the other end 8b side of the rope 8. 25
And an operating handle 26 for operating the grip 25 and a release lever 26a for releasing the gripping state of the locking fitting 49 by the grip 25.

In such a locking means 6, the locking handle 49 is brought into contact with the fixed portion 24, and the locking handle 49 a is locked to the head 23 a of the movable portion 23 while the operating handle is held. When the gripper 26 is gripped and rotated clockwise in FIG. 8, the gripper 25 is urged in a closing direction by a spring (not shown),
The head 23a of the movable portion 23 comes into strong contact with the locking fitting 49,
Thereby, the locking fitting 49 is gripped by the gripping body 25. Next, when the release lever 26a is rotated in the direction of the operation handle 26, the gripper 25 rotates in a direction away from the fixing portion 24 by the biasing force of the spring. Is released.

Further, as shown in FIG. 4, the guide body 7 has a vibration isolating rubber 27 attached to the upper surface of the head of the plunger 3, and a first vibration isolating rubber 27 provided on the upper surface of the rubber isolating rubber 27 along the rope 8. A support member 28, a second support member 29 provided on the first support member 28 so as to intersect with the first support member 28,
A roller 30 rotatably disposed at both ends of the support member 28 and having a U-shaped groove formed around the outer periphery thereof so that the rope 8 can be engaged with the roller 30;
30a, and the rollers 30, 30a
By rotating while receiving in the U-shaped groove,
The rope 8 can be moved smoothly.

Further, as shown in FIG. 5, the mounting means 9 comprises a chain-type fixed band 31 wound around the outer periphery of the cylinder 2, a chain vise 31a capable of tightening the fixed band 31, a cylinder 2 And the first portion held by the fixing band 31 respectively.
A fixing member 32 and a second fixing member 33 are provided.

As shown in FIGS. 10 to 12, the first fixing member 32 has a base 37 mounted on the outer periphery of the cylinder 2 and a mounting plate 38 on which the winding device 5 is mounted.
And a connecting portion 39 connecting the base portion 37 and the mounting plate 38 to each other, and a magnet 40 provided on the base portion 37 and capable of being attracted to the outer periphery of the cylinder 2. The base 37 and the connecting portion 39 are each formed of a steel molded plate, have a U-shaped cross section, and the mounting plate 38 is also made of steel. At the upper part of the base 37, an inclined surface 37a is formed to engage with the step 2b formed at the upper part of the cylinder 2. At the lower part of the base 37, a locking piece 37b for locking the fixing band 31 is provided. The distance between the locking piece 37 b and the lower end of the connecting portion 39 is set to be larger than the width of the fixed band 31.

Further, the second fixing member 33 is provided as shown in FIG.
As shown in FIG. 15, a base 45 mounted on the outer periphery of the cylinder 2 and a locking means 6 connected to the base 45
And a magnet 47 provided on the base 45 and capable of being attracted to the outer periphery of the cylinder 2.
The base 45 and the mounting portion 46 are each made of a steel formed plate and have a U-shaped cross section. At the upper part of the base 45, an inclined surface 45a is formed to engage with the step 2b formed at the upper part of the cylinder 2. At the lower part of the base 45, a locking piece 45b for locking the fixing band 31 is provided. The distance between the locking piece 45b and the lower end of the mounting portion 46 is set to be larger than the width of the fixed band 31. The attachment portion 46 is provided with a screw hole 48 into which four bolts 24a for fastening the fixing portion 24 shown in FIG.

Further, as shown in FIGS. 7 and 9, a pair of fitting portions 41, 41a with which ends of a mounting plate 38 are fitted are provided on the mounting surface 5b of the main body case 5a of the winding device 5. Is provided. The fitting portion 41 includes a distant piece 42 erected on the main body case 5 a, an elongate plate 43 mounted on the distant piece 42 and extending along the upper end of the mounting plate 38, Stunt piece 42
And a pair of bolts 44 for fastening the elongated plate 43 to the main body case 5a. The upper end of the mounting plate 38 is received between the mounting surface 5b of the main body case 5a and the elongated plate 43. Similarly, the other fitting portion 41a also includes a distant piece 42a erected on the main body case 5a and an elongated plate 43a attached to the distant piece 42a and extending along the lower end of the mounting plate 38. And the distant piece 42a and the elongated plate 43a
a between the mounting surface 5b of the main body case 5a and the elongated plate 43a.
8 to receive the lower end.

In this embodiment, when performing a return test of the hydraulic shock absorber 1, as shown in FIG. 19, as shown in FIG. 19, as shown in FIG. It is fixed to the mounting portion 46, and the second
The base 45 of the fixing member 33 is brought into contact with the outer periphery of the cylinder 2, the inclined portion 45 a is engaged with the step 2 b of the cylinder 2, and is attracted by the magnet 47. Also,
In step S <b> 2, the base 37 of the first fixing member 32 is brought into contact with the outer periphery of the cylinder 2, the inclined portion 37 a is engaged with the step 2 b of the cylinder 2, and the magnet 40 attracts the inclined portion 37 a.

Next, in step S3, the fixing band 31 of the mounting means 9 is wound around the outer periphery of the cylinder 2, and the fixing band 31 is fixed to the locking piece 37b of the first fixing member 32 and the second fixing member 32.
In this state, the chain vice 31a is operated to lock the fixing band 31 on each of the locking pieces 45b of the fixing member 33.
To press against the outer periphery of the cylinder 2. Thereafter, in step S4, the winding is performed by fitting the fitting portions 41, 41a formed on the mounting surface 5b of the winding device 5 to the upper end and the lower end of the mounting plate 38 of the first fixing member 32, respectively. The take-up device 5 is attached to the first fixing member 32, and in this state, the elongated plates 43, 43a of the take-up device 5 and the mounting plate 38 are fixed with pins (not shown) or the like.

Next, in step S5, the guide body 7 is mounted on the head of the plunger 3 via the cushion rubber 27, and the procedure proceeds to step S5.
As 6, the rope 8 wound around the drum 10 of the winding device 5 is pulled out and wrapped around the rollers 30 and 30 a of the guide body 7, and the locking fitting 49 at the other end 8 b of the rope 8 is connected to the locking means 6. It is gripped by the gripper 25. That is, as shown in FIG.
Of the operating handle 26 in this state.
Is operated to grip the locking fitting 49. Then, step S7
The electric drill 22 is connected to the connecting portion 14 of the worm shaft 14.
a, and in this state, the electric drill 22 is activated to drive the winding device 5, and the rope 8 is wound around the drum 10.
To lower the plunger 3 to the lower end position as shown in FIG.

Thereafter, in step S8, the release lever 26a of the locking means 6 is operated to move the operating portion 23 of the grip 25 in a direction away from the fixed portion 24, and the grip 25 holds the metal fitting 49. Release the state, and the other end 8b of the rope 8
To release. Accordingly, the plunger 3 is raised by the urging force of the return spring of the hydraulic shock absorber 1 as shown in FIG. At this time, as step S9, the return time from when the other end 8b of the rope 8 is opened to when the plunger 3 reaches the upper end position is measured, and it is tested whether the return operation of the plunger 3 is normal. That is, if the return time is, for example, 90 seconds or less, the return operation of the plunger 3 is determined to be normal, while if the return time is 90 seconds or longer, the return operation of the plunger 3 is failed. judge.

After the return operation of the plunger 3 is tested as described above, in step S10, the rope 8 is
Then, the guide body 7 is removed from the head of the plunger 3, and the fixed band 31 is removed from the outer periphery of the cylinder 2 by operating the chain vise 31 a of the mounting means 9. At this time,
The fixing members 32 and 33 are attracted to the outer periphery of the cylinder 2 by the magnets 40 and 47, respectively.
1, each of the fixing members 32 and 33 is
Then, the mounting means 9, the winding device 5, the locking means 6, and the guide body 7 are removed from the storage box (not shown) to complete a series of operations of the return test.

In the embodiment configured as described above, the other end 8b of the rope 8 is connected to the locking bent portion 49a via the locking fitting 49.
Is securely locked to the locking means 6 by the locking of the locking means 6 by the locking means 6 and the gripping metal 49 by the locking means 6, so that the rope 8 is locked during the return test. 6 can be prevented.

Further, by driving the winding device 5 with the electric drill 22 to wind the rope 8, the plunger 3 can be lowered quickly and without any labor. The descent time of the plunger 3 at this time can be made within 30 seconds, and can be reduced to about 1/4 compared with the conventional case.

Further, after the plunger 3 is lowered as described above, the operating handle 26 of the locking means 6 is gripped and the release lever 26a is pulled, so that the locking fitting 49 provided on the other end 8b of the rope 8 is provided. Can be released from the locking means and the state in which the plunger 3 is lowered can be released, whereby the opening operation can be performed safely and smoothly.

Further, when attaching the winding device 5 and the locking means 6 to the outer periphery of the cylinder 2, the fixing members 32, 3
Since the magnet 3 is attracted to the outer periphery of the cylinder 2 by the magnets 40 and 47, the winding device 5 and the locking means 6 can be easily fixed by the fixing band 31 in this state. Work is not required, and workability can be improved.

[0036]

Since the present invention is constructed as described above, it is possible to prevent the cord from coming off the locking means during the return test, whereby the plunger can be reliably lowered, and the return test can be carried out smoothly. And it can be done safely.

[Brief description of the drawings]

FIG. 1 is a front view showing an embodiment of a hydraulic shock absorber return test device according to the present invention.

FIG. 2 is a front view showing a state where the plunger is lowered by the return test device of FIG. 1;

FIG. 3 is a front view showing a state where one end of a cord-like body of the return test apparatus of FIG. 1 is opened.

FIG. 4 is a plan view of the return test apparatus of FIG. 1;

FIG. 5 is a transverse sectional view taken along line AA of FIG. 3;

FIG. 6 is a transverse sectional view taken along the line BB of FIG. 5;

FIG. 7 is a transverse sectional view taken along line CC of FIG. 6;

FIG. 8 is a front view showing locking means of the return test apparatus of FIG.

9 is a side view of the pulling means of the return test apparatus of FIG. 1 as viewed from the mounting surface side.

FIG. 10 is a front view showing a main part of a mounting means of the return test apparatus of FIG. 1;

FIG. 11 is a side view showing a main part of the mounting means of FIG. 10;

FIG. 12 is a plan view showing a main part of the mounting means of FIG. 10;

FIG. 13 is a front view showing another main part of the mounting means of the return test apparatus of FIG. 1;

14 is a side view of a main part of the mounting means of FIG. 10 as viewed from a mounting surface.

FIG. 15 is a plan view showing a main part of the mounting means of FIG. 10;

FIG. 16 is a front view showing a locking fitting of the return test device of FIG. 1;

FIG. 17 is a side view of the locking fitting of FIG. 16;

FIG. 18 is an explanatory diagram for explaining a procedure of a bow knot applied to the other end of the cord-like body of the return test device of FIG. 1;

FIG. 19 is a flowchart showing an operation procedure of a return test of the hydraulic shock absorber by the return test device of FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hydraulic shock absorber 2 Cylinder 3 Plunger 5 Winding device (tensile means) 6 Locking means 7 Guide body 8 Rope (cord-like body) 8c Horny knot 9 Mounting means 10 Drum 12 Worm 13 Worm wheel 14a Connection part 22 Electric drill (Electric means) 25 Gripping body 26 Operation handle 26a Release lever 31 Fixing band 31a Chain vice 32, 33 Fixing member 49 Locking fitting 49a Locking bent section 50 Heart-shaped reinforcing fitting

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tokuji Tamaru 1-6-6 Kandanishikicho, Chiyoda-ku, Tokyo, Japan Inside the Hitachi Building System Co., Ltd. (72) Inventor Shoji Yagawa 1-6-6 Kandanishikicho, Chiyoda-ku, Tokyo, Japan In the formula company Hitachi building system

Claims (2)

[Claims] 1. A plunger head for use in a hydraulic shock absorber including a cylinder containing oil, a plunger slidably fitted in the cylinder, and a return spring for urging the plunger in a direction in which the plunger extends. A hydraulic shock absorber for testing whether or not the plunger is returned to its normal state by releasing the pressed state after pressing the plunger with the rope and having the intermediate portion wound around the plunger. In a return test apparatus, a guide body mounted on the head of the plunger and guiding an intermediate portion of the cord-like body, and a tension member that is located at one of the outer circumferences of the cylinder and pulls one end of the cord-like body Means,
Electric means for driving the pulling means, locking means located on the other side of the outer periphery of the cylinder facing the locking means and capable of locking the other end of the cord-like body; Means and an attaching means for detachably attaching the locking means, and a locking bent portion provided at the other end of the cord-like body and locked by the locking means, and detachable by the locking means. A resetting device for a hydraulic shock absorber, comprising: a locking fitting to be gripped on the hydraulic shock absorber. 2. The locking metal fitting has a through hole through which the other end of the cord is inserted, the other end of the cord is inserted through the through hole, and a dangling knot is applied. The return test apparatus for a hydraulic shock absorber according to claim 1, wherein the apparatus is attached to the locking fitting by a lock.